Anterior controllable antidisplacement and fusion surgery for the treatment of multilevel severe ossification of the posterior longitudinal ligament with myelopathy: preliminary clinical results of a novel technique

Anterior controllable antidisplacement and fusion surgery for the treatment of multilevel severe... Purpose Although anterior and posterior decompression surgery are both reported to treat patients with myelopathy caused by ossification of the posterior longitudinal ligament (OPLL). The surgical strategy of the disease is still controversial when the OPLL is multilevel and severe. This present study reports the preliminary clinical results of a novel technique named anterior controllable antidisplacement and fusion (ACAF) for the treatment of multilevel-severe OPLL with myelopathy. Methods A series of 15 patients with cervical myelopathy caused by compression of multilevel severe OPLL were enrolled. All the patients underwent ACAF after thorough surgical designing based on preoperative imaging. The patients were fol- lowed for a mean follow-up duration of 9 months in this study. The main surgical procedures include discectomy of the involved levels, thinning of the anterior part of the involved vertebrae, intervertebral cages, anterior plate and screws instal- lation, bilateral osteotomies of the vertebrae, and antedisplacement of the vertebrae-OPLL complex (VOC). The Japanese Orthopaedic Association (JOA) scales, Visual Analog Scale (VAS) were studied. And the pre- and postoperative radiological parameters, and surgical complications were also investigated. Results Postoperative CT and MRI showed complete decompression of the cord by antidisplacement of the VOC. Restora- tion of neurological defects was confirmed at the last follow-up assessment. Bone fusion was confirmed by CT at 6 months follow-up. No specific complications were identified that were associated with this technique. Conclusions The present study demonstrates that excellent postoperative outcome can be achieved with the use of the ACAF. Though further study is required to confirm the conclusion, this novel technique has the potential to serve as an alternative surgical technique for the treatment of cervical OPLL. Graphical abstract These slides can be retrieved under Electronic Supplementary Material. [Place your key figure or table here] Key points Take Home Messages [List your key wordshere] [List your Take Home Messages here] 1. OPLL; 2. antedisplacement; 3. cervical myelopathy;4. multilevel; 5. ACAF 1.Anterior controllable antedisplacement and fusion (ACAF) surgery can achieve anterior direct decompression without cutting the OPLL. 2. Excellent postoperative outcome can be achieved with the use of ACAF for the treatment of multilevel severe OPLL without specific complications. 3. Compared with the anterior decompression with floating method, the antedisplacement of OPLL in ACAF is immediate feedback to and fully controlled by the surgeon. Electronic supplementary material The online version of this article (http s://doi.org/10.1007 /s005 86-017-5437 -4) contains supplementary material, which is available to authorized users. Extended author information available on the last page of the article Vol.:(0123456789) 1 3 1470 European Spine Journal (2018) 27:1469–1478 Keywords OPLL · Antidisplacement · Cervical myelopathy · Multilevel · ACAF the Changzheng Hospital in Shanghai were prospectively Introduction identified and managed from July 2016 to January 2017. All patients underwent ACAF by the same surgical team. Ossification of the posterior longitudinal ligament (OPLL) The inclusion criteria: (1) OPLL involved three or more is frequently related to cervical myelopathy [1]. The inci- than three vertebrae; (2) OPLL occupation ratio more dence of OPLL among Chinese people is reported to be than 60% [13]; (3) the patient with myelopathy caused by about 3% [2]. The two main surgical strategies used for the OPLL. The exclusion criteria: (1) patients with myelopa- treatment of OPLL are anterior decompression, via ante- thy caused by other diseases such as disc herniation or rior cervical corpectomy and fusion (ACCF) or anterior ossification of the ligamentum flavum; (2) with a history of decompression and fusion with floating method (ADF), injury; (3) with a history previous surgery. This study was and posterior decompression, via laminoplasty or laminec- approved by the institutional review board of our institu- tomy [3, 4]. Although anterior decompression and posterior tion, and all patients signed informed consent. decompression surgery are both reported to treat patients with myelopathy caused by OPLL. The shortcomings of the two techniques are both obvious [5, 6]. Clinical evaluation Anterior decompression surgery directly relieves the cer- vical spinal cord that has been invaded by OPLL, while at Follow-up was conducted in all patients for at least the same time restoring the spinal cord to its original mor- 6  months. A Visual Analog Scale (VAS) was used to phology. Its satisfactory clinical outcome has been proven measure neck pain and arm pain. Japanese Orthopaedic by a large clinical study [7, 8]. However, when dealing with Association (JOA) score were used to assess the degree severe OPLL, the anterior decompression becomes a techni- of disability. An improvement rate (IR) of neurologic cal challenge. The incidence rate of complications includes function was calculated as IR  =  (postoperative JOA cerebrospinal fluid (CSF) leakage, hardware failure, neural score − preoperative JOA score/17 − preoperative JOA injury, or insufficient decompression was reported higher score)/100%. Surgical outcome was defined by the IR as than posterior decompression surgery. And the complica- follows: excellent (IR ≥ 75%), good (75% > IR ≥ 50%), tions increase with the number of involved segments when fair (50% > IR ≥ 25%), and poor (IR < 25%). anterior surgical approaches are used [9, 10]. Posterior decompression surgery is safer than the anterior decompression surgery for it needs no resection of the ven- Radiologic evaluation tral compression component [7]. The effect of the indirect posterior decompression relies much on the cervical lordo- All patients had preoperative and postoperative plain sis alignment to allow the spinal cord floating away from radiographs, computed tomography (CT) scans and three- ventral compression. In cases with bad cervical lordosis or dimensional reconstruction, and magnetic resonance severe OPLL lesion, the neurological improvement is always images (MRI). The parameters described as follows were diminished [11, 12]. investigated: (1) cervical lordosis was measured as the To combine the advantages and avoid shortcomings of angle between a line parallel to the posterior aspect of the anterior and posterior decompression surgery, we have C2 vertebral body and that of the C7 body; (2) the rate designed a novel technique named anterior controllable anti- of narrowing in the spinal canal is calculated by occupa- displacement and fusion (ACAF) surgery that can achieve tion ratio (OR) and space available for the cord (SAC). anterior direct decompression without cutting the OPLL. OR was defined as the thickness of OPLL divided by the This present report is to introduce and demonstrate the pri- anteroposterior diameter of the spinal canal on the axial mary clinical result of the novel technique. CT images; (3) extent and type of OPLL was also investi- gated in the CT sagittal reconstruction images; (4) fusion was determined by CT. CT criteria for fusion includes bridging bone inside or outside the graft and no lucencies Materials and methods extending > 50% of the graft-host interface. Flexion and extension views of lateral plain X-ray were performed to Patient population ensure that no pseudoarthrosis exists. (5) MRIs are used to evaluate the compression to the neural elements. Fifteen multilevel severe OPLL patients with myelopathy admitted to the Second Department of Spine Surgery at 1 3 European Spine Journal (2018) 27:1469–1478 1471 to choose the optimal length of vertebral screw during the Preoperative design hoisting procedure. The preoperative design should be performed according to patient’s symptoms, signs, and preoperative images. Surgical technique The thickness of the OPLL mass in each level is meas- ured to determine how much of the corresponding anterior Anesthesia, positioning, and exposure vertebral body will be resected. The width of the verte- brae–OPLL complex (VOC) to be created is determined After general endotracheal anesthesia, patient was placed in a supine position appropriately padded under the shoulders by measuring the widest part of the OPLL mass (Figs. 1, 2). In most of the cases, the widest part of the OPLL mass and neck. Neurophysiologic monitoring involving soma- tosensory-evoked potentials (SSEPs) and motor-evoked is no wider than the distance between the uncovertebral joints. Therefore, we always chose uncovertebral joints as potentials (MEPs) is utilized to predict the postoperative neurologic deficit. Exposure may be obtained through a the bilateral border of VOC. The computed tomography angiography (CTA) was conducted preoperatively to eval- right- or left-sided Smith–Robinson approach. Once the anterior surface of the cervical spine is exposed, subperi- uate the anatomic variation of vertebral artery. The ante- rioposterior diameter of the involved vertebrae is measured osteal dissection of the longus colli muscle of the involved Fig. 1 A 59-year-old male presented with clumsiness bilateral hands tion demonstrated the bilateral osteotomies conducted at the inner and spastic gait. Preoperative imaging studies demonstrated a seg- border of uncovertebral joints. d Preoperative CT demonstrated the mental type multilevel severe OPLL at C3–C7 levels. The occu- OPLL at C4. e Postoperative CT demonstrated complete decompres- pation ratio was 75%. After an ACAF from C3 to C6, he had a sig- sion occupation ratio decreased to 10%. f Preoperative T2-weighted nificant neurologic recovery, and JOA score increased from 7 to 15 MRI demonstrated severe compression of the spinal cord anteriorly. points with an improvement rate of 80%. a Preoperative CT sagittal g Postoperative T2-weighted MRI showed the decompression. OPLL reconstruction demonstrated a kyphotic alignment in the cervical ossification of the posterior longitudinal ligament, ACAF anterior cer- spine. The dash line square indicates the VOC levels. b Postoperative vical corpectomy and fusion, JOA Japanese Orthopedic Association, CT sagittal reconstruction demonstrated satisfactory antedisplace- CT computed tomography, VOC vertebrae-OPLL complex, MRI mag- ment of VOC from C3 to C6. Cervical lordosis and space available netic resonance images for the cord were restored. c Postoperative CT coronal reconstruc- 1 3 1472 European Spine Journal (2018) 27:1469–1478 Fig. 2 Illustration of the procedures of the Bridge Crane technique. lateral side to the surgeon. Dash lines indicates the VOC. f Antedis- a Axial plane of level of huge OPLL mass (#). b Bilateral border of pacement of the VOC. OPLL ossification of the posterior longitudinal the OPLL mass (dashed lines). c Osteotomy in the contralateral side ligament, VOC vertebrae-OPLL complex to the surgeon. d Installation of the “bridge”. e Osteotomy in the ipsi- segments is performed to the lateral to expose the uncover- levels, the resection of posterior longitudinal ligament is tebral joint. It is helpful to note or mark the midline before required to facilitate the later hoisting of the VOC. In cases elevating the longus to maintain symmetric dissection. that the OPLL excess the caudal or cranial border of the VOC, transection of OPLL is required. After discectomy, Discectomy of the involved levels the OPLL was meticulously separated from the PLL using the microdissector and then transected by 1–2 mm Kerrison Routine discectomies are carried out in the involved levels. rongeur in a piecemeal pattern. On the contrary, no resection The involved levels are defined as the discs with OPLL and of the posterior longitudinal ligament is needed in the levels one disc superior and one disc inferior to the OPLL. Kerri- of VOC (Figs. 2, 3). son rongeurs and high-speed burrs can be used to remove the overhanging osteophytes in the anterior and posterior end- Resection of the anterior vertebral bodies plates to gain a parallel roof and floor to avoid any obstacles of the VOC in the hoisting procedure of the VOC. All bony resection and dissection should be extended laterally to the uncovertebral Resection of the anterior vertebral bodies of the VOC is joints. In the discs, most caudal and cranial of the involved performed by a Leksell rongeurs or a high-speed burr as 1 3 European Spine Journal (2018) 27:1469–1478 1473 Fig. 3 Illustration of the idea of the Bridge Crane technique. a Demonstration of the preop- erative sagittal plane CT of the OPLL. The C2–C7 are the involved levels in this case. And C3–C6 are the levels of VOC. b installation of the “bridge” c antedispacement of the VOC. d The VOC is hoisted by the anterior plate and screw as the way of Bridge Crane hoisting a container. CT computed tomog- raphy, VOC vertebrae-OPLL complex preoperative planning. During the procedure, a prebent ante- contralateral side to the surgeon before the installation of rior cervical plate can be temporarily placed to evaluate if the “bridge” to avoid the interruption of the surgeon’s opera- the space between the plate and remaining vertebral body is tion from the “bridge” (Figs. 1, 2). After the removal of the enough for the hoisting of the OPLL. posterior vertebral wall, we have reached the dorsal side of the lateral posterior longitudinal ligament, with OPLL to the Installation of the intervertebral cages and anterior medial, nerve roots to the ventral, pedicles and intervertebral cervical plate (installation of the “bridge”) foramens to the lateral. We suggest not resecting the lateral posterior longitudinal ligament on the bottom of the troughs Intervertebral carbon fiber cages with a lordosis of 7° filled for three reasons. First, the lateral posterior longitudinal liga- with autogenic bone harvested from the previous procedure ment is quite thin and will not hinder the hoisting of VOC. were then inserted at involved levels for further fusion. The Second, reserving the lateral posterior longitudinal ligament height of each intervertebral cage should be based on the reduced the risk of injury to the nerve roots. Last but not disc space heights to avoid excessive friction generated least, by leaving the lateral posterior longitudinal ligament between the endplate of VOC and adjacent endplates dur- along, the main blood supply to the VOC is reserved to facil- ing the hoisting procedure. The prebent anterior cervical itate further fusion [14]. Intraoperative CT reconstruction titanium alloy plate is then placed. The screws are installed can be done with O-arm to confirm the VOC is fully isolated after proper drilling and taping on the remaining vertebral from the spine. bodies. The screws used in this procedure should not be too short for enough purchase of the vertebral body. No attempt Hoisting (controllable antidisplacement) of the VOC should be made on hoisting the VOC in this procedure. After the placement of the intervertebral cages, anterior cervical This procedure termed the “Bridge Crane technique,” is plate and screws (serve as the bridge for further hoisting of illustrated in Fig. 2. The VOC is hoisted via gradually tight- the VOC), the VOC is temporarily stabilized for the next ening the screws in each vertebra at the same pace with procedure, bilateral osteotomies for the complete isolation screw drives (Fig. 2c). The hoisting, or we called it control- of the VOC from the surrounding bone (Figs. 2, 3). lable antidisplacement, of the VOC can be directly observed as the remaining vertebral bodies are getting closer to the Bilateral osteotomies of the VOC “bridge”. If the antidisplacement is not observed, surgeon should stop tightening the screws and check if the VOC is Bilateral troughs are created among the widest edge of the completely isolated from the surrounding bone by detecting OPLL. We use a 2-mm high-speed cutting burr or piezos- with a nerve hook or taking an intraoperative CT image. urgery to thin the corticocancellous bone first and 1–2 mm The antidisplacement of the VOC should not be too much Kerrison rongeurs to remove the posterior vertebral wall on to prevent tear of the dura mater. Excessive blood loss is the bottom of the troughs. Osteotomy can be done in the usually encountered after the antidisplacement of the VOC, 1 3 1474 European Spine Journal (2018) 27:1469–1478 which can be easily controlled by the usage of hemostasis Table 1 Clinical pre and postoperative data of the patients materials. Before the closure of the wound, autogenous or Item Value allograft bone pieces were graft into the bilateral troughs to Age 62.6 ± 6.2 (52–78) obtain further fusion of the VOC with the surrounding bone. Sex Male 9, female 6 The bilateral longus colli were reconstructed to the anterior Symptom duration, months 36.5 ± 12.3 (2–240) plate by 3-0 silk sutures to cover the graft bones. Follow-up period, months 9.2 ± 1.6 (6–12) Levels with severe OPLL number of Postoperative immobilization patients  C3–C5 3 A halo vest is routinely used postoperatively for external  C3–C6 6 bracing for 3 months. The halo vest maintains the alignment  C4–C6 4 of the cervical spine to prevent failure of the internal fixation  C4–7 2 and enables early mobility of the patients. Operative time, min 173.2 ± 21.5 (120–230) Blood loss, ml 325.8 ± 43.5 (250–800) Statistical analysis JOA score  Before surgery 9.1 ± 2.5 (5–14) Statistical analysis was performed using SPSS [15]. Preop-  6 months after surgery 14.5 ± 1.2 (9–16)* erative and follow-up data such as JOA score, VAS score,  IR 6 months after surgery, % 65.2 ± 9.8 (44.4–88.9) OR, and SAC were compared using paired t test. The level VAS of significance was set at p < 0.05.  Before surgery 5.2 ± 1.6 (2–7)  6 months after surgery 2.4 ± 1.6 (0–5)* Complication, number of patients Results  C5 nerve root palsy 1  Postoperative hematoma 0 Clinicopathologic characteristics  CSF leakage 1  Implant complications 0 The study group included nine male patients and six female patients with a mean age of 62 years (range 52–78 years). Values are expressed as the mean ± standard deviation (range) The mean duration of follow-up was 9  months (range JOA Japanese Orthopaedic Association, IR improvement rate, VAS Visual Analog Scale, CSF cerebrospinal fluid 6–12 months). The spinal level of severe OPLL involve- *p < 0.05, compared with the data before surgery ment was C3–C5 for three patients, C3–C6 for six, C4–C6 for four, and C4–C7 for two. The mean time of symptom duration was 36 months (range 2–214 months). The mean operative time was 173  min (range Table 2 Radiological results of the patients 120–230 min), with the mean blood loss of 326 ml (range Item Value 250–800 ml). The mean JOA score increased from 9.1 ± 1.4 OR, % (range 5–14) at preoperation to 14.5 ± 1.2 (range 9–16) at  Before surgery 67.3 ± 5.1 (60 to 90) the 6-month follow-up (p < 0.05). The average improvement  After surgery 16.4 ± 6.5 (0 to 56)* rate (IR) was 65.2 ± 9.8%. Five (33.3%) patients were graded SAC, mm as excellent, seven (46.7%) as good, and three (20%) as fair.  Before surgery 4.5 ± 2.1 (1 to 7.5) The average VAS was 5.2 ± 1.6 (range 2–7) preoperatively,  After surgery 11.6 ± 2.7 (6 to 16)* 2.4 ± 1.6 (range 0–5) at the 6-month follow-up (p < 0.05). Cervical lordosis, ° All the patients felt immediate release of numbness in upper  Before surgery 3.7 ± 4.2 (− 7.5 to − 14) limbs. The clinical data is summarized in Table 1. After surgery 18 ± 4.7 (15 to 28)* Classification of OPLL (cases) Radiological results  Continuous type 5  Segmental type 3 The radiological outcomes are shown in Table 2. The OR  Mixed type 7 decreased from 67.3 ± 5.1% preoperatively to 16.4 ± 6.5% postoperatively, which was statistically significant Values are expressed as the mean ± standard deviation (range) (p < 0.05). SAC increased from 4.5 ± 2.1 mm preopera- OR occupation ratio, SAC space available for the cord, OPLL ossifica- tively to 11.6 ± 2.7 mm postoperatively, which was statisti- tion of the posterior longitudinal ligament cally significant (p  < 0.05). Postoperative cervical lordosis *p < 0.05, compared with the data before surgery 1 3 European Spine Journal (2018) 27:1469–1478 1475 was 18° ± 4.7° compared with preoperative 3.7° ± 4.2°. A the continuous OPLL in the cranial margin. In that case, fusion rate of 100% was achieved at 6-month follow-up. No lumbar drainage is performed at the second postopera- pseudoarthrosis exists were ensured by flexion and extension tive day and the CSF leak is then controlled and recovered views of lateral plain X-ray 6 months after the surgery. The 1 week after drainage. There was no occurrence of postop- imaging of a typical case is shown in Figs. 1 and 4. erative hematoma. No instrumented failure was observed during follow-up. No specific complications were identified Surgical complication that were associated with this technique. Transient minor neurological deterioration, manifesting with the weakness of right arm occurred in one case (6.7%) after Discussion operation due to the irritation of the nerve root when deal- ing with the massive ossification mass on the very lateral of Although anterior and posterior decompression surgery are C4/5 segment. The weakness in right arm improved signifi- both reported to treat patients with myelopathy caused by cantly 2 weeks following the surgery. The muscle strength of OPLL, controversy still exists over the surgical options. the right arm was improved to 4+ at the 6 months follow-up. The posterior decompression surgery can safely achieve the The CSF leak occurred in one case (6.7%) during transecting decompression of the spinal cord that results from extensive Fig. 4 A 57-year-old female presented with walking disturbance and of the VOC at C3 (b), C5 (c), and C6 (d). e Preoperative sagittal MRI dysfunction of sensation of lower limbs without other complains. (left) shows severe compression of the spinal cord from C3 to C6, and After ACAF from C3 to C6, She had neurologic improvement and postoperative sagittal MR image (right) shows sufficient decompres- JOA score increased from 13 to 16 points with an improvement rate sion of the spinal cord. f Preoperative axial MRI (up) and postoper- of 75%. a Preoperative sagittal CT image (left) shows a massive ative axial MRI (down) shows decompression of the spinal cord. g mixed type OPLL at C2–5 and C6, and postoperative sagittal CT Preoperative (left) and postoperative (right) lateral tomograph. ACAF image (right) shows the ossification was transected behind the C2, anterior cervical corpectomy and fusion, JOA Japanese Orthopedic and the C3–7 VOC was hoisted and fused to an antedisplaced loca- Association, CT computed tomography, OPLL ossification of the tion. Preoperative axial CT image (up) and postoperative axial CT posterior longitudinal ligament, VOC vertebrae-OPLL complex, MRI image (down) shows the massive OPLL mass and antedisplacement magnetic resonance images 1 3 1476 European Spine Journal (2018) 27:1469–1478 OPLL. However, there are limitations in posterior decom- enough decompression to the bilateral nerve roots. The pression surgery, it does not always produce the expected antidisplacement of the VOC further lead to direct and space for cases with a highly narrowed spinal canal or a bad thorough decompression of the spinal cord. The outcome lordosis [16, 17]. Furthermore, the posterior decompression of the ACAF relies on the complete isolation and anti- surgery is accused of higher incidence of C5 palsy, postop- displacement of the VOC, which require thorough pre- erative kyphotic change, and postoperative progression of operative designing, proper selection and installation of the ossified OPLL lesion in many studies [18– 20]. Ante- internal fixation devises, and intraoperative evaluation and rior corpectomy and resection of OPLL can achieve direct trimming of the VOC. Goel et al. reported that stand-alone decompression and gain satisfactory results, especially in fixation resulted in dramatic and sustained neurological cases with highly narrowed spinal canal and short segmental recovery of OPLL. The authors proposed that instabil- OPLL [21]. However, in this high technically demanding ity plays a role in the pathogenesis and development of surgery, the risks of excessive hemorrhage, iatrogenic dam- symptoms related to myelopathy of OPLL. As in ACAF, age to neural tissue, and CSF leakage are reported as fre- the satisfactory clinical recovery may also come from the quently occurring complications [22, 23]. In 1999, Yamaura stabilization and fusion of the spinal segments [27]. et al. reported the anterior decompression surgery with float- CSF leakage is one of the most frequently met compli- ing method for cervical OPLL [24]. The method minimizes cations of the anterior decompression surgery for OPLL surgical invasion and the risk of hemorrhage, spinal cord [28]. In the ACCF surgery, the direct decompression is damage, and leakage of CSF in traditional anterior decom- accomplished by resecting the OPLL in a piecemeal or pression surgery. However, the anteriorly migration of the enbloc pattern. During the resection of OPLL, the adhe- OPLL in floating method is not controlled by surgeon and sion or ossified dura is vulnerable and dural tear is always much owing to the pressure of the CSF, which requires as encountered. Especially when there is a big area of ossified long as 8 weeks for the ossification to complete the migra- dura, the direct resection will lead to a big absence of dura tion [25]. Thus, the impingement between OPLL and the and refractory postoperative CSF leak. The advantage of surrounding bone cannot be foreseen during the procedure ACAF is that it does not need to deal with the adhesion of and often results in incomplete floating of the OPLL [26]. the dura and OPLL or ossified dura. Isolation of the VOC Intraoperative CT scan was used to ensure that the VOC is conducted on the lateral side of the OPLL. In cases that was isolated prior to the hoist. Intraoperative CT scan was the OPLL excess the lateral or caudocranial border of the also used in the floating method to avoid insufficient decom- VOC, separation of the dura and OPLL is required. But pression [26]. However, the intraoperative CT scan is not the in this circumstance, the separation of dura and OPLL only way to know if the VOC is fully isolated, surgeon could is safer because it is near the border of OPLL where the also use a nerve hook to detect the border of the VOC. The adhesion and compression are both mild. There were 6.7% space for hoist can also be measured using a depth detector patients with CSF leakage in this study, which was lower when bridge was set. So the intraoperative CT scan is not a than that in anterior decompression and higher than the must-have in any procedure in the ACAF technique. The use posterior decompression [29, 30]. of the O-arm was useful in initial cases but was omitted from Many studies have reported that the blood loss is larger subsequent cases in a bid to reduce radiation for the patient. in anterior decompression surgery than that in posterior The idea of ACAF is to isolate and “actively transport” decompression surgery. The massive compression in the spi- the OPLL ventrally to restore the space of the spinal canal nal canal obstructs the vein drainage and lead to excessive and thus achieve direct decompression of the neural ele- blood loss, which is one of the reasons for unclear surgical ments with their location unchanged. The remaining verte- view and inadequate decompression [31]. bral body and OPLL mass are then served as an autogenous In our practice, the average blood loss is 328 ml in aver- bone for the reconstruction of the anterior column. Different age and no postoperative hematoma occurred. In ACAF, the from the floating method, in ACAF the antidisplacement of VOC provides as an ideal anchor site for hemostatic materi- the OPLL is achieved under the gradual hoisting force of the als such as bone wax and gel foam. Another important fact anterior plate and screws with an immediate feedback. The is that the present of VOC occupies the potential space for Bridge Crane device is vital in this technique, for it stabilizes the formation postoperative hematoma. the VOC in the procedure of osteotomy and gives the sur- The current study has several limitations. Neurologic geon full control in the procedure of VOC antidisplacement. recovery, occurrence of complications, blood loss, and As shown in the results, the patients who underwent operative time of ACAF could not be directly compared ACAF have all gained satisfactory outcome. The anatomic with those associated with other anterior decompression sur- basic for the clinical effect of ACAF lays in the direc- gery or posterior decompression surgery. Prospective, ran- tor decompression for spinal cord and nerve roots. The domized, controlled studies may be required to adequately procedure of bilateral osteotomies of the vertebrae gives investigate these issues. And long-term follow-up is needed 1 3 European Spine Journal (2018) 27:1469–1478 1477 8. Chen Y, Yang L, Liu Y et al (2014) Surgical results and prognostic to evaluate the long-term outcome and progression of the factors of anterior cervical corpectomy and fusion for ossification ossification. of the posterior longitudinal ligament. PLoS One 9(7):e102008 Our current study has shown that multilevel severe OPLL 9. Shinomiya K, Matsuoka T, Kurosa Y et al (2006) Anterior cervi- with myelopathy can obtain a safe and sufficient decompres- cal decompression for cervical myelopathy caused by ossification of the posterior longitudinal ligament (OPLL). Springer, Tokyo, sion using the novel ACAF technique. The antidisplacement pp 209–218 procedure is controlled using a “bridge crane” device, which 10. Pitzen T, Chrobok JJ, Ruffing S et al (2009) Implant complica- eliminates the need for direct resection of the OPLL, there- tions, fusion, loss of lordosis, and outcome after anterior cervical fore, reducing the risk of injury to the dura and spinal cord. plating with dynamic or rigid plates: 2-year results of a multi- centric, randomized, controlled study. Spine 34(7):641–646 No specific complications were identified that were associ- 11. Hirabayashi K, Watanabe K, Wakano K et al (2001) Expansive ated with this technique. As the procedure described in this open-door laminoplasty for cervical spinal stenotic myelopathy. technique is not technically demanding, it should be consid- Spine 8(7):693 ered when dealing with cases of multilevel severe OPLL. 12. 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Matsuoka T, Yamaura I, Kurosa Y et al (2011) Long-term results severe ossification of posterior longitudinal ligament in the cervi- of the anterior floating method for cervical myelopathy caused cal spine[J]. J Spinal Disord Tech 24(1):24 by ossification of the posterior longitudinal ligament. Spine 7. Tomita K, Nomura S, Umeda S et al (1988) Cervical laminoplasty 26(3):241–248 to enlarge the spinal canal in multilevel ossification of the poste- 26. Yoshii T, Hirai T, Yamada T et al (2017) Intraoperative evalu- rior longitudinal ligament with myelopathy. Arch Orthop Trauma ation using mobile computed tomography in anterior cervical Surg 107(3):148–153 decompression with floating method for massive ossification of the posterior longitudinal ligament. J Orthop Surg Res 12(1):12 1 3 1478 European Spine Journal (2018) 27:1469–1478 27. Goel A, Nadkarni T, Shah A et al (2015) Is only stabilization decompression and arthrodesis in 61 North American patients. J the ideal treatment for ossified posterior longitudinal ligament? Bone Jt Surg 87(3):610 (American Volume) Report of early results with a preliminary experience in 14 30. Hannallah D, Lee J, Khan M et al (2008) Cerebrospinal fluid patients. World Neurosurg 84(3):813–819 leaks following cervical spine surgery. J Bone Jt Surg Am 28. Cho JY, Chan CK, Lee SH et al (2012) Management of cerebro- 90(5):1101–1105 spinal fluid leakage after anterior decompression for ossification 31. Lin D, Ding Z, Lian K et al (2012) Cervical ossification of the pos- of posterior longitudinal ligament in the thoracic spine: the utiliza- terior longitudinal ligament: anterior versus posterior approach. tion of a volume-controlled pseudomeningocele. J Spinal Disord Indian J Orthop 46(1):92 Tech 25(4):E93 29. Belanger TA, Roh JS, Hanks SE et  al (2005) Ossification of the posterior longitudinal ligament Results of anterior cervical Affiliations 1 1 1 1 1 1 1 Jingchuan Sun  · Jiangang Shi  · Ximing Xu  · Yong Yang  · Yuan Wang  · Qingjie Kong  · Haisong Yang  · 1 1 2 1 1 1 Yongfei Guo  · Dan Han  · Jingjing Jiang  · Guodong Shi  · Wen Yuan  · Lianshun Jia * Jiangang Shi Department of Anaesthesiology, Changzheng Hospital, shijiangang616@163.com Shanghai, China Department of Spine Surgery, Changzheng Hospital, 601 Room, 415# Fengyang Road, Huangpu District, Shanghai, China 1 3 http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png European Spine Journal Springer Journals

Anterior controllable antidisplacement and fusion surgery for the treatment of multilevel severe ossification of the posterior longitudinal ligament with myelopathy: preliminary clinical results of a novel technique

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Copyright © 2017 by The Author(s)
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Medicine & Public Health; Surgical Orthopedics; Neurosurgery
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10.1007/s00586-017-5437-4
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Abstract

Purpose Although anterior and posterior decompression surgery are both reported to treat patients with myelopathy caused by ossification of the posterior longitudinal ligament (OPLL). The surgical strategy of the disease is still controversial when the OPLL is multilevel and severe. This present study reports the preliminary clinical results of a novel technique named anterior controllable antidisplacement and fusion (ACAF) for the treatment of multilevel-severe OPLL with myelopathy. Methods A series of 15 patients with cervical myelopathy caused by compression of multilevel severe OPLL were enrolled. All the patients underwent ACAF after thorough surgical designing based on preoperative imaging. The patients were fol- lowed for a mean follow-up duration of 9 months in this study. The main surgical procedures include discectomy of the involved levels, thinning of the anterior part of the involved vertebrae, intervertebral cages, anterior plate and screws instal- lation, bilateral osteotomies of the vertebrae, and antedisplacement of the vertebrae-OPLL complex (VOC). The Japanese Orthopaedic Association (JOA) scales, Visual Analog Scale (VAS) were studied. And the pre- and postoperative radiological parameters, and surgical complications were also investigated. Results Postoperative CT and MRI showed complete decompression of the cord by antidisplacement of the VOC. Restora- tion of neurological defects was confirmed at the last follow-up assessment. Bone fusion was confirmed by CT at 6 months follow-up. No specific complications were identified that were associated with this technique. Conclusions The present study demonstrates that excellent postoperative outcome can be achieved with the use of the ACAF. Though further study is required to confirm the conclusion, this novel technique has the potential to serve as an alternative surgical technique for the treatment of cervical OPLL. Graphical abstract These slides can be retrieved under Electronic Supplementary Material. [Place your key figure or table here] Key points Take Home Messages [List your key wordshere] [List your Take Home Messages here] 1. OPLL; 2. antedisplacement; 3. cervical myelopathy;4. multilevel; 5. ACAF 1.Anterior controllable antedisplacement and fusion (ACAF) surgery can achieve anterior direct decompression without cutting the OPLL. 2. Excellent postoperative outcome can be achieved with the use of ACAF for the treatment of multilevel severe OPLL without specific complications. 3. Compared with the anterior decompression with floating method, the antedisplacement of OPLL in ACAF is immediate feedback to and fully controlled by the surgeon. Electronic supplementary material The online version of this article (http s://doi.org/10.1007 /s005 86-017-5437 -4) contains supplementary material, which is available to authorized users. Extended author information available on the last page of the article Vol.:(0123456789) 1 3 1470 European Spine Journal (2018) 27:1469–1478 Keywords OPLL · Antidisplacement · Cervical myelopathy · Multilevel · ACAF the Changzheng Hospital in Shanghai were prospectively Introduction identified and managed from July 2016 to January 2017. All patients underwent ACAF by the same surgical team. Ossification of the posterior longitudinal ligament (OPLL) The inclusion criteria: (1) OPLL involved three or more is frequently related to cervical myelopathy [1]. The inci- than three vertebrae; (2) OPLL occupation ratio more dence of OPLL among Chinese people is reported to be than 60% [13]; (3) the patient with myelopathy caused by about 3% [2]. The two main surgical strategies used for the OPLL. The exclusion criteria: (1) patients with myelopa- treatment of OPLL are anterior decompression, via ante- thy caused by other diseases such as disc herniation or rior cervical corpectomy and fusion (ACCF) or anterior ossification of the ligamentum flavum; (2) with a history of decompression and fusion with floating method (ADF), injury; (3) with a history previous surgery. This study was and posterior decompression, via laminoplasty or laminec- approved by the institutional review board of our institu- tomy [3, 4]. Although anterior decompression and posterior tion, and all patients signed informed consent. decompression surgery are both reported to treat patients with myelopathy caused by OPLL. The shortcomings of the two techniques are both obvious [5, 6]. Clinical evaluation Anterior decompression surgery directly relieves the cer- vical spinal cord that has been invaded by OPLL, while at Follow-up was conducted in all patients for at least the same time restoring the spinal cord to its original mor- 6  months. A Visual Analog Scale (VAS) was used to phology. Its satisfactory clinical outcome has been proven measure neck pain and arm pain. Japanese Orthopaedic by a large clinical study [7, 8]. However, when dealing with Association (JOA) score were used to assess the degree severe OPLL, the anterior decompression becomes a techni- of disability. An improvement rate (IR) of neurologic cal challenge. The incidence rate of complications includes function was calculated as IR  =  (postoperative JOA cerebrospinal fluid (CSF) leakage, hardware failure, neural score − preoperative JOA score/17 − preoperative JOA injury, or insufficient decompression was reported higher score)/100%. Surgical outcome was defined by the IR as than posterior decompression surgery. And the complica- follows: excellent (IR ≥ 75%), good (75% > IR ≥ 50%), tions increase with the number of involved segments when fair (50% > IR ≥ 25%), and poor (IR < 25%). anterior surgical approaches are used [9, 10]. Posterior decompression surgery is safer than the anterior decompression surgery for it needs no resection of the ven- Radiologic evaluation tral compression component [7]. The effect of the indirect posterior decompression relies much on the cervical lordo- All patients had preoperative and postoperative plain sis alignment to allow the spinal cord floating away from radiographs, computed tomography (CT) scans and three- ventral compression. In cases with bad cervical lordosis or dimensional reconstruction, and magnetic resonance severe OPLL lesion, the neurological improvement is always images (MRI). The parameters described as follows were diminished [11, 12]. investigated: (1) cervical lordosis was measured as the To combine the advantages and avoid shortcomings of angle between a line parallel to the posterior aspect of the anterior and posterior decompression surgery, we have C2 vertebral body and that of the C7 body; (2) the rate designed a novel technique named anterior controllable anti- of narrowing in the spinal canal is calculated by occupa- displacement and fusion (ACAF) surgery that can achieve tion ratio (OR) and space available for the cord (SAC). anterior direct decompression without cutting the OPLL. OR was defined as the thickness of OPLL divided by the This present report is to introduce and demonstrate the pri- anteroposterior diameter of the spinal canal on the axial mary clinical result of the novel technique. CT images; (3) extent and type of OPLL was also investi- gated in the CT sagittal reconstruction images; (4) fusion was determined by CT. CT criteria for fusion includes bridging bone inside or outside the graft and no lucencies Materials and methods extending > 50% of the graft-host interface. Flexion and extension views of lateral plain X-ray were performed to Patient population ensure that no pseudoarthrosis exists. (5) MRIs are used to evaluate the compression to the neural elements. Fifteen multilevel severe OPLL patients with myelopathy admitted to the Second Department of Spine Surgery at 1 3 European Spine Journal (2018) 27:1469–1478 1471 to choose the optimal length of vertebral screw during the Preoperative design hoisting procedure. The preoperative design should be performed according to patient’s symptoms, signs, and preoperative images. Surgical technique The thickness of the OPLL mass in each level is meas- ured to determine how much of the corresponding anterior Anesthesia, positioning, and exposure vertebral body will be resected. The width of the verte- brae–OPLL complex (VOC) to be created is determined After general endotracheal anesthesia, patient was placed in a supine position appropriately padded under the shoulders by measuring the widest part of the OPLL mass (Figs. 1, 2). In most of the cases, the widest part of the OPLL mass and neck. Neurophysiologic monitoring involving soma- tosensory-evoked potentials (SSEPs) and motor-evoked is no wider than the distance between the uncovertebral joints. Therefore, we always chose uncovertebral joints as potentials (MEPs) is utilized to predict the postoperative neurologic deficit. Exposure may be obtained through a the bilateral border of VOC. The computed tomography angiography (CTA) was conducted preoperatively to eval- right- or left-sided Smith–Robinson approach. Once the anterior surface of the cervical spine is exposed, subperi- uate the anatomic variation of vertebral artery. The ante- rioposterior diameter of the involved vertebrae is measured osteal dissection of the longus colli muscle of the involved Fig. 1 A 59-year-old male presented with clumsiness bilateral hands tion demonstrated the bilateral osteotomies conducted at the inner and spastic gait. Preoperative imaging studies demonstrated a seg- border of uncovertebral joints. d Preoperative CT demonstrated the mental type multilevel severe OPLL at C3–C7 levels. The occu- OPLL at C4. e Postoperative CT demonstrated complete decompres- pation ratio was 75%. After an ACAF from C3 to C6, he had a sig- sion occupation ratio decreased to 10%. f Preoperative T2-weighted nificant neurologic recovery, and JOA score increased from 7 to 15 MRI demonstrated severe compression of the spinal cord anteriorly. points with an improvement rate of 80%. a Preoperative CT sagittal g Postoperative T2-weighted MRI showed the decompression. OPLL reconstruction demonstrated a kyphotic alignment in the cervical ossification of the posterior longitudinal ligament, ACAF anterior cer- spine. The dash line square indicates the VOC levels. b Postoperative vical corpectomy and fusion, JOA Japanese Orthopedic Association, CT sagittal reconstruction demonstrated satisfactory antedisplace- CT computed tomography, VOC vertebrae-OPLL complex, MRI mag- ment of VOC from C3 to C6. Cervical lordosis and space available netic resonance images for the cord were restored. c Postoperative CT coronal reconstruc- 1 3 1472 European Spine Journal (2018) 27:1469–1478 Fig. 2 Illustration of the procedures of the Bridge Crane technique. lateral side to the surgeon. Dash lines indicates the VOC. f Antedis- a Axial plane of level of huge OPLL mass (#). b Bilateral border of pacement of the VOC. OPLL ossification of the posterior longitudinal the OPLL mass (dashed lines). c Osteotomy in the contralateral side ligament, VOC vertebrae-OPLL complex to the surgeon. d Installation of the “bridge”. e Osteotomy in the ipsi- segments is performed to the lateral to expose the uncover- levels, the resection of posterior longitudinal ligament is tebral joint. It is helpful to note or mark the midline before required to facilitate the later hoisting of the VOC. In cases elevating the longus to maintain symmetric dissection. that the OPLL excess the caudal or cranial border of the VOC, transection of OPLL is required. After discectomy, Discectomy of the involved levels the OPLL was meticulously separated from the PLL using the microdissector and then transected by 1–2 mm Kerrison Routine discectomies are carried out in the involved levels. rongeur in a piecemeal pattern. On the contrary, no resection The involved levels are defined as the discs with OPLL and of the posterior longitudinal ligament is needed in the levels one disc superior and one disc inferior to the OPLL. Kerri- of VOC (Figs. 2, 3). son rongeurs and high-speed burrs can be used to remove the overhanging osteophytes in the anterior and posterior end- Resection of the anterior vertebral bodies plates to gain a parallel roof and floor to avoid any obstacles of the VOC in the hoisting procedure of the VOC. All bony resection and dissection should be extended laterally to the uncovertebral Resection of the anterior vertebral bodies of the VOC is joints. In the discs, most caudal and cranial of the involved performed by a Leksell rongeurs or a high-speed burr as 1 3 European Spine Journal (2018) 27:1469–1478 1473 Fig. 3 Illustration of the idea of the Bridge Crane technique. a Demonstration of the preop- erative sagittal plane CT of the OPLL. The C2–C7 are the involved levels in this case. And C3–C6 are the levels of VOC. b installation of the “bridge” c antedispacement of the VOC. d The VOC is hoisted by the anterior plate and screw as the way of Bridge Crane hoisting a container. CT computed tomog- raphy, VOC vertebrae-OPLL complex preoperative planning. During the procedure, a prebent ante- contralateral side to the surgeon before the installation of rior cervical plate can be temporarily placed to evaluate if the “bridge” to avoid the interruption of the surgeon’s opera- the space between the plate and remaining vertebral body is tion from the “bridge” (Figs. 1, 2). After the removal of the enough for the hoisting of the OPLL. posterior vertebral wall, we have reached the dorsal side of the lateral posterior longitudinal ligament, with OPLL to the Installation of the intervertebral cages and anterior medial, nerve roots to the ventral, pedicles and intervertebral cervical plate (installation of the “bridge”) foramens to the lateral. We suggest not resecting the lateral posterior longitudinal ligament on the bottom of the troughs Intervertebral carbon fiber cages with a lordosis of 7° filled for three reasons. First, the lateral posterior longitudinal liga- with autogenic bone harvested from the previous procedure ment is quite thin and will not hinder the hoisting of VOC. were then inserted at involved levels for further fusion. The Second, reserving the lateral posterior longitudinal ligament height of each intervertebral cage should be based on the reduced the risk of injury to the nerve roots. Last but not disc space heights to avoid excessive friction generated least, by leaving the lateral posterior longitudinal ligament between the endplate of VOC and adjacent endplates dur- along, the main blood supply to the VOC is reserved to facil- ing the hoisting procedure. The prebent anterior cervical itate further fusion [14]. Intraoperative CT reconstruction titanium alloy plate is then placed. The screws are installed can be done with O-arm to confirm the VOC is fully isolated after proper drilling and taping on the remaining vertebral from the spine. bodies. The screws used in this procedure should not be too short for enough purchase of the vertebral body. No attempt Hoisting (controllable antidisplacement) of the VOC should be made on hoisting the VOC in this procedure. After the placement of the intervertebral cages, anterior cervical This procedure termed the “Bridge Crane technique,” is plate and screws (serve as the bridge for further hoisting of illustrated in Fig. 2. The VOC is hoisted via gradually tight- the VOC), the VOC is temporarily stabilized for the next ening the screws in each vertebra at the same pace with procedure, bilateral osteotomies for the complete isolation screw drives (Fig. 2c). The hoisting, or we called it control- of the VOC from the surrounding bone (Figs. 2, 3). lable antidisplacement, of the VOC can be directly observed as the remaining vertebral bodies are getting closer to the Bilateral osteotomies of the VOC “bridge”. If the antidisplacement is not observed, surgeon should stop tightening the screws and check if the VOC is Bilateral troughs are created among the widest edge of the completely isolated from the surrounding bone by detecting OPLL. We use a 2-mm high-speed cutting burr or piezos- with a nerve hook or taking an intraoperative CT image. urgery to thin the corticocancellous bone first and 1–2 mm The antidisplacement of the VOC should not be too much Kerrison rongeurs to remove the posterior vertebral wall on to prevent tear of the dura mater. Excessive blood loss is the bottom of the troughs. Osteotomy can be done in the usually encountered after the antidisplacement of the VOC, 1 3 1474 European Spine Journal (2018) 27:1469–1478 which can be easily controlled by the usage of hemostasis Table 1 Clinical pre and postoperative data of the patients materials. Before the closure of the wound, autogenous or Item Value allograft bone pieces were graft into the bilateral troughs to Age 62.6 ± 6.2 (52–78) obtain further fusion of the VOC with the surrounding bone. Sex Male 9, female 6 The bilateral longus colli were reconstructed to the anterior Symptom duration, months 36.5 ± 12.3 (2–240) plate by 3-0 silk sutures to cover the graft bones. Follow-up period, months 9.2 ± 1.6 (6–12) Levels with severe OPLL number of Postoperative immobilization patients  C3–C5 3 A halo vest is routinely used postoperatively for external  C3–C6 6 bracing for 3 months. The halo vest maintains the alignment  C4–C6 4 of the cervical spine to prevent failure of the internal fixation  C4–7 2 and enables early mobility of the patients. Operative time, min 173.2 ± 21.5 (120–230) Blood loss, ml 325.8 ± 43.5 (250–800) Statistical analysis JOA score  Before surgery 9.1 ± 2.5 (5–14) Statistical analysis was performed using SPSS [15]. Preop-  6 months after surgery 14.5 ± 1.2 (9–16)* erative and follow-up data such as JOA score, VAS score,  IR 6 months after surgery, % 65.2 ± 9.8 (44.4–88.9) OR, and SAC were compared using paired t test. The level VAS of significance was set at p < 0.05.  Before surgery 5.2 ± 1.6 (2–7)  6 months after surgery 2.4 ± 1.6 (0–5)* Complication, number of patients Results  C5 nerve root palsy 1  Postoperative hematoma 0 Clinicopathologic characteristics  CSF leakage 1  Implant complications 0 The study group included nine male patients and six female patients with a mean age of 62 years (range 52–78 years). Values are expressed as the mean ± standard deviation (range) The mean duration of follow-up was 9  months (range JOA Japanese Orthopaedic Association, IR improvement rate, VAS Visual Analog Scale, CSF cerebrospinal fluid 6–12 months). The spinal level of severe OPLL involve- *p < 0.05, compared with the data before surgery ment was C3–C5 for three patients, C3–C6 for six, C4–C6 for four, and C4–C7 for two. The mean time of symptom duration was 36 months (range 2–214 months). The mean operative time was 173  min (range Table 2 Radiological results of the patients 120–230 min), with the mean blood loss of 326 ml (range Item Value 250–800 ml). The mean JOA score increased from 9.1 ± 1.4 OR, % (range 5–14) at preoperation to 14.5 ± 1.2 (range 9–16) at  Before surgery 67.3 ± 5.1 (60 to 90) the 6-month follow-up (p < 0.05). The average improvement  After surgery 16.4 ± 6.5 (0 to 56)* rate (IR) was 65.2 ± 9.8%. Five (33.3%) patients were graded SAC, mm as excellent, seven (46.7%) as good, and three (20%) as fair.  Before surgery 4.5 ± 2.1 (1 to 7.5) The average VAS was 5.2 ± 1.6 (range 2–7) preoperatively,  After surgery 11.6 ± 2.7 (6 to 16)* 2.4 ± 1.6 (range 0–5) at the 6-month follow-up (p < 0.05). Cervical lordosis, ° All the patients felt immediate release of numbness in upper  Before surgery 3.7 ± 4.2 (− 7.5 to − 14) limbs. The clinical data is summarized in Table 1. After surgery 18 ± 4.7 (15 to 28)* Classification of OPLL (cases) Radiological results  Continuous type 5  Segmental type 3 The radiological outcomes are shown in Table 2. The OR  Mixed type 7 decreased from 67.3 ± 5.1% preoperatively to 16.4 ± 6.5% postoperatively, which was statistically significant Values are expressed as the mean ± standard deviation (range) (p < 0.05). SAC increased from 4.5 ± 2.1 mm preopera- OR occupation ratio, SAC space available for the cord, OPLL ossifica- tively to 11.6 ± 2.7 mm postoperatively, which was statisti- tion of the posterior longitudinal ligament cally significant (p  < 0.05). Postoperative cervical lordosis *p < 0.05, compared with the data before surgery 1 3 European Spine Journal (2018) 27:1469–1478 1475 was 18° ± 4.7° compared with preoperative 3.7° ± 4.2°. A the continuous OPLL in the cranial margin. In that case, fusion rate of 100% was achieved at 6-month follow-up. No lumbar drainage is performed at the second postopera- pseudoarthrosis exists were ensured by flexion and extension tive day and the CSF leak is then controlled and recovered views of lateral plain X-ray 6 months after the surgery. The 1 week after drainage. There was no occurrence of postop- imaging of a typical case is shown in Figs. 1 and 4. erative hematoma. No instrumented failure was observed during follow-up. No specific complications were identified Surgical complication that were associated with this technique. Transient minor neurological deterioration, manifesting with the weakness of right arm occurred in one case (6.7%) after Discussion operation due to the irritation of the nerve root when deal- ing with the massive ossification mass on the very lateral of Although anterior and posterior decompression surgery are C4/5 segment. The weakness in right arm improved signifi- both reported to treat patients with myelopathy caused by cantly 2 weeks following the surgery. The muscle strength of OPLL, controversy still exists over the surgical options. the right arm was improved to 4+ at the 6 months follow-up. The posterior decompression surgery can safely achieve the The CSF leak occurred in one case (6.7%) during transecting decompression of the spinal cord that results from extensive Fig. 4 A 57-year-old female presented with walking disturbance and of the VOC at C3 (b), C5 (c), and C6 (d). e Preoperative sagittal MRI dysfunction of sensation of lower limbs without other complains. (left) shows severe compression of the spinal cord from C3 to C6, and After ACAF from C3 to C6, She had neurologic improvement and postoperative sagittal MR image (right) shows sufficient decompres- JOA score increased from 13 to 16 points with an improvement rate sion of the spinal cord. f Preoperative axial MRI (up) and postoper- of 75%. a Preoperative sagittal CT image (left) shows a massive ative axial MRI (down) shows decompression of the spinal cord. g mixed type OPLL at C2–5 and C6, and postoperative sagittal CT Preoperative (left) and postoperative (right) lateral tomograph. ACAF image (right) shows the ossification was transected behind the C2, anterior cervical corpectomy and fusion, JOA Japanese Orthopedic and the C3–7 VOC was hoisted and fused to an antedisplaced loca- Association, CT computed tomography, OPLL ossification of the tion. Preoperative axial CT image (up) and postoperative axial CT posterior longitudinal ligament, VOC vertebrae-OPLL complex, MRI image (down) shows the massive OPLL mass and antedisplacement magnetic resonance images 1 3 1476 European Spine Journal (2018) 27:1469–1478 OPLL. However, there are limitations in posterior decom- enough decompression to the bilateral nerve roots. The pression surgery, it does not always produce the expected antidisplacement of the VOC further lead to direct and space for cases with a highly narrowed spinal canal or a bad thorough decompression of the spinal cord. The outcome lordosis [16, 17]. Furthermore, the posterior decompression of the ACAF relies on the complete isolation and anti- surgery is accused of higher incidence of C5 palsy, postop- displacement of the VOC, which require thorough pre- erative kyphotic change, and postoperative progression of operative designing, proper selection and installation of the ossified OPLL lesion in many studies [18– 20]. Ante- internal fixation devises, and intraoperative evaluation and rior corpectomy and resection of OPLL can achieve direct trimming of the VOC. Goel et al. reported that stand-alone decompression and gain satisfactory results, especially in fixation resulted in dramatic and sustained neurological cases with highly narrowed spinal canal and short segmental recovery of OPLL. The authors proposed that instabil- OPLL [21]. However, in this high technically demanding ity plays a role in the pathogenesis and development of surgery, the risks of excessive hemorrhage, iatrogenic dam- symptoms related to myelopathy of OPLL. As in ACAF, age to neural tissue, and CSF leakage are reported as fre- the satisfactory clinical recovery may also come from the quently occurring complications [22, 23]. In 1999, Yamaura stabilization and fusion of the spinal segments [27]. et al. reported the anterior decompression surgery with float- CSF leakage is one of the most frequently met compli- ing method for cervical OPLL [24]. The method minimizes cations of the anterior decompression surgery for OPLL surgical invasion and the risk of hemorrhage, spinal cord [28]. In the ACCF surgery, the direct decompression is damage, and leakage of CSF in traditional anterior decom- accomplished by resecting the OPLL in a piecemeal or pression surgery. However, the anteriorly migration of the enbloc pattern. During the resection of OPLL, the adhe- OPLL in floating method is not controlled by surgeon and sion or ossified dura is vulnerable and dural tear is always much owing to the pressure of the CSF, which requires as encountered. Especially when there is a big area of ossified long as 8 weeks for the ossification to complete the migra- dura, the direct resection will lead to a big absence of dura tion [25]. Thus, the impingement between OPLL and the and refractory postoperative CSF leak. The advantage of surrounding bone cannot be foreseen during the procedure ACAF is that it does not need to deal with the adhesion of and often results in incomplete floating of the OPLL [26]. the dura and OPLL or ossified dura. Isolation of the VOC Intraoperative CT scan was used to ensure that the VOC is conducted on the lateral side of the OPLL. In cases that was isolated prior to the hoist. Intraoperative CT scan was the OPLL excess the lateral or caudocranial border of the also used in the floating method to avoid insufficient decom- VOC, separation of the dura and OPLL is required. But pression [26]. However, the intraoperative CT scan is not the in this circumstance, the separation of dura and OPLL only way to know if the VOC is fully isolated, surgeon could is safer because it is near the border of OPLL where the also use a nerve hook to detect the border of the VOC. The adhesion and compression are both mild. There were 6.7% space for hoist can also be measured using a depth detector patients with CSF leakage in this study, which was lower when bridge was set. So the intraoperative CT scan is not a than that in anterior decompression and higher than the must-have in any procedure in the ACAF technique. The use posterior decompression [29, 30]. of the O-arm was useful in initial cases but was omitted from Many studies have reported that the blood loss is larger subsequent cases in a bid to reduce radiation for the patient. in anterior decompression surgery than that in posterior The idea of ACAF is to isolate and “actively transport” decompression surgery. The massive compression in the spi- the OPLL ventrally to restore the space of the spinal canal nal canal obstructs the vein drainage and lead to excessive and thus achieve direct decompression of the neural ele- blood loss, which is one of the reasons for unclear surgical ments with their location unchanged. The remaining verte- view and inadequate decompression [31]. bral body and OPLL mass are then served as an autogenous In our practice, the average blood loss is 328 ml in aver- bone for the reconstruction of the anterior column. Different age and no postoperative hematoma occurred. In ACAF, the from the floating method, in ACAF the antidisplacement of VOC provides as an ideal anchor site for hemostatic materi- the OPLL is achieved under the gradual hoisting force of the als such as bone wax and gel foam. Another important fact anterior plate and screws with an immediate feedback. The is that the present of VOC occupies the potential space for Bridge Crane device is vital in this technique, for it stabilizes the formation postoperative hematoma. the VOC in the procedure of osteotomy and gives the sur- The current study has several limitations. Neurologic geon full control in the procedure of VOC antidisplacement. recovery, occurrence of complications, blood loss, and As shown in the results, the patients who underwent operative time of ACAF could not be directly compared ACAF have all gained satisfactory outcome. The anatomic with those associated with other anterior decompression sur- basic for the clinical effect of ACAF lays in the direc- gery or posterior decompression surgery. Prospective, ran- tor decompression for spinal cord and nerve roots. The domized, controlled studies may be required to adequately procedure of bilateral osteotomies of the vertebrae gives investigate these issues. And long-term follow-up is needed 1 3 European Spine Journal (2018) 27:1469–1478 1477 8. Chen Y, Yang L, Liu Y et al (2014) Surgical results and prognostic to evaluate the long-term outcome and progression of the factors of anterior cervical corpectomy and fusion for ossification ossification. of the posterior longitudinal ligament. PLoS One 9(7):e102008 Our current study has shown that multilevel severe OPLL 9. Shinomiya K, Matsuoka T, Kurosa Y et al (2006) Anterior cervi- with myelopathy can obtain a safe and sufficient decompres- cal decompression for cervical myelopathy caused by ossification of the posterior longitudinal ligament (OPLL). Springer, Tokyo, sion using the novel ACAF technique. The antidisplacement pp 209–218 procedure is controlled using a “bridge crane” device, which 10. Pitzen T, Chrobok JJ, Ruffing S et al (2009) Implant complica- eliminates the need for direct resection of the OPLL, there- tions, fusion, loss of lordosis, and outcome after anterior cervical fore, reducing the risk of injury to the dura and spinal cord. plating with dynamic or rigid plates: 2-year results of a multi- centric, randomized, controlled study. Spine 34(7):641–646 No specific complications were identified that were associ- 11. Hirabayashi K, Watanabe K, Wakano K et al (2001) Expansive ated with this technique. As the procedure described in this open-door laminoplasty for cervical spinal stenotic myelopathy. technique is not technically demanding, it should be consid- Spine 8(7):693 ered when dealing with cases of multilevel severe OPLL. 12. Iwasaki M, Kawaguchi Y, Kimura T et al (2002) Long-term results of expansive laminoplasty for ossification of the posterior longi- tudinal ligament of the cervical spine: more than 10 years follow Acknowledgements The technique is designed and performed by the up. J Neurosurg 96(2 Suppl):180 corresponding author Dr. Jiangang Shi. We express deep thanks to the 13. Fujimori T, Iwasaki M, Okuda S et al (2014) Long-term results illustrator Xiaomu Zhao. We thank Zhen Huang and Qi Zhang for their of cervical myelopathy due to ossification of the posterior longi- technical support of intraoperative CT. tudinal ligament with an occupying ratio of 60% or more. Spine 39(1):58 Funding This study was supported by Grants from the National Natural 14. Petty P (1997) Surgical anatomy of the anterior cervical spine: Science Foundation of China (No. 81650031) and Shanghai Municipal the disc space, vertebral artery, and associated bony structures. Commission of Health and Family Planning (No. 201640262). Neurosurgery 41(1):769–776 15. SPSS (Computer program) (2009) Version 18.0. SPSS Inc, Compliance with ethical standards Chicago 16. Baba H, Furusawa N, Chen Q et al (1995) Cervical laminoplasty in patients with ossification of the posterior longitudinal liga- Conflict of interest None of the authors has any potential conflict of ments. Paraplegia 33(1):25–29 interest. 17. Lee DH, Joo YS, Hwang CJ et al (2016) A novel technique to correct kyphosis in cervical myelopathy due to continuous-type Open Access This article is distributed under the terms of the Creative ossification of the posterior longitudinal ligament. J Neurosurg Commons Attribution 4.0 International License (http ://crea tive comm Spine 26(3):1 ons.org/licenses /b y/4.0/), which permits unrestricted use, distribution, 18. Sakaura H, Hosono N, Mukai Y et al (2003) C5 palsy after decom- and reproduction in any medium, provided you give appropriate credit pression surgery for cervical myelopathy: review of the literature. to the original author(s) and the source, provide a link to the Creative Spine 28(21):2447–2451 Commons license, and indicate if changes were made. 19. Lee SE, Chung CK, Jahng TA et al (2013) Long-term outcome of laminectomy for cervical ossification of the posterior longitudinal ligament. J Neurosurg Spine 18(5):465–471 20. Kato Y, Iwasaki M, Fuji T et  al (1998) Long-term follow-up References results of laminectomy for cervical myelopathy caused by ossi- fication of the posterior longitudinal ligament. J Neurosurg 1. Epstein N (2002) Diagnosis and surgical management of cervi- 89(2):217–223 cal ossification of the posterior longitudinal ligament.[J]. Spine J 21. 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J the ideal treatment for ossified posterior longitudinal ligament? Bone Jt Surg 87(3):610 (American Volume) Report of early results with a preliminary experience in 14 30. Hannallah D, Lee J, Khan M et al (2008) Cerebrospinal fluid patients. World Neurosurg 84(3):813–819 leaks following cervical spine surgery. J Bone Jt Surg Am 28. Cho JY, Chan CK, Lee SH et al (2012) Management of cerebro- 90(5):1101–1105 spinal fluid leakage after anterior decompression for ossification 31. Lin D, Ding Z, Lian K et al (2012) Cervical ossification of the pos- of posterior longitudinal ligament in the thoracic spine: the utiliza- terior longitudinal ligament: anterior versus posterior approach. tion of a volume-controlled pseudomeningocele. J Spinal Disord Indian J Orthop 46(1):92 Tech 25(4):E93 29. Belanger TA, Roh JS, Hanks SE et  al (2005) Ossification of the posterior longitudinal ligament Results of anterior cervical Affiliations 1 1 1 1 1 1 1 Jingchuan Sun  · Jiangang Shi  · Ximing Xu  · Yong Yang  · Yuan Wang  · Qingjie Kong  · Haisong Yang  · 1 1 2 1 1 1 Yongfei Guo  · Dan Han  · Jingjing Jiang  · Guodong Shi  · Wen Yuan  · Lianshun Jia * Jiangang Shi Department of Anaesthesiology, Changzheng Hospital, shijiangang616@163.com Shanghai, China Department of Spine Surgery, Changzheng Hospital, 601 Room, 415# Fengyang Road, Huangpu District, Shanghai, China 1 3

Journal

European Spine JournalSpringer Journals

Published: Dec 28, 2017

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