Archives of Orthopaedic and Trauma Surgery (2018) 138:325–330
Functional outcomes after removal of hardware in patellar fracture:
are we helping our patients?
· Assaf Kadar
· Michael Drexler
· Zachary T. Sharfman
· Or Chechik
· Ely L. Steinberg
Received: 22 May 2017 / Published online: 28 November 2017
© Springer-Verlag GmbH Germany, part of Springer Nature 2017
Purpose Functional outcomes after Open Reduction Internal Fixation (ORIF) of the patella are variable. Common complica-
tions of patella ORIF include persistent anterior knee pain, limited range of motion and symptomatic hardware. The purpose
of this study was to evaluate if removal of hardware is beneﬁcial to symptomatic patients after patellar fracture ﬁxation.
Methods Patients who presented to our institution between December 2006 and November 2014 with patella fractures treated
with ORIF were eligible for inclusion. Patella ORIF was performed using (1) K-wires (KW) with a tension band construct
or (2) Cannulated Screws (CS) with a tension band construct. Radiological analyses included (1) AO classiﬁcation and (2)
measurements of prominent hardware length. Patient medical charts were reviewed for demographic and intraoperative
data as well as peri/postoperative complications. All patients completed the SF-12 score, visual analog scale, Kujala score,
Lysholm score and questionaries’ regarding return to previous activity levels.
Results Forty-seven patients met the inclusion criteria. The average time from fracture ﬁxation to removal of hardware was
15.8 (SD ± 14.9) months. The mean follow-up was 43.1 (SD ± 27.1) months. Patella ﬁxation was accomplished using ten-
sion band constructs with KW in 28 patients (59.5%) or with CS in 19 patients (40.5%). Patient reported quality of life and
pain outcomes improved signiﬁcantly after removal of hardware (p = 0.001, and p = 0.002 respectively). Functional outcome
scores (Kujala and Lysholm) did not improve signiﬁcantly after hardware removal in the KW or CS groups. Signiﬁcantly
more patients in the KW group returned to pre-injury activity (p = 0.005).
Conclusions Hardware removal after patella ORIF signiﬁcantly improves patient reported pain and quality of life outcomes
but not functional outcomes. Patients should be counseled regarding the expected outcome of hardware removal following
patella ORIF and diabetic patients should be given special consideration before undergoing this procedure.
Keywords Functional outcome · Patellar fractures · Hardware removal · Quality of life
Patellar fractures account for 1% of all fractures in the adult
population [1–4]. Surgical intervention with Open Reduction
Internal Fixation (ORIF) is recommended for patients with
displaced patellar fractures and disrupted extensor mecha-
nisms [4, 5]. Due to the superﬁcial nature of the patella and
current patella ﬁxation techniques patient often complain
of symptomatic hardware after ORIF of patella fractures.
The potential for symptomatic hardware contributes to the
diﬃculty in treating these fractures. Hardware failure and
nonunion are thought to be relatively rare following patella
ORIF ; however, residual pain and symptomatic hardware
remain major setbacks for these patients [7, 8].
Functional outcomes after ORIF are variable and the
complications of these procedures include persistent ante-
rior knee pain, limited range of motion and symptomatic
hardware [6–8]. Multiple studies report that 10–50% of all
patella ORIF patients will undergo a secondary operation
for removal of hardware [3–6]. Several studies have reported
outcomes after patella ORIF [5, 6], and other studies have
aimed to predict factors predisposing to removal of hardware
after patella ORIF [6, 9–11]. However, there is limited data
* Nimrod Snir
Joint Arthroplasty and Sports Medicine Department, Tel
Aviv Sourasky Medical Center, Aﬃliated with the Sackler
Faculty of Medicine, Tel Aviv University, 6 Weitzman
Street, 6423906 Tel-Aviv, Israel