European Journal of Orthopaedic Surgery & Traumatology
ORIGINAL ARTICLE • WRIST - FRAC TUR ES
Treatment of the distal radius fractures with percutaneous pinning:
evolution to the HK2 system
Emmanuel J. Camus
· Luc Van Overstraeten
Received: 2 May 2018 / Accepted: 6 May 2018
© Springer-Verlag France SAS, part of Springer Nature 2018
Displaced fractures of the distal radius often require reduction and ﬁxation to improve outcome in active patients. The volar
locking plate gained ground over pinning, which was the ﬁrst surgical solution described. But pinning methods have since
evolved with fewer complications. The authors present a clinical study of distal radius fracture ﬁxation using the HK2 tech-
nique, where subchondral pins are connected to intra-focal pins. The results are satisfactory with a lower complication rate
compared to other pinning methods. This technical improvement relaunches the pinning technique, with its two advantages,
being faster and signiﬁcantly cheaper than locking plates, with similar long-term functional results.
Keywords Fracture · Distal radius · Pinning · Wire · Kapandji · HK2
Fractures of the distal radius are the second most frequent of
the human skeleton and occur at any age . They directly
aﬀect the function of the wrist, and therefore of the hand.
Consolidation disorders, usually malunion, can lead to a
signiﬁcant disability . Casting does not prevent second-
ary displacement in 75% of cases and signiﬁcant malunion
in 25% of cases . Surgical treatment of these fractures
therefore seems necessary in order to avoid, or correct, dis-
placement and preserve function.
Pinning was the ﬁrst surgical treatment proposed and has
regularly evolved . However, it is in competition with
other techniques, notably external ﬁxation and plate ﬁxation,
which seems to have gained ground . Does pinning still
have any beneﬁt then?
Historical surgical methods
Pinning is still the subject of numerous publications, show-
ing that it is still a very much used technique. Extra-focal
pinning was initially described by Lambotte in 1908 .
The basic principle consists of bridging the fracture with
percutaneous pins inserted through the epiphysis, from distal
to proximal (Fig. 1a). While this method improves stability
compared to casting, it still lacks rigidity . The displace-
ment stresses on the pins at the point of application of the
epiphysis act away from the fracture line, which represents
the center of rotation. This creates a lever arm, capable of
deforming the wires (Fig. 1b).
Kapandji’s intra-focal pinning  proposed to “prevent
any secondary displacement” by “doing without any cast
immobilization”. Kapandji’s analysis was that “in conven-
tional radius pinning, the wires, even of good calibre, have
a certain elasticity, can bend until they come to rest on the
edge of the diaphyseal fragment, and one then sees the exter-
nal displacement and the posterior rocking occurring again.
Under these conditions, (…) logic suggests that the wires
pass immediately through this stop point, without the need
to rely on its rigidity” .
Intra-focal pinning consists of inserting a lateral, and one
or two posterior wires through the fracture line, and ﬁxing
them proximally in the metaphysis at a 45° angle (Fig. 2a).
This cancels out the epiphyseal lever between the stress
* Emmanuel J. Camus
Clinique du Val de Sambre, 162 Route de Mons, Maubeuge,
Clinique de Lille Sud, 96 rue Gustave Delory, Lesquin,
Hand and Foot Surgery Unit, Rue Pierre Caille 9, Tournai,
ULB Brussels Free University, Route de Lennik 808,