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Page 6 of 25 Bertolini et al. Plast Aesthet Res 2023;10:34 https://dx.doi.org/10.20517/2347-9264.2022.121

Pulleys Reconstruction
The pulley system optimizes the action of the flexor tendons, keeping the tendon close to the phalanges;
[33]
furthermore, it converts tendon gliding into joint excursion . Damage to the pulleys results in tendon
bowstringing, which reduces the effectiveness of active flexion and requires more muscle effort [34,35] .
Preservation of the original pulleys is always more advisable than reconstruction and it may allow a single-
stage procedure. In particular, even though preservation or reconstruction of A2 and A4 pulleys is
recommended [36,37] , it has currently been shown that the A4 pulley can be sacrificed during acute tendon
repair if A2 pulley is safe. However, it has not yet been clarified whether the same concept is applicable in
the reconstructive setting . Several reconstructive techniques involve the use of the damaged tendon, a
[38]
tendon graft, or the extensor retinaculum. These techniques involve creating a loop around the phalanx or
pulling the graft through remnants of the pulleys. The technique, according to Klinert/Weilby, creates a
[39]
weave of the tendon graft over the edges of the native pulley . The tendon graft can also be intrasynovial,
thus involving the use of a slip of FDS or extensors retinaculum; according to some authors, this would
improve tendon glide [40,41] . Another procedure is the "belt-loop" technique described by Karev, according to
which the graft constituting the pulley passes through a tunnel in the volar plate . In addition, several
[42]
techniques for pulley reconstruction are based on creating a loop around the phalanx: while Lister envisions
a single loop using the extensor retinaculum, Okutsu describes the triple-loop technique (preferred by the
author) and Widstrom the loop-and-a-half technique [43-45] . Reconstruction, according to Lister, seems to
[36]
lead to better tendon gliding, perhaps because of the intrasynovial graft . On the other hand, the
techniques involving loops around the bone appear to be the strongest, particularly the one outlined by
[46]
Okutsu, which is recommended in A2 pulley reconstruction [Figures 2 and 3].

Outcomes and complications
The goal of flexor tendon reconstruction is to restore function with good recovery of flexion-extension;
however, the results are often poor compared to primary repair. There is no standardized evaluation system,
but several have been described: total active motion (TAM), strength assessment, Stickland's or Schneider's
modified grading system [1,2,7,47] . Heterogeneous results have been reported in the literature; using
intrasynovial grafts and early active mobilization, Leversedge describes 64% and 55% active ROM recovery
for single-stage and double-stage reconstructions, respectively. Better results with 73% active ROM recovery
have been described for single-finger reconstructions . In contrast, Coyle et al. achieved 91% active motion
[2]
recovery with a double-stage technique; however, they confronted a 9% rupture rate and the need for
secondary tenolysis at 6% . Karakaplan et al., after a two-staged reconstruction of flexor tendon injuries in
[3]
Zone II in 10 patients, reported good to excellent results in 60% of the cases. They also recorded one case of
tenolysis. The most frequent complication following tendon reconstruction is adhesion formation: in
particular, the relevant literature reports a rate of adhesions from 12% to 47% [1,48,49] . For this reason, an
appropriate postoperative protocol is essential. Rehabilitation should promote graft gliding, thus preventing
adhesion formation and loss of function. There is no standardized rehabilitation protocol; reportedly, the
splint may be removed after a period of 5 days to 5 weeks . Early active mobilization has been shown to
[24]
promote healing by inducing collagen type III production and reducing adhesion formation [50-52] . Adhesion
formation may result in the need for subsequent tenolysis; however, at least six months of intensive
rehabilitation are recommended before secondary surgery . A poor surgical technique or excessive
[30]
mobilization can result in tendon repair rupture; this occurs in 3% to 9% of patients, and the greatest risk is
recorded 10-12 days after surgery . Rupture can occur on the proximal or distal side of the suture, and
[53]
sometimes it can occur intra-substance. A primary repair can be performed if this adverse event occurs in
the first few weeks after the repair; otherwise, if the soft tissue condition does not allow it, the procedure can
be converted to a two-staged procedure. If the rupture involves only the FDP and the FDS is intact, an
arthrodesis of the distal interphalangeal joint or a tenodesis of the FDP on the FDS can be performed [30,54] .
Joint contractures in flexion, particularly at the PIP, are a frequent complication that can occur in up to 40%