Zone II Flexor Pollicis Longus Repair: Thumb Flexion and Complications

Outcome of Flexor Tendon Repair Using Eight-Strand Core Stitch Without Postoperative Finger Splinting

BACKGROUND

There are no reports that detail clinical outcomes using the 8-strand suture techniques and early active mobilization. We aim to report the outcome of using an 8-strand double-cruciate core suture followed by early active motion without finger splinting.

MATERIALS AND METHODS

Thirty-five patients with 41 affected digits were operated and followed up for at least 6 months. A double cruciate repair with 4 single cross-grasping stitches on either side was employed. Active full-range finger flexion/extension exercises were allowed from the third postoperative day with the wrist held in the neutral position.

RESULTS

The total active motion (TAM) calculated for the proximal interphalangeal and distal interphalangeal joints averaged 151° ± 22°, and the TAM% averaged 86% ± 13%. Based on the original Strickland-Glocovac criteria, excellent and good outcomes were achieved in 25 of 29 fingers (86.2%). An average extension lag of 21° ± 11° (range 10°-40°) was observed in 11 (38%) fingers. The Buck-Gramcko scale showed excellent and good results in 10 (83.4%) thumbs. Active interphalangeal range of motion averaged 68° ± 23°. An average extension lag of 12° ± 4° (range 10°-20°) was observed in 7 (58%) thumbs. Complications occurred in 4 thumbs, including bowstringing (2), rupture (1), and flexion contracture of 60° (1).

CONCLUSIONS

Using the 8-strand repair technique and active mobilization performed by the patient is both practical and cost-saving. Intensive supervision of a hand therapist is generally not required. Notably improved outcomes have been achieved while preventing adhesions at the repair site. Further clinical outcome studies devoted specifically to the flexor pollicis longus are recommended to validate early-phase active mobilization following the 8-strand repair.

Electrospun tube reduces adhesion in rabbit Achilles tendon 12 weeks post-surgery without PAR-2 overexpression

One great challenge in surgical tendon repair is the minimization of peritendinous adhesions. An electrospun tube can serve as a physical barrier around a conventionally sutured tendon. Six New Zealand White rabbits had one Achilles tendon fully transsected and sutured by a 4-strand suture. Another six rabbits had the same treatment, but with the additional electrospun DegraPol tube set around the sutured tendon. The adhesion formation to the surrounding tissue was investigated 12 weeks post-operation. Moreover, inflammation-related protease-activated receptor-2 (PAR-2) protein expression was assessed. Finally, rabbit Achilles tenocyte cultures were exposed to platelet-derived growth factor-BB (PDGF-BB), which mimicks the tendon healing environment, where PAR-2 gene expression was assessed as well as immunofluorescent staining intensity for F-actin and α-tubulin, respectively. At 12 weeks post-operation, the partially degraded DegraPol tube exhibited significantly lower adhesion formation (- 20%). PAR-2 protein expression was similar for time points 3 and 6 weeks, but increased at 12 weeks post-operation. In vitro cell culture experiments showed a significantly higher PAR-2 gene expression on day 3 after exposure to PDGF-BB, but not on day 7. The cytoskeleton of the tenocytes changed upon PDGF-BB stimulation, with signs of reorganization, and significantly decreased F-actin intensity. An electrospun DegraPol tube significantly reduces adhesion up to twelve weeks post-operation. At this time point, the tube is partially degraded, and a slight PAR-2 increase was detected in the DP treated tendons, which might however arise from particles of degrading DegraPol that were stained dark brown. PAR-2 gene expression in rabbit tenocytes reveals sensitivity at around day 10 after injury.