Commentary on "reattachment of flexor digitorum profundus avulsion: biomechanical performance of 3 techniques". Zone I flexor tendon repairs: more strength not worth altered joint kinematics

Pull-out vs. suture in zone Ia-Ib flexor tendon injuries: clinical results from a multicentre cohort study

BACKGROUND

Several surgical techniques have been reported for flexor tendon zone 1a-b lacerations without a clear consensus on the gold standard treatment. The purpose of this multicentre study was to measure the outcomes of zone 1a-b flexor tendon injuries treated with a pull-out suture (POS) versus direct suture (DS) technique.

PATIENTS AND METHODS

Fifteen patients were treated with the pull-out technique and 22 patients with a direct suture technique between 2014 and 2020. The controlled active motion (CAM) regimen protocol and a standardised follow-up schedule were used in both groups. Data on the demographics, surgery, and treatment characteristics were collected at baseline as well as at week 6 and 13 post-operatively. The primary outcome measurement was the complication rate. Secondary outcome measurements were reoperation rate, finger range of motion (ROM), strength as well as patient satisfaction.

RESULTS

The patient age ranged from 18 to 75 years in both groups with all patients having a complete FDP lesion after a clean-cut injury. The complication rate was 41% in the POS group and 16% in the DS group. The reoperation rate was 29% in the POS group and 8% in the DS group. Significant between-group differences in favour of the DS group were found in the passive DIP and passive PIP+DIP ROM at week 6 and week 13. Mean hand strength was 28.7 (11.6) kg in the POS group at week 13 and 21.3 (7.9) kg in the DS group. This difference was statistically significant (p=0.012) with a medium effect size (r=-0.41). Average patient satisfaction at week 13 was 7.5 (2.2) points in the POS and 7.7 (1.3) points in the DS group. The difference between groups was not significant (p=0.839).

CONCLUSION

This register-based study demonstrates lower complication and reoperation rates with the direct suture approach compared with a pull-out button technique. Although clinical results were similar between the two surgery techniques at week 13 post-surgery, a direct suture approach should always be attempted whenever possible. If necessary, other local structures should be included to increase suture strength and allow for early active motion rehabilitation regimens.

Use of the Volar Plate of the Distal Interphalangeal Joint as a Distally Based Flap in Flexor Tendon Surgery

The usual treatment for flexor digitorum profundus (FDP) avulsions as well as FDP lacerations in the distal part of zone I is tendon reinsertion into bone. Although there are several different techniques of FDP tendon reinsertion into bone, they are generally complex and have a weak tensile strength. A technique for treating these injuries is to use the volar plate of the distal interphalangeal joint as a distally based flap for tendon repair. The current communication discusses the technique and its potential complications. Initial clinical experience is encouraging and the volar plate flap technique may take its place in flexor tendon surgery.