Arch Hand Microsurg.  2024 Dec;29(4):220-229. 10.12790/ahm.24.0045.

Efficient repair of the flexor digitorum profundus tendon at the insertion site using the loop suture technique: a case series

• Kim JW
• Kim JS
• Roh SY
• Lee KJ
• Lee DC

• KMID: 2561370
• DOI: http://doi.org/10.12790/ahm.24.0045

Abstract

Purpose
This study presents the outcomes of a modified loop-locking suture technique for repairing complete flexor digitorum profundus (FDP) tendon divisions at the terminal level. Traditional methods, such as pullout sutures or tendon fixation, are commonly used; however, this paper explores the reliability of the loop-locking suture technique.
Methods
From June 2011 to January 2024, the modified loop-locking suture technique was performed in 21 cases of FDP tendon division in which the distal stump was less than 1 cm in length. Core and epitendinous sutures were made using polydioxanone 4-0 and poliglecaprone 25 4-0. The study focused on 13 patients aged 24 to 68 years, with an average tendon stump length of 0.61 cm. Ten cases necessitated microsurgical repair involving both arterial and nerve repair. A dorsal protective splint was used for an average of 5 weeks. The outcomes measured included active and passive range of motion, grip strength, and key and pulp pinch.
Results
The mean follow-up period was 12 months. No re-ruptures occurred, although two cases required tenolysis. The average active range of motion at the distal interphalangeal joint was 61.5°. Grip strength and pulp pinch averaged 95.3% and 86.8%, respectively, compared to the contralateral side. Flexion contracture was observed in three cases, with no quadriga effect.
Conclusion
The modified loop-locking suture technique provides sufficient functional recovery for FDP tendon divisions in Zone 1a and distal Zone 1b, even with a short tendon stump.

Keyword

Flexor digitorum profundus; Tendon repair; Loop-locking suture technique; Zone 1a

Figure

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  Fig. 1. Subdivision of Zone 1 flexor tendon injuries. Reproduced from Moiemen and Elliot [2] with permission of Sage.

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  Fig. 2. Different techniques used for distal fixation of the tendon. (A) Two-strand transosseous pullout wire suture with a wire ring bolster+second (volar) transcutaneous suture to aid removal of the main wire suture (by Bunnell) [3]. (B) Mitek mini GII suture anchor (Ethicon, Somerville, NJ, USA) (by Hallock) [4]. (C) Acufex suture anchor (Smith & Nephew, London, UK) (by Skoff et al.) [5]. (D) Two-strand transosseous suture (by Sood and Elliot) [6]. (E) Two-strand transosseous wire suture (by Schultz et al.) [7]. (F) Two-strand transosseous pullout suture over the button (button held away from the skin by Kirschner wire) (by Grant et al.) [8].

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  Fig. 3. Loop-locking suture technique. A loop is applied to each distal and proximal part of the tendon, respectively.

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  Fig. 4. Case 1. (A) A 26-year-old man with complete division of the flexor digitorum profundus (FDP) tendon in the insertion site. (B) First, the repair is done on the distal stump of the divided FDP tendon with polydioxanone 4-0. (C, D) One loop is applied to the distal stump of the FDP. (E) A two-strand core suture with a single locking suture per strand was performed. (F) The repair is completed using the loop technique and epitendinous suture.

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  Fig. 5. Case 1. Postoperative view of the patient 12 months after tenorrhaphy. (A) No extension lag of the middle finger. (B) Active flexion.

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  Fig. 6. Case 2. (A) A 32-year-old woman shows complete division at the flexor digitorum profundus (FDP) insertion site of the left index finger by scissors. The distance to the distal tendon end from the insertion site is 0.6 cm. The proximal part of the divided FDP tendon is retracted to the distal end of the A4 pulley. (B) Postoperative view of the patient 20 months after tenorrhaphy.

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  Fig. 7. Two-strand side-locking loop technique. After the transverse component of the suture is placed, a loop is made in the side of the tendon. Then, the vertical component of the suture penetrates the tendon from the back to the front, slightly distal from the transverse component. Thus, the locking configuration can be easily seen from the front. A knot is buried inside the tendon [26].

Reference

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