Journal of Hand Surgery (European Volume)

We retrospectively reviewed the outcomes of flexor tendon repairs in zones 1, 2 and 3 in 356 fingers in 291 patients between 2005 and 2010. The mean (standard deviation) active ranges of motion of two interphalangeal joints of the fingers were 98° (40) and 114° (45) at 8 weeks postoperatively and at the last follow-up (mean 7 months, range 3–98), respectively. Using the Strickland criteria, ‘excellent’ or ‘good’ function was obtained in 95 (30%) out of 322 fingers at 8 weeks and 107 (48%) out of 225 fingers at the last follow-up. A total of 48 (13%) fingers required reoperation because of rupture, adhesion, contracture or other complications. The prevalence of rupture was 4%. We carried out multiple linear regression analysis to identify the predictors of the active digital motion. The following variables were found as negative predictors: age; smoking; injury localization between subzones 1C and 2C; injury to the little finger; the extent of soft tissue damage; concomitant skeletal injury; delay to surgery; use of a 2-strand Kessler repair technique; attempted suture or preservation of the tendon sheath–pulley system; and resecting or leaving the concomitant superficial flexor tendon cuts untreated. Analysing the 8 weeks results of tendon repairs in zones 1 and 2, early active mobilization was found to be superior to Kleinert’s regime.

Level of evidence: III

Under cyclic loading, we recorded the fatigue strength of a six-strand tendon repair with different symmetry in the lengths of suture purchase in two stumps of 120 dental rolls and in 30 porcine tendons. First, the strengths of the repairs with 1, 2, 3, 4 and 5 mm asymmetry were screened using the dental rolls. The asymmetric core suture repairs were then made with a Kessler repair of equal suture purchase (10 mm) in two tendon stumps, and shifting two other Kessler repairs by 1, 3 or 5 mm, respectively, along the longitudinal axis of the tendon in relation to the first (symmetric) Kessler repair. The core repairs with 3 mm or more asymmetry in suture purchases in two tendon ends showed significantly greater fatigue strength and significantly smaller gaps compared with 1 mm asymmetry in core suture repair. Our results support that asymmetric placement of core sutures in two tendon ends favour resisting gapping at the repair site and 3 mm or more asymmetry is needed to produce such beneficial effects.

We divided 21 flexor digitorum profundus tendons in the index, middle and ring fingers in seven cadaver hands into three groups. The tendons were cut in zone 2 and repaired using a 4-strand cruciate core suture repair with one of the following three materials in each group: (1) a knotless repair with a 2-0 bidirectional-barbed suture, which has similar tensile strength as a 4-0 non-barbed suture used in the other two groups; (2) a knotted locking repair with a non-barbed 4-0 conventional suture; and (3) a non-locking repair with a non-barbed 4-0 knotless suture. The repaired fingers were cyclically loaded through a simulated active range of motion to a 5 N load. We monitored and recorded the gap sizes at regular intervals during the test. The 2-0 bidirectional-barbed suture group and non-barbed suture groups developed gaps of 2.2 mm after 10 cycles and 2.4 mm after 20 cycles, respectively. Over 1000 cycles, the mean gaps were 3.2 mm in the 4-0 conventional suture group and 9.1 mm in the 2-0 bidirectional-barbed group. The tendons in the 2-0 bidirectional-barbed group gapped earlier, with statistically significant differences compared with those in the locking repair with a non-barbed 4-0 knotless suture group. The repair strength of the barbed suture technique was inferior to the cruciate repairs using a conventional 4-0 non-barbed suture tested in this cyclic-loading model.

Level of evidence: Level V

This biomechanical study compared the original Al-Qattan repair with other modifications postulated to reduce bulk and friction, thereby potentially improving outcome. A total of 32 cadaveric digits with intact flexor apparatus were used. In each digit, the flexor digitorum profundus and flexor digitorum superficialis tendons were cut cleanly in Zone 2. We tested Al-Qattan’s technique along with three modifications using stronger suture material and varying the number of strands across the repair site. Of the four repair techniques, the modified Al-Qattan’s technique using two ‘figure of 8’ 4-0 Fiberwire core sutures (Group 4) had the best balance of ultimate tensile strength (50.9 N), 2 mm gapping force (38 N) and friction. The modified technique provided a stronger repair for early active mobilization and has less friction than the originally described repair.

We report the results of complete release of the entire A2 pulley after zone 2C flexor tendon repair followed by early postoperative active mobilization in seven fingers and their comparisons with 33 fingers with partial A2 pulley release. In seven fingers, release of the entire A2 pulley was necessary to allow free gliding of the repairs in five fingers and complete release of both the A2 and C1 pulleys was necessary in two. No bowstringing was clinically evident in any finger. Two fingers required tenolysis. Using Tang’s criteria, the function of two digits was ranked as excellent, four good and one fair; there was no failure. The functional return in these seven fingers was similar with that in 33 fingers with partial A2 pulley release; in these patients only one finger required tenolysis. Our results support the suggestion that release of the entire A2 pulley together with the adjacent C1 pulley does not clinically affect finger motion or cause tendon bowstringing, provided that the other pulleys are left intact.

Level of evidence: IV

The aim of this study was to find out how common it is to modify standard core suture configurations in flexor tendon repair and whether the use of standard core suture configurations gives a stronger repair. A total of 16 hand surgeons or residents participated in a workshop, in which they were asked to draw the suture configurations they used and to repair a porcine tendon. The properties of the repaired tendons were measured. Seven participants used a standard core suture configuration, and nine used a modified core suture. The biomechanical properties of the repairs were not affected by modifications to the core suture. However, they were affected by the number and lengths of peripheral suture bites, type of peripheral suture and the location of the core suture knot.

A total of 48 patients undergoing surgical decompression of the ulnar nerve at the cubital tunnel between February 2010 and May 2013 were retrospectively studied to determine changes in the cross-sectional area of the nerve by the technique of neurosonography. The mean follow-up was 46 months. Post-operative follow-up examination of the cross-sectional area of the ulnar nerve showed a slight reduction in the mean value from 13.8 mm² (pre-operative) to 12.9 mm² (post-operative). Of the 48 patients, 36 showed a reduction in the cross-sectional area. No correlation was detected between the clinical and sonographic outcomes. Ultrasound seems to be of limited value in the post-operative assessment of patients with entrapment neuropathy of the ulnar nerve.

Level of Evidence: IV

The aim of this study was to provide a clear description of the course, precise branching pattern and distribution of the deep branch of the ulnar nerve. A total of 36 hands from 18 preserved cadavers were dissected. The vertical distance from the pisoscaphoid line to the crossing points between the deep branch of the ulnar nerve and each metacarpal was about 4 cm. The deep branch of the ulnar nerve gave off two types of muscular branches: (1) trunks that innervate more than two intrinsic hand muscles; and (2) multiple separate branches innervating only a single muscle. The median numbers of trunks and separate branches were 5 and 6, respectively.

Levels of Evidence: N/A

We investigated the cutaneous innervation of the distal palm, an area frequently dissected by the hand surgeon. Ten (five paired) fresh-frozen cadaveric hands were dissected under 3.0× loupe magnification. Volar branches were found on both sides in the majority of digits. They originated alongside, or at the proximal margin of, the A1 pulley in 84% of digits. The mean distance from the palmar digital crease to the origin of volar branches was 21 mm.

We assessed the proximity of neurological structures to arthroscopic portals in a cadaveric study and through a systematic review. Arthroscopy was performed on ten cadaveric wrists. Subsequently the specimens were dissected to isolate the superficial branch of the radial nerve, the dorsal branch of the ulnar nerve, the posterior interosseous nerve and the extensor tendons. We measured the distances from the nerves to common portals. For the systematic review Pubmed and EMBASE were searched on the 31 May 2014 for cadaveric studies reporting the proximity of neurological structures to any arthroscopic wrist portal. In the cadaveric study, partial injuries were seen to six extensor tendons and one posterior interosseous nerve; it was assumed this was due to creation of the portals. Seven published studies were included in the systematic review. The dorsal sensory branch of the ulnar nerve was found to be at risk by performing the 6 Ulnar, 6 Radial and ulnar midcarpal portals, the sensory branch of the radial nerve by the 1–2 and 3–4 portals and the posterior interosseous nerve by the 3–4 and 4–5 portals.

Level of evidence: V

We compared the risk with the subcutaneous nerves with the anterior (Wagner) and snuff-box approaches to the trapezium in cadavers. Branches that crossed tattooed incision markings or lay within 1 cm of the markings were identified on six matched pairs of fresh-frozen cadaveric hands. Their distance from the proximal end of the incision was recorded. For anterior incisions, there were 20 vulnerable branches in total, at a mean distance of 22 mm from the proximal end of the incision. A total of 13 lay in the distal half of the incision. For snuff-box incisions, there were 18 vulnerable branches in total, at a mean distance of 11 mm from the proximal end of the incision, with 17 of them lying in the proximal half of the incision. Neither incision is without risk to nerve braches, but our study suggests a lesser risk of subcutaneous nerve damage with the snuff-box approach and highlights the greater risk in the proximal half of this incision.

Transfer of the contralateral C7 nerve for reconstruction of the brachial plexus in infants with obstetrical brachial plexus injury has rarely been reported. We developed a new endoscopy-assisted technique via the prevertebral (retroesophageal) route for the transfer of the contralateral C7 nerve in reconstruction of the brachial plexus. The reconstruction was performed in 20 infants (14 boys and six girls). Motor recovery was assessed using the Gilbert and Raimondi scales. The Narakas Sensory Grading System was used to evaluate hand sensation. The mean follow-up period was 45 months (SD 18.2). Of the 20 children, nine had contralateral C7 transfer to lower nerve roots, two had transfer to upper nerve roots and nine had transfer to both upper and lower roots. The postoperative shoulder and elbow functions were good or satisfactory according to the Gilbert classification in all children whose preoperative scores were poor. All patients with lower roots reconstruction (9) had satisfactory hand function. A total of 15 children had a Narakas score of S3. Our technique enables safe contralateral C7 transfer to the avulsed roots in severe obstetrical brachial plexus injury infants with a satisfactory functional recovery.

Level of evidence: Level IV

The purpose of this study was to examine the results of spinal accessory nerve to suprascapular nerve (with or without axillary nerve neurotization) and an Oberlin transfer as primary treatment in children with Narakas type I obstetric brachial plexus injuries, when parents refused to consent to conventional nerve trunk-/root-level reconstruction. A total of 20 children with poor shoulder abduction and no biceps antigravity function but with good hand function were treated with spinal accessory nerve to suprascapular nerve and an Oberlin transfer at a mean age of 5.8 months (SD 3.27; range 3–12.) All the patients were evaluated at a mean of 2.8 years (SD 0.8; range 1.5 to 3.8) post-operatively. Three patients were lost to follow-up. Of the remainder, 11 had grade 4+ power of elbow flexion and six patients had grade 4 power at 1 year follow-up; all had 4+ power of elbow flexion at final follow-up. At final follow-up the Mallet score was a mean of 15; (SD 4.22, range 9 to 20). Primary distal nerve transfers can give good outcomes in patients with obstetric brachial plexus injuries and may be an alternative to surgery on the nerve trunks

Level of evidence: IV