Does crossover innervation really affect the clinical outcome? A comparison of outcome between unilateral and bilateral digital nerve repair

Digital nerve injury: to repair or not?

BACKGROUND

There are very few studies comparing patients with and without repair after digital nerve injury. It is still controversial whether digital nerve repair is necessary.

AIMS

The aim of this study was to evaluate the long-term clinical outcomes of patients with unilateral isolated digital nerve injury who underwent surgical repair and those who did not.

METHODS

Seventy-four patients with unilateral digital nerve injury were included in the study. Of these, the patients who underwent surgical repair were determined as group A (n = 42), the patients without repair as group B (n = 32), and the groups were divided into subgroups according to injury levels. Results were evaluated with a minimum follow-up of 24 months.

RESULTS

When the S2PD results were evaluated overall, it was found that those who had digital nerve repair (group A) had significantly better outcomes compared to those without repair (group B) (p = 0.012). When the subgroups were evaluated according to the injury localization, no significant difference was observed at the distal levels, while it was observed that the patients who underwent repair in the proximal levels showed significantly better results (p = 0.003, p = 0.012).

CONCLUSION

In this study, it was seen that there was no difference between the results of repair and non-repair of unilateral nerve injuries distal to the middle level of the middle phalanx, but repair is required in injuries proximal to this level.

Treatment options for digital nerve injury: a systematic review and meta-analysis

BACKGROUND

Surgical treatment of finger nerve injury is common for hand trauma. However, there are various surgical options with different functional outcomes. The aims of this study are to compare the outcomes of various finger nerve surgeries and to identify factors associated with the postsurgical outcomes via a systematic review and meta-analysis.

METHODS

The literature related to digital nerve repairs were retrieved comprehensively by searching the online databases of PubMed from January 1, 1965, to August 31, 2021. Data extraction, assessment of bias risk and the quality evaluation were then performed. Meta-analysis was performed using the postoperative static 2-point discrimination (S2PD) value, moving 2-point discrimination (M2PD) value, and Semmes-Weinstein monofilament testing (SWMF) good rate, modified Highet classification of nerve recovery good rate. Statistical analysis was performed using the R (V.3.6.3) software. The random effects model was used for the analysis. A systematic review was also performed on the other influencing factors especially the type of injury and postoperative complications of digital nerve repair.

RESULTS

Sixty-six studies with 2446 cases were included in this study. The polyglycolic acid conduit group has the best S2PD value (6.71 mm), while the neurorrhaphy group has the best M2PD value (4.91 mm). End-to-side coaptation has the highest modified Highet's scoring (98%), and autologous nerve graft has the highest SWMF (91%). Age, the size of the gap, and the type of injury were factors that may affect recovery. The type of injury has an impact on the postoperative outcome of neurorrhaphy. Complications reported in the studies were mainly neuroma, cold sensitivity, paresthesia, postoperative infection, and pain.

CONCLUSION

Our study demonstrated that the results of surgical treatment of digital nerve injury are generally satisfactory; however, no nerve repair method has absolute advantages. When choosing a surgical approach to repair finger nerve injury, we must comprehensively consider various factors, especially the gap size of the nerve defect, and postoperative complications. Type of study/level of evidence Therapeutic IV.

Outcomes of Flexor Tendon Repair in Patients With Concurrent Neurovascular Injuries of Multiple Digits in Zone 1

PURPOSE

We treated several patients with multiple flexor (flexor digitorum profundus; FDP) injuries accompanied by injuries to the digital nerve or vessels around the distal interphalangeal crease (zone 1). Here, we retrospectively report the outcomes and review the literature.

MATERIALS AND METHODS

Between January 2010 and December 2018, 16 patients who met the study inclusion criteria were investigated. Tendons were repaired using the cross-locked cruciate (Adelaide) technique (6-strand) or modified Becker method (4-strand). The neurovascular structures were repaired under a microscope.

RESULTS

Sixteen patients (47 digits) were treated. According to the criteria of Moiemen and Elliot, the lacerated areas were in zones IA and IB in 7 and 40 digits, respectively. The mean ranges of motion were 149.27 ± 7.78 and 66.43 ± 2.04 degrees according to the Strickland and modified Strickland assessments, respectively. The mean 2-point discrimination was 5.00 ± 0.63 mm. Four patients (group 1) presented with injuries to 2 digits, and 9 (group 2) and 3 (group 3) patients had 3 and 4 injured digits, respectively. The outcomes were satisfactory in terms of the mean range of motion; 2-point discrimination; cold tolerance; visual analog scale pain score; Disabilities of the Arm, Shoulder, and Hand score; and grip strength. There were no differences among the groups.

CONCLUSIONS

Open multiple-finger injuries involving flexor digitorum profundus rupture with concurrent neurovascular injuries on one or both sides occasionally occur in industrial environments. Fortunately, each digit exhibits a consistent injury type in a particular anatomical location; appropriate repair yields satisfactory outcomes despite the presence of multiple injuries.

Safety and efficacy of a nerve matrix membrane as a collagen nerve wrapping: a randomized, single-blind, multicenter clinical trial

A new nerve matrix membrane derived from decellularized porcine nerves has been shown to retain the major extracellular matrix components, and to be effective in preventing adhesion between the nerve anastomosis sites and the surrounding tissues in a rat sciatic nerve transection model, thereby enhancing regeneration of the nerve. The effectiveness of the membrane may be attributed to its various bioactive components. In this prospective, randomized, single-blind, parallel-controlled multicenter clinical trial, we compared the safety and efficacy of the new nerve matrix membrane with a previously approved bovine tendon-derived type I collagen nerve wrapping. A total of 120 patients with peripheral nerve injury were recruited from Beijing Jishuitan Hospital, The First Bethune Hospital of Jilin University, and Yantai Yuhuangding Hospital, China. The patients were randomly assigned to undergo end-to-end and tension-free neurorrhaphy with nerve matrix membrane (n = 60, 52 male, 8 female, mean age 41.34 years, experimental group) or tendon-derived collagen nerve wrapping (n = 60, 42 male, 18 female, mean age 40.17 years, control group). Patients were followed-up at 14 ± 5, 30 ± 7, 90 ± 10 and 180 ± 20 days after the operation. Safety evaluation included analyses of local and systemic reactions, related laboratory tests, and adverse reactions. Efficacy evaluation included a static 2-point discrimination test, a moving 2-point discrimination test, and a Semmes–Weinstein monofilament examination. Sensory nerve function was evaluated with the British Medical Research Council Scale and Semmes–Weinstein monofilament examination. The ratio (percentage) of patients with excellent to good results in sensory nerve recovery 180 ± 20 days after the treatment was used as the primary effectiveness index. The percentages of patients with excellent to good results in the experimental and control groups were 98.00% and 94.44%, respectively, with no significant difference between the two groups. There were no significant differences in the results of routine blood tests, liver and renal function tests, coagulation function tests, or immunoglobulin tests at 14 and 180 days postoperatively between the two groups. These findings suggest that the novel nerve matrix membrane is similar in efficacy to the commercially-available bovine-derived collagen membrane in the repair of peripheral nerve injury, and it may therefore serve as an alternative in the clinical setting. The clinical trial was approved by the Institutional Ethics Committee of Beijing Jishuitan Hospital, China (approval No. 20160902) on October 8, 2016, the Institutional Ethics Committee of the First Bethune Hospital of Jilin University, China (approval No. 160518-088) on December 14, 2016, and the Institutional Ethics Committee of Yantai Yuhuangding Hospital, China (approval No. 2016-10-01) on December 9, 2016. The clinical trial was registered with the Chinese Clinical Trial Registry (registration number: ChiCTR2000033324) on May 28, 2020.

Outcomes of surgical repair of a single digital nerve in adults

Current standard management of a cut digital nerve is end-to-end microsurgical nerve coaptation where possible. A recent systematic review of adult digital nerve injuries that were either repaired or left unrepaired showed that the evidence for good nerve recovery or improved function following nerve repair is poor. In the 30 studies included, only 24% of repaired nerves regained sensory recovery close to or equivalent to estimated pre-injury levels. Neuroma rates were the same in those nerves repaired (4.6%) and those not repaired (5%). Questions under debate include proper assessment methods of outcomes, decision making for repair or no repair to different fingers or the thumb, levels of injury, age, and hand dominance. This review summarizes the major evidence available and debates the surgical dogma that surrounds this injury.