Reverse End-to-Side Anterior Interosseous Nerve–to–Ulnar Motor Transfer for Severe Ulnar Neuropathy

Abstract

Background: Reverse end-to-side anterior interosseous nerve transfer has been reported to enhance treatment of severe, proximal ulnar neuropathy. The authors report on patients with severe neuropathy treated with ulnar nerve transposition and distal reverse end-to-side anterior interosseous nerve transfer. Methods: Thirty patients with severe ulnar neuropathy at the elbow were reviewed. Clinical parameters included preoperative and postoperative Medical Research Council muscle strength, clawing, and degree of wasting. Electrodiagnostic data included compound motor action potential and sensory nerve action potential amplitudes. Summary statistics were used for demographic and clinical data. The t test and Wilcoxon signed rank test were used where appropriate. Results: Average follow-up was 18.6 months. Preoperatively, 20 patients had Medical Research Council less than or equal to grade 1 in hand intrinsics, small finger sensory nerve action potentials were absent in all patients except for three, and average compound motor action potentials were severely reduced (absent in nearly 40 percent) confirming severity. All groups had a statistically significant increase in strength. More than three-quarters of patients noted partial or complete resolution of clawing and intrinsic muscle wasting. Seventy-three percent of patients regained Medical Research Council greater than or equal to grade 3 and 47 percent achieved Medical Research Council greater than or equal to grade 4. Mean time to observation of nascent units was 8.5 months, and 77 percent of patients demonstrated an augmentation of motor unit numbers with forearm pronation on needle electromyography Conclusion: Proximal subcutaneous ulnar nerve transposition when combined with reverse end-to-side anterior interosseous nerve–to–ulnar nerve transfer demonstrates significant clinical and electrodiagnostic improvement of intrinsic muscle function. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Anterior Interosseous Nerve to Ulnar Nerve Transfer: A Systematic Review

“…Lesion in continuity (LIC) and pre-operative (p). Study No of Transfers Age M:F Type of Injury Location of Injury Symptom Duration pWeakness pNumbness pPain pAtrophy pPositive Froment's Sign Baltzer 13 13 35 NR 7 transection and 6 lesions in continuity 1 upper arm, 7 elbow, and 5 proximal forearm 4.4 months 13 NR NR 13 NR Chen 15 13 38.1 9:4 9 transection and 4 crush 3 upper arm, 2 elbow, and 8 proximal forearm 71.5 months NR NR NR NR NR Davidge 16 55 50.5 38:17 5 transection, 23 compression, 20 LIC, 6 motor neuropathy, and 1 neuritis 4 cervical spine, 13 brachial plexus, 3 upper arm, 20 elbow, 5 proximal forearm, 4 multilevel, and 6 diffuse neuropathy 33.6 months 55 52 29 52 45 Dengler 17 42 48 33:9 42 compression 42 elbow 31 months 42 NR NR 42 NR Doherty 18 30 53 21:9 30 compression 30 elbow NR 30 NR NR NR NR Head 22 17 56.9 11:6 2 transection, 7 compression, 7 LIC, and neuritis 1 3 upper arm, 13 elbow, and 1 forearm ...…”

“…Grip (grip strength), compared with the unaffected side (cf UAS), compared with the pre-operative ipsilateral side (cf pre-op IP), key pinch strength (key), opposition (opp), and not recorded (NR). Study Follow-up (months) Time to nerve transfer Intrinsic recovery BMRC ≥ 1 Time to recovery(months) Grip % cf UAS Grip improvement cf pre-op IP Key % cf UAS Key improvement cf pre-op IP Opp % cf UAS Claw correction Complications Baltzer 13 13.5 4.4 months 11/13 2.9 months 62% NR 52% NR 45% NR Nil Chen 15 12 2.42 months (early) NR NR 82.5% NR 83.7% (early) NR NR NR Nil Davidge 16 8 NR 36/39 1-12 months NR ↑29% NR ↑29.3% NR NR Nil Dengler 17 11.2 NR 39/42 (FDI and ADM) Variable NR ↑13.95% NR ↑28.6% NR NR Allergic reaction to Dermabond, fungal rash, haematoma, and persistent elbow pain Doherty 18 18.6 NR 29/30 8.5 months NR NR NR NR NR 24/30 3 minor complications Head 22 16.7 NR 15/17 (ADM), 16/17 (FDI) NR NR …”

“…First dorsal interosseous (FDI) and adductor digiti minimi (ADM). Study Intrinsic Recovery BMRC ≥3 (%) End-To-End Battiston 14 86 Flores 19 100 Flores 20 80 SETS Davidge 16 70 Dengler 17 79 Doherty 18 73 (FDI & ADM) Head 22 71 (FDI) & 65 (ADM) Jarvie 23 100 Koriem 24 91 Nyman 25 100 …”

The management of failed cubital tunnel decompression

“…Over three-quarters noted partial or complete resolution of clawing, 73% regained MRC grade 3 or higher, and 47% achieved at least MRC grade 4. 26 Head et al found significant improvement in intrinsic motor power in a review of 17 patients following SETS transfer; however, they identified greater recovery of the first dorsal interosseous muscle compared to the adductor digiti minimi. 45 …”

“… 25 The importance of long-term follow-up was highlighted in a recent series where improvements in intrinsic motor power after SETS transfer were seen up to 18 months after surgery. 26 …”