Comparison Between Supercharged Ulnar Nerve Repair by Anterior Interosseous Nerve Transfer and Isolated Ulnar Nerve Repair in Proximal Ulnar Nerve Injuries.

PURPOSE: To compare combined ulnar nerve repair with supercharged end-to-side anterior interosseous nerve to ulnar motor nerve transfer (UR+SETS) with conventional isolated ulnar repair techniques in proximal ulnar nerve transection, with respect to intrinsic muscle power recovery and claw hand deformity correction. METHODS: We conducted a comparative matched-paired series prospectively on 21 patients with proximal ulnar nerve transection injury. Eleven patients were managed by UR+SETS and 10 by isolated ulnar repair. The outcome was reported at 3, 6, 12, and 18 months using the score of Birch and Raji and Brand's criteria. RESULTS: A total of 21 patients with acute proximal ulnar nerve transection injury had completed 18 months' follow-up. We observed better results in the UR+SETS group regarding the return of intrinsic function and reduction of deformity with earlier improvement in the score of Birch and Raji and Brand's criteria. CONCLUSIONS: In the short term, UR+SETS transfer appears to result in better intrinsic muscle reinnervation and clawing deformity correction after proximal ulnar nerve transection injury. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic II.

Predictive value of metacarpophalangeal stabilization tests for simulated ulnar nerve lesion measured by a sensor glove.

STUDY DESIGN: A within-subject research design was used in this study. The difference of the range of motion (ROM) with and without ulnar nerve block was analyzed. INTRODUCTION: For the clinical evaluation of the functional effects of ulnar nerve palsy at the hand the relevance of clinical tests is in discussion. PURPOSE OF THE STUDY: The aim of the study was to evaluate the predictive value of 2 clinical tests for a simulated ulnar nerve lesion by motion analysis with a sensor glove. METHODS: In 28 healthy subjects, dynamic measurements of the finger joints were performed by a sensor glove with and without ulnar nerve block at the wrist. In the 0° metacarpophalangeal (MCP) stabilization test, the subjects were asked to stabilize the MCP joints actively in 0° while moving the interphalangeal joints, whereas at the 90° MCP stabilization test, the subjects stabilized the MCP joints actively in the 90° position. RESULTS: In the 0° MCP stabilization test, no remarkable changes of the ROM were found at the MCP joints; at the proximal interphalangeal joints 2-5, the ROM decreased with ulnar nerve block, significantly at the index, middle, and ring fingers (P < .05). In the 90° MCP stabilization test, the average ROM of the MCP joints 2-5 significantly increased with ulnar nerve block (P < .05), whereas at the PIP joints, the average ROM decreased (P < .05). DISCUSSION: The 90° MCP stabilization test had a high predictive value for the discrimination between healthy subjects and subjects with a simulated peripheral ulnar nerve lesion. CONCLUSIONS: The results could be relevant for the determination of the functional effect of ulnar nerve palsy and the quantification of clawing in hand rehabilitation. LEVEL OF EVIDENCE: II.

Quantification of hand function by power grip and pinch strength force measurements in ulnar nerve lesion simulated by ulnar nerve block.

INTRODUCTION: In the assessment of hand and upper limb function, grip strength is of the major importance. The measurement by dynamometers has been established. PURPOSE OF THE STUDY: In this study, the effect of a simulated ulnar nerve lesion on different grip force measurements was evaluated. METHODS: In 25 healthy volunteers, grip force measurement was done by the JAMAR dynamometer (Fabrication Enterprises Inc, Irvington, NY) for power grip and by a pinch strength dynamometer for tip pinch strength, tripod grip, and key pinch strength. STUDY DESIGN: A within-subject research design was used in this prospective study. Each subject served as the control by preinjection measurements of grip and pinch strength. Subsequent measurements after ulnar nerve block were used to examine within-subject change. RESULTS: In power grip, there was a significant reduction of maximum grip force of 26.9% with ulnar nerve block compared with grip force without block (P < .0001). Larger reductions in pinch strength were observed with block: 57.5% in tip pinch strength (P < .0001), 61.0% in tripod grip (P < .0001), and 58.3% in key pinch strength (P < .0001). DISCUSSION: The effect of the distal ulnar nerve block on grip and pinch force could be confirmed. However, the assessment of other dimensions of hand strength as tip pinch, tripod pinch and key pinch had more relevance in demonstrating hand strength changes resulting from an distal ulnar nerve lesion. CONCLUSIONS: The measurement of tip pinch, tripod grip and key pinch can improve the follow-up in hand rehabilitation. LEVEL OF EVIDENCE: II.

Clinical Features of Ulnar Tunnel Syndrome and the Diagnostic Value of Nerve Conduction Measurements.

OBJECTIVES: The purposes of this study were to assess the clinical features of ulnar tunnel syndrome (UTS) and to investigate the diagnostic value of nerve conduction measurements for UTS. METHODS: Eighteen patients with UTS were reviewed retrospectively. Fifteen patients had intrinsic muscle atrophy and motor weakness, and 15 had numbness with hypesthesia. The compound muscle action potentials (CMAPs) from the first dorsal interosseous (FDI) muscle and the abductor digiti minimi (ADM) muscle and the sensory nerve action potential (SNAP) from the little finger were recorded and analyzed. All patients underwent ulnar tunnel release surgery and neurolysis. Static two-point discrimination test results and pinch strengths were assessed before and after surgery. RESULTS: Before surgery, FDI-CMAP was recorded in 17 patients, and ADM-CMAP in 16, and all showed delayed latency and/or low amplitude. SNAP was recorded in eight patients and two showed delayed latency. The causes of ulnar nerve lesions were ganglion in five patients, traumatic adhesion in four, ulnar artery aberrancy in four, pisohamate arch in three, anomalous muscle in one, and ulnar vein varix in one. The sites of the lesions were in zone 1 of the ulnar tunnel anatomy in 12 patients, in zone 2 in 2, and in zones 1 and 2 in 4. After surgery, all patients obtained recovery of motor function and sensation; however, postoperative FDI-CMAP and ADM-CMAP did not improve to the normal range. CONCLUSIONS: The causes of UTS were ganglion, traumatic adhesion, ulnar artery aberrancy, and pisohamate arch. Both FDI-CMAP and ADM-CMAP were valuable for electrophysiological diagnosis of UTS.

Jammed ulnar nerve after distal radius fracture: A case report.

BACKGROUND: Ulnar nerve lesions represent a rare complication of wrist fracture. The present manuscript describes the case of a particular traumatic mechanism in which the nerve resulted crushed between radial fracture fragments. CASE PRESENTATION: A 47-year-old man suffered a subtotal lesion of the ulnar nerve following an open displaced distal radius fracture. Symptoms of ulnar nerve deficiency worsened after reduction and temporary stabilization. Further surgery was performed to achieve definitive stabilization and ulnar nerve neurolysis. The ulnar nerve was found to be jammed inside the fracture side, and so was repaired with a direct suture. Progressive recovery was observed in the following months. CONCLUSIONS: Given the paucity of reports of ulnar nerve injury in the literature, clear recommendations for treatment of nerve lesions after wrist fractures have not yet been defined. Nevertheless, in our experience, peripheral nerve function should be assessed before and after fracture reduction, as a worsening of symptoms after surgical intervention could indicate nerve entrapment inside the fracture site.

Posterior interosseous nerve to the superficial branch of the ulnar nerve transfer at the distal third of the forearm through a single anterior approach: Anatomical feasibility study.

The purpose of this study was to determine in a cadaver model, whether transfer of the posterior interosseous nerve (PIN) to the superficial branch of the ulnar nerve (SBUN) by a single approach was feasible. The experiment was carried out on five fresh cadavers. The ulnar nerve was split into its motor branches and the SBUN. The PIN was collected behind the interosseous membrane and sutured to the SBUN on its anterior surface. All sutures were tensionless and technically possible with the PIN's diameter being at least 50% of the SBUN's diameter in all cases. Our results demonstrate that PIN to SBUN transfer through a single anterior approach is feasible in a cadaver model.