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 weakness caused by distal median nerve lesion by dynamometry.

INTRODUCTION: In the assessment of hand and upper limb function, grip strength is of major importance. Use of the JAMAR dynamometer has been an accepted test of grip strength and routinely part of the physical examination. PURPOSE OF THE STUDY: The aim of this study was to determine by means of a median nerve block simulating a patient group if the measurement of different types of grip force can improve the quantification of impairment of the hand beyond the sole power grip measurements. METHODS: In 29 healthy volunteers, grip force measurement was done by the JAMAR dynamometer for power grip and by a pinch grip dynamometer for pincer grip, precision grip, pinch grip, and palmar abduction. At the power grip, the force of digit 2-5 was measured separately by a sensor glove. For each measurement, 3 trials were recorded subsequently. 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 median nerve block were used to examine within-subject change. RESULTS: In power grip, there was no significant reduction of maximum grip force with median nerve block compared with grip force without block. By measuring the finger forces by a sensor glove, a reduction of force at the individual fingers was found compared with the setting with no block, although significant only at the middle finger (P < .017). With median nerve block, average grip force decreased significantly 20% in pincer grip (P < .021), 29.5% in pinch grip (P < .002), 39.5% in precision grip (P < .001), and 70.7% in palmar abduction (P < .013). CONCLUSIONS: These experiments suggest a minor role of the measurement of the power grip force in the diagnostics of distal median nerve block with the dynamometer, which could not be substantially improved by the digit forces and the force distribution of the individual fingers. The assessment of other grip forms, such as pincer grasp, precision grip, pinch grip, and especially palmar abduction, leads to a relevant improvement in the diagnostics of distal median nerve lesion. 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.

[Dorsal ligamentoplasty for posttraumatic scapholunate dissociation]. / Die dorsale Bandplastik bei posttraumatischer skapholunärer Dissoziation.

Scapholunate dissociation in stages 2 and 3 may lead to posttraumatic damage if left untreated. Different types of treatment have been described, including capsulodesis, tenodesis, and others. The purpose of all procedures is to avoid palmar shift of the distal scaphoid resulting in secondary arthritis (SLAC wrist). This study aimed to evaluate a modified dorsal ligamentoplasty in second- and third-degree scapholunate dissociation in a prospective study design. Furthermore, the study aimed to find out if there is a correlation between radiological and clinical parameters at follow-up and whether or not a SLAC wrist can be avoided. From 2007 to 2011 we performed 29 dorsal ligamentoplasties in our hospital in patients with second- and third-degree scapholunate dissociation. In a prospective study design, 25 patients were followed up after an average period of 18 months. Parameters recorded preoperatively included ROM, the radiological parameters SL diastasis, SL diastasis in power grip and SL angle, the DASH score, and the VAS score. The postoperative evaluation additionally included power grip, the Mayo wrist score, and patients' subjective satisfaction. The average subjective satisfaction after surgery was good. The average postoperative ROM was 83.8 % of the ROM of the healthy wrist and decreased by 11 % compared with the preoperative level. The average postoperative grip strength was 85.7 % of the strength of the healthy hand. The VAS score was 2.7 with a significant reduction from 6.7 preoperatively. The average DASH score decreased significantly from 60 preoperatively to 22.5 postoperatively. The average Mayo wrist score after surgery was 73. All radiological parameters at follow-up were significantly better than preoperatively, although they remained in a pathological range. The Pearson correlation analysis showed no relevant correlation between clinical and radiological scores. Three cases (12 %) required revision surgery. The described modified dorsal ligamentoplasty at the carpus can be recommended in second- and third-degree scapholunate dissociation. Clinical results are comparable to other techniques, but there is only a single approach required and the complication rate is very low. The short average follow-up of 18 months must be viewed critically as the rate of SLAC wrists might be higher during longer follow-up periods.