The measurement of finger and wrist range of motion (ROM) is of great importance to clinicians when assessing functional outcomes of therapeutic interventions and surgical procedures. The purpose of the study was to assess the repeatability of ROM measurements of the hand joints with manual goniometer and 3D motion capture system and to calculate the minimal detectable difference for both methods. Active finger and wrist joints ROM of 20 healthy volunteers were assessed using a manual goniometer and 3D motion capture system. Minimal detectable difference (MDD) and standard error of measurement (SEM) were calculated for both measurement systems and compared within the same task. Maximal ROM of all joints was registered twice on two different days to evaluate the test-retest repeatability. The intraclass correlation coefficients (ICC) was calculated and examined to determine if reliability ≥ 0.70 existed. MDD for the 3D motion capture was between 5 and 12° except for the metacarpophalangeal joint (MCP) 1, interphalangeal joint (IP), and MCP5. SEM values lay between 2 and 4° for all joints except for the MCP5, IP, and MCP1. For the goniometric measurements, MDD and SEM were between 12–30° and 4–11°, respectively. The reliability criterion (ICC > 0.7) was achieved for the ROM measurement with the 3D motion capture system for 94% of the joints and in only 65% of the joints with the manual goniometer. Joint ROM assessed with 3D motion analysis showed higher test-retest agreement demonstrating overall better repeatability for this method. Because of the smaller measurement error, the 3D motion capture system has a smaller MDD. Only individual test-rest differences bigger than the MDD can be considered as real changes, and therefore, in an experimental situation, the use of a more precise measurement method can greatly reduce the number of subjects needed for a statistical significance. Goniometer measurements of some joints should be carefully interpreted, due to a low repeatability and reliability. This study is approved by the Ethical Committee Zurich ( Kek-ZH-Nr: 2015-0395 ).

We report outcomes in 29 patients with flexor tendon repairs in 32 digits (five thumbs and 27 fingers) with our modified protocols. We repaired the lacerated flexor digitorum profundus tendons with core suture repairs using the 6-strand M-Tang method and without circumferential sutures. We divided the pulleys as much as needed to allow excursion of the repaired tendons, including complete division of the A4 or A2 pulleys when necessary. In nine fingers, we repaired one slip of the flexor digitorum superficialis tendon and resected the other half. When the flexor digitorum profundus tendon would not glide under the A2 pulley, we excised the remaining slip of the flexor digitorum superficialis tendon. The wrist was splinted in mild extension post-surgery with early commencement of tenodesis exercises. No tendon repair ruptured. By the Strickland criteria, out of 27 fingers, 18 had excellent, six had good, two had fair, and one had poor results. We conclude that a strong core suture (such as the M-Tang repair) without peripheral sutures, and with division of pulleys as necessary is safe for early active motion and yields good outcomes. Level of evidence: IV

Results of anatomical resurfacing of the proximal interphalangeal joint using pyrocarbon implants showed reasonable clinical results with a high radiographic migration rate. The aim was to investigate the subjective, clinical, and radiographic results 10 years following surgery, and to compare them with our 2-year follow-up data. We re-evaluated 12 patients with 15 proximal interphalangeal implants on average 9.7 years after surgery. Pain significantly improved from 7.6 on a visual analogue scale pre-operatively to 1.4 at 2 years, and to 0.7 at the final follow-up. The mean total range of motion in all replaced joints was 36° pre-operatively and 39° at the 2-year follow-up, but had decreased significantly to 29° at 10 years. We saw one implant migration in addition to the eight migrated implants we already found 2 years after surgery. The moderate clinical results, combined with the high migration rate, mean that we no longer use this kind of implant.

The human hand is the most frequently used body part in activities of daily living. With its complex anatomical structure and the small size compared to the body, assessing the functional capability is highly challenging. The aim of this review was to provide a systematic overview on currently available 3D motion analysis based on skin markers for the assessment of hand function during activities of daily living. It is focused on methodology rather than results. A systematic review according to the PRISMA guidelines was performed. The systematic search yielded 1349 discrete articles. Of 147 articles included on basis of title, 123 were excluded after abstract review, and 24 were included in the full-text analysis with 13 key articles. There is still limited knowledge about hand and finger kinematics during activities of daily living. A standardization of the task is required in order to overcome the nonrepetitive nature and high variability of upper limb motion and ensure repeatability of task performance. To yield a progress in the analysis of human hand movements, an assessment of human kinematics including fingers, wrist, and thumb and an identification of relevant parameters that characterize a healthy motion pattern during functional tasks are needed.

This study aims to compare a new inertial measurement unit based system with the highly accurate but complex laboratory gold standard, an optoelectronic motion capture system. Inertial measurement units are sensors based on accelerometers, gyroscopes, and/or magnetometers. Ten healthy subjects were recorded while performing flexion-extension and radial-ulnar deviation movements of their right wrist using inertial sensors and skin markers. Maximum range of motion during these trials and mean absolute difference between the systems were calculated. A difference of 10° ± 5° for flexion-extension and 2° ± 1° for radial-ulnar deviation was found between the two systems with absolute range of motion values of 126° and 50° in the respective axes. A Wilcoxon rank sum test resulted in a no statistical differences between the systems with p-values of 0.24 and 0.62. The observed results are even more precise than reports from previous studies, where differences between 14° and 27° for flexion-extension and differences between 6° and 17° for radial-ulnar deviation were found. Effortless and fast applicability, good precision, and low inter-observer variability make inertial measurement unit based systems applicable to clinical settings.

We report sonographic findings with clinical outcomes after zone 2 flexor digitorum profundus tendon repairs in ten fingers. The tendons underwent a six-strand M-Tang core repair, no circumferential suture, and partial or complete division of the pulleys. Over 12 months after surgery and using ultrasound, we found no gapping at the repair site during finger motion. When the pulleys were divided, there was sonographic evidence of tendon bowstringing, but the bowstringing was minimal. Clinically, we did not find any fingers that displayed tendon bowstringing or had functional loss. With ultrasound examination, the repaired tendons remained enlarged over 12 months. Two patients developed heterotopic ossifications at the repair site without tendon gliding, and these required tenolysis. We conclude that the tendon repair site does not gap when a strong core suture is used in the repair without adding peripheral sutures. There is no notable tendon bowstringing clinically, though the repaired tendons have sonographic evidence of minor bowstringing. Level of evidence: III