Three-dimensional analysis of thumb motion recovery after carpal tunnel release

Difference between the thumb motions in carpal tunnel syndrome and trapeziometacarpal osteoarthritis

BACKGROUND

This study quantified thumb movement in patients with trapeziometacarpal osteoarthritis and carpal tunnel syndrome and examined the characteristics of each disorder using three-dimensional motion analysis.

METHODS

Twenty-three hands of 23 patients with trapeziometacarpal osteoarthritis, 88 hands of 73 patients with idiopathic carpal tunnel syndrome, and 29 hands of 20 healthy volunteers were included in this study; three-dimensional thumb kinematics were measured during the circumduction task using a retroreflective surface-based marker method.

FINDINGS

Trajectory of thumb tip reduced in both patient groups compared to healthy controls, with carpal tunnel syndrome exhibiting the flattening shape. Trapeziometacarpal osteoarthritis patients had decreased range of motion in all directions at the trapeziometacarpal joint, while maintaining flexion-extension at the metacarpophalangeal and interphalangeal joints. Carpal tunnel syndrome patients showed reduced motion particularly in metacarpophalangeal and interphalangeal flexion-extension. Joint contribution analysis revealed decreased trapeziometacarpal involvement and increased compensatory metacarpophalangeal and interphalangeal movements in trapeziometacarpal osteoarthritis, while carpal tunnel syndrome showed impaired metacarpophalangeal abduction.

INTERPRETATION

This study provides novel insights into the distinct kinematic characteristics of trapeziometacarpal osteoarthritis and carpal tunnel syndrome, offering potential for improved screening and assessment of thumb motor impairments in these conditions.

EVIDENCE LEVEL

Diagnostic LEVEL III.

Association between three-dimensional motion analysis of the thumb and clinical parameters in patients with carpal tunnel syndrome

We analysed the relationship between motor dysfunction of the thumb and the clinical parameters of carpal tunnel syndrome using three-dimensional motion analysis. This single-centred, prospective study included 65 hands in 51 patients with idiopathic carpal tunnel syndrome and 30 healthy hands. Three-dimensional thumb kinematics were acquired using a motion capture system with a retroreflective surface-based marker method. The trajectory area of thumb tip, adduction and abduction of the trapeziometacarpal joints and metacarpophalangeal joints were correlated with the clinical parameters. There was no significant correlation between the results of motion analysis values and patient-reported outcomes measures. Thumb movement disorder associated with carpal tunnel syndrome affected specific activities of daily living based on the pinching movements, such as 'writing' and 'buttoning clothes' among the patient-reported outcome measure items.Level of evidence: III.