Biomechanical evaluation of the wrist after scaphotrapeziotrapezoid arthrodesis

The main objective of the present study was to present the biomechanical properties of the wrist in patients who underwent scaphotrapeziotrapezoid arthrodesis when compared to a healthy control hand.

The study group consisted of 29 consecutive patients who underwent a scaphotrapeziotrapezoid wrist arthrodesis at least 1 year before the research onset. Both hands of all patients were examined in 4 main categories.

Average score obtained in the VAS, before the surgery, without motion of the wrist was 5.21 (SD = 3.04), whereas with wrist motion, it was 8.10 (SD = 1.37). Nineteen (65.52%) patients exhibited weakened wrist muscle strength. After the surgery, only 5 (17.24%) patients declared pain in the wrist. Furthermore, the results obtained in the VAS statistically significant differed from the ones before (p < 0.05). Twenty-eight (96.55%) patients were able to resume their profession. Twenty-seven (93.10%) patients stated that they would opt for the operation again. The peak torque during the analysis of extension of the wrist in the isometric protocol was found to be 8.1 Nm (SD = 2.9), 7.9 Nm (SD = 2.3), and 7.9 Nm (SD = 2.5) in the operated hands and 10.9 Nm (SD = 3.2), 9.6 Nm (SD = 2.9), and 9.1 Nm (SD = 3.8) in non-operated hand for 30° extension, no-flexion, and 30° flexion positions, respectively (p < 0.05).

The current study is the first to present the biomechanical parameters of flexor and extensor muscles of the wrist and fingers in patients after the said procedure. Biomechanical assessments with additional isometric, isotonic, and isokinetic tests provide an opportunity to objectify treatment outcomes and guide appropriate rehabilitation by monitoring its effects.

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