Use of relative motion orthosis in zone 3-7 extensor mechanism injuries

The study was planned to examine the effect of relative motion orthosis on range of motion and hand function in zone 3-7 extensor mechanism injuries. Inclusion criteria for individuals with zone 4-7 injury were having zone 4-7 extensor mechanism injury, being between 16-75 years old and to volunteer to participate in the study. Inclusion criteria for individuals with zone 3 extensor tendon injury were being between 16-75 years old, having diagnosed with a chronic boutonniere deformity (≥4 weeks), being in the 1st stage according to the Burton boutonniere deformity classification, completing 0° PIP joint extension with the pencil test and to volunteer to participate in the study. Total active movement (TAM) was calculated by measuring range of motion, and the Michigan Hand Outcome Questionnaire (MHQ) was used for hand functionality. Relative motion orthosis was applied in the first therapy sessions of the individuals. Early active movement approach has been applied in the treatment of individuals with zone 4-7 extensor mechanism injury. Individuals with zone 3 extensor tendon injuries were followed with only orthosis. There were differences between the 4th and 8th week TAM results (p=0.001, r=0.8) and MESA results (p=0.001, r=0.8) of 15 individuals with zone 4-7 extensor mechanism injuries. The mean duration of orthosis use in 28 individuals with zone 3 extensor tendon injury was 11.6 ± 7.8 weeks. Pre-treatment and post-treatment DIP joint flexion (p<0.001, r=0.7) and PIP joint extension limitation (p<0.001, r=0.9) degrees and MESA total score (p<0.001, r=0.8) were different. There was no relationship between the duration of orthosis use and the PIP joint extension limitation change before and after the treatment (p>0.05). In individuals with zone 4-7 extensor mechanism injury, the use of relative motion extension orthosis has provided positive improvements in early active motion and hand functionality. In individuals with zone 3 extensor tendon injuries, the use of relative motion flexion orthosis has contributed to the recovery of boutonniere deformity.