This study is a retrospective case series in which the authors attempt to assess the specific results of surgery on thumb deformity in children with hemiplegic cerebral palsy. The initial cohort was 56 children that all underwent appropriate proper evaluation. The follow-up cohort diminished to 33 children with adequate preoperative and postoperative evaluation to assess outcome. The outcome measurement was a validated assessment tool known as the Shriners Hospital Upper Extremity Evaluation (SHUEE). This outcome assessment assesses the spontaneous use of the involved upper extremity, static alignment of the thumb, and the dynamic thumb alignment during task performance. The biggest distinction between this outcome measure and others is the assessment of both static and dynamic thumb alignment. The mean time from surgery to follow-up analysis was slightly greater than 2 years.
A variety of surgical procedures were performed depending upon the clinical presentation. A tight web space was treated by release of the abductor pollicus and the first dorsal interosseous at their insertions. Any hyperextension of the MCP joint was treated by arthrodesis in children greater than 10 years of age, or sesamoid arthrodesis in children less 10 years of age. When thumb abduction and extension was deficient, the extensor pollicus longus was rerouted from the third to the first compartment and tensioned. The extensor pollicus longus did not have to be active to undergo rerouting.
Static thumb alignment was improved in 55% or 18 cases. No change was noted in 10 or 30%. Worsening static thumb alignment was noted in 5 cases or 15%. The positive changes in dynamic alignment were even less. In addition, the relationship between the thumb scores and spontaneous functional use of the involved extremity was poor. In other words, there appears to be no relationship between the outcome of thumb surgery and the use of the extremity.
This article highlights the difficulties in treating the spastic thumb in palm deformity. Often static alignment can be achieved but regresses during dynamic use. This retrospective series separates static and dynamic alignment, which is a valuable contribution. However, the authors were unable to provide a reproducible, effective surgical plan to improve thumb deformity in children with hemiplegic cerebral palsy.