Contractures of the upper extremities in spinal muscular atrophy type II. Descriptive clinical study with retrospective data collection.
The most significant orthopaedic problem for patients with the intermediate form of spinal muscular atrophy, SMA type II, is the appearance of contractures in addition to progressive scoliosis and pelvic obliquity with increasing loss of sitting stability. This study deals with restrictions of the passive range of motion and the development of contractures in the joints of the upper extremities in these patients. We followed up 143 patients, 74 female and 69 male, with SMA type II for an average of 5.3 years (± 4.0, 0.2 - 18.7). Their average age at the first examination was 8.4 years (± 6.6, 0.1 - 34.1) and at the last examination 12.3 years (± 6.5, 0.7 - 37.1). The passive range of joint motion was determined using a goniometer. According to Johnson et al. (1992), we calculated the relative contracture index (CI). The loss of range of motion and the contractures of the joints of the upper extremities (shoulder, elbow and wrist) increased progressively with age. The most marked restriction of motion was in the elbow joint with severe flexion contractures in some cases. The findings of this study give us more information about the development of contractures of the upper extremities and aim to help to improve the quality of orthopaedic care of patients with SMA type II.