This retrospective study reviews three techniques of cast immobilization for the treatment of extra-articular metacarpal fractures. Group 1 was immobilized with the MCP joints in flexion and the IP joints free. Group 2 was immobilized with the MCP joints in extension and the IP joints free. Group 3 was immobilized with the MCP joints in flexion and the IP joints in full extension. All patients were immobilized for 5 weeks and evaluated at 5 weeks and 9 weeks after the initiation of treatment. Patients were compared and essentially randomized based on which of three physicians treated them since the physicians each preferred one particular treatment. Each patient underwent a hematoma block, finger trap traction and casting. 253 patients were identified for the study over a 4-year period. Their average age was 30 years (range, 18-54 years). Overall, there were no statistically significant differences between the groups with respect to motion, strength, maintenance of alignment, and fracture pattern. The average increase in angulation was 3 + 6 degrees in Group 1, 2 + 6 degrees in Group 2, and 1 + 3 degrees in Group 3. At the time of cast removal at 5 weeks post-fracture, 89% in Group 1, 80% in Group 2 and 82% in Group 3 had immediate full range of motion.
This study reported remarkably good range of motion immediately upon removing the cast despite 5 weeks of continuous immobilization. This most likely relates to the relatively young age of the patient population and may not be generalized to the elderly population. However, even in this age group, at 9 weeks, there were 4 patients that did not regain full motion and were randomly distributed across the three groups. Unfortunately, the authors did not characterize the severity of the fractures or their angulatory deformity prior to reduction nor did they report the indications or number of patients treated with pinning. Future studies would be necessary to evaluate the position of immobilization in populations most at risk for developing stiffness, i.e. the elderly and arthritic patients. However, at least in the most common group of patients that sustain metacarpal fractures, that is the young male, the position of immobilization appears inconsequential to the short term outcome.
The Journal of Bone and Joint Surgery