Distraction correction of chronic flexion contractures of PIP joint: comparison between two distraction rates.

PURPOSE: The surgical correction of chronic flexion contractures of the proximal interphalangeal (PIP) joints is quite challenging because the extensive soft-tissue surgery needed is demanding, and the results often are discouraging. Gradual joint distraction recently was shown to be effective in the correction of PIP joint contractures. We performed this study to determine the optimum rate and amount of daily distraction and the optimum duration for which the external fixator should be left in situ after correction. This study compared 2 groups of patients with different distraction rates: one group with 0.5 mm/day and the other group with 1.0 mm/day. We also compared and evaluated the results of external fixation removal at 1 week versus 2 weeks after full correction.

METHODS: The Mini-Orthofix external fixator was used to correct post-traumatic PIP joint contractures in 10 consecutive patients divided into 2 groups. Group 1 consisted of 5 patients who had 0.5 mm of joint distraction per day until full correction followed by an in situ external fixator for 2 weeks. Group 2 consisted of 5 patients who had 1 mm of joint distraction per day until full correction followed by an in situ external fixator for only 1 week. The 2 groups were compared and statistically analyzed.

RESULTS: At the 1-year follow-up evaluation there were no statistically significant differences between the 2 groups. The mean range of motion gained was 64 degrees in group 1 and 66 degrees in group 2. There were no recurrences.

CONCLUSIONS: We concluded that 1 mm of joint distraction per day followed by an in situ external fixator for 1 week may be safe and effective for the correction of chronic post-traumatic contractures of the PIP joint; however, similar studies on a larger group may be necessary before this technique could be recommended universally.

TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic I.