Factors that affect the healing index of metacarpal lengthening: a retrospective study.

PURPOSE To determine factors that affect healing index and consolidation time following lengthening of congenitally short metacarpals (brachymetacarpia). METHODS 18 metacarpals of 8 young women (mean age, 18.6 years) were lengthened using the callus distraction technique. The results, including healing index and consolidation time, were analysed and compared with those in the literature. RESULTS The mean length increase was 16.5 mm (55% of the original length of 30 mm). Age was positively correlated with healing index and consolidation time: younger patients healed faster than older patients. Healing index differed significantly between patients aged 0 to 18 years and those aged 19 to 30 years (p=0.002). Comparison of our results with 9 previous studies confirmed that increased age was associated with a greater healing index and consolidation time. Conversely, the faster the distraction rate, the less the healing index and consolidation time. CONCLUSION Age has the most effect on healing index and consolidation time. Metacarpal lengthening using callus distraction is recommended. Adolescence is the most appropriate time to perform distraction lengthening of a congenitally short metacarpal. This will avoid additional lengthening of normal metacarpals prior to epiphyseal closure.