Ollier\'s Disease Regenerate Healing Rates: Is there Cause for Concern?

Background: Ollier's disease, characterised by multiple enchondromas, can result in significant limb length discrepancy and angular deformities.Anecdotal evidence suggests faster healing rates and a risk of premature consolidation during lengthening.The aim is to evaluate healing rates in Ollier's and assess the need for change in practice.Materials and methods: A total of 12 patients with Ollier's disease underwent limb lengthening utilising an external fixator or intramedullary lengthening nail.A latency period of 6 days was followed by a lengthening rate of 1 mm per day.Parameters, including lengthening index (LI), bone healing index (BHI), and external fixation index (EFI), were recorded.The regenerate quality was assessed using the pixel value ratio (PVR) when lengthening was achieved, at frame removal, and equivalent cortex formation following a nail.Change in lengthening rates and complications were noted.Results: Eleven males and one female underwent 20 lengthening episodes at a mean age of 14 years (8-29 years).The mean lengthening was 4.9 cm (1-10 cm).Full regeneration consolidation occurred in all patients.Following external fixation, the mean LI was 17.78 days/cm (9.5-71), the BHI was 33.62 days/cm (4-133), and the EFI was 53.60 days/cm (21.43-210).A lower, but not statistically significant, BHI of 11.23 days/cm (3.5-22.86)was recorded in the nail group.The mean PVR was 0.84 (0.53-1.2) at the end of lengthening and 0.94 (0.64-1.13) at frame removal following external fixation, compared to 0.78 (0.74-0.86) and 0.86 (0.77-0.94) with nails; again, no significant difference was noted.Complications included one case of premature consolidation during humeral lengthening requiring re-osteotomy.One case of knee flexion deformity and pain during radial lengthening required a slowing of the distraction rate.One case of tibial valgus deformity was deliberately corrected slowly to avoid traction injury to the common peroneal nerve.No other cases had a change in lengthening rate or rhythm.Discussion: All our patients undertook successful lengthening with good bone consolidation.The healing indices recorded are similar to the published literature.We accept the limitations of a retrospective study with small numbers.With only one case of premature consolidation, we have no evidence to support the concept of faster regenerate consolidation in patients undergoing lengthening in Ollier's disease.