Histology Yields Clues to HO in Injured Service Members

Between 2000 and 2014, 1573 wounded US service members sustained one or more major amputations, and nearly two-thirds of those individuals developed posttraumatic heterotopic ossification (HO). Deciding when to excise HO (which can cause pain and interfere with rehabilitation programs and prosthetic limbs) requires careful consideration, and findings from a study by Isaacson et al. in the April 20, 2016 JBJS may help surgeons and patients faced with that decision.

Using sophisticated microscopy techniques to analyze symptomatic heterotopic bone excised from 33 service members following combat-related trauma, Isaacson et al. determined that mineral apposition rates in the HO specimens averaged 1.7 μm/day, which is 1.7 times higher than the 1.0 μm/day rate typically found in non-pathological human bone. The authors also found a direct relationship between mineral apposition rates and clinical predictors of HO, such as traumatic brain injury. The findings further suggested that mineral apposition rates correlate with the severity of HO recurrence.

Although the mineral apposition rates increased along with the time from injury to excision, the authors concluded that “the optimal time to resect symptomatic HO must still be a clinical decision,” and they call for further investigation into correlations between mineral apposition rates and HO development and recurrence.