Distraction osteogenesis (DO) is a commonly used technique in multiple orthopedic sub-specialties, including trauma, oncology and pediatrics. This technique aims to produce new bone formation in the distraction gap in a controlled manner. The issue with this technique has been the high risk of complications, one of which is poor regenerate formation during the distraction process. Although several factors (including patient and operative factors) and techniques (including surgical, mechanical and pharmacological) have been described to ensure successful regenerate formation during the process of DO, these factors are sometimes difficult to control clinically. Our aim from this review is to highlight the different factors that affect DO, modalities to assess the regenerate and review treatment options for poor regenerate in the distraction gap. In addition, we propose a management protocol derived from the available literature that can be used to facilitate the management of inadequate regenerate formation.

A decade ago our group had reported that osteotomy healing was commonly delayed in children with moderate to severe osteogenesis imperfecta (OI) who were treated with intravenous pamidronate infusions. We subsequently maintained a bisphosphonate infusion-free interval of 4 months after osteotomy and changed the surgical approach (use of an osteotome instead of a power saw). In addition, zoledronic acid has become the standard intravenous bisphosphonate for treatment of OI at our institution. In the present study, we compared osteotomy healing before and after these changes were instituted. We evaluated bone healing post-osteotomy on standard radiographs after 261 intramedullary rodding procedures involving osteotomies (139 femur, 112 tibia) in 110 patients (age at surgery 1.2 to 20.4 years). Delayed healing was diagnosed when the osteotomy line was visible 12 months after the event. We observed delayed bone healing after 48 of the 114 osteotomies (42%) performed with the new approach, and in 106 of the 147 osteotomies (72%) using the previous approach (p ¼ 0.001). The odds for delayed osteotomy healing were significantly lower with the new approach even after adjustment for age, sex, height Z-score, weight Z-score, OI type, and bone involved (odds ratio ¼ 0.17; 95% confidence interval 0.16-0.47). Thus, delayed osteotomy healing occurred less frequently in the past 10 years than in the decade before that. It is likely that this improved result is attributable to the implemented changes in both medical and surgical management.