An Initial Study into the Role of Teriparatide in Absent or Delayed Regenerate Formation during Distraction Osteogenesis: A Case Series

Purpose: Distraction osteogenesis has been used for post-traumatic segmental bone defects. Absent or delayed callus formation in the distraction gap can lead to significant morbidity and affect the clinical outcome. Experimental evidence in animal models has demonstrated that teriparatide enhances the consolidation of regenerate and also strengthens it. This study aimed to report our experience with recombinant teriparatide therapy for patients with regenerate insufficiency.Materials and methods: Nine out of 43 patients undergoing limb lengthening using the limb reconstruction system (LRS) fixator were diagnosed with regenerate insufficiency. With informed consent, these patients received a therapeutic regime of 20 mu g of teriparatide administered subcutaneously once daily for a period of 3 months.Results: The mean age in the sample was 40.22 years (SD 17.87). Regenerate insufficiency was diagnosed at a mean of 4.94 months (range 2.5-9 months) from surgery. Teriparatide injections were started at a mean of 6.94 months (range 4.5-11 months) from surgery. The sites of regenerate insufficiency were tibia (n = 5) and femur (n = 4). Favourable radiographic progress in visibility of callus was seen at a mean duration of 9.4 weeks (range 8-12 weeks) from the initiation of teriparatide therapy. No systemic complications were encountered.Conclusion: The initiation of teriparatide treatment as described in this study may be successful in triggering the osteogenic potential within poor regenerate and help in consolidation and avoid more invasive surgical procedures.