Pseudarthrosis repair. Autogenous iliac crest versus femoral ring allograft

Pseudarthrosis repair in the lumbar spine is one of the most challenging problems faced by spine surgeons. Historically high failure rates with posterior repair have led to the use of anterior lumbar interbody fusion with tricortical iliac crest autograft in these difficult cases. More recently, femoral ring allografts packed with autograft bone have been advocated as another method that would decrease donor site morbidity. Two series of patients underwent anterior lumbar interbody fusion with anterior instrumentation to repair pseudarthrosis (Group I, 33 patients with tricortical autogenous iliac crest and Group II, 20 patients with femoral ring allografts). At minimum 2-year followup, there was no difference in fusion rates (Group I, 32 of 33 versus Group II, 20 of 20). Patients in Group I had radiographic fusion develop more rapidly than patients in Group II (12 months versus 18 months), but a significant proportion of patients in Group I (35%) had an average of 2 mm of graft subsidence. Despite excellent fusion rates in both groups, functional outcomes were not as good with only 28% of patients in Group I and 36% of patients in Group II returning to work. Using anterior instrumentation, anterior interbody fusion offers an excellent method to repair pseudarthrosis using femoral ring allografts or autogenous iliac crest. However, femoral ring allografts offer the potential to decrease donor site morbidity, allowing the surgeon to treat multiple spine levels.