Pelvic Ring Reconstruction with Vascularized Bone Flaps Reduces Compensatory Scoliosis after External Hemipelvectomy.

Abstract

External hemipelvectomy (EH) is a complex amputation that removes the hemipelvis and leg, most commonly performed to resect a locally advanced pelvic malignancy. This destabilizes the spinopelvic anatomy and may result in a compensatory scoliosis (CS) to maintain an upright posture. The authors hypothesized that pelvic ring reconstruction with vascularized bone (VB) will reduce CS and improve functional outcomes. The authors conducted a retrospective cohort study of patients who underwent an EH between May of 2023 and January of 2004. Patients were categorized by use of VB or not (NVB). The primary outcome was CS (Cobb angle >10 degrees on imaging >10 months postprocedure). Secondary outcomes included surgical complications and functional outcomes. The authors identified 58 reconstructions (VB, 29; NVB, 29). Median follow-up (months) for VB was 25.9 months (interquartile range, 34.6 months) and for NVB was 16.1 months (interquartile range, 114.9 months). For VB, fibula (41.4%) and tibia (37.9%) flaps were most common, including 15 pedicled and 14 free fillet flaps. Median time to full union was 8.8 months (range, 3.4 to 11 months). CS was diagnosed in 22.2% and 78.6% of VB and NVB patients, respectively ( P = 0.004). Median Cobb angle for VB was 8 degrees (range, 2 to 21 degrees) and 15.1 degrees (range, 3 to 30 degrees) for NVB ( P = 0.02). The overall complication rate was not different between the 2 groups. Similar proportions of VB and NVB patients tolerated prostheses (34.5% versus 32.1%) and were reliant on a wheelchair (65.5% versus 60.7%). Pelvic ring reconstruction with VB after EH appears to reduce the incidence and severity of CS, without increasing complication rates.