Blood perfusion and bone formation before and after minimally invasive periacetabular osteotomy analysed by Positron Emission Tomography combined with Computed Tomography

Sufficient blood perfusion is essential for successful bone healing after periacetabular osteotomy (PAO). The purpose of this study was to quantify blood perfusion and bone formation before and after PAO analysed by positron emission tomography (PET) combined with computed tomography (CT). Twelve dysplastic patients (nine women) were included consecutively in the study and all were operated upon by the senior author (KS). Median age was 33 (23-55) years. Initially, two patients were PET scanned in a pilot study to test our models for calculation of the physiological parameters. The following ten patients had their hip joints PET/CT scanned immediately before PAO and three to four weeks after. Oxygen-15-water was used to quantify blood perfusion and Flourine-18-fluoride was used to produce quantitative images interpreted as new bone formation in the acetabular fragment. The blood perfusion of the operated acetabulum before surgery was 0.07 +/- 0.02 ml/min/ml, and after surgery 0.19 +/- 0.03 ml/min/ml (p = 0.0003). Blood perfusion of the non-operated acetabulum was 0.07 +/- 0.02 ml/min/ml before PAO and 0.07 +/- 0.02 ml/min/ml after surgery (p = 0.47). The fluoride-clearance per volume bone of the operated acetabulum was 0.02 +/- 0.01 ml/min/ml preoperatively, and 0.06 +/- 0.01 ml/min/ml postoperatively (p = 0.0005). Fluoride-clearance of the non-operated acetabulum was 0.01 +/- 0.01 ml/min/ml before PAO and 0.02 +/- 0.01 ml/min/ml after PAO (p = 0.49). Blood perfusion and new bone formation increased significantly in the acetabular fragment. Thus, the results of this study do not support the concern about surgically damaged vascularity after PAO.