author = {Qin, Di. and Ma, Wen-hui. and Bai, Wei-xia. and Shang, Yong-wei. and Li, Hui-jie. and Han, Yong-tai.}, title = {{Predicting necrotic femoral head collapse using computed tomographic and X-ray imaging before hip arthroplasty: study protocol and results of a single-center, open-label, diagnostic trial}}, journal ={Clinical Trials in Orthopedic Disorders}, volume ={2}, number ={4}, pages = {125-131}, doi = {10.4103/2542-4157.219373}, year = {2017}, abstract ={Background and objectives: Determining whether the femoral head collapses and the degree of collapse of the articular cartilage of the femoral head can help select the best surgical treatment plan for patients with osteonecrosis of the femoral head. Currently, articular cartilage collapse > 2 mm or < 2 mm supports palliative surgery and hip arthroplasty, respectively. However, the ideal method to preoperatively predict femoral head collapse remains controversial. We hypothesized that computed tomography (CT) and X-ray imaging can effectively predict collapse of the necrotic femoral head before hip arthroplasty. Our preoperative measurements highly matched measurements of the intraoperatively-resected femoral head specimens. Design: A single-center, open-label, diagnostic trial. Methods: We proposed, and subsequently conducted, a single-center, open-label, diagnostic trial at the Third Hospital, Hebei Medical University, China. Eighty-six patients with unilateral osteonecrosis of the femoral head who underwent total hip arthroplasty were randomized into three groups. In the X-ray group, changes in femoral head height were measured on anteroposterior X-ray images of the pelvis (healthy and affected sides of the hip) at preoperative week 1. In the CT group, changes in femoral head height were measured using bilateral hip CT scans (healthy side and affected side) at preoperative week 1. In the specimen group, the femoral head on the affected side was resected surgically and measured directly with a ruler and vernier caliper. The primary outcome of the trial was the sensitivity of the three methods to detect femoral head collapse. The secondary outcomes were specificity, positive predictive value, negative predictive value, positive likelihood ratio, negative likelihood ratio, and diagnostic accuracy of the three methods to detect femoral head collapse; the consistency of X-ray and CT scans to diagnosis femoral head collapse; changes in the height of the middle, medial, and lateral femoral head measured by the three methods; and morphological changes in the femoral head observed by the three methods. Results: Changes in the height of the femoral head detected by different methods: The heights of the middle, medial and lateral femoral head were not significantly different on the affected side (P > 0.05). Discussion: This trial analyzed femoral head height using X-ray, CT, ruler and vernier caliper to precisely predict collapse of the necrotic femoral head, and provides imaging guidance for clinicians to select the best surgical management for osteonecrosis of the femoral head. Trial registration: ClinicalTrials.gov identifier: NCT03351153.}, URL ={https://www.clinicalto.com/article.asp?issn=2542-4157;year=2017;volume=2;issue=4;spage=125;epage=131;aulast=Qin;t=6}, eprint ={https://www.clinicalto.com/article.asp?issn=2542-4157;year=2017;volume=2;issue=4;spage=125;epage=131;aulast=Qin;t=6} }