BACKGROUND Direct anterior approach(DAA)total hip arthroplasty(THA)in a supine position provides a unique opportunity to assess leg length discrepancy(LLD)intraoperatively with fluoroscopy.Reported fluoroscopic techni...BACKGROUND Direct anterior approach(DAA)total hip arthroplasty(THA)in a supine position provides a unique opportunity to assess leg length discrepancy(LLD)intraoperatively with fluoroscopy.Reported fluoroscopic techniques are useful but are generally complicated or costly.Despite the use of multiple techniques for leg length assessment,LLD continues to be a major post-operative source of patient dissatisfaction further emphasizing the importance of near-anatomic restoration.The utility of an alternative direct measurement of LLD on an intra-operative fluoroscopic pelvic image during DAA THA has not been reported.AIM To determine the reliability of a novel simple intra-operative measurement of LLD using a parallel line technique on a single fluoroscopic digital image of the pelvis.METHODS One hundred and seventy-one patients who underwent DAA THA were included for analysis.Intra-operative fluoroscopic and post-operative anterior-posterior radiographs were imported to TraumaCad and calibrated for LLD measurement.LLD was measured on each image using the right-left hip differences in lesser trochanter to pelvic reference line distances.Pelvic reference points included the teardrops and ischia.Fluoroscopic LLD was compared to the gold-standard measurement of LLD measured on a post-operative radiograph.RESULTS Mean absolute difference in teardrop referenced LLD between fluoroscopic and post-operative radiographs was 2.17 mm and based on the ischia mean absolute difference was 2.63 mm.Linear regression of fluoroscopic and post-operative radiograph LLD based on teardrop and ischia LLD found r2 values of 0.57 and 0.84,respectively.Mean absolute difference between fluoroscopic and postoperative x-ray LLD was within 5 mm in 95%of cases regardless of pelvic reference.CONCLUSION This study demonstrates that a single fluoroscopic view obtained during DAA THA for leg length assessment is clinically useful.展开更多
文摘BACKGROUND Direct anterior approach(DAA)total hip arthroplasty(THA)in a supine position provides a unique opportunity to assess leg length discrepancy(LLD)intraoperatively with fluoroscopy.Reported fluoroscopic techniques are useful but are generally complicated or costly.Despite the use of multiple techniques for leg length assessment,LLD continues to be a major post-operative source of patient dissatisfaction further emphasizing the importance of near-anatomic restoration.The utility of an alternative direct measurement of LLD on an intra-operative fluoroscopic pelvic image during DAA THA has not been reported.AIM To determine the reliability of a novel simple intra-operative measurement of LLD using a parallel line technique on a single fluoroscopic digital image of the pelvis.METHODS One hundred and seventy-one patients who underwent DAA THA were included for analysis.Intra-operative fluoroscopic and post-operative anterior-posterior radiographs were imported to TraumaCad and calibrated for LLD measurement.LLD was measured on each image using the right-left hip differences in lesser trochanter to pelvic reference line distances.Pelvic reference points included the teardrops and ischia.Fluoroscopic LLD was compared to the gold-standard measurement of LLD measured on a post-operative radiograph.RESULTS Mean absolute difference in teardrop referenced LLD between fluoroscopic and post-operative radiographs was 2.17 mm and based on the ischia mean absolute difference was 2.63 mm.Linear regression of fluoroscopic and post-operative radiograph LLD based on teardrop and ischia LLD found r2 values of 0.57 and 0.84,respectively.Mean absolute difference between fluoroscopic and postoperative x-ray LLD was within 5 mm in 95%of cases regardless of pelvic reference.CONCLUSION This study demonstrates that a single fluoroscopic view obtained during DAA THA for leg length assessment is clinically useful.
