Recognizing anterior metaphyseal femoral bone loss during uncemented total hip arthroplasty: the skylight sign.
During preparation for uncemented femoral arthroplasty, a phenomenon has been observed that indicates thinning of anterior metaphyseal bone to a critical level. Light can be seen from within the canal passing through the anterior cortex. This skylight sign alerts the surgeon that a cortical defect or fracture can occur on reaming, broaching, or component insertion. In 420 consecutive arthroplasties, a skylight sign was noted in 97 (23%) hips. In 5 of those hips an oval cortical defect was created and in 3 hips a fracture occurred during broaching or insertion. Loosening developed in 1 hip with fracture. No fractures or defects occurred in hips without a skylight sign. If a skylight sign is present, the femur is at risk and preventive measures should be taken.
Harwin
Steven F
SF
Department of Orthopedic Surgery, Beth Israel Medical Center and Albert Einstein College of Medicine, New York, NY, USA.
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D001862:Bone Resorption / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D002484:Cementation; D005260:Female; D005264:Femoral Fractures / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology*; D005269:Femur / Q000000981:diagnostic imaging / Q000293:injuries / Q000473:pathology*; D006801:Humans; D007431:Intraoperative Complications / Q000209:etiology / Q000473:pathology* / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography; D012086:Reoperation