Promising Mid-term Results With a Cup-cage Construct for Large Acetabular Defects and Pelvic Discontinuity

• Published in: Clinical orthopaedics and related research 2016-02, Vol.474 (2), p.408-414
• Main Authors: Amenabar, Tomas, Rahman, Wael A., Hetaimish, Bandar M., Kuzyk, Paul R., Safir, Oleg A., Gross, Allan E.
• Format: Article
• Language: English
• Subjects: Acetabulum - diagnostic imaging; Acetabulum - physiopathology; Acetabulum - surgery; Adult; Aged; Aged, 80 and over; Arthroplasty, Replacement, Hip - adverse effects; Arthroplasty, Replacement, Hip - instrumentation; Biomechanical Phenomena; Conservative Orthopedics; Female; Foreign-Body Migration - etiology; Foreign-Body Migration - surgery; Hip; Hip Joint - diagnostic imaging; Hip Joint - physiopathology; Hip Joint - surgery; Hip Prosthesis - adverse effects; Humans; Kaplan-Meier Estimate; Male; Medicine; Medicine & Public Health; Middle Aged; Orthopedics; Prosthesis Design; Prosthesis Failure; Prosthesis-Related Infections - microbiology; Prosthesis-Related Infections - surgery; Radiography; Reoperation; Retrospective Studies; Risk Factors; Sports Medicine; Surgery; Surgical Orthopedics; Symposium: 2015 Hip Society Proceedings; Time Factors; Treatment Outcome
• ISSN: 0009-921X; 1528-1132
• DOI: 10.1007/s11999-015-4210-4

Background Restoring normal anatomy and achieving stable fixation of the acetabular component can be especially challenging when the surgeon must deal with severe acetabular defects and/or pelvic discontinuity. The cup-cage (CC) construct, where an ilioischial cage is cemented within a biologically fixed porous metal cup, has emerged as an excellent option to treat such challenges. Questions/purposes We sought to determine (1) mid-term Kaplan-Meier survival; (2) clinical outcomes based on Merle d’Aubigné-Postel scores; (3) radiological outcomes based primarily on construct migration; and (4) the complication rate for a series of 67 CC procedures performed at our institution. Methods All hip revision procedures between January 2003 and March 2012 where a CC was used (with the exception of tumor cases or acute fracture; four total cases) that had a minimum 2-year followup and that had been seen within the last 2 years were included in this retrospective review. Acetabular bone loss and presence of pelvic discontinuity were assessed according to the Gross classification. Sixty-seven CC procedures with an average followup of 74 months (range, 24–135 months; SD, 34.3) months were identified; 26 of 67 (39%) were Gross Type IV and 41 of 67 (61%) were Gross Type V (pelvic discontinuity). Postoperative clinical and radiological evaluation was done annually. Merle d’Aubigné-Postel scores were recorded and all radiographs were compared with the 6-week postoperative radiographs to evaluate for radiographic loosening or migration. Failure was defined as revision surgery for any cause, including infection. Results The 5-year Kaplan-Meier survival rate with revision for any cause representing failure was 93% (95% confidence interval [CI], 83.1–97.4), and the 10-year survival rate was 85% (95% CI, 67.2–93.8). The Merle d’Aubigné-Postel score improved significantly from a mean of 6 preoperatively to 13 postoperatively (p