Abstract
Introduction: The Resurfacing Hip System offers an attractive option for the treatment of arthritis in the young and active patients with gratifying outcome. Currently available Metal-on-Metal Resurfacing Hip Systems in the UK include Cormet 2000 (Corin Medical), the Birmingham Hip (Midland Medical Technologies) and Conserve Plus (Wright Cremascoli) (5). The Cormet 2000 implant design utilises the hybrid principle with an uncemented acetabular and a cemented femoral component. Achieving full seating of the acetabular component in shallow or anatomically deficient sockets can sometimes be technically difficult. On occasion, structural tricortical autografts or allografts are required to obtain a satisfactory positioning of the acetabular component. We describe a simple technique to aid fixation of the uncemented acetabular component in patients with shallow or deficient sockets.
Technical tip: The Cormet acetabular cup is equatorially expanded, resulting in improved stress distribution to the acetabulum. The acetabular component is available as pegless and pegged cup. Both Cormet cups, there are two sets of anti-rotation splines. The original Cormet cup design incorporated two sets of three anti-rotation splines; two long splines with one small spline above. These two sets of fins engage the ischium and pubis snugly. The cup is then firmly impacted in place using the cup introducer.
In shallow or deficient sockets, we describe a simple technique by 180° rotation of the Cormet 2000 metal-on-metal resurfacing pegged acetabular prosthesis. This works by utilising ischio-pubic splines for superolateral socket engagement. We have used this technique in three patients with successful outcome avoiding the need of structural graft augmentation. In one patient, this technique was supplemented with cadaveric allograft.
Conclusion: Rotating the acetabular component 180° in shallow or deficient sockets should be considered as one of the viable option with or without structural augmentation. This works satisfactorily by utilising the ischio-pubic splines for superolateral socket engagement.
The abstracts were prepared by Mr Peter Kay, Editorial Secretary. Correspondence should be addressed to British Hip Society, The Hip Centre, Wrightington Hospital, Appley Bridge, Wigan, Lancashire WN6 9EP.
