Abstract
Purpose: Loosening and wear of the polyethylene insert remains an important problem after ten years. The Harris-Galante 1 (HGP1) press fit titanium backed cup appears to provide an interesting alternative. We studied the clinical and radiological outcome of 191 total hip arthroplasties performed between June 1985 and June 1990.
Material and methods: This prospective continuous series included 174 patients (191 hips), 76 women and 98 men, mean age 62.1 years (19–83). The posterior approach was used in all cases for treatment of degenerative hip disease (80%) or osteonecrosis (14.6%). The polyethylene-metal cup was used with a 28mm head in 90.7% of the cases. The press-fit cup was fixed with three screws. At review, 39 patients had died (45 hips), 25 were contacted for a phone interview, and two were lost to follow-up; 119 patients were re-examined and had a standard radiography series at last follow-up. Mean follow-up was 11.9 years (10–15). The Postel Merle d’Aubigné (PMA) score and the Harris hip score (HHS) were used to assess outcome. Quality of bone fixation and cup migration were studied as were lucent lines classed according to De Lee. Wear was calculated using the Livermore method and osteolysis using the Mulroy method. Actuarial survival curves were plotted using reoperation as the end-point if the polyethylene insert was changed or revision if the cup was changed for any reason. Qualitative data were compared using chi square test.
Results: There was one death on day three and three dislocations including two requiring reoperation for an insert overhang. The PMA pain score improved from 2.58 to 5.5 and the overall PMA score from 10.5 to 16.2. the HHS improved from 53.5 to 87.2 points. A lucent line measuring < 1 mm was found in 12 cases; one was complete, nine were in a single zone. Osteolysis was found in 28 cases and was qualified as severe in four. Mean polyethylene wear was 0.1 mm (volume 65.5 mm3). There was no case with cup migration or cup tilt and none of the cups had to be changed. Five polyethylene inserts were changed due to wear at a mean 145 months. The actuarial survival curve taking into account the seven insert changes showed a mean 15-year survival of 96.7±3%.
Discussion: The Harris-Galante press-fit cup has exhibited good behaviour at a mean 11.9 years follow-up. Mean annual wear was = 0.1 mm in 42 patients; it was > 0.2 mm in 18 patients including five who required reoperation to change the insert at 145 months. Osteolysis was noted in 28 cases, an important problem.
Conclusion: With only two patients lost to follow-up at ten years, this prospective review demonstrates well that the press-fit cup is well tolerated which has suffered from comparison with cemented cups. Five worn inserts had to be changed, requiring a simple operation. There were four cases of severe osteolysis.
The abstracts were prepared by Pr. Jean-Pierre Courpied (General Secretary). Correspondence should be addressed to him at SOFCOT, 56 rue Boissonade, 75014 Paris, France
