The purpose of the present study was to analyze the-clinical and radiographic factors which determine the enduring fixation of metal on metal hybrid surface arthroplasty.

The first 500 hips (in 436 patients) of a consecutive series of over 700 Conserve® plus were reviewed clinically and radiographically. The patients were 48.6 years-old in average, 74% were male and the dominant etiology was idiopathic osteoarthritis (64.6%). All femoral components were cemented but the femoral metaphyseal stem was cemented in 112 hips and press-fit in the remaining 388.

Average follow-up was 4.8 years (range, 2.7 to 7.8 years). Eighteen hips were converted to a THR, 11 of them for aseptic loosening of the femoral component at an average follow-up of 40.5 months. Put in positives mention fx and loose incidence, survor ship details of loose and fx for other At last review, 14 hips presented metaphyseal stem radiolucencies and 16 hips (3.2%) showed a narrowing of the neck of 10% or more at the interface with the femoral component. None of the components with cemented stems showed femoral radiolucencies, neck narrowing, or were revised for aseptic loosening. Cementing the femoral stem significantly (p = 0.013) reduces the chances of early femoral failure or appearance of a metaphyseal stem radiolucency.

Risk factors for loosening or radioluciences included cysts > 1 cm, small femoral head size, female gender, early cases (before improved acrylic fixation including femoral suctioning measures were instituted) and reduced stem shaft angle. Metal-on-metal surface arthroplasty provides a stable, bone conserving, low morbidity and wear resistant prosthetic solution well suited for young and highly active patients.

Aims: Review short to medium term results of a metal-on-metal (M/M) hybrid surface arthroplasty (SA) for a young and active patient population. Methods: The þrst 400 hips (of 533) in 355 patients underwent M/M hybrid surface arthroplasty. Mean age 48.2; 73% males, 27% females; 198 Charnley Class A; 139 Class B and 18 Class C. Diagnosis at surgery: OA 64%, DDH 11%, ON 9%, Post-traumatic 8%, Inßammatory arthritis 3%, SCFE and LCP 4%, Melorheostosis 0.3%. Results: Mean follow-up 3.9 years (2.6–6.5). Average UCLA hip scores post-op: pain 9.4, walking 9.5, function 9.4, and activity 7.7. The SF-12 physical and mental components were respectively, 31.2 and 46.8 pre-op and 50.1 and 53.0 post-op. 12 hips were converted to THA (8 in the þrst 102): 2 neck fractures, 7 femoral loosenings, 1 socket protrusio due to over-reaming, 1 subluxation due to impingement and 1 sepsis. Conclusions: Clinical results are excellent despite very high activity levels. The experience with SA of all cemented metal/UHMWPE bearing demonstrated failure rates of 15%–33% at 3 years. At longer follow-up, the preliminary experience is encouraging (3% failure rate). Dislocation is rare, and acetab-ular þxation secure. Initial femoral þxation is critical as the þxation area is small, especially with osteopenia and cystic degeneration. The percent of complications and potentially adverse radiographic changes was much greater in the þrst 100 cases, during the time of development of instrumentation, technique, and bearing optimization.

Aims: To review the medium term clinical and X-Ray results of DDH in SA, using the Conserve Plusª. Methods: 28 hips (26 patients, avg. age 43.2 years) with DDH were treated with hybrid MMSA. 81% were female. 42% had prior osteotomies. 25% had acetabular cysts that were grafted and 64% had femoral cysts (> 1cm in size) & 1 was grafted. A posterior approach was used in all but one case. Results: Mean F/U was 4.1 years (3.3– 6.5). UCLA hip scores were 3.3, 6.0, 5.7 and 4.5 pre-op and 9.2, 9.3, 9.3 and 7.1 at last F/U for pain, walking, function and activity. SF-12 scores normalized. Range of motion was 121.3û, 73.7û and 83.7û at last F/U for Flexion, abductionadduction, and rotation arcs. 2 hips were converted to THA: 1 for femoral neck fracture at 2 months (neck osteopenia and cystic degeneration) and 1 for recurrent subluxations due to poor offset and impingement due to prior multiple osteotomies. 4 technical complications successfully resolved: 1 trochanteric non-union, 1 post-op dislocation (closed reduction), 1 component mismatch (acetabular component exchange) and 1 femoral nerve palsy. X-ray analysis: 2 pts. presented complete radiolucencies around the metaphyseal stem and 1 patient was symptomatic and will require revision). Conclusions: SA is stable, except for 1 subluxation due to impingement with poor off-set compared to 7–10% with THA. The socket þxation is secure with grafts incorporating whereas prior SA with PE were poor due primarily to socket loosening. Femoral bone preparation is critical to avoid fractures and loosening.

Aims: To review the results and clinical performance of the Anthropometric Total Hip (ATH) with line to line broaching. Methods: 70 press þt titaniumalloy double-wedge taper (136 to 213 mm [mean, 187 mm]) extensively coated grit-blasted (RA=12.0μ) stem prostheses were implanted in 67 patients. There were 29 primary THA, 33 conversions of surface replacements, 6 revision THA and 2 conversions of Hemi-Surface Replacements. The mean age was 55.8 years (range, 20 to 77 years). There were 34 males and 33 females (3 bilateral). The initial etiology was OA (50%), ON (11%), DDH (23%), Post- Trauma (4%), SCFE (2%), Rheumatoid (2%), and Ç other È (8%).Results: The mean follow-up time was 4.7 years (Range: 2–8). UCLA hip scores improved for Pain, Walking, Function, and Activity from 4.8, 6.0, 5.5, and 4.5 pre-operatively to 9.2, 8.3, 7.9, and 5.9 post-operatively. ROM was also comparable to cemented THA results. There were no intra operative fractures. One patient had a bicycling accident, fractured his femoral shaft which healed without surgery. Solid biologic þxation (Ç osseointegration È) was achieved in 100% with the grit-blasted stem. Conclusions: This early investigation shows excellent clinical results, and none of the patients reported any thigh pain. Intra-operative fractures were eliminated with line to line broaching. Our results demonstrate that thigh pain with cementless THA can be essentially eliminated with a titanium-alloy stem and a gentle double-wedge taper geometry. Extensive Ç osseointegration È suggests potential for long term durability.