Background: This report presents the long term (over 20 years) experience with the use of a grit-blasted, press-fit femoral prosthesis.

Methods: The first 300 consecutive primary THA procedures using a collarless, three-dimensional tapered, straight, titanium alloy stem with a grit-blasted surface (performed in 299 patients) were evaluated up to twentytwo years. A cementless all-polyethylene socket in 80 percent of the cases, were used. Radiographic evaluation, performed by an independent observer using a zonal analysis method, included assessment of component migration, Engh’s implant-bone femoral fixation score, implant-bone demarcations, and periprosthetic osteolysis. The average duration of long-term radiographic follow-up was 12.6 years (range; 10 to 16 years).

Results: At last examination only five hips were lost to follow-up and 84 patients were deceased. The femoral revision rate was 7 percent (two hips for aseptic loosening, five hips for septic loosening, and twelve hips with osseointegrated stems for severe progressive femoral osteolysis) and the acetabular revision rate was 28% (revised for either socket migration or progressive peri-acetabular osteolysis or both). Survivorship, based on any revision (femoral or acetabular) was 89% at ten years and 65% at twenty years; survivorship of the femoral component was 95% at ten years and 89% at twenty years. The incidence of femoral periprosthetic osteolysis, was 47%, with 5% of distal endosteal osteolysis. Radiographic femoral implant-bone fixation was stable, bone-ongrowth in 97%; stable, fibrous-fixation in 1%.

Conclusions: The grit-blasted, press-fit, collarless, tapered femoral component continued to perform well clinically and radiographically up to twenty years of follow-up despite the challenging environment of peri-prosthetic osteolysis associated with the acetabular component design. This implant is still in use virtually without design modifications. This study demonstrates the durability of the results of the grit-blasted femoral component and indicates that such an implant offers a viable alternative for fixation without bone cement.

Purpose: The effect of cemented total hip arthroplasty (THA) stem surface finish and geometry on clinical outcomes is controversial. This is the first report of results from a multi-center study evaluating a cemented, polished, triple-tapered prosthesis.

Methods: Two-hundred-seventeen C-Stems (DePuy, Warsaw, IN, USA) were implanted consecutively at three centers. Hips with 2-year minimum A-P radiographs receiving prospective clinical and independent retrospective radiographic examinations were included. Seven patients (9 hips) died and two had early revisions (one trauma-induced loosening; one due to poor cement technique). Of 206 hips remaining, 162 reached minimum follow-up. Cement-mantle grade, subsidence, stem-cement radiolucency, femoral osteolysis, and Harris Hip Score (HHS) were recorded annually.

Results: Mean age was 70 years (range 39–100). Of the 162 patients evaluated, 103 were female and 59 male. There were 17 deaths (20 hips) after minimum follow-up. Mean radiographic follow-up was 4 years (range: 2–6). At last follow-up, the mean HHS was 88 (range: 44–100). Cement-mantle grades were: A(27%), B(49%), C1(6%), C2(14%) and undetermined(4%). No stem subsidence greater than 2mm was observed. Debonding more than 1mm was noted in 6 hips (4%), including one cement fracture. Of 3 hips (2%) with femoral osteolysis, two instances were exclusively in proximal zones.

Conclusions: Excellent to good results were obtained in this multi-center, cemented, triple-tapered THA stem series. Radiographic results were similar to published results from other successful stems sharing these features. Further research is warranted to determine whether long-term results compare favorably to others designed to resist subsidence and loosening.

Press-fit acetabular reconstructions have become the standard THA; however, controversies remain. The purpose of this study was to critically evaluate serial radiographs for initial cup stability, i.e. gaps and signs of periacetabular interface changes for a porous tantalum monoblock socket.

A multicenter study evaluating 574 primary THRs (542 patients) performed by 9 surgeons at 7 hospitals, all with a monoblock cup without screws. Analyses included clinical outcomes and detailed 2-year minimum radiographic evaluation by one independent observer (mean follow-up, 33 months).

Complications included 9 intra-operative acetabular fractures. Among the 123 cases excluded from radiographic evaluations: deceased (19), lost-to-follow-up (8), 7 early revisions (recurrent dislocations (6) and one trauma-related loosening), and sepsis (3). Patient demographics (414 hips): mean age 65 years (19–93); 58 percent females. Baseline radiographs revealed 113 zones in 85 hips (21 percent) with acetabular gaps; 36 in zone I, 72 in zone II, and 5 in zone III. Of these radiolucencies, 57 zones were 1 mm or less and 56 zones ranged from 2 to 5 mm. At last follow-up, 64 hips (75 percent) had complete gap fill-in, including 100 percent of gaps greater than 3 mm.

There were no socket migrations, no evidence of lysis, no revisions for loosening, and no complete periacetabular interface radiolucencies. The fill-in of preexisting OA cysts and gaps is attributed to adequate initial stability and osteointegration into the porous tantalum. These results suggest that a monoblock cup without screws is an attractive option in THA.

Introduction and Aims: To review the medium-term clinical and x-ray results of metal-on-metal Surface Arthroplasty (MMSA) in DDH, using the Conserve Plus™.

Method: Fifty hips (44 patients, avg. age 42.7 years) with DDH were treated with hybrid MMSA. Seventy-five percent were female. Ten percent had prior osteotomies. Twenty-five percent had acetabular cysts that were grafted and 64% had femoral cysts (> 1cm in size) and one was grafted. All cases were Crowe Class 1 or 2. A posterior approach was used in all but one case.

Results: Mean follow-up was 4.9 years (3.8–7.8). UCLA hip scores were 3.2, 5.9, 5.5 and 4.4 pre-op and 9.2, 9.5, 9.4 and 7.1 at last follow-up for pain, walking, function and activity. SF-12 scores normalised. Range of motion was 126.6 degrees, 80.5 degrees and 83.2 degrees at last follow-up for flexion, abduction-adduction, and rotation arcs. Four hips were converted to THA: 2 for femoral neck fracture at two and five months, one for recurrent subluxations due to poor offset and impingement due to prior multiple osteotomies, and one for femoral component aseptic loosening. Four technical complications successfully resolved: one trochanteric non-union, one post-op dislocation (closed reduction), one component mismatch (acetabular component exchange) and one femoral nerve palsy. X-ray analysis: two patients presented complete radiolucencies around the metaphyseal stem.

Conclusion: SA is stable, except for one subluxation due to impingement with poor offset compared to seven to 10% with THA. The socket fixation is secure without adjunct fixation 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.

Introduction: THR is still the standard of care for young arthritic patients. However, failure rates remain high at 10 years follow-up, with rates of up to 33% in all cemented designs and 10.5% in cementless designs. With the arrival of new, more wear-resistant bearings, Surface Arthroplasty (SA) has become a viable and promising solution for this patient population. The purpose of the present study was to investigate the results of a metal-on-metal (M/M) hybrid SA and identify appropriate criteria for patient selection.

Method: The first 400 hips (of 620) 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%, Inflammatory arthritis 3%, SCFE and LCP 4%, Melorheostosis 0.3%.

Results: Mean follow-up 5.2 years (3.9–7.8). 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. Fifteen hips were converted to THA (nine in the first 102): two neck fractures, 10 femoral loosenings, one socket protrusio due to over-reaming, one subluxation due to impingement and one sepsis. The three most important risk factors for femoral loosening and radiolucencies were large cyst formation (p=0.0067), female gender (p=0.0001), and lighter weight in male patients (p=0.0003). The occurrence of femoral loosening or lucency was 18% for the first 100 cases, 9% for the second, 8% for the third, and 1% for the last 100 cases.

Conclusion: Clinical results are excellent, despite very high activity levels. The experience with SA of all cemented metal/UHMWPE bearing demonstrated failure rates of 15 to 33% at three years. At longer follow-up, the preliminary experience is encouraging (3.75% failure rate). Dislocation is rare, and acetabular fixation secure. Initial femoral fixation is critical, as the fixation area is small, especially with osteopenia and cystic degeneration. Cementing the femoral metaphyseal stem appears as a meaningful technical improvement towards the prevention of early femoral radiolucencies. None of the 59 cemented metaphyseal stem had any radiolucency at last review.

Aims: Examine the short term failures of the Wright Medical Conserve Plusª metal-on-metal hip resurfacing to determine risk factors, so that measures could be implemented to prevent future failures. Methods: Two hundred and ninety six Conserve Plus hip resurfacings were performed in an FDA IDE multi-center trial. 9 femoral neck fractures occurred in 3 of the 9 centers. The time to failure ranged from less than 1 week to 21 weeks. The revised resurfaced heads were sectioned and examined by micro-radiography and histology, along with pre and post-operative radiographs and clinical histories that were discussed with the surgeons. Results: Several risk factors were identiþed including poor bone quality large or multiple cysts in the femoral head or neck, leaving reamed bone uncovered, improper implant placement and incorrect patient selection. Lessons learned from this analysis resulted in no further neck fractures to date in 369 additional Conserve Plus components that have now been implanted. Conclusions: Osteoarthritic femoral necks rarely fracture and neck fracture in resurfaced femoral heads can be largely prevented by better patient selection, improved surgical technique to prevent neck notching and better implant placement.

To review short to medium term results of a metalon-metal (M/M) hybrid surface arthroplasty (SA) for a young and active patient population.

The first 300 hips (of 564) in 263 patients underwent M/M hybrid surface arthroplasty (cementless acetabular and cemented femoral components). Demographics: mean age 48.4; 75% males, 25% females; 141 Charnley Class A; 109 Class B and 13 Class C. Diagnosis at surgery: OA 67%, DDH 10.3%, ON 8.3%, Post-traumatic 6.7%, Inflammatory arthritis and Rheumatoid Disease 4%, SCFE and LCP 3.4%, Melorheostosis 0.3%.

Mean follow-up 3.6 years (2.5–5.9). Average UCLA hip scores post-op: pain 9.4, walking 9.5, function 9.4 and activity 7.7. Average Harris Hip Score was 92.8. The SF-12 physical and mental components were respectively, 31.4 and 47.2 pre-op and 49.9 and 52.9 post-op. DEXA data suggests preservation or restoration of neck BMD.

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 (3.6% failure rate) and eventual conversions to THR are facilitated with unipolar heads. The technique preserves femoral and ace-tabular bone, dislocation is rare, and acetabular fixation secure. Initial femoral fixation is critical as the fixation area is small, especially with osteopenia and cystic degeneration. The percent of potentially adverse radiographic changes was much greater in the first 100 cases, during the time of development of instrumentation, technique, and bearing optimisation.