Cementless total hip arthroplasty with a tapered, rectangular titanium stem and a threaded cup: a minimum ten-year follow-up.
ABSTRACT We report the results of cementless total hip arthroplasty with a tapered, rectangular titanium stem that was introduced in 1979 and continues to be used today with only minor changes. The aim of the design is to achieve primary stability to resist rotational and axial forces through precision rasping and press-fit implantation of a tapered, rectangular femoral component.
Between October 1986 and November 1987, 208 total hip arthroplasties with insertion of a tapered, rectangular titanium stem and a threaded cup without cement were performed in 200 consecutive patients (average age, sixty-one years; range, twenty-two to eighty-four years).
At the time of the latest follow-up, fifty-one patients (fifty-two hips) had died and sixteen patients had been lost to follow-up, leaving 133 patients. Twelve hips had been revised, two in patients who subsequently died, leaving 123 living patients without revision. The median follow-up time was 120.7 months. Five cups needed revision surgery because of aseptic loosening; two, because of massive polyethylene wear; one, because of posttraumatic migration; and one, because of breakage. Three femoral stems were revised: one because of malpositioning (the reoperation was done five days after implantation); one, because of infection; and the third, after multiple failed acetabular revisions. The mean Harris hip score for the patients who did not have revision was 85.4 points (range, 46 to 100 points) at the time of the latest follow-up. Four patients (3%) complained of thigh pain that was not associated with another disorder. According to the criteria of Engh et al., all femoral implants were graded as stable bone-ingrown. The probability of survival of both the femoral and the acetabular component at ten years, with any revision as the end point, was 0.92 (95% confidence interval, 0.88 to 0.97). The probability of survival of the cup was 0.93 (95% confidence interval, 0.89 to 0.97), and that of the stem was 0.99 (95% confidence interval, 0.97 to 1.00).
The results of arthroplasty with a tapered, rectangular titanium stem combined with a conical threaded cup inserted without cement were excellent at a minimum of ten years. Our data suggest that femoral stem fixation continues to be secure, while the threaded cup is prone to aseptic loosening.
[show abstract] [hide abstract]
ABSTRACT: The tapered rectangular press fit femoral component design of Karl Zweymüller remains highly successful since its inception in 1979. The longitudinal taper and rectangular cross-section provide unequaled primary stability, which promotes consistent secondary osseointegration to the grit-blasted titanium surface, even in osteoporotic bone. The "fit without fill" concept provides for bone conservation and preservation of the intraosseous blood supply by compaction, rather than removal, of the metaphyseal cancellous bone. The surgical technique is simple and forgiving, allowing for infinite adjustability in stem height and anteversion. Numerous long-term studies report excellent clinical results with a negligible incidence of loosening, thigh pain, osteolysis, or significant stress shielding and survivorships approaching 100% at 10 years.The Journal of Arthroplasty 07/2005; 20(4 Suppl 2):63-7. · 2.38 Impact Factor
Article: Cemented versus non-cemented hemiarthroplasty of the hip as a treatment for a displaced femoral neck fracture: design of a randomised controlled trial.[show abstract] [hide abstract]
ABSTRACT: A discussion is ongoing whether displaced femoral neck fractures in elderly patients should be treated with a non-cemented or a cemented hemiarthroplasty. A recent Cochrane analysis stresses the importance of further research into the relative merits of these techniques. We hypothesise that non-cemented hemiarthroplasty will result in at least the same technical-functional outcome and complication rate, with a shorter operation time. A randomised controlled multicentre trial will be performed.The study population consists of 200 patients of 70 years and older. Patients with a displaced femoral neck fracture will be allocated randomly to have a cemented or a non-cemented hemiarthroplasty. Data will be collected preoperatively, immediately postoperatively, and 6 weeks, 3 months and 1 year postoperatively.The main outcome measures of this study are technical-functional results of the hemiarthroplasty, duration of surgery, complications, and mid-thigh pain. Secondary outcome measures are living conditions at final follow up, self-reported health-related quality of life, and radiological evaluation of the hemiarthroplasty. A recent Cochrane analysis did not find arguments in favour of either non-cemented or cemented hemiarthroplasty. The forthcoming trial will compare treatment for a displaced femoral neck fracture by cemented versus non-cemented hemiarthroplasty. Our results will be published as soon as they become available. Trial Registration Number NTR1508.BMC Musculoskeletal Disorders 02/2009; 10:56. · 1.58 Impact Factor
Article: Prospective study of a cementless total hip arthroplasty with a collum femoris preserving stem and a trabeculae oriented pressfit cup: minimun 6-year follow-up.[show abstract] [hide abstract]
ABSTRACT: Tissue sparing hip prostheses are becoming more and more popular especially for the treatment of younger patients. The objective of this study was to evaluate the clinical and radiological results after insertion of a tissue sparing hip prosthesis. In 47 consecutive non-selected patients (50 hips), the clinical and radiographic results of cementless total hip arthroplasty using a collum femoris preserving stem, a pressfit cup and an alumina-polyethylene pairing were prospectively evaluated. The mean age at index-surgery was 58 (36-82) years, there were 38 women and 9 men. After a mean follow-up of 6.8 years (minimum 6.1 years), two patients had died and one patient underwent revision surgery due to aseptic loosening of the stem. The overall survival rate of the acetabular component was 100% and of the femoral component 98%. The mean Harris hip score at follow-up was 94 points. The mid-term survival with this type of total hip arthroplasty is excellent and compares equal with uncemented straight stems in this age group.Archives of Orthopaedic and Trauma Surgery 10/2010; 131(4):549-55. · 1.37 Impact Factor