Aims: The aim of this study is to present long-term results of the cementless Alloclassic total hip arthroplasty system of up to 21 years.

Matarial and Methods: 152 consecutive primary hip arthroplasties using a threaded conical titanium cup (Alloclassic CSF) and a rectangular titanium press-fit stem (Alloclassic SL) were implanted between September 1987 and December 1988. In all cases a 32 mm alumina ceramic head and a UHMW polyethylene inlay were used. Clinical and radiological results were available for 55 patients (36,2%) with a minimum of 15 years (15.0 to 20.9 years). Clinical results were evaluated according to the Harris Hip Score, the SF-36 and WOMAC score. Radiographic results were analysed on anteroposterior x-rays according to the method of DeLee and Charnley for the cup and of Gruen for the stem.

Results: The average Harris Hip Score at the last follow-up was 87.3. The mean pain score was 41.5, the mean functional score 47.3. Radiographic results showed osteolytic lesions around the cup in one case. Radiolucent lines around the stem were observed only in the proximal zones in 2/3 of the cases, cortical hyperthrophy occurred in the distal zones in ¾ of the evaluated hips.

23 hips (15.1%) needed revision surgery. The majority (17 hips – 73.9% of all reoperations) were revised due to progressive Polyethylene wear, all after a minimum of ten years. Exchange of the polyethylene inlay and the ceramic head was performed in 14 hips. In two cases the acetabular component and in one case the femoral component were found to be loose intraoperatively because of the wear debris and had to be exchanged. 4 hips had to be revised due to aseptic cup loosening without signs of increased polyethylene wear. There was one revision due to a late deep infection and one because of a periprothetic femoral fracture.

Conclusion: Our data suggest that excellent long-term results can be achieved with the cementless Alloclassic system. The main limiting factor for implant survival was found in increased polyethylene wear. We therefore recommend early exchange of the inlay to avoid loosening and the use of modern wear couples such as ceramic-on-ceramic, metal-on-metal or crosslinked polyethylene.

Aims: The aim of this study is to present clinical and radiographic long-term results including a survival analysis of the cementless Alloclassic total hip arthroplasty system.

Matarial and Methods: 103 consecutive primary hip arthroplasties using a threaded conical titanium cup (Alloclassic CSF) and a rectangular titanium pressfit stem (Alloclassic SL) were evaluated clinically and radiographically with an average follow-up period of 14.4 years (range 10.2 to 17.1 years). In all cases a 32 mm alumina ceramic head and a UHMW polyethylene inlay were used. Clinical results were evaluated according to the Harris Hip Score, the SF-36 and WOMAC score. Radiographic results were analysed on antero-posterior x-rays. A statistical survivorship analysis was calculated using Kaplan-Meier curves.

Results: The average Harris Hip Score at the last follow-up was 89.2. The mean pain score was 41.6, the mean functional score 47.6. Radiographic results showed a continuous radiolucency around the cup in three cases. Radiolucent lines around the stem were observed only in the proximal zone 1 in 52 and in zone 7 in 26 cases. Cortical hyperthrophy occurred in the distal zone 3 in 33 cases and in zone 5 in 72 cases. Fifteen hips were revised, eleven of them because of increased polyethylene wear after a minimum follow-up of 10 years. One patient needed revision due to a late deep infection after 7.4 years. There were three cases of aseptic loosening without signs of progressive polyethylene wear that led to a cup exchange. The cumulative survivorship with revision due to aseptic component loosening as endpoint was 95.6 % for the cup and 100 % for the stem after 15 years.

Conclusion: Our data suggest that excellent long-term results can be achieved with the cementless Alloclassic system. The main limiting factor for implant survival was found in increased polyethylene wear. We therefore recommend early exchange of the inlay to avoid component loosening and the use of modern wear couples such as ceramic-on-ceramic, metal-on-metal or crosslinked polyethylene.

Aims: Minimal invasive total hip replacement is supposed to allow a quicker rehabilitation in the immediate post-operative period due to reduced soft tissue damage. The aim of this study is to compare gait kinematics after total hip arthroplasty using a one incision minimal invasive approach to a traditional approach.

Matarial and Methods: 21 patients were available for a complete analysis. In 12 patients (MIS group) a minimal invasive, modified Watson-Jones approach was used, in 9 patients (Standard group) a transgluteal approach as described by Bauer was used. All operations were performed by a single surgeon with the patient in supine position. In all cases the same cementless implant (Alloclassic® VariallTM system) with standard instruments was used. 3D gait analysis was carried out pre-operatively, 10 days postoperatively and after 3 months. The variables analysed in this study were velocity, step length, range of hip extension, range of pelvic tilt, Trendelenburg’s sign and Duchenne limp, pelvic rotation and symmetry.

Results: There were no significant differences between the MIS and the Standard group in any of the evaluated variables. In both groups of the patients presented a decrease in the hip extension at the end of stance phase 10 days postoperatively. About half of these patients compensated with an increased sagital pelvic tilt during maximal hip extension. At the 3 months follow-up all patients in both groups had an increased hip extension compared to the preoperative values, reached normative values. The velocity was reduced in both groups at the 10 days follow-up, ¼ reached normative values after 3 months.

Conclusion: Our data show no significant improvement of gait kinematics in patients who underwent a total hip arthroplasty using a minimal invasive approach (modified Watson-Jones) compared to a standard approach (Bauer) during the early postoperative period.

Two Durasul highly crosslinked polyethylene liners were exchanged during revision surgery four and five years after implantation, respectively. The retrieved liners were evaluated macroscopically and surface analysis was performed using optical and electron microscopy. A sample of each liner was used to determine the oxidation of the material by Fourier transform infrared spectroscopy. Samples of the capsule were examined histologically.

The annual wear rate was found to be 0.010 and 0.015 mm/year, respectively. Surface analysis showed very little loss of material caused by wear. Histological evaluation revealed a continuous neosynovial lining with single multinucleated foreign-body giant cells. Our findings showed no unexpected patterns of wear on the articulating surfaces up to five years after implantation and no obvious failure of material.

Background: There are many clinical and radiographic long term results of Total Hip Arthroplasties reported in literature but very few attend to the subjective quality of life of patients living with an implant. In the last few years different quality of life assessment scores were developed. In this study the subjective SF-36 and the WOMAC score were evaluated and the results were compared to the commonly used clinical Harris Hip Score.

Patients and methods: From a total number of 152 cement-less Total Hip Arthroplasties (Alloclassic®) performed between October 1987 and December 1988 at our clinic, 103 hips in 99 patients were available for a clinical and radiographic evaluation with an average follow-up of 14.3 years. For clinical evaluation the Harris Hip Score was used. Additionally all patients got SF-36 and WOMAC questionnaires. 78 questionnaires were returned fully completed and could be evaluated. The overall results and the results in the domain “pain” and “function” which occur in all three scores were compared statistically.

Results: The mean Harris Hip Score was 88.2 (range 24 – 100), pain score 41.9 and function score 48.4. The mean WOMAC Score was 10.6 in total, pain 2.8 and function 3.9. The SF-36 domain “Bodily Pain” was 56.6 and “physical function” 48.2. Concerning the domain “function” a significant correlation was found in all of the three scores (p < 0.01). A significant “pain” correlation was seen comparing the SF-36 to the WOMAC score (p < 0.01). No significant correlation was found comparing the clinical Harris Pain Score to the SF-36 domain “Bodily Pain” and to the WOMAC pain score.

Conclusion: In this study the subjective assessment questionnaires SF-36 and WOMAC show significant similar results to the clinical Harris Hip Score concerning the domain “function”. Concerning “Pain” comparable results were found between the SF-36 and the WOMAC with no significant correlation to the HHS. These data suggest that the quality of life assessment questionnaires can not replace the clinical evaluation using a clinical score.

We carried out a clinical and radiological review of 103 cementless primary hip arthroplasties with a tapered rectangular grit-blasted titanium press-fit femoral component and a threaded conical titanium acetabular component at a mean follow-up of 14.4 years (10.2 to 17.1).

The mean Harris hip score at the last follow-up was 89.2 (32 to 100). No early loosening and no fracture of the implant were found. One patient needed revision surgery because of a late deep infection. In 11 hips (10.7%), the reason for revision was progressive wear of the polyethylene liner. Exchange of the acetabular component because of aseptic loosening without detectable liner wear was carried out in three hips (2.9%).

After 15 years the survivorship with aseptic loosening as the definition for failure was 95.6% for the acetabular component and 100% for the femoral component.

Aims: The purpose of this paper is to evaluate the effectiveness of cementless total hip arthroplasty using a threaded acetabular component with a titanium press þt stem. Methods: A total number of 179 cementless primary total hip arthroplasties was performed consecutively using a tapered rectangular gritblasted titanium press þt stem and a threaded conical titanium cup. Articulating wear partners were a ceramic ball head and an UHMW polyethylene inlay. At the time of evaluation with a minimum follow-up of 10 years 57 patients had died and 18 were not available for follow-up, thus leaving 104 consecutive, non-selected hips in 100 patients for clinical and radiographic examination after an average follow-up period of 11.6 years (range 10.0 to 14.2 years). Results: The average Harris Hip Score at the time of the latest follow-up was 88.7 (range 24 to 100). In 9 hips (5,0%) a revision was performed: in 6 cases (3,4%) the reason for revision was increased polyethylene wear. 2 cups (1,1%) were revised because of pain and radiographic signs of aseptic loosening without presence of increased wear. One hip had to be revised due to late deep infection after 7,2 years. All stem implants were rated stable. The probability of survival of both the ace-tabular and femoral component at 12 years with any reason for revision as endpoint was 94,8% (95% con-þdence interval). The survivorship with revision due to aseptic loosening of a component as endpoint was 97,7%. Conclusion: The design and material used for the threaded cup and tapered stem are decisive factors for the success of this cementless implant. With the above evaluated total hip system favourable long term results over a period of more than 10 years could be achieved.