[Acetabular revision surgery with the oblong revision cup : clinical and radiological results of 217 cases]. / Azetabuläre Revisionsoperationen mit der längsovalen Revisionspfanne : Klinische und radiologische Ergebnisse von 217 Fällen.

BACKGROUND: Deficiencies of the acetabular bone stock are an increasing and challenging problem in revision hip surgery. The LOR oblong revision cup is a valuable option in revision hip surgery. The purpose of this study was to assess outcomes with the LOR revision cup in hips with acetabular bone deficiency, analyze the complications, and identify predictors of survival rate. PATIENTS AND METHODS: From 1996 to 2002, 217 revision surgeries were performed with LOR cups. The mean patient age at operation was 67.5 years (range 29-87 years). The mean postoperative follow-up was 4 years (range 4-100 months). The patients were evaluated clinically and with the Harris hip score (HHS), UCLA score, and WOMAC index. A continuous radiographic assessment was done to detect heterotopic ossifications and radiolucencies or loosening on the basis of the Mayo hip score. Predictors of survival rate were estimated using Kaplan-Meier survivorship analysis. RESULTS: Twenty-four patients (7.4%) died during the study period. Seven patients (3.1%) had revisions because of aseptic loosening and two patients (0.9%) because of infection. Clinical assessment at follow-up showed a significantly improved mean HHS from 45 points preoperatively to 78 points postoperatively. At the most recent follow-up, patients with a body mass index below 30 or those classified as Charnley A had a significantly better HHS. Because of migration on the latest radiographs, revision was indicated in 4.8% of the cases. The survival rate of all LOR implants based on implant removal was 96% after 40 months and 87% after 80 months. Based on radiographic evidence of loosened implants, the survival rate was 94% after 40 months and 79% after 80 months. Patients with more than two revisions had reduced implant survivorship compared with those having one or two revisions. The factors "age at operation", "gender", "obesity", "ASA score", "Charnley score", and "activity according to the UCLA score" did not influence the survival rate. CONCLUSION: We recommend this component in revision surgery on the basis of satisfactory clinical and radiological results at a mean of 48 months of follow-up. We identified the number of revisions as a predictor of survival rate.

[Revision surgery of hip resurfacing]. / Revisionschirurgie des Oberflächenersatzes.

Early results of contemporary hip resurfacing are encouraging and consequently an increasing number of this procedure has been performed worldwide. A theoretical advantage of hip resurfacing is that failed components can be revised safely and successfully revised to a conventional total hip arthroplasty. As the number of systematically analyzed failures is still limited, however, current data from the literature cannot substantially support this assumption. Our personal results indicate that the conversion of a failed femoral cup (i.e., due to neck fracture or aseptic loosening) to a conventional stem is a relatively simple and safe procedure. If and how potential wear of a firmly integrated acetabular component might have any impact on this type of revision, warrants further investigations. The conversion of acetabular components is influenced by the quality of the remaining pelvic bone stock and can therefore be compared to conventional revision surgery. However, as most providers of hip resurfacings systems only offer one-piece acetabular shells, the possibility of an isolated modular insert exchange is rare. In conclusion, the argument of easy revision surgery after hip resurfacing should be used with care.

[Clinical pathways. A useful steering instrument or a limitation for medical treatment?]. / Klinische Pfade. Sinnvolles Steuerungsinstrument oder Beschränkung ärztlicher Handlungsfreiheit?

Clinical pathways can be used to organize the optimal sequence for medical procedures. This process is patient centered and developed through the collaborative work of the participating medical specialties. The goals of clinical pathways are facilitation of outcomes, reduction of variance in patient care and cost containment. Clinical pathways can be used for patient information, internal and external transparency and in total quality management. The management of medical organisations can be supported by introducing the data from clinical pathways into prospective clinical and financial control.

[Results for endoprosthetic care in patients younger than 50 years]. / Ergebnisse endoprothetischer Versorgung bei Patienten vor dem 50. Lebensjahr.

Arthroplasty has become the most successful surgical procedure in developed countries. Replacement of severely damaged joints results in a substantial relief of pain, as the main symptom of osteoarthritis, in the majority of treated patients. With improved results in endoprosthetic surgery over the last decades, however, patients are increasingly undergoing the procedure to enhance their functional capacity and physical mobility. Especially younger patients, who cannot accept a restriction in their professional or sports activity, have become demanding candidates for surgery. This review summarizes the published results on shoulder, hip, knee, ankle and first metatarsophalangeal joint replacement in patients who are younger than 50 years of age. Mid- and long-term follow-up studies in this age group are evaluated in terms of prosthesis survival as well as functional improvement.

[Necrosis of the femoral head in late pregnancy. Necessity of early diagnosis]. / Die peripartale Femurkopfnekrose. Notwendigkeit zur Frühdiagnostik.

Limping and groin pain can issue diagnostic problems during late pregnancy. Differential diagnosis of two idiopathic syndromes, transient osteoporosis and osteonecrosis of the femoral head, is made possible by MRI in the early stages. This case is reported to demonstrate the need to distinguish between those syndromes early so as to prevent further joint damage.

[Resurfacing arthroplasty of the hip]. / Oberflächenersatz am Hüftgelenk.

Currently, an increase in resurfacing arthroplasty in the treatment of hip osteoarthritis--especially in young adults--can be observed. New bearing technologies (mainly metal-on-metal surfaces) show better tribologic results than historical designs (e.g. the Wagner cup). At present, it is unclear whether these modifications and a definitively low dislocation rate--due to the large head diameter--can be supported by further good clinical results. The quantity as well as the quality of the available investigations prevents a definite opinion at the moment. Appropriate clinical studies with documented radiographic follow-up are necessary to compare the outcome of these new implants with standard techniques.

[Hip resurfacing arthroplasty]. / Hüftgelenk-Oberflächenersatzendoprothesen.

In comparison to stemmed total hip replacements, hip resurfacing offers advantages especially in joint stability and amount of femoral bone resection. After the poor results achieved with this concept that were mainly caused by failure of the materials used, reintroduction of the metal-on-metal bearing initiated a renaissance. This bearing, the cementless cup, and the improved surgical technique led to better short- to medium-term results. Revision and complication rates are now comparable to conventional total hip replacements. The functional capacity of the method is higher. Because long-term results are not available, however, questions remain, for instance, the consequences of the higher metal ion serum concentrations or the impossibility of changing the inlay when femoral revision becomes necessary.

[Functional results after surface replacement of the hip: comparison between dysplasia and idiopathic osteoarthritis]. / Funktionelle Behandlungsergebnisse nach Oberflächenersatz am Hüftgelenk: Vergleich zwischen Dysplasie- und idiopathischer Koxarthrosen.

AIM: To determine if there are differences in function after resurfacing arthroplasty of the hip in patients with primary osteoarthritis compared to patients with secondary osteoarthritis due to developmental dysplasia of the hip. METHOD: In a controlled prospective study of Birmingham Hip Resurfacing (BHR) we included all patients with primary osteoarthritis (n = 54, average age 48.4 years) and osteoarthritis due to high grade dysplasia (Eftekhar B, n = 34, average age 55.8 years). Standardized clinical (Harris hip score) and radiographic examinations were performed 6 weeks, 3 months and 6 months and then every year after the operation. RESULTS: All patients could be followed up to 1.5 years (1-4 years) after surgery. The average Harris hip score improved to 82-95 points in both groups 3 months postoperatively. Statistically significant differences could be found in the subscales "function" and "limp", where patients with dysplastic hips showed somewhat lower results after 6 (function) to 12 weeks (limp) postoperatively. This is probably attributable to extended non-weight-bearing after acetabular reconstruction in these cases, as the difference disappeared with full weight-bearing. Radiographically determined neck-shaft angles are slightly higher in dysplastic hips (142 degrees versus 135 degrees ), but we did not recognize any significant differences in implant positioning. CONCLUSION: The short- to mid-term results showed no clinically relevant functional differences after surface replacement in patients with primary osteoarthritis of the hip and patients with secondary osteoarthritis due to higher grade dysplasia. Long-term observation is necessary, however, to determine if these positive functional results are reflected by appropriate radiographic survival.

[Urinary concentration of collagen metabolites in endoprosthesis loosening]. / Harnkonzentrationen von Kollagenabbauprodukten bei Endoprothesenlockerungen.

Aseptic loosening is the most common long-term complication in arthroplasty. Loosening is in every case associated with bone resorption at the interface that leads to bone defects and complicates the revision. The diagnosis of aseptic loosening is based on clinical and radiological evaluation. Especially in clinically asymptomatic cases an early diagnosis with these methods is difficult. In our study we wanted to evaluate the diagnostic value of biochemical markers of the bone resorption in aseptic loosening. We compared 58 patients with proven implant loosening during surgery with 67 patients without clinical or radiological signs of loosening. We measured the crosslinks pyridinoline and hydroxypyridinoline in urine samples. In contrast to Schneider et al. [increased urinary crosslink levels in aseptic loosening of total hip arthroplasty, J. Arthroplasty 1995; 13 (6): 687-692] we found no significant differences between loose and asymptomatic hip or knee prosthesis. Also no correlation between the size of the acetabular defects of loose hip implants and the urinary crosslink excretion was measurable. Our results show no or only little diagnostic value of the urinary crosslinks pyridinoline and deoxypyridinoline in aseptic loosening of total hip and knee arthroplasty.