In this study the authors investigated the results of different designs of cementless THRs using ceramic/ceramic components. The authors analyzed the clinical results taking into account the age of the patients and of the type of implants used and also developed some basic considerations with regard to the interaction between AI2O3 ceramics and human tissue.

In this study the authors investigated the results of different designs of cementless THRs using ceramic/ceramic components. The authors analyzed the clinical results taking into account the age of the patients and of the type of implants used and also developed some basic considerations with regard to the interaction between AI2O3 ceramics and human tissue.

We revised seven alumina-blasted cementless hip prostheses (Ti-alloy stems, cp Ti threaded sockets) with low- or high-carbon Co-alloy bearings at a mean of 20.1 months after implantation because of pain and loosening. Histological examination of the retrieved periprosthetic tissues from two cases in which the implant was stable and three in which the socket was loose showed macrophages with basophilic granules containing metal and alumina wear particles and lymph-cell infiltrates. In one of the two cases of stem loosening the thickened neocapsule also contained definite lymphatic follicles and gross lymphocyte/plasma-cell infiltrates. Spectrometric determination of the concentration of elements in periprosthetic tissues from six cases was compared with that of joint capsules from five control patients undergoing primary hip surgery. In the revisions the mean concentration of implant-relevant elements was 693.85 microg/g dry tissue. In addition to Cr (15.2%), Co (4.3%), and Ti (10.3%), Al was predominant (68.1%) and all concentrations were significantly higher (p < 0.001) than those in the control tissues. The annual rates of linear wear were calculated for six implants. The mean value was 11.1 microm (heads 6.25 microm, inserts 4.82 microm). SEM/EDXA showed numerous fine scratches and deep furrows containing alumina particles in loosened sockets, and stems showed contamination with adhering or impacted alumina particles of between 2 and 50 microm in size.

Due to our results, a one stage procedure with open synovectomy and implantation of cemented total knee endoprostheses seems to be a considerable alternative for the treatment of geriatric patients suffering from knee empyema and severe osteoarthritis.

We compared wear particles from two different designs of total hip arthroplasty with polycrystalline alumina-ceramic bearings of different production periods (group 1, before ISO 6474: group 2, according to ISO 6474). The neocapsules and interfacial connective tissue membranes were retrieved after mean implantation times of 131 months and 38 months, respectively. Specimen blocks were freed from embedding media, either methylmethacrylate or paraffin and digested in concentrated nitric acid. Particles were then counted and their sizes and composition determined by SEM and energy-dispersive x-ray analysis (EDXA). The mean numbers and sizes of most alumina wear particles did not differ for both production periods, but the larger sizes of particle in group 1 point to more severe surface destruction. The increased metal wear in group 2 was apparently due to alumina-induced abrasion of the stems. In this study the concentrations of particles in the periprosthetic tissues were 2 to 22 times lower than those observed previously with polyethylene and alumina/polyethylene wear couples.

Issue: Is a one stage procedures with: open synovectomy and implantation of cemented knee endoprostheses in patients with empyemas of the knee and concomittant, osteoarthritis suitable to reduce morbidity and increase early mobility? Method: Three female patients (age empty set 88 yrs.) with acute empyema of arthritic knee joints (Pathogen: Staph. aureus) were treated with open synovectomies and implantations of cemented TKA's in a one stage procedure at mean 3 days, (1-6) after admittion. After 4.6 months (3-6) we carried out:the last clinical and radiographic examination and after 15 months (11-21) a telephone questionare. Results: The mean operation time was 2,4 hrs. (2-3), the perioperative blood loss at mean 1040 cc (800-1180 cc) and patients received 4 units blood (4-5). Parenteral antibiotics were administered for at mean 21 days (18-25 d). 33 days (27-39) after surgery the patients could be discharged, all of them ambulated with a walker, the operated joints had no signs of infection and blood parameters i.e. leucocyte count, crp and ESR dropped. At the: time of the latest follow up examination there were neither clinical nor radiographic any signs that infections recurred. Two patients-ambulated with crutches, one still with a walker. The HSS-Score increased from preop. 54 pts. up to 80 pts. at the follow up. Conclusion: Due to our results, a one stage procedure with open synovectomy and implantation of cemented total knee endoprostheses seems to be a considerable alternative for the treatment of geriatric patients suffering from knee empyema and severe osteoarthitis.

In 12 human cadaver tibiae, osteotomies were carried out at two levels (2 and 3 cm from the distal joint line) with three different wedges (5°, 10°, 15°) to evaluate the influence of displacement of the osteotomy fragments on areas of cortical contact. In undisplaced osteotomies (medical cortical edges superposed) cortical contact areas formed 28% (level 2 cm) and 40.5% (level 3 cm) of the cortical circumference of the proximal fragments (NS). Wedge angles and levels of osteotomy displayed no statistical differences. In displaced osteotomies cortical contact decreased significantly ( P < 0.05). Displacing the distal fragment laterally, medial cortical contact is lost, and weight-bearing leads to revarisation as cancellous bone sustains only 3 MPa, and the measured compressive stresses at the medial edge amounted to 6 MPa on average. Displacing the distal fragment medially leads to a decrease of total cortical contact, too, but at the medial edge of the osteotomy cortical contact areas are still present. As a result of the study, postoperative weight-bearing without additional plaster cast fixation is recommended only in cases with undisplaced fragments.

Antibiotic treatment of orthopedic infections may result in the developement of Antibiotic-Associated colitis (AAC). Clinical symptoms such as colic tenesmus and diarrhoea are often associated with therapy-induced overgrowth of Clostridium difficile in the colon but clinically asymptomatic cases with only rising C-reactive protein values or increasing leucocyte counts are also reported. In a retrospective study we identified 34/603 patients (5,6%) with orthopedic infections complicated by an AAC who were treated at our departement between 1/90 and 2/95. Infections developed after orthopedic operations as early infections in 11 cases and as late infections in 5 patients. Eighteen patients suffered from bone-or soft tissue infections. Surgical intervention was carried out in 26 cases and all 34 patients were given intravenous antibiotics (29 cases with clindamycin as single therapy or in combination). First signs of AAC occured at an average of 16 days (range 3 to 37). Clinical symptoms developed in 27 patients, elevated temperature in 4 and a rise of C-reactive protein and leucocyte count without abdominal symptoms in 3 patients. Diagnosis of Clostridium difficile in the stool of patients was carried out using a latextest and stool cultures in parallel. Together with oral colitis therapy in 31 patients antibiotic therapy was stopped in 17 cases, changed in 11 and continued in the remaining 5. One patient died due to a myocardial infarct on the day of diagnosis — the remaining 33 patients were discharged after successful treatment of their primary disease and the colitis. As a result we recommend not using clindamycin in older patients or patients with a history of colitis.

41 draining sinuses after THR were treated by debridement without exchanging the implants. Positive bacterial cultures were obtained in 23 patients-the ilio tibial tract was found open in 19 cases (82%). The bacterial cultures were negative in 18 patients-the ilio tibial tract was found open in 7 cases (38%). Revisions took place 21 days (9-43) after primary implantation. At the time of the follow up (0 72 months postoperatively) 7 patients had been revised (8-97) because of recurrence of infection. The results of debridements of contaminated sinuses depend on the ilio tibial tract. Revisions were successful in three out of four paces with an intact, and only in eight out of nineteen cases with an open ilio tibial tract. Besides proper bacterial investigation preoperative sinograms give useful information about the prognosis of revision. In cases with positive bacterial cultures debridements should be done very early to eradicate infection without removing the implants.

41 draining sinuses after THR were treated by debridement without exchanging the implants. Positive bacterial cultures were obtained in 23 patients-the ilio tibial tract was found open in 19 cases (82%). The bacterial cultures were negative in 18 patients-the ilio tibial tract was found open in 7 cases (38%). Revisions took place 21 days (9-43) after primary implantation. At the time of the follow up (0 72 months postoperatively) 7 patients had been revised (8-97) because of recurrence of infection. The results of debridements of contaminated sinuses depend on the ilio tibial tract. Revisions were successful in three out of four paces with an intact, and only in eight out of nineteen cases with an open ilio tibial tract. Besides proper bacterial investigation preoperative sinograms give useful information about the prognosis of revision. In cases with positive bacterial cultures debridements should be done very early to eradicate infection without removing the implants.

The first 100 consecutive cemented Weller-type total hip arthroplasties carried out between 1976 and 1977 were reexamined. Clinical analysis of 43 implants with more than 10 years follow-up showed that results were excellent in 21 patients (49%), good in 13 (30%), fair in 7 (16%) and poor in 2 (5%). Radiographic analysis revealed 33 (87%) stable femoral and 31 (81%) stable acetabular components. Statistical survivorship analysis of all 100 implants produced a probability of reoperation of 6.2%, a probability of radiographic implant loosening of 28.2% and a probability of radiographic loosening with clinical symptoms of 7.6%. The definition of failure should be "radiographic loosening of the prosthesis with clinical symptoms" because this evaluation seems to have the best clinical relevance. Concerning the fact that the cement fixation was not performed to today's standard, the results after more than 10 years with this total hip system (Weller long stem) are sufficient.

Thirty-three patients were operated for septic (n = 20) and aseptic (n = 13) loosening of their hip prostheses using Girdlestone's operation over 10 years. An average of 46.6 months later, 22 of these patients were given a follow-up examination. Clinical evaluation according to Harris showed an improvement in mean values from 25 to 53 points, which can be attributed mainly to a marked reduction in pain, as function remained poor and the patients still depended on walking aids. The infection ceased in 92% of the patients with septic prosthesis loosening.

Between 1973 and 1979, ceramic tumor endoprostheses were used in 40 patients treated at the Orthopedic Hospital Wien-Gersthof. The main localization was the proximal humerus, where 25 ceramic endoprostheses were implanted, followed by the proximal femur with ten implants. Elongation of a femoral stump after high amputation was performed in three cases, while in two cases after above-knee amputation and disarticulation of the femur a special disarticulation endoprosthesis was implanted.

The acetabular socket "Model Gersthof" is a spheric polyethylene component which can be anchored cement-free by means of three symmetrically arranged pegs at the outside. Between July 1979 and October 1986, 1316 implants of cement-free sockets were performed at our own department. The evaluation of the socket was based on the criterium of radiological instability (= aseptic loosening). After five years of observation, this design-oriented evaluation of success shows a survival of 92% +/- 2.9%.

Follow-up examinations of 67 implants of cement-free ceramic sockets show the need for an exact definition of failure, to warrant comparable evaluations of results. Statistical survival analysis offers the possibility of presenting both the incidence of failures and the dates of their occurrence. If only revision surgery with removal of the socket is considered to be a failure, our material shows the “survival quota” of the ceramic socket after 8 years to be 96.7% ± 2.2%. If radiological signs of loosening are included in the evaluation of failures, the “survival quota” of the stable implants is reduced to 81.9% ±6.9%.