Acta orthopaedica Scandinavica. Supplementum最新文献

Particulate wear debris in totally replaced hips causes adverse local host reactions. The extreme form of such a reaction, aggressive granulomatosis, was found to be a distinct condition and different from simple aseptic loosening. Reactive and adaptive tissues around the totally replaced hip were made of proliferation of local fibroblast like cells and activated macrophages. Methylmethacrylate and high-molecular-weight polyethylene were shown to be essentially immunologically inert implant materials, but in small particulate form functioned as cellular irritants initiating local biological reactions leading to loosening of the implants. Chromium-cobalt-molybdenum is the most popular metallic implant material; it is hard and tough, and the bearings of this metal are partially self-polishing. In total hip implants, prerequisites for longevity of the replaced hip are good biocompatibility of the materials and sufficient tribological properties of the bearings. The third key issue is that the bearing must minimize frictional shear at the prosthetic bone-implant interface to be compatible with long-term survival. Some of the approaches to meet these demands are alumina-on-alumina and metal-on-metal designs, as well as the use of highly crosslinked polyethylene for the acetabular component. In order to avoid the wear-based deleterious properties of the conventional total hip prosthesis materials or coatings, the present work included biological and tribological testing of amorphous diamond. Previous experiments had demonstrated that a high adhesion of tetrahedral amorphous carbon coatings to a substrate can be achieved by using mixing layers or interlayers. Amorphous diamond was found to be biologically inert, and simulator testing indicated excellent wear properties for conventional total hip prostheses, in which either the ball or both bearing surfaces were coated with hydrogen-free tetrahedral amorphous diamond films. Simulator testing with such total hip prostheses showed no measurable wear or detectable delamination after 15,000,000 test cycles corresponding to 15 years of clinical use. The present work clearly shows that wear is one of the basic problems with totally replaced hips. Diamond coating of the bearing surfaces appears to be an attractive solution to improve longevity of the totally replaced hip.

The worldwide increase in hip fractures is a major challenge to the health care system and society. The proper treatment of femoral neck fractures in the elderly is still controversial, and even more so from an international perspective. Optimising the treatment for improved outcomes and a reduced need for secondary surgery is mandatory for humanitarian and economical reasons. The importance of incorporating the patient's perspective of the outcome in clinical trials has been acknowledged and there are now numerous instruments for assessing the quality of life. We evaluated two quality of life instruments, the EQ-5D and the SF-36, in patients with femoral neck fractures and also measured the quality of life two years after different interventions. The EQ-5D was validated in two prospective studies and it appeared to be an appropriate quality of life instrument in elderly patients with femoral neck fractures. There was a good correlation between the quality of life (EQ-5Dindexscores) and other outcome measures such as pain, mobility and independence in activities of daily living (ADL). The results also showed high responsiveness, i.e., ability to capture clinically important changes, for both the EQ-5D and the SF-36. The questionnaire response rate for both instruments was high. The rated prefracture EQ-5Dindexscores showed good correspondence with the scores of an age-matched Swedish reference population. The quality of life in patients with femoral neck fractures treated with internal fixation (IF) decreased, particularly in patients with fracture healing complications. The fracture healing complications rate at two years in patients with displaced femoral neck fractures treated with IF was 36% compared with 7% in patients with undisplaced fractures. The quality of life of patients with uneventfully healed fractures at two year was lower in patients with primary displaced fractures than in patients with primary undisplaced fractures. In a prospective randomised trial, patients with displaced femoral neck fractures were randomised to IF or total hip replacement (THR). IF resulted in more complications than THR, 36% versus 4%, and necessitated more reoperations, 42% versus 4%. Hip function and quality of life (EQ-5D) were generally better in the THR group. In summary, THR yielded a better outcome than IF for an elderly, relatively healthy, lucid patient with a displaced femoral neck fracture. In a study of elderly women with femoral neck fractures, nearly half of the patients displayed signs of protein-energy malnutrition. Underweight was associated with muscle fatigue, cognitive dysfunction and a low quality of life (Nottingham Health Profile). In a prospective randomised trial, protein-rich liquid supplementation in combination with an anabolic steroid given for 6 months to lean elderly women after a femoral neck fracture was shown to positively affect lean body mass, ADL and quality of life (EQ-5D). Fracture healing complications had a ne

It has been generally accepted that residual cartilage and subchondral bone has to be removed in order to get bony fusion in arthrodeses. In 1998 we reported successful fusion of 11 rheumatoid ankles, all treated with percutaneous fixation only. In at least one of these ankle joint there was cartilage left. This was confirmed by arthrotomy in order to remove an osteophyte, which hindered dorsiflexion. More than 25 rheumatoid patients with functional alignment in the ankle joint have subsequently been operated on with the percutaneous technique, and so far we have had only one failure. Patients with rheumatoid arthritis are known to sometimes fuse at least their subtalar joints spontaneously, and the destructive effect of the synovitis on the cartilage could contribute to fusion when using the percutaneous technique. In a rabbit study we therefore tested the hypothesis that even a normal joint can fuse merely by percutaneous fixation. The patella was fixated to the femur with lag screw technique without removal of cartilage, and in 5 of 6 arthrodeses with stable fixation bony fusion followed. Depletion of synovial fluid seemed to be the mechanism behind cartilage disappearance. The stability of the fixation achieved at arthrodesis surgery is an important factor in determining success or failure. Dowel arthrodesis without additional fixation proved to be deleterious. A good fit of the bone surfaces appears necessary. In the ankle joint, it would be technically demanding to retain the arch-shaped geometry of the joint after resection of the cartilage. Normally the joint surfaces are resected to produce flat osteotomy surfaces that are thus easier to fit together, encouraging healing to occur. On the other hand it is considered an advantage to preserve as much subchondral bone as possible, as the strong subchondral bone plate can contribute to the stability of the arthrodesis. Ankle arthrodesis can be successfully performed in patients with rheumatoid arthritis by percutaneous screw fixation without resection of the joint surfaces. This procedure has two advantages: first, it is less surgically traumatic, second, both the arch-shaped geometry and the subchondral bone are preserved, and thus both could contribute to the postoperative stability of the construct. Intuitively, preservation of the arch-shape should increase rotational stability. The results of our experimental sawbone study indicate that the arch shape and the subchondral bone should be preserved when ankle arthrodesis is performed. The importance of this is likely to increase in weak rheumatoid bone. In a finite element study the initial stability provided by two different methods of joint preparation and different screw configurations in ankle arthrodesis, was compared. Better initial stability is predicted for ankle arthrodesis when joint contours are preserved rather than resected. Overall, inserting the two screws at a 30-degree angle with respect to the long axis of the tibia