No abstract

Carpometacarpal dislocations are rare. In most cases, the dislocation is caused by a violent injury, e.g. the crash of a motorcyclist or a fall from great height. A considerable swelling of the back of the hand may mask the characteristic lump at the root of the hand. The diagnosis can be easily missed due to serious associated injuries. The lesion is also often overlooked in the routine X-ray diagnostic. Lateral and oblique views are important for the recognition of the true extent of the lesion. Anatomical reposition is difficult if the dislocation is not fresh and open reposition is necessary. Between 1990 and 1999, altogether 16 patients who had suffered a carpometacarpal dislocation were treated. One patient had a rare dislocation of the III. to V. joints. Simultaneous dislocation of all five carpometacarpal joints was seen in three cases. The treatment mostly consists of closed reduction and temporary Kirschner wire transfixation. Fourteen patients were controlled (clinical examination and X-ray control) after an average follow-up time of three years. In addition, the DASH questionnaire was used. After an average time of 3 years the patients showed in 64% of the cases excellent and good results (eight excellent, one good). The subjective function of the hand was moderate in 29% (four patients), in one patient the subjective function was poor (7%). Five patients had a diminished range of motion of the hand. The average points in the DASH questionnaire were 24. We recommend as therapy of choice after primary closed repositioning, primary surgery by means of short Kirschner wires introduced from distal-dorsal to proximal-palmar. In cases of impossible closed reduction or in cases with local additional injuries, open treatment for fixation, is indicated.

The mineral content of 42 normal and 19 vertebrae with metastases obtained at postmortem was determined by a dual energy method and this was related to their ability to fracture. In the normal vertebrae, this relationship was expressed in the form of a logarithmic function. Amongst vertebrae with osteolytic lesions, liability to fracture increased more rapidly than mineral loss. Vertebrae with osteoblastic metastases showed increased mineral concentration with an increased liability to fracture as compared with normal vertebrae.

The main problem in the treatment of orthopaedic joint-surface defects will be solved by tissue engineering of cartilage implants. Entire biological osteochondral implants can be grown from autologous cells of the patient. The nutrition of articular cartilage is by diffusion only. Therefore the chondrocyte as the unique cell type is perfectly dedicated to the tissue culture approach. Engineering techniques of bioreactors are prerequisite for these biological and medical solutions. With our tissue engineering project for the generation of osteochondral constructs we demonstrate possibilities and characteristics of bioreactors for the modification of cell culture techniques and mechanical conditioning of cartilage tissue for fully operable implants.

The most serious complication of accident surgery is postoperative osteitis. At the same time, perioperative antibiotic prophylaxis is generally recommended in order to reduce the rate of infection in joint surgery. The criteria for the suitability of a substance as prophylaxis include inter alia the activity spectrum with respect to the expected microorganisms, its retention time in the body and its ability to penetrate the endangered tissue. In the present study, the systemic and local activity levels after a single i.v. dose of 1500 mg cefuroxime was investigated in relation to the time of administration in 30 patients who had to undergo total hip replacement owing to a medial fracture of the neck of the femur. The tissue and serum samples were analyzed by high pressure liquid chromatography (HPLC). The results show that the tissue levels of the intermediary cephalosporin after an i.v. single shot dose are on average still several times higher than the minimum inhibitory concentration (MIC) of the most frequent bacterium. Staphylococcus aureus, as late as 4 hours after application. The optimal time for the administration form selected was immediately prior to the operation and the concentrations measured suggest that several repeat doses of cefuroxime for short-term prophylaxis are not necessary.