The differential use of anatomic and reversed shoulder prostheses in secondary fracture treatment leads to an improvement in postoperative results. In fracture sequelae types 1 and 2, the anatomic prosthesis is a better choice. However, in fracture sequelae types 3 and 4 with severe deformities, the reversed prosthesis is clearly superior to the anatomic prosthesis.

Accelerated rehabilitation after anterior cruciate ligament (ACL) reconstruction has become increasingly popular. Methods employed include immediate extension of the knee and immediate full weight bearing despite the risks presented by a graft pull-out fixation strength of 200-500 N. The purpose of this study was to calculate the tibiofemoral shear forces and the dynamic stabilising factors at the knee joint for the reasonably demanding task of downhill walking, in order to determine whether or not this task presented a postoperative risk to the patient. Kinematic and kinetic data were collected on six male and six female healthy subjects during downhill walking on a ramp with a 19% gradient. Planar net joint moments and mechanical power at the knee joint were calculated for the sagittal view using a force platform and videographic records together with standard inverse dynamics procedures. A two-dimensional knee joint model was then utilised to calculate the tibiofemoral shear and compressive forces, based on the predictions of joint reaction force and net moment at the knee. Linear envelopes of the electromyographic (EMG) activity recorded from the rectus femoris, gastrocnemius and biceps femoris muscles were also obtained. The maximum tibiofemoral shear force occurred at 20% of stance phase and was, on average, 1.2 times body weight (BW) for male subjects and 1.7 times BW for female subjects. The tibiofemoral compressive force was 7 times BW for males and 8.5 times BW for females during downhill walking. The hamstring muscle showed almost continuous activity throughout the whole of the stance phase.(ABSTRACT TRUNCATED AT 250 WORDS)

In the subtrochanteric region of the femur high tensile forces are active in the lateral cortex and even higher compressive forces in the medial cortex. Subtrochanteric fractures are often comminuted. The implant of choice for osteosynthesis of subtrochanteric femoral fractures is the condylar plate. Usually the various fragments are dissected intraoperatively and the medial cortex is reconstructed anatomically for improved abutment. This devitalizing of fragments leads to disturbed healing, so that failure are frequent despite cancellous bone grafting. The osteosynthesis technique introduced by Mast and Ganz of indirect reduction by distractor without dissection of the fragments and the medial cortex allowed the complication rate to be reduced to 0%. We have modified this technique in that we performed closed reduction on the traction table rather than using the distractor to achieve axial and rotational alignment, after which the fracture is stabilized with dynamic condylar screw (DCS) under image intensifier control. The proximal femur is dissected only laterally and only in so far as in necessary to place the DCS. We never use cancellous bone grafting. From 1988 to 1990 this technique was used in 12 patients. All fractures had healed uneventfully after 4 months.

A 59-year-old woman with calcific tendinitis in her right shoulder underwent extracorporeal shock-wave lithotripsy. Three years and four months later she presented with osteonecrosis of the head of the right humerus. It is known that shock waves in patients with urological disorders can damage blood vessels. A possible reason for the development of osteonecrosis in this patient may have been damage to the blood supply of the head of the humerus.

After sacrectomy, mobilization of the patient is only possible if a stable connection between the spine and pelvis can be obtained. We have developed an instrumentation to fix the pelvis to the spine. Two DHS screws connected to each other were implanted in the pelvis (one DHS screw into each ilium). An internal spine fixator, anchored in L3 and L4 through transpedicular Schanz screws, was attached to these DHS screws. Two patients were stabilized with this implant after sacrectomy. One patient was able to walk with crutches; the other patient was able to walk even without crutches.