[Supracondylar femur osteotomies around the knee. Patient selection, planning, operative techniques, stability of fixation, and bone healing]. / Suprakondyläre Femurosteotomien in Kniegelenknähe. Patientenauswahl, Planung, Operationstechniken, Fixationsstabilität und Knochenheilung.

BACKGROUND: Similar to the reappreciation of high tibial osteotomy (HTO), supracondylar distal femur varus osteotomy (SCO) for lateral compartment osteoarthritis (OA) of the knee has gained renewed interest as new knowledge has become available on the influence of malalignment on the development, progression and symptoms of OA. Furthermore, the less than optimal results of total knee replacement (TKR) in younger patients have also led to renewed interest in joint-preserving treatment options. PURPOSE: Varus SCO has not had the same success or widespread use as valgus HTO. The goal in SCO is similar to HTO, to shift the load from the diseased to the healthy ompartment, in order to reduce pain, improve function and delay placement of a TKR. Valgus OA however occurs much less frequently than varus OA and varus SCO is considered a technically more demanding procedure. In the past the surgical techniques for SCO were mainly dependent on difficult-to-use implants making the procedure more complex. Complication rates related to the failure of fixation up to 16 % have been reported. DISUSSION: The new biplane osteotomy technique fixated with a locking compression plate is very stable; bone healing potential is optimal using this technique and takes 6-8 weeks. Full weight bearing before full bone healing is possible without loss of correction. CONCLUSION: In this article patient selection, planning, surgical techniques, stability of fixation and bone healing for SCO are discussed. In the past the surgical techniques for SCO were mainly dependent on difficult to use implants making the procedure more complex. Complication rates related to the failure of fixation of up to 16 % have been reported.

Axial and torsional stability of an improved single-plane and a new bi-plane osteotomy technique for supracondylar femur osteotomies.

PURPOSE: An important disadvantage of the standard medial closing-wedge distal femur osteotomy for lateral compartment osteoarthritis of the knee is the immediate effects on the extensor mechanism function. Therefore, a novel bi-plane osteotomy technique was developed. The stability and stiffness of this newly developed technique and a modification of the proximal screw configuration were tested in a composite femur model and compared to the standard single-plane technique. Research question was if the new bi-plane technique and/or modified screw configuration would improve the stability and stiffness of the construct. METHODS: In 12 femurs, motion at the osteotomy under axial and torsion loading was measured using a 3D motion analysis system. All were subsequently tested to failure. The data recorded were used to calculate stability and stiffness of the constructs. RESULTS: The stability and stiffness were highest in the bi-plane technique under axial loads, but were lower under torsional loading, compared to the single-plane technique. The screw configuration modification improved axial stability and stiffness, but had no influence on torsional stability. CONCLUSION: In replicate femurs, the new bi-plane technique improved axial stability, but in contrast to what was theorized, decreased torsional stability, compared to the single-plane technique. The addition of a bi-cortical screw proximally improved stability under axial loading, but not torsion. Further clinical testing will have to prove if early full weight bearing using the new bi-plane technique is possible.

Osteotomies around the knee: patient selection, stability of fixation and bone healing in high tibial osteotomies.

New developments in osteotomy techniques and methods of fixation have caused a revival of interest of osteotomies around the knee. The current consensus on the indications, patient selection and the factors influencing the outcome after high tibial osteotomy is presented. This paper highlights recent research aimed at joint pressure redistribution, fixation stability and bone healing that has led to improved surgical techniques and a decrease of post-operative time to full weight-bearing.

[Differential diagnosis and therapy of multi-fragment humeral head fracture--an analysis of three clinical studies]. / Differentialdiagnostik und -therapie der mehrfragmentären Humeruskopffraktur--eine Analyse aus drei klinischen Studien.

Out of the total number of patients of three Centers for Orthopaedic and Trauma Surgery, 93 comminuted humeral head fractures were clinically and radiologically controlled by means of a retrospective analysis. The classification of the fractures was made according to C.S. Neer, the clinical evaluation according to the Constant-Score. The analysis of the results in relation to the respective therapeutic methods revealed fundamental differences between the various types of fractures depending on the number of fragments. The prognosis of the three-part fractures appears essentially determined by the biomechanical conditions. This means that the therapeutic method has to be applied according to the restitution of the respective position of the fragments. Open reduction and internal fixation (mean Constant-Score 83 resp 91 points) or conservative treatment (78 points) seem to be primarily indicated in these cases. The prognosis of the four-part fractures, on the contrary, is largely determined by the problems of vascular supply of the head fragment, with a high risk of a humeral head necrosis. For this reason a primary prosthetic replacement (mean Constant-Score in case of primary implantation 75 points, compared with 54 points in case of conservative treatment and 52 points for open reduction and internal fixation), should be recommended for this type of fracture. For therapeutic and prognostic reasons, fractures at the proximal end of the humerus require an exact classification on the radiological basis of at least a so-called "trauma series". However, for a more accurate visualisation especially of the region of the lesser tuberosity (which is difficult to assess by means of conventional radiology), and consequently for the precise determination of the number of fracture-parts and their respective positions, we consider a CT Scan to be compulsory.