Optimized functional femoral rotation in navigated total knee arthroplasty considering ligament tension.

Femoral malrotation in total knee arthroplasty is correlated to an increased number of revisions. Anatomic landmarks such as Whiteside line, posterior condyle axis and transepicondylar axis are used for determining femoral component rotation. The femoral rotation achieved with the anatomical landmarks is compared to the femoral rotation achieved by a navigated ligament tension-based tibia-first technique. Ninety-three consecutive patients with gonarthritis were prospectively enrolled. Intraoperatively the anatomical landmarks for femoral rotation and the achieved femoral rotation using a navigated tension-based tibia-first technique were determined and stored for further comparison. A pre- and postoperative functional diagram displaying the extension and flexion and varus or valgus positions was also part of the evaluation. Using anatomical landmarks the rotational errors ranged from 12.2° of internal rotation to 15.5° of external rotation from parallel to the tibial resection surface at 90° flexion. A statistical significant improved femoral rotation was achieved using the ligament tension-based method with a rotational error ranged from 3.0° of internal rotation to 2.4° of external rotation. The functional analyses demonstrated statistical significant lower varus/valgus deviations within the flexion range and an improved maximum varus deviation at 90° flexion using the ligament tension-based method. Compared to the anatomical landmarks a balanced, almost parallel flexion gap was achieved using a navigation technique taking the ligament tension of the knee joint into account. As a result the improved femoral rotation was demonstrated by the functional evaluation. Unilateral overloading of the polyethylene inlay and unilateral instability can thus be avoided.

Closed reduction and percutaneous Kirschner wire fixation for the treatment of dislocated calcaneal fractures: surgical technique, complications, clinical and radiological results after 2-10 years.

INTRODUCTION: To reduce complications, a minimally invasive technique for the treatment of dislocated intraarticular fractures of the calcaneus was used. Therefore previously described closed reduction and internal fixation techniques were combined and modified. MATERIALS AND METHODS: Sixty-seven out of 92 calcaneal fractures could be retrospectively evaluated with an average follow-up time of 5.7 years (minimum 2-10 years follow-up). For radiographic evaluation, plain radiographs and CT scans were obtained. The Zwipp score was used for clinical evaluation. Sanders type II, III and IV fractures were diagnosed. RESULTS: Length of surgery averaged 61 min (range 20-175 min). The incidence of subtalar arthritis was correlated to the severity of fracture. Böhler's angle was restored in 70.1% (47 of 67) of the cases. On the last follow-up evaluation the average Zwipp score was 130 points (range 48-186 points). The majority (77.7%) of patients were content with their treatment result. The rate of significant complications was 6.5%. DISCUSSION: Compared to open techniques the presented minimally invasive technique showed comparable results with a low rate of serious complications and is a viable alternative for the treatment of intraarticular, dislocated calcaneal fractures.

[Luxations and luxation fractures of the carpometakarpal joints IV and V (author's transl)]. / Luxationen und Luxationsfrakturen der Karpometakarpalgelenke von Ring- und Kleinfingerstrahl.

Luxations and luxations fractures of the carpometacarpal joints are rare, with the exception of the thumb. Basing on the case histories of 3 patients treated by the authors, these injuries are described and discussed.

[The trapezium bone--anatomy, radiography and traumatology]. / Das Trapezium - Anatomie, Röntgenologie und Traumatologie.

Due to the functional peculiarities of the thumb, fractures of the trapezium are of importance, though being rather rare. Difficulties are often encountered with radiological demonstration and anatomical correlation of findings in this area. The article gives an anatomical-radiological correlation and points out aspects of traumatology.

[Stepwise reconstruction in mid-hand destruction by crush]. / Schrittweise Rekonstruktion bei Mittelhandzerstörung durch Quetschung.

The treatment of very serious crush injuries of the metacarpus is reported in three examples. It is recommended that in such injuries reconstruction of all damaged structures should not be performed in the first operation. The most important step beside the stabilisation of the skeleton is microsurgical revascularisation.. The reconstruction of nerves and tendons should be limited during the primary operation. Secondary reconstruction then has a lower risk and gives a good functional result. In such trauma the use of distant flaps for the reconstruction of large soft tissue defects seems more advantageous than the transplantation of free flaps by microvascular anastomoses.