Arthroscopic reconstruction of the popliteus complex: accuracy and reproducibility of a new surgical technique.

PURPOSE: With combined PCL reconstruction and a minimal invasive (extra-anatomical) Larson's procedure, dorsal instability can be reduced by about 50-70 %. Better results are described by open and more anatomical procedures. In this study, a new, standardized, arthroscopic technique for anatomical popliteus tendon (PLT) reconstruction is evaluated. METHODS: In 13 cadaver knees, an arthroscopic reconstruction of the PLT and the lateral collateral ligament was performed. Twelve defined landmarks were used for arthroscopic tunnel placement, and the distance of the tunnel locations to these specific landmarks was evaluated. RESULTS: The femoral drill channel was located with a high degree of accuracy and reproducibility in the centre of the femoral footprint of the PLT (on average 1.1 (±1.6) mm distal from the centre). On the tibial side, the drill channel was in the distal third of the sulcus popliteus in all cases. On average, the channel was placed exactly at the level of the tip of the fibula (±1.5 mm) and 0.6 (±1.7) mm medially from the medial edge of the fibula. The centre of the channel was 13.4 (±2.3) mm distal from the joint line. CONCLUSIONS: The presented arthroscopic technique for PLT reconstruction is standardized, reproducible and has a high accuracy for the placement of the tibial and femoral tunnel. The technique could be clinically relevant for future arthroscopic posterolateral corner reconstructions. LEVEL OF EVIDENCE: III.

Fate of large donor site defects in osteochondral transfer procedures in the knee joint with and without TruFit plugs.

INTRODUCTION: Because of the potential donor site morbidity, cartilage lesions of more than 3 cm(2) in size are considered to be critical regarding autologous osteochondral transplantation (OCT). In this study, the potential donor site morbidity for large defects should be reduced by means of OBI TruFit Plugs. MATERIALS AND METHODS: An autologous OCT was carried out on 37 patients and the cylinders were received from the dorsal medial femoral condyle. The donor site defects of 21 patients (average defect size 5.5 cm(2)) were filled with artificial TruFit cylinders (study group); the donor site defects (average defect size 4.6 cm(2)) were left untreated for 16 patients. RESULTS: In the study group, the Tegner, Western Ontario and McMaster Universities (WOMAC), knee society score, and visual analogue scale pain scores improved from preoperatively 3.2 (±0.8), 60.9 (±41.6), 133.6 (±27.1), and 4.8 (±2.3) points, respectively, to 3.9 (±0.6), 35.5 (±27.1), 177.8 (±16.6), and 3.3 (±2.9) points, respectively, at the time of the second follow-up; the control group's preoperative score values came to 2.8 (±0.9), 73.3 (±50.2), 123.8 (±41.5), and 5.3 (±2.7) points, respectively, and changed to 3.6 (±0.8), 41.4 (±28.8), 179.3 (±17.5), and 3.1 (±2.0) points, respectively, at the time of the second follow-up. The smaller the initial chondral defect was in the study group, the better the WOMAC score values became (p < 0.05). The modified Henderson score at the study group's donor sites improved from 19.2 (±3.3) to 13.7 (±2.1) points (p < 0.001); the control group's score values for the donor sites were 18.3 (±3.4) and 15.4 (±4.4) points (p = 0.0015). CONCLUSIONS: OCT is an effective therapy even for large chondral defects >3 cm(2). By filling the defects with TruFit implants, no clinical improvements could be found since the donor site morbidity was already low anyway. However, the regeneration of defects filled with TruFit implants took more than 2 years.

Ulnar head replacement and related biomechanics.

A stable distal radioulnar joint (DRUJ) is mandatory for the function and load transmission in the wrist and forearm. Resectional salvage procedures such as the Darrach procedure, Bowers arthroplasty, and Sauvé-Kapandji procedure include the potential risk of radioulnar instability and impingement, which can lead to pain and weakness. Soft tissue stabilizing techniques have only limited success rates in solving these problems. In an attempt to stabilize the distal forearm mechanically following ulnar head resection, various endoprostheses have been developed to replace the ulnar head. The prostheses can be used for secondary treatment of failed ulnar head resection, but they can also achieve good results in the primary treatment of osteoarthritis of the DRUJ. Our experience consists of twenty-five patients (follow-up 30 months) with DRUJ osteoarthritis who were treated with an ulnar head prosthesis, with improvement in pain, range of motion, and grip strength. An ulnar head prosthesis should be considered as a treatment option for a painful DRUJ.