Relevancia del equilibrio de los ligamentos colaterales de la rodilla en la artroplastia de rodilla navegadaestudio anatomo-clinico y dinamico-funcional de los mismos

Abstract

Introduction: Total knee arthroplasty obtains a pain relief and a very good patient ́s recovery after a surgery of the knee, with a survivorship of 99% in the next 12 years after surgery.Instability and disalignment decisively influences in prosthetic failure, therefore, the correct balance of the collateral ligaments, during the surgical procedure is essential to avoid aseptic loosening of the implant.The topic on the choice whether or not to retain the posterior cruciate ligament is still alive. On 1980s, some radiographic image and techniques to quantify the mobility of the knee in real time have been used. These studies have demonstrated how the prosthesis moves in real time. Changes in joint line height in more than 4mm., is a real disadvantage and a instability pattern of total knee replacement. Some patients still have difficult explanation pain, allergic antecedents or even an infection which may be the explanation. Material and method:. We carried out a retrospective longitudinal analytical study, with a cohort of 92 knees of TKA , from January 2012 to January 2019. They were operated surgically by a total knee replacement with the navigated system of OrthoPilot® de BBraun®, with a minimal outcome of 18 months after surgery. Results: Among 92 evaluable patients, 29 were men. Forty-one patients surgically operated a right knee surgery. The age of patients was 68,04.The average weight was 78,3. The average height was 160 . Eighty-five patients were diagnosed with primary gonarthrosis. Using the Ahlbäck classification, 29 patients had a degree four, while 63 patients showed a grade five(maximum). The radiographic axis in varus, was in 72 patients 6.2º. In 13 patients , the valgus anatomic axis average was of 5.13º .The average flexion range among the 145 patients was 110º Forty four (48.27%) patients showed in average a flexion contracture in the knee joint of 6º.Surgical time average was 55 minutes. The average cut value of the medial tibial plateau was 4.3mm . The cut value of the lateral tibial plateau was 7,72mm. The cut value of the condyle of medial femur was 9,4 mm ,cut value of the condyle of lateral femur was 9,22 mm. The average hospital stay time was of 3.25.The pain VAS at the pre-operative consultation was significantly decreased between 8, at the 24-month postoperative consultation, the average score was 2. This reduction on pain VAS was 6. At the preoperative consultation ,40 patients showed a flexion contracture of 4.6º.At the 24-month postoperative consultation, 50 patients had reduced the flexion contracture. Puntuation of the Oxford Scale Score on the preoperative showed an average promethium of 49.91, at 24 post-chirurgical months value was 16.54). Reduction of the score was 32 points .The score for the fifth question in the Oxford Scale in the pre-chirurgical consultation shows medium value of 4 (unbearable pain) In the consultation of 24 months post-chirurgical, value of the fifth question was 1.4 .The reduction in the medial score was 2.6. Conclusión: It was proved that using surgical navigation increases stability and optimal implant placement, improve the right balance of the soft tissue, and it is the best accuracy of the level of articular line (Range between +/-3 mm). A statistically significant reduction in the number of flexion contraction patients was verified, achieving full extension. A strong correlation was found between the range of post-surgical mobility and the variation of the joint line. Maintaining the articular line in normal parameters, between +/-1, decreases the degree of contracture in flexion, and therefore, it improves the clinical results.