Dr. Vincent Villa, MD (FMH)

La torsion du squelette se définit comme une déformation de l’os autour de son axe longitudinal ;
ceci est à opposer à la rotation qui représente le mouvement possible de cet os autour de cet axe.
On parlera d’anomalies de torsion lorsque les valeurs mesurées s’écarteront de fac¸on significative des
valeurs moyennes ou lorsqu’un facteur intercurrent viendra modifier de fac¸on anormale la croissance du
membre, ceci de fac¸on symétrique ou asymétrique. Dans le premier cas, l’anomalie de torsion sera isolée
et idiopathique, dans le second cas, on parlera d’anomalie de torsion associée et secondaire.

Abstract

Purpose: When performing total knee arthroplasty (TKA) in valgus knee deformities, a medial or lateral parapatellar approach can be performed, but the lateral approach is often considered technically more difficult. The purpose of this study was to compare intra-operative, early clinical and radiological outcomes of medial and lateral parapatellar approaches for TKA in the setting of moderate knee valgus (<10°).

Methods: We prospectively analysed 424 knees with pre-operative valgus deformity between 3° and 10° that underwent TKA over an 18-year period; 109 were treated with a medial approach and 315 with a lateral approach. Intra- and post-operative outcomes and complication rates after a minimum follow-up of one year were compared.

Results: Tourniquet (p = 0.25) and surgical (p = 0.62) time were similar between groups. The popliteus tendon was released more frequently in the medial-approach group (p = 0.04), while the iliotibial band was released more frequently in the lateral-approach group (p < 0.001). A tibial tuberosity osteotomy was performed more frequently in the lateral- than medial-approach group (p = 0.003). No significant differences in limb alignment (p = 0.78), or Knee Society Score (KSS) knee (p = 0.32) and function (p = 0.47) results were noted based on surgical approach, and complication rates were similar between groups (p = 0.53).

Conclusions: Lateral parapatellar approach is a safe and effective surgical technique for performing TKA in moderately valgus knees. These equivalent early results are encouraging for systematic use of the lateral approach in moderately valgus knees.

Keywords: Lateral approach; Lateral arthrotomy; Tibial tubercle osteotomy; Total knee arthroplasty; Valgus.

Total joint replacement is the standard treatment of advanced osteoarthritis. Metal-on-Metal (MoM) hip resurfacing and hip arthroplasty are associated with long durability and low rates of dislocations and used to be the standard surgical treatments. Complications due to MoM prostheses have however been widely reported [1]. Adverse reactions to metal debris (ARMD) such as metallosis result from the progressive degradation of the metal surface and from metal ions deposition in the surrounding tissues. The formation of “pseudotumors” leading to prosthesis malfunction has been reported after MoM resurfacing. Total arthroplasty can also lead to the infection of the prosthesis as a consequence of contamination during surgery or bacteremic infection not related to the prosthesis. Infections remain quite common (1–3% of surgical procedures) but reports of associated ARMD are limited. We report the case of three patients presenting with metallosis-associated infection on joint prosthesis.