Abstract

ALMEIDA, Richard P et al. Narrative review of the valgus knee in primary total joint arthroplasty. SA orthop. j. [online]. 2024, vol.23, n.1, pp.43-49. ISSN 2309-8309.  http://dx.doi.org/10.17159/2309-8309/2024/v23n1a7.

The valgus knee is less common than the neutral or varus aligned knees in primary total knee arthroplasty (TKA). TKA is technically more challenging in the valgus knee because of the relative difficulty of restoring the joint line, correcting limb alignment, ensuring stability and correcting patellofemoral tracking. Consequently, TKA outcomes are poorer in the valgus knee. The valgus deformity may be intra- or extra-articular or a combination of both, with bony and soft tissue changes resulting in alteration of the rotational profile of the lower limb. Bony changes in the femur include hypoplasia of the distal femur lateral condyle and erosion of the posterior aspect of the lateral condyle. Bony changes in the tibia include remodelling of the lateral tibia plateau and metaphyseal bone. Soft tissue structures on the lateral aspect of the knee may be contracted or tightened with attenuation of the medial stabilising structures. These features contribute to a change in the rotational profile of the knee resulting in external rotation of the tibia and lateral subluxation of the patella with maltracking. Clinical examination should be thorough in both standing and supine positions and must the include the foot and ankle as hindfoot alignment affects the mechanical axis of the weight-bearing lower limb. Neurovascular assessment of the limb should document peroneal nerve integrity as this nerve is at risk of damage at the time of deformity correction. Radiological assessment should, ideally, include long limb weight-bearing views in multiple planes. Computer tomography scanning may be appropriate in cases of severe bony deformities or poorly appreciated anatomical landmarks on standard radiographs. This review delves into the various classification systems for valgus knees and finally, focuses on surgical approaches, appropriate implant choices and technological advancements in the management of the valgus knee. A clear understanding of the pathoanotomy of the valgus knee together with a thorough clinical assessment and appropriate use of technology should help improve outcomes of TKA in the valgus knee. Level of evidence: Level 5

Keywords : knee; arthroplasty; valgus; replacement; technique.

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