**1. Introduction**

Angular deformities around the knee joint necessitate special consideration to restore normal alignment during total knee arthroplasty (TKA). In the region of 10–15% of patients requiring a primary TKA present with a valgus deformity (VD), the accurate correction of which still poses a challenge [1]. Excessive preoperative malalignment predisposes to a greater risk of failure compared to well-aligned knees [2]. For this reason, the restoration of

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

the normal mechanical axis of the knee and the balance of the surrounding soft tissues have to be observed to be important for the final outcome of knee replacement operations [2–5]. Thus, the severely valgus deformed knees are associated with a worse outcome when compared with their varus counterparts [5].

**2. Clinical examination and preoperating planning**

erating planning.

the patient.

**2.1. Knee physical examination**

**Figure 1.** Valgus left knee in standing position.

Total knee arthroplasty (TKA) with valgus release is indicated when both mechanical and pharmacological nonoperative treatment modalities for end-stage degenerative joint disease have failed to relieve pain. The major contraindication to TKA is infection, and relative contraindications include young age, high activity level, and obesity [18]. Clinical evaluation and radiological assessment are extremely important as part of the TKA preop-

Primary Total Knee Arthroplasty in Valgus Deformity http://dx.doi.org/10.5772/intechopen.74114 57

Patients with end-stage degenerative joint disease and valgus knee deformity have significant pain, limitation of daily living activities, increasing angular deformity, and increasing instability. In mild to severe VD, there is important ROM limitation, and in many cases night pain awakes

During standard physical examination for end-stage degenerative knee disease, the orthopedic physician should assess the patient's overall alignment both in the supine and weight-bearing positions, and the gait should be observed, in order to identify other dynamic instabilities (**Figure 1**). Both sagittal deformity (as fixed flexion contracture or recurvatum) and rotational deformity must be attended. Furthermore, the knee range of motion should be measured; the

The etiologic parameters of knee VD are different and multifactorial from congenital to secondary such as primary osteoarthritis. More specifically, inflammatory arthritis (rheumatic diseases), primary osteoarthritis, posttraumatic arthritis (as a result of a tibial malunion, physeal arrest, or tibial plateau fracture), or overcorrection from a high tibial osteotomy for a preexisting varus deformity are the main etiologies in adults with [2, 6]. However, a significant percentage of adults with lateral compartment arthritis and concomitant VD represents unresolved physiologic valgus deformed knees. Infrequently, persistence of genu valgus from childhood may exist secondary to metabolic disorders, such as rickets and renal osteodystrophy [7]. Overwhelmingly, the most common etiology of VD knees is primary osteoarthritis and secondly rheumatoid arthritis and posttraumatic arthritis, whereas other inflammatory disorders and osteonecrosis are scarce etiologies based on the main clinical series that utilized TKA in the last two decades [1–5, 8–16].

The valgus deformity is sustained by anatomical variations divided into bone remodeling and soft tissue contraction/elongation, and usually it is a combination of primary or secondary bone and soft-tissue abnormalities. These include contracted lateral capsular and ligamentous structures, lax medial structures, and acquired or preexisting bony anatomic deficiencies. This constellation of pathology makes attaining soft-tissue balance when the knee is returned to physiologic alignment extremely difficult [2, 4, 6]. More specifically, the contracted structures are the iliotibial band (ITB), the lateral collateral ligament (LCL), the popliteus tendon, and the posterolateral capsule (PLC). Rarely, the lateral head of the gastrocnemius and the long head of the biceps femoris are affected. Some authors also further described a posterior cruciate ligament (PCL) alteration in valgus knees, but in the literature its influence in maintaining the deformity is not universally accepted [2]. The stabilizing structures on the medial side of the knee are attenuated. Unlike its varus counterpart, bone tissue variations consist of lateral cartilage erosion, lateral condylar hypoplasia and metaphyseal femur remodeling, while the tibial plateau is usually less affected [2, 3, 8–10]. The described deformities can lead to a tibial external rotation and to a patellar lateral subluxation tendency [11].

In 2005, Ranawat described three grades of VD [1]. More specifically, in Grade-I (80%), the deformity is less than 10° and is passively correctable, whereas it is characterized by an intact medial collateral ligament (MCL). In Grade-II (15%), the axis deviation ranges between 10° and 20°, whereas the MCL is elongated but functional; and in Grade-III (5%), the axis deviation is more than 20°. All the medial stabilizing elements are typically not functional so a constrained implant usually is required [1, 10].

Understanding the specific pathologic anatomic changes associated with the valgus knee is a prerequisite so as to select the proper surgical method, to optimize component position and restore soft-tissue and gap balance [17]. Over the last 20 years, numerous approaches and soft-tissue procedures have been proposed to perform TKA in VD with the purpose to restore and maintain the limb's anatomical axis. In this chapter, we overview the most common approaches, we analyze the different techniques of succeeding anatomical axis restoration and soft tissue and gap balance, and lastly we present the literature up-to-date long-term results.
