**2.3. Templating**

extensor mechanism status and the patellofemoral joint should be evaluated and measured

In addition, preoperative clinical examination plays a major role for the orthopedic surgeon to determine whether the deformity is fixed, correctable or unstable. The knee should be further evaluated for anteroposterior laxity, coronal and sagittal deformity, and mediolateral instability [3]. It is very crucial to assess if VD is fixed (Ranawat Grade III) or still reducible (Ranawate Grade II or I). In fixed deformity, the lateral structures are tight and in contrast the medial ligaments are partially continent. As a consequence, in these deformities, when the lateral soft tissue release is fulfilled, the remaining laxity requires the usage of constrained prosthesis. In contrast, in a reducible deformity, soft tissue release is less invasive, and a standard unconstrained prosthesis could be used. The orthopedic surgeon would lastly perform a neurovascular examination to differentiate a possible lumbosacral or vascular disease [2, 9–11].

After the clinical assessment, the mandatory preoperative planning radiographs of three classic views of the affected knee are: standing anteroposterior, lateral (profile), and sunrise (**Figure 2**). The limb axis deviation measurement with long film standing views or CT-scan with anterior

**Figure 2.** Anteroposterior X-ray in standing position for measuring valgus deviation.

[2, 6, 11].

58 Primary Total Knee Arthroplasty

**2.2. Radiographic evaluation**

In the radiographic weight-bearing anteroposterior view of the knee, a template of bone cuts should be performed in consideration with the prosthesis type and design that will be implanted in the candidate for TKA. Two lines are drawn: one line on the tibial anatomical axis and afterward a perpendicular one at the level of the lateral tibial plateau. In that way, the surgeon will have an indication for the tibial resection [2, 4]. Firstly, the femoral anatomical axis is drawn and secondly the line with the desired amount of remaining valgus (usually 3°) at the level of the intercondylar notch [4]. The orthopedic surgeon should also observe the

**Figure 3.** Anteroposterior X-rays in standing position of Valgus knees in different grades.

posterior capsule's presence of osteophytes, on the knee X-ray lateral view. Lastly, the lateral view can be further used for sizing the femoral component and for locating the entry point of the femoral canal [1, 11, 17].

[4, 6]. Nevertheless, if press-fit femoral component is being performed, then as long as native bone is resting on the medial-posterior side of the chamfer cuts, then the remaining lateral defect can be filled with autograft bone taken from other cuts during the procedure [1, 6].

Primary Total Knee Arthroplasty in Valgus Deformity http://dx.doi.org/10.5772/intechopen.74114 61

In order to understand and perform the valgus knee operative procedure, the orthopedic surgeons should consider that the lateral stabilizers are of two types: (1) the lateral collateral ligament (LCL) and the popliteal tendon who insert near the flexion-extension axis and act in both knee extension and flexion and (2) the fascia lata, the posterolateral articular capsule (PLC), the biceps and the external gastrocnemius muscles who insert remotely with respect to

Many and various protocols of progressive step-wise release have been proposed during the last two decades, and as a consequence, the sequence of the lateral release remains controversial. In 2003, the SOO (*Societe d'Orthopedie de l'Ouest*—Western France Orthopedics) Society presented a classification system of four types of valgus knee, with increasing surgical difficulty to be distinguished from Type I to IV. More specifically, in Type I valgus knees, the deformity can be completely reduced, without medial laxity, and with no particular problems whereas a medial approach is possible. In case of course of patellar dislocation, a lateral approach is recommended. In Type II valgus knees, the deformity is totally or partially irreducible, nonetheless without medial laxity, and is the most frequent; and lateral release is required. In Type III, the deformity is reducible, but with medial distension laxity, and then the medial laxity should be managed. Lastly, in Type IV, the deformity is irreducible, with

Keblish [11] was the first, in 1991, to recommend a lateral capsular approach for TKA in the valgus knee, and the technique was refined by Buechel [25]. It has been proved unpopular because it is considered to be technically more demanding as elevation of the tibial tubercle was also recommended. On the other hand, Whiteside in 1993 [27] and Bulki et al. in 1999 showed the outcome in VD knees with lateral approach and tibial tubercle osteotomy (TTO) [28]. The disadvantage of this approach is the TTO, which is necessary for eversion of the patella. In 1998, Fiddian et al. presented a modified lateral capsular approach with reposition-

A longitudinal incision along the lateral border of the quadriceps muscle was described by Keblish [11], always taking care to leave 1 cm of the lateral retinaculum, from the junction between the vastus lateralis and the quadriceps tendon to the patella, through 50% of the tendon. In difficulty of the lateral closure, it was proposed two different tricks to be facilitated. On the one hand, approximation of the infrapatellar fat pad to the patellar ligament; and on the other hand, separation of the vastus lateralis from the rectus femoris, followed by suturing

medial distension laxity, and a combination of Types II and III problems [25].

ing of vastus lateralis in VD knee arthroplasties with very good results [29].

together the two tendons in a staggered position [11].

**3. Surgical approach and technique**

the axis and act only in extension [17, 25].

**3.1. Anterolateral approach**
