**3.1. Anterolateral approach**

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

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

In the anterolateral approach, as described in detail by Nikolopoulos et al. [4, 17], a straight midline skin incision is followed by a lateral parapatellar capsulotomy. The ITB is next elevated from Gerdy's tubercle. Also, in order to medially displace the patella, TTO is performed laterally, leaving the soft tissues intact medially. The TTO length measures 5–6 cm, whereas proximally, at the upper part of the patellar tendon insertion, the transverse part of the osteotomy prevents proximal migration. The tibial tubercle is hinged medially, hence offering a wide exposure of the joint surface (**Figure 4**).

Tibial resection is done—directing the level of the cut perpendicular to its longitudinal axis. After removal of the osteophytes, especially in the lateral tibial plateau, a resection must always be performed from 6 to 8 mm in the medial compartment (**Figure 5**). In cases of severe bony deformity of the tibial plateau, no bone may be resected on the lateral side so as medial over-resection or malaligned cuts to be avoided [2].

The distal femoral cut is done in 3° of valgus in relation to the femoral axis. The distal femoral cut at 3° only, instead of 5–7° that applies in varus knees, protects against under-correction. A slightly more varus result has been proposed during TKA for VD to counteract any tendency for the knee to shift back into valgus [11]. In order to avoid elevation of the joint line, caution should be taken so as the lateral femoral condyle not to be over-resected [4]. In severe VD of the distal femur, Rossi et al. proposed [2] no lateral condyle distal femoral resection or minimal (1–2 mm) resection. Also the femoral resection in the medial condyle should be no more than 10 mm (usually 7–8 mm). The surgeon should also pay attention to the lateral condylar hypoplasia in VD that can determine a great intra-rotation of the components if a posterior reference is used [2]. Both the AP axis of Whiteside and the epicondyle axis are used to assess and confirm the orientation of the femoral cut [3, 4]. Arima et al., taking into consideration this aspect, utilized the usage of the anteroposterior axis so as to give the proper femoral rotation in valgus anatomy [30]. In cases of severe trochlear dysplasia, the Whiteside line is extremely difficult to be identified, so the epicondylar axis or parallel to the tibial cut technique must be used to assess a correct femoral rotation [2].

Therefore, tibial tubercle transfer is necessary for satisfactory alignment. Tibial tubercle fixation can be performed even with two 4.5 mm cortical screws or with three wire loops (preferred). The oblique direction of the wire loops offers better resistance to proximal directed forces [4].

Primary Total Knee Arthroplasty in Valgus Deformity http://dx.doi.org/10.5772/intechopen.74114 63

Τhe main reasons and advantages considered of the group of orthopedic surgeons [1–4] preferring the anterolateral procedure are mainly three. Firstly the lateral release, as part of the approach, is usually necessary in VD knees and it does not seriously impair the extensor mechanism vascular supply as in medial arthrotomy. Secondly, the lateral approach facilitates the release of the lateral contracted elements, offering better surgical view and lastly the

The anteromedial is the standard approach being used commonly all these decades by the surgeons in the VD knees and with no contraindications [1–6]. A straight midline skin incision is performed, followed by a standard medial parapatellar arthrotomy. The tibial and femoral bone cuts followed the same technique as the one described in the anterolateral approach. In order to achieve optimal soft tissue balancing, as contracture of the ITB is noted with the knee in full extension, release is performed by elevation from Gerdy's tubercle or fractional lengthening with multiple stab wounds. An additional release includes the LCL from the distal part of the femur and popliteus [4]. In most cases with mild to severe VD, release of the posterolateral capsule is performed. The PLC is released either from the distal part of the femur, with the knee in flexion, using a curved osteotome; or with the knee in full extension, fractionally lengthening by means of multiple stabs punctures ("pie crust" technique) [1, 32]. Finally, lateral retinacular release is required to facilitate patellofemoral tracking. Tracking of the extensor mechanism is again evaluated with use of the appropriate

possibility to medicalize the tubercle if required improves the patella tracking [2, 4].

Patellar tracking was finally checked with the "no-thumb" test.

**Figure 5.** During operation, fixing the tibial tuberosity osteotomy with three loops.

**3.2. Anteromedial approach**

lift-off test [3, 4].

At this phase, especially for tight knees in flexion, the sub-periosteal POP and LCL elevation from the epicondyle is performed. In tight knees, PLC release could be performed in both flexion and extension. During closure, the tibial tuberosity is generally fixed to its original position or slightly more medially in cases that the patella tends to track laterally and dislocate.

**Figure 4.** Surgical procedure of the tibial tubercle osteotomy stages (TTO).

**Figure 5.** During operation, fixing the tibial tuberosity osteotomy with three loops.

Therefore, tibial tubercle transfer is necessary for satisfactory alignment. Tibial tubercle fixation can be performed even with two 4.5 mm cortical screws or with three wire loops (preferred). The oblique direction of the wire loops offers better resistance to proximal directed forces [4]. Patellar tracking was finally checked with the "no-thumb" test.

Τhe main reasons and advantages considered of the group of orthopedic surgeons [1–4] preferring the anterolateral procedure are mainly three. Firstly the lateral release, as part of the approach, is usually necessary in VD knees and it does not seriously impair the extensor mechanism vascular supply as in medial arthrotomy. Secondly, the lateral approach facilitates the release of the lateral contracted elements, offering better surgical view and lastly the possibility to medicalize the tubercle if required improves the patella tracking [2, 4].
