**3.2. Anteromedial approach**

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

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

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

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.

wide exposure of the joint surface (**Figure 4**).

62 Primary Total Knee Arthroplasty

over-resection or malaligned cuts to be avoided [2].

used to assess a correct femoral rotation [2].

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

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 lift-off test [3, 4].

The main disadvantage of the medial approach is that it is more difficult to reach the posterolateral corner during the lateral soft tissue release. For this reason, sometimes a TTO is necessary. Additionally, in cases that a medial parapatellar approach is combined with a lateral release, patellar vascular damage has been described [26].

As the LCL is the tightest more common structure, then it is the first structure to be released according to Favorito et al. The next sequential release follows is the POP (an important structure for rotational and valgus stability in flexion), the PLC, the femoral insertion of the LHG

Primary Total Knee Arthroplasty in Valgus Deformity http://dx.doi.org/10.5772/intechopen.74114 65

Whiteside described a sequence of soft tissue release based on the anatomic function of ligaments in flexion and extension consistently. A ligament attached to the femur near the epicondyles, so near the axis through which the tibia rotates and the knee flexes and extends, has an important role in flexion stability. Conversely, a ligament attached far away from the epicondyle is more important for the extension knee stability. Thus, for knees that are tight in flexion and extension, the LCL and POP tendon are released. For those knees that remain tight only in extension, ITB release is needed. Posterior capsular release is performed only when

In 1999, Krackow and Mihalko published a cadaveric study that assessed the amount of correction achieved in each step of release, comparing it in flexion and extension. The sequences on the one hand were ITB, POP, LCL, and LHG; and on the other hand LCL, POP, ITB, and LHG. They evaluated the amount of correction at 0°, 45°, and 90° of flexion. The results showed that the greatest varus rotation occurred once all structures were released, with the LHG origin last in both groups. The largest increase occurred after the LCL release. Then it is hypothesized that in severe VD, the LCL should be released first; and POP and ITB should be

Boyer et al. emphasized the purpose of the lateral approach in valgus knee arthroplasty, as it allows the automatic ITB division and elevation from the Gerdy's tubercle to be taken in continuity with the anterior compartment fascia and release of the attachments of the lateral part of the femur. More specifically in tight knees in extension, firstly the ITB was released. Afterwards, if additional releases are needed, a tight PLC was detached from the posterior condyles or transected at the level of the tibial cut from PCL insertion to the posterolateral corner. Release of the gastrocnemius and the biceps tendon should be considered in cases that the result was not sufficient. If the spacer introduced, then the ligament release stops to prevent varus laxity. [41]. In 2002, Brilhault et al. described an alternative technique for lateral structure release in association with a lateral parapatellar approach [42]. More specifically, a sliding osteotomy of the femoral LCL and POP insertions is done and the resulting bone block is mobilized and placed more distally. Bremer et al. presented in their study excellent result without any conversion to semi-constrained or constrained knee prosthesis [43]. Mullaji and Shetty described a more accurate repositioning of the epicondyle, after releasing the PLC and the ITB, with the use of a computer-navigated system [44]. Computer navigation while performing lateral femoral epicondylar osteotomy allows precise, controlled, quantitative lengthening of lateral structures,

Krackow et al. analyzed that in Grade II VD knees, the MCL may not be completely functional and a residual medial laxity is poorly tolerated postoperatively. In these conditions, the authors suggested tightening the medial ligamentous structures, particularly if the PCL has been retained

and, finally, the ITB [6].

necessary for persistent lateral ligament tightness [39].

and restoration of optimum soft tissue balance and alignment [45].

used afterward to grade the release [40].

*3.3.2. Medial soft tissue*

#### **3.3. Soft tissue balancing**

### *3.3.1. Lateral soft tissue*

It is accepted worldwide that the lateral structure release is necessary in VD knees. Nevertheless, there is an open debate on the subject of the best sequence and the best technique to perform those releases. In the abovementioned part, our experience was presented [3, 4], in accordance with the main ideas of other researchers [11, 26–29, 31–34]. In that part, the literature different proposals for soft tissue balancing of the retracted lateral structures of VD knees would be analyzed. More specifically, the releases should be performed with the knee extended and by using lamina spreaders to check the tension of the medial and lateral compartments. After each release, evaluation of the alignment and the stability of the knee should be performed in order to achieve a symmetrical rectangular extension and flexion gaps with the spacer block in situ [2, 35].

First, Krackow et al. presented in type I valgus knees the release of the ITB and the LCL, followed by the PLC, POP and the lateral head of the gastrocnemius muscle (when necessary) [10]. In type II valgus deformities, a medial ligamentous reconstruction was also proposed, either proximal or distal advancement of the medial ligament mechanism according to the surgeon's preference. Buechel presented simultaneously a sequential three-step lateral release for correcting fixed VD knees during TKA, which included firstly elevation of the ITT from Gerdy's tubercle, secondly the LCL and PT, and lastly the entire periosteum of the fibular head. Ligament balancing was achieved when the knee was aligned in both the frontal and sagittal planes with a medial and lateral opening of 2–3 mm when forced valgus and varus stress were applied at 5° of flexion.

Ranawat et al. described a stepwise technique in which the first structure to be released was the PCL; and afterward, a PLC intra-articular release by using an electrocautery at the level of the tibial cut surface. The ITB is released when necessary with multiple "inside-out" stab incisions as well as the LCL. These multiple transverse stab incisions, the so-called "pie-crusting" technique, are performed a few centimeters proximal to the joint line of the ITB with a no. 15 surgical blade, lengthens as necessary the lateral side. On the contrary, the POP is normally preserved [1]. Clarke et al. [36] and Aglietti et al. [37] performed the pie-crust technique with excellent results. It is believed that the pie-crusting technique reliably corrects moderate to severe fixed valgus deformities with a low complication rate and reasonable mid-term results. The multiple punctures reduce the risk of posterolateral instability allowing gradual stretching of the lateral soft tissues and preserving the popliteus tendon [36]. Nevertheless, one of the disadvantages of this technique is the potential risk of peroneal nerve lesion [1, 36, 37]. In a cadaveric study, Bruzzone et al. observed that the nerve is at overall risk during the release of the PLC, in the triangle defined by the POP, the tibial cut surface and the most posterior fibers of the ITB ("danger zone"), but not during the pie-crusting of the ITB ("safe zone") [38].

As the LCL is the tightest more common structure, then it is the first structure to be released according to Favorito et al. The next sequential release follows is the POP (an important structure for rotational and valgus stability in flexion), the PLC, the femoral insertion of the LHG and, finally, the ITB [6].

Whiteside described a sequence of soft tissue release based on the anatomic function of ligaments in flexion and extension consistently. A ligament attached to the femur near the epicondyles, so near the axis through which the tibia rotates and the knee flexes and extends, has an important role in flexion stability. Conversely, a ligament attached far away from the epicondyle is more important for the extension knee stability. Thus, for knees that are tight in flexion and extension, the LCL and POP tendon are released. For those knees that remain tight only in extension, ITB release is needed. Posterior capsular release is performed only when necessary for persistent lateral ligament tightness [39].

In 1999, Krackow and Mihalko published a cadaveric study that assessed the amount of correction achieved in each step of release, comparing it in flexion and extension. The sequences on the one hand were ITB, POP, LCL, and LHG; and on the other hand LCL, POP, ITB, and LHG. They evaluated the amount of correction at 0°, 45°, and 90° of flexion. The results showed that the greatest varus rotation occurred once all structures were released, with the LHG origin last in both groups. The largest increase occurred after the LCL release. Then it is hypothesized that in severe VD, the LCL should be released first; and POP and ITB should be used afterward to grade the release [40].

Boyer et al. emphasized the purpose of the lateral approach in valgus knee arthroplasty, as it allows the automatic ITB division and elevation from the Gerdy's tubercle to be taken in continuity with the anterior compartment fascia and release of the attachments of the lateral part of the femur. More specifically in tight knees in extension, firstly the ITB was released. Afterwards, if additional releases are needed, a tight PLC was detached from the posterior condyles or transected at the level of the tibial cut from PCL insertion to the posterolateral corner. Release of the gastrocnemius and the biceps tendon should be considered in cases that the result was not sufficient. If the spacer introduced, then the ligament release stops to prevent varus laxity. [41].

In 2002, Brilhault et al. described an alternative technique for lateral structure release in association with a lateral parapatellar approach [42]. More specifically, a sliding osteotomy of the femoral LCL and POP insertions is done and the resulting bone block is mobilized and placed more distally. Bremer et al. presented in their study excellent result without any conversion to semi-constrained or constrained knee prosthesis [43]. Mullaji and Shetty described a more accurate repositioning of the epicondyle, after releasing the PLC and the ITB, with the use of a computer-navigated system [44]. Computer navigation while performing lateral femoral epicondylar osteotomy allows precise, controlled, quantitative lengthening of lateral structures, and restoration of optimum soft tissue balance and alignment [45].
