*3.3.2. Medial soft tissue*

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

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

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

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].

release, patellar vascular damage has been described [26].

**3.3. Soft tissue balancing**

*3.3.1. Lateral soft tissue*

64 Primary Total Knee Arthroplasty

in situ [2, 35].

applied at 5° of flexion.

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 [44]. A small bone plug with the attached insertion of the PCL, and the PLC is removed from the tibia and moved distally, securing it with transosseous sutures. In this technique, the MCL is tightened by moving a bone block distally with its tibial insertion [45].

valgus angle at 7° after surgery; but with no alignment or varus-valgus stability deterioration during the 6-year follow-up period. Nevertheless, in greater than 25° VD, knees had a tendency for increased posterior laxity. Lastly, Whiteside presented patellar subluxation and

Primary Total Knee Arthroplasty in Valgus Deformity http://dx.doi.org/10.5772/intechopen.74114 67

Conversely, Krackow [10, 40, 45] and Healy [48] recommended medial soft-tissue advancement or reconstruction combined with lateral release. To be more specific, Krackow and Mihalko [40] studied in cadavers the flexion-extension joint gap changes after lateral structure release for VD correction in TKA and concluded that in severe valgus deformities, the LCL should be considered first for release and the POP and ITB be used to grade the release. In their series of 99 TKA, the Grade I VD knees (based on Ranawat classification) were treated with lateral release versus the Grade II VD knees which were treated with ligament reconstruction procedures on the medial side. The 72% of the patients referred excellent results whereas 18% good, 7% fair, and 2% poor [45]. Healy et al. presented, in Grade II VD knees, lateral ITB release in combination with proximal MCL advancement with bone plug reces-

Apart from Krackow cadaveric study, extremely interesting results published in 2001 by Peters et al. who studied the flexion-extension gap symmetry during sequenced release of the lateral structures in VD knees. It is concluded that complete release of the ITB at the joint line had a more profound effect on the extension than the flexion gap. On the contrary, complete release of the LCL/POP from the femur more profoundly affected the flexion than the extension gap; both of these release steps produced gap increases that were significant (7–12 mm). Selective fractional lengthening of the ITB, the PLC, and the POP tendon alone produced smaller magnitudes

Above and beyond, in 2004, Politi and Scott referred, good-to-excellent results in TKAs with VD >15°, and achieved soft tissue balance, with a lateral cruciform retinacular release, and without LCL and POP release in 32 out of 35 cases [50]. In the remaining three cases, the extension gap balancing was achieved by adding, apart from the lateral cruciform retinacular release, the LCL and POP partial release. No further prosthetic constraint was necessary following these releases, and these knees have remained clinically stable at their latest mean 3.4-year follow-up despite the partial release of the LCL and its contribution to flexion gap

Stern et al. accomplished ligamentous balancing in TKAs with VD >10°, with sequential releases from the lateral side of the femur and without MCL reconstruction, achieving 91% of good-to-excellent results. The postoperative axis alignment was 5–9° valgus [31]. Likewise, Laurencin et al. reviewed TKAs with 25° VD, where lateral retinacular release was accompanied by sequential lateral release achieving postoperative anatomic alignment between 0° and

In 2014, Chalidis et al. presented the results of 57 Grade II VD knees that underwent a primary TKA via lateral parapatellar approach with a global step-cut "coffin" type TTO over a 10-year period. Postoperatively, there was a significant improvement in knee extension, flexion, Knee Society Pain and Function Scores and WOMAC Osteoarthritis Index. Congruent

sion, with fully stable and functional ROM at 4–9 years follow-up [48].

of correction, which more symmetrically affected flexion-extension gaps [49].

dislocation in less than 1% in the study [27].

stability [50].

10° valgus, in 96% patients [51].

The advancement of the MCL from the epicondyle or a division and imbrication in order to tighten it can be performed in conjunction with the use of constrained condylar prosthesis [6].
