**3.5. The advantages of the anterolateral approach and the lateral balancing versus hazards of anteromedial approach**

patellar tracking was observed in all cases. So, the researchers concluded that lateral approach in combination with TTO is an effective technique for noncorrectable valgus deformed knee

Brilhault et al. also proposed in 2002 an interesting balancing way for VD knees by treating 13 patients with fixed VD of the knee with a semi-constrained TKA combined with advancement of the LCL by means of a lateral femoral condylar sliding osteotomy [42]. At follow-up of mean 4.6 years, the mean Knee Society Score improved from 32 to 88 and the functional score from 45 to 73 conversely. The mean tibiofemoral angle was corrected from 191° to 180°. There was no postoperative tibiofemoral or patellar instability and, in most knees, distal transposi-

Hadjicostas et al. used computer navigation in severe VD (>20°) knees in combination with an osteotomy of the lateral femoral condyle. The correct mediolateral balancing of the extension gap was confirmed by the navigation system during the operation time and before the final fixation of the lateral femoral condyle. The 15 knees were corrected to a mean of 0.5° of valgus (0–2°), with excellent mid-term results referred by the authors. Lastly, flexion of the knee statistical significantly also improved to a mean of 105° (90–130°) postoperatively, and the mean

As a consequence, the "outside-in" or the "inside-out" technique has been proposed by different surgeons with similar results, such as Keblish, Murray, Stern, Buechel [4, 8, 9, 11, 26, 29, 31]. Likewise, the "pie crust" technique has also been proposed by Ranawat as an alternative way of knee balance, plus Clarke through the taut PLC or ITB with the knee fully extended [36, 37, 54]. If the lateral release cannot sufficiently stabilize flexion and extension gaps, then the medial side of the joint should be addressed, in an effort to limit the degree of lateral softtissue release [4, 6]. Several techniques have been similarly described for successfully and

Taking into consideration firstly that many surgeons find it difficult to correct a VD by using a conventional alignment guiding system without also using a constrained implant; and secondly that a marked coronal femoral bowing deformity is easily missed [55, 56]. Huang et al. proposed, in 2016, that the use of a computer-assisted surgery (CAS) for an intra-articular bone resection is effective for increasing the accuracy and reproducibility of limb and component alignment with fewer outliers [55]. Both intra-articular bone resection and CAS are beneficial in Ranawat arthritic type-II VD knees with marked coronal femoral bowing deformity as with a rather high prevalence has been reported in Japan, China, Korea, India, Taiwan, Singapore, and Turkey. The marked coronal bowing deformity alters the relationship between the MA and anatomical axis (AA) of the femur, thereby affecting the postoperative MA and the placement of the femoral component [55, 56]. The most important Huang's et al. study finding was that CAS was more efficacious than intra-articular resection for facilitating a properly reconstructed MA, femoral component placement, and restoration of the joint-line in TKA on patients with marked coronal femoral bowing deformity. Nevertheless,

CAS did not yield a better clinical outcome at a mean follow-up of 60.2 months [55].

tion of the lateral femoral condyle achieved satisfactory stable alignment [42].

Knee Society score improved from 37 (30–44) to 90 points (86–94) [53].

safely "tightening" the incompetent MCL [10, 40, 48].

in TKA [52].

68 Primary Total Knee Arthroplasty

The medial parapatellar release arthrotomy though suggested as a standard procedure in a varus knee does not represent the optimal approach in a severe and technically demanding VD knee [4]. That is because the release of lateral patellar retinaculae is necessitated in most VD cases in order to prevent patellar instability. The latter as accompanied with medial capsulotomy results in significant impairment of the knee extensor mechanism's blood supply [57]. Though if the knee joint is approached via a lateral parapatellar arthrotomy, release of the lateral retinaculae is integrated in the approach and patella vascularity is preserved as the medial side stays undisturbed [4, 10, 57]. Laurencin reported 12% of patella avascular necrosis in medial parapatellar approach for TKA in combination with extensive lateral retinacular release [51]. Miyasaka also reported only one case out of 108, in which a patella fracture occurred 3 years after surgery which was believed to be secondary due to avascular necrosis [31]. In Nikolopoulos et al. series, no patella fracture or avascular necrosis was observed [3, 4].

Very important also in the knee extensor mechanism is the scar tissue due to previous knee's surgical operations. More specifically, scar tissue from previous tibial osteotomy makes patella's eversion problematic, and there is always a hazard for patellar ligament avulsion by forceful intraoperative retraction. Therefore, in order to protect the knee extensor mechanism, additional surgical techniques are needed either proximally (V-Y quadricepsplasty or "quadriceps snip") [58, 59] or distally to the patella with TTO [4, 6, 28, 34, 60–63]. We believe that the eversion of the patella is easily performed when a TTO is added to the lateral approach in primary TKA with severe valgus deformity, offering excellent view [4].

Likewise, in a lateral capsulotomy, the extensor mechanism is displaced medially, and as the tibia rotates internally, offers an excellent exposure of the contracted lateral structures, thus facilitates their adjustment. This encourages more conservative releases and significantly, discourages unnecessary steps that may create instability [4, 11]. In contrast in the medial approach, the lateral displacement of the extensor mechanism increases the external tibial rotation, pushing the contracted PLC away from the operative field and consequently technical difficulties in balancing the valgus knee [11]. Analyzing the literature on the subject of TTO, it has been valuated as a highly beneficial and safe procedure in achieving gentle eversion of the patella [4, 6, 28, 35, 60–63]. Besides, it prevents tibia internal rotation during patellar eversion, which may simplify proper positioning of the tibial component in severe valgus knees [4, 10, 63].

Furthermore, in a medial approach, the patella tracking is less than optimum and postoperative patellar problems are more common [10, 11, 27]. In opposition, the patellar tracking in a lateral approach is assured with the self-centering movement of the quadriceps-patellar tendon mechanism [11, 27]. In cases where a TTO is added, alignment of the extensor mechanism can be improved or adjusted when required, as osteotomy fixation at the end of the operation allows medial transfer of the patellar tendon insertion, eliminating in that way the postoperative patellar maltracking [4, 11]. In Nikolopoulos et al. series [3, 4], no patellar instability

but was associated with a worse clinical outcome [5]. The literature on the other hand refers 70–78% of full restoration of the anatomical axis in valgus knees [2, 5, 6, 9]. Incomplete axis restoration has been linked with impaired clinical outcome [4, 5]. Conversely, the authors using lateral parapatellar capsulotomy have reported better results in terms of anatomical axis correction and also in terms of clinical performance [11, 26, 64]. Besides, in cases with moderate or severe VD, an excellent decision with very good results is the use of a PCL-

Primary Total Knee Arthroplasty in Valgus Deformity http://dx.doi.org/10.5772/intechopen.74114 71

Last of all, it is very important to resume the results of the open debate: "which approach leads to better outcome?" The recent studies which compare standard medial parapatellar

(a) Nikolopoulos et al. [4] reported no statistically significant differences in terms of clinical results, on the groups of lateral approach combined with TTO vs. a standard medial approach (**Figures 6** and **7**). Nevertheless, in the lateral approach group, a valgus deviation

**Figure 7.** Profile standing position knee X-ray. Oblique direction of the wire loops for resistance to upwards pulling

forces and step at the upper part of osteotomy, preventing the proximal migration.

sparing prosthesis as Krackow et al. [10] showed.

approach versus lateral parapatellar with TTO showed the following:

occurred in 9% of the patients compared to 32% in the medial one [4].

**Figure 6.** Severe valgus deformity (A). Full correction after the operation (B).

was observed postoperatively in the group of lateral parapatellar arthrotomy combined with TTO, as we had the chance to release the soft tissues easily and to transfer the tuberosity medially in two cases, succeeding the optimal quadriceps-patella tendon balance [4].

Burki et al. observed good results in 88% of their cases by applying TTO as part of lateral approach in revision valgus TKAs. No complications were reported from the osteotomy side, apart from one case complicated with anterior tibial compartment syndrome [28]. We also presented one case in our series [3]. Burki et al. hypothesized that TTO may traumatize the anterior tibial compartment; that is why it was recommended as a standard procedure the release of the anterior tibial fascia with several longitudinal incisions [28]. The length of the osteotomized tubercle in our series were 5 cm [3, 4] versus 7 cm in Burki series [28]. That was with the purpose of avoiding tibial fractures. Piedade had 8.7% of TTO fractures and tibial plateau fissures [63]. Consequently, consideration needs to be given to the size of the bony fragment and the quality of the fixation with respect to achieving sound consolidation of the osteotomy [4].

The results in valgus knees arthroplasties with medial parapatellar capsulotomy have been inferior to those of varus knees with significant deformity [5]. Karachalios et al. mentioned the residual VD in these knees with arthroplasty did not result in early component failure, but was associated with a worse clinical outcome [5]. The literature on the other hand refers 70–78% of full restoration of the anatomical axis in valgus knees [2, 5, 6, 9]. Incomplete axis restoration has been linked with impaired clinical outcome [4, 5]. Conversely, the authors using lateral parapatellar capsulotomy have reported better results in terms of anatomical axis correction and also in terms of clinical performance [11, 26, 64]. Besides, in cases with moderate or severe VD, an excellent decision with very good results is the use of a PCLsparing prosthesis as Krackow et al. [10] showed.

Last of all, it is very important to resume the results of the open debate: "which approach leads to better outcome?" The recent studies which compare standard medial parapatellar approach versus lateral parapatellar with TTO showed the following:

(a) Nikolopoulos et al. [4] reported no statistically significant differences in terms of clinical results, on the groups of lateral approach combined with TTO vs. a standard medial approach (**Figures 6** and **7**). Nevertheless, in the lateral approach group, a valgus deviation occurred in 9% of the patients compared to 32% in the medial one [4].

was observed postoperatively in the group of lateral parapatellar arthrotomy combined with TTO, as we had the chance to release the soft tissues easily and to transfer the tuberosity

Burki et al. observed good results in 88% of their cases by applying TTO as part of lateral approach in revision valgus TKAs. No complications were reported from the osteotomy side, apart from one case complicated with anterior tibial compartment syndrome [28]. We also presented one case in our series [3]. Burki et al. hypothesized that TTO may traumatize the anterior tibial compartment; that is why it was recommended as a standard procedure the release of the anterior tibial fascia with several longitudinal incisions [28]. The length of the osteotomized tubercle in our series were 5 cm [3, 4] versus 7 cm in Burki series [28]. That was with the purpose of avoiding tibial fractures. Piedade had 8.7% of TTO fractures and tibial plateau fissures [63]. Consequently, consideration needs to be given to the size of the bony fragment and the quality of the fixation with respect to achieving sound consoli-

The results in valgus knees arthroplasties with medial parapatellar capsulotomy have been inferior to those of varus knees with significant deformity [5]. Karachalios et al. mentioned the residual VD in these knees with arthroplasty did not result in early component failure,

medially in two cases, succeeding the optimal quadriceps-patella tendon balance [4].

**Figure 6.** Severe valgus deformity (A). Full correction after the operation (B).

dation of the osteotomy [4].

70 Primary Total Knee Arthroplasty

**Figure 7.** Profile standing position knee X-ray. Oblique direction of the wire loops for resistance to upwards pulling forces and step at the upper part of osteotomy, preventing the proximal migration.


Hay et al. had randomly divided 32 patients into two groups, the one in which the lateral subvastus approach combined with a TTO was performed and the other with the medial parapatellar approach. No significant differences were found between the groups in the parameters of clinical outcome, as the ROM, the VAS score, the Western Ontario McMasters University Osteoarthritis index, and the KSS at 2-year follow-up. It was found significant better patellar tracking in the group of lateral subvastus approach combined with TTO. Due to complications related with TTO and longer surgical time (10–15 min) in the lateral approach, the researchers did not support its routine use of the except for the patients in whom problems with patellar tracking were anticipated [65].
