Background and Purpose of Study. The Valgus knee in total knee Arthroplasty, is considered a more demanding procedure, often with ligament balance a greater challenge than seen with neutral or Varus knees. It has also frequently been suggested that prostheses with higher levels of constraint be used to avoid late-onset instability. Various lateral release techniques have also been suggested in the literature. This study is aimed at assessing the outcomes of an unconstrained, rotating platform designed prosthesis, the LCS, using our technique, in the management of severe valgus deformity. Methods. 44 knees in 42 patients with a pre-operative valgus deformity of more than 10 degrees were included in our retrospective series. We analyzed the radiographs for the degree of correction, the angle of tibial tray implantation, and femoral implantation angle, tibial slope, as well as the presence (or degree) of lift off and any complications were noted. In this group, 7 had a Valgus deformity of greater than 25 degrees, with a mean Valgus deformity of 17,36 degrees. The mean age at operation was 65. Clinical and radiological analysis was done Pre-hospital discharge and again post-operatively 6 weeks. Results. The mean coronal alignment was corrected from 17,36 degrees to 5 degrees of Valgus post operatively. 2 knees were corrected past neutral to varus alignment. There was 1 case of bearing spin out experienced early on in the series. The mean tibial implant angle was 1,7 degrees from neutral. Lift off in the early post-operative X-rays was seen in 6 patients, however at 3 month follow up the knees appeared to be well balanced. There were no infections or revisions for wear, one re-operation for bearing dislocation, and no cases of loosening in our series. There were no cases of delayed instability. Patient satisfaction was 86 %. Conclusions. The rotating platform, mobile bearing prosthesis, using our technique, provided a reproducible correction of deformity in Valgus knees, a well-balanced knee, a low complication rate, and an excellent degree of patient satisfaction. NO DISCLOSURES

Valgus deformity is less common than varus. There is an associated bone deformity in many cases – dysplasia of the lateral femoral condyle. There are also soft tissue deformities, including tightness of the lateral soft tissues, and stretching of those on the medial side. Unlike varus, where the bone deformity is primarily tibial, in valgus knees it is most often femoral. There is both a distal and a posterior hypoplasia of the lateral femoral condyle. This results in a sloping joint line, and failure to correct this results in valgus malalignment. Posterior lateral bone loss also results in accidental internal rotation of the femoral component, which affects patellar tracking. Using the trans-epicondylar axis and Whiteside's line helps to position the femoral component in the correct rotation. Soft tissue balancing is more complex in the valgus knee. Releases are performed sequentially, depending on the particular combination of deformities. It is important to note whether the knee is tight in flexion, in extension, or both. Tightness in extension is the most common, and is corrected by release of the iliotibial band. Tightness in flexion as well as extension requires that the lateral collateral ligament +/− the popliteus tendon be released. Cruciate substituting designs are helpful in many cases, and in extreme deformity with medial stretching, a constrained or “total stabilised” design is needed. Patellar maltracking is common, and a lateral retinacular release may be needed. Beware of over-releasing the posterolateral corner, as excessive release may cause marked instability. Use the pie-crust technique of Insall

Valgus knees present a surgically demanding challenge. Dissimilar bone and soft-tissue deformities compared to varus knees complicate restoration of proper alignment, positioning of components, and attainment of joint stability. Our study examined the relationship between tourniquet time and valgus deformity. A prospective study of all valgus knees were implanted over a 30 month period with Emotion Ortho-pilot version 4.2 Navigation system (BBraun Aesculap, Tutlingen). They were done by a single knee surgeon. Tourniquet times (TT) were recorded digitally with fixed timing criteria. The software recorded all pre- and post-operative deformities. We performed the lateral parapatella approach for all valgus knees. No patella resurfacing was done but all tibiae were cemented. There were a total of 56 valgus knees (1° to 22°, Mean 5.9°, SD 4.9). The TT varied from 42 min to 121 min (mean 72 min, SD 17.4). There was a statistically significant relationship between TT and Valgus deformity. Tourniquet Time = 59.6 + 2.1 * Pre-operative Valgus (p= < 0.0001, R. 2. = 36.4%). Thirty six percent of the observations were explained by this analysis. Other factors will need to be considered in future studies. This equation can be used as a guide in the allocation of theatre time. It applies to a specific surgical team and we would expect different teams to have different coefficients. This may be useful in comparisons of different teams

The purpose of this retrospective study was to report the results using scarf, first metatarsal osteotomies, in correcting Hallux Valgus deformity with H-V angle > 35°. During the period 2003–2008 we did 23 scarf, first metatarsal osteotomies in 15 patients (8 bilateral).In order to evaluate the effectiveness of this operation, patients were clinically (aofas score) and radiologically (X –ray in 4, 8, 12 weeks) assessed. Mean follow up was 32 months. The results evaluated with the aofas score in order to study the function, the pain and the overall satisfaction of the patients. We had excellent results in 13 %, very good in 48 % good 32% and poor 7 %.There was only one complication and no one infection. According the above results it seems that scarf osteotomy is quite reliable surgical treatment of severe Hallux – Valgus deformity with an increased IM angle

Management of a knee with valgus deformities has always been considered a major challenge. Total knee arthroplasty requires not only correction of this deformity but also meticulous soft tissue balancing and achievement of a balanced rectangular gap. Bony deformities such as hypoplastic lateral condyle, tibial bone loss, and malaligned/malpositioned patella also need to be addressed. In addition, external rotation of the tibia and adaptive metaphyseal remodeling offers a challenge in obtaining the correct rotational alignment of the components. Various techniques for soft tissue balancing have been described in the literature and use of different implant options reported. These options include use of cruciate retaining, sacrificing, substituting and constrained implants.

Deformity correction is a fundamental goal in total knee arthroplasty. Severe valgus deformities often present the surgeon with a complex challenge. These deformities are associated with abnormal bone anatomy, ligament laxity and soft tissue contractures. Distorted bone anatomy is due to bone loss on the lateral femoral condyle, especially posteriorly. To a lesser extent bone loss occurs from the lateral tibia plateau. The AP axis (Whiteside's Line) or epicondylar axis must be used as a rotational landmark in the severely valgus knee. Gap balancing techniques can be helpful in the severely valgus knee, but good extension balance must be obtained before setting femoral rotation with this technique. Coronal alignment is generally corrected to neutral or 2- to 3-degree overcorrection to mild mechanical varus to unload the attenuated medial ligaments.

The goal of soft tissue releases is to obtain rectangular flexion and extension gaps. Soft tissue releases involve the IT band, posterolateral corner/arcuate complex, posterior capsule, LCL, and popliteus tendon. Assessment of which structures is made and then releases are performed. In general, pie crust release of the IT band is sufficient for mild deformity. More severe deformities require release of the posterolateral corner / arcuate and posterior capsule. I prefer a pie crust technique, while Ranawat has described the use of electrocautery to perform these posterior/ posterolateral releases. In most cases the LCL is not released, however, this can be released from the lateral epicondyle, if necessary.

Good ligament balance can be obtained in most cases, however, some cases with severe medial ligament attenuation require additional ligament constraint such as a constrained condylar implant.

Deformity correction is a fundamental goal in total knee arthroplasty. Severe valgus deformities often present the surgeon with a complex challenge. These deformities are associated with abnormal bone anatomy, ligament laxity and soft tissue contractures. Distorted bone anatomy is due to bone loss on the lateral femoral condyle, especially posteriorly. To a lesser extent bone loss occurs from the lateral tibia plateau. The AP Axis (Whiteside's Line) or Epicondylar axis must be used as a rotational landmark in the severely valgus knee. Gap balancing techniques can be helpful in the severely valgus knee, but good extension balance must be obtained before setting femoral rotation with this technique. Coronal alignment is generally corrected to neutral or 2- to 3-degree overcorrection to mild mechanical varus to unload the attenuated medial ligaments.

The goal of soft tissue releases is to obtain rectangular flexion and extension gaps. Soft tissue releases involve the IT band, Posterolateral Corner/Arcuate Complex, Posterior Capsule, LCL, and Popliteus Tendon. Assessment of which structures is made and then releases are performed. In general Pie Crust release of the ITB is sufficient for mild deformity. More severe deformities require release of the Posterolateral Corner/Arcuate Complex and Posterior Capsule. I prefer a pie crust technique, while Ranawat has described the use of electrocautery to perform these posterior/ posterolateral releases. In most cases the LCL is not released, however, this can be released from the lateral epicondyle, if necessary.

Good ligament balance can be obtained in most cases, however, some cases with severe medial ligament attenuation require additional ligament constraint such as a constrained condylar implant.

Deformity correction is a fundamental goal in Total Knee Arthroplasty. Severe valgus deformities often present the surgeon with a complex challenge. These deformities are associated with abnormal bone anatomy, ligament laxity and soft tissue contractures. Distorted bone anatomy is due to bone loss on the lateral femoral condyle, especially posteriorly. To a lesser extent bone loss occurs from the lateral tibia plateau. The AP Axis (Whiteside's Line) or Epicondylar axis must be used as a rotational landmark in the severely valgus knee. Gap balancing techniques can be helpful in the severely valgus knee, but good extension balance must be obtained before setting femoral rotation with this technique. Coronal alignment is generally corrected to neutral or 2 to 3 degree overcorrection to mild mechanical varus to unload the attenuated medial ligaments.

The goal of soft tissue releases is to obtain rectangular flexion and extension gaps. Soft tissue releases involve the IT band, Posterolateral corner/Accurate Complex, Posterior Capsule, LCL, and Popliteus Tendon. Assessment of which structures is made and then releases are performed. In general Pie Crust release of the ITB is sufficient for mild deformity. More severe deformities require release of the Posterolateral corner/Accurate Complex and Posterior Capsule. I prefer a pie crust technique, while Ranawat has described the use of electrocautery to perform these posterior/ posterolateral releases. In most cases the LCL is not released, however, this can be released from the lateral epicondyle if necessary.

Good ligament balance can be obtained in most cases, however, some cases with severe medial ligament attenuation require additional ligament constraint such as a constrained condylar implant.

Introduction: The conventional radiological assessment of hallux valgus (HV) involves measuring the intermetatarsal angle, HV angle, congruity of the metatarsophalangeal joint and the overall clinical deformity of the forefoot. However, in the current practice, these angles are seldom measured. We observed consistent displacement of the lateral sesamoid (LS) along with HV deformity. The position of the LS in relation to the head of the first metatarsal has never been studied before. We aim to study this pattern of the LS and to quantify the severity of the deformity which could help make clinical decisions.

Methods: 112 radiographs of 60 consecutive patients who underwent a weight bearing radiographs of their feet were studied. Statistical analysis was performed to identify the correlation of displacement with conventional angle measurements.

Results: A definite pattern in displacement of the lateral sesamoid was noted. This displacement also showed a statistical correlation with the conventional measurement of inter-metatarsal angle.

Discussion: Previous research which studied the displacement of medial sesamoid in these deformities was not received with great enthusiasm due to the difficulty in locating the medial sesamoid through the head of the metatarsal. In contrast, the lateral sesamoid lies laterally and any progressive deformity makes it more accessible to assessment. We report a consistent pattern in the displacement of the LS and classified as the position as normal, mild, moderate and severe. As it does not involve any measurements, we believe, this is a quick and reliable technique of assessment of HV deformity and should help to base our operative decisions.

Objectives

The approach in total knee arthroplasty (TKA) with severe valgus deformity is controversial. The lateral parapatellar approach has been proposed for several years, but surgical technique of this approach was unusual and difficult. Therefore, we have consistently been selected medial parapatellar approach (MPP) for all cases. In this study, we investigated the short term results of TKA for severe valgus deformity with MPP about clinical and radiographic assessment.

A significant number of hallux valgus is associated with valgus deviation of 2nd, 3rd and 4th toes. We recommend correction of the valgus deformity of all four rays simultaneously., because recurrence of the hallux valgus is very frequent if only the first ray is realigned.

From 1978 to 1990 a series of 236 feet were operated upon for hallux valgus deformity using a distal osteotomy of the first rnetatarsal. These cases were followed up for a mean of 6, 1 years and showed that the recurrence rate was as high as 28%. Our observation was that, in the majority’ of cases, recurrence of the deformity occurred in those feet in which hallux valgus was combined with valgus deformity of the lesser toes due to varus deviation of the corresponded metatarsals. From 1990 to 1998, another series of 386 feet were operated for hallux valgus. In more than one third of them (142 feet in 96 patients) hallux valgus was associated by valgus deformity of the 2nd, 3rd, and 4th toes. These cases were operated using a distal osteotomy of the first rnetatarsal combined with osteotomies of lesser metatarsals aiming not only to face metatarsalgia, but to correct valgus deformity of the lesser toes simultaneously. These patients were followed up for a mean of 4.8 years.

The results were excellent in 73 feet, good in 47, fair in 17 and poor in 5. The recurrence rate dropped to 7%.

If hallux valgus is combined with valgus deformity of the lesser toes, correction of only the first ray creates a gap between first and second toe. Consequently there is no blocking effect toward valgus deviation of the great toe due to the gap remaining between the first and second toe.

The above combined procedure seems to give better results with low recurrence rate in comparison with the results of single correction of the first ray.

Introduction Hallux valgus (HV) is a common foot deformity with a prevalence of up to 48%. It usually affects females and its radiographic severity is expressed by various angles, such as the HV Angle, the Inter Metatarsal Angle (IMA) and the Distal Metatarsal Articular Angle (DMAA).

The aim of our study was to assess the impact that HV has on patients’ quality of life and to correlate each of the above angles to SF-36 sub-scales.

Method Twenty-three female patients with a mean age of 48.5 years were included in the study. Diagnosis was established by clinical and standardised radiological examination. Patients were medically fit and the only pathology that could affect their SF-36 score was HV. They all completed in the SF-36 form on their first visit at the clinic. Statistical analysis was performed via SPSS 12.0.

Results Mean radiographic angular deformities measured 35, 13, and 17 degrees for HVA, IMA, and DMAA respectively. The HVA and IMA demonstrated significant association (p=0.018) as regarding their severity, indicating that they probably interact during the progression of the deformity. The Physical Component Summary score was significantly lower in our patients than the recommended norms for the same age (p=0.015). HVA significantly affected the General Health (p=0.023), IMA, the Role Physical (0.039), Role Emotional (p=0.056) and Mental Health (p=0.043). The coefficients were all negative indicating a worse health scenario as the deformity increases.

Conclusion These results suggest that HV deformity seriously affects peoples’ quality of life. In addition, according to our data, surgical treatment is absolutely indicated and operative correction of the angular deformities would be expected to normalise those patients’ SF-36 score. However, this remains to be proved.

Aims: Neutral alignment and soft tissue balance are universally accepted as the most important objectives when performing a total knee replacement regardless of the preoperative deformity and implant type. Nevertheless, there is scarce evidence in the scientific literature of the effect of surgical correction on varus/valgus alignment variation during follow-up. We wanted to verify if the femur-tibial alignment after a total knee replacement was maintained at three years’ follow-up, and whether any variation might be correlated to anatomical characteristics before surgery, and to position and fixation of the tibial component within bone.

Methods: We assessed thirty patients with a cemented TKR implant preoperatively, and at one and three years’ follow-up. Lower limb alignment and tibial component position were evaluated manually from antero-posterior radiographs in weight-bearing position. The tibial component varus/valgus migration was measured by Roentgen Stereophotogrammetry.

Results: In spite of the correct alignment obtained during surgery, at 3 years’ follow-up 40% of patients presented an alignment variation of over 3°. The variation of deformity was not correlated with the preoperative deformity, nor with the tibial component position with respect to the tibial shaft nor with its migration.

Conclusions: After total knee arthroplasty, the recurrence of deformity is a common finding in spite of correct alignment obtained during surgery, but it does not influence the clinical result at mid-term follow-up. Anyway the unbalanced forces determining variation in coronal alignment, at a longer follow-up might produce deficiency of soft tissue structures, loosening of the prosthesis component, or polyethylene failure, leading to revision surgery.

Introduction: There are more than 150 different methods of surgical correction of hallux valgus deformity. In our institution there is a long tradition of SCARF osteotomy. We hereby present the longterm results of the SCARF.

Material & Methods: During the years 1995 and 1996 111 patients with 128 feet were operated on for a hallux valgus deformity by the SCARF osteotomy. Of those, 81 patients with 95 feet could be seen for follow up. The mean age at time of surgery was 50.9 (21–78) years. A clinical and radiographic examination was done.

Results: After an average time of 121.9 (107–141) months 92% of the patients were very satisfied with the result of their surgery. The VAS for pain improved from an average of 6.5 to 0.34. The AOFAS score for the forefoot improved from a preoperative average of 54.4 to a postoperative average of 91.6. The radiographic evaluation gave the following results: the preoperative HVA of 31.7° improved to an average of 16.8°; the preoperative IMA of 14.8° improved to an average of 7.6°. The preoperative average dorsal extension of the MTPI did not change very much from 48.6° to 50.6°, the preoperative plantar flexion decreased from an average of 50.6° to 15°. Two patients had to be reoperated because of a recurrent hallux valgus deformity. Five other patients had a recurrent deformity, but did not need any further surgery. We could observe 3 patients with an overcorrection where one needed another surgery. No head necrosis was seen.

Conclusion: Overall the SCARF osteotomy gave good and predictable results with a good correction of the deformity and a low potential for recurrence if applied for the right patient group.

Purpose: The evaluation of midterm results of a proposed surgical technique for the correction of hallux valgus deformity.

Material-Methods: Fifty-one female patients with sixty-two hallux valgus deformities were operatively treated between 1997–2002. The average age was 54.9 years and the mean follow up period was 32.7 months. A modified – 90 degrees angled – chevron osteotomy fixed with a Hebert screw was performed in all patients. Concomitant lesser toes abnormalities were managed at the same time. Preoperative, postoperative and last follow up radiographic intermetatarsal (IMA) and hallux valgus (HVA) angles, were measured and compared. Subjective analysis consisting of the AOFAS hallux scale was performed.

Results: The averaged preoperative HVA was 34.1 (range 22–56) and the averaged IMA 15.5 (range 10–29). The corresponding postoperative angles were 14.2 (range 0–28) and 8.1 (range 6–22). The mean AOFAS score was 94.3 (65–100). All the osteotomies were fused and there was not any case of non-union or loosening. Two patients showed late recurrence of the deformity but refused any further treatment.

Conclusions: Hebert screw is a reliable fixation method of the chevron osteotomy for the treatment of hallux valgus. The osteotomy site is firmly secured, avoiding early displacement of the lateral fragment.

Introduction: We describe an operation, which have performed in patients with rheumatoid arthritis, valgus deformities of the ankle and hind foot with overlying ulcer.

Materials and Methods: The operation has been performed in seven female patients with an average age of 69 years. All patients had severe functional problems.

Technique: The ulcer is excised through an elliptical incision and the medial malleolous is excised level with the ankle joint. Then the tibia surface is osteotomized just above the ankle joint with a planar cut perpendicular to the long axis of the tibia in both saggital and coronal planes. The talus is also transected, with the cut parallel to the sole of the foot and the arthrodesis is closed. The patient starts to mobilize weight bearing in a POP cast with an over boot with rigid sole and rocher in 2–3 days. After 8 weeks the patient is transferred to a shoe with fixed double iron attached. This is retained until radiological union occurs.

Results: Primary healing of the skin was obtained in all cases. Each patient was able to walk within the bounds of their disease early after surgery. In every case union has been delayed. No patient has had recurrent deformity or ulceration.

Conclusion: Such deformity severely impairs the functional status of the patient and may threaten the viability of the foot. Primary surgery with excision of the medial malleolous and correction of the deformity of the ankle has proved successful in treating pain, deformity and ulceration in this small series.

Introduction: The chevron osteotomy is an accepted method for the correction of mild and moderate hallux valgus and generally advocated for patients younger than the age of sixty years. In the current work the finite element analysis applied to calculate the stress (force per unit area) on different cuts in the metatarsal bone model of the first ray in the human foot.

Material and Methods: The cuts have the form of a simple angle with 90 degrees ‘modified chevron osteotomy’, 60 ‘typical chevron osteotomy’ 70, 50 and 30, openings correspondingly, and share a common corner C, which is at the centre of a circle that fits the head of the metatarsal. In order to calculate the maximum stresses on the cuts, the bone is assumed to be with a 150 angle to the floor, which is the angle that it takes during the push-off phase.

Results: The calculations show a considerable difference on the stress distribution on the differnt cuts. In particular in the ‘90 degrees cut’ the normal (to the cut) stress is much larger than the shear stress. The opposite is true for the 60 cut. Since shear stresses are the ones that cause material failure, it is predicted that the 90 cut will heal much faster than the 60 cut. The nodes along the cuts where the normal and the shear stress were calculated in different osteotomies.

Conclusion: The FEM analysis confirm our clinical results of this modified chevron osteotomy of 90 degrees. The osteotomy site is firmly secured, avoiding early displacement of the lateral fragment and give earlier fusion.

Soft tissue balancing in fixed genu valgum can be challenging and may lead to instability in flexion. Current techniques involve release of the tight secondary structures initially, with the fascia lata and the lateral capsule usually addressed first, and then the posterior capsule if necessary. If ligament testing does not permit neutral alignment in extension, release of the lateral collateral ligament becomes necessary.

The most common way of achieving neutral alignment is by lengthening the lateral structures through elevation of the proximal insertion of the lateral collateral ligament (LCL). This technique has two drawbacks: the lengthening affects both extension and flexion gaps and may give rise to excessive external rotation of the femoral implant, with too much offset of the rotational centre. Particularly when non-constrained prostheses are used, the resulting lateral instability in flexion can be a problem.

An alternative is to perform a release at the level of the distal insertion of the LCL, as advocated by Keblish and Buechel. However, this still induces undue external rotation of the femoral implant.

We think that if the situation in flexion before any release is satisfactory in terms of the patella, it should not be changed. This means that in order to maintain optimal patellofemoral function, the flexion gap should be addressed before any release. The task is then to achieve a good extension gap with a well-aligned knee. In fixed valgus deformities, this means distal translocation of the femoral insertion of the LCL by distal sliding lateral condylar osteotomy. This procedure aims to preserve the flexion condition and to allow distal slide of the lateral condylar osteotomised fragment. In doing the osteotomy, it is important to make the lateral fragment sufficiently large to allow relocation of the osteotomised fragment inside the prosthesis. This provides the immediate stability necessary for good healing. We have been using two simple cortical screws to ensure stability of the fragment.

This paper reports our experience in 100 cases.

Previous studies of osteoarthritic knees have examined the relationship between the variables body mass index (BMI) and weight on the one hand and coronal plane deformity on the other. There is a consensus that weight and BMI are positively correlated to the degree and progression of a varus deformity. However, there does not appear to be a consensus on the effect of these variables on knees with a valgus deformity. Indeed, the view has been expressed that in knees with a severe deformity a relationship might not exist. A review of these studies reveals that in all cases, the alignment of the lower limb was obtained from a standing antero-posterior long leg radiograph. In no cases was the deformity in the sagittal plane measured. This study analyses the relationship between BMI, weight, deformity in the sagittal plane and valgus deformity.

The study group consisted of 73 patients with osteoarthritis and valgus knees. All of them had failed conservative treatment for their symptoms and were listed for navigated TKA. Their weight and height were measured two weeks preoperatively and the BMI calculated. At operation the coronal and sagittal deformities were measured using the Orthopilot^® navigation system (BBraun Aesculap, Tuttlingen). The results were analysed using SPSS 15.

Regression analysis showed a significant relationship (p< 0.05) with a negative correlation between valgus deformity and weight. the correlation coefficient for flexed knees (−0.59) showed a moderately strong relationship whereas that for extended knees (−0.38) showed a relatively weak relationship.

It is acknowledged that there is an increased force on the lateral compartment with increased valgus deformity. a larger deformity causes a larger moment arm about the centre of the knee. this study has shown that at the time of surgery, individuals with lower weights have larger valgus deformities. we postulate, therefore, that when the moment due to the weight of the individual and the length of the moment arm exceeds a certain value, a symptomatic threshold is crossed. in the presence of a fixed flexion deformity, the force on the patella-femoral joint is increased, contributing further to the onset of discomfort.

Further investigation into the subsets of valgus knees appears to be warranted.

In arthritic knees with severe valgus deformity Total Knee Arthroplasty (TKA) can be performed through medial or lateral parapatellar approaches. Many orthopaedic surgeons are apprehensive of using the lateral parapatellar approach due to lack of familiarity and concerns about complications related to soft tissue coverage and vascularity of the patella and the overlying skin. However surgeons who use this approach report good outcomes and no added complications. The purpose of our study was to compare outcomes following TKA performed through a medial parapatellar approach with those performed through a lateral parapatellar approach in arthritic knees with severe valgus deformity.

We conducted a retrospective review of patients from two consultants using computer navigation for all their TKAs. All patients with severe valgus deformities (Ranawat 2 & 3 grades) operated on between January 2005 and December 2011 were included. 66 patients with 67 TKAs fulfilled the inclusion criteria. Patients were group by approach; Medial = 34TKAs (34 patients) or Lateral = 33 TKAs (32 patients). Details were collected from patients' records, AP hip-knee-ankle (HKA) radiographs and computer navigation files. Outcome measures included lateral release rates, post-operative range of knee movements, long leg mechanical alignment measurements, post-operative Oxford scores at six weeks and one year, patient satisfaction and any complications. Comparisons were made between groups using t-tests.

The total cohort had a mean age of 69 years [42–82] and mean BMI of 29 [19–46]. The two groups had comparable pre-operative Oxford scores (Medial 41[27–56], Lateral 44 [31–60]) and pre-operative valgus deformity measured on HKA radiographs (Medial 13° [10°–27.6°], Lateral 12° [6°–22°]). Three patients in the Medial group underwent intra-operative lateral patellar release to improve patellar tracking. Seven patients in the Lateral group had a lateral condyle osteotomy for soft tissue balancing (one bilateral). There was no statistically significant difference between groups at one year follow up for maximum flexion (Medial 100° [78°–122°], Lateral 100° [85°–125°], p=0.42), fixed flexion deformity (Medial 1.2° [0°–10°], Lateral 0.9° [0°–10°], p=0.31) or Oxford score (Medial 23 [12–37], Lateral 23 [16–41], p=0.49). Similarly there was no difference in the patient satisfaction rates between the two groups at one year follow up. However there was a statistically significant difference in the mean radiographic post-operative alignment angle measurement (Medial 1.8° valgus [4° varus to 10° valgus], Lateral 0.3° valgus [5° varus to 7° valgus], p=0.02). One patient in the Medial group had a revision to hinged knee prosthesis for post-operative instability. There was no wound breakdown or patellar avascular necrosis noted in either of the groups.

The lateral parapatellar approach resulted in slightly better valgus correction on radiographs taken six weeks post-operatively. We found no major complications in the Lateral parapatellar approach group. Specifically we did not encounter any difficulties in closing the deep soft tissue envelope around the knee and there were no cases of patellar avascular necrosis or skin necrosis. Hence we conclude that lateral parapatellar approach is a safe and reliable alternative to the medial parapatellar approach for correction of severe valgus deformity in TKA.