Windswept deformities - An indication to individualise valgus correction angle during total knee arthroplasty

Phenotype-considered kinematically aligned total knee arthroplasty for windswept-deformity-associated osteoarthritis: surgical strategy and clinical outcomes

BACKGROUND

Windswept deformity (WSD) in relation to advanced osteoarthritis (OA) presents a significant surgical challenge in total knee arthroplasty (TKA). The primary goal of this study is to investigate the Prevalance of WSD associated osteoarthritis who have undergone total knee arthroplasty. The secondary goal is to explore the causes of WSD and its association with spinal deformity or leg length discrepancy in these patients. Finally, we evaluate the surgical outcomes of phenotype-considered kinematically aligned TKA (KA-TKA) in treating patients with WSD.

METHODS

A review was conducted on data from 40 knees of 33 WSD patients who underwent phenotype-considered KA-TKA from August 2016 to December 2020. Patient demographics, associated diseases, preoperative and postoperative knee alignment angles, range of motion (ROM), Oxford Knee Score (OKS), and Knee Society Score (KSS) were collected and analyzed. Subgroup analysis for comparing the results between valgus and varus knees were also performed.

RESULTS

Within the studied cohort of WSD patients, a substantial 64% displayed concomitant coronal spinal imbalance and 21% evidenced leg length discrepancy. Postoperative improvements were notable in knee alignments, ROM, OKS, and KSS following the application of the phenotype-considered KA-TKA approach. There were significant differences in the knee alignment angles, including mHKA, LDFA, and MPTA, between the valgus and varus side of knees (P = 0.018). However, no statistically significant difference were observed in the functional scores, comprising ROM, OKS, and KSS, between valgus and varus knees.

CONCLUSIONS

A high percentage of patients with WSD exhibited coronal spinal imbalance and leg length discrepancy. Phenotype-considered KA-TKA effectively provided alignment targets for the treatment of both varus and valgus knees in patients with WSD, achieving excellent short-term outcomes and acceptable knee alignment.

A Physiotherapeutic Approach to a Rare Case of Windswept Deformity in a Male Adolescent

Primary hyperparathyroidism (PHPT) can lead to a rare condition in children and adolescents known as windswept deformity. This deformity involves one knee exhibiting an abnormal outward angulation (valgus deformity), while the other knee shows an abnormal inward angulation (varus deformity). This asymmetrical syndrome, resembling the effect of strong winds, gives the impression that the knees are being swept in opposite directions. Various factors, such as structural bone or joint defects, accidents, or underlying disorders, can contribute to the development of windswept deformity. PHPT, a common endocrine condition characterized by elevated levels of parathyroid hormone and blood calcium, is unusual in the pediatric and adolescent populations. It can result in complications like osteoporosis and bone abnormalities, with genu valgus (outward knee angulation) being an exceptionally rare symptom. This case discusses a 19-year-old male who underwent corrective surgery for genu valgus and presented with windswept deformity due to teenage hyperparathyroidism. The case study outlines the physiotherapeutic rehabilitation strategy, emphasizing treatments such as cryotherapy, patellar mobilization, and gait training. Tailored physical therapy rehabilitation plays a crucial role in the postoperative care of patients undergoing corrective osteotomies. The results indicated a significant improvement in muscle strength, an expansion of the range of motion (ROM), and a noticeable enhancement in the individual's functional autonomy following adherence to the postoperative physiotherapy (PT) plan.

Bilateral Knee Arthroplasty in Patients Affected by Windswept Deformity: A Systematic Review

Background: “Windswept” deformity (WSD) consists of a non-frequent condition in which the patient presents a valgus deformity in one knee and a varus deformity in the other. We performed a review of the available literature to aggregate the accessible data on the outcomes of bilateral knee arthroplasty in patients with WSD and to discuss the surgical challenges that this condition might pose. Methods: A systematic review of the literature following the PRISMA guidelines was conducted. The relevant studies between 1979 and 2021 were identified. Four studies with a total of 68 patients were included for analysis. The mean follow-up for varus knees was 3.3 years, 3.1 years for valgus knees. The quality and rigor of the included studies was assessed using the Methodological index for non-randomized studies (MINORS). Results: All the studies reported improvement in knee function following knee replacement surgery, and a reduction in axial deviation of both knees, with similar results in valgus and varus knees in terms of patient satisfaction. The most relevant data were that unicompartmental knee arthroplasty (UKA) allowed for limited axial correction with slightly inferior functional results. Kinematic alignment (KA) allowed for similar results in both knees. Conclusion: The present review shows how satisfactory results can be achieved in both knees in patients with WSD and osteoarthrosis (OA). However, the operating surgeon should be aware of the importance of the implant choice in terms of functional outcomes. In the absence of extra-articular deformities, calipered KA total knee arthroplasty (TKA) can be performed on both knees with good axial correction and functional outcome. Level of evidence: II —Systematic review of cohort studies.

Asymmetric transepicondylar axis between varus and valgus osteoarthritic knees in windswept deformity can be predicted by hip-knee-ankle angle difference

PURPOSE

Studies regarding the best strategy to determine appropriate femoral component rotation during bilateral total knee arthroplasty (TKA) in wind swept deformities (WSD) are very limited. The purpose of this study was (1) to evaluate whether femoral rotational profiles differ between varus and valgus osteoarthritic knees in WSD and (2) to analyze the correlation between femoral rotational profiles and coronal radiologic parameters.

METHODS

A total of 40 patients who were diagnosed with bilateral knee osteoarthritis with WSD between January 2010 and December 2020 at a single institution were retrospectively reviewed. On axial computed tomography scans, femoral rotational profile parameters such as the clinical transepicondylar axis (cTEA) and anterior-posterior (AP) axis were compared between valgus and varus osteoarthritic knees. In standing full-limb AP radiographs, coronal radiographic parameters including hip-knee-ankle angle (HKA), valgus correction angle (VCA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), and joint line convergence angle (JLCA) were measured in both knees. The correlation between the varus-valgus cTEA difference, and differences in coronal radiologic parameters was analyzed.

RESULTS

In valgus osteoarthritic knees, cTEA was significantly increased compared to varus osteoarthritic knees by 1.5° (valgus: 7.65° ± 1.82°, varus: 6.15° ± 1.58°, p < 0.001). All coronal radiologic parameters, including HKA, LDFA, MPTA, JLCA, and VCA, were significantly different between valgus and varus knees. In correlation analysis, the varus-valgus cTEA difference was significantly correlated with LDFA (r = 0.365, p = 0.021), MPTA (r = 0.442, p = 0.004), and HKA differences (r = 0.693, p < 0.001), with the HKA difference showing the strongest correlation with the cTEA difference.

CONCLUSION

In bilateral knee osteoarthritis with WSD, valgus knees showed significantly increased cTEA compared to varus knees, and the cTEA difference positively correlated with the HKA difference between valgus and varus knees. To determine the optimal femoral component rotation during TKA in WSD, assessment of cTEA with pre-operative CT scans or careful intra-operative measurement is recommended, especially in patients with large HKA difference.

LEVEL OF EVIDENCE

III, Retrospective cohort study.

The "Wind Surf" Deformity-Correcting Fixed Flexion Deformity and Hyperextension in Bilateral CAS TKA

Severe knee arthritis can result in complex coronal and sagittal angular deformities. Windswept deformity is used to describe a varus deformity and contralateral valgus deformity. We recognized a new sagittal pattern at the time of computer-assisted surgery (CAS) in total knee arthroplasty (TKA) in which one knee has a fixed flexion deformity (FFD), while the contralateral knee has a hyperextension deformity. We propose to define it as "wind surf" deformity mimicking the opposite pull of the wind and a surfer. The incidence of "wind surf" deformity in this series was 0.96% among a cohort of 2,291 bilateral TKAs performed between 2013 and 2018. Twenty-two patients were identified with an FFD of 5° to 20° on one knee and recurvatum of -5° to -20° on the contralateral knee. Additional bone resection and soft-tissue releases were performed for the FFD with a goal to maintain residual 1° to 3° of flexion. Minimal bone resection and soft-tissue disruption were performed on the knee with hyperextension with a goal to maintain 5° to 7° of flexion. These opposite strategies applied with the help of CAS prevented recurrence resulting in satisfactory clinical results at 2-year follow-up. The "wind surf" deformity variant should be identified in patients presenting with severe knee arthritis to guide surgical treatment, prevent recurrence, and obtain favorable clinical patient outcomes.

Total knee arthroplasty combined with medial patellofemoral ligament augmentation using a Leeds-Keio ligament for 'Windswept deformity' with ipsilateral valgus deformity and permanent patellar dislocation: A case report and a literature review

We present a ‘Windswept deformity’ in patient who had osteoarthritis with a mild varus and very severe valgus with ipsilateral permanent patellar dislocation. An 83-year-old woman could not walk for the past a few years due to bilateral knee pain. The femorotibial angle was 196° in the right knee pre-operatively and 134° in the left knee with permanent patellar dislocation. She underwent a staged total knee arthroplasty (TKA) for the right knee, and a semi-constrained TKA for the left knee with medial patellofemoral ligament (MPFL) augmentation using a Leeds-Keio (LK) ligament. At the final follow-up three years after surgery, bilateral knee pain and the extension lag had disappeared and range of motion (ROM) was 0° in extension and 130° in flexion for both knees without patellar re-dislocation. This clinical case indicates that the unconstrained and semi-constrained type of TKA combined with the MPFL augmentation using an LK ligament is effective to treat a ‘Windswept deformity’.

Bilateral unicompartmental knee arthroplasty for windswept knee osteoarthritis: A report of 13 cases

BACKGROUND

Windswept deformity is a condition of the lower limbs with a valgus knee on one side and a varus knee on the other. We present a case series of bilateral unicompartmental knee arthroplasty (UKA) for windswept knee osteoarthritis (WSKO).

METHODS

We analysed the outcomes of 26 knees of 13 consecutive patients with WSKO treated with bilateral UKA. The mean age was 73.0 years and the mean follow up period was 2.6 years. Pre- and postoperative Oxford Knee Score (OKS) and Japanese Orthopaedic Association (JOA) score, radiological measurements and postoperative complications were evaluated. No knees required revision for either infection or loosening.

RESULTS

The mean preoperative OKS was 25.3 ± 9.7, which increased to 34.9 ± 5.8 at the latest follow up. The mean preoperative JOA scores for the varus and the valgus sides were 64.6 ± 12.5 and 66.9 ± 14.1, which increased to 85.0 ± 11.3 and 84.6 ± 11.2, respectively, after operation.

CONCLUSIONS

Our results show that good short-term clinical results can be achieved by bilateral UKA in cases of WSKO. Bilateral UKA may be an effective treatment for WSKO if indications are met.

Windswept deformities of the knee are challenging to manage

Background

Little has been published about TKA in windswept deformities of the knees where combined varus and valgus deformities present in the same patient. Windswept deformities present with unique problems and must be addressed as two halves of a complex entity. Through this review we aim to understand the interrelation between the deformities, examine outcomes following simultaneous bilateral total knee arthroplasty in windswept deformities, and develop an algorithm for the management of windswept deformities by total knee arthroplasty.

Methods

An extensive online literature search for the keywords yielded 31 articles on which we based our review. Articles were analyzed in context to our research questions and are presented in a tabular format for quick reference and a better perspective.

Results

The abnormal biomechanics and force moment of the knee cause progressive arthritis of the knee. The valgus deformity usually precedes a varus deformity on the contralateral knee in windswept deformities. Correct restoration of mechanical tibiofemoral angles by individualizing valgus correction angles have better outcomes after TKA.

Conclusion

A well-planned and judiciously executed simultaneous bilateral total knee replacement can offer distinct advantages to the patient and surgeon and provides optimum utilization of time and resources in the management of windswept knees.

Comparison of Valgus Correction Angle between Patients with Developmental Dysplasia Hip and Normal Volunteers Measured by Three-Dimensional Reconstruction and X-Ray

Methods

Bilateral VCA of 50 DDH patients and 56 normal volunteers were measured by Mimics software in the 3D method and X-ray in 2D. Two VCA (the upper VCA and the lower VCA) were measured in both two methods. Every VCA was measured by observer A and observer B for twice separately. The statistical analyses of the differences were calculated among the measurements of the VCA.

Results

The mean value of the upper VCA measured in 3D was 4.95° ± 0.76° in DDH group and 5.56° ± 0.62° in the normal group with significant difference (t = -6.457, p < 0.01). The VCA of DDH group and normal group measured by 3D was larger than 2D, both the upper VCA and the lower VCA. The differences indicated statistically significant. The mean value of lower VCA was 0.60° smaller than the mean value of upper VCA in normal volunteers. The mean value of the lower VCA was 0.58° larger than the mean value of the upper VCA in DDH patients.

Conclusions

Compared to X-ray, 3D reconstruction technology is more accurate without conventional limitations. The lower VCA of DDH patients should be regarded as the femoral intramedullary guide angle in TKA, especially for patients with femoral deformities.