Introduction
Coxa vara, a hip deformity characterized by a decreased femoral neck-shaft angle, can significantly affect a person’s gait and lead to functional disability. Standard treatment often entails a surgical approach known as corrective valgus osteotomy. A study spanning nearly a decade focused on evaluating the risk of deformity recurrence and determining the optimum angles for surgical correction to prevent it.
Study Analysis: Methodology and Outcomes
Published in the “Journal of Clinical Orthopaedics and Trauma,” the study titled “Surgical correction of coxa vara: Evaluation of neck shaft angle, Hilgenreiner-epiphyseal angle for indication of recurrence” (DOI: 10.1016/j.jcot.2018.06.009) provided insightful findings. Researchers, including Thammanoon Srisaarn from the Department of Orthopaedic Surgery at Phramongkutklao Hospital in Bangkok, Thailand, analyzed 34 hips in 31 patients who underwent surgical treatment for coxa vara between 2005 and 2014.
The study assessed patient-reported outcomes, preoperative and postoperative neck-shaft angles, and Hilgenreiner-epiphyseal angles, followed by evaluations at the latest follow-up. The mean age of the patients at surgery was approximately 11 years, with ages ranging from 5 to 30 years. Data collected preoperatively showed neck-shaft angles between 60 to 100 degrees and Hilgenreiner-epiphyseal angles from 60 to 90 degrees.
At the final follow-up, the neck-shaft angles ranged from 120 to 135 degrees, and Hilgenreiner-epiphyseal angles were between 22 to 35 degrees, marking a significant improvement (p < 0.001). The Harris hip score, reflecting hip function, saw a notable increase from an average of 47.20 to 79.68 (p < 0.001). The most crucial finding: no recurrence of deformities at the mean follow-up of 37.87 months. The study concluded that successful surgical correction could be achieved, with Hilgenreiner-epiphyseal angles corrected to ≤ 35 degrees or neck shaft angles to > 120 degrees to prevent recurrence.
Clinical Implications
These findings shed light on the surgical interventions needed for this debilitating condition. It reassures surgeons and patients alike that coxa vara can be addressed effectively with diligent preoperative planning and execution of the surgery with thresholds set for the critical angles. Moreover, the improvement in the Harris hip scores indicates that not only the structural deformity is being corrected but also the function and quality of life of the patients are being improved.
The Need for Long-Term Follow-Up
Despite the positive short-term outcomes, the authors of the study stress the importance of long-term follow-up to fully understand the recurrence of the deformity. As with any orthopedic intervention, the behavior of the surgical correction over time is crucial to predict future complications or the need for additional interventions.
Contributions to Orthopedic Knowledge
The paper joins a rich body of literature examining the surgical approaches to coxa vara. References such as Burns K.A. & Stevens P.M. (2001), which discuss alternative fixation options, and Weighill F.J.’s 1976 study on treatment strategies including adductor tenotomy, exemplify a longstanding endeavor to refine surgical techniques for better outcomes in treating developmental coxa vara. Moreover, recent studies by Chotigavanichaya et al. (2014) and Key J.A.’s classic work (1926) provide historical and contemporary perspectives on the complexities surrounding the surgical management of this condition.
Challenges and Future Directions
Although the research findings are promising, the challenges faced in treating coxa vara, especially in various pathologies like fibrous dysplasia, osteogenesis imperfecta, and skeletal dysplasia, remain significant. Ensuring the accurate correction of the relevant angles while minimizing trauma and facilitating a stable fixation during the surgical procedure continues to be an area of significant skill and decision-making for orthopedic surgeons.
Conclusion
The study’s implication for clinical practice is clear: surgical correction of coxa vara must be performed with precise control of the femoral neck-shaft and Hilgenreiner-epiphyseal angles to lessen the risk of recurrence. Furthermore, the comprehensive analysis contributes significantly to the existing literature, providing a more in-depth understanding for orthopedic specialists.
References
1. Srisaarn, Thammanoon, et al. “Surgical correction of coxa vara: Evaluation of neck shaft angle, Hilgenreiner-epiphyseal angle for indication of recurrence.” Journal of Clinical Orthopaedics and Trauma, vol. 10, no. 3, 2019, pp. 593-598. DOI: 10.1016/j.jcot.2018.06.009.
2. Burns, K.A., & Stevens, P.M. “Coxa vara: another option for fixation.” Journal of Pediatric Orthopedics Part B, vol. 10, no. 4, 2001, pp. 304–310. PMID: 11727373.
3. Weighill, F.J. “The treatment of developmental coxa vara by abduction subtrochanteric and intertrochanteric femoral osteotomy with special reference to the role of adductor tenotomy.” Clinical Orthopaedics and Related Research, no. 116, 1976, pp. 116–124. PMID: 1277629.
4. Chotigavanichaya, C., et al. “Results of surgical treatment of coxa vara in children: valgus osteotomy with angle blade plate fixation.” Journal of the Medical Association of Thailand, vol. 97, Sep. 2014, pp. S78–S82. PMID: 25365895.
5. Key, J.A. “The classic: epiphyseal coxa vara or displacement of the capital epiphysis of the femur in adolescence.” Clinical Orthopaedics and Related Research, vol. 471, no. 7, 2013, pp. 2087–2117. PMCID: PMC3676624.
Keywords
1. Coxa Vara Surgery
2. Corrective Osteotomy Hips
3. Hip Deformity Correction
4. Hilgenreiner-Epiphyseal Angle
5. Neck-Shaft Angle Coxa Vara