Left-sided limp of a few years' duration in a patient with limited abduction of the hip.
The patient presented with a history of a left-sided limp of a few years' duration. The patient had no associated symptoms and took part in all normal physical activities.
On examination he had a limb length discrepancy of 1.5cm on the left side. The leg had a full range of flexion, internal and external rotation, but had a reduced range of abduction to 30 degrees on the left as compared with 45 degrees on the right side.
A pelvic radiograph demonstrated typical coxa vara with a neck shaft angle of between 90 and 100 degrees (Fig. 1).
Coxa vara was first described by Fiorini in 1881. This rare deformity of the hip tends to present in early childhood with concerns regarding a limp. This may be associated with a reduced range of movement of the hip joint, especially abduction and internal rotation (1).
It is bilateral in one third to one half of cases. Coxa vara can be congenital (noted at birth and differentiated from developmental dysplasia of the hip by MRI), developmental (AD, progressive), or acquired (e.g. trauma, Perthes disease, slipped capital femoral epiphysis).
Carroll described it as a decrease in the neck shaft angle to less than 110 degrees (2).
On radiographs it is characterised by a reduction in the neck shaft angle, with the physeal plate being in a vertical position and a triangular metaphyseal fragment being visible in the inferior part of femoral neck (Fairbanks triangle). The fragment is surrounded by an inverted Y pattern (1).
There have been multiple attempts to classify this condition radiologically, however it is not possible to rely on any of these signs for early management decisions (3).
Treatment of the condition aims at normalising the forces across the proximal femoral epiphysis, from shearing forces in coxa vara to compressive forces (2,4). This is performed by doing a corrective osteotomy (Fig. 3). In reviews, the most reliable predictor of progression and recurrence post-operatively was found to be Hilgenreiner's epiphyseal angle (2,5). This is determined by the use of Hilgenreiner's line as the horizontal axis, with a line through the defect adjacent to the metaphyseal axis (5).
Weinstein (5) found that coxa vara progressed if Hilgenreiner's angle was greater than 60 degrees, whereas there was spontaneous correction if the angle measured less than 45 degrees. For a surgical correction to be successful, it was demonstrated necessary to obtain Hilgenreiner's angle of less than 38 degrees. Cases with angles greater than 40 degrees required revision surgery for recurrence.
The functional and radiological results were found to be good in 95% of cases when correction was obtained before the age of 10 years (2).
Coxa vara of the left hip
1. On the anteroposterior (AP) view of the pelvis X-ray, the left femoral neck-shaft angle is significantly decreased, measuring less than the normal reference range (approximately under 110°).
2. Indirectly, the femoral neck morphology appears suboptimal; there is increased inclination between the epiphysis and the growth plate, and a triangular-shaped high-density area (“Fairbanks triangle”) is visible on the lateral side of the femoral neck, suggesting a structural abnormality of the femoral neck.
3. Compared to the contralateral side, the left femoral neck is shorter, and the hip abduction angle is reduced, consistent with the clinically observed restriction in hip abduction.
Based on the imaging findings and clinical history, possible diagnoses include:
1. Developmental Coxa Vara: A markedly reduced femoral neck-shaft angle is a typical feature. Children often present with a limp or limited range of hip motion; in this case, the patient’s age and clinical symptoms are especially suggestive.
2. Hip Dysplasia (e.g., DDH): Typically identified during newborn or infant screening, usually showing acetabular dysplasia on X-ray. Past medical history should be reviewed to rule this out.
3. Slipped Capital Femoral Epiphysis (SCFE): Commonly observed in adolescents, presenting with hip pain or limping, but on imaging, the femoral head typically slips posteriorly and inferiorly. This does not align completely with the main finding of a markedly reduced neck-shaft angle.
Considering the child’s age (10 years old), persistent limping, and restricted hip abduction, along with imaging findings of a markedly decreased femoral neck-shaft angle and characteristic radiographic signs, the most likely diagnosis is Left Developmental Coxa Vara.
If needed, further imaging (e.g., MRI) or additional testing may be performed to rule out secondary causes (such as post-traumatic changes, epiphyseal disorders, or other pathological factors).
1. Therapeutic Strategies:
• Surgical Treatment: For confirmed developmental coxa vara cases accompanied by significant limitation in hip range of motion, pain, or functional impairment, proximal femoral osteotomy is typically recommended to restore the neck-shaft angle to a normal or near-normal range (target Hilgenreiner’s angle < 38°).
• Conservative Treatment: If symptoms are mild, the deformity is not severe, and the Hilgenreiner’s angle is not in the high-risk range, periodic follow-up and physical therapy may be considered to monitor hip function and changes in the femoral neck-shaft angle.
2. Rehabilitation/Exercise Prescription:
• Initial Phase (Postoperative or Acute Phase):
- Primarily protective weight bearing. Use crutches or a walker as instructed to reduce load on the affected hip.
- Perform gentle range-of-motion (ROM) exercises, including hip flexion, extension, and cautious abduction within a pain-free range. Avoid intense pain.
• Intermediate Phase:
- Gradually increase weight-bearing activities. Regularly assess hip strength and ROM, and integrate small-scale lower-limb strengthening exercises (iliopsoas, quadriceps, hamstrings, and hip abductors).
- Each training session may include 2–3 sets of 8–12 repetitions for each exercise, progressively increasing resistance or frequency as tolerated without causing notable hip pain.
• Later Phase:
- Gradually resume normal activity patterns, emphasizing single-leg balance, squats, and standing exercises to improve gait stability and hip control.
- If postoperative correction is successful, running and jumping can be reintroduced in a graded manner under the guidance of a specialist or physical therapist.
• Individualization and Safety:
- Adjust the program according to the child’s skeletal maturity and overall fitness to avoid overtraining, which might lead to reinjury or recurrence of deformity.
- In cases of bone fragility or other comorbidities, ensure adequate calcium and vitamin D intake and closely monitor for pain or discomfort during exercise.
Disclaimer: The above analysis and recommendations are for clinical reference only and do not replace a professional physician’s in-person diagnosis or treatment. If you have any questions or if symptoms worsen, please seek medical attention promptly.
Coxa vara of the left hip
