The fate of the capital femoral physis and acetabular development in developmental coxa vara

Proximal femoral valgus osteotomy for the treatment of developmental coxa vara: a systematic review of the literature

Background

Developmental Coxa Vara (DCV) consists on a pathological reduction in head-shaft angle (HSA) and increased femoral retroversion. Several case series reported outcomes on proximal femoral valgus osteotomy (PFVO), but no evidence synthesis had been conducted. This systematic review aimed to (1) analyze success rate and complications, (2) report the degree of correction according to the HSA and the Hilgenreiner Epiphyseal Angle (HEA), compare success rate and degree of correction of subtrochanteric (SVO) vs intertrochanteric (IVO) osteotomy, and (4) difference in success rate and correction between patients in which an internal (IF) or external fixation (EF) technique was used.

Methods

Four databases (PubMed, Scopus, Embase, and Cochrane Database of Systematic Reviews) were searched until February 20th, 2024 according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Studies presenting outcomes on PFVO for DCV with >2 years follow-up and >5 patients were included. Review articles, language other than English and coxa vara secondary to other conditions were excluded. Study quality was evaluated through MINORS criteria.

Results

10 case series (level of evidence IV) were located for a total of 153 patients and 192 hips. Baseline results were as follows: male/female ratio was 1.45, mean age at surgery was 6.7 ± 1.5 and follow-up 5.1 ± 5.5 years. Overall success rate was 88.8%, with failure considered as any indication to revision surgery. Complications included loss of correction (10.9%), deep (1.0%) or superficial wound infection (2.6%). Revision surgery was performed in 18 hips (9.4%). Average correction was measured through HSA (preoperative 94.6 ± 8.1, postoperative 134.4 ± 10.2, change 38.2 ± 7.5°, p < 0.001) and HEA (preoperative 71.9 ± 5.5, postoperative 31.7 ± 5.7°, change 33.7 ± 10.5°, p < 0.001). Success rate was similar between osteotomy techniques (SVO: 91.0%; IVO: 94.1%; p = 0.48) and fixation strategy (IF: 85.4%; EF 95.8%; p = 0.096).

Conclusions

PFVO presented satisfactory results for the treatment of DCV, with similar outcomes concerning the osteotomy site and fixation technique used. HSA and HEA correction were correlated to PFVO success rate. However, coxa vara is a tridimensional deformity, thus other parameters such as posterior sloping angle, mechanical axial deviation and proximal femoral offset should be included in future studies.

Adult Idiopathic Bilateral Coxa Vara with Hip Osteoarthritis Treated with Bilateral Proximal Femur Osteotomy: A Case Report

CASE

We reported a case of a 25-year-old woman with idiopathic bilateral coxa vara who had initial presentation of hip osteoarthritis. She was later treated with bilateral subtrochanteric valgus osteotomy. A good functional outcome was recorded without nonunion or deformity recurrence. The arthritis of the hips also decelerated.

CONCLUSIONS

Coxa vara first diagnosed in adulthood was relatively uncommon, and the cause in this present case was uncertain. Subtrochanteric valgus osteotomy seemed to be a suitable treatment for this case.

Analyzing risk factors for recurrence of developmental coxa vara after surgery

PURPOSE

To evaluate the risk factors for developmental coxa vara (DCV) recurrence following valgus osteotomy of the proximal femur.

METHODS

We retrospectively reviewed records of 32 DCV patients (46 hips) treated surgically (2005 to 2012). Recurrence-related factors, including age at initial surgery, side, sex, fixation methods, diagnosis of coxa vara, premature capital femoral physeal closure and postoperative Hilgenreiner epiphyseal (HE) angle, head-shaft (HS) angle, medial femoral offset and posterior slope angle (PSA) were analyzed.

RESULTS

At 4.7-year mean follow-up, 12 hip deformities recurred (26%). Postoperative HE angle > 41° and negative offset were statistically significant univariate and multivariate risk factors for the deformity recurrence. Increased PSA was common preoperatively, which accounted for 59% of hips. Postoperative PSA > 20° was associated with a high recurrence rate in the univariate analysis. Age was another univariate risk factor for the recurrence. Recurrence rate was 52% in the < 6.5-year age group versus 4% in the > 6.5-year age group. Other factors were not statistically significantly related to recurrence.

CONCLUSION

DCV is a 3D deformity. To prevent recurrence, HE angle should be restored to < 41° in the coronal plane. Sagittal malalignment (abnormal PSA) should be corrected concurrently, so that, the direction of surgical correction is along the true deformity plane. During valgus osteotomy, the distal fragment should be lateralized to maintain a normal mechanical axis.

LEVEL OF EVIDENCE

IV.

Long-term Outcomes of Operative and Nonoperative Treatment of Congenital Coxa Vara

BACKGROUND

Congenital coxa vara (CCV) is a rare hip condition with few long-term studies. The purpose of this study was to assess clinical, radiographic, and functional outcomes after operative and nonoperative treatment of CCV, assess reliability of radiographic parameters, and investigate risk factors for recurrence after surgery.

METHODS

Retrospective review was performed of all CCV patients treated at 1 institution from 1980 to 2010. In addition, patients were recalled for additional follow-up x-rays, modified Harris Hip Score (mHHS), and gait analysis. Radiographic measurements [neck-shaft angle (NSA), head-shaft angle (HSA), Hilgenreiner-epiphyseal angle (HEA), and femoral neck length (FNL)] were assessed for reliability using intraclass correlation coefficients. Multivariate analysis was performed to identify risk factors for recurrence after surgery.

RESULTS

Forty-six hips in 32 patients were reviewed. Mean age at presentation was 5.4±4.9 years. Mean follow-up was 11.8±5.8 years. Valgus proximal femoral osteotomy was performed in 27 hips (20 patients). Initial deformity was greater in the operative group (NSA 90±17 degrees, HEA 68±19 degrees) versus nonoperative patients (NSA 122±19 degrees, HEA 34±14 degrees) (P<0.0001), but radiographic outcomes were similar at follow-up. Most nonoperative hips had normal FNL growth rates (80%), but resolution of varus NSA occurred in only 21%. In contrast, 56% of operative hips showed decreased FNL growth rates. Interobserver reliability was excellent for HEA (0.98), NSA (0.90), and FNL (0.89), and good for HSA (0.79). Repeat osteotomy was performed in 6 cases (22%). No significant predictors for recurrence were identified. At long-term follow-up for recalled patients, 72% had significantly abnormal gait, and 50% had fair-poor functional outcomes (mHHS<79).

CONCLUSIONS

Valgus osteotomy corrects severe deformity in CCV with improved clinical and radiographic outcomes. HEA and NSA are the most reliable radiographic measurements of proximal femoral deformity in CCV. Recurrence is not uncommon, but no predictors were identified. Many patients have persistent gait abnormalities and functional impairment at long-term follow-up, regardless of prior treatment.

LEVEL OF EVIDENCE

Level III-retrospective cohort.

Pauwels' osteotomy for surgical correction of infantile coxa vara

Infantile coxa vara can be corrected by valgus osteotomies, but recurrence is high. Achieving an Hilgenreiner epiphyseal angle (HEA) of 40° or less prevents recurrence. In this study, Pauwels' osteotomy is stabilized using a rigid method of fixation. The aim of the study is to confirm previous reports regarding the correction of the physeal inclination to 40° or less to prevent recurrence. Thirty-one hips with infantile coxa vara were subjected to an intertrochanteric Y-shaped valgus osteotomy. In 27 hips, the HEA was corrected to 40° or less and none had a recurrence. This study confirms previous recommendations regarding the correction of HEA to 40° or less to avoid recurrence.

Acetabular changes in coxa vara

The purpose of this study was to define the acetabular changes associated with coxa vara and determine how these acetabuli differ from those of a normal hip. Charts and radiographs of 33 patients with coxa vara with a mean age of 6 years (range, 2-15 years) were retrospectively reviewed. The diagnosis was developmental coxa vara in 21 patients and congenital femoral deficiency in 12. Radiographic measurements, including acetabular index, sourcil slope, center edge angle, migration index, and medial joint space, were compared with those of 29 hips in the control group. The inclination of the acetabulum or acetabular slope (as measured by the acetabular index and sourcil slope) was significantly increased in the hips with coxa vara as compared with those in the control group. Both parameters have a statistically significant inverse correlation with the degree of varus, ie, the greater the varus of the proximal femur, the greater the upsloping of the acetabulum. Joint subluxation, as measured by the center edge angle, migration index, and medial joint space, showed little difference from that of control subjects.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Coxa vara: surgical outcomes of valgus osteotomies

Since the 1950s, valgus-producing femoral osteotomy has been the preferred treatment for significant coxa vara. Despite well-performed surgeries, the literature cites recurrence rates of 30-70%. The present study reviews our past 15 years of surgical experience for coxa vara; 26 children with 37 affected hips were retrospectively evaluated for outcome following valgus osteotomy. Both congenital and acquired types of coxa vara were included. Overall recurrence rate following valgus osteotomy was 50%. Age at time of surgery, type of surgery, and type of implant and etiology were found to have no bearing on recurrence. However, if Hilgenreiner's epiphyseal angle was corrected to < 38 degrees, 95% of children had no recurrence of varus. In contrast, head-shaft angle was found not to be a reliable indicator of appropriate correction. Only six of 37 hips required pelvic osteotomy (five Pemberton, one Chiari) for dysplasia, and four of these had developmental dysplasia of the hip as the underlying etiology for their coxa vara. However, if the proximal femur was corrected and maintained before age 10, 83% of children had excellent acetabular depth, spherical congruency, relief from pain, and correction of Trendelenburg gait at latest follow-up.