Effect of greater trochanteric epiphysiodesis after femoral varus osteotomy for lateral pillar classification B and B/C border Legg-Calvé-Perthes disease: A retrospective observational study

Predictors of Persistent Limp Following Proximal Femoral Varus Osteotomy for Perthes Disease

INTRODUCTION

One of the most popular containment procedures for Legg-Calvé-Perthes disease (LCPD) is proximal femur varus osteotomy (PFO). While generally successful in achieving containment, PFO can cause limb length discrepancy, abductor weakness, and (of most concern for families) a persistent limp. While many studies have focused on radiographic outcomes following containment surgery, none have analyzed predictors of this persistent limp. The aim of this study was to determine clinical, radiographic, and surgical risk factors for persistent limp 2 years after PFO in children with LCPD.

METHODS

A retrospective review of a prospectively collected multicenter database was conducted for patients aged 6 to 11 years at disease onset with unilateral early-stage LCPD (Waldenström I) who underwent PFO. Limp status (no, mild, and severe), age, BMI, and pain scores were obtained at initial presentation, 3-month, and 2-year postoperative visits. Preoperative and follow-up radiographs were used to measure traditional morphologic hip metrics including acetabular index (AI), lateral center-edge angle (LCEA), and femoral neck-shaft angle (NSA). Univariate analysis as well as multivariate logistic regression models were used to analyze factors associated with mild and severe limp at the 2-year visit.

RESULTS

A total of 95 patients met the inclusion criteria, and of these 50 patients underwent concomitant greater trochanter apophysiodesis (GTA) at the time of PFO. At the 2-year visit, there were 38 patients (40%) with a mild or severe limp. Multivariate logistic regression revealed no significant radiographic factors associated with a persistent limp. However, lower 2-year BMI and undergoing GTA were associated with decreased rates of persistent limp regardless of age (P<0.05). When stratifying by age of disease onset, apophysiodesis appeared to be protective against any severity of limp in patients aged 6 to 8 years old (P= 0.03), but not in patients 8 years or older (P= 0.49).

CONCLUSIONS

Persistent limp following PFO is a frustrating problem that was seen in 40% of patients at 2 years. However, lower follow-up BMI and performing a greater trochanter apophysiodesis, particularly in patients younger than 8 years of age, correlated with a lower risk of postoperative limp.

Radiographic outcome after greater trochanteric epiphysiodesis in patients with Perthes disease

Purpose

Legg-Calvé-Perthes disease often leads to greater trochanteric overgrowth, which negatively affects the biomechanics of the hip joint. This study aimed to evaluate the physiologic growth of the greater trochanter and the effectiveness of greater trochanteric epiphysiodesis radiographically.

Methods

Retrospectively, 46 children (33 male, average age at greater trochanteric epiphysiodesis 8 ± 1.3 years) with unilateral Legg-Calvé-Perthes disease undergoing greater trochanteric epiphysiodesis with screws and curettage of the epiphysis were included. On radiographs of the pelvis pre- and postoperatively (mean follow-up 3.5 years), trochanteric height, articulotrochanteric distance, and center-trochanter distance were determined and compared to the unaffected side. Reference values for the physiological development of trochanteric height, articulotrochanteric distance, and center-trochanter distance over time were established.

Results

Greater trochanteric epiphysiodesis reduced trochanteric growth by 29% measured by trochanteric height, but only statistically significant in the group "<8 years" (p = 0.02). Regression analysis revealed inhibition of trochanteric growth of 0.92 mm/year. Both articulotrochanteric distance and center-trochanter distance of the affected and unaffected side converged during the follow-up period: articulotrochanteric distance of the affected hip increased (preop: 11.2 ± 7 mm, maturity: 18.5 ± 10 mm; p < 0.01) compared to no change on the unaffected side (preop: 19.3 ± 5 mm, maturity: 18 ± 6 mm; p = 0.69). Center-trochanter distance of the affected hip stayed unchanged (preop: (-7.9) ± 7 mm, maturity: (-7.8) ± 9 mm; p = 0.13). On the unaffected side, center-trochanter distance became negative (preop: 0.9 ± 6 mm, maturity: (-6.5) ± 5 mm; p < 0.001). Measured by articulotrochanteric distance and center-trochanter distance, 31.8% achieved an optimal result.

Conclusion

Greater trochanteric epiphysiodesis has a positive effect on greater trochanter growth and therefore on hip anatomy. Further studies must show whether these positive effects also result in biomechanical and functional benefits.

Level of evidence

level III.

Does transepiphyseal drilling and closure of the greater trochanter in early Legg-Calve-Perthes disease improve natural history?

PURPOSE

There is no consensus regarding treatment of Legg-Calve-Perthes disease (LCPD). The most common sequel of the disease is coxa breva and overgrowth of the greater trochanter (GT). Our purpose was to examine the effectiveness of transepiphyseal drilling combined with closure of the GT apophysis in patients with LCPD.

METHODS

During 2013-2018, we treated 16 consecutive cases of LCPD. Average age was 7.5 (range 6-10) years; nine patients were in early fragmentation, five in late fragmentation and one in reossification stages. Treatment protocol included hip arthrography, percutaneous drilling of the femoral head epiphysis, percutaneous tenotomy of adductor longus and epiphysiodesis of the GT apophysis.

RESULTS

Mean follow-up was 38 months. One patient was lost to follow-up. All patients had a limp prior to surgery. However, at latest follow-up, 10/15 patients had no limp, 11 patients had substantial improvement in hip range of motion. On radiographs, nine patients had Stulberg type 1-2, one type 3 and five type 4-5. There was no change in the epiphysio-trochanteric distance in any patient. Eight out of nine patients treated in the early fragmentation stage had good clinical and radiographic outcome. Most patients treated in late fragmentation stage had Stulberg 4-5 hip and required additional procedures.

CONCLUSIONS

Based on our preliminary experience, our protocol can be effective in the treatment of patients with LCPD in the initial or early fragmentation stages by improving the clinical and radiographic outcomes of the disease. This minimally invasive approach does not compromise any future treatment options.

LEVEL OF EVIDENCE

IV.

Can Rigid Femoral Nailing Be Used for Pediatric Femoral Shaft Fracture in Children 8 to 10 Years? Use of RIN in Patients With Femoral Shaft Fracture

BACKGROUND

The treatment modalities for pediatric femoral shaft fractures are determined by their age, weight, and fracture pattern. Rigid intramedullary nailing (RIN) is usually recommended for patients >11 years of age, and elastic intramedullary nailing (EIN) has been used for patients under 10 years. However, little is known about the use of RIN in patients aged 8 to 10 years. We examined the differences in patients with femoral shaft fractures who were treated with EIN or RIN in terms of (1) fracture healing; (2) changes of anatomic parameters; and (3) related complications.

METHODS

We retrospectively reviewed 54 patients between 8 and 10 years of age, with femoral shaft fractures, who were treated with either EIN or RIN between 2011 and 2020. Lateral trochanteric entry was used for RIN procedure. The mean follow-up period was 26.4 months (range, 6 to 113 mo). There were 17 patients in the EIN group and 37 patients in the RIN group. The mean age at the time of surgery was 1 year younger in the EIN group ( P <0.01). The mean weight of the patient was significantly heavier in the RIN group compared with the EIN group.

RESULTS

Complete union of the fracture was achieved slightly faster in the RIN group at 3.4 months compared with 3.7 months in the EIN group ( P =0.04). There were no clinically significant changes of the anatomic parameters in either group, including neck shaft angle and articulotrochanteric distance. There was no evidence of avascular necrosis at the time of final follow-up for either group. There were no significant differences in postoperative complications between the groups.

CONCLUSION

RIN using lateral trochanteric entry is a feasible surgical option for femoral shaft fractures in patients 8 to 10 years of age that are heavier than 40 kg or with unstable fracture patterns.

LEVEL OF EVIDENCE

Level III, retrospective cohort study. See the Guidelines for Authors for a complete description of levels of evidence.

Isolated Trochanteric Descent and Greater Trochanteric Apophyseodesis Are Not Effective in the Treatment of Post-Perthes Deformity

BACKGROUND

Greater trochanteric apophyseodesis and isolated trochanteric descent seek to prevent abductor weakness in patients with a hip deformity because of Legg-Calvé-Perthes disease; however, no studies have evaluated radiographic findings or abductor strength in children treated with these procedures.

QUESTIONS/PURPOSES

(1) Do children with Waldenström Stage III Legg-Calvé-Perthes disease treated with either isolated greater trochanteric descent or isolated greater trochanteric apophyseodesis achieve improved radiographic findings (Stulberg classification or neck-shaft angle) compared with those who underwent no surgical treatment? (2) Do children treated with one of those procedures achieve greater abductor strength than those who did not have surgery?

METHODS

Between 2006 and 2010, we treated 89 children with Waldenström Type III Legg-Calvé-Perthes disease (reossification). Of these, 27.9% (12 patients) underwent greater trochanteric descent, 25.6% (11 patients) underwent greater trochanteric apophyseodesis, and 46.5% (20 patients) did not have surgery. During that time, the decision to perform either apophyseodesis or trochanteric descent was made by the surgeon based on the subjective appearance of remaining growth from the greater trochanter. Nonsurgical management was chosen by the parents of the patients after the risks and benefits of surgery were discussed. During greater trochanteric descent, the greater trochanter was osteotomized and fixed distally with two 7.0-mm screws. During greater trochanteric apophyseodesis, the physis was identified fluoroscopically, and the lateral half of the growth plate was drilled. Nonoperative treatment involved serial clinical and radiographic evaluations every 3 to 6 months. All children in all groups were available for follow-up at a minimum of 6 years. The median follow-up durations for children undergoing greater trochanteric descent, greater trochanteric apophyseodesis, and control cohorts were 6.6 years (range 6.0-8.2 years), 6.5 years (range 6.1-9.2 years), and 7.4 years (range 6.0-9.1 years), respectively. On presentation, each patient's affected hip was classified according to the Stulberg classification by the operating surgeon and an orthopaedic surgeon not involved in the child's care. The neck-shaft angle was measured for each patient before surgery and at the final follow-up examination. Abductor strength was assessed by a pediatric orthopaedic fellow and a physical therapist with the patient in the lateral decubitus position. Each patient was given a muscle strength score on a scale of 0 to 10 points, per a modification of the Medical Research Council scale to allow for a narrower range. We had 80% power to detect an 8° difference in the neck-shaft angle between the greater trochanteric apophyseodesis and nonoperative management cohorts. A sample size of 6.8 patients per cohort would be necessary to detect the above endpoint.

RESULTS

With the numbers available, we found no differences among the groups in the proportion of patients with Stulberg Class 2 femoral heads (two of 12 patients in the isolated trochanteric descent group, three of 11 in the isolated trochanteric apophyseodesis group, and two of 20 who did not undergo surgery; p = 0.46). Likewise, there were no differences among the three groups in terms of the neck-shaft angle at a minimum of 6 years of follow-up (122° ± 6°, 119° ± 7°, and 126° ± 8° in the isolated trochanteric descent, isolated trochanteric apophyseodesis, and nonoperative groups, respectively). There were no differences among the groups in term of the median abductor strength test result: seven of 10 (range 6-8), six of 10 (range 6-8), and six of 10 (range 6-10; p = 0.34).

CONCLUSION

Because neither isolated greater trochanteric descent nor greater trochanteric apophyseodesis alone had an effect on hip morphology or abductor strength in children with sequellae of Legg-Calvé-Perthes disease, we conclude these types of extraarticular surgery are ineffective. Therefore, we no longer perform isolated trochanteric descent or apophyseodesis.

LEVEL OF EVIDENCE

Level III, therapeutic study.