A long-term follow-up study of the clinical and radiographic outcome of distal trochanteric transfer in Legg-Calvé-Perthes' disease following varus derotational osteotomy

Proximal femoral varus osteotomy for Legg-Calvé-Perthes disease: Do age and lateral pillar classifications influence short-to-mid-term clinical and radiological outcomes?

INTRODUCTION

Proximal femoral varus osteotomy (FVO) is one of the most used treatment methods with acceptable outcomes for Legg-Calvé-Perthes disease (LCPD). We aimed to investigate the influence of age at disease onset and the Lateral Pillar classification on clinical and radiological outcomes of FVO surgery LCPD patients between 6-12years of age.

HYPOTHESIS

Proximal FVO surgery in the early fragmentation phase of LCPD patients led to acceptable clinical and radiographic outcomes in a 3-year follow-up, regardless of preoperative age and Herring type.

MATERIAL AND METHODS

Fifty patients with LCPD (Herring groups B, B/C, and C) who underwent FVO were retrospectively reviewed. We evaluated radiological [center-edge angle, extrusion index, epiphyseal index, acetabular index, articulo-trochanteric distance (ATD)] and clinical [hip abduction range of motion (ROM), Trendelenburg sign, pain, and Harris hip score (HHS)] outcomes with a follow-up of 37.3±10.5months (range: 24-180months). Finally, the overall treatment outcome was assessed using the Stulberg classification.

RESULTS

The ROC curve analysis did not reveal any significant relationship between age and clinical or radiological outcomes, and there was no predictable age cut-off for surgical outcomes (p=0.13). No significant difference was found in Stulberg classification at the follow-up between patients with type B, B/C, and C of the lateral pillar (p>0.05).

DISCUSSION

Our results demonstrated that open-wedge proximal FVO surgery in the early fragmentation phase of LCPD patients led to acceptable clinical and radiographic outcomes in a 3-year follow-up. Each sample of our study was very small and a lot of variables were measured, making this result not adequately strong enough to draw a robust conclusion. However, FVO surgery remains a possible suggestion for patients in the early fragmentation phase, and age and lateral pillar type may not be limiting factors.

LEVEL OF EVIDENCE

IV; therapeutic retrospective cohort.

Incidence of total hip arthroplasty in patients with Legg-Calve-Perthes disease after conservative or surgical treatment: a meta-analysis

PURPOSE

This systematic review and meta-analysis aimed to determine the incidence of total hip arthroplasty (THA) in patients with Legg-Calve-Perthes disease (LCPD) treated conservatively or surgically and factors influencing the incidence of THA.

METHODS

Long-term follow-up studies on the conservative or surgical treatments of LCPD from 1950 to 2021 were conducted using six public databases. Articles were screened by two investigators (PRISMA guidelines), and the quality of the included publications (n = 27) was assessed (MINORS criteria). R version 4.2.1 was used for statistical analysis.

RESULTS

The overall incidences of THA were 6.8% and 5.14% in patients who were treated conservatively and surgically, respectively. At disease onset, the incidences of THA were 6.79% and 6.17% after conservative treatment and surgery in patients aged < seven years, respectively, and 16.97% and 3.61% in patients aged > seven years, respectively. The incidences of THA were 4.91%, 5.19%, and 23.18% in patients who were treated conservatively with ≤ 30, 30-40, and > 40 years of follow-up, respectively, and 3.68%, 3.11%, 9.66%, and 17.92% in patients who were treated surgically with ≤ ten, ten to 20, 20-40, and > 40 years of follow-up, respectively. In patients who received conservative treatment, the incidences of THA were 5.79% and 5.29% in patients with Stulberg I-II and III-V, respectively. In surgically treated patients, the incidence of THA was 0% in Stulberg I-II and 8% in Stulberg III-V.

CONCLUSION

Patients with LCPD had relatively low incidences of THA. The greater the age at disease onset and longer the follow-up, the higher the incidence of THA; however, the Stulberg classification was not directly associated with the incidence of THA.

Relative Femoral Neck Lengthening in Legg-Calvé-Perthes Total Hip Arthroplasty

Background

Total hip replacement (THR) in patients with a history of Legg-Calvé-Perthes disease can be a technically challenging procedure due to the distorted hip morphology. We propose a technique in which THR is preceded by a modified relative femoral neck lengthening (RFNL) procedure. Hereby, we aim to restore the biomechanical parameters.

Methods

Twenty-eight patients underwent RFNL in preparation of a second-stage THR between December 2011 and September 2019. The mean age was 38.1 ± 11.4 years. Radiographs were analyzed for centrotrochanteric distance, lateral displacement of the greater trochanter, and leg length discrepancy to assess the biomechanical restoration. Complication rate, reoperation rate, and patient-reported outcome measures were measured.

Results

Mean centrotrochanteric distance increased from −18.7 ± 6.7 mm preoperatively to 1.9 ± 9.0 mm (P < .001) after RFNL and to 11.4 ± 10.4 mm after THR (P < .001). Mean lateral displacement of the greater trochanter increased from 34.2 ± 8.1 mm preoperatively to 42.4 ± 5.2 mm (P < .001) after RFNL and to 49.9 ± 8.3 mm after THR (P < .001). Leg length discrepancy decreased from 17.5 ± 10.5 mm to 2.7 ± 2.2 mm after THR (P < .001). Mean Harris Hip Score improved from 56.9 ± 17.6 preoperatively to 89.4 ± 10.7 at the latest follow-up (P < .001). Eight patients (8 hips) postponed THR because of sufficient clinical improvement, at a mean follow-up of 4.2 ± 2.1 years. Two hips needed a revision RFNL due to non-union (7.1%), and 1 hip replacement was revised due to a deep infection (5.0%).

Conclusions

RFNL prior to THR in patients with end-stage osteoarthritis following Legg-Calvé-Perthes disease allows for utilizing regular implants with straight access to the femoral canal, with restored biomechanics and restoration of leg length. The prominent overhanging greater trochanter is reduced to prevent postoperative extra-articular impingement.

Morscher Osteotomy Through Surgical Dislocation Approach for True Femoral Neck Lengthening with Greater Trochanter Transposition

BACKGROUND

Young adults presenting with hip pain can be affected by proximal femoral growth disturbances as seen in Legg-Calvé-Perthes disease (LCPD) or as a complication of surgical treatment of developmental dysplasia of the hip (DDH). In 1988, Morscher proposed a novel femoral neck lengthening osteotomy to address these issues. The purpose of this study was to evaluate the effectiveness and safety of the Morscher osteotomy as a procedure to complement the well-documented surgical hip dislocation, to increase femoral offset, to distalize the greater trochanter, and to increase the overall limb length.

METHODS

This study was a retrospective case series from 3 hip-preservation-expert surgeons. Morscher osteotomies performed through a surgical dislocation approach by 3 surgeons between January 2008 and September 2019 were reviewed. Fifteen patients with a median age at surgery of 17 years (range, 13 to 28 years) and a minimum follow-up of 3 months (until union) were included. Surgical indications, clinical findings, comparative radiographic analyses including the change in horizontal femoral offset and the position of the greater trochanter, and complications were assessed.

RESULTS

Surgical indications included DDH and LCPD. The horizontal femoral offset improved in all patients, to a median of 32.5 mm (range, 4 to 46.4 mm). The articular-trochanteric distance increased to >5 mm in all patients. Limb length improved by a median of 11.5 mm (range, 3 to 30 mm). Complementary periacetabular osteotomy was performed in 14 patients. The lateral center-edge angle and the acetabular index improved in patients with an associated periacetabular osteotomy, to a median of 28.2° (range, 9° to 37.7°) and 7.9° (range, 0° to 20°), respectively. Two patients demonstrated osteoarthritis progression from Tönnis stage 0 to stage 1, and 6 patients had a decrease of the joint space. Complications included 1 pulmonary embolism, 1 case of asymptomatic fibrous union of the greater trochanter, and 1 transient sciatic nerve palsy.

CONCLUSIONS

The time-tested Morscher osteotomy indicated for complex proximal femoral reconstruction is effective in increasing horizontal femoral offset, distalization of the greater trochanter, and limb length. Combining the Morscher osteotomy with the versatility of surgical hip dislocation and the improved coverage capacity of periacetabular osteotomy proved complementary in the arsenal of hip preservation.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Conventional Cementless Total Hip Arthroplasty for Hip Osteoarthritis after Distal Trochanteric Transfer: A Report of Two Cases

Distal trochanteric transfer (DTT) has been widely performed to treat developmental dysplasia of the hip or Perthes disease. Total hip arthroplasty (THA) following DTT in patients with hip osteoarthritis is one of the most challenging procedures for hip surgeons, because great care must be taken regarding anatomical abnormalities of the greater trochanter and the soft tissue attached to the greater trochanter. To the best of our knowledge, there are no reports on THA after DTT. We herein report two cases of patients who underwent THA post DTT using cementless components. After THA, both patients developed abduction temporary contraction because of leg length extension and gluteus medius hypertension. However, in both cases, the contraction was reversible within two months and the final clinical result was good. Therefore, THA can be considered an effective and safe choice for treating osteoarthritis after DTT.

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.

Complications After Pediatric Hip Fractures: Evaluation and Management

Pediatric proximal femur fractures are high-energy injuries with predictable and morbid complications. Osteonecrosis of the femoral head is the most common complication with identified risk factors including fracture type, patient's age, degree of displacement, timing to reduction, and stability of fixation. Additional complications include nonunion, coxa vara, and premature physeal arrest. The mainstay of treatment for traumatic pediatric osteonecrosis is hip preservation with total hip arthroplasty being reserved as a salvage procedure. An anatomic fracture reduction and a biomechanically stable construct are critical to prevent both nonunion and osteonecrosis. This review will look at the individual surgical interventions for the management of the associated complications of pediatric proximal femur fractures.

New insights into the biomechanics of Legg-Calvé-Perthes' disease: The Role of Epiphyseal Skeletal Immaturity in Vascular Obstruction

Objectives

Legg–Calvé–Perthes’ disease (LCP) is an idiopathic osteonecrosis of the femoral head that is most common in children between four and eight years old. The factors that lead to the onset of LCP are still unclear; however, it is believed that interruption of the blood supply to the developing epiphysis is an important factor in the development of the condition.

Methods

Finite element analysis modelling of the blood supply to the juvenile epiphysis was investigated to understand under which circumstances the blood vessels supplying the femoral epiphysis could become obstructed. The identification of these conditions is likely to be important in understanding the biomechanics of LCP.

Results

The results support the hypothesis that vascular obstruction to the epiphysis may arise when there is delayed ossification and when articular cartilage has reduced stiffness under compression.

Conclusion

The findings support the theory of vascular occlusion as being important in the pathophysiology of Perthes disease.

Cite this article: M. Pinheiro, C. A. Dobson, D. Perry, M. J. Fagan. New insights into the biomechanics of Legg-Calvé-Perthes’ disease: The Role of Epiphyseal Skeletal Immaturity in Vascular Obstruction. Bone Joint Res 2018;7:148–156. DOI: 10.1302/2046-3758.72.BJR-2017-0191.R1.