Theoretical study of subluxation in early Legg-Calvé-Perthes disease

Avascular necrosis after femoral neck fracture in children and adolescents: poor prognosis and risk factors

INTRODUCTION

Avascular necrosis (AVN) after femoral neck fracture (FNF) is a rare and severe paediatric condition, but only few studies described its prognosis and risk factors. The present study aimed to evaluate the outcomes and independent factors for poor prognosis of AVN after FNF in children and adolescents.

METHOD

This retrospective study included children and adolescents with AVN after FNF who received conservative treatment (CT group) or non-vascularized bone grafting (NVBG group) between 2000 and 2018. The primary outcomes were the risk of hip arthritis (Tönnis grade) and hip deformity risk (Stulberg classification). All patients were followed for at least two years to assess AVN progression.

RESULTS

Study included 81 patients. In the CT group, 23/43 patients (53.4%) developed hip arthritis, and 24/43 patients (55.8%) showed hip deformity. In the NVBG group, 23/38 patients (60.5%) developed hip arthritis, and 34/38 patients (89.5%) had a hip deformity. The multivariable analysis indicated that NVBG surgery had no significant effect on the outcomes. Post-treatment femoral head collapse (P = 0.05, OR = 3.80, 95% CI = 1.01-14.29) and post-treatment hip subluxation (P = 0.01, OR = 2.85, 95% CI = 2.31-129.56) were independent risk factors for severe hip arthritis. Post-treatment femoral head collapse (P < 0.01, OR = 7.64, 95% CI = 3.23-18.04) and pre-treatment hip subluxation (P = 0.02, OR = 7.33, 95% CI = 1.44-37.41) were independent risk factors for severe hip deformity.

CONCLUSION

Neither CT nor NVBG have demonstrated superiority regarding long-term outcomes in patients with AVN after FNF. Upon the disease progression to severe collapse with subluxation and severe arthritis, further hip preservation attempts could be futile.

Surgical Treatments for Legg-Calvé-Perthes Disease: Comprehensive Review

Background

Legg-Calvé-Perthes disease (LCPD) is a common public health problem that usually occurs between the ages of 4 and 8 years, but it can occur between the ages of 2 and 15 years. This condition occurs due to the interruption of blood supply to the femoral head. Up to now, different surgical and nonsurgical treatments, including femoral varus osteotomy, innominate osteotomy, pelvic osteotomies, triple osteotomy, Chiari osteotomy, and shelf acetabuloplasty, have been suggested for noncontainable LCPD hips.

Objective

The aim of this comprehensive review was to investigate the various surgical techniques used for LCPD.

Methods

An advanced electronic search of the English-language literature was performed from October 8 to 14, 2020. The electronic databases PubMed, MEDLINE, Web of Science, Embase, Ovid, and Google scholar were searched using appropriate search terms. A manual search of references also was performed. After retrieving the studies, duplicates were removed, and the remining studies were screened based on the title, abstract, and full text. The quality of the selected articles was assessed, and the required data were extracted from eligible articles.

Results

A total of 22 studies were included in the review. Based on the results of the reviewed studies, there are three main factors that influence the treatment outcomes in patients with Perthes disease. These factors are onset age, femoral head involvement severity, and treatment method. The disease has a poor prognosis in children over 8 years old, but this group of patients can also benefit from advanced surgical methods. In patients aged less than 6 years, the disease has a generally good prognosis, but in those aged between 6 and 8 years, its prognosis is variable. Thus, the need for surgical intervention requires close observation of signs. Once any head signs are observed, dynamic arthrography is beneficial before choosing the treatment approach.

Conclusions

This review provides clinicians with a brief guideline for the treatment of patients with LCPD.

Does Early Proximal Femoral Varus Osteotomy Shorten the Duration of Fragmentation in Perthes Disease? Lessons From a Prospective Multicenter Cohort

BACKGROUND

The prognosis of Legg-Calvé-Perthes disease (LCPD) is dependent upon several factors, with the length and severity of the fragmentation stage among the most important. Previous retrospectively collected data from a single center have suggested that early proximal femoral varus osteotomy (PFO) may shorten the length of fragmentation and allow 34% of patients to bypass fragmentation altogether resulting in less femoral head deformity. The purpose of this study was to validate these findings in a prospectively collected multicenter cohort.

METHODS

Patients with LCPD treated with early PFO (during Waldenström stage I) were prospectively followed with serial radiographs at 3-month intervals until a minimum of 2-year follow-up. Waldenström stages and lateral pillar class were determined by mode assessments from 3 pediatric orthopaedic surgeons. The duration of fragmentation was defined as the interval between the first radiographs demonstrating features of stage IIa and stage IIIa. "Complete" bypass was defined as the absence of stage IIa or IIb findings on sequential radiographs with no development of femoral head deformity or collapse. "Partial" bypass was defined as the absence of advanced features of fragmentation and femoral head collapse (stage IIb).

RESULTS

Forty-six patients (80% male individuals) with initial stage LCPD and a mean age of 8.2±1.2 years were identified. The weighted kappa statistics for Waldenström staging and lateral pillar classifications showed excellent (0.833) and substantial (0.707) agreement, respectively. Ninety-eight percent of patients (45/46) underwent some period of fragmentation lasting between 91 and 518 days; the median duration was 206 days (interquartile range, 181 to 280). One patient (2%) bypassed fragmentation completely; 8 patients (17%) demonstrated partial bypass. Patients who completely or partially bypassed fragmentation experienced significantly less severe lateral pillar collapse (P=0.016) and shorter fragmentation duration (P=0.001).

CONCLUSIONS

In this prospective multicenter cohort, we found a lower rate of fragmentation bypass than previously reported. Nonetheless, our data support the previous contention that early PFO may shorten fragmentation and minimize collapse in LCPD compared with historical controls. Further study with larger cohorts and a more rigorous definition of what constitutes bypass is warranted to clarify the effect of early PFO on the reparative biology of LCPD.

LEVEL OF EVIDENCE

Level IV-therapeutic study.

Single Versus Combined Procedures for Severely Involved Legg-Calvé-Perthes Disease

BACKGROUND

The concept of containment as an effective approach to reduce the risk of femoral head deformity has been questioned because modest results have been achieved after nonoperative and operative treatments for severely involved Legg-Calvé-Perthes disease. Several reports have shown the limited effectiveness of some conventional single procedures. However, there is limited data on the effectiveness of combined procedures.

METHODS

The surgical group comprised 77 patients (mean age 8.3 y) and involved 79 hips. The average follow-up term was 9.5 years. Sixty-five patients were unilaterally involved and 12 patients were bilaterally involved (although 10 of the latter patients only received surgery on 1 hip). Among patients, 28 hips were classified as Herring class B/C border (>8 y old) and 51 hips were Herring class C. The 79 hips were divided into 2 treatment groups for further analysis: group 1, single procedures (femoral varus osteotomy) (n=47); group 2, combined procedures [femoral varus osteotomy+Dega (Pemberton) osteotomy] (n=32).

RESULTS

Using Stulberg classification I and II (acceptable outcome), the final outcome was statistically significant for group 2 (21 hips, 65.6%) compared with group 1 (18 hips, 38.3%) (P=0.031). The average remodeling efficacy, defined as the change in caput index between preoperation and postoperation, was better in group 2 (12.7%) than in group 1 (3.9%) (P=0.005). The acetabulum-head index and α-angle were also statistically significant in group 2 than in group 1 at the last follow-up. Clinical evaluations were statistically significant in group 2 compared with group 1.

CONCLUSIONS

Both clinically and radiologically, the combined procedure group demonstrated significantly better outcomes with accelerated remodeling in both the severely affected femoral heads and the acetabula compared with the single procedure group. With this procedure, we anticipate the increased likelihood of preventing or delaying coxarthroses in adulthood.

LEVEL OF EVIDENCE

Level III-therapeutic study.

Legg-Calvé-Perthes disease

Current knowledge of the causes and risk factors of Legg-Calvé-Perthesdisease (LCPD) does not allow effective preventive strategies. The outcome in adulthood is usually good. Hip osteoarthritis rarely develops before 50 years of age. The risk of osteoarthrosis depends chiefly on the final degree of joint incongruence. Age at onset and the lateral pillar classification are the two main outcome predictors and serve to guide the surgical indications based on the studies by Herring's group. Non-operative treatment is not effective. In contrast, femoral varus osteotomy and Salter's innominate osteotomy provide good outcomes. In severe forms, however, combining these two techniques or performing a triple pelvic osteotomy seem preferable. Surgery is now performed considerably less often than in the past, as it is effective only in patients with lateral pillar group B or B/C disease with onset after eight years of age. In other situations, therapeutic abstention is recommended.

Advanced Containment With Triple Innominate Osteotomy in Legg-Calve-Perthes Disease: A Viable Option Even in Severe Cases

BACKGROUND

Legg-Calve-Perthes disease (LCPD), in its severe form, remains a challenge. More recent classifications, particularly the modified Elizabethtown classification, have highlighted the chronologic stage of LCPD and its effect on surgical outcome. Hip severity and age of disease onset have also been shown to be powerful determinants of outcome. This study was performed to determine whether disease stage, disease severity, or patient age, are absolute indicators of whether a patient can benefit from surgical containment with triple innominate osteotomy (TIO).

METHODS

All patients with LCPD treated with TIO between 1995 and 2011 were collected. Only those patients with a minimum of 2-year radiographic follow-up and no previous or concomitant femoral realignment surgery were included. Fifty-four patients (56 hips) met our inclusion criteria. The modified Elizabethtown classification was used to classify disease stage as early (<IIb) or late (≥IIb). Catterall and lateral pillar classifications were used to classify disease severity, and the Stulberg classification was utilized for radiographic outcome, defined as good (I/II) or poor (III/IV/V).

RESULTS

Fifty-one males and 3 females with a mean chronological age at surgery of 8.2±1.8 years were included (2 bilateral cases). Mean follow-up was 72.8±30.2 months. There was no significant difference in the proportion of Stulberg good versus poor outcomes when comparing hips that were graded as early or late stage (P=0.842), or Catterall I and II versus III and IV (P=0.304). Although not statistically significant, patients with lateral pillars B and BC (P=0.076) and patients who were aged 8.0 and younger trended toward doing better compared with lateral pillar C and over age 8.0 (P=0.085), respectively.

CONCLUSIONS

Radiographic results demonstrate that good outcomes are not entirely dependent on the stage of disease in LCPD when containment is performed with TIO. As expected, TIO appears to be more effective in younger patients with less severe disease. We conclude that even severely involved LCPD hips, independent of age, should be offered surgical containment. The failure rate in this group is higher, as expected, but many achieve good results and there are treatment methods available to those who fail containment.

LEVEL OF EVIDENCE

Level IV.

A probable case of Legg-Calvé-Perthes disease in Warring States-era China

Reports of Legg-Calvé-Perthes disease (LCPD) in the paleopathological literature are rare. Here, the authors present a probable case of LCPD, which presents as abnormal morphology of the proximal femur. The condition was observed in an individual of the Warring States period in Shaanxi Province, China, and the morphology involves a "mushroom head" deformity of the proximal right femur and an enlarged acetabulum, along with a contralateral tibia, talus, and navicular that are enlarged and demonstrate periosteal new bone formation. The authors consider tuberculosis, septic arthritis, trauma, slipped capital femoral epiphysis, and Legg-Calvé-Perthes disease in a differential diagnosis. The authors conclude that the most likely diagnosis for the deformity is Legg-Calvé-Perthes disease. Bony changes in the hip joint and contralateral lower leg suggest that the individual had an altered gait because of the condition.

Early outcomes of one-stage combined osteotomy in Legg-Calve´-Perthes disease

BACKGROUND

Legg-Calve´-Perthes disease (LCPD) is an idiopathic avascular necrosis of the femoral head. There are multiple approaches to the treatment of LCPD ranging from conservative management to a wide variety of surgical methods. Conservative management necessitates extreme degrees of abduction in an orthosis for a longer period of time which further jeopardize capital femoral head vascularity. Surgical containment methods are used in cases where it is desirable. Initial surgical containment methods are varus or varus-derotational osteotomy of the proximal femur or an innominate osteotomy as described by Salter and other pelvic osteotomies. The purpose of this study was to describe the early results of containment methods by one-stage combined osteotomy (femoral varus osteotomy and Salter innominate osteotomy) in patients with severe LCPD.

MATERIALS AND METHODS

23 children were operated in the age group of 4-9 years for LCPD by one-stage combined osteotomy procedure between January 2005 and June 2012. There were 19 boys and 4 girls, left hip involved in 10 cases and right in 13 cases. Preoperatively, they were classified according to Catterall, Joseph's stage and lateral pillar (LP) classification. Postoperatively, clinical results were evaluated in accordance with Ratliff classification and radiological assessment was made by Mose's index, modified Stulberg classification and Epiphyseal extrusion index.

RESULTS

Seventeen hips were Catterall group III, 6 in group IV and all had two or more "head-at-risk" signs. There were 2 patients with stage IIA, 15 were in stage IIB and 6 were in stage IIIA as classified by Joseph's stage of disease. According to LP classification, 11 patients were group B, 3 were group B/C and 9 were in group C. At an average followup of 5.4 years (range 2-9.5 years), the clinical results were good in 12, fair in 9 and poor in 2. According to Mose scale, 8 patients had good results, 13 fair results and 2 had poor results. Based on modified Stulberg classification, there were 10 patients in group A, 11 in group B and 2 in group C. The average preoperative extrusion index was 23.6% which improved postoperatively to 9.5% at latest followup.

CONCLUSIONS

The surgical treatment of LCPD with the best expected outcome is still a challenge. Advanced containment methods by one-stage combined osteotomy can be considered as an alternative treatment where femoral head subluxation or deformity which makes containment difficult or impossible by more conventional methods.

Outcomes of Combined Shelf Acetabuloplasty with Femoral Varus Osteotomy in Severe Legg-Calve-Perthes (LCP) Disease: Advanced Containment Method for Severe LCP Disease

BACKGROUND

Standard treatments may provide adequate containment in mild to moderate Legg-Calve-Perthes disease (LCPD), but they can be problematic in more severe cases. The purpose of this study was to report the results of combined shelf acetabuloplasty with femoral varus osteotomy in severe LCPD.

METHODS

We reviewed 12 patients who had undergone combined shelf acetabuloplasty with femoral varus osteotomy. The indications for this type of operation were: (1) above 8 years of age at clinical onset; (2) massive femoral epiphysis involvement (Catterall group 4, lateral pillar C); (3) femoral head lateral subluxation on the anteroposterior radiograph; and (4) impending hinged abduction on preoperative magnetic resonance imaging or arthrography. The mean age was 9.3 years (range, 8 to 10.8 years). The patients were clinically evaluated with Iowa hip score and leg length discrepancy at the final follow-up. Radiographic outcome was assessed using the Stulberg classification to evaluate femoral head sphericity. The presence of osteoarthritis was evaluated by the Tonnis classification. Correlation analysis was conducted to analyze the preoperative factors that were strongly associated with patients' outcomes.

RESULTS

The mean follow-up period was 10.1 years (range, 7.1 to 13.2 years). Functional grade was excellent in all patients at last follow-up (mean, 92; range, 82 to 99). The mean leg length discrepancy after skeletal maturity was 0.9 cm (range, 0 to 1.7 cm). There were no significant complications or need for additional surgery. Radiographically, 92% of patients reached satisfactory outcomes: Stulberg grade I, 0 cases; Stulberg grade II, 4 cases (34%); Stulberg III, 7 cases (58%), Stulberg IV, 1 case (8%); and Stulberg V, 0 cases. There was no osteoarthritis by Tonnis classification.

CONCLUSIONS

The surgical outcomes for combined shelf acetabuloplasty with femoral varus osteotomy in severe LCPD patients over 8 years old are comparable with other advanced surgical methods. In the cases of severe disease that match our inclusion criteria, our containment method could be another treatment option.

Triple innominate osteotomy for Legg-Calvé-Perthes disease in children: does the lateral coverage change with time?

BACKGROUND

Triple innominate osteotomy (TIO) is one of the modalities of surgical containment in Legg-Calvé-Perthes disease (LCPD). However, overcoverage with TIO can lead to pincer impingement.

QUESTIONS/PURPOSES

We therefore asked (1) whether TIO contained the femoral head in Catterall Stages III and IV of LCPD; (2) whether the center-edge (CE) angle, acetabular roof arc angle (ARA), and Sharp's angle changed during the growing years; and (3) what percentage of patients had radiographic evidence of pincer impingement beyond a minimum followup of 3 years.

METHODS

We identified 19 children who had 20 TIOs performed for Catterall Stages III and IV LCPD. Two blinded observers assessed sequential radiographs. Each observer made two sets of readings more than 2 weeks apart. Femoral head extrusion index, CE angle of Wiberg, ARA, and Sharp's angle were measured. Minimum followup was 3 years to document continued acetabular growth (mean, 3.8 years; range, 3-7 years).

RESULTS

All patients exhibited femoral head containment at last followup. Eleven of 20 hips demonstrated no radiographic evidence of pincer morphology beyond a minimum followup of 3 years (mean, 3.8 years). Patients with CE angle corrected to 44° or less and an ARA of greater than -6° after TIO did not demonstrate a pincer morphology at last followup.

CONCLUSIONS

TIO resulted in femoral head containment in all cases. Lateral acetabular coverage changed during the growing years in all patients. Surgical correction beyond 44° of CE angle and -6° of ARA should be avoided to prevent pincer morphology later.

Pathophysiology and new strategies for the treatment of Legg-Calvé-Perthes disease

Legg-Calvé-Perthes disease is a juvenile form of idiopathic osteonecrosis of the femoral head that can lead to permanent femoral head deformity and premature osteoarthritis. According to two recent multicenter, prospective cohort studies, current nonoperative and operative treatments have modest success rates of producing a good outcome with a spherical femoral head in older children with Legg-Calvé-Perthes disease. Experimental studies have revealed that the immature femoral head is mechanically weakened following ischemic necrosis. Increased bone resorption and delayed new bone formation, in combination with continued mechanical loading of the hip, contribute to the pathogenesis of the femoral head deformity. Biological treatment strategies to improve the healing process by decreasing bone resorption and stimulating bone formation appear promising in nonhuman preclinical studies.

Advanced containment methods for Legg-Calvé-Perthes disease: results of triple pelvic osteotomy

BACKGROUND

Although surgical containment has become a mainstay for the treatment of Legg-Calvé-Perthes (LCP) disease; traditional operations (varus osteotomy of femur, Salter osteotomy) have certain limitations, sometimes resulting in a prolonged limp or inadequate containment. This paper presents the surgical method and results of triple pelvic osteotomy for containment treatment of LCP disease.

METHODS

This retrospective review of 39 children (40 hips; age 5 to 13 y) with LCP disease treated with triple pelvic osteotomy (1995 to 2005) included preoperative lateral pillar assessment and other measurements. Final follow-up films (minimum 3 y, range 3 to 9 y) were assessed using the modified Stulberg classification. Clinical follow-up evaluation assessed limp, limb-length inequality, range of motion, and activity level.

RESULTS

Twenty-one (53%) hips were graded as lateral pillar B and 19 (48%) were lateral pillar C. Four patients required further treatment before the final follow-up. At final follow-up, 42% had a good outcome (Stulberg I/II), 47% had a fair outcome (Stulberg III), and 11% had a poor outcome. Thus, 89% of patients had satisfactory (good or fair) results. There was a significant difference in outcome based on the preoperative lateral pillar, with B hips more likely to have a good outcome (65%) compared with lateral pillar C hips (12.5%) (P=0.002). There were no lateral pillar B patients with a poor outcome. Seventeen percent of the lateral pillar C patients more than or equal to age 8 had a poor outcome compared with 50% being more than age 8 with a poor outcome. Four patients (3 lateral pillar C, 1 lateral pillar B) required further surgery.

CONCLUSIONS

Triple pelvic osteotomy resulted in maintenance of head shape in lateral pillar B patients of all ages and in younger lateral pillar C patients. Lateral pillar C patients over age 8 were more difficult to treat, however, we still advise containment for these cases because methods are now available to deal with containment failure. Triple pelvic osteotomy is an effective treatment method for LCP patients with lateral pillar B disease and younger patients with lateral pillar C disease. This method provides effective containment, which allows prolonged remodeling while avoiding the limitations of femoral varus osteotomy (limp, short limb) and Salter osteotomy (incomplete containment).

LEVEL OF EVIDENCE

Level IV.

Perthes disease: a survey of management amongst members of the British Society for Children's Orthopaedic Surgery (BSCOS)

The treatment of Legg-Calvé-Perthes disease remains controversial. The aim of this survey was to ascertain the current management strategies of this condition amongst UK paediatric orthopaedic surgeons, with particular regard to containment procedures in the fragmentation phase. Questionnaires were distributed at the January 2006 meeting of the British Society for Children's Orthopaedic Surgery (BSCOS) and was posted to all absent members. The results showed a great deal of variability not only in the treatment of Perthes disease, but also in the decision-making processes. Consideration must now be given to a carefully constructed national multi-centre prospective randomised controlled study into the optimum management of this disease.