Multicenter study for Legg-Calvé-Perthes disease in Japan

Does Flexion Varus Osteotomy Improve Radiographic Findings Compared With Patients Treated in a Brace for Late-onset Legg-Calvé-Perthes Disease?

BACKGROUND

Legg-Calvé-Perthes disease (LCPD) is a childhood hip disease characterized by osteonecrosis of the femoral head. Because severe deformity of the femoral head can cause secondary osteoarthritis in adulthood, progressive collapse should be prevented in children with a necrotic epiphysis. The prognosis of patients with LCPD generally worsens as the age at disease onset increases, and the appropriate treatment for late-onset LCPD remains unclear. Based on the limited effect of nonoperative treatment using a nonweightbearing brace, flexion varus osteotomy (FVO) was introduced in 2010 as an initial treatment for late-onset LCPD in place of brace treatment, which we used in our institution before that time.

QUESTIONS/PURPOSES

We asked, (1) Which treatment, FVO or a nonweightbearing brace, is associated with a lower likelihood of progressive femoral head collapse in children whose diagnosis of LCPD was made at the age of ≥ 8 years and who were followed for a minimum of 3 years after their intervention? (2) What proportion of patients in the brace group had surgery despite the treatment, and what percentage of children in the FVO group had a second operation to remove hardware and/or additional operations?

METHODS

The initial treatment was applied in 181 patients with LCPD between 1995 and 2018 in our institution. Patients whose disease onset was at ≥ 8 years old (late-onset LCPD) with complete clinical and radiologic data were considered potentially eligible. In 2010, treatment for these patients changed from brace treatment to FVO for all patients. A total of 35% (42 of 121) of patients who were treated with a nonweightbearing brace between 1995 and 2009 and 40% (24 of 60) of patients who were treated with FVO between 2010 and 2018 were eligible. Among patients treated with a brace, 21% (nine of 42 patients) were excluded because of hospital transfer (three patients), short-term follow-up (three), the period from onset to the first visit was ≥ 7 months (two), and inability to use the brace because of mental incapacity (one patient). In patients treated with FVO, 12% (three of 24 patients) were excluded (two patients with a period from onset to the first visit ≥ 7 months and one with a comorbidity and multiple-epiphyseal dysplasia). Among the remaining patients, 79% (33 of 42 patients) were classified into the brace group and 88% (21 of 24 patients) were classified into the FVO group for analyses. There were no overlapping patients at the timepoint when the treatment strategy for late-onset LCPD changed. In the FVO group, subtrochanteric osteotomy with 35° to 40° of flexion and 15° to 20° of varus was performed using a locking compression plate for pediatric use. Patient demographics, radiographic parameters, and the assessment of femoral head deformity using the Stulberg classification were compared between the two groups. There was a greater proportion of boys than girls in both groups (brace: 88% and FVO: 86%), and there were no differences in the distribution of genders between the groups (p = 0.82). The right side was more frequently treated in the brace group, but there was no difference in laterality between the groups (brace: 58% right and FVO: 62% left; p = 0.16). There was no difference between groups in the median age at disease onset (9.0 years [range 8.0 to 12.5 years] in the brace group and 9.6 years [range 8.0 to 12.4 years] in the FVO group; p = 0.26). There was no difference between the groups in the period of treatment from onset (1.7 ± 1.9 months in the brace group and 1.5 ± 1.5 months in the FVO group; p = 0.73) or the follow-up period (6.7 ± 2.1 years in the brace group and 6.2 ± 2.1 years in the FVO group; p = 0.41). The LCPD stage at the first visit was assessed using the modified Waldenström classification. The intraobserver and interobserver values of the modified Waldenström classification, evaluated using kappa statistics, were excellent (kappa value 0.89 [95% CI 0.75 to 0.97]; p < 0.01) and good (kappa value 0.65 [95% CI 0.43 to 0.87]; p < 0.01). The radiographic degree of collapse at the maximum fragmentation stage was assessed using the lateral pillar classification. The intraobserver and interobserver reliabilities of the lateral pillar classification were excellent (kappa value 0.84 [95% CI 0.73 to 0.94]; p < 0.01) and excellent (kappa value 0.83 [95% CI 0.71 to 0.94]; p < 0.01). The degree of femoral head deformity at the most recent follow-up examination was compared between the groups in terms of the Stulberg classification, in which Classes I and II were classified as good and Classes III through V were classified as poor. The intraobserver and interobserver reliabilities of the Stulberg classification were good (kappa value 0.74 [95% CI 0.55 to 0.92]; p < 0.01) and good (kappa value 0.69 [95% CI 0.50 to 0.89]; p < 0.01). The evaluators were involved in the patients' clinical care as part of the treating team.

RESULTS

Good radiographic results (Stulberg Class I or II) were obtained more frequently in the FVO group (76% [16 of 21 patients]) than in the brace group (36% [12 of 33 patients]), with an odds ratio of 5.6 (95% CI 1.7 to 18.5; p < 0.01). In the brace group, a subsequent femoral varus osteotomy was performed in 18% (six of 33) of patients with progressive collapse and hinge abduction, and implant removal surgery was performed approximately 1 year after the first procedure. This traditional varus osteotomy was occasionally performed in patients who were considered for conversion from nonoperative treatment before 2009 because FVO had not yet been introduced. In the FVO group, all patients (n = 21) had a second procedure to remove the implant at a mean of 10.5 ± 1.2 months postoperatively. Additional procedures were performed in 24% (five of 21) of patients, including a second FVO for progressive collapse (one patient), guided growth for a limb length discrepancy (one patient), and flexion valgus osteotomy for coxa vara in patients with a limb length discrepancy (three patients).

CONCLUSION

Our historical control study found that FVO may increase the possibility of obtaining good radiographic results (Stulberg Class I or II) compared with brace treatment for patients with late-onset LCPD, although surgical interventions after the first and second implant removal procedures may be indicated. Surgeons can consider FVO if they encounter patients with late-onset LCPD, which is a challenging condition. A larger study with long-term follow-up is needed to confirm the efficacy of FVO.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Comparative effectiveness of treatment modalities in severe disease: systematic review and network meta-analysis of observational studies

PURPOSE

There are several treatment modalities for Legg-Calvé-Perthes disease (LCPD), self-limiting, avascular osteonecrosis of the femoral head in children. Most treatments focus on containment of the weakened femoral head, but there is no consensus on the best modality for severe LCPD. Therefore, we compared the effectiveness of all treatment modalities for severe LCPD.

MATERIALS AND METHODS

We searched the PubMed, Embase, and Scopus up until July 2021 for studies that investigated LCPD treatment effectiveness. A network meta-analysis was performed to examine the comparative effectiveness in terms of the ability to achieve radiographic spherical congruity of the hip joint after skeletal maturity. The risk ratio (RR) and 95% confidence interval (CI) of each treatment modality were estimated from both direct and indirect evidence. Treatment ranking was based on Surface Under the Cumulative Ranking curve (SUCRA).

RESULTS

A total of 857 studies were identified and 34 comparative studies with 3718 affected hips comparing seven different LCPD treatment modalities were included. Compared with symptomatic treatment, combined osteotomy was the most effective modality (RR = 1.47, 95% CI 0.90 to 2.42, SUCRA = 0.8), followed by femoral varus osteotomy (RR = 1.31, 95% CI 1.06 to 1.60, SUCRA = 0.7), and Salter innominate osteotomy (RR = 1.25, 95% CI 0.95 to 1.65, SUCRA = 0.6).

CONCLUSIONS

Combined osteotomy is the most effective procedure in terms of improving the spherical congruity of the hip joint in severe LCPD patients. However, the superiority of operative treatments seems to be limited to patients older than eight years old.

Towards a definition of Ancient Rare Diseases (ARD): Presenting a complex case of probable Legg-Calvé-Perthes Disease from the North Caucasian Bronze Age (2200-1650 cal BCE)

OBJECTIVE

This study discusses the challenges and possibilities of establishing a definition for Ancient Rare Diseases (ARD) in a probable case of Legg-Calvé-Perthes Disease (LCPD) from the Bronze Age cemetery Kudachurt 14, situated in the Northern Caucasus.

MATERIALS

We investigated the skeletal remains of a male aged 35-45 years at death. For comparison we examined other males buried at Kudachurt 14 (n = 24) and reviewed 22 LCPD cases from the paleopathological literature.

METHODS

We use macroscopic as well as osteometric examination methods and imaging techniques.

RESULTS

The morphology of the left hip joint corresponds to skeletal characteristics for LCPD. Co-occurring osteochondrosis dissecans, femoral anteversion, and atrophy of the left femoral shaft suggest a complex disease course.

CONCLUSIONS

Modern criteria of rare diseases applied on ancient skeletal remains are either non-transferable or require completion. We conclude that rarity is dynamic, etiological uncertainty has to be accepted, and the respective socioeconomic context is crucial. Degree of disability and level of sociomedical investment are not defining criteria for ARD.

SIGNIFICANCE

Dating 2200-1650 cal BCE, this study currently presents the earliest case of probable LCPD. This is the first attempt to transform modern characteristics of rare diseases for establishing a paleopathological concept of ARD.

LIMITATIONS

As this study is limited to LCPD, our conclusions are not directly applicable to other ARD in question.

SUGGESTIONS FOR FURTHER RESEARCH

More focused paleopathological research on skeletal populations from different cultures and time periods is needed, enabling an evolutionary perspective on the comparability of ancient, modern and future rare diseases.

Legg-Calvé-Perthes disease in a patient with Bardet-Biedl syndrome: A case report of a novel MKKS/BBS6 mutation

This article reports a girl with Bardet-Biedl syndrome (BBS) having a novel causative mutation who developed Legg-Calvé-Perthes disease (LCPD). There exists a possibility that the prognosis of LCPD had been adversely affected by the concomitant BBS.

Characteristics and diagnostic factors associated with fresh lumbar spondylolysis in elementary school-aged children

PURPOSE

We often encounter elementary school-aged children with fresh lumbar spondylolysis and non-union of bone. They may have factors that impede healing, and treatment outcomes need improvement. The purpose of this study was to investigate elementary school-aged patients with fresh lumbar spondylolysis and to identify characteristics that can aid in prompt diagnosis and proper therapy.

METHODS

We retrospectively compared the characteristics of fresh lumbar spondylolysis in elementary school-aged children with those of older patients. We included patients aged 6-18 years with lower back pain and evidence of bone marrow oedema of lumbar pedicles on magnetic resonance imaging (MRI). The elementary school-aged group (group E) included 100 patients aged 6-12 years, and the senior group (group S) included 251 patients aged 13-18 years. We recorded patient sex, duration of lower back pain, injured site (lumbar level, unilateral/bilateral), presence of contralateral pars defect with evidence of high signal change on MRI (short tau inversion recovery), presence of spina bifida occulta (SBO), and follow-up treatment interruption rate.

RESULTS

One-third of the patients in group E were female, and there was an even smaller proportion of females in group S. L5 lumbar spondylolysis was more common in group E. The treatment interruption rate was lower in group E. L5 SBO and contralateral pars defect were more common in group E.

CONCLUSION

L5 lumbar spondylolysis, L5 SBO, and contralateral pars defect were important diagnostic factors in elementary school-aged patients. Identification of these characteristics will aid in prompt diagnosis and proper therapy.

Clinical outcomes of conservative treatment with a non-weight-bearing abduction brace for Legg-Calvé-Perthes disease

BACKGROUND

Treatment with a brace is the first choice as conservative treatment via the containment method for Legg-Calvé-Perthes disease (LCPD). The purpose of this study is to evaluate clinical outcomes and influential factors of conservative treatment with the non-weight-bearing abduction brace for LCPD.

METHODS

One hundred thirty hips in 130 patients were examined in this study. The mean age at onset was 7.0 years (3.3-12.4 years) and the mean follow-up period was 8.4 years (4.1-17.6 years). The extent of necrosis and lateral collapse of the femoral head were evaluated using the Catterall classification and the lateral pillar classification, respectively. Radiological outcome was assessed as good (classes I and II), fair (III), and poor (IV), according to the modified Stulberg classification.

RESULTS

Radiographic outcome at final follow-up was good in 82 hips (63%), fair in 40 hips (31%), and poor in 8 hips (6%). Multinomial logistic regression analysis showed that major influential factors for good outcomes were as follows: age at onset, lateral pillar classification, and Catterall classification. From the receiver operating characteristic curve, the cut-off value for age at onset was 8.4 years old to obtain good outcomes. Hips with Catterall group I and II and lateral pillar group A and B had significantly better results.

CONCLUSION

Patients younger than 8.4 years old at onset with lateral pillar group A or B or Catterall group I or II showed good outcomes with a non-weight-bearing abduction brace for LCPD. These results show that alternative treatment, such as surgery, may be another option for patients who are not included in the above groups.

Skeletal immaturity, rostral sparing, and disparate hip morphologies as biomechanical causes for Legg-Calvé-Perthes' disease

Legg-Calvé-Perthes' (Perthes') disease is a developmental disease of the hip joint that may result in numerous short and long term problems. The etiology of the disease remains largely unknown, but the mechanism is believed to be vascular and/or biomechanical in nature. There are several anatomical characteristics that tend to be prevalent in children with Perthes' disease, namely: skeletal immaturity, reduced height, and rostral sparing. We present an overview of the literature, summarizing the current understanding of the pathogenesis, particularly related to how the formation of the vasculature to the femoral epiphysis places children aged 5-8 at a higher risk for Perthes' disease, how skeletal immaturity and rostral sparing could increase the probability of developing Perthes' disease, and how animal models have aided our understanding of the disease. In doing so, we also explore why Perthes' disease is correlated to latitude, with populations at higher latitudes having higher incidence rates than populations closer to the Equator. Finally, we present five hypotheses detailing how Perthes' disease could have a biomechanical cause. Clin. Anat. 29:759-772, 2016. © 2016 Wiley Periodicals, Inc.

Transient synovitis of the hip: a comprehensive review

Transient synovitis is a benign, self-limiting condition that is diagnosed after the exclusion of more serious causes of acute hip pain in children. Although its etiology remains unclear, it is largely believed to be viral in nature. Transient synovitis typically presents as an acute onset of thigh pain with a limp or an unwillingness to bear weight. It can be distinguished from similar conditions by the absence of fever, as well as unremarkable bloodwork (WBC, CRP, ESR), radiographs, and hip aspiration. Conservative treatment and observation are the mainstay of management. Resolution of symptoms generally occurs by 1 week and may be accelerated by NSAIDs. Although numerous papers have emerged over the years with an effort to advance our understanding, many questions remain about its pathomechanics, etiology, and how to exclude other more serious conditions that present similarly.

Racial and geographic factors in the incidence of Legg-Calvé-Perthes' disease: a systematic review

Legg-Calvé-Perthes' disease (Perthes' disease) is a childhood osteonecrosis of the hip for which the disease determinants are poorly understood. In this review, the authors identify studies of Perthes' disease incidence published up to December 2010 and make denominator populations comparable in order to allow meaningful between-study evaluation. Incidence rates and confidence intervals were determined, and, where appropriate, denominator populations were obtained from national statistical offices. Poisson regression was used to determine the influence of race and geography. The review included 21 studies that described 27 populations in 16 countries, with 124 million person-years of observation. The annual incidence among children under age 15 years ranged from 0.2 per 100,000 to 19.1 per 100,000. Race was a key determinant, with East Asians being least affected and whites most affected, though data were insufficient to consider incidence among blacks (for South Asians vs. East Asians, incidence rate ratio = 2.9, 95% confidence interval (CI): 2.4, 3.5; for whites vs. East Asians, incidence rate ratio = 8.8, 95% CI: 8.2, 9.6). Latitude was a strong predictor of disease, even after adjustment for race. Each 10° increase in latitude was associated with an incidence increase of 1.44 (95% CI: 1.30, 1.58) times. While much of the international variation appears to be a function of race, latitude demonstrates a strong association. This observation may offer new epidemiologic insights into the determinants of Perthes' disease.

The epidemiology and demographics of legg-calvé-perthes' disease

The etiology of Legg-Calvé-Perthes' disease (LCPD) is unknown. There are many insights however from epidemiologic/demographic information. A systematic medical literature review regarding LCPD was performed. The incidence ranges from 0.4/100,000 to 29.0/100,000 children <15 years of age. There is significant variability in incidence within racial groups and is frequently higher in lower socioeconomic classes. The typical age at presentation ranges from 4 to 8 years (average 6.5 years), except for children from the Indian subcontinent (average 9.5 years). There is a mild familial component. The children demonstrate impaired growth in height, skeletal age, and birth weight. This impaired growth coincides with an age appropriate reduced somatomedin A activity and decreased levels of IGF. LCPD can be associated with abnormalities in the coagulation cascade, including an increase in factor V Leiden mutation, low levels of protein C and/or S, and decreased antithrombin activity. There is decreased turnover in type I collagen and synthesis of type III collagen, as well as reduced levels of urinary glycosaminoglycans in the active phases of the disorder. Subtle abnormalities in the opposite hip and other minor/major congenital defects are reported. Children with LCPD are active and score abnormally in certain standardized psychological tests.

The epidemiology and etiology of Perthes disease

The incidence of Perthes disease varies markedly both between countries and within countries down to a local level. The disease is more common in white than in Asian or black African children. The disease is associated with deprivation; with a steep disease gradient across social class groups. This epidemiology alongside the lack of concordance in twins suggests a strong environmental etiology, with little evidence to suggest a genetic predisposition. Children are frequently short, with a growth pattern described as "rostral-sparing". A propensity to associated congenital anomalies suggests an intrauterine cause.

Degenerative osteoarthritis after Perthes' disease: a 36-year follow-up

BACKGROUND

Although the prognosis of Perthes' disease at skeletal maturity is considered favorable, little is known about the long-term results after middle age.

METHODS

We retrospectively analyzed the radiographic and functional outcomes of 67 patients (70 hips) who had been treated for Perthes' disease. Of these patients, 28 patients (29 hips) were evaluated using JOA (Japanese Orthopaedic Association) score and radiographs at follow-up (Group 1), 39 patients (41 hips) were evaluated by a postal questionnaire (Group 2). The mean follow-up period was 36.1 years. The mean age at follow-up was 43.1 years.

RESULTS

Group 1, good radiographic results (Stulberg class I or II) were achieved in 59% of hips. No osteoarthritis (Tönnis Grade 0) was observed in only 48% of hips. The clinical results were good (JOA score ≥ 70) in 79% of hips. Disturbance of walking ability and activities of daily living was little. The Tönnis grade and JOA score declined after 40 years of age. All patients older than 50 years showed severe osteoarthritis. The severity of osteoarthritis correlated significantly with age at follow-up. Group 2, the clinical results were good (JOA score ≥ 56) in 76% of hips. In both groups, no patient had undergone total hip arthroplasty. Younger age at diagnosis (<8 years) correlated significantly with a better result. The JOA score correlated significantly with age at follow-up.

CONCLUSION

Patients who were treated for Perthes' disease have a risk of osteoarthritis and a clinically poor outcome after the age of 40-50 years.

Legg-Calve-Perthes disease and risks for cardiovascular diseases and blood diseases

OBJECTIVE

We hypothesized that patients with Legg-Calvé-Perthes disease (LCPD) might have higher risks of cardiovascular and blood diseases.

METHODS

A total of 3141 patients, 2 to 15 years of age, with LCPD diagnosed between 1965 and 2005 were identified with the Swedish Inpatient Register. A total of 15 595 individuals without LCPD were selected randomly from among the Swedish general population, with matching according to year of birth, age, gender, and region of residence. Cox proportional-hazard regression analyses, with adjustment for socioeconomic index, were used to estimate relative risks. The patients also were compared with their same-gender siblings.

RESULTS

Patients with LCPD had a hazard ratio (HR) of 1.70 (95% confidence interval [CI]: 1.39-2.09) for cardiovascular diseases, compared with individuals without LCPD. The point estimate was slightly higher among subjects >30 years of age at the follow-up (HR: 2.10 [95% CI: 1.52-2.91]). There were statistically significantly higher risks for blood diseases, including anemias and coagulation defects (HR: 1.41 [95% CI: 1.07-1.86]), which were more pronounced among subjects >30 years of age at the follow-up (HR: 2.70 [95% CI: 1.50-4.84]). Patients also had statistically significantly higher risks of hypertensive disease (HR: 2.97 [95% CI: 1.87-4.72]) and nutritional anemia (HR: 2.92 [95% CI: 1.58-5.40]). Analyses using siblings as the comparison group showed consistent results for cardiovascular diseases.

CONCLUSION

The results are consistent with the hypothesis that an insufficient blood supply to the femoral head, attributable to vascular pathologic conditions, is involved in the pathogenesis of LCPD.

Acute non-traumatic hip pathology in children: incidence and presentation in family practice

BACKGROUND

The differential diagnosis of children with acute non-traumatic hip pathology varies from quite harmless conditions such as transient synovitis of the hip to more severe problems like Perthes' disease, slipped capital femoral epiphysis (SCFE) and life-threatening conditions such as septic arthritis of the hip.

OBJECTIVE

To provide population-based data on symptom presentation and incidence rates of non-traumatic acute hip pathology in family practice.

METHODS

We analysed data from a large national survey of family practice (104 practices), which was carried out by the Netherlands Institute for Health Services Research (NIVEL) in 2001. We included all children aged 0-14 years. Incidence rates were calculated by dividing the total number of cases (numerator) by the average study population at risk (denominator).

RESULTS

Our study population consisted of 73 954 children aged 0-14 years, yielding 68 202 person-years. These children presented with 101 episodes of acute non-traumatic hip pathology. The presenting feature in 81.5% of the children was pain, in 8.6% limping and 9.9% presented with both symptoms. Only 27% of the participating family practitioners (FPs) reported whether the child had a fever. The incidence rate for all acute non-traumatic hip pathology was 148.1 per 100 000 person-years, and for transient synovitis, this was 76.2 per 100 000 person-years.

CONCLUSION

In family practice, most children with acute non-traumatic hip pathology present with pain as the initial symptom. FPs need to be more aware that fever is the main distinguishing factor between a harmless condition and a life-threatening condition. Transient synovitis is the diagnosis with the highest incidence rate.

Arthrodiatasis for the treatment of Perthes' disease

It is hypothesized that the interruption of the blood supply is an important factor causing femoral head osteonecrosis in the early stages of Legg-Calvé-Perthes disease. Currently, treatment by containment is recommended to direct and guide remodeling of the softened femoral head as it evolves from fragmentation through ossification. The goal of this study was to show the results of arthrodiatasis to induce height recovery of the femoral head and to achieve true ambulatory nonweight-bearing containment. Forty-two patients younger than 8 years with a diagnosis of Perthes' disease were studied. Twenty-three patients (9 class B and 14 class C according to Herring's classification) were treated with an articulated distraction technique and 19 patients (11 class B and 8 class C) were treated conservatively as a control group. Arthrodiatasis or articulated distraction of the hip combines off-loading of muscles and body forces with distraction of the joint space by means of an external fixator that crosses the hip joint. Radiologically, 21 patients (91%) had satisfactory results and 2 (9%) had unsatisfactory results. Clinically, the results were good in 21 patients (92%), fair in 1 (4%), and poor in 1 (4%). In patients treated conservatively, 14 patients (72%) had satisfactory results and 5 (28%) had unsatisfactory results. Clinically, 71% had good results, 17% had fair, and 12% had poor. We conclude that hip joint containment by articulated arthrodiatasis (plus adductors and psoas minimal tenotomy surgery) is an effective method in the management of Perthes' disease in patients younger than 8 years, classified B and C, and associated with a highly reduced range of abduction. Restoration of clinical abnormalities and satisfactory radiological parameters are achieved in high percentages.