Srp Arh Celok Lek. 2011 Nov-Dec; 139(11-12): 834-7

Femoroacetabular impingement is an undesirable contact between acetabular rim and femoral neck and presents abnormality of proximal femoral part and acetabulum, as well. Two forms may appear: cam impingement and pincer impingement. Femoroacetabular impingement related to Legg-Calvé-Perthes disease may be caused by various reasons, as the consequence of the disease itself, and as the consequence of its treatment. Coxa magna deformity (large femoral head and neck) and coxa brevis deformity (shortened femoral neck) may produce cam femoroacetabular impingement during hip flexion. After the disease, the flattened femoral head (coxa plana) may persist. Chiari pelvic osteotomy is the only treatment option for such femoral head deformity. Acetabular labrum squeezed continuously between the femoral head and the non-articular part of the cut iliac bone lead to cam femoroacetabular impingement, as well. If Salter or triple pelvic osteotomy is used that may cause a very large iatrogenic acetabular retroversion, we can also refer to radial type pincer femoroacetabular impingement. Treatment of Legg-Calvé-Perthes disease should be conducted according to the natural course of the disease and prognosis. Treatment should start on time, well before a crushed femoral head develops, because it is the easiest way to establish hip spherical congruency at the end of treatment. This is the best option to prevent secondary hip arthrosis caused by femoroacetabular impingement or by insufficient head coverage at the end of remodelling. In each case of delayed hip pain, followed by a limited range of movements, femoroacetabular impingement should be taken into consideration, confirmed, and treated by some of the available therapeutic methods.

Clin Orthop Relat Res. 2012 Jan 24;
Young ML, Little DG, Kim HK

BACKGROUND: The rationale for using bisphosphonate (BP) therapy for Legg-Calvé-Perthes disease (LCPD) is the potential to prevent substantial femoral head deformity during the fragmentation phase by inhibiting osteoclastic bone resorption. However, it is unclear whether BP therapy decreases femoral head deformity. QUESTIONS/PURPOSES: In this systematic review, we answered the following questions: (1) Does bisphosphonate (BP) therapy decrease femoral head deformity and improve pain and function in LCPD or other juvenile osteonecrotic conditions? And (2) does BP therapy decrease femoral head deformity in experimental studies of juvenile femoral head osteonecrosis? METHODS: We searched the literature from 1966 to 2011 for clinical and experimental studies on BP therapy for juvenile femoral head osteonecrosis. Studies specifically addressing clinical and/or radiographic/histologic outcomes pertaining to pain and function and femoral head morphology were analyzed. RESULTS: Three Level IV clinical studies met our inclusion criteria. Only one study initiated BP therapy during the precollapsed stage of osteonecrosis and reported prevention of femoral head deformity in nine of 17 patients. All studies noted subjective improvements of pain and gait in patients treated with intravenous BPs. Of the eight experimental studies reviewed, seven reported reduced femoral head deformity and six found better preservation of trabecular framework in animals treated with BPs. CONCLUSIONS: Clinical evidence lacks consistent patient groups and drug protocols to draw definitive conclusions that BP therapy can decrease femoral head deformity in juvenile osteonecrotic conditions. Experimental studies suggest BP therapy protects the infarcted femoral head from deformity, but it lacks bone anabolic effect. Further basic and clinical research are required to determine the potential role of BPs as a medical treatment for LCPD.

Gait Posture. 2012 Jan 11;
Westhoff B, Martiny F, Reith A, Willers R, Krauspe R

Current follow-up- and outcome-evaluations of Legg-Calvé-Perthes disease (LCPD) are based on subjective measures of function, clinical and radiological parameters. The objective of this study was to evaluate the sagittal plane kinematics and the effect on hip joint loading on the affected hip in children with LCPD. MATERIALS AND METHODS: Computerized gait analysis was performed in 49 LCPD patients aged ≥5 years with unilateral hip involvement. Sagittal plane kinematics and kinetics were compared to a group of healthy children (n=30). RESULTS: Kinematics: a significantly increased anterior tilt and range of motion (ROM) of the pelvis combined with a marked reduction of the extension of the involved hip joint compared to the control group was observed. The increased ROM of the contralateral hip results from increased maximum flexion. Power generation: overall significantly decreased on the involved side during florid stage. Global hip function: significantly reduced hip flexor index of the involved hip; 46.2% of the patients in advanced stage, although having no significant changes in kinematics - except increased anterior pelvic tilt - had a pathologic HFI. CONCLUSION: Sagittal plane hip function is significantly impaired in florid and advanced LCPD. The results of this study will lead to further investigations into whether this development can be prevented by conservative or operative treatment thus improving function and long-term prognosis.

Am J Epidemiol. 2012 Feb 1; 175(3): 159-66
Perry DC, Machin DM, Pope D, Bruce CE, Dangerfield P, Platt MJ, Hall AJ

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.

Neurol Sci. 2012 Jan 6;
Savasta S, Ruggieri M, Pavone P, Praticò AD, Polizzi A, Beluffi G, Pavone V

The co-occurrence of microcephaly and Legg-Calvè-Perthes disease (LCPD) in members of the same family has been previously recorded only in two Hungarian brothers. To study the clinical and radiological phenotype in a (second) family with LCPD and microcephaly, clinical, X-ray and MRI follow-up study of two Albanian siblings aged 8 and 11 years, were made. Both siblings had primary microcephaly, seizures and mild-to-moderate mental retardation. At head imaging the boy was found to have skull asymmetry, partial lack of frontal lobe development and partial agenesis of corpus callosum and the girl had a complex brain malformation consisting in thickening of the fronto-temporal cortex, colpocephaly, increased curvature of the Sylvian fissure, elevated tentorium with mild hypoplasia of the cerebellar vermis and dilated cisterna magna. In addition, the brother had ADHD and the sister minor eye anomalies mainly consisting in epicanthic folds and pale bilateral (temporal) optic disk. We recorded (and documented for the first time by brain MRI) a second family with familial co-occurrence of LCPD and microcephaly and the first occurrence of complex brain anomalies in the context of a small head circumference. The present report could encourage the observation of similar cases.

Anim Genet. 2012 Feb; 43(1): 112-3
Starr-Moss AN, Nowend KL, Alling KM, Zepp EJ, Murphy KE

Clin Orthop Relat Res. 2011 Dec 23;
Hsu JE, Baldwin KD, Tannast M, Hosalkar H

BACKGROUND: The evidence supporting continued use of shelf acetabuloplasty in Legg-Calvé-Perthes disease (LCPD) is not well-defined, and there is controversy regarding the long-term benefits related to clinical and functional improvement. QUESTIONS/PURPOSES: Our goals were to determine whether shelf arthroplasty for LCPD (1) prevents the onset of early osteoarthritis; (2) improves pain, ROM, activity, and functional outcomes; (3) maintains or improves femoral head containment, sphericity, and congruency; (4) changes the acetabular index; and (5) is associated with a low rate of complications. METHODS: We performed a systematic review of the medical literature from 1966 to 2009 using the search terms Perthes, shelf procedure, and acetabuloplasty. We excluded reports using multiple/combined treatment methods and those not clearly stratifying outcomes. Thirteen studies met the criteria. There were no Level I studies, one Level II prognostic study, five Level III therapeutic studies, and seven Level IV studies. Mean followup ranged from 2.6 to 17.9 years. RESULTS: Only one study reported progression to early osteoarthritis in one patient. We found no evidence for improvement in ROM and continued pain relief at long-term followup. Mean decrease in lateral subluxation ratio was 13% to 30%, demonstrating an improvement in femoral head containment. Mean acetabular cover percentage improved 16% to 38%, and mean acetabular and center-edge angles improved 4° to 14° and 8° to 33°, respectively. There were no reports of any major complications after the procedure. CONCLUSIONS: While radiographic measurements indicate improved coverage of the femoral head after shelf acetabuloplasty for LCPD, available evidence does not document the procedure prevents early onset of osteoarthritis or improves long-term function.

J Pediatr Orthop B. 2011 Dec 17;
Froberg L, Christensen F, Pedersen NW, Overgaard S

The purpose was to compare radiographic parameters with a sex-matched and age-matched control group at the onset of disease and at skeletal maturity. The study comprised 143 patients with Legg-Calvé-Perthes disease, treated using a Thomas splint. Wiberg's centre-edge angle and the acetabular index angle were applied. The age at diagnosis was 6.6 years with no difference between boys and girls. At the time of diagnosis, the centre-edge angle was decreased from 18° in the control group to 10° in the affected hip. The age at follow-up was 16 (SD 2) years for the boys and 15 (SD 3) years for the girls. At the time of skeletal maturity, the centre-edge angle was decreased and the acetabular index angle increased in the affected hip and the nonaffected hip in Stulberg class III/IV/V hips compared with the control group. Initially radiographic changes only occur on the affected hip. At skeletal maturity both hips show radiographic changes.

Int Orthop. 2011 Dec 2;
Svehlík M, Kraus T, Steinwender G, Zwick EB, Linhart WE

PURPOSE: Legg-Calvé-Perthes disease (LCP) severely limits the range of hip motion and hinders a normal gait. Loading of the hip joint is a major consideration in LCP treatment. The aim of this study was to evaluate gait patterns in LCP and identify gait modifications to decrease the load on the affected hip. METHODS: Forty children with unilateral LCP were divided into three groups based on the time base integral of the hip abductor moments during single stance on the affected side acquired during instrumented 3D gait analysis. X-rays of the affected hip were classified according to Herring and Catterall. RESULTS: Children in the "unloading" group spontaneously adopted a Duchenne-like gait with pelvis elevation, hip abduction and external rotation during single support phase. The "normal-loading" group showed pelvis elevation with a neutral hip position in the frontal plane. In the "overloading" group the pelvis dropped to the swinging limb at the beginning of stance accompanied by prolonged hip adduction. The time base integral of the hip abductor moments during single stance correlated positively with the X-ray classifications of Herring and Catterall, hip abduction angle and age. Older children preferred to walk in hip adduction during single stance, had more impaired hips and tended to overload them. CONCLUSION: The hip overloading pattern should be avoided in children with LCP. Gait training to unload the hip might become an integral component of conservative treatment in children with LCP.

Clin Orthop Relat Res. 2011 Nov 29;
Hosalkar H, Munhoz da Cunha AL, Baldwin K, Ziebarth K, Wenger DR

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. LEVEL OF EVIDENCE: Level IV, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Clin Orthop Relat Res. 2011 Nov 29;
Shore BJ, Novais EN, Millis MB, Kim YJ

BACKGROUND: Hip deformity secondary to Legg-Calvé Perthes disease (LCPD) may result in femoroacetabular impingement (FAI) and ultimately osteoarthritis. Observations made with the surgical hip dislocation approach have improved our understanding of the pathologic mechanics of FAI. However, owing to concerns about complications related to the vascularity, the role of surgical hip dislocation in the treatment of healed LCPD remains controversial. QUESTIONS/PURPOSES: We present an algorithm to treat deformities associated with healed LCPD and asked (1) whether femoral head-neck osteochondroplasty and other procedures performed with the surgical hip dislocation approach provide short-term clinical improvement; and (2) is the complication rate low enough to be acceptable. METHODS: We retrospectively reviewed 29 patients (19 males, 10 females; mean age, 17 years; range, 9-35 years) with symptomatic LCPD between 2001 and 2009. All patients underwent a surgical hip dislocation approach and femoral head-neck osteochondroplasty and 26 patients had 37 additional procedures performed. Clinical improvement was assessed using the WOMAC index. The minimum followup was 12 months (mean, 3 years; range, 12-70 months). RESULTS: WOMAC scores improved at final followup (8 to 4 for pain, 21 to 13 for function, and 4 to 2 for the stiffness subscales). No patients had osteonecrosis, implant failure, deep infection, or nonunion. Three patients underwent THA at 1, 3, and 6 years after their index procedure. CONCLUSIONS: Using the surgical hip dislocation approach as a tool to dynamically inspect the hip for causes of FAI, we were able to perform a variety of procedures to treat the complex deformities of healed LCPD. In the short term, we found improvement in WOMAC scores with a low complication rate. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Clin Orthop Relat Res. 2011 Nov 19;
Terjesen T, Wiig O, Svenningsen S

BACKGROUND: In the Norwegian prospective study on Legg-Calvé-Perthes disease (LCPD), we found varus femoral osteotomy gave better femoral head sphericity at a mean of 5 years postoperative than physiotherapy in children older than 6.0 years at diagnosis with femoral head necrosis of more than 50%. That study did not include separate analyses for hips with 100% necrosis and those with a percentage of necrosis between 50% and 100%. QUESTIONS/PURPOSES: We asked whether (1) femoral osteotomy improves femoral head sphericity at followup in all patients with more than 50% femoral head necrosis or in selected groups only and (2) there is a critical age between 6.0 and 10.0 years over which femoral osteotomy does not improve the prognosis. METHODS: We treated 70 patients with unilateral LCPD, age at diagnosis of more than 6.0 years, and femoral head necrosis of more than 50% with varus femoral osteotomy between 1996 and 2000. We classified necrosis using the Catterall classification. We established a control group of 51 similar children who received physiotherapy. At the 5-year followup visit, the hips were graded according to femoral head shape: spherical, ovoid, or flat. RESULTS: At 5-year followup, there was no difference between the treatment groups in radiographic outcome in Catterall Group 3 hips. In Catterall Group 4 hips, femoral head sphericity was better in the osteotomy group, with flat femoral heads in 14% compared to 75% after physiotherapy. The same trend toward better head sphericity occurred when the lateral pillar classification was used. CONCLUSIONS: In children aged 6.0 to 10.0 years, in whom the whole femoral head is affected, femoral head sphericity 5 years after femoral osteotomy was better than that after physiotherapy. LEVEL OF EVIDENCE: Level II, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.