Investigating pelvic drop gait abnormality in adolescent hip pathology patients.

BACKGROUND: Trendelenburg gait describes contralateral pelvic drop during single leg stance (SLS) with occasional lateral trunk lean compensation over the stance limb. However, quantitative research on 'uncompensated Trendelenburg' gait (pelvic drop independent of lateral trunk lean) remains sparse among populations that commonly utilize this gait pattern, such as adolescent hip pathology patients. RESEARCH QUESTION: How prevalent is uncompensated Trendelenburg among various adolescent hip pathologies and how is it related to hip load, hip abduction strength, and self-reported hip pain? METHODS: Gait, strength, and pain data were collected among 152 pre-operative patients clinically diagnosed with acetabular hip dysplasia, femoroacetabular impingement, Legg-Calvé-Perthes, or slipped capital femoral epiphysis (SCFE). Patients with ≥ 5.4° of dynamic pelvic drop in SLS were divided into a 'pelvic drop' group and screened to exclude those with excessive ipsilateral trunk lean. They were then compared to the 'stable pelvis' patients using a Mann-Whitney test. RESULTS: Dysplasia patients represented the highest proportion of the pelvic drop group (46%). The pelvic drop group showed a significant increase in self-reported hip pain (p = 0.011), maximum hip abductor moment (p = 0.002), and peak coronal power absorption at the affected hip during SLS loading response, (p < 0.001) while showing no difference in abduction strength (p = 0.381). SIGNIFICANCE: Uncompensated Trendelenburg gait may lead to increased loading of the affected hip in adolescent hip pathology patients. Disadvantageous hip biomechanics can create increased abductor muscle demand among these pathological populations, with dysplasia patients showing the highest prevalence. Maximal abduction strength did not correlate with pelvic drop. Future work should aim to identify and quantify causal factors. Increased coronal hip power absorption during weight acceptance warrants clinical attention, as there may be a detrimental, over-reliance on passive hip structures to support load among a population that that is already predisposed to hip osteoarthritis.

PROMIS Paediatric Mobility tool is correlated with accelerometer-measured physical activity in children with hip diseases.

AIMS: The reduction in mobility due to hip diseases in children is likely to affect their physical activity (PA) levels. Physical inactivity negatively influences quality of life and health. Our aim was to objectively measure PA in children with hip disease, and correlate it with the Patient-Reported Outcomes Measurement Information System (PROMIS) Mobility Score. METHODS: A total of 28 children (12 boys and 16 girls) with hip disease aged between 8and 17 years (mean 12 (SD 3)) were studied between December 2018 and July 2019. Children completed the PROMIS Paediatric Item Bank v. 2.0 - Mobility Short Form 8a and wore a hip accelerometer (ActiGraph) for seven consecutive days. Sedentary time (ST), light PA (LPA), moderate to vigorous PA (MVPA), and vigorous PA were calculated from the accelerometers' data. The PROMIS Mobility score was classified as normal, mild, and moderate functions, based on the PROMIS cut scores on the physical function metric. A one-way analysis of covariance (ANCOVA) was used to assess differences among mobility (normal; mild; moderate) and measured PA and relationships between these variables were assessed using bivariate Pearson correlations. RESULTS: Children classified as normally functioning on the PROMIS had less ST (p = 0.002), higher MVPA, (p = 0.002) and VPA (p = 0.004) compared to those classified as mild or moderate function. A moderate correlation was evident between the overall PROMIS score and daily LPA (r = 0.462, n = 28; p = 0.013), moderate-to-vigorous PA (r = 0.689, n = 28; p = 0.013) and vigorous PA (VPA) (r = 0.535, n = 28; p = 0.013). No correlation was evident between the mean daily ST and overall PROMIS score (r = -0.282, n = 28; p = 0.146). CONCLUSION: PROMIS Pediatric Mobility tool correlates well with experimentally measured levels of physical activity in children with hip disease. We provide external validity for the use of this tool as a measure of physical activity in children. Cite this article: Bone Joint J 2021;103-B(2):405-410.

Impingement-free hip range of motion after osteochondroplasty and relative neck lengthening in adults with healed Perthes disease.

OBJECTIVE: Our main objective is to assess the efficiency of the osteochondroplasty with relative neck lengthening in adults with healed Perthes clinically (through assessment of impingement-free hip ROM, functional scores) and radiographically. PATIENTS AND METHODS: This was a prospective case series study included 30 hips of 30 patients who underwent osteochondroplasty and RNL due to symptomatic healed LCPD. This study included 16 males (53.3%) and 14 females (46.7%). The age of patients ranged from 19 to 40 years with mean age 26.4 years at the date of surgery (SD 6.4). RESULTS: Median time of follow-up was 27.7 months after surgery (range 12-60 months). Two patients (6.6%) developed avascular necrosis (AVN) and needing total hip replacement; none of our patients developed nerve injury, detachment of the trochanteric fragment, and wound infection needing treatment. Preoperative Stulberg classes II and III improved more than preoperative Stulberg classes IV and V, although not statistically significant (P = 0.1104, n = 30). The mean HHS and WOMAC score values for each patient were higher in the Stulberg II and III groups compared to the Stulberg IV and V groups CONCLUSION: Head and neck osteochondroplasty performed through the surgical dislocation approach, combined with RFNL, relieved pain and restored function in most of the patients with reasonable complications. LEVEL OF EVIDENCE: IV.

Analysis of Outcomes of Total Cementless Hip Joint Arthroplasty in the Treatment of Advanced Hip Osteoarthritis Following Childhood Perthes' Disease.

BACKGROUND: The aim of this study is to analyse the outcomes of total cementless hip joint arthroplasty in the treatment of advanced hip osteoarthritis following Perthes' disease in childhood. MATERIAL AND METHODS: The study enrolled 56 patients (15 women and 41 men) who underwent a total of 61 hip joint arthroplasties for coxarthrosis following Perthes' disease. The mean age of the patients at surgery was 46.7 years (range 21-67 years). The mean follow-up period was 13.7 years. RESULTS: Pre-operative Merle d'Aubigne-Postel scores (modified by Charnley) of the study group were poor in all patients. Mean post-operative improvement was 6.7 points. The outcomes were classified as excellent in 25 cases, good in 16, satisfactory in 16 and poor in 9 cases. Poor results were always related to loosening of the acetabular cup. Heterotopic ossification was noted in 7 cases. According to the Kaplan-Meier estimator, 10 years' survival probability was 85.24% for the whole implant and 100% for the stem. CONCLUSIONS: 1. Total cementless hip joint arthroplasty is an effective method in the treatment of advanced hip osteoarthritis following Perthes' disease in childhood. 2. With good surgical technique and in the absence of complications, the risk of aseptic loosening is minimal. 3. Due to the patients' young age, there may be more cases of loosening over time, requiring regular long-term follow-up.

Secondary hip dysplasia increases risk for early coxarthritis after Legg-Calve-Perthes disease. A study of 255 hips.

The biomechanical parameters of the hip joint articular surface were analysed in 141 adult hips after Legg-Calve Perthes Disease, and 114 contralateral unaffected hips (controls), by using HIPSTRESS mathematical models. Geometrical parameters, assessed from anteroposterior and axial radiograms, were used as input to models for resultant hip force and contact hip stress. Results confirm previous indications that head enlargement after the Legg-Calve-Perthes Disease compensates the values of hip stress. Furthermore, it was found that an increased risk for coxarthritis development after the disease is secondary to concomitant hip dysplasia, with considerable and statistically significantly lower centre-edge angle and unfavourable distribution of stress.

Hip arthroscopy for Legg-Calvè-Perthes disease in paediatric population.

OBJECTIVE: The aim of this study was to represent the findings and long-term clinical results of the children who underwent hip arthroscopy because of Legg-Calve-Perthes Disease (LCPD). METHODS: This study included the retrospective findings of ten patients (mean age: 12.7 ± 2.75; range 7-16 years) who underwent arthroscopic hip debridement between 2010 and 2016 for LCPD disease. All of the patients underwent arthroscopic excision of the unstable osteochondral fragment following unsuccessful conservative treatment. In the statistical analysis, age, side, follow-up, Stulberg and Waldenström classification, preoperative and postoperative modified Harris Hip Score (mHHS) were evaluated. RESULTS: The mean follow-up period was 55.4 ± 13.05 months (range: 40-72 months). There was no statistically significant association between good postoperative results and age, side, and the stage of the disease (p > 0.05). However, there was a significant difference between preoperative and postoperative mHHS (p = 0.005). CONCLUSION: This study demonstrates an increase in the functional results and life quality of the patients who underwent hip arthroscopy due to LCPD. It is thought that hip arthroscopy, a minimally invasive procedure, may have an important role in the algorithm of LCPD treatment, especially in patients with severe pain and mechanical symptoms. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Varus Derotational Osteotomy.

Legg-Calve-Perthes disease is a multifactorial process that can lead to debilitating femoral head deformity in children. Management can range from conservative (such as nonweightbearing protocols), bracing (such as A frames), to more invasive measures involving surgical interventions. First described by Axer in 1965, the varus derotational osteotomy (VDRO) has been a staple in the surgical management of Perthes disease. The goal of the VDRO is "containment" or prevention of extrusion of the head from the acetabulum. Many variations of the technique have been described over the years since its inception, but the most important factor in outcome is timing the intervention at the appropriate stage of Perthes disease to allow for maximum benefit. Through varusization of the neck shaft angle of the proximal femur, the VDRO has been shown to be a powerful tool in the management of those afflicted. As with any operative procedure, the VDRO can be associated with complications such as premature epiphyseal closure leading to shortened extremity, albeit very rare in occurrence. The VDRO is a mainstay in the treatment algorithm for Legg-Calve-Perthes disease and will continue to remain so in the future.

Evaluation of the hip joint contact force in subjects with Perthes based on OpenSIM.

The head of femoral bone is deformed in the subjects with Leg Calve Perthes disease (LCPD). This may be due to the excessive loads applied on it. There are no studies that report the hip joint contact force in subjects with LCPD. Therefore, the aim of this study was to evaluate the hip joint contact force in subjects with Perthes disease. Ten typically-developing (TD) children and 10 children with LCPD were recruited in this study. The kinematics and kinetics of the subjects were evaluated in 3D motion analysis. The hip joint contact force was approximated using OpenSIM software. Differences were determined with an independent t-test. There was a significant difference between walking speed of TD and Perthes subjects (63.8 (±8.1) and 57.4 (±7.0) m/min, respectively). The first peak of hip joint contact force was 4.8 (±1.7) N/BW in Perthes subjects, compared to 7.6 (±2.5) N/BW in TD subjects (p = 0.004). The peak hip joint contact force in mediolateral and anteroposterior directions was significantly lower in Perthes subjects (p < 0.05). The hip joint excursion was 40.0 (±5.6) and 46.4 (±8.5) degrees in Perthes and normal subjects, respectively (p = 0.03). The hip joint contact forces were lower in the subjects with Perthes disease. Therefore, it can be concluded that the strategies used by LCPD subjects were successful to decrease hip joint contact force.

The outcomes of Perthes' disease of the hip: a study protocol for the development of a core outcome set.

BACKGROUND: Perthes' disease is an idiopathic osteonecrosis of a developmental hip that is most frequent in Northern Europe. Currently, the absence of a common set of standardised outcomes makes comparisons between studies of different interventions challenging. This study aims to summarise the outcomes used in clinical research of interventions for Perthes' disease and define a set of core outcomes (COS) to ensure that the variables of primary importance are measured and reported in future research studies investigating Perthes' disease. METHODS: A systematic review of the current literature will be used to identify a list of outcomes reported in previous studies. Additional important outcomes will be sought by interviewing a group of children with Perthes' disease, adults who were treated with the disease in infancy and parents of children with the disease. This list will then be evaluated by experts in Perthes' disease using a Delphi survey divided into two rounds to ascertain the importance of each outcome. The final outcomes list obtained from the Delphi survey will be then discussed during a consensus meeting of representative key stakeholders in order to define the COS to be reported in future clinical trials related to Perthes' disease. DISCUSSION: The absence of high-quality research and clear guidelines concerning the management of Perthes' disease is, at least in part, due to the difficulties in the comparing the results from previous studies. The development of a COS seeks to standardise outcomes collected in future research studies to enable comparisons between studies to be made and to facilitate meta-analyses of results. TRIAL REGISTRATION: Core Outcome Measures in Effectiveness Trials Initiative (COMET), 1003 . Registered on 20 July 2017. Prospero International Prospective Register of Systematic Reviews, CRD 42017069742 . Registered on 10 July 2017.

The potential role of variations in juvenile hip geometry on the development of Legg-Calvé-Perthes disease: a biomechanical investigation.

Legg-Calvé-Perthes disease (LCP) is one of the most poorly understood diseases in paediatric orthopaedics. One common trait of LCP is the marked morphological difference between healthy and pathological hips, early deviations of which (i.e. prior to disease onset) have been suggested to lead to the overload and collapse of the epiphysis. Here, the impact of common variations in geometry is investigated with a finite element model of a juvenile femur under single leg standing and landing. Here, the impact of typical variations in geometry is investigated with a finite element model of a juvenile femur under single leg standing and landing. The variations appear to have only a limited effect on the stress distribution in the femoral epiphysis even during high impact activities. This suggests that, for this individual at least, they would be unlikely to cause epiphyseal overload and collapse, even in the presence of a skeletally immature epiphysis.

An Analysis of Relative Gait Impairment in Commonly Diagnosed Pediatric Conditions.

BACKGROUND: Gait indices were developed to represent the magnitude of impairment extracted from a gait analysis with a single value. The Gillette Gait Index (GGI), and the Gait Deviation Index (GDI) are 2 widely used indices that represent gait impairment differently based on their statistical properties. Our purpose was to (1) report on the results of gait analysis for a broad spectrum of pediatric conditions using the GGI and GDI, and (2) identify the parameters that dominate impairment. METHODS: A total of 1439 children with 13 different diagnoses with a complete, baseline gait analysis were identified. The GGI and its 16 parameters were calculated in all cases, and the GDI was calculated from a smaller subset. T tests, and z-scores were used to compare each of these values to typically developing children for each diagnosis. A separate linear regression controlling for age, sex, and use of an orthosis, or assistive device was performed for the GGI. RESULTS: In our series, there were 71 typically developing children with a GGI of 31. We qualify relative gait impairment as severe, mild, or moderate as based on the GGI, and propose that values <100 represent mild, 100 to 200 represent moderate, and >200 represents severe impairment. On the basis of strong correlation between the GGI and GDI, we suggest that GDI values >80 represent mild, and values <70 represent severe impairment. T tests and z-scores demonstrated that both the number and magnitude of abnormal parameters increase the GGI. These tests also identified the most clinically relevant parameters contributing to functional impairment for each diagnosis. Multivariate linear regression showed that all diagnoses except flatfoot and scoliosis demonstrated statistically significant differences in GGI scores. CONCLUSIONS: This is the first study to apply these gait indices to a large population of diverse pediatric conditions. We propose GGI and GDI values to qualify gait impairment among these conditions as severe, moderate, or mild. Furthermore, impairment in gait reflects both the number and magnitude of abnormal parameters within each condition. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

Long-term Results of Modified Salter Innominate Osteotomy for Legg-Calvé-Perthes Disease.

BACKGROUND: In a previous study, we reported clinical and radiographic results of our modified Salter innominate osteotomy technique in 16 hips affected by Legg-Calvé-Perthes disease (LCPD) with an average follow-up of 31.8 months. In this study, we present the long-term results of the osteotomy in LCPD patients followed until physeal closure. METHODS: Thirty hips of 29 patients were followed until skeletal maturation after modified Salter innominate osteotomy. The mean follow-up duration was 12.9 years (range, 9.1 to 16.0 years). Eleven hips (36.7%) were classified as Catterall group III and 19 (63.3%) as Catterall group VI. Stable interposition of a bone block was achieved using one biodegradable screw in nine hips and without any fixation device in 21 hips by simply changing the direction of osteotomy. The Harris Hip Score (HHS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and hip function were evaluated at the last follow-up. Radiological outcomes were evaluated using Wiberg's center-edge angle, the Mose method, and Stulberg classification, and osteoarthritic changes were evaluated using the Tonnis classification. RESULTS: Mean HHS and WOMAC score were 80.2 points and 54 points, respectively, preoperatively and these were improved to 96.2 points and 28 points, respectively, at the last follow-up. Clinical results, according to Robinson's criteria, were good in 18, fair in seven, and poor in five hips. Radiological results assessed using the Mose method were good in 18, fair in six, and poor in six hips, and according to the Stulberg classification, nine hips were class I, nine were class II, eight were class III, and four were class IV. The mean center-edge angle improved from 19.7° preoperatively to 29.6° at the final follow-up. According the Tonnis classification, three hips were grade 2, five were grade 1, and 22 were grade 0. Of the three grade 2 hips, two underwent Chiari osteotomy 12.1 and 8.8 years postoperatively, and the other underwent total hip arthroplasty 12.9 years postoperatively. CONCLUSIONS: The modified Salter innominate osteotomy produced relatively satisfactory long-term clinical and radiological results.

A method to investigate the biomechanical alterations in Perthes' disease by hip joint contact modeling.

Perthes' disease is a destructive hip joint disorder characterized by malformation of the femoral head in young children. While the morphological changes have been widely studied, the biomechanical effects of these changes still need to be further elucidated. The objective of this study was to develop a method to investigate the biomechanical alterations in Perthes' disease by finite element (FE) contact modeling using MRI. The MRI data of a unilateral Perthes' case was obtained to develop the three-dimensional FE model of the hip joint. The stress and contact pressure patterns in the unaffected hip were well distributed. Elevated concentrations of stress and contact pressure were found in the Perthes' hip. The highest femoral cartilage von Mises stress 3.9 MPa and contact pressure 5.3 MPa were found in the Perthes' hip, whereas 2.4 MPa and 4.9 MPa in the healthy hip, respectively. The healthy bone in the femoral head of the Perthes' hip carries additional loads as indicated by the increase of stress levels around the necrotic-healthy bone interface. Identifying the biomechanical changes, such as the location of stress and contact pressure concentrations, is a prerequisite for the preoperative planning to obtain stress relief for the highly stressed areas in the malformed hip. This single-patient study demonstrated that the biomechanical alterations in Perthes' disease can be evaluated individually by patient-specific finite element contact modeling using MRI. A multi-patient study is required to test the strength of the proposed method as a pre-surgery planning tool.

Two cases of Legg-Perthes and intellectual disability in Tricho-Rhino-Phalangeal syndrome type 1 associated with novel TRPS1 mutations.

Tricho-Rhino-Phalangeal syndrome is a rare autosomal dominant genetic disorder caused by mutations in the TRPS1 gene. This malformation syndrome is characterized by distinctive craniofacial features including sparse scalp hair, bulbous tip of the nose, long flat philtrum, thin upper vermilion border, and protruding ears. Skeletal abnormalities include cone-shaped epiphyses at the phalanges, hip malformations, and short stature. In this report, we describe two patients with the physical manifestations and genotype of TRPS type I but with learning/intellectual disability not typically described as part of the syndrome. The first patient has a novel heterozygous two-base-pair deletion of nucleotides at 3198-3199 (c.3198-3199delAT) in the TRPS1 gene causing a translational frameshift and subsequent alternate stop codon. The second patient has a 3.08 million base-pair interstitial deletion at 8q23.3 (113,735,487-116,818,578), which includes the TRPS1 gene and CSMD3. Our patients have characteristic craniofacial features, Legg-Perthes syndrome, various skeletal abnormalities including cone shaped epiphyses, anxiety (first patient), and intellectual disability, presenting unusual phenotypes that add to the clinical spectrum of the disease.

Evaluation of the magnitude of hip joint deformation in subjects with avascular necrosis of the hip joint during walking with and without Scottish Rite orthosis.

The femoral head in subjects with leg calve perthes disease (LCPD) is generally considerably deformed. It is debatable whether this deformation is due to an increase in applied loads, a decrease in bone mineral density or a change in containment of articular surfaces. The aim of this study was to determine the influence of these factors on deformation of the femoral head. Two subjects with LCPD participated in this study. Subject motion and the forces applied on the affected leg were recorded using a motion analysis system (QualsisTM) and a Kistler force plate. OpenSim software was used to determine joint contact force of the hip joint whilst walking with and without a Scottish Rite orthosis. 3D Models of hip joints of both subjects were produced by Mimics software. The deformation of femoral bone was determined by Abaqus. Mean values of the force applied on the leg increased while walking with the orthosis. There was no difference between bone mineral density (BMD) of the femoral bone of normal and LCPD sides (p-value>0.05) and no difference between hip joint contact force of normal and LCPD sides. Hip joint containment appeared to decrease follow the use of the orthosis. It can be concluded that the deformation of femoral head in LCPD may not be due to change in BMD or applied load. Although the Scottish Rite orthosis is used mostly to increase hip joint containment, it appears to reduce hip joint contact area. It is recommended that a similar study is conducted using a higher number of subjects.

Assessment of Femoral Head Revascularization in Legg-Calvé-Perthes Disease Using Serial Perfusion MRI.

BACKGROUND: Legg-Calvé-Perthes disease is a juvenile form of osteonecrosis of the femoral head. The purpose of this study was to use serial perfusion magnetic resonance imaging (MRI) to determine the pattern and rate of revascularization of the femoral heads of patients with the active stage of Legg-Calvé-Perthes disease. METHODS: We performed a prospective study of 29 patients (30 hips) with a mean age (and standard deviation) of 8.4 ± 1.9 years who were diagnosed with Waldenström Stage-1 or 2 Legg-Calvé-Perthes disease. All patients had ≥2 perfusion MRIs, and 21 patients (22 hips) had ≥3. Perfusion percentages of the femoral epiphyses were measured by 2 independent observers. Statistical analyses included calculation of the intraclass correlation coefficient, the paired t test, the Mann-Whitney U test, and the Kruskal-Wallis test. RESULTS: Initial perfusion MRIs showed the percent perfusion in the affected femoral heads to range from 5% to 70%. The average percent perfusion (and standard deviation) was 35% ± 16% on the first MRI, which increased to 77% ± 14% on the follow-up MRI acquired at an average of 10.5 ± 2.9 months later (p < 0.01). Serial assessment showed a general pattern of revascularization starting from the periphery of the posterior, lateral, and medial aspects of the femoral epiphysis and converging toward the anterocentral region. The average rate of revascularization was 4.9% ± 2.3% per month with a wide range among the patients (0.6% to 10.4% per month). CONCLUSIONS: Revascularization of the necrotic femoral head increased over time in a horseshoe pattern, starting from the posterior, lateral, and medial aspects of the femoral epiphysis. The rate of revascularization was highly variable among patients. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Development of gait performance and dynamic hip and knee joint loading after containment improving surgery in patients with Legg-Calvé-Perthes disease.

Current surgery outcome evaluations in patients with Legg-Calvé-Perthes disease (LCPD) are usually based on static radiological changes. The aim of the present study was to assess the development of characteristic gait parameters and passive hip range of motion (ROM) measurements during the postoperative period up to healed stage of the femoral head represented by Stulberg classification. Twelve children (10 male, 2 female) with unilateral diagnosis of LCPD and 19 healthy control subjects at the same age participated in this prospective longitudinal study. Instrumented gait analysis was performed preoperatively, 13.4 (±1.7), and 28.0 (±4.4) months postoperatively. At final follow-up, the mean leg length of the involved side was reduced by 1.10 (±0.53)cm compared to the non-involved side. In addition, a significant reduction in maximum knee flexion (-26%, p=0.037) and knee flexion/extension ROM (-26%, p=0.017) in stance was still present in the patient group compared to controls indicating a "stiff knee gait pattern". In contrast, the sagittal plane hip parameters, the ipsilateral trunk lean toward the involved stance limb, and the knee and hip joint loading during gait normalized during the postoperative period. The results of the present study should motivate further exploration if patients with LCPD stiffen their knees to compensate for leg length discrepancy. Besides the standard radiological evaluation of the surgery outcome, instrumented gait analysis is a valuable method of recording functional deficits and early recognition of the need for physiotherapeutic treatment or insole supply in patients with LCPD.

Clinical and radiographic outcomes after femoral varus derotation osteotomy for Legg-Calvé-Perthes disease at 25 years follow-up: what are the determinants of outcome in the long term?

OBJECTIVE: The main purposes of the present study were to analyse the long-term clinical and radiographic results of femoral varus derotation osteotomy performed in a group of patients with the diagnosis of Legg-Calvé-Perthes (LCP) disease and to compare the effects of age, lateral pillar classification, radiographic stage according to Waldenström's classification, and the amount of varisation obtained on long-term results. DESIGN: The study group consisted of 21 hips. The mean postoperative follow-up time was 25.1 years. The effect of age at the time of surgery, preoperative lateral pillar classification, Waldenström's classification, and the amount of varisation on Merle d'Aubigne score, Stulberg class, and presence of degenerative arthritis of the hip joint were assessed at the final follow-up. RESULTS: Better clinical and radiographic outcomes were detected in patients operated younger than 10 years. The hips with lateral pillar group C involvement preoperatively were found to be significantly associated with worse clinical scores, worse radiographic outcome, and higher rate of degenerative arthritis. The overall rate of the hips with good radiologic outcome was 52.4%. 7 hips had degenerative arthritis at the final follow-up. CONCLUSIONS: Femoral varus derotation osteotomy revealed a congruent joint in half of the operated hips and arthritis-free hip joint in 2/3 at 25 years follow-up. Age at the time of surgery and preoperative lateral pillar classification were the main determinants of the radiographic outcome whereas the factors significantly correlated with progression to degenerative arthritis were determined preoperative lateral pillar classification and Stulberg group at maturity.

Head reduction osteotomy with additional containment surgery improves sphericity and containment and reduces pain in Legg-Calvé-Perthes disease.

BACKGROUND: Severe femoral head deformities in the frontal plane such as hips with Legg-Calvé-Perthes disease (LCPD) are not contained by the acetabulum and result in hinged abduction and impingement. These rare deformities cannot be addressed by resection, which would endanger head vascularity. Femoral head reduction osteotomy allows for reshaping of the femoral head with the goal of improving head sphericity, containment, and hip function. QUESTIONS/PURPOSES: Among hips with severe asphericity of the femoral head, does femoral head reduction osteotomy result in (1) improved head sphericity and containment; (2) pain relief and improved hip function; and (3) subsequent reoperations or complications? METHODS: Over a 10-year period, we performed femoral head reduction osteotomies in 11 patients (11 hips) with severe head asphericities resulting from LCPD (10 hips) or disturbance of epiphyseal perfusion after conservative treatment of developmental dysplasia (one hip). Five of 11 hips had concomitant acetabular containment surgery including two triple osteotomies, two periacetabular osteotomies (PAOs), and one Colonna procedure. Patients were reviewed at a mean of 5 years (range, 1-10 years), and none was lost to followup. Mean patient age at the time of head reduction osteotomy was 13 years (range, 7-23 years). We obtained the sphericity index (defined as the ratio of the minor to the major axis of the ellipse drawn to best fit the femoral head articular surface on conventional anteroposterior pelvic radiographs) to assess head sphericity. Containment was assessed evaluating the proportion of patients with an intact Shenton's line, the extrusion index, and the lateral center-edge (LCE) angle. Merle d'Aubigné-Postel score and range of motion (flexion, internal/external rotation in 90° of flexion) were assessed to measure pain and function. Complications and reoperations were identified by chart review. RESULTS: At latest followup, femoral head sphericity (72%; range, 64%-81% preoperatively versus 85%; range, 73%-96% postoperatively; p = 0.004), extrusion index (47%; range, 25%-60% versus 20%; range, 3%-58%; p = 0.006), and LCE angle (1°; range, -10° to 16° versus 26°; range, 4°-40°; p = 0.0064) were improved compared with preoperatively. With the limited number of hips available, the proportion of an intact Shenton's line (64% versus 100%; p = 0.087) and the overall Merle d'Aubigné-Postel score (14.5; range, 12-16 versus 15.7; range, 12-18; p = 0.072) remained unchanged at latest followup. The Merle d'Aubigné-Postel pain subscore improved (3.5; range, 1-5 versus 5.0; range, 3-6; p = 0.026). Range of motion was not observed to have improved with the numbers available (p ranging from 0.513 to 0.778). In addition to hardware removal in two hips, subsequent surgery was performed in five of 11 hips to improve containment after a mean interval of 2.3 years (range, 0.2-7.5 years). Of those, two hips had triple osteotomy, one hip a combined triple and valgus intertrochanteric osteotomy, one hip an intertrochanteric varus osteotomy, and one hip a PAO with a separate valgus intertrochanteric osteotomy. No avascular necrosis of the femoral head occurred. CONCLUSIONS: Femoral head reduction osteotomy can improve femoral head sphericity. Improved head containment in these hips with an often dysplastic acetabulum requires additional acetabular containment surgery, ideally performed concomitantly. This can result in reduced pain and avascular necrosis seems to be rare. With the number of patients available, function did not improve. Therefore, future studies should use more precise instruments to evaluate clinical outcome and include longer followup to confirm joint preservation.