Coxa Valga Research Articles

Hip Pathology in Majewski Osteodysplastic Primordial Dwarfism Type II

Majewski osteodysplastic primordial dwarfism type II (MOPDII) is characterized by severe prenatal and postnatal growth failure with microcephaly, characteristic skeletal dysplasia, an increased risk for cerebrovascular disease, and insulin resistance. MOPDII is caused by mutations in the pericentrin (PCNT) gene and is inherited in an autosomal-recessive manner. This study aimed to determine the incidence of hip pathology in patients with molecularly confirmed MOPDII and to describe the functional outcomes of surgical treatment. Thirty-three enrolled patients had a clinical diagnosis of MOPDII. Biallelic PCNT mutations or absent pericentrin protein was confirmed in 25 of these patients. Twelve patients (7 female) had appropriate clinical and radiographic records at this institution and were included in this study. The data collected included age at presentation, age at surgery, sex, body weight and height, weight-bearing status at diagnosis, and the clinical examination. Four patients (31%) had coxa vara: 3 unilateral and 1 bilateral. Three unilateral patients had in situ pinning at a mean age 4 years. The patient with bilateral coxa vara had valgus osteotomy at the age of 5 years. Two children had bilateral hip dysplasia and subluxation with no surgery. One patient had bilateral developmental hip dislocations. The patient was treated by open reduction-spica cast and 2 years after surgery, coxa valga was noted. Another patient was diagnosed at an age of 12 years with bilateral avascular necrosis of the hips. Four patients did not have hip pathology. Hip pathology is common among children with MOPDII; coxa vara is the most frequent diagnosis. Routine clinical and radiographic hip evaluation is important. The capital femoral epiphysis appears to slip down along the shaft, giving the appearance of a proximal femoral epiphysiolysis. A hip diagnosed with slipped capital femoral epiphysis in early life may progress to severe coxa vara. Level IV.

Twenty-Year Experience with Rigid Intramedullary Nailing of Femoral Shaft Fractures in Skeletally Immature Patients.

Debate exists over the safety of rigid intramedullary nailing of femoral shaft fractures in skeletally immature patients. The goal of this study was to describe functional outcomes and complication rates of rigid intramedullary nailing in pediatric patients. A retrospective review was performed of femoral shaft fractures in skeletally immature patients treated with trochanteric rigid intramedullary nailing from 1987 to 2009. Radiographs made at initial injury, immediately postoperatively, and at the latest follow-up were reviewed. Patients were administered the Nonarthritic Hip Score and a survey. The study population of 241 patients with 246 fractures was primarily male (75%) with a mean age of 12.9 years (range, eight to seventeen years). The majority of fractures were closed (92%) and associated injuries were common (45%). The mean operative time was 119 minutes, and the mean estimated blood loss was 202 mL. The mean clinical follow-up time was 16.2 months (range, three to seventy-nine months), and there were ninety-three patients with a minimum two-year clinical and radiographic follow-up. An increase of articulotrochanteric distance of >5 mm was noted in 15.1% (fourteen of ninety-three patients) at a minimum two-year follow-up; however, clinically relevant growth disturbance was only observed in two patients (2.2%) with the development of asymptomatic coxa valga. There was no femoral head osteonecrosis. Among the 246 fractures, twenty-four complications (9.8%) occurred. At the time of the latest follow-up, 1.7% (four of 241 patients) reported pain. The average Nonarthritic Hip Score was 92.4 points (range, 51 to 100 points), and 100% of patients reported satisfaction with their treatment. Rigid intramedullary nailing is an effective technique for treatment of femoral shaft fractures in pediatric patients with an acceptable rate of complications. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Radiological results of modified Dega osteotomy in Tönnis grade 3 and 4 developmental dysplasia of the hip.

Dega acetabuloplasty at the time of open reduction is effective in improving the acetabular coverage of the femoral head, hence improving the stability of reduction and preventing possible surgery in the future for residual acetabular dysplasia in older children with Tönnis grade 3 and 4 developmental dysplasia of the hip (DDH). The aim of this study was to assess the radiological results of open reduction combined with Dega osteotomy in DDH. Twenty-two children's 26 hips were operated on at a mean age of 38±20.4 SD months and followed up for an average of 42 (range 24-108) months. Thirteen hips (50%) were operated on with concomitant open reduction and capsulorrhaphy, and 13 hips (50%) were treated with concomitant open reduction, capsulorrhaphy and femoral shortening osteotomy. Radiological examination included acetabular index (AI) and centre edge angle measurements. The mean preoperative AI was 39.4±6.9° SD, which improved to 18.3±4.5° SD postoperatively, and AI was measured as 15±3.5° SD at the latest follow-up. There was a significant difference in the mean AI values between the last follow-up and the preoperative measurements (P<0.05). The mean centre edge angle was 31±5.6° SD postoperatively, and it was 31±6.2° SD at follow-up. There was no significant difference between the two values. Two hips were noted to have lateralization of the femoral head due to coxa valga anteverta. One of them was operated with a femoral varus osteotomy. The Dega osteotomy combined with anterior open reduction and femoral osteotomies is a safe and effective acetabular osteotomy for surgical treatment of severe DDH such as Tönnis grade 3 and 4 dislocations.

Unexpected angular or rotational deformity after corrective osteotomy.

BackgroundCodman’s paradox reveals a misunderstanding of geometry in orthopedic practice. Physicians often encounter situations that cannot be understood intuitively during orthopedic interventions such as corrective osteotomy. Occasionally, unexpected angular or rotational deformity occurs during surgery.This study aimed to draw the attention of orthopedic surgeons toward the concepts of orientation and rotation and demonstrate the potential for unexpected deformity after orthopedic interventions. This study focused on three situations: shoulder arthrodesis, femoral varization derotational osteotomy, and femoral derotation osteotomy.MethodsFirst, a shoulder model was generated to calculate unexpected rotational deformity to demonstrate Codman’s paradox. Second, femoral varization derotational osteotomy was simulated using a cylinder model. Third, a reconstructed femoral model was used to calculate unexpected angular or rotational deformity during femoral derotation osteotomy.ResultsUnexpected external rotation was found after forward elevation and abduction of the shoulder joint. In the varization and derotation model, closed-wedge osteotomy and additional derotation resulted in an unexpected extension and valgus deformity, namely, under-correction of coxa valga. After femoral derotational osteotomy, varization and extension of the distal fragment occurred, although the extension was negligible.ConclusionsSurgeons should be aware of unexpected angular deformity after surgical procedure involving bony areas. The degree of deformity differs depending on the context of the surgical procedure. However, this study reveals that notable deformities can be expected during orthopedic procedures such as femoral varization derotational osteotomy.

Surface arthroplasty in a cerebral palsied patient with hip dysplasia and dislocation

Hip dysplasia is considered to be an etiological factor in the progress of developmental osteoarthrosis of the hip. In patients with cerebral palsy, hip dislocation plus other anatomical alterations such as acetabular dysplasia, coxa valga, excessive femoral anteversion and muscle imbalance can be factors leading to coxarthrosis and pain. Total hip arthroplasty is a valuable method of treatment in some of these patients. However, sometimes young age, bone anatomy and shape, and the possible lack of stability of conventional designs in the context of big surgeries with multiple muscle releases and possible osteotomies make this arthroplasty a very difficult indication to reproduce as a surgeon. Hip resurfacing is a good option because it preserves as much bone stock as possible, doesn’t need corrective osteotomies and gives the prosthesis improved stability. The main concern about this type of prosthesis is the suspected lower survival rate of the femoral component, compared with regular total hip arthroplasties. We present a cerebral palsied patient with hip dysplasia who underwent resurfacing surgery. At a follow up one year after surgery, the patient was pain free, had recovered his motion and functionality, and was able to walk.

Agenesis of the Corpus Callosum and Skeletal Deformities in Two Unrelated Patients: Analysis via MRI and Radiography

Purpose. Mental retardation, mild to severe epilepsy and cerebral palsy often of hemiplegic type are common accompaniments in patients with agenesis/hypoplasia of the corpus callosum. Skeletal deformities of bilateral radiohumeral synostosis, brachydactyly, bilateral elbow dislocation, talipes equinovarus, and juxtacalcaneal accessory bones have been encountered in two unrelated children with agenesis of the corpus callosum. Methods. We report on two unrelated children who presented with the full clinical criteria of agenesis of the corpus callosum. Strikingly, both presented with variable upper and lower limb deformities. The clinical features, radiographic and MRI findings in our current patients, have been compared with previously reported cases identified through a PubMed literature review. Results. Bilateral radiohumeral synostosis associated with pyruvate dehydrogenase deficiency has been encountered in one patient. The other patient manifested bilateral elbow dislocation, coxa valga, talipes equinovarus, and bilateral juxtacalcaneal accessory bones. Conclusion. The constellation of malformation complexes in our current patients have the hitherto not been reported and expanding the spectrum of skeletal deformities in connection with agenesis of the corpus callosum.

Clinical and Radiologic Risk Factors of Acetabular Chondral Damage in Femoroacetabular Impingement Syndrome

Deformities suggestive of femoroacetabular impingement syndrome (FAI) are common in young adults. Since non-invasive measures like MRI provide only limited accuracy to appropriately predict acetabular cartilage damage, valid parameters indicating patients at risk to develop significant chondral defects and osteoarthritis are urgently warranted. Both reduced internal rotation and increased alpha angle have been previously shown to be associated with an increased risk of acetabular chondral injury. The objective of the present study was to investigate the association between various clinical and radiographic parameters and the severity of acetabular cartilage damage. A total of 320 consecutive hip arthroscopies performed by a single surgeon were retrospectively reviewed. Subjects were included in the study if arthroscopic surgery was performed to correct deformities causing FAI. The following exclusion criteria were defined: previous surgery, intra-articular comorbidities (e.g. synovial chondromatosis), other prearthritic deformities (e.g. significant hip dysplasia), systemic inflammatory and musculoskeletal disease, post-traumatic cartilage damage, and insufficient joint distraction to assess the central compartment. Clinical data as well as X-ray and MRI parameters were recorded. The degree of cartilage damage was classified according to Beck et al. distinguishing (0) normal cartilage; (1) softening, surface roughening, fibrillation; (2) loss of fixation to subchondral bone, carpet phenomenon; (3) delamination, frayed edges, flap; and (4) full-thickness defects. Furthermore, the distance of the damaged cartilage extending from the chondrolabral junction to the central fossa was classified as follows: (0) no cartilage damage, (1) = 0.5 cm, (2) >0.5-1.0 cm, (3) >1.0-1.5 cm, (4) >1.5-2.0 cm, (5) >2.0 cm. 193 hips of 157 patients (50 women, 107 men) with an average age of 34 years (range, 17-67) met the inclusion criteria. Proportional odds logistic regression analysis revealed the following risk factors to be significantly associated with both a higher degree (p<0.05) as well as a larger size (p<0.05) of acetabular chondral damage: male gender, higher age at the time of surgery, reduced (internal) rotation, cam-type deformity, pistol grip deformity, positive horizontal growth plate sign, larger alpha angle, larger ½ radial height/radius ratio, smaller femoral head-neck offset, and larger acetabular depth. Regression analysis failed to demonstrate a significant association between cartilage damage and duration of symptoms, moderate coxa vara or coxa valga, center edge angle, cross-over sign, ischial spine sign, coxa profunda, prominent posterior wall, linear indentation sign, herniation pits, os acetabuli, and epiphyseal torsion angle. Our study provides important information on risk factors predicting more severe cartilage injury in FAI. The results might help to identify those patients at higher risk to develop severe chondral damage and osteoarthritis.

Overgrowth syndrome associated with a gain‐of‐function mutation of the natriuretic peptide receptor 2 (NPR2) gene

The signal pathway of the C-type natriuretic (CNP) and its receptor, natriuretic peptide receptor 2 (NPR2) is involved in the longitudinal growth of long bones. Loss of function mutations at NPR2 cause acromesomelic dysplasia, type Maroteaux, while overproduction of CNP by chromosomal translocation and a gain-of-function mutation at NPR2 have been reported to be responsible for an overgrowth syndrome in three cases and one family, respectively. We identified a four-generation family with an overgrowth syndrome characterized by tall stature, macrodactyly of the great toes, scoliosis, coxa valga and slipped capital femoral epiphysis, similar to those previously reported in association with CNP/NPR2 overactivity. The serum level of amino-terminal proCNP was normal in the proband. A novel missense mutation of NPR2, c.1462G>C (p.Ala488Pro) was found to co-segregate with the phenotype in this family. In vitro transfection assay of the mutant NPR2 revealed overactivity of the mutant receptor at baseline as well as with the ligand. This overgrowth syndrome caused by a gain-of-function mutation at NPR2 should be differentiated from Marfan or related syndromes, and may be categorized along with the overgrowth syndrome caused by overproduction of CNP due to its phenotypical similarity as overgrowth CNP/NPR2 signalopathy.

Radiographic Classification of Coronal Plane Femoral Deformities in Polyostotic Fibrous Dysplasia

Fibrous dysplasia of bone is a skeletal dysplasia with a propensity to affect the femur in its polyostotic form, leading to deformity, fracture, and pain. The proximal femur is most commonly involved with a tendency to distal progression, thereby producing the typical shepherd's crook deformity. However, there are few data on the spectrum and progression of femoral deformities in polyostotic fibrous dysplasia. The purposes of this study were (1) to develop a radiographic classification for polyostotic fibrous dysplasia; (2) to test this classification's intra- and interobserver reliability; and (3) to characterize the radiographic progression of polyostotic fibrous dysplasia in a population of patients with the condition who were treated with a variety of approaches at several centers. We retrospectively reviewed radiographs of 127 femurs from 84 adult patients affected by polyostotic fibrous dysplasia. Fifty-nine femurs had undergone one or more operations. The radiographs were evaluated in the coronal plane for neck-shaft angle and angular deformities along the whole femoral shaft down to the distal epiphysis. Four observers evaluated each film two times at intervals; intra- and interobserver reliability testing was performed using the kappa statistic. Eighty-nine femurs (70%) were available for followup to evaluate for progression at a mean of 10 years (range, 6-20 years). Six reproducible patterns of deformity were identified in both untreated and operated femurs: type 1 (24%), normal neck-shaft angle with altered shape of the proximal femur; type 2 (6%), isolated coxa valga with neck-shaft angle > 140°; type 3 (7%), isolated coxa vara with neck-shaft angle < 120°; type 4 (20%), lateral bowing of the proximal half of the femur associated with normal neck-shaft angle; type 5 (14%), like in type 4 but associated with coxa valga; and type 6 (29%), like in type 4 but associated with coxa vara. Interobserver and intraoberver kappa values were excellent, ranging from 0.83 to 0.87. In 46 of the 89 femurs (52%) for which longitudinal radiographic documentation was available, there was progressive worsening of the original deformity, although the pattern remained the same; types 1 and 2 tended not to progress, whereas types 3 to 6 did. A reproducible radiographic classification of polyostotic fibrous dysplasia-associated femoral deformities is proposed, which can serve as a tool for assessing and treating these deformities. After reviewing the radiographs of 127 femurs, we identified six reproducible patterns of femoral deformities. Level III, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Hip Dysplasia Is More Severe in Charcot-Marie-Tooth Disease Than in Developmental Dysplasia of the Hip

Patients with Charcot-Marie-Tooth disease may develop hip dysplasia. Hip geometry in these patients has not been well described in the literature. We compared the hip morphometry in Charcot-Marie-Tooth hip dysplasia (CMTHD) and developmental dysplasia of the hip (DDH) in terms of extent of (1) acetabular dysplasia and subluxation, (2) acetabular anteversion and osseous support, (3) coxa valga and femoral version, and (4) osteoarthritis. Fourteen patients with CMTHD (19 hips; mean age, 23 years) presenting for periacetabular osteotomy were matched to 45 patients with DDH (45 hips; mean age, 21 years) based on age, sex, and BMI. We assessed acetabular dysplasia and subluxation using lateral center-edge angle (LCEA), anterior center-edge angle (ACEA), and acetabular roof angle of Tönnis (TA) on plain pelvic radiographs and acetabular volume, area of femoral head covered by acetabulum, and percentage of femoral head covered by acetabulum on three-dimensional CT reconstruction models. Acetabular version and bony support, femoral version, and neck-shaft angle were measured on two-dimensional axial CT scans. Hip osteoarthritis was graded radiographically according to Tönnis criteria. Acetabular dysplasia was more severe in CMTHD, as measured by smaller LCEA (p < 0.001), ACEA (p < 0.001), and acetabular volume (p = 0.0178) and larger TA (p = 0.025). Hip subluxation was more pronounced in CMTHD, as demonstrated by lower area of femoral head covered by acetabulum (p = 0.034) and percentage of femoral head covered by acetabulum (p = 0.007). CMTHD was associated with higher acetabular anteversion (p < 0.001), lower anterior (p < 0.001) and posterior (p = 0.072) osseous support, and more severe coxa valga (p < 0.001). More (p = 0.006) arthritic hips were found in CMTHD. The extent of acetabular dysplasia, hip subluxation, acetabular anteversion, coxa valga, and hip osteoarthritis was more severe in CMTHD. These findings are important in choosing the appropriate surgical strategy for patients affected by CMTHD.

Deformities of proximal femur in spastic hip displacement: A reconstructed three-dimensional computed tomography model approach

Background/PurposeSpastic hip displacement is a common musculoskeletal problem in cerebral palsy (CP), leading to further complications in daily life. Deformities of the proximal femur were regarded as a factor in hip displacement, and therefore, femoral osteotomy is often recommended. This study aims to identify the relationship between hip displacement and femoral deformities. MethodsWe retrospectively collected preoperative radiography and three-dimensional computed tomography (3D-CT) images from 19 nonambulatory CP children with unilateral hip displacement (average age: 8.4 years; range: 4.4–13.6). The 3D image of femur was reconstructed for measuring the femur anteversion angle (FAA) and true femoral neck-shaft angle (NSA). The association among migration percentage (MP), acetabular index (AI), FAA, and NSA between nondisplaced and displaced hips was analyzed by paired t test and its correlations were identified. ResultsThe FAA and AI are significantly greater in displaced hips (42.7° vs. 36.3° and 32.8° vs. 22.7°, respectively, p < 0.001). However, the NSA is similar between displaced and nondisplaced hips. The AI and FAA have significantly positive correlations with MP between nondisplaced hips and displaced hips (0.69 and 0.57, respectively). ConclusionUsing reconstructed 3D-CT images we can directly measure and prove these femoral deformities. We found that AI has a positive correlation with MP (0.69), which is consistent with the results of previous studies. The displaced side has greater femur anteversion (42.7° vs. 36.3°), and coxa valga is common in these nonambulatory patients, irrespective of whether or not these patients underwent hip displacement. In addition, the severity of AI and anteversion angle will be affected by the MP.

Case Reports: Anteroinferior Acetabular Rim Damage Due to Femoroacetabular Impingement

The most common location of labral tears and chondral damage in the hip is the anterosuperior region of the acetabulum, which is associated with pain in flexion and rotation. We describe a case series of patients with labral tears, ganglion formation, and chondromalacia isolated to the anteroinferior acetabulum. Clinically, patients had pain in extension and internal rotation. Isolated anteroinferior labral hypertrophy and ganglion were first observed in a patient with coxa valga. We retrospectively reviewed clinical and radiographic records and identified nine hips in seven patients with isolated anteroinferior damage. One patient with bilateral valgus femoral head tilt after slipped capital femoral epiphysis (SCFE) had impingement of the anteromedial metaphysis on the acetabulum from 3 to 6 o'clock. Five of seven had valgus neck-shaft angles and all had acetabular anteversion with damage isolated to the anteroinferior acetabular rim. Series on the diagnostic efficacy of MR arthrogram have noted anteroinferior damage adjacent to superior acetabular rim lesions. However, these do not describe isolated anteroinferior rim damage. In addition, available case series of patients with valgus SCFE do not describe a location of impingement or intraarticular damage. In this small case series of patients with isolated anteroinferior chondrolabral damage, there are two potential causative mechanisms: (1) primary anteroinferior impingement with femoral extension and internal rotation and (2) posterior extraarticular ischiotrochanteric impingement causing secondary anterior instability of the femur. The pathoanatomy appears to be multifactorial, necessitating an individualized treatment approach.

Proximal Femoral Geometry Before and After Varus Rotational Osteotomy in Children With Cerebral Palsy and Neuromuscular Hip Dysplasia

Surgical management of hip dysplasia in children with cerebral palsy (CP) usually includes varus rotational osteotomy (VRO) of the proximal femur. Several techniques of VRO (end-to-end, EE; end-to-side, ES) have been designed to maximize correction and minimize associated deformities. The goals of the current study were to establish the prevalence and contribution of caput valgum to coxa valga deformity in children with CP, compare the geometry of the proximal femur after EE and ES techniques of VRO, and document the response of the proximal femur to subsequent growth after VRO. The records of 75 children with CP (Gross Motor Function Classification System, levels IV and V) with 137 surgically treated hips were retrospectively reviewed. Outcomes were limited to the technical domain (eg, radiographic measurements and surgical complications). Measurements made for each hip (preoperative, operative, and follow-up) included the neck-shaft angle (NSA), head-shaft angle (HSA), and the medialization index. The mean age at the time of surgery was 7 years. The mean follow-up was 5 years and 6 months. Caput valgum was present in all hips, increasing the actual geometric valgus by a mean of 10%. The ES technique was more effective at medializing the femoral shaft; however, this benefit was lost with growth (P = 0.891). The ES technique was more effective at achieving and maintaining correction of the NSA (P = 0.026). Maintenance of correction of the HSA was comparable for both ES and EE surgical techniques (P = 0.099). Subsequent growth of the proximal femur resulted in loss of correction of the NSA (mean 29%) and HSA (mean 21%). Caput valgum is usually present in children with CP who are undergoing surgical hip reconstruction. The ES technique is a reasonable alternative for the correction of neuromuscular hip dysplasia associated with extreme coxa valga and long femoral necks. Recurrence of coronal plane deformity with growth after VRO is common, and further study is required to determine how best to control this phenomena. Level IV-therapeutic.

Intertrochanteric fracture under an arthrodesed hip

Patient:Female, 30Primary Diagnosis:Intertrochanteric fracture under an arthrodesed hipCo-existing Diseases:Developmental dysplasia of the hipMedication:Pain • inability to walkClinical Procedure:Open reduction and internal fixationSpecialty:Orthopedics and traumatologyObjective:Rare disease, Unusual setting of medical careBackground:An intertrochanteric fracture among elderly people is common, but it is rare to see such a fracture under a longstanding hip arthrodesis. Its surgical management represents a real challenge to orthopedic surgeons.Case Report:A 30-year-old female teacher with long-standing hip arthrodesis was involved in a traffic accident. Clinical and radiological examination revealed the presence of a displaced intertrochanteric fracture under an arthrodesed hip and high neck shaft angle.Before embarking on surgery, we have to consider many factors such as patient personality (a young active and ambitious woman) and the mature of the fracture (a displaced fracture, coxa valga, and atrophied muscles). After a deep discussion and evaluation of the available devices, we selected a heavy duty locked plate and cannulated screws to fix the fracture.Conclusions:Because of the rarity of intertrochanteric fracture under an arthrodesis hip, the proper surgical treatment is controversial. Nevertheless, we were fortunate in successfully treating this unusual fracture using a locked plate and cannulated screws, which are implants that can be useful in treatment of such fractures.

Long Term Sequels Of Intramedullary Nailing In Childhood Femoral Shaft Fractures.

Objective. To evaluate the impact on bone growth of intramedullary nailing of femur using Kuntscher technique in childhood. ¦ Methods: 18 patients who had undergone Kuntscher technique intramedullary nailing were analyzed as they have grown to adulthood. Growth of each lower limb was compared using predefined clinical and radiological parameters.Results: Patient ages at the time of evaluation, ranged from 21 to 30 years and the follow up length 12 to 16 years. Clinical examination noted 10 normal patients and 8 patients with anomalies, among them 6 were less than 12 years old at the time of intervention. Six¶ patients had lengthening of the operated limb; 4 patients had atrophy¦¦ of the thigh of the operated limb and¦¦¶ 7 patients had coxa valga of operated limb. All patients with coxa valga had undergone the intervention before the age of 12 years.Conclusion: intramedullary nailing using Kuntschter technique to treat femoral fractures in children ¦of feoo may have some long terms sequels. Therefore it is advisable not to use this technique in children less than 12 years old.

Assessment of changes in the loading of menisci following femur structural deformities

Purpose: To evaluate the changes of maximum equivalent stresses (MES) on menisci following femur structural deformities. Materials and methods: Three- Dimensional (3D) solid models were created on MIMICS® by using DICOM formatted longitudinal computed tomography scans. +10° femur neck valgus osteotomy was simulated for coxa valga and -10° varus osteotomy was simulated coxa vara. ANSYS® WorkbenchTM (Version 12) was used to analyze the stress/load distribution on menisci.Results: In the reference model, the MES on medial meniscus was 17.362 Megapascal (MPa), lateral meniscus was 8.621 MPa. The MES was measured 10.632 MPa on medial meniscus and 9.487 MPa on lateral meniscus in coxa vara model. In coxa valga simulated model the MES on medial meniscus was 6.866 MPa while lateral meniscus was 21.854 MPa.Conclusion: Maxiumum equivalent stresses on menisci were affected according to changes in mechanical axis of lower extremity due to proximal femur geometric variations.

Total Hip and Knee Arthroplasty in Patients With Hereditary Multiple Exostoses

To the authors' knowledge, few reports have been published in the English literature of using total knee arthroplasty and total hip arthroplasty for the treatment of hereditary multiple exostoses. This article describes 2 patients with hereditary multiple exostoses, 1 treated with total hip arthroplasty and 1 treated with total knee arthroplasty. Bony deformities make arthroplasty uniquely challenging in patients undergoing total hip or knee arthroplasty. An expanded metaphysis of the proximal femur, coxa valga deformity, and the presence of hardware from previous reconstructive surgeries can make total hip arthroplasty technically difficult. Substantial bony deformity of the distal femur, valgus deformity of the knee, and sizing issues that necessitate custom implants can make total knee arthroplasty difficult. The most common bony deformities in hereditary multiple exostoses are short stature, limb-length discrepancy, valgus deformity at the knee and ankle, and asymmetry of the pectoral and pelvic girdles. Most reported surgical treatments for patients with hereditary multiple exostoses focus on the pediatric population or the management of malignant transformation of exostoses. Studies that specifically address the conditions associated with knee deformities focus on extra-articular deformity correction rather than arthroplasty.When arthroplasty is necessary in this patient population, an understanding of the commonly occurring deformities can help with preoperative planning and surgical management. All painful lesions must be evaluated for malignant transformation. Bone scans can be useful during workup. All specimens should be sent for pathologic evaluation. Such patients are challenging because of the distorted hip anatomy and valgus knee deformity. The current 2 cases illustrate specific challenges that can be anticipated and underscore key principles for arthroplasty in the management of hereditary multiple exostoses.

Hip pathology in Hutchinson–Gilford progeria syndrome

Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disorder. The estimated incidence is one in 4 million births. Orthopaedic manifestations include abnormality of the hips occurring early in the disease process. Severe coxa valga can be apparent by the age of 2 years. We report two cases of HGPS, one in a 7-year-old girl with avascular necrosis of the left hip and the second in a 13-year-old girl with recurrent traumatic hip dislocations. We demonstrate the pathoanatomical changes in the hip with HGPS using a combination of imaging modalities including radiographic, computed tomographic and MRI scans. These include coxa magna, coxa valga and acetabular dysplasia. We also comment on how these would affect the surgical management of this high-risk group of patients.

Long-Term Results of Intertrochanteric Varus Osteotomy for the Dysplastic Hip

Total hip arthroplasty (THA) is a well established treatment for arthrosis of the hip, however many problems remain which have not yet been resolved, including component loosening and infection. Therefore, surgeons hesitate to perform THA in younger patients showing early signs of the disease. Intertrochanteric varus osteotomy was developed for osteoarthrosis with coxa valga. This procedure has been commonly used in patients with dysplastic hips. However, femoral head coverage is not sufficiently improved by this procedure. In order to overcome the disadvantages of this procedure, since 1972 we performed intertrochanteric varus osteotomy simultaneously combined with acetabuloplasty for the treatment of osteoarthrosis secondary to dysplasia. Between 1969 and 1994, we performed 104 intertrochanteric varus osteotomies for prearthrosis and early stage arthrosis of the hip due to acetabular dysplasia in 84 patients. In this study, we reviewed these patients clinically and radiographically, over 15 years. The intertrochanteric varus osteotomy alone was employed in 38 hips (varus group). Combined intertrochanteric varus osteotomy and acetabuloplasty was employed in 63 hips (combined group). The average Harris hip score at the latest follow-up in the combined group significantly higher than that in the 'varus' group. Postoperative centre-edge angle and age at operation were correlated with the Harris hip score at the most recent follow-up. The results of the present study indicate that this combined intertrochanteric varus osteotomy and acetabuloplasty for dysplastic hip should be considered in young patients when the disease is at an early stage.

Fovea Alta on MR Images: Is It a Marker of Hip Dysplasia in Young Adults?

The objective of our study was to investigate the association between high fovea capitis (fovea alta) and hip dysplasia in young adults. In a retrospective study, blinded observers reviewed 82 pelvic radiographic and hip MRI studies of three groups of patients: those with developmental dysplasia of the hip (DDH) (center-edge angle, ≤20°), those with borderline DDH (center-edge angle, 21°-25°), and control patients (center-edge angle, >25°). The center-edge angle and coxa valga (femoral neck-shaft angle, >135°) were assessed on pelvic radiographs, and fovea alta was assessed on MR images (delta angle, ≤10°). The Mann-Whitney and Fisher exact tests were used to correlate fovea alta with DDH and with coxa valga, respectively. Interobserver agreement for center-edge and delta angles and the diagnostic performance of fovea alta as a marker of DDH were calculated. Thirty-one patients with DDH, 23 with borderline DDH, and 28 without DDH were included. Excellent interobserver agreement was found for center-edge angle (concordance correlation coefficient, 0.94) and for delta angle (concordance correlation coefficient, 0.91). Fovea alta had a significant association with DDH (p<0.001) but no association with coxa valga (p>0.57). A significant difference (p<0.001) was found between patients with DDH (3.4°) and those without DDH (21.7°) with respect to mean delta angle measurements. Fovea alta had 69.4% sensitivity, 82.1% specificity, 67.2% positive predictive value, 81.0% negative predictive value, and 75.6% overall accuracy as an indicator of DDH. Fovea alta shows promise as a strong MRI marker of DDH.