A Contemporary Definition of Hip Dysplasia and Structural Instability: Toward a Comprehensive Classification for Acetabular Dysplasia.

Hip dysplasia has long been known to be a risk factor for pain and degenerative changes in the hip joint. The diagnosis of dysplasia has historically been based on assessments of acetabular anatomy on the anteroposterior pelvic radiograph, most commonly the lateral center-edge angle. Recent advances in imaging of the dysplastic hip with computerized tomography scans have demonstrated that hip dysplasia is in fact a 3-dimensional (D) deformity of the acetabulum and that multiple patterns of hip instability exist that may not be completely assessed on 2D imaging. A more thorough understanding of acetabular anatomy permits an evolution away from vague terms such as "borderline dysplasia." A 3D assessment of the acetabulum and the resultant patterns of instability may be more appropriate since this would allow more accurate treatment to correct the structural instability with acetabular reorientation. With this information, we propose a diagnostic framework that groups symptomatic dysplastic hips into one of 3 categories based on the primary direction of instability: (1) anterior, (2) posterior, and (3) global. This framework may aid the clinician in developing a differential diagnosis for the assessment of hip pain and suspected instability, and for planning an appropriate surgical management.

The ratio of femoral head diameter to pelvic height in the normal hips of a Chinese population.

OBJECTIVE: The aim of this study was to determine whether the ratio between the femoral head diameter and pelvic height in a Chinese population is the same as that found in Westerners. MATERIALS AND METHODS: Standard pelvic radiography was performed on a group of 187 Chinese adult subjects consisting of 81 males and 106 females with a mean age of 40 years (21-68 years). Femoral head diameter (vertical distance from the femoral head-neck junction to the highest point of the femoral head) and pelvic height (vertical distance from the highest point of the iliac crest to the edge of the ischial tuberosities) were measured. RESULTS: There were significant differences between males and females (p < 0.001), and between persons of high height versus low height (p = 0.011) and medium height (p = 0.039). There were no significant differences between persons of different age (p = 0.244), body mass index (p = 0.091), or between persons of low- and medium-height groups (p = 0.69). The overall mean ratio between the femoral head diameter and pelvic height was 0.215 (0.173-0.249) with a 95 % CI = 0.214-0.217. The mean ratios in males and females were 0.221 (0.194-0.249) and 0.211 (0.173-0.238), respectively. CONCLUSION: The mean ratio in Chinese population was similar to the reported ratio in a western population (about 1:5). We suggest that Chinese surgeons may be able to use the Crowe classification to classify patients with hip dysplasia.

Verification of the Robin and Graham classification system of hip disease in cerebral palsy using three-dimensional computed tomography.

AIM: We evaluated the validity of the Robin and Graham classification system of hip disease in cerebral palsy (CP) using three-dimensional computed tomography in young people with CP. METHOD: A total of 91 hips in 91 consecutive children with bilateral spastic CP (57 males, 34 females; nine classified at Gross Motor Function Classification System level II, 42 at level III, 32 at level IV, and eight at level V; mean age 5 y 2 mo, SD 11 mo; range 2-6 y) were investigated retrospectively using anteroposterior plain radiographs and three-dimensional computed tomography (3D-CT) of the hip. The migration percentage was calculated on plain radiographs and all participants were classified into four groups according to migration percentage: grade II, migration percentage ≥ 10% but ≤ 15%, (four hips), grade III, migration percentage >15% but ≤ 30%, (20 hips); grade IV, migration percentage >30% but <100%, (63 hips); and grade V, migration percentage ≥ 100%, (four hips). The lateral opening angle and the sagittal inclination angle of the acetabulum, the neck-shaft angle, and the femoral anteversion of the femur were measured on 3D-CT. RESULTS: The three-dimensional quantitative evaluation indicated that there were significant differences in the lateral opening angle and the neck-shaft angle between the four groups (Kruskal-Wallis test, p ≤ 0.001). INTERPRETATION: This three-dimensional evaluation supports the validation of the Robin and Graham classification system for hip disease in 2- to 7-year-olds with CP.

Cemented total hip arthroplasty with transverse subtrochanteric shortening osteotomy for Crowe group IV dislocated hip.

A consecutive series of 19 cemented total hip arthroplasties with transverse subtrochanteric shortening osteotomy was performed for Crowe group IV hip, with a mean follow-up of 38 (6-96) months. The osteotomy sites were covered with onlay grafts of the excised fragments. The conditions of the osteotomy sites were classified into 3 types according to the presence of a remaining gap and cement interposition within it. Three cases had a noticeable gap, and 2 of them showed cement interposition. All osteotomy sites became united involving the onlay grafts, with an average time to union of 4.9 (3-8) months. Our findings suggest that cemented total hip arthroplasty with subtrochanteric transverse osteotomy provides satisfactory short-term results without major complications for Crowe group IV hip.

Traumatic hip dislocation at a regional trauma centre in Nigeria.

BACKGROUND: Traumatic dislocation or fracture-dislocation of the hip is an orthopaedic emergency that is steadily increasing in incidence due to high-speed motor vehicular accidents. These injuries need to be recognized early and promptly treated to prevent morbidity and long-term complications. Some of the fundamental issues in the management of traumatic dislocations of the hip are the critical interval between injury and reduction, the type of reduction most suitable for various types of injury and the duration of immobilization that give the best results. This study was carried out at the National Orthopaedic Hospital Enugu, a regional trauma and orthopaedic centre in South-East Nigeria. The purpose of the study is to describe the pattern of presentation and to identify the factors that determine the long-term outcome in the treatment of traumatic dislocations and fracture-dislocations of the hip at Enugu, Nigeria. METHODS: The case notes of all the patients that presented with traumatic dislocations and fracture-dislocations of the hip between January 2003 and December 2007 were reviewed. The information extracted and analyzed included the patients' demographics, etiology of injury, time interval before reduction, associated injuries, treatment offered, complications and follow-up. Thompson-Epstein classification was used to grade the posterior hip dislocations. The outcome of treatment was evaluated using the clinical and radiological criteria proposed by Epstein (1974). Three patients with incomplete data and two patients with central fracture dislocation were excluded from this study. RESULTS: Forty-eight patients with 50 hip dislocations were analyzed. The age range was 12 years to 67 years with a mean age of 34.8 years. Thirty-nine patients (81.3%) were males and 9 (18.7%) were females. Road-traffic accident was the leading cause of traumatic hip dislocation in this series, 44 cases (91.6%). Posterior dislocation occurred in 48 hips (96%) while anterior dislocation occurred in 2 hips (4%). Forty-seven hips (94%) were treated by primary closed reduction, two hips (4%) were treated with open reduction and one patient (2%) had Girdlestone excision arthroplasty. Thirty-six hips (73.5%) were reduced with 12 hours of the injury. Concomitant injuries were found in 37 patients (77%). The follow up period ranged from 10 months to 36 months with a mean follow up period of 15 months. Post-traumatic osteoarthritis occurred in 2 hips (4%) avascular necrosis of the femoral head was seen in 2 hips (4%). Five patients had sciatic nerve paresis while there was recurrence in one hip. No mortality was recorded. CONCLUSION: Traumatic dislocations and fracture-dislocations of the hip are severe injuries caused mostly by high-speed motor-vehicular accidents. Young adult males are most commonly affected, and there is a high rate of concomitant injuries. Excellent results can be achieved by early and stable closed reduction of these injuries with immobilization of the affected hips.

Interpreting neonatal hip sonography: intraobserver and interobserver variability.

The purpose of this study is to state the reliability of neonatal hip ultrasound interpretation, defining the intra and interoperator variability in the evaluation of the scans. We considered a sample of 2071 scans (coming from 798 patients who attended the screening programme for hip dysplasia), which were interpreted by the operator who obtained and read the images at the screening time and then by a different operator who saw the images for the first time. Both the intra and interoperator variability of α and ß angles' values resulted statistically not significative (intraclass correlation coefficient > 0.8) and determining a class shift (according to the Graf's classification) in a nonstatistically significative number of cases (agreement percentage >91% and Cohen's κ >0.8). Hip sonography can reliably detect hip dysplasia and the intra and interoperator variability in the interpretation of the exam is NS when the examination is correctly executed.

A classification system for hip disease in cerebral palsy.

In population-based studies, hip displacement affects approximately one-third of children with cerebral palsy (CP). Given the extreme range of clinical phenotypes in the CP spectrum, it is unsurprising that hip development varies from normality, to dislocation and degenerative arthritis. Numerous radiological indices are available to measure hip displacement in children with CP; however, there is no grading system for assessing hip status in broad categorical terms. This makes it difficult to audit the incidence of hip displacement, determine the relationship between hip displacement and CP subtypes, assess the outcome of intervention studies, and to communicate hip status between health care professionals. We developed a categorical, radiographic classification of hip morphology based on qualitative indices and measurement of the key continuous variable, the migration percentage of Reimers. One hundred and thirty-four radiographs were reviewed of 52 female and 82 male adolescents with CP who were at, or close to, skeletal maturity (mean age 16y 1mo [SD 1y 4mo] range 14y to 19y 1mo). Twenty-nine were classified at Gross Motor Function Classification System level I, 25 at level II, 27 at level III, 24 at level IV, and 29 at level V. A classification system was developed to encapsulate the full spectrum of hip morphology in CP, with and without intervention.

Total Hip Arthroplasty for Crowe Type IV Hip Dysplasia: Surgical Techniques and Postoperative Complications.

Total hip arthroplasty (THA) of Crowe type IV developmental dysplasia of the hip (DDH) is challenging. Although traditional (lateral, posterolateral, and posterior) THA approaches have been used with great anatomic success, they damage periarticular muscles, which are already quite weak in type IV DDH. The recently developed direct anterior approach (DAA) can provide an inter-nerve and inter-muscle approach for THA of type IV dysplasia hips. However, femur exposure with the DAA could be difficult during surgery and it is hard to apply femoral shortening osteotomy. THA techniques used for type IV DDH include anatomic hip center techniques (true acetabular reconstruction) and high hip center techniques, wherein an acetabulum is reconstructed above the original one. Although anatomic construction of the hip center is considered "the gold standard" treatment, it is impossible if the anatomical acetabular is too small and shallow. Procedures used to support type IV DDH reduction with anatomic hip center techniques include greater trochanter osteotomy, lesser trochanter osteotomy, and subtrochanteric osteotomy. However, these techniques have yet to be standardized, and it is unclear which is best for type IV DDH. One-state and two-state non-osteotomy reduction techniques have also been introduced to treat type IV DDH. Potential complications of THA performed in patients with type IV DDH include leg length discrepancy (LLD), peri-operative femur fracture, nonunion of the osteotomy site, and nerve injury. It is worth noting that nowadays an increasing number of Crowe type IV DDH patients are more sensitive to postoperative LLD.

Traumatic hip fracture-dislocation: A middle-term follow up study and a proposal of new classification system of hip joint associated injury.

Traumatic hip fracture dislocation is a rare injury associated with high-energy trauma. Most of these injuries should be surgically treated. Hip dislocation is an orthopaedic emergency and reduction must be performed within 6-8 hours of trauma. We performed a retrospective analysis of 69 patients with "hip joint associated injuries", treated between January 2002 and December 2016. 33 patients were assessed at a mean follow-up of 36.9 months (range 18-132) after surgery. We propose a new classification system in which, different patterns of fracture (head and/or neck and/or acetabular) are described according to different types of hip dislocation. This anatomical-descriptive classification system is based on the concept of hip as a complex anatomical district and contains all possible traumatic injuries associated with hip dislocation. It includes isolated hip dislocation, hip dislocation with femoral head or neck fracture or hip dislocation with acetabular fracture and femoral head fracture. There are 4 groups: Each one of the previous groups is composed by different subgroups. Post-traumatic osteoarthritis is the most common complication of these hip injuries, followed by avascular necrosis of femoral head and heterotopic ossification. The bad prognosis depends on the type of trauma rather than surgical treatment.

[Treatment of femoral neck fractures]. / Behandlung der Schenkelhalsfrakturen.

Due to the high incidence (600-900 patients/year >65 years old), the expected increase in frequency by a factor of five by 2050, and the proportionately shrinking capacity in trauma centers, femoral neck fractures are relevant to health care both economically and politically. Surgical treatment within 6 h improves results of osteosynthesis, within 24 h reduces general complications, and within 48 h reduces mortality. The literature displays great regional differences in methods and results. There is however general agreement that the hip joint should be preserved in young, active patients, regardless of fracture type and dislocation and that endoprosthesis is desirable for elderly patients with severe dislocation. The controversies begin with compressed fracture, determination of the degree of dislocation, and age and physical condition of patients who would profit from endoprosthesis. Total endoprostheses show better results in more active patients than do hemiarthroconstructions. Cemented endoprostheses are preferable in older patients due to their better function and lower postoperative pain. The DGU recommends prophylactic osteosynthesis for impacted fracture and osteosynthesis for nondislocated fracture or when closely following slightly dislocated fracture.

Treatment of Graf Type IIa Hip Dysplasia: A Cut-off Value for Decision Making

Background: The rate of spontaneous normalization in type IIa hips is reported to be high, whereas dysplsia persists or worsens in 5%-10% of cases. Aims: To evaluate the natural course of type IIa hips using Graf's own perspective of physiological immaturity and maturational deficit. Study Design: A single center, retrospective cohort study. Methods: This was an institutional review board-approved retrospective review of all patients diagnosed with type IIa hip dysplasia at a single institution from 2012 to 2014. All patients included in the study had hip ultrasonography at about 6 weeks and 3 months of age. To assess reliability in α and ß angles, ultrasonography measurements were carried out on the same image individually by all observers. The α and ß angles were used as the main outcome measurements to evaluate hip maturation at the last follow-up. A receiver operating characteristics curve was drawn at the 3 month ultrasonography to evaluate the cut-off values for α and ß angles for persistent dysplasia. Results: Sixty-four patients and 88 affected hips (63% unilateral and 37% bilateral) were included. The mean age at diagnosis was 6.4±2.7 weeks. Fifty-four hips were type IIa(+) (physiologically immature) and 34 hips were type IIa(-) (maturational deficit) at the initial ultrasonography evaluation. Improvement to type I was seen in 52 type IIa(+) and 17 type IIa(-) hips. Receiver operating characteristic analyses showed that patients do well if the α angle was >55° (area under the curve: 0.86; p<0.001 for the left hip and area under the curve: 0.72; p=0.008 for the right hip). Conclusion: The cut-off α angle value of 55° on initial ultrasonography should be considered to prevent future dysplasia. An α angle <55° on the initial ultrasonography was an independent predictor of worsening sonographic findings.

Bony reconstruction of hip in cerebral palsy children Gross Motor Function Classification System levels III to V: a systematic review.

Hip dislocation is a common source of disability in cerebral palsy children. It has been remedied by various reconstructive procedures. This review aims at providing the best evidence for bony reconstructive procedures in cerebral palsy hip migration. The literature extraction process yielded 36 articles for inclusion in this review. There is fair evidence to indicate that the comparative effectiveness of femoral versus combined pelvifemoral reconstruction favours pelvifemoral reconstruction. All except one were retrospective articles with a significant degree of selection and performance bias and confounding variables that limited the validity and generalizability of the conclusions. The findings of this systematic review provide fair evidence for the use of adequate soft tissue and combined pelvifemoral reconstruction in the management of hip migration in none and minimally ambulatory cerebral palsy children in the short and long term. This has been shown in studies with a summed sizable patient population. There is limited evidence available that would support the use of soft-tissue and isolated femoral reconstruction. In the context of these retrospective and biased studies, it is extremely difficult to identify, with great precision, predictors of surgical success. Future studies should consider prospective designs that allow for bias control, strict patient selection criteria and incorporation of validated quality-of-life scales.

Evidence of validity for the hip outcome score.

PURPOSE: The purpose of this study was to offer evidence of validity for the Hip Outcome Score (HOS) based on internal structure, test content, and relation to other variables. METHODS: The study population consisted of 507 subjects with a labral tear. Internal structure was evaluated by use of factor analysis and coefficient alpha. Test content was evaluated by use of item response theory. Pearson correlation coefficients were used to assess relations between the Short Form 36 and the HOS. RESULTS: The mean subject age was 38 years (range, 13 to 66 years), with 232 male and 273 female subjects. Of the subjects, 263 (52%) underwent arthroscopic surgery. Factor analysis found that 17 of 19 items on the activities-of-daily-living (ADL) subscale loaded on 1 factor. The 2 items that did not fit the 1-factor model were omitted from further testing. All 9 items on the sports subscale loaded on 1 factor. The coefficient alpha values were .96 and .95 for the ADL and sports subscales, respectively. The errors associated with a single measure were +/-4.6 and +/-3.8 points for the ADL and sports subscales, respectively. Item response theory found that all items contributed to their test information curves and were potentially responsive. The correlations between the HOS and Short Form 36 measures of physical function were significantly different than their correlation to measures of mental functioning (P < .005). CONCLUSIONS: The results of this study provide evidence of validity to support the use of the HOS ADL and sports subscales for individuals with labral tears. This includes individuals who underwent arthroscopic surgery, as well as those who did not. Specifically, the results of this study found that the HOS ADL and sports subscales were unidimensional, had adequate internal consistency, were potentially responsive across the spectrum of ability, and contributed information across the spectrum of ability. In addition, scores obtained by the HOS related to measures of function and did not relate to measures of mental health. LEVEL OF EVIDENCE: Level III, development of diagnostic criteria with nonconsecutive patients.

Ultrasonographic screening for developmental dysplasia of the hip in infants. Reproducibility of assessments made by radiographers.

We studied the reproducibility of ultrasonographic screening examination of the hip when read by diagnostic radiographers. In order to determine interobserver variability, 200 ultrasonograms were classified according to Graf's method by five observers (four radiographers and one radiologist). The kappa values for interobserver variability indicated moderate agreement (kappa 0.47) for the exact Graf classification and substantial agreement (kappa 0.65) for the classification of normal (type I) versus abnormal (type IIa-IV). Agreement was significantly different for normal, immature and abnormal hips. Comparison of the findings in our interobserver study with existing information based on other examinations and treatment revealed that only a small number of infants with mildly dysplastic hips would have been typed as normal by some observers as a result of observer variability. In conclusion, the interobserver agreement on the ultrasound assessment of the hip was good enough for screening purposes. Observer variability did not result in any severe cases being missed.

Combined intertrochanteric and Chiari pelvic osteotomies for hip dysplasia.

Thirty-two dysplastic hips with secondary osteoarthritis, in 28 patients aged 18 to 42 years, were treated by combined intertrochanteric and Chiari osteotomy. They were followed up for 2.5 to 10 years. Pain was the main presenting symptom in all the patients. The indication for surgery was based on the severity of disease with respect to congruency, secondary degenerative change and degree of dysplasia. The average pre-operative Harris hip score was 47.7 and the majority had severe dysplasia with degenerative changes. On final review the average score was 88. The radiographic appearances of degenerative arthritis regressed in 72% of hips and dysplasia was improved in all cases. The results of this conservative form of surgery are better in hips with less severe dysplasia and mild secondary degenerative change.

Prognosis in Perthes' disease: a comparison of radiological predictors.

We compared the prognostic value of the Catterall grouping, the Salter-Thompson grading, the arthrographic shape of the femoral head, and the Herring lateral pillar grouping during the fragmentation stage of Perthes' disease in 73 patients with 81 affected hips. Radiographs were available for study from the onset of the disease until skeletal maturity. We used the Stulberg classification to assess outcome. The Herring grade and arthrographic sphericity proved to be the best predictors of final outcome. Combining these two values further increased the predictive value. All but one patient in Herring group A achieved an excellent outcome. In Herring group B, the age of the child and the sphericity of the femoral head influenced the end result. If the child was less than seven years old at the onset of symptoms the prognosis was invariably good and all spherical hips in group B had a good outcome with Stulberg grades 1 or 2. Moderately and severely deformed hips on arthrography resulted in Stulberg 3 and 4 hips. None of the hips in Herring group C had a normal appearance at maturity and the outcome was not significantly influenced by the age at onset or the arthrographic appearance.

Bilateral posterior hip dislocations with femoral head fractures.

An unusual case of bilateral posterior fracture-dislocation of the hip (Pipkin Type IV) occurred in a 63-year-old man with Paget's disease of the pelvis. Other injuries included a displaced humeral shaft fracture and patellar ligament disruption. Bilateral cemented total hip arthroplasty was performed to avoid the need for prolonged immobilization. Postoperative low-dose irradiation was used because of the risk of heterotopic ossification.

Intermediate-term experience of Pipkin fracture-dislocations of the hip.

The purpose of this study was to review our intermediate-term experience with posterior fracture-dislocations of the hip. We evaluated the accuracy of the Pipkin and Brumback classification schemes as predictors of outcome, assessed the importance of certain treatment variables, and determined the complication rates of this injury in a group of 33 patients followed for an average of 49 months. The overall results were 67% good, 18% fair, and 15% poor, with no excellent results. The Pipkin classification scheme was a useful predictor of outcome because patients with less severe Pipkin 1 or 2 injuries had statistically significant better outcomes than did those who sustained Pipkin 3 or 4 injuries (p < 0.02). Due to a large number of subgroups, we could not demonstrate the usefulness of the Brumback classification system as a predictor of outcome. There were no statistically significant differences in outcome or complication rates when comparing time with hip reduction, definitive operative intervention, or anatomic operative approach to injury. Our study represents the second largest report on posterior dislocation of the hip associated with femoral head fracture. Although outcome of the patients in our series is not outstanding, the 67% good results represent a significant improvement over all previous reports with large numbers of patients. We demonstrate significant improvement in prognosis when treatment goals for these injuries include anatomic reduction, restoration of hip joint stability, and removal of all interposed bone fragments.