This study examined the relationship between the cross-over sign and the true three-dimensional anatomical version of the acetabulum. We also investigated whether in true retroversion there is excessive femoral head cover anteriorly. Radiographs of 64 hips in patients being investigated for symptoms of femoro-acetabular impingement were analysed and the presence of a cross-over sign was documented. CT scans of the same hips were analysed to determine anatomical version and femoral head cover in relation to the anterior pelvic plane after correcting for pelvic tilt. The sensitivity and specificity of the cross-over sign were 92% and 55%, respectively for identifying true acetabular retroversion. There was no significant difference in total cover between normal and retroverted cases. Anterior and posterior cover were, however, significantly different (p < 0.001 and 0.002). The cross-over sign was found to be sensitive but not specific. The results for femoral head cover suggest that retroversion is characterised by posterior deficiency but increased cover anteriorly

Aims

Our retrospective analysis reports the outcome of patients operated for slipped capital femoral epiphysis using the modified Dunn procedure. Results, complications, and the need for revision surgery are compared with the recent literature.

Introduction. Ascertaining the etiology of hip pain in young patients can be challenging. Osteoid osteoma about the hip has only been described in case reports and small case series in this sub-population. This study assessed the clinical course, radiologic findings, and treatment approaches in a large series of pediatric osteoid osteoma cases about the hip. Potential diagnostic and treatment pitfalls were identified. Methods. A single-center tertiary care departmental database was queried for all cases of osteoid osteoma seen between Jan 1, 2003 and December 31, 2015. Medical records were reviewed to identify those with lesions identified within or around the hip joint. Clinical, demographic, and radiologic data were analyzed. Results. Fifty children and adolescents (56% female, mean age 12.4 years, range 3–19 years) were identified with osteoid osteoma about the hip. The femoral neck was the most common lesion location (38%), and pain in the hip was the most common presenting chief complaint (60%). Night pain (90%) and symptom relief with NSAIDs (88%) were extremely common, though not universally reported. Sclerosis and/or cortical thickening was visible in 58% of radiographs, though a lucent nidus was visible in only 42%. Thirty patients (60%) underwent MRI, 27 of which were available for review, with focal peri-lesional edema as a universal finding. Amongst intracapsular lesions (n=17, 63%), common findings included medial retinacular thickening (33%), synovitis (45%) and effusion (76%). In the 43 patients (48%) who underwent CT, a diagnostic lucent nidus was a universal finding. Initial alternative diagnoses were recorded in 46% of cases, including, in order of decreasing frequency, femoro-acetabular impingement, minor trauma, hip synovitis, ‘growing pain’, stress fracture, and infection. Abnormal hip range of motion, positive impingement signs, and global synovitis on MRI scan were found to be associated with alternative diagnosis. On multivariate regression analysis, only abnormal hip ROM was independently predictive of alternative diagnosis. Delay in diagnosis of >6 months was seen in 43% of patients. Three patients underwent preceding operative procedures for other hip diagnoses, but had persistent hip pain until the osteoid osteoma was treated. Forty-one patients (82%) ultimately underwent radiofrequency ablation (RFA), and 1 open osteoid osteoma resection was performed. Of those who underwent RFA, 93% achieved complete symptom resolution, with 2 of 3 patients without symptom resolution undergoing revision RFA procedure, 1 of which led to symptom resolution. Complications of treatment included 1 case of deep infection along an RFA track, requiring operative debridement, 1 case of transient weakness and paresthesias in the involved extremity, and 1 case of fracture at the RFA site, requiring ORIF. Conclusions. Alternative andelayed diagnoses are common in osteoid osteoma about the hip, with femoro-acetabular impingement representing the most common alternative initial diagnosis in our series. While varying presenting complaints and nonspecific MRI findings may contribute to diagnostic uncertainty, night pain was present in the vast majority of cases and CT scans provided definitive diagnosis in all patients who received them. As increasing numbers of young, active patients are being evaluated for various causes of hip pain, such as femoro-acetabular impingement, osteoid osteoma should not be overlooked in the differential diagnosis of pain about the hip

MCID and PASS are thresholds driven from PROMS to reflect clinical effectiveness. Statistical significance can be derived from a change in PROMS, whereas MCID and PASS reflect clinical significance. Its role has been increasingly used in the world of young adult hip surgery with several publications determining the thresholds for Femoro-acetabular impingement FAI. To our knowledge MCID and PASS for patient undergoing PAO for dysplasia has not been reported. 593 PAOs between 1/2013 and 7/2023 were extracted from the Northumbria Hip Preservation Registry. Patients with available PROMS at 1year and/or 2years were included. PAOs for retroversion, residual Perthes and those combined with FO were excluded. MCID was calculated using the distribution method 0.5SD of baseline score(1). PASS was calculated using anchor method, ROC analysis performed, and value picked maximizing Youden index. A Logistic Regression analysis was performed to determine which independent variables correlated with achieving MCID and PASS. The MCID threshold for iHOt12 was 8.6 with 83.4 and 86.3 % of patients achieved it at 1 and 2 years respectively. The PASS score at 1 and 2 year follow up was 43 and 44 respectively, with 72.6 and 75.2% achieving it at 1 and 2 year postop. At 2 years a Higher preop iHOT 12 was associated with not achieving MCID and PASS (p<0.05). Preop acetabular version was negatively correlated with achieving MCID and previous hip arthroscopy was negatively correlated with PASS. The % of patients achieving MCID and PASS mimics that of FAI surgery (2). The negative correlation with preop iHOT12 reaffirms the importance of patient selection. The negative correlation of hip arthroscopy highlights the importance of having a high index of suspicion for dysplasia prior to hip arthroscopy and poorer outcomes of patients with mixed CAM and dysplasia pathology

Introduction. Acetabular and spino-pelvic (SP) morphological parameters are important determinants of hip joint dynamics. This study aims to determine whether acetabular and SP morphological differences exist between hips with and without cam morphology and between symptomatic and asymptomatic hips with cam morphology. Patients/Materials & Methods. A prospective cohort of 67 patients/hips was studied. Hips were either asymptomatic with no cam (Controls, n=18), symptomatic with cam (n=26) or asymptomatic with cam (n=23). CT-based quantitative assessments of femoral, acetabular, pelvic and spino-pelvic parameters were performed. Measurements were compared between controls and those with a cam deformity, as well as between the 3 groups. Morphological parameters that were independent predictors of a symptomatic Cam were determined using a regression analysis. Results. Hips with cam deformity had slightly smaller subtended angles superior-anteriorly (87° Vs 84°, p=0.04) and greater pelvic incidence (53° Vs 48°, p=0.003) compared to controls. Symptomatic Cams had greater acetabular version (p<0.01), greater subtended angles superiorly and superior-posteriorly (p=0.01), higher pelvic incidence (p=0.02), greater alpha angles and lower femoral neck-shaft angles compared to asymptomatic cams (p<0.01) and controls (p<0.01). The four predictors of symptomatic cam included antero-superior alpha angle, femoral neck-shaft angle, acetabular depth and pelvic incidence. Discussion. Symptomatic hips had a greater amount of supero-posterior coverage; which would be the contact area between a radial cam and the acetabulum, when the hip is flexed to 90°. Furthermore, individuals with symptomatic cam morphology had greater PI. Acetabular- and SP parameters should be part of the radiological assessment of femoro-acetabular impingement. Conclusion. Because of the association between a high PI and an increased risk of hip OA (also shown to be increased with c-FAI), the relationship between the PI and FAI should be taken into consideration in prospective longitudinal studies looking at factors influencing the formation of cam morphology as well as those at risk of developing symptoms and degenerative changes

Aims

The aim of this study was to evaluate the long-term clinical and radiographic outcomes of the Birmingham Interlocking Pelvic Osteotomy (BIPO).

This study investigates and defines the topographic anatomy of the medial femoral circumflex artery (MFCA) terminal branches supplying the femoral head (FH). Gross dissection of 14 fresh–frozen cadaveric hips was undertaken to determine the extra and intracapsular course of the MFCA’s terminal branches. A constant branch arising from the transverse MFCA (inferior retinacular artery; IRA) penetrates the capsule at the level of the anteroinferior neck, then courses obliquely within the fibrous prolongation of the capsule wall (inferior retinacula of Weitbrecht), elevated from the neck, to the posteroinferior femoral head–neck junction. This vessel has a mean of five (three to nine) terminal branches, of which the majority penetrate posteriorly. Branches from the ascending MFCA entered the femoral capsular attachment posteriorly, running deep to the synovium, through the neck, and terminating in two branches. The deep MFCA penetrates the posterosuperior femoral capsular. Once intracapsular, it divides into a mean of six (four to nine) terminal branches running deep to the synovium, within the superior retinacula of Weitbrecht of which 80% are posterior. Our study defines the exact anatomical location of the vessels, arising from the MFCA and supplying the FH. The IRA is in an elevated position from the femoral neck and may be protected from injury during fracture of the femoral neck. We present vascular ‘danger zones’ that may help avoid iatrogenic vascular injury during surgical interventions about the hip.

Cite this article: Bone Joint J 2015;97-B:1204–13.