Femoral Version Research Articles

Femoral version deformities alter joint reaction forces in dysplastic hips during gait

Developmental dysplasia of the hip (DDH) causes hip instability and early-onset osteoarthritis. The focus on pathomechanics in DDH has centered on the shallow acetabulum, however there is growing awareness of the role of femoral deformities in joint damage. The objective of this study was to determine the influence of femoral version (FV) on the muscle and joint reaction forces (JRFs) of dysplastic hips during gait. Magnetic resonance images, in-vivo gait data, and musculoskeletal models were used to calculate JRFs and simulate changes due to varying FV deformities. Rotation about the long axis of the femur was added in the musculoskeletal models to simulate FV values from −5° (relative retroversion) to + 35° (increased anteversion). In our simulations, FV deformities caused the largest changes to the anteroposterior and resultant JRFs. From a normal FV of 15°, a 15° increase in femoral anteversion caused JRFs to be less posterior in early stance (Δ = 0.43 ± 0.22 xbodyweight) and more anterior in late stance (Δ = 0.60 ± 14 xbodyweight). Relative retroversion caused anteroposterior changes that were similar to anteversion in early stance but opposite in late stance. Resultant JRFs experienced the largest changes during late stance where anteversion raised the peak by 0.48 ± 0.15 xbodyweight and relative retroversion lowered the peak by 0.32 ± 0.30 xbodyweight. Increasing anteversion increased hip flexor and abductor muscle forces, which caused the changes in JRFs. Identifying how FV deformities influence hip joint loading can elucidate their role in the mechanisms of hip degeneration in patients with DDH.

Translated article] Correlation between femoral version and severity of hip dysplasia in patients with advanced osteoarthritis prior to total hip arthroplasty

IntroductionDevelopmental dysplasia of the hip (DDH) is a condition which comprises a number of joint abnormalities, including modifications in femoral version and neck-shaft angle (CCD), as well as a probable progression to osteoarthritis in certain cases. The main objective of this research was to find a correlation between femoral version and severity of DDH in patients with advanced osteoarthritis prior to joint replacement, which has not been previously reported. A secondary aim was to describe the modification of CCD as the severity of DDH increases. Materials and methodPatients over the age of 15 with dysplastic hips and severe osteoarthritis prior to total hip arthroplasty were assessed between March 2018 and February 2019. Cases with any previous hip surgery were excluded. Anteroposterior pelvis X-rays and femoral computed tomography (CT) were performed; femoral version was measured in CT and CCD was evaluated both in X-rays (2 observers: A and B) and CT (one observer: musculoskeletal radiologist). Severity of DDH was defined by observers A and B according to Crowe classification in X-rays. Statistical analysis was performed on SPSS v.21. Shapiro–Wilk test was used to confirm a normal data distribution. Intraclass correlation coefficient (ICC) determined the level of agreement between observers A and B. Pearson test assessed the correlation between femoral version and Crowe classification (positive if >0.5). Student's t test evaluated the statistical significance, which was defined as P<0.05. ResultsOne-year assessment; 42 patients (54 hips), 76% women. Mean age 52.7 years. 45 hips completed the imaging set, 9 hips were assessed only with X-rays. 48%, 16%, 7% and 28% were classified as Crowe I, II, III and IV (100% interobserver agreement). Crowe classes were grouped as I, II/III and IV due to a low number of cases classified as II and III. Mean femoral version was 21.73°, 26.8° and 43.58°, respectively. ICC between observers A and B for CCD measured in X-rays was 0.96. Mean CCD measured in X-rays for each group (I, II/III and IV) was 148.11°, 147.7° and 147°, and in CT was 131.21°, 127.9° and 122.14°, respectively. A significant difference was found in femoral version between groups I and IV (P=0.0002) and II/III and IV (P=0.042). Pearson correlation between femoral version and severity of DDH was positive (r=0.52; P=0.0002). A significant difference between CCD measured in CT was found between groups I and IV (P=0.003). ConclusionsA significant increase in femoral version related to severity of DDH and a positive correlation between these 2 features were found. Furthermore, a significant decrease in CCD between groups I and IV measured in CT was revealed. These findings would be helpful for preoperative planning of total hip replacement in osteoarthritis secondary to DDH, because once the surgeon has assessed the severity of DDH on X-rays or CT, an increased femoral version could be expected. Therefore, availability of specific implants such as conic, modular or cemented stems is critical, in order to modify the femoral anteversion to normal values in the most severe cases.

CT measures of femoral and tibial version and rotational position of femoral and tibial components of knee replacements: limitations in reliability and suitability for routine clinical practice

ObjectivesRotational malalignment of knee replacements as measured on CT is understood to be associated with poor outcomes. The aim of this study is to measure the inter-rater and intra-rater reliability of measures of femoral and tibial version in the native arthritic knee and postoperative TKR component position using CT.MethodsEighty patients underwent CT of the knee before and after total knee replacement. Preoperative femoral and tibial version and component rotation were independently measured by two musculoskeletal radiologists.ResultsMean differences between and within raters were small (< 1.6°). Maximum 95% limits of agreement for inter-rater and intra-rater comparisons were 8.1° and 7.6° for preoperative femoral version, 9.0° and 7.9° for postoperative femoral rotation, 26.0° and 20.5° for preoperative tibial version, and 24.9° and 23.6° for postoperative tibial rotation respectively. Postoperative ICCs varied from 0.68 to 0.81 (lower 95% CI:0.55–0.72) for both intra- and inter-rater comparisons. Preoperative ICCs were lower: 0.55–0.75 (lower 95% CI:0.40–0.65).ConclusionThe lower 95% confidence level for ICC of version and rotational measurements using the Berger protocol of TKRs on CT are all less than 0.73 and that the normal range of differences between observers is up to 9° for the femoral component and 26° for the tibial component. This suggests that CT measurements derived from the Berger protocol may not be consistent enough for clinical practice.Key Points• CT is commonly used to measure the rotational profile of knee replacements in symptomatic patients using the Berger protocol.• The limits of agreement for both femoral and tibial component rotation are wide even for experienced observers.• CT measurements of the rotation of knee arthroplasty are not reliable enough for routine clinical use.

Combination of Anterior Acetabular Coverage and Femoral Head Shape Predicts Femoroacetabular Impingement After Periacetabular Osteotomy.

Femoroacetabular impingement (FAI) after periacetabular osteotomy (PAO) may be affected by both anterior acetabular coverage and femoral head shape. This study aimed to radiographically evaluate the relationship of the combination of acetabular coverage and femoral head shape with the occurrence of FAI after curved PAO. In this study, 76 hip joints from patients with symptomatic developmental dysplasia of the hip underwent curved PAO. The relationship between the combined postoperative anterior center-edge and alpha angles (ie, the combination angle) and the occurrence of postoperative FAI was evaluated. Clinical factors and the preoperative and postoperative 3-dimensional center-edge angles, acetabular versions, femoral versions, radiographic alpha angles of the femoral head, and the combination angle were measured and compared to clinical outcomes. The modified Harris Hip Scores, University of California, Los Angeles activity scores, and acetabular coverage angles were significantly improved following curved PAO. Receiver operator characteristic curve analysis demonstrated that the combination angle over 108° may be a predictive factor for the occurrence of FAI after curved PAO. Multivariate analysis demonstrated that an age <40 years (odds ratio 6.6, 95% confidence interval 1.2-36.4, P= .037) and a combination angle <108° (odds ratio 9.2, 95% confidence interval 1.7-50.0, P= .010) were significantly associated with modified Harris Hip Scores ≧90 points. A combination angle >108° may be a predictive factor for the occurrence of FAI after curved PAO and impaired clinical outcomes. To avoid postoperative FAI, we propose that osteochondroplasty of the femoral head should be performed for patients with preoperative combination angles >90°.

Anterior acetabular coverage and femoral head-neck measurements predict postoperative anterior impingement: A simulation study.

The aim of this simulation study was to evaluate the relationship of elements of anterior acetabular coverage and femoral head-neck shape with the occurrence of postoperative anterior impingement after curved periacetabular osteotomy (PAO). Sixty-two patients with symptomatic developmental dysplasia of the hip who had undergone curved PAO were selected. The likelihood of developing postoperative anterior impingement was explored through simulations of the range of motion by collision detection of the pelvis and femur. Postoperative anterior impingement was defined as impingement that occurred during postoperative bone flexion <105° or postoperative internal rotation <20° at 90° flexion. The three-dimensional center-edge (CE) angles, acetabular and femoral versions, radiographic alpha angles of the femoral head, combination angles of anterior CE and alpha angles, and combined anteversions of acetabular and femoral versions were compared between patients with postoperative anterior impingement and nonimpingement. A receiver operator characteristic (ROC) analysis was conducted to determine thresholds of the examined radiographic parameters and calculate their accuracy for predicting postoperative anterior impingement. A multivariate analysis was performed to test whether combined anteversion, anterior CE angle, and combination angle are associated with excellent modified Harris Hip Scores (mHHSs).ROC analysis demonstrated a combination angle ≥108° was predictive of the occurrence of postoperative anterior impingement after curved PAO, which can lead to impaired clinical outcomes. Conversely, a combination angle <108° was significantly associated with mHHS ≥ 90 points. To avoid postoperative anterior impingement, osteochondroplasty of the femoral head or anterior CE angle control should be performed for patients with preoperative combination angles ≥90°.

Femoral neck shaft angle is not correlated with femoral version: A retrospective study of computed tomography scans

BackgroundAn understanding of femoral anteversion and neck-shaft angle (NSA) is essential to deliver optimal orthopaedic surgical care. Despite the importance, there is little research examining the relationship between femoral anteversion and the NSA in an adult population. This study sought to determine if there is a correlation between femoral neck shaft angle and version in skeletally mature adults using computed tomography (CT) scanograms. MethodsBetween January 2010 and June 2017, all skeletally mature patients who had received a CT scanogram of the lower extremity were reviewed. Exclusion criteria included: (1) radiographic evidence of osteoarthritis, (2) history of hip, femur, or knee surgery or trauma, (3) and anatomic abnormalities of the proximal femur including prior slipped capital femoral epiphysis or Legg-Calvé-Perthes disease. Both femoral version and NSA were measured by a musculoskeletal fellowship trained radiologist using CT scanograms. Correlation between femoral version and NSA was determined using coefficient of determination (R2) and Pearson correlation coefficient (r) for the group as a whole and for each sex. ResultsThere was no statistical correlation between femoral version and NSA for either the entire cohort or for each sex. For the entire cohort, R2 = 0.0016 and r was 0.04 (p=0.45), for females, R2 = 0.0005 and r was 0.0224 (p=0.72), and for males, R2 = 0.0342 and r was 0.185 (p=0.07). ConclusionThere was no correlation between femoral version and NSA. This finding is beneficial for surgeons to understand the proximal femoral anatomy. Patients with an increased femoral NSA should not be assumed to have increased femoral anteversion. Level of EvidenceLevel III, Retrospective Cohort Study

Generalized Joint Laxity Is Associated With Dynamic Hip Ultrasonography Measures in Female Athlete Patients Who Are Not Hypermobile.

To investigate ultrasound (US) femoroacetabular translation measurements in female athlete patients. A prospective cross-sectional study was conducted in female athlete patients <50 years. Demographic data, Beighton score/hypermobility status, and sport participation were collected. Hip dysplasia was determined using radiographic measurements (lateral center edge angle, anterior center edge angle, Tönnis angle); femoral version angles were measured with CT or MR. Femoroacetabular translation US measures included neutral (N), neutral flexed (NF), extension external rotation/apprehension (EER) positions. Maximal difference (delta) between US measures was calculated. 206/349 female hips were analyzed (median age 21.2 years [range, 12-49.5]). The primary sport group was performing arts (45%, 92/206). Mean Beighton score was 5.2 (SD, 2.5) with 61% (129/206) of hips exhibiting hypermobility (Beighton score ≥5). For each additional unit of Beighton score, N US measurement increased by 0.7 mm (β=0.7; 95% confidence interval [CI]=0.22-1.25; P < .001), NF by 1 mm ( = 0.9; 95% CI=0.3-1.43; P=.002) and EER by 0.8 mm ( = 0.8; 95% CI=0.27-1.37; P < .001) when adjusting for age and dysplasia status. A positive correlation was detected between NF (r=0.19; 95% CI=0.05-0.33; P=.007) and EER (r=0.19; 95% CI=0.05-0.32; P=.01) with Tönnis angle and a negative correlation between the delta and femoral version (r=-0.20; 95% CI=-0.35 to 0.03; P=.02). No difference in US measures was detected across sport groups (N [P=.24], NF [P=.51], EER [P=.20], delta [P=.07]). Beighton score was independently associated with dynamic US measures in female athlete patients who are not hypermobile when controlling for other factors.

Elimination of the Femoral Neck in Measuring Femoral Version Allows for Less Variance in Interobserver Reliability.

Background and Objectives: Producing consistent measures of femoral version amongst observers are necessary to allow for an assessment of version for possible corrective procedures. The purpose of this study was to compare two computed tomography (CT)-based techniques for the reliability of measuring femoral version amongst observers. Materials and Methods: Review was performed for 15 patients post-femoral nailing for comminuted (Winquist III and IV) femoral shaft fractures where CT scanograms were obtained. Two CT-based techniques were utilized to measure femoral version by five observers. Results: The mean femoral version, when utilizing a proximal line drawn down the center of the femoral head-neck through CT, was 9.50 ± 4.82°, while the method utilizing the head and shaft at lesser trochanter centers produced a mean version of 18.73 ± 2.69°. A significant difference was noted between these two (p ≤ 0.001). The method of measuring in the center of the femoral head and neck produced an intraclass correlation coefficient (ICC) of 0.960 with a 95% confidence interval lower bound of 0.909 and upper bound of 0.982. For the method assessing version via the center of the head and shaft at the lesser trochanter region, the ICC was 0.993 with a 95% confidence interval lower bound of 0.987 and an upper bound of 0.996. Conclusions: The method of measuring version proximally through a CT image of the femoral head–neck versus overlaying the femoral head with the femoral shaft at the most prominent aspect of the lesser trochanter produces differing version measurements by roughly 10° while yielding an almost perfect interobserver reliability in the new technique. Both techniques result in significantly high interobserver reliability.

Prediction of femoral head coverage from articulated statistical shape models of patients with developmental dysplasia of the hip.

Developmental dysplasia of the hip (DDH) is commonly described as reduced femoral head coverage due to anterolateral acetabular deficiency. Although reduced coverage is the defining trait of DDH, more subtle and localized anatomic features of the joint are also thought to contribute to symptom development and degeneration. These features are challenging to identify using conventional approaches. Herein, we assessed the morphology of the full femur and hemi-pelvis using an articulated statistical shape model (SSM). The model determined the morphological and pose-based variations associated with DDH in a population of Japanese females and established which of these variations predict coverage. Computed tomography (CT) images of 83 hips from 47 patients were segmented for input into a correspondence-based SSM. The dominant modes of variation in the model initially represented scale and pose. After removal of these factors through individual bone alignment, femoral version and neck-shaft angle, pelvic curvature, and acetabular version dominated the observed variation. Femoral head oblateness and prominence of the acetabular rim and various muscle attachment sites of the femur and hemi-pelvis were found to predict 3D CT-based coverage measurements (R2 = 0.5-0.7 for the full bones, R2 = 0.9 for the joint). Statement of Clinical Significance: Currently, clinical measurements of DDH only consider the morphology of the acetabulum. However, the results of this study demonstrated that variability in femoral head shape and several muscle attachment sites were predictive of femoral head coverage. These morphological differences may provide insight into improved clinical diagnosis and surgical planning based on functional adaptations of patients with DDH.

Femoroacetabular translation in female athletes and dancers assessed by dynamic hip ultrasonography

ObjectiveTo compare femoroacetabular (FA) translation between dancers and athletes with hip pain and between dancers with and without hip pain.MethodsIn this cross-sectional study, 171 female athletes and dancers with hip...

Assessment of Femoral Torsion on Magnetic Resonance Imaging is More Reliable Using Axial-Oblique Sequences Compared With Standard Axial Slices in Patients With Femoroacetabular Impingement Syndrome

To determine the agreeability of femoral torsion measurements on axial and oblique axial magnetic resonance imaging (MRI) sequences in patients with femoroacetabular impingement syndrome (FAIS). Patients who underwent primary hip arthroscopy for FAIS between January 2012 to January 2019 were identified. Inclusion criteria were all patients with an MRI scan containing the pelvis and knee imaging. MRI-based measurements of femoral torsion were performed on axial and oblique-axial slices by 2 raters, and inter-rater and intrarater reliability was assessed. Bland Altman plots were constructed to evaluate the agreeability between femoral torsion measurements performed using axial and oblique-axial slices. Bivariate correlation analyses were performed to assess the relationship between measurement methods on each respective scan. A linear regression was performed between measurements performed using axial and oblique-axial sequences. A total of 164 patients were included. The mean true-axial and oblique axial femoral torsion were 12.2° ± 9.9° and 11.1° ± 9.2°, respectively. The intrarater reliability for axial and oblique-axial measurements were 0.993 and 0.997, respectively. The inter-rater reliability for axial and oblique-axial measurements were 0.925 and 0.965, respectively. The number of differences within the limits of agreement for axial and oblique-axial femoral torsion measurements was 58.54%. On Pearson correlation analysis, strong positive correlations were found between oblique-axial measurements at multiple time points (r= 0.994, P<.001), as well as axial measurements at multiple time points (r= 0.986, P < .001). A strong positive correlation was found between axial and oblique-axial measurements (r= 0.894, P < .001). A significant regression equation indicated that for each additional increase in axial femoral torsion, the oblique-axial femoral torsion increased 0.837 (95% confidence interval 0.772-0.901). Femoral torsion values measured on oblique-axial sequences are smaller than on true-axial sequences. Femoral torsion measurements on axial and oblique-axial MRI sequences exhibit poor agreement. Oblique-axial sequences demonstrated greater measurement consistency at multiple timepoints. When evaluating torsional measurements, it is important to delineate which axial sequence was used, especially inpatients with suspected severe femoral antetorsion. Standardization of MRI femoral version protocols within one'spractice can ensure more consistent decision-making, especially in patients with suspected femoral antetorsion. Retrospective cohort, level III.

The Effect of Femoral and Acetabular Version on Outcomes Following Hip Arthroscopy: A Systematic Review.

Torsional hip deformities are common among patients undergoing hip arthroscopy. However, recent studies have suggested conflicting outcomes following arthroscopy in the setting of abnormal hip version. The purpose of this study was to systematically evaluate the literature and determine the impact of femoral and acetabular version on patient-reported outcomes following primary arthroscopic hip surgery. This study was conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. Studies investigating femoral and acetabular version in primary hip arthroscopy with clinical outcomes were identified, and data were extracted in duplicate. Overall, 11 studies met inclusion criteria and comprised 1,297 hips (726 femora and 571 acetabulae), with a mean patient age of 29.2 years (range, 14 to 74.7 years). In patients with acetabular retroversion, there was no significant difference, when compared with the normal acetabular version group, in the modified Harris hip score (mHHS), the Hip Outcome Score-Sports Specific Subscale (HOS-SSS), and visual analog scale (VAS) pain scores postoperatively. Among patients with femoral retroversion, in 2 of 3 studies, the authors reported no difference in mHHS postoperatively compared with patients with normal femoral version. In patients with high femoral anteversion, in 2 of 3 studies, the authors reported a significant difference in postoperative mHHS favoring patients with normal femoral version. Studies examining high femoral anteversion included patients with borderline hip dysplasia and patients who underwent concurrent psoas-lengthening procedures. Although the definition of the normal version of the hip varied within the literature, hip arthroscopy in patients with acetabular retroversion resulted in no difference in functional outcomes compared with patients with normal version. Postoperative functional outcomes in patients with femoral retroversion and high femoral anteversion were mixed, although the procedure was possibly less effective in high femoral anteversion combined with specific clinical scenarios. Further prospective studies based on standardized definitions and version analysis techniques would be useful in identifying the precise surgical indications for safe arthroscopic surgical procedures in patients with version abnormalities of the femur and acetabulum, particularly those with high femoral anteversion and retroversion. Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Correlación entre versión femoral y gravedad de displasia del desarrollo de cadera en pacientes con artrosis avanzada

IntroductionDevelopmental dysplasia of the hip (DDH) is a condition which comprises a number of joint abnormalities, including modifications in femoral version and neck-shaft angle (CCD), as well as a probable progression to osteoarthritis in certain cases. The main objective of this research was to find a correlation between femoral version and severity of DDH in patients with advanced osteoarthritis prior to joint replacement, which has not been previously reported. A secondary aim was to describe the modification of CCD as the severity of DDH increases. Materials and methodPatients over the age of 15 with dysplastic hips and severe osteoarthritis prior to total hip arthroplasty were assessed between March 2018 and February 2019. Cases with any previous hip surgery were excluded. Anteroposterior pelvis X rays and femoral computed tomography (CT) were performed; femoral version was measured in CT and CCD was evaluated both in X rays (2 observers: A and B) and CT (one observer: musculoskeletal radiologist). Severity of DDH was defined by observers A and B according to Crowe classification in X rays. Statistical analysis was performed on SPSS v.21. Shapiro-Wilk test was used to confirm a normal data distribution. Intraclass correlation coefficient (ICC) determined the level of agreement between observers A and B. Pearson test assessed the correlation between femoral version and Crowe classification (positive if >0.5). Student's t test evaluated the statistical significance, which was defined as P<0.05. ResultsOne-year assessment; 42 patients (54 hips), 76% women. Mean age 52.7 years. 45 hips completed the imaging set, 9 hips were assessed only with X rays. 48%, 16%, 7% and 28% were classified as Crowe I, II, III and IV (100% interobserver agreement). Crowe classes were grouped as I, II/III and IV due to a low number of cases classified as II and III. Mean femoral version was 21.73°, 26.8° and 43.58°, respectively. ICC between observers A and B for CCD measured in X rays was 0.96. Mean CCD measured in X rays for each group (I, II/III and IV) was 148.11°, 147.7° and 147°, and in CT was 131.21°, 127.9° and 122.14°, respectively. A significant difference was found in femoral version between groups I and IV (P=0.0002) and II/III and IV (P=0.042). Pearson correlation between femoral version and severity of DDH was positive (r=0.52; P=0.0002). A significant difference between CCD measured in CT was found between groups I and IV (P=0.003). ConclusionsA significant increase in femoral version related to severity of DDH and a positive correlation between these 2features were found. Furthermore, a significant decrease in CCD between groups I and IV measured in CT was revealed. These findings would be helpful for preoperative planning of total hip replacement in osteoarthritis secondary to DDH, because once the surgeon has assessed the severity of DDH on X rays or CT, an increased femoral version could be expected. Therefore, availability of specific implants such as conic, modular or cemented stems is critical, in order to modify the femoral anteversion to normal values in the most severe cases.

The walls of the femoral neck as an auxiliary tool for femoral stem positioning.

Femoral anteversion is a major contributor to functionality of the hip joint and is implicated in many joint pathologies. Accurate determination of component version intraoperatively is a technically challenging process that relies on the visual estimation of the surgeon. The following study aimed to examine whether the walls of the femoral neck can be used as appropriate landmarks to ensure appropriate femoral prosthesis version intraoperatively. We conducted a retrospective study based on 32 patients (64 hips) admitted to our centre between July and September 2020 who had undergone a CT scan of their lower limbs. Through radiological imaging analysis, the following measurements were performed bilaterally for each patient: anterior wall version, posterior wall version, and mid-neck femoral version. Anterior and posterior wall version were compared and evaluated relative to mid-neck version, which represented the true version value. Mean anterior wall anteversion was 20° (95% CI, 17.6-22.8°) and mean posterior wall anteversion was -12° (95% CI, -15 to -9.7°). The anterior walls of the femoral neck had a constant of -7 and a coefficient of 0.9 (95% CI, -9.8 to -4.2; p < 0.0001; R2 0.77).The posterior walls of the femoral neck had a constant of 20 and a coefficient of 0.7 (95% CI, 17.8-22.5; p < 0.0001; R2 0.60). Surgeons can accurately obtain femoral anteversion by subtracting 7° from the angle taken between the anterior wall and the posterior femoral condyles or by adding 20° to the angle taken between the posterior wall and the posterior femoral condyles.

Little or No Differences in Hip Morphology Between Professional Dancers and Controls: A Systematic Review.

To systematically evaluate and synthesize the literature on bony hip morphology of professional dancers, as measured by 2D or 3D imaging techniques. A literature search was performed on November 20, 2020, using MEDLINE, Embase, and Cochrane. Clinical studies were eligible if they reported on hip morphology of professional dancers. Two independent reviewers screened titles, abstracts, and full-texts to determine eligibility; performed data extraction; and assessed the quality of eligible studies according to the Joanna Briggs Institute (JBI) checklist. This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. The search returned 1384 records; 449 were duplicates, 923 were excluded after title/abstract/full-text screening, and 12 were eligible, reporting on 447 individuals (352 professional dancers and 95 controls). The JBI checklist indicated that 11 studies scored ≥4 points. For professional dancers, lateral center edge angle was 22.4 to 30.8 degrees, acetabular version was 6.7 to 13.5 degrees, neck-shaft angle was 132.5 to 139.5 degrees, and femoral version was 4.7 to 14.4 degrees. Statistically significant differences between dancers and controls were found in some of the studies for acetabular version, neck-shaft angle, and femoral version, although only femoral version showed clinically relevant differences. The bony hip morphology of professional dancers is similar to that of other athletes and age-matched controls, which is in contrast to the authors' clinical experience. We presume that the abnormal morphology we have seen at the clinic is only present in symptomatic dancers who require total hip arthroplasty (THA) and is not a general characteristic of all dancers. Further studies should compare the hip morphology of dancers undergoing THA with matched nondancers.

Increased Combined Anteversion Is an Independent Predictor of Ischiofemoral Impingement in the Setting of Borderline Dysplasia With Coxa Profunda

To investigate the differences in radiologic parameters between borderline dysplasia hips (BDDH)+/- coxa profunda and normal hips and to evaluate the correlations between these parameters and the prevalence of ischiofemoral impingement (IFI) in borderline dysplasia. The imaging of patients with BDDH (18° ≤ lateral center edge angle <25°) treated in our hospital from January 2018 to December 2019 was retrospective reviewed. These patients were divided into BDDH with coxa profunda (acetabular fossa touches the ilioischial line, pBDDH) and without coxa profunda (nBDDH) groups. The groups were compared with a control group with normal acetabular coverage. Neck-shaft angle, femoral offset, acetabular versions, acetabular coverage, ischial angle, femoral neck version, and combined anteversion were reviewed and analyzed using computed tomography imaging using one-way analysis of variance. There were 43 patients (36 female/7 male, 26.13 ± 4.96 years) in the pBDDH group, 22 patients (17 female/5 male, 28.60 ± 5.89 years) in the nBDDH group, and 23 patients (14 female/9 male, 27.67 ± 5.98 years) in the control group. The pBDDH group had increased femoral version, ischial angle, acetabular versions, and decreased ischiofemoral space (IFS)/quadratus femoris space (QFS) than the other 2 groups. The IFS/QFS correlated with neck-shaft angle, femoral offset, femoral neck version, acetabular versions, ischial angle, femoral neck-lesser trochanter angle, posterior acetabular coverage, and combined anteversion in patients with BDDH. Combined anteversion at the 3-o'clock level was an independent predictor of a decreased IFS (beta= -0.348, P= .007) and QFS (beta= -0.255, P= .01, R2= .550). Binary logistic regression demonstrated that patients with BDDH with large combined anteversion at the 3-o'clock level had a greater prevalence of IFI (odds ratio 1.148; P= .001, R2= .505). In patients with borderline dysplasia, the QFS/IFS significantly correlated with combined anteversion at the 3-o'clock level on clock face of acetabulum. BDDH with coxa profunda might have a greater prevalence of IFI because of large combined anteversion. III, retrospective comparative observation study.

1300 Version Abnormalities of the Femur and Acetabulum in Patients with Femoroacetabular Impingement: A Systematic Review

Abstract Aim This systematic review aims to understand the relationship between version abnormalities of the femur and acetabulum in patients with primary and secondary femoroacetabular impingement (FAI). Method A systematic review was conducted according to PRISMA guidelines. A computer-based search was performed using the EMBASE, MEDLINE, PubMed and Cochrane databases for articles relating to version and torsional abnormalities in FAI, Legg-Calve-Perthes disease (LCPD) and slipped capital femoral epiphysis (SCFE). The study was registered in the Open Science Framework. Two authors independently performed title/abstract and full text screening according to predetermined inclusion criteria. Results A total of 1206 articles were identified 55 articles, involving 10, 091 hips, met the inclusion criteria. All studies evaluating femoral/acetabular version in FAI reported ‘normal’ mean version values (10o to 25o). However, distribution analysis revealed that an estimated 31.4% and 51.3% of patients with FAI displayed abnormal acetabular and femoral version, respectively. Abnormal femoral version was reported in an estimated 74.5% of hips with LCPD, and abnormal acetabular version in an estimated 20%. Acetabular version was significantly lower in hips with SCFE compared to controls (Z=-3.26, P &amp;lt; 0.01). Conclusions Patients presenting with hip pain attributed to FAI are likely to display an abnormality in femoral or acetabular version. This highlights the importance of evaluating these parameters during assessment of these patients, in order to guide clinical decision making.

Asymmetrically increased femoral version with high prevalence of moderate and severe femoral anteversion in unilateral Legg-Calvé-Perthes disease.

PurposeTo determine and stratify femoral version in Legg-Calvé-Perthes disease (LCPD), and to compare the femoral version between the LCPD hip and the contralateral unaffected hip.MethodsWe performed a retrospective review of 45 patients with unilateral LCPD who had available CT scan through the hips and knees between January 2000 and June 2017. There were 34 (76%) male cases with a mean age of 14 years (sd 4.69). Two independent readers measured femoral version on the affected and the unaffected contralateral femur. Femoral version was classified as follows: severely decreased version (< 10°); moderately decreased (10° to 14°); normal femoral version range (15° to 20°); moderately increased (21° to 25°); and severely increased version (> 25°).ResultsLCPD hips had predominantly increased femoral version (38% severely increased anteversion, 24% moderately increased anteversion), while 51% of the contralateral unaffected hips had normal femoral version (p < 0.001). LCPD hips had higher mean femoral version than the contralateral, unaffected side (mean difference = 13o; 95% confidence iterval 10o to 16o; p < 0.001). As the version of the affected hip increased, so did the discrepancy between sides. No effect of sex on the LCPD femoral version was detected (p = 0.34).ConclusionThis study included a selected group of patients with unilateral LCPD and available CT scans obtained for surgical planning. The femoral version was asymmetric, with a high proportion of excessive anteversion observed at later stages of disease in the affected hips. Future studies will be necessary to determine the pathogenesis of increased femoral version associated with LCPD.Level of EvidenceLevel IV, retrospective study.

Short-term Outcomes of Concomitant Femoral Derotation Osteotomy and Hip Arthroscopy.

The goal of this study is to report the short-term outcomes of concomitant hip arthroscopy and femoral derotational osteotomy (FRO) to treat femoral malrotation and intra-articular pathology. Data were retrospectively reviewed for patients undergoing concomitant hip arthroscopy and FRO between March 2013 and January 2017. Patients were included if they had a minimum of 1 year of follow-up for modified Harris Hip Score (mHHS), Nonarthritic Hip Score (NAHS), Hip Outcome Score-Sports Specific Subscale (HOS-SSS), International Hip Outcome Tool (iHOT-12) score, 12-item Short Form Health Survey Physical component and Mental component (SF-12 P and SF-12 M, respectively) scores, Veterans RAND 12-item Health Survey Physical and Mental (VR-12 P and VR-12 M, respectively) scores, visual analog scale (VAS) score for pain, and patient satisfaction ratings. Rates for meeting the patient acceptable symptomatic state (PASS) and minimal clinically important difference (MCID) were also recorded. Nine hips were included, and mean follow-up was 36.9 months. Mean preoperative femoral version was 33.0°. Patients underwent 1 or more concomitant procedures, such as labral treatment, capsular plication, acetabuloplasty, or femoroplasty. At latest follow-up, significant improvement was seen for mHHS, NAHS, HOS-SSS, and VAS score. Additionally, rates of meeting the PASS for mHHS, iHOT-12 score, and HOS-SSS were 100%, 88.9%, and 55.6%, respectively. Rates of achieving MCID for mHHS and HOS-SSS were 77.8% and 66.7%, respectively. One hip required revision derotational osteotomy to treat overcorrection, and 3 hips underwent secondary surgery for hardware removal. Concomitant hip arthroscopy and FRO may yield improved outcomes for patients with concurrent intra-articular pathology and excessive femoral anteversion. Considering that no major complications were diagnosed, this procedure is also relatively safe. [Orthopedics. 2021;44(6):e739-e746.].

Is a periacetabular osteotomy as efficacious in retroversion as it is in dysplasia? : The role of femoral anteversion on outcome.

AimsPeriacetabular osteotomy (PAO) is an established treatment for acetabular dysplasia. It has also been proposed as a treatment for patients with acetabular retroversion. By reviewing a large cohort, we aimed to test whether outcome is equivalent for both types of morphology and identify factors that influenced outcome.MethodsA single-centre, retrospective cohort study was performed on patients with acetabular retroversion treated with PAO (n = 62 hips). Acetabular retroversion was diagnosed clinically and radiologically (presence of a crossover sign, posterior wall sign, lateral centre-edge angle (LCEA) between 20° and 35°). Outcomes were compared with a control group of patients undergoing PAO for dysplasia (LCEA < 20°; n = 86 hips). Femoral version was recorded. Patient-reported outcome measures (PROMs), complications, and reoperation rates were measured.ResultsThe mean Non-Arthritic Hip Score (NAHS) preoperatively was 58.6 (SD 16.1) for the dysplastic hips and 52.5 (SD 12.7) for the retroverted hips (p = 0.145). Postoperatively, mean NAHS was 83.0 (SD 16.9) and 76.7 (SD 17.9) for dysplastic and retroverted hips respectively (p = 0.041). Difference between pre- and postoperative NAHS was slightly lower in the retroverted hips (18.3 (SD 22.1)) compared to the dysplastic hips (25.2 (SD 15.2); p = 0.230). At mean 3.5 years’ follow-up (SD 1.9), one hip needed a revision PAO and no hips were converted to total hip arthroplasty (THA) in the retroversion group. In the control group, six hips (7.0%) were revised to THA. No differences in complications (p = 0.106) or in reoperation rate (p = 0.087) were seen. Negative predictors of outcome for patients undergoing surgery for retroversion were female sex, obesity, hypermobility, and severely decreased femoral anteversion.ConclusionA PAO is an effective surgical intervention for acetabular retroversion and produces similar improvements when used to treat dysplasia. Femoral version should be routinely assessed in these patients and when extremely low (< 0°), as an additional procedure to address this abnormality may be necessary. Females with signs of hypermobility should also be consulted of the likely guarded improvement.Cite this article: Bone Jt Open 2021;2(9):757–764.