We report on gender-specific reference intervals
of the
Aims. Asphericity of the femoral head-neck junction is common in cam-type
femoroacetabular impingement (FAI) and usually quantified using
the
The radiological evaluation of the anterolateral femoral head is an essential tool for the assessment of the cam type of femoroacetabular impingement. CT, MRI and frog lateral plain radiographs have all been suggested as imaging options for this type of lesion. The
Objectives. The purpose of this study was to investigate whether the femoral
head–neck contour, characterised by the
Objectives. The spinopelvic relationship (including pelvic incidence) has been shown to influence pelvic orientation, but its potential association with femoroacetabular impingement has not been thoroughly explored. The purpose of this study was to prove the hypothesis that decreasing pelvic incidence is associated with increased risk of cam morphology. Methods. Two matching cohorts were created from a collection of cadaveric specimens with known pelvic incidences: 50 subjects with the highest pelvic incidence (all subjects > 60°) and 50 subjects with the lowest pelvic incidence (all subjects < 35°). Femoral version, acetabular version, and
Femoroacetabular impingement is a cause of hip pain in adults and is potentially a precursor of osteoarthritis. Our aim in this study was to determine the prevalence of bilateral deformity in patients with symptomatic cam-type femoroacetabular impingement as well as the presence of associated acetabular abnormalities and hip pain. We included all patients aged 55 years or less seen by the senior author for hip pain, with at least one anteroposterior and lateral pelvic radiograph available. All patients with dysplasia and/or arthritis were excluded. A total of 113 patients with a symptomatic cam-impingement deformity of at least one hip was evaluated. There were 82 men and 31 women with a mean age of 37.9 years (16 to 55). Bilateral cam-type deformity was present in 88 patients (77.8%) while only 23 of those (26.1%) had bilateral hip pain. Painful hips had a statistically significant higher mean
Objectives. The purpose of this study was to evaluate the existing literature from 2005 to 2016 reporting on the efficacy of surgical management of patients with femoroacetabular impingement (FAI) secondary to slipped capital femoral epiphysis (SCFE). Methods. The electronic databases MEDLINE, EMBASE, and PubMed were searched and screened in duplicate. Data such as patient demographics, surgical technique, surgical outcomes and complications were retrieved from eligible studies. Results. Fifteen eligible level IV studies were included in this review comprising 261 patients (266 hips). Treatment groups included arthroscopic osteochondroplasty, surgical hip dislocation, and traditional open osteotomy. The mean
Aims. Recently, there has been considerable interest in quantifying
the associations between bony abnormalities around and in the hip
joint and osteoarthritis (OA). Our aim was to investigate the relationships
between acetabular undercoverage, acetabular overcoverage, and femoroacetabular
impingement (FAI) with OA of the hip, which currently remain controversial. . Materials and Methods. A total of 545 cadaveric skeletons (1090 hips) from the Hamann-Todd
osteological collection were obtained. Femoral head volume (FHV),
acetabular volume (AV), the FHV/AV ratio, acetabular version, alpha
angle and anterior femoral neck offset (AFNO) were measured. A validated
grading system was used to quantify OA of the hip as minimal, moderate,
or severe. Multiple linear and multinomial logistic regression were
used to determine the factors that correlated independently with
the FHV, AV, and the FHV/AV ratio. . Results. Female cadavers had smaller FHVs (standardised beta -0.382, p
<
0.001), and AVs (standardised beta -0.351, p <
0.001), compared
with male patients, although the FHV/AV ratio was unchanged. Every
1° increase in
Objectives. The purpose of this study was to compare the thickness of the hip capsule in patients with surgical hip disease, either with cam-femoroacetabular impingement (FAI) or non-FAI hip pathology, with that of asymptomatic control hips. Methods. A total of 56 hips in 55 patients underwent a 3Tesla MRI of the hip. These included 40 patients with 41 hips with arthroscopically proven hip disease (16 with cam-FAI; nine men, seven women; mean age 39 years, 22 to 58) and 25 with non-FAI chondrolabral pathology (four men, 21 women; mean age 40 years, 18 to 63) as well as 15 asymptomatic volunteers, whose hips served as controls (ten men, five women; mean age 62 years, 33 to 77). The maximal capsule thickness was measured anteriorly and superiorly, and compared within and between the three groups with a gender subanalysis using student’s t-test. The correlation between
Aims. What represents clinically significant acetabular undercoverage
in patients with symptomatic cam-type femoroacetabular impingement
(FAI) remains controversial. The aim of this study was to examine
the influence of the degree of acetabular coverage on the functional
outcome of patients treated arthroscopically for cam-type FAI. Patients and Methods. Between October 2005 and June 2016, 88 patients (97 hips) underwent
arthroscopic cam resection and concomitant labral debridement and/or
refixation. There were 57 male and 31 female patients with a mean
age of 31.0 years (17.0 to 48.5) and a mean body mass index (BMI)
of 25.4 kg/m. 2. (18.9 to 34.9). We used the Hip2Norm, an
object-oriented-platform program, to perform 3D analysis of hip
joint morphology using 2D anteroposterior pelvic radiographs. The lateral
centre-edge angle, anterior coverage, posterior coverage, total
femoral coverage, and
Aims. The purpose of this study was to evaluate spinopelvic mechanics from standing and sitting positions in subjects with and without femoroacetabular impingement (FAI). We hypothesize that FAI patients will experience less flexion at the lumbar spine and more flexion at the hip whilst changing from standing to sitting positions than subjects without FAI. This increase in hip flexion may contribute to symptomatology in FAI. Patients and Methods. Male subjects were prospectively enrolled to the study (n = 20). Mean age was 31 years old (22 to 41). All underwent clinical examination, plain radiographs, and dynamic imaging using EOS. Subjects were categorized into three groups: non-FAI (no radiographic or clinical FAI or pain), asymptomatic FAI (radiographic and clinical FAI but no pain), and symptomatic FAI (patients with both pain and radiographic FAI). FAI was defined as internal rotation less than 15° and
Aims. The aim of this study was to examine the real time in
vivo kinematics of the hip in patients with cam-type femoroacetabular
impingement (FAI). Patients and Methods. A total of 50 patients (83 hips) underwent 4D dynamic CT scanning
of the hip, producing real time osseous models of the pelvis and
femur being moved through flexion, adduction, and internal rotation.
The location and size of the cam deformity and its relationship
to the angle of flexion of the hip and pelvic tilt, and the position
of impingement were recorded. Results. In these patients with cam-type FAI, there was significant correlation
between the
Aims. The aims of this study were to review the surgical technique for a combined femoral head reduction osteotomy (FHRO) and periacetabular osteotomy (PAO), and to report the short-term clinical and radiological results of a combined FHRO/PAO for the treatment of selected severe femoral head deformities. Patients and Methods. Between 2011 and 2016, six female patients were treated with a combined FHRO and PAO. The mean patient age was 13.6 years (12.6 to 15.7). Clinical data, including patient demographics and patient-reported outcome scores, were collected prospectively. Radiologicalally, hip morphology was assessed evaluating the Tönnis angle, the lateral centre to edge angle, the medial offset distance, the extrusion index, and the
Aims. This study analysed the clinical and radiological outcome of
anatomical reduction of a moderate or severe stable slipped capital
femoral epiphysis (SCFE) treated by subcapital osteotomy (a modified
Dunn osteotomy) through the surgical approach described by Ganz. . Patients and Methods. We prospectively studied 31 patients (32 hips; 16 females and
five males; mean age 14.3 years) with SCFE. On the Southwick classification,
ten were of moderate severity (head-shaft angle >
30° to 60°) and
22 were severe (head-shaft angle >
60°). Each underwent open reduction
and internal fixation using an intracapsular osteotomy through the
physeal growth plate after safe surgical hip dislocation. Unlike
the conventional procedure, 25 hips did not need an osteotomy of
the apophysis of the great trochanter and were managed using an
extended retinacular posterior flap. . Results. Clinical outcome was assessed using the range of movement and
the Harris Hip (HHS), Western Ontario and McMaster Universities
Osteoarthritis (WOMAC), and Merle d’Aubigné scores, while radiological
measurements included slip and
Aims. Acetabular dysplasia is frequently associated with intra-articular
pathology such as labral tears, but whether labral tears should
be treated at the time of periacetabular osteotomy (PAO) remains
controversial. The purpose of this study was to compare the clinical
outcomes and radiographic corrections of PAO for acetabular dysplasia
between patients with and without labral tears pre-operatively. Patients and Methods. We retrospectively reviewed 70 hips in 67 patients with acetabular
dysplasia who underwent PAO. Of 47 hips (45 patients) with labral
tears pre-operatively, 27 (25 patients) underwent PAO alone, and
were classified as the labral tear alone (LT) group, and 20 (20
patients) underwent combined PAO and osteochondroplasty, and were
classified as the labral tear osteochondroplasty (LTO) group. The
non-labral tear (NLT) group included 23 hips in 22 patients. Results. There were no significant differences between groups for post-operative
Harris hip scores, degree of progression of osteoarthritis or rate
of reoperation. The pre-operative
The cam-type deformity in femoroacetabular impingement
is a 3D deformity. Single measurements using radiographs, CT or
MRI may not provide a true estimate of the magnitude of the deformity.
We performed an analysis of the size and location of measurements
of the
Periacetabular osteotomy (PAO) is the preferred treatment for symptomatic acetabular dysplasia in adolescents and young adults. There remains a lack of consensus regarding whether intra-articular procedures such as labral repair or improvement of femoral offset should be performed at the time of PAO or addressed subsequent to PAO if symptoms warrant. The purpose was to determine the rate of subsequent hip arthroscopy (HA) in a contemporary cohort of patients, who underwent PAO in isolation without any intra-articular procedures. From June 2012 to March 2022, 349 rectus-sparing PAOs were performed and followed for a minimum of one year (mean 6.2 years (1 to 11)). The mean age was 24 years (14 to 46) and 88.8% were female (n = 310). Patients were evaluated at final follow-up for patient-reported outcome measures (PROMs). Clinical records were reviewed for complications or subsequent surgery. Radiographs were reviewed for the following acetabular parameters: lateral centre-edge angle, anterior centre-edge angle, acetabular index, and the alpha-angle (AA). Patients were cross-referenced from the two largest hospital systems in our area to determine if subsequent HA was performed. Descriptive statistics were used to analyze risk factors for HA.Aims
Methods
Early detection of developmental dysplasia of the hip (DDH) is associated with improved outcomes of conservative treatment. Therefore, we aimed to evaluate a novel screening programme that included both the primary risk factors of breech presentation and family history, and the secondary risk factors of oligohydramnios and foot deformities. A five-year prospective registry study investigating every live birth in the study’s catchment area (n = 27,731), all of whom underwent screening for risk factors and examination at the newborn and six- to eight-week neonatal examination and review. DDH was diagnosed using ultrasonography and the Graf classification system, defined as grade IIb or above or rapidly regressing IIa disease (≥4o at four weeks follow-up). Multivariate odds ratios were calculated to establish significant association, and risk differences were calculated to provide quantifiable risk increase with DDH, positive predictive value was used as a measure of predictive efficacy. The cost-effectiveness of using these risk factors to predict DDH was evaluated using NHS tariffs (January 2021).Aims
Methods
The April 2023 Children’s orthopaedics Roundup360 looks at: CT scan of the ipsilateral femoral neck in paediatric shaft fractures; Meniscal injuries in skeletally immature children with tibial eminence fractures: a systematic literature review; Post-maturity progression in adolescent idiopathic scoliosis curves of 40° to 50°; Prospective, randomized Ponseti treatment for clubfoot: orthopaedic surgeons versus physical therapists; FIFA 11+ Kids: challenges in implementing a prevention programme; The management of developmental dysplasia of the hip in children aged under three months: a consensus study from the British Society for Children's Orthopaedic Surgery; Early investigation and bracing in developmental dysplasia of the hip impacts maternal wellbeing and breastfeeding; Hip arthrodesis in children: a review of 26 cases with a mean of 20 years’ follow-up
To evaluate how abnormal proximal femoral anatomy affects different femoral version measurements in young patients with hip pain. First, femoral version was measured in 50 hips of symptomatic consecutively selected patients with hip pain (mean age 20 years (SD 6), 60% (n = 25) females) on preoperative CT scans using different measurement methods: Lee et al, Reikerås et al, Tomczak et al, and Murphy et al. Neck-shaft angle (NSA) and α angle were measured on coronal and radial CT images. Second, CT scans from three patients with femoral retroversion, normal femoral version, and anteversion were used to create 3D femur models, which were manipulated to generate models with different NSAs and different cam lesions, resulting in eight models per patient. Femoral version measurements were repeated on manipulated femora.Aims
Methods
The aim of this study was to investigate the agreement in interpretation of the quality of the paediatric hip ultrasound examination, the reliability of geometric and morphological assessment, and the relationship between these measurements. Four investigators evaluated 60 hip ultrasounds and assessed their quality based the standard plane of Graf et al. They measured geometric parameters, described the morphology of the hip, and assigned the Graf grade of dysplasia. They analyzed one self-selected image and one randomly selected image from the ultrasound series, and repeated the process four weeks later. The intra- and interobserver agreement, and correlations between various parameters were analyzed.Aims
Methods
Studies of infant hip development to date have been limited by considering only the changes in appearance of a single ultrasound slice (Graf’s standard plane). We used 3D ultrasound (3DUS) to establish maturation curves of normal infant hip development, quantifying variation by age, sex, side, and anteroposterior location in the hip. We analyzed 3DUS scans of 519 infants (mean age 64 days (6 to 111 days)) presenting at a tertiary children’s hospital for suspicion of developmental dysplasia of the hip (DDH). Hips that did not require ultrasound follow-up or treatment were classified as ‘typically developing’. We calculated traditional DDH indices like α angle (αSP), femoral head coverage (FHCSP), and several novel indices from 3DUS like the acetabular contact angle (ACA) and osculating circle radius (OCR) using custom software.Aims
Methods
The effect of pelvic tilt (PT) and sagittal balance in hips with pincer-type femoroacetabular impingement (FAI) with acetabular retroversion (AR) is controversial. It is unclear if patients with AR have a rotational abnormality of the iliac wing. Therefore, we asked: are parameters for sagittal balance, and is rotation of the iliac wing, different in patients with AR compared to a control group?; and is there a correlation between iliac rotation and acetabular version? A retrospective, review board-approved, controlled study was performed including 120 hips in 86 consecutive patients with symptomatic FAI or hip dysplasia. Pelvic CT scans were reviewed to calculate parameters for sagittal balance (pelvic incidence (PI), PT, and sacral slope), anterior pelvic plane angle, pelvic inclination, and external rotation of the iliac wing and were compared to a control group (48 hips). The 120 hips were allocated to the following groups: AR (41 hips), hip dysplasia (47 hips) and cam FAI with normal acetabular morphology (32 hips). Subgroups of total AR (15 hips) and high acetabular anteversion (20 hips) were analyzed. Statistical analysis was performed using analysis of variance with Bonferroni correction.Aims
Methods
Between May 1992 and April 1997, there were 20 452 births in the Blackburn District. In the same period 1107 infants with hip ‘at-risk’ factors were screened prospectively by ultrasound. We recorded the presence of dislocation and dysplasia detected under the age of six months using Graf’s
The prevalence of combined abnormalities of femoral torsion (FT) and tibial torsion (TT) is unknown in patients with femoroacetabular impingement (FAI) and hip dysplasia. This study aimed to determine the prevalence of combined abnormalities of FT and TT, and which subgroups are associated with combined abnormalities of FT and TT. We retrospectively evaluated symptomatic patients with FAI or hip dysplasia with CT scans performed between September 2011 and September 2016. A total of 261 hips (174 patients) had a measurement of FT and TT. Their mean age was 31 years (SD 9), and 63% were female (165 hips). Patients were compared to an asymptomatic control group (48 hips, 27 patients) who had CT scans including femur and tibia available for analysis, which had been acquired for nonorthopaedic reasons. Comparisons were conducted using analysis of variance with Bonferroni correction.Aims
Methods
Femoroacetabular cam impingement is thought to be a cause of premature osteoarthritis of the hip. The presence of cam malformation was determined in 2803 standardised anteroposterior (AP) pelvic radiographs from the Copenhagen Osteoarthritis Study by measuring the
This paper aims to review the evidence for patient-related factors associated with less favourable outcomes following hip arthroscopy. Literature reporting on preoperative patient-related risk factors and outcomes following hip arthroscopy were systematically identified from a computer-assisted literature search of Pubmed (Medline), Embase, and Cochrane Library using Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and a scoping review.Aims
Methods
The modified Dunn procedure has the potential to restore the anatomy in hips with severe slipped capital femoral epiphyses (SCFE). However, there is a risk of developing avascular necrosis of the femoral head (AVN). In this paper, we report on clinical outcome, radiological outcome, AVN rate and complications, and the cumulative survivorship at long-term follow-up in patients undergoing the modified Dunn procedure for severe SCFE. We performed a retrospective analysis involving 46 hips in 46 patients treated with a modified Dunn procedure for severe SCFE (slip angle > 60°) between 1999 and 2016. At nine-year-follow-up, 40 hips were available for clinical and radiological examination. Mean preoperative age was 13 years, and 14 hips (30%) presented with unstable slips. Mean preoperative slip angle was 64°. Kaplan–Meier survivorship was calculated.Aims
Patients and Methods
Abnormal femoral torsion (FT) is increasingly recognized as an additional cause for femoroacetabular impingement (FAI). It is unknown if in-toeing of the foot is a specific diagnostic sign for increased FT in patients with symptomatic FAI. The aims of this study were to determine: 1) the prevalence and diagnostic accuracy of in-toeing to detect increased FT; 2) if foot progression angle (FPA) and tibial torsion (TT) are different among patients with abnormal FT; and 3) if FPA correlates with FT. A retrospective, institutional review board (IRB)-approved, controlled study of 85 symptomatic patients (148 hips) with FAI or hip dysplasia was performed in the gait laboratory. All patients had a measurement of FT (pelvic CT scan), TT (CT scan), and FPA (optical motion capture system). We allocated all patients to three groups with decreased FT (< 10°, 37 hips), increased FT (> 25°, 61 hips), and normal FT (10° to 25°, 50 hips). Cluster analysis was performed.Aims
Patients and Methods
The aim of this study was to identify the association between
asymmetrical skin creases of the thigh, buttock or inguinal region
and pathological developmental dysplasia of the hip (DDH). Between 1 January 1996 and 31 December 2016, all patients referred
to our unit from primary or secondary care with risk factors for
DDH were assessed in a “one stop” clinic. All had clinical and sonographic
assessment by the senior author (RWP) with the results being recorded
prospectively. The inclusion criteria for this study were babies and
children referred with asymmetrical skin creases. Those with a neurological
cause of DDH were excluded. The positive predictive value (PPV)
for pathological DDH was calculated.Aims
Patients and Methods
Femoroacetabular impingement (FAI) has been highlighted and well
documented primarily in Western countries and there are few large
studies focused on FAI-related morphological assessment in Asian
patients. We chose to investigate this subject. We assessed the morphology of the hip and the prevalence of radiographic
FAI in Japanese patients by measuring predictors of FAI. We reviewed
a total of 1178 hips in 695 men and 483 women with a mean age of
58.2 years (20 to 89) using CT images that had been obtained for
reasons unrelated to symptoms from the hip. We measured the lateral
centre edge angle, acetabular index, crossover sign, alpha angle
and anterior femoral head-neck offset ratio.Aims
Patients and Methods
The aim of this study was to review the value of accepting referrals for children with ‘clicky hips’ in a selective screening programme for hip dysplasia. A single-centre prospective database of all referrals to the hip clinic was examined to identify indication for referrals, diagnosis, and treatment. All patients referred received a standardized ultrasound scan and clinical examination by an orthopaedic consultant.Aims
Patients and Methods
The hip’s capsular ligaments passively restrain extreme range of movement (ROM) by wrapping around the native femoral head/neck. We determined the effect of hip resurfacing arthroplasty (HRA), dual-mobility total hip arthroplasty (DM-THA), conventional THA, and surgical approach on ligament function. Eight paired cadaveric hip joints were skeletonized but retained the hip capsule. Capsular ROM restraint during controlled internal rotation (IR) and external rotation (ER) was measured before and after HRA, DM-THA, and conventional THA, with a posterior (right hips) and anterior capsulotomy (left hips).Aims
Materials and Methods
The significance of the ‘clicky hip’ in neonatal and infant examination
remains controversial with recent conflicting papers reigniting
the debate. We aimed to quantify rates of developmental dysplasia
of the hip (DDH) in babies referred with ‘clicky hips’ to our dedicated
DDH clinic. A three-year prospective cohort study was undertaken between
2014 and 2016 assessing the diagnosis and treatment outcomes of
all children referred specifically with ‘clicky hips’ as the primary
reason for referral to our dedicated DDH clinic. Depending on their
age, they were all imaged with either ultrasound scan or radiographs.Aims
Patients and Methods
The purpose of this study was to determine patient-reported
outcomes of patients with mild to moderate developmental dysplasia
of the hip (DDH) and femoroacetabular impingement (FAI) undergoing
arthroscopy of the hip in the treatment of chondrolabral pathology.
A total of 28 patients with a centre-edge angle between 15° and
19° were identified from an institutional database. Their mean age
was 34 years (18 to 53), with 12 female and 16 male patients. All
underwent labral treatment and concomitant correction of FAI. There
were nine reoperations, with two patients requiring revision arthroscopy,
two requiring periacetabular osteotomy and five needing total hip arthroplasty. Patients who required further major surgery were more likely
to be older, male, and to have more severe DDH with a larger alpha
angle and decreased joint space. At a mean follow-up of 42 months (24 to 89), the mean modified
Harris hip score improved from 59 (20 to 98) to 82 (45 to 100; p
<
0.001). The mean Western Ontario and McMaster Universities
Osteoarthritis Index score improved from 30 (1 to 61) to 16 (0 to
43; p <
0.001). Median patient satisfaction was 9.0/10 (1 to
10). Patients reported excellent improvement in function following
arthroscopy of the hip. This study shows that with proper patient selection, arthroscopy
of the hip can be successful in the young patient with mild to moderate
DDH and FAI. Cite this article:
The aim of this prospective cohort study was to evaluate the
effectiveness of the neonatal hip instability screening programme. The study involved a four-year observational assessment of a
neonatal hip screening programme. All newborns were examined using
the Barlow or Ortolani manoeuvre within 72 hours of birth; those
with positive findings were referred to a ‘one-stop’ screening clinic
for clinical and sonographic assessment of the hip. The results
were compared with previous published studies from this unit.Aims
Patients and Methods
Despite the presence of screening programmes, infants continue
to present with late developmental dysplasia of the hip (DDH), the
impact of which is significant. The aim of this study was to assess
infants with late presenting dislocation of the hip despite universal
clinical neonatal and selective ultrasound screening. Between 01 January 1997 to 31 December 2011, a prospective, longitudinal
study was undertaken of a cohort of 64 670 live births. Late presenting
dislocation was defined as presentation after three months of age.
Diagnosis was confirmed by ultrasound and plain radiography. Patient
demographics, referral type, reason for referral, risk factors (breech
presentation/strong family history) and clinical and radiological
findings were recorded.Aims
Patients and Methods
Acetabular labral tears and associated intra-articular
pathology of the hip have been recognised as a source of symptoms.
However, it is now appreciated that there is a relatively high prevalence
of asymptomatic labral tears. In this study, 70 young asymptomatic
adult volunteers with a mean age of 26 years (19 to 41) were recruited
and underwent three tesla non-arthrographic MR scans. There were
47 women (67.1%) and 23 men (32.9%). Labral tears were found in 27 volunteers (38.6%); these were
an isolated finding in 16 (22.9%) and were associated with other
intra-articular pathology in the remaining 11 (15.7%) volunteers.
Furthermore, five (7.1%) had intra-articular pathology without an
associated labral tear. Given the high prevalence of labral pathology in the asymptomatic
population, it is important to confirm that a patient's symptoms
are due to the demonstrated abnormalities when considering surgery. Cite this article:
The December 2014 Hip &
Pelvis Roundup360 looks at: Sports and total hips; topical tranexamic acid and blood conservation in hip replacement; blind spots and biases in hip research; no recurrence in cam lesions at two years; to drain or not to drain?; sonication and diagnosis of implant associated infection; and biomarkers and periprosthetic infection
To confirm whether developmental dysplasia of
the hip has a risk of hip impingement, we analysed maximum ranges
of movement to the point of bony impingement, and impingement location
using three-dimensional (3D) surface models of the pelvis and femur
in combination with 3D morphology of the hip joint using computer-assisted methods.
Results of computed tomography were examined for 52 hip joints with
DDH and 73 normal healthy hip joints. DDH shows larger maximum extension
(p = 0.001) and internal rotation at 90° flexion (p <
0.001).
Similar maximum flexion (p = 0.835) and external rotation (p = 0.713)
were observed between groups, while high rates of extra-articular
impingement were noticed in these directions in DDH (p <
0.001).
Smaller cranial acetabular anteversion (p = 0.048), centre-edge
angles (p <
0.001), a circumferentially shallower acetabulum,
larger femoral neck anteversion (p <
0.001), and larger alpha
angle were identified in DDH. Risk of anterior impingement in retroverted
DDH hips is similar to that in retroverted normal hips in excessive
adduction but minimal in less adduction. These findings might be
borne in mind when considering the possibility of extra-articular
posterior impingement in DDH being a source of pain, particularly
for patients with a highly anteverted femoral neck. Cite this article: