Introduction and Aims: Ganglia are commonly seen during investigation of patients with wrist pain. Our aim was to determine the prevalence of ganglia in an asymptomatic population. Method: Following Institutional Ethical approval, Magnetic Resonance Imaging (MRI) was performed on the wrists of 103 asymptomatic volunteers. There were 67 males and 37 females, with an average age of 36, range 19–67 years. There were 52 right wrists and 51 left wrists. Using a 1.89 Tesla surface coil Magnetic Resonance Imager the following sequences were obtained: Coronal T 1, Proton Density, T 2 and Inversion Recovery sequences; Sagittal Inversion Recovery sequences; Axial T 1 and Inversion Recovery Sequences. The images were then evaluated independently by two Muskuloskeletal Radiologists and one Orthopaedic Surgeon. Results: Wrist Ganglia were identified in 53 out of 103 wrists. Wrist Ganglia were more prevalent in females than males, 58% compared to 48% respectively. The average long axis measurement was 7.5 mm (range 2.7–22.2), the average short axis measurement was 3.2 mm (range 1.6–10.1). Seventy percent of the Ganglia were found to originate from the volar capsule in the region of the interval between the Radio-Scapho-Capitate Ligament and the Long Radio-Lunate Ligament. Fourteen percent of the ganglia were dorsal and originated from the dorsal, distal fibres of the Scapho-Lunate Ligament. Two ganglia had surrounding soft tissue oedema and one had an associated intra-osseous component. Conclusion: The prevalence of asymptomatic wrist ganglia is high – 51%. Unlike previous surgical and pathological series, our study showed volar wrist ganglia are more common than dorsal wrist ganglia in the asymptomatic population. The vast majority of these asymptomatic ganglia do not show associated ligamentous disruption, soft tissue oedema or intra-osseous communication

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: Bone Joint J 2015;97-B:623–7.

Introduction: Femoroacetabular impingement (FAI) is an important cause of hip pain in young adults and a precursor to osteoarthritis. Morphological abnormality of either the acetabulum, proximal femur, or both, may result in FAI. The majority of patients however, have a cam deformity of the proximal femur. From a research perspective, FAI is an example of how subtle morphological abnormality results in a predictable pattern of cartilage damage, and thereby offers great potential as a model to study early degenerative disease and for clinical trials of joint preserving treatments. Accurate classification of the morphology of the hip is essential for this further study.

The aim of this study was to define normal, borderline, and abnormal parameters for the morphology of the proximal femur, in the context of the cam deformity, by studying asymptomatic individuals with normal clinical examination and no osteoarthritis from the general population.

Methods: 157 individuals (79 male, 78 female, mean age 46 years) with no previous history of hip problems were recruited. The participants were the spouses/partners of patients involved in a cohort study of osteoarthritis and FAI. All participants underwent clinical (interview, examination, and hip scores) and radiological assessment (standardised AP Pelvic and cross-table lateral radiographs of each hip). Radiographs were scored for the presence of osteoarthritis, and the morphology of the proximal femur was analysed. The alpha angle, anterior offset ratio, presence of a cam ‘bump’, synovial herniation pit were recorded in each hip.

Results: 21 subjects were excluded because they either had positive clinical features or radiological evidence of osteoarthritis (equivalent to a Kellgren and Lawrence grade of 2). From the remaining 136 subjects, with essentially ‘normal hips from the general population’, mean values for the alpha angle and anterior offset ratio were generated. Borderline and Abnormal values are suggested. Gender differences were noted with higher mean alpha angles and lower offset ratios occurring in men.

Discussion: Although it has limitations, standardised plain radiography remains the cheapest and most convenient way to screen an individual for the presence of a cam deformity. Despite the recent interest in FAI, our knowledge of what is normal in the general population, as assessed using appropriate radiographic techniques, is modest. The ranges provided by this study will facilitate the accurate classification of subjects with FAI, thereby providing guidance for surgeons treating such patients, and also enable the generation of refined cohorts for the study of the natural history of subtle morphological abnormalities of the hip, and for enrolment in clinical trials.

Aims. This study sought to establish the prevalence of the cross over sign (COS) and posterior wall sign (PWS) in relation to the anterior pelvic plane (APP) in an asymptomatic population through reliable and accurate 3D-CT based assessment. Materials and Methods. Data from pelvic CT scans of 100 asymptomatic subjects (200 hips) undertaken for conditions unrelated to disorders of the hip were available for analysis in this study. A previously established 3D analysis method was applied to assess the prevalence of the COS and PWS in relation to the APP. Results. Of the 200 included hips, 24% (48) presented a positive COS and 5.5% (11) presented a positive PWS. A combination of COS and PWS was observed in 1% (two) of all hips (1%). . Conclusion. The high incidence of acetabular retroversion, determined by the COS, shows that this anatomic configuration may not differ in frequency between asymptomatic individuals and patients with symptomatic femoroacetabular impingement (FAI). Patients presenting with hip pain and evidence of FAI should be subjected to strict diagnostic scrutiny and evaluated in the sum of their clinical and radiological presentation. In our cohort of asymptomatic adults, the COS showed a higher incidence than the PWS or a combined COS/PWS. Cite this article: Bone Joint J 2017;99-B:1584–9

Shoulder injury related to vaccine administration (SIRVA) is a prolonged episode of shoulder dysfunction that commences within 24 to 48 hours of a vaccination. Symptoms include a combination of shoulder pain, stiffness, and weakness. There has been a recent rapid increase in reported cases of SIRVA within the literature, particularly in adults, and is likely related to the mass vaccination programmes associated with COVID-19 and influenza. The pathophysiology is not certain, but placement of the vaccination in the subdeltoid bursa or other pericapsular tissue has been suggested to result in an inflammatory capsular process. It has been hypothesized that this is associated with a vaccine injection site that is “too high” and predisposes to the development of SIRVA. Nerve conduction studies are routinely normal, but further imaging can reveal deep-deltoid collections, rotator cuff tendinopathy and tears, or subacromial subdeltoid bursitis. However, all of these are common findings within a general asymptomatic population. Medicolegal claims in the UK, based on an incorrect injection site, are unlikely to meet the legal threshold to determine liability. Cite this article: Bone Joint J 2023;105-B(8):839–842

Femoro-acetabular impingement involves a deformity of the hip joint and is associated with hip osteoarthritis. Although 15% of the asymptomatic population exhibits a deformity, it is not clear who will develop symptoms. Current diagnostic imaging measures have either low specificity or low sensitivity and do not consider the dynamic nature of impingement during daily activities. The goal of this study is to determine stresses in the cartilage, subchondral bone and labrum of normal and impinging hips during activities such as walking and sitting down. Quantitative CT scans were obtained of a healthy Control and a participant with a symptomatic femoral cam deformity (‘Bump’). 3D models of the hip were created from automatic segmentation of CT scans. Cartilage layers were added so the articular surface was the mid-line of the joint. Finite element meshes were generated in each region. Bone elastic modulus was assigned element-by-element, calculated from CT intensity converted to bone mineral density using a calibration phantom. Cartilage was modelled as poroelastic, E=0.467 MPa, v=0.167, and permeability 3×10. -16. m. 4. /N s. The pelvis was fixed while rotations and contact forces from Bergmann et al. (2001) were applied to the femur over one load cycle for walking and sitting in a chair. All analyses were performed in FEBio. High shear stresses were seen near the acetabular cartilage-labrum junction in the Bump model, up to 0.12 MPa for walking and were much higher than in the Control. Patient-specific modelling can be used to assess contact and tissue stresses during different activities to better understand the risk of degeneration in individuals, especially for activities that involve high hip flexion. The high stresses at the cartilage labrum interface could explain so-called bucket-handle tears of the labrum

We performed a retrospective examination of the anteroposterior pelvic CT scout views of 419 randomly selected patients between April 2004 and August 2009 in order to determine the prevalence of cam-type femoroacetabular deformity in the asymptomatic population. The CT scans had all been undertaken for conditions unrelated to disorders of the hip. The frequency of cam-type femoroacetabular deformity was assessed by measuring the α-angle of each hip on the anteroposterior images. The α-angles were classified according to the Copenhagen Osteoarthritis Study. Among 215 male hips (108 patients) the mean α-angle was 59.12° (37.75° to 103.50°). Of these, a total of 30 hips (13.95%) were defined as pathological, 32 (14.88%) as borderline and 153 (71.16%) as normal. Among 540 female hips (272 patients) the mean α-angle was 45.47° (34.75° to 87.00°), with 30 hips (5.56%) defined as pathological, 33 (6.11%) as borderline and 477 (88.33%) as normal. It appears that the cam-type femoroacetabular deformity is not rare among the asymptomatic population. These anatomical abnormalities, as determined by an increased α-angle, appear to be twice as frequent in men as in women. Although an association between osteoarthritis and femoroacetabular impingement is believed to exist, a long-term epidemiological study is needed to determine the natural history of these anatomical abnormalities

Purpose. To determine if clinical outcomes are correlated with center of rotation (COR) in patients implanted with a viscoelastic total disc replacement (VTDR). Methods. Fifty patients with single-level, symptomatic lumbar DDD between L4 and S1 were enrolled in a clinical trial of a VTDR across three surgical centres. A comprehensive, independent review and statistical analysis of both clinical and radiographic outcomes was performed and analyzed for correlations. Data from preoperative through 2 years were available. The COR was calculated for the index levels and compared to data for an asymptomatic population. Each COR coordinate was classified as abnormal if outside of the 95% confidence interval for an asymptomatic population. Results. At most recent follow-up, 69% of the patients had achieved at least a 15 point Oswestry Disability Index (ODI) improvement. 76% of the patients achieved at least a 10 point improvement. At most recent follow-up, 78% of cases had a normal COR-X and 92% had a normal COR-Y. Results from three statistical tests show the association between COR-X and outcomes. 1) Based on latest available time point for each patient, the improvement in ODI score was significantly better for patients with a normal anterior-posterior (AP) coordinate of the COR (P=0.03). 2) Anterior COR corresponded with anterior placement of the device in the disc space, and patients were almost 7 times less likely to achieve at least a 15 point improvement in the ODI score if the COR was positioned too anteriorly. 3) This effect was also seen in the average AP coordinate of the COR for patients who achieved a 15 point ODI improvement. Conclusions. A viscoelastic TDR can restore a normal COR. This is the first study to show that restoration of a normal COR correlates with a significant and clinically relevant improvement in patient disability

Purpose. To determine if clinical outcomes are correlated with center of rotation (COR) in patients implanted with a viscoelastic total disc replacement (VTDR). Methods. Fifty patients with single-level, symptomatic lumbar DDD between L4 and S1 were enrolled in a clinical trial of a VTDR across three surgical centres. A comprehensive, independent review and statistical analysis of both clinical and radiographic outcomes was performed and analyzed for correlations. Data from preoperative through 2 years were available. The COR was calculated for the index levels and compared to data for an asymptomatic population. Each COR coordinate was classified as abnormal if outside of the 95% confidence interval for an asymptomatic population. Results. At most recent follow-up, 69% of the patients had achieved at least a 15 point Oswestry Disability Index (ODI) improvement. 76% of the patients achieved at least a 10 point improvement. At most recent follow-up, 78% of cases had a normal COR-X and 92% had a normal COR-Y. Results from three statistical tests show the association between COR-X and outcomes. 1) Based on latest available time point for each patient, the improvement in ODI score was significantly better for patients with a normal anterior-posterior (AP) coordinate of the COR (P=0.03). 2) Anterior COR corresponded with anterior placement of the device in the disc space, and patients were almost 7 times less likely to achieve at least a 15 point improvement in the ODI score if the COR was positioned too anteriorly. 3) This effect was also seen in the average AP coordinate of the COR for patients who achieved a 15 point ODI improvement. Conclusions. A viscoelastic TDR can restore a normal COR. This is the first study to show that restoration of a normal COR correlates with a significant and clinically relevant improvement in patient disability

Introduction: There are very few data on baropodometric semiology in hallux valgus. Based on the analysis of fore-foot cases, we will try to show if there are early baropodometric signs of perturbation of support by the first ray. Material: We compared clinical, radiological and baropodometric data from 105 feet (35 women, 18 men, average age: 55). The MT1/MT2 angle measured 1.26° to 22.02°, with an average of 11.94°, standard deviation 3.65. The MT1/MT5 angle was 15.04° to 39.56° with an average of 28.13°, standard deviation 4.76. Methods: We recorded angles and differences in the lengths of metatarsi on anteroposterior X-rays. A Novel platform and its Emed software (Munich, Germany) enabled to record ground forces. We divided into ten weight-bearings zones: rear and mid-foot, the five metatarsi, the hallux, the second toe and the lateral toes. For each zone, we studied the distribution of the integral force time (IFT) and the instant of the step when the greatest force and pressure occurred. We compared those three criteria with the MT1/MT2 angle and the type of functional complaint from the patient. Results: For the metatarsal zones, we identified four types of « baropodometric » populations depending on the radiological and clinical analysis. The asymptomatic population had maximal IFT on the medium metatarsi, and the instant of greatest simultaneous force and pressure was in the last quarter of the weight-bearing phase. The second population was the asymptomatic population with maximal IFT on the head of the first metatarsi, but the chronology of maximal force and pressure had no perturbation. The third type was a very symptomatic population with a higher IFT on MT1, for which the greatest ground force occurred very early compared with the other metatarsi (at about the middle of the weight-bearing phase). The fourth population had no systematic pattern for IFT or maximal ground forces phases. Discussion: The development of a hallux valgus leads to an increase in the load of the head of MT1 (increase in the IFT). Then, as the deformity worsens and the meta-tarsosesamoid dislocates, weight-bearing on the first ray occurs earlier, with the diaphysis of MT1 before leading to a total disorganisation of the chronological phases of the forefoot. Conclusion: Dynamic baropodometric study of the fore-foot can predict if a hallux valgus will worsen, and if our correction will remain stable

Femoroacetabular impingement (FAI) causes pain and chondrolabral damage via mechanical overload during movement of the hip. It is caused by many different types of pathoanatomy, including the cam ‘bump’, decreased head–neck offset, acetabular retroversion, global acetabular overcoverage, prominent anterior–inferior iliac spine, slipped capital femoral epiphysis, and the sequelae of childhood Perthes’ disease. Both evolutionary and developmental factors may cause FAI. Prevalence studies show that anatomic variations that cause FAI are common in the asymptomatic population. Young athletes may be predisposed to FAI because of the stress on the physis during development. Other factors, including the soft tissues, may also influence symptoms and chondrolabral damage. FAI and the resultant chondrolabral pathology are often treated arthroscopically. Although the results are favourable, morphologies can be complex, patient expectations are high and the surgery is challenging. The long-term outcomes of hip arthroscopy are still forthcoming and it is unknown if treatment of FAI will prevent arthrosis

Tapping the radial side of the wrist normally elicits a reflex contraction producing elbow flexion, wrist extension and wrist radial deviation. An abnormal response, consisting of finger flexion when performing this manoeuvre is known as the inverted radial (supinator) reflex (IRR). The significance of this reflex in asymptomatic subjects is unknown. To document the frequency of the IRR in an asymptomatic population and to identify any presymptomatic pathology in those subjects. The study group consisted of patients and staff at the senior author's institution. Patients were taken from clinics where the complaints were of lower limb symptoms. Subjects were excluded if they had any history of neck pain or stiffness or if they had any subjectively abnormal sensation. The radial reflex was elicited with a tendon hammer. Those subjects with an IRR were asked to attend for a MRI scan of the cervical spine to investigate for any abnormality. 47 subjects were studied. There were 8 subjects who displayed an IRR. In 4 subjects the IRR was unilateral and in 4 bilateral. Seven subjects consented to further investigation by MRI. The average age of these patients was 36 years. The MRI scans revealed normal appearances in 6 cases. There was no cord signal abnormality in any case. The IRR occurred with a frequency of 17% in the study group. There was no significant cervical pathology identified in these subjects. In young asymptomatic patients, the presence of an inverted radial reflex is of no diagnostic relevance

Purpose: Gait analysis has become an innovative approach to assess the biomechanical adaptations due to an ACL injury. However, interpreting the large amount of data collected often requires an expert. Therefore, there is a need to develop an automatic method capable to distinguish kinetic pattern of an ACL deficient patients from an asymptomatic population. Method: 26 ACL deficient patients and 30 asymptomatic participants took part in a treadmill gait analysis. 3D ground reaction forces (vertical, medio-lateral and anterior-posterior) were collected using the ADAL 3D treadmill. Features were extracted from the 3D ground reaction forces as a function of time and then classified by the nearest neighbour rule using a wavelet decomposition method. The classification method was tested on our data base of 56 participants. Results: The proposed classification method obtained an accuracy of 90%. The classification accuracy per class was higher for the ACL deficient group allowing classifying correctly 25 out of 26 ACL deficient patient. 25 out of the 30 asymptomatic participants were properly classified. Conclusion: This study shows that an automatic objective computer method could be used in a clinical setting to help diagnose an anterior cruciate ligament injury during a gait analysis evaluation. Future studies should apply this method on a larger database including data from patients with other musculoskeletal pathologies to help diagnose other injuries

To study the association between hip and ankle biomechanics during gait and moderate knee osteoarthritis (OA). Gait analysis was performed on a group of forty-four patients clinically diagnosed with moderate knee OA, and on a group of sixty asymptomatic subjects. Three-dimensional net joint angles and net joint reaction moments at the hip, knee and ankle joints were calculated. Peak values were extracted from the gait waveform patterns and compared between the two subject groups with Student’s t-tests. The peak hip extension moment, the peak hip adduction moment, the peak hip internal and external rotation moments, and the peak ankle dorsiflexion and plantarflexion moments were all reduced in the knee osteoarthritis population compared to the asymptomatic population. Differences in knee joint loading patterns with moderate knee osteoarthritis have been previously reported, but these data suggest that changes in the mechanical environment of all lower extremity joints are associated with early stages of knee osteoarthritis. Other studies have associated reduced peak hip adduction moments with reduced likelihood of OA progression. These data provide a rationale for hip abductor muscle strengthening as a means to lower knee joint loading

The June 2024 Shoulder & Elbow Roundup³⁶⁰ looks at: Reverse versus anatomical total shoulder replacement for osteoarthritis? A UK national picture; Acute rehabilitation following traumatic anterior shoulder dislocation (ARTISAN): pragmatic, multicentre, randomized controlled trial; acid for rotator cuff repair: a systematic review and meta-analysis of randomized controlled trials; Metal or ceramic humeral head total shoulder arthroplasty: an analysis of data from the National Joint Registry; Platelet-rich plasma has better results for long-term functional improvement and pain relief for lateral epicondylitis: a systematic review and meta-analysis of randomized controlled trials; Quantitative fatty infiltration and 3D muscle volume after nonoperative treatment of symptomatic rotator cuff tears: a prospective MRI study of 79 patients; Locking plates for non-osteoporotic proximal humeral fractures in the long term; A systematic review of the treatment of primary acromioclavicular joint osteoarthritis.

Background. Morton's neuroma is the enlargement of an interdigital nerve most commonly located between the third and fourth metatarsals. It is susceptible to entrapment and therefore is a common cause of disabling foot pain. Greek foot is a normal variant where the first metatarsal is shorter than the second metatarsal. To our knowledge there is currently no reported association between Greek foot and Morton's neuroma in the literature. Material and methods. Retrospective study of 184 patients. Two separate cohorts were recruited. Cohort (A): 100 randomly selected patients with no foot pain. Cohort (B): 84 patients with foot pain and Mortons's neuroma. The foot shape was determined by using a self-assessment tool and plain radiographs. Statistical analyses were performed using the Chi square test on the association between Greek foot and Morton's neuroma. A value of P = < 0.05 was considered statistically significant. Results. Our study shows a statistically significant association between Greek foot and Morton's neuroma with a prevalence of Greek foot in Cohort (A) of 20% (95% C.I.:12%–28%) and in Cohort (B) of 63% (95% C.I.:53%–73%). (P = 2.6 × 10. −9. ). Discussion. This study has shown a possible association between the presence of a Greek foot and the presence of Morton's neuroma. We can conclude that people with foot pain are more likely to have Greek foot than Egyptian foot and that the prevalence of Greek foot is higher in patients with Morton's neuroma than in the asymptomatic population. Although our study design has limitations and does not allow full statistical analysis, we do believe that the shown association between Greek foot and Morton's neuroma can help clinicians and other health care providers in establishing the diagnosis of Morton's neuroma in patients with a painful foot

Background: Many studies have examined magnetic resonance images (MRI) with a view to the anatomy and signaling properties of the intervertebral disc and adjacent tissues in asymptomatic populations. In this study we have examined MRIs of a discrete population of patients undergoing surgery for symptomatic disc herniations. Methods: Sixty patients (aged 23–66 years, mean 41.5±8.4) had sagittal T1 and T2- weighted turbo spin echo imaging of the lumbar spine prior to surgery. One disc was herniated at L2-3, 3 at L3-4, 22 at L4-5 and 31 at L5-S1; 3 patients had herniations at both L4-5 and L5-S1. The images were scored for disc narrowing and signal, degree of anterior and posterior bulging and herniation, and assessed for Modic I and II endplate changes and fatty degeneration within the vertebrae. These were carried out for each of 6 discs (T12-S1) for all patients (ie 360 discs and 720 endplates). Results: There were trends of increasing disc narrowing, disc bulging and fatty degeneration with increasing age in these patients. 83% of patients had disc bulging, 53% had endplate irregularities and 44% had fatty degeneration. There was a significant correlation between patient weight and fatty degeneration. 7.5% of vertebrae (in 22% of patients) demonstrated Modic I changes whilst Modic II changes were seen in 14% of vertebrae (40% of patients). This is considerably higher than the incidence reported in asymptomatic individuals where Modic I changes were seen in 0.7% of vertebrae (3% of individuals) and Modic II changes in 1.9% of vertebrae (10% of individuals). Conclusion: There is a higher incidence of Modic I and II changes in disc herniation patients than in asymptomatic individuals

INTRODUCTION:. Acetabular retroversion has been implicated as a risk factor for the development of early hip osteoarthritis. In clinical practice standard osseous signs such as the cross-over sign (COS) and the posterior wall sign (PWS) are widely used to establish the diagnosis of acetabular retroversion on plain radiographs. Despite standardized radiological evaluation protocols, an increased pelvic tilt can lead to a misdiagnosis of acetabular retroversion in AP radiographs and 2D MR or CT scans. Previous studies have shown that the elimination of observer bias using a standardized methodology based on 3D-CT models and the anterior pelvic plane (APP) for the assessment of COS and PWS results in greater diagnostic accuracy. Using this method a prevalence of 28% for COS and 24% for PWS has been found in a cohort of patients with symptoms indicative of FAI, however the prevalence of both signs in asymptomatic adults remains unknown. This study therefore sought to establish the prevalence of the COS and PWS in relation to the APP in an asymptomatic population using a reliable and accurate 3 D-CT based assessment. METHODS:. A large pool of consecutive CT scans of the pelvis undertaken in our department for conditions unrelated to disorders of the hip was available for analysis. Scans in subjects with a Harris hip score of less than 90 points were excluded leaving a sample of 100 asymptomatic subjects (200 hips) for this study. A previously established 3D analysis method designed to eliminate errors resulting from variations in the position and orientation of the pelvis during CT imaging was applied to determine in order to assess the prevalence of the COS and PWS in relation to the APP. Here, the acetabuli were defined as retroverted if either the COS, PWS or both were positive. RESULTS:. From the total of 200 hips a positive COS was identified in 24% (48/200) and a positive PWS was detected in 6.5% (13/200) relative to the APP using the CT data. A. In male adults a COS was observed in 25.4% (29/114) and a PWS in 10.5% (12/114). In female adults a COS were observed in 22.1% (19/86) and a PWS in 1.2% (1/86). DISCUSSION:. The high incidence of acetabular retroversion observed using an accurate 3D-CT based methodology shows that this anatomic configuration might not differ in frequency between asymptomatic individuals and patients with symptomatic FAI. Patients presenting with hip pain and evidence of FAI should therefore be subjected to strict diagnostic scrutiny, as the presence of a COS and/or PWS shows a poor correlation with the presence of symptomatic disease. In our collective of asymptomatic adults the COS showed a higher incidence than the PWS. Additionally a deficiency of the posterior acetabular wall was rare in asymptomatic adults compared to FAI patients. Therefore, the question whether an abnormal acetabular version does indeed lead to the development of osteoarthritis in all patients warrants further study. Although an association between osteoarthritis and femuro-acetabular impingement is believed to exist, long-term epidemiological studies are needed to establish the natural history of these anatomical configurations

Introduction. Acetabular dysplasia cause hip joint osteoarthritis(OA) by change hip mechanism. However, to our best knowledge, no studies have been published using prospectively collected data from asymptomatic young age volunteers, precise radiographic method. The purpose of this study is to evaluate the prevalence of hip dysplasia in asymptomatic Korean population as one of the most important risk factor of hip OA. Materials & Methods. From December 2014 to March 2015, we investigated prospectively collected retrospectively reviewed data of 200 asymptomatic volunteers 400 hips in age between 18 and 50 years recruited from our institution. Pelvic radiographs were taken and all radiographs were reviewed by 2 experienced orthopedic surgeons. Lateral center-edge angle(LCEA), Sharp angle, Tonnis angle and acetabular width-depth ratio were measured. We analyzed the statistical differences of these values between sex by Mann-Whitney U test and independent t-test. Pearson's correlation coefficient was used to measure the relationship between dysplasia parameters. Results. On the Pelvic AP view, 60 of the 400 hips (15%) were dysplastic hip as LCEA <20°. In 146 male hips, 17 hips (11.6%) were LCEA <20°. In 254 female hips, 43 hips(16.9%) were LCEA <20°. There was no strong correlation of LCEA with other measurements. Conclusion. There are large number of asymptomatic dysplastic hips in Asian population compared previously investigated