Flexion-adduction-internal Rotation Research Articles

Review of femoroacetabular impingement syndrome

Abstract Femoroacetabular impingement syndrome (FAIS) is a common condition of the hip that can cause significant damage to the joint, leading to degeneration and osteoarthritis. FAIS constitutes an abnormal and dynamic contact between the femoral head–neck junction and the acetabular rim, resulting from altered bone morphology at one or both sites. Repetitive trauma at the site of impingement generates progressive damage to the acetabular labrum, chondrolabral junction, and articular cartilage. Proper diagnosis based on patient symptoms, specific clinical signs, and imaging findings will guide treatment and ultimately allow preservation of the native hip joint. Common symptoms in patients with FAIS include pain, clicking, catching, buckling, stiffness, giving way, and a limited range of motion of the hip. Specific clinical maneuvers can aid diagnosis, such as flexion adduction internal rotation and flexion abduction external rotation tests. Imaging diagnosis includes orthogonal hip and pelvis X-ray views, as well as magnetic resonance imaging/magnetic resonance arthrogram imaging. Initial treatment of FAIS can be conservative and include physical therapy, intra-articular injections, and activity modification. Currently, the preferred surgical management consists of hip arthroscopy, which aims to correct bony abnormalities, repair or reconstruct labral lesions and address other intra-articular and extra-articular derangements as needed.

Relationship Between Hip and Groin Pain and Hip Range of Motion in Amateur Soccer and Australian Rules Football Players

Background: The relationship between hip/groin pain and hip range of motion (ROM) is unclear. Purpose: To explore the relationship between hip/groin pain and hip joint ROM and examine the influence of sex and cam morphology on this relationship. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Included were 184 amateur soccer and Australian Rules football players (276 hips; 20% women; median age, 26 years; interquartile range, 24-30 years) with hip/groin pain >6 months and a positive flexion-adduction-internal-rotation (FADIR) test, and 50 matched asymptomatic control players (98 hips; 28% women, median age, 26 years; interquartile range, 23-31 years). Hip ROM measures were flexion, internal and external rotation at 90° of hip flexion, total rotation (internal and external), and bent-knee fall out (BKFO). Cam morphology was determined from anteroposterior pelvis or 45° Dunn radiographs, defined by an alpha angle ≥60°. Linear regression models with generalized estimating equations were used to examine the relationship between group (symptomatic and asymptomatic) and each ROM measure. Interaction terms (group × cam morphology or group × sex) were included to examine if relationships between group and hip ROM were influenced by cam morphology or sex. Where appropriate, models were adjusted for sex, age, and cam morphology. Results: An interaction between the relationship between group × cam and internal rotation ROM was found. Symptomatic players with cam morphology had lower internal rotation ROM than controls with cam morphology (adjusted mean difference [AMD] = −4.5°; 95% CI, −7.4° to −1.6°). Hip/groin pain was not associated with internal rotation ROM if cam morphology was absent. A significant interaction was also found for group × sex and BKFO and total rotation ROM. Symptomatic women had lower total rotation ROM than control women (AMD = −8.2°; 95% CI, −14.1° to −2.2°), but no difference was seen in men. BKFO range was lower in men with hip/groin pain compared with control men (AMD = 1.6 cm; 95% CI, 0.3-3.0 cm), but no difference was seen in women. Flexion and external rotation ROM did not differ between symptomatic and control hips. Conclusion: Cam morphology was an effect modifier of the relationship between hip/groin pain and internal rotation ROM. Sex-related differences were also observed in the relationship between hip/groin pain and hip ROM.

The relationship between sitting duration and piriformis syndrome in handcrafters

Background: Handcrafters of serati banten are professionals at risk of developing piriformis syndrome. This can happen because serati banten's working position is sitting for a long time. If this position is carried out continuously for a long period, it can cause musculoskeletal symptoms, namely piriformis syndrome. This study aimed to determine the relationship between sitting duration and piriformis syndrome in handcrafters of serati banten. Methods: This research was an analytical observational study with a cross-sectional study design conducted from June to December 2023. Sampling was done using a purposive sampling technique with a total sample of 106 people in this study. This study's inclusion criteria were handcrafters of serati banten aged 45 to 55. The exclusion criteria included experiencing low back pain. The independent variable measured was sitting duration, determined by filling in the questionnaire, and the dependent variable measured was piriformis syndrome, calculated using the flexion adduction internal rotation test, active piriformis test, and pace test. Results: Based on the chi-square test results, the value of p=0.003 (p<0.05) was obtained, meaning a significant relationship exists. Conclusion: There was a significant relationship between sitting duration and piriformis syndrome in handcrafters of serati banten.

In vivo interrelationships between the gluteus minimus and hip joint capsule in the hip internal rotation position with flexion

BackgroundThe flexion adduction internal rotation (FADIR) test is performed by the combined motions of hip flexion (with knee flexion), adduction, and internal rotation, and can often reproduce anterior hip pain consistent with an individual’s presenting pain. Since it has high sensitivity for intraarticular pathology diagnosis but low specificity, understanding the extraarticular pathology that can induce anterior hip pain in the FADIR test may also be essential. This study hypothesized that the interrelationships between the joint capsule and gluteus minimus differ in individuals with and without FADIR-positive pain and aimed to elucidate the in vivo interrelationships at hip internal rotation in 90°-flexion, which is also often restricted in individuals with FADIR-positive pain.MethodsTen hips were included in the FADIR-positive group, and ten hips without hip pain in the FADIR test were included in a control group. Based on the ultrasound images at the four hip rotation conditions (20° and 10° external rotations, 0° external/internal rotation, and 10° internal rotation), orientation measurements of the gluteus minimus (muscle belly portion) and joint capsule were performed and quantitatively compared between the FADIR-positive and control groups. Additionally, 3 hips of 3 participants were randomly selected from each of the control and FADIR-positive groups for magnetic resonance imaging analysis.ResultsAt 0°-external/internal and 10°-internal rotation, on ultrasound images, fibers of the gluteus minimus and joint capsule in the FADIR-positive group were significantly more oriented in the same direction than those in the control group. Magnetic resonance imaging showed that the loose connective tissue between the gluteus minimus and joint capsule was prominent at 10°-internal rotation in the control group, although this was not apparent in the FADIR-positive group.ConclusionsAt hip internal rotation in 90° flexion, the muscular belly portion of the gluteus minimus and joint capsule were oriented in the same direction to a greater extent in the FADIR-positive group than in the control group owing to a morphological change in the loose connective tissue between them. The pathological changes in the loose connective tissue may inhibit smooth movement of the gluteus minimus relative to the joint capsule in individuals with FADIR-positive pain.

A controlled clinical trial investigating the effects of stretching and compression exercises on electromyography of calf muscles in chronic LBP patients with a deep gluteal syndrome

BackgroundIn deep gluteal syndrome (DGS), the piriformis muscle could impinge the sciatic nerve. The FAIR (flexion adduction internal rotation) test is a provocation test used to identify sciatic nerve irritation caused by this muscle. Compression and stretching exercises are usually prescribed to treat this syndrome. The aim of this study was to compare the effects of these two treatments on surface electromyography (sEMG) of the gastrocnemius and tibialis anterior in patients with low back pain (LBP) and DGS.Materials and methodsForty-five participants were allocated to three groups of stretching exercise, compression or control. In addition to 15 min of heat and 15 min of electrical nerve stimulation for pain relief, participants in the compression exercise (CE) group received self-compression exercise, those in the stretching exercise (SE) group received self-stretching exercise and those in the control group received no extra interventions. For the two intervention groups, three sets of two minutes of exercise with two minutes of rest in between were applied. The sEMG amplitude values of the gastrocnemius and tibialis anterior muscles of the affected buttock side of any one group while performing the FAIR test were compared to the others. Pain and disability were assessed and the changes were compared between the two groups.ResultsAfter the intervention period, no group demonstrated a change in the sEMG of the gastrocnemius or tibialis anterior muscles (p > 0.05). There was no difference in the change in this variable between groups (Mean difference (95% CI) of gastrocnemius was ranged over= -4.04 to 7.72 (-19.44 to 23.14); p = 0.603); (Mean difference (95% CI) of tibialis anterior muscles was ranged from − 2.44 to -6.43 (-18.28 to 9.31); p = 0.550).; Pain and disability also decreased significantly in all three study groups (p < 0.05). However, only the disability of patients who performed stretching exercises improved compared to the compression exercise group (Mean difference (95% CI) = -12.62 (-20.41 to -4.38); p = 0.009).ConclusionNeither stretching nor compression exercises altered the sEMG of the gastrocnemius and tibialis anterior muscles in patients with DGS. Furthermore, performing stretching exercises improved disability compared to the other interventions.Trial registrationThe trial was retrospectively registered in the Iranian Registry of Clinical Trials (www.irct.ir) on 10/01/2017 as IRCT201604178035N4. URL of the record: https://en.irct.ir/trial/8473.

The Evaluation of the Balance Test and MuscleLab Test for the Early Detection of Femoroacetabular Impingement.

Femoroacetabular impingement (FAI) is a common source of hip pain affecting a wide range of subjects. In this work, we assessed two tests, namely the balance test and the MuscleLab test, in comparison with the flexion-abduction-external rotation (FABER) and flexion-adduction-internal rotation (FADIR) tests, in order to evaluate the functionality of the neural-musculoskeletal system of the subjects affected by FAI based on the measurement of biomechanical parameters. Our goal was to investigate the early detection of an altered hip joint and to monitor pathology progression over time. A total of 52 subjects, 29 females and 23 males, with an average age of 42 ± 13 years presenting hip impingement diagnosed using X-ray, were enrolled. Twenty-eight patients without signs of hip impingements were used as the control group. The balance test, which evaluates the capacity of a person to keep the orthostatic position against terrestrial gravity, and the MuscleLab test, which measures the force and power generated by active muscles during a movement, as well as FABER and FADIR tests, were performed in each subject. The balance and MuscleLab tests presented 100% sensitivity and higher sensitivity in FAI diagnosis, with 72.9% and 70.4%, respectively, in comparison with those obtained using FABER and FADIR tests, with 59.6% and 67.3%, respectively. The evaluation of the neural-musculoskeletal system using the balance and MuscleLab tests can help in the early detection of the severity of hip impingements and the assessment of non-operative treatments used over time.

Tibial derotation osteotomies are effective inimproving pain andfunction andavoiding hip arthroscopy inpatients with hip pain-a short-term follow-up.

The primary objective was to determine short-term clinical outcomes following distal tibial derotation osteotomy (DTDO) performed to manage hip pain in the presence of tibial maltorsion and to review how co-existing pathomorphology affected the management. All patients undergoing DTDO for hip pain with tibial rotational deformities recognized as the predominant aetiology were included. Normal tibial torsion range was assumed as 0-40°, measured by trans-malleolar line relative to femoral posterior condyles. All patients had a positive hip impingement test Flexion Adduction Internal Rotation test (FADIR). The patients older than 50 years or presenting with degenerative joint changes and neuromuscular conditions were excluded. Associated ipsilateral MRI-defined intra-articular pathomorphology (cam/pincer), non-cam/pincer-related labral tears and abnormal combined femoral/acetabular version (McKibbin index) were noted. Pre-operative and post-operative functional outcomes were analysed. Thirty-two patients underwent DTDO. Mean tibial torsion was 48.8° (41-63°), average age was 27 years (18-44), and average follow-up was 30 months (16-45). Nine patients (28%) had a co-existing cam/pincer, and eight patients (25%) had an excessive McKibbin index (51-76°). Overall, 63% of all patients (including 54% of patients with co-existing pathology) experienced significant hip functional improvement following DTDO alone. Pre-operative vs 12 months post-operative scores were calculated as follows: International Hip Outcome Tool-12-41 vs 67 (P < 0.01); Hip Outcome Score Activities of Daily Living Scale-47 vs 70 (P < 0.05); and Hip Outcome Score Sport Scale-36 vs 64 (P < 0.05). Patients with hip pain frequently present with a combination of tibial and/or femoral rotational deformity and cam/pincer lesions. It is important to consider tibial maltorsion as an aetiology of hip pain. Tibial derotation with DTDO results in significant clinical and functional recovery within 12 months in symptomatic hip impingement patients even in the presence of co-existing pathomorphology.

Two Novel Clinical Tests for the Diagnosis of Hip Labral Tears

Background: There are few well-studied clinical tests for the diagnosis of hip labral tears. As the differential diagnosis for hip pain is broad, accurate clinical examination is important in guiding advanced imaging and identifying patients who may benefit from surgical management. Purpose: To determine the diagnostic accuracy of 2 novel clinical tests for the diagnosis of hip labral tears. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Clinical examination findings including the Arlington, twist, and flexion-adduction-internal rotation (FADIR)/impingement tests as performed by a fellowship-trained orthopaedic surgeon specializing in hip arthroscopy were obtained from retrospective chart review. The Arlington test ranges the hip from flexion-abduction-external rotation to FADIR while applying subtle internal rotation and external rotation motion. The twist test involves internal rotation and external rotation of the hip while weightbearing. Diagnostic accuracy statistics for each of the tests were calculated using magnetic resonance arthrography as the reference standard. Results: A total of 283 patients were included in the study with a mean age of 40.7 years (range, 13-77 years) and 66.4% were women. The Arlington test was found to have a sensitivity of 0.94 (95% CI, 0.90-0.96), specificity of 0.33 (95% CI, 0.16-0.56), positive predictive value (PPV) of 0.95 (95% CI, 0.92-0.97), and negative predictive value (NPV) of 0.26 (95% CI, 0.13-0.46). The twist test was found to have a sensitivity of 0.68 (95% CI, 0.62-0.73), specificity of 0.72 (95% CI, 0.49-0.88), PPV of 0.97 (95% CI, 0.94-0.99), and NPV of 0.13 (95% CI, 0.08-0.21). The FADIR/impingement test was found to have a sensitivity of 0.43 (95% CI, 0.37-0.49), specificity of 0.56 (95% CI, 0.34-0.75), PPV of 0.93 (95% CI, 0.87-0.97), and NPV of 0.06 (95% CI, 0.03-0.11). The Arlington test was significantly more sensitive than both the twist and FADIR/impingement tests (P < .05), while the twist test was significantly more specific than the Arlington test (P < .05). Conclusion: The Arlington test is more sensitive than the traditional FADIR/impingement test, while the twist test is more specific than the FADIR/impingement test in diagnosing hip labral tears in the hands of an experienced orthopaedic surgeon.

Does Femoroacetabular Impingement Syndrome Affect Self-Reported Burden in Football Players With Hip and Groin Pain?

It is unknown if football players with femoroacetabular impingement (FAI) syndrome report worse burden than those with other causes of hip/groin pain, and to what extent this is mediated by cartilage defects and labral tears. Football players with FAI syndrome would report worse burden than other symptomatic players, with the effect partially mediated by cartilage defects and/or labral tears. Cross-sectional study. Level 4. Football (soccer and Australian football) players (n = 165; 35 women) with hip/groin pain (≥6 months and positive flexion-adduction-internal rotation test) were recruited. Participants completed 2 patient-reported outcome measures (PROMs; the International Hip Outcome Tool-33 [iHOT-33] and Copenhagen Hip and Groin Outcome Score [HAGOS]) and underwent hip radiographs and magnetic resonance imaging (MRI). FAI syndrome was determined to be present when cam and/or pincer morphology were present. Cartilage defects and labral tears were graded as present or absent using MRI. Linear regression models investigated relationships between FAI syndrome (dichotomous independent variable) and PROM scores (dependent variables). Mediation analyses investigated the effect of cartilage defects and labral tears on these relationships. FAI syndrome was not related to PROM scores (unadjusted b values ranged from -4.693 (P = 0.23) to 0.337 (P = 0.93)) and cartilage defects and/or labral tears did not mediate its effect (P = 0.22-0.97). Football players with FAI syndrome did not report worse burden than those with other causes of hip/groin pain. Cartilage defects and/or labral tears did not explain the effect of FAI syndrome on reported burden. FAI syndrome, cartilage defects, and labral tears were prevalent but unrelated to reported burden in symptomatic football players.

Cam morphology is associated with MRI-defined cartilage defects and labral tears: a case–control study of 237 young adult football players with and without hip and groin pain

ObjectiveFootball players are at risk of developing hip osteoarthritis (OA). Cam morphology (present in almost two of every three football players) may explain this heightened risk, but there is limited...

Diagnostic Accuracy of Clinical Tests and Imaging Exams for Femoroacetabular Impingement: An Umbrella Review of Systematic Reviews.

To synthesize available evidence about diagnostic accuracy of clinical tests and imaging examinations for femoroacetabular impingement (FAI) syndrome. Umbrella review. N/A. N/A. N/A. Systematic reviews (SR) indexed in Embase, LIVIVO, PubMed, SCOPUS, the Cochrane Library, and Web of Science were searched in a 2-phase process. SR assessing diagnostic accuracy were considered eligible. From 1520 studies, 6 SR were included, which evaluated 24 primary studies related to FAI syndrome. Of these, 5 SR assessed clinical tests, and a substantial heterogeneity was found concerning reference standards adopted across primary studies, which included arthroscopy, clinical examination (associated or not with imaging exams), intra-articular injections, and open surgery. Most clinical tests presented higher values of sensitivity compared with specificity, although evidence was considered limited because the same primary studies were often included across SR. Nonetheless, evidence around the flexion adduction internal rotation (FADIR) test was considered stronger and its use as a screening tool was consistently supported. Only one SR assessed the accuracy of imaging examinations, which adopted open surgery as the sole reference standard. Most imaging exams presented considerably high values of sensitivity, although specificity values were notably lower. No robust recommendations can be provided for most clinical tests, although the FADIR test, in particular, was consistently supported as a screening tool. Moreover, although imaging examinations showed considerably high sensitivity values, evidence was considered sparse and further research is strongly recommended to validate its use as reference standards for diagnostic accuracy data.

Capsular Healing in Interportal and Periportal Capsulotomy Methods of Hip Arthroscopy.

ObjectiveTo evaluate the midterm outcomes and the capsular healing in patients who had interportal capsulotomy versus periportal capsulotomy of hip arthroscopy.MethodsRetrospectively reviewed 33 patients with labral tear received hip arthroscopy, with an average age of 41 (27‐67) years, including 13 cases of Cam deformity and three cases of Pincer deformity. All patients had positive sign of flexion adduction internal rotation or flexion abduction external rotation. With MRI and radiographic (CT, X plain) imageological examination. MRI showed that all patients had labral tear. Radiographic finding (CT, X plain) showed the pathological changes of acetabular and femoral neck osteophyte. One group with 23 patients were treated with periportal capsulotomy. Another group with 10 patients were treated with interportal capsulotomy. All patients did not close the capsule. Clinical outcomes were measured with the Hip Outcome Score Activities of Daily Living (HOS‐ADL) and the modified Harris Hip Score (mHHS), patient satisfaction measured with visual analogue scale (VAS). The healing of the capsule was evaluated by MRI. MRI showed continuous capsular indicated healing, discontinuous capsular indicated unhealing. Postoperatively 6 months, mHHS and HOS‐ADL were obtained. Randomized controlled trials were used in this study for analysis.ResultsAll patients were followed up with average time of 9.3 months(3‐29 months). The postoperative symptoms were obviously relieved, the VAS decreased from (4.9 ± 0.6) to (1.2 ± 0.2) after 3 months postoperative. Follow up 6 months post‐operation, patients in the interportal group, the mHHS and HOS‐ADL scores improvement were respectively 69.4 ± 9.3 & 70 ± 8.8 pre‐operation, and 92.5 ± 5.0 & 86.6 ± 5.4 post‐operation (P < 0.05); Patients in the periportal group, the mHHS and HOS‐ADL scores improvement were respectively 69.9 ± 15.8, 68.1 ± 15.0 pre‐operation, and 90.1 ± 9.3 & 86.7 ± 7.9 post‐operation (P < 0.05).The differences were statistically significant. Six months after operation, MRI showed that 23 patients with periportal capsulotomy, the capsule have healed, without other complications. Three of the ten patients with interportal capsulotomy were healed and seven were not.ConclusionInterportal and periportal capsulotomy had good outcomes. The technique of periportal capsulotomy had little damage to the joint capsule. Although the capsule did not close, the capsule healed well in postoperative follow‐up. The nonunion rate of the joint capsule was high in the interportal capsulotomy without close the capsule.

Influence of Standardized Procedures on the Reliability of Hip Clinical Assessment

ObjectiveThis study evaluated a standardized and personalized approach to verify the effects of conditions on intrarater and interrater reliability, standard error of measurement, and minimal detectable difference for provocative tests and range-of-motion (ROM) tests used in hip pain assessment: flexion-adduction-internal rotation (FADIR), flexion-abduction-external rotation-extension (FABER), and hip internal rotation with 90° of hip flexion (hip IR). MethodsNineteen participants (mean [± SD] age = 24 ± 2 years; 10 women and 9 men) without lower limb or back pain were recruited. Three raters evaluated each participant during 2 testing sessions, 1 day apart. Raters performed the 3 tests in 4 conditions: classic (C), controlled pressure duration (CPD), subject-specific position (SSP), and mixed (M = CPD + SSP). ResultsFor intrarater reliability, the CPD condition showed the highest intraclass correlation coefficients (ICCs; mean and 95% confidence interval [CI]) for hip IRROM (0.83; 95% CI, 0.53-0.94) and FADIRROM (0.75; 95% CI, 0.60-0.89). The SSP condition showed the highest ICCs for FABERheight (0.71; 95% CI, 0.42-0.87) and FABERROM (0.62; 95% CI, 0.27-0.83). Concerning interrater reliability, the classic condition presented the highest ICCs for FABER variables (height: 0.54; 95% CI, 0.28-0.76; ROM: 0.58; 95% CI, 0.32-0.79) and hip IR ROM (0.72; 95% CI, 0.51-0.87). The CPD condition showed the highest ICC for FADIRROM (0.57; 95% CI, 0.32-0.78). ConclusionIn the conditions of this study, CPD showed the highest ICCs for hip IRROM and FADIRROM, and SSP showed the highest ICCs for FABERheight and FABERROM.

Prevalence of early hip OA features on MRI in high-impact athletes. The femoroacetabular impingement and hip osteoarthritis cohort (FORCe) study

To compare early hip osteoarthritis (OA) features on magnetic resonance imaging (MRI) in high-impact athletes with and without hip and/or groin pain, and to evaluate associations between early hip OA features, the International Hip Outcome Tool (iHOT33) and Copenhagen Hip and Groin Outcome Score (HAGOS). This case-control study evaluated data of the femoroacetabular impingement and hip osteoarthritis cohort (FORCe). One hundred and eighty-two symptomatic (hip and/or groin pain >6 months and positive flexion-adduction-internal-rotation (FADIR) test) and 55 pain-free high-impact athletes (soccer or Australian football (AF)) without definite radiographic hip OA underwent hip MRI. The Scoring Hip Osteoarthritis with MRI (SHOMRI) method quantified and graded the severity of OA features. Each participant completed the iHOT33 and HAGOS. Hip and/or groin pain was associated with higher total SHOMRI (0-96) (mean difference 1.4, 95% CI: 0.7-2.2), labral score (adjusted incidence rate ratio (aIRR) 1.33, 95% CI: 1.1-1.6). Differences in prevalence of cartilage defects, labral tears and paralabral cysts between symptomatic and pain-free participants were inconclusive. There was a lower prevalence of effusion-synovitis in symptomatic participants when compared to pain-free participants (adjusted odds ratio (aOR) 0.46 (95% CI: 0.3-0.8). Early hip OA features were not associated with iHOT33 or HAGOS. A complex and poorly understood relationship exists between hip and/or groin pain and early hip OA features present on MRI in high-impact athletes without radiographic OA. Hip and/or groin pain was associated with higher SHOMRI and labral scores.

Inclusion of the Acetabular Labrum Reduces Simulated Range of Motion of the Hip Compared With Bone Contact Models

PurposeTo determine whether inclusion of the acetabular labrum affects the maximum range of motion (ROM) during simulation of the flexion–adduction–internal rotation impingement examination.MethodsThree-dimensional surface reconstructions of the femur, hemi-pelvis, and labrum from computed tomography arthrography images of 19 participants were used to simulate maximum ROM during the flexion–adduction–internal rotation examination. Simulations were conducted for positions between 70° and 110° flexion and 0° and 20° adduction at 10° increments to measure maximum internal rotation and the position of contact between the femur and acetabular rim (bone-to-bone) or the femur and labrum (bone-to-labrum). Internal rotation angles and clock-face position values were compared between the 2 contact scenarios for each position.ResultsThe ROM in the bone-to-labrum contact model was significantly less than that of the bone-to-bone contact model for all evaluated positions (P ≤ .001, except at 110° flexion and 20° adduction, P = .114). The inclusion of the labrum reduced internal rotation by a median [interquartile range] of 18 [15, 25]° while altering the position of contact on the acetabular clock-face by –0:01 [–0:27, 0:16]. The variability in contact location for the bone-to-labrum contact scenario was nearly double that of the bone-to-bone contact scenario, as indicated by the interquartile range.ConclusionsInclusion of the anatomy of the acetabular labrum in collision models used to simulate impingement examinations reduced the internal rotation ROM by approximately 20° and increased variability in the location of contact relative to the acetabular rim.Clinical RelevanceWhile standard bone-to-bone contact ROM simulations may be informative with respect to the relative change in ROM based on a surgical intervention (e.g., pre- and post-osteochondroplasty for cam-type femoroacetabular impingement), they may not accurately represent the clinical ROM of the joint or the kinematic position at which damage may occur due to shape mismatch between the femur and acetabulum.

Quantification and Reliability of Hip Internal Rotation and the FADIR Test in Supine Position Using a Smartphone Application in an Asymptomatic Population

ObjectiveThe purpose of this study was to quantify and report the intrarater and interrater reliability of hip internal rotation (IR) range of motion supine with the hip and knee at 90° of flexion and for the flexion-adduction-internal rotation (FADIR) test. Hip internal rotation measured in a lying supine position with the hip and knee at 90° of flexion revealed information on hip impairments. To date no simple quantification approach has been presented in this position; therefore, the FADIR test has not been quantified yet. MethodsTwenty participants (mean ± standard deviation [SD] age, 24.0 ± 2.1 years; 10 women and 10 men) without lower-limb or back pain were recruited. Three raters evaluated each participant during 2 testing sessions, 1 day apart. A built-in smartphone compass application was used to obtain the hip IR range of motion in both procedures. ResultsMean (± SD) supine IR was 51.7° (± 9.7°) and 62.6° (± 11.4°) for men and women, respectively. Concerning the FADIR test, mean values were 41.8° (± 9.64°) and 50.1° (± 8.0°) for men and women, respectively. The mean intrarater and interrater reliability coefficients were 0.80 and 0.72 for hip IR and 0.75 and 0.40 for the FADIR test. The standard error of the mean ranged from 4.8° to 8.3° (minimal detectable difference [MDD], 13.3° to 22.9°) for hip IR and from 4.6° to 10.3° (MDD, 12.8° to 28.6°) for the FADIR test. ConclusionOverall, the smartphone compass application is adequate to quantify hip IR in a lying supine position. However, the poor to moderate interrater reliability in the FADIR test and the size of the MDD values suggest that the FADIR test should be standardized.

The piriformis syndrome-aspecial indication for botulinum toxin

The piriformis syndrome (PiS) is apossible cause of gluteal pain radiating into the legs. From apathophysiological anatomical point of view adivision into primary and secondary PiS is made. A primary PiS is based on variants of the course of the sciatic nerve with respect to the piriformis muscle. Asecondary PiS occurs as aresult of hypertrophy, tension and hardening of the piriformis muscle. Muscular hypertrophy causes an impingement syndrome with pressure on the sciatic nerve in the infrapiriform foramen more often than course variants. Atentative diagnosis of PiS can be made based on anamnestic information, clinical signs of strain and the flexion adduction internal rotation (FAIR) test. If asymmetry or hypertrophy exists, the tentative diagnosis is substantiated with the representation of the piriformis muscle in computed tomography (CT). Thus, aCT-supported botulinum injection (BTX) into the piriformis muscle is indicated. This is apathogenetic treatment approach leading to areduction in volume. In most cases asingle treatment is sufficient. Since there are no adverse consequences, the BTX into the piriformis muscle is also justified from adiagnostic and therapeutic point of view in cases of primary PiS if the clinical indications are clear and other causes can be ruled out. In an in-house case series the tentative diagnosis of PiS could be made for 19patients and the effectiveness of BTX was confirmed.

Consensus recommendations on the classification, definition and diagnostic criteria of hip-related pain in young and middle-aged active adults from the International Hip-related Pain Research Network, Zurich 2018

There is no agreement on how to classify, define or diagnose hip-related pain—a common cause of hip and groin pain in young and middle-aged active adults. This complicates the work...

Degenerative changes of the hip following in situ fixation for slipped capital femoral epiphysis: a minimum 18-year follow-up study

In situ fixation (ISF) is currently still the 'gold standard' treatment for slipped capital femoral epiphysis (SCFE) and has shown acceptable results at mid-term follow-up. This study aims to evaluate functional, clinical and radiographic long-term outcomes after this procedure. We reviewed 64 SCFE patients (76 SCFE hips) treated with ISF between 1983 and 1998. 82.9% were stable hips and 17.1% unstable according to Loder's definition. Initial radiographs demonstrated a mild slip in 50%, moderate in 41.3% and severe in 8.7% based on the Southwick angle. Long-term outcomes were assessed using the modified Harris Hip Score (mHHS), University of California at Los Angeles (UCLA) and Tegner activity scores, visual analogue scale (VAS) pain, VAS function, flexion-adduction-internal rotation (FADIR) test, extent of internal-rotation at 90° of hip flexion and Tönnis classification for hip osteoarthritis (OA). 10 (15.6%) SCFE hips were converted to a total hip replacement (THR) after a mean of 16 years. 38 (59.4%) patients underwent a clinical and radiographic examination after a mean follow-up of 23 (range 18-33) years. 12 (18.8%) patients were lost to follow-up. 74% of SCFE hips demonstrated degenerative change on radiography or were converted to THR (Tönnis 1: 33.3%, 2: 18.5%, 3 or THR: 22.2%). There were 3 cases of avascular necrosis (AVN) all in unstable hips. Mean mHHS was 86.8/100, UCLA activity score 7.5/10, Tegner activity score 3.8/10, VAS pain 1.7/10 and VAS function 1.5/10. 20% of SCFE hips were found to have a positive FADIR-test and a limited internal-rotation of 19.7° versus 36.1° (p < 0.001) in contralateral normal hips. This long-term follow-up study of ISF for SCFE shows that although complication rates in terms of AVN are low, a high number of patients become symptomatic and have a limited function. Degenerative changes are common with 22.2% of hips developing end-stage hip OA (Tönnis 3 or THR). It is important that patients and parents are informed about these risks.

Real-Time Assessment of Femoroacetabular Motion Using Radial Gradient Echo Magnetic Resonance Arthrography at 3 Tesla in Routine Clinical Practice: A Pilot Study

To compare femoroacetabular motion in a series of consecutive symptomatic patients with hip pain throughout the range of motion of the hip using a real-time radial gradient echo (GRE) sequence in addition to the routine hip protocol sequences for magnetic resonance (MR) arthrographic assessment of patients with and without clinical femoroacetabular impingement (FAI) syndrome. In particular, we sought to assess whether the additional dynamic sequence could differentiate between patients with and without a positive physical exam maneuver for FAI syndrome. Patients with hip pain referred for conventional hip MR arthrogram including those with and without a positive physical exam maneuver for FAI syndrome were imaged using routine hip MR arthrogram protocol and an additional real-time radial 2-dimensional GRE acquisition at 3Tesla in an axial oblique plane with continuous scanning of a 9mm thick slice through the center of the femoral head-neck axis. Patients who were unable to move through the range of motion were excluded (n= 3). Patients with acetabular dysplasia (defined by a lateral center-edge angle [CEA] of 20°) were also excluded, as were patients had Kellgren and Lawrence scores of > 0. The real-time cine sequence was acquired with the patient actively moving through neutral, flexion, flexion-abduction external-rotation, and flexion-adduction internal rotation (FADIR) positions aiming for 40° of abduction, then 25° of adduction at 80° to 90° flexion. Due to the placement of the coil over the hip, a true FADIR was precluded. Images were evaluated independently by 2 musculoskeletal radiologists measuring the joint space in the anterior, central, and posterior positions at each point during range of motion for femoroacetabular cortical space (FACS). Anterior FACS narrowing was calculated as the ratio of joint space in FADIR:neutral position, with lower ratios indicating greater narrowing. Static metrics including alpha angle, CEA, grade of cartilage loss according the Outerbridge classification, and patient demographics were also recorded. Twenty-two painful hips in 22 patients (11 males and 11 females) with mean age 36years (range, 15-67) were included. Twelve patients had a positive physical exam maneuver for FAI syndrome. The time to perform the dynamic sequence was 3 to 6minutes. Interobserver agreement was strong, with intraclass correlation 0.91 and concordance correlation 0.90. According to results from both readers, patients with impingement on clinical exam had significantly lower anterior FACS ratios compared with those without clinical impingement (reader 1: 0.39 ± 0.10 vs 0.69 ± 0.20, P= .001; reader 2: 0.36 ± 0.07 vs 0.70 ± 0.17, P < .001). Decreased anterior FACS ratio was found to be significantly correlated to increased alpha angle by both readers (reader 1: R=-0.63, P= .002; reader 2: R=-0.67, P= .001) but not significantly correlated to CEA (reader 1: R= 0.13, P= .561; reader 2: R= 0.20, P= .378) or cartilage loss (reader 1: R= 0.03, P= .885; reader 2: R=-0.06, P= .784). Both readers found patients with an anterior FACS ratio of 1/2 to have significantly higher mean alpha angle (reader 1: 62.88 vs 52.79, P= .038; reader 2: 63.50 vs 50.58, P= .006); however, there were no significant differences in cartilage loss (reader 1: P= .133; reader 2: P= .882) or CEA (reader 1: P= .340; reader 2: P= .307). A dynamic radial 2-dimensional-GRE sequence can be added to standard hip MR arthrogram protocols in <6minutes, allowing assessment of dynamic femoroacetabular motion with strong interreader agreement. Patients with impingement on clinical exam had significantly lower anterior FACS ratios between FADIR and neutral positions, compared with those without clinical impingement. Level III, comparative diagnostic investigation.