Radiographic findings of femoroacetabular impingement in capoeira players

Purpose

Capoeira is a Brazilian martial art that requires extreme movements of the hip to perform jumps and kicks. This study evaluated a group of capoeira players to assess the prevalence of femoroacetabular impingement (FAI) in athletes practicing this martial art.

Methods

Twenty-four experienced capoeira players (14 men, 10 women) underwent a diagnostic assessment, including clinical examination and standard radiographs of the pelvis and hips. The α-angle, head–neck offset, crossover sign, acetabular index, lateral centre-edge angle, and the Tönnis grade were assessed using the radiographs. Clinical relationships for any radiographic abnormalities indicating FAI were also evaluated.

Results

Four subjects (17 %) reported pain in their hips. Forty-four hips (91.7 %) had at least one radiographic sign of CAM impingement, and 22 (45.8 %) had an α-angle of more than 60°. Eighteen hips (37.5 %) had at least one sign of pincer impingement and 16 (33.3 %) a positive crossover sign. Sixteen hips (33.3 %) had mixed impingement. There was a significant positive association between having an α-angle of more than 60° and the presence of groin pain (P = 0.002). A reduced femoral head–neck offset (P < 0.001) and an increased α-angle on the anteroposterior radiograph (P = 0.008) were independently associated with a higher Tönnis grade.

Conclusion

High prevalence of radiographic CAM-type FAI among these skilled capoeira players was found. In these subjects, a negative clinical correlation for an increased α-angle was also detected. Additional caution should be exercised whenever subjects with past or present hip pain engage in capoeira.

Level of evidence

Diagnostic, Level III.     

Radiographic prevalence of CAM-type femoroacetabular impingement after open reduction and internal fixation of femoral neck fractures

Purpose

The purpose of this study was to estimate the radiographic prevalence of CAM-type femoroacetabular impingement (FAI) in elderly patients (≥50 years) who have undergone internal fixation for femoral neck fracture.

Methods

A total of 187 frog-leg lateral radiographs of elderly patients who underwent internal fixation for a femoral neck fracture were reviewed by two independent reviewers. The alpha angle, beta angle, and femoral head–neck offset ratio were calculated. The presence of two abnormal radiographic parameters was deemed to be diagnostic of radiographic CAM-type impingement.

Results

Radiographic CAM-type FAI was identified in 157 out of 187 (84 %) patients who underwent internal fixation for fractures of the femoral neck. Moderate-to-good inter-observer reliability was achieved in the measurement of radiographic parameters. With reference to fracture subtypes and prevalence of radiographic features of CAM-type morphology, 97 (72 %) out of 134 patients were positive for CAM in Garden subtypes I and II, whereas 49 (85.9 %) out of 57 patients had radiographic CAM in Garden III and IV subtypes.

Conclusion

There was a high prevalence of CAM-type FAI in patients that underwent surgical fixation of femoral neck fractures. This is significantly higher than the reported prevalence in non-fracture patient populations. The high prevalence of CAM morphology could be related to several factors, including age, fracture morphology, quality of reduction, type of fixation, and fracture healing.

Level of evidence

IV.     

Radiographic signs associated with femoroacetabular impingement occur with high prevalence at all ages in a hospital population

Objectives

Femoroacetabular impingement (FAI) is increasingly diagnosed clinically. Controversy exists about the significance of radiographic findings. Our goal is to determine the prevalence of radiographic FAI types and parameters in a hospital population clinically not suspected of having FAI. In addition we assessed whether pain, age and gender are associated with higher prevalences.

Methods

Three hundred ten patients were included in this retrospective study. After applying the exclusion criteria, 262 patients (522 hips) remained. Two observers scored for radiographic parameters. A generalised estimation equation, Pearson’s χ² test and logistic regression model were used.

Results

Radiographic signs of FAI were absent in only 58 hips (11.1 %). In the 40 hips (7.7 %) with cam impingement, males were more affected (P?<?0.001). In the 330 hips (63.2 %) with pincer impingement, females were more often affected (P?<?0.001). In the 82 hips (15.7 %) with signs of mixed type impingement, male hips were significantly (P?<?0.001) more often affected. Age had some effect on the prevalence of coxa vara, acetabular index and acetabular retroversion. No correlation with pain was found.

Conclusions

In this hospital population, signs occurred at a high rate. Radiographic parameters attributed to FAI are non-specific. Especially radiographic signs attributed to pincer type impingement have a high prevalence.

Key Points

? Femoroacetabular impingement is associated with an abnormal configuration of the hip joint. ? The prevalence of femoroacetabular impingement parameters was high in our study population. ? The diagnosis of femoroacetabular impingement should be made clinically.     

A painful squat test provides limited diagnostic utility in CAM-type femoroacetabular impingement

Purpose

The purpose of this study is to determine the relationship between a symptomatic maximal squat and the presence of radiographic CAM-type femoroacetabular impingement (FAI) on magnetic resonance imaging (MRI) and to determine the sensitivity and specificity of a maximal squat test for the presence of radiographic CAM-type femoral deformity in an adult population.

Methods

In this pilot study, 76 consecutive patients were recruited from an outpatient clinic at McMaster University. All patients presented with pre-arthritic hip pain and were asked to perform a maximal squat. The results of this test were compared to magnetic resonance imaging and magnetic resonance angiographic (MRI and MRA) findings evaluating and characterizing CAM-type FAI deformity.

Results

The sensitivity and specificity of the maximal squat test were 75 % (56.6–88.5 %) and 41 % (27.0–56.8 %), respectively, for CAM-type FAI deformity. The positive and negative likelihood ratios were modest at 1.3 (0.9–1.7) and 0.6 (0.3–1.2), respectively. This means that a 30 % pre-test probability is improved to 36 % following a positive squat test and reduced to 20 % with a negative squat test.

Conclusion

The maximal squat test was found to have marginal incremental diagnostic ability for CAM-type FAI. Its utility in the diagnostic evaluation of FAI remains limited. This survey elucidates areas of research for future studies relevant to the clinical diagnosis of FAI.

Level of evidence

III.     

Results of the PeRception of femOroaCetabular impingEment by Surgeons Survey (PROCESS)

Purpose

Currently, there is a lack of high-level evidence addressing the variety of treatment options available for patients diagnosed with femoroacetabular impingement (FAI). The objective was to determine the current state of practice for FAI in Canada.

Methods

A questionnaire was developed and pretested to address the current state of knowledge among orthopaedic surgeons regarding FAI treatment using a focus group of experts, reviewing prior surveys, and reviewing online guidelines addressing surgical interventions for FAI. The membership of the Canadian Orthopaedic Association (COA) was surveyed through email and mail in both French and English.

Results

Two hundred and two surveys were obtained (20 % response rate), of which 74.3 % of respondents manage patients under age 40 with hip pain. Most surgeons (62 %) considered failure of non-operative management as the most important indication for the surgical management of FAI, usually by treating both bony and soft tissue damage (54.4 %). The majority of surgeons were unsure of the existence of evidence supporting the best clinical test for FAI, the use of a diagnostic intra-articular injection for diagnosis of FAI, and for non-operative management of FAI. One in four respondents supported a sham surgery (24.8 %) control arm for a trial evaluating the impact of surgical intervention on FAI.

Conclusions

This survey elucidates areas of research for future studies relevant to FAI and highlights controversial areas of treatment. The results suggest that the current management of FAI by members of the COA is limited by a lack of awareness of high-level evidence.

Level of evidence

III.     

Pre-operative intra-articular hip injection as a predictor of short-term outcome following arthroscopic management of femoroacetabular impingement

Purpose

Diagnostic hip injections are often used to confirm intra-articular pathology prior to arthroscopic treatment for femoroacetabular impingement (FAI). However, little is known whether the type of response correlates with the post-operative functional outcomes. The purpose of this study is to document the ability of a diagnostic hip injection to predict short-term functional outcomes following arthroscopic surgical management.

Methods

A prospective cohort of 52 patients diagnosed with FAI who had an intra-articular hip injection prior to arthroscopic surgery was evaluated. A pain diary was used during the 2 weeks after hip injection to document response. In addition, the modified Harris Hip Score (mHHS) was administered preoperatively and 6 months post-operatively to assess functional outcomes. The relationship between response to an intra-articular hip injection and mHHS scores 6 months after FAI surgery was evaluated.

Results

Overall, 42 of 52 (81 %) patients diagnosed with FAI achieved pain relief from the hip injection. Outcomes according to mHHS scores improved significantly at the 6-month follow-up visit (19 points, 95 % CI 15–24, p = 0.001). The therapeutic utility of the hip injection suggested that lack of pain relief predicted a lack of functional improvement following arthroscopic surgery.

Conclusion

In this study, the data suggests that a positive response from an intra-articular hip injection is not a strong predictor of short-term functional outcomes following arthroscopic management of FAI. However, a negative response from an intra-articular hip injection may predict a higher likelihood of having a negative result from surgery.

Level of evidence

Level II.     

Surgical management of labral tears during femoroacetabular impingement surgery: a systematic review

Purpose

This systematic review explored reported outcomes addressing femoroacetabular impingement (FAI), specifically those comparing labral debridement to labral repair. In addition, the quality of the evidence was evaluated for the purposes of making treatment recommendations.

Methods

Three databases (MEDLINE, EMBASE, and PubMed) were searched for comparative studies involving labral repair and debridement during FAI surgery. Two reviewers conducted a title, abstract, and full-text review of eligible studies and the references of these studies. Inclusion and exclusion criteria were applied to the searched studies, data were extracted, and a quality assessment was completed for included studies.

Results

Six eligible studies involving 490 patients were identified. The most commonly reported outcome measure was the modified Harris hip score (MHHS) (50 %). All studies reported that labral repair had greater postoperative improvements in functional scores (modified Harris hip, non-arthritic hip, hip outcome, and Merle d’Aubigne scores) compared to labral debridement. Five studies reported statistically significant improvements with labral repair. MHHS were pooled to demonstrate a clinically important difference in favor of labral repair by 7.4 points in three studies. The mean individual study quality can be considered fair. However, the overall quality of the body of evidence in this review is rated as low according to GRADE guidelines.

Conclusions

This review demonstrates a reporting of better clinical outcomes with labral repair compared to labral debridement in all studies with five of six studies reporting statistically significant improvements (of repair over debridement). However, given the lack of high quality evidence and associated limitations in study design, these results should be interpreted with caution. Consequently, definitive treatment recommendations require further investigation with well-conducted clinical trials. This systematic review enables the discussion of best evidence practice for the surgical managing of a labral tear associated with FAI.

Level of evidence

III.     

Femoroacetabular impingement: normal values of the quantitative morphometric parameters in asymptomatic hips

Objective

To determine the means and the reference intervals of the quantitative morphometric parameters of femoroacetabular impingement (FAI) in normal hips with high-resolution computed tomography (CT).

Methods

We prospectively included 94 adult individuals who underwent CT for thoracic, abdominal or urologic pathologies. Patients with a clinical history of hip pathology and/or with osteoarthritis on CT were excluded. We calculated means and 95 % reference intervals for imaging signs of cam-type (alpha angle at 90° and 45° and femoral head–neck offset) and pincer-type impingement (acetabular version angle, lateral centre-edge angle and acetabular index).

Results

The 95 % reference interval limits were all far beyond the abnormal thresholds found in the literature for cam-type and to a lesser extent for pincer-type FAI. The upper limits of the reference intervals for the alpha angles (at 90°/45°) were 68°/83° (men) and 69°/84° (women), compared to thresholds from the literature (50°, 55° or 60°). Reference intervals were similar between genders for cam-type parameters, and slightly differed for pincer-type.

Conclusion

The 95 % reference intervals of morphometric measurements of FAI in asymptomatic hips were beyond the abnormal thresholds, which was especially true for cam-type FAI. Our results suggest the need for redefining the current morphometric parameters used in the diagnosis of FAI.

Key Points

? 95 % reference intervals limits of FAI morphotype were beyond currently defined thresholds. ? Reference intervals of pincer-type morphotype measurements were close to current definitions. ? Reference intervals of cam-type morphotype measurements were far beyond the current definitions. ? Current morphometric definitions of cam-type morphotype should be used with care.     

Can hip impingement be mistaken for tendon pain in the groin? A long-term follow-up of tenotomy for groin pain in athletes

Purpose

There are several reports on the association between pubalgia and intra-articular hip disorders. The purpose of this study was to evaluate the long-term outcome in athletes who underwent tenotomy due to long-standing groin pain. A secondary purpose was evaluating the frequency of femoro-acetabular impingement (FAI) and its impact on the long-term outcome.

Methods

Thirty-two high-level male athletes treated with adductor tenotomy, rectus abdominis tenotomy or both were included. At a median follow-up time of 6 years after the tenotomy, the subjects underwent standardised clinical examination, plain radiographs, completed web-based health-related patient-reported outcomes, including iHOT12, HAGOS (six subscales), EQ-5D (two subscales), HSAS for physical activity level and a VAS for overall hip function. Furthermore, patient satisfaction and return to sports were documented.

Results

Twenty-four of the 32 (75 %) athletes were satisfied with the outcome of the tenotomy, and 22 of the athletes (69 %) were able to return to their pre-injury sport. Before the long-term follow-up, two of these satisfied athletes had undergone repeat surgery (one hip arthroscopy due to FAI and one repeat tenotomy). Of the 24 satisfied athletes, eight (33 %) had a positive hip impingement test at the follow-up. Of the remaining eight athletes not satisfied with the outcome, only one returned to their pre-injury sport and three had undergone hip arthroscopy prior to follow-up. Five had positive hip impingement tests which was significantly more frequently than in the satisfied group (p = 0.008). The group with a positive hip impingement test reported significantly more pain and symptoms, more hip problems during sports and physical activity, as well as lower hip-related quality of life according to the HAGOS scores (p < 0.05), at follow-up.

Conclusion

Tenotomy for pubalgia yielded a satisfactory long-term outcome, with three of four athletes being able to return to their pre-injury sport. The athletes that did not return to their pre-injury sport had higher frequency of positive hip impingement test and inferior functional outcome compared with the athletes that did return to their pre-injury sport. It is therefore recommended that the hip should be carefully evaluated for hip impingement before tenotomy is considered as treatment for athletes with pubalgia.

Level of evidence

Retrospective case series, Level IV.     

Femoroacetabular impingement in elite ice hockey players

Purpose

The purpose of this study is to evaluate the presence of clinical and radiological femoroacetabular impingement (FAI) in elite ice hockey players and compare it to a control group of non-athletes.

Methods

Forty participants (20 non-athletes and 20 elite ice hockey athletes) underwent an evaluation of their hip joint, including assessment of range of motion and special provocative impingement tests. Two musculoskeletal radiologists assessed MRIs completed on each participant for radiological findings associated with FAI, including alpha angle, acetabular version angle, acetabular depth, and/or a lateral centre edge angle, and findings of labral and cartilage degeneration. A comparative analysis of the clinical and radiological findings was subsequently completed.

Results

There was a significant difference in the radiological CAM impingement measured by mean alpha angle between both groups (non-athletes: 43.2 degrees, SD 9.7; and athletes: 54.2 degrees, SD 12 (p = 0.003)). There were no statistically significant differences between the groups upon evaluating PINCER impingement. There were no statistically significant differences in clinical examination findings between both groups.

Conclusion

MRI evidence suggests that CAM impingement is more common in the elite ice hockey athlete in comparison with non-athletes. However, as this is a pilot study examining findings in asymptomatic individuals, there is a need for a longitudinal prospective cohort study. In keeping with this, sufficient, long-term follow-up is required to assess at what point, if any, these subjects with radiological findings become symptomatic.

Level of evidence

Cross-sectional cohort study, Level III.     

Femoral head-neck offset measurements in 339 subjects: distribution and implications for femoroacetabular impingement

Purpose

The α-angle is a frequently used measurement to quantify head-neck offset pathology in cam-type femoroacetabular impingement. However, diverging norm values and reference intervals have been described, especially in men.

Methods

The α-angle, the head-neck offset ratio and the triangular index were measured on anteroposterior and lateral radiographs of 339 (170 men and 169 women) subjects without evident underlying hip pathology.

Results

For male subjects, the mean α-angle was 49.4° (SD 10.5°) on anteroposterior and 49.1° (SD 10.6°) on lateral radiographs, whereas for female subjects, it was 45.0° (SD 8.0°) and 46.1° (SD 9.9°), respectively. Thus, calculated upper limits of reference intervals in the population screened were 70° for both radiographic projections in men and 61° (anteroposterior) and 66° (lateral) in women.

Conclusion

These data substantiate recent findings that the pathological threshold of the α-angle in male subjects may be lower than that previously assumed.

Level of evidence

Diagnostic, Level III.     

Modest mid-term outcomes after isolated arthroscopic debridement of acetabular labral tears

Purpose

Currently, there is a paucity of literature regarding outcomes after isolated labral debridement. The purpose of this study was to (1) report the reoperation rate following isolated labral debridement, (2) report clinical and functional outcomes after labral debridement with a minimum 2-year follow-up and (3) identify risk factors for worse clinical and functional outcomes. It was hypothesized that inferior outcomes are associated with an increasing Tönnis grade and those with untreated femoral acetabular impingement (FAI).

Methods

The records of patients undergoing hip arthroscopy between 1998 and 2005 were reviewed. Patients with labral tears who underwent isolated arthroscopic labral debridement were identified. Kaplan–Meier estimate of failure (defined as subsequent surgery) was performed for all patients. Patients with minimum 2-year follow-up were assessed with Modified Harris Hip Score (MHHS) and Hip Outcome Score (HOS). Univariate analysis was then performed to assess which factors were associated with worse clinical and functional outcomes.

Results

Fifty-nine hips in 57 patients met our inclusion criteria (39 females, 18 males) with a mean age of 46 ± 14 years and mean follow-up of 5 (range 2–14) years. Overall, 45 % of the hips failed for repeat surgery (20 %) or rating for hip function as abnormal or severely abnormal (25 %). Twelve hips (20 %) required subsequent surgical intervention at a mean 23 (range 6–60) months (7 total hip arthroplasties, 2 open revisions, 3 arthroscopic revisions). Of the remaining hips, mean MHHS was 83.4 ± 19.7, mean HOS ADL score was 83.8 ± 21.3 and mean HOS sport score was 70.6 ± 32.9, with 33 of 41 (75 %) reporting normal or nearly normal current level of function. Univariate analysis revealed that hips with untreated bony impingement (p = 0.01) or requiring concomitant chondroplasty (p = 0.03) had inferior clinical outcome scores.

Conclusions

Isolated arthroscopic labral debridement for hip labral tears had 45 % combined poor results when strictly defining failure as repeat surgery or abnormal hip rating. Untreated FAI and concomitant chondroplasty were risk factors for inferior outcome. We recommend concomitant treatment for bony impingement lesions and preservation of the labrum whenever possible.

Level of evidence

Retrospective case series, Level IV.     

Limited therapeutic benefits of intra-articular cortisone injection for patients with femoro-acetabular impingement and labral tear

Purpose

Intra-articular (IA) hip cortisone injection is commonly performed as a therapeutic modality in patients with femoral acetabular impingement (FAI). To our knowledge, there is no published data evaluating the clinical benefit of these injections. The purpose of this study was to assess the efficacy of therapeutic IA cortisone injection in these patients.

Methods

At our institution, patients with FAI and labral tear prospectively recorded their numerical rating scale (NRS) pain scores pre-injection, during post-injection anaesthetic phase, and at 14 days post-injection. From this cohort, all patients treated with guided IA cortisone injection, no radiographic evidence of arthritis (Tönnis grade 0 or 1) and pain relief during the anaesthetic phase of the IA injection were included. An absolute change of two points on the NRS score was considered the minimal amount of clinically significant pain relief. Pain scores were compared between the different types of steroid injected.

Results

Fifty-four patients (35 females, 19 males) with a mean age of 32 ± 12 years were included. Average median pre-injection NRS score was 7.0 (range 2.5–10.0), post-injection anaesthetic phase was 1.0 (range 0.0–5.0), and 14 day post-injection was 5.0 (range 0.0–10.0). As a group, NRS scores significantly diminished from post-injection anaesthetic phase to 14 days post-injection (p < 0.001). At 14 days post-injection, only 20 patients (37 %) and at 6 weeks, only 3 patients (6 %) reported a clinically significant decrease in pain. Average duration of pain relief was 9.8 days. There was no difference in pain reduction between steroid preparations.

Conclusion

In patients with symptomatic FAI and labral tear, intra-articular cortisone injection has limited clinical benefit as a therapeutic modality. However, anaesthetic-only IA injections for patients who may be candidates for hip arthroscopy can be a useful diagnostic tool.

Level of evidence

Therapeutic case series, Level IV.     

Femoroacetabular impingement: is hyaluronic acid effective?

Purpose

Femoroacetabular impingement may predispose to the development of hip osteoarthritis. Conservative treatments are effective in the short term, but surgery is often required. Aim of this paper was to report the short-term results on hip pain and function after ultrasound-guided injections of hyaluronic acid.

Methods

In this open prospective trial, twenty patients suffering from mild femoroacetabular impingement were enrolled. Each patient received a 2-ml intra-articular ultrasound-guided injection of hyaluronic acid at baseline and after 40 days; the same dosing schedule was repeated after 6 months. The clinical evaluation was performed at baseline and after 6 and 12 months of follow-up. Pain score, Lequesne Index, Harris Hip Score and anti-inflammatory medication consumption were measured. Adverse events were also registered.

Results

Twenty-three hips (3 bilateral cases) were treated. Pain decreased from 6.7 ± 1.3 to 3.7 ± 1.8 and to 1.7 ± 1.8 after 6 and 12 months, respectively; Lequesne Index was reduced and the mean Harris Hip Score improved from 83.3 ± 6 before treatment to 88.2 ± 4.7 at 12 months. Consumption of anti-inflammatory drugs was also reduced, from 14 to 4 subjects and from 3.6 ± 2.2 to 1.3 ± 1.3 tablets/week. Local side effects after injection were observed only in 2 cases.

Conclusions

Hyaluronic acid is safe and effective in the treatment of mild femoroacetabular impingement, with significant pain reduction and function improvement.

Level of evidence

IV.     

Complications in hip arthroscopy: necessity of supervision during the learning curve

Purpose

The aim of this study was to determine whether the learning curve of arthroscopic treatment of femoroacetabular impingement (FAI) could be verified by analyzing the complication rate of this procedure. Additionally, it was investigated whether supervision by an experienced surgeon leads to a steeper learning curve (lower number of complications) when starting to perform arthroscopic FAI treatment.

Methods

The complications occurring in 317 consecutive patients treated with the sole diagnosis of FAI were analyzed. 256 patients (collective A) were treated by surgeon A between June 2005 and January 2010. Sixty-one patients (collective B) were treated by surgeon B between August 2008 and December 2009. From January to June 2008, surgeon B performed many hip arthroscopies under supervision of surgeon A. Complications were recorded in a central complication register. Statistic analysis of the complication rates was performed using Fischer’s exact T test.

Results

Subdividing collective A chronologically into thirds a significant decline of complications (p = 0.0044) was found with growing experience of the surgeon. Comparing the first 61 patients of both surgeons a significantly lower complication rate was discovered in the patients of surgeon B (p = 0.0375). In total there were 21 complications (6.6 %; CI 4.4–9.9 %). The observed complication rate was 7.0 % in collective A and 4.9 % in collective B.

Conclusion

The learning curve can be comprehended by the distribution of complications in collective A. Having spent 6 months performing under supervision of surgeon A, surgeon B has a lower complication rate than surgeon A when comparing the first 61 patients each surgeon operated on. This implies that surgeon B benefits from the experience of surgeon A. According to this analysis, beginners in arthroscopic FAI treatment should be taught at a specialized centre to reduce the number of complications.

Level of evidence

III.     

Incidence of greater trochanteric pain syndrome in patients suspected for femoroacetabular impingement evaluated using magnetic resonance arthrography of the hip

Objectives:

We evaluated the incidence of greater trochanter pain syndrome (GTPS) in patients who underwent magnetic resonance arthrography (MRA) of the hip for a suspected femoroacetabular impingement (FAI) syndrome.

Methods:

Hip MRA performed at our institution (3/2012–1/2014) were reviewed. The absence/presence of FAI (cam, pincer, and mixed) was noted. GTPS diagnosis was based on gluteus medius/minimus tendinopathy/tears, trochanteric bursitis, fascia lata thickening, and trochanter bone oedema/erosion. Subgroup analysis for age (under/over 40 years) and FAI type (cam, pincer, and mixed) was also performed.

Results:

N = 189 patients were included (n = 125 males; age 39 ± 12 years). FAI was diagnosed in n = 133 (70, 4%): cam type, n = 85 (63, 9%); pincer type, n = 22 (16, 6%); and mixed type, n = 26 (19, 5%). N = 72 patients (38.1%) had tendinopathy, n = 14 (7.4%) had trochanter erosion, n = 31 (16.4%) had bursitis, n = 4 had bone oedema (2.1%), and n = 3 (1.6%) had fascia lata thickening, resulting in GTPS diagnosis in n = 74 patients (39.2%). The association of normal hip morphology/GTPS was significantly higher (P = 0.023) than that of FAI/GTPS. Under 40 years, GTPS incidence was higher in patients with normal hip and pincer-type FAI (P = 0.028). Over 40 years, no difference between patients with/without FAI (P = 0.119) was seen.

Conclusions:

GTPS was more frequently observed in patients with normal hip morphology than in patients with FAI, particularly in patients under 40.

     

MRI morphometric hip comparison analysis of anterior acetabular labral tears

Objective

Anterior (3 o’clock) acetabular labral tears (AALTs) have been reported to be associated with iliopsoas impingement (IPI). However, no study has examined the association between anatomical bony variables of the hip joint and AALTs. The purpose of this study was to evaluate the association between AALTs, femoroacetabular impingement (FAI) and other bony variables of the hip.

Material and methods

Seventy-six out of 274 hip MRI records met the inclusion criteria. Two independent blinded investigators evaluated the location of acetabular labral tears (ALTs), edema at the musculotendinous junction of the iliopsoas insertion, femoral neck anteversion angle, femoral neck shaft angle, acetabular anteversion angle, alpha angle, lateral central edge angle (LCEA), acetabular index, and acetabular depth. Comparison analyses between groups were performed.

Results

Twenty-two patients had no ALTs (controls), 19 patients had AALTs, and 35 patients had ALTs not isolated at the 3 o’clock position (25 with cam-bony deformities [FAI-cam] and 10 with pincer-bony deformities [FAI-pincer]). The alpha angle mean was significantly higher (p?<?0.001) in the FAI-cam group (62.7º, 95 % confidence interval [CI]: 56.2–69.2º) compared with the AALTs group (46.9º, 95 % CI: 40.1–53.7º). The LCEA mean was significantly higher (p?<?0.001) in FAI-pincer group (41.9º, 95 % CI: 39.3º–44.5º) compared to AALTs group (29.4º, 95 % CI: 24.2º–34.6º). There was no statistically significant difference in any of the bony variables between the controls and the AALTs group.

Conclusion

Our study demonstrated that AALTs are pathologically distinct and not associated with FAI or other bony abnormalities. This supports the previous studies, which proposed that AALTs are associated with IPI.