Utilization trends for MR arthrography of the hip and shoulder: a retrospective cross-sectional analysis of 20-year data from a tertiary care academic medical center

OBJECTIVE

The purpose of this study is to analyze changes in the utilization of MRA of the hip and shoulder at a large tertiary care academic medical center during a period of significant technological advancements over the last 20 years.

MATERIALS AND METHODS

This retrospective cross-sectional analysis identified MRA of the hip and shoulder performed at our institution over a 20-year period (2/2003-2/2023) in relation to the total number of MR hip and shoulder examinations during the same period. Patient characteristics and referring provider demographic information were extracted. Descriptive statistics and trend analysis were performed.

RESULTS

The total number of MRIs of the hip and shoulder increased overall, with small dips in 2020 and 2022. MRA of the hip increased significantly over the first 10 years of the study period (p = 0.0005), while MRA of the shoulder did not change significantly (p = 0.33). The proportion of both MRA of the hip and shoulder declined over the last 10 years (hip, p = 0.0056; shoulder, p = 0.0017). Over the same period, there was significant increase in the proportion of examinations performed at 3 Tesla versus 1.5 (p < 0.0001).

CONCLUSION

Overall, there was a downward trend in MR shoulder and hip arthrogram utilization in the second half of this 20-year study period. However, utilization varied somewhat by referring specialties and credentials. These changes are likely reflective of both improvements in image quality and evolving practice recommendations. Awareness of such trends may be valuable in ensuring appropriate patient care, as well as for anticipating the needs of a musculoskeletal radiology practice.

Defining hip osteoarthritis feature prevalence, severity, and change using the Scoring of Hip Osteoarthritis with MRI (SHOMRI)

OBJECTIVE

To define the reporting of Scoring Hip Osteoarthritis with MRI (SHOMRI) feature prevalence and severity, and to develop criteria to monitor feature change in longitudinal investigations.

METHODS

Twenty-five participants (50 hips) of the femoroacetabular impingement and hip osteoarthritis cohort study underwent baseline and 2-year follow-up 3 T hip MRIs. Eight hip OA features were assessed using the SHOMRI. All MRIs were read paired with knowledge of timepoint by two blinded musculoskeletal radiologists. We provide definitions to report SHOMRI feature prevalence, severity, and longitudinal change.

RESULTS

We report clear definitions for SHOMRI feature prevalence, severity, and change. When we applied the definitions to the studied cohort, we could detect the prevalence, severity, and change of hip OA features. For example, 88% of hips had labral tears (34% graded as severe tears) and 76% had cartilage defects (42% graded as full thickness). Over 70% of hips had feature change over 2 years, highlighting the sensitivity of SHOMRI definitions to assess longitudinal change of hip OA features. Intra-reader reliability was almost perfect (weighted (w)-kappa 0.86 to 1.00), with inter-reader reliability substantial to almost perfect (w-kappa 0.80 to 1.00).

CONCLUSION

This study is the first to provide definitions to report SHOMRI feature prevalence, severity, and change. The proposed definitions will enable comparison between hip MRI studies and improve our understanding of hip OA pathogenesis.

No Difference in Patient-Reported Outcomes for Periacetabular Osteotomy and Hip Arthroscopy With Capsular Plication in the Setting of Borderline Hip Dysplasia: A Propensity-Matched Multicenter Study With Minimum 5-Year Follow-Up

PURPOSE

To compare minimum 5-year patient-reported outcome measures after hip arthroscopy (HA) and periacetabular osteotomy (PAO) for borderline hip dysplasia.

METHODS

Hips with a lateral center-edge angle (LCEA) between 18° and less than 25° that underwent either PAO or HA were selected from 2 institutions. The exclusion criteria were as follows: LCEA less than 18°, Tönnis osteoarthritis grade greater than 1, prior hip surgical procedures, active inflammatory disease, Workers' Compensation, and concomitant surgery. Patients underwent propensity matching based on age, sex, body mass index, and Tönnis osteoarthritis grade. Patient-reported outcome measures included the modified Harris Hip Score, as well as calculation of the minimal clinically important difference, patient acceptable symptom state, and maximum outcome improvement satisfaction threshold. Preoperative radiographic predictors included comparison of the Femoro-epiphyseal Acetabular Roof index and ligamentum teres lesions.

RESULTS

A total of 28 PAO patients underwent propensity matching to 49 HA patients. The 2 groups were similar in terms of mean age, sex, preoperative body mass index, and LCEA. The PAO group had a longer mean follow-up period (95.8 months vs 81.3 months, P = .001). The mean Femoro-epiphyseal Acetabular Roof index was significantly lower preoperatively in the HA group (P < .001). The 2 groups showed similar and significant improvements in the mean modified Harris Hip Score from preoperatively to latest follow-up (P < .001). The relative risk of subsequent surgery in the PAO group was 3.49 (P = .024), mostly attributed to hardware removal (25%). The revision rate was 3.6% in the PAO group and 8.2% in the HA group (P = .65). One patient in the PAO group required revision HA for intra-articular adhesions. Three of the patients requiring revision in the HA group underwent PAO because of persistent pain, and one underwent revision HA alone. Conversion to total hip arthroplasty was required in 1 patient in the HA group and no patients in the PAO group.

CONCLUSIONS

Both PAO and HA with capsular plication provide borderline hip dysplasia patients with clinically significant improvements and low revision rates at a minimum of 5 years postoperatively.

LEVEL OF EVIDENCE

Level III, retrospective, comparative therapeutic trial.

SSR white paper: guidelines for utilization and performance of direct MR arthrography

OBJECTIVE

Direct magnetic resonance arthrography (dMRA) is often considered the most accurate imaging modality for the evaluation of intra-articular structures, but utilization and performance vary widely without consensus. The purpose of this white paper is to develop consensus recommendations on behalf of the Society of Skeletal Radiology (SSR) based on published literature and expert opinion.

MATERIALS AND METHODS

The Standards and Guidelines Committee of the SSR identified guidelines for utilization and performance of dMRA as an important topic for study and invited all SSR members with expertise and interest to volunteer for the white paper panel. This panel was tasked with determining an outline, reviewing the relevant literature, preparing a written document summarizing the issues and controversies, and providing recommendations.

RESULTS

Twelve SSR members with expertise in dMRA formed the ad hoc white paper authorship committee. The published literature on dMRA was reviewed and summarized, focusing on clinical indications, technical considerations, safety, imaging protocols, complications, controversies, and gaps in knowledge. Recommendations for the utilization and performance of dMRA in the shoulder, elbow, wrist, hip, knee, and ankle/foot regions were developed in group consensus.

CONCLUSION

Although direct MR arthrography has been previously used for a wide variety of clinical indications, the authorship panel recommends more selective application of this minimally invasive procedure. At present, direct MR arthrography remains an important procedure in the armamentarium of the musculoskeletal radiologist and is especially valuable when conventional MRI is indeterminant or results are discrepant with clinical evaluation.

Factors influencing patient-reported outcomes following periacetabular osteotomy and open osteochondroplasty in the setting of borderline hip dysplasia

Aims

This study reports mid-term outcomes after periacetabular osteotomy (PAO) exclusively in a borderline hip dysplasia (BHD) population to provide a contrast to published outcomes for arthroscopic surgery of the hip in BHD.

Methods

We identified 42 hips in 40 patients treated between January 2009 and January 2016 with BHD defined as a lateral centre-edge angle (LCEA) of ≥ 18° but < 25°. A minimum five-year follow-up was available. Patient-reported outcomes (PROMs) including Tegner score, subjective hip value (SHV), modified Harris Hip Score (mHHS), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were assessed. The following morphological parameters were evaluated: LCEA, acetabular index (AI), α angle, Tönnis staging, acetabular retroversion, femoral version, femoroepiphyseal acetabular roof index (FEAR), iliocapsularis to rectus femoris ratio (IC/RF), and labral and ligamentum teres (LT) pathology.

Results

The mean follow-up was 96 months (67 to 139). The SHV, mHHS, WOMAC, and Tegner scores significantly improved (p < 0.001) at last follow-up. According to SHV and mHHS, there were three hips (7%) with poor results (SHV < 70), three (7%) with a fair score (70 to 79), eight (19%) with good results (80 to 89), and 28 (67%) who scored excellent (> 90) at the last follow-up. There were 11 subsequent operations: nine implant removals due to local irritation, one resection of postoperative heterotopic ossification, and one hip arthroscopy for intra-articular adhesions. No hips were converted to total hip arthroplasty at last follow-up. The presence of preoperative labral lesions or LT lesions did not influence any PROMs at last follow-up. From the three hips that had poor PROMs, two have developed severe osteoarthritis (> Tönnis II), presumably due to surgical overcorrection (postoperative AI < -10°).

Conclusion

PAO is reliable in treating BHD with favourable mid-term outcomes. Concomitant LT and labral lesions did not negatively influence outcomes in our cohort. Technical accuracy with avoidance of overcorrection is essential in achieving successful outcomes.

Hip Magnetic Resonance Arthrography Using Normal Saline Is Less Accurate Than Using a Gadolinium-Based Contrast Agent

PURPOSE

To evaluate the diagnostic performance of hip magnetic resonance (MR) arthrography with a gadolinium-based contrast agent (GBCA) or normal saline (NS) for intra-articular pathologies.

METHODS

This retrospective study was approved by the institutional review board of our hospital, and the requirement for informed consent was waived. The study included 37 consecutive patients (38 hips; 21 right hips; 24 males; mean age, 33 years) who underwent GBCA-hip MR arthrography from July 2011 to January 2020 and 30 consecutive patients (30 hips; 20 right hips; 21 males; mean age, 40 years) who underwent NS-hip MR arthrography from January 2018 to June 2020. All images were evaluated twice independently by two radiologists blinded to the arthroscopic findings for the presence of labral tears, cartilage abnormalities, or ligamentum teres tears. Intrareader and interreader reliabilities were determined by kappa values (k) using the chi-squared test, and diagnostic performance was evaluated based on the arthroscopic findings. A P value less than .05 was considered to indicate statistical significance.

RESULTS

Intra-reader reliability in the detection of intra-articular pathologies ranged from moderate to almost perfect (k = 0.510-0.840) and inter-reader reliability ranged from moderate to substantial (k = 0.441-0.695) for GBCA- and NS-hip MR arthrography. The diagnostic accuracy of GBCA- and NS-hip MR arthrography was as follows: 81.6-92.1% and 66.7-73.3% for labral tears, respectively; 68.4-86.8% and 63.3-70.0% for cartilage abnormality, respectively; and 68.4-76.3% and 50.0-56.7% for ligamentum teres tears, respectively.

CONCLUSION

NS-hip MR arthrography may be less accurate than GBCA-hip MR arthrography. LEVEL OF EVIDENCE: Level II of development of diagnostic criteria (consecutive patients with consistently applied reference standard and blinding).

The posterior crescent sign on MRI and MR arthrography: is it a marker of hip dysplasia and instability?

OBJECTIVE

To evaluate the prevalence of the 'posterior crescent sign' in symptomatic patients referred for MRI/MR arthrogram of the hip and identify any correlation with imaging features of joint pathology.

MATERIALS AND METHODS

Retrospective imaging assessment of a cohort of 1462 hips, from 1380 included MR examinations (82 bilateral) retrieved from a search of all examinations in patients 16-50 years old from June 2018 to June 2021, with median age 45.8 years (range 17.8-50.0) and 936 hips (64%) in women. Radiographic and MR findings related to hip dysplasia, femoroacetabular impingement and osteoarthritis were assessed.

RESULTS

Fifty-one hips (3.5%) were positive for the posterior crescent sign, median age of 45.8 years (range 17.8-50.0) and 29 (58%) in women. Radiographic findings included the following: mean lateral centre edge angle (LCEA) 22.2° (± 7.8°) with LCEA < 20° in 15 (31%) and LCEA 20-25° in 17 (35%) and mean acetabular index (AI) of 13.1° (± 5.8°) with AI > 13° in 22 (45%). MR findings included the following: mean anterior acetabular sector angle (AASA) 54.3° (± 9.8°), mean posterior acetabular sector angle (PASA) 92.7° (± 7.0°), labral tear at 3-4 o'clock in 20 (39%), high-grade acetabular chondral loss in 42 (83%) and ligamentum teres abnormality in 20 (39%).

CONCLUSION

The posterior crescent sign occurs in 3.5% of symptomatic young and middle-aged adults on MR. It is associated with overt and borderline hip dysplasia and other findings of hip instability. It is also associated with osteoarthritis in some cases and should be interpreted with caution in these patients.

Edema of the Ligamentum Teres as a Novel MRI Marker for Non-Traumatic Painful Hip Pathology: A Retrospective Observational Study

Background

The ligamentum teres has been recognized as an important stabilizer of the hip joint and can be affected by various hip pathologies. This study aims to introduce ligamentum teres edema as an MRI marker to diagnose the underlying cause of hip pathology, mainly femoral acetabular impingement (FAI) and adult developmental dysplasia of the hip (ADDH), in non-traumatic patients.

Methodology

Adult patients presenting with non-traumatic hip pain of variable duration and ligamentum teres edema on MRI between 2014 and 2020 were included. A high-resolution standard MRI hip protocol was used for all patients in this series. MRI and plain radiographs were assessed. Ligamentum teres edema, alpha angle, center edge angle of Wiberg, and retroversion were assessed.

Results

In total, 55 patients with 110 hip joints (males: 29 (52.7%), females: 26 (47.3%)) of different ethnicities were included in this study. Out of the 55 patients with ligamentum teres edema, one had only unilateral right-sided FAI, seven had only unilateral left-sided FAI, and 46 (94 hip joints) had either bilateral FAI or ADDH. Therefore, eight (14.5%) patients with unilateral FAI had the absence of the contralateral FAI or ADDH (6.5% false-positive) despite the presence of ligamentum teres edema bilaterally, and the rest of the patients with bilateral ligamentum teres edema (102 joints: 92.7% positive predictive value) had findings of either FAI or ADDH.

Conclusions

Ligamentum teres edema can be considered as an early MRI marker to diagnose the underlying pathology of symptomatic painful hip disorders, especially FAI.

Ligamentum Teres Reconstruction May Lead to Improvement in Outcomes Following a Secondary Hip Arthroscopy for Symptomatic Microinstability: A Systematic Review

PURPOSE

To present the indications, surgical technique, outcomes, and complications for patients undergoing arthroscopic reconstruction of the ligamentum teres (LT).

METHODS

Articles were included if they had postoperative patient-reported outcomes (PROs) for arthroscopic LT reconstruction. Studies were analyzed for patient demographics, clinical assessment and indications, radiographic and magnetic resonance imaging data, concomitant procedures performed, PROs, surgical techniques, intra-articular classifications, complications, and need for follow-up surgeries. For PROs, the standard mean difference was calculated. The proportion of patients achieving patient acceptable symptomatic state for postoperative modified Harris Hip Score (≥74) was recorded. The number of patients achieving minimal clinically important difference for modified Harris Hip Score (Δ ≥8) was calculated.

RESULTS

The majority of the cases were revision arthroscopies. Of the 3 studies reporting on patients undergoing LT reconstruction due to microinstability, 4, 9, and 11 patients demonstrated a mean improvement of 25.7, 35.2, and 27.7 in modified Harris Hip, respectively. In addition, one of the studies reported a mean improvement of 31.1 and 4.2 in Nonarthritic Hip Score and visual analog scale, respectively. Of the 3 studies, the percentile of patients surpassing minimal clinically important difference and patient acceptable symptomatic state ranged between 50% and 100% and 33.3% and 88.8%, respectively. Overall, 5 patients underwent revision hip arthroscopy due to adhesions, iliopsoas impingement, and persistent microinstability, and 3 patients underwent a secondary hip arthroplasty due to refractory pain and radiographic evidence of hip osteoarthritis.

CONCLUSION

Reconstruction of the LT may be considered in surgical management for patients with symptomatic hip instability due to soft-tissue causes. Current evidence supports for LT reconstruction predominantly for patients experiencing refractory instability following previous hip preservation procedures. Patients' expectations as well as the relatively high reoperation rate (i.e., 33%) should be discussed before the procedure.

LEVEL OF EVIDENCE

Level IV, systematic review of Level IV studies.

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

OBJECTIVE

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).

DESIGN

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.

RESULTS

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.

CONCLUSIONS

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.

Best Practices: Hip Femoroacetabular Impingement

OBJECTIVE. Imaging plays a critical role in the assessment of patients with femoroacetabular impingement (FAI). With better understanding of the underlying pathomechanics and advances in joint-preserving surgery, there is an increasing need to define the most appropriate imaging workup. The purpose of this article is to provide guidance on best practices for imaging of patients with FAI in light of recent advances in corrective FAI surgery. CONCLUSION. Pelvic radiography with dedicated hip projections is the basis of the diagnostic workup of patients with suspected FAI to assess arthritic changes and acetabular coverage and to screen for cam deformities. Chondrolabral lesions should be evaluated with unenhanced MRI or MR arthrography. The protocol should include a large-FOV fluid-sensitive sequence to exclude conditions that can mimic or coexist with FAI, radial imaging to accurately determine the presence of a cam deformity, and imaging of the distal femoral condyles for measurement of femoral torsion. CT remains a valuable tool for planning of complex surgical corrections. Advanced imaging, such as 3D simulation, biochemical MRI, and MR arthrography with application of leg traction, has great potential to improve surgical decision-making. Further research is needed to assess the added clinical value of these techniques.

Arthroscopic Ligamentum Teres Reconstruction: Minimum 2-Year Patient-Reported Outcomes With Subanalysis of Patients With Ehlers-Danlos Syndrome

PURPOSE

To report on minimum 2-year outcomes of patients undergoing arthroscopic ligamentum teres reconstruction (LTR).

METHODS

Our institutional registry was retrospectively reviewed for all patients undergoing LTR between December 2012 and February 2016. LTR was indicated for a fully torn or dysfunctional ligamentum teres with symptomatic multidirectional instability not treatable by osteotomy or capsular plication alone. Demographic data, preoperative clinical and radiographic measures, and intraoperative data were recorded. Patient-reported outcome measures including the modified Harris Hip Score, the Non-Arthritic Hip Score, a visual analog scale score for pain, and patient satisfaction were recorded preoperatively and annually postoperatively. Revision arthroscopies and conversions to total hip arthroplasty were recorded.

RESULTS

Twelve reconstruction procedures were performed in 10 patients during the study period. Minimum 2-year follow-up was available for 9 patients (11 hips). The mean follow-up time was 44.27 months (range, 24-72 months). There were 7 female and 2 male patients, and the mean age was 30.34 years (range, 17.23-43.68 years). Two hips underwent conversion to total hip arthroplasty at a mean of 21.12 months. For the remaining patients, significant improvements were observed in the modified Harris Hip Score (from 44.1 to 71.8), Non-Arthritic Hip Score (from 47.5 to 78.6), and visual analog scale score (from 7.8 to 3.6) (P < .05). The average patient satisfaction rating was 7.88 (range, 4-10). Subanalysis of 5 patients (7 hips) with a diagnosis of Ehlers-Danlos syndrome showed a higher failure rate in this group.

CONCLUSIONS

Although LTRs are indicated and performed only in a select group of patients, the procedure can provide meaningful improvement in patient-reported outcomes, pain reduction, and patient satisfaction. However, most patients undergoing LTR at present have underlying factors that significantly mitigate their prognosis, such as Ehlers-Danlos syndrome or failed previous surgery. Because these patients represent a subset of patients with complex hip pathologies in whom treatment is difficult, the expectations of surgery should be set accordingly.

LEVEL OF EVIDENCE

Level IV, therapeutic study, case series.

All About the Ligamentum Teres: From Biomechanical Role to Surgical Reconstruction

Intriguing anatomists and surgeons for centuries, the exact function and biomechanical significance of the ligamentum teres (LT) remains incompletely understood. The LT, also described as the ligamentum femoris capitis, is an intra-articular extrasynovial ligament extending from the cotyloid fossa of the acetabulum to the fovea on the femoral head. Some studies have described it as a vestigial structure in the adult hip. More recent biomechanical studies, however, along with histological and anatomical studies, have suggested the LT to have an important function in proprioception, nociception, and as a secondary stabilizer of the hip joint. The advent and increased utilization of hip arthroscopy to treat hip pathology over the past two decades has ignited a renewed interest in the role of the LT, as well as techniques and indications for management of pathology. In the constellation of intra-articular pain generators of the hip, LT injuries have historically been difficult to diagnose through physical examination or advanced imaging. Numerous classification systems have been proposed based on arthroscopic appearance, and for most cases, conservative management is adequate. In patients undergoing hip arthroscopy, LT débridement usually suffices, although in cases of persistent pain and severe instability, reconstruction of the ligament may be indicated. Multiple methods for reconstruction have been described, with the greatest variation in the method of acetabular fixation of the graft. Future research should focus on clarifying the role of the LT, appropriate surgical indications for reconstruction, and optimization of graft fixation within the acetabulum.

Usefulness of MR Arthrography of the Hip with and without leg Traction in Detection of Intra-articular Bodies

RATIONALE AND OBJECTIVE

Although intra-articular bodies are a classic indication for MR arthrography and surgical removal, diagnostic studies are currently sparse. To assess the diagnostic performance of MR arthrography with and without leg traction in detection of intra-articular bodies in the hip joint.

MATERIAL AND METHODS

The institutional hip arthroscopy data base (2009-2016: 631 hips) was retrospectively reviewed. Inclusion criteria were hips with and without intra-articular bodies and direct MR arthrography performed with and without leg traction. Twenty-one hips with intra-articular bodies constituted the "disease-positive" group. Seventy-nine randomly selected hips without intra-articular bodies constituted the "disease-negative" group. Images were reviewed independently for presence of intra-articular bodies by two blinded readers. Overall diagnosis and location of intra-articular bodies was recorded (peripheral or central). Arthroscopy served as goldstandard for diagnosis and location of intra-articular bodies. Diagnostic performance and kappa statistics of traction MR arthrography with and without traction were calculated.

RESULTS

For both readers sensitivity/specificity of traction MR arthrography was 86%-95% respectively 90%-91% for overall diagnosis of intra-articular bodies and was 81%-86% respectively 90%-92%for MR arthrogrpahy without traction. For central intra-articular bodies sensitivity was higher for both readers with traction (79%-89%) than without traction (74% each).

CONCLUSION

MR arthrography with and without traction of the hip is highly accurate in identifying central and peripheral intra-articular bodies. Application of traction was further useful for visualization of centrally located intra-articular bodies.