The validity and accuracy of MRI arthrogram in the assessment of painful articular disorders of the hip

Does gadolinium improve magnetic resonance arthrography of the hip beyond fluid distension alone?

AIM

To determine if there is a difference in the detection of labral tears and cartilage lesions using the T2-weighted sequences of magnetic resonance arthrography (MRA) only, which simulate MRA with saline alone, compared with the full examination including T1-weighted sequences.

MATERIALS AND METHODS

One hundred hip MRA examinations performed at 3 T were identified retrospectively. Each study was reviewed by a musculoskeletal radiologist using either the T2-weighted sequences only (without gadolinium-based contrast agent [GBCA] effect) or the entire examination, including T1-weighted sequences (with GBCA effect). Receiver operating characteristic (ROC) curves were calculated for both groups and compared within a non-inferiority framework, using - 0.10 as the limit of non-inferiority.

RESULTS

For labral tears, the difference area under the curve (AUC) was -0.004 (95% confidence interval [CI]: -0.064-0.056, p=0.90). For acetabular cartilage lesions, the difference AUC was 0.011 (95% CI: -0.073-0.096, p=0.79). For femoral cartilage lesions, the difference AUC was -0.059 (95% CI: -0.206-0.087, p=0.43).

CONCLUSION

T2-weighted sequences alone were not inferior in diagnostic accuracy compared with the full examination (including T1-weighted sequences with intra-articular GBCA) in detecting acetabular cartilage lesions and labral tears. Further study with prospective comparison of saline injectate to GBCA-containing injectate may help clarify the necessity of continued GBCA use in MRA of the hip.

Image quality of hip MR arthrography with intra-articular injection of hyaluronic acid versus gadolinium-based contrast agent in patients with femoroacetabular impingement

OBJECTIVE

To compare image quality of magnetic resonance arthrography (MRA) of the hip with intra-articular injection of high-viscosity hyaluronic acid (HA-MRA) versus Gd-based contrast agent (Gd-MRA) in patients with femoroacetabular impingement (FAI).

MATERIALS AND METHODS

Design: single-centre, observational, retrospective, inter-individual, and cross-sectional. FAI patients who underwent HA-MRA (3 mL of high-viscosity HA plus 17 mL of saline) were compared with 37 age- and sex-matched FAI patients who underwent Gd-MRA (20 mL of 2 mmol/L solution of gadopentetate dimeglumine). Two independent blinded radiologists assessed image quality for all sequences (two-dimensional proton density, non-fat-sat axial, fat-sat coronal and sagittal; three-dimensional dual-echo steady state), using a 5-point Likert scale considering separately labrum, cartilage, round ligament, transverse ligament, and capsule. Pearson χ² and Cohen κ were used.

RESULTS

The HA-MRA group was composed of 37 patients (23 males, 14 females; median age 38 years), the Gd-MRA group of 37 patients (21 males, 16 females; median age 38 years), without significant difference for age (p = 0.937) and sex (p = 0.636). Image quality did not differ between the two readers for any structure: labrum (p ≥ 0.340), cartilage (p ≥ 0.198), round ligament (p ≥ 0.255), transverse ligament (p ≥ 0.806), and capsule (p ≥ 0.314). Inter-reader agreement (κ) ranged from 0.785 to 1.000.

CONCLUSIONS

HA-MRA provided an image quality not significantly different from that of Gd-MRA. This may open the possibility of combining MRA and viscosupplementation in one single procedure.

Single-Stage Arthroscopic Autologous Matrix-Enhanced Chondral Transplantation (AMECT) in the Hip

Chondral defects of the acetabulum in patients with femoroacetabular impingement syndrome are an increasingly recognized cause of worse outcomes after treatment. Multiple procedures have been described for the treatment of hip cartilage lesions including microfracture, autologous chondrocyte implantation, matrix-induced autologous chondrocyte implantation, and autograft and allograft transplantation. However, many of these techniques have poor long-term outcomes, require multiple surgical procedures, or rely on planned preoperative identification of the chondral lesion. This Technical Note describes our technique of autologous matrix-enhanced chondral transplantation, a single-stage treatment for acetabular cartilage lesions that harvests chondral tissue from the femoral cam deformity and combines it with chondral extracellular matrix, growth factors, and autologous peripheral blood.

The Rapidly Assessed Predictor of Intraoperative Damage (RAPID) Score: An In-Clinic Predictive Model for High-Grade Acetabular Chondrolabral Disruption

Background

The preoperative assessment of cartilage lesions is critical to surgical planning and decision making. The accurate radiographic determination of acetabular cartilage damage has remained elusive for modern imaging modalities, including magnetic resonance imaging (MRI) and magnetic resonance arthrography (MRA). While risk factors have been individually described, no multivariable system exists for predicting high-grade cartilage damage.

Purpose

To determine the preoperative predictors of grade 3 to 4 acetabular labrum articular disruption (ALAD) lesions.

Study Design

Case-control study; Level of evidence, 3. Cohort study (diagnosis); Level of evidence, 1.

Methods

Retrievable radiographs were reviewed from primary hip arthroscopic procedures performed at 2 high-volume institutions between December 2007 and April 2017. The predictive value of demographic and radiographic factors for the intraoperative documentation of ALAD grade 3 to 4 damage was analyzed and entered into a multivariable model, and a statistically guided scoring system for the damage risk was created using the Akaike information criterion. The scoring system was then prospectively validated on 167 patients who underwent primary hip arthroscopy between April 2017 and February 2018.

Results

A total of 652 primary hip arthroscopic procedures in 614 patients (390 female, 224 male; mean age, 33.2 ± 12.5 years; mean body mass index, 26.9 ± 5.5 kg/m²) from 2007 to 2017 were analyzed. Male sex (odds ratio [OR], 3.11; P < .01), age ≥35 years (OR, 1.96; P < .01), cam morphology (alpha angle >55°) (OR, 2.96; P < .01), and Tönnis grade 1 to 2 (grade 1: OR, 4.14; P < .01, and grade 2: OR, 9.29; P < .01) were univariate risk factors for intraoperatively documented high-grade damage. A multivariable scoring system, the Rapidly Assessed Predictor of Intraoperative Damage (RAPID) score (0-5 points), was generated based on sex, Tönnis grade, and cam morphology. Patients with increasing RAPID scores had an increasing risk of damage, with a 10.5% risk for those with 0 points and an 88.0% risk for those with 5 points (P < .01). The area under the curve was 0.75 for the study group and 0.76 for the validation group (P = .94).

Conclusion

While preoperative MRI has diagnostic value for hip arthroscopic surgery, the RAPID score provides added benefit as a readily employable, in-clinic system for predicting high-grade cartilage damage. The discriminatory value of the RAPID score compares favorably with previous MRI and MRA studies. This information will help the clinician and patient plan for high-grade damage and identify potential targets for cartilage treatment.