MR Imaging of SLAP Lesions

An assessment of SLAP type 5 lesions using proton density oblique sagittal imaging in magnetic resonance arthrography

BACKGROUND

Bankart lesions accompany superior labrum anteroposterior (SLAP) lesions; these are called SLAP type 5.

PURPOSE

To compare SLAP type 5 lesions using routine magnetic resonance arthrography (MRA) and thin-slice oblique sagittal proton density (PDW) sequences and correlation operation results.

MATERIAL AND METHODS

In total, 181 patients were admitted with shoulder instability. The study was completed with 44 patients. The presence or absence of isolated Bankart and SLAP type 5 lesions in routine MRA and PDW oblique sagittal images were evaluated separately. Absence of rupture scored 0 points, suspected ruptures scored 1 point, and apparent ruptures scored 2 points. The two scores were compared with the shoulder arthroscopy findings.

RESULTS

According to the findings in the shoulder arthroscopy, 40 patients had Bankart lesions and 17 patients had accompanying SLAP type 5 lesions. To detect a Bankart lesion, there was no significant difference between routine MRA sequences and PDW oblique sagittal images (P = 0.061). Routine MRA sensitivity was 95%, specificity 25%, positive predictive value (PPV) 92%, negative predictive value (NPV) 33%, while for PDW oblique sagittal images, sensitivity was 75%, specificity 100%, PPV 100%, and NPV 28.5%. In 8/17 type 5 SLAP lesions, routine MRA detected sensitivity 47%, specificity 92.6%, PPV 80%, and NPV 73.5%; in 14/17 SLAP type 5 lesions, PDW oblique sagittal images detected sensitivity 82%, specificity 100%, PPV 100%, and NPV 90% (P = 0.015).

CONCLUSION

The PDW oblique sagittal images may play a significant role in assessing the anterior and superior extent of the tears.

Progression of long head of the biceps brachii tendon abnormality on magnetic resonance imaging after rotator cuff repair

OBJECTIVES

To correlate the deterioration of preserved long head of biceps tendon (LHB) after rotator cuff repair with preoperative and postoperative MRI factors.

METHODS

Total of 209 shoulder joints (F:M = 145:64; mean age 57.4 years) which underwent rotator cuff repair and at least two postoperative MRI scans over 10 months after surgery were included. LHB integrity was graded with a five point severity scale. LHB deterioration was defined by increased composite score of integrity and extent score between the preoperative and second postoperative MRI. For preoperative and postoperative MRI factors, size and location of superior cuff -supraspinatus and infraspinatus- and subscapularis tears, fatty degeneration of rotator cuff, preoperative LHB status, subluxation of LHB, superior labral tear, acromion type, repaired rotator cuff status, postoperative capsulitis and acromioplasty state were assessed. Logistic regression was used to evaluate the association between LHB deterioration and aforementioned factors. Same analysis was conducted for 62 shoulder joints with a long-term follow-up MRI.

RESULTS

Of the 209 shoulders, 49.3% (n = 103) showed LHB deterioration on short-term follow-up MRI. In long-term follow-up subgroup, 32 LHBs were further deteriorated. In multivariate analysis, fatty degeneration of superior cuff showed significant association with LHB deterioration in both short-term (p = .04, p = .007) and long-term subgroups (p = .004, p = .005) among preoperative and postoperative factors, respectively.

CONCLUSIONS

Degree of fatty degeneration in superior cuff is associated with LHB deterioration on postoperative MRI.

ADVANCES IN KNOWLEDGE

Our results support that tenotomy or tenodesis of LHB should be considered during rotator cuff repair, especially in patients with advanced fatty degeneration of rotator cuff.

Postoperative Knee and Shoulder

Arthroscopic surgery in the knee most commonly addresses ligament, meniscal, or articular cartilage abnormalities. Similarly, arthroscopic surgery of the shoulder most commonly addresses tendon and labral abnormalities. The expected postoperative MRI findings depend on both the procedure performed and the time since surgery. Identifying complications and failed procedures relies on both clinical and imaging evaluations.

Magnetic resonance imaging of the shoulder

The aim of this article is to review the use of magnetic resonance imaging (MRI) for the evaluation of shoulder pain, which is a common clinical complaint of the musculoskeletal system. MRI is an essential auxiliary tool to evaluate these patients because of its high resolution and high sensitivity in depicting the soft tissues. This article will review the imaging technique, normal imaging anatomy, and most common imaging findings of disorders of tendons, labrum, and ligaments of the shoulder. It will also discuss common systemic diseases that manifest in the shoulder as well as disorders of the acromioclavicular joint and bursae. New advances and research in MRI have provided additional potential uses for evaluating shoulder derangements.

Diagnostic performance of 3D-multi-Echo-data-image-combination (MEDIC) for evaluating SLAP lesions of the shoulder

Background

Superior labral anterior to posterior (SLAP) lesions remain a clinical and diagnostic challenge in routine (non-arthrographic) MR examinations of the shoulder. This study prospectively evaluated the ability of 3D-Multi-Echo-Data-Image-Combination (MEDIC) compared to that of routine high resolution 2D-proton-density weighted fat-saturated (PD fs) sequence using 3 T-MRI to detect SLAP lesions using arthroscopy as gold standard.

Methods

Seventeen consecutive patients (mean age, 51.6 ± 14.8 years, 11 males) with shoulder pain underwent 3 T MRI including 3D-MEDIC and 2D-PD fs followed by arthroscopy. The presence or absence of SLAP lesions was evaluated using both sequences by two independent raters with 4 and 14 years of experience in musculoskeletal MRI, respectively. During arthroscopy, SLAP lesions were classified according to Snyder’s criteria by two certified orthopedic shoulder surgeons. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 3D-MEDIC and 2D-PD fs for detection of SLAP lesions were calculated with reference to arthroscopy as a gold standard. Interreader agreement and sequence correlation were analyzed using Cohen’s kappa coefficient.

Figure 1 demonstrates the excellent visibility of a proven SLAP lesion using the 3D-MEDIC and Fig. 2 demonstrates a false-positive case.

Results

Arthroscopy revealed SLAP lesions in 11/17 patients. Using 3D-MEDIC, SLAP lesions were diagnosed in 14/17 patients by reader 1 and in 13/17 patients by reader 2. Using 2D-PD fs, SLAP lesions were diagnosed in 11/17 patients by reader 1 and 12/17 patients for reader 2. Sensitivity, specificity, PPV, and NPV of 3D-MEDIC were 100.0, 50.0, 78.6, and 100.0% for reader 1; and 100.0, 66.7, 84.6, and 100% for reader 2, respectively. Sensitivity, specificity, PPV, and NPV of 2D-PD fs were 90.9, 83.3, 90.9, and 83.3% for reader 1 and 100.0, 83.3, 91.7, and 100.0% for reader 2. The combination of 2D-PD fs and 3D-MEDIC increased specificity from 50.0 to 83.3% for reader 1 and from 66.7 to 100.0% for reader 2. Interreader agreement was almost perfect with a Cohen’s kappa of 0.82 for 3D-MEDIC and 0.87 for PD fs.

Conclusions

With its high sensitivity and NPV, 3D-MEDIC is a valuable tool for the evaluation of SLAP lesions. As the combination with routine 2D-PD fs further increases specificity, we recommend incorporation of 3D-MEDIC as an additional sequence in conventional shoulder protocols in patients with non-specific shoulder pain.