SLAP lesions: anatomy, clinical presentation, MR imaging diagnosis and characterization

Superior labral anterior posterior (SLAP) tears are an abnormality of the superior labrum usually centered on the attachment of the long head of the biceps tendon. Tears are commonly caused by repetitive overhead motion or fall on an outstretched arm. SLAP lesions can lead to shoulder pain and instability. Clinical diagnosis is difficult thus imaging plays a key diagnostic role. The normal anatomic variability of the capsulolabral complex can make SLAP lesions a diagnostic challenge. Concurrent shoulder injuries are often present including rotator cuff tears, cystic changes or marrow edema in the humeral head, capsular laxity, Hill-Sachs or Bankart lesion. The relevant anatomy, capsulolabral anatomic variants, primary and secondary findings of SLAP tears including MR arthrography findings, types of SLAP lesions and a practical approach to labral lesions are reviewed.     

One-shot MR and MDCT arthrography of shoulder lesions with arthroscopic correlation

Although MR imaging and MR arthrography are the first choice modalities for shoulder imaging, CT arthrography (CTA) may be used successfully to address many clinical questions. The advent of sub-millimeter multiple detector CT (MDCT) technology and subsequent excellent three-plane resolution has considerably increased the quality of CTA examinations and has propelled this technique to the forefront in a growing number of indications.     

Cartilage lesions of the glenohumeral joint: diagnostic effectiveness of multidetector spiral CT arthrography and comparison with arthroscopy

This study assessed the diagnostic effectiveness of multidetector spiral CT arthrography (MDCTa) in detecting hyaline cartilage abnormalities of the shoulder joint, with correlation to arthroscopy. Shoulder MDCTa images prospectively obtained in 22 consecutive patients (mean age, 50 years; age range, 23–74 years; 12 female, 10 male) were evaluated for glenohumeral cartilage lesions. Two musculoskeletal radiologists independently analysed the cartilage surfaces of the humeral head and of the glenoid fossa in nine anatomical surface areas. Observations of MDCTa were compared to arthroscopic findings. The sensitivity and specificity of MDCTa for grade 2 (substance loss <50%) or higher and grade 3 (substance loss ≥50%) or higher cartilage lesions, the Spearman correlation coefficient between arthrographic and arthroscopic grading, and K statistics for assessing Intra and Interobserver reproducibility were determined. At MDCTa, sensitivities and specificities ranged between 80% and 94% for the detection of grade 2 or higher cartilage lesions, and between 88% and 98% for the detection of grade 3 or higher cartilage lesions. Spearman correlation coefficients between MDCTa and arthroscopic grading of articular surfaces ranged between 0.532 and 0.651. Interobserver agreement was moderate for grading all articular surfaces (κ = 0.457), but substantial to almost perfect for detecting lesions with substance loss (κ, 0.618–0.876). In conclusion, MDCTa is accurate for the study of cartilage surface in the entire shoulder joint. This technique may beneficially impact patient’s management by means of selecting the proper treatment approach.     

Capsular lesions with glenohumeral ligament injuries in patients with primary shoulder dislocation: magnetic resonance imaging and magnetic resonance arthrography evaluation

The glenohumeral ligaments are important structures for the stability of the shoulder. They are integrated parts of the capsule and are at risk to be injured in a traumatic shoulder dislocation. The aim was to examine the prevalence of capsular ligament lesions in the acute phase and at minimum 3 weeks' follow-up after first-time traumatic shoulder dislocation. Forty-two patients aged 16-40 years were included. All patients underwent computed tomography and magnetic resonance imaging (MRI) scans shortly after the injury and MR-arthrography (MRA) at follow-up. The median time from dislocation to MRI was 7 (range 2-14) days and to MRA 30 (range 21-54) days. We found capsular ligament lesions in 22 patients (52.4%) in the acute stage and in five patients (11.9%) at follow up. Nine patients (21.4%) had a humeral avulsion of the anterior glenohumeral ligament (HAGL lesion) on MRI. Three patients (7.1%) had this lesion at follow-up. The rate of HAGL lesions in the acute stage was higher than reported previously, but the prevalence at follow-up was in keeping with earlier published studies.     

Adhesive capsulitis of the shoulder: diagnosis using magnetic resonance arthrography, with arthroscopic findings as the standard

OBJECTIVE: The purpose of this study was to assess the usefulness of magnetic resonance (MR) arthrography of the glenohumeral joint in the diagnosis of adhesive capsulitis. METHODS: MR arthrography of the glenohumeral joint was performed in 16 patients with arthroscopically proven adhesive capsulitis and 11 controls. Thickness of the joint capsule and synovium, filling ratio of the fluid-distended axillary recess to the posterior joint cavity, and a width of the rotator cuff interval were measured by 2 musculoskeletal radiologists. The measurements of those parameters for the patients with adhesive capsulitis and the controls were compared. Interobserver variability for the measurements of each parameter was calculated. RESULTS: The mean thickness of the joint capsule and synovium was 2.97 mm in patients with adhesive capsulitis and 1.86 mm in controls (P < 0.001). The mean filling ratio of the fluid-distended axillary to the posterior joint cavity was 0.51 in patients with adhesive capsulitis and 0.82 in controls (P = 0.004). The mean width of the rotator cuff interval was 7.45 mm in patients with adhesive capsulitis and 8.48 mm in controls (P > 0.05). Intraclass correlation coefficient for interobserver variability showed good agreement (95% CI; 0.72-0.95). CONCLUSIONS: On MR arthrography, thickening of the joint capsule and synovium and diminished filling ratio of the axillary recess to posterior joint cavity appeared to be useful diagnostic criteria for the diagnosis of adhesive capsulitis of the shoulder.     

Three-dimensional spin-lock magnetic resonance imaging of the shoulder joint at 3 T: initial experience

Objectives This was a pilot study which aimed to assess the feasibility of 3D-spin-lock (3D-T_1ρ) MRI of the shoulder joint and to establish baseline values of healthy humeral and glenoid cartilages in vivo. Material and methods Four asymptomatic volunteers [mean age 31 years (range 29–36 years)] were recruited. A 3.0 T scanner, employing a four-channel, phased-array, shoulder, radio-frequency (RF) coil was used. Three-dimensional T_1ρ-weighted images were acquired with a 3D gradient-echo (GRE) sequence with T_1ρ magnetization preparation. In order to a construct T_1ρ map, we acquired four 3D-T_1ρ-weighted images with spin-locking length (TSL) values of 2 ms, 10 ms, 20 ms, and 30 ms. The glenoid and humeral cartilage were segmented manually at each slice of the 3D images. We performed additional regional analysis by dividing the cartilage into anterior/posterior and superior/inferior regions. Results The global average T_1ρ value of the shoulder cartilages varied from 37.9 ms to 48.5 ms and from 32.4 ms to 36.9 ms for humeral and glenoid cartilages, respectively. In the humeral cartilage, the average regional T_1ρ values varied from 35.9 ms to 52.2 ms; 54.4 ms to 69.0 ms; 39.1 ms to 49.3 ms and 34.6 ms to 57.2 ms for the anterior–superior, anterior–inferior , posterior–superior and posterior–inferior regions, respectively. In the glenoid cartilage, the values varied from 31.3 ms to 40.8 ms; 34.1 ms to 35.3 ms; 26.7 ms to 37.2 ms and 32.8 ms to 35.7 ms for the same regions, respectively. Conclusion We demonstrated that 3D-T_1ρ MRI of the shoulder can be performed on a 3 T clinical scanner within specific absorption rate (SAR) limits, and we present baseline values for healthy patients which may be useful for quantitative comparison with diseased shoulders.     

Low-field MR arthrography of the shoulder joint: technique,indications, and clinical results

In the age of cost containment and urgent reductions in health care expenditures, new options have to be explored to satisfy both diagnostic requirements and economic limitations. The introduction of low-field MR systems for assessment of joint disorders seemed to be an option for lower costs. The purpose of this article is to summarize available experiences with low-field MR arthrography of the glenohumeral joint with respect to image quality and diagnostic accuracy in detecting labral and rotator cuff lesions. Up to now, there has been only a limited number of studies available dealing with low-field MR arthrography of the glenohumeral joint. They reveal that, despite a minor image quality in comparison with high-field imaging, low-field MR arthrography of the shoulder allows for sufficient evaluation of intra- and extra-articular structures in the detection of major abnormalities such as glenohumeral instability or rotator cuff disease. Furthermore, open-configured MR scanners enable kinematic studies: Besides the analysis of normal motion, pathological findings in patients with instabilities and impingement syndrome can be delineated. They further offer the possibility for performing MR imaging-guided arthrography of the shoulder. This was first described using an open C-arm scanner with a vertically oriented magnetic field so that MR arthrography may be performed in one setting. Electronic Publication     

An arthroscopic and electromyographic study of painful shoulders in elite gymnasts

Shoulder problems are common in overhead sports like baseball, basketball and volleyball. Although gymnastics also includes overhead activities, there are few reports about shoulder problems in this sports activity. During the time period 1992–1995 we treated five young competitive gymnasts for shoulder pain. Arthroscopy revealed that they were all suffering from SLAP lesions or other labral pathology, although they had never dislocated their shoulders. These injuries have not been described earlier in connection with gymnastics. In a survey of 13 gymnasts in an elite club, we found that six (46%) complained about shoulder pain. Since four of these athletes explained that their shoulder pain started acutely during ring exercises in suspension while one suffered a slower onset with pain also during parallel bar exercises, we undertook an electromyographic study of the shoulder musculature of three normal elite gymnasts during exercises on the parallel bars and rings. We found that during the ring exercises in suspension there was a critical phase during which the muscle activity around the shoulder was very low, leading to great articular stresses. This might explain the occurrence of labral lesions like the SLAP lesions in this type of athlete. If shoulder pain in elite gymnasts does not respond to rest and physical therapy over 2–3 months, a shoulder arthroscopy should be considered.     

Assessment of the long head of the biceps tendon of the shoulder with 3T magnetic resonance arthrography and CT arthrography

We studied the assessment of proximal biceps tendon lesions including degeneration, tendon luxation, and partial and complete tendon tears with 3T MR arthrography and CT arthrography. Thirty-six patients who underwent both studies, as well as arthroscopy were included in the study. The images were randomized and blinded and independently reviewed by two musculoskeletal radiologists. The pooled sensitivity for lesion detection for CT arthrography was 31% and the specificity 95%. The pooled sensitivity for MR arthrography was 27% and the specificity 94%. There were no statistically significant differences between CT and MR. The interobserver agreement calculated with the kappa statistic was poor for CT and for MR. Both CT arthrography and MR arthrography perform poorly in the detection of biceps tendon pathology of the shoulder.     

Frequency of glenoid chondral lesions on MR arthrography in patients with anterior shoulder instability

Purpose

To describe the frequency of glenoid chondral abnormalities in relation to Hill Sachs (HS) lesions in MR arthrograms of patients with anterior shoulder instability versus controls. Such glenoid lesions can directly impact surgical decision-making and approach, and potentially negatively impact outcome if missed.

Materials and methods

Retrospective analysis of direct MR shoulder arthrograms in 165 subjects, (101 with anterior instability/64 controls) was performed independently by 2 blinded musculoskeletal radiologists. Outcome measures were the presence of a HS, anterior labral pathology and glenoid chondral injury. Kappa statistic, Pearson Chi-square and Mann–Whitney analysis were employed for analysis.

Results

Inter-observer variability for the presence of HS, labral and chondral lesions was 0.964, 0.965 and 0.858 respectively, with intra-observer variability of 1.0, 0.985 and 0.861 for the principle reader. 58% of patients and 8% of controls had HS (p < 0.001). 72% of patients and 25% of controls had anterior labral injury (p < 0.001).36% of instability patients and 10% controls had glenoid chondral lesions (p < 0.001). 46% of anterior instability patients with HS defects had chondral injury as opposed to 21% of patients without HS defects (p = 0.009). Depth of the HS lesion did not increase the likelihood of a glenoid chondral lesion (p = 0.7335).

Conclusion

In the clinical anterior instability cohort, we demonstrated a statistically significant higher number of HS and glenoid chondral lesions than in controls. In anterior instability patients, the presence of a HS lesion confers a statistically significant greater likelihood of having a glenoid chondral lesion when compared to patients with instability and no HS.     

The surgical outcome of immediate arthroscopic Bankart repair for first time anterior shoulder dislocation in young active patients

This study evaluated the surgical outcomes of young active patients with arthroscopic Bankart repair within 1 month after first-time anterior shoulder dislocation. From July 2002–October 2004, patients presented with first-time traumatic anterior shoulder dislocation and treated with arthroscopic stabilization within 1 month of injury were retrospectively reviewed. Magnetic resonance imaging and computed tomography were performed before the operation in all cases. Cases with contralateral shoulder multidirectional instability or glenoid bone loss of more than 30% on preoperative computed tomography on the injury side were excluded. All patients were treated with arthroscopic Bankart repair, using metallic suture anchors or soft tissue bio-absorbable anchors by a same group of surgeons and followed the same rehabilitation protocol. Recurrence, instability signs, range of motion, WOSI score, Rowe score and complications were assessed. Thirty-eight patients were recruited: the average age was 21 (16–30). All patients had definite trauma history. Radiologically, all patients had Bankart/Hill-Sachs lesion. All the operations were done within 1 month after injury (6–25 days). The average hospital stay was 1.2 days (1–5 days). The average follow-up was 28 months (24–48 months). There were two cases of posttraumatic re-dislocation (5.2%). The average external rotation lag was 5° (0–15) in 90° shoulder abduction when compared with contralateral side. 95% of patients had excellent or good Rowe score. The average WOSI score was 83%. There was one case of transient ulnar nerve palsy and one case of superficial wound infection. This study concluded that immediate arthroscopic Bankart repair with an accelerated rehabilitation program is an effective and safe technique for treating young active patients with first-time traumatic anterior shoulder dislocation. This study complies with the current laws of the Hong Kong Special Administration Region Government.     

Primary synovial chondromatosis of the shoulder: clinical, arthroscopic and histopathological aspects

Primary synovial chondromatosis is an uncommon condition, and involvement of the glenohumeral joint is rare. Currently, the recommended treatment is arthroscope-assisted synovectomy and removal of the loose bodies. We report a case with the clinical findings, radiographic features, arthroscopic technique for treatment of this disease and the main histological appearance of the removed loose bodies. We believe this is an easy and safe method for management of this disorder and that the support of an experienced pathologist is necessary to avoid differential diagnostic problems with the uncommon malignant transformation.     

关节镜下肩袖损伤修补术后早期运动和制动对肩关节功能的影响

目的 探讨早期康复被动运动和制动对关节镜下肩袖损伤修补术后肩关节功能的影响.方法 采用回顾性病例对照研究分析2016年1月至2017年12月上海交通大学医学院附属新华医院收治的78例肩袖损伤患者临床资料,其中男36例,女42例;年龄35～78岁[(62.7 ±3.2)岁].中度撕裂(1～3 cm)36例,小撕裂(<1 ...     

Imaging findings in the dominant shoulder of throwing athletes: comparison of radiography, arthrography, CT arthrography, and MR arthrography with arthroscopic correlation

OBJECTIVE: Conventional radiography, arthrography, CT arthrography, and MR arthrography--including use of the abduction and external rotation position--were compared, with arthroscopic correlation, to determine the spectrum of abnormalities encountered and the relative benefits of each imaging method in the evaluation of shoulder lesions occurring in 17 throwing athletes. SUBJECTS AND METHODS: Each of 36 athletes with shoulder pain aggravated by abduction and external rotation was examined in a single visit during which conventional radiography, arthrography, CT arthrography, and MR arthrography were performed. In 17 of these athletes, imaging findings were compared with those at arthroscopy. All images were independently evaluated by two groups of musculoskeletal radiologists. RESULTS: Structures found to be affected were, in decreasing order of frequency, the following: the posterosuperior labrum, supraspinatus tendon, infraspinatus tendon, humeral head, glenoid cavity and rim, acromioclavicular joint, anteroinferior capsulolabral complex, biceps tendon, and subscapularis tendon. MR arthrography without and with abduction and external rotation yielded the highest sensitivity and specificity for all lesions with the exceptions of bone sclerosis and enthesophytes (which were best seen with CT arthrography). MR arthrography with abduction and external rotation was most accurate for diagnosis of rotator cuff and anteroinferior capsulolabral complex tears. CONCLUSION: On the basis of these preliminary results, we believe that MR arthrography with abduction and external rotation should be part of the imaging evaluation of shoulder pain in throwing athletes, owing to the high sensitivity of this imaging technique.     

Magnetic resonance imaging of the shoulder: rationale and current applications

Because it can demonstrate a wide range of tissue contrast with excellent resolution, magnetic resonance (MR) imaging has revolutionized imaging in many areas of the musculoskeletal system and has generated excitement among those interested in the painful shoulder. Shoulder impingement syndrome and glenohumeral instability constitute the two major categories of shoulder derangements. Correct diagnosis requires the use of appropriate pulse sequences and imaging planes, proper patient positioning, and a satisfactory surface coil. In addition the imager must have a thorough understanding of shoulder anatomy and pathology. We present a summary of the current status of MR imaging of the shoulder including technical, anatomic, and pathologic considerations and a review of the pertinent literature.     

The relationship of superior labralanteroposterior (SLAP) lesions and pseudolaxity to shoulder injuries in the overhead athlete

Understanding the effect of superior labral lesions on the function of the shoulder is essential to successfullytreating the overhead athlete. Recognizing the pseudolaxity owing to superior labral anteroposterior (SLAP) lesions and the pathological "peel-back" sign is critical in evaluating the injured shoulder in general and repairing the SLAP lesion in particular. The mechanical characteristics of suture anchors are more favorable than tacks in resisting the pathological forces responsible for the peel-back mechanism. The higher success rate of arthroscopic suture anchor repair of SLAP lesions in comparison with open capsulolabral reconstruction suggests that SLAP lesions are the usual cause of the "dead arm" syndrome. In our experience, arthroscopic repair of SLAP lesions can return the overhead athlete to their preoperative level of function in the vast majority of cases (87% return to preoperative level for two or more seasons).