Frozen Shoulder: MR Arthrographic Findings

Capsular Injury and Inflammation

The capsular and ligamentous structures of the glenohumeral joint are important for stability of the shoulder. These structures are best evaluated by MR imaging. Familiarity with normal and abnormal appearance of the capsular structures of the shoulder is important to ensure that important pathology is not overlooked. Injury to the capsular structures can occur in the setting of trauma and most commonly involves the inferior glenohumeral ligament and axillary pouch. Adhesive capsulitis is a common inflammatory condition with characteristic imaging features that should be considered in the absence of alternative diagnoses.

Increased Stiffness of Rotator Cuff Tendons in Frozen Shoulder on Shear Wave Elastography

OBJECTIVES

To evaluate the stiffness and morphologic characteristics of the capsule, rotator cuff tendons and muscles, coracohumeral ligament (CHL), and long head of the biceps in patients with frozen shoulder using shear wave elastography (SWE) with B-mode ultrasound.

METHODS

Thirty-two patients with frozen shoulder were divided into freezing and frozen phases. All patients had limitations of their range of motion without rotator cuff tears. Stiffness was measured by SWE in the supraspinatus (SSp) tendon, infraspinatus (ISp) tendon, SSp muscle, ISp muscle, teres minor muscle, upper and lower trapezius muscles, posterior capsule, CHL, and long head of the biceps. The posterior capsule and CHL thicknesses were also investigated with B-mode ultrasound. All values were compared in the affected and unaffected shoulders in each phase.

RESULTS

The SWE values for the SSp and ISp tendons in the freezing phase and the CHL in the frozen phase were significantly greater on the affected side than the unaffected side (mean ± SD, 280.4 ± 125.3 versus 178.1 ± 73.3, 318.4 ± 110.7 versus 240.8 ± 91.5, and 287.2 ± 135.3 versus 214.1 ± 91.1 kPa, respectively; P < .05). The posterior capsule in both the freezing and frozen phases and the CHL in the frozen phase were significantly thicker on the affected side than the unaffected side (1.3 ± 0.2 versus 0.9 ± 0.3, 1.2 ± 0.4 versus 0.9 ± 0.3, and 4.4 ± 1.4 versus 3.3 ± 1.1 mm; P < .01).

CONCLUSIONS

The SWE values of the both SSp and ISp tendons increased in the freezing phase, and that of the CHL also increased in the frozen phase. Not only the change in thickness of the capsule but also the change in stiffness of the rotator cuff may correlate with frozen shoulder.

Glossary of terms for musculoskeletal radiology

Members of the International Skeletal Society compiled a glossary of terms for musculoskeletal radiology. The authors also represent national radiology or pathology societies in Asia, Australia, Europe, and the USA. We provide brief descriptions of musculoskeletal structures, disease processes, and syndromes and address their imaging features. Given the abundance of musculoskeletal disorders and derangements, we chose to omit most terms relating to neoplasm, spine, intervention, and pediatrics. Consensus agreement was obtained from 19 musculoskeletal radiology societies worldwide.

The effect of concomitant coracohumeral ligament release in arthroscopic rotator cuff repair to prevent postoperative stiffness: a retrospective comparative study

PURPOSE

This study was to evaluate the efficacy and safety of coracohumeral ligament (CHL) release from the coracoid process concomitant with arthroscopic rotator cuff repair for preventing postoperative stiffness.

METHODS

Data on patients who underwent arthroscopic rotator cuff repair with a minimum follow-up of 1 year were collected retrospectively. Propensity score matching (1-to-1) was performed between a no-releasing group (Group I) and CHL-releasing group (Group II). In total, 76 patients in each group were matched. Clinical outcomes were assessed and compared between the two groups, including range of motion (ROM) and visual analogue scale for pain (pVAS) at postoperative 3 months, 6 months, and 1 year. The integrity of the repaired tendon was assessed at 1-year follow-up using either magnetic resonance imaging or ultrasonography.

RESULTS

External rotation (ER) at side at postoperative 3 months in Group II was better than that in Group I (48.6° ± 11.6° vs. 38.4° ± 13.0°, P < 0.001). When evaluating only patients with a small-to-medium sized tear at postoperative 3 months, ER at side was 49.8° ± 10.9° in Group II versus 37.8° ± 13.1° in Group I (P < 0.001). In patients with a large-to-massive sized tear, however, there was no significant difference in ER at side at postoperative 3 months (n.s.). There was no significant difference in ROM and functional scores at postoperative 6 months and 1 year, and there was no significant difference in healing failure rate (6 cases in Group I (7.9%), 2 cases in Group II (2.6%); n.s.). No complications of the CHL release procedure occurred.

CONCLUSIONS

In arthroscopic rotator cuff repair, CHL release from the coracoid process without creating a rotator interval defect could be an effective and safe method to prevent early postoperative stiffness, especially ER at side in patients with a small-to-medium sized tear. Therefore, CHL release can be used as a selective procedure to prevent postoperative stiffness in patients that may benefit from this procedure with decreased preoperative ER compared to the normal side.

LEVEL OF EVIDENCE

Level III.

Shoulder adhesive capsulitis: diagnostic value of active and passive range of motion with volume of gleno-humeral capsule as a reference

BACKGROUND

The diagnosis of adhesive capsulitis is currently based on restricted range of motion (ROM) but its diagnostic value has only been rarely investigated.

AIM

The aim of this study is to assess the diagnostic value of active global and passive gleno-humeral ROM to diagnose shoulder adhesive capsulitis.

DESIGN

Cross-sectional descriptive study.

SETTING

One French center for Rehabilitation Medicine.

POPULATION

Patients referred for treatment of shoulder adhesive capsulitis in our center were included. Inclusion criteria were: shoulder pain; limitation of active global ROM (abduction or flexion <180°); limitation of passive gleno-humeral ROM (abduction or flexion <90° or 25% reduction at less of lateral rotation versus the opposite shoulder); no gleno-humeral arthropathy on radiography.

METHODS

The volume of the gleno-humeral capsule was assessed during a procedure of arthro-distension. The reference criterion for adhesive capsulitis was a volume <12 mL. We analyzed the correlation between the parameters of mobility and the volume of the gleno-humeral capsule; and the positive predictive value (PPV) of inclusion criteria, with the reference criterion for the diagnosis of adhesive capsulitis.

RESULTS

We included 38 patients. Passive gleno-humeral ROM in abduction only was correlated with volume of the gleno-humeral capsule: r=0.33, P=0.043. The PPV of inclusion criteria was 82% for the diagnosis of shoulder adhesive capsulitis. Rather than 90°, when we considered 80°, 60° and 40° as the threshold of passive gleno-humeral ROM in abduction, the PPV increased from 83% to 100%.

CONCLUSIONS

Passive gleno-humeral ROM in abduction is correlated with volume of the gleno-humeral capsule. The PPV is high for active global and passive gleno-humeral ROM for diagnosis of shoulder adhesive capsulitis.

CLINICAL REHABILITATION IMPACT

Limitation of active and passive shoulder ROM, especially passive abduction gleno-humeral, is a good criterion to diagnose shoulder adhesive capsulitis, in patients with shoulder pain and no gleno-humeral arthropathy on radiography.

Does arthroscopic preemptive extensive rotator interval release reduce postoperative stiffness after arthroscopic rotator cuff repair?: a prospective randomized clinical trial

BACKGROUND

To investigate whether preemptive extensive rotator interval (RI) release during arthroscopic rotator cuff repair (ARCR) would reduce postoperative stiffness.

METHODS

From July 2015 to September 2016, a total of 80 patients who were scheduled for ARCR were enrolled and randomly allocated into 2 groups: the preemptive extensive RI release group (group 1, n=40) and the RI nonrelease group (group 2, n=40). The American Shoulder and Elbow Surgeons scale, Constant score, Korean Shoulder Scale (KSS), visual analog scale (VAS) pain score, and range of motion (ROM) were evaluated before surgery; 3, 6, and 12 months after surgery; and at last follow-up. Magnetic resonance imaging was performed at postoperative 12 months.

RESULTS

The mean follow-up period was 26.5 months. The functional and pain scores in both groups were significantly improved at the last follow-up (P < .05). Group 1 showed a significantly higher sum of ROM with a difference of 27° and 1.6 vertebral level of internal rotation compared to group 2 at postoperative 3 months (P < .05). Constant score and KSS were significantly higher in group 1 than in group 2 at this time point (P < .05). Functional scores and ROM were not significantly different between 2 groups at postoperative 6 or 12 months or at the last follow-up (P > .05). The retear rate and pathologic change of the long head of the biceps tendon during follow-up were not significantly different between the 2 groups (P > .05).

CONCLUSION

Arthroscopic preemptive extensive RI release can reduce early postoperative shoulder stiffness after ARCR but does not significantly change the overall clinical outcome after surgery.

Shoulder manipulation under targeted ultrasound-guided rotator interval block for adhesive capsulitis

OBJECTIVE

To describe and evaluate the outcome following shoulder manipulation under rotator interval block for the treatment of adhesive capsulitis.

MATERIALS AND METHODS

Patients with adhesive capsulitis referred by our local orthopaedic shoulder surgeons consented to targeted ultrasound-guided injection of the glenohumeral joint via the rotator interval. Inclusion criteria included a failure to respond to conservative treatment and the absence of a full-thickness rotator cuff tear. Twelve millilitres of a mixture of local anaesthetic and steroid was injected into the rotator interval using a 21-gauge needle, with a small volume of the same solution instilled into the subacromial bursa. Following injection, under local anaesthetic block, patients were gently manipulated into abduction, external rotation and internal rotation as far as they could comfortably tolerate. Patients were assessed pre-injection with documented pain scores from 0 to 10 on a visual analogue scale (VAS) and the Oxford Shoulder Score (OSS) questionnaire. Initial follow-up comprised a VAS pain score at 1 h, 24 h and 2 weeks. Clinical review by the referring orthopaedic surgeon was performed at 2 months post-injection. Long-term follow-up involved a VAS pain score and the OSS questionnaire at 5 months.

RESULTS

Forty patients were suitable for inclusion in the study. Twenty-three were female (57.5%) and 17 were male. The mean age was 52 years (range, 31-73 years). Twelve patients were post-operative. The duration of symptoms ranged from 3 months to 18 months. Mean pre-procedure OSS was recorded as 23.3 (range, 4-36). The mean VAS pain score was 7.7 before the procedure (range, 4 - 10), 3.4 at 1 h (range, 0-8), 2.9 at 24 h (range, 0-8), and 1.8 at 2 weeks (range 1-4). Orthopaedic follow-up at an average of 66 days post-injection was recorded in 18 patients. All patients reported initial improvement of their shoulder pain and return to near full range of movement; however, recurrence of adhesive capsulitis symptoms was recorded in 5 patients. One case of rupture of the long head of the biceps tendon was reported, but the patient remained asymptomatic. Long-term follow-up at 5 months was obtained in 31 patients, with a mean OSS of 42 (range, 21-60) and VAS of 2.3 (range, 0-7).

CONCLUSION

Manipulation under general anaesthesia is a well-recognised treatment for adhesive capsulitis. We report that targeted ultrasound-guided injection of the rotator interval and manipulation of the shoulder under local anaesthetic blockade result in good outcomes in reducing shoulder pain and symptoms of adhesive capsulitis with low recurrence and complication rates.

Adhesive capsulitis: review of imaging findings, pathophysiology, clinical presentation, and treatment options

Adhesive capsulitis, commonly referred to as "frozen shoulder," is a debilitating condition characterized by progressive pain and limited range of motion about the glenohumeral joint. It is a condition that typically affects middle-aged women, with some evidence for an association with endocrinological, rheumatological, and autoimmune disease states. Management tends to be conservative, as most cases resolve spontaneously, although a subset of patients progress to permanent disability. Conventional arthrographic findings include decreased capsular distension and volume of the axillary recess when compared with the normal glenohumeral joint, in spite of the fact that fluoroscopic visualization alone is rarely carried out today in favor of magnetic resonance imaging (MRI). MRI and MR arthrography (MRA) have, in recent years, allowed for the visualization of several characteristic signs seen with this condition, including thickening of the coracohumeral ligament, axillary pouch and rotator interval joint capsule, in addition to the obliteration of the subcoracoid fat triangle. Additional findings include T2 signal hyperintensity and post-contrast enhancement of the joint capsule. Similar changes are observable on ultrasound. However, the use of ultrasound is most clearly established for image-guided injection therapy. More aggressive therapies, including arthroscopic release and open capsulotomy, may be indicated for refractory disease, with arthroscopic procedures favored because of their less invasive nature and relatively high success rate.

ACR Appropriateness Criteria® Shoulder Pain-Atraumatic

Shoulder pain is one of the most common reasons for musculoskeletal-related physician visits. Imaging plays an important role in identifying the specific cause of atraumatic shoulder pain. This review is divided into two parts. The first part provides a general discussion of various imaging modalities (radiographs, arthrography, nuclear medicine, ultrasound, CT, and MRI) and their usefulness in evaluating atraumatic shoulder pain. The second part focuses on the most appropriate imaging algorithms for specific shoulder conditions including: rotator cuff disorders, labral tear/instability, bursitis, adhesive capsulitis, biceps tendon abnormalities, postoperative rotator cuff tears, and neurogenic pain. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Anterior capsular abnormality: another important MRI finding for the diagnosis of adhesive capsulitis of the shoulder

OBJECTIVE

To evaluate the usefulness of anterior capsular abnormality, thickening, and abnormal signal intensity on MRI for the diagnosis of adhesive capsulitis of the shoulder.

MATERIALS AND METHODS

This retrospective study included 29 patients with adhesive capsulitis and 20 controls. Clinical criteria with significant restricted passive motion was used for the diagnosis of adhesive capsulitis. The anterior capsular thickness and signal intensity were evaluated on the thickest portion of anterior glenohumeral joint capsule, located deep to the subscapularis muscle. In addition, the previously known MR findings of adhesive capsulitis, such as humeral and glenoid capsular thickness in axillary recess, maximal axillary capsular thickness, and coracohumeral ligament thickness, were measured. The presence of humeral and glenoid capsular abnormal hyperintensity in axillary recess, abnormal hyperintensity, and obliteration of the subcoracoid fat triangle were also evaluated.

RESULTS

All MRI findings significantly differed between adhesive capsulitis and controls. Among MR findings, multivariable analysis showed that anterior capsular thickness, maximal axillary capsular thickness, and anterior capsular abnormal hyperintensity were variables that could differentiate adhesive capsulitis from the control group, with odds ratios of 7.97, 17.75, and 12.41, respectively (p < 0.05). In ROC analysis, the anterior capsular thickness showed high diagnostic performances with an AUC of 0.897. The cut-off value of anterior capsular thickness at 3.5 mm showed excellent diagnostic accuracy, with sensitivity of 68.97% and specificity of 100%.

CONCLUSIONS

Anterior capsular abnormality, thickening, and abnormal hyperintensity can be used for the diagnosis of adhesive capsulitis of shoulder, in addition to previously known abnormal MRI findings.

Computed Tomography Arthrography Findings of Idiopathic Adhesive Capsulitis of the Hip: An Analog of Adhesive Capsulitis of the Shoulder

Objective

To identify useful imaging findings for the diagnosis of idiopathic adhesive capsulitis of the hip (ACH) on computed tomography arthrography (CTA).

Materials and Methods

Twenty-eight consecutive patients (29 hips; 7 males; mean age, 45.7 years; age range, 17–67 years) with ACH from October 2009 to March 2017 and 29 age- and sex-matched control patients from 2014 to 2016 were enrolled. All CTA images were evaluated by 2 radiologists independently for joint distensibility (anterior-posterior [AP] and superior-inferior [SI] joint cavity filling ratios), the presence of contrast filling around the ligamentum teres, and extracapsular contrast leakage. Fisher's exact test, Mann-Whitney U test, analysis of variance, and receiver operating characteristic curves were used for statistical analysis. P value less than 0.05 was considered to indicate statistical significance.

Results

The anterior joint cavity was significantly more obliterated in the ACH group (mean size, 3.7–4.0 mm) than in the control group (mean size, 4.8–5.0 mm; p < 0.05). The AP filling ratio was also significantly lower in the ACH group (0.6 vs. 1.1; p < 0.05) and decreased more as the ACH stage increased (mean anterior joint cavity size: 1.15 mm in stage 3 vs. 4.68 mm in stage 1; p < 0.05). Extracapsular contrast leakage was more common in the ACH group (27–28 vs. 20–21; p = 0.041 and 0.025, respectively).

Conclusion

On CTA, the anterior joint cavity may have earlier and more marked obliteration than joint cavities on other sides, and may be accompanied by extracapsular contrast leakage in ACH. These CTA findings may be helpful in the diagnosis of ACH.

Imaging of Usual and Unusual Complication of Rotator Cuff Repair

Several complications may be encountered after rotator cuff (RC) repair. A thorough knowledge of surgical interventions, normal postoperative findings, and postoperative complications is crucial to provide a timely diagnosis, improving the clinical outcome of patients. Postoperative complications may involve RC, implanted device, osteochondral tissue, surgical-site infection, peripheral nerves, soft tissues, and vascular structures. In this review, we discuss the usual and unusual complications detectable after RC repair.

Accuracy of Two Ultrasound-Guided Coracohumeral Ligament Injection Approaches: A Cadaveric Study

BACKGROUND

Glenohumeral idiopathic adhesive capsulitis is a common shoulder condition that hinders functionality. Addressing the pathology has been extensively researched. Ultrasound (US)-guided injections have shown their efficacy. However, no study has been conducted to compare anatomical accuracy between different approaches in targeting the coracohumeral ligament (CHL).

OBJECTIVE

To investigate whether US-guided injection of the CHL can be performed accurately using either the rotator interval (RI) or the coracoidal (CO) approach.

METHODS

An experimental cadaveric case series.

SETTING

Anatomy laboratory.

SPECIMENS

Both shoulders of 13 Thiel-embalmed cadavers.

INTERVENTIONS

Three physiatrists each injected a 0.1 mL bolus of colored dye in both shoulders of each cadaver using either the RI or the CO approach under US guidance. Each cadaver received a total of six injections (three injections per shoulder). The accuracy of the injection was determined following shoulder dissection by an anatomist.

MAIN OUTCOME MEASURE

The accuracy of the US-guided injection of the CHL.

RESULTS

The RI approach yielded 36 accurate injections, giving it an accuracy of 100%. With the CO approach two injections were deemed inaccurate yielding an accuracy of 94%. There was no significant difference in accuracy between all operators.

CONCLUSIONS

US-guided injection of the CHL can be performed accurately with both the RI and CO approaches. The RI approach was likely to be more accurate.

Determination of magnetic resonance imaging criteria for diagnosis of adhesive capsulitis

The objective of this study was to identify optimal magnetic resonance imaging (MRI) parameters and their cutoff values for diagnosing adhesive capsulitis (AC). One hundred shoulder MRI images with stage 2 AC (AC group) and 100 MRI images without AC (control group) were randomly reviewed by two experienced shoulder specialists. They were asked whether MRI findings were compatible with AC and measurement of MRI parameters. Sensitivity, specificity, and accuracy were calculated. Correlation between MRI parameters and the range of motions was also analyzed. The mean capsular thickness in the axillary recess (AR) (5.9 mm in the AC group vs. 3.6 mm in the control group) on coronal oblique T2-weighted images and the rotator interval (RI) (7.2 mm vs. 4.8 mm, respectively) on oblique sagittal proton-density images were significantly greater in the AC group than in the control group, whereas the width of RI showed no significant difference between two groups. The highest diagnostic cutoff values were 4.5 mm for the AR and 6 mm for the RI, with sensitivity (91% and 88%, respectively), specificity (90% and 90%), and accuracy (90% and 89%). Capsular thickness in the AR and RI was significantly correlated with external rotation (P = 0.047) and internal rotation (P = 0.023). On conventional MRI, capsular thickness greater than 4.5 mm in the AR or 6 mm in the RI can be an optimal criterion for diagnosing AC. Capsular thickness in the AR and RI was correlated with the range of rotational motion.

Correlations between Capsular Changes and ROM Restriction in Frozen Shoulder Evaluated by Plain MRI and MR Arthrography

Background:

Evaluation of the Range Of Motion (ROM) is one of the important procedures for shoulder disorders. The purpose of this study was to investigate correlations between capsular changes and ROM restrictions evaluated by both plain magnetic resonance imaging (MRI) and Magnetic Resonance Arthrography (MRA) in the same patients with frozen shoulder.

Methods:

Between March 2015 and June 2016, 24 patients with frozen shoulders (13 male and 11 female patients, mean age 60.5) with severe ROM restriction who underwent both MRI and MRA on the same affected side were evaluated. We evaluated 1) ROM, 2) the coracohumeral ligament (CHL) thickness, 3) the joint capsule thickness in the axillary recess (humeral and glenoid sides), 4) the area of the axillary recess, and 5) the capsular area of the axillary recess.

Results:

Positive correlations were found between the axillary area and forward flexion (FF) (R = 0.43, P = 0.035), lateral elevation (LE) (R = 0.66, P<0.001), external rotation (ER)(R = 0.43, P = 0.035), 90° abduction with external rotation (AER)(R = 0.56, P = 0.004), and hand behind the back (HBB)(R = 0.6, P = 0.002) on MRA. Negative correlations were found between the joint capsule at the glenoid side and ER and HBB in both MRI and MRA.

Conclusion:

The axillary area was significantly correlated with ROM restriction in FF, LE, ER, AER, and HBB on MRA. Thickness of the joint capsule at the glenoid side is an important factor for ROM restriction in frozen shoulder.

Level of Evidence:

Level 3, Study of Diagnostic Test.

3D volumetric MR arthrographic assessment of shoulder joint capacity in patients with primary adhesive capsulitis

OBJECTIVE

To evaluate the three-dimensional (3D) volumetric MR arthrographic findings of shoulder joint capacity in patients with primary adhesive capsulitis.

METHODS

Thin-section 3D volumetric MR arthrography sequences of the shoulder joint were obtained in 28 patients with clinically and radiologically proven primary adhesive capsulitis and in 25 controls. Volumetric measurements of the total glenohumeral joint capacity, extra-articular contrast material leakage, and the rotator interval, axillary recess, and biceps tendon sheath capacities were performed for the study and control groups.

RESULTS

Mean volume of the rotator interval was 7.67 ± 2.6 cm³ in the study group, which was significantly lower than in the control group (12.31 ± 2.5 cm³) (p < 0.0001). Mean volume of the bicipital groove was significantly decreased in the patient group compared to the control group (1.67 ± 0.9 cm³ vs 2.88 ± 0.9 cm³) (p ≤ 0.0001). Mean volume of extra articular contrast material extravasation was 9.93 ± 1.7 cm³ in the patient group, which was significantly higher than in the control group (5.1 ± 1.4 cm³) (p = 0.002). Mean total glenohumeral joint volume was 22.52 ± 1.1 cm³ in the patient group and 26.01 ± 1.2 cm³ in the control group (p = 0.003).

CONCLUSION

On 3D volumetric MR arthrographic examination, obliterations in the biceps tendon sheath and rotator interval as well as decreased joint capacity may be useful imaging criteria for diagnosing primary adhesive capsulitis.

ADVANCES IN KNOWLEDGE

In the present study, MR arthrography showed contrast material extravasation in 71% of the patients and showed extra articular contrast material extravasation in 48% of the control subjects. On 3D volumetric MR arthrographic examination, obliterations in the biceps tendon sheath and rotator interval as well as decreased joint capacity may be useful imaging criteria for diagnosing primary adhesive capsulitis.In patients with primary adhesive capsulitis, thin-section 3D volumetric MR arthrography is a useful imaging modality to evaluate both joint capacity and capsular structure.

Ultrasound measurements of axillary recess capsule thickness in unilateral frozen shoulder: study of correlation with MRI measurements

OBJECTIVE

The aims of this study were to compare the ultrasound thickness of the affected axillary recess capsule (ARC) with that of the unaffected ARC in patients with frozen shoulder (FS), to analyze whether the ultrasound measurements of the ARC thickness correlate with those obtained using MRI, and to assess whether the ultrasound thickness of the ARC correlates with the patterns of range of motion limitation.

MATERIALS AND METHODS

Forty-four patients with clinically diagnosed unilateral FS and MRI evaluation performed ultrasound measurement of ARC. The ultrasound measurement of the ARC thickness was performed with the patients in a supine position with their shoulder abducted by 40°. The ARC thickness was also measured by MRI on oblique coronal images by another physician blinded to the ultrasound measurements. With both ultrasound and MRI, ARC thickness was determined at the widest portion of the capsule.

RESULTS

The ultrasound thickness of ARC was significantly higher in the affected shoulder (4.4 ± 1.1 mm) than in the unaffected one (2.2 ± 0.5 mm) (p < 0.001). The ultrasound thickness of the ARC in the affected shoulder correlated with that measured by MRI (8.9 ± 1.9 mm) (p < 0.001, r = 0.83). The ARC thickness, whether measured by ultrasound or MRI, was not significantly related to the limitation of movement in specific directions.

CONCLUSION

Ultrasound can demonstrate the difference in ARC thickness between affected and unaffected shoulders in patients with unilateral FS. The ARC thickness measured by ultrasound correlates with that measured by MRI.

Ultrasound-guided coracohumeral ligament release

Long-term follow-up of patients with adhesive capsulitis (AC) reveals that approximately half of them suffer from a limited range of shoulder motion, particularly external and/or internal rotation. We report the surgical technique and short-term clinical outcomes of ultrasound-guided release of the thickened coracohumeral (CH) ligament in 8 patients (9 shoulders) with AC. Passive external rotation with the arm by the side significantly increased from an average of 18° preoperatively to 47° immediately after CH ligament release. VAS and ASES scores were improved at 3months follow-up in all 9 shoulders, and maintained at 6months follow-up in 6 shoulders. No procedure-related adverse events developed over the 6-month follow-up period. Ultrasound-guided release for thickened CH ligament is a reliable and effective minimally invasive surgery for persistent limited external rotation due to AC of the shoulder.

Is the Frozen Shoulder Classification a Reliable Assessment?

Background

Although a common shoulder disease, there are no accepted classification criteria for frozen shoulder (FS). This study therefore aimed to evaluate the accuracy of the conventionally used FS classification system.

Methods

Primary FS patients (n=168) who visited our clinic from January 2010 to July 2015 were included in the study. After confirming restrictions of the glenohumeral joint motion and absence of history of systemic disease, trauma, shoulder surgery, shoulder muscle weakness, or specific x-ray abnormalities, the Zuckerman and Rokito’s classification was employed for diagnosing primary FS. Following clinical diagnosis, each patient underwent a shoulder magnetic resonance imaging (MRI) and blood tests (lipid profile, glucose, hemoglobin A1c, and thyroid function). Based on the results of the blood tests and MRIs, the patients were reclassified, using the criteria proposed by Zuckerman and Rokito.

Results

New diagnoses were ascertained including blood test results (16 patients with diabetes, 43 with thyroid abnormalities, and 149 with dyslipidemia), and MRI revealed intra-articular lesions in 81 patients (48.2%). After re-categorization based on the above findings, only 5 patients (3.0%) were classified having primary FS. The remaining 163 patients (97.0%) had either undiagnosed systemic or intrinsic abnormalities (89 patients), whereas 74 patients had both.

Conclusions

These findings demonstrate that most patients clinically diagnosed with primary FS had undiagnosed systemic abnormalities and/or intra-articular pathologies. Therefore, a modification of the Zuckerman and Rokito’s classification system for FS may be required to include the frequent combinations, rather than having a separate representation of systemic abnormalities and intrinsic causes.

Clinical outcome of arthroscopic capsular release for frozen shoulder: essential technical points in 255 patients

Background

The purpose of this study was to investigate the long-term clinical outcome and its related factors regarding the severity of adhesion of CH ligament over long head of biceps (LHB) after shoulder arthroscopic capsular release for frozen shoulder with technical points in 255 patients.

Methods

We performed arthroscopic capsular release for frozen shoulder in 267 shoulders of 255 patients, 112 males and 143 females, with mean age of 56.39 years, mean disease duration periods of 0.934 years for conservative treatment, and mean follow-up periods of 5.6 years. The frozen shoulders were divided based on the severity of adhesion between CH ligament over LHB: those with slight degree of synovitis, no adhesion by obtuse rod, and slight thickness of the released capsule (type A), those with moderate degree of synovitis, moderate adhesion of the LHB by obtuse rod, and moderate thickness of the released capsule (type B), and those with severe degree of synovitis, severe adhesion of the LHB by obtuse rod, and severe thickness of the released capsule adhesion and a flatly shaped LHB (type C). We assessed the clinical factors related to the scoring of the shoulders by the criteria of the American Shoulder and Elbow Surgeons (ASES) and the relationship with severity of LHB adhesion.

Results

The ASES scores improved at 5 years postoperatively in all three groups significantly. The range of motion also significantly improved in all three groups significantly. The severity of the LHB adhesion over the CH ligament was confirmed to influence the ASES scores before and after the arthroscopic capsular release. There was a significant difference between type A and type B (p < 0.0001) or type C (p < 0.0001) before and after surgery. Logistic regression analysis showed disease duration, diabetes mellitus (DM), and ASES score were significantly associated to the severity type of LHB, especially DM has high odds ratio and was a risk factor for LHB adhesion. There is no adverse event including dislocation or axillary nerve injury and recurrence after arthroscopic capsular release at 5 years after surgery.

Conclusions

The long-term results of arthroscopic capsular release in frozen shoulder were confirmed in 255 patients. The severity of LHB adhesion over the CH ligament, a pathological condition related to DM as a risk factor, seems to play an important role in the functional outcome. Therefore, the sufficient release of LHB was essential technical point for arthroscopic capsular release in frozen shoulder.

Restriction of Passive Glenohumeral Abduction Combined With Normal Passive External Rotation Is a Diagnostic Feature of Calcific Tendinitis

Background:

Passive glenohumeral range of motion may be characteristically limited to specific shoulder pathologies. While pain associated with loss of range of passive external glenohumeral rotation is recognized as a salient feature in adhesive capsulitis, restriction of glenohumeral range of motion in calcific tendinitis of the supraspinatus tendon has never been studied.

Hypothesis:

On the basis of clinical observation, we hypothesized that calcific tendinitis of the supraspinatus tendon is associated with loss of passive glenohumeral abduction without loss of external rotation.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Ranges of passive glenohumeral rotation and abduction, which are measured with a standardized protocol in our institution, were retrospectively reviewed and compared for patients diagnosed with either adhesive capsulitis or calcific tendinitis of the supraspinatus tendon. A total of 57 patients met the inclusion criteria for the calcific tendinitis, and 77 met the inclusion criteria for the adhesive capsulitis group.

Results:

When compared with the contralateral, unaffected shoulder, glenohumeral abduction in the calcific tendinitis group was restricted by a median of 10° (interquartile range [IQR], –20° to –5°) as opposed to glenohumeral external rotation, which was not restricted at all (median, 0°; IQR, 0° to 0°). The adhesive capsulitis group showed a median restriction of glenohumeral abduction of 40° (IQR, –50° to –30°) and a median restriction of passive glenohumeral external rotation of 40° (IQR, –60° to –30°).

Conclusion:

Calcific tendinitis of the supraspinatus does not typically cause loss of external rotation but is frequently associated with mild isolated restriction of abduction. This finding can be used to clinically differentiate adhesive capsulitis from calcific tendinitis.

The Association between the Magnetic Resonance Imaging Findings of Adhesive Capsulitis and Shoulder Muscle Fat Quantification Using a Multi-Echo Dixon Method

Objective

To investigate the association between the magnetic resonance imaging (MRI) findings of adhesive capsulitis and shoulder muscle fat percentages using a multi-echo Dixon method.

Materials and Methods

Twenty-four patients with clinical diagnoses of adhesive capsulitis and either intact rotator cuffs or Ellman grade 1 partial tears as indicated by MRI scans were included. Two radiologists independently evaluated MRI scans of adhesive capsulitis as follows: presence or absence of axillary recess capsular and extracapsular hyperintensities; thickness of the coracohumeral ligament; thickness of abnormal rotator interval soft tissue; and thickness of glenoidal/humeral axillary recess capsules. Fat quantifications of the supraspinatus, infraspinatus, teres minor, subscapularis, teres major and posterior deltoid muscles were performed using multi-echo Dixon imaging at three locations. Inter-rater agreement was assessed. Differences in fat percentages were assessed and correlations between fat percentages and quantitative measurements were evaluated.

Results

The fat percentage of the supraspinatus was significantly higher in patients with extracapsular hyperintensity (present, 3.00 ± 1.74%; absent, 1.81 ± 0.80%; p = 0.022). There were positive correlations between the fat percentage of the teres minor and the thicknesses of the abnormal rotator interval soft tissue (r = 0.494, p = 0.014) and the glenoidal axillary recess capsule (r = 0.475, p = 0.019). After controlling for the effects of age, sex and clinical stage, the relationship between the teres minor fat percentage and the thickness of the abnormal rotator interval soft tissue was statistically significant (r = 0.384, p = 0.048). Inter-rater agreement was almost perfect for fat quantification (intraclass correlation coefficients [ICC] > 0.9) and qualitative analyses (k = 0.824), but were variable for quantitative measurements (ICC, 0.170-0.606).

Conclusion

Several MRI findings of adhesive capsulitis were significantly related to higher fat percentages of shoulder muscles.

Correlations of magnetic resonance imaging findings with clinical symptom severity and prognosis of frozen shoulder

PURPOSE

To evaluate the correlation between indirect magnetic resonance (MR) arthrographic imaging findings and the clinical symptoms and prognosis of patients with frozen shoulder.

METHODS

Indirect MR arthrography was performed for 52 patients with primary frozen shoulder (mean age 55.1 ± 9.0 years) and 52 individuals without frozen shoulder (mean age 53.1 ± 10.7 years); capsular thickening and enhancement of the axillary recess as well as soft tissue thickening of the rotator interval were evaluated. Clinical symptom severity was assessed using the Visual Analogue Scale for Pain (VAS Pain), simple shoulder test (SST), Constant score, American Shoulder and Elbow Surgeons (ASES) score, and range of motion (ROM). At 6-month follow-up, we evaluated whether MR arthrography findings correlated with the clinical symptoms and prognosis.

RESULTS

Capsular thickening and enhancement of the axillary recess as well as soft tissue thickening of the rotator interval were significantly greater in the patient group than in the controls (p < 0.001). Capsular thickening of the axillary recess did not correlate with clinical symptoms or ROM (n.s.); however, capsular enhancement correlated with clinical symptom severity according to VAS Pain (p = 0.005), SST (p = 0.046), and ASES scores (p = 0.009). Soft tissue thickening of the rotator interval did not correlate with clinical symptom severity, but was associated with external rotation limitation (p = 0.002). However, none of the parameters correlated with clinical symptoms at 6-month follow-up.

CONCLUSIONS

Indirect MR arthrography provided ancillary findings, especially with capsular enhancement, for evaluating clinical symptom severity of frozen shoulder, but did not reflect the prognosis. MR findings in frozen shoulder should not replace clinical judgments regarding further prognosis and treatment decisions.

LEVEL OF EVIDENCE

IV.

Postoperative Shoulder Imaging: Rotator Cuff, Labrum, and Biceps Tendon

Imaging interpretation of the postoperative shoulder is a challenging and difficult task for both the radiologist and the orthopedic surgeon. The increasing number of shoulder rotator cuff, labrum, and biceps tendon repairs performed in the United States also makes this task a frequent occurrence. Whether treatment is surgical or conservative, imaging plays a crucial role in patient care. Many imaging findings can be used to predict prognosis and functional outcomes, ultimately affecting treatment. In addition, evolving surgical techniques alter the normal anatomy and imaging appearance of the shoulder such that accepted findings proved to be pathologic in the preoperative setting cannot be as readily described as pathologic after surgery. An understanding of common surgical procedures of the shoulder can aid in recognizing normal expected postoperative findings and discerning common complications. Although magnetic resonance (MR) imaging and MR arthrography are widely used, implementing a multimodality imaging approach for evaluation of the postoperative shoulder can provide additional imaging information that may be decisive and vital to diagnosis. The high spatial resolution of both computed tomography with arthrography and ultrasonography makes them additional modalities to consider, especially when dealing with metal artifact. To provide an accurate radiologic interpretation of high clinical value, radiologists should approach the postoperative shoulder comprehensively with knowledge of the anatomy, surgical techniques and complications, clinical outcomes, and imaging pitfalls. ^©RSNA, 2016.

Imaging of the coracoglenoid ligament: a third ligament in the rotator interval of the shoulder

OBJECTIVE

The coracoglenoid ligament (CGL) forms part of the anterosuperior capsuloligamentous complex of the shoulder. Although it has received attention in the anatomical literature, it has not been investigated on imaging. The purpose of this study is to determine the percentage value and the interobserver agreement of identification and classification of the CGL on MR and MR arthrography (MRA) imaging.

MATERIALS AND METHODS

Retrospectively, 280 MR and 150 MRA examinations were evaluated for detection of the CGL by two musculoskeletal radiologists. On the MRA examinations the CGL configuration in relation to the superior glenohumeral (SGHL) and coracohumeral ligament (CHL) was classified into five types. Additionally, the percentage of intra-articular appearance of the CGL and its mean thickness value were calculated. Finally, a possible correlation between pathological condition and anatomical type was evaluated on MRA.

RESULTS

The CGL could be identified in 56%/54% of MRI and in 76%/77% of MRA examinations. On MRA, the CGL was detected as distinct structures in 37%/35% of cases and it appeared fused (partially or totally) with the SGHL and/or CHL in 39%/42%; it was absent in 12%/12% and it appears undistinguishable in the remaining cases. The interobserver agreement was excellent (κ = 0.98 for detection on MRI; p = 0.927 for classification of anterosuperior anatomy on MRA; κ = 0.873 and 0.978 for identification on sagittal and axial external rotation MRA respectively; κ = 0.943 for classification as intra- or extra-articular on MRA).

CONCLUSIONS

The CGL can be reliably identified on MRI and MRA.

Adhesive capsulitis of the shoulder: pain intensity and distribution

PURPOSE

Papers regarding adhesive capsulitis (AC) of the shoulder focused on etiology, epidemiology, diagnosis, and treatment; until now, information on shoulder pain characteristics is still scarce. Our aim was to analyze pain intensity and distribution in patients with AC.

METHODS

The study group was composed of 278 (133M-145F) consecutive patients with AC. After diagnosis, shoulder pain distribution was assessed through an upper limb pain map and pain intensity through a visual analog scale. Patients were distinguished on the basis of gender, age, time elapsed from onset of symptoms, and severity of functional limitation. Data were submitted to statistical analysis.

RESULTS

Intensity of shoulder pain caused by AC was higher in females (p < 0.05); it did not vary with the side and between patient younger and older than 55 years. Patients whose pain arose from more than 3 months suffered a lower intensity of shoulder pain. Furthermore, pain intensity was higher in the most severe form of AC (active forward flexion < 60°) (p < 0.05). Pain was localized predominantly on the anterior aspect of the shoulder (dermatomes C5-C6) and rarely extended beyond the distal third of the arm. No differences were found in pain distribution between male and female, between patients with pain from less or more than 3 months and between different levels of AC severity (p > 0.05).

CONCLUSION

Shoulder pain due to AC may be influenced by gender and severity of functional limitation. AC pain distribution principally involves anterior aspect of the shoulder with downward extension of the arm until its distal third.

LEVELS OF EVIDENCE

Level IV.

Correlation of Joint Volume and Passive Range of Motion With Capsulo-Synovial Thickness Measured by Contrast-Enhanced Magnetic Resonance Imaging in Adhesive Capsulitis

BACKGROUND

No study has investigated the relationship between the findings of contrast-enhanced magnetic resonance imaging (CE-MRI) and the joint volume of the shoulder, which has been considered the standard reference for diagnosis of adhesive capsulitis (AC).

OBJECTIVE

To investigate the relationships among the capsulo-synovial thickness measured by CE-MRI, joint volume, and passive range of motion (ROM) in patients with AC.

DESIGN

This was a retrospective study.

SETTING

The study took place at an institutional practice.

PATIENTS

Medical record of 103 patients (46 male and 57 female), who were treated with sonographically guided intra-articular injection with diagnosis of AC and underwent CE-MRI to rule out other concomitant shoulder disease, were retrospectively reviewed.

METHODS

Passive ROM and glenohumeral joint (GHJ) volume were measured before and during sonographically guided injection. The thickness of the enhancing portion of the capsulo-synovium was measured at the axillary recess and rotator interval on CE-MRI.

MAIN OUTCOME MEASUREMENTS

The relationship among the thickness of the enhancing portion on CE-MRI, GHJ volume, and passive ROM was analyzed using the Pearson correlation coefficient.

RESULTS

Capsulo-synovial thickness measured by CE-MRI at the enhancing portion of the axillary recess inversely correlated with GHJ volume (ρ = -0.444, P < .001), whereas at the rotator interval, this finding was not observed. At the axillary recess, the capsulo-synovial thickness inversely correlated with abduction (ρ = -0.400, P < .001), forward elevation (ρ = -0.378, P < .001), and external rotation (ρ = -0.297, P < .01), but at the rotator interval, such statistically significant correlations were not shown.

CONCLUSION

The capsulo-synovial thickness measured by CE-MRI at the enhancing portion of the axillary recess could represent obliterated joint capacity and clinical impairment (restricted passive ROM), which could help in diagnosing AC and in differentiating other shoulder diseases that may mimic this condition.

LEVEL OF EVIDENCE

III.

Adhesive Capsulitis of the Shoulder: Evaluation With US-Arthrography Using a Sonographic Contrast Agent

Adhesive capsulitis (AC) is a painful and disabling disorder, which caused restricted motion and chronic pain of shoulder. Intracavitary contrast-enhanced ultrasound has been recently applied to assess obstructive bile duct diseases, tubal patency, vesicoureteric reflux and so on. The aim of this study was to detect the value of US-arthrography by injecting the contrast agent SonoVue into glenohumeral joint compared with US in diagnosing AC. Utrasound (US) and US-arthrography images of 45 patients with AC were compared with that of 45 control subjects without AC with MRI as a gold standard. Patients with AC had a significantly thickened coracohumeral ligment (CHL, 3.1 mm) and inferior capsule (3.5 mm) on US, and a decreased volume of axillary recess (1.14 ml) on US-arthrography compared with the control subjects (1.59 ml). Filling defect (91.1%) and synovitis-like abnormality (75.6%) in the joint on US-arthrography were more sensitive than that of rotator interval abnormality (71.1%), thickened CHL more than 3 mm (64.4%), thickened inferior capsule more than 3.5 mm (66.7%) on US respectively for diagnosis of AC. Consequently, US-arthrography was more effective method than US for assessment of AC. Filling defects of joint cavity and synovitis-like abnormality in the joint are characteristic US-arthrography findings for diagnosing AC.

CT arthrography of adhesive capsulitis of the shoulder: Are MR signs applicable?

OBJECTIVE

To determine if diagnostic signs of adhesive capsulitis (AC) of the shoulder at Magnetic Resonance Imaging (MRI) and arthrography (MRA) are applicable to CT arthrography (CTA).

METHODS

22 shoulder CTAs with AC were retrospectively reviewed for features described in MR literature. The control group was composed of 83 shoulder CTA divided into four subgroups 1) normal (N = 20), 2) omarthrosis (N = 19), 3) labral injury (N = 23), and 4) rotator cuff tear (N = 21). Two musculoskeletal radiologists assessed the rotator interval (RI) for obliteration, increased width and thickening of coracohumeral ligament (CHL). The width and capsule thickness of the axillary recess were measured.

RESULTS

The width of the axillary recess was significantly decreased in the AC group (4.6 ± 2.6 mm versus 9.9 ± 4.6 mm, p ≤ 0.0001; sensitivity and specificity of 84% and 80%). Thickness of the medial and lateral walls of the axillary capsule was significantly increased in the AC group (5.9 ± 1.3 mm versus 3.7 ± 1.1 mm, p ≤ 0.0001 and 5.7 ± 1 mm versus 3.5 ± 1.3 mm, p ≤ 0.0001, respectively). CHL thickness was significantly increased in the AC group (4.1 ± 1 mm (p ≤ 0.001)) in comparison to others groups. Obliteration of the RI was statistically significantly more frequent in patients with AC (72.7% (16/22) vs. 12% (10/83), p < 0.0001). Width of the RI did not differ significantly between patients and controls (p ≥ 0.428).

CONCLUSION

Decreased axillary width, and thickened axillary capsule are MR signs of AC applicable to CTA. Evaluation of rotator interval seems useful and reproducible only for obliteration.

Adhesive capsulitis of the shoulder: review of pathophysiology and current clinical treatments

Adhesive shoulder capsulitis, or arthrofibrosis, describes a pathological process in which the body forms excessive scar tissue or adhesions across the glenohumeral joint, leading to pain, stiffness and dysfunction. It is a debilitating condition that can occur spontaneously (primary or idiopathic adhesive capsulitis) or following shoulder surgery or trauma (secondary adhesive capsulitis). Here, we review the pathophysiology of adhesive shoulder capsulitis, highlighting its clinical presentation, natural history, risk factors, pathoanatomy and pathogenesis. Both current non-operative and operative treatments for adhesive capsulitis are described, and evidence-based studies are presented in support for or against each corresponding treatment. Finally, the review also provides an update on the gene expression profile of adhesive capsulitis and how this new understanding can help facilitate development of novel pharmacological therapies.

Focal uptake at the rotator interval or inferior capsule of shoulder on 18F-FDG PET/CT is associated with adhesive capsulitis

OBJECTIVE

To determine if focal increased uptake at the rotator interval (RI) and/or inferior capsule (IC) on¹⁸F-FDG PET/CT ("positive PET") predicts the presence of adhesive capsulitis (AC).

MATERIALS AND METHODS

Three populations were retrospectively examined. Group 1 included 1,137 consecutive ¹⁸F-FDG PET/CT studies and was used to determine the prevalence of focal uptake at the RI or IC. Group 2 included 361 cases from a 10-year period with ¹⁸F-FDG PET/CT and MRI of shoulder performed within 45 days of each other and was used to enrich the study group. Group 3 included 109 randomly selected patients from the same time frame as groups 1 and 2 and was used to generate the control group. The study group consisted of 15 cases from the three groups, which had positive PET findings. PET/CT images were assessed in consensus by two musculoskeletal radiologists. The reference standard for a diagnosis of AC was clinical and was made by review of the medical record by a pain medicine physician.

RESULTS

The prevalence of focal activity at either the RI or IC ("positive PET") was 0.53%. Nine patients had a clinical diagnosis of AC and 15 patients had a positive PET. The sensitivity and specificity of PET for detection of AC was 56% and 87%, respectively. PET/CT had a positive likelihood ratio for AC of 6.3 (95% CI: 2.8-14.6).

CONCLUSIONS

Increased uptake at the RI or IC on PET/CT confers a moderate increase in the likelihood of AC.

Spectrum of Benign Articular and Periarticular Findings at FDG PET/CT

Whole-body fluorine 18 fluorodeoxyglucose (FDG) positron-emission tomography (PET)/computed tomography (CT) is performed primarily for oncologic indications; however, FDG uptake is not specific for malignancy. Herein we focus on causes of increased FDG uptake in and around joints, as lesions in these locations are commonly benign. A combination of primary intra-articular processes and osseous processes that may occur near the joint space will be discussed. Causes of intra-articular and periarticular increased FDG activity can be broadly divided into infectious, inflammatory, degenerative, and benign neoplastic categories. A familiarity with the full range of these processes is important to avoid misinterpretation, in turn decreasing unnecessary follow-up studies, procedures, and treatments. Differentiation from malignancy is often possible on the basis of a different level of FDG activity, divergent response to therapy, or differing changes over time, in comparison with a patient's known primary cancer. Recognizing an intra-articular lesion location can also be critical, as intra-articular metastases are rare. In some cases, benign FDG-avid articular and periarticular entities have a specific appearance at FDG PET/CT and a correct diagnosis may be made without any additional workup. In most other cases, comparison with prior studies and/or additional imaging can afford an accurate diagnosis. This review is meant to introduce the reader to a spectrum of benign FDG-avid articular and periarticular processes that may be encountered at oncologic FDG PET/CT to increase confidence and diagnostic accuracy. (©)RSNA, 2016.

Clinical correlation of metabolic parameters on 18F-FDG PET/CT in idiopathic frozen shoulder

Objective

Because positron emission tomography/computed tomography (PET/CT) using fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) can be used to visualize inflammation of the musculoskeletal system, it may help elucidate the pathophysiology of frozen shoulder (FS). The purpose of this study was to characterize the uptake pattern on ¹⁸F-FDG PET/CT in patients with idiopathic FS and to determine if there is a correlation between its metabolic parameters and clinical findings.

Methods

¹⁸F-FDG PET/CT was conducted to 35 patients with unilateral idiopathic FS. Clinical data including pain, functional scores, and passive range of motion (ROM) were collected. Maximum standardized uptake values (SUVmax) were measured at the four regions of interest (ROIs): rotator interval (RI), anterior joint capsule (AJC), axillary recess (AR), and posterior joint capsule (PJC) from the attenuation-corrected axial images.

Results

Mean SUVmax values for four ROIs of the affected shoulder were significantly higher than those of the unaffected shoulder. Mean SUVmax values of RI and AR were significantly higher than those of AJC and PJC and mean SUVmax of AJC was significantly higher than that of PJC in the affected side. Three recognizable patterns of increased uptake were noted: (1) AR dominant type (15 patients); (2) RI dominant type (9 patients); (3) both RI and AR dominant type (11 patients). The SUVmax of AR showed negative correlation with abduction and forward flexion. The SUVmax of RI showed negative correlation with external rotation and internal rotation. The SUVmax of AJC showed negative correlation with all ROMs. However, there was no significant correlation between the SUVmax of PJC and any ROM.

Conclusion

Our study demonstrates that the anterior–inferior capsular portion, including RI and AR, is the main pathologic site of idiopathic FS and reveals significant correlations between ROM and metabolic parameters on ¹⁸F-FDG PET/CT. These results imply that AR and RI lesions are related to elevational limitations and rotational limitations, respectively.

Sonography of the Coracoid Process Region

Sonography is widely known as an accurate imaging tool for assessment of the rotator cuff of the shoulder, the long head of the biceps tendon, and joint disorders, but it is rarely performed to evaluate the coracoid process and the adjacent soft tissues. Nevertheless, sonography can show anatomic details of this region and be used to assess several pathologic conditions. The aims of this pictorial essay are to briefly review the anatomy of the coracoid process region, describe examination technique and normal sonographic appearances, and present the sonographic findings of the main disorders affecting this region.

Characteristics of dynamic magnetic resonance imaging of idiopathic severe frozen shoulder

BACKGROUND

The purpose of this study was to evaluate the effectiveness of current techniques for dynamic 3-dimensional magnetic resonance imaging (MRI) in the diagnosis of idiopathic severe frozen shoulder (FS).

MATERIALS AND METHODS

Subjects consisted of 5 healthy volunteers and 16 patients with idiopathic severe FS. We defined severe idiopathic FS as follows: range of motion ≤100° in forward flexion, ≤10° in external rotation, and ≤L5 in internal rotation. All patients suffered from continued global range of motion loss for at least 6 months. We evaluated the diagnostic characteristics of 3-dimensional dynamic MRI in FS patients compared with those in healthy volunteers.

RESULTS

MRI of all FS patients displayed an abnormal intake of blood flow from the acromial arterial network and the branches of circumflex humeral arteries into the axillary pouch and the rotator interval. We named this finding "burning sign." The burning sign was present at all phases of the condition. In the FS group, the patients with enhanced deposition of contrast medium in the axillary pouch in the delayed phase (n = 11) had a statistically significant score for pain during exercise, higher than that of patients with reduced deposition of contrast medium at the same site (n = 5; P = .027).

CONCLUSION

Burning sign is an abnormal finding that appears in dynamic MRI of severe FS. Hence, the burning sign may be associated with pain and inflammation in idiopathic FS.

Correlations of coracohumeral ligament and range of motion restriction in patients with recurrent anterior glenohumeral instability evaluated by magnetic resonance arthrography

BACKGROUND

Evaluation of range of motion (ROM) restriction before treatment of shoulder disorders is important for predicting the final functional outcomes. The purpose of this study was to investigate correlations of thickness of the coracohumeral ligament (CHL) and ROM restriction in patients with recurrent anterior glenohumeral instability.

METHODS

Between January 2005 and March 2015, 181 shoulders (137 male and 44 female patients; mean age, 29.3 years) with recurrent anterior glenohumeral instability treated with an arthroscopic Bankart repair were enrolled in this study. We evaluated preoperative ROM, thickness of the CHL, and obliteration of the subcoracoid fat triangle on magnetic resonance arthrography. ROM measurements, including forward flexion (FF), external rotation with the arm at the side (ER), and hand behind the back (HBB), were made in a standing position.

RESULTS

There were significant negative correlations between FF and age (P < .001) and between HBB and age (P < .001) but not between ER and age (P = .11). The thickness of the CHL significantly increased with age (P < .001). FF, ER, and HBB were significantly restricted in patients with obliteration compared with those without obliteration (P < .001, P = .004, P < .001, respectively).

CONCLUSIONS

Obliteration of the subcoracoid fat triangle and the thickness of the CHL positively correlated with ROM restrictions, and these changes were greater with age in patients with recurrent anterior glenohumeral instability.

Adhesive Capsulitis of the Shoulder Joint: Value of Glenohumeral Distance on Magnetic Resonance Arthrography

OBJECTIVE

To evaluate the usefulness of glenohumeral distance (GHD) on axial images of magnetic resonance (MR) arthrography for diagnosis of adhesive capsulitis and to compare this finding with previously reported classic MR arthrographic findings of adhesive capsulitis.

MATERIALS AND METHODS

Our study was approved by the institutional ethical review board of our institute. We evaluated 41 patients (M-F, 35:6; mean age, 46 years; adhesive capsulitis, 21; no adhesive capsulitis, 20) who underwent MR arthrography. Two radiologists measured GHD, width of the axillary recess, and capsular thickness in consensus. The GHD was measured from the subchondral bone of the glenoid fossa to the subchondral bone of the humeral head at the level of the midline of the humeral head. Glenohumeral distance (anterior, middle, posterior, and mean), width of the axillary recess, and capsular thickness (anterior, posterior, and mean) were compared in the adhesive capsulitis and no adhesive capsulitis groups using the Mann-Whitney U test.

RESULTS

The mean GHD of the no adhesive capsulitis group was longer than that of the adhesive capsulitis group. The length differences were statistically significant (P < 0.05). The mean width of the axillary recess of the no adhesive capsulitis group was significantly wider than that of the adhesive capsulitis group (P < 0.001). The mean capsular thickness of the no adhesive capsulitis group was significantly thinner than that in the adhesive capsulitis group (P = 0.001).

CONCLUSIONS

A decreased GHD on MR arthrography can be another useful feature to diagnose adhesive capsulitis in addition to previously presented radiologic features such as capsular thickening and reduced axillary recess capacity.

High-Pressure Balloon-Assisted Stretching of the Coracohumeral Ligament to Determine the Optimal Stretching Positions: A Cadaveric Study

BACKGROUND

The coracohumeral ligament (CHL) is a thick capsular structure and markedly thickened when affected by adhesive capsulitis. Therapeutic stretching is the most commonly applied treatment for adhesive capsulitis, but optimal stretching postures for maximal therapeutic effects on the CHL have not been fully investigated.

OBJECTIVE

To investigate the most effective stretching direction for the CHL by measuring the stretching intensity in 5 different directions and to determine whether the stretching intervention resulted in loosening of the ligament by comparing the changes of CHL tightness before and after stretching.

DESIGN

Biomechanical cadaver study.

SETTING

Academic institution cadaver laboratory.

PARTICIPANTS

Nine fresh frozen cadaveric shoulders.

METHODS

A high-pressure balloon catheter inserted under the CHL and intraballoon pressure was measured, to evaluate CHL tightness without ligament damage as well as to augment and monitor stretching intensity. To find the optimal stretching direction, the glenohumeral joint was stretched from the neutral position into 5 directions sequentially under pressure-monitoring: flexion, extension [EX], external rotation [ER], EX+ER, and EX+ER+adduction [AD] directions.

MAIN OUTCOME MEASUREMENTS

CHL tightness was determined by a surrogate parameter, the additional pressure created by the overlying CHL. The pressure increase (ΔP_str) by a specific directional stretch was considered as the stretching intensity.

RESULTS

ΔP_str by the 5 directions were mean (standard deviation) values of 0.03 ± 0.07 atm, 0.87 ± 1.31 atm, 1.13 ± 1.36 atm, 1.49 ± 1.32 atm, and 2.10 ± 1.70 atm, respectively, revealing the highest ΔP_str by the EX+ER+AD stretch (P < .05). The balloon pressure by the overlying CHL was decreased from 0.45 ± 0.35 atm to 0.18 ± 0.14 atm (P = .012) before and after the stretching manipulation.

CONCLUSIONS

EX+ER+AD of the glenohumeral joint resulted in the greatest increase in balloon pressure, implying that it could be the most effective stretching direction. A series of stretching manipulations assisted with an underlying pressure balloon were capable of decreasing CHL tightness. With further development and modification, high-pressure balloon-assisted stretching can be a potential therapeutic option to release tight CHL, including the advantage of augmenting and monitoring stretching intensity.

LEVEL OF EVIDENCE

II.

Ultrasonographic measurement of the axillary recess thickness in an asymptomatic shoulder

Purpose

The purpose of this study was to measure the axillary recess (AR) thickness in an asymptomatic shoulder by using ultrasonography (US) and to analyze the factors affecting it.

Methods

We recruited 141 patients (52 males; 89 females; age, 57.7±9.9 years) with unilateral shoulder pain and performed US on the unaffected shoulder. Two physiatrists measured the AR thickness of the unaffected shoulder independently. All patients were examined in an upright sitting position with 90° shoulder abduction. The ultrasonographic transducer was placed longitudinally on the mid-axillary line and along the long axis of the humeral shaft. The factors affecting the AR thickness values were analyzed, and intra-class correlation coefficients were used for assessing the reproducibility of each measurement.

Results

The intrarater reliability values for the two physiatrists were 0.98 and 0.96, respectively. The inter-rater reliability of the mean AR thickness measurements was 0.91. The mean AR thickness in all subjects, males, and females was 2.8±0.6 mm, 3.1±0.6 mm, and 2.6±0.5 mm (P<0.01), respectively. No difference between the left and the right sides (males, P=0.086; females, P=0.535) or between the dominant and the non-dominant sides (males, P=0.173; female, P=0.244) was found. The AR thickness correlated positively with the height (r=0.313, P<0.01) and the weight (r=0.319, P<0.01). However, it did not correlate with the body mass index (r=0.152, P=0.077) or the age (r=-0.056, P=0.515).

Conclusion

US measurements of the AR thickness in asymptomatic shoulders demonstrated excellent intrarater and inter-rater reliabilities. The AR thickness showed anatomical variation with sex, height, and weight.

The pathophysiology associated with primary (idiopathic) frozen shoulder: A systematic review

Background

Frozen shoulder is a common yet poorly understood musculoskeletal condition, which for many, is associated with substantial and protracted morbidity. Understanding the pathology associated with this condition may help to improve management. To date this has not been presented in a systematic fashion. As such, the aim of this review was to summarise the pathological changes associated with this primary frozen shoulder.

Methods

Databases: Medline, Embase, CINAHL, AMED, BNI and the Cochrane Library, were searched from inception to 2nd May, 2014. To be included participants must not have undergone any prior intervention. Two reviewers independently conducted the; searches, screening, data extraction and assessment of Risk of Bias using the Cochrane Risk of Bias Assessment Tool for non-Randomised Studies of Interventions (ACROBAT-NRSI). Only English language publications reporting findings in humans were included. The findings were summarised in narrative format.

Results

Thirteen observational studies (involving 417 shoulders) were included in the review. Eight studies reported magnetic resonance imaging or arthrography findings and 5 recorded histological findings. When reported mean ages of the participants ranged from 40.0 to 59.8 years. Duration of symptoms ranged from 0 to 30 months. The majority of studies (n = 7) were assessed to be of moderate risk of bias, two studies at high risk and the remaining four were rated as low risk of bias. Study characteristics were poorly reported and there was widespread variety observed between studies in respect of data collection methods and inclusion criteria employed. Pathological changes in the anterior shoulder joint capsule and related structures were commonly reported. Imaging identified pathological changes occurring in the coracohumeral ligament, axillary fold and rotator interval. Obliteration of the subcoracoid fat triangle also appeared to be pathognomonic. Histological studies were inconclusive but suggested that immune, inflammatory and fibrotic changes where associated with primary frozen shoulder.

Conclusions

This systematic review presents a summary of what is currently known about the tissue pathophysiology of primary frozen shoulder. Further studies that use standardised inclusion and exclusion criteria and investigate changes in naïve tissue at different stages of the condition are required.