Predictive findings on magnetic resonance imaging in patients with symptomatic acromioclavicular osteoarthritis

Bone marrow edema in the acromioclavicular joint after arthroscopic rotator cuff repair

BACKGROUND

Bone marrow edema (BME) in the acromioclavicular joint (ACj) may occur after arthroscopic rotator cuff repair (ARCR), resulting in persistent postoperative ACj pain. We investigated the incidence and clinical characteristics of BME in ACj after ARCR.

METHODS

Patients exhibiting ACj-related symptoms prior to ARCR surgery, no BME in the ACj on MRI, and an ability to undergo 2-year postoperative physical and MRI examinations of the ACj were included. Patients who underwent distal clavicle resection or osteophyte resection below the ACj and those unable to achieve primary repair of the rotator cuff were excluded. MRI evaluation was performed preoperatively and at 3, 6, 12, and 24 months postoperatively. Patients who showed BME in ACj on fat-suppressed T2 MRI at 24 months postoperatively were classified into the BME + group, and those with no BME were classified into the BME- group. Patient background, operation time, Japanese Orthopedic Association (JOA) score, re-tear rate, ACj tenderness, and cross-body adduction test were compared between groups. In addition, we examined the time of occurrence of BME.

RESULTS

A total of 345 ARCRs were performed during the study period. After the exclusion of 114 shoulders, the remaining 231 shoulders were included in this study. There were 208 cases in the BME- group and 23 cases in the BME + group. The incidence of BME was 9.96 %. Although the JOA scores of both groups showed a significant improvement postoperatively compared to preoperatively, there was no significant difference between the two groups. In terms of re-tear, there was 1 case in the BME + group and 7 in the BME- group. Positive ACj tenderness and cross-body adduction test were significantly higher in the BME + group (P < 0.001). BME occurred in 6 cases at 3 months, 9 cases at 6 months, and 8 cases at 1 year postoperatively. None of the patients developed BME at more than 1 year postoperatively. BME was observed on MRI in all cases at 2 years postoperatively.

CONCLUSIONS

The rate of occurrence of BME in the ACj after ARCR was 9.96 %. Patients with BME were significantly more likely to have ACj tenderness and positive cross-body adduction test. BME in the ACj often occurs within 6 months to 1 year after ARCR of small-to-medium rotator cuff tears, suggesting a relationship with postoperative functional improvement of the shoulder joint. The ACj should be considered as a potential site of persistent pain after ARCR for small-to-medium rotator cuff tears.

Anatomical variants of the acromioclavicular joint influence its visibility in the standard MRI protocol in patients aged 18-31 years

Purpose

Visualization of a structure in orthogonal planes is essential for correct radiological assessment. The aim was to assess the utility of the standard MRI protocol for the shoulder in the assessment of the acromioclavicular joint (ACJ).

Methods

A total of 204 MRI scans of the shoulder were re-reviewed. Visibility of the ACJ in orthogonal planes was assessed, and the type of acromion and the angle between the ACJ and the glenoid cavity were assessed by two observers.

Results

Agreement in the assessment of ACJ visibility was moderate to substantial. The ACJ was visible in the three anatomical views in 48% (confidence interval [CI] 95% = [41–54%]) of the examinations, and no significant difference regarding gender or age was noticed. The mean angle between the ACJ and the glenoid cavity was 41.12 deg. CI95% = (39.72, 42.53) in the axial plane, 33.39 deg. CI95% = (31.33, 35.45) in the coronal plane and 52.49 deg. CI95% = (50.10, 54.86) in the sagittal plane. When the ACJ was visible in the sagittal and axial planes, significant differences were noticed in the remaining planes (p < .05).

Conclusion

Anatomical variations of the ACJ influence its visibility in the standard MRI protocol for examining the shoulder, making this protocol insufficient for ACJ assessment in the examined population.

Bony Edema and Clinical Examination Findings Predict the Need for Distal Clavicle Excision at the Time of Shoulder Arthroscopy

Background: Deciding to perform a distal clavicle excision for acromioclavicular joint arthritis, especially in conjunction with other arthroscopic shoulder procedures, is challenging for surgeons. Studies have reported mixed results on the value of magnetic resonance imaging (MRI) in decision making. Purpose: We sought to correlate MRI findings with clinical symptoms and the surgeon's decision to perform a distal clavicle excision. Methods: We compared MRI, clinical examination, and MRI findings of 200 patients who underwent distal clavicle excision for symptomatic acromioclavicular joint arthritis with 200 patients who underwent arthroscopic shoulder procedures for other reasons. Univariate statistics were used to determine correlations between physical examination findings, MRI findings, and the decision to perform distal clavicle excision. A binary logistic regression model was used to determine independent predictors of need for distal clavicle excision. Results: There was no difference in mean age, sex, and race between groups. Advanced acromioclavicular joint osteoarthritis was strongly correlated with positive physical examination findings. Bony edema correlated strongly with tenderness at the acromioclavicular joint but not pain with cross-body adduction testing. There was no association between higher MRI grade of osteoarthritis and the need for distal clavicle excision. Regression analysis identified both physical examination findings and bony edema on MRI as independent predictors of the need for distal clavicle excision. Conclusion: In the setting of positive clinical examination findings and bony edema of the distal clavicle, surgeons should feel reassured that distal clavicle excision is likely indicated.

Percutaneous distal clavicle excision for acromioclavicular joint arthritis: our experience and early results of a novel surgical technique

PURPOSE

Symptomatic acromioclavicular joint (ACJ) osteoarthritis causes pain and limitations in activities of daily living. Open and arthroscopic distal clavicle excision techniques have been described with good outcomes. However, both techniques have their own sets of advantages and disadvantages. This study describes a novel technique of percutaneous distal clavicle excision for symptomatic ACJ osteoarthritis and our two-year results.

METHODS

Fifteen consecutive patients underwent percutaneous distal clavicle excision for ACJ arthritis. These patients had failed a trial of conservative treatment. The ACJ was confirmed as the pain generator with an intraarticular steroid/lignocaine injection, and shoulder MRI was used to exclude alternative pain generators in the shoulder. They had a minimum of two years of follow-up.

RESULTS

At a mean of 26.8 months postoperatively, the mean VAS pain score was 0, and the mean Constant score for the shoulder was 87.3 points (range 50-94), which corresponded to 1 good, 1 very good and 13 excellent results. The mean SF-36 score was 94.9 points (range 65-100). There were statistically significant improvements in the VAS scores, Constant shoulder scores and SF-36 scores at one year and two years of follow-up (p < 0.05). Three unique complications, namely subcutaneous emphysema, "missing" of the distal clavicle and thermal skin injury, were encountered. Our surgical technique has since been modified to circumvent these complications.

CONCLUSION

Our novel technique of percutaneous distal clavicle excision yields a 93.3% good-to-excellent results based on the Constant shoulder score and durable pain relief based on VAS at two years.

AC joint osteoarthritis: The role of genetics. An MRI evaluation of asymptomatic elderly twins

PURPOSE

The anatomy of the articular surfaces has historically identified as major responsible for acromioclavicular joint osteoarthritis (ACJO). On the other side, the almost 100% prevalence of ACJO in subjects over 50 years old seems to suggest a multifactorial etiology. We compared ACJO between asymptomatic elderly monozygotic (MZ) and dizygotic (DZ) twins to investigate the influence of genetics and environmental factors.

MATERIALS AND METHODS

Thirty pairs of twins [15MZ-15DZ; mean age (SD): 63.70 (3.31); range: 53-72] were retrospectively enrolled. ACJO was evaluated on MRI through a 4-grade severity scale and ACJ configuration was assessed. Information regarding work activity were obtained. Heritability index was calculated.

RESULTS

The intraclass correlation coefficient (ICC) value of 0.868 (95% CI; 0.798 to 0.917). An ICC values of 0.889 (95% CI; 0.798 to 0.944) and 0.843 (95% CI, 0.712 to 0.920) were found in the MZ and DZ groups, respectively. The polychoric correlation was 0.857 in the MZ twins and 0.757 in the DZ twins. The calculated heritability index was 0.20 (20%), and the contribution of the shared environment (c2) and unique environment (e2) was 0.66 (66%) and 0.14 (14%), respectively. No relationship between job types and ACJO in both the total cohort (r = 0.089; p = 0.499) and in the monozygotic (r = 0.247; p = 0.187) and the dizygotic twin groups (r = -0.084; p = 0.658) was found.

CONCLUSIONS

The role of genetics on ACJO accounts for only 20%; a specific anatomical configuration of the articular surfaces only partially acts on the development of joint osteoarthritis. Environmental factors have the greatest impact.

LEVEL OF EVIDENCE

IV.

Histologic and magnetic resonance image evaluation in acromioclavicular joint osteoarthritis

Introduction

Little is known about the development of specific acromioclavicular joint osteoarthritis. Its histologic alterations are controversial, and radiologic alterations are seen in asymptomatic people. The objective of this study was to evaluate histologically the distal clavicle subchondral bone and to analyze magnetic resonance images in patients with painful and nonpainful acromioclavicular joint osteoarthritis.

Methods

An observational, analytical, and cross-sectional study with a control group was conducted. Between August 2018 and June 2019, we analyzed a total of 41 patients. Group 1 consisted of patients with pain in the acromioclavicular joint (symptomatic osteoarthritis), and group 2 consisted of patients without pain in the acromioclavicular joint (asymptomatic osteoarthritis).

Results

Twelve of the 15 patients with acromioclavicular joint pain (group 1) were female, 13 presented distal clavicle edema on magnetic resonance imaging, and 9 had subchondral bone edema on histologic examination. Patients with acromioclavicular joint pain had longer shoulder pain duration than patients without pain. Women were more likely to have acromioclavicular joint pain compared with men. Patients with edema on magnetic resonance imaging showed a greater chance of presenting pain in the acromioclavicular joint in comparison with patients without edema.

Conclusion

Women had a higher chance of presenting with acromioclavicular joint pain than men. Patients with edema on magnetic resonance imaging were more likely to present with pain than patients without edema. Patients with acromioclavicular joint pain had longer shoulder pain duration than patients without pain, and subchondral bone edema on histologic examination was more frequent in patients with pain.

Effectiveness of new nerve blocks method on the articular branches of the suprascapular and subscapular nerves to treat shoulder pain

To evaluate the effectiveness and safety of performing nerve blocks on the articular branches of the suprascapular and subscapular nerves for the treatment of shoulder pain caused by various pathologies.Fifty-two patients with shoulder pain were included in this study. Suprascapular and subscapular nerve blocks were performed with 2.5 mL anesthetic solution (2 mL of 0.5% bupivacaine and 0.5 mL of 2 mg/mL dexamethasone). The subjects were evaluated before the procedure and 1, 3, and 6 months afterward by means of the numeric rating scale and the shoulder pain and disability index. A post-injection pain reduction of >50% and <50% was considered a positive and negative response to the blocks, respectively.After nerve blocks, the mean numeric rating scale and shoulder pain and disability index scores were significantly reduced from pre-injection values, and this effect persisted for 6 months after injection. The positive and negative response groups consisted of 31 (60%) and 21 (40%) patients, respectively. The positive response group showed significantly better outcomes on the numeric rating scale and shoulder pain and disability index compared with the negative response group. No patients reported adverse effects either during or after the procedure.Performing nerve blocks on the articular branches of the suprascapular and subscapular nerves resulted in positive outcomes for shoulder pain patients. Regardless of shoulder pathology, this new injection method can be safely used in shoulder pain patients.

The relationship of the acromion to the distal clavicle in normal and symptomatic degenerated acromioclavicular joints

INTRODUCTION

Although degenerative osteoarthritis of the acromioclavicular joint is a common finding on technical investigations, not every patient experiences pain or function loss. The difference between symptomatic and asymptomatic patients is currently not elucidated. Therefore, we want to investigate the acromioclavicular relationship in normal, asymptomatic, and symptomatic degenerated ACJ.

MATERIALS AND METHODS

84 normal ACJ, 39 asymptomatic degenerated ACJ, and 30 symptomatic degenerated ACJ were 3D reconstructed. The morphological dimensions and the relationship of the acromion and distal clavicle were measured using computational software. The reproducibility of this technique was evaluated using inter- and intra-observer reliability.

RESULTS

The mean anteroposterior and superoinferior distance of both the clavicle and acromion was significantly larger in asymptomatic and symptomatic degenerative ACJ compared to the normal ACJ (p < 0.001). In symptomatic osteoarthritic ACJ, both the anterior and posterior borders of the acromion were significantly more anterior to the borders of the clavicle than in the normal group and asymptomatic group (p < 0.001). Subsequent ROC curve analysis resulted in a sensitivity of 86.7% and a specificity of 88.6% for anterior subluxation of the ACJ. This technique showed an excellent inter- and intra-observer reliability.

CONCLUSIONS

In patients with degenerative ACJ, both the distal clavicle and acromion are enlarged. In asymptomatic patients, the AC relationship is the same as in normal patients, in contrast, in patients with symptomatic degenerative ACJ, the acromion is subluxated anteriorly compared to the clavicle.

Acromioclavicular Joint: What to Look for

Acromioclavicular joint (ACJ) pathology is a common source of shoulder girdle pain, frequently coexisting with and sharing overlapping clinical features of rotator cuff and glenohumeral articular lesions. ACJ trauma and osteoarthritis dominate clinical presentation; however, an array of pathologies can affect the joint. MR imaging of the ACJ is a powerful secondary diagnostic tool in early diagnosis of ACJ pathology and in accurate assessment of ACJ injuries, helping to resolve clinically challenging cases and allowing for individualized treatment planning. Knowledge of ACJ anatomy, biomechanics, and pathology is fundamental to interpreting and providing a clinically relevant ACJ MR imaging report.