MRI features of the acromioclavicular joint that predict pain relief from intraarticular injection

A systematic review of the treatment of primary acromioclavicular joint osteoarthritis

Background

This systematic review aims to comprehensively summarise and present the available evidence for the treatment of primary acromioclavicular joint (ACJ) osteoarthritis (OA).

Methods

Five databases were searched for studies investigating the management of ACJ OA. Included were studies with participants with clinical/radiological signs of primary ACJ OA, an intervention and included a functional outcome measure.

Results

Forty-eight studies were included. Treatments consisted of physiotherapy (n = 1 study), medical only (n = 11) and operative management (n = 36). Operative studies included five comparative trials - physiotherapy versus surgery (n = 1) and open versus arthroscopic resection (n = 4). A total of 1902 shoulders were treated for ACJ OA, mean age (51 years), 58% male and mean follow-up (28.5 months). Treatment with injection showed a mean improvement of 50% in pain levels at follow-up (mean = 7.5 months). The commonest surgical procedure was arthroscopic excision of the distal clavicle and operative studies averaged 6 months of conservative management and a mean functional outcome of 87.8%.

Conclusion

Studies varied in indication, intervention and quality but it did not provide evidence that both non-operative and operative interventions are effective. There was no significant difference between open or arthroscopic distal clavicle excision (DCE). Participants having between 0.5 and 2 cm of clavicle excised had good outcomes and those requiring concomitant shoulder procedures had similarly good outcomes.

Clinical Diagnosis of Common Overlapping Shoulder and Cervical Spine Disorders: A Review of Current Evidence

» Pain in the shoulder is a common orthopaedic complaint that can be caused by shoulder or neck pathologies.» Shoulder and neck pathologies often coexist, among which one may be a predisposing factor for the other.» History, physical examination, and diagnostic injections can be used to discern the cause of shoulder pain and guide treatment.

Management of Acromioclavicular Joint Injuries: A Historic Account

There has been a rapid evolution in best practice management of acromioclavicular (AC) joint injuries. AP, Zanca, scapular Y, and dynamic axillary radiographic views provide optimal visualization of the joint and may assess for the presence of horizontal AC instability. Severity of AC joint pathology is classified according to the 6-tier Rockwood scoring system. Over 160 surgical techniques have been described for AC joint repair and reconstruction in the last decade; as a result, determining the optimal treatment algorithm has become increasingly challenging secondary to the lack of consistently excellent clinical outcomes.

Usefulness of the acromioclavicular joint cross-sectional area as a diagnostic image parameter of acromioclavicular osteoarthritis

BACKGROUND

Acromioclavicular joint (ACJ) space narrowing has been considered to be an important diagnostic image parameter of ACJ osteoarthritis (ACJO). However, the morphology of the ACJ space is irregular because of osteophyte formation, subchondral irregularity, capsular distention, sclerosis, and erosion. Therefore, we created the ACJ cross-sectional area (ACJCSA) as a new diagnostic image parameter to assess the irregular morphologic changes of the ACJ.

AIM

To hypothesize that the ACJCSA is a new diagnostic image parameter for ACJO.

METHODS

ACJ samples were obtained from 35 patients with ACJO and 30 healthy individuals who underwent shoulder magnetic resonance (S-MR) imaging that revealed no evidence of ACJO. Oblique coronal, T2-weighted, fat-suppressed S-MR images were acquired at the ACJ level from the two groups. We measured the ACJCSA and the ACJ space width (ACJSW) at the ACJ on the S-MR images using our imaging analysis program. The ACJCSA was measured as the cross-sectional area of the ACJ. The ACJSW was measured as the narrowest point between the acromion and the clavicle.

RESULTS

The average ACJCSA was 39.88 ± 10.60 mm² in the normal group and 18.80 ± 5.13 mm² in the ACJO group. The mean ACJSW was 3.51 ± 0.58 mm in the normal group and 2.02 ± 0.48 mm in the ACJO group. ACJO individuals had significantly lower ACJCSA and ACJSW than the healthy individuals. Receiver operating characteristic curve analyses demonstrated that the most suitable ACJCSA cutoff score was 26.14 mm², with 91.4% sensitivity and 90.0% specificity.

CONCLUSION

The optimal ACJSW cutoff score was 2.37 mm, with 88.6% sensitivity and 96.7% specificity. Even though both the ACJCSA and ACJSW were significantly associated with ACJO, the ACJCSA was a more sensitive diagnostic image parameter.

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.

Acromioclavicular joint arthritis is not an indication for routine distal clavicle excision in arthroscopic rotator cuff repair

PURPOSE

To evaluate the significance of untreated primary acromioclavicular joint (ACJ) osteoarthritis, encountered during arthroscopic rotator cuff repair (RCR), as a cause of persistent symptomatology and need for revision surgery.

METHODS

In a cohort of 811 consecutive patients older than 55 years who underwent RCR, the effect of primary ACJ osteoarthritis presence was prospectively examined. A total of 497 patients with mild/moderate and severe ACJ osteoarthritis based on preoperative MRI evaluation were allocated to Group A (n = 185, symptomatic ACJ) and Group B (n = 312, asymptomatic ACJ). Distal clavicle excision was not performed regardless of the presence of pain. The minimum follow-up was 28 months (28-46). The visual analogue scale (VAS) pain scores were assessed for ACJ pain on palpation, the cross body adduction test, the Constant-Murley, and the American Shoulder and Elbow Surgeons (ASES).

RESULTS

The overall loss to follow-up rate was 3.82% (19 patients: 11 in Group A and eight in Group B). The mean ASES score at the latest follow-up was 91.16 ± 9.3 and 92.37 ± 10.44 in Groups A and B, respectively, and the mean Constant-Murley score was 96.36 ± 5.7 and 95.76 ± 4.6 in Groups A and B, respectively. There was no statistical significance between regarding both scores. Localised ACJ pain on palpation and pain on cross body adduction were diminished in both the symptomatic and asymptomatic group. There were five cases (1%: two in Group A and three in Group B) with persistent ACJ pain who had failed the conservative treatment, and ACJ excision was necessary to alleviate the symptoms. All revision operations were uncomplicated with symptom resolution.

CONCLUSION

Untreated ACJ osteoarthritis, symptomatic or not, encountered during arthroscopic RCR is associated with a low percentage of failure. Routine distal clavicle excision is not absolutely necessary, even in patients with symptomatic ACJ osteoarthritis.

LEVEL OF EVIDENCE

II, Prospective cohort study.

Magnetic resonance imaging of the shoulder

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

Imaging of the Acromioclavicular Joint: Anatomy, Function, Pathologic Features, and Treatment

The acromioclavicular joint is an important component of the shoulder girdle; it links the axial skeleton with the upper limb. This joint, a planar diarthrodial articulation between the clavicle and the acromion, contains a meniscus-like fibrous disk that is prone to degeneration. The acromioclavicular capsule and ligaments stabilize the joint in the horizontal direction, while the coracoclavicular ligament complex provides vertical stability. Dynamic stability is afforded by the deltoid and trapezius muscles during clavicular and scapular motion. The acromioclavicular joint is susceptible to a broad spectrum of pathologic entities, traumatic and degenerative disorders being the most common. Acromioclavicular joint injury typically affects young adult males and can be categorized by using the Rockwood classification system as one of six types on the basis of the direction and degree of osseous displacement seen on conventional radiographs. MRI enables the radiologist to more accurately assess the regional soft-tissue structures in the setting of high-grade acromioclavicular separation, helping to guide the surgeon's selection of the appropriate management. Involvement of the acromioclavicular joint and its stabilizing ligaments is also important for understanding and classifying distal clavicle fractures. Other pathologic processes encountered at this joint include degenerative disorders; overuse syndromes; and, less commonly, inflammatory arthritides, infection, metabolic disorders, and developmental malformations. Treatment options for acromioclavicular dysfunction include conservative measures, resection arthroplasty for recalcitrant symptoms, and surgical reconstruction techniques for stabilization after major trauma.

Acromioclavicular osteoarthritis and shoulder pain: a review of the role of ultrasonography

Acromioclavicular joint osteoarthritis is often a cause of shoulder pain. On the other hand, imaging frequently leads to such a diagnosis, especially in elderly patients, and some authors believe it to have a poor correlation with the clinical picture. It is, however, widely accepted that such a condition can be the cause of rotator cuff impingement. In the case of shoulder pain, it is important to distinguish between symptomatic acromioclavicular osteoarthritis and other causes, especially rotator cuff pathology, which is more common. Sometimes, the clinical picture does not allow for differential diagnosis; in these cases, the injection of a local anesthetic into the acromioclavicular joint or into the subacromial bursa can be of great help. Ultrasonography can easily detect acromioclavicular osteoarthritis and rotator cuff pathology, and it is highly effective in guiding the articular or bursal injection of a local anesthetic to assess the origin of the pain. In addition, in conservative therapy, ultrasonography can guide the articular or bursal injection of corticosteroids and hyaluronic acid.

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.

Shoulder measurements on MRI: Statistical analysis of patients without and with rotator cuff tears and predictive modeling

This study aims to determine significant differences between various measurements of shoulder structures and relationships in patients with and without rotator cuff tears and identify a subset of these measurements that may merit further investigation. Shoulder MRIs of 120 patients with rotator cuff tears (RCT group) and 80 patients with normal examinations (No RCT group) were retrospectively identified. Numerous measurements of shoulder anatomy and relationships and pathology characterization were performed for each study. The mean and ranges of measurements for each group were identified, and P-values were calculated to assess differences between the two groups. Classification and Regression Tree (CART) identified prediction models for separating the two groups based on these shoulder MRI measurements. Statistically significant differences were observed for 9 of 18 of the shoulder measurements between the two groups (P < 0.05). Using long head of biceps tendon tear, tendinosis, and subacromial-subdeltoid bursal fluid, the prediction model from CART demonstrated 99.5% accuracy in separating the two groups. Subacromial distance, subacromial spur size, and acromioclavicular osteophyte could also separate the two groups with 97.5% accuracy. Other measures less commonly associated with impingement and rotator cuff tears could also be used to separate the two groups with up to 81.5% accuracy. This study introduces new measures and clarifies ranges for existing measurements on shoulder MRI. Abnormalities of some of these measurements may be associated with subacromial impingement, and combinations of these parameters may be useful for separating patients with or without rotator cuff tears. Clin. Anat. 33:173-186, 2020. © 2019 Wiley Periodicals, Inc.

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

BACKGROUND

A magnetic resonance imaging (MRI) scan of the shoulder can have added value in diagnosing symptomatic osteoarthritis of the acromioclavicular (AC) joint. Specific MRI signs have been recognized but not analyzed extensively before. This study aims to identify predictive MRI signs in patients with symptomatic AC osteoarthritis.

METHODS

The MRI scans of 70 patients with symptomatic AC osteoarthritis were compared with those of 70 patients with subacromial pain syndrome and no clinical signs of symptomatic AC osteoarthritis. Seven variables were evaluated on the MRI scans of the AC joint: joint space narrowing, inferior osteophytes, joint effusion, osteolysis, bone marrow edema, impression on the supraspinatus, and inferior joint distension. Logistic regression analysis of these variables was performed.

RESULTS

The presence of inferior osteophytes, bone marrow edema, impression on the supraspinatus, and inferior joint distension was individually associated with symptomatic AC osteoarthritis. Bone marrow edema was observed only in patients with symptomatic AC osteoarthritis. Multivariate analysis showed a significant association between inferior joint distension, as well as impression on the supraspinatus muscle, and symptomatic AC osteoarthritis. The area under the receiver operating characteristic curve in the multivariate logistic model was 0.839 (95% confidence interval, 0.771 to 0.907). Interobserver and intraobserver variability showed good to excellent κ values (range, 0.68 to 0.88).

CONCLUSION

We identified predictive MRI signs in patients with symptomatic AC osteoarthritis. These findings, including bone marrow edema, inferior joint distension, and impression on the supraspinatus muscle, showed good discriminative ability. They are practical and easy to use and can assist the physician in diagnosing symptomatic AC osteoarthritis.

Diagnostic Injections About the Shoulder

Injections about the shoulder serve diagnostic as well as therapeutic purposes. Diagnosis of shoulder conditions, such as rotator cuff tears, acromioclavicular joint pathology, subacromial impingement or anterolateral pain syndrome, glenohumeral joint pathology, suprascapular nerve entrapment, and biceps tendon pathologies, is often complicated by concomitant conditions with overlapping symptoms and by inconclusive physical examination and imaging results. Injections of anesthetic agents can often help clinicians locate the source of pain. However, technique and accuracy of needle placement can vary by route. Accuracy is often improved with the use of ultrasonography guidance, although studies differ on the benefits of guided versus unguided injection.

Diagnostic Accuracy of Clinical Examination and Imaging Findings for Identifying Subacromial Pain

BACKGROUND

The diagnosis of subacromial pathology is limited by the poor accuracy of clinical tests for specific pathologies. The aim of this study was to estimate the diagnostic accuracy of clinical examination and imaging features for identifying subacromial pain (SAP) defined by a positive response to diagnostic injection, and to evaluate the influence of imaging findings on the clinical diagnosis of SAP.

METHODS AND FINDINGS

In a prospective, diagnostic accuracy design, 208 consecutive patients presenting to their primary healthcare practitioner for the first time with a new episode of shoulder pain were recruited. All participants underwent a standardized clinical examination, shoulder x-ray series and diagnostic ultrasound scan. Results were compared with the response to a diagnostic block of xylocaineTM injected into the SAB under ultrasound guidance using ≥80% post-injection reduction in pain intensity as the positive anaesthetic response (PAR) criterion. Diagnostic accuracy statistics were calculated for combinations of clinical and imaging variables demonstrating the highest likelihood of a PAR. A PAR was reported by 34% of participants. In participants with no loss of passive external rotation, combinations of three clinical variables (anterior shoulder pain, strain injury, absence of symptoms at end-range external rotation (in abduction)) demonstrated 100% specificity for a PAR when all three were positive (LR+ infinity; 95%CI 2.9, infinity). A full-thickness supraspinatus tear on ultrasound increased the likelihood of a PAR irrespective of age (specificity 98% (95%CI 94, 100); LR+ 6.2; 95% CI 1.5, 25.7)). Imaging did not improve the ability to rule-out a PAR.

CONCLUSION

Combinations of clinical examination findings and a full-thickness supraspinatus tear on ultrasound scan can help confirm, but not exclude, the presence of subacromial pain. Other imaging findings were of limited value for diagnosing SAP.

Successful injection of the acromioclavicular joint with use of ultrasound: anatomy, technique, and follow-up

BACKGROUND

Injection into the acromioclavicular (AC) joint is often inaccurate (approximately 50%) even in experienced hands. In light of new anatomic observations, we evaluate accuracy of an innovative ultrasound-guided method and follow the clinical course of successful therapeutic injections.

METHOD

Relevant anatomy was investigated in 200 three-dimensional computed tomography scans, 100 magnetic resonance images, and 14 cadavers. Baseline measurements of joint depth and width were performed ultrasonically in 100 normal volunteers; 50 symptomatic patients were injected. Uniquely in a clinical ultrasound study, injection success was documented by arthrography. Outcomes after concomitant steroid instillation were observed for 6 months by visual analog scale (VAS) scores and pain provocation test results.

RESULTS

Anatomic studies showed that the widest area for joint penetration was anterior superior. Injection success rate was 96%, overwhelmingly on the first needle pass. Shallow joint depth allowed access with a standard 3-cm needle. Joint width diminished with age but did not reduce injection success. Cadaveric joints admitted 1.2 ± 0.5 mL, but fluid ingress was initially blocked by soft tissues in one third of both cadaveric and clinical cases. Diligent follow-up after steroid injection showed sustained pain relief in the majority with isolated AC disease but significantly less in those with concomitant shoulder disorders.

CONCLUSION

This high level of clinical injection success, irrefutably substantiated with arthrography, has not been previously demonstrated. The anterior superior aspect of the joint is the preferred place for entry. Initial intra-articular blockage to fluid inflow is common but can be surmounted. Encouraging 6-month results of steroid instillation in isolated AC disease do not apply to patients with coexisting shoulder pathologic processes.

Clinical identifiers for early-stage primary/idiopathic adhesive capsulitis: are we seeing the real picture?

BACKGROUND

Adhesive capsulitis is often difficult to diagnose in its early stage and to differentiate from other common shoulder disorders.

OBJECTIVE

The aim of this study was to validate any or all of the 8 clinical identifiers of early-stage primary/idiopathic adhesive capsulitis established in an earlier Delphi study.

DESIGN

This was a cross-sectional study.

METHODS

Sixty-four patients diagnosed with early-stage adhesive capsulitis by a physical therapist or medical practitioner were included in the study. Eight active and 8 passive shoulder movements and visual analog scale pain scores for each movement were recorded prior to and immediately following an intra-articular injection of corticosteroid and local anesthetic. Using the local anesthetic as the reference standard, pain relief of ≥70% for passive external rotation was deemed a positive anesthetic response (PAR).

RESULTS

Sixteen participants (25%) demonstrated a PAR. Univariate logistic regression identified that of the proposed identifiers, global loss of passive range of movement (odds ratio [OR]=0.26, P=.03), pain at the end of range of all measured active movements (OR=0.06, P=.02), and global loss of passive glenohumeral movements (OR=0.23, P=.02) were associated with a PAR. Following stepwise removal of the variables, pain at the end of range of all measured active movements remained the only identifier but was associated with reduced odds of a PAR.

LIMITATIONS

The lack of a recognized reference standard for diagnosing early-stage adhesive capsulitis remains problematic in all related research.

CONCLUSIONS

None of the clinical identifiers for early-stage adhesive capsulitis previously proposed by expert consensus have been validated in this study. Clinicians should be aware that commonly used clinical identifiers may not be applicable to this stage.

[Magnetic resonance imaging of the shoulder: impingement and instability related abnormalities--update 2013]

Magnetic resonance imaging (MRI) plays an important role in the diagnosis and differentiation of numerous shoulder abnormalities and chronic shoulder pain. Important indications for MRI are assessment of the rotator cuff and the labrocapsular complex. The assessment of the rotator cuff muscles is crucial. The value of MR arthrography is discussed. The potential benefit of MR arthrography is the accurate evaluation of subtle rotator cuff abnormalities, shoulder instability-related lesions and the assessment of pathological conditions of the long biceps tendon. The following article describes the most common pathological findings of the shoulder joint and gives a description of the relevant findings for the orthopedic shoulder surgeon. The current article represents an update of an article previously published in 2006 with the same title (Zanetti and Saupe, Radiologe 46:79-89, 2006).

Degenerative joint disease of the acromioclavicular joint: a review

Osteoarthritis of the acromioclavicular (AC) joint is a common condition causing anterior or superior shoulder pain, especially with overhead and cross-body activities. This most commonly occurs in middle-aged individuals because of degeneration to the fibrocartilaginous disk that cushions the articulations. Diagnosis relies on history, physical examination, imaging, and diagnostic local anesthetic injection. Diagnosis can be challenging given the lack of specificity with positive physical examination findings and the variable nature of AC joint pain. Of note, symptomatic AC osteoarthritis must be differentiated from instability and subtle instability, which may have similar symptoms. Although plain radiographs can reveal degeneration, diagnosis cannot be based on this alone because similar radiographic findings can be seen in asymptomatic individuals. Nonoperative therapy can provide symptomatic relief, whereas patients with persistent symptoms can be considered for resection arthroplasty by open or arthroscopic technique. Both techniques have proven to provide predictable pain relief; however, each has its own unique set of potential complications that may be minimized with an improved understanding of the anatomical and biomechanical characteristics of the joint along with meticulous surgical technique.

A new test for acromio-clavicolar pathology

BACKGROUND

A prospective study was established to assess the sensitivity and specificity of the new Saccomanni (SAC) test for isolated AC pathology, and compare with 4 commonly used clinical tests.

MATERIALS AND METHODS

The Saccomanni (Sac) test is essentially the cross-adduction test, with the addition of attempted elevation against resistance. In a positive test, this results in some pain and the inability of the patient to maintain the arm in the adducted and elevated position against resistance. Fifty-eight patients with isolated AC joint symptoms were assessed in random order with the Saccomanni test and 4 other tests. A corticosteroid and local anaesthetic injection was administered into the AC joint space. The Saccomanni test and 4 other tests were then repeated following the injection. After the injection, a symptom free clinical examination was used as a measure of true positive tests.

STUDY DESIGN

Case series.

RESULTS

The SAC test showed a sensitivity of 98% and specificity is 91.7%. All 4 other tests were less sensitive.

CONCLUSION

The SAC test is a highly sensitive test in patients presenting with isolated AC related symptoms. This study is an innovation for clinical tests in the world. The primary aim of this study was to assess the diagnostic sensitivity of my newly described SAC test. From the present study, it can be concluded that the easy-to use SAC is a highly sensitive test to evaluate AC joint pathology, when compared to other standard tests.

CLINICAL RELEVANCE

Level III, Diagnostic Study of Nonconsecutive Patients.

The influence of ultrasound guidance in the rate of success of acromioclavicular joint injection: an experimental study on human cadavers

BACKGROUND

Injections of the acromioclavicular joint (ACJ) are performed routinely in patients with ACJ arthritis, both diagnostically and therapeutically. The aim of this prospective controlled study was to estimate the frequency of successful intra-articular ACJ injections with the aid of sonographic guidance versus non-guided ACJ injections.

MATERIALS AND METHODS

A total of 80 cadaveric ACJs were injected with a solution containing methylene blue and subsequently dissected to distinguish intra- from peri-articular injections. In 40 cases the joint was punctured with sonographic guidance, whereas 40 joints were injected in the control group without the aid of ultrasound.

RESULTS

The rate of successful intra-articular ACJ injection was 90% (36 of 40) in the guided group and 70% (28 of 40) in the non-guided group. Ultrasound was significantly more accurate for correct intra-articular needle placement (P = .025).

DISCUSSION

The use of ultrasound significantly improves the accuracy of ACJ injection.

The long term effect of an intra-articular injection of corticosteroids in the acromioclavicular joint

BACKGROUND

A prospective study was established to assess the effect of an intra-articular injection of corticosteroid and local anaesthetic into the acromioclavicular (AC) joint.

METHODS

Fifty-eight patients with isolated AC joint symptoms were included. Clinical tests were repeated immediately following the injection, as well as at 1-month follow-up. If symptoms failed to improve at this time, arthroscopic surgery was offered. All other patients were dismissed from standard care and contacted for this study. Both American Shoulder and Elbow Surgeons (ASES) and University of California at Los Angeles (UCLA) scores were obtained at final follow-up.

RESULTS

Sixteen patients had improved sufficiently. Between the 1 month and average final follow-up of 42 months, 1 patient had arthroscopic resection of the distal clavicle. Four of the 15 patients reported occasional mild pain. Average visual analogue scale (VAS) score for pain was 0.5 (0-3). Average ASES score was 94.1 (70-100) and average UCLA score was 33.9 (28-35).

DISCUSSION

Pain relief achieved with an injection into the AC joint has both a diagnostic and therapeutic value. The decrease of pain with clinical testing affirms the correct position of the injection. Only a minority of patients has sufficient pain relief from the injection at 1 month follow-up; however, this is sustained at the longer-term follow-up in the patients that have a positive reaction.

CONCLUSION

The diagnostic value of the injection of a local anaesthetic in the AC joint is immediate. Only 28% have a clear positive result at 1 month; but, this result is sustained at long-term follow-up. There were no complications.

A prospective study of shoulder pain in primary care: prevalence of imaged pathology and response to guided diagnostic blocks

BACKGROUND

The prevalence of imaged pathology in primary care has received little attention and the relevance of identified pathology to symptoms remains unclear. This paper reports the prevalence of imaged pathology and the association between pathology and response to diagnostic blocks into the subacromial bursa (SAB), acromioclavicular joint (ACJ) and glenohumeral joint (GHJ).

METHODS

Consecutive patients with shoulder pain recruited from primary care underwent standardised x-ray, diagnostic ultrasound scan and diagnostic injections of local anaesthetic into the SAB and ACJ. Subjects who reported less than 80% reduction in pain following either of these injections were referred for a magnetic resonance arthrogram (MRA) and GHJ diagnostic block. Differences in proportions of positive and negative imaging findings in the anaesthetic response groups were assessed using Fishers test and odds ratios were calculated a for positive anaesthetic response (PAR) to diagnostic blocks.

RESULTS

In the 208 subjects recruited, the rotator cuff and SAB displayed the highest prevalence of pathology on both ultrasound (50% and 31% respectively) and MRA (65% and 76% respectively). The prevalence of PAR following SAB injection was 34% and ACJ injection 14%. Of the 59% reporting a negative anaesthetic response (NAR) for both of these injections, 16% demonstrated a PAR to GHJ injection. A full thickness tear of supraspinatus on ultrasound was associated with PAR to SAB injection (OR 5.02; p < 0.05). Ultrasound evidence of a biceps tendon sheath effusion (OR 8.0; p < 0.01) and an intact rotator cuff (OR 1.3; p < 0.05) were associated with PAR to GHJ injection. No imaging findings were strongly associated with PAR to ACJ injection (p ≤ 0.05).

CONCLUSIONS

Rotator cuff and SAB pathology were the most common findings on ultrasound and MRA. Evidence of a full thickness supraspinatus tear was associated with symptoms arising from the subacromial region, and a biceps tendon sheath effusion and an intact rotator cuff were associated with an intra-articular GHJ pain source. When combined with clinical information, these results may help guide diagnostic decision making in primary care.

Clinical evaluation of acromioclavicular joint pathology: sensitivity of a new test

BACKGROUND

A prospective study was established to assess the sensitivity of the newly described Bell-van Riet (BvR) test for isolated AC pathology, and compare with 4 commonly used clinical tests.

MATERIALS AND METHODS

The BvR test is essentially the cross-adduction test, with the addition of attempted elevation against resistance. In a positive test, this results in some pain and the inability of the patient to maintain the arm in the adducted and elevated position against resistance. Fifty-eight patients with isolated AC joint symptoms were assessed in random order with the BvR test and 4 other tests. A corticosteroid and local anaesthetic injection was administered into the AC joint space. The BvR test and 4 other tests were then repeated following the injection. After the injection, a symptom free clinical examination was used as a measure of truly positive tests.

RESULTS

The BvR test showed a sensitivity of 98%. All 4 other tests were less sensitive.

CONCLUSION

The BvR test is a highly sensitive test in patients presenting with isolated AC related symptoms, and demonstrates AC joint pathology better than other accepted tests.

Surgical treatment for acromioclavicular joint osteoarthritis: patient selection, surgical options, complications, and outcome

Osteoarthritis is one of the most common causes of pain originating from the acromioclavicular (AC) joint. An awareness of appropriate diagnostic techniques is necessary in order to localize clinical symptoms to the AC joint. Initial treatments for AC joint osteoarthritis, which include non-steroidal anti-inflammatory drugs (NSAIDS) and corticosteroids, are recommended prior to surgical interventions. Distal clavicle excision, the main surgical treatment option, can be performed by various surgical approaches, such as open procedures, direct arthroscopic, and indirect arthroscopic techniques. When choosing the best surgical option, factors such as avoidance of AC ligament damage, clavicular instability, and post-operative pain must be considered. This article examines patient selection, complications, and outcomes of surgical treatment options for AC joint osteoarthritis.

Evidence-based radiology (part 2): Is there sufficient research to support the use of therapeutic injections into the peripheral joints?

INTRODUCTION

This review article addresses the best evidence currently available for the effectiveness of injection therapy for musculoskeletal conditions involving the peripheral joints. The research is presented by anatomical region and areas of controversy and the need for additional research are identified.

DISCUSSION

Randomized controlled trials, meta-analyses and systematic reviews are lacking that address the effectiveness of therapeutic injections to the sternoclavicular, acromioclavicular, ankle and foot joints. No research studies of any kind have been reported for therapeutic injections of the sternoclavicular joint. With the exception of the knee, possibly the hip and patients with inflammatory arthropathies, research does not unequivocally support the use of therapeutic joint injections for most of the peripheral joints, including the shoulder. Additionally, controversy exists in some areas as to whether or not corticosteroids provide better outcomes compared to local anesthetic injections alone.

CONCLUSION

When viscosupplementation injections are compared to corticosteroids in patients with osteoarthritis of the knee, the evidence supports the use of viscosupplementation for more prolonged improvement in outcomes, with corticosteroids being good for short-term relief.

Ironman triathletes: MRI assessment of the shoulder

OBJECTIVE

The objective of this paper was to demonstrate the prevalence of shoulder magnetic resonance imaging (MRI) abnormalities, including abnormal bone marrow signal at the acromioclavicular (AC) joint in symptomatic and asymptomatic Ironman Triathletes.

MATERIALS AND METHODS

The shoulders of 23 Ironman Triathletes, seven asymptomatic (group I) and 16 symptomatic (group II), were studied by MRI. A separate, non-triathlete group was evaluated specifically for AC joint marrow signal abnormalities to compare with the Ironman Triathletes.

RESULTS

Partial thickness tears of the rotator cuff, rotator cuff tendinopathy, and AC joint arthrosis were common findings in both groups of triathletes. Tendinopathy was the only finding that was more prevalent in the symptomatic group, but this was not a statistically significant difference (p = 0.35). There were no tears of the glenoid labrum seen in group I or II subjects. Of note is that 71% (5/7) of group I subjects and 62% (10/16) of group II subjects had increased signal changes in the marrow of the AC joint (p = 0.68). The comparison group showed a lower prevalence (35%, p = 0.06) of this finding.

CONCLUSIONS

No statistically significant difference was found among the findings for group 1, group 2, or the comparison group, although the difference between the comparison group and Ironman Triathletes approached statistical significance when evaluating for AC joint abnormal signal. Shoulder MRI of Ironman Triathletes should be interpreted with an appreciation of the commonly seen findings in asymptomatic subjects.

The long-term effectiveness of steroid injections in primary acromioclavicular joint arthritis: a five-year prospective study

We evaluated the long-term benefits of steroid injection in 25 shoulders in 20 consecutive patients (average age, 55 years) with primary acromioclavicular arthritis. Minimum follow-up was 5 years. The mean preinjection Constant score (61 points) improved at 6 months to 81 points, (mean difference, 19.36; P < .01). Improvement at 12 months (mean, 86 points) was also significant vs the 6-month score (P = .001). The mean score at 5 years (81 points) was a significant deterioration vs the 12-month score (P = .01) but still a significant improvement vs the preinjection scores (P < .0005). Younger patients had greater improvement in the objective score (range of movement and power; r = -0.47; P = .01), as did women (r = 0.405; P = .05). Local steroid injection is an effective treatment for primary isolated acromioclavicular arthritis. Improvement continues for at least 12 months. The benefit is felt up to 5 years. Pain relief tends to diminish long-term.

[The postsurgical rotator cuff: surgical techniques, clinical outcome, and MRI evaluation]

Surgical treatment of rotator cuff tears significantly reduces painful symptoms and improves functional capacity in many patients. However, despite recent advances, up to 25% of patients remain symptomatic after surgery. This has led to research into the reasons for these poor outcomes, including how to identify them with imaging methods and how to avoid them through new therapeutic approaches. Based on our clinical experience, we review the available treatment alternatives for rotator cuff tears, analyzing the main areas of controversy and the possible causes of unsatisfactory outcome after surgery. Furthermore, we review the expectations, difficulties, and requirements of diagnostic imaging in the follow-up of surgically treated rotator cuffs, with special emphasis on the MRI findings and their clinical impact.

Modic changes, possible causes and relation to low back pain

In patients with low back pain (LBP) it is only possible to diagnose a small proportion, (approximately 20%), on a patho-anatomical basis. Therefore, the identification of relevant LBP subgroups, preferably on a patho-anatomical basis, is strongly needed. Signal changes on MRI in the vertebral body marrow adjacent to the end plates also known as Modic changes (MC) are common in patients with LBP (18-58%) and is strongly associated with LBP. In asymptomatic persons the prevalence is 12-13%. MC are divided into three different types. Type 1 consists of fibro vascular tissue, type 2 is yellow fat, and type 3 is sclerotic bone. The temporal evolution of MC is uncertain, but the time span is years. Subchondral bone marrow signal changes associated with pain can be observed in different specific infectious, degenerative and immunological diseases such as osseous infections, osteoarthritis, ankylosing spondylitis and spondylarthritis. In the vertebrae, MC is seen in relation to vertebral fractures, spondylodiscitis, disc herniation, severe disc degeneration, injections with chymopapain, and acute Schmorl's impressions. The aim of this paper is to propose two possible pathogenetic mechanisms causing Modic changes. These are: A mechanical cause: Degeneration of the disc causes loss of soft nuclear material, reduced disc height and hydrostatic pressure, which increases the shear forces on the endplates and micro fractures may occur. The observed MC could represent oedema secondary to the fracture and subsequent inflammation, or a result of an inflammatory process from a toxic stimulus from the nucleus pulposus that seeps through the fractures. A bacterial cause: Following a tear in the outer fibres of the annulus e.g. disc herniation, new capilarisation and inflammation develop around the extruded nuclear material. Through this tissue it is possible for anaerobic bacteria to enter the anaerobic disc and in this environment cause a slowly developing low virulent infection. The MC could be the visible signs of the inflammation and oedema surrounding this infection, because the anaerobic bacteria cannot thrive in the highly aerobic environment of the MC type 1.

PERSPECTIVES

One or both of the described mechanisms can - if proven - be of significant importance for this specific subgroup of patients with LBP. Hence, it would be possible to give a more precise and relevant diagnosis to 20-50% of patients with LBP and enable in the development of efficient treatments which might be antibiotics, special rehabilitation programmes, rest, stabilizing exercise, or surgical fixation, depending on the underlying cause for the MC.

[MR imaging of the shoulder. Impingement and instability-related abnormalities]

In addition to the case history and the clinical examination, MR imaging has an important role in the diagnosis and differential diagnosis of numerous shoulder abnormalities and in the investigation of chronic shoulder pain. Important indications for MR imaging are any conditions or symptoms making assessment of the rotator cuff and the labrocapsular complex necessary. Assessment of the rotator cuff muscles, in particular, is crucial. The value of MR arthrography, which is still controversial, is discussed. The greatest potential benefit of MR arthrography is the accurate evaluation of subtle rotator cuff abnormalities and shoulder instability-related lesions, and the assessment of pathologic conditions of the long biceps tendon. This paper describes the most common pathologic findings of the shoulder joint and describes how the relevant findings are reported and quantified for the orthopaedic shoulder surgeon.

Visualization of Intraarticular Structures of the Acromioclavicular Joint in an Ex Vivo Model Using a Dedicated MRI Protocol

OBJECTIVE

The purpose of this study was to develop an MRI protocol that could visualize the intraarticular structures of the acromioclavicular (AC) joint.

MATERIALS AND METHODS

Using six fresh specimens from cadaveric shoulders, several MRI sequences were performed on 1.0-T scanners with a superficial coil (the temporomandibular joint coil). After the radiologic examination, the specimens were prepared for histology and 300-microm-thick, toluidine blue-stained sections were prepared that corresponded to the MR images. In each series of sections, immunohistochemistry using a type II collagen antibody was performed to further characterize the intraarticular structures.

RESULTS

The coronal 3D T1-weighted fast-field echo water-selective sequence allowed the identification of the intraarticular disk in all cases. Determination on MRI of other intraarticular structures--adipose tissue, synovial fluid, and the borders between neighboring tissues of different types--that corresponded to the histologic sections was possible. The use of a second plane in the 1.0-T sequences did not reveal additional information.

CONCLUSION

The described MRI protocol allows the visualization of the intraarticular fibrocartilaginous disk and the border between articular cartilage and the disk. Future clinical studies will indicate the diagnostic value of this protocol. We assume that this MRI protocol could help us to better understand AC joint disorders, in particular those located intraarticularly, and dislocations.

Osteoarthritis of the Acromioclavicular Joint

Shoulder pain is a frequent presenting complaint to physiatrists. Commonly encountered pathogeneses include rotator cuff pathology, bursitis, biceps tendonitis, and labral tears. Because the majority of shoulder pain originates within the subacromial region and the glenohumeral joint, the acromioclavicular, sternoclavicular, and scapulothoracic articulations may be overlooked. Osteoarthritis of the acromioclavicular joint is a common source of shoulder pain that is often neglected by clinicians and researchers. The proper diagnosis of acromioclavicular joint osteoarthritis requires a thorough physical exam, plain-film radiograph, and a diagnostic local anesthetic injection. Current treatment options are rather limited. Initial therapies are similar to that of osteoarthritis in other joints and include oral analgesics or anti-inflammatories and an emphasis on activity modification. Physical therapy, unfortunately, has little to offer, as therapeutic exercise and range of motion play only a minor role. If a diagnostic local anesthetic injection provides relief, there may be a role for corticosteroid injections. It seems that the administration of local corticosteroids into the acromioclavicular joint may provide short-term pain relief. The judicious administration of such injections remains controversial, and most experts agree that steroid injections do not alter the natural progression of the disease. Surgical options, indicated typically after a minimum of 6 mos of unsuccessful conservative treatment consist of open or arthroscopic distal clavicle resection.