Erkrankungen des Schultereckgelenks

Is conventional radiography still relevant for evaluating the acromioclavicular joint?

INTRODUCTION

Conventional radiography using an anteroposterior view of the acromioclavicular (AC) joint is the gold standard for evaluating arthritic degeneration.

OBJECTIVE

Based on a standardised AP view of the AC joint, the objective of this study was to determine whether this radiographic view is reliable and reproducible for evaluating the AC joint space.

METHODS

A cadaver scapula-clavicle unit, free of osteoarthritis, was used for this study. The scapula was positioned in a stand; and then with fluoroscopy guidance, a strict AP view of the AC joint was taken. Starting from this "0" position, a radiograph was taken by varying the angle by 5°, 10°, and 15° in every plane in space. All radiographs were taken during a single session to ensure the distance between the X-ray tube and scapula did not change. The images were then exported to OsiriX for processing; the superior and inferior AC distance and the joint area were measured.

RESULTS

There was no reproducibility in the AC joint measurements as a function of the incidence angle relative to a strict AP view.

CONCLUSION

Conventional radiography using an AP view of the AC joint cannot be used to do a fine analysis of arthritic degeneration of this joint. It is likely that only CT scan or MRI is sufficient to analyse osteoarthritis in this joint.

LEVEL OF EVIDENCE

IV, basic science study.

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.

The unstable os acromiale: a cause of pain in the young athlete

Purpose

Os acromiale is a common entity in the middle-age group, in whom it is frequently associated with rotator cuff tears. However, it can be a cause of shoulder pain in the young athletes. We want to increase awareness of this pathology that may occultly affect the young athlete as well as to present the results of a perfusion-preserving arthrodesis.

Methods

Four consecutive young patients (17-21 years old) with a history of at least 6 months of unrecognized shoulder pain were surgically treated for os acromiale. Through a superior approach, stabilization of the neo-joint by means of cannulated screws and autogenic graft augmentation was performed.

Results

Union of the os acromiale was achieved in all the patients. They had an excellent functional outcome, reaching all the maximum Simple Shoulder Test (12) and Oxford shoulder Score (48) scores. All the patients were able to return to their previous sports level.

Conclusion

Awareness of the os acromiale in the young athlete, appropriate clinical examination, and image studies are crucial to confirm diagnosis. Surgical treatment aiming at fusion in situ has shown excellent result.

Ultrasound-guided percutaneous treatment of a calcific acromioclavicular joint: A case report

RATIONALE

Calcific tendinopathy is one of the most frequent causes of nontraumatic shoulder pain. However, intra-articular calcifications appear to be an infrequent condition. We herein report a rare case study of an intra-articular calcification of the acromioclavicular joint.

PATIENT CONCERNS

A 46-year-old man presented with an acute pain in the anterior superior region of the left shoulder which also radiated to the left cervical region. The man during the physical evaluation also presented severe functional limitation of the shoulder movements in all planes of motion.

DIAGNOSES

The diagnosis was carried out through a radiographic and an echotomographic examination, highlighting the intra-articular calcific formation associated to a reactive inflammatory reaction.

INTERVENTIONS

An ultrasound-guided percutaneous treatment following the guidelines for calcific tendinopathy of the shoulder was carried out.

OUTCOMES

The posttreatment was satisfactory with the disappearance of the pain and the recovery of the shoulder movements in all planes of motion.

LESSONS

We can affirm that the ultrasound-guided percutaneous treatment in patients with calcification of the acromion-clavicular joint represents a valid and nonpainful therapeutic treatment.

Seven-year course of asymptomatic acromioclavicular osteoarthritis diagnosed by MRI

BACKGROUND

Asymptomatic acromioclavicular osteoarthritis (AC-OA) is a frequent finding in shoulder magnetic resonance imaging (MRI). Its natural course is unknown. Therefore, the question arises whether a resection should be performed simultaneously with shoulder surgery for another reason to prevent future pain and reoperation. The purpose of this study was to investigate the mid-term course of asymptomatic AC-OA.

METHODS

Overall, 114 asymptomatic AC-OA diagnosed on MRI were followed for 7 years between 2011 and 2018. At baseline, MRI signal enhancement in the clavicle and acromion, OA grade, physical demand as well as the parameters (1) Constant Score Visual Analogue Scale, (2) pain on AC-joint compression, and (3) cross-body adduction test were measured. All patients were followed up after 7 years by interview, and in case of symptoms by clinical examination. The endpoint "deterioration" was reached if 2 of the 3 parameters turned worse.

RESULTS

Asymptomatic AC-OA remained asymptomatic in 83% of cases, 7% turned better, 10% turned worse. Physical demand and osteoarthritis grade increased the risk of deterioration, whereas MRI signal enhancement in the clavicle or acromion had no influence on outcome. During follow-up, the frequency of pain on AC-joint compression increased from 11% to 16% (P = .24), the frequency of a positive cross-body adduction test increased from 6% to 20% (P = .017), and the mean Constant Score Visual Analogue Scale increased from 10 to 13 points (P < .001) indicating less pain.

CONCLUSIONS

Asymptomatic AC-OA remained asymptomatic in 90% over 7 years. A simultaneous resection of an asymptomatic AC-OA during shoulder surgery for another reason is not indicated in every patient.