Acromioclavicular Arthritis

Original Editor - Manisha Shrestha Top Contributors - Manisha Shrestha, Lucinda hampton, Kim Jackson and Jacob Bischoff

Introduction[edit | edit source]

Left AC joint degenerative changes.

Osteoarthritis of the acromioclavicular (AC) joint is a common condition which causes anterior or superior shoulder pain, particularly evident with overhead and cross-body activities. It is common in middle-aged individuals due to degeneration to the fibrocartilaginous disc that cushions the articulation. Diagnosis depends on history, physical examination, imaging, and diagnostic local anesthetic injection[1].

Most of the patients are asymptomatic, and they may present as an incidental finding in shoulder X-Ray or MRI. [2]

Clinically Relevant Anatomy[edit | edit source]

Acromioclavicular joint

The acromioclavicular (AC) joint is a synovial joint with a limited range of motion, and it is the only articular connection between the axial skeleton and the scapula. The distal clavicle has a convex surface that articulates with the slight convex surface of the acromial facet. The hyaline cartilage covered facets have a fibrocartilage disk between them, in some ways similar to the meniscus of the knee. Degenerative changes are a natural process, and in early adulthood, the fibrocartilage disk is degenerated, with only fibrous remnants left.[3]

Epidemiology[edit | edit source]

AC osteoarthritis is much less common than degenerative pathology at other locations (eg knee, hip), however it is considerably more common than glenohumeral osteoarthritis, with a study finding that 54–57% of elderly patients had X-ray evidence of degenerative changes of the AC joint (however clinically relevant AC osteoarthritis is not so common)[3]. AC joint osteoarthritis accounts for ~20% (range 12.7-24%) of patients with shoulder pain. It most commonly presents in the fourth decade.[4]

Etiology[edit | edit source]

Type of AC joint arthritis-Based on the etiology

  1. Primary osteoarthritis is articular degeneration without any apparent underlying cause. It develops as a consequence of constant stress on the joints, often in people who perform repeated overhead lifting activities.
  2. Secondary osteoarthritis: It is due to other associated causes like post-trauma or other underlying diseases such as rheumatoid arthritis. Post-traumatic AC joint arthritis is even more prevalent due to the high incidence of injury to the joint. Arthritic symptoms have been demonstrated in Grade I and II sprains of the AC joint in 8% and 42% of patients, respectively.[5]

Diagnosis[edit | edit source]

Accurate diagnosis of pathology to the AC joint is essential in determining the treatment in order to avoid persistent shoulder pain. The diagnosis of ACJ arthritis requires a thorough history taking, physical exam, plain-film radiograph, and a diagnostic local anesthetic injection.[6]

X-ray and MRI give the most complete imaging picture of AC and pathology. However US can easily detect signs of AC osteoarthritis and is a common imaging mode used. US guidance injections are nowadays an extremely helpful tool for performing a diagnostic test easily and effectively.[3]

Subjective Assessmment[edit | edit source]

Subjective assessment may find:

  • History of trauma eg direct impact on the joint or a fall on an outstretched arm.
  • Occupational history, such as an occupation that requires repeated overhead lifting activities
  • Participation in sports that stress/injure AC joint eg weightlifting, rugby. [2]
  • Complaints of pain at night during sleeping on the affected shoulder.
  • Patient may experience popping, clicking, grinding, or catching sensation with the movement of their shoulder.[7].
  • Functional limitations of ACJ pain include difficulty with resistance-training activities that place the glenohumeral joint in an extended position, common in weightlifters so ACJ arthritis is also known as Weightlifter's Shoulder.[8]
  • Damage to the ACJ can be synchronous with damage to the supraspinatus tendon and osteophytes from the arthritic AC joint may contribute to subacromial impingement exacerbating and producing further shoulder pain.[2]

Objective Assessment[edit | edit source]

The cross-over adduction test is performed by the motion of forward flexion to 90° with horizontal adduction of the arm across the chest. Reproducible pain over the joint suggests AC joint involvement.

Patients often present with an intact range of motion with the exception of cross-body adduction, behind the back motions, and overhead reaching, which all produce pain localized to the AC joint.[5]

  • Localized superior shoulder pain,[8]
  • AC joint may be tender to palpation. Possibly swelling in the AC joint due to distal clavicle osteolysis.
  • Pain elicited to the deltoid area by the motion of forward flexion to 90° with horizontal adduction (cross-over test) or straight-ahead pushing (as in the bench press exercise).[5]

Acromioclavicular joint involvement can be confirmed by an injection of a local anesthetic. Injection of 0.5–2 mL of 1% or 2% lidocaine or 0.5 mL of 0.25 or 0.5% bupivacaine into the AC joint should provide a significant reduction in symptoms. A continuation of pain following anesthetic injection suggests other shoulder pathologies, most commonly rotator cuff injury.[5]

Differential Diagnosis[edit | edit source]

Management[edit | edit source]

The management of ACJ pain appears to be determined by the degree of pain and disability.

Non- Surgical/ conservative[edit | edit source]

Non-operative management is usually considered first, with activity modification, physical therapy modalities, oral analgesics (NSAIDs), and injections of corticosteroid and local anesthetic all being options.

Local corticosteroid injection[edit | edit source]

Injections of 0.25–0.5 mL of betamethasone sodium phosphate and acetate or 0.25–0.5 mL methylprednisolone, 40 mg/mL are recommended. Limits of two to four injections per year with a total of twenty are recommended, as excessive corticosteroid administration may cause subcutaneous fat atrophy and dermal thinning. It is suggested that injections can provide good pain relief and be a helpful diagnostic test, but seem to be ineffective as a long term therapy.

Activity modification[edit | edit source]

It includes avoidance of repetitive motions causing the pain, such as push-ups, dips, flies, and bench press exercises.[5] Repetitive overhead activities, related sports need to be avoided until the health professionals recommend.

Physiotherapy treatment[edit | edit source]

Physiotherapy intervention should be individualized based on the grade of osteoarthritis, level of pain, and functional limitations.

Impairment based treatment:

[9]

Evidence

A prospective single-cohort study conducted by Harris et al. in 2012 regarding the effect of manual therapy in non-acute AC arthritis pain.

  • It showed a statistically significant and clinically meaningful improvement in both functional and clinical outcome measures at 4 weeks and 6 months following manual therapy.
  • The treatment duration was a 30-minute clinical sessions twice a week for 3 weeks.
  • The primary treatment techniques were passive accessory glides of the distal end of the clavicle with the upper extremity in various physiological positions selected to make the ACJ treatment technique less painful. At other times, positions were selected to be more consistent with a position of pain during activity.
  • After the 4-week follow-up visit, patients received instructions for a home-exercise program that consisted of strengthening and range-of-motion exercises.
  • Statistically significant and clinically meaningful improvements were observed in all outcome measures at 4 weeks and 6 months, following a short series of manual therapy interventions. [8]

Surgical[edit | edit source]

Surgical treatment is only recommended if conservative treatment fails to provide adequate pain relief and persistent symptoms continue to interfere with activities of daily living after 6 months of intensive non-surgical treatment.

Distal clavicle excision (DCE)

  • It is an operative approach also known as the “Mumford” procedure and is commonly performed.
  • It was initially performed as an open procedure, first described in 1941 but now is performed arthroscopically.
  • The procedure aims to produce a ‘gap’ between acromion and clavicle and involves resecting bone mainly from the distal end of the clavicle without compromising joint stability.[2]
  • Open surgical complications for these procedures occur in 0% to 64% of cases and include infection, heterotopic ossification, joint instability, suprascapular neuropathy, and distal clavicle fracture, in addition to complications associated with anesthesia.[8] Other complications include weakness of the deltoid and trapezius muscles and clavicular instability.[5]
  • Eskola et al investigated long-term results of patients managed with DCE for complaints of ACJ pain and reported that nearly 1 in 3 patients had poor long-term outcomes and advised against DCE for patients with higher functional demands on their shoulders.[8]

[10]

Future directions[edit | edit source]

A scoping review published in 2017

  • reveals a lack of primary evidence regarding treatments and treatment pathways for ACJ pain. At no point have arthroscopic surgery, open surgery, steroid injections, and rehabilitation programs been compared directly.
  • also shows making it difficult to delineate the cause of shoulder pain and the effectiveness of subsequent treatments as some bias was introduced by the fact that many patients with ACJ pathologies also had other concomitant shoulder pathologies, such as rotator cuff tears.[2]

Thus, proper assessment is necessary for the patient with shoulder pain followed by a holistic approach to treatment including lifestyle modification, education, medication, physiotherapy, and if necessary surgery followed by proper rehabilitation.

Related pages[edit | edit source]

References[edit | edit source]

  1. Mall NA, Foley E, Chalmers PN, Cole BJ, Romeo AA, Bach Jr BR. Degenerative joint disease of the acromioclavicular joint: a review. The American journal of sports medicine. 2013 Nov;41(11):2684-92.Available:https://pubmed.ncbi.nlm.nih.gov/23649008/ (accessed 23.6.2022)
  2. 2.0 2.1 2.2 2.3 2.4 2.5 Chaudhury S, Bavan L, Rupani N, Mouyis K, Kulkarni R, Rangan A, Rees J. Managing acromio-clavicular joint pain: a scoping review. Shoulder & Elbow. 2018 Jan;10(1):4-14.
  3. 3.0 3.1 3.2 Precerutti M, Formica M, Bonardi M, Peroni C, Calciati F. Acromioclavicular osteoarthritis and shoulder pain: a review of the role of ultrasonography. Journal of Ultrasound. 2020 Sep;23(3):317-25.Available: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7441096/(accessed 23.6.2022)
  4. Radiopedia AC joint OA Available: https://radiopaedia.org/articles/acromioclavicular-joint-osteoarthritis (accessed 23.6.2022)
  5. 5.0 5.1 5.2 5.3 5.4 5.5 5.6 Docimo S, Kornitsky D, Futterman B, Elkowitz DE. Surgical treatment for acromioclavicular joint osteoarthritis: patient selection, surgical options, complications, and outcome. Current Reviews in Musculoskeletal Medicine. 2008 Jun 1;1(2):154-60.
  6. Buttaci CJ, Stitik TP, Yonclas PP, Foye PM. Osteoarthritis of the acromioclavicular joint: a review of anatomy, biomechanics, diagnosis, and treatment. American journal of physical medicine & rehabilitation. 2004 Oct 1;83(10):791-7.
  7. Vaishya R, Damor V, Agarwal AK, Vijay V. Acromioclavicular arthritis: A review. Journal of arthroscopy and joint surgery. 2018 May 1;5(2):133-8.
  8. 8.0 8.1 8.2 8.3 8.4 Harris KD, Deyle GD, Gill NW, Howes RR. Manual physical therapy for injection-confirmed nonacute acromioclavicular joint pain. journal of orthopaedic & sports physical therapy. 2012 Feb;42(2):66-80.
  9. AC Joint Pain Exercises for Shoulder Rehab. Available from: https://www.youtube.com/watch?v=m581lMvKSvw. [Lasted accessed: 2021/2/5]
  10. Mysportsdoc. Arthroscopic Distal Clavicle Excision. Available from: https://www.youtube.com/watch?v=OyvRDNJPC9Q. [Lasted Accessed: 2021/2/5]