I. Rotator Cuff Tears
A. Epidemiology/overview
1. The prevalence of full-thickness rotator cuff tears is 7% to 40% (cadaveric studies).
2. Partial-thickness rotator cuff tears are more frequent (50% higher incidence).
3. The incidence of progression from partial-thickness rotator cuff tears to full-thickness tears is 28% to 53%.
4. The incidence and prevalence of rotator cuff tears increases with age.
5. Up to 51% of patients older than age 80 years have asymptomatic rotator cuff tears.
B. Pathoanatomy
1. Intrinsic—Changes in collagen, proteoglycan, and water content associated with aging and/or degeneration
2. Extrinsic—Mechanical etiology from coracoacromial (CA) arch
C. Evaluation
1. History
a. Older patients (age >60 to 65 years) often have no history of trauma.
b. Some patients aged 50 to 60 years may have no history of trauma, but this presentation is less frequent.
c. Younger patients (age <40 years) often have a history of high-energy injury.
d. Pain
i. Night pain typical
ii. Overhead activities
iii. Reaching behind back
2. Physical examination
a. Inspection—Atrophy in the infraspinatus fossa indicates a chronic tear.
b. Palpation—Greater tuberosity, acromioclavicular (AC) joint, bicipital groove, coracoid process
c. Range of motion—Active and passive
d. Provocative tests
i. Neer, Hawkins impingement signs (
Figure 1)
ii. Modified lift-off test—To assess subscapularis function (
Figure 2)
iii. Abdominal compression test—Also assesses subscapularis function.
e. Strength testing
i. Resisted elevation test—To assess supraspinatus function
ii. External rotation test—To assess infraspinatus/teres minor function
iii. Lag signs—A positive external rotation lag sign indicates a massive tear, including an infraspinatus tear. A positive Hornblower sign indicates teres minor dysfunction.
iv. Subscapularis tear—Abdominal compression test, lift-off test
3. Imaging
a. Radiographs
i. True AP view (check acromiohumeral interval; normal = 7 to 14 mm) (
Figure 3)
ii. AP view in external and internal rotation
iii. Supraspinatus outlet view (acromial morphology)
iv. Axillary view (glenohumeral joint morphology, joint space) (
Figure 4)
b. MRI
i. The gold standard
ii. T2-weighted images are best for viewing rotator cuff tears (
Figure 5).
[Figure 1. Provocative tests for rotator cuff tears. A, Neer impingement sign. With the patient seated, the examiner depresses the patient's scapula while the patient's arm is elevated. This test compresses the greater tuberosity against the anterior acromion and elicits discomfort in a patient with a rotator cuff tear or impingement syndrome. B, Hawkins impingement sign. This test reinforces a positive Neer impingement sign. The patient's shoulder is elevated to 90° with the elbow flexed to 90° and the forearm in neutral rotation. The arm is supported and the humerus is then rotated internally. Pain elicited with this test is indicative of a rotator cuff tear or impingement syndrome.]
[Figure 2. The modified lift-off test for subscapularis function. In this test, the patient places a hand behind the back with the palm facing away from the body and then lifts the hand away from the back. A patient with a subscapularis tear will not be able to lift the hand off the back.]
iii. MRI reveals muscle/tendon retraction and muscle atrophy, factors that can be used to determine chronicity.
iv. Intra-articular contrast-enhanced magnetic resonance arthrography is used for partial-thickness rotator cuff tears.
[Figure 3. True AP radiograph of shoulder, to evaluate glenohumeral joint space. DC = distal clavicle, A = acromion, C = coracoid, H = humerus, G = glenoid.]
c. Ultrasonography
i. The advantages of ultrasonography are that it is highly accurate and it allows for dynamic assessment of cuff insertion.
[Figure 4. Radiograph of shoulder, axillary view. C = coracoid, H = humerus, G = glenoid, A = acromion.]
ii. The disadvantages of ultrasonography are that it is operator dependent and its use makes it difficult to assess the pathologic condition of the glenohumeral joint.
d. CT arthrogram is not commonly used in the United States.
D. Classification
1. Acute—A history of injury or an inciting event occurring less than 3 months prior to presentation in a previously asymptomatic shoulder.
2. Chronic—Symptoms occurring longer than 3 months from the time of injury.
3. Acute on chronic—Enlargement of a smaller tear.
4. Rotator cuff tears are often classified by size.
5. They are also classified as full-thickness or partial-thickness tears.
6. Partial-thickness rotator cuff tears are most commonly classified by location (articular- or bursal-sided) and size (greater or less than 50% thickness).
E. Treatment
1. Nonsurgical
a. Avoid provocative motions.
b. Apply ice.
c. Administer nonsteroidal anti-inflammatory drugs (NSAIDs)
d. Physical therapy
i. Rotator cuff and periscapular stabilizer strengthening
ii. Terminal stretching exercises—Avoid extension, internal rotation.
[Figure 5. T2-weighted coronal oblique MRI scan demonstrates a supraspinatus tear (arrow).]
e. Corticosteroid subacromial injection
i. Risks—Tendon atrophy, infection, decreased tendon quality for repair
ii. Benefits—Diminished night pain, improved motion
f. Older patients may do well with nonsurgical treatment.
2. Surgical
a. Indications
i. Full-thickness and partial-thickness rotator cuff tears that fail nonsurgical treatment
ii. All acute, traumatic tears in young patients (age <60 years)
iii. Acute loss of strength or motion at any age
iv. Good quality muscle on MRI, with absence of fatty infiltration
v. No significant arthritis
b. Contraindications
i. Chronic infection
ii. Glenohumeral arthritis
iii. Chronically retracted tendons and atrophic rotator cuff muscles
iv. Fixed proximal migration, acromiohumeral interval <7 mm
v. Deltoid, axillary nerve dysfunction
3. Surgical procedures
a. Arthroscopic—Establish appropriate arthroscopic portals.
i. The posterior portal is 1 cm medial and 1 cm inferior to the posterolateral corner of the acromion.
ii. The rotator interval portal is just lateral to the coracoid process; it is used for intraarticular work.
iii. The anterolateral portal is 2 cm lateral/inferior to the lateral acromion; it is used to access the subacromial space.
iv. Posterolateral subacromial portals
b. Mini-open (lateral portal extension approach)
i. Deltoid-splitting (without deltoid takedown) open cuff repair
ii. Appropriate for small to medium tears, superior third of the subscapularis
c. Open rotator cuff repair
i. Deltoid detachment from the acromion—Subsequent repair is important.
ii. Avoid splitting the deltoid >3 to 5 cm from the anterolateral corner of the acromion, to protect the patient from axillary nerve injury.
iii. Open rotator cuff repair is appropriate for all sizes of tears.
iv. Massive rotator cuff repairs
(a) Assess reparability with preoperative MRI. Evidence of end-stage cuff fatty atrophy might preclude repair.
(b) Maintain the integrity of the CA ligament to prevent iatrogenic anterosuperior escape.
v. Currently no evidence exists that allograft augmentation (allograft, xenograft, dermal grafts, etc) improves functional outcomes.
vi. Partial-thickness, articular-sided rotator cuff tears
(a) If >50%, complete and repair (open or arthroscopic).
(b) If <50%, debride tuberosity and undersurface rotator cuff.
(c) Repair tendon in situ (ie, partial articular supraspinatus tendon avulsion [PASTA] repair) when remaining attached tissue is healthy.
d. Tendon transfers
i. Irreparable posterior cuff tears—Transfer latissimus dorsi and/or teres major to the greater tuberosity. An intact subscapularis tendon is required for latissimus dorsi tendon transfer.
ii. Consider for the younger adult patient (eg, a laborer) who has difficulty elevating the affected shoulder and is too young and active for arthroplasty options.
iii. Irreparable subscapularis tear—Transfer the pectoralis major to the lesser tuberosity or the anteromedial greater tuberosity.
F. Complications
1. Infection
a. The incidence of infection as a complication of surgery is <1% overall.
b. Propionibacterium acnes is the most common infecting organism. Other organisms include coagulase-negative Staphylococcus, Peptostreptococcus, and S aureus.
2. Deltoid dehiscence after arthroscopic and/or open rotator cuff repair
3. Recurrent tears are more common with larger tears and in older patients (age >65 years).
4. Iatrogenic suprascapular nerve injury
5. Missed pathologic conditions
a. Biceps tendinitis
b. AC arthritis/synovitis
c. Instability
d. Capsulitis/stiffness
G. Pearls and pitfalls
1. Appropriate nonsurgical treatment—Avoid multiple corticosteroid injections.
2. Open surgical procedures that involve deltoid detachment require meticulous deltoid repair.
3. Deltoid dehiscence is a devastating complication of open rotator cuff repair.
4. Specific complications associated with arthroscopy include severe edema, peripheral nerve neurapraxia, and failure of rotator cuff repair.
II. Rotator Cuff Arthropathy
A. Epidemiology/overview
1. Causes of symptomatic shoulder arthritis in the setting of rotator cuff dysfunction
a. Localized rheumatoid arthritis
[
Figure 6. Nutritional and mechanical pathways to cuff tear arthropathy (CTA). (A) Nutritional factors include the loss of a so-called watertight joint space and a reduction in the pressure of the joint fluid that is required for the perfusion of nutrients to the articular cartilage, both of which contribute to atrophy of cartilage and disuse osteoporosis in the subchondral bone of the humeral head. (B) Mechanical factors include upward, anterior, and posterior instability of the humeral head. Upward instability escalates wear into the anterior part of the acromion, the AC joint, and the coracoid.]
b. Rapidly destructive shoulder arthritis
c. Hemorrhagic shoulder of the elderly
d. Milwaukee shoulder (crystalline-induced arthropathy)
e. Cuff tear arthropathy (CTA)
2. Usually affects the dominant shoulder
3. Average age of patient—69 years
4. Female-to-male ratio—3:1
B. Pathogenesis
1. The pathogenesis of CTA is unknown.
2. Neer described mechanical and nutritional pathways to CTA (Figure 6).
3. Crystalline-induced arthropathy
a. Synovial-based matrix degradation proteins destroy rotator cuff tendons and cartilage.
b. Calcium phosphate crystal deposition is found in end-stage disease.
4. Characteristics of CTA
a. Massive chronic rotator cuff tear
b. Destruction of glenohumeral cartilage
c. Osteoporosis of subchondral bone
d. Humeral head collapse
C. Evaluation
1. Physical examination
a. Inspect for muscle (supraspinatus, infraspinatus) atrophy, anterior prominence of humeral head from "anterosuperior escape" with arm elevation, and subcutaneous effusion.
b. Range of motion
i. Subacromial/glenohumeral crepitus
ii. End-stage CTA will have "pseudoparalysis," ie, no glenohumeral elevation.
c. Strength testing for rotator cuff weakness
i. A positive external rotation lag sign indicates a massive tear, including an infraspinatus tear.
ii. A positive Hornblower sign indicates teres minor dysfunction.
2. Imaging
a. Radiographic features
i. Acetabularization of the acromion (AP views)
ii. Femoralization of the humeral head (AP views)
iii. Eccentric superior glenoid wear (AP views)
iv. Lack of typical peripheral osteophytes of osteoarthritis
v. Osteopenia
vi. Subarticular sclerosis (snowcap sign)
vii. Loss of CA arch indicates anterosuperior escape.
b. MRI
i. Establishes the extent of rotator cuff disease
ii. Not routinely necessary
D. Classification—Rotator cuff tear arthropathy has been classified by Seebauer (
Table 1).
E. Treatment
1. Nonsurgical
a. Activity modification
b. Physical therapy
c. Corticosteroid subacromial injection
d. Modalities (ice, ultrasound) may be of some benefit for pain relief.
2. Surgical
a. Indications
i. Failed nonsurgical treatment
ii. A pseudoparalytic, painful shoulder
iii. A functioning deltoid is necessary.
iv. Patient compliance with postoperative treatment
b. Contraindications
i. Deltoid dysfunction
ii. Chronic infection
iii. Poor glenohumeral bone stock
3. Surgical procedures
|
a. |
Arthroscopic debridement i. Unpredictable results ii. Must maintain CA arch; avoid acromioplasty or CA ligament release iii. Greater tuberosity "tuberoplasty"—Creates smooth tuberosity-acromion interface |
|
b. |
Hemiarthroplasty (humeral head replacement) i. Restore anatomic humeral head size ii. Medialize component under CA arch with concentric glenoid reaming iii. Must maintain deltoid and CA arch/ligament iv. Limited goals for rehabilitation (pain relief) |
|
c. |
Reverse shoulder arthroplasty (RSA) ( Figure 7) i. Indications—A pseudoparalytic CTA shoulder or elderly (age >70 years) patients (controversial); patients with anterosuperior escape. ii. Prerequisites—A functioning deltoid and adequate glenoid bone stock. iii. The center of rotation is moved inferiorly and medially to assist deltoid fulcrum. iv. Outcomes—Early results are promising for improved elevation, but RSA may not improve external or internal rotation. |
[Table 1. Seebauer Classifcation of Cuff Tear Arthropathy]
|
v. |
RSA may be combined with latissimus dorsi transfer to assist with external rotation. |
|
|
d. |
Resection arthroplasty—Indicated in salvage situations only, for patients with a history of osteomyelitis, chronic infections, multiple previous operations, or poor soft-tissue envelope. |
|
|
e. |
Total shoulder arthroplasty—Contraindicated in shoulders with severe rotator cuff deficiency or the rocking horse glenoid phenomenon. |
|
|
f. |
Arthrodesis—Indicated in salvage situations only; in general, it is poorly tolerated by older patients (age >60 years). |
|
F. Complications
1. Prosthetic replacement
a. Infection
b. Anterosuperior escape after hemiarthroplasty
c. Prosthetic instability
2. RSA—High complication rate
a. Infection
[Figure 7. AP radiograph of a shoulder after reverse shoulder arthroplasty.]
b. Instability
c. Component wear
d. Inferior scapular notching
G. Pearls and pitfalls
1. Maximize nonsurgical treatment with therapy, NSAIDs.
2. Anterosuperior escape is an iatrogenic complication secondary to loss of the CA arch after aggressive acromioplasty in conjunction with rotator cuff insufficiency. To avoid anterosuperior escape, the CA arch should be preserved with arthroscopic debridement and arthroplasty.
3. Avoid glenoid implantation, which leads to early glenoid failure (total shoulder arthroplasty).
III. AC Joint Arthrosis
A. Epidemiology/overview
1. Degenerative disease of AC joint
2. More common with age
3. Commonly seen in individuals who engage in constant repetitive heavy overhead work (eg, construction, weightlifting)
4. Chronic AC joint separations can lead to post-traumatic AC joint arthrosis.
5. Arthritic changes in the AC joint seen on radiographs do not always correlate with the patient's symptoms.
B. Pathoanatomy (
Figure 8)
1. The AC joint is a diarthrodial joint, the only articulation between the scapula and the clavicular strut.
2. The fibrocartilaginous disk (contained within the joint) degenerates with age.
3. Stability is provided by the capsular AC ligaments (which contribute to horizontal stability) and the coracoclavicular ligaments (the conoid and the trapezoid), which provide vertical stability.
4. Osteophytes form at the distal clavicle.
C. Evaluation
1. History
a. Activity-related pain—Pain with overhead movement, adduction
b. Weightlifting can lead to osteolysis of the distal clavicle.
2. Physical examination
[Figure 8. Drawing showing normal anatomy of the AC joint.]
a. Point tenderness on palpation of the AC joint
b. Mild edema at the AC joint
c. Positive horizontal cross-body adduction test (sensitive, not specific)
d. Check for AC joint instability.
e. Selective local injections of lidocaine into the AC joint can help confirm pathologic findings and the diagnosis.
3. Imaging
a. Radiography
i. Standard AP view of the shoulder (one third less penetration for AC joint)
ii. Zanca view (15° cephalic tilt directed at AC joint)
b. MRI—Joint edema correlates with AC joint symptoms.
D. Treatment
1. Nonsurgical
a. Rest, ice, NSAIDs, activity modification
b. Corticosteroid AC joint injection
2. Surgical
a. Indications
i. Symptomatic AC joint arthritis
ii. Failed course of nonsurgical management
b. Contraindications—Significant AC joint instability (Distal clavicle resection [DCR] alone is unsuccessful in treating AC instability and can often exacerbate the problem.)
3. Surgical procedures
a. Arthroscopic DCR
b. Open DCR (Mumford procedure)
i. Resect 0.5 to 1 cm (enough to prevent horizontal contact).
ii. To avoid iatrogenic injury and subsequent vertical instability, do not violate the coracoclavicular ligaments.
iii. Disruption of the AC joint ligament can lead to horizontal instability.
iv. Meticulous repair of the deltoid-trapezial fascia is required.
E. Complications
1. Excessive DCR (>1 to 1.5 cm)
a. Removal of the AC ligaments leads to anteroposterior instability.
b. The posterior and superior AC ligaments are the most important for stability.
c. Excessive DCR medially (violating the coracoclavicular ligaments) leads to superior-inferior instability.
2. Inadequate DCR leads to continued AC joint impingement pain.
3. Heterotopic ossification
4. Deltoid dehiscence (open procedure)
F. Pearls and pitfalls
1. Consider transosseous deltoid-trapezial fascia repair during open DCR.
2. During arthroscopic or open DCR, maintain the superior and posterior AC joint capsular ligaments (to prevent instability).
Top Testing Facts
Rotator Cuff Tears
1. Older patients might do well with nonsurgical treatment.
2. To determine if a rotator cuff tear is chronic, use MRI to measure muscle retraction and atrophy.
3. Open surgical procedures that involve deltoid detachment require meticulous deltoid repair.
4. During repair of massive rotator cuff tears, maintain integrity of the CA ligament to prevent iatrogenic anterosuperior escape.
5. An intact subscapularis tendon is required for latissimus dorsi tendon transfer.
Rotator Cuff Arthropathy
1. Characteristics of CTA include a massive, chronic rotator cuff tear; destruction of glenohumeral cartilage; osteoporosis of subchondral bone; and humeral head collapse.
2. Acetabularization of the acromion and femoralization of the humeral head are two radiographic features of rotator cuff arthropathy.
3. RSA is indicated if the patient has a pseudoparalytic, CTA shoulder or is older than age 70 years (controversial).
4. Total shoulder arthroplasty is contraindicated in the treatment of rotator cuff arthropathy because it may lead to glenoid failure (the "rocking horse" phenomenon).
5. To avoid anterosuperior escape, the CA arch should be preserved with arthroscopic debridement and arthroplasty.
6. Anterosuperior escape is salvageable with RSA.
AC Joint Arthrosis
1. Arthritic changes in the AC joint seen on radiographs do not always correlate with the patient's symptoms.
2. DCR alone is unsuccessful in treating AC instability and can often exacerbate the problem.
3. During arthroscopic or open DCR, maintain the superior and posterior AC joint capsular ligaments (to prevent instability).
4. When performing open DCR, resect 0.5 to 1 cm of distal clavicle (enough to prevent horizontal contact); excessive resection (>1 to 1.5 cm) can lead to joint instability.
5. Excessive DCR medially (violating the coracoclavicular ligaments) leads to superior-inferior instability.
6. During open DCR, meticulous repair of the deltoidtrapezial fascia is required.
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