Shoulder Pathology Overview

• The presentation covers shoulder pathology, rotator cuff disorders, glenohumeral instability, adhesive capsulitis, fractures, and acromioclavicular joint pathology.

Objectives

• Recognize common shoulder pathologies and impairments.
• Discuss the etiology, risk factors, and biomechanical influences contributing to shoulder pathologies.
• Discuss current diagnostic and medical management of common shoulder pathologies.
• Explain the various forces acting on the upper quadrant and how posture and ergonomics attenuate them.
• Recognize clinical features that assist in identifying different shoulder pathologies.

Conditions to Consider

• Subacromial pain syndrome, glenohumeral instability, adhesive capsulitis, fractures, and acromioclavicular (AC) joint dysfunction are conditions to consider.

Subacromial Pain Syndrome

• Subacromial pain syndrome includes impingement, tendonitis, bursitis, tendinopathy, and tears.

Rotator Cuff Disorders

• Rotator cuff disorders involve issues often occurring in the subacromial space.
• Diagnoses to consider are impingement, subacromial bursitis, RTC issues (posterior), RTC tendinopathy (itis, osis), biceps tendinopathy, and RTC tears (partial to full thickness).
• Similar precautions and prognosis are considered.
• Common key positive findings include a painful arc of motion, pain reproduced with tests that tension or compress subacromial tissues, pain with isometric resistance, weakness, and atrophy.
• Common key negative signs include a significant loss of motion and GH instability.
• Impingement-type syndromes account for 40-60% of all shoulder pain
• Mechanical impingement involves structures in the subacromial space with the anterior undersurface of the acromion.
• RTC tendinopathy and hypertrophy of the AC joint could be considered diagnoses.
• Degenerative and/or mechanical compression can occur.
• Mechanical compression ("extrinsic") and tension overload and degeneration ("intrinsic") are characteristics of RTC tendinopathy.
• Acromion shape plays a role in RTC tendinopathy.
• Normal CA ligaments and thickening of CA ligaments are involved.
• Neer described stages of impingement (tendinopathy) in 1983.
• Stage 1 is edema and hemorrhage, often in younger athletic individuals, which is reversible.
• Stage 2 is tendinitis and fibrosis, typically in the 25-40 age range.
• Stage 3 involves bony changes and tearing, common in older individuals (>40 y).
• Subacromial impingement and RTC tears can be a cause or an effect.
• Subacromial impingement may result from tendon dysfunction, with articular side tears more common than bursal side tears.
• RTC tendinopathy considers the pec muscle length.
• Thoracic manipulation improves shoulder function, kinematics, or thoracic mobility.
• Tight posterior capsules can lead to anterior humeral head translation, with increased pressure on the CA arch = leading to degenerative changes over time.
• Rotator cuff (RTC) muscle performance (weakness or tear) has an impact on impingement-type symptoms.
• Leads to increased pressure of the cuff on the CA arch = degenerative damage over time
• Rotator cuff tears can be pathogenic or include contributing factors.
• Tears are classified by size and severity.
• Tendons form a continuous veil of connective tissue, interdigitate, and collaborate to centralize and compress the HH in the glenoid.
• Impingement, acromion morphology, and RTC tears are structural considerations in RTC tendinopathy.
• True weakness vs motor control is a muscle performance element to consider.
• Rounded shoulder posture and lumbar/thoracic spine issues are addressed.
• Subacromial impingement, GH instability, trauma, and congenital abnormalities can cause RTC "disease."
• Atraumatic tendon tears are rare under 40 years, with partial thickness typically beginning between 40-60 years.
• US studies of 588 patients showed no tears at 48.7 years, UL tears at 58.7 years, and B/L tears at 67.8 years, with a 50% likelihood of B/L > 66 years.
• Rathbun & Macnab described vascular insufficiency in 1970.
• Areas of hypo-vascularity occur in the watershed region and in the insertion at the greater tuberosity.
• A discrepancy between the bursal side rich vascularity and the articular side tenuous vascularity leads to increased incidence of partial tears on the articular side.
• An ultrasound is a standard of care outside of the U.S.
• MRI is the standard of care in the U.S., but has issues like over-utilization and cost.
• A 2003 study by Dinnes found no difference in sensitivity or specificitybetween MRI and Ultrasound.
• MRI, when used as a reference point, found Supraspinatus tendon accuracy around 91.1%, Infraspinatus tendon accuracy around 84.4%, Subscapularis tendon accuracy around 77.8%, and Long head of biceps tendon accuracy around 86.7%.
• In a normal rotator cuff, the tendon is dark and continuous to the greater tuberosity.
• A full-thickness tear appears white and incomplete on an MRI.
• Cofield classification system is generally used.
• A small tear is ≤ 1 cm, medium tear is 1-3 cm; large tear is 3-5 cm; massive tear ≥ 5 cm.
• Proximal attachment of LHB is supraglenoid tubercle.
• Role is not that of a prime mover.
• The diagnosis is often seen as an additional finding during imaging for RTC pathology.
• Diagnoses can be either acute (traumatic) or chronic (degenerative).

Glenohumeral Instability

• Shoulder stability is a coordination of static (bony congruence, cartilage, joint capsule, ligaments) and dynamic (musculature) stabilizers.
• Laxity, subluxation, partial dislocation, and dislocation are spectrums of instability.
• Abnormal symptomatic translation of HH relative to the glenoid can require reduction to restore alignment.
• Younger age, history of dislocation/subluxation, positive apprehension/relocation tests, and generalized laxity are key positive signs.
• Lack of dislocation/subluxation history and apprehension with testing are key negative signs.
• Classification of GH Instability
  • Frequency: Single episode, occasional (2-5), frequent (>5)
  • Etiology: Traumatic (macrotrauma), atraumatic, congenital, neuromuscular
  • Direction: Unidirectional, multidirectional
  • Severity: Dislocation, subluxation
• FEDS classification yields 36 combinations, but 6 categories are most meaningful:
  • Solitary/occasional/frequent traumatic anterior dislocation (STAD/OTAD/FTAD)
  • Solitary/occasional/frequent traumatic anterior subluxation (STAS/OTAS/FTAS)
• Mode of injury:
  • Traumatic: TUBS (traumatic unidirectional Bankart lesion surgery)
  • Atraumatic: AMBRI (atraumatic multidirectional bilateral rehabilitation, inferior capsule shift)
• Treatment options: Conservative vs Surgical.
  • Surgical outcomes are better in patients.
  • Rehabilitation is preferred over operative management in patients with atraumatic instability.
• With traumatic instability:
  • High-velocity uncontrolled end-range force must be considered.
  • Anterior instances are from forced abd/ER or elevation.
  • Posterior instances are from forced horiz add/IR with axial load.
  • Inferior instances are from forceful inferior load with the arm at the side and in elevation.
  • 85-95% are anterior, and 84-100% result in Bankart lesions.

Labral Damage

• Occurrences are often referred to in clock terms like "4:00-6:00."
• Results in 50% reduction in depth of the socket.
• Increased recurrences can lead to worse pathology.
• Occurs with time between injury and if surgery is delayed longer.
• Bony Bankart lesion = avulsion fx of glenoid.
• Hill Sachs lesion:
  • Cortical depression on the posterior humeral head.
  • Forceful impaction of the humeral head against the anterior-inferior glenoid rim with an anterior dislocation.
  • Occurrence with 100% recurrent instability, 80% with primary anterior instability, and 25% with anterior shoulder subluxation.
• Nerves:
  • Nerve damage can occur.
  • Axillary nerve palsy can result from prolonged dislocation and traction.
• Improving dynamic stability and control are a goal.
  • Work on RTC and scapular stability.
  • Progress work into functional positions.
  • Consider deltoids, biceps, triceps.

SLAP Lesions

• Superior Labrum Anterior to Posterior (from a 10:00 to 2:00 POV)
• Up to seven types, however, commonly separated into four main types.
• Type I includes fraying of the superior labrum while remaining attached to the glenoid rim.
• Type II includes separation of the superior portion of the glenoid labrum and tendon of the biceps brachii muscle.
• Type III includes bucket-handle tears of the superior portion of the labrum w/out biceps brachii involvement.
• Type IV bucket-handle tears of the superior portion of the labrum extending into the biceps tendon.

Adhesive Capsulitis

• Characterized by progressive pain and limited active/passive ROM with a characteristic presentation and recovery.
• Insidious onset of progressive pain, progressive loss of motion in multiple planes (especially ER, particularly at 0° abduction), and being female are key positives.
• Capsular pattern is present.
• Risk factors include diabetes, thyroid disease, previous episodes in the contralateral arm, or recent surgery/injury.
• The primary form is idiopathic, while the secondary form has known disorders (systemic, extrinsic, intrinsic).
• Reactive phase involves pain control, the "frozen" phase involves joint mobility, and "thawing" phase involves a return to function.
• A hallmark sign is limited lateral (external) rotation with the arm at the side.
• Intra-articular (but not subacromial) injection is a treatment.
• Consider MUA if this fails.

Fractures

• Codman's classification is widely accepted for fractures.
• Fractures are classified as two-part, three-part, and four-part based on the number of fracture segments.
• Two-part surgical neck fractures are common (60-80% of PHF's), typically addressed with percutaneous or deltopectoral approaches.
• Three-part fractures include SN + displaced GT and are surgically addressed using a deltopectoral approach with interfragmentary sutures/wires and supplemental Ender's rods or blade-plates.
• Four-part fractures are medically debilitating and commonly addressed with surgical procedures, such as Hemiarthroplasty with a reverse total shoulder arthroplasty. Fracture dislocation can occur and must be addressed.
• Denervation can occur in 96 patients (67%) of Visser et al.’s( 2001) study.
• Can result in injury to the axillary, suprascapular, radial, or musculocutaneous nerves.

AC Joint Pathology

• Injuries typically occur from direct trauma/blow to the lateral shoulder (e.g., a fall), especially while the arm is adducted.
• The acromioclavicular (AC) ligament provides stability in the A-P plane.
• Coricoclavicular (CC) ligaments provide the majority of vertical stability and assist passive scapular motion during elevation.
• AC joint separations are classified into six types.
• Rockwood’s classification considers sprains (no tear), AC capsule/ligament ruptures, and complete ruptures with increased CC distance.
• Visual step-offs can occur due to acromion depression.
• Complete rupture of AC and CC ligaments is common, with dislocations varying in severity.
• Clinical examination, active/passive compression tests, horizontal adduction assessment, AP views, IR/ER assessment, and Scapular Y/Axillary views are used for diagnosis.
• Types I and II are typically treated non-operatively. Type III is similar in treatment; however, surgery may be performed if substantial instability is present. Types IV, V, and VI are typically operative.