Shoulder Conditions (Week 2 Module) Flashcards
Shoulder Conditions
Bones: humerus surgical neck fracture, humerus midshaft fracture–pathologic, clavicle fracture
Joints: shoulder instability and dislocation, acromioclavicular (AC) joint injuries, adhesive capsulitis
Muscles/tendons: shoulder impingement syndrome
Nerves/vessels (peripheral neuropathies): thoracic outlet syndrome, brachial plexopathy, suprascapular nerve entrapment, radial nerve entrapment–upper arm
Humerus surgical neck fracture
Most common proximal humerus fracture, often caused by falling onto outstretched hand or direct impact to shoulder
Most commonly injured nerve is axillary nerve, which results in sensory changes over deltoid and weakness with abduction of shoulder joint
EMG and NCS used to diagnose associated nerve damage
Humerus midshaft fracture–pathologic
Bone weakened by pathologic lesion (neoplasm, osteomyelitis, Paget’s disease) so trivial pressure on humerus can cause this
Can cause injury to radial nerve, resulting in loss of sensation over dorsum of hand and weakness with wrist extension
EMG and NCS to diagnose associated nerve damage
Clavicle fracture
Most common childhood fracture because clavicle doesn’t completely ossify until late teens
80% occur in middle third of clavicle, medial to coracoclavicular ligament; proximal fragment usually displaced upward because of pull of SCM
Usual mechanism of injury is direct force applied to lateral aspect of shoulder (fall onto outstretched hands or injury from automobile accident)
Shoulder instability and dislocation
Background: Less than 1/3 of head of humerus is in contact with glenoid cavity, so stability of shoulder joint depends on increased depth of glenoid cavity provided by labrum, joint capsule, capsular ligaments, and rotator cuff muscle tendons
Pathophysiology: ligament laxity (developmental, repeated injury, age-related degeneration); anterior dislocations most common (95%; lax inferior glenohumeral ligament) and often due to direct force or repeated activity that induces abduction and external rotation of shoulder joint; posterior dislocations as result of posterior transitory force on flexed shoulder joint; after one dislocation occurred, shoulder may dislocate again without provocation
Clinical presentation: chronically diffuse muscle pain around the shoulder with no obvious trauma; but will see obvious asymmetry and deformity; can be asymptomatic, muscle spasm (deep diffuse aching pain), dislocation (sharp severe pain increases w/movement at joint), locally tender muscles and positive Sulcus Sign, limited ROM passive/active
Management/prognosis: NSAIDs, opioids, joint reduction, strength training; good prognosis unless labrum tears (repeated dislocations)
Acromioclavicular (AC) joint injuries
Pathophysiology: fall or blow to top of shoulder and acromion driven into ground; AC joint sprain (Grade I) is injury to AC joint ligaments but coracoclavicular ligaments not injured and no separation of clavicle from acromion; AC joint separation (Grade II) when coracoacromial ligaments injured is partial separation of clavicle from acromion or (Grade III) complete separation of clavicle from acromion
Clinical presentation: Grade I sprain: swelling, tenderness, some loss of shoulder movement (adduction) due to pain, normal or asymmetrical on visual comparison of shoulders; Grade II or III separation: severe pain with shoulder movements, bump or high-riding tip of the clavicle, scapula inferiorly displaced; BOTH: pain to palpation; see distance in AC joint space on plain film X ray
Management/prognosis: NSAIDs, opioids, rest/sling and joint function should return within 6-8 weeks w/residual bony callus for Grade I sprain; surgery then extensive rehab for Grade II or III separation
Adhesive capsulitis
Pathophysiology: “Frozen shoulder” is chronic immobility of shoulder joint resulting in scarring, thickening, inflammation of joint capsule, progressive loss of range of motion, some had no pre-existing shoulder condition but have limited movement from stroke, muscle weakness, brain injury etc and others have pre-existing shoulder condition/previous surgery, usually affects 40-70yo, more in females
Clinical presentation: deep, dull, aching stiffness and pain, gradual onset, increased pain w/movement, difficulty sleeping on affected side, decreased ROM (esp external rotation), diffuse tenderness; MRI may show scarring of glenohumeral joint capsule but not needed to make diagnosis
Management/prognosis: NSAIDs, PT, ultrasound, glenohumeral joint injection; good prognosis
Shoulder impingement syndrome
Pathophysiology: AKA “rotator cuff tendonitis, supraspinatus tendonitis, subacromial bursitis, calcific bursitis, tendonitis” result of degenerative process exacerbated by overuse or previous injury, decreased blood flow to rotator cuff tendons (spuraspinatus) causes microtears and inflammation, get granulation tissue and Ca2+ crystals collecting beneath subacromial bursa, tear entire rotator cuff and get huge inflammation (rotator cuff tear causes unopposed pull of deltoid muscle which can damage articular cartilage of glenohumeral joint and cause OA)
Clinical presentation: gradual onset anterior/lateral shoulder pain worse reaching overhead, difficulty sleeping/night pain, atrophy of supraspinatus muscle, pain with abduction, pain in aduction and flexion over 90 degrees and internal rotation with arm abducted or flexed, no passive limitation of motion, tender over point of shoulder and laterally near subacromial bursa, positive Hawkin’s sign and Neer’s sign, do MRI to confirm, on X-ray may see joing space narrowing and subchondral bone sclerosis
Management/prognosis: NSAIDs, opioids, ice, heat/ultrasound, subacromial bursa injection, surgery to remove part of acromion to prevent compression of supraspinatus tendon; resolve with conservative tx but may progress to rotator cuff tear
Thoracic Outlet Syndrome
Compression of lower trunk of brachial plexus and/or subclavian vessels as they course between clavicle and 1st rib, due to cervical rib, long C7 transverse process, posttraumatic fibrosis of scalene muscles
Women between 20-50 commonly affected
Pain and paresthesias along ulnar aspect of forearm, hand, medial 2 fingers (brachial plexus compression); intermittent swelling and discoloration of arm worse when arm over head (vascular compression)
Exercises to promote muscle strengthening and proper posture
Brachial Plexopathy
Traction injury to shoulder area that damages part of brachial plexus (trunks, divisions, cords, nerves)
Weakness and sensory loss
Most common site is upper trunk (traction force on C5-6 nerve roots when shoulder depressed and head and neck tilted opposite side) and causes arm hanging uselessly bc paralysis of shoulder girdle and biceps and loss of extension at wrist (“waiter’s tip deformity”), and shoulder held at internally rotated position (bc supra and infraspinatus which externally rotate, are paralyzed)= Erb’s Palsy in children
Transient injuries to upper trunk of brachial plexus involving C5-6 nerve roots (athletes in contact sports) = burners/stingers
Less often lower trunk (traction force to C8-T1 nerve roots when arm abducted) which has poor prognosis and damage to intrinsic muscles of hand (lumbricals and interossei) causes finger flexors to be unopposed (“claw hand”) = Klumpke’s Palsy
Suprascapular Nerve Entrapment
Strong, tight suprascapular ligament closes over free upper margin of suprascapular notch and suprascapular nerve, which courses deep to suprascapular ligament, can be entrapped if pressure placed on ligament (carrying heavy purse or backpack that presses against upper scapula)
The only sensory fibers in suprascapular nerve are to posterior aspect of shoulder joint, so get dull shoulder pain there, maybe shoulder movement weakness (esp with abduction); no neck pain
Radial Nerve Entrapment–Upper Arm
Radial nerve can be compressed at various sites along its course in the upper arm: axilla (using crutches) causes elbow extension (triceps) weakness and sensory abnormalities in posterior arm and forearm; radial groove deep to triceps brachii muscle (“Saturday night palsy” because when you hang arm over back of chair when sleeping)
Compression of radial nerve can causes sensory changes on radial side of forearm, radial side of wrist, dorsum of lateral 3 1/2 fingers (not tips), and motor deficit so can’t extend wrist, thumb, fingers so hand droops (“wrist drop”)
