Shoulder and Upper Limb Nerve Entrapment Flashcards
What is shoulder impingement syndrome?
AKA painful arc syndrome A syndrome (not a diagnosis) where the rotator cuff muscle tendons become inflamed as they pass through the subacromial space
Results in painful arc, weakness and loss of movement (struggle actively but passive movement is often normal); night pain is unusual
Signs of shoulder impingement syndrome?
Painful arc
Hawkins sign
Other impingement tests
Muscle wasting is unusual
Describe Hawkins sign
Patient should sit in a relaxed sitting position; arm is moved passively by the examiner; the examiner moves the arm, such that it is in 90 degrees of forward flexion and the elbow is flexed to 90 degrees
Examiner forcefully moves the patient’s shoulder into internal rotation to the end point; if pain is felt, this is a +ve test
Differential diagnoses with shoulder impingement syndrome?
Frozen shoulder (AKA adhesive capsulitis)
Rotator cuff tear
Shoulder instability
Describe the painful arc sign
Pain on abduction between 70-120 degrees; with a true painful arc, the pain disappears at the top of the arc (over 120 degrees) and there is no pain below 70 degrees
This is variable
Describe crescendo arc sign
Pain does not disappear at the top of the arc; often caused by OA of the shoulder joint, with osteophytes impinging on the tendons
Potential causes of shoulder impingement syndrome?
- Osteophytes from OA
- Shoulder instability - displaced humeral head can impinge the nerve
- Bursal causes, e.g: bursitis can place pressure on the tendons
- Labral injury
- Biceps tendinopathy
- Scapular dysfunction
- Calcific tendinitis - deposits calcium phosphate in any tendon of the body, typically the rotator cuff tendons, causes a presentation similar to that of gout; a differential is septic arthritis and, if uncertain, a joint aspirate can be done before injecting steroids into the subacromial space
- Os acromiale - failure of fusion of the acromial process; the unfused fragment can cause impingement
Bigliani acromial grading system?
Shape of the acromion:
• Type I - flat (most space, so least likely to suffer impingement)
• Type II - curved
• Type III - hooked (least space, so most likely to suffer from impingement)
Limitations of shoulder joint arthritis treatment?
Not as successful at THR/TKR
Reverse arthroplasty, when it works, is a good treatment but there is a high risk of complications
Types of shoulder instability?
- Traumatic (Bankart/Hill Sachs lesions)
* Atraumatic
Describe traumatic shoulder instability
T - traumatic
U - unilateral (usually)
B - Bankart lesions (tends to cause these)
S - surgery (Bankart repair/latarjet) is a treatment
Types of shoulder dislocation?
Anterior dislocation (most common)
Posterior dislocation
What is a Bankart lesion?
Lesion of the anterior inferior labrum, caused by repeated anterior shoulder subluxations/dislocations
This is the cause of recurrent dislocation and may be treated with surgery
What is a Hill Sachs lesion?
Cortical depression in the posterolateral head of the humerus, resultings from forceful impaction of the humeral head against the anteroinferior glenoid rim, when the shoulder is dislocated anteriorl
Describe atraumatic shoulder instability
A - atraumatic M- multidirectional B - bilateral R - rehabilitation I - inferior capsular shift
Describe MDSI (multi-directional shoulder instability)
Caused by abnormal soft tissues, e.g: due to Ehlers-Danlos syndrome (connective tissue disorder)
Often triggered by minor trauma that allows voluntary control of instability
Treated using inferior capsular shift by reducing capsular volume
Signs of MDSI?
Sulcus sign
Assessment of MDSI?
Beightons score (quantifies joint laxity and hypermobility in 9 points, with a threshold for joint laxity in young adults being 4-6 points)
Appearance of a posterior shoulder dislocation on X-ray?
Humeral head appears more spherical than it should; if unsure, request an X-ray in 2 directions
What is carpal tunnel syndrome?
Paraesthesiae in the median nerve distribution, i.e: tingling in the thumb, index, middle and 1/2 of the ring finger, due to compression in the carpal tunnel
Night-time disturbance with tingling is common
Treatment of carpal tunnel syndrome?
Conservative treatment with night splints works for the majority
Surgery can be used; injections are used sometimes but there are issues with ensuring the nerve is not injected
Ix for carpal tunnel syndrome?
Gold standard - nerve conduction studies
What is cubital tunnel syndrome?
Paraesthesia in the ulnar nerve distribution (half of the ring finger and all of the pinky finger); caused by compression of the ulnar nerve, commonly behind the medial epicondyle of the elbow
Treatment of cubital tunnel syndrome?
Surgical release
Anterior dislocation
