Clinical Correlations Flashcards
Name the most commonly broken bone and where this occurs within the bone. Describe what the fracture may look like after and any pathology this may cause.
- broken clavicle between the medial 2/3 and lateral 1/3
- medial 2/3 may be elevated by the sternocleidomastoid muscle and the lateral 1/3 may be depressed by the body weight of the limb or adducted by the pectoralis major
- ventral rami of C8-T1 may be lacerated
Shoulder trauma may cause a _________ of the acromion at the acromioclavicular joint. Why doesn’t a complete dislocation occur?
- subluxation
- the coracoacromial ligament prevents dislocation at the AC joint
At the glenohumeral joint, the head of the humerus articulates with what?
-glenoid fossa of the scapula
For every ___ degree(s) of abduction of the humerus, there is ____ degree(s) of lateral rotation of the scapula.
- 3
- 1
- in full abduction, there is approximately 60 degrees of lateral rotation of the scapula
Tendons of the rotator cuff may become torn or inflamed. Which tendon of the SITS muscles is most commonly affected?
-Supraspinatus
Patients with rotator cuff tears experience what symptom(s)?
-pain anterior to the glenohumeral joint during abduction
In a dislocation of the humerus at the glenohumeral joint, the head of the humerus can usually be found where? What pathology may this cause?
- commonly displaced inferiorly and anteriorly and be comes positioned just inferior to the coracoid process
- may stretch the axillary or radial nerve
What issues may be caused from a fracture of the surgical neck of the humerus?
-axillary nerve may be lesioned and the posterior circumflex humeral artery may be lacerated
What issues may be caused from a fracture of the greater tubercle of the humerus?
- avulsion of the greater tubercle and deattachment of the rotator cuff muscles from the humerus
- the remaining rotator cuff muscle, the subscapularis, medially rotates the humerus at the glenohumeral joint
What issues may be caused by a transverse fracture of the humerus distal to the deltoid tuberosity?
-may result in abduction of the proximal fragment by the deltoid fragment
What issues may be caused in a midshaft (spiral) fracture of the humerus?
-the radial nerve may be lesioned and the profunda brachial artery may be lacerated
What issues may be caused by a supracondylar fracture of the humerus?
- contractions of the triceps and the brachialis may shorten the arm
- median nerve may be lesioned as a result of an intercondylar or supracondylar fracture at the distal end of the humerus
Lateral epicondylitis
- tennis elbow (LET pneumonic)
- an inflammation of the common extensor tendon that results from forced extension and flexion of the forearm at the elbow
- patients exhibit pain over the lateral epicondyle which may radiate down the posterior aspect of the forearm
Medial epicondylitis
- Golfer’s elbow
- an inflammation of the common flexor tendon that results from repetitive flexion and pronation of the forearm at the elbow
What issues may be caused by a fracture of the medial epicondyle?
-ulnar nerve may be lesioned
Colles’ Fracture
- fracture of the distal radius that may cause avulsion of the styloid process from the shaft of the radius
- radius may be shortened and the styloid process of the ulna may project further distally than the styloid process of the radius
- dinner fork deformity as a result of the posterior displacement of the distal part of the radius
What bone in the wrist is most commonly dislocated and what syndrome may it cause and why?
- lunate
- typically dislocated anteriorly into the carpal tunnel causing carpal tunnel syndrome
What/where is the Canal of Guyon and what traverses it?
- situated between the pisiform and the hook of hamate superficial to the carpal tunnel
- ulnar nerve, ulnar artery, and ulnar vein cross the wrist and pass into the hand after traversing it
Most commonly fractures bone in wrist and what issues may arise because of it.
- scaphoid
- pain over anatomic snuffbox
- proximal part of scaphoid may undergo avascular necrosis because the blood supply to the bone supplies the distal part first and then the proximal part
What anastomoses would occur if an occlusion of the first or second part of the axillary artery would occur?
- the circumflex scapular artery and thoracodorsal branches of the subscapular artery contribute to collateral circulation which may bypass blockage
- anastomoses may develop superior and posterior to the scapula between the thoracodorsal and circumflex scapular branches of the subscapular artery and the suprascapular, dorsal scapular, and posterior intercostal arteries.
What causes Volkmann’s ischemic contracture and what would a patient present with?
- may be caused by a supracondylar fracture of the humerus
- displacement of the humerus as a result of the fracture may compress the brachial artery and result in ischemia of the forearm and hand
- in these patients, the hand is severely flexed at the wrist and the fingers are severed flexed at the interphalangeal joints
Dupuytren’s contracture
- caused by fibrosis and shortening of the palmar aponeurosis
- thickening and shortening of the bands of the aponeurosis over the flexor tendons results in flexion of the ring and little fingers
Describe the gradient of innervation of the brachial plexus
-ventral rami of the brachial plexus exhibit a proximal to distal gradient of innervation
Muscles in the anterior arm, anterior forearm, and hand that act mainly as _______ are innervation by ___________. Muscles in the posterior arm and forearm that act mainly as _______ are innervated by _______________.
- flexors
- nerves that contain anterior division fibers
- extensors
- posterior division fibers
Preplexus injuries
-affect ventral rami or trunks of the brachial plexus proximal to the formation and branching of terminal and collateral nerves and have a more widespread effect than lesions to individual collateral or terminal nerves
What can cause suprascapular nerve lesions and what symptoms do patients present with?
- may be compressed as it courses through the scapular notch
- experience shoulder pain, weakness of abduction of the arm at the GH joint and lateral rotation at GH joint
Surgical procedures of the axilla may result in a lesion of the __________ nerve. Patients may have difficulty doing what?
- thoracodorsal nerve
- difficulty in elevating the trunk (climbing or pull-up) and difficulty in using a crutch
What nerve of the brachial plexus is most commonly lesioned and why? What do patients present with?
- long thoracic nerve because it courses superficial to the serratus anterior on the lateral wall of the thorax
- patients cannot hold the vertebral border of the scapula flat against the black and may have a “winging” of the vertebral bordeer of the scapula
- patients also have issues protracting scapula and raising their arm above their head
Lesions of musculocuteanous nerve
- uncommon, but can happen as it passes through the coracobrachialis muscle
- weakness in flexion of the forearm at the elbow and weakness in supination
What is compressed in carpal tunnel syndrome and where?
-median nerve as it courses through the carpal tunnel between the flexor tendons and the flexor retinaculum
Symptoms of carpal tunnel syndrome
- numbness and pain, particularly at night, over the palmar aspects of the thumb, index, and middle fingers
- ape hand due to weakness of thenar muscles (thumb cannot be opposed and is adducted and extended)
- lateral 2 lumbricals may be weakened, resulting in slight clawing of the index and middle fingers due to reduced ability to flex the MP joint and extend interphalangeal joints of these digits
Why may cutaneous sensation from the lateral aspect of the palmar be conserved in carpal tunnel syndrome?
-the palmar branch of the median nerve does not traverse the carpal tunnel
Where else may the median nerve be compressed and what additional symptoms may be in these patients?
- may be compresses proximal to cubital fossa in a supracondylar fracture or the humerus, or disal to cubital fossa as it passes between the 2 heads of the pronator teres
- in addition to altered sensation in the lateral part of the hand and a loss of thumb opposition, these patients experience weakness in pronation and weakness in ability to flex the thumb, PIP and DIP joints of index and middle fingers. and PIP joints of the ring and little fingers
- hand of benediction
Hand of Benediction
- proximal or distal median nerve lesions to cubital fossa
- index and middle fingers remain extended when the patient attemps to flex those digits to make a fist
Lesion of recurrent branch of the median nerve
- distal to carpal tunnel
- affects thenar muscles, resulting in ape hand with no cutaneous deficits
Anterior interosseus nerve lesions
- may be compressed near interosseus membrane deep in the anterior forearm
- result in weakness of pronation (pronator quadratus) and weakness in flexion at index and middle fingers at DIP joints
- weakness in ability to flex the distal phalanx of thumb (flexor pollicis longus) and an inability to form the letter o by touching the tip of the thumb to tip of index finger
Patients with an ulnar nerve lesion at the wrist may have a __________ which is caused by a _________.
- ulnar claw hand
- due to a weakness of the medial 2 lumbricals that flex at the MP joint and extend at the IP joints of ring and little finger
- weakness in abduct or adduct fingers or adduct thumb at MP joints (interosseus muscles and adductor pollicis) so they are unable to hold a piece of paper between the thumb and index finger or between adjacent finger
What occurs when ulnar nerve is lesioned at the elbow?
- as it courses adjacent to the medial epicondyle of the humerus, or compressed between 2 heads of the flexor carpi ulnaris
- in addition to ulnar claw and weakness in abduction and adduction of digits, patients may experience a weakness in the ability to flex the DIP joints of the ring and little fingers and a weakness in ability to flex the hand at the wrist
- pain and paresthesia in medial 1.5 digits
What can cause an axillary nerve lesion and what are the symptoms?
- result of dislocation of the head of the humerus from the glenoid fossa or by a fracture of the surgical neck of the humerus
- weakness in ability to abduct the arm at the GH joint because of loss of deltoid and altered sensation in skin covering the deltoid
- may be weakness in lateral rotation because of weakness of teres minor muscle
- deltoid may undergo atrophy resulting in a loss of the rounded contour of the shoulder
How is the radial nerve commonly lesioned and what do patients present with?
- spiral fracture of midshaft of the humerus
- wristdrop: weakness in ability to extend the hand at wrist and less of extension at MP joints of all digits
- supination may be weakened, but not lost bc biceps brachii is unaffected (musculocutaneous n)
- extension of forearm at elbow is spared because the triceps receives its innervation proximal to fracture
- pain and paresthesia in skin over first dorsal interosseus muscle
Distal to the elbow, which part of the radian nerve may be lesioned? how? symptoms?
- deep branch of radial nerve as it courses through the supinator by a subluxation of head of the radius
- wristdrop and weakness in ability to extend the MP joints but no serious sensory deficits
What part of the femur is a common site of fracture? Why is the worrisome?
- neck of the femur
- worry about avascular necrosis of the head of the femur due to disruption of the medial circumflex femoral artery
In patients with fractures of the femoral neck, the thigh is _________ by the short lateral rotators of the thigh at the hip and by the _______.
- laterally rotated
- gluteus maximus
A dislocation of the head of the femur at the hip joint occurs most commonly in the ______ direction. The thigh is ____________ due to what muscles? What nerve may be compressed and with what symptoms?
- posterior
- shortened and medially rotated by gluteus medius and minimus muscles
- sciatic nerve: weakness of muscles in posterior thigh, leg, and foot and paresthesia over posterior and lateral leg and dorsal and plantar surfaces of the foot
Terrible Triad of knee injuries
- tibial collateral ligament
- medial meniscus
- ACL
Patients with a medial meniscus tear have pain when ___________.
-the leg is medially rotated at the knee