Elbow Anatomy, Biomechanics, and Pathology PDF

The Elbow Anatomy, Biomechanics, and Pathology  The elbow joint is a complex joint due to the number of articulations that work together to perform its motions: • Humero-ulnar joint. • Humero-radial joint. • Proximal radio-ulnar joint. • Distal radio-ulnar joint.  While the interactions are comp...

The Elbow Anatomy, Biomechanics, and Pathology  The elbow joint is a complex joint due to the number of articulations that work together to perform its motions: • Humero-ulnar joint. • Humero-radial joint. • Proximal radio-ulnar joint. • Distal radio-ulnar joint.  While the interactions are complex, the humero-ulnar and humero-radial joints can be viewed together as a uni- axial joint providing the main flexion/extension of the elbow joint with the following range of motion:  flexion: - approximately 145° (actively) approximately 160° (passively)  extension: - approximately 0-15°  Elbow flexion is limited or checked by a muscular end-field from either the triceps muscle or from the biceps if there is a large muscle belly. Elbow extension is limited by a bony end-field. The olecranon abuts against the olecranon fossa to prevent hyperextension. It is common for flexible females to exhibit hyperextension of the elbow up to 20°.  The resting position for the elbow is 90° flexion with the forearm in neutral supination and pronation.  The position of reference is the upper arm and forearm in the frontal plane with the elbow straight and the forearm supinated.  The close-packed position is full extension. The Humero-ulnar Joint  The humero-ulnar joint is the medial joint system between the humerus,(the trochlea) and the ulna (the olecranon). Its classification is a diarthrodial, synovial, hinge (uniaxial) joint. The elbow is a compound joint that is considered to have one degree of freedom for flexion and extension. The trochlea is situated between the two epicondyles of the distal end of the humerus.  The trochlea’s transverse surface is concave and its antero- posterior surface is convex, which melds a convex surface with a concave one to make one complex curved surface shaped like a saddle. Therefore, the humero-ulnar joint is a saddle joint.  The transverse axis of the humerus does not lie at a right angles to its longitudinal axis. The transverse axis lies in a slightly oblique and medially directed line  The ulna tends to have a deviation laterally from the longitudinal axis of the humerus that forms an acute angle of between 7°and 12°. This is known as the carrying angle and occurs with elbow extension. Humero-Ulnar Joint  The carrying angle of the elbow will usually be caused by a few common factors.  The transverse axis through the trochlea tilts medially and obliquely causing the medial surface to lie distal to the lateral surface.  The articular groove between the medial and lateral surfaces of the trochlea circumscribes a spiral. From an anterior view, the groove is directed laterally. As this groove circumscribes the spiral on the trochlea, it faces medially on its posterior surface. The olecranon glides medially on this spiral groove during extension to create the carrying angle and direct the forearm laterally. During flexion the olecranon follows the trochlear groove laterally thereby directing the forearm medially.  This actually creates a medial gapping with lateral gliding and a lateral gapping with medial glide during flexion and extension  Flexion-extension of the elbow is accompanied by a screw- home mechanism with conjunct rotation of the ulna. With the elbow fully flexed, the olecranon is directed laterally. As the elbow is extended, the olecranon circumscribes the trochlear groove to direct itself medially. By following the trochlear groove, the ulna externally rotates (or supinates) during elbow flexion and internally rotates (or pronates) during elbow extension. Whether or not the carrying angle changes in flexion and extension is controversial. It has been described as both decreasing in angle with flexion and not changing at all. If change does indeed occur, it is related to the angulation of the trochlea  The conjunct rotation during flexion and extension at the elbow can be observed of the every time you bring food to your mouth. In order to feed yourself, your forearm must lie medial to the axis of the upper arm. This is achieved by a combination of internal rotation of the glenohumeral-humeral joint and flexion of the elbow with slight supination or external rotation of the forearm. ELBOW JOINT  The forearm is also influenced by the carrying angle. As you completely extend your elbow, the medial structures move apart while the lateral structures become compressed, creating the elbow deformity known as cubitus valgus commonly seen in tennis players, pitchers, and javelin throwers. The radius becomes close-packed against the capitellum during full extension, which causes a tendency for it to glide distally.  Excessive valgus overload during the acceleration phase of pitching. This valgus overload wedges the olecranon into the olecranon fossa. The follow-through phase of a throw can cause impingement farther posteriorly and increase symptoms by adding stress to this area. This valgus stress occurs before full extension of the elbow.  Osteochondritis can also be a secondary pathology with repetitive microtrauma in the throwing athlete . The repetitive compression forces associated with elbow extension in the throwing maneuver may result in cartilage damage and formation of loose bodies. Osteochondrosis and osteochondritis dissecans may be more prevalent in the immature skeleton and are often associated with the “Little League elbow syndrome HUMERAL-RADIAL JOINT  The humero-radial joint forms the lateral relationship between the humerus (capitulum) and the head of the radius. It is a diarthrodial, synovial, hinge joint by classification. The hemispherical capitulum articulates with a concave, oval facet on the proximal head of the radius .  The medial rim of the head of the radius fits into a groove between the trochlea and capitulum . During both flexion-extension and pronation-supination, this capitulo-trochlear groove guides movement and increases the stability of the head of the radius.  The humero-radial joint is a modified saddle joint. The capitulum has no cartilage on its extreme posterior surface. And the articular cartilage of the radius has no contact with the posterior part of the capitulum at full extension.  The radial cartilage is commonly irritated by bony contact with the posterior aspect of capitulum during traumatic hyperextension injuries. An initial stage of cartilage degeneration accompanied by pain and dysfunction can occur as a result of this trauma. This injury is frequently misinterpreted as a lateral epicondylitis. HUMERAL-RADIAL JOINT  As the capitulum assumes a close-packed position against the radius during extreme extension, it creates a lateral compression at the humero-radial joint. If the hyperextension is preceded by a “running start” such as occurs during a tennis player’s backhand swing, the capitulum makes even greater bony contact against the radial cartilage which further increases the chances for injury including micro-trauma to the cartilage, bleeding, swelling, and resultant muscle guarding.  During flexion, the coronoid process of the ulna glides into the coronoid fossa, which is devoid of articular cartilage. If one has small biceps, irritation of the interarticular tissues can occur with pain and dysfunction  The articular cartilage of the head of the radius extends distally around the head to articulate with the annular ligament. The motion that occurs within this joint is a uniaxial spin. Rotation between these structures produces pronation and supination of the forearm.  The radial head is a tapered disk, more oval than round. This oval head of the radius is also tapered like a section of a cone. LIGAMENTS of the Elbow Ligaments of the Elbow  The medial collateral ligament reinforces the humero-ulnar articulation. This triangular shaped ligament extends from the medial epicondyle of the humerus and attaches to the coronoid and olecranon process of the ulna. The medial collateral ligament is a thickening of the joint capsule.  Two distinct ligamentous bundles correspond to the anterior and posterior portions of the ulnar collateral ligament. The posterior bundle consists of collagen bundles within the layers of the capsule; the anterior bundle consists of a similar thickening within the capsular layers, but has an additional ligament complex superficial to the capsular layers  The medial collateral ligament (MCL) resists any valgus load to the joint. The ligament has three bands: the anterior oblique, posterior oblique, and transverse portions. The anterior oblique band originates from the inferior surface of the medial epicondyle. It lies just posterior to the flexion/extension axis, which causes its anterior portion to be taut in extension and the posterior position to be taut in flexion. The anterior band is the primary ligamentous support for the medial elbow. LIGAMENTS  The transverse band originates from the medial olecranon and inserts on the coronoid process of the ulna. This is primarily a thickening of the joint capsule that has only minor contribution to elbow stability.  The posterior oblique band originates from the medial epicondyle and inserts into the posteromedial olecranon. The band is taut in flexion, primarily after 60°.  The fan-shaped radial collateral ligament, also called the lateral collateral ligament, reinforces the humero-radial joint. It runs from the lateral epicondyle of the humerus and attaches to the annular ligament and olecranon process.  The annular ligament is a strong fibrous-osseous ring lined with articular cartilage that surrounds the circumference of the head of the radius. The ligament covers four- fifths of the circumference of the radial head and is funnel shaped tapering distally. Its external surface blends with the joint capsule and radial collateral ligament. The annular ligament is attached to the anterior and posterior edges of the radial notch. Humeral-Radial Joint and Ligaments  When the elbow is semi-flexed, the radio-humeral joint lacks bony stabilization and is vulnerable to injury. The strong biceps tendon inserts into the radial tuberosity and provides a cranial force and can stress on the annular ligament. This lack of bony stabilization frequently results in an elbow dislocation where the radius loses its relationship with the capitulum, the radial notch of the ulna, and the capitulo-trochlear groove.  Since the radius lacks bony stability in flexion, it can only rely on the annular ligament to hold it in place. If one pronates the forearm, not only is a fulcrum created between the radius and ulna, but also the biceps tendon is lengthened to create a greater pull. By lifting the heavy suitcase in this position, an annular ligament rupture can occur due to the cranial pull of the biceps tendon Interosseous Membranes MUSCLES of the FOREARM  Pronator teres O: Humeralhead—Immediately above the medial epicondyle of the humerus, common flexor tendon Ulnar head—Medial side coronoid process of ulna I: Middle of lateral surface of radius A: Pronate forearm and assist in flexion elbow N: Median nerve,C6-C7  Pronator quadratus O: Medial side, anterior surface of distal quarter of ulna I: Lateral side, anterior surface distal quarter radius A: Pronates forearm\ N: Median nerve,C8-T1  Supinator O: Lateral epicondyle of humerus, radial collateral ligament, annular ligament, and supinator crest of ulna I: Lateral surface, upper third of anterior and posterior body of radius A: Supinates forearm N: Radial nerve,C5-C6  Biceps brachii  O: Short head—Apex of coracoid process Long head—Supraglenoid tubercle of scapula  I: Tuberosity of radius A: Flexes and supinates elbow and flexes shoulder with  some abduction if humerus is externally rotated  N: Musculocutaneousnerve,C5-C6  Triceps brachii  O: Long head—Infraglenoid tubercle of scapula Lateral head—lateral and posterior surfaces, proximal half  body of humerus, above radial groove Medial head—distal two thirds medial and posterior  surfaces of humerus, below radial groove I: Posterior surface of olecranon process of ulna A: Extends elbow, and ADD and extends shoulder (long head) N: Radialnerve,C6-C8  Anconeus  O: Posterior surface lateral epicondyle of humerus I: Lateral side olecranon process and upper quarter  posterior surface of ulna  A: Extends elbow  N: Radialnerve,C7-C8 ARTERIAL SUPPLY to the ARM NERVES of the FOREARM Median Nerve Nerves of the Elbow and Forearm  Median Nerve  Segmental levels C5-T1 Cords: medial and lateral  Travels down medial aspect of arm with brachial artery and ulnar nerve.  Forearm: About 5 to 8 centimeters below the lateral epicondyle it gives off the anterior interosseous branch innervating muscles anterior to the membrane. The median nerve proper passes between the superficial and deep flexors innervating the flexor digitorum superficialis and palmaris longus.  Approximately 5.5 centimeters above the radial styloid, the palmar cutaneous branch innervates the skin of the proximal palm over the first, second, and third metacarpals. The median nerve passes through the carpal tunnel and gives off a motor branch to the thenar muscles, and a terminal motor branch to the two radial lumbricals and palmar digital nerves to the volar surface of I, II, III, and radial half of IV, and the dorsal surface of their middle and distal phalanges. Median Nerve Pathology  Pathology:  1. Common sites of injury: a. Fracture of humerus and distal radius b. Dislocations of the elbow and anterior dislocation of the lunate. c. Lacerations of the anterior wrist. d. Compression sites:  Ligament of Struthers Pronator teres (pronator syndrome) Anterior interosseous syndrome Carpal tunnel  2. SYMPTOMS: A. Distal injury: Deficits involve precision movements of the thumb and index, loss of thumb tip to fingertip prehension, loss of pulp to pulp prehension, and loss of protective and discriminatory sensibility in I, II, III, and the radial half of IV. Presentation will be an “ape hand” appearance.  B. Proximal to elbow: there is an additional loss of wrist flexion secondary to flexor carpi radialis.  C. Injury of the anterior interossei nerve results in loss of flexion of the distal thumb and index finger. Median Nerve and Muscles of the forearm Normal carpal tunnel and Guyon’s canal. Axial proton density MR image at level of proximal carpal tunnel shows flexor retinaculum (straight black arrow) extending between pisiform (P) and scaphoid (S) and enclosing median nerve (round-tailed arrow)and low-signal-intensity flexor digitorum and flexor pollicis longus tendons. Guyon canal is visualized at this level with ulnar nerve (straight white arrow) between pisiform and ulnar artery (dashed arrow) and its paired veins. Flexor carpi ulnaris tendon (curved black arrow) and flexor carpi radialis tendon (curved white arrow) are visualized. Axial proton density MR image at level of distal carpal tunnel shows flexor retinaculum (straight black arrow) extending between hook of hamate (H) and trapezium (Tm). Median nerve is mildly flattened (round-tailed arrow). Ulnar nerve (straight white arrow) lies adjacent to tip of hook of hamate, with adjacent ulnar artery (dashed arrow) and veins. Flexor carpi radialis tendon (curved arrow) is visualized. Ulnar Nerve Pathology Segmental level: C7 to T1 Cords: Medial Pathways:  Arm: Travels medial to median nerve and brachial artery approximately halfway down and descending posteriorly.  Elbow: Crosses the elbow posteriorly between the medial epicondyle and olecranon.  Forearm: In upper forearm it passes through and innervates the two heads of the flexor carpi ulnaris and flexor digitorum profundus of the fourth and fifth fingers. It continues on a straight course down the forearm.  Wrist: The nerve becomes superficial and travels with the ulnar artery. Proximal to the pisiform it gives off a palmar cutaneous branch, which innervates the ulnar proximal palm. It also gives off a dorsal cutaneous branch, which innervates the ulnar half of the dorsum of the hand and half of the fourth and all of the fifth digits.  The ulnar nerve proper passes through Guyon’s Tunnel giving off superficial terminal cutaneous branches to V and half of IV digit, and a deep motor branch to hypothenar muscles, interossei muscles, and lumbricals IV and V, adductor pollicis and the deep head of the flexor pollicis brevis. 29-year-old man with Guyon canal syndrome. Axial proton density image shows multilobulated ganglion cyst (white arrows) within Guyon canal compressing ulnar nerve (black arrow) against pisiform. Ulnar Nerve ULNAR NERVE PATHOLGY Common sites of injury: A. Fractures to the medial epicondyle and olecranon, or osteophyte formations. B. Cubital tunnel entrapment is the second most common form of entrapment neuropathy of the upper limb. The nerve passes through a fibrous tunnel where it may become entrapped. During elbow flexion the nerve will elongate proximally but not distally to the tunnel. The length of the cubital tunnel retinaculum will also increase by an average of 45 percent from full elbow extension to full flexion. Other etiologies of cubital tunnel syndrome include osteoarthritis of the elbow joint, isolated cubitus valgus deformity, isolated cubitus varus deformity, rheumatoid arthritis and trauma to the cubital tunnel.  The nerve itself will also enlarge in this region adding to the compression through this tunnel. Enlargement can start 15-19 millimeters proximal to the distal humerus extending distally for 10-12 millimeters. Other compression sites at the elbow include a “snapping” separate medial head of triceps, a prominent medial head of triceps covering the ulnar nerve, anconeus epitrochlear, and the ligament of Struthers have been implicated.  Ulnar neuropathies may occur in conjunction with medial epicondylitis. Other than positive tests for tendonitis of the common flexor tendon, the most provocative test for the nerve in this case is resisted pronation of the forearm with resisted flexion of the wrist being slightly less sensitive.  C. Compression sites: Cubital Tunnel of Guyon. ULNAR NERVE  Mechanism for ulnar nerve entrapment at the elbow.  Elbow flexion decreases available space for ulnar nerve in cubital tunnel. Causes compression by aponeurosis that bridges the two heads of flexor carpi ulnaris muscle.  Posterior interosseous nerve (one of main branches of the musculospiral) Passes through substance of supinator brevis.  Liable to become pinched by unusual action of the muscular fibers.  Passes through the two heads of the supinator, in the arcade of Froshe, a fibrous arch occurring in 30 percent of the population. ULNAR/MEDIAN NERVE SENSORY DISTRIBUTION ULNAR NERVE PATHOLGY *Symptoms include pain and paresthesia in the ulnar distribution of the hand. Atrophy of the hypothenar may be present. *Distal lesion results in an inability to perform thumb lateral pinch against resistance secondary to loss of adductor pollicis. *Lack of interossei function and lumbrical function of IV and V results in decreased grip strength, inability to fully extend the fingers (IV and V) for picking up objects resulting in a ‘claw hand’, inability to fully flex the fingers into cylindrical or spherical grip limiting grip function to a hook-like grasp, and loss of protective and discriminatory sensibility in ulnar half of hand. * The “claw hand” deformity is caused by weakness of the  Lumbricals, interossei, and flexor digitorum profundus muscles with unopposed action of the finger extensors (radial nerve) and flexor digitorum superficialis (median nerve) all leading to hyperextension of the 4th and 5th digits at the MCP joints with flexion of the interphalangeal joints.  Proximal lesion: additional loss of grip secondary to loss of profundus to IV and V and decreased flexor power secondary to flexor carpi ulnaris. Ulnar Nerve Entrapment  Ulnar nerve compression at the elbow is the second most common nerve entrapment of the upper extremity, after carpal tunnel syndrome  Flexion of the elbow causes increased tensile load on the ulnar nerve as well as increasing the pressure within the cubital tunnel up to 20 times the pressure at rest  People with recurrent anterior dislocation of the ulnar nerve. This abnormal nerve translation has been reported in 16% to 20% of asymptomatic people.  Risk factors for ulnar nerve dis- location include cubitus varus deformity, an absent or lax ligament of Osborne, a hyper- trophic medial head of the triceps, or an accessory head of the triceps  Compression of the ulnar nerve may occur at four different locations along its course at the elbow from proximal to distal: 1) the intermuscular septum due to the arcade of Struthers; 2) at the medial epicondyle at the entrance to the cubital tunnel; 3) within the cubital tunnel; 4) at the flexor-pronator aponeurosis between the heads of the flexor carpi ulnaris as the nerve enters the forearm Fig. 1—Axial proton density MR image through cubital tunnel shows olecranon process (OP), joint capsule, and posterior bundle of medial collateral ligament (round-tailed arrow), medial epicondyle (ME), and ligament of Osborne (straight black arrows). Ulnar nerve (white arrow) is surrounded by fat. 30-year-old man with cubital tunnel syndrome. A, Axial proton density MR image shows ulnar nerve (round-tailed arrow) compressed against medial epicondyle (ME) by anconeus epitrochlearis (straight arrow). Sagittal proton density MR image shows ulnar nerve (arrow) compressed against medial epicondyle (ME) by anconeus epitrochlearis (AE) RADIAL NERVE  Segmental level: C5-T1 Cord level: Major derivative of posterior cord Pathways:  Arm: Passes through the axilla and innervates the triceps at the lower border of the axilla. It continues posterior to the humerus via the spiral groove to the radial border of the humerus.  Elbow: Approximately 10-12 centimeters proximal to the lateral epicondyle it pierces the intermuscular septum to come into the anterior flexor compartment of the humerus. It lies between the brachialis and the extensor muscles of the lateral epicondyle. It innervates the muscles of the elbow and divides into a superficial radial sensory branch and deep posterior interosseous motor branch.  The posterior interosseous nerve immediately innervates the ECRB and passes through “Arcade of Frohse” in the supinator muscle. It then extends dorsally down the interosseous membrane. The nerve must also pass through the “supinator tunnel or canal which is formed by the two heads of the supinator muscle. The posterior interosseus nerve travels down the radial aspect of the forearm posteriorly becoming superficial in the distal half of the forearm and terminating there. RADIAL and POSTERIOR INTEROSSEUS NERVE  Nerve compression of the radial/posterior interossesous nerve is caused by both intrinsic and extrinsic factors. In addition to the factors listed below, compression can be caused from tumors, septic arthritis in the elbow, synovitis secondary to rheumatoid arthritis, lipomas, hemangiomas, ganglion cysts, and other masses. Also, a tardy palsy may occur secondary to compression by a callus in a healing fracture at any of the locations.  The close proximity of the radial/posterior interosseous nerve to bony, muscular, tendinous, and arterial structures put it at risk for entrapment. There are several regions where compression of the radial/posterior interosseous nerve occurs – in the axillary/proximal region, at the elbow, and very rarely at the wrist  Compression can be caused from tumors, septic arthritis in the elbow, synovitis secondary to rheumatoid arthritis, lipomas, hemangiomas, ganglion cysts, and other masses. Also, a tardy palsy may occur secondary to compression by a callus in a healing fracture at any of the locations. RADIAL NERVE High radial nerve (Above elbow) compression sites and syndromes:  Close proximity of the radial nerve to the radial groove of the humerus puts the nerve at risk for compression against the bone, being severed secondary to a fracture, or, compressed by either orthopedic plates to repair a fracture or by a callus during bone healing  Close proximity of the radial nerve to the medial and lateral head of the triceps, or a fibrous origin of the lateral head of the triceps leading to injury during strenuous activity  Compression secondary to axillary crutches  Secondary to “windmill” pitching in competitive softball  “Saturday Night Palsy” – arm draped over a chair or hard surface as patient is asleep or intoxicated, “Honeymooners Palsy”- caused by one honeymooner resting on the other’s arm  External compression and trauma most common cause of problems in this region At the elbow RADIAL NERVE  Entrapment by fibrous bands around the anterior margin of the radial head  Entrapment by the “Leash of Henry”- vessels from the radial recurrent artery  Entrapment by the tendinous edge of Extensor Carpi Radialis Brevis  Entrapment at the Arcade of Frohse (proximal entrance of the posterior interosseous nerve into the supinator muscle)-this structure is soft in childhood and can become fibrous in adulthood with fibrous occurrence ranging from 30-50% in cadaver studies but present in 80% of patients who undergo radial nerve decompression at the elbow  Entrapment at the distal entrance of the posterior interosseous nerve from the supinator muscle  Compression secondary to elbow synovitis in patients with rheumatoid arthritis  Compression secondary to Monteggia fracture (fracture of proximal ulna in combination with posterior dislocation of the radial head)  Radial nerve compression often coexists with compression syndromes of other nerves or with other conditions such as lateral epicondylitis 33-year-old woman with radial tunnel syndrome. Sagittal proton density MR image shows mass (white arrow) displacing radial nerve (black arrows). 47-year-old man with posterior interosseous nerve syndrome. Axial fat-suppressed T2-weighted MR image shows denervation edema in posterior aspect of supinator muscle (S), extensor digitorum communis muscle (straight arrow), and extensor carpi radialis brevis muscle (round-tailed arrow). DERMATOMES of the FOREARM and HAND Pathologies/Injuries of the Elbow  Traumatic Arthritis  Injury of any severity, may lead to capsular pattern. . Flexion limited, extension markedly limited, and painful. Rotation - full R.O.M., painless or painful rotation which Indicates head of radius chipped or cracked.  Complications: May lead to myositis ossificans.  Osteoarthritis  Insidious onset in late middle-age. The cartilage of the lateral compartment of the elbow (humero-radial) is preferentially affected as compared with that of the medial compartment  Follows fracture involving an articular surface.  Aching after considerable exertion and loss of full extension. Radial Head fracture Fracture at the Elbow  Head of Radius. One of the most common fractures of upper limb in young adults. Cause: fall on outstretched hand. Force transmitted axially along the shaft of radius.  Clinical-cartilage covering articular surface often badly bruised often at the capitellum.  This leads to joint stiffness, elbow does not tolerate manipulation or forced passive movements. b. Osteoarthritis may be delayed by excision of radial head.  Fracture of Coronoid process. Seldom fractured except in association with posterior dislocation of elbow. Marked displacement presented by strong aponeurotic fibers that invest the bone.  Fracture of upper end of ulna with dislocation of head of radius. (Monteggia Fracture dislocation)  Fall with forced pronation of forearm or direct blow on back of upper forearm. Displacement - ulna angled forwards, head radius dislocated forwards. Capitulum Fracture Monteggia Fracture-Dislocation Fractures of the Elbow  Fracture of Olecranon process. Cause: fall on point of the elbow, usually in an adult. Clinical: fracture line nearly always enters joint near middle of trochlear notch. Complications. Non-union - extension weakened. Osteoarthritis - unlikely to become severe unless used for heavy work.  Fracture of upper end of ulna with dislocation of head of radius. (Monteggia Fracture dislocation)  1. Cause: fall with forced pronation of forearm or direct blow on back of upper forearm. 2. Displacement - ulna angled forwards, head of radius dislocated forwards.  Often requires surgical repair ORIF with immobilization 4-6 weeks  4-6 weeks immobilization in non-displaced without surgical stabilization Monteggia with proximal fracture Elbow Dislocation Elbow dislocations  Elbow dislocations are the most common major joint dislocation second to the shoulder  Most common dislocated joint in children and account for 10-25% of injuries to the elbow  Posterolateral is the most common type of dislocation (80%)  Predominantly affects patients between age 10-20 years old  Mechanism for posterolateral dislocation  Usually a combination of axial loading, supination/external rotation of the forearm, andvalgus posterolateral force  A varus posteromedial mechanism (combined with axial load and forearm external rotation) has also been reported  Posterior dislocations may involve more than one injury mechanism Ellbow Dislocation  Often associated with full or near full capsuloligamentous disruption/tears  Progression will often be from lateral to medial with the LCL failing first and may result in avulsion of the the lateral epicondyle  Followed by the MCL depending on the forces that are generated  Elbow dislocation with no associated fracture  Accounts for 50-60% of elbow dislocations  Elbow dislocation associated with a LUCL tear, radial head fracture, and coronoid tip fracture Radial head fractures occur in up to 10-15% of elbow dislocations Radial head dislocation often Annular ligament tear Varus posteromedial rotatory instability Elbow dislocation injury associated with an LCL tear and a coronoid fracture (Terrible triad)  Coronoid fracture characterisitics medial facet fracture comminuted  Assessment  Status of the skin - evaluate for open injuries  Presence of compartment syndrome  Neurovascular (Motor and sensory or vascular compromise)  Wrist and shoulder cleared  Concomitant injuries occur in 10-15% of elbow dislocations  Closed reduction with splinting  ensure patient has sufficient analgesia to allow for adequate muscle relaxation  reduction maneuver requires a combination of:  Inline traction to improve coronal displacement  Forearm supination to shift the coronoid under the trochlea  Elbow flexion while placing direct pressure on tip of olecranon  a palpable "clunk" can be appreciated after most reductions Elbow Dislocations  Assess post reduction stability  Elbow is often unstable in extension  Elbow is often unstable to valgus stress  Test by stressing elbow with forearm in pronation to lock the lateral side  place post-reduction posterior mold splint in flexion and appropriate forearm rotation  splint in at least 90° of elbow flexion  if LCL is disrupted - elbow will be more stable in pronation  if MCL is disrupted - elbow will be more stable in supination  obtain post-reduction radiographs  If joint is concentric, immobilize (5-10 days) and start early therapy  Obtain repeat radiographs at 3-5 days and 10-14 days to confirm reduction Elbow Dislocations Initial Rehab Immobilize for 5-10 days Immobilization for >3 weeks results in poor final ROM outcomes Early Supervised (PT) active and active assist range-of-motion exercises within stable arc Extension block brace is used for 3-4 weeks Proceed with light duty use 2 weeks from injury Late rehabilitation Extension block is decreased such that by 6-8 weeks after the injury full stable extension is achieved Once Full pain free extension is obtained the progression should begin increasing both open and closed chained exercises varying loads to assist with return to prior activity This should lead to tri-joint movements, and combinations of isometric, concentric, and eccentric loading Consider ways to load load ligaments in both flexion and extension in combo with closed and open chain exercises Elbow Dislocations  ORIF of coronoid, radial head, repair of LCL +/- MCL  Approach depends on the pathology  Kocher approach (ECU/anconeus) Used to address the LCL complex, common extensor tendon origin, coronoid, capitellum, and/or radial head fractures When approaching joint (ie, for radial head fractures) during deep dissection, make incision slightly anterior to midline of the radial head to protect the posterior fibers of the LCL complex take care with retractor placement to avoid injury to the PIN  medial approach used to address the MCL, flexor/pronator mass origin, and/or comminuted coronoid fractures identify and protect the ulnar nerve Coronoid and Radial Head Fractures  Coronoid Fractures  ORIF  rarely needed, as most fractures involve only the coronoid tip (proximal to insertion of brachialis)  Typically approached laterally, but can also be addressed via a medial approach, especially if comminuted  Radial head Fractures  ORIF when placing fixation on the proximal radius, one must be aware of the "safe zone" (a 90° arc in the radial head that does not articulate with the proximal ulna)  The "safe zone" can be identified by its relationship to Lister's tubercle and the radial styloid  Radial head Arthroplasty is indicated if radial head can not be reconstructed  If radial head is replaced the replacement should be anatomic and restore normal length/size  this improves the varus and external rotatory stability of the elbow, but stability isn't restored until LCL is addressed. Excision of the radial head leads to varus/external rotatory instability when the LCL function is absent Complications that Can Occur  Loss of full elbow extension is the most common problem yo occur after simple closed elbow dislocation  Early AROM is essential and even at times progressive splinting is used as inflammatory process diminishes  Posterior medial instability (Varus)  Injury to the LCL with fracture to the anteriomedial facet of the coronoid  Fixation is needed to prevent future arthrosis and outcomes  Neurovascular Injuries  brachial artery injuries (rare) typically associated with open dislocations  ulnar nerve injury typically results from stretch  median nerve injury (rate) typically associated with brachial artery injury  Compartment syndrome  Recurrent Instability  Heterotrophic bone Lateral Epicondylitis/Epicondylopathy  90 percent of cases pain starts at outer side of elbow when lesion lies at common extensor tendon.  Epicondyle is tender. Referred pain along back of forearm often as far as wrist, dorsum of hand. Occasionally the ring fingers ache. Rarely - no pain in forearm.  Referred pain up from elbow to shoulders.  Pain aggravated by grasping and lifting or any exertion with extension of wrist.  Can be constant ache worse at night with stiffness of elbow on waking.  At moment of initial trauma there is no pain. 2. Days later notices ache in forearm with certain movements. Worsens after 14 days.  It is not a tear in tendon that causes pain.  Symptoms result from painful scar that forms later. Lateral Epicondylitis  Tenoperiosteal type.  a. Injury - no exact parallel exists in body. b. Usual lesion - tear between common extensor tendon and periosteum of lateral humeral epicondyle.  c. Tear lies at origin of extensor carpi radialis brevis muscle. d. Early stage: as tear begins to unite, patient using his hand pulls healing surfaces apart again.  Painful scar forms at tenoperiosteal junction with self-perpetuating inflammation.  Later stages: lymphocytic infiltration, scattered areas, fine calcification. Onset is a slow process and demonstrates that a minor tear in tendon is not itself a source of appreciable pain. Influence of cervical spine on elbow pain, function and progression to pathological state Lateral Epicondylitis  Radial nerve entrapment distally causing a false positive or lateral elbow pain and resisted pain compressing nerve further. Secondary muscle guarding and vasoconstriction from the entrapment, however, can lead to primary tissue change consistent with true epicondylitis.  Injection of steroid inhibits mechanism of spontaneous cure.  Gradual widening of gap between the two edges. Finally lose apposition - tension of the scar ceases.  Gap fills with fibrous tissue and heals with permanent lengthening. Stages of repair:  Recent injury: effusion of blood, tissue fluids.  Local hyperemia, round cell infiltration.  Constant pain, diffuse tenderness. Lateral Epicondylitis  Early repair.  Damaged structures being replaced by vascular repair tissue. Torn periosteum - laying down new bone.  Pain only with certain movements. c. Permanent repair.  Granulation tissue becomes avascular fibrous tissue. Symptoms present only if repair has formed adhesions limiting motion.  Complications. Periositiswheretendontornfrom periosteum. Myofascitis, fibrositis of muscle. Involuntary muscle spasm occurs in extensor muscles. Prevents complete elbow extension. Chronic cases  Synovia of extended capsule of elbow that lie beneath and adjacent to extensor muscles becomes affected. Synovial sac may encroach upon the epicondyle. The lateral part of sac is subject to compression by extensor muscles, and this may cause inflammatory reaction of synovia resulting in pain. Lateral Epicondylitis  Clearing and/or treatment of the C6 cervical segment.  This may include treating for hypo or hypomobilities based on exam findings  STM, manipulation, exercises (concentric/eccentric/isometrics) Normalization of joint motion of elbow complex.  Manipulation, if indicated, of adhesion of extensor digitorum to radiohumeral joint capsule.  Mobilization of radial head, if indicated, or mobilization of the radial nerve.  STM to forearm extensors and triceps due to fascial connections to lateral compartment  Therapeutic exercises  Concentrics to biceps/triceps at wrist without gripping  Concentric wrist flex/ext without gripping  Progressing to pain free wrist flex/ext concentric to eccentrics as condition settles and gripping is painfree Medial epicondylitis/epicondylopathy  Defined: lesion of common flexor tendon at medial epicondyle, less common than tennis elbow. Associated with a poor golf swing (Golfer’s Elbow) and with poor technique in swimming (Swimmer’s Elbow).  Much less disabling than tennis elbow.  Pain at inner side of elbow.  Full range of painless movement - elbow.  Resisted movements at elbow painless except  occasionally with pronation. Resisted wrist flexion - pain at elbow (elbow extended). Medial epicondylitis/epicondylopathy  Clearing and/or treatment of the C5 cervical segment.  This may include treating for hypo or hypomobilities based on exam findings  STM, manipulation, exercises (concentric/eccentric/isometrics) Normalization of joint motion of elbow complex.  Mobilization of radial head, med/lat glides of the ulna if indicated, or mobilization of the ulnar nerve  STM to forearm flexors and biceps  Therapeutic exercises  Concentrics to biceps/triceps at wrist without gripping  Concentric wrist flex/ext without gripping  Progressing to pain free wrist flex/ext concentric to eccentrics as condition settles and gripping is pain free  Triplanar movements for more functuional training Olecranon Bursitis  Olecranon bursitis is a condition in which there is an inflammation of the bursa overlying the olecranon process at the proximal aspect of the ulna  The superficial location of the bursa, namely between the ulna and the skin is susceptible to inflammation from a variety of mechanisms, primarily either acute or repetitive trauma  Two-thirds of the cases are bursitis without an infection or non-septic bursitis. Nevertheless this type of bursitis is less common.  Typically affects men between the ages of 30 and 60 years. Two-thirds of cases are non-septic and usually occur with trauma or repeated small injuries lead to bleeding into the bursa or release of inflammatory mediators.  Can be caused by acute injuries (trauma) during sports activities because they can include any action that involves direct trauma to the posterior elbow. Olecranon Bursitis Signs and Symptoms  Patients usually remark a focal swelling at the posterior elbow. The swelling is sometimes painless and is clearly marked off by its appearance as a goose egg over the olecranon process.  Pressure, like leaning on the elbow or rubbing against a table while writing with the ipsilateral hand, are factors which can often exacerbate the pain.  Chronic recurrent swelling is usually not tender and can be visible and palpable  A typical symptom of olecranon bursitis is the frequent bumping of the swollen elbow, because it protrudes further than it usually would.  The Range of motion (ROM) of the affected elbow is usually normal, but in severe cases and be limited  Differential diagnosis would include ruling out RA, Gout, pseudogout, olecranon fracture, and triceps tendon tear Olecranon Bursitis  Manage inflammation early  Promote AROM and concentric vascular exercises  Remove aggravating stimulus or factors based on work or sports  Patient education  Aspiration if needed which may include injection of methyl prednisone and lidocaine from a lateral approach Radial Collateral Ligament  Injury is often associated with trauma and forceful motion into varus. These injuries are commonly associated with a fracture or subluxation at the elbow joint.  Differential Diagnosis  Heterotopic Ossification: Considerable loss of passive range of motion without loss of strength  Malignancy: Severe progressive pain that is not affected by movement  Inflammatory Arthritis: Abnormal systemic signs  Fracture: History of trauma, marked limitations in range of motion and ecchymosis, with pain  Dislocation: Exaggerated boney prominence, effusion, or appearance of elongation of forearm and could affect neurovascular status.  Infection: Sudden swelling without trauma  Vascular Compromise: numbness, tingling, pulse abnormalities  Cervicogenic  Referred From Shpoulder Ulnar Collateral Ligament  The most common UCL injury is a UCL tear that is usually gradual but may also happen in a single traumatic event.  Pain on the inner side of the elbow is the most common symptom of a UCL injury. 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