Elbow Flashcards
Normal arc of motion of the elbow?
If less than 90-100 of flexion what is most likely to be contracted?
Which is worse, flexion or extension deficits?
How to address post traumatic contracture of the elbow?
30° - 130° (extension-flexion) most activities require a 100 degree arc of motion at the elbow to be functional a 30 degree loss of extension is well tolerated by most patients
50° - 50° (pronation/supination)
if less than 90-100° of flexion, posterior band of MCL is likely contracted and should be released
flexion loss causes more dysfunction than extension loss
Addressing flexion in a post-traumatic contracture of the elbow requires releasing the posterior oblique ligament (or band) of the medial ulnar collateral complex.
The medial ulnar collateral ligament is one of the primary static stabilizers of the elbow and is composed of three parts: anterior, posterior and transverse. The MCL provides resistance to valgus and distractive stresses. The anterior oblique fibers (of the anterior bundle) are the most important against valgus stresses. The posterior bundle is involved elbow contractures and releasing it can yield significant flexion gains, without creating valgus instabilit
Primary stabilzers to the elbow:
Primary stabilizers:
* * anterior band of MCL: anterior oblique fibers most important, stabilizes to both valgus and distraction forces
* LCL
* articular congruity between the olecranon, coronoid, and trochlea
Secondary Stabilizers:
* radial head: most important, 30% of valgus stability, most important in 0-30 of flexion/extension
* capsule: primary trestraint to distraction forces in full extension
* anconeus, and lateral capsule: stabilizer to varus force
In addition to capsular release what needs to be release surgically in a elbow contracture
The posterior band of the MCL is attached dorsal to the axis of rotation and has greater variation in length. It increases in length by 9 mm between 60° and 120° of flexion. Posterior band contracture leads to loss of elbow flexion. In contrast, the anterior band of the MCL (AMCL) maintains a constant length (isometric) throughout the entire arc of movement. Anterior capsule contracture leads to loss of extension.
The posterior bundle is a fan-like thickening of the capsule that becomes taut as the elbow flexes well past 90 degrees and exhibits the most change in tension from flexion to extension.
Javelin thrower with torn ulnar collateral ligament (UCL) which has 3 bundles, the most important of which is the ?. The ? provides the primary valgus restraint to the elbow from ?.
torn ulnar collateral ligament (UCL) which has 3 bundles, the most important of which is the** anterior oblique ligament**. The anterior oblique ligament provides the primary valgus restraint to the elbow from 30-120º of flexion.
Medial Ulnar Collateral ligament injuries:
who’s at risk? RF? Physical exam? What would MRI show?
- microtrauma from** repitive valgus stress** leads to rupture of the anterior band of medial UCL
- overhead athletes that place a valgus stress on their elbows (pitchers, javelin throwers)
- Higher pitch velocity, pitch count in youth baseball, deficits in kinetic chain
* UCL primary restraint to valgus stress from 30 to 120 degrees of flexion - MRI findings are helpful in confirming a UCL tear when suspected on physical exam. The “capsular T-sign” can be seen on MRI arthrogram in these patients, which is when contrast extravasates through the tear.
Medial Ulnar Collateral Ligament Injuries are characterized by attenuation or rupture of the ulnar collateral ligament of the elbow leading to valgus instability in overhead throwing athletes. Diagnosis is usually made by a combination of physical exam and MRI studies. Treatment for most individuals is rest and physical therapy. Surgery is reserved for high level overhead athletes such as pitchers.
valgus load on the medial ucl increases with and decreases with? Valgus load is highest in what phase of pitch?
- elbow valgus load increases with poor throwing mechanics and decreases with trunk-scapular kinesis, forearm pronation, dynamic flexor-pronator stabilization
- late cocking/acceleration phase of throwing
- UCL primary restraint to valgus stress from 30 to 120 degrees of flexion
Medical ulnar collateral ligament, what are the 3 components and function?
AOL. POL. transverse ligament
Anterior oblique ligament: strongest most significant stabilizer to valgus stress.
- Anterior band: anterior band is primary restraint to valgus stress, exhibiting nearly isometric strain during elbow ROM. Primary restraint full extension to 85 degrees of flexion
- Posterior band: posterior band exhibits increasing strain during higher degrees of elbow flexion
Posterior oblique ligament: tight in flexion, important for valgus stability beyond 90 degrees of flexion
The transverse band plays no role in joint stability because it originates and inserts on the same bone.
UCL primary restraint to valgus stress from 30 to 120 degrees of flexion
at 25 degrees flexion the olecranon is unlocked from its fossa and the ulnar collateral ligament becomes the most important stabilizer. The posterior bundle is a fan-like thickening of the capsule that becomes taut as the elbow flexes well past 90 degrees and exhibits the most change in tension from flexion to extension.
What structure provides the most static stability for valgus restraint in the elbow?
The anterior band of the ulnar collateral ligament provides the greatest restraint to valgus stress in the elbow. The posterior band is taut in flexion and resists stress between 60 degrees and full flexion. The annular ligament stabilizes the radial head. The flexor/pronator mass are important dynamic stabilizers of the medial elbow.
The anterior band of the anterior bundle is the only portion of the ligament that remains essentially isometric.
Valgus stability of the elbow is primary provided by the ?, with the? acting as a secondary stabilizer, and the ? is a dynamic stabilizer
Valgus stability of the elbow is primary provided by the UCL, with the radiocapitellar joint acting as a secondary stabilizer, and the flexor-pronator mass is a dynamic stabilizer
The anterior band of the anterior bundle is the only portion of the ligament that remains essentially isometric.
How to test for medial UCL instability/pain?
Moving valgus test: abduction of the shoulder to 90°. A valgus force is applied to the elbow, and the elbow is then brought quickly through a complete arc from flexion to full extension. Pain experienced at 70° to 120° of this arc may indicate symptomatic insufficiency of the medial collateral ligament
milking maneuver, performed with a valgus stress on the elbow with the forearm supinated and the elbow flexed around 90 degrees
MR arthrogram in a pitcher what is this finding? Tx?
Ruputure of the medial collateral ligament. Medial UCL injury, full-thickness or partial undersurface tears capsular “T-sign” with contrast extravasation.
Rest, cessation from throwin for 6 weeks. 6 weeks and symptoms/pain have resolved) progressive return to throwing program
Tx for medial ucl injuries: non op vs surgery? Complication of surgery?
red dashed line is the anterior band of the anterior bundle, the dotted black line is the posterior band of the anterior bundle, the blue dotted line is the posterior bundle, and the yellow dotted line is the transverse bundle
Rest, cessation from throwin for 6 weeks. 6 weeks and symptoms/pain have resolved) progressive return to throwing program. 42% return to preinjury level of sporting activity at an average of 24 weeks
Tommy John Surgery: UCL anterior band ligament reconstruction for high-level throwers that want to continue competitive sports. 90% return to preinjury levels.
complication? Transient ulnar nerve neuropraxia remains the most common complication following medial ulnar collateral ligament (MUCL) reconstruction. The ulnar nerve is found between the FCU and FDP muscles in the forearm.
The docking technique for ulnar collateral ligament reconstruction (UCLR) has been shown to have higher rates of return to play and a lower risk of complications when compared to the original Jobe technique. Illustration A shows four commonly used UCLR techniques including (A) Jobe Technique, (B) Docking technique, (C) The David Altchek, Neal ElAttrache Tommy John technique, and (D) Dual Interference Screw technique.
Valgus extension overload (pitchers elbow)
Posteromedial elbow pain related to repetitive microtrauma in throwing athletes.
deceleration / follow-through phase of pitching
radiographs or advanced imaging showing osteophyte formation on theposteromedial olecranon.
First line treatment is nonoperative with rest, activity modifications, and injections. Operative resection of osteophytes and loose bodies are indicated in patients with persistent symptoms.
complications of surgery:
Valgus instability: over resectionof posterior medial ostophyte bast its native marge or more than 3 mm leads to increased stress on MCL and valgus instability,
ulnar nerve injury
concurrent cubital tunnel syndrome in ~25% of cases
Little League elbow:
3 potential sites of injury?
Path?
- Medial epicondyle stress fx; UCL injury, flexor pronator mass strains.
- Repetitive valgus loads w/ throwing on immature skeletal casing tension overload on medial structures.
- RF 80 pitches again, 8 months of playing, 85 mph, continued pitching.
Lateral Ulnar Collateral Ligament Injury (PLRI)
associated with?
L UCL is the primary stabilizer to?
- associated with a traumatic elbow dislocation, and characterized by posterolateral subluxation or dislocation of the radiocapitellar and ulnohumeral joints.
- supination, axial loading, valgus (posterolateral) stress, and elbow extension causes progressive failure of the lateral collateral ligament complex and anterior capsule, resulting posterolateral subluxation of the radial head and external rotation of the semilunar notch away from trochlea
- L UCL primary stabilizer to varus & ER stress
L UCL injury symptoms
most often from traumatic elbow dislocation, supination, axial loads, valus (posterolateral stress)
Exam: pain, clicki/catching with elbow extension, pushing off from arm chair. TTP over LUCL, varus instability.
Lateral pivot shift test
Varus Posteromedial Rotary Instability vs Valagus Posterolateral Instability
Tx for acute elbow reduction:
LCL disrupted, but MCL intact?
LCL + MCL disrupted?
acute reduction followed by immobilization at 90° flexion for 5-7 days
LCL disrupted, but MCL intact? splint in full pronation
LCL + MCL splint in neutral
Simple posterolateral elbow dislocations often have concurrent lateral ligament injury and should be splinted in full pronation in order to tighten the lateral-sided ligaments. Injury to the MCL in isolation is very unlikely, therefore splinting in full supination is not recommended.
A 20-year-old collegiate volleyball player has vague left, nondominant elbow pain. Five years ago, he sustained a dislocation of the same joint and, while he could participate in his sport, he notes that the elbow ‘never felt quite right.The pain is not severe but prevents him from playing sports and he cannot localize the pain to any specific location. Occasionally he will perceive a catching when pushing himself out of a chair but the elbow never locks in one position. Examination reveals full passive and active range of motion in flexion, extension, supination, and pronation. There is tenderness of the lateral elbow during elbow extension with the forearm supinated and a momentary painful clunk is noted. Radiographs and MRI scans are normal. What is the most likely instability?
Posterolateral rotatory instability of the elbow is seen in athletes and frequently follows a previous injury such as a dislocation where the lateral ulnar collateral ligament becomes weakened and attenuated. The ulna supinates away from the humerus and the radius subluxates posteriorly on the capitellum with the forearm supinated and the elbow in extension.
AAOS elbow instability:
Posteromedial rotatory
Posterolateral rotator
Valgus
Varus
Longitudinal forearm
Posterolateral rotatory instability of the elbow is seen in athletes and frequently follows a previous injury such as a dislocation where the lateral ulnar collateral ligament becomes weakened and attenuated. The ulna supinates away from the humerus and the radius subluxates posteriorly on the capitellum with the forearm supinated and the elbow in extension.
Posteromedial rotatory instability is more often seen in association with fracture of the coronoid process following a varus stress to the elbow.
Valgus instability occurs due to an injury to the medial ulnar collateral ligament seen most commonly in throwers from overuse.
Varus instability is rare but results in lateral gapping of the elbow.
Longitudinal forearm instability is seen after an Essex-Lopresti injury.
A 45-year-old tennis player undergoes surgery for chronic lateral epicondylitis. After returning to play, he notes increasing lateral elbow pain with mechanical catching and locking. Examination shows positive supine posterolateral rotatory instability. What ligament has been injured?
LUCL
The patient has sustained an iatrogenic injury to the lateral ulnar collateral ligament. This injury has been reported after lateral approaches to the elbow. The orbicular, annular, and lateral radial collateral ligaments have a much less important role in lateral elbow stability. The anterior band of the ulnar collateral ligament is on the medial side of the elbow and is important for valgus stability.
Distal Biceps rupture:
RF? How does it occur? What is the lacertus fibrosus? Exam? What strength is lost?
Approach? What artery crosses the field.
- sudden eccentric contraction of biceps brachii (arm flexed and forced into extended position)
- RF: anabolic steroids, smoking 7/5x higher risk, hypovascularity,
- biceps inserts on radial tuberosity, lacertus is the bicipital aponeurosis or biceps fascia
- hook test, FP: partial, intact lacertus, underlying BR tendon
loss of more supination than fleion strength
reverse popeye - Surgery: Volar apporach, BR/Pronator teres, recurrent radial artery is usually identified superficial to the biceps tuberosity and may need to be ligated.
Single incision reduces the risk of HO.
Risk of injury to LABCN (lateral cord, branch of MSK) b/t biceps and brachialis over agress retraction. Most common. decreased sensation to the volar radial aspect of the forearm.
PIN: protect PIN by limited lateral retraction and maintaining supination.
- Partial distal bicep tendon tears most commonly occur at the radial aspect of the radial tuberosity insertion
- eccentric contraction: muscle lengthens as it contracts
- nerve injury usually resolve within 3-6 months.
Hook test
examiner’s finger is brought across the antecubital fossa from lateral to medial, and a cord-like biceps tendon should be palpated if intact (Illustration B). If the examiner’s finger is brought from medial to lateral, the robust lacertus fibrosis can be felt and may lead to a false-negative hook test. This simple test maneuver has been shown to be both sensitive and specific for ruptures and thus has appeared on numerous standardized tests. . Hook test was performed by one clinician in individuals with distal biceps ruptures and compared to the contralateral, intact arm, and to MRI findings. The hook test showed 100% sensitivity and specificity compared to MRI findings which demonstrated 92% and 85%, respectively.
most common nerve injury with approach for distal biceps repair
ateral antebrachial cutaneous nerve (LABCN). Injury to this nerve would result in lateral volar forearm numbness.
Lateral epicondylitis (tennis elbow)
What causes it?
Pathoanatomy?
Associated condtions?
- eccentric overload at the origin of the common extensor tendon, leading to tendinosis and inflammation of the ECRB.
- micro tear of origin of ECRB, path shows angiofibroblastic hyperplasia, disorganized collagen, no inflammatory cells
- histology: fibroblast hyperplasia, disorganized collagen, vascular hyperplasia
- 5% have radial tunnel syndrome (PIN)
- Exam: pain w/ resisted wrist extension, decreased grip strength, point tenderness at ECRB
- MRI shows increased signal intesnisity at ECRB tendon
- Tx: nsaids, PT, US, counterforce brace, 80-90% improve with nonoperative treatment at 1 year
- Surgery: 2-4% eventually fail non op and require surgery, 6-12 months of non op required. Relase and debridement of ECRB origin
precipitated by repetitive wrist extension and forearm pronation
Radial tunnel syndrome: palpation 3-4 cm distal and anterior to lateral epicondyle, pain w. resisted 3rd finger exention, pain w/ resisted forearm supination
Medial Epicondylitis
- eccentric overload of the flexor-pronator mass at the medial epicondyle.
- dx: tenderness around the medial epicondyle made worse with resistedforearmpronation and wrist flexion.
- associated with ulnar neuropathy
- angiofibroblastic hyperplasia, inflammation uncommon
- tx: activity modification, PT passive stretching, bracing, NSAIDs.
- surgery: open debridement of PT-FCR, reattachment of flexor pornator group if 6 months of non op fails in compliant patient.
Triceps rupture:
RF? Mechanism? Repair?
RF: systemic illness (hyperparathyroidism, renal osteodystrophy, OI, RA, type I DM) fluoroquinolone use anabolic steroid use anabolic steroid use local steroid injection local steroid injection
mechanism: forceful eccentric contraction or FOOSH
exam: inability to extend against resistance, modified thompson test
surgery: transosseus tunnels or suture anchors: no difference in biomechanical strength or functional outcomes betweentransosseous bone tunnelsand suture anchors higher re-rupture rate and complication rate noted with transosseous repair compared to suture anchor repair
inability to extend elbow against resistance not always present – some patients are able to extend elbow against resistance if intact lateral expansion or compensating anconeus muscle
Total elbow arthroplasty (TEA) has the longest average implant survivorship in
patients with rheumatoid arthritis, above those seen in TEA done for fractures, flail elbow, osteoarthritis, and post-traumatic arthritis. Implant options have traditionally shown best results with semiconstrained TEA designs. Unconstrained TEA is least preferred for late-stage rheumatoid arthritis where there is significant capsuloligamentous instability and bony erosion. Unconstrained (unlinked or resurfacing prosthesis) TEA depend on intact bony and ligamentous constraints for stability. These are appropriate for humeroulnar conditions with intact collateral ligaments and radiocapitellar articulation e.g. osteoarthritis, post-traumatic arthritis, intra-articular distal humerus fracture, and malunion of the distal humerus. Conditions with increased risk of instability (ligamentous injury, rheumatoid arthritis) will benefit from a linked or semiconstrained prosthesis.
Outcomes for RA total elbow arthroplasty?
Post traumatic arthritis tea outcomes?
92.4% rate of survivorship free of revision at 10 years; however very high complication rate (14%) triceps avulsion deep infection periprosthetic fracture aseptic loosening
post traumatic group: 5 year survivorship
most achieve functional ROM and patient satisfaction
high complication rate (27-43%)
high re-operation rate (25%)
elbow anatomy
aconenus dynamic constraint to
Dynamic constraint to varus and posterolateral rotatory instability
Lateral condyle-ulna
radial nerve
What type of nerve palsy is most common following elbow arthroscopy?
What is the most commonly reported complication following elbow arthroscopy?
- Transient ulnar
- Transient neurapraxia
- Transient ulnar nerve palsy is the most common palsy following elbow arthroscopy. The ulnar nerve is most frequently affected, followed by the radial nerve. Injury to the other nerves has been reported but less frequently. The complication rate following elbow arthroscopy is reported at 5%. The most commonly reported complication is transient neurapraxia, with nerve transection remaining an unfortunate and rare event. While infection remains the most common serious complication, it is uncommon (0.8%). Synovial cutaneous fistula and compartment syndrome, while reported, are the least frequent complications of elbow arthroscopy.
When the elbow is extended and an axial load is applied, what percent of stress distribution occurs across the ulnohumeral and radiohumeral articular surface, respectively?
ulnohumeral 40%
radiohumeral 60%
When load is applied to the wrist, most of the stress is absorbed by the radius. As the load is transferred through the forearm, the interosseous membrane transfers some of the load from the radius to the ulna. The load at the elbow is distributed with 40% at the ulnohumeral articulation and 60% at the radiohumeral articulation.
Figure 1 shows a coronal T2-weighted MRI scan. What is the name of the labeled torn structure?
LCL, and it is avulsed from the lateral humeral epicondyle. This is the most common site of injury for the LCL.
The biceps and brachialis tendon insertions are not well visualized in this section. The MCL and flexor/pronator origin are intact.
Elbow Arthroscopy dangers:
Portals:
Proximal anterolateral
Proximal anteromedial
anteromedial?
Additional structures at risk?
- The radial nerve: proximal anterolateral portal.
- The ulnar nerve: proximal anteromedial portal. 3 to 4 mm, nerve is posterior to intermuscular septum so must remain anterior
- The medial antebrachial cutaneous nerve: anteromedial portal. portal incisions should be just through the dermis and not deep into the subcutaneous tissue to prevent injury to the nerve
- The ulnar nerve is located directly superficial to the joint capsule in the posterior medial gutter
- The lateral UCL, located deep to the extensor carpi radialis brevis, is at risk for iatrogenic injury during arthroscopic débridement for lateral epicondylitis.
The average distance between the medial portal and the median nerve is greater than the distance between the lateral portal and the radial nerve or posterior interosseous nerve. The radial nerve lies close to the anterior capsule at the mid-aspect of the radiocapitellar joint. A proximal anterolateral portal often is used in favor of the direct lateral portal because the risk of neurovascular injury decreases as the portal is moved more proximally
A right-handed 44-year-old construction worker reports pain and limited range of motion in his right elbow that has limited his ability to work for the past year. Examination reveals range of motion from 60 to 90 degrees, and he has pain at the extremes of flexion and extension. Pronation and supination are minimally restricted. Anti-inflammatory drugs have failed to provide relief. A radiograph is shown in Figure 1. Management should now consist of
ulnohumeral arthroplasty and ulnar nerve decompression.
Patients with severely limited preoperative elbow extension of more than 60 degrees and flexion of less than 100 degrees are at risk for ulnar nerve dysfunction postoperatively and should undergo a concomitant ulnar nerve decompression. Nonsurgical methods are unlikely to improve his chronic condition. Elbow arthroplasty is contraindicated for patients in this age group and with this diagnosis.
What artery provides the only direct vascularizaton to both the intraneural and extraneural blood supply of the ulnar nerve just proximal to the cubital tunnel?
The inferior ulnar collateral artery provides the only direct vascularization to the nerve and is located in the region just proximal to the cubital tunnel.
superior ulnar collateral, inferior ulnar collateral, and posterior ulnar recurrent arteries provide consistent vascular supply to the ulnar nerve. This supply is segmental in nature. No identifiable direct anastomosis is seen between the superior ulnar collateral and the posterior ulnar recurrent arteries. The inferior ulnar collateral artery provides the only direct vascularization to the nerve and is located in the region just proximal to the cubital tunnel. The segmental nature of the blood supply to the ulnar nerve underscores the importance of its preservation during transposition.
A 20-year-old man sustained an injury to his arm during a tug-of-war contest. An MRI scan is shown in Figure 1. What is the most likely diagnosis?
The MRI scan reveals a transection of the biceps muscle. The underlying brachialis is intact. This injury can occur as a result of a cord wrapped around the upper arm. Care should be taken to ensure that there is no concurrent vascular injury.
tx?
ORIF of capitellum
The patient has a type I (Hahn-Steinthal) capitellar fracture that is best seen on the lateral radiograph. If a fracture fragment is seen proximal to the radial head, a capitellar fracture is the most likely injury because radial head fractures do not migrate proximally. The fragment is large enough for fixation. Excision is the preferred treatment for small shear osteochondral type II (Kocher-Lorenz) capitellar fractures. Closed reduction usually is not successful because of rotation of the displaced fragment.
An MRI arthrogram of the elbow is shown in Figure 1. Based on these findings, what is the most likely diagnosis?
Rupture of the medial collateral ligament
Which of the following lateral elbow radiographic findings is most consistent with a distal triceps tendon tear?
A posterior “fleck” sign, also known as a Dunn-Kusnezov Sign is when a small portion of the tip of the olecranon avulses with a full thickness triceps tendon rupture.
While generally thought of to be pathognomonic for this injury, a systematic review found that it was reported in 61% of cases. Traction enthesophytes of the olecranon may be seen with distal triceps tendon injuries, but not as closely associated with full thickness tendon injuries.
Medial epicondylitis most commonly affects the origins of the
pronator teres and the flexor carpi radialis.
When performing elbow arthroscopy, it is often necessary to evaluate the posterior compartment. When entering the posterior compartment of the elbow, what are the two safest and most commonly used portals?
The posterior portal created 3 cm proximal to the tip of the olecranon and the posterior lateral portal created 3 cm proximal from the tip of the olecranon and just lateral to the triceps
The posterior portal created 3 cm proximal to the tip of the olecranon and the posterior lateral portal created 3 cm proximal from the tip of the olecranon and just lateral to the triceps are the “workhorse” portals of the posterior compartment and although relatively safe, risks exist. The radial nerve proximity averages 4.8 mm (3 to 8 mm) from the posterolateral portal. The central posterior portal is close to 20 mm from the ulnar nerve.
Intraoperative photographs of a left elbow. A, Superficial anatomy of the medial aspect of the elbow. The ulnar nerve (UN) is traced. B, Superficial anatomy of the lateral aspect of the elbow. DPP = direct posterior portal, LE = lateral epicondyle, ME = medial epicondyle, P ALP = proximal anterolateral portal, P AMP = proximal anteromedial portal, PLP = posterolateral portal, RH = radial head, * = soft spot, ** = mid-anterolateral portal, which is helpful for placement of retractors to improve visualization. (Reproduced from Keener JD, Galatz LM: Arthroscopic management of the stiff elbow. J Am Acad Orthop Surg 2011;19[5]:265-274.)
