The elbow Flashcards
How common is a radial head fracture?
Annual incidence is 28-39 per 100,000 population per year 3% of all fractures 33% of elbow fractures Mean age 43-48 years M:F equal
Describe the pathophysiology of a radial head fracture
At the elbow, the radial head articulates with the capitulum of the humerus and the proximal ulna. This arrangement allows for flexion/extension and supination/pronation of the elbow.
Radial head fractures typically occur via indirect trauma; with axial loading of the forearm causing the radial head to be pushed against the capitulum of the humerus. This most commonly occurs with the arm in extension and pronation.
There are complex ligament structures that can also be damaged in these injuries, which may need further clinical/imaging assessment.
What are the clinical signs of a radial head fracture?
Radial head fractures often present with a history of falling on an outstretched hand followed by elbow pain. The patient may report variable degrees of swelling and bruising at the elbow.
On examination, there may be tenderness on palpation over the lateral aspect of elbow and radial head, with pain and crepitation on supination and pronation. Other clinical features include elbow effusion or limited supination and pronation movements.
Other injuries associated with a fall on an outstretched hand include wrist ligament and bony injuries, and radial head fractures or dislocation. Therefore, the shoulder and wrist joints should also be examined.
How is a radial head fracture investigated?
All patients presenting with suspected radial head fractures require routine blood tests, including a clotting screen and a Group and Save.
Plain AP and lateral radiographs of the elbow are recommended as initial imaging. This should including the joints above and below if their involvement is suspected.
Radial head fractures can be easily missed on plain radiographs and occasionally only an elbow effusion may be seen. Elbow effusions on a lateral projection is termed a “Sail sign”, shown as an elevation of the anterior fat pad, in keeping with an occult fracture.
CT imaging can be useful in evaluating more complex injuries and degree of comminution. MRI imaging can be used to assess suspected associated ligament injuries.
Describe the management of a radial head fracture
Mason type 1 injuries – treated non-operatively, with a short period of immobilization with sling (less than 1 week) followed by early mobilisation
Mason Type 2 injuries – if no mechanical block then can be treated as per a type 1 injury, whilst if a mechanical block is present then these may need surgery (typically an open reduction internal fixation (ORIF))
Mason Type 3 injuries – will nearly always warrant surgical intervention, either via ORIF or radial head excision or replacement (especially in highly comminuted fractures)
What are the features of an elbow dislocation?
Supination valgus and axial load Expect MCL injury BUT Injury begins on lateral side Elbow hinges around strong MCL Radial head either fractures OR Radial head ”squeezed out” LUCL rupture Ulna escapes and capsule unzips from lateral to medial Complete dissociation when MCL torn
What is the terrible triad?
The Terrible Triad injury refers to an elbow dislocation with (1) lateral collateral ligament injury (2) radial head fracture (3) coronoid fracture
This combination of injuries causes a very unstable elbow and is associated with a poor outcome. The forces applied to the joint result from a fall onto an extended arm with rotation, resulting in a posterolateral dislocation. Patients are likely to have recurrent problems with instability, stiffness, and arthrosis.
Treatment revolves around operative fixation of each of the components. Radial head ORIF or arthroplasty with LCL reconstruction and coronoid ORIF. MCL reconstruction is also sometimes undertaken following intraoperative assessment.
What is Lateral Epicondylitis (tennis elbow)?
Epicondylitis is a chronic symptomatic inflammation of the forearm tendons at the elbow.
It is an overuse syndrome in the elbow, caused by microtears in the tendons attaching to the epicondyles of the elbow following repetitive injury. It affects males and females equally, with a peak onset between 35-54 years old.
There are two common types described: lateral epicondylitis (or “Tennis elbow”) and medial epicondylitis (or “Golfer’s elbow”). Lateral epicondylitis is the more common, affecting 4-7 people per 1000 per year.
What causes tennis elbow?
Pathophysiology of elbow
The medial and lateral epicondyles are small bony tuberosities on the distal end of the humerus (Fig. 1). The common extensor tendon attaches to the lateral epicondyle, acting as the common attachment for the superficial extensor muscles of the forearm.
Repetitive overuse of the tendons can cause microtears in the tendon at their origin; the tendon adapts to the multiple tears, leading to the formation of granulation tissue, fibrosis and eventually tendinosis.
Appropriate mechanical load results in homeostasis
Maintained by cells and catabolic and anabolic enzymes
Repair
Remove
Regenerate
Remodel
Inappropriate loading results in upregulation of catabolic cytokines
no mechanical stimulus (tendons need tensile load)
excessive mechanical stimulus (too much tensile load)
Accumulation of damage in tissues
Inappropriate loading results in upregulation of catabolic cytokines
no mechanical stimulus (tendons need tensile load)
excessive mechanical stimulus (too much tensile load)
Accumulation of damage in tissues
Absence of inflammatory cells Tenocytes change characteristics Change in N:C ratio Change in ECM composition Secretory rather than synthesizing cells Collagen fibre disorientation Efficiency of load transmission at insertion Weakened “anchor” at origin Immature non-functional vascular elements (angioneogenesis)
What is the treatment for Lateral Epicondylitis (tennis elbow)?
Patients should be advised to modify their activities, reducing the repetitive actions causing the condition. Simple analgesics alongside topical NSAIDs should be prescribed to help with the pain.
If symptoms persist despite this, corticosteroid injections can be administered, injected into the region around the tendon and can be repeated every 3-6 months.
Physiotherapy can provide longer term relief via stretching and strengthening exercises for wrist and forearm extensors. Orthoses (a wrist or elbow brace) can be used in conjunction with physiotherapy for potential longer-term symptom relief.
Surgical Treatment
Referral to an orthopaedic surgeon may be warranted if the symptoms are not controlled through conservative measures.
Open or arthroscopic debridement of tendinosis and/or release or repair of any damaged tendon insertions may be required. If the tendon has more than 50% damage, tendon transfer may be required to ensure function is retained.
What is a biceps tendon rupture?
Rupture of the distal biceps tendon is an uncommon injury. It can be classified as either complete (through entire tendon) or partial (remains partly intact) tears. These injuries typically occur following sudden forced extension of a flexed elbow.
Those with previous episodes of biceps tendinopathy are at increased risk. Other risk factors for biceps tendon rupture include steroid use, smoking, chronic kidney disease (CKD), or use of fluoroquinolone antibiotics.
What are the clinical features of a distal biceps rupture?
Bruising
(Proximal muscle retraction)
Hook test (from lateral because of lacertus)
Patients will present with sudden onset pain and weakness* at the affected area. Patients often report the feeling of a “pop” during the incident.
Examination demonstrates marked swelling and bruising in the antecubital fossa. As the proximal muscle belly retracts (due to loss of counter traction) a bulge may become evident in the arm; this is termed the “reverse Popeye sign” (Fig. 2).
The Hook test is a special test to identify a potential distal tendon rupture:
The elbow is actively flexed to 90º and fully supinated, the examiner attempts to ‘hook’ their index finger underneath the lateral edge of the biceps tendon (which cannot be done in a ruptured biceps tendon)
Describe the management of a distal biceps rupture
Conservative
Surgical
What are the complications from surgery?
Management
Discussions with the patient regarding the best management option for them in cases of biceps tendon rupture are essential.
As elbow flexion and supination can still occur (albeit weakened), due to the remaining action of other associated muscles, not all cases require surgical management. However, this does come with issues with fatiguability and weakness.
Accordingly, for lower demand patients, a conservative approach may be most suitable. Analgesia and physiotherapy form the mainstay of conservative management, often allowing for significant recovery of muscle strength and function.
Operative Management
For those who warrant surgical management, either an anterior single-incision or a dual incision technique* will be required. The operation involves forming a bone tunnel in the radius and re-inserting the ruptured tendon end.
Surgical repair should occur within a few weeks of initial injury, otherwise the tendon will retract and scar; in missed cases, reconstruction with tendon allograft is therefore often required.
The main complications from surgery are injury to lateral antebrachial cutaneous nerve, posterior interosseous nerve, or radial nerve (rare).
*The anterior single incision involves a single incision in the antecubital fossa, whilst the dual incision technique involves a smaller anterior incision in the antecubital fossa and a posterolateral elbow incision (between the ECU and EDC).
