Lateral Elbow Tendinopathy - 'Tennis Elbow' -

Definition

The eponymously named ‘tennis elbow’ encapsulates the diagnosis of a lateral elbow tendinopathy or ‘Lateral Epicondylitis. This typically involves disruption of the tendon matrix of ECRB or ECRL, near the common extensor origin

The most common diagnosis for patients presenting with elbow pain, Affecting 1-3% of adults annually.

Lateral elbow tendinopathy is cause by a tendinopathy of the extensor muscles which attach at the CEO (lateral epicondyle)
The Extensor Carpi Radialis Brevis (ECRB) tendon is the most commonly affected tendon in elbow tendinopathy, followed by the Extensor Carpi Radialis Longus (ECRB).
Tendinopathy is a relatively newly coined term that captures the lifecycle of a tendon as it responds to stress. There are typically thought to be 3 stages.

Reactive tendinopathy
- A tendon responding to a sudden change in load, or an acute stressor (trauma). Localised inflammation, structurally remains intact and indectectable, with limited change to the tendon matrix or collagen integrity
- This is an entirely reversible and physiological process
Dysrepair tendinopathy
- Following stage 1, if there remains to be excessive loading there will begin to be dysregulation of the collagen and tendon matrix, hypervascularity and neural ingrowth..
Degenerative tendinopathy
- Chronic overloading condition, disorganised collagen, increased tendon matrix breakdown, further increased vasculairty and neural ingrowth. Thick and structurally weak tendons with a greater chance of tendon rupture.

The diagnosis of ‘tennis elbow’ is largely a clinical diagnosis, that requires very minimal investigation other than a comprehensive clinical examination. Further imaging is only necessary if there is doubt re diagnosis or if the injury is not responding well to exercise based therapy
History
- Onset
  - There are 2 clinical presentations of lateral elbow tendinopathy.
  - The most common has an insidious onset 24-72 hours post activity unaccustomed to the patient involving repeated wrist extension (e.g laying bricks over weekend, using screw driver etc)
  - Sudden onset elbow pain, in situation of single instance of exertion involving the wrist. The insidious onset is thought to correspond to larger macroscopic tendon tears.
- Activity type
  - Activities of repetitive motion, requiring gripping or elbow extension e.g tennis, squash or occupation such as brick laying, sewing
- Change of activity:
  - New physical activity or change in load to pre-existing exercise
  - E.g hitting heavy tennis balls, poor technique in hitting ‘late’ requiring more forearm strength to compensate, change of raquet.
- Location of pain
  - Typically 5cm distal to the lateral epicondyle
- Associated features
  - Paraesthesia (typically radial nerve distribution), subjective feeling of weakness

Examination
Look
- Joint deformity
- Inflammation
- Redness
Feel
- Palpation at CEO (Lateral epicondyle)
- Insertional (at lateral epicondyle)
- Mid-substance lesion (typical 1-2cm distal of lateral epicondyle)
- Tissue tightness or hypersensitivity
Move
- Reproducible pain namely on wrist extension when wrist is extended and forearm pronated.
- Particularly on Wrist extension (ECRB)
  - Pronated and extended position is of the best sensitivity as ERCB also acts synergistically to anchor the 3rd MCP to allow extension to take place at the digits.
- Middle finger extension (ECRL)
Neurovascular provocation test
- Radial nerve bias
Cervical spine
- Typically decreased ROM lateral flexion at C-spine given radial nerve provocation testing.

AP/Lateral view of elbow
- Would expect a normal XR, however, may show signs of calcification in the extensor musculature (minority of patients)
Xray can assist in ruling out other differential diagnosis

The cavet of all US requires experienced ultrasonographer
Increased thickness to extensor tendon, distortion of tendon architecture, hypo echoic appearance of tendon

Limited utility
Potential thickening, swelling and destruction of tissue architecture at extensor tendons.

No single treatment is totally effective, and like all orthopaedic injuries a multi-disciplinary approach is probably the most useful for patient.
Goals of treatment
- Analgesia
  - RICER (Rest, Ice, Compression, Elevation, Re-assess) in the early phase
  - Bracing or Taping
    - Bracing has been shown to increase forearm extensor stretch tolerance however does not improve strength or proprioception.
    - De-loading taping (diamond taping technique) has been shown to reduce pain through reducing tissue stress.
  - Isometric exercises
    - Isometric wrist hold
  - Medication (Paracetamol, NSAIDs, where appropriate)
  - Electrotherapy (2nd line)
  - Cortisone injection (2nd line) (usually if physiotherapy fails or pt unable to engage in exercised based strengthening due to pain)
    - Injected to the point of most severe pain or around ERCB attachment site.
    - Counsel pts that conservative therapy has a success rate of around 80% in 12 months.
  - Platelet-rich plasma (last line) (PRP)

Address grip strength deficit initially through exercise based management
- Progressively graduated wrist strengthening exercises focusing on wrist extension primarily.
- Pain is expected during exercises, recommend exerting to 4-6/10 pain threshold.
- Manual based therapies can assist to assist in mobilisation, flexibility and engagement in further exercised based strenghting.
Co-ordination based exercises
Correction of pre-disposing factors
- Technique, equipment, jobs
Return to function

Complications
- Surgical wound infections
- Haematoma
- Damage to nerve
- Need for revision surgery

REFERENCE

Rees JD, Maffulli N, Cook J. Management of tendinopathy. The American journal of sports medicine. 2009 Sep;37(9):1855-67.
Keijsers R, de Vos RJ, Kuijer PP, van den Bekerom MP, van der Woude HJ, Eygendaal D. Tennis elbow. Shoulder & elbow. 2019 Oct;11(5):384-92.
Brukner P, Khan K. Clinical sports medicine revised. Australia: McGraw-Hill. 2002;128:145-72.