Lateral Epicondylitis (Tennis Elbow): Pathogenesis and clinical findings
Authors: Brett Lavender Reviewers: Alyssa Federico, Liam Thompson, Tara Shannon Gerhard Nikolaus Kiefe* * MD at time of publication
Extrinsic Factors: activities involving repeated forceful use of the extensor-supinator muscle groups (sports including tennis and squash, activities such as painting, carpentry or using certain hand tools)
Intrinsic Factors: age, body weight, nutrition, gender, anatomical variations, joint laxity, systemic disease, muscle weakness / imbalance, vascular perfusion
Micro-tears within extensor-supinator tendons initiating healing process: inflammation, proliferation, and remodeling (see acute wound healing slide)
Continued repetitive strains with inadequate recovery time between activitiesàhealing unable to meet tissue damage
Ineffective revascularization of damaged tissue
MRI or Ultrasound Findings:
Tendon thickening, partial tears, disrupted vascular distribution +/- edema of surrounding tissues
Disorganized collagen formation and scarringà↑ type III ↑ Nerve growth within damaged tissue collagen (most common collagen involved with wound healing) (consequence of healing response)
↑ Tendon thickening
Decreased tensile strength of tendon
Weakness
of the extensor- supinator muscle groups
Lateral Epicondylitis
Tendinosis at the common extensor-supinator origin at the lateral epicondyle of the humerus
Local nerves are compressed by thickened tendon ànociceptors within tendon are activated
Pain with passive wrist Pain localized to flexion or resisted extension lateral epicondyle
Tenderness over the proximal wrist extensor-supinator muscles
Severity ranges from mild to severe based on the effect on patient activities
Mild tendinopathy: patient continues Moderate tendinopathy: patient continues Severe tendinopathy: patient’s daily most activities with minor pain some activities with modifications activities are impacted by severe pain
Legend:
Pathophysiology
Mechanism
Sign/Symptom/Lab Finding
Complications
Published September 25, 2022 on www.thecalgaryguide.com