• Clinical science

Insertional tendinopathy

Abstract

Insertional tendinopathy is a common disorder caused by repetitive tendon strain and subsequent poor tendon healing. Tendinopathies are typically seen in athletes and people who regularly perform repetitive movements (e.g., typing, assembly-line work, etc.). The Achilles, patellar, humeral epicondylar, and rotator cuff tendons are most commonly affected. Tendinopathies are characterized by pain, especially on movement, and thickening of the affected tendons. The diagnosis is usually established clinically, but can be confirmed with tendon thickening, which is detectable on ultrasound and MRI. Imaging, including x-ray, may also be indicated to rule out possible associated trauma of the bone. Conservative treatment with rest and physiotherapy is successful in most cases, but corticosteroid injections can be used short-term if these methods fail. Surgical debridement of scarred tendon tissue is reserved for patients who do not improve despite at least 6 months of conservative treatment.

Epidemiology

References:[1]

Epidemiological data refers to the US, unless otherwise specified.

Etiology

  • Overuse or overload injury (repetitive, excessive strain), degeneration
  • Skeletal abnormalities with strain on tendons (e.g., genu varum)
  • Acute trauma (laceration, rupture)
  • Risk factors
    • Occupation: athletes, jobs requiring manual labor or repetitive movements involving the same muscle
    • Errors in physical training (e.g., sudden increase in exercise intensity, inadequate rest, hard/uneven training grounds, ill-fitting/inappropriate footwear)
    • Previous tendon injuries
    • Recent use of fluoroquinolones

References:[1]

Pathophysiology

  • Contraction of a skeletal muscle → transmission of force through the tendon to the bone at the point of tendon insertion
  • Repetitive strain; → microtrauma of the tendon trauma → improper healing; → disorientation of the tendon's collagen fiberstendinopathy
  • Hypovascularity → predisposition to hypoxic tendon degeneration

Unlike in cases of tendinitis or tenosynovitis, inflammation plays a negligible role in the development of tendinopathy!References:[1][2]

Overview of insertional tendinopathies

Upper limbs

  • Lateral epicondylitis (tennis elbow)
    • Definition: overuse injury of the hand and finger extensor tendons that originate in the lateral humeral epicondyle
    • Etiology: repeated or excessive pronation/supination and extension of the wrist (e.g., in racquet sports)
    • Clinical features
      • Pain and tenderness over the lateral epicondyle and along extensor muscles
      • Thickening of the tendons
      • Test: The examiner holds the patient's hand with the thumb placed over the lateral epicondyleThe patient makes a fist, supinates the forearm, deviates radially, and extends the fist against the examiner's resistance → pain over the lateral epicondyle
  • Medial epicondylitis (golfer's elbow)
    • Definition: overload injury of the hand and finger flexor tendons that originate in the medial humoral epicondyle
    • Etiology: repeated wrist flexion and forearm pronation (e.g., while playing golf)
    • Clinical features
      • Pain over the medial epicondyle and along flexor muscles, increases with activity; thickening of the tendons
      • Test: Pain is elicited on asking the patient to flex the wrist against resistance, with the elbow held in extension.
  • For rotator cuff tendinitis, see soft tissue lesions of the shoulder.

Lower limbs

  • Iliotibial band syndrome (runner's knee)
    • Definition: common overuse injury of the distal portion of the iliotibial band (over the lateral femoral epicondyle)
    • Etiology: repetitive flexion and extension of the knee (e.g., during running)
    • Clinical features
      • Sharp pain at the lateral knee when the foot strikes the ground; dull aching, constant pain at rest
      • Noble test: The patient lies on their side and the examiner passively flexes the patient's leg while exerting constant pressure on the lateral femoral epicondyle with his thumb → test positive if pain is elicited
  • Patellar tendinitis (jumper's knee)
    • Definition: overuse injury of the patellar tendon at the distal portion of the patella
    • Etiology: repeated jumping (e.g., volleyball, basketball)
    • Clinical features
      • Bilateral in ∼ 30% of cases
      • Commonly seen in adolescents
      • Pain over the anterior aspect of the knee, which is worsened with climbing stairs, walking downhill, or after prolonged sitting
      • Tenderness on applying pressure to the inferior border of the patella
  • Achillodynia (Achilles tendinopathy)
    • Definition: overuse injury of the Achilles tendon
    • Etiology: athletes/individuals who have recently increased their exercise intensity
    • Clinical features: pain and tenderness ∼ 2–6 cm above the insertion of the Achilles tendon
  • Osteitis pubis

References:[3][4][5][6][7][8]

Diagnostics

  • Clinical diagnosis: further workup rarely needed
  • Imaging
    • X-ray: usually normal; possible detection of fractures or periostitis at the site of tendon insertion
    • Ultrasound: tendon thickening; hypoechoic areas within the tendon
    • MRI: increased signal in abnormal tendons ; simultaneous assessment of bone, cartilage, and ligaments
  • Complete blood count: to rule out infection in patients with osteitis pubis

References:[1][8][7]

Treatment

  • Conservative treatment
    • Rest ; cooling/ice for the first 24–48 hours; topical/oral NSAIDs
    • Physiotherapy: stretching and strength training once the pain has subsided
    • Orthotic braces and bands [2]
  • Corticosteroid and lidocaine injections
    • Only considered if conservative treatment has failed
    • Short-term relief; has no long-term benefit .
    • Injection into surrounding tissue, not directly into tendons
  • Surgery
    • Indicated in patients with persistent symptoms despite 6 months of conservative treatment
    • Excision of abnormal tendon tissue; longitudinal incisions (tenotomies) in scarred and fibrotic areas to promote healing

Corticosteroid injections are generally avoided in insertional tendinopathy since they may cause tendon rupture!References:[8][2][9]