Calcific Cuff Tendinopathy

Definition

  • Mid-substance calcification of the rotator cuff as part of a metaplasia secondary to hypoxia
  • Different condition to dystrophic calcification of a degenerate cuff which occurs at the cuff insertion

Aetiology

  • Not due to impingement
  • Uncertain
  • HLA-A1
  • Two theories
    • Degenerate calcification theory
      • Dystrophic calcification of degenerate cuff
      • Necrotic fibrillated fibres act as nucleus for calcification
      • Evidence against this theory as dystrophic calcification has different histology
      • Degenerate cuff with true calcific tendonitis rare
    • Reactive Hypoxic Calcification Theory
      • Codman proposed cuff hypoxia as the causative factor
      • Viable cells undergo metaplasia to fibrocartilaginous cells
      • Fibrocartilage cells accumulate intracellular calcification

Epidemiology

  • Peak 40 years
  • Increased Risk
    • Diabetes

Anatomy

Pathology

  • 1. Pre-Calcific Stage
    • Hypoxia → Fibrocartilaginous metaplasia of avascular cuff tenocytes
    2. Calcific StageFormative part of Calcific Stage
    • Calcification accumulates in matrix vesicles
      • extra-cellular matrix of
        • Amorphous GAG rich debris
        • Fragmented collagen fibres around viable chondrocytes
    • Calcification is crystalline & noncrystalline
    • Crystals may be in the form of
      • Phosphates
      • Carbonates
      • Oxalates
      • Hydroxyapatite
    Resorptive Part of Calcific Stage
    • Calcification as a hyperaemic area = “strawberry lesion”
    • Calcium Granuloma forms
      • AKA ” Psammoma”
        • Macrophages
        • Giant Cells
    • Increased intratendinous pressure
    3. Post-Calcific Stage
    • Granulation tissue fills space left by Calcification
    • Forms scar

Classification

Classification (Uhthoff)

Stage Description
Pre-Calcific stageFibrocartilaginous Metaplasia
Calcific Stage~No pain or chronic pain
~”Chalk” appearance
~Well-defined calcification on XR
Formative Stage 
Resting PhaseNo pain or chronic pain
Resorptive Stage~Acute pain
~”Toothpaste & quot
~Fluffy appearance on XR
~Macrophage resorption
Post-Calcific StageArea heals to scar
Classification of Calcific Cuff Tendinopathy

History

  • Pain
    • Usually acute pain due to calcification
    • Acute pain in Resorption phase on background of Absent to mild chronic pain of the Formative Stage
  • No impingement

Examination

  • Feel
    • Tender
  • Move
    • Painful ROM
    • ↓ ROM

Investigations

XRay

  • Calcification typically Supraspinatus mid-cuff
  • Two appearances
    • Painful Resorptive (Type 1)
    • Fluffy
    • Poorly defined margin
      • Irregular density
    • Can rupture into bursa
  • Chronic Formative (Type 2)
    • Discrete, homogenous deposit
    • Well defined margin
    • Uniform density
    • Degenerative changes extremely rare with true calcific tendonitis
    • Different appearance to dystrophic calcification secondary to a cuff tendinopathy

Ultrasound

  • more sensitive than XR
  • ~ 100%

Differential Diagnosis

  • Cuff Tendinopathy
  • Brachial Neuritis
  • Septic Shoulder
  • Biceps Tendinopathy
  • Gout/ CPPD
  • IHD

Treatment

Principles

  • Distinguish Formative vs Resorptive
    • Formative Management
      • Typically Non-Operative

Nonoperative

  • Education
  • Medications
    • Cortisone not recommended
  • Physiotherapy
    • to maintain ROM
  • ? USS
  • Injections
    • HCLA if concomitant impingement

Operative

  • If above fails surgery may be needed
  • Technique (Open)
    • Deltoid split
    • Split fibres longitudinally
    • Scoop out Calcification
    • May need II
    • Repair cuff
    • Acromioplasty if cuff tight

Prognosis