Harrington Classification (Periacetabular Metastases)
The Harrington classification of periacetabular metastatic disease (Harrington 1981).
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- A SOLITARY metastasis amenable to en-bloc resection with curative intent
- Yes
- Medial wall or quadrilateral plate deficient
- No
- Lateral wall or acetabular roof deficient
- No
Result: class IV
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Class I
- Intact subchondral bone; contained cavitary defect. Cemented total hip arthroplasty.
- Class II
- Medial wall and quadrilateral plate deficient, lateral wall and roof SPARED. Anti-protrusion device / flanged cup.
- Class III
- Medial wall, lateral wall AND roof deficient. Acetabuloplasty with Steinmann pins. THE HARDEST TO RECONSTRUCT.
- Class IV
- A SOLITARY metastasis resectable for CURE. Defined by resectability, NOT destruction. Saddle prosthesis after en-bloc resection.
- Not a ladder
- I to III grade destruction; IV does NOT and is NOT "worse than III". A solitary resectable lesion in an INTACT acetabulum is class IV.
- Corrupted rendering
- Some sources re-define IV as "destruction to the wing of the ilium". That INVERTS it - IV is the patient who might be CURED.
- Reconstructions
- The classes map to NAMED constructs, not severity bands. The class states what operation the bone will accept.
- Not Mirels
- mirels-score grades an impending fracture of a LONG BONE. Different bone, different question.
- Scope
- Does not decide whether to operate, does not estimate survival, and the named reconstructions are 1981-era provenance.
What you enter
- A SOLITARY metastasis amenable to en-bloc resection with curative intent.
- Medial wall or quadrilateral plate deficient.
- Lateral wall or acetabular roof deficient.
Full field descriptions
- A SOLITARY metastasis amenable to en-bloc resection with curative intent. THIS DECIDES CLASS IV ON ITS OWN, regardless of how intact the acetabulum is - class IV is defined by resectability, NOT by destruction.
- Medial wall or quadrilateral plate deficient. With the lateral wall and roof spared this gives class II.
- Lateral wall or acetabular roof deficient. This gives class III - the class described as MOST CHALLENGING to reconstruct.
How this is calculated
Harrington KD. The management of acetabular insufficiency secondary to metastatic malignant disease. J Bone Joint Surg Am. 1981;63(4):653-664. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.