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Heterotopic Ossification in Orthopaedic and Trauma surgery: A Histopathological Ossification Score
M Ohlmeier1, V Krenn2, D M Thiesen3
1Department of Joint Surgery, Helios ENDO-Klinik Hamburg, Holstenstrasse 2, 22767, Hamburg, Germany. malte.ohlmeier@helios-gesundheit.de.
Scientific Reports
|December 6, 2019
Summary
Heterotopic ossification (HO) grading in revision hip and knee arthroplasty can be assessed histologically. Lower grades of HO are common, but higher grades may indicate septic revisions.
Area of Science:
- Orthopaedic Surgery
- Histopathology
- Complication Analysis
Background:
- Heterotopic ossification (HO) is a known complication of orthopaedic surgery.
- Current Brooker classification for HO relies on radiological findings.
- Correlation between histological features and Brooker grade is not well-established.
Purpose of the Study:
- To analyze ossification grade of HO tissue in revision hip and knee arthroplasty.
- To propose a novel histologically-based classification system for HO.
- To assess the relationship between HO grade and revision indication (septic vs. aseptic).
Main Methods:
- Collected 50 human HO samples from revision arthroplasty cases (hip and knee).
- Samples underwent double-blinded histopathological analysis.
- Developed a classification system based on ossification grade, necrosis, and osteomyelitis (HOES-Score).
Main Results:
- 33 samples (66%) showed Grade I ossification, 11 (22%) Grade II, and 1 (2%) Grade III.
- Necrosis (4%) and osteomyelitis findings were rare.
- Higher ossification grades were associated with septic revision cases; wear-induced synovitis was also noted.
Conclusions:
- A histological scoring system for HO grading is feasible and can be derived from the presented data.
- Histological grading provides a more detailed assessment than radiological methods alone.
- Findings suggest a potential link between higher-grade HO, septic revisions, and wear-induced synovitis.
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