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Heterotopic ossification following lumbar total disc replacement.
Se-Jun Park1, Kyung-Jung Kang, Seong-Kee Shin
1Department of Orthopedic Surgery, Spine Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-Dong, Kangnam-Gu, Seoul 135-710, Korea.
International Orthopaedics
|July 24, 2010
Summary
Heterotopic ossification (HO) after total disc replacement (TDR) occurs in 30.5% of cases. Mild HO (Class I/II) does not impact motion or clinical outcomes, while severe HO (Class III) reduces motion but not clinical results.
Area of Science:
- Spine surgery
- Biomaterials science
- Orthopedic research
Background:
- Total disc replacement (TDR) aims to preserve spinal motion.
- Heterotopic ossification (HO), the formation of bone in soft tissues, is a known complication after TDR.
- Understanding the prevalence and clinical significance of HO post-TDR is crucial for patient outcomes.
Purpose of the Study:
- To determine the prevalence of heterotopic ossification (HO) following total disc replacement (TDR).
- To assess the clinical relevance of HO by evaluating its impact on segmental range of motion (ROM) and patient-reported outcomes (VAS, ODI).
Main Methods:
- A cohort of 65 patients (82 segments) receiving TDR (ProDisc® or CHARITE™) was retrospectively evaluated.
- Follow-up averaged 45 months, with radiographic assessment for HO using McAfee's classification.
- Patients with and without HO were compared regarding segmental ROM, Visual Analog Scale (VAS) for pain, and Oswestry Disability Index (ODI).
Main Results:
- HO was detected in 30.5% of segments at a mean follow-up of 17 months.
- Class I and II HO (9.8% and 14.6%) showed no significant difference in ROM, VAS, or ODI compared to controls.
- Class III HO (6.1%) significantly decreased segmental ROM (p=0.018) but did not affect VAS or ODI.
Conclusions:
- Mild heterotopic ossification (Class I/II) after TDR is common but generally does not compromise spinal motion or clinical outcomes.
- Severe heterotopic ossification (Class III) can restrict segmental motion, yet clinical function and pain levels remain unaffected.
- The anterior and posterior aspects are the most common sites for HO development post-TDR.
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