Heterotopic Ossification
Heterotopic Ossification (HO) in general is the growth of bone cells beyond the normal borders of the normal bone boundaries. It occurs throughout the body and is associated with post-traumatic arthritis, hypertrophic osteoarthritis, rheumatoid arthritis. Surgery is comparable to trauma. Although desirable in fusion, it is not desirable in artificial disc replacement (ADR) surgery and was once a concern in cervical ADR surgery. There is no evidence of clinical problems in lumbar surgery. In the spine HO can result in bone spurs, and autofusion.
Due to surgeon feedback to the manufacturers, implants and guidelines have been redesigned by some manufactures.
Note: Proprietary surgical techniques are used to reduce HO by Prof. Dr. Bertagnoli.
Note: Prof. Dr. Bertagnoli.developed the classifications of Heterotopic Ossification.
Although Heterotopic Ossification (HO) still occurs in patients, clinical symptoms are seldom seen, that is to say, that no restriction of the movement of the interval disc space with the ADR. To understand the four-part classification of HO we point to the Journal of Spinal Disorders & Techniques Vol.16. No. 4 pp. 384-389. To understand incidence rates of heterotopic ossification in cervical artificial disc replacement we point you to The Spine Journal (2013) pp. 408-420.
To our knowledge, HO has never been a clinical problem with lumbar artificial disc replacement patients.