The influence of heterotopic ossification on clinical and radiological outcomes after total lumbar disc replacement with M6-L prosthesis: a multicenter study

Abstract

Objective. To assess the degree of influence of heterotopic ossification on the motion amplitude of the operated segment and on clinical outcomes in patients after total intervertebral disc replacement. Material and Methods. Results of total replacement of the intervertebral disc with the M6-L prosthesis were analyzed in 74 patients aged 23-45 years. Follow-up period was 36 months. The motion amplitude of operated segments and the degree of heterotopic ossification were estimated. Clinical outcomes were analyzed based on pain syndrome severity according to the VAS and on the level of the back pain-related quality of life according to the Oswestry index. Results. Signs of heterotopic ossification were found in 27 (36.4%) patients: Grade I-in 11 (14.8 %), Grade II-in 14 (18.9 %), and Grade III-in 2 (2.7 %). The mean values of the motion amplitude of operated segments, VAS score and Oswestry index in the group of patients without signs of heterotopic ossification were 11.2° ± 2.7°, 2.8 ± 1.2 cm and 17.3 ± 6.5 %, respectively, and those in the group of patients with signs of heterotopic ossification-11.5° ± 1.2°, 3.4 ± 1.8 cm and 19.8 ± 7.3 %, respectively. Conclusion. Heterotopic ossification following total lumbar disc replacement occurs in 36.4 % of cases. High grade of heterotopic ossification reliably affects the amplitude of segment motion, though there was no significant influence on clinical results in patients.

Molecular and genetic mechanisms of heterotopic ossification

“…В свою очередь, приобретенные формы ГО могут возникать вследствие воздействия некоторых индуцирующих факторов: повреждение мягких тканей при травмах, ожогах или хирургических вмешательствах и перенесенные травмы головного и/ или спинного мозга [3]. Ряд исследователей классифицирует ГО на травматическую, нетравматическую и нейрогенную [4].…”