Long-Term Outcomes and Risk Factors for Unsatisfactory Results of Microdiscectomy and Total Arthroplasty for Lumbar Disc Herniation among Employees of Russian Railways

Background : Railway workers are exposed to occupational conditions that contribute to the development and progression of spinal disorders. Surgical treatment in these patients should include rapid and effective functional recovery, as well as full occupational rehabilitation. Objective : To analyze the long-term outcomes of microdiscectomy (MD) and total disk arthroplasty (TDA) for the treatment of lumbar intervertebral disc (IVD) herniations in railway workers and to identify factors predicting the risk of unfavorable postoperative outcomes.Materials and methods: Between 2010 and 2020, a total of 522 surgical procedures were performed for lumbar IVD herniations in railway workers: MD in group I and TDA in group II. Clinical data were retrospectively analyzed for 481 patients at a mean postoperative follow-up of 8 years (320 patients in group I and 161 patients in group II). Particular attention was given to cases with unfavorable treatment outcomes, which were identified in 98 patients (67 in group I and 31 in group II). Results : Based on univariate logistic regression analysis, risk factors associated with the development of unsatisfactory clinical outcomes were determined for each patient subgroup. For patients who underwent MD: BMI of 30-35 kg/m2, high physical workload, substantial reduction in the height of the operated spinal segment relative to the adjacent upper segments, facet joint (FJ) degeneration of grade II or higher according to Fujiwara A., IVD degeneration of grade III or higher according to Pfirrmann C., apparent diffusion coefficient (ADC) value of the operated IVD <1370 mm²/s, and change of profession due to illness. For patients who underwent TDA: age over 40 years, BMI over 35 kg/m2, smoking, disc herniation migration, FJ degeneration greater than grade according to Fujiwara A., FJ degeneration above grade II according to Fujiwara A., IVD degeneration above grade III according to Pfirrmann C., presence of posterior osteophytes, facet angle greater than 60°, Modic type I–II changes in bone marrow and endplates of the operated segment prior to surgery, ADC value of the operated IVD <1200 mm²/s, and inability to maintain preoperative occupational status. Conclusions : The use of the proposed surgical strategy along with preoperative correction of the identified risk factors may reduce the incidence of unsatisfactory clinical outcomes, increase the rate of return to work and decrease the economic burden on the enterprise.