Interrelation of tropism and angulation parameters of facet joints and results of stabilization surgeries for degenerative diseases of the lumbar spine

Objective. To clarify indications for dynamic and rigid stabilization based on the analysis of correlation between neuroimaging parameters of facet joints (FJ) and clinical outcomes of surgical treatment of patients with degenerative diseases of the lumbar spine. Material and Methods. A total of 141 patients with degenerative diseases of the lumbar spine were surgically treated. Patients were divided into three groups: patients of Group I (n = 48) underwent surgical intervention with artificial intervertebral disc prosthesis; those of Group II (n = 42) – with interbody fusion and combined transpedicular and transfacetal stabilization; and those of Group III (n = 51) – with interbody fusion and bilateral transpedicular stabilization. The correlation between long-term clinical outcomes (pain syndrome according to VAS, functional state according to ODI, and satisfaction with surgical result according to MacNab scale) and preoperative neuroimaging parameters of FJ (degenerative changes according to Fujiwara, facet angle magnitudes, and the presence of tropism) was analyzed. Results. A direct significant nonparametric correlation of neuroimaging parameters of facet angles and FJ tropism with long-term clinical outcomes of surgical treatment according to VAS and ODI was revealed. It was established that good clinical outcomes were achieved with the following preoperative parameters: in Group I, the facet angle was less than 60°, while the presence of tropism had no correlation dependence; in Group II, the facet angle – more than 60°, in the absence of FJ tropism; and in Group III, the facet angle – more than 60°, in the presence of FJ tropism. Conclusion. Objective neuroimaging parameters of the facet angle magnitude of less than 60°, regardless of the presence of tropism, allow performing total arthroplasty. If the facet angle is more than 60°, the rigid stabilization of the operated segment is indicated; in the absence of tropism, a contralateral transfacetal fixation is possible, and in its presence – a bilateral transpedicular stabilization is reasonable.