[Influence of preoperative symptom duration on effectiveness of cervical disc arthroplasty in cervical spondylotic radiculopathy patients].

OBJECTIVE: To investigate the influence of preoperative symptom duration on effectiveness of cervical disc arthroplasty (CDA) in cervical spondylotic radiculopathy (CSR) patients.

METHODS: The clinical data of 90 CSR patients who underwent single-segment CDA between January 2008 and March 2020 and met the selection criteria were retrospectively analyzed. Based on preoperative symptom duration, patients were divided into an early intervention group (preoperative symptom duration <24 months) and a late intervention group (preoperative symptom duration ≥24 months). There was no significant difference in baseline data between the two groups ( P >0.05), including age, gender, body mass index, smoking status, surgical segment, preoperative neck disability index (NDI), visual analogue scale (VAS) score, cervical lordosis (CL), C 2 -C 7 range of motion (ROM), disc angle (DA), disc ROM (DROM), and disc intervertebral height (DIH). The early intervention group had a slightly higher preoperative Japan Orthopedic Association (JOA) score than the late intervention group ( P <0.05). Perioperative indicators such as operation time, intraoperative blood loss, and postoperative hospital stay were recorded. The changes of JOA score, NDI, and VAS score at last follow-up compared with those before operation were used to evaluate the clinical efficacy, and the imaging evaluation of CL, C 2 -C 7 ROM, DA, DROM, and DIH was performed before operation, immediately after operation, and at last follow-up. The incidence of prosthesis-related complications, including heterotopic ossification (HO), anterior bone loss (ABL), and prosthesis subsidence, was also assessed at last follow-up.

RESULTS: Patients in both groups were followed up 24-120 months, with an average of 53.4 months. There was no significant difference in operation time, intraoperative blood loss, or follow-up duration between the groups ( P >0.05). However, the late intervention group had significantly longer postoperative hospital stay compared to the early intervention group ( P <0.05). At last follow-up, there was no significant difference in the changes of JOA score, NDI, and VAS score between the two groups before and after operation ( P >0.05). During the follow-up, there was no surgical revision in the two groups, and there was no significant difference in the incidence of HO, ABL, and prosthesis subsidence between the two groups at last follow-up ( P >0.05). Imaging evaluation showed that there was no significant difference in CL, C 2 -C 7 ROM, DA, DROM, and DIH between the two groups at each time point before and after operation ( P >0.05). The intra-group comparison showed that the early intervention group could maintain the immediate postoperative CL at last follow-up, while the late intervention group had recovered to the preoperative level. Additionally, the C 2 -C 7 ROM, DROM, and DA had all recovered to preoperative levels at last follow-up in both groups; meanwhile, the DIH significantly increased immediately after operation and sustained until the last follow-up.

CONCLUSION: Preoperative symptom duration significantly affects the effectiveness of CDA in CSR patients. Patients with preoperative symptom duration ≥24 months have longer postoperative hospital stays and potentially poorer ability to maintain CL compared with patients with preoperative symptom duration <24 months.