Anterior cervical discectomy and fusion prognosis
Anterior cervical discectomy and fusion (ACDF) has demonstrated good results in terms of pain relief and patient satisfaction 1).
Several groups report their results of Anterior cervical discectomy and fusion (ACDF) using different techniques: allograft, autograft, cages with different designs and anterior cervical plates dynamic or not, with as most important outcome that the use of autograft is superior to allograft and that the postoperative neck pain after surgery is relieved quicker after ACDF 2) 3) 4) 5).
It has been considered as the golden standard for this kind of surgery. However, ACDF has not been proven to be better than anterior cervical discectomy without fusion (ACD) 6).
Workers' Compensation Population
Despite length of symptom duration prior to anterior cervical discectomy and fusion in Workers' Compensation patients, demonstrated improvements in disability and arm pain. Patients with a lesser symptom duration (SD) also demonstrated improvements in physical function and neck pain. Patients with a lesser SD demonstrated superior scores in physical function, pain, disability, and mental health and were more likely to achieve clinically significant improvement in physical function. Patients with a greater symptom duration SD were more likely to achieve clinically significant improvement in mental health 7).
Work Ability
Purpose Information on work ability after ACDF and postoperative rehabilitation is lacking. The aim of a study is therefore to investigate the work ability benefits of a structured postoperative treatment (SPT) over a standard care approach (SA) in patients who underwent anterior cervical decompression and fusion (ACDF) for cervical radiculopathy and factors important to the 2-year outcome. Secondary outcome and prediction model of a prospective randomized controlled multi-centre study with a 2-year follow-up (clinicaltrials.gov NCT01547611). The Work Ability Index (WAI) and Work Ability Score (WAS) were measured at baseline and up to 2 years after ACDF in 154 patients of working age who underwent SPT or SA after surgery. Predictive factors for the WAI at 2 years were analysed. Results Both WAI and WAS significantly improved with SPT and SA (p < 0.001), without any between-group differences. Thoughts of being able to work within the next 6 months, Neck Disability Index (NDI), and work-related neck load explained 59% of the variance in WAI at the 2-year follow-up after ACDF. Conclusions Patients improved over time without group differences, suggesting the improvement to be surgery related. Expectation to work within the next 6 months, self-reported neck functioning and work-related neck load were important to work ability and are central factors to ask early after ACDF, to identifying further interventions promoting return to work 8).
Sagittal alignment
Segmental alignment in cervical spine instrumented segments is an independent factor in the analysis of results after ACDF procedure and can be modified during follow-up by cage subsidence, nonunion, and adjacent segment degeneration. It has been reported that local kyphosis at the fused segment is observed in only 13% of patients with single-level fusion, but in 53% of patients with multiple-level fusion 9).
Sagittal profiles of the spinal cord have been hypothesized to influence loads on spinal tissue and influence outcome after spinal surgery 10) 11). It is believed that ACDF surgery maintains sagittal alignment superiorly to ACD surgery, which should result in a better outcome after surgery and thus on the long term in less disability for the patients. Studies on sagittal alignment in the cervical spine have mainly focused on laminoplasty or arthroplasty 12) 13) showing a proper radiological position on the short term. Despite these radiological findings, clinically there has been no significant improvement in outcome on the longer term 14). Moreover, it has also been published that single-level procedures may lead to a local kyphosis, but do not influence the sagittal alignment as much as multi-level surgery 15).
Although, initially the postoperative outcome is good in more than 90% of the patients, the outcome score on the longer term gradually decreased as the follow up time after surgery increased in a subgroup of the patients. Patients who are doing well after surgery are found without a significant difference at all time points, however patients with moderate to severe complaints can be found increasingly in time after surgery. The increase of complaints at the time of the survey may be the result of ongoing degenerative effects. Only a few studies have been published focusing on a long follow-up period after cervical spine procedures compared to ACDF and therefore it is hard to address the ongoing degenerative effects in the cervical spine 16).