The Oblique Corpectomy, Forgotten but an Effective Procedure? A Systematic Review

Background: Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord dysfunction in elderly. When CSM results in neurological deficits, surgical decompression is often the treatment of choice aiming to prevent further neurological decline. The oblique corpectomy (OC) is an alternative technique for the treatment of CSM opposed to the frequently performed anterior and posterior approaches. The aim of this systematic review is to present up-to-date clinical data on the surgical procedure of OC in patients with symptomatic CSM regarding clinical outcome and related costs. 

Methods: A comprehensive systematic search was performed that adhered to the Preferred Reporting items for Systematic Reviews and Meta-analyses (PRISMA). Articles were identified from the following databases: PubMed, EMBASE, Scopus, Web of Science and Google Scholar. Risk of bias was determined according to the guidelines of the Grading of Recommendations Assessment Development and Evaluation (GRADE). 

Results: Seven prospective, three retrospective, two case-series and one case report were identified including 740 patients. The majority of the studies (n = 9) was assigned to level III evidence and four studies were classified as level IV. An overall improvement in clinical outcome was observed in 8/8 studies for the Japanese Orthopedic Association score (JOA) with a significant improvement for 5/8. The Nurick grade and cervical neck pain scores reported an overall improvement. Radiological, spinal stability was maintained. The most reported complication among all studies, with a cumulative rate of 13%, was the occurrence of Horner Syndrome (HS), which resolved in most studies between 3 and 6 months. There was no information given on the costs of OC, but two studies mentioned the operation time, which was 129 and 254 min respectively. 

Conclusion: OC has good results in terms of both clinical (JOA and Nurick) as radiological outcomes (spinal canal diameter and stability). However, the technique is technically demanding and therefore a more prolonged learning curve is required to prevent serious complications such as vertebral artery lesions or permanent HS. Although literature does not elaborate on cost effectiveness of OC, no additional instrumentation is necessary and therefore direct costs may be lower in comparison with other instrumented techniques.