Morphometric Comparison of Interbody Fusion with Cage and Autograft at L4-L5 Levels versus Autograft Alone for Fusion

Abstract

Objective:Lumbar interbody fusion (LIF) entails the placement of a bone graft within the intervertebral space, with or without the use of a cage, subsequent to discectomy. While numerous studies have explored caged LIF methods within the literature, limited attention has been given to direct comparisons between caged and cageless LIF techniques. This study aims to scrutinize the delayed outcomes of interbody fusion involving peek-caged and cageless laminar autografts. The investigation was specifically carried out at the L4-5 level.Method:This retrospective comparative study was conducted on patients who underwent surgical procedures at our institution’s neurosurgery clinic between 2011 and 2018, with the sanction of the ethics committee from the same institution. The study group (Group 1, n=27) comprised patients who underwent L4-5 single-level lumbar instrumentation and transforaminal LIF using a banana cage alongside autograft for the purpose of fusion. The control group (Group 2, n=31) consisted solely of cases that underwent posterior LIF operations with the utilization of autografts. Corticocancellous bone fragments sourced from posterior structures during decompression were utilized as autografts. The study parameters encompassed fusion rates, segmental and lumbar lordosis angles, disc height, ipsilateral and contralateral foramen heights, as well as slip distance.Results:Within our study, the late-stage fusion rates were determined to be 96.3% in the caged group and 96.7% in the cageless autograft group. No alterations were identified in segmental and lumbar lordosis angles across both groups. Notably, the caged group exhibited a propensity for late-stage cage embedding, while graft migration was the most prevalent complication within the autograft group.Conclusion:Both caged and cageless LIF methodologies are associated with elevated fusion rates. The autograft group demonstrates certain limited advantages in terms of fusion, whereas the caged group exhibits some benefits primarily related to alignment. The implementation of cageless autograft LIF, marked by its straightforwardness, simplicity, and cost-effectiveness, appears to be an underappreciated surgical technique within the current context.

Keywords

• autograft
• cage
• interbody fusion
• peek cage