Anterior Cervical Discectomy and Fusion in Professional Athletes: Allograft Versus Autograft.

STUDY DESIGN: Level III-retrospective study. OBJECTIVE: The aim was to evaluate the effect method of bone grafting and contract status have on outcomes in a cohort of professional athletes treated with anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA: The choice of graft-type in ACDF is controversial, with current reports limited to smaller cohorts. MATERIALS AND METHODS: Retrospective analysis of 54 professional athletes treated with single level ACDF for cervical disc herniation, cervical fracture, or transient paraparetic event. RESULTS: A case series of professional athletes with ACDF by the senior surgeon were evaluated, 39 with structural iliac crest autograft and 15 with allograft. All autograft patients had confirmed bony fusion, whereas 13/15 allograft patients had a confirmed bony fusion. Each of these players (2/15, 13.3%) was delayed for clearance for return to play by 1 season. In total, 43/50 players (88%) returned to professional play; 25/27 (92.6%) of them "self-employed" and 18/23 (78.2%) "league-contracted." CONCLUSIONS: Surgical treatment of cervical pathology in the professional athlete with structural iliac crest autograft results in high union and return to play rates. Use of allograft resulted in a 13.3% increased rate of missing an additional season. Self-employed athletes returned to play 1 season earlier than league-contracted athletes on average.

A biomechanical evaluation of a spacer with integrated plate for treating adjacent-level disease in the subaxial cervical spine.

BACKGROUND CONTEXT: Adjacent level degeneration (ALD) has been reported as one of the long-term consequences of anterior discectomy and fusion despite its clinical success in treating cervical pathologies. Traditionally, ALD is treated by replacing the previously implanted plate with a longer plate, which can lead to postoperative complications. The biomechanics of SIP in the adjacent level has not been investigated. PURPOSE: To evaluate the multidirectional stability of a spacer with integrated plate (SIP) in comparison to a traditional spacer and plate (TSP). STUDY DESIGN: To evaluate the biomechanical stability of a spacer with integrated plate adjacent to a traditional spacer and plate construct in a human cervical cadaveric model. METHODS: Eight fresh human cervical (C2-C7) cadaver spines were mounted on a six degree-of-freedom spine simulator. The sequence of test constructs was: 1) Intact; 2) TSP (C4-C6) with SIP (C3-C4); and 3) TSP (C3-C6). An unconstrained moment of ±1.5 Nm was used in flexion-extension, lateral bending, and axial rotation. Range of motion (ROM) was measured by a digital motion analysis system. Statistical analysis was performed using ANOVA repeated measures. RESULTS: All instrumented constructs significantly reduced ROM compared to the intact condition. No statistically significant difference was observed between the two-level TSP with an adjacent SIP construct and three-level TSP construct in all loading modes. CONCLUSION: The biomechanical study shows that adding a spacer with integrated plate adjacent to a two-level anterior plate demonstrates equivalent stability to a three-level anterior plate. The spacer with integrated plate, which preserves the originally plated fusion levels, may overcome the complications associated with the traditional technique of replacing the original plate with a longer plate. However, prospective clinical studies are required to address the clinical benefits and challenges, if any.

The biomechanical stability of a novel spacer with integrated plate in contiguous two-level and three-level ACDF models: an in vitro cadaveric study.

BACKGROUND CONTEXT: Anterior cervical plating increases stability and hence improves fusion rates to treat cervical spine pathologies, which are often symptomatic at multiple levels. However, plating is not without complications, such as dysphagia, injury to neural elements, and plate breakage. The biomechanics of a spacer with integrated plate system combined with posterior instrumentation (PI), in two-level and three-level surgical models, has not yet been investigated. PURPOSE: The purpose of the study was to biomechanically evaluate the multidirectional rigidity of spacer with integrated plate (SIP) at multiple levels as comparable to traditional spacers and plating. STUDY DESIGN: An in vitro cervical cadaveric model. METHODS: Eight fresh human cervical (C2-C7) cadaver spines were tested under pure moments of ±1.5 Nm on spine simulator test frame. Each spine was tested in intact condition, with only anterior fixation and with both anterior and PI. Range of motion (ROM) was measured using Optotrak Certus (NDI, Inc., Waterloo, Ontario, Canada) motion analysis system in flexion-extension (FE), lateral bending (LB), and axial rotation (AR) at the instrumented levels (C3-C6). Repeated-measures analysis of variance was used for statistical analysis. RESULTS: All the surgical constructs showed significant reduction in motion compared with intact condition. In two-level fusion, SIP (C4-C6) construct significantly reduced ROM by 66.5%, 65.4%, and 60.3% when compared with intact in FE, LB, and AR, respectively. In three-level fusion, SIP (C3-C6) construct significantly reduced ROM by 65.8%, 66%, and 49.6% when compared with intact in FE, LB, and AR, respectively. Posterior instrumentation showed significant stability only in three-level fusion when compared with their respective anterior constructs. In both two-level and three-level fusion, SIP showed comparable stability to traditional spacer and plate constructs in all loading modes. CONCLUSIONS: The anatomically profiled spacer with integrated plate allows treatment of cervical disorders with fewer steps and less impact to cervical structures. In this biomechanical study, spacer with integrated plate construct showed comparable stability to traditional spacer and plate for two-level and three-level fusion. Posterior instrumentation showed significant effect only in three-level fusion. Clinical data are required for further validation of using spacer with integrated plate at multiple levels.