Natural Matrix Protein

Retrospective Data Collection:

Patient data was collected into a data sheet to collect specific elements that relate to safety and efficacy of the procedure utilizing this specific device system. The data elements of interest are:

Patient Summary data (where appropriate: average, sd, range):

Subject demographics Distribution of primary diagnoses

Surgical Information:

Length of constructs with note of non-contiguous constructs Levels treated Patient Assessments and Questionnaires prior to surgery Type and brand of interbody implant(s) used (if applicable) Induce and other bone graft materials used Adverse Events (defined in section 3.5) Description of adverse events Radiographic imaging at pre-operative, discharge, and follow-up time points of 6 months post-operatively (as available)

Prospective Data Collection:

Patients will be consented at their 12 month follow-up to participate in the clinical study. Clinical and radiographic data will be collected.

12 month radiographic data (SOC x-rays and CTs) Patient Assessment Questionnaires Surgeon Assessment of Patient Classification of any Secondary Surgical Procedures Adverse Events If patient has not achieved fusion, patient will be asked if they would be willing to follow-up at 24 months

Radiographic Assessment Imaging assessments will be performed by an independent imaging reviewer. The reviewer will be a musculoskeletal radiologist. The reviewer will be trained on the schedule of imaging assessments and classification systems for performing each assessment. The reviewer will not have access to clinical outcome data. Plain lateral radiographs at baseline, immediate postoperative, 6-month follow-up, 1-year follow-up, and 2-year follow-up (if available) will be utilized. All radiological measurements will be made using Sectra IDS7 (Sectra AB, Linköping, Sweden).

Fusion status on radiographs will be graded at each treated segment from an analysis of three components: bridging bone between the vertebral bodies, angular motion, and translational motion. Fusion Status measured on radiographs was derived from the qualitative assessment of bridging bone and the quantitative assessments of angular and translational Motion and in accordance to FDA guidance. The following grading system was implemented:

Not Fused: Absence of bridging bone from endplate to endplate in the intervertebral space, or angular motion \> 3 degrees, or translational motion \> 2 mm.

Fused: Presence of bridging bone from endplate to endplate in the intervertebral space, angular motion ≤ 3 degrees, and translational motion ≤ 2mm.

Retrospective-prospectively collected data will be recorded from subject electronic medical records

Study enrollment consists of 100 consecutive subjects who have consented to the study.

Statistical Analysis:

A performance goal methodology will be utilized to assess the primary outcome of fusion rate compared to literature controls. A literature review was conducted to find appropriate comparative studies that had similar criteria for the assessment of fusion for the performance model. The following studies are 1 level and 2 level lumbar interbody fusion studies that we used as the comparators:

Fairbank J. Re: Zigler J, Delamarter R, Spivak J, et al. Results of the prospective, randomized, multicenter Food and Drug Administration investigational device exemption study of the ProDisc-L total disc replacement versus circumferential fusion for the treatment of 1-level degenerative disc disease. Spine 2007;32:1155-62. Spine (Phila Pa 1976). 2007 Dec 1;32(25):2929-30; author reply 2930-1. doi: 10.1097/BRS.0b013e31815b84ca. PMID: 18246024.

Delamarter R, Zigler JE, Balderston RA, Cammisa FP, Goldstein JA, Spivak JM. Prospective, randomized, multicenter Food and Drug Administration investigational device exemption study of the ProDisc-L total disc replacement compared with circumferential arthrodesis for the treatment of two-level lumbar degenerative disc disease: results at twenty-four months.

From this modelling, our primary outcome performance goal would be an 96% fusion rate with a confidence interval of 93-99%.

Sample size calculation A total sample of 101 patients is needed for this study to estimate a fusion rate of 0.96 with two-sided 95% confidence interval of (0.93,0.99).

Statistical analysis plan Counts and percentages of fusion status will be summarized. 95% confidence interval for the proportion estimate will also be calculated. VAS satisfaction and ODI score will be summarized as mean and standard deviation, or median and IQR based on the distribution of them.