Introduction: P-15 is a novel synthetic 15-amino acid polypeptide that mimics Type I collagen. i-FactorTM Peptide Enhanced Bone Graft (Cerapedics, Westminster CO) is a bone substitute composed of P-15 adsorbed onto anorganic bone mineral and suspended in an inert biocompatible hydrogel carrier. We report 24-month outcomes of patients who received i-Factor or local autograft during single-level ACDF for symptomatic cervical disc disease.
Methods: This pivotal prospective multi-center randomized FDA IDE single-blinded study from 2006-13 investigated safety and efficacy of i-Factor compared to autograft in 319 patients at 22 North American sites. Patients were evaluated preoperatively and postoperatively to 24 months. Outcome measures were: fusion; neurologic and NDI functional outcomes; VAS neck and arm/shoulder pain scores; SF-36v2 PCS and MCS; and Overall Success (fusion and neurologic success, NDI improvement >15, and absence of reoperations and device-related serious adverse events). Patients received either i-Factor (N=165) or local autograft (N=154) in a cortical ring allograft implanted into the target vertebral interspace prior to fixation device placement.
Results: The 12-month follow-up rate was 136/159 (85.53%) and 139/151 (92.05%) in i-Factor and autograft patients, respectively. The 24-month follow-up rate was 117/150 (78.00%) and 127/149 (85.23%), respectively. At 24 months, fusion was 97.30% and 94.44% in i-Factor and autograft patients, respectively; neurological success was 94.87% and 93.79%, respectively. NDI improved 28.30 and 26.95, respectively; VAS arm improved 5.43 and 4.97, respectively; VAS neck improved 4.78 and 4.41, respectively, SF36v2 PCS improved 10.23 and 10.18, respectively, and SF36v2 MCS improved 7.88 and 7.53, respectively. Overall Success was greater in i-Factor versus autograft patients (69.83% and 56.35%, respectively). Twelve (7.45%) i-Factor patients and 16 (10.53%) autograft patients had reoperations.
Conclusions: Use of i-Factor in ACDF is effective and safe, and results in similar—and on some metrics superior—outcomes compared to local autograft at 24 months following surgery.
Patient Care: The results of this analysis are an extension of the previous one-year results of the FDA IDE pivotal study on the effectiveness and safety of i-Factor in single-level ACDF for symptomatic cervical DDD. These current results show the continuous safety and effectiveness of i-Factor following surgical treatment at two years for symptomatic radiculopathy due to single-level cervical DDD. Specifically, fusion outcomes at two years improved compared to one year, and reached 97.3% in the i-Factor subjects. In addition, patient-reported symptoms and functional and health-related quality of life outcomes were sustained at two years. Use of i-Factor in ACDF is effective and safe, and results in similar--and in some metrics superior--outcomes compared to local autograft at two years following surgery.
Learning Objectives: By the conclusion of this session, participants should be able to describe the differences in outcomes at one and two years in patients who underwent ACDF with i-Factor Bone Graft versus autograft bone.