Comparative Study for Cervical Spinal Fusion Using Cervical Cages with and Without Bone Granules

Abstract Background: Cervical spinal fusion is a surgical procedure that joins selected bones in the cervical spine.
The anterior approach to the cervical spine was developed for treatment of cervical disc, it involves removing the symp-tomatic disc from an anterior approach without placement of a bone graft. Early studies demonstrated fusion rates with Anterior Cervical Discectomy (ACD) were similar to those of procedures of anterior cervical discectomy and fusion (ACDF) using bone graft. The anterior cervical discectomy and fusion with instru-mentation (ACDFI) technique involves the additional stabili-zation of the cervical spine & graft with instrumentation.
Cages were introduced to be used with either autologous or synthetic bone grafts, promoting stability and encouraging fusion. Comparing to graft alternatives, cage interbody implants have better biomechanical properties, designed to maximise biocompatibility and reduced graft dislodgements, increased fusion rates, and decreased foraminal stenosis. However, placement of implants introduces hardware-related complica-tions.
Aim of the Study: This prospective study aims to compare the results of ACDFI using cages with & without synthetic bone granules evaluating the outcomes, fusion and associated morbidities.
Patients and Methods: Prospective study of 42 patients operated upon between 2012 and 2014 in Cairo University Hospitals & Beni Sueif University Hospital with ACDFI using cervical cages. Patients were divided into two groups: - Group (A) 22 patients operated by ACDFI with placement of cages only - Group (B) 20 patients operated by ACDFI with placement of cages and synthetic bone granules. Both groups underwent postoperative clinical follow-up for an average of 12 months, and results were evaluated according to radiographic evidence of fusion and Fisher exact probability test was used to compare fusion of both groups. We made considerations for patient's age, sex, osteoporosis, and smoking habits. We recorded fusion rates, cervical alignment, postoperative complications & patient satisfaction using Visual Analogue Score (VAS). Results: 42 patients were included in the study. The mean age was 46, 18 of them were females and 24 were males. 29 patients had single level discs and 13 patients had two levels.
One year follow-up fusion rates that were achieved in group (A) were 81.8% while group (B) reached 95%. One year follow up on achievement of alignment of cervical spine was 90.9% of patient's in group (A) and in group (B) was 95% of cases.
There were no problems regarding surgical technique or dislodgment in both techniques. Only in one patient in group
(A)CSF leak developed and resolved. One patient in group
(B)developed a keloid at incision site.
Conclusion: Fusion rate is one of several factors that guide surgical decision making for cases requiring ACDFI. Fusion rate is significantly higher in group (B) using cages filled with synthetic bone granules than in group (A) with cages only. Age, sex, osteoporosis and smoking status have not given significantly different results between both groups studied.