A nationwide registry study of surgical and patient-reported outcomes following anterior cervical discectomy and fusion: Part 2 - cage with versus without local bone graft.

Abstract

Local bone grafts are commonly used as filling material in cages during anterior cervical discectomy and fusion (ACDF). Alternatively, cages without filling materials can be used. The literature comparing these approaches is limited, and their respective effects on patient-reported outcomes (PROM) have been scarcely studied. This study was conducted to compare surgical outcomes and PROMs between local bone graft-packed cages and empty cages in ACDF surgery. This observational study utilized data from the Swedish nationwide registry, Swespine. All adults who underwent ACDF between 2006 and 2020 were considered for inclusion. Exclusion criteria included missing baseline or outcome data. Patients were grouped according to cage type (with vs. without local bone graft). The primary outcome was achievement of a minimal clinically important difference (MCID) for arm pain in radiculopathy patients and for the European Myelopathy Score (EMS) in myelopathy patients. Secondary outcomes included complications, reoperations, and length of hospital stay. Outcomes were analyzed using multivariable generalized linear models adjusted for clinically relevant covariates. A total of 6,571 patients were included, with 2,963 patients (45%) receiving cages with local bone graft and 3,608 patients (55%) receiving cages without local bone graft during ACDF. Achievement of MCID for arm pain (radiculopathy) (OR 0.90, 95% CI 0.79-1.04, p = 0.15) and for EMS (myelopathy) (OR 1.15, 95% CI 0.67-2.03, p = 0.62) did not differ between groups. Local bone graft use was associated with higher odds of reoperation (OR 1.69, 95% CI 1.20-2.39, p = 0.003) and a longer hospital stay (β = 0.31 days, 95% CI 0.21-0.40, p < 0.001). This nationwide registry-based study demonstrates that ACDF performed with or without local bone graft is equally safe and effective, with comparable rates of PROM MCID achievement and similar adverse event profiles, although use of local bone graft was associated with higher reoperations and longer hospital stays.