What Is the Fate of Pseudarthrosis Detected 1 Year After Anterior Cervical Discectomy and Fusion?
METHODS
Retrospective comparative study.


OBJECTIVE
To investigate the consequences and appropriate management of pseudarthrosis after anterior cervical discectomy and fusion (ACDF).


BACKGROUND
Pseudarthrosis is a frequent complication of ACDF and causes unsatisfactory results. Little is known about long-term prognosis of detecting pseudarthrosis 1 year after ACDF.


METHODS
Eighty-nine patients with a minimum 2-year follow-up were included. ACDF surgery using allograft and plating was performed: single-level in 51 patients, two-level in 26 patients, and three-level in 12 patients. Presence of pseudarthrosis was evaluated 1 year postoperatively and then the nonunion segments were re-evaluated 2 years postoperatively. Demographic data were assessed to identify the risk factors associated with pseudarthrosis. A visual analogue scale for neck/arm pain and the Neck Disability Index were analyzed preoperatively and at 1 and 2 years postoperatively.


RESULTS
Pseudarthrosis was detected in 29 patients (32.6%) 1 year postoperatively: 15of 51 patients after single-level surgery, 9 of 26 patients after two-level surgery, and 5 of 12 patients after three-level surgery. Only eight patients showed persistent nonunion at 2 years: 3 of 15 patients after single-level surgery, 3 of 9 after two-level surgery, and 2 of 5 after three-level surgery. The remaining 21 patients (72.4%) achieved bony fusion 2 years postoperatively without any intervention. Patients who underwent two-level or three-level ACDF had a significantly higher pseudarthrosis rate than those who underwent single-level ACDF, with odds ratios of 1.844 and 3.147, respectively. The improvements in visual analogue scale for neck pain and Neck Disability Index scores in the persistent nonunion group were significantly lower than those in the final union group at 2 years.


CONCLUSIONS
Patients with pseudarthrosis detected 1 year postoperatively may be observed without any intervention because approximately 70% of them will eventually fuse by the 2-year point. Early revision could, however, be considered if the pseudarthrosis is associated with considerable neck pain after multilevel ACDF.


METHODS
3.
Department of Orthopedic Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Dong-Ho
DH
Lee
Department of Orthopedic Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Jae Hwan
JH
Cho
Department of Orthopedic Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Chang Ju
CJ
Hwang
Department of Orthopedic Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Choon Sung
CS
Lee
Department of Orthopedic Surgery, Icahn School of Medicine at Mount Sinai, New York, NY.
Samuel K
SK
Cho
Department of Orthopedic Surgery, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Korea.
Chunghwan
C
Kim
Department of Orthopedic Surgery, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Korea.
Jung-Ki
JK
Ha
D000368:Aged; D002574:Cervical Vertebrae / Q000601:surgery*; D017586:Diskectomy / Q000009:adverse effects* / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019547:Neck Pain / Q000209:etiology*; D011183:Postoperative Complications / Q000209:etiology; D011184:Postoperative Period; D011379:Prognosis; D011542:Pseudarthrosis / Q000209:etiology*; D012189:Retrospective Studies; D012307:Risk Factors; D013123:Spinal Fusion / Q000009:adverse effects* / Q000379:methods; D016896:Treatment Outcome