Session VI - Pediatrics / Spine

Fri., 10/11/13 Pediatrics/Spine, PAPER #74, 4:36 pm OTA 2013

Factors Associated With Nonunion in 97 Consecutive Type 2 and Type 3 Odontoid Fractures in Elderly Patients

Michael Merrick, MD1; Debra L. Sietsema, PhD2,3; Casey Smith, MD1; Tan Chen, BS3;
Scott S. Russo, MD2,3; Clifford B. Jones, MD2,3; James R. Stubbart, MD2,3;
1Grand Rapids Medical Education Partners, Grand Rapids, Michigan, USA;
2Orthopaedic Associates of Michigan, Grand Rapids, Michigan, USA;
3Michigan State University, Grand Rapids, Michigan, USA

Purpose: Odontoid fractures are the most common cervical spine injury in older adults and have high rates of morbidity and mortality. The purpose of this study was to determine factors that were associated with nonunion in odontoid fractures.

Methods: Between 2002 and 2011, 97 consecutive patients, age 65 years and over, with type 2 and type 3 odontoid fractures were treated at a single Level I trauma center, were followed in a single private practice, and retrospectively evaluated. Radiographs were reviewed and fusion was determined by flexion/extension x-rays, CT scan, or both. 23 mortalities occurred prior to 6 months postinjury, and they were excluded from the fusion analysis. One patient was lost to follow-up prior to evaluation for fusion.

Results: There were 31 males (42%) and 42 females with a mean age of 80 (range, 65-93) who were evaluated for fusion of their type 2 (55, 75%) or 3 (18, 25%) odontoid fracture. Mean body mass index (BMI) was 26.9 (range, 17.1-37.5). The overall fusion rate in the 73 patients who were living at the time of fusion analysis was 71.2%. Patients treated with nonsurgical management had a lower rate of fusion (31 of 51, 60.8%) compared to patients who were treated with surgery (21 of 22, 95.5%) (χ2 = 0.003). Males had a lower fusion rate (18 of 31, 58.1%) than females (34 of 42, 81%) (χ2 = 0.033). Fusion was affected by comorbidities. Those with fusion had a lower Charlson score (1.65) than those who did not fuse (2.67) (t = –2.045, sig = 0.045). Additionally, congestive heart failure (CHF) was a significant independent medical comorbidity associated with nonunion. Out of the 21 patients who were found to have nonunion, 8 (38.1%) had a diagnosis of CHF at the time of admission. 52 patients were found to have a fusion of their odontoid fracture, and only 4 of those patients had CHF (7.7%) (χ2 = 0.002). Factors without statistical significance included age, BMI, tobacco use, sagittal fracture displacement, direction of displacement, type of odontoid fracture, odontoid angle, time to surgery, method of nonsurgical management, time to discontinuation of rigid collar, and surgical technique.

Conclusion: Factors associated with nonunion in older patients with odontoid fractures include: nonsurgical treatment, males, higher numbers of medical comorbidities, and congestive heart failure.

Alphabetical Disclosure Listing

• The FDA has not cleared this drug and/or medical device for the use described in this presentation   (i.e., the drug or medical device is being discussed for an “off label” use).  ◆FDA information not available at time of printing. Δ OTA Grant.