Geographic variation in the surgical treatment of degenerative cervical disc disease: American Board of Orthopedic Surgery Quality Improvement Initiative; part II candidates

Abstract

Study design: Retrospective case series.

Objective: To examine and document the change in rates and the geographic variation in procedure type and utilization of plating by orthopedic surgeons for anterior cervical discectomy-fusion.

Summary of background: Age- and sex-adjusted rates of cervical spine surgery have not increased, but the rate of cervical spinal fusion has, accounting for 41% of all fusion procedures in 2004.

Methods: Records were selected from the American Board of Orthopedic Surgeons part II examination from 1999 to 2008. Current Procedural Terminology (CPT) and International Classification of Diseases, 9th Revision, Clinical Modification (ICDM-9-CM) codes were used to determine utilization of structural allograft, autograft/interbody devices, and anterior cervical plating over time and within geographic region. Main outcome measures were physician workforce, and rates and variation of procedure types.

Results: From 1999 to 2008, the number of self-declared orthopedic spine surgeon candidates increased 24%. Over this period, the annual number of discectomies with fusions for degenerative cervical disc disease increased by 67%, whereas the number of such operations per surgeon operating on at least 1 such case increased 48% (P = 0.018). Interbody device (0%-31%; P < 0.0001), anterior cervical plating (39%-79%; P < 0.0001), and allograft (14%-59%; P < 0.0001) use increased, whereas autograft use decreased (86%-10%; P < 0.0001). The Southwest and Southeast were more likely than the Midwest to use interbody devices (OR: 2.42 and 1.66, respectively). The Southwest and Northeast were more likely than the Midwest to use autograft (OR: 1.55 and 1.49). The Southwest, Northeast, and Southeast were less likely to use allograft than the Midwest (OR: 0.408, 0.742, and 0.770). The Northeast was less likely and the Southeast more likely than the Midwest to utilize anterior cervical plating (OR: 0.67 and 1.33). Surgical complications were more often associated with autograft compared with allograft (OR: 1.61).

Conclusion: From 1999 to 2008, the number of orthopedic surgeon candidates performing spine surgery has increased. These surgeons are performing more fusions and utilizing more structural allografts, interbody devices, and/or anterior cervical plates. Regional variations also remain in the types of constructs utilized.

Figure 1

ABOS Part II: Percentage Declared Subspecialty by Exam Year

Figure 2

Mean number of ACDF Cases per surgeon with at least one ACDF case.

Figure 3

Utilization of Autograft, Allograft and Interbody Device in Cervical Discectomy/Fusion Cases Exam Year

Figure 4

Cervical Discectomy/Fusion by Exam Year With and Without Anterior Cervical Plating