Cost analysis of anterior-posterior circumferential fusion and transforaminal lumbar interbody fusion

Background context: Although lumbar interbody fusion has long been a common procedure in the practice of spine surgery, focus on the technological development has produced the relatively new procedure of transforaminal lumbar interbody fusion (TLIF). This procedure is often available to surgeons as an alternative to anterior-posterior circumferential fusion (AP fusion), and both procedures have been demonstrated to be clinically equivalent at up to 5 years after surgery. In the context of clinical equipoise, it is unknown which procedure is more economically advantageous.

Purpose: To compare the hospital costs, charges, and payments received for surgical treatment with either AP fusion or TLIF. Future directions for health economic research with respect to spine surgery are also considered and discussed.

Study design: This is an institutional review board-approved, single-institution retrospective chart review and cost analysis.

Patient sample: Our study included patients undergoing either single-level AP fusion or single-level TLIF between 2006 and 2008. All patients were older than 18 years at the time of surgery; the decision of which procedure was performed was entirely at the discretion of the attending surgeon.

Outcome measures: Hospital costs, charges, and payments received for the treatment of each patient.

Methods: We performed a retrospective review of the medical and financial records of patients undergoing either AP fusion (n=179) or TLIF (n=90) on one operative level between 2006 and 2008. Medical records were evaluated for a history of spine surgery, operative time, estimated blood loss, and length of stay, whereas financial records were reviewed for the hospital costs, charges, and payments received as recorded by the hospital accounting data. Operative materials and service charges were also isolated and compared separately. This study was departmentally sponsored; there were no interest-associated biases for any of the authors involved.

Results: AP fusion patients had a longer operative time than TLIF patients, with a mean time of 246.5 versus 202.7 minutes (p<.01). Conversely, TLIF patients had a higher estimated blood loss during surgery (469.8 cm(3)) than AP fusion patients (311.2 cm(3)) (p<.01). The mean hospital cost for AP fusion was $25,165, whereas for TLIF was $23,390 (p=.04). The mean hospital charges and payments received for AP fusion were 1.07 (p=.05) and 1.35 (p<.01) times those received for TLIF, respectively. Therefore, mean hospital charges and payments received for TLIF were 0.93 and 0.76 times those received for AP fusion, respectively.

Conclusions: Our study demonstrates that a single-level AP fusion results in longer operative time, lower blood loss during surgery, higher hospital costs, higher hospital charges, and greater payments received than a single-level TLIF. Although the decision on how best to treat a patient lies solely at the judgment of the attending surgeon, this comparative cost information may be pertinent in cases of clinical equivalence. This study also calls attention to various shortcomings that are found in present spine surgery cost-effectiveness research, as there is an ongoing need for increased standards of quality in the area of health economics research.