Perioperative complications with rhBMP-2 in transforaminal lumbar interbody fusion.

Bone morphogenetic protein (BMP) is commonly used as an ICBG substitute for transforaminal lumbar interbody spine fusion (TLIF). However, multiple recent reports have raised concerns regarding a substantial incidence of perioperative radiculopathy. Also, given the serious complications reported with anterior cervical BMP use, risks related to swelling and edema with TLIF need to be clarified. As TLIF related complications with rhBMP-2 have generally been reported in small series or isolated cases, without a clear denominator, actual complication rates are largely unknown. The purpose this study is to characterize perioperative complications and complication rates in a large consecutive series of TLIF procedures with rhBMP-2. We reviewed inpatient and outpatient medical records for a consecutive series of 204 patients [113 females, 91 males, mean age 49.3 (22-79) years] who underwent TLIF using rhBMP-2 between 2003 and 2007. Complications observed within a 3-month perioperative interval were categorized as to etiology and severity. Wound problems were delineated as wound infection, hematoma/seroma or persistent drainage/superficial dehiscence. Neurologic deficits and radiculopathies were analyzed to determine the presence of a clear etiology (screw misplacement) and identify any potential relationship to rhBMP-2 usage. Complications were observed in 47 of 204 patients (21.6%) during the 3-month perioperative period. Major complications occurred in 13 patients (6.4%) and minor complications in 34 patients (16.7%). New or more severe postoperative neurologic complaints were noted in 13 patients (6.4%), 6 of whom required additional surgery. These cases included one malpositioned pedicle screw and one epidural hematoma. In four patients (2.0%), localized seroma/hematoma in the area of the foramen caused neural compression, and required revision. In one additional patient, vertebral osteolysis caused foraminal narrowing and radiculopathy, but resolved without further surgery. Persistent radiculopathy without clear etiology on imaging studies was seen in six patients. Wound related problems were seen in six patients (2.9%), distributed as wound infection (3), hematoma/seroma (1) and persistent drainage/dehiscence (2). Overall, this study demonstrates a modest complication rate for TLIF using rhBMP-2. While perioperative complications which appeared specific to BMP usage were noted, they occurred infrequently. It will be necessary to weigh this incidence of complications against the complication rate associated with ICBG harvest and any differential benefit in obtaining a solid arthrodesis.

Cost-effectiveness of minimally invasive midline lumbar interbody fusion versus traditional open transforaminal lumbar interbody fusion.

OBJECTIVE: The midline transforaminal lumbar interbody fusion (MIDLIF) using cortical screw fixation is a novel, minimally invasive procedure that may offer enhanced recovery over traditional open transforaminal lumbar interbody fusion (TLIF). Little information is available regarding the comparative cost-effectiveness of the MIDLIF over conventional TLIF. The purpose of this study was to compare cost-effectiveness of minimally invasive MIDLIF with open TLIF. METHODS: From a prospective, multisurgeon, surgical database, a consecutive series of patients undergoing 1- or 2-level MIDLIF for degenerative lumbar conditions was identified and propensity matched to patients undergoing TLIF based on age, sex, smoking status, BMI, diagnosis, American Society of Anesthesiologists Physical Status Classification System (ASA) class, and levels fused. Direct costs at 1 year were collected, including costs associated with the index surgical visit as well as costs associated with readmission. Improvement in health-related quality of life was measured using EQ-5D and SF-6D. RESULTS: Of 214 and 181 patients undergoing MIDLIF and TLIF, respectively, 33 cases in each cohort were successfully propensity matched. Consistent with propensity matching, there was no difference in age, sex, BMI, diagnosis, ASA class, smoking status, or levels fused. Spondylolisthesis was the most common indication for surgery in both cohorts. Variable direct costs at 1 year were $2493 lower in the MIDLIF group than in the open TLIF group (mean $15,867 vs $17,612, p = 0.073). There was no difference in implant (p = 0.193) or biologics (p = 0.145) cost, but blood utilization (p = 0.015), operating room supplies (p < 0.001), hospital room and board (p < 0.001), pharmacy (p = 0.010), laboratory (p = 0.004), and physical therapy (p = 0.009) costs were all significantly lower in the MIDLIF group. Additionally, the mean length of stay was decreased for MIDLIF as well (3.21 vs 4.02 days, p = 0.05). The EQ-5D gain at 1 year was 0.156 for MIDLIF and 0.141 for open TLIF (p = 0.821). The SF-6D gain at 1 year was 0.071 for MIDLIF and 0.057 for open TLIF (p = 0.551). CONCLUSIONS: Compared with patients undergoing traditional open TLIF, those undergoing MIDLIF have similar 1-year gains in health-related quality of life, with total direct costs that are $2493 lower. Although the findings were not statistically significant, minimally invasive MIDLIF showed improved cost-effectiveness at 1 year compared with open TLIF.