Jennifer Howard

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.

Complications with recombinant human bone morphogenic protein-2 in posterolateral spine fusion: a consecutive series of 1037 cases.

Study Design. Retrospective case series. Objective. The purpose of this study was to report on a large consecutive series of posterolateral fusion cases using rhBMP-2/ACS. Summary of Background Data. Despite evidence that rhBMP-2/ACS is effective as an iliac crest graft substitute in posterolateral fusion, concerns remain regarding potential risk for BMP use in clinical practice. These concerns have been fueled by the serious complications reported with BMP in anterior cervical spine fusion. While none of the literature on posterolateral fusion with rhBMP-2/ACS has suggested an increased complication rate versus iliac crest bone graft, this issue has not been specifically studied. Methods. We reviewed medical records for a consecutive series of 1037 patients who underwent posterolateral spine fusion using rhBMP-2 between 2003 and 2006. Medical complications were attributed to the surgical procedure if they occurred within the 3-month perioperative period, whereas complications potentially related to BMP were included regardless of time frame. Results. Medical and surgical complications were observed in 190 of 1037 patients (18.3%) with 81 major complications (7.8%) and 110 minor complications (10.2%). Neurologic complications were related to screw malposition in 6 patients and epidural hematoma in 3 patients. New or more severe postoperative radicular symptoms were noted in 7 patients (0.7%). Psoas hema- toma was identified by CT scan in 8 patients (0.8%). Complications directly related to rhBMP-2 were observed in at least 1 patient (0.1%) and in a worst case analysis, in as many as 6 patients (0.6%). Conclusion. This study in 1037 patients confirms the relative safety of rhBMP-2/ACS for posterolateral spine fusion. There were extremely few complications directly attributed to rhBMP-2/ACS, and the overall complication rates were consistent with established norms. The stark contrast between this experience and the markedly elevated complication rate reported with anterior cervical BMP usage emphasizes the need to evaluate risks and benefits of bioactive technologies in a site-specific and procedure-specific manner.

Posterior iliac crest pain after posterolateral fusion with or without iliac crest graft harvest

BACKGROUND CONTEXT Considerable debate exists regarding the incidence of persistent pain from the iliac crest bone graft (ICBG) harvest site. Different study designs have led to a variety of reported rates. PURPOSE The purpose of this study was to determine the incidence and severity of bone graft site pain after iliac crest harvest. STUDY DESIGN Cross-sectional. PATIENT SAMPLE One hundred and twelve patients, who had a posterior lumbar fusion, seen at a tertiary spine center for a routine postoperative visit. OUTCOME MEASURES Numeric rating scales (0-10) for pain over lower back, right, and left posterior iliac crests. METHODS An independent investigator, not directly involved in the care of the patient and unaware of the type of bone graft used in the fusion, examined the patient for tenderness over the surgical site as well as the left and right posterior iliac crest. After the examination, data on the source of grafting material, complications during harvest, and backfilling of the graft site defect were collected from the medical records. The patients were then classified as to whether ICBG was harvested or not. Chi-square test was used to determine any difference in the proportion of iliac crest pain between the bone graft group and no bone graft group. Correlations between body mass index (BMI), time since surgery, and the incidence and severity of bone graft site pain were also determined. RESULTS There were 72 women and 40 men with a mean age of 56.6 years (range, 16-84). Mean follow-up was 41 months (range, 6-211 months) with a median of 25 months. Iliac crest bone graft was harvested in 53 (47.3%) patients through the midline incision used for lumbar fusion. In 59 patients (52.7%), recombinant human bone morphogenetic protein-2 was used with no graft harvest. There was no statistically significant difference in the proportion of patients complaining of tenderness over both or either iliac crest between the two groups. Only 10 patients had pain over the same crest from which the graft was harvested. No correlations between number of levels fused, levels fused, BMI, length of follow-up, and the incidence and severity of bone graft site pain were seen. CONCLUSIONS The results of this study highlight the difficulty in differentiating pain originating from the graft site versus residual low back pain. The incidence of pain over the iliac crest was similar in patients in which iliac crest was harvested and those in which no graft was harvested.

Complications and Concerns With Osteobiologics for Spine Fusion in Clinical Practice

Study Design. Literature-based topic review. Objective. To review the complications and the concerns that may be associated with all of the commonly used osteobiologic options for spine fusion. Summary of Background Data. Obtaining a solid arthrodesis is an important objective in many lumbar surgical procedures, and a wide array of bone graft materials may be used in an attempt to achieve this goal. Iliac crest bone graft, as well as all of the available osteobiologic alternatives, carries potential risks and concerns for both patient and surgeon. Methods. Review of literature and expert opinion. Conclusion. Some of the potential complications associated with osteobiologic materials used in spinal fusion are well understood and clearly documented whereas others require further study and clarification. In any given clinical situation, the patient and surgeon need to balance the benefits and performance characteristics of the graft material with the risk profile to optimize clinical management.

Health-related quality of life improvements in patients undergoing lumbar spinal fusion as a revision surgery.

Study Design. Retrospective cohort analysis. Objective. To investigate health-related quality of life improvements in patients undergoing lumbar fusion to revise a previous lumbar spine surgery. Summary of Background Data. Spinal fusion is often used as a surgical intervention in patients who have previously undergone lumbar surgery. Prior studies suggest results that are inferiorto primary fusions. However, most of these studies are based on subjective surgeon evaluations, lack patient-reported outcomes, and include various diagnoses such as prior discectomy, adjacent level degeneration, and nonunion. Methods. From a single-center database, we identified 171 patients who underwent lumbar fusion to revise a previous lumbar spine surgery. All had prospectively collected outcome measures at a minimum 2-year follow-up. The study group included 91 patients who had previous discectomy or laminectomy, 42 patients undergoing revision for adjacent segment degeneration (ASD) and 38 patients undergoing revision for nonunion. All patients completed the Oswestry Disability Index (ODI), MOS Short Form 36 (SF-36), and back and leg pain numerical rating scores before surgery and at 1 and 2 years after surgery. We compared mean changes in outcome measures and percentage of patients reaching the minimum clinically important difference (MCID) threshold in the 3 groups. Logistic regression analysis was performed to identify preoperative factors which could predict significant improvement. Results. Statistically significant improvements were noted in back pain, leg pain, and ODI in all 3 groups. Postdecompression and ASD patients demonstrated significant improvements in SF-36 PCS at 2 years, while nonunion patients did not. A total of 49% of postdecompression patients, 38% of ASD patients, and 29% of nonunion patients reached the MCID for ODI. About 46% of postdecompression patients, 40% of ASD patients, and 24% of nonunion patients reached the MCID for SF-36 PCS. Significant improvement from index surgery was the only factor which able to predict reaching the MCID for ODI, while workers compensation and narcotic use predicted failure to reach the MCID for SF-36 PCS. Conclusion. The current study demonstrates that patients undergoing lumbar fusion as a revision of a prior lumbar surgery can expect only modest improvements in health-related quality of life. Postdecompression patients achieved moderate improvements in clinical outcome measures, whereas ASD and nonunion patients showed only modest improvements. Further investigation is needed to identify preoperative predictors that will assist the selection of patients who will benefit from revision lumbar fusion.

Does Fusion Status Correlate with Patient Outcomes in Lumbar Spinal Fusion

Study Design. Prospective cohort. Objectives. The purpose of this study is to examine the relationship between radiographic fusion and patient-reported health-related quality of life (HRQOL) measures in patients undergoing instrumented posterolateral lumbar fusion. Summary of Background Data. Previous studies have shown that a solid fusion does not always produce clinical success. However, these studies did not use validated patient-reported HRQOL measures. Methods. One hundred ninety-three patients who underwent instrumented posterolateral fusion with complete preoperative and 2-year HRQOL measures and a fine-cut computed tomographic (CT) scan with reconstructions done at 2 years after surgery specifically done to assess fusion status were identified. HRQOL measures included the Oswestry Disability Index (ODI), the Short Form-36 and back and leg pain numerical rating scales. The percentage of patients reaching the minimum clinically important difference and substantial clinical benefit for ODI and Short Form-36 were also calculated. CT scans were graded as fused or not by three independent reviewers. Comparisons were made in outcomes measures between the patients with solid fusions and those judged not to have a solid radiographic fusion. Results. There were 124 women and 69 men with an average age of 63 years. Patients judged to have a solid fusion demonstrated a better ODI score at 2 years than those who were not solidly fused (P = 0.023). There was a trend toward greater improvement in mean ODI score in those with a solid fusion (P = 0.074). A statistically greater number of patients who had a solid fusion (111 of 171, 65%) achieved the minimum clinically important difference for ODI than those who did not achieve a solid fusion (7 of 22, 32%) (P = 0.004). Conclusion. A greater proportion of patients achieved clinically relevant improvements in low back specific quality-of-life measures when they had achieved a solid fusion than patients who did not have a solid fusion. Although radiographic fusion may not be the true measure of clinical success, this study suggests that solid arthrodesis contributes to clinical outcome and is an important goal of fusion surgery.

Lumbar lordosis restoration following single-level instrumented fusion comparing 4 commonly used techniques.

A major sequelae of lumbar fusion is acceleration of adjacent-level degeneration due to decreased lumbar lordosis. We evaluated the effectiveness of 4 common fusion techniques in restoring lordosis: instrumented posterolateral fusion, translumbar interbody fusion, anteroposterior fusion with posterior instrumentation, and anterior interbody fusion with lordotic threaded (LT) cages (Medtronic Sofamor Danek, Memphis, Tennessee). Radiographs were measured preoperatively, immediately postoperatively, and a minimum of 6 months postoperatively. Parameters measured included anterior and posterior disk space height, lumbar lordosis from L3 to S1, and surgical level lordosis.No significant difference in demographics existed among the 4 groups. All preoperative parameters were similar among the 4 groups. Lumbar lordosis at final follow-up showed no difference between the anteroposterior fusion with posterior instrumentation, translumbar interbody fusion, and LT cage groups, although the posterolateral fusion group showed a significant loss of lordosis (-10°) (P<.001). Immediately postoperatively and at follow-up, the LT cage group had a significantly greater amount of lordosis and showed maintenance of anterior and posterior disk space height postoperatively compared with the other groups. Instrumented posterolateral fusion produces a greater loss of lordosis compared with anteroposterior fusion with posterior instrumentation, translumbar interbody fusion, and LT cages. Maintenance of lordosis and anterior and posterior disk space height is significantly better with anterior interbody fusion with LT cages.