Is Intraoperative Prone Radiograph Helpful to Predict Radiographic Result for Lenke Type 1 and 3 Patients Treated by Selective Fusion?

Proceedings of the NASS 27th Annual Meeting / The Spine Journal 12 (2012) 99S–165S P80. Retrograde Ejaculation Following Anterior Lumbar Spine Surgery Emily M. Lindley, PhD1, Zachary McBeth, BS1, Sarah E. Henry, MPH1, Evalina L. Burger, MD2, Christopher M. Cain, MD, FRACS3, Vikas V. Patel, MD4; 1University of Colorado Denver, Aurora, CO, US; 2 UCDenver Department of Orthopaedics, Aurora, CO, US; 3Aurora, CO, US; 4Denver, CO, US BACKGROUND CONTEXT: Anterior lumbar interbody fusion (ALIF) has become a popular choice for treating a number of pathologies, largely because it preserves the posterior paravertebral muscles and ligaments. Despite these advantages, the anterior approach is also associated with various complications, one of which is retrograde ejaculation (RE). A recent study has questioned whether the risk of RE is increased by the use of BMP in ALIF procedures, rather than by the approach alone. PURPOSE: To compare the incidence of RE after anterior lumbar spine surgery with artificial disc replacement (ADR) versus fusion with the use of recombinant human bone morphogenetic protein-2 (BMP). Given that BMP is used as a standard of care in ALIF procedures at our institution, ADR was chosen as a control group because it involves the same anterior approach but does not include the use of BMP. STUDY DESIGN/SETTING: Retrospective cohort study. PATIENT SAMPLE: Male patients who received ALIF using BMP or ADR on at least the L5-S1 level. OUTCOME MEASURES: Occurrence of RE. METHODS: We conducted a retrospective review of all male patients who received ALIF using BMP or ADR on at least the L5-S1 level between 2004 and 2011. Medical records were evaluated for the occurrence of RE and patients were contacted via phone to obtain current information. The incidence of RE was then compared between the two anterior lumbar surgery procedures. RESULTS: Of the 95 cases of anterior surgery including L5-S1, 54 patients underwent ALIF with BMP (56.8%) and 41 patients were treated with ADR (43.2%). Postoperative RE occurred in 4 of the 54 ALIF patients (7.4%) and in 4 of the 41 ADR patients (9.8%). The incidence of RE was not significantly different between groups (p 5 0.7226). At latest follow up, 1 ALIF and 1 ADR patient reported resolution of the RE. CONCLUSIONS: In the present study, we investigated whether anterior lumbar spine surgery using BMP is associated with a higher incidence of RE than anterior approaches that do not involve the use of BMP, such as ADR. We found that RE occurred at a similar rate in patients treated with ADR and ALIF with BMP. The overall rate of RE following retroperitoneal anterior lumbar surgery was higher than expected, which underscores the importance of counseling patients about this risk and specifically questioning patients about the symptoms of RE at postoperative visits. FDA DEVICE/DRUG STATUS: rhBMP-2 (Approved for this indication), ProDisc-L (Approved for this indication), Activ-L (Approved for this indication). http://dx.doi.org/10.1016/j.spinee.2012.08.354 P81. Is Intraoperative Prone Radiograph Helpful to Predict Radiographic Result for Lenke Type 1 and 3 Patients Treated by Selective Fusion? Sinan Kahraman, MD1, Meric Enercan, MD2, Cagatay Ozturk, MD3, Alaaddin Kochi, MD1, Mehmet B. Balioglu, MD4, Mercan Sarier3, Azmi Hamzaoglu, MD5, Ahmet Alanay, MD6; 1Istanbul Spine Center, Istanbul, Turkey; 2Florence Nightingale Hospital Istanbul Spine Center, Istanbul, Turkey; 3Istanbul Spine Center, Florence Nightingale Hospital, Istanbul, Turkey; 4Istanbul, Turkey; 5Turkey; 6Florence Nightingale Hospital, Istanbul, Turkey BACKGROUND CONTEXT: It is often difficult to predict postop lumbar curve (L) magnitude and balance parameters while performing intraoperative correction during selective thoracic fusion.

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PURPOSE: The aim of this study was to determine if 36-inch prone intraoperative films reflect the results at postoperative and f/up standing films. STUDY DESIGN/SETTING: Clinical Study - Diagnostic: Level IV. PATIENT SAMPLE: Forty-nine patients (46F, 3 M) Lenke type 1 (LT1) and type 3 (LT3) AIS who underwent selective thoracic fusion in a single center. OUTCOME MEASURES: Thirty-six inch standing Preoperative (Pre), prone intraoperative (Prone), Postoperative (Post) and Follow-up (Fup) x-rays were analyzed. METHODS: Proximal thoracic (PT), Main thoracic (MT) and lumbar (L) curve magnitudes, lower instrumented vertebrae tilt (LIV), angulation of the disc below LIV (LIV-disc), coronal balance (C7-CSVL) were measured in each x-ray. The intraclass correlation coefficient (ICC) 2-way mixed model on absolute agreement was used to analyze measurement reliability. RESULTS: All patients had PS instrumentation. 16 pts had LT1A 22 had LT1C, 3 had LT3B and 8 had LT3C curves. Mean age was 14.2 (11-17) and f/up was 35 months. Mean preoperative magnitudes of PT, MT and L curves were 20 (3 -37 ), 55 (40 -130 ) and 39 (25 -89 ) respectively. Mean correction rates were PT 65%, MT 76% and L 63%. There were no significant differences in terms of all curve correction and balance parameters between x-rays (pO0.05). There was a statistically significant correlation in all parameters (p!0.05) (Table 1). Compression or distraction maneuvers have been done in 16 pts based on recognition of unsatisfactory correction/ alignment in prone x-rays. None of the patients had re-interventions due to decompensation and/or increase in curve size post op or during f/up CONCLUSIONS: Routine use of intraoperative prone x-ray guides intraoperative decision-making and enables appreciation of postop and ultimate correction and balance in LT1 and LT3 pts who had selective thoracic fusion. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. http://dx.doi.org/10.1016/j.spinee.2012.08.355

P82. Decreased Bacterial Count and Biofilm Formation Associated with Silicon Nitride (Si3N4) Materials Used in Interbody Fusion Cages (IBF) Compared to Titanium and Polyetheretherketone (PEEK) Alpesh A. Patel, MD, FACS1, Thomas J. Webster, PhD2, R. Lakshminarayanan, PhD3; 1Loyola University Medical Center, Maywood, IL, US; 2Brown University, Providence, RI, US; 3Amedica, Salt Lake City, UT, US BACKGROUND CONTEXT: Infection has been reported on an array of implantable devices including orthopedic joint prosthetics and spinal implants. Moreover, the risk of infection is increasing due to the emergence of antibiotic resistance and the quick speed at which bacteria penetrate wounds developing biofilms on implants. There is, therefore, a significant interest in the development of orthopedic implant materials that inhibit. PURPOSE: To quantify the inhibitory effects of a novel silicon nitride biomaterial, used in interbody fusion cages (IBF), on bacterial function. STUDY DESIGN/SETTING: In vitro, bacterial inoculation. OUTCOME MEASURES: Bacterial biofilm production, Bacterial count. METHODS: This in vitro study tested bacterial (S. aureus, S. epidermidis, and P. aeruginosa) growth for up to 72 hours on three materials frequently used in the spine: titanium, polyetheretherketone (PEEK), and Si3N4 (Silicon Nitride). Bacterial growth was quantified by 1) Crystal violet which stains biofilm presence and 2) Live bacterial counts per high-powered field. RESULTS: Crystal violet staining demonstrated significantly less biofilm production and lower bacterial counts on Si3N4 samples compared to PEEK (p ! 0.01) and titanium samples (p ! 0.01) after 72 hours. Decreases in biofilm production were identified for all bacterial strains. S. epidermidis, S. aureus, and P. aeruginosa biofilm production was over 4, 5, and 10 times less on Si3N4 than PEEK and titanium, respectively, after 72 hours. Moreover, the number of live S. epidermidis decreased over 10

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