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P146. Direct stabilization of lumbar spondylolysis with a hook screw
180S
Proceedings of the NASS 20th Annual Meeting / The Spine Journal 5 (2005) 1S–189S
6 months postADR (88%) versus preADR (76%). 12% of patients out of work on disability were able to return to work by 6 months postADR. There were no statistical outcome differences in patients with preADR severe disc height collapse verses those with minimal collapse. CONCLUSIONS: Patients were able to significantly increase recreational activities and reduce medication use following ADR. RTW rate, even in patients out on disability may be significantly increased in patients following ADR. Patients with severe disc height collapse may experience similar improvements in outcomes as those patients with minimal disc height collapse. DISCLOSURES: FDA device/drug: Charite´ Artificial Disc (SBIII). Status: Approved for this indication. CONFLICT OF INTEREST: No conflicts.
CONCLUSIONS: Direct repair of spondylolysis can be recommended for young patients which would save a functional segment. The above mean 6 year follow-up shows encouraging results. DISCLOSURES: FDA device/drug: Hook screw. Status: Approved for this indication. CONFLICT OF INTEREST: No conflicts. doi: 10.1016/j.spinee.2005.05.361
P147. In vitro evaluation of soak time-dependent release of rhBMP-2 in the immediate postoperative environment Hyun Bae, MD1, Li Zhao, MD2, Pamela Wong, BS3, Ben Pradhan, MD1, Michael Kropf, MD1, Rick Delamarter, MD1, L.E.A. Kanim, MPH, MA1; 1 Spine Institute at Saint John’s Health Center, Santa Monica, CA, USA; 2 Saint John’s Health Center, Santa Monica, CA, USA; 3Spine Research Foundation, Santa Monica, CA, USA
doi: 10.1016/j.spinee.2005.05.360
BACKGROUND CONTEXT: Typically rhBMP-2 is applied to an absorbable type I collagen sponge (ACS) at least 15 minutes prior to implantation during a spinal fusion procedure. After careful preparation, rhBMP-2/ACS implant is placed in a surgically prepared bed or a contained site such a titanium cage or a femoral allograft. Most of the studies on BMP retention and preparation soak time have been performed before implantation. However, the biologic activation of BMP-2 occurs at implantation and the immediate postoperative period. During this critical period, the BMP-2/ACS are exposed to different cell types in a fluid sanguineous environment. PURPOSE: This in vitro study investigates the influence of preimplantation soak time on BMP-2/ACS retention in the critical postoperative period immediately after implantation. STUDY DESIGN/SETTING: In vitro. PATIENT SAMPLE: NA. OUTCOME MEASURES: NA. METHODS: Sixteen ACS sponges, 1 cm long 0.5 cm wide, 0.5 cm thick were prepared with 125 ul of 1.5mg/ml rhBMP-2 and allowed to soak for 1, 20, 60, or 120 minutes (n⫽4 sponges / soak time). The prepared sponges were then placed in normal saline solution at 37 Celsius and continuously agitated. Aliquots were withdrawn from each vial at 1, 20 minutes (shortterm soak), 1, 12 or 24 hours (long-term soak). The concentration of rhBMP-2 released from the sponge into the solution were assessed by ELISA. ANOVA was used with a grouping factor of ‘preparation soak time’ with a repeated measure for ‘sampling release time’ to test for significance. RESULTS: The concentration of rhBMP–2 released from the ACS into the saline solution was significantly decreased as a function of preparation soak times of 1, 20, 60 and 120 minutes. (The longer the prep soak time, the less rhBMP-2 in solution.) However, the difference in concentration was quite small. The concentration of rhBMP-2 significantly increased in aliquots sequentially withdrawn at 1 min, 20 min, 1 hr, 12 hrs, and 24 hrs from the same vials. (The mean rhBMP-2 concentration in fluid that was leached from the ACS was greater over time.) The pattern of release was similar for 4 preparation soak times. Overall the total amount of release
P146. Direct stabilization of lumbar spondylolysis with a hook screw Anand Agarwal, Alan Hammer; Medway Maritime Hospital, Kent, United Kingdom BACKGROUND CONTEXT: Treatment methods for spondylolisthesis in adolescents and young adults are a matter of controversial discussion. The hook screw method is a direct repair technique that permits restitutio ad integrum for a functional segment. PURPOSE: Spondylolysis with instability can produce low back pain. This technique has been successful in young adults and adolescent. This study shows the postoperative outcome of this patients. STUDY DESIGN/SETTING: A retrospective study involving 32 patients with spondylolysis who underwent direct repair with a hook screw was conducted. PATIENT SAMPLE: 34 patients who underwent direct repair for spondylolysis. OUTCOME MEASURES: OLDI score preoperative and postoperative. METHODS: A subjective study of direct repair with a hook screw for spondylolysis using the Oswestry Low Back Disability Index (OLDI) and the Short Form 36 (SF-36) Score. All the patients who underwent a direct repair with a hook screw for spondylolysis between 1996 and 2005 were contacted and asked to complete an OLDI Score and an SF-36 Score. OLDI and SF-36 scores were obtained preoperatively and postoperatively and the results compared. RESULTS: A total of 34 patients were included in this study. Response rate was 100%. Mean age of patients was 34 years. Mean preoperative OLDI score was 18 and postoperatively was 36. The results were subdivided into poor, no change, good, very good, and excellent results. Good results meant a 5–10 point improvement; very good result meant 10–15 point improvement; excellent result meant a greater than 15 point improvement. Good to excellent results were reported by 94% of patients. Good and Very Good results were reported by 23% respectively. Excellent result was reported by 76% of patients. One patient had no change and 1 was poor. Pseudoarthrosis rate was 6%.
Fig. 1.
Proceedings of the NASS 20th Annual Meeting / The Spine Journal 5 (2005) 1S–189S
6 months postADR (88%) versus preADR (76%). 12% of patients out of work on disability were able to return to work by 6 months postADR. There were no statistical outcome differences in patients with preADR severe disc height collapse verses those with minimal collapse. CONCLUSIONS: Patients were able to significantly increase recreational activities and reduce medication use following ADR. RTW rate, even in patients out on disability may be significantly increased in patients following ADR. Patients with severe disc height collapse may experience similar improvements in outcomes as those patients with minimal disc height collapse. DISCLOSURES: FDA device/drug: Charite´ Artificial Disc (SBIII). Status: Approved for this indication. CONFLICT OF INTEREST: No conflicts.
CONCLUSIONS: Direct repair of spondylolysis can be recommended for young patients which would save a functional segment. The above mean 6 year follow-up shows encouraging results. DISCLOSURES: FDA device/drug: Hook screw. Status: Approved for this indication. CONFLICT OF INTEREST: No conflicts. doi: 10.1016/j.spinee.2005.05.361
P147. In vitro evaluation of soak time-dependent release of rhBMP-2 in the immediate postoperative environment Hyun Bae, MD1, Li Zhao, MD2, Pamela Wong, BS3, Ben Pradhan, MD1, Michael Kropf, MD1, Rick Delamarter, MD1, L.E.A. Kanim, MPH, MA1; 1 Spine Institute at Saint John’s Health Center, Santa Monica, CA, USA; 2 Saint John’s Health Center, Santa Monica, CA, USA; 3Spine Research Foundation, Santa Monica, CA, USA
doi: 10.1016/j.spinee.2005.05.360
BACKGROUND CONTEXT: Typically rhBMP-2 is applied to an absorbable type I collagen sponge (ACS) at least 15 minutes prior to implantation during a spinal fusion procedure. After careful preparation, rhBMP-2/ACS implant is placed in a surgically prepared bed or a contained site such a titanium cage or a femoral allograft. Most of the studies on BMP retention and preparation soak time have been performed before implantation. However, the biologic activation of BMP-2 occurs at implantation and the immediate postoperative period. During this critical period, the BMP-2/ACS are exposed to different cell types in a fluid sanguineous environment. PURPOSE: This in vitro study investigates the influence of preimplantation soak time on BMP-2/ACS retention in the critical postoperative period immediately after implantation. STUDY DESIGN/SETTING: In vitro. PATIENT SAMPLE: NA. OUTCOME MEASURES: NA. METHODS: Sixteen ACS sponges, 1 cm long 0.5 cm wide, 0.5 cm thick were prepared with 125 ul of 1.5mg/ml rhBMP-2 and allowed to soak for 1, 20, 60, or 120 minutes (n⫽4 sponges / soak time). The prepared sponges were then placed in normal saline solution at 37 Celsius and continuously agitated. Aliquots were withdrawn from each vial at 1, 20 minutes (shortterm soak), 1, 12 or 24 hours (long-term soak). The concentration of rhBMP-2 released from the sponge into the solution were assessed by ELISA. ANOVA was used with a grouping factor of ‘preparation soak time’ with a repeated measure for ‘sampling release time’ to test for significance. RESULTS: The concentration of rhBMP–2 released from the ACS into the saline solution was significantly decreased as a function of preparation soak times of 1, 20, 60 and 120 minutes. (The longer the prep soak time, the less rhBMP-2 in solution.) However, the difference in concentration was quite small. The concentration of rhBMP-2 significantly increased in aliquots sequentially withdrawn at 1 min, 20 min, 1 hr, 12 hrs, and 24 hrs from the same vials. (The mean rhBMP-2 concentration in fluid that was leached from the ACS was greater over time.) The pattern of release was similar for 4 preparation soak times. Overall the total amount of release
P146. Direct stabilization of lumbar spondylolysis with a hook screw Anand Agarwal, Alan Hammer; Medway Maritime Hospital, Kent, United Kingdom BACKGROUND CONTEXT: Treatment methods for spondylolisthesis in adolescents and young adults are a matter of controversial discussion. The hook screw method is a direct repair technique that permits restitutio ad integrum for a functional segment. PURPOSE: Spondylolysis with instability can produce low back pain. This technique has been successful in young adults and adolescent. This study shows the postoperative outcome of this patients. STUDY DESIGN/SETTING: A retrospective study involving 32 patients with spondylolysis who underwent direct repair with a hook screw was conducted. PATIENT SAMPLE: 34 patients who underwent direct repair for spondylolysis. OUTCOME MEASURES: OLDI score preoperative and postoperative. METHODS: A subjective study of direct repair with a hook screw for spondylolysis using the Oswestry Low Back Disability Index (OLDI) and the Short Form 36 (SF-36) Score. All the patients who underwent a direct repair with a hook screw for spondylolysis between 1996 and 2005 were contacted and asked to complete an OLDI Score and an SF-36 Score. OLDI and SF-36 scores were obtained preoperatively and postoperatively and the results compared. RESULTS: A total of 34 patients were included in this study. Response rate was 100%. Mean age of patients was 34 years. Mean preoperative OLDI score was 18 and postoperatively was 36. The results were subdivided into poor, no change, good, very good, and excellent results. Good results meant a 5–10 point improvement; very good result meant 10–15 point improvement; excellent result meant a greater than 15 point improvement. Good to excellent results were reported by 94% of patients. Good and Very Good results were reported by 23% respectively. Excellent result was reported by 76% of patients. One patient had no change and 1 was poor. Pseudoarthrosis rate was 6%.
Fig. 1.