A n optimal device for facilitating spinal fusion would be rigid at the time of implantation and becoming less so over time as bone growth develops to a mature arthrodesis; the implant would then degrade and become absorbed in the normal healing process. This ideal stabilizing, load-sharing implant would minimize the effects of stress shielding and device-related osteopenia associated with some metallic devices. It would enhance radiographic detection of an osseous fusion and eliminate the potential need for later explanantion. Bioresorbable polymers, which
David W. Cahill, George J. Martin Jr., Michael V. Hajjar, William Sonstein, Lloyd B. Graham and Robert W. Engelman
Dachling Pang, Herman H. Tse, Marike Zwienenberg-Lee, Matthew Smith and John Zovickian
undesirable for use in children, however, due to the possibility of permanent growth impedance in the expanding cranium. 7 In addition, metallic underplates interfere with MR imaging. For the past 4 years, we have been using a bioresorbable plate countersunk into the cranial defect to act as a solid scaffolding; we fill this plate with HAC to provide suitable contouring. In this report we describe the technique in detail and analyze our results with 15 cases. Clinical Material and Methods Patient Population Fifteen children (seven boys and eight girls) ages 2 to
Paul C. Francel, Kevin S. Smith, F. Alan Stevens, Soon C. Kim, James Gossett, Cynthia Gossett, Mark E. Davis, Marc Lenaerts and Paul Tompkins
humans is not practical. The use of a bioresorbable material for conduit construction offers significant advantages when dealing with repair of nerve defects in humans. The purpose of our study was to evaluate nerve regeneration through a conduit composed of a commercially available bioresorbable material (LactoSorb; Walter Lorenz Surgical, Inc., Jacksonville, FL). Regeneration parameters were compared with both reverse autograft and silicone tube—enhanced regeneration models. Materials and Methods These studies were approved by the local Institutional Animal
Yoshihisa Kotani, Kuniyoshi Abumi, Yasuo Shikinami, Masahiko Takahata, Ken Kadoya, Tsuyoshi Kadosawa, Akio Minami and Kiyoshi Kaneda
and biomechanical effects of AID replacement, this 2-year study was conducted using a sheep lumbar spine model. We also focused on the use of bioresorbable spinal stabilization combined with the AID, providing both initial spinal stabilization and late mobilization after degradation of material. Materials and Methods Design and Biomechanical Properties of the AID The triaxial 3D fabric disc was a semielliptically shaped near-net woven with an UHMWPE fiber bundle, which was coated by linear low-density polyethylene ( Fig. 1 ). 18, 21, 28, 31 The 3D fabric
Kevin T. Foley, Eric J. Woodard, Jonathan R. Slotkin, Cassandra K. Mayotte, Abigail C. Baldwin, Michael C. Brown and Brian J. Hess
in 1.6% of cases. 5 Composed of a wet-field self-setting aqueous-based reaction comprising tetracalcium phosphate and phosphoserine, TTCP-PS is a novel, bioresorbable bone adhesive. When initially mixed, TTCP-PS maintains a tacky-adhesive character through its initial setting process. It cures within minutes after application and produces a durable adhesive with load-bearing bond strength to wet bone tissue and metals. TTCP-PS has been studied in a canine model for dental implant stabilization 1 and was recently approved by the Food and Drug Administration for
Christopher P. Ames, Neil R. Crawford, Robert H. Chamberlain, Vivek Deshmukh, Belma Sadikovic and Volker K. H. Sonntag
one or two screws are biomechanically equivalent in terms of fracture stabilization. Because the screw required for repairing the odontoid fracture is no longer beneficial after fusion has occurred and, in fact, may limit (secondary to stress shielding) the extent of desirable bone remodeling, an odontoid repair technique in which the screw disappears after fusion is theoretically desirable. A bioresorbable odontoid screw made of 70:30 poly(L-lactide-co-D,L-lactide), or PLDLA, was developed as an alternative to a metallic screw designed for direct fixation of Type
Gerald F. Tuite, Carolyn M. Carey, William W. Nelson, Scott J. Raffa and S. Parrish Winesett
inferomedial side of the SSS during hemispherotomy in an 11-kg infant. After considering and attempting many of the typical options, we were able to successfully stop the hemorrhage by fashioning a bioresorbable plate to hold packing material firmly against the medial surface of the SSS. Case Report Initial Operation This 11-kg, 11-month-old boy was selected for left peri-insular hemispherotomy 3 , 6 , 7 , 17 , 19 , 27 , 38 due to medically refractory epilepsy related to a large, left hemisphere, perinatal stroke ( Fig. 1 ). The surgical approach proceeded
G. Bryan Cornwall, Christopher P. Ames, Neil R. Crawford, Robert H. Chamberlain, Anthony M. Rubino, Howard B. Seim III and A. Simon Turner
An in vivo study was conducted in an ovine model to investigate the biomechanical changes after the animals underwent single-level anterior cervical discectomy followed by fusion in which autologous tricortical graft was used and implantation of cervical plates for which bioresorbable polymer screws and plates were used. The specific aims of the study were to evaluate whether implant failure or screw backout would occur over time and to measure the change in stiffness at the treated level at various postoperative time periods (3, 6, and 12 months).
A total of 58 x-ray films were evaluated over the 12-month survival period. No screw breakage or displacement was observed in any animal during the temporal radiographic analysis. Radiographically confirmed fusion appeared to be complete at all time periods longer than 6 months. The biomechanical testing demonstrated dramatic reductions in range of motion at the fusion level in the animals allowed to survive for 6 and 12 months, indicating complete fusion after 6 months.
The bioresorbable polymer cervical graft containment system appears to provide a safe and effective alternative for cervical fusion, and warrants further clinical evaluation for its use in single-level anterior cervical discectomy and fusion without postoperative orthosis.
Todd H. Lanman and Thomas J. Hopkins
To evaluate the effectiveness of recombinant human bone morphogenetic protein–2 (rhBMP-2) combined with a bioresorbable implant, the authors conducted a prospective study of 43 patients with degenerative lumbar disc disease who underwent transforaminal lumbar interbody fusion.
The authors used Infuse bone graft, which consisted of rhBMP-2 applied to an absorbable collagen sponge and contained within a HYDROSORB Telamon bioresorbable implant to perform the fusion. Multilevel fusions were performed in 30% of the 43 patients, for a total of 57 levels. At 6 months postoperatively, x-ray films and computerized tomography (CT) scans demonstrated solid fusion in 98% of 41 patients. Improvement from the baseline Oswestry Disability Rating was demonstrated at 6 months postoperatively in 68% of the patients, based on the Oswestry Disability Questionnaire. At 12 months all 11 patients in whom CT scans were obtained showed complete bridging of bone; there were no device-related complications.
Results in this series provide evidence of the feasibility of using HYDROSORB Telamon biore-sorbable spacers in combination with Infuse bone graft for lumbar spine fusion.
Philipp R. Aldana, Saswata Roy, Richard A. Postlethwait and Hector E. James
to screw placement, and poor screw purchase can occur if the proper technique is not used. 10 Tack fixation requires that a significant amount of force be applied to the tack to drive it securely into the bone; this can be difficult on a pliant infant skull. Ultrasound-aided fixation of bioresorbable implants is a recently developed alternative method. A bioresorbable pin is mounted to the tip of a device which then vibrates the pin to ultrasonic speeds. As the vibrating pin is inserted into the hole drilled into the bone, the friction generated at the pin