title: Hydroxyapatite block for use in posterolateral lumbar fusion: a report of four cases.
abstract: Autologous bone grafts for posterolateral lumbar fusion are harvested from the iliac crests. Recently, several alternatives to autologous bone have been evaluated (such as graft substitutes, graft extenders, or both) with variable results. However, no clinical long-term studies have validated the efficacy of these techniques in posterolateral lumbar fusion. This study evaluated radiographic and histologic findings in four patients (mean age, 66 years) during the first 5 years after posterolateral fusion with an hydroxyapatite block. The mean followup was 7 years 1 month. Radiologic evaluation was by plain radiographs and computed tomography scans. Histologic evaluation was done in one patient. Capillaries extended into the porous structure of the hydroxyapatite substrate, and some of the pores were replaced by newly formed bone tissue. The long-term results of graft substitutes were stable and hydroxyapatite appeared to have some potential to achieve union in posterolateral lumbar fusion. However, hydroxyapatite block alone has not functioned effectively as a complete graft substitute in posterolateral lumbar fusion. Thus, a suitable osteogenic material is required to induce the formation of new bone and achieve a solid union.
authors: Department of Orthopedic Surgery, Miyazaki Medical College, 5200 Kihara Kiyotake, Miyazaki 889-1692, Japan. totoribe@post1.miyazaki-med.ac.jp.
authors: Koji
authors: K
authors: Totoribe
authors: Naoya
authors: N
authors: Tajima
authors: Etsuo
authors: E
authors: Chosa
authors: Masanori
authors: M
authors: Matsumoto
authors: Hiroaki
authors: H
authors: Kataoka
authors: Masashi
authors: M
authors: Koono
mesh_terms: D000368:Aged; D001672:Biocompatible Materials; D001707:Biopsy, Needle; D017886:Durapatite / Q000494:pharmacology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007796:Laminectomy / Q000379:methods; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D013123:Spinal Fusion / Q000379:methods*; D013130:Spinal Stenosis / Q000175:diagnosis* / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D001672:Biocompatible Materials; D017886:Durapatite