Christensen Thomas J, Annis Prokopis, Hohl Justin B, Patel Alpesh A
Department of Orthopaedics, University of Utah, 590 Wakara Way, Salt Lake City, UT 84108, USA.
Department of Orthopaedic Surgery, Northwestern University School of Medicine, 676 N St Clair St, Suite 1350, Chicago, IL 60611, USA.
Spine J. 2014 Jun 1;14(6):e23-8. doi: 10.1016/j.spinee.2013.11.028. Epub 2013 Nov 28.
Recombinant human bone morphogenetic protein-2 (rhBMP-2) is commonly used to augment posterior and interbody spinal fusion techniques and has many reported side effects. Neuroforaminal heterotopic ossification (HO) is a known cause of postoperative leg pain, but the pathohistologic composition of this material is not well understood.
The purpose of this article was to report the histologic composition of a case of HO and lumbar radiculopathy after transforaminal lumbar interbody fusion with rhBMP-2.
STUDY DESIGN/SETTING: This is a case report.
This is a single patient case report.
The outcomes considered were physician-recorded clinical, physiological, and functional measures.
A retrospective review of a single patient was performed. Clinical, radiographic, and pathologic specimens were reviewed and are reported.
A 69-year-old woman presented with low back pain and right leg radicular pain associated with L4-L5 stenosis and a recurrent facet cyst. After attempted nonsurgical care, she underwent an L4-L5 revision decompression with interbody and posterolateral fusions including off-label rhBMP-2. Postoperatively, her symptoms resolved for approximately 7 months but then returned in association with right L4-L5 foraminal HO. The ectopic tissue was notably larger than suggested by preoperative computed tomographic scan. It was decompressed, which then improved her symptoms. Histologic examination of the specimen revealed three discrete tissue types: a nonspecific fibrovascular stroma; immature osteoid and woven bone; and chondrocyte metaplasia with chondrocyte clustering.
Neuroforaminal HO formation is a reported side effect associated with the off-label use of rhBMP-2 for posterior lumbar interbody fusion. The mechanism of formation and the composition of this material are not well understood but may involve a chondrocyte differentiation pathway.
重组人骨形态发生蛋白-2（rhBMP-2）常用于增强后路和椎间融合技术，且有许多副作用报道。神经孔异位骨化（HO）是术后腿痛的已知原因，但这种物质的病理组织学组成尚不清楚。
本文旨在报告1例经椎间孔腰椎椎间融合术使用rhBMP-2后发生HO和腰椎神经根病的组织学组成。
研究设计/场所：这是1例病例报告。
这是1例患者的病例报告。
观察指标为医生记录的临床、生理和功能指标。
对1例患者进行回顾性分析。回顾并报告了临床、影像学和病理标本。
1名69岁女性因L4-L5狭窄和复发性小关节囊肿出现腰痛和右腿根性疼痛。在尝试非手术治疗后，她接受了L4-L5翻修减压术，包括椎间融合和后外侧融合，并使用了超适应证的rhBMP-2。术后，她的症状缓解了约7个月，但随后因右侧L4-L5神经孔HO复发。异位组织明显比术前计算机断层扫描显示的要大。对其进行减压后，症状得到改善。标本的组织学检查显示有三种不同的组织类型：非特异性纤维血管基质；未成熟类骨质和编织骨；软骨细胞化生伴软骨细胞聚集。
神经孔HO形成是rhBMP-2超适应证用于腰椎后路椎间融合术的一种副作用。这种物质的形成机制和组成尚不清楚，但可能涉及软骨细胞分化途径。
