title: Guideline update for the performance of fusion procedures for degenerative disease of the lumbar spine. Part 4: radiographic assessment of fusion status.
abstract: The ability to identify a successful arthrodesis is an essential element in the management of patients undergoing lumbar fusion procedures. The hypothetical gold standard of intraoperative exploration to identify, under direct observation, a solid arthrodesis is an impractical alternative. Therefore, radiographic assessment remains the most viable instrument to evaluate for a successful arthrodesis. Static radiographs, particularly in the presence of instrumentation, are not recommended. In the absence of spinal instrumentation, lack of motion on flexion-extension radiographs is highly suggestive of a successful fusion; however, motion observed at the treated levels does not necessarily predict pseudarthrosis. The degree of motion on dynamic views that would distinguish between a successful arthrodesis and pseudarthrosis has not been clearly defined. Computed tomography with fine-cut axial images and multiplanar views is recommended and appears to be the most sensitive for assessing fusion following instrumented posterolateral and anterior lumbar interbody fusions. For suspected symptomatic pseudarthrosis, a combination of techniques including static and dynamic radiographs as well as CT images is recommended as an option. Lack of facet fusion is considered to be more suggestive of a pseudarthrosis compared with absence of bridging posterolateral bone. Studies exploring additional noninvasive modalities of fusion assessment have demonstrated either poor potential, such as with (99m)Tc bone scans, or provide insufficient information to formulate a definitive recommendation.
authors: Department of Neurosurgery, Icahn School of Medicine at Mount Sinai, New York, New York;
authors: Tanvir F
authors: TF
authors: Choudhri
authors: Praveen V
authors: PV
authors: Mummaneni
authors: Sanjay S
authors: SS
authors: Dhall
authors: Jason C
authors: JC
authors: Eck
authors: Michael W
authors: MW
authors: Groff
authors: Zoher
authors: Z
authors: Ghogawala
authors: William C
authors: WC
authors: Watters
authors: Andrew T
authors: AT
authors: Dailey
authors: Daniel K
authors: DK
authors: Resnick
authors: Alok
authors: A
authors: Sharan
authors: Jeffrey C
authors: JC
authors: Wang
authors: Michael G
authors: MG
authors: Kaiser
mesh_terms: D019317:Evidence-Based Medicine; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D010780:Photogrammetry; D049268:Positron-Emission Tomography; D011183:Postoperative Complications / Q000000981:diagnostic imaging* / Q000473:pathology; D017410:Practice Guidelines as Topic; D013122:Spinal Diseases / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D013123:Spinal Fusion / Q000592:standards*; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: ALIF = anterior lumbar interbody fusion; AP = anteroposterior; NPV = negative predictive value; PLF = posterolateral lumbar fusion; PLIF = posterior lumbar interbody fusion; PPV = positive predictive value; RSA = roentgen stereophotogrammetric analysis; diagnostic techniques; fusion; lumbar spine; practice guidelines