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 99mTc bone scans, or provide insufficient information to formulate a definitive recommendation.
Tanvir F. Choudhri, Praveen V. Mummaneni, Sanjay S. Dhall, Jason C. Eck, Michael W. Groff, Zoher Ghogawala, William C. Watters III, Andrew T. Dailey, Daniel K. Resnick, Alok Sharan, Jeffrey C. Wang and Michael G. Kaiser
Sanjay S. Dhall, Tanvir F. Choudhri, Jason C. Eck, Michael W. Groff, Zoher Ghogawala, William C. Watters III, Andrew T. Dailey, Daniel K. Resnick, Alok Sharan, Praveen V. Mummaneni, Jeffrey C. Wang and Michael G. Kaiser
In an effort to diminish pain or progressive instability, due to either the pathological process or as a result of surgical decompression, one of the primary goals of a fusion procedure is to achieve a solid arthrodesis. Assuming that pain and disability result from lost mechanical integrity of the spine, the objective of a fusion across an unstable segment is to eliminate pathological motion and improve clinical outcome. However, conclusive evidence of this correlation, between successful fusion and clinical outcome, remains elusive, and thus the necessity of documenting successful arthrodesis through radiographic analysis remains debatable. Although a definitive cause and effect relationship has not been demonstrated, there is moderate evidence that demonstrates a positive association between radiographic presence of fusion and improved clinical outcome. Due to this growing body of literature, it is recommended that strategies intended to enhance the potential for radiographic fusion are considered when performing a lumbar arthrodesis for degenerative spine disease.
Jason C. Eck, Alok Sharan, Daniel K. Resnick, William C. Watters III, Zoher Ghogawala, Andrew T. Dailey, Praveen V. Mummaneni, Michael W. Groff, Jeffrey C. Wang, Tanvir F. Choudhri, Sanjay S. Dhall and Michael G. Kaiser
Identifying the etiology of pain for patients suffering from chronic low-back pain remains problematic. Noninvasive imaging modalities, used in isolation, have not consistently provided sufficient evidence to support performance of a lumbar fusion. Provocative testing has been used as an adjunct in this assessment, either alone or in combination with other modalities, to enhance the diagnostic capabilities when evaluating patients with low-back pain. There have been a limited number of studies investigating this topic since the publication of the original guidelines. Based primarily on retrospective studies, discography, as a stand-alone test, is not recommended to formulate treatment strategies for patients with low-back pain. A single randomized cohort study demonstrated an improved potential of discoblock over discography as a predictor of success following lumbar fusion. It is therefore recommended that discoblock be considered as a diagnostic option. There is a possibility, based on a matched cohort study, that an association exists between progression of degenerative disc disease and the performance of a provocative discogram. It is therefore recommended that patients be counseled regarding this potential development prior to undergoing discography.
Jason C. Eck, Alok Sharan, Zoher Ghogawala, Daniel K. Resnick, William C. Watters III, Praveen V. Mummaneni, Andrew T. Dailey, Tanvir F. Choudhri, Michael W. Groff, Jeffrey C. Wang, Sanjay S. Dhall and Michael G. Kaiser
Establishing an appropriate treatment strategy for patients presenting with low-back pain, in the absence of stenosis or spondylolisthesis, remains a controversial subject. Inherent to this situation is often an inability to adequately identify the source of low-back pain to justify various treatment recommendations, such as lumbar fusion. The current evidence does not identify a single best treatment alternative for these patients. Based on a number of prospective, randomized trials, comparable outcomes, for patients presenting with 1- or 2-level degenerative disc disease, have been demonstrated following either lumbar fusion or a comprehensive rehabilitation program with a cognitive element. Limited access to such comprehensive rehabilitative programs may prove problematic when pursuing this alternative. For patients whose pain is refractory to conservative care, lumbar fusion is recommended. Limitations of these studies preclude the ability to present the most robust recommendation in support of lumbar fusion. A number of lesser-quality studies, primarily case series, also support the use of lumbar fusion in this patient population.
Jeffrey C. Wang, Andrew T. Dailey, Praveen V. Mummaneni, Zoher Ghogawala, Daniel K. Resnick, William C. Watters III, Michael W. Groff, Tanvir F. Choudhri, Jason C. Eck, Alok Sharan, Sanjay S. Dhall and Michael G. Kaiser
Patients suffering from a lumbar herniated disc will typically present with signs and symptoms consistent with radiculopathy. They may also have low-back pain, however, and the source of this pain is less certain, as it may be from the degenerative process that led to the herniation. The surgical alternative of choice remains a lumbar discectomy, but fusions have been performed for both primary and recurrent disc herniations. In the original guidelines, the inclusion of a fusion for routine discectomies was not recommended. This recommendation continues to be supported by more recent evidence. Based on low-level evidence, the incorporation of a lumbar fusion may be considered an option when a herniation is associated with evidence of spinal instability, chronic low-back pain, and/or severe degenerative changes, or if the patient participates in heavy manual labor. For recurrent disc herniations, there is low-level evidence to support the inclusion of lumbar fusion for patients with evidence of instability or chronic low-back pain.
Daniel K. Resnick, William C. Watters III, Alok Sharan, Praveen V. Mummaneni, Andrew T. Dailey, Jeffrey C. Wang, Tanvir F. Choudhri, Jason Eck, Zoher Ghogawala, Michael W. Groff, Sanjay S. Dhall and Michael G. Kaiser
Patients presenting with stenosis associated with a spondylolisthesis will often describe signs and symptoms consistent with neurogenic claudication, radiculopathy, and/or low-back pain. The primary objective of surgery, when deemed appropriate, is to decompress the neural elements. As a result of the decompression, the inherent instability associated with the spondylolisthesis may progress and lead to further misalignment that results in pain or recurrence of neurological complaints. Under these circumstances, lumbar fusion is considered appropriate to stabilize the spine and prevent delayed deterioration. Since publication of the original guidelines there have been a significant number of studies published that continue to support the utility of lumbar fusion for patients presenting with stenosis and spondylolisthesis. Several recently published trials, including the Spine Patient Outcomes Research Trial, are among the largest prospective randomized investigations of this issue. Despite limitations of study design or execution, these trials have consistently demonstrated superior outcomes when patients undergo surgery, with the majority undergoing some type of lumbar fusion procedure. There is insufficient evidence, however, to recommend a standard approach to achieve a solid arthrodesis. When formulating the most appropriate surgical strategy, it is recommended that an individualized approach be adopted, one that takes into consideration the patient's unique anatomical constraints and desires, as well as surgeon's experience.
Daniel K. Resnick, William C. Watters III, Praveen V. Mummaneni, Andrew T. Dailey, Tanvir F. Choudhri, Jason C. Eck, Alok Sharan, Michael W. Groff, Jeffrey C. Wang, Zoher Ghogawala, Sanjay S. Dhall and Michael G. Kaiser
Lumbar stenosis is one of the more common radiographic manifestations of the aging process, leading to narrowing of the spinal canal and foramen. When stenosis is clinically relevant, patients often describe activity-related low-back or lower-extremity pain, known as neurogenic claudication. For those patients who do not improve with conservative care, surgery is considered an appropriate treatment alternative. The primary objective of surgery is to reconstitute the spinal canal. The role of fusion, in the absence of a degenerative deformity, is uncertain. The previous guideline recommended against the inclusion of lumbar fusion in the absence of spinal instability or a likelihood of iatrogenic instability. Since the publication of the original guidelines, numerous studies have demonstrated the role of surgical decompression in this patient population; however, few have investigated the utility of fusion in patients without underlying instability. The majority of studies contain a heterogeneous cohort of subjects, often combining patients with and without spondylolisthesis who received various surgical interventions, limiting fusions to those patients with instability. It is difficult if not impossible, therefore, to formulate valid conclusions regarding the utility of fusion for patients with uncomplicated stenosis. Lower-level evidence exists, however, that does not demonstrate an added benefit of fusion for these patients; therefore, in the absence of deformity or instability, the inclusion of a fusion is not recommended.
Praveen V. Mummaneni, Sanjay S. Dhall, Jason C. Eck, Michael W. Groff, Zoher Ghogawala, William C. Watters III, Andrew T. Dailey, Daniel K. Resnick, Tanvir F. Choudhri, Alok Sharan, Jeffrey C. Wang and Michael G. Kaiser
Interbody fusion techniques have been promoted as an adjunct to lumbar fusion procedures in an effort to enhance fusion rates and potentially improve clinical outcome. The medical evidence continues to suggest that interbody techniques are associated with higher fusion rates compared with posterolateral lumbar fusion (PLF) in patients with degenerative spondylolisthesis who demonstrate preoperative instability. There is no conclusive evidence demonstrating improved clinical or radiographic outcomes based on the different interbody fusion techniques. The addition of a PLF when posterior or anterior interbody lumbar fusion is performed remains an option, although due to increased cost and complications, it is not recommended. No substantial clinical benefit has been demonstrated when a PLF is included with an interbody fusion. For lumbar degenerative disc disease without instability, there is moderate evidence that the standalone anterior lumbar interbody fusion (ALIF) has better clinical outcomes than the ALIF plus instrumented, open PLF. With regard to type of interbody spacer used, frozen allograft is associated with lower pseudarthrosis rates compared with freeze-dried allograft; however, this was not associated with a difference in clinical outcome.
Zoher Ghogawala, Daniel K. Resnick, William C. Watters III, Praveen V. Mummaneni, Andrew T. Dailey, Tanvir F. Choudhri, Jason C. Eck, Alok Sharan, Michael W. Groff, Jeffrey C. Wang, Sanjay S. Dhall and Michael G. Kaiser
Assessment of functional patient-reported outcome following lumbar spinal fusion continues to be essential for comparing the effectiveness of different treatments for patients presenting with degenerative disease of the lumbar spine. When assessing functional outcome in patients being treated with lumbar spinal fusion, a reliable, valid, and responsive outcomes instrument such as the Oswestry Disability Index should be used. The SF-36 and the SF-12 have emerged as dominant measures of general health-related quality of life. Research has established the minimum clinically important difference for major functional outcomes measures, and this should be considered when assessing clinical outcome. The results of recent studies suggest that a patient's pretreatment psychological state is a major independent variable that affects the ability to detect change in functional outcome.
Michael W. Groff, Andrew T. Dailey, Zoher Ghogawala, Daniel K. Resnick, William C. Watters III, Praveen V. Mummaneni, Tanvir F. Choudhri, Jason C. Eck, Alok Sharan, Jeffrey C. Wang, Sanjay S. Dhall and Michael G. Kaiser
The utilization of pedicle screw fixation as an adjunct to posterolateral lumbar fusion (PLF) has become routine, but demonstration of a definitive benefit remains problematic. The medical evidence indicates that the addition of pedicle screw fixation to PLF increases fusion rates when assessed with dynamic radiographs. More recent evidence, since publication of the 2005 Lumbar Fusion Guidelines, suggests a stronger association between radiographic fusion and clinical outcome, although, even now, no clear correlation has been demonstrated. Although several reports suggest that clinical outcomes are improved with the addition of pedicle screw fixation, there are conflicting findings from similarly classified evidence. Furthermore, the largest contemporary, randomized, controlled study on this topic failed to demonstrate a significant clinical benefit with the use of pedicle screw fixation in patients undergoing PLF for chronic low-back pain. This absence of proof should not, however, be interpreted as proof of absence. Several limitations continue to compromise these investigations. For example, in the majority of studies the sample size is insufficient to detect small increments in clinical outcome that may be observed with pedicle screw fixation. Therefore, no definitive statement regarding the efficacy of pedicle screw fixation as a means to improve functional outcomes in patients undergoing PLF for chronic low-back pain can be made. There appears to be consistent evidence suggesting that pedicle screw fixation increases the costs and complication rate of PLF. High-risk patients, including (but not limited to) patients who smoke, patients who are undergoing revision surgery, or patients who suffer from medical conditions that may compromise fusion potential, may appreciate a greater benefit with supplemental pedicle screw fixation. It is recommended, therefore, that the use of pedicle screw fixation as a supplement to PLF be reserved for those patients in whom there is an increased risk of nonunion when treated with only PLF.