Utility of postoperative radiographs for cervical spine fusion: a comprehensive evaluation of operative technique, surgical indication, and duration since surgery

Physiologic Osseous Remodeling of the Anterior Wall of the Spinal Canal after Anterior Cervical Corpectomy and Fusion: A Retrospective Observational Study

BACKGROUND

 Anterior cervical corpectomy and fusion (ACCF) has been widely used in the treatment of cervical spondylotic myelopathy (CSM), ossification of posterior longitudinal ligament (OPLL), cervical trauma, and other cervical diseases, but few studies have reported the osseous and physiologic remodeling of the anterior wall of the spinal canal following ACCF. In this study, we analyze that remodeling process and its influence on titanium mesh cage (TMC) subsidence.

METHODS

 We performed a clinical and radiologic analysis of consecutive patients treated with ACCF. Growth rates (GRs) reflecting the extent of remodeling of the remnants of the resected vertebral bodies were measured. We compared the computed tomography (CT) scans taken immediately and at least 1 year after surgery, and a literature review was conducted.

RESULTS

 In all, 48 patients underwent ACCF at a mean age of 61.5 ± 12.0 years. The median follow-up was 36 months, and 159 CT images were analyzed. The GR values of the remnants of the vertebral bodies on CT images immediately and 1 year after surgery were 0.505 ± 0.077 and 0.650 ± 0.022 (p < 0.001), respectively, and the GR value at ≥4 years was 1. Axial CT scans showed that remodeling starts from the lateral remnants of the resected vertebral bodies, finally reaching the center. When fusion of the vertebral bodies and the titanium cage was complete during the first year after ACCF, osteogenesis and remodeling were initiated in the osseous anterior wall of the spinal canal. The remodeling of the osseous anterior wall of the spinal canal was completed at the fourth year after surgery, without recompressing the spinal cord, as seen on both axial and lateral CT scans. According to the literature review, there was no TMC subsidence at more than 4 years after surgery.

CONCLUSION

 The anterior wall of the spinal canal undergoes osseous remodeling after ACCF. The process is complete in the fourth year after surgery and prevents TMC subsidence.

Why X-rays? The importance of radiographs in spine surgery

Despite the advances made in high-resolution spinal imaging, plain films (radiographs or x-rays) remain a cornerstone of evaluating and caring for spine patients in the preoperative, intraoperative, and postoperative settings. Although often undervalued when compared with more advanced imaging such as MRIs or CT scans, plain films provide surgeons invaluable information that other imaging modalities oftentimes cannot. In addition to their use during surgery for localization or evaluation of hardware placement, x-rays provide an overall image of a patient's spine, are useful in evaluating hardware complications, allow detailed assessment of alignment and stability and allow for repeated images in clinic during follow-up. Plain films continue to provide critical information that cannot be obtained with other imaging modalities, and they remain central to providing optimal care for spine patients.

Clinical Utility of Routine Postoperative Imaging in Spinal Fusion Surgery: A Systematic Review

OBJECTIVE

Following spinal fusion surgery, routine imaging is often obtained in all patients regardless of clinical presentation. Such routine imaging may include x-ray, computed tomography, or magnetic resonance imaging studies in both the immediate postoperative period and after discharge. The clinical utility of this practice is questionable. Our goal is to assess the existing literature for evidence of impact on clinical care from routine radiographic surveillance following spinal fusion.

METHODS

A systematic search of Embase, Scopus, PubMed, Cochrane, and Ovid databases was performed for studies investigating postoperative imaging following spinal fusion surgery. Studies were analyzed for imaging findings and rates of change in management due to imaging.

RESULTS

In total, the review identified 9 studies that separated data by unique patient or by unique clinic visits. The 4 studies reporting per-patient data totaled 475 patients with 328 (69%) receiving routine imaging. Among these, 28 (8.5%) patients had abnormal routine findings with no patients having a change to their clinical course. Of the 5 studies that reported clinic visit data, 3119 patient visits were included with 2365 (76%) clinic visits accompanied by imaging. Across these 5 studies, 146 (6.2%) visits noted abnormal imaging with only 12 (0.5%) subsequent management changes.

CONCLUSIONS

Our analysis found that routine imaging after spinal fusion surgery had no direct benefit on clinical management. The utility of baseline imaging for long-term comparison and medicolegal concerns were not studied and remain up to the provider's judgment. Further research is necessary to identify optimal imaging criteria following spinal fusion surgery.

Characterizing and quantifying low-value diagnostic imaging internationally: a scoping review

BACKGROUND

Inappropriate and wasteful use of health care resources is a common problem, constituting 10-34% of health services spending in the western world. Even though diagnostic imaging is vital for identifying correct diagnoses and administrating the right treatment, low-value imaging-in which the diagnostic test confers little to no clinical benefit-is common and contributes to inappropriate and wasteful use of health care resources. There is a lack of knowledge on the types and extent of low-value imaging. Accordingly, the objective of this study was to identify, characterize, and quantify the extent of low-value diagnostic imaging examinations for adults and children.

METHODS

A scoping review of the published literature was performed. Medline-Ovid, Embase-Ovid, Scopus, and Cochrane Library were searched for studies published from 2010 to September 2020. The search strategy was built from medical subject headings (Mesh) for Diagnostic imaging/Radiology OR Health service misuse/Medical overuse OR Procedures and Techniques Utilization/Facilities and Services Utilization. Articles in English, German, Dutch, Swedish, Danish, or Norwegian were included.

RESULTS

A total of 39,986 records were identified and, of these, 370 studies were included in the final synthesis. Eighty-four low-value imaging examinations were identified. Imaging of atraumatic pain, routine imaging in minor head injury, trauma, thrombosis, urolithiasis, after thoracic interventions, fracture follow-up and cancer staging/follow-up were the most frequently identified low-value imaging examinations. The proportion of low-value imaging varied between 2 and 100% inappropriate or unnecessary examinations.

CONCLUSIONS

A comprehensive list of identified low-value radiological examinations for both adults and children are presented. Future research should focus on reasons for low-value imaging utilization and interventions to reduce the use of low-value imaging internationally.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO: CRD42020208072.

Routine In-Hospital Radiographs Following Anterior Cervical Discectomy and Fusion Surgery: Neither Necessary nor Cost-Effective?

Background

Despite a paucity of evidence or literature to support routine in-hospital post-operative radiographs (POXR) of anterior cervical discectomy and fusion (ACDF) surgery, it remains accepted practice. Most spinal surgeons consider it part of their standard post-operative routine for ACDF despite nearly always documenting a ’satisfactory intra-operative image’ at the end of the operation. With an increasing financial pressure on NHS resources, our investigations should be clinically justified and evidence-based.

Purpose

To evaluate whether a post-operative radiograph of the cervical spine before discharge is either clinically justified or cost-effective in patients who have undergone an ACDF, despite having satisfactory intra-operative imaging.

Design

A retrospective review of 101 consecutive ACDF patients of radiographs performed before discharge, associated length of inpatient stay, and any complications involved.

Methods

A retrospective review was performed of 101 ACDF patients who had single or multi-level instrumentation for degenerative spinal disease from a single neurosurgical centre from all surgeons. Seventy-eight had an in-hospital post-operative anteroposterior (AP) and lateral radiograph, 23 did not. In 95 of these, it was documented that there was ‘satisfactory intra-operative imaging’ before the closure of skin, six lacked documentation of this. All patients had intra-operative imaging of completed instrumentation on the radiology system. Any post-operative complications were noted, and the length of hospital stay (LOS) was recorded. Six patients underwent ACDF following trauma, therefore leaving 95 elective cases. Study parameters also included: number of levels operated on, whether or not a plate was used with a cage, hospital costings for 2-view imaging and additional days of inpatient stay. 

Results

There was one out of our 101 patients where the post-operative radiograph confirmed unsatisfactory placement of metalwork and warranted a return to surgery. However, the decision to perform this x-ray was based purely on the deteriorating post-operative clinical picture. In the cohort that had POXR’s, the average length of stay was 66.7 hours. Without POXR, it was 21 hours. The additional cost to the trust of performing the in-hospital radiographs was calculated to be £71,523 per year.

Conclusion

In patients who undergo ACDF surgery with an uneventful post-operative course and have satisfactory intra-operative imaging, in-hospital post-operative radiographs serve no clinical purpose and delay discharge. This gives additional cost to the trust, unnecessary radiation exposure and occupies potential bedspace.

Immediate Postoperative Imaging Following Elective Lumbar Fusion Provides Little Clinical Utility

STUDY DESIGN

Retrospective review at a single institution of all adult patients who underwent elective lumbar fusion surgery for degenerative spinal disease from 2013 to 2018. Reoperation rates and change in clinical management due to routine imaging findings were the primary outcomes.

OBJECTIVE

To investigate what effects immediate routine postoperative imaging has on the clinical management of patients following lumbar fusion surgery.

SUMMARY OF BACKGROUND DATA

The clinical utility of routine postoperative imaging following lumbar fusion surgery remains uncertain. Existing studies on the clinical utility of postoperative imaging in lumbar fusion patients have largely focused on imaging obtained post-discharge. We present a retrospective analysis that to our knowledge is the first study reporting on the clinical utility of routine imaging in lumbar fusion patients during the immediate postoperative period.

METHODS

The medical records of patients who had undergone elective lumbar instrumented fusion for degenerative disease from 2013 to 2018 by neurosurgeons across one regional healthcare system were retrospectively analyzed. Inpatient records and imaging orders for patients were reviewed. Routine immediate postoperative imaging was defined by any lumbar spine imaging prior to discharge in the absence of specific indications.

RESULTS

Analysis identified 115 patients who underwent elective lumbar instrumented fusion for degenerative disease. One-hundred-twelve patients received routine postoperative imaging. Routine imaging was abnormal in four patients (4%). There was one instance (<1%) where routine immediate postoperative imaging led to change in clinical management. Abnormal routine imaging was not associated with either reoperation or development of neurological symptoms postoperatively (P = 0.10), however, new or worsening neurologic deficits did predict reoperation (P < 0.01).

CONCLUSION

New neurologic deficit was the only significant predictor of reoperation. Routine imaging, whether normal or abnormal, was not found to be associated with reoperation. The practice of routine imaging prior to discharge following elective lumbar fusion surgery appears to provide little utility to clinical management.Level of Evidence: 3.

Evaluation of Benefit and Cost Utility of Immediate Postanesthesia Care Unit Radiographs to Predict Airway Compromise After Anterior Cervical Discectomy and Fusion

STUDY DESIGN

Retrospective review.

OBJECTIVE

Anterior cervical discectomy and fusion (ACDF) is a commonly performed procedure that may be complicated by airway compromise postoperatively. This life-threatening complication may necessitate reintubation and reoperation. We evaluated the cost utility of conventional postoperative x-ray.

SUMMARY OF BACKGROUND DATA

Studies have demonstrated minimal benefit in obtaining an x-ray on postoperative day 1, but there is some utility of postanesthesia care unit (PACU) x-rays for predicting the likelihood of reoperation.

METHODS

We retrospectively reviewed the records of consecutive patients who underwent ACDF between September 2013 and February 2017. Patients were dichotomized into those who received PACU x-rays and those who did not (control group). Primary outcomes were reoperation, reintubation, mortality, and health care costs.

RESULTS

Eight-hundred and fifteen patients were included in our analysis: 558 had PACU x-rays; 257 did not. In those who received PACU x-rays, mean age was 53.7 ± 11.3 years, mean levels operated on were 2.0 ± 0.79, and mean body mass index (BMI) was 30.3 ± 6.9. In those who did not, mean age was 51.8 ± 10.9 years, mean levels operated on were 1.48 ± 0.65, and mean BMI was 29.9 ± 6.3. Complications in the PACU x-ray group were reintubation-0.4%, reoperation-0.7%, and death-0.3% (due to prevertebral swelling causing airway compromise). Complications in the control group were reintubation-0.4%, reoperation-0.8%, and death-0. There were no differences between groups with respect to reoperation (P = 0.92), reintubation (P = 0.94), or mortality (P = 0.49). The mean per-patient cost was significantly higher (P = 0.009) in those who received PACU x-rays, $1031.76 ± 948.67, versus those in the control group, $700.26 ± 634.48. Mean length of stay was significantly longer in those who had PACU x-rays (P = 0.01).

CONCLUSION

Although there were no differences in reoperation, reintubation, or mortality, there was a significantly higher cost for care and hospitalization in those who received PACU x-rays. Further studies are warranted to validate the results of the presented study.Level of Evidence: 3.

The Utility of In-Hospital Postoperative Radiographs Following Surgical Treatment of Traumatic Thoracolumbar Injuries

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

The objective of this study was to assess the utility of routine in-hospital postoperative radiographs for identifying hardware failure following surgical treatment of traumatic thoracolumbar (TL) injuries.

BACKGROUND

Postoperative radiographs following spine surgery are considered standard of care despite a lack of evidence supporting their utility. Previous studies have concluded that postoperative radiographs following lumbar fusion for degenerative conditions have limited clinical value.

MATERIALS AND METHODS

A retrospective chart review was performed on patients who underwent surgical treatment of traumatic TL injuries between December 2006 and October 2015 at a level I trauma center. Before discharge, postoperative upright anteroposterior and lateral radiographs were obtained and reviewed by 1 surgeon and 1 radiologist as per protocol. Patients who subsequently underwent revision surgery during their initial hospital stay were identified. These patients were further analyzed to identify the indications for surgery and determine if the results of the radiographs obtained led to the subsequent revision surgery.

RESULTS

A total of 463 patients were identified who underwent surgical treatment following TL trauma. The rate of revision surgery during the initial hospitalization was 1.3% (6/463). Three patients underwent revision surgery due to worsening neurological status. One patient underwent reoperation because of advance imaging obtained for abdominal trauma. Two patients underwent revision surgery due to abnormal findings on postoperative radiographs. The overall sensitivity and specificity of routine postoperative radiographs was 33.3% and 100%, respectively.

CONCLUSIONS

In the absence of new clinical signs and symptoms, obtaining routine in-hospital postoperative radiographs following surgical treatment of TL injuries provides minimal value. Clinical assessment should help determine if additional imaging is indicated for the patient. Avoiding unnecessary inpatient tests such as routine postoperative radiograph may offer multitude of benefits including lowering patient radiation exposure, reducing health care costs and better allocation of hospital resources.

LEVEL OF EVIDENCE

Level III.

Utility of Routine Postoperative Radiographs After Fixation of Lower Extremity Fractures

INTRODUCTION

The goal of this study was to investigate the clinical utility of radiographs at all time points after internal fixation of lower extremity fractures.

METHODS

A retrospective chart review was conducted at a level I trauma center. Four hundred eighty-five patients with 586 fractures of the femur, tibia, and ankle were included. Data were analyzed to investigate the effect of radiographs on changes in management at all postoperative time points for each fracture type.

RESULTS

Each fracture received, on average, 4.8 radiographs after fixation for a total cost of $938,469. The management of 31% (179 of 586) of fractures deviated from the expected postoperative course. Of the 179 fractures with a deviation, 93 (31%) resulted from radiographic findings alone and occurred (1) in the immediate postoperative period (2%) and (2) in the period from consideration of advancement to full weight bearing up until confirmation of fracture union (98%). Notable cost savings can be realized by using the findings to eliminate nonclinically indicated imaging at both the institutional and national levels.

CONCLUSION

Routine radiographs in isolation contribute to changes in management (1) in the immediate postoperative period in select cases and (2) during the period when advancement to full weight bearing is being considered up until clinical fracture union.

LEVEL OF EVIDENCE

Level III.

Utility of postoperative radiography in routine primary total shoulder arthroplasty

BACKGROUND

The medical relevance and cost-benefit of routine radiographs after primary anatomic total shoulder arthroplasty (TSA) up to a year postoperatively are unknown. This study was performed to assess the medical relevance and cost-benefit of radiography after TSA during the first postoperative year.

METHODS

During the period 2010 to 2015, 160 consecutive patients undergoing anatomic TSA by a single fellowship-trained surgeon had radiographs obtained at 2 weeks, 6 weeks, 4 months, and 1 year postoperatively. Radiographs and clinic notes were assessed to determine if a change in postoperative care happened because of radiographic findings, including postoperative fracture, hardware complication, or any concerning radiographic feature. Cost data and amount billed were obtained.

RESULTS

Patients underwent radiography at 1.8 ± 0.2 weeks, 6.5 ± 1.2 weeks, 14.9 ± 2.9 weeks, and 46.8 ± 19.5 weeks postoperatively. Findings on the radiologist's reading were normal/unremarkable for 100.0%, 96.8%, 95.9%, and 95.2%, respectively, at each visit. Results were documented in the note for 92.5%, 97.4%, 98.0%, and 92.4%, respectively, at each visit. Review of the radiographs yielded no change in management based on these parameters. The amount billed for radiographs was $284,281 ($1776.76 per patient).

CONCLUSIONS

A lack of clinically meaningful impact from routine postoperative radiography does not justify the per-patient expense, as routine imaging did not cause a change in postoperative management. The available data suggest that routine radiographs after primary anatomic TSA may be unnecessary or perhaps the described frequency in which radiographs are obtained is in excess.

Limited utility of routine early postoperative radiography after primary ACL reconstruction

BACKGROUND

Given the overall success of anterior cruciate ligament (ACL) reconstruction and the infrequent occurrence of complications detectable on radiographs, the clinical utility and cost-effectiveness of routine radiographs in the early postoperative setting is questionable.

METHODS

Nine hundred thirty-three consecutive adult patients undergoing uncomplicated ACL reconstruction at a single institution were retrospectively reviewed to determine whether a postoperative knee radiograph was obtained within the first three months postoperatively. Images, reports and clinical notes were reviewed to determine if any clinical management change occurred due to x-ray findings. Radiograph charges, including imaging, technical and professional charges were calculated.

RESULTS

Five hundred ninety-nine of 933 primary ACL reconstruction patients (64.8%) had postoperative knee radiography at an average of 6.3±3.5 weeks postoperatively. A musculoskeletal radiologist read 97.7% of x-rays as normal. In the associated visit note, 70.3% of x-ray results were documented. Only 14.1% of patients with a postoperative x-ray had subsequent imaging. There were no significant management changes based on the routine postoperative radiographs using the defined criteria. A total of $336,683 ($562 per patient) was billed to patients for postoperative radiographs.

CONCLUSIONS

Routine early postoperative radiography after primary ACL reconstruction is of questionable utility. The significant per-patient expense is not balanced by the low yield of clinically meaningful data, as nearly all radiographs in the present series were normal and none resulted in significant changes in postoperative clinical management. These results suggest that routine radiographs after uncomplicated ACL reconstruction may be unnecessary although larger, multicenter studies are necessary to confirm these findings.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Utility of Routine Outpatient Cervical Spine Imaging Following Anterior Cervical Corpectomy and Fusion

Background: Construct failure is an uncommon but well-recognized complication following anterior cervical corpectomy and fusion (ACCF). In order to screen for these complications, many centers routinely image patients at outpatient visits following surgery. There remains, however, little data on the utility of such imaging.

Methods: The electronic medical record of all patients undergoing anterior cervical corpectomy and fusion at Dartmouth-Hitchcock Medical Center between 2004 and 2009 were reviewed. All patients had routine cervical spine radiographs performed perioperatively. Follow-up visits up to two years postoperatively were analyzed. 

Results: Sixty-five patients (mean age 52.2) underwent surgery during the time period. Eighteen patients were female. Forty patients had surgery performed for spondylosis, 20 for trauma, three for tumor, and two for infection. Forty-three patients underwent one-level corpectomy, 20 underwent two-level corpectomy, and two underwent three-level corpectomy, using an allograft, autograft, or both. Sixty-two of the fusions were instrumented using a plate and 13 had posterior augmentation. Fifty-seven patients had follow-up with imaging at four to 12 weeks following surgery, 54 with plain radiographs, two with CT scans, and one with an MRI scan. Unexpected findings were noted in six cases. One of those patients, found to have asymptomatic recurrent kyphosis following a two-level corpectomy, had repeat surgery because of those findings. Only one further patient was found to have abnormal imaging up to two years, and this patient required no further intervention.

Conclusions: Routine imaging after ACCF can demonstrate asymptomatic occurrences of clinically significant instrument failure. In 43 consecutive single-level ACCF however, routine imaging did not change management, even when an abnormality was discovered. This may suggest a limited role for routine imaging after ACCF in longer constructs involving multiple levels.

Utility of Computed Tomography following Anterior Cervical Diskectomy and Fusion

Study Design Retrospective case series. Objective To assess the utility of postoperative computed tomography (CT) following anterior cervical diskectomy and fusion (ACDF) and to determine the clinical circumstances most likely to lead to an abnormal CT scan. Methods Patients who underwent ACDF at a tertiary center over a span of 5 years were investigated. Only patients who had a minimum of 6 months' postoperative follow-up and a CT within 2 years after the surgery were included in the study group. All the postoperative notes were reviewed to determine indications for the CT, abnormalities identified, and whether the scan led to an alteration in the treatment course. Results The charts of 690 patients who underwent ACDF were reviewed. Of the 690 patients, 45 (7%) had postoperative CTs. These patients accounted for 53 postoperative CT scans, 45 (85%) of which were taken for patients who expressed persistent postoperative symptoms and/or had abnormal imaging. There were no indications for 8 (15%) of the CTs. Patients who had a CT for persistent symptoms and/or abnormal preliminary imaging were significantly more likely to have an abnormal CT (p = 0.03) and/or an alteration in treatment course (p = 0.04) compared with those with no symptomatic or radiologic indication for CT. Conclusions CT is associated with minimal utility regarding the alteration of treatment course when employed in asymptomatic patients. Postoperative CT should be ordered solely for symptomatic patients or those with other abnormal preliminary imaging. Judicious use of postoperative CT will limit the radiation exposure and cost.

Utility of Postoperative Radiographs for Pediatric Scoliosis: Association Between History and Physical Examination Findings and Radiographic Findings

BACKGROUND

Postoperative radiographs are routinely obtained following surgery for the correction of scoliosis in pediatric patients. The purpose of this study was to comprehensively evaluate the utility of obtaining routine postoperative radiographs in the management of these patients.

METHODS

A total of 1969 clinic notes and corresponding radiographs regarding 451 consecutive patients with scoliosis (age range, ten to eighteen years) who had surgical correction over a ten-year period at a single institution were retrospectively reviewed. Curve etiology, preoperative curve characteristics, and surgical procedures performed were recorded. All postoperative clinic notes and radiographs were reviewed for abnormalities and changes in treatment course. It was then determined whether clinical signs and symptoms and/or abnormal radiographic findings led to a change in treatment course, which was defined as a therapeutic intervention or further diagnostic testing.

RESULTS

Of the 451 patients in this study (average age [and standard deviation], 14.7 ± 2.4 years), 72.5% had adolescent idiopathic scoliosis, 23.3% had neuromuscular scoliosis, and 4.2% had other underlying causes of scoliosis. A change in treatment course occurred in the cases of forty-two patients, all of whom had symptomatic findings on postoperative history and physical examination and only fifteen of whom had supportive abnormal findings on postoperative radiographs. Curve etiology and surgical procedures performed had no impact on radiographic utility. A significant increase in utility was seen for radiographs obtained at visits one year or more following surgery compared with those obtained at visits less than one year following surgery (1.7% compared with 0.3%, p = 0.001). The overall sensitivity, specificity, positive predictive value, and negative predictive value of routine postoperative radiographs in guiding treatment course were 35.7%, 98.1%, 28.8%, and 98.6%, respectively.

CONCLUSIONS

Routine radiographs provide low utility in guiding the course of treatment for asymptomatic pediatric patients following surgery for scoliosis. The results of this study suggest that patient or caregiver complaints, comorbidities, and clinical suspicion should be considered before obtaining radiographs at postoperative visits in order to minimize radiation exposure in pediatric patients and reduce medical costs without compromising care.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Methods of evaluating lumbar and cervical fusion

Introduced in 1911, spinal fusion is now widely used to stabilize the cervical, thoracic, and lumbar spine. Despite advancements in surgical techniques, including the use of instrumentation and optimizing bone graft options, pseudarthrosis remains one of the most significant causes of clinical failure following attempted fusion. Diagnosis of this common complication is based on a focused clinical assessment and imaging studies. Pseudarthrosis classically presents with the onset of or return of axial or radicular symptoms during the first postoperative year. However, this diagnosis is complicated because other diagnoses can mimic these symptoms (such as infection or adjacent segment degeneration) and because many cases of pseudarthrosis are asymptomatic. Computed tomography and assessment of motion on flexion/extension radiographs are the two preferred imaging modalities for establishing the diagnosis of pseudarthrosis. The purpose of this article was to review the current status of imaging and clinical practices for assessing fusion following spinal arthrodesis.

Utility of postoperative radiographs after anterior lumbar interbody fusion with or without posterior instrumentation

STUDY DESIGN

Retrospective clinical and radiographical review.

OBJECTIVE

To evaluate the utility of plain radiographical surveillance after anterior lumbar interbody fusion and determine to what extent radiographical findings affect postoperative decision making.

SUMMARY OF BACKGROUND DATA

Postoperative radiographical surveillance is a ubiquitous practice among spine surgeons, which lacks evidence and has received growing attention in an environment of increasing health care cost and receding resources. Lumbar interbody fusions are being performed with increasing frequency from numerous approaches; nonetheless, there are no evidence-based guidelines for postoperative radiographical evaluation of patients after these procedures.

METHODS

One hundred forty-six consecutive patients who underwent anterior lumbar interbody fusion with or without short segment posterior fusion from 2008 to 2011 were reviewed. Exclusion criteria were less than 6 months of follow-up, prior surgery, hybrid constructs with disc arthroplasty, and concurrent posterior fusion of greater than 3 levels. Three hundred fifty-nine radiographical series and 330 clinic notes of the included 67 patients were reviewed. Radiographs were evaluated for abnormalities and clinic notes reviewed for any changes in clinical management by multiple reviewers. Interobserver reliability, sensitivity, specificity, and positive and negative predictive values were calculated.

RESULTS

There was no single instance of a change in treatment course based on radiographical findings alone in any of the 330 clinic visits of the 67 included patients during an average 15.8-month postoperative follow-up period. Thirty-four of the 67 patients (51%) had some change in their management on the basis of their clinical symptoms and/or examination. Interobserver agreement for change in management was 0.96 (κ = 0.918). Sensitivity (6%), specificity (97%), positive predictive value (67%), and negative predictive value (50%) were calculated.

CONCLUSION

Routine postoperative radiographical surveillance has minimal value for asymptomatic patients after anterior lumbar interbody fusion with or without posterior fusion. Obtaining a limited number of postoperative films of these patients in the absence of clinical symptoms or risk factors could significantly reduce health care costs and unnecessary radiation exposure.