Evolution of lumbar degenerative spondylolisthesis with key radiographic features.

Spondylolisthesis is a common finding in middle-aged and older adults with back pain. The pathophysiology of degenerative spondylolisthesis is a subject of controversy regarding not only its etiology but also the mechanisms of its progression. It is theorized that degeneration of the facets and discs can lead to segmental instability, leading to displacement over time. Kirkaldy-Willis divided degenerative spondylolisthesis into three phases: dysfunction, instability, and finally, restabilization. There is a paucity of literature on the unification of the radiological hallmarks seen in spondylolisthesis within these phases. The radiographic features include (1) facet morphology/arthropathy, (2) facet effusion, (3) facet vacuum, (4) synovial cyst, (5) interspinous ligament bursitis, and (6) vacuum disc as markers of dysfunction, instability, and/or restabilization. We discuss these features, which can be seen on X-ray, CT, and MRI, with the intention of establishing a timeline upon which they present clinically. Spondylolisthesis is initiated as either degeneration of the intervertebral disc or facet joints. Early degeneration can be seen as facet vacuum without considerable arthropathy. As the vertebral segment becomes increasingly dynamic, fluid accumulates within the facet joint space. Further degeneration will lead to the advancement of facet arthropathy, degenerative disc disease, and posterior ligamentous complex pathology. Facet effusion can eventually be replaced with a vacuum in severe facet osteoarthritis. Intervertebral disc vacuum continues to accumulate with further cleft formation and degeneration. Ultimately, autofusion of the vertebra at the facets and endplates can be observed. With this review, we hope to increase awareness of these radiographical markers and their timeline, thus placing them within the framework of the currently accepted model of degenerative spondylolisthesis, to help guide future research and to help refine management guidelines.

Prospective, randomized controlled multicenter study of posterior lumbar facet arthroplasty for the treatment of spondylolisthesis.

OBJECTIVE: The purpose of this study was to evaluate the safety and efficacy of a posterior facet replacement device, the Total Posterior Spine (TOPS) System, for the treatment of one-level symptomatic lumbar stenosis with grade I degenerative spondylolisthesis. Posterior lumbar arthroplasty with facet replacement is a motion-preserving alternative to lumbar decompression and fusion. The authors report the preliminary results from the TOPS FDA investigational device exemption (IDE) trial. METHODS: The study was a prospective, randomized controlled FDA IDE trial comparing the investigational TOPS device with transforaminal lumbar interbody fusion (TLIF) and pedicle screw fixation. The minimum follow-up duration was 24 months. Validated patient-reported outcome measures included the Oswestry Disability Index (ODI) and visual analog scale (VAS) for back and leg pain. The primary outcome was a composite measure of clinical success: 1) no reoperations, 2) no device breakage, 3) ODI reduction of ≥ 15 points, and 4) no new or worsening neurological deficit. Patients were considered a clinical success only if they met all four measures. Radiographic assessments were made by an independent core laboratory. RESULTS: A total of 249 patients were evaluated (n = 170 in the TOPS group and n = 79 in the TLIF group). There were no statistically significant differences between implanted levels (L4-5: TOPS, 95% and TLIF, 95%) or blood loss. The overall composite measure for clinical success was statistically significantly higher in the TOPS group (85%) compared with the TLIF group (64%) (p = 0.0138). The percentage of patients reporting a minimum 15-point improvement in ODI showed a statistically significant difference (p = 0.037) favoring TOPS (93%) over TLIF (81%). There was no statistically significant difference between groups in the percentage of patients reporting a minimum 20-point improvement on VAS back pain (TOPS, 87%; TLIF, 64%) and leg pain (TOPS, 90%; TLIF, 88%) scores. The rate of surgical reintervention for facet replacement in the TOPS group (5.9%) was lower than the TLIF group (8.8%). The TOPS cohort demonstrated maintenance of flexion/extension range of motion from preoperatively (3.85°) to 24 months (3.86°). CONCLUSIONS: This study demonstrates that posterior lumbar decompression and dynamic stabilization with the TOPS device is safe and efficacious in the treatment of lumbar stenosis with degenerative spondylolisthesis. Additionally, decompression and dynamic stabilization with the TOPS device maintains segmental motion.

A Retrospective Analysis of the L3-L4 Disc and Spinopelvic Parameters on Outcomes in Thoracolumbar Fusion: Was Art Steffee Right?

OBJECTIVE: To determine whether the L3-L4 disc angle may be a surrogate marker for global lumbar alignment in thoracolumbar fusion surgery and to explore the relationship between radiographic and patient-reported outcomes after thoracolumbar fusion surgery. METHODS: Retrospective chart review was conducted on patients who had undergone a lumbar fusion involving levels from T9 to pelvis. EuroQol-Five Dimension (EQ-5D-3L) scores and adverse events including adjacent-segment disease and degeneration, pseudoarthrosis, proximal junctional kyphosis, stenosis, and reoperation were collected. Pre- and postoperative spinopelvic parameters were measured on weight-bearing radiographs, with the L3-L4 disc angle of novel interest. Univariate logistic and linear regression were performed to assess the associations of radiographic parameters with adverse event incidence and improvement in EQ-5D-3L, respectively. RESULTS: In total, 182 patients met inclusion criteria. Univariable analysis revealed that increased magnitude of L3-L4 disc angle, anterior pelvic tilt, and pelvic incidence measures are associated with increased likelihood of developing postoperative adverse events. Conversely, increased lumbar lordosis demonstrated a decreased incidence of developing a postoperative adverse event. Linear regression showed that radiographic parameters did not significantly correlate with postoperative EQ-5D-3L scores, although scores were significantly improved postfusion in all dimensions except Self-Care (P = 0.51). CONCLUSIONS: L3-L4 disc angle magnitude may serve as a surrogate marker of global lumbar alignment. The degree of spinopelvic alignment did not correlate to improvement in EQ-5D-3L score in the present study, suggesting that quality of life metric change may not be a sensitive or specific marker of postfusion alignment.

What provides a better value for your time? The use of relative value units to compare posterior segmental instrumentation of vertebral segments.

BACKGROUND CONTEXT: Relative value units (RVUs) are a compensation model based on the effort required to provide a procedure or service to a patient. Thus, procedures that are more complex and require greater technical skill and aftercare, such as multilevel spine surgery, should provide greater physician compensation. However, there are limited data comparing RVUs with operative time. Therefore, this study aims to compare mean (1) operative times; (2) RVUs; and (3) RVU/min between posterior segmental instrumentation of 3-6, 7-12, and ≥13 vertebral segments, and to perform annual cost difference analysis. METHODS: A total of 437 patients who underwent instrumentation of 3-6 segments (Cohort 1, current procedural terminology [CPT] code: 22842), 67 patients who had instrumentation of 7-12 segments (Cohort 2, CPT code: 22843), and 16 patients who had instrumentation of ≥13 segments (Cohort 3, CPT code: 22844) were identified from the National Surgical Quality Improvement Program (NSQIP) database. Mean operative times, RVUs, and RVU/min, as well as an annualized cost difference analysis, were calculated and compared using Student t test. This study received no funding from any party or entity. RESULTS: Cohort 1 had shorter mean operative times than Cohorts 2 and 3 (217 minutes vs. 325 minutes vs. 426 minutes, p<.05). Cohort 1 had a lower mean RVU than Cohorts 2 and 3 (12.6 vs. 13.4 vs. 16.4). Cohort 1 had a greater RVU/min than Cohorts 2 and 3 (0.08 vs. 0.05, p<.05; vs. 0.08 vs. 0.05, p>.05). A $112,432.12 annualized cost difference between Cohorts 1 and 2, a $176,744.76 difference between Cohorts 1 and 3, and a $64,312.55 difference between Cohorts 2 and 3 were calculated. CONCLUSION: The RVU/min takes into account not just the value provided but also the operative times required for highly complex cases. The RVU/min for fewer vertebral level instrumentation being greater (0.08 vs. 0.05), as well as the $177,000 annualized cost difference, indicates that compensation is not proportional to the added time, effort, and skill for more complex cases.

Long-term outcomes of transforaminal lumbar interbody fusion in patients with spinal stenosis and degenerative scoliosis.

BACKGROUND CONTEXT: Patients with spinal deformity may present with complaints related to either the deformity itself or the manifestations of the coexisting spinal stenosis. There are reports of successful management of lumbar pathology in the absence of global sagittal or coronal imbalance, with limited decompression and fusion, addressing only the symptomatic segment. PURPOSE: Our study examined the long-term outcomes of transforaminal lumbar interbody fusion (TLIF), a less extensive procedure, based on the experience of the senior author over the past 10 years. STUDY DESIGN/SETTING: This was a retrospective study of symptomatic lumbar spinal stenosis and spinal deformity managed by one surgeon at The Cleveland Clinic since 2003. PATIENT SAMPLE: Forty-one patients were included in the study. OUTCOME MEASURES: The present study measures the long-term clinical functional outcomes of these patients through EQ-5D (EuroQol five dimensions questionnaire), PHQ-9 (Patient Health Questionnaire), and PDQ (Pain Disability Questionnaire) forms, along with documented radiographic parameters and Charlson Comorbidity Index (CCI). METHODS: There were no funding or potential conflicts of interest associated biases in the present study. Patients with symptomatic lumbar spinal stenosis with neutral global alignment in the sagittal and coronal planes and symptomatic stenosis at the deformity level were treated by limited fusion and TLIF, and had a follow-up period of at least 5 years. Excluded were patients under 18 years of age, had more than three levels of fusion, and had an active spinal malignancy or recent spinal trauma. The grouping variables were curve magnitude, revision surgeries, and TLIF levels. Clinical outcomes were compared in all the grouping variables. Analysis of variance (ANOVA) and chi-square tests were utilized; p<.05 was considered statistically significant. RESULTS: The average age and follow-up period were 66±10 and 7.5 years, respectively. There was no statistical difference between patients with curves measuring between 10° and 20° and greater than 20° for EQ-5D, PHQ-9, and PDQ. Patients had worse PDQ data with larger curves compared with smaller curves at both 5 years and final follow-up. Although there was no statistical significance between preoperative coronal curve magnitude and revision surgeries, patients with curves greater than 20° had higher rates of revision surgeries (75%; p=.343) in the global lumbar curve deformity group. Although there was no statistical significance for patients who underwent revision surgeries,those patients had low PHQ-9 values at the final follow-up (p=.09). The revision surgery rate was 48% in one-level TLIF and 18% in two-level TLIF. Moderate pain disability scores were noticed for one-level TLIF patients (mean=75) compared with two-level TLIF patients (mean=27) at the final follow-up, and approached statistical significance in this comparison (p=.06). CONCLUSION: Although this topic has a limited audience to spinal deformity surgeons, the prevalence of patients who present with adult spinal deformities has been increasing. Short segment fusion, in the setting of modest spinal deformity, is a reasonable and safe option. Further study on the concept of short segment fusions in the growing patient population is required as more comprehensive fusions do have noted complication rates, and a compromise must be reached between the extent of surgery that is enough to provide pain relief and disability and the degree of surgery that is too much to be tolerated in terms of complication rates.

Comparison of Clinical and Radiographic Outcomes in Patients Receiving Single-Level Transforaminal Lumbar Interbody Fusion With Removal of Unilateral or Bilateral Facet Joints.

STUDY DESIGN: A retrospective cohort study. OBJECTIVE: The objective of this study is to compare the radiographic and clinical outcomes of transforaminal lumbar interbody fusion (TLIF) with bilateral facetectomy (BF) versus unilateral facetectomy (UF). SUMMARY OF BACKGROUND DATA: BF is a surgical technique utilized with the intent of creating a greater degree of segmental lordosis than UF alone. However, the clinical benefits of this technique have not been defined. We seek to determine whether a difference exists between bilateral versus UF during TLIF by utilizing both clinical and radiographic outcome measures. METHODS: The electronic medical records of 57 patients who underwent single-level TLIF with either a UF (n = 28) or BF (n = 29) were reviewed. Clinical outcomes were measured through Patient Health Questionnaire-9 (PHQ-9), Pain Disability Questionnaire (PDQ), EuroQol 5 Dimensions (EQ-5D) Health State, and Quality Adjusted Life Year (QALY). Radiographic parameters including disc height and sagittal balance were measured on plain radiographs at 1 year following operation. RESULTS: All radiographic parameters showed no significant differences between the UF and BF cohorts. Segmental lordosis increased significantly in both cohorts. However, there was no significant difference in the increase of segmental lordosis between cohorts. Overall lumbar lordosis did not increase significantly in either cohort. Perioperative complications were also similar between cohorts. PDQ and EQ-5D scores improved significantly in both cohorts at 1 year postoperatively. The BF cohort showed a significantly greater improvement in both EQ-5D (0.1 ±â€Š0.2 vs. 0.3 ±â€Š0.2, P = 0.01) and PHQ-9 scores (-0.8 ±â€Š4.6 vs. 4.6 ±â€Š5.2, P = 0.03) than the UF cohort. The PDQ score improved over the minimally clinical important difference (MCID) of 26 in only the BF cohort. CONCLUSION: The findings in the present study demonstrate that BF during single-level TLIF improves clinical outcomes to a greater degree than UF without any notable differences in perioperative complications or radiographic measurements. LEVEL OF EVIDENCE: 3.

Management of the Elderly With Vertebral Compression Fractures.

Vertebral compression fractures (VCFs) are the most common type of fracture secondary to osteoporosis. These fractures are associated with significant rates of morbidity and mortality and annual direct medical expenditures of more than $1 billion in the United States. Although many patients will respond favorably to nonsurgical care of their VCF, contemporary natural history data suggest that more than 40% of patients may fail to achieve significant pain relief within 12 months of symptom onset. As a result, percutaneous vertebral augmentation is often used to hasten symptom resolution and return of function. However, controversy regarding the role of kyphoplasty and vertebroplasty in the treatment of symptomatic VCFs exists. The purposes of this review are (1) to outline the epidemiology of VCFs as well as the physical morbidity and economic impact of these injuries, (2) to familiarize the reader with the best available evidence surrounding the operative and nonoperative treatment of VCFs, and (3) to examine the literature pertaining to the cost-effectiveness of surgical management of VCFs with the overarching goal of helping physicians make informed decisions regarding symptomatic VCF treatment.

A steep learning curve is a good thing!

Commentary on: Wang B, Lü G, Patel AA, et al. An evaluation of the learning curve for a complex surgical technique: the full endoscopic interlaminar approach for lumbar disc herniations. Spine J 2011:11:122-130 (in this issue).

Intradural migration of broken IDET catheter causing a radiculopathy.

This case report describes the migration of a broken intradiscal electrothermal therapy catheter tip from the disc space into the thecal sac, leading to a radiculopathy that improved after removing the catheter.

Improving reliability in the classification of fractures of the acetabulum.

BACKGROUND: Plain radiographs of the pelvis are routinely used in the initial assessment of patients with suspected fractures of the acetabulum. It is necessary for orthopaedic resident trainees, emergency physicians as well as orthopaedic surgeons who infrequently treat trauma patients to be able to describe these fracture patterns reliably to traumatologist orthopaedic surgeons who ultimately take over the patient care. Our purpose was two-fold: (1) to determine the reliability of the component parts of the Letournel classification of acetabular fractures involving six anteroposterior (AP) radiographic lines, and (2) to examine whether the addition of oblique radiograph views (Judet views) would improve the reliability. METHODS: Thirty sets of AP and oblique radiographs (Judet views) of the pelvis were selected from a hospital database to represent various types of acetabular fractures. Six reviewers (three orthopaedic trainees and three community orthopaedic surgeons) independently reviewed the radiographs. For each radiograph, the reviewer classified the acetabular fracture according to the Letournel classification. In addition, each reviewer utilized a simplified classification scheme using six radiographic lines on the AP pelvic radiograph. Interobserver reliabilities among reviewers were reported along with the intraclass correlation coefficient (ICC) and kappa values. RESULTS: Agreement for the Letournel classification increased with increasing physician experience (trainees ICC=-0.14 and community surgeons ICC=0.56). Interobserver reliability between trainees and community surgeons improved when the six radiographic lines were used (range kappa=0.09-0.89). The oblique pelvic radiographs (Judet views) did not significantly improve reliability among physicians. CONCLUSIONS: In this study we report the following: (1) the reliability of the Letournel classification improves with level of training, (2) physicians with less experience with acetabular fractures have significantly better agreement in identifying fractures using the six radiographic lines on the AP film than the Letournel classification, and (3) agreement among the reviewers for the AP pelvic radiograph is not improved with additional oblique (Judet) views.