Jason O. Toy

General Compared with Spinal Anesthesia for Total Hip Arthroplasty

BACKGROUND Total hip arthroplasty may be performed under general or spinal anesthesia. The purpose of the current study was to compare perioperative outcomes between anesthetic types for patients undergoing primary elective total hip arthroplasty. METHODS Patients who had undergone primary elective total hip arthroplasty from 2010 to 2012 were identified from the American College of Surgeons National Surgical Quality Improvement Program database. Operating room times, length of stay, thirty-day adverse events, and readmission were compared between patients who had received general anesthesia and those who had received spinal anesthesia. Propensity-adjusted multivariate analysis was used to control for selection bias and baseline patient characteristics. RESULTS A total of 20,936 patients who had undergone total hip arthroplasty met inclusion criteria for this study. Of these, 12,752 patients (60.9%) had received general anesthesia and 8184 patients (39.1%) had received spinal anesthesia. On propensity-adjusted multivariate analyses, general anesthesia for total hip arthroplasty was associated with increased operative time (+12 minutes [95% confidence interval, +11 to +13 minutes]; p < 0.001) and postoperative room time (+5 minutes [95% confidence interval, +4 to +6 minutes]; p < 0.001). General anesthesia was also associated with the occurrence of any adverse event (odds ratio, 1.31 [95% confidence interval, 1.23 to 1.41]; p < 0.001), prolonged postoperative ventilator use (odds ratio, 5.81 [95% confidence interval, 1.35 to 25.06]; p = 0.018), unplanned intubation (odds ratio, 2.17 [95% confidence interval, 1.11 to 4.29]; p = 0.024), stroke (odds ratio, 2.51 [95% confidence interval, 1.02 to 6.20]; p = 0.046), cardiac arrest (odds ratio, 5.04 [95% confidence interval, 1.15 to 22.07]; p = 0.032), any minor adverse event (odds ratio, 1.35 [95% confidence interval, 1.25 to 1.45]; p = 0.001), and blood transfusion (odds ratio, 1.34 [95% confidence interval, 1.25 to 1.45]; p < 0.001). General anesthesia was not associated with any difference in preoperative room time, postoperative length of stay, or readmission. CONCLUSIONS General anesthesia was associated with an increased rate of adverse events and mildly increased operating room times.

Morbidity, mortality, and readmission after vertebral augmentation: analysis of 850 patients from the American College of Surgeons National Surgical Quality Improvement Program database.

Study Design. Retrospective cohort study. Objective. To identify risk factors for poor short-term outcomes after vertebral augmentation procedures. Summary of Background Data. Vertebral compression fractures are the most common fractures of osteoporosis and are frequently treated with vertebroplasty or kyphoplasty. There is a shortage of information about risk factors for short-term, general health outcomes after vertebral augmentation in the literature. Methods. Patients older than 65 years who underwent vertebroplasty or kyphoplasty in 2011 and 2012 were identified from the American College of Surgeons National Surgical Quality Improvement Program database. Patient characteristics were tested for association with 30-day adverse events, mortality, and readmission using bivariate and multivariate analyses. Results. A total of 850 patients met inclusion criteria. The average age was 78.9 ± 11.7 years (mean ± standard deviation) and females made up 70.8% of the cohort. Of these patients, 9.5% had any adverse event (AAE), and 6.6% had a serious adverse event (SAE). Death occurred in 1.5% of patients, and 10.8% were readmitted within the first 30 postoperative days. On multivariate analysis, AAE and SAE were both significantly associated with American Society of Anesthesiologists class 4 (AAE: odds ratio [OR] = 2.7, P = 0.013; SAE: OR = 2.5, P = 0.040) and inpatient status before procedure (AAE: OR = 2.7, P < 0.001, SAE: OR = 2.4, P = 0.003). Increased postoperative mortality rate was associated with American Society of Anesthesiologists class 4 (OR = 6.4, P = 0.024) and the use of nongeneral anesthesia (OR = 4.0, P = 0.022). Readmission was associated with history of pulmonary disease (OR = 2.0, P = 0.005) and inpatient status before procedure (OR = 1.9, P = 0.005). Conclusion. Adverse general health outcomes were relatively common, and the factors identified in the earlier text associated with patient outcomes after vertebral augmentation may be useful for preoperative discussions and counseling. Level of Evidence: 3

Anterior Ankle Impingement: Diagnosis and Treatment

Anterior ankle impingement is a common clinical condition characterized by chronic anterior ankle pain that is exacerbated on dorsiflexion. Additional symptoms include instability; limited ankle motion; and pain with squatting, sprinting, stair climbing, and hill climbing. Diagnosis is typically confirmed with plain radiographs. Nonsurgical management includes physical therapy, strengthening exercises, activity modification, bracing, and anti-inflammatory medication. Although arthroscopic treatment is sufficient in some patients, most require an open approach to address related pathology. We advocate aggressive range of motion as well as weight bearing postoperatively. Further study is needed to confirm current understanding of anterior ankle impingement and to better define treatment options and prevention strategies.

Is lumbar stenosis associated with thoracic stenosis? A study of 1,072 human cadaveric specimens.

BACKGROUND CONTEXT Tandem stenosis of the cervical and lumbar spine is known to occur in 5% to 25% of individuals with symptomatic neural compression in one region. However, the prevalence of concurrent lumbar and thoracic stenosis is not known. Whether this relationship is because of an increased risk of degenerative diseases in these individuals or because of the tandem presence of stenosis in lumbar and thoracic canal is unknown. PURPOSE To determine the prevalence of concurrent lumbar and thoracic stenosis, and whether the presence of stenosis in the lumbar spine is associated with stenosis in the thoracic spine. STUDY DESIGN A morphoanatomic study of lumbar and thoracic cadaveric spines. METHODS One thousand seventy-two adult skeletal specimens from the Hamann-Todd Collection in the Cleveland Museum of Natural History were selected. Canal area at each level was also calculated using a geometric formula. A standard distribution for each level was created, and values that were 2 standard deviations below mean were considered as being stenotic. Linear regression analysis was used to determine the association between the additive canal areas at all levels in the lumbar and thoracic spine and between the number of stenotic lumbar and thoracic levels. Logistic regression was used to calculate the odds ratios (OR) for concurrent lumbar and thoracic stenosis. RESULTS The prevalence of concurrent lumbar and thoracic stenosis is 1.42%. A positive association was found between the additive areas of all lumbar and thoracic levels (p<.01). No association, however, was found between the number of stenotic lumbar and thoracic levels (p=.7). Log regression demonstrated no significant association (OR <1) between stenosis in the lumbar and thoracic spine. CONCLUSIONS The stenosis of the lumbar spine is not associated with the thoracic stenosis. Thus, stenosis in lumbar and thoracic levels does not seem to be contributed by tandem stenosis.

Most 30-day Readmissions After Anterior Cervical Discectomy and Fusion are Not Due to Surgical Site-Related Issues: An Analysis of 17,088 Patients.

Study Design. A retrospective study of patients undergoing anterior cervical discectomy and fusion (ACDF) in the prospective National Surgical Quality Improvement Program (NSQIP) database. Objective. To determine the most common reasons for readmission within 30 days after elective ACDF. Summary of Background Data. ACDF is a commonly performed surgery that is safe and effective for treating a variety of cervical spine pathologies. With new quality-based reimbursements tied to readmissions within 30 days of discharge, better understanding of the causes of readmissions is, however, needed. Methods. Patients undergoing ACDF in the NSQIP database from 2012 to 2014 were reviewed. The overall rate of readmission and documented reasons for readmission were collected. Multivariate regression was then used to determine risk factors for readmissions. Results. A total of 17,088 patients undergoing elective ACDF were identified. There were 545 (3.2%) readmissions within 30 postoperative days. Of the readmitted patients, 293 (53.8%) were readmitted for nonsurgical site-related reasons, with neuropsychiatric (n = 44), cardiovascular (n = 39), and pneumonia (n = 37) being the most common reasons. A total of 184 patients (33.8%) were readmitted for surgical site-related reasons, with surgical site infection (n = 42), hemorrhage/hematoma (n = 42), and dysphagia (n = 32) being the most common reasons. A total of 84 patients (15.6%) had undocumented reasons for readmission. In multivariate analysis, only older age and higher American Society of Anesthesiologists class were independently associated with readmissions. Conclusion. Most readmissions after ACDF were due to nonsurgical site-related reasons, suggesting the importance of careful patient selection, aggressive preoperative medical optimization, and adequate postoperative management. Level of Evidence: 3

Undertapping of Lumbar Pedicle Screws Can Result in Tapping With a Pitch That Differs From That of the Screw, Which Decreases Screw Pullout Force.

Study Design. Survey of spine surgeons and biomechanical comparison of screw pullout forces. Objective. To investigate what may be a suboptimal practice regularly occurring in spine surgery. Summary of Background Data. In order for a tap to function in its intended manner, the pitch of the tap should be the same as the pitch of the screw. Undertapping has been shown to increase the pullout force of pedicle screws compared with line-to-line tapping. However, given the way current commercial lumbar pedicle screw systems are designed, undertapping may result in a tap being used that has a different pitch from that of the screw (incongruent pitch). Methods. A survey asked participants questions to estimate the proportion of cases each participant performed in the prior year using various hole preparation techniques. Participant responses were interpreted in the context of manufacturing specifications of specific instrumentation systems. Screw pullout forces were compared between undertapping with incongruent pitch and undertapping with congruent pitch using 0.16 g/cm3 polyurethane foam block and 6.5-mm screws. Results. Of the 3679 cases in which participants reported tapping, participants reported line-to-line tapping in 209 cases (5%), undertapping with incongruent pitch in 1156 cases (32%), and undertapping with congruent pitch in 2314 cases (63%). The mean pullout force for undertapping with incongruent pitch was 56 N (8%) less than the mean pullout force for undertapping with congruent pitch. This is equivalent to 13 lb. Conclusion. This study estimates that for about 1 out of every 3 surgical cases with tapping of lumbar pedicle screws in the United States, hole preparation is being performed by undertapping with incongruent pitch. This study also shows that undertapping with incongruent pitch results in a decrease in pullout force by 8% compared with undertapping with congruent pitch. Steps should be taken to correct this suboptimal practice. Level of Evidence: 3

Use of an operating microscope during spine surgery is associated with minor increases in operating room times and no increased risk of infection

Study Design. Retrospective database review. Objective. To evaluate whether microscope use during spine procedures is associated with increased operating room times or increased risk of infection. Summary of Background Data. Operating microscopes are commonly used in spine procedures. It is debated whether the use of an operating microscope increases operating room time or confers increased risk of infection. Methods. The American College of Surgeons National Surgical Quality Improvement Program database, which includes data from more than 370 participating hospitals, was used to identify patients undergoing elective spinal procedures with and without the use of an operating microscope for the years 2011 and 2012. Bivariate and multivariate linear regressions were used to test the association between microscope use and operating room times. Bivariate and multivariate logistic regressions were similarly conducted to test the association between microscope use and infection occurrence within 30 days of surgery. Results. A total of 23,670 elective spine procedures were identified, of which 2226 (9.4%) used an operating microscope. The average patient age was 55.1 ± 14.4 years. The average operative time (incision to closure) was 125.7 ± 82.0 minutes. Microscope use was associated with minor increases in preoperative room time (+2.9 min, P = 0.013), operative time (+13.2 min, P < 0.001), and total room time (+18.6 min, P < 0.001) on multivariate analysis. A total of 328 (1.4%) patients had an infection within 30 days of surgery. Multivariate analysis revealed no significant difference between the microscope and nonmicroscope groups for occurrence of any infection, superficial surgical site infection, deep surgical site infection, organ space infection, or sepsis/septic shock, regardless of surgery type. Conclusion. We did not find operating room times or infection risk to be significant deterrents for use of an operating microscope during spine surgery. Level of Evidence: 3

Lumbar Disc Arthroplasty

Lumbar total disc replacement (L-TDR) is a motion-preserving surgical treatment for patients with degenerative disc disease (DDD) and debilitating mechanical low back pain (LBP) refractory to nonsurgical management. It represents an alternative surgical intervention to lumbar arthrodesis with theoretical advantages including the preservation of physiologic motion, which may lead to less axial back pain as well as to decreased rates of adjacent segment disease and reoperation. Secondary advantages include potential shorter recovery times. The ideal candidate for the L-TDR is a relatively young patient with normal neurologic exam suffering mechanical LBP that has failed at least 6 months of nonoperative management with imaging revealing focal DDD with little or no facet disease. Two multicenter, randomized, controlled investigational device exemption (IDE) trials in the United States comparing the Charite and ProDisc-L artificial discs versus lumbar fusion have demonstrated non-inferiority for safety and efficacy in relief of back pain up to 2 years following surgery. A third lumbar TDR device, Activ-L, received FDA approval after completing an IDE study comparing that artificial disc to both the Charite and ProDisc-L discs. Given the controversy surrounding the surgical treatment of DDD in general, many insurance carriers do not provide coverage for fusion or L-TDR which continues to affect the utilization of lumbar arthroplasty devices. A representative case of L-TDR is presented, as well as general patient selection, contraindications, and surgical technique including technical pearls with potential complications and avoidance strategies.

Bilateral Pars Defects at the L4 Vertebra Result in Increased Degeneration When Compared With Those at L5: An Anatomic Study

BackgroundCadaveric studies have examined disc degeneration at the L4-L5 and L5-S1 motion segments; however, we are not aware of another study that has examined the relationship between bilateral spondylolysis and its effect on degenerative disc disease at those levels. This may have been overlooked by researchers owing to the majority of spondylolysis occurring at the L5 vertebra.Questions/purposesUsing osteologic specimens from a collection that included individuals who died in one city in the USA between 1893 and 1938, we asked: (1) do specimens with bilateral spondylolysis (bilateral pars defects) have increased levels of disc degeneration, at their respective motion segments, when compared with matched controls without spondylolysis, and (2) is the finding of a bilateral pars defect associated with more severe arthritis at L4-L5 than at L5-S1?MethodsAn observational study was performed on 665 skeletal lumbar spines from the Hamann-Todd Osteologic Collection at the Cleveland Museum of Natural History (Cleveland, OH, USA). The specimens included 534 males and 131 females ranging from 17 to 87 years old, with a nearly bell-shaped distribution of ages for males and a larger proportion of younger ages in the female specimens. Of those with spondylolysis, 81 had a defect at L5 and 14 had a defect at L4. The gross specimens were examined subjectively for evidence of arthrosis. At the time of examination, specific attention was not paid to the coexisting presence or absence of spondylolysis nor was the examiner blinded to the age of the specimens. Disc degeneration was measured by the classification of Eubanks et al., a modified version of the Kettler and Wilke classification. Linear regression was performed to derive a formula that would predict the amount of disc degeneration at L4-L5 and L5-S1 for the normal control population given a specimen’s age, sex, and race. We then used this formula to evaluate the difference in disc degeneration at the corresponding level of the pars defect that is greater than the predicted amount for a control without spondylolysis. This allowed us to conclude that any significant differences found between the L4-L5 and L5-S1 cohorts were attributable to factors not simply inherent to their functional position in the spine of an individual without a bilateral pars defect.ResultsL4 spondylolysis and L5 spondylolysis showed greater amounts of degeneration compared with that of matched controls (L4 controls: mean = 1.52, SD = 0.74; L4 spondylolysis: mean = 3.21, SD = 0.87; p < 0.001; L5 controls: mean = 0.97, SD = 0.48; L5 spondylolysis: mean = 2.06, SD = 0.98; p < 0.001). When we controlled for the expected amount of degenerative disc disease at each level in controls, the observed degeneration was more severe at L4-L5 than at L5-S1 (p = 0.008, R-squared = 18.6).ConclusionsL4-L5 and L5-S1 bilateral spondylolysis groups had increased presence of degenerative disc disease compared with those without bilateral spondylolysis. For the same degree of spondylolysis, the observed amount of disc degeneration was greater at the L4-5 motion segment compared with L5-S1.Clinical RelevanceAlthough not as common as the spondylolysis at L5-S1, we believe that our findings support that patients with L4-L5 spondylolysis can expect a greater degree of degenerative disc disease and increasing clinical symptoms. Multiple factors in the sacropelvic geometry of an individual, facet morphologic features at L4-L5, and the absence of the iliolumbar ligament at this level are possible contributing factors to the findings of this study.