Bydon, Mohamad

OBJECTIVEThe authors sought to assess whether Hounsfield units (HU) increase following teriparatide treatment and to compare HU increases with changes in bone mineral density (BMD) as measured by dual-energy x-ray absorptiometry (DEXA).METHODSA retrospective chart review was performed from 1997 to 2018 across all campuses at our institution. The authors identified patients who had been treated with at least 6 months of teriparatide and compared HU and BMD as measured on DEXA scans before and after treatment.RESULTSFifty-two patients were identified for analysis (46 women and 6 men, average age 67 years) who underwent an average of 20.9 ± 6.5 months of teriparatide therapy. The mean ± standard deviation HU increase throughout the lumbar spine (L1–4) was from 109.8 ± 53 to 133.9 ± 61 HU (+22%, 95% CI 1.2–46, p value = 0.039). Based on DEXA results, lumbar spine BMD increased from 0.85 to 0.93 g/cm2 (+9%, p value = 0.044). Lumbar spine T-scores improved from −2.4 ± 1.5 to −1.7 ± 1.5 (p value = 0.03). Average femoral neck T-scores improved from −2.5 ± 1.1 to −2.3 ± 1.0 (p value = 0.31).CONCLUSIONSTeriparatide treatment increased both HU and BMD on DEXA in the lumbar spine, without a change in femoral BMD. The 22% improvement in HU surpassed the 9% improvement determined with DEXA. These results support some surgeons’ subjective sense that intraoperative bone quality following teriparatide treatment is better than indicated by DEXA results. To the authors’ knowledge, this is the first study demonstrating an increase in HU with teriparatide treatment.

Abstract BACKGROUND There is a paucity of investigation on the impact of spondylolisthesis surgery on back pain-related sexual inactivity. OBJECTIVE To investigate predictors of improved sex life postoperatively by utilizing the prospective Quality Outcomes Database (QOD) registry. METHODS A total of 218 patients who underwent surgery for grade 1 degenerative lumbar spondylolisthesis were included who were sexually active. Sex life was assessed by Oswestry Disability Index item 8 at baseline and 24-mo follow-up. RESULTS Mean age was 58.0 ± 11.0 yr, and 108 (49.5%) patients were women. At baseline, 178 patients (81.7%) had sex life impairment. At 24 mo, 130 patients (73.0% of the 178 impaired) had an improved sex life. Those with improved sex lives noted higher satisfaction with surgery (84.5% vs 64.6% would undergo surgery again, P = .002). In multivariate analyses, lower body mass index (BMI) was associated with improved sex life (OR = 1.14; 95% CI [1.05-1.20]; P < .001). In the younger patients (age < 57 yr), lower BMI remained the sole significant predictor of improvement (OR = 1.12; 95% CI [1.03-1.23]; P = .01). In the older patients (age ≥ 57 yr)—in addition to lower BMI (OR = 1.12; 95% CI [1.02-1.27]; P = .02)—lower American Society of Anesthesiologists (ASA) grades (1 or 2) (OR = 3.7; 95% CI [1.2-12.0]; P = .02) and ≥4 yr of college education (OR = 3.9; 95% CI [1.2-15.1]; P = .03) were predictive of improvement. CONCLUSION Over 80% of patients who present for surgery for degenerative lumbar spondylolisthesis report a negative effect of the disease on sex life. However, most patients (73%) report improvement postoperatively. Sex life improvement was associated with greater satisfaction with surgery. Lower BMI was predictive of improved sex life. In older patients—in addition to lower BMI—lower ASA grade and higher education were predictive of improvement.

Abstract BACKGROUND Postoperative readmissions are a significant driver of variation in bundled care costs associated with cervical spine surgery. OBJECTIVE To determine the factors predicting the cost of readmission episodes following elective anterior cervical discectomy and fusion (ACDF). METHODS We queried the Healthcare Cost and Utilization Project Nationwide Readmissions Database for patients undergoing elective ACDF during 2012 to 2015. Multivariable linear regression was performed to establish the factors associated with the cost of each 30-/90-d readmission episode. RESULTS A total of 139 877 and 113 418 patients met inclusion criteria for the evaluation of 30- and 90-d readmissions, respectively. Among these, the national rates of 30- and 90-d readmission after an elective ACDF were 3% and 6%, respectively. The median cost of a 30- and 90-d readmission episode was $6727 (IQR: $3844-$13 529) and $8507 (IQR: $4567-$17 460), respectively. Relative predictor importance analysis revealed that the number of procedures at index admission (IA), length of stay at IA, and time elapsed between index surgical admission and readmission were the top predictors of both 30- and 90-d readmission costs (all P < .001). Although cervical myelopathy accounted for only 3.6% of all 30-d readmissions, it accounted for the largest share (8%) of 30-d readmission costs. CONCLUSION In this analysis from a national all-payer database, we determined the factors associated with the cost of readmissions following elective ACDF. These results are important in assisting policymakers and payers with a better risk adjustment in bundled care payment systems and for surgeons in implementing readmission cost-reduction efforts.

OBJECTIVE Patient satisfaction with treatment outcome is gaining an increasingly important role in assessing the value of surgical spine care delivery. Nationwide data evaluating the predictors of patient satisfaction in elective cervical spine surgery are lacking. The authors sought to decipher the impacts of the patient, surgical practice, and surgeon on satisfaction with outcome following anterior cervical discectomy and fusion (ACDF). METHODS The authors queried the Quality Outcomes Database for patients undergoing 1- to 2-level ACDF for degenerative spine disease since 2013. Patient satisfaction with the surgical outcome as measured by the North American Spine Society (NASS) scale comprised the primary outcome. A multivariable proportional odds logistic regression model was constructed with adjustments for baseline patient characteristics and surgical practice and surgeon characteristics as fixed effects. RESULTS A total of 4148 patients (median age 54 years, 48% males) with complete 12-month NASS satisfaction data were analyzed. Sixty-seven percent of patients answered that “surgery met their expectations” (n = 2803), while 20% reported that they “did not improve as much as they had hoped but they would undergo the same operation for the same results” (n = 836). After adjusting for a multitude of patient-specific as well as hospital- and surgeon-related factors, the authors found baseline Neck Disability Index (NDI) score, US geographic region of hospital, patient race, insurance status, symptom duration, and Workers’ compensation status to be the most important predictors of patient satisfaction. The discriminative ability of the model was satisfactory (c-index 0.66, overfitting-corrected estimate 0.64). CONCLUSIONS The authors’ results found baseline NDI score, patient race, insurance status, symptom duration, and Workers’ compensation status as well as the geographic region of the hospital to be the most important predictors of long-term patient satisfaction after a 1- to 2-level ACDF. The findings of the present analysis further reinforce the role of preoperative discussion with patients on setting treatment goals and realistic expectations.

Study Design: A retrospective study. Objectives: (1) To assess the reliability of using the posterior endplate valley (PEV) to predict the cranial-caudal location of the cervical pedicle intraoperatively; (2) to assess the impact of age on the cervical PEV-pedicle relationship, interpedicular distance, and foraminal height. Summary of Background Data: The cervical pedicle, which is the anatomic landmark defining the boundaries of the foramen, is hidden from view intraoperatively in the anterior cervical approach, potentially leading to incomplete foraminal decompression. An intraoperative landmark which heralds the location of the pedicle and therefore can be relied upon as a guide for decompression has not been previously described. Methods: We retrospectively reviewed cervical computed tomography images of younger (<50 y) and older (>50 y) patients. Using the coronal reconstructed image taken at the posterior margin of the vertebral body, we constructed a line between the superior aspect of the pedicles and measured the distance from this line to the PEV. Interpedicular distance and foraminal height were also measured. Results: One hundred patients were included in the final analysis. The mean distance (mm) from the pedicular line to the PEV from C3 to C7 respectively was 1.0±0.99, 0.01±0.76, 0.09±0.70, 0.20±0.71, and 0.27±0.79. No significant difference between young and elderly patients was noted (P<0.05). Intervertebral foraminal size was significantly greater in younger compared with elderly patients at all levels except C2–C3. The mean interpedicular distance was 23.05±1.76 mm. Conclusions: This study demonstrates, for the first time, that the PEV is an accurate surgical landmark that is consistently at most 1 mm from the superior aspect of the cervical pedicle in the subaxial spine. Furthermore, this study demonstrated that foraminal height was significantly larger in younger compared with elderly patients at all cervical levels below C3. Level of Evidence: Level 3.

Abstract BACKGROUND Degenerative spondylolisthesis is the displacement of one vertebral body over the adjacent one. While standing and flexion-extension X-rays are preferred for determining listhesis, magnetic resonance imaging (MRI) is often utilized to assess the compression of nerve root or spinal cord. OBJECTIVE To investigate the difference in radiographic measurements of spondylolisthesis between X-rays and MRI. METHODS We retrospectively reviewed the records and radiographic images of patients with a confirmed diagnosis of spondylolisthesis undergoing operation in 2016. Primary variable of interest was the degree of slippage as per the Meyerding method. Agreement between the 2 reviewers was assessed using the 2-way intraclass correlation coefficient (ICC) for slippage percentage and Cohen's Kappa for grade. Agreement of Meyerding grade between the 2 imaging techniques was assessed using Cohen's Kappa, while the slip percentage measured for each technique was compared using a Bland-Altman (BA) plot, mean difference (MD), and 1-way ICC. RESULTS A total of 255 cases were analyzed. ICC between the 2 reviewers was found to be 0.75 (95% confidence interval [CI] = 0.64-0.83, P < .001) for X-ray and 0.76 (95% CI = 0.66-0.83, P < .001) for MRI. Agreement between X-ray and MRI for grading of spondylolisthesis was found to be poor (kappa = 0.32, P < .001). BA plot between X-ray and MRI measurements revealed an MD of 4.4% (95% limits of agreement: –10.3% to 19.3%) with 5.16% observations outside the limits of agreement and 1-way ICC of 0.35 showing poor agreement. Conclusion Our results demonstrate the discrepancy of spondylolisthesis grade measurements between weight-bearing X-ray and nonweight-bearing MRI. Careful evaluation of both imaging technique is warranted to determine the final severity of pathology and tailoring of management plan.

Abstract BACKGROUND Degenerative cervical myelopathy (DCM) is a progressive disease resulting from cervical cord compression. The modified Japanese Orthopaedic Association (mJOA) is commonly used to grade myelopathic symptoms, but its persistent postoperative improvement has not been previously explored. OBJECTIVE To utilize the Quality Outcomes Database (QOD) to evaluate the trajectory of outcomes in those operatively treated for DCM. METHODS This study is a retrospective analysis of prospectively collected data. The QOD was queried for patients undergoing elective surgery for DCM. Patients were divided into mild (≥14), moderate (9-13), or severe (<9) categories for their baseline severity of myelopathic symptoms (mJOA scores). A parsimonious multivariable logistic regression model was fitted with 2 points improvement on mJOA from 3- to 12-mo follow-up as the outcome of interest. RESULTS A total of 2156 patients who underwent elective surgery for DCM and had complete 3- and 12-mo follow-up were included in our analysis. Patients improved significantly from baseline to 3-mo on their mJOA scores, regardless of their baseline mJOA severity. After adjusting for the relevant preoperative characteristics, the baseline mJOA categories had significant impact on outcome of whether a patient keeps improving in mJOA score from 3 to 12 mo postsurgery. Patient with severe mJOA score at baseline had a higher likelihood of improvement in their myelopathic symptoms, compared to patients with mild mJOA score in. CONCLUSION Most patients achieve improvement on a shorter follow-up; however, patients with severe symptoms keep on improving until after a longer follow-up. Preoperative identification of such patients helps the clinician settling realistic expectations for each follow-up timepoint.

OBJECTIVENonhome discharge and unplanned readmissions represent important cost drivers following spinal fusion. The authors sought to utilize different machine learning algorithms to predict discharge to rehabilitation and unplanned readmissions in patients receiving spinal fusion.METHODSThe authors queried the 2012–2013 American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) for patients undergoing cervical or lumbar spinal fusion. Outcomes assessed included discharge to nonhome facility and unplanned readmissions within 30 days after surgery. A total of 7 machine learning algorithms were evaluated. Predictive hierarchical clustering of procedure codes was used to increase model performance. Model performance was evaluated using overall accuracy and area under the receiver operating characteristic curve (AUC), as well as sensitivity, specificity, and positive and negative predictive values. These performance metrics were computed for both the imputed and unimputed (missing values dropped) datasets.RESULTSA total of 59,145 spinal fusion cases were analyzed. The incidence rates of discharge to nonhome facility and 30-day unplanned readmission were 12.6% and 4.5%, respectively. All classification algorithms showed excellent discrimination (AUC > 0.80, range 0.85–0.87) for predicting nonhome discharge. The generalized linear model showed comparable performance to other machine learning algorithms. By comparison, all models showed poorer predictive performance for unplanned readmission, with AUC ranging between 0.63 and 0.66. Better predictive performance was noted with models using imputed data.CONCLUSIONSIn an analysis of patients undergoing spinal fusion, multiple machine learning algorithms were found to reliably predict nonhome discharge with modest performance noted for unplanned readmissions. These results provide early evidence regarding the feasibility of modern machine learning classifiers in predicting these outcomes and serve as possible clinical decision support tools to facilitate shared decision making.

Abstract BACKGROUND Modern healthcare reforms focus on identifying and measuring the quality and value of care. Patient satisfaction is particularly important in the management of degenerative cervical radiculopathy (DCR) since it leads to significant neck pain and disability primarily affecting the patients’ quality of life. OBJECTIVE To determine the association of baseline and 12-mo Neck Disability Index (NDI) with patient satisfaction after elective surgery for DCR. METHODS The Quality Outcomes Database cervical module was queried for patients who underwent elective surgery for DCR. A multivariable proportional odds regression model was fitted with 12-mo satisfaction as the outcome. The covariates for this model included patients’ demographics, surgical characteristics, and baseline and 12-mo patient reported outcomes (PROs). Wald-statistics were calculated to determine the relative importance of each independent variable for 12-mo patient satisfaction. RESULTS The analysis included 2206 patients who underwent elective surgery for DCR. In multivariable analysis, after adjusting for baseline and surgery specific variables, the 12-mo NDI score showed the highest association with 12-mo satisfaction (Waldχ2-df = 99.17, 58.1% of total χ2). The level of satisfaction increases with decrease in 12-mo NDI score regardless of the baseline NDI score. CONCLUSION Our study identifies 12-mo NDI score as a very influential driver of 12-mo patient satisfaction after surgery for DCR. In addition, there are lesser contributions from other 12-mo PROs, baseline Numeric Rating Scale for arm pain and American Society of Anesthesiologists (ASA) grade. The baseline level of disability was found to be irrelevant to patients. They seemed to only value their current level of disability, compared to baseline, in rating satisfaction with surgical outcome.