Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where David C. Sing is active.

Publication


Featured researches published by David C. Sing.


Journal of Bone and Joint Surgery, American Volume | 2016

Overlapping Surgery in the Ambulatory Orthopaedic Setting.

Alan L. Zhang; David C. Sing; Debbie Y. Dang; C. Benjamin Ma; Dennis M. Black; Thomas P. Vail; Brian T. Feeley

BACKGROUND The practice of a surgeon performing procedures in two operating rooms during overlapping time frames has been described as concurrent surgery if critical portions occur simultaneously, or overlapping surgery if they do not. Although recent media reports have focused on the potential adverse effects of these practices, to our knowledge, there has been no previous research investigating outcomes of overlapping procedures in orthopaedic surgery. METHODS A retrospective review of an institutional clinical database from 2012 to 2015 was utilized to collect data from all surgical cases (including sports medicine, hand, and foot and ankle) performed at an ambulatory orthopaedic surgery center. Patient demographic characteristics, types of procedures, operating room time, procedure time, and 30-day outcomes including complications, unplanned hospital readmissions, unplanned reoperations, and emergency department visits were collected. The amount of overlap time between cases was also analyzed. Pearson chi-square tests, Student t tests, and logistic regression were used for statistical analysis. RESULTS Of 3,640 cases performed, 68% were overlapping procedures and 32% were non-overlapping. There was no difference in the mean age, sex, body mass index, American Society of Anesthesiologists rating, or Charlson Comorbidity Index between patients who had overlapping procedures and those who did not. Comparison of overlapping surgery cases and non-overlapping surgery cases revealed no difference in the mean procedure time (70.7 minutes compared with 72.8 minutes; p = 0.116) or total operating room time (105.4 minutes compared with 105.5 minutes; p = 0.949). Complications were tracked for 30 days after procedures and yielded a rate of 1.1% for overlapping surgeries and 1.3% for non-overlapping surgeries (p = 0.811). Stratification based on subspecialty surgery also demonstrated no difference in complications between the cohorts. Fifty percent of overlapping cases overlapped by <1 hour of operating room time, but 7% overlapped by >2 hours. The rate of complications was found to have no association with the amount of overlap between cases (p = 0.151). CONCLUSIONS Overlapping surgery yields equivalent patient operating room time, procedure time, and 30-day complication rates as non-overlapping surgery in the ambulatory orthopaedic setting. Further investigation is warranted for inpatient orthopaedic procedures and across all orthopaedic subspecialties. LEVEL OF EVIDENCE Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.


Orthopaedic Journal of Sports Medicine | 2016

The rise of concussions in the adolescent population

Alan L. Zhang; David C. Sing; Caitlin M. Rugg; Brian T. Feeley; Carlin Senter

Background: Concussion injuries have been highlighted to the American public through media and research. While recent studies have shown increased traumatic brain injuries (TBIs) diagnosed in emergency departments across the United States, no studies have evaluated trends in concussion diagnoses across the general US population in various age groups. Purpose: To evaluate the current incidence and trends in concussions diagnosed across varying age groups and health care settings in a large cross-sectional population. Study Design: Descriptive epidemiological study. Methods: Administrative health records of 8,828,248 members of a large private-payer insurance group in the United States were queried. Patients diagnosed with concussion from years 2007 through 2014 were stratified by year of diagnosis, age group, sex, classification of concussion, and health care setting of diagnosis (eg, emergency department vs physician’s office). Chi-square testing was used for statistical analysis. Results: From a cohort of 8,828,248 patients, 43,884 patients were diagnosed with a concussion. Of these patients, 55% were male and over 32% were in the adolescent age group (10-19 years old). The highest incidence of concussion was seen in patients aged 15 to 19 years (16.5/1000 patients), followed by those aged 10 to 14 years (10.5/1000 patients), 20 to 24 years (5.2/1000 patients), and 5 to 9 years (3.5/1000 patients). Overall, there was a 60% increase in concussion incidence from 2007 to 2014. The largest increases were in the 10- to 14-year (143%) and 15- to 19-year (87%) age groups. Based on International Classification of Disease–9th Revision classification, 29% of concussions were associated with some form of loss of consciousness. Finally, 56% of concussions were diagnosed in the emergency department and 29% in a physician’s office, with the remainder in urgent care clinics or inpatient settings. Conclusion: The incidence of concussion diagnosed in the general US population is increasing, driven largely by a substantial rise in the adolescent age group. The youth population should be prioritized for ongoing work in concussion education, diagnosis, treatment, and prevention. Clinical Relevance: The rise of concussions in the adolescent age group across the general population is concerning, and clinical efforts to prevent these injuries are needed.


Spine | 2014

Hospital readmission rates after surgical treatment of primary and metastatic tumors of the spine.

William W. Schairer; Alexandra Carrer; David C. Sing; Dean Chou; Praveen V. Mummaneni; Serena S. Hu; Sigurd Berven; Shane Burch; Bobby Tay; Vedat Deviren; Christopher P. Ames

Study Design. Retrospective cohort study. Objective. This study aimed to identify the rates and causes of unplanned hospital readmission at 30 days and 1 year after surgical treatment of primary and metastatic spinal tumors. Summary of Background Data. Primary spine tumors and non–spine tumors metastatic to the spine can represent complex problems for surgical treatment, but surgical intervention can provide significant patients with significant improvements in quality of life. However, recent emphasis on decreasing the cost of health care has led to a focus on quality measures such as hospital readmission rates. Methods. At a large referral spine center between 2005 and 2011, 197 patients with primary (n = 33) or metastatic (n = 164) tumors of the spine were enrolled. Hospital readmissions within 1 year were reviewed. Kaplan-Meier analysis was performed to estimate unplanned hospital readmission rates, and risk factors were evaluated using a Cox proportional hazards model. Results. Unplanned hospital readmission rates were 6.1% and 16.8% at 30 days for primary and metastatic tumors (P = 0.126), respectively, and 27.5% and 37.8% at 1 year (P = 0.262). Metastatic tumors with aggressive biology (i.e., lung, osteosarcoma, stomach, bladder, esophagus, pancreas) caused higher rates of readmission than other types of metastatic tumors. One-third of readmissions were due to recurrent disease, whereas 23.3% were due to surgical complications and 43.3% due to medical complications. Numerous medical comorbidities increased the risk of unplanned hospital readmission. Conclusion. Unplanned hospital readmissions after surgical intervention for spine tumors are common, and patients with aggressive metastatic tumors are at increased risk. In addition, comorbid medical problems are important risk factors that increase the chance that a patient will require hospital readmission within 1 year. Level of Evidence: 3


Journal of Shoulder and Elbow Surgery | 2016

Proximal humerus fragility fractures: recent trends in nonoperative and operative treatment in the Medicare population.

Richard J. Han; David C. Sing; Brian T. Feeley; C. Benjamin Ma; Alan L. Zhang

BACKGROUND With an aging population, fragility fractures including injuries to the proximal humerus continue to rise in the United States. The purpose of this study was to investigate recent trends in the incidence and treatment of proximal humerus fractures (PHFs) in a cross-sectional elderly population. METHODS Medicare data from 2005 to 2012 were queried to identify patients treated for PHF. Associated patient demographics, hospitalization data, treatment, and revision status were obtained. Statistical analyses were performed to identify significant trends in treatment. RESULTS There were 259,506 PHFs recorded, with 79% occurring in female patients. In all age groups, nonoperative treatment of PHF was the most common method (67%). Within the surgical group, open reduction with internal fixation was most frequently used, and total shoulder arthroplasty (TSA) or reverse total shoulder arthroplasty (RTSA) was the least common (11%). However, although the overall rate of surgical intervention remained constant, there was a significant increase in treatment with TSA from 3% in 2005 to 17% in 2012. In particular, RTSA represented 89% of all TSAs for PHF in 2011. All surgical treatment options demonstrated high 2-year survival rates without revision surgery (97%). CONCLUSION Recent trends show that in the elderly population, nonoperative management remains the most common treatment for PHFs. Within the surgically treated cohort, there has been an increase in treatment with arthroplasty including RTSA, with a low rate of early revisions. There are excellent survival rates in all surgically treated PHFs, but long-term data will be required to fully evaluate the viability of these surgical options.


Spine | 2016

Obesity Is an Independent Risk Factor of Early Complications After Revision Spine Surgery.

David C. Sing; John K. Yue; Lionel N. Metz; Ethan A. Winkler; William R. Zhang; Shane Burch; Sigurd Berven

Study Design. Retrospective cohort analysis of risk factors in revision spine surgery using a prospectively collected database. Objective. To examine the risk of developing early (30-day) complications across obesity level after adjusting for comorbidities in patients undergoing revision spine surgery. Summary of Background Data. Prior studies suggest obesity influences early complications after primary surgery. The association between obesity and early complications after revision surgery remains to be characterized. Methods. Data were abstracted from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from 2005 to 2012. Adult Caucasian patients undergoing removal/revision of instrumentation or exploration of fusion were included. Patients were categorized by WHO body mass index (BMI, kg/m2): Non-Obese (18.5–29.9), Obese Class I (30–34.9), and Obese Class II/III (≥35). Univariate regression was performed to assess the predictive value of obesity level and baseline risk factors in the presence of at least one early complication, and significant predictors were entered into the multivariable model. Results. Of 2538 patients, 57.6% were nonobese, 23% Obese Class I, and 19.4% Obese Class II/III. Obesity was associated with diabetes, hypertension, respiratory disease, and American Society of Anesthesiologists (ASA) score of 3–4 (all P < 0.001). BMI group (P = 0.01), older age (P = 0.008), functional dependence (P < 0.001), ASA 3–4 (P = 0.008), bleeding disorder (P = 0.04), and diabetes (P = 0.016) were identified as univariate predictors for early complications. In the multivariable model, higher BMI (P = 0.04), older age (P = 0.014), and functional dependence (P < 0.001) remained significant predictors for early complications. Notably, patients who were Obese Class II/III (OR 1.66, 95% CI [1.12–2.45]), age ≥75 (OR 1.83, [1.20–2.81]), and functionally dependent (OR 3.02 [1.85–4.94]) had significantly higher risk compared with their reference groups. Conclusion. Obesity is an independent risk factor for early complications after revision spine surgery. Although obesity may not contraindicate revision surgery, its status as a modifiable risk factor warrants disclosure and preoperative counseling to optimize outcomes. Level of Evidence: 3


European Spine Journal | 2017

ISSLS PRIZE IN BASIC SCIENCE 2017: Intervertebral disc/bone marrow cross-talk with Modic changes

Stefan Dudli; David C. Sing; Serena S. Hu; Sigurd Berven; Shane Burch; Vedat Deviren; Ivan Cheng; Bobby Tay; Todd Alamin; Ma Agnes Ith; Eric Pietras; Jeffrey C. Lotz

Study designCross-sectional cohort analysis of patients with Modic Changes (MC).ObjectiveOur goal was to characterize the molecular and cellular features of MC bone marrow and adjacent discs. We hypothesized that MC associate with biologic cross-talk between discs and bone marrow, the presence of which may have both diagnostic and therapeutic implications.Background dataMC are vertebral bone marrow lesions that can be a diagnostic indicator for discogenic low back pain. Yet, the pathobiology of MC is largely unknown.MethodsPatients with Modic type 1 or 2 changes (MC1, MC2) undergoing at least 2-level lumbar interbody fusion with one surgical level having MC and one without MC (control level). Two discs (MC, control) and two bone marrow aspirates (MC, control) were collected per patient. Marrow cellularity was analyzed using flow cytometry. Myelopoietic differentiation potential of bone marrow cells was quantified to gauge marrow function, as was the relative gene expression profiles of the marrow and disc cells. Disc/bone marrow cross-talk was assessed by comparing MC disc/bone marrow features relative to unaffected levels.ResultsThirteen MC1 and eleven MC2 patients were included. We observed pro-osteoclastic changes in MC2 discs, an inflammatory dysmyelopoiesis with fibrogenic changes in MC1 and MC2 marrow, and up-regulation of neurotrophic receptors in MC1 and MC2 bone marrow and discs.ConclusionOur data reveal a fibrogenic and pro-inflammatory cross-talk between MC bone marrow and adjacent discs. This provides insight into the pain generator at MC levels and informs novel therapeutic targets for treatment of MC-associated LBP.


Journal of Arthroplasty | 2016

Prior Lumbar Spinal Arthrodesis Increases Risk of Prosthetic-Related Complication in Total Hip Arthroplasty.

David C. Sing; Jeffrey J. Barry; Thomas Aguilar; Alexander A. Theologis; Joseph T. Patterson; Bobby Tay; Thomas P. Vail; Erik N. Hansen

BACKGROUND Degenerative hip disorders often coexist with degenerative changes of the lumbar spine. Limited data on this patient population suggest inferior functional improvement and pain relief after surgical management. The purpose of this study is to compare the rates of prosthetic-related complication after primary total hip arthroplasty (THA) in patients with and without prior lumbar spine arthrodesis (SA). METHODS Medicare patients (n = 811,601) undergoing primary THA were identified and grouped by length of prior SA (no fusion, 1-2 levels fused [S-SAHA], and ≥3 levels fused [L-SAHA]). RESULTS Compared with controls, patients with prior SA had significantly higher rates of complications including dislocation (control: 2.36%; S-SAHA: 4.26%; and L-SAHA: 7.51%), revision (control: 3.43%, S-SAHA: 5.55%, and L-SAHA: 7.77%), loosening (control: 1.33%, S-SAHA: 2.10%, and L-SAHA: 3.04%), and any prosthetic-related complication (control: 7.33%, S-SAHA: 11.15% [relative risk: 1.52], and L-SAHA: 14.16% [relative risk: 1.93]) within 24 months (P < .001). CONCLUSION The interplay of coexisting degenerative hip and spine disease deserves further attention of both arthroplasty and spine surgeons.


Journal of Arthroplasty | 2017

The James A. Rand Young Investigator's Award: Administrative Claims vs Surgical Registry: Capturing Outcomes in Total Joint Arthroplasty

Joseph T. Patterson; David C. Sing; Erik N. Hansen; Bobby Tay; Alan L. Zhang

BACKGROUND Administrative claims in total joint arthroplasty are used for observational studies and payment adjustments under the Comprehensive Care for Joint Replacement (CJR) legislation. Claims data have not been validated against prospective surgical outcome registries for primary total hip (THA) or knee arthroplasty (TKA). We hypothesized that significant differences in reported comorbidity and adverse event measures exist between administrative claims and prospective registry data relevant to payment adjudication under the CJR reimbursement model. METHODS Comorbidities and outcomes in primary TKA and THA in the United Healthcare and Medicare Standard Analytical File 5% Sample insurance claims datasets (PearlDiver Technologies, Inc) were compared to age-matched cohorts from the National Surgical Quality Improvement Program (ACS-NSQIP) surgical outcomes data from 2007 to 2011 using comparable International Classification of Diseases, Ninth Revision, Clinical Modification and Current Procedural Terminology codes at 30, 90, and 360 days from index arthroplasty. Pearsons chi-square test was used for statistical analyses. RESULTS The total study population included 93,953 primary THA and 176,944 TKA patients. Primary TKA and THA patients in insurance claims cohorts had significantly fewer reported comorbidities, higher rates of surgical site infection, pulmonary embolism, wound dehiscence, thromboembolic events, and neurologic deficits, and lower reported rates of revision surgery than ACS-NSQIP cohorts within 30 days of primary TKA and THA. Cumulative incidence of adverse events increased significantly from 30 to 360 days after primary arthroplasty. CONCLUSION We report significant discordance in the prevalence of patient comorbidities and incidence of adverse events in primary THA and TKA between ACS-NSQIP and the administrative claims data of Medicare and United Healthcare. These disparities have implications for observational outcome studies as well as payment adjudication under the CJR reimbursement model in total joint arthroplasty.


Journal of Shoulder and Elbow Surgery | 2017

The perioperative effects of chronic preoperative opioid use on shoulder arthroplasty outcomes

Jonathan W. Cheah; David C. Sing; Dell McLaughlin; Brian T. Feeley; C. Benjamin Ma; Alan L. Zhang

HYPOTHESIS AND BACKGROUND Chronic opioid therapy is an increasingly used modality for the treatment of osteoarthritis-associated pain. We hypothesized that chronic opioid use would be associated with adverse outcomes in shoulder arthroplasty. METHODS A retrospective analysis of patients undergoing elective anatomic total shoulder arthroplasty (TSA) and reverse total shoulder arthroplasty (rTSA) at a single institution from 2012-2015 was performed. Patients were stratified by preoperative opioid use (nonusers, short-acting opioid users, and long-acting opioid users), and their postoperative clinical outcomes were assessed. RESULTS We identified 262 patients (170 rTSA and 92 anatomic TSA), of whom 138 were using opioids preoperatively (82% short acting and 18% long acting). When non-opioid users, short-acting opioid users, and long-acting opioid users were compared, mean total milligrams of morphine equivalents administered during postoperative hospitalization was significantly higher for those with preoperative opioid use (66.9 mg, 111.4 mg, and 208.3 mg, respectively; P < .001). In addition, postoperative visual analog scale pain scores were higher on postoperative day 0 (2.6, 3.2, and 3.9, respectively; P = .007), day 1 (4.0, 4.9, and 6.0, respectively; P < .001), and day 2 (3.0, 3.9, and 5.1, respectively; P < .001). Opioid use was not associated with a significantly increased hospital length of stay, complications, or readmission rates. For patients who completed 2-year follow-up, both the opioid user and non-opioid user groups demonstrated similarly improved postoperative American Shoulder and Elbow Surgeons shoulder scores. CONCLUSION A preoperative history of opioid use before shoulder arthroplasty was associated with significantly higher perioperative opioid consumption and visual analog scale scores. However, unlike in patients undergoing total knee or hip arthroplasty, preoperative opioid use was not associated with increased hospital length of stay, perioperative complications, or 90-day readmission rates for shoulder arthroplasty.


Journal of Shoulder and Elbow Surgery | 2017

Insurance status affects postoperative morbidity and complication rate after shoulder arthroplasty

Xinning Li; David R. Veltre; Antonio Cusano; Paul Yi; David C. Sing; Joel Gagnier; Josef K. Eichinger; Andrew Jawa; Asheesh Bedi

BACKGROUND Shoulder arthroplasty is an effective procedure for managing patients with shoulder pain secondary to end-stage arthritis. Insurance status has been shown to be a predictor of patient morbidity and mortality. The current study evaluated the effect of patient insurance status on perioperative outcomes after shoulder replacement surgery. METHODS Data between 2004 and 2011 were obtained from the Nationwide Inpatient Sample. Analysis included patients undergoing shoulder arthroplasty (partial, total, and reverse) procedures determined by International Classification of Disease, 9th Revision procedure codes. The primary outcome was medical and surgical complications occurring during the same hospitalization, with secondary analyses of mortality and hospital charges. Additional analyses using the coarsened exact matching algorithm were performed to assess the influence of insurance type in predicting outcomes. RESULTS A data inquiry identified 103,290 shoulder replacement patients (68,578 Medicare, 27,159 private insurance, 3544 Medicaid/uninsured, 4009 other). The overall complication rate was 17.2% (n = 17,810) and the mortality rate was 0.20% (n = 208). Medicare and Medicaid/uninsured patients had a significantly higher rate of medical, surgical, and overall complications compared with private insurance using the controlled match data. Multivariate regression analysis found that having private insurance was associated with fewer overall medical complications. CONCLUSION Private insurance payer status is associated with a lower risk of perioperative medical and surgical complications compared with an age- and sex-matched Medicare and Medicaid/uninsured payer status. Mortality was not statistically associated with payer status. Primary insurance payer status should be considered as an independent risk factor during preoperative risk stratification for shoulder arthroplasty procedures.

Collaboration


Dive into the David C. Sing's collaboration.

Top Co-Authors

Avatar

Alan L. Zhang

University of California

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Bobby Tay

San Francisco General Hospital

View shared research outputs
Top Co-Authors

Avatar

Erik N. Hansen

University of California

View shared research outputs
Top Co-Authors

Avatar

Lionel N. Metz

University of California

View shared research outputs
Top Co-Authors

Avatar

Thomas P. Vail

University of California

View shared research outputs
Top Co-Authors

Avatar

C. Benjamin Ma

University of California

View shared research outputs
Top Co-Authors

Avatar

Shane Burch

University of California

View shared research outputs
Top Co-Authors

Avatar

Sigurd Berven

University of California

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge