Priscilla H. Chan

Surgical Technique Trends in Primary Acl Reconstruction from 2007 to 2014

BACKGROUND The surgical technique for anterior cruciate ligament (ACL) reconstruction has evolved as a result of improved understanding of ligament biomechanics, anatomy, device development, and failed reconstructions. Studies on surgical technique preferences have been limited to surgeon surveys, which are subject to selection and recall bias. The purpose of this study was to evaluate ACL reconstruction surgical technique and yearly revision rate trends in a community-based setting. METHODS A population-based epidemiological study was conducted using data on primary ACL reconstruction procedures registered in an ACL reconstruction registry from 2007 to 2014. Changes in the incidence rates of different types of femoral tunnel drilling methods, different types of grafts and graft fixation, and revisions were studied. Adjusted incidence rate ratios (IRRs) are provided. RESULTS Of the 21,686 ACL reconstructions studied, 72.4% were performed by sports medicine fellowship-trained surgeons. The incidence rate of femoral tunnel drilling via a tibial tunnel decreased at an adjusted rate of 26% per year (IRR = 0.74, 95% confidence interval [CI] = 0.71 to 0.78), from 56.4% to 17.6% during the study period. The incidence rate of medial portal drilling increased from 41.3% to 65.1% at an adjusted rate of 11% per year (IRR = 1.11, 95% CI = 1.09 to 1.13), and the incidence rate of drilling through a lateral approach increased from 2.3% to 17.3% at an adjusted rate of 53% per year (IRR = 1.53, 95% CI = 1.39 to 1.67). There was no change in the use of hamstring autograft, bone-patellar tendon-bone autograft, or tibial tendon allograft. Use of first-generation bioabsorbable femoral and tibial fixation decreased for all graft types. For soft-tissue grafts, usage of suspensory metal femoral fixation increased 12% to 13% per year (IRR = 1.12, 95% CI = 1.09 to 1.15 for tibial tendon grafts; IRR = 1.13, 95% CI = 1.10 to 1.15 for hamstring grafts). For bone-patellar tendon-bone autografts, the use of femoral fixation with interference biocomposite screws increased 7% per year (IRR = 1.07, 95% CI = 1.04 to 1.10). On the tibial side, utilization of biocomposite screws increased for all graft types. No association was found between revision rate and the year of the primary operation. CONCLUSIONS Surgeons changed their femoral tunnel drilling technique over the study period, whereas the incidence rates of specific graft utilization remained stable. There has been a shift away from first-generation bioabsorbable fixation and increasing use of biocomposite fixation across all graft types. Early cumulative revision rates remained stable.

Similar mortality with general or regional anesthesia in elderly hip fracture patients

Background and purpose — There is continuing confusion among practitioners with regard to the optimal choice of anesthetic type for repair of hip fractures. We investigated whether type of anesthetic was associated with short-term mortality after hip fracture surgery. Patients and methods — We conducted a retrospective cohort study of patients with surgically treated hip fractures, performed between January 1, 2009 and December 31, 2012. Exposure of interest was anesthesia type (general, spinal/neuroaxial, and mixed). Endpoints were 30-, 90-, and 365-day post-surgery mortality. Multivariable conditional logistic regression models were used and odds ratios (ORs) and 95% confidence intervals (CIs) are reported. Results — Of the 7,585 participants, 5,412 (71%) were women and the median age was 80 (IQR: 72–85) years old. Of the total cohort, 4,257 (56%) received general anesthesia, 3,059 (40%) received spinal/neuroaxial, and 269 (4%) received mixed anesthesia. Overall, the incidence of 30-, 90-, and 365-day mortality was 4% (n = 307), 8% (n = 583), and 15% (n = 1,126), respectively. When compared with general anesthesia, the 365-day odds of mortality was marginally lower in patients with spinal/neuroaxial anesthesia (OR = 0.84, CI: 0.70–1.0), but it was similar in patients with mixed anesthesia (OR = 1.3, CI: 0.70–2.3). No other statistically significant differences were observed. Interpretation — Regarding mortality, this study does not support specific recommendations regarding the type of anesthetic in surgery of fractured hips.

Yearly Trends in Elective Shoulder Arthroplasty, 2005–2013

To evaluate the change in incidence rate of shoulder arthroplasty, the utilization of shoulder arthroplasty for specific indications, and the surgeon volume trends associated with these procedures between 2005 and 2013.

Antibiotic cement was associated with half the risk of re-revision in 1,154 aseptic revision total knee arthroplasties

Background and purpose — Aseptic revisions comprise 80% of revision total knee arthroplasties (TKAs). We determined the incidence of re-revision TKA, the reasons for re-revision, and risk factors associated with these procedures. Patients and methods — We conducted a retrospective cohort study of 1,154 patients who underwent aseptic revision TKA between 2002 and 2013 and were followed prospectively by a total joint replacement registry in the USA. Revision was defined as any operation in which an implanted component was replaced. Patient-, surgeon-, and procedure-related risk factors were evaluated. Survival analyses were conducted. Results — There were 114 re-revisions (10%) with a median time to reoperation of 3.6 years (interquartile range (IQR): 2.6–5.2). The infection rate was 2.9% (34/1,154) and accounted for 30% of re-revisions (34 of 114). In adjusted models, use of antibiotic-loaded cement was associated with a 50% lower risk of all-cause re-revision surgery (hazard ratio (HR) = 0.5, 95% CI: 0.3–0.9), age with a 20% lower risk for every 10-year increase (HR = 0.8, CI: 0.7–1.0), body mass index (BMI) with a 20% lower risk for every 5-unit increase (HR = 0.8, CI: 0.7–1.0), and a surgeon’s greater cumulative experience (≥ 20 cases vs. < 20 cases) with a 3 times higher risk of re-revision (HR = 2.8, CI: 1.5–5). Interpretation — Revised TKAs were at high risk of subsequent failure. The use of antibiotic-loaded cement, higher age, and higher BMI were associated with lower risk of further revision whereas a higher degree of surgeon experience was associated with higher risk.

Yearly Trends in Elective Shoulder Arthroplasty, 2005 through 2013

To evaluate the change in incidence rate of shoulder arthroplasty, the utilization of shoulder arthroplasty for specific indications, and the surgeon volume trends associated with these procedures between 2005 and 2013.

Risk factors for postoperative opioid use after elective shoulder arthroplasty

BACKGROUND The opioid epidemic remains a serious issue in the United States with significant impact to the medical and socioeconomic welfare of communities. We sought to determine baseline opioid use in patients undergoing shoulder arthroplasty (SA) and identify patient characteristics, comorbidities, and surgical risk factors associated with postoperative opioid use. METHODS A Shoulder Arthroplasty Registry identified the number of dispensed opioid medication prescriptions (Rxs) in the first postoperative year in patients who underwent elective primary SA from 2008 to 2014. We used Poisson regression to study the effect of preoperative risks factors on number of dispensed opioid Rxs in the first postoperative year, evaluated quarterly (Q1: days 0-90, Q2: days 91-180, Q3: days 181-270, Q4: days 271-360). RESULTS Included were 4243 SAs from 3996 patients, and 75% used opioids in the 1-year preoperative period. The factors associated with increased opioid use in all postoperative quarters (Q4 incident rate ratio [IRR] shown) were age <60 years (IRR, 1.40; 95% confidence interval [CI], 1.29-1.51), preoperative opioid use (1-4 Rxs: IRR, 2.15; 95% CI, 1.85-2.51; ≥5 Rxs: IRR, 9.83; 95% CI , 8.53-11.32), anxiety (IRR, 1.11; 95% CI, 1.03-1.20), opioid dependence (IRR, 1.23; 95% CI, 1.05-1.43), substance abuse (IRR, 1.17; 95% CI, 1.07-1.28), and general chronic pain (IRR, 1.38; 95% CI, 1.28-1.50). CONCLUSION Opioid usage in patients undergoing SA is widespread at 1 year, with three-fourths of patients having been dispensed at least one Rx. These findings emphasize the need for surgeon and patient awareness as well as education in the management of postoperative opioid usage associated with the indicated conditions. Surgeons may consider these risk factors for preoperative risk stratification and targeted deployment of preventative strategies.

Is Anesthesia Technique Associated With a Higher Risk of Mortality or Complications Within 90 Days of Surgery for Geriatric Patients With Hip Fractures

Background Postoperative mortality and complications after geriatric hip fracture surgery remain high despite efforts to improve perioperative care for these patients. One factor of particular interest is anesthetic technique, but prior studies on this are limited by sample selection, competing risks, and incomplete followup. Questions/purposes (1) Among older patients undergoing surgery for hip fracture, does 90-day mortality differ depending on the type of anesthesia received? (2) Do 90-day emergency department returns and hospital readmissions differ based on anesthetic technique after geriatric hip fracture repairs? (3) Do 90-day Agency for Healthcare Research and Quality (AHRQ) outcomes differ according to anesthetic techniques used during hip fracture surgery? Methods We conducted a retrospective study on geriatric patients (65 years or older) with hip fractures between 2009 and 2014 using the Kaiser Permanente Hip Fracture Registry. A total of 1995 (11%) of the surgically treated patients with hip fracture were excluded as a result of missing anesthesia information. The final study sample consisted of 16,695 patients. Of these, 2027 (12%) died and 98 (< 1%) terminated membership during followup, which were handled as competing events and censoring events, respectively. Ninety-day mortality, emergency department returns, hospital readmission, deep vein thrombosis (DVT) or pulmonary embolism (PE), myocardial infarction (MI), and pneumonia were evaluated using multivariable competing risk proportional subdistribution hazard regression according to type of anesthesia technique: general anesthesia, regional anesthesia, or conversion from regional to general. Of the 16,695 patients, 58% (N = 9629) received general anesthesia, 40% (N = 6597) received regional anesthesia, and 2.8% (N = 469) patients were converted from regional to general. Results Compared with regional anesthesia, patients treated with general anesthesia had a higher likelihood of overall 90-day mortality (hazard ratio [HR], 1.22; 95% confidence interval [CI], 1.11-1.35; p < 0.001); however, when stratified by before and after hospital discharge but within 90 days of surgery, this higher risk was only observed during the inpatient stay (HR, 3.83; 95% CI, 3.18-4.61; p < 0.001); no difference was observed after hospital discharge (HR, 1.04; 95% CI, 0.94-1.16; p = 0.408). Patients undergoing conversion from regional to general also had a higher overall mortality risk compared with those undergoing regional anesthesia (HR, 1.34; 95% CI 1.04-1.74; p = 0.026), but this risk was only observed during their inpatient stay (HR, 6.84; 95% CI, 4.21-11.11; p < 0.001) when stratifying by before and after hospital discharge. Patients undergoing general anesthesia had a higher risk for all-cause readmission when compared with regional anesthesia (HR, 1.09; 95% CI, 1.01-1.19; p = 0.026). No differences according to anesthesia type were observed for risk of 90-day AHRQ outcomes, including DVT/PE, MI, and pneumonia. Conclusions We found the use of general anesthesia and conversion from regional to general anesthesia were associated with a higher risk of mortality during the in-hospital stay compared with regional anesthetic techniques, but this higher risk did not persist after hospital discharge. We also found general anesthesia to be associated with a higher risk of all-cause readmission compared with regional, but no other differences were observed in risk for complications. Our findings suggest regional anesthetic techniques may be preferred when possible in this patient population. Level of Evidence Level III, therapeutic study.

A review and empirical comparison of causal inference methods for clustered observational data with application to the evaluation of the effectiveness of medical devices

Observational studies are commonplace in medicine. A frequent concern is confounding bias due to differences in patient characteristics across treatment groups, but other important issues include dependency among observations nested within clusters (e.g. patients clustered within physicians or surgeons) and confounding due to cluster characteristics (e.g. physician or surgeon experience or training). Given the frequency with which these issues arise in medical research, as well as their relative complexity, methods for the analysis of clustered observational data are reviewed. We argue for estimating causal treatment effects using marginal models that either match or weight observations using a suitable distance metric (e.g. the propensity score). Simulation results demonstrated that methods incorporating clustering into calculation of the variance were generally more accurate than those that did not. Moreover, methods that account for cluster confounding when estimating the treatment effect were least biased and most accurate. Throughout the paper we illustrate the proposed methods in a medical device setting that compares the effectiveness of femoral heads used in total hip replacements. Whenever possible the clustered aspect of the data should be considered in the design of the study when constructing the distance measure or in the matching process, as well as in the analysis when estimating the variance of the treatment effect.