Faculty Bibliography

INTRODUCTION/BACKGROUND:Choice of articulating spacer in selected Methicillin-resistant Staphylococcus aureus (MRSA) patients with instability that do not qualify for a second-stage revision (i.e., due to significant co-morbidities, multiple persistent infections, open wound ulcers) is challenging. To avoid a recurrent biofilm when using a cruciate-retaining (Cr/Cb) femoral implant, we have utilized a polymer femoral implant and constraint all-polyethylene (all-poly) tibia with stem extensions as a permanent spacer. MATERIALS AND METHODS/METHODS:After removal of prior implants and final debridement, appropriate-sized trial femur and proper thickness all-poly tibia are selected. Two chest tubes are loaded with cement with a delivery gun to make the extension rods. A Steinmann pin is inserted into the stem of the tibial insert. The components are inserted and the knee is reduced, then flexion and extension gaps are assessed. Small adjustments can be made to fill the gaps with extra cement. If there is collateral insufficiency, a constrained polyethylene (poly) can be used with the extension rod. An appropriate antibiotic is used based on the final culture, sensitivity, and availability in powder form. RESULTS:This technique has been performed on 32 MRSA prosthetic joint infection (PJI) cases, followed for a minimum of nine months (nine months to three years). The mean final range of motion was 70 ± 15 degrees (30-110 degrees). Final radiographs do not show any sign of subsidence, loosening, or failure of the spacer. Rate of eradication of infection was 97% in the remaining 31 cases. One patient required amputation due to lack of wound coverage. CONCLUSION/CONCLUSIONS:Custom-made articulating spacer using all-poly tibia and a trial femur with stem extension can provide reproducible outcomes in treating PJI while maintaining mobility.

Background: Proper positioning of the acetabular cup deters dislocation after total hip arthroplasty (THA) and is therefore a key focus for orthopaedic surgeons. The concept of a safe zone for acetabular component placement remains widely utilized in contemporary THA practice; however, components positioned in this safe zone still dislocate. The purpose of this study was to characterize trends in acetabular cup positioning and to determine if the surgical approaches used affected the rate at which the components were placed in the safe zones. Methods: This retrospective, observational study reviewed acetabular cup position in 1,236 patients who underwent THA using computer-assisted navigation. Outcomes included acetabular cup position measurements derived from a surgical navigation device and surgical approach. Results: The overall mean cup position of all recorded cases was 21.8 degrees (±7.7 degrees, 95% CI=6.7 degrees, 36.9 degrees) of anteversion and 40.9 degrees (±6.5 degrees, 95% CI=28.1 degrees, 53.7 degrees) of inclination. For anteversion and inclination, 65.5% (809/1236) of acetabular cup components were within the Lewinnek safe zone, and 58.4% (722/1236) were within the Callanan safe zone. Acetabular cups were placed at a mean of 6.8 degrees of anteversion (posterior/lateral approach: 7.0 degrees, anterior approach: 5.6 degrees) higher than the Lewinnek and Callanan safe zones, whereas inclination was positioned 0.9 degrees higher than the reported Lewinnek safe zone and 3.4 degrees higher than the Callanan safe zone. Conclusions: Our data show that while most acetabular cups were placed within the traditional safe zones, the mean anteversion orientation is considerably higher than those suggested by the Lewinnek and Callanan safe zones. The implications of this observation warrant further investigation. Level of Evidence: Level III.

This study compared the postoperative analgesic efficacy of liposomal bupivacaine as a single-administration adductor canal block (ACB) vs periarticular injection (PAI) for pain control after total knee arthroplasty (TKA). From May 2016 to June 2017, a total of 70 unilateral TKA patients were randomized into 2 groups: PAI (extended-release bupivacaine 266 mg [20-mL vial] with 20 mL of 0.5% bupivacaine hydrochloride and normal saline to a total volume of 120 mL) and ACB (subsartorial saphenous nerve using extended-release bupivacaine 266 mg [20-mL vial]). All patents underwent spinal anesthesia with comprehensive preemptive and postoperative multi-modal pain protocol. All opioids administered were converted to morphine equivalents. Pain was recorded at 4 to 12 hours on the day of surgery, and on postoperative days 1, 2, and 3. Patients and investigators other than the surgeon and anesthesiologist were blinded to the study. The difference in pain scores between the PAI and ACB groups was not statistically significant during the first 12 hours (day 0) after surgery or on postoperative day 1 (5.31 vs 4.26, P=.091). However, on postoperative day 3, the mean pain score increased in the ACB group and decreased in the PAI group (4.8 vs 1.83, P=.037). There was no statistically significant difference between the 2 groups regarding the accumulative daily converted morphine equivalent consumption or total consumption. Although the PAI group demonstrated longer lasting pain relief than the ACB group for the duration of the study, other outcomes were similar between the 2 groups. [Orthopedics. 202x; xx(x):xx-xx.].

Arthrofibrosis is the pathologic stiffening of a joint caused by an exaggerated inflammatory response. As a common complication following total knee arthroplasty (TKA), this benign-appearing connective tissue hyperplasia can cause significant disability among patients because the concomitant knee pain and restricted range of motion severely hinder postoperative rehabilitation, clinical outcomes, and basic activities of daily living. The most effective management for arthrofibrosis in the setting of TKA is prevention, including preoperative patient education programs, aggressive postoperative physical therapy regimens, and anti-inflammatory medications. Operative treatments include manipulation under anesthesia, arthroscopic debridement, and quadricepsplasty.

BACKGROUND:While tranexamic acid (TXA) has been well shown to reduce blood loss after joint replacement surgery, little is known regarding its effectiveness in obese patients. The aim of this study was to evaluate the effect of TXA changes in hematocrit and hemoglobin levels as well as incidence of packed red blood cell (pRBC) transfusions in obese patients undergoing total joint arthroplasty (TJA). MATERIAL AND METHODS/METHODS:Between January 2014 and May 2015, 420 consecutive primary joint replacements were performed by two surgeons at our institution. One-hundred-fifty-seven patients (total hip arthroplasty [THA]=29; total knee arthroplasty [TKA]=128) were obese with a body mass index (BMI) greater than or equal to 30 kg/m2. Medical records were reviewed and identified that TXA was utilized in 85 (54.1%) arthroplasties (study group) and was compared to a consecutive series of 72 (45.9%) TJAs (control group). TXA was given intravenously (IV) in two doses: (1) one gram prior to incision and (2) one gram at the time of femoral preparation in THA or prior to cementation in TKA. Changes in hemoglobin and hematocrit levels, number of pRBC transfusions, and occurrence of thrombolytic events were recorded. RESULTS:The changes in hematocrit (7.2% vs. 8.1%) and hemoglobin levels (3.0 g/dl vs. 3.3 g/dl) were less in the group that received TXA than the control group, albeit not significantly (p=0.100 and p=0.278, respectively). Within the control group, 26 (36.1%) patients required a pRBC transfusion with a mean of 2.0 units per patient (range:1-5); whereas, only eight (9.4%) patients with TXA required a mean of 1.6 units per patient (range: 1-2). The use of TXA significantly reduced the incidence of pRBC transfusions, especially in TKA (p<0.001). Sub-analyses revealed that transfusion rates were even more significantly reduced by TXA in obesity type II and III. Two pulmonary emboli were reported in the group that did not receive TXA; whereas, no thrombolytic events were reported in the group that did receive TXA. CONCLUSION/CONCLUSIONS:Utilization of TXA significantly reduced the rate of pRBC transfusions in obese patients.

The original architects of Medicare modeled the payment system on the existing fee-for-service (FFS) structure that historically dominated the health-insurance market. Under the FFS paradigm, health-care expenditures experienced an exponential rise. In response, the managed care and capitation models of health-care delivery were developed. However, changes in Medicare reimbursement, along with an increasing volume of orthopaedic procedures and escalating implant costs, call into question the cost-effectiveness of this service line. The success of the Medicare Acute Care Episode (ACE) Demonstration Project proved the feasibility of value-based care and ushered in a new era of bundled payment initiatives.

The purpose of this study was to determine if there is a difference in the number of diagnostic tests and interventions, pain and function scores, or satisfaction of patients discharged to inpatient rehabilitation facilities vs to home. From February to May 2015, 171 consecutive patients were prospectively recruited following primary total knee arthroplasty. Six weeks postoperatively, based on the patients' recollections, the number and types of diagnostic imaging tests, number of blood transfusions, and overall satisfaction whether discharged to inpatient rehabilitation facilities (n=85) or to home (n=86) were assessed. A significantly greater proportion of patients discharged to inpatient rehabilitation facilities reported undergoing at least 1 diagnostic imaging test compared with patients discharged to home (25.9% vs 8.1%; P=.013). Multivariate logistic regressions revealed that patients discharged to an inpatient rehabilitation facility were more likely to have a greater number of diagnostic tests (odds ratio, 5.01; 95% confidence interval, 1.69-14.92; P=.004) and radiographs (odds ratio, 16.10; 95% confidence interval, 1.54-169.70; P=.020) performed. There was no significant difference in readmission rates for patients discharged to home (2.3%) vs to an inpatient rehabilitation facility (0%) (P=.246). No significant differences were observed in postoperative Knee Society pain or function scores (P=.083 and P=.057, respectively) or visual analog scale satisfaction scores (P=.206). Twenty-nine (34.1%) patients were discharged under the care of the visiting nurse service after leaving the rehabilitation facility. Patients discharged to an inpatient rehabilitation facility underwent more diagnostic testing, especially radiographs, than patients discharged to home. There were no clinically relevant differences in Knee Society pain or function scores or patient satisfaction. [Orthopedics. 201x; xx(x):xx-xx.].