Faculty Bibliography

Cement fixation of the femoral stem in total hip arthroplasty, first popularized in the 1960s following the success of Sir John Charnley's design, remains a prevalent topic in arthroplasty literature today. Though this technique is still widely used among European surgeons, since the 1980s many American surgeons have shifted to the use of cementless, press-fit stems except for particular cases such as those at increased risk for periprosthetic fracture. In this article we review the history and literature regarding the use of cemented stems in total hip arthroplasty in the United States and Europe over the past 70 years.

BACKGROUND:Vancomycin is often used as antimicrobial prophylaxis in patients undergoing total hip or knee arthroplasty. Vancomycin requires longer infusion times to avoid associated side effects. We hypothesized that vancomycin infusion is often started too late and that delayed infusion may predispose patients to increased rates of surgical site infections and prosthetic joint infections. METHODS:We reviewed clinical data for all primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) patients at our institution between 2013 and 2020 who received intravenous vancomycin as primary perioperative gram-positive antibiotic prophylaxis. We calculated duration of infusion before incision or tourniquet inflation, with a cutoff of 30 minutes defining adequate administration. Patients were divided into two groups: 1) appropriate administration and 2) incomplete administration. Surgical factors and quality outcomes were compared between groups. RESULTS:We reviewed 1047 primary THA and TKA patients (524 THAs and 523 TKAs). The indication for intravenous vancomycin usage was allergy (61%), methicillin-resistant staphylococcus aureus colonization (17%), both allergy and colonization (14%), and other (8%). 50.4% of patients began infusion >30 minutes preoperatively (group A), and 49.6% began infusion <30 minutes preoperatively (group B). Group B had significantly higher rates of readmissions for infectious causes (3.6 vs 1.3%, P = .017). This included a statistically significant increase in confirmed prosthetic joint infections (2.2% vs 0.6%, P = .023). Regression analysis confirmed <30 minutes of vancomycin infusion as an independent risk factor for PJI when controlling for comorbidities (OR 5.22, P = .012). CONCLUSION/CONCLUSIONS:Late infusion of vancomycin is common and associated with increased rates of infectious causes for readmission and PJI. Preoperative protocols should be created to ensure appropriate vancomycin administration when indicated.

BACKGROUND:Dual mobility (DM) total hip arthroplasty (THA) implants have been advocated for patients at risk for impingement due to abnormal spinopelvic mobility. Impingement against cobalt-chromium acetabular bearings, however, can result in notching of titanium femoral stems. This study investigated the incidence of femoral stem notching associated with DM implants and sought to identify risk factors. METHODS:A multicenter retrospective study reviewed 256 modular and 32 monoblock DM components with minimum 1-year clinical and radiographic follow-up, including 112 revisions, 4 conversion THAs, and 172 primary THAs. Radiographs were inspected for evidence of femoral notching and to calculate acetabular inclination and anteversion. Revisions and dislocations were recorded. RESULTS:Ten cases of femoral notching were discovered (3.5%), all associated with modular cylindrospheric cobalt-chromium DM implants (P = .049). Notches were first observed radiographically at mean 1.3 years after surgery (range 0.5-2.7 years). Notch location was anterior (20%), superior (60%), or posterior (20%) on the prosthetic femoral neck. Notch depth ranged from 1.7% to 20% of the prosthetic neck diameter. Eight cases with notching had lumbar pathology that can affect spinopelvic mobility. None of these notches resulted in stem fracture, at mean 2.7-year follow-up (range 1-7.6 years). There were no dislocations or revisions in patients with notching. CONCLUSION/CONCLUSIONS:Femoral notching was identified in 3.5% of DM cases, slightly surpassing the dislocation rate in a cohort selected for risk of impingement and instability. Although these cases of notching have not resulted in catastrophic failures thus far, further study of clinical sequelae is warranted. Component position, spinopelvic mobility, and implant design may influence risk.

BACKGROUND:Opioids have played an important part in post-operative analgesia, but concerns with associated morbidity and the fate of leftover pills have prompted the creation of opioid-sparing protocols. The purpose of this study is to investigate the impact of the implementation of an opioid-sparing protocol on survey-based patient satisfaction scores following total hip arthroplasty (THA). METHODS:This study is a retrospective review of prospectively collected data on patients who underwent primary THA between November 2014 and July 2019. Inclusion criteria consisted of primary elective THA with complete Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey information. Cohorts were separated based on their date of surgery relative to the start of an institutional opioid-sparing-protocol in October 2018. Discharge prescriptions and refills were recorded on chart review and converted to milligram morphine equivalents (MME) for comparison between different opioids. HCAHPS results were analyzed for percentage of "top box" ratings for comparison between the 2 groups. RESULTS:In total, 1003 patients met inclusion criteria: 804 pre-protocol and 199 post-protocol. Mean length of stay decreased from 1.74 ± 1.03 to 1.50 ± 1.11 days (P < .001). Pre-operative Visual Analog Scale pain decreased from 7.00 ± 2.30 to 6.41 ± 2.66 (P = .011) as did the rate of opioid refills (15.6%-9.1%; P = .019). Quantity of opioid medication prescribed upon discharge also decreased from 432 ± 298 to 114 ± 156 MME (P < .001). There was no change in "top box percentages" for satisfaction with pain control (79.7% pre-protocol, 82.1% post-protocol; P = .767). There was a significant increase in proportion of patients reporting top box satisfaction with their overall surgical experience after protocol implementation (88.2%-94.0%; P = .018). CONCLUSION/CONCLUSIONS:A reduction in opioids prescribed after THA is not associated with a decrease in patient satisfaction with regard to pain control, as measured by the HCAHPS survey, nor is it associated with an increase in post-operative opioid refills. LOE: III. CLINICAL RELEVANCE/CONCLUSIONS:This study suggests that HCAHP scores are not negatively impacted by a reduction in post-operative opioid analgesics.

BACKGROUND:There is debate regarding the benefit of liposomal bupivacaine (LB) as part of a periarticular injection (PAI) in total hip arthroplasty (THA). Here, we evaluate the effect of discontinuing intraoperative LB PAI on immediate postoperative subjective pain, opioid consumption, and objective functional outcomes. METHODS:On July 1, 2019, an institutional policy discontinued the use of intraoperative LB PAI. A consecutive cohort that received LB PAI and a subsequent cohort that did not were compared. All patients received the same opioid-sparing protocol. Nursing documented verbal rating scale pain scores were averaged per patient per 12-hour interval. Opiate administration events were converted into morphine milligram equivalences per patient per 24-hour interval. The validated Activity Measure for Postacute Care (AM-PAC) tool was used to evaluate functional outcomes. RESULTS:Six hundred thirty eight primary THAs received LB followed by 939 that did not. In the non-LB THAs, BMI was higher (30.06 vs 29.43; P < .05). Besides marital status, the remaining baseline demographics were similar between the two cohorts (P > .05). The non-LB THA cohort demonstrated a marginal increase in verbal rating scale pain scores between 12 to 24 hours (4.42 ± 1.70 vs 4.20 ± 1.87; P < .05) and 36 to 48 hours (4.49 ± 1.72 vs 4.21 ± 1.83; P < .05). There was no difference in inpatient opioid administration up to 96 hours postoperatively (P > .05) or AM-PAC functional scores within the first 24 hours (P > .05). CONCLUSION/CONCLUSIONS:A small statistical, but not clinically meaningful, difference was observed in subjective pain scores with LB PAI discontinuation. Opioid consumption and postoperative AM-PAC functional scores were unchanged after LB PAI discontinuation.

BACKGROUND:The use of perioperative adductor canal blocks (PABs) continues to be a highly debated topic for total knee arthroplasty (TKA). Here, we evaluate the effect of PABs on immediate postoperative subjective pain scores, opioid consumption, and objective functional outcomes. METHODS:On December 1, 2019, an institution-wide policy change was begun to use PABs in primary elective TKAs. Patient demographics, immediate postoperative nursing documented pain scores, opioid administration events, and validated physical therapy functional scores were prospectively collected as part of the standard of care and retrospectively queried through our electronic data warehouse. A historical comparison cohort was derived from consecutive patients undergoing TKA between July 1, 2019 and November 30, 2019. RESULTS:405 primary TKAs received PABs, while 789 patients were in the control cohort. Compared with controls, average verbal rating scale pain scores were lower among PAB recipients from 0-12 hours (2.42 ± 1.60 vs 2.05 ± 1.60; <.001) and 24-36 hours (4.92 ± 2.00 vs 4.47 ± 2.27; <.01). PAB recipients demonstrated significantly lower opioid consumption within the first 24 hours (44.34 ± 40.98 vs 36.83 ± 48.13; P < .01) and during their total inpatient stay (92.27 ± 109.81 vs 77.52 ± 123.11; <.05). AM-PAC scores within the first 24 hours were also higher for PABs (total scores: 20.28 ± 3.06 vs 20.71 ± 3.12; <.05). CONCLUSION/CONCLUSIONS:While the minimal clinically important differences in pain scores and functional status were comparable between both cohorts, patients demonstrated a significant reduction in overall inpatient opiate consumption after the introduction of PABs. Surgeons should consider these findings when evaluating for perioperative pain management, opioid-sparing, and rapid discharge protocols.

AIMS/OBJECTIVE:Liposomal bupivacaine (LB) as part of a periarticular injection protocol continues to be a highly debated topic in total knee arthroplasty (TKA). We evaluated the effect of discontinuing the use of LB in a periarticular protocol on immediate postoperative pain scores, opioid consumption, and objective functional outcomes. METHODS:On 1 July 2019, we discontinued the use of intraoperative LB as part of a periarticular injection protocol. A consecutive group of patients who received LB as part of the protocol (Protocol 1) and a subsequent group who did not (Protocol 2) were compared. All patients received the same opioid-sparing protocol. Verbal rating scale (VRS) pain scores were collected from our electronic data warehouse and averaged per patient per 12-hour interval. Events relating to the opiate administration were derived as morphine milligram equivalences (MMEs) per patient per 24-hour interval. The Activity Measure for Post-Acute Care (AM-PAC) tool was used to assess the immediate postoperative function. RESULTS:A total of 888 patients received Protocol 1 and while 789 received Protocol 2. The mean age of the patients was significantly higher in those who did not receive LB (66.80 vs 65.57 years, p = 0.006). The sex, BMI, American Society of Anesthesiologists physical status score, race, smoking status, marital status, operating time, length of stay, and discharge disposition were similar in the two groups. Compared with the LB group, discontinuing LB showed no significant difference in postoperative VRS pain scores up to 72 hours (p > 0.05), opioid administration up to 96 hours (p > 0.05), or AM-PAC scores within the first 24 hours (p > 0.05). CONCLUSION/CONCLUSIONS: 2021;103-B(6 Supple A):102-107.

Isolated lateral compartment osteoarthritis of the knee is a rare condition affecting approximately 1% of the population, which is ten times less common than osteoarthritis affecting only the medial compartment. Unicompartmental knee arthroplasty (UKA) has many potential advantages over total knee arthroplasty. The benefits of UKA include a smaller incision, preservation of more native tissue (including cruciate ligaments and bone), decreased blood loss, and better overall proprioception. When UKA was first introduced in the 1970s, the outcomes of medial UKA (MUKA) were poor, but the few cases of lateral UKA (LUKA) showed promise. Since that time, there has been a relative paucity of literature focused specifically on LUKA given it is a rare procedure. Refinements in patient selection criteria, implant design, and surgical technique have been made leading to increased popularity. A review of the recent literature reveals that LUKA is associated with excellent long-term clinical outcomes and implant survivorship when performed in properly selected patients. Implant design options include fixed vs mobile bearing as well as metal backed vs all polyethylene tibial component, with improved outcomes noted with fixed bearing designs. Three reasons cited for revision (i.e., fracture of the femoral component, fracture of the tibial component, and valgus malalignment) had been reported in past literature but not recently. Presently, while rare, the most common cause of failure and need for revision are osteoarthritis progression and aseptic loosening. Despite the need for an occasional revision procedure, the survivorship of LUKA is comparable to MUKA, although it should be noted that outcomes of MUKA have been notably varied. Continued pursuit of improved techniques and implant designs will continue to show LUKA to be an excellent procedure for appropriately indicated patients.

Background/UNASSIGNED:Failure of cementless acetabular osseointegration is rare in total hip arthroplasty. Nevertheless, new fixation surfaces continue to be introduced. Novel implants may lack large diameter, constrained bearings, or dual mobility (DM) bearings to address instability. We compared clinical and radiographic outcomes for acetabular components with differing fixation surfaces and bearing options, focusing on the relationship between fixation surface and osseointegration and the relationship between bearing options and dislocation rate. Methods/UNASSIGNED:We retrospectively reviewed 463 total hip arthroplasties implanted with 3 different acetabular components between 2012 and 2016. Records were reviewed for demographics, clinical scores, and complications. Radiographs were examined for evidence of acetabular osteointegration. Analysis of variance and chi-square tests were used to compare cohorts. Results/UNASSIGNED:All cohorts had 100% survivorship free of acetabular fixation failure with no differences in clinical scores. Dislocation occurred in 1.3% of cases (n = 6). Analysis of the "transition" sizes, for which brand determined the maximum bearing diameter, revealed a significantly higher dislocation rate (3/50, 6%) in implants with limited bearing options. All 4 revisions for recurrent dislocation involved well-positioned components that did not accept large diameter, constrained bearings, or DM bearings, resulting in 3 shell revisions to expand bearing options. Femoral revisions were associated with dislocation risk but did not vary between cohorts. Conclusion/UNASSIGNED:Dislocation was the primary mechanical cause for acetabular revision, while acetabular fixation failure was not encountered. We caution against selecting "new and improved" acetabular components without options for large diameter, constrained bearings, or DM bearings, even when enabling technology makes component positioning reliable.