Faculty Bibliography

Total joint arthroplasty relies on the use of biomaterials that are biologically inert and capable of forming wear-resistant articulating surfaces. Polyethylene use in arthroplasty has become ubiquitous since its introduction in the 1960s. Early arthroplasty procedures of the hip utilized poly-tetra-flouroethylene, or "Teflon," due to its low coefficient of friction that was presumed to closely mimic the hyaline cartilage of native joints. Early catastrophic wear of Teflon caused a significant local tissue reaction contributing to osteolysis, aseptic loosening, and clinical failure ultimately limiting the material's surgical utility. Advancements in biomaterial synthesis and processing led to the fortuitous discovery of ultra-high-molecular-weight-polyethylene (UHMWPE) and the eventual evolution to highly cross-linked polyethylene (HXLPE) as a bearing surface in hip arthroplasties with robust, long-term clinical success. Ultra-high-molecularweight-polyethylene was readily adopted for use in total knee arthroplasty following the material's successful use in hip replacement, however, the unique biomechanics of the knee have posed unique challenges. The use of HXLPE in knee arthroplasty has increased, however, clear data regarding its benefit over UHMWPE are conflicting. Recently, clinical as well as research and development studies of UHMWPE and HXLPE have focused on alternative postprocessing methods to optimize material stability and wear resistance. Second generation HXLPE utilizing sequential annealing processes or vitamin E to stabilize free radicals are promising means to improve mechanical stability and wear resistance for use in joint arthroplasty, however, more data is required to evaluate long-term outcomes and cost-effectiveness. In this review, we discuss the history and innovation of polyethylene use in orthopedic surgery and evaluate the current literature on outcomes of polyethylene use in hip and knee replacement.

INTRODUCTION/BACKGROUND:Previous studies have demonstrated that patients with positive preoperative urine toxicology (utox) screens prior to total joint arthroplasty (TJA) have higher readmission rates, greater complication rates, and longer hospital stays compared to patients with negative screens. The aim of this study was to investigate the effect of postponing surgery for patients with positive preoperative utox in the Medicaid population. METHODS:This retrospective, observational study reviewed the Medicaid ambulatory database at a large, academic orthopedic specialty hospital for patients with a utox screen prior to TJA from 2012 to 2020. Patients were categorized into three groups: (1) controls with negative preoperative utox or a utox consistent with prescription medications (Utox-) with TJA completed as scheduled; (2) positive preoperative utox with TJA rescheduled and surgery completed on a later date (R-utox+); (3) positive preoperative utox inconsistent with prescription medications with TJA completed as scheduled (S-utox+). Primary outcomes included mortality, 90-day readmission rate, complication rate, and length of stay. RESULTS:Of the 300 records reviewed, 185 did not meet inclusion criteria. The remaining 115 patients included 80 (69.6%) Utox-, 5 (6.3%) R-utox+, and 30 (37.5%) S-utox+. Mean follow-up time was 49.6 months. Hospital stays trended longer in the Utox- group (3.7 ± 2.0 days vs. 3.1 ± 1.6 S-utox+ vs.2.5 ± 0.4 R-utox+, p = 0.20). Compared to the R-utox+group, the S-utox+ group trended toward lower home discharge rates (p = 0.20), higher in-hospital complication rates (p = 0.85), and more all-cause 90-day emergency department visits (p = 0.57). There were no differences in postoperative opioid utilization between groups (p = 0.319). Duration of postoperative narcotic use trended toward being longer in the Utox- patients (820.7 ± 1073.8 days vs. 684.6 ± 1491.8 S-utox+ vs. 585.1 ± 948.3 R-utox+, p = 0.585). Surgical time (p = 0.045) and revision rates (p = 0.72) trended toward being higher in the S-utox+ group. CONCLUSIONS:Medicaid patients with positive preoperative utox who had surgeries postponed trended towards shorter hospital stays and greater home discharge rates. Larger studies should be conducted to analyze the implications of a positive preoperative utox on risk profiles and outcomes following TJA in the Medicaid population. Study design Retrospective cohort study.

The management of acetabular bone loss during revision arthroplasty is a challenging problem. Not only are there a wide variety of potential defects, but the location of these defects can also drastically change the hip center of rotation, stability, and biomechanics. First, the assessment of the severity and location of bone loss preoperatively is highlighted as it is imperative to evaluate the acetabular bone stock remaining. It is especially important to determine how to identify a pelvic discontinuity. Various classification systems are discussed to help surgeons adequately assess and evaluate these defects. There are also numerous implants and treatment strategies available to manage the problem, all of which are determined by that preoperative assessment and classification. We review the history of managing these defects and how management has evolved into modern designs, including but not limited to structural allograft, distraction arthroplasty, jumbo cups, metal augments, cup-cages, and custom triflanges. This review then describes the up-to-date clinical results of these various techniques, highlighting the surgical execution needed to obtain a successful result. By describing the preoperative assessment, the acetabular defect classifications, and proposed evidence-based treatment algorithms, we hope that this review will enhance the understanding of these challenging reconstructions in the setting of acetabular bone defects.

PURPOSE/OBJECTIVE:The purpose of the current study was to determine if differences exist between cruciate-retaining (CR) and posterior-stabilized (PS) implant articulations for total knee arthroplasty (TKA) with regards to early post-operative pain. METHODS:We retrospectively reviewed patients who underwent primary TKA, with the same TKA implant design, at our institution between January 2018 and July 2021. Patients were stratified based on whether they received a CR or non-constrained PS (PSnC) articulation and propensity score matched in a 1:1 ratio. A sub-analysis matching patient who received a constrained PS implant (PSC) to those undergoing CR TKA and PSnC TKA was also carried out. Opioid dosages were converted to morphine milligram equivalents (MME). RESULTS:616 patients after CR TKA were matched 1:1 to 616 patients with a PSnC implant. There were no significant differences between demographic variables. There were no statistically significant differences in opioid usage measured by MME on post-operative day (POD) 0 (p = 0.171), POD1 (p = 0.839), POD2 (p = 0.307), or POD3 (p = 0.138); VAS pain scores (p = 0.175); or 90-day readmission rate for pain (p = 0.654). A sub-analysis of CR versus PSC TKA demonstrated no significant differences in opioid usage on POD0 (p = 0.765), POD1 (p = 0.747), POD2 (p = 0.564), POD3 (p = 0.309); VAS pain scores (p = 0.293); and 90-day readmission rate for pain (p > 0.9). CONCLUSION/CONCLUSIONS:Our analysis demonstrated no significant difference in post-operative VAS pain scores and MME usage based on implant. The results suggest that neither the type of articulation or constraint used for primary TKA has a significant impact on immediate post-operative pain and opioid consumption. LEVEL III EVIDENCE/METHODS:Retrospective Cohort Study.

Background: National projections of future joint arthroplasties are useful in understanding the changing burden of surgery and related outcomes on the health system. The aim of this study is to update the literature by producing Medicare projections for revision total joint arthroplasty procedures from 2040 through 2060.
Method(s): The study uses 2000-2019 data from the CMS Medicare Part-B National Summary and combines procedure counts using CPT codes for revision total joint arthroplasty procedures. In 2019, revision total knee arthroplasty (rTKA) and revision total hip arthroplasty (rTHA) procedures totaled 53,217 and 30,541, respectively, forming a baseline from which we generated point forecasts between 2020 and 2060 and 95% forecast intervals (FI).
Result(s): On average, the model projects an annual growth rate of 1.77% for rTHAs and 4.67% for rTKAs. By 2040, rTHAs were projected to be 43,514 (95% FI = 37,429-50,589) and rTKAs were projected to be 115,147 (95% FI = 105,640-125,510). By 2060, rTHAs was projected to be 61,764 (95% FI = 49,927-76,408) and rTKAs were projected to be 286,740 (95% FI = 253,882-323,852).
Conclusion(s): Based on 2019 total volume counts, the log-linear exponential model forecasts an increase in rTHA procedures of 42% by 2040 and 101% by 2060. Similarly, the estimated increase for rTKA is projected to be 149% by 2040 and 520% by 2060. An accurate projection of future revision procedure demands is important to understand future healthcare utilization and surgeon demand. This finding is only applicable to the Medicare population and demands further analysis for other population groups.
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BACKGROUND:This multicenter randomized controlled trial evaluated if dual-mobility bearings (DM) lower the risk of dislocation compared to large femoral heads (≥36 mm) for patients undergoing revision total hip arthroplasty (THA) via a posterior approach. METHODS:A total of 146 patients were randomized to a DM (n = 76; 46 mm median effective head size, range 36 to 59 mm) or a large femoral head (n = 70; twenty-five 36 mm heads [35.7%], forty-one 40 mm heads [58.6%], and four 44 mm heads [5.7%]). There were 71 single-component revisions (48.6%), 39 both-component revisions (26.7%), 24 reimplantations of THA after 2-stage revision (16.4%), seven isolated head and liner exchanges (4.8%), four conversions of hemiarthroplasty (2.7%), and 1 revision of a hip resurfacing (0.7%). Power analysis determined that 161 patients were required in each group to lower the dislocation rate from 8.4 to 2.2% (power = 0.8, alpha = 0.05). RESULTS:At a mean of 18.2 months (range, 1.4 to 48.2), there were three dislocations in the large femoral head group compared to two in the DM cohort (4.3 versus 2.6%; P = .67). One patient in the large head group and none in the DM group were successfully treated with closed reduction without subsequent revision. CONCLUSION/CONCLUSIONS:Interim analysis of this randomized controlled trial found no difference in the risk of dislocation between DM and large femoral heads in revision THA, although the rate of dislocation was lower than anticipated and continued follow-up is needed.

Larsen syndrome is a rare genetic disorder characterized by weak connective tissues and various musculoskeletal abnormalities. This is a case report of a 39-year-old patient with Larsen syndrome who presented with over a decade of bilateral hip pain and difficulty ambulating. This patient has a prior history of bilateral congenital hip dislocations that were treated with open reduction and spica casting as a child with good result. Years later, she went on to develop bilateral hip osteoarthritis with significant remodeling of the proximal femur. The goal of this case presentation is to demonstrate the utility of total hip arthroplasty for this patient and discuss surgical challenges and considerations.

INTRODUCTION/BACKGROUND:Infection after total knee arthroplasty (TKA) impacts the patient, surgeon, and healthcare system significantly. Surgeons routinely use antibiotic-loaded bone cement (ALBC) in attempts to mitigate infection; however, little evidence supports the efficacy of ALBC in reducing infection rates compared to non-antibiotic-loaded bone cement (non-ALBC) in primary TKA. Our study compares infection rates of patients undergoing TKA with ALBC to those with non-ALBC to assess its efficacy in primary TKA. METHODS:A retrospective review of all primary, elective, cemented TKA patients over the age of 18 between 2011 and 2020 was conducted at an orthopedic specialty hospital. Patients were stratified into two cohorts based on cement type: ALBC (loaded with gentamicin or tobramycin) or non-ALBC. Baseline characteristics and infection rates determined by MSIS criteria were collected. Multilinear and multivariate logistic regressions were performed to limit significant differences in demographics. Independent samples t test and chi-squared test were used to compare means and proportions, respectively, between the two cohorts. RESULTS:) and Charlson Comorbidity Index values (4.51 ± 2.15 vs. 4.04 ± 1.92) were more likely to receive ALBC. The infection rate in the non-ALBC was 0.8% (63/7,980), while the rate in the ALBC was 0.5% (7/1,386). After adjusting for confounders, the difference in rates was not significant between the two groups (OR [95% CI]: 1.53 [0.69-3.38], p = 0.298). Furthermore, a sub-analysis comparing the infection rates within various demographic categories also showed no significant differences between the two groups. CONCLUSION/CONCLUSIONS:Compared to non-ALBC, the overall infection rate in primary TKA was slightly lower when using ALBC; however, the difference was not statistically significant. When stratifying by comorbidity, use of ALBC still showed no statistical significance in reducing the risk of periprosthetic joint infection. Therefore, the advantage of antibiotics in bone cement to prevent infection in primary TKA is not yet elucidated. Further prospective, multicenter studies regarding the clinical benefits of antibiotic use in bone cement for primary TKA are warranted.

BACKGROUND:Concerns regarding the effects of dexamethasone on diabetics' glucose control have stymied its use following total joint arthroplasty. This study aimed to evaluate the effects of 2 intravenous (IV) perioperative doses of dexamethasone on glucose levels, pain scores, and inpatient opioid consumption following total joint arthroplasty in diabetic patients. METHODS:A retrospective review of 523 diabetic patients who underwent primary elective THA and 953 diabetic patients who underwent primary elective total knee arthroplasty (TKA) between May 6, 2020, and December 17, 2021 was conducted. Patients who received 1 dose (1D) of perioperative dexamethasone 10 mg IV were compared to patients who received 2 doses (2D). Primary outcomes included postoperative glucose levels, opioid consumption as morphine milligram equivalences, postoperative pain as Verbal Rating Scale pain scores, and postoperative complications. RESULTS:The 2D TKA cohort had significantly greater average and maximum blood glucose levels from 24 to 60 hours compared to the 1D TKA cohort. The 2D THA cohort had significantly greater average blood glucose levels at 24 to 36 hours compared to the 1D THA cohort. However, the 2D TKA group had significantly reduced opioid consumption from 24 to 72 hours and reduced total consumption compared to the 1D TKA group. Verbal Rating Scale pain scores did not differ between cohorts for both TKA and THA at any interval. CONCLUSION/CONCLUSIONS:Administration of a second perioperative dose of dexamethasone was associated with increased postoperative blood glucose levels. However, the observed effect on glucose control may not outweigh the clinical benefits of a second perioperative dose of glucocorticoids.

BACKGROUND:Intra-articular hyaluronic acid (IAHA) has been commonly used in the management of knee osteoarthritis (OA). This study sought to assess patient-reported outcomes (PRO) following different formulations of hyaluronic acid injections for patients who have knee OA. METHODS:A retrospective analysis was performed on patients who have knee OA and received IAHA knee injections from October 2018 to May 2022 in sports medicine (SM) and adult reconstructive (AR) clinics. Patients completed PRO measures including the Patient-Reported Outcome Measurement Information System (PROMIS) Mobility, Pain Interference, and Pain Intensity at baseline, 6-week, 6-month, and 12-month follow-up. Univariate and multivariate analyses were used to evaluate changes in PRO measures between baseline and follow-up periods and to evaluate differences between the SM and AR divisions. A total of 995 patients received IAHA for knee OA and completed PRO assessments. RESULTS:There was no difference in the PROMIS measures based on molecular weight at 6 weeks, 6 months, and 12 months. Except for 6-month Mobility scores between the SM and AR patients (-0.52 ± 5.46 versus 2.03 ± 6.95; P = .02), all other PROMIS scores were similar. Mobility scores at 6 months were significantly different based on Kellgren and Lawrence grade (P = .005), but all other PROMIS scores were similar. CONCLUSION/CONCLUSIONS:Average change in PROMIS scores were significantly different only for 6-month Mobility scores based on divisions and Kellgren and Lawrence grade but did not achieve minimally clinical important difference at most timepoints. Further studies are needed to investigate whether improvement is observed in specific patient populations.