Pericapsular Nerve Group Block Did Not Reduce Postoperative Pain or Opioid Use After Total Hip Arthroplasty.

BACKGROUND: The pericapsular nerve group (PENG) block is a newly developed regional anesthesia technique designed to manage postoperative hip pain following a fracture or surgery while also maintaining quadriceps strength and mobility. The goal of our study was to compare postoperative pain scores and opioid usage during the postoperative period before discharge following total hip arthroplasty (THA) using the posterior approach between patients who received a PENG block and those who did not. METHODS: We conducted a retrospective study on patients undergoing elective, posterior approach THA at a single tertiary-care academic center. The 2 groups included a study group (THA with PENG block in 2021; n = 66) and a control group (THA before PENG block implementation in 2019; n = 70). RESULTS: There were no significant differences in pain scores during postoperative minutes 0 to 59 (study group 6.8; control group 6.6; P = .81) or during postoperative minutes 60 to 119 (study group 6.2; control group 5.6; P = .40). There were no significant differences in total postoperative in-hospital morphine milliequivalent opioid consumption (study group 55.8 morphine milligram equivalents; control group 75.0 morphine milligram equivalents; P = .14). The study group was found to have a shorter length of stay (study group 17.0 hours; control group 32.6 hours; P < .0001) and faster mobilization (study group 3.0 hours; control group 4.9 hours; P < .0001) than the control group. CONCLUSIONS: Our results show that use of the PENG block did not result in lower postoperative pain scores or opioid consumption after THA using the posterior surgical approach. The study group had a shorter length of stay and time to mobilization than the control group, though this was likely due to standard hospital procedure shifting to same-day discharge for THA between 2019 and 2021 due to COVID-19.

Highlights of the 2023 American Joint Replacement Registry Annual Report.

The 2023 report represents a full decade of published annual reports of the American Joint Replacement Registry (AJRR). The number of cases being captured continues to rapidly grow, as are over 3.2 million patients included in AJRR. Matched-pair primary and revision data is more robust with 10-year survivorship being available. Similarly, implant-specific survivorship has been included for common implants being used in the United States. The data mined from the AJRR have led to numerous publications and presentations. Numerous trends have emerged, and others have been reinforced with the most recent data. The authors encourage readers to more thoroughly review the full report at the following link: https://www.aaos.org/registries/publications/ajrr-annual-report/.

Functional Articulating Antibiotic Spacers for Chronic Native Septic Knee Arthritis.

Background: Semipermanent functional spacers are now utilized for prosthetic joint infection in an attempt to avoid another surgery with 2-stage treatment. This study evaluates the results of metal-on-polyethylene articulating spacers for the treatment of chronic native septic knee arthritis. Methods: This is a retrospective review of 18 patients treated with metal-on-polyethylene articulating antibiotic spacers constructed with all-polyethylene tibial components or with polyethylene inserts (PIs) with Steinmann pins or screws for chronic native knee infection. Demographic information, spacer construct type, prior knee surgery, complications, infecting organisms, infection eradication, and functional results were analyzed. Results: Of 18, 8 (44%) spacers were all-polyethylene tibial components and 10 (56%) were PI. Of 18 patients, 5 (28%) experienced spacer complications. Of 18 patients, 12 (67%) underwent a second reimplantation surgery (mean 106 days), while 6 (33%) retained their spacer (average duration 425 days). The PI group performed better in Knee Injury and Osteoarthritis Outcome score for Joint Replacement according to minimum clinically important difference and patient acceptable symptom state (PASS) criteria. The overall reimplantation group achieved Knee Injury and Osteoarthritis Outcome score for Joint Replacement PASS criteria and minimum clinically important difference criteria, while the maintained articulating spacer group did not achieve PASS criteria; however, they did reach minimum clinically important difference. Conclusions: Functional articulating spacers are a viable treatment for chronic, native knee septic arthritis. The PI patient group had a greater improvement in Knee Injury and Osteoarthritis Outcome score for Joint Replacement scores and had no significant difference in reimplantation rate as the all-polyethylene tibial components patient group. Both planned 2-stage reimplantation and longer-term spacer retention show promising results for this difficult clinical problem.

The Use of General Anesthesia in Revision Joint Arthroplasty.

BACKGROUND: Several studies have suggested that spinal anesthesia gives superior outcomes for primary total joint arthroplasty (TJA). However, there is a lack of available data regarding contemporary general anesthesia (GA) approaches for revision TJA utilized at high-volume joint arthroplasty centers. METHODS: We retrospectively reviewed a series of 850 consecutive revision TJAs (405 revision total hip arthroplasties and 445 revision total knee arthroplasties) performed over 4 years at a single institution that uses a contemporary GA protocol and reported on the lengths of stay, early recovery rates, perioperative complications, and readmissions. RESULTS: Of the revision arthroplasty patients, 74.4% (632 of 850) were discharged on postoperative day 1 and 68.5% (582 of 850) of subjects were able to participate in physical therapy on the day of surgery. Only 6 patients (0.7%) required an intensive care unit stay postoperatively. The 90-day readmission rate over this time was 11.3% (n = 96), while the reoperation rate was 9.4% (n = 80). CONCLUSIONS: While neuraxial anesthesia is commonly preferred when performing revision TJA, we have demonstrated favorable safety and efficiency metrics utilizing GA in conjunction with contemporary enhanced recovery pathways. Our data support the notion that modern GA techniques can be successfully used in revision TJA.

Single-cell Transcriptome Analysis Identifies Senescent Osteocytes as Contributors to Bone Destruction in Breast Cancer Metastasis.

Breast cancer bone metastases increase fracture risk and are a major cause of morbidity and mortality among women. Upon colonization by tumor cells, the bone microenvironment undergoes profound reprogramming to support cancer progression that disrupts the balance between osteoclasts and osteoblasts, leading to bone lesions. Whether such reprogramming affects matrix-embedded osteocytes remains poorly understood. Here, we demonstrate that osteocytes in breast cancer bone metastasis develop premature senescence and a distinctive senescence-associated secretory phenotype (SASP) that favors bone destruction. Single-cell RNA sequencing identified osteocytes from mice with breast cancer bone metastasis enriched in senescence and SASP markers and pro-osteoclastogenic genes. Using multiplex in situ hybridization and AI-assisted analysis, we detected osteocytes with senescence-associated distension of satellites, telomere dysfunction, and p16Ink4a expression in mice and patients with breast cancer bone metastasis. In vitro and ex vivo organ cultures showed that breast cancer cells promote osteocyte senescence and enhance their osteoclastogenic potential. Clearance of senescent cells with senolytics suppressed bone resorption and preserved bone mass in mice with breast cancer bone metastasis. These results demonstrate that osteocytes undergo pathological reprogramming by breast cancer cells and identify osteocyte senescence as an initiating event triggering bone destruction in breast cancer metastases.

An Updated Estimate of Total Hip and Total Knee Arthroplasty Inpatient Case Volume During the 2020 COVID-19 Pandemic in the United States.

Background: Inpatient total hip arthroplasty (THA) and total knee arthroplasty (TKA) practices were dramatically affected in the United States in 2020 as elective surgeries were paused in response to the COVID-19 pandemic. This study sought to provide an updated estimate of inpatient total joint arthroplasty (TJA) case volumes in the United States in 2020. Methods: A retrospective cohort study was performed by identifying all adult patients who underwent primary, elective TJA from January 1st, 2017 to December 31st, 2020, using the National Inpatient Sample. Monthly and annual case volumes were reported with descriptive statistics. Baseline case volumes were established by taking the average number of monthly cases performed in 2017, 2018, and 2019. These monthly averages were compared to 2020 values. Results: From 2017 to 2019, the average case volume was 1,056,669 cases per year (41.0% THA, 59.0% TKA) and 88,055 cases per month. In 2020, 535,441 cases were identified (45.4% THA, 54.6% TKA), corresponding to a 49.3% reduction from the 2017-2019 annual average. Monthly cases decreased to 4515 in April during the "first wave" of COVID-19, corresponding to a 94.8% decrease from prior years. In June, cases rebounded to 55,520 before decreasing again in July to 50,100 during the "second wave" of COVID-19. During the "third wave," COVID-19 cases decreased month-over-month from October through December (56.5% decrease). Conclusions: This updated estimate identified a 49.3% decrease in inpatient TJA cases in 2020 compared to prior years. This is similar to the 46.5-47.7% decrease in case volume previously reported.

Successful Transition to Same Calendar Day Discharge in Total Joint Arthroplasty at an Academic Center.

Background: There has been a shift toward same-day discharge (SDD) in total joint arthroplasty (TJA) in recent years. Our clinical standard had been next-day discharge, but the COVID pandemic led to a hospital bed shortage, causing us to shift to SDD directly from the Post-Anesthesia Care Unit (PACU). The aim of our project was to investigate if the SDD protocol was successful and if it changed complications or 90-day readmission rates. Our secondary aim was to investigate if the protocol created disparities in patient selection. Methods: A retrospective review compared the first 100 patients intended to discharge from PACU to the 100 patients prior to the SDD protocol undergoing elective primary TJA procedures at our academic institution from September 1, 2020, to March 23, 2021. The SDD protocol started on November 19, 2020. Results: During this SDD period, 98% (98/100) of patients were successfully discharged from the PACU. The 90-day readmission rate changed from 0% to 2% (P = .4975), and the overall complication rate changed from 2% to 5% (P = .4448). Most complications were manipulation under anesthesia to improve range of motion. Manipulations under anesthesia changed from 1% to 4% (P = .3687). Conclusions: The transition to same SDD in TJA at our academic institution was successfully implemented without markedly increasing complications, readmissions, or changing patient selection. The COVID-19 pandemic likely influenced the recovery of patients before and after the protocol. Future studies are needed to validate this data during the post-COVID era.

Robotic Total Knee Arthroplasty Surgeon Marketing: Do Claims Align With the Literature?

Background: Robotic total knee arthroplasty (R-TKA) utilization and marketing continue to rise. We examined the marketing on surgeon websites regarding R-TKA benefits and sought to determine if the claims were supported by existing literature. Methods: A Google search identified 10 physician websites from each of the 5 largest U.S. markets by population with the term "robotic total knee arthroplasty city, state." Claims on websites about R-TKA were categorized. Literature from 2012-2022 was reviewed for data "for" or "against" each claim. Level of evidence for each publication was collected. Results: Fifty websites were captured that included 59 surgeons. A specific R-TKA platform was mentioned on 68% of websites. Website claims about robotics were placed into 8 major categories. Literature review supported the claims of more precise/accurate, reduced injury to tissue, and less pain with more literature "for" than "against" the claims. Conclusions: Claims made on physician websites regarding the benefits of R-TKA are variable and not definitively supported by existing literature. Most available data can be categorized into levels of evidence III, IV, and V. There is a paucity of level I evidence to support the various marketing statements. Physicians should be cognizant of both the claims made on their websites and the literature that could be used to support or refute those specific claims.

Hospital-Wide Adherence to Postsurgical Opioid Prescribing Guidelines: A Retrospective Cohort Study.

INTRODUCTION: Lowering opioid prescription doses and quantity decreases the risk of chronic opioid usage. A tool was inserted into the brief operative note for the surgeon to assess the severity of pain associated with the procedure. We studied surgeon adherence to current opioid-prescribing recommendations. METHODS: Retrospective cohort study with 5486 patients were included in the study population. Each patient's prescription was scored yes or no for adherence on total morphine milligram equivalents (MMEs) and days prescribed with the selection in the brief operative note. The entire study population was tested for an increase from the null-hypothesis "benchmark" value of 75% using a one-sided exact binomial test of a single proportion with P < 0.05. This procedure was repeated for subgroups, with P < 0.01. RESULTS: Adherence to guidelines was higher than the 75% benchmark for "total MMEs prescribed" (79.5%; P < 0.001), but lower for "number of days prescribed" (63.5%; P > 0.999). Surgeries with severe predicted pain showed the highest adherence toward total MMEs prescribed at 87.1%, followed by moderate (80.5%) and mild (74.5%). Severe cases also showed the highest adherence in number of days prescribed (92.4%). Adherence to total MMEs prescribed was highest among attending physicians (88.1%) and lowest among residents/fellows (76.6%). CONCLUSIONS: Adherence to current guidelines was 79.5% for MMEs prescribed but only 63.5% for days prescribed. Compliance with guidelines was better for severe procedures than mild or moderate. Differences were seen across surgical departments. While an improvement from previous reports, further improvement is needed to reduce the number of days of opioids prescribed and increase compliance with recommended guidelines.

Does the type of lower extremity fracture affect long-term opioid usage? A meta-analysis.

INTRODUCTION:  Patients recovering from musculoskeletal trauma have a heightened risk of opioid dependence and misuse, as these medications are typically required for pain management. The purpose of this meta-analysis was to examine the association between fracture type and chronic opioid use following fracture fixation in patients who sustain lower extremity trauma. MATERIALS AND METHODS: A meta-analysis was performed using PubMed and Web of Science to identify articles reporting chronic opioid use in patients recovering from surgery for lower extremity fractures. 732 articles were identified using keyword and MeSH search functions, and 9 met selection criteria. Studies were included in the final analysis if they reported the number of patients who remained on opioids 6 months after surgery for a specific lower extremity fracture (chronic usage). Logistic regressions and descriptive analyses were performed to determine the rate of chronic opioid use within each fracture type and if age, year, country of origin of study, or pre-admission opioid use influenced chronic opioid use following surgery. RESULTS: Bicondylar and unicondylar tibial-plateau fractures had the largest percentage of patients that become chronic opioid users (29.7-35.2%), followed by hip (27.8%), ankle (19.7%), femoral-shaft (18.5%), pilon (17.2%), tibial-shaft (13.8%), and simple ankle fractures (2.8-4.7%).Most opioid-naive samples had significantly lower rates of chronic opioid use after surgery (2-9%, 95% CI) when compared to samples that allowed pre-admission opioid use (13-50%, 95% CI). There were no significant associations between post-operative chronic opioid use and age, year, or country of origin of study. CONCLUSIONS:  Patients with lower extremity fractures have substantial risk of becoming chronic opioid users. Even the lowest rates of chronic opioid use identified in this meta-analysis are higher than those in the general population. It is important that orthopedic surgeons tailor pain-management protocols to decrease opioid usage after lower extremity trauma.

Do Quality Measures or Hospital Characteristics Predict Readmission Penalties for Hip and Knee Arthroplasty?

BACKGROUND: Quality rating systems exist to grade the value of care provided by hospitals, but the extent to which these rating systems correlate with patient outcomes is unclear. The association of quality rating systems and hospital characteristics with excess readmission penalties for total hip arthroplasty (THA) and total knee arthroplasty (TKA) was studied. METHODS: The fiscal year 2022 Inpatient Prospective Payment System final rule was used to identify 2,286 hospitals subject to the Hospital Readmissions Reduction Program. Overall, 6 hospital quality rating systems and 5 hospital characteristics were obtained. These factors were analyzed to determine the effect on hospital penalties for THA and TKA excess readmissions. RESULTS: Hospitals that achieved a higher Medicare Overall Hospital Quality Star Rating demonstrated a significantly lower likelihood of receiving THA and TKA readmission penalties (Cramer's V = 0.236 and Rp = -0.233; P < .001 for both). Hospitals ranked among the US News & World Report's top 50 best hospitals for orthopaedics were significantly less likely to be penalized (V = 0.042; P = .043). The remaining 4 quality rating systems were not associated with readmission penalties. Penalization was more likely for hospitals with fewer THA and TKA discharges (Rp = -0.142; P < .001), medium-sized institutions (100 to 499 beds; V = 0.075; P = .002), teaching hospitals (V = 0.049; P = .019), and safety net hospitals (V = 0.043; P = .039). Penalization was less likely for West and Midwest hospitals (V = 0.112; P < .001). CONCLUSIONS: A higher Overall Hospital Quality Star Rating and recognition among the US News & World Report's top 50 orthopaedic hospitals were associated with a reduced likelihood of THA and TKA readmission penalties. The other 4 widely accepted quality rating systems did not correlate with readmission penalties. Teaching and safety net hospitals may be biased toward higher readmission rates.

Suppressive Antibiotic Therapy After Debridement, Antibiotics, and Implant Retention is Well-Tolerated Without Inducing Resistance: A Multicenter Study.

BACKGROUND: Suppressive antibiotic therapy (SAT) after total joint arthroplasty (TJA) debridement, antibiotics, and implant retention (DAIR) maximizes reoperation-free survival. We evaluated SAT after DAIR of acutely infected primary TJA regarding: 1) adverse drug reaction (ADR)/intolerance; 2) reoperation for infection; and 3) antibiotic resistance. METHODS: Patients who underwent total knee arthroplasty (TKA) or total hip arthroplasty (THA) DAIR for acute periprosthetic joint infection at two academic medical centers from 2015 to 2020 were identified (n = 115). Data were collected on patient demographics, infecting organisms, antibiotics, ADR/intolerances, reoperations, and antibiotic resistances. Median SAT duration was 11 months. Stepwise multivariate logistic regressions were used to identify covariates significantly associated with outcomes of interest. RESULTS: There were 11.1 and 16.3% of TKA and THA DAIR patients, respectively, who had ADR/intolerance to SAT. Patients prescribed trimethoprim/sulfamethoxazole (P = .0014) or combination antibiotic therapy (P = .0169) after TKA DAIR had increased risk of ADR/intolerance. There was no difference in reoperation-free survival between TKA (83.3%) and THA (65.1%) DAIR (P = .5900) at mean 2.8-year follow-up. Risk of reoperation for infection was higher among TKA Staphylococcus aureus infections (P = .0004) and lower with increased SAT duration (P < .0450). The optimal duration of SAT was nearly 2 years. No cases of antibiotic resistance developed due to SAT. CONCLUSIONS: Consider SAT after TJA DAIR due to improved reoperation-free survival and favorable safety profile. Prolonged SAT did not induce antibiotic resistance. Use trimethoprim/sulfamethoxazole with caution because of the increased likelihood of ADR/intolerance. LEVEL OF EVIDENCE: Therapeutic Level III.

Postoperative Opioid Consumption is Greater after Simultaneous versus Staged Bilateral Total Knee Arthroplasty.

Increased exposure to opioids around total knee arthroplasty (TKA) can lead to a risk of long-term dependence. We hypothesized that performing simultaneous bilateral total knee arthroplasty (simBTKA) over staged surgery (staged bilateral total knee arthroplasty [stgBTKA]) may decrease the total amount of opiates used. We retrospectively reviewed 29 patients who underwent simBTKAs performed between February 2015 and November 2020 and identified 23 that did not use opioids ≤90 days prior to surgery. These were frequency matched for gender and body mass index to 50 stgBTKAs completed within 6 months who also were opioid-free ≤90 days prior to their first surgery. Using our state's prescription database, we reviewed postsurgery opioid refills and morphine milligram equivalents (MMEs) for the two groups and compared their initial MME prescription at discharge and their total MME consumption 6 months postoperatively. Total MME consumption for the stgBTKA group included all prescriptions following the first and 6 months after the second surgery, whereas for the simBTKA group, total consumption included the 6 months after their two same-day surgeries. The simBTKA group had more MMEs prescribed initially (median = 375) than did the stgBTKA group after second surgery (median = 300; p < 0.007), larger postoperative-refill MMEs in the first 30 days (median = 300) than stgBTKA (median = 0; p = 0.221) and increased total MME consumption 6 months after surgery (median = 675) compared with stgBTKA after second surgery (median = 450; p = 0.077). However, both groups had similar monthly consumptions rates, with medians I MMEs/month of 112 for simBTKA versus 96 for stgBTKA (p = 0.585). Our results suggest there is no significant difference in opioid consumption between simBTKA and stgBTKA. In fact, we found that simBTKA patients received larger opioid amounts in the immediate postoperative period as well as slightly larger amounts at 30 days.

Robotic-assisted TKA is Not Associated With Decreased Odds of Early Revision: An Analysis of the American Joint Replacement Registry.

BACKGROUND: Robotic-assisted TKA continues to see wider clinical use, despite limited knowledge of its impact on patient satisfaction and implant survival. Most studies to date have presented small cohorts and came from single-surgeon or single-center experiences. Therefore, a population-level comparison of revision rates between robotic-assisted and conventional TKA in the registry setting may help arthroplasty surgeons better define whether robotic assistance provides a meaningful advantage compared with the conventional technique. QUESTIONS/PURPOSES: (1) After controlling for confounding variables, such as surgeon, location of surgery, and patient comorbidity profile, were robotic-assisted TKAs less likely than conventional TKAs to result in revision for any reason at 2 years? (2) After again controlling for confounding variables, were robotic-assisted TKAs less likely to result in any specific reasons for revision than the conventional technique at 2 years? METHODS: The American Joint Replacement Registry was used to identify patients 65 years or older who underwent TKA between January 2017 and March 2020 with a minimum of 2 years of follow-up. Patients were limited to age 65 yeas or older to link TKAs to Medicare claims data. Two retrospective cohorts were created: robotic-assisted TKA and conventional TKA. Patient demographic variables included in the analysis were age, gender, BMI, and race. Additional characteristics included the Charlson comorbidity index, anesthesia type, year of the index procedure, and length of stay. A total of 10% (14,216 of 142,550) of TKAs performed during this study period used robotics. Patients with robotic-assisted TKA and those with conventional TKA were similar regarding age (73 ± 6 years versus 73 ± 6 years; p = 0.31) and gender (62% [8736 of 14,126] versus 62% [79,399 of 128,334] women; p = 0.34). A multivariable, mixed-effects logistic regression model was created to analyze the odds of all-cause revision as a factor of robot use, and a logistic regression model was created to investigate specific revision diagnoses. RESULTS: After controlling for potentially confounding variables, such as surgeon, location of surgery, and Charlson comorbidity index, we found no difference between the robotic-assisted and conventional TKAs in terms of the odds of revision at 2 years (OR of robotic-assisted versus conventional TKA 1.0 [95% CI 0.8 to 1.3]; p = 0.92). The reasons for revision of robotic-assisted TKA did not differ from those of conventional TKA, except for an increased odds of instability (OR 1.6 [95% CI 1.0 to 2.4]; p = 0.04) and pain (OR 2.1 [95% CI 1.4 to 3.0]; p < 0.001) in the robotic-assisted cohort. CONCLUSION: In light of these findings, surgeons should not assume that robotic assistance in TKA will lead to improved early implant survival. Our findings do not support an improvement over conventional TKA with robotic assistance with regards to common causes of early revisions such malalignment, malposition, stiffness, pain, and instability, and in some cases, suggest there is a benefit to conventional TKA. Differences in the mid-term and long-term revision risk with conventional versus robotic-assisted TKA remain unknown. Appropriate informed consent around the use of robotic assistance should not imply decreased early revision risk. LEVEL OF EVIDENCE: Level III, therapeutic study.

Systemic Inflammatory Response Syndrome and Prosthetic Joint Infection.

BACKGROUND: The development of systemic inflammatory response syndrome (SIRS) criteria leads to increased mortality. Little is known about development of SIRS in patients who have prosthetic joint infection (PJI). We aimed to determine the incidence, risk factors, clinical outcomes, and causative organisms in patients who develop SIRS with PJI. METHODS: We retrospectively identified 655 patients (321 men, 334 women; 382 total hip, 273 total knee) who have hip or knee PJI at 1 institution between July 1, 2015 and December 31, 2020. We formed 2 groups: patients who have SIRS alert (PJI + SIRS) and patients who do not have SIRS alert (PJI). We analyzed clinical outcomes, comorbidities, and operating room culture results. RESULTS: Of 655 patients, 63 developed SIRS with PJI (9.6%). Intensive care unit (ICU) admission rates (27.0 versus. 6.9%, P < .001) and length of stay (7.7 versus. 5.6 days, P = .003) were greater in PJI + SIRS. At 2 years, reoperation (36.5 versus. 22.3%, P = .01) and mortality rates (17.5 versus. 8.8%, P = .03) were greater in PJI + SIRS. Risk factors included deficiency anemia (P = .001), blood loss anemia (P = .013), uncomplicated diabetes (P = .006), diabetes with complication (P = .001), electrolyte disorder (P < .00001), neurological disorder (P = .0001), paralysis (P = .026), renal failure (P = .005), and peptic ulcer disease (P = .004). Staphylococcus aureus more commonly speciated on tissue cultures in PJI + SIRS (P = .002). CONCLUSION: The incidence of SIRS is 10% among patients who have PJI. Development of PJI + SIRS is associated with increased lengths of stay, ICU admissions, and 2-year reoperation and mortality rates. Identifying certain comorbidities can stratify patients' risk of developing PJI + SIRS.

Articulating Hip Spacers with a Constrained Acetabular Liner: Effect of Acetabular Bone Loss and Cementation Quality.

Articulating hip spacers for periprosthetic joint infection (PJI) offer numerous advantages over static spacers such as improved patient mobilization, hip functionality, and soft tissue tension. Our study aimed to determine complication rates of a functional articulating spacer using a constrained liner to determine the role of acetabular cementation mantle and bone loss on the need for second-stage surgery. A retrospective review of 103 patients was performed and demographic information, spacer components and longevity, spacer-related complications, reinfection rates, and grade of bone loss and acetabular cement mantle quality were determined. There was no significant difference in spacer-related complications or reinfection rate between PJI and native hip infections. 33 of 103 patients (32.0%) elected to retain their spacers. Between patients who retained their initial spacer and those who underwent reimplantation surgery, there was not a significant difference in cement mantle grade (p = 0.52) or degree of bone loss (p = 0.78). Functional articulating antibiotic spacers with cemented constrained acetabular liners demonstrate promising early results in the treatment of periprosthetic and native hip infections. The rate of dislocation events was low. Further efforts to improve cement fixation may help decrease the need for second-stage reimplantation surgery.

Reduced osteoprotegerin expression by osteocytes may contribute to rebound resorption after denosumab discontinuation.

Denosumab is an anti-RANKL Ab that potently suppresses bone resorption, increases bone mass, and reduces fracture risk. Discontinuation of denosumab causes rapid rebound bone resorption and bone loss, but the molecular mechanisms are unclear. We generated humanized RANKL mice and treated them with denosumab to examine the cellular and molecular conditions associated with rebound resorption. Denosumab potently suppressed both osteoclast and osteoblast numbers in cancellous bone in humanized RANKL mice. The decrease in osteoclast number was not associated with changes in osteoclast progenitors in bone marrow. Long-term, but not short-term, denosumab administration reduced osteoprotegerin (OPG) mRNA in bone. Localization of OPG expression revealed that OPG mRNA is produced by a subpopulation of osteocytes. Long-term denosumab administration reduced osteocyte OPG mRNA, suggesting that OPG expression declines as osteocytes age. Consistent with this, osteocyte expression of OPG was more prevalent near the surface of cortical bone in humans and mice. These results suggest that new osteocytes are an important source of OPG in remodeling bone and that suppression of remodeling reduces OPG abundance by reducing new osteocyte formation. The lack of new osteocytes and the OPG they produce may contribute to rebound resorption after denosumab discontinuation.

Leg Length Discrepancy After Hip Fracture Repair is Associated With Reduced Gait Speed.

Introduction: A negative correlation exists between functional outcomes and leg length discrepancy (LLD) following hip fracture repair. We have assessed the effects of LLD following hip fracture repair in elderly patients on 3-meter walking time, standing time, activities of daily living (ADL), and instrumental activities of daily living (IADL). Methods: One hundred sixty-nine patients enrolled in the STRIDE trial were identified with femoral neck, intertrochanteric, and subtrochanteric fractures that were treated with partial hip replacement, total hip replacement, cannulated screws, or intramedullary nail. Baseline patient characteristics recorded included age, sex, body mass index Charlson comorbidity index (CCI) score. ADL, IADL, grip strength, sit-to-stand time, 3-meter walking time and return to ambulation status were measured at 1 year after surgery. LLD was measured on final follow-up radiographs by either the sliding screw telescoping distance or the difference from a trans-ischial line to the lesser trochanters, and was analyzed as a continuous variable using regression analysis. Results: Eighty eight patients (52%) had LLD <5 mm, 55 (33%) between 5-10 mm and 26 subjects (15%) >10 mm. Age, sex, BMI, Charlson score, and ambulation status had no significant impact on LLD occurrence. Type of procedure and fracture type did not correlate with severity of LLD. Having a larger LLD was not found to have a significant impact on post-operative ADL (P = .60), IADL (P = .08), sit-to-stand time (P = .90), grip strength (P = .14) and return to former ambulation status (P = .60), but did have a statistically significant impact on 3-meter walking time (P = .006). Discussion: LLD after hip fracture was associated with reduced gait speed but did not affect many parameters associated with recovery. Continued efforts to restore leg length after hip fracture repair are likely to be beneficial.

Socioeconomic Challenges in the Rural Patient Population in Need of Total Joint Arthroplasty.

Many challenges exist for the rural patient in need of joint arthroplasty. Optimization for surgery is more difficult due to factors such as deprivation, education, employment, household income, and access to proper surgical institutions. Rural individuals have less access to primary care and even less access to surgical specialists, creating a distinct subset of patients who endure higher costs, poorer outcomes, and lack of care. Reducing socioeconomic disparities in rural communities will require policy initiatives addressing the components of socioeconomic status (income, education, and occupation). Hopefully remote patient technologies can help with access and timely addressing of modifiable risk factors.

Highlights of the 2022 American Joint Replacement Registry Annual Report.

The 2022 American Joint Replacement Registry Annual Report includes data from over 2.8 million hip and knee procedures from over 1,250 institutions that encompass all 50 states and the District of Columbia. This represents a cumulative registered procedural volume growth of 14% compared to the previous year, making the American Joint Replacement Registry the largest arthroplasty registry by volume in the world.