Cemented vs Cementless Robotic-Assisted Total Knee Arthroplasty Yield Similar Short-Term Clinical Outcomes.

Background: In primary total knee arthroplasty (TKA), there is ongoing controversy about optimal fixation (cemented vs cementless). Cemented TKA remains the gold standard, with the largest body of long-term evidence available to support it. However, cementless TKA implants are gaining popularity due to potential biomechanical advantages and a growing body of literature supporting survivorship. Due to paucity of literature investigating fixation methods in robotic-assisted TKA (Ra-TKA), we aim to compare clinical outcomes of cementless Ra-TKA with those of cemented Ra-TKA. Methods: This is a retrospective cohort study of patients who underwent Ra-TKA by 19 surgeons comparing results of cases using cementless vs cemented fixation. We observed short-term complications, emergency room visits, and readmissions. We collected patient-reported outcomes measurement information system and knee injury and osteoarthritis outcome scores preoperatively and 12 weeks after surgery. Results: A total of 582 TKA cases were included: 335 cementless and 247 cemented. The patients in the cementless group were younger and had a higher body mass index. The cemented group had a higher rate of return to the operating room, with manipulation under anesthesia for stiffness being the most common indication in both groups. There were no statistically significant differences in 30-day readmissions, 90-day emergency room visits, or patient-reported outcomes. Conclusions: Our retrospective study demonstrated higher return to operating room in the cemented group vs the cementless group. We reported no differences in any other short-term outcomes between the cementless and cemented Ra-TKA. Our data support efficacy and safety of cementless Ra-TKA at 3-month follow-up.

A COVID-19 Pivot Plan to Resume Elective Surgeries at the Hartford Healthcare Connecticut Orthopaedic Institute.

Background The Connecticut Orthopaedic Institute (COI) conceptualized a Pivot Plan during an elective surgery moratorium at the beginning of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic with the goal of planning and executing orthopedic procedures safely. With the resumption of elective surgeries and the continued planning of surgical recovery over the months (and possibly years) to follow, facilities must brace themselves for repeat waves of COVID-19. Thereby, herein we share the Pivot Plan, its implementation process, evaluation of patient safety, and program performance during a pandemic. This could inform the efforts of other institutions seeking to restart non-emergent surgeries during similarly trying times in the future.  Methods The COI formed a multidisciplinary team of leaders that met weekly to design a Pivot Plan and a dashboard to guide the resumption of surgeries and assess the performance of the Pivot Plan. The plan revolved around four domains: safety, space, staff, and supplies. It was implemented in two COI-affiliated facilities: MidState Medical Center (MMC) and St. Vincent's Medical Center (SVMC). Monthly metrics from May to November 2020 were compared to the six-month averages for the pre-pandemic baseline period from September 2019 to February 2020. Results The total number (N) of elective orthopaedic cases prior to the pandemic pre-COVID averaged 372 cases per month for MMC and 197 cases for SVMC. During the pandemic post-COVID, N averaging at 361 for MMC and 243 for SVMC illustrates COI was able to perform elective surgeries amid a worsening pandemic. Same-day (SD) discharge rates for total joint arthroplasty (TJA) pre-COVID averaged 8% for MMC and 3% for SVMC. Post-COVID, the SD average was 16.7% for MMC and 11.4% for SVMC. This data indicates that orthopaedic providers were cognizant of length of stay in order to reduce the risk of in-hospital exposure to COVID-19. The 30-day readmission (30R) rate for TJA pre-COVID averaged 1.4% for MMC and 2.7% for SVMC. A high level of care and follow-up is reflected in a lower average 30R post-COVID, 1.1% for both MMC and SVMC. Transitions for TJA patients to their home settings after surgery also reflect the quality of care and the efficiency of the patient throughput process with necessary precautions in place. Post-COVID, the patient transition to home (T) averaged 98.1% for MMC and 97.5% for SVMC compared to T = 96.8% for MMC and 88% for SVMC pre-COVID. No patients experienced deep vein thrombosis or pulmonary embolism during the time period of the project. Positive COVID-19 diagnosis 23 days after discharge was 0% at MMC and 0.2% at SVMC. Conclusion The COI Pivot Plan was successfully implemented at two different hospitals offering elective orthopaedic surgeries to a varied patient population. The precautions taken by COI were effective in controlling the spread of the SARS-CoV-2 virus while returning to elective orthopaedic surgery. Furthermore, data collected before and after the onset of the COVID-19 pandemic indicated that program performance and quality improved.

Local insulin therapy affects fracture healing in a rat model.

A significant number of lower extremity fractures result in mal-union necessitating effective treatments to restore ambulation. Prior research in diabetic animal fracture models demonstrated improved healing following local insulin application to the fracture site and indicated that local insulin therapy can aid bone regeneration, at least within an insulin-dependent diabetic animal model. This study tested whether local insulin therapy could accelerate femur fracture repair in normal, non-diabetic rats. High (20 units) and low (10 units) doses of insulin were delivered in a calcium sulfate carrier which provided sustained release of the exogenous insulin for 7 days after fracture. Histomorphometry, radiographic scoring, and torsional mechanical testing were used to measure fracture healing. The fracture calluses from rats treated with high-dose insulin had significantly more cartilage than untreated rats after 7 and 14 days of healing. After 4 weeks of healing, femurs from rats treated with low-dose insulin had significantly higher radiographic scores and mechanical strength (p < 0.05), compared to the no treatment control groups. The results of this study suggest that locally delivered insulin is a potential therapeutic agent for treating bone fractures. Further studies are necessary, such as large animal proof of concepts, prior to the clinical use of insulin for bone fracture treatment.

Effects of local insulin delivery on subperiosteal angiogenesis and mineralized tissue formation during fracture healing.

Local insulin delivery has been shown to improve osseous healing in diabetic animals. The purpose of this study was to quantify the effects of local intramedullary delivery of saline or Ultralente insulin (UL) on various fracture healing parameters using an in vivo non-diabetic BB Wistar rat model. Quantitation of local insulin levels showed a rapid release of insulin from the fractured femora, demonstrating complete release at 2 days. RT-PCR analysis revealed that the expression of early osteogenic markers (Col1α2, osteopontin) was significantly enhanced with UL treatment when compared with saline controls (p < 0.05). Significant differences in VEGF + cells and vascularity were evident between the treatment and control groups at day 7 (p < 0.05). At day 21, histomorphometric analysis demonstrated a significant increase in percent mineralized tissue in the UL-treated animals compared with controls (p < 0.05), particularly within the subperiosteal region of the fracture callus. Mechanical testing at 4 weeks showed significantly greater mechanical strength for UL-treated animals (p < 0.05), but healing in control animals caught up at 6 weeks post-fracture. These results suggest that the primary osteogenic effect of UL during the early stages of fracture healing (1-3 weeks) is through an increase in osteogenic gene expression, subperiosteal angiogenesis, and mineralized tissue formation.

Role of local insulin augmentation upon allograft incorporation in a rat femoral defect model.

Each year, over one million orthopedic operations are performed which a bony defect is presence, requiring the use of further augmentation in addition to bony fixation. Application of autogenous bone graft is the standard of care to promote healing of these defects, but several determents exist in using autogenous bone graft exist including limited supply and donor site morbidity. Prior work has demonstrated that local insulin application to fracture sites promote fracture healing, but no work has been performed to date in its effects upon defect healing/allograft incorporation. The goal of this study was to examine the potential role of local insulin application upon allograft incorporation. Microradiographic, histologic, and histomorphometric analysis outcome parameters showed that local insulin significantly accelerated new bone formation. Histological comparisons using predetermined scoring systems demonstrated significantly greater healing in femora treated with insulin compared to control femora (p < 0.001). Quantitatively more bone production was also observed, specifically in areas of endosteal (p = 0.010) and defect (p = 0.041) bone in femora treated with local insulin, compared to control femora, 6 weeks after implantation. This study demonstrates the potential of local insulin as an adjunct for the treatment of segmental defect and allograft incorporation.

Response of bone subjected to optimized high dose irradiation.

Allograft tissues are used in over one million musculoskeletal procedures per year. Consequently, it is crucial tissue banks use procedures to militate against allograft associated bacterial and viral infections. Recent studies have identified an important pathogen inactivation technology for musculoskeletal allografts that utilizes high-dose gamma irradiation (50 kGy) under controlled conditions. A total dose of 50 kGy assures that the current standard for medical devices for a microbial sterility assurance level of 10(- 6) is met. Furthermore, the pathogen inactivation technology results in a greater than four log inactivation of enveloped and nonenveloped viruses. Efficacious clinical outcome from musculoskeletal allografts exposed to this innovative sterilization procedure will require that there is no performance decrement in the allograft's biological properties. Therefore, to validate this objective, we executed a study focusing on remodeling and osteoconduction of bone allografts treated with a high dose of gamma irradiation (50 kGy), radioprotectants and well-defined operating parameters of temperature and water content. A rabbit calvarial model was used to test the hypothesis that remodeling and osteoconduction of allogeneic bone treated with the new pathogen inactivation technology would be equivalent to nontreated allogeneic bone. Results indicated treated bone allografts were comparable to nontreated allografts. We conclude, therefore, that based on this outcome and other reports, that high doses of gamma irradiation under optimized conditions designed to reduce free radical damage to tissue will provide safer allografts.

Cellular uptake of functional nanogels prepared by inverse miniemulsion ATRP with encapsulated proteins, carbohydrates, and gold nanoparticles.

Atom transfer radical polymerization (ATRP) was used to produce a versatile drug delivery system capable of encapsulating a range of molecules. Inverse miniemulsion ATRP permitted the synthesis of biocompatible and uniformly cross-linked poly(ethylene oxide)-based nanogels entrapping gold nanoparticles, bovine serum albumin, rhodamine B isothiocyanate-dextran, or fluoresceine isothiocyanate-dextran. These moieties were entrapped to validate several biological outcomes and to model delivery of range of molecules. Cellular uptake of nanogels was verified by transmission electron microscopy, gel electrophoresis, Western blotting, confocal microscopy, and flow cytometry. Fluorescent colocalization of nanogels with a fluorophore-conjugated antibody for clathrin indicated clathrin-mediated endocytosis. Furthermore, internalization of nanogels either with or without GRGDS cell attachment-mediating peptides was quantified using flow cytometry. After 45 min of incubation, the uptake of unmodified FITC-Dx-loaded nanogels was 62%, whereas cellular uptake increased to >95% with the same concentration of GRGDS-modified FITC-Dx nanogels. In addition, a spheroidal coculture of human umbilical vascular endothelial cells (HUVECs) and human mesenchymal stem cells (hMSCs) validated cell endocytosis. Application of ATRP enabled the synthesis of a functionalized drug delivery system with a uniform network that is capable of encapsulating and delivering inorganic, organic, and biological molecules.