Unique presentation of an intramuscular abscess caused by Bacteroides pyogenes in the setting of a cat bite: A case report.

Cat bites are a relatively common emergency department presentation. The most common species isolated from cat bite wounds is Pasteurella multocida. In this case report, we discuss a unique case of an intramuscular abscess caused by Bacteroides pyogenes. Antibiotic resistance in Bacteroides species is a growing concern and thus should be treated with caution. We present an 81-year-old female who presented to the emergency department with left calf pain that began 3 weeks prior to the emergency department presentation. She was initially seen by her primary care provider and was prescribed oral Trimethoprim/Sulfamethoxazole and Amoxicillin/Clavulanate. Despite oral antibiotics, she began to have worsening swelling, erythema, and fevers. In the emergency department, the patient's left calf was noticeably erythematous and tender to palpation. Lab work showed a C-reactive protein of 12.4 mg/dl, erythrocyte sedimentation rate of 38 mm/h, and white blood cell count of 15.1. Computed tomography imaging showed an irregularly shaped fluid collection at the junction of the calf musculature and upper aspect of the Achilles tendon. The decision was made to perform an operative incision and debridement on the evening of her presentation. On postoperative day 2, the wound cultures grew positive for both Pasturella multocida and Bacteroides pyogenes. She was subsequently discharged with oral Amoxicillin/Clavulanate 875 mg twice daily for 4 weeks. Further studies can be performed to identify the most efficient ways to isolate and treat this species. This case report emphasizes the importance of ordering both aerobic and anaerobic cultures and aiming antimicrobial therapy against both Pasteurella and anaerobic bacteria.

Correction of Severe Posterior Tibial Slope in Revision Total Knee Arthroplasty With Cementation and Cone Technology.

Failed primary total knee arthroplasties are becoming more common among a younger, more active patient demographic. Aseptic failures with proximal tibial bone loss, specifically severe posterior tibial collapse, are difficult problems not well described in the literature. There are limited options for reconstructing large defects of the proximal tibia that appropriately restore slope while providing adequate structural support. To our knowledge, this technique to address a large, uncontained posterior proximal tibial defect has not been described in the literature. The purpose of this case report was to detail the surgical technique of how the implementation of cone technology with cementation techniques produced excellent clinical results for a patient with this difficult problem.

Mako™ Robotic-Arm Assisted Medial Unicompartmental Knee Arthroplasty: Surgical Technique from the Office to the Operating Room.

The utilization of robotic-arm assisted unicompartmental knee arthroplasty (UKA) or partial knee arthroplasty (PKA) for the treatment of medial unicompartmental osteoarthritis has continued to increase. This is in part due to the consistently reproducible accuracy and precision of implant planning, intra-operative ligament balancing software, tracking optimization software, robotic-arm assisted bone preparation, excellent survivorship rates, and improvements in many patient-reported outcomes compared to manual UKA, using the Stryker Mako™ Robotic Partial Knee System (Stryker, Mako Surgical Corp., Mahwah, New Jersey). Training in the utilization of robotic-arm assistance can be time-consuming and comes with an associated learning curve even after the in-person training and coursework is complete, like most procedures. Therefore, our aim was to describe the pre-operative planning and intra-operative surgical technique for using a robotic-arm assisted partial knee system for UKA/PKA in patients who have unicompartmental medial knee osteoarthritis. Specifically, we will discuss: 1) pre-operative planning; 2) operative setup; 3) intra-operative steps; 4) execution of the plan; and 5) trialing, implantation, and final assessments.

Arthrofibrosis in Robotic Total Knee Arthroplasty: An Investigation Into How Robotic Assistance May Contribute to a Tight Knee.

INTRODUCTION: Arthrofibrosis after total knee arthroplasty (TKA) can lead to pain and restricted range of motion. Matching native knee kinematics is crucial in avoiding arthrofibrosis postoperatively. However, manual jig-based instruments have demonstrated variability and inaccuracy during primary TKA. Robotic-arm-assisted surgery was developed to increase the precision and accuracy of bone cuts and component alignment. In the literature, limited information on arthrofibrosis after robotic-assisted TKA (RATKA) exists. The purpose of this study was to compare the incidence of arthrofibrosis after manual TKA (mTKA) with RATKA by examining the need for manipulation under anesthesia (MUA) postoperatively and evaluating preoperative and postoperative radiographic parameters. METHODS: A retrospective analysis of patients who underwent primary TKA from 2019 to 2021 was conducted. Rates of MUA were evaluated and perioperative radiographs were analyzed to determine posterior condylar offset ratio, Insall-Salvati Index, and posterior tibial slope (PTS) in patients who underwent mTKA versus RATKA. Range of motion was recorded for patients who required MUA. RESULTS: A total of 1234 patients were included, of which 644 underwent mTKA, and 590 underwent RATKA. Thirty-seven RATKA patients compared with 12 mTKA patients required MUA postoperatively (P < 0.0001). A significant decrease in PTS postoperatively was seen in the RATKA (7.10° ± 2.4° preoperatively versus 2.46° ± 1.2° postoperatively), with a mean decrease of the tibial slope of -4.6° ± 2.5° (P < 0.0001). In patients requiring MUA, a larger decrease was seen in the RATKA group when compared with the mTKA group (mean -5.5 ± 2.0 versus -5.3 ± 0.78, P = 0.6585). No significant difference was seen in the posterior condylar offset ratio and Insall-Salvati Index in both groups. DISCUSSION: When conducting RATKA, it is important to match PTS close to the native tibial slope to decrease the incidence of arthrofibrosis postoperatively, as a decrease in PTS can lead to decreased postoperative knee flexion and poor functional outcomes.

Unicompartmental Knee Arthroplasty Has Lower Infection, Conversion, and Complication Rates Compared to High Tibial Osteotomy.

INTRODUCTION: Isolated medial knee osteoarthritis can be surgically treated with either unicompartmental knee arthroplasty (UKA) or high tibial osteotomy (HTO). Proponents of UKA suggest superior survivorship, while HTO offers theoretically improved alignment and joint preservation delaying total knee arthroplasty (TKA). Therefore, we compared complications in a large population of patients undergoing UKAs or HTOs. We specifically assessed 90 days, 1 year, and 2 years: (1) periprosthetic joint infection (PJI) rates, (2) conversion to TKA rates, as well as (3) complication rates. METHODS: A review of an administrative claims database was used to identify patients undergoing primary UKA (n = 13,674) or HTO (n = 1,096) from January 1, 2010 to December 31, 2019. Complication rates at 90 days, 1 year, and 2 years were compared between groups using unadjusted odds ratios (ORs) with 95% confidence intervals. Subsequently, multivariate logistic regressions were performed for PJI and conversion to TKA rates. RESULTS: At all time points, patients who underwent UKA were associated with lower rates of infection compared with those who underwent HTOs (all OR ≤ 0.51, all p ≤ 0.010). After 1 year, patients who received UKAs were found to have lower risk of requiring a conversion to a TKA versus those who received HTOs (all OR ≤ 0.55, all p < 0.001). Complications such as dislocations, periprosthetic fractures, and surgical site infections were found at lower odds in UKA compared with HTO patients. CONCLUSION: This study provides large-scale analyses demonstrating that UKA is associated with lower infection rates and fewer conversions to TKA compared with patients who have undergone HTO. Dislocations, periprosthetic fractures, and surgical site infections were also found to be lower among UKA patients. However, with careful patient selection, good results and preservation of the native knee are achieved with HTOs. Therefore, UKA versus HTO may be an important discussion to have with patients in an effort to lower the incidence of postoperative infections and complications.

Cefadroxil-Induced Clostridium difficile Infection Following Total Knee Arthroplasty.

Perioperative infection prophylaxis is a fundamental element of total knee arthroplasty (TKA). There has been a recent trend toward the use of extended postoperative oral antibiotics in high-risk patients. We describe a case report of a patient who underwent a primary TKA and subsequently developed Clostridium difficile colitis after an extended course of postoperative prophylactic oral cefadroxil. Following the C. difficile infection, the patient eventually developed bacteremia and a multidrug-resistant Escherichia coli prosthetic joint infection which required multiple debridements. Extended use of postoperative prophylactic oral cefadroxil may increase the risk of C. difficile-associated diarrhea. Additionally, our case suggests that C. difficile infection may subsequently increase the risk of bacteremia which could lead to prosthetic joint infection. More evidence is required to further define this risk.

Rare septic arthritis of the wrist and carpus primary osteoarticular manifestation of Mycobacterium tuberculosis: A case report.

Mycobacterium tuberculosis is one of the oldest and most studied infections, yet it remains one of the most common causes of infection-related death worldwide. The majority concern pulmonary tuberculosis. Therefore, extrapulmonary cases are rare and are often neglected in the differential diagnosis, especially in chronic musculoskeletal complaints. Nevertheless, osteoarticular manifestation of tuberculosis can cause disabling destruction of bone, cartilage, and surrounding soft tissues which may be exacerbated by a delay in diagnosis. This case report documents a case of primary osteoarticular tuberculosis causing septic arthritis of the wrist and carpus. In our case, the patient had no pulmonary burden of tuberculosis, which further delayed diagnosis and lead to irreversible damage to the wrist as well as carpus. This case illustrates the need to consider this diagnosis in at risk populations in order to prevent a delay in diagnosis and treatment.

Improving Postoperative Acute Kidney Injury Rates Following Primary Total Joint Arthroplasty.

BACKGROUND: Perioperative hip and knee arthroplasty complications remain a significant clinical and financial burden. Our institution has shifted to developing protocols to decrease these perioperative complications. This study focuses on acute kidney injury (AKI) rate status post primary total joint arthroplasty (TJA). Current literature demonstrates a 2%-15% incidence of AKI following TJA. However, there is a paucity of published literature on protocols that have effectively reduced AKI rates following TJA. The purpose of this study is to evaluate the effect that our institutionally developed perioperative renal protocol had on the postoperative AKI rates. METHODS: A retrospective cohort study was performed. Patient demographics, baseline creatinine, and postoperative creatinine values during the patient's hospitalization were collected and analyzed. The preintervention cohort data contained all patients at our institution who underwent a primary TJA from November 1, 2016 to January 1, 2018. The postintervention cohort included all primary TJA patients from July 1, 2018 to February 2, 2020. AKI was defined using the AKI Network classification system comparing baseline and postoperative creatinine values. A multivariate analysis was performed to determine the statistical significance of our results. RESULTS: Before intervention 1013 patients underwent a primary TJA with 68 patients developing an AKI postoperatively. After intervention 2169 patients underwent primary TJA with 90 patients developing an AKI (6.71% vs 4.15%; P = .0015, odds ratio = 0.59, 95% confidence interval = 0.42-0.82). CONCLUSION: This study demonstrated that implementation of a perioperative renal protocol can significantly reduce AKI rates. A reduction in AKI rates following TJA will result in improved outcomes and secondarily decrease the financial impact of postoperative complications seen following TJA.

Intraoperative Hardware Failure of the Fassier-Duval Rescue System in a Pediatric Patient with Osteogenesis Imperfecta.

The use of telescopic intramedullary rods for the treatment of lower extremity deformity in children with osteogenesis imperfecta has been well described. The reinforcement of these weakened weightbearing bones with intramedullary devices leads to improvements in mobility that progress into adulthood. Although the current telescopic intramedullary rod systems are an upgrade from earlier systems, they are still associated with high rates of reoperation and complication. We describe a unique complication encountered during a revision which involved the male retriever system for the Fassier-Duval rod (FDR) (Pega Medical, Quebec, CA) experienced intraoperatively. To our knowledge, this mechanism of failure has not been previously described in the literature.

Thirty-Day Unplanned Readmission after Total Knee Arthroplasty at a Teaching Community Hospital: Rates, Reasons, and Risk Factors.

Unplanned readmission after total knee arthroplasty (TKA) has an increasing prevalence in the United States. Readmissions are now a metric for hospital quality of care, yet there are mixed results and variables associated with unplanned readmission. In this changing healthcare, it is critical for community healthcare institutions to identify risk factors for unplanned readmissions following TKA. Retrospective chart review and a hospital administrative database query to report causes, demographics, and medical comorbid risk factors result in 30-day readmission after undergoing primary TKA between 2011 and 2016 at a teaching community hospital. This study identified 7,482 primary TKA procedures of which 210 (2.8%) were unplanned readmissions. Gastrointestinal bleed (9.05%) and periprosthetic infection (8.10%) were the most common causes of readmission. Age 65 and older (odds ratio [OR], 1.64; 95% confidence interval [CI], 1.21-2.21; p = 0.0012), male (OR, 1.37; 95% CI, 1.03-1.83; p = 0.0302), length of stay > 3 days (OR, 2.04; 95% CI, 1.45-2.86; p < 0.0001), and discharge to rehab (OR, 2.21; 95% CI, 1.49-3.26; p ≤ 0.0001) were correlated significantly with risk of 30-day readmission. Chronic airway disease (OR, 2.81; 95% CI, 1.54-5.14; p = 0.0008) and obesity (OR, 1.45; 95% CI, 1.006-2.10; p = 0.0463) were significant risk factors. Higher Charlson comorbidity index was not a predictor of time to readmission within 30 days after TKA.