Three-dimensional-based native alignment phenotype classification system: Description for use in planning for deformities during total knee arthroplasty.

Introduction: Total knee arthroplasty (TKA) is a complex surgical procedure that traditionally relies on two-dimensional radiographs for pre-operative planning. These radiographs may not capture the intricate details of individual knee anatomy, potentially limiting the precision of surgical interventions. With advancements in imaging technology, there is an opportunity to refine TKA outcomes. This study introduces the Native Alignment Phenotype classification system that is based on pre-operative 3-dimensional computed tomography (CT) scans, aiming to provide a more detailed understanding of knee deformities and their influence on characterizing knee osteoarthritis and planning for TKA procedures. Methods: There were 1406 pre-operative non-weight-bearing CT scans analyzed by a single surgeon experienced with robotically-assisted total knee arthroplasties. These scans were converted into three-dimensional models, focusing on the coronal and sagittal planes. Intraoperatively, the robotic system was used to capture native coronal and sagittal deformities for each patient. These values were captured with the patient's leg held in a non-stress, extension pose. A new classification system, 'The Native Alignment Phenotype', was developed to categorize the specific differences between individual knees. Results: There were four primary knee malalignments identified: varus deformity; valgus deformity; and two deformities in the sagittal plane. These malalignments were further categorized based on the degrees of deviation, creating groups with 5° coronal and sagittal ranges. A total of 77 phenotypic alignment patterns were found based on the analyzed cohort. In the coronal plane, varus HKA deformity between 6 and 10° was the most common, with 36.9% of the cases, followed by varus HKA alignment, which was between 0 and 5°, representing 34.3% of the cases. In the sagittal plane, neutral and flexion contracture deformities between 0 and 5° were the most common, with 32.6% of the cases, followed by a fixed flexion contracture alignment, which was between 6 and 10°, representing 28.7% of the cases. When combining coronal and sagittal planes, the most common alignment was the varus between 0 and 5° with a flexion contracture between 0 and 5° (12.5% of cases), closely followed by the varus between 6 and 10° with a flexion contracture between 6 and 10° (12.4% of cases). Conclusion: The Native Alignment Phenotype classification system offers a nuanced understanding of knee deformities based on three-dimensional (CT scan) assessments, potentially leading to improved surgical outcomes in TKA. By leveraging the detailed data from the CT scans, this system provides a more comprehensive view of the knee's anatomy, emphasizing the importance of individualized, data-driven approaches in knee surgery.

The Impact of Preoperative Weight Loss Timing on Surgical Outcomes in Total Hip Arthroplasty.

BACKGROUND: Elevated body mass index (BMI) increases surgical complications post-total hip arthroplasty (THA). However, the effects of rapid weight loss pre-THA remain unclear. This study evaluated patients who had initial BMIs between 40 and 50, and then achieved a BMI under 35 at various intervals before their THA. Comparisons were made with consistent obese and nonobese groups to understand potential complications. METHODS: Using a national database, we categorized THA patients based on initial BMI and weight loss timing before the surgery. These were contrasted with those maintaining a steady BMI of 20 to 30 or 40 to 50. We monitored outcomes like periprosthetic joint infections (PJI), surgical site infections (SSI), and noninfectious revisions for 2 years postsurgery, incorporating demographic considerations. Statistical analyses utilized Chi-square tests for categorical outcomes and Student's t-tests for continuous variables. RESULTS: Among patients who had a BMI of 45 to 50, weight loss 3 to 9 months presurgery increased PJI risks at 90 days (Odds Ratios [OR]: 2.15 to 5.22, P < .001). However, weight loss a year before the surgery lowered the PJI risk (OR: 0.14 to 0.27, P < .005). Constantly obese patients faced heightened PJI risks 1 to 2 years postsurgery (OR: 1.64 to 1.95, P < .015). Regarding SSI, risks increased with weight loss 3 to 9 months before surgery, but decreased when weight loss occurred a year earlier. In the BMI 40 to 45 group, weight loss 3 to 6 months presurgery showed higher PJI and SSI at 90 days (P < .001), with obese participants consistently at greater risk. CONCLUSIONS: While high BMI poses THA risks, weight loss timing plays a crucial role in postoperative complications. Weight loss closer to the surgery (0 to 9 months) can heighten risks, but shedding weight a year in advance seems beneficial. Conversely, initiating weight loss approximately a year before surgery offers potential protective effects against postoperative issues. This highlights the importance of strategic weight management guidance for patients considering THA, ensuring optimal surgical results and reducing potential adverse outcomes.

The use of preoperative continuous positive airway pressure in patients with obstructive sleep apnea following total hip arthroplasty: A propensity score matched analysis.

Introduction: Obstructive sleep apnea (OSA) impacts approximately 936 million individuals globally and is known to complicate post-surgical recovery, particularly after total hip arthroplasty (THA). While continuous positive airway pressure (CPAP) is commonly recommended for managing OSA, its effect on THA recovery remains uncertain. The study aimed to assess the impact of CPAP use on post-THA outcomes in patients with OSA, focusing on medical complications and periprosthetic joint infection (PJI) at 90 days and 1 year. Methods: A national, all-payer database was utilized to identify patients undergoing primary THA between 2010 and 2021. Patients with OSA were stratified based on CPAP use through propensity score matching. Three matched groups were formed: OSA without CPAP, OSA with CPAP, and no OSA. Medical and surgical complications were assessed at 90 days and 1 year post-THA. Results: Patients with OSA using CPAP exhibited more baseline comorbidities than those without CPAP. CPAP use was associated with inferior outcomes, including higher odds of PJI, wound complications, and venous thromboembolism at 90 days and 1 year post-THA. These trends were consistent even after adjusting for confounders. Conclusion: CPAP use, indicative of severe OSA, was linked to worse post-THA outcomes, emphasizing the importance of recognizing OSA severity preoperatively. The study does not advocate for or against CPAP use but underscores the heightened risk in this patient population, guiding clinicians in tailoring perioperative strategies and counseling patients about potential risks.

Timing Matters: Optimizing the Timeframe for Preoperative Weight Loss to Mitigate Postoperative Infection Risks in Total Knee Arthroplasty.

BACKGROUND: We explore the incidence of periprosthetic infections post-total knee arthroplasty (TKA) in morbidly obese patients who achieved weight loss. Current American Academy of Orthopaedic Surgeons guidelines suggest a preoperative body mass index (BMI) below 40 for TKA. This study assesses infection risks in patients initially who had a BMI of 40-50 who reduced their BMI to under 35 at varying intervals prior to surgery. METHODS: We reviewed a national, all-payer database, PearlDiver, for patients undergoing primary TKA. Patients were stratified based on initial BMI of 40 to 50 and reduction of BMI to less than 35 at 3 months (n = 1,932), 3 to 6 months (n = 794), 6 to 9 months (n = 2,233), and 9 to 12 months (n = 1,194) prior to TKA, as well as patients who had a BMI between 40 to 50 (n = 41,632) on the day of surgery. The nonobese group comprised of patients who had a BMI between 20 and 30 (n = 33,294). Multivariate analyses were performed at one-year follow-up. RESULTS: We found an increased risk of PJI for patients who had achieved BMI reduction less than nine months prior to TKA, compared to the BMI 20 to 30 cohort at the one-year follow-up (P < .001). Patients who achieved BMI reduction nine to twelve months prior to TKA showed no significant difference in PJI risk compared to the matching nonobese cohort at one-year follow-up (P = .400). CONCLUSIONS: In conclusion, our results suggest that weight loss should be achieved at least nine months before TKA to decrease infection risks. These findings have significant implications for surgical considerations in obese patients undergoing TKA.

Mako® Robotic-Arm Assisted Total Hip Arthroplasty: Avoiding Impingement with Updated THA Software.

The use of robotic-assisted total hip arthroplasty and three-dimensional computed tomography scan-based templating has become increasingly popular over the last 10 years. However, proper planning and execution are vital to producing optimal patient outcomes. In order to achieve these outcomes, the robotic-assisted system requires training, familiarity, and experience. The goal of this article is to provide clear and condensed examples of preoperative planning, as well as adjustments that one can make to avoid impingement. The surgical technique for robotic-assisted total hip arthroplasty is also briefly discussed. Examples will be given using the latest computed tomography (CT) scan-based robotic platform for osteoarthritic hips, with specific examples of various cases of impingement that might be encountered by the surgeon and how to ultimately avoid this problem when performing the arthroplasty. This article, through case histories, will discuss the various principles and adjustments that can be made to place components in the ideal location based on individual anatomy.

True Cost of Operating Room Time: Implications for an Orthopaedic Trauma Service.

OBJECTIVE: To derive an accurate estimate of the operating cost per minute for an orthopaedic trauma room. STUDY DESIGN: Retrospective economic analysis. SETTING: Level II Trauma Center. INTERVENTION: Hospital cost-accounting system query. MAIN OUTCOME MEASUREMENTS: Direct fixed costs, direct variable costs, and hospital overhead. RESULTS: Operating room per minute costs include direct variable costs of $2.77, direct fixed costs of $2.47, and hospital overhead costs of $10.97. Total per minute costs amounted to $16.21. This does not include professional fees of anesthesiology or surgeons or the costs of soft goods or implants. CONCLUSIONS: This is the first published study to document the true per minute cost of an orthopaedic trauma operating room. Such information is valuable when defining the value of a dedicated operating room, negotiating employment contracts, defining call stipends, and brokering capital purchases for the orthopaedic trauma service. LEVEL OF EVIDENCE: Economic Level IV. See Instructions for Authors for a complete description of levels of evidence.