Anatomic Referencing of the Distal Femur in Total Knee Arthroplasty: The Impact of Orientation on Femoral Component Size.

BACKGROUND: Anatomic referencing in total knee arthroplasty places the femoral component flush to the anterior cortex while maintaining posterior condylar offset (PCO). The intent of this study was to evaluate how component position influences the femoral component size. METHODS: Digital surface models were created using 446 femora from an established computed tomography database. Virtual bone resections, component sizing, and component placement were performed assuming neutral (0°) flexion and neutral (3°) rotation relative to the posterior condyles. The appropriately sized femoral component, which had 2 mm of incremental size, was placed flush with the anterior cortex for optimal restoration of the PCO. Sizing and placement were repeated using 3 and 6° flexion and 0, 5, and 7° external rotation (ER). RESULTS: At 0° flexion, decreasing ER from 3 to 0° resulted in an average decreased anterior-posterior height (APH) of 1.9 mm, corresponding to a component size decrease of 1 for 88% of patients. At 7° ER, component size increased by an average of 2.5 mm, corresponding to a size increase for 80% of patients. Flexing the femoral component to 3° with ER at 3° resulted in a decrease in APH of 2.2 mm (1 size decrease in 93% of patients). At 3° flexion and 3° ER, 86% had the same component size as at 0° flexion and 0° ER. Increasing ER at 3° flexion increased APH by 1.2 mm at 5° and 3.1 mm at 7° on average, relative to 3° ER. Increasing flexion from 3 to 6° extended this effect. CONCLUSIONS: Flexion decreases the APH when the ER is held constant. The ER of the femoral component increases the APH across all tested flexion angles, causing an increase in the ideal femoral component size to maintain PCO. With anatomic referencing, alterations in femoral component positioning and subsequent changes in component size can be accounted for.

A Systematic Approach to Revision Total Knee Arthroplasty.

With the recent increase in primary total knee arthroplasties and the associated rise in failures of the index operation, there has been growing demand for orthopaedic surgeons to perform revision procedures. The orthopaedic surgeon performing revision total knee arthroplasty should be knowledgeable about the various etiologies of primary total knee arthroplasty failure, the steps for proper patient evaluation, and important factors in the preoperative planning process. A systematic methodology for obtaining surgical exposure, strategies for reconstruction, fundamentals of soft-tissue closure, and postoperative care also should be reviewed.

Are 20% of Patients Actually Dissatisfied Following Total Knee Arthroplasty? A Systematic Review of the Literature.

BACKGROUND: Total knee arthroplasty (TKA) is among the most performed orthopaedic surgeries in the United States with at least 1,000,000 cases performed per year. Dissatisfaction following TKA has often been reported as 20% or more, with a multitude of causes including sociodemographic, preoperative, and postoperative factors. The purpose of this study was to re-examine the rate and causes of dissatisfaction following TKA. METHODS: A systematic review of the literature was performed searching databases from 2010 to 2022. Only primary TKA cases were included and all cases of unicompartmental arthroplasty and revisions were excluded. After abstracts were reviewed, 35 articles were selected for a full-length review, which was ultimately reduced to 21 articles for final inclusion. RESULTS: The average rate of patient dissatisfaction was 10%. Excluding complications, the average rate of dissatisfaction was 7.3%. The most common sociodemographic factors for dissatisfaction were age < 65 years, lower income, and non-White patients. Preoperative factors included lower Kellgren-Lawrence scores, depression/anxiety, and pain catastrophizing. Postoperatively, most dissatisfaction was due to complications, unmet expectations, persistent pain, and stiffness. CONCLUSION: Based on our review, the average rate of patient dissatisfaction following TKA is 10%. Improved counseling for known risk factors may have reduced dissatisfaction rates by increasing preoperative patient optimization. Many studies in recent years have demonstrated the issue of poor patient coping skills, such as pain catastrophizing and anxiety/depression as a common cause of dissatisfaction. Ultimately, dissatisfaction following TKA still continues to affect a high portion of patients but less than historical reports of 20%.

Classifying Bone Loss in Failed Stemmed Total Knee Arthroplasty: Determining Reliability.

BACKGROUND: Failed stemmed total knee arthroplasty (TKA) components present with varying degrees of bone loss and technical challenges. A classification system has been proposed based upon metaphyseal bone loss and diaphyseal cortical integrity. A validation study was performed to determine interobserver and intraobserver reliability at multiple institutions and with different levels of training. METHODS: An online survey with digital anteroposterior and lateral radiographs was sent to 5 arthroplasty surgeons and 5 adult reconstruction fellows. The survey included 62 cases with stemmed femoral and tibial components, considered failures and pending revision, and scored by each reviewer independently using the classification system. Each case was scored in 2 separate sessions. Interobserver and intraobserver reliability was assessed using the intraclass correlation coefficient (ICC). RESULTS: Interobserver grading for both the femur (0.69) and tibia (0.72) showed strong reliability among the attendings and fellows, with slightly stronger reliability in tibia cases. The intraclass correlation coefficient (ICC) for attendings and fellows was similar overall, demonstrating consistency of the grading regardless of training level. Intraobserver comparisons showed a strong ICC for attendings and fellows in femoral cases, while fellows had near-perfect ICC in tibia cases. Across all reviewers there was on average 93% agreement within 1 grade per case with the majority of the discrepancy occurring at the metaphyseal-diaphyseal junction. CONCLUSION: This classification demonstrated overall strong interobserver and intraobserver reliability, with 93% agreement within 1 grade of bone loss. With further education, this classification system can ultimately be used to standardize the degree of bone loss in failed stemmed components and help with preoperative planning.

Patient-Specific Venous Thromboembolic Event Prophylaxis in Total Joint Arthroplasty - Literature-Supported Guidelines.

Following total joint arthroplasty (TJA), venous thromboembolic events (VTE) are a known complication that may result in increased hospitalization cost as well as morbidity. Numerous investigations have documented patient-specific factors that place an individual at increased risk of VTE after TJA. Potential risk factors for VTE include genetic predisposition, history of a prior VTE event, revision surgery and patient comorbidity factors. The American Academy of Orthopedic Surgeons and The American College of Chest Physicians have both provided recommendations for VTE prophylaxis after orthopedic surgery. However, among orthopedic surgeons, there remains a lack of consensus regarding the appropriate agent and time course for prophylactic anticoagulation after TJA. In this study, we review the evidence-supported patient-specific factors that confer an increased risk of VTE in the TJA postoperative period. Furthermore, we describe the VTE prophylaxis regimen used at our home institution after TJA for low- and high-risk patients as well as a recommendation for cessation or continuation of anticoagulation regimens that patients were on preoperatively for comorbid conditions.

Classification of Bone Loss With Failed Stemmed Components in Revision Total Knee Arthroplasty.

INTRODUCTION: With the increasing number of primary total knee arthroplasties (TKA) being performed annually there is also an expected increase in the number of revision TKA, as well as failed revision TKA with stemmed components. A new classification system based upon the location and degree of bone loss in the tibial and or femoral metaphysis and diaphysis is proposed. Type 1 has no bone loss in the metaphysis and diaphysis; Type 2 has a metaphyseal bone loss. Type 3 defects are subdivided into A and B, depending on the extent of the diaphyseal bone loss. Type 4 has extensive bone loss with an expansion of the diaphyseal cortex. METHOD: An online survey with digital anteroposterior and lateral radiographs was sent to five arthroplasty surgeons. A total of 55 cases with stemmed femoral and tibial components, considered failures and pending revision, were reviewed. By using the proposed classification system, each femoral and tibial component was scored. Interobserver reliability was determined using the intraclass correlation coefficient for pooled data. RESULTS: Comparisons between each individual reviewer demonstrated moderate to strong agreement overall for the reviewers using the classification, with an average correlation coefficient of 0.67 (95% CI [0.57 to 0.77]) for all cases, signifying a low variation in the scores of each case. Looking specifically at the femoral components, the ICC was 0.62 (95% CI [0.477 to 0.76]), while the ICC for the tibial components was 0.71 (95% CI [0.58 to 0.83]). DISCUSSION: This classification, which has demonstrated moderate to strong interobserver reliability, can help surgeons determine the degree of anticipated bone loss and approach these complex cases with a preoperative plan based upon the radiographic images. This classification system will also allow standardized communication among surgeons, categorization of procedures for comparative research, and anticipated prognosis.

Optimizing Total Knee Arthroplasty With ROSA® Robotic Technology.

A new robotic platform (ROSA® Knee system, Zimmer Biomet, Warsaw, Indiana) for total knee arthroplasty (TKA) has been created to increase precision of bony resections and knee balancing while maintaining surgeon autonomy. Our aim is to discuss: (1) the background of robotic technology in orthopedics, (2) current literature and potential benefits of the ROSA® Knee system, and the (3) optimal surgical technique for this specific robotic TKA platform. Early literature regarding this robotic system is promising as studies have shown precision of its bony resections, accuracy of overall limb alignment, and low early revision rates. There is a need for continued research on clinical outcomes using this platform, and the intention is to provide a review with insight into the potential advantages of robotics and the ideal surgical technique for successful use of this system.

Review of a Novel Antimicrobial Wound Gel System Used in Total Knee Arthroplasty Including a Protocol for a Randomized Controlled Trial at Our Institutions.

INTRODUCTION: Surgical-site infections (SSIs) remain a challenging complication following total knee arthroplasty (TKA) with estimates nearing 2%. Current antimicrobial dressing options have gained popularity despite reported bacterial resistance and ineffectiveness. Bacteria can produce an extracellular polymeric substance (EPS), thereby rendering infections difficult to treat. Recently, a novel antimicrobial wound gel system has been developed to address EPS-associated infections. This new technology is comprised of various components that act to break bonds and cross-linking within EPS, induce lysis, and provide a moist environment to promote healing. In this paper, we provide a background of: (1) wound infections; (2) biofilms; and (3) current dressing options. We will then describe a novel antimicrobial gel therapy with a summary of a randomized control trial (RCT). MATERIALS AND METHODS: We describe an RCT protocol for patients undergoing primary TKA at two large tertiary care centers. Patients will be randomized 1:1 using permutated block methodology to either standard of care (SOC) or a novel antimicrobial wound gel system, yielding 750 patients in each treatment arm. Inclusion criteria include patients scheduled to undergo primary TKA. The primary outcome is the appearance of a surgical-site complication. CONCLUSION: We briefly describe the background of wound healing and biofilm, as well as current treatment modalities including antimicrobial dressings and a novel technology developed to address the EPS component of bacteria. In addition, we describe a protocol for a randomized controlled trial examining the effects of this novel therapy on surgical-site complications in patients undergoing primary TKA.

The Effectiveness of Closed-Incision Negative-Pressure Therapy Versus Silver-Impregnated Dressings in Mitigating Surgical Site Complications in High-Risk Patients After Revision Knee Arthroplasty: The PROMISES Randomized Controlled Trial.

BACKGROUND: Revision total knee arthroplasty (rTKA) is associated with significant risk of wound-related morbidity. The present study aimed to evaluate the 1) efficacy of closed-incision negative-pressure therapy (ciNPT) vs silver-impregnated antimicrobial dressing (AMD) in mitigating postoperative surgical site complications (SSCs), 2) the effect of ciNPT vs AMD on certain postoperative health utilization parameters, and on 3) patient-reported outcomes (PROs) improvement at 90-day postoperative follow-up. METHODS: This multicenter randomized controlled trial was conducted between December 2017 and August 2019. Patients ≥22 years, at high risk for SSC, and receiving rTKA with full exchange and reimplantation of new prosthetic components or open reduction and internal fixation of periprosthetic fractures were screened for inclusion. Eligible patients were randomized to receive a commercially available ciNPT system or a silver-impregnated AMD (n = 147, each) for minimum of 5-day duration. Primary outcome was the 90-day incidence of SSCs with stratification in accordance with revision type (aseptic/septic). Secondary outcomes were the 90-day health care utilization parameters (readmission, reoperation, dressing changes, and visits) and PROs. RESULTS: Of 294 patients randomized (age: 64.9 ± 9.0 years, female: 59.6%), 242 (82.0%) patients completed the study (ciNPT: n = 124; AMD: n = 118). The incidence of 90-day SSCs was lower for the ciNPT cohort (ciNPT: 3.4% vs AMD: 14.3%; odds ratio (OR): 0.22, 95% confidence interval (0.08, 0.59); P = .0013). Readmission rates (3.4% vs 10.2%, OR: 0.30(0.11, 0.86); P = .0208) and mean dressing changes (1.1 ± 0.3 vs 1.3 ± 1.0; P = .0003) were lower with ciNPT. The differences in reoperation rates, number of visits, and PRO improvement between both arms were not statistically significant (P > .05). CONCLUSION: ciNPT is effective in reducing the 90-day postoperative SSCs, readmission, and number of dressing changes after rTKA. Recommending routine implementation would require true-cost analyses.

Protocols for the Use of a Novel Biofilm-Disrupting Wound Irrigation Solution for Prevention of Surgical-Site Infections After Total Joint Arthroplasty.

Surgical-site infections are potential complications of total joint arthroplasties. Many strategies, ranging from preoperative to postoperative, have been developed in an attempt to mitigate this morbidity. Biofilms have been implicated in difficulties of treatment. Therefore, antimicrobials have been increasingly used to combat these problems. In this report, we will summarize different protocols which utilize a new antimicrobial solution. Providing surgeons with an effective prevention option for these infections is crucial for positive outcomes and the continued advancement in the practice of total joint arthroplasty.

The Utility of Telehealth in the Recovery From the COVID-19 Pandemic.

Telehealth has recently been used more often in an attempt to protect practitioners and patients during the 2019 coronavirus infectious disease (COVID-19) crisis. Despite telehealth's existence, there was no prior need to fully realize its potential. Recently, technological innovations in orthopaedic surgery have assisted in making this modality more useful. However, it is important to continually educate the medical community regarding these technologies and their interplay to improve patient care. Therefore, our purpose is to provide information on telehealth by assessing: (1) steps the hospital/system are taking to reduce COVID-19 exposure for teams and patients; (2) new technologies allowing for the optimization of patient safety; and (3) use of telehealth for postoperative follow up. We will demonstrate that telehealth and its associated strategies can be used effectively to decrease COVID-19 exposure risks for both medical staff and patients during these rapidly changing and uncertain times.

Bundled-Care Program for the Prevention of Surgical-Site Infections Following Lower Extremity Total Joint Arthroplasty.

Surgical-site infections (SSIs) are among the most difficult-to-manage complications after lower extremity total joint arthroplasty (TJA). While the rates of most implant-related complications have decreased over time due to improvements in prosthetic materials and surgical techniques, the incidence of periprosthetic joint infections (PJIs) continues to increase. They place a tremendous economic burden on healthcare systems that is projected to reach $1.8 billion by the year 2030. A number of perioperative infection mitigation strategies exist that are often implemented concurrently to minimize the risk of these complications. A multicenter randomized controlled trial is underway to evaluate the efficacy of a bundled care program for the prevention of PJIs in lower extremity TJA. This bundle includes five infection-reduction strategies that are used pre-, peri-, and postoperatively, including: (1) povidone-iodine skin preparation and nasal decolonization; (2) iodine-alcohol surgical prepping solution; (3) iodophor-impregnated incise drapes; (4) forced-air warming blankets; and (5) negative pressure wound therapy for select patients. The aim of this review is to describe these products and their appropriate usage, review the available literature evaluating their use, and compare them with other commercially available products. Based on the available literature, each of these strategies appear to be important components for SSI-prevention protocols. We believe that implementing all five of these mitigation strategies concurrently will lead to a synergistic effect for infection control following lower extremity TJA.

Do Antibiotic-Impregnated Intramedullary Dowels Assist in Eradicating Infection in Total Knee Arthroplasty? Pro.

Antibiotic-loaded bone cement (ALBC) spacer constructs for the treatment of periprosthetic joint infections of the knee continue to evolve from the original hockey puck designs. Countless techniques have since been described for augmentation of ALBC spacers with the use of intramedullary (IM) dowels. The use of IM dowels has become a vital addition to any knee spacer construct. ALBC IM dowels are an excellent vessel to provide targeted local antibiotic treatment to high-risk areas like the medullary canal while increasing the overall therapeutic antibiotic elution. In addition, IM dowels provide needed stabilization to the relatively unstable intra-articular spacer component, thereby reducing spacer-related complications like displacement and fracture. Therefore, we recommend regular use of IM dowel augmentation to ALBC spacer constructs.

Comparison Study of Patient Demographics, Risk Factors, and Lengths of Stay for Postoperative Ileus After Primary Total Knee Arthroplasty.

BACKGROUND: Postoperative ileus is a potential complication after orthopedic surgery, which has not been well studied after total knee arthroplasty (TKA). The aims of this study were to analyze rates of postoperative ileus; patient demographic profiles; in-hospital lengths of stay (LOS); and patient-related risk factors for postoperative ileus after primary TKA. METHODS: A query was performed from January 1, 2005 to March 31, 2014 using the Medicare Standard Analytical Files. Patients who underwent primary TKA and developed postoperative ileus within 3 days after their index procedure were identified. Patients who did not develop ileus represented controls. Primary outcomes analyzed and compared included patient demographics, risk factors, and in-hospital LOS. A P value less than .05 was considered statistically significant. RESULTS: Ileus patients were older, more likely to be male, and had higher Elixhauser-Comorbidity Index scores (8 vs 6; P < .0001) compared with controls. Male patients (odds ratio [OR], 2.12; P < .0001), patients with preoperative electrolyte/fluid imbalance (OR, 3.40; P < .001), patients older than 70 years (OR, 1.62-2.33; P < .015), and body mass indices greater than 30 kg/m2 (OR, 1.79-2.00; P < .001) were at the greatest risk of developing ileus. In addition, ileus patients had significantly longer in-hospital LOS (5.42 vs 3.22 days; P < .001). CONCLUSION: The study demonstrated differences in patient demographics, patient-related risk factors, and an increased in-hospital LOS for ileus patients after primary TKA. The study is important as it can allow orthopedists to properly identify and optimize patients with certain risk factors to potentially mitigate this adverse event from occurring.

Translation and Validation of the German New Knee Society Scoring System.

BACKGROUND: In 2011 the Knee Society Score (KSS) was revised to include patient expectations, satisfaction, and physical activities as patient-reported outcomes. Since the new KSS has become a widely used method to evaluate patient status after TKA, we sought to translate and validate it for German-speaking populations. QUESTIONS/PURPOSES: After translation of the new KSS into German using established guidelines, we sought to test the new German version for (1) validity; (2) responsiveness; and (3) reliability. METHODS: The new KSS form was translated and adapted according to the available guidelines. The final version was used to validate the German version of the new KSS (GNKSS) in 133 patients undergoing TKA, of which 100 patients were included in the study as per inclusion criteria. Patients completed the GNKSS form along with the German WOMAC and the German SF-36 scores preoperatively and at the 2-year postoperative followup. Construct validity was tested by comparing domain scores of the GNKSS with domain scores of the German WOMAC and the SF-36. Responsiveness was evaluated by comparing pre- and postoperative scores in all questionnaires in all patients using standardized response means. To evaluate reliability, every second patient (n = 50) in the whole group was asked to complete the GNKSS form a second time 1 week after their 2-year followup; 39 patients responded. This sample group was considered representative after testing the difference among age, sex, body mass index, operation side, preoperative or postoperative GNKSS, and WOMAC scores with the original group. Intraclass correlation coefficients (ICCs) were used to assess reliability and Cronbach's α was an indicator of internal consistency of each domain score. RESULTS: Construct validity was excellent pre- and postoperatively between the GNKSS and the WOMAC for domains including symptoms, satisfaction, total functional score, and total score and activity subdomains, except the expectation domain and advanced and discretionary subdomains of the GNKSS and the stiffness domain of WOMAC. The expectation domain showed either no significant correlation or only weak correlations with the domains of WOMAC pre- as well as postoperatively (r ranging between -0.19 and -0.34). Correlation of the function section of the GNKSS as well as the physical function and role-physical domains of the SF-36 pre- and postoperatively were moderate to strong, respectively, with statistically significant (p < 0.001) r values of 0.49 and 0.48 preoperatively and 0.73 and 0.65 postoperatively. Correlation of the symptom section of the GNKSS and bodily pain domain of the SF-36 was also strong pre- and postoperatively. Regarding responsiveness, all domains of the GNKSS showed large changes except the expectation domain. The symptom and functional sections of the GNKSS showed higher responsiveness than the corresponding pain and function domains of the WOMAC and bodily pain and physical function domains of the SF-36. Also, the total score changes were larger for the GNKSS compared with the WOMAC. No floor or ceiling effect was observed. Reliability was excellent with ICCs of 0.83 to 0.97 as an indicator of test-retest reliability and Cronbach's α values of 0.78 to 0.85 preoperatively and 0.92 to 0.94 postoperatively as an indicator of internal consistency for all domains and subdomains. CONCLUSIONS: The GNKSS is a valid, responsive, reliable, and consistent outcome measurement tool that may be used to evaluate the outcome of TKA. LEVEL OF EVIDENCE: Level II, diagnostic study.

Adductor Canal Block or Local Infiltrate Analgesia for Pain Control After Total Knee Arthroplasty? A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Total knee arthroplasty is a treatment option for debilitating arthritis. In the postoperative period, patients experience moderate to severe pain affecting the rehabilitation, hospital stay, and patient satisfaction. This study aims at utilizing current best evidence to determine whether adductor canal block (ACB) or periarticular injection (PAI) is a better modality for managing short-term postoperative pain and opioid consumption. METHODS: Embase, MEDLINE, HealthStar, Emcare, and PubMed were searched for randomized controlled trials from 1946 to August 2018, for literature addressing the comparison of ACB and PAI for pain management in the setting of total knee arthroplasty. A systematic review and meta-analysis were performed. RESULTS: Six studies were included in our meta-analysis. When examining the combined visual analog scale (VAS) pain values for each group, analysis demonstrated greater reduction in scores for the PAI group, and the difference was statistically significant (P = .001). When comparing the VAS scores of subgroups analyzed at specific periods in time, there was a trend toward lower VAS scores in subgroups analyzed at 24 hours and 48 hours postoperatively (at rest and at movement) in the PAI group. Overall opioid consumption was lower in the PAI group, with demonstrated statistical significance (P = .03). When comparing the postoperative subgroups, there was a trend toward decreased opioid use in the PAI group, with 13.25% less opioid use at 48 hours and 9.5% less opioid use at 24 hours. CONCLUSION: PAI could significantly improve postoperative pain and opioid consumption when compared with ACB. Additional, high-quality studies are required to further address this topic.