Outcomes of Metaphyseal Cones and Stem Fixation Following Rotating Hinge in Complex Primary and Revision Total Knee Arthroplasty.

BACKGROUND: Although hinged prostheses have been used successfully in complex revision total knee arthroplasty (TKA), concerns exist regarding early failure due to aseptic loosening and other mechanical complications. The use of metaphyseal cones and hybrid cement fixation have been studied in unlinked constrained primary or revision TKA, but their impact on the survivorship of hinged prostheses has yet to be investigated. METHODS: We identified a consecutive series of 164 hinged prostheses and collected data on demographics, indications, complications, and re-revisions in patients who had fully cemented versus hybrid stems, with and without metaphyseal cones. A multivariate analysis was performed to identify independent variables associated with re-revision as the primary end point. RESULTS: In total, 84 patients (51.2%) had fully cemented stems, and 80 patients (48.8%) had hybrid stems. Cones were used in 73 patients (44.5%). At a mean follow-up of 3.4 ± 2.2 years, 42 patients underwent re-revision (25.8%), most commonly for infection (12.2%), followed by loosening (6.7%) and periprosthetic fracture (3.7%). Patients who had fully cemented stems had lower re-revision rates than hybrid fixation constructs (19 versus 26%, P = .043). Using multivariable regression, a construct with hybrid fixation with cones (odds ratio = 2.39; P = .037) was an independent risk factor for failure. Utilization of cones alone did not have an effect on re-revision rates at 3.4-year follow-up. CONCLUSIONS: While we found no difference with the use of cones, patients undergoing revision TKA with a hinge prosthesis and fully cemented stems had better overall survivorship than hybrid stems.

Randomized Trial of Static and Articulating Spacers for Treatment of the Infected Total Hip Arthroplasty.

BACKGROUND: The purpose of this randomized clinical trial is to compare perioperative and postoperative variables between static and articulating spacers for the treatment of chronic periprosthetic joint infection (PJI) complicating total hip arthroplasty (THA). METHODS: Fifty-two patients undergoing resection arthroplasty as part of a 2-stage exchange for PJI at 3 centers were randomized to either a static (n = 23) or articulating spacer (n = 29). The primary endpoint was operative time of the second-stage reimplantation and power analysis determined that 22 patients per cohort were necessary to detect a 20-minute difference. Seven patients were lost to follow-up, 4 were never reimplanted, and one died before discharge after reimplantation. Forty patients were followed for a mean 3.2 years (range 2.0-7.1). RESULTS: There were no differences in operative time at second-stage reimplantation (143 minutes static vs 145 minutes articulating, P = .499). Length of hospital stay was longer in the static cohort after stage 1 (8.6 vs 5.4 days, P = .006) and stage 2 (6.3 vs 3.6 days, P < .001). Although it did not reach statistical significance with the numbers available for study, nearly twice as many patients in the static cohort were discharged to an extended care facility after stage 1 (65% vs 30%, P = .056). CONCLUSION: This randomized trial demonstrated that the outcomes of static and articulating spacers are similar in the treatment of THA PJI undergoing 2-stage exchange arthroplasty. The significantly longer length of hospital stay associated with the use of static spacers may have important economic implications for the health care system.

Accuracy and Validity of Computer Adaptive Testing for Outcome Assessment in Patients Undergoing Total Knee Arthroplasty.

BACKGROUND: Computerized adaptive test (CAT) questionnaires may allow standardization of patient-reported outcome measures and reductions in questionnaire burden. We evaluated the validity, accuracy, and efficacy of a CAT system in patients with end-stage osteoarthritis undergoing total knee arthroplasty. METHODS: CAT Knee Osteoarthritis Outcome Scores (KOOS) and CAT KOOS-JR questionnaires were applied to 1871 standard form KOOS and 1493 KOOS-JR patient responses, respectively. Mean, standard deviations, Pearson's correlation coefficients, interclass correlation coefficients (ICCs), frequency distribution plots, and Bland-Altman plots were used to compare the precision, validity, and accuracy between CAT scores and full-form scores. RESULTS: There was a mean reduction of 14 questions (33%) in the CAT KOOS and 1.4 questions (20%) with the CAT KOOS-JR version, compared with the standard KOOS and KOOS-JR surveys, respectively. There were no significant differences between KOOS and CAT KOOS scores with respect to pain (P = .66), symptoms (P = .43), quality of life (P = .99), activities of daily living (P = .68), and sports (P = .84). Similarly, there were no significant differences between the standard form KOOS-JR and CAT KOOS-JR scores (P = .94). There were strong correlations with minimal variability between the CAT KOOS and standard KOOS questionnaires for pain (r = 0.98, ICC: 0.98), symptoms (r = 0.97, ICC: 0.97), quality of life scores (r = 0.99, ICC: 0.99), activities of daily living scores (r = 0.99, ICC: 0.99), and sports scores (r = 0.99, ICC: 0.99). Similarly, there were strong correlations between the KOOS-JR and the CAT KOOS-JR scores (r = 0.99, ICC: 0.99). CONCLUSION: CAT KOOS and the CAT KOOS-JR versions are accurate and reduce questionnaire burden up to one-third compared with standard surveys. CAT versions may improve patient compliance and decrease fatigue.

Accuracy and Validity of Computer Adaptive Testing for Outcome Assessment in Patients Undergoing Total Hip Arthroplasty.

BACKGROUND: Probability-based computer algorithms that reduce patient burden are currently in high demand. These computer adaptive testing (CAT) methods improve workflow and reduce patient frustration, while achieving high measurement precision. In this study, we evaluated the accuracy and validity of the CAT Hip Disability and Osteoarthritis Outcome Score (HOOS) and the Hip Disability and Osteoarthritis Outcome Score Joint Replacement (HOOS-JR) by comparing them to the full version of these scoring systems in a subset of patients who had undergone total hip arthroplasties. METHODS: A previously developed CAT HOOS and HOOS-JR was applied to 354 and 1547 HOOS and HOOS-JR patient responses, respectively. Mean, standard deviations, Pearson's correlation coefficients, interclass correlation coefficients, frequency distribution plots, and Bland-Altman plots were used to compare the precision, validity, and accuracy between CAT scores and full-form scores. RESULTS: By modifying the questions to past responses, the CAT HOOS demonstrated a mean reduction of 30% of questions (28 vs 40 questions). There were no significant differences between the full HOOS and CAT HOOS with respect to pain (P = .73), symptoms (P = .94), quality of life (P = .99), activities of daily living (P = .82), and sports (P = .99). There were strong linear relationships between the CAT versions and the standard questionnaires (r > 0.99). The Bland-Altman plot showed that differences between CAT HOOS and full HOOS were independent of the overall scores. CONCLUSION: The CAT HOOS and HOOS-JR have high correlation and require fewer questions to finish compared to the standard full-form questionnaires. This may represent a reliable and practical alternative that may be less burdensome to patients and may help improve compliance for reporting outcome metrics.

Conversion Total Knee Arthroplasty is Associated with Increased Post-Acute Care Costs.

BACKGROUND: Alternative payment models have been viewed as successfully decreasing costs following primary total knee arthroplasty (TKA) while maintaining quality. Concerns exist regarding access to care for patients who may utilize more resources in a bundled payment arrangement. The purpose of this study is to determine if patients undergoing conversion of prior surgery to TKA have increased costs compared to primary TKA patients. METHODS: Claims from Medicare and a single private insurer were queried for all primary TKA patients at our institution from 2015 to 2016. Ninety-day post-acute care costs were compared between primary and conversion TKA. Secondary endpoints included discharge disposition, complications, and readmissions. A multivariate regression analysis was performed to identify independent risk factors for increased post-acute care costs and short-term outcome metrics. RESULTS: Of 3999 primary TKA procedures, 948 patients (23%) underwent conversion TKA. Conversion TKA was associated with greater post-acute care costs in patients with commercial insurance ($4714 vs $3759, P = .034). Among Medicare beneficiaries, prior ligament reconstruction was associated with increased post-acute care costs ($1917 increase, P = .036), while prior fracture fixation approached statistical significance ($2402 increase, P = .055). Conversion TKA was an independent risk factor for readmissions (odds ratio 1.46, 95% confidence interval 1.00-2.17, P = .050), while patients with a prior open knee procedure had higher rates of complications (odds ratio 2.41, 95% confidence interval 1.004-5.778, P = .049). CONCLUSION: Our data suggest that conversion from prior knee surgery to TKA is associated with increased 90-day post-acute care costs and resource utilization, particularly prior open procedures. Without appropriate risk adjustment in alternative payment models, surgeons may be financially deterred from providing quality arthroplasty care given the reduced net payment and surgical complexity of such cases.

Conversion Total Knee Arthroplasty Needs Its Own Diagnosis-Related Group Code.

BACKGROUND: Conversion from a prior knee procedure has been demonstrated to require greater operative times and resources, but still lacks a separate procedural or facility code from primary total knee arthroplasty (TKA). The purpose of this study is to determine differences in facility costs between patients who underwent primary TKA and those who underwent conversion TKA. METHODS: We retrospectively reviewed a consecutive series of patients undergoing primary TKA at 2 hospitals from 2015 to 2017, comparing itemized facility costs between primary and conversion TKA patients. A multivariate regression analysis was performed to identify independent risk factors for increased facility costs, the need for additional implants, length of stay, and discharge disposition. RESULTS: Of 2447 TKA procedures, 678 (27.7%) underwent conversion TKA, which was associated with greater implant costs ($3931.47 vs $2864.67, P = .0120) and total facility costs in a multivariate regression ($94.30 increase, P = .0316). When controlling for confounding variables, patients with a prior ligament reconstruction ($402 increase, P = .0002) and prior open reduction and internal fixation ($847 increase, P = .0020) had higher costs and were more likely to require stemmed implants (P < .05). There was an increase in TKA implant cost by $538 in patients with implants from a prior procedure (P < .0001). CONCLUSION: Conversion TKA is associated with greater implant and inpatient facility costs than primary TKA, particularly those who had a history of an open knee procedure. A separate diagnosis-related group should be created for conversion TKA given the increased cost and complexity of these procedures compared to primary TKA.

A Current Procedural Terminology Code for "Knee Conversion" Is Needed to Account for the Additional Surgical Time Required Compared to Total Knee Arthroplasty.

BACKGROUND: Previous knee injury requiring surgical intervention increases the rate of future arthroplasty. Coding modifiers for removal of previous hardware or increased complexity offer inconsistent results. A Current Procedural Terminology code for knee conversion does not currently exist as it does for conversion hip arthroplasty. We investigate the extra time associated with conversion knee arthroplasty. METHODS: Sixty-three total knee arthroplasty (TKA) cases in the setting of previous knee hardware were identified from our institution between 2008 and 2015. Knee conversions were matched to primary TKA by age, gender, body mass index, Charlson Comorbidity Index, and surgeon, in a 3:1 ratio. Patients who underwent knee conversions were compared to matched TKA with regard to operative time, length of stay, discharge destination, readmission, and repeat procedures within 90 days from index procedure. RESULTS: The mean operating room time for primary TKA was 71.7 minutes (range 36-138). The mean operating room time for knee conversion was significantly greater by an additional 31 minutes; mean 102.1 minutes (range 56-256 minutes, P < .0001). Rates of readmission, 0.5% vs 3.2%, and repeat procedures, 5.3% vs 12.7%, within 90 days were greater for knee conversions. There was no difference in length of stay or discharge destination. CONCLUSION: Total knee conversion results in a 43% increase in operative time and more than twice the rate of readmission and repeat procedures within 90 days compared to TKA. This suggests the need for an additional Current Procedural Terminology code for knee conversion arthroplasty to compensate surgeons for the extra time required for conversions.

Aspirin Can Be Used as Prophylaxis for Prevention of Venous Thromboembolism After Revision Hip and Knee Arthroplasty.

BACKGROUND: The optimal prophylaxis for prevention of venous thromboembolic events (VTEs) after revision total joint arthroplasty (TJA) remains unknown. The objective of this study was to evaluate whether aspirin, known to be effective for prevention of VTEs after primary arthroplasty, is also effective after revision TJA. METHODS: We studied 2997 consecutive patients who underwent revision TJA between 2005 and 2013 and were treated with intermittent pneumatic compression devices and either aspirin (534 patients) or warfarin (2463 patients) for VTE prophylaxis. Pertinent data including the incidence of symptomatic VTEs, bleeding events, infection, and mortality were retrieved from our prospectively collected database. RESULTS: The incidence of symptomatic VTEs was significantly higher in the warfarin group at 1.75% (43 of 2463) compared with 0.56% (3 of 534) in the aspirin group (odds ratio: 3.2; 95% CI: 1.03-16.3; P = .03). There was a higher rate of bleeding events with administration of warfarin (1.5%) compared with aspirin (0.4%; P = .02; odds ratio: 4.1; 95% CI: 1.2-34.0). The rate of surgical site infection was similar between the aspirin group and the warfarin group (1.61% and 1.70%, respectively). CONCLUSION: Administration of aspirin as prophylaxis against VTEs after revision arthroplasty may be a viable option as it appears to be more effective than warfarin in prevention of symptomatic VTEs and is associated with a lower rate of complications.

Medicare fails to compensate additional surgical time and effort associated with revision arthroplasty.

In comparison to primary total knee arthroplasty, surgical time was 1.8 times greater for all knee revisions and 2.4 times greater for complex knee revisions. Knee revisions had an 8.5% higher rate of 90-day repeat procedures. In comparison to primary total hip arthroplasty, surgical time was 1.8 greater for all hip revisions and 2.6 fold greater for complex hip revisions. Hip revisions had a 3.4% higher rate of 90-day repeat procedures. Practices based on revisions or complex revisions alone would see a 32% and 50% decrease in reimbursement respectively compared to the ones based on primary arthroplasty. The projected future increase in primary arthroplasties and the relative incentive to perform primary arthroplasty may soon put patient access to physicians willing to perform revision arthroplasty at risk.

Dental clearance prior to elective arthroplasty may not be needed for everyone.

We investigated the prevalence and risk factors for preoperative dental clearance failure in joint arthroplasty patients. Over a 5-month period, all patients scheduling total joint arthroplasty completed a dental questionnaire. Data collected included demographics, medical and dental history, dental hygiene practices, frequency of dental care, and results of dental clearance. Of the 300 patients, 35 (12%) failed dental clearance. Risk factors included tobacco use, poor flossing habits, history of tooth extraction, age, narcotic use, and lack of a dentist visit within 12 months. Of 189 patients who lacked the 3 least prevalent risk factors (tobacco use, narcotic use, no dental visit within 12 months), 11 (6%) failed dental clearance. Selective dental clearance based on patient risk stratification may be a reasonable approach.

Head computed tomography is not useful for evaluating patients change in mental status following total joint arthroplasty.

We retrospectively reviewed 187 patients who presented with neurologic abnormality after total joint arthroplasty to establish the incidence of diagnosed organic brain disorders in these patients and determine the utility of advanced head imaging studies. 139 of 187 (74.3%) patients underwent imaging for altered mental status (AMS) and 48 patients for a focal neurologic deficit (FND). Acute findings on head imaging were more common in the FND group. The incidence of stroke and transient ischemic attack was significantly lower in the AMS group compared to FND group (Stroke: 0% vs 12.5%, p < 0.001; TIA: 0% vs. 16.7%, P < .001). Advanced head imaging for evaluation of TJA patients with a change in mental status is of low yield. An algorithm for evaluation of these patients is proposed.

Clostridium difficile is common in patients with postoperative diarrhea after hip and knee arthroplasty.

Clostridium difficile is an antibiotic-associated gastrointestinal infection that has detrimental consequences. We sought to determine the incidence of C. difficile in TJA patients with postoperative diarrhea, to determine risk factors for C. difficile infection, and to establish the incidence of C. difficile-related complications. Our institutional protocol includes screening for C. difficile in all patients with diarrhea after TJA. We identified 121 such patients over four years with twenty-eight (23%) testing positive for C. difficile. Revision arthroplasty and prolonged postoperative antibiotic use were risk factors for C. difficile infection. With our protocol of screening and immediate treatment of C. difficile positive patients, we found no C. difficile-associated complications.

Surprise Billing Is Common in Total Joint Arthroplasty and Negatively Impacts Patient Satisfaction.

BACKGROUND: Patients undergoing total joint arthroplasty (TJA) may receive unexpected medical bills. Such "surprise" bills may cause financial hardship for patients, which prompted policymakers to pass the No Surprises Act. The purpose of this study was to determine the incidence of surprise bills for patients undergoing TJA and the effect of surprise billing on patient satisfaction. MATERIALS AND METHODS: This was a retrospective study of patients who underwent a primary total hip arthroplasty (THA) or total knee arthroplasty (TKA) at a large multi-state institution. Patients completed a questionnaire regarding the incidence of surprise bills after their surgery, details of those bills, and how the bills affected their surgical satisfaction. Independent predictors for receiving a surprise bill were assessed through a multivariate regression analysis. RESULTS: Twelve percent of participants received at least one surprise bill after their TJA. The most common surprise bill came from the surgical facility (48%), followed by anesthesia (36%). Multivariate logistic regression analysis identified older age and Black race to be independent predictors of surprise billing. Furthermore, surgery occurring after the No Surprises Act bill enforcement on January 1, 2022, was found to increase a patient's likelihood of receiving a surprise bill (P=.039, effect size=0.18). Patients who received a surprise bill reported being significantly less satisfied with their surgery (P=.002, effect size=0.45). Forty-nine percent of patients with a surprise bill felt their billing negatively affected their surgical satisfaction. CONCLUSION: Surprise billing continues to occur after TJA and can negatively affect patient satisfaction. Although surgeons may be unable to limit the amount of bills patients receive postoperatively, increased communication and education regarding the perioperative billing process may prove to be beneficial for both patient satisfaction and the physician-patient relationship. [Orthopedics. 20XX;4X(X):XXX-XXX.].

Staphylococcus aureus colonization among arthroplasty patients previously treated by a decolonization protocol: a pilot study.

BACKGROUND: Although testing and treatment for Staphylococcus aureus colonization before total joint arthroplasty (TJA) are well described and understood, the durability of decolonization has not been studied extensively. QUESTIONS/PURPOSES: The purpose of this pilot study is to determine the percentage of arthroplasty patients with S. aureus colonization despite previous decolonization at the time of TJA. METHODS: Over a 2-year period, all patients having TJA by one surgeon were screened and treated for nasal S. aureus. Of 634 patients, 139 had methicillin-sensitive S. aureus (15%) or methicillin-resistant S. aureus (6.6%) colonization before TJA. Fifty-eight of these 139 patients (42%) were retested at 3 to 30 months for persistent colonization by nasal culture. Data collection included age at time of TJA, type of TJA, and time from TJA to repeat testing. We performed no clonal analysis for strains. RESULTS: Thirty-nine of the 58 patients (67%) decolonized before surgery were negative on retesting and 19 (33%) were again positive for S. aureus colonization. Of the 19 patients who retested positive for colonization, 17 (89%) were colonized by bacteria with unchanged antibiotic sensitivity. CONCLUSIONS: We demonstrate that 33% (19 of 58) of postoperative arthroplasty patients test positive for S. aureus colonization at 3 to 30 months after surgery despite preoperative decolonization. Arthroplasty surgeons must be aware that a decolonization treatment does not guarantee that a patient will remain decolonized in the future. Although unchanged antibiotic sensitivity in 89% of these patients suggests a substantial role for persistence as opposed to eradication and repeat colonization, we were unable to retrospectively perform clonal analysis to confirm this conclusion. This group of patients demonstrating continued colonization with S. aureus after arthroplasty deserves further study, because it remains unclear whether there is a higher risk of late infection in this population. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

The routine use of atypical cultures in presumed aseptic revisions is unnecessary.

BACKGROUND: In presumed aseptic hip and knee revisions, it is common practice to send intraoperative cultures to screen for occult infection. Currently no guidelines exist for the routine use of acid-fast bacillus (AFB) and fungal cultures in this setting. QUESTIONS/PURPOSES: We established (1) the rate of positive fungal and AFB cultures in aseptic hip and knee revision arthroplasties, (2) factors associated with positive fungal and AFB cultures, (3) the likelihood that positive cultures represent true-positive results, and (4) the hospital charges of sending fungal and AFB cultures routinely. METHODS: We retrospectively evaluated all 1717 presumed aseptic hip and knee revisions performed from January 2006 to November 2011: 1139 patients had at least one intraoperative fungal culture and 1133 patients had at least one intraoperative AFB culture, with 923 and 920, respectively, achieving 1-year followup. The Musculoskeletal Infection Society criteria were used to classify subsequent infections. We attempted to identify risk factors for positive cultures. RESULTS: We observed six (0.5%) patients with positive AFB cultures and 19 (1.7%) with positive fungal cultures. Patients undergoing reimplantation procedures were more likely to have a positive fungal culture. The true-positive rate was 0% and 0.1% for AFB and fungal cultures, respectively. The total hospital charges for these cultures over the time frame of our study were USD 1,315,533. CONCLUSIONS: Given the extremely low rate of true-positive AFB and fungal cultures in presumed aseptic revision joint arthroplasty and the charges associated with maintaining these cultures, we believe their routine use is unwarranted. LEVEL OF EVIDENCE: Level III, prognostic study. See the Instructions for Authors for a complete description of evidence.

Negative pressure wound therapy is associated with resolution of incisional drainage in most wounds after hip arthroplasty.

BACKGROUND: Persistent wound drainage after hip arthroplasty is a risk factor for periprosthetic infection. Negative pressure wound therapy (NPWT) has been used in other fields for wound management although it is unclear whether the technique is appropriate for total hip arthroplasty. QUESTIONS/PURPOSES: We determined (1) the rate of wound complications related to use of NPWT for persistent incisional drainage after hip arthroplasty; (2) the rate of resolution of incisional drainage using this modality; and (3) risk factors for failure of NPWT for this indication. METHODS: In a pilot study we identified 109 patients in whom NPWT was used after hip arthroplasty for treating postoperative incisional drainage between April 2006 and April 2010. On average, the NPWT was placed on postoperative Day 3 to 4 (range, 2-9 days) and applied for 2 days (range, 1-10 days). We then determined predictors of subsequent surgery. Patients were followed until failure or a minimum of 1 year (average, 29 months; range, 1-62 months). RESULTS: Eighty-three patients (76%) had no further surgery and 26 patients (24%) had subsequent surgery: 11 had superficial irrigation and débridement (I&D), 12 had deep I&D with none requiring further surgery, and three ultimately had component removal. Predictors of subsequent surgery included international normalized ratio level greater than 2, greater than one prior hip surgery, and device application greater than 48 hours. There were no wound-related complications associated with NPWT. CONCLUSIONS: The majority of our patients had cessation of wound drainage with NPWT. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Local Anesthesia Approach for Percutaneous Screw Fixation of an Impacted Subcapital Femoral Neck Fracture: A Technique for High-Risk Patients.

Elderly, frail patients and those who have substantial medical co-morbidities who sustain hip fractures present a challenging problem for treatment as they are at very high risk for complications from surgical intervention. The functional outcomes, pain levels, and mortality rates all worsen when non-surgical treatment is used. The safety of administering general or spinal anesthesia may be a concern in certain cases. Other modalities, such as epidural or caudal anesthesia, may be an option; however, the use of local anesthesia may be advantageous for patients with non-displaced and impacted femoral neck fractures undergoing surgical intervention. We present a case report describing the successful treatment of an elderly male who had relative contraindications to spinal anesthesia and high risk for general anesthesia and was successfully treated with percutaneous screw fixation of a femoral neck fracture using local anesthesia with a light, monitored anesthetic.

Bilateral Patellar Tendon Rupture Following Total Knee Arthroplasty in a Patient With Alkaptonuria: A Case Report.

Alkaptonuria (AKU) is a rare hereditary disorder of tyrosine degradation. The disorder is characterized by the accumulation of a pigment called homogentisic acid. Its accumulation can lead to the breakdown of connective tissue, including tendons. This report presents a 46-year-old male with a history of bilateral total knee arthroplasty (TKA) who sustained bilateral patellar tendon rupture after an acute injury. A single-stage bilateral knee revision with direct repair of the extensor mechanism augmented with Achilles allograft was performed. The procedure was successful, and the patient had an excellent post-operative outcome at one year post-operatively. This case attempts to highlight the possible complications from AKU in order to better counsel patients with this condition who are undergoing TKA.