Showing papers in "Arthroplasty today in 2018"

Intrawound vancomycin in primary hip and knee arthroplasty: a safe and cost-effective means to decrease early periprosthetic joint infection.

Abstract: Background Periprosthetic joint infection (PJI) is a devastating complication after hip and knee arthroplasty Intrawound vancomycin has been described extensively in the spine literature; however, information regarding use in arthroplasty is limited We investigate the efficacy and safety of intrawound vancomycin in arthroplasty surgery Methods All primary total hip and knee arthroplasty cases (n = 460) performed by a single surgeon from April 2016 to October 2017 were reviewed Starting in October 2016, intrawound vancomycin was used in all total joints Baseline characteristics, infection rates, 90-day readmission, and other complications were compared between untreated subjects and those who received intrawound vancomycin In addition, cost data were considered Mean follow-up durations for the control and vancomycin groups were 113 and 77 months, respectively Results Baseline characteristics and comorbidities were similar for the control (n = 112) and vancomycin groups (n = 348) The vancomycin cohort demonstrated decreased both overall infection rate (057% vs 27%; P = 031) and PJI rate (029% vs 27%; P = 009) compared with the untreated group There was no statistical difference in incidence of ototoxicity or acute kidney injury Although there was no difference in overall 90-day readmission rate, the vancomycin subset demonstrated lower readmission rate due to infection (057% vs 27%; P = 031) Based on the cost of vancomycin powder and calculated number needed to treat (NNT = 475), the cost to prevent 1 infection with the addition of intrawound vancomycin was $816 Conclusions These findings suggest that intrawound vancomycin may be a safe, cost-effective means that shows promise in reducing PJI in early follow-up Future prospective studies are warranted

What are the incidence and risk factors of in-hospital mortality after venous thromboembolism events in total hip and knee arthroplasty patients?

Abstract: Background Pulmonary embolism and deep vein thrombosis, together referred to as venous thromboembolism (VTE), are serious and potentially preventable complications after total hip arthroplasty and total knee arthroplasty. The aim of this study was to investigate the incidence of mortality after VTE events and assess the risk factors that are associated with it. Methods The Nationwide Inpatient Sample was used to estimate the total number of total hip arthroplasty, total knee arthroplasty, VTE events, and mortality using the International Classification of Diseases, Ninth Revision procedure codes from 2003 to 2012. Patients' demographics, Elixhauser, and Charlson comorbidity indices were used to identify the risk factors associated with in-hospital VTEs and mortality. Results A total of 1,805,621 THAs and TKAs were included. The overall rate of VTE was 0.93%. The in-hospital mortality rate among patients with VTEs was 7.1% vs 0.30% in patients without VTEs (P-value Conclusions In-hospital VTE has a significant in-hospital mortality rate. Several of the identified risk factors in this study are modifiable preoperatively. We strongly urge the orthopaedic community to be cognizant of these risk factors and emphasize on optimizing patients' comorbidities before an elective arthroplasty.

Postoperative prophylactic antibiotics in total joint arthroplasty

Abstract: The Center for Disease Control and Prevention recently released their 2017 Guideline for the Prevention of Surgical Site Infection. One of their recommendations is the ordering of a single dose of preoperative prophylactic antibiotics with no subsequent postoperative dosing; this recommendation includes perioperative antibiotics for patients undergoing total joint arthroplasty. At this time, the American Association of Hip and Knee Surgeons (AAHKS) does not agree with this recommendation vis-a-vis total joint arthroplasty because it contradicts current international standards of care with limited evidence and study. AAHKS still recommends postoperative antibiotics and recommends further research. Both the Board of Counselors and Board of Specialty Societies of the American Academy of Orthopaedic Surgeons have endorsed this AAHKS recommendation through an advisory opinion; the American Academy of Orthopaedic Surgeons Board of Directors adopted that advisory opinion in June 2017. A 2017 Foundation for Arthroplasty Research and Education prospective, randomized study is being undertaken to provide level I evidence for or against single-dose vs 24-hour antibiotic prophylaxis in primary total knee arthroplasty.

Is it safe? Outpatient total joint arthroplasty with discharge to home at a freestanding ambulatory surgical center.

Abstract: Background Total joint arthroplasty (TJA) is trending toward shorter hospitalizations; as a result, there are many ambulatory surgical centers (ASCs) starting to perform outpatient TJA. However, there are limited studies examining the safety of outpatient TJA in the freestanding ASC setting. This study aims to evaluate 30-day and 90-day complication rates in patients who underwent outpatient TJA at a freestanding, independent ASC with direct discharge to home. Methods A retrospective cohort review using health records was performed on the first 115 TJAs performed between August 2015 and March 2017 by one of the 4 orthopedic surgeons. Before the first TJA, the ASC had developed a multidisciplinary TJA pathway. Results Of the 115 TJAs, 37 (32%) were total hip arthroplasties (THAs), 53 (46%) total knee arthroplasties (TKAs), and 25 (22%) unicompartmental knee arthroplasties, with a mean age of 57 ± 7 years and body mass index of 30 ± 5 kg/m2. There were no intraoperative or direct ASC-related complications. There was 1 instance (0.9%) of a postoperative minimally displaced intertrochanteric femur fracture after THA due to a fall treated nonoperatively complication within 30 days of surgery. Of the 90-day complication events, there were 2 patients (2%) with postoperative arthrofibrosis of the knee after TKA requiring manipulation under anesthesia, 1 postoperative patellar tendon rupture during therapy after TKA requiring surgical repair and 1 delayed hematogenous infection after international travel after THA requiring 2-staged exchange. Conclusions Outpatient TJA with discharge to home at a freestanding, independent ASC is a safe option after development of a multidisciplinary TJA pathway.

Arthroplasty care redesign related to the Comprehensive Care for Joint Replacement model: results at a tertiary academic medical center

Abstract: Background Total joint arthroplasty (TJA) remains the highest expenditure in the Centers for Medicare and Medicaid Services (CMS) budget. One model to control cost is the Comprehensive Care for Joint Replacement (CJR) model. There has been no published literature to date examining the efficacy of CJR on value-based outcomes. The purpose of this study was to determine the efficacy and sustainability of a multidisciplinary care redesign for total joint arthroplasty under the CJR paradigm at an academic tertiary care center. Methods We implemented a system-wide care redesign, affecting all patients who underwent a total hip or total knee arthroplasty at our academic medical center. The main study outcomes were cost (to CMS), discharge destination, complications and readmissions, and length of stay (LOS); these were measured using the 2017 initial CJR reconciliation report, as well as our institutional database. Results The study included 1536 patients (41% Medicare). Per-episode cost to CMS declined by 19.5% to 11% below the CMS-designated national target. Home discharge increased from 62% to 87%. CMS readmissions declined from 15% to 6%; major complications decreased from 2.3% to 1.9%; and LOS declined from 3.6 to 2.1 days. Conclusions A mandatory episode-based bundled-payment program can induce favorable changes to value-based metrics, improving quality and outcomes for health-care consumers. Quality and value were improved in this study, evidenced by lower 90-day episode cost, more home discharges, lower readmissions and complications, and shorter LOS. This approach has implications not just for CMS, but for private payers, corporate health programs, and fixed-budget health-care models.

Early aseptic loosening of the Tritanium primary acetabular component with screw fixation

Abstract: Ultraporous acetabular components were developed to improve osseointegration and fit for increased longevity and better outcomes after total hip arthroplasty. There is a paucity of literature detailing this acetabular component's clinical performance, with even less detailing those with screw fixation. We identify 5 patients at our institution who underwent revision total hip arthroplasty for early aseptic acetabular cup loosening of an ultraporous acetabular component known as the Tritanium primary cup with secondary screw fixation. They all presented with groin and hip pain after index surgery and underwent follow-up radiographic examination consistent with component loosening requiring revision surgery. This case series reports on the risk of early acetabular cup loosening and its associated clinical presentation, workup, and surgical management in patients with the Tritanium primary cup augmented with screws.

What can the surgeon do to reduce the risk of junction breakage in modular revision stems

Abstract: Modular revision stems are very common in hip arthroplasty, but junction fracture remains a known failure mechanism. A review of the literature with description of cases with junction breakage of modular revision stems showed that in all 24 analyzed cases, there was a common finding: the combination of an effective osteointegration of the distal component and missing medial bone support of the proximal component. The result was a bending stress point of the stem construction in the region of the junction. A technique using the combination of short distal component and longer proximal components may alter this stress pattern, allow proximal implant support, and reduce the risk of junction fracture. Moreover, filling of gaps between the modular component and the medial region of the femoral calcar in endofemoral implantation, a double osteotomy in significant bowed femurs, and treating medial bone defects with structural allografts additionally can reduce the risk of junction breakage.

Association of rapidly destructive osteoarthritis of the hip with intra-articular steroid injections

Abstract: Background To assess the relationship between rapidly destructive osteoarthritis (RDOA) of the hip and intra-articular steroid injections. Methods Coding records from 2000 to 2013 were used to identify all subjects who had a fluoroscopy-guided intra-articular hip injection to treat pain associated with primary osteoarthritis. Radiographic measurements from preinjection and postinjection imaging were evaluated with Luquesne's classification of RDOA to determine diagnosis (greater than 50% joint space narrowing or greater than 2 mm of cartilage loss in 1 year with no other forms of destructive arthropathy). Demographic information, health characteristics, and number of injections were collected and analyzed as other potential explanatory variables. Patient outcome assessed by need for total hip arthroplasty (THA) after injection was also recorded. Results One hundred twenty-nine injection events met the inclusion criteria in a total of 109 patients. From this sample, 23 cases of RDOA were confirmed representing a 21% incidence of RDOA. Twenty-one of the patients (91%) with RDOA had a THA at a median time of 10.2 months (interquartile range: 6.5-11.2) compared with 27 (31%) of those without RDOA at a median time of 24.9 months (interquartile range: 15.3-65.3). Older patients, patients with more severe osteoarthritis, and patients who identified themselves as white were more likely to have a diagnosis of RDOA ( P = .008; P = .040; P = .009, respectively). Conclusions The potential for RDOA and faster progression to THA raises questions about the use of intra-articular steroid injections for hip osteoarthritis and should be discussed with patients. Additional studies are needed to define a true relationship.

Single-dose lidocaine spinal anesthesia in hip and knee arthroplasty.

Abstract: Background With the increasing interest in fast recovery and outpatient joint arthroplasty, short-acting local anesthetic agents and minimal narcotic use are preferred. Lidocaine is a fast-onset, short-duration local anesthetic that has been used for many years in spinal anesthesia. However, lidocaine spinal anesthesia has been reported to have a risk of transient neurologic symptoms (TNSs). The purpose of this study is to determine the safety and efficacy of single-dose lidocaine spinal anesthesia in the setting of outpatient joint arthroplasty. Methods We performed a prospective study on 50 patients who received lidocaine spinal anesthesia in the setting of outpatient hip and knee arthroplasty. All patients received a single-shot spinal injection, with 2% isobaric lidocaine along with titrated propofol sedation. We evaluated demographic data, length of motor blockage, time to ambulation, time to discharge readiness, patient-reported symptoms of TNS. Results Of the 50 patients studied, 11 had total hip arthroplasty, 33 total knee arthroplasty, 5 unicompartmental knee arthroplasty, and 1 underwent isolated polyethylene liner exchange in a total knee arthroplasty. The average total duration of motor blockade was 2.89 hours (range 1.73-5.17, standard deviation 0.65). Average time from postanesthesia care unit to return of motor function was 0.58 hours (range 0-1.5, standard deviation 0.48). None of the patients reported TNS. Conclusions Isobaric lidocaine spinal anesthesia appears to be a safe and effective regimen for outpatient hip and knee arthroplasty. All patients were discharged on the day of surgery with isobaric lidocaine spinal injection. There were no reports of TNSs.

The interaction of depression and prior opioid use on pain and opioid requirements after total joint arthroplasty

Abstract: Background Preoperative opioid use causes increased pain and opioid requirements after total joint arthroplasty (TJA), but the effect of depression on this relationship is not well defined. Methods We conducted a retrospective review of primary TJA patients using an institutional database. Demographic variables, inpatient opioid requirements, and discharge prescription quantities were collected and compared between patients with and without a prior diagnosis of depression in both the prior opioid-using and nonusing cohorts. Results Four hundred and three patients were analyzed between August 1, 2016, and July 31, 2017. Among prior opioid users, patients with depression experienced higher inpatient pain levels (4 vs 3; P = .001), required more inpatient opioids (117 oral morphine equivalents [OMEs] vs 70 OMEs; P = .022), were prescribed more opioids at discharge (1163 OMEs vs 750 OMEs; P = .02), and required more long-term opioid refills (57.7% vs 15.4%; P Conclusions Depression is not associated with increased pain or opioid requirements among opioid-naive patients after TJA but is associated with significantly higher pain and opioid requirements among patients who use opioids preoperatively. The interaction of these variables may highlight a target for preoperative counseling and risk modification in the arthroplasty population.

Identifying the period of greatest blood loss after lower limb arthroplasty

Abstract: Background The use of tranexamic acid (TXA) in total hip replacement (THR) typically reduces blood loss by approximately 400 mL, and typical total blood loss is still approximately 1 L. A barrier to harnessing the full potential of TXA is disagreement on the optimum timing of administration. To address this, we aimed to identify the period of greatest blood loss. Methods We analyzed the perioperative data of 870 patients who had undergone THR, total knee replacement, or unicompartmental knee replacement just before the introduction of TXA to our unit. Total blood loss was calculated on postoperative day (POD) 1 and POD2 using an equation based on change in hematocrit. Results Average total blood loss at POD2 was 1505, 1322, and 611 mL for THR, total knee replacement, and unicompartmental knee replacement, respectively. Between 86% and 96% of this blood loss occurred in the period between skin closure and POD1. Intraoperative loss did not correlate with total loss at POD2. Blood transfusion was more likely if the patient was female (odds ratio [OR], 6.8) or if they had preoperative anemia (OR, 8.3) than if there was a high-volume blood loss (OR, 1.6). Conclusions Approximately 90% of blood loss occurs between skin closure and the first postoperative 24 hours. "Intraoperative blood loss" and "transfusion rate" are not reliable markers of total blood loss. The full potential of TXA could be harnessed by using it during the period of greatest blood loss, that is, during the first postoperative 24 hours.

Cost and determinants of acute kidney injury after elective primary total joint arthroplasty

Abstract: Background Acute kidney injury (AKI) is a serious complication after major surgery, which may lead to increased morbidity and mortality. The aim of this study was to identify cost and determinants of AKI after total joint arthroplasty. Methods A retrospective case-controlled study was conducted with 1719 primary elective total hip or knee replacements performed from January 2004 through September 2015 at an urban teaching hospital. Patients who developed AKI were matched in a 1:3 ratio with those in a control group who did not develop AKI based on age, sex, race, operated joint, and comorbidities including hypertension and diabetes. Increased postoperative serum creatinine was considered indicative of AKI. Results Fifty-four patients (3.1%) had AKI that was significantly associated with increased length of hospital stay (8.07 days) compared with that of the control group (4.50 days, P Conclusions Health-care providers and patients should work together to manage risk factors and to lower the risk of morbidity and mortality, longer in-hospital stay, and high associated costs of AKI.

Salvage of failed internal fixation of intertrochanteric hip fractures: clinical and functional outcomes of total hip arthroplasty versus hemiarthroplasty.

Abstract: Background Failed internal fixation of intertrochanteric (IT) hip fractures presents a significant challenge in the elderly, osteoporotic population. Conversion total hip arthroplasty (cTHA) and hemiarthroplasty (cHA) are both accepted salvage operations for failed IT fracture fixation, though limited clinical data exist regarding the optimal treatment between these procedures. Methods A systematic review of 3 databases (PubMed, Cochrane, and Embase) was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Inclusion criteria were English-language studies that compared clinical or functional outcomes after failed fixation of IT fractures with total hip arthroplasty and hemiarthroplasty in adult subjects (>18 years of age). Data regarding research design, surgical technique, and clinical or functional outcomes were obtained and analyzed from eligible studies using a Mantel-Haenszel random-effects analysis model. Results Six studies with 188 patients (100, total hip arthroplasty; 88, hemiarthroplasty) met inclusion and exclusion criteria. There was no significant difference between cTHA and cHA for postoperative dislocation, reoperation, infection, intraoperative fractures, postoperative fractures, or stem subsidence. The mean change in Harris Hip Scores was significantly higher (P Conclusions Despite potential advantages of cTHA or cHA for failed IT fractures, there were no differences in complications between either of the salvage procedures. Our analysis found a slight advantage in functional outcomes (Harris Hip Score) for cTHA at a minimum 14-month follow-up. Our study suggests that cTHA and cHA are both effective salvage procedures. Additional prospective studies are warranted to further delineate outcomes after salvage arthroplasty performed for failed IT fracture fixation.

Medicaid is associated with increased readmission and resource utilization after primary total knee arthroplasty: a propensity score–matched analysis

Abstract: Background Medicaid payer status has been shown to affect resource utilization across multiple medical specialties. There is no large database assessment of Medicaid and resource utilization in primary total knee arthroplasty (TKA), which this study sets out to achieve. Methods The Nationwide Readmissions Database was used to identify patients who underwent TKA in 2013 and corresponding "Medicaid" or "non-Medicaid" payer statuses. Demographics, 15 individual comorbidities, readmission rates, length of stay, and direct cost were evaluated. A propensity score–based matching model was then used to control for baseline confounding variables between payer groups. A chi-square test for paired proportions was used to compare readmission rates between the 2 groups. Length of stay and direct cost comparisons were evaluated using the Wilcoxon signed-rank test. Results A total of 8372 Medicaid and 268,261 non-Medicaid TKA patients were identified from the 2013 Nationwide Readmissions Database. A propensity score was estimated for each patient based on the baseline demographics, and 8372 non-Medicaid patients were propensity score matched to the 8372 Medicaid patients. Medicaid payer status yielded a statistically significant increase in overall readmission rates of 18.4% vs 14.0% (P Conclusions This study demonstrates that Medicaid payer status is independently associated with increased resource utilization, including readmission rates, length of stay, and total cost after TKA.

Femoral artery injury during total hip arthroplasty.

Abstract: There are an increasing number of vascular complications after hip replacement, some of which can be life-threatening. However, there are few reports of lower limb ischemic symptoms after undergoing an otherwise uncomplicated classic total hip replacement. We report a patient with low weight who developed postoperative limb ischemia resulting from blood clots caused by insertion of a Hohmann retractor close to small anterior acetabular osteophytes. Ultrasonography and angiography revealed her symptoms to be the result of femoral artery intimal injury with lower extremity arterial thrombosis, which led to pain, numbness, and decreased skin temperature. The patient underwent timely percutaneous intervention with a femoral artery stent, which relieved her symptoms. The discussion reviews femoral artery injury during total hip arthroplasty.

Pinnacle polyethylene liner dissociation: a report of 3 cases

Abstract: We describe 3 cases of DePuy Pinnacle polyethylene dissociations, their presentations, and treatment. A 34-year-old female with arthritis secondary to dysplasia, a 51-year-old male with avascular necrosis of the femoral head, and a 57-year-old female with osteoarthritis were treated with total hip arthroplasty. Acute nontraumatic polyethylene liner dissociations occurred at 31, 42, and 2 months postoperatively. They were treated with component retention and modular femoral head and liner revision. The 51-year-old male subsequently developed a prosthetic joint infection requiring explant of his components. Although dissociation of polyethylene liners from the DePuy Pinnacle acetabular components is an uncommon complication, this problem may increase in prevalence with longer term follow-up, and vigilance is recommended.

Radiographic assessment and clinical outcomes after total knee arthroplasty using an accelerometer-based portable navigation device.

Abstract: It has been reported that an accelerometer-based portable navigation device can achieve accurate bone cuts, but there have been few studies of clinical outcomes after total knee arthroplasty (TKA) using such a device. The aim of this study was to evaluate lower limb alignment and clinical outcomes after TKA using an accelerometer-based portable navigation device. Thirty-five patients (40 knees) underwent primary TKAs using an accelerometer-based portable navigation device. Postoperative radiographic assessments included the hip-knee-ankle angle, femoral component angle (FCA), and tibial component angle (TCA) in the coronal plane and the sagittal FCA and sagittal TCA in the sagittal plane. Clinical outcomes were evaluated by the Japanese Orthopedic Association score for osteoarthritic knees, Japanese Knee Osteoarthritis Measure, and the New Knee Society Score. The frequency of outliers (>3 degrees) was 10% for the hip-knee-ankle angle, 8% for FCA, 0% for TCA, 19% for sagittal FCA, and 9% for sagittal TCA. The Japanese Orthopedic Association score and Japanese Knee Osteoarthritis Measure were significantly improved postoperatively. The postoperative New Knee Society Score was 67.2% for symptoms, 50.3% for satisfaction, 58.6% for expectation, and 44.1% for function. TKA using an accelerometer-based portable navigation device achieved good results for both lower limb alignment and clinical outcomes.

Short-term safety and effectiveness of a second-generation motion-guided total knee system.

Abstract: Background Modern knee prostheses are designed to more closely replicate normal knee kinematics. The JOURNEY II Bi-Cruciate Stabilized Total Knee System (Smith & Nephew Inc., Memphis, TN) is a second-generation motion-guided knee system that demonstrates axial rotation patterns during flexion, which resemble those of the normal knee. The aim of this study was to assess the short-term safety and effectiveness of this system in standard clinical practice. Methods A total of 186 subjects (209 primary total knee arthroplasties [TKAs]) were enrolled at 12 U.S. sites. Subjects were operated on between December 2011 and October 2013 and followed for 24 months. Radiographic, clinical, and patient-reported outcome data were collected at 6-, 12-, and 24-month postoperatively. Results At 24-month follow-up, the average objective Knee Society Score was 96.20 (standard deviation [SD] = 6.63), the average satisfaction score was 35.22 (SD = 6.63), the average expectation score was 10.91 (SD = 3.16), and the average functional activities score was 81.49 (SD = 14.65). On a 0-10 scale, pain level for walking was 0.79 (SD = 1.51) and 1.50 (SD = 1.97) for climbing stairs or inclines. The cumulative incidence of reoperation at 2-year follow-up was 1.48% (95% confidence interval [CI] 0.48%-4.52%). Ten TKAs in 7 patients were treated with closed manipulations for stiffness. Iliotibial band syndrome was reported in 2 TKAs. Two deep infections occurred, 1 requiring reoperation. No dislocations occurred in the study cohort. Conclusions In short-term follow-up, the JOURNEY II Bi-Cruciate Stabilized Guided Motion Total Knee System appears to be a safe and effective device for TKA.

A risk-stratification algorithm to reduce superficial surgical site complications in primary hip and knee arthroplasty

Abstract: Background Surgical site complications (SSCs) are the most common cause for readmission after total joint arthroplasty (TJA), increasing costs while predisposing to inferior long-term outcomes. Prophylactic use of closed-incision negative pressure therapy (ciNPT) may lower the risk of these complications, especially in high-risk populations, but appropriate-use guidelines are lacking for patients undergoing primary TJA. We sought to develop a risk-stratification algorithm to guide use of ciNPT dressings and test its use in normalizing the rate of superficial SSCs among high-risk groups. Methods We reviewed 323 consecutive primary TJAs, where 38% of those patients considered at elevated risk were risk-stratified to receive ciNPT dressings. An individual risk score was developed, assigning points based on patient-specific risk factors. We identified a historical control population of 643 patients who all received the same postoperative dressing to test the impact of this risk score. Results Compared with historical controls, we observed a modest but significant improvement in superficial SSCs after implementation of risk-stratification (12.0% vs 6.8%; P = .013). Among high-risk patients, there was a marked improvement in SSCs when treated prophylactically with ciNPT dressings as compared with historical controls (26.2% vs 7.3%; P Conclusions ciNPT dressings are effective at reducing and normalizing risks of superficial SSCs among high-risk primary arthroplasty patients. The proposed risk-stratification algorithm may help identify those patients who benefit most from these dressings.

Superior rim fracture of a vitamin E-infused highly cross-linked polyethylene (HXLPE) liner leading to total hip arthroplasty revision.

Abstract: This case report looks at the failure of a vitamin E-infused highly cross-linked polyethylene acetabular liner that fractured at the superior rim of the locking mechanism. This calls to question whether there is a problem with the vitamin E-infused product or a flaw in the design of the liner or possibly a combination of the 2. Although there has been discussion of a possible minimum rim polyethylene thickness, there has not been a minimum thickness established. In addition, in the case of offset liners, indentations which are a part of a locking mechanism can cause the minimum rim dimension to be much less than the specified nominal thickness. This case serves as an interesting observation and contributes to the discussion of rim liner polyethylene thickness and minimum rim thickness.

Timed Up and Go test is predictive of Patient-Reported Outcomes Measurement Information System physical function in patients awaiting total knee arthroplasty.

Abstract: Background The Patient Reported Outcomes Measurement Information System (PROMIS) Computerized Adaptive Test (CAT) physical function rapidly assesses self-reported function capability. The Timed Up and Go (TUG) test is often used in clinical practice, but administration may be impeded by space and patient limitations. PROMIS CAT can potentially address these limitations, but we lack evidence if TUG and health indicators are predictors of PROMIS CAT. This study assessed whether TUG, body mass index (BMI), numeric pain rating scale (NPRS), and smoking status were predictors of PROMIS CAT in total knee arthroplasty (TKA) candidates. Methods Sixty-five TKA candidates completed the PROMIS CAT physical function test using an iPad application. TUG, NPRS, BMI, and smoking status were obtained at the clinic visit or from medical records. Univariate and multiple regression analyses identified the strongest predictors of PROMIS CAT. Results TUG was the best predictor of PROMIS CAT physical function based on simple regression (r = −0.43, 95% CI = −0.62 to −0.20) or multiple regression ( β ˆ = −0.45, 95% CI = −0.73 to −0.17) analyses. BMI and NPRS did not incrementally help predict the PROMIS score beyond TUG. Smoking status did not contribute to the prediction of the PROMIS CAT score. Conclusions The findings suggest that the PROMIS CAT physical function is not a surrogate for the TUG performance-based measure in candidates for TKA. However, TUG was the best predictor of PROMIS physical function compared with BMI, NPRS, and smoking status. Clinicians should consider both patient-reported and performance-based measures when evaluating function for TKA outcomes.

Femoral condylar necrosis: treatment with hyperbaric oxygen therapy

Abstract: Background Osteonecrosis of the knee (ONK) is a form of aseptic necrosis resulting from ischemia to subchondral bone tissue. Typically, treatment is invasive. Hyperbaric oxygen therapy (HBOT) may provide a noninvasive alternative by improving oxygenation and reperfusion of ischemic areas. This study evaluates the efficacy of HBOT in a series of ONK patients. Methods This retrospective study evaluates 37 ONK patients (29 male, 8 female; mean age ± 1 standard deviation: 54 ± 14); 83.7% of patients presented with Aglietti stage I-II; 16.3% presented with Aglietti stage III. Patients were treated with HBOT once a day, 5 days a week, at 2.5 atmosphere absolute with 100% inspired oxygen by mask for an average of 67.9 ± 15 sessions. Magnetic resonance imaging was performed before HBOT, within 1 year after completion of HBOT, and in 14 patients, 7 years after treatment. Oxford Knee Scores (OKSs) were recorded before HBOT and at the end of each HBOT treatment cycle. Results After the 30 sessions of HBOT, 86% of patients experienced improvement in their OKS, 11% worsened, and 3% did not change. All patients improved in OKS after 50 sessions. Magnetic resonance imaging evaluation 1 year after HBOT completion showed that edema at the femoral condyle had resolved in all but 1 patient. Conclusions HBOT is beneficial for treating ONK. Patients experienced improvements in pain and mobility as demonstrated by improvement in OKS. Radiographic improvements were also seen upon post-treatment follow-up. Aglietti staging for the entire sample saw an aggregate decrease (P

Small-colony variant of Staphylococcus lugdunensis in prosthetic joint infection.

Abstract: Prosthetic joint infection is usually caused by staphylococci. Among the coagulase-negative staphylococci, Staphylococcus lugdunensis is important because it behaves as a pathogen similar to S aureus. It also develops biofilms, and the biofilm phenotype can appear as small-colony variants. Although genetically indistinguishable, they differ in size and antibiotic susceptibility from the parent strain and are responsible for chronic persistent infection and failure of antibiotic treatment. They can also lead to misinterpretation of results. The patient reported here underwent total knee replacement and 2 years later presented with prosthetic joint infection. Tissue samples and prosthesis taken at revision grew S lugdunensis, the majority of which were small-colony variants. Recommendations are made for their detection and identification.

Abundant heterotopic bone formation following use of rhBMP-2 in the treatment of acetabular bone defects during revision hip arthroplasty.

Abstract: Revision hip arthroplasty in the setting of periacetabular bone loss presents a significant challenge, as options for restoring bone loss are limited. Recombinant human bone morphogenetic protein-2 may offer a solution by promoting bone growth to restore bone stock before implant reimplantation. Here we present a case of a patient with a periprosthetic acetabulum fracture, resulting in pelvic discontinuity as the result of significant periacetabular bone loss. Using a staged approach, periacetabular bone stock was nearly entirely reconstituted using recombinant BMPs and allograft, which resulted in stable fixation, but with abundant heterotopic bone formation. Recombinant BMP-2 offers a useful tool for restoring bone stock in complex hip arthroplasty revision cases with periacetabular bone loss; however, caution must be used as overabundant bone growth as heterotopic ossification may result.

Early femoral condyle insufficiency fractures after total knee arthroplasty: treatment with delayed surgery and femoral component revision

Abstract: Background Periprosthetic fracture following total knee arthroplasty (TKA) is usually associated with a traumatic event and typically treated with fracture fixation techniques. However, we report on a series of patients with early atraumatic condyle fractures that occurred as a result of insufficiency of the unloaded preoperative femoral condyle treated with delayed reconstruction. Methods We retrospectively reviewed a series of 7 patients who sustained femoral condyle fractures following TKA and evaluated risk factors for insufficiency. Results There were 6 females and 1 male with an average age of 65.5 (range, 63-75) years and an average body mass index of 29.4 (range, 27-32). Fracture occurred on average 24.9 days from the index surgery and secondary to a low energy mechanism. Five patients had valgus alignment (mean, 15.2°) preoperatively and sustained fracture of the unloaded medial femoral condyle. Two patients had varus alignment (mean, 7.0°) preoperatively and both fractured the unloaded lateral condyle. One patient underwent early intervention requiring distal femoral replacement secondary to femoral bone loss. The remaining 6 patients underwent delayed surgery for an average of 6 weeks to allow for fracture healing followed by femoral component revision. At last follow-up (average, 48.5 months), 1 patient required a tibial component revision; however, no revision of the femoral component was required. Conclusions Early femoral condyle insufficiency fractures following TKA may be a risk in females with poor bone quality and preoperative valgus alignment. Delayed surgery and femoral component revision is a treatment strategy that prevented the need for other tertiary reconstruction.

Rapid destructive osteoarthritis of the hip after intra-articular steroid injection

Abstract: Rapid destructive osteoarthritis of the hip is a separate entity different from the usual osteoarthritis. It is usually seen in elderly women, and the characteristic feature is the rapid progression within 6 to 12 months to complete destruction of the joint. The exact etiology is not known. We present a rare case of rapid destructive osteoarthritis of the hip in a 62-year-old woman who developed it within 2 months of intra-articular steroid injection, which was managed well with uncemented total hip arthroplasty. Through this report, we emphasize the possibility of the disastrous complication of injection, which should be informed to the patient before any intra-articular injection.

Do illness rating systems predict discharge location, length of stay, and cost after total hip arthroplasty?

Abstract: Background As procedure rates and expenditures for total hip arthroplasty (THA) rise, hospitals are developing models to predict discharge location, a major determinant of total cost. The predictive value of existing illness rating systems such as the American Society for Anesthesiologists (ASA) Physical Classification System, Severity of Illness (SOI) scoring system, or Mallampati (MP) rating scale on discharge location remains unclear. This study explored the predictive role of ASA, SOI, and MP scores on discharge location, lengths of stay, and total costs for THA patients. Methods A retrospective analysis of patients undergoing elective primary or revision THA was conducted at a single institution. Multivariable regressions were utilized to assess the significant predictive factors for lengths of stay, total costs, and discharge to skilled nursing facilities (SNFs), rehabilitation centers, and home. Controls included demographic factors, insurance coverage, and the type of procedure. Results ASA scores ≥3 are the only significant predictors of discharge to SNFs (odds ratio [OR] = 1.69, confidence interval [CI] = 1.04-2.74) and home (OR = 0.57, CI = 0.34-0.98). Medicaid coverage (OR = 2.61, CI = 1.37-4.96) and African-American race (OR = 2.60, CI = 1.59-4.25) were additional significant predictors of discharge to SNF. SOI scores are the only significant predictors of length of stay (β = 1.36 days, CI = 0.53-2.19) and total cost for an episode (β = $6,234, CI = $3577-$8891). MP scores possess limited predictive power over lengths of stay only. Conclusions These findings suggest that although ASA classifications predict discharge location and SOI scores predict length of stay and total costs, other factors beyond illness rating systems remain stronger predictors of discharge for THA patients.

Lyme periprosthetic joint infection in total knee arthroplasty.

Abstract: Lyme arthritis, caused by the spirochete Borrelia burgdorferi sensu stricto, is a common tick-borne illness in New England and the upper Midwest Most often, the disease affects the knee and has typically been reported as a cause of native joint infection There has been only 1 case of Lyme periprosthetic joint infection (associated with a total knee arthroplasty) reported in the literature, and to our knowledge, no other reported cases of Lyme periprosthetic joint infections exist In this article, we report on 2 patients diagnosed with prosthetic joint infections who were subsequently found to have Lyme prosthetic joint infections, with B burgdorferi as the infectious organism We discuss the medical and surgical management of these patients

Tibial tray fracture in a modern prosthesis with retrieval analysis.

Abstract: Fracture of the tibial tray is a rarely observed complication of total knee arthroplasty (TKA), predominately in implants placed greater than a decade ago. This case highlights a case of baseplate fracture in a contemporary prosthesis. The patient presented 1 year after TKA with medial knee pain consistent with pes bursitis. The implant-cement-bone construct was intact and she was managed with corticosteroids. She had persistent pain, acutely developed new varus deformity, and presented with a tibial tray fracture. Retrieval analysis suggested fatigue fracture as the likely mechanism. At time of revision, necrotic bone was found at the medial plateau, which likely caused cantilever bending relative to the well-supported portion of the tray and resultant failure. The patient continues to do well 5 years after revision TKA.

Confounding pain and function: the WOMAC's failure to accurately predict lower extremity function

Abstract: Background Investigations have revealed the Western Ontario and McMaster Universities Osteoarthritis Index’s (WOMAC) inability to provide distinct assessments of pain and function. The Lower Extremity Functional Scale (LEFS) has not displayed this deficiency. Our purposes were to investigate further the WOMAC physical function's (WOMAC-PF) ability to accurately assess lower extremity mobility in patients undergoing total knee arthroplasty (TKA) and to establish a relationship between pre- and post-TKA WOMAC-PF and LEFS scores that accounts for the apparent bias WOMAC pain scores impose on WOMAC-PF scores. Methods WOMAC, LEFS, and Timed-up-and-go measures were administered before TKA and 4 days, 6 weeks, and 3 months after TKA. To evaluate the WOMAC-PF and LEFS ability to provide a distinct assessment of pain and function, a paired t-test compared pre-TKA and 4 days after TKA values. Generalized estimating equation (GEE) analysis assessed the relationship between pre- and post-TKA values: dependent variable WOMAC-PF scores; independent variables LEFS scores, and measurement occasions. Results Timed-up-and-go and LEFS demonstrated a reduction in lower extremity function (P Conclusions Our findings support previous investigations that showed the WOMAC-PF’s inability to provide a valid assessment in change in function. The GEE analysis coefficients can be used to convert LEFS scores to WOMAC-PF scores that adjust for the bias between pre- and post-TKA assessments.