Metallosis in Total Hip Arthroplasty.

¼ Metallosis is a rare but significant complication that can occur after total hip arthroplasty (THA) for a variety of reasons but most commonly in patients with metal-on-metal implants.¼ It is characterized by the visible staining, necrosis, and fibrosis of the periprosthetic soft tissues, along with the variable presence of aseptic cysts and solid soft tissue masses called pseudotumors secondary to the corrosion and deposition of metal debris.¼ Metallosis can present with a spectrum of complications ranging from pain and inflammation to more severe symptoms such as osteolysis, soft tissue damage, and pseudotumor formation.¼ Workup of metallosis includes a clinical evaluation of the patient's symptoms, imaging studies, serum metal-ion levels, and intraoperative visualization of the staining of tissues. Inflammatory markers such as erythrocyte sedimentation rate and C-reactive protein along with intraoperative frozen slice analysis may be useful in certain cases to rule out concurrent periprosthetic joint infection.¼ Management depends on the severity and extent of the condition; however, revision THA is often required to prevent rapid progression of bone loss and tissue necrosis.

Serum CD64 as a Marker for Chronic Periprosthetic Joint Infection.

Background: Serum cluster of differentiation 64 (CD64) has emerged as a diagnostic test for musculoskeletal infections. The purpose of this study was to evaluate the utility of serum CD64 in diagnosing periprosthetic joint infections (PJIs) compared to conventional markers like white blood count (WBC), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and interleukin-6 (IL-6). Methods: A prospective case-control study on patients undergoing revision hip or knee arthroplasty surgery >6 weeks after their index surgery was performed at a single institution. Whole blood samples were drawn within 24 hours prior to revision surgery for white blood count, ESR, CRP, IL-6, and CD64. Intraoperative cultures were obtained during the revision, and PJI was defined using the major criteria from the 2018 Musculoskeletal Infection Society criteria. Two-sample Wilcoxon rank-sum test and Fisher's exact test were used to determine if there were significant differences in serum laboratory values between patients with and without infection. The sensitivity, specificity, positive predictive value (PPV), negative predictive value, and accuracy of each test were calculated. Results: With an average age of 67 years, 39 patients with 15 revision THAs and 24 TKAs, were included. 19 patients (48.7%) were determined to have PJI. Patients with PJI had significantly higher CD64 (P = .036), CRP (P = .016), and ESR (P = .045). CD64 had the highest specificity (100%) and PPV (100%), moderate accuracy (69.2%), but low sensitivity (37.0%) and negative predictive value (62.5%). Conclusions: Given the high specificity, PPV, and accuracy, CD64 may be an excellent confirmatory test to help diagnose PJI.

Revision total knee arthroplasty for arthrofibrosis improves range of motion.

PURPOSE: Arthrofibrosis after primary total knee arthroplasty (TKA) is a significant contributor to patient dissatisfaction. While treatment algorithms involve early physical therapy and manipulation under anaesthesia (MUA), some patients ultimately require revision TKA. It is unclear whether revision TKA can consistently improve these patient's range of motion (ROM). The purpose of this study was to evaluate ROM when revision TKA was performed for arthrofibrosis. METHODS: A retrospective study of 42 TKA's diagnosed with arthrofibrosis from 2013 to 2019 at a single institution with a minimum 2-year follow-up was performed. The primary outcome was ROM (flexion, extension, and total arc of motion) before and after revision TKA, and secondary outcomes included patient reported outcomes information system (PROMIS) scores. Categorical data were compared using chi-squared analysis, and paired samples t tests were performed to compare ROM at three different times: pre-primary TKA, pre-revision TKA, and post-revision TKA. A multivariable linear regression analysis was performed to assess for effect modification on total ROM. RESULTS: The patient's pre-revision mean flexion was 85.6 degrees, and mean extension was 10.1 degrees. At the time of the revision, the mean age of the cohort was 64.7 years, the average body mass index (BMI) was 29.8, and 62% were female. At a mean follow-up of 4.5 years, revision TKA significantly improved terminal flexion by 18.4 degrees (p < 0.001), terminal extension by 6.8 degrees (p = 0.007), and total arc of motion by 25.2 degrees (p < 0.001). The final ROM after revision TKA was not significantly different from the patient's pre-primary TKA ROM (p = 0.759). PROMIS physical function, depression, and pain interference scores were 39 (SD = 7.72), 49 (SD = 8.39), and 62 (SD = 7.25), respectively. CONCLUSION: Revision TKA for arthrofibrosis significantly improved ROM at a mean follow-up of 4.5 years with over 25 degrees of improvement in the total arc of motion, resulting in final ROM similar to pre-primary TKA ROM. PROMIS physical function and pain scores showed moderate dysfunction, while depression scores were within normal limits. While physical therapy and MUA remain the gold standard for the early treatment of stiffness after TKA, revision TKA can improve ROM. LEVEL OF EVIDENCE: IV.

Impact of Antibiotic-Impregnated Spacer Design in the Treatment of Periprosthetic Hip Infection.

Background: Although 2-stage exchange arthroplasty, consisting of temporary insertion of an antibiotic-impregnated cement spacer (AICS), is considered the standard of care for chronic periprosthetic joint infection (PJI) in total hip arthroplasty (THA), a consensus on the AICS design has not yet been established. Ceramic-on-polyethylene AICSs (Poly-AICS) are theorized to cause less pain and better function than cement-on-bone AICS (CemB-AICS) but use non-antibiotic-impregnated components that may harbor bacteria. This study evaluates the impact of spacer design on infection-free survivorship following THA reimplantation as well as pain and function during the interim AICS stage. Methods: A retrospective review was performed of all cases of THA PJI treated with either Poly-AICS or CemB-AICS at a single high-volume academic center. Data were collected until the final follow-up after THA reimplantation with an average follow-up duration of 2.6 years. The primary outcome was infection-free survivorship after the final reimplantation. Secondary outcomes included postoperative pain scores, opioid use, time to ambulation, length of stay, complications, and discharge disposition. Results: A total of 99 cases (67 CemB-AICS; 32 Poly-AICS) were included. There were no baseline differences between the 2 groups. There were no differences in infection-free survivorship after reimplantation in survivorship curve comparisons (P = .122) and no differences in postoperative inpatient pain scores, opioid use, length of stay, time to ambulation, complications, or discharge disposition during the AICS stage. Conclusions: Patients with THA PJI treated with Poly-AICS did not have worse infection-related outcomes despite the use of non-antibiotic-impregnated components but also did not appear to have less pain or improved function during the early AICS stage.

Increased Prevalence, Complications, and Costs of Smokers Undergoing Total Knee Arthroplasty.

Given a national push toward bundled payment models, the purpose of this study was to examine the prevalence as well as the effect of smoking on early inpatient complications and cost following elective total knee arthroplasty (TKA) in the United States across multiple years. Using the nationwide inpatient sample, all primary elective TKA admissions were identified from 2012 to 2014. Patients were stratified by smoking status through a secondary diagnosis of "tobacco use disorder." Patient characteristics as well as prevalence, costs, and incidence of complications were compared. There was a significant increase in the rate of smoking in TKA from 17.9% in 2012 to 19.2% in 2014 (p < 0.0001). The highest rate was seen in patients < 45 years of age (27.3%). Hospital resource usage was significantly higher for smokers, with a length of stay of 3.3 versus 2.9 days (p < 0.0001), and hospital costs of $16,752 versus $15,653 (p < 0.0001). A multivariable logistic model adjusting for age, gender, and comorbidities showed that smokers had an increased odds ratio for myocardial infarction (5.72), cardiac arrest (4.59), stroke (4.42), inpatient mortality (4.21), pneumonia (4.01), acute renal failure (2.95), deep vein thrombosis (2.74), urinary tract infection (2.43), transfusion (1.38) and sepsis (0.65) (all p < 0.0001). Smoking is common among patients undergoing elective TKA, and its prevalence continues to rise. Smoking is associated with higher hospital costs as well as higher rates of immediate inpatient complications. These findings are critical for risk stratification, improving of bundled payment models as well as patient education, and optimization prior to surgery to reduce costs and complications.

How Are Orthopaedic Surgery Residencies Responding to the COVID-19 Pandemic? An Assessment of Resident Experiences in Cities of Major Virus Outbreak.

BACKGROUND: In response to COVID-19, American medical centers have enacted elective case restrictions, markedly affecting the training of orthopaedic residents. Residencies must develop new strategies to provide patient care while ensuring the health and continued education of trainees. We aimed to describe the evolving impact of COVID-19 on orthopaedic surgery residents. METHODS: We surveyed five Accreditation Council for Graduate Medical Education-accredited orthopaedic residency programs within cities highly affected by the COVID-19 pandemic about clinical and curricular changes. An online questionnaire surveyed individual resident experiences related to COVID-19. RESULTS: One hundred twenty-one resident survey responses were collected. Sixty-five percent of the respondents have cared for a COVID-19-positive patient. One in three reported being unable to obtain institutionally recommended personal protective equipment during routine clinical work. All programs have discontinued elective orthopaedic cases and restructured resident rotations. Most have shifted schedules to periods of active clinical duty followed by periods of remote work and self-isolation. Didactic education has continued via videoconferencing. DISCUSSION: COVID-19 has caused unprecedented changes to orthopaedic training; however, residents remain on the front lines of inpatient care. Exposures to COVID-19 are prevalent and residents have fallen ill. Programs currently use a variety of strategies to provide essential orthopaedic care. We recommend continued prioritization of resident safety and necessary training accommodations.

Smoking and Total Hip Arthroplasty: Increased Inpatient Complications, Costs, and Length of Stay.

BACKGROUND: Smoking is a potentially modifiable risk factor that may impact the overall outcomes of total hip arthroplasty (THA). In an era of bundled payments for THA, the purpose of this study was to evaluate, on a national level, the inpatient complications and additional costs of smokers undergoing THA. METHODS: The Nationwide Inpatient Sample was used to identify all primary elective THAs performed in the United States in 2014. This cohort was further stratified by smoking status. Inpatient hospital characteristics, costs, and complications rates were assessed. RESULTS: The Nationwide Inpatient Sample had 63,446 admissions recorded for primary THAs in 2014, corresponding to an estimated 317,230 cases nationwide. The smoking rate was 20.7%. Smokers were slightly yet significantly younger than nonsmokers (63.5 years vs 64.8 years; P < .0001). The smoking group had a significantly longer hospital stay and higher total hospital costs (both P < .0001). After using a multivariable logistic model adjusting for age, gender, and comorbidities, smokers were found to have a significantly higher odds ratio (OR [95% confidence interval {CI}]) for myocardial infarction (15.5 [5.0-47.5]), cardiac arrest (10.1 [2.2-47.6]), pneumonia (4.7 [2.4-9.1]), urinary tract infection (1.9 [1.4-2.7]), sepsis (13.1 [3.5-49.0]), acute renal failure (2.9 [2.2-3.7]), discharge to a skilled nursing facility (1.3 [1.2-1.4]), and mortality (11.7 [2.0-70.5]). CONCLUSIONS: Smoking remains a highly prevalent and important risk factor for complications in elective primary THA in the United States. Patients who smoke have a significantly higher rate of complications and generate significantly higher postoperative inpatient costs. These findings are important for risk stratification, bundled payment considerations, as well as perioperative patient education and intervention.

Increasing Burden of Total Hip Arthroplasty Revisions in Patients Between 45 and 64 Years of Age.

BACKGROUND: This study provides a comprehensive analysis of total hip arthroplasty (THA) revisions in the U.S. from 2007 to 2013. METHODS: International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes were used to identify all THA revisions in the Nationwide Inpatient Sample (NIS) from 2007 to 2013. The diagnoses leading to the revisions, types of revisions, major inpatient complications, and hospital and patient characteristics were compared between 2007 and 2013. Multivariable logistic regression models were used to calculate adjusted odds ratios (ORs) for complications in 2013 versus 2007. RESULTS: This study identified 320,496 THA revisions performed between 2007 and 2013. From 2007 to 2013, the THA revision rate adjusted for U.S. population growth increased by 30.4% in patients between 45 and 64 years of age and decreased in all other age groups. The rate of surgically treated THA dislocations decreased by 14.3% from 2007 to 2013 (p < 0.0001). The mean length of the hospital stay and hospital costs for THA revision were significantly lower in 2013 than in 2007 (4.6 versus 5.8 days and $20,463 versus $25,401 both p < 0.0001). A multivariable model showed that the odds of a patient undergoing THA revision having the following inpatient complications were significantly lower in 2013 than in 2007: deep vein thrombosis (OR = 0.57, p = 0.004), pulmonary embolism (OR = 0.45, p = 0.047), myocardial infarction (OR = 0.52, p = 0.003), transfusion (OR = 0.64, p < 0.0001), pneumonia (OR = 0.56, p < 0.0001), urinary tract infection (OR = 0.66, p < 0.0001), and mortality (OR = 0.50, p = 0.0009). Notably, the odds of being discharged to a skilled nursing facility were also lower in 2013 than in 2007 (OR = 0.71, p < 0.0001). CONCLUSIONS: The THA revision rate has significantly increased in patients between 45 and 64 years of age. However, the rate of surgically treated THA dislocations has decreased significantly. This may indicate that evolving techniques and implants are improving stability. The rate of inpatient complications following THA revision also decreased significantly from 2007 to 2013. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Inflammatory pseudotumor after ceramic-on-ceramic total hip arthroplasty.

We present a unique case of a symptomatic adverse local tissue reaction in a patient with a ceramic-on-ceramic total hip bearing surface. To our knowledge, this pathological finding has not yet been described in a ceramic-on-ceramic articulation without a cobalt-chromium alloy trunnion or modular neck component as a source of metal wear. We conclude that despite its mechanical mostly benign wear characteristics, ceramic wear debris is not entirely inert and may lead to the development of adverse local tissue reaction.

Surgical treatment of three and four-part proximal humeral fractures.

BACKGROUND: Optimal surgical management of three and four-part proximal humeral fractures in osteoporotic patients is controversial, with many advocating prosthetic replacement of the humeral head. Fixed-angle locked plates that maintain angular stability under load have been proposed as an alternative to hemiarthroplasty for the treatment of some osteoporotic fracture types. METHODS: The records of 122 consecutive patients who were fifty-five years of age or older and in whom a Neer three or four-part proximal humeral fracture had been treated surgically between January 2002 and November 2005 were studied retrospectively. After exclusions, thirty-eight patients treated with a locked-plate construct were compared with forty-eight patients who had undergone hemiarthroplasty. All patients had radiographic and clinical follow-up at a minimum of twenty-four months and an average of thirty-six months. Reduction and implant placement were evaluated radiographically. Clinical outcomes were measured with use of the Constant-Murley system. RESULTS: The mean Constant score (and standard deviation) at the time of final follow-up was significantly better in the locked-plate group (68.6 +/- 9.5 points) than in the hemiarthroplasty group (60.6 +/- 5.9 points) (p < 0.001). The Constant scores for the three-part fractures in the locked-plate and hemiarthroplasty groups were 71.6 and 60.4 points (p < 0.001), respectively, and the scores for the four-part fractures in those groups were 64.7 and 60.1 points (p = 0.19), respectively. Patients with an initial varus extension deformity in the locked-plate group had significantly worse outcomes than those with a valgus impacted pattern (Constant score, 63.8 compared with 74.6 points, respectively; p < 0.001). Complications in the group treated with locked-plate fixation included osteonecrosis in six patients, screw perforation of the humeral head in six patients, loss of fixation in four patients, and wound infection in three patients. Loss of fixation was seen only in patients with >20 degrees of initial varus angulation of the humeral head. Complications in the hemiarthroplasty group included nonunion of the tuberosity in seven patients and wound infection in three patients. CONCLUSIONS: In this series, open repair with use of a locked plate resulted in better outcome scores than did hemiarthroplasty in similar patients, especially in those with a three-part fracture, despite a higher overall complication rate. Open reduction and internal fixation of fractures with an initial varus extension pattern should be approached with caution.

Locked plating of 3- and 4-part proximal humerus fractures in older patients: the effect of initial fracture pattern on outcome.

OBJECTIVES: The use of locked plates in repairing osteopenic 3- and 4-part proximal humerus fractures remains controversial. The purpose of this article was to report the outcomes of open reduction and internal fixation in low-energy proximal humerus fractures treated with locked plating in patients older than 55 years and stratify risk of failure or complication based on initial radiographic features. DESIGN: Retrospective. SETTING: Level I Trauma Center. METHODS: Seventy patients older than 55 years undergoing locked plate fixation for Neer 3- or 4-part proximal humerus fractures were studied retrospectively. All patients had standardized, true size digital radiographs of the injured and normal shoulder in the axillary, scapular Y, and 20-degree external rotation views with a minimum of 18 months' clinical follow-up. Two groups were identified based on the initial direction of the humeral head deformity: varus or valgus impaction. There were no statistical differences between treatment groups with regard to age, sex, Neer classification, follow-up, or dislocation. Radiographic measurements included humeral head angulation, tuberosity displacement, and length of the intact metaphyseal segment. Clinical outcomes measured Constant scores (CS) using active range of motion at latest follow-up. RESULTS: Twenty-four patients with initial varus fracture patterns healed with an average of 16-degree varus head angulation and an overall CS of 63 at an average of 34 months' follow-up. Forty-six patients with initial valgus fracture patterns healed with an average of 6 degrees of varus angulation and an overall CS of 71 at an average of 37 months' follow-up (P < 0.01). Complications of avascular necrosis, humeral head perforation, loss of fixation, tuberosity displacement >5 mm, and varus subsidence >5 degrees were encountered in 19 of 24 (79%) in the varus group compared with 9 of 46 (19%) in the valgus group (P < 0.01). Final CSs for 3-part fractures were 65 versus 72 (P < 0.01) for varus and valgus groups, respectively, and 61 versus 69 (P = 0.19) for 4-part fractures. CONCLUSIONS: Neer 3- and 4-part proximal humeral fractures in older patients with initial varus angulation of the humeral head had a significantly worse clinical outcome and higher complication rate than similar fracture patterns with initial valgus angulation. Two factors had significant influence on final outcome in these fracture patterns: initial direction of the humeral head angulation and length of the intact metaphyseal segment attached to the articular fragment. The best clinical outcomes were obtained in valgus impacted fractures with a metaphyseal segment length of greater than 2 mm, and this was independent of Neer fracture type. Humeral head angulation had the greatest effect on final outcomes (P < 0.001), whereas metaphyseal segment length of less than 2 mm was predictive of developing avascular necrosis (P < 0.001).

Venous thromboembolic disease after total hip and knee arthroplasty: current perspectives in a regulated environment.

Venous thromboembolic disease is the single most common reason for readmission to the hospital following total hip and total knee arthroplasty and remains a genuine threat to the life of the patient. Nevertheless, advances in surgical procedure, anesthetic management, and postoperative convalescence have altered the risks of venous thromboembolism after total joint arthroplasty in the lower extremity. Regional anesthetic techniques reduce the prevalence of venographic thrombosis by approximately 50%, and intraoperative monitoring has identified preparation of the femoral canal as the sentinel event that activates the coagulation cascade by the intravasation of marrow fat into the systemic circulation. Prevention of venographic thrombosis is most efficacious by administering fractionated heparin followed by warfarin; warfarin (international normalized ratio 2.0) appears to have a greater safety margin than fractionated heparin based on clinically meaningful bleeding events. Prevention of readmission events, proximal thrombosis, or pulmonary embolism has been demonstrated by using low-intensity warfarin. Aspirin, when used in conjunction with hypotensive epidural anesthesia after hip arthroplasty and regional anesthesia after knee arthroplasty, combined with pneumatic compression devices, also has been suggested to prevent clinical venous thromboembolism, as measured by readmission events. Oral thrombin inhibitors hold promise, but instances of liver toxicity have precluded approval in North America to date. Mechanical compression devices enhance venous flow and increase fibrinolytic activity in the lower extremity; clinical trials demonstrate efficacy in reducing venographic thrombosis alone after total knee arthroplasty and in combination with other chemoprophylactic agents after total hip arthroplasty. Extended chemoprophylaxis for 3 to 6 weeks after surgery is prudent in view of the protracted risk of thrombogenesis and the late occurrence of readmission for venous thrombosis and pulmonary embolism.

Musculoskeletal manifestations of human immunodeficiency virus infection.

Musculoskeletal manifestations of the human immunodeficiency virus (HIV) are common and are sometimes the initial presentation of the disease. Knowledge of the conditions affecting muscle, bone, and joints in HIV-infected patients is essential for successful management. Myopathies may be caused by pyogenic infection (eg, pyomyositis), idiopathic inflammation (eg, polymyositis), or drug effect (eg, AZT myopathy). Characteristic skeletal infections, such as tuberculosis and bacillary angiomatosis, require a high index of suspicion for accurate diagnosis. Neoplastic processes, such as non-Hodgkin's lymphoma and Kaposi's sarcoma, occur more frequently as the immune system deteriorates. Inflammatory and reactive arthropathies are more prevalent in HIV-positive than HIV-negative individuals and include Reiter's syndrome, psoriatic arthritis, HIV-associated arthritis, painful articular syndrome, acute symmetric polyarthritis, and hypertrophic osteoarthropathy. Patients with atypical musculoskeletal complaints and a suspected history of exposure should be tested for HIV.

Association between human immunodeficiency virus and osteonecrosis of the femoral head.

The records of a consecutive series of 50 patients treated operatively for osteonecrosis of the femoral head were reviewed to determine the prevalence of human immunodeficiency virus (HIV) as an isolated risk factor for osteonecrosis. Twelve patients had a history of trauma to the hip and were excluded from the study. The remaining 38 patients were treated operatively for nontraumatic osteonecrosis of the femoral head. Of these, 7 patients were HIV positive, and 31 were HIV negative. Of the 7 patients who were HIV positive, 4 (57%) had none of the known risk factors for osteonecrosis. Of the 31 patients who were HIV negative, 4 (13%) had none of the known risk factors for osteonecrosis. The difference between the groups was statistically significant, suggesting that HIV infection is a risk factor for the development of osteonecrosis of the femoral head.