Primary total knee arthroplasty in patients with post-polio syndrome.

Aims: Knowledge on total knee arthroplasties (TKAs) in patients with a history of poliomyelitis is limited. This study compared implant survivorship and clinical outcomes among affected and unaffected limbs in patients with sequelae of poliomyelitis undergoing TKAs. Methods: A retrospective review of our total joint registry identified 94 patients with post-polio syndrome undergoing 116 primary TKAs between January 2000 and December 2019. The mean age was 70 years (33 to 86) with 56% males (n = 65) and a mean BMI of 31 kg/m2 (18 to 49). Rotating hinge TKAs were used in 14 of 63 affected limbs (22%), but not in any of the 53 unaffected limbs. Kaplan-Meier survivorship analyses were completed. The mean follow-up was eight years (2 to 19). Results: The ten-year survivorship free from revision was 91% (95% confidence interval (CI) 81 to 100) in affected and 84% (95% CI 68 to 100) in unaffected limbs. There were six revisions in affected limbs: three for periprosthetic femoral fractures and one each for periprosthetic joint infection (PJI), patellar clunk syndrome, and instability. Unaffected limbs were revised in four cases: two for instability and one each for PJI and tibial component loosening. The ten-year survivorship free from any reoperation was 86% (95% CI 75 to 97) and 80% (95% CI 64 to 99) in affected and unaffected limbs, respectively. There were three additional reoperations among affected and two in unaffected limbs. There were 12 nonoperative complications, including four periprosthetic fractures. Arthrofibrosis occurred in five affected (8%) and two unaffected limbs (4%). Postoperative range of motion decreased with 31% achieving less than 90° knee flexion by five years. Conclusion: TKAs in post-polio patients are complex cases associated with instability, and one in four require constraint on the affected side. Periprosthetic fracture was the main mode of failure. Arthrofibrosis rates were high and twice as frequent in affected limbs.

Retained Functional Antibiotic Hip Spacers Have High Rates of Stem Loosening, Subsidence, and Reoperation.

BACKGROUND: Functional antibiotic hip spacers for treatment of periprosthetic joint infection may be retained in patients deemed too sick for reimplantation, or who elect to forego additional surgery. Our aim was to characterize reoperations, modes of failure, and function outcomes in patients who have retained hip spacers. METHODS: We performed a retrospective review of 43 hips that underwent placement of an articulating hip spacer between January 1, 2014 and November 30, 2021. There were 28 hips that completed 2-stage exchange (TS group) and were reimplanted at mean 4 months (range, 2 to 10). The other 15 hips underwent planned spacer retention (RS group). Mean follow-up was 2.9 years (range, 1 to 6.1 years). The RS group was older (74 versus 66 years, P = .005) and had a higher age-adjusted Charlson Comorbidity Index (4.4 versus 3.3, P = .04) compared with the TS group. RESULTS: Overall survivorship free of reinfection was 91% at 1 year and 86% at 5 years. There were 6 RS hips that underwent reimplantation for spacer failure at a mean of 23 months (range, 6 to 71 months) and 8 had radiographic stem loosening/subsidence. Patients who had a retained spacer at final follow-up were more likely to require a walker (P = .005) or wheelchair (P = .049) compared with patients who underwent reimplantation. CONCLUSIONS: Retained hip spacers can decrease overall surgical burden, but are associated with high rates of stem loosening, subsidence, and unplanned reoperation. Planned spacer retention should be undertaken with caution in patients healthy enough to undergo reimplantation.

Liner malseating is rare with two modular dual-mobility designs.

AIMS: The aim of this study was to evaluate the incidence of liner malseating in two commonly used dual-mobility (DM) designs. Secondary aims included determining the risk of dislocation, survival, and clinical outcomes. METHODS: We retrospectively identified 256 primary total hip arthroplasties (THAs) that included a DM component (144 Stryker MDM and 112 Zimmer-Biomet G7) in 233 patients, performed between January 2012 and December 2019. Postoperative radiographs were reviewed independently for malseating of the liner by five reviewers. The mean age of the patients at the time of THA was 66 years (18 to 93), 166 (65%) were female, and the mean BMI was 30 kg/m2 (17 to 57). The mean follow-up was 3.5 years (2.0 to 9.2). RESULTS: Three liners (1.2%) were malseated, including two MDMs (1.4%) and one G7 (0.9%). No clinical consequence was identified from malseating. The five-year survival free of dislocation was 97.1%, including two DM and one intraprosthetic dislocation. The five-year survival free of revision was 95.4%, with seven revisions. The mean Harris Hip Scores increased from 46 (24 to 69) preoperatively to 81 (40 to 100) at two years postoperatively (p < 0.001). CONCLUSION: The incidence of DM liner malseating after primary THA was low, with no known clinical consequences at mid-term follow-up. Malseating is not exclusive of design, and these findings emphasize the importance of careful evaluation of the liner after impaction to avoid this complication. Cite this article: Bone Joint J 2022;104-B(5):598-603.

Factors Associated With Early Return to Driving Following Total Joint Arthroplasty.

BACKGROUND: Patients often ask when they can safely return to driving a car following total joint arthroplasty (TJA). Most prior research has relied on driving simulators. Our study sought to learn more about real-world patient experiences in returning to driving after total knee arthroplasty (TKA) or total hip arthroplasty (THA). METHODS: Our institutional total joint registry was used to identify living patients aged 18-85 who underwent primary TKA or primary THA for a primary diagnosis of osteoarthritis between January 1, 2019 and December 31, 2019. Patients who had undergone multiple TJA operations in 2019 or had a primary mailing address outside of the United States were excluded. Ultimately 2508 eligible TJA patients received a survey by mail. RESULTS: A total of 1128 of 2508 eligible patients (45%) completed surveys and returned them by mail. After 121 surveys were discarded for incompletion, inconsistency, or limited preoperative driving volume, 1007 patients were included in our study. Among these patients, 99% returned to driving postoperatively, with 23% returning within 2 weeks, and 88% returning within 6 weeks. Factors associated with the odds of a patient returning to driving within 2 weeks included laterality, gender, postoperative confidence, postoperative comfort, and surgeon advice. Ten patients (1%) have been involved in a car accident postoperatively. CONCLUSION: Almost all patients returned to driving postoperatively without being involved in a car accident. Gender, laterality, patient confidence, and comfort as well as surgeon advice were significantly associated with the odds of a patient returning to driving within 2 weeks postoperatively.

Assessing Taper Geometry, Head Size, Head Material, and Their Interactions in Taper Fretting Corrosion of Retrieved Total Hip Arthroplasty Implants.

BACKGROUND: Decreased fretting and corrosion damage at the taper interface of retrieved ceramic-on-polyethylene total hip arthroplasty (THA) implants has been consistently reported; however, resultant fretting corrosion as a function of femoral head size and taper geometry has not been definitively explained. METHODS: Eight cohorts were defined from 157 retrieved THA implants based on femoral head composition (n = 95, zirconia-toughened alumina, ZTA vs n = 62, cobalt-chromium alloy, CoCr), head size (n = 56, 32mm vs n = 101, 36mm), and taper geometry (n = 84, 12/14 vs n = 73, V40). THA implants were evaluated and graded for taper fretting and corrosion. Data were statistically analyzed, including via a 23 factorial modeling. RESULTS: Factorial-based analysis indicated the significant factors related to both resultant (summed) fretting and corrosion damage were head material and taper geometry; head material-taper geometry interaction was also a significant factor in resultant corrosion damage. Lower rates of moderate-to-severe fretting and corrosion damage were exhibited on ZTA heads (ZTA = 13%, CoCr = 38%), smaller heads (32mm = 18%, 36mm = 26%), and 12/14 tapers (12/14 = 13%, V40 = 35%). ZTA+32mm heads demonstrated the lowest rates of moderate-to-severe fretting and corrosion damage (12/14 = 2%, V40 = 7%), whereas CoCr heads with V40 tapers demonstrated the greatest rates of moderate-to-severe damage (32mm = 47%, 36mm = 59%). CONCLUSION: In this series, retrieved implants with ZTA, 32-mm heads paired with 12/14 tapers exhibited lower rates of moderate-to-severe damage. Factorial analysis showed head material, taper geometry, and their interactions were the most significant factors associated with resultant damage grades. Isolating implant features may provide additional information regarding factors leading to fretting and corrosion damage in THA. LEVEL OF EVIDENCE: IV (case series).

Low-Dose vs Regular-Dose Aspirin for Venous Thromboembolism Prophylaxis in Primary Total Joint Arthroplasty.

BACKGROUND: Consensus on whether low-dose (81 mg) or regular-dose (325 mg) aspirin (ASA) is more effective for venous thromboembolism (VTE) chemoprophylaxis in primary total joint arthroplasties (TJAs) is not reached. The goal of this study is to evaluate the efficacy of low-dose and regular-dose ASA for VTE chemoprophylaxis in primary total hip arthroplasties and total knee arthroplasties. METHODS: We retrospectively identified 3512 primary TJAs (2344 total hip arthroplasties and 1168 total knee arthroplasties) with ASA used as VTE chemoprophylaxis between 2000 and 2019. Patients received ASA twice daily for 4-6 weeks after surgery with 961 (27%) receiving low-dose ASA and 2551 (73%) receiving regular-dose ASA. The primary endpoint was 90-day incidence of symptomatic VTEs. Secondary outcomes were gastrointestinal (GI) bleeding events and mortality. The mean age at index TJA was 66 years, 54% were female, and mean body mass index was 31 kg/m2. The mean Charlson Comorbidity Index was 3.5. Mean follow-up was 3 years. RESULTS: There was no difference in 90-day incidence of symptomatic VTEs between low-dose and regular-dose ASA (0% vs 0.1%, respectively; P = .79). There were no GI bleeding events in either group. There was no difference in 90-day mortality between low-dose and regular-dose ASA (0.3% vs 0.1%, respectively; P = .24). CONCLUSION: In 3512 primary TJA patients treated with ASA, we found a cumulative incidence of VTE <1% at 90 days. Although this study is underpowered, it appears that twice daily low-dose ASA was equally effective to twice daily regular-dose ASA for VTE chemoprophylaxis, with no difference in risk of GI bleeds or mortality. LEVEL OF EVIDENCE: III, retrospective cohort study.

Total Hip Arthroplasty in Patients With Osteopetrosis.

BACKGROUND: Osteopetrosis is an inherited bone disease associated with high risk of osteoarthritis and fracture non-union, which can lead to total hip arthroplasty (THA). Bone quality and morphology are altered in these patients, and there are limited data on results of THA in these patients. The goals of this study were to describe implant survivorship, clinical outcomes, radiographic results, and complications in patients with osteopetrosis undergoing primary THA. METHODS: We identified 7 patients (9 hips) with osteopetrosis who underwent primary THA between 1970 and 2017 utilizing our total joint registry. The mean age at index THA was 48 years and included two males and five females. The mean follow-up was 8 years. RESULTS: The 10-year survivorship free from any revision or implant removal was 89%, with 1 revision and 1 resection arthroplasty secondary to periprosthetic femoral fractures. The 10-year survivorship free from any reoperation was 42%, with 4 additional reoperations (2 ORIFs for periprosthetic femoral fractures, 1 sciatic nerve palsy lysis of adhesions, 1 hematoma evacuation). Harris hip scores significantly increased at 5 years (P = .04). Five hips had an intraoperative acetabular fracture, and 1 had an intraoperative femur fracture. All postoperative femoral fractures occurred in patients with intramedullary diameter less than 5 mm at a level 10 cm distal to the lesser trochanter. CONCLUSION: Primary THA in patients with osteopetrosis is associated with good 10-year implant survivorship (89%), but a very high reoperation (58%) and periprosthetic femoral fracture rate (44%). Femoral fractures appear associated with smaller intramedullary diameters.

Length of Stay, Discharge Disposition, and 90-Day Complications and Revisions Following Primary Total Hip Arthroplasty: A Comparison of the Direct Anterior, Posterolateral, and Direct Superior Approaches.

BACKGROUND: The direct anterior (DA) approach is becoming increasingly popular for primary total hip arthroplasty (THA). The aim of this study is to evaluate early postoperative complication and revision rates based on surgical approach, comparing DA, posterolateral (PL), and direct superior (DS) approaches. METHODS: After institutional review board approval, a total joint arthroplasty database from a single institution was used to identify all patients who underwent elective primary THA between July 2013 and November 2017 with a DA, PL, or DS hip approach. Patients were followed for complications out to 90 days postsurgery. Patients were divided into groups based on surgical approach and compared on length of stay, discharge disposition, and 90-day complication and revision rates. RESULTS: There were 5341 THA procedures performed, with 3162 PL, 1846 DA, and 333 DS approaches. Length of stay was shorter for DS (1.7 ± 0.9 days) and DA (1.8 ± 0.9 days) than for PL approaches (2.3 ± 1.4 days, P < .001) The DS approach had the highest rate of home discharges (93.1%), but the highest short-term revision rate (1.5%, P = .011). The DA approach had the lowest intraoperative fracture rate (0.1%, P = .019) but the highest incidence of postoperative fractures (1.3%, P = .021). There were no differences in readmission (P = .056), 90-day events (P = .062), emergency department visits (P = .210), dislocations (P = .090), combined perioperative fractures (P = .289), venous thromboembolic events (P = .059), or acute infection rates (P = .287). CONCLUSION: In the era of bundled payments, the DA, PL, and DS approaches can all be effectively used. LEVEL OF EVIDENCE: Level III; retrospective comparative study.

Order of Total Hip or Total Knee Arthroplasty Does Not Affect Length of Stay or Discharge Disposition in Patients With Coexisting Hip and Knee Arthritis.

Primary total joint arthroplasty (TJA) of the hip and knee are effective procedures for improving pain and function in patients with arthritis. This study examined whether order of surgery (TKA or THA first) affects length of stay (LOS) and discharge disposition among patients with coexisting knee and hip arthritis. A total joint arthroplasty database review was performed to collect all available data for arthroplasties performed at 2 campuses of a single institution between July 2013 and April 2017. Inclusion criteria were patients who underwent both primary THA and TKA within 18 months and were age 18 years or older. Patients were divided into 2 groups based on whether THA or TKA was performed first. For all procedures, the following data were collected: age, body mass index (BMI), time between cases, LOS, discharge disposition, and the number of 90-day adverse postoperative events. Adverse 90-day events included deep infection, fracture, hardware failure, urinary tract infection, other return to the operating room, emergency department visit, readmission, or death. A total of 211 patients underwent both THA and TKA within 18 months; 124 patients underwent THA first and 87 underwent TKA first. There was no difference in age or BMI between the 2 groups. There was a significantly longer time between the first and second arthroplasty in patients with TKA first by a mean of 2 months (P=.001). There was no difference in 90-day adverse postoperative events following THA whether done first or second (P=.371), and no difference in 90-day events following TKA whether done first or second (P=.524). There was no difference in discharge disposition (P=.833 and P=.395) or LOS (P=.695 and P=.473) between groups for the first or second procedure, respectively. In a patient with coexisting hip and knee arthritis, the current results do not support recommending THA or TKA first based on cost related to LOS and discharge disposition. [Orthopedics. 2019; 42(6):e528-e531.].

Analysis of Retrieved Unicompartmental Knee Implants and Tissue: Third-Body Wear as a Potential Contributor to Progression of Arthritis to Adjacent Compartments.

Unicompartmental knee arthroplasty (UKA) for the treatment of single-compartment osteoarthritis has been associated with polyethylene wear and progression of osteoarthritis into adjacent compartments, leading to revision. In this study, damage and clinical failure modes of retrieved UKA implants were investigated and protein expression profiles between articular cartilage adjacent to UKA and primary osteoarthritic cartilage were compared. Fifty retrieved UKA implants were analyzed for various damage. Records review and radiographic analysis were performed to collect clinical data and implant characteristics. Cartilage harvested from revision UKA and primary total knee arthroplasty surgeries was characterized with a proteome profiling array detecting levels of 36 different cytokines, chemokines, and acute phase inflammatory proteins. Progression of osteoarthritis (n=18, 36%) and component loosening (n=17, 34%) were the most common reasons for revision. Liners exhibited the highest frequency of damage modes. Progression of arthritis positively correlated with radiographic presence of extruded bone cement and burnishing of liner components. A protein-level profile between revision UKA and primary total knee arthroplasty cartilage showed 12 differentially expressed cytokines. Failure of UKA may be secondary to the effects of wear debris particulate migration into the adjacent compartment, suggesting an additional pathway of cartilage damage manifesting as traditional clinical symptoms. [Orthopedics. 2019; 42(3):149-157.].

Does Taper Design Affect Taper Fretting Corrosion in Ceramic-on-Polyethylene Total Hip Arthroplasty? A Retrieval Analysis.

BACKGROUND: Ceramic-on-polyethylene (CoP) implants have exhibited lower fretting and corrosion scores than metal-on-polyethylene implants. This study aims at investigating the effect of taper design on taper corrosion and fretting in modular CoP total hip arthroplasty (THA) systems. METHODS: Under an institutional review board--approved protocol, a query of an implant retrieval library from 2002 to 2017 identified 120 retrieved CoP THA systems with zirconia toughened alumina femoral heads. Femoral stem trunnions were visually evaluated and graded for fretting, corrosion, and damage at the taper interface. Medical records were reviewed for patient demographics and implant characteristics. Data were statistically analyzed using Spearman correlation and rank-sum tests with a Dunn's post hoc test, with a significance level of α = 0.05. RESULTS: Four different taper designs were evaluated: 11/13 (n = 18), 12/14 (n = 53), 16/18 (n = 21), and V40 (n = 28). There were no statistically significant demographic differences between taper groups for duration of implantation, laterality, patient age, and patient sex, but patients with 16/18 tapers had a higher body mass index than V40 tapers (P = .012). Duration of implantation had a weak positive correlation with both trunnion fretting (ρ = 0.224, P = .016) and corrosion (ρ = 0.253, P = .006). Summed fretting and corrosion scores were significantly greater on the V40 and 16/18 tapers compared with the 12/14 tapers (all P ≤ .001). CONCLUSION: Taper fretting and corrosion were observed in CoP THA implants and were greatest with V40 and 16/18 tapers and lowest with 12/14 tapers. Differences in taper design characteristics may lead to greater micromotion at the taper-head interface, leading to increased fretting and corrosion.

Development of a periprosthetic joint infection by Abiotrophia defectiva years after total knee arthroplasty.

A 74-year-old male presented with acute right knee pain and inability to ambulate. The patient had a total knee arthroplasty, previously complicated by a periprosthetic femur fracture requiring surgical fixation and subsequent methicillin-resistant Staphylococcus epidermidis periprosthetic joint infection treated via two-stage revision. Cultures from knee fluid aspiration were positive for Abiotrophia defectiva. Identification was confirmed using matrix-assisted laser desorption ionization-time of flight mass spectrometry. The patient underwent a two-stage revision. Between stages, the patient received intravenous ceftriaxone for six weeks with subsequent normalization of inflammatory markers. Diagnosis of periprosthetic joint infection with identification of the organism is important to guide appropriate treatment.

Fretting and Corrosion Damage of Retrieved Dual-Mobility Total Hip Arthroplasty Systems.

BACKGROUND: Dual-mobility (DM) total hip arthroplasty (THA) systems are designed to increase stability while potentially avoiding problems associated with large femoral heads. Complications of these systems are not yet fully understood. This study aims at characterizing in vivo performance of DM hip systems and assessing modes of clinical failure. METHODS: Under an institutional review board-approved implant retrieval protocol, 18 DM THA systems from 17 patients were included. Implants were graded at the head-neck junction for fretting and corrosion based on the system of Goldberg et al. Components were also macroscopically examined for different damage modes. Demographics and surgical data were collected from medical records, and radiographs were assessed for component positioning. Data were analyzed through Spearman rank-order correlation and Mann-Whitney U-tests, with α = 0.05. RESULTS: The average length of implantation was 13.4 months with mild to moderate fretting corrosion damage. Polyethylene (PE) liners exhibited edge deformation, scratching, and pitting damage. Metallic components exhibited burnishing and scratching damage. Summed fretting and corrosion scores were strongly correlated (ρ = 0.967, P < .0001). Summed corrosion score was moderately correlated with presence of embedding on the PE liner (ρ = 0.690, P = .017). PE liner abrasion and edge deformation of the femoral stem taper were moderately positively correlated (ρ = 0.690, P = .017). Fretting and corrosion damage were not significantly correlated with patient demographics or radiographic positioning of implants. There were no differences in scores between modular and monoblock designs. CONCLUSION: These findings demonstrate that dual-mobility THA systems may be susceptible to the same fretting and corrosion damage observed in traditional modular THA systems. Future studies are needed to confirm these results and clinical significance.

Treatment of Patella Fractures.

Patella fractures comprise 1% of all fractures. Treatment options vary based on fracture displacement, classification, and patient factors. Traditionally, nonoperative treatment has been reserved for nondisplaced fractures. Many operative treatments are available with differing indications and levels of success. Tension band constructs have been the most commonly employed approach to fixation, with cerclage wiring for comminuted fractures. Recently, plate fixation of patella fractures has become more popular. Plating constructs offer a low-profile design with stable fixation, allowing for earlier mobilization and potentially improved functional outcomes. Data regarding the long-term outcomes of plating techniques are limited, and further studies are needed. [Orthopedics. 2018; 41(6):e747-e755.].

Current Trends in Patient-Reported Outcome Measures in Total Joint Arthroplasty: A Study of 4 Major Orthopaedic Journals.

BACKGROUND: More emphasis is being placed on patient-reported outcome measures (PROMs), but the myriad of PROMs makes standardization and cross-study comparison difficult. As the era of big data and massive total joint registries matures, it will be critical to identify and implement the best PROMs. METHODS: All abstracts published in the years 2004, 2009, 2014, and 2016 in the Journal of Bone and Joint Surgery-American volume, the Bone and Joint Journal, Clinical Orthopedics and Related Research, and the Journal of Arthroplasty were reviewed. A PubMed search was performed with filters limiting results only to total knee, total hip, and unicompartmental knee arthroplasty articles with available abstracts. Each abstract was reviewed to identify all PROMs. Trends over time were evaluated using the Cochran-Armitage test. In the non-trend analysis, Pearson chi-square tests and one-way analysis of variance were performed. RESULTS: A total of 42 unique PROMs were used 1073 times across 644 studies. The number of PROMs in these 4 journals increased from 97 in 2004 to 228 in 2016 (P < .0001). The proportion of articles with more than one PROM increased from 20.6% in 2004 to 47.8% in 2016 (P = .0001). The most common PROMs used in total knee, total hip, and unicompartmental knee arthroplasty studies were the Knee Society Score, the Harris Hip Score, and the Oxford Knee Score, respectively. CONCLUSION: Providers and registries should consider the relative prevalence of published outcome measures when selecting which PROMs to use, to better facilitate future cross-study comparison.

The Role of Aspirin and Unfractionated Heparin Combination Therapy Immediately After Total Hip and Knee Arthroplasty.

Aspirin and unfractionated heparin (UH) are accepted options for venous thromboembolism (VTE) prophylaxis after total joint arthroplasty (TJA). The use of aspirin in addition to UH in preventing VTE after TJA has yet to be studied. The primary objective of this study was to determine VTE rates in patients receiving aspirin monotherapy and those receiving aspirin and UH combination therapy immediately following TJA. A TJA database from a single hospital system was retrospectively reviewed to identify all patients who underwent primary hip or knee arthroplasty from 2013 to 2016. Patients were divided into 3 groups based on postoperative VTE chemoprophylaxis: aspirin only, aspirin with 1 dose of UH, and aspirin with multiple doses of UH. There were 5350 patients included: 1024 aspirin only, 1695 aspirin plus 1 dose of UH, and 2631 aspirin plus multiple doses of UH. Deep venous thrombosis and pulmonary embolus rates did not vary significantly between groups (deep venous thrombosis: 1.1%, 0.9%, and 1.2%, respectively, P=.701; pulmonary embolus: 0.3%, 0.3%, and 0.2%, respectively, P=.894). Transfusion rates were significantly greater with 1 dose of UH (1.8%) and multiple doses of UH (4.3%) compared with aspirin only (0.9%) (P<.001). Additionally, the postoperative hemoglobin decreased significantly more postoperatively with the use of UH (P<.001). Aspirin and UH combination therapy did not decrease VTE incidence compared with aspirin monotherapy. Additionally, there was greater perioperative blood loss and an increased rate of blood transfusion in patients receiving UH. On the basis of these findings, the authors do not recommend UH as an additional mode of VTE prophylaxis when prescribing aspirin after elective TJA. [Orthopedics. 2018; 41(3):171-176.].

Multidrug-Resistant Organisms in the Setting of Periprosthetic Joint Infection-Diagnosis, Prevention, and Treatment.

BACKGROUND: Periprosthetic joint infection (PJI) is a rare yet challenging problem in total hip and knee arthroplasties. The management of PJI remains difficult primarily due to the evolution of resistance by the infecting organisms. METHODS: This review profiles acquired mechanisms of bacterial resistance and summarizes established and emerging techniques in PJI diagnosis, prevention, and treatment. RESULTS: New techniques in PJI diagnosis and prevention continue to be explored. Antibiotics combined with 1 or 2-stage revision are associated with the higher success rates and remain the mainstay of treatment. CONCLUSION: With higher prevalence of antibiotic-resistant organisms, novel antibiotic implant and wound care materials, improved methods for organism identification, and well-defined organism-specific treatment algorithms are needed to optimize outcomes of PJI.

Cost Analysis, Complications, and Discharge Disposition Associated With Simultaneous vs Staged Bilateral Total Knee Arthroplasty.

BACKGROUND: Simultaneous vs staged bilateral total knee arthroplasty (BTKA) has long been debated. The primary objective of this study was to compare actual hospital costs and complication rates in patients undergoing simultaneous BTKA (simBTKA) and staged BTKA (staBTKA) at a single institution. METHODS: A total joint arthroplasty database from a single hospital was used to identify all patients who underwent primary BTKA from 2013 to 2016 and divided into simultaneous and staged groups. StaBTKA patients were included if both procedures were performed within 1 year by the same surgeon. The combined total hospital cost of both procedures was used, and inpatient rehabilitation (IPR) costs were added for all patients discharged to IPR. RESULTS: There were 225 simBTKA and 337 staBTKA patients. SimBTKA patients were younger (61 ± 8 vs 66 ± 8 years, P < .001), had lower body mass index (31.3 ± 5.9 vs 34.0 ± 7.2, P < .001), were more predominately male (48% vs 38%, P = .029), and more likely to require IPR as compared with staBTKA patients. There was no difference in total hospital cost for simBTKA as compared with staBTKA ($24,596 ± $5652 vs $24,915 ± $5756, P = .586). Complications were more prevalent in the simBTKA group, including venous thromboembolism (5.4% vs 1.4%, P = .006) and blood transfusions (15.8% vs 6.2%, P < .001). CONCLUSION: There were higher complication rates with no significant cost savings in actual hospital costs associated with simBTKA, when accounting for the cost of IPR, as compared with staBTKA. The total cost analysis of simBTKA vs staBTKA, using actual cost data, merits further evaluation.

Fretting and Corrosion Damage in Retrieved Metal-on-Polyethylene Modular Total Hip Arthroplasty Systems: What Is the Importance of Femoral Head Size?

BACKGROUND: Fretting and corrosion at the modular femoral head-femoral neck (taper) interface have been reported in retrieved total hip arthroplasty (THA) prostheses. This study investigated associations among implant design, radiographic factors, and patient factors with corrosion and fretting at the taper interface in retrieved metal-on-polyethylene modular THA prostheses. METHODS: Ninety-two retrieved primary metal-on-polyethylene THA implants were evaluated and graded for fretting, corrosion, and damage at the taper interface, including the femoral stem trunnion and femoral head. Preoperative radiographs were assessed for osteolysis and femoral stem alignment; and medical records were reviewed for demographic data. RESULTS: Male patients had greater head corrosion (P = .037), patient age at revision had a weak, negative correlation with trunnion corrosion (ρ = -0.20, P = .04), and both body mass index and duration of implantation had weak, positive correlations with head fretting (ρ = 0.26, P = .01 and ρ = 0.33, P = .001, respectively). A weak, negative correlation was found between femoral head size and both head fretting and head corrosion (ρ = -0.26, P = .007 and ρ = -0.21, P = .028, respectively), and a weak, positive correlation was found between head offset and trunnion fretting (ρ = 0.23, P = .030). Varus femoral stem alignment was associated with greater head fretting (P = .038). CONCLUSION: Larger femoral head sizes were correlated with less severe head corrosion and head fretting, with 28-mm heads exhibiting more moderate-to-severe damage. Other factors, such as head-taper engagement and geometry, rather than head size, may affect rates of corrosion and fretting damage at the taper interface.

Factors Driving Patient Perception of Quality Care After Primary Total Hip and Total Knee Arthroplasty.

INTRODUCTION: Differences in female and male patient perception of care and satisfaction following primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) were assessed via Hospital Consumer Assessment of Healthcare Providers and Systems survey, demographic, and clinical data. METHODS: After institutional review board approval, a retrospective review of the Hospital Consumer Assessment of Healthcare Providers and Systems survey responses at a private, academic, level-I trauma center was performed from January 2011 to December 2013. Inclusion criteria were primary THA and TKA patients who were 18 years or older and returned the survey. RESULTS: Overall, 1,166 THA and 1,411 TKA were included, with 55.0% of female THA patients and 64.5% of male THA patients highly satisfied (P = 0.002). The mean overall hospital rating was 7.2 for female THA and 7.8 for male THA (P = 0.003) patients. No significant differences was found in the TKA cohort. For all cohorts, the Nurse Communication with Nurses domain reported the greatest correlation with overall hospital rating (range, ρ = 0.418 to ρ = 0.502; P < 0.0001). DISCUSSION: This series indicated that initiatives to improve patient care and patient perception of care should focus on nurse-patient communication, hospital staff responsiveness, the care transition process, and hospital environment. Patient sex was a significant factor in the overall satisfaction for THA, with female patients reporting significantly lower ratings than male patients.