Acute Periprosthetic Hip Fractures With Short, Uncemented Femoral Stems.

BACKGROUND: Uncemented femoral stems in hip arthroplasty have shown excellent long-term results, and several systematic studies indicate satisfactory performance of short stems. However, biomechanical and finite element analysis studies have suggested that shorter stems allow greater micromotion, producing greater strain at the implant-bone interface, which potentially increases the risk for periprosthetic fracture (PPF). We sought to assess this risk within our unit. METHODS: Our institution's arthroplasty database was searched for all primary total hip arthroplasties using short femoral stems performed between July 14, 2009 and August 29, 2022. The overall PPF rate and the PPF rate for individual femoral stems were established. Preoperative X-rays for each case were analyzed to characterize individual proximal femoral geometry. A data analysis was performed to identify risk factors for PPF. RESULTS: For the time period assessed, 3,192 short femoral stems were implanted. This included 1,561 of stem A and 1,631 of stem B. Women constituted 55.37% of the cohort. The average patient age was 66 years (range, 22 to 95). The PPF rate was 0.6%, with 19 PPFs identified at a follow-up of 3 months. There was a significantly higher fracture rate in stem A (0.96%) compared to stem B (0.25%) (P ≤ .01). Proximal femoral geometry, age, and sex were not determined to be risk factors for PPF in our cohort. Individual surgeons and surgical approaches appeared to confer no increased risk. There was no significant difference in average stem length, but multivariate analysis identified stem type and stem length as an independent risk factor for PPF. CONCLUSIONS: Our study identified individual stem and stem length as independent risk factors for PPF within our cohort. PPF is a multifactorial issue, and consensus on emerging risk factors such as implant design will hopefully inform decisions that can provide further risk reduction for individual patients.

Similar complication and readmission rates following simultaneous versus staged bilateral total hip arthroplasty.

PURPOSE: To compare short-term complications and readmission rates, in patients treated with simultaneous versus staged bilateral total hip arthroplasty (THA) within a year from the index procedure. METHODS: We reviewed the charts of patients that underwent simultaneous and staged-within a year-bilateral THA, between 2016 and 2020. Preoperative baseline characteristics were evaluated, while differences in terms of 30-day major and 30-day minor complications and readmission rates were compared between the groups. RESULTS: One-hundred-sixty patients (mean age, 64.3 years; SD, ± 11.7) were identified. Seventy-nine patients were treated with simultaneous (Group A) and eighty-one patients with staged (Group B) THA. There were no differences in baseline characteristic between the two groups (p > 0.050). Group A was more likely to receive general anesthesia (43% vs. 9.9%, p < 0.001) and had longer total operative time (182.8 vs. 128.0 min, p < 0.001). Group A had an overall shorter total length of hospital stay (5.8 vs. 8.6 days, p < 0.001). No differences in transfusion rates (p = 0.229) and no differences in major and minor complications (p > 0.05) were identified. Postoperative visits at the emergency department or readmissions were similar between the two groups (p > 0.050). CONCLUSION: This study shows that similar complication and readmission rates are expected after simultaneous and staged THA. Simultaneous bilateral THA is a safe and effective procedure, that should be considered for patients that present with radiologic and clinical bilateral hip disease.

Outcomes of Ceramic-On-Ceramic Bearing Total Hip Arthroplasty: A Minimum 10-Year Follow-Up Study.

BACKGROUND: Although the fourth generation of ceramics has demonstrated excellent clinical results 5 to 6 years postoperatively, concerns over ceramic fracture and squeaking persist and longer-term follow-up (minimum 10 years) studies are warranted. Our study aimed to evaluate the minimum 10-year clinical outcomes and bearing-specific complications of ceramic-on-ceramic (CoC) total hip arthroplasties. METHODS: We retrospectively evaluated all patients who underwent primary delta CoC total hip arthroplasty in our institution between January 2004 and February 2013. Demographics, surgical techniques, complications, patient-reported outcomes, and radiographic outcomes were collected and analyzed. For continuous variables, the comparison between groups was conducted using a one-way analysis of variance. Of all 235 patients included in the study, 70.5% were women (190 hips). The mean follow-up period was 12 years (range, 10 to 18). The femoral head sizes of 28- mm, 32 mm, and 36 mm were used in 50, 26, and 197 cases, respectively. Mean acetabular inclination and anteversion angles were 39.2 ± 7.1° and 14.9 ± 3.5°. RESULTS: There were 5 hips revised at a mean 4.6 years (range, 0.1 to 7.1). One revision was squeaking-related. Squeaking was also reported by 8 other patients, but did not require revision. Other reasons for revision were early infection in 2 cases, stem loosening in 1 case, and stem fracture in 2 cases. The survival analysis for any causes for revision as an endpoint was 96.7% (95% confidence interval 0.313%-2.57%). CONCLUSION: We report excellent mean 12-year follow-up results regarding the complications and survivorship of the fourth generation CoC bearings.

Indication for total knee arthroplasty based on preoperative functional score: Are we operating earlier?

BACKGROUND: The number of total knee arthroplasty (TKA) procedures performed annually is increasing for reasons not fully explained by population growth and increasing rates of obesity. The purpose of this study was to determine the role of patient functional status as an indication for surgery and to determine if patients are undergoing surgery with a higher level of preoperative function than in the past. METHODS: A systematic review and meta-analysis of the MEDLINE, Embase and Cochrane databases was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Functional status was assessed using the 36-Item Short Form Health Survey's physical component summary (PCS) score. Only primary procedures were included. Articles were screened by 2 independent reviewers, with conflicts resolved with a third reviewer. Meta-regression analysis was performed to determine the effect of time, age and sex on preoperative PCS score. Subgroup analysis was performed to compare results for the United States with those for the rest of the world. RESULTS: A total of 1502 articles were identified, of which 149 were included in the study. Data from 257 independent groups including 57 844 patients recruited from 1991 to 2015 were analyzed. The mean preoperative PCS score was 31.1 (95% confidence interval 30.6-31.7) with a 95% prediction interval of 22.8-39.5. The variance across studies was found to be significant (p < 0.001) with 99.01% true variance. Year of enrolment, age, the percentage of female patients and geographic region did not have any significant effect on preoperative PCS score. CONCLUSION: Patients are undergoing TKA with a level of preoperative function similar to their level of function in the past. Patient age, sex and location did not influence the functional status at which patients were considered to be candidates for surgery.

Elective Total Hip Arthroplasties in Nonagenarians-Age Does Matter: A National Surgical Quality Improvement Program Study.

BACKGROUND: The aim of this study is to assess the independent effect of age on the risk of postsurgical complications and death in patients undergoing total hip arthroplasty (THA). METHODS: The National Surgical Quality Improvement Program was used to identify all patients aged 65 years and older who underwent primary THA from 2011 to 2017. Study outcomes were minor complications, major life-threatening complications, and 30-day mortality. Predictors of outcomes were identified using bivariate analyses and age was added into the final logistic regression models with stepwise selection. RESULTS: A total of 74,361 patients were included in the analysis. Mean (standard deviation) age was 735 years (6.46), median 72.0 years; 1,119 (1.50%) patients were ≥90 years. Females comprised 60.6% of the patient sample. The incidence of major life-threatening complications, minor complications, and death was 939/74,361 (1.3%), 2,098 (2.8%) and 154 (0.2%) respectively. When added to the final models, age was significantly associated with an increased risk of postoperative complications and mortality. CONCLUSION: Elective THA in relatively healthy nonagenarians should only be considered among patients with disabling osteoarthritis demonstrating a restricted quality of life. Although THA can substantially improve patient wellbeing, our findings suggest that surgeons and patients must consider the impact of age on patient course and outcomes regardless of the presence of comorbidities. LEVEL OF EVIDENCE: Level II, prognostic study.

Patient Functional Status as an Indication for Primary Total Hip Arthroplasty: A Systematic Review and Meta-Analysis.

BACKGROUND: The number of total hip arthroplasties performed per year is increasing for reasons not fully explained by a growing and aging population. The purpose of this study was to determine the role of patient functional status as an indication for surgery and determine if patients are undergoing surgery at a better functional status than in the past. METHODS: A systematic review and meta-analysis of the MEDLINE, EMBASE, and Cochrane databases was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Functional status was assessed using the 36-Item Short-Form Health Survey's Physical Component Summary score. Only primary procedures were included; revisions were excluded. Articles were screened by 2 independent reviewers with conflicts resolved with a third reviewer. Meta-regression analysis was performed to determine the effect of time, patient age, and gender. Subgroup analysis was performed to compare geographic regions. RESULTS: A total of 1504 articles were identified. Data from 172 groups representing 18,644 patients recruited from 1990 to 2013 and identified from 107 articles were included. The mean preoperative Physical Component Summary score was 31.2 (95% confidence interval 30.5-31.9) with a 95% prediction interval of 22.6-39.8. The variance across studies was statistically significant (P = .000) with 97.25% true variance. Year of enrollment, age, and the percentage of females were not found to have any significant effect. There were no differences between countries. CONCLUSION: Patients are undergoing total hip arthroplasty at a similar preoperative physical functional status as in the past. Patient age, gender, and location do not influence the functional status at which patients are indicated for surgery.

Long-Term Survivorship of Cemented and Uncemented Polyethylene Liner Exchange.

BACKGROUND: Revision surgery is usually required for complications associated with total hip arthroplasty (THA). Significant morbidity can be associated with revision THA and thus some may only revise the liner of the original metal back component if it is found to be well fixed. We compare the long-term survivorship of cemented and uncemented head-liner THA exchange surgeries and possible causes. METHODS: Between 2000 and 2018, we reviewed cases from our arthroplasty database who underwent THA revision for head-liner exchange. We stratified our cohort into 2 groups: cemented and uncemented liners. Patients were followed clinically and radiographically to determine survivorship of the exchanges for both cemented and uncemented liners. Implant survivorship was measured using a competing risk analysis considering death and patients lost to follow-up as competing risks. RESULTS: A total of 84 patients (85 hips) underwent head-liner exchange surgery during the study period (21 cemented and 64 uncemented liners). The mean follow-up time was 6.9 years, with 75.3% and 24.7% of patients having been revised due to non-dislocation and dislocation causes, respectively. Two cemented liners (9.5%) and 11 uncemented liners (17.2%) required revision. The survival analysis of all head-liner revision was 86.4% at 18 years. Survival estimates liner exchanges due to dislocation versus non-dislocation groups were 57.3% versus 82.7% respectively (P = .034). CONCLUSION: The present study shows improved survivorship of head-liner exchanges performed due to non-dislocation etiology compared to dislocation etiology, but no difference in survivorship between cemented and uncemented head-liner exchange. LEVEL OF EVIDENCE: Level III.

Long-Term Outcome of Small Head Metal-On-Metal Total Hip Arthroplasty: A 15-to-22 Year Follow-Up.

BACKGROUND: The Metasul articular interface was a second-generation metal-on-metal (MoM) total hip arthroplasty (THA) that was introduced as a promising interface with improved manufacturing technology, better clearances, and enhanced metal hardness. In December 2001, the manufacturer recalled these implants due to the failure of cup osseointegration. METHODS: Between 1997 and 2004, 168 consecutive primary Metasul THAs were performed in 144 patients. Most patients received a cementless femoral and porous-coated acetabular component with 28 mm head. A competing risk analysis was performed for determination separately for bearing surface-related, recalled bearing failure, and end point revision for any reason. For clinical patient evaluation, we used Harris hip score and University of California at Los Angeles scores. Cobalt and chromium ion level measurement and standard radiographic assessment was performed. RESULTS: Of the 168 THAs, 19 hips were revised at a mean period of 15 years as follows: 12 of them were due to recalled acetabular component, five hips had noninterface-related complication, and two true interface surface failure. The survival distribution function of all hips with revision for any reason was 88.4%, for bearing interface relation 98.8%, and 92.6% for recalled cups. The mean Harris hip score and University of California at Los Angeles scores were 85 and 6, respectively, and the median Co and Cr blood levels were 1.0 and 0.91 µg/L. CONCLUSION: Excluding the recalled components, Metasul articular interface has performed extremely well at a minimum follow-up of 15 years in this relatively young population. There were two interface-related revisions in the entire cohort.

The Influence of Lateral and Posterior Total Hip Arthroplasty Approaches on Muscle Activation and Joint Mechanics During Gait.

BACKGROUND: Lateral and posterior total hip arthroplasty (THA) approaches disrupt muscle function, which could impact gait. The objectives of this study were to compare muscle activation and joint mechanics during gait, and isometric strength between participants after lateral and posterior THA approaches and healthy adults. METHODS: Participants 1 year post-THA from either lateral (n = 21) or posterior (n = 21) approaches, and healthy adults (n = 21) ambulated at self-selected speeds. Surface electromyography, optical motion capture, and force plates measured muscle activation and joint mechanics during gait. A dynamometer measured isometric torque. Gait characteristics and isometric torque were compared using analysis of variance and effect sizes (d). RESULTS: Lateral THA group had higher gluteus medius amplitudes during gait compared to the healthy group (P < .01, d = -0.97). Posterior THA group had higher gluteus maximus amplitudes during loading response (P = .02, d = -0.94) and higher hamstring amplitudes during midstance (P = .02, d = 0.45-1.31) than the healthy group. Both THA groups had decreased hip flexion and adduction angle excursions during gait (d = 0.89-1.14), but increased medial rotation angle excursions (d = -1.06 to -0.91), compared to the healthy group. Lateral THA group had lower isometric hip abduction torque than the healthy group (P = .03, d = 0.74). There was no pelvic drop in the THA groups. CONCLUSION: There were few differences in gait and isometric torque between lateral and posterior THA groups. The elevated muscle activation amplitudes in the lateral and posterior THA groups compared to healthy adults were likely due to muscle weakness. Despite these findings, there was no evidence of pelvic drop.

No Difference in Major Complication and Readmission Rates Following Simultaneous Bilateral vs Unilateral Total Hip Arthroplasty.

BACKGROUND: Simultaneous bilateral total hip arthroplasty (THA) is an attractive option for patients with osteoarthritis as it requires a single anesthetic and hospitalization. Nonetheless, serious concerns remain over the perioperative safety and rate of hospital readmission. The purpose of the present study was to compare the rate of 30-day major complications and hospital readmissions between patients undergoing simultaneous bilateral vs unilateral THA using the National Surgical Quality Improvement Program database. METHODS: The National Surgical Quality Improvement Program database was queried from 2011 to 2015 inclusively to identify all cases of elective, primary simultaneous bilateral THA and match them to a control group of unilateral THA cases. A multivariable regression analysis was then used to assess the relationship of simultaneous bilateral vs unilateral THA on major complications and readmissions. RESULTS: A total of 575 bilateral THA patients were matched to 2290 unilateral THA patients using a 4:1 ratio based on age, sex, and American Society of Anesthesiologists scores. Bilateral THA patients were more likely to undergo general anesthesia (77% vs 58.7%, P < .0001), required more postoperative transfusions (29.2% vs 15.9%, P < .0001) and were more often discharged to a rehabilitation facility rather than home (39.4% vs 20.8%, P < .0001). However, the adjusted odds of a major complication (odds ratio = 0.72, 95% confidence interval [0.41-1.24], P = .24) and 30-day readmission (odds ratio = 0.67, 95% confidence interval [0.38-1.19], P = .17) were similar between the 2 groups. CONCLUSION: Although patients who underwent simultaneous bilateral THA were more likely to be discharged to a rehabilitation facility and required significantly more perioperative transfusions compared to those undergoing unilateral THA, the odds of a 30-day major complication and readmission were similar between groups. LEVEL OF EVIDENCE: III.

Prostaglandin E2-Dependent Phosphorylation of RAS Inhibition 1 (RIN1) at Ser 291 and 292 Inhibits Transforming Growth Factor-ß-Induced RAS Activation Pathway in Human Synovial Fibroblasts: Role in Cell Migration.

Prostaglandin E2 (PGE2 )-stimulated G-protein-coupled receptor (GPCR) activation inhibits pro-fibrotic TGFß-dependent stimulation of human fibroblast to myofibroblast transition (FMT), though the precise molecular mechanisms are not fully understood. In the present study, we describe the PGE2 -dependent suppression and reversal of TGFß-induced events such as α-sma expression, stress fiber formation, and Ras/Raf/ERK/MAPK pathway-dependent activation of myofibroblast migration. In order to elucidate post-ligand-receptor signaling pathways, we identified a predominant PKA phosphorylation motif profile in human primary fibroblasts after treatment with exogenous PGE2 (EC50 30 nM, Vmax 100 nM), mimicked by the adenyl cyclase activator forskolin (EC50 5 µM, Vmax 10 µM). We used a global phosphoproteomic approach to identify a 2.5-fold difference in PGE2 -induced phosphorylation of proteins containing the PKA motif. Deducing the signaling pathway of our migration data, we identified Ras inhibitor 1 (RIN1) as a substrate, whereby PGE2 induced its phosphorylation at Ser291 and at Ser292 by a 5.4- and 4.8-fold increase, respectively. In a series of transient and stable over expression studies in HEK293T and HeLa cells using wild-type (wt) and mutant RIN1 (Ser291/292Ala) or Ras constructs and siRNA knock-down experiments, we showed that PGE2 -dependent phosphorylation of RIN1 resulted in the abrogation of TGFß-induced Ras/Raf signaling activation and subsequent downstream blockade of cellular migration, emphasizing the importance of such phosphosites in PGE2 suppression of wound closure. Overexpression experiments in tandem with pull-down assays indicated that specific Ser291/292 phosphorylation of RIN1 favored binding to activated Ras. In principal, understanding PGE2 -GPCR activated signaling pathways mitigating TGFß-induced fibrosis may lead to more evidence-based treatments against the disease. J. Cell. Physiol. 232: 202-215, 2017. © 2016 Wiley Periodicals, Inc.

Major Complications and Transfusion Rates After Hemiarthroplasty and Total Hip Arthroplasty for Femoral Neck Fractures.

BACKGROUND: Postoperative complications and perioperative transfusions are common after hemiarthroplasty or total hip arthroplasty (THA) and can lead to increased morbidity and mortality. METHODS: The National Surgical Quality Improvement Program Database was queried to compare 30-day major complications and perioperative transfusions after femoral neck fractures. RESULTS: A total of 4058 patients were included in the study: 3192 were treated with hemiarthroplasty and 866 with THA. Multivariable logistic regression analysis revealed that having a THA was not an independent risk factor for major complications (odds ratio = 0.8, P = .18) but was an independent risk factor for requiring transfusions (odds ratio = 1.68, P < .001). CONCLUSION: The risk of major complications is influenced by patient factors rather than the choice of procedure. However, THA was a risk factor for transfusions after controlling for all other variables.

Shorter Hospital Stay and Lower 30-Day Readmission After Unicondylar Knee Arthroplasty Compared to Total Knee Arthroplasty.

BACKGROUND: Reducing hospital stay and unplanned hospital readmission of arthroplasty patients has been a topic of recent interest. The aim of the present study was to query the National Surgical Quality Improvement Program database to compare the length of hospital stay (LOS) and the subsequent 30-day hospital readmission rates in patients undergoing primary unicondylar knee arthroplasty (UKA) and total knee arthroplasty (TKA). METHODS: We identified 1340 UKAs and 36,274 TKAs over a 2-year period (2011-2012). Patient demographics, comorbidities, LOS, 30-day postoperative complications, and readmission rates were compared between the groups. Multivariate regression analysis was used to determine the effect of procedure type on LOS and readmission rates. RESULTS: Unicondylar knee arthroplasty patients had a median LOS of 2 days compared to 3 days for TKAs (P < .001). The readmission rate in the TKA group was nearly double that of the UKA group (4.1% vs 2.2%) (P < .0001). Multivariate regression analysis identified that undergoing a UKA was predictive for a shorter LOS (coefficient -1 day) and was protective for 30-day readmission (odds ratio, 0.60; 95% confidence interval, 0.41-0.88). CONCLUSION: Patients undergoing UKA had a shorter LOS and a lower 30-day readmission rate compared to TKA patients. After adjusting for selected cofounders, we demonstrated that undergoing a UKA is a protective factor for 30-day readmission.

Simultaneous Bilateral Versus Unilateral Total Knee Arthroplasty: A Comparison of 30-Day Readmission Rates and Major Complications.

We queried the National Surgical Quality Improvement Program to compare the rate of 30-day readmissions and major complications between simultaneous bilateral and unilateral total knee arthroplasty (TKA). We identified 1771 patients who underwent simultaneous (same-day) bilateral TKA and matched them to a control group of 6790 patients who underwent unilateral TKA. The simultaneous bilateral TKA patients had longer surgery, were more commonly performed under general anesthesia, had a higher rate of postoperative transfusion, and a greater proportion of patients discharged to rehabilitation facilities. Simultaneous bilateral TKA has a low incidence of major complications and was not associated with more readmissions as compared to unilateral TKA (3.6% versus 3.5% respectively). Nonetheless, the odds of major complications was slightly higher following simultaneous bilateral TKA (OR=1.58).

Favorable Results of a Short, Tapered, Highly Porous, Proximally Coated Cementless Femoral Stem at a Minimum 4-Year Follow-Up.

BACKGROUND: Shorter femoral stems have been increasingly used in total hip arthroplasty. However, there are few clinical studies evaluating the outcomes of these stems and comparing them to their regular-sized counterparts. METHODS: Our study provides radiologic and functional outcomes at 5-year mean follow-up of 131 cementless Tri-Lock Bone Preservation Stems, a short tapered stem with a proximal porous coating. RESULTS: Stem-related complications were low with one revision for stem aseptic loosening. Kaplan-Meier analysis estimated 99.2% stem survival rate at 5 years, comparable to conventional length Tri-Lock stems (99.8% at 8.9 years). CONCLUSION: This study demonstrates that the Tri-Lock Bone Preservation Stem can provide successful outcomes at 5-year follow-up. Further studies are required to determine the long-term outcome of these implants in patients with poor bone stock.

Navigated vs Conventional Total Knee Arthroplasty: Is There a Difference in the Rate of Respiratory Complications and Transfusions?

BACKGROUND: Proponents of navigation in total knee arthroplasty (TKA) report lower rates of systemic embolization and perioperative bleeding compared to conventional TKA given that breeching the intramedullary canal is not required. METHODS: We queried the National Surgical Quality Improvement Program to compare perioperative respiratory complications and transfusions between navigated and conventional TKA. We identified 2008 patients who underwent navigated TKA. These patients were matched 4:1 to a control group of 8026 patients. RESULTS: Conventional TKA resulted in similar odds of having a respiratory complication compared to navigated TKA (odds ratio = 1.35, P = .44). However, conventional TKA was found to be an independent predictor for requiring a transfusion perioperatively (odds ratio = 1.90, P < .001). CONCLUSION: Use of navigation in TKA results in less perioperative transfusions but has no influence on the rate of respiratory complications.

Action mechanism of small and large molecule surfactant-based clove oil nanoemulsions against food-borne pathogens and real-time detection of their subpopulations.

Flow cytometry exactly discriminated three subpopulations, i.e., viable, damage and sublethal cells of L. monocytogenes, S. aureus and E. coli when treated at their MIC values. Purity gum ultra (PGU) a large molecule surfactant-based CO nanoemulsion exerted significant impact on cellular subpopulations of L. monocytogenes and S. aureus, with more membrane-damaged cells. On the other hand, when compared with bulk CO the results showed minimum membrane damage and more viable cells, whereas PGU CO nanoemulsion showed minimum effect on cellular subpopulation and represented more viable than damaged cells in case of E. coli. Similarly, Tween 80 a small molecule surfactant-based CO nanoemulsion showed limited overall activity against three tested microorganisms with more viable cells. We conclude that it was due to sequestration of CO constituents in interfaces, less availability in aqueous phase and finally inhibit bactericidal activity. Moreover, both CO and CO nanoemulsions showed membrane damage as primary inactivation mechanism of tested bacterial cells.

The chemokine CCL20 induces proinflammatory and matrix degradative responses in cartilage.

INTRODUCTION: Local inflammation plays a role in the pathophysiology of osteoarthritis (OA) and chemokines exert catabolic effects on articular cartilage either through paracrine and/or autocrine mechanisms. We sought to compare the expression levels of the chemokine (C-C motif) ligand 20 (CCL20) and its chemokine receptor 6 (CCR6) in donor and osteoarthritic (OA) cartilage and to investigate the role of CCL20 in the pathogenesis of OA and chondrocyte phenotype. METHODS: Cartilage/chondrocytes from donor and OA knee joints was analyzed for CCL20 and CCR6 expression by RT-PCR and immunohistochemistry. Effects of CCL20 on cytokines and mediators of cartilage degradation were examined by RT-PCR for mRNA expression levels, enzyme-linked immunosorbent assays, and proteoglycan (GAG) assays. RESULTS: CCL20 and CCR6 proteins were abundantly expressed in OA cartilage sections compared to donor sections as judged by immunohistochemistry. RT-PCR of cartilage extracts confirmed the predominance of CCL20/CCR6 mRNA expression in OA cartilage. CCL20 mRNA expression was low in donor chondrocytes but increased after stimulation with proinflammatory cytokines. mRNA expression levels of IL-6, cyclooxygenase-2, and iNOS were elevated in donor chondrocyte cultures treated with rhCCL20. The release of MMP1/13, PGE2, proteoglycan GAG fragments, and IL-6 from cartilage explant cultures was markedly augmented in the presence of CCL-20. CCL-20 stimulated MMP-13, ADAMTS-5, and col type X mRNA but inhibited col type II mRNA expression in freshly explanted and cultured cartilage specimens. CONCLUSIONS: CCL20/CCR6 may play an important role in the pathogenesis of OA by inducing changes in phenotype and catabolic gene expression in chondrocytes.

Midterm Outcomes of the Recently FDA Approved Ceramic on Ceramic Bearing in Total Hip Arthroplasty Patients Under 65 Years of Age.

The present study aimed to evaluate the mid-term results of the fourth generation of ceramic on ceramic (CC) bearing. Demographics, surgical technique, complications, clinical and radiologic outcomes were analyzed in a series of 133 consecutive CC total hip arthroplasties (THAs) with a newest generation CC bearings to determine if these provide safe and well performing bearings. At the last follow-up, there were no cases of ceramic fracture or chipping and no revision surgery necessary for bearing related complication. One hip underwent two staged revision for infection and another underwent revision for dislocation, resulting in an overall 98.5% survival rate at a mean of 6 years. The newest generation of CC bearings provides a reliable and safe bearing in young, active patients undergoing THA.