Direct Anterior Approach and Perioperative Fracture With a Single-Taper Wedge Femoral Component.

BACKGROUND: Despite growing interest in direct anterior approach total hip arthroplasty, perioperative femoral fracture and early aseptic loosening are increasingly recognized complications. Previous research has documented the role of surgeon experience in association with these femoral complications. The purpose of this study was to explore the relationship between femoral component design and early periprosthetic femoral complications. METHODS: This was an extension of previous work with an updated patient cohort of 5090 consecutive direct anterior primary total hip arthroplasties at a single institution with a single-taper, wedge femoral stem comprising 4 variants involving length and geometry: group 1, full-length, standard profile; group 2, full-length, reduced distal profile; group 3, short-length, standard profile; and group 4, short-length, reduced distal profile. Records were reviewed retrospectively for the incidence of early postoperative periprosthetic fracture or aseptic loosening and analyzed with regard to patient demographics and femoral stem type. RESULTS: There were 42 (0.83%) periprosthetic femur complications observed in the early postoperative period. Increased age (P < .001) and female gender (P = .023) were significantly associated with incidence of femoral complications in univariate analysis, while age maintained this significant relationship in multivariate analysis (P < .001). There was a trend toward increased complication rate in patients receiving a short stem with full profile taper (1.27%, P = .0539). CONCLUSION: Despite an overall low rate of femoral complications after direct anterior total hip arthroplasty, the risk is increased in elderly patients and females. Furthermore, femoral stem design may portend an elevated risk of these complications.

Lateral Unicompartmental Knee Arthroplasty Utilizing a Modified Surgical Technique and Specifically Adapted Fixed-Bearing Implant.

BACKGROUND: Treatment of isolated lateral compartment arthritic disease with partial knee arthroplasty remains underutilized in comparison to medial unicompartmental arthroplasty. This study examines the survival and outcome of lateral unicompartmental arthroplasty utilizing the first implant specifically developed for the lateral compartment. MATERIALS AND METHODS: A retrospective review was performed to detect lateral unicompartmental arthroplasty procedures performed in our practice between January 2013 and May 2016. Patients indicated for surgery met specific preoperative clinical and radiographic criteria confirming lateral compartment arthritic disease with a correctable deformity, intact full-thickness medial cartilage, competent anterior cruciate ligament, and minimal disease in the patellofemoral compartment. A single implant design was used in all cases which consisted of a fixed-bearing tibial component specifically adapted to lateral compartment anatomy. Unicompartmental arthroplasty surgical technique was adjusted to attempt to recreate lateral compartment kinematics. RESULTS: Fifty-two consecutive patients (56 knees) with lateral unicompartmental arthroplasty procedures meeting minimum two-year follow up were included in the study. Thirty-nine patients were female, and 93% of cases were performed for treatment of osteoarthritis. At a mean follow up of nearly three years, Knee Society clinical and functional scores improved postoperatively by a mean difference of 41 and 21, respectively. There were two reoperations, one medial unicompartmental arthroplasty for osteoarthritis progression and a superficial debridement for a non-healing wound. Thus, failure of lateral unicondylar knee arthroplasty (UKA) was less than 2% in this study. There were no other component revisions, radiographic evidence of loosening, or clinical failures. CONCLUSIONS: At early follow up, lateral unicompartmental arthroplasty using a modified surgical technique and an implant specifically designed for the lateral compartment is a reliable treatment for isolated lateral femorotibial arthritis when meeting defined indications.

Reduced Thigh Pain with Short Femoral Stem Design Following Direct Anterior Primary Total Hip Arthroplasty.

BACKGROUND: Thigh pain is a variably reported symptom in the postoperative period following primary total hip arthroplasty (THA) with a well-fixed cementless femoral implant. While research has identified stem size, stem alignment, and differences in modulus of elasticity between implant and host bone as potential sources of thigh pain, only one study has specifically examined the impact of variation in implant design within a single femoral stem design. The purpose of this work was to determine whether there were differences in the pain experienced by patients treated with two design variants of a femoral stem during direct anterior THA. MATERIALS AND METHODS: Patients undergoing primary direct anterior THA at a single center between 2011-2015 were included in the study. Those patients suffering extensive comorbidities and postoperative complications were excluded from analysis. Study subjects completed a pain drawing and scale questionnaire for the operative hip at least one year following surgery. A cementless, single-taper wedge, titanium femoral component design available in short- and standard-length variations was used in all cases. Pain outcomes were compared between these two femoral stem options. RESULTS: A total of 1347 patients (1536 THA) met inclusion criteria for the study and surveys were returned for 820 of these THAs. Demographic data and UCLA activity scores were similar between cohorts of patients receiving the short- and standard-length components. The most common locations of pain reported were in the lower back and trochanteric region, 28% and 24% respectively. Patients in the short-length cohort reported a significantly lower incidence of pain in the anterior thigh as compared to the standard-length cohort, 12% versus 19% respectively [p=0.007]. There was no difference in the number of patients experiencing moderate to severe intensity of anterior thigh pain between these two groups, 3% versus 5% respectively [p=0.36]. No other statistically significant differences were found in the incidence of pain in the lower back, buttock, groin, trochanter, lateral thigh, or posterior thigh regions between the two cohorts. CONCLUSION: While the lower back and trochanteric region may be the most frequent areas of pain experienced in patients at one-year or more postoperative from direct anterior THA, a significantly higher incidence of anterior thigh pain is found in those patients treated with a standard-length stem design as compared to the short design. This finding may be due to contact between the tip of the distal stem with the femoral diaphysis as has been theorized in previous research, which is circumvented with the short design variant.

"Thicker" Polyethylene Bearings Are Not Associated With Higher Failure Rates in Primary Total Knee Arthroplasty.

BACKGROUND: Despite improvements in polyethylene bearing surface properties, only 1 previous study has examined the results of larger thickness bearings. The purpose of this study was to determine whether polyethylene thickness influenced patient outcomes and implant survival following modular total knee arthroplasty. METHODS: A retrospective review was performed of patients undergoing primary total knee arthroplasty from 2003 to 2014 in a single practice database. Patients were separated into "thin" and "thick" polyethylene groups based on manufacturer polyethylene bearing sizes of 14 mm or less compared to those greater than 14 mm, respectively. Patient clinical outcomes, need for revision surgery, and overall implant survival rates were evaluated. RESULTS: A total of 6698 primary knee arthroplasties were included, and a thin bearing was used in 96.5% of these cases. Preoperatively, patients with a thick bearing had significantly lower Knee Society clinical scores (P < .01), a trend toward lower functional scores (P = .06), and more significant coronal plane deformity. Postoperatively, patients with thick bearings exhibited better Knee Society clinical and pain scores as well as similar functional scores and University of California at Los Angeles activity scores. The overall reoperation rate and 10-year survivorship free of revision were similar between thick and thin bearings (1.7% vs 2.3%; 98.2% vs 96.1%). Patients with thin bearings were twice as likely to require a manipulation under anesthesia postoperatively (P = .02), while there were no failures in the thick bearing group due to aseptic loosening or instability. CONCLUSION: Patients with thick polyethylene bearings performed similarly or better in multiple clinical outcomes and survivorship compared to those with thin bearings.

Medial Mobile-Bearing Unicompartmental Knee Arthroplasty in Young Patients Aged Less Than or Equal to 50 Years.

BACKGROUND: Contemporary research has shown medial mobile-bearing unicompartmental knee arthroplasty to be an effective treatment in patients younger than 60 years; however, only one other study has specifically investigated unicompartmental arthroplasty outcomes in patients 50 years or younger. The purpose of this study was to determine the clinical outcomes and survivorship of medial mobile-bearing unicompartmental arthroplasty in this younger patient population. METHODS: A retrospective review of patients undergoing primary unicompartmental knee arthroplasty using the Oxford partial knee from 2003 to 2014 in a single practice database was performed. Patients were included in the study if they were 50 years of age or younger with a primary diagnosis of anteromedial osteoarthritis and minimum clinical follow-up of 2 years. Patient clinical outcomes, function, and need for revision surgery were assessed. RESULTS: The study included 340 knees. Average patient age was 46.5 years, and the mean follow-up was 6.1 years. Patients demonstrated significant improvements (P < .05) in range of motion (114.5 v 116.9), University of California Los Angeles activity score (4.4 vs 5.6), Knee Society clinical (37.3 vs 86.5) and functional scores (58.8 v 79.8). Overall, 20 patients required reoperation, and the predicted survival rate was 96% at 6 years and 86% at 10 years. Aseptic loosening occurred in 7 patients at an average of 5.6 years postoperatively, while 4 patients required conversion to total knee arthroplasty because of arthritic progression at a mean time of 6.6 years. There were no revision procedures required due to polyethylene liner wear or breakage. CONCLUSION: Medial mobile-bearing unicompartmental arthroplasty should be considered as a treatment option in patients younger than 50 years of age suffering from anteromedial osteoarthritis of the knee.

Lung cells support osteosarcoma cell migration and survival.

BACKGROUND: Osteosarcoma (OS) is the most common primary bone tumor, with a propensity to metastasize to the lungs. Five-year survival for metastatic OS is below 30%, and has not improved for several decades despite the introduction of multi-agent chemotherapy. Understanding OS cell migration to the lungs requires an evaluation of the lung microenvironment. Here we utilized an in vitro lung cell and OS cell co-culture model to explore the interactions between OS and lung cells, hypothesizing that lung cells would promote OS cell migration and survival. The impact of a novel anti-OS chemotherapy on OS migration and survival in the lung microenvironment was also examined. METHODS: Three human OS cell lines (SJSA-1, Saos-2, U-2) and two human lung cell lines (HULEC-5a, MRC-5) were cultured according to American Type Culture Collection recommendations. Human lung cell lines were cultured in growth medium for 72 h to create conditioned media. OS proliferation was evaluated in lung co-culture and conditioned media microenvironment, with a murine fibroblast cell line (NIH-3 T3) in fresh growth medium as controls. Migration and invasion were measured using a real-time cell analysis system. Real-time PCR was utilized to probe for Aldehyde Dehydrogenase (ALDH1) expression. Osteosarcoma cells were also transduced with a lentivirus encoding for GFP to permit morphologic analysis with fluorescence microscopy. The anti-OS efficacy of Disulfiram, an ALDH-inhibitor previously shown to inhibit OS cell proliferation and metastasis in vitro, was evaluated in each microenvironment. RESULTS: Lung-cell conditioned medium promoted osteosarcoma cell migration, with a significantly higher attractive effect on all three osteosarcoma cell lines compared to basic growth medium, 10% serum containing medium, and NIH-3 T3 conditioned medium (p <0.05). Lung cell conditioned medium induced cell morphologic changes, as demonstrated with GFP-labeled cells. OS cells cultured in lung cell conditioned medium had increased alkaline phosphatase staining. CONCLUSIONS: Lung endothelial HULEC-5a cells are attractants for OS cell migration, proliferation, and survival. The SJSA-1 osteosarcoma cell line demonstrated greater metastatic potential than Saos-2 and U-2 cells. ALDH appears to be involved in the interaction between lung and OS cells, and ALP may be a valuable biomarker for monitoring functional OS changes during metastasis.

Chick embryo extract demethylates tumor suppressor genes in osteosarcoma cells.

BACKGROUND: Epigenetics is the study of changes in gene expression or cellular phenotype caused by mechanisms other than changes in the underlying DNA sequence. It is widely accepted that cancer has genetic and epigenetic origins. The idea of epigenetic reprogramming of cancer cells by an embryonic microenvironment possesses potential interest from the prospect of both basic science and potential therapeutic strategies. Chick embryo extract (CEE) has been used for the successful expansion of many specific stem cells and has demonstrated the ability to facilitate DNA demethylation. QUESTIONS/PURPOSES: The current study was conducted to compare the status of DNA methylation in highly metastatic and less metastatic osteosarcoma cells and to investigate whether CEE may affect the epigenetic regulation of tumor suppressor genes and thus change the metastatic phenotypes of highly metastatic osteosarcoma cells. METHODS: K7M2 murine OS cells were treated with CEE to determine its potential effect on DNA methylation, cell apoptosis, and invasion capacity. RESULTS: Our current results suggest that the methylation status of tumor suppressor genes (p16, p53, and E-cadherin) is significantly greater in highly metastatic mouse ostoesarcoma K7M2 cells in comparison with less metastatic mouse osteosarcoma K12 cells. CEE treatment of K7M2 cells caused demethylation of p16, p53, and E-cadherin genes, upregulated their expression, and resulted in the reversion of metastatic phenotypes in highly metastatic osteosarcoma cells. CONCLUSIONS: CEE may promote the reversion of metastatic phenotypes of osteosarcoma cells and can be a helpful tool to study osteosarcoma tumor reversion by epigenetic reprogramming. CLINICAL RELEVANCE: Demethylation of tumor suppressor genes in osteosarcoma may represent a novel strategy to diminish the metastatic potential of this neoplasm. Further studies, both in vitro and in vivo, are warranted to evaluate the clinical feasibility of this approach as an adjuvant to current therapy.

Efficacy and safety evaluation of HSD-1 inhibitor ABT-384 in Alzheimer's disease.

BACKGROUND: In this study we assessed increased cortisol in Alzheimer's disease (AD) patients. The selective 11-ß-hydroxysteroid dehydrogenase type 1 (HSD-1) inhibitor ABT-384 blocked regeneration of active cortisol and this tests the hypothesis that intracellular hypercortisolism contributes to cognitive impairment. METHODS: In this double-blind, placebo- and active-controlled phase II study we examine the efficacy and safety of ABT-384 given 10 mg or 50 mg once daily, donepezil 10 mg once daily, or placebo for 12 weeks in subjects with mild-to-moderate AD. The primary efficacy end point was the change from baseline to final evaluation on the 13-item Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-Cog) total score. RESULTS: The study was terminated for futility after randomization of 267 subjects. ABT-384 did not improve ADAS-Cog scores or any secondary end point; however, donepezil significantly improved both cognition and functional end points. Overall incidence of adverse events was similar among treatment groups. CONCLUSION: ABT-384, when tested at doses associated with complete brain HSD-1 inhibition, did not produce symptomatic improvement in AD.

The rapid recovery study: Cyclobenzaprine's effect on recovery following joint arthroplasty.

Introduction: Skeletal muscle relaxants have previously not been examined in multimodal anesthesia regimens following joint arthroplasty. We sought to evaluate cyclobenzaprine's effect on postoperative opioid consumption as well as surgical recovery following joint arthroplasty. Materials and methods: In this retrospective cohort study, 471 patients undergoing 554 joint arthroplasty procedures were evaluated. Patients were divided into cohorts who did and did not receive cyclobenzaprine postoperatively, and postoperative opioid consumption and functional recovery measures were recorded in each cohort. Results: In the unadjusted model, the cyclobenzaprine cohort experienced a 1.11 increase in pain scores on postoperative day zero (95% CI (0.60, 1.62), p < 0.0001). After adjusting for age, sex, BMI, CCI, perioperative MME, laterality, procedure, anesthesia, pre-op opioid use, pre-operative other controlled substance uses and pre-op benzodiazepine use, the cyclobenzaprine cohort's pain scores were 1.08 units higher at rest (95% CI (0.59, 1.56), p < 0.0001) and 1.25 units higher with activity on postoperative-day-zero (95% CI (0.78, 1.72), p < 0.0001). Both cohorts experienced statistically insignificantly different changes in mobility scores between postoperative day zero and postoperative day one, range of motion at 6 and 12 weeks, and readmission in <90 days. Postoperative morphine milliequivalents were insignificantly different between cohorts after controlling for pain in all models (base model mean ratio: 1.06, 95% CI (0.87,1.29), p = 0.5599) (Full model mean ratio: 1.09, 95% CI (0.91,1.30), p = 0.3608). Conclusions: Cyclobenzaprine shows utility in a multimodal anesthetic approach after joint arthroplasty in patients with higher baseline pain.

Umbilical cord blood-derived very small embryonic like stem cells (VSELs) as a source of pluripotent stem cells for regenerative medicine.

Umbilical cord blood-derived very small embryonic-like stem cells (UCB-VSELs) are the most primitive stem cells circulating in fetal peripheral blood. These very rare cells slightly smaller than red blood cells i) become mobilized during delivery, ii) are enriched in fraction of CD133+ Lin-CD45- cells iii) express markers of pluripotent stem cells (e.g., Oct4, Nanog, and SSEA-4) and iv) display a distinct morphology characterized by a high nuclear/ cytoplasmic ratio and undifferentiated chromatin. We envision that VSELs are released into neonatal peripheral blood as a migrating population of stem cells involved in regeneration of tissues that become damaged in the process of delivery. They may also be responsible for the occurrence of fetal-maternal chimerism. Our most recent data suggest that UCB-VSELs exhibit some characteristics of long-term repopulating hematopoietic stem cells (LT-HSCs). We propose that UCB-VSELs may eventually be employed as a source of pluripotent stem cells in regenerative medicine.

microRNA 184 regulates expression of NFAT1 in umbilical cord blood CD4+ T cells.

The reduced expression of nuclear factor of activated T cells-1 (NFAT1) protein in umbilical cord blood (UCB)-derived CD4+ T cells and the corresponding reduction in inflammatory cytokine secretion after stimulation in part underlies their phenotypic differences from adult blood (AB) CD4+ T cells. This muted response may contribute to the lower incidence and severity of high-grade acute graft-versus-host disease (aGVHD) exhibited by UCB grafts. Here we provide evidence that a specific microRNA, miR-184, inhibits NFAT1 protein expression elicited by UCB CD4+ T cells. Endogenous expression of miR-184 in UCB is 58.4-fold higher compared with AB CD4+ T cells, and miR-184 blocks production of NFAT1 protein through its complementary target sequence on the NFATc2 mRNA without transcript degradation. Furthermore, its negative effects on NFAT1 protein and downstream interleukin-2 (IL-2) transcription are reversed through antisense blocking in UCB and can be replicated via exogenous transfection of precursor miR-184 into AB CD4+ T cells. Our findings reveal a previously uncharacterized role for miR-184 in UCB CD4+ T cells and a novel function for microRNA in the early adaptive immune response.

A double-blind, randomized, placebo-controlled study of the dopamine D3 receptor antagonist ABT-925 in patients with acute schizophrenia.

There is substantial preclinical and clinical evidence to suggest a potential role for the dopamine D3 receptor in the treatment of schizophrenia. ABT-925 is a selective dopamine D3 receptor antagonist with an approximately 100-fold higher in vitro affinity for dopamine D3 versus D2 receptors. This double-blind, randomized, placebo-controlled, escalating-dose, parallel-group study assessed the efficacy and safety of ABT-925 in the treatment of patients with acute exacerbation of schizophrenia. One hundred fifty-five patients were assessed over a 6-week double-blind treatment period (placebo: n = 48; ABT-925 50 mg once daily [QD]: n = 53; ABT-925 150 mg QD: n = 54). The primary efficacy measure was mean change from baseline to final evaluation on the Positive and Negative Syndrome Scale total score. Secondary measures of efficacy and pharmacokinetic parameters were also assessed. Safety assessments included adverse event monitoring, laboratory tests, vital signs, movement rating scales, and electrocardiogram measures. No statistically significant treatment effect was observed with ABT-925 50 mg QD or 150 mg QD compared with placebo on primary or secondary efficacy end points. Pharmacokinetic parameter estimates increased with dose in a linear fashion. ABT-925 50 mg QD and 150 mg QD were generally well tolerated, with adverse event profiles similar to that of placebo. Findings from a concurrent positron emission tomography study among healthy volunteers suggest that the ABT-925 doses used in this study may not have been sufficient to adequately occupy D3 receptors, thereby underscoring the importance of pharmacodynamic markers, such as PET, in determining appropriate compound doses before embarking on studies in a target population.

Model-based tracking of the hip: implications for novel analyses of hip pathology.

This study investigated the efficacy of a combined high-speed, biplane radiography and model-based tracking technique to study hip joint kinematics and arthrokinematics. Comparing model-based tracking to the gold standard of radiostereometric analysis using implanted metal beads, joint translation was measured with a bias of 0.2 mm and a precision of 0.3 mm, whereas joint rotation was measured with a bias of 0.2° and a precision of 0.8°. A novel measure of hip arthrokinematics characterizing the region of closest contact in the anterosuperior acetabulum was measured with a bias of 0.9% and a precision of 2.5%. Model-based tracking of the hip thus provides the opportunity to noninvasively study hip pathologic conditions such as osteoarthritis and femoroacetabular impingement with great accuracy.

Medial Osteoarthritis in an ACL-Deficient Knee: A Critical Analysis Review.

¼: In anterior cruciate ligament (ACL)-deficient knees, treatment of medial compartment osteoarthritis (OA) that is refractory to nonoperative modalities is a controversial subject. ¼: Currently available treatment options include unicompartmental knee arthroplasty (UKA) with or without ACL reconstruction (ACLR), high tibial osteotomy (HTO) with or without ACLR, and total knee arthroplasty (TKA). ¼: Each treatment option has its own risks and benefits, and the evidence that is reviewed in this article suggests that patient characteristics guide treatment selection. ¼: Future high-quality prospective studies that directly compare all 3 of the modalities are necessary to determine the best treatment option for different patient populations.

Umbilical cord blood-selected CD133(+) cells exhibit vasculogenic functionality in vitro and in vivo.

BACKGROUND AIMS: Current clinical trials utilize non-selected bone marrow (BM) mononuclear cells (MNC) to augment vasculo genesis within ischemic vascular beds. Recent reports have identified a diminished number and function of hemat-opoietic stem cells (HSC) from aged and diseased patients. Umbilical cord blood (UCB) provides a potential robust allo-geneic source of HSC for therapeutic vasculogenesis. METHODS: MNC and magnetically isolated CD133(+) cells were assessed for viability (trypan blue) and surface phenotype (flow cytometry). To test in vivo functionality of the cells, NOD/SCID mice underwent ligation of the right femoral artery followed immediately by cell injection. Blood flow recovery, necrosis, BM engraftment of human cells and histologic capillary density were determined. Cells were tested for potential mechanisms mediating the in vivo effects, including migration, cytokine secretion and angiogenic augmentation (Matrigel assays). RESULTS: Surface expression analysis showed CD31 (PECAM) expression was greatly increased in UCB CD133(+) cells compared with BM MNC. At 28 days, perfusion ratios were highest in animals receiving UCB CD133(+) cells, while animals receiving BM CD133(+) cells and BM MNC demonstrated perfusion ratios statistically higher than in animals treated with cytokine media alone. Animals receiving CD133(+) cells showed a statistically higher capillary density, reduced severe digit necrosis and increased engraftment in the BM than animals treated with unselected BM MNC. In vitro studies showed equivalent migration to stromal-derived factor-1 (SDF-1), increased production of tumor necrosis factor alpha (TNF-alpha) and increased branch points with the co-incubation of CD133(+) cells with human umbilical vein endothelial cells (HUVEC) in the Matrigel angiogenesis assay. CONCLUSIONS: Taken together, UCB CD133(+) cells exhibit robust vasculogenic functionality compared with BM MNC in response to ischemia.

Outcome Reporting Patterns in Total Hip Arthroplasty: A Systematic Review of Randomized Clinical Trials.

BACKGROUND: There has been a shift toward using patient-reported outcome measures (PROMs) to capture functional improvement and patient satisfaction after total hip arthroplasty (THA). Because there is no standard measure or set of measures, variability in reporting patterns makes comparison across studies difficult. METHODS: We performed a review of the literature using the keywords "total hip arthroplasty" and "total hip replacement" to electronically search PubMed, using the date range August 1, 2014, to August 1, 2019. Randomized clinical trials (RCTs) that were published in 12 high-impact journals were analyzed. RESULTS: One hundred and fifty-nine RCTs were included. The most common topic of investigation was hip implant design and materials, followed by the effect of different hip approaches on patient outcomes. The follow-up period was classified as short-term (<2 years), mid-term (2 to 10 years), or long-term (>10 years). Only 6% of the RCTs reported long-term outcomes. The comprehensiveness of studies was determined on the basis of how many of the 7 following outcome domains were assessed: subjective hip function (PROMs), objective outcome measures (examination findings, laboratory values, etc.), imaging analysis, survivorship, patient satisfaction, pain assessment, and postoperative complications. Subjective hip function and imaging findings were the most commonly reported outcome domains, while implant survivorship and patient satisfaction were the least frequently reported. There was substantial variation in outcome reporting, with 35 unique PROMs utilized to assess subjective hip function. Although the Harris hip score was the most commonly used joint-specific PROM, it was only reported in 42% of the studies. None of the RCTs reported results in all 7 outcome domains, and 13.8% of studies reported results in only 1 outcome domain. CONCLUSIONS: There is substantial variability and a lack of comprehensiveness in outcome measures used to report results in THA clinical trials, making it nearly impossible to perform cross-study comparisons. CLINICAL RELEVANCE: There is an immediate need for the establishment of a standardized set of measures to allow comparison of outcomes across studies.

Outcome reporting patterns in total knee arthroplasty: A systematic review.

BACKGROUND: Total knee arthroplasty (TKA) is one of the most effective ways to treat end-stage painful conditions of the knee. However, non-standardized reporting patterns can make quantitative analysis of patient outcomes difficult. METHODS: A systematic review of the literature was performed using keywords "total knee arthroplasty" and "total knee replacement." Randomized controlled trials (RCTs) meeting the inclusion criteria were sorted and reviewed. Type of study, outcome measures used to report their results, and the actual results were recorded. Quantitative analysis was performed. RESULTS: A total of 233 RCTs were included. There was significant variability in the reporting of short term and long term outcomes in total knee arthroplasty. The most common treatment domains in order of decreasing frequency were objective knee function, subjective knee function, perioperative complications, and pain. Range of motion was the most common outcome metric reported in all the RCTs and also was the most common metric used to assess objective knee function. The most common patient reported outcome measure used to assess postoperative function was the Knee Society Score followed by Knee Injury and Osteoarthritis Outcome Score. The Visual Analog Scale was the most common measurement tool used to assess postoperative pain. Most studies assessed patient outcomes in three treatment domains. None reported outcomes in all seven domains. CONCLUSION: There is significant variability in outcome reporting patterns in TKA literature. Most studies do not track outcomes comprehensively, with a significant minority of the RCTs tracking outcomes in only one treatment domain.

Medial Unicompartmental Knee Arthroplasty for the Treatment of Focal Femoral Osteonecrosis.

BACKGROUND: Previous research has indicated that unicompartmental arthroplasty may be an effective treatment for focal osteonecrosis in the knee; however, these reports have been composed of small patient cohorts and without characterization of the osteonecrotic lesions. Therefore, the purpose of this study was to investigate the effectiveness of unicompartmental arthroplasty for the treatment of focal osteonecrosis within the medial femoral condyle including an assessment of lesion size. METHODS: A consecutive series of >5,000 unicompartmental knee arthroplasties performed at a single institution was retrospectively reviewed to identify cases of medial femoral condyle osteonecrosis with a minimum 2-year follow-up. Lesion size was classified according to the ratio of lesion width to condylar width, as well as lesion depth relative to condylar depth. Patient-reported outcome measures and need for a revision procedure were studied. RESULTS: Sixty-four patients (32 males, 32 females; 65 knees) with a mean age of 64 years were included. The mean patient follow-up was 5.3 years (range, 2 to 12 years). The mean ratio of lesion width to condylar width was 64%, the mean lesion depth was 1.11 cm, and 82% of cases demonstrated subchondral collapse. At the time of the latest follow-up, patients demonstrated substantial improvements in the pain, function, and clinical components of the Knee Society Score, by 36, 25, and 51, respectively. Four patients (6%) required a revision, of which only 1 was for aseptic loosening of the femoral component. CONCLUSIONS: Unicompartmental arthroplasty is an effective treatment for advanced-stage focal osteonecrosis of the medial femoral condyle. Loss of component fixation to the femoral condyle did not appear to be a substantial concern because there was only 1 femoral failure as a result of aseptic loosening, despite lesions affecting a significant portion of the femoral condyle. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Polyethylene liner dislocation of fixed-bearing medial oxinium unicompartmental arthroplasty with severe metallosis.

The case of an atraumatic dislocation of a fixed bearing in a medial unicompartmental arthroplasty with an oxinium femoral component is presented. A review of the literature pertaining to knee arthroplasty locking mechanisms is discussed. Potential modes of locking mechanisms failure are reviewed including the recognition of such failures in the clinical setting. This is the first report of a dislocated fixed-bearing medial oxinium unicompartmental arthroplasty and consequent metal arthrogram.