Aims. Intra-articular administration of antibiotics during primary total knee arthroplasty (TKA) may represent a safe, cost-effective strategy to reduce the risk of acute periprosthetic joint infection (PJI). Vancomycin with an aminoglycoside provides antimicrobial cover for most organisms isolated from acute PJI after TKA. However, the intra-articular doses required to achieve sustained therapeutic intra-articular levels while remaining below toxic serum levels is unknown. The purpose of this study is to determine the intra-articular and serum levels of vancomycin and tobramycin over the first 24 hours postoperatively after intra-articular administration in primary cementless TKA. Methods. A prospective cohort study was performed. Patients were excluded if they had poor renal function, known allergic reaction to vancomycin or tobramycin, received intravenous vancomycin, or were scheduled for same-day discharge. All patients received 600 mg tobramycin and 1 g of vancomycin powder suspended in 25 cc of normal saline and injected into the joint after closure of the arthrotomy. Serum from peripheral venous blood and drain fluid samples were collected at one, four, and 24 hours postoperatively. All concentrations are reported in µg per ml. Results. A total of 22 patients were included in final analysis. At one, four, and 24 hours postoperatively, mean (95% confidence interval (CI)) serum concentrations were 2.4 (0.7 to 4.1), 5.0 (3.1 to 6.9), and 4.8 (2.8 to 6.9) for vancomycin and 4.9 (3.4 to 6.3), 7.0 (5.8 to 8.2), and 1.3 (0.8 to 1.8) for tobramycin; intra-articular concentrations were 1,900.6 (1,492.5 to 2,308.8), 717.9 (485.5 to 950.3), and 162.2 (20.5 to 304.0) for vancomycin and 2,105.3 (1,389.9 to 2,820.6), 403.2 (266.6 to 539.7), and 98.8 (0 to 206.5) for tobramycin. Conclusion. Intra-articular administration of 1 g of vancomycin and 600 mg of tobramycin as a solution after closure of the arthrotomy in primary cementless TKA achieves therapeutic intra-articular concentrations over the first 24 hours postoperatively and does not reach sustained toxic levels in peripheral blood. Cite this article: Bone Joint J 2021;103-B(11):1702–1708

Aims. Hereditary haemochromatosis is a genetic disorder that is caused by several known mutations in the human homeostatic iron regulator protein (HFE) gene. Abnormal accumulation of iron causes a joint disease that resembles osteoarthritis (OA), but appears at a relatively younger age and is accompanied by cirrhosis, diabetes, and injury to other organs. Increased serum transferrin saturation and ferritin levels are known markers of haemochromatosis with high positive predictive values. Methods. We have retrospectively analyzed the iron studies of a cohort of 2,035 patients undergoing knee joint arthroplasty due to OA. Results. No patients had HFE gene C282Y, S65C, or H63D mutations testing. In total, 18 patients (2.96%) of the male cohort and 51 (3.58%) of the female cohort had pathologically increased ferritin levels that may be indicative of haemochromatosis. Seven patients (0.34%) had serum transferrin saturation above 45%. Conclusion. The awareness for the diagnosis of this disorder in Orthopaedics is low and needs improvement. Osteoarthritic patients undergoing knee arthroplasty should be routinely screened for haemochromatosis by iron studies and referred to genetic testing when needed. Level of evidence: Level III - Retrospective cohort study. Cite this article: Bone Jt Open 2021;2(12):1062–1066

Aims. This study compared the cobalt and chromium serum ion concentration of patients treated with two different metal-on-metal (MoM) hinged total knee arthroplasty (TKA) systems, as well as a titanium nitride (TiN)-coated variant. Methods. A total of 63 patients (65 implants) were treated using either a MoM-coated (n = 29) or TiN-coated (n = 7) hinged TKA (GenuX mobile bearing, MUTARS; Implantcast, Germany) versus the BPKS (Brehm, Germany) hinged TKA (n = 27), in which the weight placed on the MoM hinge is diffused through a polyethylene (PE) inlay, reducing the direct load on the MoM hinge. Serum cobalt and chromium ion concentrations were assessed after minimum follow-up of 12 months, as well as functional outcome and quality of life. Results. No differences in mean age (69 years, 40 to 86), mean age adapted Charlson Comorbidity Index (3.1 (SD 1.4)), mean BMI (29.2 kg/m. 2. (SD 5.8)), or number of other implants were observed between groups. Significant improvements in outcome scores and pain levels were achieved for all groups, and there was no difference in quality of life (12-Item Short-Form Health Survey questionnaire (SF-12)). Mean cobalt and chromium ion levels were significantly higher for the GenuX versus the BPKS hinged TKA (GenuX vs BPKS: cobalt: 16.3 vs 9.4 µg/l; chromium: 9.5 vs 5.2 µg/l). The TiN-coated implants did not appear to confer improvement in the metal ion levels. Metal ion concentrations above 7 µg/l were detected in 81%(29/36) of GenuX patients versus 41% (11/27) in the BPKS group. No GenuX patients had normal levels under 2 µg/l, versus 22% of BPKS patients. No significant reduction in outcome scores was observed regardless of the metal ion levels, whereas higher work-related activity was correlated with higher chromium concentrations. Conclusion. Hinged TKA, using MoM hinges, resulted in critically high cobalt and chromium ion concentrations. The BPKS hinged TKA showed significantly lower metal ion concentrations compared with the GenuX TKA. No benefits were observed using TiN coating. The different weightbearing mechanics might influence the wear of the component materials. Higher workloads and physical activity could influence chromium levels. Cite this article: Bone Joint J 2022;104-B(3):376–385

Aims. The aim of this study was to assess the effectiveness of perioperative essential amino acid (EAA) supplementation to prevent rectus femoris muscle atrophy and facilitate early recovery of function after total knee arthroplasty (TKA). Methods. The study involved 60 patients who underwent unilateral TKA for primary knee osteo-arthritis (OA). This was a double-blind, placebo-controlled, randomized control trial with patients randomly allocated to two groups, 30 patients each: the essential amino acid supplementation (9 g daily) and placebo (lactose powder, 9 g daily) groups. Supplementation and placebo were provided from one week before to two weeks after surgery. The area of the rectus femoris muscle were measured by ultrasound imaging one month before surgery and one, two, three, and four weeks postoperatively. The serum albumin level, a visual analogue knee pain score, and mobility were also measured at each time point. The time to recovery of activities of daily living (ADLs) was recorded. Postoperative nutrition and physiotherapy were identical in both groups. Results. The mean relative change from baseline was as follows for the amino acid group: 116% in rectus femoris muscle area (71% to 206%); 95% in serum albumin (80% to 115%) and 39% in VAS pain (0% to 100%) at four weeks after surgery. These values in the placebo group were: 97% in muscle area (68 to 155); 89% in serum albumin (71% to 100%) and 56% in VAS pain four weeks after surgery (0% to 100%). All changes were statistically significant (p < 0.05). The mean time to recovery of ADLs was shorter in the amino acid group compared with the placebo group (p = 0.005). Conclusion. Perioperative essential amino acid supplementation prevents rectus femoris muscle atrophy and accelerates early functional recovery after TKA. Cite this article: Bone Joint J 2020;102-B(6 Supple A):10–18

Introduction. Mechanical or corrosive failure of total knee arthroplasties (TKAs) is difficult to diagnose with current laboratory and radiographic analyses. As such, the goal of this study was to determine the mean blood concentration of cobalt, chromium, and titanium in a series of revision TKAs with mechanical implant failure and evaluate whether they facilitated identification of the underlying TKA failure mechanism. Methods. Serum cobalt, chromium, and titanium levels and synovial fluid characteristics were evaluated in 12 patients (13 aseptic revision TKAs) who underwent revision TKA between 2000 and 2020 at a single academic institution for mechanical implant failure or corrosion. Seventy-five percent were re-revisions of previously revised TKAs. Mean time to revision was 6 years. Modular metallic junctions were present in 100%. Twenty-five percent did not have another in situ total joint arthroplasty, and the remaining patients did not have a metal-on-metal articulation that could lead to elevation in serum metal ion levels. Mean follow-up after the revision TKA was 8 months. Results. Mean serum cobalt, chromium, and titanium concentrations were 11 ng/mL, 6 ng/mL, and 3 ng/mL, respectively. Serum metal ion levels facilitated failure mechanism identification in 75%, which included modular junction failure (6 cases), constraint locking mechanism failure (3 cases), corrosion of modular metallic interfaces (2 cases), and implant fracture (1 case). Arthrocentesis was performed in 75%. Mean synovial fluid cell count was 950 cells/mcL. Monocytes were the predominant mean cell type (41%), followed by neutrophils (35%), and lymphocytes (22%). Conclusion. Serum metal ion assessment should be considered when the etiology of painful primary or revision TKAs, particularly those with modular metallic junctions, remains elusive after routine evaluation

Abstract. Introduction. The postoperative inflammatory response may be implicated in the aetiology of patient dissatisfaction following Total Knee Arthroplasty. Robotic-arm assisted TKA has been associated with reduced bone and soft tissue trauma. The objective of this Randomised Controlled Trial was to compare the inflammatory response in conventional Jig-based versus robotic arm-assisted TKA and examine the relationship with patient reported outcome measures and functional outcomes. Methodology. 30 patients with knee osteoarthritis were randomised to either conventional or robotic-arm assisted TKA. Blood samples were collected for up to 28 days post-operatively and intraarticular drain samples at 6 and 24 hours, to ascertain the systemic and local inflammatory responses. The Spearman's correlation was utilised to evaluate the relationship with PROMs and functional outcomes. Results. Reduced IL-6 drain fluid levels were noted at 6 hours [798.54 vs. 5699.2, p=0.026] and 24 hours and IL-8 at 6 hours. Patients in the robotic group had lower pain scores on post-operative day 1, 2 and 7. PROM scores were comparable at 2 years. Statistically significant correlations were evident between all serum markers except IL-1b on the 7th postoperative day and self-reported pain; between drain IL-8 levels and self-reported pain; between drain IL-6, IL-8 and TNF-a levels (6-hours) and knee flexion and extension. Conclusion. Robotic-arm assisted TKA was associated with a reduced postoperative local and systemic inflammatory responses. A moderate correlation with self-reported pain, knee flexion and extension was also demonstrated. Longer-term data and further validation on a larger scale, will be key to developing the optimal TKA procedure

Aims. The primary aim of this study was to compare the postoperative systemic inflammatory response in conventional jig-based total knee arthroplasty (conventional TKA) versus robotic-arm assisted total knee arthroplasty (robotic TKA). Secondary aims were to compare the macroscopic soft tissue injury, femoral and tibial bone trauma, localized thermal response, and the accuracy of component positioning between the two treatment groups. Methods. This prospective randomized controlled trial included 30 patients with osteoarthritis of the knee undergoing conventional TKA versus robotic TKA. Predefined serum markers of inflammation and localized knee temperature were collected preoperatively and postoperatively at six hours, day 1, day 2, day 7, and day 28 following TKA. Blinded observers used the Macroscopic Soft Tissue Injury (MASTI) classification system to grade intraoperative periarticular soft tissue injury and bone trauma. Plain radiographs were used to assess the accuracy of achieving the planned postioning of the components in both groups. Results. Patients undergoing conventional TKA and robotic TKA had comparable changes in the postoperative systemic inflammatory and localized thermal response at six hours, day 1, day 2, and day 28 after surgery. Robotic TKA had significantly reduced levels of interleukin-6 (p < 0.001), tumour necrosis factor-α (p = 0.021), ESR (p = 0.001), CRP (p = 0.004), lactate dehydrogenase (p = 0.007), and creatine kinase (p = 0.004) at day 7 after surgery compared with conventional TKA. Robotic TKA was associated with significantly improved preservation of the periarticular soft tissue envelope (p < 0.001), and reduced femoral (p = 0.012) and tibial (p = 0.023) bone trauma compared with conventional TKA. Robotic TKA significantly improved the accuracy of achieving the planned limb alignment (p < 0.001), femoral component positioning (p < 0.001), and tibial component positioning (p < 0.001) compared with conventional TKA. Conclusion. Robotic TKA was associated with a transient reduction in the early (day 7) postoperative inflammatory response but there was no difference in the immediate (< 48 hours) or late (day 28) postoperative systemic inflammatory response compared with conventional TKA. Robotic TKA was associated with decreased iatrogenic periarticular soft tissue injury, reduced femoral and tibial bone trauma, and improved accuracy of component positioning compared with conventional TKA. Cite this article: Bone Joint J 2021;103-B(1):113–122

Aims. The anterior cruciate ligament (ACL) is known to have a poor wound healing capacity, whereas other ligaments outside of the knee joint capsule such as the medial collateral ligament (MCL) apparently heal more easily. Plasmin has been identified as a major component in the synovial fluid that varies among patients. The aim of this study was to test whether plasmin, a component of synovial fluid, could be a main factor responsible for the poor wound healing capacity of the ACL. Methods. The effects of increasing concentrations of plasmin (0, 0.1, 1, 10, and 50 µg/ml) onto the wound closing speed (WCS) of primary ACL-derived ligamentocytes (ACL-LCs) were tested using wound scratch assay and time-lapse phase-contrast microscopy. Additionally, relative expression changes (quantitative PCR (qPCR)) of major LC-relevant genes and catabolic genes were investigated. The positive controls were 10% fetal calf serum (FCS) and platelet-derived growth factor (PDGF). Results. WCS did not differ significantly among no plasmin versus each of the tested concentrations (six donors). The positive controls with PDGF and with FCS differed significantly from the negative controls. However, we found a trend demonstrating that higher plasmin concentrations up-regulate the expression of matrix metalloproteinase 13 (MMP13), 3 (MMP3), and tenomodulin (TNMD). Conclusion. The clinical relevance of this study is the possibility that it is not solely the plasmin, but also additional factors in the synovial fluid of the knee, that may be responsible for the poor healing capacity of the ACL. Cite this article: Bone Joint Res 2020;9(9):543–553

Aims. Infection complicating primary total knee arthroplasty (TKA) is a common reason for revision surgery, hospital readmission, patient morbidity, and mortality. Increasing incidence of methicillin-resistant Staphylococcus aureus (MRSA) is a particular concern. The use of vancomycin as prophylactic agent alone or in combination with cephalosporin has not demonstrated lower periprosthetic joint infection (PJI) rates, partly due to timing and dosing of intravenous (IV) vancomycin administration, which have proven important factors in effectiveness. This is a retrospective review of a consecutive series of primary TKAs examining incidence of PJI, adverse reactions, and complications using IV versus intraosseous (IO) vancomycin at 30-day, 90-day, and one-year follow-up. Methods. A retrospective review of 1,060 patients who underwent TKA between May 2016 to July 2020 was performed. There were 572 patients in the IV group and 488 in the IO group, with minimal 30 days of follow-up. Patients were followed up at regularly scheduled intervals (two, six, and 12 weeks). No differences between groups for age, sex, BMI, or baseline comorbidities existed. The IV group received an IV dose of 15 mg/kg vancomycin given over an hour preceding skin incision. The IO group received a 500 mg dose of vancomycin mixed in 150 ml of normal saline, injected into proximal tibia after tourniquet inflation, before skin incision. All patients received an additional dose of first generation cephalosporin. Evaluation included preoperative and postoperative serum creatinine values, tourniquet time, and adverse reactions attributable to vancomycin. Results. Incidence of PJI with minimum 90-day follow-up was 1.4% (eight knees) in the IV group and 0.22% (one knee) in IO group (p = 0.047). This preliminary report demonstrated an reduction in the incidence of infection in TKA using IO vancomycin combined with a first-generation cephalosporin. While the study suffers from limitations of a retrospective, multi-surgeon investigation, early findings are encouraging. Conclusion. IO delivery of vancomycin after tourniquet inflation is a safe and effective alternative to IV administration, eliminating the logistical challenges of timely dosing. Cite this article: Bone Joint J 2021;103-B(6 Supple A):13–17

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The diagnosis of periprosthetic joint infection (PJI) can be challenging as the symptoms are similar to other conditions, and the markers used for diagnosis have limited sensitivity and specificity. Recent research has suggested using blood cell ratios, such as platelet-to-volume ratio (PVR) and platelet-to-lymphocyte ratio (PLR), to improve diagnostic accuracy. The aim of the study was to further validate the effectiveness of PVR and PLR in diagnosing PJI.

Introduction. The objectives of this study were to compare the systemic inflammatory reaction, localised thermal response and macroscopic soft tissue injury outcomes in conventional jig-based total knee arthroplasty (conventional TKA) versus robotic total knee arthroplasty (robotic TKA). Methods. This prospective randomised controlled trial included 30 patients with symptomatic knee osteoarthritis undergoing conventional TKA versus robotic TKA. Predefined serum markers of inflammation and localised knee temperature were collected preoperatively and postoperatively at 6 hours, day 1, day 2, day 7, and day 28 following TKA. Blinded observers used the Macroscopic Soft Tissue Injury (MASTI) classification system to grade intraoperative periarticular soft tissue injury and bone trauma. Plain radiographs were used to assess the accuracy of achieving the planned limb alignment and implant positioning in both treatment groups. Results. Conventional TKA and robotic TKA had comparable changes in the postoperative systemic inflammatory reaction and localised thermal response at 6 hours, day 1, day 2 and day 28 after surgery. Robotic TKA had reduced levels of interleukin-6 (p<0.001), tumour necrosis factor-α (p=0.021), erythrocyte sedimentation rate (p=0.001), C-reactive protein (p=0.004), and creatine kinase (p=0.004) at day 7 after surgery compared to conventional TKA. Robotic TKA was associated with improved intraoperative preservation of the periarticular soft tissue envelope (p<0.001) and reduced bone trauma (p=0.015) compared to conventional TKA. Robotic TKA improved accuracy of achieving the planned limb alignment (p<0.001), femoral component positioning (<0.001), and tibial component positioning (<0.001) compared to conventional TKA. Conclusion. Robotic TKA was associated with a transient reduction in the early (day 7) postoperative inflammatory response but there was no difference in the immediate (<48 hours) or late (day 28) postoperative systemic inflammatory responses compared to conventional TKA. Robotic TKA was associated with decreased iatrogenic periarticular soft tissue injury, reduced bone trauma and improved accuracy of implant positioning compared to conventional TKA

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Implantation of ultra-purified alginate (UPAL) gel is safe and effective in animal osteochondral defect models. This study aimed to examine the applicability of UPAL gel implantation to acellular therapy in humans with cartilage injury.

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Fungal periprosthetic joint infections (PJIs) are rare, but their diagnosis and treatment are highly challenging. The purpose of this study was to investigate the clinical outcomes of patients with fungal PJIs treated with two-stage exchange knee arthroplasty combined with prolonged antifungal therapy.

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The antidiabetic agent metformin inhibits fibrosis in various organs. This study aims to elucidate the effects of hyperglycaemia and metformin on knee joint capsule fibrosis in mice.

We investigated the role of ion release in the assessment of fixation of the implant after total knee replacement and hypothesised that ion monitoring could be a useful parameter in the diagnosis of prosthetic loosening. We enrolled 59 patients with unilateral procedures and measured their serum aluminium, titanium, chromium and cobalt ion levels, blinded to the clinical and radiological outcome which was considered to be the reference standard. The cut-off levels for detection of the ions were obtained by measuring the levels in 41 healthy blood donors who had no implants. Based on the clinical and radiological evaluation the patients were divided into two groups with either stable (n = 24) or loosened (n = 35) implants. A significant increase in the mean level of Cr ions was seen in the group with failed implants (p = 0.001). The diagnostic accuracy was 71% providing strong evidence of failure when the level of Cr ions exceeded the cut-off value. The possibility of distinguishing loosening from other causes of failure was demonstrated by the higher diagnostic accuracy of 83%, when considering only patients with failure attributable to loosening. Measurement of the serum level of Cr ions may be of value for detecting failure due to loosening when the diagnosis is in doubt. The other metal ions studies did not have any diagnostic value

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To map literature on prognostic factors related to outcomes of revision total knee arthroplasty (rTKA), to identify extensively studied factors and to guide future research into what domains need further exploration.

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Periprosthetic joint infection (PJI) occurs in approximately 1% to 2% of total knee arthroplasties (TKA) presenting multiple challenges, such as difficulty in diagnosis, technical complexity, and financial costs. Two-stage exchange is the gold standard for treating PJI but emerging evidence suggests 'two-in-one' single-stage revision as an alternative, delivering comparable outcomes, reduced morbidity, and cost-effectiveness. This study investigates five-year results of modified single-stage revision for treatment of PJI following TKA with bone loss.

Introduction. Hypoalbuminemia has previously been identified as an independent predictor of postoperative complications following total knee arthroplasty (TKA). Given the morbidity and financial burden associated with TKA complications, significant effort has gone into identifying patients at increased risk for perioperative complications. The American Society of Anesthesiologists (ASA) physical status score has been utilized for risk stratification of surgical patients for many years and is a measure of overall health. However, it is unclear how measures like albumin compare to the prognostic ability of this type of global health measure. This study aims to elucidate the utility of preoperative albumin compared with that of the ASA score in predicting complications following TKA. Methods. Patients undergoing TKA between 2005 and 2015 were identified using the American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) database. Patients were stratified based on preoperative hypoalbuminemia (<3.5 g/dL) and ASA score (≤ 2 vs. > 2). Multivariable regression analysis adjusted for age, sex, BMI, and smoking status was utilized to determine predictive potential of hypoalbuminemia and ASA score on each postoperative complication. Results. Of the 79,661 patients included in the cohort, 4.3% had preoperative hypoalbuminemia. Univariate regression analysis found significant predictive abilities of both serum albumin and ASA score on numerous postoperative complications, such as superficial infection, deep infection, MI, pneumonia, renal insufficiency, reintubation, transfusion, readmission, reoperation, and death. Interestingly, multivariable regression analysis demonstrated that hypoalbuminemia more robustly predicted postoperative deep infection than ASA. Discussion and Conclusion. Hypoalbuminemia and ASA each individually predict numerous postoperative complications following TKA. However, this study suggests that while ASA score more accurately predicts post-operative medical complications, hypoalbuminemia may be a more accurate predictor of periprosthetic infection following TKA. Ultimately, preoperative albumin should be incorporated in the pre-operative work-up routine to stratify patient risk, especially regarding postoperative infection

Introduction. Low serum Vitamin D (VitD) levels are often found in patients being investigated for Total Knee Arthroplasty (TKA). VitD deficiency is associated with poor pre/post-operative functional scores and higher rate of complications. Studies report VitD as an important modifiable risk factor to improve outcomes post TKA. Aim. Aim of our study was 1) To examine the trajectory of VitD in TKA patients over 2 weeks, which included VitD sufficient and deficient patients who were supplemented orally or intramuscularly (IM) for comparision. 2) To compare early (2weeks) functional recovery in VitD sufficient and deficient patients. Material & Methods. We prospectively enrolled patients undergoing primary TKA by a single surgeon. Based on preoperative VitD levels (25OH VitD ≥30 being sufficient or <30 ng/mL being deficient) and means of supplementation(none, IM or Oral Injection Arachitol, Cholecalciferol IP 6,00,000 IU), we formed three groups: Group A (VitD sufficient, no supplementation); Group B (VitD deficient, IM supplementation); and Group C (VitD deficient, Oral supplementation). Study was approved by ethics committee. All patients gave informed consent and underwent TKA by same surgeon with uniform intra/post-operative protocols. VitD deficiency was supplemented orally/IM on the morning of surgery based on their randomization sequence. VitD levels (ng/mL) and outcome parameters of Flexion (degrees) and Timed up-and-go (TUG) test in seconds were assessed preoperatively and postoperatively on Day 3 and 14. 60 patients (20 per group) were enrolled. Demographics of all three groups were comparable. Results. VitD:. Group A:. Mean preoperative level of 42.3, fell to mean 40.4 by Day 3 (p < 0.001), and further to mean 38.9 by Day 14 (p<0.001). 6 and 4 patients became VitD deficient by Day 3 and Day 14 respectively. Group B:. Mean preoperative level of 21.5 rose to 31.2 by Day 3 (p=0.06), and further to 36.9 by Day 14 (p=0.001). 7 and 11 patients became sufficient by Day 3 and Day 14 respectively. Group C:. Mean preoperative level of 20.2 rose to mean 69.9 by Day 3 (p<0.001) and to a mean of 67.2 by Day 14 (p < 0.001). 19 and 20 patients became sufficient by Day 3 and Day 14 respectively. Outcome. Flexion:. Preoperative Flexion in Groups A, B, C was 133, 129 & 125 respectively (p=0.5). Day 3 Flexion was 88, 84 & 83 (p=0.2); Day 14 Flexion was 99, 90 & 95 (p=0.013) respectively. Posthoc Schaffe test showed statistical significance (p<0.05) only between Group A (99) and Group B (90) at Day 14. This indicated better flexion achieved in VitD sufficient patients at 2 weeks than in deficient patients with IM supplementation. TUG Test. was 17.1, 14.1 & 14.7 preoperatively in Groups A, B, C (p=0.5); on Day 3, it was 52.5, 62.6 & 58.2 (p=0.07); on Day 14, it was 33, 38.8 & 37.8 (p=0.2) respectively. Day 3 TUG time was longest (62.6) in Group B and shortest (52.5) in Group A indicating that IM supplemented patients had poor function compared to sufficient group though without statistical significance (p=0.07) with numbers available. Conclusion. We found that VitD deficient patients can be rapidly supplemented on the morning of surgery. High dose oral VitD increased levels by Day 3, whereas IM VitD increased levels only by Day 14 which remained significantly lesser than oral group. Interestingly, about 25% of VitD sufficient patients who were not supplemented, became deficient postoperatively. Flexion achieved on Day 14 was significantly better with VitD sufficiency, compared to deficient patients treated with IM VitD. Significance. VitD deficiency can be rapidly corrected by high dose oral supplementation on the morning of surgery. Also, TKA can deplete VitD and can make VitD sufficient patients deficient as early as Day 3 post surgery. For figures, tables, or references, please contact authors directly

Objectives. The goal of this study was to determine whether intra-articular administration of the potentially anti-fibrotic agent decorin influences the expression of genes involved in the fibrotic cascade, and ultimately leads to less contracture, in an animal model. Methods. A total of 18 rabbits underwent an operation on their right knees to form contractures. Six limbs in group 1 received four intra-articular injections of decorin; six limbs in group 2 received four intra-articular injections of bovine serum albumin (BSA) over eight days; six limbs in group 3 received no injections. The contracted limbs of rabbits in group 1 were biomechanically and genetically compared with the contracted limbs of rabbits in groups 2 and 3, with the use of a calibrated joint measuring device and custom microarray, respectively. Results. There was no statistical difference in the flexion contracture angles between those limbs that received intra-articular decorin versus those that received intra-articular BSA (66° vs 69°; p = 0.41). Likewise, there was no statistical difference between those limbs that received intra-articular decorin versus those who had no injection (66° vs 72°; p = 0.27). When compared with BSA, decorin led to a statistically significant increase in the mRNA expression of 12 genes (p < 0.01). In addition, there was a statistical change in the mRNA expression of three genes, when compared with those without injection. . Conclusions. In this model, when administered intra-articularly at eight weeks, 2 mg of decorin had no significant effect on joint contractures. However, our genetic analysis revealed a significant alteration in several fibrotic genes. Cite this article: Bone Joint Res 2014;3:82–8