Total Joint Replacement Surgery Research Articles

Total joint replacement surgery for knee osteoarthritis and other non-traumatic diseases: a network meta-analysis

Total joint replacement surgery for knee osteoarthritis and other non-traumatic diseases: a network meta-analysis

Projecting the direct cost burden of osteoarthritis in Canada using a microsimulation model

To estimate the future direct cost of OA in Canada using a population-based health microsimulation model of osteoarthritis (POHEM-OA). We used administrative health data from the province of British Columbia (BC), Canada, a survey of a random sample of BC residents diagnosed with OA (Ministry of Health of BC data), Canadian Institute of Health Information (CIHI) cost data and literature estimates to populate a microsimulation model. Cost components associated with pharmacological and non-pharmacological treatments, total joint replacement (TJR) surgery, as well as use of hospital resources and management of complications arising from the treatment of osteoarthritis (OA) were included. Future costs were then simulated using the POHEM-OA model to construct profiles for each adult Canadian. From 2010 to 2031, as the prevalence of OA is projected to increase from 13.8% to 18.6%, the total direct cost of OA is projected to increase from $2.9 billion to $7.6 billion, an almost 2.6-fold increase (in 2010 $CAD). From the highest to the lowest, the cost components that will constitute the total direct cost of OA in 2031 are hospitalization cost ($2.9 billion), outpatient services ($1.2 billion), alternative care and out-of-pocket cost categories ($1.2 billion), drugs ($1 billion), rehabilitation ($0.7 billion) and side-effect of drugs ($0.6 billion). Projecting the future trends in the cost of OA enables policy makers to anticipate the significant shifts in its distribution of burden in the future.

Bone marrow lesions, subchondral bone cysts and subchondral bone attrition are associated with histological synovitis in patients with end-stage knee osteoarthritis: a cross-sectional study

The aim of this study was to examine the osteoarthritis (OA)-related structural changes associated with histological synovitis in end-stage knee OA patients. Forty end-stage knee OA patients (female: 88%, mean age: 71.8y) were enrolled. All participants underwent 3.0-TMRI. The structural changes, such as cartilage morphology, subchondral bone marrow lesion (BML), subchondral bone cyst (SBC), subchondral bone attrition (SBA), osteophytes, meniscal lesion and synovitis, were scored using the whole-organ MRI scoring (WORMS) method. Synovial samples were obtained from five regions of interest (ROIs) of the knee joint during total joint replacement surgery. The associations between the histological synovitis score (HSS) and WORMS or the synovial expression levels of cyclooxygenase (COX)-2, interleukin (IL)-1β, IL-6 and transforming growth factor (TGF)-β were examined using Spearman's correlation coefficient. Among the seven OA-related structural changes, the BML, SBC, SBA and synovitis were significantly associated with the HSS (r=0.33, 0.35, 0.48 and 0.36, respectively), while other morphological changes were not. Although synovial COX-2, IL-1β or IL-6 expression levels were not associated with the HSS, the synovial TGF-β expression levels were associated with the HSS. The presence of BML, SBC and SBA was associated with histological synovitis in end-stage knee OA patients.

Use of prescription analgesic medication and pain catastrophizing after total joint replacement surgery

ObjectiveTo survey the use of analgesic medication 4.8 years after total joint replacement (TJR) surgery and assess the determinants of medication usage. Patients and methodsOf 852 patients who had undergone TJR for osteoarthritis were recruited from secondary care. Participants (mean age, 73.7 years) responded to a questionnaire on medication use, physical function and pain (WOMAC, VAS and body pain), pain catastrophizing and illness behaviour (somatization). ResultsOnly 37% of study participants were not on any pain relief medication, 25.1% were taking opioids, 6.9% were taking prescription NSAIDs and 25.9% were taking only non-prescription analgesics. Use of NSAIDs correlated with presence of back pain, body pain and high illness behaviour. The strongest associations with use of opioids were severe joint pain, high pain catastrophizing, body and back pain. After adjustment for covariates plus presence of pain, catastrophizing remained significantly associated with higher risk of opioid use (OR = 1.66, 95% CI: 1.13–2.43, p < 0.009) and of other prescription medication that can be used to treat pain (anti-depressants, anti-epileptics and hypnotics) (OR = 2.52, 95% CI: 1.61–3.95, p < 0.0005). ConclusionsUse of opioid medication 4 years post-TJR is very high in our study population. In addition to joint, back and body pain, a major contributor to opioid use is pain catastrophizing. Our data suggest that current opioid and other analgesic prescribing patterns may benefit from considering the catastrophizing characteristics of patients.

CORR Insights®: Morbid Obesity: Increased Risk of Failure After Aseptic Revision TKA.

T he effectiveness of total joint replacement surgery as a treatment for debilitating arthritic afflictions of the knee has spurred increasing demand for this procedure. This increased demand must be tempered by the realization that as the number of total knee replacement patients climbs, the number with complications resulting in revision also will grow. In contrast to the great improvement in life quality that follows a successful total knee replacement, the failed total knee replacement is remarkable for the morbidity, potential mortality, and huge economic costs that result. Although efforts to improve implant design and surgical technique must continue, I am convinced that understanding the contributions of patient comorbidity to poor outcomes is more urgently needed. In this regard, the current paper by Watts and colleagues from theMayo Clinic makes a meaningful contribution. Recent studies have documented that morbid obesity is a risk factor for complications following total knee replacement [1, 2]. In the currentpaper, the authors have also documented that when compared to nonobesity,morbid obesity is associated with 3.8-fold increase in the likelihood of additional revision and a 6.4 fold increase in risk of prosthetic joint infection following revision surgery. Furthermore, functional outcomes also were markedly compromised. Where Do We Need To Go?

Operating theatre ventilation systems and microbial air contamination in total joint replacement surgery: results of the GISIO-ISChIA study

Recent studies have shown a higher rate of surgical site infections in hip prosthesis implantation using unidirectional airflow ventilation compared with turbulent ventilation. However, these studies did not measure the air microbial quality of operating theatres (OTs), and assumed it to be compliant with the recommended standards for this ventilation technique. To evaluate airborne microbial contamination in OTs during hip and knee replacement surgery, and compare the findings with values recommended for joint replacement surgery. Air samplings were performed in 28 OTs supplied with unidirectional, turbulent and mixed airflow ventilation. Samples were collected using passive sampling to determine the index of microbial air contamination (IMA). Active sampling was also performed in some of the OTs. The average number of people in the OT and the number of door openings during the sampling period were recorded. In total, 1228 elective prosthesis procedures (60.1% hip and 39.9% knee) were included in this study. Of passive samplings performed during surgical activity in unidirectional airflow ventilation OTs (U-OTs) and mixed airflow OTs (M-OTs), 58.9% and 87.6% had IMA values >2, respectively. Of samplings performed during surgical activity in turbulent airflow OTs (T-OTs) and in turbulent airflow OTs with the surgical team wearing Steri-Shield Turbo Helmets (TH-OTs), 8.6% and 60% had IMA values ≤ 2, respectively. Positive correlation was found between IMA values and the number of people in the OT and the number of door openings (P < 0.001). In addition, correlation was found between active and passive sampling (P < 0.001). These findings challenge the belief that unidirectional systems always provide acceptable airborne bacterial counts.

A1.4 Inflammatory microenvironment of rheumatoid and osteoarthritic joint affects immunomodulatory activity of adipose-derived mesenchymal stem cells

Background and objectives Adipose-derived mesenchymal stem cells (ASCs) have immunomodulatory properties, but their activity is dependent on signals provided by local microenvironment. ASCs administration in rheumatoid arthritis (RA) did not bring consistent results, while in osteoarthritis (OA) it has beneficial effects. It is likely that proinflammatory milieu of rheumatoid joint affects ASCs activity. To test this hypothesis, the function of rheumatoid ASCs (RA-ASCs) and osteoarthritic ASCs (OA-ASCs) isolated from infrapatellar fat pad of the knee joint have been analysed. Materials and methods Infrapatellar fat pads were obtained from 29 RA and 12 OA patients undergoing total knee joint replacement surgery. Then, ASCs were isolated accordingly to routinely applied procedure. ASCs were treated or not with IFNγ or TNF. The expression of indoleamine 2,3-dioxygenase and heme oxygenase 1 mRNA was measured using quantitative PCR, while ASCs secretory potential was assessed by specific ELISAs. Rheumatoid synovial fibroblasts (RA-FLS) or peripheral blood mononuclear cells (PBMCs) from healthy donors were cultured in ASC-conditioned media or co-cultured with ASCs. Next, cytokines secretion and cells proliferation were measured using ELISAs and bromodeoxyuridine/ 3 H-thymidine proliferation assays, respectively. Results RA- and OA-ASCs activity in vitro is comparable, nonetheless some differences in spontaneous secretory activity and heme oxygenase 1 mRNA expression have been observed. Unstimulated RA- and OA-ASCs slightly inhibited PBMCs proliferation and induced IL-10 secretion but increased IL-17A production and failed to suppress release of other proinflammatory factors (TNF, IFNγ, RANTES) by PBMCs. Under TNF stimulation, RA- and OA-ASCs up-regulated IL-6 and MMP-3 secretion in RA-FLS cultures and IL-17A release by PBMCs. ASCs treatment with IFNγ or TNF did not intensify their anti-inflammatory activity. Conclusions Our study demonstrates that immunosuppressive function of RA- and OA-ASCs derived from infrapatellar fat pad is impaired. Possibly, it is due to the localisation of ASCs in the site of inflammation. Moreover, TNF triggers proinflammatory properties of ASCs which indicates that when administered to the rheumatoid joint, ASCs may shift from an anti-inflammatory to proinflammatory phenotype. Acknowledgements This work was supported by the Polish National Science Centre (grant no. 2011/01/N/NZ5/00932) and by the European Union funds (European Social Fund, Human Capital Programme).

Prosthesis loading after temporomandibular joint replacement surgery: a musculoskeletal modeling study.

One of the most widely reported complications associated with temporomandibular joint (TMJ) prosthetic total joint replacement (TJR) surgery is condylar component screw loosening and instability. The objective of this study was to develop a musculoskeletal model of the human jaw to assess the influence of prosthetic condylar component orientation and screw placement on condylar component loading during mastication. A three-dimensional model of the jaw comprising the maxilla, mandible, masticatory muscles, articular cartilage, and articular disks was developed. Simulations of mastication and a maximum force bite were performed for the natural TMJ and the TMJ after prosthetic TJR surgery, including cases for mastication where the condylar component was rotated anteriorly by 0 deg, 5 deg, 10 deg, and 15 deg. Three clinically significant screw configurations were investigated: a complete, posterior, and minimal-posterior screw (MPS) configuration. Increases in condylar anterior rotation led to an increase in prosthetic condylar component contact stresses and substantial increases in condylar component screw stresses. The use of more screws in condylar fixation reduced screw stress magnitudes and maximum condylar component stresses. Screws placed superiorly experienced higher stresses than those of all other condylar fixation screws. The results of the present study have important implication for the way in which prosthetic components are placed during TMJ prosthetic TJR surgery.

Functionally deficient mesenchymal stem cells reside in the bone marrow niche with M2-macrophages and amyloid-β protein adjacent to loose total joint implants.

We sought to demonstrate whether there is a difference in the local mesenchymal stem cells (MSC) niche obtained from patients undergoing their first total joint replacement surgery versus those patients undergoing a revision surgery for an failing total joint implant. Bone marrow aspirates collected from patients undergoing revision total joint arthroplasty were observed to be less clonal and the expression of PDGFRα, CD51, ALCAM, endoglin, CXCL12, nestin, and nucleostemin were decreased. Revision MSC were also less able to commit to an osteoblast-lineage or an adipocyte-lineage. Further, in revision MSC, OPG, and IL6 expression were increased. Monocytes, derived from revision whole marrow aspirates, were less capable of differentiating into osteoclasts, the cells implicated in the pathologic degradation of bone. Osteoclasts were also not observed in tissue samples collected adjacent to the implants of revision patients; however, the alternatatively activated M2-macrophage phenotype was observed in parallel with pathologic accumulations of amyloid-β, τ-protien and 3-nitrotyrosine. Despite the limited numbers of patients examined, our data suggest that nucleostemin may be a useful functional marker for MSC while the observation of M2-macrophage infiltration around the implant lays the foundation for future investigation into a novel mechanism that we propose is associated with loose total joint implants.

Implementation of Patient-Reported Outcome Measures in U.S. Total Joint Replacement Registries: Rationale, Status, and Plans

In the U.S. and abroad, the use of patient-reported outcome measures to evaluate the impact of total joint replacement surgery on patient quality of life is increasingly common. Analyses of patient-reported outcomes have documented substantial pain relief and functional gain among the vast majority of patients managed with total joint replacement. In addition, postoperative patient-reported outcomes are useful to identify persistent pain and suboptimal outcomes in the minority of patients who have them. The leaders of five U.S. total joint replacement registries report the rationale, current status, and vision for the use of patient-reported outcome measures in U.S. total joint replacement registries. Surgeon leaders of the Function and Outcomes Research for Comparative Effectiveness in Total Joint Replacement registry, American Joint Replacement Registry, California Joint Replacement Registry, Michigan Arthroplasty Registry Collaborative Quality Initiative, and Virginia Joint Registry report the rationale supporting the adoption of patient-reported outcome measures, factors associated with the selection and successful implementation of patient-reported outcome measures, and barriers to complete and valid data. U.S. registries are at varied stages of implementation of preoperative surveys and postoperative total joint replacement outcome measures. Surgeon leaders report unified rationales for adopting patient-reported outcome measures: to capture data on pain relief and functional gain following total joint replacement as well as to identify suboptimal implant performance. Key considerations in the selection of a patient-reported outcome measure include its ability to measure both joint pain and physical function while limiting any burden on patients and surgeons related to its use. Complete patient-reported outcomes data will be associated with varied modes of survey completion, including options for home-based completion, to ensure consistent timing and data capture. The current stage of implementation of patient-reported outcome measures varies widely among U.S. registries. Nonetheless, evidence from the Function and Outcomes Research for Comparative Effectiveness in Total Joint Replacement registry supports the feasibility of successful implementation of patient-reported outcome measures with careful attention to the selection of the outcome measure, mode and timing of postoperative administration, and minimization of any burden on the patient and surgeon.

Safety of Desirudin Administered in the Immediate Postoperative Period Following Joint Replacement Surgery: An Observational Study

INTRODUCTION. Desirudin is a recombinant direct thrombin inhibitor (DTI) approved in the US for the prophylaxis of deep vein thrombosis (DVT), which may lead to pulmonary embolism (PE), in patients undergoing elective hip replacement surgery, and approved in the EU for the prevention of DVT in patients undergoing elective hip or knee replacement surgery. Evidence suggests that desirudin may possess a better safety profile in higher risk patients than other thromboprophylactic agents, and trials evaluating the safety of desirudin have indicated good tolerability without frequent adverse events. The most common adverse event associated with desirudin is hemorrhagic reactions. This observational study evaluated bleeding events and wound outcomes in patients receiving desirudin during the immediate postoperative period after total joint replacement surgery (hip and/or knee), followed by rivaroxaban for outpatient DVT prophylaxis.METHODS. Patients undergoing total hip (THR) and/or total knee (TKR) replacement were eligible to participate in the study. Inpatient DVT prophylaxis was initiated with desirudin 15 mg BID the evening following the completion of surgery. At the discretion of the treating physician, DVT prophylaxis continued with rivaroxaban 10 mg on an outpatient basis following hospital discharge. The primary endpoints were (1) fall in hemoglobin (g/dL) and (2) degree of wound discharge at release from hospital. Wound discharge was rated on a 5-point scale of bruising ranging from 0 (negligible bruising) to 4 (bright red blood). Secondary endpoints included degree of wound discharge at the first postoperative follow-up visit. Endpoint assessments were conducted at hospital discharge, at the first postoperative visit, and at the staple-removal visit. All patients were required to follow-up with their surgeons in the clinic or via telephone between postoperative day 7 and postoperative day 14.RESULTS. Patient demographic and baseline data are presented in Table 1. As shown, 151 patients participated in the study (THR, n=37; TKR, n=111; THR/TKR, n=2). Patients ranged between 37-98 years of age, with a mean age of 62 years. Almost 75% of the patients were female. It is also important to note that the overall patient population had a mean body mass index (BMI) of 35.9 kg/m2. Data for the primary endpoints (fall in hemoglobin and wound discharge at the time of release from the hospital) and the secondary endpoint of wound discharge at follow-up are shown in Table 2. There was a low incidence of wound discharge (score >0) at release (n=2; 1 patient had a score of 1, 1 patient had a score of 4); at follow-up, a higher incidence of wound discharge (score >0) was noted (n=44). There was also an average fall in hemoglobin in the range of approximately 3-4 g/dL across age, gender, type of surgery, and BMI.CONCLUSION. The demographic characteristics of patients in this study suggest a patient population with a relatively high risk of venous thromboembolism (VTE) due to age and obesity. These data suggest that the use of desirudin in patients who may be at a higher risk for VTE due to age or obesity is not associated with adverse wound outcomes or increased bleeding risk.TABLE 1Demographic or Baseline CharacteristicsPatients (N=151)Median age, years (range)62 (37-98)Mean weight, kg (SD)100.59 (25.16)Mean BMI, kg/m2 (SD)a35.96 (8.63)Age group, n (%)<65 years90 (59.6)≥65 years61 (40.4)Sex, n (%)bMale37 (24.5)Female112 (74.2)Race/ethnicity, n (%)cWhite86 (57)Black54 (35.8)Latin American and Mexican3 (2)Asian2 (1.3)Native American2 (1.3)Other1 (0.7)Surgery type, n (%)aTHR37 (24.5)TKR111 (73.5)THR/TKR2 (1.3)aData missing from 1 patientbData missing from 2 patientscData missing from 3 patientsTABLE 2PopulationWound Discharge at Release, Mean (SD)Wound Discharge at Follow-up, Mean (SD)Change in Hemoglobin, Mean (SD)Agea<65 (n=90)0.07 (0.48)0.43 (0.75)-4.13 (1.11)≥65 (n=61)0 (0)0.27 (0.71)-3.85 (1.52)GenderbMale (n=37)0.17 (0.75)0.42 (0.81)-4.24 (1.29)Female (n=112)0 (0)0.41 (0.72)-3.93 (1.29)Type of SurgerycTHR (n=37)0 (0)0.25 (0.73)-3.98 (1.36)TKR (n=111)0.06 (0.43)0.45 (0.74)-4.04 (1.27)THR + TKR (n=2)0 (0)0.50 (0.71)-3.05 (2.19)BMIc, kg/m2Nonobesed (n=40)0 (0)0.3 (0.64)-4.15 (1.49)Obesee (n=109)0.1 (0.44)0.4 (0.73)-3.97 (1.23)aData missing from 7 patientsbData missing from 2 patientscData missing from 1 patientdNonobese defined as BMI≤30eObese defined as BMI>30 DisclosuresMeyer:Marathon Pharma: Employment.

Hospital volume affects outcome after total knee arthroplasty

Background and purpose — The influence of hospital volume on the outcome of total knee joint replacement surgery is controversial. We evaluated nationwide data on the effect of hospital volume on length of stay, re-admission, revision, manipulation under anesthesia (MUA), and discharge disposition for total knee replacement (TKR) in Finland. Patients and methods — 59,696 TKRs for primary osteoarthritis performed between 1998 and 2010 were identified from the Finnish Hospital Discharge Register and the Finnish Arthroplasty Register. Hospitals were classified into 4 groups according to the number of primary and revision knee arthroplasties performed on an annual basis throughout the study period: 1–99 (group 1), 100–249 (group 2), 250–449 (group 3), and ≥ 450 (group 4). The association between hospital procedure volume and length of stay (LOS), length of uninterrupted institutional care (LUIC), re-admissions, revisions, MUA, and discharge disposition were analyzed. Results — The greater the volume of the hospital, the shorter was the average LOS and LUIC. Smaller hospital volume was not unambiguously associated with increased revision, re-admission, or MUA rates. The smaller the annual hospital volume, the more often patients were discharged home. Interpretation — LOS and LUIC ought to be shortened in lower-volume hospitals. There is potential for a reduction in length of stay in extended institutional care facilities.

Osteoarthritis pathogenesis: a review of molecular mechanisms.

Osteoarthritis (OA), the most prevalent chronic joint disease, increases in prevalence with age, and affects majority of individuals over the age of 65 and is a leading musculoskeletal cause of impaired mobility in the elderly. Because the precise molecular mechanisms which are involved in the degradation of cartilage matrix and development of OA are poorly understood and there are currently no effective interventions to decelerate the progression of OA or retard the irreversible degradation of cartilage except for total joint replacement surgery. In this paper, the important molecular mechanisms related to OA pathogenesis will be summarized and new insights into potential molecular targets for the prevention and treatment of OA will be provided.

You'll know when you're ready: a qualitative study exploring how patients decide when the time is right for joint replacement surgery.

BackgroundWhile some studies have identified patient readiness as a key component in their decision whether to have total joint replacement surgery (TJR), none have examined how patients determine their readiness for surgery. The study purpose was to explore the concept of patient readiness and describe the factors patients consider when assessing their readiness for TJR.MethodsNine focus groups (4 pre-surgery, 5 post-surgery) were held in four Canadian cities. Participants had been either referred to or seen by an orthopaedic surgeon for TJR or had undergone TJR. The method of analysis was qualitative thematic analysis.ResultsThere were 65 participants, 66% female and 34% male, 80% urban, with an average age of 65 years (SD 10). Readiness reflected both the surgeon’s advice that the patient was clinically ready for surgery and the patient’s feeling that they were both mentally and physically ready for surgery. Mental readiness was described as an internal state or feeling of being ready or prepared while physical readiness was described as being physically fit and in good shape for surgery. Factors associated with readiness included: 1) pain: its severity, the ability to cope with it, and how it affected their quality of life; 2) mental preparation; 3) physical preparation; 4) the optimal timing of surgery, including age, anticipated rate of deterioration, prosthesis lifespan and the length of the waiting list.ConclusionsPatient readiness should be assessed prior to TJR. By assessing patient readiness, health professionals can elucidate and deal with concerns and fears, understand and calibrate expectations, assess coping strategies, and use this information to help determine optimal timing, both before and after the surgical consultation.

The Effect of Animal-Assisted Therapy on Pain Medication Use After Joint Replacement

ABSTRACTAnimal-assisted therapy (AAT) has been used in a variety of healthcare settings and studies to evaluate the potential patient benefits are warranted. This retrospective study measured the impact of AAT on the use of oral pain medications by adults after total joint replacement surgery. One group of patients received care in a hospital with an AAT program and the comparison group was in a hospital without an AAT program. Adult patient cohorts were matched on: age, gender, ethnicity, length of stay, and Diagnosis Related Group code for type of total joint replacement. Pain medication doses, converted into morphine equivalent daily doses (MEDD), were compared. Pain medication use was significantly less in the AAT group: 15.32 mg vs. 21.16 (t(119) = 2.72, p = 0.007). The effectiveness of AAT in decreasing the need for pain medication and its effect on patient well-being in the post-operative period and in other settings deserves further study.

Application of Digital Templates to Guide Total Alloplastic Joint Replacement Surgery With Biomet Standard Replacement System

To design and manufacture digital templates to guide Biomet total alloplastic joint replacement surgery (Biomet, Warsaw, IN) and evaluate the clinical efficacy. Six patients who underwent total alloplastic joint replacement surgery from November 2013 to March 2014 were included in this study. Before surgery, the Biomet standard prostheses were scanned and imported into the ProPlan CMF 1.4 software (Materialise NV, Leuven, Belgium) for virtual positioning and osteotomy planning. Digital templates were then designed to guide intraoperative bone trimming and prosthesis placement. A postoperative computed tomography scan was taken and used to measure how well the postsurgical images corresponded to the images generated in the preoperative plan. The digital templates were smoothly positioned and easily adapted, and they accurately guided bone trimming and prosthesis implantation. In addition, vital anatomic structures such as the skull base and inferior alveolar neurovascular bundle were not injured during the procedures. The result of the merged postoperative and preoperative computed tomography scans showed that the position of the prostheses corresponded quite accurately to the preoperative design, with an error of 1.139±0.183 mm. Digital templates can accurately guide the bone trimming required for placement of Biomet total alloplastic joints. Likewise, these templates help place the prostheses in the desired locations, enhance stability, and avoid damage to the skull base and inferior alveolar neurovascular bundle.

Mitochondrial DNA haplogroups modulate the radiographic progression of Spanish patients with osteoarthritis.

Not all patients with osteoarthritis (OA) show the same disease progression, as some of them remain relatively stable over time, while others progress to severe structural deterioration of the joint. In this sense, the main goal of both genetic and protein biomarkers in OA is to predict not only the risk of OA at an earlier stage of the disease but also which OA patients are more likely to progress to severe disease. Taking into account the incidence of the mitochondria and the mtDNA haplogroups in the pathogenesis of OA, the main objective of this work was to evaluate the incidence of the mtDNA haplogroups in the radiographic progression of the OA disease in a well-characterized follow-up cohort of Spanish patients. DNA from 281 OA patients from Hospital Universitario A Coruña was isolated to determine the European mtDNA haplogroups. Knee or hip radiographs from all affected joints were obtained at two time points with at least 36 months apart. Radiographs were evaluated using the Kellgren/Lawrence (K/L) scale; radiographic OA progression was defined as any radiographic worsening of the K/L joint score. Statistical analyses included Kaplan-Meier survival curves and Cox regression models. Patients belonging to the cluster TJ showed a slower radiographic OA progression than patients in the cluster KU (p = 0.036). Moreover, patients carrying the most common mtDNA haplogroup H are more apt to require total joint replacement surgery than non-H patients (p = 0.049). The inherited mitochondrial variants influence the radiographic progression of OA and could be considered among the genetic variants taken into account when the radiographic progression of OA is analyzed.

Optimisation of a two-liquid component pre-filled acrylic bone cement system: a design of experiments approach to optimise cement final properties.

The initial composition of acrylic bone cement along with the mixing and delivery technique used can influence its final properties and therefore its clinical success in vivo. The polymerisation of acrylic bone cement is complex with a number of processes happening simultaneously. Acrylic bone cement mixing and delivery systems have undergone several design changes in their advancement, although the cement constituents themselves have remained unchanged since they were first used. This study was conducted to determine the factors that had the greatest effect on the final properties of acrylic bone cement using a pre-filled bone cement mixing and delivery system. A design of experiments (DoE) approach was used to determine the impact of the factors associated with this mixing and delivery method on the final properties of the cement produced. The DoE illustrated that all factors present within this study had a significant impact on the final properties of the cement. An optimum cement composition was hypothesised and tested. This optimum recipe produced cement with final mechanical and thermal properties within the clinical guidelines and stated by ISO 5833 (International Standard Organisation (ISO), International standard 5833: implants for surgery-acrylic resin cements, 2002), however the low setting times observed would not be clinically viable and could result in complications during the surgical technique. As a result further development would be required to improve the setting time of the cement in order for it to be deemed suitable for use in total joint replacement surgery.

Evaluation of discharge telephone calls following total joint replacement surgery.

The average length of stay for patients undergoing total joint replacement surgery at a large teaching hospital is 3 days. This requires a comprehensive discharge education plan. The purpose of this prospective quality improvement project was to evaluate patients' understanding of postoperative care at home, screen for postoperative complications, and identify inconsistencies or gaps in discharge teaching. During a 1-year evaluation period, patients who underwent total joint replacement surgery were interviewed via a telephone call following discharge to home. Patients were asked questions regarding general feeling, pain, wound appearance, edema, anticoagulation, and physical therapy. Concerns reported most frequently included medication side effects, deep vein thrombosis prophylaxis, and the use of assistive devices. The majority of patients reported receiving adequate discharge instructions. This quality improvement project has resulted in improved discharge teaching based on patients' identified needs and early intervention for the prevention of postoperative complications.

Periprosthetic bone loss: diagnostic and therapeutic approaches.

Total joint replacement surgery is being performed on an increasingly large part of the population. Clinical longevity of implants depends on their osseointegration, which is influenced by the load, the characteristics of the implant and the bone-implant interface, as well as by the quality and quantity of the surrounding bone. Aseptic loosening due to periprosthetic osteolysis is the most frequent known cause of implant failure. Wear of prosthetic materials results in the formation of numerous particles of debris that cause a complex biological response. Dual-energy X-ray Absorptiometry (DXA) is regarded as an accurate method to evaluate Bone Mineral Density (BMD) around hip or knee prostheses. Further data may be provided by a new device, the Bone Microarchitecture Analysis (BMA), which combines bone microarchitecture quantification and ultra high resolution osteo-articular imaging. Pharmacological strategies have been developed to prevent bone mass loss and to extend implant survival. Numerous trials with bisphosphonates show a protective effect on periprosthetic bone mass, up to 72 months after arthroplasty. Strontium ranelate has been demonstrated to increase the osseointegration of titanium implants in treated animals with improvement of bone microarchitecture and bone biomaterial properties.