Association Between Pharmacologic Treatment of Depression and Patient-Reported Outcomes Following Total Hip and Knee Arthroplasty.

BACKGROUND: Depression is associated with inferior outcomes following hip or knee arthroplasty, though it remains unclear if this relationship is modifiable. This study examined the association between pharmacologic treatment of depression and patient-reported outcomes. METHODS: This retrospective cohort study of 1,651 total hip arthroplasty (THA) and 1,792 total knee arthroplasty (TKA) procedures between October 2012 and June 2019 used institutional registry data linked to nationwide pharmaceutical claims. The primary outcome was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) global score, with pain and function sub-scales assessed as secondary outcomes. The TKA and THA patients were analyzed separately via mixed-effect linear regression to compare patients who had depression treated with antidepressants (TKA, n = 210; THA, n = 150) to those who had untreated depression (TKA, n = 43; THA; n = 50), and those who did not have depression (TKA, n = 1,539; THA, n = 1,451). RESULTS: Among patients who had depression, not receiving preoperative antidepressant therapy was associated with smaller improvements in WOMAC global scores (TKA, adjusted mean difference [MD]: -13.1 points, 95% CI [confidence interval]: -21.4 to -4.8; THA, MD: -8.5 points, 95% CI: -15.7 to -1.2) at two years after surgery, but not at one year (TKA, MD: -5.4 points, 95% CI: -12.9 to 2.1; THA, MD: -6.3 points, 95% CI: -12.9 to 0.3). Those who did not have depression had similar improvements in WOMAC global scores to those who had treated depression at both one (TKA, MD: 0.8 points, 95% CI: -2.7 to 4.4; THA, MD: 1.8 points, 95% CI: -1.8 to 5.4) and two years (TKA, MD: -1.1 points, 95% CI: -4.9 to 2.7; THA, MD: -1.6 points, 95% CI: -5.6 to 2.3). The findings were consistent with secondary outcomes. CONCLUSION: Among patients who have depression, antidepressant therapy before TKA or THA is associated with improved outcomes. Additional studies are needed to establish the impact of interventions to address untreated depression before surgery.

Penetration of Vancomycin into Noninfected Bone in Patients Undergoing Total Joint Arthroplasty Evaluated by a Minimal Physiologically Based Population Pharmacokinetic Modeling Approach.

Arthroplasty is a healthcare priority and represents high volume, high cost surgery. Periprosthetic joint infection (PJI) results in significant mortality, thus it is vital that the risk for PJI is minimized. Vancomycin is recommended for surgical prophylaxis in total joint arthroplasty (TJA) by current clinical practice guidelines endorsed by the Infectious Diseases Society of America. This study aimed to develop a new assay to determine vancomycin concentrations in serum and bone, and a minimal physiologically based population PK (mPBPK) model to evaluate vancomycin bone penetration in noninfected patients. Eleven patients undergoing TJA received 0.5-2.0 g intravenous vancomycin over 12-150 min before surgery. Excised bone specimens and four blood samples were collected per patient. Bone samples were pulverized under liquid nitrogen using a cryogenic mill. Vancomycin concentrations in serum and bone were analyzed by liquid chromatography-tandem mass spectrometry and subjected to mPBPK modeling. Vancomycin serum and bone concentrations ranged from 9.30 to 86.6 mg/L, and 1.94-37.0 mg/L, respectively. Average bone to serum concentration ratio was 0.41 (0.16-1.0) based on the collected samples. The population mean total body clearance was 2.12L/h/kg0.75. Inclusion of total body weight as a covariate substantially decreased interindividual variability in clearance. The bone/blood partition coefficient (Kpbone) was estimated at 0.635, reflecting the average bone/blood concentration ratio at steady-state. The model predicted median ratio of vancomycin area under the curve (AUC) for bone/AUC for serum was 44%. Observed vancomycin concentrations in bone were overall consistent with perfusion-limited distribution from blood to bone. An mPBPK model overall well described vancomycin concentrations in serum and bone.

Patients' Views on AI for Risk Prediction in Shared Decision-Making for Knee Replacement Surgery: Qualitative Interview Study.

BACKGROUND: The use of artificial intelligence (AI) in decision-making around knee replacement surgery is increasing, and this technology holds promise to improve the prediction of patient outcomes. Ambiguity surrounds the definition of AI, and there are mixed views on its application in clinical settings. OBJECTIVE: In this study, we aimed to explore the understanding and attitudes of patients who underwent knee replacement surgery regarding AI in the context of risk prediction for shared clinical decision-making. METHODS: This qualitative study involved patients who underwent knee replacement surgery at a tertiary referral center for joint replacement surgery. The participants were selected based on their age and sex. Semistructured interviews explored the participants' understanding of AI and their opinions on its use in shared clinical decision-making. Data collection and reflexive thematic analyses were conducted concurrently. Recruitment continued until thematic saturation was achieved. RESULTS: Thematic saturation was achieved with 19 interviews and confirmed with 1 additional interview, resulting in 20 participants being interviewed (female participants: n=11, 55%; male participants: n=9, 45%; median age: 66 years). A total of 11 (55%) participants had a substantial postoperative complication. Three themes captured the participants' understanding of AI and their perceptions of its use in shared clinical decision-making. The theme Expectations captured the participants' views of themselves as individuals with the right to self-determination as they sought therapeutic solutions tailored to their circumstances, needs, and desires, including whether to use AI at all. The theme Empowerment highlighted the potential of AI to enable patients to develop realistic expectations and equip them with personalized risk information to discuss in shared decision-making conversations with the surgeon. The theme Partnership captured the importance of symbiosis between AI and clinicians because AI has varied levels of interpretability and understanding of human emotions and empathy. CONCLUSIONS: Patients who underwent knee replacement surgery in this study had varied levels of familiarity with AI and diverse conceptualizations of its definitions and capabilities. Educating patients about AI through nontechnical explanations and illustrative scenarios could help inform their decision to use it for risk prediction in the shared decision-making process with their surgeon. These findings could be used in the process of developing a questionnaire to ascertain the views of patients undergoing knee replacement surgery on the acceptability of AI in shared clinical decision-making. Future work could investigate the accuracy of this patient group's understanding of AI, beyond their familiarity with it, and how this influences their acceptance of its use. Surgeons may play a key role in finding a place for AI in the clinical setting as the uptake of this technology in health care continues to grow.

Low grade of radiographic osteoarthritis predicts unsatisfactory response of the contralateral knee replacement in two-stage bilateral total knee arthroplasty.

PURPOSE: It is difficult to counsel patients with bilateral osteoarthritis who are unsatisfied with their first knee replacement as to whether they are likely to have a better outcome after the contralateral knee is replaced. The purpose of this study was to determine whether predictive factors can be found to prognosticate outcome of the second-side knee replacement when a patient has an unsatisfactory response to the first, with the hypothesis that predictors, such as prosthetic factors and radiographic level of osteoarthritis, may be able to predict a satisfactory response to the contralateral knee replacement. MATERIALS AND METHODS: An analysis of staged bilateral knee replacements performed at a tertiary arthroplasty centre from 2012 to 2018 was undertaken. A total of 550 knee replacements in 275 patients were included in this study. The primary variable measured was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score. Satisfactory response to surgery was defined as a WOMAC score improved by 17 points or more, and 56 or greater. Patients who did not achieve a satisfactory response with their first knee replacement were further analysed for predictive factors (age, sex, pre-operative score, mental score, socioeconomic status, type of prosthesis, use of navigation, patella resurfacing and radiographic osteoarthritis) of an unsatisfactory response for their contralateral knee replacement. RESULTS: Overall, 44 (16%) patients failed to achieve a satisfactory response from both their first and contralateral knee replacements. The factor most predictive of an unsatisfactory response to their first knee replacement was pre-operative mental health score. However, in patients who did not achieve a satisfactory response with their first knee replacement, radiographic osteoarthritis, as measured by the Kellgren-Lawrence (KL) score was the main predictor of satisfactory response for their contralateral knee replacement. Only patients with KL grade 4 osteoarthritis were likely to have a satisfactory response with their contralateral knee replacements (KL4 versus KL3, Odds ratio 3.57 (CI 1.26-10.03) p = 0.016*). Patients with KL grade 3 osteoarthritis were unlikely to have a satisfactory response, and in this series, no patient with KL grade 2 osteoarthritis had a satisfactory response. CONCLUSION: In a patient who has an unsatisfactory response to their first knee replacement, the best predictor of achieving a satisfactory response to his/her contralateral knee replacement is the level of radiographic osteoarthritis in that knee. LEVEL OF EVIDENCE: IV: Retrospective Cohort study.

Patterns and Predictors of Outpatient Antibiotic Dispensation Following Total Hip and Knee Arthroplasty.

BACKGROUND: This study aimed to evaluate the month-to-month prevalence of antibiotic dispensation in the 12 months before and after total knee arthroplasty (TKA) and total hip arthroplasty (THA) and to identify factors associated with antibiotic dispensation in the month immediately following the surgical procedure. METHODS: In total, 4,115 THAs and TKAs performed between April 2013 and June 2019 from a state-wide arthroplasty referral center were analyzed. A cross-sectional study used data from an institutional arthroplasty registry, which was linked probabilistically to administrative dispensing data from the Australian Pharmaceutical Benefits Scheme. Multivariable logistic regression was carried out to identify patient and surgical risk factors for oral antibiotic dispensation. RESULTS: Oral antibiotics were dispensed in 18.3% of patients following primary TKA and 12.0% of patients following THA in the 30 days following discharge. During the year after discharge, 66.7% of TKA patients and 58.2% of THA patients were dispensed an antibiotic at some point. Patients with poor preoperative health status were more likely to have antibiotics dispensed in the month following THA or TKA. Older age, undergoing TKA rather than THA, obesity, inflammatory arthritis, and experiencing an in-hospital wound-related or other infectious complications were associated with increased antibiotic dispensation in the 30 days following discharge. CONCLUSION: A high rate of antibiotic dispensation in the 30 days following THA and TKA has been observed. Although resource constraints may limit routine wound review for all patients by a surgeon, a select cohort may benefit from timely specialist review postoperatively. Several risk factors identified in this study may aid in identifying appropriate candidates for such changes to follow-up care.

Placebo Surgery Controlled Trials: Do They Achieve What They Set Out To Do? A Systematic Review.

OBJECTIVE: To explore whether placebo surgery controlled trials achieve what they set out to do by investigating discrepancy between projected and actual design aspects of trials identified through systematic review methods. SUMMARY BACKGROUND: Interest in placebo surgery controlled trials is growing in response to concerns regarding unnecessary surgery and the societal cost of low-value healthcare. As questions about the justifiability of using placebo controls in surgery have been addressed, attention is now being paid to more practical concerns. METHODS: Six databases were searched from inception - May 2020 (MEDLINE, Embase, Emcare, APA PsycInfo, CINAHL, Cochrane Library). Placebo surgery controlled trials with a published protocol were included. Three authors extracted "projected" design aspects from protocols and "actual" design aspects from main findings papers. Absolute and relative difference between projected and actual design aspects were presented for each trial. Trials were grouped according to whether they met their target sample size ("completed") and were concluded in a timely fashion. Pairs of authors assessed risk of bias. RESULTS: Of 24 trials with data available to analyse; 3 were completed and concluded within target timeframe; 10 were completed and concluded outside the target timeline; 4 were completed without clear target timeframes; 2 were incomplete and concluded within the target framework; 5 were incomplete and concluded outside the target timeline. Trials which reached the recruitment target underestimated trial duration by 88% and number of recruitment sites by 87%. CONCLUSIONS: Trialists need to factor additional time and sites into future placebo surgery controlled trials. A robust reporting framework of projected and actual trial design is imperative for trialists to learn from their predecessors. REVIEW REGISTRATION: PROSPERO (CRD42019133296).

Circulating tumor DNA for malignant peripheral nerve sheath tumors in neurofibromatosis type 1.

PURPOSE: The leading cause of early death in patients with neurofibromatosis type 1 (NF1) is malignant peripheral nerve sheath tumor (MPNST). The principles of management include early diagnosis, surgical clearance and close monitoring for tumor recurrence. Current methods for diagnosis, detection of residual disease and monitoring tumor burden are inadequate, as clinical and radiological features are non-specific for malignancy in patients with multiple tumors and lack the sensitivity to identify early evidence of malignant transformation or tumor recurrence. Circulating tumor DNA (ctDNA) is a promising tool in cancer management and has the potential to improve the care of patients with NF1. In the following article we summarise the current understanding of the genomic landscape of MPNST, report on the previous literature of ctDNA in MPNST and outline the potential clinical applications for ctDNA in NF1 associated MPNST. Finally, we describe our prospective cohort study protocol investigating the utility of using ctDNA as an early diagnostic tool for MPNSTs in NF1 patients.

Opioid Use and Total Joint Replacement.

PURPOSE OF REVIEW: We provide an overview of recent research into the relationship between preoperative opioid use and total joint replacement outcomes. RECENT FINDINGS: Recent findings indicate that total joint replacement patients with a history of preoperative opioid use experience higher rates of infection, revision, short-term complications, and prolonged postoperative opioid use, along with fewer improvements in pain and function following surgery. These risks are particularly pronounced among chronic opioid users. While the baseline risk profiles of these patients may contribute to higher rates of adverse outcomes, it is also plausible that certain outcomes are directly impacted by opioid use through mechanisms such as opioid-induced hyperalgesia and immunosuppression. There is little available data on the efficacy of interventions that aim to mitigate these risks. Well-designed clinical trials are needed to evaluate the efficacy of targeted perioperative interventions that aim to improve outcomes for this high-risk surgical population. Where such trials are not feasible, additional high-quality observational studies are necessary to further our understanding of the mechanisms underlying the relationships between opioid use and specific adverse outcomes.

Risk Factors for Chronic Opioid Use Following Hip and Knee Arthroplasty: Evidence from New Zealand Population Data.

BACKGROUND: Patients awaiting total joint arthroplasty (TJA) have high rates of opioid use, and many continue to use opioid medications long term after surgery. The objective of this study is to estimate the risk factors associated with chronic opioid use after TJA in a comprehensive population-based cohort. METHODS: All patients undergoing TJA in the New Zealand public healthcare system were identified from Ministry of Health records. Dispensing of opioid medications up to 3 years postsurgery and potential risk factors, including demographic, socioeconomic, and surgery-related characteristics, pre-existing medical comorbidities, and use of other analgesic medications prior to surgery, were identified from linked population databases. Logistic regression analysis was used to identify factors associated with chronic postoperative opioid use. RESULTS: The strongest risk factor for chronic postoperative opioid use was preoperative opioid use. Other significant risk factors included perioperative opioid use, history of alcohol or drug abuse, younger age, female gender, knee arthroplasty, several comorbid health conditions, and preoperative use of some analgesic medications. Protective factors included higher education levels and preoperative use of nonsteroidal anti-inflammatory drugs. Most risk factors had similar effects on chronic postoperative opioid use irrespective of the length of follow-up considered (1, 2, or 3 years). CONCLUSION: This study of a comprehensive nationwide population-based cohort of TJA patients with 3 years of follow-up identified several modifiable risk factors and other easily measured patient characteristics associated with higher risk of long-term postoperative opioid use.

Knee Arthroplasty Component Malrotation Does Not Affect Function or Quality of Life in the Short to Medium Term.

BACKGROUND: Component rotation in total knee arthroplasty is thought to affect patella tracking, flexion gap, and balancing and hence is hypothesized to affect function, pain, and longevity. Few studies have directly correlated post-operative component rotation to function and quality of life in the short to medium term post-operatively, with findings in the current literature conflicting. METHODS: A retrospective study of prospectively collected data was used to determine the effect of femoral, tibial, and combined component rotation in primary total knee arthroplasty with primary outcomes being function as measured by the Knee Society Score, pain and quality of life as measured by the Short-Form 12 score, and secondary outcome being prosthesis failure. Malrotation was defined using the current literature as being internally rotated from neutral, or externally rotated greater than 5° for the femoral component, internally rotated greater than 6° for the tibial component, or internally rotated from neutral for the 2 components combined. RESULTS: No clinically relevant correlation between function or quality of life and component rotation could be found at 5 years. However, it was noted that those patients with combined component malrotation (femoral rotation added to tibial rotation resulting in overall component internal rotation) improved less in overall pain scores than those that were not malrotated. CONCLUSION: In the mid-term, component malrotation may result in a decreased level of improvement from pain compared to pre-operative results. However, component malrotation does not make a significant difference to function or quality of life. LEVEL OF EVIDENCE: Level III: Therapeutic Study.

Body Mass Index Is Associated With All-cause Mortality After THA and TKA.

BACKGROUND: Both obesity and underweight are associated with a higher risk of mortality in adulthood, but the association between mortality after arthroplasty and extreme ranges of body mass index (BMI) have not been evaluated beyond the first year. QUESTIONS/PURPOSES: The purpose of this study was to investigate the association between BMI and all-cause mortality after TKA and THA. METHODS: Data from two arthroplasty registries, the St Vincent's Melbourne Arthroplasty (SMART) Registry from Australia and the Kaiser Permanente Total Joint Replacement Registry (KPTJRR) from the United States, were used to identify patients aged ≥ 18 years undergoing elective TKAs and THAs between January 1, 2002, and December 31, 2013. Same-day bilateral THA and hemiarthroplasties were excluded. All-cause mortality was recorded from the day of surgery to the end of the study (December 31, 2013). Data capture was complete for the SMART Registry. No patients were lost to followup in the KPTJRR cohort and 2959 (5%) THAs and 5251 (5%) TKAs had missing data. Cox proportional hazard regression was used to estimate the all-cause mortality associated with six BMI categories: underweight (< 18.5 kg/m), normal weight (18.5-24.9 kg/m), overweight (25.0-29.9 kg/m), obese class I (30.0-34.9 kg/m), obese class II (35.0-39.9 kg/m), and obese class III (> 40 kg/m). For TKA, the SMART cohort had a median followup of 5 years (range, 0-12 years) and the KPTJRR cohort had a median followup of 4 years (range, 0-12 years). For THA, the SMART cohort had a median followup of 5 years (range, 0-12 years) and the KPTJRR cohort had a median followup of 4 years (range, 0-12 years). RESULTS: In both the Australian and US cohorts, being underweight (Australia: hazard ratio [HR], 3.72; 95% confidence interval [CI], 1.94-7.08; p < 0.001 and United States: HR, 1.88; 95% CI, 1.33-2.64; p < 0.001) was associated with higher all-cause mortality after TKA, whereas obese class I (Australia: HR, 0.66; 95% CI, 0.47-0.92; p = 0.015; United States: HR, 0.71; 95% CI, 0.66-0.78; p < 0.001) or obese class II (Australia: HR, 0.54; 95% CI, 0.35-0.82; p = 0.004; United States: HR, 0.73; 95% CI, 0.66-0.81; p < 0.001) was associated with lower mortality when compared with normal-weight patients. In the US cohort, being overweight was also associated with a lower risk of mortality (HR, 0.76; 95% CI, 0.71-0.82; p < 0.001). In the US cohort, being underweight had a higher risk of mortality after THA (HR, 2.09; 95% CI, 1.65-2.64; p < 0.001), whereas those overweight (HR, 0.73; 95% CI, 0.67-0.80; p < 0.001), obese class I (HR, 0.68; 95% CI, 0.62-0.75; p < 0.001), or obese class II (HR, 0.71; 95% CI, 0.62-0.81; p < 0.001) were at a lower risk of mortality after THA when compared with normal-weight patients. In patients undergoing THA in the Australian cohort, we observed no association between BMI and risk of death. CONCLUSIONS: We found that even severe obesity is not associated with a higher risk of death after arthroplasty. Patients should be informed of this when considering surgery. Clinicians should be cautious when considering total joint arthroplasty in underweight patients without first considering their nutritional status. LEVEL OF EVIDENCE: Level III, therapeutic study.

What Is the Impact of Advancing Age on the Outcomes of Total Hip Arthroplasty?

BACKGROUND: The global demand for total hip arthroplasty (THA) is increasing, underscoring its moniker as the "operation of the century." However, debate still exists as to whether the elderly who undergo the operation achieve the same outcomes as those younger. In this study, we sought to investigate the association between older age and the risks and benefits of THA. METHODS: In this study, we aimed to compare the risks and benefits of THA of those aged ≥80 years vs those <80 years. We analyzed the physical status component of the Short-Form 12 Health Survey, complications within 12 months, all-cause mortality, length of hospital stay (LOS), and discharge to rehabilitation in 2457 cases of primary THA using multivariate modeling. RESULTS: There was no difference in improvement of those older vs the younger group in physical functioning. However, the older group had 2.87 times greater odds of experiencing a post-operative medical complication and 3.49 times the rate of all-cause mortality (P < .001). Additionally, the older group encountered an additional median 0.21-day increase in LOS and had 3.93 times greater odds of being discharged to rehabilitation rather than home (P < .001). We were unable to demonstrate any difference between groups in terms of post-operative surgical or wound-related complications. CONCLUSION: The elderly stand to gain equivalent benefits from THA as those younger in terms of physical functioning. However, this benefit needs to be balanced against the increased risk of post-operative medical complications, increased LOS, increased requirement for rehabilitation, and ultimately the increased risk of mortality.

Gap Balancing Sacrifices Joint-Line Maintenance to Improve Gap Symmetry: 5-Year Follow-Up of a Randomized Controlled Trial.

BACKGROUND: Gap balancing (GB) has been noted to sacrifice joint-line maintenance to improve gap symmetry. This study aims to determine whether this change affects function or quality of life in the midterm. METHODS: A prospective blinded randomized controlled trial was completed with 103 patients randomized to measured resection (n = 52) or GB (n = 51). Primary outcome measured was femoral component rotation. Secondary outcomes measured were joint-line change, gap symmetry, and function and quality-of-life outcomes. RESULTS: At 5 years, 83 of 103 patients (85%) were assessed. There was no significant difference between groups in terms of functional or quality of life outcomes. A subgroup analysis revealed that there was no significant association between those with asymmetrical flexion and/or extension or medial and/or lateral gaps during knee replacement and subsequent functional outcomes. No significant difference was detected with those with an elevated joint line and postoperative function. CONCLUSION: In the midterm, the resultant change in joint-line and maintained gap symmetry noted with GB does not result in significant change to function or quality of life.

In vivo biocompatibility of porous and non-porous polypyrrole based trilayered actuators.

Trilayered polypyrrole (PPy) actuators have high stress density, low modulus and have wide potential biological applications including use in artificial muscles and in limb prosthesis after limb amputation. This article examines the in vivo biocompatibility of actuators in muscle using rabbit models. The actuators were specially designed with pores to encourage tissue in growth; this study also assessed the effect of such pores on the stability of the actuators in vivo. Trilayered PPy actuators were either laser cut with 150 µm pores or left pore-less and implanted into rabbit muscle for 3 days, 2 weeks, 4 weeks and 8 weeks and retrieved subsequently for histological analysis. In a second set of experiments, the cut edges of pores in porous actuator strips were further sealed by PPy after laser cutting to further improve its stability in vivo. Porous actuators with and without PPy sealing of pore edges were implanted intramuscularly for 4 and 8 weeks and assessed with histology. Pore-less actuators incited a mild inflammatory response, becoming progressively walled off by a thin layer of fibrous tissue. Porous actuators showed increased PPy fragmentation and delamination with associated greater foreign body response compared to pore-less actuators. The PPy fragmentation was minimized when the pore edges were sealed off by PPy after laser cutting showing less PPy debris. Laser cutting of the actuators with pores destabilizes the PPy. This can be overcome by sealing the cut edges of the pores with PPy after laser. The findings in this article have implications in future design and manufacturing of PPy actuator for use in vivo.

Using the common sense model of illness to examine interrelationships between symptom severity and health outcomes in end-stage osteoarthritis patients.

OBJECTIVE: The aim was to evaluate the utility of the common sense model (CSM) in characterizing contributors to psychological well-being and quality of life (QoL) in patients with end-stage OA. METHODS: One hundred and twenty patients [34 males, 86 females; mean (s.d.) age 65.52 (9.14) years] with end-stage OA (57.5% hip, 42.5% knee) were recruited. OA symptom severity was evaluated according to the WOMAC; coping styles were assessed with the Carver Brief COPE scale; illness perceptions were explored with the Brief Illness Perceptions Questionnaire; self-efficacy was assessed with the Arthritis Self-efficacy scale; anxiety, depression and overall distress were measured using the Hospital Anxiety and Depression Scale; and QoL was assessed using the WHO Quality of Life-short version. The CSM was used to explore the interrelationships between OA symptom severity, illness perceptions and coping strategies in patients. RESULTS: Two structural equation models were developed, with both found to have good fit. Consistent with the CSM, the standard model indicated that self-reported OA symptom severity directly influenced illness perceptions, which in turn had direct impacts upon maladaptive coping, distress and QoL. The addition of self-efficacy to the CSM resulted in a complex interaction, with OA severity directly influencing self-efficacy and self-efficacy influencing maladaptive coping, distress and QoL. CONCLUSION: We found interrelationships amongst OA activity, illness perceptions, coping strategies, self-efficacy, psychological distress and QoL broadly consistent with the CSM. The CSM may help inform the approach to the psychological support that patients with end-stage OA often require.

Intramedullary nailing has sufficient durability for metastatic femoral fractures.

BACKGROUND: Surgical treatment options of femoral metastases include intramedullary nailing (IMN) and endoprosthetic reconstruction (EPR). Previous studies have demonstrated functional and oncological advantages of EPR over IMN. The purpose of this study was to (1) report the durability of IMN and (2) establish the indication of IMN for femoral metastases. METHODS: In 2003-2013, among 186 surgically treated femoral metastasis cases, we retrospectively reviewed 80 consecutive IMN cases in 75 patients, including 14 pathological and 66 impending fractures. For the decision of surgical procedure (IMN, EPR, or plating), the following factors are considered: (1) fracture pattern (impending or pathological fracture), (2) Mirels' score (≥8 or <8), (3) fracture site (femoral head, neck, intertrochanter, subtrochanter, diaphysis, or distal), (4) number of metastases (solitary or multiple), and (5) patient's estimated prognosis. Patient demographics, postoperative survival, implant survival, and early postoperative mortality were reviewed. RESULTS: The patients were 37 males and 38 females, with a mean age of 60.1 (20-84) years. Average follow-up period was 11.4 (1-77) months. The most common fracture site was the subtrochanter (46/80), followed by the diaphysis (26/80) and the intertrochanter (8/80). The most common primary tumor was lung cancer (24/80, 32%), followed by breast cancer (24%) and melanoma (15%). With the exception of six cases, all patients underwent postoperative radiotherapy to the affected whole femur. The postoperative patient survival was 14.2 and 8.4% at 2 and 3 years from surgery, respectively, while the implant survival rate remained 94.0% at both 2 and 3 years. Three out of 46 subtrochanteric cases required revision surgeries because of proximal breakage of implant 4-50 months after initial surgery for femoral metastases, but all were replaced by mega-prosthesis and did not need further operation until their death. Early postoperative fatal complications were observed in three patients, all of which were pulmonary dysfunction. CONCLUSIONS: The performance of IMN in this study was satisfactory although a large portion of sub- and intertrochanter metastases were included. Broader indication including these parts should be considered, for IMN has advantages such as lower cost and less invasiveness and even an implant failure can be revised by mega-prosthetic reconstruction.

Addressing obesity in the management of knee and hip osteoarthritis - weighing in from an economic perspective.

BACKGROUND: Obesity is one of the only modifiable risk factors for both incidence and progression of Osteoarthritis (OA). So there is increasing interest from a public health perspective in addressing obesity in the management of OA. While evidence of the efficacy of intereventions designed to address obesity in OA populations continues to grow, little is known about their economic credentials. The aim of this study is to conduct a scoping review of: (i) the published economic evidence assessing the economic impact of obesity in OA populations; (ii) economic evaluations of interventions designed to explicitly address obesity in the prevention and management of OA in order to determine which represent value for money. Besides describing the current state of the literature, the study highlights research gaps and identifies future research priorities. METHODS: In July 2014, a search of the peer reviewed literature, published in English, was undertaken for the period January 1975 - July 2014 using Medline Complete (Ebscohost), Embase, Econlit, Global Health, Health Economics Evaluation Database (HEED), all Cochrane Library databases as well as the grey literature using Google and reference lists of relevant studies. A combination of key search terms was used to identify papers assessing the economic impact of obesity in OA or economic evaluations conducted to assess the efficiency of obesity interventions for the prevention or management of OA. RESULTS: 14 studes were identified; 13 were cost burden studies assessing the impact of obesity as a predictor for higher costs in Total Joint Arthroplasty (TJA) patients and one a cost-effectiveness study of an intervention designed to address obesity in the managment of mild to moderate OA patients. CONCLUSION: The majority of the economic studies conducted are cost burden studies. While there is some evidence of the association between severe obesity and excess hospital costs for TJA patients, heterogeneity in studies precludes definitive statements about the strength of the association. With only one economic evaluation to inform policy and practice, there is a need for future research into the cost-effectiveness of obesity interventions designed both for prevention or management of OA along the disease spectrum and over the life course.

Development of a Prognostic Nomogram for Predicting the Probability of Nonresponse to Total Knee Arthroplasty 1 Year After Surgery.

BACKGROUND: Indications for total knee arthroplasty (TKA) currently depend on clinical judgment. Up to one fifth of those who undergo primary TKA do not report a clinically meaningful improvement in pain and function after surgery. Our aim was to develop and internally validate a prognostic tool for predicting the probability of nonresponse to surgery at 12 months. METHODS: Patients from 1 center who underwent primary TKA (N = 615) between 2012 and 2013. The Western Ontario and McMaster Universities Arthritis Index was collected pre- and 12 months after TKA from which nonresponse to surgery was determined using the Outcome Measures in Rheumatology-Osteoarthritis Research Society International responder criteria. Using independent prognostic correlates of postoperative nonresponse observed in adjusted modeling, we derived a prognostic nomogram to estimate the probability of nonresponse to TKA based on this suite of explanatory variables. RESULTS: A total of 90/615 (15%) cases were nonresponders to TKA. The degree of contribution (odds ratio, 95% confidence interval) of each explanatory factor to nonresponse nomogram points was body mass index ≥40 kg/m(2) (3.48; 1.97-6.12), Kellgren and Lawrence <4 (2.59; 1.58-4.24), mental disability on Short Form Health Survey (SF-12) mental component score (3.30; 1.44-7.58), and every 10-point increase in preoperative Western Ontario and McMaster Universities Arthritis Index score (0.81; 0.68-0.97). The concordance index for this model was 0.74. CONCLUSION: We have created a prognostic nomogram that displays the predictive probabilities of nonresponse to TKA as a source of decision support for clinicians and patients, about their likely functional outcome from TKA. Although our own internal validation suggested good nomogram performance, external validation in a comparable surgical population is required to confirm generalizability of the nomogram.