Effect of head size and rotation on taper corrosion in a hip simulator

Aims This study investigates head-neck taper corrosion with varying head size in a novel hip simulator instrumented to measure corrosion related electrical activity under torsional loads. Methods In all, six 28 mm and six 36 mm titanium stem-cobalt chrome head pairs with polyethylene sockets were tested in a novel instrumented hip simulator. Samples were tested using simulated gait data with incremental increasing loads to determine corrosion onset load and electrochemical activity. Half of each head size group were then cycled with simulated gait and the other half with gait compression only. Damage was measured by area and maximum linear wear depth. Results Overall, 36 mm heads had lower corrosion onset load (p = 0.009) and change in open circuit potential (OCP) during simulated gait with (p = 0.006) and without joint movement (p = 0.004). Discontinuing gait’s joint movement decreased corrosion currents (p = 0.042); however, wear testing showed no significant effect of joint movement on taper damage. In addition, 36 mm heads had greater corrosion area (p = 0.050), but no significant difference was found for maximum linear wear depth (p = 0.155). Conclusion Larger heads are more susceptible to taper corrosion; however, not due to frictional torque as hypothesized. An alternative hypothesis of taper flexural rigidity differential is proposed. Further studies are necessary to investigate the clinical significance and underlying mechanism of this finding

Wound irrigation does not affect healthrelated quality of life after open fractures: Results of a randomized controlled trial

© 2018 Sprague et al. Aims The Fluid Lavage in Open Fracture Wounds (FLOW) trial was a multicentre, blinded, randomized controlled trial that used a 2 3 factorial design to evaluate the effect of irrigation solution (soap versus normal saline) and irrigation pressure (very low versus low versus high) on health-related quality of life (HRQL) in patients with open fractures. In this study, we used this dataset to ascertain whether these factors affect whether HRQL returns to pre-injury levels at 12-months post-injury. Patients and Methods Participants completed the Short Form-12 (SF-12) and the EuroQol-5 Dimensions (EQ-5D) at baseline (pre-injury recall), at two and six weeks, and at three, six, nine and 12-months postfracture. We calculated the Physical Component Score (PCS) and the Mental Component Score (MCS) of the SF-12 and the EQ-5D utility score, conducted an analysis using a multilevel generalized linear model, and compared differences between the baseline and 12- month scores. Results We found no clinically important differences between irrigating solutions or pressures for the SF-12 PCS, SF-12 MCS and EQ-5D. Irrespective of treatment, participants had not returned to their pre-injury function at 12-months for any of the three outcomes (p \u3c 0.001). Conclusion Neither the composition of the irrigation solution nor irrigation pressure applied had an effect on HRQL. Irrespective of treatment, patients had not returned to their pre-injury HRQL at 12 months post-fracture

What predicts health-related quality of life for patients with displaced femoral neck fractures managed with arthroplasty?: A secondary analysis of the HEALTH trial

Background: Total hip arthroplasty (THA) has been argued to improve health-related quality of life (HRQoL) and function in femoral neck fracture patients compared with hemiarthroplasty (HA). The HEALTH trial showed no clinically important functional advantages of THA over HA. The current analysis explores factors associated with HRQoL and function in this population. Methods: Using repeated measures regression, we estimated the association between HRQoL and function [Short Form-12 (SF-12) physical component score (PCS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) function score] and 23 variables. Results: THA as compared to monopolar HA, but not bipolar HA, was more likely to improve PCS scores (adjusted mean difference [AMD] 1.88 points, P = 0.02), whereas higher American Society of Anesthesiologists score (AMD -2.64, P < 0.01), preoperative use of an aid (AMD -2.66, P < 0.01), and partial weight-bearing status postoperatively (AMD -1.38, P = 0.04) demonstrated less improvement of PCS scores over time. THA improved WOMAC function scores over time compared with monopolar HA (but not bipolar HA) (AMD -2.40, P < 0.01), whereas higher American Society of Anesthesiologists classification (AMD 1.99, P = 0.01) and preoperative use of an aid (AMD 5.39, P < 0.01) were associated with lower WOMAC function scores. Preoperative treatment for depression was associated with lower functional scores (AMD 7.73, P < 0.01). Conclusion: Patients receiving THA are likely to receive small and clinically unimportant improvements in health utility and function compared with those receiving monopolar HA and little improvement compared with those receiving bipolar HA. Patient-specific characteristics seem to play a larger role in predicting functional improvement among femoral neck fracture patients.Orthopaedics, Trauma Surgery and Rehabilitatio

External fixation compared to intramedullary nailing of tibial fractures in the rat

Background and purpose It is not known whether there is a difference in bone healing after external fixation and after intramedullary nailing. We therefore compared fracture healing in rats after these two procedures

What Predicts Health-Related Quality of Life for Patients With Displaced Femoral Neck Fractures Managed With Arthroplasty? A Secondary Analysis of the HEALTH Trial

BACKGROUND: Total hip arthroplasty (THA) has been argued to improve health-related quality of life (HRQoL) and function in femoral neck fracture patients compared with hemiarthroplasty (HA). The HEALTH trial showed no clinically important functional advantages of THA over HA. The current analysis explores factors associated with HRQoL and function in this population. METHODS: Using repeated measures regression, we estimated the association between HRQoL and function [Short Form-12 (SF-12) physical component score (PCS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) function score] and 23 variables. RESULTS: THA as compared to monopolar HA, but not bipolar HA, was more likely to improve PCS scores (adjusted mean difference [AMD] 1.88 points, P = 0.02), whereas higher American Society of Anesthesiologists score (AMD -2.64, P < 0.01), preoperative use of an aid (AMD -2.66, P < 0.01), and partial weight-bearing status postoperatively (AMD -1.38, P = 0.04) demonstrated less improvement of PCS scores over time. THA improved WOMAC function scores over time compared with monopolar HA (but not bipolar HA) (AMD -2.40, P < 0.01), whereas higher American Society of Anesthesiologists classification (AMD 1.99, P = 0.01) and preoperative use of an aid (AMD 5.39, P < 0.01) were associated with lower WOMAC function scores. Preoperative treatment for depression was associated with lower functional s

Surgical preferences of patients at risk of hip fractures: hemiarthroplasty versus total hip arthroplasty

BACKGROUND: The optimal treatment of displaced femoral neck fractures in patients over 60 years is controversial. While much research has focused on the impact of total hip arthroplasty (THA) and hemiarthroplasty (HA) on surgical outcomes, little is known about patient preferences for either alternative. The purpose of this study was to elicit surgical preferences of patients at risk of sustaining hip fracture using a novel decision board. METHODS: We developed a decision board for the surgical management of displaced femoral neck fractures presenting risks and outcomes of HA and THA. The decision board was presented to 81 elderly patients at risk for developing femoral neck fractures identified from an osteoporosis clinic. The participants were faced with the scenario of sustaining a displaced femoral neck fracture and were asked to state their treatment option preference and rationale for operative procedure. RESULTS: Eighty-five percent (85%) of participants were between the age of 60 and 80 years; 89% were female; 88% were Caucasian; and 49% had some post-secondary education. Ninety-three percent (93%; 95% confidence interval [CI], 87-99%) of participants chose THA as their preferred operative choice. Participants identified several factors important to their decision, including the perception of greater walking distance (63%), less residual pain (29%), less reoperative risk (28%) and lower mortality risk (20%) with THA. Participants who preferred HA (7%; 95% CI, 1-13%) did so for perceived less invasiveness (50%), lower dislocation risk (33%), lower infection risk (33%), and shorter operative time (17%). CONCLUSION: The overwhelming majority of patients preferred THA to HA for the treatment of a displaced femoral neck fracture when confronted with risks and outcomes of both procedures on a decision board

Central coordination as an alternative for local coordination in a multicenter randomized controlled trial: the FAITH trial experience

Contains fulltext : 110505.pdf (publisher's version ) (Open Access)BACKGROUND: Surgeons in the Netherlands, Canada and the US participate in the FAITH trial (Fixation using Alternative Implants for the Treatment of Hip fractures). Dutch sites are managed and visited by a financed central trial coordinator, whereas most Canadian and US sites have local study coordinators and receive per patient payment. This study was aimed to assess how these different trial management strategies affected trial performance. METHODS: Details related to obtaining ethics approval, time to trial start-up, inclusion, and percentage completed follow-ups were collected for each trial site and compared. Pre-trial screening data were compared with actual inclusion rates. RESULTS: Median trial start-up ranged from 41 days (P25-P75 10-139) in the Netherlands to 232 days (P25-P75 98-423) in Canada (p = 0.027). The inclusion rate was highest in the Netherlands; median 1.03 patients (P25-P75 0.43-2.21) per site per month, representing 34.4% of the total eligible population. It was lowest in Canada; 0.14 inclusions (P25-P75 0.00-0.28), representing 3.9% of eligible patients (p < 0.001). The percentage completed follow-ups was 83% for Canadian and Dutch sites and 70% for US sites (p = 0.217). CONCLUSIONS: In this trial, a central financed trial coordinator to manage all trial related tasks in participating sites resulted in better trial progression and a similar follow-up. It is therefore a suitable alternative for appointing these tasks to local research assistants. The central coordinator approach can enable smaller regional hospitals to participate in multicenter randomized controlled trials. Circumstances such as available budget, sample size, and geographical area should however be taken into account when choosing a management strategy. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00761813

Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo