Use of a Tourniquet and Spinal Anesthesia Increases Satisfactory Outcomes After Total Knee Arthroplasty: A Randomized Study

BACKGROUND

Total knee arthroplasty (TKA) is usually performed successfully with or without a tourniquet and under spinal anesthesia (SA) or general anesthesia (GA). However, 10% to 34% of patients experience dissatisfaction and pain after TKA. We aimed to compare the effects of tourniquet use and SA or GA on TKA outcomes.

METHODS

We randomly assigned 404 patients to 4 study groups: SA without a tourniquet (NT/SA), SA with a tourniquet (T/SA), GA without a tourniquet (NT/GA), and GA with a tourniquet (T/GA). The primary outcome was the change in the Oxford Knee Score (OKS) at 1 year postoperatively. Secondary outcomes included a satisfactory TKA outcome assessed using the OKS minimal important change (MIC) and OKS patient acceptable symptom state (PASS), adverse events, and quality of life using the 15-dimensional health-related quality of life tool.

RESULTS

At 1 year, the OKS was obtained for 381 patients. In the 2-group comparisons, the tourniquet did not affect the OKS improvement. The SA group had more substantial improvement in the OKS than the GA group (16.21 compared with 14.08 a mean difference of 2.13; 95% confidence interval [CI], 0.55 to 3.71; p = 0.008). In the 4-group comparisons, the T/SA group had more substantial improvements in the OKS than the NT/GA group (16.87 compared with 13.65, a mean difference of 3.2; 95% CI, 0.28 to 6.17; p = 0.026). The SA group reached the OKS MIC more frequently than the GA group (91.7% compared with 81.7%; odds ratio [OR] = 2.49 [95% CI, 1.32 to 4.69]; p = 0.005). The SA group also reached the OKS PASS more frequently than the GA group (86.0% compared with 75.7%; OR = 2.00 [95% CI, 1.18 to 3.39]; p = 0.010). The T/SA group had significantly more patients reaching the OKS MIC than the NT/GA group (95.7% compared with 79.6%; p = 0.005) and more patients reaching the OKS PASS than the NT/GA group (92.6% compared with 74.5%; p = 0.004). No differences were seen with respect to adverse events in any comparisons.

CONCLUSIONS

The tourniquet had no detrimental effects on the outcomes of TKA. SA had a positive effect on the OKS. The use of SA combined with a tourniquet resulted in the best improvement in OKS and the highest proportion of satisfactory outcomes with TKA.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

The burden of hip and knee osteoarthritis in Finnish occupational healthcare

BACKGROUND

Osteoarthritis (OA) is a leading cause of disability and pain especially among older adults, but it is also known to affect working age individuals, often leading to reduced productivity and increased healthcare usage. The aim of this study was to determine the burden of hip and knee OA in Finnish occupational healthcare.

METHODS

This was a retrospective registry study utilizing the electronic medical records of the largest private and occupational healthcare provider in Finland. All consented patients with hip or knee OA were identified. A subcohort of occupational healthcare (OCH) patients was then compared to an age- and gender-matched control group without OA. Patient demographics including comorbidities were determined and healthcare contacts, medication prescriptions, and sick leaves were compared between the two groups. The study period was from January 1st, 2012 to April 30th, 2020.

RESULTS

51,068 patients with hip or knee OA were identified (all OA cohort) and 35,109 of these formed the occupational healthcare subcohort. Most of the OA patients were female and belonged to the age group 50-59 years. The point prevalence of hip/knee OA at the end of the study period was 5.6% for the occupational healthcare subcohort. OA patients had 2.2 times more healthcare contacts and 2.8 times more overall sick leave days compared to the age- and gender-matched control cohort. Etoricoxib was the most commonly prescribed medication at OA-related visits (21.8% of patients). Opioids were prescribed to 10.6% of patients at OA-related visits and the most prescribed opioid was a combination of codeine and paracetamol (4.8% of patients). 5054 OA patients (14.4%) had a contraindication for non-steroidal anti-inflammatory drugs (NSAIDs).

CONCLUSIONS

This retrospective registry study utilizing real-world data provides new evidence on the disease burden of hip or knee osteoarthritis from the electronic medical records of Finnish occupational healthcare customers. OA patients had more comorbidities, more healthcare contacts, more sick leave days, and more analgesic prescriptions compared to an age- and gender-matched control cohort without OA.

Current evidence from a worldwide, multicentre, follow-up study of the recalled Articular Surface Replacement Hip System

INTRODUCTION

Our first aim was to report the longitudinal clinical performance of patients treated with the ASR Hip System, a metal-on-metal (MoM) device, in their mid- to late-term follow-up. Secondly, we sought to report on the reasons and risk factors for mid- to late-term implant failure.

METHODS

A total of 1721 ASR patients (1933 hips) from 16 centres in 6 countries were enrolled to a prospective, post-recall study. The average time to enrollment was 7.4 years from index surgery. Data from 3 follow-up visits over 2 years were analysed. Implant performance, based on ion levels and PROMs, was determined at each clinical visit.

RESULTS

The proportion of those exhibiting good performance decreased over time for hip resurfacing (ASR HRA) and total hip arthroplasty (ASR XL) patients. ASR XL patients were likely to exhibit longitudinal blood metal ion increases regardless of symptom state. ASR HRA patients were more likely to present with and maintain good performance over time, especially males with high general health indicators. 6% of ASR HRA and 14% of ASR XL patients were revised throughout the study period.

DISCUSSION

ASR XL THA patients are likely to exhibit blood metal ion increases without accompanying changes in symptom state, and therefore should be followed with annual blood tests at minimum. While appropriately selected ASR HRA patients were the most likely to exhibit low blood metal ion levels and report no symptoms, we recommend vigilant follow-up of all ASR patients to ensure that worsening clinical outcomes and asymptomatic soft tissue damage are not missed.

Progression of adverse local tissue reaction in ASR metal-on-metal hip arthroplasty: a longitudinal MARS-MRI study at mid- to long-term

BACKGROUND

Despite the large number of studies assessing adverse local tissue reaction (ALTR) in metal-on-metal (MoM) hip implants, there is still a lack of knowledge about the natural progression of ALTR. The aims of this study were to describe the natural course of changes in ALTR at mid- to long-term follow-up for patients treated with metal-on-metal hip arthroplasty and to determine possible risk factors associated with change in ALTR.

METHODS

A total of 158 patients (158 hips), 109 MoM hip resurfacing arthroplasties (HRAs) and 49 MoM total hip arthroplasties (THAs), with 2 clinical follow-ups including MARS-MRIs were included. The mean time from index operation to the first visit was 7.6 years (range 3.4-11.4 years), and the mean time between the 2 visits was 1.0 year (range 0.7-1.6 years).

RESULTS

The proportion of patients with moderate or severe ALTR did not increase significantly between the first and second visit for the MoM HRA group (14.7-15.6%; p = 0.850) or the MoM THA group (32.7-36.7%; p = 0.671). 8 (7.3%) HRA patients and 9 (18.4%) THA patients progressed in ALTR grade. None of the collected clinical variables was sensitive or specific in identifying patients with ALTR progression.

CONCLUSIONS

Although ALTR prevalence was high in our cohort, clinically significant ALTR progression was rare. We were unable to find any predictors associated with ALTR change. This indicates that MARS-MRI remains a valuable tool in the follow-up of patients treated with MoM hip devices in identifying patients who may need revision surgery.

Intravenous patient-controlled analgesia vs nurse administered oral oxycodone after total knee arthroplasty: a retrospective cohort study

OBJECTIVES

Severe post-operative pain is common after total knee arthroplasty. Patient-controlled analgesia is an alternative method of pain management, whereby a patient administers his or her own pain medication. Patients seem to prefer this method over nurse-administered analgesia. However, it remains unclear whether patients using patient-controlled analgesia devices use higher or lower doses of opioids compared to patients treated with oral opioids.

METHODS

This retrospective study examined 164 patients undergoing total knee arthroplasty. Post-operatively, 82 patients received oxycodone via intravenous patient-controlled analgesia devices, while the pain medication for 82 patients in the control group was administered by nurses. The main outcome measure was the consumption of intravenous opioid equivalents within 24 h after surgery. Secondary outcome measures were the use of anti-emetic drugs and the length of stay. Furthermore, we evaluated opioid-related adverse event reports.

RESULTS

The consumption of opioids during the first 24 h after surgery and the use of anti-emetic drugs were similar in both groups. The median opioid dose of intravenous morphine equivalents was 41.1 mg (interquartile range (IQR): 29.5-69.1 mg) in the patient-controlled analgesia group and 40.5 mg (IQR: 32.4-48.6 mg) in the control group, respectively. The median length of stay was 2 days (IQR: 2-3 days) in the patient-controlled analgesia group and 3 days (IQR: 2-3 days) in the control group (p=0.02). The use of anti-emetic drugs was similar in both groups.

CONCLUSIONS

The administration of oxycodone via intravenous patient-controlled analgesia devices does not lead to increased opioid or anti-emetic consumptions compared to nurse-administered pain medication after total knee arthroplasty. Patient-controlled analgesia might lead to shortened length of stay.

Obesity is not associated with hip failure in patients with articular surface replacement of the hip

BACKGROUND

Our main aim was to investigate whether obese patients were at increased risk of elevated metal ion levels and/or adverse local tissue reaction (ALTR) after being treated with articular surface replacement (ASR) hip arthroplasty.

METHODS

This study included 360 patients who underwent metal-on-metal (MoM) hip resurfacing (HRA) or total hip arthroplasty (THA). 95 patients (26%) were underweight/normal weight (BMI < 25 kg/m²), 139 (39%) were overweight (BMI 25-30 kg/m²), and 126 (36%) were obese (BMI ⩾ 30 kg/m²). Blood metal ion levels and patient-reported outcome measures (PROMs) were obtained, and a sub-cohort of 85 patients had MARS MRI performed. Logistic regression analyses were used to assess the associations between obesity and metal ions, as well as ALTR.

RESULTS

BMI was not associated with either elevated metal ion levels or ALTR. In HRA patients, female gender (OR 3.0; p = 0.019) and pain (OR 2.3; p = 0.046) were associated with elevated Co levels. Female patients had increased risk of elevated Cr levels (OR 3.0; p = 0.02). In THA patients, female gender (OR 2.2; p = 0.004) and VAS satisfaction (OR 2.1; p = 0.01) were associated with elevated Co levels. Female gender (OR 3.6; p = 0.001) and time from surgery (OR 1.4; p = 0.005) were associated with Cr levels. In the sub-cohort, ALTR was associated with Co levels (OR 16.1; p = 0.002) in HRA patients.

CONCLUSION

Patients with BMI ⩾ 30 kg/m² present no increased risk for elevated metal ion levels or development of ALTR.

Reasons and Risk Factors for Delayed Discharge After Total Knee Arthroplasty Using an Opioid-Sparing Discharge Protocol

BACKGROUND

In this study, we aimed to assess the length of hospital stay after total knee arthroplasty in a European healthcare setting. We also aimed to investigate risk factors and reasons for delayed discharge when using an opioid-sparing fast-track protocol.

METHODS

From our institutional database, we retrospectively identified all primary elective unilateral total knee arthroplasties performed during January to December 2015. Both patient-related and surgery-related variables were collected from our databases. Risk factors were analyzed using multivariable logistic regression analysis.

RESULTS

The median length of stay (LOS) was 3 days. Independent risk factors for delayed discharge were higher age, higher American Society of Anesthesiologists score, general anesthesia, surgery performed toward the end of the week, longer duration of surgery, longer stay in the post-anesthesia care unit, and shorter preoperative walking distance. The main reasons for delayed discharge were delayed functional recovery and pain.

CONCLUSION

This study identified several independent risk factors for an LOS longer than 3 days. These risk factors add to the current knowledge on which patients have an increased risk of prolonged LOS, and which patients should be targeted when striving to further reduce the LOS.

Outcomes of Triggering the Emergency Response Team at a High-Volume Arthroplasty Center

BACKGROUND AND AIMS

Emergency Response Teams have been employed by hospitals to evaluate and manage patients whose condition is rapidly deteriorating. In this study, we aimed to assess the outcomes of triggering the Emergency Response Teams at a high-volume arthroplasty center, determine which factors trigger the Emergency Response Teams, and investigate the main reasons for an unplanned intensive care unit admission following Emergency Response Team intervention.

MATERIAL AND METHODS

We gathered data by evaluating all Emergency Response Team forms filled out during a 4-year period (2014-2017), and by assessing the medical records. The collected data included age, gender, time of and reason for the Emergency Response Teams call, and interventions performed during the Emergency Response Teams intervention. The results are reported as percentages, mean ± standard deviation, or median (interquartile range), where appropriate. All patients were monitored for 30 days to identify possible intensive care unit admissions, surgeries, and death.

RESULTS

The mean patient age was 72 (46-92) years and 40 patients (62%) were female. The Emergency Response Teams was triggered a total of 65 times (61 patients). The most common Emergency Response Team call criteria were low oxygen saturation, loss or reduction of consciousness, and hypotension. Following the Emergency Response Team call, 36 patients (55%) could be treated in the ward, and 29 patients (45%) were transferred to the intensive care unit. The emergency that triggered the Emergency Response Teams was most commonly caused by drug-related side effects (12%), pneumonia (8%), pulmonary embolism (8%), and sepsis (6%). Seven patients (11%) died during the first 30 days after the Emergency Response Teams call.

CONCLUSION

Although all 65 patients met the Emergency Response Teams call criteria, potentially having severe emergencies, half of the patients could be treated in the arthroplasty ward. Emergency Response Team intervention appears useful in addressing concerns that can potentially lead to unplanned intensive care unit admission, and the Emergency Response Teams trigger threshold seems appropriate as only 3% of the Emergency Response Teams calls required no intervention.

Promising early outcomes of a novel anatomic knee system

PURPOSE

The primary aim of this study was to report the early clinical and radiographic outcomes of patients who have been treated with total knee arthroplasty (TKA) using the Persona knee system. The secondary aim was to compare patient-reported outcomes (PROs) of the Persona knee system to those of the NexGen implant.

METHODS

A registry-based study of a consecutive series of 112 patients (129 knees) treated with the Persona knee system from a single center was conducted. Preoperative, 1-year, and 2-year radiographs and PROs were analyzed. Postoperative radiographs were assessed for radiolucency and component positioning. Patients were monitored for postoperative complications and revision. Two-year PROs were compared to a 1:1 propensity score-matched cohort of patients treated with the NexGen knee system.

RESULTS

Ninety-five percent of knees were within literature-defined safe ranges of the anatomical tibiofemoral axis, tibial varus/valgus angle, femoral flexion/extension angle, and tibial slope. Radiolucency was observed in 0.9% and 1.3% of knees at one and 2 years, respectively. Two-year PRO values demonstrated clinically meaningful improvements from the preoperative values. The cumulative 2-year percent revision was 3.0% (95% confidence interval 1.9-3.8%); there were no revisions due to implant mechanical failure. Patients treated with the Persona knee system had higher KOOS symptom (p = 0.037) and KOOS QOL (p < 0.001) scores compared to patients with the NexGen knee system.

CONCLUSIONS

This knee design demonstrates excellent clinical outcomes, similar or better than the NexGen knee system, at early follow-up.

LEVEL OF EVIDENCE

III.

Fibular head avulsion fractures accompanying operative treated medial tibial plateau fractures

OBJECTIVE

The aims of this work are to determine how frequently medial tibial plateau fractures are accompanied by fibular head avulsion fractures and evaluate the sensitivity of radiographs detecting them, and also to assess if the presence of fibular fracture is correlated with long-term functional outcome and peroneal nerve damage.

MATERIALS AND METHODS

A retrospective chart review of operated patients with medial tibial plateau fractures at level I trauma center during 2002-2008 was performed. From 63 patients imaged preoperatively, 59 had CT and radiographs, three had only CT, and one only radiograph. The presence and fragment size of fibular fracture were retrospectively evaluated. Body mass index (BMI) and functional outcome measurements (the Modified Lysholm knee score and WOMAC) were available for 46 patients.

RESULTS

Fourteen out of 63 patients (22.2%) had fibular fractures. Of the 59 patients with both CT and radiographs, 12 had fibular fractures, and of these, nine were seen with both modalities and three only in CT. Functional scores were available for ten patients with fibular fracture. Patients with fibular fracture seen on radiographs had a significantly higher score on WOMAC function (26 vs. 7; p = 0.027). The patients with fibular fractures had also higher BMI (p = 0.035). Of the six patients with peroneal nerve damage, 50% had fibular fracture.

CONCLUSIONS

In patients with operatively treated medial tibial plateau fracture, the fibular fractures are relatively common. Detecting it is important, as it may be associated with worse functional scores and peroneal nerve paresis. Some fibular fractures may remain undetected on radiographs, hence preoperative CT is recommended.

Randomised controlled study comparing general and spinal anaesthesia with and without a tourniquet on the outcomes of total knee arthroplasty: study protocol

INTRODUCTION

Total knee arthroplasty is a highly effective treatment for end-stage knee osteoarthritis, and it is usually performed under spinal or general anaesthesia with or without a surgical tourniquet. Some debate about the preferred mode of anaesthesia regarding patient outcomes remains. The aim of this study, which compares general and spinal anaesthesia with and without a tourniquet on the outcomes of total knee arthroplasty, is to determine the optimal type of anaesthesia regimen and assess the effect of a tourniquet on the patient's recovery following total knee arthroplasty.

METHODS AND ANALYSIS

This study is a randomised, controlled, parallel-group, four-arm study comparing spinal and general anaesthesia with and without a tourniquet in 400 patients undergoing fast-track total knee arthroplasty, with a 12-month follow-up. The primary outcome is cumulative intravenous oxycodone consumption by patient-controlled analgesia during the first 24 postoperative hours. Secondary outcomes include postoperative nausea and vomiting, the length of hospital stay, the duration of the surgery, blood loss, demand for surgical unit resources, complications, readmissions, postoperative knee function, range of motion, health-related quality of life, prolonged pain and mortality.

ETHICS AND DISSEMINATION

This study's protocol is in accordance with the declaration of Helsinki. The results of this study will be disseminated in international peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT03364088; Pre-results.

Indications for MARS-MRI in Patients Treated With Articular Surface Replacement XL Total Hip Arthroplasty

BACKGROUND

The purpose of this study was to identify which patient and clinical factors are predictive of adverse local tissue reaction (ALTR) and to use these factors to create a highly sensitive algorithm for indicating metal artifact reduction sequence magnetic resonance imaging (MARS-MRI) in Articular Surface Replacement (ASR) XL total hip arthroplasty patients. Our secondary aim was to compare our algorithm to existing national guidelines on when to take MARS-MRI in metal-on-metal total hip arthroplasty patients.

METHODS

The study consisted of 137 patients treated with unilateral ASR XL implants from a prospective, multicenter study. Patients underwent MARS-MRI regardless of clinical presentation at a mean of 6.2 (range, 3.3-10.4) years from surgery. Univariate and multivariate analyses were conducted to determine which variables were predictive of ALTR. Predictors were used to create an algorithm to indicate MARS-MRI. Finally, we compared our algorithm's ability to detect ALTR to existing guidelines.

RESULTS

We found a visual analog scale pain score ≥2 (odds ratio [OR] = 2.53; P = .023), high blood cobalt (OR = 1.05; P = .023), and male gender (OR = 2.37; P = .034) to be significant predictors of ALTR presence in our cohort. The resultant algorithm achieved 86.4% sensitivity and 60.2% specificity in detecting ALTR within our cohort. Our algorithm had the highest area under the curve and was the only guideline that was significantly predictive of ALTR (P = .014).

CONCLUSION

Our algorithm including patient-reported pain and sex-specific cutoffs for blood cobalt levels could predict ALTR and indicate MARS-MRI in our cohort of ASR XL metal-on-metal patients with high sensitivity.

LEVEL OF EVIDENCE

Level II, diagnostic study.

Indications for MARS-MRI in Patients Treated With Metal-on-Metal Hip Resurfacing Arthroplasty

BACKGROUND

Currently, there are no universally accepted guidelines on when to obtain metal artifact reduction sequence magnetic resonance imaging (MARS-MRI) in metal-on-metal (MoM) hip resurfacing arthroplasty (HRA) patients. Our primary aims were to identify which patient and clinical factors are predictive of adverse local tissue reaction (ALTR) and create an algorithm for indicating MARS-MRI in patients with Articular Surface Replacement (ASR) HRA. The secondary aim was to compare our algorithm to existing guidelines on when to perform MARS-MRI in MoM HRA patients.

METHODS

The study cohort consisted of 182 patients with unilateral ASR HRA from a prospective, multicenter study. Subjects received MARS-MRI at a mean of 7.8 years from surgery, regardless of symptoms. We determined which variables were predictive of ALTR and generated cutoffs for each variable. Finally, we created an algorithm to predict ALTR and indicate MARS-MRI in ASR HRA patients using these cutoffs and compared it to existing guidelines.

RESULTS

We found high blood cobalt (Co) (odds ratio = 1.070; P = .011) and high blood chromium (Cr) (odds ratio = 1.162; P = .002) to be significant predictors of ALTR presence. Our algorithm using a blood Co cutoff of 1.15 ppb and a Cr cutoff of 1.09 ppb achieved 96.6% sensitivity and 35.3% specificity in predicting ALTR, which outperformed the existing guidelines.

CONCLUSION

Blood Co and Cr levels are predictive of ALTR in ASR HRA patients. Our algorithm considering blood Co and Cr levels predicts ALTR in ASR HRA patients with higher sensitivity than previously established guidelines.

Ceramic bearings for total hip arthroplasty are associated with a reduced risk of revision for infection

INTRODUCTION

Periprosthetic joint infection (PJI) is a serious complication after total hip arthroplasty (THA) and bearing material's associations to PJI prevalence is largely unknown. The main purposes of this study were to determine if revision for infection varied depending on the type of bearing surface used in primary THA and to study whether patient or implant related factors had an effect on this variation.

METHODS

A total of 177,237 primary THA procedures from the Australian Registry (AOANJRR) were analysed. 3 bearing surfaces were compared. Metal-on-highly cross-linked polyethylene (MoXP) bearing had been used in 95,129 hips, ceramic-on-highly cross-linked polyethylene (CoXP) in 24,269 hips, and ceramic-on-ceramic (CoC) in 57,839 hips. Revision rates for infection were compared between the 3 groups.

RESULTS

Both MoXP and CoXP had a higher revision rate for infection compared to CoC hips (hazard ratio [HR] 1.46 (1.25, 1.72), p < 0.001) and HR 1.42 (1.15, 1.75), p = 0.001 respectively). Patients aged 70 years or less had a lower revision rate for infection when a CoC bearing was used. This difference was independent of sex, and prostheses selection. No difference was evident if the femoral component was cemented or a head size of 28 mm was used.

DISCUSSION

In this registry-based material, use of a CoC bearing was associated with a lower risk of revision for infection in patients younger than 70 years when cementless femoral components were used. Further studies are needed to verify this finding.

A Consultation Phone Service for Patients With Total Joint Arthroplasty May Reduce Unnecessary Emergency Department Visits

BACKGROUND

Different measures for reducing costs after total joint arthroplasty (TJA) have gained attention lately. At our institution, a free-of-charge consultation phone service was initiated that targeted patients with TJA. This service aimed at reducing unnecessary emergency department (ED) visits and, thus, potentially improving the cost-effectiveness of TJAs. To our knowledge, a similar consultation service had not been described previously. We aimed at examining the rates and reasons for early postdischarge phone calls and evaluating the efficacy of this consultation service.

METHODS

During a 2-month period, we gathered information on every call received by the consultation phone service from patients with TJAs within 90 days of the index TJA procedure. Patients were followed for 2 weeks after making a call to detect major complications and self-initiated ED visits. Data were collected from electronic medical charts regarding age, gender, type of surgery, date of discharge, and length of hospital stay.

RESULTS

We analyzed 288 phone calls. Calls were mostly related to medication (41%), wound complications (17%), and mobilization issues (15%). Most calls were resolved in the phone consultation. Few patients (13%) required further evaluation in the ED. The consultation service failed to detect the need for an ED visit in 2 cases (0.7%) that required further care.

CONCLUSION

The consultation phone service clearly benefitted patients with TJAs. The service reduced the number of unnecessary ED visits and functioned well in detecting patients who required further care. Most postoperative concerns were related to prescribed medications, wound complications, and mobilization issues.

Predictors of osteoarthritis following operative treatment of medial tibial plateau fractures

PURPOSE

To determine factors influencing the development of posttraumatic osteoarthritis (OA) following medial tibial plateau fractures and to evaluate concomitant injuries associated with these fractures.

MATERIALS AND METHODS

A chart review of patients with operatively treated medial tibial plateau fractures admitted to our Level I trauma centre from 2002 to 2008 was performed. Of 63 patients, 41 participated in a clinical and radiographic examination. The mean age was 47 years (range 16-78) and the mean follow-up time was 7.6 (range 4.7-11.7) years. All patients had preoperative computed tomography (CT) scans and postoperative radiographs. At the end of follow-up, standing radiographs, mechanical axis, and CT scans were evaluated.

RESULTS

Of the 41 patients, 24 had no or mild (Kellgren-Lawrence grade 0-2) OA and 17 had severe (grade 3-4) OA. Initial articular depression measured from preoperative CT scans was a significant predictor of OA (median 1.8mm vs 4.5mm, p=0.009). Fracture line extension to the lateral plateau (p=0.68) or fracture comminution (p=0.21) had no effect on the development of posttraumatic OA, nor did articular depression at the end of follow-up (p=0.68) measured from CT scans. Mechanical axis >4° of varus and ≥2mm articular depression or step-off were associated with worse WOMAC pain scores, but did not affect other functional outcome scores. Six patients (10%) had permanent peroneal nerve dysfunction. Ten patients (16%) required LCL reconstruction and nine (14%) ACL avulsions were treated at the time of fracture stabilisation.

CONCLUSIONS

The amount of articular depression measured from preoperative CT scans seems to predict the development of posttraumatic OA, probably reflecting the severity of chondral injury at the time of fracture. Restoration of mechanical axis and articular congruence are important in achieving a good clinical outcome.

The current state of orthopaedic residency in 18 European countries

PURPOSE

The aim of this study was to compare differences in current orthopaedic and trauma training programs across Europe.

METHODS

A questionnaire was sent to the FORTE (Federation of Orthopaedic Trainees in Europe) representatives of 25 different European countries, of which 18 responded. The questionnaire included demographic information and information concerning the structure of the training programs, including duration, selection, and mandatory training requirements.

RESULTS

The number of trainees per specialist varied between countries from a ratio of 1:2 to 1:7. Residency was generally five to six years in all the countries. In more than half of the countries selection was interview-based. Nearly all countries utilized a logbook. About 80% of the participating countries had a final examination. When assessing the components of training it was found that only one country (the United Kingdom) had mandatory minimum requirements for (1) courses, (2) surgical procedures, (3) research and (4) leadership. Nearly 40% of the participating countries had only one or none of these four components as a mandatory training requirement.

CONCLUSIONS

There are many similarities in training programs, but some important differences remain in overall requirements and final qualification. The main limitation of this study was that we were unable to get data from all the European countries. FORTE will continue to serve as a forum for sharing best practices with the ultimate goal of improving and harmonizing the level of orthopaedic training across Europe. Future studies should aim to include further details about training programs as well as to include data from more countries.

Scoring the Current Risk Stratification Guidelines in Follow-up Evaluation of Patients After Metal-on-Metal Hip Arthroplasty: A Proposal for a Metal-on-Metal Risk Score Supporting Clinical Decision-Making

BACKGROUND

In the follow-up evaluation of patients with metal-on-metal (MoM) hip replacements, current evidence suggests that orthopaedic surgeons should avoid reliance on any single investigative tool. Current risk stratification guidelines can be difficult to interpret because they do not provide guidance when there are several risk factors in different groups (high and low risk). To improve the clinical utility of risk stratification guidelines, we designed a scoring system to assess the risk of revision.

METHODS

The study population consisted of 1,709 patients (1,912 hips) enrolled in a multicenter follow-up study of a recalled MoM hip replacement. Eleven scoring criteria were determined on the basis of existing follow-up algorithm recommendations and consisted of patient-related factors, symptoms, clinical status, implant type, metal ion levels, and radiographic imaging results. Forward stepwise logistic regression was conducted to determine the minimum set of predictive variables for the risk of revision and to assign variable weights. The MoM risk score for each hip was then created by averaging the weighted values of each predictive variable.

RESULTS

Receiver operating characteristic curve analysis yielded good discrimination between all revised and unrevised hips, with an area under the curve of 0.82 (p < 0.001). The odds of revision for the group with a high MoM risk score were increased by 5.8-fold (95% confidence interval [CI], 3.1 to 11.0) relative to the moderate risk group and by 21.8-fold (95% CI, 9.9 to 48.0) compared with the low risk group.

CONCLUSIONS

Although the use of MoM hip arthroplasty has been limited since 2010, we continue to be faced with the follow-up and risk assessment of thousands of patients who have not had a revision. As more knowledge about risk stratification is gained, the complexity of the algorithms is expected to increase. We propose the use of the MoM risk score as a tool to aid in the clinical decision-making process.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Medial Calcar Erosion Is Associated With Synovial Thickness in Patients With ASR XL Total Hip Arthroplasty

BACKGROUND

Medial calcar erosion is considered a late finding in patients with severe adverse local tissue reactions (ALTRs) after total hip arthroplasty (THA) with dual modular neck stems. Although calcar erosion has been associated with dual modular neck stems, one would expect similar findings in standard stems owing to analogous corrosion at the taper junction. The aim of this study was to evaluate whether medial calcar erosion is also associated with ALTR in patients with standard stems in metal-on-metal (MoM) THA.

METHODS

A total of 96 patients (108 hips) with MoM THA had radiographs and a magnetic resonance imaging of the hip performed at a mean time of 5.7 years after surgery. Calcar erosion was assessed from radiographs. ALTR Anderson grade, diameter, volume, and synovial thickness were assessed from magnetic resonance imaging.

RESULTS

Calcar erosion was present in 54 hips (50%) and was associated with ALTR synovial thickness but not with Anderson grade, diameter, or volume. Most of the hips with calcar erosion (n = 45) had an ALTR (positive predictive value 0.83, 95% confidence interval 0.70-0.92). The relative risk of having a synovial thickness > 3 mm increased by a factor of 3.0 (95% confidence interval 1.3-6.5) if calcar erosion was observed.

CONCLUSION

Subtle erosions of the medial calcar after MoM THA may be an early indicator of an adverse reaction to wear particles warranting cross-sectional imaging. Synovial thickness may also be more relevant than absolute size in the classification of ALTR severity and collateral tissue damage.

The role of outpatient visit after operative treatment of ankle fractures

It is a common practice that patients have a scheduled follow-up visit with radiographs following ankle fracture surgery. The aim of this study was to evaluate whether an early outpatient visit (<3 weeks) after ankle fracture surgery resulted in a change in patient management. For this study, 878 consecutive operatively treated ankle fracture patients with an early outpatient clinical-radiological visit were reviewed. The outcome measure was a change in treatment plan defined as any procedure, medication, or surgical intervention that is not typically implemented during the uncomplicated healing process of an acute fracture. A change in treatment plan was observed in 9.8% of operatively treated ankle fracture patients. The mean age of the patients was 48 years and the mean follow-up time was 64 months. Of the changes in treatment plan, 91% were exclusively due to clinical findings such as infection. Only three of 878 patients required a change in their treatment plan based merely on the findings of the radiographs taken at the outpatient visit. Only 37% of the patients requiring a change in their postoperative management had solicited an unanticipated visit before the scheduled outpatient visit due to clinical problems such as infection or a cast-related issue. Our study showed that every tenth operatively treated ankle fracture patient requires a change in their treatment plan due to a clinical problem such as infection or a cast-related issue. Although at hospital discharge all patients are provided with written instructions on where to contact if problems related to the operated ankle emerge, only one third of the patients are aware of the clinically alarming symptoms and seek care when problems present. Our findings do not support obtaining routine radiographs at the early outpatient visit in an ankle fracture patient without clinical signs of a complication.

Are Females at Greater Risk for Revision Surgery After Hip Resurfacing Arthroplasty With the Articular Surface Replacement Prosthesis?

BACKGROUND

Female patients undergoing hip resurfacing arthroplasties may be at greater risk of revision surgery than males, but it is unclear whether this is related to sex or other factors. We focused our analysis on data from a prospective multicenter cohort study monitoring the ASR(TM) hip resurfacing arthroplasty prosthesis on the potential association of sex on patient-reported outcome measures (PROMs), metal ion levels, revision surgery, and presence of adverse local tissue reaction. As thousands of patients with the ASR(TM) prosthesis are still undergoing followup it is critical to optimize the protocol for monitoring these patients.

QUESTIONS/PURPOSES

We wished (1) to assess the associations between sex and implant survival, and adverse local tissue reaction; and (2) to report the differences between sexes in metal ion levels and patient-reported outcome measures.

METHODS

One thousand two hundred fifty-two patients (1390 hips) who underwent hip resurfacing arthroplasty with implantation of the ASR(TM) prosthesis from April 2003 to July 2010 were eligible for enrollment in a multicenter followup study of the ASR(TM) Hip Resurfacing System after the voluntary recall of this device was initiated by DePuy in 2010. Nine hundred seventy patients (1098 hips) were enrolled at a mean of 7 years after surgery, with a mean followup of 2 years (range, 1-3.5 years). Nine hundred fifty-eight patients (1084 hips) met the inclusion criteria: ability to provide informed consent, complete PROMs, and continued routine followup. A subset of patients (150 patients, 171 hips), who all were from one center, with annual metal artifact reduction sequence MRI were analyzed. Ninety-three percent of patients from this center had routine MRI performed. The EuroQoL (EQ-5D), Harris hip score (HHS), University of California Los Angeles (UCLA) activity score, VAS pain, radiographs, patient and surgery details, and blood cobalt and chromium levels were obtained. Cox regression analysis was conducted to identify factors associated with implant survival, using any revision as the end point, and presence of adverse local tissue reaction.

RESULTS

In patients who had unilateral surgery, the only variable found to be associated with revision surgery was HHS (hazard ratio [HR], 0.96; 95% CI, 0.94-0.97; p < 0.001). In patients who had bilateral surgery, only HHS (HR, 0.93; 95% CI, 0.90-0.97; p < 0.001) and cobalt level (HR, 1.02; 95% CI, 1.01-1.03; p < 0.001) were associated with risk for revision. In patients with metal artifact reduction sequence MRI, the only variable found to be associated with presence of adverse local tissue reaction was cobalt level (HR, 1.06; 95% CI, 1.02-1.10; p = 0.001). Cobalt and chromium concentrations were greater in female patients than in male patients (cobalt, median 1.89 versus median 1.12 parts per billion [ppb], p < 0.001; chromium, median 2.03 versus median 1.17 ppb, p < 0.001). Slight differences were observed between males and females in HHS (males median 96 versus females median 94, p < 0.001) and UCLA scores (median 8 versus median 6, p < 0.001); however, there was no difference between sexes for VAS pain (median 0.5 versus median 0.5, p = 0.405). Differences were identified between males and females in the distribution of EQ-5D scores, yet the medians were the same (median 1.0 versus median 1.0, p < 0.001).

CONCLUSIONS

Male and female patients who had hip resurfacing arthroplasty with implantation of the ASR(TM) prosthesis should be followed with equal vigilance as both are at similar risk of revision surgery and adverse local tissue reaction. Metal ion levels and HHS should be obtained at followup to monitor for risk of revision and as a screening tool for MRI. Further research is necessary to evaluate if these relationships persist in patients with other metal-on-metal prostheses.

LEVEL OF EVIDENCE

Level II, therapeutic study.

Worse health-related quality of life and hip function in female patients with elevated chromium levels

Background and purpose - Blood metal ion levels can be an indicator for detecting implant failure in metal-on-metal (MoM) hip arthroplasties. Little is known about the effect of bilateral MoM implants on metal ion levels and patient-reported outcomes. We compared unilateral patients and bilateral patients with either an ASR hip resurfacing (HR) or an ASR XL total hip replacement (THR) and investigated whether cobalt or chromium was associated with a broad spectrum of patient outcomes. Patients and methods - From a registry of 1,328 patients enrolled in a multicenter prospective follow-up of the ASR Hip System, which was recalled in 2010, we analyzed data from 659 patients (311 HR, 348 THR) who met our inclusion criteria. Cobalt and chromium blood metal ion levels were measured and a 21-item patient-reported outcome measures (PROMs) questionnaire was used mean 6 years after index surgery. Results - Using a minimal threshold of ≥7 ppb, elevated chromium ion levels were found to be associated with worse health-related quality of life (HRQoL) (p < 0.05) and hip function (p < 0.05) in women. These associations were not observed in men. Patients with a unilateral ASR HR had lower levels of cobalt ions than bilateral ASR HR patients (p < 0.001) but similar levels of chromium ions (p = 0.09). Unilateral ASR XL THR patients had lower chromium and cobalt ion levels (p < 0.005) than bilateral ASR XL THR patients. Interpretation - Chromium ion levels of ≥7 ppb were associated with reduced functional outcomes in female MoM patients.

Risk Factors for Deep Infection Following Plate Fixation of Proximal Tibial Fractures

BACKGROUND

The risk factors are unclear for deep surgical site infection after plate fixation of proximal tibial fractures. The objective of this study was to identify the patient and surgical procedure-related risk factors for infection using established criteria for deep surgical site infection.

METHODS

A total of 655 proximal tibial fractures were treated with open reduction and plate fixation at our center between 2004 and 2013. We identified 34 patients with deep surgical site infection. A control group of 136 patients was randomly selected from the non-infected cohort. Potential risk factors for deep surgical site infection were identified by reviewing surgical, medical, and radiographic records. Independent risk factors for infection were identified from multivariable logistic regression analysis using a stepwise procedure.

RESULTS

The prevalence of deep surgical site infection was 5.2%, the mean age of affected patients was 55 years (range, 16 to 84 years), and 35% of patients were female. Twenty-eight of 34 deep infections were diagnosed within 2 months (acute onset), and only 6 infections were diagnosed >6 months after the index surgical procedure. Nine of the 28 acute-onset infections were treated with antibiotic therapy and debridement. Seventeen patients (50%) required muscle flap coverage, and 5 patients (15%) eventually required above-the-knee amputation. In the multivariable logistic regression analysis with odds ratios (ORs) and 95% confidence intervals (95% CIs), independent predictors of infection were patient age of ≥50 years (OR, 3.6 [95% CI, 1.3 to 10.1]); obesity, defined as a body mass index of ≥30 kg/m(2) (OR, 6.5 [95% CI, 2.2 to 18.9]); alcohol abuse (OR, 6.7 [95% CI, 2.4 to 19.2]); OTA/AO-type-C fracture (OR, 2.8 [95% CI, 1.1 to 7.5]); use of a temporary spanning external fixator (OR, 3.9 [95% CI, 1.4 to 11.1]); and a 4-compartment fasciotomy (OR, 4.5 [95% CI, 1.3 to 15.7]).

CONCLUSIONS

There is high morbidity associated with deep surgical site infection in plated proximal tibial fractures. Patients who are ≥50 years of age, obese patients, those with a history of alcohol abuse, or those with an OTA/AO-type-C fracture are at high risk for infection. Performing a fasciotomy also increases the risk of deep infection and should be implemented with meticulous technique when deemed necessary.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

RSA Applications in Monitoring of Fracture Healing in Clinical Trials

Radiostereometric analysis (RSA) was originally developed as a method for performing highly accurate three-dimensional measurements in vivo over time from sequential radiographs. Since its introduction over twenty years ago, the RSA method has proven itself as a powerful tool with numerous orthopaedic applications. RSA has been used extensively in studies of prosthetic fixation and has been shown to be the method of choice for these studies. RSA has, however, also been successfully applied to a limited number of studies examining fracture healing, namely in fractures of the radius, ankle, tibial plateau, trochanter and femoral neck, as well as studies of bone healing following spinal fusion and tibial osteotomies. RSA follow-up of a fracture will provide definitive demonstration of the exact time of union, i.e. the achievement of fracture stability. This information can be invaluable in randomized clinical trials of fracture treatment. Phantom model studies have proven useful for effective preoperative planning and interpretation of RSA results. The RSA method is a highly accurate, precise and safe objective method for studying fracture healing in clinical trials. The RSA method may serve as a scientific tool to accurately evaluate the significance of supporting novel biomaterials for the early stability and the rate of healing in fractures.

Predictors of Postoperative Wound Necrosis Following Primary Wound Closure of Open Ankle Fractures

BACKGROUND

Most open malleolar ankle fracture wounds can be closed primarily after meticulous debridement. However, the development of wound necrosis following operative treatment of open malleolar ankle fractures can have catastrophic consequences. The aim of this study was to identify risk factors predisposing to postoperative wound necrosis following primary wound closure of open malleolar ankle fractures.

METHODS

A total of 137 patients with open malleolar ankle fractures were identified. The open fracture wound was primarily closed in 110 of 137 (80%) patients, and postoperative wound necrosis occurred in 18 (16%) of these patients. These patients were compared to the open fracture patients without wound necrosis. Twenty possible risk factors for the development of wound necrosis were studied with logistic regression analysis.

RESULTS

The variables that were independently associated with an increased risk for postoperative wound necrosis included ASA class ≥2, Gustilo grade III open injury, and the use of pulsatile lavage at index surgery.

CONCLUSIONS

Our study showed that ASA class ≥2, Gustilo grade III open injury, and the use of pulsatile lavage at index surgery were the most important factors predisposing to postoperative wound necrosis following primary wound closure of open malleolar ankle fractures. The findings warrant a further study specifically comparing primary and delayed wound closure in patients with Gustilo grade III open malleolar ankle fractures and different ASA classes. Also, the role of pulsatile lavage should be re-evaluated.

LEVEL OF EVIDENCE

Level III, retrospective comparative series.

The Symmetry of Adverse Local Tissue Reactions in Patients with Bilateral Simultaneous and Sequential ASR Hip Replacement

The purpose of this study was to evaluate whether patients with bilateral metal-on-metal (MoM) hip replacements have symmetric adverse local tissue reactions (ALTRs) at follow-up. An MRI of both hips was performed at a mean time of six years after surgery in 43 patients. The prevalence and severity of ALTRs were found to be similar in simultaneous hips but differences were observed in sequential hips. The order and timing of sequential hip arthroplasties did not affect the severity of ALTRs. Thus, in addition to metal ion exposure from an earlier MoM implant other factors may also play a role in the progression of ALTRs. Bilateral implants should be given special consideration in risk stratification algorithms for management of patients with MoM hip arthroplasty.

Contemporary demographics and complications of patients treated for open ankle fractures

Open ankle fractures are rare injuries with a high likelihood of wound complications and subsequent infections. There is limited information about the complications and outcomes of these injuries in different age groups. The aim of this study was to assess the contemporary demographics and complications related to this injury. We performed a chart review of all the 3030 patients treated for ankle fractures at a Level 1 trauma centre from 2006 to 2011. 137 (4.5%) patients had an open ankle fracture. The demographic data, injury mechanism, comorbidities, and fracture type were collected. Treatment, complications, length of stay and number of outpatient visits were also recorded. The mean age of the patients was 60 years and 56% were women. Most fractures were Weber type B with a medial sided wound (93%). Only 20% of the fractures were the result of high-energy trauma, and 31% were Gustilo grade III injuries. Immediate internal fixation was performed in 82% of patients, and the wound was primarily closed in most cases (80%). The incidence of postoperative wound necrosis and deep infection was 18% and 17%, respectively. There were more deep infections if pulsatile lavage was used during the wound debridement (p=0.029). About 14 (10%) patients required a flap reconstruction to cover the soft-tissue defect. Every other patient (54%) had a complication, and 21 patients (15%) suffered a long-term disability related to the injury. The number complications did not differ for nighttime and daytime operations (p=0.083). High-energy injuries were more common in younger patients (p<0.001) and these patients also had more lateral sided open wounds than older patients (p=0.002). Interestingly, younger patients also had significantly more complications (p=0.024), suffered more often from chronic pain (p=0.003), and required more flap reconstructions (p=0.026), reoperations (p=0.026), and outpatient clinic visits (p=0.006). Open ankle fractures have a high complication rate and often require multiple surgical procedures. In young patients these injuries are more likely to be the consequence of high-energy trauma leading to more complications and subsequently increased healthcare resource utilisation.

[Complications in ankle fracture surgery]

Ankle fractures are among the most frequently encountered surgically treated fractures. The operative treatment can be associated with several complications such as malreduction and infection. Reinforcing the surgical armamentarium with meticulous preoperative planning together with recognition of common surgical errors are valuable adjuncts in reducing these complications. Furthermore, it is crucial to recognize and address modifiable risk factors for infection so as to minimize this potentially devastating complication. When a deep infection does occur, it is best managed by a multidisciplinary musculosceletal infection team.

The usefulness of MRI and arthroscopy in the diagnosis and treatment of soft-tissue injuries associated with split-depression fractures of the lateral tibial condyle

The role of arthroscopy in the treatment of soft-tissue injuries associated with proximal tibial fractures remains debatable. Our hypothesis was that MRI over-diagnoses clinically relevant associated soft-tissue injuries. This prospective study involved 50 consecutive patients who underwent surgical treatment for a split-depression fracture of the lateral tibial condyle (AO/OTA type B3.1). The mean age of patients was 50 years (23 to 86) and 27 (54%) were female. All patients had MRI and arthroscopy. Arthroscopy identified 12 tears of the lateral meniscus, including eight bucket-handle tears that were sutured and four that were resected, as well as six tears of the medial meniscus, of which five were resected. Lateral meniscal injuries were diagnosed on MRI in four of 12 patients, yielding an overall sensitivity of 33% (95% confidence interval (CI) 11 to 65). Specificity was 76% (95% CI 59 to 88), with nine tears diagnosed among 38 menisci that did not contain a tear. MRI identified medial meniscal injuries in four of six patients, yielding an overall sensitivity of 67% (95% CI 24 to 94). Specificity was 66% (95% CI 50 to 79), with 15 tears diagnosed in 44 menisci that did not contain tears.

MRI appears to offer only a marginal benefit as the specificity and sensitivity for diagnosing meniscal injuries are poor in patients with a fracture. There were fewer arthroscopically-confirmed associated lesions than reported previously in MRI studies.

Cite this article: Bone Joint J 2014;96-B:1631–6.

Flap reconstruction for soft-tissue defects with exposed hardware following deep infection after internal fixation of ankle fractures

The aim of the present study was to determine the outcome for patients treated with flap reconstruction following deep ankle fracture infection with exposed hardware. Out of 3041 consecutive ankle fracture operations in 3030 patients from 2006 to 2011, we identified 56 patients requiring flap reconstruction following deep infection. Thirty-two of these patients could be examined at a follow-up visit. Olerud-Molander Ankle (OMA) score, 15D score, Numeric Rating Scale (NRS), and clinical examination were used to assess the outcome. A total of 58 flap reconstructions were performed in 56 patients with a mean age of 57 years (range 25–93 years) and mean follow-up time of 52 months. The most commonly used reconstruction was a distally based peroneus brevis muscle flap with a split-thickness skin graft. A microvascular free flap was required in only one patient. 22 (39%) patients required subsequent surgical interventions because of a flap-related complication. With flap reconstruction, hardware could eventually be salvaged in 53% of patients with a non-consolidated fracture. The mean OMA score was fair or poor in 53% of the patients, and only 56% had recovered their pre-injury level of function. Half of the patients had shoe wear limitations. The 15D score showed a significantly poorer health-related quality of life compared to an age-standardised sample of the general population. The mean pain NRS was 2.1 (range 0–6), and the mean satisfaction NRS was 6.6 (range 0–10). Our study showed that successful treatment of a soft-tissue defect with exposed hardware following ankle fracture infections can be achieved with local flaps. Despite eventual reconstructive success, complications are common. Patients perceive a poorer health-related quality of life, have shoe wear limitations, and only half of them achieve their pre-injury level of function.

Adherence of hip and knee arthroplasty studies to RSA standardization guidelines. A systematic review

BACKGROUND AND PURPOSE

Guidelines for standardization of radiostereometry (RSA) of implants were published in 2005 to facilitate comparison of outcomes between various research groups. In this systematic review, we determined how well studies have adhered to these guidelines.

METHODS

We carried out a literature search to identify all articles published between January 2000 and December 2011 that used RSA in the evaluation of hip or knee prosthesis migration. 2 investigators independently evaluated each of the studies for adherence to the 13 individual guideline items. Since some of the 13 points included more than 1 criterion, studies were assessed on whether each point was fully met, partially met, or not met.

RESULTS

153 studies that met our inclusion criteria were identified. 61 of these were published before the guidelines were introduced (2000-2005) and 92 after the guidelines were introduced (2006-2011). The methodological quality of RSA studies clearly improved from 2000 to 2011. None of the studies fully met all 13 guidelines. Nearly half (43) of the studies published after the guidelines demonstrated a high methodological quality and adhered at least partially to 10 of the 13 guidelines, whereas less than one-fifth (11) of the studies published before the guidelines had the same methodological quality. Commonly unaddressed guideline items were related to imaging methodology, determination of precision from double examinations, and also mean error of rigid-body fitting and condition number cutoff levels.

INTERPRETATION

The guidelines have improved methodological reporting in RSA studies, but adherence to these guidelines is still relatively low. There is a need to update and clarify the guidelines for clinical hip and knee arthroplasty RSA studies.

Factors predicting the development of early osteoarthritis following lateral tibial plateau fractures: mid-term clinical and radiographic outcomes of 73 operatively treated patients

Background and Aims:

The indications for operative treatment of lateral tibial plateau fractures are still controversial. The objective of this study was to determine whether residual articular surface depression and valgus malalignment of plated lateral tibial plateau fractures at medium-term follow-up affect the clinical and radiographic outcomes.

Material and Methods:

A chart review of patients with operatively treated (AO type B3.1) tibial plateau fractures that were admitted to our level I trauma center between 2002 and 2008 was performed. Out of 123 patients, 73 were available to participate in a clinical and radiographic follow-up examination. The mean follow-up time was 54 months. Patients were clinically assessed and completed the Lysholm knee score and Western Ontario and McMaster Universities Osteoarthritis Index. Maximal articular surface depression, radiological mechanical axis, and degree of posttraumatic osteoarthritis were evaluated from standing radiographs.

Results:

Patients with valgus malalignment of 5° or greater at follow-up developed more advanced osteoarthritis (Kellgren–Lawrence grade 3–4) than patients with a normal mechanical axis (p = 0.006). Similarly, patients with articular depression greater than 2 mm at follow-up also developed more advanced osteoarthritis compared to patients with a depression of 2 mm or less (p = 0.001). The degree of valgus malalignment or articular depression had no effect on the Western Ontario and McMaster Universities Osteoarthritis Index or Lysholm scores.

Conclusions:

The postoperative articular congruity and normal mechanical axis of the lower leg after plate fixation in lateral tibial plateau fractures seem to have a role in prevention of posttraumatic osteoarthritis but does not appear to predict clinical outcome at medium-term follow-up. The role of initial dislocation and associated cartilage damage in the development of osteoarthritis following these fractures is still unknown.

A comprehensive analysis of patients with malreduced ankle fractures undergoing re-operation

PURPOSE

The present study aimed to determine the most common surgical errors resulting in early re-operation following ankle fracture surgery.

METHODS

We performed a chart review to determine the most common types of malreductions that led to early re-operation following ankle fracture surgery. From 2002 to 2011, we identified 5,123 consecutive ankle fracture operations in 5,071 patients. Seventy-nine patients (1.6%) which underwent re-operation due to malreduction detected in postoperative radiographs. These patients were compared with an equal number of age- and sex-matched controls which did not need further surgery.

RESULTS

The most common indication for re-operation was syndesmotic malreduction (47 of 79 patients, 59%). Four main types of errors related to syndesmotic reduction or fixation were identified, with the most common being fibular malpositioning within the tibiofibular incisura. Other indications for re-operation were fibular shortening and malreduction of the medial malleolus. Fracture dislocation, fracture type, posterior malleolar fracture, associated medial malleolar fracture, duration of index surgery, and fixation of an associated medial malleolar fracture with other than two parallel screws were also associated with re-operation. Correction of the malreduction was successfully achieved in the majority (84%) of cases needing further surgery.

CONCLUSION

Early re-operation after ankle fracture surgery was most commonly caused by errors related to syndesmotic reduction or failure to restore fibular length. In the majority of cases, postoperative malreduction was successfully corrected in the acute setting.

Risk factors for deep surgical site infection following operative treatment of ankle fractures

BACKGROUND

Surgical site infection is one of the most common complications following ankle fracture surgery. These infections are associated with substantial morbidity and lead to increased resource utilization. Identification of risk factors is crucial for developing strategies to prevent these complications.

METHODS

We performed an age and sex-matched case-control study to identify patient and surgery-related risk factors for deep surgical site infection following operative ankle fracture treatment. We identified 1923 ankle fracture operations performed in 1915 patients from 2006 through 2009. A total of 131 patients with deep infection were identified and compared with an equal number of uninfected control patients. Risk factors for infection were determined with use of conditional logistic regression analysis.

RESULTS

The incidence of deep infection was 6.8%. Univariate analysis showed diabetes (odds ratio [OR] = 2.2, 95% confidence interval [CI] = 1.0, 4.9), alcohol abuse (OR = 3.8, 95% CI = 1.6, 9.4), fracture-dislocation (OR = 2.0, 95% CI = 1.2, 3.5), and soft-tissue injury (a Tscherne grade of ≥1) (OR = 2.6, 95% CI = 1.3, 5.3) to be significant patient-related risk factors for infection. Surgery-related risk factors were suboptimal timing of prophylactic antibiotics (OR = 1.9, 95% CI = 1.0, 3.4), difficulties encountered during surgery, (OR = 2.1, 95% CI = 1.1, 4.0), wound complications (OR = 4.8, 95% CI = 1.6, 14.0), and fracture malreduction (OR = 3.4, 95% CI = 1.3, 9.2). Independent risk factors for infection identified by multivariable analyses were tobacco use (OR = 3.7, 95% CI = 1.6, 8.5) and a duration of surgery of more than ninety minutes (OR = 2.5, 95% CI = 1.1, 5.7). Cast application in the operating room was independently associated with a decreased infection rate (OR = 0.4, 95% CI = 0.2, 0.8).

CONCLUSIONS

We identified several modifiable risk factors for deep surgical site infection following operative treatment of ankle fractures.

[Posterior dislocation of the sternoclavicular joint]

Posterior dislocation of the sternoclavicular joint is a rare injury. It can be associated with life-threatening complications. Computed tomography is the imaging modality of choice with which possible associated injuries can be detected. Acute injuries are managed with closed reduction under general anaesthesia. A fracture-dislocation is inherently more unstable than an isolated dislocation. Surgical treatment is advocated in cases of delayed diagnosis or failed closed reduction. With early diagnosis and treatment, the long-term outcome of this injury is good.

Dislocation of hip hemiarthroplasty following posterolateral surgical approach: a nested case-control study

PURPOSE

Hip hemiarthroplasty dislocation is a serious complication in treatment of displaced intracapsular hip fractures. We investigated factors associated with an increased risk of dislocation after cemented hip hemiarthroplasty following the posterolateral approach.

METHODS

Between January 2002 and December 2008, 602 hip fractures were treated with cemented unipolar hip hemiarthroplasty. A registry-based analysis was carried out to determine the total number of hemiarthroplasty dislocations in these patients. A control group of 96 patients without dislocation was randomly selected. Logistic regression analysis was performed to evaluate clinical and operative factors associated with dislocation.

RESULTS

Thirty-four patients (5.6%) experienced at least one dislocation. Most were the result of a fall and occurred within two months after surgery. There was a trend for increased dislocation in patients who had been operated on more than 48 hours after admission and in patients who had a longer operative time. Smaller centre-edge angle and hip offset were observed in patients with dislocation. Recurrent dislocation was a significant problem, as 18 patients (62%) experienced multiple dislocations.

CONCLUSIONS

The risk of hemiarthroplasty dislocation following the posterolateral surgical approach may be reduced by prompt surgical treatment and fall prevention in the early postoperative period. Patients with smaller acetabular coverage seem more predisposed to dislocation after the posterolateral approach and may be more suitable for other surgical approaches.

Three-dimensional computer simulation of radiostereometric analysis (RSA) in distal radius fractures

Physical phantom models have conventionally been used to determine the accuracy and precision of radiostereometric analysis (RSA) in various orthopaedic applications. Using a phantom model of a fracture of the distal radius it has previously been shown that RSA is a highly accurate and precise method for measuring both translation and rotation in three-dimensions (3-D). The main shortcoming of a physical phantom model is its inability to mimic complex 3-D motion. The goal of this study was to create a realistic computer model for preoperative planning of RSA studies and to test the accuracy of RSA in measuring complex movements in fractures of the distal radius using this new model. The 3-D computer model was created from a set of tomographic scans. The simulation of the radiographic imaging was performed using ray-tracing software (POV-Ray). RSA measurements were performed according to standard protocol. Using a two-part fracture model (AO/ASIF type A2), it was found that for simple movements in one axis, translations in the range of 25microm-2mm could be measured with an accuracy of +/-2microm. Rotations ranging from 16 degrees to 2 degrees could be measured with an accuracy of +/-0.015 degrees . Using a three-part fracture model the corresponding values of accuracy were found to be +/-4microm and +/-0.031 degrees for translation and rotation, respectively. For complex 3-D motion in a three-part fracture model (AO/ASIF type C1) the accuracy was +/-6microm for translation and +/-0.120 degrees for rotation. The use of 3-D computer modelling can provide a method for preoperative planning of RSA studies in complex fractures of the distal radius and in other clinical situations in which the RSA method is applicable.

Accuracy and precision of radiostereometric analysis in the measurement of three-dimensional micromotion in a fracture model of the distal radius

The purpose of the current study was to verify the feasibility of radiostereometric analysis (RSA) in monitoring three-dimensional fracture micromotion in fractures of the distal radius. The experimental set-up consisted of a simulated model of an extra-articular Colles' fracture, including metallic beads inserted into the bone on either side of the fracture site. The model was rigidly fixed to high precision micrometer stages allowing controlled translation in three axes and rotation about the longitudinal and transverse axes. The whole construct was placed inside a RSA calibration cage with two perpendicular radiographic film cassettes. Accuracy was calculated as the 95% prediction intervals from the regression analyses between the micromotion measured by RSA and actual displacements measured by micrometers. Precision was determined as the standard deviation of five repeated measurements of a 200 microm displacement or a 0.5 degrees rotation along a specific axis. Translations from 25 microm to 5mm were measured with an accuracy of +/-6 microm and translations of 200 microm were measured with a precision of 2-6 microm. Rotations ranging from 1/6 degrees to 2 degrees were measured with an accuracy of +/-0.073 degrees and rotations of 1/2 degrees were measured with a precision of 0.025 degrees -0.096 degrees . The number of markers and their configuration had greater impact on the accuracy and precision of rotation than on those of translation. Aside from the unknown rate of clinical marker loosening, the current results favor the use of at least four markers in each bone fragment in distal radius fractures. These results suggest a strong rationale for the use of RSA as an objective tool for comparing different treatment modalities and novel bone graft substitutes aimed at stabilization of fractures of the distal radius.

Semicarbazide sensitive amine oxidase overexpression has dual consequences: insulin mimicry and diabetes-like complications

Semicarbazide-sensitive amine oxidases (SSAO) are copper-containing enzymes that oxidatively deaminate primary amines to produce hydrogen peroxide, ammonium, and specific aldehydes. Vascular adhesion protein-1 (VAP-1) is a cell surface and soluble molecule that possesses SSAO activity. VAP-1 protein, SSAO activity, and SSAO reaction products are elevated in the serum of patients with diabetes, congestive heart failure, and specific inflammatory liver diseases. By expressing human VAP-1/SSAO on mouse endothelial cells and subsequently in the serum, and by chronically treating the transgenic mice for 15 months with a high-fat diet and a physiological substrate for SSAO, methylamine, the in vivo roles of SSAO were assessed. The VAP-1 transgene increased the mouse body mass index and subcutaneous abdominal fat pad weights in a manner independent of food consumption. The transgene together with increased SSAO substrate availability enhanced glucose uptake in an SSAO-dependent manner. The increased SSAO activity also led to diabetes-like complications, including advanced glycation end product formation, elevated blood pressure, altered atherosclerosis progression, and nephropathy. These findings suggest that, although manipulation of VAP-1/SSAO has potential to serve as a therapeutic treatment in insulin-resistant conditions, care must be taken to fully understand its impact on obesity and vascular damage.

Multiple elements of the allergic arm of the immune response modulate autoimmune demyelination

Analysis of mRNA from multiple sclerosis lesions revealed increased amounts of transcripts for several genes encoding molecules traditionally associated with allergic responses, including prostaglandin D synthase, histamine receptor type 1 (H1R), platelet activating factor receptor, Ig Fc epsilon receptor 1 (Fc epsilon RI), and tryptase. We now demonstrate that, in the animal model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE), mediated by T helper 1 (Th1) T cells, histamine receptor 1 and 2 (H1R and H2R) are present on inflammatory cells in brain lesions. Th1 cells reactive to myelin proteolipid protein expressed more H1R and less H2R than Th2 cells. Pyrilamine, an H1R antagonist, blocked EAE, and the platelet activating factor receptor antagonist CV6209 reduced the severity of EAE. EAE severity was also decreased in mice with disruption of the genes encoding Ig Fc gamma RIII or both Fc gamma RIII and Fc epsilon RI. Prostaglandin D synthase and tryptase transcripts were elevated in EAE brain. Taken together, these data reveal extensive involvement of elements of the immune response associated with allergy in autoimmune demyelination. The pathogenesis of demyelination must now be viewed as encompassing elements of both Th1 responses and "allergic" responses.