The Relationship Between Frailty and Functional Outcomes, Range of Motion, and Reoperation After Reverse Total Shoulder Arthroplasty for Proximal Humerus Fracture.

The objective of this study was to investigate whether frailty is associated with functional outcomes, motion, and reoperation at a minimum of 2 years after reverse total shoulder arthroplasty (rTSA) for proximal humerus fracture. We performed a retrospective study of 153 patients who underwent rTSA for proximal humerus fracture at two level 1 trauma centers from 2003 to 2018 with minimum 2-year follow-up. Frailty was assessed using the modified 5-item frailty index (mFI). The primary outcome variable was the American Shoulder and Elbow Surgeons (ASES) shoulder score at minimum 2-year follow-up. The secondary outcome variables were the Shoulder Pain and Disability Index (SPADI), the Shoulder Subjective Value (SSV), the 0 to 10 numeric rating scale (NRS) pain score, surgical complication, and reoperation. Bivariate comparisons were made between mFI and outcome variables. The mean age of the 153 patients was 70 years, and 76% were women. Forty patients (26%) had a mFI score of 0, 65 patients (42%) had a mFI score of 1, 40 patients (26%) had a mFI score of 2, and 8 patients (5%) had a mFI score of 3. Twenty-seven patients (18%) had complications, and 21 patients (14%) underwent reoperation. At minimum 2-year follow-up, mFI was not associated with ASES shoulder score, SPADI, SPADI pain or disability subscales, SSV, NRS pain score, active and passive shoulder forward flexion, abduction, and external rotation, complication, or reoperation. Provided they survive the initial physiologic insults of trauma and surgery, patients with higher mFI scores treated with rTSA for proximal humerus fracture can expect similar medium-term restoration of shoulder function. [Orthopedics. 2023;46(5):274-279.].

Complications After Open Reduction and Internal Fixation for Distal Radius Fractures in Patients With and Without Rheumatoid Arthritis.

PURPOSE: Rheumatoid arthritis (RA) can have severe impact on patients' functional abilities and increase the risk of fragility fractures. Little is known about how patients with RA fare after operative management of distal radius fractures. The purpose of this study was to compare postoperative complications after surgical fixation in patients with RA and controls, hypothesizing that patients with RA would have higher levels of postoperative complications. METHODS: Patients were identified using Current Procedural Terminology and International Classification of Diseases, Ninth and Tenth Revision, codes for open treatment of distal radius fractures and RA at 3 level 1 trauma centers over a 5-year period (2015-2019). Chart abstraction provided details regarding injuries and treatment. Age- and sex-matched controls were identified in a 2:1 ratio. Postoperative complications were classified according to the Clavien-Dindo-Sink classification system and divided into early (less than 90 days) and late groups. RESULTS: Sixty-four patients (21 with RA and 43 controls) were included. The patients were predominantly women, with a mean age of 62 years and a mean Charlson comorbidity index of 2.1. The RA medications at the time of injury included conventional synthetic disease-modifying antirheumatic drugs (5/21), biologic disease-modifying antirheumatic drugs (5/21), or chronic oral prednisone (6/21). Rheumatoid medications, except hydroxychloroquine, were withheld for 2-3 weeks after surgery. Rheumatoid patients were significantly more likely to sustain a complication compared with the control group, although this was no longer significant on adjusted analysis. Class I complications were the most common. The incidence of early versus late complications was similar between the groups. A high rate of early return to surgery for fixation failure occurred in the RA group compared with none in the control group. CONCLUSIONS: Patients with RA undergoing operative management of distal radius fractures are at risk of postoperative complications, particularly fracture fixation failure, necessitating return to the operative room. High levels of pain, stiffness, and mechanical symptoms were noted in the RA group. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.

Effects of Economic Well-Being on Outcomes at One Year after Volar Plate Fixation of Distal Radius Fractures.

Background: The objective of this study was to determine whether economic well-being is associated with patient-reported functional outcomes and range of motion 1 year following volar plate fixation of distal radius fracture. Methods: A retrospective study was performed on 200 patients with distal radius fractures treated with volar plate fixation at two Level 1 trauma centres from 2006 to 2017 with 1-year clinical follow-up using a previously published cohort. The economic well-being of patients was assessed using the Distressed Communities Index (DCI). Our outcome variables were patient-reported functional outcomes assessed by QuickDASH score and wrist and forearm range of motion 1 year after surgery. The analysis of variance (ANOVA) test was used to compare outcome variables across pre-established tiers of economic well-being. Results: The mean QuickDASH score at 1 year following distal radius fracture volar plate fixation was 10.8 and ranged from 7.3 to 12.2 across tiers of economic well-being. QuickDASH score and wrist range of motion were not significantly different across all tiers of economic well-being. However, wrist flexion-extension arc at 1 year following surgery was significantly decreased in the economically at-risk group compared with the remaining cohort. Conclusions: Patient-reported functional outcomes 1 year after volar plate fixation of distal radius fracture are similar across tiers of economic well-being. Economically disadvantaged patients are at risk for poorer wrist motion following distal radius fracture surgery, though it is not clear if this difference is clinically significant. Level of Evidence: Level II (Prognostic).

Risk Factors for Implant Removal After Surgical Fixation of Midshaft Clavicle Fractures.

Midshaft clavicle fractures are common injuries that traditionally have been managed nonoperatively. However, recent literature has shown lower rates of nonunion and improved patient-reported outcomes with surgical management. The rate of implant removal after surgical fixation varies across the literature from 5% to 82%, depending on the method of fixation. We performed a retrospective review of all patients who underwent open reduction and internal fixation (ORIF) with plate-and-screw constructs for midshaft fractures of the clavicle at 2 level I trauma centers to determine the rate of implant removal and identify variables associated with implant removal. We collected all patient-, injury-, and treatment-specific factors as well as information on reoperation for removal of implants. Bivariate analysis and multivariable logistic regression analysis were used to assess whether explanatory factors were associated with removal of implants after ORIF for midshaft clavicle fractures. Of the 146 patients who were treated with ORIF for midshaft clavicle fractures with plate-and-screw constructs, 41 (28%) underwent removal of the implant. The median follow-up was 836 days (interquartile range, 457-1567 days). Variables associated with increased risk of implant removal included anterior plate position (odds ratio, 5.32; 95% CI, 2.01-14.1) and number of holes in the plate (odds ratio, 1.28; 95% CI, 1.00-1.63). These results question whether anterior plating results in less implant prominence and less subsequent removal of implants. [Orthopedics. 2022;45(4):e201-e206.].

Minimum 2-year outcomes of reverse total shoulder arthroplasty for fracture: how does acute arthroplasty compare with salvage?

BACKGROUND: The objective of our study was to compare patient-reported outcome measures, range of motion (ROM), complication rates, and reoperation rates after reverse total shoulder arthroplasty (rTSA) for proximal humeral fractures between patients treated acutely (≤30 days after injury), those treated after initial nonoperative treatment (>30 days after injury), and those treated after failed open reduction-internal fixation. Secondarily, we aimed to identify any patient-, injury-, or surgery-related factors independently associated with our response variables. METHODS: We identified 576 patients who sustained a proximal humeral fracture treated with primary or revision shoulder arthroplasty between January 2003 and August 2018. The final cohort included 153 patients. Multivariable analysis was used to assess whether explanatory variables were associated with our response variables. RESULTS: Initial nonoperative treatment compared with acute rTSA was associated with worse Shoulder Subjective Value (P = .04), Shoulder Pain and Disability Index score (P = .03), and Shoulder Pain and Disability Index disability subscale score (P = .03). Only depression was independently associated with worse visual analog scale pain score (P = .04). There was no significant difference in postoperative ROM between the initial treatment groups. Older age was associated with decreased ROM in all planes. Additionally, ipsilateral upper-extremity injury was associated with decreased active abduction (P = .03), and cemented humeral stems were associated with decreased passive abduction (P = .03). Initial nonoperative treatment was associated with increased complication rates (odds ratio, 3.65; 95% confidence interval, 1.11-12.01), and male sex was associated with higher rates of reoperation (odds ratio, 3.53; 95% confidence interval, 1.31-9.51). CONCLUSIONS: Patients who undergo initial periods of nonoperative management have worse functional outcomes and higher complication rates than those who undergo acute rTSA for proximal humeral fractures. Patients who undergo rTSA after failed open reduction-internal fixation show no difference in patient-reported outcomes compared with those who undergo acute rTSA. In addition, male patients are at higher risk of reoperation, whereas older patients are at risk of decreased ROM. Patients with preoperative depression are at risk of increased pain at 2 years after surgery.

Outcome Measurement for Distal Radius Fractures.

Distal radius fractures (DRFs) are among the most common upper extremity injuries. Multiple medical conditions now are evaluated by standardized outcome sets that enable comparability. Recent international working groups have provided consensus statements for outcomes measurement after DRFs. These statements emphasized the growing importance of patient-reported outcome measures as well as traditional measures, including pain assessment, radiographic alignment, performance, and assessment of complications. A standardized instrument and timeline for measuring outcomes following DRFs offers clinicians, researchers, and health care economists a powerful tool. This article reviews the current evidence and provides recommendations for a DRF standardized outcome set.

What Factors Are Associated with Reoperation After Operative Treatment of Terrible Triad Injuries?

BACKGROUND: Terrible triad injuries of the elbow, consisting of posterior ulnohumeral joint dislocation with associated fractures of the radial head and coronoid process, are challenging injuries due to the difficulty in restoring stability to the joint surgically while also attempting to allow early ROM to prevent stiffness. Furthermore, complications are both debilitating and relatively common, frequently requiring reoperation. QUESTIONS/PURPOSES: (1) What patient-, injury-, or surgery-related factors are associated with reoperation after surgical treatment of terrible triad injuries of the elbow? (2) What are the most common causes of reoperation after these injuries? METHODS: Between January 2000 and June 2017, we identified 114 patients who had surgery for terrible triad injuries at two tertiary-care referral centers. Of those, 40% (46 of 114) were lost to follow-up before 1 year, and an additional 5% (6 of 114) were excluded because they underwent the index surgery at an outside institution (n = 4) or underwent closed reduction with or without percutaneous pinning (n = 2). That left 62 patients for analysis in this retrospective study with a minimum of 1-year follow-up (median 22 months; range 12 to 65) or who met the endpoint of reoperation before 1 year. During the study period, indications for surgical treatment of terrible triad injuries of the elbow included joint incongruity or instability precluding early ROM. In our study cohort, 45% (28 of 62) underwent reoperation. Indications for reoperation after surgical treatment included stiffness that interfered with activities of daily life, symptomatic prominent hardware, ulnar neuropathy, instability of the elbow joint at rest or with range of motion, and infection. Patient-related (such as age, sex, race), injury-related (for example, ipsilateral extremity fracture, open fracture), and surgery-related factors (for instance, time to surgery, radial head treatment) as well as outcomes were collected by the treating surgeon at the time of follow-up and ascertained using chart review. The primary outcome measure was reoperation after surgical treatment of a terrible triad injury of the elbow. Bivariate analysis was used to assess whether explanatory variables were associated with reoperation after surgical treatment of terrible triad injuries of the elbow. RESULTS: Of the patient-, injury-, and surgery-related factors that were analyzed, only radial head treatment was associated with an increased reoperation risk (p = 0.03). No other variable met criteria for inclusion in our multivariable logistic regression model (p < 0.10), and therefore, a multivariable logistic regression model was not performed. The most common indication for reoperation was stiffness (21% [13 of 62 patients]), followed by symptomatic hardware (18% [11 of 62 patients]), nerve symptoms (ulnar neuropathy 16% [10 of 62 patients] and incisional neuroma 2% [1 of 62 patients]), instability (6% [4 of 62 patients]), and wound problems (infection 2% [1 of 62 patients]). CONCLUSION: The reoperation risk after surgical treatment of terrible triad injuries of the elbow is high. No patient- or injury-related factors were associated with the reoperation risk. Based on our finding, we recommend fixation of radial head fractures in these injuries when feasible and compatible with early postoperative motion, and we suggest the use of radial head excision or arthroplasty as a secondary options. LEVEL OF EVIDENCE: Level III, therapeutic study.

Trapeziometacarpal Joint Arthritis: Is Duration of Symptoms a Predictor of Surgical Outcomes?

PURPOSE: Great effort has been placed on determining the optimal surgical treatment for trapeziometacarpal joint arthritis (TMA). However, a paucity of literature exists concerning the optimal timing of surgical intervention. We hypothesized that an increased duration of TMA symptoms before operative intervention would negatively affect surgical outcomes. METHODS: We performed a retrospective review on 109 adult patients with 121 joints with symptomatic TMA treated with trapeziectomy and ligament reconstruction with tendon interposition (LRTI) from 2006 to 2017. Outcome measures included Quick-Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score, complication rates, and surgical revision rates. RESULTS: Among 109 patients, average QuickDASH score at initial presentation was 41.1 ± 17.9. Patients had symptoms of TMA for an average of 3.2 years (median, 2.1 years) before undergoing operative intervention. Patients were divided into 2 groups: those with symptoms less than 2 years and those with symptoms greater than 2 years. Patients who underwent LRTI after less than 2 years of symptoms achieved a significantly greater degree of improvement in the QuickDASH score compared with patients with symptoms greater than 2 years (26.2 vs 5.3). CONCLUSIONS: Patients with less than 2 years of symptomatic TMA before LRTI can expect the greatest improvement in patient-reported disability impairment compared with those with more than 2 years of symptoms. This can be used to counsel patients regarding the optimal timing of surgery if nonsurgical treatment has failed to provide durable symptomatic relief. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Thumb Carpometacarpal Arthritis: Prognostic Indicators and Timing of Further Intervention Following Corticosteroid Injection.

PURPOSE: Corticosteroid injections are commonly used to treat thumb carpometacarpal arthritis in adults. We aimed to define the timing of surgery following an initial corticosteroid injection and identify patient-specific factors that influence the likelihood of repeat injection or surgery. METHODS: We performed a retrospective analysis of all patients who underwent a first-time corticosteroid injection for carpometacarpal arthritis between 2009 and 2017. Demographic information, radiographic classification, additional nonsurgical therapies, complications, and outcomes were collected. Primary outcomes were repeat injection and surgical reconstruction. Kaplan-Meier survival analysis was used to characterize the timing of surgical intervention and Cox regression modeling was used to identify predictors of subsequent intervention. RESULTS: Two-hundred thirty-nine patients (average age, 62.9 years) were identified, of which 141 (59.0%) had a repeat injection and 90 (37.6%) underwent surgery. There were no patient-specific characteristics associated with repeat injection. Eaton stage III/IV arthritis at initial presentation, current smoking status, and prior ipsilateral hand surgery were associated with an increased likelihood of surgery. By Kaplan-Meier analyses, 87.7% of patients who presented with Eaton III/IV arthritis did not have surgery within a year and 66.7% of these patients did not have surgery within 5 years. CONCLUSIONS: In this retrospective observational cohort study with 10-year follow-up from a 4-surgeon practice, advanced radiographic arthritis, current smoking status, and a history of ipsilateral hand surgery were patient-specific factors that predicted progression to surgery following injection. Of patients who presented with advanced radiographic arthritis, one-third underwent surgery within 5 years of initial injection. Although injection efficacy and causality cannot be inferred based on an observational longitudinal analysis, these data identify patient-specific factors that may have an impact on surgical decision-making and a potential timeframe for future intervention. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.

Incidence of thyroid disease in patients with forefoot deformity.

BACKGROUND: Hallux valgus and lesser toe deformities are common foot disorders with substantial functional consequences. While the exact etiologies are multi-factorial, it is unknown if certain endocrine abnormalities, such as thyroid dysfunction, may be associated with these pathologies. The current study sought to investigate the prevalence of thyroid disease in patients with hallux valgus or lesser toe deformities. METHODS: Every new patient who presented to our institution's foot and ankle clinic during a three-month time period was given a survey to determine the presence of a known thyroid disorder. The diagnosis for each visit was then recorded. Additionally, a national, publicly available database was queried for patients diagnosed with thyroid disease and concomitant hallux valgus or specific forefoot pathology. Odds ratios for the presence of thyroid dysfunction were then calculated for each patient group. RESULTS: Three-hundred and fifty initial visit patient surveys were collected, and 74 (21.1%) patients had a known diagnosis of thyroid disease. The most common diagnoses were primary hypothyroidism (n = 61, 17.4%), secondary hypothyroidism (n = 6, 1.7%), thyroiditis (n = 4, 1.1%), and hyperthyroidism (n = 3, 0.9%). Thyroid disease was present in 16 of 26 patients (61.5%) with a diagnosis of hallux valgus (OR 7.3, CI[3.16-16.99], p < 0.0001). Lesser toe deformities, including hammertoes, mallet toes, bunionettes and crossover toes, were also significantly associated with thyroid disease (OR 5.45, CI[1.83-16.26], p < 0.002). The national database revealed 905,924 patients with a diagnosis of a specific forefoot deformity, and 321,656 of these patients (35.5%) had a concomitant diagnosis of a thyroid condition (OR 2.11, CI[2.10-2.12], p < 0.0001). CONCLUSIONS: The current study suggests a significant association between forefoot pathology and thyroid dysfunction, especially hallux valgus and lesser toe deformities. Increased understanding of these correlations may offer an important opportunity in population health management, both in diagnosis and treatment. While further studies with long-term outcomes are necessary, the early diagnosis of thyroid disease may provide an opportunity to predict and potentially alter the course of forefoot pathology.

The Impact of Obesity and Smoking on Outcomes After Volar Plate Fixation of Distal Radius Fractures.

PURPOSE: Distal radius fractures are common fractures of the upper extremity. Whereas surgical outcomes have been extensively investigated, the impact of risk factors such as body mass index (BMI) and smoking on patient outcomes has not been explored. We hypothesized that obesity and smoking would have a negative impact on the functional and radiographic outcomes of surgically treated patients with distal radius fractures. METHODS: We performed a retrospective analysis of patients surgically treated for a distal radius fracture between 2006 and 2017 at 2 level 1 trauma centers. Patients were divided into obese (BMI ≥ 30) and nonobese (BMI < 30) groups according to the World Health Organization BMI Classification. Patients were also divided into current, former, and never smokers based on reported cigarette use. Primary outcomes included patient-reported outcome measures (Quick Disabilities of the Arm, Shoulder, and Hand [QuickDASH]), range of motion (ROM) arc (flexion-extension, pronation-supination), radiographic union (Radiographic Union Scoring System [RUSS] score), and change in radiographic alignment (radial height, radial inclination, volar tilt) between first and last follow-up. Multivariable models corrected for age, sex, comorbidities, fracture complexity, osteoporosis, and time to surgery. RESULTS: Two hundred patients were identified, 39 with BMI of 30 or greater and 161 with BMI less than 30. Obese patients had more comorbidities but similar fracture types. At 3-month and 1-year follow-up, both groups achieved acceptable QuickDASH scores, close to those of the general population (21 vs 18, 14 vs 2, respectively). The 2 groups were similar in regard to motion, RUSS score, and alignment. There were 148 never smokers, 32 former smokers, and 20 current smokers. At 3 months, smokers demonstrated higher QuickDASH scores (42 vs 21-24) and a lower percentage of radiographically healed fractures (40% vs 69%-82%). At final follow-up, smokers reported small differences in patient-reported outcomes (QuickDASH 18 vs 9-13) whereas ROM, fracture healing, and complication rates were similar. CONCLUSIONS: Both obese and nonobese patients can achieve excellent outcomes following surgical treatment of distal radius fracture with similar self-reported outcomes, motion, RUSS score, and alignment. Despite slower healing in the early postoperative period, smokers had similar QuickDASH scores, ROM, and union rates to past smokers and never smokers at final follow-up, with a similar complication profile. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.

Considerations in the Treatment of Osteoporotic Distal Radius Fractures in Elderly Patients.

PURPOSE OF REVIEW: With the incidence of distal radius fractures increasing in the elderly population, we sought to summarize the current orthopedic and medical management of these fractures in the elderly osteoporotic population. RECENT FINDINGS: The number of osteoporotic patients undergoing surgical fixation for distal radius fractures has increased in recent years. This is likely due to the improved outcomes seen with volar locking plates, as well as an increase in the number of fellowship-trained hand surgeons. Despite this potential improvement in acute fracture management, a majority of these patients are underdiagnosed and undertreated for their underlying osteoporosis or endocrinopathies. The implementation of fracture liaison services and the ability of the treating orthopedist to recognize this gap in patient care result in a higher number of patients initiating appropriate treatment. It is vital that when discussing acute fracture management, a thorough discussion is had with patients regarding functional outcome and the benefits of both surgical and non-operative management. As these fractures become more prevalent and a greater percentage undergo surgical intervention, the economic burden of distal radius fractures will continue to rise. It is imperative that the treating surgeon view these fractures as sentinel events that are predictive of future hip and vertebral fractures. While relatively new, the use of fracture liaison services to help aide in proper screening and treatment of osteoporotic patients is of great value. Non-pharmacologic therapy such as physical therapy, smoking and alcohol cessation programs, and dietary modifications are crucial in treating patients with osteoporosis. While bisphosphonates remain the first-line treatment in patients with osteoporosis, novel therapies show promise for future use.

Early prognostic factors of outcomes in monochorionic twin pregnancy: systematic review and meta-analysis.

BACKGROUND: Monochorionic twin pregnancies are high-risk, however at present, no screening test is available to predict which monochorionic twin pregnancy will develop complications. OBJECTIVE: We sought to assess ability of first-trimester pregnancy-related factors (ultrasound measurements, maternal characteristics, biomarkers) to predict complications in monochorionic twin pregnancies. DATA SOURCES: Data sources were MEDLINE, Embase, ISI Web of Science, CINAHL, the Cochrane Central Registration of Controlled Trials and Research Registers, and Google Scholar, from inception to May 12, 2017. Gray literature and bibliographies of articles were checked. STUDY ELIGIBILITY CRITERIA: Studies that reported ultrasound measurements, maternal characteristics, or potential biomarkers, measured in the first trimester in monochorionic-diamniotic twin pregnancies, where the potential prognostic ability between the variable and twin-twin transfusion syndrome, growth restriction, or intrauterine fetal death could be assessed, were included. STUDY APPRAISAL AND SYNTHESIS METHODS: Quality assessment was evaluated using the Strengthening the Reporting of Observational Studies in Epidemiology checklist by 2 reviewers independently. For meta-analysis, odds ratios using a random effects model, or standardized mean difference were calculated. If a moderate association was found, the prognostic ability was evaluated by calculating the sensitivity and specificity. Risk of heterogeneity was reported as I2 and publication bias was visually assessed by funnel plots and quantitatively by Egger test. RESULTS: In all, 48 studies were eligible for inclusion. Twenty meta-analyses could be performed. A moderate association was demonstrated in 3 meta-analyses, between: nuchal translucency >95th centile in one/both fetuses and twin-twin transfusion syndrome (odds ratio, 2.29 [95% confidence interval, 1.05-4.96], I2 = 6.6%, 4 studies, 615 pregnancies); crown-rump length discordance ≥10% and twin-twin transfusion syndrome (odds ratio, 2.43 [95% confidence interval, 1.13-5.21], I2 = 14.1%, 3 studies, 708 pregnancies); and maternal ethnicity and twin-twin transfusion syndrome (odds ratio, 2.12 [95% confidence interval, 1.17-3.83], I2 = 0.0%, 5 studies, 467 pregnancies), but none demonstrated a prognostic ability for any outcome under investigation. CONCLUSION: It is not currently possible to predict adverse outcomes in monochorionic twin pregnancies. We have revealed a lack of research investigating first-trimester biomarkers in monochorionic twin pregnancies. Different assessment methods and definitions of each variable and outcome were an issue and this highlights the need for a large cohort study to evaluate these factors.

Achievement Of Primary Stability Using 3D-CT Guided Custom Design Femoral Stems In Patients With Proximal Femoral Deformity : EBRA-FCA Analysis.

Hip replacement in patients with proximal femoral deformity and end stage arthrosis is technically challenging. The purpose of this study was to measure the subsidence rate of custom femoral stems using EBRA-Femoral Component Analysis (FCA) software, as an indicator of achievement of primary stability. We retrospectively reviewed 14 hips in 12 consecutive patients who underwent this procedure between June 2008 and Feb. 2011. There were 7 males and 5 females with a mean age 41 years (22-60). The primary diagnosis in the majority of the cases was Perthes and DDH with secondary osteoarthritis. The average follow up period was 36 ± 10 months (19-51 months). Average subsidence was the 0.96 mm ± 0.95mm (0- 2.9 mm). All patients had signs of osteointegration at the metaphyseal level. We conclude that the 3D-CT guided custom made femoral stem produces reliable proximal 'fit and fill' and osteointegration without the need of a corrective osteotomy in patients with proximal femoral deformity but long term studies are needed to assess the performance of this femoral stem.

Tibial tubercle osteotomy for patello-femoral joint disorders.

Tibial tubercle osteotomy has a long history in the management of patella instability and patello-femoral arthritis. This review aims to provide a comprehensive review of the literature describing the biomechanics of the patello-femoral joint and the rationale behind the use of the tibial tubercle osteotomy in modern day practice. Several different tibial tubercle osteotomies are available and we aim to detail the concepts behind their use and the subsequent clinical results. With continued developments of chondrocyte implantation techniques, the potential to fill defects on the chondral surface of either the patella or trochlea in conjunction with a tibial tubercle osteotomy may well become more commonplace in a group that is commonly young and difficult to manage. Level of evidence III.

Medium to long-term results of the UNIX uncemented unicompartmental knee replacement.

INTRODUCTION: We report the first non-designer study of the Unix uncemented unicompartmental knee prosthesis. MATERIALS AND METHODS: Eighty-five consecutive UKRs were carried out with sixty-five available for follow-up. Oxford Knee Scores, WOMAC questionnaire and radiological assessment were completed. RESULTS: The mean Oxford Knee Score was thirty-eight and WOMAC Score was twenty. Overall Kaplan Meier survival estimate is 76% (95% confidence interval 60%-97%) at 12years and 88% (95% confidence interval 76-100%) with aseptic loosening as the endpoint. Radiographic assessment showed lysis in the tibia in 6% of patients with no lysis evident around the central fin. DISCUSSION: Survivorship is comparable to other published series of UKRs. We suggest the central fin design is key to dissipating large forces throughout the proximal tibia, resulting in low levels of tibial loosening. Level of evidence IV.

Deformed wing virus implicated in overwintering honeybee colony losses.

The worldwide decline in honeybee colonies during the past 50 years has often been linked to the spread of the parasitic mite Varroa destructor and its interaction with certain honeybee viruses. Recently in the United States, dramatic honeybee losses (colony collapse disorder) have been reported; however, there remains no clear explanation for these colony losses, with parasitic mites, viruses, bacteria, and fungal diseases all being proposed as possible candidates. Common characteristics that most failing colonies share is a lack of overt disease symptoms and the disappearance of workers from what appears to be normally functioning colonies. In this study, we used quantitative PCR to monitor the presence of three honeybee viruses, deformed wing virus (DWV), acute bee paralysis virus (ABPV), and black queen cell virus (BQCV), during a 1-year period in 15 asymptomatic, varroa mite-positive honeybee colonies in Southern England, and 3 asymptomatic colonies confirmed to be varroa mite free. All colonies with varroa mites underwent control treatments to ensure that mite populations remained low throughout the study. Despite this, multiple virus infections were detected, yet a significant correlation was observed only between DWV viral load and overwintering colony losses. The long-held view has been that DWV is relatively harmless to the overall health status of honeybee colonies unless it is in association with severe varroa mite infestations. Our findings suggest that DWV can potentially act independently of varroa mites to bring about colony losses. Therefore, DWV may be a major factor in overwintering colony losses.

Novel virus dynamics in an Emiliania huxleyi bloom.

Diel studies of an Emiliania huxleyi bloom within a mesocosm revealed a highly dynamic associated viral community, changing on small times scales of hours.

Detection of virus mRNA within infected host cells using an isothermal nucleic acid amplification assay: marine cyanophage gene expression within Synechococcus sp.

BACKGROUND: Signal-Mediated Amplification of RNA Technology (SMART) is an isothermal nucleic acid amplification technology, developed for the detection of specific target sequences, either RNA (for expression) or DNA. Cyanophages are viruses that infect cyanobacteria. Marine cyanophages are ubiquitous in the surface layers of the ocean where they infect members of the globally important genus Synechococcus. RESULTS: Here we report that the SMART assay allowed us to differentiate between infected and non-infected host cultures. Expression of the cyanophage strain S-PM2 portal vertex gene (g20) was detected from infected host Synechococcus sp. WH7803 cells. Using the SMART assay, we demonstrated that g20 mRNA peaked 240-360 minutes post-infection, allowing us to characterise this as a mid to late transcript. g20 DNA was also detected, peaking 10 hours post-infection, coinciding with the onset of host lysis. CONCLUSION: The SMART assay is based on isothermal nucleic acid amplification, allowing the detection of specific sequences of DNA or RNA. It was shown to be suitable for differentiating between virus-infected and non-infected host cultures and for the detection of virus gene expression: the first reported use of this technology for such applications.

The simulation of condensation removal of a heavy metal from exhaust gases onto sorbent particles.

A numerical model BAEROSOL for solving the general dynamic equation (GDE) of aerosols is presented. The goal was to model the capture of volatilized metals by sorbents under incinerator-like conditions. The model is based on algorithms presented by Jacobson and Turco [Aerosol Science and Technology 22 (1995) 73]. A hybrid size bin was used to model growth and formation of particles from the continuum phase and the coagulation of existing particles. Condensation and evaporation growth were calculated in a moving size bin approach, where coagulation and nucleation was modeled in the fixed size bin model of the hybrid grid. To account for the thermodynamic equilibrium in the gas phase, a thermodynamic equilibrium code CET89 was implemented. The particle size distribution (PSD) calculated with the model was then compared to analytical solutions provided for growth, coagulation and both combined. Finally, experimental findings by Rodriguez and Hall [Waste Management 21 (2001) 589-607] were compared to the PSD predicted by the developed model and the applicability of the model under incineration conditions is discussed.