Preoperative severe vitamin D deficiency is a significant independent risk factor for poorer functional outcome and quality of life 6 months after surgery for fragility hip fractures.

Hip fractures are common in the elderly, and many patients with hip fractures have low vitamin D levels. This study found that severe vitamin D deficiency is linked to poorer recovery of function and quality of life after hip fracture surgery. INTRODUCTION: Vitamin D deficiency is prevalent in hip fracture patients and associated with increased mortality and complications. However, there is limited long-term data on how vitamin D levels affect functional outcomes after hip fracture surgery. The aim of this study is to ascertain the association between vitamin D levels and recovery from hip surgery. METHODS: Patients who underwent hip fracture surgery from January 2012 to December 2016 and had vitamin D levels assessed during admission were included. Retrospective analysis was performed on patients' demographic data such as age, gender and clinical parameters such as preoperative vitamin D, haemoglobin levels, Charlson Comorbidity Index (CCI), and type and site of surgery. Patients were divided according to four different vitamin D levels-severe vitamin D deficiency (≤10 ng/mL), mild deficiency (10-20 ng/ml), insufficiency (20-30 ng/ml), and normal (>30ng/ml). Functional outcomes were measured by Harris Hip Score (HHS), Parker Mobility Score (PMS), and individual domains of 36-Item Short Form Health Survey (SF36). Univariate and multivariate analyses were conducted to examine the association between vitamin D deficiency and functional outcome scores. RESULTS: Out of 664 patients identified, 9% had severe vitamin D deficiency and 39% mild deficiency. Patients with severe vitamin D deficiency had significantly poorer baseline and 6-month PMS and SF36 Physical Functioning (PF). In multivariate analysis, severe vitamin D deficiency was associated with lower 6-month PMS and SF36 PF. CONCLUSION: Preoperative severe vitamin D deficiency is an independent risk factor for poorer recovery of function and quality of life after hip fracture surgery.

Excess mortality after hip fracture: fracture or pre-fall comorbidity?

Comorbidity and hip fracture independently increased mortality risk for 9 years in both sexes, with a significant additive interaction in the first year among women and through 6 years among men. INTRODUCTION: Hip fracture is associated with a persistently elevated mortality risk, but it is unknown whether the elevated risk is due to the fracture or to pre-fracture comorbidity. METHODS: In a population-based study in Singapore with 9 years of follow-up, patients age > 50 with first hip fracture from 2008 to 2017 were pair-matched to a cohort without hip fracture by age, sex, ethnicity, and pre-fracture Charlson Comorbidity Index (CCI). We investigated additive interaction using the relative excess risk due to interaction (RERI) and multiplicative interaction using the ratio of relative risks. RESULTS: Twenty-two thousand five hundred ninety of 22,826 patients with a first hip fracture in 2008-2017 were successfully matched. Hip fracture and comorbidity independently increased mortality risk for 9 years in both sexes. After adjustment for comorbidity, excess mortality risk continued to persist for 9 years post-fracture in both men and women. Women with a hip fracture and pre-fracture CCI > 4 had a higher relative risk (RR) of mortality at 9 years of 3.29 [95% confidence interval (CI) 3.01, 3.59] than those without comorbidity (RR 1.51, 95%CI 1.36, 1.68) compared to the referent without hip fracture or comorbidity. An additive interaction between hip fracture and pre-fracture CCI > 4 was observed in the first post-fracture year` [relative excess risk due to interaction (RERI) 1.99, 95%CI 0.97, 3.01]. For men with CCI ≥ 4, the positive additive interaction was observed through 6 years. CONCLUSIONS: Excess mortality risks post-fracture are attributable to both the fracture and pre-fracture comorbidity. Early interventions in hip fracture patients with high comorbidity could reduce their excess mortality.

Cephalomedullary blade cut-ins: a poorly understood phenomenon.

OBJECTIVES: Proximal femoral nail antirotation (PFNA) cut-in is a unique phenomenon seen in pertrochanteric hip fractures treated with the PFNA. Cut-in refers to the superomedial migration of the proximal femoral blade into the femoral head and hip joint. We recognize that cut-in is a completely separate entity from the well-described cut-out failure. This study assesses relevant radiological and patient risks factors for cut-in. DESIGN: Retrospective multicenter study looking at patients with pertrochanteric hip fractures managed with the Synthes PFNA SETTING: Four tertiary hospitals over 7 years. PATIENTS: Patients with cut-ins were identified. OUTCOME MEASUREMENT: The radiological appearance of this mode of failure was assessed and compared to cut-outs. Patient demographics, fracture configuration, time to implant failure (cut-in), bone mineral density, tip-apex distance, neck-shaft angle and position of the tip of the helical blade in the femoral head were collected. RESULTS: There was a total of 1027 patients across 4 institutions with 23 patients with cut-in. Average neck-shaft angle was 133 degrees. 16 out of 19 patients had severe osteoporosis with BMD < - 2.5. 14 of 23 patients had poor placement of the blade. 13 of 23 had a tip-apex distance of more than 20 mm. CONCLUSION: We propose a standardized nomenclature of "cut-in" for the phenomenon of superomedial migration of the proximal femoral blade. An anatomical neck-shaft reduction, accurate blade placement and increased surveillance for patients with severe osteoporosis are required to reduce the incidence and morbidity of cut-in.

Natural history of incomplete atypical femoral fractures in patients after a prolonged and variable course of bisphosphonate therapy-a long-term radiological follow-up.

Understanding the natural history of lateral femoral stress fractures helps to guide their management. Improvement in their radiographic characteristics is rare. Progression was generally sequential, most developing an incomplete fracture line before fracture displacement. Stopping bisphosphonates decreased the fracture rate, a feasible management option for lesions without incomplete fracture lines. INTRODUCTION: Retrospective study evaluating the natural history of lateral femoral stress fractures (FSF) by serial radiography over a variable period of time in a cohort of patients treated for some time with bisphosphonates for osteoporosis, whilst also identifying the fracture response in cases where bisphosphonates were discontinued. METHODS: The radiographs of 76 consecutive patients (92 femurs) with 161 FSF were reviewed to document their change over time. Femurs were classified into the following: A-normal, B-focal cortical thickening, C-dreaded black line and D-displaced fracture. Bisphosphonate history was recorded. RESULTS: 66.5% FSF showed group stability between the first and last radiographs: group B (79.1%), group C (45.7%). 28.6% progressed, mostly following an ordered sequence starting from group A, progressing to B, then C, before culminating in D. Progression rate was as follows: A-100% (11/11), B-18.3% (21/115), C-40% (14/35). Regression in FSF was uncommon-5.6% (8/161). 34.8% (32/92) sustained displaced fractures. Kaplan-Meier analysis showed statistically significant difference between the groups; median survival (95% CI): A-4189 (-), B-3383.0 (-), C-1807 (0.0-3788.6) and progression to displaced fracture when bisphosphonate had been stopped for at least 6 months. The group without recent bisphosphonates had a lower group progression rate (17.1%, 12/70). Nevertheless, 10.9% (5/46) progressed to displaced fracture. This group also had the highest proportion of stable (77.1%, 54/70) and regressive lesions (5.7%, 4/70). CONCLUSIONS: In FSF, there is natural progression from normal bone, to focal cortical thickening, to dreaded black line and eventually to displaced fracture. Most lesions persist, remaining static or progressing, especially if a dreaded black line is present and bisphosphonates are continued. Regression is uncommon and more frequent when bisphosphonates are discontinued. Despite stopping bisphosphonates, there remains a 10.9% risk of progression to displaced fracture.

Pre-discharge prognostic factors of physical function among older adults with hip fracture surgery: a systematic review.

INTRODUCTION: To identify, organize, and assess the evidence level of pre-discharge prognostic factors of physical function beyond discharge after hip fracture surgery. METHODS: We performed a systematic search of four databases (PubMed, Embase, CINAHL, PsycINFO) for longitudinal studies of prognostic factors of physical function at ≥ 1 month among older adults ≥ 50 years old with surgically treated hip fracture, complemented with hand-searching. Two reviewers independently screened papers for inclusion and assessed the quality of all the included papers using the Quality in Prognosis Studies (QUIPS) tool. We assigned the evidence level for each prognostic factor based on consistency in findings and study quality. RESULTS: From 98 papers that met our inclusion criteria, we identified 107 pre-discharge prognostic factors and organized them into the following seven categories: demographic, physical, cognitive, psychosocial, socioeconomic, injury-related, and process of care. Potentially modifiable factors with strong or moderate evidence of an association included total length of stay, physical function at discharge, and grip strength. Factors with strong or moderate evidence of no association included gender, fracture type, and time to surgery. Factors with limited, conflicting, or inconclusive evidence included body-mass index, psychological resilience, depression, and anxiety. CONCLUSIONS: Our findings highlight potentially modifiable prognostic factors that could be targeted and non-modifiable prognostic factors that could be used to identify patients who may benefit from more intensive intervention or to advise patients on their expectations on recovery. Examining the efficacies of existing interventions targeting these prognostic factors would inform future studies and whether any of such interventions could be incorporated into clinical practice.

Administration of tranexamic acid for victims of severe trauma within pre-hospital care ambulance services (PHCAS) in Malaysia.

INTRODUCTION: Trauma is a Global threat and the 5th highest cause of all-cause mortality in Malaysia caused predominantly due to road traffic accidents. Majority of trauma victims are young adults aged between 21-40 years old. In Malaysia, 24 out of 100,000 population die annually due to trauma, rating us amongst the highest in South East Asia. These alarming figures justify aggressive preventive and mitigation strategies. The aim of this paper is to promote the implementation of evidence-based interventions that will reduce the rate of preventable death because of trauma. Tranexamic acid is one of the few interventions in the early management of severe trauma with level-one evidence. Tranexamic acid has been proven to reduce all causes of mortality and mortality due to bleeding. Evidence proves that it is most effective when administered early, particularly within the 1st hour of trauma. This proposed guideline is formulated based upon quality evidence from multicentre studies, clinical practices in other countries and consideration of the local demographic factors with the intent of enabling an easy and simple pathway to administer tranexamic acid early in the care of the severely injured. CONCLUSION: The guideline highlights select pre-hospital criteria's and the methods for drug administration. The authors recognise that some variants may be present amongst certain institutions necessitating minor adaptations, nevertheless the core principles of advocating tranexamic acid early in the course of pre-hospital trauma should be adhered to.

A multidimensional assessment of the burden of psoriasis: results from a multinational dermatologist and patient survey.

BACKGROUND: Psoriasis is a chronic, immune-mediated disease, characterized by symptoms that include itching and skin pain and is often associated with comorbidities. Patients have a substantial detriment to quality of life (QoL) and work productivity with associated cost burden. OBJECTIVES: To investigate the incremental burden of comorbidities, itch and affected body areas among systemic eligible patients with psoriasis, using a multinational survey of dermatologists and their patients with psoriasis. METHODS: Multinational data from the Growth from Knowledge (GfK) Disease Atlas Global Real-World Evidence program were used. Eligible patients were identified as those who were currently having or had ever had moderate-to-severe psoriasis, and must have been receiving prescription treatments at the time of the survey. Multivariable regression analyses were conducted to assess the incremental burden among psoriasis patients with physical and psychological comorbidities, itch and affected visible and sensitive body areas vs. psoriasis patients without these conditions, respectively. RESULTS: The study enrolled 3821 patients with psoriasis, from nine countries, with an average Psoriasis Area and Severity Index score of 6·4. The presence of comorbidities was associated with a significant increase in the likelihood of skin pain, lower QoL, greater work impairment and increased usage of medical resources (except in psoriasis patients with obesity and type 2 diabetes). Psoriasis patients suffering from itch and those with visible and sensitive affected body areas also had impaired QoL vs. those without these conditions. CONCLUSIONS: Psoriasis patients with physical and psychological comorbidities, itch and affected visible and sensitive body areas had lower QoL and greater work impairment compared to those without these conditions.

Patient-dermatologist agreement in psoriasis severity, symptoms and satisfaction: results from a real-world multinational survey.

BACKGROUND: Psoriasis is a chronic immune-mediated inflammatory disease, which often requires lifelong treatment. A strong partnership between the patient and healthcare practitioners should help to achieve effective treatment outcomes. OBJECTIVE: To assess concordance of views between patients with psoriasis and their treating dermatologists relative to psoriasis severity, presence of symptoms and satisfaction with disease control achieved. METHODS: We used data from the Growth from Knowledge (GfK) Disease Atlas real-world evidence program, a syndicated, retrospective, cross-sectional survey among dermatologists and their systemic therapy eligible patients with psoriasis, conducted across nine countries. Concordance was measured through patients and their dermatologist's identical answers to the same survey questions. Concordance was evaluated using percentage agreement between dermatologists and their patients, and Cohen's kappa (κ) statistic. The level of concordance was defined as 'none' (κ ≤ 0), 'none to slight' (0.01-0.20), 'fair' (0.21-0.40), 'moderate' (0.41-0.60), 'substantial' (0.61-0.80) and 'almost perfect' (>0.8). The analysis was conducted for the overall population and for each participating country. RESULTS: Overall, 524 dermatologists and 3821 patients with psoriasis were included in the survey. Concordance of patient and dermatologist perceptions of psoriasis severity was fair both at diagnosis, and at the time of the survey (61% agreement, κ = 0.326 and 55% agreement, κ = 0.370, respectively). Higher levels of concordance were reported when patients assessed their psoriasis as moderate-to-severe (using Investigator's Global Assessment/Physician's Global Assessment [IGA/PGA] 5-point scale of 3 or 4). Concordance regarding symptoms ranged from fair to moderate (κ = 0.241-0.575). Satisfaction with psoriasis control was fair (39% agreement, κ = 0.213). Results showed different patterns of concordance across the participating countries although a low concordance was observed on the satisfaction with psoriasis control in all of them. CONCLUSION: Results from this multinational real-world survey indicate different perceptions between patients with psoriasis and their dermatologist with respect to psoriasis severity, symptoms and disease control.

Bilateral ulna fractures associated with bisphosphonate therapy.

We report a case of bilateral ulna stress fractures following bilateral femoral fractures associated with long-term bisphosphonate use. The patient is an 84-year-old woman receiving 15 years of bisphosphonate therapy. She did not have any preexisting medical conditions which are known secondary causes of bone loss. She was mostly housebound and used a walking frame for ambulation. She presented with atraumatic right ulna pain and subsequent atraumatic left ulna pain a month later. She was treated conservatively in backslabs and her bisphosphonate was stopped. Investigations did not reveal any secondary causes of osteoporosis or metabolic bone disorders.

A case of an atypical femoral fracture associated with bacterial biofilm--pathogen or bystander?

We report a case of an 86-year-old woman with an atypical femoral fracture (AFF) who was treated with intramedullary nailing followed by lateral femoral plating. She developed a second femoral shaft fracture distal to the intramedullary nail which required a second operation. Biopsy of the periosteum overlying the site of the initial proximal AFF was sent for pathogen analysis. Using the Ibis T5000 platform and the BAC plate assay, a polymicrobial infection was diagnosed consisting of Bifidobacterium subtile and Pseudomonas mendocina. This raises the possibility that bacterial infections may play some role in atypical fractures of the femur.

SF-36 physical function and general health domains are independent predictors of acute hospital length of stay after hip fracture surgery.

OBJECTIVE: The demographics and co-morbidities of individuals may impact healthcare consumption, but it is less understood how premorbid physical and mental function may influence these effects. The aim of this study is to determine patient's pre-fracture quality of life and mobility affect acute hospital burden in the management of hip fracture, using length of stay (LOS) as a proxy for healthcare resource. MATERIALS AND METHODS: This is a retrospective study which investigated hip fracture patients who underwent surgery over the period of 2017-2020. Variables collected include LOS, age, gender, race, marital status, payer type, ASA score, time to surgery (TTS), type of surgery, fracture type, POD1 mobilization, discharge disposition, pre-fracture SF-36, EQ-5D and Parker mobility score (PMS) based on patient's recollection on admission. These variables were correlated with LOS using binary logistic regression on SAS. RESULTS: There were 1045 patients, and mean age was 79.5 + 8.57 (range 60-105) years with an average LOS 13.64 + 10.0 days (range 2-114). On univariate analysis, PMS, EQ-5D and all domains of SF-36 except bodily pain (BP), emotional role and mental health were associated significantly with LOS. Amongst the QOL and PMS scores, only the domains of SF-36 Physical Function (PF) (OR = 0.993, p = 0.0068) and General Health perception (GH) (OR 0.992, p = 0.0230) remained significant on the multivariate model. CONCLUSION: Our study showed that poor premorbid scores of SF36 PF and GH are independent factors associated with longer LOS in hip fracture patients after surgery, regardless of fracture type, age and ASA status. Hence, premorbid SF36 PF and GH can be used to identify patients that are at risk of prolonged hospital stay and employ targeted strategies to facilitate rehabilitation and discharge planning.

Concomitant Ulnar Styloid Fractures in Distal Radius Osteosynthesis Does Not Impact Radiographic Outcomes, Ulnar Sided Symptoms and Patient Outcomes.

Introduction: Current literature reports varied significance of ulnar styloid fractures (USF) associated with distal radius fractures. Our study assesses the role of ulnar styloid fractures and fragment size in surgically managed distal radius fractures. Materials and methods: We reviewed patients who underwent surgical fixation of distal radius fractures between January 2004 to June 2006. Patients were divided into those with (Group 1) and without (Group 0) USFs. Post-operative radiographic parameters, clinical outcomes and overall wrist function were analysed. Outcomes included ulnar-sided wrist pain, extensor carpi ulnaris (ECU) tendinitis, triangular fibrocartilage complex (TFCC) grind test, distal radioulnar joint (DRUJ) instability and pain. Overall wrist function was assessed with range of motion and Disabilities of the Arm, Shoulder and Hand (DASH) score. Results: Our study cohort included 31 males and 23 females, and 38.9% of these patients had concomitant USFs. There was no difference in terms of demographic data and fracture configuration between groups. Radiographic parameters were similar, except for palmar tilt, which was significantly higher in Group 1 (4.6º vs 9.4º, p=0.047). At 24 months, there were no differences in clinical outcomes and overall wrist function. A sub-group analysis showed that mean USF fragment size was larger in patients with a positive TFCC grind test (3.9mm vs 7.3mm, p=0.033). Conclusion: The presence of USFs in surgically managed distal radius fractures does not compromise clinical and functional outcome. Similarly, the size of USFs does not impact clinical and functional outcome but is associated with the presence of a positive TFCC grind test.

Shorter acute hospital length of stay in hip fracture patients after surgery predicted by early surgery and mobilization.

Time to surgery, early mobilization, fracture type, and ASA grades independently affect acute hospital length of stay after hip fracture surgery. Modifiable factors can be audited to reduce length of stay, and non-modifiable factors can be used for consideration of a tiered bundled payment reimbursement model. INTRODUCTION: As hip fracture incidence rises with our ageing global population, there will be an increase in consumption of healthcare resources. We hypothesized that hospital management and patient factors can affect healthcare burden load. Using length of stay (LOS) as a surrogate for consumption, the aim of this study is to elucidate the effect of hospital management and patient-related factors on length of stay (LOS) for patients after hip fracture surgery. We studied modifiable and non-modifiable factors influencing LOS, and identification of these modifiable factors accords opportunities for mitigating these factors. METHODS: This retrospective study examines hip fracture data from a large tertiary hospital in Singapore over the period of 2017 to 2020. Data collected on the electronic medical record included age, gender, race, marital status, payer type, ASA score, TTS, type of surgery, fracture type, POD1 mobilization, discharge position, and presence of pressure sores, and they were correlated with LOS using binary logistic regression on SAS. RESULTS: A total of 1045 patients were included in this study with 704 females and 341 males. The mean age was 79.5 ± 8.57 years (range 60-105) with an average LOS 13.64 ± 10.0 days (range 2-114). On binary logistic regression, ASA and trochanteric fracture remains a significant non-modifiable factor for LOS with OR = 1.486 (95% CI 1.106, 1.996, p = 0.0086) and OR 1.522 (95% CI 1.149, 2.015, p = 0.0034) respectively. Significant modifiable factors were TTS > 48 h (OR = 1.819, 95% CI 1.205, 2.746, p = 0.0044) and POD1 mobilization (OR = 0.441, 95% CI 0.257, 0.756, p = 0.0029). CONCLUSIONS: Our analysis showed TTS and POD1 are significant modifiable factors for LOS, and resources can be diverted towards them for the management of hip fracture patients and pre-empting the increasing load on our healthcare system.

Appropriate attitude promotes mask wearing in spite of a significant experience of varying discomfort.

BACKGROUND: Despite increasing evidence to support mask effectiveness in mitigating the spread of COVID-19, there is still raging controversy regarding the use of masks. Evaluation of public perceptions, attitudes and the individuals' experience towards mask-wearing is integral to ensuring reasonable compliance and allows authorities to address concerns held by the population. METHODS: A cross-sectional survey of lay-people was conducted within a high volume tertiary level institution in Singapore, from 16 October to 16 November 2020. Surveys administered evaluated five questions: 1) duration of mask wear per day, 2) mask-type used, 3) perceived necessity, 4) discomfort level experienced and 5) causes for discomfort. RESULTS: Out of 402 respondents, 67.2% primarily wore disposable surgical masks. 72% felt mask-wearing was necessary to control COVID-19 transmission. 78.4% reported discomfort while wearing masks, with mean discomfort levels of 4.21 out of 10. Impairment to breathing and communication difficulties were the most common discomforts faced. Younger respondents complained of higher incidence of dermatological issues and sweating (p < 0.05). Respondents who wore masks for longer duration reported higher incidence of dermatological issues (p = 0.001) and sweating (p = 0.032). CONCLUSION AND RELEVANCE: Even with an available vaccine, adjunctive public health measures such as mask-wearing will likely continue in order to curb COVID-19 transmission. Experience from past pandemics is likely to propagate self-protective behavior within a community. Our study identified several common mask-wearing discomforts, allowing respective organizations valuable market feedback for research and development. With appropriate public attitudes, effective mask-wearing compliance can be attained in a concerted effort against the coronavirus.

Lower-limb risk factors for falls in people with diabetes mellitus.

BACKGROUND: Older people with diabetes mellitus (DM) may be at high risk of falling because of general risk factors for falls as well as disease-specific factors. AIMS: To determine the prevalence of falls and to investigate lower-limb factors for falls in older people with DM. Methods Sixty patients with DM over 55 years of age were recruited. 'Fallers' were those who self-reported at least one fall in the previous year. In addition to diabetes status and demographic information, the following were assessed: neuropathy symptom score (NSS), neuropathy disability score (NDS), foot deformity score (FDS), Tinetti performance-oriented assessment of mobility (POMA), ankle muscle strength and gait parameters. Data from 'fallers' and 'non-fallers' were compared and logistic regression analysis performed to identify variables predictive of falls. RESULTS: Thirty-five per cent (n = 21) of participants had fallen in the preceding year. Compared with 'non-fallers', there was a greater incidence of peripheral neuropathy among 'fallers' (86% of 'fallers' and 56% of 'non-fallers'), higher vibration perception threshold (P = 0.04), slower gait velocity (P < 0.001), lower muscle strength for dorsiflexion, plantarflexion, inversion and eversion (all P < 0.001) and higher incidence of bony prominences and prominent metatarsal heads (both P < 0.001). There was a strong and significant correlation between dorsiflexion muscle strength and gait velocity. Logistic regression analysis determined that walking velocity, strength of ankle dorsiflexors and NSS accurately predicted 75% of 'fallers'. CONCLUSIONS: Simple clinical measures of gait velocity and ankle muscle strength may be used to identify people with DM at risk of falling, allowing preventative strategies to be implemented.

'Like a sieve': an exploratory study on cognitive impairments in patients with multiple myeloma.

The aim of this study was to obtain a more in-depth understanding of cognitive impairments and concerns as described by patients with multiple myeloma and the strategies used to cope with them. Semi-structured qualitative interviews were undertaken with 15 multiple myeloma patients of differing age ranges and at various stages of their disease. Various cognitive impairments, such as problems with short-term memory, poor recall and lack of concentration were observed and/or expressed in at least 10 out of 15 patients, all of them long(er)-term survivors. In some patients cognitive impairments significantly interfered with their personal and professional lives, and for some patients these were described as permanent. The patients used various coping strategies, from denial, taking notes, writing diaries, reading simpler texts, using talking books and videos, to using systems for counting medication to cope with the results of their cognitive impairment. Our findings differ from much of the contemporary literature which states that if cognitive impairments in cancer patients occur, they are mostly mild and transient. More proactive supportive care is needed to help patients with multiple myeloma to cope with poorer cognitive functioning.

Scanning Electron Microscopy Study of Retrieved Implants Suggests a Ratcheting Mechanism Behind Medial Migration in Cephalomedullary Nailing of Hip Fractures.

INTRODUCTION: Medial migration is the paradoxical migration of the femoral neck element (FNE) superomedially against gravity with respect to the intramedullary component of the cephalomedullary device, increasingly seen in the management of pertrochanteric hip fractures with the intramedullary nail. We postulate that the peculiar anti-gravity movement of the FNE in the medial migration phenomenon stems from a ratcheting mechanism at the intramedullary nail-FNE interface, which should inadvertently produce unique wear patterns on the FNE that can be seen with high-powered microscopy. By examining the wear patterns on retrieved implants from patients with medial migration, our study aims to draw clinical correlations to the ratcheting mechanism hypothesis. MATERIAL AND METHODS: Four FNEs were retrieved from revision surgeries of four patients with prior intramedullary nail fixation of their pertrochanteric hip fractures complicated by femoral head perforation. The FNEs were divided into two groups based on whether or not there was radiographic evidence of medial migration prior to the revisions. Wear patterns on the FNEs were then assessed using both scanning electron microscopy and light microscopy. RESULTS: Repetitive, linearly-arranged, regularly-spaced, unique transverse scratch marks were found only in the group with medial migration, corresponding to the specific segment of the FNE that passed through the intramedullary component of the PFNA during medial migration. These scratch marks were absent in the group without medial migration. CONCLUSION: Our findings are in support of a ratcheting mechanism behind the medial migration phenomenon with repetitive toggling at the intramedullary nail-FNE interface and progressive propagation of the FNE against gravity.

Effect of leg dominance on early functional outcomes and return to sports after anterior cruciate ligament reconstruction.

INTRODUCTION: The effect of leg dominance on anterior cruciate ligament (ACL) injuries has been studied with some studies noting a propensity for injuries in the non-dominant leg. Its effect on post-ACL reconstruction recovery, however, is not well known. The authors hypothesize that dominant limb injuries undergo rehabilitation faster and positively affect early functional outcome scores and return to sports and set about studying these effects. METHODS: This is a retrospective study of 254 patients from a single institution who underwent ACL reconstruction for acute ACL ruptures and the results were compared between patients with dominant and non-dominant limb injuries. Objective measurements including the KT-1000, single-leg hop distance and Biodex knee extension peak torque were used to evaluate recovery. Pre- and post-operative functional outcome scores such as the International Knee Documentation Committee (IKDC), Tegner activity score and Lysholm knee scale were documented. RESULTS: Early functional outcomes were similar. Minimal clinically important difference (MCID) improvement in IKDC scores was achieved in 69.7% of the dominant versus 66.0% of the non-dominant injury group (p = 0.99), 75.2% versus 79.6% (p = 0.45) for the Lysholm knee scale, and 81.6% versus 84.9% (p = 0.50) for the Tegner activity score. The majority of patients in both subgroups had a return of at least 80% of peak knee flexion and extension peak torque at 5.4 months post-operatively; 92.9% of subjects with a non-dominant leg injury and 87.2% with a dominant leg injury had returned to their pre-injury sports 1 year from surgery. CONCLUSIONS: Results from this study suggest that despite theoretical differences, leg dominance does not have a significant impact on short-term functional outcomes and return to sports. Objective measurements suggest that limb strength recovers at a comparable rate. Injuries to either leg demonstrate equally positive improvement post-ACL reconstruction given the same post-operative rehabilitation. LEVEL OF EVIDENCE: III, retrospective comparative study. LEVEL OF EVIDENCE: III, retrospective cohort study.

A single recombinant plasmid expressing two major outer surface proteins of the Lyme disease spirochete.

A gene bank of DNA from the Lyme disease spirochete was constructed in the plasmid pBR322. Plasmid pTRH32, a recombinant that in Escherichia coli expresses the two major outer surface proteins of the Lyme disease spirochete, was identified. One of the recombinant products, designated OspA, represents a surface protein that appears to be common to all Lyme disease spirochetes, whereas the other recombinant product, designated OspB, represents a more variable surface protein. This recombinant plasmid provides a foundation for future studies on the epidemiology and pathogenesis of Lyme disease as well as on the genetic organization of the etiologic agent.