Application of type I and II error analysis to support economic decision-making of using an immunomodulator feed additive.

The use of the immunomodulator OmniGen- AF® (OMN) feed supplement, where the response in milk yield, health, and reproduction is uncertain, allows for an application of type I (use the product when it is not profitable) and type II (do not use the product when it is profitable) analysis to aid decision making regarding its profitability. This study applies a type I and II error analysis to quantify the economic risk of investing in OMN feed supplementation using data from a controlled study and a field data set collected on dairy farms. Four prediction models were applied considering the expected value and standard deviation of the response in milk yield; milk and health; milk and reproduction; milk, health, and reproduction. Uncertainty in the milk response was modeled following a normal distribution with mean 0.15 kg/cow/d and standard deviation 0.81 kg/cow/d. This distribution was left-truncated at 0 kg, which resulted in a mean (expected) response of 0.7 kg/cow/d. Based on the field data set, the reduction in health costs and reproduction were estimated at $0.086 and $0.33/cow/day. All 3 responses were assumed to be present or not in the first 90 DIM. The increase in milk yields necessary to pay for the OMN supplementation considering a response in milk yield only, milk and health, milk and reproduction, and milk, health, and reproduction were 0.45, 0.19, -0.56, and -0.82 kg/cow/d respectively. The break-even OMN cost per cow per day when considering the increases in milk yield, milk and health, and milk and reproduction, milk, health, and reproduction were $0.23, $0.31, $0.56, and $0.65 respectively. Production responses resulted in costs exceeding revenue with a type I error cost of $2.62 for milk and $0.47 for milk and health response for the broke even. There was no type I error cost associated when considering the responses in milk and reproduction, and the combination of milk, health and reproduction which implies that there is no risk of using OMN when it is not profitable ( = the product is profitable for certain). Type II costs were associated with returns that are unrealized because of failing to use OMN when it is profitable with an opportunity cost of $9.92, $15.53, $37.23, and $45.08 per cow per day for the responses in milk yield; milk and health; milk and reproduction; and milk, health, and reproduction respectively. We concluded that a type I and II error analysis applied to the use of the OMN feed additive provided additional insights beyond a break-even analysis to support economic decision-making when the response on dairy farms is uncertain. The type I and II error analysis can aid in decision-making process to evaluate the adoption of a new technology.

Rethinking Conservative Treatment of Humeral Diaphyseal Fractures in Elderly Patients With Dementia.

OBJECTIVES: To assess outcomes and complications of conservatively managed humeral diaphyseal fractures in elderly patients, with an emphasis on the subgroup diagnosed with dementia. DESIGN: Retrospective. SETTING: Upper extremity surgery unit at an academic Level I trauma center. PATIENTS/PARTICIPANTS: Consecutive patients 65 years of age and older who were managed conservatively for humeral diaphyseal fractures between 2007 and 2015. INTERVENTION: Conservatively managed humeral diaphyseal fractures. MAIN OUTCOME MEASUREMENTS: Complications and radiographic outcomes. RESULTS: One-hundred twenty-four patients who were conservatively managed for humeral diaphyseal fractures were identified. Their mean age was 77 (65-92) years, 36 (30%) of them were male and 88 (70%) were female. Fifty-seven (46%) patients experienced complications associated with their treatment, and 33 (27%) patients were eventually treated surgically. Seventeen (14%) patients were diagnosed with dementia. This subgroup had 64% fracture-related complications, and all of them were operated (P-value <0.01 compared with age-matched patients among the other 107 participants in the study). CONCLUSION: Conservative management of humeral diaphyseal fractures seems to be associated with greater morbidity in elderly patients, especially in those diagnosed with dementia. Therefore, early surgical treatment should be considered. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Addressing posterior tilt displacement during surgery to lower failure risk of sub-capital Garden types 1 and 2 femoral fractures.

INTRODUCTION: Sub-capital femoral fractures (SCFF) are impacted or non-displaced in Garden types 1 and 2, respectively. Non-surgical treatment is protected weight-bearing combined with physiotherapy and radiographic follow-up in selected patients. Traditionally, in situ pinning is the surgical treatment of choice. The aim of this study was to estimate whether the valgus deformity in Garden types 1 and 2 (AO classification 31B1.1 and 31B1.2) SCFF is a virtual perception of a posterior tilt deformity and if addressing this deformity improves patients' outcomes. MATERIALS AND METHODS: The records of 96 patients with Garden Types 1 and 2 SCFF treated in tertiary medical center between 1/2014 and 9/2017 were retrospectively reviewed. They all had preoperative hip joint anteroposterior and lateral radiographic views. 75 patients had additional computed tomography (CT) scans. Femoral head displacement was measured on an anteroposterior and axial radiograph projections and were performed before and after surgery. Preoperative 3D reconstructions were performed for a better fracture characterization, and assessment of the imaging was performed by the first author. RESULTS: The average age of the study cohort was 73 years (range 28-96, 68% females). There were 58 right-sided and 38 left-sided fractures. Ninety patients had Type 1 and six patients had Type 2 fractures. The average preoperative posterior tilt was 15 degrees and the average valgus displacement was 10 degrees on plain radiographs compared to 28 degrees and 11 degrees, respectively, on CT scans. Posterior tilt was found with a virtual perception as valgus-impacted fractures. The postoperative posterior tilt was corrected to an average of 3 degrees and the valgus displacement to 5 degrees. CONCLUSION: CT provides an accurate modality for measuring femoral head displacement and fracture extent. The posterior tilt displacement should be addressed during surgery to lower failure risk and the need for additional procedures. IRB APPROVAL: TLV-0292-15. LEVEL OF EVIDENCE: IV.

Expandable Proximal Femoral Nail versus Gamma Proximal Femoral Nail for the treatment of hip reverse oblique fractures.

BACKGROUND: Reverse oblique intertrochanteric fractures are classified by the AO/OTA as 31A3 and account for 2-23% of all trochanteric fractures. The Gamma 3-Proximal Femoral Nail (GPFN) and the Expendable Proximal Femoral Nail (EPFN) are among the various devises used to treat this fracture. The aim of this study was to compare outcomes and complication rates in patients with AO/OTA 31A1-3 fractures, treated by either a GPFN or an EPFN. PATIENTS AND METHODS: A total of 67 patients (40 in the GPFN group and 27 in the EPFN group, average age 78.8 years) were treated in our institution between July 2008 and February 2016. Data on postoperative radiological variables, including peg location and tip-apex distance (TAD), as well as orthopedic complications, such as union rate, surgical wound infection and cut-outs rates were also recorded, along with the incidence of non-orthopedic complications and more surgical data. Functional results were evaluated and quantified using the Modified Harris Hip Score (MHHS) and by the Short Form 12 Mental Health Composite questionnaire (SF-12 MHC) in order to assess the quality of life. RESULTS: The total prevalence of postoperative orthopedic complications including postoperative infection showed a significant difference with a p-value of 0.016 in favor of the EPFN group. Nonetheless, the frequency of revision did not differ between the two groups, being 0.134. The main orthopedic complication in both groups was head cut-out of the GPFN lag screw and the EPFN expendable peg, which was 20% and 7.4%, respectively, and required a revision surgery using a long nail or total hip replacement (THR). However, the average TAD did not significantly differ between groups which might be due to a relatively low cohort to reach a significant difference. Nonunion rate of 5% occurred solely in the GPFN group, with similar results of intraoperative open reduction between both groups. The EPFN group achieved better scores in both questionnaires (p = 0.027 and p = 0.046, respectively). Both the MHHS and SF-12 MCS values significantly differed between groups, with the EPFN group achieving better scores than the GPFN group in both questionnaires (p = 0.027 and p < 0.05, respectively). CONCLUSIONS: According to this study, the EPFN yields better results in comparison with the GPFN, with relatively less complications rate, for the treatment of unstable reverse oblique pertrochanteric fracture. In light of this results, we conclude that the EPFN might be as good as GPFN for the treatment of reverse oblique intertrochanteric fractures. LEVEL OF EVIDENCE: Level III retrospective study. The local institutional review board of the Tel Aviv Medical Center approved this study and all the surgeries were done exclusively in this institution.

An immunomodulatory feed additive enhances in vitro viral vaccine recall antigen responses in dairy heifers.

Enhancing immunological responses to vaccination is an important goal in many herd health management systems. OmniGen-AF®(OG) is an immunomodulatory feed additive that has been shown to enhance innate immune function in ruminants and its effects on adaptive immunity require additional study. The objective of this study was to evaluate post-vaccine antibody titers and circulating cellular memory development in heifers fed OG and administered a commercially available modified-live bovine respiratory disease (BRD) vaccine. Twenty-four Holstein heifers were assigned to one of two diets for 170 days: Control TMR (CON; n = 11), or TMR plus OG (TRT; 9 g/100 kg BW/day; n = 13). Samples for hematology, serology, and cellular assays were collected on D-110, 0, 21, 42, and 60 of the trial. Heifers were administered two priming doses of a modified-live BRD vaccine, with a third dose given on D0. There were no significant differences in total WBC and absolute number or the percentage of circulating lymphocytes, monocytes, neutrophils, RBC, or platelets on D-110 through D21. On D42 and D60, CON had significantly higher numbers of lymphocytes. On D0, mean serum neutralizing (SN) titer to BHV-1 was significantly higher for CON compared to TRT. SN titers were not significantly different between CON and TRT at any other time point for BHV-1, BVDV type 1, or BVDV type 2. TRT mounted a significantly stronger recall proliferative response to 0.5 multiplicity of infection (MOI) of BHV-1, BVDV type 1 and BVDV type 2 on D42 and D60; 0.25 MOI of BVDV type 1 on D21 and D42; and 0.25 MOI BVDV type 2 on D42 compared to CON. IL-4 production induced by 0.5 and 1.0 MOI BHV-1 (D42 and D60); 0.25 MOI of BVDV type 1 (D21); and 0.25 and 0.5 MOI of BVDV type 2 (D60) were significantly higher for TRT than CON. IL-17 production induced by 0.25 MOI of BVDV type 1 was significantly higher on D60 for TRT compared to CON. IFN-gamma and IL-10 were not significantly different between treatments. These data indicate feeding OG has a beneficial effect on responses to vaccine antigens in Holstein dairy heifers.

Correlation between preoperative imaging parameters and postoperative basic kinematics-based functional outcome in patients with tibial plateau fractures.

BACKGROUND: Functional scores and radiographs are often used to assess function and predict development of osteoarthritis in patients with multi-fragmentary tibial plateau fractures (TPFs). Locomotion, which is the primary goal of fracture treatment, is rarely assessed. The objective of this study was to assess functional ability of patients after TPF fixation using spatio-temporal gait analysis (STGA), and to compare STGA variables with self-reported functional scores and preoperative fracture characteristics. METHODS: Preoperative CT scans of 21 patients with complete articular multi-fragmentary TPFs were evaluated for number of fragments, maximum gap between the fragments and maximum articular depression. All patients underwent STGA (velocity, cadence, step length of the affected and the unaffected leg, single-limb support by the affected and the unaffected leg, and double-leg support) and filled the Knee Society Score and the Short Form-12 questionnaires on average 3 years (SD = 1.56, range, 2-5.8) post-injury. FINDINGS: Step length and single-limb support time of the affected leg were shorter compared to the unaffected leg (p = 0.02 and p = 0.007, respectively). Number of fracture fragments correlated with cadence (R = -0.461, p = 0.04) and velocity (R = -0.447, p = 0.04). INTERPRETATION: Given that both higher fracture comminution and deformity on the one hand and the above gait parameter alterations on the other hand are associated with knee osteoarthritis, STGA may be used for routine postoperative evaluation of patients after TPF fixation.

Effects of an immunomodulatory feed additive on intramammary infection prevalence and somatic cell counts in a dairy herd experiencing major health issues.

A trial was conducted to determine if feeding OmniGen-AF® (OG) to 22 late lactation cows 60 days prior to and during the early dry period, a time of increased susceptibility to mastitis, could reduce disease incidence in a dairy herd experiencing major health issues. Treated cows (n = 11) consumed a ration containing OG [9 g/100 kg of body weight/day] beginning 60 days before dry-off, during the dry period, and through 30 days in milk (DIM). Control cows received the same ration during the dry period through 30 DIM only. Body weights, body condition scores (BCS), intramammary infection (IMI) prevalence, new IMI rates, somatic cell counts (SCC), milk yield, and adverse health events were measured. No differences were found between treatments for body weight or BCS. Adverse health event data at calving showed no differences between treatments except for percentage of cows with hyperketonemia, which was lower among treated cows (63.6% vs 100%). Prevalence of IMI from calving through 30 DIM for treated cows (6.1%) was lower than controls (11.05%); likewise, new IMI rate during this time for treated cows (0.61%) was lower than controls (5.81%). The SCC from calving through 30 DIM for treated cows (215,000/ml) was lower than controls (493,000/ml). Average production/day at the first DHIA test (~33 DIM) showed that treated cows produced more milk (39.9 kg) than controls (35.34 kg). In conclusion, feeding OG 60 days prior to dry-off reduced hyperketonemia and mastitis, lowered SCC, and numerically increased milk yield in a dairy herd experiencing major health issues.

Safety of urgent hip fracture surgery protocol under influence of direct oral anticoagulation medications.

INTRODUCTION: Direct oral anticoagulation agents (DOACs) are increasingly prescribed to older adults. Concerns for perioperative blood loss dictate cessation of anticoagulation treatment and postponement of surgery until the coagulation system returns to normal state. The goal of this study is to compare the estimates of perioperative blood loss and mortality between patients using DOACs and patients receiving no anticoagultaion, in order to challenge the existing policy and question the need for surgery deferral. MATERIALS AND METHODS: This is a retrospective cohort of patients (age > 65) with proximal hip fractures treated with either closed reduction internal fixation (CRIF, n = 1143; DOAC use n = 60) or hemiarthroplasty (HA, n = 571; DOAC use n = 29). Baseline patient characteristics included age, gender, ASA score, socioeconomic level, type of surgica#1: In general a l treatment, duration of surgery and time from admission to surgery. The effect of anticoagulant prescription on percentage of hemoglobin change, odds of receiving blood transfusions and one-month and one-year mortality was evaluated separately for CRIF and HA patients. RESULTS: Patients receiving DOACs had similar perioperative hemoglobin change, transfusion rates and mortality, compared to subjects without anticoagulants in both CRIF and HA cohorts. DOAC patients undergoing CRIF had a longer delay to surgery (40.2 ± 26.9 vs 31.2 ± 22.2, p = 0.003) and higher mortality rates at one year postoperatively (26.7% vs 16.1%, p = 0.015). CONCLUSIONS: DOAC use was not associated with an increased perioperative blood loss or mortality compared to controls. However, they had to wait longer for surgery, which itself was an independent predictor of mortality. It may be safe to shorten waiting time for surgery in patients using anticoagulation, with the goal to minimize surgery delay.

Financial impact and effect on the outcome of preoperative tests for at-risk older hip fracture patients.

AIM: Older patients with proximal femoral fractures often undergo preoperative tests due to coexisting morbidities. Our aim was to evaluate these tests and their impact on patient outcome and medical expenses. METHODS: This retrospective study includes data on head computed tomography, carotid ultrasound, echocardiography and pulmonary functional tests calculated according to the type of surgery (osteosynthesis or hip arthroplasty) carried out on 2798 patients. Time-to-surgery, test repeated postoperatively, American Society of Anesthesiology Physical Status score, additional procedures, hospitalization time, 30-day mortality and associated medical expenses were evaluated. RESULTS: A total of 921 preoperative tests were carried out in 780 (28%) patients, and 375 postoperative tests were carried out in 329 (12%) patients (P < 0.001). A total of 23 procedures were carried out after surgery, none related to the originally carried out tests. Significant group differences were found for American Society of Anesthesiology Physical Status score, days to surgery, hospitalization time (days) and mortality rates. The medical expenses of these tests were 1.3% of the average income per case, and 0.6% of the average study group income. CONCLUSIONS: Non-routine preoperative tests prolong time-to-surgery, increased hospitalization time and contribute to 30-day mortality. No postoperative procedure was related to preoperative test findings. The financial cost for these tests does not burden the medical expenses per procedure. Geriatr Gerontol Int 2018; 18: 937-942.

Functional outcomes after removal of hardware in patellar fracture: are we helping our patients?

PURPOSE: Functional outcomes after Open Reduction Internal Fixation (ORIF) of the patella are variable. Common complications of patella ORIF include persistent anterior knee pain, limited range of motion and symptomatic hardware. The purpose of this study was to evaluate if removal of hardware is beneficial to symptomatic patients after patellar fracture fixation. METHODS: Patients who presented to our institution between December 2006 and November 2014 with patella fractures treated with ORIF were eligible for inclusion. Patella ORIF was performed using (1) K-wires (KW) with a tension band construct or (2) Cannulated Screws (CS) with a tension band construct. Radiological analyses included (1) AO classification and (2) measurements of prominent hardware length. Patient medical charts were reviewed for demographic and intraoperative data as well as peri/postoperative complications. All patients completed the SF-12 score, visual analog scale, Kujala score, Lysholm score and questionaries' regarding return to previous activity levels. RESULTS: Forty-seven patients met the inclusion criteria. The average time from fracture fixation to removal of hardware was 15.8 (SD ± 14.9) months. The mean follow-up was 43.1 (SD ± 27.1) months. Patella fixation was accomplished using tension band constructs with KW in 28 patients (59.5%) or with CS in 19 patients (40.5%). Patient reported quality of life and pain outcomes improved significantly after removal of hardware (p = 0.001, and p = 0.002 respectively). Functional outcome scores (Kujala and Lysholm) did not improve significantly after hardware removal in the KW or CS groups. Significantly more patients in the KW group returned to pre-injury activity (p = 0.005). CONCLUSIONS: Hardware removal after patella ORIF significantly improves patient reported pain and quality of life outcomes but not functional outcomes. Patients should be counseled regarding the expected outcome of hardware removal following patella ORIF and diabetic patients should be given special consideration before undergoing this procedure.

A double-plating approach to distal femur fracture: A clinical study.

BACKGROUND: Locked plating is one of the latest innovative options for treating supracondylar femur fractures with relatively low failure rates. Single lateral plating was often found to have a relative higher failure rate. No clinical studies of double-plating distal femur fixation have thus far been reported. The aim of this study is to present our clinical experience with this surgical approach. PATIENTS AND METHODS: Thirty-two patients (26 females and 6 males, mean age 76 years, range 44-101) were included in the study. Eight of them patients had a periprosthetic stable implant fracture and two patients were treated for a nonunion. RESULTS: All fractures, excluding one that needed bone grafting and one refracture, healed within 12 weeks. One patient needed bone grafting for delayed union and one patient needed fixation exchange due to femur re-fracture at the site of the most proximal screw. Two patients developed superficial wound infection and one patient required medial plate removal after union due to deep infection. CONCLUSIONS: Based on these promising results, we propose that the double-plating technique should be considered in the surgeon's armamentarium for the treatment of supracondylar femur fractures, particularly in patients with poor bone quality, comminuted fractures and very low periprosthetic fractures.

Abrupt Decline in a Protected Population of Siamangs (Symphalangus syndactylus) in Southern Sumatra.

Between 2011 and 2016, approximately 50% of siamangs in the Way Canguk Research Area disappeared, including members of 7 of 12 habituated groups. Demographic data from 1998 to 2015 confirm that the population decline in the habituated groups reflects a larger trend in the local population. There was no evidence of hunting of primates in the area, and ecological data do not suggest substantial changes in food availability or predation pressure during this period. From 2011 to 2014, we monitored the habituated groups only intermittently, and most deaths or disappearances were not observed. However, in 2014-2016, we monitored some groups more intensively, and observed 2 individuals with symptoms including whitened skin on the face, hands, and abdomen, hair loss, swelling of the face, frequent scratching, and lethargy. One affected individual disappeared days after this observation, while the other survived. The spatiotemporal pattern of disappearances in the habituated groups was consistent with that expected if the deaths resulted from disease transmission among neighbouring groups. Thus, the available evidence, while preliminary, suggests that a local disease epizootic may have been a factor driving the population decline. We recommend that researchers establish monitoring protocols to better understand primate disease epidemiology and to guide conservation management.

Corona mortis anastomosis: a three-dimensional computerized tomographic angiographic study.

PURPOSE: We evaluated the corona mortis (CM) anatomy by means of three-dimensional computerized tomography angiographic (CTA). METHODS: Patient demographic, anastomosis incidence, artery diameter, artery distance from the symphysis pubis, and pelvic size (distance between both acetabular upper labrum) parameters were assessed. The 100 patients included 66 males and 34 females (average age of 67.8 years). RESULTS: There were 66 (33%) arterial anastomoses in the 200 evaluated arteries, 30 in the right side and 36 in the left side, 36 unilaterally and 15 bilaterally. No anastomoses were detected in 49 patients. The average diameter was 2.4 mm for the right-sided arteries and 2.24 in the left-sided ones. The distance was 55.2 mm from the right symphysis and 57.2 from the left symphysis (greater for females, 62.2 versus 55.85 mm [p = 0.037] only on the left side). The artery disappears in smaller-sized pelvises. There was a non-occluded arterial pattern in 47 (71%) and a partially occluded one in 19 (29%, all with peripheral vascular disease). CONCLUSION: One-third of the evaluated CTAs revealed competent CMs. CMs were more lateral in females than in males and were absent in small-sized pelvises. It is highly recommended that the radiologist and the surgeon should be familiar with CM existence for decision-making with regard to emergency radiology imaging and intervention as well as when operating in proximity of that anatomic site.

The Role of Opportunistic Bilateral Salpingectomy vs Tubal Occlusion or Ligation for Ovarian Cancer Prophylaxis.

Bilateral tubal ligation (BTL) for sterilization has been known to decrease the risk of ovarian cancer. Recent studies have suggested that bilateral salpingectomy (BS) may be an alternative to BTL or tubal occlusion for women desiring permanent sterilization, owing to a possibly greater protective effect against ovarian cancer. We conducted a PubMed/MEDLINE review of the literature for original studies, opinion articles, and meta-analyses published between 2010 and 2016 addressing the role of BS at the time of sterilization and comparing its efficacy with BTL in terms of ovarian cancer prevention, operative outcomes, and ovarian function. BTL has been found to decrease the risk of any ovarian cancer by 13% to 41%, compared with 42% to 78% for BS. Although operative time is increased with BS compared with BTL, no differences in complication rates or ovarian reserve between the 2 procedures have been demonstrated. Our review suggests that BS should be discussed when BTL is being considered, and that patients should be counseled about the risks and benefits of both procedures based on the current available evidence.

In vivo electrical application on titanium implants stimulating bone formation.

BACKGROUND AND OBJECTIVE: The aim of the present in vivo study was to measure the bone implant contact area after electrical stimulation of dental implants. MATERIAL AND METHODS: Ninety titanium dental implants (6 mm × 11.5 mm) with a smooth surface were placed in six male Beagle dogs and then the implant-bone interfaces was assessed by histological analyses after 7 and 15 d. The 12-mo-old dogs, with a weight of 15 kg, were randomly divided into two groups based on the duration of bone healing: 7 and 15 d. Also, implants were divided into three groups based on electrical stimulation: group A, 10 µA; group B, 20 µA; and group C, control group. The electrical current was applied by an electrical device coupled to the implant connection. RESULTS: After 7 d of electrical stimulation, no statistical differences in bone-implant interface contact area were observed. However, a significantly higher bone-implant interface contact area was recorded for group B than for groups A and C (p < 0.01) after 15 d. No statistical difference was observed between groups A and C (p > 0.05). CONCLUSION: The electrical stimulation of dental implants can generate a larger area of bone-implant interface contact as a result of bone formation. Factors such as different electrical current intensity and duration should be studied in further work to clarify the potential of this method.

Preoperative Planning of Orthopedic Procedures using Digitalized Software Systems.

The progression from standard celluloid films to digitalized technology led to the development of new software programs to fulfill the needs of preoperative planning. We describe here preoperative digitalized programs and the variety of conditions for which those programs can be used to facilitate preparation for surgery. A PubMed search using the keywords "digitalized software programs," "preoperative planning" and "total joint arthroplasty" was performed for all studies regarding preoperative planning of orthopedic procedures that were published from 1989 to 2014 in English. Digitalized software programs are enabled to import and export all picture archiving communication system (PACS) files (i.e., X-rays, computerized tomograms, magnetic resonance images) from either the local working station or from any remote PACS. Two-dimension (2D) and 3D CT scans were found to be reliable tools with a high preoperative predicting accuracy for implants. The short learning curve, user-friendly features, accurate prediction of implant size, decreased implant stocks and low-cost maintenance makes digitalized software programs an attractive tool in preoperative planning of total joint replacement, fracture fixation, limb deformity repair and pediatric skeletal disorders.

Control of the micromovements of a composite-material nail design: A finite element analysis.

BACKGROUND: Intramedullary nail fixation is the most accepted modality for stabilizing long bone midshaft fractures. The commercially used nails are fabricated from Stainless Steel or Titanium. Composite-materials (CM) mainly carbon-fiber reinforced polymers (CFRP) have been gaining more interest and popularity due to their properties, such as modulus of elasticity close to that of bone, increased fatigue strength, and radio-opacity to irradiation that permits a better visualization of the healing process. The use of CFRP instead of metals allows better control of different directional movements along a fracture site. The purpose of this analysis was to design a CM intramedullary nail to enable micromovements as depicted on a finite element analysis method. METHODS: We designed a three-dimentional femoral nail model. Three CFRP with different laminates arrangements, were included in the analysis. The finite element analysis involved applying vertical and horizontal loads on each of the designed and tested nails. RESULTS: The nails permitted a transverse micromovement of 0.75mm for the 45° lay-up and 1.5mm for the 90° lay-up for the CM, 1.38mm for the Titanium and 0.74mm for the Stainless Steel nails. The recorded axial movements were 0.53mm for the 45° lay-up, 0.87mm for the 90° lay-up, 0.46mm for the unsymmetrical lay-up CM, 0.046 for the Titanium and 0.02 for the Stainless Steel nails. Overall, the simulations showed that nail transverse micromovements can be reduced by using 45° carbon fiber orientations. Similar results were observed with each metal nails. INTERPRETATION: We found that nail micromovements can be controlled by changing the directional stiffness using different lay-up orientations. These results can be useful for predicting nail micromovements under specified loading conditions which are crucial for stimulating callus formation in the early stages of healing.

Anchor suture fixation of distal pole fractures of patella: twenty seven cases and comparison to partial patellectomy.

PURPOSE: Partial patellectomy (PP) and reattachment of the patellar ligament with transosseous suturing is the mainstay of surgical treatment for distal pole patellar fractures. An anchor suturing (AS) technique has recently been reported as an alternative to PP in such fractures and allows for bone-to-bone interface and possibly superior fracture healing than bone-to-tendon interface with PP. We present our experience with AS and compare it to PP. METHODS: Between 2006 and 2011, 60 patients with distal pole patellar fracture underwent either AS (n = 27) or PP (n = 33). We retrospectively gathered their demographic data and information on fracture type, fixation technique, operation time, postoperative complications and knee range of motion. A telephone survey was performed to grade functional outcomes with standard questionnaires (the SF-12 for quality of life, the Kujala score for patellofemoral function and a visual analog scale [VAS] pain score). RESULTS: AS was equivalent to PP in terms of residual pain and functional outcomes (VAS: 2.45 vs. 2.26, p = 0.83 and Kujala score: 74.3 vs. 69, p = 0.351, respectively) as well as for knee range of motion. Complications included three cases of infection in each group, two cases of early hardware failure and one case of non-union in the AS group. Operation time was significantly shorter for AS compared to PP (68.5 vs. 79.1 min, p = 0.03). CONCLUSIONS: AS is non-inferior to PP for function and pain after distal pole patellar fractures and is superior to PP with regard to operative time. Common complications of this technique are hardware failure and infections. LEVEL OF EVIDENCE: Therapeutic Level III.

Dynamic locking plate vs. simple cannulated screws for nondisplaced intracapsular hip fracture: A comparative study.

INTRODUCTION: Intracapsular hip fractures (ICHF) are a common cause of morbidity and mortality and pose a great economic burden on the health care systems. Appropriate surgical treatment requires balancing optimal outcomes with the cost of treatment to the health care system. While in elderly patients with displaced ICHF arthroplasty became the standard of care, the internal fixation method for conserving the femoral head in younger patients or in nondisplaced ICHF is still in debate. We compared a dynamic locking plate with the standard cancellous cannulated screws (CCS) for treatment of nondisplaced ICHF. METHODS: All patients treated with internal fixation for nondisplaced ICHF between July 2009 and December 2012 at our level one trauma center were included in this study. Patients treated with Targon FN (Aesculap) implants and CCS (Synthes) were compared. Charts were reviewed for demographics, intraoperative data and peri/post operative complications retrospectively. Radiographical analysis, pain (VAS), quality of life (SF12) and function (MHHS) data were prospectively gathered. RESULTS: One hundred and fifteen non-displaced ICHFs were treated with internal fixation, 81 with CCS and 34 with Targon FN implant; the mean follow-up was 19 and 28 months, respectively. Group fracture characteristics (Garden/Powel classification), and demographics, excluding age, were not significantly different. Post-operative revision rates of the Targon FN and CCS groups, perioperative complications were not statistically different (p>0.05). Quality of life (SF-12), function (Modified Harris Hip Score) and Visual Analogue Scale (VAS) pain scores were not statistical different. CONCLUSIONS: Complication rates and clinical outcomes for the treatment of nondisplaced ICHF with Targon FN and SCC showed no significant differences. Based on this evidence in consideration of the substantial cost differential between the Targon FN and SCC we suggest SCC for treatment of nondisplaced ICHF. LEVEL OF EVIDENCE: III.

Limb position significantly affects safety distance during cast removal.

BACKGROUND: Unintentional cast saw injuries are attributable to casting material or improper removal technique. Another factor associated with the risk of injury is the "safety distance," the distance between the inner perimeter of the cast and the patient's skin. METHODS: Nine patients with lower leg casts around the knee/ankle were examined. Safety distance was measured using a standard depth gauge at 6-10 spots along the limb. The safety distance at each spot was measured in both supine and lateral-decubitus positions. Limb position was termed "safe" with the saw coming directly from above; a "dangerous" position was considered when the saw was coming from the side. RESULTS: The mean safety distance in the "safe position" was 17.02 mm ± 4.66 mm, compared with 14.34 mm ± 3.85 mm in the "dangerous position" (Δ = 2.7 mm; p < .0001). CONCLUSIONS: Proper positioning of a patient during cast-splitting, with the saw in the nondependent, safe aspect of the limb, can significantly increase the safety distance and minimize skin injuries.