Introduction: We state that preserving the hip might be optimum in treatment of patients with dislocated femoral fractures presuming that the fractures unite. In order to be able to choose the right treatment for the patient with a dislocated femoral neck fracture, we have hypothesized that lack of blood flow and development of ischemia might have influence on outcome of the osteosynthesis. In this study we have established microdialysis and laser Doppler measurements in patients with a dislocated femoral neck fractures. Methods and materials: 14 patients with dislocated fractures of the femoral neck were osteosynthezised by using 2 cannulated screws. During the operation blood flow was measured with laser Doppler in order to detect pulsatile flow, and microdialysis was performed to detect ischemia. Both measurements were made in the femoral head and with the greater trochanter as control. The parameters measured were lactate, pyruvate, glycerol and glucose concentrations. Lactate/pyruvate ratio was calculated in order to estimate ischemia defined as a value over 25. Measurements were done after the fracture was reduced, and during osteosynthesis. Data are presented as mean with standard deviation (SD) in brackets. Results: In all but one patient laser Doppler showed pulsatile flow in the greater trochanter, whereas 8 patients had flow in the femoral head. In the greater trochanter the mean lactate/pyruvate ratio was 11 (7.55), in the femoral heads the mean ratio was 27.99 (21.24) although 4 heads did not show ischemia (p=0.0004). The values for glucose in the trochanter and the femoral head are 2.47 mM(1.92) and 1.53 mM(1.37) respectively, and for glycerol 0.16 mM(0.09) and 0.25 mM(0.22). During the observation period two patients were reoperated, one with hemiarthroplasty 3 months after the osteosynthesis due to failure of the osteosynthesis; the patient had flow measured by laser Doppler and ischemia with microdialysis. One had a resection arthroplasty due to infection. Conclusion: To our knowledge it is the first time that laser Doppler and microdialysis has been established in patients with dislocated femoral neck fractures. Further studies will have to evaluate whether laser Doppler and microdialysis in combination with fracture related parameters can predict failure of the osteosynthesis. This might enable us to establish a treatment algorithm to be used in the daily clinic

Aim: Despite many studies the implications of perfusion and blood flow abnormalities in the rotator cuff (RC) in vivo are not clearly understood. Laser Doppler Flowmetry (LDF) is an established technique for the measurement of perfusion in tissue, which has been applied in animal and human studies. This study aims to evaluate Laser Doppler Flowmetry (LDF) as a technique for the assessment of blood flow in the normal and diseased RC. Methods: With Ethics committee approval and informed consent patients undergoing arthroscopy for impingement or cuff tear (diseased cuff) and instability (normal cuff – BO) were recruited. Following diagnostic arthroscopy and bursoscopy measurements of the LDF in the RC tear were made at 6 points. Five of these were in the cuff over a 4 cm. 2 are from the insertion at the greater tuberosity and one in the deep surface. Diseased RC were sub grouped into mild (B1), moderate (B2) and severe (*B3 – cuff tear) impingement grades (Copeland – Levy Classification). The arthroscopy, grading, and probe placement were made by the senior authors. LDF flux (LDFf) was recorded over 30 seconds at each measurement point. The mean of these readings was then calculated (LDF flux – an arbitrary unit of measurement of the perfusion). Results: 35 patients were recruited. 210 measurements were recorded, in 6 anatomical locations. The mean LDFf was 34.1 in diseased RC and 55.3 in normal RC (p=0.0002). The mean LDFf was 52.2 in severe (RC tear) impingement and 30.3 in mild and moderate impingement’s (p< 0.0001). The LDFf was lowest in the moderate grade with a significant increase at the edges of a cuff tear. Conclusion: Preliminary recording of LDFf show changes are in keeping with current knowledge of the pathology. LDFf decreases with advancing impingement. There is an increase in LDFf at the edges of RC tears. This might reflect a reparative response

Introduction: Laser Doppler Flowmetry (LDF) is an established technique for the measurement of perfusion in tissues, which has been applied in animal and human studies. Despite many studies the implications of perfusion and blood flow abnormalities in the rotator cuff (RC) in vivo are not clearly understood. This study aims to assess the blood flow in the normal and diseased RC using Laser Doppler Flowmetry (LDF) technique. Methods: With Ethics approval and informed consent patients undergoing arthroscopy for impingement or cuff tear (diseased cuff) or for shoulder instability (normal cuff) were recruited. Following diagnostic arthroscopy and bursoscopy measurements of the blood flux in the RC using the LDF were made at 6 points. Five of these were in the cuff over a 4 cm. 2. area from the insertion at the greater tuberosity (A,E – @ Tuberosity level, C-Muscelotendinous junction, B,D – between the two) and one (F) in the deep surface. Diseased RC were subgrouped into mild (B1), moderate (B2) and severe (B3- cuff tear) impingement grades (Copeland-Levy Classification). The arthroscopy, grading, and probe placement were made by the two senior authors. LDF flux (unit of measurement of the perfusion – LDFf) was recorded over 30 seconds at each measurement point. The mean of these readings was calculated. Results: 56 patients were recruited. 35 Males (62.5%) and 21 Females (37.5%). 336 measurements were recorded. The observed mean LDFf was 32.8 (27.4–38.1; 95% CI) , 25.4 (22.4–28.5) and 43.1 (37.8–48.4; 95% CI) For Normal, Impingement and Tear cases, respectively (p< 0.0001, One-way ANOVA). The LDFf was lowest in the Impingement without tear grade (B2) with a statistically significant increase at the edges of a cuff tear. Conclusion: Preliminary recordings of LDF show changes are in keeping with current knowledge of the pathology. LDFf decreases with advancing impingement, being least affected in the musculotendinous junction. There is a substantial increase in LDFf at the edges of RC tears. This might reflect an attempted reparative response

Introduction: Open lower leg fractures are frequently associated with severe soft tissue damage. Cortical bone tissue is thus denudated. Osteomyelitis and impaired circulation with loss of bone tissue with subsequent defects are among the main complications, arising from the condition. Surfacing bone is judged on its perfusional conditione solely by the surgeon. Minor bleedings with decortication of the respective cortical bone serve as parameter for the clinical assessment and subsequent therapeutic decisions. Methods: 80 inbred white New Zealand rabbits with two groups of 40 animals each were employed. Each animal had a tibial fracture induced in a standardized fashion, stabilized by screw osteosynthesis. The fracture area was freed from soft tissue and periost and the medullary space reamed. After 3 or 7 days (group one or two, respectively), the tissue defect was covered by a local fascia-free gastrocnemius muscle flap. In increasing intervalls from one to 16 weeks, the implants were removed and the animals euthanized. At all three interventions, cortical microcirculation was measured by two-channel laser doppler flowmetry (LDF), counting erythrocyte flux as product of erythrocyte velocity with number of erthrocytes observed. Observed were cortical bone of the fragment created and of the adjacent cortical bone with and without periostal linig. The bone was removed after euthanisation and analysed histo-morphologically. All animals were kept in accordance with the procedures outlined in the “Guide for the Care a. Results: A muscle flap after three days led to significantly better perfusion as compared to 7 days with 24 vs 10 flux (mean +/− SEM; p < 0,05, paired t-test; baseline 1,4 flux ), resembling almost healthy values. Simultaneously, flap covering after three days displayed a lower rate of necroses with 23 vs. 40 % (p < 0,05, paired t-test). Incidence of osteomyelitis was as well higher in the 7-days-group (24%). Improved microcirculation as well as lower rate of infection were associated with the induction of neoperiost from the muscle flap. Discussion: Delayed plastic covering of open lower leg fractures led to delayed healing as well as infection in our experimental setting. Two-channel doppler was a reliable and little invasive means for the objective evaluation of conditions, associated with experimental open fractures. Identification of less vital tissue could lead to reduction in the loss of vital bone tissue in clinical settings without the hazard of active decortication. Again, a vital periost has been proved to be the one central aspect of bone healing

Introduction: It is unknown what effect distraction osteogenesis has on bone blood flow to the affected limb. Our study analyzed in vivo measurement of tibial blood flow during distraction osteogenesis using Doppler ultrasonography. Materials and Methods: Blood flow was measured in the femoral artery, with Doppler ultrasonography in five people treated with bi-focal tibial distraction osteogenesis. The normal leg was used as the control to correct for differences in cardiac output. Measurements for each leg were taken and means recorded preoperatively, at 1 week postoperatively, and at subsequent intervals up to 6 months. Results: Preoperative blood flow varied from 0.5 – 2.25. All treated legs demonstrated increases in flow from 2.25 – 5.75, with peaks in the first weeks following osteotomy. Significant increases in blood flow during treatment with distraction osteogenesis, confirming previous experimental studies. Discussion: Blood flow plays a significant role in the successful outcome of this treatment. Compression of the non-union at the time of peak blood flow gives more reliable union than bone transport methods, where docking takes place when blood flow has returned towards the control limb

Introduction and Aims: Cerebral micro emboli have been noted to occur during both total hip and knee arthroplasty. These micro emboli have been implicated in the causation of post-operative cognitive impairment. The aim of this study was to determine whether cerebral micro emboli occur during hip fracture surgery. Method: Twenty-eight patients undergoing hip fracture surgery had transcranial doppler assessment of the middle cerebral artery to detect cerebral micro emboli. Micro embolic signals (MESs) were recorded during the operative procedure. Results: Successful monitoring was carried out in 26 patients. MES were recorded in 16 out of 26 patients. Twelve out of 16 patients who had MESs had undergone a cemented hemiarthroplasty, the remainder had a sliding hip screw for an extracapsular hip fracture. Seventy-five percent (9/12) of patients that had a cemented hemiarthroplasty, had the majority of MESs after reaming and cementing. MESs in the patients that had a sliding hip screw occurred throughout the operative procedure. Conclusion: Cerebral micro emboli do occur during hip fracture surgery. These emboli may be responsible for the cognitive dysfunction that occurs in this susceptible group of patients

Cerebral micro emboli have been noted to occur during both total hip and knee arthroplasty. These micro emboli have been implicated in the causation of postoperative cognitive impairment. The aim of this study was to determine whether cerebral micro emboli occur during hip fracture surgery. 28 patients undergoing hip fracture surgery had transcranial doppler assessment of the middle cerebral artery to detect cerebral micro emboli. Micro embolic signals (MESs) were recorded during the operative procedure. Successful monitoring was carried out in 26 patients. MES were recorded in 16 out of 26 patients. 12 out of 16 patients who had MESs had undergone a cemented hemiarthroplasty; the remainder had a sliding hip screw for an extracapsular hip fracture. 75% (9/12) of patients who had a cemented hemiarthroplasty had the majority of MESs after reaming and cementing. MESs in the patients who had a sliding hip screw occurred throughout the operative procedure. Conclusion: Cerebral micro emboli do occur during hip fracture surgery. These emboli may be responsible for the cognitive dysfunction that occurs in this susceptible group of patients

Background: Cerebral micro emboli have been noted to occur during both total hip and knee arthroplasty. These micro emboli have been implicated in the causation of post-operative cognitive impairment. The aim of this study was to determine whether cerebral micro emboli occur during hip fracture surgery. Method: 28 patients undergoing hip fracture surgery had transcranial doppler assessment of the middle cerebral artery to detect cerebral micro emboli. Micro embolic signals (MES’s) were recorded during the operative procedure. Results: Successful monitoring was carried out in 26 patients. MES were recorded in 16 out of 26 patients. 12 out of 16 patients who had MES’s had undergone a cemented hemiarthroplasty the remainder had a sliding hip screw for an extracapsular hip fracture. 75% (9/12) of patients that had a cemented hemiarthroplasty, had the majority of MES’s after reaming and cementing. MES’s in the patients that had a sliding hip screw occurred throughout the operative procedure. Conclusion: Cerebral micro emboli do occur during hip fracture surgery. These emboli may be responsible for the cognitive dysfunction that occurs in this susceptible group of patients

We used a laser Doppler flow-meter with high energy (20 m W) laser (Moor Instruments Ltd. Milwey, UK) to measure the blood flow to the femoral head during resurfacing arthroplasty. Twenty-four hips were studied; 12 underwent a posterior approach and twelve a Ganz's trochanteric flip osteotomy. The approach was determined according to surgeon preference. Three patients were excluded, The exclusion criteria were previous hip surgery, history of hip fracture and avascular necrosis (AVN). All patients had the hybrid implant with cemented femoral component. During surgery a 2.0mm drill bit was passed via the lateral femoral cortex to the superior part of the head neck junction. The position was confirmed using fluoroscopy. The measurements were taken during five stages of the operation: when the fascia lata was opened (baseline), at the end of soft tissue dissection, following dislocation of the hip, after relocation back into the socket, after inserting the implants prior to closing the soft tissues and, finally, at the end of soft tissue closure. The results were analysed and the values were normalised to a percentage of the baseline value. We found a mean drop of 38.6 % in the blood flow during the posterior approach and a drop of 10.34% with the trochanteric flip approach. The significant drop occured between the baseline (1st stage) and the end of the soft-tissue dissection (2nd stage). In both groups the blood flow remained relatively constant afterwards. Our study shows that there is a highly significant drop in blood flow (p<0.001) during the posterior approach compared with the trochanteric flip approach

Introduction: Two major complications of hip resurfacing arthroplasty are avascular necrosis of the femoral head and femoral neck fracture. Both are thought to be precipitated by disruption of the blood supply to the femoral head and neck during the approach to the hip joint. Ganz et al have described their technique of approaching the hip joint using a “trochanteric flip” osteotomy. This has the theoretical advantage of preserving the medial femoral circumflex artery to the femoral head. The aim of this study was to compare the intra-operative femoral head blood flow during the Ganz flip osteotomy to the blood flow during a posterior approach for resurfacing arthroplasty of the hip. Methods: The intra-operative measurements of blood flow were performed using a DRT laser Doppler flow-meter with a 20 mW laser and a fibreoptic probe. The probe was introduced into the lateral femoral cortex and threaded into the femoral head under image intensifier control. Measurements were recorded before the approach to the hip was performed, after the approach was performed but before the head was dislocated, and after the head was dislocated. Results: Our initial results indicate that there is on average a 50% drop in the blood flow to the femoral head after a posterior approach to the hip joint. In contrast, the trochanteric flip osteotomy produces a much smaller fall of around 18%. We have used these results to inform a sample size calculation, and are currently recruiting further patients to achieve a total of 42 in order to confirm a statistically significant effect. Conclusion: The Ganz trochanteric flip osteotomy appears to produce less damage to the blood supply to the femoral head during resurfacing arthroplasty than the posterior approach. This study will inform surgeons in deciding on their preference for a routine approach for hip resurfacing

Previous investigations have postulated that the asymmetry of the breasts in female adolescents may be linked with the development of right convex thoracic scoliosis, although there is no correlation between breast asymmetry and curve type or scoliosis magnitude. This breast asymmetry is supposed to be linked with anatomic and functional asymmetry of the internal mammary artery that is the main supplier to the mammary gland. However, no measurements of anatomic and haemodynamic parameters of internal mammary artery have been made to justify or to reject the hypothesis of asymmetric blood flow volume to the breasts and costosternal junction in female adolescent scoliotics. Twenty female adolescents with right thoracic scoliosis and 16 comparable female individuals without spine deformity were included in this study. Standing roentgenograms of the whole spine were made in all scoliotics to measure scoliosis curve, vertebral rotation and concave and convex rib-vertebra-angle at three vertebrae (apical, one level above and one below the apical vertebra). The Color Doppler Ultrasonography was used to measure at the origin of internal mammary artery its lumen diameter, cross sectional area, time average mean flow and flow volume per minute in scoliotics and controls and were compared each other. The roentgenographic parameters were compared with the ultrasonographic parameters in the scoliotics to disclose any relationship. The reliability of color Doppler ultrasonography was high and the intraobserver variability low (ANOVA, P=0.92–0.94). There was no statistically significant difference in the ultrasonographic parameters of the internal mammary artery between right and left side in each individual as well as between scoliotics and controls. In scoliotics the right mammary artery time average mean velocity increases with the convex and concave rib-vertebra-angle one level above the apical vertebrae (P< 0.01), convex rib-vertebra angle one level below the apical vertebra (P< 0.05), and concave apical rib-vertebra angle (P< 0.01). The left internal mammary artery time average increases with only the convex rib-vertebra angle one level above the apical vertebra (P< 0.05). The right and left internal mammary artery flow volume increases with the convex rib-vertebra-angle one level above the apical vertebra (P< 0.05), while the right internal mammary artery flow volume increases furthermore with the apical concave rib-vertebra-angle (P< 0.01) and concave rib-vertebra angle one level above the apical vertebra (P< 0.01). The concave apical rib-vertebra-angle (P< 0.01) and concave rib-vertebra-angle one level above the apical vertebra (P< 0.01) increases with left internal mammary artery cross sectional area. We concluded that anatomic and haemodynamic flow parameters measured at the origin of internal mammary artery are significantly correlated with apical rib-vertebra-angle in female adolescents suffering from right convex idiopathic thoracic scoliosis. This study did not find any evidence for side-difference in vascularity of the anterior thorax wall thus could not justify previous theories for development of right thoracic scoliosis in female adolescents

Aims: To evaluate the morphologic changes in the patellar tendon 10 years after harvesting its central third for reconstruction of the anterior cruciate ligament, and examine the association between the morphologic changes and the occurrence of anterior knee pain of the patients. Methods: Thirty-one patients who had undergone an anterior cruciate ligament reconstruction using central-third bone-patellar tendon-bone autograft with a closure of the patellar tendon defect were included in this study. An ultrasonographic and Power Doppler examination was performed at a mean follow-up of 10 years. Results: Ultrasonography of the harvested patellar tendon showed intratendinous calcification in 9 patients, hypoechoic lesion in 20 patients, hyperechoic lesion in one patient, and peritendinous changes in one patient. No abnormality was visible in the contralateral (normal) patellar tendons of the 31 patients. The harvested patellar tendon was significantly thicker than the contralateral patellar tendon both at the proximal third (p=0.017) and at the distal third (p=0.020) of the tendon. Patellar osteophytes were more common in patients with anterior knee pain than without it (p=0.05). Conclusions: Sonographic morphologic changes of the patellar tendon were common 10 years after the harvesting procedure. Also, the harvested patellar tendon was significantly thicker than the normal patellar tendon

Introduction: Duplex ultrasound has recently been used to demonstrate inflammatory hyperaemia in arteries supplying inflamed joints in RA, bursitis, and tendonitis. The technique has yet to be applied to examine blood flow in lumbar arteries in LBP patients, though we have previously shown its feasibility in healthy subjects. Our aim was to determine if there are differences in the flow characteristics of lumbar arteries in patients with LBP that may be reflective of pathology.

Materials and Methods: Sixty four patients with LBP (21–82 years) and 30 volunteers with no history of LBP (19–82 years) were studied. Sacral and lumbar arteries at L5 to L1 were identified and hemodynamic data was obtained using Duplex ultrasound. Angle corrected measurements of blood flow peak systolic velocity (PSV) were obtained at all lumbar levels and the aorta.

Results: Mean lumbar artery PSV was normalized with mean aorta PSV for patient and control groups. Reference range (mean ± 1.96SD) for normal lumbar artery PSV was defined from the control data and the proportion of patients with abnormally high PSV determined.

Discussion: Blood flow velocity in lumbar arteries of LBP patients is significantly higher compared with asymptomatic controls (p< 0.01). Approximately 40% of the LBP group have abnormally high lumbar artery flow velocity and the proportion of abnormal values increases at lower levels. Abnormally high velocity flow suggests the presence of an inflammatory component in the lumbar spinal structures. This technique has important applications in improving diagnostic specificity and assessing outcome of treatment in patients with LBP.

Background. Post-operative deep venous thrombosis (DVT) and subsequent pulmonary embolism (PE) remain a serious complication after total joint replacement. Although with modern chemical and mechanical prophylaxis and rapid rehabilitation the rate of symptomatic DVT and PE has reduced, isolation of pre-operative DVT, especially in patients with prior history of DVT remains a challenge. The aim of this study was to assess the utility of pre-operative dopplers as a tool to screen and reduce DVT/PE rate in patients undergoing total joint replacement. Methods. Between January 2014 and December 2014, 211 elective primary hip and knee arthroplasty were identified from our prospective institutional database as two consecutive cohorts (115 cases had pre-operative dopplers and 96 did not). All cases were performed by two adult reconstruction specialists. All primary total hip arthroplasties (THA) were non-cemented and all primary total knee arthroplasties (TKA) were cemented with similar implant and technique. In the first cohort, all cases underwent routine pre-operative doppler screening and in the control cohort, only patients with prior history of DVT or PE underwent pre-operative dopplers. All patients with clinical symptoms of calf pain underwent post-operative dopplers. Patients were followed for a minimum of 3 month post-operatively. All emergency room (ER) visits for role out DVT were identified. No patient was lost to follow. Results. In the cohort with pre-operative dopplers, none of the pre-operative dopplers were positive for DVT, including three patients that had a history of prior DVT. 34 patients in this group (29%) underwent post-operative dopplers, either during the hospital stay or in the ER within 3 month after index surgery. Only one patient (no prior history of DVT) developed symptomatic DVT/PE (0.8%) after total knee arthroplasty. In the control cohort, 3 of which (3%) had symptomatic DVT, one of which had PE (1%) during hospital stay, all after total knee arthroplasty. There was no statistical difference for rate of symptomatic DVT/PE between the two groups (p=0.3). There was no correlation between DVT and age, gender or BMI. Discussion and Conclusions. Utilization of routine pre-operative dopplers for all patients did not lower the rate of symptomatic DVT/PE and are not helpful in early detection and prevention in asymptomatic patients prior to routine total joint replacement. Pre-operative dopplers should be used in selected patients with high risk of DVT

Background. Post-operative deep venous thrombosis (DVT) and subsequent pulmonary embolism (PE) remain a serious complication after total joint replacement. Although with modern chemical and mechanical prophylaxis and rapid rehabilitation the rate of symptomatic DVT and PE has reduced, isolation of pre-operative DVT, specially in patients with prior history of DVT remains a challenge. The aim of this study was to assess the use of pre-operative dopplers as a tool to detect and identify prior DVT in patients undergoing total joint replacement. Methods. Between January 2014 and December 2014, 211 elective primary and revision hip and knee arthroplasty were identified from our prospective institutional database. All cases were performed by two adult reconstruction specialists. All primary total hip arthroplasties (THA) were non-cemented and all primary total knee arthroplasties (TKA) were cemented with similar implant and technique. Prior to July 2014, only patients with prior history of DVT or PE underwent pre-operative dopplers. From July 2014, all cases underwent routine pre-operative doppler screening. All patients with clinical symptoms of calf pain underwent post-operative dopplers. Patients were followed for a minimum of 3 month post-operatively. All emergency room (ER) visits for role out DVT were identified. No patient was lost to follow. Results. 115 patients patient underwent pre-operative dopplers. Three patients had a history of prior popliteal DVT, none of which had post-operative DVT or PE. In the remaining 112 patients, none of the pre-operative dopplers were positive for DVT. 34 patients in this group (29%) underwent post-operative dopplers, either during the hospital stay or in the ER within 3 month after index surgery. Only one patient developed symptomatic PE (0.8%) after total knee arthroplasty. 96 patients did not have pre-operative dopplers, 3 of which (3%) had symptomatic DVT and PE during hospital stay, all after total knee arthroplasty. There was no statistical difference for rate of symptomatic DVT/PE between the two groups (p=0.3). There was no correlation between DVT and obesity, age, or revision versus primary cases. Discussion and Conclusions. Routine pre-operative dopplers do not significantly lower rate of symptomatic DVT/PE and are not helpful in early detection and prevention in asymptomatic patients prior to routine total joint replacement

Abstract. Introduction. Surgery in patients with high body mass index (BMI) is more technically challenging and associated with increased complications post-operatively. Inferior clinical and functional mid-term results for high BMI patients undergoing high tibial osteotomy (HTO) relative to normal weight patients have been reported. This study discusses the clinical, radiological and functional outcomes of HTO surgery in patients with a high BMI. Method. This is a retrospective study on patients undergoing HTO surgery using the Tomofix anatomical MHT plate between 2017 and 2022, with follow-up period of up to 5 years. The cohort was divided: non-obese (BMI <30 kg/m2) and obese (BMI>30 kg/m2). Pre and post operative functional scores were collected: Oxford Knee Score (OKS), EuroQol-5D and Tegner. Complications, plate survivorship and Mikulicz point recorded. Results. 32 HTO procedures; 19 patients BMI <30 (average 27.0) and 14 patients BMI >30 (average 36.1). In BMI<30 cohort, one readmission for investigation of venous thromboembolism, doppler negative; two complications: hinge fracture and stitch abscess. The five year survivorship of the plate was 100%. In BMI>30 cohort, one readmission for pulmonary embolism; one complication: hinge fracture. The 5 year survivorship of the plate was 93%, 1 conversion to unicompartmental knee replacement. The average OKS improvement was 17 and 18 for BMI <30 and >30 respectively. Mikulicz point change was identical. Conclusion. The Tomofix anatomical MHT plate achieves good outcomes and minimal complications irrespective of BMI. Reduced plate survivorship, thus earlier conversion may be required in the obese, however higher cohort numbers are needed to confirm this

Major orthopaedic fractures are an independent risk factor for the development of venous thromboembolism (VTE), which are significant causes of preventable morbidity and mortality in trauma patients. Despite thromboprophylaxis, patients who sustain a pelvic or acetabular fracture (PA) continue to have high rates of VTE (12% incidence). Thrombelastography (TEG) is a whole-blood, point-of-care test which provides an overview of the clotting process. Maximal amplitude (MA), from TEG analysis, is the measure of clot strength and values ≥65mm have been used to quantify hypercoagulability and increased VTE risk. Therefore, the primary aim was to use serial TEG analysis to quantify the duration of hypercoagulability, following surgically treated PA fractures. This is a single centre, prospective cohort study of adult patients 18 years or older with surgically treated PA fractures. Consecutive patients were enrolled from a Level I trauma centre and blood draws were taken over a 3-month follow-up period for serial TEG analysis. Hypercoagulability was defined as MA ≥65mm. Exclusion criteria: bleeding disorders, active malignancy, current therapeutic anticoagulation, burns (>20% of body surface) and currently, or expecting to become pregnant within study timeframe. Serial TEG analysis was performed using a TEG6s hemostasis analyzer (Haemonetics Corp.) upon admission, pre-operatively, on post-operative day (POD) 1, 3, 5, 7 (or until discharged from hospital, whichever comes sooner), then in follow-up at 2-, 4-, 6-weeks and 3-months post-operatively. Patients received standardized thromboprophylaxis with low molecular weight heparin for 28 days post-operatively. VTE was defined as symptomatic DVT or PE, or asymptomatic proximal DVT, and all participants underwent a screening post-operative lower extremity Doppler ultrasound on POD3. Descriptive statistics were used to determine the association between VTE events and MA values. For the primary outcome measure, the difference between the MA threshold value (≥65mm) and serial MA measures, were compared using one-sided t-tests (α=0.05). Twenty-eight patients (eight females, 29%) with a mean age of 48±18 years were included. Acetabular fractures were sustained by 13 patients (46%), pelvic fractures by 14 patients (50%), and one patient sustained both. On POD1, seven patients (25%) were hypercoagulable, with 21 patients (78%) being hypercoagulable by POD3, and 17 patients (85%) by POD5. The highest average MA values (71.7±3.9mm) occurred on POD7, where eight patients (89%) were hypercoagulable. At 2-weeks post-operatively, 16 patients (94%) were hypercoagulable, and at four weeks, when thromboprophylaxis was discontinued, six patients (40%) remained hypercoagulable. Hypercoagulability persisted for five patients (25%) at 6-weeks and for two patients (10%) by three months. There were six objectively diagnosed VTE events (21.4%), five were symptomatic, with a mean MA value of 69.3mm±4.3mm at the time of diagnosis. Of the VTE events, four occurred in participants with acetabular fractures (three male, 75%) and two in those with pelvic fractures (both males). At 4-weeks post-operatively, when thromboprophylaxis is discontinued, 40% of patients remained hypercoagulable and likely at increased risk for VTE. At 3-months post-operatively, 10% of the cohort continued to be hypercoagulable. Serial TEG analysis warrants further study to help predict VTE risk and to inform clinical recommendations following PA fractures

Surgical management for acute or impending pathologic fractures in metastatic bone disease (MBD) places patients at high-risk for post-operative venous thromboembolism (VTE). Due to the combination of malignancy, systemic cancer treatment, and surgical treatment, VTE-risk is increased 7-fold in patients with MBD compared to non-cancer patients undergoing the same procedure. The extent and duration of post-operative hypercoagulability in patients with MBD remains unknown and thromboprophylaxis guidelines were developed for non-cancer patients, limiting their applicability to address the elevated VTE-risk in cancer patients. Thrombelastography (TEG) analysis is a point-of-care test that measures clot formation, stabilization, and lysis in whole blood samples. The TEG parameter, maximal amplitude (MA), indicates clot strength and the threshold of ≥65 mm has been used to define hypercoagulability and predict VTE events in non-cancer patients requiring orthopaedic surgery. Therefore, this study aims to quantify the extent and duration of post-operative hypercoagulability in patients with MBD using serial TEG analysis. Consecutive adults (≥18 years) with MBD who required orthopaedic surgery for acute or impending pathologic fractures were enrolled into this single-centre, prospective cohort study. Serial TEG analysis was performed onsite using a TEG®6s haemostasis analyzer (Haemonetics Corporation, Boston, MA) on whole blood samples collected at seven timepoints: pre-operatively; on post-operative day (POD) 1, 3, and 5; and at 2-, 6-, and 12-weeks post-operatively. Hypercoagulability was defined as MA ≥65 mm. Participants received standardized thromboprophylaxis for four weeks and patient-reported compliance with thromboprophylaxis was recorded. VTE was defined as symptomatic DVT or PE, or asymptomatic proximal DVT, and all participants underwent a screening post-operative lower extremity Doppler ultrasound on POD3. Descriptive statistics were performed and difference between pre-operative MA values of participants with VTE versus no VTE was evaluated using Student's t-test (p≤0.05). Twenty-one participants (10 female; 47.6%) with a mean age of 70 ± 12 years were enrolled. Nine different primary cancers were identified amongst participants, with breast (23.8%), colorectal (19.0%), and lung cancer (14.3%) most frequently reported. Most participants (57.1%) were hypercoagulable pre-operatively, and nearly half remained hypercoagulable at 6- and 12-weeks post-operatively (47.1 and 46.7%, respectively). VTE occurred in 5 patients (23.8%) and mean MA was 68.1 ± 4.6 mm at the time of diagnosis. Mean pre-operative MA values were significantly higher (p=0.02) in patients who experienced VTE (68.9 ± 3.5 mm) compared to those who did not (62.7 ± 6.5 mm). VTE incidence was highest in the first week post-operatively, during which time four VTE events (80%) occurred. The proportion of patients in a hypercoagulable state increased at three consecutive timepoints, beginning on POD3 (85.0%), increasing on POD5 (87.5%), and peaking at 2-weeks post-operatively (88.9%). Current thromboprophylaxis guidelines do not consider cancer-associated risk factors that contribute to increased VTE incidence and prescription duration may be inadequate to address prolonged post-operative hypercoagulability in patients with MBD. The high rate of VTE events observed and sustained hypercoagulable state indicate that thromboprophylaxis may be prematurely terminated while patients remain at high risk for VTE. Therefore, extending thromboprophylaxis duration beyond 4-weeks post-operatively in patients with MBD warrants further investigation

Purpose of the study: Thromboembolism is a serious complication after hip surgery. The residual rate of venous thrombosis has varied according to the type of screening used with rates reported from 3.54% to 54.2% without prophylaxis. These discordant figures led us to conduct a prospective study devoted to thromboembolic complications. Material and methods: This prospective study was conducted from April 1995 to April 1996 in 61 consecutive patients who underwent total hip arthroplasty under general anesthesia. Duplex Doppler was performed systematically on day 8 to 10 to search for thromboembolic complications. Results of this study were compared with those of a study we conducted in 2960 total hip arthroplasties implanted from 1950 to 1999 where search for thromboembolic complications was guided by the clinical presentation. Results: Clinical screening for thromboembolic complications in the series of 2960 total hip arthroplasties revealed a rate of 3.54% [pulmonary embolism (n=46), phlebitis (n=95), heparin induced thrombopenia (n=14)]; the rate of anticoagulant accidents was 2.5%. Associating these anticoagulant accidents with the cases of heparin induced thrombopenia, the rate of these complications was 2.97%, almost the same as that of thromboembolic complications. Duplex Doppler screening on day 8–10 detected venous thrombosis in 36.8% of patients. Discussion: Thromboembolic complications with clinically detected phlebitis confirmed by duplex Doppler were observed in 3.54% of our series of 2960 operated patients, but systematic screening with duplex Doppler found a ten-fold higher rate, 36.8%. Should duplex Doppler be performed systematically in the postoperative period? What would be the cost, and the cost-effectiveness? It is known that when phlebitis is detected, anticoagulant treatment must be continued for at least three months postoperatively. In addition, the cases of phlebitis detected by duplex Doppler are generally distal, with no clinical expression; so what would be the benefit for these patients of long-term treatment? Considering the expenditures involved in 1000 total hip arthroplasties treated preventively with low-molecular-weight heparin, the cost of systematic duplex Doppler screening would lead to a supplementary cost of 456000 euros, without counting the cost of treatment for complications due to the anticoagulant treatment. Conclusion: In our opinion, systematic duplex Doppler screening is not warranted. We believe that clinical screening is a valid procedure, in line with evidence provided by duplex Doppler performed in symptomatic patients. Anticoagulant treatment should be continued for six weeks after the arthroplasy as a preventive measure and should be initiated 12 to 24 hours after the operation. Systematic ultrasound screening is only useful in high-risk patients or when thrombosis prophylaxis cannot be instituted

Measurement of blood flow to the skeleton is technically challenging. The specific problems of measuring blood flow that are particular to bone are:. i) there are 206 separate bones in the skeleton;. ii) each bone has multiple arterial inputs and venous outflows;. iii) each bone is heterogeneous, comprising varying proportions of cortical bone, cancellous bone, and marrow (both haematopoietic and fatty). Because of this heterogeneity of the tissue, it is also important to specify precisely the region of bone that is being measured, and this problem accounts for some of the discrepancies in values of bone blood flow quoted in the literature. From a practical orthopaedic perspective, techniques to measure regional blood flow are normally more informative than measurements of total skeletal blood flow. In experimental studies, the microsphere technique has been used most widely for the quantitative measurement of bone blood flow, and is regarded as the gold standard. Particles of the order of 15 microns in diameter are injected into the ventricle and trapped in the microcirculation during a single passage. The distribution of microspheres in the body is proportional to the distribution of cardiac output, and if a reference arterial blood sample is taken during injection of the microspheres, then blood flow may be calculated. Microspheres are normally labeled with a radioactive tracer or a colored dye, and microsphere number is estimated from assays of the attached label. The microsphere technique is a specific example of indicator fractionation, and clinically indicator fractionation can be applied using imaging techniques such as magnetic resonance imaging (MRI) or positron emission tomography (PET). MRI-based techniques are based on gadolinium contrast agents, and PET uses positron-emitting isotopes such as oxygen-15 labelled water, fluorine-18 ion, or . 18. F-fluorodeoxyglucose. Positron-emitting isotopes are short-lived, and need to be produced daily by a cyclotron, limiting the general utility of the technique. However, dynamic PET measurements with fluorine-18 have been used to assess simultaneously both bone blood flow and bone formation rates. Blood flow can also be estimated from velocity measurements, e.g. electromagnetic flowmetry, laser Doppler, and ultrasound Doppler. Laser Doppler measurements require contact between the probe and the tissue being measured, and have applications in experimental studies of vascular reactivity in bone. Although ultrasound is reflected very effectively from bone surfaces, ultrasound Doppler has been used to image the lumber arteries in patients with degenerative disc disease. Bone, like other tissues in the body, is relatively transparent to light in the near-infra red, but there are specific absorption peaks for deoxy- and oxy-hemoglobin. This is the basis of near infra-red spectroscopy for perfusion measurements. However, because of the complexities of light scattering in tissue, spatial resolution is poor. Measurements in the proximal tibia are quite straightforward, and we are currently using this technique in studies of bone loss in spinal cord injury patients