***TASK*** the task is to summarize an input biomedical literature in six sentences 
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    Input: Abstract Forty patients suffering from a medial femoral neck fracture participated in a prospect i ve , r and omized study . In 20 patients , the femoral component was cemented using a contemporary technique . In the patient group operated on with the bone vacuum technique , the medullary cavity was drained during the insertion of the stem . The proximal draining hole was placed in the intertrochanteric region , along the prolongation of the linea aspera . The distal hole was placed 2 cm below the tip of the femoral component . Embolic phenomena were documented intraoperatively by continuous transesophageal echocardiographic imaging of the right atrium and ventricle . The clinical relevance of the emboli was noted simultaneously by recording hemodynamic and blood gas parameters .  Patients of the control group showed severer and longer-lasting episodes of embolism than patients of the bone vacuum group . Ongoing emboli were first seen during the injection of the cement , and continued during stem insertion . Massive emboli of small particles could be verified in 19 patients ( 95 % ) of the control group and in 1 patient ( 5 % ) of the bone vacuum group ( P < 0.05 ) . During massive emboli , a distinct decrease in the arterial oxygen saturation and the end-expiratory carbon dioxide level was observed . The calculated average pulmonary shunt volume showed an increase after the insertion of the stem using the contemporary technique ( 36.5 % ; P < 0.05 ) . These distinct hemodynamic changes were not observed in the bone vacuum group . This study was able to show a clearly reduced risk of pulmonary emboli using the bone vacuum cementing technique . The presence of pre-existing disease greatly magnified the clinical relevance of fat embolism This prospect i ve r and omized trial compared the efficacy of unipolar versus bipolar hemiarthroplasty in elderly patients ( ≥ 65 years ) with displaced femoral neck fractures in terms of quality of life and functional outcomes . One hundred fifteen patients with a mean age of 82.1 years were enrolled in this study and r and omized to either unipolar or bipolar hemiarthroplasty .  Quality of life and functional outcomes were assessed using the Musculoskeletal Functional Assessment instrument and Short Form-36 health survey .  Seventy-eight patients completed 1 year of followup . There were no differences between the groups in estimated blood loss , length of hospital stay , mortality rate , number of dislocations , postoperative complications , or ambulatory status at 1 year . There also were no significant differences between the two groups at either point in postoperative Short Form-36 or Musculoskeletal Functional Assessment instrument scores . Results of this prospect i ve r and omized study suggest that the bipolar endoprosthesis provides no advantage in the treatment of displaced femoral neck fractures in elderly patients  regarding quality of life and functional outcomes In a prospect i ve trial of 278 patients aged over 65 years , treatment of displaced subcapital fractures was r and omly allocated to closed reduction and internal fixation with a sliding compression screwplate , Moore hemiarthroplasty , or total hip treatment with a Howse semicaptive prosthesis . One year after operation there was little difference between the three groups in mortality ( 25 per cent ) or general complications . The revision rate within the first year was highest for internal fixation ( 25 per cent ) , but many of the replacements also required a further anaesthetic for reduction of a dislocation ( Moore , 11 per cent ; Howse 12.5 per cent ) . Total hip replacement result ed in the least pain and most mobility at 1 year , while hemiarthroplasty was worst in these respects . We conclude that internal fixation and particularly primary total hip replacement should be given serious consideration in the management of the elderly patient with a displaced subcapital fracture We report a r and omised prospect i ve trial of the early results of three types of treatment for displaced intracapsular hip fractures . We used a question naire sent to patients at about six months ( Nottingham Health Profile , NHP ) in addition to clinical assessment s. There was a 67.4 % usable response to the question naire , similar to that in other studies using the NHP . There were more responders from younger patients , those walking independently before injury and those with higher mental test scores  on admission . In the younger group ( 65 to 79 years ) we found a trend for better scores in most NHP indices after the use of a bipolar prosthesis rather than a unipolar prosthesis or internal fixation , particularly for social function , pain and physical mobility . Postal assessment using the NHP gave a satisfactory response rate even in the elderly , and can provide an extra assessment to complement or replace hospital follow-up in some circumstances A prospect i ve clinical trial has been conducted comparing the use of a hydoxyapatite-coated bipolar hemiarthroplasty and an uncemented bipolar prosthesis in the treatment of displaced subcapital fractures of the femur . The trial was conducted over 1 year , 82 patients suffering displaced subcapital fractures of the femur were included . The patients were followed up for 1 year postoperatively . The functional result was significantly superior in the hydroxyapatite-coated group . Characteristic changes were found on radiographs both proximally and distally , indicating that distal stem fixation with proximal stress shielding had occurred We performed a r and omised prospect i ve trial to compare a cemented unipolar prosthesis ( Thompson ) with a cemented bipolar prosthesis ( Monk ) in the treatment of displaced intracapsular fractures of the hip in patients over 80 years of age . Patients with a mental test score of less than 5/13 were excluded but the mortality was still about 30 % at one year in both groups . We therefore feel that subjective criteria such as the level of pain and the return to the preinjury state are of paramount importance . Two years after operation there was no statistical difference between the rate of complications in the two groups . After adjusting for confounding factors such as differences in the level of function before injury between the groups , the degree of return to the preinjury state was significantly greater ( p = 0.04 ) when using the unipolar prosthesis , which is one-quarter of the price of the bipolar . We can not therefore justify the use of an expensive bipolar prosthesis in patients over 80 years of age The Cambridge Cup has been design ed to replace the horseshoe-shaped articular cartilage of the acetabulum and the underlying subchondral bone . It is intended to provide physiological loading with minimal resection of healthy bone . The cup has been used in 50 women with displaced , subcapital fractures of the neck of the femur . In 24 cases , the cup was coated with hydroxyapatite . In 26 , the coating was removed before implantation in order to simulate the effect of long-term resorption . The mean Barthel index and the Charnley-modified Merle d'Aubigné scores recovered to their levels before fracture . We review ed 30 women at two years , 21 were asymptomatic and nine reported minimal pain .  The mean scores deteriorated slightly after five years reflecting the comorbidity of advancing age . Patients with the hydroxyapatite-coated components remained asymptomatic , with no wear or loosening . The uncoated components migrated after four years and three required revision . This trial shows good early results using a novel , hydroxyapatite-coated , physiological acetabular component We performed a prospect i ve , r and omised trial comparing three treatments for displaced intracapsular fractures of the hip in 280 patients aged 65 to 79 years . The mean patient survival was significantly higher in the group undergoing reduction and internal fixation ( 79 months ) compared with that with a cemented Thompson hemiarthroplasty or a cemented Monk bipolar hemiarthroplasty ( 61 months and 68 months , respectively ) . After three years , 32 of 93 patients ( 34.4 % ) who had undergone fixation had local complications , necessitating further intervention in 28 ( 30 % ) . There were no significant differences in the functional outcome in survivors , who were review ed annually to five years . Either reduction and internal fixation or cemented hemiarthroplasty may be offered as alternative treatments for a displaced intracapsular fracture in a mobile and mentally competent patient under the age of 80 years . The choice of procedure by the patient and the surgeon should be determined by the realisation that the use of internal fixation is associated with a 30 % risk of failure requiring further surgery . If this is accepted , however , hemiarthroplasty is avoided , which , in our study has a significantly shorter mean survival time . The use of a bipolar prosthesis has no significant advantage BACKGROUND Hemiarthroplasty and total hip arthroplasty are commonly used to treat displaced intracapsular fractures of the femoral neck , but each has disadvantages and the optimal treatment of these fractures remains controversial . METHODS In the present prospect ively r and omized study , eighty-one patients who had been mobile and lived independently before they had sustained a displaced fracture of the femoral neck were r and omized to receive either a total hip arthroplasty or a hemiarthroplasty .  The mean age of the patients was seventy-five years . Outcome was assessed with use of the Oxford hip score , and final radiographs were assessed . RESULTS After a mean duration of follow-up of three years , the mean walking distance was 1.17 mi ( 1.9 km ) for the hemiarthroplasty group and 2.23 mi ( 3.6 km ) for the total hip arthroplasty group , and the mean Oxford hip score was 22.3 for the hemiarthroplasty group and 18.8 for the total hip arthroplasty group . Patients in the total hip arthroplasty group walked farther ( p=0.039 ) and had a lower ( better ) Oxford hip score ( p=0.033 ) than those in the hemiarthroplasty group . Twenty of thirty-two living patients in the hemiarthroplasty group had radiographic evidence of acetabular erosion at the time of the final follow-up . None of the hips in the hemiarthroplasty group dislocated , whereas three hips in the total hip arthroplasty group dislocated . In the hemiarthroplasty group , two hips were revised to total hip arthroplasty and three additional hips had acetabular erosion severe enough to indicate revision . In the total hip arthroplasty group , one hip was revised because of subsidence of the femoral component . CONCLUSIONS Total hip arthroplasty conferred superior short-term clinical results and fewer complications when compared with hemiarthroplasty in this prospect ively r and omized study of mobile , independent patients who had sustained a displaced fracture of the femoral neck We studied 1162 consecutive total hip replacements ( THR ) to establish the incidence of fatal pulmonary embolism ( PE ) , clinical non-fatal PE and deep-vein thrombosis ( DVT ) in the six months after surgery .  Chemical thromboprophylaxis had not been routinely used . We used a vali date d question naire supplemented by post-mortem records and a review of the clinical notes . Follow-up was 100 % . The death rate from PE was 0.34 % ( 95 % CI 0.09 to 0.88 ) , with one fatal PE after discharge 40 days after operation . The clinical PE rate confirmed by imaging was 1.20 % ( CI 0.65 to 2.02 ) , with 0.7 % of patients readmitted . The venographically-confirmed clinical DVT rate was 1.89 % ( CI 1.11 to 2.76 ) , with 1.13 % readmitted . The total thromboembolic morbidity was 3.4 % ( 95 % CI 2.5 % to 4.7 % ) ; prophylaxis to reduce this would be justifiable if the complications of such prophylaxis did not produce an alternative morbidity . The fatal PE rate after THR without routine chemical prophylaxis was low ; a very large r and omised clinical trial would be required to demonstrate directly whether any prophylactic measure could reduce this . There is a large discrepancy between the high DVT rate reported in clinical trials using universal screening venography and the symptomatic DVT rate shown in this study . We found insufficient evidence to recommend continuing thromboprophylaxis after discharge from hospital BACKGROUND Orthopaedic surgeons vary in their management of displaced intracapsular fractures of the hip in healthy older patients . The aim of this investigation was to determine the functional , clinical , and re source consequences of three different types of surgical treatment . METHODS The study was a multicenter r and omized controlled trial . Reduction and fixation was compared with bipolar hemiarthroplasty with cement and total hip replacement with cement .  Participating surgeons elected to r and omize their patients to be treated with either one of the three types of procedures or with either fixation or bipolar hemiarthroplasty .  Functional outcomes were measured with a hip-rating question naire and the EuroQol health status measure . Clinical outcomes included mortality and complications . The direct health service costs were compared . Participants were followed up for two years . RESULTS Two hundred and seven patients were r and omized to be treated with one of the three operations , and ninety-one were r and omized to be treated with either fixation or bipolar hemiarthroplasty .  There were no differences in the mortality rates among the treatment groups . The rate of secondary surgery was highest in the fixation group ( 39 % compared with 5 % in the group treated with bipolar hemiarthroplasty and 9 % in the group treated with total hip replacement ) . The fix 
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For this comparison , there were no significant differences in any other outcome .
Comparison of unipolar hemiarthroplasty with bipolar hemiarthroplasty ( seven trials , 857 participants ) showed no significant differences between the two types of implant .
REVIEW ERS ' CONCLUSIONS Cementing prostheses in place seems to reduce pain post-operatively and results in better mobility , but because of the under-reporting of outcomes and the small number of patients involved , no definite conclusions can be made .