***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    ***EXAMPLES*** 
    Input: The proximal femoral nail ( PFN ) is a recently introduced intramedullary system , design ed to improve treatment of unstable trochanteric fractures of the hip . In a multicentre prospect i ve clinical study , the intra-operative use , complications and outcome of treatment using the  PFN ( n = 211 ) were compared with those using the gamma nail ( GN ) ( n = 213 ) . The intra-operative blood loss was lower with the PFN ( 220 ml v 287 ml , p = 0.001 ) . Post-operatively , more lateral protrusion of the hip screws of the PFN ( 7.6 % ) was documented , compared with the gamma nail ( 1.6 % , p = 0.02 ) . Most local complications were related to suboptimal reduction of the fracture and /or positioning of the implant . Functional outcome and consolidation were equal for both implants . Generally , the results of treatment of unstable trochanteric fractures were comparable for the PFN and GN . The pitfalls and complications were similar , and mainly surgeon- or fracture-related , rather than implant-related PURPOSE Asian patients with osteoporosis suffer from an increased incidence of hip fracture and a potentially increased risk of fixation failure due to anatomical differences compared to Caucasians . To cope with these differences , an Asian size- and geometry-adapted Proximal Femoral Nail Antirotation ( PFNA-II ) was developed . The objective of this prospect i ve multicenter study was to assess the risk of fracture fixation complications ( FFCs ) , the occurrence of mismatch and the quality of life status of patients treated with the PFNA-II .  PATIENTS AND METHODS 176 Japanese patients with an isolated , unstable , closed trochanteric fracture were treated with the PFNA-II .  Patients were prospect ively screened for anticipated complications and classified accordingly ; complications were central ly review ed by a complication review board to avoid bias by the treating surgeon , and categorized using a st and ardized reporting system . Outcome measurements included the occurrence and evaluation of FFCs , the radiological assessment of mismatch and quality of life measured with the EQ-5D score . RESULTS 3 Intraoperative and 15 postoperative complications were found in 16/176 patients . The risk of sustaining any intraoperative or postoperative FFC was 1.7 % ( 3/176 ; 95 % CI : 0.35 - 4.9 ) and 8 % ( 14/176 ; 95 % CI : 4.4 - 13 ) , respectively . The most likely cause for FFCs was the " bone/fracture " factor ( 9/14 patients ) . Radiologically detectable contact of the implant with the inner cortex ( " mismatch " ) was reported for 17/173 patients ( 10 % ) . CONCLUSIONS The reported complication risks and mismatches are reasonable for this patient cohort . The geometry- and size-adapted PFNA-II is relatively safe but requires st and ardized assessment in a larger target cohort Medical instructions for partial weight-bearing after lower limb surgery and fractures are commonly given . The techniques for instruction are mainly verbal cues . Our aim was to evaluate the efficiency of a new biofeedback device  compared with traditional intervention for gait rehabilitation .  After orthopedic surgery , 33 patients , r and omly divided into a study group ( n = 15 ) and a control group ( n = 18 ) , completed 10 days of a rehabilitation protocol . A significant difference ( P<.05 ) was found between the groups . Study subjects were able to follow weight-bearing instructions better . We suggest that gait rehabilitation is more efficient when biofeedback is used to instruct patients regarding partial weight-bearing The aim of this study was to compare two proximal femur nails with regard to the complication rate and midterm clinical outcome : the InterTAN nail ( ITN ) versus the third generation gamma nail ( GN ) .  78 patients older than 60 years with an unstable intertrochanteric femoral fracture ( AO/OTA 31 A2/A3 ) were r and omised over a 20 month period into either ITN ( n = 39 ) or GN ( n = 39 ) . The outcomes of interest were the perioperative implant-related complications and the functional status ( Harris Hip Score ) at 6 months postoperatively . In 14 of the ITN and in two of the GN procedures the surgeons rated the implant as cumbersome ( p = 0.002 ) . Functional outcome and complication rate did not differ between both groups . The mechanical failure correlated with the positioning of the lag screw independent on the used implant . The surgeon 's technique ( closed reduction , positioning of lag screw ) and not implant configuration , is of crucial importance in achieving successful outcome BACKGROUND Femoral intramedullary nailing is currently one of the most frequent surgical treatments for extracapsular hip-fracture fixation . Cutting-out of the lag screw is the main complication of this technique , but only few studies have approached the cutting-out focussed on femoral nailing . The aim of this study was to confirm in patients treated with intramedullary nailing  not only with regard to previous reports about the association of cutting-out with technical factors , but also with regard to clinical factors not previously studied . METHODS Case-control study of all patients sustaining a cut-out of the femoral nail was carried out and a control sample was r and omly selected among all extracapsular hip-fracture patients during the study period ( 2005 - 2008 ) . All clinical and technical variables were collected from medical records . Orthopaedic Trauma Association ( AO/OTA ) fracture classification , Singh Osteoporosis Index of the contralateral hip and the American Society of Anaesthesiology ( ASA ) criteria for preoperative clinical status were used . Statistical assessment included bivariant analysis and multivariant logistic regression analysis . RESULTS A total of 916 hip-fracture cases were treated in the study period : 33 of them ( 3.6 % ) were identified as suffering cutting-out , and 315 controls fulfilling inclusion criteria were also recruited . No statistical differences were found in age , sex or other socio-demographic variables between the two groups . Bivariant analysis showed significant differences between groups in technical variables ( tip-apex distance , suboptimal placement of lag screw , fracture diastasis , inadequate fixation quality and distal static locking ) and in clinical variables ( osteoporosis severity , right hip affected , better previous ability for walking and better preoperative ASA status ) . Multivariant logistic regression analysis showed significant association only for tip-apex distance and inadequate fixation quality . Differences in distal static locking were close to statistical significance . CONCLUSIONS The strongest predictor of cutting-out in femoral nailing is tip-apex distance . This study suggests that distal static locking and other clinical conditions play an important role in this fixation failure ABSTRACT Purpose : The purpose was to study the performance of exp and able proximal femoral nails ( EPFNs ) for the treatment of unstable intertrochanteric fractures in elderly patients . Patients and methods : Eighty-four patients were treated with a newly design ed EPFN and followed up for one year . Results : The mean operating time was 50.1 ± 3.2 min and the mean blood loss was 112.3 ± 5.3 ml . Patients were treated with EPFNs of 220 mm ( n = 24 ) , 240 mm ( n = 59 ) , and 340 mm ( n = 1 ) length . At six months postoperatively , the Harris Hip Score was 74.5 ± 5.3 . At the end of follow up , 75 % of patients completely recovered their preoperative function and resumed their normal activities . Seven patients died within one year postoperatively . During the operation , one patient experienced proximal femoral diaphyseal slight crack fracture . This crack fracture was treated by using a long EPFN ( 340 mm ) . Two patient developed screw cut-outs , which were solved by reoperation . And one developed deep infection resolved favorably by the appropriate antibiotic treatment . Implant failure , deep venous thrombosis , fat embolism , secondary fracture , and nonunion were not encountered . Conclusions : In conclusion , the results of the EPFNs were satisfactory in most elderly patients with unstable intertrochanteric fracture . However , during the inflation period , the pressure on the nail must be monitored carefully in order to prevent a crack fracture Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more BACKGROUND Unstable intertrochanteric fractures present a challenge to orthopaedic surgeons , with varied geometry of the fractures and a wide choice of implants and techniques . The patients are usually osteoporotic , with multiple co-morbidities and poor tolerance for complications and re-operations . Lateral wall reconstruction and stability of the trochanteric fragments are considered important in providing a better outcome of these difficult injuries . We present a technique of lateral wall and trochanteric reconstruction using Cerclage wires and lag screws in the greater trochanter in addition to intramedullary nailing , and the radiological and functional outcome of this technique of augmentation . MATERIAL S AND METHODS This prospect i ve study includes 154 patients from 2010 to 2015 presenting to the institute with an unstable intertrochanteric fracture . They were sequentially operated with intramedullary nailing ( IMN ) and augmentation with cerclage wire and /or Anteroposterior screw in greater trochanter , and 77 patients with IMN  only . Operating time and need for blood transfusion post-surgery were documented . Patients were followed up for minimum of 12 months and radiological union time , complications and functional outcome using Harris Hip Score were noted at 1 year . Statistical analysis was performed to compare the results in both groups RESULTS : The mean union was 3.6 months in group A and 4.1 months in group B , with no statistically significant difference . The operating time needed for augmentation was 10 minutes more than IMN only . Blood transfusion was not required in any case . The incidence of complications like screw cut out , back out and non-union was lower in augmented group , and good functional outcome was greater in the augmented group which was statistically significant . The reoperation rate was lower in augmented group . CONCLUSIONS This new technique of augmentation of fixation of intramedullary nail in unstable trochanteric fractures using cerclage wires and lag screws for lateral wall reconstruction is useful in reducing complications of the procedure and provides good radiological and functional outcome . It requires little additional operating time with minimal blood loss and soft tissue injury Partial weight bearing is a generally accepted principle of rehabilitation following trauma or reconstructive surgery of the lower extremity . Individual dynamic loads during partial weight bearing to a given load level of 200 N were compared in 23 patients who had sustained a fracture of the lower extremity and 11 healthy volunteers using dynamic sole pressure measurements . Excessive dynamic loading compared with the statically pre-tested 200 N level was observed in all groups . Maximum force levels were up to 690 N in young patients and up to 580 N elderly patients beyond the prescribed static load . None of the healthy volunteers was able to keep within the given load of 200 N. The set load level was exceeded by at least 38 N ( 119 % ) in the elderly patient group . In comparison , elderly patients showed statistically significantly higher maximum forces than young patients during the first two test days ( p=0.007 and 0.013 ) . On the 3rd test day the maximum ground contact forces were on average 71 N higher than in the young patients group . Analysis of the force time integrals ( impulses transferred to the ground ) displayed higher values in the older again than in young patients . The differences were statistically significant during the first two test days ( p=0.006 and 0.037 ) . This study implies that the conventional concept of postoperative partial weight bearing starting from 200 N and a stepwise increase of the load level until full weight bearing is not valid during clinical practice Objectives : To compare the results between a new intramedullary Gamma nail and a compression hip screw in the treatment of trochanteric fractures . Design : Prospect i ve r and omized . Setting : Level 1 trauma center . Patients : Two hundred ten consecutive patients older than 65 years with trochanteric femoral fractures . Interventions : Treatment with a compression hip screw or a new design of the Trochanteric Gamma nail ( 180 mm in length with a mediolateral angle of 4 ° and available only with a proximal diameter of 17 mm and distal diameter of 11 mm ) . Main Outcome Measurements : Operative and fluoroscopy times , blood loss , functional outcome , complication rate , and failure of fixation . Results : The Trochanteric Gamma nail  was used in 104 patients and the compression hip screw in 106 . The 2 groups were similar in terms of their preoperative data , with a median follow-up of 13.6 months ( range 12 - 30 ) . The results show no difference in operating time ( P = 0.21 ) , but the Trochanteric Gamma nail group had a significantly shorter fluoroscopy time ( P = 0.006 ) , and the number of patients transfused and the mean of units of blood transfused were significantly less in the Trochanteric Gamma nail group ( P = 0.013 , 0.046 , respectively ) . Mortality within 12 months was similar in both groups ( P = 0.83 ) . All fractures 
    Output:
    
With evidence available to date , there is no clear agreement on the postoperative rehabilitation protocol following fixation of an unstable trochanteric fracture by cephalomedullary nail in the elderly