***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 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Thirty – two patients scheduled for total knee arthroplasty were r and omized to receive an identical epidural blockade initiated 30 min before surgical incision ( N = 16 ) , or at closure of the surgical wound ( N=16 ) . Before induction of general anaesthesia the epidural catheter was tested with bupivacaine 7.5 mg ml‐1 , 2 ml . General anaesthesia was induced with thiopentone , pancuronium or atracurium , and fentanyl 0.1–0.3 mg , and maintained with N2O/O2 and enflurane . The epidural regimen consisted of a bolus of 16 ml of bupivacaine 7.5 mg ml‐1 plus morphine 2 mg , and continuous infusion of bupivacaine 1.25 mg ml‐1 plus morphine 0.05 mg – ml‐1 , 4 mlh‐1 for the first 24 h , and bupivacaine 0.625 mg ml‐1 plus morphine 0.05 mg·ml‐1 , 4 ml . h‐1 , for the next 24 h after operation . Additional morphine 2.5–5 mg was administered i.v . or i.m . for the first 24 h postoperatively , and ketobemidone or morphine 5–10 mg orally or rectally from 24 h to 7 d postoperatively , on request . Paracetamol 1000 mg every 8 h was administered from 48 h to 7 days postoperatively . No significant differences were observed in request for additional opioids , or in pain scores at rest or during mobilisation of the operated limb , during or after cessation of the epidural regimen . These results do not suggest timing of analgesia with a conventional , continuous epidural regimen to be of major clinical importance in patients undergoing total knee arthroplasty This prospect i ve , controlled study compared cold compressive dressings with wool and crepe in the postoperative management of patients undergoing total knee replacement ( TKR ) . Forty TKR patients were assessed for  blood loss , pain , swelling , and range of motion . Patients in the cold compression group had less blood loss through suction drainage ( 982 mL versus 768 mL ) . A higher proportion of patients in the treatment group did not require blood transfusion postoperatively . Mean opiate requirements were lower in the cold compression group ( 0.57 versus 0.71 mg/kg/48 hours ) . The cold compression device appeared to reduce blood loss and pain following TKR BACKGROUND We studied whether a small dose of clonidine added to a ropivacaine-fentanyl mixture improves epidural analgesia without provoking side effects typically related to larger amounts of epidural clonidine . METHODS In this r and omized , double-blinded study , patients ( < or = 85 yr , ASA I-III ) underwent total knee arthroplasty ( TKA ) performed under spinal anaesthesia . After the operation , patients received an epidural infusion consisting of ropivacaine 2 mg ml(-1 ) and fentanyl 5 microg ml(-1 ) either without ( Group RF , n=33 ) or with clonidine 2 microg ml(-1 ) ( Group RFC , n=36 ) . The infusion rate was adjusted within the range 3 - 7 ml h(-1 ) . RESULTS Average rate of infusion was slightly smaller in Group RFC than in Group RF ( mean ( sd ) 4.7 ( 0.72 ) vs 5.2 ( 0.8 ) ml h(-1 ) , P=0.004 ) . Compared with the RF group , patients in the RFC group required significantly less rescue pain medication , that is i.m . oxycodone ( median ( 25th , 75th percentile ) 0 ( 0 , 7 ) vs 7 ( 0 , 12 ) mg , P=0.027 ) . Arterial pressure and heart rate were slightly lower in Group RFC throughout the study period ( mean difference between the groups 5 mm Hg ( P<0.002 ) and 3 min(-1 ) ( P=0.12 ) , respectively ) . The groups did not differ statistically with respect to nausea , motor block , and sedation . CONCLUSIONS The small amount of clonidine added to the low-dose ropivacaine-fentanyl mixture reduced the need for opioid rescue pain medication after TKA . Clonidine slightly decreased arterial pressure and heart rate without jeopardizing haemodynamics . Otherwise , the side effect profiles were comparable in both groups 68 consecutive patients who had primary knee arthroplasties because of arthrosis were r and omized to postoperative continuous passive motion ( CPM ) or active physical therapy ( APT ) . Rehabilitation in both groups was initiated on the first postoperative day . The CPM group sustained less postoperative knee swelling with more rapid initial improvement in knee flexion than did the APT group , but there were no differences between the groups in knee flexion at discharge . Postoperative pain rating and hospitalization times were similar in the two groups During a two-year period , eighty-nine patients who were scheduled to have a total knee arthroplasty for the treatment of degenerative osteoarthrosis were r and omly assigned to one of two groups : resurfacing of the patella or retention of the patella . All patients received the same  posterior cruciate-sparing prosthesis  , and all operations were performed by , or under the direct supervision of , one of us . Three patients died in the early postoperative period . The remaining eighty-six patients ( 118 knees ; fifty-eight that had had resurfacing of the patella and sixty that had not ) formed the study group . They were followed for a mean of thirty months ( range , twenty-four to forty-four months ) . Evaluation was performed with use of the clinical scoring system of The Knee Society , a patient-satisfaction question naire , specific questions regarding patellofemoral symptoms and function , and radiographs . All clinical evaluations were performed by the same research nurse , without the involvement of a physician , in a blinded manner ( neither the nurse nor the patient had knowledge of whether the patella had been resurfaced ) . Preoperatively , the mean Knee Society score , on a scale ranging from 0 to 200 points , was 89.7 points ( range , 33 to 132 points ) ; postoperatively , this score improved to a mean of 172.7 points ( range , 98 to 200 points ) . With the numbers available for study , we could detect no significant difference between the knees that had had patellar resurfacing and those that had not with regard to the over-all score ( p = 0.63 ) , the subscore for pain ( p = 0.56 ) , or the subscore for function ( p = 0.77 ) . We also could detect no difference between the treatment groups , with the numbers available , with regard to patient satisfaction or the responses to questions involving the function of the patellofemoral joint , including the ability to exit from an automobile , to rise from a chair , and to climb stairs .  Thirty-two patients had bilateral total knee replacement with resurfacing of the patella in one knee and retention of the patella in the other . These patients expressed no clear preference for either knee . Eight ( 13 per cent ) of the sixty knees that had not had resurfacing were painful anteriorly compared with four ( 7 per cent ) of the fifty-eight that had ; this was not a significant difference ( p = 0.38 ) , with the numbers available . The anterior pain that was noted postoperatively was predominantly of new onset ; it had not been observed preoperatively in three of the four knees that had had resurfacing or in four of the eight that had not . No additional treatment options were offered to the patients who had anterior pain in the knee after resurfacing . However , six ( 10 per cent ) of the sixty knees that had not had resurfacing had it subsequently , because of anterior pain in the knee , after the twelfth postoperative month ( range , fifteen to thirty-nine months ) . The pain decreased in four of these knees . Thus , total knee arthroplasty with retention of the patella yielded clinical results that were comparable with those after total knee arthroplasty with patellar resurfacing , but it was associated with a 10 per cent prevalence of the need for subsequent resurfacing . The prevalence of anterior pain after total knee arthroplasty was not influenced by whether or not the patella had been resurfaced . The postoperative clinical scores , the postoperative development of anterior pain , and the need for subsequent resurfacing were not predicted by the presence of preoperative anterior pain , obesity , or the grade of chondromalacia observed intraoperatively . Because of the short duration of follow-up , these results should be considered preliminary . Additional follow-up is planned Sixty patients undergoing total knee replacement were r and omized to receive either a cold compression dressing ( Cryo/Cuff , Aircast , UK ) or a modified Robert Jones b and age immediately after surgery . The cold compression dressing was used for a minimum of 6 h per day throughout the hospital stay , and the modified Robert Jones b and age remained in place for 48 h from the time of operation . The 2 groups of patients were compared during their hospital stay for blood loss , range of movement , pain scores and need for analgesia . No difference was found between the 2 groups except for less blood loss in the surgical drains in the cold compression group ( P<0.05 ) . Postoperative complications were seen in both groups , but no complication was associated with either the cold compression dressing or the modified Robert Jones b and age . RésuméEtude r and omisée de 60 patients qui , immédiatement après une arthroplastie totale du genou ont eu soit un pansement compressif froid de type “ Cryocuff ” soit un pansement compressif de type Robert Jones . Le pansement froid a été utilisé 6 heures par jour pendant la durée de l'hospitalisation t and is que le pansement compressif de type Robert Jones a été laisse en place pendant 48 heures après l'opération . Aucune différence statistiquement significative n'a pu être mise en évidence entre les deux groupes , à l'exception des pertes sanguines dans le drainage , moins importantes dans le premier groupe de patients . Nous avons eu des complications post opératoires dans les deux groupes mais aucune corrélation n'a pu être établie entre ces complications et le type de b and age appliqué Background : Patient‐controlled epidural analgesia ( PCEA ) has been found to be an effective method for pain relief during labour and after surgery . The goal of this study was to compare the efficacy of bupivacaine – fentanyl PCEA and continuous epidural infusion with the same mixture for treatment of pain after total knee arthroplasty We report the results of a prospect i ve r and omised trial which assessed the role of the posterior cruciate ligament ( PCL ) following  total knee replacement  ( Genesis I ; Smith and Nephew , Memphis , Tennessee ) . Over a four-year period , 211 patients underwent total knee replacement by the senior author ( TJW ) . They were r and omised at surgery to have the PCL either retained , excised or substituted with a posterior stabilised insert . If it was not possible to retain the ligament due to soft-tissue imbalance , it was released from its tibial insertion until suitable tension was obtained . This created a fourth group , those who were intended preoperatively to have the ligament retained , but in whom it was partially released as a result of findings at the time of surgery . All patients were evaluated using the Knee Society rating system ( adapted from Insall ) . A total of 188 patients ( 212 knees ) was available for follow-up at a mean of 3.5 years after surgery . Preoperatively , there was a varus deformity in 191 knees ( 90 % ) and a valgus deformity in 21 ( 10 % ) . There were no statistical differences in the knee or function scores or the range of movement between the excised , retained and substituted groups . There were , however , significantly worse knee and function scores in the group in whom the PCL was released ( p = 0.002 ) Purpose We previously established that a 5 mg·kg−1 intraoperative dose can reduce the nausea/vomiting associated with tramadol patient-controlled analgesia ( PCA ) . This study was conducted to identify the most appropriate initial dose to improve the quality of tramadol PCA . Methods During general anesthesia , 60 patients undergoing knee arthroplasty were r and omly allocated to receive 1.25 mg·kg−1 ( Group I ) , 2.5 mg·kg−1 ( Group II ) , 3.75 mg·kg−1 ( Group III ) , or 5 mg·kg−1 ( Group IV ) tramadol . The emergence condition was recorded . The titration of additional tramadol 20 mg + metoclopramide 1 mg doses by PCA every five minutes was performed in the postanesthesia care unit ( PACU ) until the visual analogue scale ( VAS ) score was ≤ 3 . An investigator blinded to study group recorded the VAS and side effects every ten minutes . Results In the PACU , significantly more tramadol ( 8.4 ± 3.1vs 4.3 ± 2.1 , 2.5 ± 1.8 , and 0.4 ± 0.3,P < 0.05 ) , and a higher incidence ( 15/15vs 5/15 , 3/15 , and 2/15,P < 0.05 ) of PCA use was observed in Group I compared to Groups II – IV . VAS was significantly higher in Group I than in Groups II – 
    Output:
    
The evidence from this review supports the use of general anaesthesia combined with a femoral nerve block for surgery and postoperative analgesia , or alternatively spinal anaesthesia with local anaesthetic plus spinal morphine .