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Biomedical subjects

G H Westrich

Publications and source records attributed to G H Westrich.

At least 19 recordsLinked to original sources
PubMed2001

[Prevention of thrombosis in hip prosthesis implantation].

Deep venous thrombosis is one of the most common perioperative complications after total hip arthroplasty. Systemic anticoagulation has been the gold standard for prophylaxis of postoperative deep venous thrombosis. There is no doubt that early mobilization and the use of pneumatic compression devices decrease the overall deep venous thrombosis rate. Single postoperative prophylaxis may decrease the overall deep venous thrombosis rate to 15-20% and the proximal deep venous thrombosis rate to approximately 7%. However,the activation of thrombogenesis is mainly an intraoperative event. The position of the extremity during the implantation of the femoral component leads to obstruction of the venous outflow. At the same time, the coagulation cascade is activated and markers of thrombogenesis in the blood are increased. By combining intraoperative (hypotensive epidural anesthesia and intraoperative heparin) and postoperative (pneumatic compression devices and aspirin) prophylaxis of deep venous thrombosis, the total deep venous thrombosis rate is reduced to less than 10% and the proximal deep venous thrombosis rate is reduced to 2%. Patients with increased risk for deep venous thrombosis should receive Coumadin or low-molecular weight heparin. In addition, hypotensive epidural anesthesia reduces the intraoperative blood loss and the need for postoperative blood transfusion.

Anesthesia, Epidural↗
PubMed2001

The effect of preoperative donation of autologous blood on deep-vein thrombosis after total hip arthroplasty.

We have assessed the effect of the donation of autologous blood and the preoperative level of haemoglobin on the prevalence of postoperative thromboembolism in 2043 patients who had a total hip arthroplasty. The level of haemoglobin was determined seven to ten days before surgery and all patients had venography of the operated leg on the fifth postoperative day. The number of patients who had donated autologous blood (1037) was similar to that who had not (1006). A significant decrease in the incidence of deep-vein thrombosis (DVT) was noted in those who had donated blood preoperatively (9.0%) compared with those who had not (13.5%) (p = 0.003). For all patients, the lower the preoperative level of haemoglobin the less likely it was that a postoperative DVT would develop. Of those who had donated blood, 0.3% developed a postoperative pulmonary embolism compared with 0.7% in those who had not, but this difference was not statistically significant. No significant difference was found in the requirements for transfusion between the two groups.

Aged↗
PubMed2000

Primary total hip replacement with a noncemented acetabular component: minimum 5-year clinical follow-up.

The results of 123 total hip replacements with a noncemented Harris-Galante I acetabular component were reviewed (minimum 5-year clinical follow-up). The average clinical follow-up was 7 years (range, 5-10.8 years). No acetabular components were revised for loosening. One cup was revised for recurrent dislocation. In 3 cases, the acetabular liner was replaced at the time of femoral component revision (aseptic loosening), and in 1 case, a liner was revised because of recurrent dislocations. Of the hips, 92 had a complete set of radiographs for analysis. None of the acetabular components had migrated. Of the 92 acetabular components, 90 were considered radiographically stable (98%). Of these hips, 24 had linear radiolucencies of < or =2 mm in < or =2 of 4 zones and were considered stable. Two cups (2%) were considered possibly unstable. One of these had a linear radiolucent line in 3 zones, and the other had an osteolytic lesion measuring 6 x 11 mm in greatest dimensions. No acetabular components were definitely unstable. The average Harris Hip Score improved from 50 points (range, 17-89 points) preoperatively to 95 points (range, 74-99 points) at the latest follow-up examination. The average Hospital for Special Surgery hip score improved from 21 points (range, 10-31 points) preoperatively to 38 points (range, 27-40) at the last follow-up examination. Noncemented acetabular fixation with the Harris-Galante I component showed excellent clinical results at a minimum of 5 years' follow-up.

Arthroplasty, Replacement, Hip↗
PubMed2000

Pneumatic compression hemodynamics in total hip arthroplasty.

A crossover study was performed to evaluate the effect of several pneumatic compression devices and active dorsoplantar flexion in 10 patients who underwent total hip arthroplasty. Using the Acuson 128XP/10 duplex ultrasound unit with a 5-MHz linear array probe, peak venous velocity and venous volume were assessed above and below the greater saphenous vein and common femoral vein junction. A computer generated randomization table was used to determine the order of the test conditions. The pneumatic compression devices evaluated included two foot pumps, one foot and calf pump, one calf pump, and three calf and thigh pumps. Statistical analyses included analysis of variance and analysis of variance with covariance between devices and patients. The covariates tested were the baseline measurements and the order in which the devices were tested. Differences between devices relate in part to the frequency and rate of inflation and the location and type of compression. Pulsatile calf and foot and calf pneumatic compression with a rapid inflation time produced the greatest increase in peak venous velocity, whereas compression of the calf and thigh showed the greatest increase in venous volume. Because patient and nursing compliance is essential to the success of mechanical prophylaxis for thromboembolic disease, the more simple, yet efficacious, devices that are easier to apply and less cumbersome appear to have a greater likelihood of success. In the active and alert patient, active dorsoplantar flexion should be encouraged.

Arthroplasty, Replacement, Hip↗
PubMed2000

Rotating hinge total knee arthroplasty in severly affected knees.

A consecutive series of 24 knees in 21 patients who received a Finn rotating hinge for primary (nine knees) or revision (15 knees) total knee arthroplasty between August 1993 and January 1997 was reviewed. The average followup was 33 months (range, 21-62 months) for all patients in the study. Seventeen patients (20 knees) were followed up for more than 2 years. Twenty-four knees (21 patients) were categorized according to Knee Society scoring criteria: 37.5% (nine knees) were Category A, 25% (six knees) were Category B, and 37.5% (nine knees) were Category C. Using the Knee Society knee and function scores, clinical and radiographic results were assessed and outcome analysis was determined. The average Knee Society knee score improved from 44 points (range, 5-64 points) before surgery to 83 points (range, 45-95 points) after surgery; the average functional score according to the Knee Society system improved from 10 points (range, 0-35 points) before surgery to 45 points (range, 0-100 points) after surgery. Pain and function markedly improved after surgery. For treatment of the most severely affected knees with compromised bone and ligamentous instability, the Finn total knee replacement appears to be an acceptable option. As a rotating hinge design, the prosthesis at early followup provides excellent pain relief, restoration of walking capacity, and stabilization, without evidence of early mechanical failure.

Adolescent↗
PubMed2000

Meta-analysis of thromboembolic prophylaxis after total knee arthroplasty.

We performed a meta-analysis of the English literature to assess the efficacy of four common regimes for thromboembolic prophylaxis after total knee arthroplasty: aspirin, warfarin, low-molecular-weight heparin (LMWH) and pneumatic compression. We reviewed 136 articles and abstracts published between January 1980 and December 1997. Papers not using routine venography and a lung scan or angiography to detect deep-venous thrombosis (DVT) and pulmonary emboli (PE) respectively, were excluded. Of the 136 studies, 23 with 6,001 patients were selected. The incidence of DVT was 53% (1,701/3,214) in the aspirin group, 45% (541/1,203) in the warfarin group, 29% (311/1,075) in the LMWH group, and 17% (86/509) in the pneumatic compression device group. Intermittent pneumatic compression devices and LMWH were significantly better than warfarin (p < 0.0001) or aspirin (p < 0.0001) in preventing DVT. The incidence of asymptomatic PE was 11.7% in the aspirin group (222/1,901), 8.2% (101/1,229) in the warfarin group and 6.3% (24/378) in the pneumatic compression group. No studies with LMWH used routine lung scans. Warfarin and pneumatic compression were significantly better than aspirin in preventing asymptomatic PE (p < 0.05). The incidence of symptomatic PE was 1.3% (23/1,800) in the aspirin group, 0.4% (2/559) in the warfarin group, 0.5% (2/416) in the LMWH group and 0% (0/177) in the pneumatic compression group. No statistically significant difference was noted between the above prophylactic regimes due to the very small incidence of symptomatic PE. Prophylaxis for thromboembolic disease in TKA may have to include a combination of some of the above regimes to incorporate their advantages.

Anticoagulants↗
PubMed1999

The incidence of venous thromboembolism after total hip arthroplasty: a specific hypotensive epidural anesthesia protocol.

We retrospectively reviewed all consecutive unilateral primary total hip arthroplasty (THA) procedures performed by 3 attending surgeons on the Arthroplasty Service at our institution from January 1, 1990, to December 31, 1993. All surgery was performed under a specific hypotensive epidural anesthesia protocol. Hypotensive epidural anesthesia at our institution provides a lower level of hypotension (mean arterial pressure of 50-60 mmHg) as compared to hypotensive anesthesia used more generally around the world (mean arterial pressure >70 mmHg). For each patient, hospital and postdischarge office records for a minimum of 3 months after surgery were reviewed for the type of postoperative screening test, the incidence of deep venous thrombosis (DVT), and the incidence of symptomatic pulmonary embolism (PE). Overall, 2,592 primary unilateral THAs were performed with 78.6% (2,037 of 2,592) of patients receiving a venogram. Our protocol for thromboembolic disease prophylaxis in these patients included aspirin postoperatively as well as antithromboembolic disease stockings and early ambulation (24-48 hours postoperatively). The 555 patients who did not receive venography were managed with a different protocol that included warfarin postoperatively as well as antithromboembolic disease stockings and early ambulation. This high-risk group consisted of patients who received warfarin preoperatively (ie, cardiac valve) or patients with a history of DVT who were to receive warfarin postoperatively, regardless of venography result. Overall, DVT was diagnosed in 10.3% (210 of 2,037) of patients who had a venogram. Of these patients who had venography, 2.3% (46 of 2,037) had an isolated proximal DVT; 6.0% (123 of 2,037), a distal DVT; and 2.0% (41 of 2,037), both a proximal and a distal DVT. Of the 87 cases of proximal DVT identified, 60.9% (53 of 87) were femoral DVT; 18.4% (16 of 87), popliteal DVT; and 20.7% (18 of 87), both femoral and popliteal DVT. Of the 164 distal DVT, 68.3% (112 of 164) were major calf DVT and 31.7% (52 of 164) were minor calf DVT. The overall incidence of major venous thrombosis (sum of proximal and major calf thrombi) was 9.8% (199 of 2,037) in patients who had venography. Ventilation-perfusion scanning was used selectively in patients symptomatic for PE. Overall, symptomatic PE was diagnosed by ventilation-perfusion scan in 1.0% (26 of 2,592) of patients, with 0.58% (15 of 2,592) of patients having an in-hospital PE. Of the 15 patients who had an in-hospital PE, 11 patients had a venogram, and only 3 of 11 were positive. Late symptomatic PE was defined from discharge (mean, 7 +/- 2 days) to 3 months after discharge from the hospital and occurred in 0.42% (11 of 2,592) of patients. One of the 11 late symptomatic PEs was fatal. In the overall study, this represents 0.04% (1 of 2,592) fatal PE. Of the 11 patients with a late symptomatic PE, 10 had venograms in the hospital, and all 10 were negative for DVT. Overall, in the patients with a positive venogram, the incidence of symptomatic PE was 1.4% (3 of 210), whereas in the patients with a negative venogram, the incidence of symptomatic PE was 0.44% (8 of 1,827). At our institution, patients who undergo primary THA performed with hypotensive epidural anesthesia, postoperative aspirin, antithromboembolic disease stockings, and early ambulation have a low risk for thromboembolic disease.

Anesthesia, Epidural↗
PubMed1999

Thromboembolic disease prophylaxis in total knee arthroplasty using intraoperative heparin and postoperative pneumatic foot compression.

A prospective study was performed to assess the clinical efficacy of intraoperative heparin combined with postoperative pneumatic foot compression and aspirin for thromboembolic disease prophylaxis after primary total knee arthroplasty (TKA). This group of 48 patients all had a primary TKA performed under epidural anesthesia. The cohort of patients was compared with a similar cohort of patients matched for age and comorbidity. The control group consisted of 61 patients (41 unilateral patients, 20 bilateral patients) with 81 TKAs who received epidural anesthesia and postoperative pneumatic foot compression and aspirin. The same surgeon and anesthesiologist performed all cases. All patients had the pneumatic foot compression device applied in the recovery room and received 325 mg of enteric-coated aspirin twice a day beginning the night of surgery. Venography was performed on the fifth postoperative day for both groups to determine the incidence of deep vein thrombosis (DVT). In the control group with postoperative pneumatic foot compression (group 1), the overall incidence of DVT was 27% (22 of 81), with 10% (8 of 81) major calf DVT and no proximal (popliteal or femoral) DVT. In the study group with intraoperative heparin and postoperative pneumatic foot compression (group 2), the overall incidence of DVT was 25% (12 of 48), with 8% (4 of 48) major calf DVT and no proximal DVT. There was no statistically significant difference between groups 1 and 2 for the incidence of overall DVT (P > .05) or major calf DVT (P > .05). No complications were associated with the use of intraoperative heparin or the pneumatic compression device, and no patient developed a symptomatic pulmonary embolism up to 3 months postoperatively. Although this study confirms that pneumatic foot compression combined with aspirin is an effective form of DVT prophylaxis after TKA, the added benefit of intraoperative heparin was not statistically proven. Although greater statistical power is needed to determine whether intraoperative heparin provides an added benefit, this study reveals a low incidence of DVT in TKA with this protocol.

Anticoagulants↗
PubMed1999

Dose response of intravenous heparin on markers of thrombosis during primary total hip replacement.

BACKGROUND: Thrombogenesis in total hip replacement (THR) begins during surgery on the femur. This study assesses the effect of two doses of unfractionated intravenous heparin administered before femoral preparation during THR on circulating markers of thrombosis. METHODS: Seventy-five patients undergoing hybrid primary THR were randomly assigned to receive blinded intravenous injection of either saline or 10 or 20 U/kg of unfractionated heparin after insertion of the acetabular component. Central venous blood samples were assayed for prothrombin F1+2 (F1+2), thrombin-antithrombin complexes (TAT), fibrinopeptide A (FPA), and D-dimer. RESULTS: No changes in the markers of thrombosis were noted after insertion of the acetabular component. During surgery on the femur, significant increases in all markers were noted in the saline group (P < 0.0001). Heparin did not affect D-dimer or TAT. Twenty units per kilogram of heparin significantly reduced the increase of F1+2 after relocation of the hip joint (P < 0.001). Administration of both 10 and 20 U/kg significantly reduced the increase in FPA during implantation of the femoral component (P < 0.0001). A fourfold increase in FPA was noted in 6 of 25 patients receiving 10 U/kg of heparin but in none receiving 20 U/kg (P = 0.03). Intraoperative heparin did not affect intra- or postoperative blood loss, postoperative hematocrit, or surgeon's subjective assessments of bleeding. No bleeding complications were noted. CONCLUSIONS: This study demonstrates that 20 U/kg of heparin administered before surgery on the femur suppresses fibrin formation during primary THR. This finding provides the pathophysiologic basis for the clinical use of intraoperative heparin during THR.

Aged↗
PubMed1998

Patella height after high tibial osteotomy with internal fixation and early motion.

The purpose of this study was to compare the incidence of patella infera in patients after high tibial osteotomy treated with either postoperative immobilization or internal fixation and early range of motion. A retrospective review of 98 patients with high tibial osteotomy was done at the authors' institution. Thirty-three patients who had secondary procedures such as concomitant ligamentous reconstruction with early motion were excluded. Therefore, 69 knees in 65 patients remained in the study cohort. Group A consisted of 32 patients (34 knees) treated with postoperative immobilization, whereas Group B included 33 patients (35 knees) treated with internal fixation and early motion. The preoperative and postoperative Insall-Salvati index, Blackburne-Peel index, and angular alignment were determined for each group. Between Groups A and B, the differences in the Insall-Salvati index and the Blackburne-Peel index were statistically significant, although the difference in angular correction was not significant. With rigid fixation and early motion the Insall-Salvati index showed that there was less postoperative shortening of the patellar tendon. The relationship of the patella to the remainder of the knee was affected less adversely as evidenced by the Blackburne-Peel index. High tibial osteotomy with internal fixation and early range of motion should result in a better knee and ease the subsequent performance of a total knee arthroplasty.

Arthroplasty, Replacement, Knee↗
PubMed1998

Ultrasound screening for deep venous thrombosis after total knee arthroplasty. 2-year reassessment.

The efficacy of ultrasound compared with ascending venography for the detection of deep venous thrombosis immediately after total knee arthroplasty was assessed after a 2-year interval. One hundred thirty-seven patients were eligible for the study; however, 31 patients received only one of the screening methods and a color Doppler examination was inconclusive in six patients. Therefore, 100 patients had a Doppler examination and a venogram. Overall, the sensitivity of ultrasound was 85%, the specificity 97%, the positive predictive value 85%, the negative predictive value 97%, and the accuracy 95%. The sensitivity in the calf was 83%, in the popliteal vein 86%, and in the femoral vein 100%. Two years ago, the initial assessment of ultrasound for the detection of deep venous thrombosis after surgery in patients who had total joint arthroplasty revealed a 75% sensitivity, 99% specificity, 91% positive predictive value, 97% negative predictive value, and 97% accuracy. The sensitivity in the calf was 83%; the sensitivity in the popliteal vein was 40%; and the sensitivity in the femoral vein was 50%. After 2 years of using this screening test with one technician and one radiologist, an improvement with this noninvasive technique was shown. However, it was found that Doppler imaging is not as sensitive as venography for detecting calf thrombi. Any imaging technique should be validated by each institution to determine the validity of the instrument and the learning curve of the technician administering the examination.

Adult↗
PubMed1998

Venous haemodynamics after total knee arthroplasty: evaluation of active dorsal to plantar flexion and several mechanical compression devices.

We performed a crossover study to evaluate the haemodynamic effect of active dorsal to plantar flexion and seven pneumatic compression devices in ten patients who had a total knee arthroplasty. Using the Acuson 128XP/10 duplex ultrasound unit with a 5MHz linear array probe, we assessed the augmentation of peak venous velocity and venous volume above and below the junction of the greater saphenous and common femoral veins in order to study both the deep and superficial venous systems. The pneumatic compression devices evaluated included two foot pumps (A-V Impulse System and PlexiPulse Foot), a foot-calf pump (PlexiPulse Foot-Calf), a calf pump (VenaFlow System) and three calf-thigh pumps (SCD System, Flowtron DVT and Jobst Athrombic Pump). The devices differed in a number of ways, including the length and location of the sleeve and bladder, the frequency and duration of activation, the rate of pressure rise, and the maximum pressure achieved. A randomisation table was used to determine the order of the test conditions for each patient. The enhancement of peak venous velocity occurred primarily in the deep venous system below the level of the saphenofemoral junction. The increases in peak venous velocity were as follows: active dorsal to plantar flexion 175%; foot pumps, A-V Impulse System 29% and PlexiPulse 65%; foot-calf pump, PlexiPulse, 221%; calf pump, VenaFlow, 302% and calf-thigh pumps, Flowtron DVT 87%, SCD System 116% and Jobst Athrombic Pump 263%. All the devices augmented venous volume, the greatest effect being seen with those incorporating calf compression. The increases in ml/min were found in the deep venous system as follows: foot pumps, A-V Impulse System 9.6 and PlexiPulse Foot 16.7; foot-calf pump, PlexiPulse, 38.1; calf pump, VenaFlow, 26.2; calf-thigh pumps, Flowtron DVT 61.5, SCD System 34.7 and Jobst Athrombic Pump 82.3. Active dorsal to plantar flexion generated 8.5 ml for a single calf contraction.

Aged↗
PubMed1996

Arthroscopic release of the posterior cruciate ligament for stiff total knee arthroplasty.

Ten posterior cruciate ligament sparing total knee arthroplasties were studied in 9 patients who underwent arthroscopic posterior cruciate ligament release to improve intractable postoperative knee stiffness and pain. Mean patient age was 64 years. Before posterior cruciate ligament release, the mean knee extension was 4 degrees (0 degrees - 10 degrees); mean knee flexion was 73.9 degrees (40 degrees - 110 degrees). The mean interval to posterior cruciate ligament release after primary total knee arthroplasty was 29 months. After release, mean extension was 1.3 degrees (0 degrees - 10 degrees) and mean flexion was 112 degrees (range, 85 degrees - 135 degrees). The average increase in flexion observed in the immediate postoperative period was 40.1 degrees (25 degrees - 60 degrees). At a mean followup of 20 months, mean extension was 1.5 degrees (0 degrees - 10 degrees), and mean flexion was 104.5 degrees (70 degrees - 125 degrees). At followup, the average increase in knee flexion was 30.5 degrees (10 degrees - 50 degrees). Before arthroscopic posterior cruciate ligament release, the average Knee Society knee and function scores were 70.9 and 71, respectively. At followup, the average Knee Society knee and function scores were 86.4 and 88, respectively. The Knee Society pain score improved from 33.5 preoperatively to 42 postoperatively. All patients reported subjective improvements in pain and stiffness. Eight patients (88%) reported satisfaction with the procedure. Two patients (22%) eventually required revision total knee arthroplasty.

Adult↗
PubMed1996

Prophylaxis against deep venous thrombosis after total knee arthroplasty. Pneumatic plantar compression and aspirin compared with aspirin alone.

A prospective, randomized study was conducted to assess the efficacy of pulsatile pneumatic plantar compression for prophylaxis against deep venous thrombosis after total knee arthroplasty performed with use of regional anesthesia. One hundred and twenty-two patients (164 knees) who were scheduled to have a unilateral or a one-stage bilateral total knee arthroplasty were separately randomized to be managed with either aspirin alone or the pulsatile pneumatic plantar-compression device and aspirin. The prevalence of deep venous thrombosis was 27 per cent (twenty-two of eighty-one knees) in the group treated with pneumatic plantar compression compared with 59 per cent (forty-nine of eighty-three knees) in the patients managed with aspirin alone (the control group) (p < 0.001). A significant difference was also noted in the group that had had a unilateral arthroplasty (a prevalence of 27 per cent [eleven of forty-one knees] in the group treated with pneumatic plantar compression, compared with 67 per cent [twenty-six of thirty-nine knees] in that treated with aspirin alone; p < 0.006) and in the group that had had a one-stage bilateral procedure (a prevalence of 28 per cent [eleven of forty knees] in the group treated with pneumatic plantar compression, compared with 52 per cent [twenty-three of forty-four knees] in that treated with aspirin alone; p < 0.03). No proximal thrombi were noted in any patient who used the pulsatile pneumatic plantar-compression device, while the prevalence of proximal thrombosis in the popliteal or femoral veins was 14 per cent (twelve of eighty-three knees) in the group treated with aspirin alone (p < 0.0003). In the group treated with a unilateral procedure and aspirin alone the prevalence of proximal thrombosis was 13 per cent (five of thirty-nine knees; p < 0.02), while in the group treated with a bilateral procedure and aspirin alone it was 16 per cent (seven of forty-four knees; p < 0.01). Only in the patients who had had a unilateral procedure was use of the compression device associated with significantly less edema postoperatively than was use of aspirin alone. The change between the preoperative and postoperative circumferences of the thigh and leg was significantly less (9 +/- 4.1 millimeters [mean and standard deviation] less for the thigh [p < 0.01] and 6 +/- 3.9 millimeters less for the leg [p < 0.049]) with the compression device than with aspirin alone. In addition, there was significantly less mean drainage (98 +/- 61.1 milliliters) in the group treated with a unilateral procedure and pneumatic compression, compared with that treated with a unilateral procedure and aspirin alone (p < 0.041). An internal timer of the compression device was used to assess the compliance of the patient with use of the device, and a relationship between deep venous thrombosis and the total duration of treatment with the device was found. The patients in whom deep venous thrombosis did not develop used the device for a mean of 96 +/- 23.4 hours (range, sixty to 164 hours) postoperatively, or 19.2 +/- 5.1 hours a day, while those in whom thrombosis developed used it for a mean of 67 +/- 21.1 hours (range, twenty-six to 101 hours), or 13.4 +/- 4.3 hours a day (p < 0.001). No untoward effects were noted in any patient who used the device. This study confirms the safety and efficacy of pulsatile pneumatic plantar compression and aspirin compared with aspirin alone and supports the use of mechanical compression for prophylaxis against deep venous thrombosis and for reduction of edema in patients who have had a total knee arthroplasty. In addition, we found a direct relationship between compliance with the use of this device and its efficacy in reducing deep venous thrombosis.

Arthritis, Rheumatoid↗