Percentage of Inadequate Phlebograms and Observer Agreement in Thromboprophylactic Multicenter Trials Using Standardized Methodology and Central Assessment

This study examines inadequacy rates for phlebography in two multicenter trials for the prevention of post-operative DVT and determines inter- and intra-observer variability in evaluating phlebograms. A total of 991 (I) and 385 (II) patients underwent bilateral phlebography in two studies of thromboprophylaxis. Phlebography was performed using a standard method designed to visualize and assess all deep veins. Each vein was scored as normal, DVT or inadequate by both local and central assessment. The study showed low inadequacy rates for phlebograms of 12.2% (121/991) and 6.5% (25/385). Inter-observer agreement (local vs. central assessment) was moderate in both studies (1:74.8%, Kappa-value 0.41; II: 82.6%, Kappa-value 0.51). Good intraobserver agreement (within the central assessment group) was observed (I: 88.8%, Kappa-value 0.75). This study demonstrates low inadequacy rates for phlebograms using a standardized methodology and superior intra-observer agreement compared to inter-observer agreement and supports the importance of central assessment of phlebograms in thromboprophylactic multicenter trials to reduce observer variability.

Bone Mass Determination from Microradiographs by Computer-Assisted Videodensitometry

Aluminium was evaluated as a reference substance in the assessment of rabbit cortical bone by microradiography followed by videodensitometry. Ten dense, cortical-bone specimens from the same tibia diaphysis were microradiographed using prefiltered 27 kV roentgen radiation together with aluminium step wedges and bone simulating phantoms for calibration. Optimally exposed and processed plates were analysed by previously described computer-assisted videodensitometry. For comparison, the specimens were analysed by physico-chemical methods. A strict proportionality was found between the ‘aluminium equivalent mass’ and the ash weight of the specimens. The total random error was low with a coefficient of variation within 1.5 per cent. It was concluded that aluminium is an appropriate reference material in the determination of cortical bone, which it resembles in effective atomic number and thus x-ray attenuation characteristics. The ‘aluminium equivalent mass’ is suitably established as the standard of expressing the results of bone assessment by microradiography.

Phlebographic Findings in Venous Thrombosis following Total Hip Replacement

The specific appearance of venous thrombosis following total hip replacement was analysed by reviewing 45 positive phlebograms from 122 patients participating in a concurrent trial against thromboembolism. Almost all thrombi were asymptomatic and non-occlusive. Forty-four per cent of the thrombi were excusively confined to the calf. The muscular veins were the most common location, followed by the fibular and posterior tibial veins. Ipsilateral thrombi predominated over thrombi in the non-operated leg. Thirty-six per cent were located in the ipsilateral thigh and the major part was found in the proximal part of the femoral veins. Nearly all were related to valve cusps, free-floating and were of small size. In 20 per cent, thrombi were found in both the calf and the thigh. Neither contralateral thigh thrombi, nor pelvic thrombi were found. Of 25 patients with pulmonary embolism, all but 3 asymptomatic, 64 per cent had thigh thrombi. A multifocal location of thrombi was present but two major types of thrombosis were distinguished; calf vein thrombosis probably due to venous stasis and femoral thrombosis caused by the local surgical trauma.

Bone Mass Determination from Microradiographs by Computer-Assisted Videodensitometry

The mass of hard-tissue specimens is assessed by optimised microradiography followed by computer-assisted videodensitometry. Radiographs are produced with 27 kV roentgen radiation, filtered through 0.5 to 1 mm of aluminium, on high-resolution glass plates. Aluminium step wedges are used for density calibration, the result being expressed as ‘aluminium equivalent mass’. The plates are subjected to digital image analysis by an operator in interaction with a computer-based image processor, a television camera being used for image input. The program stored in the computer provides calibration of geometry and—via the stepwedge images—of densitometry, background adjustment, etc. Measurement takes place by integration over the specimen-image area. No assumptions being needed concerning a specific attenuation model, the errors stemming from the common presumption of exponential attenuation are eliminated. Density profiles or maps of mass distribution are readily obtained from the computer. From measurements of aluminium phantom samples, the total random error (coefficient of variation) was determined at 1.8 per cent, the microradiographic and videodensitometric procedures contributing 1.6 per cent and 0.9 per cent, respectively, whereas the systematic error was negligible. Since specimens need not be sectioned, this method does not interfere with subsequent histologic preparation.

Computed Tomography in Massive Pulmonary Embolism

The usefulness of computed tomography (CT) for the diagnosis of pulmonary embolism (PE) was demonstrated in two cases. Employing dynamic, contrast-enhanced CT, both direct and indirect signs of PE may be rapidly and conveniently demonstrated. Possible contraindications for therapy may be diagnosed simultaneously and follow-up examinations after therapy may be readily performed. The method serves as a good complement when PE must be verified before treatment with potent agents.

Soft-Tissue Radiography, Computed Tomography, and Ultrasonography of Partial Achilles Tendon Ruptures

Ultrasonography (US) was compared with soft-tissue radiography (STR) and computed tomography (CT) for demonstration of partial Achilles tendon ruptures. Thirty-nine patients suffering from chronic localized painful Achilles tendon swelling were examined. The patients had all undergone a previous clinical examination, resulting in a suspicion of a non-healed partial tear in 62 out of the 78 tendons. STR showed unspecific tendon pathology such as thickening and diffuse tendon margins. CT resulted in a better delineation of intra- as well as extratendinous abnormalities compared to STR. Various pathologic changes were seen on CT in 54 tendons and in 29 of these, localized intratendinous hypodensities indicated partial ruptures. At US, abnormal changes were observed in 69 tendons, of which 54 had discontinuity of tendon fibers, focal hypoechoic areas, and localized swelling indicating partial ruptures. In 9 cases with surgically proven partial ruptures, US was correct in all cases, while CT was false-negative in 3. STR only showed localized swelling. It was concluded that US was a better method than STR and CT for the detection of partial ruptures and the US findings correlated well with the surgical findings.

A phase I/II study of neoadjuvant chemotherapy with Pemetrexed (Alimta) in rectal cancer

AIM

The aim was to assess the feasibility of preoperative chemotherapy and possible tumour response using Pemetrexed (Alimta) in rectal cancer.

METHOD

The study was a prospective, non-randomized, single-centre phase I/II feasibility trial. 37 patients with resectable rectal cancer were recruited and given three 3-week cycles of preoperative Pemetrexed therapy. Tumour size and stage were assessed by MRI scans before and after chemotherapy. Treatment tolerability and response such as changes in tumour size and symptoms were assessed.

RESULTS

All patients completed the chemotherapy. Whilst mild side effects were frequent (grade 1, 34/37), the risk of severe effects was limited (grade 3 or 4, 4/37). Overall, there was a significant reduction in tumour size (p < 0.001). By RECIST criteria, one patient had tumour progression, 23/36 had stable disease and 12 patients had a response of up to 65%. There was also a significant decrease in the number of pre-treatment symptoms (p < 0.018) including reduction of bleeding and diarrhoea/constipation.

CONCLUSION

Preoperative (Neoadjuvant) treatment with Pemetrexed was feasible in studied patients. Serious side effects were limited and a radiological tumour response or stable disease was seen in a majority of patients.

Prevention of venous thromboembolism with an oral factor Xa inhibitor, YM150, after total hip arthroplasty. A dose finding study (ONYX-2)

BACKGROUND

Anticoagulant prophylaxis substantially reduces the risk of venous thromboembolism (VTE) after major orthopedic surgery. The direct factor Xa inhibitor YM150 is currently under investigation for the prevention of VTE, stroke and ischemic vascular events in patients after orthopedic surgery, with atrial fibrillation and with acute coronary syndrome, respectively.

OBJECTIVES

To investigate the efficacy and safety of YM150 for the prevention of VTE following elective total hip arthroplasty.

PATIENTS/METHODS

Patients were randomized to postoperative, once-daily, oral YM150 (5, 10, 30, 60 or 120 mg) (double-blind) or preoperative subcutaneous (open label) enoxaparin (40 mg) for 5 weeks. The primary efficacy endpoint comprised VTE diagnosed by mandatory bilateral venography or verified symptomatic deep vein thrombosis (DVT) plus all deaths up to 9 days after surgery. The primary safety outcome was major bleeding up to 9 days after surgery.

RESULTS

Primary efficacy endpoint: of 1017 patients randomized, 960 patients were evaluable for safety and 729 patients for efficacy. A dose-related decrease in VTE incidence from YM150 5 to 60 mg (P = 0.0005) and from 5 to 120 mg (P = 0.0002) was found. The VTE incidence was 27.4%, 31.7%, 19.3%, 13.3% and 14.5% for 5, 10, 30, 60 and 120 mg YM150, respectively, and 18.9% for enoxaparin. Primary safety endpoint: there was one major bleed with YM150 (60 mg) and one with enoxaparin.

CONCLUSIONS

The oral direct FXa inhibitor YM150 demonstrated a significant dose response regarding efficacy. Doses from 30 to 120 mg had comparable efficacy to enoxaparin, without compromising safety regarding major bleeding events.

Oral dabigatran etexilate vs. subcutaneous enoxaparin for the prevention of venous thromboembolism after total knee replacement: the RE-MODEL randomized trial

BACKGROUND

Oral anticoagulants, such as dabigatran etexilate, an oral, direct thrombin inhibitor, that do not require monitoring or dose adjustment offer potential for prophylaxis against venous thromboembolism (VTE) after total knee replacement surgery.

METHODS

In this randomized, double-blind study, 2076 patients undergoing total knee replacement received dabigatran etexilate, 150 mg or 220 mg once-daily, starting with a half-dose 1-4 hours after surgery, or subcutaneous enoxaparin 40 mg once-daily, starting the evening before surgery, for 6-10 days. Patients were followed-up for 3 months. The primary efficacy outcome was a composite of total VTE (venographic or symptomatic) and mortality during treatment, and the primary safety outcome was the incidence of bleeding events.

RESULTS

The primary efficacy outcome occurred in 37.7% (193 of 512) of the enoxaparin group versus 36.4% (183 of 503) of the dabigatran etexilate 220 mg group (absolute difference, -1.3%; 95% CI, -7.3 to 4.6) and 40.5% (213 of 526) of the 150 mg group (2.8%; 95% CI, -3.1 to 8.7). Both doses were noninferior to enoxaparin based on the pre-specified noninferiority criterion. The incidence of major bleeding did not differ significantly between the three groups (1.3% versus 1.5% and 1.3% respectively). No significant differences in the incidences of liver enzyme elevation and acute coronary events were observed during treatment or follow-up.

CONCLUSIONS

Dabigatran etexilate (220 mg or 150 mg) was at least as effective and with a similar safety profile as enoxaparin for prevention of VTE after total knee-replacement surgery.

Oral dabigatran etexilate vs. subcutaneous enoxaparin for the prevention of venous thromboembolism after total knee replacement: the RE-MODEL randomized trial

BACKGROUND

Oral anticoagulants, such as dabigatran etexilate, an oral, direct thrombin inhibitor, that do not require monitoring or dose adjustment offer potential for prophylaxis against venous thromboembolism (VTE) after total knee replacement surgery.

METHODS

In this randomized, double-blind study, 2076 patients undergoing total knee replacement received dabigatran etexilate, 150 mg or 220 mg once-daily, starting with a half-dose 1-4 hours after surgery, or subcutaneous enoxaparin 40 mg once-daily, starting the evening before surgery, for 6-10 days. Patients were followed-up for 3 months. The primary efficacy outcome was a composite of total VTE (venographic or symptomatic) and mortality during treatment, and the primary safety outcome was the incidence of bleeding events.

RESULTS

The primary efficacy outcome occurred in 37.7% (193 of 512) of the enoxaparin group versus 36.4% (183 of 503) of the dabigatran etexilate 220 mg group (absolute difference, -1.3%; 95% CI, -7.3 to 4.6) and 40.5% (213 of 526) of the 150 mg group (2.8%; 95% CI, -3.1 to 8.7). Both doses were noninferior to enoxaparin based on the pre-specified noninferiority criterion. The incidence of major bleeding did not differ significantly between the three groups (1.3% versus 1.5% and 1.3% respectively). No significant differences in the incidences of liver enzyme elevation and acute coronary events were observed during treatment or follow-up.

CONCLUSIONS

Dabigatran etexilate (220 mg or 150 mg) was at least as effective and with a similar safety profile as enoxaparin for prevention of VTE after total knee-replacement surgery.

A dose escalation study of YM150, an oral direct factor Xa inhibitor, in the prevention of venous thromboembolism in elective primary hip replacement surgery

BACKGROUND

YM150, a new oral direct factor Xa inhibitor is used as prophylaxis for venous thromboembolism (VTE), a well-known risk after orthopaedic surgery.

OBJECTIVES

To assess the safety and efficacy of thromboprophylaxis with YM150 in a dose escalation study.

PATIENTS/METHODS

Patients (174) undergoing hip replacement surgery were randomized per cohort to oral once daily YM150 or subcutaneous enoxaparin (40 mg daily) in a 4:1 ratio for 7-10 days treatment. The YM150 doses were 3, 10, 30 and 60 mg by sequential four-dose escalation cohorts. The primary endpoint was major and/or clinically relevant non-major bleeding. The incidence of VTE was defined as a composite of verified symptomatic events and/or positive findings at bilateral venography on the last treatment day. An independent adjudication committee evaluated blindly the outcomes of the open-label study.

RESULTS

No major and three clinically relevant non-major bleeds were reported, 1 (2.9%; 95% CI, 0.1-15.1) in the 3 mg and 2 (5.7%; 95% CI, 1.0-18.8) in the 10 mg YM150 dose groups. Of 147 patients (84%) with an evaluable venogram, VTE was observed in 51.9% (95% CI, 31.9-71.4), 38.7% (95% CI, 22.6-57.0), 22.6% (95% CI, 9.7-39.4), and 18.5% (95% CI, 7.5-36.5) in the YM150 dose groups 3, 10, 30 and 60 mg, respectively. A significant YM150 dose-related trend in VTE incidence was found (P=0.006). VTE with enoxaparin was 38.7% (95% CI, 22.6-57.0).

CONCLUSIONS

YM150, 10-60 mg daily, starting 6-10 h after primary hip replacement, was shown to be safe, well tolerated and effective.

Ultrasound screening for asymptomatic deep vein thrombosis after major orthopaedic surgery: the VENUS study

BACKGROUND

Venography is currently used to assess the incidence of deep vein thrombosis (DVT) in dose-finding and confirmatory trials of new antithrombotic agents. Centrally adjudicated, complete compression ultrasound (CCUS) could be a non-invasive alternative to venography.

OBJECTIVES

A substudy of two, similarly designed, phase IIb trials of a novel, oral anticoagulant for the prevention of venous thromboembolism after elective hip or knee arthroplasty was undertaken to validate CCUS against venography.

PATIENTS/METHODS

Patients received study drugs until mandatory, bilateral venography was performed 7 +/- 2 days after surgery. CCUS was performed within 24 h after venography by sonographers blinded to the venography result. Sonographers were trained and certified for the standardized examination and documentation procedure. Venograms and sonograms were adjudicated centrally at different sites by two independent readers; discrepancies between readers were resolved by consensus.

RESULTS

A total of 1104 matching pairs of evaluable venograms and sonograms were obtained from the participants of the two trials (n = 1435): 19% of venograms and 20% of sonograms were not evaluable. The observed frequency of any DVT was 18.9% with venography and 11.5% with CCUS. Sensitivity of CCUS compared with venography was 31.1% for any DVT (95% confidence interval 23.4, 38.9), 21.0% (2.7, 39.4) for proximal DVT, and 30.8% (23.1, 38.6) for distal DVT. The figures for specificity were 93.0% (91.0, 95.1), 98.7% (98.0, 99.5), and 93.3% (91.5, 95.3), respectively.

CONCLUSIONS

Based on these results, centrally adjudicated CCUS will be unable to replace venography for DVT screening early after major orthopaedic surgery in studies evaluating anticoagulant drugs.

Oral, direct Factor Xa inhibition with BAY 59-7939 for the prevention of venous thromboembolism after total hip replacement

BACKGROUND

Joint replacement surgery is an appropriate model for dose-ranging studies investigating new anticoagulants.

OBJECTIVES

To assess the efficacy and safety of a novel, oral, direct factor Xa (FXa) inhibitor--BAY 59-7939--relative to enoxaparin in patients undergoing elective total hip replacement.

METHODS

In this double-blind, double-dummy, dose-ranging study, patients were randomized to oral BAY 59-7939 (2.5, 5, 10, 20, or 30 mg b.i.d.), starting 6-8 h after surgery, or s.c. enoxaparin 40 mg once daily, starting on the evening before surgery. Treatment was continued until mandatory bilateral venography was performed 5-9 days after surgery.

RESULTS

Of 706 patients treated, 548 were eligible for the primary efficacy analysis. The primary efficacy endpoint was the incidence of any deep vein thrombosis, non-fatal pulmonary embolism, and all-cause mortality; rates were 15%, 14%, 12%, 18%, and 7% for BAY 59-7939 2.5, 5, 10, 20, and 30 mg b.i.d., respectively, compared with 17% for enoxaparin. The primary efficacy analysis did not demonstrate any significant trend in dose-response relationship for BAY 59-7939. The primary safety endpoint was major, postoperative bleeding; there was a significant increase in the frequency of events with increasing doses of BAY 59-7939 (P = 0.045), but no significant differences between individual BAY 59-7939 doses and enoxaparin.

CONCLUSIONS

When efficacy and safety were considered together, the oral, direct FXa inhibitor BAY 59-7939, at 2.5-10 mg b.i.d., compared favorably with enoxaparin for the prevention of venous thromboembolism in patients undergoing elective total hip replacement.

BAY 59-7939: an oral, direct factor Xa inhibitor for the prevention of venous thromboembolism in patients after total knee replacement. A phase II dose-ranging study

BACKGROUND

BAY 59-7939, a novel, oral, direct factor Xa inhibitor, is in clinical development for the prevention of venous thromboembolism (VTE), a frequent complication following orthopaedic surgery.

METHODS

In a multicenter, parallel-group, double-blind, double-dummy study, 621 patients undergoing elective total knee replacement were randomly assigned to oral BAY 59-7939 (2.5, 5, 10, 20, and 30 mg b.i.d., initiated 6-8 h postsurgery), or subcutaneous enoxaparin (30 mg b.i.d., initiated 12-24 h postsurgery). Treatment was continued until mandatory bilateral venography 5-9 days after surgery. The primary efficacy endpoint was a composite of any deep vein thrombosis (proximal and/or distal), confirmed non-fatal pulmonary embolism and all-cause mortality during treatment. The primary safety endpoint was major, postoperative bleeding during treatment.

RESULTS

Of the 613 patients treated, 366 (59.7%) were evaluable for the primary efficacy analysis. The primary efficacy endpoint occurred in 31.7%, 40.4%, 23.3%, 35.1%, and 25.4% of patients receiving 2.5, 5, 10, 20 and 30 mg b.i.d. doses of BAY 59-7939, respectively (test for trend, P = 0.29), compared with 44.3% in the enoxaparin group. The frequency of major, postoperative bleeding increased with increasing doses of BAY 59-7939 (test for trend, P = 0.0007), with no significant difference between any dose group compared with enoxaparin. Bleeding endpoints were lower for the 2.5-10 mg b.i.d. doses compared with higher doses of BAY 59-7939.

CONCLUSIONS

Oral administration of 2.5-10 mg b.i.d. of BAY 59-7939, early in the postoperative period, showed potential efficacy and an acceptable safety profile, similar to enoxaparin, for the prevention of VTE in patients undergoing elective total knee replacement.

Dose escalating safety study of a new oral direct thrombin inhibitor, dabigatran etexilate, in patients undergoing total hip replacement: BISTRO I

BACKGROUND

Dabigatran etexilate (BIBR 1048) is an oral direct thrombin inhibitor undergoing evaluation for the prevention of venous thromboembolism (VTE) following total hip replacement. Following oral administration, dabigatran etexilate is rapidly converted to its active form dabigatran (BIBR 953 ZW).

OBJECTIVES

To determine the safe therapeutic range of dabigatran etexilate following total hip replacement.

METHODS

In a multicenter, open-label, dose-escalating study, 314 patients received oral doses of dabigatran etexilate (12.5, 25, 50, 100, 150, 200 and 300 mg twice daily or 150 and 300 mg once daily) administered 4-8 h after surgery, for 6-10 days. Dose escalation was based on clinical and pharmacokinetic data. The primary safety outcome was major bleeding. The primary efficacy outcome included venographic deep vein thrombosis (DVT), symptomatic DVT and pulmonary embolism, during the treatment period.

RESULTS

No major bleeding event was observed in any group, but two patients at the highest dose (300 mg twice daily) suffered bleeding from multiple sites associated with reduced renal clearance and prolonged pharmacodynamic (PD) parameters. A dose-response was demonstrated for minor bleeding events. Of the 289 treated patients, 225 patients had evaluable venograms. The overall incidence of DVT was 12.4% (28/225 patients). There was no consistent relationship between the dose and incidence of DVT, the highest incidence in any group being 20.8% (5/24 patients). The lowest dose (12.5 mg twice daily) showed a high rate of proximal DVT [12.5% (3/24)] and no increase in PD parameters. Peak and trough plasma concentrations, area under the dabigatran plasma concentration-time curve and PD parameters also increased in proportion with the dose. Higher dabigatran plasma concentrations were associated with lower DVT rates. Approximately 20% of the patients had low plasma concentrations after the first dose suggesting further optimization of the preliminary tablet formulation is required.

CONCLUSIONS

Dabigatran etexilate demonstrates an acceptable safety profile, with a therapeutic window above 12.5 mg and below 300 mg twice daily. The low number of VTE events within each treatment group indicates a satisfactory antithrombotic potential, although the study was not powered for an efficacy analysis. Additional studies are ongoing to optimize oral absorption and the efficacy/safety balance.

A new oral direct thrombin inhibitor, dabigatran etexilate, compared with enoxaparin for prevention of thromboembolic events following total hip or knee replacement: the BISTRO II randomized trial

BACKGROUND

Dabigatran etexilate is an oral direct thrombin inhibitor undergoing evaluation for the prevention of venous thromboembolism (VTE) following orthopedic surgery.

METHODS

In a multicenter, parallel-group, double-blind study, 1973 patients undergoing total hip or knee replacement were randomized to 6-10 days of oral dabigatran etexilate (50, 150 mg twice daily, 300 mg once daily, 225 mg twice daily), starting 1-4 h after surgery, or subcutaneous enoxaparin (40 mg once daily) starting 12 h prior to surgery. The primary efficacy outcome was the incidence of VTE (detected by bilateral venography or symptomatic events) during treatment.

RESULTS

Of the 1949 treated patients, 1464 (75%) patients were evaluable for the efficacy analysis. VTE occurred in 28.5%, 17.4%, 16.6%, 13.1% and 24% of patients assigned to dabigatran etexilate 50, 150 mg twice daily, 300 mg once daily, 225 mg twice daily and enoxaparin, respectively. A significant dose-dependent decrease in VTE occurred with increasing doses of dabigatran etexilate (P < 0.0001). Compared with enoxaparin, VTE was significantly lower in patients receiving 150 mg twice daily [odds ratio (OR) 0.65, P = 0.04], 300 mg once daily (OR 0.61, P = 0.02) and 225 mg twice daily (OR 0.47, P = 0.0007). Compared with enoxaparin, major bleeding was significantly lower with 50 mg twice daily (0.3% vs. 2.0%, P = 0.047) but elevated with higher doses, nearly reaching statistical significance with the 300 mg once-daily dose (4.7%, P = 0.051).

CONCLUSIONS

Oral administration of dabigatran etexilate, commenced early in the postoperative period, was effective and safe across a range of doses. Further optimization of the efficacy/safety balance will be addressed in future studies.

Dose escalating safety study of a new oral direct thrombin inhibitor, dabigatran etexilate, in patients undergoing total hip replacement: BISTRO I

BACKGROUND

Dabigatran etexilate (BIBR 1048) is an oral direct thrombin inhibitor undergoing evaluation for the prevention of venous thromboembolism (VTE) following total hip replacement. Following oral administration, dabigatran etexilate is rapidly converted to its active form dabigatran (BIBR 953 ZW).

OBJECTIVES

To determine the safe therapeutic range of dabigatran etexilate following total hip replacement.

METHODS

In a multicenter, open-label, dose-escalating study, 314 patients received oral doses of dabigatran etexilate (12.5, 25, 50, 100, 150, 200 and 300 mg twice daily or 150 and 300 mg once daily) administered 4-8 h after surgery, for 6-10 days. Dose escalation was based on clinical and pharmacokinetic data. The primary safety outcome was major bleeding. The primary efficacy outcome included venographic deep vein thrombosis (DVT), symptomatic DVT and pulmonary embolism, during the treatment period.

RESULTS

No major bleeding event was observed in any group, but two patients at the highest dose (300 mg twice daily) suffered bleeding from multiple sites associated with reduced renal clearance and prolonged pharmacodynamic (PD) parameters. A dose-response was demonstrated for minor bleeding events. Of the 289 treated patients, 225 patients had evaluable venograms. The overall incidence of DVT was 12.4% (28/225 patients). There was no consistent relationship between the dose and incidence of DVT, the highest incidence in any group being 20.8% (5/24 patients). The lowest dose (12.5 mg twice daily) showed a high rate of proximal DVT [12.5% (3/24)] and no increase in PD parameters. Peak and trough plasma concentrations, area under the dabigatran plasma concentration-time curve and PD parameters also increased in proportion with the dose. Higher dabigatran plasma concentrations were associated with lower DVT rates. Approximately 20% of the patients had low plasma concentrations after the first dose suggesting further optimization of the preliminary tablet formulation is required.

CONCLUSIONS

Dabigatran etexilate demonstrates an acceptable safety profile, with a therapeutic window above 12.5 mg and below 300 mg twice daily. The low number of VTE events within each treatment group indicates a satisfactory antithrombotic potential, although the study was not powered for an efficacy analysis. Additional studies are ongoing to optimize oral absorption and the efficacy/safety balance.

The direct thrombin inhibitor melagatran followed by oral ximelagatran compared with enoxaparin for the prevention of venous thromboembolism after total hip or knee replacement: the EXPRESS study

BACKGROUND

Ximelagatran and its subcutaneous (s.c.) form melagatran are novel direct thrombin inhibitors for the prevention and treatment of thromboembolic disease.

METHODS

In a double-blind study, 2835 consecutive patients undergoing total hip or knee replacement were randomized to either melagatran/ximelagatran or enoxaparin. Melagatran 2 mg was started immediately before surgery; 3 mg was then administered postoperatively, followed by 24 mg of oral ximelagatran b.i.d. beginning the next day. Enoxaparin 40 mg, administered subcutaneously o.d., was started 12 h before surgery. Both treatments were continued for 8-11 days. The main efficacy outcome measures were major venous thromboembolism (VTE); [proximal deep vein thrombosis (DVT), non-fatal and/or fatal pulmonary embolism (PE), death where PE could not be ruled out], and total VTE (proximal and distal DVT; PE; death from all causes). DVT was detected by mandatory bilateral ascending venography at the end of the treatment period or earlier if clinically suspected. The main safety outcome was bleeding.

RESULTS

The rates of major and total VTE were significantly lower in the melagatran/ximelagatran group compared with the enoxaparin group (2.3% vs. 6.3%, P = 0.0000018; and 20.3% vs. 26.6%, P < 0.0004, respectively). Fatal bleeding, critical site bleeding and bleeding requiring reoperation did not differ between the two groups. 'Excessive bleeding as judged by the investigator' was more frequent with melagatran/ximelagatran than with enoxaparin.

CONCLUSIONS

In patients undergoing total hip or knee replacement, preoperatively initiated s.c. melagatran followed by oral ximelagatran was significantly more effective in preventing VTE than preoperatively initiated s.c. enoxaparin.

Central assessment of bilateral phlebograms in a major multicentre thromboprophylactic trial. Reasons for inadequate results

PURPOSE

To determine the cause of inadequate bilateral phlebograms at central assessment. A major antithrombotic trial was evaluated to identify and apply corrective measures for reducing inadequate results in future multicentre trials.

MATERIAL AND METHODS

The inadequate results in 253 out of 1,827 patients having undergone bilateral phlebography following total hip replacement were reviewed by two central assessors using strict criteria for evaluability. The reasons for inadequate findings were assessed and ranked.

RESULTS AND CONCLUSION

Insufficient contrast filling, especially of the anterior tibial, common femoral and iliac veins, was the most common reason for disqualifying examinations. Unilateral examinations and obscuring metallic devices were the second and third most common reasons, respectively. Efforts should be made to standardize the phlebography technique, to use a large volume of contrast without tourniquets, and to obtain an appropriate number of views to visualize the deep veins.

Closing patellar tendon defects after anterior cruciate ligament reconstruction: absence of any benefit

The most common graft in anterior cruciate ligament (ACL) surgery involves using the central one-third of the patellar tendon. Knowledge concerning the postoperative disability after harvesting the patellar tendon is, however, limited. The aim of this study was to evaluate the impact patellar tendon suture and bone grafting of the patellar bone defect might have in terms of functional outcome and patellofemoral pain after harvesting the bone-tendon-bone graft, compared with leaving the harvested site non-sutured and non-grafted. Sixty patients, scheduled for arthroscopically assisted ACL reconstruction, were randomly allocated to two groups. In group I, suture of the patellar tendon and bone grafting of the patellar defect were performed. In group II, the tendon gap and the patellar defect were left open. Preoperatively, there was no significant difference between the groups when comparing objective knee stability, as measured with a KT-1000 laxity meter, Lysholm score, Tegner activity level, IKDC score, or patello-femoral pain score. Both groups had a significantly improved Lysholm score at the 2-year follow-up, without any difference between them. Tegner's activity level was significantly lower at follow-up, compared with the pre-injury level in both groups. The patellofemoral pain score improved significantly after the reconstruction, without any difference between the groups. Ultrasonography did not reveal any difference between the groups in terms of healing of the tendon gap. This study revealed no differences in donor site morbidity, functional outcome, patellofemoral pain score or knee joint stability between the two treatment groups. The conclusion is that suture of the patellar tendon and bone grafting of the patellar defect do not improve the functional results or reduce donor site morbidity after arthroscopically assisted ACL.

Surgical treatment of concomitant chronic ankle instability and longitudinal rupture of the peroneus brevis tendon

Chronic lateral ankle instability can be associated with a longitudinal rupture of the peroneus brevis tendon. Patients with these problems have atypical posterolateral or retromalleolar pain, as well as clinical signs of ligamentous instability. This injury is frequently concomitant with lateral ligament injuries and the injury mechanism is similar; however, the tendon rupture is often missed. Laxity or insufficiency of the superior peroneal retinaculum allows the anterior part of the peroneus brevis tendon to ride upon the sharp posterior fibular edge, resulting in a longitudinal rupture of the tendon. We report on the results after surgical treatment in nine patients (10 ankles) with combined instability of the lateral ankle ligaments and longitudinal rupture of the peroneus brevis tendon. All these patients underwent surgical repair of the peroneus tendon, reconstruction of the superior peroneal retinaculum, removal of the sharp posterior edge of the fibula and correction of the ligamentous instability of the anterior talofibular and calcaneofibular ligaments. One constant finding at surgery was a longitudinal intratendineal rupture of the peroneus brevis tendon combined with insufficiency of the superior peroneal retinaculum and insufficiency of the lateral ligaments. At follow-up 3 (2-5) years post-operatively, the functional results were excellent or good in nine ankles and fair in one. All the patients with excellent or good results had resumed their preinjury activity level. We conclude that this lesion should be suspected in patients with lateral ligamentous instability, combined with retromalleolar pain. In these cases, it is important to address both the tendon rupture and the ligamentous insufficiency.

A comparison of recombinant hirudin with a low-molecular-weight heparin to prevent thromboembolic complications after total hip replacement

BACKGROUND

Patients who undergo total hip replacement have a high risk of thromboembolic complications. Recombinant hirudin (desirudin), a specific inhibitor of thrombin, represents a new development in antithrombotic therapy. We compared the efficacy and safety of desirudin with those of a low-molecular-weight heparin (enoxaparin) for the prevention of thromboembolic complications in patients undergoing primary total hip replacement.

METHODS

Both treatments, which were assigned in a randomized, double-blind manner, were started preoperatively: enoxaparin on the evening before surgery, and desirudin within 30 minutes before the start of surgery. The dose of desirudin was 15 mg subcutaneously twice daily, and the dose of enoxaparin was 40 mg subcutaneously once daily. The duration of treatment was 8 to 12 days. Deep-vein thrombosis was verified by bilateral venography performed at the end of the treatment period or earlier, if there were clinical signs of deep-vein thrombosis.

RESULTS

At 31 centers in 10 European countries, 2079 eligible patients were randomly assigned to receive desirudin or enoxaparin. A total of 1587 patients were included in the primary analysis of efficacy. In the desirudin group, as compared with the enoxaparin group, there was a significantly lower rate of proximal deep-vein thrombosis (4.5 vs. 7.5 percent, P=0.01; relative reduction in risk, 40.3 percent) and a lower overall rate of deep-vein thrombosis (18.4 vs. 25.5 percent, P=0.001; relative reduction in risk, 28.0 percent). The safety profiles were similar in the two treatment groups.

CONCLUSIONS

When administered 30 minutes before total hip replacement surgery, desirudin is more effective than enoxaparin in preventing deep-vein thrombosis.

Prevention of thromboembolism with use of recombinant hirudin. Results of a double-blind, multicenter trial comparing the efficacy of desirudin (Revasc) with that of unfractionated heparin in patients having a total hip replacement

Specific inhibition of thrombin is a new method for the prevention of postoperative deep-vein thrombosis. The objective of this multicenter, randomized, double-blind study was to compare the efficacy and safety of desirudin (Revasc, CGP 39393; fifteen milligrams two times a day) with that of unfractionated heparin (5000 international units three times a day) in patients having a primary elective total hip replacement. The medications were administered subcutaneously, starting preoperatively and continuing for eight to eleven days. The primary end point was a confirmed thromboembolic event during the treatment period. The presence of deep-vein thrombosis was evaluated with bilateral venograms, which were centrally assessed by two independent radiologists. A total of 445 eligible patients were randomized: 220, to management with heparin, and 225, to management with desirudin. A per-protocol analysis of efficacy was performed for the 351 patients (79 per cent) for whom an adequate bilateral venogram had been made within eight to eleven days after the operation or who had had a proved thromboembolic event. The prevalence of confirmed deep-vein thrombosis was thirteen (7 per cent) of 174 patients who had received desirudin and forty-one (23 per cent) of 177 patients who had received heparin, a significant difference (p < 0.0001). The prevalence of proximal deep-vein thrombosis was also significantly reduced (p < 0.0001), by 79 per cent, in the group that had received desirudin (six [3 per cent] of 174 patients) compared with in the group that had received heparin (twenty-nine [16 per cent] of 177). There were no confirmed pulmonary embolisms or deaths during the period of prophylaxis. During a six-week follow-up period, pulmonary embolism was confirmed in four patients, all of whom had received heparin. There was no significant difference between the treatment groups with respect to bleeding variables or bleeding complications. These data demonstrate that a fixed dose of fifteen milligrams of desirudin, started preoperatively and administered subcutaneously twice daily for at least eight days, provided effective, safe prevention of thromboembolic complications, with no specific requirements for laboratory monitoring, in patients who had a total hip replacement.

Optimization of ascending phlebography of the leg for screening of deep vein thrombosis in thromboprophylactic trials

PURPOSE

Comparison of 2 phlebographic techniques in achieving adequacy of deep venous filling.

MATERIAL AND METHODS

Sixty consecutive patients with a clinical suspicion of deep vein thrombosis (DVT) were examined by 2 different techniques. A according to GREITZ and B according to LEA THOMAS. All deep veins were scored according to a protocol as DVT, normal or inadequate. Venous evaluability and DVT rates were compared. Bilateral phlebograms according to the A-technique from 92 asymptomatic patients in a different trial were reviewed to allow comparison with the symptomatic subjects.

RESULTS

The A-technique resulted in a significantly higher degree of overall evaluable patients compared to the B-technique, 95% vs 47%. A vein-by-vein analysis showed that the A-technique was significantly better than the B-technique in filling the gastrocnemius muscular (82% vs 38%), anterior tibial (85% vs 43%), and deep femoral (28% vs 18%) veins. No significant difference was found in the other veins. The DVT rates were 42% and 40% respectively for the A- and B-techniques. About 94% of the phlebograms in the asymptomatic patients were adequate.

CONCLUSION

The A-technique resulted in better venous opacification and would seem to be a more suitable screening method for asymptomatic persons.

Percentage of inadequate phlebograms and observer agreement in thromboprophylactic multicenter trials using standardized methodology and central assessment

This study examines inadequacy rates for phlebography in two multicenter trials for the prevention of post-operative DVT and determines inter-and intra-observer variability in evaluating phlebograms. A total of 991 (I) and 385 (II) patients underwent bilateral phlebography in two studies of thromboprophylaxis. Phlebography was performed using a standard method designed to visualize and assess all deep veins. Each vein was scored as normal, DVT or inadequate by both local and central assessment. The study showed low inadequacy rates for phlebograms of 12.2% (121/991) and 6.5% (25/385). Inter-observer agreement (local vs. central assessment) was moderate in both studies (I: 74.8%, Kappa-value 0.41; II: 82.6%, Kappa-value 0.51). Good intra-observer agreement (within the central assessment group) was observed (I:88.8%, Kappa-value 0.75). This study demonstrates low inadequacy rates for phlebograms using a standardized methodology and superior intra-observer agreement compared to inter-observer agreement and supports the importance of central assessment of phlebograms in thromboprophylactic multicenter trials to reduce observer variability.

Is colour Doppler ultrasound a sensitive screening method in diagnosing deep vein thrombosis after hip surgery?

Patients under going orthopedic surgery are at high risk of developing deep vein thrombosis. One hundred and thirty-eight consecutive patients undergoing total hip replacement or hip fracture surgery were included in this study. They were surveilled with colour Doppler ultrasound (CDU) and bilateral ascending contrast phlebography. The prevalence of proximal and distal DVT in this study was 5.8% and 20.3% respectively. CDU has a satisfactory sensitivity in patients with symptomatic deep vein thrombosis, especially in the proximal region. These results could not be confirmed in the present study of asymptomatic patients. The sensitivity was 62.5% (95% confidence interval: C.I. 24-91%) and the specificity 99.6% (C.I. 98-100%) for proximal DVT; 53.6% (C.I. 34-73%) and 98% (C.I. 96-99%) respectively for distal thrombi. the overall sensitivity was 58.1% (C.I. 39-75%) and the specificity 98% (C.I. 96-99%). The positive predictive value was 83.3% (C.I. 36-99%) and 75% (C.I. 51-91%) for proximal and distal DVT respectively. The negative predictive value was 98.9% (C.I. 98-100%) and 94.9% (C.I. 92-98%) for proximal and distal DVT respectively. The results of this study showed that even with a highly specialised and experienced investigator the sensitivity of CDU was too low to make it suitable for screening purposes in a high risk surgical population.

Colour Doppler ultrasound in diagnosing venous insufficiency. A comparison to descending phlebography

OBJECTIVE

To evaluate the technique of ultrasound colour Doppler in diagnosing venous valvular incompetence in the lower leg.

DESIGN

Prospective clinical study.

SETTING

Department of clinical physiology.

MATERIALS

44 patients (56 legs) referred with a clinical diagnosis of deep venous insufficiency.

CHIEF OUTCOME MEASURES

Colour Doppler and descending phlebography.

MAIN RESULTS

Using phlebography as a "gold standard" the accuracy of the colour Doppler technique varied between 93% and 55% for the different veins. For the superficial and deep femoral veins, the popliteal vein and the long and short saphenous veins the accuracy was between 90% and 70%. The lowest correlation was found for the deep calf veins (55-66% accuracy).

CONCLUSIONS

Colour Doppler was found to be a suitable technique for non-invasive investigation of patients with suspected venous insufficiency. Since the colour Doppler technique is non-invasive it is well suited for follow-up studies. Descending phlebography should be reserved as an adjunct technique in patients scheduled for valve reconstructive surgery.

Direct thrombin inhibition with Rec-hirudin CGP 39393 as prophylaxis of thromboembolic complications after total hip replacement

Hirudin is an anticoagulant originally extracted from the leech Hirudo medicinalis. Using recombinant DNA technology a new compound, recombinant desulphato hirudin CGP 39393 has now been produced. The aim of this study was to determine the maximum tolerated dose in patients undergoing elective hip replacement. This open safety trial represents, to our knowledge, the first experience of recombinant hirudin in orthopedic patients. In this study 48 patients undergoing primary total hip replacement were included and the safety of subcutaneous injections of 10, 15, 20 and 40 mg CGP 39393 twice daily, was evaluated. Prophylaxis was started immediately pre-operatively and continued for 8-10 days. A mandatory bilateral phlebography was performed at the end of the prophylactic treatment period and a clinical follow-up was done 6 weeks after surgery. A major bleeding event occurred in the first 3 patients receiving 40 mg CGP 39393 b.i.d. and the prophylaxis regimen at this dosage level was therefore discontinued. Median values of total blood loss and requirements of blood transfusion in the patients receiving 10-20 mg CGP 39393 were similar to those reported in previous studies on total hip replacement performed at the same centre, using other prophylactic drugs. Deep vein thrombosis (DVT) was confirmed by phlebography in 5 out of 12 patients in the 10 mg group (41.7%, 95% confidence limits [CL]: 15.2-72.3%), 1 out of 11 patients in the 15 mg group (9.1%, CL: 0.23-41.3%) and 2 out of 20 patients in the 20 mg group (10.0%, CL: 1.2-31.7%) during the prophylaxis period. CGP 39393 was safe and well tolerated, when administered as subcutaneous injections of 10-20 mg twice daily. The dose level of 40 mg CGP 39393 twice daily resulted in serious disturbance of the hemostasis in patients after hip prosthesis surgery.

Chronic groin injuries in athletes. Recommendations for treatment and rehabilitation

Chronic muscle and tendon injuries to the groin are common sports injuries. The symptoms of groin injuries are often uncharacteristic which can result in a delay in the correct and specific diagnosis being reached. The most common injury is the overuse strain resulting in chronic tendinitis of the adductor muscle/tendon units, especially the adductor longus. The rectus femoris and rectus abdominous muscles and tendons are also commonly affected. Computed tomography, magnetic resonance imaging and ultrasonography have been widely adopted to diagnose muscle/tendon injuries to the groin. Ultrasonography has been shown to be accurate and sensitive in diagnosing tendon injuries in the groin region, especially small partial ruptures of the muscle/tendon unit. Ultrasonography has the advantage of being fast, inexpensive and widely available. Normal findings are readily distinguished from pathological findings providing valuable pre-operative information, such as location and extent of the injury. The differential diagnoses are many and often difficult to reach. The most commonly overlooked differential diagnoses are chronic prostatitis and hernias. A multidisciplinary approach is valuable in many cases. The recommended treatment is well planned and gradually increased rehabilitation programme during the first stages. Surgery for acute injuries is rarely indicated. Surgery, for example tenotomy of the adductor longus, has given satisfactory results in many athletes when nonsurgical treatment has failed.

Septic arthritis of the knee: a 10-year review and long-term follow-up using a new scoring system

The case records of 64 patients with 65 episodes of infectious gonarthritis during 1979-88 were reviewed regarding epidemiological, clinical and laboratory data of possible relevance to the course and outcome of the disease. Long-term healing results were evaluated by means of a new scoring system 2-11 years after the acute disease in 46 patients. The infection was acquired by inoculation in 37% and by the hematogenous route in 55%. The major risk factors were trauma to the joint and arthrosis. Staphylococcus aureus was the causative agent in 58% and Streptococci in 15%. Treatment consisted of suction irrigation (86%) or intermittent aspiration (5%) combined with systemic antibiotic treatment. At follow-up, the pain and ache scores of the arthritic joint had decreased by 21% and 16% respectively, compared with the scores of the contralateral control joints. Anatomy and motility were reduced by 9% and 8% respectively. Age < 45 was associated with a greater score loss than in older patients. Treatment delayed by > 5 days was associated with increased loss of motility. We estimate that 79% of the patients had excellent or good long-term results following treatment of infectious arthritis of the knee. Evaluation of healing after infectious gonarthritis by use of a scoring system is quite feasible and allows comparison of different treatment regimes with improved accuracy.

The quantification of bone tissue regeneration after electromagnetic stimulation

In this study a titanium implant, the bone harvest chamber (BHC), was used to evaluate the effect of electromagnetic stimulation on osteogenesis. The BHC was inserted with a minimum of surgical trauma in the proximal tibial metaphysis in six adult lop-eared rabbits. Bone anchorage occurred after 4 weeks. After implant incorporation bone tissue was harvested at 3-week intervals with the implant in situ without killing the animal. The regenerated bone tissue was analysed by means of microradiography and densitometry. A test group and a control group each comprised six rabbits. The test group was stimulated with a 72-Hz electromagnetic field. Bone tissue was harvested from each tibia six times during the stimulation time and twice after the stimulation had been turned off. The control group had the same harvest procedure performed from one leg. Results showed that electromagnetic stimulation can maintain constant high osteogenetic activity. After the electromagnetic stimulation was turned off the osteogenetic activity diminished rapidly and osteogenesis was significantly lower than during stimulation.

Influence of indomethacin on the regeneration of cortical bone within titanium implants in rabbits

The influence of indomethacin on cortical bone regeneration was studied in bone harvest chambers made of commercially pure titanium and inserted in rabbit tibia. Newly formed bone was harvested in situ every 3 wk for 33 wk. Indomethacin (1 mg/kg body weight) was given daily as subcutaneous injections for two periods, followed by two control periods with no drug administration and the same schedule was followed for indomethacin at a dose of 4 mg/kg body weight. These indomethacin dosages did not statistically influence the cortical bone regeneration.

Ultrasonography of chronic tendon injuries in the groin

Ultrasonography was used in the diagnosis of 36 patients with chronic groin pain localized to the tendons of the rectus abdominis, rectus femoris, adductor muscles, hamstring muscles, and the gluteal muscles. Abnormal findings, such as focal sonolucent areas and discontinuity of tendon fibers, that are indicative of nonhealed partial ruptures were found in 28 patients. These findings differed clearly from the asymptomatic contralateral side, which was used for comparison. The abnormalities were located in three different sites: at the tendon insertion, within the tendon, and at the tendomuscular junction. Ten patients were treated surgically and the findings at surgery correlated well with the ultrasonographic findings of partial tendon tears: 9 were true-positive and 1 was a true-negative. Ultrasonography appears to be a valuable method in the diagnosis of chronic groin pain.

Diagnostic value of ultrasonography in partial ruptures of the Achilles tendon

We evaluated 37 patients with surgically treated Achilles tendon disorders, comparing findings of preoperative ultrasonography with findings at surgery, to investigate the reliability of ultrasonography in diagnosing partial ruptures of the Achilles tendon. Discontinuity of tendon fibers, focal sonolucencies, and localized tendon swelling were positive findings suggestive of partial ruptures. We found the use of ultrasonography to be safe and reliable, with a sensitivity of 0.94, a specificity of 1.00, and an overall accuracy of 0.95.

Partial rupture of the patellar ligament

Eighty-one patients with 91 partial ruptures of the patellar ligament verified by ultrasonography were treated conservatively with a standardized training program based on the principles of eccentric loading. The partial ruptures were quantified by measuring the length of the hypoechoic lesion using ultrasonography in longitudinal projection. The partial ruptures were then divided into three groups: Grade I (less than 10 mm), Grade II (10 to 20 mm), and Grade III (greater than 20 mm). The results after the training program were significantly better in Grade I ruptures than in Grades II and III. The overall need for surgery was 29.6%: highest in Grade III ruptures (38.5%) and lowest in Grade I ruptures (6.6%). The outcome of conservative management, as well as the need for surgery of partial ruptures of the patellar ligament, may to some extent be predicted by the use of ultrasonography.

Masseter muscle thickness measured by ultrasonography and its relation to facial morphology

The aims of this study were to evaluate ultrasonography as a method for measuring masseter muscle thickness, to quantitate the normal range of the ultrasonically measured thickness of the masseter in adults, and to test whether the variation in the thickness of the muscle is related to the variation in the facial morphology in different individuals. In 40 healthy, fully-dentate young adults, 20 men and 20 women, the masseter thickness was measured bilaterally by a real-time ultrasound imaging technique. The measurements were performed under both relaxed conditions and with maximal clenching. Standardized facial photos of the subjects were taken so that their facial morphology could be determined. The measurement error of the thickness of the masseter was found to be small, not exceeding 0.49 mm. Under relaxed conditions, the mean thickness (+/- S.D.) of the muscle in men was 9.7 (+/- 1.5) mm, and under contracted conditions, 15.1 (+/- 1.9) mm. In women, the respective measurements were 8.7 (+/- 1.6) mm and 13.0 (+/- 1.8) mm. The thickness of the masseter muscle was found to be related to the facial morphology, mainly in women, but not in men; the women with a thin masseter had a proportionally longer face. Ultrasonography was found to be a reliable and accurate method for study of the thickness of the masseter muscle. There was a large variation in the thickness of the muscle between individuals, and the thickness of the masseter was related to facial morphology in women.

Ultrasonography in the detection of partial patellar ligament ruptures (jumper's knee)

The diagnostic performance of ultrasonography (US) in the detection of partial ruptures in the proximal part of the patellar ligament (jumper's knee) was studied. A total of 81 athletes with chronic localized pain suggestive of jumper's knee underwent US examination, and 25 of these received surgical treatment. Of 25 proven partial tendon ruptures at surgery, US correctly indicated the diagnosis in all cases. A cone-shaped, poorly echogenic area exceeding 0.5 cm in length in the center of the patellar tendon in combination with its localized thickening proved to be a reliable indicator of jumper's knee. One case was a true-negative. No false-negative or false-positive case was observed. Soft-tissue radiography in 14 cases showed a localized swelling but did not detect intratendinous soft-tissue abnormalities. US is the method of choice for the evaluation of jumper's knee, as it is cheap, non-invasive, repeatable, and accurate.

Prevention of deep-vein thrombosis and pulmonary embolism after total hip replacement. Comparison of low-molecular-weight heparin and unfractionated heparin

In a prospective, randomized, double-blind study, the efficacy and safety of a low-molecular-weight heparin were compared with those of unfractionated sodium heparin (standard heparin) in 136 patients who had elective total hip replacement. The patients received subcutaneous injection of either 5000 international units of low-molecular-weight heparin once daily or 5000 international units of standard heparin three times a day. Treatment with low-molecular-weight heparin began twelve hours before the operation, and treatment with standard heparin began two hours preoperatively; both regimens were continued for ten days. Twelve days postoperatively, bilateral ascending phlebography was performed in 122 patients, sixty-three in the treatment group that received low-molecular-weight heparin and fifty-nine in the treatment group that received standard heparin. Pulmonary scintigraphy was performed in 127 patients. Deep-vein thrombosis was diagnosed in forty-four patients: nineteen (30 per cent) of the sixty-three who received low-molecular-weight heparin and twenty-five (42 per cent) of the fifty-nine who received standard heparin. All but four patients, two from each treatment group, were asymptomatic. The difference in the total rate of thrombosis in the two groups was not significant (p = 0.189). However, thrombosis occurred in the thigh in only six (10 per cent) of the patients who received low-molecular-weight heparin but in eighteen (31 per cent) of those who received standard heparin, a significant difference (p = 0.011). Pulmonary embolism was detected in twenty-seven patients: eight (12.3 per cent) of those who received low-molecular-weight heparin and nineteen (30.6 per cent) of those who received standard heparin. Only three patients had clinical signs of embolism. Pulmonary embolism was significantly more frequent in the group that received standard heparin (p = 0.016). Total loss of blood and the total amount of blood that was transfused were significantly reduced in the patients who received low-molecular-weight heparin compared with those who received standard heparin. Prophylaxis was not discontinued because of hemorrhage in any patient. The efficacy of low-molecular-weight heparin was superior to that of standard heparin in the prevention of femoral thrombosis and pulmonary embolism, although the over-all incidence of deep-vein thrombosis was not statistically different.(ABSTRACT TRUNCATED AT 400 WORDS)

Soft-tissue radiography, computed tomography, and ultrasonography of partial Achilles tendon ruptures

Ultrasonography (US) was compared with soft-tissue radiography (STR) and computed tomography (CT) for demonstration of partial Achilles tendon ruptures. Thirty-nine patients suffering from chronic localized painful Achilles tendon swelling were examined. The patients had all undergone a previous clinical examination, resulting in a suspicion of a non-healed partial tear in 62 out of the 78 tendons. STR showed unspecific tendon pathology such as thickening and diffuse tendon margins. CT resulted in a better delineation of intra- as well as extratendinous abnormalities compared to STR. Various pathologic changes were seen on CT in 54 tendons and in 29 of these, localized intratendinous hypodensities indicated partial ruptures. At US, abnormal changes were observed in 69 tendons, of which 54 had discontinuity of tendon fibers, focal hypoechoic areas, and localized swelling indicating partial ruptures. In 9 cases with surgically proven partial ruptures, US was correct in all cases, while CT was false-negative in 3. STR only showed localized swelling. It was concluded that US was a better method than STR and CT for the detection of partial ruptures and the US findings correlated well with the surgical findings.

Compression-traction radiography of lumbar segmental instability

Compression-traction radiography was used to assess movements in the sagittal plane of the lumbosacral joint in a control group of asymptomatic normal individuals and in a patient group with a symptomatic lytic spondylolisthesis. Sagittal translatory movements were found in both groups, but the amount of displacement was significantly larger (P less than 0.001) in the patient group as compared with the controls. The average displacement in the patient group, using a relative measurement technique, was 5.2%, ranging from 0.2 to 15.4%; and the corresponding values in the controls resulted in a mean of 0.8% and a range of -2.3% to 3.6%. Eighteen of the 29 patients (62%) exhibited translations of the lytic vertebra exceeding the largest displacement (greater than 3.6%) detected in the control group. The translatory movements in the patients were composed of a predominant anterior displacement in the compression view and a smaller posterior movement in the traction view. Analysis of sagittal rotation, ie, angulatory movements in the L5-S1 segment, resulted in no significant difference between the two groups. Compression-traction radiography may detect pathologic translatory movements, indicative of lumbar segmental instability.

Phlebographic findings in venous thrombosis following total hip replacement

The specific appearance of venous thrombosis following total hip replacement was analysed by reviewing 45 positive phlebograms from 122 patients participating in a concurrent trial against thromboembolism. Almost all thrombi were asymptomatic and non-occlusive. Forty-four per cent of the thrombi were exclusively confined to the calf. The muscular veins were the most common location, followed by the fibular and posterior tibial veins. Ipsilateral thrombi predominated over thrombi in the non-operated leg. Thirty-six per cent were located in the ipsilateral thigh and the major part was found in the proximal part of the femoral veins. Nearly all were related to valve cusps, free-floating and were of small size. In 20 per cent, thrombi were found in both the calf and the thigh. Neither contralateral thigh thrombi, nor pelvic thrombi were found. Of 25 patients with pulmonary embolism, all but 3 asymptomatic, 64 per cent had thigh thrombi. A multifocal location of thrombi was present but two major types of thrombosis were distinguished; calf vein thrombosis probably due to venous stasis and femoral thrombosis caused by the local surgical trauma.

Radiographic videodensitometry for quantitative monitoring of experimental bone healing

A method for non-invasive assessment of experimental bone healing in animals is described. Optimized radiographs were analysed by digital processing using a computer-based image analysis system. Values of the total mass were expressed as the equivalent mass of a simultaneously exposed aluminium roentgen-density reference. In order to assess the potential of the method, measurements were initially performed on phantoms and bone specimens. The systematic error was negligible. An excellent correlation (r = 0.999) was found between the densitometric weight (mu) and the corresponding dry weight (m) of the analysed bone samples and a calibration factor mu/m = 1.38 was established. The total random error was low, the coefficient of variation (CV) amounting to less than 5% or, if duplicate analyses were performed, less than 3%. The accuracy was not impaired when radiography was carried out with addition of water to mimic overlying soft tissue in the model. The method was applied to the assessment of callus mass longitudinally in vivo in the healing of a bone defect in the rabbit radius, yielding reproducible values (CV less than 5%) and a quantitative analysis of the healing sequence.

Stress views in the comparative assessment of spondylolytic spondylolisthesis

Patients with spondylolytic spondylolisthesis were examined in six different positions to detect segmental instability. The amount of displacement was determined on lateral spot radiographs, taken in recumbent, standing, flexion, extension, axial compression, and traction positions in each patient. An error analysis was also performed. Examination in axial compression-traction was found to be a significantly better method for detection of segmental instability compared with standing-recumbent, or flexion-extension radiographs. In addition, the compression-traction method exhibited a higher sensitivity for identification of instability (73%) than standing-recumbent (33%) or flexion-extension (20%) views. The total error in the determination was small, +/- 2.5% (95% CL), providing a careful and controlled technique was used.

Computed tomography in massive pulmonary embolism

The usefulness of computed tomography (CT) for the diagnosis of pulmonary embolism (PE) was demonstrated in two cases. Employing dynamic, contrast-enhanced CT, both direct and indirect signs of PE may be rapidly and conveniently demonstrated. Possible contraindications for therapy may be diagnosed simultaneously and follow-up examinations after therapy may be readily performed. The method serves as a good complement when PE must be verified before treatment with potent agents.