Lasse J. Lapidus

Prolonged thromboprophylaxis with dalteparin after surgical treatment of achilles tendon rupture: a randomized, placebo-controlled study.

Objectives: Prophylaxis against thromboembolic complications has become routine after major orthopedic surgery. In contrast, it remains an issue for debate whether prophylaxis after minor surgery and immobilization is necessary, even though these treatments are well-known risk factors for deep-vein thrombosis (DVT). The objective of this study was to evaluate the efficacy of dalteparin during lower-limb immobilization after surgical treatment of Achilles tendon rupture. Design Setting, and Patients: Randomized, placebo-controlled, double-blind study of 105 consecutive patients surgically treated for Achilles tendon rupture in a trauma hospital. DVT screening with color duplex sonography was conducted 3 weeks and 6 weeks after surgery. All DVTs were confirmed with phlebography. Intervention was placebo or dalteparin (5000 U) given subcutaneously once daily for 6 weeks postoperatively. Main Outcome Measure: DVT incidence. Results: Primary endpoint analysis was available for 91 patients. DVT was diagnosed in 16 of 47 patients (34%) in the dalteparin group and in 16 of 44 patients (36%) in the placebo group. These figures are not significantly different (P = 0.8). Proximal DVT was diagnosed in 1 patient (2%) in the dalteparin group and in 3 patients (6%) in the placebo group (P = 0.6). No pulmonary emboli or major bleeding occurred in either of the groups. Conclusions: DVT is common after surgical treatment of Achilles tendon rupture, and therefore effective thromboprophylaxis is desirable. In our study, thromboprophylaxis with dalteparin, however, does not affect the incidence of DVT during immobilization after Achilles tendon rupture surgery. Long-term effects of immobilization, such as the risk for postthrombotic syndrome, need to be investigated further.

Prolonged thromboprophylaxis with Dalteparin during immobilization after ankle fracture surgery A randomized placebo-controlled, double-blind study

Background Skeletal trauma and immobilization are well-known risk factors for deep vein thrombosis (DVT) and pulmonary embolism (PE). While prophylaxis against thromboembolic complications has become routine after major orthopedic surgery, whether or not prophylaxis after minor surgery and lower limb immobilization is necessary is still under debate. Methods In a double-blind, placebo-controlled study, 272 consecutive patients were randomized to receive either thromboprophylaxis with Dalteparin (n = 136) or placebo (n = 136) for 5 weeks after ankle fracture surgery. All patients received 1 week of initial treatment with Dalteparin before randomization. A unilateral phlebography was performed when the cast was removed. Results The overall incidence of DVT was 21% (95% CI: 13–29%) in the Dalteparin group and 28% (CI: 19– 37%) in the placebo group (risk ratio = 0.8, CI: 0.6–1.1; p = 0.3). The incidence of proximal DVTs was 4% and 3%, respectively. No major bleeding occurred. Interpretation We found no significant difference in the incidence of DVT between the 2 treatment groups and our results do not support prolonged thromboprophylaxis. The overall incidence of DVT was high, reflecting the potential risk of PE and post-thrombotic syndrome after ankle fracture surgery. Most of the DVTs were asymptomatic, however, and were located in distal veins.

Dislocation of hemiarthroplasty after femoral neck fracture: Better outcome after the anterolateral approach in a prospective cohort study on 739 consecutive hips

Background and purpose Hip replacement using a hemiarthroplasty is a common surgical procedure in elderly patients with fractures of the femoral neck. The optimal surgical approach regarding the risk of dislocation is controversial. We analyzed factors influencing the stability of the hemiarthroplasty, with special regard to the surgical approach. Patients and methods We studied 720 consecutive patients on whom 739 hemiarthroplasties were performed between 1996 and 2003, either as a primary operation for a displaced fracture of the femoral neck or as a secondary procedure after failed internal fixation of a fracture of the femoral neck. Logistic regression analyses were performed in order to evaluate factors associated with prosthetic dislocation. Results The multivariate regression analysis showed that the posterolateral approach was the only factor associated with a significantly increased risk of dislocation: OR 3.9 (CI: 1.6–10) for the posterolateral approach with posterior repair and OR 6.9 (CI: 2.6–19) for the posterolateral approach without posterior repair. Age, sex, indication for surgery, the surgeons experience, and type of HA had no statistically significant effect on the dislocation rate. Interpretation Compared to the anterolateral approach, the posterolateral approach was associated with a significantly increased risk of dislocation in patients with femoral neck fractures treated with HA. A posterior repair appears to reduce the rate of dislocation, although not to the same low level as in patients operated using the anterolateral approach.

Dislocation of total hip replacement in patients with fractures of the femoral neck: A prospective cohort study of 713 consecutive hips

Background Total hip replacement is increasingly used in active, relatively healthy elderly patients with fractures of the femoral neck. Dislocation of the prosthesis is a severe complication, and there is still controversy regarding the optimal surgical approach and its influence on stability. We analyzed factors influencing the stability of the total hip replacement, paying special attention to the surgical approach. Patients and methods We included 713 consecutive hips in a series of 698 patients (573 females) who had undergone a primary total hip replacement (n = 311) for a non-pathological, displaced femoral neck fracture (Garden III or IV) or a secondary total hip replacement (n = 402) due to a fracture-healing complication after a femoral neck fracture. We used Cox regression to evaluate factors associated with prosthetic dislocation after the operation. Age, sex, indication for surgery, the surgeon’s experience, femoral head size, and surgical approach were tested as independent factors in the model. Results The overall dislocation rate was 6%. The anterolateral surgical approach was associated with a lower risk of dislocation than the posterolateral approach with or without posterior repair (2%, 12%, and 14%, respectively (p < 0.001)). The posterolateral approach was the only factor associated with a significantly increased risk of dislocation, with a hazards ratio (HR) of 6 (2–14) for the posterolateral approach with posterior repair and of 6 (2–16) without posterior repair. Interpretation In order to minimize the risk of dislocation, we recommend the use of the anterolateral approach for total hip replacement in patients with femoral neck fractures.

High sensitivity with color duplex sonography in thrombosis screening after ankle fracture surgery

Summary.  Background: Phlebography is regarded as the reference standard for diagnosing asymptomatic deep vein thrombosis (DVT) in studies of thromboprophylaxis. However, technical advances with noninvasive color duplex sonography (CDS) have made this procedure an interesting alternative. Objectives: The objective of the present prospective study was to compare the sensitivity and specificity of CDS with those of phlebography. Patients: The first 180 consecutive patients included in a larger randomized trial for prolonged thromboprophylaxis were subject to unilateral CDS and to phlebography after ankle fracture surgery. The patients were examined 6 weeks after surgery, all examinations being evaluated blindly. After patient drop outs and exclusions, 144 patients were left for analysis. Results: Phlebography and CDS examinations were inconclusive or were not completed for 19% of these patients (28/144). DVT was diagnosed by phlebography in 21% (24/116) of the remaining patients. Most of the thrombi were isolated calf DVTs (18/24). In contrast, DVT was diagnosed by CDS in 31% of these patients (36/116): only one case diagnosed by phlebography was missed by CDS. The specificity of CDS is thus 86% and its sensitivity is 96%. The positive predictive value is 64%, and the negative predictive value is 99%. Conclusions: CDS is a safe method for detecting asymptomatic distal DVT. It has a high sensitivity and high negative predictive value, which means that the method is highly reliable to rule out DVT. Our results indicate that CDS could be considered as an alternative method for DVT screening.

Unipolar versus bipolar Exeter hip hemiarthroplasty: a prospective cohort study on 830 consecutive hips in patients with femoral neck fractures

BackgroundHip replacement using a hemiarthroplasty (HA) is a common surgical procedure in elderly patients with fractures of the femoral neck. Data from the Swedish Hip Arthroplasty Register suggest that there is a higher risk for revision surgery with the bipolar HA compared with the unipolar HA.Purpose In this study we analysed the reoperation and the dislocation rates for Exeter HAs in patients with a displaced femoral neck fracture, comparing the unipolar and bipolar prosthetic designs. Additionally, we compared the outcome for HAs performed as a primary intervention with those performed secondary to failed internal fixation.MethodsWe studied 830 consecutive Exeter HAs (427 unipolar and 403 bipolar) performed either as a primary operation for a displaced fracture of the femoral neck or as a secondary procedure after failed internal fixation of a fracture of the femoral neck. Cox regression analyses were performed to evaluate factors associated with reoperation and prosthetic dislocation. Age, gender, the surgeon’s experience, indication for surgery (primary or secondary) and type of HA (unipolar or bipolar) were tested as independent variables in the model.ResultsThe prosthetic design (uni- or bipolar) had no influence on the risk for reoperation or dislocation, nor had the age, gender or the surgeon’s experience. The secondary HAs were associated with a significantly increased risk for reoperation (HR 2.6, CI 1.5–4.5) or dislocation (HR 3.3, CI 1.4–7.3) compared to the primary HAs. We found no difference in the risk for reoperation or dislocation when comparing Exeter unipolar and bipolar HAs, but special attention is called for to reduce the risk of prosthesis dislocation and reoperation after a secondary HA.

Asymptomatic deep venous thrombosis is associated with a low risk of post-thrombotic syndrome.

UNLABELLED Post-thrombotic syndrome (PTS) is a well-recognized condition that develops after symptomatic deep venous thrombosis, but the clinical significance and late complications of asymptomatic deep venous thrombosis (ADVT) are unclear. OBJECTIVE To determine whether ADVT following minor surgery affects venous function and contributes to the later development of PTS. PATIENTS/METHODS The study included 83 patients operated on for Achilles tendon rupture; 38 patients with postoperative ADVT and 45 patients without (control group). The follow-up examinations five years after the operation comprised computerised strain-gauge plethysmography, colour duplex ultrasonography, clinical scoring of venous disease, and quality of life (QOL). RESULTS Villalta scores, CEAP classification and QOL did not differ between groups. PTS (=Villalta score > or =5) was found in three ADVT patients (8%) and in two controls (4%). Ultrasonography revealed post-thrombotic changes in 55% of ADVT patients and in none of the controls. Deep venous reflux occurred in 22 ADVT patients and in three controls (P<0.001). There was no difference between groups in plethysmographic variables, demonstrating that the ultrasonographic abnormalities were of negligible haemodynamic significance. CONCLUSIONS PTS is not a common sequel to ADVT after minor surgery. Although more than 50% of patients with ADVT developed post-thrombotic changes according to ultrasound, these changes did not result in haemodynamically significant venous dysfunction.

The vertical hip fracture - a treatment challenge. A cohort study with an up to 9 year follow-up of 137 consecutive hips treated with sliding hip screw and antirotation screw.

BackgroundFemoral neck fractures with a vertical orientation have been associated with an increased risk for failure as they are both axial and rotational unstable and experience increased shear forces compared to the conventional and more horizontally oriented femoral neck fractures. The purpose of this study was to analyse outcome and risk factors for reoperation of these uncommon fractures.MethodsA cohort study with a consecutive series of 137 hips suffering from a vertical hip fracture, treated with one method: a sliding hips screw with plate and an antirotation screw. Median follow-up time was 4.8 years. Reoperation data was validated against the National Board of Health and Welfare’s national registry using the unique Swedish personal identification number.ResultsThe total reoperation rate was 18%. After multivariable Logistic regression analysis adjusting for possible confounding factors there was an increased risk for reoperation for displaced fractures (22%) compared to undisplaced fractures (3%), and for fractures with poor implant position (38%) compared to fractures with adequate implant position (15%).ConclusionsThe reoperation rate was high, and special attention should be given to achieve an appropriate position of the implant.

Direction of hip arthroplasty dislocation in patients with femoral neck fractures

In order to prevent hip arthroplasty dislocations, information regarding the direction of the dislocation is important for accurate implant positioning and for optimising the postoperative regimens in relation to the surgical approach used. The aim of this study was to analyse the influence of the surgical approach on the direction of the dislocation in patients treated by a hemiarthroplasty (HA) or total hip arthroplasty (THA) after a femoral neck fracture. Fracture patients have a high risk for dislocations, and this issue has not been previously studied in a selected group of patients with a femoral neck fracture. We analysed the radiographs of the primary dislocation in 74 patients who had sustained a dislocation of their HA (n = 42) or THA (n = 32). In 42 patients an anterolateral (AL) surgical approach was used and in 32 a posterolateral (PL). The surgical approach significantly influenced the direction of dislocation in patients treated with HA (p < 0.001), while no such correlation was found after THA (p = 0.388). For THA patients there was a correlation between the mean angle of anteversion of the acetabular component and the direction of dislocation when comparing patients with anterior and posterior dislocations (p = 0.027). These results suggest that the surgical approach of a HA has an influence on the direction of dislocation, in contrast to THA where the position of the acetabular component seems to be of importance for the direction of dislocation in patients with femoral neck fractures.

Internal fixation of garden I and II femoral neck fractures: posterior tilt did not influence the reoperation rate in 382 consecutive hips followed for a minimum of 5 years.

Objective: To analyze factors influencing the reoperation rate due to fracture healing complications after internal fixation of Garden I and II femoral neck fractures with special reference to a new validated method assessing the preoperative posterior tilt on lateral radiographs. Design: Prospective cohort study. Setting: Level II trauma center. Patients: A consecutive cohort of 382 hips in 379 patients who underwent internal fixation for a Garden I or II femoral neck fracture. Intervention: The posterior tilt in preoperative radiographs was analyzed with a new validated method. A Cox regression analysis was used to evaluate factors associated with reoperation due to fracture healing complications. Age, gender, cognitive function, ASA classification, time to surgery, and the posterior tilt were tested as independent factors in the model. Main Outcome Measures: Reoperation rate due to fracture healing complications with a minimal follow-up of 5 years. Reoperation data were validated against the National Board of Health and Welfares national registry using unique Swedish personal identification numbers. Results: The overall reoperation rate was 19% (72 of 382 hips) and the reoperation rate due to fracture healing complications was 12% (45 of 382 hips). The posterior tilt had no influence on the risk for reoperation due to fracture healing complication, nor had the age, gender, cognitive function, ASA classification, or the time to surgery. Conclusions: Preoperative posterior tilt measurement on lateral radiographs cannot be used as a discriminator for fracture healing complications in Garden I and II femoral neck fractures. Level of Evidence: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.