Background

Computer-assisted navigation systems for total knee arthroplasty (TKA) were introduced to improve implantation accuracy and to optimize ligament balancing. Several comparative studies in the literature confirmed an effect on the component position and other studies could not confirm these results. For ligament balancing most studies found no significant influence on the clinical outcome using a navigation system for TKA. In the literature there were no reports of mid-term results after navigated TKA. With our study we wanted to show if the use of a navigation system for TKA will have an influence on the component's position and on the clinical results at 5-year follow up.

Background

In the literature are different data about the allogenic blood transfusion rate after total knee replacement. The common intention in orthopedic surgery is to reduce the requirement for allogenic blood transfusions by optimizing the blood management. The aim of this study is to determine the efficacy of the mechanical autotransfusion system OrthoPAT® to reduce the postoperative allogenic blood transfusion (ABT) rate.

Background: In the literature are different data about the allogenic blood transfusion rate after total knee replacement. The common intention in orthopedic surgery is to reduce the requirement for allogenic blood transfusions by optimizing the blood management. The aim of this study is to determine the efficacy of the mechanical autotransfusion system OrthoPAT (Haemonetics Corp., MA, USA) to reduce the postoperative allogenic blood transfusion rate.

Method: According to the preliminary performed power analysis we did a prospective controlled study including 104 patients which were randomized in a group A (OrthoPAT for intra- and postoperative blood salvage and retransfusion, n = 52 patients) and a control group B (no retransfusion system was used, n = 52 patients) All patients had a primary osteoarthritis of the knee and were operated on without use of a tourniquet. We implanted in all patients a cemented posterior stabilized total knee prosthesis design (LPS-Flex Mobile, Zimmer, IN, USA). In group A the autotransfusion system was used for 6 hours (intra- and postoperatively) and the collected blood was retransfused. The retransfused blood is anticoagulanted, filtered and centrifuged to separate waste products. Red cells are washed with saline and reconcentrated to a high haematocrit. The preoperative data for cardiopathy, angiopathy, preoperative anemia or anticoagulant treatment showed no significant differences for group A and B. Because of missing data we finally were able to use the results of 98 patients: 48 group A and 50 in group B. The indications for a blood transfusion were influenced by the clinical symptoms of anemia, the hemoglobin value (hemoglobin < 8.0 g/dl) and the anamnesis of cardiovascular diseases. Evaluation was done with the medical history and the pre-/postoperative hemoglobin values, postoperative blood loss and postoperative need of allogenic blood transfusion.

Results: The two groups showed no significant differences relating to the demographic data or the medical history. 16 patients (33 %) of the retransfusion group who in mean received 281 ml of salvaged blood needed allogenic blood transfusion compared with 22 patients (44 %) of the control group B (p = 0,306). The hemoglobin values of group A versus the control group showed after the donation of the salvaged blood a significant difference (p = 0,027) but no longer at the 3rd and 5th day postoperative.

Conclusions: The use of the autotransfusion system seems to reduce the postoperative allogenic blood transfusion rate but not statistical significant. At the 3rd and 5th day postoperatively no significant differences of the hemoglobin values could be stated comparing group A with group B. For us this was a clue showing that the quality of the erythrocytes after the reclamation was reduced.

Introduction: We hereby present results of controlled randomized trial of use of popliteal block for pain relief in ankle and hind foot surgery.

Materials and Methods: We have studied 47 patients over period of 9 months in 2007–08. Patients who needed ankle or hind foot procedure were selected for trial. Patients were explained about the trial and popliteal block along with leaflets at preoperative clinics. Patients were randomized on the day of surgery. A sealed envelop stating whether patient will go to block group (A) or no block group (B) was opened in the anaesthetic room before the patient was anaesthetized. Patients were evaluated for subjective pain scores at 30 min, 6hrs, 12 hrs and 24 hrs after surgery. Amount of anaelgesic required and time to first dose was documented. Popliteal blocks were given by one foot and ankle consultant and one trained fellow. The block was administered in lateral position at 0.8 mamp stimulus to detect the nerve. The data was compared statistically between group A and B.

Results: Average subjective pain scores in group A were reported to be 1.2 at 30 min, 1.23 at 6 hrs, 2.1 at 12 and 3 at 24 hrs. Where as in group B it was 1.2, 7.2, 8.1 and 4 at 30 min, 6 hrs, 12 hrs and 24 hrs respectively. There was statistically significant difference in pain scores at 6 and 12 hrs. There was no statistically significant difference in pain scores at 30 min and 24 hrs.

Conclusion: Popliteal block offers an effective way of pain relief in ankle and hind foot surgery. We believe that it may reduce amount of anaesthetic or anaelgesic drug requirement as well.

Introduction: Although bone marrow edema (BME) of the knee is a common phenomenon, physical tests to diagnose this condition have not been investigated thus far. We hypothesized that a mallet test would be useful as a diagnostic aid as well as a screening tool.

Methods: Seventy patients (36 women, 34 men) were investigated in this blinded controlled study. Group 1 consisted of patients with painful BME in the knee and group 2 of patients with a painful knee without BME. Pain provoked by a reflex mallet was assessed for each quadrant on a visual analog scale (VAS).

Results: The VAS score was 3.7 (±2.1 cm) for quadrants affected by BME (group 1), 1.59 (±1.44) in non-affected quadrants of the knee affected by BME (group 1) and, 0.85 (±0.85) in painful knees without BME (group 2). Pain on the tapping test was significantly correlated with the presence of BME in the affected knee (p< 0.0001) as well as the affected quadrant (p< 0.0001 for the medial femoral condyle and the medial femoral plateau).

Conclusion: The tapping test is a good screening instrument to diagnose BME in the knee.