RESUMO
Objective: Patients who receive total knee arthroplasty, which is a procedure that typically results in large amount of blood loss, have a higher probability of experiencing hypovolemic shock which can result in life threatening complications for the patient. Based on study and practice, the amount of blood loss can vary significantly. Currently, there are no other studies related to hypovolemic shock after total knee arthroplasty. The objective of this research is to study protective measures against hypovolemic shock after severe loss of blood which can occur after total knee artrhoplasty surgery and to ensure the safety of the patient post total knee arthroplasty surgery. Methods: This is a retrospective study. Study subjects were patients who received total knee arthroplasty surgery at Jainad Narendra Hospital from October 1, 2007 through March 31, 2010. The total number of study subjects enrolled was 124 patients and 139 subjects. The study focused on the occurrence of hypovolemic shock after knee artrhoplasty surgery. Hypovolemic shock is a state of decreased blood volume characterized by a blood pressure lower than 80/60 mmHg and heart rate of over 100 beats per minute. Results: Out of the 139 subjects, 20 subjects experienced hypovolemic shock after total knee arthroplasty surgery and 119 subjects did not. Differences in the amount of blood given to patients who experienced hypovolemic shock and those who did not experience hypovolemic shock did not indicate any statistical significance with a p-value <0.05. Differences in hematocrit levels pre-operation and two hours post-operation, surgical time, and amount of blood loss post-operation did not indicate any statistical significance with p-value < 0.05 when comparing patients who experienced hypovolemic shock and those that did not after total knee arthroplasty surgery. Conclusion: Total knee arthroplasty surgery can cause severe blood loss that can lead to hypovolemic shock, which can cause life threatening complications for the patient. Therefore, it is critical to maintain proper care and close observation for post-surgical patients who received the procedure 4 hours prior.
RESUMO
The study was aimed at comparing the ultimate load bearing capabilities between normal patellar tendons (control group) and tendons after central one-third removal (removal group). Eleven fresh Thai cadavers provided study specimens. The average age of the cadavers was 24.86 +/- 7.13 years. Five tendons were used as control specimens and another six tendons underwent central one-third removal. The Instron 5583 testing machine and Cooper's technique of measurements were used to test the ultimate load. Rate of elongation of tendon was set at 500 mm/sec. The results showed that the removal group cross-sectional area was 48.67 mm2 or 49.64 per cent of the control group (98.04 mm2). The mean ultimate load of the control group was 4,365.59 N. The mean ultimate load of the removal group was 2,226.58 N or about 51 per cent. The energy level to breaking point in the control group was 72.17 J and 32.58 (45.14%) in the removal group. The average width of the central one-third portion was measured at 8.68 +/- 0.56 cm. Generally in a clinical situation, when the ultimate load is reduced to about half in the donor knee, care must be taken before allowing full weight to bear. Caution should also be emphasized in cases where a routinely 10 mm wide graft has been taken, as the donor tendon may be weakened by more than half and may rupture prematurely.