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Background@#Knowledge of anatomy and morphometry of the patella and patellar tendon is crucial for the selection of bonepatellar tendon-bone (BTB) graft for anterior cruciate ligament reconstruction. Graft tunnel mismatch in BTB graft especially in patients with patella alta or baja can result in compromised fixation for the bone-to-bone healing. This complication can be avoided by proper templating of graft using parameters measured from magnetic resonance imaging (MRI). The study aimed to derive morphometric data from MRI and predict the suitability of BTB graft preoperatively. @*Methods@#MRI of 1,002 knees was chosen from database after applying the eligibility criteria, which included individuals in the age group of 18–50 years (both sexes) with the intact patella and patellar tendon. Individuals with pathologies of the knee joint and associated structures such as patellar fracture/dislocations, fractures of the distal femur and proximal tibia, and avulsion of the quadriceps tendon or patellar tendon were excluded. For analysis, 1.5 Tesla, proton density, and fat-suppressed sequences of sagittal and axial sections of T2-weighted MRI images were used. @*Results@#Mean age of the 1,002 patients was 35.45 years and there were 290 women and 712 men. Respective measurements were as follows: patella length, width, and thickness, 40.3 mm, 40.2 mm, and 18.6 mm, respectively; patellar tendon length, width, and insertional thickness, 45.2 mm, 27.2 mm, and 5.7 mm, respectively; Insall-Salvati ratio, 1.13; overall graft length, 90.2 mm; and effective tendon length, 26.1 mm. @*Conclusions@#A simple MRI analysis can give us valuable inputs on BTB graft morphometry. The values can also help us with the near-perfect graft harvest. The intraoperative complication of graft tunnel mismatch can be avoided by predicting the overall graft length, effective tendon length, tibial tunnel length, and patellar position using the measured parameters on MRI.
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<p><b>OBJECTIVE</b>To assess the accuracy of the clinically estimated blood loss (EBL) when compared with the actual blood loss (ABL) in replacement surgeries.</p><p><b>METHODS</b>This prospective study was done in Sri Ramachandra Medical Centre from April 2011 to April 2013. Altogether 140 patients undergoing total hip replacement or total knee replacement were included with the inclusion criteria being patients with haemoglobin higher than 100 g/ml and coagulation profile within normal limits. Exclusion criteria were intake of anti-platelet drug or anti-coagulant, bleeding disorders, thrombotic episode, and haematological disorders. There were 65 men and 75 women. In this study, the consultants were free to use any clinical method to estimate the blood loss, including counting the blood-soaked mops and gauze pieces (estimating the volume of blood carried in all the mops and gauzes), measuring blood lost to suction bottles and blood in and around the operative field. The ABL was calculated based on a modification of the Gross's formula using haematocrit values.</p><p><b>RESULTS</b>In 42 of the 140 cases, the EBL exceeded the ABL. These cases had a negative difference in blood loss (or DIFF-BL<0) and were included in the overestimation group, which accounted for 30% of the study population. Of the remaining 98 cases (70%), the ABL exceeded the EBL. Therefore they were put into the underestimation group who had a positive difference in blood loss (DIFF-BL>0). We found that when the average blood loss was small, the accuracy of estimation was high. But when the average blood loss exceeded 500 ml, the accuracy rate decreased significantly. This suggested that clinical estimation is inaccurate with the increase of blood loss.</p><p><b>CONCLUSION</b>This study has shown that using clinical estimation alone to guide blood transfusion is inadequate. In this study, 70% of patients had their blood loss underestimated, proving that surgeons often underestimate blood loss in replacement surgeries.</p>