The anterior pelvic plane (APP) is used as a reference in various pelvic surgeries in orthopaedics. Current methods for identifying the APP are limited in accuracy and efficiency. A quick and accurate method for registering the pelvis orientation can be very useful. Previously, we have introduced a Tracked C-arm (TC-arm) system for use with any C-arm fluoroscopy for producing spatially calibrated imaging views. This system has been tried for estimating the APP. Early results, however, has shown limited repeatability in identifying the anterior superior iliac spine (ASIS) landmarks. This study improves the previous algorithms for a robust registration of the APP. A Sawbone pelvis was used, and its APP was marked by radio-dense ball-bearings. In the new addition, the TC-arm allowed segmenting the ASIS in an interactive user-interface by taking guidance from a reference line tangential to the ipsilateral pubic tubercle for marking the most anterior point on the iliac-crest. The imaging and analysis was repeated 10 times. The results were compared to reconstruction of the fiducial markers placed on the true APP. Accuracy of 1.4° and 4.4° were found for registering the pelvic tilt and rotation, correspondingly. The overall accuracy and precision of registration of the APP were 4.7° and 0.82°, correspondingly. The new method showed 7.5 times improvement in repeatability of measuring the pelvic tilt (SD<0.4°) compared to the previous fluoroscopic methods. This technique addresses an important challenge in estimation of the pelvic bone which is crucial for reliable device placement and producing standard radiographic views in surgery.
Recovery after femur fractures is slow, despite rapid bone union. Causes of disability require investigation. Forty patients with isolated, diaphyseal femur fractures treated with antegrade locked intramedullary nailing were prospectively studied. Functional outcome was measured using the Western Ontario – McMaster University Osteoarthritis Index (WOMAC) and Short Musculoskeletal Functional Assessment (SMFA). Pain scores from the groin, buttock, thigh, and knee six months following the injury were correlated with functional outcome. Severity of pain was highest at the knee. Both knee and thigh pain had strong correlations with functional outcome measures following diaphyseal femur fractures. Further investigation into post-traumatic pain is warranted. This study was performed to compare pain at the knee, thigh, buttock and groin with functional outcome scores 6 months following femur fractures. Pain at the knee and thigh correlated with functional outcome measures. Many patients with femoral fractures have prolonged disability. Knee pain is common, severe, and correlates with functional outcome. Forty skeletally-mature patients with diaphyseal femoral fractures treated with locked antegrade intramedullary nails were prospectively enrolled. Exclusion criteria included polytrauma, ipsilateral injuries, metaphyseal extension, and pathologic fractures. Functional outcomes were assessed using the Western Ontario-McMaster University Osteoarthritis Index (WOMAC) and the Short Musculoskeletal Function Assessment (SMFA). Patients were instructed to record pain in the groin, buttock, thigh or knee of the fractured extremity on a 10-point visual analog scale. Patients reported more pain at the knee (3.7 ± 3.1), compared to the thigh (2.5 ± 2.7), buttock (1.7 ± 2.7), and groin (1.0 ± 1.7) (p=0.003). Pain and functional outcomes were plotted on scatter graphs and correlations performed using the Spearman rank test. Strongest correlations were noted between knee pain and WOMAC pain (ρ=0.748, p<
0.001), function (ρ=0.701, p<
0.001), and SMFA (ρ=0.733, p<
0.001); and between thigh pain and WOMAC pain (ρ=0.705, p<
0.001), stiffness (ρ=0.707, p<
0.001), function (ρ=0.731, p<
0.001), and SMFA (ρ=0.723, p<
0.001). Weaker correlations were noted between groin and buttock pain and functional outcomes. Knee pain is common and severe after femur fractures. Knee and thigh pain correlate with functional outcomes. Further investigation should be directed to this common problem.
