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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Adult, Aged, Aged, 80 and over, Anterior Cruciate Ligament Reconstruction, Bone Wires, Cadaver, Female, Femur, Humans, Knee Joint, Male, Middle Aged, Range of Motion, Articular.
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Is knee flexion angle more important than guidewire type in preventing posterior femoral cortex blowout : a cadaveric study? Context: This study compared femoral intraosseous "tunnel" length and distance from the posterior femoral cortex (PFC) when straight and flexible guidewires were drilled through an accessory anteromedial portal at 90° and 120° knee flexion. We had 2 study hypotheses: (1) 120° knee flexion would create longer femoral intraosseous tunnels than 90° knee flexion regardless of guidewire type and (2) 120° knee flexion would display a more consistent PFC blowout safety margin than 90° knee flexion regardless of guidewire type. Straight and flexible guidewires were drilled at 90° and 120° flexion in 8 cadaveric knees. Guidewire intraosseous length and distance from the PFC were measured at both knee flexion angles. Two-way analysis of variance (guidewire type, knee flexion angle) and a Fisher exact test were used to compare group differences. Guidewire exit points at 120° knee flexion were located farther from the PFC than at 90° knee flexion regardless of whether flexible guidewires (19.0 ± 5.3 mm v 12.6 ± 3.3 mm) or straight guidewires (12.9 ± 4.5 mm v 5.0 ± 3.3 mm) were used (P < .0001). Straight guidewires drilled at 90° knee flexion were within 3 mm of the PFC in 4 of 8 specimens (50%) compared with 0 of 8 at 120° knee flexion (P = .038). Intraosseous guidewire length was greater at 120° knee flexion regardless of whether straight or flexible guidewires were used (P = .04).
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Flexible guidewires and a 120° knee flexion angle both decrease the likelihood of PFC blowout. A 120° knee flexion angle is more important to femoral tunnel length than guidewire type. Use of 120° knee flexion even when drilling flexible guidewires increases the safety margin needed to prevent PFC blowout. Final Decision: yes