Alberto Grassi1, Cecilia Signorelli2, Francisco Urrizola3, Federico Raggi4, Luca Macchiarola4, Tommaso Bonanzinga5, Stefano Zaffagnini4. 1. IRCCS Istituto Ortopedico Rizzoli, Laboratorio di Biomeccanica e Innovazione Tecnologica, Bologna, Italy; IRCSS Istituto Ortopedico Rizzoli, Clinica Ortopedica e Traumatologica II, Bologna, Italy; Università di Bologna, Dipartimento Scienze Biomediche e Neuromotorie - DIBINEM, Bologna, Italy; Humanitas Clinical and Research Center, Rozzano, Milano, Italy. 2. IRCCS Istituto Ortopedico Rizzoli, Laboratorio di Biomeccanica e Innovazione Tecnologica, Bologna, Italy. Electronic address: c.signorelli@biomec.ior.it. 3. Hospital Las Higueras, Talcahuano, Concepción, Región del Bío Bío, Chile. 4. IRCCS Istituto Ortopedico Rizzoli, Laboratorio di Biomeccanica e Innovazione Tecnologica, Bologna, Italy; IRCSS Istituto Ortopedico Rizzoli, Clinica Ortopedica e Traumatologica II, Bologna, Italy; Università di Bologna, Dipartimento Scienze Biomediche e Neuromotorie - DIBINEM, Bologna, Italy. 5. Università di Bologna, Dipartimento Scienze Biomediche e Neuromotorie - DIBINEM, Bologna, Italy; Hospital Las Higueras, Talcahuano, Concepción, Región del Bío Bío, Chile; Humanitas Clinical and Research Center, Rozzano, Milano, Italy.
Abstract
BACKGROUND: Until now, there has been a lack of in vivo analysis of the correlation between bony morphological features and laxity values after an anterior cruciate ligament (ACL) injury. METHODS: Forty-two patients who underwent ACL-reconstruction were enrolled. Static laxity was evaluated as: antero-posterior displacement and internal-external rotation at 30° and 90° of flexion (AP30, AP90, IE30, IE90) and varus-valgus rotation at 0° and 30° of flexion (VV0, VV30). The pivot-shift (PS) test defined the dynamic laxity. Using magnetic resonance imaging, we evaluated the transepicondylar distance (TE), the width of the lateral and medial femoral condyles (LFCw and MFCw) and tibial plateau (LTPw and MTPw), the notch width index (NWI) and the ratio of width and height of the femoral notch (N-ratio), the ratio between the height and depth of the lateral and medial femoral condyle (LFC-ratio and MFC-ratio), the lateral and medial posterior tibial slopes (LTPs and MTPs) and the anterior subluxation of the lateral and medial tibial plateau with respect to the femoral condyle (LTPsublx and MTPsublx). RESULTS: Concerning the AP30, LTPs (P=0.047) and MTPsublx (P=0.039) were shown to be independent predictors while for the AP90 only LTPs (P=0.049) was an independent predictor. The LTPs (P=0.039) was shown to be an independent predictor for IE90 laxity, while for the VV0 test it was identified as the LFCw (P=0.007). CONCLUSIONS: A higher antero-posterior laxity at 30° and 90° of flexion was found in those with a lateral tibial slope <5.5°.
BACKGROUND: Until now, there has been a lack of in vivo analysis of the correlation between bony morphological features and laxity values after an anterior cruciate ligament (ACL) injury. METHODS: Forty-two patients who underwent ACL-reconstruction were enrolled. Static laxity was evaluated as: antero-posterior displacement and internal-external rotation at 30° and 90° of flexion (AP30, AP90, IE30, IE90) and varus-valgus rotation at 0° and 30° of flexion (VV0, VV30). The pivot-shift (PS) test defined the dynamic laxity. Using magnetic resonance imaging, we evaluated the transepicondylar distance (TE), the width of the lateral and medial femoral condyles (LFCw and MFCw) and tibial plateau (LTPw and MTPw), the notch width index (NWI) and the ratio of width and height of the femoral notch (N-ratio), the ratio between the height and depth of the lateral and medial femoral condyle (LFC-ratio and MFC-ratio), the lateral and medial posterior tibial slopes (LTPs and MTPs) and the anterior subluxation of the lateral and medial tibial plateau with respect to the femoral condyle (LTPsublx and MTPsublx). RESULTS: Concerning the AP30, LTPs (P=0.047) and MTPsublx (P=0.039) were shown to be independent predictors while for the AP90 only LTPs (P=0.049) was an independent predictor. The LTPs (P=0.039) was shown to be an independent predictor for IE90 laxity, while for the VV0 test it was identified as the LFCw (P=0.007). CONCLUSIONS: A higher antero-posterior laxity at 30° and 90° of flexion was found in those with a lateral tibial slope <5.5°.