Hua-yang Huang1, Yong-liang Ou2, Ping-yue Li1, Tao Zhang1, Shuai Chen2, Hong-yuan Shen1, Qing Wang1, Xiao-fei Zheng3. 1. Department of Orthopaedics, General Hospital of Guangzhou Military Command of PLA, Guangdong 510010, China. 2. Department of Orthopaedics, General Hospital of Guangzhou Military Command of PLA, Guangdong 510010, China; Bioenginering Laboratory, Department of Orthopaedics, General Hospital of Guangzhou Military Command of PLA, Guangdong 510010, China. 3. Department of Orthopaedics, General Hospital of Guangzhou Military Command of PLA, Guangdong 510010, China. Electronic address: doctorzhengxiaofei@hotmail.com.
Abstract
BACKGROUND: Single-tunnel double-bundle (STDB) anterior cruciate ligament (ACL) reconstruction can restore biomechanical function and anatomic structure, but existing methods of graft fixation are not adequate. The aims of this study are to examine knee biomechanics after STDB reconstruction using a unique expandable interference screw for fixation. METHODS: The biomechanical parameters of six pairs of human cadaveric knee specimens were measured with the ACL intact, after ACL removal, and after STDB reconstruction using the interference screw or single-tunnel single-bundle (STSB) reconstruction. Anterior tibial translation under 134 N anterior tibial load in a neutral position as well as in 15° and 30° internal and external knee rotation and the internal tibial rotation angle under the rotatory load (5 N·m internal tibial rotation) were measured. RESULTS: Anterior tibial translations at each degree of knee flexion in the STDB group were significantly less than in the STSB group (all, P<0.05). The internal rotation angles in the STSB group at five flexion angles were significantly higher than in the ACL intact group, whereas there were significantly less than those of the ACL absent group (P<0.05). Under rotatory loads in the neutral position, the tibial internal rotation angles of the STDB group were significantly lower than in the STSB group at all flexion angles (all, P<0.05). CONCLUSIONS: STDB ACL reconstruction with the expandable interference screw provides better anteroposterior and rotational stability than STSB reconstruction. CLINICAL RELEVANCE: The technique provides the advantages of double-bundle reconstruction using a single-tunnel technique.
BACKGROUND: Single-tunnel double-bundle (STDB) anterior cruciate ligament (ACL) reconstruction can restore biomechanical function and anatomic structure, but existing methods of graft fixation are not adequate. The aims of this study are to examine knee biomechanics after STDB reconstruction using a unique expandable interference screw for fixation. METHODS: The biomechanical parameters of six pairs of human cadaveric knee specimens were measured with the ACL intact, after ACL removal, and after STDB reconstruction using the interference screw or single-tunnel single-bundle (STSB) reconstruction. Anterior tibial translation under 134 N anterior tibial load in a neutral position as well as in 15° and 30° internal and external knee rotation and the internal tibial rotation angle under the rotatory load (5 N·m internal tibial rotation) were measured. RESULTS: Anterior tibial translations at each degree of knee flexion in the STDB group were significantly less than in the STSB group (all, P<0.05). The internal rotation angles in the STSB group at five flexion angles were significantly higher than in the ACL intact group, whereas there were significantly less than those of the ACL absent group (P<0.05). Under rotatory loads in the neutral position, the tibial internal rotation angles of the STDB group were significantly lower than in the STSB group at all flexion angles (all, P<0.05). CONCLUSIONS: STDB ACL reconstruction with the expandable interference screw provides better anteroposterior and rotational stability than STSB reconstruction. CLINICAL RELEVANCE: The technique provides the advantages of double-bundle reconstruction using a single-tunnel technique.