TY - JOUR
T1 - MCL internal brace does not fully recapitulate normal MCL function in valgus stress
AU - Tompkins, Marc A.
AU - Freeman, Andrew L.
AU - Hursh, Elliot
AU - Bechtold, Joan E.
N1 - Publisher Copyright:
© 2023, The Author(s) under exclusive licence to European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).
PY - 2023/9
Y1 - 2023/9
N2 - Purpose: The null hypothesis is that there would be no difference in medial gapping under valgus load between the intact MCL and the ruptured MCL with an internal brace in place. Methods: Eight pairs of cadaver knees were used (16 knees). Alternating sides, one knee from each pair was used for one of two “internal brace” constructs. The constructs involved different methods of fixation for securing FiberTape (Arthrex, Naples, FL) to both the femur and tibia in an effort to brace the MCL. The knees were then subjected to valgus stress by applying 10 N m of torque with the knee at 20 degrees of flexion. The amount of medial joint space opening was measured on radiographs. The stress testing was conducted with three MCL states: intact, grade 2 tear, and grade 3 tear. Results: In the Construct I specimens, gapping increased from 0.7 mm with the MCL intact to 1.1 mm with grade 2 tearing (p < 0.01), and to 1.3 mm with grade 3 tearing (p < 0.01). In the Construct II specimens, gapping increased from 0.7 mm with the MCL intact to 1.0 mm with grade 2 tearing (p < 0.01), and to 1.1 mm with grade 3 tearing (n.s.). Construct I specimens failed primarily at the femoral attachment. All Construct II specimens survived the valgus stress testing. Conclusion: Construct I did not maintain tension. Construct II did maintain tension during application of valgus load, but did not restore valgus opening to the intact state. It is important for clinicians who are considering using this commercially available technique to be aware of how the construct performs under valgus stress testing compared to the intact MCL.
AB - Purpose: The null hypothesis is that there would be no difference in medial gapping under valgus load between the intact MCL and the ruptured MCL with an internal brace in place. Methods: Eight pairs of cadaver knees were used (16 knees). Alternating sides, one knee from each pair was used for one of two “internal brace” constructs. The constructs involved different methods of fixation for securing FiberTape (Arthrex, Naples, FL) to both the femur and tibia in an effort to brace the MCL. The knees were then subjected to valgus stress by applying 10 N m of torque with the knee at 20 degrees of flexion. The amount of medial joint space opening was measured on radiographs. The stress testing was conducted with three MCL states: intact, grade 2 tear, and grade 3 tear. Results: In the Construct I specimens, gapping increased from 0.7 mm with the MCL intact to 1.1 mm with grade 2 tearing (p < 0.01), and to 1.3 mm with grade 3 tearing (p < 0.01). In the Construct II specimens, gapping increased from 0.7 mm with the MCL intact to 1.0 mm with grade 2 tearing (p < 0.01), and to 1.1 mm with grade 3 tearing (n.s.). Construct I specimens failed primarily at the femoral attachment. All Construct II specimens survived the valgus stress testing. Conclusion: Construct I did not maintain tension. Construct II did maintain tension during application of valgus load, but did not restore valgus opening to the intact state. It is important for clinicians who are considering using this commercially available technique to be aware of how the construct performs under valgus stress testing compared to the intact MCL.
KW - Internal brace
KW - MCL
KW - Valgus stress
UR - http://www.scopus.com/inward/record.url?scp=85159320930&partnerID=8YFLogxK
U2 - 10.1007/s00167-023-07438-4
DO - 10.1007/s00167-023-07438-4
M3 - Article
C2 - 37171603
AN - SCOPUS:85159320930
SN - 0942-2056
VL - 31
SP - 3604
EP - 3610
JO - Knee Surgery, Sports Traumatology, Arthroscopy
JF - Knee Surgery, Sports Traumatology, Arthroscopy
IS - 9
ER -