Kp. Black et al., Effects of interference fit screw length on tibial tunnel fixation for anterior cruciate ligament reconstruction, AM J SP MED, 28(6), 2000, pp. 846-849
Graft-tunnel mismatch during arthroscopically assisted anterior cruciate li
gament reconstruction using the central-third patellar tendon results in le
ss than 20 mm of bone plug remaining in the tibial tunnel. We decided to ev
aluate the strength of bone plug fixation using interference fit screws tha
t were less than 20 mm in length. Biomechanical testing was performed on 48
porcine hindquarters using 9-mm diameter interference fit screws that meas
ured 12.5, 15, and 20 mm in length. No significant difference was noted bet
ween the different-length screws for insertion torque, divergence, stiffnes
s, displacement, or load to failure. We believe, therefore, that comparable
graft fixation can be achieved in the tibial tunnel using 9-mm diameter in
terference fit screws that are less than 20 mm long, and that these shorter
screws may be useful in cases of graft-tunnel mismatch.