Comparison of single- and double-bundle anterior cruciate ligament reconstructions in restoration of knee kinematics and anterior cruciate ligament forces.
BACKGROUND
Anterior cruciate ligament (ACL) deficiency alters 6 degrees of freedom knee kinematics, yet only anterior translation and internal rotation have been the primary measures in previous studies.


OBJECTIVE
To compare the 6 degrees of freedom knee kinematics and the graft forces after single- and double-bundle ACL reconstructions under various external loading conditions.


METHODS
Controlled laboratory study.


METHODS
Ten human cadaveric knees were tested with a robotic testing system under 4 conditions: intact, ACL deficient, single-bundle reconstructed with a quadrupled hamstring tendon graft, and double-bundle reconstructed with 2 looped hamstring tendon grafts. Knee kinematics and forces of the ACL or ACL graft in each knee were measured under 3 loading conditions: an anterior tibial load of 134 N, a simulated quadriceps muscle load of 400 N, and combined tibial torques (10 N.m valgus and 5 N.m internal tibial torques) at 0 degrees , 15 degrees , 30 degrees , 60 degrees , and 90 degrees of knee flexion.


RESULTS
The double-bundle reconstruction restored the anterior and medial laxities closer to the intact knee than the single-bundle reconstruction. However, the internal rotation of the tibia under the simulated quadriceps muscle load was significantly decreased when compared with the intact knee after both reconstructions, more so after double-bundle reconstruction (P < .05). The entire graft force of the double-bundle reconstruction was more similar to that of the intact ACL than that of the single-bundle reconstruction. However, the posterolateral bundle graft in the double-bundle reconstructed knee was overloaded as compared with the intact posterolateral bundle.


CONCLUSIONS
The double-bundle reconstruction can better restore the normal anterior-posterior and medial-lateral laxities than the single-bundle reconstruction can, but an overloading of the posterolateral bundle graft can occur in a double-bundle reconstructed knee.


CONCLUSIONS
Both single-bundle and double-bundle techniques cannot restore the rotational laxities and the ACL force distributions of the intact knee.
Seon
Jong Keun
JK
Bioengineering Laboratory, Massachusetts General Hospital / Harvard Medical School, 55 Fruit Street, GRJ 1215, Boston, MA 02114, USA.
Gadikota
Hemanth R
HR
Wu
Jia-Lin
JL
Sutton
Karen
K
Gill
Thomas J
TJ
Li
Guoan
G
D016118:Anterior Cruciate Ligament / Q000601:surgery*; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000601:surgery; D007717:Knee / Q000502:physiology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures; D019651:Plastic Surgery Procedures; D012399:Rotation; D013710:Tendons / Q000601:surgery; D013977:Tibia / Q000601:surgery
Am J Sports Med. 2007 Feb;35(2):228-34
17099239
Am J Sports Med. 2008 Jun;36(6):1087-93
18310312
Am J Sports Med. 2010 Mar;38(3):558-63
20044500
Am J Sports Med. 2008 Jul;36(7):1263-74
18354141
J Orthop Res. 1997 Mar;15(2):285-93
9167633
Am J Sports Med. 2005 Feb;33(2):240-6
15701610
Arthroscopy. 2006 Mar;22(3):240-51
16517306
Knee Surg Sports Traumatol Arthrosc. 2007 Jun;15(6):720-8
17235620
J Orthop Res. 2009 Jul;27(7):879-84
19117065
J Bone Joint Surg Am. 2008 Nov;90 Suppl 4:67-74
18984719
Am J Sports Med. 2008 Jan;36(1):73-9
18166678
Arthroscopy. 2001 Sep;17(7):708-16
11536089
Am J Sports Med. 2008 Apr;36(4):678-85
18296542
Am J Sports Med. 2008 Jul;36(7):1414-21
18508977
Arthroscopy. 2007 Jun;23(6):618-28
17560476
Am J Sports Med. 2004 Jun;32(4):975-83
15150046
J Bone Joint Surg Am. 2009 Jan;91(1):107-18
19122085
Clin Orthop Relat Res. 2007 Jan;454:100-7
17091015
Int Orthop. 2009 Apr;33(2):425-9
18324401
J Bone Joint Surg Am. 2006 Aug;88(8):1826-34
16882908
Knee Surg Sports Traumatol Arthrosc. 2008 Mar;16(3):232-8
18193194
Clin Orthop Relat Res. 2007 Jan;454:66-73
17091011
Am J Sports Med. 2009 May;37(5):962-9
19261901
Arthroscopy. 2008 Feb;24(2):137-45
18237696
Am J Sports Med. 2007 Mar;35(3):395-403
17218659
Am J Sports Med. 2004 Dec;32(8):1825-32
15572308
Clin Orthop Relat Res. 2006 Jan;442:39-44
16394737
Knee Surg Sports Traumatol Arthrosc. 2007 May;15(5):500-7
17216271
Acta Orthop. 2007 Jun;78(3):355-60
17611849
Arch Orthop Trauma Surg. 2009 Mar;129(3):353-8
18594847
Am J Sports Med. 2008 Sep;36(9):1675-87
18490472
Am J Sports Med. 2002 Sep-Oct;30(5):660-6
12238998
J Bone Joint Surg Br. 1961 Nov;43-B:752-7
14038135
J Biomech. 1999 Apr;32(4):395-400
10213029