Early active extension after anterior cruciate ligament reconstruction does not result in increased laxity of the knee

1. Early active extension after anterior cruciate ligament reconstruction does not result in increased laxity of the knee Dan Thorp

2. Background • Perhaps the most feared injury amongst all athletes • Without a functioning ACL, an athlete is generally unable to change direction without the knee joint collapsing

3. Reconstructive Surgery • The main goal of ACL surgery is to keep the tibia from moving too far forward under the femur bone and to have the knee functioning normally again • Most surgeons perform this surgery using an arthroscope, a small fiber-optic TV camera that is used to see and operate inside the joint • After surgery, the knee joint loses flexibility, and the muscles around the knee tends to undergo atrophy • All treatment options require extensive physical therapy to build up muscle strength around the knee and to restore range of motion

4. Arthroscopic Pictures of Normal and Torn Anterior Cruciate Ligaments

5. Methods • Patients with: unilateral traumatic ACL rupture • No injury history with other knee, multiple knee ligament tears • 22 patients selected: 14 men & 8 women, aged 16-41 • Arthroscopy performed on all patients & implanted tantalum markers in both knees: 4 to 5 in the distal femur & proximal tibia areas • Used patellar tendon autograft to create a new ACL with 20mm metal screws • Randomized rehab groups: Group A was allowed to have restricted motion (30°and -10°); Group B was not

6. Methods • Range of motion was evaluated pre-operation, 6 months & 2 years post-operation • By the end of week 4, both group had their brace removed • At week 5, active and passive extension without restriction was allowed for both groups as they progressed to stairs, jogging, and uneven surfaces by week 24 • After 25 weeks of rehab, the patients returned to sports activities once muscle strength was 90% intact

7. Radiostereometric Analysis • Evaluates laxity and kinematics at the following positions: • Extended knee 0° • 30° of flexion

8. Radiostereometric Analysis

9. Results • Mean results of laxity measurements

10. Discussion • The study did not reveal any significant differences in knee laxity • Early active and passive extension training is safe, does not jeopardize the laxity of the knee • Not able to document any clinical superiority in knee function using early extension protocol at the 6 month or 2 year follow-ups

11. Discussion • More patients regained hyperextension of the injured knee in the early extension training group compared to the traditional group • Early active and passive training without restriction immediately after ACL reconstruction with a patellar tendon autograft appears to be safe

12. References • Isberg, Jonas. “Early active extension after anterior cruciate ligament reconstruction does not result in increased laxity of the knee.” Spring-Verlag 2006 • http://direct-healthcare.com/images/acl.jpg • http://www.emedx.com/emedx/diagnosis_information/knee_disorders/acl_arthroscopic_pictures_normal_and_torn.htm • http://biomed.brown.edu/orthopaedics/Bioengineering/ACL.html