Kushal Shah BS, Matthew Stonestreet MD, Kerwyn Jones MD, Marcus Kirkpatrick MD, Caroline Frampton, Melanie Morscher PT,

John J Elias PhD

Akron General Medical CenterAkron Children’s Hospital

GrantsAkron General Medical Center Development Foundation

Akron Children’s Hospital FoundationAkron Chamber of Commerce

No Other Disclosures

ACL injuries in skeletally immature children are increasing

Non-operative management may lead to meniscal injuries & osteoarthritis

Adult ACL techniques cross the growth plate: possible leg length & angular deformities

Anderson developed an All-Epiphyseal drill technique Anderson, JBJS . 2004;86- A Suppl 201-9

ACL-deficient knee increases anterior translation, shifts contact posteriorly on tibia, and increases cartilage deformation

Yoo et al. Am J Sports Med 33:240-6, 2005, Li et al., J Bone Joint Surg Am. 2006 88:1826-34, 2006

Hypothesis: All-epiphyseal ACL reconstruction will improve tibiofemoralcontact, shifting force anteriorly on the tibia and reducing contact force magnitudes as compared to the ACL-deficient knee

10 Cadaveric Knees Tested

ACL cut and reconstructed All-Epiphyseal ACL-reconstructed knee tested ACL-cut knee tested (removed graft) Tekscan K-scan

sensor inserted under meniscus

Center of force &max medial & lateral force

Testing Conditions Knees were tested at 00,150,300, and 450 of

flexion

3 different loading conditions1. 1. Quadriceps (586 N)+ Anterior

Force (100 N): most unstable

2. Quadriceps Alone

3. Quadriceps +Hamstrings (100 N): most stable

Paired t-tests to compare ACL-Reconstructed & ACL-Cut conditions

Center of Force

• Medial plateau: Center of force 2 mm more anterior for reconstructed condition than cut

• Lateral plateau: Center of force more anterior for reconstructed condition (except at 0˚)

• Changes in medial-lateral direction primarily at 0

A, M =

significant

differences

in anterior

(A) and

medial (M)

directions at

p < 0.05

0 deg

15 deg

30 deg

45 deg

Maximum Lateral Force

Significantly larger for ACL-cut than reconstructed at 45˚for 2 loading conditions

Maximum Medial Force

Significantly larger for reconstructed at 15˚ with hamstring loadingTrend for increased force with anterior load

Total Force Ratio

Graft tension increased contact force

Previous studies have shown a posterior shift of the center of force related to ACL injury in vivo, more so on the medial than lateral plateau

Li et al. . J Bone Joint Surg Am. 88:1826-34, 2006

ACL reconstruction reversed direction of this change

Limitations

Cadaver study (tissue fatigue, skeletally mature specimens)

Time zero study (relaxation of the graft, bony ingrowth, loosening

of screws)

Absence of contact data for intact vs. cut knees (could

not maintain integrity and position of sensor while cutting ACL or performing reconstruction)

All-Epiphyseal ACL Reconstruction

Shifts contact anteriorly on the tibia

Decreases force for loading conditions more likely to induce instability