1. EFFECTS OF HAMSTRING TENDON VS PATELLAR TENDON GRAFTS ON KNEE STABILITY FOLLOWING ACL RECONSTRUCTION Adrien Brudvig and Sha’ Howard ESS 265 A Research Methods in Athletic Training

2. BACKGROUND INFORMATION  Anterior cruciate ligament (ACL) tears commonly occur in those participating in high-risk sports.  Occur from indirect trauma (cutting, twisting, jumping, etc.)  Damage to ACL leads to knee instability.  Reconstructive surgery is required to return full function.  Graft choices to repaired ACL are hamstring tendon or patellar tendon graft.

3. PATELLAR TENDON GRAFT Advantages:  Heals in approx. 6-8 weeks.  90% - 95% success rate of returning to pre-injury level of play.  Stronger fixation following surgery.  Lower rate of graft failure. Disadvantages:  There is a large incision site.  Increased potential for patellar fractures and quadriceps muscle weakness.  Can rupture within the 6-8 weeks of surgery with overuse. Bone-patellar tendon-bone grafts (BTB) are the gold standard for reconstruction.

4. HAMSTRING TENDON GRAFT Advantages :  Lower rate of donor site morbidity.  Smaller incision site with less recovery pain.  Heals quicker at harvest site (3 months).  Associated with increased knee flexion strength and internal tibial rotation strength. Disadvantages :  Longer rehabilitation and recovery time.  Greater laxity diminishing knee stability.  Increased joint flexibility.  Surgeons are less familiar. Soft tissue to bone fixation.

5. PURPOSE  The purpose of this study is to investigate which anterior cruciate ligament graft is superior in providing knee stability post ACL reconstruction for athletes and non-athletes. Research Question  A comparative study on which ACL graft, patellar tendon or hamstring tendon, provides better results for knee stability.

6. HYPOTHESIS  The patellar tendon graft will have a better outcome on knee stability than the hamstring tendon graft. Delimitations  Patients with ACL rupture with no surrounding structural damage or prior knee injuries.  ACL reconstruction with either patellar tendon graft of hamstring tendon graft.

7. PARTICIPANTS  Males and Females  Athletes and non-athletes  18-50 years of age  Ruptured ACL and no other structural damage to the affected knee.  Potential subjects referred to study from Orthopedic surgeons who preformed ACL reconstruction  Hamstring tendon or Patellar tendon grafts

8. INSTRUMENTATION  Pivot Shift Test: measures anterior tibial translation; 0-3 grading scale.  Tegner Activity Scale: rating scale used to determine patients perception of knee stability before and after surgery.  Single Leg Hop: measures functional performance.  KT-1000 Arthrometer: measures side-to-side laxity and anterior tibial displacement.  Kinesthetic Ability Trainer: evaluates balance.

9. PROCEDURES  IRB approval.  Obtain medical records from orthopedic surgeons.  Send mass email containing brief description of study.  Face-to-face contact.  Mass meeting providing details and obtain consent forms.  Pretesting will begin immediately for baseline values.  Post-operative testing will begin post operative-one day.  Testing will be done once a week for six months.  Each participant will participate in identical rehabilitation protocol.  Testing will consist of: Tegner Activity Scale, Single Leg Hop, Pivot Shift, KT-1000, KAT 2000.

10. STATISTICAL ANALYSIS  Analysis of Variance (ANOVA)  Will allow variances to be seen for multiple test over an extended amount of time.  Data will include results from each participant for all five tests. Expected Outcomes  The patellar tendon graft group will contain greater statistical outcome data supporting stronger knee stability after ACL reconstruction surgery compared to hamstring tendon.