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

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.

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.

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.

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.

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.

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

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.

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.

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.