Functional Outcome Comparison of Implant-Free Bone-Patellar Tendon Autografts Using Press-Fit Fixation Technique and Hamstring Autografts Using Implant in Arthroscopic Anterior Cruciate Ligament Reconstruction: A Prospective Study
Phase: PHASE1
Conditions: Anterior Cruciate Ligament Injuries, Ligament; Rupture, Knee, Spontaneous, Tendon Graft; Complication, Mechanical
Sponsor: Indonesia University

 
 
 
STUDY PROTOCOL 
 
 
Functional Outcome Comparison of Implantless Bone-Patellar Tendon Autografts Using Press-
Fit Fixation Technique and Hamstring Autografts Using Implant in Arthroscopic Anterior 
Cruciate Ligament Reconstruction: A Prospective Study 
 
 
NCT number: not yet registered 
 
March 1, 2013 
 
 

Study Protocol 
Diagnosis of ACL rupture was done by physical examination using Lachman Test, Anterior 
Drawer Sign Test, and Pivot Test on both knee. Another test was also performed to exclude another 
knee ligament rupture, such as Posterior Drawer Test, Varus & Valgus Test. MRI was obtained to 
make an accurate diagnosis for ACL rupture using 3 projection, which were coronal, sagittal, and 
axial, each on T1 and T2 weighted image. After the diagnosis was confirmed, than the subject 
underwent a surgery performed by single same operator in Sports Injury Division of Orhopaedic 
Department in Gatot Soebroto Army Hospital. 
Anterior cruciate ligament (ACL) reconstruction on the main treatment group was using press-fit 
graft fixation technique by Edgar Michael (Figure 1). After the subject was positioned in prone, 
area of surgery was draped with aseptic and antiseptic technique. A midline skin incision was made 
that extends from inferior pole of patella up to anterior tibial tuberosity. Patella tendon with tibial 
tuberosity bone block were harvested, patella bone was left intact. The tendon was fixed together 
with non-absorbable suture. 
The knee was fully flexed. Femoral tunnel was drilled at 2 mm from posterior wall of lateral 
condyle on 1 o’clock and 11 o’clock. Bone plug were prepared into cone shape with the length 
equal to the femoral tunnel length. The diameter of the bone plug was 1 mm more than the femoral 
diameter to ensure press-fit mechanism. The ACL insertion at tibia was determined 8-10 mm in 
front of PCL insertion. The tunnel was made at an angle of 60 degrees to the distal direction. 
Bone block were inserted into the femoral tunnel and the patella tendon was inserted into the tibia 
tunnel. Small hole was drilled by using a 2.0 K-wire at the distal opening of tibia tunnel. Fixation 
of the end of tendon graft was made into the hole by using polyester non-absorbable suture. 
Fixation was made by manual tensioning, double knots and posterior drawer position to ensure 
tight fixation. The wound was sutured layer by layer. 

 
Figure 1. Schematic of the implantless press-fit ACL reconstruction 
 
On the other hand, comparison treatment group in our study uses hamstring tendon graft for ACL 
reconstruction, fixed by endobutton implant for femoral fixation and bioscrew for tibial fixation. 
Objective functional outcome is obtained by using a Rollimeter when doing a Lachman Test 
(Figure 2), performed at preoperation and 6 months postoperation. For subjective functional 
outcome, was obtained by IKDC Subjective Knee Evaluation Form (IKDC), Tegner Lysholm 
Knee Scoring Scale (Tegner) and Knee Injury and Osteoarhtritis Outcome (KOOS). It was 
performed at preoperation, 1 month, 3 months and 6 months postoperation. 
 
Figure 2. Rollimeter measurement 

 
Statistical Analysis Plan 
Statistical data was processed with SPSS ver. 18 (IBM). Statistical test using Pearson Chi Square 
or Exact Fisher Test for proportion data. Paired T-test or Mann-Whitney U/Wilcoxon sum rank 
and McNemar for continuous numeric data.