Validation of a New Technique for the Evaluation of the Patello-femoral Joint Kinematics
Phase: NA
Conditions: Knee Osteoarthritis
Sponsor: Istituto Ortopedico Rizzoli

 
1
 
 
 
 
 
VALIDATION OF A NEW TECHNIQUE FOR THE EVALUATION OF 
THE PATELLO-FEMORAL JOINT KINEMATICS 
 
 
Institutional Protocol ID: 
39521/2012 (CINE-FEMORO), 16th  November, 2012 
 
 
 

 
2
STUDY PROTOCOL 
The aim of this study is to test in vivo a new technique to evaluate the kinematics of the patella-
femoral joint in patients undergoing total knee replacement. In particular, this study is divided into 
two steps. In the first step, the acquisition of knee kinematics is acquired intra-operatively. This 
will allow the surgeon to have a more complete comprehension of the knee functioning. 
Moreover, since the prosthetic implantation can potentially alter the functioning of both tibio-
femoral joint and patello-femoral joint, it is necessary, in a second step, to perform knee kinematic 
evaluations at 6-months follow-up  on the same patients. In this way it will be possible to evaluate 
the biomechanical behavior of the replaced knee joint and to observe anomalies / differences with 
respect to both normal and pre-implantation joint. In the second phase, the acquisitions will be 
performed using videofluoroscopic and roentgen-stereophotogrammetric techniques. Moreover, 
always in the second phase, the clinical evaluation of enrolled patients allow to identify the 
specific advantages and potential complications associated with the prosthesis implantation . 
This study involves the recruitment of  20 patients selected for total knee replacement. The 
specific inclusion and exclusion criteria that can allow an adequate intra- and post-operative 
functional evaluation are reported in the main document. 
During the surgery, the alignment of the prosthetic components will be performed with the aid of 
a standard surgical navigation system (Stryker® - Leibenger, Freiburg-im-Breisgau, Germany) in 
addition to standard navigation-based procedure for femur and tibia prosthesis component 
positioning. Particularly, the intra-operative acquisitions of the tibio-femoral and patello-femoral 
morphology and kinematics will be performed by means a navigation system equipped with an 
additional innovative device for patellar-based data acquisitions. In addition to standard 
navigation steps, originally the surgeon will now collect the patellar medial, lateral and distal 
prominences, along with the anterior and the posterior aspect; this will allow to assess exactly the 
real patellar thickness and to set via computer-assistance the more proper position of the patellar 
cutting jig; once the patellar cut is executed, the surgeon can select the best location for 
positioning the patella polyethylene component using navigation-based data, in addition to usual 
visual inspection and standard, i.e. not computer-assisted, procedures. Six months after the 
surgery, 3D vidoe-fluoroscopic analysis and gait analysis combined with electromyography will be 
performed on the same patients to evaluate in vivo replaced knee kinematics and kinetics during 
the execution of a number of motor tasks of daily living; clinical scoring will be performed at 6, 12 
and 24 months follow-ups.  

 
3
STATISTICAL PLAN 
The population size was estimated by considering previously reported data obtained using the 
same acquisition technique of the present study [1,2], and by meeting the criteria for achieving 
differences in measurements with 80 % statistical power and an α-level of 0.05. The differences in 
patellar implantation parameters and kinematic variables and before and after total knee 
replacement treatment were tested for significance using the paired t-test and one-way analysis of 
variance. P values were considered significant for p<0.05.  
 
1. Belvedere C, Ensini A, Feliciangeli A, Cenni F, D'Angeli V, Giannini S, Leardini A (2012) Geometrical changes of knee 
ligaments and patellar tendon during passive flexion. J Biomech 493 45:1886-1892. 
 
2. Belvedere C, Ensini A, Leardini A, Bianchi L, Catani F, Giannini S (2007) Alignment of resection planes in total knee 
replacement obtained with the conventional technique, as assessed by a modern computer-based navigation 
system. Int J Med Robot 3:117-124. 

 
4
 
DECLARATION OF CONSENT 
 
I declare to have received from Dr. ______________exhaustive explanations regarding the request 
to participate to the experimental study (study title:__________), whose details are reported in 
the annexed study protocol. 
I also declare that I have been able to discuss on the study aims, to ask all relevant questions that I 
have deemed necessary and to have received satisfactory answers, as well as to have had the 
opportunity to inform me about the details of the study with a person of my trust. 
I therefore freely agree to participate in the experimentation, having completely understood the 
meaning of the participation request and having understood the risks and benefits involved. 
I have also been informed of my right to have free access to the documentation related to the 
experimental evaluation and to the evaluation expressed by the Institutional Ethics Committee. 
Date Signature of the patient 
________________ ___________________________________ 
 
Date Signature of the doctor who informed the patient 
________________ ___________________________________ 
 
[In case the patient can not read and / or sign] 
I _____________________ testify that Dr. _________________has fully explained to Mr. 
__________________the features of the experimental study, as reported in the annexed 
documentation, and that I, by having had the opportunity to ask all the questions that I deemed 
necessary, freely accepted to participate to this the study. 
Date Signature of the independent witness 
________________ ___________________________________