1. Rizzoli Orthopaedic Institute – Bologna, Italy
Three different cruciate sacrificing TKA designs: no intraoperative kinematic differences and no clinical differences at 2 years follow up.
Bruni D, Bignozzi S, Zaffagnini S, Akkawi I, Marko T, Gagliardi M, Colle F, Marcacci M.

2. Why using Navigation system?
Better limb alignment
Better implant positioning
Sparmann et al
Amiot et al
Decking et al
Saragaglia et al 2001
Jenny et al
Kim et al
Anderson et al
Novak et al
Brin, Int Orthop 2010
Biasca, Orthop Clin North Am. 2009
Dorr, Orthopedics. 2009
Berend ME. Orthopedics. 2009
Dattani R. Int Orthop. 2009
Sikorski JM. Jbjs Br. 2008
Mason JB, J Arthroplasty. 2007
Claus A, Orthopade. 2007
Briard JL, Orthopade. 2007
Siston RA, J Biomech. 2007
Laskin RS CORR. 2006
Perlick et al
Haaker et al
Chauahan et al 2004
Bathis et al
Matziolis et al. 2007
Comparable surgical times
Less blood loss
Chauhan et al
Martin et al
Decking et al
Matziolis et al
Kim et al
Kalairajah et al 2007

3. Clinical efficacy has not yet been demonstrated
1/4 patients in USA,UK & Canada are not satisfied
Regardless of whether CAS or conventional
Can we use navigation system to evaluate intraoperative clinical and functional differences in different implants?

4. Materials and Methods 90 patients with primary OA
Average age at surgery: 70 years (57-85)
Randomized distribution into 3 groups of cruciate sacrificing TKA
“3° Condyle“- MB (CS) ULTRACONGRUENT-MB (AS) SPINE CAM-MB (PS)

5. Intraoperative kinematics acquisition:
PROM: passive range of motion, (0°-120°)
AP90: Drawer test at 90 ° of flexion, exerting maximum force
VV Stress Test at 0° and 30°
Test repeated 3 times

6. Materials and methods
Clinical evaluation using standardized scores: WOMAC [1], KSS-f [2], SF-36 [3]
 [1] Roos EM, Roos HP, Lohmander LS, Ekdahl C, Beynnon BD. Knee Injury and Osteoarthritis Outcome Score (KOOS)--development of
a self-administered outcome measure. J Orthop Sports Phys Ther Aug;28(2):88-96.
 [2] Insall JN, Dorr LD, Scott RD, Scott WN. Rationale of the Knee Society clinical rating system. Clin Orthop Relat Res Nov;(248):13-4.
[3] Ware JE Jr, Sherbourne D. The MOS 36-item short-form health survey (SF-36). I. Conceptual framework and item selection. Med Care
 1992 Jun;30(6):

7. Under stress VV Laxity at 0° e 30°
«3° condyle» -MB
ULTRACONGRUENT-MB (AS)
SPINE CAM-MB
Significative reduction at 0° (p=0.006)
Not significant at 30°
No statistical differences between the three models
Laxity reduction VV 0°:
-3,1° ’’3rd CONDYLE’’
-2,4° ULTRACONGRUENT-MB
-2,3° SPINE CAM-MB
Laxity reduction VV 30°:
-0° ’ ’3rd CONDYLE’’
-1,1° ULTRACONGRUENT-MB
-1,1° SPINE CAM-MB

8. Under stress AP 90 Laxity Under stress AP 90 laxity
«3° condyle» -MB
ULTRACONGRUENT-MB (AS)
SPINE CAM-MB
Under stress AP 90 laxity
2mm of laxity reduction for ‘’3° CONDYLE’’ model (p=0.007)
4.9mm of laxity increase for ULTRACONGRUENT-MB model (p=0.008)
5mm of laxity increase for SPINE CAM-MB model (p=0.008)

9. Internal (-) and External (+) tibial rotation during flexion
Postoperative reduction of Internal rotation in all 3 models
More stable pattern for SPINE CAM-MB e ’’3rd Condyle’’
A) SPINE-CAM MB
NOT statistically significant
B) “3° CONDYLE“- MB
C) ULTRACONGRUENT-MB

10. NOT statistically significant
B) “3rd CONDYLE“- MB
AP translation (mm)
Of femoral epicondyles during flexion
C) ULTRACONGRUENT-MB
NOT statistically significant
A) SPINE-CAM MB
Slightly better pattern in SPINE CAM-MB

11. Clinical results

12. CONCLUSIONS
Reduction of tibial internal rotation after surgery, increased posterior translation of the femoral epicondyles in all three models
Better AP stability was noticed in ‘’3rd condyle’’ model
No significant differences in clinical score at 2 years in all 3 models

13. Thank you for your attention