Bruni D., MD; Gagliardi M.,MD; Raspugli G.,MD; Grassi A., MD; Marko T.,MD; Akkawi I.,MD; Prof. Marcacci M.,MD. Rizzoli Orthopaedic Institute – Bologna, Italy

UKA with all-poly tibial component:  When using it?  Metal-Backed or All poly?  Which survival?  Which % of failure?  Which are most important causes of failure? literature is not UNIQUE !!!

Purposes of the study  1) perform a long-term survival analysis of a large sample of patients treated with UKA with 'all-poly“ tibial component  2) To evaluate the effect of BMI on the incidence of failure of the prosthesis.

Materials and Methods  280 consecutive patients treated with all-poly UKA  Average age: 68 years (53-84)  7pt lost at FU  Average BMI 28.2 (23-38)  Indications for treatment: 187 OA 89 ON

Evaluations:  Clinical: BMI,VAS, KSS [1] & WOMAC [2] scores  Radiographic: Tibio-femoral angle(FTA); Posterior tibial slope (TPS); Tibial plateau angle (TPA)  Average Follow Up: 10 years (7-13) [1] Insall JN, Dorr LD, Scott RD, Scott WN. Rationale of the Knee Society clinical rating system. Clin Orthop Relat Res Nov;(248):13-4. [2] 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.

Clinical results:

Results: survival Survival at 10 years: 87.6% Survival at 5 years: 90,8%

Other evaluations: Differences were not statistically significant

Other Clinical and radiographic evaluations:

Discussion: literature vs present study  Survival:  No. of revisions:  Causes of failure:  BMI influence: From 85% to 100% at 5-10 years of follow-up 87,6% at 10aa Highly variable until 87% at 5y 9,2%of revised patients in a 134 months FU study «Medial tibial collapse» as 1° cause Aseptic loosening as 1° cause Poor Outcome with BMI >35No SS differences for patients with BMI >30 PRESENT STUDY

Conclusions: UKA with all-poly tibial component  1) Satisfactory survival at more than 10 years of follow up of a large sample of patients with satisfactory clinical and functional outcomes.  2) BMI> 30 have no effect on the incidence of revision