A 21 % conversion rate to total knee arthroplasty of a first-generation patellofemoral prosthesis at a mean follow-up of 9.7 years

Abstract

A 21 % conversion rate to total knee arthroplasty of a first-generation patellofemoral prosthesis at a mean follow-up of 9.7 years (range, 110-200). Median VAS Pain was 30 (range, 0-80) and VAS Satisfaction median was 90 (range, 50-100). Thirteen (62 %) PFAs were rated excellent, six (28 %) as good and two (10 %) as fair. Twelve (36 %) of the cases required further surgery within 4 years after implantation. Seven of these (21 %) were converted to TKA after a mean time of 5.5 years, five out of seven were converted because of ongoing tibiofemoral osteoarthritis (TFOA).Conclusions We found a rate of 21 % (7/33) conversion of the Richards' II PFA to TKA after a mean of 5.5 years; 71 % (5/7) of cases were because of TFOA. We strongly advise not to use PFA if there is any sign of joint disease in other compartments than patellofemoral.

Conversion Total Knee Arthroplasty

“…This finding was explained by the fact that the anterior and distal femoral TKA cuts ultimately eliminated any residual bone defect following explanation of the trochlear component from the prior PFA. With respect to the patellar button from the previous PFA, several studies have demonstrated that either preservation or removal can be accomplished with minimal difficulty 37,91 . For instance, Lonner et al left the patellar button in place in all cases 37 , and van Jonbergen et al revised the button in all cases because the implant had a poor track record 81 .…”

Wenn nichts mehr geht: Der patellofemorale Gelenkersatz

“…36 % der Prothesen mussten sich 4 Jahre nach Implantation einem weiteren Eingriff unterziehen. Nach 5,5 Jahren wurden 21 % auf eine totalendoprothetische Versorgung konvertiert 35 . Die Daten der Endoprothesenregister zeigen jedoch auch, dass pro Chirurg nur wenige patellofemorale Prothesen implantiert werden.…”

Advances in Patellofemoral Arthroplasty

“…Design limitations, such as narrow anterior femoral flange width and suboptimal trochlear implant geometry, led to patellar tracking problems, instability, subluxation, and impingement. Failure rates were reported between 17.8-44%, 20-33%, 10-42%, and 16-78%, in the Depuy's Autocentric™, Depuy's LCS™, Smith & Nephew's Richards™, and Waldemar's Lubinus™, respectively [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23].…”