Introduction: knee revision in absence of Extensor Mechanism has been always a challenging problem in Orthopaedics. Many authors are in favour to abandone any endoprosthetic substitution in front of such a situation.
We think osteotendinous allografts, in this particular case whole Extensor Mechanism allografts, could play an essential role before any Knee Arthrodesis.
Material and Method: From 1999 up to 2004 11 patients (4 male, 7 female) (mean age 72, range 68 to 86) underwent to a whole Extensor Mechanism allografting procedure. Mean follow up was 2.7 years (1 to 5 years).
In the first four cases a whole Extensor Mechanism allograft was implanted, while the next seven cases the allograft was reinforced by means of a Leeds-Keio Dacron band.
Results: There was no infections in this serie. The mean obtained R.O.M. in the first three months was – 5 of active extension (range 0 to −15) and 95 active flexion (range 80 – 110). However 3 from the 4 former operated cases had a progressive loss of active extension up to −25 (range −20 to −35) at 18 months, that did not increase after this period. Ultrasonic exams showed a lengthening of the patellar tendon in these cases. None of these 3 patients wished to undergo to a patellar tendon reinforcement.
On the other hand those later cases, where patellar tendon was reinforced did not show any change over the time (at 18 months mean active extension was maintained to −5 (range 0 to 15)
Conclusions: Extensor mechanism allografts are very useful in difficult knee revisions with absence of extensor mechanism, so that knee arthrodesis is not the method of choice for these patients. However augmentation of patellar tendon is necessary to maintain with the years an active extension.