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Chronic ruptures of the extensor mechanism
can be classified as chronic patellar tendon
ruptures, chronic quadriceps tendon ruptures,
and neglected patellar fractures.
Patellar tendon rupture is a rare but devastating
injury that frequently results from significant
trauma. Primary repair with or without
augmentation often yields good outcomes
when tears are addressed promptly after injury.
Reconstruction of chronic ruptures of the
patella tendon is often difficult because of the
proximal retraction of the patella, quadriceps
muscle contracture and scarring, and poor
quality of the remaining patellar tendon tissue.
Various methods have been described for
addressing chronic tears of the patellar tendon.
If sufficient healthy native patellar tendon
remains, primary repair followed by
augmentation with hamstring tendon [1, 2],
cerclage wire [3], or PDS tape [4] can be
successful. If the native tendon is completely
lost, reconstruction with allograft tissue is an
option. Previous authors have described the use
of Achilles tendon allograft in this situation [5].
Dejour
et al.
[6, 7] described the use of a
contralateral extensor mechanism autograft to
reconstruct chronic patellar tendon ruptures.
The contralateral autograft consisted of a tibial
bone block, the middle third of patellar tendon,
a patellar bone block, and the central portion of
the quadriceps tendon. Because of themorbidity
of contralateral graft harvest, the technique was
subsequently modified to use an extensor
mechanism allograft of the same shape [8, 9]
(fig. 1, 2).
Chronic rupture of
the extensor mechanism
(TKA and patellar fracture excepted)
S. Lustig, R.A. Magnussen, G. Demey,
E. Servien, P. Neyret
Fig. 1: Reconstruction of Chronic Patellar
Tendon Ruptures with partial extensor
mechanism allograft