Structural allografts may be used to manage uncontained
bone defects in revision total knee replacement (TKR). However,
the availability of cadaver grafts is limited in some areas of Asia.
The aim of this study was to evaluate the mid-term outcome of the
use of femoral head allografts for the reconstruction of uncontained
defects in revision TKR, focusing on complications related to the
graft. We retrospectively reviewed 28 patients (30 TKRs) with Anderson
Orthopaedic Research Institute (AORI) type 3 bone defects, who underwent
revision using femoral head allografts and stemmed components. The
mean number of femoral heads used was 1.7 (1 to 3). The allograft–host
junctions were packed with cancellous autograft. At a mean follow-up of 76 months (38 to 136) the mean American
Knee Society knee score improved from 37.2 (17 to 60) pre-operatively
to 90 (83 to 100) (p <
0.001). The mean function score improved
from 26.5 (0 to 50) pre-operatively to 81 (60 to 100) (p <
0.001).
All the grafts healed to the host bone. The mean time to healing
of the graft was 6.6 months
(4 to 16). There have been no complications of collapse of the graft,
nonunion, infection or implant loosening. No revision surgery was
required. The use of femoral head allografts in conjunction with a stemmed
component and autogenous bone graft in revision TKR in patients
with uncontained bone defects resulted in a high rate of healing
of the graft with minimal complications and a satisfactory outcome.
Longer follow-up is needed to observe the evolution of the graft. Cite this article:
We present the operative technique and clinical results of concomitant reconstruction of the medial collateral ligament (MCL) and the posterior oblique ligament for medial instability of the knee using autogenous semitendinosus tendon with preservation of the tibial attachment. The semitendinosus tendon graft between the screw on the medial epicondyle and the tibial attachment of the graft was overlapped by the MCL, while the graft between the screw and the insertion of the direct head of the semimembranosus tendon was overlapped by the central arm of the posterior oblique ligament. Assessment was by stress radiograph and the Lysholm knee scoring scale. After a mean follow-up of 52.6 months (25 to 92), the medial joint opening of the knee was within 2 mm in 22 of 24 patients. The mean Lysholm score was 91.9 (80 to 100). Concomitant reconstruction of the MCL and posterior oblique ligament using autogenous semitendinosus tendon provides a good solution to medial instability.
We have investigated the changes in anterior laxity of the knee in response to direct electrical stimulation of eight normal and 45 reconstructed anterior cruciate ligaments (ACLs). In the latter, the mean time from reconstruction was 26.7 months (24 to 32). The ACL was stimulated electrically using a bipolar electrode probe during arthroscopy. Anterior laxity was examined with the knee flexed at 20° under a force of 134 N applied anteriorly to the tibia using the KT-2000 knee arthrometer before, during and after electrical stimulation. Anterior tibial translation in eight normal and 17 ACL-reconstructed knees was significantly decreased during stimulation, compared with that before stimulation. In 28 knees with reconstruction of the ACL, in 22 of which the grafts were found to have detectable somatosensory evoked potentials during stimulation, anterior tibial translation was not decreased. These findings suggest that the ACL-hamstring reflex arc in normal knees may contribute to the functional stability and that this may not be fully restored after some reconstructions of the ACL.
