To describe the risk of periprosthetic joint infection (PJI) and reoperation in patients who have an acute, traumatic wound dehiscence following total knee arthroplasty (TKA). From January 2002 to December 2018, 16,134 primary TKAs were performed at a single institution. A total of 26 patients (0.1%) had a traumatic wound dehiscence within the first 30 days. Mean age was 68 years (44 to 87), 38% (n = 10) were female, and mean BMI was 34 kg/m2 (23 to 48). Median time to dehiscence was 13 days (interquartile range (IQR) 4 to 15). The dehiscence resulted from a fall in 22 patients and sudden flexion after staple removal in four. The arthrotomy was also disrupted in 58% (n = 15), including a complete extensor mechanism disruption in four knees. An irrigation and debridement with component retention (IDCR) was performed within 48 hours in 19 of 26 knees and two-thirds were discharged on antibiotic therapy. The mean follow-up was six years (2 to 15). The association of wound dehiscence and the risk of developing a PJI was analyzed.Aims
Methods
The clinical diagnosis of a partial tear of the
anterior cruciate ligament (ACL) is still subject to debate. Little
is known about the contribution of each ACL bundle during the Lachman
test. We investigated this using six fresh-frozen cadaveric lower
limbs. Screws were placed in the femora and tibiae as fixed landmarks
for digitisation of the bone positions. The femur was secured horizontally
in a clamp. A metal hook was screwed to the tibial tubercle and
used to apply a load of 150 N directed anteroposteriorly to the
tibia to simulate the Lachman test. The knees then received constant
axial compression and 3D knee kinematic data were collected by digitising
the screw head positions in 30° flexion under each test condition.
Measurements of tibial translation and rotation were made, first with
the ACL intact, then after sequential cutting of the ACL bundles,
and finally after complete division of the ACL. Two-way analysis
of variance analysis was performed. During the Lachman test, in all knees and in all test conditions,
lateral tibial translation exceeded that on the medial side. With
an intact ACL, both anterior and lateral tibial landmarks translated
significantly more than those on the medial side (p <
0.001).
With sequential division of the ACL bundles, selective cutting of
the posterolateral bundle (PLB) did not increase translation of
any landmark compared with when the ACL remained intact. Cutting the
anteromedial bundle (AMB) resulted in an increased anterior translation
of all landmarks. Compared to the intact ACL, when the ACL was fully
transected a significant increase in anterior translation of all
landmarks occurred (p <
0.001). However, anterior tibial translation
was almost identical after AMB or complete ACL division. We found that the AMB confers its most significant contribution
to tibial translation during the Lachman test, whereas the PLB has
a negligible effect on anterior translation. Section of the PLB
had a greater effect on increasing the internal rotation of the
tibia than the AMB. However, its contribution of a mean of 2.8°
amplitude remains low. The clinical relevance of our investigation
suggests that, based on anterior tibial translation only, one cannot distinguish
between a full ACL and an isolated AMB tear. Isolated PLB tears
cannot be detected solely by the Lachman test, as this bundle probably
contributes more resistance to the pivot shift.
