It is widely held that most Baker’s cysts resolve after treatment
of the intra-articular knee pathology. The present study aimed to
evaluate the fate of Baker’s cysts and their associated symptoms
after total knee arthroplasty (TKA). In this prospective cohort study, 102 patients with (105 were
included, however three were lost to follow-up) an MRI-verified
Baker’s cyst, primary osteoarthritis and scheduled for TKA were
included. Ultrasound was performed to evaluate the existence and
the gross size of the cyst before and at one year after TKA. Additionally,
associated symptoms of Baker's cyst were recorded pre- and post-operatively.Aims
Patients and Methods
We investigated the role of ion release in the assessment of fixation of the implant after total knee replacement and hypothesised that ion monitoring could be a useful parameter in the diagnosis of prosthetic loosening. We enrolled 59 patients with unilateral procedures and measured their serum aluminium, titanium, chromium and cobalt ion levels, blinded to the clinical and radiological outcome which was considered to be the reference standard. The cut-off levels for detection of the ions were obtained by measuring the levels in 41 healthy blood donors who had no implants. Based on the clinical and radiological evaluation the patients were divided into two groups with either stable (n = 24) or loosened (n = 35) implants. A significant increase in the mean level of Cr ions was seen in the group with failed implants (p = 0.001). The diagnostic accuracy was 71% providing strong evidence of failure when the level of Cr ions exceeded the cut-off value. The possibility of distinguishing loosening from other causes of failure was demonstrated by the higher diagnostic accuracy of 83%, when considering only patients with failure attributable to loosening. Measurement of the serum level of Cr ions may be of value for detecting failure due to loosening when the diagnosis is in doubt. The other metal ions studies did not have any diagnostic value.
