We report the natural course of Baker’s cysts following total knee arthroplasty (TKA) at short- and mid-term follow-up. In this prospective case series, 105 TKA patients were included. All patients who received surgery had a diagnosis of primary osteoarthritis and had preoperatively presented with a Baker’s cyst. Sonography and MRI were performed to evaluate the existence and the gross size of the cyst before TKA, and sonography was repeated at a mean follow-up time of 1.0 years (0.8 to 1.3; short-term) and 4.9 years (4.0 to 5.6; mid-term) after TKA. Symptoms potentially attributable to the Baker’s cyst were recorded at each assessment.Aims
Methods
Disruption of the extensor mechanism in total
knee arthroplasty may occur by tubercle avulsion, patellar or quadriceps
tendon rupture, or patella fracture, and whether occurring intra-operatively
or post-operatively can be difficult to manage and is associated
with a significant rate of failure and associated complications.
This surgery is frequently performed in compromised tissues, and
repairs must frequently be protected with cerclage wiring and/or
augmentation with local tendon (semi-tendinosis, gracilis) which
may also be used to treat soft-tissue loss in the face of chronic
disruption. Quadriceps rupture may be treated with conservative
therapy if the patient retains active extension. Component loosening
or loss of active extension of 20° or greater are clear indications
for surgical treatment of patellar fracture. Acute patellar tendon
disruption may be treated by primary repair. Chronic extensor failure
is often complicated by tissue loss and retraction can be treated
with medial gastrocnemius flaps, achilles tendon allografts, and
complete extensor mechanism allografts. Attention to fixing the
graft in full extension is mandatory to prevent severe extensor
lag as the graft stretches out over time.
The patellar clunk syndrome describes painful catching, grinding or jumping of the patella when the knee moves from a flexed to an extended position after total knee replacement (TKR). The posterior stabilised TKR had been noted to have a higher incidence of this problem. Mobile-bearing posteriorly stabilised TKRs have been introduced to improve patellar tracking and related problems by a mechanism of self-alignment. We evaluated the patellar clunk syndrome in 113 knees in 93 patients with such a TKR at a mean follow-up of 2.3 years (2.0 to 3.2). The syndrome was identified in 15 knees (13.3%). Logistic regression analysis showed that the absolute value of the post-operative angle of patellar tilt was significantly associated with the occurrence of patellar clunk (p = 0.025). Patellar tracking should be carefully checked during surgery.
