Aneurysmal bone cyst is not encountered frequently and only one previous instance of this lesion of the patella has been reported in the literature. This case, a twenty-two years old R.O.K. army soldier, complained of pain and swelling in the knee joint. Radiologically, the patella was involved, showing a large oval, lytic decreased density with a sharply circumscribed expanded thin margin within the entire patella with an irregular margin at the middle of the articular surface. The patella was excised. Pathological examination revealed grossly and microscopically an aneurysmal bone cyst. The patient made an uneventful recovery, and, two years later, he had a stable knee and no complaints.
Adult ; Bone Cysts*/pathology ; Case Report ; Human ; Male ; Patella*/blood supply ; Patella*/injuries ; Patella*/pathology

Adult ; Fascia ; blood supply ; transplantation ; Female ; Humans ; Male ; Middle Aged ; Patella ; surgery ; Soft Tissue Injuries ; surgery ; Surgical Flaps

OBJECTIVETo investigate the incidence rate of anterior knee pain after total knee arthroplasty (TKA) and identify the related factors.

METHODSThis prospective, double-blind clinical trial involved a total of 128 patients scheduled for primary ipsilateral cemented three-component TKA for osteoarthrosis. The patients were randomized into two groups to receive operations for TKA with patellar resurfacing (experimental group) or not (control). The incidence of anterior knee pain was observed in these patients and the factor affecting the occurrence of anterior knee pain and knee was analyzed.

RESULTSThe patients were followed up for a mean of 16.5 months (range 6~24 months). The incidence rate of anterior knee pain was 10.9% (7/64) in the experimental group, showing no significant difference from the rate of 14.1% (9/64) in the control group. But the 52 patients with varus or valgus knee showed a significantly higher incidence rate of anterior knee pain (21.2%, 11/52).

CONCLUSIONTKA with patellar resurfacing can not decrease the incidence of anterior knee pain, and varus or valgus before the operation is associated with a higher risk of anterior knee pain.

Aged ; Arthroplasty, Replacement, Knee ; adverse effects ; methods ; China ; epidemiology ; Denervation ; methods ; Double-Blind Method ; Female ; Humans ; Knee Joint ; blood supply ; Male ; Middle Aged ; Osteoarthritis, Knee ; surgery ; Patella ; surgery ; Patellofemoral Pain Syndrome ; epidemiology ; etiology ; physiopathology ; Risk Factors