Varus migration of PCA stems.
Forty-seven patients with cementless, porous-coated anatomic hip replacements were evaluated after a minimum 2-year follow up with specific attention to varus migration of the stem. A cadaver study was done to define a relationship between projected size of the lesser trochanter seen radiographically, rotation of the femur, and stem position. Seven (15%) of the stems migrated into varus with the distal tip moving laterally. Thigh pain occurred in patients with varus migration and those with no change in stem position. A lower percent canal fill was seen on the lateral radiograph (P < .001) and larger average width of radiodense lines in zone 1 superolateral, and zone 6, midstem medial (P < .005) in the patients with varus migration. Poor distal stability associated with a lower percent canal fill at the stem tip seen on the lateral radiograph may result in varus migration.
Ries
M D
MD
Mary Imogene Bassett Hospital, Cooperstown, NY 13326, USA.
Lynch
F
F
Jenkins
P
P
Mick
C
C
Richman
J
J
D001696:Biomechanical Phenomena; D002102:Cadaver; D005069:Evaluation Studies as Topic; D005260:Female; D005500:Follow-Up Studies; D006622:Hip Prosthesis / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D015994:Incidence; D007593:Joint Instability / Q000000981:diagnostic imaging; D008297:Male; D011475:Prosthesis Failure; D011859:Radiography