The Wisconsin noncemented femoral stem. A prospective study with 5 to 9 years of follow-up evaluation.
In an attempt to decrease aseptic loosening, total joint components are now being used without cement. Most components are designed to achieve fixation biologically. The radiographic results of 144 primary uncemented total hip arthroplasties and the clinical results of 89 arthroplasties that were performed using a proximally porous-coated titanium alloy femoral stem between November 1983 and June 1989 are reported. On the acetabular side, a threaded component or a hemispherical porous-coated component was used. The patients were followed prospectively for 5 to 9 years postsurgery. During the study period, the threaded acetabular component had a high failure rate. Because it was not possible to determine accurately from which component a particular sign or symptom arose, clinical analysis was restricted to only those hips without a failed or revised cup. Eighty-nine hips in 71 patients with a minimum follow-up period of 5 years were available for clinical review. Radiographic review of the femoral stem was completed on all hips with 5 or more years of radiographic follow-up evaluation regardless of the status of the acetabular component. One hundred twelve hips in 85 patients were analyzed radiographically. At a latest mean follow-up period of 6.7 years, the mean Iowa hip score was 91.4 +/- 8.0 with a 5.4% incidence of thigh pain. Throughout the follow-up period, the patients with thigh pain had a statistically lower mean Iowa pain subscore when compared with those patients without thigh pain (P=.0001). Endosteal erosion was seen in two hips (1.8%) and longitudinal loss of the medial neck greater than 2 mm was noted in two hips. One femoral stem was revised for aseptic loosening. The clinical results of this femoral stem equal or exceed the published accounts of other arthroplasties. The results indicate that the stem is associated with good clinical results, minimal bone loss, and little osteolysis. Continued follow-up evaluation of patients with this femoral stem is necessary to assess the durability of these encouraging results.
Scerpella
P R
PR
University of Wisconsin Hospital and Clinics, Madison, USA.
McBeath
A A
AA
Checovich
M M
MM
D000328:Adult; D000368:Aged; D002484:Cementation; D005260:Female; D005500:Follow-Up Studies; D006621:Hip Joint / Q000000981:diagnostic imaging; D006622:Hip Prosthesis / Q000009:adverse effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D012086:Reoperation