title: Patellofemoral complications with the Insall-Burstein II posterior-stabilized total knee arthroplasty.
abstract: The Insall-Burstein and Insall-Burstein II posterior-stabilized (I-B II PS) prostheses have been reported to have a high prevalence of patellar complications. This is a prospective, consecutive study of 118 primary total knee arthroplasties in 82 patients with the I-B II PS prosthesis implanted by 1 surgeon, using a specific technique for patellar resurfacing. The mean follow-up time was 4.0 years (range, 2-8 years). Clinical evaluation was performed using a standard knee score system with specific additional evaluation of the patellofemoral joint. Radiographs were evaluated for fracture, loosening, and subluxation. Ninety-four knees (80%) were rated excellent, 21 knees (17%) good, and 3 knees (3%) fair. The mean flexion was 112 degrees postoperative. No knee required reoperation for the patellofemoral joint. There were 2 nondisplaced and 1 minimally displaced patellar fractures treated nonoperatively, no patellar clunk syndrome, and no subluxations. Using the patellar evaluation system, 109 knees had no anterior knee pain, 7 knees had mild pain, and 2 knees (1 patient) had moderate-to-severe pain only with rising from a chair. Patellofemoral crepitus with active flexion-extension in the seated position was noted in 16 knees (14%) but was painful in only 2 knees (1 patient). With this technique for patellar resurfacing with this prosthesis, patellofemoral complications were only 4.2%, and no knee required reoperation for the patella or for loosening. With attention to operative technique, patellofemoral resurfacing with this posterior-stabilized total knee arthroplasty can be highly successful.
authors.affiliation: Department of Orthopaedic Surgery, University of North Carolina School of Medicine, Chapel Hill 27599-7055, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Larson
authors.forename: P F
authors.initials: PF
authors.lastname: Lachiewicz
mesh_terms: D000368:Aged; D018771:Arthralgia / Q000453:epidemiology; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects* / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology; D007720:Knee Prosthesis / Q000009:adverse effects*; D008297:Male; D010329:Patella; D011446:Prospective Studies; D011474:Prosthesis Design; D016059:Range of Motion, Articular; D013997:Time Factors; D016896:Treatment Outcome