ABSTRACT
We examined the incidence of heterotopic ossification (HO) in a consecutive series of total hip arthroplasties (THAs) performed with the so-called minimally invasive, 2-incision technique. Standard preoperative hip radiographs were used to grade the extent of degenerative arthritis, and comparable follow-up radiographs at 30 months after surgery were used to detect and classify HO formation. Of 121 patients, 32 (26.5%) developed HO, with the Brooker class distribution as follows: stage I, 16 patients; stage II, 9 patients; stage III, 6 patients; stage IV, 1 patient. In this study, HO formation after 2-incision THA occurred with nearly the same frequency as that reported in other studies after standard THA.
Subject(s)
Arthroplasty, Replacement, Hip/adverse effects , Ossification, Heterotopic/diagnostic imaging , Osteoarthritis, Hip/surgery , Female , Hip Joint/surgery , Humans , Male , Middle Aged , Minimally Invasive Surgical Procedures , Ossification, Heterotopic/etiology , Osteoarthritis, Hip/diagnostic imaging , RadiographyABSTRACT
The most common previously reported modes of failure of unicompartmental knee arthroplasty (UKA) in the first and second decades are polyethylene wear, progression of arthritis, and component loosening. The purpose of this study is to describe an early mechanism of failure of the medial UKA. Thirty-two consecutive revisions from UKA to total knee arthroplasty were retrospectively reviewed. The predominant mode of failure observed in 15 (47%) of 32 knees was medial tibial collapse. Of these, 87% were an all-polyethylene design, and 7 of 15 failed in less than 16 months and required more complex reconstruction with stems, augments, and screws and cement. Increased tibial slope was associated with posterior tibial collapse. In our series, knees that failed by medial tibial collapse had more significant bone defects and required more complex reconstructions than is currently reported in the literature.
Subject(s)
Arthroplasty, Replacement, Knee/instrumentation , Knee Prosthesis , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Postoperative Complications , Prosthesis Design , Prosthesis Failure , ReoperationABSTRACT
This article presents the 2-year clinical results of primary total knee arthroplasty (TKA) performed with a zirconia ceramic femoral component. A posterior-stabilized TKA was performed for degenerative arthritis in 36 patients (39 knees). The components included a zirconia femoral component, a cobalt-chrome alloy tibial baseplate, and a polyethylene patella; all were implanted with bone cement. The ultra-high molecular-weight polyethylene-bearing insert had a deep-dish, ultra-congruent design. At the 2-year interval, mean Western Ontario and McMaster Universities (WOMAC) osteoarthritis indices improved from 41 to 86, and mean Knee Society Scores improved from 40 to 92. Revision to constrained implants was necessary in one patient for persistent knee instability after trauma. These early results are encouraging, but more data are needed to determine whether ceramics are a suitable alternative to metal countersurfaces in TKAs.
