Pelvic flexion and extension in different body positions can affect acetabular orientation after total hip arthroplasty, and this may predispose patients to dislocation. The purpose of this study was to evaluate functional acetabular component position in total hip replacement patients during standing and sitting. We hypothesize that patients with degenerative lumbar disease will have less pelvic extension from standing to sitting, compared to patients with a normal lumbar spine or single level spine disease. A prospective cohort of 20 patients with primary unilateral THR underwent spine-to-ankle standing and sitting lateral radiographs that included the lumbar spine and pelvis using EOS imaging. Patients were an average age of 58 ± 12 years and 6 patients were female. Patients had (1) normal lumbar spines or single level degeneration, (2) multilevel degenerative disc disease or (3) scoliosis. We measured acetabular anteversion (cup relative to the horizontal), sacral slope angle (superior endplate of S1 relative to the horizontal), and lumbar lordosis angles (superior endplates of L1 and S1). We calculated the absolute difference in acetabular anteversion and the absolute difference in lumbar lordosis during standing and sitting (Figure 1).Introduction
Methods
Whole blood metal ion level and clinical outcomes of ceramic-on-metal bearing were comparable to ceramic-on-ceramic THA in this prospective randomized controlled trial. We randomized 150 consecutive THA cases at one institution into two groups: Group I and Group II. Group I, 75 cases, received a THA using ceramic-on-metal couplings and Group II, 75 cases, received ceramic-on-ceramic bearing THA. The implant differed only in the bearing surfaces used. We compared the serum levels of cobalt (Co) and chromium (Cr) and functional outcome scores preoperatively, and at 2, 6, and 12 months postoperatively.Introduction:
Methods:
Complete wear-out of Polyethylene (PE) liner results in severe metallosis following articulation of the artificial head with the acetabular metal shell. We postulated that an adverse response can be led to surrounding bone tissue and new implant after revision surgery because the amount of PE wear particle is substantial and the metal particles are infiltrated in this catastrophic condition. We evaluated clinical characteristics and the survival rate of revision total hip arthroplasty (THA) performed in patients with severe metallosis following failure of PE liner. Between January 1996 and August 2004, severe metallosis following complete wear-out of PE liner were identified during revision THA in 28 hips of 28 patients. One patient had died at 7 days after surgery and 3 patients could not be reached at 5 year follow-up. Twenty-four hips of 24 patients (average age, 47.5 years) were followed for at least 6.5 years (average, 11.3 years; range, 6.5–15.9 years) and were evaluated. The mean time interval between prior surgery and the index revision surgery was 9.6 years (range, 4.0–14.3 years). The indications for revision surgery were osteolysis around well-fixed cup and stem in 22 hips and osteolysis with aseptic loosening of the cup in 2 hips. Bubble sign was observed on preoperative radiograph in 10 hips. Total revision, cup revision, and solitary bearing change were performed in 13, 10, and one hip respectively. A cementless implant was used in 23 hips and acetabular reinforcement ring was used in one. Clinical evaluation was performed using Harris hip scores and Kaplan-Meier survival analysis was performed. Multivariate analysis was performed with age, gender, BMI, bone defect type, existence of bubble sign and type of revision surgery as variables to evaluate the association with osteolysis or loosening.Purpose
Materials and Methods
Melorheostosis is a very rare mesenchymal dysplasia of bone, characterized by sclerosing hyper-pigmentation appearances on the bone, may involve the adjacent soft tissues and lead to joint pain, limitation of joint motion and stiffness as a result of abnormal ossifications and soft tissue contractures, due to periarticular fibrosis. It is well known to tend to affect only one limb, but multifocal involvement, such as multiple limbs, spine and rib, has been extremely rarely reported. A variety of treatment options have been tried so far, none being specific surgical treatments. Here we present a case of a 43-year-old man who sustained melorheostosis with multifocal involvement including the axial skeleton and a whole entire lower limb. He had painful swelling of his left lower limb and mainly complained of difficulty walking due to severe hip pain and knee stiffness, which persisted for 20 years and was aggravated during the last 5 years. Total hip arthropasty [Fig. 1] was done first, and then total knee arthroplasty [Fig. 2, 3] was performed. During operation, there were difficulties in bone cutting and implant insertion due to mixed pattern of hard sclerotic portion and osteoporotic portion despite complete synovectomy and sufficient soft tissue release. He was eventually free of pain during walking and able to walk without a crutch and joint motion of hip and knee was substantially improved after surgery. We found that hip pain and contracture due to osteoarthritis and knee contracture secondary to multifocal melorheostosis could be successfully treated by total hip and knee arthroplasty. To the best of our knowledge, this is the first reporting the total joint arthroplasty performed in the patients with multifocal melorheostosis.
