Abstract
In recent years, the progressive technology of hemodialysis provides long-term survival for renal failure patients. On the other hand, avascular necrosis of the femoral head from the use of steroids or renal osteodystorophy or femoral neck fracture due to amyloid arthropathy have increased. In such cases, bipolar femoral head prosthesis (FHP) and total hip replacement (THR) are usually performed. But it is at risk of developing severe complications, such as early loosening or infection of the implant.
The aim of this study is to evaluate the stability of the cementless stems in radiograms and clinical results after FHP or THR using three types cementless prosthesis in hemodialysis patients.
The study included 14 patients (19 hips) on hemodialysis who underwent FHP or THR using three types cementless prosthesis at our institution between 1983 to 2005 and we could follow up at least two years. There were 8 women (11 hips) and 6 men (8 hips) with an average age of 43.9 years (range, 20–88). The average follow-up was 6.75 years. The average hemodialysis term was 10.5 years. Three types of hip prosthesis (7 stems were CLS, 6 stems were IMC, 6 stems were Duetto S-I) has been used for the treatment at our institution in the past. The initial diagnosis was avascular necrosis of the femoral head in 8 hips, femoral neck fracture in 5, osteoarthritis in 4 and amyloid arthropathy in two. We assessed at least 3° of varus-valgus deviation or at least 3 mm of subsidence as aseptic loosening of stems, and assessed radiolucent line and stress shielding of the stems in radiograms, also. As for clinical results, we measured postoperative infection rate and revision rate.
Aseptic loosening of stems were identified in 3 hips (15.8%). Radiolucent lines were identified in 5%–26% of hips categolised by Gruen’s classification zone I-VII, although their zones differed according to the stem model. Stress shieldings were identified in 10 hips (53%), most of which were level 1, according to the criteria described by Engh et al. Infection rate and revision rate were 5.3% (1 hip) and it was a long-term hemodialysis patient.
Several studies report, there is a high probability that early loosening of the stems is associated with amyloid deposition. We experienced early loosening of the stems in our case and considered prevention of amyloid deposition very important in improving the prognosis of the arthroplasty. We must follow carefully hemodialysis patients after an operation because their nutrition level is low and their bodies are compromised due to steroids use and their postoperative infection rate is high.
Correspondence should be addressed to Diane Przepiorski at ISTA, PO Box 6564, Auburn, CA 95604, USA. Phone: +1 916-454-9884; Fax: +1 916-454-9882; E-mail: ista@pacbell.net
