High 10-Year Survival Rate with an Anatomic Cementless Stem (SPS)

Abstract

BackgroundProximal cementless fixation using anatomic stems reportedly increases femoral fit and avoids stress-shielding. However, thigh pain was reported with the early stem designs. Therefore, a new anatomic cementless stem design was based on an average three-dimensional metaphyseal femoral shape. However, it is unclear whether this stem reduces the incidence of thigh pain.Questions/purposesWe asked whether this stem design was associated with a low incidence of thigh pain and provided durable fixation and high function.MethodsOne hundred seventy-one patients (176 THAs) who had the anatomic proximal hydroxyapatite-coated stem implanted were reviewed. Eleven (6%) patients were lost to followup and 34 (20%) died without revision surgery. We used the Harris hip score (HHS) to assess pain and function. We evaluated femoral stem fixation and stability with the score of Engh et al. and also calculated a 10-year survival analysis. We assessed 126 patients (131 hips) at a mean followup of 10 years (range, 8–11 years)ResultsAt last followup, two patients described slight thigh pain that did not limit their physical activities. All stems appeared radiographically stable and one stem was graded nonintegrated but stable. Five patients had revision surgery: one on the femoral side (for posttraumatic fracture) and four on the acetabular side. Considering stem revision for aseptic loosening as the end point, survivorship was 100% (range, 95.4%–99.9%) at 10 years.ConclusionThis anatomic cementless design using only metaphyseal fixation with a wide mediolateral flare, a sagittal curvature, and torsion, allowed durable proximal stem stability and fixation.Level of EvidenceLevel IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Is the Bone-bonding Ability of a Cementless Total Hip Prosthesis Enhanced by Alkaline and Heat Treatments?

“…First, survival rates of recent THA implants are so high [6,12,31,34,35] that the number of hips and length of followup of this study are not sufficient to reveal the superiority of this implant. Although larger cohorts and longer followups would be necessary to confirm whether this implant enhances bone bonding and survival, it was associated with a high survival rate.…”

Results of a hydroxyapatite-coated femoral stem (Corail) in Chinese: a minimum 10-year follow-up

“…Compared with porous alone femoral stems, HA stems demonstrated better result with less adverse effects (Epinette and Manley 2008). Sariali et al (2012) reported that the survivalship of anatomic cementless stem (SPS) was 100% considering stem revision for aseptic loosening as the end point. Antonio Herrera et al reported their surgical experience with more than 4000 cementless hydroxyapatite coated hip prostheses (the ABG I and ABG II prosthesis an anatomical HA-coated stem with press-fit metaphyseal fixation, Stryker) since 1990.…”

CORR Insights®: Two- to 4-year Followup of a Short Stem THA Construct: Excellent Fixation, Thigh Pain a Concern

“…Although 10 year-to 16 year-survival rates have been reported with short stems [4,7,9], we need stronger evidence to determine whether short stems represent a safe alternative to traditional long-stem designs. It is my hope that a national joint registry, such as the American Joint Replacement Registry, and international joint registries, such as the Nordic Arthroplasty Register Association will help to confirm these findings, as well as determine the risk factors associated with shortstem THA failures.…”

“…The longest followup studies (10 years or longer) have been reported for short femoral implants either with a tight metaphyseal design [7,9] or with a neck-preserving concept [4,5], in patients with a mean age of 52 years to 73 years. Using these systems, researchers found acceptable stem revision rates (0% to 3.4%) for aseptic loosening [4,5,7,9].…”