Abstract
Femoral neck-preserving short- (NPS) stem implants for total hip arthroplasty (THA)
bear several advantages over longer-stem implants, such as native hip structure preservation
and improved physiological loading. However, there still is a gap of knowledge regarding
the potential benefits of a short-stem design over conventional neck-sacrificing stems
in regards to patient-reported outcomes (PROs). The authors investigated the differences
in PROs between a neck-sacrificing stem design and NPS stem design arthroplasty. They
hypothesized that PROs of NPS stem THA would be higher in the medium-term in comparison
to the neck-sacrificing implant system. Neck-sacrificing implant patients (n = 90, age 57 ± 7.9 years) and a matched (body mass index [BMI], age) cohort group
of NPS implant patients (n = 105, age 55.2 ± 9.9 years) reported both preoperative and postoperative hip disability
and osteoarthritis outcome scores (HOOS). Average follow-up was 413 ± 207 days (neck
sacrificing implant) and 454 ± 226 days (NPS implant). The authors applied multivariate
analysis of variance (MANOVA) and Mann–Whitney tests for statistical analyses. Significance
levels were Holm–Bonferroni adjusted for multiple comparisons. HOOS Subscores increased
significantly after surgery independent of implant type (p < 0.001). There was a significant time by surgery interaction (p = 0.02). Follow-up HOOS subscores were significantly higher in the NPS implant group:
symptoms (p < 0.001), pain (p < 0.001), activities of daily living (ADL; p = 0.011), sports and recreation (p = 0.011), and quality of life (QOL; p = 0.007). While long-term studies are required for further investigation, evidence
from the current study suggests that NPS implants may provide a significant benefit
to primary THA patients, which could be due to physiological loading advantages or
retention of bone tissue.
Keywords total hip arthroplasty - neck-preserving - patient-reported outcomes