RESUMO
Purpose: to systematically review comparative studies reporting revision rates, clinical outcomes, or radiographic outcomes of total hip arthroplasty (THA) using collared versus collarless conventional-length uncemented hydroxyapatite (HA)-coated stems. Methods: In adherence with PRISMA guidelines, a literature search was performed on Medline, Embase, and Scopus. Comparative clinical studies were eligible if they reported outcomes of collared versus collarless uncemented HA-coated stems for primary THA. Two reviewers screened titles, abstracts, and full-texts to determine eligibility; then performed data extraction; and assessed the quality of studies according to Joanna Briggs Institute (JBI) checklist. Results: The search returned 972 records, 486 were duplicates, and 479 were excluded after title/abstract/full-text screening. Three further studies were included from the references of eligible studies and from discussions with subject matter experts, resulting in 11 included studies. The JBI checklist indicated six studies scored ≥7 points and four studies ≥4 points. Pooled data revealed collared stems had significantly lower revision rates (OR = 0.45; 95% CI = 0.31-0.64) and subsidence (MD = -1 mm; 95% CI = -1.6--0.3), but no significant difference in intraoperative complication rates (OR = 0.94; 95% CI = 0.67-1.32) in the short term to mid-term. Unpooled data indicated that collared stems provide equivalent survival, equivalent or better outcomes, and equivalent or lower complication rates. Conclusion: In comparative studies, collared stems have lower revision rates than collarless stems, as well as equivalent or better clinical and radiographic outcomes. Differences could be due to a protective effect that the collar offers against subsidence, particularly in undersized or misaligned stems. Further studies are warranted to confirm long-term results and better understand differences between registry data and clinical studies.
RESUMO
PURPOSE: To compare the biomechanical behavior of vertebrae with vertebral compression fractures (VCF) treated by a novel system with pedicular anchorage (dowelplasty) versus balloon kyphoplasty. METHODS: Four cadaveric spines (T12-L5) were harvested, cleaned from soft tissues, and separated into vertebrae. Axial compressive loads were applied to each vertebra until a VCF was generated. Half of the vertebrae (n = 11) were instrumented using the "dowelplasty" system, consisting of a hollow titanium dowel anchored into the pedicle, through which a cannulated titanium nail is inserted and locked and through which cement is injected. The other half (n = 11) were instrumented using balloon kyphoplasty. Axial compressive loads were re-applied to each vertebra until fracture. Fracture load and fracture energy were calculated from load-displacement data for the pre- and post-treatment states. RESULTS: Compared to balloon kyphoplasty, dowelplasty granted greater net change in fracture load (373N; 95%CI,-331-1076N) and fracture energy (755Nmm; 95%CI,-563-2072Nmm). A sensitivity analysis was performed without L4 and L5 vertebrae from the dowelplasty group, since the length of the cannulated nails was too short for these vertebrae: compared to balloon kyphoplasty, dowelplasty granted an even greater net change in fracture load (680N; 95%CI,-96-1457N) and fracture energy (1274Nmm; 95%CI,-233-2781Nmm). CONCLUSION: Treating VCFs with dowelplasty grants increased fracture load and fracture energy compared to the pre-treatment state. Furthermore, dowelplasty grants greater improvement in fracture load and fracture energy compared to balloon kyphoplasty, which suggests that dowelplasty may be a good alternative for the treatment of VCF. LEVEL OF EVIDENCE: level IV.
