Pre-operative planning in THA. Part III: do implant size prediction and offset restoration influence functional outcomes after THA?

Arch Orthop Trauma Surg. 2020 Apr;140(4):563-573. doi: 10.1007/s00402-020-03342-5. Epub 2020 Jan 23.


Introduction: Few studies evaluated clinical benefits of pre-operative templating in total hip arthroplasty (THA). We investigated whether mismatch between planned and real implant sizes and medio-lateral offsets compromises THA outcomes.

Materials and methods: We reviewed records of 184 primary THAs with pre-operative CT scans used for templating. Acetabular offset (AO), femoral offset (FO) and global offset (GO) were measured on pre-operative CT scans, during acetate templating, and post-operative antero-posterior radiographs. Multivariable analyses were performed to determine if Forgotten Joint Score (FJS) and Oxford Hip Score (OHS) at > 2 years were associated with differences between post-operative and planned parameters.

Results: The FJS and OHS were not influenced by mismatch of component sizes nor of FO and GO. The FJS was better when the post-operative AO was greater than planned (p = 0.050). The FJS differed among arthritic types (p = 0.015). Multivariable analyses confirmed that older patients had better OHS (beta - 0.16; p = 0.033) and FJS (beta 0.74; p = 0.002), medialized hips had worse FJS (beta - 20.1; p = 0.041) and hips with greater AO than planned had better FJS (beta 1.71; p = 0.024) CONCLUSIONS: Implanting a component of different size than planned did not compromise THA outcomes, but medialized hips had worse scores, and conservative acetabular reaming improved scores.

Keywords: Arthritis; Arthroplasty; Hip; Hip architecture; Pelvis and acetabulum; Pre-operative planning; Templating.

MeSH terms

  • Acetabulum / diagnostic imaging
  • Acetabulum / surgery
  • Arthroplasty, Replacement, Hip* / adverse effects
  • Arthroplasty, Replacement, Hip* / methods
  • Arthroplasty, Replacement, Hip* / statistics & numerical data
  • Femur / diagnostic imaging
  • Femur / surgery
  • Hip Joint / diagnostic imaging
  • Hip Joint / surgery
  • Hip Prosthesis* / adverse effects
  • Hip Prosthesis* / statistics & numerical data
  • Humans
  • Preoperative Care* / adverse effects
  • Preoperative Care* / methods
  • Preoperative Care* / statistics & numerical data
  • Tomography, X-Ray Computed
  • Treatment Outcome