Intra-Operative Soft Tissue Targets For Improved Outcomes In Total Knee Arthroplasty

5 pages•Published: September 25, 2020

Edgar Wakelin, Sami Shalhoub, Jeffrey Lawrence, John Keggi, Jeffrey DeClaire, Amber Randall, Corey Ponder, Jan Koenig and Christopher Plaskos

Abstract

A poorly balanced, unstable or stiff joint is a leading cause of dissatisfaction and revision after surgery. The quantitative definition of a well-balanced joint, however, remains a source of controversy. This study investigates joint gaps measured by a digitally-controlled ligament tensioning device throughout flexion and its effect on post- operative outcome.
Surgeries were performed using the OMNIBotics robot-assisted TKA platform and BalanceBot device. Joint gaps were recorded by the BalanceBot throughout flexion during trialing. Knee Injury and Osteoarthritis Outcome Score (KOOS) was collected at 1-year post-op. Correlations between joint gaps and KOOS outcome were investigated.
Knees that reported: a medial gap ≤ lateral gap in extension (p = 0.007, median ∆ = 8.3); an average joint gap of between 1 mm tighter and 1 mm looser than the final insert thickness in midflexion (p = 0.006, median ∆ = 5.5); and an imbalance of less than 1.5 mm in flexion (p = 0.012, median ∆ = 2.8) reported significantly improved pain scores. Patients which satisfied both extension and flexion criteria, or midflexion and flexion criteria reported improved outcomes compared to those which satisfied only one or neither criterion (p = 0.0002, median ∆ = 9.7, p = 0.0019, median ∆ = 8.4 respectively).
KOOS Pain scores correlated with joint gap measurements across all flexion angles investigated. Combining joint gap windows, subgroups of patients were found that reported a change in the median KOOS Pain outcome beyond the minimally clinically important difference.

Keyphrases: alignment, joint balance, knee, ligament tension, total knee arthroplasty

In: Ferdinando Rodriguez Y Baena and Fabio Tatti (editors). CAOS 2020. The 20th Annual Meeting of the International Society for Computer Assisted Orthopaedic Surgery, vol 4, pages 283-287.

Links:	https://easychair.org/publications/paper/LSfV
	https://doi.org/10.29007/3plz

BibTeX entry

@inproceedings{CAOS2020:Intra_Operative_Soft_Tissue,
  author    = {Edgar Wakelin and Sami Shalhoub and Jeffrey Lawrence and John Keggi and Jeffrey DeClaire and Amber Randall and Corey Ponder and Jan Koenig and Christopher Plaskos},
  title     = {Intra-Operative Soft Tissue Targets For Improved Outcomes In Total Knee Arthroplasty},
  booktitle = {CAOS 2020. The 20th Annual Meeting of the International Society for Computer Assisted Orthopaedic Surgery},
  editor    = {Ferdinando Rodriguez Y Baena and Fabio Tatti},
  series    = {EPiC Series in Health Sciences},
  volume    = {4},
  publisher = {EasyChair},
  bibsource = {EasyChair, https://easychair.org},
  issn      = {2398-5305},
  url       = {/publications/paper/LSfV},
  doi       = {10.29007/3plz},
  pages     = {283-287},
  year      = {2020}}

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