Total knee arthroplasty in patients with substantial deformities using primary knee components

Knee Surg Sports Traumatol Arthrosc. 2015 Dec;23(12):3653-9. doi: 10.1007/s00167-014-3269-x. Epub 2014 Sep 24.

Abstract

Purpose: Although advocated for severe varus and valgus deformities, constrained implant designs are associated with a number of disadvantages in total knee arthroplasty (TKA). Combining a minimally invasive surgical approach with an interchangeable posterior stabilized (PS) implant design may allow adequate soft tissue balancing with a minimal amount of constraint and without residual instability.

Methods: Retrospectively 51 patients operated with the minimally invasive far medial subvastus approach for severe varus or valgus deformity, who underwent primary TKA with a fully interchangeable PS implant (Vanguard, Biomet Inc., Warsaw IN, USA) between 2009 and 2013 were examined. Soft tissue releases was performed using a piecrust needling technique. Preoperative alignment and surgical parameters were collected for all patients. All patients underwent preoperative and follow-up radiographic assessment and completed a battery of clinical assessments.

Results: All procedures were performed successfully, with alignment improving from a preoperative mean (SD) varus deformity of 165° (3°) and a mean (SD) valgus deformity of 196° (4.5°) to an overall mean (SD) postoperative mechanical alignment of 179.5° (3.0°). Nine patients had postoperative varus, while three patients had a postoperative valgus deviation from neutral alignment >3°. The mean change in joint line position in extension was -0.0 ± 0.6 mm. Clinical scores at final follow-up were excellent for both groups.

Conclusions: Good TKA outcomes can be achieved in patients with substantial varus or valgus deformities using a combination of a minimally invasive far medial subvastus approach, interchangeable PS implants and soft tissue releases with a piecrust needling technique.

Level of evidence: III.

Keywords: Joint deformity; Minimally invasive surgery; Posterior stabilized; Prosthesis design; Total knee arthroplasty.

MeSH terms

  • Adult
  • Aged
  • Arthroplasty, Replacement, Knee / instrumentation
  • Arthroplasty, Replacement, Knee / methods*
  • Female
  • Humans
  • Knee Joint / pathology*
  • Knee Joint / surgery*
  • Male
  • Middle Aged
  • Minimally Invasive Surgical Procedures / instrumentation
  • Minimally Invasive Surgical Procedures / methods*
  • Osteoarthritis, Knee / pathology*
  • Osteoarthritis, Knee / surgery*
  • Postoperative Period
  • Prosthesis Design
  • Retrospective Studies