title: Navigated "small implants" in knee reconstruction.
abstract: OBJECTIVE
  At the beginning of this century, unprecedented interest in the concept of using less invasive approaches for the treatment of knee degenerative diseases was ignited. Initial interest in this approach was about navigated and non-navigated knee reconstruction using small implants and conventional total knee arthroplasty.
  
  
  METHODS
  To this end, a review of the published literature relating to less invasive compartmental arthroplasty of the knee using computer-based alignment techniques and on soft tissue-dedicated small implants is presented. The authors present and compare their personal results using these techniques with those reported in the current literature. These involved the use of a shorter incision and an emphasis sparing. However, nowadays most surgeons look at compartmental knee resurfacing with the use of small implants as the new customized approach for younger and higher-demand patients. The aim of this paper is to stimulate further debate.
  
  
  RESULTS
  Since the beginning of 2000, computer-assisted surgery has been applied to total knee arthroplasty (TKA) and later to compartmental knee arthroplasty. Recent studies in the literature have reported better implant survivorship for younger patients using navigation in TKA at longer-term follow-up. Only one published report was identified showing superior clinical outcomes at short-term follow-up using computer-assisted technology compared with conventional alignment techniques in small implant surgery. No studies were found in the literature that demonstrated similar clinical advantages with navigated small implants at long-term follow-up. Two published meta-analyses were identified reporting better implant and limb alignment and no increase in complications using a navigated unicompartmental knee arthroplasty. However, neither meta-analysis showed superior clinical outcomes or survivorship with the navigated techniques.
  
  
  CONCLUSIONS
  In conclusion, we can assert that replacing just the damaged compartment and preserving the normal biomechanics will require not only new implant designs but also new technologies allowing the surgeon to make extremely precise adjustments to implant alignment and providing continuous feedback during surgery.
  
  
  METHODS
  IV.
authors.affiliation: 1st Orthopaedic and Trauma Department, CTO Hospital, ASST G. Pini-CTO, Milan, Italy. Norberto.confalonieri@gmail.com.
authors.forename: Norberto
authors.initials: N
authors.lastname: Confalonieri
authors.affiliation: 1st Orthopaedic and Trauma Department, CTO Hospital, ASST G. Pini-CTO, Milan, Italy.
authors.forename: Alessio
authors.initials: A
authors.lastname: Biazzo
authors.affiliation: Department of Electronics, Information and Bioengineering, Politecnico di Milano, 20100, Milan, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Cerveri
authors.affiliation: Orthopaedic Department, Royal Melbourne Hospital, Parkville, VIC, Australia.
authors.forename: Chris
authors.initials: C
authors.lastname: Pullen
authors.affiliation: Orthopaedic and Trauma Department, "Luigi Sacco" Hospital, ASST FBF-Sacco, Milan, Italy.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Manzotti
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D006801:Humans; D007719:Knee Joint / Q000601:surgery*; D007720:Knee Prosthesis; D011474:Prosthesis Design; D025321:Surgery, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome
keywords: Bi-unicompartmental knee arthroplasty; Computer-assisted surgery; Patello-femoral arthroplasty; Small implants; Soft-tissue-sparing surgery; Tri-unicompartmental knee arthroplasty; Unicompartmental knee arthroplasty