Is computer-assisted total knee replacement for beginners or experts? Prospective study among three groups of patients treated by surgeons with different levels of experience

Abstract

BackgroundComputer-assisted total knee replacement (TKR) has been shown to improve radiographic alignment and therefore the clinical outcome. Outliers with greater than 3° of varus or valgus malalignment in TKR can suffer higher failure rates. The aim of this study was to determine the impact of experience with both computer navigation and knee replacement surgery on the frequency of errors in intraoperative bone cuts and implant alignment, as well as the actual learning curve.Materials and methodsThree homogeneous groups who underwent computer-assisted TKR were included in the study: group A [surgery performed by a surgeon experienced in both TKR and computer-assisted surgery (CAS)], B [surgery performed by a surgeon experienced in TKR but not CAS], and C [surgery performed by a general orthopedic surgeon]. In other words, all of the surgeons had different levels of experience in TKR and CAS, and each group was treated by only one of the surgeons. Cutting errors, number of re-cuts, complications, and mean surgical times were recorded. Frontal femoral component angle, frontal tibial component angle, hip–knee–ankle angle, and component slopes were evaluated.ResultsThe number of cutting errors varied significantly: the lowest number was recorded for TKR performed by the surgeon with experience in CAS. Superior results were achieved in relation to final mechanical axis alignment by the surgeon experienced in CAS compared to the other surgeons. However, the total number of outliers showed no statistically significant difference among the three surgeons. After 11 cases, there were no differences in the number of re-cuts between groups A and C, and after 9 cases there were no differences in surgical time between groups A and B.ConclusionA beginner can reproduce the results of an expert TKR surgeon by means of navigation (i.e., CAS) after a learning curve of 16 cases; this represents the break-even point after which no statistically significant difference is observed between the expert surgeon and the beginner utilizing CAS.

Radiological and Functional Outcomes in Computer Assisted Total Knee Arthroplasty Between Consultants and Trainees — A Prospective Randomized Controlled Trial

“…Immediate visual feedback that allows real time adjustments of cutting blocks means implants can be positioned with great accuracy and precision [1,27]. This in turn leads to less cutting errors and alignment outliers [1,22,25,27]. Our study has shown that these benefits can translate to good medium-term clinical function of TKA even in surgery performed by less experienced hands.…”

“…In other studies where similar comparisons have been performed, after 11-30 cases operative time differences have been seen to equalize. This is considered an acceptable learning curve for this procedure [1,22,26,27]. CAS allows trainees to achieve 5-year functional results with TKA that are comparable to a consultant surgeon experienced in the use of CAS at mid-term follow-up.…”

“…[1,[21][22][23][24][25][26][27] Post-operative alignment was comparable between the two groups (P = 0.15), as were blood loss and length of incision (P = 0.45 and 0.78 respectively). Using CAS the trainees group were able to perform a similar TKA operation to the consultant group.…”

Frontal plane alignment after total knee arthroplasty using patient-specific instruments

“…Secondly, the operating surgeon undertakes a high volume of TKAs annually, and it is possible that this level of experience positively influenced the results. The learning curve for beginner surgeons has been shown to be acceptably low with computer-assisted navigation systems, with the exception of a general increase in operative and tourniquet times during initial cases [21][22][23]. Additional research is required, however, to ascertain whether lessexperienced surgeons would encounter a similar learning curve with this particular PSI technology.…”

(vii) Role of Computer Assisted Surgery (CAS) in Training and Outcomes

“…CAS) after a learning curve of 16 cases; this is called the breakeven point after which no statistically significant difference in surgical time is observed between the expert surgeon and the beginner using CAS. 20 In 2013, Nicholson et al raised an interesting issue regarding the "re-learning curve for conventional total knee arthroplasty following 30 consecutive computer assisted total knee arthroplasties". 21 A "re-learning curve" of 30 conventional TKAs was necessary to attain an average postoperative mechanical axis statistically indistinguishable from the average CAS mechanical axis (1.99 ).…”