The need for a better understanding of factors that influence surgical outcome has grown as many complications are thought to be avoidable. One approach proven useful in studying surgical procedures is time-action analysis (TAA), a method which objectively determines the efficiency of individual steps. The aim of this study was to assess the surgical process of total knee arthroplasty using TAA, thus enhancing the insight into the procedure, influence of team members and adverse events, eventually leading to process improvement and reduction of error probability.
Methods: In two high output centres and one teaching hospital 37 TKA surgeries were recorded, using 3 different knee systems (NexGen, LCS and Triathlon). The process was analyzed using a fixed taxonomy and the duration, limitations and repetitions were determined using video analysis software. The efficiency of the surgeon was calculated by dividing the time the surgeon spends operating by the time operating plus the time spent talking, thinking or repeating.
Results: Although the two high output centres used different knee systems there was no difference in operating time (47min. (95%CI, 43.2 to 50.1) versus 47min. (42.1 to 51.9)). With an inexperienced nurse the waiting time increased in both hospitals during the femoral osteotomy phase (p= 0.01 and p=0.05). Comparing to a training hospital, the tibial alignment phase showed lower surgical efficiency for both the consultant and 6th year residents (80% vs. 95%, p=0.01). Also the nurse waiting time increased during all phases (18min. vs. 2min., p=0.00). In the teaching hospital more problems (communication, instrument and skill) occurred (mean 19 vs. 5 and 2, p=0.00) and twice as much communication problems existed with residents regardless of nurse experience. Surprisingly the number of problems handling instruments increased inversely with nurse experience (p=0.02) as did the waiting time (27min. vs. 15min.) again being highest in the femoral osteotomy phase (p=0.00).
Conclusion: The similar results in the high output centres show that TKA is a similar and structured process regardless of the knee system, its efficiency mainly dependent on surgical output. The decrease in resident efficiency is caused by less structured use of instruments and miscommunication with the nurse. For nurses the femoral osteotomy phase is most difficult, requiring high attention due to frequent changing of different pins and cutting blocks. Unfamiliarity with instruments (i.e. low volume) results in higher waiting times. Regardless of the knee system the steps of TKA are similar, therefore a consistent surgeon-nurse (OR tech) verbal interaction is advocated especially with a less experienced team. Training should focus knowledge of instruments using uniform names. Extra attention should be paid by those who do not often place knees to communication with the nurse and clear order of the procedure.
