Comparison of Power Tool Modes Used for Kirschner Wire Driving: Forward & Reverse (F&R) Mode – Oscillation Mode

Kirschner Wire Driving Modes - Comparison of Power Tools

The forward & reverse (F&R) modes (Kirschner Wire Driving Modes) of the power tool are used while drilling with surgical power tools in orthopedic operations. In this mode, the direction of rotation can be changed to right (forward) and left (reverse) with the help of a button.

The driving of the Kirschner wire can be done in the F&R mode with the help of the wire driver attachment. However, some of the surgical power tools offer a special mode for this procedure (oscillation mode). In oscillation mode, the direction of rotation changes automatically as one right and one left.

Comparison of the two modes in terms of heat generation

Anderson et al. (2018) investigated the effect of these modes on the heat generated on bone. ANOVA test results in the trials were as follows; When using a 0.062 inch Kirschner wire, the average temperature increase in F&R mode and oscillation mode is 14.0 ± 5.5 ° C and 8.8 ± 2.6 ° C, respectively. In case 0.045 inch Kirschner wire is used, the average temperature increase in F&R mode and oscillation mode is 11.4 ± 2.6 ° C and 7.1 ± 1.9 ° C, respectively.

As a result of this experiment, it can be concluded that the oscillation mode generates less heat and causes less thermal necrosis on the bone. But, a more comprehensive study in this area by Luo et al. in 2019 revealed that there is no difference between these two modes in terms of the risk of bone necrosis.

In the experiment conducted by Luo et al. (2019), they compared the highest temperature obtained and the time to perform the desired drilling process for two modes. In the ANOVA test, 95 successful trials showed a lower temperature peak point in oscillating mode than in F&R mode again. But when looking at the drilling times, the F&R mode is finished the drilling process in a much shorter time than oscillation mode. (Figure 1)

Figure 1: Impact of drilling mode on: (a) peak bone temperature and (b) drilling time (error bar represents standard deviation). (Luo et al., 2019)

ANOVA results show that the oscillation drill mode produces 13% lower average peak bone temperature increase than the F&R mode and has a 46% longer drilling time. Since the oscillation drilling mode has a lower average angular velocity due to the periodical oscillations of the surgical motor, the rotational power and heat generation rate is lower. But since it does not constantly turn to the same direction, the speed of removing bone material is lower. Although it has a lower peak temperature, it is exposed to temperature rise for a longer time due to the longer drilling time. (Luo et al., 2019)

As a result, shortening the drilling time will be the primary goal for surgeons. The first thing that comes to mind about shortening this period is to increase the thrust force. In the trials in Luo’s experiment, in both drilling modes, excessive thrust force increased the risk of breaking / burning bone and bending of the K-wire. High thrust force could also result in plunging the K‐wire into surrounding soft tissue after penetrating the bone, which leads to collateral tissue injury. (Gao Y. et al., 2017). In view of these results, Luo et al. recommend applying moderate thrust in both drilling modes.

What are the most common drilling methods are used by surgeons?

Luo et al. tried 4 techniques used by surgeons in K-wire insertion procedures. (2019)

  • Continuous drilling: It is to continuously thrust the K-wire towards the bone with an increasing thrust force. This method further increased heat generation by creating higher friction force and excessive tool wear. This method is shown in Figure 2 in red.
  • Shaky drilling: In this drilling technique, the surgeon performs the wire driving process by making small vibrations back and forth in the axis of the K-wire. This method is shown in Figure 2 in green. This method helped to reduce heat by helping to evacuate bone debris. Even if you try to thrust continuously in the oscillation mode, this is impossible because the direction of rotation will reverse, and it will be an example of shaky drilling. Therefore, it could not be shown in red in the continuous drilling section in the oscillation mode graph in Figure 2.
  • Intermitten drilling: Surgeons created one or two notches in the thrust profile, such as the blue curves in Figure 2, by gently retracting the surgical power tools once or twice during drilling. Evacuation of bone debris was done more efficiently. With this technique, surgeons achieved the fastest drilling time and the lowest increase in bone temperature. (In F&R mode)
  • Pecking drilling: Surgical power tool retraction is performed more frequently by the surgeon. It is shown as a black line in Figure 2. Multiple notches in the thrust force applied to the surgical motor during piercing (in other words pushing and retracting too much of the power tool) were not efficient due to prolong the drilling time. Since the time is prolonged, the contact time of the heat with bone has increased.

Figure 2 : Four types of drilling techniques utilized by different surgeons under (a) F&R and (b) oscillation drilling modes. (Luo et al., 2019)

According to the results, continuous and pecking drilling methods should not be preferred for shorter drilling time and less heat generation.

Kirschner Wire Driving Modes - Evaluation

The oscillation mode did not gain an advantage over the F&R mode in terms of temperature increase in the bone. It can even be said that the F&R mode is more advantageous in terms of shorter drilling time. The most efficient result was obtained with the intermittent drilling method for both modes. Whichever mode is used, the surgeon’s guidance and the drilling method used by surgeon will be very effective to prevent necrosis in bone cells.

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  • Scott Richard Anderson, Serkan Inceoglu and Montri D. Wongworawat. 2018. Temperature Rise in Kirschner Wires Inserted Using Two Drilling Methods: Forward and Oscillation. American Association for Hand Surgery. Vol. 13(4) 423–427
  • Yuanqiang Luo, Lei Chen, Fred T. Finney, Dae Woo Park, Paul G. Talusan, James R. Holmes, Albert J. Shih. 2019. Evaluation of Heat Generation in Unidirectional Versus Oscillatory Modes During K‐Wire Insertion in Bone. Orthopaedic Research Society. Published online in Wiley Online Library ( DOI 10.1002/jor.24345
    • Gao Y, Wang Q, Zhu H, Xu Z. 2017. Timing for surgical stabilization with K‐wires after open fractures of proximal and middle phalangeal shaft. Sci Rep 7:31–34.

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