Suture Anchors

On February 18, 2009, we performed a systematic search with the Google™ and Yahoo!^® search engines as these contain the largest set of Web pages [1 , 7 ]. Combinations of search terms were used: arthroscopy, simulator, orthopaedic, models, simulation, and trainer. A complementary search was performed in classification code G09B23/28 of the patent database Esp@cenet^®. Eight different physical and virtual reality arthroscopy simulators were commercially available. Companies were sent an invitation with the request to provide the simulator for 2 weeks at our institute. Two companies agreed to participate: Toltech Knee Arthroscopy Simulator (Touch of Life Technologies, Aurora, CO, USA) and InsightArthroVR^® Arthroscopy Simulator (GMV, Madrid, Spain). The other companies [6 , 9 (link), 19 , 21 , 25 , 29 , 30 ] refrained for various reasons unrelated to financial issues.
The Toltech Knee Arthroscopy Simulator (Simulator A) is a virtual reality simulator for arthroscopic knee surgery with two handles that give haptic feedback (Fig. 1) (Appendix 1). The InsightArthroVR^® Arthroscopy Simulator (Simulator B) is a virtual reality simulator for arthroscopic knee and shoulder surgery with a multitool that gives haptic feedback (Fig. 2) (Appendix 1).Fig. 1

A photograph shows a participant performing tasks on Simulator A.

Fig. 2

A photograph shows a participant performing tasks on Simulator B.

We recruited 37 participants, including (1) all staff members practicing arthroscopy routinely and present at the time of testing (except the main researcher GMMJK), (2) all residents present at the time of testing, and (3) medical students and researchers of our orthopaedic department. The participants were divided into three groups having different levels of arthroscopic experience: novices who had never performed an arthroscopic procedure, intermediates who had performed up to 59 arthroscopies, and experts who had performed more than 60 arthroscopies. This boundary level of 60 arthroscopies was based on the average opinion of fellowship directors who were asked to estimate the number of operations that should be performed to allow a trainee to perform unsupervised meniscectomies [24 (link)]. Simulator A was evaluated by 22 participants in April 2009 and Simulator B by 22 participants in October 2009 (Fig. 3). One participant had reached a higher level of experience between those times. The corresponding subgroups had similar characteristics (Fig. 3).Fig. 3

A flowchart shows the participant population. Subgroups were made on arthroscopic experience at three levels based on the number of arthroscopies performed: novices (0), intermediates (1–59), and experts (> 60). Seven participants evaluated both simulators. The age in years and the number of attended arthroscopies (“Observation”) are expressed as median with range in parentheses. The number of participants who previously had used a simulator (“Simulator”) or had experience in playing computer games (“Games”) is shown.

All participants were scheduled a maximum period of 30 minutes. They had no opportunity to familiarize themselves with either simulator before the experiment. The researcher showed the selection of exercises and performance of the calibration protocol and tasks for the test.
The assessment of construct validity (time to perform a task) was based on one basic navigation task. As the simulators were unlikely to offer a navigation task that was the same, one navigation task was prescribed that can and could be performed on all simulators for comparison. With the arthroscope placed in the anterolateral portal and the probe in the anteromedial portal, nine anatomic landmarks had to be probed sequentially: medial femoral condyle, medial tibial plateau, posterior horn of the medial meniscus, midsection of the medial meniscus, ACL, lateral femoral condyle, lateral tibial plateau, posterior horn of the lateral meniscus, and midsection of the lateral meniscus [32 (link)]. The participants were asked to repeat this navigation task up to five times in a limit of 10 minutes. The navigation task time was defined as described previously [32 (link)] and determined with a separate video recording of the simulator monitor in which the virtual intraarticular joint is presented. We recorded the median time per experience group for each of five repetitions of the navigation task.
Face validity (realism), educational value, and user-friendliness were determined by giving the participants a second task in which exercise(s) had to be performed that were characteristic for that particular simulator and by asking them to fill out a questionnaire afterward. The exercises were selected by the faculty surgeon (GMMJK) and the company to be sure that they best represented the capability of the simulator. Assistance in performing these exercise(s) was given only if a participant failed to continue for a period of 2 minutes. Task performance was pointed out to the participants. The characteristic exercise chosen for Simulator A was “inspection of the suprapatellar pouch with only the 30° arthroscope.” This exercise is set up in three stages: watching an instruction video of the exercise, performing the exercise once guided by example hint-images in a stepwise sequence, and performing the complete exercise once again without guidance. The exercise chosen for Simulator B was threefold: microfracture technique to treat a cartilage lesion in the femoral condyle, visual exploration and probing of a superior labrum anterior superior lesion, and placement of three suture anchors repairing a Bankart lesion (shoulder instability). All three exercises were preceded by textual instructions and had to be performed once. The questionnaire consisted of questions regarding general information (Fig. 3); face validity of the outer appearance of the simulator, the intraarticular virtual joint, and the virtual instruments (Table 1); educational value; and user-friendliness (Table 2). Questions were answered using a 10-point numerical rating scale (NRS) (eg, 0 = completely unrealistic and 10 = completely realistic) or dichotomous requiring a yes/no answer. A 10-point NRS was chosen as all participants were Dutch and this grading system is used at all educational institutions. A value of 7 or greater was considered sufficient. Thus, we expected the grading to be performed based on uniform interpretation of the NRS. Some questions featured a “not applicable (N/A)” answer option, which could be used solely by novices, as these questions required prior knowledge of the real-life arthroscopic situation. For the same reason, only the answers from the expert and intermediate groups were used on simulator realism and educational value. Only answers from the novice and intermediate groups were used on user-friendliness.Table 1

Questions addressing face validity

Face validity aspect	Question
Outer appearance	What is your opinion of the outer appearance of this simulator?
	Is it clear in which joint you will be operating?
	Is it clear which portals are being used?
Intraarticular joint	How realistic is the intraarticular anatomy?
	How realistic is the texture of the structures?
	How realistic is the color of the structures?
	How realistic is the size of the structures?
	How realistic is the size of the intraarticular joint space?
	How realistic is the arthroscopic image?
Instruments	How realistic do the instruments look?
	How realistic is the motion of your instruments?
	How realistic does the tissue feel when you are probing?

All questions were answered on a 10-point numerical rating scale.

Table 2

Questions addressing educational value and user-friendliness

Parameter	Question
Educational value I	The simulator allows training of joint inspection*
	The simulator allows training of therapeutic intervention*
	The simulator allows training of joint irrigation*
	The variation of exercises offered by the simulator is adequate*
	Difference in required skill level between exercises is adequate*
Educational value II	The simulator is a good way to prepare for a real-life arthroscopic operation*
User-friendliness I	How clear are the instructions to start an exercise on the simulator?
	How clear is the presentation of your performance by the simulator?
	Is it clear how you can improve your performance?
	How motivating is the way the results are presented to improve your performance?
User-friendliness II	I felt the need to read a manual before operating the simulator*

* Questions requiring a dichotomous yes/no answer; all other questions were answered on a 10-point numerical rating scale.

The presence of normal distributions of task times was assessed by Kolmogorov-Smirnov tests. Owing to small sample sizes and skewed distributions, the task times were analyzed nonparametrically. Construct validity was determined for each simulator independently by using Kruskal-Wallis tests to calculate the overall presence of differences in task times between the three experience groups for each of the five task repetitions. The significance level was adjusted for multiple comparisons with the Bonferroni-Holm procedure (alpha = 0.05) [11 ]; when we detect significant differences we performed pair-wise comparisons between the experience groups separately using Mann-Whitney U tests. The scores of the three separate aspects of face validity of the simulators (Table 1) and User-friendliness I (Table 2) were expressed as mean summary scores of the corresponding questions. Educational Value I (Table 2) was expressed as a sum score of five dichotomous questions and ranged from 0 to 5. The mean summary scores (Face Validity and User-friendliness I) were verified for normality by Kolmogorov-Smirnov tests, expressed as mean and SD, and assessed for differences between both simulators with Student’s t tests. The ordinal scale of Educational Value I was presented as medians with ranges and analyzed using a Mann-Whitney U test. The dichotomous questions (Educational Value II and User-friendliness II) expressed as categorical yes/no answers were presented as frequencies and percentages (%) and analyzed by chi square tests or Fisher’s exact test (in case one or more cells had expected counts less than five). The significance level was adjusted for multiple comparisons with the Bonferroni-Holm procedure (alpha = 0.05) [11 ].