A new wide-angle arthroscopic system: a comparative study with a conventional 30° arthroscopic system.

Purpose: To compare users' hand movements in performing validated shoulder arthroscopic tasks between a 30° and a wide-angle arthroscopic system, using phantom models with an optical motion analysis system.

Methods: Twelve orthopaedic residents were enrolled and randomly allocated into two groups. In order to compensate for any learning effect, a Latin square counterbalancing technique was used. An optical motion analysis system was used with markers affixed to pre-designed sites; each participant conducted four validated shoulder arthroscopic tasks using both arthroscopic systems. Each participant was instructed to perform the experiment three times with each arthroscope. The time taken, total path length, number of movements, and average acceleration were analysed.

Results: Significant differences were observed for the time taken, number of movements, and average acceleration between the two arthroscopic systems (P < 0.05 for all). However, the time taken was not significant. The mean total path length measured 53 ± 38 cm with the 30° arthroscope, while the mean with the wide-angle arthroscope was significantly shorter, at 36 ± 22 cm. The mean number of movements with the 30° and wide-angle arthroscopes were 1974 ± 1305 and 1233 ± 990, respectively, while the average accelerations were 2.6 ± 1.3 and 1.2 ± 0.6 cm/s(2), respectively. The mean time taken was 13 % faster when using the wide-angle arthroscopic system, although this was not statistically significant.

Conclusion: The wide-angle arthroscopic system improved the arthroscope manoeuvre in terms of the total path length, number of movements, and average acceleration required for experimental arthroscopy. This system may help surgeons triangulate the arthroscope and surgical instruments during surgery by expanding the field of view.