Measurement of Intra-articular Pressures during Stifle Arthroscopy Using a Cadaver Model

Introduction: Commercial fluid pump pressure (FPP) systems in humans have shown significant differences between target and delivered IAP (intra-articular pressure), with FPP settings of 50 mmHg producing IAP measurements of up to 160 mmHg. The aim of the study was to measure canine stifle IAP during arthroscopy using three FPP settings to determine if values used in veterinary medicine exceed IAP (170 mmHg) known to cause permanent plastic deformation of the joint capsule.

Materials and Methods: Frozen thawed canine cadavers were used. The stifle was distended using a 2.7-mm arthroscope connected to a fluid pump. IAP was measured using a portable pressure gauge connected to an 18G needle. IAP was recorded during stifle extension, 90° flexion, and full flexion at three FPP settings (30, 50, 80 mmHg).

Results: A total of 27 stifles met the inclusion criteria. IAP significantly increased at higher FPP (p < 0.01). At FPP 30, 50, and 80 mmHg, the mean IAP was 51.8, 103.3, and 175.2 mmHg respectively. At FPP 30 and 50 mmHg, IAP always remained under 170 mmHg. At 80 mmHg, IAP raised to or above 170 mmHg in 11/14 stifles. Stifle position significantly affected IAP, with extension decreasing IAP by 22.4 mmHg, flexion increasing IAP by 20.9 mmHg (p < 0.01).

Discussion/Conclusion: Caution should be used during stifle arthroscopy to limit risk for iatrogenic capsular damage. FPP 30 mmHg is considered safe when using a 2.7-mm arthroscope and high flow cannula. If higher FPP is necessary for visualization, duration of stifle flexion should be limited. The use of FPP 80 mmHg should be avoided.

Acknowledgments: G. Kordas (CISER) for advice on statistical analysis. CVM Intramural Grant for purchase of consumables.

Publikationsverlauf

Artikel online veröffentlicht:
11. September 2023