Rupture of the knee capsule from articular hyperpressure: Experiments in cadaver knees

Abstract

We used 10 cadaver knees to estimate the safe pressure during arthroscopy by measuring the volumes and pressures of irrigation fluid at different flexion angles. Maximum volumes could be contained at 35 degrees of flexion. Pressures of 200 to 450 mmHg were measured, and all the knees ruptured by extension or flexion after they were filled to 100 mmHg at 35 degrees of flexion. Fifty milliliters of irrigation fluid had to be removed if the pressure remained constant when extending from 35 degrees and 70 ml when flexing to 90 degrees. Totally, 100 ml irrigation fluid had to be removed when flexing from 35 degrees to 120 degrees. Our investigation indicates that a pressure of 150 mmHg can be tolerated by all knees. Both flexion and extension from the 35 degrees position must be done gently and slowly using a large bore, wide-open inflow and outflow tubes allowing egress of irrigation fluid to prevent capsular rupture, extravasation of irrigation fluid, vascular compromise, or compartment syndrome.

Accuracy of pressure and flow capacities of four arthroscopic fluid management systems

“…They concluded that, in order to avoid capsular damage, knee arthroscopy should be done at intra-articular pressure levels below 120 mm Hg. 16 According to Burgaard et al, 5 the intra-articular pressure should be as low as possible and should never exceed 150 mm Hg. In this cadaver study, 10 knees were filled at 35°of flexion to a pressure of 100 mm Hg, were subsequently extended and flexed, and all knees ruptured during this maneuver.…”

“…However, there is evidence in the literature that, with a closed system and even low baseline articular pressures about 20 mm Hg, intra-articular pressures in excess of 200 mm Hg are generated by flexing the knee. 4,5 During routine arthroscopy, rapid movements caused intra-articular pressure values up to 400 mm Hg. 15 To our knowledge there are no reports on experimental flow measurements in the literature.…”

“…3 During arthroscopy in a closed system, pressures in excess of 200 mm Hg can be generated in flexion and extension maneuvers. 4,5 Excessive fluid pressures may result in subcutaneous extravasal diffusion, leading to possible major complications. [4][5][6][7][8][9][10][11][12][13][14] The aim of this study was to test 4 different fluid delivery systems used in routine arthroscopic surgery and to investigate the accuracy of their flow and pressure capacities.…”

Use of an Irrigation Pump System in Arthroscopic Procedures

“…Studies have reported synovial pouch rupture when intra-articular pressure rises in the range of 120 to 150 mm Hg. 21,22 Despite known possible complications related to high pressure, many commercial devices allow pressure values far above 100 mm Hg. 8 Complications rate of 1% have been described in the literature, with complications including fluid extravasation (intraperitoneal and extraperitoneal accumulation), synovial pouch rupture (distension of compartments of the leg and thigh), and compartment syndrome.…”

Tensile properties of the knee-joint capsule at an elevated intraarticular pressure

“…With the pump, however, high inadvertent intraarticular pressures (IAP) might be produced with a risk of tissue damage, capsular rupture and compartment syndrome (Noyes and Spievack 1982, Peek and Haynes 1984, Burgaard et al 1988. Most authors seem to agree that the IAP should be kept as low as possible during arthroscopy, e.g., Ewing et al (1 986) and Bauer and Jackson (1986) recommended an IAP between 70 and 120 mmHg while Bergstrom and Gillquist (1986) suggested that an IAP level of 20-30 mmHg below the systolic blood pressure was ideal for good visualization.…”