We aimed to determine whether ox muzzle drainage in knee arthroscopy offers a significant benefit in surgical time, irrigation volume, and complications compared to the normal procedure. The results of this study indicate that ox muzzle drainage with double traction does reduce the operative time and increase the amount of irrigation possible, while not changing the rate of operative complications. This is likely due to the improved visualization and better drainage provided by the ox muzzle. To our knowledge, this is the first report about the application of ox muzzle drainage in knee arthroscopy.
Arthroscopy was improved from the cystoscopic method, which was first used by Kenji Takagi for knee joint inspection in 1919. He invented the first 7.3-mm endoscope in 1920 for joint inspection and named it the arthroscope. Later in 1931, it was redesigned at only 3.5 mm, and this instrument would be the prototype for modern optical arthroscopy equipment.[16] Bircher adopted Jacobeus laparoscopy for knee joint examination in 1921 and applied oxygen or nitrogen gas to expand the joint. Yanmis[17] and Kuo[18] reported that application of arthroscopy and an irrigation system in the treatment of purulent knee arthritis obtained a better knee joint function recovery effect than the extensive surgical operation. Thorough irrigation for joint capsule expansion and a guarantee of clear vision are necessary for the operation. Irrigation can remove the bleeding and debris, which is helpful for observing the interior joint cavity more clearly. At present, there are two methods for knee joint cavity irrigation: suspensory gravity irrigation and perfusion pressure pump irrigation. Suspensory gravity irrigation is a classic surgical method with advantages of lower equipment costs and simpler technology. However, the disadvantage is that the perfusion pressure is unstable. Low pressure can cause vision to be blurred by joint cavity hemorrhage, whereas high pressure can cause turbulence, which is bad for vision and increases the degree of edema after the operation. The perfusion pressure pump method offers the advantage of an adjustable pressure, which helps maintain clear vision and reduces the operative time.[5] It can alleviate the degree of edema after operation by reducing the infiltration of liquid. Moreover, it can prevent the phenomenon of water interruption and air entering the joint cavity. However, the related equipment is associated with certain costs. On the other hand, the pressure difference of less than 50 mmHg compared with the systolic pressure can reduce bleeding and improve the clarity of vision, although it also may increase the risk of perfusion fluid extravasation and lead to osteofascial compartment syndrome. Seig thought that the perfusion pump could shorten the operation time compared with suspensory irrigation.[19] Contrarily, Tatari proposed that although use of drains can improve the vision, they are unnecessary for partial meniscectomy, cartilage repair, or limited synovial plica excision operations.[20] In addition, drains cannot keep the pressure stable in the knee joint.[21] Suspensory irrigation cannot provide clear vision, because the drainage may be blocked by the subcutaneous tissue and joint capsule under the lateral edge of the incision. Thus, a drain tube is needed to discharge the irrigation fluid containing blood and debris, which further extends the operation time.[22]
Ox muzzle drainage permits sufficient drainage in multiple conditions such as osteomyelitis. Therefore, we applied ox muzzle drainage in knee arthroscopy by placing the drain through the exterior and interior incision. Ox muzzle drainage was associated with three advantages. First, it holds the subcutaneous tissue under the edge and prevents aggregation of the knee joint capsule cannot, which benefits clear vision. Secondly, the ox muzzle drainage tube can effectively pull open the fat pad to improve the surgical view, instead of cleaning the fat pad, thus shortening the operation time. Thirdly, the surgical instruments can be placed within the joint cavity to place the tube easily, avoiding unnecessary side injury to structures such as the articular cartilage, meniscus, and cruciate ligament.[23–26] Lastly, it may avoid osteofascial compartment syndrome caused by fluid infiltration to the crural fascia upon osmotic pressure.[25] Therefore, ox muzzle drainage is theoretically an ideal choice for knee arthroscopy.
We attempted to provide a better overall rating of the visualization by having the surgeon score the quality of the visibility (NRS) every 5 to 10 minutes. In accordance with the method used by Tuijthof et al. the visual clarity is measured and expressed as a percentage of “good visibility” (NRS > 7). We found a 21% improved visual clarity in the ox muzzle drainage group .Turbidity is the most common source of disturbance in knee arthroscopy and is present during a considerable percentage of the operation time. Our results show that for routinely performed arthroscopic knee operations, the ox muzzle drainage system resulted in a significantly reduced presence of turbidity. This finding can be explained by the continuous flow that spanned a wider area due to the traction of the drainage tube, as opposed to the flow caused by leakage along the portals. Meanwhile, the larger amount of irrigation used in ox muzzle drainage group further supports this conclusion. In addition, the shorter operation time in the ox muzzle drainage group also prompted faster and easier insertion and removal of the surgical instruments. No difference was observed in the numbers of complications in the two groups, suggesting that ox muzzle drainage led to no more complications than the traditional method.
Our study had some limitations. Our series was not large, because this is a new attempt in knee arthroscopy. Moreover, our follow-up time was short, which means some complications may not have been detected. Thus, a study with a larger population and longer follow-up is needed to better evaluate the effectiveness and convenience of ox muzzle drainage in knee arthroscopy. Furthermore, many experienced surgeons can still create a clear surgical view and shorten the operation time effectively without ox muzzle drainage. Therefore, in our opinion, ox muzzle drainage is most helpful for beginner surgeons performing knee arthroscopy.