Abstract
Total Knee Arthroplasty (TKA) necessitates disruption of well vascularised tissue during exposure and soft tissue release as well as from the cutting of bone, and thus bleeding into the joint space routinely occurs to some degree following TKA. Defining a complication from bleeding is not necessarily straightforward, but includes 3 different conditions: hemarthrosis, hematoma, and bloody wound drainage. All of these conditions can be seen in the normal post-operative setting, and when mild may be simply observed. However, persistent swelling resulting in clinical symptoms should be appropriately treated.
A hemarthrosis is defined as blood being contained in the knee capsule. Although some bleeding is expected, “excessive” hemarthrosis results in increased pain limiting or difficulty regaining motion. If high levels of fluid pressure are present, rupture of the arthrotomy may occur. A hematoma occurs when intra-articular blood escapes the arthrotomy and drains into the overlying soft tissues. This may occur following performance of a large lateral release or an insufficient arthrotomy closure or simply secondary to a large hemarthrosis under tension. Symptoms include ecchymosis, soft tissue swelling, and potential skin complications. Increased pain and limited range of motion frequently accompany these symptoms. Wound drainage may present as a knee that continues to have bloody or serous drainage that continues long after the first or second dressing change. It is this continued wound drainage that is most worrisome with increased wound infection rates when prolonged drainage is allowed to persist.
The incidence of post-operative hemarthrosis as a clinical problem is not well studied, but the need for surgical treatment is uncommon. Recurrent hemarthrosis is also relatively rare after total knee arthroplasty and has been reported at rates between 0.3% and 1.6%. The etiology of this complication can be systemic or local, and initial work-up should include coagulation studies to rule out any underling systemic coagulopathy. Conservative therapy including rest, cooling, and elevation is the preferred treatment for mild cases. If conservative treatment is not successful, or the acute hemarthrosis is clinically tense, interfering with recovery, or threatening wound healing, drainage may be the preferable option. This can be done by opening the arthrotomy in the operating room or through a large bore arthroscopy cannulae. Careful attention to debridement of clotted blood must be followed by a meticulous search for potential sources of bleeding which should be managed appropriately.
Recurrent hemarthrosis may occur at any time after surgery. Repeated bleeding episodes may lead to an inflammatory cascade that propagates bleeding events more readily. If coagulation studies are normal, the most common source is the impingement of proliferative synovium or other retained soft tissue between the articulating components of the knee prosthesis. Other causes include damage to the geniculate or popliteal vessels with pseudo aneurysm formation. Mild to moderate clinical knee instability may be associated with bloody synovial effusions but limited clinical complaint specific to instability. Other causes may be multifactorial and synergistic but are not well understood, making diagnosis and treatment more difficult. If symptoms persist, and the resulting disability is sufficient, classical treatment has consisted of open or arthroscopic synovectomy. Over the past decade angiography and angiographic embolization of the source of bleeding has been shown to be successful. Radio-active synovectomy has also been successful.
