|Beitragstitel||Chylous Joint Effusion of the Knee – A case report and literature review|
Introduction- Chylous or milky joint effusions are extremely rare. Here we describe a patient with accelerated ipsilateral anterior knee pain after implanting a total hip prosthesis and chylous effusion in the knee joint.
Case - A 54 y/o female patient suffered knee pain three months after an ipsilateral hip prosthesis was implanted. The patient denied any trauma of the knee, while she detected a painful swelling of the knee directly on the first day after surgery. Initially the swelling was assumed as a postoperativ suffluent hematoma and treated with oral analgetics. A week before the patient was seen in the orthopedic follow up, her knee was punctured by the general practitioner, showing "milky fluid". No fever or shivering. The examination revealed a tender knee with a large effusion, no erythema/warmening. The knee motion was decreased with ext./flex. 0/0/100°. The knee was punctured again in our clinic showing white, milky fluid. The laboratory investigation revealed massive lipids without inflammation or cristalls and we made the diagnosis of a chylarthros. After exclusion of a lymphfistula the patient underwent conservative treatment. Eight months after first symptoms the patient was symptom-free without any deficits. The cause of the chylous effusion couldn't be determined.
Discussion/Conclusion- Increased lipid content of joint fluid, presenting as a macrospically milky fluid is equivalent to a very rare chylous effusion 1,2. These cases are reported with a traumatic joint injury involving the lymphatic system, or in patients, who suffer a systemic lupus erythematosus, RA, filariasis or pancreatitis with fat necrosis5,6,7,8. The largest series was described by Das and Sen4, who screened 25 patients with filariasis who suffered acute knee pain with inflammation but sterile effusion, all self limited. Synovial biopsies in these patients showed inflammatory changes and the lymphangiogram (n=5 patients) showed periarticular lymphangiectasia, varicosities of the popliteal system with a blind channel, ending in the knee joint which suggests a lymphfistula. Diagnostic fluid aspiration and its laboratory investigation (oil staining) is mandatory to make the diagnosis (lipid concentration >800 mg/100 ml (8gl))4. Signs of systemic illness (fever, shivering) or pathological blood results. Elevated WBC, CRP) may be seen, but are usually absent. Additional imaging for detecting insufficiency fractures (MRI, CT) or other bone pathologies are recommended.