Surgical Treatment of Intra-articular Knee Venous Malformations: When and How?

BACKGROUND: To assess the efficacy of surgical treatment of intra-articular knee venous malformations (VM).

METHODS: Between 1998 and 2010, 8 children (mean age: 12.3 y) underwent surgical resection of their vascular malformation (7 venous and 1 capillary venous) involving the knee joint. The lesion was diffuse in 6 cases and well-demarcated in 2 cases. All children were suffering from knee pain and had recurrent hemarthroses. Color-Doppler ultrasonography, magnetic resonance imaging, computed tomography scan, and blood test were performed preoperatively. Preoperative and postoperative physical examination, clinical symptoms, and orthopaedic evaluation were retrospectively reviewed. Surgery consisted in arthrotomy with total excision of the vascular malformation for the 2 well-demarcated lesions and synovectomy with squeezing of the surrounding vascular malformation for 5 diffuse lesions. One patient with an extensive venous malformation associated with severe localized intravascular coagulopathy and mild hemophilia A had undergone synovectomy by knee arthroscopy.

RESULTS: Immediate postoperative follow-up was uneventful in 6 patients, whereas 2 patients with diffuse vascular malformation and coagulopathy suffered from postoperative hemarthroses, delaying their rehabilitation. After a mean follow-up of 5.1 years, persistence of the VM within the joint was observed in the 6 initially diffuse lesions. The 2 well-demarcated lesions showed no evidence of disease at latest follow-up. Four patients with preoperative chondropathy and functional impairment were not substantially improved regarding their range of knee motion at latest follow-up, whereas the 4 others were free of symptoms. Only 1 patient presented a recurrent hemarthroses after a 5-year-symptom-free period and had to be reoperated. Patients without preoperative chondropathy recovered normal knee function mobility.

CONCLUSIONS: This retrospective study highlights the importance of early surgery in patients with intra-articular venous malformation, even if asymptomatic, to prevent joint impairment. For well-demarcated lesions, total resection by arthrotomy can provide definitive healing without resuming of symptoms. Although diffuse lesions treated by synovectomy still persist in the joint, treatment avoids recurrence of hemarthroses and, therefore, protects the cartilage from further erosion.

LEVEL OF EVIDENCE: Level IV-cases series.