Effectiveness of arthroscopic excision based on the distribution of the tenosynovial giant cell tumor around knee joint.

BACKGROUND

The mainstay treatment for tenosynovial giant cell tumor (TGCT) is open excision. However, open excision is associated with the risk of stiffness, infection, neurovascular injury, and prolonged hospital stay and rehabilitation. The purpose of this study was to evaluate the efficacy of arthroscopic excision of tenosynovial giant cell tumor (TGCT) of the knee joint, including the diffuse type of TGCT.

METHODS

Patients who underwent arthroscopic excision of TGCT between April 2014 and November 2020 were retrospectively analyzed. TGCT lesions were divided into 12 distributions (nine intra- and three extra-articular lesions). The distribution of TGCT lesions, portals used, degree of excision, recurrence, and magnetic resonance imaging (MRI) scans were evaluated. The prevalence of intra-articular lesions in diffuse TGCT was also analyzed to validate the existence of a connection between intra- and extra-articular lesions.

RESULTS

Twenty-nine patients were included in the study. Fifteen patients (52%) had localized TGCT, and 14 patients (48%) had diffuse TGCT. The recurrence rates for localized, and diffuse TGCT were 0%, and 7%, respectively. Intra-articular posteromedial (i-PM), intra-articular posterolateral (i-PL), and extra-articular posterolateral (e-PL) lesions were found in all patients with diffuse TGCT. The prevalence rates of i-PM and i-PL lesions among e-PL lesions were both 100% (p = 0.026 and p < 0.001, respectively). Diffuse TGCT lesions were managed with posterolateral capsulotomy and viewed from the trans-septal portal.

CONCLUSIONS

Arthroscopic excision of TGCT was effective in both localized and diffuse TGCT. However, diffuse TGCT was associated with posterior and extra-articular lesions. Therefore, technical modification such as posterior, trans-septal portal, and capsulotomy were required.

STUDY DESIGN

Retrospective case series; level Ⅳ.