Primary lipoma arborescens of the knee may involve the development of early osteoarthritis if prompt synovectomy is not performed

Abstract

BackgroundPrimary lipoma arborescens (LA) is a rare, benign intra-articular hyperplastic tumor that has been associated with osteoarthritis (OA). The aim of this study was to determine whether prompt synovectomy could avoid progressive joint degeneration in cases of primary LA of the knee.Materials and methodsA review of currently available literature about the disease was carried out. The clinical, histological and radiological records of a series of nine knees with primary LA diagnosed and treated between 2002 and 2012 were retrospectively reviewed. Eight of the knees had histological confirmation of LA and none had evidence of condropathy on the initial magnetic resonance image or degenerative changes at the initial radiographic examination.ResultsAt the final follow-up no evidence of OA was found in the three knees that underwent synovectomy when symptoms did not last more than 1 year. The five knees in which synovectomy was delayed developed progressive joint degeneration.ConclusionIn this series, primary LA of the knee involved the development of early osteoarthritis when prompt synovectomy was not performed. Timely synovectomy is strongly recommended, if not mandatory.Level of evidenceIV.

Spectrum of Fat-containing Soft-Tissue Masses at MR Imaging: The Common, the Uncommon, the Characteristic, and the Sometimes Confusing

“…It is characterized by mature fatty infiltration of connective tissue underneath the synovial lining (15,16). It usually manifests in adults with gradual painless joint swelling (17). It is most common in the knee, involving the suprapatellar recess.…”

“…Radiographs may show increased soft-tissue opacity in the suprapatellar recess, a nonspecific finding. Advanced cases may show findings of subchondral erosions, subchondral cysts, or secondary osteoarthritis (17). At MR imaging, findings of intra-articular frondlike fat-containing masses with associated joint effusion are pathognomonic for lipoma arborescens (Fig 4) (15).…”

“…At MR imaging, findings of intra-articular frondlike fat-containing masses with associated joint effusion are pathognomonic for lipoma arborescens (Fig 4) (15). It is usually treated with arthroscopic or open synovectomy (17).…”

Primary lipoma arborescens of the knee

“…This case increases attention to this rare condition, whereas the primary occurrence of the lesion has already been described in the literature (7). We are reiterating the relevance of MRI for this diagnosis and the fact that general practitioners need to keep this suspicion in mind when dealing with recurring effusion and increased joint volume through synovial proliferation.…”

Synovial Fat Deposition of the Knee Is Associated with Degenerative Joint Disorder

“…On the other hand, some investigators speculated that lipoma arborescens may contribute to the development of osteoarthritis (Hallel et al 1988;Ryu et al 1996). One retrospective review suggested that primary lipoma arborescens of the knee may induce development of early osteoarthritis if prompt synovectomy was not performed (Natera et al 2015). Although the severity of osteoarthritis seemed to be correlated with disease duration, aspects of the accompanying degenerative processes remained unclear with regard to cause and effect relationships.…”