Effects of surgical treatment for acromegaly on knee MRI structural features

Masahiro Nezu, Masataka Kudo, Ryo Morimoto, Yoshikiyo Ono, Kei Omata, Yuta Tezuka, Yasuhiro Igarashi, Shin Hitachi, Kei Takase, Sadayoshi Ito, Fumitoshi Satoh

Acromegalic arthropathy is a common complication of acromegaly and harms the quality of life of the patients even after acromegaly is in long-term remission. A recent study demonstrated by knee MRI the characteristic structural features of acromegalic arthropathy. However, the effects of treatment for acromegaly on such structural features are almost unknown. This study was undertaken to analyze the effects of transsphenoidal surgery (TSS) on acromegalic arthropathy and elucidate whether knee MRI findings are reversible or irreversible. We analyzed 22 patients with acromegaly (63.7% females, median age 58 years) by knee MRI at diagnosis. Out of these 22 patients, 16 who underwent TSS (68.9% female, median age 58 years) were also subjected to knee MRI 2 months after TSS. As for X-ray undetectable findings, MRI detected synovial thickening, bone marrow lesion, ligament injury and meniscus injury in 22.7%, 22.7%, 4.7% and 59.1% of the patients, respectively. With respect to the 16 patients who underwent TSS, clinical and structural improvements were observed respectively in 100%, 66.7% and 66.7% of the patients who showed knee joint pain, synovial thickening and bone marrow lesion before TSS. However, no patient showed structural improvement of meniscus injury after TSS. In acromegalic arthropathy, synovial thickening and bone marrow lesions are reversible while meniscus injury is irreversible. Because all those findings are associated with the exacerbation of arthropathy, they may be therapeutic targets for preventing the progression of arthropathy by endocrinological and orthopedic intervention.