According to the reports of a recently published analysis in a journal of the International Union of Biochemistry and Molecular Biology, BioFactors, ghrelin, a 28-amino-acid polypeptide shows protective role against inflammation and cartilage lesions and its lower expressions in synovial fluid (SF) associated with the progression of ankle PTOA.

A total of ninety-seven patients who went through an arthroscopic examination and obtained debridement or replacement of the ankle joint and ninety-five healthy participants who received periodic body checkups were selected. The levels of ghrelin in SF and serum were evaluated using enzyme-linked immunosorbent assay (ELISA). SF was also investigated for cartilage degradation enzyme; tumour necrosis factor-alpha (TNF-α) and matrix metalloproteinases-3 (MMP-3). Further, radiographic severity was assessed using the modified Kellgren-Lawrence (K-L) grading system, and clinical evaluation by visual analogue scale (VAS) & the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot rating scale. The histopathological changes occur due to cartilage lesions were measured by modified Mankin's score.  In comparison to MMP-3 and TNF-α, the diagnostic significance of the ghrelin levels in the prediction of the radiographic grading was measured by assessing the area under the curve of the receiver operating characteristic (ROC) curve.

No notable alterations were seen between healthy and ankle PTOA participants regarding serum abundance of ghrelin. Radiographic progression showed a negative association with SF ghrelin. The VAS scores also negatively associated with  SF ghrelin, whereas the AOFAS ankle-hindfoot rating showed a positive association. The expressions of MMP-3/TNF-α and disease progression was inversely associated with SF ghrelin concentrations. As per ROC analysis curve, ghrelin emerges as a promising marker to diagnose radiographic severity. Local implementation of ghrelin may act as a satisfactory adjuvant therapy to slow the progress of ankle PTOA.