Michelangelo's letter at age 80 described an acute attack of foot pain; this, he was told, was caused by gout. A physician may have made this diagnosis, since he had been under medical care for kidney stones for many years. No other gouty attacks were documented, but Michelangelo had a high tolerance for discomfort, and it is possible that earlier, milder episodes might not have been mentioned. Is it possible that he had tophi on his knee 4 or 5 decades earlier when David and Raphael's fresco were created? Occasionally, tophi may be the presenting feature of gout,[13,14] more commonly seen in older women with renal failure.
Clearly, Michelangelo's urinary problems, starting at age 50, with recurrent episodes of nephrolithiasis during the remaining years of his life, were a more significant cause of disability than his gout. The composition of these stones is unknown, but these could have been uric acid or calcium stones seen commonly in gout patients. Renal failure may have contributed to his terminal illness. Even so, Michelangelo was working a full day just weeks before his death.
His lifestyle did not conform to the usual gouty stereotype. His diet contained little meat and his alcohol intake was not excessive. He was lean and physically active. No information regarding a family history of gout is available. The possibility of lead poisoning as a risk factor for gout has been raised, since he used lead-based paint and drank wine, which may have had high lead concentrations.[11,12] Lead-related or "Saturnine" gout affects the knee more frequently than does primary gout, but nephrolithiasis is uncommon because uric acid excretion is low. This cannot be ruled out, but the hypertension and progressive renal failure associated with saturnine gout would be difficult to reconcile with Michelangelo's 89-year life span, which was certainly unusual for that era.[15–18]
Another possible explanation for an early appearance of tophi is overproduction of uric acid caused by a deficiency of the enzyme hypoxanthine-guanine phosphoribosyl transferase (Lesch-Nyhan disease). In its classical form, this condition features self-injurious behavior, cognitive impairment, and various motor dysfunctions, but there are attenuated variants wherein these are mild or rarely even absent. However, it would seem unlikely that Michelangelo's extraordinary body of work could have been produced in the face of any level of motor or cognitive dysfunction.
In his later years, chronic disease, including some rheumatic conditions, was a source of disability. In 1557, he complained that he was unable to walk upstairs because of backache and later complained to a friend of impairment in using his hands. The latter could have been related to osteoarthritis, or less likely to chronic tophaceous gout, or some other rheumatic or neurologic disorder. Nevertheless, Michelangelo persevered to the end, despite his depression and physical problems. Even if Michelangelo had undocumented gout attacks before the first report at age 80, is it possible that tophi were present when he created David (age 26) and when his image was said to have been painted by Raphael (age 36). The probability would seem to be low. Was there another cause for his "knobby" knee? Traumatic arthritis might be considered because he had several falls from scaffolds during his career. It is not likely that these questions will ever be answered.
Another speculative explanation for the knee nodularities is that they served as a marker for Michelangelo's long association with the Medici family. The Medici commissioned several works by Michelangelo during his long career, including 2 sculptures in the Medici tombs. Unfortunately, Lorenzo was buried elsewhere in an unmarked grave. He was taken into the Medici household by Lorenzo ("The Magnificent") de Medici at age 15 and remained there for approximately 4 years. Lorenzo sent for him frequently during the day, and Michelangelo often sat next to him at meals and at times at his private chambers, where a knee might have been exposed.[4,5,20] The boy viewed his patron with awe and reverence. Lorenzo had severe, deforming polyarticular arthritis considered to be gout, as did his father, grandfather, and great grandfather, all of whom became crippled and disabled from their gout in their later years. However, recent paleopathologic studies in the Medici tombs of skeletal remains of individuals believed to have gout yielded surprising results. Only 1 of 4 skeletons examined had typical lesions of gout in a foot. Erosions more typical of rheumatoid arthritis (RA) were found in 3 other Medicis, one of whom had the HLA DR4 genotype associated with RA. Clearly, during the Renaissance, the term gout included other inflammatory rheumatic diseases, which would be described in future years.
Several later works by Michelangelo, including sculptures, drawings, and paintings, also show male figures with a suggestion of nodularity over the anterior knee, more prominent on the right. These include The Creation of Adam (painting), Garden of Antiquities of Jacob Galli, Rome (drawing), The Dream of Human Life (drawing), and The Tomb of Giuliano de Medici (sculpture; Fig. 2). Could these images represent a special mark or signature relating to Michelangelo's own knee or to a Medici knee? Alternatively, the knobby knees may have been a stylistic mannerism, shared with other artists. Raphael, for example, painted knobby knees on several subjects who were unlikely to have had gout. Thus, there is insufficient evidence to support our impression that Michelangelo may have had early-onset tophaceous gout. When an 80-year-old Michelangelo describes briefly in one of his letters an episode of acute, severe foot pain, with no mention of trauma, acute gout has to be ranked as one of the top diagnoses in our differential diagnosis list. However, gout seems to have had little impact on his artistic productivity.
J Clin Rheumatol. 2015;21(7):364-367. © 2015 Lippincott Williams & Wilkins