Intratendinous tophaceous gout imitating patellar tendonitis in an athletic man

Abstract

Patellar tendon-related pain is common in the athletic patient. When it occurs in skeletally mature patients participating in running, jumping, or kicking sports, the diagnosis of jumper's knee patellar tendonitis is usually made. If patellar tendon pain is associated with a mass, the differential diagnosis should be broadened to include crystalline arthropathy. This article presents a case of a highly athletic 45-year-old man with a history of gout, anterior knee pain, and an enlarging mass in the region of the patellar tendon. Conservative management failed, and an excisional biopsy found it to be an intra-tendinous gouty tophus. To our knowledge, only 1 report exists documenting a patellar tendon mass secondary to gout, and no case report exists documenting this problem in an athlete. The interplay between athletics and gout has not been well described. Despite the long-term protective nature of fitness, transient elevations in uric acid associated with athletic endeavors may contribute acutely to manifestations of gout in some athletes. Resultant intra- or extra-articular pathology may present as, and easily be mistaken for, a sports-related injury. Without appropriate medical management, tophaceous deposition may continue to occur and treatment of the resultant mass may require surgical intervention.

Figure 1

Preoperative AP radiograph showing an enthesophyte near inferior pole of the patella.

Figure 2

Preoperative lateral radiograph showing mild patellofemoral joint osteoarthritis, an enthesophyte near inferior pole of the patella, and a slightly radio-opaque fusiform mass in the midsubstance of the patellar tendon.

Figure 3

Preoperative sunrise radiograph showing mild patellofemoral joint osteoarthritis.

Figure 4

Preoperative T1 sagittal MRI showing mild patellofemoral joint osteoarthritis along with apparent degeneration of the patellar tendon with a 2×2×7-cm heterogeneous intermediate-intensity fusiform mass in the midsubstance of the patellar tendon.

Figure 5

Preoperative T2 sagittal MRI showing mild patellofemoral joint osteoarthritis along with apparent degeneration of the patellar tendon with a 2×2×7-cm heterogeneous intermediate-intensity fusiform mass in the midsubstance of the patellar tendon.

Figure 6

Preoperative T2 axial MRI showing apparent degeneration of the patellar tendon with a 2×2-cm heterogeneous intermediate-intensity mass in the midsubstance of the patellar tendon.

Figure 7

Postoperative T2 sagittal MRI showing mild patellofemoral joint osteoarthritis along with homogenous low-signal thickening of the patellar tendon consistent with scar tissue formation without any evidence of gouty tophus recurrence.

Figure 8

Postoperative T2 axial MRI showing homogenous low-signal thickening of the patellar tendon consistent with scar tissue formation with no evidence of gouty tophus recurrence.