Infection of tophaceous nodule

Case contribution: Dr Radhiana Hassan

Clinical:

  • A 72 years old man
  • Underlying DM on insulin injection, HPT, dyslipidaemia and gouty arthritis
  • Presented with pus discharge at right foot for 3 days
  • It is associated with pain and fever
  • Clinically right foot is dry with podagra measuring about 5×4 cm. There is surrounding cellulitis and 2 ulcers with pus discharge
  • DPA and PTA arteries are palpable. Full range of motion of the ankle
Radiograph of right foot in PA and oblique views

Radiographic findings:

  • A large soft tissue swelling adjacent to the first metatarsophalangeal joint
  • It is eccenterically located with air pocket within (yellow arrow)
  • Subarticular bone erosion seen of the head of adjacent metatarsal (white arrow)
  • No fracture or dislocation

Intra-operative finding

  • Wound debridement done under GA
  • Wound over the gouty tophi debridement and extended dorsally and plantarly until healty soft tissue seen
  • Pus discharge around the gouty tophi and extending into the 1st metatarsal bone
  • Head of metatarsal bone is fairly good condition with bleeder seen after removal of chalky necrotic tissue overlying it
Foot radiograph in PA and oblique views 3 months after the operation

Diagnosis: Infected tophus

Discussion:

  • Tophus/tophi usually appear as lumps on the skin over affected joints in patients with longstanding high levels of serum uric acid
  • It is due to deposits of monosodium urate crystals
  • Tophi are a pathognomonic feature of gout.
  • On radiograph, tophi are typically seen as eccentric, juxta-articular soft tissue nodules.
  • Bony erosions with sclerotic margins and overhanging edges are commonly seen in their proximity
  • Tophi are not be surgically removed unless they are in a critical location or drain chronically.
  • Surgery is indicated for tophaceous complications, including infection, joint deformity, compression and intractable pain, as well as for ulcers related to tophaceous erosions.
  • Delayed healing is noted in 50% of patients.
Author: radhianahassan