Tophaceous pseudogout of the ankle: case report

An Unusual Case of Huge Tophaceous Pseudogout Mimicking as a Tumor-Like Lesion around the Ankle Joint: A Case Report and Literature Review

Pseudogout or calcium pyrophosphate dihydrate deposition disease (CPPD) primarily affects the joints and the periarticular tissues. Tophaceous or tumoral pseudogout is a rare form of this disease which is seen around the joints of extremities. It can be misdiagnosed as a neoplastic condition because of its clinicoradiological similarities, and thus, a proper histopathological examination is indispensable. We report one such case of extra-articular deposition of the CPPD crystals in a 65-year-old man who presented with an asymptomatic swelling around the left ankle. Radiographs showed a dense homogenous calcification, and FNAC revealed dense calcium deposits with numerous rhomboid-shaped crystals. It was managed by en bloc excision, and postoperative biopsy reports confirmed the diagnosis. Possibility of pseudogout should be kept as a differential diagnosis in patients presenting with calcified soft tissue swellings and should be subjected to a detailed histopathological examination for confirmation.

High-Resolution US of Rheumatologic Diseases

For the past 15 years, high-resolution ultrasonography (US) is being routinely and increasingly used for initial evaluation and treatment follow-up of rheumatologic diseases. This imaging technique is performed by using high-frequency linear transducers and has proved to be a powerful diagnostic tool in evaluation of articular erosions, simple and complex joint and bursal effusions, tendon sheath effusions, and synovitis, with results comparable to those of magnetic resonance imaging, excluding detection of bone marrow edema. Crystal deposition diseases including gouty arthropathy and calcium pyrophosphate deposition disease (CPPD) have characteristic appearances at US, enabling differentiation between these two diseases and from inflammatory arthropathies. Enthesopathy, which frequently accompanies psoriatic and reactive arthritis, also has a characteristic appearance at high-resolution US, distinguishing these two entities from other inflammatory and metabolic arthropathies. The presence of Doppler signal in examined joints, bursae, and tendon sheaths indicates active synovitis. Microbubble echo contrast agents augment detection of tissue vascularity and may act in the future as a drug delivery vehicle. Frequently, joint, tendon sheath, and bursal fluid aspirations and therapeutic injections are performed under US guidance. The authors describe the high-resolution US technique including gray-scale, color or power Doppler, and contrast agent-enhanced US that is used in evaluation of rheumatologic diseases of the wrist and hand and the ankle and foot in their routine clinical practice. This article demonstrates imaging findings of normal joints, rheumatoid arthritis, gouty arthritis, CPPD, psoriatic and reactive arthritis, and osteoarthritis.

Osteochondral distal metatarsal allograft reconstruction: a case series and surgical technique

BACKGROUND

Painful degenerative diseases of the metatarsophalangeal joints (MTPJs) are frequently progressive and difficult to treat. Traditional operative treatments such as debridement, distal metatarsal osteotomies, and arthroplasty present a unique set of complications, and pain and deformity may still occur. Osteochondral distal metatarsal allograft reconstruction (ODMAR) is presented as a salvage procedure, reserved for patients with significant bone loss or avascular necrosis in whom traditional interventions have failed or are inadequate to address the underlying joint deformity.

METHODS

A retrospective review identified all ODMAR cases performed by the senior author over the past 10 years. Patient symptoms, satisfaction, and MTPJ range of motion were measured at each postoperative evaluation. Graft healing and subsequent degenerative changes at the MTPJ were observed at each visit with foot radiographs. The surgical techniques for both first and lesser metatarsal reconstructions are described.

RESULTS

Six patients were identified with average follow-up interval of 36 months (range, 6-66). Preoperative diagnoses included infection (1), fracture (1), and avascular necrosis (4). Mean total arc of motion was 40 degrees (range, 30-50). All patients maintained viability of the allograft metatarsal head and joint space was normal or Kellgren-Lawrence grade 1 in 5 of 6 patients at final follow-up. All patients demonstrated osseous union of the metatarsal osteotomy site. No patients have undergone revision surgery to date.

CONCLUSIONS

ODMAR is a safe and effective procedure for treatment of painful, degenerative conditions of the MTPJs. Further studies are required to determine the definitive indications and long-term outcomes for this procedure.

LEVEL OF EVIDENCE

Level IV, retrospective case series.