A 76-year-old male with a medical history of obesity and arterial hypertension presented with pain in the left wrist with edema, redness, and functional limitation since a week ago. There was no involvement of other joints.
The posteroanterior left wrist radiograph (Fig. 1) shows a widening of the scapholunate interval, known as the Terry-Thomas sign, in honour of the famous British comedian who had a distinctive gap between upper incisors. Additionally, there is osteoarthritis of the radioscaphoid articulation with reduced joint space and markedness subchondral sclerosis contrasting with the absence of osteophytes. These findings are consistent with scapholunate dissociation with scapholunate advanced collapse (SLAC). In addition, linear calcifications can be observed in the triangular fibrocartilage and the scapholunate space, suggesting chondrocalcinosis, which a CT scan performed later also showed (Fig. 2).
The lateral left wrist radiograph (Fig. 3) demonstrates dorsal tilt of the lunate with increased scapholunate and capitolunate angle, consistent with the dorsal intercalated segment instability (DISI).
Given the findings, the diagnostic hypothesis of calcium pyrophosphate deposition disease was raised, confirmed by the presence of calcium pyrophosphate crystals in synovial fluid by polarized light microscopy.
Calcium pyrophosphate deposition disease (CPPD) is a crystalline arthropathy characterized by calcium pyrophosphate crystals in joints and peri-articular structures. It is a common disease associated with various metabolic disorders and mainly affects middle-aged or elderly people [1-4].
The formation of calcium pyrophosphate crystals occurs in the cartilage's pericellular matrix, and their passage to the synovial fluid triggers an inflammatory process responsible for acute disease crises [1-3].
Contrarily, chondrocalcinosis represent any cartilage calcification, often asymptomatic [5].
The CPPD commonly affects the knee, wrist, pubic symphysis, and spine (namely intervertebral discs and odontoid process) [1,3,5]. The involvement is mostly mono/oligoarticular, being polyarticular in only 11% of cases [3].
It is a clinically heterogeneous disease that can manifest as acute arthritis, chronic arthropathy, or asymptomatically, presenting as incidental findings of chondrocalcinosis. Acute arthritis (formerly pseudogout) is usually self-limiting, manifesting with the pain of inflammatory pattern, stiffness, erythema, and oedema [1]. Differently, chronic CPPD arthritis clinically resembles rheumatoid arthritis, with a predominance of radiological features of osteoarthritis [2].
Although identifying calcium pyrophosphate crystals in synovial fluid is necessary, the diagnosis is also supported by characteristic radiological findings [2,4]. Different imaging modalities can be used, but radiography remains the first-line method for diagnosis and monitoring [5]. Typical radiological findings of CPPD include calcifications and arthropathy. Calcifications may involve the hyaline cartilage, fibrocartilages, synovium, bursas, articular capsules, meniscus, tendons, and ligaments. CPPD arthropathy has the same characteristics as osteoarthritis (reduced joint space, subchondral osteosclerosis, and geodes); however, CPPD differs in that: it affects joints usually spared by osteoarthritis, articular surface can be jagged, numerous geodes appear, and there are few or no osteophytes [3,4].
In the wrist, the involvement of the scaphotrapezial joint, lunotriquetral ligament, scapholunate ligament, and triangular fibrocartilage complex is typical. A scapholunate ligament tear results in dorsal intercalated segment instability (DISI) with the lunate rotating into abnormal extension and the scaphoid rotating into abnormal flexion [3,6]. Classic radiographic findings of DISI include increased scapholunate interval (>4mm), increased scapholunate (>60°) and capitolunate (>30°) angles, and the cortical ring sign produced by the shortened distal pole of the scaphoid. With the progression of DISI, there is degeneration and collapse of the carpal known as scapholunate advanced collapse (SLAC). In SLAC advanced stages, the capitate can migrate proximally [6,7].
The treatment of CPPD is symptomatic, but surgery is indicated in cases of carpal instability. Our patient refused surgery, opting for conservative medical treatment with partial improvement.
Written informed patient consent for publication has been obtained.
Scapholunate advanced collapse (SLAC) due to calcium pyrophosphate deposition disease (CPPD)
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Based on the provided X-ray and CT images of the left wrist, the following key features are observed:
Based on the above radiological findings and the patient’s history (76 years old, obese, with hypertension, presenting with one week of left wrist pain, swelling, redness, and limited range of motion affecting a single joint), the differential diagnoses may include:
Considering the patient’s age, clinical presentation (acute or subacute inflammatory joint symptoms, redness, swelling, restricted range of motion), single-joint involvement, prominent chondrocalcinosis in the wrist, and scapholunate ligament disruption leading to wrist instability, the most likely diagnosis is:
Calcium Pyrophosphate Deposition Disease (CPPD) with Wrist Instability and Scapholunate Advanced Collapse (SLAC Wrist)
If further diagnostic confirmation is needed, joint aspiration to detect calcium pyrophosphate (CPP) crystals under a microscope can be performed. In addition, depending on the clinical course and the need to distinguish from gouty arthritis or rheumatoid arthritis, further laboratory tests (e.g., serum uric acid, rheumatoid factor, anti-CCP antibody) may be appropriate.
Rehabilitation and exercise should follow a principle of gradual progression and individualization, especially given the patient’s advanced age, comorbidities (obesity, hypertension), and limited wrist function. Once inflammation subsides or is in an intermittent phase, the following exercise plan may be introduced:
Throughout the rehabilitation process, closely monitor pain, swelling, and range of motion. If significant pain, local heat, or swelling worsens, seek medical evaluation promptly and adjust the program appropriately.
This report is based on the available information for reference only and cannot replace in-person consultation or the opinion of a professional physician. If you have any concerns or if your symptoms worsen, please seek medical attention at a qualified healthcare facility.
Scapholunate advanced collapse (SLAC) due to calcium pyrophosphate deposition disease (CPPD)
