Calcium pyrophosphate dihydrate crystal deposition patterns in the triangular fibrocartilage complex

Chondrocalcinosis of the Wrist

Calcium pyrophosphate dihydrate deposition (CPDD) disease has characteristic radiographic features including soft tissue calcification, joint space narrowing, bone sclerosis, subchondral cyst formation without osteophyte formation, and large intraosseous geodes. Triangular fibrocartilage calcification is frequently found and isolated scapho-trapezio-trapezoid (STT) arthritis is specific for CPDD. Distal radio-ulnar (DRUJ), isolated midcarpal joint and piso-triquetral joint involvement also occur. 127 patients were reviewed. Seventy-eight had symptomatic STT joint arthritis, for which 36 underwent surgery. Twenty-two patients had a SLAC wrist deformity for which ten underwent surgery. Eight patients had isolated midcarpal arthritis for which three midcarpal arthrodeses, two four-bone arthrodeses and two carpal tunnel releases were performed. Nineteen patients had a generalized arthritis and seven of the patients underwent surgery: fourcorner arthrodesis+scaphoidectomy (one case), carpal tunnel relaease (two cases) extensor synovectomy (two cases) and trigger finger release (two cases).

Extensor tendon rupture associated with osteoarthritis of the distal radioulnar joint

Non-rheumatoid osteoarthritis of the distal radioulnar joint can cause extensor tendon rupture. We analysed the radiographic morphology of the distal radioulnar joint to identify the risk factors for this complication. Forty-one wrist X-rays of 37 patients with extensor tendon rupture caused by distal radioulnar joint osteoarthritis were evaluated retrospectively for the severity of osteoarthritis by the Kellgren/Lawrence scoring system. Measurements were obtained from posteroanterior views. All but one wrist had severe osteoarthritic changes exceeding grade 3. The radiographic features that were different from those of the contralateral wrists included deepening and widening of the sigmoid notch, radial shift of the ulnar head and dorsal inclination of the sigmoid notch. There was no significant association between tendon rupture and the morphology of the ulnar head or ulnar variance. The scallop sign, dorsal inclination of the sigmoid notch and radial shift of the ulnar head are radiological risk factors for extensor tendon ruptures.

Carpal osteoarthrosis

Despite improved understanding of carpal mechanics, increased awareness of intercarpal ligament injuries, and improved techniques for treating carpal instability, post-traumatic intercarpal osteoarthrosis remains a common problem. Osteoarthritis of the carpal bones, including scapholunate advance collapse wrist, scaphotrapeziotrapezoid arthritis, lunotriquetral arthritis, triquetrohamate arthritis, and pisotriquetral arthritis, follows specific unique patterns, but in each, the final common pathway leads to degenerative change. Injury or deformity leads to instability and altered kinematics, producing abnormal joint contact pressures. Cartilage injury and eventual degeneration of the join follow. The etiology, prevalence, and current evaluation and treatment of these conditions are of importance to hand surgeons.

Biology of Fibrocartilage Cells

Fibrocartilage is an avascular tissue that is best documented in menisci, intervertebral discs, tendons, ligaments, and the temporomandibular joint. Several of these sites are of particular interest to those in the emerging field of tissue engineering. Fibrocartilage cells frequently resemble chondrocytes in having prominent rough endoplasmic reticulum, many glycogen granules, and lipid droplets, and intermediate filaments together with and actin stress fibers that help to determine cell organization in the intervertebral disc. Fibrocartilage cells can synthesize a variety of matrix molecules including collagens, proteoglycans, and noncollagenous proteins. All the fibrillar collagens (types I, II, III, V, and XI) have been reported, together with FACIT (types IX and XII) and network-forming collagens (types VI and X). The proteoglycans include large, aggregating types (aggrecan and versican) and small, leucine-rich types (decorin, biglycan, lumican, and fibromodulin). Less attention has been paid to noncollagenous proteins, although tenascin-C expression may be modulated by mechanical strain. As in hyaline cartilage, matrix metalloproteinases are important in matrix turnover and fibrocartilage cells are capable of apoptosis.

Arthrose non traumatique du poignet : la chondrocalcinose

Post-traumatic arthritis of the wrist is a common disorder, mostly after scapho lunate or scaphoid injury. Some patients in our experience and in literature have no known trauma, are bilateral and have a mean age much higher than usual post-traumatic cases. Radiological (during an often-extensive medical history) and biological studies of these patients led us to think there is a form of chondrocalcinosis of the wrist, with a four stages evolution, similar to SLAC and SNAC wrist but with often no scapho lunate gap, vertical embedding of the scaphoid in the radius and chalky incrustation of the joint. We called that form of dislocation of the carpus: scaphoid chondrocalcinosis advanced collapse or SCAC wrist. Surgical treatment of advanced cases is described. Scaphoidectomy and resection of triquetrum are performed, associated with hamato-luno-capitate fusion. Other rare forms are described and literature (mostly radiological and rheumatological because these patients are often been mistaken as SLAC wrist) is studied.

Radiographic tools for assessment of pathologic cartilage calcification

Both hyaline cartilage and fibrocartilage can calcify in a variety of pathologic conditions. Traditionally, plain film radiographs have been used to diagnose such calcifications; however, only when the calcifications have adequately mineralized are they radiographically apparent. Cross-sectional imaging modalities such as computed tomography, magnetic resonance imaging, and ultrasonography can often demonstrate cartilage calcifications before they are radiographically apparent, thus yielding earlier detection of disease processes. Cartilage calcifications have a distinct appearance on each of these various imaging modalities. A working knowledge of the typical locations of cartilage calcific deposits as well as their appearance on various imaging modalities is necessary for accurate diagnosis.

Scapholunate advanced collapse pattern of arthritis in calcium pyrophosphate deposition disease of the wrist

Chondrocalcinosis is a well-described radiographic finding in patients with calcium pyrophosphate dihydrate deposition disease of the wrist and other joints. The medical records and x-ray films of 12 patients evaluated over an 18-month period for chondrocalcinosis of the wrist were examined for symptoms and physical and x-ray film findings. Thirteen wrists were affected. All wrists were noted to have calcification of the triangular fibrocartilage complex. Twelve of 13 wrists had the characteristic features of the scapholunate advanced collapse pattern of arthritis. In addition, there was a correlation in our series between chondrocalcinosis and carpal tunnel syndrome. Destruction of the interosseous soft tissues caused by crystalline deposition could alter the biomechanics of the wrist in a similar fashion to that of the post-traumatic scapholunate advanced collapse wrist leading to arthritic symptoms.