Dupuytren is a change in normal structures 6099177, transforming the superficial palmar fascia into cords, and joins fascia to the undersurface of the skin to form nodules 7071229. Although resembling a tumor in some ways 6197420, it is not. The longitudinal (lengthwise) fibers of the superficial palmar fascia are clinically affected 3068887, but transverse (sideways) fibers also show chromosomal evidence of involvement 3414684. Although only certain regions of the fascia appear affected, the biochemistry of the entire fascia is abnormal 6197420. The ring finger is most commonly affected, then the small finger, and then the thumb (28%) 12531665. Thumb involvement can take many forms 3958553, 7049485, and usually occurs when other fingers are affected 10050250. Rarely, the wrist may be involved 11901473, 9119844 , 8771479. “Knuckle pads” 3190317,2943155 on the dorsal PIP joints are apparently the same process as nodules in the palm. Although neither produce contractures 6707508, knuckle pads are associated with more aggressive forms of the disease 1960491. Isolated cords in the fingers may develop between the proximal phalanx periosteum (bone lining at the base of the finger) and the flexor tendon sheath at the middle phalanx level 3968392. Abductor pollicis muscle and tendon involvement may affect small finger contractures 6512361.
Normally, the skin is anchored down to the underlying fascia by many tiny tissue strands running perpendicular down to the fascia. When the fascia shrinks, these threads pull the skin, and may result in nodules, dimples, or both contour changes:
Secondary changes may also occur. The position of the finger nerves may be shifted by the growth of a “spiral cord”, especially when the PIP joints become contracted 7822934, 1769988. Extensor tendons on the back of the finger may be indirectly affected4015238: the central slip tendon which straightens the PIP joint may become stretched out from the joint being bent for a long time 7806815, and the transverse retinacular ligaments on the sides of the joint may become fibrotic, resulting in a boutonniere deformity 3249131, 3190317.
Rarely, the extensor tendons may be affected by PIP knuckle pads 6693470 or distal to the PIP joint 7119399. Other changes in the PIP joint may prevent full correction of contracture 4078465 using surgical techniques which work for non-Dupuytren’s PIP contractures 1779164. Bone spurs may develop in the finger bones as a result of tension on the attachments to bones11982519, 10433443. Rarely, the DIP joints are involved 1773223.
Outside the hand, the sole of the foot (Ledderhose’s disease) and the penis (Peyronie’s Disease) may be affected in a similar fashion. The combination of all three conditions – Dupuytren’s diathesis, Ledderhose’s contracture and Peyronie’s disease – is referred to as Dupuytren’s diathesis 8817754 and is associated with a particularly aggressive condition.