A 20-yr-old man was referred to our outpatient clinic with painless limitation of his finger joints. These symptoms had been present since birth and he had difficulty with activities requiring manual dexterity. His mother, sister, and brother were affected similarly. No other comorbid condition was present. Bilateral movement of the third to fifth proximal interphalangeal joints was absent; they were fixed in extension. The knuckles were smooth over the proximal interphalangeal joints of these fingers (Fig. 1A), and the distal phalanx motions were normal (Fig. 1B). No arthritis or nail lesion was found, and the remainder of the patient’s locomotor system was normal. Plain radiographs showed ankylosis in the limited joints (Fig. 1C). The fourth and fifth toes of both feet appeared to have single interphalangeal joints (Fig. 1D). The non-ankylosed joints appeared normal, and no erosion or degenerative change was observed. Serologic markers and biochemical assays were normal. Because the patient had minimal difficulties with activities of daily living, he refused surgical intervention. We arranged an exercise program to improve the functional use of his hands.
Symphalangism is a rare condition characterized by ankylosis of the interphalangeal joints. This autosomal dominant disorder was first described by Harvey Cushing in 1916.1 Recent molecular studies have revealed that the causative abnormal genes are localized on chromosome 17q22. Ankylosis can involve the proximal interphalangeal or distal interphalangeal joints, although proximal interphalangeal joint involvement is more common.2 The fused phalanges can cause disability or loss of hand function, including the inability to make a fist or perform activities that require fine manual dexterity. Symphalangism may be associated with Nievergelt-Pearlman, Poland, Apert, Herrmann, and multiple synostoses syndromes.2,3
The treatment of symphalangism has been uniformly unsuccessful. Manipulations and various arthroplasties can be applied to the fusions, but patient satisfaction is poor.4 Surgical intervention is rarely indicated, and physical, occupational, and exercise therapies are usually beneficial.3 We recommend that clinicians emphasize physical therapy before considering surgical intervention.
1. Cushing H: Hereditary anchylosis of proximal phalangeal joints (symphalangism). Genetics
1919; 1: 90–106
2. Borah D, Wadhwa S, Gupta AK, et al.: Symphalangism in an Indian family. Ind J Phys Med Rehabil
2006; 17: 18–20
3. Joshi A, Nagaraj C, Saurabh S, et al.: Symphalangism-role of physical therapy. Eur J Radiol Extra
2008; 65: 101–3
4. Flatt AE, Wood VE: Rigid digits or symphalangism. Hand
1975; 7: 197–214