Hand Surgery Source

Symphalangism

Test, Exam and Signs

Historical Overview

  • In 1916, Harvey Cushing first described symphalangism, or ankylosis of the interphalangeal (IP) joints of the fingers.1,2

Description

  • Symphalangism is diagnosed primarily through observation. Symphalangism involves a stiffness of either the proximal interphalangeal (PIP) or the distal interphalangeal (DIP) joints of the fingers, with PIP joint involvement being more common. Fused phalanges of the ring and little finger are the most common.3,4
  • There are three grades of symphalangism: fibrous, cartilaginous and bony.2

Pathophysiology

  • Symphalangism may arise from a spectrum of syndromes, including Apert’s, Poland’s and multiple synostoses.4

Instructions

  1. Obtain an accurate and complete patient history. Ask if the patient experiences any difficulties with fine manual dexterity in the affected fingers. These difficulties may affect activities such as writing and playing musical instruments.
  2. Examine the affected fingers for stiffness and difficulty making a fist.
  3. Check for absence of volar skin creases at the affected joint(s).
  4. Examine the contralateral hand; symphalangism can be bilateral.

Variations

  • Determine whether the symphalangism is fibrous, cartilaginous, or bony at the time of the exam. According to the patient’s age at diagnosis, the same joint can be classified as either fibrous, cartilaginous, or bony.2

Related Signs and Tests

  • Range of motion (ROM), active
  • Range of motion (ROM), passive
  • Grip strength
  • Joint exam
  • Skin test
  • Radiographs
  • Magnetic resonance imaging (MRI), without contrast

Diagnostic Performance Characteristics

  • Beginning in late childhood, radiographic evidence may be used to improve reliability.3
Definition of Positive Result
  • A positive result occurs when the affected PIP or DIP joints show stiffness and the patient experiences difficulty making a complete fist.
Definition of Negative Result
  • A negative result occurs when the affected PIP or DIP joints do not show stiffness and the patient does not experience difficulty making a fist.
Comments and Pearls
  • Non-operative treatment for symphalangism includes physical and occupational therapy. 
  • Operative treatment should be pursued only if conservative treatments have been unsuccessful. 
  • Use arthroplasties, such as IP joint arthroplasty, angular osteotomy and capsulotomy, to try to correct the fusion of joints. Postoperative physical therapy may be needed.2,5
Diagnoses Associated with Tests, Exams and Signs
References
  1. Cushing H. Hereditary anchylosis of the proximal phalangeal joints (Symphalangism). Proc Natl Acad SciUSA 1915;1(12):621-2. PMID: 16576087
  2. Baek GH, Lee HJ. Classification of symphalangism in interphalangeal joints of the hand. Clin Orthop Surg2012;4(1):58-65. PMCID: 3288495
  3. Letts M, Davidson D, Beaulé P. Symphalangism in children. Case report and review of the literature. Clin Orthop Relat Res1999;366:178-85. PMID: 10627733
  4. Leonidou A, Irving M, Holden S, et al. Recurrent missense mutation of GDF5 (p.R438L) causes proximal symphalangism in a British family. World J Orthop2016;7(12):839-42.PMID: 28032038
  5. Baek GH, Kim J, Park JW. Mobilization of joints of the hand with symphalangism. Hand Clin2017;33(3):551-60. PMID: 28673631