• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
bone and spine logo

Bone and Spine

Your Trusted Resource for Orthopedic Health Information

  • Home
  • About
  • Contact Us
  • Policies
  • Show Search
Hide Search
You are here: Home / Pediatric ortho / Symphalangism – Causes, Classification and Treatment

Symphalangism – Causes, Classification and Treatment

Dr Arun Pal Singh ·

Last Updated on October 10, 2020

Symphalangism is a condition where there is congenital ankylosis [fusion] of the interphalangeal joints  of the phalanges of the hand or foot.

The condition may involve metacarpophalangeal joints as well.

The condition occurs because of the failure of the interphalangeal joint to differentiate during the development.

Symphalangism leads to the functional impairment and unsightliness of the affected finger. Ulnar digits are more commonly involved.

The condition was first described by Harvey Cushing. The proximal interphalangeal joint is most commonly involved. It can be hereditary or nonhereditary.

Symphangilism is also known to be associated with many syndromes like Apert and Poland. It is also associated with syndactyly.

It could be a hereditary or nonhereditary condition. Hereditary symphalangism is usually inherited as a dominant trait.

It is most frequently seen in Caucasians. It is less common in Orientals and even lesser in blacks.

Symphalangism can result in can be functional impairment in the grip and pinch actions of the affected hand as well as cosmetic issues.

The proximal interphalangeal joint of the hand is the most common site of involvement.

Contents hide
1 Causes, Pathophysiology and Grading of Symphlangism
2 Clinical Presentation
3 Imaging
4 Treatment of Symphalangism
5 References

Causes, Pathophysiology and Grading of Symphlangism

Symphalangism occurs due to the failure of separation of the phalanges which then remain in fused condition. It may occur as a simply isolated malformation or it may be associated with other deformities of the hands or feet, and it may also occur in numerous congenital syndromes such as Apert’s, Poland and Mobius syndrome.

NOG gene or noggin gene has been related to the most cases of symphalangism. Mutations in GDF 5 [growth and differentiation factor 5] have also been associated.

An Attempt has been made to classify symphalangism based on radiographic appearance.

This classification is as follows

  • Grade I or Fibrous – Mild joint space narrowing in the affected joint
  • Grade II or Cartilaginous Symphalangism – Only a line of joint space is observed.
  • Grade III or Bony Symphalangism- Visible bony ankylosis
Grades of Symphalangism
Grades of Symphalangism, A -Normal Joint, B- Fibrous Symphalangism, C-Cartilaginous Symphalangism, D – Bony Symphalangism, Image Credit: Baek etal

In a very young child, over the involved joint,  volar skin crease may be absent or faint. Joint capsule and ligaments may be tight, allowing minimum motion of the affected joint. As the joint grows, it may fuse.

Thus, the same joint can be classified as fibrous, cartilaginous, or bony symphalangism according to the child’s age at diagnosis.

Clinical Presentation

The congenital stiffness of the digits is the main presentation.

It could be spotted by the parents when the child attempts to grasp something. The patient would not make a fist properly. Older children have difficulty in difficulty picking up small objects.

On examination, there would be lack of motion of the affected joint in the finger. The skin overlying the fused articulation is smooth, and the transverse skin creases are absent.

This condition can be easily detected at birth.

Usually, more than one finger is affected. When the proximal interphalangeal joint is affected, the digit is usually fixed in extension. At the level of the fused joint, the soft tissues are narrowed.

Imaging

The x-rays are used to grade the symphalangism as marked by the narrowing of the interphalangeal joints. But as mentioned before, the age of the child needs to be considered too as the grade of the symphalangism may progress as the child grows older.

So it possible that one is not even able to detect the condition radiographically at birth because of a lack of ossification of the phalanges around the affected joint. With growth and maturation, when the bones ossify, there is a decrease in the joint width with eventual fusion.

Treatment of Symphalangism

Treatment needs to be individualized.

Very young children should not be operated. Most of the children have limited functional hampering and may not need surgery at all.

Soft tissue procedures provide maximum benefit when performed before 3 years of age. Arthrodesis and interphalangeal joint arthroplasty should only be considered after the skeletal maturity has been reached.

The various surgical options are

  • Operative capsulectomy  – It has limited success
  • Angular osteotomy- For example, the digits that are fixed in extension will be functionally improved by flexion osteotomy.Rarely needed
  • Arthrodesis
    • During adolescence only

Other procedures that may be required are correction In symbrachydactyly [ associated shortening of the fingers].

The digits may be needed to be lengthened surgically

Recent reports have suggested that the early release of the fusion when it is in fibrous stage may restore some motion. The child should be operated for this as early as possible.

The management of symphalangism with associated anomalies is complex. One should individualize the care; often it is difficult to improve function.

References

  • Takahashi T, Takahashi I, Komatsu M, et al. Mutations of the NOG gene in individuals with proximal symphalangism and multiple synostosis syndrome. Clin Genet. 2001;60(6):447–451.
  • Baek GH, Lee HJ. Classification and surgical treatment of symphalangism in interphalangeal joints of the hand. Clin Orthop Surg. 2012;4(1):58-65. doi:10.4055/cios.2012.4.1.58. Link

Save

Pediatric ortho This article has been medically reviewed by Dr. Arun Pal Singh, MBBS, MS (Orthopedics)

About Dr Arun Pal Singh

Dr. Arun Pal Singh is a practicing orthopedic surgeon with over 20 years of clinical experience in orthopedic surgery, specializing in trauma care, fracture management, and spine disorders.

BoneAndSpine.com is dedicated to providing structured, detailed, and clinically grounded orthopedic knowledge for medical students, healthcare professionals, patients and serious learners.
All the content is well researched, written by medical expert and regularly updated.

Read more....

Primary Sidebar

Know Your Author

Dr. Arun Pal Singh is an orthopedic surgeon with over 20 years of experience in trauma and spine care. He founded Bone & Spine to simplify medical knowledge for patients and professionals alike. Read More…

Explore Articles

Anatomy Anatomy Fractures Fractures Diseases Diseases Spine Disorders Spine Disorders Patient Guides Patient Guides Procedures Procedures
featured image for orthopedics traction

Orthopedic Traction – Principles, Types, and Uses

Traction is a fundamental concept in orthopedics for managing …

featured image of gower sign for segmenatal instability of lumbar spine

Clinical Tests for Lumbar Segmental Instability

Lumbar segmental instability may not always be visible on standard …

mesurement of scoliosis for braces

Braces for Scoliosis- Types, Uses and Results

Braces for scoliosis are recommended to prevent the scoliotic curve …

discogenic back pain

Discogenic Back Pain Causes, Diagnosis and Treatment

Discogenic back pain is a common cause of axial low back pain [the …

Elbow arthrodesis using internal fixation

Elbow Arthrodesis- Indications, Methods and Complications

Elbow arthrodesis refers to the surgical fusion of the elbow joint. It …

Popular articles

tillaux fracture

Ankle Fractures and Dislocations Injuries

Ankle fractures are actually groups …

upper limb and its divisions

Upper Limb Anatomy and Function – Structure, Muscles, Nerves

The upper limb in humans has evolved …

Hip arthrodesis image

Hip Arthrodesis – Indications and Procedure

Hip arthrodesis is a procedure where hip …

foods for healthy bones

Foods for Healthy Bones- Sources and Requirement

Doctor! What are foods for healthy …

Bone and Spine

© 2025 BoneAndSpine.com · All Rights Reserved
The content provided on BoneAndSpine.com is intended for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Read Disclaimer in detail.