• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Home
  • About
  • Newsletter/Updates
  • Contact Us
  • Policies

Bone and Spine

Orthopedic health, conditions and treatment

  • General Ortho
  • Procedures
  • Spine
  • Upper Limb
  • Lower Limb
  • Pain
  • Trauma
  • Tumors

Ulnar Impaction Syndrome or Ulnocarpal Abutment

By Dr Arun Pal Singh

In this article
    • Relevant Biomechanics of Wrist Joint
    • Causes of Ulnar Impaction Syndrome
    • Clinical Presentation
    • Differential Diagnoses
    • Imaging
    • Treatment of Ulnar Impaction Syndrome
      • Nonoperative Treatment
      • Operative Treatment
    • References
      • Related

Ulnar Impaction Syndrome is a degenerative wrist condition caused by the ulnar head impacting upon the ulnar-sided carpus and triangular fibrocartilage complex resulting in degeneration of these structures and a spectrum of symptoms.

It is also called ulnocarpal abutment, ulnocarpal loading, and impingement syndrome.

Ulnar impaction syndrome is a common cause of ulnar sided wrist pain.

It is a degenerative condition that occurs secondary to excessive load across the ulnocarpal joint, but the demographics and the natural history of ulnar impaction syndrome.

Relevant Biomechanics of Wrist Joint

Distal Radio Ulnar Joint
Distal Radio Ulnar Joint

Abutment of the distal ulna with the carpus often results in pain and progressive deterioration of the triangular fibrocartilage complex (TFCC) and other pathologic changes. These changes are can be noted in following structures-

  • Dome of the ulnar head
  • Ulnar corner of the lunate
  • T triquetrum
  • Lunotriquetral interosseous ligament [LTIL]

In the ulnar neutral wrist [ulnar neutral wrist is where the ulnar variance is less than 1mm], about 18% load is borne by the ulnocarpal joint bears. Triangular fibrocartilage is an important structure in the wrist that transfers the load from carpal bones to the ulna. Thicker triangular cartilage increases the load transfer whereas thinner cartilage transfers the lesser load.

Those with negative congenital negative ulnar variance have thicker TFCC and thus allows the load transfer effectively.

Thus ulnar variance or length of the ulna is an important factor. Increasing or decreasing the relative length of the ulna has been shown to cause significant changes in ulnocarpal load.

This rationale is used for the ulnar-shortening osteotomy in the treatment of ulnar impaction syndrome.

Thus, the ulnar impaction syndrome is less common in people with negative to neutral ulnar variance.

During forearm movements, pronation and grip both result in a relative increase in ulnar length which creates a dynamic positive ulnar variance resulting in the ulnocarpal load.

It has been suggested that the dynamic increase in relative ulnar length during pronation and grip leads to dorsal subluxation of the ulnar head in ulnar positive wrists.

Causes of Ulnar Impaction Syndrome

Ulnar impaction syndrome is more commonly seen in patients who have got an increased ulnar variance. Common conditions where this is seen are

  • Distal radius fractures with radial shortening
  • Radial head excision
  • Essex Lopresti fracture
  • Galeazzi fracture
  • Dynamic positive ulnar variance [Due to excessive repeated loading of the ulnar-carpus in daily activities, refer to the explanation above]
  • Madelung deformity

Clinical Presentation

Most of the patients of ulnar impaction syndrome have the pain of insidious onset. However, there are some patients who in spite of abutment would have minimal or no symptoms.

The patients are generally middle-aged. Those with idiopathic ulnar impaction syndrome could be of younger age

The pain is often progressive. There may be complaints of swelling and stiffness of wrist and forearm rotation.

The activities of forceful grip, pronation, and ulnar deviation worsen the symptoms.

[These movements cause an increase in ulnar variance.]

A complete wrist examination should be carried to rule out other causes and establish a diagnosis. There are some special tests for the ulnocarpal abutment. These are

Nakamura’s Ulnocarpal Stress Test

This test involves placing the wrist in maximum ulnar deviation, axially loading the wrist, and passively rotating the forearm through supination to pronation.

Reproduction of the typical pain pattern is considered as positive and is suggestive of ulnar impaction syndrome.

The test is very sensitive for ulnar impaction syndrome. But a number of other processes like

  • Lunotriquteral injury [LTIL injury]
  • TFCC injury (without impaction)

Regan Shuck Test

With the wrist positioned in ulnar deviation, dorsal and palmar displacement of the ulna is attempted. The test is considered positive if the pain is produced. This test is done to know LTIL injury.

Fovea test

This test is done to evaluate for TFCC tear or ulnotriquetral ligament tear. The test is performed by palpation of the ulnar wrist between the styloid and flexor carpi ulnaris tendon.  Tenderness suggest positive test.

Differential Diagnoses

Conditions that cause ulnar sided wrist pain should be considered as differential diagnoses. These commonly include

  • Pisotriquetral arthritis
  • Distal radioulnar joint or DRUJ arthrosis
  • Extensor carpi ulnaris subluxation or tendonitis
  • Dorsal cutaneous branch [of the ulnar nerve] neuritis

Imaging

Cyst formation in lunate following Ulnar Impaction Syndrome
Cyst formation in lunate following Ulnar Impaction Syndrome, image credit: Musculoskeletal key

X-rays

X-rays are normal in early disease. A positive ulnar variance may be noted. Degenerative changes in the ulnar side of the carpal bones may be noted when the condition advances.

X-rays should also be evaluated for any probable pathology that could lead to acquired positive ulnar variance. Comparison radiographs of the other side are often helpful.

Neutral rotation posterior-anterior wrist x-ray is done for determining the ulnar variance. The image is taken with the elbow flexed at 90 degrees and the forearm in neutral rotation.

Lateral x-rays should be evaluated for evidence of dorsal ulnar subluxation

Following changes may be noted in the x-ray.

  • Subchondral sclerosis
  • Cystic changes at the dome of the ulna
  • Cystic changes in the proximal ulnar corner of the lunate
  • Cystic changes in the proximal radial corner of the triquetrum
  • Frank arthritis in severe cases
  • Ulnar subluxation

MRI

MRI is not required for diagnosis. But in cases where the diagnosis is not clear, MRI may provide detailed images of the structures involved. it also shows occult pathologies.

The earliest detectable changes are noted in the articular cartilage and are fibrillation and chondromalacia,.

The other lesions are bone hyperemia or edema, localized to the involved regions, may also be evident

MRI is also able to rule out other possible sources of ulnar-sided wrist pain.

MR arthrography may be useful in select cases to ascertain the exact stage of ulnar impaction in pre-operative evaluation.

Treatment of Ulnar Impaction Syndrome

Treatment of ulnar impaction syndrome varies depending on the amount of ulnar variance, and the severity of pathological changes, the contour of the distal ulnar and the presence of lunotriquetral instability.

Nonoperative Treatment

Initial treatment should be nonoperative in most cases. It incldeus

  • Rest or immobilization for 6 to 12 weeks
  • Modification of activities
  • NSAIDs
  • Local steroid injections

Operative Treatment

Surgery can be considered if the above modalities fail to work.

The goal of surgery for ulnar impaction syndrome is to decrease the length of the ulna relative to the radius. This leads to a decrease in the amount of load that crosses the ulnocarpal joint.

Ulnar-shortening osteotomy and the wafer procedure are two main surgeries for this.

Ulnar head excisional osteotomies have been described. These effectively shorten the ulnar head while preserving the domal cartilage.

In presence of distal radioulnar joint arthritis [DRUJA], the procedure should address both, DRUJA and the ulnar impaction syndrome.

These procedures include endoprosthetic ulnar head arthroplasty, Bowers’ hemiresection arthroplasty, matched distal ulna resection arthroplasty, the Darrach procedure, and the Sauve-Kapandji procedure.

Briefs of some common procedures is given below.

 

Ulnar Shortening Osteotomy

First described by Milch in 1941, this osteotomy is still considered the gold standard

It should be preferred over wafer procedure in-

  • A wrist with positive ulnar variance and a prominent ulnar styloid
  • Ulnocarpal abutment with dorsal subluxation of the ulna.

The osteotomy is performed at the junction of the distal and middle third of the ulna.

Ulnar shortening should be avoided in patients with DRUJ arthritis, and in patients with a reverse oblique DRUJ slope.

Delayed union or nonunion, and hardware-related complications may occur after this procedure.

Wafer Procedure

The wafer procedure refers to resection of distal 2–3 mm of the dome of the ulnar head.

This can be done as an open procedure or arthroscopy.  It allows rapid return to normal activities.

It is effective for decreasing the ulnocarpal load.

It avoids the complications of ulnar shortening osteotomy and can be done in DRUJ with reverse slope. But the resection is limited to 2-3 mm.

Unlike osteotomy, It does not improve dorsal subluxation of the ulna, and it does not tighten the ulnocarpal ligamentous complex.

Darrach Procedure

Complete or partial ulnar head resection. Done in advanced lesions.

Sauve´ – Kapandji procedure

Arthrodesis of the distal radioulnar joint with distal ulnar pseudoarthrosis

Radial Osteotomy

When ulnocarpal impaction occurs following fractures of radius, the procedure can restore normal joint anatomy. This approach fixes the culprit bone rather than doing a compensation procedure on the other bone.

References

  • Pfaeffle HJ, Manson T, Fischer KJ. Axial loading alters ulnar variance and distal ulna load with forearm pronation. Pittsburgh Orthop J 1999;10:101–2.
  • Nishiwaki M, Nakamura T, Nagura T, et al. Ulnar-shortening effectondistal radioulnar jointpressure:a biomechanical study.
  • Jung JM, Baek GH, Kim JH, et al. Changes in ulnar variance in relation to forearm rotation and grip. J Bone Joint Surg Br 2001;83(7):1029–33. 16. Kristensen SS, Thomassen E, Christensen F. Ulnar variance determination. J Hand Surg Br 1986; 11(2):255–7.
  • Feldon P, Terrono AL, Belsky MR. Wafer distal ulna resection for triangular fibrocartilage tears and/or ulna impaction syndrome. J Hand Surg Am 1992; 17(4):731–7.
  • Baek GH, Chung MS, Lee YH, et al. Ulnar shortening osteotomy in idiopathic ulnar impaction syndrome. J Bone Joint Surg Am 2005;87(12):2649–54.
  • Watson HK, Ryu JY, Burgess RC. Matched distal ulnar resection. J Hand Surg Am 1986;11(6):812–7. 35.

Related

Spread the Knowledge
10
Shares
 
10
Shares
19   

Filed Under: Hand and Upper Limb

About Dr Arun Pal Singh

Arun Pal Singh is an orthopedic and trauma surgeon, founder and chief editor of this website. He works in Kanwar Bone and Spine Clinic, Dasuya, Hoshiarpur, Punjab.

This website is an effort to educate and support people and medical personnel on orthopedic issues and musculoskeletal health.

You can follow him on Facebook, Linkedin and Twitter

Primary Sidebar

Browse Articles

X-ray of Legg CalvePerthes Disease

Legg Calve Perthes Disease – Clinical Presentation and Treatment

Legg Calve Perthes disease is an idiopathic avascular necrosis of the proximal femoral epiphysis in children resulting from compromise of the tenuous blood supply to this area. Legg Calve Perthes disease usually occurs in children aged 4-10 years. Mean age is 7 years. Mostly, the disorder is unilateral. It affects 1 in 10,000 children with a male to […]

Olecranon Bursitis

Olecranon Bursitis Presentation and Treatment

Olecranon bursitis is inflammation of olecranon bursa which is a subcutaneous bursa overlying the olecranon process of the ulna. Bursa functions to reduce the friction between olecranon and skin. Olecranon bursitis may result from inflammation caused by various factors like repetitive trauma and infection of the bursa. Normally, olecranon bursa is Superficial locations of the […]

xray after Girdlestone arthroplasty

Girdlestone Procedure or Excision Arthroplasty of Hip

Girdlestone procedure is excision arthroplasty of the hip in which femoral head, neck, proximal part of the trochanter and the acetabular rim are removed. The procedure was described for chronic deep-seated infections of the hip joint. After the surgery patient is put on skeletal traction followed by gradual mobilization. Girdlestone procedure also goes by name […]

Congenital scoliosis is type of nonidiopathic scoliosis Image Credit: SRS

Nonidiopathic Scoliosis – Types and Causes

Idiopathic structural scoliosis is the most common type of scoliosis. Rest of the scoliosis types are grouped under the term nonidiopathic scoliosis. Nonstructural scoliosis has the lateral curvature but there is no structural abnormality in the spine. The curvature is in response to habit or a disease process like inflammation. Postural scoliosis is a type […]

Refracture Humerus

Shaft of Humerus Fracture Diagnosis and Treatment

The shaft of humerus fracture is the fracture of humerus bone that lies between the proximal and distal part of the humerus. This part lies between the upper border of the pectoralis major insertion proximally and the supracondylar ridge distally. The shaft of the humerus constitutes the middle three-fifths of the entire humerus. Relevant Anatomy […]

Bone Mineralization

Bone Mineralization Process

Bone mineralization is the process of laying down minerals on a matrix of the bone. Normal bone is composed of 50 to 70% mineral, 20 to 40% organic matrix, 5 to 10% water, and <3% lipids. Calcium and phosphorus are chief minerals found in the bone along with small amount of carbonate, magnesium. The mineral […]

Radiolunate Angle

Wrist Instability Types, Diagnosis and Treatment

Wrist Instability or carpal instability occurs when takes wrist is damaged by trauma, chronic inflammation or anatomical alterations like ulnar variance and neoplasms. Injuries to the ligaments of the wrist represent a broad spectrum of pathology. There are a number of ligaments of the wrist maintaining a complex articulation of carpal bones. Ligament injuries are […]

© Copyright: BoneAndSpine.com
Manage Cookie Consent
The site uses cookies. Please accept cookies for a better visiting experience.
Functional Always active
The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network.
Preferences
The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user.
Statistics
The technical storage or access that is used exclusively for statistical purposes. The technical storage or access that is used exclusively for anonymous statistical purposes. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you.
Marketing
The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes.
Manage options Manage services Manage vendors Read more about these purposes
View preferences
{title} {title} {title}
 

Loading Comments...