Intersection Syndrome

Original Editors - Emilie Depasse

Top Contributors - Kim Jackson, Lucinda hampton, Emilie Depasse, Evan Thomas, Vidya Acharya and Wanda van Niekerk

Introduction

Intersection syndrome is a condition that affects the first and second compartments of the dorsal wrist extensors. The condition is thought to occur as a result of repetitive friction at the junction in which the tendons of the first dorsal compartment cross over the second, creating a tenosynovitis. This is typically noted as a pain just proximal and dorsal to the radial styloid, or also noted anatomically by 4 cm - 6 cm proximal to Lister's tubercle

The term "intersection syndrome" refers to the intersection (at an angle of around 60°) of the musculotendinous junctions of the first and second extensor compartment tendons.

The intersection syndrome is a relative uncommon disorder that is often misdiagnosed with other conditions, such as ‘De Quervain’s tenosynovitis.

Pathology

The musculotendinous junctions of the first extensor compartment tendons (abductor pollicis longus and extensor pollicis brevis tendons) intersect the second extensor compartment tendons (extensor carpi radialis longus and extensor carpi radialis brevis tendons).

This intersection is at an angle of approximately 60°, approximately 4 cm proximal to Lister's tubercle (a bony protuberance on the dorsal surface of the distal radius).

In intersection syndrome there is tenosynovitis particularly of the second extensor compartment possibly caused by friction from the overlying first compartment tendons

The presentation is typically one that the patient complains of pain or tenderness over the dorsal aspect of the wrist proximal to the radial styloid. There may also be swelling and crepitus that is palpable on the exam with wrist and/or thumb extension

Epidemiology

The syndrome is typically the result of repetitive extension and flexion exercises or activities. It is commonly seen in sporting activities such as rowing or canoeing, skiing, racquet sports, and horseback riding. There is no significant difference in injury pattern found in men versus women

Characteristics/Clinical Presentation

Radial wrist or forearm pain are the complaints of patients with the intersection syndrome. Repetitive wrist flexion and extension may exacerbate the symptoms. [2]

Symptoms:

• Pain and swelling in the area of 7 cm of the distal radius
• Erythema
• Edema
• Tenderness to palpation
• Crepitance with flexion and extension of the wrist [2] [3] [4] [6] [7]

Differential Diagnosis

• De Quervain tenosynovitis (first extensor compartment involvement only, located more distal at the radial styloid)
• Muscle strain
• Entrapment of the dorsal radial sensory nerve as it emerges beneath the brachioradialis (Wartenberg’s syndrome)
• Thumb CMC arthritis
• Extensor pollicis longus (EPL) tendinitis

Examination

On examination , swelling at the site of intersection is frequently present. Active or passive wrist motion creates a crepitus.

The Finkelstein’s test resulted in uneasiness. The Finkelstein’s test is a passive stretch test with ulnar abduction and flexion of the thumb. [1] [3][4]

Medical Management

The diagnosis is often made clinically but may be found when wrist and forearm pain is investigated with MRI. [1] [2]

Surgery is only required in case of persisting symptoms after an already adequate course of conservative treatment. [1] [4]

Surgery is contraindicated in patients with vague nonspecific complaints or in those patients who have not received or been compliant with recommended unoperative measures.

Physical Therapy Management

The intersection syndrome is usually managed conservatively.
The first step of this management includes modification of work and sport activities, which will help to reduce stress on the wrist and splinting. Secondly oral nonsteroidal inflammatory medication or local ice-pack placement can also reduce pain. [4]

Conservative management with immobilization (a neutral position with a splint), an activity change and anti-inflammatory medication is normally appropriate to control the symptoms.

A research proved that taping can eliminate crepitus. In this research was found that crepitus induced by wrist movements, swelling and tenderness over the dorsal forearm were no longer present at 3-week follow-up. [5]

The physical therapist will have to start with the conservative treatment. [5]
If there is no change of activity the conservative treatment will not rehabilitate the intersection syndrome. In this case, surgery can be required. [8]

Physiotherapy after a surgical intervention for this syndrome is necessary and can proceed the rehabilitation process. Physical therapy after a surgical intervention includes a process of therapeutic exercises, joint mobilization, scar mobilization, soft tissue massage, stretching and physical agents. Another very important aspect for a worthy rehabilitation contains the patient education concerning activity modification; management of playing an instrument etc. The patient has to maintain a faultless posture for example while using a computer keyboard. [8]

References

1. Costa CR, Morrison WB, Carrino JA. MRI features of intersection syndrome of the forearm. AJR Am J Roentgenol. 2003 Nov;181(5):1245-9. [Level of Evidence: A1]
2. de Lima JE, Kim HJ, Albertotti F, Resnick D. Intersection syndrome: MR imaging with anatomic comparison of the distal forearm. Skeletal Radiol. 2004 Nov;33(11):627-31. Epub 2004 Sep 10. [Level of evidence: A2 ]
3. Descatha A, Leproust H, Roure P, Ronan C, Roquelaure Y. Is the intersection syndrome is an occupational disease? Joint Bone Spine. 2008 May;75(3):329-31. Epub 2007 Aug 31. [Level of evidence: C]
4. Hanlon DP, Luellen JR. Intersection syndrome: a case report and review of the literature. J Emerg Med. 1999 Nov-Dec;17(6):969-71. [Level of evidence: C]
5. Kaneko S, Takasaki H. Forearm pain, diagnosed as intersection syndrome, managed by taping: a case series. [Level of evidence: C ]
6. Lee RP, Hatem SF, Recht MP. Extended MRI findings of intersection syndrome. Skeletal Radiol. 2009 Feb;38(2):157-63. Epub 2008 Sep 23. [Level of evidence: A1]
7. Lui TH, Chow FY. "Intersection syndrome" of the foot: treated by endoscopic release of master knot of Henry. Knee Surg Sports Traumatol Arthrosc. 2011 May;19(5):850-2. Epub 2011 Feb 3. [Level of evidence: C ]
8. Robinson BS, Rehabilitation of a cellist after surgery for de Quervain's tenosynovitis and intersection syndrome, Medical problems of performing artists Volume: 18 Issue: 3 Pages: 106-112 Published: SEP 2003 [Level of evidence: C]
9. Rumball, Jane S.1; Lebrun, Constance M.; Ciacca, Stephen R. Di; Orlando, Karen. Rowing Injuries. Sports Medicine, Volume 35, Number 6, 2005 , pp. 537-555(19)
[Level of evidence: A1]