Last Updated on January 31, 2024
The Darrach procedure is the removal of the distal ulna. It was first performed by Darrach in 1911 in New York City. Darrach Procedure is done for
- For relief of pain following distal radioulnar disruption and/or radioulnar arthritis;
- For symptomatic malunion of Colle fracture in elderly patients, especially when stiffness is present
Darrach procedure is generally performed on elderly patients with low functional demands. Young pts with symptomatic instability of the distal radioulnar joint may have better results with distal radial osteotomy and with the restoration of length & alignment, or when this is not possible then consider hemi-resection arthroplasty.
The procedure is named after William Darrach, who 1912 described its use in treating volar dislocation of the distal radioulnar joint after trauma.
Relevant Anatomy
Credit: ResearchGate
The distal ulna is formed by a small rounded head and an ulnar styloid process. The head of the ulna articulates with the ulnar notch of the distal radius via the lateral convex articular surface to form the distal radioulnar joint.
The distal surface of the head articulates with an articular disc called the triangular fibrocartilage. This disc separates the head from the wrist bones.
The ulnar styloid process projects distally from the posteromedial aspect of the distal ulna. This projection can be palpated at the dorsoulnar aspect of the wrist.
The dorsal sensory branch of the ulnar nerve lies in the subcutaneous tissue of the dorsal ulnar wrist. This is important to remember during surgical approach.
Indications of Darrach Procedure
- Distal radioulnar joint arthritis: distal radioulnar joint arthritis can develop due to inflammation, osteoarthritis, or trauma to the joint.
- Distal ulna fracture: Those fractures of the distal ulna that cannot be reconstructed or have failed to unite after reconstruction can be considered for this procedure.
It must be emphasized that the Darrach procedure works better in cases of rheumatoid arthritis than other arthritides.
Contraindications
Following are the relative contraindications and if present, the procedure should be carefully considered.
- Ulnar translocation: It is a type of wrist instability where the carpus shifts to the ulnar side
- Distal radioulnar joint instability: The procedure is contraindicated if the instability is present with arthritis[except in cases of rheumatoid arthritis where it can be done]
Preoperative Workup
The affected wrist should be thoroughly examined. Clinical examination should assess active and passive wrist motion and compare with the opposite side. If there is pain and crepitus during pronation and supination and it gets increased in intensity by manual compression, it indicates distal radioulnar joint arthritis.
Other conditions that need to be differentiated are
- Extensor carpi ulnaris subluxation – The tendon suluxates with supination and pronation
- Lunotriquetral instability
The examination is followed by X-ray imaging. The Standard three views of the wrist are posteroanterior, posteroanterior oblique, and lateral. X-rays are useful to assess the extent of arthritis and wrist stability.
CT and MRI are typically not required.
Technique of Darrach Procedure
Darrach procedure is performed by dorsal approach by the longitudinal incision is made over the distal ulna. It involves resection of 1-2 cm of ulna.
Frequently, the Darrach procedure is performed in conjunction with other procedures such as inflammatory arthropathies. In this situation, the surgical incision is usually dorsal midline longitudinal, which enables all aspects of the wrist reconstruction like wrist fusion, arthroplasty, tenosynovectomy, tendon transfer, etc.
If the Darrach procedure is to be performed independently, a single oblique or chevron dorsal approach is made overlying the fifth dorsal compartment.
A capsulotomy deep into the fifth dorsal compartment is performed.
Osteotomize the distal ulna using a power oscillating saw just proximal to the sigmoid notch. Keep resection to 2 cm or less. Some authors recommend cutting a tapered cut at about 45 degrees in a way that the ulnar side of the ulna is slightly longer.
There are various modifications/additional procedures that have been mentioned to address soft tissue challenges after the Darrach procedure. Some commonly used are
- Bower’s modification
- Only a portion of the distal ulna is removed
- Radioulnar and ulnar carpal ligaments and triangular fibrocartilage attachment not removed
- Interposition of tendon, muscle, or dorsal capsule in the resected area. He labeled this procedure the hemiresection interposition arthroplasty.
- Tapering distal ulna into pencil-shape
- Tenodesis
- Using extensor carpi ulnaris
- Using pronator quadratus
Intraoperative fluoroscopic guidance is frequently helpful to assist with the location of the osteotomy.
The entire styloid should be removed with the distal ulna.
The idea is to respect the minimum possible the least amount of bone is excised which is sufficient to restore full motion. If the ulna appears unstable after resection, it may be stabilized by the tendon of the extensor carpi ulnaris.
Complications
- Instability of the distal ulnar shaft
- Painful subluxation of the extensor carpi ulnaris over the transected end
- Palmar or ulnar subluxation of the carpal bones
- Radio-ulnar impingement (Bones converge together)
Prognosis
Darach procedure gives satisfactory results in elderly patients with minimal physical demands. patient selection is very important. Most of the issues after the procedure occur due to wrong patient selection and too much cutting of the distal ulna.
Patients of rheumatoid arthritis respond better than other kinds of osteoarthritis.
References
- Carl HM, Lifchez SD. Functional and Radiographic Outcomes of the Sauvé-Kapandji and Darrach Procedures in Rheumatoid Arthritis. J Hand Microsurg. 2019 Aug;11(2):71-79. [Link]
- Verhiel SHWL, Özkan S, Ritt MJPF, Chen NC, Eberlin KR. A Comparative Study Between Darrach and Sauvé-Kapandji Procedures for Post-Traumatic Distal Radioulnar Joint Dysfunction. Hand (N Y). 2021 May;16(3):375-384.[Link]
