Arthroscopic Release of Wrist Contracture

Published on 16/03/2015 by admin

Filed under Orthopaedics

Last modified 22/04/2025

Print this page

This article have been viewed 2304 times

CHAPTER 52 Arthroscopic Release of Wrist Contracture

Joseph Bergman, MD, Gregory Bain, MBBS

Rationale and Basic Science Pertinent to the Procedure

Wrist contracture is a difficult problem with significant clinical implications. It has a variety of causes with trauma to the distal radius and carpus being the most common. The authors recommend that the wrist contracture be classified as extra-articular, capsular, or intra-articular. Extra-articular causes include heterotopic bone and changes in joint orientation, as might be seen after an extra-articular distal radius fracture; intra-articular causes include intra-articular distal radius or carpal fractures and carpal instability. Extra-articular and intra-articular pathology should be dealt with to address these sources of wrist stiffness.

Causes of capsular stiffness include fractures, surgery, arthritis, and immobilization to the wrist. In cases of capsular stiffness, initial treatment should include physiotherapy directed at stretching and splinting. In most cases, this regimen yields satisfactory results.

In refractory cases, surgical intervention may be warranted given the effectiveness of the technique when used with other joints.¹^–⁵ Open and arthroscopic techniques have been described for the wrist, although there is a paucity of literature regarding clinical outcomes. Nonetheless, for cases where conservative management is inadequate, there seems to be a role for surgical management. In cases in which the source of the restriction in motion is the capsule, release or resection of the capsule would provide an increased range of motion, much as it does in other cases of arthrofibrosis.

Anatomy

Numerous nerves and blood vessels traverse the wrist joint. Their proximity is important in choosing arthroscopic portals and during release of contractures. The ulnar and median nerves and the radial artery are most at risk during this procedure, and their proximity to the capsule is relevant to the safety of the release (Fig. 52-1).

FIGURE 52-1 Cadaver cross section showing the relative locations of the major neurovascular structures of concern, including the ulnar nerve (UN), the median nerve (MN), and the radial artery (RA).

Used with permission from The Journal of Arthroscopic and Related Surgery, Vol 16, No. 1 (Jan-Feb), 2000.

Ulnar Nerve

The ulnar nerve is at risk in many of its branches for portal selection and in its proximity to the ulnar volar joint capsule. It courses from beneath the flexor carpi ulnaris to the radial side of the tendon, and passes radial to the pisiform at an average distance of 6 mm (range 4 to 12 mm). Because the ulnar carpal ligaments are left untouched in this procedure, the ulnar nerve is principally of issue with respect to portal placement.

The ulnar nerve has two significant superficial branches, which originate approximately 10 cm proximal to the wrist joint—the dorsal cutaneous branch, and the volar cutaneous branches of the ulnar nerve. Placement of the 6R portal should be done using blunt dissection to avoid injury to the dorsal superficial ulnar cutaneous nerve. The portal should be placed in the proximal fifth (19%) of an imaginary line drawn from the ulnar styloid to the fourth web space.⁶

Median Nerve

The median nerve’s course on the central volar aspect of the wrist within the carpal tunnel places it away from the joint capsule. It is the most superficial structure within the carpal tunnel and sits 13 mm underneath the skin surface.⁷ It passes an average of 6.9 mm volar to the volar wrist capsule and at closest, 4 mm.⁸ The median nerve passes radially within the carpal tunnel and is, on average, 18 mm radial to the pisiform and 8 mm ulnar to the scaphoid tubercle. It is protected by the mass of the finger flexors during capsular excision.

Radial Artery

The radial artery is located radially to the flexor carpi radialis tendon and sheath. It is at least 3 mm away from the volar radial capsule (average >5 mm). During capsular release, the radial artery is the structure most at risk, but careful division of the radioscaphocapitate ligament and the long radiolunate ligaments avoids the artery.

Indications

An arthrofibrotic wrist in which stiffness is the principal presenting complaint is most appropriate for arthroscopic release of the wrist capsule. Patients for whom stiffness is not the dominant symptom are not ideal.

Ideal Candidate

The ideal candidate for arthroscopic capsular release is a patient with functional loss of range of motion and for whom conservative therapy, including splinting, has failed. There is no upper limit to timing, but the joint should have stabilized in terms of pathology and range of motion before initiating any surgical release. In practice, this should be at least 6 months from the time of injury.

Capsular contracture should be diagnosed as the origin of the stiffness, and bony architecture should be ruled out as a reason for limitation of motion. There should be normal articular cartilage with a normal anatomical joint surface. Stiffness should be the sole reason for the contracture, with a painless but limited range of motion. Lastly, there should not be a generalized arthropathy likely to lead to recurrence of stiffness.

Contraindications

Absolute Contraindications

There is a risk to vital neurovascular structures during portal placement and capsular release. The volar portals and capsular release procedures should be considered advanced techniques that should be performed only by trained and experienced surgeons. Training on cadaver specimens is recommended before performing these procedures.

Significant prior soft tissue–distorting trauma or surgery that would preclude a safe procedure would be a contraindication. Previous compound fractures may have distorted anatomy. Global contraindications include active infection, compromised or lacerated skin overlying the wrist, and general contraindications to anesthesia.

Relative Contraindications

As described previously, in any situation in which the joint stiffness is due to multiple factors, capsular release alone is unlikely to provide significantly improved range of motion and is likely to recur. A painful joint or one where the joint architecture or articular surface is compromised is a relative contraindication. Complex intra-articular fractures with carpal instability are unlikely to improve with a capsular release.

Surgical Technique

A standard arthroscopic setup is used.⁹ The patient is supine, with a tourniquet and finger traps. A 5-kg weight to distract the joint is used to assist in visualization. A 2.7-mm arthroscope is used in most cases, although a 1.9-mm arthroscope can be used in a smaller or more restricted joint. Using the 3,4 and 6R working portals, diagnostic arthroscopy and débridement are performed.

Volar Capsular Release

There is often synovitis on the volar capsule that should be débrided to improve visualization and make subsequent capsular release easier. To perform the capsular release, a hooked electrocautery probe is introduced through the 6R portal and advanced in a radial direction as far as possible. Cautery is used to divide the volar capsule and volar carpal ligaments as shown in Figure 52-2. The long and short radiolunate ligaments, the radiocapitate ligament, and part of the radioscapholunate ligament are divided. Figure 52-2 also shows the division of the volar capsule down to periarticular fat. Based on the work of Viegas and colleagues,¹⁰ the authors believe that leaving part of the radioscaphocapitate ligament intact is important to prevent the potential complication of ulnar translocation of the carpus. We have not seen this complication, but predict that it could occur, and that it would be extremely difficult to treat.

FIGURE 52-2 Video frame showing division of the volar extrinsic ligaments with the use of electrocautery. Note the pericapsular fat seen adjacent to the divided ligaments.

The triangular fibrocartilaginous complex is left intact, including the ulnotriquetral and ulnolunate ligaments. Division of the radial side of the volar capsule should continue until the flexor carpi radialis tendon is seen, and extracapsular fat is exposed. The surgeon must not delve into this volar periarticular fat because this may lead to significant neurovascular injury. Distances to important anatomical structures are shown in Table 52-1. Although the median and ulnar nerves are at least 4 mm away from the capsule, the radial artery can lie as close as 3 mm to the radial volar capsule.

TABLE 52-1 Distance from the Radiocarpal Joint Capsule: Results from Magnetic Resonance Imaging Scans and Cadaver Sections

Structure	Average (mm)	Range (mm)
Median nerve	6.9	4-9
Ulnar nerve	6.7	4-9
Radial artery	5.2	3-7

After release of the volar capsule, the joint is taken through a range of motion to assess whether a satisfactory range has been obtained. In most cases, a volar release is all that is required. If marked contracture still exists, however, a dorsal capsular release can be performed.

Dorsal Capsular Release

In our opinion, the dorsal capsular release is more technically difficult than the volar release because of the proximity of the extensor tendons. The extensor tendons lie directly adjacent to the dorsal capsule so that there is no safety margin between the capsule to be released and the tendon to be preserved. In contrast to the volar release, in which there is a distinct layer of periarticular fat that acts as a buffer for the volar neurovascular structures, no such protection exists for the extensor tendons.

Our preferred technique for dorsal capsular release is to use a volar radial portal as a viewing portal as described by Slutsky, Ashwood, and Abe and their colleagues,¹¹^–¹³ and the 3,4 dorsal portal as a working portal. Blunt dissection using a hemostat is used to pass a nylon tape through the 3,4 portal, down to the level of the tendon-capsule interface and across to the 6R portal. By applying tension to the nylon tape, it can be used as a retractor to protect the tendons from injury during release of the dorsal capsule. The nylon tape is positioned between the capsule and extensor tendons.

The capsule is excised using basket forceps with one jaw visualized intra-articularly and the other jaw placed between the capsule and the nylon tape retracting the tendons as shown in Figure 52-3. The capsulectomy proceeds from the 3,4 portal, ulnarly to the point of the 6R portal. The use of the basket forceps to release the dorsal capsule down to the level of the tendon-capsule interface, at which the retracting nylon tape is seen.

FIGURE 52-3 Video frame showing the use of the basket forceps to divide the dorsal capsule. Note the nylon tape seen immediately adjacent to the forceps and the vertically oriented extensor tendons just past the nylon tape.

Figure 52-4 shows a summary of the ligaments to be divided during either a volar or a dorsal procedure. Following either procedure, a gentle closed manipulation is performed.