Dy, Christopher J. MD, MSPH*; Ouellette, Elizabeth Anne MD, MBA†; Makowski, Anna-Lena HTL†
Instability of the distal radioulnar joint (DRUJ) presents both a diagnostic and therapeutic challenge to the physician. The biomechanical complexities of the joint greatly contribute to the difficulty in managing the common complaint of wrist pain because the incongruity of the DRUJ predisposes the articulation to instability even in the presence of ligamentous support.1 Stability of the radioulnocarpal unit is mainly influenced by the triangular fibrocartilage complex (TFCC), which provides biomechanical support in 2 orientations: radioulnar and ulnocarpal. The TFCC provides a continuous gliding surface spanning the distal surfaces of the radius and ulna to allow for carpal movements and also acts as a dynamic stabilizer of the forearm during pronation and supination.2 In addition to its radioulnar function, the TFCC stabilizes the ulnar side of the carpus and aids in load transference from the ulnar carpus to the ulna.1 Instability of the DRUJ may result from a number of etiologies, including trauma and degenerative change, and commonly involves pathology of the TFCC. Damage to the TFCC is reflected as a disruption of its normal function, and its clinical presentation is characterized by difficulty with carpal movements, pronation, and supination, with all possibly warranting surgical repair. Although asymptomatic ulnocarpal instability is present in nearly two thirds of patients,3 operative indication is when symptoms such as ulnar-sided pain, weakness, and supination deformity are present. Restoration of the structural support provided by the TFCC is imperative to relieve symptoms and to improve the biomechanical environment of the joint.
Reconstruction of the DRUJ is indicated in acute injury in which damage to the TFCC is beyond repair and in chronic instability of the DRUJ. Ideally, reconstructive approaches should fulfill the anatomic and functional roles of the intact TFCC. Numerous soft tissue operations targeted toward reconstruction of the DRUJ ligaments have been described with variable levels of biomechanical and clinical success. Previously published reconstructive techniques can be broadly grouped into 3 categories4: extrinsic radioulnar tethering, such as the Fulkerson-Watson technique5; the creation of an indirect radioulnar link using an ulnocarpal sling or tenodesis, such as those described by Breen and Jupiter,6 Hui and Linscheid,7 and Tsai and Stillwell8; and radioulnar ligament reconstruction, such as those described by Bowers,9 Johnston and Sanders,10 Scheker et al,11 and most recently by Adams.4 Previous biomechanical comparison has shown that extrinsic radioulnar tethering and indirect radioulnar linking seem to be insufficient in addressing the full scope of TFCC function.12 Although the merits of anatomic radioulnar ligament reconstruction have been shown biomechanically and clinically, there remains room for improvement in repairing the unstable DRUJ. Recent biomechanical research has demonstrated that a repair of the DRUJ capsule results in better restoration of intact wrist kinematics than radioulnar ligament reconstruction,13 providing an opportunity to consider the importance of extrinsic soft tissue stabilization.
One approach to using extrinsic soft tissue stabilization has been introduced by the senior author (E.A.O.). In this repair, which was originally described by Stanley and Herbert14 to restore DRUJ stability after ulnar head prosthesis insertion, an extensor retinaculum capsulorrhaphy is used to stabilize the DRUJ in both radioulnar and ulnocarpal orientations. This procedure, referred to hereafter as the Herbert sling, implements the use of an ulnar-based flap of the extensor retinaculum and has resulted in clinical success and restoration of stability on biomechanical testing (C.J.D. et al, unpublished data, 2008). The radioulnar and ulnocarpal functions of the TFCC are emulated by the Herbert sling, as the ulnar carpus is stabilized in volar translation and a radioulnar link is created to guide the forearm through its axis of rotation. A strong soft tissue tether is maintained among the distal radius, distal ulna, and ulnar carpus; this biarthrodial link is reinforced by ligamentotaxis created by the soft tissue fiber orientation.15 Our biomechanical study has shown an increase in ulnocarpal and in radioulnar stability (C.J.D. et al, unpublished data, 2008) using the Herbert sling. Additionally, our initial clinical experience has been very promising with this technique, with good to excellent outcomes shown in a small series of 14 patients after long-term follow-up (C.J.D. et al, unpublished data, 2008). The Herbert sling is a highly effective and technically simple procedure, which is particularly useful for patients who have symptomatic instability of both the DRUJ and ulnocarpal articulation.
History and Physical Examination
In both acute and chronic cases, the clinical presentation of the ulnocarpal instability consists of ulnar-sided wrist pain with or without clicking, especially with forearm pronation-supination activities, such as putting topspin on a tennis ball with a forehand shot. There may be laxity during supination and weakness in passive or active pronation-supination movements. These symptoms may hinder range of motion and function of the wrist.
On physical examination, patients often have tenderness upon palpation of the ulnar carpus. In the absence of concomitant pathology, provocative maneuvers such as Watson and Shuck tests are negative. Midcarpal instability can also be ruled out with a negative wrist-pivot shift test, as first described by Lichtman et al.16 To perform this maneuver, position the wrist in a 15-degree ulnar deviation. The examiner grabs the patient's hand and exerts palmar pressure on the distal capitate with the hand pronated and the forearm stabilized. The wrist is axially loaded and ulnarly deviated, then repeated with the wrist in radial deviation. A characteristic clunk, with or without pain, can be solicited and is indicative of midcarpal instability. In patients with ulnocarpal instability, the wrist assumes an ulnar-sided supination deformity similar to that seen in rheumatoid arthritis.
A key to diagnosing ulnocarpal instability is the supination test, which is a diagnostic maneuver developed by the senior author (E.A.O.). This examination is performed by stabilizing the affected DRUJ with a firm grasp while stressing the wrist in supination and volar translation. When the wrist is loaded axially and returned to neutral in ulnar deviation, the patient's pain is reproduced. The wrist may also clunk back into reduction. The contralateral wrist is also tested for comparison.
Standard posteroanterior and lateral radiographs of the wrist have poor diagnostic value with respect to ulnocarpal joint instabilities but are useful to assess the scapholunate and lunotriquetral articulations. Computed tomography is useful for visualizing joint congruity and fractures. Dynamic real-time fluoroscopy during the supination test allows the examiner to evaluate and visualize the presence and amount of ulnocarpal joint instability. The changing appearance of the triquetrium, demonstrated by its decreased length, while in a position of supination indicates ulnocarpal instability.17 The pisiform's location in relation to the triquetrium may also indicate the type of ligamentous tear or laxity by either moving together with the triquetrium during the supination test or appearing to be stationary as the triquetrium is moving (Harrison et al, unpublished data, 2004).
Triple injection arthrography of the midcarpal, radiocarpal, and DRUJs can be useful in showing scapholunate interosseous ligament or lunotriquetal interosseous ligament tears, TFCC tears, and ulnar-sided TFCC tears, respectively. The findings must correlate with symptoms for accurate diagnosis.18,19 Standard magnetic resonance imaging effectively demonstrates the normal anatomy of TFCC and the intrinsic and extrinsic ligaments of the wrist. Abnormalities of these structures can be detected with experience, but the radiographic literature has reported shortcomings of standard magnetic resonance imaging in diagnosing peripheral TFCC tears. Magnetic resonance arthrography, with injection of contrast into the DRUJ, is an adequate way of diagnosing peripheral TFCC tears with a sensitivity of 85% and specificity of 76% when compared with wrist arthroscopy.20
Wrist arthroscopy is widely considered as the criterion standard with respect to diagnostic evaluation of the radiocarpal and midcarpal articulations. Arthoscopic visualization allows for the determination of the size, location, and extent of ligamentous injuries of the wrist. Comparison of arthroscopy with arthrography by Cooney21 revealed arthroscopy to be the superior method of diagnosing injuries of the TFCC and interosseous ligaments.
Conservative treatment includes the use of a removable soft leather wrist splint that minimizes motion of the wrist, such as those originally designed for use by gymnasts. If the patient wishes to return to athletic activities, it is advised that he or she proceeds with cautious limitation while wearing the splint. Although the splint allows for motion of the wrist and for the use of athletic tools, it is imperative to reduce the intensity of activity to a tolerable level. When activity levels are limited or more support is needed, such as while sleeping, a static splint is advised.
Physical or occupational therapy to increase wrist and forearm range of motion and to strengthen the muscles spanning the ulnocarpal and DRUJs may be beneficiary. Nonsteroidal anti-inflammatory drugs are also recommended before deciding on surgery with an initial trial of 4 to 6 weeks.
Aside from associated DRUJ and ulnocarpal instability, a painful ulnocarpal joint with diminished grip and/or pronosupination strength that does not respond to conservative treatment is another main indication for surgery. Individuals with high demand on strong wrist function in weight-bearing supination (golfers, tennis players, certain skilled labor professions) may be considered for surgery without conservative treatment initially.
The Herbert sling procedure consists of the development of an ulnar-based flap of the extensor retinaculum, advanced at a 30- to 40-degree angle from distal ulnar to proximal radial by securing into the distal radial periosteum at which the retinaculum attaches. This reduces the radioulnar joint and the carpus to the ulna with a single advancement of the extensor retinaculum.
Preoperative planning begins with a review of all imaging studies to determine any concomitant pathology of the wrist joint. Arthroscopic examination of the wrist is generally undertaken immediately before ulnocarpal reconstruction to address any concomitant lesions and/or synovitis within the wrist. Diagnostic physical examination maneuvers are repeated while the patient is under anesthesia. These maneuvers include the piano key test and ulnocarpal supination test as described earlier.
The patient is positioned with the forearm in pronation and the elbow flexed at 45 degrees. In general, a regional block of the upper extremity distal to the elbow is used. The dorsal aspect of the wrist joint is prepared in a sterile manner. Exposure of the dorsal surface of the wrist joint is the only surgical approach needed.
A longitudinal incision is created over the fifth extensor compartment at the level of the wrist. The extensor retinaculum is incised between the fourth and fifth compartments taking care not to enter the fourth compartment (Fig. 1). An ulnar flap of the distal two thirds of the retinaculum is then raised. The extensor digiti quinti (EDQ) is prepared for transposition from dorsal to the retinaculum flap (Fig. 2).
The wrist is placed in neutral, and a downward force is applied on the ulna to reduce the DRUJ. The retinacular flap is transposed proximally and sutured to the periosteum of the ulnar border of the distal radius using 2-0 PDS absorbable sutures. Suture anchors can be used if the soft tissue is deficient. The extensor retinaculum is carefully imbricated in an oblique fashion (30-40 degrees) from distal-ulnar to radial-proximal (Fig. 3). The EDQ is then relocated dorsally of the imbricated extensor-retinaculum flap (Figs. 4 and 5).
The Herbert sling repair can loosen if aggressive strengthening is undertaken too quickly; gentle active rotatory motion should only be introduced after an extended period of immobilization as detailed below. Additionally, if imbrication of the extensor retinaculum is not performed in an oblique direction, the ulnocarpal effect of the sling is lost, and a supination deformity of the wrist may occur or reoccur. If imbrication occurs at 90 degrees perpendicular to the DRUJ, only the radioulnar aspect of the joint will be stabilized and the ulnocarpal aspect will remain unstable.
Wrist pain and dysesthesias may occur secondary to irritation or injury of the dorsal branch of the ulnar nerve. Care must be taken when placing sutures for imbrication of the extensor retinaculum to avoid injury to surrounding tissues or nerve structures. Addtionally, manipulation of the EDQ tendon during the procedure may result in a temporary EDQ tendonitis that usually resolves 6 months after the operation.
Initial postoperative care consists of 6 weeks in a thumb spica Muenster-type cast with the forearm and wrist both positioned in neutral followed by 6 weeks in a removable wrist-based thumb spica splint. A silastic sheet can be applied in the immediate postoperative period over the surgical incision to aid scar remodeling. Scar massage is initiated after the cast has been discontinued.
Gentle active forearm pronation and supination during temporary splint removal is introduced at 6 weeks postoperatively at the patient's discretion. Passive motion with a physical or occupational therapist is not necessary at this point. No heavy lifting or aggressive motion is permitted until 3 months postoperatively. Vigorous strengthening exercises to regain pronation are begun 3 months after the operation with a physical or occupational therapist at a pace that the patient is comfortable, with exercise intensity increased gradually. Pronation and supination stretch can be achieved by holding a hammer or frying pan as a weight during the motions, whereas wrist flexion and extension stretch can be achieved by gradually increasing the weight tolerated when holding a bucket of water over a table edge.
If the patient's preoperative activities included sports such as golf and tennis, these activities should be gradually incorporated into the strenthening program 3 months after surgery. A warm, moist wrap can be used around the wrist to provide additional stretching of the wrist before the activities. Additionally, ice and nonsteroidal anti-inflammatory agents can be used to provide relief after each session.
1. Stuart P, Berger R, Linscheid R, et al. The dorsopalmar stability of the distal radioulnar joint. J Hand Surg [Am]. 2000;25:689-699.
2. Palmer AK, Werner FW. The triangular fibrocartilage complex of the wrist-anatomy and function. J Hand Surg [Am]. 1981;6:153-162.
3. Ouellette A, Harrison R, Latta L, et al. Ulnocarpal wrist instability: Evaluating a diagnostic and surgical method. Poster session. 10th Congress of the Federation of the European Societies for Surgery of the Hand-FESSH, Gothenburg, Sweden. June 15-18, 2005.
4. Adams BD. Anatomic reconstruction of the distal radioulnar ligaments for DRUJ instability. Tech Hand Up Extrem Surg. 2000;4:154-160.
5. Fulkerson JP, Watson HK. Congenital anterior subluxation of the distal ulna. A case report. Clin Orthop Relat Res. 1978;131:179-182.
6. Breen TF, Jupiter JB. Extensor carpi ulnaris and flexor carpi ulnaris tenodesis of the unstable distal ulna. J Hand Surg [Am]. 1989;14:612-617.
7. Hui FC, Linscheid RL. Ulnotriquetral augmentation tenodesis: a reconstructive procedure for dorsal subluxation of the distal radioulnar joint. J Hand Surg [Am]. 1982;7:230-236.
8. Tsai TM, Stillwell JH. Repair of chronic subluxation of the distal radioulnar joint (ulna dorsal) using flexor carpi ulnaris tendon. J Hand Surg [Br]. 1984;9:289-293.
9. Bowers WH. Instability of the distal radioulnar articulation. Hand Clin. 1991;7:311-327.
10. Johnston J, Sanders WE. Posttraumatic radioulnar instability: treatment by anatomic reconstruction of the volar and dorsal radioulnar ligaments. Orthop Trans. 1995;19:832.
11. Scheker LR, Belliappa PP, Acosta R, et al. Reconstruction of the dorsal ligament of the triangular fibrocartilage complex. J Hand Surg [Br]. 1994;19:310-318.
12. Petersen MS, Adams BD. Biomechanical evaluation of distal radioulnar reconstructions. J Hand Surg [Am]. 1993;18:328-334.
13. Gofton WT, Gordon KD, Dunning CE, et al. Comparison of distal radioulnar joint reconstructions using an active joint simulator. J Hand Surg [Am]. 2005;30:733-742.
14. Stanley D, Herbert TJ. The Swanson ulnar head prosthesis for post-traumatic disorders of the distal radio-ulnar joint. J Hand Surg [Br]. 1991;17:682-688.
15. Kleinman WB, Graham TJ. The distal radioulnar joint capsule: clinical anatomy and role in posttraumatic limitation of forearm rotation. J Hand Surg [Am]. 1998;23:588-599.
16. Lichtman DM, Bruckner JD, Culp RW, et al. Palmar midcarpal instability: results of surgical reconstruction. J Hand Surg [Am]. 1993;18:307-315.
17. Ouellette EA, Harisson RJ, Latta LL, et al. The Biomechanics of Diagnosing and Treating Peripheral Triangular Fibrocartilage Complex Instability. Poster session. The American Orthopaedic Association, Boston, Mass. June 23rd-26th, 2004.
18. Levinsohn EM, Rosen DI, Palmer AK. Wrist arthography: value of the three-compartment injection method. Radiology. 1991;179:231-239.
19. Weiss AP, Akelman E, Lambiase R. Comparison of the findings of triple-injection cinearthrography of the wrist with those of arthroscopy. J Bone Joint Surg Am. 1996;78:348-356.
20. Ruegger C, Schmidt MR, Pfirrmann CW, et al. Peripheral tear of the triangular fibrocartilage: depiction with MR arthrography of the distal radioulnar joint. Am J Roentgenol. 2007;188:187-192.
21. Cooney WP. Evaluation of wrist pain by arthrogram, arthroscopy, and arthrotomy. J Hand Surg [Am]. 1993;18:815-822.
distal radioulnar joint; ulnocarpal joint; capsulorrhaphy
© 2009 Lippincott Williams & Wilkins, Inc.