Clinical Relevance

Elsaidi and colleagues¹⁴ showed the importance of the DRCL on scaphoid kinematics through a series of sectioning studies. They sequentially divided the radioscaphocapitate, long radiolunate, radioscapholunate, and short radiolunate ligaments. They next divided the central and proximal scapholunate interosseous ligament (SLIL), then the dorsal SLIL, and finally the dorsal capsule insertion on the scaphoid. There was no appreciable change in the radiographic appearance of this wrist. When the DRCL was divided, a dorsal intercalated segmental instability deformity occurred.

In another series of biomechanical studies on ligament sectioning using 24 cadaver arms, Short and coworkers¹⁵ determined that the SLIL is the primary stabilizer of the scapholunate articulation, and that the DRCL, the dorsal intercarpal ligament, the scaphotrapezial ligament, and the radioscaphocapitate ligament are secondary stabilizers. They found that dividing the dorsal intercarpal or scaphotrapezial ligament alone followed by 1000 cycles of wrist flexion-extension and radial-ulnar deviation had no effect on scaphoid and lunate kinematics. Dividing the DRCL alone did cause increased lunate radial deviation when the wrist was in maximum flexion. Dividing the SLIL after any of the ligaments tested produced increased scaphoid flexion and ulnar deviation while the lunate extended. Short and coworkers¹⁵ also hypothesized that cyclic motion seems to cause further deterioration in carpal kinematics owing to plastic deformation in the remaining structures that stabilize the scapholunate.

These data provide a rationale for repairing the DRCL. The data also suggest that consideration should be given to augmenting the stability of the scaphotrapezial ligaments concomitant with treatment of the SLIL instability. Similar studies have established that the triangular fibrocartilage complex (TFCC) and the dorsal and volar radioulnar ligaments are primary stabilizers of the ulnocarpal joint.¹⁶ DRCL tears that are found during the arthroscopic treatment of ulnar-sided lesions are handled in a similar fashion.

Indications

Geissler and colleagues¹⁷ proposed an arthroscopic grading scale of interosseous ligament instability that has gained wide acceptance. In Geissler grade 1 and 2 lesions, there is no to minimal instability owing to ligament attenuation, but no tearing; these are synonymous with a dynamic instability. Grade 3 and 4 lesions represent partial and complete tears with greater degrees of carpal instability. This classification quantifies the resultant instability, and not the actual size of the tear. Based on this grading scale, an arthroscopic classification of DRCL tears is proposed in Table 51-1.

TABLE 51-1 Classification of Dorsal Radiocarpal Ligament Tears*

DRCL, dorsal radiocarpal ligament; LTIL, lunotriquetral interosseous ligament; SLIL, scapholunate interosseous ligament; TFCC, triangular fibrocartilage complex.

* The ligament with the highest Geissler grade determines the stage.

The treatment of DRCL tears is summarized in Table 51-2. An arthroscopic repair is indicated for isolated DRCL tears, which often leads to resolution of the wrist pain.^8,10 DRCL tears are commonly associated with SLIL tears or instability or both. Geissler grade 1 and 2 SLIL injuries are still amenable to arthroscopic treatment. In these situations, an arthroscopic repair of any associated DRCL tears is indicated because it may augment the coronal stability of the SLIL repair.^8–10 In open SLIL repairs, sagittal plane stability is often supplemented by adding a dorsal capsulodesis or using a tendon weave, such as the modified Brunelli procedure. Arthroscopic thermal shrinkage of the scaphotrapezial ligaments also theoretically may enhance the sagittal plane stability of the scapholunate joint. This is currently under investigation, but no data are available to recommend this procedure as yet.

TABLE 51-2 Treatment of Dorsal Radiocarpal Ligament Tears

DRCL, dorsal radiocarpal ligament; LTIL, lunotriquetral interosseous ligament; PRC, proximal row carpectomy; SLIL, scapholunate interosseous ligament; TFCC, triangular fibrocartilage complex.

Geissler grade 3 SLIL injuries represent a relative gray area for arthroscopic treatment methods alone. Investigators have shown, however, that this type of ligament injury can be treated successfully with thermal shrinkage and pinning. In the author’s view, any associated DRCL tears should be repaired arthroscopically at the same time. Tears or instability of the lunotriquetral interosseous ligament are treated in similar fashion to the SLIL. DRCL repairs are indicated for Geissler grade 1 and 2 lunotriquetral interosseous ligament injuries and can be combined with lunotriquetral interosseous ligament shrinkage and débridement with or without pinning. Because there is a marked association of DRCL tears in the presence of long-standing TFCC tears, in my view DRCL repairs should be performed concomitantly with débridement or repair of the TFCC tear.

Contraindications

In cases in which the treatment of an SLIL tear or dynamic scapholunate instability includes some type of dorsal capsulodesis, the dorsal incision followed by the creation of a dorsal capsular checkrein to restrain palmar flexion of the scaphoid renders any separate treatment of the DRCL tear unfeasible. When the DRCL tear is seen in association with palmar midcarpal instability, a soft tissue repair of the dorsal ligaments would not by itself correct the midcarpal instability.¹⁸ The results of a DRCL repair in association with two or more other intracarpal lesions are often inconsistent, and open repair methods should be considered, especially if they include a Geissler grade 3 ligament injury.⁹ Geissler grade 4 ligament injuries are beyond the realm of arthroscopic treatment and require open repair or reconstruction (see Table 51-2).

Equipment and Implants

Generally, a 2.7-mm, 30-degree angled arthroscope with a camera attachment is necessary. A fiberoptic light source, video monitor, and printer also are standard equipment. Newer digital systems provide superior video quality compared with analog cameras and allow direct writing to a CD. A 3-mm hook probe is needed for palpation of intracarpal structures. Some method of overhead traction is useful. This may include traction from the overhead lights or a shoulder holder along with 5- to 10-lb sandbags attached to an arm sling. A traction tower, such as the Linvatec tower (Conmed-Linvatec Corp, Largo, FL) or the ARC wrist traction tower (Arc Surgical LLC, Hillsboro, OR), greatly facilitates instrumentation. A motorized shaver and suction punch forceps are useful for débridement. Some type of diathermy unit, such as the Oratec radiofrequency probe (Smith & Nephew, New York, NY), is needed in cases where augmentation of the repair with capsular shrinkage is desired. Various curved and straight 18-gauge spinal needles are used for passage of an absorbable 2-0 suture for the outside-in repair. A suture lasso or grasper is needed to retrieve the suture ends.

Surgical Technique (Video)

An inside-out arthroscopic repair technique of the DRCL was performed earlier An outside-in repair is technically easier and has been used more recently. The VR portal is established by making a 2-cm longitudinal incision in the proximal wrist crease, exposing the flexor carpi radialis tendon sheath. The sheath is divided, and the flexor carpi radialis tendon is retracted ulnarly. The radiocarpal joint space is identified with a 22-gauge needle, and the joint is inflated with saline. A blunt trochar and cannula are introduced through the floor of the flexor carpi radialis sheath, which overlies the interligamentous sulcus between the radioscaphocapitate ligament and the long radiolunate ligament.

A 2.7-mm, 30-degree arthroscope is inserted through the cannula. The repair is performed by spearing the radial side of the DRCL tear with a curved 21-gauge spinal needle placed through the 3,4 portal while viewing through the arthroscope in the VR portal. A 2-0 absorbable suture is threaded through the spinal needle and retrieved with a grasper or suture snare inserted through the 4,5 portal (Fig. 51-1A-F). A curved hemostat is used to pull either end of the suture underneath the extensor tendons, and the knot is tied either at the 3,4 portal or at the 4,5 portal. The repair is augmented with thermal shrinkage if the torn edge of the DRCL is voluminous and still protrudes into the joint after the sutures are tied (Fig. 51-1H).

FIGURE 51-1 Outside-in dorsal radiocarpal ligament (DRCL) repair technique. A, Arthroscopic view of DRCL tear from the VR portal. B, Drawing of DRCL tear. C, Insertion of curved spinal needle through edge of DRCL tear. D, Drawing of outside-in technique using two spinal needles and a suture retriever. E, Insertion of second spinal needle. F, Arthroscopic view of suture loop before tying. G, Drawing of completed repair. H, Repair augmented with thermal shrinkage after suture has been tied.

(A, C, E, F, and H from Slutsky DJ: Clinical applications of volar portals in wrist arthroscopy. Tech Hand Upper Extrem Surg. 2004; 8:229-238; B, D, and G from Slutsky DJ: Arthroscopic repair of dorsal radiocarpal ligament tears. J Arthrosc Related Surg. 2005; 21:1486e1-1486e8.)

Rehabilitation

After the repair, the patient is placed in a below-elbow splint with the wrist in neutral rotation. Finger motion and edema control are instituted immediately. At the first postoperative visit, the sutures are removed, and the patient is placed in a below-elbow cast for 6 weeks, followed by wrist mobilization.

Clinical Studies

A retrospective chart review of 21 patients who underwent a DRCL repair was published in 2005. None of the wrists showed a static carpal instability pattern on x-ray. Preoperative magnetic resonance imaging (MRI) was performed by the referring physician in six patients. Preoperative arthrograms were performed as a part of the diagnostic workup for wrist pain in 20 patients. None of the DRCL tears in this series were identified with preoperative arthrography or MRI. Preoperative MRI in one patient with a DRCL tear was misinterpreted as representing a dorsal wrist ganglion. There were 6 men and 16 women. The average patient age was 40 years (range 25 to 62 years). All patients failed a trial of conservative treatment with wrist immobilization, cortisone injections, and work restrictions. The average length of conservative treatment was 7 months. The time interval between injury and surgical intervention averaged 25 months (range 8 to 53 months).

At the time of arthroscopy, four patients were found to have an isolated DRCL tear that was solely responsible for their wrist pain. The remaining 17 patients had additional ligamentous pathology. A dorsal capsulodesis was done in seven patients as the primary treatment for the SLIL instability or tear. Thirteen of the 21 patients underwent an arthroscopic DRCL ligament repair with or without thermal shrinkage as described earlier (repair in 5, repair + shrinkage in 6, shrinkage in 2). Ten of these patients underwent ancillary procedures for treatment of the coexisting wrist pathology. Lunotriquetral ligament tears were treated with débridement with or without pinning. Triangular fibrocartilage tears were débrided or repaired. Scapholunate ligament tears or instability were treated with capsulodesis with or without open repair. One patient had generalized arthrofibrosis, which precluded a DRCL repair. Concomitant nerve entrapment was a common finding, which was treated at the same time.

The average duration of follow-up was 16 months (range 7 to 41 months); one patient was lost to follow-up at 4 weeks. Pain was graded as none, mild, moderate, and severe. Wrist extension, wrist flexion, radial deviation, ulnar deviation, and grip strength were assessed. Wrist range of motion was compared with presurgical values. Grip strength was compared with the contralateral side at follow-up evaluation.

The four patients who underwent an isolated DRCL repair were satisfied with the outcome of surgery and would repeat the surgery again because it improved their symptoms. All four patients graded their pain as none or mild. None of these patients were taking pain medications. All returned to their previous occupations without restriction. Their wrist motion was unchanged compared with the preoperative status. Grip strengths were 90% to 130% of the opposite side.

A dorsal capsulodesis was performed as the primary treatment for an SLIL tear or a dynamic scapholunate instability in seven patients instead of a DRCL repair. The capsulodesis was ineffective in controlling pain in the remaining four patients, three of whom had additional wrist pathology. This is consistent with other studies, which have shown that although pain is improved, it does not resolve completely after a dorsal capsulodesis in most cases.¹⁹ Cadaver studies suggest that dynamic scaphoid instability results from an isolated injury to the SLIL without damage to the dorsal intercarpal and DRCL ligaments.⁴ I found the corollary to hold true in that four of seven patients with dynamic scapholunate instability had a DRCL tear, but an intact scapholunate ligament.

The remaining 10 patients had a DRCL tear in combination with ulnar-sided pathology. One patient was lost to follow-up. Of the nine patients, six had chronic residual pain, with three of these patients having arthroscopic evidence of osteoarthritis. Soft tissue procedures alone were ineffective in controlling their symptoms. There was a trend toward a worse outcome when there was coexisting ulnar-sided carpal pathology, which may reflect more severe or longer standing carpal instability. This trend was not invariable, however, because two of nine patients in this group had only occasional, mild pain after treatment. The final patient in this subgroup had an associated palmar midcarpal instability with laxity of the lunotriquetral joint. Although a DRCL repair and lunotriquetral joint pinning improved his symptoms, it did not correct the midcarpal instability, which remained mildly symptomatic.

Current Experience

Sixty-four patients have now undergone arthroscopy for the investigation and treatment of refractory wrist pain. Thirty-five patients were found to have DRCL tears, for an overall incidence of 55%. Five patients had an isolated DRCL tear. Thirteen patients in this series had an SLIL instability or tear or both; 7 of 13 (54%) also had a DRCL tear. Of this subgroup, four patients had a Geissler grade 1 or 2 instability, and three had a Geissler grade 3 or 4 tear. Seven patients had a lunotriquetral interosseous ligament instability or tear or both; two of seven (28%) also had a DRCL tear. Of this subgroup, one patient had a Geissler grade 2 instability, and one had a Geissler grade 3 or 4 tear. Two patients had a capitohamate ligament tear; one of these patients also had a DRCL tear. Seven patients had a solitary TFCC tear; six of seven (86%) were in association with a DRCL tear. One patient had a chronic ulnar styloid nonunion and a DRCL tear. There was TFCC fraying, but no tear or detachment. Two or more lesions were present in 23 patients; DRCL tears were present in 12 patients (52%). Sixty-two percent of the combined lesions that were associated with a DRCL tear also included a TFCC tear.

Summary

DRCL tears are found in approximately 50% of cases when there is a chronic intracarpal derangement. It is prudent that the arthroscopist is diligent in recognizing and treating this condition. Ongoing research into the ideal method of treatment of these combined injuries is still needed.