Operative Techniques in Orthopaedic Surgery (4 Volume Set) 1st Edition

284. Open Scapholunate Ligament Repair and Augmentation

Alex M. Meyers, Alexander H. Payatakes, and Dean G. Sotereanos

DEFINITION

images Scapholunate instability is the most common form of carpal instability.

images Scapholunate interosseous ligament (SLIL) injury can result in a predictable pattern of arthritis over time: scapholunate advanced collapse (SLAC).12

images Acute tears (<6 weeks from injury) versus chronic tears (>6 weeks from injury)

images Acute tears tend to be amenable to primary ligament repair.

images Chronic tears tend to require ligament reconstruction procedures.

images Static or dynamic instability

images Static instability: any or all of the five characteristic changes on standard plain radiographs (see below)

images Dynamic instability: normal plain radiographs; however, with loaded (grip view) plain radiographs, any or all of the five characteristic changes may become present.10

images Fixed versus reducible deformity

images Fixed deformity: the static radiographic changes are not passively correctible

images Reducible deformity: the static radiographic changes are passively correctible

images This distinction can be determined preoperatively by noting improvement in the static changes on plain radiographs of the wrist in radial deviation compared with AP views of the wrist.

ANATOMY, PATHOGENESIS, AND NATURAL HISTORY

images See Chapter HA-41.

PATIENT HISTORY AND PHYSICAL FINDINGS

images Typical presentation follows a fall on an outstretched hand with acute onset of wrist pain and mild dorsal wrist swelling.

images Key physical examination findings are reviewed in Chapter HA-41.

IMAGING AND OTHER DIAGNOSTIC STUDIES

images Plain radiographs may reveal five characteristic findings suggestive of SLIL pathology (FIG 1).

images Terry Thomas sign: gap between the scaphoid and lunate of more than 3 mm on posteroanterior (PA) radiograph

images Cortical ring sign: Cortical hyperdensity is seen on PA radiograph as the scaphoid moves into increasing flexion.1

images Angular changes in the carpal rows

images Scapholunate angle: Normal is 30 to 60 degrees (mean 46 degrees); with SLIL injury, more than 60 degrees6

images Capitolunate angle: Normal is −15 to 15 degrees (mean 0 degrees); with SLIL injury, more than 15 degrees

images Radiolunate angle: Normal is −10 to 10 degrees (mean 0 degrees); with SLIL injury, more than 10 degrees

images Quadrangular lunate: As the lunate moves into extension it assumes a rectangular appearance on PA radiograph.

images Disruption of Gilula’s lines: Gentle concentric arcs follow the proximal and midcarpal rows. These lines are disrupted with SLIL tears as the relationship of the proximal row is lost.

images Arthrography: sensitivity 56%, specificity 83%, accuracy 60%13

images False-positive results have been documented with communication of contrast shown in asymptomatic patients.1

images CT arthrography: sensitivity 86% to 100% (100% sensitive in the detection of dorsal ligament tears), specificity 50% to 79% (79% specific in the detection of dorsal ligament tears), accuracy 78% to 83%7

images MRI: sensitivity 25% to 60%, specificity 77% to 100%, accuracy 64% to 78%8

images Specifically, palmar tears of the SLIL were identified with a sensitivity of 60% and specificity of 77% in a cadaveric study. However, the more important stabilizing dorsal portion tears were seen in 0 of 9 specimens.7

images Ultrasound: sensitivity 46%, specificity 100%, accuracy 89%2

images A negative result with various imaging studies does not prove an absence of ligamentous injury. Arthroscopy has become the gold standard for the diagnosis of SLIL tears.

DIFFERENTIAL DIAGNOSIS

images Dynamic SLIL instability or partial SLIL tear

images Radiocarpal arthritis

images Scaphoid fracture

images Keinböck or Preiser disease

images

FIG 1 • AP and lateral plain radiographs of a patient with scapholunate ligament tear.

NONOPERATIVE MANAGEMENT

images Nonoperative methods are unsuccessful in treating dynamic or static acute scapholunate ligament injuries.

images 0 of 19 patients with dynamic instability treated with immobilization, nonsteroidal anti-inflammatories, and activity modification had substantial reduction in symptoms even up to 12 weeks into treatment.14

SURGICAL MANAGEMENT

images Indications

images Wrist pain with an acute tear (<6 weeks)

images These patients may or may not have static radiographic changes.

images Should static radiographic changes be present, plain radiographs in radial deviation can show if the radiographic changes are fixed (and therefore are not amenable to soft tissue repairs) or correct in radial deviation (and therefore are amenable to soft tissue repairs).

images Wrist pain with dynamic instability

images We advocate diagnostic arthroscopy before open treatment.

Preoperative Planning

images General or regional anesthesia

images Equipment

images Mini suture anchors (1.8 mm)

images Kirschner wire driver and smooth wires (0.045 and 0.062 inch)

images Arthroscopic equipment (see Chap. HA-41)

images Mini C-arm

Positioning

images The patient is positioned supine with a hand table.

images The bed is turned such that the hand table faces the corner opposite anesthesia.

images Fluoroscopy can then move in and out from the opposite corner perpendicular to the patient.

images An upper arm nonsterile tourniquet should be placed.

images The operative arm is prepared and draped. Slack is left in the armboard portion of the drape to allow the sterile wrist traction tower to slide under the arm above the elbow.

images The operative wrist is suspended in a wrist traction tower.

Approach

images A preoperative examination of both wrists is performed and documented, noting passive range of motion, swelling, and the Watson scaphoid shift test.

images Arthroscopy is recommended before open reconstruction because of the lack of diagnostic accuracy of available imaging modalities.

images Wrist arthroscopy is considered the gold standard for diagnosis of SLIL pathology and can confirm the diagnosis and degree of instability before making a larger skin incision.

images Geissler staging of SLIL tears3 is covered in Chapter HA-41.

TECHNIQUES

DIAGNOSTIC WRIST ARTHROSCOPY

images  See Chapter HA-41.

images  The 3–4 portal is used for viewing.

images  The 6U portal is used for outflow (typically an 18-gauge needle with sterile IV tubing).

images  The 4–5 is used for placement of instruments.

images  The SLIL is probed in the radiocarpal and midcarpal joints.

images A 1-mm arthroscopic probe passable in the scapholunate interval and rotated 360 degrees is indicative of a grade III Geissler lesion.

images A “drive-through” sign with a 2.7-mm arthroscope is indicative of a grade IV Geissler lesion.

images Midcarpal arthroscopy most effectively reveals the degree of instability.

DIRECT SLIL REPAIR

images  Specific indications for direct SLIL repair with or without dorsal capsulodesis

images Geissler III or IV complete SLIL tear

images Injury less than 6 weeks old

images   It is rare that a repairable ligament is available more than 3 months after injury.

images Minimal degenerative changes in the radiocarpal and midcarpal joints

images Static radiographic changes that are not fixed

images Adequate SLIL tissue

images  Make a standard longitudinal dorsal incision just ulnar to the tubercle of Lister and dissect to the extensor retinaculum.

images  Raise flaps at the level of the extensor retinaculum, exposing the retinacular edges proximally and distally.

images Superficial radial and ulnar dorsal cutaneous nerve branches will be within these flaps.

images  Incise the extensor retinaculum over the third extensor compartment and transpose the extensor pollicis longus (EPL) tendon into the radial subcutaneous space.

images  Expose the dorsal capsule and dorsal extrinsic radiocarpal ligaments (dorsal radiocarpal [DRC] and dorsal intercarpal [DIC] ligaments).

images  Incise the dorsal capsule, leaving a 1to 1.5-cm ulnarbased flap (TECH FIG 1A).

images Leaving the capsule attached ulnarly provides a capsular flap available for capsulodesis or augmentation of a repair if desired.

images This flap of tissue will parallel the DIC and include the capsule and portions of the DIC and DRC.

images  With the scaphoid, SLIL, and lunate exposed, note any arthritic changes, the location of the SLIL disruption (typically it avulses off the scaphoid) (TECH FIG 1B,C), and any injury to the DIC ligament.

images In cases of high energy the DIC may avulse off its scaphoid and lunate attachment.

images  Place joystick Kirschner wires (0.062 inch) into the scaphoid and the lunate.

images

TECH FIG 1 • A. Intraoperative photo demonstrating the exposure and location of the dorsal capsular ulnar-based flap. The DIC parallels the more distal transverse limb of the flap. S, scaphoid; L, lunate; T, triquetrum. B.Intraoperative photo demonstrating the flexed scaphoid (S), the capitate (C), and the extended lunate (L). A complete disruption of the scapholunate interosseous ligament (SLIL) is noted. The arrow points at the ulnar-based capsular flap. C. Intraoperative photo showing the scaphoid on the left and the SLIL still attached to the lunate on the right (held by forceps). The capitate head is seen distal to the lunate at the top of the photo. D.Intraoperative photo after suture anchor placement into the scaphoid at the dorsal SLIL footprint on the left, then passed through the SLIL shown on the right. The joystick Kirschner wires are placed into the scaphoid and the lunate in such a manner that when they are brought together, the dorsal intercalated segment instability (DISI) deformity will be corrected and the joint reduced. E. Intraoperative photo after reduction of the joint and DISI deformity using the joystick Kirschner wires and suture repair of the avulsed SLIL. The Kirschner wires in the scaphoid and in the lunate have been brought together from their divergent positions and are now in the same plane, correcting the DISI deformity. The two Kirschner wires have been placed from radial to ulnar (seen on the left of the image), passing through the scapholunate interval and scaphocapitate interval. F,G. AP and lateral intraoperative fluoroscopic images demonstrating Kirschner wire placement across the scaphocapitate joint and the reduced scapholunate joint. Suture anchors can be seen in the scaphoid at the dorsal SLIL footprint. This example shows a third, more distal suture anchor at the scaphoid that was used for dorsal capsule augmentation.

images Place these wires parallel to the scapholunate joint about 5 mm from the articular surface.

images The scaphoid joystick should angle proximally and the lunate joystick should angle distally (TECH FIG 1D).

images  The Kirschner wire joysticks are brought together, taking the scaphoid out of flexion and the lunate out of extension to correct any dorsal intercalated segmental instability deformity and reduce the joint.

images  Preliminarily reduce the scapholunate joint and identify the anatomic insertion site for the SLIL.

images  Roughen the SLIL footprint to bleeding bone on the dorsal ulnar portion of the scaphoid and insert one or more mini suture anchors (2.0 or 2.5 mm).

images  Pass the sutures from the suture anchor through the SLIL stump but do not tie them (TECH FIG 1D).

images  With the joint reduced via the joysticks, drive two 0.045-inch smooth Kirschner wires from the scaphoid into the lunate across the reduced scapholunate joint and drive one or two 0.045-inch Kirschner wires through the waist of the scaphoid into the capitate (TECH FIG 1EG).

images  Secure the SLIL to the prepared site by tying the suture anchor sutures.

images  Remove the joystick Kirschner wires and cut the remainder of the Kirschner wires below the skin.

images  Suture anchors are placed at the DIC footprint on the dorsal more distal scaphoid should it be avulsed and need repair or should capsular flap augmentation be desired (see Direct SLIL Repair with Dorsal Capsulodesis).

images  Close the capsule with 3–0 absorbable suture.

images  Transpose the EPL tendon subcutaneously and repair the extensor retinaculum with 3–0 absorbable suture.

DIRECT SLIL REPAIR WITH DORSAL CAPSULODESIS

images  Indications

images Tenuous SLIL repair

images Chronic scapholunate dissociation (>6 weeks) without arthritis

images   The deformity must be reducible and not fixed.

images  Should capsulodesis be required for augmentation, perform the SLIL repair as described above, making the same ulnar-based dorsal capsular incision.

images  After the SLIL is repaired, swing the ulnarly based capsular flap over the scapholunate interval and plan the location for its attachment to the scaphoid waist.

images Plan to secure the flap under tension to further stabilize the scapholunate joint.

images  Place one or two mini suture anchors (1.8 or 2.0 mm) into the scaphoid at the determined location and another mini suture anchor dorsal-central into the lunate.

images  With the capsular flap pulled taut, pass the scaphoid suture anchor sutures through the flap. Then pass the lunate sutures through the central aspect of the flap, estimating suture location to maximize stabilization of the scapholunate joint.

images  Once all sutures from the scaphoid and the lunate are placed through the capsular flap, tie them down (TECH FIG 2).

images

TECH FIG 2 • Repair augmentation with ulnar-based capsular (CAPS) flap. Note the suture anchor knots (arrows) and the location of the distal suture anchor at the scaphoid at the footprint of the dorsal intercarpal ligament.

images

images

POSTOPERATIVE CARE

images The wrist is immobilized in a short-arm thumb spica splint immediately after surgery.

images Sutures are removed at 2 weeks and the wrist is placed into a short-arm thumb spica cast for 8 weeks.

images Radiographs are obtained at 2 and 4 weeks to evaluate reduction and any pin migration.

images Pins are removed at 8 weeks and the wrist is placed back into a short-arm thumb spica splint.

images Gentle active range-of-motion exercises are allowed at 8 weeks, out of the splint for exercises only.

images Immobilization is discontinued at 12 weeks.

images Full activities are allowed at 4 to 6 months.

images Forced hyperextension (push-ups) and axial loading are especially restricted during the 4to 6-month postoperative period.

OUTCOMES

images Results following direct SLIL repair with capsulodesis are highly variable.

images By not crossing the radiocarpal joint with the capsulodesis, theoretically wrist motion will be maximized.

images Szabo et al9 showed mean loss of wrist flexion of 10 degrees, extension of 15 degrees, radial deviation of 20 degrees, and ulnar deviation of 11 degrees at 2 years of follow-up for chronic (>6 weeks) SLIL tears treated with DIC capsulodesis.

images Grip strength was unchanged from the preoperative assessment (mean 41).

images Results of the procedure typically do not hold over time radiographically.

images Minimum 5-year follow-up for chronic SLIL tears treated with DIC capsulodesis showed4 :

images Immediate postoperative scapholunate angle of 56 degrees at 5 years increased to 62 degrees

images Immediate postoperative scapholunate gap of 2.6 mm at 5 years increased to 3.5 mm

images Also, 50% of wrists show arthritic changes at 5 years.

images Radiographic changes have not correlated with clinical results over time.4

images Wrist flexion decreased 19 degrees at 5-year follow-up compared with preoperative values.

images Extension and radial and ulnar deviation remained unchanged at 5 years from the immediate postoperative values shown above.9

images Grip strength remained unchanged at 5 years (mean 43).

images Outcome instrument scores at 5 years (Mayo Wrist Score)

images 38% excellent, 19% good, 31% fair, 12% poor outcomes

images No correlation between subjective pain scores and radiographic changes has been shown at 5 years.

COMPLICATIONS

images Pin tract infections (this risk is minimized with buried pins)

images Superficial radial nerve injury

images The surgeon should keep skin flaps thick when dissecting on top of the extensor retinaculum (this keeps the superficial radial nerve branches within the flaps).

images The surgeon should make a small stab incision to bluntly dissect down to bone to minimize risk of nerve injury during pin placement.

images Loss of scapholunate reduction

images Arthritic changes in the radiocarpal and midcarpal joints

REFERENCES

1.     Blatt G. Capsulodesis in reconstructive hand surgery: dorsal capsulodesis for the unstable scaphoid and volar capsulodesis following excision of the distal ulna. Hand Clin 1987;3:81–102.

2.     Dao KD, Solomon DJ, Shin AY, et al. The efficacy of ultrasound in the evaluation of dynamic scapholunate ligamentous instability. J Bone Joint Surg Am 2004;86A:1473–1478.

3.     Darlis NA, Weiser RW, Sotereanos DG. Partial scapholunate ligament injuries treated with arthroscopic debridement and thermal shrinkage. J Hand Surg Am 2005;30A:908–914.

4.     Gajendran VK, Peterson B, Slater RR, et al. Long-term outcome of dorsal intercarpal ligament capsulodesis for chronic scapholunate dissociation. J Hand Surg Am 2007;32A:1323–1333.

5.     Geissler WB, Freeland AE, Savoie FH, et al. Intracarpal soft tissue lesions associated with an intra-articular fracture of the distal end of the radius. J Bone Joint Surg Am 1996;78A:357–365.

6.     Linscheid RL, Dobyns JH, Beabout JW, et al. Traumatic instability of the wrist: diagnosis, classification, and pathomechanics. J Bone Joint Surg Am 1972;54A:1612–1632.

7.     Schmid MR, Schertler T, Pfirrmann CW, et al. Interosseous ligament tears of the wrist: comparison of multi-detector row CT arthrography and MR imaging. Radiology 2005;237:1008–1013.

8.     Schweitzer ME, Brahme SK, Hodler J, et al. Chronic wrist pain: spinecho and short tau inversion recovery MR imaging and conventional MR arthrography. Radiology 1992;182:205–211.

9.     Szabo RM, Slater RJ, Palumbo CF, et al. Dorsal intercarpal ligament capsulodesis for chronic, static scapholunate dissociation: clinical results. J Hand Surg Am 2002;27A:978–984.

10. Taleisnik J. Post-traumatic carpal instability. Clin Orthop Relat Res 1980;149:73–82.

11. Viegas SF, Patterson RM, Hokanson JA, et al. Wrist anatomy: incidence, distribution, and correlation of anatomic variations, tears, and arthrosis. J Hand Surg Am 1993;18:463–475.

12. Watson K, Ballet FL. The SLAC wrist: scapholunate advanced collapse pattern of degenerative arthritis. J Hand Surg Am 1984; 9:358–365.

13. 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;78A:348–356.

14. Wintman BI, Gelberman RH, Katz JN. Dynamic scapholunate instability: results of operative treatment with dorsal capsulodesis. J Hand Surg Am 1995;20:971–979.



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