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Arthroscopy has revolutionized the practice of orthopaedics by providing the technical capability to examine and treat intra-articular abnormalities directly. The development of wrist arthroscopy was a natural evolutionary progression from the successful application of arthroscopy to other, larger joints. Wrist arthroscopy has seen considerable growth since Whipple et al. reported their original description of the techniques that they developed for viewing the anatomy of the wrist56. The wrist is a labyrinth of eight carpal bones, multiple articular surfaces with intrinsic and extrinsic ligaments, and a triangular fibrocartilage complex, all within a five-centimeter interval. This perplexing joint continues to challenge clinicians with an array of potential diagnoses and treatments. Wrist arthroscopy allows direct visualization of cartilage surfaces, synovial tissue, and ligaments under bright illumination and magnification. While most acute sprains of the wrist with normal radiographic findings resolve after temporary immobilization, how to further evaluate the patient who does not have improvement after such treatment is controversial. Tricompartmental wrist arthrography has historically been the so-called gold standard for the detection of intra-articular abnormalities9,10,43,54. However, the proved ability of wrist arthroscopy to enable detection and simultaneous treatment of wrist injuries, as well as the introduction of magnetic resonance imaging, has markedly altered this situation28,38,44. Adolfsson used arthroscopy to examine 144 patients who had posttraumatic wrist pain and normal findings on standard radiographs1. Ligamentous changes were observed in seventy-five patients; lesions of the triangular fibrocartilage complex, including lunotriquetral instability, in sixty-one patients; and varying degrees of scapholunate instability, in fourteen patients. The indications for wrist arthroscopy continue to expand as new techniques and instrumentation are developed. Diagnostic indications include assessment of tears of the interosseous ligaments and determination of whether they are partial or complete as well as evaluation of tears of the triangular fibrocartilage complex, chondral defects in the radiocarpal and midcarpal spaces, and chronic wrist pain of unknown etiology. Indications for operative intervention include treatment of fractures of the distal aspect of the radius and the scaphoid, stabilization of the interosseous ligaments, débridement of tears of the triangular fibrocartilage complex, synovectomy, distal ulnar shortening, detection and removal of loose bodies, ganglionectomy, and wrist lavage. The purpose of the current paper is to present the basic techniques of wrist arthroscopy and their application to common disorders of the wrist.
The space available for manipulation of the arthroscope and instrumentation in the wrist is substantially smaller than that available for arthroscopy of larger joints; wrist arthroscopy requires accurate placement and smaller instrumentation so that all areas can be examined, probed, and treated. Traction is essential for visualization12. This can be accomplished through use of a traction tower, which involves stabilization of the forearm unit in traction applied through finger-traps placed on two or three fingers distally (Fig. 1). This device allows easy access to all areas of the wrist, and the degree of traction can be adjusted by means of a gearing mechanism on the device itself. If a traction tower is not available, a shoulder-holder can be used overhead to support the wrist. A countertraction band is placed around the arm. Alternatively, the wrist can be aligned in a horizontal manner on a hand-table, and the arm is stabilized by a pulley or a padded post attached to the hand-table. Traction is provided through finger-traps attached to ten pounds (4.5 kilograms) of weight suspended over the end of the hand-table.
Instrumentation designed for small joints is absolutely essential for the successful performance of wrist arthroscopy46. Large-joint instrumentation used for knee and shoulder arthroscopy is not appropriate for arthroscopy of the wrist. The surgeon must have available an appropriate small-bore arthroscope, either 2.7 or 2.9 millimeters in diameter, which generally has either a 30 or a 70-degree visualizing angle. A videoprinter is helpful for documenting key aspects of the arthroscopy. A small wrist-arthroscopy probe is also extremely important as it allows tissues to be examined by manipulation within the joint. A small-joint shaver, 2.7 or 2.9 millimeters in diameter, with various tips available, is essential for débridement of torn or avulsed tissue. Various angled punches and grabbers are also useful, especially for treatment of a torn articular disc of the triangular fibrocartilage complex. The most important aspect of a successful wrist arthroscopy is a knowledge of the normal anatomy and the accurate placement of portals before the procedure7,8. Inappropriate placement of portals either too distal or too proximal along the wrist may cause injury to the articular cartilage or the triangular fibrocartilage complex. All portals should be drawn on the skin before the skin incision is made and after traction has been applied. The bases of the index, long, and ring-finger metacarpals are palpated and marked. The extensor carpi ulnaris tendon becomes prominent with traction, which makes it easy to palpate and identify. The tip of the surgeon's thumbnail can be used to roll over and mark the dorsal lip of the radius. If the wrist is not swollen from an acute injury, the extensor pollicis longus and extensor digitorum communis tendons can be palpated and marked. Portals are named according to the interspace through which they course with respect to the extensor compartments (Fig. 2). Therefore, the 34 portal courses between the third and fourth compartments at the dorsal aspect of the wrist. The 34 portal is located by palpating Lister's tubercle and moving the finger approximately one centimeter distally until a soft spot is noted between the third and fourth compartments. The 34 portal also is in line with the radial border of the long finger. The 45 portal is located by the surgeon rolling his or her finger over the palpable fourth compartment and identifying the soft spot opposite the 34 portal on the ulnar aspect of the fourth compartment. The surgeon must always be cognizant of the normal angle of inclination of the distal aspect of the radius (radial inclination). As a general rule, the 45 portal lies slightly more proximally than the 34 portal because of radial inclination. The 6-R and 6-U portals are named according to their positions relative to the extensor carpi ulnaris tendon, with the 6-R portal being radial and the 6-U portal, ulnar to the tendon.
Before the introduction of a trocar into the wrist, the joint capsule should be inflated with irrigation fluid. This can be done by introduction of three to five milliliters of irrigation fluid through a syringe into the radiocarpal joint or by placement of a separate inflow portal before the procedure to allow expansion throughout the operation. The dorsal aspect of the capsule over the 34 portal bulges as the fluid is injected into the wrist joint. Pressurized controlled pumps, which recently have become available, can provide a feedback mechanism to maintain a constant pressure or flow of the irrigation fluid in the wrist in order to prevent extravasation and to maintain appropriate pressures throughout the procedure. All portal incisions should be longitudinal so that the extensor tendons are not transected transversely if the knife blade is passed too deep inadvertently. In order to ensure ideal placement of the portal, a needle is placed intra-articularly in the proposed location of the portal before the skin is incised. In order to avoid injury to the underlying sensory branches of the radial and ulnar nerves, the surgeon uses his or her thumb to pull the skin against the tip of a number-11 scalpel blade so that only the skin is incised. A cannula with a blunt trocar should be placed at approximately a 30 to 40-degree angle pointing proximally in the wrist to allow the cannula to enter in line with the articular surfaces. The midcarpal portals are essentially made one centimeter distal to the 34 and 45 portals12. The midcarpal space is somewhat tighter than the radiocarpal space, so extra care must be taken while entering it with the blunt trocar. Once the trocar sheaths have been placed successfully, they should be maintained, as some extravasation of fluid generally occurs and makes reintroduction of the trocar and sheath more difficult than it is at the beginning of the procedure. The 34 portal is the primary viewing portal, and either the 45 or the 6-R portal is the main working portal. Inflow is usually through the 6-U portal, and outflow is through the arthroscopic cannula in order to limit extravasation of fluid into the soft tissues. An intravenous extension tubing is connected to the cannula and drains into a basin. The radial styloid process as well as the proximal aspect of the scaphoid can be examined for any signs of osteoarthritic changes or synovitis, which are occasionally seen. As ulnar translation is begun, the volar extrinsic ligaments become clear, with the radioscaphocapitate ligament and the immediately adjacent long radiolunate ligament identified first5. The long radiolunate ligament is an extremely wide structure that is usually two to three times the width of the radioscaphocapitate ligament (Fig. 3)6,37. Just ulnar to the long radiolunate ligament is the short radiolunate ligament, which is a vascularized tuft without any distinguishing structural architecture. Blood vessels are frequently noted along this ligament. Distal to the short radiolunate ligament is the intrinsic scapholunate ligament, which generally has a slightly concave shape due to the normal curvature of the scaphoid and the lunate at their junction. This ligament can be examined from the membranous proximal portion to the thicker ligamentous dorsal portion. The radiocarpal joint is followed along the lunate fossa of the distal aspect of the radius with the deep volar structures, out to the junction of the distal part of the radius, at the ulnar aspect, and the articular disc of the triangular fibrocartilage complex. A probe is drawn across the articular disc, which should be fairly taut, similar to a trampoline, and an actual ballottement maneuver of the disc by the probe is performed (the trampoline test). When the articular disc is floppy and floating without tension as demonstrated by the trampoline test, a tear in either the central or the peripheral portion must be suspected. The surgeon must be aware of the ulnar styloid recess, which can be mistaken for a peripheral tear but is a normal anatomical finding in the distal ulnar portion of the triangular fibrocartilage complex. Examination of the lunotriquetral interosseous and ulnocarpal ligaments is best performed by placing a sheath in the 45 or 6-R portal and switching the arthroscope to that portal. The ulnolunate and ulnotriquetral ligaments are identified as capsular thickenings in the volar aspect of the ulnar capsule.
After appropriate evaluation of the radiocarpal joint, both the arthroscope and the probe are placed in the midcarpal portals52. The arthroscope is usually placed in the radial midcarpal space. Occasionally, in small wrists, it may be easier to place the arthroscope in the ulnar midcarpal portal. Immediately on examination of the midcarpal portal, the main concave curvature of the capitate head is noted distally. By viewing proximally through the arthroscope, the surgeon can easily identify both the scapholunate joint (on the radial aspect) and the lunotriquetral joint (on the ulnar aspect). Both joints should be probed to ensure that no instability is present. The scaphotrapeziotrapezoid joint can be seen by passing the arthroscope completely radially, and early osteoarthritic changes can be noted with use of this technique. When the arthroscope is moved completely ulnarly, the capitohamate joint can also be identified and examined. When there is midcarpal instability, a greater-than-normal amount of the volar aspect of the capsule between the hamate and the triquetrum is visualized.
The key to arthroscopic treatment of carpal instability is recognition of what is normal and what is pathological anatomy. Both the radiocarpal and the midcarpal space must be evaluated arthroscopically when carpal instability is suspected. Wrist arthroscopy is not complete if the midcarpal space is not examined with consideration of the possibility of carpal instability. When the interosseous ligament tears, it hangs down and blocks visualization with the arthroscope in the radiocarpal space. The degree of rotation of the carpal bones and any abnormal motion are best appreciated from the unobstructed view available in the midcarpal space. A limited type of intraoperative arthrogram (a so-called poor man's arthrogram) may be performed for the evaluation of carpal instability. After the radiocarpal space has been examined, the inflow cannula is left in the radiocarpal space. A needle is then placed in either the radial or the ulnar midcarpal portal. If a free flow of irrigation fluid is seen, then a tear of the interosseous ligament is suspected. The scapholunate and lunotriquetral interosseous ligaments should have a concave appearance as seen from the radiocarpal space. The lunotriquetral interosseous ligament is best visualized with the arthroscope in the 45 or 6-R portal because of its oblique relationship in the proximal carpal row (Fig. 4). It is not easily visualized with the arthroscope in the 34 portal, particularly in small wrists. In the midcarpal space, the scapholunate interval should be tight and congruent, without a step-off. Similarly, the lunotriquetral interval should be congruent, but occasionally a one-millimeter step-off, which is normal, is seen from the midcarpal space (Fig. 5). There is normally slight motion between the lunate and the triquetrum.
A spectrum of injury of the scapholunate and lunotriquetral interosseous ligaments is possible. The interosseous ligaments appear to attenuate and then tear from volar to dorsal. One of us (W. B. G.) devised an arthroscopic classification of carpal instability and suggested that acute lesions be treated on the basis of observations of tears of the scapholunate and lunotriquetral interosseous ligaments associated with fractures of the distal aspect of the radius (Table I)19. In grade-I injuries, there is loss of the normal concave appearance between the scaphoid and either the lunate or the lunotriquetral interval and the interosseous ligament bulges, with a convex appearance. Evaluation from the midcarpal space shows the carpal bones to be congruent. In grade-II injuries, the interosseous ligament becomes convex, as in grade-I injuries, but the carpal bones are no longer congruent in the midcarpal space. There is slight palmar flexion of the scaphoid, and its dorsal edge is distal compared with that of the lunate (Fig. 6). In injuries of the lunotriquetral ligament, there is increased motion between the lunate and the triquetrum. In grade-III injuries, the interosseous ligament starts to separate and a gap is seen between the carpal bones from both the radiocarpal and the midcarpal space. A one-millimeter probe may be passed through the gap between the involved carpal bones from the midcarpal to the radiocarpal space, depending on which interosseous ligament is torn. A dorsal portion of the ligament is still attached. In grade-IV injuries, the interosseous ligament is completely detached and a 2.7-millimeter arthroscope may be passed freely from the midcarpal space to the radiocarpal space between the involved carpal bones (Fig. 7). This corresponds to the widened scapholunate gap seen on posteroanterior radiographs of a wrist with complete scapholunate dissociation.
Acute tears of the scapholunate or lunotriquetral interosseous ligament that result in incongruency as seen from the midcarpal space may be arthroscopically reduced and pinned. In patients who have scapholunate instability, the arthroscope is initially placed in the 34 portal. A 0.045-inch (0.114-centimeter) Kirschner wire is placed through a soft-tissue protector or a 16-gauge needle dorsal in the anatomical snuffbox into the scaphoid. With the surgeon looking down the radial gutter through the arthroscope, the wire may be seen entering the scaphoid. Alternatively, the surgeon can begin placing the Kirschner wire into the scaphoid, aiming it toward the lunate, under fluoroscopic control. The arthroscope is then placed in the ulnar midcarpal portal. This enables the surgeon to look across the wrist to better judge the rotation of the scaphoid and the lunate. A Kirschner wire may also be inserted into the lunate and used as a joystick to control rotation as the scapholunate interval is anatomically reduced, as seen from the midcarpal space. The surgeon then advances the Kirschner wire across the scapholunate interval, aiming for the lunate, which is between the midcarpal and radiocarpal portals. Droplets of fat are seen exiting between the scaphoid and the lunate in the midcarpal space as the wire is driven across the interval. After the first Kirschner wire that controls rotation is placed, additional wires are placed arthroscopically or under fluoroscopic control. Three or four Kirschner wires are normally placed and left in position for eight weeks. The wrist is immobilized in a below-the-elbow cast, and the wire tracks are evaluated every two weeks. The wires are removed at eight weeks, and the wrist is immobilized for an additional four weeks in a removable below-the-elbow splint. Physical therapy, including range-of-motion and grip-strengthening exercises, is initiated at three months. Grade-IV injuries are usually reduced and stabilized through an arthrotomy to obtain primary repair of the dorsal portion of the scapholunate interosseous ligament. The technique for the treatment of lunotriquetral instability is essentially the same as that just described, except that the arthroscope is placed in the radial midcarpal space so that the reduction of the lunotriquetral interval can be monitored. It is very important to place the Kirschner wires through a soft-tissue protector in order to avoid injury to the dorsal sensory branch of the ulnar nerve. The rotation through the lunotriquetral joint is usually not as difficult to control as is that at the scapholunate interval. Whipple reviewed the results of arthroscopic treatment of scapholunate instability, as just described, in patients who were followed for a duration of one to three years59. The patients were classified into two distinct groups of forty patients each according to the duration of symptoms and the side-to-side radiographic differences in the scapholunate gap. Thirty-three patients (83 percent) who had a history of instability of three months or less and had less than three millimeters of side-to-side difference in the scapholunate interval had maintenance of the reduction and symptomatic relief, compared with only twenty-one patients (53 percent) who had had symptoms for more than three months and had more than three millimeters of side-to-side difference. Osterman and Seidman reported the results of arthroscopic treatment of acute instability of the lunotriquetral ligament in twenty consecutive patients who did not have instability of the volar intercalated segment41. At an average of two years and eight months after the procedure, sixteen patients had good-to-excellent relief of pain. At the time of the latest physical examination, loss of wrist extension averaged 17 percent and loss of wrist flexion averaged 25 percent. Grip strength improved in eighteen patients. Chronic tears of the interosseous ligaments lose their intrinsic ability to heal, as shown clinically by Whipple59. Weiss et al. examined the role of arthroscopic débridement alone for the treatment of complete and incomplete intercarpal tears of the wrist55. At an average of twenty-seven months after the procedure, nineteen of twenty-nine patients who had had a complete tear of the scapholunate interosseous ligament and thirty-one of thirty-six patients who had had an incomplete tear had either complete resolution of or a decrease in the symptoms. Twenty-six of thirty-three patients who had had a complete tear of the lunotriquetral interosseous ligament and all forty-three patients who had had a partial tear had complete resolution of or a decrease in the symptoms. Grip strength improved an average of 23 percent. The arthroscopic technique for débridement is relatively straightforward. The arthroscope is placed in the 45 portal, and a shaver is placed in the 34 portal to debride the scapholunate interosseous ligament. The goal is to debride unstable tissue flaps back to stable tissue. The lunotriquetral interosseous ligament is debrided similarly, with the shaver in the 6-R portal and the arthroscope in the 34 portal. It may be necessary to place the arthroscope intermittently in the 6-R portal in order to evaluate the result, as it is difficult to see the lunotriquetral interval from the 34 portal. Arthroscopic débridement of chronic tears is most effective if there is no carpal collapse.
Anatomy and Function
Clinical Presentation and Suggested Treatment
Traumatic InjuriesClass I
Class-IB injuries are traumatic avulsions of the triangular fibrocartilage complex from its insertion into the distal aspect of the ulna; they may or may not be accompanied by a fracture of the ulnar styloid process at its base. These injuries are usually associated with distal radioulnar instability. The patient usually has tenderness around the 6-U portal, and the pain may be reproduced with ulnar deviation of the wrist. A triple arthrogram may demonstrate normal findings, and arthroscopic examination usually shows loss of tension of the articular disc of the triangular fibrocartilage complex. There may be hypertrophic synovitis covering the torn part of the ulnar-dorsal portion of the articular disc, and débridement will help in locating the tear. Various arthroscopic suturing techniques have been described for repair of ulnar peripheral tears. For tears that extend dorsally, Whipple et al. described an outside-in technique that involves placing sutures longitudinally to reattach the central cartilage disc to the floor of the fifth and sixth extensor compartments11,57,60. The arthroscope is normally inserted in the 34 portal. After establishment of a 6-R portal, fibrovascular tissue is debrided and the dorsal margin of the central disc is freshened with a small motorized shaver. A longitudinal incision, approximately twelve to fifteen millimeters in length and incorporating the 6-R portal, is then made. The retinaculum of the extensor carpi ulnaris is opened and the tendon is retracted, usually radially. A curved cannulated needle and suture retriever are introduced through the floor of the extensor compartment; the needle is inserted at the level of the distal radioulnar joint, and the suture retriever is inserted at the radiocarpal level. The suture is advanced through the needle, brought through the dorsal aspect of the capsule with use of the suture retriever's wire loop, and tied on the floor of the extensor carpi ulnaris sheath with the wrist in supination (Fig. 10). Normally, two or three sutures are sufficient to close the tear (Fig. 11). The retinaculum can then be closed with a single suture, and the skin edges also are closed.
It is not necessary to disturb the extensor carpi ulnaris tendon when the tear lies over the ulnar styloid process. To treat these injuries, a 1.5-millimeter drill-hole is made obliquely, under fluoroscopic control, through the base of the ulnar styloid process24. A straight needle is used to pass a suture through the drill-hole and then distally through the ulnar edge of the articular disc. The suture is retrieved through a 6-U portal that has been made inside the operative incision and is tied around the volar edge of the ulnar styloid process. The limb is then placed in an above-the-elbow cast or a sugar-tong splint in slight supination for four weeks, after which a removable or rigid splint is worn for an additional three weeks. With use of the technique reported by Ekman and Poehling12, the arthroscope is placed in the 45 portal and a 20-gauge anesthesia needle is placed in the radiocarpal joint through either the 12 or the 34 portal. Under direct visualization, the needle is passed through the torn edge of the articular disc and the ligamentous tissue above the ulnar styloid process, then out through the soft tissue and skin. A 2-0 absorbable suture is threaded through the entire needle and is anchored at each end with hemostats. The needle is then brought back into the joint space and is passed through the edge of the tear again; it is advanced through the ligamentous tissue on the ulnar side of the joint and out through the soft tissue and skin, with the suture traveling through the soft tissue both inside and outside the needle. The suture is pulled out of the needle on the ulnar side of the wrist. This process is repeated until three sutures are in place; the needle can then be removed from the wrist. Blunt subcutaneous dissection is then carried out and, under direct visualization from the 45 portal, all sutures are pulled back through the skin and out through the single incision. The sutures are tied and buried when the skin is closed. The Chow technique consists of use of a needle with a wire loop to capture the suture once it is passed intra-articularly, in order to reattach the triangular fibrocartilage complex to the joint capsule. The arthroscope is normally engaged in the 34 portal, and the 6-U portal is used for assistance. A 25-gauge needle, with the head removed to gain access from the outside, is used as a guide for insertion of the repair sutures. The 45 and 6-R portals are the most common suturing sites. The wire loop is brought back inside the straight needle, which will be used to capture the suture, and the needle is inserted on the distal side of the triangular fibrocartilage complex; the 25-gauge needle is used for guidance, with care being taken to ensure that the bevel of the needle is facing up in order to avoid damage to the articular surface. The second straight needle, containing the suture inside, is inserted four to five millimeters proximal to the first needle with the bevel inserted facedown and the sharp-tipped edge pointed upward to facilitate puncturing of the articular disc. A small bassinet or holder inserted from the 6-U portal is used to assist in passing the suture by holding the free edge of the tear. Once the needle has passed through the articular disc, the wire loop is advanced from the first needle to loop around the second needle. Gentle turning of the second needle, so that the bevel is facing up, engages the wire loop further while it is gently pulled to further engage the second needle. The suture is then passed through the second needle and is grasped with a grasper inserted through the 6-U portal. The second needle is then pulled back gently through the articular disc to avoid cutting the suture, and the suture is retrieved through the 6-U portal by gently tugging the grasper. The end of the suture is secured to the second needle with a hemostat and the wire loop is retracted, pulling the suture back through the 6-U portal and out the dorsal aspect of the wrist, where it is secured. A small incision is made between the sutures, and the joint capsule is bluntly dissected with a hemostat, under direct visualization through the arthroscope, with care being taken not to trap any tendons or to puncture the joint capsule. A probe is inserted into the incision and is looped around the suture, at the top and at the bottom, to bring it out through the center incision; hemostats are used to tack down the suture for future tying. A surgeon's knot is preferred for the first knot, followed by insertion of the probe under arthroscopic visualization to ensure that the suture is tight and that no tissue or tendons are caught in it. Class 1C comprises peripheral tears of the triangular fibrocartilage complex, usually involving the distal attachment of the lunate or the triquetrum. This type of injury frequently results in ulnocarpal instability, demonstrated by palmar translocation of the ulnar aspect of the carpus in relation to the radius or the ulnar head, or both. The patient usually has palmar tenderness over the pisiform bone, with pain and locking on the ulnar side when performing a firm grip. Class-IC lesions with no wrist instability are usually treated with immobilization in a cast for six weeks. Trumble et al. described a technique of arthroscopic repair of these lesions that yielded good results49. Class-ID injuries of the triangular fibrocartilage complex are quite severe and involve traumatic avulsion of the articular disc from the attachment on the sigmoid notch, usually associated with a fracture in the region of the sigmoid notch. Patients who have this type of injury usually have diffuse tenderness along the entire ulnar aspect of the wrist and may also have hemarthrosis of the wrist joint. In the past, immobilization for about six weeks was recommended in order to allow the injury to heal, as the articular disc is intact21. Recently, Sagerman and Short suggested arthroscopic reattachment47. After débridement of the osseous rim of the sigmoid notch, the radial edge of the horizontal disc is reattached to the bone by means of two holes, with small Kirschner wires inserted percutaneously into the joint from the sigmoid notch across the distal aspect of the radius. Long meniscal repair needles are inserted through the drill-holes in order to place two nonabsorbable sutures into the horizontal disc and out the radial aspect of the wrist. A small incision is made so that these sutures can be tied directly over the radius. The distal radioulnar joint is then pinned in neutral position with one 0.062-inch (0.157-centimeter) Kirschner wire inserted percutaneously. The wrist is immobilized in an above-the-elbow cast for four weeks and in a removable below-the-elbow splint for an additional four weeks. Fellinger et al. reported a new technique involving use of a meniscal T-shaped suture anchor to repair radial peripheral tears13. It must be noted that repair of radial tears is controversial because of the lack of blood supply to the radial side of the disc.
Degenerative LesionsClass II Perforation of the triangular fibrocartilage complex and chondromalacia of the lunate or the ulna, or both, is classified as a class-IIC lesion; if, in addition to these characteristics, there is perforation of the lunotriquetral ligament, the lesion is classified as class IID; and if, in addition to these characteristics and perforation of the lunotriquetral ligament, there is ulnocarpal osteoarthritis, the lesion is classified as class IIE. Treatment of class-IIC, IID, and IIE symptomatic lesions includes arthroscopic débridement and ulnar shortening if the patient has ulnar-plus syndrome27,39. The ulnar head may be shortened arthroscopically or by means of an open ulnar shortening osteotomy. For the arthroscopic technique, the arthroscope is inserted in the 34 portal and a burr is placed in the 6-R portal. The head of the ulna is resected through the defect of the torn articular disc. The wrist is pronated and supinated to gain access to the peripheral margins of the ulnar head. The burr may be placed proximal to the articular disc through the distal radioulnar joint portal for improved access to the ulnar head. The most common question regarding the wafer procedure is how much bone needs to be resected50,61. Under normal conditions, less than four millimeters of bone should be resected. Fluoroscopy should be used to monitor the resection, as magnification makes it difficult to judge arthroscopically the amount of bone being excised. Care should be taken not to stray and remove too much articular cartilage from the distal radioulnar joint. The surgeon should ensure the preservation of the stability of the distal radioulnar joint by not removing the origins of the radioulnar and ulnar carpal ligaments. Nagle recommended use of a laser to resect the ulnar head to the osseous section before using the burr36.
The treatment of displaced fractures of the distal aspect of the radius includes restoration of radial length, articular inclination, and anatomical or nearly anatomical joint congruity2,4,29,53. Over the years, two millimeters has become a well established critical threshold tolerance for distal radial intra-articular incongruity52. However, recent investigations have indicated that the critical tolerance may be as low as one millimeter16,32,33,48,51. Fractures should be fixed when closed reduction can be achieved but cannot be maintained. Arthroscopically assisted treatment is optimum for simple intra-articular fractures that have large, well defined fragments, such as fractures of the radial styloid process, dorsal and volar die-punch fractures, dorsal and palmar radial rim (Barton-type) fractures, and three or four-part intra-articular fractures of the distal aspect of the radius16-18,20,42,51,58,62. A simple uncomminuted displaced fracture of the radial styloid process is an excellent case for the beginner in arthroscopically assisted reduction and fixation of distal radial fractures, as there is only one major fracture incongruity to realign and it is usually a rotational deformity. Nevertheless, as many as approximately 20 percent of these fractures (forty-eight of 240) may necessitate conversion to an open procedure to achieve adequate reduction, fixation, or bone-grafting31,51. Both intra-articular and extra-articular fractures of the distal aspect of the radius have a high prevalence of associated injuries of the scapholunate and lunotriquetral ligaments as well as of the triangular fibrocartilage complex14,18-20,23,25,26,30,34,35,42,45. Some of the more severe of these soft-tissue injuries can be diagnosed indirectly on the basis of intercarpal gaps or malalignment seen on plain or traction radiographs or on the basis of clinical examination. Arthroscopy performed at the time of treatment of the fracture substantially increases the recognition of these injuries as well as the identification of their extent and the degree of any accompanying instability18-20,30,45. It also provides an opportunity for early, definitive treatment.
Operative Technique The operating theater is set up so that both fluoroscopy and arthroscopy can be performed. The wrist may be suspended vertically in a traction tower or horizontally by a weight over the end of the hand-table. The traction tower allows the wrist to be manipulated while constant traction is maintained. However, many surgeons are more familiar with the anatomy of the wrist in the horizontal position, and this position makes it easier to use fluoroscopy to help monitor the reduction. A compressive bandage can be wrapped around the forearm to prevent extravasation of fluid into the muscle compartments of the forearm. The wrist is suspended in the traction tower with approximately ten pounds (4.5 kilograms) of measured distraction. Inflow is established through the 6-U portal. A 2.7-millimeter, 30-degree small-joint arthroscope is inserted in the 34 radiocarpal portal. Outflow is established through the arthroscopic cannula. A primary working portal is established in the 45 portal. Additional working portals can be established at the 12 and 6-R positions if needed. Hematoma and debris are removed with use of lavage, suction, mini-grasping forceps, and a 2.9-millimeter small-joint shaver until there is optimum visualization of the fracture. Fluoroscopy is used to select the site of entry of the Kirschner wire as it is superior to arthroscopy for this purpose. A portal-sized (one to 1.5-centimeter) incision can be made and centered over the area of wire application. Only the skin is incised. A drill-guide, tap-sleeve, or 14-gauge needle from an intravenous catheter is placed over the Kirschner wire and into the small incision; it is placed directly on bone in an effort to provide maximum soft-tissue protection while drilling. The Kirschner wire can be introduced into the fragment without crossing the fracture line. Like the site of entry, the position of the Kirschner wire within the fragment can be selected and monitored fluoroscopically. Additional pointed instruments, such as a Kirschner wire, a Steinmann pin, a pointed bone awl, dental picks and elevators, or pointed reduction forceps applied near the center of the fracture fragment, can be helpful in achieving or maintaining the reduction or even in compressing the fracture after reduction (Figs. 12-A and 12-B). Small intra-articular probes often can be used to elevate fracture fragments under direct arthroscopic visualization.
When an acceptable reduction is achieved, it can be further secured with additional Kirschner wires or screws (cannulated or uncannulated). It must be remembered that Kirschner wires provide splinting but not compression. Screws can compress, but the surgeon must be careful not to tighten them too much, especially in osteopenic bone. If a large bone defect is discovered during reduction and fixation, an appropriate operative approach should be used and either autogenous cancellous bone graft or bone-graft substitute can be applied. A limited dorsal incision over the distal aspect of the radius exposes the third dorsal compartment. Cancellous bone graft can be inserted into the barrel of a ten-millimeter syringe and compressed with the plunger15. The plunger is then removed from the syringe, the barrel is turned upside down, and the compressed cancellous bone is pushed out with use of a long number-20 or number-18 spinal needle. Compressed cancellous bone graft provides increased structural support and helps to ensure fracture-healing when a bone defect is present. The Kirschner wires are usually left in place for four to six weeks. The tension of the skin about the wire is routinely relieved by incision so that the skin does not fret on the adjacent wire, causing pain, discomfort, and sometimes infection. The wire is either cut beneath the skin or allowed to protrude through it, at the discretion of the surgeon. The fracture is protected for at least three and a half to four weeks, with either a plaster cast or a fracture-brace. It is important that the cast or brace does not extend distal to the distal palmar crease or block excursion of the metacarpophalangeal joints. This allows rehabilitation of the fingers while the wrist is healing. The second four-week period is dedicated to recovery of motion of the wrist and the forearm. In the third four-week period, progressive strength and conditioning exercises are initiated.
The arthroscopic removal of dorsal carpal ganglia was recently advocated by Osterman and Raphael, who reported excellent preliminary results40. Use of the arthroscope for this purpose has several advantages compared with open excision40. The arthroscopic procedure can be performed with much less scarring and cosmetic disfiguration, and quicker improvement in the postoperative range of motion has been noted. In addition, the rate of recurrence appears to be extremely low after removal of the ganglia, and the scapholunate ligament (often the culprit in the formation of dorsal carpal ganglion cysts) can be examined3. The arthroscope is placed in the 45 or 6-R portal, and the shaver is placed in the 34 portal22. The shaver is used to fashion a hole in the dorsal aspect of the capsule, opposite the scapholunate ligament, which can be visualized easily. The hole is made dorsally and distally, as the scapholunate ligament attaches to the dorsal aspect of the capsule. This area is in the location of the stalk of the dorsal carpal ganglion cyst (Fig. 13-A). The extensor carpi radialis brevis tendon should be visualized through the hole in the dorsal aspect of the capsule to ensure that a full-thickness débridement of the capsule has been performed (Fig. 13-B). This tendon is also easily followed distally and points to the area of the junction of the dorsal aspect of the capsule and the scapholunate interval. Palpation of the ganglion cyst demonstrates a sudden blush and release of the cyst after the stalk and the ganglion have been debrided (Fig. 13-B).
Very little if any formal hand therapy is needed postoperatively, and patients are encouraged to begin range-of-motion exercises on the following day, while wearing the soft bulky dressing.
Complications of wrist arthroscopy are rare and can usually be prevented57. A few millimeters can make a difference with regard to placement of the portals. The surgeon should be thoroughly familiar with the anatomical landmarks and the locations of the portals. The needle should always be placed in the proposed location of the portal to ensure that it enters the joint unobstructed before the skin incision is made. It is important to use blunt trocars when the cannula is introduced, in order to prevent damage to the articular cartilage. Separate inflow and outflow portals limit extravasation of fluid into the soft tissues. Use of a physiological solution such as Ringer's lactate solution allows absorption of fluid in the soft tissues, thus decreasing the risk of compartment syndrome. Kirschner wires should be inserted with use of soft-tissue protection in order to limit damage to sensory cutaneous nerves.
In conclusion, wrist arthroscopy continues to grow in popularity as a vital adjunct in the treatment of disorders of the wrist. It allows for evaluation of the intracarpal structures under bright, magnified conditions, with minimum morbidity compared with that associated with arthrotomy. Improved techniques will continue to emerge as more surgeons are instructed in the use of wrist arthroscopy and better instrumentation is developed. NOTE: The authors wish to give special thanks to Terry L. Whipple, M.D., for his ingenuity in developing many of the techniques described in this paper and for his generosity in sharing them with us.
*Printed with permission of the American Academy of Orthopaedic Surgeons. This article will appear in Instructional Course Lectures, Volume 49, American Academy of Orthopaedic Surgeons, Rosemont, Illinois, March 2000.
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