Wrist Arthroscopy Technique

Updated: Sep 21, 2017
  • Author: John J Walsh, IV, MD; Chief Editor: Harris Gellman, MD  more...
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Technique

Approach to Carpal Instability

Recognition of what is normal and what is pathologic is the key to arthroscopic treatment of carpal instability. If carpal instability is suspected, both the radiocarpal and midcarpal spaces must be examined. Interosseous ligament tears may block visualization in the radiocarpal space; thus, the degree of rotation of the carpal bones and abnormal motion are appreciated best by viewing from the midcarpal space. A limited type of intraoperative arthrogram may be performed for the evaluation of carpal instability. [45]

After examination of the radiocarpal space, the inflow cannula is left in the radiocarpal space, and a needle is placed in either the radial or ulnar midcarpal portal. If a free flow of irrigation is present, a tear of the interosseous ligament should be suspected.

Arthroscopic viewing portals

The scapholunate and lunotriquetral interosseous ligaments should have a concave appearance when viewed from the midcarpal space. The lunotriquetral interosseous ligament is observed best with the arthroscope in the 4-5 or 6-R portal because of this ligament's oblique relation in the proximal carpal row (see the image below); the lunotriquetral interosseous ligament is also not easily observed from the 3-4 portal, especially in small wrists.

Lunotriquetral ligament, as depicted from the 4-5 Lunotriquetral ligament, as depicted from the 4-5 portal in the radiocarpal space.

When viewed from the midcarpal space, the scapholunate interval should be tight and congruent; no stepoff should be present. The lunotriquetral interval should also be congruent, but occasionally a 1-mm stepoff is observed when the ligament is viewed from the midcarpal space. Normally, slight motion between the lunate and the triquetrum is present.

Grading of injury

A spectrum of injury of the scapholunate and lunotriquetral ligaments is possible. The ligaments appear to first attenuate and then to tear from a volar-to-dorsal direction. Geissler et al devised an arthroscopic classification of carpal instability (see Table 1 below). [46]

Table 1. Arthroscopic classification of carpal interosseous ligament tears (Adapted from Geissler et al. [46] ) (Open Table in a new window)

Grade Description Management
I Attenuation and/or hemorrhage of the interosseous ligament as observed from the radiocarpal joint. No incongruence of carpal alignment in midcarpal space. Immobilization
II Attenuation and/or hemorrhage of the interosseous ligament, as observed from the radiocarpal joint. Incongruence and/or stepoff, as observed from the midcarpal space. A slight gap (less than the width of a probe) between the carpals may be present. Arthroscopic reduction and pinning
III Incongruence and/or stepoff of the carpal alignment are observed in both the radiocarpal and midcarpal space. The probe may be passed through a gap between the carpals. Arthroscopic reduction and/or open reduction and pinning
IV Incongruence and/or stepoff of the carpal alignment are observed in both the radiocarpal and midcarpal space. Gross instability with manipulation is noted. A 2.7-mm arthroscope may be passed through the gap between the carpals. Open reduction and repair

In grade I injuries, the normal concave appearance between the scaphoid and either the lunate or the lunotriquetral interval is lost. The lunotriquetral interosseous ligament bulges, with a convex appearance. When examined from the midcarpal space, the bones are shown to be congruent.

In grade II injuries, the interosseous ligament becomes convex, as in grade I injuries; however, congruency between the two carpal bones when they are viewed from the midcarpal space no longer exists. A slight palmar flexion of the scaphoid is present, and its dorsal edge is distal when compared with that of the lunate. When the lunotriquetral interosseous ligament is injured, increased motion between the lunate and the triquetrum is observed from the midcarpal space.

In grade III injuries (see the image below), the interosseous ligament begins to separate, and a gap is observed between the two carpal bones (either the scaphoid and lunate or the lunate and triquetrum) when they are viewed from both the radiocarpal and the midcarpal space. A 1-mm probe may be passed through the gap between the involved carpal bones and twisted. This type of injury is not a complete tear, because a dorsal portion of the ligament is still attached.

Grade III scapholunate tear, as depicted from the Grade III scapholunate tear, as depicted from the midcarpal space. Note that the gap allows passage of a 1-mm probe.

In grade IV injuries, the interosseous ligament is completely detached, and a 2.7-mm arthroscope may be passed freely from the midcarpal space to the radiocarpal space (see the images below). This type of injury corresponds radiographically to the widened scapholunate gap that is observed on posteroanterior radiographs of a wrist that has complete scapholunate dissociation.

Grade IV scapholunate tear, as depicted from the m Grade IV scapholunate tear, as depicted from the midcarpal space. A 2.7-mm arthroscope may be freely passed through the tear.
Posteroanterior radiograph of a wrist. Abnormal wi Posteroanterior radiograph of a wrist. Abnormal widening between the scaphoid and lunate is present, indicating a complete scapholunate tear.

Reduction and pinning

As observed from the midcarpal space, acute tears of the scapholunate or lunotriquetral interosseous ligaments may be arthroscopically reduced and pinned.

In scapholunate instability, the arthroscope is initially placed in the 3-4 portal. A 0.045-in. Kirschner wire (K-wire) is placed through either a soft-tissue protector or 16-gauge needle dorsal in the anatomic snuffbox into the scaphoid. Arthroscopically viewing down the radial gutter, the surgeon can observe the K-wire enter the scaphoid. Alternatively, fluoroscopy can be used to place the K-wire into the scaphoid at the correct angle to engage the lunate.

Next, the arthroscope is placed in the ulnar midcarpal portal. This affords the surgeon a better view and allows the ability to judge the rotation of the scaphoid and lunate. K-wires and joysticks are inserted into the lunate and scaphoid and may be used to gain rotational control.

When the carpal bones are congruent as observed from the midcarpal space, the K-wire is driven across the scapholunate interval and aimed toward the lunate, which is between the midcarpal and radiocarpal portals. As the wire crosses the scapholunate interval, droplets of fat may be observed. After rotational control is gained, additional wires for stability may be inserted arthroscopically or fluoroscopically. Usually, three or four wires are placed, the wrist is immobilized in a below-the-elbow splint, and the wire tracks are evaluated every 2 weeks. After 8 weeks, the wires are removed.

The wrist is immobilized for an extra 4 weeks in a removable below-the-elbow splint. Therapy consisting of range-of-motion (ROM) exercises and grip strengthening is started after 3 months. Grade IV injuries are best reduced and stabilized through an arthrotomy to obtain primary repair of the dorsal portion of the interosseous ligament.

Lunotriquetral instability is treated essentially in the same manner as scapholunate instability, but with some minor changes. The arthroscope is placed in the radial midcarpal space so that the reduction of the lunotriquetral can be monitored. K-wire placement should be done through a soft-tissue protector to avoid injury to the dorsal sensory branch of the ulnar nerve. Rotation is not as difficult to control as in the scapholunate interval.

Whipple reviewed the results of arthroscopic treatment of acute scapholunate instability, [47]  grouping patients according to symptom duration and the side-to-side radiographic differences in the scapholunate gap. Approximately 83% of those who had a history of instability for 3 months or less and who had less than 3 mm of side-to-side difference in the scapholunate interval maintained reduction and symptomatic relief, compared with only 53% of patients who had symptoms for more than 3 months and had a scapholunate interval side-to-side difference of more than 3 mm.

Similarly, Osterman et al reported the results of arthroscopic treatment of acute lunotriquetral instability in 20 patients who did not have volar intercalated segmental instability. [48] After an average of 2 years and 8 months, 16 patients had pain relief that was good to excellent. Loss of wrist extension averaged 17°, and loss of flexion averaged 25°. Grip strength improved in 18 patients.

Weiss et al examined the role of arthroscopic debridement alone for the treatment of complete and incomplete intercarpal tears of the wrist. [49] At an average of 27 months after the procedure, 19 of the 29 patients who had a complete tear of the scapholunate ligament and 31 of the 36 who had an incomplete tear had either complete resolution of or a decrease in their symptoms. Twenty-six of the 33 patients who had had a complete tear of the lunotriquetral ligament and all 43 who had had a partial tear had complete resolution of or a decrease in their symptoms. Grip strength improved by an average of 23%.

Arthroscopic debridement

The arthroscopic technique for debridement is straightforward, and the goal is to debride back to stable tissue. To debride the scapholunate ligament, the arthroscope is placed in the 4-5 portal, and the shaver is placed in the 3-4 portal. The lunotriquetral ligament is debrided with the arthroscope in the 3-4 portal and the shaver in the 6-R portal. Because it is difficult to see the lunotriquetral interval from the 3-4 portal, the arthroscope may have to be placed intermittently in the 6-R portal to evaluate the result of the debridement. Arthroscopic debridement of chronic tears is most effective if no carpal collapse exists.

Electrothermal shrinkage may play a role in patients with chronic dynamic carpal instability. Geissler recorded results in 18 patients who underwent electrothermal shrinkage in chronic partial tears of the interosseous ligaments (WB Geissler, unpublished data). The unstable ligament flap is debrided as noted above, and the remaining fibers of the dorsal capsule are then shrunk with the probe (see the image below). Grade II partial tears had a significantly better result than grade III injuries. Follow-up was relatively short (18 months), and the series was small.

Electrothermal shrinkage performed in a patient wi Electrothermal shrinkage performed in a patient with dynamic carpal instability. Careful use of the probe is required to avoid damage to critical structures.

It is important to monitor the temperature of the irrigation fluid as it leaves the outflow portal is. To avoid potential burns, the power of the probe is lowered, and a tourniquet is not used so as to permit the heat to diffuse.

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Treatment of Triangular Fibrocartilage Complex Injuries

Traumatic injuries (class I)

Class IA

Class IA tears or perforations are horizontal tears of the triangular fibrocartilage complex (TFCC) that are usually 1-2 mm wide and located 2-3 mm ulnar to the radial attachment on the sigmoid notch, where the articular disc is thinnest. (See the images below.) Patients usually present with dorsal tenderness at the distal aspect of the ulna, as well as pain with forearm rotation. If conservative treatment fails, arthroscopic debridement to remove the unstable flap is the preferred treatment.

Class IA tear of the triangular fibrocartilage com Class IA tear of the triangular fibrocartilage complex. The probe points at the tear.
Arthroscopic debridement in a class IA tear. The f Arthroscopic debridement in a class IA tear. The flap has been debrided, and the arthroscope is used to smooth the remaining disc.

At surgery, the arthroscope is placed in the 3-4 portal. An appropriately sized banana blade is inserted through the 6-R portal, and the unstable flap is excised. The arthroscope is then transferred to the 6-R portal, and a small-joint punch is inserted through the 3-4 portal to debride the ulnar aspect of the tear.

A small-joint shaver is used to smooth the remaining portion of the articular disc. Care must be taken not to damage the volar and dorsal radioulnar ligaments, which assist in stabilizing the distal radioulnar joint.

Up to one third of the articular disc may be excised safely; the peripheral 2 mm must be maintained to avoid injury to the distal radioulnar joint.

Class IB

Class IB injuries are avulsions of the TFCC from its insertion into the distal aspect of the ulna, with or without an associated ulnar styloid fracture. (See the images below.) These injuries are usually associated with distal radioulnar joint instability. The patient often has tenderness near the 6-U portal, and the pain is reproduced with ulnar deviation and forearm rotation. Arthroscopic examination usually reveals loss of tension of the articular disc, and arthroscopic debridement assists in locating the tear. Hypertrophic synovitis that covers the torn part of disc may be present. Various arthroscopic suturing techniques are described for peripheral ulnar tears.

Class 1B tear, as depicted from the 3-4 portal. Re Class 1B tear, as depicted from the 3-4 portal. Reactive synovitis may cover the tear.
Repair of a class IB tear with the outside-in tech Repair of a class IB tear with the outside-in technique. A small, longitudinal incision incorporates the 6-R portal.
Arthroscopic image of a cannulated needle piercing Arthroscopic image of a cannulated needle piercing the articular disc in a class IB repair.
Arthroscopic view reveals retrieval of the suture Arthroscopic view reveals retrieval of the suture with a small joint grasper.
Sutures placed before being tied in a class IB tea Sutures placed before being tied in a class IB tear.

Whipple et al described an outside-in technique for tears that extend dorsally in which sutures are placed longitudinally to reattach the central cartilage disc to the floor of the fifth and sixth extensor compartments. [50, 51, 52, 53] The arthroscope is usually inserted into the 3-4 portal. Through the 6-R portal, fibrovascular tissue is debrided, and the dorsal margin of the central disc is freshened with a small, motorized shaver. A small longitudinal incision, approximately 15 mm long and incorporating the 6-R portal, is made. The extensor carpi ulnaris retinaculum is then opened, and the tendon is retracted, usually radially.

A curved cannulated needle is inserted through the floor of the extensor carpi ulnaris as vertically as possible in relation to the articular disc. The needle, observed arthroscopically, pierces through the disc. A suture retriever is then placed intra-articularly distal to the articular disc to grasp the suture, as shown above. Then the suture is advanced through the needle, brought through the dorsal aspect of the capsule with the use of the suture retriever's loop, and tied on the floor of the extensor carpi ulnaris sheath with the wrist in supination. Usually, two or three sutures are sufficient to approximate the edges of the tear.

Next, the extensor retinaculum is closed. Kits are commercially available; two 18-gauge needles and sutures are a simpler alternative. Then, 2-0 polydioxanone suture (PDS) is used to repair the disc. A convenient, low-cost, and ideal way to make the suture retriever is to place both ends of a suture (4-0 nylon) through the needle end of an 18-gauge needle and then advance them to the opposite end. The suture is pulled through until only a small loop is left.

If the tear overlies the ulnar styloid process, the injury can generally be treated without disturbing the extensor carpi ulnaris tendon. Under fluoroscopic control, a 1.5-mm drill hole is made obliquely through the base of the ulnar styloid process. [54] A straight needle is used to pass a suture through the drill hole and then distally through the ulnar edge of the disc. The suture is retrieved through a 6-U portal that has been made inside the operative incision and tied around the volar edge of the ulnar styloid process.

Then, the limb is placed in an above-the-elbow cast or a sugar-tong splint in slight supination for 4 weeks, after which a removable or rigid splint is worn for an additional 3 weeks. Physical therapy is then initiated for range of motion and strengthening.

In a technique reported by Ekman et al, [37] the arthroscope is placed in the 4-5 portal, and a Toughy needle is placed in the radiocarpal joint through either the 1-2 or the 3-4 portal. Under direct visualization, the needle is passed through the torn edge of the disc and ligamentous tissue above the ulnar styloid process and then out through the skin. A 2-0 absorbable suture is threaded through the entire needle and anchored at each end with hemostats.

The needle is then brought back into the joint space, passed through the edge of the tear again, and advanced though the soft tissue on the ulnar side of the joint, then 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. Then, blunt dissection is carried out, and under direct visualization from the 4-5 portal, all sutures are pulled back through the skin and out through the single incision. When the skin is closed, the sutures are tied and buried.

Chow developed a technique that involved the use of a wire-loop needle so that the suture can be captured as it is passed intra-articularly. [55] This technique enables reattachment of the TFCC to the capsule of the joint.

In this approach, the arthroscope is usually inserted into the 3-4 portal and assisted by the 6-U portal. Insertion of the repair sutures is guided by a 25-gauge needle without the head so that access can be gained from the outside. The most common sites for suturing are the 4-5 and 6-R portals. To capture the suture, the wire loop is returned inside the straight needle; then the needle is inserted on the distal side of the TFCC with the 25-gauge needle for guidance. (The bevel of the needle should face upward to avoid damaging the articular surface.)

The second straight needle, which contains the suture, is inserted 4-5 mm proximal to the first needle. The bevel should be inserted face down with the sharp-tipped edge pointing upward, which facilitates puncturing the articular disc. From the 6-U portal, a small holder is inserted to assist in passing the suture by holding the free edge of the tear.

When the needle has passed through the articular disc, the wire loop is advanced from the first needle to loop around the second needle. The second needle is gently turned so that the bevel faces upward and engages the wire loop further, which allows it to be pulled to further engage the second needle. Then the suture is passed through the second needle. With a grasper, the suture is held and inserted into the 6-U portal.

The second needle is pulled back gently through the articular disc to avoid cutting the suture, and the suture is retrieved via the 6-U portal by gently tugging the grasper. With a hemostat, the end of the suture is secured to the second needle. The wire loop is retracted and the suture is pulled back through the 6-U portal and out of the dorsal aspect of the wrist, where the suture is then secured.

Under arthroscopic visualization, a small incision is made between the sutures. The joint capsule is then bluntly dissected with a hemostat. Care should be taken to avoid trapping any tendons or puncturing the joint capsule. A probe is inserted into the incision and then looped around the top and bottom of the suture so that it can be brought through the center of the incision.

The suture is tacked down for future tying with hemostats. A surgeon's knot is recommended for the first knot, followed by insertion of the probe. To ensure that the suture is tight and that no tissue or tendons are caught in it, tying should be performed under arthroscopic visualization.

An arthroscopic knotless anchor approach to repair of class IB TFCC injuries has been reported to yield and good functional and occupational results with a low complication rate. [56]

Chen et al reviewed 59 wrists treated with the outside-in repair and concluded that arthroscopy resulted in correct diagnosis and treatment of peripheral TFCC tears. [57]

Edgerton et al used an unusual all-inside technique for traumatic repairs that showed good results; further study is required. [58]

Naroura et al described four volar arthroscopic portals using an inside-out approach with incisions mirroring the dorsal portals. The portals were studied via a radial radiocarpal approach, an ulnar radiocarpal approach, a radial midcarpal approach, and an ulnar midcarpal approach. The authors concluded that these were easy and safe to perform and should be useful in ligament or bony intracarpal repairs. [59]

Class IC

Class IC injuries consist of peripheral tears of the TFCC. Usually this injury involves the distal attachment of the lunate or the triquetrum and results in ulnocarpal instability. TFCC peripheral tears are also characterized by palmar translocation of the ulnar aspect of the carpus in relation to the radius or the ulnar head, or both. The patient likely has palmar tenderness and pain over the pisiform bone, as well as locking on the ulnar side when performing a firm grip.

If wrist instability is not present in a class IC lesion, treatment consists of immobilization through casting for a period of 6 weeks. Surgical intervention is considered when immobilization is not successful. Other treatment options are controversial and include arthroscopic debridement, repair, or, in chronic lesions, possible electrothermal shrinkage.

For surgical repair of class IC injuries, an incision is made over the extensor carpi ulnaris tendon, much as in a type IB Whipple repair. A needle is passed through the tear of the ulnar carpal ligament and observed arthroscopically. Then, a needle suture retriever is placed through the articular disc to grasp the suture, which repairs the tear of the ulnar carpal ligament back to the articular disc.

The patient is immobilized postoperatively, in a fashion resembling the immobilization used for Palmer type IB tears.

Class ID

Class ID TFCC injuries are severe and include traumatic avulsion of the articular disc from the area of attachment on the sigmoid notch. (See the images below.) These injuries are usually associated with a fracture in the area of the sigmoid notch. Patients who have this type of injury present with diffuse tenderness along the entire ulnar aspect of the wrist. The patient may also have wrist joint hemarthrosis.

Class ID tear. Avulsion of the disc from the sigmo Class ID tear. Avulsion of the disc from the sigmoid notch is depicted.
Arthroscopic image of the rim of the sigmoid notch Arthroscopic image of the rim of the sigmoid notch, which is debrided to a bleeding bone bed before reattachment of the disc.

Historically, 6 weeks of immobilization was recommended, which allowed the injury to heal as the articular disc remained intact. [46] However, Sagerman et al suggested arthroscopic reattachment for the repair of class ID TFCC injuries instead. [60]

The osseous rim of the sigmoid notch is debrided to form a bleeding cancellous bone bed. It is important not to take too much bone; otherwise, the articular disc does not reach back for repair. The radial edge of the horizontal disc is then reattached to the bone. A cannula is placed into the 6-U portal, and the arthroscope is placed in the 3-4 portal. A 0.062-in. K-wire is placed through the 6-U cannula, and three drill holes are placed from the sigmoid notch across the radius.

Double-armed meniscal repair needles are inserted into the 6-U cannula through the articular disc and across the radius in the previously drilled holes. A grasper that is positioned through the 6-R portal helps to guide the needle through the disc and into the drill holes. Two sutures (2-0 Ethibond [Ethicon, Somerville, NJ] is recommended) are placed through the central drill hole. To tie the sutures directly over the radius, a small incision is made.

Immobilization of the wrist for 4 weeks is achieved by an above-the-elbow cast, followed by an additional 4 weeks in a removable below-the-elbow splint.

Fellinger et al developed a technique that involves using a meniscal T-shaped suture anchor to repair radial peripheral tears. [61] It must be noted that the lack of blood supply to the radial side of the disc has led to controversy over repairing radial tears.

Degenerative lesions (class II)

A class IIA lesion consists of the wear of the horizontal portion of the TFCC distally and/or proximally. Class IIB lesions consist of wear of the horizontal portion of the articular disc and chondromalacia of the lunate, ulna, or both. If ulnar-plus syndrome is present, then ulnar shortening is recommended because this decreases the pressure, or load, of the ulnar head on the lunate. A class IIC lesion is described as a perforation of the TFCC and chondromalacia of the lunate and/or the ulna (see the image below).

Class IIC tear of the triangular fibrocartilage co Class IIC tear of the triangular fibrocartilage complex. Note the chondromalacia of the ulna.

In addition to these characteristics, if the lunotriquetral ligament is also torn, then the lesion is classified as class IID. A class IIE lesion includes the previously mentioned characteristics, the torn lunotriquetral ligament, and ulnocarpal arthritis. If the patient has ulnar-plus syndrome, the symptomatic lesions of class IIC, class IID, and class IIE are treated by arthroscopic debridement and ulnar shortening.

The ulnar head may be shortened arthroscopically or with an open ulnar shortening osteotomy. If the arthroscope is used, it is inserted in the 3-4 portal, and a burr is placed in the 6-R portal. Resection of the ulna head occurs through the defect of the torn articular disc. To gain access to the peripheral margins of the ulnar head, the wrist is pronated and supinated. To improve access to the ulnar head, the burr may be placed proximal to the articular disc through the distal radioulnar joint portal.

The most commonly asked question in relation to the wafer procedure is how much bone must be resected. [62, 63] Under normal conditions, resect less than 4 mm of bone. The resection should be monitored under fluoroscopy because arthroscopic magnification makes it more difficult to estimate the amount of bone that is excised. Care must be taken not to remove too much articular cartilage from the distal radioulnar joint. Also, the stability of the distal radioulnar joint should be preserved by not removing the origins of the radioulnar and ulnocarpal ligaments.

Nagle recommended the use of a laser to resect the ulnar head to the osseous section. [64, 65] Strong consideration should be given to open ulnar shortening when lunotriquetral instability is present.

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Arthroscopic Ganglionectomy

Osterman et al and others reported the arthroscopic removal of dorsal ganglia as excellent, with several advantages relative to open excision. [66, 26, 67] When the ganglionectomy is performed with the arthroscope, less scarring and cosmetic disfiguration occur, and there is faster postoperative improvement in ROM. Also, the recurrence rate after removing the ganglia appears to be low. The scapholunate ligament, which often causes the formation of dorsal carpal ganglion cysts, can be examined closely with the arthroscope.

The arthroscope is initially placed in the 6-R portal; then a needle is positioned through the ganglion and enters the radiocarpal space. The needle enters the joint rather obliquely, as the ganglion location is approximately 1 cm distal to the normal location of the 3-4 portal. A shaver is then placed through this modified portal to debride a defect in the dorsal aspect of the capsule, which is opposite the scapholunate ligament. The hole is enlarged dorsally and distally because the scapholunate ligament attaches to the dorsal aspect of the capsule. The stalk of the dorsal carpal ganglion cyst is also located in this area.

To ensure that a full-thickness debridement of the capsule has been performed, the extensor carpi radialis brevis tendon should be visualized through the dorsal aspect of the capsule. After debridement of the ganglion and stalk, ganglion cyst palpation reveals a sudden blush and release of the cyst. (See the image below.)

Radiocarpal view after arthroscopic removal of the Radiocarpal view after arthroscopic removal of the ganglion stalk.

Postoperatively, the limb is covered with a soft bulky dressing, and very little hand therapy is required. Patients are encouraged to perform ROM exercises beginning the following day.

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Treatment of Fractures of Distal Aspect of Radius

The treatment of displaced fractures of the distal aspect of the radius includes articular inclination, restoration of radial length, and anatomic or nearly anatomic joint congruity. [68, 69, 70, 71, 72, 73, 74] Over the years, 2 mm has been well established as the critical threshold tolerance for distal radial intra-articular incongruity. [43] However, other investigators have reported that the critical tolerance may be as low as 1 mm. [75, 76, 77, 78, 79]

In situations where closed reduction can be achieved but not maintained, internal fixation should be considered. Arthroscopic-assisted treatment is optimal 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 rim (Barton-type) fractures, and three- or four-part intra-articular fractures of the distal radius. [25, 75, 79, 80, 81, 82, 83] Early in the learning curve when a surgeon is considering arthroscopic-assisted fixation, an excellent case is an isolated radial styloid fracture without comminution.

Intra-articular and extra-articular fractures have a high prevalence of associated injuries of the scapholunate and lunotriquetral ligaments, as well as of the TFCC. [25, 80, 82, 84, 85, 86, 87, 88, 89, 90, 91, 92] The more severe injuries can be diagnosed indirectly on the basis of clinical examination or of abnormalities that are observed on radiographs. Arthroscopy that is performed at the time of fracture treatment increases the recognition of these injuries, as well as the identification of their extent and degree of instability. [80, 82, 84, 85, 87]

Surgical technique

Patients with displaced, unstable intra-articular fractures of the distal radius are taken to surgery, usually within 2-7 days post injury. A delay of at least 48-72 hours after injury appears to minimize bleeding from the fracture site during the arthroscopy. [82]

Prepare the surgical suite in such a way that both fluoroscopy and arthroscopy can be performed. The wrist may be suspended vertically in a traction tower or suspended horizontally, with weights at the end of a hand table. The traction tower allows the wrist to be manipulated with constant traction. Many surgeons are more comfortable with the anatomy of the wrist in the horizontal position, which also allows the use of fluoroscopy to help monitor the reduction.

A compressive bandage that is wrapped around the forearm helps prevent fluid extravasation during arthroscopy. The wrist is suspended in the traction tower with approximately 10 lb (4.5 kg) of traction. Inflow is established through the 6-U portal. A 2.7-mm 30° small-joint arthroscope is inserted through the 3-4 portal. The arthroscopic cannula provides the outflow. The 4-5 portal is the primary working portal. Additional portals are established if needed. Hematoma and debris are removed with the use of lavage, suction, mini-grasping forceps, and a 2.9-mm shaver until optimal visualization occurs (see the image below).

Arthroscopic view demonstrating the articular step Arthroscopic view demonstrating the articular step-off in a distal radius fracture. Hematoma and debris are removed for optimal visualization.

Fluoroscopy is used to select the K-wire entry site. A portal-sized incision can be made over the area of wire insertion. Only the skin is incised. A 14-gauge needle or a drill guide tap sleeve is placed over the K-wire; the needle is placed directly on bone to maximize soft-tissue protection during drilling. As with the site of entry, the K-wire within the fragment can be selected and monitored fluoroscopically. Additional pointed instruments, such as a Steinmann pin, a pointed bone awl, dental picks and elevators, or pointed reduction forceps, can be helpful in achieving, maintaining, or even compressing the fracture after reduction. Small probes can be helpful to elevate fracture fragments under direct arthroscopic visualization.

When an acceptable reduction is attained, K-wires or screws can provide additional security (see the image below). These wires provide splinting but not compression and may act as guide wires to place cannulated screws. However, headless cannulated screws are preferred, in that they provide excellent fixation and are placed entirely within the bone. In this manner, ROM therapy may be initiated earlier with the headless cannulated screws than with the use of K-wires, and the patient is placed in a removable wrist splint.

Radiograph of a wrist after arthroscopic-assisted Radiograph of a wrist after arthroscopic-assisted pinning of an intra-articular distal radius fracture

If a large defect is discovered, the appropriate open approach should be used, and bone grafting (either autogenous or bone-graft substitute) is performed. Cancellous bone graft can be inserted into the barrel of a 10-mm syringe and compressed with the plunger (AE Freeland, WB Geissler, unpublished data). The plunger is removed, the barrel turned upside down, and the compressed bone graft pushed out with the assistance of a needle. Compressed cancellous bone graft provides increased structural support and helps fracture healing when a defect is present. [93]

Alternatively, injectable bone graft substitutes, such as Norian (Synthes Medical Device Co, Solothurn, Switzerland) or MIIG (Wright Medical Technology, Memphis, TN), freeze-dried cancellous bone chips, or calcium sulfate pellets (OsteoSet; Wright Medical Technology, Memphis, TN) may be used.

The K-wires, when used, are left in place for 4-6 weeks. The skin tension around the wires is routinely incised, and the K-wire can be cut beneath the skin or allowed to protrude. The fracture is protected for at least 4 weeks with either a cast or fracture-brace. Neither the cast nor the fracture-brace should extend distal to the distal palmar crease or block excursion of the metacarpophalangeal joints. This allows for concurrent finger rehabilitation while the fracture of the wrist is protected. A second 4-week period is focused on recovery of motion of the wrist and forearm. Then a third 4-week period is used for progressive strengthening and conditioning.

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Treatment of Scaphoid Fractures

The scaphoid is the carpal bone most likely to sustain a fracture and accounts for 70% of carpal fractures. This injury typically occurs in young men aged 15-30 years. Scaphoid fractures are also common athletic injuries, particularly in basketball and football, sports that place the athlete at particular risk for fracture because aggressive play frequently causes impact injuries to the wrist. [94]

Acute nondisplaced scaphoid fractures have traditionally been managed with cast immobilization. The duration of such immobilization varies dramatically according to the fracture site: A fracture of the scaphoid tubercle may heal within a period of approximately 6 weeks, whereas a fracture of the proximal third of the scaphoid may take 3 months or longer to heal.

Although cast immobilization may be successful in 90% of cases, the cost may be high to the patient, who may not be able to tolerate a lengthy cast immobilization, which can lead to muscle atrophy, possible joint contracture, tissue osteopenia, and potential financial hardship. In addition, the athlete or worker may be inactive for 3 months or longer as the fracture heals.

Several authors have advocated arthroscopically or percutaneously assisted fixation of scaphoid fractures because of the potential problems associated with cast immobilization in the management of scaphoid fractures. These techniques offer a middle ground between the traditional recommendation of cast immobilization for nondisplaced fractures and open reduction for displaced scaphoid fractures.

The application of arthroscopically assisted fixation techniques in the management of scaphoid fractures offers many advantages over conventional techniques because they reduce exposure and minimize soft-tissue dissection that may result in a potential loss of vascularity to the fracture fragments. Arthroscopically assisted reduction also has the following benefits:

  • Avoiding the division of the important radioscaphocapitate ligament from the volar capsule, which would otherwise require subsequent repair and healing
  • Avoiding potential painful scarring over the volar radial aspect of the wrist
  • Detecting and managing any associated intracarpal soft-tissue injury that may occur with the scaphoid fracture

The goal of internal stabilization of scaphoid fractures is to provide secure fixation to allow early motion until solid union has been achieved. Surgical indications for arthroscopic fixation of scaphoid fractures are specific and include treatment of the following [95] :

  • Nondisplaced unstable fractures
  • Minimally displaced but reducible fractures
  • Delayed presentation
  • Proximal pole fractures
  • Fibrous nonunions without avascular necrosis
  • Scaphoid ipsilateral displaced distal radius fractures
  • Scaphoid fractures with associated ligamentous injury

Various arthroscopic-assisted and percutaneous techniques for scaphoid fractures have been described in the literature. These include the volar approach, popularized by Haddad et al [96] ; the use of the Herbert-Whipple jig as described by Whipple [47, 53] ; and, subsequently, the dorsal approach as popularized by Slade. [97]

In general, all of these techniques involve the use of a small amount of wrist arthroscopy and a larger amount of imaging under fluoroscopy. Nondisplaced or slightly displaced fractures without comminution are particularly amenable to any of these techniques. Significantly displaced fractures in which there is marked deformity of the lunate, particularly in the chronic situation, are best managed by means of open reduction.

Slade popularized the dorsal approach for arthroscopic-assisted fixation of scaphoid fractures. [97] This technique has become prevalent because it is simple to use for further arthroscopic evaluation and further reduction of the fracture.

The patient is positioned supine on the arm table with the arm extended. Under fluoroscopy, the wrist is flexed and pronated until the proximal and distal pole of the scaphoid are aligned. The wrist is flexed approximately 45°, which places the scaphoid in a 90° flexed position (see the image below). With this technique, the scaphoid should appear as a cylinder (ring sign).

Before the scaphoid is pinned, the wrist is flexed Before the scaphoid is pinned, the wrist is flexed at 45 degrees, which places the scaphoid in 90 degrees flexion.

A 14-gauge needle is used as a drill guide for a .045-in. Kirschner guide wire. Under fluoroscopy, the needle is placed in the center of the ring and aligned parallel to the axis of the fluoroscopy unit. Once this position is obtained, a needle is inserted into the proximal pole of the scaphoid. (It is essential that the needle be in the center of the fluoroscopic ring sign.) The guide wire is then driven along the central axis of the scaphoid until the distal end is in contact with the distal scaphoid cortex.

A second guide wire is placed parallel to the first in such a way that its tip touches the cortex of the proximal pole. The difference in length of the two wires is the resulting length of the scaphoid. Because there is a tendency to insert a screw too long, at this point, 4 mm is subtracted from the length of the two wires, which provides the length of the scaphoid.

The primary guide wire is advanced volarly through the trapezium along the radial side of the base of the thumb. Then, the guide wire is further advanced volarly until the proximal end of the pin is flush with the proximal end of the scaphoid. At this point, the wrist can be extended. If the wrist is extended before this time, it can bend the guide pin.

With the wrist extended, the placement of the guide wire in the scaphoid is evaluated under fluoroscopy in the anteroposterior, oblique, and lateral planes. At this point, the wrist is suspended in the traction tower. The fracture of the wrist is visualized best with the arthroscope in the radial midcarpal portal.

If the reduction of the scaphoid fracture is not anatomic, K-wire joysticks may be placed in the dorsum of the scaphoid into the proximal and distal fragments. The previously placed guide wire continues to be advanced volarly until it is only in the distal pole of the scaphoid. The joysticks are then used to anatomically reduce the fracture as observed arthroscopically, and the guide pin is advanced back from the volar-to-dorsal direction into the proximal pole of the scaphoid.

A fracture of the proximal pole of the scaphoid is best visualized with the arthroscope in the ulnar midcarpal portal. Once anatomic reduction of the scaphoid is confirmed arthroscopically, the arthroscope is placed in the 3-4 portal. The radiocarpal space is then evaluated for any associated soft-tissue injuries of the interosseous ligaments or TFCC. If associated tears are identified, they can be managed at this time.

Once anatomic reduction of the scaphoid is noted arthroscopically and arthroscopic management of any other associated soft-tissue lesions has been performed, the wrist is taken out of traction and flexed. The guide wire is advanced dorsally so that it protrudes outside the skin. However, the guide wire is also left protruding from the volar aspect of the hand such that in the event it bends or breaks, the guide wire can be easily removed from either the volar or dorsal aspect.

A small incision is made over the guide wire on the dorsal aspect of the wrist. Blunt dissection is continued with the hemostat down to the capsule around the guide pin. With the wrist maintained in flexed position, the scaphoid is reamed with the Acutrak hand reamer (Acumed LLC, Hillsboro, OR).

In Slade's technique, [97] the scaphoid is reamed no closer than 2 mm from the cortex of the distal pole of the scaphoid (see the image below). This is crucial because overreaming the scaphoid prevents secure fixation of the fracture fragments. At this point, placing a secondary guide pin is important to help prevent rotation of the fracture fragment when the scaphoid is drilled and when the screw is eventually placed.

Fluoroscopic image demonstrates reaming of the sca Fluoroscopic image demonstrates reaming of the scaphoid in a proximal-to-distal fashion after arthroscopic reduction and percutaneous pinning.

The Acutrak headless screw is inserted over the guide wire to the depth that was previously reamed. Ensuring that the screw has not advanced to the far cortex is important because otherwise, fracture distraction may occur. Once the screw is placed, the guide wires are removed. The position of the screw is checked under fluoroscopy to confirm its central location within the scaphoid (see the images below).

Anteroposterior radiograph after reduction and fix Anteroposterior radiograph after reduction and fixation with a headless screw.
Lateral radiograph after reduction and fixation wi Lateral radiograph after reduction and fixation with a headless screw.
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Complications

The benefits of wrist arthroscopy must be compared with the possible complications, which can occur with any surgical procedure. However, complications of arthroscopy are rare in general, and the wrist is no exception. [98] Potential complications that have been reported in the wrist include the following:

  • Infections
  • Neuromas
  • Tendon injuries
  • Reflex sympathetic dystrophy (RSD)
  • Dorsal skin slough
  • Tourniquet neurapraxia
  • Compartment syndromes
  • Finger-joint injury or skin slough from finger traps

Adequate precautions while performing arthroscopy can prevent the majority of these complications, which are rare and can usually be prevented through proper technique. [99]  To this end, the following measures are important to keep in mind:

  • Remember that millimeters make a difference in the wrist with regard to portal placement
  • Be thoroughly familiar with the anatomic landmarks in the portal location
  • Place a needle in the proposed portal location before making a skin incision
  • Prevent damage to the articular cartilage by using a blunt trocar rather than a sharp one when cannulas are introduced in the wrist
  • Remember both the volar and radial tilt of the distal radius when the cannulas are introduced
  • Use separate inflow and outflow portals to limit fluid extravasation into the soft tissues
  • Decrease the risk of possible compartment syndrome by using physiologic solutions such as lactated Ringer solution to allow absorption of fluid in the soft tissues
  • Always insert K-wires through soft-tissue protectors to limit potential damage to the numerous sensory cutaneous nerves in the vicinity of the wrist
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