David J. Slutsky
BACKGROUND
Since its inception, wrist arthroscopy has continued to evolve. The initial emphasis on viewing the wrist from the dorsal aspect arose from the relative lack of neurovascular structures as well as the familiarity of most surgeons with dorsal approaches to the radiocarpal joint.
Anatomic studies provided a better understanding of both the interosseous ligaments as well as carpal kinematics, which led to the development of midcarpal arthroscopy.
Innovative surgeons continue to push the envelope through the development of techniques for treating intracarpal pathology, which in turn has culminated in a plethora of new accessory portals.
ANATOMY
The standard portals for wrist arthroscopy are dorsal (FIG 1A–C). This is in part due to the relative lack of neurovascular structures on the dorsum of the wrist as well as the initial emphasis on assessing the volar wrist ligaments. The dorsal portals that allow access to the radiocarpal joint are so named in relation to the tendons of the dorsal extensor compartments.
The 1–2 portal lies between the first extensor compartment tendons, which include the extensor pollicis brevis and the abductor pollicis longus, and the second extensor compartment, which contains the extensor carpi radialis brevis and longus (FIG 1D).
The 3–4 portal is named for the interval between the third dorsal extensor compartment, which contains the extensor pollicis longus tendon, and the fourth extensor compartment, which contains the extensor digitorum communis (EDC) tendons.
The 4–5 portal is located between the EDC and the extensor digiti minimi (EDM).
The 6R portal is located on the radial side of the extensor carpi ulnaris (ECU) tendon; the 6U portal is located on the ulnar side.
The midcarpal joint is assessed through two portals, which allows triangulation of the arthroscope and the instrumentation.
The midcarpal radial portal is located 1 cm distal to the 3–4 portal and is bounded radially by the extensor carpi radialis brevis and ulnarly by the EDC.
The midcarpal ulnar portal is similarly located 1 to 2 cm distal to the 4–5 portal and is bounded by the EDC and the EDM.
The triquetrohamate portal enters the midcarpal joint at the level of the triquetrohamate joint ulnar to the ECU tendon. The entry site is both ulnar and distal to the midcarpal ulnar portal. Branches of the dorsal cutaneous branch of the ulnar nerve are most at risk (FIG 2A).
The dorsal radioulnar joint portal lies between the ECU and the EDM tendons. Transverse branches of the dorsal cutaneous branch of the ulnar nerve are the only sensory nerves in proximity to the dorsal radioulnar portal, at a mean of 17.5 mm distally (range 10–20 mm) (FIG 2B,C).
FIG 1 • Dorsal portal anatomy. A. Cadaver dissection of the dorsal aspect of a left wrist demonstrating the relative positions of the dorsoradial portals. EDC, extensor digitorum communis; EPL, extensor pollicis longus; SRN, superficial radial nerve; *, tubercle of Lister. B. Relative positions of the dorsoulnar portals. EDM, extensor digiti minimi; DCBUN, dorsal cutaneous branch of the ulnar nerve. C.Positions of the 6R and 6U portals. D. Branches of the superficial radial nerve (SRN). SR1, minor dorsal branch; SR2, major dorsal branch; SR3, major palmar branch. (From Slutsky DJ. Wrist arthroscopy portals. In Slutsky DJ, Nagle DJ, eds. Techniques in Hand and Wrist Arthroscopy. Philadelphia: Elsevier, 2007.)
FIG 2 • A. Ulnar aspect of a left wrist demonstrating the relative positions of the triquetrohamate (T-H) portal and the 6U portal. DCBUN, dorsal cutaneous branch of the ulnar nerve; UN, ulnar nerve. B,C.Dorsal distal radioulnar joint (DRUJ) portal anatomy. B. Relative position of the proximal (PDRUJ) and distal (DDRUJ) portals. C. Close-up with the dorsal capsule removed demonstrating the position of the needles in relation to the dorsal radioulnar ligament (*). AD, articular disc; UC, ulnocarpal joint; UH, ulnar head. D,E. Volar DRUJ portals. D. Volar aspect of a left wrist demonstrating the relative positions of the volar ulnar (VU) and volar DRUJ (VDR) portals in relation to the ulnar nerve (*) and ulnar artery (UA). FDS, flexor digitorum sublimis; FCU, flexor carpi ulnaris. E. Close-up view after the volar capsule is removed showing position of needles in relation to the volar radioulnar ligament (*). Tr, triquetrum; UH, ulnar head. (From Slutsky DJ. Wrist arthroscopy portals. In Slutsky DJ, Nagle DJ, eds. Techniques in Hand and Wrist Arthroscopy. Philadelphia: Elsevier, 2007.)
There are two volar portals that can be used to access the radiocarpal joint.
The volar radial portal is accessed through the floor of the flexor carpi radialis tendon sheath at the level of the proximal wrist crease.5,7,9
Anatomic studies revealed that there is a safe zone free of any neurovascular structures, equal to the width of the flexor carpi radialis tendon plus at least 3 mm in all directions.
The volar aspect of the midcarpal joint can be accessed through the volar radial midcarpal portal. The same skin incision is used but the capsular entry point is about 1 cm distal.
The volar ulnar portal is located underneath the ulnar border of the flexor tendons at the level of the proximal wrist crease.6
The volar aspect of the distal radioulnar joint (DRUJ) can be accessed through the volar distal radioulnar portal using the same skin incision, but the capsular entry point for the volar distal radioulnar portal lies 5 mm to 1 cm proximal to the ulnocarpal entry point (FIG 2D,E).
AUTHOR'S EXPERIENCE
The volar radial portal has been used in 111 patients since 1998.4
Additional pathology was evident in 61 of the patients that was not visible from any standard dorsal portals. This included 1 case of hypertrophic synovitis of the dorsal capsule (FIG 3A), 1 patient with an avulsion of the radioscapholunate ligament that exposed the volar scapholunate cleft (FIG 3B), 2 patients with tears restricted to the palmar region of the scapholunate interosseous ligament (SLIL), and 57 patients with tears of the dorsal radiocarpal ligament (DRCL). In 16 patients an isolated DRCL tear alone was responsible for chronic dorsal wrist pain (FIG 3C,D).
The midcarpal joint was accessed from the volar radial portal in three cases. In one patient with Preiser disease, the use of the volar radial midcarpal portal allowed a more complete assessment of the distal articular surface of the scaphoid. Another patient had unrecognized chondromalacia of the palmar capitate following a perilunate dislocation (FIG 3E). The volar radial midcarpal portal admirably demonstrated the intact dorsal portion of the SLIL in the patient with the palmar tear (FIG 3F).
FIG 3 • A. Hypertrophic synovitis (*) of the dorsal capsule in a case of Presier disease as seen through the volar radial portal. B. Radioscapholunate ligament avulsion. Note unmasking of the palmar cleft (*) between the scaphoid and lunate. SLIL, scapholunate interosseous ligament; RSL, radioscapholunate ligament. C,D. Volar radial portal view. C. Normal dorsal radiocarpal ligament. Hook probe is inserted through the 3–4 portal. SLIL, scapholunate interosseous ligament; DRCL, dorsal radiocarpal ligament. D. DRCL tear (*). Hook probe inserted through the 3–4 portal. Volar midcarpal portal. E.Chondromalacia of the palmar capitate (C). Probe is in the midcarpal radial portal (MCR). L, lunate. F. Tear of the palmar region of the scapholunate interosseous ligament (SLIL), as viewed from the volar radial midcarpal portal. Note the intact dorsal fibers of the SLIL. S, scaphoid; L, lunate; H, hamate; DC, dorsal capsule. (A,B: From Slutsky DJ. Wrist arthroscopy through a volar radial portal. Arthroscopy 2002;18:624–630, with permission.)
The volar ulnar portal has been used in 61 patients since 1998.8
The ulnar-sided pathology included 21 tears of the lunotriquetral interosseous ligament (LTIL) (FIG 4A), 19 triangular fibrocartilage complex (TFCC) tears, and 2 ulnolunate ligament tears. In one patient a TFCC tear was found to extend into the dorsoulnar ligament (FIG 4B,C). The volar ulnar portal facilitated débridement of the palmar region of the LTIL ligament through the 6R or 6U portals. In three of these patients unrecognized chondromalacia of the palmar aspect of the lunate was identified (FIG 4D), and one patient had chondromalacia of the palmar triquetrum. One patient was found to have a loose body in the ulnocarpal joint (FIG 4E).
FIG 4 • A. Lunotriquetral ligament tear as viewed from the volar ulnar portal. Note the tear of the lunotriquetral ligament (*). T, triquetrum, L, lunate. B,C. Volar ulnar portal view. B. Triangular fibrocartilage (TFC) tear extending into the dorsal radioulnar ligament. Probe inserted through the dorsal 4–5 portal. C. Palpation of the dorsal radioulnar ligament tear with the hook probe. D. Unsuspected region of chondromalacia on palmar surface of the lunate. L, lunate; T, triquetrum. E. View of a loose body (*) in the ulnocarpal joint looking across the joint from the volar radial portal. TFC, triangular fibrocartilage; T, triquetrum. F. View from the palmar distal radioulnar joint portal. The undersurface of the articular disc demonstrates a tear of the triangular fibrocartilage (TFC) along with synovitis (*). G,H. Views from the volar distal radioulnar portal. G. View of the sigmoid notch from the palmar aspect of the wrist. AD, articular disc; DC, dorsal distal radioulnar joint capsule; UH, ulnar head. H. View of an intact foveal attachment. Probe is in the distal dorsal radioulnar joint portal (DDRUJ). PRUL, palmar radioulnar ligament; DRUL, dorsal radioulnar ligament. (B,C: From Slutsky DJ. The use of a volar ulnar portal in wrist arthroscopy. Arthroscopy 2004;20:158–163, with permission.)
The volar aspect of the DRUJ was accessed in eight of these patients to rule out a peripheral TFCC tear. The DRUJ was well visualized, demonstrating an intact articular disc in four and a full-thickness tear with undersurface fibrillation in one (FIG 4F). The foveal attachment of the TFCC was seen to be intact in each case (FIG 4G,H).
NONOPERATIVE MANAGEMENT
In general, wrist arthroscopy is indicated as a diagnostic technique in any patient with persistent wrist pain that has not responded to an appropriate trial of conservative measures:
Nonsteroidal anti-inflammatories and activity modification
Cortisone injection
Wrist arthroscopy is used as an adjuvant procedure for the treatment of acute fractures of the distal radius or scaphoid, or for staging degenerative disorders involving the carpus.
Indications
The indications for the use of the standard dorsal portals are intertwined with the indications for wrist arthroscopy and depend largely on the condition that is being treated.
A typical arthroscopic examination of the wrist will include variable combinations of the 3–4 portal, the 4–5 portal, and the 6R and 6U portals.
The 3–4 and 4–5 portals are the main viewing portals for the radial aspect of the radiocarpal joint and for instrumentation.
The 4–5 and 6R portals are used to access the ulnocarpal joint.
The 6U portal is typically used for outflow.
The volar radial portal is indicated for the evaluation of the DRCL and the palmar portion of the SLIL. The volar radial portal also facilitates arthroscopic reduction of intra-articular fractures of the distal radius fractures by providing a clear view of the dorsal rim fragments.
The volar ulnar portal is indicated for visualizing and débriding palmar tears of the lunotriquetral ligament. It also aids in the repair or débridement of dorsally located TFCC tears since the proximity of the 4–5 and 6R portals makes triangulation of the instruments difficult.
Midcarpal arthroscopy through the dorsal midcarpal portals is essential in making the diagnoses of scapholunate and lunotriquetral instability.
The grading scale reported by Geissler and colleagues2 provides a means for staging the degree of instability and provides an algorithm for treatment.
Midcarpal arthroscopy is likewise employed for the assessment and treatment of chondral lesions of the proximal hamate.
The triquetrohamate joint can also be accessed through another special-use midcarpal portal.1
The volar radial midcarpal portal is occasionally used as an accessory portal for visualizing the palmar aspects of the capitate and hamate in cases of avascular necrosis or osteochondral injury.
This portal facilitates visualization of the palmar aspect of the capitohamate interosseous ligament, which is important in minimizing translational motion and has an essential role in providing stability to the transverse carpal arch.
The volar distal radioulnar portal is useful for assessing the deep foveal attachment of the TFCC, which would normally require an open capsulotomy.
It may be employed if the suspicion of a peripheral TFCC detachment remains despite the absence of any visible TFCC tears through the standard ulnocarpal portals.
The dorsal DRUJ portals may be used in concert with the volar distal radioulnar portal to more completely assess the status of the articular cartilage of the ulnar head and sigmoid notch as well as for instrumentation.
The number of conditions amenable to arthroscopic treatment continues to grow. Many arthroscopic procedures are now common, while others await clinical validation. Table 1 provides a list of the more standard procedures.
Contraindications
Contraindications to the use of dorsal or volar portals would include marked swelling, which distorts the topographic anatomy; large capsular tears, which might lead to extravasation of irrigation fluid; neurovascular compromise; bleeding disorders; or infection.
Unfamiliarity with the regional anatomy is a relative contraindication.
SURGICAL MANAGEMENT
It is useful to have a systematic approach to viewing the wrist.
The structures that should be visualized as a part of a standard examination include the radius articular surface; the proximal scaphoid, lunate, and triquetrum; the SLIL and LTIL, both palmar and dorsal; the radioscaphocapitate ligament; the long radiolunate ligament; the radioscapholunate ligament; the ulnolunate ligament; the ulnotriquetral ligament; the articular disc; and the radial and peripheral TFCC attachments.
It is my practice to establish the dorsal portals first but then to start the arthroscopic examination with the volar radial portal to visualize the palmar SLIL and the DRCL ligament to minimize any error from iatrogenic trauma to the dorsal capsular structures.
In patients with ulnar-sided wrist pain, the volar ulnar portal is used to assess the palmar LTIL and dorsal radioulnar ligament, the region of the extensor carpi ulnaris subsheath, and the radial TFCC attachment.
The scope is then inserted in the 3–4 portal followed by various combinations of the 4–5 portal and 6R portal. The 6U portal is mostly used for outflow, but it may be used for instrumentation when débriding palmar LTIL tears.
Midcarpal arthroscopy is then performed to probe the SLIL and LTIL joint spaces for instability, the capitohamate interosseous ligament, and to look for chondral lesions on the proximal capitate and hamate and loose bodies (FIG 5).
The special-use portals such as the dorsal and volar DRUJ portals and the 1–2 portal are used as needed.
Preoperative Planning
A 2.7-mm, 30-degree-angled scope along with a camera attachment is used.
Table 2 describes the typical field of view as seen through a 2.7-mm arthroscope under ideal conditions.1,4
A 1.9-mm scope is sometimes beneficial, especially for evaluation of the DRUJ.
A fiberoptic light source, video monitor, and printer have become the standard of care.
Digital systems allow direct writing to a CD and superior video quality as compared to analog cameras.
A 3-mm hook probe is needed for palpation of intracarpal structures.
FIG 5 • Chondromalacia (*) on the proximal pole of the hamate (H). C, capitate; L, lunate; T, triquetrum.
A motorized shaver or diathermy unit such as the Oratec probe (Smith & Nephew, NY) is useful for débridement.
Ancillary equipment is largely procedure-dependent.
A motorized 2.9-mm burr is needed for bony resection.
There are a variety of commercially available suture repair kits, including the TFCC repair kit by Linvatec (Conmed–Linvatec Corporation, Largo, FL). Ligament repairs can also be facilitated by use of a Tuohy needle, which is generally found in any anesthesia cart.
Positioning
The patient is positioned supine on the operating table with the involved arm abducted on an arm table.
A tourniquet is placed as far proximal on the arm as feasible.
Traction is useful:
A shoulder holder along with 5-to 10-lb sand bags attached to an arm sling
A commercially available traction tower such as the Linvatec tower (Conmed–Linvatec Corporation, Utica, NY) or the ARC traction tower (Arc Surgical LLC, Hillsboro, OR)
For the dorsal portals the surgeon faces the dorsum of the wrist and is seated by the patient's head. For the volar portals the surgeon faces the palm and is seated in the patient's axillary region.
Approach
Portals are established by palpating and identifying anatomic landmarks and then inserting a 22-gauge needle into the joint space. The joint is then injected with 5 cc of saline. The ability to draw the saline back into the syringe serves as evidence that the needle is in the joint.
Shallow incisions avoid injury to sensory nerve branches and tendons. Soft tissues are dissected using a blunt mosquito clamp or a pair of small curved scissors. The dorsal capsule is pierced with these same instruments, providing access to the joint.
A blunt trocar is used to introduce the scope cannula, which will house the scope and the inflow.
Routinely, an 18-gauge needle is placed in the 6U portal for outflow.
Synovitis, fractures, ligament tears, and a tight wrist joint may limit the field of view and necessitate the use of more portals to adequately assess the entire wrist.
TECHNIQUS
3–4 PORTAL
The concavity overlying the lunate between the extensor pollicis longus and the EDC is located just distal to the tubercle of Lister, in line with the second web space.
The radiocarpal joint is identified with a 22-gauge needle that is inserted 10 degrees palmar to account for the volar inclination of the radius.
The vascular tuft of the radioscapholunate ligament is directly in line with this portal. Superior to the radioscapholunate ligament is the membranous portion of the SLIL.
By rotating the scope dorsally while looking in an ulnar direction, the insertion of the dorsal capsule onto the dorsal aspect of the SLIL can often be visualized. This is a common origin for the stalk of a dorsal ganglion.
The radioscapholunate ligament and the long radiolunate ligament are radial to the portal and can be probed with a hook in the 4–5 portal.
The LTIL, TFCC, and ulnolunate ligament are ulnar to the portal.
4–5 PORTAL
The interval for the 4–5 portal is identified with the 22gauge needle between the EDC and EDM, in line with the ring metacarpal.
Because of the normal radial inclination of the distal radius, this portal lies slightly proximal and about 1 cm ulnar to the 3–4 portal.
Care must be taken when inserting the scope since the LTIL lies directly ahead of this portal.
One encounters the ulnar half of the lunate when moving the scope radially, and the oblique surface of the triquetrum in a superior and ulnar direction.
The LTIL is seen obliquely from this portal and is often difficult to differentiate from the carpal bones without probing, unless a tear is present.
The ulnolunate ligament and the ulnotriquetral ligament can be seen on the far end of the joint.
Proximally, the radial insertion of the TFCC blends imperceptibly with the sigmoid notch of the radius, but it can be palpated with a hook probe in either the 3–4 or 6R portal.
The peripheral insertion of the TFCC slopes upward into the ulnar capsule. Peripheral TFCC tears are often located ulnarly and dorsally.
The palmar radioulnar ligament can be probed and visualized (especially if torn), but the dorsal radioulnar ligament is poorly seen.
The pisotriquetral recess can sometimes be identified by a small tuft of protruding synovium and when probed may yield views of the articular facet of the pisiform.
6R AND 6U PORTALS
The 6R portal is identified on the radial side of the ECU tendon, just distal to the ulnar head.
The scope should be angled 10 degrees proximally to avoid hitting the triquetrum. The TFCC is immediately below the entry site.
The LTIL is located radially and superiorly, whereas the ulnar capsule is immediately adjacent to the scope.
The 6U portal is found on the ulnar side of the ECU tendon. Angling the needle distally and ulnar deviation of the wrist helps avoid running into the triquetrum.
This portal can be used to view the dorsal rim of the TFCC or for instrumentation when débriding the palmar LTIL.
1–2 PORTAL
The relevant landmarks in the snuff box are palpated and outlined, including the distal edge of the radial styloid, the abductor pollicis longus, extensor pollicis brevis, and extensor pollicis longus tendons, and the radial artery in the snuff box.
To minimize the risk of injury to branches of the superficial radial nerve and the radial artery, the 1–2 portal should be no more than 4.5 mm dorsal to the first extensor compartment and within 4.5 mm of the radial styloid (TECH FIG 1).10
A blunt trocar and cannula are inserted with the wrist in ulnar deviation to minimize damage to the proximal scaphoid.
TECH FIG 1 • Landmarks for the 1–2 portal. A. Cadaver dissection demonstrating the placement of the 1–2 portal. SR, superficial radial nerve branches; EPL, extensor pollicis longus; EPB, extensor pollicis brevis; APL, abductor pollicis longus. B. Surface landmarks for 1–2 portal. S, scaphoid; ECRL/B, extensor carpi radialis longus and brevis. C. Superimposed intra-articular field of view. (From Slutsky DJ. Wrist arthroscopy portals. In Slutsky DJ, Nagle DJ, eds. Techniques in Hand and Wrist Arthroscopy. Philadelphia: Elsevier, 2007.)
MIDCARPAL RADIAL PORTAL
The midcarpal radial portal is found 1 cm distal to the 3–4 portal.
Flexing the wrist and firm thumb pressure helps identify the soft spot between the distal pole of the scaphoid and the proximal capitate.
The scaphotrapezial trapezoidal joint lies radially and can be seen by rotating the scope dorsally.
The scapholunate articulation can be seen proximally and ulnarly; it can be probed for instability or step-off. Further ulnarly, the lunotriquetral articulation is visualized.
Moving the scope superiorly yields oblique views of the proximal surface capitate and hamate as well as the capitohamate interosseous ligament.
The continuation of the radioscaphocapitate ligament, which forms the radial arm of the arcuate ligament (ie, the scaphocapitate ligament) can occasionally be seen across the midcarpal space.
MIDCARPAL ULNAR PORTAL
The midcarpal ulnar port is found 1 cm distal to the 4–5 portal and 1.5 cm ulnar and slightly proximal to the midcarpal radial portal, in line with the ring metacarpal axis.
This entry site is at the intersection of the lunate, triquetrum, hamate, and capitate with a type I lunate facet and directly over the lunotriquetral joint with a type II lunate facet.11
This portal provides preferential views of the lunotriquetral articulation.
Directly anteriorly, the ulnar limb of the arcuate ligament (ie, the triquetro-hamate-capitate ligament) can be seen as it crosses obliquely from the triquetrum, across the proximal corner of the hamate to the palmar neck of the capitate.
This is especially important in midcarpal instability.
Normally there is very little step-off between the distal articular surfaces of the scaphoid and lunate.
Direct pressure from the scope combined with traction may force the carpal joints out of alignment.
The traction should be released and the scapholunate joint should be viewed with the scope in the midcarpal ulnar portal, whereas the lunotriquetral joint should be viewed with the scope in the midcarpal radial portal.
VOLAR RADIAL PORTAL
A 2-cm transverse or longitudinal incision is made in the proximal wrist crease overlying the flexor carpi radialis tendon. The portal is established in the usual manner (TECH FIG 2).
It is not necessary to specifically identify the adjacent neurovascular structures, provided that the anatomic landmarks are adhered to.
A hook probe is inserted through the 3–4 portal and used to assess the palmar aspect of the SLIL and the DRCL.
A useful landmark when viewing from the volar radial portal is the intersulcal ridge between the scaphoid and lunate fossae.
The radial origin of the DRCL is seen immediately ulnar to this, just proximal to the lunate.
TECH FIG 2 • Technique for volar radial portal. A. Skin incision for volar radial portal. FCR, flexor carpi radialis tendon. B. Saline injection of radiocarpal joint. C. Insertion of cannula through floor of the FCR sheath. (From Slutsky DJ. Volar portals in wrist arthroscopy. J Am Soc Surg Hand 2002;2:225–232.)
VOLAR RADIAL MIDCARPAL PORTAL
The volar aspect of the midcarpal joint can be accessed through the same skin incision as the volar radial portal.
The capsular entry site through the volar radial midcarpal portal is entered by angling the trocar 1 cm distally and about 5 degrees ulnarward to the radiocarpal site.
A hook probe can be inserted dorsally in the midcarpal radial portal for palpation.
With tears of the palmar SLIL one can see the intact dorsal fibers and the volar surface of the capitate.
VOLAR ULNAR PORTAL
The volar ulnar portal is established via a 2-cm longitudinal incision centered over the proximal wrist crease along the ulnar edge of the finger flexor tendons (TECH FIG 3).
The tendons are retracted to the radial side and the radiocarpal joint space is identified with a 22-gauge needle.
Care is taken to situate the portal underneath the ulnar edge of the flexor tendons and to apply retraction in a radial direction alone to avoid injury to the ulnar nerve and artery.
The median nerve is protected by the interposed flexor tendons.
The palmar region of the LTIL can usually be seen slightly distal and radial to the portal.
A hook probe is inserted through the 6R or 6U portal.
TECH FIG 3 • Technique for volar ulnar portal. A. Skin incision for volar ulnar portal. FCR, flexor carpi radialis tendon; FDS, flexor digitorum sublimis. B. FDS retracted, saline injection of radiocarpal joint. C. Insertion of cannula through capsule deep to FDS tendons. (From Slutsky DJ. The use of a volar ulnar portal in wrist arthroscopy. Arthroscopy 2004;20:158–163.)
VOLAR DRUJ PORTAL
The volar DRUJ portal is accessed through the volar ulnar skin incision.
The joint is entered by angling the 22-gauge needle 45 degrees proximally.
It is useful to leave a needle or cannula in the ulnocarpal joint for reference.
Alternatively, a probe can be placed in the distal DRUJ portal and advanced through the palmar incision to act as a switching stick over which the cannula can be threaded.3
Initially, the space appears quite limited, but over the course of 3 to 5 minutes the fluid irrigation expands the joint space, which improves visibility.
A 3-mm hook probe is inserted through the dorsal distal DRUJ portal for palpation.
A burr or thermal probe can be substituted as necessary.
Direct visualization of the foveal attachment prevents accidental injury to this structure.
The articular disc is seen superiorly.
Proximal surface tears of the TFCC, which are usually caused by severe axial load, may be detected through this portal.
The dome of the ulnar head lies inferiorly.
The TFCC attachment to the sigmoid notch can be palpated with a hook probe in the distal dorsal DRUJ portal as it penetrates the dorsal DRUJ capsule.
The deep attachments of the dorsal radioulnar ligament can be seen as it inserts into the fovea.
In ideal cases, the conjoined tendon of the dorsal radioulnar ligament, ulnar collateral ligament, and palmar radioulnar ligament can be visualized.
DORSAL DRUJ PORTALS
The dorsal aspect of the DRUJ can be accessed through proximal and distal portals.
The proximal DRUJ portal is located in the axilla of the joint, just proximal to the sigmoid notch and the flare of the ulnar metaphysis.
This portal is easier to penetrate and should be used initially to prevent chondral injury from insertion of the trocar.
The forearm is held in supination to relax the dorsal capsule, to move the ulnar head volarly, and to lift the central disc distally from the head of the ulna.
Reducing the traction to 1 to 2 pounds permits better views between the ulna and the sigmoid notch by reducing the compressive force caused by axial traction.
The joint space is entered by inserting a 22gauge needle horizontally at the neck of the distal ulna.
Fluoroscopy facilitates needle placement.
The distal dorsal DRUJ portal is identified 6 to 8 mm distally with the 22-gauge needle, and just proximal to the 6R portal.
This portal can be used for outflow drainage or for instrumentation.
It lies on top of the ulnar head but underneath the TFCC and so is difficult to use in the presence of positive ulnar variance.
The TFCC has the least tension in neutral rotation of the forearm, which is the optimal position for visualizing the articular dome of the ulnar head, the undersurface of the TFCC, and the proximal radioulnar ligament from its attachment to the sigmoid notch to its insertion into the fovea of the ulna.
Because of the dorsal entry of the arthroscope, the course of the dorsal radioulnar ligament is not visible until its attachment into the fovea is encountered.
Entry into this portal provides views of the proximal sigmoid notch cartilage and the articular surface of the neck of the ulna.
POSTOPERATIVE CARE
The postoperative rehabilitation depends on the specific procedure that is performed.
After diagnostic arthroscopy, with or without débridement, the patient is splinted for comfort for a brief period of 4 to 7 days.
Active wrist motion is encouraged after this period and patients are allowed activities of daily living, followed by gradual strengthening.
If a ligament repair or TFCC repair has been performed or if there is interosseous pinning, the protocol is adjusted as necessary and typically involves an initial period of immobilization before instituting wrist motion.
COMPLICATIONS
Most of the complications related to use of the dorsal portals are related to injury to the sensory branches of the superficial radial nerve and the dorsal cutaneous branch of the ulnar nerve.
The palmar cutaneous branch of the ulnar nerve is at risk with the volar radial portal, although the interposed flexor carpi radialis tendon mitigates this risk.
There is no true internervous plane when using the volar ulnar portal; hence, sensory branches of the palmar cutaneous branches of the ulnar nerve or nerve of Henle are always at risk. Thus, proper wound spread technique is paramount.
The ulnar neurovascular bundle is also potentially at risk with overzealous retraction or poor portal placement.
Venous bleeding, loss of wrist motion (especially forearm supination), complications related to fluid extravasation, and infection are general risks attendant to any arthroscopic procedure.
These can be minimized by fastidious surgical technique, aggressive rehabilitation as necessary, and diligent followup in the early postoperative period.
REFERENCES
1. Berger RA. Arthroscopic anatomy of the wrist and distal radioulnar joint. Hand Clin 1999;15:393–413.
2. 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.
3. Slutsky DJ. Distal radioulnar joint arthroscopy and the volar ulnar portal. Tech Hand Up Extrem Surg 2007;11:38–44.
4. Slutsky DJ. Arthroscopy portals: volar and dorsal. In Budoff J, Slade JF, Trumble TE, eds. Master's Techniques in Wrist and Elbow Arthroscopy. Chicago: American Society for Surgery of the Hand, 2006.
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