Introduction

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. Anatomical 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 continued to push the envelope through the development of techniques for treating intracarpal pathology, which in turn culminated in a plethora of new accessory portals. This chapter explores the standard arthroscopic portals, as well as some of the more recent and special-use portals.¹

Indications

The indications for the use of the standard dorsal portals are intertwined with the indications for wrist arthroscopy and are largely dependent on the indication for surgery, in that this will vary considerably between arthroscopic fracture reduction compared to performing a diagnostic procedure for chronic wrist pain. These include variable combinations of the 3-/,4 portal, the 4-/,5 portal, and the 6 radial (6R) and 6 ulnar (6U) portals. Typically, the 3-/,4 and 4,/-5 portals are used interchangeably for visualizing the radiocarpal joint and for instrumentation. The 4-/,5 portal and the 6R portal are used to access the ulnocarpal joint. The 6U portal is typically used for outflow. However, with careful attention to surface landmarks any portal can be used for viewing or instrumentation.

Midcarpal arthroscopy is essential in making the diagnosis of scapholunate and lunotriquetral instability. The grading scale reported by Geissler et al.² provides a means of staging the degree of instability in order to provide an algorithm for treatment. Midcarpal arthroscopy is also useful for the assessment and treatment of chondral lesions of the proximal hamate.³ The triquetro-hamate joint can also be accessed through another special-use midcarpal portal.⁴

The clinical utility of volar portals has been recently elucidated.^5–7 As kinematic and biomechanical studies have shed light on the role of the dorsal capsular structures and palmar subregions of the interosseous ligaments in maintaining carpal stability, it has become prudent to view the wrist from a palmar perspective. Volar portals for wrist arthroscopy have certain advantages over the standard dorsal portals for visualizing dorsal capsular structures as well as the palmar aspects of the carpal ligaments. The volar radial (VR) portal is relatively easy to use and is an ideal portal for evaluation of the dorsal radiocarpal ligament (DRCL) and the palmar subregion of the scapholunate interosseous ligament (SLIL). It facilitates the identification of and repair of DRCL tears.^8,9 The VR portal also facilitates arthroscopic reduction of intra-articular fractures of the distal radius fractures by providing a clear view of the dorsal rim fragments.¹⁰

The volar radial midcarpal (VRM) portal may be considered an occasional accessory portal for visualizing the palmar aspects of the capitate and hamate in cases of avascular necrosis or osteochondral fractures.⁶ This portal facilitates visualization of the palmar aspect of the capitohamate interosseous ligament (CHIL), which is important in minimizing translational motion¹¹ and has an essential role in providing stability to the transverse carpal arch.¹²

The volar ulnar (VU) portal provides unparalleled views of the dorsal radioulnar ligament and the dorsal ulnar wrist capsule, which contains the extensor carpi ulnaris subsheath (ECUS). Establishing the VU portal is more technically demanding but has potential use in the arthroscopic diagnosis and treatment of patients with ulnar sided wrist pain and suspected injuries to the ulnar sling mechanism. It is especially useful for visualizing and debriding palmar tears of the lunotriquetral ligament.¹³ It also aids in the repair or debridement of dorsally located TFC tears because the proximity of the 4/-,5 and 6R portals makes triangulation of the instruments difficult. The volar aspect of the distal radioulnar joint can be visualized through the VU portal to assess the foveal attachment of the triangular fibrocartilage in cases of suspected peripheral detachment of the TFC.⁷

Two dorsal DRUJ portals have been described. The dorsal DRUJ portals may be used to assess the status of the articular cartilage of the ulnar head and sigmoid notch. This information may be useful in cases of DRUJ instability, or when there is the suspicion of early osteoarthritis (in which case arthroscopy may differentiate between the need for DRUJ stabilization or ulnar head excision and arthroplasty. With inflammatory disorders such as rheumatoid arthritis DRUJ, an arthroscopic synovectomy may obviate the need for a capsular incision. The dorsal DRUJ portals are infrequently used as an adjunct to arthroscopic wafer resections of the ulnar head.

Contraindications

Contraindications to the use of dorsal or volar portals include any cause of marked swelling that distorts the topographic anatomy, large capsular tears that might lead to extravasation of irrigation fluid, neurovascular compromise, bleeding disorders, and infection. Unfamiliarity with the regional anatomy is a relative contraindication.

Relevant Anatomy

The standard portals for wrist arthroscopy are mostly dorsal (Figure 1.1a through 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, which allow access to the radiocarpal joint, are so named in relation to the tendons of the dorsal extensor compartments. For example, the 1-/,2 portal lies between the first extensor compartment tendons—which include the extensor pollicus brevis (EPB) and the abductor pollicus longus (APL)—and the second extensor compartment, which contains the extensor carpi radialis brevis and longus (ECRB/L).

FIGURE 1.1 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 pollicus longus, SRN = superficial radial nerve, Lister’s tubercle = *). (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.

The 3-/,4 portal is named for the interval between the third dorsal extensor compartment—which contains the extensor pollicus longus tendon (EPL)—and the fourth extensor compartment, which contains the extensor digitorum communis (EDC) tendons. In a similar vein, 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, compared to the 6U portal (which 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 (MCR) is located 1 cm distal to the 3-/,4 portal and is bounded radially by the ECRB and ulnarly by the EDC. The ulnar midcarpal portal (MCU) is similarly located 1 to 1.5 cm distal to the 4-/,5 portal and is bounded by the EDC and the EDM.

The relative safety of the portals has been studied by way of cadaver dissection. Although some artifact is inescapable due to the displacement of neurovascular structures postmortem, this research provides useful guidelines. In the clinical situation, distortion of the topographical anatomy due to fracture/dislocation or swelling as well as the use of intraoperative traction may increase the potential for harm. Hence, a standardized method for establishing each portal is useful.

Dorsal Cortals

Dorsal Radiocarpal Portals

Abrams and co-workers performed anatomical dissections on 23 unembalmed fresh cadaver extremities and measured the distances between the standard dorsal portals and the contiguous neurovascular structures.¹⁴ The 1-/,2 portal was found to be the most perilous. The radial sensory nerve exits from under the brachioradialis approximately 5 cm proximal to the radial styloid and bifurcates into a major volar and a major dorsal branch at a mean distance of 4.2 cm proximal to the radial styloid¹⁵ (Figure 1.2). Branches of the superficial radial nerve (SRN) that were radial to the portal were within a mean of 3 mm (range 1 to 6 mm), whereas branches that were ulnar to the portal were at a mean of 5 mm (range 2 to 12 mm).

FIGURE 1.2 Branches of the superficial radial nerve (SRN; SR1 = minor dorsal branch, SR2 = major dorsal branch, SR3 = major palmar branch).

The radial artery was found at an average of 3 mm radial to the portal (range 1 to 5 mm). Either partial or complete overlap of the lateral antebrachial cutaneous nerve (LABCN) with the SRN occurs up to 75% of the time.¹⁶ In an anatomical study by Steinberg et al., the LACBN was present within the anatomical snuffbox in 9 of 20 (45%) specimens. Based on these findings, they recommended a more palmar, proximal portal in the snuffbox that was no more than 4.5 mm dorsal to the first extensor compartment and within 4.5 mm of the radial styloid.¹⁵

Branches of the SRN that were radial to the 3-/,4 portal were located at a mean distance of 16 mm (range 5 to 22 mm). In one specimen, an ulnar branch of the SRN was found 6 mm ulnar to the portal. The distance to the radial artery was a mean of 26.3 mm (range 20 to 30 mm). Sensory nerves were remote to the 4-/,5 portal, except in one case (where an aberrant SRN branch was found 4 mm radial to the portal).

The dorsal cutaneous branch of the ulnar nerve (DCBUN) arises from the ulnar nerve an average of 6.4 cm (SD = 2.3 cm) proximal to the ulnar head and becomes subcutaneous 5 cm proximal to the pisiform. It crosses the ulnar snuffbox and gives off three to nine branches that supply the dorsoulnar aspect of the carpus, small finger, and ulnar ring finger.¹⁷ The mean distance of the dorsal cutaneous branch of the ulnar nerve (DCBUN) to the 6R portal was 8.2 mm (range 0 to 14 mm). Transverse branches of the DCBUN were found in 12 of 19 specimens and were noted to be within 2 mm of the portal (range 0 to 6 mm). The mean distance of branches of the dorsal cutaneous branch of the ulnar nerve (DCBUN) that were radial to the 6U portal was 4.5 mm (range 2 to 10 mm), whereas branches that were ulnar to the portal ranged from 1.9 to 4.8 mm on average. Any transverse branches of the DCBUN were generally proximal to the portal, at an average of 2.5 mm.

Dorsal Midcarpal Portals

Branches of the SRN were found radial to the MCR portal at a mean of 7.2 mm (range 2 to 12 mm; SD = 2.7) Two specimens contained SRN branches ulnar to the portal at 2 and 4 mm. Branches of the SRN were generally remote from the MCU portal except in one specimen (1 mm). Branches of the DCBUN were found at a mean distance of 15.1 mm (range 0 to 25 mm; SD = 4.6).

Triquetro-Hamate (TH) Portal

This portal enters the midcarpal joint at the level of the triquetro-hamate joint ulnar to the ECU tendon. The entry site is both ulnar and distal to the MCU. Branches of the DCBUN are most at risk (Figure 1.3).

FIGURE 1.3 View of the ulnar aspect of a left wrist demonstrating the relative positions of the triquetro-hamate (T-H) portal and the 6U portal (DCBUN = dorsal cutaneous branch of the ulnar nerve, UN = ulnar nerve).

Dorsal Radioulnar Portals

These portals lie between the ECU and the EDM tendons. Transverse branches of the DCBUN were the only sensory nerves in proximity to the dorsal radioulnar portal at a mean of 17.5 mm distally (range 10 to 20 mm) (Figure 1.4a and b).

FIGURE 1.4 Dorsal DRUJ portal anatomy. (A) Relative position of the proximal (PDRUJ) and distal (DRUJ) portals. (B) Close-up with the dorsal capsule removed, demonstrating the position of the needles in relation to the dorsal radioulnar ligament [(*); AD = articular disk, UC = ulnocarpal joint, UH = ulnar head].

Volar Portals

Volar Radial (VR) Portal

An anatomical study was performed on the arms of five fresh frozen cadavers to determine the safe landmarks for a volar radial (VR) portal after arterial injection studies to highlight the vascular anatomy.⁶ The proximal and distal wrist creases were marked. The volar skin was then removed and the flexor carpi radialis tendon (FCR) sheath was divided. The tendon was retracted ulnarly and a trochar was inserted into the radiocarpal joint at the level of the proximal wrist crease. The trochar was noted to enter the radiocarpal joint between the radioscaphocapitate ligament (RSC) and the long radiolunate ligament (LRL) in four specimens and through the LRL ligament in one specimen (Figure 1.5). The median nerve was 8 mm (range 6 to 10 mm) ulnar to the VR portal, whereas the palmar cutaneous branch passed 4 mm (range 3 to 5 mm) ulnar to the portal.

FIGURE 1.5 Ligamentous interval of VR and VU portals. Radiocarpal joint viewed from the dorsal aspect of a hyperflexed wrist. A needle in the VR portal (*) enters between the radioscaphocapitate (RSC) and long radiolunate (LRL) ligaments. A needle in the VU portal enters between the ulnolunate and ulnotriquetral ligaments (UL/UT). Abbreviations: S = scaphoid, L = lunate, R = radius, RSL = radioscapholunate ligament, SLIL = scapholunate interosseous ligament.

The radial artery was 5.8 mm (range 4 to 6 mm) radial to the portal and its superficial palmar branch was located 10.6 mm (range 6 to 16 mm) distal to the portal. The superficial radial nerve lay 15.6 mm (range 12 to 19 mm) radial to the portal. The portal was 12.8 mm (range 12 to 14 mm) distal to the border of the pronator quadratus, which roughly corresponds to the palmar radiocarpal arch.¹⁸ The palmar cutaneous branch was closest in proximity but always lies to the ulnar side of the FCR.^19,20 The superficial palmar branch of the radial artery passed through the subcutaneous tissue over the tuberosity of the scaphoid and was out of harms way with an incision at the proximal wrist crease.^21,22 When the trochar was placed through the floor of the FCR tendon sheath at the proximal palmar crease, the carpal canal was not violated. It was thus apparent that there was a safe zone comprising the width of the FCR tendon and at least 3 mm or more in all directions. This zone was free of any neurovascular structures.

Volar Radial Midcarpal (VRM) Portal

The volar aspect of the midcarpal joint was identified with a 22-gauge needle through the same skin incision and a blunt trochar was inserted. It was necessary to angle the trochar in a distal and ulnar direction (approximately 5 degrees) in order to access the midcarpal joint through the same skin incision. The trochar passed closer to (but still deep to) the superficial palmar branch of the radial artery, which coursed more superficially over the scaphoid tuberosity at that level. The distance between the volar radiocarpal and volar midcarpal entry sites averaged 11 mm (range 7 to 12 mm).

Volar Ulnar (VU) Portal

In a companion study, a volar ulnar (VU) portal was established via a 2-cm longitudinal incision made along the ulnar edge of the finger flexor tendons at the proximal wrist crease.¹³ The flexor tendons were retracted radially and a trochar was introduced into the radiocarpal joint. The ulnar styloid marked the proximal point of the VU portal, approximately 2 cm distal to the pronator quadratus. The portal was in the same sagittal plane as the ECU subsheath and penetrated the ulnolunate ligament (ULL) adjacent to the radial insertion of the triangular fibrocartilage. The ulnar nerve and artery were generally more than 5 mm from the trochar, provided the capsular entry point was deep to the ulnar edge of the profundus tendons.

The palmar cutaneous branch of the ulnar nerve (nerve of Henlé) was highly variable and not present in every specimen. This inconstant branch provides sensory fibers to the skin in the distal ulnar and volar part of the forearm to a level 3 cm distal to the wrist crease. Its territory may extend radially beyond the palmaris longus tendon.²³ This branch tends to lie just to the ulnar side of the axis of the fourth ray, but it was absent in 43% of specimens in one study.²⁴ Martin et al. demonstrated that there was no true internervous plane due to the presence of multiple ulnar-based cutaneous nerves to the palm, which puts them at risk with any ulnar incision.¹⁹ Because there is no true safe zone, careful dissection and wound spread technique should be observed.

Volar Distal Radioulnar (VDR) Portal

The topographical landmarks and establishment of the portal are identical to those of the VU portal. The same risks also apply. The capsular entry point for the VDR lies 5 mm to 1 cm proximal to the ulnocarpal entry point (Figure 1.6a and b).

FIGURE 1.6 Volar DRUJ portals. (A) Volar aspect of a left wrist demonstrating the relative positions of the VU and volar DRUJ (VDR) portals in relation to the ulnar nerve (*) and ulnar artery (UA). Abbreviations: FDS = flexor digitorum sublimus, FCU = flexor carpi ulnaris. (B) Close-up view after the volar capsule is removed, showing position of needles in relation to the volar radioulnar ligament (*). Abbreviations: Tr = triquetrum, UH = ulnar head.

Field of View

The following sections describe the typical field of view as seen through a 2.7-mm arthroscope under ideal conditions.^25,26 Synovitis, fractures, ligament tears, and a tight wrist joint may limit the field of view (which necessitates the use of more portals to adequately assess the entire wrist).

Relevant Clinical and Biomechanical Studies

The publications on the use of wrist arthroscopy through the standard dorsal portals are too numerous to list here. There are, however, a number of excellent reviews the reader is directed to.^* A number of reports highlight the safety and clinical application of volar arthroscopy portals on the radial side of the wrist. Levy and Glickel²⁷ described the use of an accessory volar portal after volar plating of a Barton’s fracture that was accessed through a standard carpal tunnel incision. Tham et al.²⁸ used a volar radial portal in 14 cases (for synovectomy, radial styloidectomy, and fracture reduction). Bain and co-workers published their early experience with a volar portal in the European literature.²⁹ They subsequently reported on the use of a volar portal for arthroscopic release of wrist contracture,³⁰ as an adjunct for arthroscopic-assisted fixation of distal radius fractures,³¹ and for decompression of intraosseous ganglia of the lunate.³²

Osterman described the use of a volar radial portal for arthroscopic release of dorsal wrist contractures.³³ Doi et al. used a volar radial portal in 34 cases of arthroscopically assisted reduction of distal radius fractures.¹⁰ Abe et al. reported on the use of this portal for viewing the palmar aspects of the SLIL and LTIL ligaments in 230 cases.^34,35 Del Piñal and co-workers recently reported on the use of a volar radial portal for an inside-out osteotomy technique for correction of malunited intra-articular distal radius fractures.³⁶ Dr. Andrea Atzei and Riccardo Luchetti of Italy have used a palmar distal radioulnar joint portal that is ulnar to the TFCC. They presented their three year results at the FESSH meeting in 2005.³⁷

Author’s Experience

The volar radial portal has been used in 77 patients since 1998. Additional pathology was evident in 37 of the patients that was not visible from any standard dorsal portal. This included one case of hypertrophic synovitis of the dorsal capsule (Figure 1.7); one patient with an avulsion of the radioscapholunate ligament, which exposed the volar scapholunate cleft (Figure 1.8); two patients with tears restricted to the palmar region of the SLIL; and 35 patients with tears of the dorsal radiocarpal ligament. In five patients an isolated DRCL tear alone was responsible for chronic dorsal wrist pain (Figure 1.9a and b).

FIGURE 1.7 Hypertrophic synovitis (*) of the dorsal capsule in a case of Preiser’s disease as seen through the VR portal.

(From Slutsky DJ. Wrist arthroscopy through a volar radial portal. Arthroscopy: The Journal of Arthroscopic and Related Surgery 2002;18(6):624–30. Used with permission.)

FIGURE 1.8 Radioscapholunate ligament avulsion. Note unmasking of the palmar cleft (*) between the scaphoid and lunate (SLIL= scapholunate interosseous ligament, RSL = radioscapholunate ligament).

(From Slutsky DJ. Wrist arthroscopy through a volar radial portal. Arthroscopy: The Journal of Arthroscopic and Related Surgery 2002;18(6):624–30. Used with permission.)

FIGURE 1.9 VR portal view. (A) Normal dorsal radiocarpal ligament. Hook probe is inserted through the 3/-,4 portal (SLIL = scapholunate interosseous ligament, DRCL = dorsal radiocarpal ligament). (B) DRCL tear (*). Hook probe inserted through the 3/-,4 portal.

(From Slutsky DJ. Wrist arthroscopy through a volar radial portal. Arthroscopy: The Journal of Arthroscopic and Related Surgery 2002;18(6):624–30. Used with permission.)

The midcarpal joint was accessed from the volar radial portal in three cases. In one patient with Preiser’s disease the use of the volar radial midcarpal portal (VRM) allowed a more complete assessment of the distal articular surface of the scaphoid. Another patient had an unrecognized osteochondral fracture of the capitate head following a perilunate dislocation. The VRM portal admirably demonstrated the intact dorsal portion of the SLIL in the patient with the palmar tear (Figure 1.10). Using the dorsal midcarpal portals, one patient was found to have a chondral defect on the proximal hamate, along with a midcarpal loose body (Figure 1.11a and b).

FIGURE 1.10 Volar midcarpal portal. Tear of the palmar region of the SLIL (scapholunate interosseous ligament) as viewed from the volar radial midcarpal portal. Note the intact dorsal fibers of the SLIL.

FIGURE 1.11 Dorsal midcarpal portal. (A) Chondral defect on proximal hamate. (B) Loose body in midcarpal joint.

The VU portal was used in 49 of these patients. The ulnar sided pathology included 13 tears of the LTIL ligament, 11 TFC tears, and 2 ulnolunate ligament tears. In one patient a TFC tear was found to extend into the dorsoulnar ligament (see Figure 1.12a and b). The VU portal facilitated debridement of the palmar region of the LTIL ligament through the 6R or 6U portals (Figure 1.13). In 2 of these patients unrecognized chondromalacia of the palmar aspect of the lunate was identified (see Figure 1.14). In 1 patient, the palmar aspect of the LTIL was found to be intact despite a large dorsal tear.

FIGURE 1.12 VU portal view. (A) Triangular fibrocartilage (TFC) tear extending into the dorsal radioulnar ligament. Probe inserted through the dorsal 4/-,5 portal. (B) Palpation of the dorsal radioulnar ligament tear with the hook probe.

(From Slutsky DJ. The use of a volar ulnar portal in wrist arthroscopy. The Journal of Arthroscopic and Related Surgery 2004;20(2):158–63. Used with permission.)

FIGURE 1.13 Palmar lunotriquetral ligament tear as viewed from the volar ulnar (VU) portal. Note the avulsed ligament (*) still attached to the triquetrum, with the exposed cleft between the lunate and triquetrum.

(From Slutsky DJ. Wrist arthroscopy through a volar radial portal. Arthroscopy: The Journal of Arthorscopic and Related Surgery 2002;18(6):624–30. Used with permission.)

FIGURE 1.14 Unsuspected region of chondromalacia on the palmar surface of the lunate (LT = lunotriquetral).

(From Slutsky DJ. The use of a volar ulnar portal in wrist arthroscopy. The Journal of Arthroscopic and Related Surgery 2004;20(2): 158–63. Used with permission.)

The volar aspect of the DRUJ portal was used in six of these patients to rule out a peripheral detachment of the TFC (2 with ulnar styloid fracture/nonunion). This would normally require a formal open arthrotomy and a high index of clinical suspicion.⁴¹ The DRUJ was well visualized and the foveal attachment of the TFC was clearly identified (see Figure 1.15). In one patient with a TFC and LTIL tear, a wafer resection was performed by inserting the bur through the dorsal DRUJ portal while viewing through the VDRU. This allows for a more conservative TFC debridement since the ulnar head resection if performed underneath the TFC tear and not through it. The DRUJ wafer also facilitates preservation of the volar and dorsal radioulnar ligaments as well as the deep foveal attachment.

FIGURE 1.15 View from the palmar DRUJ portal. The undersurface of the TFC (triangular fibrocartilage) demonstrates no tears, with a solid attachment to the fovea of the ulnar styloid.

Equipment and Implants

Methodology

It is useful to have a systematic approach to viewing the wrist. The structures that should be visualized as part of a standard exam include the radius articular surface, the proximal scaphoid and lunate, the SLIL and LTIL (palmar and dorsal for each), RSC, LRL, RSL, ULL, ULT, 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 VR portal in order to visualize the palmar SLIL and the DRCL ligament to minimize any error from iatrogenic trauma to the dorsal capsular structures. This is followed by the VU portal to assess the palmar LTIL and dorsal radioulnar ligament, ECU subsheath, and radial TFC 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 may be used for instrumentation when debriding palmar LTIL tears. Midcarpal arthroscopy is then performed to probe the SLIL and LTIL joint spaces for instability, to examine the capitohamate interosseous ligament (CHIL), and to look for chondral lesions on the proximal capitate and hamate and loose bodies. The special use portals such as the dorsal and volar DRUJ portals and the 1-/,2 portal are used as needed. The accompanying video illustrates the portal placement and technique.

Volar Portals

To establish the volar radial portal the surgeon is now seated, facing the volar aspect of the wrist. A 2-cm transverse or longitudinal incision is made in the proximal wrist crease overlying the flexor carpi radialis (FCR) tendon. It is not necessary to specifically identify the adjacent neurovascular structures, provided the anatomical landmarks are adhered to. The tendon sheath is divided and the FCR tendon is retracted ulnarly. The radiocarpal joint space is identified with a 22-gauge needle and distended with 5 cc of saline. Blunt tenotomy scissors or forceps are used to pierce the volar capsule. A blunt trochar is then introduced, followed by a 2.7-mm 30-degree angled arthroscope (Figure 1.16a through c). The midcarpal joint can be accessed through the same skin incision by angling the trochar 1 cm distally and approximately 5 degrees ulnarward. Outflow is established via an 18-gauge needle in the 6U portal or a cannula.

FIGURE 1.16 Technique for VR portal. (A) Skin incision for VR 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. JASSH 2002;2(4):225–32. Used with permission.)

The standard dorsal portals (including the 3/-,4 and 4/-,5 portals as well as the radial and ulnar midcarpal portals) are established in a similar fashion. 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 VR 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.

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 (Figure 1.17a through c). The tendons are retracted to the radial side and the radiocarpal joint space is identified with a 22-gauge needle. Blunt tenotomy scissors or forceps are used to pierce the volar capsule, followed by insertion of a cannula and blunt trochar, followed by the arthroscope. The ulnar nerve is protected by use of the cannula and a more radial entry site. The median nerve is protected by the adjacent 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.

FIGURE 1.17 Technique for VU portal. (A) Skin incision for VU portal (FCR = flexor carpi radialis tendon, FDS = flexor digitorum sublimes). (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. The Journal of Arthroscopic and Related Surgery 2004;20(2):158–63. Used with permission.)

The dorsal radioulnar joint can be accessed through a proximal and distal portal.⁴⁰ The proximal portal (PDRUJ) 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 trochar. 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 identified by first inserting a 22-gauge needle horizontally at the neck of the distal ulna. Fluoroscopy facilitates the needle placement. The joint is infiltrated with saline and the capsule is spread with tenotomy scissors through a small incision. A small cannula and trochar for the 1.9-mm scope are introduced, followed by insertion of a 1.9-mm 30-degree angle scope. Entry into this portal provides views of the proximal sigmoid notch cartilage and the articular surface of the neck of the ulna. One should systematically look for loose bodies or synovial hypertrophy.

The distal portal (DDRUJ) 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 TFC. Hence, it cannot be used in the presence of a positive ulnar variance. The TFC 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 TFC, 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.²⁵ Proximal surface tears of the TFC (which are usually caused by severe axial load) may be detected through this portal.

The volar DRUJ portal is accessed through the VU skin incision. A 1.9-mm small joint arthroscope is used since gaining access to the DRUJ can be difficult, especially in a small wrist. The joint is first identified by angling a 22-gauge needle 45° proximally, and then injecting the DRUJ with saline. It is useful to leave a needle or cannula in the ulnocarpal joint for reference during this step. Alternatively, a probe can be placed in the distal dorsal radioulnar joint portal and advanced through the palmar incision to help locate the joint space. Care is taken to situate the portal underneath the ulnar edge of the flexor tendons and to apply retraction in a radial direction alone, in order to avoid injury to the ulnar nerve and artery. Once the correct plane is identified, the volar DRUJ capsule is pierced with tenotomy scissors followed by a cannula with a blunt trochar and then the arthroscope. The dorsal distal DRUJ portal can be used for instrumentation such as a thermal probe or bur while viewing through the VDRU portal (Figure 1.18a and b).⁴⁰

FIGURE 1.18 View from the volar DRUJ portal. (A) Thermal probe is in the dorsal DRUJ portal. (B) Tear of the TFC as seen from the VDRU portal.

The Dry Technique of Wrist Arthroscopy

Dr. Francisco del Piñal of Santander, Spain, has pioneered a dry technique for diagnostic wrist arthroscopy.⁴¹ In his experience, this technique is as effective as the standard procedure but without the disadvantages of fluid extravasation, which minimizes the risk of compartment syndrome during the arthroscopic treatment of distal radius fractures. The hand is suspended from a custom-made traction bow that allows one to easily change the hand from a horizontal to a vertical position while maintaining a sterile field. The arthroscopy portals are made and instruments inserted as in the usual fashion, except for the fact that no irrigation fluid is used to distend the joint. To periodically dry the joint out, he uses neurosurgical patties cut into small triangles.

One must avoid getting too close with the tip of the scope when working with burs or osteotomes, in order to avoid splashes that might impede vision. Blood clots or debris are first wetted with 10 or 20 cc of saline through the side valve of the scope and then aspirated with a synoviotome. He has thus far carried out the dry technique in more than 100 wrist arthroscopies without any complications (personal communication, del Piñal June 2006). In my experience, it is still necessary to use fluid to make the diagnosis of a DRC ligament tear. Copious joint irrigation is also necessary whenever a thermal probe is used, to minimize the risk of heat necrosis of the articular cartilage.

Rehabilitation

The postoperative rehabilitation is dictated by the treatment of the specific pathology. Finger motion and edema control are instituted immediately. TFC repairs and interosseous pinning may require up to six to eight weeks of immobilization. If an arthroscopic DRCL is repaired the patient is placed in a below-elbow cast or splint for six weeks, with the restriction of all wrist motion. Forearm pronation and supination is permitted. This is followed by wrist motion exercises and gradual strengthening. Following arthroscopic debridement alone, wrist range of motion exercises are instituted within three to five days postoperatively.

Summary

Advances in wrist arthroscopy continue to expand the indications and treatment options for myriad wrist disorders. A systematic approach and a thorough understanding of the topographical and internal anatomy of the wrist are integral to minimizing complications while maximizing the chances of a successful outcome.