Arthroscopic Proximal Row Carpectomy Using the Volar Central Portal.

Proximal row carpectomy (PRC) is a well-accepted procedure for the treatment of degenerative lesions of the wrist and advance Kienböck disease. This procedure has been classically described as an open procedure but recently has been reported as an arthroscopic one. Arthroscopic PRC has several advantages such as minimal damage to the dorsal and volar ligaments as well as there being no need to detach the capsule, which can facilitate earlier mobilization and can decrease postoperative stiffness. In addition, there is a reduced risk of the interosseous posterior nerve being injured, and the proprioception system continues to function. This arthroscopically assisted technique uses the volar central portal as a third portal, which can be useful to remove the volar portions of the bones to view the dorsal areas of the bones and to allow the surgeon to work with 2 instruments at the same time. As a result, the time spent on the procedure can be reduced.

Proximal row carpectomy (PRC) is a well-accepted procedure for the treatment of degenerative lesions of the wrist and advance Kienböck disease. Favorable results have been reported, even after a follow-up period of 10 years, including an average satisfaction rate of 90%, an average failure rate of 12%, and a range of motion and grip strength of 68° and 80%, respectively, for the contralateral extremity.

This procedure has been classically described as an open procedure but recently has been reported as an arthroscopic procedure. The advantages of arthroscopic PRC (APRC) include minimal damage to the dorsal and volar ligaments as well as there being no need to detach the capsule. These advantages facilitate earlier mobilization and can decrease postoperative stiffness. In addition, there is a reduced risk of injury to interosseous posterior nerve, and the proprioception system continues to function. By performing arthroscopy beforehand, the suitability of the technique can be assessed by directly observing the cartilaginous surface of the capitate and distal radius.

Arthroscopic PRC is not a widely implemented procedure because of its technical difficulty and because it is more time consuming than an open procedure. To date, there are only 2 reports that have described arthroscopic PRC. The dorsal portals were used in both of them as viewing and working portals.2, 3

The volar central portal is a portal that allows safe access to the midcarpal joint centered on the lunate and without damaging the volar ligaments. In PRC, a volar “third portal” in the midcarpal joint can be very useful because it can be used to remove the volar portions of the bones to view the dorsal areas of the bones and to allow the surgeon to work with 2 instruments at the same time. As a result, the time spent on the procedure can be reduced.

The purpose of this article is to describe PRC with the use of dorsal midcarpal portals and the volar central portal for the midcarpal joint and several other technical details that can shorten the surgical time.

Surgical Technique

The patient is placed supine on the operating table. The wrist is suspended in a traction tower (Acumed, Hillsboro, OR) that applies 10 pounds of traction. The inflow (lactated Ringer solution) is gravity-fed. Routine dorsal radiocarpal and midcarpal portals are established, including 3-4, 6R (radial), midcarpal radial (MCR), and midcarpal ulnar (MCU). The fluoroscopy arm is positioned in a horizontal plane, and it is covered by a sterile drape so a fluoroscopic view can be obtained without releasing the traction and without losing sterility.

The instruments used for the APRC included a 3-mm shaver, 3-mm and 4-mm × 7-mm round burr (Arthrex, Naples, FL), a radiofrequency thermal probe (Arthocare; Smith & Nephew, London, UK), a pituitary rongeur, and a free periosteal elevator.

Diagnostic Arthroscopy and Forming the Volar Central Portal

First, we assess the integrity of the cartilage on the lunate fossae of the radius and the proximal pole of the capitate through the standard dorsal portals to confirm whether the technique will be suitable. If the cartilage has good quality, we form a midcarpal volar central portal (MVCP). The procedure for this portal has been explained in detail before. The volar central portal is formed via a 1.5-cm longitudinal incision following the longitudinal axis of the third intermetacarpal space beginning in the distal wrist crease. Through blunt dissection, all the flexor superficialis tendons and the second and third flexor profundus tendons are retracted toward the radial side, while the fourth and fifth flexor profundus tendons are retracted toward the ulnar side. The volar capsule is incised from outside to inside through the Poirier space.

The setup of the dorsal and MVCP as well as the joint exploration is performed without an infused saline, dry technique. During the rest of the procedure, we switch from the dry to the wet technique as needed. Carpal bones of the proximal row are usually removed with burrs and the pituitary rongeur in the dry technique, whereas infused saline is used to aspirate all the bone debris, and the radiofrequency thermal probe is used to coagulate any bleeding.

Excision of the Volar Portion of the Lunate Scaphoid and Triquetrum Through the Volar Central Portal for the Midcarpal Joint

The dorsal MCU and MCR portals are used as a viewing portal and the MVCP for instrumentation, respectively. A 3-mm round burr is used to decorticate the volar portion of the lunate, and the surgeon takes care not to injure the cartilaginous surface of the proximal pole of the capitate. Once an adequate portion is removed, a 4-mm burr is introduced to remove the volar portion of the lunate, triquetrum, and the scaphoid faster. The burr is used to remove the inner portion of the bone, which left a cartilaginous surface resembling an eggshell behind. Next, the shell of the bones is removed using the pituitary rongeur. During this step, a free periosteal elevator is introduced from the MCR or the MCU, and through this approach, the cartilage of the capitate is protected while the burr is used to excise the volar portion (Fig 1).

Fig 1

Excision of the volar portion of lunate, scaphoid, and triquetrum through the volar central portal for the midcarpal joint in the left wrist of a patient on a traction tower. (A) Burr on the lunate viewed through the dorsal ulnar midcarpal joint. (B) Burr in the scaphoid viewed through the dorsal ulnar midcarpal portal. A periosteal elevator is applied to the distal surface of the scaphoid through the dorsal radial midcarpal portal. (C) Burr on the triquetrum viewed through the dorsal radial midcarpal portal. A periosteal elevator was applied to the distal surface of the triquetrum through the dorsal ulnar midcarpal portal.

Excision of the Remaining Scaphoid, Lunate, and Triquetrum Through the Dorsal Midcarpal Portals

The MVCP is used as a viewing portal, and the MCR and MCU portals are used for instrumentation. Again, the inner portions of the bones are removed with the burr, and the shell of the bones is removed with the pituitary rongeur in a piecemeal fashion (Fig 2). The bone fragments attached to the joint capsule can be detached with the aid of the free periosteal elevator. Once the proximal row is removed, the hypertrophic synovium is resected with a 3-mm shaver and coagulated with an electrothermal probe (Table 1, Fig 3, Video 1).

Fig 2

Excision of the dorsal portion of the lunate, scaphoid and triquetrum through the dorsal midcarpal portals in a patient's left wrist on a traction tower. The view is through the volar central portal for the midcarpal joint. (A) Excision of the scaphoid with a pituitary rongeur through the dorsal midcarpal radial portal. (B) Excision of the lunate with a pituitary rongeur through the dorsal midcarpal radial portal. (C) Excision of the triquetrum with a pituitary rongeur through the dorsal midcarpal ulnar portal.

Table 1

Pearls and Pitfalls

Pearls

Pitfalls

1. The volar central portal should be performed at the beginning of the surgical procedure because the wrist is not swollen at that point.2. We usually use dry arthroscopy, but in some instances, we substitute dry arthroscopy with wet arthroscopy to remove bone debris and to coagulate blood with a thermal probe.3. A periosteal elevator placed on the distal surface of the triquetrum and scaphoid while the burr is being used can protect the distal pole of the capitate and hamate.4. We usually remove the bone with the pituitary rongeur through the dorsal portals when the volar portion has been removed through the volar central portal because we do not need to separate the soft tissues to access the joint each time we introduced the instrument.

1. Great care should be taken to avoid damaging the distal pole of the capitate when the 4-mm round burr is used.2. It is necessary to separate the soft tissues each time we access the midcarpal joint through the volar central portal.3. The bone rest attached to the joint capsule should be carefully removed to avoid injuring the extrinsic volar and dorsal ligaments.

Fig 3

Final result after proximal row carpectomy in a patient's left wrist on a traction tower. The view is through the dorsal midcarpal radial portal from the radial side (A, B) to the ulnar side (C, D).

Complications

There are potential complications, such as injury to the cartilaginous surface of the capitate and/or the distal radius, injury of the dorsal branches of the ulnar nerve when the 6R or MCU are performed, and injury to the ulnar neurovascular bundle when the volar central midcarpal portal is performed.

Discussion

The VCMP can facilitate performance of an APRC because it facilitates the resection of the volar portions of the bones and viewing of the dorsal portions. Furthermore, 2 instruments such as a free periosteal elevator and a pituitary rongeur can be used at the same time; this way, the removal of the bone fragments is easily and faster.

APRC may offer several advantages over open PRC, such as a better assessment of cartilage damage in the distal radius and capitate, minimal soft tissue damage, which preserves wrist proprioception and can decrease postoperative stiffness. Previously, the technique has been reported using dorsal portals.2, 3 The volar central portal can offer several advantages (Table 2). As it is centered on the lunate, the access to both the radial and ulnar midcarpal joints can be made through 1 incision. The resection of the volar portion of the scaphoid, lunate, and triquetrum is easier from the volar end while viewing the surgical area from the dorsal end and vice versa, and this approach leaves more space between the arthroscope and the instruments. Therefore, it is possible for the surgeon to work more comfortably, and there is a lower risk of injury from the arthroscope. Additionally, a view of the dorsal and volar midcarpal ligaments is possible during the whole procedure, which helps to preserve the ligaments. The “third” portal in the midcarpal joint allows the surgeon to work with 2 instruments at the same time (such as the periosteal elevator and the burr or the rongeur), which facilitates certain surgical steps and shortens the time required to perform them.

Table 2

Advantages and Disadvantages

Advantages

Disadvantages

1. The volar central portal allows to remove to both radial and ulnar midcarpal joint through one incision.2. The resection of the volar side of the midcarpal joint is easier from the volar end while viewing the surgical area from the dorsal and vice versa.3. The third portal leaves more space between the arthroscope and the instruments, which reduce the risk of injury to the arthroscope.4. It is possible to work with 2 instruments at the same time, which facilitates certain surgical steps.

1. It is necessary to separate the soft tissues each time we access the volar capsule, which sometimes limits the use of the pituitary rongeur through the volar central portal.

The main disadvantage of this approach is that it is necessary to separate the soft tissues each time we access the volar capsule, so we usually use the pituitary rongeur through the dorsal portal.