Rationale and Basic Science Pertinent to the Procedure

The benefits of early correction of mal–united extra–articular distal radius fractures are well known.¹ Obviously, when the mal–union affects also the joint surface the altered mechanics² will lead to rapid radiocarpal osteoarthritis in young active individuals.^3–5 Although this articular disruption calls for immediate correction, there are just a few papers that deal with the problem.^4,6–8 Recently, Ring et al.⁸ reported good results by using a direct open approach. The technique is difficult, however, and there is a risk of causing additional damage due to the limited access to the joint space through a capsulotomy incision. Furthermore, devascularization of the fracture fragments due to detachment from their soft–tissue attachments is possible.

We have performed an open osteototomy for correction of mal–united intra–articular distal radius fractures several times. We have been limited to performing relatively simple osteotomies (i.e., single longitudinal or coronal osteotomy, or simple transverse) due to the previously described difficulties. Our main concern, however, was the difficulty in visualizing the articular reduction. In effect, once the mal–united fragment was reduced (elevated) the narrow radiocarpal space prevented an adequate assessment of the joint congruity without extreme manipulation of the wrist. The surgeon must solely rely on fluoroscopy to assess the reduction, even though fluoroscopy has been shown to be unreliable with regard to evaluating any articular gap or step–off under the best of circumstances.⁹

Bearing in mind these limitations, we sought a method of assessing the status of the articular cartilage in the area of mal–union that would at the same time allow us to accurately identify fracture lines. This would allow us to carry out the osteotomy under direct visual control, which would provide an unimpeded and magnified view of the quality of the reduction. Our initial attempts with the classic (wet) arthroscopic techniques were frustrating due to fluid extravasation through the portals and air bubble formation that continually impaired the view.

Inspired by the experience with laparoscopy, in which carbon dioxide is used in place of fluid—and by the invaluable informal comments by other colleagues who were performing parts of arthroscopic ganglion resection without fluid irrigation (personal communication, doctors Atzei and Luchetti of Italy and doctors Zaidemberg and Perotto of Argentina)—we were inspired to perform wrist arthroscopy without infusing fluid (i.e., the dry technique).¹⁰ This proved to be crucial to the execution of the technique described in this chapter. An intra–articular inside–out osteotomy¹¹ of distal radius mal–unions hinges on use of the “dry” arthroscopic technique, which is therefore also presented in detail (along with some technical tips).

Indications

The procedure is indicated for nascent mal–unions (i.e., less than three months) of intra–articular fractures of the distal radius. It allows one to define each cartilage containing fragment and to recreate the original articular fracture line without fear of creating new fracture lines. The technique can be used in cases with irregularly defined fracture fragments that are not amenable to conventional osteotomy techniques. With this technique, there is minimal interference with the ligament attachments and hence with the blood supply of the osteotomized fragment.

Contraindications

There are no absolute contraindications to this technique, provided the cartilage is not worn out.¹¹ We have no experience with osteotomies older than three months. It is possible that the presence of cartilage degeneration or arthrofibrosis might impede the arthroscopic procedure, but we have no data to support or refute this. A loss of articular cartilage would preclude this operation, in which case we would then opt for an osteochondral graft¹² or a partial wrist arthrodesis.^13,14 We would therefore recommend a diagnostic arthroscopy in cases older than three months prior to proceeding with an osteotomy.

Surgical Technique

The surgical technique is similar to a standard wrist arthroscopy save that irrigation fluid is not used during the procedure. It is of note, however, that this technique is more cumbersome and complicated than the average wrist arthroscopy. First, it requires an open exposure of the distal radius for plate fixation of the fragments in addition to the arthroscopic–assisted osteotomy. Second, it requires alternating the hand from a suspended position to flat on the operating table. Third, fluoroscopy is used periodically during the procedure—which is facilitated by placing the hand flat. The osteotomes and probes used need to be sturdier than the average arthroscopic instruments (Figure 18.1).

FIGURE 18.1 Instrumentation required for the procedure (from left to right): impactor, osteotome, strong-angled curette, shoulder probe, and small-joint arthroscopic guide.

Finally, the assistance of another experienced surgeon is integral to the procedure (Figure 18.2). It is important that everyone on the surgical team be prepared and familiar with their assigned role in order to minimize operating time. It is helpful for the surgeon to preplan the osteotomies beforehand based on a review of the preoperative X–rays and if possible of the original fracture films. The author has found a good–quality preoperative CT scan to be invaluable, since the intraoperative view of the joint can be quite confusing due to the disruption (Figure 18.3).

FIGURE 18.2 Set-up. The first surgeon is controlling the reduction, and the second surgeon is stabilizing the reduction by introducing the distal pegs on the plate. (A) Resident is holding the camera (assistant). The first surgeon has in front the arthroscopic tower and the fluoroscopy display.

FIGURE 18.3 Preoperative CAT scan of a C3.1 fracture. (A) A 3.5-mm step-off on the scaphoid fossa (A = anterior fragment; PC = postero-central). (B) Corresponding axial view of the same case, showing a multipiece fracture. The styloid (S), postero-central (PC), and a small (I) intermiddle fragment are depressed, in relation to the anterior fragment (A) and the postero-ulnar fragment (PU) (see C). (C) Coronal CATscan showing the depression of the styloid (S) and posterocentral (PC) in relation to the postero-ulnar (PU) and anterior (A) fragments. Only the former will require correction.

(From Piñal F, et al. Dry arthroscopy of the wrist: surgical technique. J Hand Surg 2007;32A:119–23.)

The arm is exsanguinated with an Esmarch bandage and the tourniquet elevated to 250 mmHg. Prior to suspending the hand, the skin incisions for the proposed site of plate fixation are prepared with the arm lying on the hand table. A limited volar ulnar incision is used for a volar ulnar shearing type of intra–articular mal–union. A limited Henry approach is used in the case of a mal–united radial styloid fragment or multifragmented mal–union. A plate is then pre–placed and held in position with a single screw through its stem.

The hand is then placed on traction from a bow with a custom–made system that allows one to easily change the hand from a horizontal to a vertical position while maintaining a sterile field.¹¹ The standard 3−/,4 and 6–R portals are developed. Transverse 1–cm skin incisions are preferred on the dorsum of the wrist because they heal with a minimal scar. To avoid lacerating any nerve or tendon, a superficial skin incision is made with a #15 blade. A hemostat is used to widen the portal to permit the smooth entrance of the osteotomes and other necessary instruments (Figure 18.1). Apart from dorsal portals, a volar radial (VR) portal is always used. If a Henry incision is planned, the portal is developed as recommended by Levy and Glickel.¹⁵ Otherwise, we follow the technique of Doi et al. or of Slutsky^16,17 (Figure 18.4). The quality of the articular cartilage over the adjacent scaphoid and lunate is assessed along with exploration of the midcarpal joint if there is any doubt as to the integrity of the interosseous ligaments.

FIGURE 18.4 The osteotomy is being performed through the volar radial portal while the assistant is holding the camera. Often at the same time surgeon 2 is directing the osteotomy through a dorsal 3-4 portal.

Initially, a 2.7–mm scope is introduced through the 3−/,4 portal and the joint palpated (for this we prefer the stronger shoulder probe). The consistency of the cartilage, and the presence and location of steps are assessed. A shaver can be helpful to remove the synovitis and fibrin, which is always present and obscures the view (2.9–mm incisor blade; 2.9–mm barrel abrader, Dyonics, Smith & Nephew, Inc., Andover, MA, USA). Air should flow freely into the joint when the suction of the synoviotome or bur is working. Otherwise, the suction will suck the capsule in and obscure the view. Sufficient air enters through the side tube of the arthroscope’s sheath. The surgeon should keep the valve open throughout the procedure.

Once major cartilage destruction has been ruled out, and the fragments to be mobilized are defined, the scope is moved to the 6–R portal (the 3−/,4 and VR portals are used for instrumentation). For cutting the fragments, we use periosteal elevators that are commercially available for shoulder surgery (Artrex AR–1342–30 degrees and AR–1342–15 degrees, Artrex, Naples, FL, USA). These elevators have a width of 4 mm and are strong enough to cut the fragments by gently tapping with a hammer. Recently, we have incorporated straight and curved osteotomes (Artrex AR–1770 and AR–1771) that can also be helpful because their different shapes are ideally suited to following the irregular shape of fracture lines. To avoid the risk of lacerating extensor tendons when introducing the osteotomes through the 3−/,4 portal, the blade of the osteotome should be gently introduced parallel to the tendon under direct visual control and then rotated while inside the joint. Gentle maneuvers are necessary, as there is a risk of cutting tendons if plunging volarly or dorsally.

The displaced fragments are fully mobilized by carefully prying them apart with the osteotome. In most cases, the fragments are disimpacted and easily elevated by hooking them with a strong shoulder probe and pulling upward. On one occasion, we have had to resort to elevation of a fragment from the outside with the use of a Steinmann pin introduced into the exact spot and advanced through a small arthroscopic guide (Ref 4291, Dyonics, Smith & Nephew, Inc., Andover, MA, USA).

Often, scar and new bone formation between the fragments impede reduction. This early granulation tissue should be resected with the help of small curettes or burs introduced through the portals. Once the reduction is acceptable (Figure 18.5), one surgeon maintains the position of the fragments while the assistant inserts the distal locking pegs in the plate. This step may be difficult because the flexor carpi radialis (FCR) and digital flexors are under tension (due to the traction) and impede insertion of any ulnar screws in the plate. This step is facilitated by backing off the wrist traction sufficiently to allow tendon retraction by insertion of a Farabeuf retractor. A compromise must be made in order to prevent a complete collapse of the radiocarpal space.

FIGURE 18.5 Correction of a step-off in the patient shown in Figure 18.2. In the right wrist, the arthroscope is in 6-R (at the very far upper left corner is the styloid). (A) Step-off on the scaphoid fossa. (B) The osteotome (entering the joint through the volo-radial portal) is separating the mal-united fragments. (C) Corresponding view after reduction.

(From Piñal F, et al. Dry arthroscopy of the wrist: surgical technique. J Hand Surg 2007;32A:119–23.)

Once the articular fragments have been secured under arthroscopic control, the hand is laid flat on the operating table and the rest of the screws are inserted in the plate. The type of fixation depends on the configuration of the mal–union. In one case, we used a single screw to secure a volar ulnar fragment. In another, a 2.7–mm buttress plate was used to stabilize a styloid fragment. In the most common situation (in which there are four or more fragments), a plate with locking distal pegs is preferred (DVR, Hand Innovations, Miami, FL, USA).

The hand is again suspended under traction for a final inspection of the articular surface. The joint is then irrigated with 10 to 30 cc of saline introduced through the scope’s side tube, and a shaver is used to remove all debris. Fluoroscopy can be used repeatedly throughout the procedure by releasing the hand from the traction bow.¹¹ Some authors find it easier to perform wrist arthroscopy with the hand lying flat on the table, but we have no experience with this technique.¹⁸

The portals are closed with paper tape or a single stitch, and the wrist is placed in a removable splint. In all our cases the fixation was sufficiently stable as to start protected range of motion on the first postoperative visit (48 hours).

Practical Tips

The entire operation can be carried out in less than 2 hours of tourniquet time, provided the surgeon is familiar with the “dry” technique of wrist arthroscopy and the assistants are well prepared and efficient. Presently, we perform virtually all of our arthroscopic procedures (such as ulnar head recession and ganglion removal) without fluid. The advantages are many: no fluid extravasation through the portals, no air bubbles or sudden loss of vision, no risk of compartment syndrome, less postoperative swelling, and presumably less pain.

From a practical point of view, the lack of extravasated fluid allows one to easily define the tissue planes during an open approach to the distal radius. One disadvantage is the learning curve that comes with mastering any new technique. A frequent frustration of the dry technique is the frequent loss of vision from blood or soft–tissue splashes. Valuable time is lost by removing the scope for cleaning each time this occurs. There are several tricks to maintaining visual access that should be kept in mind.^10,11

Results

The technique presented in this paper is drawn from experience in four patients with nascent intra–articular mal–unions of relatively short duration (five weeks to three months), with a follow–up of 18 days to 6 months. Two patients had a single fragment mobilized (one anteromedial fragment, one styloid fragment). The other two patients had two or more fragments mobilized (both C31 fractures of the AO classification) (Figures 18.6 and 18.7). Gaps of less than 1 mm were unavoidable after the operation due to a preexisting loss of cartilage and early granulation tissue, but intra–articular steps were reduced to 0 mm (from a maximum of 5 mm).

FIGURE 18.6 Same patient as in Figures 18.2 and 18.3. (A) Preoperative X-ray (depressed fragments highlighted by black dots). (B) Restoration of the articular line (six weeks).

(From Piñal F, et al. Dry arthroscopy of the wrist: surgical technique. J Hand Surg 2007;32A:119–23.)

FIGURE 18.7 Results of the same patient after six months.

It may be argued that fragments may be more easily defined early on by simply breaking the external callus. Based on the experience of our group and others, however, impacted cartilage containing fracture fragments is soundly healed by as early as three to four weeks and needs to be redefined with the use of an osteotome.^19,20 Piecemeal fragmentation can occur if the mobilization is not done carefully. Herein lies the advantage of the procedure. The arthroscope allows us to follow the exact line of chondral fracture under magnification, and to restore the anatomy of the cartilaginous surface.

The inside–out technique is a minimally invasive technique that allows full assessment of the articular deformity, a more precise osteotomy, and mobilization of the displaced fracture fragments. Even irregular fragments, not amenable to other techniques, can be dealt with by this procedure. Correction of step–offs was achieved in every case with an accuracy of 0 mm. Residual gaps of about 1 mm were common due to cartilage loss, interposition of newly formed bone, and presumably cartilage destruction from the original injury. The procedure can be incorporated easily by any surgeon familiar with arthroscopy.

Acknowledgments

Gratitude goes to Mr. Robert Jenkins for help with the English translation of this chapter.