Indications

The ideal candidate for low-profile dorsal plating is a patient with a multifragmented dorsally displaced fracture of the distal radius with dorsal bony defects, due to a high-velocity injury or the presence of osteoporosis. The indications include unstable fractures that have previously undergone closed reduction and splinting with unsuccessful reduction or loss of reduction. This includes extra-articular fractures (AO type A), intra-articular shear fractures (AO type B), and comminuted intra-articular fractures with metaphyseal comminution (AO type C). Some authors use the criteria of more than 20 degrees of dorsal angulation, radial shortening of more than 2 mm, or articular incongruity between 1 and 2 mm.⁶ The age range of patients for the procedure encompasses adolescents at the age of closure of the epiphyses to those in their nineties. It is often better to wait 5 to 7 days after injury to treat these fractures if there is no neurologic or vascular compromise. The reasons are better visualization of the fracture fragments, stabilization of health situations, decrease in the edema of the wrist and fingers, and better understanding of the procedure by patients and their families. We have used the dorsal plates in all types of fractures of the distal radius, including complex intra-articular multifragmented fractures, classified as C1, C2, and C3 by the AO classification system. In C3.3 fractures there might be a call for additional stabilization of the radius shaft fracture component, and we obtain reduction with extra screws taken from the distal radius set or an occasional Kirshner wire.

Contraindications

The only absolute contraindication to dorsal fixation is a distal radius fracture with a large volarly displaced fragment, especially one with minimal dorsal defects. In that case the volar approach is clearly indicated. Relative contraindications have to do with the health status of the patient, which can commonly be corrected during the 7- to 10-day waiting period. Anticoagulation in the elderly always presents a challenge if the patient is on Coumadin or other drugs, so an internal medicine, cardiology, or neurology consultation should be obtained to manage those situations.

Surgical Technique

Under general or brachial block anesthesia, the forearm is prepped and draped to the elbow area. A fluoroscopy preliminary film is obtained to confirm the deformities and the initial impressions. Following that, traction is applied to the index and ring fingers by Chinese finger traps with cords that are attached to a traction apparatus clamped to the operating-hand-procedure side table (Schlein Hand Positioner with rail attachment; Allen Medical Systems, Acton, MA) (Fig. 10-1). In case of doubt and in severe multifragmented fractures, the fluoroscopy film is repeated after traction has been applied. This is a very useful maneuver because in some situations the real severity of the comminution is revealed in this post-traction film rather than in the resting position.

FIGURE 10-1 Setup for open reduction of distal radius fractures with traction apparatus in place.

Under tourniquet control, a 5- to 6-cm dorsal longitudinal incision is made spanning the wrist joint and the distal forearm and deepened to the extensor retinaculum. The third dorsal space is incised obliquely following the direction of the extensor pollicis longus (EPL) tendon (Fig. 10-2). A hematoma is often present in the third dorsal space, and the identification of the tendon direction is facilitated by the presence of blood. At this point, we also open the second dorsal space longitudinally, exposing the extensor carpi radialis longus and brevis and freeing the tubercle of Lister. One of the interesting findings in severely comminuted fractures is that the EPL tendon can be caught between the displaced fracture fragments, and one has to extricate the tendon from the fragments (Fig. 10-3). In those cases, immediate visualization of the tendon is not easy and the surgeon might have to look for the tendon more distally and follow it to the fracture site. That happens in 2% of cases, in our empirical observation, but it is significant because traction applied to the hand and wrist will push the tendon farther into the separation between the fragments, making the reduction of the fracture impossible prior to dissection and extraction of the tendon. This situation would be impossible to recognize if such a fracture were being treated using the volar approach.

FIGURE 10-2 Exposure of the fracture through incision of the third dorsal space following the tendon of the extensor pollicis longus (epl).

FIGURE 10-3 Tendon of the extensor pollicis longus (epl) caught between fracture fragments (Fragment) in a severely comminuted, dorsally displaced fracture of the distal radius.

If the radial fracture fragment is translated toward the radial side and it involves a large portion of the radius styloid, it may not be reducible by traction alone. In these situations, we perform a tenotomy of the brachioradialis tendon as it inserts into the displaced fragment. The first dorsal space tunnel is incised and the contents are exposed. At the floor of that space, one can encounter the tendon of the brachioradialis, which is separate from the extensor pollicis brevis and the abductor pollicis longus.¹⁰ The brachioradialis tendon is tenotomized transversely, which greatly facilitates the reduction maneuvers for that fragment (Fig. 10-4).

FIGURE 10-4 Tenotomy of the brachioradialis tendon (BR) exposed through the first dorsal space.

The dorsal capsule is kept intact if at all possible. It is opened only in the rare instances in which there is a loose dorsal piece of the distal radius that has sheared off the articular surface, and we deem it important to the stability and congruity of the joint. In those cases we use an extender provided in the Locon-T set to capture the fragment.

In sequence, a wide periosteal elevator is used to elevate the periosteum together with the floor of the fourth dorsal space, therefore avoiding entering the space and exposing the finger extensor tendons. With that maneuver, the fracture is completely exposed. Sometimes fragments are still not visualized well enough and they have to be dissected further with a scalpel. Lister’s tubercle can be very prominent, and when that is the case, a rongeur is used to remove the dorsal part of the tubercle. A potential pitfall here is that in an osteopenic patient with multiple fragmentations, it is possible to remove one of the fragments together with the part of the tubercle that is being intentionally removed. Caution and a very shallow resection are strongly advised.

Usually in an elderly patient there is a large bone defect in the dorsal aspect of the radius (Fig. 10-5). For many years now, we have been using iliac crest bone allograft chips previously reconstituted in saline to fill this void (Fig. 10-6). The bone chips are excellent in this situation because they provide internal support and augment the bone stock, preventing collapse of the distal fragments.

FIGURE 10-5 Large dorsal defect usually found in distal radius fractures in elderly patients.

FIGURE 10-6 Bone allograft chips are applied to the dorsal defect, augmenting the bone stock and increasing internal support.

A dorsal plate is chosen according to the size of the radius and the side affected, and it is temporarily applied to the reduced fracture. Usually we use Locon-T plates because they fit the fractures well, have variable sizing, and are malleable. The other plate that we have used is the Stryker plate, which has the advantage of having locking screws; therefore it is used in situations in which there is great comminution in a severely osteoporotic patient. Nevertheless, the Stryker plate is somewhat bulky and stiff, making it less versatile (Fig. 10-7).

FIGURE 10-7 Stryker distal radius plates in place.

With the Locon-T plate, one can choose a small, medium, or large size. The large is rarely used except in tall men. Most of the time, the small size fits women and smaller men comfortably. The radial side of the plate invariably has to be bent using one of the benders provided in the tray. This is easily accomplished because of the malleability of the plate. The pitfall is to forget this step and at the end of the proximal fixation realize that the extensors of the wrist are caught beneath the plate.

The position of the plate is chosen under fluoroscopy. One of the advantages of the Locon-T plate is that it can be positioned all the way to the edge of the dorsal radius distally to treat a shearing fracture that does not have a large distal fragment. Once the size and position of the plate have been established, the first screw is applied. Often the plate is separated from the bone by a couple of millimeters, and placement of the first screw brings the plate into intimate contact with the dorsal cortex. One should be able to estimate the length of the screw to be applied by subtracting the cortex/plate separation ahead of time; otherwise the first screw will be too long and have to be replaced later. The first 3.5-mm screw is placed in the oblong screw hole, which is located in the shaft portion of the plate. Another film is obtained after the placement of the first screw so as to demonstrate the new position of the plate after tightening the screw. Often we have to move the plate distally or proximally when distal fragments are pushed volarly by the first screw and plate. Therefore, in most cases it is wise to place the first screw in the middle of the oblong hole so that one has the leeway to move the plate either way, if necessary (Fig. 10-8).

FIGURE 10-8 Locon-T; first screw applied.

Following that, the proximal shaft screws are drilled with the provided 2.5-mm drill, measured, and applied. These are 3.5-mm self-tapping screws. Measuring the screws in the proximal fragment is easy because most of the time the volar cortex is intact. Usually we do not place the most proximal screw into the plate because as a rule it does not add to the stability. Also, placing it requires a longer skin incision and more muscle retraction to expose the hole, which adds to the postsurgery morbidity.

The distal screws are applied at this time. Distal measurements can be a problem because of the poor quality of bone in the elderly and the comminution of the fracture. Added to that difficulty is the fact that the drill used distally is a 2-mm drill. Therefore, after the placement of the first 2.7-mm screw distally, a lateral film should be performed to determine whether the screw is of adequate size. The other screws are applied following that guideline (Fig. 10-9). As a very crude practical rule, the distal screws are roughly 4 mm longer than the most distal screw placed in the shaft; hence, an 18-mm distal shaft screw would correspond to a 22-mm distal fragment screw.

FIGURE 10-9 After fracture reduction, with screws applied, one screw hole was left empty because of the position of the fracture.

After all screws have been applied distally, assessment of the final fixation is made. Sometimes a small intra-articular dorsal fragment is left unsecured after the plate has been applied. In those cases we use the small extender that is provided in the tray. This extender fits distally and it has two holes, one that attaches to the plate with a regular 2.7-mm screw and one that is placed on top of the unsecured fragment and accepts a 1.8-mm screw. The extender can be attached to any dorsal screw hole and has helped on many occasions to secure a central fragment (Fig. 10-10) or a fragment in the radial or ulnar side of the distal radius (Fig. 10-11).

FIGURE 10-10 Plate extender (Extender) in place, securing a small, centrally located fracture fragment.

FIGURE 10-11 Radiograph of Locon-T plus extender (Extender) securing radially placed dorsal fragment.

After placement of all screws, final films are obtained, and the extensor retinaculum is closed partially, leaving the EPL free dorsal to the repair. Skin is approximated using horizontal mattress sutures of 5-0 nylon, and a large dressing and a volar splint are applied. A typical moderately severe case is illustrated in Figures 10-12 through 10-16.

FIGURE 10-12 Radiograph of a typical fracture of the distal radius, posteroanterior view, with intra-articular component, multiple fragments, and shortening of more than 5 mm.

FIGURE 10-13 Radiograph, same fracture, lateral view with greater than 20 degrees of dorsal displacement.

FIGURE 10-14 Postsurgery fluoroscopic posteroanterior view of typical fracture.

FIGURE 10-15 Postsurgery fluoroscopic lateral view of typical fracture. Notice that no screws were applied in the most proximal hole.

FIGURE 10-16 Postsurgery fluoroscopic view of typical fracture: 30-degree oblique lateral articular view.

Rehabilitation

Virtually all patients whose distal radius fractures are reduced surgically are treated as outpatients. The dressing is changed 2 days later in the office and a plaster splint is applied. The postsurgical regimen consists of immobilization for 3 weeks in a splint or cast. Range of motion exercises in the hand therapy department start after cast removal. We have attempted immediate mobilization as described in the literature⁴ but have found that patients tolerate the exercises better and experience less swelling and pain if the therapy is started at 3 weeks. Strengthening starts at 5 to 7 weeks, and the patients are reviewed for the last time prior to discharge at 3 months.

Complications

Aside from the usual complications related to residual stiffness of flexion-extension and pronation-supination that are inherent in any treatment of distal radius fractures, the complications to be expected from the dorsal approach are irritation of the extensor tendons by tendinitis and possible rupture and loosening of the screws.^1,9 Tendinitis has not been a major concern when plates are employed. After the insertion of more than 100 plates, only two patients experienced tendinitis—one 2 months after surgery and one 2 years after surgery. The second one may have had an intersection syndrome unrelated to the plate. Both of them were treated with rest and nonsteroidal anti-inflammatory drugs and responded well.

Screw loosening at the distal fragment is a slightly bigger problem with Locon-T plates; we have seen it happen in roughly 5% of patients. We have removed only two screws that were very prominent during the past 7 years of using the plate. No plate removals were necessary. In contrast, there has been no screw-loosening problem with the Stryker plate. It is therefore a better option for the very osteopenic patient. The design of the screw hole in the Stryker plate permits locking with no increase in the profile and allows for locking the screws at various angles, which is a distinct advantage in situations where poor bone stock or a lot of comminution is present.

Other complications have to do with poor choice of the approach by the surgeon. If the volar fragment is bigger than the dorsal one, this approach should be avoided because the screws placed from the dorsal side will not be able to capture the volar fragment and reduce it satisfactorily. We have had at least three patients in the past 7 years who fell into the category of being poor candidates for the approach and suffered fracture collapse. One of them ended up having a radiocarpal fusion 1 year after surgery because of continued pain. The other two had no residual pain and they chose to accept the deformity without correction.

Results

We studied 28 consecutive patients (24 women and 4 men) who had severe distal radius fractures, were treated using the Locon-T dorsal plate, and underwent a follow-up of 3 years. All procedures were performed on an outpatient basis. The criteria for patient selection were as follows:

The objectives of our treatment were:

The results were measured initially at 3 months, when the patients were discharged from therapy. The patients were recalled at 36 months and re-examined. Flexion-extension and pronation-supination figures were compared to two articles in the literature—one utilizing dorsal and volar approaches (Jupiter and colleagues¹¹) and one employing a volar approach only (Orbay and colleagues⁴). These articles referred to 20 patients measured at 38 months and 26 patients measured at 16 months, respectively. The comparison is illustrated in Table 10-1.

Grip strength varied from 38 lb to 75 lb, and that corresponded with 84.4% to 150% (mean 92%) of the contralateral side. The lower percentage grip strength corresponded with a fractured nondominant wrist.

The postoperative radiologic evaluation did not show any loss of radius height or articular congruity from the 3-month mark to the 36-month re-evaluation. We strive mostly for radius length in comparison to tilt or intra-articular congruity, and we tend to accept zero degrees of tilt during the reduction as a successful result. The traction plus the addition of bone allograft makes that position readily achievable, and in the elderly it translates into ultimate good function. Therefore, our postoperative radiologic examinations take that fact into consideration. Even so, all radiologic evaluations showed a range of 0 degrees of volar tilt to 4 degrees; no ulnar-positive variance (except in one case that showed postoperative collapse due to poor indication of the dorsal approach) and less than 2 mm of articular incongruity in all cases.

Additional Comments

We have been using bone allograft chips in addition to the plate to create an internal support structure in these situations, with the goal of increasing the bone stock and helping the stable fixation of these fractures. It is our experience that the low-profile plates that are used in the distal radius area do not interfere severely with gliding of the extensor tendons.

Because the approach is simple and relatively quick, there is no justification for doing lesser procedures in the elderly with the excuse of saving anesthesia time. Our tourniquet time has ranged from 37 to 45 minutes in the past 70 cases. This is less time than is required for other approaches in our hands, except for closed pinning without the addition of bone graft, which has been abandoned because it is unreliable in the elderly.⁸ Our surgical time corresponds with the experience of one surgeon (RSC) and is in sharp contrast to the reported tourniquet times of 105.3 minutes for dorsal plating with Pi plates reported by Grewal and colleagues.⁹ Their study included six orthopaedic surgeons, and the reported tourniquet times may reflect variables other than simply the dorsal approach and plate design.

The fracture treatment time interval limit for the procedure is about 2.5 weeks in patients who are 50 years old or younger and 3.5 weeks for older patients. After that period of time, the surgery can still be performed, but it will take other maneuvers such as osteotomies to accomplish acceptable results.

None of my patients has suffered from sympathetic dystrophy, even though one has had a presympathetic dystrophy condition that is characterized by an increase in swelling and discoloration of the skin, with a sudden increase in pain and decrease of motion (a “flare reaction”). Our very attentive hand therapist brought this patient to my attention early, and she was treated with an oral steroid dose pack and experienced an excellent response.

Conclusion

The dorsal approach to distal radius fractures is a viable option for patients with severe dorsally displaced fractures. This approach has fallen into disfavor during the past few years, but the advent of new low-profile plates promises to revive this procedure, especially in the elderly population. The advantages are:

The results are at least similar to those found when using the volar approach. Judging by the comparison, the results are better in terms of pronation-supination though slightly worse in terms of extension.