David J. Slutsky


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3475 Torrance Blvd., Ste F
Torrance, CA 90503


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Office hours: M-F, 9am – 5 pm

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In September 2008, we will be moving to a beautiful new 4,400 sq ft, state of the art dedicated hand center located at 2808 Columbia Ave in Torrance, CA., which will feature onsite nerve conduction studies, occupational hand therapy and digital x-ray.
 


PROCEDURES

EXTERNAL FIXATION OF DISTAL RADIUS FRACTURES

Introduction
External fixation has been used for the treatment of distal radius fractures for more than 50 years. Although the fixator configurations have undergone considerable modification over time the type of fixator itself is not as important as the underlying principles which provide the foundation for external fixation. Though volar plate fixation is currently in vogue, the indications for external fixation remain largely unchanged. Newer fixator designs have also expanded the traditional usage to include nonbridging applications which allow early wrist motion. The following discussion will focus on the myriad uses for external fixation as well as the shortcomings and potential pitfalls.

Anatomy
There are some important anatomical points one must bear in mind when considering external fixation of the distal radius. The articular surface of the radius is triangular with the apex of the triangle at the radial styloid. It slopes in a volar and ulnar direction with a radial inclination of 23° (range 13-30°), a radial length of 12 mm (range 8 - 18 mm) and an average volar tilt of 12° (1 - 21°). 1 The dorsal surface of the distal radius is convex and irregular and it is covered by the 6 dorsal extensor compartments. The dorsal cortex is thin which often results in comminution that may lead to an abnormal dorsal tilt. Lister’s tubercle acts as a fulcrum for the extensor pollicis longus (EPL) tendon which lies in a groove on the ulnar side of the tubercle. The volar side of the distal radius, which is covered by the pronator quadratus, is flat and makes a smooth curve which is concave from proximal to distal. When inserting the dorsal pins it is important to engage the volar ulnar lip of the distal radius where the bone density is highest, especially in osteopenic bone.2.

The dorsum of the radius is cloaked by the arborizations of the superficial radial nerve (SRN) and the dorsal cutaneous branch of the ulnar nerve (DCBUN). The SRN 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 styloid (Figure 1). Either partial or complete overlap of the lateral antebrachial cutaneous nerve (LABCN) with the SRN occurs up to 75% of the time. 3 The DCBUN arises from the ulnar nerve 6 cm proximal to the ulnar head and becomes subcutaneous 5 cm proximal to the pisiform. It crosses the ulnar snuffbox and gives off 3-9 branches that supply the dorsoulnar aspect of the carpus, small finger and ulnar ring finger. Open pin insertion allows identification and protection of these branches.

The proximal pins are placed at the junction of the proximal and middle thirds of the radius. At this level the radius is covered by the tendons of extensor carpi radialis longus (ECRL) and extensor carpi radialis brevis (ECRB) as well as the extensor digitorum communis (EDC). The proximal pins can be inserted in the standard midlateral position by retracting the brachioradialis (BR) tendon and the SRN, in the dorsoradial position between the ECRL and ECRB or dorsally between the ECRB and EDC which carries less risk of injury to the SRN. 4

Ligamentotaxis
External fixation of distal radius fractures may be used in a bridging or nonbridging manner. Bridging external fixation of distal radius fractures typically relies on ligamentotaxis to both obtain and maintain a reduction of the fracture fragments. As longitudinal traction is applied to the carpus, the tension is transmitted mostly through the radioscaphocapitate and long radiolunate ligaments to restore the radial length. In a similar vein, pronation of the carpus can indirectly correct the supination deformity of the distal fragment.

Limitations of ligamentotaxis
Ligamentotaxis has a number of short comings when applied to the treatment of displaced intra-articular fractures of the distal radius. Firstly, since ligaments exhibit viscoelastic behavior 5, there is a gradual loss of the initial distraction force applied to the fracture site through stress relaxation.6 The immediate improvement in radial height, inclination and volar tilt are significantly decreased by the time of fixator removal ( Figure 2 A, B). 7
Traction does not correct the dorsal tilt of the distal fracture fragment. This is because the stout volar radiocarpal ligaments are shorter and they pull out to length before the thinner dorsal radiocarpal ligaments exert any traction.8 Excessive traction may actually increase the dorsal tilt (Figure 3 A - C). 9 A dorsally directed vector is still necessary to restore the normal volar angulation. This is usually accomplished by applying manual thumb pressure over the dorsum of the distal fragment. With intra-articular fractures, ligamentotaxis reduces the radial styloid fragment but for the above reasons it does not reduce a depressed lunate fragment.10 When there is a sagittal split of the medial fragment, traction causes the volar medial fragment to rotate which often necessitates an open reduction. External fixation cannot control radial translation and cannot therefore be used with an unstable distal radioulnar joint (Figure 4 A, B).

Biomechanical considerations for External Fixation
Fracture site loads
External fixation is considered flexible fixation. 11 The biomechanical requirements of external fixation for fractures of the distal radius have not been ascertained since until recently, the magnitude and direction of the physiologic loads on the distal radius were dynamic and unknown. Recent work by Rikli et al however has shed new light on this point. 12 Using a new capacitive pressure-sensory device his group measured the in- vivo dynamic intra-articular pressures under local anesthesia in the radioulnocarpal joint of a healthy volunteer. With the forearm in neutral rotation, the forces ranged from 107N with wrist flexion to 197N with wrist extension. The highest forces of up to 245 N were seen with the wrist in radial deviation and the forearm in supination. Presumably any implant or external fixator would need to be strong enough to neutralize these loads in order to permit early active wrist motion. Rikli et al also identified 2 centers of force transmission. The first center was opposite the scaphoid pole, which would represent the radial column. The second center, which would represent the intermediate column of the wrist, took a considerable amount of the load and was opposite the lunate, extending ulnarly over the triangular fibrocartilaginous complex (TFCC).

Fixator frame rigidity
The strength of the fixator depends on the rigidity of the connecting rods and the clamps. Many external fixator rods are 0.5 to 1.0 cm in diameter, although radiolucent rods made from PEEK, Ultem or Carbon fiber may be larger. Increasing the diameter of the rods increases the rigidity by a factor of 4. Uniplanar fixators are common, but the rigidity of the construct can be increased by adding a second parallel rod. Placing the rod as close to the skin as possible also increases the stability against bending loads by reducing the lever arm from the neutral joint axis. Most distal radius external fixators use 3.0 or 4.0 mm threaded half pins. Modern threaded pins are hence designed with a larger core diameter and smaller core-thread diameter. If the pin threads are buried, the larger pin diameter at the near bone interface resists bending forces whereas the small core thread resists pull out forces at the far cortex. A bicortically inserted pin with a very short thread will provide the best pin-bone fixation. Theoretically, under drilling the pin hole by 0.1 mm provides the best pin fixation with the least risk of bone resorption and pin loosening. It is also desirable to spread the force evenly across the entire shaft of the bone by creating a wide separation of the fixator pins. In order to achieve stable fixation and reduce the lever arm of displacing forces, the pins should inserted close to the fracture site. One pin is hence inserted close to the fracture site while the second is placed as far away as possible. 13

Construct rigidity
Increasing the rigidity of the fixator does not appreciably increase the rigidity of fixation of the individual fracture fragments. 14 There are a number of ways however in which to augment the stability of the construct. After restoration of radial length and alignment by the external fixator, percutaneous pin fixation can lock in the radial styloid buttress and support the lunate fossa fragment. 15 A 5th radial styloid pin attached to the frame of a spanning AO (Synthes, Paoli, PA, USA) external fixator prevents a loss of radial length through settling and leads to improved wrist range of motion as compared to a 4-pin external fixator.16 The addition of a dorsal pin attached to a sidebar easily corrects the dorsal tilt found in many distal radius fractures.17, 18
K-wire fixation enhances the stability of external fixation. The combination of an external fixator augmented with 0.62 k-wires approaches the strength of a 3.5 mm dorsal AO plate (Synthes, Paoli, PA, USA). 19 Supplemental k-wire fixation is more critical to the fracture fixation than the mechanical rigidity of the external fixator itself.14 Stabilizing a fracture fragment with a nontransfixing K-wire that is attached to an outrigger is just as effective as a k-wire that transfixes the fracture fragments.20

Bridging External Fixation
Temporary external fixation: Indications

(Video: temporary external fixation)
As compared to conventional plate fixation, bridging external fixation may be used in a temporary manner or it may be used for definitive management of the distal radius fracture. Bindra has listed the following indications for this technique: 21
1. Initial management of severe grade open fractures with extensive soft tissue loss (Figure 5 A - C).
2. Temporizing measure to resuscitate a polytraumatized patient.
3. Pending transfer to a tertiary referral facility for definitive fracture management.
Rikli et al use temporary bridging external fixation for complex fractures to both aid in the provisional fracture reduction and to allow a better CT evaluation of the fracture characteristics prior to double plate fixation. 22

Definitive external fixation: Indications
1. Unstable Extra-articular distal radius fractures.
2. Two-part and selected 3-part intra-articular fractures without displacement.
3. Combined internal and external fixation.

Contraindications
Bridging external fixation should not be used as the sole method of stabilization in the following situations:
1. Ulnar translocation due to an unstable distal radioulnar joint.
2. Intra-articular volar shear fractures (Bartons, reverse Bartons).
3. Disrupted volar carpal ligaments / radiocarpal dislocations.
4. Marked metaphyseal comminution.

Combined index and middle finger metacarpal fractures preclude the use of this technique due to the interference with distal pin site placement.

Surgical Technique
The patient is positioned supine on the operating table with the arm abducted on an arm board. Finger traps with some type of traction either with weights and an overhead arm holder or an arthroscopy tower may be used unless the fixator has distraction capabilities. The use of a tourniquet facilitates pin insertion, but it is not mandatory, especially in the face of massive soft tissue swelling, vascular impairment or marked infection. The fixator is applied under fluoroscopic control. A 2 cm incision is made over the radial aspect of the index metacarpal base, although the middle finger metacarpal may be substituted. The interosseous fascia overlying the metacarpal is incised and reflected laterally. The extensor tendon(s) are identified and protected as well as branches of the superficial radial nerve. Homann spike retractors simplify soft tissue retraction. The fixator pin hole is pre-drilled with a smaller drill diameter to increase the friction fit. The pin is then inserted by hand to minimize the risk of thermal bone necrosis and subsequent pin loosening or infection. A double pin clamp or any supplied pin guides are then used to insert the second pin, parallel to the first pin. Pin convergence or divergence make double pin clamp application laborious, but does not interfere with single pin clamp application.

It is my preference to apply the distal pin clamp and provisionally attach the fixator frame in order to gauge the proper site for placement of the proximal pins. It is desirable to place the proximal pins near the mid-forearm since more proximal placement becomes exceedingly difficult due to interposed muscle and the branches arising from the posterior interosseous nerve. If the fixator is used to restore radial length, the distractor module should be prepositioned close to it’s starting point to allow the maximum potential amount of elongation. Alternatively, the fracture can be distracted with longitudinal traction which simplifies the fixator application. A 3 cm incision is made over the mid lateral line of the radius shaft. The brachioradialis tendon is identified and retracted along with the superficial radial nerve. The proximal pins can be inserted in the standard dorsoradial position or they may be inserted dorsally between the extensor carpi radialis brevis and extensor digitorum with less risk of injury to the superficial radial nerve. The pins holes are also pre-drilled and inserted by hand.
The fracture is distracted under fluoroscopic control. Overdistraction of the carpus should be avoided since this will lead to extensor tendon tightness and intrinsic muscle contraction. The wrist should be placed in neutral or slight extension. Full passive flexion of all of the fingers should be possible. The index is the most sensitive to traction and can be used to gauge this.

Complications
Fixator loosening with loss of fracture position can be avoided by periodically checking and tightening the fixator connections. Fixator failure by itself is uncommon but many commercially available fixators are approved for single use only due to the risk of unrecognized material fatigue or failure of any locking ball joints. Pin site complications include infection, loosening and interference with extensor tendon gliding. The risk of injury to branches of the superficial radial nerve mandate open pin site insertion. Bad outcomes associated with external fixation are often related to Over distraction. One biomechanical study documented the effect of distraction of the wrist on metacarpophalangeal (MCP) joint motion. More than 5 mm of wrist distraction increases the load required for the FDS to generate MCP joint flexion for the middle, ring, and small fingers. For the index finger, however, as much as 2 mm of wrist distraction significantly increases the load required for flexion at the MCP joint.23 Many cases of intrinsic tightness and finger stiffness that are attributed to reflex sympathetic dystrophy are a consequence of prolonged and excessive traction which can be prevented by limiting the duration and amount of traction and instituting early dynamic MP flexion splinting even while in the fixator (Figure 6).

The degree and duration of distraction correlates with the amount of subsequent wrist stiffness. 24 Distraction, flexion and locked ulnar deviation of the external fixator encourage pronation contractures (Figure 7). Distraction also increases the carpal canal pressure which may predispose to acute carpal tunnel syndrome 25 (Video: Overdistraction). Metaphyseal defects should be grafted to diminish bending loads and to allow fixator removal after 6-7 weeks which minimizes the fixator related complications.

Results

Margaliot et al performed a meta-analysis of forty-six articles with 28 (917 patients) external fixation studies and 18 (603 patients) internal fixation studies. They did not detect a clinically or statistically significant difference in pooled grip strength, wrist range of motion, radiographic alignment, pain, and physician-rated outcomes between the 2 treatment arms. There were higher rates of infection, hardware failure, and neuritis with external fixation and higher rates of tendon complications and early hardware removal with internal fixation. Considerable heterogeneity was present in all of the studies which adversely affected the precision of the meta-analysis.26
Westphal and colleagues performed a retrospective comparative study of 166 out of 237 patients who underwent surgery for AO/ASIF A3 or C2 distal radius fractures. The fractures were treated with either external fixation or open reduction and internal fixation using palmar or dorsal plates. Open reduction and internal fixation, in particular palmar plate fixation, demonstrated the best radiological and functional results.27 External fixation falls short when used as the sole treatment for displaced intra-articular fractures. In a study of 27 patients with comminuted, displaced intra-articular fractures of distal radius that were treated exclusively by external fixation, Arora and co-authors concluded that although the external fixation is reliable in maintaining the reduction in displaced comminuted intra-articular fractures, it is inadequate in restoring articular congruity in many cases.28

Augmented External Fixation
The use of supplemental k-wire fixation can expand the indications for external fixation. As noted above, k-wire fixation not only enhances the reduction of the fracture fragments but also increases the rigidity of the entire construct. Many authors have stressed the importance of using the external fixator as a neutralization device rather than a traction device. Ligamentotaxis is used to obtain a reduction of the fracture fragments, which is then captured with percutaneous k-wire fixation. The traction on the fixator can then be reduced, which allows positioning of the wrist in neutral or slight extension (Figure 8). 9 This serves to reduce extensor tendon tightness and facilitates finger motion. In a study of intra focal pinning, Trumble and colleagues noted that In patients over 55 years of age and younger patients with comminution involving two or more surfaces of the radial metaphysis (or > 50% of the metaphyseal diameter) bridging fixation was necessary in addition to percutaneous pin fixation to prevent late fracture collapse.29 In 4-part fractures where there is a sagittal split of the medial fragment longitudinal traction accentuates the palmar translation and rotation of the volar medial fragment (Figure 9 A - E). Dorsal to volar k-wire placement carries the risk of injury to the volar neurovascular bundles especially with k-wire migration. For these reasons any sagittal split of the articular surface typically requires open treatment. 30 (Video: Volar rim fracture with DRUJ instability)


Indications
1. Intra-articular radial styloid fractures.
2. Three 3 -part intra-articular fractures.
3. Following percutaneous reduction of a depressed lunate fragment.
4. Arthroscopic aided reduction of distal radius fractures.

Contraindications
1. Marked metaphyseal comminution.
2. Volar/dorsal intra-articular shear fractures.
Surgical Technique (3-part intra-articular fracture)
(Video: Fragment Specific Fixation)

The technique is similar to that of straight forward external fixation. A 1 cm incision is made over the radial styloid and the superficial radial nerve branches and the thumb extensor tendons are retracted. Using a drill guide, an oblique and a horizontal subchondral 0.62 mm k-wire are pre-positioned in the radial styloid fragment under fluoroscopic control. Ligamentotaxis is used to obtain a reduction of the radial styloid fragment. The k-wire is then driven obliquely across the radial styloid fragment to capture the reduction and engage the proximal ulnar shaft. A small dorsal incision is made underneath the medial fragment and a free elevator is used to elevate a depressed articular fragment and to correct any abnormal dorsal tilt. The reduction is then captured by advancing the subchondral k-wire. Care is taken to prevent penetration of the DRUJ, which can be detected by DRUJ crepitus with passive pronation and supination. Once the reduction is obtained the traction is diminished and the fixator is applied as described above. The wrist is then positioned in neutral or slight extension. The index extensor tendon is the most sensitive to traction. Since ligamentotaxis is no longer crucial to maintain the reduction, the traction is reduced until full passive combined flexion of the index MP, PIP and DIP joints is easily obtained. Any metaphyseal bone defect is then grafted percutaneously through a small dorsal incision. If desired, percutaneous 3.0 mm screws can be substituted for the k-wires (Figure 10 A - J).

Results
Kreder et al compared the results of open reduction and internal fixation (ORIF) v.s. external fixation and pinning. A total of 179 adult patients with displaced intra-articular fractures of the distal radius were randomized to receive indirect percutaneous reduction and external fixation (n = 88) or ORIF (n = 91). There was no statistically significant difference in the radiological restoration of anatomical features or the range of movement between the groups at 2 years. The patients who underwent indirect reduction and percutaneous fixation however had a more rapid return of function and a better functional outcome than those who underwent ORIF, provided that the intra-articular step and gap deformity were minimized.31

Grewal and co-authors noted the superiority of external fixation and k-wire fixation over internal fixation with a dorsally placed Pi plate for displaced intra-articular fractures of the distal radius. The plate group also had higher levels of pain at 1 year when compared with the external fixator group; however, this equalized after hardware removal. The external fixator group showed an average grip strength of 97% when compared with the normal side v.s. 86% in the dorsal plate group.32

Complications
In one study of 70 cases of external fixation and percutaneous pinning, 49% of cases lost more than 5 degrees of volar tilt following reduction at the 6 month follow up despite the use of pinning. Initial deformity, patient age, use of bone graft, and duration of external fixation were not predictors of loss of reduction. No specific predictor of loss of reduction was noted, although there was a trend toward a loss of reduction in younger patients. 33

Nonbridging External Fixation
Bridging fixation does not lend itself to early wrist motion. Efforts to dynamically mobilize the wrist with joint spanning fixators have been largely unsuccessful. This is related to the difficulty in reproducing the complex kinematics of the carpus as well as the inability of the fixator to maintain ligamentotaxis throughout the entire arc of motion.34, 35 Good results have been achieved with nonbridging fixation of extra-articular distal radius fractures, which does allow early wrist motion. The final wrist range of motion and grip strengths are superior to those attained with bridging external fixators.36, 37

Extra-articular Fractures
Indications

Nonbridging external fixation is indicated in any extra-articular fracture where there is a high risk of late collapse (Figure 11 A – H) or if there is redisplacement of the fracture following an acceptable closed reduction ( Figure 12 A – M). Lafontaine et al identified a number of risk factors that were associated with secondary fracture displacement despite a satisfactory initial reduction. These included the presence of dorsal tilt > 20°, comminution, intra-articular involvement, an associated fracture of the ulna and age greater than 60 years. If three or more of these factors were present there was a high likelihood of fracture collapse. 38 When there is significant displacement on the injury films, there is a high likelihood of collapse even if the initial reduction is satisfactory. Trumble recommends supplemental internal and/or external fixation in younger patients for fractures with > 2 mm of radial shortening and >15 °of dorsal tilt following a closed reduction, especially if there is comminution of 2 or more cortices.39 Although this is easier if done early on, the fracture site can be still be freed up with a percutaneous elevator as late as 3 weeks which then allows a reduction of the distal fragment using the dorsal fixator pins.

Contraindications
Nonbridging external fixation is contraindicated when the distal fragment is too small for pin placement. At least 1 cm of intact volar cortex is required for pin purchase. Dorsal comminution does not preclude a successful result. This technique is not applicable to volar displaced or volar shear fractures and in children with open epiphyses. 40

Surgical Technique (Video: Nonbridging Extra-articular fracture)
The technique is similar to bridging external fixation, with the use of a tourniquet and intra operative fluoroscopy, but a traction tower is not required. Two dorsal 3.0 mm pins are inserted in the distal fragment through separate longitudinal incisions. The pins can be placed on either side of Lister’s tubercle or the EPL tendon, as well as between the EDC and the extensor digit minimi (EDM). The starting position of the pin should be approximately halfway between the fracture and the radiocarpal joint. A temporary k-wire can be used to gauge the proper angle. The first pin is inserted through Lister’s tubercle parallel to the joint surface in the lateral plane until it engages the volar cortex. The second dorsal pin is inserted in a similar manner but on the ulnar side of the EPL or EDC tendons. The dorsal tilt is corrected by levering the pins distally until the normal volar inclination has bee restored. The fixator frame is then applied and tightened.

Complications
Pin pullout due to fracture of the distal fragment can occur if the distal fragment is too small or osteopenic, or if the reduction is too vigorous. If this occurs the fixator can be converted to a bridging construct. An incomplete reduction is also possible, especially with nascent malunions. Over-reduction of the fracture can also occur, especially when there is volar comminution.

Results
McQueen et al performed a prospective study of 641 patients with unstable fractures of the distal radius treated with external fixation. Fifty-nine percent of these cases were treated with nonbridging external fixation, mostly in AO type A3.2 and C2.1 fractures. Patients treated with nonbridging external fixation had statistically significant better radiological results throughout the period of review. In particular this technique consistently restored the volar tilt and carpal alignment. Radiological improvement was mirrored by functional improvement. Most functional indices were statistically better at an early stage whereas; wrist flexion and grip strength remained significantly better at the final review. Complication rates were similar between the two groups.40

Intra-articular Fractures
Early wrist motion following intra-articular fractures provides a number of possible benefits including diminished stiffness, stimulation of cartilage repair 41 and decreased osteopenia of the distal fragments. 42 In order to accomplish this with nonbridging external fixation, the construct must be able to withstand the forces generated during active and passive wrist motion.

Biomechanical considerations
The author undertook a biomechanical study to examine the feasibility of nonbridging external fixation of simulated 3 and 4 part intra-articular fractures.43 The study was performed in 3 phases. In the first phase, this method was tested in a 3-part intra-articular fracture model using either 1 or 2 external fixators applied in a nonbridging fashion. Five fresh frozen cadaver arms underwent biomechanical testing using single and double nonbridging fixator configurations. During the second phase the maximum static force that could be withstood during simulated passive assisted wrist extension and simulated gripping without causing articular displacement in a 4-part fracture model was examined in 8 cadaver arms. All of the fractures were stabilized using a single custom nonbridging external fixator which has an integrated dorsal sidearm (the Fragment Specific fixator, South Bay Hand Surgery LLC, Torrance, CA) (Figure 13 A). third phase we examined the effects of cyclical loading on a 3 part intra-articular fracture model with dorsal comminution as described by Dodds et al. 44 All of the fractures were stabilized with the Fragment Specific fixator (Video: Fixator Biomechanics ).

The specimens were mounted vertically with an 89 N preload (20 lbs) 45 applied via gravity traction by hanging 5 lb metal plates from the wrist tendons. Active wrist motion was simulated by manually ranging the wrist through a complete flexion and extension arc. Passive assisted wrist motion was simulated by applying an additional load to the carpus with a servohydraulic materials testing machine (Instron 1321 Biaxial Hydraulic System). Gripping was simulated by direct axial loading of the lunate fossa. There was a wide variation in the stiffness of the constructs during phase I, II and III. Despite this fragment specific external fixation was able to maintain articular congruity with forces that exceed physiologic loading. The stiffness of the construct stabilized with the fragment specific fixator averaged 149 N in axial loading with an intact TFC and 117 N with a cut TFC. These values compared favorably with the stiffness data of 5 commercially available distal radius plates, which ranged from 95.5 N to 136 N.46 In the 3rd phase of the study there was no observable articular displacement in any of the wrists after 200 cycles of wrist flexion and extension with loads of up to 145 N. The study conclusion was that nonbridging external fixation with new fixator designs could be applied to the treatment of intra-articular fractures. Putnam et al have shown that for every 10 N of grip force, 26 N is transmitted through the distal radius metaphysis. They have recommended that the rehabilitation grip forces should be kept under 140 N with external fixation in order to prevent or minimize fixation failure. 47 This also appears to be a safe limit as it pertains to nonbridging external fixation as well.

When using the Fragment Specific Fixator, the 3.0 mm fixator pins are used in place of k-wires and have dual roles. They provide interfragmentary fixation but when attached to the fixator, they also act like blade plates to resist bending moments and buttress the fracture fragments The immediate subchondral position of the pins support the joint surface and is critical in maintaining articular congruity during fracture healing. Ligamentotaxis through joint bridging can be avoided, in order to allow early wrist motion. Similar to a fixed angle plate, the biomechanical rationale for the Fragment Specific Fixator is to transfer load from the fixed support of the articular surface to the intact radial shaft, bypassing any metaphyseal comminution (Figure 13 B) . Unlike a fixed angle blade plate, the fixator pin angle is freely adjustable so that it can be adapted to the fracture site plane which may diminish fracture malalignment.

Indications
Nonbridging external fixation is ideally suited for the treatment of 2- and 3-part intra-articular fractures of the distal radius provided there is good bone density and a stable DRUJ. It’s use following an arthroscopic-aided reduction and k-wire fixation of an intra-articular fracture permits early protected wrist motion although bridging fixation is warranted in the presence of marked articular comminution.

Contraindications
Volar and dorsal marginal fractures (Bartons and reverse Bartons) are excluded and should be treated with internal fixation. Fractures with extensive metaphyseal / diaphyseal comminution require supplemental internal fixation.
Surgical Technique using the Fragment Specific Fixator (Video: Nonbridging FSF C2)

Radial styloid reduction
With the aid of a traction tower the radial styloid fragment is reduced with ligamentotaxis under fluoroscopic control. Any excessive supination or radial translation of the distal fragment is corrected prior to pin insertion. The styloid may be held with a provisional .062 k-wire. An oblique 3.0 mm pin is then hand drilled at approximately a 45° angle from the tip of the radial styloid across the fracture site to engage the ulnar cortex of the proximal fragment. The pin is fastened to a single pin clamp attached to the distal fixator arm. A more proximal pin clamp is used as a drill guide for insertion of a horizontal styloid pin to both fixate and provide subchondral support for the lunate fragment. The k-wire can be removed or left in place for added support as necessary. Next two proximal pins are inserted in the mid-radius using the double pin clamp as a drill guide.

Reduction of dorsal tilt
The dorsal tilt can be corrected by using a Freer elevator inserted percutaneously in the fracture site after the radial styloid reduction. Alternatively the tilt can be corrected as described for the extra-articular fractures. In this case the radial styloid is reduced secondarily. Two dorsal 3.0 mm pins are inserted in the distal fragment through separate longitudinal incisions as described for the extra-articular fractures. The first 3.0 mm pin is inserted through Lister’s tubercle parallel to the joint surface in the lateral plane until it engages the volar cortex. The dorsal sidearm is positioned parallel to the joint space. A single pin clamp attached to the dorsal sidearm is fastened to this pin then both are locked in place. After the two proximal pins are inserted in the mid-radius, the distractor unit is used to lengthen the fixator until the volar tilt of the articular surface has been restored. An additional dorsal pin is inserted on the ulnar side of the EPL or EDC tendons using the 2nd single pin clamp on the outrigger bar as a drill guide. The radial styloid pins are then inserted as described above (Figure 14 A -M )

Protected wrist motion is allowed after the 1st week. If there is difficulty regaining supination, the patient is held in a long arm splint in supination in-between wrist motion exercises. The fixator is typically removed in the office at 6 weeks.

Caveats
Nonbridging external fixation of intra-articular distal radius fractures should be reserved for manually active patients with good bone quality without evidence of prior wrist arthritis. The lunate fragment must be sufficiently large to support two 3.0 mm pins. A CT scan with AP, lateral and coronal views is helpful to assess the fracture line patterns in order to aid pin insertion (Figure 15 A –N).

Complications
The immediate complications consist of injury to branches of the superficial radial nerve or dorsal cutaneous branches of the ulnar nerve. Loss of fixation due to poor pin placement or interference with extensor tendon gliding can be minimized by careful technique and open rather than percutaneous pin insertion. The use of many standard external fixator frames applied in a nonbridging manner can result in articular incongruity. Late collapse after fixator removal can occur in osteopenic bone which often requires subchondral support beyond the 6 weeks of fixator application Due to the risk of late collapse, adjuvant internal fixation with locking plates is advised in elderly and osteopenic patients since fracture site settling may occur for up to 6 months.33

Results
Reports of nonbridging external fixation (or radio-radial external fixation) for the treatment of intra-articular fractures are sparse and mostly restricted to the European literature. Krishnan et al reported a clinical trial of 30 patients with Frykman type 7 and 8 fractures who were treated with the Delta frame nonbridging external fixator (Mathys Medical Ltd., Bettlach, Switzerland).48 Although favorable wrist motion was reported, the median intraarticular step was 2.8 mm (range 0-9.1 mm) with a median intra-articular gap of 1.8 mm (range 0-13.4 mm).42 Gradl et al examined 25 consecutive patients with fractures of the distal radius who were treated with nonbridging external fixation for 6 weeks. The stepwise surgical technique comprised a preliminary joint-bridging construction for reduction purposes, the subsequent insertion of 3 to 4 K-wires in the distal fragment, the assembling of the k-wires to a dorsal outrigger bar that was nearly parallel to the fracture line, and lastly the removal of the joint-bridging part. Clinical and radiologic evaluation was performed on the first and seventh days, at 6 weeks and 2 years after surgery. All fractures united with a palmar tilt of # 0Ean articular step-off of # 2 mm. A loss of radial length occurred in 4 patients where only 3 k-wires were inserted in the distal fragment. No radial shortening was seen in fractures with 4 k -wires inserted in the distal fragment. The functional results at 2 years after surgery showed an average extension of 55 degrees and flexion of 64 degrees without significant differences between extra-articular and intra-articular fractures. There were no instances of extensor tendinitis or pin loosening in the distal fragment; however there were 3 cases of proximal pin tract infections. 49
Arthroscopic Assisted Reduction and Nonbridging external fixation

Indications
More than 2 mm of articular displacement or gap are typical indications for surgical treatment. Isolated radial styloid fractures and simple 3-part fractures are most suited to this technique. Four-part fractures should be tackled only after one has gained experience with simpler fracture patterns. After reduction and percutaneous pin fixation many authors use a bridging external fixator as a neutralization device or apply a volar locking plate. In many instances it has been my preference to use the Fragment Specific Fixator in a nonbridging application to allow early wrist motion.

Contraindications
Large capsular tears which carry the risk of marked fluid extravasation, active infection, neurovascular compromise and distorted anatomy are some typical contraindications. Marked metaphyseal comminution, shear fractures and a volar rim fractures require open treatment, although the arthroscope can be inserted to check the adequacy of the joint reduction.

Surgical Technique (Video: ARIF nonbridging and ARIF dry).
Intraoperative fluoroscopy is used frequently throughout the case, with the C-arm positioned horizontal to the floor. It is preferable to wait 3 -10 days to allow the initial intra-articular bleeding to stop. I have found it useful to perform much of the procedure without fluid irrigation using the dry technique of del Piñal, which eliminates the worry of fluid extravasation.50 If fluid irrigation is used, inflow is through a large bore cannula in the 4,5 or 6U portal with the outflow through the arthroscope cannula. The working portals include the volar radial (VR) and 6R portal for fracture visualization and the 3-/,4 portal for instrumentation - but all of the portals are used interchangeably. Lactated Ringer’s solution is preferred over saline and the forearm is wrapped with coban to limit extravasation.
The fracture hematoma and debris are lavaged and any early granulation tissue is debrided with a resector. Mehta and colleagues described a 5 - level algorithm for reducing the fracture fragments. This included the “London technique” for comminuted intra-articular fractures where the k-wires were advanced through the distal ulna into the subchondral distal radius and withdrawn from the radial aspect so that they did not encroach on the distal radioulnar joint ( Figure 16 A - N).51

The radial styloid is reduced through ligamentotaxis while the arm is suspended in the traction tower. A freer elevator may also be placed in the fracture site under fluoroscopic control to facilitate this step. A 1 cm incision is made over the styloid to prevent injury to the superficial radial nerve, and two 0.62 mm k-wires are inserted for manipulation of the styloid fragment. The fracture site is best assessed by viewing across the wrist with the scope in the 6R portal, in order to gauge the rotation of the styloid. The k-wires are used as joysticks to manipulate the fragment then one k-wire is driven forward to capture the reduction. The radial styloid fragment is then utilized as a landmark to which the depressed lunate fragment is reduced. An elevator or large pin is inserted percutaneously to elevate the lunate fragment, which is then held reduced with large tenaculum forceps. Forceps with large curved jaws are preferred to prevent crushing the superficial radial nerve. The tips of the forceps may be placed directly against the ulna to facilitate this step. Once the fracture fragments are anatomically reduced, horizontal subchondral k-wires are inserted, stopping short of the DRUJ. It is paramount to bone graft the metaphyseal defect through a small dorsal incision to prevent late collapse. If a dorsal die punch fragment is present, it is important that the k-wires pins are aimed dorsally to capture this fragment. In this case, use of the volar radial portal allows superior views of this dorsal fragment. Alternatively, the k-wire can be inserted retrograde through a cannula in the VR portal and brought out dorsally.

In a four-part fracture, the lunate facet is split into a volar and dorsal fragment. The volar medial fragment must usually be reduced through an open incision since wrist traction rotates this fragment and prevents reduction by closed means. The radial styloid fragment is reduced with ligamentotaxis and temporarily held with k-wires. A standard volar approach to the distal radius through the flexor carpi radialis tendon sheath is then performed. The pronator quadratus is elevated until the volar medial fragment is seen. Alternatively, a limited volar ulnar incision can be made, with radial retraction of the flexor tendons. The volar medial fragment is reduced back to the shaft and the radial styloid fragment. A 2.0 mm volar locking plate is provisionally applied to hold the reduction.

The reduction is checked through the 6R and VR portals. The dorso-medial fragment is then elevated back to the radial styloid and reduced to the volar medial fragment, which is utilized as a landmark. A small dorsal locking plate can be applied at this point, or alternatively the distal screws of the volar plate can be used to lag the volar medial and dorso-medial fragments. In this event, one or more of the distal screws should be placed in a non-locking fashion to help compress the fragments.

Wiesler et al recently reported an arthroscopic technique for the management of volar lunate facet fractures.52 A freer elevator is placed in the 3-/,4 portal and introduced into the fracture line to disengage the dorsal lunate facet fragment. A stout nerve hook is introduced obliquely through the fracture line and under the volar cortex of the volar lunate facet fragment, which is tilted, disimpacted and reduced. It is then fixed to the radial styloid with k-wires, followed by pinning of the dorsal lunate fragment. The construct is then k-wired to the radial shaft.
Ulnar Styloid Fractures and DRUJ Instability Ulnar styloid fractures may or may not be associated with disruption of the deep foveal insertion of the TFCC and secondary DRUJ instability. Many authors recommend initial fixation of the distal radius fracture and then assessment of the DRUJ for instability since fracture reduction often restores DRUJ instability. If there is more than 5 mm of anteroposterior displacement of the distal ulna during stress testing wrist arthroscopy is beneficial. Basi-styloid fractures carry the risk of TFCC detachment but in an arthroscopic study of the soft tissue lesions associated with distal radius fractures, Lindau noted that the TFCC is more commonly avulsed off its radial insertion. Any peripheral TFCC tear is repaired arthroscopically using an outside-in technique. If the articular disc has normal tension to palpation, the styloid fracture is ignored or excised if there is the worry of late carpal impingement. The deep fibers of the DRUJ can be directly assessed through a volar DRUJ portal. 53 (Video: ulnar styloid ) If there is a disruption of the deep fibers of the TFCC then an open foveal repair can be performed.54 If the TFCC remains well attached to the ulnar styloid fragment then ORIF of the styloid using k-wires and tension band fixation, cannulated screws or mitek bone anchors is performed.

Ruch et al described the use of a dorsal outrigger attached to a bridging external fixator in cases of associated DRUJ instability.55 They found that that patients in whom the ulnar styloid can be reduced and maintained in supination can be treated effectively with fixed supination using an outrigger attached to the external fixator. This method resulted in a statistically significant improvement in supination as well as a lower rate of distal radioulnar joint complications, and it required fewer secondary procedures.

Combined Fixation
Combined fixation can be performed with the fixator applied in either a bridging or nonbridging mode. In many instances the Fragment Specific fixator is applied in a radial uniplanar configuration in conjunction with a combination of a volar and/or dorsal plate (Figure 17 A - J). In these instances the fixator acts as a “3rd plate” which replaces the radial styloid plate. Alternatively this can be combined with two volar plates when there is marked peri-articular dorsal comminution (Figure 18 A - L). The fixator can be applied in a bridging fashion with dorsal outrigger support (Figure 19 A - J). It can also be applied in a nonbridging fashion after plate fixation (Figure 20 A - K).

Indications
Despite the plethora of volar plate designs, fixation of a small radial styloid fragment is often tenuous. The Fragment specific fixator can be applied in a uniplanar radial application when there is a small radial styloid fragment that cannot be adequately captured with a plate. Any sagittal split of the medial fragment that cannot be successfully reduced with percutaneous or arthroscopic methods is treated with fragment specific implants. Joint bridging fixation is indicated when there is central comminution to help unload the articular fragments.

Contraindications
Inadequate or unstable soft tissue coverage or marked swelling would preclude the use of multiple skin incisions and implants.

Surgical Technique
[Videos: i)Combined plate and bridging, ii) Nonbridging FSF with double plates]
Various authors have reported the use of joint bridging external fixation to facilitate fracture reduction and plate application.22, 49. A joint bridging external fixator is applied in a standard fashion as described above. The volar medial fragment can then be approached in a number of ways. A 3 cm volar ulnar incision is made along the ulnar border of the flexor tendons, which are retracted radially. The interposed tendons protect the median nerve, and working through the floor of the flexor tendons gain more distance from the ulnar neurovascular bundle. The pronator quadratus is identified and elevated from its ulnar insertion, and then reflected radially. Some authors use an extended carpal tunnel approach which simplifies exposure of the volar ulnar fragment. It is my preference to use the standard flexor carpi radialis (FCR) approach and then use a broad periosteal elevator to retract the flexor tendons and expose the volar ulnar corner. Alternatively the FCR approach can be combined with a volar ulnar approach through the same skin incision (Video).

My preferred technique is to first reduce the volar medial fragment to the radial shaft and to the reduced radial styloid fragment. A unicortical locking pin is placed through the distal limb of an L-shaped 2.0 mm plate to engage the volar ulnar fragment. This allows one to control and reduce the fragment. The traction is then released and the proximal aspect of the plate is fixed to the radial shaft. The wrist is then again distracted and a dorsal approach through the 3rd extensor compartment is performed. The EPL tendon is removed from it’s compartment and retracted. The 4th extensor compartment is elevated without disrupting the extensor tendons to gain access to the dorso-medial fragment. The dorsal cortex is typically quite comminuted and can often be opened like a book to expose the articular surface. Any tilted or depressed articular fragments are elevated and supported by subchondral structural bone graft. The dorsal cortex is then folded back down and held in place with a dorsal 2.0 mm locking plate. It is not always possible to place more than 1 distal screw due to the small size of the fragments. Additional bicortical locking screws can however now be applied through the more proximal holes to “sandwich” the volar and dorsal medial fragments Once again, the traction is released prior to attaching the plate to the proximal shaft. When using a standard joint bridging fixator, the radial column can be held with k-wires or a cannulated screw. Unless there is marked articular comminution, I insert the two radial styloid pins and apply the Fragment Specific Fixator in a nonbridging manner to and allow early protected motion. (Video)

Complications
The complications are similar to those described above. There is a greater risk of hardware intereference with tendon gliding and cutaneous nerve branches as the number of plates increase. The volar and dorsal exposure may also devascularize small fragments which can lead to delayed healing or late collapse which is the rationale for the use of locking plates rather than conventional mini-plates. In elderly populations with osteopenic bone, some fracture site settling cannot be avoided even following bone grafting, external fixation and locking plates (Figure 21 A - J).

Summary
Although currently not in vogue, ligamentotaxis still has its uses, especially in situations that would preclude internal plate fixation. Novel fixator designs are opening new horizons but multi-center clinical trials are necessary in order to determine whether the superior results obtained with nonbridging fixation of extra-articular fractures can be duplicated with intra-articular fractures. The combination of external fixation with limited internal fixation is a useful adjunctive technique with multi-fragmented fractures. Gaining an understanding of the principles and limitations of external fixation allows one to be flexible and adapt the fixation to the specific fracture pattern in order to maximize the chances for an acceptable outcome.

Legends:
Figure 1. Proximity of the superficial radial nerve (SRN) branches (SR1,2,3) to potential pin placement sites.
Figure 2. Limitations of ligamentotaxis
A. Marked radial shortening.
B. Initial over distraction restores radial length.
C. Note the persistent dorsal tilt of the articular surface even with maximum distraction.
Figure 3. Stress Relaxation
A. Note the over distraction of the radiocarpal joint and the restoration of radial length.
B. 2 weeks later there is a loss of the radial length and the joint space is no longer over distracted.
Figure 4. Unstable distal radioulnar joint
A. Unstable distal radius fracture with disruption of the distal radioulnar joint.
B. The medial (sigmoid notch) fragment follows the ulnar head due to the intact radioulnar ligaments and cannot be stabilized with k-wires and bridging external fixation.
Figure 5.
A. Open distal radius fracture.
B. X-ray appearance.
C. Temporary stabilization with a bridging external fixator.
Figure 6. Dynamic MP flexion splints are applied while the fixator is still in place.
Figure 7. The fixator frame is improperly applied with the wrist in marked flexion.
Figure 8. The fracture reduction is captured with percutaneous k-wires then neutralized with an external fixator with the wrist in slight extension.
Figure 9.
A. 4-part intra-articular fracture
B. Increased tear drop angle indicative of a sagittal split of the medial fragment
C. AP view reveals a restoration of the radial height and apparent congruency of the joint surface.
D. Lateral view reveals the sagittal split and increased rotation of the palmar medial fragment.
E. Close up with the volar medial and dorsal medial fragments outlined.
Figure 10. Limited internal fixation.
A. AP x-ray of a displaced 4-part fracture.
B. Lateral view demonstrates a sagittal split of the medial fragment.
C. Internal fixation of medial fragment through a limited volar ulnar approach.
D. Fluoroscopy demonstrates the reduction of the medial fragment.
E. Radial styloid is reduced with ligamentotaxis and held with an oblique percutaneous k-wire.
F. Percutaneous screw fixation replaces the oblique radial styloid k-wire.
G. Subchondral k-wire inserted to support the joint surface.
H. Percutaneous bone grafting of metaphysis.
I. Second k-wire replaced by a percutaneous screw which stops short of the DRUJ.
J. Lateral view demonstrating restoration of normal tilt and reduction of the sagittal split.
Figure 11. Primary nonbridging external fixation
A. 56 y.o. female with acute displaced extra-articular fracture.
B. Note the 35° of dorsal tilt.
C. Application of nonbridging external fixator.
D. Note correction of volar tilt.
E. Clinical appearance
F. Note distal fragment fixation with 3 percutaneous pins
G. Appearance at 6 weeks with restored alignment.
H. 5° of volar tilt.
Figure 12. Nonbridging external fixation – redisplaced fracture
A. 55 y.o. female with extra-articular radius fracture.
B. Note the marked dorsal comminution.
C. Initial anatomic closed reduction.
D. Restoration of volar tilt.
E. Redisplacement at 8 days with loss of radial height.
F. Loss of volar tilt.
G. Appearance after percutaneous bone grafting.
H. Lateral view after bone grafting.
I. Insertion of dorsal fixator pins.
J. Lateral view with nonbridging external fixator
K. Postoperative x-ray at 1 week with additional radial styloid pin.
L. Appearance at 8 weeks – there is some radial translation but restored radial height and radial tilt
M. 10° of volar tilt and healed volar defect.
Figure 13.
A. Biomechanical study of a 3-part intra-articular fracture using the Fragment Specific Fixator.
B. Cut-away view of the distal radius demonstrating stacking of the fixator pins in multiple planes similar to a fixed angle plate.
Figure 14.
A. Displaced 3-part distal radius fracture.
B. Dorsal tilt of the joint surface
C. Anteroposterior CT scan highlighting the size of the medial fragment.
D. Lateral CT demonstrating the sagittal split of the medial fragment.
E. Coronal CT showing disruption of the sigmoid notch.
F. Reduction of coronal split with percutaneous bone forceps.
G. Reduction of dorsal tilt and application of nonbridging fixator.
H. AP view demonstrating closure of the coronal gap.
I. Insertion of an oblique radial styloid pin
J. Clinical appearance of fixator after reduction.
K. Palmar view of the radial styloid pin which does not interfere with thumb motion.
L. Passive wrist flexion.
M. Passive wrist extension.
Figure 15.
A. X-ray appearance following nonbridging external fixation of 3-part fracture
B. Anterposterior CT shows the anatomic reconstruction of the joint space.
C. Coronal CT demonstrating fixation of the dorsomedial fragment with the fixator pin.
D. Correction of dorsal tilt seen on lateral CT view.
E. Appearance at 4 weeks after removal of radial styloid pin.
F. AP view
G. Lateral view
H. Wrist flexion in fixator at 4 weeks.
I. AP view at 4 months.
J. Lateral view at 4 months.
K. Wrist flexion of 60°.
L. Wrist extension of 60°.
M. Full pronation.
N. Full supination.
Figure 16. Arthroscopic guided pinning and nonbridging external fixation
A. Comminuted intra-articular distal radius fracture.
B. Lateral View
C. Anteroposterior CT view reveals the extent of the intra-articular fragmentation.
D. Lateral CT highlights the small dorsal rim fragments.
E. Coronal CT view shows the sigmoid notch disruption.
F. Arthroscopic view of joint surface showing the degree of comminution.
G. A percutaneous is inserted through the ulna to capture and control the medial fragment.
H. Percutaneous reduction of dorsal tilt.
I. Fluoroscopic appearance.
J. Arthroscopic view following reduction and pinning.
K. Fluoroscopic view after arthroscopic reduction.
L. Application of nonbridging external fixator
M. Result at 6 months with restored radial height and tilt.
N. Congruent joint space with neutral lateral tilt.
Figure 17. 23 y.o. male with displaced intra-articular fracture
A. AP view demonstrates marked radial shortening.
B. The lateral view shows a small distal fragment and marked dorsal tilt.
C. Anteroposterior CT images reveal the small medial fragment
D. Lateral CT highlights the thin volar medial articular fragment.
E. Coronal CT reveals a small, comminuted dorso-medial wall fragment with sigmoid notch disruption.
F. Intra-operative x-rays demonstrating anatomic restoration of the joint surface but nonrigid pin fixation of the dorsal wall fragments which necessitates temporary bridging external fixation to unload the joint space.
G. Lateral view shows sandwiching of the fracture fragments with volar and dorsal plates with restored volar tilt.
H. Postoperative result.
I. PA view at 4 weeks after fixator removal.
J. Lateral view at 4 weeks after fixator removal.
Figure 18. Volar shear fracture with dorsal comminution
A. Intra-articular fracture with marked radial shortening.
B. Lateral x-ray shows a volar shear pattern with dorsal comminution.
C. Anteroposterior CT reveals an undisplaced sagittal split of the volar articular fragment.
D. Lateral CT highlights the marked periarticular dorsal comminution that precludes plate fixation.
E. Coronal CT demonstrating the sigmoid notch disruption.
F. Initial joint bridging external fixation clarifies the fracture anatomy.
G. Ligamentotaxis alone however does not reduce the articular incongruity.
H. Volar locking plate applied to the radial column.
I. 2nd volar plate applied to the intermediate column.
J. Articular congruity is restored.
K. AP view at 8 weeks.
L. Lateral view at 8 weeks.
Figure 19. Joint bridging external fixation with dorsal outrigger
A. Comminuted intra-articular fracture.
B. Marked dorsal tilt.
C. Fragmentation of medial fragments
D. Sagittal split with peri-articular dorsal comminution.
E. Volar approach highlights the cortical comminution.
F. Lunate is visible through the sagittal split.
G. Volar plate application after bone grafting.
H. Result at 6 months with congruous sigmoid notch and restored radial height.
J. Reasonable joint congruity but some residual central depression.
Figure 20. Volar plating with nonbridging external fixation
A. Intra-articular fracture with metaphyseal extension.
B. Depression and dorsal tilt of articular fragments.
C. Fixation of palmar medial fragment - note distal screw does not engage the dorsal fragment as yet.
D. Restoration of sigmoid notch.
E. Distraction with temporary joint bridging external fixation facilitates reduction of dorsal fragments.
F. Fixator is then applied in a nonbridging configuration.
G. AP view showing restoration of radial height and tilt.
H. Lateral view shows reconstitution of joint surface “sandwiched” between volar and dorsal plates.
I. Clinical appearance at 4 weeks.
J. AP view at 8 weeks.
K. Maintenance of congruent joint after fixator removal.
Figure 21. 80 y.o. female with fragile skin.
A. AP view of an unstable periarticular fracture with marked radial shortening.
B. Lateral view highlighting the dorsal comminution and dorsal tilt.
C. Volar approach to the fracture site.
D. Pronation of the proximal radial shaft exposes the fracture.
E. Allograft is packed into the metaphyseal defect.
F. Neutralization plate is then applied.
G. External fixation restores a - 1 mm ulnar variance.
H. Note the fragile skin envelope which precludes a large dorsal dissection.
J. Result at 3 months. Note the late settling at the fracture site despite external fixation, plating and bone grafting, resulting in a 3 mm ulna positive variance but preserved radial tilt.
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