Robert J. Medoff
DEFINITION
Fragment-specific fixation is a treatment approach in which each major fracture component is identified and fixed independently using low-profile implants with a certain degree of “spring-like” elasticity.
Each fracture component has a unique implant specifically designed for that particular fracture element (FIG 1).
Surgical planning is extremely important to determine whether a single approach or a combination of surgical approaches is needed to visualize and fix each of the main fracture components present in a particular injury.
At the start of surgery, a complete set of implants should be available to address fractures of the radial column, ulnar corner, volar rim, dorsal wall, and free impacted articular fragments. In addition, identification and treatment of distal radioulnar joint (DRUJ) disruptions or unstable fractures of the ulnar column may be required.
As a rule, this technique avoids creating large holes in small distal fragments, with fixation based and often triangulated to the stable ipsilateral cortex of the proximal fragment.
The goal of fragment-specific fixation is to create a multiplanar, load-sharing construct that anatomically restores the articular surface and has enough stability to allow immediate motion after surgery.
ANATOMY
The radial column fragment is formed from the pillar of bone along the radial border (FIG 2). This fracture component is important to maintain radial length to support the carpus in its normal spatial position. The brachioradialis inserts on the base of the radial column and may result in shortening of the radial column fragment, leading to impaction of the carpus into remaining fragments. Metaphyseal comminution may also contribute to radial column instability.
The volar rim of the lunate facet is a primary load-bearing structure of the articular surface. Instability of the volar rim occurs in two patterns:
In the volar instability pattern, shortening and volar translation of the volar rim result in secondary volar subluxation of the carpus.
FIG 1 • Fragment-specific implants.
FIG 2 • Articular fracture components.
In the axial instability pattern of the volar rim, axial impaction of the carpus drives the volar rim into dorsiflexion, resulting in secondary axial and dorsal subluxation of the carpus.
The ulnar corner fragment involves the dorsal half of the sigmoid notch. Typically a result of impaction of the lunate into the articular surface, this fragment migrates dorsally and shortens proximally. Residual displacement of the ulnar corner can result in instability of the DRUJ as well as restriction of forearm rotation.
Dorsal wall fragmentation typically occurs with either dorsal bending injuries or axial loading injuries and may contribute to fracture instability.
Free articular fragments may be impacted within the metaphyseal cavity and result in incongruity of the articular surface.
PATHOGENESIS
Dorsal bending injuries result in extra-articular fractures with dorsal displacement (FIG 3A). Comminution of the metaphyseal cavity or dorsal wall usually suggests a dorsally unstable fracture pattern.
Volar bending injuries result in extra-articular fractures with volar displacement (FIG 3B). Fractures with significant volar displacement are nearly always unstable and require some type of intervention to obtain and hold a reduction until union.
Dorsal shearing injuries present as fractures of the dorsal rim and are often associated with dorsal instability of the carpus (FIG 3C).
Volar shearing injuries present as displaced fractures of the volar rim and result in volar instability of the carpus (FIG 3D). Often, this pattern is comminuted and highly unstable and not suited to closed methods of treatment.
Simple three-part fractures are usually the result of lowenergy injuries that combine an axial loading and dorsal bending mechanism (FIG 3E). This pattern is characterized by the presence of an ulnar corner fragment that involves the dorsal portion of the sigmoid notch, a main articular fragment, and a proximal shaft fragment.
Unstable fractures with complex involvement of the articular surface to simplify complex articular fractures. In addition to articular comminution, this pattern may often generate a significant defect in the metaphyseal cavity or complete disruption of the DRUJ (FIG 3F).
FIG 3 • Pathogenesis of dorsal radius fractures. A. Dorsal bending. B. Volar bending. C. Dorsal shear. D. Volar shear. E. Three-part articular. F. Comminuted articular. G. Carpal avulsion. H. High energy.
The avulsion and carpal instability pattern is primarily a ligamentous injury of the carpus that has associated osseous avulsions of the distal radius (FIG 3G).
Extremely high-energy injuries present as complex fractures involving comminution of the articular surface as well as extension into the radial or ulnar shaft (FIG 3H).
IMAGING AND OTHER DIAGNOSTIC STUDIES
Posteroanterior (PA), standard lateral (FIG 4A,B), and 10degree lateral views are routine views for radiographic evaluation of the distal radius. The 10-degree lateral view (FIG 4C,D) clearly visualizes the ulnar two thirds of the articular surface from the base of the scaphoid facet through the entire lunate facet. Oblique views may also be helpful for evaluating the injury.
The radiographic features of distal radius fractures include the following:
Carpal facet horizon (FIG 5A,B). This is the radiodense horizontal landmark that is used to identify the volar and dorsal rim on the PA view. If the articular surface is in palmar tilt, the x-ray beam is parallel to the subchondral bone of the volar half of the lunate facet and the carpal facet horizon identifies the volar rim. However, if the articular surface is in dorsal tilt, the x-ray beam is parallel to the subchondral bone of the dorsal half of the lunate facet and the carpal facet horizon identifies the dorsal rim (not shown). The carpal facet horizon is the portion of the articular surface that is visualized on the 10-degree lateral x-ray projection.
Teardrop angle (normal 70 ± 5 degrees; FIG 5C,D). The teardrop angle is used to identify dorsiflexion of the volar rim of the lunate facet. Depression of the teardrop angle to a value less than 45 degrees indicates that the volar rim of the lunate facet has rotated dorsally and impacted into the metaphyseal cavity (axial instability pattern of the volar rim). This may be associated with axial and dorsal subluxation of the carpus. Restoration of the teardrop angle is necessary to correct this type of malreduction.
Articular concentricity (FIG 5E,F). The subchondral outline of the articular surface of the distal radius is normally congruent and concentric with the subchondral outline of the base of the lunate; a uniform joint interval should be present between the radius and lunate along the entire articular surface. When these articular surfaces are not concentric, discontinuity and disruption of the lunate facet has occurred.
FIG 4 • A. Positioning for standard lateral radiography. B. Standard lateral radiograph. C. Positioning for 10-degree lateral radiography. D. Ten-degree lateral radiograph. Note the improved visualization of the articular surface of the base of the scaphoid facet and the entire lunate facet.
FIG 5 • A. Carpal facet horizon (arrows). Used to differentiate between the volar and dorsal rim on the PA projection. B. Origin of carpal facet horizon. The carpal facet horizon is formed by that part of the articular surface that is parallel to the x-ray beam and depends on whether the articular surface is in volar or dorsal tilt. C. Normal teardrop angle. D. Depressed teardrop angle, in this case caused by axial instability of the volar rim. E. Normal articular concentricity. F. Abnormal articular concentricity, indicating disruption across the volar and dorsal surfaces of the lunate facet. G. AP interval is the point-to-point distance between the corners of the dorsal and volar rim. H. Distal radioulnar joint interval. I. Normal lateral carpal alignment. J. Dorsal subluxation of the carpus.
AP distance (normal: females 18 ± 1 mm, males 20 ± 1 mm; FIG 5G). The AP distance is the point-to-point distance from the dorsal corner of the lunate facet to the palmar corner of the lunate facet. It is best evaluated on the 10-degree lateral view. Elevation of the AP distance indicates disruption of the volar and dorsal portion of the lunate facet.
DRUJ interval (FIG 5H). The DRUJ interval measures the apposition between the head of the ulna and the sigmoid notch. Significant widening of the DRUJ interval implies disruption of the DRUJ capsule and triangular fibrocartilage complex (TFCC).
Lateral carpal alignment (FIG 5I,J). The center of rotation of the capitate normally lines up with a line extended from the volar surface of the radial shaft with the wrist in neutral position. Dorsal rotation of the volar rim results in dorsal subluxation of the carpus from this normal position, placing the flexor tendons at a mechanical disadvantage, which may affect grip strength.
In addition to the injury films, it is important to reassess postreduction views to determine the personality and specific components of the fracture.
CT scans allow higher resolution and definition of fracture characteristics, particularly for highly comminuted fractures. Preferably, an attempt at closed reduction is done before a CT scan is obtained to limit distortion of the image. CT scans are particularly helpful for visualizing intra-articular fragments as well as DRUJ disruption.
Clinical and radiographic evaluations of the carpus, interosseous membrane, and elbow are used to identify the presence of other associated injuries that may affect the decision for a particular treatment.
SURGICAL MANAGEMENT
Operative Indications
General parameters:
Shortening of more than 5 mm
Radial inclination of less than 15 degrees
Dorsal angulation of more than 10 degrees
Articular stepoff of more than 1 to 2 mm
Depression of teardrop angle of less than 45 degrees
Volar instability
DRUJ instability
Displaced articular fractures
Young, active patients are generally less tolerant of residual deformity and malposition.
Preoperative Planning
Extra-articular fractures: multiple options:
Volar plating through a volar approach
Dorsal plating through a dorsal approach
Fragment-specific fixation
Radial pin plate (TriMed, Inc., Valencia, CA) and volar buttress pin (TriMed, Inc.) fixation through a limited incision volar or standard volar approach
Radial pin plate and either an ulnar pin plate dorsally or a dorsal buttress pin through a dorsal or combined approach
Intra-articular fractures: surgical approach is based on the fragmentation pattern
Unstable volar rim fragments require a standard volar or ulnar-volar approach for adequate visualization.
Fixation of the radial column can be done through either a limited-incision volar-radial approach, a volar approach with a radial extension combined with pronation of the forearm, or a dorsal approach with radial extension combined with supination of the forearm.
Fixation of dorsal, ulnar corner, and free intra-articular fragments can be done through a dorsal approach.
Positioning
The patient is supine.
The affected arm is on an armboard out to the side.
C-arm
If the armboard is radiolucent, the C-arm can be brought in from the end of the armboard and images taken directly with the wrist on the armboard.
If the armboard is not radiolucent, the C-arm is brought in along the side of the table from the foot, and the arm is brought off the armboard for each image.
Operative Sequence
Radial column length is restored first with traction; a transstyloid pin is inserted to hold the reduction if needed.
The volar rim is reduced and fixed.
The dorsal ulnar corner is reduced and fixed.
Free intra-articular fragments and the dorsal wall if needed are reduced and stabilized.
Bone graft is applied if the metaphyseal defect is large.
Fixation is completed with a radial column plate.
Approach
The repair is undertaken by means of one of the following approaches:
Limited-incision volar approach
Dorsal approach
Extensile volar approach
Volar-ulnar approach
TECHNIQUES
LIMITED-INCISION VOLAR APPROACH
Make a longitudinal incision along the radial side of the radial artery.
Proximally, insert the tip of a tenotomy scissors over the surface of the first dorsal compartment sheath and sweep distally to elevate a radial skin flap.
Pronate the forearm and sharply expose the bone over the radial styloid in the interval between the first and second dorsal compartments (TECH FIG 1A).
Leaving the distal 1 cm of sheath intact, open the first dorsal compartment proximally and mobilize the tendons. Reflect the insertion of brachioradialis to expose the radial column (TECH FIG 1B).
If needed, the dissection can be continued through the floor of the incision to expose the volar surface. Detach the insertion of the pronator quadratus radially and distally and reflect it to the ulnar side. Alternatively, create an ulnar skin flap superficial to the artery and continue the exposure through a standard volar approach.
This approach cannot be used to access the ulnar side of the volar rim.
TECH FIG 1 • Limited-incision volar approach. A. Sweeping tenotomy scissors to elevate radial skin flap off first dorsal compartment. B. Deep exposure of the radial column.
DORSAL APPROACH
Make a longitudinal skin incision dorsally along the ulnar side of the tubercle of Lister (TECH FIG 2A).
Identify the extensor digitorum communis (EDC) tendons visible proximally through the translucent extensor sheath. Incise the dorsal retinacular sheath.
Develop the interval between the third and fourth compartment tendons for access to dorsal wall and free, impacted articular fragments. Resect a segment of the terminal branch of the posterior interosseous nerve (TECH FIG 2B).
Transpose the extensor pollicis longus (EPL) from the tubercle of Lister if required for additional exposure.
Develop the interval between the fourth and fifth extensor compartments to gain access to the ulnar corner fragment.
A dorsal capsulotomy can be done to visualize the articular surface and carpus if necessary.
To gain access to the radial column through a dorsal exposure, extend the incision as needed and elevate a radial subcutaneous flap and supinate the wrist.
To gain access to the distal ulna, extend the incision as needed and elevate an ulnar subcutaneous flap.
TECH FIG 2 • Dorsal approach. A. Initial incision. B. Deep exposure.
EXTENSILE VOLAR APPROACH
Start the skin incision at the distal pole of the scaphoid and angle it toward the radial border of the flexor wrist crease, then extend it proximally along the flexor carpi radialis (FCR) tendon (TECH FIG 3A).
Open the FCR tendon sheath both proximally and distally and continue in the plane between the FCR tendon and the radial artery (TECH FIG 3B).
Use blunt dissection with a finger or sponge to separate the interval between the contents of the carpal tunnel and the surface of the pronator quadratus. Retract the FCR, median nerve, and flexor tendons to the ulnar side.
Divide the radial and distal attachment of the pronator quadratus and reflect it to the ulnar side. Limit the distal dissection to no more than 1 or 2 mm beyond the distal radial ridge to avoid detachment of the volar wrist capsular ligaments (TECH FIG 3C).
Reflect the brachioradialis from its insertion on the distal fragment if needed. Bone graft can be applied through the radial fracture defect.
If access to the radial column is needed, elevate a radial subcutaneous flap superficial to the radial artery and first dorsal compartment tendon sheath. Pronate the wrist and retract the radial skin flap to expose the radial column.
TECH FIG 3 • Extensile volar approach. A. Initial incision. B. Line of incision in pronator quadratus. C. Deep exposure.
VOLAR-ULNAR APPROACH
Make a longitudinal skin incision along the ulnar border of the flexor carpi ulnaris (FCU) tendon (TECH FIG 4A).
Reflect the FCU tendon and the ulnar artery and nerve to the ulnar side (TECH FIG 4B).
With blunt finger or sponge dissection, develop the plane on the superficial surface of the pronator quadratus.
Retract the contents of the carpal tunnel to the radial side (TECH FIG 4C).
Reflect the pronator quadratus from its ulnar and distal attachment. Do not dissect more than 1 to 2 mm beyond the distal radial ridge to avoid detaching the volar wrist capsule.
TECH FIG 4 • Volar-ulnar approach. A. Incision. B. Initial exposure. C. Completed exposure.
RADIAL COLUMN FIXATION WITH RADIAL PIN PLATE
Expose the radial column with any of the approaches previously described. Sharply expose the interval between the first and second dorsal compartments over the tip of the radial styloid. Release the tendon sheath of the first dorsal compartment proximally, leaving the last 1 cm of tendon sheath intact.
Retract the tendons of the first dorsal compartment dorsally or volarly as needed. Release the terminal insertion of the brachioradialis to complete exposure of the radial column.
After the initial fracture exposure, restore radial length with traction and ulnar deviation of the wrist. If needed, structural bone graft can be inserted through the radial fracture defect.
Insert a 0.045-inch transstyloid Kirschner wire angled to engage the far cortex of the proximal fragment (TECH FIG 5A). When the advancing tip of the Kirschner wire hits the far cortex, place a drill sleeve over the Kirschner wire to use as a drill stop to limit penetration of the far cortex to 1 to 2 mm.
Once the radial column is temporarily fixed with a transstyloid Kirschner wire, reduce and stabilize other volar, dorsal, and articular fracture elements before completing fixation of the radial column.
Select a distal pin hole and slide a radial pin plate over the transstyloid Kirschner wire. Proximally, guide the plate under the tendons of the first dorsal compartment and secure it initially with a single 2.3-mm bone screw.
Insert a second transstyloid Kirschner wire through a non-adjacent distal pin hole. Use the previous techniqueto limit penetration of the Kirschner wire through the far cortex to 1 to 2 mm.
Mark a reference point where the Kirschner wire crosses the surface of the plate. Withdraw the Kirschner wire 1 cm and cut it 1 cm or more above the reference mark (TECH FIG 5B).
Position the reference mark between the lower two posts of a wire bender and create a hook (TECH FIG 5C). The bend should start at the reference mark to make a Kirschner wire of proper length when completed.
Complete the bend with a pin clamp, overbending slightly to allow the hook to snap into an adjacent pin hole or over the edge of the plate. With a free 0.045-inch Kirschner wire, predrill a hole to accept the end of the hook (TECH FIG 5D).
Impact the Kirschner wire with a pin impactor and fully seat the hook (TECH FIG 5E). Repeat the procedure with the second Kirschner wire.
Complete proximal fixation with 2.3-mm cortical bone screws (TECH FIG 5F,G).
TECH FIG 5 • Radial column fixation. A. Insertion of transstyloid Kirschner wire. B,C. Creation of pin hook. D,E. Completion and impaction of pin hook. F,G. Completed radial column fixation.
ULNAR CORNER AND DORSAL WALL FIXATION
Ulnar Pin Plate
Through a dorsal approach, expose and reduce the dorsal ulnar corner fragment, dorsal wall fragment, or both.
Insert a 0.045-inch Kirschner wire through the fragment (TECH FIG 6A), angled proximally and slightly radially to purchase the far cortex of the proximal fragment.
Insert structural bone graft into the metaphyseal defect if present to support the subarticular surface.
If the plate is aligned over the ulnar half of the shaft, add a 15-degree torsional bend to the plate (twist the proximal end of the plate into slight supination). Often, a little extra extension can be contoured at the distal end of the plate (TECH FIG 6B).
Slide the plate over the Kirschner wire and fix it proximally with a 2.3-mm bone screw (TECH FIG 6C).
Insert a second Kirschner wire if the fragment is large enough. Create and impact hooks as described for the radial pin plate (TECH FIG 6D–E).
If the Kirschner wire tips protrude beyond the volar cortex, they can be cut flush to the bone surface through a volar incision.
Dorsal Buttress Pin
Through a dorsal approach, expose and reduce the dorsal ulnar corner fragment, dorsal wall fragment, or both.
TECH FIG 6 • Ulnar corner fixation with an ulnar pin plate. A. Insertion of the interfragmentary Kirschner wire. B. Contouring the plate. C. Application of the plate and insertion of the initial fixation screw. D. Fixation completed. E,F. Radial and ulnar pin plate fixation of a three-part articular pattern (radial column and ulnar corner fragment).
Insert structural bone graft into the metaphyseal defect if present to support the subarticular surface.
Insert two 0.045-inch Kirschner wires through the dorsal cortex and behind the subchondral bone; check the position with the C-arm (TECH FIG 7A). The Kirschner wires should be separated by about 1 cm and should be transverse to the longitudinal axis of the shaft. Initially placing a dorsal buttress pin upside-down on the bone is helpful to use as a template to visualize the proper position and insertion angle of the Kirschner wires (TECH FIG 7B).
Ensure that the leading tips of the legs of the dorsal buttress pin are straight and cut to the required length (TECH FIG 7C). Leave the ulnar leg 2 to 3 mm longer than the radial leg so one leg can be engaged at a time.
Place the ulnar leg of the buttress pin adjacent to the insertion site of the ulnar Kirschner wire, and then withdraw the Kirschner wire and immediately engage the leg in the hole. Repeat with the radial Kirschner wire to engage the radial leg of the buttress pin. Impact and seat the buttress pin (TECH FIG 7D).
Fine-tune the reduction and complete the fixation proximally with one or two 2.3-mm cortical bone screws and washers (TECH FIG 7E,F). If needed, a blocking screw can be placed just proximal to the end of the buttress pin to prevent shortening of the fragment.
TECH FIG 7 • Dorsal buttress pin fixation. A. The position of the Kirschner wires is checked with a C-arm before inserting the implant. B. Placing an implant upside-down on bone to template the trajectory of the Kirschner wires. C. Inserting the dorsal buttress pin. D. Buttress pin fixation completed. E,F. Fixation of a three-part articular fracture with radial column and ulnar corner fragment with radial column plate and dorsal buttress pin.
VOLAR RIM FRAGMENT
Small-Fragment Plate Fixation
Small-fragment volar plate fixation may be indicated for treatment of a volar instability pattern of the volar rim. The fragment must be of adequate size to allow buttressing on the volar surface by the plate (TECH FIG 8A,B).
If volar rim fragmentation is associated with an axial instability pattern, the fragment must be of adequate size and strength to allow distal locked screw purchase to obtain angular correction of the dorsiflexion deformity.
An appropriate volar approach is used to expose the volar rim fragment. If a shortened radial column fragment is present, first restore radial length and provisionally hold it with a transstyloid Kirschner wire to unload the lunate facet.
TECH FIG 8 • Volar rim fixation with small-fragment plate. A,B. Shear fracture of volar rim with volar instability pattern. C,D. Fixation with small-fragment plate.
Reduce the volar rim fragment; this should restore normal carpal alignment.
Apply a small-fragment volar plate and fix it proximally with cortical bone screws. If needed, secure the distal fragment with standard or locking bone screws (TECH FIG 8C,D).
Volar Buttress Pin Fixation
Volar buttress pin fixation is indicated for unstable volar rim fragments and can be a particularly effective technique when faced with small distal fragments or axial instability patterns of the volar rim (depressed teardrop angle; TECH FIG 9A,B).
Use an appropriate volar approach to expose the volar rim fragment. If necessary, restore radial length and provisionally hold it with a transstyloid Kirschner wire to unload the lunate facet (TECH FIG 9C).
Continue exposure for up to 1 to 2 mm beyond the distal radial ridge. Reduce the volar rim fragment as much as possible and note the orientation of the teardrop on the 10-degree lateral view.
Insert two 0.045-inch Kirschner wires transverse to one another starting at an entry site 1 to 2 mm beyond the distal radial ridge. They should be placed within the center of the teardrop on the lateral view. Confirm the position of the Kirschner wires with C-arm.
If necessary, the volar buttress pin may be contoured with a wire bender to match the flare of the volar surface of the distal radius. Adjust the trajectory of the legs of the implant to make a 70-degree angle with the base of the wire form. Cut the legs to appropriate length, leaving the ulnar leg 2 to 3 mm longer than the radial leg (TECH FIG 9D,E).
Noting the entry site of the Kirschner wire, carefully remove the ulnar Kirschner wire and engage the ulnar leg of the volar buttress pin. Repeat the procedure with the radial leg. Impact and seat the implant into the volar rim fragment (TECH FIG 9F).
Fine-tune the reduction and fix it proximally with a minimum of two screws and washers (TECH FIG 9G,H).
TECH FIG 9 • Volar rim fixation with a volar buttress pin. A,B. Articular fracture with axial instability pattern of volar rim. C. Insertion of Kirschner wires. D. Cutting and inserting legs. E. Reduction of teardrop. F. Completed fixation. G,H. Volar buttress pin fixation to control rotational alignment of volar rim fragment.
FREE ARTICULAR FRAGMENT SUPPORT WITH A BUTTRESS PIN
Free articular fragments impacted into the metaphyseal cavity require both a buttress to support the subchondral surface and circumferential peripheral cortical stability to prevent displacement (TECH FIG 10A).
In some cases, impacted free articular fragments may be adequately supported by a properly applied locking plate that provides subchondral support.
An alternative method is to use structural bone graft to support the free articular fragment in combination with fragment-specific fixation of the surrounding cortical shell, resulting in containment of the graft within the metaphysis.
The dorsal buttress pin can also be used for direct subchondral support of impacted articular fragments. The legs of the implant are cut to length and inserted through the dorsal defect, slid distally directly behind the articular fragment, and then fixed proximally with a screw and washer (TECH FIG 10B). The articular fragment is sandwiched between the base of the lunate and the legs of the implant (TECH FIG 10C).
TECH FIG 10 • A. Depressed articular fragment. B. Support of free articular fragment with a buttress pin. C. Dorsal buttress pin to support fragment from endosteal surface.
POSTOPERATIVE CARE
At the end of the surgical procedure, confirm the stability of fixation as well as the stability of the DRUJ.
If stable, apply a removable wrist brace and instruct the patient to initiate gentle range-of-motion exercises of the fingers, wrist, and forearm twice or more daily as tolerated. For noncompliant patients or injuries with tenuous fixation, use a cast for 2 to 3 weeks postoperatively.
Avoid resistive loading across the wrist until signs of radiographic healing are present; typically this occurs by 4 weeks postoperatively. Specifically instruct older patients not to push up out of a chair or lift heavy objects after surgery.
If there is persistent stiffness after 4 weeks, initiate physical and occupational therapy.
OUTCOMES
Konrath and Bahler4 reported 27 patients with at least 2 years of follow-up:
One fracture lost reduction.
Patient satisfaction was high (average DASH scores 17 and PRWE scores 19 at follow-up).
In only three cases was hardware removed; no tendon ruptures occurred.
Schnall et al7 reported on two groups of patients: group I had sustained high-energy trauma and group II had lowerenergy injuries.
Group I patients averaged return to work in 6 weeks, with all fractures uniting without loss of position or deformity.
Two patients in group I required removal of painful hardware.
Group II patients averaged 2 degrees of loss of volar tilt, a 0.3-mm change in ulnar variance, and no loss of joint congruity at follow-up.
Grip strength in group II patients was 67% of the contralateral side.
Benson et al2 reported on 85 intra-articular fractures in 81 patients with a mean follow-up of 32 months.
There were 64 excellent and 24 good results, with an average DASH score of 9 at final follow-up.
Flexion and extension motion was 85% and 91% of the opposite side at final follow-up.
Grip strength was 92% of the opposite side at final follow-up.
Sixty-two percent of patients had a 100-degree arc of flexion–extension and normal forearm rotation by 6 weeks postoperatively.
Postoperative radiographic alignment was maintained at follow-up.
There were no cases of symptomatic arthritis.
COMPLICATIONS
Stiffness: common early, uncommon at follow-up
Recovery can be accelerated by anatomic fixation that is stable enough to start motion immediately after surgery. The relative degree of trauma to the bone and soft tissues, combined with underlying physiologic factors, is also a critical factor that can lead to slow recovery of motion or residual stiffness.
Malunion or nonunion: rare
Loss of reduction may occur, particularly if a major fracture component is missed and left untreated. In addition, osteoporosis, failure to graft the metaphyseal defect, and associated DRUJ injuries may contribute to loss of reduction or malunion.
Pin plates are able to resist translational displacements but are less effective for preventing loss of length; they require osseous contact between the proximal and distal fragments or additional support by a secondary implant that will buttress the subchondral surface.
Nonunions are extremely rare.
Tendinitis or tendon rupture: uncommon
If pins are noted postoperatively to back out, they should be removed. Leaving the distal 1 cm of tendon sheath of the first dorsal compartment intact helps avoid tendon contact with hardware.
Using low-profile implants dorsally, covering the distal ends with a strip of retinacular sheath, or both is also helpful.
The surgeon should avoid leaving screws or pins protruding from the dorsal or volar surfaces of the bone.
Painful hardware: rare
Painful hardware can be related to migration of a pin or settling of the fracture proximally. Overbending pin hooks and using bone graft or buttressing implants can help avoid this problem.
Remove hardware when painful.
Late arthritis is uncommon and probably related to the quality of the articular restoration.
Infections, bleeding, carpal tunnel syndrome, and other nerve injuries are uncommon and often related to the primary injury.
Complex regional pain syndrome is rare and may be related to initiation of early motion after surgery.
REFERENCES
1. Barrie K, Wolfe S. Internal fixation for intraarticular distal radius fractures. Tech Hand Up Extrem Surg 2002;6:10–20.
2. Benson LS, Minihane KP, Stern LA, et al. The outcome of intraarticular distal radius fractures treated with fragment-specific fixation. J Hand Surg Am 2006;31A:1333–1339.
3. Fernandez DL, Jupiter JB. Fractures of the Distal Radius, 2nd ed. Springer, 2001:42–50.
4. Konrath G, Bahler S. Open reduction and internal fixation of unstable distal radius fractures: results using the TriMed system. J Orthop Trauma 2002;16:578–585.
5. Leslie BM, Medoff RJ. Fracture-specific fixation of distal radius fractures. Tech Orthop 2000;15:336–352.
6. Medoff R. Essential radiographic evaluation for distal radius fractures. Hand Clin 2005;21:279–288.
7. Schnall S, Kim B, Abramo A, et al. Fixation of distal radius fractures using a fragment specific system. Clin Orthop Relat Res 2006;445: 51–57.
8. Swigart C, Wolfe S. Limited incision open techniques for distal radius fracture management. Orthop Clin North Am 2001;30:317–327.