Secondary Logo

Fixation of Distal Radius Fractures Using a Fragment-specific System

Schnall, Stephen, B*; Kim, Bill, J; Abramo, Antonio; Kopylov, Philippe

Section Editor(s): Meals, Roy A MD, Guest Editor; Harness, Neil G MD, Guest Editor

Clinical Orthopaedics and Related Research: April 2006 - Volume 445 - Issue - p 51-57
doi: 10.1097/01.blo.0000205900.05986.a3
SECTION I: SYMPOSIUM: Problem Fractures of the Hand and Wrist
Free
SDC

Operative treatment for distal radius fractures continues to evolve, but small-fragment fixation has some advantages compared with previous methods. We assessed two groups of patients. Group 1 was an initial series of patients treated with small-fragment fixation at a large institution in the United States, and Group 2 was a review of patients treated in Lund, Sweden. The first group was evaluated for return to routine activity. Return to work or routine daily activity averaged 6 weeks (range, 3-16 weeks). The second group was evaluated for early grip strength and range of motion compared with the uninjured extremity. The grip strength at final followup averaged 67% compared with the uninjured extremity. Wrist flexion averaged 46°, extension averaged 57°, pronation averaged 80°, and supination averaged 73°.

Level of Evidence: Therapeutic study, level IV. See the Guidelines for Authors for a complete description of levels of evidence.

From the *Department of Clinical Orthopaedics and Surgery, Keck School of Medicine, University of Southern California, Los Angeles, California; the †University of Southern California/Joseph Boyes Fellowship, University of Southern California, Los Angeles, California, and the ‡Department of Orthopaedics, Lund University, Lund, Sweden.

Each author certifies that he or she has no commercial associations (eg, consultations, stock ownership, equity interest, patent/licensing arrangements etc.) that might pose a conflict of interest in connection with the submitted article.

Correspondence to: Stephen B. Schnall, MD, Clinical Orthopedics and Surgery, Keck School of Medicine, University of Southern California, 1520 San Pablo Street, Suite 2000, Los Angeles, CA 90033. Phone: 323-442-6941; Fax: 323-442-6990; E-mail: schnall@usc.edu.

Distal radius fractures are one of the most common injuries seen in the adult population. Abraham Colles originally described the clinical presentation and treatment of distal radius fractures. Since then, radiographs have allowed for better assessment and description of the fractures. This has led to as many as 10 different classification systems.2,8-10,13,15,18 They are utilized for descriptions but do not specifically address prognosis or treatment and have been shown to have variations in interobserver reliability.2

Restoration of the articular surface congruity to a residual displacement of less than 2 mm has been suggested as helpful in avoiding development of arthritic changes, loss of range of motion (ROM), and diminished function.4,6,10,11,13,14,19-21 There is still a controversy whether restoring joint surface integrity or restoring anatomic measurements of the distal radius is more important for obtaining optimal results.11,25,27

Treatment for these common but difficult fractures has evolved from primarily closed reduction and immobilization to complex open reduction and plating techniques.3,4,6,8,9,13-15,18,19,22 The various treatment methods include closed reduction with and without Kirschner wire (K-wire) fixation, external fixation, and open reduction and internal fixation (ORIF).1,3,22,23 However, a consistent and reproducible method of restoring joint congruity, anatomic alignment, and good functional outcome remains elusive.22,23,27 Closed reduction methods with or without K wire fixation and external fixation devices can restore all parameters and joint surface integrity, but usually requires at least 6 weeks to 8 weeks of immobilization and often leads to wrist and finger stiffness.11,25 Various implants have been introduced to achieve solid fixation, and may shorten the length of time necessary for wrist immobilization.17 However, the some of the plates and screws that have been developed are high profile and have led to tendon irritation and/or rupture.7,12,16 The fixed designs4,13,20 of standard plates for various types of fractures often preclude addressing the separate fragments individually.

Fragment-specific fixation (TriMed® Valencia, CA), as developed and popularized by Medoff and Kopylov,17 relies on a relatively simple assessment of the pattern of a distal radius fracture (Figs 1, 2) and then uses a fixation system to address each particular area. The TriMed® fixation system was introduced to accommodate the wide variety of distal radius fracture patterns, and can achieve rigid fixation because it is based on fragment specific pin plates and screws. Fixation can be customized to produce optimal rigid anatomic fixation secure enough to allow early motion postoperatively. This was a new approach that used small low-profile plates, pins, and screws that could be applied to separate fragments rather than one large plate to buttress the fracture or K wires alone to secure fragments. Support for this concept of small-plate fixation has been shown.9,17,25 A double plating fixation system comprised of two 2-mm titanium plates placed 60° to each other was compared in a biomechanical model with the AO T plate and pi plate.21 The two titanium plates had superior stiffness.21 The double plating fixation system has also been shown to have mechanical stability and advantages over external fixation devices.10,25

Fig 1

Fig 1

Fig 2

Fig 2

We wondered whether this fragment specific fracture fixation system would offer an alternative method of treating distal radius fractures. Specifically we asked whether fragment-specific fixation could achieve early return to normal activities, functional range of motion and early return of grip strength and whether the results would be reproducible between two cohorts in differing institutions.

Back to Top | Article Outline

MATERIALS AND METHODS

We retrospectively reviewed two groups of patients at different facilities and several years apart to add support for our results being reproducible. Both groups had the same implants. One group (Group 1) included the first 20 patients with 20 intraarticular distal radius fractures treated with the TriMed® fixation system from November 1998 to March 2000 at the University of Southern California. The second group of 17 patients was treated in an institution in Lund, Sweden from September 2003 to December 2004.

In Group 1, many of the fractures involved high-energy mechanisms and had a high degree of comminution. Two patients were excluded leaving 18 for study. One patient presented with a distal radius malunion and underwent corrective osteotomy with the TriMed® system. Another patient presented with an intra-articular distal radius fracture and originally was treated with external fixation. This patient had an inadequate reduction and had definitive ORIF with the TriMed® system. The remaining 18 patients had an average of 32 years (range, 19-55 years). There were 10 men and eight women. Fifteen patients sustained the fracture through a fall, and three patients were injured in motor vehicle accidents. One patient had an ipsilateral concomitant injury that was a displaced scaphoid fracture. These 18 patients were observed for an average of 6.5 months (range, 6 weeks-9 months).

All 18 patients met criteria for operative ORIF based on clinical and radiographic examination. All fractures were intraarticular with varying degrees of comminution. Considerable loss of volar tilt (>20° of dorsal angulation), excessive radial shortening (>5 mm), or articular displacement (>2 mm) were indications for operative reduction. Patients were evaluated by emergency room physicians and/or orthopedic residents, had their fractures splinted, and were then evaluated by the orthopaedic hand service for definitive treatment. Seven of the 18 patients initially were treated with attempted closed reduction. The remaining 11 patients had fractures with comminution and articular incongruence. No manipulations were performed preoperatively. The time to operative fixation averaged 8.5 days (range, 3-27 days). Preoperative planning included standard posterior anterior and lateral radiographs. Postoperative immobilization consisted of volar splints placed for 1 week to 3 weeks. All patients were encouraged to perform finger exercises immediately postoperatively. Occupational therapy was implemented for 15 of 18 patients. The other three were scheduled for occupational therapy but did not comply.

Group 2 included 17 patients with 17 intraarticular distal radius fractures treated from September 2003 to December 2004 at the University of Lund using same system (Group 2). Patients were an average of 53 years (range, 36-82 years). Bone supplement Norian SRS® was used in two patients. The time from injury to operation ranged from 2 days to 16 days. These 17 patients were observed for an average of 6 months (range 5 weeks-30 months).

The TriMed® fixation system involves fragment specific fixation system. Because of its specificity in hardware, this system is adaptable to almost all distal radius fracture patterns. All procedures were performed with fluoroscopic imaging and general anesthesia. All fractures were approached through a two-incision exposure. The initial part of the exposure involves a volar approach to the wrist between the flexor carpi radialis and the radial artery. The first dorsal compartment is identified while carefully protecting the radial artery and superficial radial nerve braches. The first dorsal extensor compartment is then incised (leaving the distal 0.5-1 cm of the extensor retinaculum of the first dorsal extensor compartment intact if desired), and the abductor pollicis longus and extensor pollicis brevis tendons are mobilized. The bare spot on the distal most aspect of the radial styloid just dorsal to these tendons is identified. To facilitate mobilization of the radial column fragment, the brachioradialis muscle can be released from its insertion on the distal radius. A preliminary reduction is performed and an initial 0.045 K-wire is driven from the bare spot of the radial styloid obliquely through the radial styloid fragment and into the radial shaft. Optimally, this K-wire should exit the radial shaft in the interosseous space. One should avoid a dorsal or volar exit because the pin could irritate the tendons and leave little room for the subsequent fixation. The dorsal fragments then are addressed through a longitudinal dorsal incision initially centered at Lister's tubercle by dissecting between the third and fourth dorsal compartments. Inspection of the fragments may determine which components will be used for fixation. The presence of a dorsoulnar fragment warrants fixation of that fragment with the specifically contoured dorsoulnar pin plate that uses two 0.045 K-wires and 2.4-mm cortical screws to secure fixation. If there are small dorsal cortical fragments, small wire forms and buttress pins can be used to provide stability for the small fragments without inducing further comminution to the small fragments. Bone substitute with autogenous or allograft also can be used.

After securing the dorsal components of the fracture the radial styloid fragment and column are secured with the radial column pin plate. This is secured underneath the tendons of the first dorsal compartment. The radial pin plate is placed over the initially placed K-wire, and the plate is secured to the radial shaft using 2.4-mm screws. This securely fixes the reduced radial column to the shaft. The plate follows the contour of the radius and its flare, giving rigid fixation with a low profile and minimal surrounding soft tissue irritation. A second 0.045 K-wire is placed through a remaining distal pinhole in the plate. These K-wires (as with the ones used for the dorsoulnar pin plate) are cut and bent using a specialized three-point bending pliers to allow impaction, and the cut end is impacted into a remaining hole of the plate. Volar rim fragments may occur in isolation or part of the fracture of several fragments. Large fragments of articular surfaces can be stabilized with the volar buttress plate. These plates also are low in profile and usually can be placed through the same volar incision by reflecting the pronator quadratus muscle. Smaller fragments also can be addressed using the wire forms including the more recently developed ulnar buttress pin that is helpful in addressing the volar ulnar intra-articular fragments (Figs 3-5).

Fig 3

Fig 3

Fig 4

Fig 4

Fig 5A

Fig 5A

Patients were immobilized with a short-arm plaster splint for 5 days to almost 4 weeks (the duration of the plaster splint decreased as confidence in the system increased). After that time a removable splint was used for 2 to 4 more weeks, and range of motion exercises were begun but giving the patient the option of using the protective splint for daily activities if desired. In Group 1, earlier patients were immobilized for 3 weeks to 3.5 weeks, the patients at the latter part of study were only immobilized for 2 weeks.

We determined time of return of function and return to daily activities or employment. A clinical examination was performed to determine the presence of skeletal deformities, evidence of nonunion, or irritation from the fixation. For Group 1 range of motion and grip strength of the affected wrist were measured by an orthopaedic resident, hand fellow, or faculty member. The range of motion measurements and grip strength were recorded at 1 month, 3 months, and 6 months and available for all 18 patients. In group 2, the complete data for range of motion and grip strength were available for 14 of the 17 patients.

Back to Top | Article Outline

RESULTS

In Group 1, the average time required returning to normal activities or regular employment was 6 weeks (range, 3-16 weeks). The duration of time between surgery and return to employment was the time before preoperative work duties and not modified work duties. Two patients had a prolonged period of convalescence because of multiple associated injuries.

None of the 18 patients in Group 1 had wrist or forearm deformities. After 6 weeks no patient had pain at the fracture site. There was no evidence of loss of fixation 6 weeks postoperatively.

At 6 months postoperatively the average wrist extension was 55° (range, 20-70°), the average wrist flexion was 52° (range, 20-70°), the average supination was 52° (range, 30-70°), and the average pronation was 58° (range, 30-75°). Grip strength was recorded with three successive measurements with a Jamar® dynamometer (Preston, Jackson, MI).

We identified no intraoperative complication. Of the 18 patients, two had minor postoperative hardware complications. One patient had persistent dorsal wrist pain that was localized to the region of the dorsal ulnar pin plate. This plate was removed 6 months after the original surgery with resolution of symptoms. The second patient began developing pain at the volar wrist region 9 months postoperatively, which led to the removal of the L volar plate after 1 year.

In Group 2, the average grip strength was 67% of the uninjured extremity (range, 31-100%). The average wrist flexion was 45° (range, 30-80°), the average wrist extension was 52° (range, 30-80°), the average pronation was 80° (45-90°), and the average supination was 73° (45- 90°) (Table 1). Radiographic assessment showed excellent restoration of joint congruity, volar tilt, and ulnar variance. At surgery the initial correction of volar tilt averaged 22° (as measured from the initial dorsal displacement), joint congruity was restored to 1.8 mm, and ulnar variance to 2 mm. At final followup there was only a 2° loss of the initial correction of the dorsal angulation, no loss of joint congruity, and 0.3 mm of change in ulnar variance.

TABLE 1

TABLE 1

Comparison of range of motion at 6-month followup demonstrated similar results with the exception of pronation supination (Table 1). According to the work of Brumfield5 all ranges and grip strengths allow for activities of daily living.

We present one patient (Patient 1) from Group 1 with a distal radius fracture. The patient was a construction worker who fell 10 feet and sustained a distal radius fracture. No other injuries were incurred. After having ORIF with this fragment-specific system he returned to work 6 weeks postoperatively (Fig 6). This shows that solid fixation and ability to return to strenuous activity has been accomplished by fragment-specific fixation.

Fig 6A

Fig 6A

Fig 6

Fig 6

Back to Top | Article Outline

DISCUSSION

In order to evaluate the possible advantages of newer concept of internal fixation using small fragment specific implants (Trimed® system) in allowing patients early return to daily activities and restoration of a functional range of motion we focused our study on two groups of patients treated several years apart and at separate institutions to document these parameters and the reproducibility of good results by different surgical groups.

Limitations of this study include restricted followup and two separate cohorts evaluated and treated by separate groups of medical personnel. Group 1 patients were treated between 1998 and 2000 and represented the initial use of the fragment specific fixation system, while Group 2 patients were treated between 2003 and 2005 at a different institution by surgeons with greater experience with the system. Both groups however, had a followup average of about 6 months. Absolute comparisons cannot be made because the surgeons had different periods of time to become familiar with the system. However, patients in both groups obtained range of motion that is within parameters needed for activities of daily living.5

Optimum treatment for distal radius fractures still is unknown and achieving consistently good outcomes for intraarticular distal radius fractures remains a surgical challenge. Maintaining articular congruency is important in preventing radiocarpal osteoarthritis with subsequent loss of motion and pain.4,8,9,11,13-15,27

Two components for achieving successful treatment of these types of fractures are meeting radiographic criteria for acceptable reduction, joint congruity, and radiographic parameters, and maintaining reduction until solid union has been achieved. This enables the patient to return to their preinjury functional status.

There have been many methods for stabilizing distal radius fractures. Casting and immobilization have been used for treating extraarticular Colles' fractures, but they are not the primary choice for treating intraarticular fractures of the distal radius.1-3

The method of treating fractures as a result of a high energy impact with soft tissue damage has evolved from plaster to pins to various plating techniques.8,9,11,14,15,17,22 As noted earlier although there have been numerous classification systems to describe the distal radius fractures, integrating classification systems into treatment plans could be helpful but has not been effective, perhaps because of difficulty in interobserver reliability in classifying fractures.2 Although the classification systems identify many separate fragments in distal radius fractures, prior plate fixation of these fractures depended on a single plate and or stand alone K-wires.

Intraarticular fractures of the distal radius have inherent difficulties such as higher degrees of comminution, small fragments, poor metaphyseal support after impaction, and associated extensive soft tissue injury.1,6,9 Because the fractures involve multiple fragments, addressing these pieces individually may have benefits in more accurate reduction and stable fixation of the fragments.

The TriMed® system is based on fragment specific ORIF principles. Rather than using a specific classification system intra-articular distal radius fractures are interpreted as having four or five major cortical fracture components based on standard posteroanterior and lateral radiographs. Fracture fixation follows several principles: (1) screw fixation usually is reserved for the proximal bone cortex where the thickness allows for adequate purchase; (2) fixation of distal components is based on the strong bone of the ipsilateral radial shaft proximal; (3) shortening of the distal radius from cancellous bone impaction may require grafting for support minimizing collapse; (4) hardware should allow for gliding motion of tendons; (5) exposure should cause minimal disruption to adjacent soft tissue structures; (6) fracture fragments must be manipulated with controlled technique and (7) stability of fixation to allow early range of motion. These are the principles that the TriMed® system applies.

Based on our data, which has shown the ability of fragment-specific fixation systems to provide stable fixation and early return to daily activities, fragment-specific fixation seems to be a reasonable treatment alternative for a difficult fracture.10,17 Our postoperative immobilization protocol shortened as confidence was building in this fixation system. Immobilization was provided by a simple volar wrist splint for 5 to 7 days in patients treated after the study group was compiled. All patients regardless of immobilization time had a successful nontender bony union.

Two of the 18 patients required removal of a component of the fixation. One patient with a very petite wrist eventually had a volar L plate removed, and another patient had a dorsal ulnar plate removed. Both patients had resolution of their symptoms. Intraoperative findings did not reveal obvious tenosynovitis in either patient.

Despite these two minor complications in the initial series of Group 1 patients, the promising results for both groups using TriMed® system addresses the important aspects of treating complex distal radius fractures. These include anatomic fixation that is fragment specific and rigid fixation allowing for early motion.

Back to Top | Article Outline

References

1. Altissimi M, Atheucci R, Fiacca C, Mancini G. Long term results of conservative treatment of fractures of the radius. Clin Orthop Relat Res. 1996;206:202-210.
2. Andersen DJ, Blair WF, Steyers CM Jr, Adams BD, el-Khouri GY, Brandser EA. Classification of distal radius fractures: an analysis of interobserver and interobserver reproducibility. J Hand Surg. 1996;22:574-581.
3. Axelrod TS, McMurtry RY. Open reduction and internal fixation comminute intra-articular fractures of the distal radius. J Hand Surg. 1990;15:1-11.
4. Bradway JK, Amadio PC,Cooney WP III. Open Reduction and internal fixation of displaced comminuted intra-articular fractures of the distal end of the radius. J Bone Joint Surg. 1989;71:839-847.
5. Brumfield RH,Champoux JA. A Biomechanical Study of Normal Functional Wrist Motion. Clin Orthop Relat Res. 1984;187:23-25.
6. Carter PR, Frederick HA, Laseter GF. Open reduction and internal fixation of unstable distal radius fractures with a low-profile plate: A multicenter study of 73 fractures. J Hand Surg. 1998;23:300-307.
7. Chiang PP, Roach S, Baratz ME. Failure of retinacular flap to prevent dorsal wrist pain after titanium Pi plate fixation of distal radius fractures. J Hand Surg. 2002;27A:724-728.
8. Cooney WP, Berger RA. Treatment of complex fractures of the distal radius. Hand Clin. 1993;9:603-612.
9. Cooney WP. Fractures of the Distal Radius-A Modern Treatment Based classification. Orthop Clin North Am. 1993;24:211-216.
10. Dodds S, Cornalissen S, Joss S, Wolfe S. A biomechanical comparison of fragment specific fixation and asymmetrical external fixation for intra-articular distal radius fractures. J Hand Surg. 2003;27:953-964.
11. Fernandez DL, Geissler WB. Treatment of displaced articular fractures of the radius. J Hand Surg. 1991;16:375-384.
12. Fitoussi F. IP WY, Chow SP: Treatment of displaced intraarticular fractures of the distal end of the radius with plates. J Bone Joint Surg. 1997;79:1303-1312.
13. Frykman G. Fractures of distal radius including shoulder hand finger syndrome distinctive in the distal radioulnar joint and impairment of nerve function. Acta Ortho Scand Suppl. 1967;108:1-153.
14. Jupiter JB. Fractures of the distal radius. J Bone Joint Surg. 1991;73:461-467.
15. Jupiter JB, Lipton H. The operative treatment of intra-articular fractures of the distal radius. Clin Orthop Relat Res. 1993;292:48-61.
16. Lucas GL, Fejfar ST. Complications in internal fixation of the distal radius. J Hand Surg. 1998;23:1117.
17. Medoff RJ, Kopylov P. Open reduction and immediate motion of intra-articular distal radius fractures with fragment specific system Arch Am Acad Orthopedic Surg. 1999;2:53.
18. Melone CP Jr. Open treatment for displaced articular fractures of the distal radius. Clin Orthop Relat Res. 1986;202:103-111.
19. Melone CP Jr. Articular fractures of the distal radius. Orthop Clin North Am. 1984;15:217-236.
20. Mueller ME, Nazarian S,Koch P. Classification AO der Fracturen. Berlin, Germany: Springer; 1987.
21. Peine R, Rikli DA, Hoffman R, Duda G, Regazzoni P. Comparison of three different plating techniques for the dorsum of the distal radius: a biomechanical study. J Hand Surg. 2000;25:29-33.
22. Putnam MD, Fischer MD. Treatment of unstable distal radius fractures: Methods and comparison of external distraction and ORIF versus external distraction-ORIF neutralization. J Hand Surg. 1997;22A:238-251.
23. Rayhack JM. Transulnar pinning of displaced radial fractures: A preliminary report. J Trauma. 1989;3:107-114.
24. Roysam GS. The distal radioulnar joint in Colles' fractures. J Bone Joint Surg. 1993;75B:58-60.
    25. Rikli DA, Regazzoni P. Fractures of the distal end of the radius treated by internal fixation and early function. J Bone Joint Surg. 1996;78B:588-592. [Br]
    26. Short WH, Palmer AK, Werner FW,Murphy DJ. A Biomechanical Study of distal radius fractures. J Hand Surg. 1987;12:529-534.
    27. Trumble TE, Schmitt SR, Vedder NB. Factors affecting functional outcome of displaced intra-articular distal radius fractures. J Hand Surg. 1994;19:325-340.
    © 2006 Lippincott Williams & Wilkins, Inc.