Injury, Int. J. Care Injured 42 (2011) Contents lists available at ScienceDirect. Injury. journal homepage:

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1 Injury, Int. J. Care Injured 42 (2011) Contents lists available at ScienceDirect Injury journal homepage: Comparison of angle stable plate fixation approaches for distal radius fractures S. Matschke a, *, A. Wentzensen a, D. Ring b, M. Marent-Huber c, L. Audigé c, J.B. Jupiter b a Klinik für Unfallchirurgie und Orthopädie, Berufsgenossenschaftliche Unfallklinik Ludwigshafen, Unfallchirurgische Klinik an der Universität Heidelberg, Ludwig-Guttmann Strasse 13, D Ludwigshafen, Germany b Massachusetts General Hospital, Harvard Medical School, Boston, USA c AO Clinical Investigation and Documentation, Davos, Switzerland ARTICLE INFO ABSTRACT Article history: Accepted 22 October 2010 Keywords: Distal radius fractures Dorsal plating Volar plating LCP 2-Year follow-up Introduction: The aim of the study was to compare radiological and functional outcomes between volar and dorsal surgical fixation of distal radius fractures using low-profile, fixed-angle implants. Patients and methods: A total of 305 distal radius fracture patients were treated with Synthes locking compression plate (LCP) 2.4- or 3.5-mm fixation using either a volar (n = 266) or dorsal (n = 39) approach. The patients were examined at 6 months, 1 and 2 years for radiological assessment of fracture healing, alignment, reduction and arthritis, as well as the determination of various functional outcome scores. Results: Both groups were comparable with respect to baseline and injury characteristics. The complication rate was higher for the volar approach (15%). No significant differences were observed for Disabilities of the Arm, Shoulder and Hand (DASH) and Short Form (36) Health Survey (SF-36) scores, pain, arthritis grade, grip strength and radiological measurements. However, a significantly better functional outcome represented by a low mean Gartland and Werley score was observed for the volar approach after 6 and 12 months. Significantly higher percentages of dorsal extension, palmar flexion, ulnar deviation and supination angle (relative to the mean contralateral healthy wrist) were also reported for volar approach patients at the 6-month follow-up. Conclusions: Volar internal fixation of distal radius fractures with LCP DR implants can result in earlier and better functional outcome compared with the dorsal approach, yet is associated with a higher incidence of complications. After 2 years, these differences are no longer observed between the two surgical methods. ß 2010 Elsevier Ltd. All rights reserved. Introduction The optimal surgical approach for open reduction and internal fixation (ORIF) of distal radius fractures is debatable. Depending on the displacement of the distal fragment, an anatomically designed locking compression plate (LCP) can be implanted by either a dorsal or a volar approach. In many cases, the operative method is pragmatically chosen independent of fracture morphology. Dorsal plating offers direct exposition and reconstruction of the joint by a capsular incision. 3,26 However, dissection of the extensor retinaculum and plate positioning under this tendon is required, which often leads to tendinitis or ruptures of the extensor tendon 12,23,29 because of mechanical friction caused by the plate or screws. 10 Alternately, locked volar plating provides biomechanical stability for dorsally displaced and comminuted fractures, 16 there is more space between the plate and the flexor tendons and * Corresponding author. Tel.: ; fax: address: matschke@bgu-ludwigshafen.de (S. Matschke). the quadratus pronatus muscle acts as a barrier to minimise irritation to the flexor tendons. The aim of the present study was to examine the radiological and functional outcomes between volar and dorsal surgical fixation of distal radius fractures using low-profile, fixed-angle implants. A subset of patients treated in a prospective cohort study was evaluated to test the null hypothesis that there is no difference in wrist function, health status and radiographic parameters between distal radius fractures treated either by dorsal or volar LCP fixation over a 2-year period. Patients and methods Patients aged between 21 and 80 years, who provided written informed consent prior to study participation, were originally recruited as part of two larger prospective multicentre case series for the evaluation of LCP DR 2.4 mm and 3.5 mm implants (Synthes GmbH, Oberdorf, Switzerland) in the fixation of distal radius fractures. Approval for the study methods and conduct was obtained from the Ethics Committee boards of the participating hospitals. From the clinical journals, retrospective data from /$ see front matter ß 2010 Elsevier Ltd. All rights reserved. doi: /j.injury

2 386 S. Matschke et al. / Injury, Int. J. Care Injured 42 (2011) Table 1 Comparison of patient demographic data. Factors Volar approach Dorsal approach n Mean [%] SD n Mean [%] SD Age Years Gender Male 88 33% 17 44% Female Body mass index a Work before the accident a Yes % 23 59% No DASH score a Score % 25 68% > % 11 30% > % 0 0% > % 0 0% > % 1 3% Concurrent general disease a Yes 80 30% 11 28% No Arthritis grading b,a % 30 77% Dexterity (dominant hand) a Right % 36 92% Left 16 3 Smoking a Yes 65 25% 12 31% No a Numbers do not sum to n = 266 (for the volar approach group) and/or n = 39 (for the dorsal approach group) due to missing values. b Arthritis grading according to Knirk and Jupiter 13 ; 0, none; 1, slight joint space narrowing; 2, marked joint space narrowing, osteophyte formation; 3, bone-on-bone, osteophyte formation, cyst formation. patients with Arbeitsgemeinschaft für Osteosynthese (AO) type 23 distal radius/ulnar (excluding A1) fractures, 18 who had received plate fixation with LCP DR 2.4 mm or 3.5 mm implants, were divided into two groups depending on the operative method undertaken (i.e., volar or dorsal). The decision for using either a volar or a dorsal approach had been made independent of the fracture type and left to the discretion of the surgeon. Any patient who had received an implant with a combined volar/dorsal approach was excluded from the analysis. Further details concerning the original study inclusion and exclusion criteria have been described previously. 9 Baseline and follow-up evaluations All patient evaluations have been described in detail by Jupiter et al. 9 Briefly, general patient demographics and accident/fracture characteristics were documented during hospitalisation. Baseline measurements of the Disabilities of the Arm, Shoulder and Hand (DASH) score using the extended three modular questionnaire 7 and of pain (at rest and during motion) using the visual analogue scale (VAS) where 0 indicates no pain and 10 represents very severe pain, were completed for each patient. The baseline DASH was equivalent to the patient-rated upper limb function that existed 1 week prior to injury, and baseline pain was assessed between the first to third postoperative day. Antero-posterior and lateral radiographs were obtained upon admission, intra-operatively and immediately postoperatively, as well as on subsequent scheduled follow-up evaluations. Patients were followed-up at 6 months, 1 and 2 years. The examinations included measurement of wrist and forearm motion with a goniometer and grip strength using a Jamar Dynamometer (Sammons Preston Roylan, Bolingbrook, IL, USA); functional assessments using the DASH and Short Form (36) Health Survey (SF-36) scores, 28 as well as the physician-rated Gartland and Werley score 4 ; and pain and satisfaction ratings using the 0 10 VAS, where 0 was not satisfied at all and 10 was absolutely satisfied. Range of motion was also assessed. The evaluation of joint alignment, fracture healing and reduction, arthritis grading according to Knirk and Jupiter 13 and the degree of displacement was made from post-surgical radiographs. All radiographic measurements including radial angle, radial length, ulnar variance and articular step-off and gap were evaluated by an independent radiologist and recorded according to the criteria of Kreder et al. 14 All complications were documented up to 2 years. Study population Data from 305 patients, who received volar (266 patients) or dorsal (39 patients) LCP fixation, were available for this comparative analysis. The mean age of the volar approach group was 54 years and included 178 (67%) women and 88 men (33%). Similarly, dorsal approach patients had a mean age of 51 years andincluded56%women(n = 22) and 44% men (n = 17). More than 75% of the patients had no signs of arthritis and a baseline DASH score between 0 and 5. In general, both groups were similar (Table 1). Baseline fracture and surgery characteristics The majority of fractures was sustained after falling from standing height (61%: volar; 79%: dorsal). Only two fractures in the volar group were classified as open injuries according to Gustilo et al. 5 and Tscherne and Oestern 27 and the dominant hand was fractured in 46% and 62% of volar and dorsal approach cases, respectively. The ulna was involved in 59% (volar) and 67% (dorsal) of the fractures and mostly (>70%) located at the styloid base for both groups (Table 2). In the volar group, 110 patients received an LCP 2.4-mm (41%) and 156 (59%) a 3.5-mm plate; the percentages were similar for the

3 S. Matschke et al. / Injury, Int. J. Care Injured 42 (2011) Table 2 Comparison of patient injury characteristics. Factors Volar approach Dorsal approach n % n % Fall from standing height a Yes No Open injury Yes No Dominant hand fractured a Yes No AO classification a A B C Ulna involvement No Yes Ulnar styloid base fracture Styloid tip fracture 21 5 Ulnar neck fracture 19 2 Concurrent injury (except ulna) Yes No a Numbers do not sum to n = 266 (for the volar approach group) and/or n = 39 (for the dorsal approach group) due to missing values. dorsal group (44% (17/39) for LCP 2.4-mm and 56% (22/39) for the 3.5-mm plate). Statistical analysis Patients with a volar surgical approach were compared with those with a dorsal approach and assessed for differences in wrist function and state of health at the designated follow-ups. The Likelihood theory was used to test the null hypothesis that there would be no differences between the two cohorts. All examined parameters (19) for range of motion, radiologic alignment, pain, grip strength, DASH, Gartland and Werley, SF-36 and arthritis grade were assessed at each examination and regressed on two indicator variables: (1) type of surgical approach and (2) follow-up time and one interaction term, i.e., type of surgical approach and time. The interaction term was included to assess whether or not a possible effect of the surgical approach was time dependent. For each outcome, the repeated measurements of each patient were pooled and analysed together in one overall linear regression model. This method allowed the assessment of an overall effect of Table 3 Comparison of functional outcomes. 6 months 1 year 2 years Volar Dorsal Volar Dorsal Volar Dorsal DASH a (points) Gartland & Werley (points) Categorised G&W (%) Excellent Good Fair/poor Range of motion (ROM) (8) b Palmar flexion % Dorsal extension % Radial deviation % Ulnar deviation % Pronation angle % Supination angle % Pain c During rest With motion SF-36 (points) Physical Mental Grip strength (kg) d % a Mean baseline DASH = 3.1 and 1.0 points for the volar and dorsal approach groups, respectively. b Mean ROM measurements for the contralateral (healthy) side: dorsal extension (volar approach) = and (dorsal approach) = 63 14; palmar flexion (volar approach) = and (dorsal approach) = 63 15; radial deviation (volar approach) = 25 8 and (dorsal approach) = 26 8; ulnar deviation (volar approach) = 37 9 and (dorsal approach) = 31 8; pronation angle (volar approach) = 86 6 and (dorsal approach) = 87 3; supination angle (volar approach) = 86 7 and (dorsal approach) = % = % of contralateral wrist. c Mean baseline 0 10 VAS for pain (volar approach) = 4.0 and (dorsal approach) = 5.2. d Mean grip strength measurements for the contralateral (healthy side): (volar approach) = and (dorsal approach) =

4 388 S. Matschke et al. / Injury, Int. J. Care Injured 42 (2011) the surgical approach type and time on the outcome, whilst considering all available data and avoiding multiple analyses at each follow-up. In addition, the surgical approach effect at each follow-up within the same model could be quantified. The Likelihood Ratio Test was used to observe any overall effect of surgical approach type on each outcome parameter, whereby the maximum likelihood estimate of the full regression model (including surgical approach type, time and interaction term) was compared with that of a null regression model (time only) to see whether adding the surgical approach type variable would significantly improve the model. An important value of this test reflects a significant difference in outcome due to the dorsal approach group (compared with the volar approach group). In a similar fashion, the full regression model was compared with a model without the time variable to determine the overall time effect on outcome. Statistical significance was adjusted for multiple testing using a Bonferroni correction: a p-value of less than (0.05/19) was considered significant. The same full regression model was then used to determine the effect size (i.e., group differences) and timing at 6 months, 1 and 2 years using the Wald test. All statistical analyses and graphs were conducted with the software Intercooled Stata Version 9 (StataCorp LP, College Station, TX, USA). Results The mean baseline DASH scores for the volar and dorsal groups were 3.1 points (range: points) and 1.0 point (range: points), respectively. At 1 year, the mean DASH scores increased and by 2 years, a decrease was observed although pre-injury scores were not obtained. There were no significant differences between the surgical approaches (p = 0.004) (Table 3). According to Gartland and Werley, the mean scores for the volar approach group were significantly different to those for the dorsal approach group at 6 months and 1 year only (p > 0.003) (Table 3). The proportion of fractures categorised as good and excellent was 75% for both groups at all time points. By 2 years, 35% (50/142) of volar-treated patients with intraarticular fractures had an increase of at least one grade in radiographic signs of arthritis and eight patients (6%) had an increase of at least two grades; these proportions were statistically similar to that for the dorsal cohort (p = 0.88). The mean ranges of dorsal extension, palmar flexion, ulnar deviation and supination angle as compared with the healthy contralateral side for volar approach patients at 6 months were 88%, 81%, 84% and 94%, respectively (Table 3); this outcome was significantly higher than the equivalent percentages achieved for the dorsal approach (p 0.001). By the 1- and 2-year examinations however, no further differences were observed between the two treatment groups (p 0.32). Mean absolute values and relative percentages compared with the contralateral side for radial deviation and pronation angle were similar between the study groups at all time points (p 0.17 and p 0.05, respectively). Pain at the fracture site decreased between baseline and all follow-up examinations without any significant difference observed between the groups (p = 0.005) (Table 3). The combined SF- 36 physical and mental health composite scores obtained at 1 and 2 years also showed no significant difference between cohorts (p = 0.12) (Table 3). Grip strength did improve to 90% and 95% of the mean healthy side for the volar and dorsal groups, respectively, by 2 years (Table 3). Nevertheless, there was no statistical significance between the mean absolute and relative (to the healthy wrist) grip strength values reported for both treatment groups (p = 0.30). Radiological outcomes For the volar approach, the mean radial angle was and mean palmar tilt was 3.08 at 2 years. For the same time point, dorsal approach patients achieved average radial angle and palmar tilt values of and 9.18, respectively. The 2-year ulnar variance measurements for both groups were also similar (volar: 3 mm; dorsal: 4 mm) and the majority of patients recorded minimal secondary loss of reduction (i.e., ulnar variance values fell within the range of 0 1 mm) up to the last follow-up examination. No significant differences were observed between the treatment groups for all radiological outcomes up to 2 years (p 0.03). An articular step-off was only recorded at the 2-year follow-up for six patients with a volar approach. At this time point, 25% (50/ 201) of the volar group and 19% (5/27) of the dorsal group also had an increase of at least one grade in radiographic signs of arthritis after having shown no radiographic signs of arthritis at baseline. Complications Forty-three complications were reported for 39 patients, who received a LCP via the volar approach (Table 4). Twenty-three of the 43 adverse events occurred within the 6-month postoperative period. There were 17 major complications, 10 of which required a return to the operating table to revise the problem. Most of the complications were described as soft tissue/wound problems (n = 32) and included eight cases of tendinitis due to irritation directly caused by the plate; implant removal was performed for five patients. Various other soft-tissue problems were noted in another eight patients and included extension deficit of the distal interphalangeal joint (digits II V), thumb dysesthesia, paraesthesia of the hand that disappeared with movement and massage, a ganglion cyst on the extensor pollicis longus, arthrofibrosis and radial avulsion of the triangular fibrocartilage complex, an ulnar nerve (dorsal branch) irritation due to a Kirschner wire (which was later removed), blocked flexion due to the LCP constricting the flexor carpi radialis, a palmar median nerve lesion with thumb dysesthesia; the implants were removed for the last two complications described. Table 4 List of reported complications. Complications Volar approach Dorsal approach Soft tissue/wound 32 3 Infection 1 Healing problems 6 Carpal tunnel syndrome 5 Tendinitis 8 1 Tendon rupture 4 1 Other soft tissue problems 8 1 Implant/surgery 6 n.r. Loss of reduction 2 Screw loosening 1 Plate/screw pull out 1 Other implant/surgery problems 2 Bone/fracture 4 n.r. Loss of reduction 3 Healing problems 1 General 1 n.r. Death 1 Total number of complications 43 3 Complication risk (%) a 15% 5% n.r. = not reported. a The complication risk estimation for experiencing at least one local complication; there were 39 local complications and a total of 266 fractures for the volar approach group and 2 local complications and a total of 39 fractures for the dorsal approach group at risk of experiencing complications.

5 S. Matschke et al. / Injury, Int. J. Care Injured 42 (2011) Three complications were reported in two dorsal approach patients. Only one was described as a major complication (i.e., extensor pollicis longus tendon rupture) between the 1- and 2-year follow-up examinations; this occurred in the same patient, who needed a re-operation between 6 months and 1 year to release a flexion contracture of a proximal interphalangeal joint. The estimated risk of experiencing at least one local complication using the dorsal approach was 5%, whereas this risk was threefold greater (i.e., 15%) for volar surgery. A calculated odds [()TD$FIG] ratio of 0.33 (95% confidence interval (CI): ) indicates that a complication is less likely to occur in the dorsal group. Discussion The data from this comparative study confirm the efficacy of open reduction and internal LCP fixation of distal radius fractures using either a volar or dorsal approach. Most of the patients attained greater than 80% of their wrist motion (compared with the Fig. 1. Pre- and postoperative anteroposterior (AP) and lateral radiographs of an AO Type 23 A2 fracture with LCP 3.5 mm fixation using a volar approach.

6 390 S. Matschke et al. / Injury, Int. J. Care Injured 42 (2011) average opposite arm), greater than 85% grip strength capacity and similar levels of pain and general well-being at the final 2-year evaluation. Patients receiving volar LCP fixation, however, sustained more complications with around half of the problems considered as implant related. Only a handful of comparative studies analysing the dorsal and volar approaches have been published, 15,20,24 yet they have been unable to provide conclusive evidence to support a single, specific surgical technique. Ruch and Papadonikolakis reported higher rates of volar collapse and late complications associated with dorsal plating in a retrospective review of 34 patients with intraarticular fractures. 24 Contrary to this, better outcomes were [()TD$FIG] reported for 53 patients who received a T-plate via a dorsal approach. 15 The most current dorsal volar comparison of 29 patients with AO C3 fractures revealed that satisfactory functional and subjective results could indeed be achieved using either procedure after a mean follow-up time of 22 months, although a greater number of complications were seen after dorsal plate osteosynthesis. 20 Recommendations of careful follow-up evaluation and plate removal 4 6 months after fixation were suggested to alleviate the dorsal surgery problems. Our study achieved outcomes similar to that of Rein et al. 20 (i.e., dorsal and volar fixation were equally satisfactory) within a comparable time frame of 2 years. However, we documented more complications after Fig. 2. Pre- and postoperative anteroposterior (AP) and lateral radiographs of an AO Type 23 C2 fracture with LCP 2.4 mm fixation using a dorsal approach.

7 S. Matschke et al. / Injury, Int. J. Care Injured 42 (2011) volar plate osteosynthesis; this may be explained in part by the apparent learning curve of the surgeons. At the beginning of the study, volar plating of distal radius fractures, especially for dorsally comminuted fractures, was a relatively new procedure (Fig. 1). A correlation between the complication rate and the training course of the surgeons is beyond the scope of this analysis. In addition, palmar plating of fractures that were in fact situated dorsally led to irritations caused directly by the LCP in some cases of tendinitis and tendon rupture. From our experience however, there are only a few specific indications for dorsal plating, particularly when anatomical repositioning with a palmar approach is not possible, for example, a dorsal comminuted fracture combined with dorsally dislocated fragments, dislocated ulnar-edge fragments or even a scapholunate dislocation that requires reconstruction in one operative session (Fig. 2). Based on the radiological outcomes, metaphyseal and/or dorsally displaced fractures, which were treated with a LCP DR 3.5 mm or 2.4 mm without bone graft, achieved adequate healing and alignment in the majority of patients, independent of the type of surgical approach. Similar postoperative anatomical reduction (i.e., radial angle) was achieved. Adequate palmar tilt was also reported with dorsal plating; however, complete physiological reconstruction using the volar approach was not obtained. Nevertheless, the volar group had increased ranges of extension, flexion, supination and ulnar deviation at the earlier follow-up evaluations, followed by similar overall ranges of motion compared with the dorsal plated patients at 2 years. This 2-year outcome is confirmed by Ruch and Papadonikolakis 24 and Rein et al. 20 We recommend a follow-up period of 2 years to fully assess functional outcomes and ensure that any true differences are observed. Interestingly, Ruch and Papadonikolakis 24 found better wrist pronation for volar-plated patients at 22 months, which highlights the importance of our proposal. Prior studies have noted that dorsal plating is associated with a high rate of local irritations and ruptures of the extensor tendon. 21,22 Ring et al. 21 reported an implant-related complication rate of 18%, where 4 out of 27 pi plates required removal within the first 6 months. These tendon problems result from the dorsal plate design, which frequently does not allow for sufficient positioning directly on the bone. In addition, small fragments usually cannot be fixed with this plate. 6,8,11,21 A significant correlation between extensor tendon ruptures and implant design, thickness and its metallurgical characteristics has been reported. 11,17,25 In 20 30%, the dorsal plate was removed due to tendinitis. 6 Even when a volar approach is chosen, an increased rate of up to 8.6% for extensor pollicis longus tendon ruptures has been reported. 1,2,19 The rates of extensor tendon rupture or tendinitis reported in our study for volar (4.5%) and dorsal plating (5.1%) fall within the range described in the literature. Some limitations include the fact that our study was not randomised and the decision to use a dorsal or volar surgical approach was left to the treating surgeons. Despite having similar baseline characteristics, both groups may still differ with regard to unknown factors, potentially confounding our results. In addition, since the volar approach was favoured, only a limited number of 39 patients treated by dorsal approach was documented. The resulting loss in statistical power was mitigated by the otherwise much larger group of 266 patients treated by the volar approach, as well as taking into account all available information by repeatedmeasure modelling techniques. Furthermore, the overall numbers far exceed those included in any current related publication. It would be interesting to see whether the 2-year outcomes reported from our study would be significantly different in a larger prospective study. On the basis of our secondary analysis, we conclude that patients with a distal radius fracture can expect a similar and satisfying outcome 2 years after volar or dorsal surgery. Because shorter follow-up periods demonstrate only temporary benefits of volar plating, longer follow-up periods over 12 months are recommended. Surgical techniques should be improved to minimise soft-tissue complications related to the fixation of angle stable locking plates via palmar insertion. Conflict of interest statement The authors were not supported by any specific grant funding for this work. References 1. Al-Rashid M, Theivendran K, Craigen MA. Delayed ruptures of the extensor tendon secondary to the use of volar locking compression plates for distal radial fractures. J Bone Joint Surg Br 2006;88: Arora R, Lutz M, Hennerbicher A, et al. Complications following internal fixation of unstable distal radius fracture with a palmar locking-plate. J Orthop Trauma 2007;21: Blythe M, Stoffel K, Jarrett P, Kuster M. Volar versus dorsal locking plates with and without radial styloid locking plates for the fixation of dorsally comminuted distal radius fractures: a biomechanical study in cadavers. J Hand Surg [Am] 2006;31: Gartland Jr JJ, Werley CW. Evaluation of healed Colles fractures. J Bone Joint Surg Am 1951;33-A: Gustilo RB, Mendoza RM, Williams DN. Problems in the management of type III (severe) open fractures: a new classification of type III open fractures. J Trauma 1984;24: Herron M, Faraj A, Craigen MA. Dorsal plating for displaced intra-articular fractures of the distal radius. Injury 2003;34: Hudak PL, Amadio PC, Bombardier C. Development of an upper extremity outcome measure: the DASH (Disabilities of the Arm, Shoulder and Hand). The upper extremity collaborative group (UECG). Am J Ind Med 1996;29: Jupiter JB. Plate fixation of fractures of the distal aspect of the radius: relative indications. J Orthop Trauma 1999;13: Jupiter JB, Marent-Huber M, LCP Study Group. Operative management of distal radial fractures with 2.4-millimeter locking plates. A multicenter prospective case series. J Bone Joint Surg Am 2009;91: Kamath AF, Zurakowski D, Day CS. Low-profile dorsal plating for dorsally angulated distal radius fractures: an outcomes study. J Hand Surg [Am] 2006;31: Kambouroglou GK, Axelrod TS. Complications of the AO/ASIF titanium distal radius plate system (pi plate) in internal fixation of the distal radius: a brief report. J Hand Surg [Am] 1998;23: Keller M, Steiger R. The pi plate: an implant for unstable extension fractures of the distal radius in patients with osteoporotic bone. Tech Hand Up Extrem Surg 2004;8: Knirk JL, Jupiter JB. Intra-articular fractures of the distal end of the radius in young adults. J Bone Joint Surg Am 1986;68: Kreder HJ, Hanel DP, McKee M, et al. X-ray film measurements for healed distal radius fractures. J Hand Surg [Am] 1996;21: Letsch R, Infanger M, Schmidt J, Kock HJ. Surgical treatment of fractures of the distal radius with plates: a comparison of palmar and dorsal plate position. Arch Orthop Trauma Surg 2003;123: Liporace FA, Kubiak EN, Jeong GK, et al. A biomechanical comparison of two volar locked plates in a dorsally unstable distal radius fracture model. J Trauma 2006;61: Lowry KJ, Gainor BJ, Hoskins JS. Extensor tendon rupture secondary to the AO/ ASIF titanium distal radius plate without associated plate failure: a case report. Am J Orthop 2000;29: Müller ME, Nazarian S, Koch P, Schatzker J. The comprehensive classification of fractures of long bones. Berlin: Springer-Verlag; Orbay JL, Fernandez DL. Volar fixed-angle plate fixation for unstable distal radius fractures in the elderly patient. J Hand Surg [Am] 2004;29: Rein S, Schikore H, Schneiders W, et al. Results of dorsal or volar plate fixation of AO type C3 distal radius fractures: a retrospective study. J Hand Surg [Am] 2007;32: Ring D, Jupiter JB, Brennwald J, et al. Prospective multicenter trial of a plate for dorsal fixation of distal radius fractures. J Hand Surg [Am] 1997;22: Rozental TD, Beredjiklian PK, Bozentka DJ. Functional outcome and complications following two types of dorsal plating for unstable fractures of the distal part of the radius. J Bone Joint Surg Am 2003;85: Rozental TD, Blazar PE. Functional outcome and complications after volar plating for dorsally displaced, unstable fractures of the distal radius. J Hand Surg [Am] 2006;31: Ruch DS, Papadonikolakis A. Volar versus dorsal plating in the management of intra-articular distal radius fractures. J Hand Surg [Am] 2006;31: Schnur DP, Chang B. Extensor tendon rupture after internal fixation of a distal radius fracture using a dorsally placed AO/ASIF titanium pi plate. Arbeitsgemeinschaft für Osteosynthesefragen/Association for the Study of Internal Fixation. Ann Plast Surg 2000;44:564 6.

8 392 S. Matschke et al. / Injury, Int. J. Care Injured 42 (2011) Trease C, McIff T, Toby EB. Locking versus nonlocking T-plates for dorsal and volar fixation of dorsally comminuted distal radius fractures: a biomechanical study. J Hand Surg [Am] 2005;30: Tscherne H, Oestern HJ. A new classification of soft-tissue damage in open and closed fractures. Unfallheilkunde 1982;85: Ware Jr JE, Sherbourne CD. The MOS 36-item short-form health survey (SF-36). I. Conceptual framework and item selection. Med Care 1992;30: Willis AA, Kutsumi K, Zobitz ME. Cooney WP 3rd. Internal fixation of dorsally displaced fractures of the distal part of the radius. A biomechanical analysis of volar plate fracture stability. J Bone Joint Surg Am 2006;88: