unstable distal radius fractures requiring surgery have long been treated with diverse techniques including pinning , external fixation , nailing , and plating.12 open reduction and internal fixation with locking distal radius plates have become very popular over the last 10 years.345 however , controversy still exists regarding the complications associated with current implants and fracture patterns that are not amenable to those surgical techniques.678 low - profile dorsal plates were developed to address these problems by providing bicolumnar fixation and minimizing extensor tendon complications.910 to date , few studies have described the effectiveness of or the complications associated with minimally invasive plate osteosynthesis ( mipo ) techniques using these new implants.11 we studied the radiographic and functional outcomes of bicolumnar plating osteosynthesis through a minimally invasive dorsal approach in unstable distal radius fractures .
thirty patients with unilateral distal radius fracture who underwent bicolumnar plate fixation with a minimally invasive dorsal approach between september 2008 and december 2010 were included in this retrospective study . in the end ,
24 of 30 patients underwent clinical followup at 1 year or more were finally included in study [ table 1 ] . there were 8 men and 16 women , with an average age of 53 years ( range 1885 years ) .
ten fractures were attributed to a simple ground fall and 14 fractures were due to either a fall from more than standing height or a traffic collision ; two were work - related fractures .
the eligibility criteria were dorsally unstable fracture of the distal part of the radius [ figure 1 ] .
fracture patterns were categorized according to the mller - ao comprehensive classification12 and were confirmed by an independent orthopedic specialist .
fractures of ao type a1 and b3 were intentionally excluded from our study since neither of these fracture patterns indicated dorsal plating fixation . according to the ao classification , 3 of the fractures were type a , 5 were type b , and 16 were type c. the type c fractures included 9 c1 fractures , 5 c2 fractures , and 2 c3 fractures .
the average time interval between injury and surgery was 2 days ( range 16 days ) .
we used the gartland and werley scoring system13 for assessment of functional outcome with modification based on sarmiento et al .
's criteria of the minimum in range of motion ( rom ) for normal function , which consisted of extension ( 45 ) , flexion ( 30 ) , radial deviation ( 15 ) , ulnar deviation ( 15 ) , pronation ( 50 ) , and supination ( 50).14 standard preoperative and postoperative posteroanterior and lateral wrist radiographs were obtained for each patient .
we recorded radiographic parameters from the electronic images ( centricity enterprise web 3.0 ; ge medical systems , paris , france ) such as the degree of volar angulation , radial inclination ( ri ) angle , and radial height ( rh ) [ figure 2 ] .
routine followup radiographs were taken in the clinic at 6 weeks , 3 months , and 1 year after surgery . statistical analysis with a two - sample t - test
was used to determine the significance of differences in radiographic parameters between postoperative radiographs and those of the 1-year followup .
radiographs of the wrist joint anteroposterior and lateral views of an 18-year - old male showing a dorsally displaced , ao type c1 fracture of the distal radius with displaced fracture of the ulnar styloid radiographic parameters were measured from the electronic images including radial inclination ( ri ) angle , radial height ( rh ) and volar tilt ( vt ) angle all operations were performed by the single surgeon ( chen , ac - y ) . under general anesthesia , distal radius fractures were reduced and fixed temporarily by kirschner - wire ( k - wire ) after realignment was confirmed using a mini c - arm image intensifier .
two k - wires were used to secure the dorsal lunate facet fragment for correction of dorsal angulation .
a 1 cm skin incision was made distal to the fracture side along the intermediate column and was directly deepened to enter the fourth compartment .
the extensor tendons were then protected and retracted toward the ulna to explore the dorsal lunate fragment .
blunt dissection was performed using a freer elevator underneath the extensor tendons until it met the second incision proximal to the fracture site .
the extensor retinaculum was partially released in the distal half , and the dorsal locking plate ( synthes ltd . ,
paoli , pa , usa ) was inserted along the ulnar border of the distal radius . in most cases ,
the dorsal locking plate was precontoured at the distal end to allow caudocephalic placement of locking screws in the subchondral area of the distal fragment .
the radial sensory nerve was identified and protected . an anatomical radial locking plate ( synthes ltd . ,
paoli , pa , usa ) was inserted subcutaneously along the interval between the first and second compartments .
the radial styloid fragment was fixed with one or two locking screws , and the plate was secured with two screws through another incision proximally [ figure 3 ] . for intraarticular fractures involving the scaphoid or lunate fossa
, dorsal capsulotomy was performed through the same incision to allow direct visualization and facilitate restoration of articular congruity .
k - wire was used as a joystick to mobilize the articular fragment [ figure 4 ] . in cases with metaphyseal comminution
, injectable bone graft substitutes were used through an 11-gauge spinal needle to fill the osseous defect .
radiographs anteroposterior and lateral views of distal forearm and wrist taken 3 months after operation showing bicolumnar plate fixation for the distal radius , suture anchor fixation for the ulnar styloid , and osseous union peroperative arthroscopic views showing kirschner - wire was used as a joystick to mobilize the articular fragment .
all operations were performed by the single surgeon ( chen , ac - y ) . under general anesthesia , distal radius fractures were reduced and fixed temporarily by kirschner - wire ( k - wire ) after realignment was confirmed using a mini c - arm image intensifier .
two k - wires were used to secure the dorsal lunate facet fragment for correction of dorsal angulation .
a 1 cm skin incision was made distal to the fracture side along the intermediate column and was directly deepened to enter the fourth compartment .
the extensor tendons were then protected and retracted toward the ulna to explore the dorsal lunate fragment .
blunt dissection was performed using a freer elevator underneath the extensor tendons until it met the second incision proximal to the fracture site .
the extensor retinaculum was partially released in the distal half , and the dorsal locking plate ( synthes ltd . ,
paoli , pa , usa ) was inserted along the ulnar border of the distal radius . in most cases ,
the dorsal locking plate was precontoured at the distal end to allow caudocephalic placement of locking screws in the subchondral area of the distal fragment .
the radial sensory nerve was identified and protected . an anatomical radial locking plate ( synthes ltd . ,
paoli , pa , usa ) was inserted subcutaneously along the interval between the first and second compartments .
the radial styloid fragment was fixed with one or two locking screws , and the plate was secured with two screws through another incision proximally [ figure 3 ] . for intraarticular fractures involving the scaphoid or lunate fossa
, dorsal capsulotomy was performed through the same incision to allow direct visualization and facilitate restoration of articular congruity .
k - wire was used as a joystick to mobilize the articular fragment [ figure 4 ] . in cases with metaphyseal comminution
, injectable bone graft substitutes were used through an 11-gauge spinal needle to fill the osseous defect .
radiographs anteroposterior and lateral views of distal forearm and wrist taken 3 months after operation showing bicolumnar plate fixation for the distal radius , suture anchor fixation for the ulnar styloid , and osseous union peroperative arthroscopic views showing kirschner - wire was used as a joystick to mobilize the articular fragment .
the average final correction of deformity was 4.1 mm ( range 09 mm ) for rh , 7.6 ( range 018 ) for ri , and 20.7 ( range 539 ) for volar tilt ( vt ) [ table 2 ] .
no significant differences were found between postoperative and final rh , ri , and vt ( p > 0.05 ) .
the rom of the wrist compared to the other side at 1 year followup averaged 85% of extension , 75% of flexion , 83% of radial deviation , 85% of ulnar deviation , 93% of pronation , and 85% of supination [ table 3 ] .
grip strength measured using an electronic dynamometer ( tkk 5401 ; takei scientific instruments co. , ltd . ,
niigata , japan ) was restored to 83% ( range 65100% ) of the other hand at the final followup evaluation .
functional scores , according to the gartland and werley scoring system , were 3.7  3.6 ( range 012 ) ; there were 14 excellent , 7 good , and 3 fair results .
range of motion and grip strength three of 24 patients ( 13% ) had surgical complications : one was osseous and two were soft tissue related .
this occurred in an elderly and very osteoporotic patient of ao type c2 fracture with metaphyseal comminution .
progressive vt and loss of rh with loose proximal screws were noted after 3 months of followup .
this patient acquired osseous union with pain - free motion of the wrist at 6 months .
as for soft tissue complications , there were no wound infections or extensor tendon ruptures .
another patient asked us to remove the radial styloid locking plate because of an uncomfortable sensation when the patient played volleyball .
traditionally , the dorsal approach in the distal radius may have some shortcomings including wide dissection , excursion of tendons after rerouting ( especially the extensor pollicis longus ) , and tendon attrition caused by the dorsal implants.1516 a modified dorsal approach with separate incisions was designed to alleviate the above complications , and it proved to be an efficacious option for managing distal radius fractures with limited complications.17 in our series , good or excellent results were achieved in 21 of 24 patients . in the remaining three patients with fair results , one had proximal screw loosening and delayed union until 6 months .
the overall outcomes were comparable to those of other studies that used conventional open and mini - open procedures.61819 in a successful mipo surgery , the quality of indirect reduction and fixation stability should not be compromised by smaller skin incisions and less exposure .
we performed radiographic analysis in our series ; rh , ri , and vt were all perfect .
in addition , there were no significant differences between postoperative and 1-year radiographic parameters , confirming that fixation was adequately secured to maintain realignment until osseous healing.20 moreover , general concerns regarding soft tissue complication after dorsal plating in the distal radius could thus be lessened by minimizing tissue dissection through separate skin incisions .
although mipo techniques for distal radius fractures have also been successfully performed through a volar approach by preserving the pronator quadratus muscle,521 they may require either downsized implants or shifting to transverse skin incision distally to fit the minimal exposure involved in such techniques
. a recent study compared the traditional volar approach with a volar mipo approach.22 the clinical and radiographic results were not statistically different although patient 's satisfaction was higher and pain score was lower in the mipo group .
however , neurovascular complications were concerned with mipo through volar approach . whereas dorsal approach allows a direct and quick access to the distal radius . in index surgery , mipo techniques have been introduced through a modified dorsal approach using metal implants that are commonly used in conventional osteosynthesis procedures .
additional surgical procedures , for example , bone grafting or open reduction of articular fragment , can also be introduced through the same skin incision over the dorsal wrist when necessary.20 several limitations of this study were noted .
first , it is a retrospective study with relatively high number of patients ( six patients , 20% ) lost at the followup .
further prospective and larger outcome studies with direct comparison to other osteosynthesis techniques are necessary to better evaluate the long term effect and superior efficacy of the dorsal mipo technique .
the clinical results of a modified dorsal approach for distal radius fracture achieved in the current study were encouraging .
bicolumnar double plating could provide sufficiently secure fixation and yield a low rate of complications .
both functional survey and radiographic analysis confirmed that the index procedure is a feasible option for the management of dorsally unstable distal radius fractures and can result in favorable surgical outcomes .
no benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article .
no benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article .
 background : controversy still exists regarding the current treatment modalities for unstable distal radius fractures . 
 there are yet few articles investigating the efficacy of bicolumnar dorsal plating technique , which is designed to minimize tissue dissection while providing sufficiently secure fixation . 
 a clinical study was performed to evaluate the feasibility of the minimally invasive plate osteosynthesis ( mipo ) technique using a modified dorsal approach for the treatment of distal radius fractures.materials and methods : thirty patients with unilateral distal radius fracture who underwent bicolumnar plate fixation with a minimally invasive dorsal approach between september 2008 and december 2010 were included in this retrospective study . 
 twenty four patients ( 8 men and 16 women ) with a mean age of 53 years ( range 18 - 85 years ) were available for followup of at least 1 year or more were included in final study . 
 herein , we report the functional radiological outcomes of the study . there were three cases of ao type a fracture , five cases of ao type b fracture , and 16 cases of ao type c fracture.results:the union was achieved in all the patients . 
 the functional results at one - year followup , assessed using the modified gartland and werley scoring system , were excellent in 14 patients , good in seven patients , and fair in three patients . 
 the average correction of deformity was 4.1 mm for radial height , 7.6 for radial inclination , and 20.7 for volar tilt.conclusions:mipo with a dorsal approach is a feasible option for the management of displaced distal radius fractures and can result in favorable surgical outcomes . 
I
M
Operative procedure
R
D
C
Financial support and sponsorship
Conflicts of interest