Locking Versus Nonlocking Palmar Plate Fixation of Distal Radius Fractures

n Feature Article

SPOTLIGHT ON upper extremity Locking Versus Nonlocking Palmar Plate Fixation of Distal Radius Fractures

Michael Osti, MD; Christoph Mittler, MD; Richard Zinnecker, MD; Christoph Westreicher, MD; Clemens Allhoff, MD; Karl Peter Benedetto, MD

abstract Full article available online at Healio.com/Orthopedics. Search: 20121023-18

This study compared functional and radiological outcomes after treatment of extension- type distal radius fractures with conventional titanium nonlocking T-plates or titanium 1.5-mm locking plates. A total of 60 patients were included and followed for 4 to 7 years after receiving nonlocking T-plates (group A; n530) or locking plates (group B; n530) with and without dorsal bone grafting. Bone grafting was significantly more of- ten performed in the nonlocking group to increase dorsal fracture fixation and stability (P,.003). Pre- and postoperative and follow-up values for palmar tilt, radial inclination, radial shortening, and ulnar variance were recorded. Age, sex, and fracture type were similarly distributed between the 2 groups. Postoperative and follow-up evaluation revealed equal allocation of intra-articular step formation and osteoarthritic changes to both groups. The overall complication rate was 25%. Compared with the nonlocking system, patients undergoing locking plate fixation presented with statistically significantly better values for postoperative palmar tilt (5.53° vs 8.15°; P,.02) and radial inclination (22.13° vs 25.03°; P,.02). However, forearm pronation was significantly better in group A (P,.005). At follow-up, radial inclination tended to approach a statistically significant difference in favor of group B. All clinical assessment, including Mayo wrist score, Disabilities of the Arm, Shoulder, and Hand score, Green and O’Brien score, Gartland and Werley score, visual analog scale score, and grip strength, yielded no statistically significant difference between the 2 groups. Locking plates seem to provide benefits regarding surgical technique and comfort, improvement in implant anchorage (especially in osteoporotic bone), and reduce the necessity of additional bone grafting.

Drs Osti, Mittler, Zinnecker, Westreicher, Allhoff, and Benedetto are from the Department of Trauma Surgery and Sports Traumatology, Academic Hospital Feldkirch, Feldkirch, Austria. Drs Osti, Mittler, Zinnecker, Westreicher, Allhoff, and Benedetto have no relevant financial relation- ships to disclose. Correspondence should be addressed to: Michael Osti, MD, Department of Trauma Surgery and Sports Traumatology, Academic Hospital Feldkirch, Carinagasse 47, 6800 Feldkirch, Austria (michael. [email protected]). doi: 10.3928/01477447-20121023-18

NOVEMBER 2012 | Volume 35 • Number 11 e1613 n Feature Article

he purposes of surgical treatment radial shortening, ulnar variance, intra- to AO/ASIF classification, 12 fractures of displaced distal radius fractures articular step formation, and development were type A3, 6 were type C2, and 12 Tare restoration of anatomic align- of osteoarthritic transformation, were per- were type C3. Five patients presented ment and articular congruity, preservation formed postoperatively and at follow-up. with an average 2.8061.24-mm intra- of reduction, and achievement of the best For clinical wrist function assessment, articular step formation. Surgery was per- possible wrist. Many studies have report- the Mayo wrist score, Disability of the formed an average of 6.465.6 days after ed that palmar plate fixation is an effec- Arm, Shoulder, and Hand (DASH) score, trauma. Additional dorsal cancellous bone tive option for most types of distal radius Green and O’Brien score, and Gartland grafting was performed in 13 cases, which fractures.1-8 Using an interlocking fixation and Werley score were used. Follow-up is statistically significantly less frequent system results in good patient satisfac- examination also included an evaluation compared with group A (P,.003). Mean tion and wrist function and restoration of active range of motion, wrist pain ac- time of postoperative immobilization in a of physiological radius length and axis cording to the visual analog scale (VAS) splint cast was 31.969.2 days. Complete function.1-4,9-12 Several analyses could not 0-100), and grip power measurement us- osseous fracture consolidation was docu- reveal that locking compression plates ing a hydraulic dynamometer (Jamar, mented on plain radiographs an average of providing angular stability are superior Clifton, New Jersey). Mean follow-up 52.7625.8 days postoperatively. in terms of biomechanical performance time was 6.3760.62 years for group A The overall complication rate for both when compared with conventional non- and 4.8560.80 years for group B. groups was 25%. Impairment of the su- locking fixation systems.5,13 The clinical Demographical data and pre- and post- perficial branch of the radial nerve, which significance of these findings is unknown, operative variables were compared be- was caused by irritation by dorsal ap- and it remains unclear whether the favor- tween the 2 groups. Unpaired t test was proach for bone grafting or intraoperative able results of surgical treatment with used to compare quantitative data, and temporary fracture fixation with K-wires, palmar locking plates are implant related. 2-tailed Fisher’s exact test was used for resulted in dysesthesia, preferential at the The objective of this study was to evaluate categorical data. Statistical significance extensor side of the thumb, in 6 patients. and compare the functional and radiologi- was defined as aP value less than .05. Implant malposition compelled early cal results of both fixation strategies to as- implant removal in 4 patients, 3 patients sess differences in the outcomes of wrist Results developed complex regional pain syn- function and fracture reduction. Group A comprised 21 women and 9 drome, and 2 patients developed carpal men (18 right and 12 left wrists) with a canal syndrome. Materials and Methods mean age of 52.6617.3 years. According Functional results for both groups are The records of 60 patients undergo- to AO/ASIF classification, 2 fractures shown in Table 1. ing surgery for displaced, extension-type were type A2, 11 were type A3, 1 was In group A, 23 patients specified no distal radius fractures at the authors’ in- type B1, 3 were type C1, 4 were type C2, residual wrist pain. Average grip strength stitution between 2001 and 2004 were and 9 were type C3. Four patients pre- was 23.7610.9 kg, which is 87% of the retrospectively reviewed. Thirty patients sented with an average 1.8660.66-mm noninvolved side. Mayo wrist score was received a conventional palmar titanium intra-articular step formation. Surgery excellent in 10 (33%) patients, good in nonlocking T-plate (group A). After the was performed an average of 6.364.9 14 (47%), fair in 5 (17%), and poor in institution converted to using modern an- days after trauma. To support the un- 1 (3%). According to the Gartland and gular stable fixation systems, 30 patients stable metaphyseal area of comminu- Werley score, 13 (43%) patients achieved were treated with a 1.5-mm palmar tita- tion, additional cancellous bone grafting an excellent result, 16 (53%) a good re- nium locking plate from the first genera- was performed in 25 patients, which was sult, and 1 (3%) a fair result. tion of locking compression plates for the statistically significantly more frequent In group B, 22 patients specified no distal radius (group B). The mechanism of compared with group B (P,.003). Mean residual wrist pain. Average grip strength injury was a fall on a hyperextended palm time of postoperative immobilization in a was 23.6610.0 kg, which is 92% of the in all cases. All fractures were classified splint cast was 30.469.7 days. Complete noninvolved side. Mayo wrist score was by computed tomography scans and plain osseous fracture consolidation was docu- excellent in 13 (43%) patients, good in 9 radiographs according to Association for mented on plain radiographs an average of (30%), fair in 6 (20%), and poor in 2 (7%). Osteosynthesis/Association for the Study 58.2628.5 days postoperatively. According to the Gartland and Werley of Internal Fixation (AO/ASIF) clas- Group B comprised 21 women and 9 score, 17 (57%) patients achieved an ex- sification. Radiological measurements, men (16 right and 14 left wrists) with a cellent result, 9 (30%) a good result, 1 including palmar tilt, radial inclination, mean age of 52.0612.0 years. According (3%) a fair result, and 1 (3%) a poor result.

e1614 ORTHOPEDICS | Healio.com/Orthopedics Distal Radius Fractures | Osti et al

tients and averaged radial and ulnar abduction, and supination Table 1 1.260.76 mm. Mild on follow-up examination. Comparison of Functional Results preexisting osteo- VAS scores, grip strength, and all scoring arthritic changes systems showed no statistically signifi- Result Group A Group B were found in 2 pa- cant difference. Follow-up radiological ROM, % of contralateral side tients. On follow-up assessment revealed a similar distribution radiographs, intra- of palmar tilt, radial inclination, radial Wrist extension 89 88 articular steps av- shortening, and ulnar variance between Wrist flexion 87 89 eraged 2.0261.23 the groups. Pre- and postoperative and Radial abduction 89 83 mm in 5 patients. follow-up intra-articular step formation Ulnar abduction 85 90 Osteoarthritic and development of osteoarthritic changes Forearm rotation 97 95 changes were grad- were equally allocated to both groups. Mean scores ed mild in 7 patients Compared with patients receiving VAS 7.6616.0 5.2611.8 and moderate in 3 the nonlocking system, patients receiv- DASH 14.9617.6 9.9610.4 patients. ing locking plate fixation of the distal Green and O’Brien 87.7613.9 85.2620.1 In group B, radius presented with superior values postoperative intra- for postoperative palmar tilt and radial Mean grip strength, kg 23.7610.9 23.6610.0 articular step for- inclination that reached statistical sig- Abbreviations: DASH, Disabilities of the Arm, Shoulder, and Hand; ROM, range of motion; VAS, visual analog scale. mation was docu- nificance (P,.02). However, forearm mented in 7 pa- pronation was significantly better in tients and averaged group A (P5.005). At follow-up, radial 2.0161.38 mm. inclination tended to approach a statis- Table 2 Mild preexisting os- tically significant difference in favor of Radiological Results teoarthritic changes group B. were found in 2 pa- Result Group A Group B tients. On follow-up Discussion Mean preoperative radiographs, intra- Open reduction and palmar plate Palmar tilt, deg 215.27617.29 220.73623.74 articular steps av- fixation has been advocated for exten- Radial inclination, deg 16.6365.65 15.3266.38 eraged 2.5962.46 sion-type distal radius fractures.1-4,9-12,14 Radial shortening, mm 8.9563.49 7.9063.04 mm in 7 patients. Several biomechanical and clinical Ulnar variance, mm 2.7663.05 4.2863.06 Osteoarthritic studies have demonstrated that exter- changes were grad- nal fixation and closed reduction with Mean postoperative ed mild in 7 pa- percutaneous pin fixation should be re- Palmar tilt, deg 5.5363.48 8.1564.44 tients and moderate served for specific, complex, and prob- Radial inclination, deg 22.1364.78 25.0364.16 in 1 patient. lematic fracture patterns in selected Radial shortening, mm 12.1962.49 12.8862.74 Age, sex, frac- patients.6,15-18 Palmar plating yielded a Ulnar variance, mm 0.1561.89 -0.2161.23 ture type according favorable result compared with dorsally Mean loss of correction to AO/ASIF clas- applied fixation constructs.16,19 Reports Palmar tilt, deg 1.2562.21 0.5662.01 sification, involved are accumulating in the literature on the Radial inclination, deg 1.5563.34 0.6361.71 limb, handedness, clinical and radiological performance time to surgical in- of various palmar locking plates with Radial shortening, mm 0.3761.08 0.3161.39 tervention, time to broadly distributed qualities and subtle Ulnar variance, mm 0.6461.45 0.4860.86 fracture consolida- differences in specific implant charac- Abbreviation: deg, degrees. tion, and preopera- teristics.1-4,6,7,9-12,16 The multiplicity of tive palmar tilt, ra- reports in the literature and new im- dial inclination, ra- plant designs results in more options for Radiological results for both groups dial shortening, and ulnar variance values choosing an appropriate treatment strat- are shown in Table 2. were similarly distributed between the 2 egy and, therefore, hints at an increased In group A, postoperative intra-articular groups. No statistically significant differ- autonomy and potential for creativity step formation was documented in 5 pa- ence existed regarding flexion, extension, in individual surgeons. Personal prefer-

NOVEMBER 2012 | Volume 35 • Number 11 e1615 n Feature Article

ence and experience should influence struction and maintenance of reduction References these considerations. and leads to good mid-term functional 1. Arora R, Lutz M, Fritz D, Zimmermann R, The current study adds 60 patients results. The current data suggest that Oberladstätter J, Gabl M. Palmar locking plate for treatment of unstable dorsal dis- with good and excellent functional re- functional and radiological outcomes do located distal radius fractures. Arch Orthop sults and acceptable radiological out- not seem to be implant-related factors. Trauma Surg. 2005; 125(6):399-404. comes to the existing literature, which This supports the findings of Gondusky 2. Figl M, Weninger P, Liska M, Hofbauer M, may be considered an argument for the et al5 and Hart et al,8 who reported no Leixnering M. Volar fixed-angle plate osteosynthesis of unstable distal radius fractures: operative reconstruction of distal ra- differences between dorsal and palmar 12 months results. Arch Orthop Trauma Surg. dius fractures via a palmar approach. locking and nonlocking plate fixation in 2009; 129(5):661-669. This study’s functional and radiological terms of biomechanical performance in 3. Gruber G, Bernhardt GA, Köhler G, Gruber K. Surgical treatment of distal radius frac- outcomes are comparable with those in a extension-type fracture model with a tures with an angle fixed bar palmar plating previous reports.1,3,4,9,11 Choice of plat- dorsal metaphyseal bone defect. system: a single centre study of 102 patients ing system version may be a decision of Biomechanical analyses have rec- over a 2-year period. Arch Orthop Trauma Surg. 2006; 126(10):680-685. lower ranking. Technical advantages, im- ommended an immediate functional 4. Lattmann T, Meier C, Dietrich M, Forberger provements in implant anchorage, facili- postoperative rehabilitation protocol be- J, Platz A. Results of volar locking plate tation of implant handling, including a cause fragment displacement is likely to osteosynthesis for distal radius fractures. J technically simplified maneuver for frac- occur in the early postoperative period.9 Trauma. 2011; 70(6):1510-1518. ture reduction, and advances in fracture The mid-term functional results of the 5. Gondusky JS, Carney J, Erpenbach J, et al. Biomechanical comparison of locking ver- treatment of osteoporotic bone are recent current study are positive, despite the sus nonlocking volar and dorsal T-plates developments in modern implant design. expanded postoperative immobilization for fixation of dorsally comminuted distal radius fractures. J Orthop Trauma. 2011; However, the current study’s results in- period of approximately 30 days in both 25(1):44-50. dicate that neither functional nor radio- groups. 6. Schmelzer-Schmied N, Wieloch P, Martini logical results correlate with locking or This study had some limitations, in- AK, Daecke W. Comparison of external nonlocking palmar plate fixation. cluding the relatively small number of fixation, locking and non-locking palmar plating for unstable distal radius fractures Follow-up examination revealed that a patients included in each study group in the elderly. Int Orthop. 2009; 33(3):773- significantly better reconstruction of pal- (leading to a relatively high beta level 778. mar tilt and radial inclination could not and low statistical power for some vari- 7. Wong TC, Yeung CC, Chiu Y, Yeung SH, Ip be maintained with locking plates, when ables), the retrospective approach to an FK. Palmar fixation of dorsally displaced distal radius fractures using locking plates with both values aligned with those measured approximate speculation, and the fact Smartlock locking screws. J Hand Surg Eur for nonlocking plates. Forearm pronation that the interlocking fixation system Vol. 2009; 34(2):173-178. was better in group A. A slight tendency used descended from a first-generation 8. Hart AJ, Seepaul T, Hewitt RJ, Ang S, toward statistical significance was de- locking compression plate for the distal Hansen U, Amis AA. The palmar locking compression plate is biomechanically tected for radial inclination on follow- radius. Operative treatment of distal ra- comparable to the dorsal PI Plate for dor- up radiographs in group B. The neces- dius fractures has increased over the past sally comminuted, intraarticular wrist fractures. J Hand Surg Eur Vol. 2007; sity of bone grafting for dorsal fracture decade with the development of im- 32(4):388-393. comminution decreased significantly plants, resulting in a less frequent indi- 9. Arora R, Lutz M, Hennerbichler A, with the application of locking fixation. cation for surgical stabilization in the Krappinger D, Espen D, Gabl M. The statistically significantly higher use early study period. Although AO/ASIF Complications following internal fixation of unstable distal radius fracture with pal- of dorsal bone grafts in the nonlocking fracture types were evenly distributed in mar locking-plate. J Orthop Trauma. 2007; group contributed to fracture fixation and both groups, fewer patients may have 21(5):316-322. stability, which explains the comparable been regarded as suitable candidates for 10. Beharrie AW, Beredjiklian PK, Bozentka functional and radiological results be- surgery during that time. Nevertheless, DJ. Functional outcomes after open reduction and internal fixation for treatment of tween the 2 groups. Thus, the nonlocking the authors believe that the study data displaced distal radius fractures in patients plate design and the dorsal bone graft are add valuable information to the existing over 60 years of age. J Orthop Trauma. 2004; 18(10):680-686. responsible for the similar patients out- knowledge of implant selection, a sur- 11. Konstantinidis L, Helwig P, Strohm PC, come. Morbidity of the graft donor and geon’s autonomy in the determination of Hirschmüller A, Kron P, Südkamp NP. receptor sites and operative time can be the plating system, and the excellent Clinical and radiological outcomes after reduced with the use of locking plates. functional and radiological results ob- stabilisation of complex intra-articular fractures of the distal radius with the 2.4 mm Locking and nonlocking palmar tainable by palmar plate fixation in distal LCP. Arch Orthop Trauma Surg. 2010; plates are successful in anatomy recon- radius fractures. 130(6):751-757.

e1616 ORTHOPEDICS | Healio.com/Orthopedics Distal Radius Fractures | Osti et al

12. Stevenson I, Carnegie CA, Christie EM, 15. Gangopadhyay S, Ravi K, Packer G. Dorsal ing fixation using mixed pins or a palmar Kumar K, Johnstone AJ. Displaced distal plating of unstable distal radius fractures fixed-angle plate.J Hand Surg Eur Vol. 2010; radius fractures treated using volar locking using a bio-absorbable plating system and 35(8):646-651. J J Hand Surg Eur Vol plates: maintenance of normal anatomy. bone substitute. . 2006; 18. Westphal T, Piatek S, Schubert S, Winckler S. Trauma . 2009; 67(3):612-616. 31(1):93-100. Outcome after surgery of distal radius frac- 13. Trease C, McIlf T, Toby EB. Locking versus 16. Letsch R, Infanger M, Schmidt J, Kock tures: no differences between external fixa- non-locking T-plates for dorsal and volar fix- HJ. Surgical treatment of fractures of the tion and ORIF. Arch Orthop Trauma Surg. ation of dorsally displaced distal radius frac- distal radius with plates: a comparison 2005; 125(8):507-514. J Hand Surg Arch tures: a biomechanical study. of palmar and dorsal plate position. 19. Jakubietz RG, Gruenert JG, Kloss DF, Am Orthop Trauma Surg . 2005; 30(4):756-763. . 2003; 123(7):333- Schindele S, Jakubietz MG. A randomised 14. Hakimi M, Jungbluth P, Windolf J, Wild M. 339. clinical study comparing palmar and dorsal Functional results and complications follow- 17. Marcheix PS, Dotzis A, Benkö PE, Siegler fixed-angle plates for the internal fixation ing locking palmar plating on the distal ra- J, Arnaud JP, Charissoux JL. Extension frac- of AO C-Type fractures of the distal radius dius: a retrospective study. J Hand Surg Eur tures of the distal radius in patients older than in the elderly. J Hand Surg Eur Vol. 2008; Vol. 2010; 35(4):283-288. 50: a prospective randomized study compar- 33(5):600-604.

NOVEMBER 2012 | Volume 35 • Number 11 e1617