Treatment of distal radius fractures with palmar plates and locking screws. Comparisson of two different types of plate.

Various plating systems are available to fix distal radius fractures, each with a specific design. The purpose of this study was to compare radiological outcome and complications of the Variable Angle LCP Plate 2.4-mm (DePuy Synthes) with the VariAx volar locking plate (Stryker). One hundred patients (103 wrists) operated on for a distal radius fracture were retrospectively reviewed with a mean follow-up of 3.5 years. Seventy-three wrists were treated with a DePuy Synthes plate and 30 with a VariAx plate. The overall complication rate was 32%. Nineteen cases underwent revision surgery, 18 had malunion and 3 complex regional pain syndrome. Complicaton rate was 43% with DePuy Synthes plates and 27% with Variax plates, but the difference was not significant.

Hook versus locking plate fixation for Neer type-II and type-V distal clavicle fractures: a retrospective cohort study.

PURPOSE: This study examined the outcomes and complications after treatment of unstable distal clavicle fractures with hook or locking plate fixation. METHODS: A retrospective search was performed of all acute distal clavicle fractures treated with open reduction and internal fixation from 2009 to 2019 at a Level I trauma center. Patients were separated into hook and locking plate fixation groups. Rates of union, complications, and reoperation, were extracted. QuickDASH (Disabilities of Arm, Shoulder, and Hand) scores were determined. RESULTS: Thirty-one patients met the inclusion criteria and were included in the study. Of these, 12 patients were treated with hook plates and 19 were treated with locking plates. All fractures healed without loss of reduction, regardless of implant selection. There were no immediate or long-term complications in either group. 83% of hook plate patients underwent planned implant removal, while 37% of locking plate patients requested implant removal secondary to irritation. QuickDASH scores were comparable and excellent in both groups. CONCLUSIONS: Hook and locking plate fixation for Neer type-II and type-V distal clavicle fractures have comparably high rates of union. Hook plates were removed routinely per protocol, while locking plates were removed only if symptomatic and occurred significantly less often.

Evaluation of callus formation in distal femur fractures after carbon fiber composite versus stainless steel plate fixation.

INTRODUCTION: Carbon-fiber-reinforced polyetheretherketone (CFR) composite plates have a more favorable stress modulus than stainless steel (SS) plates that may confer an advantage to bridge plating. The purpose of this study was to compare callus formation after CFR and SS plating of distal femur fractures. METHODS: A retrospective review identified distal femoral fractures treated with CFR (n = 10) and SS (n = 21) plate fixation. Callus formation was measured using the modified Radiographic Union Score for Tibia (mRUST) at 3- and 6-month follow-up by three orthopedic trauma surgeons. Loss of alignment, implant failure, and revision surgeries were reviewed. RESULTS: At 3 months, the mRUST in the CFR and SS groups was 9.0 (range, 6.3-12.3) and 6.9 (range, 4.3-11.7), respectively (p = 0.01). At 6 months, the mRUST in the CFR and SS groups was 11.4 (range, 7.7-16.0) and 10.5 (range, 6.0-15.7), respectively (p = 0.3). CFR and SS groups had a loss of fracture alignment in 1 (10%) and 1 (5%) patient, respectively (p = 0.5), and an unplanned revision surgery in 0 (0%) and 3 (15%) patients, respectively (p = 0.2). All three revisions surgeries in the SS group were for nonunion repair. CONCLUSIONS: Treatment of distal femur fractures with CFR versus SS plating resulted in greater callus formation at 3 months. At 6 months, there was no difference in callus formation between groups. A larger series of patients is necessary to determine if the observed early increased callus formation confers a benefit to clinical outcomes. LEVEL OF EVIDENCE: Therapeutic level III.

Ex Vivo Biomechanical Comparison of Titanium Locking Plate, Stainless Steel Nonlocking Plate, and Tie-in External Fixator Applied by a Dorsal Approach on Ostectomized Humeri of Pigeons (Columba livia).

To compare the bending strength of a locking plate (LP), nonlocking plate (NLP), and an external skeletal fixator intramedullary pin (ESF-IM) tie-in fixation applied by a dorsal approach in an avian humerus fracture model, 5 left humeri obtained from pigeon (Columba livia) cadavers were randomly assigned to each repair technique (n = 15). The ESF-IM group was repaired with a 0.062-inch intramedullary pin tied-in with two 0.035-inch positive profile transfixation pins using acrylic filled plastic tubing. The LP group was repaired with a dorsally applied titanium 1.6-mm screw 7-hole locking plate (1 bicortical and 2 monocortical screws in each segment). The NLP group was repaired with a dorsally applied 6-hole stainless steel 1.5-mm dynamic compression plate (all bicortical screws). All constructs were applied before complete ostectomy to allow perfect reconstruction. Constructs were cyclically tested nondestructively for 1000 cycles in four-point bending before being tested to failure. Outcome measures included stiffness, strength, and strain energy. All specimens cycled without failure. The ESF-IM specimens were significantly stiffer and stronger than the plated repair groups. Plated constructs had significantly higher strain energies than ESF-IM. LP and NLP were of equal stiffness, strength, and strain energies. This study demonstrated that bending biomechanical properties of the ESF-IM configuration were superior to those of the dorsal plate fixation. Exact properties of fixation required to facilitate avian fracture healing are largely unknown. Further study, including assessments of optimal plate position and configuration, and torsional and in vivo studies in avian species are warranted.

Repair of a Tibiotarsal Fracture in a Pomeranian Goose ( Anser anser) With a Locking Plate.

A 2-year-old Pomeranian goose ( Anser anser) weighing 8.1 kg was examined because of non-weight-bearing lameness of the right limb. A closed, transverse, diaphyseal fracture of the distal third of the right tibiotarsus with a craniolateral displacement of the distal fragment was diagnosed radiographically. Surgery under general anesthesia was performed to repair the fracture with a 14-hole, 2.7-mm locking plate fixed with 6 screws in a bicortical manner. Two days later, the bird was fully weight-bearing on the leg. Radiographs performed 4 and 8 weeks after surgery showed good healing of the affected bone with an appropriate callus formation bridging the fracture line. Sixteen weeks after surgery, the patient was readmitted because of lameness exhibited while staying outside exposed to subzero (°C) temperatures. On the basis of this finding, heat conduction was postulated as the possible cause of lameness because it disappeared after implant removal. To the best our knowledge, this case represents the first report of a surgical repair of a tibiotarsal fracture with a locking plate in waterfowl.

Distal radius plate of CFR-PEEK has minimal effect compared to titanium plates on bone parameters in high-resolution peripheral quantitative computed tomography: a pilot study.

BACKGROUND: Carbon-fiber-reinforced poly-ether-ether-ketone (CFR-PEEK) has superior radiolucency compared to other orthopedic implant materials, e.g. titanium or stainless steel, thus allowing metal-artifact-free postoperative monitoring by computed tomography (CT). Recently, high-resolution peripheral quantitative CT (HRpQCT) proved to be a promising technique to monitor the recovery of volumetric bone mineral density (vBMD), micro-architecture and biomechanical parameters in stable conservatively treated distal radius fractures. When using HRpQCT to monitor unstable distal radius fractures that require volar distal radius plating for fixation, radiolucent CFR-PEEK plates may be a better alternative to currently used titanium plates to allow for reliable assessment. In this pilot study, we assessed the effect of a volar distal radius plate made from CFR-PEEK on bone parameters obtained from HRpQCT in comparison to two titanium plates. METHODS: Plates were instrumented in separate cadaveric human fore-arms (n = 3). After instrumentation and after removal of the plates duplicate HRpQCT scans were made of the region covered by the plate. HRpQCT images were visually checked for artifacts. vBMD, micro-architectural and biomechanical parameters were calculated, and compared between the uninstrumented and instrumented radii. RESULTS: No visible image artifacts were observed in the CFR-PEEK plate instrumented radius, and errors in bone parameters ranged from -3.2 to 2.6%. In the radii instrumented with the titanium plates, severe image artifacts were observed and errors in bone parameters ranged between -30.2 and 67.0%. CONCLUSIONS: We recommend using CFR-PEEK plates in longitudinal in vivo studies that monitor the healing process of unstable distal radius fractures treated operatively by plating or bone graft ingrowth.

[One-stage bone grafting combined with non-contact plate technique for treatment of post-traumatic femoral osteomyelitis and bone defects].

Eight patients with femoral osteomyelitis were admitted in Lanzhou General Hospital of PLA between July 2012 and July 2015. During the operation the femur was fixed with non-contact locking plate after thorough debridement. Iliac morselized cancellous bones without cortical bone were filled in the bone defect after debridement. The locking plates were placed in the lateral subcutaneous interface superficial to the vastus lateralis muscle. Drainage tubes were routinely placed postoperatively. The surgery was completed successfully in all patients, and the average operation time was (130±10) min (120-150 min). Intravenous antibiotics were administrated for 2 weeks and followed by 4 week-oral antibiotics after the operation in all 8 cases. Drainage tubes remained in situ about 8 days. All patients were followed up for 12-48 months, with an average of (19±7) months. Postoperative X-ray examination showed bone union in 7 cases with an average healing time of (16±5) weeks. One patient failed with relapsed infection, and was later treated with Ilizarov apparatus after secondary debridement. No plate and screw fracture, loose and fixation failure were observed in all 8 cases.

Biomechanical comparison of two angular stable plate constructions for periprosthetic femur fracture fixation.

PURPOSE: Fractures of the femur associated with total hip arthroplasty are a significant concern in orthopaedic and trauma surgery. However, little is known about the different biomechanical properties of internal fixation systems in combination with periprosthetic fractures. In this study two new internal fixation systems for periprosthetic fractures are investigated using a cadaver fracture model simulating a Vancouver B1 periprosthetic femur fracture. METHODS: Nine pairs of fresh-frozen cadaver femurs were scanned by dual X-ray absorptiometry. Cementless total hip prostheses were implanted and a periprosthetic femur fracture was simulated. Fractures were randomly fixed either with the fixed angle locking attachment plate (LAP®, Depuy Synthes®, Solothurn, Switzerland) or the variable angle non-contact bridging plate (NCB®, Zimmer GmbH, Winterthur, Switzerland). Each construct was cyclically loaded to failure in axial compression. RESULTS: Axial stiffness and cycles to failure were significantly higher in the NCB group. Both systems were able to be fixed well around the femoral stem. CONCLUSION: The two different internal fixation systems for periprosthetic fractures differed significantly in our setup. The non-contact bridging plate system revealed significantly higher failure load and may be the preferred option where high stability and load capacity is needed right after operation.

Locking versus non-locking neutralization plates for treatment of lateral malleolar fractures: a randomized controlled trial.

PURPOSE: The reduction of periosteal compression through the use of a locking plate may minimize disturbances of bone blood supply and may improve the rate of bone union. A single-centre, assessor blinded randomized controlled trial was conducted to compare the clinical effectiveness of a locking plate and a non-locking plate. METHODS: A total of 52 patients with AO/OTA 44B lateral malleolar fractures were included in this study. All patients underwent surgical fixation using a lag screw and neutralization plate. An identical treatment protocol was used in all patients, with exception of plate selection. The rate of radiographic bone union, defined as the complete disappearance of fracture lines confirmed through anteroposterior, lateral, and internal oblique views was compared at three, six, and 12 months following surgery. In addition, the Medical Outcomes 36-Item Short-Form Health Survey (SF-36) score, the time required for resolution of tenderness at the fracture site and the complication rate were evaluated. RESULTS: Twenty-three patients were randomly assigned to undergo fixation using a locking plate, and 29 patients were assigned to undergo fixation using a non-locking plate. Intention-to-treat analysis showed no difference in the radiographic bone union rate of fibula, SF-36 score, the time for resolution of tenderness at the fracture site and complication rates. CONCLUSION: No differences were observed in patients with AO/OTA 44B lateral malleolar fractures undergoing fixation with a locking versus non-locking neutralization plate.

Tibial fracture treated by minimally invasive plating using a novel low-cost, high-technique system.

PURPOSE: The less invasive stabilization system (LISS) can effectively treat tibial fractures. However, the LISS is technically demanding, has a long learning curve, and presents a heavy economic burden to patients. The U-grooved locking compression plate (U-LCP), characterized by a U-groove at each end, is designed to treat tibial fractures. This paper reports the outcomes of tibial fractures treated using the U-LCP compared with the LISS. METHODS: Seventy-eight patients with unilateral tibial fractures treated with either the U-LCP (group I) or LISS (group II) were enrolled. In group I, a U-LCP was inserted subcutaneously with two Kirschner wires embedded into the U-grooves to temporarily secure the plate. A second identical plate was placed over the first to guide screw insertion. In group II, the LISS was used to fix the tibial fractures. Patient age, sex, fracture type, severity of soft tissue injury, operative time, fluoroscopic time, complications, and functional recovery of affected limbs were recorded. RESULTS: The two groups were comparable in age, sex, fracture type, and severity of soft tissue injury (p > 0.05). The average operation and fluoroscopic times in group I were significantly less than those in group II (p < 0.05). At follow-up, all fractures healed. There were no significant differences between both groups in time to bony union, wound complication rate, or functional recovery of injured limbs (p > 0.05). CONCLUSIONS: The U-LCP can yield good outcomes in the treatment of proximal tibial fractures, with less radiation exposure, a shorter operation time, and a sustainable price compared with the LISS.

[Volar plate fixation of distal radius fractures]. / Radius alt uç kiriklarinda volar plak ile tedavi uygulamalari.

BACKGROUND: We aimed to evaluate the results of volar locking and unlocking plate fixation of adult distal radius fractures. METHODS: Thirty-four patients (14 female, 20 male, mean age: 48.5 +/- 17.9 years) who were treated for distal radius fractures were investigated retrospectively. The fractures were distributed as follows: 17.6% AO type B3, 11.8% AO type C2 and 70.6% AO type C3. The patients were evaluated clinically (Gartland and Werley score, visual analog scale (VAS), Disabilities of the Arm, Shoulder and Hand (DASH) score) and radiographically (Stewart score). RESULTS: The mean follow-up of patients was 24 +/- 16.3 months. According to the Gartland-Werley score, the results were excellent in 24.9%, good in 55.9%, moderate in 11.8% and poor in 2.9% of the patients. The mean VAS score was 0.5 +/- 1.1, and the mean DASH score was 26.1. According to the Stewart criteria, 44.1% of the patients were rated as excellent, 52.9% as good and 2.9% as moderate. Two patients had complex regional pain syndrome, one patient carpal tunnel syndrome and one patient tenosynovitis. CONCLUSION: Volar plate fixation is a good and effective treatment for distal radius fractures. The plate should be inserted properly and physiotherapy should not be ignored.

Effects of Bone-Plate Material on the Predicted Stresses in the Tibial Shaft Comminuted Fractures: A Finite Element Analysis.

PURPOSE: In this research, low modulus carbon fiber (CF)-reinforced polyetheretherketone composite plates (CF-PEEK plates) were compared with traditional metal plates using finite element analysis to establish a reference for clinical application. MATERIAL AND METHODS: Plates of stainless steel, titanium alloy (Ti6Al4V), or CF-PEEK with different carbon fiber reinforcement ratios (CF30, CF50, and CF60) were used to fix the tibial shaft comminuted fracture. The maximum stress, the maximum displacement of fracture and the stress shielding of cortex bone were analyzed. RESULTS: Under 200 N axial compression, the maximum displacement was measured in the CF30 plate (4.62 mm) and the minimum in the stainless steel plate (0.23 mm). The stress shielding rates of stainless steel, titanium, CF30, CF50, and CF60 plates were 59.4%, 54.4%, 23.75%, 48.75% and 66.25%. Under 700 N axial compression, the internal fixation by the CF30 plate failed. Among the other 4 plates, the maximum displacement was measured in the CF50 plate (2.52 mm) and the minimum in the stainless steel plate (0.78 mm). The stress shielding rate of plates made of stainless steel, titanium, CF50, and CF60 were 57.1%, 52.0%, 48.1%, and 67.8%. CONCLUSIONS: CF50 plates can be safely used in the tibial shaft comminuted fracture. The micromotion in the CF50 and CF60 plate was more beneficial to callus formation and fracture healing. The stress shielding of the cortex bone under the CF50 plate was the lowest. The finite element analysis indicated that the CF-PEEK material is worthy of further study because of its biomechanical advantages.

Biomechanical evaluation of locking versus nonlocking 2.0-mm malleable L-miniplate fixation of simulated caudal mandibular fractures in cats.

OBJECTIVE: To evaluate the biomechanical properties of the mandibles of cats with experimentally created osteotomies simulating oblique ramus fractures, which were stabilized with malleable L-miniplates with either locking screws [locking construct (LC)] or nonlocking screws [nonlocking construct (NLC)], compared with those for intact mandibles. SAMPLES: 20 mandibles from 10 adult cat cadavers. PROCEDURES: A block study design was adopted to allocate the mandibles of each cadaver to 2 of the 3 test groups (LC, NLC, or intact mandible). Mandibles within each cadaver were allocated systematically to a test group. For mandibles assigned to an LC and an NLC, a complete oblique osteotomy was performed from the mid rostral aspect of the ramus in a caudoventral direction. All mandibles were loaded in a single-load-to-failure test through cantilever bending. Load and actuator displacement were recorded simultaneously. Mode of failure and radiographic evidence of damage to tooth roots and the mandibular canal were evaluated. Biomechanical properties were compared among the groups. RESULTS: No iatrogenic tooth root damage was evident, but all mandibles with an LC and an NLC had evidence of screw invasion into the mandibular canal. Plated mandibles had significantly less stiffness and bending moment than intact mandibles. Stiffness was not significantly different between the LC and the NLC; the NLC had a greater bending moment at failure than the LC. The pre-yield stiffness of plated mandibles decreased when the number of screw holes overlapping the mandibular canal increased. CLINICAL RELEVANCE: The use of a malleable L-miniplate in a caudal mandibular fracture model is feasible. Both the LC and the NLC were inferior mechanically to intact mandibles. Type of construct used did not affect the construct stiffness significantly in tested mandibles.

A retrospective study of tibial plateau translation following tibial plateau levelling osteotomy stabilisation using three different plate types.

OBJECTIVE: To retrospectively evaluate mediolateral translation of the proximal tibial segment (tibial plateau) after tibial plateau levelling osteotomy (TPLO), stabilised with three types of plate. METHOD: Pre- and postoperative radiographs of 79 dogs that had TPLO surgery using three different types of plates were reviewed. Two plate types incorporated non-locking screws: Slocum (22 cases) and Orthomed Delta (33 cases) plates. The third plate type incorporated locking screws: Synthes TPLO Locking Compression Plate (LCP) (24 cases). The radiographs were viewed by three Diplomate surgeons who were blinded to the type of implant used. Medial or lateral translation of the proximal tibial plateau relative to the tibial diaphysis was assessed and measured at the lateral tibial cortex at the osteotomy site. RESULTS: Mean lateral translation of the tibial plateau was significantly greater when using the Synthes TPLO LCP with locking screws (+2.1 mm) compared to the non-locking Slocum (+0.4 mm) or Orthomed Delta (0.0 mm) plates. CLINICAL SIGNIFICANCE: The use of the Synthes TPLO LCP will maintain a malalignment of the tibial plateau. Accurate alignment of the tibial plateau must be ensured prior to application of the Synthes TPLO LCP.

[Pancarpal arthrodesis using a "CastLess Plate" in dogs and cats]. / Pankarpale Arthrodese unter Verwendung einer "CastLess Plate" bei Hunden und Katzen.

OBJECTIVE: Description of clinical experience with a new implant for dorsal plating in pancarpal arthrodesis. MATERIAL UND METHODS: Retrospective analysis (June 2008 - May 2009) of clinical records from a heterogenous group of dogs and cats which where treated by pancarpal arthrodesis using a PCA-plate ("CastLess-plate", Orthomed®, UK). RESULTS: In 15 dogs and three cats, a total of 20 pancarpal arthrodesis (complete fusion of carpal joints) using a PCA-plate were performed. External coaptation by cast was not used in the postoperative period. In two out of 17 arthrodesis in 15 dogs serious postoperative complications (plate deformation, wound infection) occurred which required a revision surgery. Fistula formation (8-16 weeks post surgery) was seen in six arthrodesis. They all resolved after medical therapy. In cats, all three arthrodesis showed postoperative complications (bone resorption under the plate n=1, paw swelling n=2). Long-term evaluation by telephone interview with the owners (17 owners, 6-21 months after surgery, one case lost in follow-up) revealed good or very good results for 17 of 19 arthrodesis. CLINICAL RELEVANCE: Pancarpal arthrodesis in dogs can be performed successfully using the "CastLess Plate" without additional external coaptation. Due to the size of the available implants complications have to be expected in cats.

The comparison of single plate and double plate fixation methods for treatment of humeral shaft nonunions.

OBJECTIVES: This study aims to evaluate the early- and mid-term shoulder and elbow functions and compare the union rates after the application of single plate and double plate for the treatment of humerus shaft nonunions. PATIENTS AND METHODS: This retrospective study included 56 patients (36 males, 20 females; mean age 53.8±9.5; range, 28 to 68 years) treated with double plate (n=25) and single plate (n=31) osteosynthesis between October 2012 and January 2016. Surgical treatment of the nonunion was applied in the fourth month after the fracture at the earliest. Autograft taken from the iliac bone was applied during the surgery in all patients. Evaluation was performed using The University of California at Los Angeles (UCLA) Shoulder Score, Mayo Elbow Performance Score (MEPS), Visual Analog Scale (VAS), Constant Shoulder Score, and Disabilities of the Arm Shoulder and Hand (DASH) questionnaire. RESULTS: The mean postoperative follow-up time was 40.7±9.6 (range, 25 to 58) months. No statistically significant difference was determined in respect of time to union, follow-up time, DASH questionnaire score, UCLA Shoulder Score, VAS, MEPS and Constant Shoulder Score after union in the comparison of the two groups (p>0.05). In the examination of postoperative early (three months) recovery phase of shoulder and elbow functions, statistically significant superior scores were obtained in the double plate group for MEPS (double plate median=85 [min 75-max 90], single plate median=75 [min 70-max 85]) and Constant Shoulder Score (double plate median=89 [min 85-max 92], single plate median=81 [min 75-max 90]) (p<0.001). CONCLUSION: There was no statistically significant difference in terms of time to union and union rates between single plate and double plate fixations for surgical treatment of humeral shaft nonunions. However, superior clinical results were obtained in the early recovery phase of shoulder and elbow functions with double plate fixation.

Arthrodesis of the equine proximal interphalangeal joint: a biomechanical comparison of 2 different LCP systems.

OBJECTIVE: This study compares the mechanical stability and surgical usability of 2 locking plate systems (Kyon ALPS-20 and Synthes PIP-LCP system) for arthrodesis of the equine proximal interphalangeal joint (PIJ). MATERIAL AND METHODS: The experimental ex vivo study included 6 pairs of cadaver distal limbs (n = 12). All specimens were derived from Warmblood horses of various ages that were euthanized for non-orthopedic reasons. Of the 12 limbs collected, 3 left and 3 right distal limb specimens were randomly assigned to each system for implantation. Two abaxial 4.5-mm cortical screws were inserted transarticularly in all cases. Both systems were implanted according to the manufacturer's instructions with the plates placed centrally between the 2 transarticular screws. The ALPS-20 systems were implanted using Kyon B-6.4-mm monocortical locking screws in all positions. The LCP systems were implanted axially using 2 Synthes 5-mm locking screws in the proximal and distal positions, with a standard 4.5-mm cortical screw inserted in the middle position. All constructs underwent CT-scans after implantation and biomechanical testing to detect implant deformation. Uniaxial mechanical loading was applied via a servo-hydraulic test system at a test speed of 50 mm/s, up to a maximum displacement of 80 mm. The resulting load-displacement curves were used to calculate yield point, stiffness, and maximum force for each construct. The measured values were evaluated for statistical significance (p < 0.05) between the 2 plate systems via one-factor ANOVA (Tukey test). The statistical power was verified for yield force, stiffness, and maximum load. RESULTS: No statistically significant differences between the 2 preparation groups were calculated across all of the measured parameters (p > 0.05). The ALPS system implants showed no signs of deformation, either in the plates or the screws. In contrast, the LCP demonstrated visible deformation, which had already occurred at the time of implantation from the tightening of the middle screw, as well as during the subsequent testing of the implants. After biomechanical testing, deformations ranging between 3.1° and 7.0° were measured in 4 LCPs. A total implant failure was observed for 2 LCPs. CONCLUSION AND CLINICAL RELEVANCE: Both systems demonstrated comparable mechanical properties in the present study's ex vivo test model for equine PIJ arthrodesis. As such, the Kyon ALPS-20 may be a good alternative to the Synthes LCP for equine PIJ arthrodesis.

Comparison of implant failure rates of different plates for midshaft clavicular fractures based on fracture classifications.

BACKGROUNDS: The aim of our study was to investigate failure rates of reconstruction plate and non-reconstruction plate, and find the best strategy for implant selection for different fracture types for midshaft clavicular fractures. PATIENTS AND METHODS: Two hundred twenty-six consecutive patients with midshaft clavicular fractures who received open reduction and plate fixation during Jan 2012 to July 2017 were reviewed. The correlations between implant failure rates and risk factors including demographic data, fracture classifications, and implant types were analyzed. RESULTS: AO/OTA fracture classification and plate types are the most important factors affecting implant failure for midshaft clavicular fractures. Reconstruction plate had a significantly higher failure rate (53%) than that of non-reconstruction plates (3%) in comminuted midshaft clavicular (AO/OTA 15-2C) fractures (P value < 0.01). However, the difference was not significant in AO/OTA 15-2A and 2B classifications. CONCLUSION: Patients with comminuted midshaft clavicular (AO/OTA 15-2C) fractures treated with reconstruction plates had very high implant failure rates compared to non-reconstruction plates. We suggested that patients with comminuted midshaft clavicular (AO/OTA 15-2C) fractures treated with reconstruction plates need more protection and more frequent follow-up in the postoperative period.

Mechanical aspects of a multidirectional, angular stable osteosynthesis system and comparison with four conventional systems.

BACKGROUND: Following open reduction, internal fixation of fractures of the mandible is predominantly achieved using plates and screws. Today, a multitude of osteosynthesis systems are available on the market. One therapy modality, primarily developed for orthopaedic surgery, is using angular stable osteosynthesis plate systems. The dominating principle of these is the bond between screw and plate following insertion. This principle of an "internal fixateur" results in a more stable fixation of the fragments associated with less compression of the bone surfaces. MATERIAL: A new multidirectional osteosynthesis system (TiFix=Smartlock, Hamburg - Germany) was modified to fit the maxillofacial region and compared with four other well established osteosynthesis systems developed by Mondial, Medicon, Synthes, Leibinger-Stryker, one of these (Unilock by Synthes) being also angular stable. The resistance to deformation in varying directions was investigated following fixation in four different materials. RESULTS: The TiFix system proved more resistant to deformation even when mounted with fewer screws than the non-angular stable systems. CONCLUSION: This system results in greater stability even when fewer screws are used. For the clinician this means smaller access incisions, less soft tissue trauma, better aesthetic results, decreased duration of operation and a reduction of costs.

In vitro evaluation of the resistance of three types of fixation to treat fractures of the mandibular angle.

The purpose of this study was to compare the mechanical resistance of three different plates used to treat fractures of the mandibular angle: a regular 4-hole plate, a longer 4-hole plate (both positioned using the Champy technique), and a 3-dimensional plate positioned over the oblique line. Three equal groups of replicas of human dentate mandibles made out of polyurethane resin were used (n=21 in each group). The force was applied perpendicular to the occlusal plane at a rate of 2mm/minute at three different points: the first molar on the sectioned side; the first molar on the contralateral side; and between the central incisors. This was followed by a resistance-to-load test. The two varying factors (type of plate and site-of-load application) were tested by analysis of variance, and probabilities of less than 0.05 were accepted as significant. There were no significant differences between the subgroups, or between the mean values of the different types of plates (p=0.925). The three types of plates showed similar mechanical behaviour, which showed that the 3-dimensional plates positioned over the oblique line can produce mechanical scores similar to those of conventional plates.