Internal fixation with headless compression screws and back buttress plate for treatment of old Hoffa fracture

Objective： To analyze the early clinical and radiographic outcomes of Hoffa fractures treated by a standard protocol of open reduction and internal fixation using headless compression screws combined with back buttress plate in a consecutive series of 8 Chinese patients. Methods： Open reduction and internal fixation was performed on all patients. The fractures were anatomical- ly reduced and held temporarily by K-wire. If the ends of fractures were atrophic, autologous bone graft from the ipsilateral iliac crest was packed between the ends. Then the fracture fragments were fixed with AO 6.5 mm headless compression cannulated screws. At least two screws were used to provide rotational stability. One pre-contoured reconstruction plate was placed on the nonarticular surface posteromedially or posterolaterally as back buttress plate. Results： All the patients were followed up for at least 12 months （range 12-25 months）. All fractures achieved anatomical reduction and healed clinically and radiographically. At recent follow-up, the mean flexion degree was 120.6° （range 110°-135°） and the mean extension degree was 2.5° （range 0°-5°）. The average visual analogue scale score was 1.6 points （range 0-3）. Six patients were assessed as excellent and 2 as good according to the hospital for special surgery knee score system. There were no superficial or deep infections, or hardware breakages. No patient had giving way or locking of the knee, though some had intermittent pain and swelling after strenuous exercise. Injury mechanism had significant influence on the functional outcome （P=0.046）. Conclusion： Headless compression screws combined with back buttress plate and/or autologous bone grafting to treat old Hoffa fracture is one of effective measures. It would be conducive to not only fracture healing but also early exercise and functional recovery.     

Orthogonal plating of intra-articular distal radius fractures with an associated radial column fracture via a single volar approach

IntroductionThe purpose of this study was to investigate the radiographic and functional outcome of orthogonal plating (two plates at right angles) via a single volar approach for fixation of intra-articular distal radius fractures with an associated radial column fracture.MethodsIn a retrospective, chart-based review, we identified 14 consecutive patients with an intra-articular distal radial fracture who had been treated with locked volar plate fixation and an additional radial column plate. Radial column plates were LCP Distal Radius Plates 2.4; volar plates were LCP Distal Radius Plates 2.4 (n = 13) or LCP T-plate (n = 1). These patients were operated on using the extended volar flexor carpi radialis (FCR) approach as described by Orbay. Radiographic measurements, healing rates, time to union, complications, range of motion, the Gartland and Werley score, and the QuickDASH questionnaire were done in order to evaluate the radiographic and functional outcomes of this technique.ResultsThirteen of the 14 fractures healed within 7 weeks after surgery. Two implant removals were done. One patient had malposition of the fracture and carpal tunnel symptoms, which required a second surgery. No other complications (e.g., first dorsal compartment problems, radial plate prominence problems and radial sensory nerve problems) were observed. The average length of follow-up was 30 months (range, 12.8 months to 5.4 years). Radiographic results after healing were radial inclination 20°, radial length 11.4 mm, tilt 6° volar, ulnar variance ?0.5 mm, articular gap 0.1 mm and step-off 0.1 mm. Wrist range of motion was flexion–extension arc 93°, ulnar–radial deviation arc 49° and pronation–supination arc 152°. Nine patients scored ‘excellent’ on the Gartland and Werley score, while the remaining five patients scored ‘good’. The average QuickDASH score was 13.4.ConclusionAdditional fixation of a radial column process in an intra-articular distal radius fracture via the extended FCR approach using a standard volar plate and radial LCP resulted in good/excellent radiographic and functional outcome.Level of evidenceTherapeutic IV.     

Locking plate fixation of humeral head fractures with a telescoping screw. A comparative biomechanical study versus a standard plate

ObjectivesLocking plate fixation of humeral head fractures bares the risk of glenohumeral screw penetration. In order to circumvent this problem it is recommended to insert shorter locking screws having at least a 6 mm distance to the humeral head cortex. This in turn may reduce fixation stability and may lead to early varus displacement. One second frequent failure mechanism is cranial displacement of the greater tubercle. The study evaluates the biomechanical properties of a locking plate employing an additional telescoping screw that may enhance resistance to varus displacement. Screw in screw fixation of the greater tubercle may reduce the rate of cranial displacement.MethodsIn four paired fresh-frozen human cadaver humeri (age > 70 years) a Neer IV/3 fracture was created with a 5 mm osteotomy gap simulating metaphyseal comminution. Limbs were randomly assigned to receive plate fixation with an additional telescoping screw (Humerus Tele Screw: HTS) and on the contralateral limb Philos plate fixation before biomechanical evaluation (MTS-Bionix 858.2). Standard locking screws were placed in both groups 6 mm below the radiological head circumference; the telescoping screw was placed in the subchondral layer. The greater tubercle was fixed with an additional screw in both techniques, in the HTS group the screw was anchored in the sleeve of the telescrew (screw in screw fixation).FindingsFixation stability with a mean stiffness of 300.9 ± 28.8 N/mm in the HTS plate group proved to be significantly higher than in the Philos plate group (184.2 ± 23.4 N/mm; p = 0.006). The HTS plate also resisted higher loads in terms of fixation failure with loss of reduction at 290 ± 58.6 N in comparison to 205 ± 8.6 N for the Philos plate (p = 0.2). Displacement of the greater tubercle occurred in no case of the HTS plate group and in two out of four cases in the Philos plate group.InterpretationThe HTS plate provides high fixation stability in an in vitro humeral head fracture model and securely prevents displacement of the greater tubercle.     

Comparison of different locking plate fixation methods in lateral malleolus fractures

BackgroundSeveral fixation methods may be used for displaced lateral malleolar fractures. We aimed to compare clinical and radiologic outcomes associated with use of locking one third tubular plate vs. anatomical distal fibula locking plate in lateral malleolar fractures.MethodsA total of 62 orthopedic patients operated for lateral malleolus fracture were included in this retrospective study. Patients were divided into two groups regarding the plate used for fixation as locking one third tubular plate (group I; n = 37) and locking anatomical distal fibula plate (group II; n = 25). Data on Danis–Weber ankle fracture classification (Type A, Type B), duration of follow up, clinical outcome [ankle range of motion (ROM), American Orthopaedic Foot & Ankle Society (AOFAS) score], radiological outcomes (adequacy of reduction, loss of alignment), time to fracture healing and complications were recorded in study groups.ResultsNo significant difference was noted between groups in terms of AOFAS score [87.0 (73–100) vs. 85.0 (71–100), respectively (p = 0.339)] and no patients had severe restriction in sagittal and hindfoot motion in both groups. The two groups showed similar healing time [9.0 (7–13) weeks vs. 10.0 (8–13) weeks, respectively (p = 0.355)] and complication rate [0.0% vs. 4.0%, respectively (p = 0.403)].ConclusionsThis study revealed no significant difference between use of locking one third tubular plate and locking anatomical distal fibula plate in lateral malleolar fixation, in terms of clinical and radiological outcomes, complication rates and fracture healing time.     

Outcome of periprosthetic distal femoral fractures following knee arthroplasty

IntroductionThe majority of periprosthetic fractures around the knee occur at the supracondylar region of the distal femur. Fixation of distal femoral fractures in osteoporotic bone with short segment remains a challenge, especially after total knee arthroplasty (TKA). Internal fixation of these fractures using locking plates has become popular. The purpose of this study was to evaluate a consecutive series of periprosthetic supracondylar femoral fractures treated with locked periarticular plate fixation with regard to surgical procedure, complications and clinical outcome.Materials and methodsFrom two academic trauma centres, 55 consecutive periprosthetic distal femoral fractures (Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association, AO/OTA 33) were retrospectively identified as having been treated with locked plate fixation. Of these, 36 fractures in 35 patients (86.1% female) met the inclusion criteria. Patients had an average age of 73.2 years (range 54–95 years). Fixation constructs for plate length and working length were delineated. Nonunion, infection and implant failure were used as complication variables. Demographics were assessed. Outcome was addressed radiographically and clinically according to Kristensen et al.¹ by range of motion and pain.ResultsTwenty-five of 36 fractures (69.4%) healed after the index procedure. Eight of 36 fractures (22.2%) developed a nonunion with three fractures (8.3%) leading to hardware failure. Nine of the 36 patients (25%) were radiographically diagnosed with notching of the anterior femoral cortex. Regarding technical aspects, distance from the anterior flange of the femoral component to fracture was significantly shorter in patients with compared to without anterior notching (t = 3.68, p = 0.02). Patients who underwent submuscular plate insertion compared to an extensive lateral approach had a reduced nonunion risk (χ² = 0.05). No difference in infection rate was found for submuscular procedures compared with open procedures (χ² = 0.85). Range of motion was reduced in most of the patients and 13.5% had a persistent loss of extension of 5°. More than 77% of the patients reported no or only mild pain during the last office visit. Range of motion loss did not influence pain. Successful treatment according to Cain et al.² was achieved in 83%. Using Kristensen's¹ criteria, 56% of the knees had acceptable flexion.ConclusionOperative fixation of periprosthetic distal femoral fractures after TKA continues to be challenging. Notching of the anterior femoral cortex should be avoided. Loss of reduction and high failure rates still occur with locked plating and may be related to underlying factors. Indirect reduction and submuscular plate insertion technique reduce nonunion risk.     

Outcomes for four-part proximal humerus fractures treated with a locking compression plate and an autologous iliac bone impaction graft

ObjectivesThe study aims to evaluate outcomes of autologous iliac bone impaction grafts (AIBIGs) with locking-compression plates (LCPs) in four-part proximal humeral fracture.MethodsBetween October 2004 and October 2008, 21 AIBIG with LCP osteosyntheses were done for four-part proximal humeral fractures. Patients included seven males and 14 females. Their mean age at the time of the operation was 66.3 ± 16.9 years (range: 24–87 years). Five patients had high-energy fractures other than fall from standing height. There were two fracture-dislocation cases, and three valgus-impacted fractures. The length of the calcar segment attached to the articular segment was 7.04 ± 6.10 mm; 13 of the 21 cases had lengths less than 8 mm. Medial-hinge displacement was 16.77 ± 15.84 mm; 19 of the 21 cases had displacements more than 2 mm.ResultsThere was no avascular necrosis of the humeral head and union was achieved in all cases. Varus collapse and hardware-related complications were not observed. Postoperative neck-shaft angles were found to be 129 ± 9° (range: 109–146°). Neer scores were 92.0 ± 6.3 (range: 81–100).ConclusionThe results of using AIBIG with LCP for four-part proximal humeral fractures are excellent. There are significant bone defects in osteoporotic or comminuted fractures and LCP alone does not always provide reliable fixation. Therefore, meticulous technique and use of AIBIG in this complicated type of fracture can ensure a favourable outcome.     

Radiological assessment of the safe zone for medial minimally invasive plate osteosynthesis in the distal femur with computed tomography angiography

IntroductionSurgical treatment options for distal femur fractures include intramedullary nailing or plating using a lateral or lateral parapatellar approach. However, medial plating is required for additional stability in some fractures such as severely comminuted fractures and periprosthetic fractures, and in those for which use of a lateral plate or nail is not appropriate. This study aimed to explore the safe zone for medial minimally invasive plate osteosynthesis of the distal femur with computed tomography angiography.Material and methodsIn a series of 30 patients, the region of interest between the lesser trochanter (LT) to the adductor tubercle (AT) was divided into six levels (I to VI), and the distance from the femur to the femoral artery (FA) was measured. At each level, the medial half of the femur was divided into eight sections that were assigned ‘A to H’ from anteromedial to posteromedial, and the position of the FA and the deep femoral artery (DFA) was recorded.ResultsThe average length from the LT to AT was 295.0 mm. The average distance to FA was 38.0 mm, 29.9 mm, 26.9 mm, 27.0 mm, 21.8 mm, and 12.2 mm from level I to VI, respectively. The FA was positioned posteromedially below level IV and positioned at C–H below level II, which was out of the anterior aspect of the femur. The DFA was in the same location as the FA between levels II and III.ConclusionThe anteromedial aspect of the distal half of the femur is the safe zone, and a long plate can be positioned safely in this zone at the anterior aspect up to the level of 8 cm below the LT.     

Working length and proximal screw constructs in plate osteosynthesis of distal femur fractures

BackgroundThe study purpose is to evaluate the working length, proximal screw density, and diaphyseal fixation mode and the correlation to fracture union after locking plate osteosynthesis of distal femoral fractures using bridge-plating technique.MethodsA four-year retrospective review was performed to identify patients undergoing operative fixation of distal femur fractures with a distal femoral locking plate using bridge-plating technique for the metadiaphyseal region. Primary variables included fracture union, secondary surgery for union, plate working length, and diaphyseal screw technique and configuration. Multiple secondary variables including plate metallurgy and coronal plane fracture alignment were also collected.ResultsNinety-six patients with distal femur fractures with a mean age 60 years met inclusion criteria. None of the clinical parameters were statistically significant indicators of union. Likewise, none of the following surgical technique parameters were associated with fracture union: plate metallurgy, the mean working length, screw density and number of proximal screws and screw cortices. However, diaphyseal screw technique did show statistical significance. Hybrid technique had a statistically significant higher chance of union when compared to locking (p = 0.02). All proximal locking screw constructs were 2.9 times more likely to lead to nonunion.ConclusionsPlating constructs with all locking screws used in the diaphysis when bridge-plating distal femur locking plates were 2.9 times more likely to incur a nonunion. However, other factors associated with more flexible fixation constructs such as increased working length, decreased proximal screw number, and decreased proximal screw density were not significantly associated with union in this study.     

Biomechanical analysis of locked and non-locked plate fixation of the clavicle

IntroductionDuring plate fixation of clavicular fractures the brachial plexus and subclavian vessels are vulnerable to injury beneath the clavicle. Locking plate fixation allows for mono-cortical fixation, theoretically reducing the risk of injury to these structures. Biomechanical analysis of the performance of such fixation is limited, and this study was designed to explore this further as a treatment option in clavicle fractures.Materials and methodsFixation of fifteen simulated mid-shaft fractures was undertaken using a combination of mono-cortical locked, bicortical locked and bicortical non-locked plating methods in cadaveric clavicles. Samples were then tested via three-point bending to destruction, and the performance of each with respect to failure load, bending stress, bending stiffness and Young's modulus was then analysed. The influence of the number of cortices engaged and locking was also assessed.ResultsClavicles fixed with monocortical locking plates displayed a significantly lower bending stress (12 ± 1 MPa) than both the bicortical locking (28 ± 3 MPa, p = 0.015) and non-locking specimens (24 ± 3 MPa, p = 0.002). Engaging two cortices with the fixation produced a significant increase in failure load (291 ± 28 N vs 138 ± 48 N, p = 0.018) and bending stress (26 ± 2 MPa vs 9.9 ± 3.5 MPa, p = 0.002) compared to single cortex fixation.DiscussionThe greatest influence upon the performance of the fixation was the number of cortices engaged, with bicortical fixation performing significantly better than mono-cortical. Whether or not the fixation device was a locking one did not have a significant bearing upon the performance.ConclusionThis in vitro biomechanical analysis demonstrates that mono-cortical locked plating fails at significantly lower levels of load and stress than bicortical locked and non-locked plating in mid-shaft fractures of the clavicle, and caution would therefore be advised in its use as a fixation modality for these injuries.     

Calcar comminution as prognostic factor of clinical outcome after locking plate fixation of proximal humeral fractures

ObjectiveIn the treatment of proximal humeral fractures, the decision between open fixation and arthroplasty is often difficult. Applicable radiographic prognostic factors would be useful. The purpose of the present study was to investigate the influence of calcar comminution on the clinical and radiologic outcome after locking plate fixation of these fractures.MethodsIn patients with proximal humeral fractures that were treated by locking plate fixation, fracture morphology and the presence of comminution of the calcar were documented on preoperative radiographs. Follow-up for at least 2 years with radiologic assessment and functional outcome measurements including Constant score, subjective shoulder value (SSV), disabilities of the arm, shoulder and hand score (DASH), visual analogue scale (VAS) and short form (SF)-36 was performed.ResultsFollow-up examination (50.8 ± 20.6 months) was possible in 74 patients (46 female, 28 male, age 63.0 ± 15.9 years). Mean absolute Constant score (CS abs), CS adapted to age and gender (CS adap), DASH, SSV and VAS were 72.4 ± 14.5, 85.2 ± 17.3%, 15.7 ± 17.3, 80.3 ± 19.6% and 2.1 ± 2.2. Nonunion was present in 1.3%, cut-out in 5.4% and implant failure in 1.3%. Avascular necrosis (AVN) was seen in 12.2%, in three cases >24 months after the initial trauma. In the presence of calcar comminution, the clinical outcome (CS abs, CS adap, SSV and several parameters of SF-36) was significantly impaired, the odds ratio for these patients to have an absolute CS < 65 was 4.4 (95% confidence interval (CI): 1.4–13.7).ConclusionsThe treatment of proximal humeral fractures with locking plate fixation achieves good clinical mid-term results. Calcar comminution is a relevant and easy-to-detect prognostic factor for the functional and subjective outcome in these fractures.     

Biomechanical analysis of a novel femoral neck locking plate for treatment of vertical shear Pauwel's type C femoral neck fractures

BackgroundThe purpose of this study is to determine the biomechanical stability of a novel prototype femoral neck locking plate (FNLP) for treatment of Pauwels type C femoral neck fractures compared with other current fixation methods.MethodsForty femur sawbones were divided into groups and a vertical femoral neck fracture was made. Each group was repaired with one of the following: (CS) three parallel cancellous screws; (XCS) two cancellous lag screws into the head and one transverse lag screw into the calcar; and (FNLP) a novel FNLP with two 5.7 mm locking, one lag screw into the calcar and two screws into the shaft; and (AMBI) a two-hole, 135° AMBI plate with a derotation screw. All groups were tested for change in axial stiffness over 20 000 cycles, and rotational stiffness was measured before and after cyclic testing. A maximum load to failure test was also conducted. Results were compared with one-way analysis of variance (ANOVA) and Fisher protected least significant difference (PLSD).ResultsResults for axial stiffness show that AMBI, CS, XCS and FNLP are 2779.0, 2207.2, 3029.9 and 3210.7 N-m mm^?1, respectively. Rotational rigidity results are 4.5, 4.1, 17.1 and 18.7 N-m mm^?1. The average cyclic displacements were 0.75, 0.88, 0.80 and 0.65 mm, respectively. Destructive failure loads for AMBI, CS, XCS and FNLP were 2.3, 1.7, 1.6 and 1.9 kN, respectively.ConclusionsThe results of this experiment show statistically significant increases in axial stiffness for the FNLP compared with three traditional fixation methods. The FNLP demonstrates increased mechanical stiffness and combines the desirable features of current fixation methods.     

Surgical treatment of proximal humerus fractures using PHILOS plate

Objective：To evaluate functional outcome and complications of open reduction and internal fixation with proximal humeral internal locking system （PHILOS） plate for proximal humerus fractures.Methods：We reviewed 51 patients who underwent open reduction and internal fixation with PHILOS plate between the years 2007 to 2012.There were 35 men and 16 women with a mean age of 38 years （range 24-68）.There were 41 patients in the age group of ＜60 years and 10 patients in the age group of ＞60 years.According to Neer classification system,8,15 and 23 patients had 2-part,3-part,and 4-part fractures,respectively and 5 patients had 4-part fracture dislocation.All surgeries were carried out at our tertiary care trauma centre.Functional evaluation of the shoulder at final follow-up was done using Constant-Murley score.Results：The mean follow-up period was 30 months （range 12-44 months）.Two patients were lost to followup.Of the remaining 49 patients,all fractures were united clinically and radiologically.The mean time for radiological union was 12 weeks （range 8-20 weeks）.At the final follow-up the mean Constant-Murley score was 79 （range 50-100）.The results were excellent in 25 patients,good in 13 patients,fair in 6 patients and poor in 5 patients.During the follow-up,four cases of varus malunion,one case of subacromial impingement,one case of deep infection,one case of intraarticular screw penetration and one case of failure of fixation were noted.No cases of avascular necrosis,hardware failure,locking screw loosening or nonunion were noted.Conclusion：PHILOS provides stable fixation in proximal humerus fractures.To prevent potential complications like avascular necrosis,meticulous surgical dissection to preserve vascularity of humeral head is necessary.     

Plate selection for fixation of extra-articular distal humerus fractures: A biomechanical comparison of three different implants

Operative fixation of extra-articular distal humerus using a single posterolateral column plate has been described but the biomechanical properties or limits of this technique is undefined. The purpose of this study was to evaluate the mechanical properties of distal humerus fracture fixation using three standard fixation constructs.Two equal groups were created from forty sawbones humeri. Osteotomies were created at 80 mm or 50 mm from the tip of the trochlea. In the proximal osteotomy group, sawbones were fixed with an 8-hole 3.5 mm LCP or with a 6-hole posterolateral plate. In the distal group, sawbones were fixed with 9-hole medial and lateral 3.5 mm distal humerus plates and ten sawbones were fixed with a 6-hole posterolateral plate. Biomechanical testing was performed using a servohydraulic testing machine. Testing in extension as well as internal and external rotation was performed. Destructive testing was also performed with failure being defined as hardware pullout, sawbone failure or cortical contact at the osteotomy.In the proximal osteotomy group, the average bending stiffness and torsional stiffness was significantly greater with the posterolateral plate than with the 3.5 mm LCP. In the distal osteotomy group, the average bending stiffness and torsional stiffness was significantly greater with the posterolateral plate than the 3.5 mm LCP. In extension testing, the yield strength was significantly greater with the posterolateral plate in the proximal osteotomy specimens, and the dual plating construct in the distal osteotomy specimens. The yield strength of specimens in axial torsion was significantly greater with the posterolateral plate in the proximal osteotomy specimens, and the dual plating construct in the distal osteotomy specimens.Limited biomechanical data to support the use of a pre-contoured posterolateral distal humerus LCP for fixation of extra-articular distal humerus exists. We have found that this implant provided significantly greater bending stiffness, torsional stiffness, and yield strength than a single 3.5 mm LCP plate for osteotomies created 80 mm from the trochlea. At the more distal osteotomy, dual plating was biomechanically superior. Our results suggest that single posterolateral column fixation of extra-articular humerus fractures is appropriate for more proximal fractures but that dual plate fixation is superior for more distal fractures.     

Biomechanical comparison of different acetabular plate systems and constructs--the role of an infra-acetabular screw placement and use of locking plates

IntroductionThe aim of this study was the direct comparison of the static fixation strength of two common plate systems: MPS (Matta Pelvic System) and LPPS (Low Profile Plate System). Furthermore the role of a modified screw placement with addressing the infra-acetabular corridor and the use of locking screws were evaluated.Materials and methodsCustom made anterior column fractures in artificial SYNBONE pelves were fixed with different acetabular plates (group I: MPS, group II: LPPS none locking and group III: LPPS locking). Each pelvis was tested twice, with the additionally placed infra-acetabular lag screw [+] first, followed by a repeated measurement without the infra-acetabular screw [?]. Six pelves per group were tested under static loading with six cycles up to 800 N, each. The fracture displacement was measured in the weight bearing dome using an ultrasound based Zebris-3D-Motion Analyzer.ResultsThe MPS-plate had a less fixation strength compared to the LPPS-plate (mean ± SD of maximum fracture displacement [mm] in group I vs. group II = 0.63 ± 0.02 vs. 0.37 ± 0.02, p < 0.05). The locking feature did not increase the fracture fixation strength (mean ± SD of maximum fracture displacement [mm] in group II vs. group III: 0.37 ± 0.02 vs. 0.37 ± 0.03; ns).The infra-acetabular screw significantly reduces the maximum fracture displacement in all groups, independent of the plate systems ([Delta%] in group I = 50; group II = 63 and group III = 40; p < 0.05 each).ConclusionThe LPPS-plate performed superior fixation strength for anterior column fractures compared to the MPS-plate. The locking plate modality did not reduce the maximum fracture displacement, whereas the additional infra-acetabular screw placement actually doubles the fracture fixation strength independent of the used plate system.     

Biomechanical cadaver testing of a fixed-angle plate in comparison to tension wiring and screw fixation in transverse patella fractures

IntroductionOperative treatment of patella fractures is frequently associated with implant failure and secondary dislocation which can be attributed to the employed hardware. Therefore, a 2.7 mm fixed-angle plate designed for the treatment of patella fractures was tested biomechanically against the currently preferred methods of fixation. It was hypothesized that under simulated cyclic loading fixed-angle plating would be superior to modified anterior tension wiring or cannulated lag screws with anterior tension wiring.Materials and methodsEighteen human cadaver knees, matched by bone mineral density and age, were divided into three groups of six. After setting a transverse patella fracture each group received one of the osteosyntheses mentioned above. Repetitive testing over 100 cycles was performed at non-destructive loads by simulating knee motion from 90° flexion to full extension.ResultsAnterior tension wiring as well as lag screws with tension wiring showed significant fracture displacement after the initial cycle already. Both constructs, lag screws plus wiring (3.7 ± 2.7 mm) as well as tension wiring alone (7.1 ± 2.2 mm) displayed fracture displacement of >2 mm which is clinically regarded as failure. Those patellae stabilized with fixed-angle plates showed no significant fracture gap widening after completion of 100 cycles (0.7 ± 0.5 mm). The differences between the fixed-angle plate group and the other two groups were statistically significant (p < 0.05).ConclusionIn contrast to modified anterior tension wiring and cannulated lag screws with anterior tension wiring the bilateral fixed-angle plate was the only fixation device to stabilize transverse patella fractures securely and sustainably.     

Finite element analysis of different repair methods of Vancouver B1 periprosthetic fractures after total hip arthroplasty

ObjectiveTo use finite element analysis to study the stability of different fixation methods used to repair Vancouver type B1 periprosthetic fractures occurring after total hip arthroplasty (THA).MethodsAn artificial femur was used as the basis for the solid model; U2 series femoral stem (United Orthopedic Corporation, Hsinchu, Taiwan) was used for modelling of the prosthesis; and the modelling of the cable plate, wires and screws was based on information given in the manufacturer's catalogue (Zimmer, Warsaw, IN, USA). The analysis model was constructed using the ANSYS software, and all material settings were based on literature values. A six-orifice cable plate, unicortical screws (20 mm long and 4.5 mm in diameter) and bicortical screws (50 mm long and 4.5 mm in diameter) were constructed. Four analysis models were defined. The basic model had a plate and three cable wires above the fracture line and two bicortical screws below the fracture line. In the second model, two unicortical screws were added above the fracture line. In the third model, three wires were added below the fracture line. In the fourth model, both the proximal screws of the second model and the distal wires of the third model were added to the basic model. To ensure that the numerical values produced by analysis reached convergence, mesh convergence was tested.ResultsAdding two proximal unicortical screws to the basic Ogden construct (plate, proximal wires and distal screws) lessened displacement of the fracture and decreased the von Mises stress on the repair. Adding three distal wires to the basic construct had no noticeable effect.ConclusionBetter fixation power is achieved by using both proximal and distal screws (the locking-plate concept) in treating Vancouver type B1 periprosthetic fracture after THA.     

Malalignment after minimally invasive plate osteosynthesis in distal femoral fractures

IntroductionAlthough minimally invasive plate osteosynthesis (MIPO) is a preferred operative treatment for fractures of the distal femur, malalignment is a significant concern because of indirect reduction of the fracture. The purpose of this study, therefore, was to evaluate radiologic alignment after MIPO for distal femoral fractures.Patients and methodsOf the 138 patients with fracture of the distal femur who underwent MIPO, we enrolled 51 patients in whom bilateral rotational alignment could be assessed by postoperative computed tomography (CT). The patients included 32 men and 19 women, with a mean age of 54.3 years. Thirteen patients had femoral shaft fractures (according to the AO/OTA classification: 32-A, n = 2; 32-B, n = 6; 32-C, n = 5), whereas 38 patients had distal femoral fractures (33-A, n = 7; 33-C, n = 31). Coronal and sagittal alignments were assessed using simple radiography, whereas rotational alignment was assessed using CT. According to the difference between the affected and unaffected sides, we divided the patients into satisfactory and unsatisfactory groups (reference point of 8°, using Handolin’s classification). Thereafter, we determined which factors can lead to malalignment, including fracture location (distal femoral shaft fracture or metaphyseal fracture), fracture pattern (simple fracture, n = 15; complex fractures, n = 36 patients), coronal and sagittal alignments, and combined ipsilateral long bone fractures.ResultsCoronal and sagittal alignment were satisfactory in 96.2% (average, 2.8°) and 98% (average, 2.2°), respectively, whereas the rotational alignment was satisfactory in 56.9% of patients. Leg length discrepancy was satisfactory in 92.3% of the patients (average, 10.9 mm). Concerning rotational malalignment, an unsatisfactory result was obtained in 48.6% of subjects with complex fractures and 26.7% of subjects with simple fractures (p = 0.114). No significant correlation was noted between the angular deformity in the coronal and sagittal planes and the degree of rotational alignment (p = 0.607 and 0.774, respectively).ConclusionsRegardless of the fracture pattern, rotational malalignment may occur at an extremely high rate after MIPO for fractures of the distal femur.     

Predictors of the postoperative range of finger motion for comminuted periarticular metacarpal and phalangeal fractures treated with a titanium plate

BackgroundPlate and screw fixation was introduced for complex fractures of the hand. Several risk factors for a poor functional outcome have been identified, but there is a paucity of evidence regarding predictors of finger stiffness in difficult hand fractures. The purpose of this prospective cohort study was to identify independent prognostic factors of the postoperative total active motion (%TAM) in the treatment of metacarpal and phalangeal fractures.MethodsSeventy-two patients (62 males, 10 females; 37 ± 15 years) with periarticular fractures involving metaphyseal comminution and displacement were evaluated at a minimum of 1 year following surgery. There were 49 phalangeal bone fractures, 30 intra-articular fractures and 20 associated soft-tissue injuries. The locations of plate placement were lateral in 42 patients and dorsal in 30. The mean duration from injury to surgery was 7.6 days (range, 0–40 days). There were eight examined variables related to patient characteristics (age, gender and hand dominance), fracture characteristics (fracture location, joint involvement and associated soft-tissue injury) and surgical variables (location of plate placement and duration from injury to surgery). Univariate and multivariate linear regression analysis were used to identify the degree to which variables affect %TAM at the final follow-up.ResultsUnivariate analysis indicated moderate correlations of %TAM with fracture location, associated soft-tissue injury and age. Multiple linear regression modelling including fracture location, age and associated soft-tissue injury resulted in formulae that could account for 46.3% of the variability in %TAM: fracture location (β = ?0.388, p < 0.001), age (β = ?0.339, p < 0.001) and associated soft-tissue injury (β = –0.296, p = 0.002).ConclusionPhalangeal fracture, increasing age and associated soft-tissue injury were important risk factors to identify the postoperative %TAM in the treatment of comminuted periarticular metacarpal or phalangeal fracture with a titanium plate.     

Biomechanical effect of anterior talofibular ligament injury in Weber B lateral malleolus fractures after lateral plate fixation: A finite element analysis

ObjectiveTo determine the biomechanical effect of anterior talofibular ligament injury in Weber B lateral malleolus fractures after lateral plate fixation.MethodA three-dimensional model was established based on CT images from a healthy volunteer. The simulation of lateral malleolus fracture, and the modeling and assembly of plate were completed by referring to characteristics of Weber B lateral malleolus fractures, as well as the technical characteristics of open reduction and internal fixation of lateral plate. Operating conditions were set up for groups A−D. The proximal end of the model was restrained in all four groups, 200 N of upward force and 100 N of backward force were applied at anterior of talus head in order to simulate the dorsiflexion of ankle joint. Biomechanical differences of the lateral plate were observed under various conditions of different ligament ruptures.ResultsThe maximum stress value of group A was the smallest, approximately 78.47 N, while that of group C was the largest, approximately 238.83 N. The maximum stress value of group B was about 91.69 N; and that of group D was about 184.08N. Importantly, location of the maximum stress in group D (CUT ATaF) was displaced from the posterior edge to the anterior edge of the plate, which was different from those of the other three groups.ConclusionsThe anterior talofibular ligament injury may be a major contributing factor to the stress of lateral plate fixation following Weber B lateral malleolus fracture. It should be considered as an essential risk factor for evaluation of the stability in these fractures.     

Dynamic hip screw with locking side plate: a viable treatment option for intertrochanteric fracture

Objective： Dynamic hip screw （DHS） is recommended for the fixation of stable intertrochanteric fractures. Its postoperative cut-out rate ranges from I% to 6%. In osteoporotic bone, normal screws in DHS blade provide less anchorage compared to locking screws. This study aims to compare DHS with locking side plate and conventional side plate. Methods： Fifty consecutive patients with intertrochanteric fractures were randomly allocated for fixation with a standard DHS （group A） and locking DHS （Combi plate, group B）. We compared the clinical and radiological outcomes for the conventional DHS and locking DHS in intertrochanteric fractures. Functional outcome was evaluated using the Parker mobility score. Results： Coxa valga was found more frequently in group A than in group B （12% vs. 0%, P=0.42）. Coxa vara showed the same trend （12% vs. 8%, P=0.81）. Rate of restoration of postoperative neck-shaft angle within 20° of sound side was higher in group B （8% cases） than in group A （4% cases, P=0.98）. The rate of anteversion angle restoration within 10° of sound side was also higher in group B （100% vs. 88%, P=0.85）. The average lag screw slippage in group A and group B was 3.2 mm and 4.2 mm, the average fracture union duration was 17.1 weeks and 16.4 weeks, and the mean Parker score was 5.6 and 5.8 respectively. Screw cut-out was seen in one patient in group A. No cut-out was seen in any of the patient in group B. No patient developed deep infection, avascular necrosis, deep vein thrombosis or any other significant complications. Conclusion： The present study demonstrated that treating intertrochanteric fracture with a locking DHS allows sound bone healing and is not associated with any major complications. Although this report is promising, it should be interpreted with caution because only a prospective study with a large sample size would allow definitive conclusion.