Treatment of simple and complex patella fractures represents a challenging clinical problem. Controversy exists regarding the most appropriate fixation method. Tension band wiring, aiming to convert the pulling forces on the anterior aspect of the patella into compression forces across the fracture site, is the standard of care, however, it is associated with high complication rates. Recently, anterior variable-angle locking plates have been developed for treatment of simple and comminuted patella fractures. The aim of this study was to investigate the biomechanical performance of the novel anterior variable-angle locking plates versus tension band wiring used for fixation of simple and complex patella fractures. Sixteen pairs of human cadaveric knees were used to simulate either two-part transverse simple AO/OTA 34-C1 or five-part complex AO/OTA 34-C3 patella fractures by means of osteotomies, with each fracture model created in eight pairs. The complex fracture pattern was characterized with a medial and a lateral proximal fragment, together with an inferomedial, an inferolateral and an inferior fragment mimicking comminution around the distal patellar pole. The specimens with simple fractures were pairwise assigned for fixation with either tension band wiring through two parallel cannulated screws, or an anterior variable-angle locking core plate. The knees with complex fractures were pairwise treated with either tension band wiring through two parallel cannulated screws plus circumferential cerclage wiring, or an anterior variable-angle locking three-hole plate. Each specimen was tested over 5000 cycles by pulling on the quadriceps tendon, simulating active knee extension and passive knee flexion within the range from 90° flexion to full knee extension. Interfragmentary movements were captured by motion tracking. For both fracture types, the articular displacements, measured between the proximal and distal fragments at the central aspect of the patella between 1000 and 5000 cycles, together with the relative rotations of these fragments around the mediolateral axis were all significantly smaller following the anterior variable-angle locked plating compared with the tension band wiring, p < 0.01 From a biomechanical perspective, anterior locked plating of both simple and complex patella fractures provides superior construct stability versus tension band wiring.
This study aims to compare the outcomes of Volar locking plating (VLP) versus percutaneous Kirschner wires (K-wire) fixation for surgical management of distal radius fractures. We systematically searched multiple databases, including MEDLINE for randomized controlled trials (RCTs) comparing outcomes of VLP fixation and K-wire for treatment of distal radius fracture in adults. The methodological quality of each study was assessed by the Cochrane Risk of Bias tool. Patient-reported outcomes, functional outcomes, and complications at 1 year follow up were evaluated. Meta-analysis was performed using random-effects models and results presented as risk ratios (RRs) or mean differences (MDs) with 95% confidence interval (CI). 13 RCTs with 1336 participants met the inclusion criteria. Disabilities of the Arm, Shoulder and Hand (DASH) scores were significantly better for VLP fixation (MD= 2.15; 95% CI, 0.56-3.74; P = 0.01; I2=23%). No significant difference between the two procedures for grip strength measured in kilograms (MD= −3.84; 95% CI,-8.42-0.74; P = 0.10; I2=52%) and Patient-Rated Wrist Evaluation (PRWE) scores (MD= −0.06; 95% CI,-0.87-0.75; P = 0.89; I2=0%). K-wire treatment yielded significantly improved extension (MD= −4.30; P=0.04) but with no differences in flexion, pronation, supination, and radial deviation (P >0.05). The risk of complications and rate of reoperation were similar for the two procedures (P >0.05). This meta-analysis suggests that VLP fixation improves DASH score at 12 months follow up, however, the difference is small and unlikely to be clinically important. Existing literature does not provide sufficient evidence to demonstrate the superiority of either VLP or K-wire treatment in terms of patient-reported outcomes, functional outcomes, and complications.
Treatment of both simple and complex patella fractures is a challenging clinical problem. The aim of this study was to investigate the biomechanical performance of recently developed lateral rim variable angle locking plates versus tension band wiring used for fixation of simple and complex patella fractures. Twelve pairs of human anatomical knees were used to simulate either two-part transverse simple AO/OTA 34C1 or five-part complex AO/OTA 34C3 patella fractures by means of osteotomies, with each fracture model created in six pairs. The complex fracture pattern was characterized by a medial and a lateral proximal fragment, together with an inferomedial, an inferolateral, and an inferior fragment mimicking comminution around the distal patellar pole. The specimens with simple fractures were pairwise assigned for fixation with either tension band wiring through two parallel cannulated screws, or a lateral rim variable angle locking plate. The knees with complex fractures were pairwise treated with either tension band wiring through two parallel cannulated screws plus circumferential cerclage wiring, or a lateral rim variable angle locking plate. Each specimen was tested over 5000 cycles by pulling on the quadriceps tendon, simulating active knee extension and passive knee flexion within the range of 90° flexion to full knee extension. Interfragmentary movements were captured via motion tracking. For both fracture types, the longitudinal and shear articular displacements measured between the proximal and distal fragments at the central patella aspect between 1000 and 5000 cycles, together with the relative rotations of these fragments around the mediolateral axis were all significantly smaller following the lateral rim variable angle locked plating compared with tension band wiring, p<0.01. Lateral rim locked plating of both simple and complex patella fractures provides superior construct stability versus tension band wiring under dynamic loading.
Proximal humerus fractures (PHF) are the third most common fractures in the elderly. Treatment of complex PHF has remained challenging with mechanical failure rates ranging up to 35% even when state-of-the-art locked plates are used. Secondary (post-operative) screw perforation through the articular surface of the humeral head is the most frequent mechanical failure mode, with rates up to 23%. Besides other known risk factors, such as non-anatomical reduction and lack of medial cortical support, in-adverse intraoperative perforation of the articular surfaces during pilot hole drilling (overdrilling) may increase the risk of secondary screw perforation. Overdrilling often occurs during surgical treatment of osteoporotic PHF due to minimal tactile feedback; however, the awareness in the surgical community is low and the consequences on the fixation stability have remained unproved. Therefore, the aim of this study was to evaluate biomechanically whether overdrilling would increase the risk of cyclic screw perforation failure in unstable PHF. A highly unstable malreduced 3-part fracture was simulated by osteotomizing 9 pairs of fresh-frozen human cadaveric proximal humeri from elderly donors (73.7 ± 13.0 ys, f/m: 3/6). The fragments were fixed with a locking plate (PHILOS, DePuy Synthes, Switzerland) using six proximal screws, with their lengths selected to ensure 6 mm tip-to-joint distance. The pairs were randomized into two treatment groups, one with all pilot holes accurately predrilled (APD) and another one with the boreholes of the two calcar screws overdrilled (COD). The constructs were tested under progressively increasing cyclic loading to failure at 4 Hz using a previously developed setup and protocol. Starting from 50 N, the peak load was increased by 0.05 N/cycle. The event of initial screw loosening was defined by the abrupt increase of the displacement at valley load, following its initial linear behavior. Perforation failure was defined by the first screw penetrating the joint surface, touching the artificial glenoid component and stopping the test via electrical contact. Bone mineral density (range: 63.8 – 196.2 mgHA/cm3) was not significantly different between the groups. Initial screw loosening occurred at a significantly lower number of cycles in the COD group (10,310 ± 3,575) compared to the APD group (12,409 ± 4,569), p = 0.006. Number of cycles to screw perforation was significantly lower for the COD versus APD specimens (20,173 ± 5,851 and 24,311 ± 6,318, respectively), p = 0.019. Failure mode was varus collapse combined with lateral-inferior translation of the humeral head. The first screw perforating the articular surface was one of the calcar screws in all but one specimen. Besides risk factors such as fracture complexity and osteoporosis, inadequate surgical technique is a crucial contributor to high failure rates in locked plating of complex PHF. This study shows for the first time that overdrilling of pilot holes can significantly increase the risk of secondary screw perforation. Study limitations include the fracture model and loading method. While the findings require clinical corroboration, raising the awareness of the surgical community towards this largely neglected risk source, together with development of devices to avoid overdrilling, are expected to help improve the treatment outcomes.
Treatment of comminuted intraarticular calcaneal fractures remains controversial and challenging. Anatomic reduction with stable fixation has demonstrated better outcomes than nonoperative treatment of displaced intraarticular fractures involving the posterior facet and anterior calcaneocuboid joint (CCJ) articulating surface of the calcaneus. The aim of this study was to investigate the biomechanical performance of three different methods for fixation of comminuted intraarticular calcaneal fractures. Comminuted calcaneal fractures, including Sanders III-AB fracture of the posterior facet and Kinner II-B fracture of the CCJ articulating calcaneal surface, were simulated in 18 fresh-frozen human cadaveric lower legs by means of osteotomies. The ankle joint, medial soft tissues and midtarsal bones along with the ligaments were preserved. The specimens were randomized according to their bone mineral density to 3 groups for fixation with either (1) 2.7 mm variable-angle locking anterolateral calcaneal plate in combination with one 4.5 mm and one 6.5 mm cannulated screw (Group 1), (2) 2.7 mm variable-angle locking lateral calcaneal plate (Group 2), or (3) interlocking calcaneal nail with 3.5 mm screws in combination with 3 separate 4.0 mm cannulated screws (Group 3). All specimens were biomechanically tested until failure under axial loading with the foot in simulated midstance position. Each test commenced with an initial quasi-static compression ramp from 50 N to 200 N, followed by progressively increasing cyclic loading at 2Hz. Starting from 200 N, the peak load of each cycle increased at a rate of 0.2 N/cycle. Interfragmentary movements were captured by means of optical motion tracking. In addition, mediolateral X-rays were taken every 250 cycles with a triggered C-arm. Varus deformation between the tuber calcanei and lateral calcaneal fragments, plantar gapping between the anterior process and tuber fragments, displacement at the plantar aspect of the CCJ articular calcaneal surface, and Böhler angle were evaluated. Varus deformation of 10° was reached at significantly lower number of cycles in Group 2 compared to Group 1 and Group 3 (P ≤ 0.017). Both cycles to 10° plantar gapping and 2 mm displacement at the CCJ articular calcaneal surface revealed no significant differences between the groups (P ≥ 0.773). Böhler angle after 5000 cycles (1200 N peak load) had significantly bigger decrease in Group 2 compared to both other groups (P ≤ 0.020). From biomechanical perspective, treatment of comminuted intraarticular calcaneal fractures using variable-angle locked plate with additional longitudinal screws or interlocked nail in combination with separate transversal screws seems to provide superior stability as opposed to variable-angle locked plating only.
Being challenging, multifragmentary proximal tibial fractures in patients with severe soft tissue injuries and/or short stature can be treated using externalized locked plating. A recent finite element study, investigating the fixation stability of plated unstable tibial fractures with 2-mm, 22-mm and 32-mm plate elevation under partial and full weight-bearing, reported that from a virtual biomechanical point of view, externalized plating seems to provide appropriate relative stability for secondary bone healing under partial weight-bearing during the early postoperative phase. The aim of the current study was to evaluate the clinical outcomes of using a LISS plate as a definitive external fixator for the treatment of multifragmentary proximal tibial fractures. Following appropriate indirect reduction, externalized locked plating was performed and followed up in 12 patients with multifragmentary proximal tibial fractures with simple intraarticular involvement and injured soft tissue envelope.Introduction
Methods
The incidence of distal femoral fractures in the geriatric population is growing and represents the second most common insufficiency fracture of the femur following fractures around the hip joint. Fixation of fractures in patients with poor bone stock and early mobilisation in feeble and polymorbide patients is challenging. Development of a fixation approach for augmentation of conventional LISS (less invasive stabilization system) plating may result in superior long-term clinical outcomes and enhance safe weight bearing. The aim of this study was to investigate the biomechanical competence of two different techniques of augmented LISS plating for treatment of osteoporotic fractures of the distal femur in comparison to conventional LISS plating.Introduction
Objectives
Periarticular metastasis may be treated with endoprosthetic reconstruction. The extensive surgery required may not, however, be appropriate for all patients. Our aim was to establish if the outcome of locking plate fixation in selected patients with periarticular metastases. Prospective data collection was performed. Twenty one patients underwent surgery for periarticular metastatic tumours. The median duration of follow-up for surviving patients was one year. There have been no cases of implant failure and no requirement for revision surgery. Pain relief was excellent or good in the majority of patients. Patients who had sustained a fracture prior to fixation had restoration of their WHO performance status. All patients had a dramatic improvement in their MSTS scores. The median pre-operative score was 15% (0%-37%) improving to a median score of 80% (75% -96%) post operatively. Locking plates provide reliable fixation and excellent functional restoration in selected patients suffering from periarticular metastatic bone disease.
Osteosynthesis of high-energy metaphyseal proximal tibia fractures is still challenging, especially in patients with severe soft tissue injuries and/or short stature. Although the use of external fixators is the traditional treatment of choice for open comminuted fractures, patients' acceptance is low due to the high profile and therefore the physical burden of the devices. Recently, clinical case reports have shown that supercutaneous locked plating used as definite external fixation could be an efficient alternative. Therefore, the aim of this study was to evaluate the effect of implant configuration on stability and interfragmentary motions of unstable proximal tibia fractures fixed by means of externalized locked plating. Based on a right tibia CT scan of a 48 years-old male donor, a finite element model of an unstable proximal tibia fracture was developed to compare the stability of one internal and two different externalized plate fixations. A 2-cm osteotomy gap, located 5 cm distally to the articular surface and replicating an AO/OTA 41-C2.2 fracture, was virtually fixed with a medial stainless steel LISS-DF plate. Three implant configurations (IC) with different plate elevations were modelled and virtually tested biomechanically: IC-1 with 2-mm elevation (internal locked plate fixation), IC-2 with 22-mm elevation (externalized locked plate fixation with thin soft tissue simulation) and IC-3 with 32-mm elevation (externalized locked plate fixation with thick soft tissue simulation). Axial loads of 25 kg (partial weightbearing) and 80 kg (full weightbearing) were applied to the proximal tibia end and distributed at a ratio of 80%/20% on the medial/lateral condyles. A hinge joint was simulated at the distal end of the tibia. Parameters of interest were construct stiffness, as well as interfragmentary motion and longitudinal strain at the most lateral aspect of the fracture. Construct stiffness was 655 N/mm (IC-1), 197 N/mm (IC-2) and 128 N/mm (IC-3). Interfragmentary motions under partial weightbearing were 0.31 mm (IC-1), 1.09 mm (IC-2) and 1.74 mm (IC-3), whereas under full weightbearing they were 0.97 mm (IC-1), 3.50 mm (IC-2) and 5.56 mm (IC-3). The corresponding longitudinal strains at the fracture site under partial weightbearing were 1.55% (IC-1), 5.45% (IC-2) and 8.70% (IC-3). From virtual biomechanics point of view, externalized locked plating of unstable proximal tibia fractures with simulated thin and thick soft tissue environment seems to ensure favorable conditions for callus formation with longitudinal strains at the fracture site not exceeding 10%, thus providing appropriate relative stability for secondary bone healing under partial weightbearing during the early postoperative phase.
Displaced proximal Humeral fractures at Inverclyde Royal Hospital prior to 2008 were previously treated with the antegrade Acumed Polaris Proximal Humeral, predominantly in 2 part fractures. The Philos plate was introduced in 2008, initially being used to treat select non unions, and then expanded to acute fractures. The aim of this study was to assess time to union and complications in the lower volume District General setting comparing to published outcomes. From February 2008 – January 2011, 20 patients were identified. Age range 49–75 (mean 61.2) years, 8 male; 12 female. Left 9, Right 11 Neers 2 part 35%; 3 35%; 4 30%. 16 (80%) were performed in acute fractures with 4 for non-unions, 3 of which were previous polaris nail fixations. 2 patients were lost to follow up after 6/52 but were progressing well. Union was confirmed radiologically and clinically in all but 2 remaining patients (10%), one of whom suffered a significant complication of plate fracture, the second treated with revision for painful non union. 2 other significant complications were observed: transient axillary nerve palsy and deep infection. Both of these patients recovered with delayed union observed in the infection case (52 weeks). Time to union range was 8–52 weeks (mean 17.1). The literature shows a high failure rate of up to 45% with intramedullary nail fixation and limited predominantly to 2 part fractures with risk of damage to the rotator cuff. This study shows a satisfactory union rate using the Philos of 90% with only 3 (15%) requiring further surgery for non-union, plate fracture and infection. 3 and 4 part fractures composed 65% of case load. Early results indicate satisfactory outcomes compared to current published literature.
Endoprosthetic replacement is often the preferred treatment for neoplastic lesions as internal fixation has been shown to have a high failure rate. Due to anatomical location, disease factors and patient factors internal fixation may be the treatment of choice. No reports exist in the literature regarding the use of locking plates in the management of neoplastic long bone lesions. Data was collected prospectively on the first 10 patients who underwent locking plate fixation of neoplastic long bone lesions. Data was collected on the nature of the lesion, surgery performed, complications and outcome. The patients mean age was 56.6 (15–88). Six lesions were metastatic, one haematological (myeloma) and 3 were primary bone lesions (lymphoma, Giant cell tumour, simple bone cyst). In nine cases a fracture through the lesion had occurred. Anatomical locations of the lesions were; proximal humerus (four), proximal tibia (three), distal femur (two) and distal tibia (one). Cement augmentation of significant bone defects was necessary in seven cases. The mean hospital stay was 8 days (3–20). There were no inpatient complications. Five patients received adjuvant radiotherapy and one patient received neo-adjuvant radiotherapy to the lesion. There have been 3 deaths. All were due to metastatic disease and occurred between 6 and 12 months after surgery. The mean follow up in the surviving patients is currently 9 months (5–16). There have been no fixation related complications. Patients who had suffered a fracture had restoration of their WHO performance status. At last follow up the mean MSTS was 78% (57–90) for lower limb surgery and 70% (63–76) for upper limb surgery. These figures compare favourably with the results of endoprosthetic replacement. The early results of locking plate fixation for neoplastic long bone lesions are excellent. Follow up continues to observe how these devices perform in the long term.
Getting the distal locking screw lengths right in volar locking plate fixation of distal radius is crucial. Long screws can lead to extensor tendon ruptures whereas short screws can lead to failure of fixation, especially if there is dorsal comminution of the fracture. The aim of our study was to determine the distal radius anatomy in relation to sagittal lengths and distance between dorsal bone edge and extensor tendons based on MRI scan. One hundred consecutive MRI scans of wrist were reviewed by two of the authors on two occasions. All MRI scans were performed for different wrist pathologies except distal radius fractures or tumours. An axial image, two cuts proximal to the last visible articular surface, was selected. Sagittal length at 5 different widths, maximum volar width, radial overhang over distal radio-ulnar joint and the distance between dorsal bone edge and extensor tendons were measured.Introduction
Method
Controversy exists whether a single proximal lateral tibia (PLT) locked plate is adequate for bicondylar fractures and whether the use of integral raft screws makes the use of bone graft less important. 57 consecutive patients who underwent reconstruction with a locked PLT plate were retrospectively reviewed. Radiographs were examined for operative reduction and subsequent loss of reduction. 55 patients were followed-up for an average of 27 weeks. Fractures were divided into unicondylar (Group 1, n=33) and bicondylar (Group 2, n=22). Union occurred in all patients, with no revisions or removal of metalwork at final follow-up. In 50 patients (88%), the fracture was reduced to within 2mm of anatomical. Articular surface collapse of >2mm occurred in three patients. Nine patients underwent bone grafting with no difference in outcome. A supplementary medial plate was used in three patients with a separate posteromedial fragment. Except for a separate posteromedial fragment, the use of a single locked PLT plate for bicondylar fractures allows union to occur without failure. With the use of integral raft screws, the need for bone graft is questionable. The short-term radiological results and complication rate of PLT locked plating is excellent.
To compare the functional outcome of Distal Tibial Metaphyseal fracture treated with Circular frame compared vs. Locking Plate Distal Tibial Metaphyseal fractures were retrospectively identified over an 18 month period. Each fracture was assessed individually using radiographs. All paediatric, compound, tibial plateau and intra-articular fractures were excluded from the study. Other methods of fixation including intramedullary nailing were also excluded. The remaining fractures were assigned to either the circular frame fixation or the locking plate intervention group. Outcomes were assessed using radiographs for union dates and microbiology results for evidence of infection. Patients were followed up by postal questionnaires, which included a modified American Orthopaedic Foot and Ankle Score (AOFAS), the Olerud and Molander Score (O&M) and a custom questionnaire. The custom questionnaire asked about co-morbidities, smoking status and work days lost following surgery. After exclusions, 30 patients (Frame=15, Plate=15), were sent out questionnaires via post. We received completed questionnaires from 21 patients (Frame=11, Plate=10) giving us a response rate of 70%. Results show no difference in infection rates, skin necrosis, non-union or re-operation rates. There was also no significant difference in patient AOFAS and O&M scores at follow up.Statement of Purpose
Methods and Results
Several clinical and radiological studies have confirmed the benefits of using Volar Locking Plates (VLPs) to treat unstable distal radius fractures. The “theoretical” advantage of VLPs compared to standard plate fixation is that VLPs, through their design, intrinsically provide angular stability for most fracture configurations including comminuted fractures and, quite possibly, osteoporotic fractures. However few studies have compared the clinical results of patients of different ages who have been treated using VLPs. The aim of this study was to compare the clinical outcomes of VLP fixation of displaced distal radius in younger (<59 yrs) and older (>60yrs) patients.Introduction
Aim
Fixation of osteoporotic proximal humerus fractures remains challenging even with state-of-the-art locking plates. Despite the demonstrated biomechanical benefit of screw tip augmentation with bone cement, the clinical findings have remained unclear, potentially as the optimal augmentation combinations are unknown. The aim of this study was to systematically evaluate the biomechanical benefits of the augmentation options in a humeral locking plate using finite element analysis (FEA). A total of 64 cement augmentation configurations were analyzed using six screws of a locking plate to virtually fix unstable three-part fractures in 24 low-density proximal humerus models under three physiological loading cases (4,608 simulations). The biomechanical benefit of augmentation was evaluated through an established FEA methodology using the average peri-screw bone strain as a validated predictor of cyclic cut-out failure.Aims
Methods