Locking plate technology and its role in osteoporotic fractures

Severity of Complications after Locking Plate Osteosynthesis in Distal Femur Fractures

Background: Locked plating for distal femur fractures is widely recommended and used. We systematically reviewed clinical studies assessing the benefits and harms of fracture fixation with locked plates in AO/OTA Type 32 and 33 femur fractures. Methods: A comprehensive literature search of PubMed, Embase, Cinahl, Web of Science, and the Cochrane Database was performed. The studies included randomized and non-randomized clinical trials, observational studies, and case series involving patients with distal femur fractures. Studies of other fracture patterns, studies conducted on children, pathological fractures, cadaveric studies, animal models, and those with non-clinical study designs were excluded. Results: 53 studies with 1788 patients were found to satisfy the inclusion and exclusion criteria. The most common harms were nonunion (14.8%), malunion (13%), fixation failure (5.3%), infection (3.7%), and symptomatic implant (3.1%). Time to full weight-bearing ranged from 5 to 24 weeks, averaging 12.3 weeks. The average duration of follow-up was 18.18 months, ranging from 0.5 to 108 months. Surgical time ranged between 40 and 540 min, with an average of 141 min. The length of stay in days was 12.7, ranging from 1 to 61. The average plate length was ten holes, ranging from 5 to 20 holes. Conclusion: This review aimed to systematically synthesize the available evidence on the risk associated with locked plating osteosynthesis in distal femur fractures. Nonunion is the most common harm and is the primary cause of reoperation. The overall combined risk of a major and critical complication (i.e., requiring reoperation) is approximately 20%.

A Novel Plating System for First Metatarsophalangeal Joint Arthrodesis: A Retrospective Comparison of Hybrid and Traditional Locking Plate Constructs

BACKGROUND

Dorsal plate fixation is commonly used for first metatarsophalangeal joint (1st MTPJ) arthrodesis and plate design continues to evolve. A new staple compression plate (SCP) design attempts to utilize the continuous compression of a nitinol staple across the fusion site while simultaneously providing the stability of a dorsal locked plate. Herein, we compare the radiographic, clinical, and patient-reported outcomes of 1st MTPJ joint arthrodesis using 2 dorsal locking plate constructs including a novel SCP construct.

METHODS

Forty-four patients who underwent 1st MTPJ arthrodesis between 2016 and 2020 were retrospectively evaluated. There were 2 group cohorts. Group 1 cohort included 23 patients who received a CrossRoads Extremity SCP, and Group 2 cohort included 21 patients who received a Stryker dorsal locking precontoured titanium plate (LPP). All patients were evaluated with radiographs, Patient-Reported Outcomes Measures Information System (PROMIS) outcome scores, and Foot Function Index (FFI).

RESULTS

The complication and union rates did not vary between groups with a fusion rate of 95.7% in the SCP group and 90.5 % in the LPP group. Similarly, we found no significant differences in PROMIS or FFI scores between the SCP and LPP plates.

CONCLUSION

Use of either dorsal locking plate construct for 1st MTPJ arthrodesis was associated with high union rates and comparable functional outcomes. As locked plate technology continues to evolve for 1st MTPJ arthrodesis, it is important that clinical outcomes are reported.

LEVELS OF EVIDENCE

Level IV.

Changes in tibial cortical dimensions and density associated with long-term locking plate fixation in goats

PURPOSE

Cortical porosis, secondary to either vascular injury or stress-shielding, is a comorbidity of fracture fixation using compression bone plating. Locking plate constructs have unique mechanics of load transmission and lack of reliance on contact pressures for fixation stability, so secondary cortical porosis adjacent to the plate has not been widely investigated. Therefore, this study aimed to assess the effects of long-term locking plate fixation on cortical dimensions and density in a caprine tibial segmental ostectomy model.

METHODS

Data was acquired from a population of goats enrolled in ongoing orthopedic research which utilized locking plate fixation of 2 cm tibial diaphyseal segmental defects to evaluate bone healing over periods of 3, 6, 9, and 12 months. Quantitative data included tibial cortical width measurements and three-dimensionally reconstructed slab density measurements, both assessed using computed tomographic examinations performed at the time of plate removal. Additional surgical and demographic variables were analyzed for effect on cortical widths and density, and all cis-cortex measurements were compared to both the trans-cortex and to the contralateral limbs.

RESULTS

The tibial cis-cortex was significantly wider and more irregular than the trans-cortex at the same level. This width asymmetry differed in both magnitude and direction from the contralateral limb. The bone underlying the plate was significantly less dense than the trans-cortex, and this cortical density difference was significantly greater than that of the contralateral limb. These cortical changes were independent of both duration of fixation and degree of ostectomy bone healing.

CONCLUSIONS

This study provides evidence that cortical bone loss consistent with cortical porosity is a comorbidity of locking plate fixation in a caprine tibial ostectomy model. Further research is necessary to identify risk factors for locking-plate-associated bone loss and to inform clinical decisions in cases necessitating long-term locking plate fixation.

Spinolaminar locking plates improve fixation strength compared to pedicle screws: a biomechanical analysis

INTRODUCTION

Pedicle screw loosening is a significant complication of posterior spinal fixation, particularly among osteoporotic patients and in deformity constructs. In orthopedic trauma surgery, locking plates and screws have revolutionized the fixation of osteoporotic fractures. We have combined the traumatology principle of fixed-angle locking plate fixation with the spine principles of segmental instrumentation.

METHODS

A novel spinolaminar locking plate was designed based on morphometric studies of human thoracolumbar vertebrae. The plates were fixed to cadaveric human lumbar spines and connected to form 1-level L1-L2 or L4-L5 constructs and compared to similar pedicle screw constructs. Pure moment testing was performed to assess range of motion before and after 30,000 cycles of cyclic fatigue. Post-fatigue fixture pullout strength was assessed by applying a continuous axial tensile force oriented to the principal axis of the pedicle until pullout was observed.

RESULTS

Spinolaminar plate fixation resulted in superior pullout strength compared to pedicle screws (1,065 ± 400N vs. 714 ± 284N, p = 0.028). Spinolaminar plates performed equivalently to pedicle screws in range of motion reduction during flexion/extension and axial rotation. Pedicle screws outperformed the spinolaminar plates in lateral bending. Finally, no spinolaminar constructs failed during cyclic fatigue testing, whereas one pedicle screw construct did.

CONCLUSIONS

The spinolaminar locking plate maintained adequate fixation post-fatigue, particularly in flexion/extension and axial rotation compared to pedicle screws. Moreover, spinolaminar plates were superior to pedicle screw fixation with respect to cyclic fatiguing and pullout strength. The spinolaminar plates offer a viable option for posterior lumbar instrumentation in the adult spine.

Using a Traction Table for Fracture Reduction during Minimally Invasive Plate Osteosynthesis (MIPO) of Distal Femoral Fractures Provides Anatomical Alignment

INTRODUCTION

Fracture reduction and fixation of distal femur fractures are technically demanding. Postoperative malalignment is still commonly reported after minimally invasive plate osteosynthesis (MIPO). We evaluated the postoperative alignment after MIPO using a traction table with a dedicated femoral support.

METHODS

The study included 32 patients aged 65 years or older with distal femur fractures of all AO/OTA types 32 (c) and 33 (except 33 B3 and C3) and peri-implant fractures with stable implants. Internal fixation was achieved with MIPO using a bridge-plating construct. Bilateral computed tomography (CT) scans of the entire femur were performed postoperatively, and measurements of the uninjured contralateral side defined anatomical alignment. Due to incomplete CT scans or excessively distorted femoral anatomy, seven patients were excluded from analyses.

RESULTS

Fracture reduction and fixation on the traction table provided excellent postoperative alignment. Only one of the 25 patients had a rotational malalignment of more than 15° (18°).

CONCLUSIONS

The surgical setup for MIPO of distal femur fractures on a traction table with a dedicated femoral support facilitated reduction and fixation, resulting in a low rate of postoperative malalignment, despite a high rate of peri-implant fractures, and could be recommended for surgical treatment of distal femur fractures.

Biomechanical analysis of a novel Y-plate designed for the treatment of extraarticular distal humerus fractures

Adult distal humerus fractures are infrequent, yet they account for one-third of all humerus fractures. For the treatment of comminuted and osteoporotic fractures, locking plates are claimed to be biomechanically superior to alternative internal fixing techniques. Treatment remains difficult despite recent advancements and the use of locking plates due to frequent comminution, low bone quality, and limited healing ability in osteoporotic bone. An optimal design of the newly constructed plate and the control model were selected. The biomechanical characteristics of non-osteoporotic and osteoporotic synthetic bone were compared on six models. The biomechanical properties of the new plate were tested and compared on 54 osteoporotic synthetic humerus models. The control models were reconstructive and parallel LCPs. The tests were carried out under static and dynamic axial, lateral and bending loads. Fracture displacements were measured by optical measuring system Aramis. The test model is significantly stiffer for lateral load (p = 0.0007) and for bending load at the moment of model failure (p = 0.0002), while for axial load the LCP model showed greater stiffness (p = 0.0017). During lateral dynamic loading, all three LCP models broke and there was a significant difference compared to the test model (p = 0.0125). The LCP model is dynamically significantly more durable under axial load, while the largest displacements were recorded with the test model (p = 0.029). The displacements induced by all three loads are within the limits that fulfil the parameters of appropriate biomechanical stability. A novel locking plate for extra-articular distal humerus fractures may provide an alternative to the traditional two-plate.

In vitro analysis and in vivo assessment of fracture complications associated with use of locking plate constructs for stabilization of caprine tibial segmental defects

PURPOSE

Locking plate fixation of caprine tibial segmental defects is widely utilized for translational modeling of human osteopathology, and it is a useful research model in tissue engineering and orthopedic biomaterials research due to its inherent stability while maintaining unobstructed visualization of the gap defect and associated healing. However, research regarding surgical technique and long-term complications associated with this fixation method are lacking. The goal of this study was to assess the effects of surgeon-selected factors including locking plate length, plate positioning, and relative extent of tibial coverage on fixation failure, in the form of postoperative fracture.

METHODS

In vitro, the effect of plate length was evaluated using single cycle compressive load to failure mechanical testing of locking plate fixations of caprine tibial gap defects. In vivo, effects of plate length, positioning, and relative tibial coverage were evaluated using data from a population of goats enrolled in ongoing orthopedic research which utilized locking plate fixation of 2 cm tibial diaphyseal segmental defects to evaluate bone healing over 3, 6, 9, and 12 months.

RESULTS

In vitro, no significant differences in maximum compressive load or total strain were noted between fixations using 14 cm locking plates and 18 cm locking plates. In vivo, both plate length and tibial coverage ratio were significantly associated with postoperative fixation failure. The incidence of any cortical fracture in goats stabilized with a 14 cm plate was 57%, as compared with 3% in goats stabilized with an 18 cm plate. Craniocaudal and mediolateral angular positioning variables were not significantly associated with fixation failure. Decreasing distance between the gap defect and the proximal screw of the distal bone segment was associated with increased incidence of fracture, suggesting an effect on proximodistal positioning on overall fixation stability.

CONCLUSIONS

This study emphasizes the differences between in vitro modeling and in vivo application of surgical fixation methods, and, based on the in vivo results, maximization of plate-to-tibia coverage is recommended when using locking plate fixation of the goat tibial segmental defect as a model in orthopedic research.

Comparison of Complications, Metalwork Removal and Cost Between Locking and Tubular Plates for Lateral Malleolus Fractures Fixation

Introduction Ankle fractures are common injuries in orthopaedic practice. Open reduction with internal fixation is the main line of management of displaced ankle fractures in fit patients. The study aims to analyse the complications, re-operation rate and cost difference between one-third tubular and locking plates which are the most frequently used constructs in lateral malleolus fractures. Materials and methods The total number of presented ankle fractures from April to August during the years 2015, 2017 and 2019 to our Tertiary Hospital in the United Kingdom were screened. Data including operative fixation, plate used, complication rates, the need for revision surgery and metalwork removal were collected from the hospital's electronic Virtual Trauma Board. Patients who had less than one-year follow-up were excluded. Results A total of 174 patients were included which represents more than half of presented ankle fractures (56%) with a decline in the mean age of operated patients from 56.4 in 2015 to 46.2 in 2019. The majority of fixation used tubular plates (n=122) versus (n=52) for locking plates. Locking plate fixation doubled from 10 in 2015 to 23 in 2019. However, they only contributed to 27% of the total operated ankle fractures. Despite the initial higher complications and removal rates of locking plates in 2015 (P<0.042 and P<0.038 respectively), there was no significant difference in overall complications, revision rates, and metalwork removal between locking plates and tubular plates (p=0.084, FEp= 0.158 and p=0.096 respectively). There was an estimated extra cost of £15938.60 for the use of locking plates during the study timeline. Conclusion There was no significant difference in overall complications, revision surgery and metalwork removal between tubular and locking plates in treating lateral malleolus fractures despite the significantly higher cost of locking constructs. Further studies are needed to illustrate the trend and cost-effective analysis of the tubular and locking plates in treating ankle fractures.

Augmented osteosynthesis in fragility fracture

Due to poor bone quality and complexity, some fractures are difficult to treat, with high risk of failure. Moreover, general health is often poor in elderly patients with multiple comorbidity and poor compliance, necessitating perfect first-line management to avoid re-operation. The armamentarium comprises specific internal fixation implants and also complementary methods such as autologous, homologous or heterologous bone graft or bone substitutes with varying mechanical and biological characteristics. Associating these options is what is mean by "augmented fixation". The present review of augmented osteosynthesis addresses the following questions: What are the characteristics of fragility fractures? Fragility fracture is caused by low-energy trauma on bone with poor structural quality and low mineral density. Treatment aims to enable early mobilization and weight-bearing while avoiding mechanical failure of fixation. Prolonged bedrest, loss of mobility and surgical revision are aggravating and sometimes fatal factors in these fragile patients. What are the biological techniques of fixation augmentation in fragility fracture? Autologous or homologous bone graft are the most widely used biological augmentation techniques. They fill spaces and promote osteoconduction and consolidation. Some bone-like phosphocalcic structures are opening up promising lines of research. What are the non-biological techniques of fixation augmentation in fragility fracture? Hydroxyapatite, phosphocalcic cement and acrylic cement are the most widely used synthetic materials. Biological and mechanical effects are variable according to composition, requiring specific implementation. What are the mechanical techniques of fixation augmentation in fragility fracture? There is at present no consensus as to the augmentation techniques to be applied in fragility fracture. Cerclage or complementary plating, or external fixation associated to internal fixation are possibilities. However, the literature consists only of small series reporting surgical techniques specific to a given surgeon or team. When and how should osteosynthesis for fragility fracture be augmented? The choice of augmentation depends on fracture location, comminution, available material and local experience. The more severe the fracture, the more complex the fixation. The approach needs to be adapted to the preoperative planning and the associated mechanical means (plate, complementary cerclage) and prosthetic replacement should be considered in certain joint fractures or fractures close to load-bearing surfaces. LEVEL OF EVIDENCE: V; expert opinion.

No clinical advantage of locking over nonlocking plate fixation of symphyseal disruptions

PURPOSE

although locking plates have led to important changes in fracture management, becoming important tools in the orthopedic surgeon's arsenal, the benefits of locking plates for traumatic diastasis of the pubic symphysis have not been established. This study was conducted to assess the quality of life in its different domains among patients with traumatic diastasis of the pubic symphysis managed either with locking or nonlocking plate.

METHODS

a prospective cohort study was undertaken at 3 level 1 trauma centres in Brazil. Patients presenting traumatic diastasis of the pubic symphysis treated with plate fixation with a minimum follow-up of 12 months were eligible for inclusion. Through a Pfannenstiel approach, the pubic symphysis was reduced and fixed with a superiorly positioned 4.5mm four to six hole reconstruction locked plate or 3.5mm four to six hole reconstruction nonlocked plate. Posterior injury was managed during the same procedure. Outcome measures were adequate healing of the pelvic injuries, return to pre-injury level on daily activities, and quality of life at the last follow-up visit. Complications and modes of failure were summarized and reviewed. Bivariate linear regression was used to assess individual factors affecting patients' health-related quality of life. A p value of <5% was considered significant.

RESULTS

a total of 31 adult patients (29 males and 2 females) were eligible for the study. Thirteen patients were managed with a reconstruction locked plate and 18 patients with a nonlocked reconstruction plate. Average postoperative follow-up time was 24 months. Adequate healing of the pelvic injuries was achieved in 61.5% of patients treated with locking plates and 94.4% of patients treated with nonlocking plates (p=0.003). Radiographic failure of fixation with minor complications occurred in 46.1% of patients after locked plating versus 11.1% of patients in the nonlocking plate group (p=0.0003). In bivariate analysis, abnormal gait (p=0.007) was associated with a reduced long-term quality of life as measured with the EQ-5D-3L.

CONCLUSION

internal fixation of traumatic diastasis of the pubic symphysis with locking plates has no clinical advantage when compared to nonlocked plating. Mechanical failure and inadequate healing are significantly increased after locked plating of the pubic symphysis. Therefore, we do not recommend routine use of locking plates for managing patients presenting traumatic diastasis of the pubic symphysis.

LEVEL OF EVIDENCE

II (prospective, cohort study).

Biomechanics of Osteoporotic Fracture Care: Advances in Locking Plate and Intramedullary Nail Technology

Osteoporotic fractures are extremely common and will continue to increase. Methods of internal fixation must address challenges presented by architectural changes of weakened bone. The goals of surgery are to provide mechanically stable internal fixation with minimal biologic insult that provides rapid rehabilitation and early mobilization. Novel techniques and technology that reinforce preservation of periosteal blood supply and utilization of biomechanically stable constructs diminish failure rates. Advents in locking plate technology, intramedullary nail designs, bone augmentation, and multiple implant constructs maximize strength while mitigating axial, torsional, and bending failure modes to provide optimal patient outcomes.

Efficacy of Hemiarthroplasty vs. Locking Plate Fixation for Proximal Humerus Fractures: A Meta-Analysis

Background: Proximal humerus fractures are common in a clinic and account for ~6% of all adult fractures. Hemiarthroplasty (HA) or locking plate (LP) fixation is currently recommended for the treatment of complex proximal humerus fractures (PHFs); however, there is no uniform standard for optimal surgical treatment or functional recovery. We conducted a meta-analysis to compare the efficacy of LP and HA in the treatment of PHFs. Methods: Relative studies associated with HA and LP were searched in December 2020 in the PubMed, Embase, Cochrane Library, and OVID databases. The quality of the studies, functional outcomes (including the Constant-Murley score (CMS), American Shoulder and Elbow Surgeons Score (ASES), Simple Shoulder Test (SST), Short Form Health Survey (SF-12v2), complications, and reoperation rate were extracted and analyzed with the Stata 14.0 software. Results: A total of 958 patients from 12 studies were included in the meta-analysis, which showed that patients treated with LP had a significantly lower reoperation rate, a higher complication rate, and a higher CMS score than those treated with HA. There were no significant differences in ASES, SST, or SF-12v2 scores between treatment groups. Conclusions: Compared with HA, LP exhibited better clinical efficacy in some aspects. However, large sample and randomized, controlled studies are needed for further validation.

The influence of the number of holes in the open wedge high tibial osteotomy on knee biomechanics using finite element analysis

BACKGROUND

The most significant differences of high tibial osteotomy (HTO) were found in terms of plate length, and this was related to number of holes distal region of the plate below wedge. The purpose of this study is to evaluate the biomechanical effects of three different designs medial opening wedge plates.

HYPOTHESIS

The design of the HTO plate influenced the outcome of the biomechanics.

METHODS

The HTO model was simulated using finite element (FE) model. This FE investigation included three types of loading conditions corresponding to the loads used in the experimental study for model validation and model predictions for clinically relevant loading scenarios. The average stress and contact stress were evaluated.

RESULTS

The highest average stress was observed in the TomoFix. Conversely, the stress on the bone declined in the order of Puddu, Maxi and TomoFix plates. The micromotion in the wedge displayed a similar trend to the stress on bone. The highest and lowest contact stresses on the medial meniscus were observed in the Puddu and TomoFix plate, respectively. However, an opposite trend was observed in the lateral meniscus. The contact stress on medial and lateral menisci decreased and increased, respectively, in all three different plates when compared to those in the intact model.

DISCUSSION

The TomoFix plate exhibited the highest stability relative to the micromotions of the wedge. However, in terms of the stress on the bone and plates, a stress-shielding effect could exist in the TomoFix plate. Additionally, the contact stress on the articular surface suggested that a complicated relationship could exist with respect to the plate design.

LEVEL OF EVIDENCE

IV.

Case Report: Locking Plate for Cubitus Varus Correction in a 7-Year-Old Girl With Osteogenesis Imperfecta

Background: Cubitus varus deformity is a common complication of untreated elbow fractures in children. However, cubitus varus in osteogenesis imperfecta (OI) children is a rare but challenging situation. To the author's knowledge, this is the first study discussing the correction of cubitus varus deformity in patient with OI. Case Presentation: Here we report a case of a 7-year-old OI girl with cubitus varus deformity due to a supracondylar fracture of humerus 3 year ago. The patient's parent gave a history of supracondylar fracture of left humerus in 2015. Without medical intervention, the patient was admitted into our institution for corrective surgery with the diagnosis of osteogenesis imperfecta and cubitus varus deformity in the left arm. Result: Medications including calcium, vitamin D and bisphosphonates were administered before the corrective surgery of cubitus varus, and a single locking plate was used to fixate the osteotomy. After the surgery, the appearance and range of motion (ROM) of the left arm was almost normal. Combined with gradual rehabilitation, the ROM of the left arm was normal without pain during daily use within the 1-year follow up. The hardware was removed as the nailing of the forearm fractures was performed at the same time. In the latest follow-up in September 2021, the appearance and ROM of the left arm was normal. Conclusion: Cubitus varus is a common deformity in children with elbow injuries, but it presents a challenging situation in compound fractures in OI patients. Locking plate combined with meticulous pharmacological intervention provides a good option for corrective surgery of cubitus varus in patients with OI.

ESTES recommendations on proximal humerus fractures in the elderly

PURPOSE

The section for the skeletal trauma and sport's injuries of the European Society for Trauma and Emergency Surgery (ESTES) appointed a task force group to reach a consensus among European countries on proximal humeral fractures.

MATERIAL/METHODS

The task force group organized several consensus meetings until a paper with final recommendations was confirmed during the ESTES Executive Board meeting in Berlin on 25 October 2018.

CONCLUSION

The Recommendations compare conservative and four possible operative treatment options (ORIF, nailing, hemi- and total reverse arthroplasty) and enable the smallest common denominator for the surgical treatment among ESTES members.

Unidirectional Porous β-Tricalcium Phosphate: A New Bone Filling Substitute for Treatment of Distal Radius Fracture in the Elderly Population

Background: A new beta-tricalcium phosphate with unidirectional pore structure (UDPTCP), Affinos^® (Kurray, Okayama, Japan), has been in clinical use since 2015. To date, there have been only a few clinical studies using this material. We report here the first clinical study for distal radial fracture in the elderly population treated with UDPTCP. Methods: Consecutive patients aged 65 years or older with dorsally displaced unstable fracture of the distal radius (n = 36) were treated operatively in our department. Following reduction of the fracture site, a 7 mm size cube of UDPTCP was placed in the gap of the bony defect and the fracture stabilized with mono-axial or poly-axial type locking plates and screws. Remodeling of the UDPTCP was evaluated by plain radiograph and clinical outcomes were also assessed. Results: UDPTCP was significantly resorbed at 2 months after surgery, both at the center and periphery of the material. Complications were only observed in the post-operative period. Significant correction loss of radial alignment was seen in patients stabilized with poly-axial locking plate. The clinical outcome in all cases was excellent. Conclusions: Block UDPTCP is a safe and convenient material for the treatment of distal radius fracture and is replaced within a suitable time period after grafting into the fracture site. UDPTCP and stable internal fixation is therefore a reliable strategy for restoring and preserving anatomical position, especially in the elderly population.

A comparison of bone union and complication rates between locking and non-locking plates in distal fibular fracture: Retrospective study of 106 cases

BACKGROUND

Ankle fractures represents the third most frequent fracture in elderly patients. There is a current tendency to fix long bones fractures with locking plates. However, we rarely find published accounts about the use of locking plates in distal fibula fractures, except for biomechanical ones, studying human cadaveric fibula.

OBJECTIVES

The main objective was to compare radiographic bone union rates at 6 and 12 weeks of follow up, then wound complications and hardware removal rates, and construct cost.

STUDY DESIGN & METHODS

We retrospectively analyzed 105 patients who underwent surgery with locking plates or non-locking plates over a two-year period, out of which 42 patients were treated with non-locking plates (VIVES™ - Stryker^Ⓡ) and 63 with locking plates (VariAx™ - Stryker^Ⓡ,). We analyzed bone union on anterior posterior and lateral X-rays of the ankle. We collected data of wound complications and hardware removal from patient records. Multiple linear regression techniques were performed after identifying dependent variables.

RESULTS

There was no significant difference between non-locking and locking plates in the radiographic bone union rate of distal fibula, respectively at 6 and 12 post-operative weeks (85.71% vs. 81%; p = 0.525 and 97.62% vs. 96.83%; p = 1). No significant difference was found in the wound complication rate between the two groups (11.9% vs. 11.12%; p = 0.9). No significant differences were found in the hardware removal rate, either with or without operative site's infection (respectively: 30.95% vs. 39.68%; p = 0.361 and 21.42% vs. 38.09%; p = 0.071). Cost efficiency is in the favor of non-locking plates.

CONCLUSION

Non-locking constructs are as effective as locking constructs in the treatment of displaced distal fibula fractures at a substantially lower cost. High-quality randomized controlled trials are needed in the future to verify the finding of this study.

Bench-to-bedside strategies for osteoporotic fracture: From osteoimmunology to mechanosensation

Osteoporosis is characterized by a decrease in bone mass and strength, rendering people prone to osteoporotic fractures caused by low-energy forces. The primary treatment strategy for osteoporotic fractures is surgery; however, the compromised and comminuted bones in osteoporotic fracture sites are not conducive to optimum reduction and rigid fixation. In addition, these patients always exhibit accompanying aging-related disorders, including high inflammatory status, decreased mechanical loading and abnormal skeletal metabolism, which are disadvantages for fracture healing around sites that have undergone orthopedic procedures. Since the incidence of osteoporosis is expected to increase worldwide, orthopedic surgeons should pay more attention to comprehensive strategies for improving the poor prognosis of osteoporotic fractures. Herein, we highlight the molecular basis of osteoimmunology and bone mechanosensation in different healing phases of elderly osteoporotic fractures, guiding perioperative management to alleviate the unfavorable effects of insufficient mechanical loading, high inflammatory levels and pathogen infection. The well-informed pharmacologic and surgical intervention, including treatment with anti-inflammatory drugs and sufficient application of antibiotics, as well as bench-to-bedside strategies for bone augmentation and hardware selection, should be made according to a comprehensive understanding of bone biomechanical properties in addition to the remodeling status of osteoporotic bones, which is necessary for creating proper biological and mechanical environments for bone union and remodeling. Multidisciplinary collaboration will facilitate the improvement of overall osteoporotic care and reduction of secondary fracture incidence.

[Operative treatment in orthopedics and trauma surgery : Are more operations carried out in Germany?]

BACKGROUND

Since 2005, when the Diagnosis-Related Group (DRG) system was introduced, an increasing number of surgical procedures have been reported in Germany. In particular, the numbers of elective arthroplasty and spinal surgery procedures have been controversial.

OBJECTIVES

The focus of this study was analyzing the development of spinal surgery, arthroplasty, and fracture management.

MATERIALS AND METHODS

We analyzed the database for all musculoskeletal operating procedure codes (OPS codes 5‑78 to 5‑86) from 2005 to 2013 collected by the German Federal Statistical Office.

RESULTS

With an increase in total patient numbers of 12.8%, there was a rise in in-patient musculoskeletal procedures of 43.5%; the highest increase in procedures was found in spinal surgery (130%). Despite an ageing population, the numbers of hip- and knee arthroplasty procedures initially decreased after 2011 and after 2009 respectively. The number of osteosyntheses showed a slight increase (16%), whereas the number of (elective) implant removals declined (-7%). An increase in novel techniques was noticeable, such as locked plate osteosynthesis (251%), shoulder arthroplasty (402%) or the use of bone substitutes in spinal surgery (+2,011%).

CONCLUSIONS

Despite generally increasing volume growth, the numbers of hip and knee arthroplasty cases decreased. In addition to an ageing population and potential economic incentives, technical innovations and new implant systems should be considered when discussing increasing case numbers.

The impact of plate length, fibula integrity and plate placement on tibial shaft fixation stability: a finite element study

BACKGROUND

Tibial shaft fractures account for approximately 15% of long bone fractures. Locked plates with minimally invasive plate osteosynthesis techniques are used widely by surgeons. The purpose of this study is to investigate the impact of factors meaning the plate length, fibula integrity, and placement of the plate on the stability of tibial shaft fracture fixation.

METHODS

A finite element model of the tibial shaft fracture was built. An axial force of 2500 N was applied to simulate the axial compressive load on an adult knee during single-limb stance. The equivalent von Mises stress and displacement of the fractured ends were used as the output measures.

RESULTS

In models with plates on the lateral side of the tibia, displacement in models fixed with a 12-hole plate showed the smallest value. In models with plates on the medial side of the tibia, displacement in models fixed with 14-hole plate showed the smallest value. The peak stress of plates implanted on the medial side of the tibia was higher than that of plates on the lateral side. The peak stress and the displacement of models involved with the fibula were lower than that of models without fibula, regardless of the length or location of plates.

CONCLUSIONS

For models with plates on the medial side of the tibia, the 14-hole plate is the best choice in terms of stability. While for models with plates on the lateral side of the tibia, the 12-hole plate demonstrated the optimal biomechanical stability. The integrity of the fibula improves the anti-vertical compression stability of the construct. The peak stress of plates implanted on the medial side of the tibia was higher than that of plates on the lateral side, which indicated that the construct with medially implanted plate has a higher risk of implant failure.

Outcomes of operative and nonoperative treatment of 3- and 4-part proximal humeral fractures in elderly: a 10-year retrospective cohort study

Purpose

Despite a rising incidence in proximal humeral fractures, there is still no evidence for the best treatment option, especially for elderly patients. The aim of this retrospective cohort study was to evaluate health-related quality of life (HRQoL), functional outcome, pain and social participation in elderly patients, after operative and nonoperative treatment of displaced 3- and 4-part proximal humeral fractures.

Methods

150 patients aged ≥ 65, treated for a displaced 3- or 4-part proximal humeral fracture between 2004 and 2014, were invited to participate. Eventually 91 patients (61%) participated, of which 32 non-operatively treated patients were matched to 32 of the 59 operatively treated patients by propensity score matching. The EQ-5D, DASH, VAS for pain and WHODAS 2.0 Participation in Society domain were administered. Complications and reinterventions were registered.

Results

No significant difference was found between the two treatment groups in HRQoL (p = 0.43), function (p = 0.78) and pain (p = 0.19). A trend toward better social participation in the operative group (p = 0.09) was found. More complications and reinterventions occurred in the operative group than the nonoperative group, with 9 versus 5 complications (p = 0.37) and 8 versus 2 reinterventions (p = 0.08).

Conclusions

In this study, we found no evidence of a difference in HRQoL, functional outcome or pain 1–10 years after operative or nonoperative treatment in patients of 65 and older with a displaced 3- or 4-part humeral fracture. Operatively treated patients showed a trend toward better social participation but also higher reintervention rates.

Risk factors for tibial tuberosity fracture after tibial tuberosity advancement in dogs

Objective: To retrospectively identify factors that predispose to tibial tuberosity (TT) fracture after tibial tuberosity advancement (TTA) in dogs.

Methods: The medical records and radio-graphs of a group of control dogs (n = 212) that had TTA surgery (n = 241 procedures) and did not sustain a fracture between 2008 and 2013, and those of 12 dogs that did sustain a fracture (n = 13 procedures) between 2008 and 2013 at two veterinary teaching hospitals were evaluated to determine the effect of signalment, body weight and surgical inaccuracies on TT fracture. Multivariable logistic regression was performed with the occurrence of TT fracture as the outcome variable of interest.

Results: Signalment and body weight were not found to be associated with TT fracture. Of the surgical inaccuracies, osteotomy shape (p = 0.003), plate position (p = 0.009), and cage position (p = 0.039) were factors significantly associated with TT fracture.

Clinical significance: This study provides data to support the hypothesis that poor plate position, poor cage position, and narrow distal osteotomy width are associated with TT fracture after TTA. We conclude that it is of paramount importance to pay careful attention to surgical technique in order to reduce this risk.

Surgical treatment of osteoporotic fractures: An update on the principles of management

The treatment of osteoporotic fractures continues to challenge orthopedic surgeon. The fragility of the underlying bone in conjunction with the need for specific implants led to the development of explicit surgical techniques in order to minimize implant failure related complications, morbidity and mortality. From the patient's perspective, the existence of frailty, dementia and other medical related co-morbidities induce a complex situation necessitating high vigilance during the perioperative and post-operative period. This update reviews current principles and techniques essential to successful surgical treatment of these injuries.

Locking versus non-locking one-third tubular plates for treating osteoporotic distal fibula fractures: a comparative study

INTRODUCTION

Ankle fractures represent the third most common fracture in elderly patients, after hip and wrist fractures. Distal fibula fractures in this population are closely related to osteoporosis, which renders commonly used methods of internal fixation technically demanding and prone to failure. Currently there is a tendency to fix osteoporotic metaphyseal and epiphyseal fractures with locking plates. However, published accounts about the use of this technology in osteoporotic distal fibula fractures are scarce. In this study we compare the results of two groups of patients who underwent surgery for these types of fracture, one group received locking and the other non-locking screws, both using one-third tubular plates.

METHODS

Sixty-two patients, aged over 64 years, underwent surgery for osteoporotic distal fibula fractures between 2011 and 2014. Forty-five of them were stabilized with a non-locking plate and the remaining 17 with a locking plate fixation. Follow-up was performed at 4, 8, 12, 26, and 52 weeks. Results were assessed according to the AOFAS Ankle-Hindfoot Score and radiological criteria for consolidation.

RESULTS

Average time to union and AOFAS scores at 6 and 12 months were similar in both groups, including for the individual categories: function, pain, mobility, and alignment. Only time until partial weight bearing was significantly lower in the locking plate group (4.69 ± 2.63 vs 7.77 ± 4.30, p = 0.03). The most common complications were wound dehiscence and superficial infection (two cases of both).

CONCLUSIONS

Both locking and conventional non-locking plates achieved similar treatment outcomes in this group of osteoporotic patients aged over 64. However, locking plates may offer more benefits in cases that have to take into account immobilization time and concomitant soft-tissue damage.

Operative Treatment of 2-Part Surgical Neck Fracture of the Humerus: Intramedullary Nail Versus Locking Compression Plate With Technical Consideration

OBJECTIVE

To compare the outcomes of patients who underwent either open reduction internal fixation with a locking plate and screws or closed reduction internal fixation with an antegrade intramedullary nail (IMN) for displaced surgical neck fracture of the humerus.

DESIGN

Retrospective comparative study.

SETTING

Single institute, Level-I academic trauma center.

PATIENTS AND INTERVENTION

Sixty-nine patients with 2-part surgical neck fracture of the humerus underwent either an IMN (38 patients group A) or a locked plate fixation (31 patients group B).

OUTCOMES MEASUREMENT

Pain on a visual analog scale, University of California Los Angeles (UCLA) Shoulder Score, American Shoulder and Elbow Surgeons (ASES) score, and active range of motion (ROM).

RESULTS

At the 2-year follow-up, there were no significant differences in the visual analog scale pain score (1.3 in group A; 0.9 in group B), ASES score (90.2 in group A; 91.9 in group B), and UCLA Shoulder Score (30.7 in group A; 31.8 in group B) between groups. Active ROM did not differ significantly between groups. There were 3 complications in the IMN group, 1 nonunion requiring autogenous iliac crest bone graft, and 2 cases of screw loosening.

CONCLUSIONS

For displaced surgical neck fractures of the humerus, both IM nailing and locked plate fixation in patients yielded satisfactory outcomes at the 2-year follow-up with no significant differences in pain or ROM between groups.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Partial proximal tibia fractures

Partial tibial plateau fractures may occur as a consequence of either valgus or varus trauma combined with a rotational and axial compression component.

High-energy trauma may result in a more complex and multi-fragmented fracture pattern, which occurs predominantly in young people. Conversely, a low-energy mechanism may lead to a pure depression fracture in the older population with weaker bone density.

Pre-operative classification of these fractures, by Müller AO, Schatzker or novel CT-based methods, helps to understand the fracture pattern and choose the surgical approach and treatment strategy in accordance with estimated bone mineral density and the individual history of each patient.

Non-operative treatment may be considered for non-displaced intra-articular fractures of the lateral tibial condyle. Intra-articular joint displacement ⩾ 2 mm, open fractures or fractures of the medial condyle should be reduced and fixed operatively. Autologous, allogenic and synthetic bone substitutes can be used to fill bone defects.

A variety of minimally invasive approaches, temporary osteotomies and novel techniques (e.g. arthroscopically assisted reduction or ‘jail-type’ screw osteosynthesis) offer a range of choices for the individual and are potentially less invasive treatments.

Rehabilitation protocols should be carefully planned according to the degree of stability achieved by internal fixation, bone mineral density and other patient-specific factors (age, compliance, mobility). To avoid stiffness, early functional mobilisation plays a major role in rehabilitation. In the elderly, low-energy trauma and impression fractures are indicators for the further screening and treatment of osteoporosis.

Cite this article: EFORT Open Rev 2017;2. DOI: 10.1302/2058-5241.2.160067. Originally published online at www.efortopenreviews.org

Distal fibula fracture fixation: Biomechanical evaluation of three different fixation implants

BACKGROUND

The goal of this study was to evaluate the biomechanical performance of three distal fibula fracture fixation implants in a matched pair cadaveric fibula model: (1) a 5-hole compression plate with lag screw, (2) a 5-hole locking plate with lag screw, and (3) the 6-hole tabbed-plate with locking screws.

METHODS

Three-dimensional motions between the proximal and distal fibular segments were measured under cyclic valgus bending, cyclic compressive axial loading, and cyclic torsional external-rotation loading. During loading, strains were measured on the surfaces of each fibula near the simulated fracture site, and on the plate, to assess load transfer. Bone quality was quantified globally for each donor using bone mineral density (BMD) measured using Dual X-ray absorptiometry (DEXA) and locally at the fracture site using bone mineral content (BMC) measured using peripheral quantitative computed tomography (pQCT).

RESULTS

Mean failure loads were below 0.2Nm of valgus bending and below 4Nm of external-rotational torque. Mean failure angulation was below 1degree for valgus bending, and failure rotation was below 7degrees for external-rotation. In the compression plate group, significant correlations were observed between bone quality (global BMD and local BMC) and strain in every one of the five locations (Pearson correlation coefficients >0.95, p<0.05). In contrast, in the locking and tabbed-plate groups, BMD and BMC correlated with far fewer strain locations.

CONCLUSIONS

Overall, the tabbed-plate had similar construct stability and strength to the compression and locking plates. However, the distribution of load with the locking and tabbed-plates was not as heavily dependent on bone quality.

The biomechanical cost of variable angle locking screws

INTRODUCTION

Variable angle (VA) locking plates in fracture fixation surgery allow screws to be fastened to the plate within a conical "locus of vectors" in order to avoid existing prostheses, joint surfaces, or poor quality bone. Clinical failures of VA constructs in which screws have rotated at the plate/screw interface have been reported raising the concern that there may be a biomechanical cost for the increased flexibility that VA provides. The objective of this study was to test the mechanical properties of one commonly used VA locking mechanism with screws placed in both nominal and off-axis trajectories and compare these against the standard locking mechanism.

METHODS

VA locking screws were inserted into plates for distal femur fractures (VA Curved Condylar) at various angles (0° to 15° away from perpendicular). A control group of standard locking screws/plates was also tested. Maximum moment at the screw/plate interface and moment at two reference displacements were determined.

RESULTS

VA screws locked perpendicular to the plate provided the greatest maximum moment and moment at the reference displacements when using the VA system, and demonstrated lower moments compared to standard locking screws/plates (p<0.001). Based on linear regression, there was an average decrease of approximately 0.4 Nm screw-plate interface strength for every 1° increase in screw-plate angle (p<0.001). Decreases (p<0.05) were discovered in both maximum moment and moment at the reference displacements for screws locked at 5° relative to those locked at 0°, 10° relative to 0°, and 15° relative to 10°.

DISCUSSION

Standard locking systems provided greater resistance to rotational failure at the screw/plate interface than variable angle locking systems. Variable angle systems provided the greatest resistance to rotation when the screw was inserted perpendicular to the plate. As the off-axis angle increased, the resistance to rotation at the screw/plate interface decreased almost linearly. It is unknown if these differences are clinically significant in an actual fracture construct, but recent reported failures in the distal femur suggest that they might be.

CONCLUSION

Surgeons should weigh the risks and benefits of VA systems and attempt to minimize the off-axis angle magnitude when VA systems are selected.

Failure of fracture fixation in osteoporotic bone

This manuscript will provide an overview of how the age and osteoporosis related changes in mechanical properties of bone affect the stability of osteosynthesis constructs, both from a mechanical as well as from a clinical perspective. The manuscript will also address some of the principles of fracture fixation for osteoporotic fractures and discuss applications of osteoporotic fracture fixation at sites typically affected by fragility fractures, namely the distal radius, the proximal humerus, the femur and the spine. The primary aim of operative treatment in elderly individuals is the avoidance of immobilization of the patient. In selected cases conservative treatment might be required. Generally, choice of treatment should be individualized and based on the evaluation of patient-specific, fracture-specific and surgeon-specific aspects. The orthopaedic surgeon plays an essential role in enabling functional recovery by providing good surgery but a multidisciplinary approach is essential in order to support the patient to regain his/her quality of life after fragility fracture. Overall, the therapy of fractures in osteoporotic bone in the elderly requires a multidisciplinary therapeutic acute care concept including treatment of co-morbidities and correct choice of timing, and technique of the operative intervention.

Comparison of intramedullary fibular allograft with locking compression plate versus shoulder hemi-arthroplasty for repair of osteoporotic four-part proximal humerus fracture: Consecutive, prospective, controlled, and comparative study

OBJECTIVES

To compare the outcomes of intramedullary fibular allograft (IFA) with locking compression plates (LCPs) versus shoulder hemi-arthroplasty (HA) in osteoporotic four-part proximal humeral fracture (PHF).

METHODS

Between January 2010 and December 2012, totally 60 cases with osteoporotic four-part PHF were enrolled in this study and were randomly separated into IFA and LCPs group and HA group (n=30). Additionally, surgery indexes for patients in the two groups, such as Constant-Murley score (CMS), the Disability of Arm, Shoulder and Hand (DASH) score, individual subject evaluation of the outcomes, plain X-ray, and computer tomography (CT) scanning were evaluated and compared.

RESULTS

CMS, DASH score, activities of daily living (ADL), and range of motion (ROM) were statistically higher in the IFA and LCPs group than those in the HA group at the last follow-up, whereas the pain were obviously lower than that in the HA group. Besides, patients in the IFA and LCPs group had higher abduction, external rotation with elbow, strength, and satisfactory rating compared with HA group at the last follow-up. However, one case developed avascular necrosis (AVN), one case encountered screw perforation, and one case experienced varus displacement in the IFA and LCPs group, while there were 2, 4, and 2 cases suffered from superficial infection, shoulder stiffness, tuberosity migration in the HA group, respectively.

CONCLUSION

IFA with LCP have an advantage in functional outcomes than shoulder HA.

LEVEL OF EVIDENCE

Level II. Prospective cohort study.

Intraoperative mechanical measurement of bone quality with the DensiProbe

Reduced bone stock can result in fractures that mostly occur in the spine, distal radius, and proximal femur. In case of operative treatment, osteoporosis is associated with an increased failure rate. To estimate implant anchorage, mechanical methods seem to be promising to measure bone strength intraoperatively. It has been shown that the mechanical peak torque correlates with the local bone mineral density and screw failure load in hip, hindfoot, humerus, and spine in vitro. One device to measure mechanical peak torque is the DensiProbe (AO Research Institute, Davos, Switzerland). The device has shown its effectiveness in mechanical peak torque measurement in mechanical testing setups for the use in hip, hindfoot, and spine. In all studies, the correlation of mechanical torque measurement and local bone mineral density and screw failure load could be shown. It allows the surgeon to judge local bone strength intraoperatively directly at the region of interest and gives valuable information if additional augmentation is needed. We summarize methods of this new technique, its advantages and limitations, and give an overview of actual and possible future applications.

Stability of unicortical locked fixation versus bicortical non-locked fixation for forearm fractures

Locking plate fixation is being widely applied for fixation of forearm fractures and has many potential advantages, such as fixed angle fixation and improved construct stability, especially in osteoporotic bone. Biomechanical data comparing locking devices to commonly used Low Contact Dynamic Compression (LCDCP) plates for the fixation of forearm fractures has been lacking. The purpose of this study was to compare the fixation stability of a 3.5-mm unicortical locked plate with bicortical non-locked LCDCP plates. Six matched pairs of fresh frozen cadaveric forearms were randomly assigned to unicortical locked and bicortical unlocked groups. Non-destructive four-point bending and torsional test was performed on the ulna and radius separately, using a servohydraulic testing system to obtain construct stiffness of the intact specimens and specimens after osteotomy and plating. The specimens were then loaded to failure to test the fixation strength. The locked unicortical fixation showed significantly higher bending stiffness than the unlocked bicortical fixation, but with significantly lower stiffness and strength in torsion. Fixation strength was comparable between the two groups under bending, but significantly greater in the bicortical non-locked group under torsion. Findings from this study suggest that postoperative rehabilitation protocols may need modification to limit torsional loading in the early stage when using locked unicortical fixation. The study also points out the potential advantage of a hybrid fixation that combines locked unicortical and unlocked bicortical screws.

Bone properties of the humeral head and resistance to screw cutout

Surgical treatment of fractures involving the proximal humeral head is hampered by complications. Screw cutout is the major pitfall seen in connection with rigid plating. We have exploited a bony explanation for this phenomenon.

Plate on plate osteosynthesis for the treatment of nonhealed periplate fractures

Purpose. The purpose of this paper is to present our technique for the treatment of periplate fractures. Methods. From 2009 to 2012 we treated three patients. In all cases the existing plate was left and the new one placed over the existing. Locking screws were placed through both plates. The other screws in the new plate were used as best suited the fracture. Results. In all cases less than 6 months had passed between fractures. None of the original fractures had healed. Mean followup was 2 years. All fractures proceeded to union within 7 months. No complications were recorded. All the patients returned to their normal activities and were satisfied with the results of their treatment. Conclusion. Our plate on plate technique is effective for the treatment of periplate fractures. A solid fusion can be achieved at the new fracture site without disturbing the previous fixation.

[Mono- versus polyaxial locking plates]

Conventional plate osteosynthesis is undergoing a period of transition. The concept of locking plate osteosynthesis is of special importance. Monoaxial locking plate osteosynthesis has shown promising results (rapid bone healing via callus, minimal soft tissue irritation, advantageous in osteoporosis). Some implants allow for polyaxial locking. The first results of comparative studies concerning biomechanics and clinical outcome of mono- versus polyaxial locking plates are presented.

The effect of interlocking parallel screws in subcapital femoral-neck fracture fixation: a cadaver study

BACKGROUND

A new locking-plate for femoral-neck fractures that provides angular stability to three screws in an inverted triangle configuration was evaluated. The plate is not fixed to the lateral cortex and therefore represents a new treatment principle.

METHODS

Twelve pairs of cadaver femurs (mean T-score -1,95 (range -4,5-0)) with subcapital femoral-neck fractures angulating 60° were randomly allocated to fracture-fixation using either three individual screws or three interlocked screws. Subject-specific axial force and torque were applied by a hip simulator and three-dimensional migrations were recorded. The femurs underwent 10,000 cycles of simulated partial weight-bearing, followed by 10,000 cycles of simulated full weight-bearing and stair climbing.

FINDINGS

On average interlocking reduced femoral-head centre migrations 1.6mm (95% CI 0.1-3.1, P = 0.04). The intra-pair correlation of migration was 0.953 (Pearson's r). Interlocking did not change rotational stability (P = 0.87). Adding a locking plate did not affect the risk of failure, however all failed femurs were fixed using the smallest-sized aiming guide.

INTERPRETATIONS

Adding a lateral interlocking plate to three screws might improve the fracture stability. However, none of the implants were able to resist the unwanted deformation of the proximal femur. Regardless of the fixation, female sex, reduced bone quality and small sized femurs appear to increase risk of failure.

Mono- versus polyaxial locking plates in distal femur fractures: a prospective randomized multicentre clinical trial

PURPOSE

Treatment of complex fractures of the distal femur utilizing monoaxial locking plates (e.g. Less Invasive Stabilisation System, LISS®, Synthes) is considered to be superior to conventional plating systems. Due to the limitation that the thread forces the screw into pre-determined positions, modifications have been made to allow screw positioning within a range of 30° (Non Contact Bridging, NCB®-DF, Zimmer). For the first time, this multicenter prospective randomized clinical trial (RCT) investigates the outcome of LISS® vs. NCB®-DF treatment following complex fractures of the distal femur.

METHODS

Since June 2008, 27 patients with a fracture of the distal femur (AO ASIF 33-A-C and periprosthetic fractures) were enrolled in this study by four university trauma centres in southern Germany. Clinical (e.g. range of motion, Oxford knee score, Tegner score) and radiological (e.g. axis deviation, secondary loss of realignment) follow-ups were conducted one and six weeks, as well as three, six, and 12 months after the operation.

RESULTS

This study comprises data of 27 patients (8 male, 19 female; 15 NCB®-DF, 12 LISS®). Polyaxial osteosynthesis using the NCB® system tended to result in better functional knee scores and a higher range of motion. Interestingly, fracture union tended to be more rapid using the polyaxial plating system.

CONCLUSIONS

We present the analysis of a multicenter prospective RCT to compare the monoaxial LISS® vs. the polyaxial NCB®-DF treatment following complex fractures of the distal femur. NCB®-DF treatment tended to result in better functional and radiological outcomes than LISS® treatment.

LEVEL OF EVIDENCE

Level I.

Computational simulation of the early stage of bone healing under different configurations of locking compression plates

Flexible fixation or the so-called 'biological fixation' has been shown to encourage the formation of fracture callus, leading to better healing outcomes. However, the nature of the relationship between the degree of mechanical stability provided by a flexible fixation and the optimal healing outcomes has not been fully understood. In this study, we have developed a validated quantitative model to predict how cells in fracture callus might respond to change in their mechanical microenvironment due to different configurations of locking compression plate (LCP) in clinical practice, particularly in the early stage of healing. The model predicts that increasing flexibility of the LCP by changing the bone-plate distance (BPD) or the plate working length (WL) could enhance interfragmentary strain in the presence of a relatively large gap size (> 3 mm). Furthermore, conventional LCP normally results in asymmetric tissue development during early stage of callus formation, and the increase of BPD or WL is insufficient to alleviate this problem.

Fractures of the proximal humerus

Fractures of the proximal humerus have been diagnosed and managed since the earliest known surgical texts. For more than four millennia the preferred treatment was forceful traction, closed reduction, and immobilization with linen soaked in combinations of oil, honey, alum, wine, or cerate. The bandages were further supported by splints made of wood or coarse grass. Healing was expected in forty days. Different fracture patterns have been discussed and classified since Ancient Greece. Current classification of proximal humeral fractures mainly relies on the classifications proposed by Charles Neer and the AO/OTA classification. Since the late 1980's it has been known that intra- and inter-observer variation was high within the two systems. I conducted a series of observer studies to qualify the disagreement further and to study to what extent improvement of agreement could be obtained. No clinically significant differences in observer agreement were found at different levels of clinical experience, by reducing the number of categories, or by adding high quality radiographs, CT or 3D CT scans. A consistently low agreement on the Neer classification within and between untrained orthopaedic doctors was found. However, we also found that inter-observer agreement on treatment recommendation was higher than the agreement on the Neer classification. In a randomized trial we found that agreement could improve significantly by training of doctors, especially among specialists. However, classification of proximal humeral fractures remains a challenge for the conduct, reporting, and interpretation of clinical trials. The evidence for the benefits of surgery in complex fractures of the proximal humerus is weak. In three systematic reviews I studied the outcome after locking plate osteosynthesis or reverse arthroplasty in complex fractures patterns. No randomized trials or well-conducted comparative studies were identified. High failure rates suggest that the use of these implants for complex fractures of the humerus should not be used outside clinical protocols. I recommend the conduct of randomized trials, and a design of such study is proposed.

Finite element analysis of Puddu and Tomofix plate fixation for open wedge high tibial osteotomy

The use of open wedge high tibial osteotomy (HTO) to correct varus deformity of the knee is well established. However, the stability of the various implants used in this procedure has not been previously demonstrated. In this study, the two most common types of plates were analysed (1) the Puddu plates that use the dynamic compression plate (DCP) concept, and (2) the Tomofix plate that uses the locking compression plate (LCP) concept. Three dimensional model of the tibia was reconstructed from computed tomography images obtained from the Medical Implant Technology Group datasets. Osteotomy and fixation models were simulated through computational processing. Simulated loading was applied at 60:40 ratios on the medial:lateral aspect during single limb stance. The model was fixed distally in all degrees of freedom. Simulated data generated from the micromotions, displacement and, implant stress were captured. At the prescribed loads, a higher displacement of 3.25 mm was observed for the Puddu plate model (p<0.001). Coincidentally the amount of stresses subjected to this plate, 24.7 MPa, was also significantly lower (p<0.001). There was significant negative correlation (p<0.001) between implant stresses to that of the amount of fracture displacement which signifies a less stable fixation using Puddu plates. In conclusion, this study demonstrates that the Tomofix plate produces superior stability for bony fixation in HTO procedures.

Complications after open reduction and internal fixation of ankle fractures in the elderly

BACKGROUND

Open reduction with internal fixation for unstable ankle fractures is relatively predictable with excellent outcomes. However, the management of ankle fractures in the elderly remains less predictable secondary to the various co-morbidities associated with advanced age.

METHODS

A retrospective chart review of 216 patients over the age of 60 that sustained an ankle fracture, was performed to determine the incidence of complications after ORIF of ankle fractures in an elderly population in the perioperative course. Secondly, the incidence of complications in patients that had locking plate fixation compared to those that had non-locking plate fixation was determined. Lastly, the effect of early weight bearing on the incidence of complications was analyzed.

RESULTS

There was not a statistically significant difference in the complication rates between the group with co-morbidities (19.01%) and those without (11.96%). The postoperative complication with the highest incidence was wound dehiscence (9.7%), and only diabetes significantly predicted wound dehiscence. The fixation construct and weight-bearing protocol failed to significantly predict any of the indexed complications.

CONCLUSIONS

Overall, the results suggest that surgical treatment of unstable ankle fractures in the elderly is fairly predictable with an acceptable complication rate. The complication rates are higher with increased age and diabetes, but they failed to reach statistical significance. Conventional plating appears to provide adequate stability without increased risk of hardware failure. In addition patients that were allowed to walk within the first 2 weeks postoperatively did not experience a higher rate of hardware failure.

Locking plates in osteoporosis: a biomechanical cadaveric study of diaphyseal humerus fractures

OBJECTIVE

To determine whether locking plates offer an advantage in fixation of fractures in osteoporotic humeral bone.

DESIGN

Biomechanical testing of 18 matched pairs of osteoporotic human cadaver humeri plated posteriorly with either all locked or all nonlocked screws. An established protocol was used to test the constructs with torque applied to a peak of ±10 Nm for 1000 cycles at 0.3 Hz or until failure. Eighteen pairs were tested for failure, 11 pairs were tested for cycles survived, and 10 pairs were tested for stiffness.

SETTING

University biomechanical laboratory.

MAIN OUTCOME MEASUREMENTS

Percentage surviving testing, mean cycles survived, and stiffness.

RESULTS

We observed catastrophic failure of the constructs in 47% of the samples. Humeri plated with nonlocking plates failed at a higher rate than those with locking plates (67% nonlocking vs 28% locking, n = 18 pairs, P = 0.008). Locking constructs also outperformed nonlocking constructs in mean cycles survived (707 cycles locking, 345 cycles nonlocking, n = 11 pairs, P < 0.05) and stiffness at 10 cycles (0.853 Nm/degree locking vs 0.416 Nm/degree nonlocking, n = 10 pairs, P < 0.001).

CONCLUSIONS

Locking plates were shown to provide improved mechanical performance over nonlocking plates in torsional cyclic loading in a osteoporotic cadaveric fracture model. Our results confirm general conclusions of previous work that used a synthetic bone model of osteoporosis, but we found a high rate of catastrophic failure, questioning the validity of the previously published synthetic model of osteoporosis (overdrilling of synthetic bone) for this application.

Clinical outcome and complications using a polyaxial locking plate in the treatment of displaced proximal humerus fractures. A reliable system?

INTRODUCTION

The surgical treatment of displaced proximal humeral fractures (ORIF) is a perpetual challenge to the surgeon. For this reason, the principle of polyaxiality was developed to provide an improved primary stability of the fracture through better anchorage of the screws, especially in osteoporotic bone. The aim of this study was to present clinical results with the polyaxial locking plate in the operative treatment of proximal humerus fractures in order to determine whether the technique of polyaxiality leads to better functional outcome and lower complication rates in comparison to monoaxial plates in the literature.

PATIENTS AND METHODS

Seventy-three patients with displaced proximal humeral fractures were treated surgically with the polyaxial locking Suture Plate™ (Arthrex(®)) between 03/2007 and 06/2009. Fifty-two of the patients (mean age, 69.9 ± 12.1) were included in a radiographical and clinical examination using the Constant score (CS) and the Disabilities of the Arm, Shoulder and Hand score (DASH).

RESULTS

The follow-up examinations were on average 13.9 ± 4.5 months (10-27 months) after surgical treatment. The mean CS of the patients was 66.0 ± 13.7 points, the age- and gender-related CS was 90.9% ± 20.0% and the mean DASH score was 23.8 ± 19.8 points for the injured side. The patients with a nearly anatomical reduction of their fracture (n = 13) reached a significantly higher CS (75.1 ± 8.5; p = 0.004) and DASH-score (13.6 ± 11.6; p = 0.043) and none of these patients had a complication. The complications were identified in 12 (23.1%) cases, 5 of which involved loss of reduction. All of these 5 cases were lacking of initial medial column support and 4 of which were type C2.3 AO-Classification.

CONCLUSION

The data show that the combination of angular stability with the possibility of variable polyaxial screw direction is a good concept for reduction and fixation of displaced proximal humeral fractures, but anatomical reduction and medial support remain important preconditions for a good outcome. However, a significantly lower rate of complications or better clinical outcome than that reported in the literature could not be found.

Surgical treatment with an angular stable plate for complex displaced proximal humeral fractures in elderly patients: a randomized controlled trial

OBJECTIVE

The objective of the study was to evaluate functional outcome, patient self-assessment, and radiographic outcome at 1 year in displaced three- and four-part proximal humeral fractures (OTA group 11-B2 and 11-C2).

DESIGN

Randomized controlled trial.

SETTING

Academic medical center.

PATIENTS/PARTICIPANTS

Fifty patients aged 60 years or older with displaced three- or four-part proximal humeral fractures and no previous shoulder injuries were randomized either to surgical treatment or to conservative closed treatment. Twenty-five patients were included in each group. Forty-eight patients completed 12-month follow-up. Two surgical patients died within 3 months.

INTERVENTION

The surgically treated group had a standardized surgical treatment with open reduction and internal fixation using an angular stable plate and cerclages. Instructed physical therapy started the third postoperative day. The conservative treatment group had a standardized nonoperative treatment that included closed reduction if displacement between the head and metaphyseal shaft fragment exceeded 50% of the diaphyseal diameter. Physical therapy started on the fifteenth postoperative day.

MAIN OUTCOME MEASUREMENTS

The main outcome was the mean difference in Constant score between the injured and noninjured shoulder at 12 months. The secondary outcomes were patient self-assessment (American Shoulder and Elbow Surgeons score) and radiographic ratings at 12 months.

RESULTS

At 12 months, mean Constant scores favored conservative treatment by 2.4 points (nonsignificant; P = 0.62). There was no significant difference in mean patient self-assessment. However, radiographic outcomes were significantly better for surgically treated patients.

CONCLUSION

There is no evidence of a difference in functional outcome at 1-year follow-up between surgical treatment and conservative treatment of displaced proximal humeral fractures in elderly patients.

Mechanical evaluation of fourth-generation composite femur hybrid locking plate constructs

Locking compression plates are routinely used for open reduction and internal fixation of fractures. Such plates allow for locking or non-locking screw placement in each hole. A combined use of both types of screw application for stabilization of a fracture is commonly applied and referred to as hybrid internal fixation. Locking screws improve the stability of the fixation construct but at the expense of significant additional cost. This study experimentally analyzes various combinations of locking and non-locking screws under simultaneous axial and torsional loading to determine the optimal hybrid locking plate-screw construct in a fourth generation composite femur. Clinically it is necessary to ensure adequate fixation stability in a worse case fracture-bone quality scenario. A locking screw near the fracture gap increased the axial and torsional strength of the locked plate system. Greater removal torque remained in non-locked screws adjacent to locked screws compared to an all non-locking screws control group.

Locking plate osteosynthesis in displaced 4-part fractures of the proximal humerus

BACKGROUND AND PURPOSE

There is considerable uncertainty about the optimal treatment of displaced 4-part fractures of the proximal humerus. Within the last decade, locking plate technology has been considered a breakthrough in the treatment of these complex injuries.

METHODS

We systematically identified and reviewed clinical studies on the benefits and harms after osteosynthesis with locking plates in displaced 4-part fractures.

RESULTS

We included 14 studies with 374 four-part fractures. There were 10 case series, 3 retrospective observational comparative studies, 1 prospective observational comparative study, and no randomized trials. Small studies with a high risk of bias precluded reliable estimates of functional outcome. High rates of complications (16-64%) and reoperations (11-27%) were reported.

INTERPRETATION

The empirical foundation for the value of locking plates in displaced 4-part fractures of the proximal humerus is weak. We emphasize the need for well-conducted randomized trials and observational studies.