Biomechanical comparison of 4 different lateral plate constructs for distal fibula fractures

Management of non-unions of the malleolar fractures- Current Evidence

Although malleolar non-union is uncommon, it is associated with significant morbidity. Managing this problem requires understanding ankle fracture biomechanics and bone healing. We present in this article the pertinent points to be considered in evaluating and managing patients with malleolar non-union. Our discussion will focus on the important risk factors contributing to this problem, and the need to carefully consider the biomechanical stability and the biological environment to ensure successful bony unions.

Finite element analysis and a pilot study of different fixation constructs for Danis-Weber A and B lateral malleolus fractures

BACKGROUND

Displaced lateral malleolus fractures are typically stabilised through open reduction and internal fixation. The biomechanically and clinically efficacy of locking plates and lag screws, particularly in Weber A and B distal fibular fractures remains a subject of contention. This study examines two locking plate designs for lateral malleolus fractures, evaluating their performance with and without interfragmentary screws using finite element models.

METHODS

Utilising CT images of a healthy adult male volunteer, a three-dimensional finite element model was constructed. The Fibula-specific Flank Multiaxial Locking Anatomic Plate (FMLP) and the Conventional Locking Plate (CLP) were subjected to stabilisation, both with and without an interfragmentary screw, mimicking the Danis-Weber A and B lateral malleolus oblique fracture fixation. Loads of 140 N and 70 N, equivalent to 20% of the body weight, were applied to simulate the single-leg and two-leg standing conditions in the axial direction. The von Mises stress (VMS) distributions and element displacements were subsequently analyzed.

RESULTS

In the Danis-Weber A fracture model group, the FMLP with an interfragmentary screw fixation exhibited the lowest peak VMS values: 51.9 MPa in the fibula, 89.0 MPa in the plate, and 61.3 MPa in the screws for simulating single-leg conditions. Under two-leg standing conditions, these peak VMS values decreased to 25.9 MPa in the fibula, 44.5 MPa in the plate, and 30.6 MPa in the screws, respectively. Furthermore, the overall structural peak displacements during single-leg standing for both Weber-A and B fractures with different implants ranged from 1.61 to 2.54 mm. While standing on two feet, the ranged was from 0.80 to 1.27 mm. An interfragmentary screw at the oblique fracture site resulted in reduced the peak value of VMS in the fibula, plate, screws, consequently decreased the overall structural displacement for FMLP and CLP fixation in lateral malleolus fractures.

CONCLUSIONS

The current finite element analysis (FEA) demonstrates that FMLP exhibits superior mechanical characteristics in Danis-Weber A and B lateral malleolus fractures compared to CLP. The inclusion of an interfragmentary screw, combined with locking plate design, enhances stability for simple oblique distal fibular fractures. The FMLP presents itself as potential as an alternative for lateral malleolus fractures from a biomechanical perspective. Nevertheless, further verification of these results is imperative through subsequent clinical studies.

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.

Retrospective analysis of locked versus non-locked plating of distal fibula fractures

INTRODUCTION

Unstable distal fibular fractures have traditionally been treated with open reduction internal fixation using a 1/3 tubular non-locked plate (compression plating). Locked plating is a newer technique that has become more popular despite the lack of clinical data supporting improved outcomes. The cost of locked plating is almost four times that of compression plating. We compared rates of reoperation due to implant failure, infection, and symptomatic device between compression and locked plating in open reduction internal fixation of distal fibular fractures METHODS: A retrospective study was performed at a level one trauma center over a ten-year period (2008-2017). Patients who were 18 and older and treated for unstable ankle fractures with locking or non-locking plate were included in this study. Patient charts were reviewed by orthopedic trauma surgeons to identify whether patients were treated with a 1/3 tubular non-locking or pre-contoured locked plate and to determine the cause of reoperation.

RESULTS

In total, 442 patients were identified with 203 in the non-locked 1/3 tubular plate group and 239 in the pre-contoured locked plate group. A total of 38 patients (8.6%) underwent device removal with a higher proportion of patients in the non-locked 1/3 tubular plate cohort (11.3% vs. 6.3%, p = 0.059). Statistically significant differences in reasons for reoperation were found for symptomatic implant (78.3% vs. 46.7%, p = 0.045) and infection (8.7% vs 53.3%., p < 0.01). Of patients who had device removal for symptomatic implant in the compression plating cohort, 13 (72.2%) had lateral positioning and 5 (27.8%) had posterior positioning (p < 0.01) whereas there was no statistical difference in plate positioning in the locked cohort. Of all medical comorbidities identified, only diabetes was associated with a higher rate of infection-related reoperations (83.3% vs. 15.6%, p < 0.01).

CONCLUSIONS

Both compression and locked plate techniques demonstrated low reoperation rates. Compression plating with 1/3 tubular plates placed laterally more often resulted in reoperation due to symptomatic implant but had fewer complications of infection. Given that the cost is significantly less, 1/3 tubular plating placed posteriorly may be preferred to decrease the risks of symptomatic implant and infection.

A Prospective Randomized Study Comparing Functional Outcome in Distal Fibula Fractures between Conventional AO Semitubular Plating and Minimal Invasive Intramedullary "Photodynamic Bone Stabilisation"

(1) Background: As age in western populations is rising, so too are fractures, e.g., of the distal fibula. The aim of this study was to find out whether a novel, minimally invasive intramedullary osteosynthesis technique for the treatment of distal fibula fractures in elderly patients results in not only a reduction of postoperative complications, but also a shorter hospitalization time, an improved clinical outcome, and preserved autonomy in geriatric trauma patients. (2) Methods: In this prospective study, the results following surgical treatment for distal fibula fractures in geriatric patients after using DePuy Synthes^® one-third semitubular plate (Group I) or a minimally invasive intramedullary photodynamic Bone StabilizationSystem (IlluminOss^®) (Group II) were compared at 6 weeks, 12 weeks, 6 months, and 1 year after initial treatment. (3) Results: Significant improvement regarding clinical outcome was shown in Group II 6 and 12 weeks after surgery. (4) Conclusions: Our study results demonstrate that the use of this new intramedullary stabilization system in combination with an immediate postoperative weight bearing seems to be a safe and stable treatment option for ankle fractures in geriatric patients, especially in the early stages of recovery.

Three internal fixation methods for Danis-Weber-B distal fibular fractures: A biomechanical comparison in an osteoporotic fibula model

A common agreement for the surgical treatment of osteoporotic ankle fractures has not been defined yet although locking plates are preferred for fractures with poor bone quality. This study aims to evaluate the mechanical stability of locked and conventional plates on osteoporotic Danis-Weber-B-fibula fracture models. Fractured custom-made osteoporotic fibulae were treated with neutralization plate plus lag screw, locking plate plus lag screw, or a standalone locking plate. Load until failure was applied mimicking single-leg stance. Stiffness, failureload, and interfragmentary movements were investigated. Stiffness, failureload and axial fragment movement showed no significant differences among groups. Shear movements and fragment rotation around the shaft of the neutralization plate were on average twice as high as those of the locking plates. Although no superiority was shown for overall mechanical performance, the locking plate groups exhibited higher shear and rotational stability than the neutralization plate.

One-Third Tubular Plate Remains a Clinically Good Option in Danis-Weber Type B Distal Fibular Fracture Fixation

OBJECTIVE

To compare the clinical outcomes of locking plate (LP) and non-locking one-third tubular plate (TP) fixation, and to provide guidance on plate selection for Danis-Weber type B distal fibular fracture treatment.

METHODS

In total, 83 patients who underwent plate fixation for Danis-Weber type B distal fibular fractures between March 2013 and July 2018 were retrospectively reviewed: 41 (49.0%) received LPs and 42 (51.0%) received TPs. Patients' demographic data, follow-up durations, the proportion of comminuted fractures, and ankle range of motion were investigated. The American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale, Karlsson scale, Foot and Ankle Ability Measure (FAAM), and Lower Extremity Functional Scale (LEFS) scores were assessed. The radiographic union progression and implant removal time were evaluated, along with postoperative complications. Data from the LP and TP groups were compared statistically.

RESULTS

The mean patient ages were 53.3 ± 17.5 years (range, 16-80 years) and 47.6 ± 17.0 years (range, 14-68 years) in the LP and TP groups, respectively (P > 0.05). The gender distribution did not differ significantly between groups (P > 0.05). Other demographic data also did not differ significantly between groups (P > 0.05). The mean follow-up durations were 16.8 ± 7.7 months (range, 13.0-19.0 months) in the LP group and 16.1 ± 6.2 months (range, 12.0-20.0 months) in the TP group (P > 0.05). Comminuted fractures were observed in 18 of 41 (43.9%) patients with LP and 10 of 42 (23.8%) patients with TP (P > 0.05). Forward bending ankle dorsiflexion was possible at the final follow-up in 82.9% and 85.7% of LP and TP patients, respectively (P > 0.05). The AOFAS ankle-hindfoot scale, Karlsson scale, FAAM, and LEFS scores did not differ significantly between groups at the final follow-up (P > 0.05). The pre-fracture and final postoperative scores on these four instruments did not differ significantly in the LP or TP group (P > 0.05). The mean times to radiographic union progression were 13.5 ± 7.1 weeks and 15.1 ± 10.2 weeks in the LP and TP groups, respectively (P > 0.05). The mean times to implant removal surgery reaffirming solid union were 15.6 ± 5.5 months and 14.8 ± 4.9 months in the LP and TP groups, respectively (P > 0.05). Hardware irritation was detected in five patients in the LP group (12.2%) and three in the TP group (7.1%) (P > 0.05). One patient in the LP group and two in the TP group developed superficial wound infections, which resolved without further surgical intervention.

CONCLUSION

Conventional TP remains a good option for the fixation of Danis-Weber type B distal fibular fractures, regardless of the biomechanical properties.

Association Between Bone Mineral Density and Elderly Ankle Fractures: A Systematic Review and Meta-Analysis

Ankle fractures are becoming increasingly more common in the elderly population and present a significant burden to the United States health care system. Many factors have been associated with fragility ankle fractures including age, gender, body mass index, diabetes, tobacco use, and osteoporosis. However, the literature is inconsistent regarding the relationship between ankle fractures and osteoporosis. The primary aim of this meta-analysis was to quantify the relationship between bone mineral density (BMD) in elderly patients with ankle fractures compared with BMD in elderly patients without ankle fractures. A literature search was undertaken using relevant search terms. Articles were screened for suitability and data extracted where studies met inclusion criteria and were of sufficient quality. Data were combined using standard meta-analysis methods. Seven studies were used in the final analysis. A small-pooled effect size was found indicating the control group had increased BMD regardless of measurement used (95% confidence interval 0.09-0.58; I² = 98.39%). Lower femoral neck BMD showed a small-pooled effect size (femoral neck 0.36; 95% confidence interval 0.00-0.73; I² = 94.91%) with the ankle fracture cohort. This is the first meta-analysis to quantify the relationship between BMD and ankle fractures in the elderly population. Elderly ankle fractures showed a significant association with femoral neck BMD. The current data can be used in orthopedic clinics and Fracture Liaison Service programs to assign the appropriate subgroup of ankle fracture patients to investigative and treatment groups, assess fracture risk, and serve as an indication for secondary fracture prevention by stimulating an osteoporosis prevention workup. There may be a role for a team approach to fracture care including metabolic optimization.

Fibula fractures management

Isolated distal fibula fractures represent the majority of ankle fractures. These fractures are often the result of a low-energy trauma with external rotation and supination mechanism. Diagnosis is based on clinical signs and radiographic exam. Stress X-rays have a role in detecting associated mortise instability. Management depends on fracture type, displacement and associated ankle instability. For simple, minimally displaced fractures without ankle instability, conservative treatment leads to excellent results. Conservative treatment must also be considered in overaged unhealthy patients, even in unstable fractures. Surgical treatment is indicated when fracture or ankle instability are present, with several techniques described. Outcome is excellent in most cases. Complications regarding wound healing are frequent, especially with plate fixation, whereas other complications are uncommon.

Is early full weight bearing safe following locking plate ORIF of distal fibula fractures?

Background

In the modern western world appraisal of economical points such as treatment and disability after trauma present a financial burden. In this context open reduction internal fixation techniques allowing for early full weight bearing might not only improve the clinical outcome but also shorten the period of disability in working life. The aim of the study was to analyze whether ORIF of ankle fractures using either a standard semitubular plate or a new polyaxial locking plate system result in a better clinical outcome.

Methods

In this prospective study, all patients with distal fibula fractures (AO 44 B1.1, B1.2, B1.3), with indication for surgery were included. Patients were randomized to either the DePuy Synthes® one-third semitubular plate (Group I) or NEWCLIP TECHNICS, Active Ankle® polyaxial locking plate (Group II). Primary outcome parameter was function of the ankle joint, assessed by the Olerud and Molander ankle score, Foot and Ankle outcome score and Karlsson and Peterson Scoring System for Ankle function. Secondary outcome parameter were postoperative complications. Superficial wound infection, delayed wound healing, mechanically prominent implant, skin irritations were considered as minor and deep wound infection, material loosening, loss of reduction were regarded as major complications requiring revision surgery. Clinical and radiological follow-up were performed 6 and 12 weeks, 6 months and 1 year postoperatively.

Results

Fifty-two patients (31 W/21 M) with a mean age of 43 yrs. (range 22–64 yrs.) were enrolled. Seven patients (13.5%) were excluded, so that 45 patients were available for follow up. Twenty-five patients were treated with DePuy Synthes® one-third semitubular plate (55.6%; group I) while 20 patients received an anatomically preformed polyaxial locking plate (44.4%, group II). Four minor complications occurred in Group I (16%) compared to two minor complications in group II (10%). Significant better clinical results regarding OMAS (p < 0.02, < 0.04), KPSS (p < 0.04) and FAOS (p < 0.02, < 0.03) were observed 6 and 12 weeks after surgery in group II.

Conclusions

The results of the presented study demonstrate a significant better clinical functional outcome in the early postoperative follow-up in patients treated with a polyaxial locking plate. Furthermore, our data show that ORIF using polyaxial locking plates in combination with an early postoperative weight bearing presents a safe, stable treatment option for ankle fractures so that patients benefit especially in the early stages of recovery.

Trial registration

Registered 20 April 2020, retrospectively on ClinicalTrails.gov (NCT04370561).

Twisted Plating - A Method of Distal Fibula Fixation

Objective  The literature entails various intramedullary and extramedullary methods for distal fibula fracture fixation; with no consensus yet over the ideal method of fixation. We have retrospectively analyzed the results of using a twisted and contoured 3.5 mm locking compression plate (LCP) as a posterior buttress plate. Methods  Of the 62 cases with ankle fractures managed at our institute by the senior author from 1 ^st January 2012 to 31 ^st December 2015, 41 patients met our inclusion criteria (Danis-Weber types B and C). Results  All 41 distal fibular fractures healed uneventfully, at a mean of 10.4 weeks (8-14 weeks) (Figs. 6, 7, 8 to 9) with no complications. The mean American Orthopaedic Foot & Ankle Society (AOFAS) score was 92.6 (86-100) at a mean follow-up of 31.5 months (14-61 months). Conclusions  We have achieved excellent clinical and radiological outcomes using a twisted 3.5 mm LCP as a posterior buttress by combining the advantages of posterior antiglide plating and lateral LCP.

Operative treatment of geriatric ankle fractures with conventional or locking plates. A retrospective case-control study

BACKGROUND

The incidence of geriatric ankle fractures continues to rise due to demographic changes. While locking plates have become standard implants for injuries of other body regions, clinical studies on their use for geriatric ankle fractures are rare.

METHODS

Therefore, a retrospective case-control study, including 333 patients with a mean age of 73.5 years was performed. 263 patients underwent operative fixation with one- third tubular plates and 70 were treated with locking plates. Early outcomes and complication rates of locking plates as compared with conventional one- third tubular plates are described.

RESULTS

In the present study, patients treated with locking plates were older and suffered from more severe fracture patterns. In addition, these patients had more severe comorbidities. Treatment with conventional or locking plate fixation resulted in a comparable complication and revision rate. A matched pair analysis showed significantly more complications and required revision surgeries and a trend towards more implant failures in the group that underwent conventional plating.

CONCLUSIONS

Therefore, we conclude that precontoured locking plates represent an appropriate treatment option for severe ankle fractures in patients suffering from relevant co-morbidities. Prospective randomized trials are warranted to prove superiority of locking plates for treatment of geriatric ankle fractures. Level 3: Retrospective case- control study.

Dual Nonlocked Plating as an Alternative to Locked Plating for Comminuted Distal Fibula Fractures: A Biomechanical Comparison Study

The purpose of this cadaveric study was to compare the biomechanical properties of dual nonlocked plating and single-locked plating using matched pairs of isolated fibula specimens. Fractures were simulated in 10 matched pairs of isolated cadaveric fibulae and plated with a single lateral locking plate for right-sided specimens, or with a one-third tubular plate and a 7-hole 2.4-mm minifragment adaption plate for left-sided specimens. An external rotation torque was applied at a rate of 1°/second, and torque at 10° was measured. Each fibula specimen was evaluated using a micro computed tomography scanner, and bone mineral density was calculated as milligrams of bone per cubic centimeter of volume. Dual nonlocked plating and locked plating specimens demonstrated torque measurements that were not significantly different at 10° of external rotation (1.48 N·m and 1.92 N·m, respectively; p = .093). The stiffness of the dual nonlocked plated and locked plating constructs were not significantly different (p = .228 and p = .543, respectively). The effect of bone mineral density on maximum torque at failure was not a reliable predictor of maximum torque in either the dual nonlocked plating or locked plating specimens (R² = 0.548 and R² = 0.096, respectively). We found no differences in torque at 10° of external rotation or stiffness between locking plate and dual nonlocking plate fixation constructs. This study provides evidence that dual nonlocked plating likely constitutes adequate fixation in situations in which a locking plate is being considered for comminuted distal fibula fractures.

Comparison of different locking plate fixation methods in lateral malleolus fractures

BACKGROUND

Several fixation methods may be used for displaced lateral malleolar fractures. We aimed to compare clinical and radiologic outcomes associated with use of locking one third tubular plate vs. anatomical distal fibula locking plate in lateral malleolar fractures.

METHODS

A total of 62 orthopedic patients operated for lateral malleolus fracture were included in this retrospective study. Patients were divided into two groups regarding the plate used for fixation as locking one third tubular plate (group I; n=37) and locking anatomical distal fibula plate (group II; n=25). Data on Danis-Weber ankle fracture classification (Type A, Type B), duration of follow up, clinical outcome [ankle range of motion (ROM), American Orthopaedic Foot & Ankle Society (AOFAS) score], radiological outcomes (adequacy of reduction, loss of alignment), time to fracture healing and complications were recorded in study groups.

RESULTS

No significant difference was noted between groups in terms of AOFAS score [87.0 (73-100) vs. 85.0 (71-100), respectively (p=0.339)] and no patients had severe restriction in sagittal and hindfoot motion in both groups. The two groups showed similar healing time [9.0 (7-13) weeks vs. 10.0 (8-13) weeks, respectively (p=0.355)] and complication rate [0.0% vs. 4.0%, respectively (p=0.403)].

CONCLUSIONS

This study revealed no significant difference between use of locking one third tubular plate and locking anatomical distal fibula plate in lateral malleolar fixation, in terms of clinical and radiological outcomes, complication rates and fracture healing time.

Lower Bone Density on Preoperative Computed Tomography Predicts Periprosthetic Fracture Risk in Total Ankle Arthroplasty

BACKGROUND:

The effect of bone mineral density (BMD) on outcomes from total ankle arthroplasty (TAA) has not been studied. BMD can be estimated by measuring Hounsfield units (HU) on standard computed tomography (CT), which is frequently performed prior to TAA. We aimed to identify whether tibial and talar HU measured from preoperative CT scans were associated with periprosthetic fracture or revision risk in patients undergoing TAA.

METHODS:

A prospectively collected database was used to retrospectively screen all patients undergoing primary TAA. Only patients with a preoperative CT within 1 year of surgery were included. Primary outcomes were periprosthetic fracture and prosthetic revision. HU were measured on axial CT cuts in the distal tibia and talus. Additional patient factors analyzed included age, sex, weight, body mass index (BMI), tobacco use, presence of rheumatoid arthritis, and preoperative deformity. A total of 198 ankles were included, with a mean 2.4 years of follow-up.

RESULTS:

There were 7 intraoperative and 9 postoperative periprosthetic fractures (3.5% and 4.5%, respectively). Seven patients (3.5%) underwent prosthetic removal or revision. Lower tibial and talar HU, lower weight, and lower BMI were associated with periprosthetic fractures ( P < .05). After controlling for age, sex, and weight, only tibial HU was significantly associated with periprosthetic fracture ( P = .018). All intraoperative fractures occurred in patients with tibial HU less than 200. None of the patient factors analyzed were associated with revision.

CONCLUSIONS:

Lower tibial HU on preoperative CT was strongly associated with periprosthetic fracture risk with TAA. In patients with tibial HU less than 200, surgeons may consider prophylactic internal fixation of the medial malleolus.

LEVEL OF EVIDENCE:

Level III, retrospective cohort study.

Tubular vs Profile Plate in Peroneal or Bimalleolar Fractures: is There a Real Difference in Skin Complication? A Retrospective Study in Three Level I Trauma Center

Introduction:

Not enough literature is available to evalute the wound complication rate of plates type in distal fibular fractures.

Aim:

The aim of our study was to compare wound complications of using a third tubular plate compared to LCP distal fibula plate.

Material and Methods:

This study is a retrospective single-centre study in which was performed plating of fibula in closed ankle fractures. 93 patients were included in our study and assigned in two groups, based on using of different implant : in group A 48 patients were treated with one-third tubular and in group B 45 patients were treated with LCP distal fibula plate. There were no significant differences in the baseline characterisctics. Patients received the same surgical procedure and the same post-operative care, then they were radiologically evalueted at 1-3-12 months and clinical examination was made at 12 months using AOFAS clinical rating system. Categorical data, grouped into distinct categories, were evalueted using Chi-square test. We considered a p value < 0.05 as statistically significant.

Results:

The wound complications rate of the overall study group was 7.6%. There were no statistical differences in the rate of wound complications between the two groups. There were no differences between both group in percentage of hardware removal at follow-up (overall 5.4%); plate removal was performed earlier in the locking plate because of wound complications.

Conclusions:

Our study has shown no difference in radiographic bone union rate, no significant differences in terms of clinical outcomes, in time of bone reduction and wound complication rate between the LCP distal fibula plate and conventional one-third tubular plate. Controversy still exists about the best method for the fracture reduction.

Biomechanical analysis of polyaxial locking vs. non-locking plate fixation of unstable fractures of the distal fibula: A cadaver study with a bone only model

BACKGROUND

Open reduction and internal fixation is the current standard of treatment of displaced distal fibula fractures, whereupon using a lag screw often is impossible because of a multifragmantary fracturezone. This study investigates in what extend polyaxial-locking plating is superior to non-locking constructs in unstable distal fibula fractures.

METHODS

Seven pairs of human cadaver fibulae were double osteotomized in standardized fashion with a 5mm gap. This gap simulated an area of comminution, where both main fragments were no longer in direct contact. One fibula of the pair was managed using a 3.5-mm screw in a polyaxial-locking construct and the other fibula in a non-locking construct.

Costs and Radiographic Outcomes of Rotational Ankle Fractures Treated by Orthopaedic Surgeons With or Without Trauma Fellowship Training

INTRODUCTION

We evaluated the radiographic outcomes and surgical costs of surgically treated rotational ankle fractures in our health system between providers who had completed a trauma fellowship and those who had not.

METHODS

We grouped patients into those treated by trauma-trained orthopaedic surgeons (TTOS) and non-trauma-trained orthopaedic surgeons (NTTOS). We graded the quality of fracture reductions and calculated implant-related costs of treatment.

RESULTS

A total of 208 fractures met the inclusion criteria, with 119 in the TTOS group and 89 in the NTTOS group. Five patients lost reduction during the follow-up period. The adequacy of fracture reduction at final follow-up did not differ (P = 0.29). The median surgical cost was $2,940 for the NTTOS group and $1,233 for the TTOS group (P < 0.001).

DISCUSSION

We found no notable differences in radiographic outcomes between the TTOS and NTTOS groups. Cost analysis demonstrated markedly higher implant-related costs for the NTTOS group, with the median surgical cost being more than twice that for the TTOS group.

LEVEL OF EVIDENCE

Level III.

Distal fibula oblique fracture fixation using one-third tubular plate with and without lag screw - A biomechanical study of stability

This laboratory-based study compared distal fibula simple oblique fracture fixation with one-third tubular plate with and without a single lag screw to determine which was mechanically more stable. A control group fixed with a limited contact dynamic compression plate was also tested. Biomechanical testing of 30 osteotomised saw bones under lateral bending and torsional forces was performed. There was no significant difference between the mean lateral bending and mean torsional stiffness between the fixation with tubular plate and lag screw and tubular plate alone. Limited contact dynamic compression plate conferred the best stability in lateral bending and torsion, as expected.

Economic Analysis of Anatomic Plating Versus Tubular Plating for the Treatment of Fibula Fractures

Ankle fractures are among the most common injuries requiring operative management. Implant choices include one-third tubular plates and anatomically precontoured plates. Although cadaveric studies have not revealed biomechanical differences between various plate constructs, there are substantial cost differences. This study sought to characterize the economic implications of implant choice. A retrospective review was undertaken of 201 consecutive patients with operatively treated OTA type 44B and 44C ankles. A Nationwide Inpatient Sample query was performed to estimate the incidence of ankle fractures requiring fibular plating, and a Monte Carlo simulation was conducted with the estimated at-risk US population for associated plate-specific costs. The authors estimated an annual incidence of operatively treated ankle fractures in the United States of 59,029. The average cost was $90.86 (95% confidence interval, $90.84-$90.87) for a one-third tubular plate vs $746.97 (95% confidence interval, $746.55-$747.39) for an anatomic plate. Across the United States, use of only one-third tubular plating over anatomic plating would result in statistically significant savings of $38,729,517 (95% confidence interval, $38,704,773-$38,754,261; P<.0001). General use of one-third tubular plating instead of anatomic plating whenever possible for fibula fractures could result in cost savings of up to nearly $40 million annually in the United States. Unless clinically justifiable on a per-case basis, or until the advent of studies showing substantial clinical benefit, there currently is no reason for the increased expense from widespread use of anatomic plating for fractures amenable to one-third tubular plating. [Orthopedics. 2018; 41(2):e252-e256.].

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.

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.

Does a polyaxial-locking system confer benefits for osteosynthesis of the distal fibula: A cadaver study

BACKGROUND

In plate osteosynthesis involving the distal fibula, antiglide plating is superior to lateral plating in terms of the biomechanical properties. The goal of this study was to examine whether polyaxial-locking implants confer additional benefits in terms of biomechanical stability.

METHODS

Seven pairs of human cadaveric fibulae were subjected to osteotomy in a standardized manner to simulate an uncomplicated Weber B fracture. The generated fractures were managed with a dorsolateral antiglide plate. To this end, one fibula of the pair was subjected to non-locking plating and the other to polyaxial-locking plating. Biomechanical tests included quantification of the primary bending and torsional stiffness. In addition, the number of cycles to failure in cyclic bending loading were determined and compared. Bone mineral density was measured in all specimens.

RESULTS

Bone mineral density was comparable in both groups. Primary stability was higher in the polyaxial-locking group under torsional loading, and higher in the non-locking group under bending loading. The differences, however, were not statistically significant. All specimens except for one fixed-angle construct failed the cyclic loading test. The number of cycles to failure did not differ significantly between polyaxial-locking and non-locking fixation.

CONCLUSION

In a cadaveric Weber B fracture model, we observed no differences in biomechanical properties between polyaxial-locking and non-locking fixation using an antiglide plate. Based on the biomechanical considerations, no recommendation can be made regarding the choice of the implant. Further biomechanical and clinical studies are required.

CLINICAL RELEVANCE

Information on the behavior of polyaxial-locking plates is relevant to surgeons performing internal fixation of distal fibula fractures.

Reinforced fixation of distal fibula fractures in elderly patients; A meta-analysis of biomechanical studies

BACKGROUND

There is an increasing incidence of fragility fractures of the ankle in the elderly population. The open reduction and internal fixation of these fractures is challenging, due to reduced bone stock quality as a result of osteoporosis. Biomechanical studies have shown contradicting results using reinforced constructions in the fixation of fibular fractures. We therefore performed a meta-analysis of biomechanical studies on reinforced fixation of distal fibular fractures.

METHODS

A literature search was conducted utilizing three online databases considering biomechanical testing of different fixation techniques of distal fibular fractures. A meta-analysis was performed on two biomechanical outcome measures; torsional stiffness and torque to failure.

FINDINGS

In a total number of 13 studies 8 different reinforcement techniques were identified. Of these studies, six compared locked lateral plating with conventional lateral plating. There were no statistically significant differences between the locking and non-locking lateral plate for torque to failure or torsional stiffness. Locked plating strength was independent from bone mineral density in four studies. An antiglide plate proved to be biomechanically superior compared to a lateral plate in one study and to a locked plate in another.

INTERPRETATION

Locked lateral plates are not biomechanically superior to conventional lateral plates. However the strength of locked plating may be independent of bone mineral density and could make this technique more suitable in the fixation of severe osteoporotic fractures.

Early Weightbearing After Operatively Treated Ankle Fractures: A Biomechanical Analysis

BACKGROUND

No consensus exists regarding the timing of weightbearing after surgical fixation of unstable traumatic ankle fractures. We evaluated fracture displacement and timing of displacement with simulated early weightbearing in a cadaveric model.

METHODS

Twenty-four fresh-frozen lower extremities were assigned to Group 1, bimalleolar ankle fracture (n=6); Group 2, trimalleolar ankle fracture with unfixed small posterior malleolar fracture (n=9); or Group 3, trimalleolar ankle fracture with fixed large posterior malleolar fracture (n=9) and tested with axial compressive load at 3 Hz from 0 to 1000 N for 250 000 cycles to simulate 5 weeks of full weightbearing. Displacement was measured by differential variable reluctance transducer.

RESULTS

The average motion at all fracture sites in all groups was significantly less than 1 mm (P < .05). Group 1 displacement of the lateral and medial malleolus fracture was 0.1±0.1 mm and 0.4±0.4 mm, respectively. Group 2 displacement of the lateral, medial, and posterior malleolar fracture was 0.6±0.4 mm, 0.5±0.4 mm, and 0.5±0.6 mm, respectively. Group 3 displacement of the lateral, medial, and posterior malleolar fracture was 0.1±0.1 mm, 0.5±0.7 mm, and 0.5±0.4 mm, respectively. The majority of displacement (64.0% to 92.3%) occurred in the first 50 000 cycles. There was no correlation between fracture displacement and bone mineral density.

CONCLUSION

No significant fracture displacement, no hardware failure, and no new fractures occurred in a cadaveric model of early weightbearing in unstable ankle fracture after open reduction and internal fixation.

CLINICAL RELEVANCE

This study supports further investigation of early weightbearing postoperative protocols after fixation of unstable ankle fractures.

Torsional Failure of Carbon Fiber Composite Plates Versus Stainless Steel Plates for Comminuted Distal Fibula Fractures

BACKGROUND

Carbon fiber composite implants are gaining popularity in orthopedics, but with few independent studies of their failure characteristics under supra-physiologic loads. The objective of this cadaveric study was to compare torsional failure properties of bridge plating a comminuted distal fibula fracture with carbon fiber polyetheretherketone (PEEK) composite and stainless steel one-third tubular plates.

METHODS

Comminuted fractures were simulated in 12 matched pairs of fresh-frozen human fibulas with 2-mm osteotomies located 3 cm proximal to the tibiotalar joint. Each fibula pair was randomized for fixation and implanted with carbon fiber and stainless steel 5-hole one-third tubular plates. The constructs were loaded in external rotation at a rate of 1-degree/sec until failure with a materials testing system. Torsional stiffness and mode of failure, as well as displacement, torque, and energy absorption for the first instance of failure and peak failure, were determined. Statistical analysis was performed with paired t tests and chi-square.

RESULTS

There were no significant differences among the 12 pairs for torsional stiffness, first failure torque, peak failure displacement, peak failure torque, or peak failure energy. Stainless steel plates exhibited significantly higher displacement (P < .001) and energy absorption (P = .001) at the first indication of failure than the carbon fiber plates. Stainless steel plates permanently deformed significantly more often than the carbon fiber plates (P = .035). Carbon fiber plates exhibited no plastic deformation with delamination of the composite, and brittle catastrophic failure in 1 specimen.

CONCLUSIONS

In a comminuted human fibula fracture fixation model, carbon fiber implants exhibited multiple pre-peak failures at significantly lower angles than the first failure for the stainless steel implants, with some delamination of composite layers and brittle catastrophic failure rather than plastic deformation.

CLINICAL RELEVANCE

The torsional failure properties of carbon fiber composite one-third tubular plates determined in this independent study provide novel in vitro data for this alternative implant material.

Reducing Fracture Risk Adjacent to a Plate With an Angulated Locked End Screw

OBJECTIVES

Locking screws often are used in the treatment of osteoporotic fractures. Studies show that locking screws can increase bone stresses at the plate end, which increases the possibility of peri-implant fracture. This study evaluates whether the technique used to insert the end screw is related to the fracture tolerance adjacent to the plate.

METHODS

Twelve groups of plate constructs were evaluated using a fibular diaphyseal surrogate with mechanical properties similar to osteoporotic bone. All inboard screws were nonlocked with only the end screw fixation differing among groups. The end screws were inserted either perpendicularly to the plate or at an angle of 30 degrees for 6- and 12-hole plates. For both orientations, the end screws were inserted nonlocked, locked, or by a locked overdrilling technique, resulting in 6 groups per plate length. The perpendicular nonlocked screws represented a control group. The constructs were tested to failure in 4-point bending to determine peak load, failure energy, and stiffness.

RESULTS

All constructs failed by peri-implant fracture along a plane through the 2 cortical holes of the end screw. Compared with the control group, an angulated locked screw at the plate end significantly increased the peak bending moment and energy required to produce a fracture for both plate lengths (6-hole, P = 0.008, P < 0.001; 12-hole, P = 0.006, P < 0.001).

CONCLUSIONS

The use of an angulated locked end screw may enhance the resistance of osteoporotic bone to peri-implant fractures caused by bending forces.

A Biomechanical Comparison of Locking Versus Conventional Plate Fixation for Distal Fibula Fractures in Trimalleolar Ankle Injuries

Previous biomechanical studies have advocated the use of locking plates for isolated distal fibula fractures in osteoporotic bone. Complex rotational ankle injuries involve an increased number of fractures, which can result in instability, potentially requiring the same fixed angle properties afforded by locking plates. However, the mechanical indication for locking plate technology has not been tested in this fracture model. The purpose of the present study was to compare the biomechanical properties of locking and conventional plate fixation for distal fibula fractures in trimalleolar ankle injuries. Fourteen (7 matched pairs) fresh-frozen cadaver leg specimens were used. The bone mineral density of each was obtained using dual x-ray absorptiometry scans. The fracture model simulated an OTA 44-B3.3 fracture. The syndesmosis was not disrupted. Each fracture was fixated in the same fashion, except for the distal fibula plate construct: locking (n = 7) and one-third tubular (n = 7). The specimens underwent axial and torsional cyclic loading, followed by torsional loading to failure. No statistically significant differences were found between the locking and conventional plate constructs during both fatigue and torque to failure testing (p > .05). Our specimen bone mineral density averages did not represent poor bone quality. The clinical implication of the present study is that distal fibular locking plates do not provide a mechanical advantage for trimalleolar ankle injuries in individuals with normal bone density and in the absence of fracture comminution.

Ankle fractures in the elderly: an overlooked burden

Ankle fractures in the elderly are a complex under-recognized burden which require a multidisciplinary approach to management. This article discusses the holistic approach required, including the up-to-date surgical management options and the areas for future development.

Fixation of distal fibula fractures: an update

Level of Evidence:

Level V, expert opinion.

Biomechanical comparison of a lateral polyaxial locking plate with a posterolateral polyaxial locking plate applied to the distal fibula

BACKGROUND

Polyaxial locking plates are becoming popular for the fixation of distal fibula fractures. This study establishes how construct stiffness and plate loosening, measured as range of motion, differs between lateral and posterolateral plate location.

METHODS

Seven matched pairs of cadaver fibulae were osteotomized in standardized fashion to produce a Weber type B distal fibula fracture. The fragments were fixated with an interfragmentary lag screw and polyaxial locking plates, with one fibula in each pair receiving a posterolateral anti-glide-plate, and the other a lateral neutralization-plate. In a biomechanical test, the bending and torsional stiffnesses of the constructs and the ranges of motion (ROM) were measured and subjected to a paired comparison.

RESULTS

The laterally plated group had a higher median (interquartile range) bending stiffness (29.2 (19.7) N/mm) and a smaller range of motion (2.06 (1.99) mm) than the posterolaterally plated group (14.6 (20.6) N/mm, and 4.11 (3.28) mm, respectively); however, the results were not statistically significant (pbending=0.314; pROM=0.325). Similarly, the torsional stiffness did not differ significantly between the two groups (laterally plated: 426 (259) Nmm/°; posterolaterally plated: 248 (399) Nmm/°; ptorsion=0.900). The range of motion measurements between the two groups under torsional loading were also statistically insignificant (laterally plated: 8.88 (6.30) mm; posterolaterally plated: 15.34 (12.64) mm; pROM=0.900).

CONCLUSION

In biomechanical cadaver-model tests of Weber type B fracture fixation with polyaxial locking plates, laterally plated constructs and posterolaterally plated constructs performed without significantly difference. Therefore, other considerations, such as access morbidity, associated injuries, patient anatomy, or surgeon's preference, may guide the choice of plating pattern. Further clinical studies will be needed for the establishment of definitive recommendations.

CLINICAL RELEVANCE

Information on the behavior of polyaxial locking plates is relevant to surgeons performing internal fixation of distal fibula fractures.

Topical review: locking plate technology in foot and ankle surgery

The use of locking plate technology in foot and ankle surgery has increased over the last decade. Reported applications include fracture repair, deformity correction, and arthrodesis. There is limited evidence, however, to guide clinicians with regard to the appropriate and optimal use of this technology. This work aims to examine the current biomechanical and clinical evidence comparing locking construct technology to other forms of fixation in the field of foot and ankle surgery.