Flexible Fixation and Fracture Healing: Do Locked Plating ‘Internal Fixators’ Resemble External Fixators?

Fractures resulting in impaired healing can be treated with mechanical stimulation via external fixators. To examine the effect of mechanical stimulation on fracture healing, we developed an external fixator for use in a mouse model. A 0.5 mm tibial osteotomy was stabilized with the external fixator in C57BL/6 mice. Osteotomies in the treatment group (nt = 41) were subjected to daily sessions of 150 μm of controlled displacement with the aim to create a more mineralized callus at 21 days compared with the control group (nc = 39). Qualitative assessment of the histology found no notable difference in healing patterns between groups at 7, 12, 17, and 21 days. At 21 days, micro-computed tomography (CT) analysis showed that the control group had a significantly higher bone volume (BV) fraction and trabecular number compared with treatment; however there was no significant difference in the total volume (TV) of the callus or trabecular thickness between groups. In summary, the external fixator was used with a motion application system to apply controlled displacement to a healing fracture; however, this treatment did not result in a more mineralized callus at 21 days.

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Locally-developed External Fixators as Definitive Treatment of Open Tibia Diaphyseal Fractures: A Clinical Prospective Study Conducted in Ivory Coast

10.21203/rs.3.rs-116154/v1 ◽

2020 ◽

Author(s):

Kouamé Jean-Eric Kouassi ◽

Jean Régis Akobé ◽

Aya Adélaïde Natacha Kouassi ◽

Loïc Founkoué ◽

Christine Detrembleur ◽

...

Keyword(s):

Fracture Healing ◽

External Fixator ◽

Ivory Coast ◽

Definitive Treatment ◽

External Fixators ◽

Negative Consequences ◽

Clinical Trial Registry ◽

Septic Complications ◽

Non Union ◽

Diaphyseal Fractures

Abstract Background: This study sought to evaluate the effectiveness of locally-developed external fixators (LDEF) as definitive treatment for open tibia diaphyseal fractures (OTDF) in Ivory Coast.Methods: Gustilo I, II and IIIA OTDFs of patients admitted within 24 hours of injury were prospectively included and treated with a locally-developed external fixator. The rates of union, mal-union, septic complications, as well as the functional results were assessed, in addition to the LDEF construct’s integrity. Predictive factors of failure or poor results were assessed.Results: Overall, 40 OTDF patients were admitted within 24 hours of injury. Gustilo I, II and IIIA fractures were observed in three, 13, and 24 patients, respectively. Uneventful fracture healing was obtained in 29 cases, with an average union time of 8.47 months. Mal-union and non-union were registered in three and four cases, respectively. Pin-track infection (PTI) was observed in 13 cases, and deep infection in seven. Infection resolved in all patients except four, who developed chronic osteomyelitis. None of the non-unions were associated with an infection. The overall functional result was satisfactory in 32 patients. PTI was the only predictive factor for chronic infection. Biplanar frames, when compared to monoplanar constructs, were associated with a significantly improved functional outcome.Conclusion: In comparison with the results obtained in the same environment without a locally-developed external fixator, the provision of such a device improved significantly the OTDF management, as it provided better stability and superior fracture healing rates. PTI remains an essential problem but with, hopefully, limited negative consequences. Trial registration: This study protocol was registered in Pan African Clinical Trial Registry under N°PACTR202009854874448. Date of registration 28 September 2020 ‘retrospectively registered’. www.pactr.org.

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Biomechanics of Subcutaneous Locked Plating vs Burke Plate and External Fixator for Comminuted Distal Radius Fractures

10.21203/rs.3.rs-94004/v1 ◽

2020 ◽

Author(s):

Andrew Pytiak ◽

Xin Jin ◽

Zlatan Cizmic ◽

Austen Washington ◽

Rahul Vaidya

Keyword(s):

Distal Radius ◽

External Fixator ◽

Compressive Loading ◽

Distal Radius Fractures ◽

External Fixators ◽

Radius Fractures ◽

Locked Plating ◽

Plating Technique ◽

Bridge Plate ◽

Tract Infections

Abstract Background: External fixators that span the wrist have been the historical norm in treating distal radius fractures. We have modified a dorsal distraction approach by using a subcutaneously applied locked bridge plate through 2 small incisions superficial to the extensor tendons and outside the extensor compartment. The purpose of this study was to biomechanically evaluate this modified method of fixation for comminuted distal radius fractures in comparison with two established constructs. Methods: Matched cadaver specimens were used to model an AO Type 23-C3 distal radius fracture. Biochemical testing for stiffness during axial compressive loading was done on three constructs: a conventional Burke distraction plate, the subcutaneous internal fixation plating technique and an external fixator. All specimens were cyclically loaded for 3000 cycles and then retested. Results: The modified construct was found to be stiffer than the external fixator (p=0.013). When compared to the Burke plate, the modified construct was significantly less stiff before axial cycling (p=0.025). However, the difference was not maintained after cycling and the post-axial loading stiffness difference was non-significant (p=0.456).Conclusion: Our data demonstrate the biomechanical integrity of the subcutaneous plating technique for the fixation of comminuted distal radius fractures. It is stiffer than an external fixator and has the theoretical advantage of avoiding pin-tract infections. In addition, it is subcutaneous, and not a cumbersome external construct. Our construct is minimally invasive and does not violate the dorsal extensor compartments allowing movement of the fingers while the construct is in place.

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Smart bone plates can monitor fracture healing

10.1101/366039 ◽

2018 ◽

Author(s):

Monica C. Lin ◽

Diane Hu ◽

Meir Marmor ◽

Safa T. Herfat ◽

Chelsea S. Bahney ◽

...

Keyword(s):

Fracture Healing ◽

Electrical Impedance ◽

Clinical Decision Making ◽

Bone Fractures ◽

Equivalent Circuit Model ◽

Electrical Impedance Spectroscopy ◽

Bone Plates ◽

External Fixators ◽

Fracture Management ◽

Fracture Models

One Sentence SummaryElectrical impedance measurements using microscale sensors implanted in two mouse fracture models tracked longitudinal differences between individual mice with proper healing and mice experiencing poor healing, laying the groundwork for translation to the clinic through integration into fracture fixation implants (i.e. instrumented bone plates).AbstractThere are currently no standardized methods for monitoring fracture healing. While histological studies can clearly identify the tissues found in the four stages of repair, in practice surgeons rely on X-ray, which is only useful at later stages of healing after mineralization has occurred. As electrical impedance spectroscopy (EIS) has previously been used to distinguish tissue types during healing, we hypothesized that microscale sensors embedded in the fracture callus could track the changing tissue with high sensitivity. Using in vivo mouse fracture models, we present the first evidence that microscale instrumented implants provide a route for post-operative fracture monitoring. In this study, we implanted sensors in mouse long bone fractures fixed with either external fixators or bone plates. EIS measurements taken across two electrodes implanted in the fracture gap were able to track longitudinal differences between individual mice with proper healing and mice experiencing poor healing. We additionally present an equivalent circuit model that combines the EIS data in order to classify healing states of fractures. Lastly, we show that EIS measures are strongly correlated with standard µCT measures of healing and that these correlations validate clinically-relevant operating frequencies for implementation of this technique. The data from these two models demonstrate that this technique can be translated to the clinic through integration into current fracture management strategies such as bone plating, providing physicians with quantitative information about the state of a fracture to guide clinical decision-making for patients.

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Fracture healing following high energy tibial trauma: Ilizarov versus Taylor Spatial Frame

Annals of The Royal College of Surgeons of England ◽

10.1308/003588414x13824511650335 ◽

2014 ◽

Vol 96 (2) ◽

pp. 106-110 ◽

Cited By ~ 7

Author(s):

CU Menakaya ◽

AS Rigby ◽

Y Hadland ◽

E Barron ◽

H Sharma

Keyword(s):

Fracture Healing ◽

High Energy ◽

Healing Time ◽

Tibial Fractures ◽

Taylor Spatial Frame ◽

External Fixators ◽

Consecutive Series ◽

Spatial Frame ◽

Ilizarov Frame ◽

Significant Difference

Introduction The optimal treatment of high energy tibial fractures remains controversial and a challenging orthopaedic problem. The role of external fixators for all these tibial fractures has been shown to be crucial. Methods A five-year consecutive series was reviewed retrospectively, identifying two treatment groups: Ilizarov and Taylor Spatial Frame (TSF; Smith & Nephew, Memphis, TN, US). Fracture healing time was the primary outcome measure. Results A total of 112 patients (85 Ilizarov, 37 TSF) were identified for the review with a mean age of 45 years. This was higher in women (57 years) than in men (41 years). There was no significant difference between frame types (p=0.83). The median healing time was 163 days in both groups. There was no significant difference in healing time between smokers and non-smokers (180 vs 165 days respectively, p=0.07), open or closed fractures (p=0.13) or age and healing time (Spearman's r=0.12, p=0.18). There was no incidence of non-union or re-fracture following frame removal in either group. Conclusions Despite the assumption of the rigid construct of the TSF, the median time to union was similar to that of the Ilizarov frame and the TSF therefore can play a significant role in complex tibial fractures.

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Clinical effects of dynamic stabilization with far cortical locking system in the treatment of simple distal-third tibia fractures: A cohort study

10.21203/rs.2.20315/v1 ◽

2020 ◽

Author(s):

Jing Peng ◽

Jun Fan ◽

Yang Li ◽

Xiaotao Long ◽

Shiyang Chen ◽

...

Keyword(s):

Cohort Study ◽

Fracture Healing ◽

Operative Time ◽

Callus Formation ◽

Weight Bearing ◽

Full Weight Bearing ◽

Control Group ◽

Fracture Union ◽

Locked Plating ◽

Tibia Fractures

Abstract Background: Locked plating constructs provided rigid fixation and may suppress callus formation at the fracture site, while far cortical locking (FCL) constructs have been shown to reduce the stiffness, thereby promoting fracture healing. A few publications have demonstrated that FCL construct increased axial dynamization and improved fracture healing. However, it is unclear whether the FCL construct was superior over locked plating construct for treating simple tibia fractures. Thus, we aimed to compare the clinical effect of FCL construct and locked plating construct for these fracture types.Methods: We retrospectively analyzed 18 patients treated with locked plating (control group) and 22 patients treated with the FCL construct (FCL group) from January 2016 to January 2018; the simple distal-third tibia fractures were included (AO/OTA classification: 42A1-A3 or 43A1). Patients were followed up regularly at 1, 2, 3, 6, and 12 months postoperatively, and data from clinical and radiological examinations were obtained. Patients’ demographics, operative time, time to radiological fracture union, time to full weight bearing, callus index, radiographic union score in tibia (RUST), and surgery-related complications were analyzed between the two groups.Results: The baseline patients’ demographics were similar between the two groups (P>0.05). There were no significant differences in of the operative time, time to radiological fracture union, or time to full weight bearing (P>0.05). However, the median callus index was 1.15 (IQR=1.08–1.25) in the FCL group and 1.09 (IQR=1.00–1.14) in the control group, showing a significant difference between the two groups (Z=-2.35, P<0.05), and the RUST was significantly higher at 2 months postoperatively (6.50±0.92 vs 7.59±1.37, P =0.006). Seven out of 18 patients in the control group and 2 out of 22 patients in the FCL group had no callus formation (callus index=1.0). All patients ultimately healed, and the complication rates were similar between the two groups.Conclusions : The FCL construct could promote fracture healing and was superior to locked bridge plating, as it did not lead to more surgery-related complications. Level of Evidence : Ⅲ, retrospective cohort study

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Preoperative Placement of Rigid Markers for the Treatment of Tibial Fractures Using 3D Printed External Repositioning Model Combined With External Fixator

10.21203/rs.3.rs-753353/v1 ◽

2021 ◽

Author(s):

Guoliang Li ◽

Jianyong Zhao ◽

Yadi Zhang ◽

Xuyang Wang ◽

Qilin Liu

Keyword(s):

Postoperative Complications ◽

Fracture Healing ◽

External Fixator ◽

Healing Time ◽

Tibial Fractures ◽

Control Group ◽

External Fixators ◽

Observation Group ◽

3D Printed ◽

Time Point

Abstract Purpose: To investigate the effectiveness of preoperative placement of a rigid marker 3D printed external repositioning model combined with an external fixation frame in patients with tibial fractures.Methods: Fifty-five patients with tibial fractures treated from June 2019 to August 2020 were used as study subjects. Patients were divided into a control group and an observation group according to the order of their admission to the hospital. Patients in the control group were treated with conventional surgery, and patients in the observation group were treated with preoperative placement of rigid markers 3D printed external repositioning models combined with external fixators. The treatment results of the two groups were compared.Results: Patients in the observation group had significantly shorter operative time, hospital stay and fracture healing time than patients in the control group, and intraoperative bleeding was significantly less than that in the control group (P<0.05). The pain level decreased in both groups as the time lengthened after surgery. At the same time point, the degree of pain in the observation group was significantly lower than that in the control group (P<0.05). The incidence of postoperative complications was 6.66% in the observation group and 36% in the control group, and the incidence of postoperative complications was significantly lower in the observation group than in the control group (P<0.05). The excellent rate of fracture healing was 60% in the observation group and 86.67% in the control group, and the difference in the excellent rate of fracture healing between the two groups was significant (P<0.05). Patients in both groups gradually recovered their knee and ankle functions after surgery with the extension of time. At the same time point, the HSS and Maryland scores of patients in the observation group were significantly higher than those in the control group (P<0.05).Conclusion：By using preoperative placement of rigid markers 3D printed external repositioning model combined with external fixator treatment. No further incision or fluoroscopic closed reduction is required. This reduces the patient's pain and improves the patient's fracture healing results.

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Theoretical Analysis of Fracture Healing Monitoring with External Fixators

Engineering in Medicine ◽

10.1243/emed_jour_1988_017_006_02 ◽

1988 ◽

Vol 17 (1) ◽

pp. 11-15 ◽

Cited By ~ 8

Author(s):

Kai-Nan An ◽

R. A. Kasman ◽

Edmund Y. S. Chao

Keyword(s):

Fracture Healing ◽

Monitoring System ◽

Healing Process ◽

Fracture Site ◽

External Fixators ◽

The Finite Element Method ◽

Cross Sectional ◽

Component Failure ◽

Intact Bone ◽

Fixation Devices

A fracture healing monitoring system with external fixators was analysed using the finite element method. Pin displacement and side bar strain under axial and side loading were evaluated at various stages of simulated fracture healing. In general, a recovery of rigidity at the fracture site of up of 25 percent of intact bone could be sensitively predicted. Effects of cross-sectional distribution and length of callus at the fracture site on pin displacement and side bar strain were studied. Alterations of fixation configuration, such as component failure during the healing process, were found to have relatively little effect on pin displacement but a rather larger effect on side bar strain. In general, the assessment of fracture healing by monitoring the deformation of external fixation devices is a useful idea. However, in practice, great care must be taken to fully understand the implication of the monitoring system before drawing conclusions on such measurements.

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