Stiffness of the locking compression plate as an external fixator for treating distal tibial fractures: a biomechanics study

Non‑contact locking plate: A useful alternative to external fixation in second‑stage treatment of post‑traumatic tibial osteomyelitis

The treatment of infected tibial bone defects can be challenging for the orthopedic surgeon. Therefore, the aim of the present study was to compare the fixation endurance, bone union time, lower limb joint function and complications associated with different fixation methods in the treatment of bone defects caused by debridement in the treatment of post-traumatic osteomyelitis. The clinical data of 55 patients with infected bone defects of the lower extremities following traumatic injury, who had undergone radical debridement between January 2017 and September 2020, were retrospectively analyzed. The patients were divided into three groups according to the type of fixation during reconstruction, namely the external fixation (EX), internal fixation (IX) and non-contact locking plate (LP) groups. The demographic data, time to bone union, bacterial culture results, complications and Self-Rating Anxiety Scale (SAS) scores of the patients were compared among the three groups. The results indicated that the differences in time to bone union and recurrence rates of osteomyelitis among the three groups were not statistically significant. By contrast, functional status after surgery was significantly higher in the LP group compared with the EX group. In total, 8/22 patients (36.4%) in the EX group, 4/13 patients (30.8%) in the IX group and 4/20 patients (20.0%) in the non-contact LP group had shortened limbs and deformed tibia. The SAS assessment results revealed that patients in the non-contact LP group had the lowest rates of moderate and severe anxiety. In conclusion, the results of the present study demonstrate that the non-contact locking plate technique provided stable fixation without any contact between the implant and bone tissues. Therefore, this technique may be viable for use during the reconstruction stage of post-traumatic tibial osteomyelitis.

Effect of Plate-Bone Distance and Working Length on 2.0-mm Locking Construct Stiffness and Plate Strain in a Diaphyseal Fracture Gap Model: A Biomechanical Study

OBJECTIVE

 The aim of this study was to determine the effect of plate-bone distance (PBD) and working length on 2.0-mm locking compression plate (LCP) stiffness and strain in four-point bending and torsion in a diaphyseal fracture gap model.

STUDY DESIGN

 A total of 54 LCP with three screws per fragment were assigned to one of nine combinations of working length (WL; short, medium, and long), and PBD (1, 1.5, and 3 mm) for a sample size of six per construct configuration. Stiffness was measured under quasistatic, nondestructive four-point compression bending and torsion. Plate surface strain was recorded using three-dimensional (3D) digital image correlation during four-point compression bending.

RESULTS

 WL had a significant effect on overall construct stiffness in both compression bending and in torsion, with shorter WL constructs having higher stiffness (p < 0.0001). PBD had no effect on construct stiffness in compression bending; however, a significant reduction in stiffness was noted in torsion (p = 0.047) as PBD incrementally increased. WL had a significant effect on plate strain in compression bending, with shorter WL constructs having lower plate strain (p < 0.0001). PBD had no effect on plate strain in compression bending except for lower plate strain recorded in long WL constructs with 1-mm PBD, compared with 1.5- and 3-mm PBD constructs (p < 0.0001).

CONCLUSION

 Longer WL constructs, regardless of PBD, had lower stiffness in compression bending, while in torsion, some modulation of this effect was noted with incremental decreases in PBD. Longer WL resulted in high plate strain, regardless of PBD.

Comparative analysis of external locking plate and combined frame external fixator for open distal tibial fractures: a comprehensive assessment of clinical outcomes and financial implications

BACKGROUND

Open distal tibial fractures pose significant challenges regarding treatment options and patient outcomes. This retrospective single-centre study aimed to compare the stability, clinical outcomes, complications, and financial implications of two surgical interventions, namely the external locking plate and the combined frame external fixator, to manage open distal tibial fractures.

METHODS

Forty-four patients with distal open tibial (metaphyseal extraarticular) fractures treated between 2020 and 2022 were selected and formed into two main groups, Group A and Group B. Group A (19 patients) are patients that underwent treatment using the external locking plate technique, while Group B (25 patients) received the combined frame external fixator approach. Age, gender, inpatient stay, re-operation rates, complications, functional recovery (measured by the Johner-Wrush score), pain ratings (measured by the Visual Analogue Scale [VAS]), and cost analyses were evaluated for each group. Statistical analyses using SPSS were conducted to compare the outcomes between the two groups.

RESULTS

The research found significant variations in clinical outcomes, complications, and cost consequences between Group A and Group B. Group A had fewer hospitalisation periods (23.687.74) than Group B (33.5619.47). Re-operation rates were also considerably lower in Group A (26.3%) than in Group B (48%), owing to a greater prevalence of pin-tract infections and subsequent pin loosening in the combination frame external fixator group. The estimated cost of both techniques was recorded and analysed with the locking average of 26,619.69 ± 9,602.352 and the combined frame average of 39,095.64 ± 20,070.077.

CONCLUSION

This study suggests that although the two approaches effectively manage open distal tibia fractures, the locking compression plate approach (Group A) has an advantage in treating open distal tibia fractures. Shorter hospitalisation times, reduced re-operation rates, and fewer complications will benefit patients, healthcare systems, and budget allocation. Group A's functional recovery results demonstrate the locking plate technique's ability to improve recovery and patient quality of life. According to the cost analysis, the locking plate technique's economic viability and cost-effectiveness may optimise healthcare resources for open distal tibia fractures. These findings might improve patient outcomes and inform evidence-based orthopaedic surgery.

The Influence of Sagittal Pin Angulation on the Stiffness and Pull-Out Strength of a Monolateral Fixator Construct

Monolateral pin-to-bar-clamp fixators are commonly used to stabilize acute extremity injuries. Certain rules regarding frame geometry have been established that affect construct stability. The influence of sagittal pin angulation on construct stiffness and strength has not been investigated. The purpose of this biomechanical study was to demonstrate the effect of a pin angulation in the monolateral fixator using a composite cylinder model. Three groups of composite cylinder models with a fracture gap were loaded with different mounting variants of monolateral pin-to-bar-clamp fixators. In the first group, the pins were set parallel to each other and perpendicular to the specimen. In the second group, both pins were set convergent each in an angle of 15° to the specimen. In the third group, the pins were set each 15° divergent. The strength of the constructions was tested using a mechanical testing machine. This was followed by a cyclic loading test to produce pin loosening. A pull-out test was then performed to evaluate the strength of each construct at the pin-bone interface. Initial stiffness analyses showed that the converging configuration was the stiffest, while the diverging configuration was the least stiff. The parallel mounting showed an intermediate stiffness. There was a significantly higher resistance to pull-out force in the diverging pin configuration compared to the converging pin configuration. There was no significant difference in the pull-out strength of the parallel pins compared to the angled pin pairs. Convergent mounting of pin pairs increases the stiffness of a monolateral fixator, whereas a divergent mounting weakens it. Regarding the strength of the pin-bone interface, the divergent pin configuration appears to provide greater resistance to pull-out force than the convergent one. The results of this pilot study should be important for the doctrine of fixator mounting as well as for fixator component design.

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.

Single-Stage Externalized Locked Plating for Treatment of Unstable Meta-Diaphyseal Tibial Fractures

(1) Background: Unstable meta-diaphyseal tibial fractures represent a heterogeneous group of injuries. Recently, good clinical results have been reported when applying a technique of externalized locked plating in appropriate cases, highlighting its advantage in terms of less additional tissue injury compared with conventional methods of fracture fixation. The aims of this prospective clinical cohort study were, firstly, to investigate the biomechanical and clinical feasibility and, secondly, to evaluate the clinical and functional outcomes of single-stage externalized locked plating for treatment of unstable, proximal (intra- and extra-articular) and distal (extra-articular), meta-diaphyseal tibial fractures. (2) Methods: Patients, who matched the inclusion criteria of sustaining a high-energy unstable meta-diaphyseal tibial fracture, were identified prospectively for single-stage externalized locked plating at a single trauma hospital in the period from April 2013 to December 2022. (3) Results: Eighteen patients were included in the study. Average follow-up was 21.4 ± 12.3 months, with 94% of the fractures healing without complications. The healing time was 21.1 ± 4.6 weeks, being significantly shorter for patients with proximal extra- versus intra-articular meta-diaphyseal tibial fractures, p = 0.04. Good and excellent functional outcomes in terms of HSS and AOFAS scores, and knee and ankle joints range of motion were observed among all patients, with no registered implant breakage, deep infection, and non-union. (4) Conclusions: Single-stage externalized locked plating of unstable meta-diaphyseal tibial fractures provides adequate stability of fixation with promising clinical results and represents an attractive alternative to the conventional methods of external fixation when inclusion criteria and rehabilitation protocol are strictly followed. Further experimental studies and randomized multicentric clinical trials with larger series of patients are necessary to pave the way of its use in clinical practice.

Biomechanical study of the stiffness of the femoral locking compression plate of an external fixator for lower tibial fractures

BACKGROUND

A locking compression plate (LCP) of the distal femur is used as an external fixator for lower tibial fractures. However, in clinical practice, the technique lacks a standardized approach and a strong biomechanical basis for its stability.

METHODS

In this paper, internal tibial LCP fixator (Group IT-44), external tibial LCP fixator (Group ET-44), external distal femoral LCP fixator (Group EF-44, group EF-33, group EF-22), and conventional external fixator (Group CEF-22) frames were used to fix unstable fracture models of the lower tibial segment, and anatomical studies were performed to standardize the operation as well as to assess the biomechanical stability and adjustability of the distal femoral LCP external fixator by biomechanical experiments.

RESULTS

It was found that the torsional and flexural stiffnesses of group EF-44 and group EF-33 were higher than those of group IT-44 and group ET-44 (p < 0.05); the flexural stiffness of group EF-22 was similar to that of group IT-44 (p > 0.05); and the compressive stiffness of all three EF groups was higher than that of group ET-44 (p < 0.05). In addition, the flexural and compressive stiffnesses of the three EF groups decreased with the decrease in the number of screws (p < 0.05), while the torsional stiffness of the three groups did not differ significantly between the two adjacent groups (p > 0.05). Group CEF-22 showed the highest stiffnesses, while group ET-44 had the lowest stiffnesses (P < 0.05).

CONCLUSIONS

The study shows that the distal femoral LCP has good biomechanical stability and adjustability and is superior to the tibial LCP as an external fixator for distal tibial fractures, as long as the technique is used in a standardized manner according to the anatomical studies in this article.

Optimal Design and Biomechanical Analysis of a Biomimetic Lightweight Design Plate for Distal Tibial Fractures: A Finite Element Analysis

The treatment of fractures of the distal tibia can be problematic due to the insubstantial soft-tissue covering this part of the anatomy. This study investigates a novel strategy for minimally invasive plate osteosynthesis of distal tibia fractures called bionic lightweight design plating. Following the structure of the animal trabecular bone, we utilized topological mathematical methods to redesign the material layout of the internal fixation device to fulfill the desired lightweight design within given boundary conditions. The results showed that this method can maintain the same stability of the construct as the original plate after a reduction in the original volume by 30%, and the differences in strain energy of plates and maximum node displacement of constructs between the constructs [RP construct vs. LP construct] were not statistically significant (p > 0.05). In the safety assessment of the constructs, the peak stress of plates between constructs was found to not be statistically significantly different under a doubled physiological load (p > 0.05). The average stress of the plates’ elements exceeding the allowable stress was analyzed, and no statistically significant differences were found between the two constructs under axial compression stress conditions (p > 0.05). The average stress of the plates’ elements in the redesigned plating construct under torsional stress conditions was 3.08% less than that of the locked plating construct (p < 0.05). Under the double physiological load condition, 89% of the elements of the plate in the redesigned plating construct and 85% of the elements of the plate in the locked plating construct were lower than the maximum safe stress of the plate, which was 410 MPa (secondary allowable stresses). That reminds us the topology optimization offer a possible way to improve the capacity of soft tissue protection while ensuring the safety of the RP construct by reducing the volume of the implants.

Comparison between external locking plate fixation and conventional external fixation for extraarticular proximal tibial fractures: a finite element analysis

Background

Good clinical outcomes for locking plates as an external fixator to treat tibial fractures have been reported. However, external locking plate fixation is still generally rarely performed. This study aimed to compare the stability of an external locking plate fixator with that of a conventional external fixator for extraarticular proximal tibial fractures using finite element analysis.

Methods

Three models were constructed: (1) external locking plate fixation of proximal tibial fracture with lateral proximal tibial locking plate and 5-mm screws (ELP), (2) conventional external fixation of proximal tibial fracture with an 11-mm rod and 5-mm Schanz screws (EF-11), and (3) conventional external fixation of a proximal tibial fracture with a 7-mm rod and 5-mm Schanz screws (EF-7). The stress distribution, displacement at the fracture gap, and stiffness of the three finite element models at 30-, 40-, 50-, and 60-mm plate–rod offsets from the lateral surface of the lateral condyle of the tibia were determined.

Results

The conventional external fixator showed higher stiffness than the external locking plate fixator. In all models, the stiffness decreased as the distance of the plate–rod from the bone surface increased. The maximum stiffness was 121.06 N/mm in the EF-11 model with 30-mm tibia–rod offset. In the EF-7 model group, the maximum stiffness was 40.00 N/mm in the model with 30-mm tibia–rod offset. In the ELP model group, the maximum stiffness was 35.79 N/mm in the model with 30-mm tibia–plate offset.

Conclusions

Finite element analysis indicated that external locking plate fixation is more flexible than conventional external fixation and can influence secondary bone healing. External locking plate fixation requires the placement of the plate as close as possible to the skin, which allows for a low-profile design because the increased distance from the plate to the bone can be too flexible for bone healing. Further experimental mechanical model tests are necessary to validate these finite element models, and further biological analysis is necessary to evaluate the effect of external locking plate fixation on fracture healing.

An engineering review of external fixators

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Mechanical stability plays a key role in the effectiveness of external fixators.

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Strength and stiffness are the main factors which contributes towards stability.

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Modified configurations of linear, circular and hybrid fixators are investigated.

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Light weight composite materials are gradually replacing traditional metallic alloys.

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Existing research gaps in further optimizing external fixators are identified.

External Fixators are a common technique used to treat a variety of issues related to bones, predominantly due to its non-intrusive nature and versatility in terms of form and materials. While it is mainly used to treat open fractures, its other uses include limb lengthening, deformity correction, bone grafting, compression of non-unions and stabilization of dislocations. Its earliest use dates as far back as 400 BCE and has undergone significant improvements, focusing on both customization and optimization. These two aspects highlight the significance of complementing the orthopaedic requirements with engineering knowledge and its applications. Hence, this review paper aims to conduct an examination of recent developments of external fixators with a special focus on its structure, the usage of materials and biomechanical investigations using experimental and numerical techniques. The paper presents the existing level of engineering knowledge with regards to these aspects and identifies research gaps, which can improve the quality of the commonly used external fixators.

A comparative finite element simulation of locking compression plate materials for tibial fracture treatment

The locking compression plate (LCP) system has several advantages in fracture fixation combining angular stability with the use of locking screws with traditional fixation techniques. However, the system is complex and requiring careful attention to biomechanical principles and good surgical technique. Due to the set of complicate stresses and strains in the LCP system after implantation, the material, which is being used here, is deemed important. However, so far the materials have been limited to the stainless steel (SS) or titanium (Ti). This study was therefore aimed at investigate the biomechanical performance of the internal tibial locked plates at different material properties, including SS, Ti, carbon/polyether ether ketone (PEEK) composite, in treating medial tibial fracture using patient-specific finite element (FE) model of the human tibia. The carbon/PEEK composite materials were used at three different fiber plies configurations. Simulated loading was applied at 60:40 ratios on the medial:lateral aspect. The model was fixed distally in all degrees of freedom. The results revealed the highest stress (307.10 MPa) and the lowest strain (0.14%) at Ti LCP system. The carbon/PEEK LCP system at configuration I and III showed low stress (∼60 MPa) and high strain (0.70%), which are suitable points for designing of an internal LCP system. On the other hand, the highest value of stress in callus region was 4.78 MPa (Carbon PEEK/Configuration I) and the strain variations of callus region were between 1.46% and 3.82% among all materials. These results implied the advantage of carbon/PEEK composite materials in LCP system as they can tolerate higher strains at lower stresses.

Application of 3D-Printed Orthopedic Cast for the Treatment of Forearm Fractures: Finite Element Analysis and Comparative Clinical Assessment

Objective

This pilot study is aimed at investigating the mechanical characteristics of a cast-wrapped fractured forearm and performing a clinical comparative study of our own developed 3D-printed orthopedic cast.

Methods

An integrated finite element (FE) model including a forearm and a 3D-printed cast wrapping the forearm was created. The distal radial ulna in this model was cut through to mimic the bone fracture. A 400 N force and 1 Nm rotation moment, which were much larger than the loading conditions encountered in daily life for a human being, were applied on the palm. We conducted a comparative clinical study by using statistical assessment. 60 patients with forearm fractures were selected and treated with manual reduction and external fixation cast. All patients were divided into three groups with equal members (20): (a) 3D-printed external cast group, (b) traditional plaster external fixation group, and (c) splint external fixation group. The clinical efficacy, wrist function, and patient satisfaction were scored and compared.

Results

In the condition of 400 N loading, the fracture displacements in anterior-posterior (AP), posterior-anterior (PA), medial to lateral (ML), and lateral to medial (LM) compression directions were 1.2648, 1.3253, 0.8503, and 0.8957 (mm), respectively, and the corresponding fracture stresses were 4.5986, 3.9129, and 5.0334, 7.9197 (MPa), respectively. In the inward (IR) and outward (OR) rotations, the fracture displacements were both 0.02628 (mm), and the corresponding fracture surface stresses were 0.1733 and 0.1723 (MPa), respectively. In the clinical efficacy, wrist function, and patient comfort evaluation, the total scores of group A were both higher than those in groups B and C (P < 0.05).

Conclusion

A 3D-printed orthopedic cast was capable of exerting appropriate mechanical correction loads on specific areas to maintain optimal alignment of a fractured forearm and thus could achieve the favorable clinical efficacy and patient comfort.

Investigating the biomechanical function of the plate-type external fixator in the treatment of tibial fractures: a biomechanical study

Background

The design of an external fixator with the optimal biomechanical function and the lowest profile has been highly pursued, as fracture healing is dependent on the stability and durability of fixation, and a low profile is more desired by patients. The plate-type external fixator, a novel prototype of an external tibial fixation device, is a low profile construct. However, its biomechanical properties remain unclear. The objective of this study was to investigate the stiffness and strength of the plate-type external fixator and the unilateral external fixator. We hypothesized that the plate-type external fixator could provide higher stiffness while retaining sufficient strength.

Methods

Fifty-four cadaver tibias underwent a standardized midshaft osteotomy to create a fracture gap model to simulate a comminuted diaphyseal fracture. All specimens were randomly divided into three groups of eighteen specimens each and stabilized with either a unilateral external fixator or two configurations of the plate-type external fixator. Six specimens of each configuration were tested to determine fixation stiffness in axial compression, four-point bending, and torsion, respectively. Afterwards, dynamic loading until failure was performed in each loading mode to determine the construct strength and failure mode.

Results

The plate-type external fixator provided higher stiffness and strength than the traditional unilateral external fixator. The highest biomechanics were observed for the classical plate-type external fixator, closely followed by the extended plate-type external fixator.

Conclusions

The plate-type external fixator is stiffer and stronger than the traditional unilateral external fixator under axial compression, four-point bending and torsion loading conditions.

A novel adjustable locking plate (ALP) for segmental bone fracture treatment

A novel Ti6Al4V adjustable locking plate (ALP) is designed to provide enhanced bone stability for segmental bone fractures and to allow precise positioning of disconnected segments. The design incorporates an adjustable rack and pinion mechanism to perform compression, distraction and segment transfer during plate fixation surgery. The aim of this study is to introduce the advantages of the added feature and computationally characterize the biomechanical performance of the proposed design. Structural strength of the novel plate is analyzed using numerical methods for 4-point bending and fatigue properties, following ASTM standards. An additional mechanical failure finite element test is also conducted on the rack and pinion to reveal how much torque can be safely applied to the mechanism by the surgeon. Simulation results predict that the new design is sufficiently strong to not fail under regular anatomical loading scenarios with close bending strength and fatigue life properties to clinically used locking compression plates. The novel ALP design is expected to be a good candidate for addressing problems regarding fixation of multi-fragmentary bone fractures.

Can Preoperative 3D Printing Change Surgeon's Operative Plan for Distal Tibia Fracture?

This study aimed to determine if 3D printing can affect surgeon's selection of plate for distal tibia fracture surgery and to find out whether orthopedic surgeons consider this technology necessary and would use it in their practice. A total of 102 orthopedic surgeons were asked to choose anatomically contoured locking plates among 5 most commonly used types for one simple and one complex distal tibia fracture based on X-ray and CT images. Next, they were provided real-size 3D printed models of the same fractures, allowed to apply each of the 5 plates to these models, and asked if they would change their choice of plate. A 10-point numeric rating scale was provided to measure the extent of the help that 3D printing provided on preoperative planning. Finally, we asked the surgeons if they would use 3D printing in their practice. Seventy-four percent of inexperienced surgeons changed their selection of plate after using 3D printed models for the complex fracture. In contrast, only 9% of experienced surgeons changed their selection of plate for the simple fracture. Surgeons rated the extent of usefulness of the 3D models in preoperative planning as a mean of 4.84 ± 2.54 points for the simple fracture and 6.63 ± 2.54 points for the complex fracture. The difference was significant (p < 0.001). Eighty-six percent of inexperienced surgeons wanted to use 3D models for complex fractures. However, only 18% of experienced surgeons wanted to use 3D printed models for simple fractures. The use of a real-size 3D-printed model often changed surgeon's preoperative selection of locking plates, especially when inexperienced surgeons evaluated a complex fracture. However, experienced surgeons did not find 3D models very useful when assessing simple fractures. Future applications of 3D models should focus on training beginners in fracture surgery, especially when complex fractures are concerned.

A new classification and its value evaluation for intermediate column fractures of the distal radius

BACKGROUND

Intermediate column fractures of the distal radius (ICF) are fractures only or mainly limited to the lunate fossa of the distal radius. There are no classification systems and its value evaluation for ICF in the literature.

METHODS

According to the characteristics of ICF, ICF were divided into the volar, dorsal, split, collapse, and collapse with split types. Inter- and intra-observer agreements were analyzed with kappa statistics. Seventy-four patients with ICF were retrospectively studied from January 2008 to June 2016. Surgical approach and reduction-fixation method were taken under the guidelines of the classification in 54 patients with displaced fractures, while conservative treatment was taken in 16 patients with non-obvious displaced fractures and 4 patients with displaced fractures who declined surgery.

RESULTS

The inter- and intra-observer kappa coefficients were 0.875~0.925 and 0.900~0.950, respectively. All patients were followed up for 13~36 months (average, 18.4 months). At the last follow-up, according to Gartland and Werley score of the functional recovery of wrist, all except 3 patients had excellent or good results (the excellent and good rate was 95.95%).

CONCLUSION

The classification reflects the characteristics of ICF and may provide an important reference for choosing treatment and evaluating prognosis.

Lateral Subcutaneous Locking Compression Plate and Small Incision Reduction for Distal-third Diaphyseal Humerus Fractures

Objective

Iatrogenic radial nerve injury is a great challenge for orthopaedic surgeons who deal with distal‐third diaphyseal humerus fractures. Conventional open reduction and internal fixation (ORIF) remains the gold standard, but complications such as nonunion and iatrogenic radial nerve injury still occur. We fixed the fractures with a lateral locking compression plate (LCP) subcutaneously after small incision reduction to protect the radial nerve. This study reports the clinical and radiographic outcomes of our modified method.

Methods

Thirty‐eight patients with distal‐third diaphyseal humerus fractures were treated with lateral subcutaneous LCP and small incision reduction at our department between September 2013 and August 2016. There were 33 males and 5 females, with an average age of 30.3 years (range, 17 to 49 years). All the cases were types A or B (AO/OTA classification, type A, 24 cases; type B, 14 cases). Among them, 6 cases were combined with preoperative radial nerve palsy. All patients were diagnosed with closed humeral fractures after X‐ray examination, and had typical upper limb pain, swelling, and movement disorders. The operations were performed by a single surgeons’ team. Union time, range of motion (ROM), University of California, Los Angeles (UCLA) shoulder rating scale, and Mayo Elbow Performance Index (MEPI) scores were assessed to evaluate the postoperative results.

Results

All patients were followed up for an average of 11.4 months (range, 3 to 36 months). The average operation time was 75.5 min (range, 60 to 150 min) and average intraoperative radiation exposure was 10.5 s (range, 8 to 18 s). Bony union was achieved in all cases after an average of 16.2 weeks (range, 12 to 25 weeks). No complications such as infection or screw and plate fracture occurred, and no iatrogenic radial nerve injury was observed. According to the UCLA shoulder rating scale, the average score was 33.7 (range, 31 to 35), with 33 excellent (86.8%) and 5 good cases (13.2%). They were all excellent according to their MEPI scores (ranging, 94 to 100, with an average of 97.4). The average operation time for secondary removal of the plate was 15.2 min (range, 10 to 20 min), and no complications such as infection or secondary radial nerve injury occurred.

Conclusions

Lateral subcutaneous LCP and small incision reduction may reduce the risk of iatrogenic radial nerve injury significantly in the treatment of distal‐third diaphyseal humerus fractures. It also leads to solid fixation, good postoperative function, and convenient removal of the plate without injuring the radial nerve.

Locked plating as an external fixator in treating tibial fractures: A PRISMA-compliant systematic review

OBJECTIVES

This article is a systematic review of the published literature about the biomechanics, functional outcomes, and complications of a locked plate as an external fixator in treating tibial fractures.

METHODS

We searched the PubMed, Ovid Medline, Embase, ScienceDirect, and Cochrane Library databases to retrieve the relevant studies. Studies published in English and Chinese which assessed adult patients and more than 4 cases who had sustained any type of fresh tibial fracture treated with the external locking plate, provided that they reported functional outcomes, range of motion (ROM), union or complication rates, and the biomechanical studies of external locked plating are also included.

RESULTS

The electronic search strategy revealed 248 studies, and 2 studies were identified as relevant through manual search of references. Finally, 12 studies were included in this systematic review. These consist of 3 pure biomechanical studies, 8 case series, and 1 study including both of biomechanics and case series. Due to the heterogeneity of biomechanical studies, we can only conclude that external locked plate shows inferior structural stiffness than internal locked plate. The clinical studies reported that external locked plating gave a satisfactory ROM of the knee and ankle, functional outcomes, union rate, and low complication rate.

CONCLUSIONS

We can only conclude that external locked plate shows inferior structural stiffness than internal locked plate because of the heterogeneity of biomechanical studies. The clinical studies showed locked plating as an external fixator in treating tibial fractures can be considered as a safe and successful procedure. However, as yet, there is unconvincing evidence that it is superior to standard techniques with regards to clinical and functional outcomes. More and well-designed studies about this technique should be carried out.