Fracture Fixation Research Articles

Anterior internal versus external fixation of unstable pelvis fractures was not associated with discharge destination, critical care, length of stay, or hospital charges.

Determine if anterior internal versus supra-acetabular external fixation of unstable pelvic fractures is associated with care needs or discharge. A retrospective cohort study was performed at two tertiary trauma referral centers. Adults with unstable pelvis fractures (AO/OTA 61B/61C) who received operative fixation of the anterior and posterior pelvic ring by two orthopedic trauma surgeons from October 2020 to November 2022 were included. The primary outcome was discharge destination. Secondary outcomes included intensive care unit (ICU) or ventilator days, length of stay, and hospital charges. Eighty-three eligible patients were 38.6% female, with a mean age of 47.2 ± 20.3years and BMI 28.1 ± 6.4kg/m2. Fifty-nine patients (71.1%) received anterior pelvis internal fixation and 24 (28.9%) received external fixation. External fixation was associated with weight-bearing restrictions (91.7% versus 49.2%, p = 0.01). No differences in demographic, functional status, insurance type, fracture classification, or injury severity measures were observed by treatment. Internal versus external anterior pelvic fixation was not associated with discharge to home (49.2% versus 29.2%, p = 0.10), median ICU days (3.0 [interquartile range (IQR) 7.8 versus 5.5 [IQR 4.3], p = 0.14, ventilator days (0 [IQR 6.0] versus 0 [IQR 2.8], p = 0.51), length of stay (13.0 [IQR 13.0] versus 17.5 (IQR 20.5), p = 0.38), or total hospital charges (US dollars 180,311 [IQR 219,061.75] versus 243,622 [IQR 187,111], p = 0.14). Anterior internal versus supra-acetabular external fixation of unstable pelvis fractures was not significantly associated with discharge destination, critical care, hospital length of stay, or hospital charges. This sample may be underpowered to detect differences between groups. Therapeutic Level IV.

A novel anatomical locked medial femoral condyle plate: a biomechanical study.

Fixation with a distal lateral femoral plate is a standard approach in treating osteoporotic or comminuted supracondylar femur fractures. However, in clinical practice, this method may prove inadequate, necessitating the application of a plate on the medial side of the distal femur. The aim of this study is to perform a biomechanical evaluation of the newly manufactured anatomically locked plate applied to the distal medial femoral condyle. The plate underwent 2 biomechanical tests by simulating an AO/OTA 33A3 type supracondylar fracture model on synthetic femur bones. The samples were divided into three groups. Fracture fixations were carried out on the medial side using the distal femur medial anatomical locking plate (DFMALP) in group A samples, on the lateral side using the distal femur lateral anatomical locking plate in group B samples, and on both sides in group C samples. In the axial compression test, stability was preserved 23% more in group C than in group B. During the cyclic axial compression test, total displacement was 21% less in group C than in group B. Group A was collapsed at early cycle degrees. In our study, it was observed that the application of DFMALP in conjunction with the lateral plate in AO/OTA 33A3 fragmented supracondylar femur fractures significantly enhanced biomechanical fracture stability. This is a Level 2 prospective, randomized controlled study.

Head-to-neck screw fixation and radial head arthroplasty result in similar postoperative outcomes for low-comminuted radial head fractures with neck involvement

Background Fixation of radial head fractures with neck involvement presents challenges. It remains unclear whether the outcomes of head-to-neck screw fixation are similar to those of arthroplasty in this scenario. We conducted a retrospective cohort study to evaluate the clinical outcomes of these two methods for treating such fractures. Methods Demographic data, fracture type, number of fragments, and concomitant injuries were recorded. Range of motion, Visual Analogue Scale for pain, Mayo Elbow Performance Score, and Quick-Disabilities of the Arm, Shoulder, and Hand at three-year follow-up, complications, and reintervention were compared. Results A total of 14 patients underwent fixation with head-to-neck screws, and 15 an arthroplasty. Baseline characteristics between groups were similar ( P > .05). Satisfactory range of motion (arc > 100°) was achieved in nine patients (64%) in the fixation group, and eight patients (53%) in the arthroplasty group ( P = .55). The mean Visual Analogue Scale, Mayo Elbow Performance Score, and Quick-Disabilities of the Arm, Shoulder, and Hand were 1.2 ± 1.2, 91.7 ± 10.7, and 9.1 ± 1, respectively, ( P = .651, P = .651, and P = .155). Three patients (21%) in the fixation group underwent a reintervention and three (20%) in the arthroplasty group ( P = .639). Discussion Head-to-neck screw fixation and radial head arthroplasty result in similar postoperative outcomes for low-comminuted radial head fractures with neck involvement.

Clinical differences between periprosthetic and native distal femur fractures: a comparative observational study

IntroductionThe incidence of periprosthetic distal femur fractures (PDFF) is increasing as the number of total knee replacements becomes more common. This study compared the demographics, fracture characteristics, treatment, and outcomes of periprosthetic versus native distal femur fractures (NDFF).Materials and methodsThis was a retrospective cohort study of patients ≥ 18 who underwent surgical fixation of NDFF or PDFF from 2012 to 2020 at a level-1 trauma center. The main variables collected included demographics, AO/OTA fracture classification, fixation construct, concomitant fractures, polytrauma rates, bone density, and reduction quality. Primary outcomes were unexpected return to the operating room (UROR), hospital length of stay, and quality of reduction. T-tests, Fisher’s exact tests, and multivariate analyses were used for statistical analysis.Results209 patients were identified, including 70 PDFF and 139 NDFF. PDFF patients were elderly females (81%) with isolated (80%) and comminuted (85%) 33 A.3 (71%) fractures. NDFF patients included 53% females, were commonly middle-aged, and displayed comminuted (92%) 33 C.2 fractures. 48% of NDFF patients had concomitant fractures. Intramedullary nailing was the primary fixation for both groups, followed by nail-plate combination (37%) for PDFF and lateral locking plates (21%) for NDFF. NDFF patients experienced significantly longer hospital stays, higher UROR rates, and worse quality of reduction (p < 0.05). PDFF patients had a significantly greater prevalence of low bone density (p < 0.05).ConclusionPDFF occur as isolated injuries with significant metaphyseal comminution in elderly females with low bone quality. NDFF commonly occurs in younger patients with less metaphyseal comminution and concomitant fractures. Intramedullary nailing was the most common treatment for both groups, although preference for nail-plate combination fixation is increasing. NDFF type 33 C fractures are at greater risk of UROR.

Acetabular fractures in geriatric patients: epidemiology, pathomechanism, classification and treatment options.

The incidence of geriatric acetabular fractures has shown a sharp increase in the last decades. The majority of patients are male, which is different to other osteoporotic fractures. The typical pathomechanism generally differs from acetabular fractures in young patients regarding both the direction and the amount of force transmission to the acetabulum via the femoral head. Geriatric fractures very frequently involve anterior structures of the acetabulum, while the posterior wall is less frequently involved. The anterior column and posterior hemitransverse (ACPHT) fracture is the most common fracture type. Superomedial dome impactions (gull sign) are a frequent feature in geriatric acetabular fractures as well. Treatment options include nonoperative treatment, internal fixation and arthoplasty. Nonoperative treatment includes rapid mobilisation and full weighbearing under analgesia and is advisable in non- or minimally displaced fractures without subluxation of the hip joint and without positive gull sign. Open reduction and internal fixation of geriatric acetabular fractures leads to good or excellent results, if anatomic reduction is achieved intraoperatively and loss of reduction does not occur postoperatively. Primary arthroplasty of geriatric acetabular fractures is a treatment option, which does not require anatomic reduction, allows for immediate postoperative full weightbearing and obviates several complications, which are associated with internal fixation. The major issue is the fixation of the acetabular cup in the fractured bone. Primary cups, reinforcement rings or a combination of arthroplasty and internal fixation may be applied depending on the acetabular fracture type.

Surgical methods of treatment for tibial diaphyseal fractures

Background. Bone fractures are a public health concern. In recent years, there has been an upward trend in body weight of people of all age groups. Obesity has long been thought to help protect against fractures, but recent studies have shown that for every 5 cm increase in waist circumference, the risk of any fracture is 3 % higher. The purpose: according to the meta-analysis of modern medical literature, to determine the main directions of surgical treatment for long bone fractures, their advantages, and disadvantages, including in overweight patients, the features of diaphyseal fracture fixation in overweight patients. Materials and methods. A meta-analysis of special literature from scientific databases was conducted: Cochrane Library, Scopus, National Library of Medicine — National Institutes of Health, ReLAB-HS Rehabilitation Resources Repository. One hundred and thirty articles were analyzed, from them 31 were selected, which, in our opinion, reflect the purpose of the study. Results. All methods of surgical fixation of fractures have their advantages and disadvantages. The frequency of nonunions caused by intramedullary fixation of the femoral shaft can reach 10 %, and varus/valgus and rotational deformities and shortening can also be observed. But the use of locking screws prevents the occurrence of most complications. When fixing the fractures with plates, the main complications are related to superficial and deep infections, which were more often observed in overweight patients. The analysis demonstrated that in overweight and obese patients, the main complicating factor is not the method for fixing the fracture zone, but factors related to the health of the patient himself. So, despite the fact that the results of treatment of fractures in patients with normal weight and obesity did not have a statistically significant difference, an increase in cardiovascular complications, exacerbation of chronic respiratory diseases was observed. Moreover, it is the presence of concomitant diseases that often makes surgical intervention impossible. Conclusions. There is a large amount of research on surgical methods of fixing tibial diaphyseal fractures, but data on the choice of fixation method in overweight and obese patients as a separate approach were not found. There are data on complicating factors of excess weight in the treatment of fractures and surgical interventions. Systematic studies related specifically to the algorithm for choosing the method of fracture fixation and complications have also not been found.

Analysis of Eligibility of the S1 Corridor for the Trans-Sacral Screw Placement in Geriatric Patients

Abstract Background Minimal-invasive placement of a trans-sacral screw represents an increasingly popular method of fixation for Fragility Fractures of the Pelvis (FFP), with variable upper sacral anatomy representing the main challenge. Little is known about the variability of sacral anatomy in the geriatric population and the potential effect of osteoporosis on the upper sacral anatomy and thus S1 corridor morphology. Aims To examine the eligibility (&amp;gt;12 mm) of the S1 corridor for the trans-sacral screw placement in a geriatric population and to analyse what pelvic dysmorphism signs might serve as predictors for an ineligible S1 corridor. Methods We analysed S1 corridor in pelvic CT scans of 107 geriatric patients without history of fracture or other pelvic pathology. First, the eligibility for the trans-sacral screw placement was determined by measuring the width and the height of the central portion of the S1 corridor. Then, pelvises were examined for signs of dysmorphism. The correlation of these signs with the ineligible S1 corridor was analysed. Results In our geriatric population with average age of 79,55 ± 8.79 years (male : female 0.88) 44% of S1 corridors were not eligible for a trans-sacral screw. In this ineligible group the height was shown to be a more significant limiting dimension (90,9%), compared to the width in 68,2% (p&amp;lt;0.05). Mamillary processes, not recessed sacrum and dysmorphic sacral foramina were present in 38,3%, 34,6%, and 26,2% respectively, with not recessed sacrum demonstrating a significant correlation with a too narrow S1 corridor (p&amp;lt;0.05). Conclusion The analysed geriatric population demonstrates a high prevalence of a too narrow S1 corridor, which makes a placement of a trans-sacral screw risky or even impossible. The height of the S1 corridor represents the main limiting factor with a dysmorphism sign of a not recessed sacrum being a significant predictor for the ineligible S1 corridor.

EVALUATING SHORT-TERM OUTCOMES POST- INTRA-ARTICULAR CALCANEAL FRACTURE FIXATION VIA A SINUS TARSI APPROACH IN A NON-EXCLUSIVELY SELECTED COHORT

AimsManagement of intra-articular calcaneal fractures remains a debated topic in orthopaedics, with operative fixation often held in reserve due to concerns regarding perioperative morbidity and potential complications. The purpose of this study was to identify the characteristics of patients who developed surgical complications to inform the future stratification of patients best suited to operative treatment for intra-articular calcaneal fractures and those in whom surgery was highly likely to produce an equivocal functional outcome with potential post-operative complications.MethodsAll patients who underwent open reduction and internal fixation of calcaneal fractures utilizing the Sinus Tarsi approach between March 2014 and July 2018 were identified using theatre records. Patient imaging was used to assess pre- and post-operative fracture geometry with Computed Tomography (CT) used for pre-operative planning. Each patient's clinical presentation was established through retrospective analysis of medical records. Patients provided verbal consent to participation and patient reported outcome measures were recorded using the Maryland Foot Score.ResultsFifty-eight intra-articular calcaneal fractures (fifty-three patients including five bilateral, mean age = 46.91 years) were included. Forty-nine patients were injured as a result of a fall from a height (92.4%). Mean time from presentation to surgery was 3.23 days (range 0–21). Mean Maryland Foot score was found to be 77.6 (+/− 16.22) in forty-five patients. Five patients (9.4%) had wound complications; two superficial (3.7%) and three deep (5.6%).ConclusionIntra-articular fractures of the calcaneus should be considered for surgical intervention in order to improve long-term functional outcomes. The Sinus Tarsi approach provides the potential to decrease the operative complication rate whilst maintaining adequate fixation, however, the decision to surgically manage these fractures should be carefully balanced against the risk of post-operative complications. This increased risk of complication associated with smoking may tip the balance against benefit from surgical management.

Surgical treatment outcomes of acetabular posterior wall and posterior column fractures using 3D printing technology and individualized custom-made metal plates: a retrospective study

BackgroundFractures involving the posterior acetabulum with its rich vascular and neural supply present challenges in trauma orthopedics. This study evaluates the effectiveness of 3D printing technology with the use of custom-made metal plates in the treatment of posterior wall and column acetabular fractures.MethodsA retrospective analysis included 31 patients undergoing surgical fixation for posterior wall and column fractures of the acetabulum (16 in the 3D printing group, utilizing 3D printing for a 1:1 pelvic model and custom-made plates based on preoperative simulation; 15 in the traditional group, using conventional methods). Surgical and instrument operation times, intraoperative fluoroscopy frequency, intraoperative blood loss, fracture reduction quality, fracture healing time, preoperative and 12-month postoperative pain scores (Numeric Rating Scale, NRS), hip joint function at 6 and 12 months (Harris scores), and complications were compared.ResultsThe surgical and instrument operation times were significantly shorter in the 3D printing group (p < 0.001). The 3D printing group exhibited significantly lower intraoperative fluoroscopy frequency and blood loss (p = 0.001 and p < 0.001, respectively). No significant differences were observed between the two groups in terms of fracture reduction quality, fracture healing time, preoperative pain scores (NRS scores), and 6-month hip joint function (Harris scores) (p > 0.05). However, at 12 months, hip joint function and pain scores were significantly better in the 3D printing group (p < 0.05). Although the incidence of complications was lower in the 3D printing group (18.8% vs. 33.3%), the difference did not reach statistical significance (p = 0.433).ConclusionCombining 3D printing with individualized custom-made metal plates for acetabular posterior wall and column fractures reduces surgery and instrument time, minimizes intraoperative procedures and blood loss, enhancing long-term hip joint function recovery.Clinical Trial Registration12/04/2023;Trial Registration No. ChiCTR2300070438; http://www.chictr.org.cn.

New Generation Superior Single Plating versus Low-Profile Dual Mini-Fragment Plating of Diaphyseal Clavicle Fractures - A Biomechanical Study

Abstract Background Recently, a new generation of superior clavicle plates was developed featuring the variable-angle locking technology for enhanced screw positioning and optimized plate-to-bone fit design. On the other hand, mini-fragment plates used in dual plating mode have demonstrated promising clinical results. However, these two bone-implant constructs have not been investigated biomechanically in a human cadaveric model. Aims To compare the biomechanical competence of single superior plating using the new generation plate versus dual plating with low-profile mini-fragment plates. Methods Sixteen paired human cadaveric clavicles were assigned pairwise to two groups for instrumentation with either a 2.7 mm Variable Angle Locking Compression Plate placed superiorly (Group 1), or with one 2.5 mm anterior plate combined with one 2.0 mm superior matrix mandible plate (Group 2). An unstable clavicle shaft fracture AO/OTA15.2C was simulated by means of a 5 mm osteotomy gap. All specimens were cyclically tested to failure under craniocaudal cantilever bending, superimposed with bidirectional torsion around the shaft axis and monitored via motion tracking. Results Initial stiffness was significantly higher in Group 2 (9.28±4.40 N/mm) compared to Group 1 (3.68±1.08 N/mm), p=0.003. The amplitudes of interfragmentary motions in terms of craniocaudal and shear displacement, fracture gap opening, and torsion were significantly bigger over the course of 12500 cycles in Group 1 compared to Group 2; p≤0.038. Cycles to 2 mm shear displacement were significantly lower in Group 1 (22792±4346) compared to Group 2 (27437±1877), p=0.047. Conclusion From a biomechanical perspective, low-profile 2.5/2.0 dual plates demonstrated significantly higher initial stiffness, less interfragmentary movements, and higher resistance to failure compared to 2.7 single superior variable-angle locking plates and can therefore be considered as a useful alternative for diaphyseal clavicle fracture fixation especially in unstable fracture configurations.

FIBULAR NAILS: IS THIS THE ANSWER TO ANKLE FRACTURE FIXATION?

IntroductionPositive reports from implant designer centres on the use of fibular nails in the complex ankle fractures has resulted in a marked increase in their use nationally. Our aim in this study was to report on the outcomes of the use of all fibular nails in two major trauma centres.MethodsAll patients who underwent ankle fracture fixation using a fibular nail in two major trauma centres, were included for analysis. MTC 1 included patients from April 2013 to May 2015, and MTC 2 included patients February 2015 to March 2018. A minimum follow up of 1 year was achieved for all patients. Radiographic reduction was confirmed by Pettrones criteria at time of operation and at 6 weeks and 1 year post-operatively. Kellgren Lawrence radiographic criteria was used to classify osteoarthritis. All complications and further surgery were recorded.ResultsForty-four patients underwent fibular nail fixation in the two centres. The average age was 59 (range 21–91). Using Pettrones criteria, 86% were malreduced at time of operation. A further 34% deteriorated by at least 1 grade by 6 weeks and an additional 16% (n=7) deteriorated by at least 1 grade by 1 year. 57% had developed radiographic evidence of osteoarthritis by 1 year. Only 4.5% (2ankles) maintained complete reduction by 1 year. Other significant complications were reported in 43% of patients.ConclusionBoth major trauma centres report the same experience in the use of fibular nails for ankle fracture fixation. As previously reported in smaller number studies, initial reduction is challenging. Worryingly, the majority of well-reduced lose position with time. We suggest that the fibula nail is used with caution and as part of an appropriately approved audit.

Assessment of Safe Early Fixation Strategies in a Cohort Polytraumatized Patients – How is the Surgical Treatment Influenced by the Injury Pattern?

Abstract Background While the inital assessment and the intial treatment of potentially life-threatening injuries is well-described, the surgical treatment strategy following initial resuscitation remains controversial. Timepoint of surgery and type of surgery still reamin topic of discussions. Various, different strategies for optimal timing of fracture fixation in polytrauma patients exist. Aims This study tests the hypothesis that a concept of clearing patients for early definitive surgery that relies on anatomical and physiologic parameters is influenced by the injury distribution. Methods Polytrauma patients treated at a Level 1 trauma center (01.01.2016 - 31.12.2018). Inclusion: primary admission, injury severity score (ISS) ≥16points, requirement of surgical fixation of major extremity or a truncal injury. Exclusion: death &amp;lt;72h after admission, severe traumatic brain injury (TBI). Stratification according to surgical fixation concept: Early total care (ETC, all surgeries &amp;lt;24 h), safe definitive surgery (SDS, staged surgeries &amp;lt;72h), and damage control orthopaedics (DCO, definitive care after stabilization). Endpoints: mortality, complication rates. Parameters of interest: Injury severity and distribution (ISS/AIS), pathophysiologic parameters of hemorrhagic shock, coagulopathy, hypothermia, soft tissue trauma. Results 527 patients, mean age 54.8 SD19.9 years, mean ISS 26.9 SD9.0 points, mortality 20.5%. Group ETC (n=21, 3.9%), Group SDS (n = 284, 53.9%), Group DCO (n = 222, 42.1%). Abdominal and spinal injuries associated with ETC (AIS Abdomen; OR 2.1, 95%CI 1.1 to 4.0, p = 0.026: AIS Spine OR 2.0, 95%CI 1.2 to 3.4, p = 0.007). Extremity and pelvic injuries associated with SDS (OR 1.8, 95%CI 1.1 to 2.8, p = 0.012 and OR 1.3, 95%CI 1.0 to 1.7, p = 0.036), head injuries associated with DCO (OR1.5, 95%CI 1.3 to 1.8, p &amp;lt;0.001). Head injuries were most relevant for mortality and were associated with patients undergoing DCO (29.7%) (ETC; 23.8%, SDS; 13.0%). Conclusion The concept of staged early fixation for major extremity and axial injuries (SDS) was successfully applied in the majority of patients. Predominant head and abdominal injuries were associated with ETC or DCO. The injury distribution influences decision making towards surgical management that is associated with a low complication rate.

Effectiveness of Kirschner wire fixation for proximal phalangeal bone avulsion fracture caused by A2 circular trochlea injury of flexor digitorum tendon

To explore the mechanism, surgical method, and effectiveness of proximal phalangeal bone avulsion fracture caused by A2 circular trochlea injury of the flexor digitorum tendon. A retrospective analysis was conducted on the clinical data of 4 patients with proximal phalangeal bone avulsion fracture caused by A2 circular trochlea injury of flexor digitorum tendon admitted between May 2018 and September 2022. The patients were all male, the age ranged from 26 to 52 years, with an average of 33 years. The injured fingers included 1 case of middle finger and 3 cases of ring finger. The causes of injury were rock climbing of 2 cases and carrying heavy objects of 2 cases. Preoperative anteroposterior and lateral X-ray films and CT examination of the fingers showed a lateral avulsion fracture of the proximal phalanx, with a fracture block length of 15-22 mm and a width of 3-5 mm. The total active range of motion (TAM) of the injured finger before operation was (148.75±10.11)°. The grip strength of the middle and ring fingers was (15.50±2.88) kg, which was significantly lower than that of the healthy side (50.50±7.93) kg ( t=-8.280, P<0.001). The time from injury to operation was 2-7 days, with an average of 3.5 days. One Kirschner wire with a diameter of 1.0 mm was used for direct fixation through the fracture block, while two Kirschner wires with a diameter of 1.0 mm were used for compression fixation against the fracture block. The fracture healing was observed, and the TAM of the injured finger and the grip strength of the middle and ring fingers were measured. The finger function was evaluated according to the upper limb functional assessment trial standards of the Chinese Medical Association Hand Surgery Society. The incisions all healed by first intention after operation. All patients were followed up 6-28 months, with an average of 19 months. X-ray films showed that all avulsion fractures of proximal phalanx reached bony union, and the healing time ranged from 4 to 8 weeks, with an average of 4.6 weeks. At last follow-up, the grip strength of the middle and ring fingers was (50.50±7.76) kg, which significantly improved when compared with preoperative one ( t=-8.440, P<0.001). The TAM of the injured finger reached (265.50±2.08)°, and there was a significant difference when compared with preoperative one ( t=-21.235, P<0.001). According to the upper limb functional assessment trial standards of the Chinese Medical Association Hand Surgery Society, the finger function was all evaluated as excellent in 4 cases. Using Kirschner wire fixation through bone blocks and external compression fixation of bone blocks for treating proximal phalangeal bone avulsion fracture caused by A2 circular trochlear injury of the flexor digitorum tendon can achieve good effectiveness.

Fabricating high-performance biomedical PLLA/PVDF blend micro bone screws through in situ structuring of oriented PVDF submicron fibers in microinjection molding

Poly(l-lactide) (PLLA) is regarded as a polymer with excellent biocompatibility, but its inherent brittleness property greatly restricts its application in the biomedical engineering field. Blending PLLA with other polymers is one of the sufficiently viable methods of property improvement. In this paper, the Poly(l-lactide) (PLLA)/Polyvinylidene fluoride (PVDF) blend was first prepared by melt-compounding, and then microinjection molded into the blend micro bone screw with high strength and toughness. The experimental results show that the PVDF dispersed phases could in situ form the highly oriented fibers with shish-kebab structures under the effect of strong shear stress field of microinjection molding along flow direction. These parallelly aligning PVDF fibers could simultaneously realize the significant enhancement in both toughness and strength of the micro bone screw. Specifically, in the bending test the blend micro bone screw with oriented PVDF fibers can withstand the compression displacement of nearly 2 mm, while the neat PLLA one would break within only 0.5 mm displacement. In addition, a bending recovery phenomenon was observed in the load-displacement curve of the blend, demonstrating the mechanical transition from brittle fracture to ductile fracture. Moreover, with addition of 30 % PVDF, the elongation at break increases from 7.8 % to 57.8 %, while the tensile strength increases from 60.9 MPa to 74.3 MPa. The PLLA/PVDF micro screws possess better toughness and excellent biocompatibility compared to pure PLLA products. They also exhibit great potential for stimulating the proliferation of cells through piezoelectric output, opening up new possibilities for the development of next-generation fracture fixation materials.

Auxetic fixation devices can achieve superior pullout performances compared to standard fixation concepts

Despite bone screws being the most commonly inserted implant in orthopaedic surgery, 10% of fracture fixation failure is a result of screw migration or pullout. In this study, the effect of four auxetic structures on the pullout performance of a novel unthreaded bone fastener was investigated through experiments and numerical simulations. The auxetic fasteners included the re-entrant, rotating squares, missing rib, and tetrachiral structures. Parametric CAD models were developed for each, and polymer samples manufactured using a stereolithography process. Pullout testing using bone analogue material found the rotating squares fastener to achieve superior pullout resistance 2.5 times that of the non-auxetic control sample. With a pullout to push-in force ratio of 33.7, this fastener achieved high pullout resistance with a low insertion force improving ease of installation. The Poisson’s ratio of the structure was determined using image analysis to be −1.31, similar to the missing rib and re-entrant types. The low axial stiffness of 12.1 N mm−1 for the rotating squares fastener was the reason for superior performance, allowing axial and resulting transverse strain to be initiated at relatively low load. The effect of increased diametral interference was investigated, and the re-entrant structure found to be superior with pullout resistance improved by 342%. This work provides a foundation for further development of unthreaded auxetic bone fasteners, which have the potential to replace screws for some orthopaedic applications and significantly reduce the prevalence of pullout as a failure mode.

Does the Subtalar or Tibiotalar Joint Need Fused in Primary Retrograde Tibiotalocalcaneal Nailing for Fragility Ankle Fractures?

As an alternative to traditional open reduction internal fixation of ankle fragility fractures, primary retrograde tibiotalocalcaneal (TTC) nailing has been investigated as a treatment option. These results suggest that this treatment is an acceptable alternative treatment option for these injuries. There are still questions about the need for formal joint preparation at the subtalar or tibiotalar joint when performing primary TTC nailing for fragility fractures. In this study, we retrospectively evaluated 32 patients treated with primary retrograde TTC nail without subtalar or tibiotalar joint preparation for a mean of 2.4 years postoperatively. We specifically reviewed the charts for nail breakages at either joint, patients developing subtalar or tibiotalar joint pathology requiring additional treatment, including return to the operating room for formal joint preparation. Fracture union occurred in 100% of patients. There were 3 cases (10.0%) of hardware failure, and 2 of these cases were asymptomatic and did not require any treatment. One patient (3.3%) developed hardware failure with nail breakage at the subtalar joint. This patient developed progressive pain and symptoms requiring revision surgery with formal arthrodesis of the subtalar and tibiotalar joint. This study shows that retrograde hindfoot nailing without formal subtalar or tibiotalar joint preparation is an acceptable potential treatment option in ankle fragility fractures. Mid-term follow-up demonstrates favorable outcomes without the need for formal joint preparation in this high-risk population. Comparative studies with higher patient numbers and long-term follow-up are needed to confirm the results of this study.Levels of Evidence: Level IV.

CAN YOU PREDICT WHICH ‘ROUTINE’ CLOSED ANKLE FRACTURES REQUIRE EXTERNAL FIXATION RATHER THAN CAST IMMOBILIZATION? A RETROSPECTIVE MATCHED COHORT STUDY

IntroductionA subset of patients in cast awaiting fixation of ankle fractures require conversion to delayed external fixation (dEF). We aimed to evaluate the effect of delayed versus planned external fixation (pEF), then identify objective characteristics contributing to need for conversion.MethodWe extracted data from our booking system to identify all ankle external fixation procedures between 2010 to 2022. Exclusions included open fractures, the skeletally immature, and pilon or talus fractures. Fractures were classified using the AO/OTA classification, then a matched cohort was identified based on fracture classification. We compared the planned, delayed and matched cohorts for demographics, posterior malleolar fragment (PMF) ratio, and degree of displacement at presentation.ResultsWe identified 25 pEF, 42 dEF, and 67 matched patients. Ankles with dEF had a 3.8 day longer time to ORIF from presentation than those who had pEF, and had an infection rate of 9.5%, compared to 4% in the pEF group. Two patients in the dEF group required further operative intervention. There were no infections or reoperations required in the pEF or matched groups. The dEF group were more likely to have ≥2 reductions (OR 4.13), a PMF ratio of &gt;0.23 (OR 5.07), and have increased displacement at time of injury on lateral (32% vs 19%) and AP (62% vs 36%) radiographs.DiscussionOur retrospective study highlights the longer time to operation and increased infection rates of patients who do not get timely external fixation. We propose a series of objective parameters that predict failure of cast treatment and guide the surgeon to consider planned external fixation in some ankle

Metacarpal Fracture Fixation with Intramedullary Screws.

Background: Intramedullary screws (IMS) have become a viable option for metacarpal fracture fixation. To further appraise their utility, this study assessed clinical and patient-reported short- and medium-term outcomes of IMS fixation for extra-articular metacarpal fractures. Methods: A retrospective cohort study was performed in a series of 32 patients (with a total of 37 fractures) who underwent metacarpal fracture fixation over a 42-month period between January 2020 and July 2023. Results: Mean time for return to work was 39.8 days; mean time for return to full function was 88.4 days; total active motion was 250.7° (range: 204.9-270.9); Quick Disabilities of the Arm, Shoulder and Hand score was 2.3 (range: 0-22.7); mean visual analogue pain score was 0.9 out of 10 (range: 0-6) and a single complication was observed. Conclusions: The use of IMS in metacarpal fracture fixation is a practicable surgical option. IMS fixations yields a satisfactory duration for return to function, good postoperative range of movement, modest pain scores and low rates of complications. Level of Evidence: Level IV (Therapeutic).

Open Reduction and Internal Fixation of Mandibular Body and Parasymphyseal Fractures with Maxillomandibular Fixation and Broken Tooth Extraction

Open Reduction and Internal Fixation of Mandibular Body and Parasymphyseal Fractures with Maxillomandibular Fixation and Broken Tooth Extraction

The Safety of Volar to Dorsal Percutaneous Screw Fixation of Bennett Fracture-Dislocation - A Cadaveric Study.

Background: Bennett fractures are traditionally fixed with percutaneous K-wires from dorsal to volar, or with a volar to dorsal screw via a volar open approach. While volar to dorsal screw fixation is biomechanically advantageous, an open approach requires extensive soft tissue dissection, thus increasing morbidity. This study aims to investigate the practicality and safety of Bennett fracture fixation using a percutaneous, volar to dorsal screw, particularly with regard to the median nerve and its motor branch during wire and screw insertion. Methods: Fifteen fresh frozen forearm and hand specimens were obtained from the University of Auckland human cadaver laboratory. A guidewire is placed under image intensifier from volar to dorsal with the thumb held in traction, abduction and pronation. The wire is passed through the skin volarly under image intensifier, then the median nerve is dissected from the carpal tunnel and the motor branch of the median nerve (MBMN) is dissected from its origin to where it supplies the thenar musculature. The distance between the K-wire to the MBMN is measured. Results: In 14 of 15 specimens, the wire was superficial and radial to the carpal tunnel. The mean distance to the origin of the MBMN is 6.2 mm (95% CI 4.1-8.3) with the closest specimen 1 mm away. The mean closest distance the wire gets to any part of the MBMN is 3.7 mm (95% CI 1.6-5.8); in two specimens, the wire was through the MBMN. Conclusions: Wire placement, although done under image intensifier, is subject to significant variation in exiting location. While research has shown the thenar portal in arthroscopic thumb surgery is safe, our guidewire needs to exit further ulnar to capture the Bennett fracture fragment, placing the MBMN at risk. This cadaveric study has demonstrated the proposed technique is unsafe for use.