Bone Fixation Research Articles

Bioinspired design proposal for a new external bone fixator device

The article presents a new medical device through an authorial and interdisciplinary approach. It consists of a flexible external fixator, whose flexible property may bring advantages over rigid mechanisms. Its design was inspired by the DNA biological mechanism of condensation, while the modeling was based on the pseudo-rigid modeling technique. From the models obtained, this study conducted prototyping and computational tests to obtain a proof-of-concept of the bioinspired theory and dynamic functioning effectiveness. The prototyping relied on hot glue manufacturing and the computational simulations consisted of linear static analysis. The experimental analysis concluded that the prototype with fewer beams and thinner beams delivered better results in all three parameters: flexibility, height variation and rotation arc. In the computational analysis, among the design models with the variation of the number of beams, the model with 8 beams performed better. Concerning thickness variation, the one whose beams measured 8 mm in thickness showed better results. Among the models with length variation, the design made with 100 mm long beams better equilibrated the parameters.

All-Inside Anterior Cruciate Ligament Reconstruction: A Review of Advance and Trends.

Anterior cruciate ligament (ACL) injury is a common disease in orthopedics and mostly occurs as a noncontact injury in athletes. Patients' knee joint stability, which is crucial to their athletic ability, cannot be restored through conservative treatment; it can only be restored through ACLR (ACL reconstruction) surgery. The surgical techniques of ACLR are constantly evolving, from bone tendon bone (BTB) grafting combined with interface screw fixation to hamstring tendon autograft or allogeneic tendon and of suspension device constructs. In particular, the currently prevalent all-inside technique featuring good cosmetic results and quick recovery of early functions not only ensures the stable fixation of grafts but also reduces surgical trauma. This review compares the advantages and disadvantages of different aspects of all-inside ACLR, including graft selection and preparation, bone socket reconstruction, fixation methods, and surgical technique effects and limitations. It has been found that the all-inside technique excels both anatomically and clinically but still requires further development. Besides, it has some limitations, and high-quality randomized controlled trials are still required to compare the long-term effects of the all-inside technique and other ACLR techniques.

Electrochemotherapy Is Effective in the Treatment of Bone Metastases.

Bone metastases induce pain, risk of fracture, and neural compression, and reduced mobility and quality of life. Electrochemotherapy (ECT) is a minimally invasive local treatment based on a high-voltage electric pulse combined with an anticancer drug. Preclinical and clinical studies have supported the use of ECT in patients with metastatic bone disease, demonstrating that it does not damage the mineral structure of the bone and its regenerative capacity, and that is feasible and efficient for the treatment of bone metastases. Since 2009, 88 patients with bone metastasis have received ECT at the Rizzoli Institute. 2014 saw the start of a registry of patients with bone metastases treated with ECT, whose data are recorded in a shared database. We share the Rizzoli Institute experience of 38 patients treated with ECT for a bone metastasis, excluding patients not included in the registry (before 2014) and those treated with bone fixation. Mean follow-up was 2 months (1–52). Response to treatment using RECIST criteria was 29% objective responses, 59% stable disease, and 16% progressive disease. Using PERCIST, the response was 36% OR, 14% SD, and 50% PD with no significant differences between the two criteria. A significant decrease in pain and better quality of life was observed at FU.

A New Augmentation Method for Improved Screw Fixation in Fragile Bone.

Pertrochanteric fractures (TF) due to osteoporosis constitute nearly half of all proximal femur fractures. TFs are treated with a surgical approach and fracture fixation is achieved using metallic fixation devices. Poor quality cancellous bone in osteoporotic patients makes anchorage of a fixation device challenging, which can lead to failure of the fracture fixation. Methods to reinforce the bone-implant interface using bone cement (PMMA) and other calcium phosphate cements in TFs have been described earlier but a clear evidence on the advantage of using such biomaterials for augmentation is weak. Furthermore, there is no standardized technique for delivering these biomaterials at the bone-implant interface. In this study, we firstly describe a method to deliver a calcium sulphate/hydroxyapatite (CaS/HA) based biomaterial for the augmentation of a lag-screw commonly used for TF fixation. We then used an osteoporotic Sawbones model to study the consequence of CaS/HA augmentation on the immediate mechanical anchorage of the lag-screw to osteoporotic bone. Finally, as a proof-of-concept, the method of delivering the CaS/HA biomaterial at the bone-implant interface as well as spreading of the CaS/HA material at this interface was tested in patients undergoing treatment for TF as well as in donated femoral heads. The mechanical testing results indicated that the CaS/HA based biomaterial increased the peak extraction force of the lag-screw by 4 times compared with un-augmented lag-screws and the results were at par with PMMA. The X-ray images from the patient series showed that it was possible to inject the CaS/HA material at the bone-implant interface without applying additional pressure and the CaS/HA material spreading was observed at the interface of the lag-screw threads and the bone. Finally, the spreading of the CaS/HA material was also verified on donated femoral heads and micro-CT imaging indicated that the entire length of the lag-screw threads was covered with the CaS/HA biomaterial. In conclusion, we present a novel method for augmenting a lag-screw in TFs, which could potentially reduce the risk of fracture fixation failure and reoperation in fragile osteoporotic patients.

Current concepts in fracture healing: temporal dynamization and applications for additive manufacturing.

Objectives:Current surgical fracture treatment paradigms, which use rigid metallic constructs to heal bones, provide reasonable clinical outcomes; however, they do not leverage recent advances in our understanding of bone healing and mechanotransduction throughout bone healing. The objective of this review was to investigate the efficacy and potential clinical applicability of surgical techniques and implants that deliberately introduce interfragmentary motion throughout the healing process.Methods:The authors searched PubMed and Google Scholar databases for articles reporting on fracture repair using dynamic locking plates, dynamized surgical techniques, and reverse dynamization. Data collection also included assessment of additively manufactured (AM) implants that provide dynamic mechanical behaviors.Results:Forty articles were included for final review. It was found that accelerated rates of fracture healing can be achieved with staged 2-part surgeries or dynamic implant designs. Temporal dynamization, where static fixation of bones is followed by the introduction of micromotion and controlled loading, has been shown to improve callus volume and accelerate the healing response. Reverse dynamization, where micromotion is encouraged during early callus formation and arrested later, may represent a significant advance for the treatment of critical defect injuries. Advances in AM techniques will likely provide the ability to create high-resolution implants capable of dynamized and reverse dynamized modalities.Conclusions:There is no one-size-fits-all approach to optimization of fracture healing. However, it has been clearly demonstrated that fracture treatment can be enhanced by systematically altering the construct stiffness throughout the different phases of healing, which may be achieved with AM implant designs.

Irregular porous titanium enhances implant stability and bone ingrowth in an intra-articular ovine model.

Two commercially available porous coatings, Gription and Porocoat, were compared for the first time in a challenging intra-articular, weight-bearing, ovine model. Gription has evolved from Porocoat and has higher porosity, coefficient of friction, and microtextured topography, which are expected to enhance bone ingrowth. Cylindrical implants were press-fit into the weight-bearing regions of ovine femoral condyles and bone ingrowth and fixation strength evaluated 4, 8, and 16 weeks postoperatively. Biomechanical push-out tests were performed on lateral femoral condyles (LFCs) to evaluate the strength of the bone-implant interface. Bone ingrowth was assessed in medial femoral condyles (MFCs) as well as implants retrieved from LFCs following biomechanical testing using backscattered electron microscopy and histology. By 16 weeks, Gription-coated implants exhibited higher force (2455 ± 1362vs. 1002 ± 1466 N; p = 0.046) and stress (12.60 ± 6.99vs. 5.14 ± 7.53 MPa; p = 0.046) at failure, and trended towards higher stiffness (11,510 ± 7645vs. 5010 ± 8374 N/mm; p = 0.061) and modulus of elasticity (591 ± 392vs. 256 ± 431 MPa; p = 0.061). A strong, positive correlation was detected between bone ingrowth in LFC implants and failure force (r = 0.93, p < 10-13 ). By 16 weeks, bone ingrowth in Gription-coated implants in MFCs was 10.50 ± 6.31% compared to 5.88 ± 2.77% in Porocoat (p = 0.095). Observations of the bone-implant interface, made following push-out testing, showed more bony material consistently adhered to Gription compared to Porocoat at all three time points. Gription provided superior fixation strength and bone ingrowth by 16 weeks.

MCL Reconstruction Using a Flat Tendon Graft for Anteromedial and Posteromedial Instability

The main principles of the present medial collateral ligament (MCL) reconstruction techniques are (1) to approximate the natural anatomy and (2) to restore the main passive restraining structures in anteromedial and posteromedial knee instability. Therefore, we describe a technique using a flat tendon graft instead of tubular grafts with point-to-point bone fixation. Moreover, we address the deep MCL, a relevant restraint to anteromedial instability.

Trends in hospitalization for paediatric flatfoot: an Italian nationwide study from 2001 to 2016

BackgroundFlatfoot is a common condition in young patients, but usually resolves by adolescence. This study aimed to estimate annual trend hospitalizations for flatfoot in Italian paediatric population from 2001 to 2016.MethodsData of this study were collected from the National Hospital Discharge Reports (SDO) reported at the Italian Ministry of Health regarding the years of this paper (2001–2016). The yearly number of hospital admission for flatfoot, the percentage of males and females, the average age, the average days of hospitalization, primary diagnoses and primary procedures in the whole Italian population were calculated using descriptive statistical analyses.Results109,300 hospitalizations for flatfoot of young patients were performed during this period. 59.3% of patients were male and 40.7% female of the 10–14 years-old age class. The average days of hospitalization stay were 1.73 ± 1.27 days. The data highlights that the burden of flatfoot surgery is growing and affecting the healthcare system. The mean rate of hospital admissions in Italy for flatfoot in the young population was 82.14 for 100,000 inhabitants of the same age class.ConclusionsThe data highlights that the cases of flatfoot surgery increased from 2001 to 2016. The most common treatment was the “Internal Fixation Of Bone Without Fracture Reduction, Tarsals And Metatarsals followed by Subtalar Fusion and Arthroereisis. Further prospective studies on this topic may be conducted to improve the evidence of the results.

The first experience in the treatment of closed fractures of the metacarpal bones with the use of a short plaster cast

Method of conservative treatment of closed II-V metacarpal bone fractures was suggested. It included closed reposition of bone fragments and fixation by short plaster dressing. That dressing was a sugar-tongs plaster splint spreading from the palm to the back of the wrist via ulnar (radius) margin of hand. Careful modeling of plaster dressing with fulcrums on the palm and the back of the wrist provided stable fixation of bone fragments. That method of treatment was applied in 129 patients with closed fractures of II V metacarpal bones. Complete bone fragments reduction was obtained in 81 patients (62.8%)), significant improvement in 39 patients (30.2%). Secondary displacement of bone fragments in plaster dressing was noted in 8 cases (6.2%)). At 1.52 months follow up the results were excellent in 65% of patients, good results were achieved in 16.5%o of cases and satisfactory results in 18.5%). Unsatisfactory results were not observed.

Forearm Plate Fixation: Should Plates Be Removed?

Refracture after both bone forearm fracture fixation may vary with or without plate removal. We tested the null hypothesis that there is no difference in the rate of refracture in patients who have undergone open reduction and internal fixation of a diaphyseal forearm bone who have retained implants versus removed implants. We also studied factors associated with plate removal. We retrospectively identified 645 adult patients with a total of 925 primary fractures that underwent primary plate fixation of an ulnar or radial shaft fracture between 2002 and 2015 at a single institutional system. Patients with nonunion, pathological fracture or infection were excluded. Independent factors associated with refracture and plate removal were identified using multivariable analysis. Refractures occurred in 6.3% of the fractures that had forearm implant removal, compared to 2.1% of the fractures with retained plates. Refractures were independently associated with plate removal (OR: 3.7, 95% CI: 1.2-11.7, P=0.023) and was more frequent in the radius (OR: 2.4, 95% CI: 1.0-5.8, P=0.06). A refracture after implant removal occurred within 3 months after removal. Ulnar plates were removed more often compared to radial plates (OR: 2.6, 95% CI: 1.4-4.7, P=0.002) as were plates used for type A fractures compared to type C fractures (OR: 3.2, 95% CI: 1.1-9.2, P=0.032). The rate of refracture is higher after plate removal compared to patients who did not have plates removed. Although uncommon, refractures of the radius tend to be more common than a refracture of the ulna. If the implant is symptomatic on the ulnar side, it may be preferable to remove the ulnar implant and retain the radius implant rather than remove both plates when possible. Furthermore, limiting strenuous activity for three months after implant removal is a consideration.

Biomimetic 3D printed PCL/TCP/GelMA scaffolds with improved osteogenesis and angiogenesis for non-load bearing applications

The strategy of biomimicry is crucial to effectively improve osteogenesis and angiogenesis for bone tissue engineering scaffolds, however, this approach remains challenging. In this study, we used a composite including PCL, TCP, and GelMA to mimic the heterogeneous bone composition. Meanwhile, hierarchical pores were successfully created through 3D printing, surface modification, and GelMA infiltration. Results showed that our 3D printing platform presented a high level of microstructural control of scaffolds and produced scaffolds with a porosity of 68.48±0.82%, an open porosity percentage of 97.81±1.44%, and a compressive strength of 2.68±0.03 MPa. In addition, triangular pores of 495.03±3.67 μm, ECM-like pores of 126±31 μm, and surface modified micro/nano roughness were observed from our 3D printed composite scaffolds leading to significantly improved hydrophilicity. Finally, in vivo results demonstrated that our 3D printed composite scaffolds exhibited enhanced osteogenesis and expedited transition from vascular formation and ECM deposition to mineralized bone formation, which was promising for clinical translations towards non-load bearing bone fixations.

Image guided procedures to stabilize the pelvic girdle in cancer patients

With the advancement of oncologic treatments, advanced cancer patients with bone involvement survive longer. Cancer involving weight-bearing bones of pelvic girdle results in mechanical pain that interferes with ambulation, deteriorates quality of life, and causes serious complications that may accelerate their demise. Among common treatments for bone metastases, radiation therapy does not reinforce bone and surgical fixation is often complex with high risks of complications and may not be possible due to comorbidities in this patient population. Image guided percutaneous stabilization techniques have been proven as viable options in this setting.

New way to obtain the poly(L-lactide-co-D,L-lactide) blend filled with nanohydroxyapatite as biomaterial for 3D-printed bone-reconstruction implants

A novel, bone-reconstruction dedicated polymeric-nanohydroxyapatite material has been prepared for 3D-printed implant. The composites of poly(L-lactide-co-D,L-lactide) (PLDLLA) and nanosized hydroxyapatite were prepared by a co-rotating twin-screw extrusion. Structural properties of the filler and polymeric blends were characterized by XRD (X-ray Powder Diffraction), SEM (Scanning Electron Microscopy), and EDS mapping (energy dispersive spectroscopy), FT-IR (Fourier-transformed infrared spectroscopy), and NMR (Nuclear Magnetic Resonance) technics. Molar masses of the composites at various preparation steps were also investigated. The structural studies and thermogravimetric analysis proved a successful preparation of the nanohydroxyapatite and its nanocomposites. Mechanical results in conjunction with density values, reported as close to human bone, evidenced usability of this novel material for internal bone fixation implant. Contact angle analysis showed favored growth of tissue on the biocomposite containing 10 wt% of the filler. The PLDLLA-based composite can be an excellent candidate for bone reconstruction implants due to their superior mechanical properties, bioactivity, and complete resorbability.

Mathematical modeling of the osteosynthesis of the lower leg bones using a titanium mesh for their congenital pseudoarthrosis in the lower third

Background. Congenital pseudarthrosis of the lower leg bones belongs to the group of orphan diseases and manifests itself in non-union (pseudarthrosis) of the lower leg bones, which leads to the formation of deformity and shortening of the limb, and, as a result, is accompanied by a persistent violation of the limb’s supportability. To date, the question of choosing a surgical technique and optimal fixation in the surgical treatment of congenital pseudarthrosis of the lower leg bones remains unresolved. The purpose was to investigate the stress-strain state of the shin model with pseudarthrosis of its bones in the lower third during their osteosynthesis using a titanium mesh. Materials and methods. Osteosynthesis was simulated with an intramedullary nail, wires, and a block of bone grafts on both shin bones with the imposition of a titanium mesh over the grafts under the influence of two types of compression and torsion loads. Results. Studies have shown that additional fixation of the bone graft block with a titanium mesh allows reducing the stress level at almost all control points of the model of osteosynthesis of the lower leg bones in their congenital pseudarthrosis, both under compression and torsion. As the most positive changes, we can note a decrease in the stress values on the tibia around the nonunion line. This can be explained by the fact that the bone graft block reinforced with a titanium mesh takes on a great load. The same fact contributes to the increase in the level of stress at the lower border of the graft block and tibia. The negative factors include an increase in the level of stress along the line of non-union of the fibula. This is also explained by an increase in the modulus of elasticity of the bone graft block, which further loads the fibula. Conclusions. The use of a titanium mesh for additional fixation of the shin bones in the treatment of their congenital pseudarthrosis has a positive effect on the stress-strain state of the model, which is confirmed by a decrease in the stress level at almost all control points of the model, both under compression and torsion loads. The most positive changes are observed along the line of non-union of the tibia.

Optimal blocking screw placement for retrograde IM nail fixation of distal femur fracture: a standardized biomechanical study of "osteoporotic" synthetic bone.

Intramedullary (IM) nail use for metaphyseal fracture management is problematic in long bones like the femur because the larger medullary cavity allows increased fracture motion and potentially increased implant failure and malunion/nonunion risk; Achieving effective distal femur fracture fixation is even more difficult in osteoporotic bone. Blocking screws to control IM nail movement are known to be effective for tibia fracture management. Few studies have evaluated IM nail and blocking screw use efficacy for distal femur fracture fixation in osteoporotic bone. This study used an osteoporosis simulation synthetic bone model to evaluate retrograde IM nail fixation of a standardized non-comminuted, extra-articular distal femur fracture with and without blocking screws. The hypothesis was that use of one or two blocking screws would increase IM nail fixation stability as evidenced by greater peak IM nail load and lesser movement. A servohydraulic device under displacement control collected loading force versus movement deflection data. Shapiro-Wilk tests confirmed data normality. One-way analysis of variance and Tukey post hoc tests were used to compare condition specific loading force and movement differences. In the coronal plane, blocking screw conditions displayed greater loading ranges (38.3 ± 2 vs. 19.1 ± 2N, 100.5% difference) (p < 0.0001) and lesser movement (2.0 ± 0.3 vs. 6.86 ± 0.4mm, 243% difference) (p < 0.0001). In the sagittal plane, the two blocking screw condition displayed a significantly greater loading magnitude (29.9 ± 6 vs. 20.8 ± 2.3N, 43.8% difference) than the identical control condition without blocking screws (p = 0.018); however, movements were comparable (p = 0.82). Long-axis rotational loading failed to reveal load magnitude differences (p = 0.28); however, two different blocking screw conditions displayed decreased movement (1.32 ± 0.2 vs. 2.05 ± 0.3mm, 53.8% difference) compared to other conditions (p ≤ 0.018). Use of one or two blocking screws on the medial and lateral sides of the IM nail decreased coronal plane movement in the intramedullary canal. Combining retrograde IM nail implantation with blocking screws reduced medial-lateral IM nail movement and increased fracture stability. These characteristics may help prevent fixation failure, malunion, and even nonunion in patients with a distal femur fracture in osteoporotic bone.

Randomized Controlled trial Comparing Single Bone and Both Bone Fixation for Forearm Fracture in Children

Background: Fractures of shaft of the radius and ulna are one of the commonest injuries seen in the paediatric age group. Single bone intramedullary fixation has been advocated in the treatment of unstable diaphyseal forearm fractures. We conducted this study to evaluate the radiological and functional outcome in single bone and both bone fixation in forearm fracture in children. Methods: We designed a prospective randomized trial to compare single bone and both bone fixations in forearm fracture in aged 8-15 years. Fifty patients were presented to our institution during the period from May 2016 to May 2017 and randomly assigned a group with 25 patients in each group. Patients in Group A (SBF) were fixed with intramedullary Rush pin in ulna and those in Group B (DBF) were both radius and ulna were fixed. The patients were followed up for a period of twelve weeks. A radiological and functional outcome was evaluated and was compared and graded using Price et al. (1) criteria. Results: Among the 50 patients analyzed, randomization was successful. ROM of elbow at the final follow up was not statistically significant differences between two Groups. There were no statistically significant differences of radiological parameters at the final follow-up. Final assessment with Price et al. (1) criteria showed no statistically significant differences between two groups (P value- 0.1). Conclusion: Single bone ulna intramedullary fixation was comparable in terms of function and radiological parameter for both-bone forearm diaphyseal fracture in children.

DOES ULNA FIXATION ALTER THE OUTCOME FOR DISTAL-THIRD FOREARM FRACTURES IN CHILDREN?

ABSTRACTIntroduction Fractures of the distal third of the forearm are common in the pediatric population. Conservative treatment of an ipsilateral fracture of the distal ulna metaphysis is one of the risk factors for loss of reduction. Percutaneous fixation of the fracture with K-wires is recommended. This study aims to evaluate the outcome of percutaneous fixation of both bones performed as the primary treatment.Materials and Methods A randomized, open, prospective, clinical trial was conducted, including skeletally immature patients who underwent surgery for fractures of the distal radius and ulna. They were randomized into two groups, one with fixation only of the radius fracture and the other with fixation of both the radius and the ulna fractures, and they were followed clinically and radiologically for up to 12 weeks postoperatively.Results Sixteen children were selected. In the intraoperative period, fluoroscopy was activated for a longer time when fixing the ulna (p = 0.011) and the surgical time was longer in this group (p = 0.014). In the postoperative evaluations, the group whose surgery involved the fixation of both bones had a lower postoperative pain score (p <0.001) and less time away from school (p <0.001).Conclusions In this study, postoperative pain and absence from school were both less when fixation of the radius and ulna was performed. Evidence Level II; Randomized Controlled Study.

Acute Fingertip Injuries in Sudanese Patients: Patterns and Clinical Presentation

Background: Acute fingertip injuries are common and may lead to functional and aesthetic complications if not treated properly. Different types of trauma result in injuries with variable severity and affect certain risk groups. Objectives: To study the high-risk groups affected by fingertip injuries, their etiological factors, clinical features, and wound patterns, and the influence of hand dominance. Study Design: A descriptive study of 103 consecutive patients with 144 acutely injured fingertips. Data Collection/Analysis: We obtained demographic data, occupation, hand dominance, time and cause of trauma, and the presenting symptoms. Further, clinical examination, radiological, and laboratory studies were performed. Wound characteristics were classified according to the pulp, nailbed and bone (PNB) classification. The data were analyzed with the Fisher’s exact test and Chi-square test. Results: A total of 103 patients (88 males, 15 females) presented with 144 injured fingertips. The male to female ratio was 5.8:1, and the mean age was 27.5 years. The age group affected most commonly was 16 - 20 years. There was a strong association between hand dominance and fingertip injuries, as in 65% of the cases, the dominant hand was injured more frequently than the non-dominant (p = 0.01). The sharp and blunt injuries observed involved the left hand more than the right and were often the result of machinery-related trauma (p = 0.04). Approximately 68% of the injuries were related to work, while 26% were attributable to domestic accidents. In 22% of the cases, seasonal workers were the category affected most often, followed by factory workers. Nearly half of the injuries were related to working with machines, while door-trapping was the most frequent cause of injury in children under 5. The index finger was injured most frequently (31.9%), followed by the middle finger (27.9%), while the thumb and little fingers were involved least (11% for each). Pulp injuries were seen in 97% of cases, commonly with lacerations (39.6%, n = 139) while complete pulp loss was seen in 12.6% of cases. 87% of the cases were nail bed injuries, often with nail bed lacerations (28.6%, n = 126), while complete nail bed loss was observed in 9.5% of cases. Tuft fractures were the commonest bone injuries (26%), while complete bone loss was seen in 7.7% of the injured bones (n = 104). Conservative management was carried out on 9% of fingers, while the others required various methods of surgical repair. Nail bed repair was performed in 48.8% of cases (n = 126), while bone fixation was required in 20.2% (n = 104). Conclusions: Fingertip injuries are highly common in practice. In our study, the age, gender, mechanism of trauma and hand dominance had their influence on the pattern of injury. Finally, wound characteristics determine the type of management required.

Acute Fingertip Injuries in Sudanese Patients: Patterns and Clinical Presentation

Background: Acute fingertip injuries are common and may lead to functional and aesthetic complications if not treated properly. Different types of trauma result in injuries with variable severity and affect certain risk groups. Objectives: To study the high-risk groups affected by fingertip injuries, their etiological factors, clinical features, and wound patterns, and the influence of hand dominance. Study Design: A descriptive study of 103 consecutive patients with 144 acutely injured fingertips. Data Collection/Analysis: We obtained demographic data, occupation, hand dominance, time and cause of trauma, and the presenting symptoms. Further, clinical examination, radiological, and laboratory studies were performed. Wound characteristics were classified according to the pulp, nailbed and bone (PNB) classification. The data were analyzed with the Fisher’s exact test and Chi-square test. Results: A total of 103 patients (88 males, 15 females) presented with 144 injured fingertips. The male to female ratio was 5.8:1, and the mean age was 27.5 years. The age group affected most commonly was 16 - 20 years. There was a strong association between hand dominance and fingertip injuries, as in 65% of the cases, the dominant hand was injured more frequently than the non-dominant (p = 0.01). The sharp and blunt injuries observed involved the left hand more than the right and were often the result of machinery-related trauma (p = 0.04). Approximately 68% of the injuries were related to work, while 26% were attributable to domestic accidents. In 22% of the cases, seasonal workers were the category affected most often, followed by factory workers. Nearly half of the injuries were related to working with machines, while door-trapping was the most frequent cause of injury in children under 5. The index finger was injured most frequently (31.9%), followed by the middle finger (27.9%), while the thumb and little fingers were involved least (11% for each). Pulp injuries were seen in 97% of cases, commonly with lacerations (39.6%, n = 139) while complete pulp loss was seen in 12.6% of cases. 87% of the cases were nail bed injuries, often with nail bed lacerations (28.6%, n = 126), while complete nail bed loss was observed in 9.5% of cases. Tuft fractures were the commonest bone injuries (26%), while complete bone loss was seen in 7.7% of the injured bones (n = 104). Conservative management was carried out on 9% of fingers, while the others required various methods of surgical repair. Nail bed repair was performed in 48.8% of cases (n = 126), while bone fixation was required in 20.2% (n = 104). Conclusions: Fingertip injuries are highly common in practice. In our study, the age, gender, mechanism of trauma and hand dominance had their influence on the pattern of injury. Finally, wound characteristics determine the type of management required.

Effect of Extrusion Ratio on Mechanical Properties of TCP/PLA Bone Fixation Screw Molded by Extrusion Die Forging

Metal bone fixation devices are used in the treatment of bone fractures. However, metallic materials cause inflammation in the body. In this study, we focused on bioabsorbable composite material of poly(lactic acid) (PLA) and tricalcium phosphate (TCP). However, the mechanical properties of TCP/PLA composites are lower than those of metal materials. In order to improve the mechanical properties of TCP/PLA bone fixation screws, molecular orientation by extrusion die forging was focused under various extrusion ratios (ER) and TCP contents. The orientation of molecular chains depends on the forging conditions. The purpus of this study is investigation effect of forging condition on mechanical properties of TCP/PLA scres. Then, screws were formed by extrusion die forging at ER 1.3, 4 and 8, and shear strengthe of the screws was measured. As a result, the shear strength increased with ER, and the maximum shear strength was observed at ER 4.