Pin Fixation Research Articles

Analyzing Linear and Angular Deviations After Guided Surgery for Dental Implant Placement: A Preliminary Study.

To assess the accuracy and precision of prosthetically driven implant placement achieved through static computer-aided implant surgery by analyzing the linear and angular deviations of implants. A total of 53 implants were included in the study. The implants were positioned using either tooth-supported templates or tooth-and-tissue-supported templates with fixation pins. Two distinct guided surgery approaches were used: pilot drill guided and fully guided. 3D data from the implant planning phase was superimposed with the 3D data from the final implant positions using the 'Treatment Evaluation' tool within coDiagnostiX implant planning software (Straumann). This enabled the automatic calculation of deviations in implant placement accuracy. The average angular deviation observed was 3.90 degrees. For linear deviations, the mean 3D deviation was 1.04 mm at the most coronal point of the implants and 1.56 mm at the implant apex. This research demonstrates the feasibility of a digital workflow for guided implant surgery, offering a promising treatment option. Nonetheless, it is important to note that deviations do occur, particularly in the apical region of the implant. Care should be taken, particularly in cases of limited bone availability.

Simple Talectomy is a Beneficial Surgical Procedure for Talipes Equinovarus and Other Severe Neuromuscular Foot Deformities

Noninvasive techniques are gold standard to redress Severe Neuromuscular Foot Deformity (SNFD). However, simple talectomy may be considered to obtain a stable, plantigrade, pain-free foot. We present a 10-year follow-up accessing radiological correction rates, functional outcomes, complications, and patient satisfaction. This retrospective case series evaluated talectomies in 2012 to 2022. Simple talectomy was combined with Steinman pin fixation of calcaneus to tibia for approximately 6 weeks. Diagnoses primarily included arthrogryposis multiplex congenita and cerebral palsy. Indications were pain, wounds/pressure marks, severe rigidity, and residual/recurrent deformity. The primary outcome was radiological correction. Tibiotalar angle (TiTa) and tibiocalcaneal angle (TiCa) were measured on mediolateral projections. Secondary outcomes were functional scores of pain/deformity graded as good, fair or poor. Furthermore, validated patient-reported outcome measures, that is, EQ-5D-5L and the Scoliosis Research Society-30 Questionnaire (2 items) assessed health-related quality of life and patient satisfaction. Nineteen talectomies in 11 patients were analyzed. Mean follow-up was 62 months (range 9-112 months). Mean TiTa was 137° (95%CI 128;146). TiCa improved significantly: Mean difference -24° (95%CI -44;-5, p = .02). All feet became plantigrade and pain-free with no skin issues. Functional outcomes were graded as 9/19 good, 10/19 fair and 0/19 poor. Parents/primary caregivers were mainly satisfied. Perceived health was 54 (95%CI 34;75) out of 100 on a visual analogue scale, emphasizing complex medical conditions. In conclusion, simple talectomy is a suitable salvage procedure for SNFD.

The Scalloped Surgical Guide as an Alternative to Flat Bone Reduction Guide in Full-arch Implant Restoration.

The goal of this clinical report was to present an alternative to traditional flat bone reduction guides, using a custom-designed 3D printed guide according to the future gingival margin of the planned dentition. A 61-year-old female with concerns regarding her smile appearance was presented. The initial examination revealed excessive gingival show accompanied by excessive overjet. The dentition was in a failing situation. The proposed treatment plan, relying on the sufficient amount of bone and keratinized tissue, consisted of re-contouring of the alveolar ridge and gingiva and placement of six implants and a FP-1 prosthesis after extraction of all remaining maxillary teeth. Digital smile design was completed, and a fully-digitally-guided surgery was planned. This consisted of utilizing three surgical guides. Starting with the fixation pin guide and continuing with the scalloped hard and soft tissue reduction guide and finally, the implant placement template. Following the surgery, the patient received a temporary restoration and on the 4-month follow-up, a new poly-methyl meta-acrylate temporary prosthesis was delivered. The patient's 7-month follow-up is presented in the paper. The report of this triple-template guided surgery indicated that digital 3D planning is a considerably predictable tool to properly establish and evaluate future occlusal plane, smile line, and lip support. Scalloped guides seem to be an excellent alternative to conventional bone reduction guides since they require less bone removal and improve patient comfort during surgery.

Distal humeral osteotomy for cubitus varus in children compared to adolescents

BackgroundWhile pediatric cubitus varus has often been considered merely a cosmetic deformity, long-standing cubitus varus can lead to symptomatic pain and elbow instability in adults and may present as early as adolescence. The purpose of this study was to compare patient and radiographic characteristics, surgical factors, and symptom resolution after distal humeral osteotomy for cubitus varus in pediatric versus adolescent patients. MethodsThis is a retrospective single-institution review of 17 patients (12 patients <10.0 years (group Peds); 5 patients >10.0 years (group Adol)) were treated for cubitus varus with distal humeral osteotomy from 2003 to 2019. Peds had a median age of 6.3 years (range, 2.7-7.8 years) at the time of osteotomy, and Adol had a median age of 14.1 years (range, 13.5-16.7 years). A Fisher’s exact test was used to compare categorical variables between Peds and Adol, and continuous variables were compared using Mann-Whitney or Student’s t-test depending on normality results using the Shapiro-Wilk test. Statistical significance was set at P<.05. ResultsPreoperative pain was present in 17% (2/12) of Pediatric patients (Peds) but 100% (5/5) of Adolescent patients (Adols). Mechanical symptoms were present in 17% (2/12) of Peds and 80% (4/5) in Adol. Radiographic correction and final range of motion did not significantly differ between the 2 groups. The mean tourniquet time was 83 minutes in Peds and 117 minutes in Adol. Pin fixation was used in 100% (12/12) of Peds; 80% (4/5) of Adol had plates. At the final follow-up, all Peds had resolution of symptoms, but 60% (3/5) Adol had continued pain and mechanical symptoms. ConclusionsAlthough both pediatric and adolescent patients have similar radiographic correction and range of motion after distal humeral osteotomy to correct cubitus varus, the surgery may be more technically difficult in adolescent patients, with longer tourniquet times and the use of plate instead of pin fixation. Adolescents should be counseled that, like adults, their symptoms may not completely resolve after correction of radiographic and clinical deformity. The authors recommend that cubitus varus be corrected in childhood prior to the development of symptoms in adolescence. Key Concepts1)Cubitus varus following pediatric distal humerus fracture may present with pain and mechanical symptoms as early as adolescence.2)Although pediatric and adolescent patients may have similar radiographic correction and range of motion after distal humeral osteotomy, the surgery is technically more difficult in adolescent patients.3)Adolescents should be counseled that pre-operative symptoms may not completely resolve after correction of radiographic and clinical limb deformity.4)It is the authors’ opinion that cubitus varus should be surgically corrected before a child reaches adolescence, when it is technically less demanding and before mechanical symptoms and pain develop. Level of EvidenceLevel III – Retrospective Cohort Study

Three-in-one protocol for the management of hemodynamically unstable paediatric pelvic fracture – a level one trauma centre 15 year review

A three-in-one protocol comprised of pelvic external fixation, retroperitoneal pelvic packing, and angiography with or without embolization has been developed and used in our centre to improve survival outcomes of hemodynamically unstable pelvic fractures since 2008. Fourteen paediatric patients over a period of 15 years are reviewed in this case series. The mean age is 11.6 and standard deviation is 4.6. The mean injury severity score is 31.6. Sixty four percent underwent three-in-one protocol management. The overall survival rate at index hospital admission and at one year is 85.7% which is higher than the adult group (81%) from a study conducted at our centre and comparable to the rate in paediatric group. One patient had pelvic external fixator pin tract infection and two had lower limb ischemia post embolization. At 6 months follow up, one patient had pelvic pain and one had hip protrusio. We conclude that improvement in survival outcome also applies to the paediatric population. Technical differences in the paediatric group is highlighted to minimize potential complications.

Result of the pin fixation with mini-open technique for irreducible distal radius diaphyseal metaphyseal junction fractures in child

Aim: Although conservative treatment remains the preferred choice for distal radius fracture in children, reduction losses and failure to achieve reduction remain the main problems at diaphyseal metaphyseal junctional fractures. There is no consensus on the surgical treatment of displaced metaphyseal-diaphyseal distal radius fractures. This study aims to evaluate the result of the crossed pin fixation applied with the mini-open technique at pediatric metaphyseal-diaphyseal distal radius fractures. &#x0D; &#x0D; Methods: The radiological and clinical outcomes of pediatric distal metaphyseal diaphyseal distal radius fractures operated between 2018 and 2020 were retrospectively investigated. The clinical follow-ups of the patients were performed in the second, fourth, sixth weeks and the third month. Radiological recovery time, reduction losses during follow-up, complications, and forearm and wrist range of motion were examined. &#x0D; &#x0D; Result: There were 13 boys and 6 girls with an average age of 10.1 (8-12 years). Radiographs taken immediately after the operation showed less than 5% translation in the coronal plane and less than 10% translation in the sagittal plane. An average of 4 degrees of change was observed in the lateral radiographs, and an average of 3 changes was detected in the anterior to posterior (AP) radiographs at the last follow-up. No limitation in the range of motion was observed in the patients. &#x0D; &#x0D; Conclusion: Our data showed that the pin fixation with the mini-open technique was a suitable method to treat metaphyseal-diaphyseal distal radius fractures with a satisfactory alignment and achieving stable fixation.

Pull-out resistance of connected K-wires for osteosynthesis: development of a numerical model

A predictive finite element model was developed to investigate the best configuration of a fixation pins system consisting of two K-wires inserted in a synthetic model (Sawbones®) at different angles and secured to a connecting rod. Two key parameters were considered to determine the best configuration delivering the higher pull-out strength and lower pull-out length: the diameter and insertion angle. Results show that as the diameter and insertion angle increased, the pull-out force increased, while the pull-out length decreased. Results are successfully compared with available experimental data in literature. This model can be used as an alternative to experimental study.

The Current Concept and Evidence-Based Practice in the Base of the First Metacarpal Bone Fracture.

Repetitive instances of sudden injuries to the first metacarpal bone can affect thumb movement. These injuries typically occur after vertical impact to the thumb. The treatment for these injuries should focus on restoring the structure and biomechanics of the trapeziometacarpal joint, with surgery being recommended for optimal results. Bennett's fracture involves the bifurcation of the bone into two distinct fragments, characterized by a smaller fragment and a larger counterpart. Rolando fracture is associated with a fracture of the base of the first metacarpal bone, typically divided into three parts. An extra-articular fracture involves the metacarpal bone of the thumb. Conservative treatment outcomes have been found to be unsatisfactory when the fracture is displaced. Therefore, surgery methods such as minimally invasive surgery, open reduction, and arthroscopic surgery have been proven to be effective. Surgical techniques for bone procedures include pin fixation, direct screw fixation, indirect screw fixation, and mini-plate fixation. Additionally, the prognosis of this condition depends on the ability to restore joint mobility during rehabilitation.

Cadaveric biomechanical assessment of different configurations for a novel pin and plate fixation method in distal humerus fractures

Use of dual pre-contoured plates has been accepted as the treatment of choice in distal humerus fractures despite challenges especially in very distal or highly fragmented fractures. Aiming to improve results in such instances, our newly proposed method uses several K-wires fixated by a small reconstruction plate. Drawing on the results of previous finite element studies, the current study aims to compare the stiffness of three clinically common variations of this method using biomechanical testing in cadaveric humeri. 24 samples were divided into three groups and fractures were simulated. Groups I and II used 1.5 mm K-wires in differing configurations while 2 mm wires were used in group III. All samples underwent compression, anterior and posterior bending, and torsional testing as well as failure testing. Our results indicated that Group III had significantly higher stiffness in flexion, extension, and torsion (p < 0.05). In failure, group III had the highest mean stiffness in anterior bending and torsion (861.2 N, 30.9 Nm). Based on previous and current results, this new Persian fixation method, especially when implemented using 2 mm K-wires, shows promise in achieving suitable stability and may be useful as an alternative approach in complex distal humerus fractures.

GLUEING OSTEOCHONDRAL FRAGMENTS: DEVELOPMENT OF A NOVEL DUAL ADHESIVE PRECLINICAL MODEL STRATEGY

The fixation of articular fractures, with many small osteochondral fragments, is a challenging unmet need where a bone adhesive would be a useful adjunct to standard treatments. Whilst there are no such adhesives in current clinical use, preclinical animal models have demonstrated good healing of bone in unloaded models using an adhesive based on phosphoserine modified calcium phosphate cement (PM-CPC). An ex-vivo human bone core model has shown that this adhesive bonds freshly harvested human bone. To confirm this adhesive is capable of supporting loaded osteochondral fragments a porcine model has been developed initially ex-vivo on the path to an in-vivo study. In this model bone cores, harvested from the medial knee condyle, are glued in place with the adhesive. In-vivo adjacent pairs of bone cores would be replaced with adhesive and a control with conventional pin fixation respectively. As osteochondral bone fragments have both bone and cartilage components, this suggested a dual adhesive strategy in which components designed for each tissue type are used. This concept has been explored in an ex-vivo porcine pilot study presented herewith. At the subchondral bone level, the PM-CPC was used. At the cartilage level, a second adhesive, a methacrylated phosphoserine containing hyaluronic acid (MePHa) hydrogel designed specifically for soft tissues was applied. This is a challenging model as both adhesives have to be used simultaneously in a wet field. The pilot showed that once the subchondral component is glued in place, the PM-CPC adhesive intruding into the cartilage gap can be removed before applying the cartilage adhesive. This enabled the MePHa adhesive to be injected between the cut cartilage edges and subsequently light-cured. This two-stage gluing method is demanding and an in-vivo pilot is necessary to perfect and prove the operative technique.Acknowledgements: The human bone core project was partially financed by Innovation Fund of Västra Götaland Region, Sweden. The MePHa hydrogel work was supported by a Swiss National Fund grant # CR23I3_159301.

Effect of Membrane Fixation and the Graft Combinations on Horizontal Bone Regeneration: Radiographic and Histologic Outcomes in a Canine Model.

The aim of this study was to determine the effect of membrane fixation and combinations of bone substitute materials and barrier membranes on horizontal bone regeneration in peri-implant defects. Eight mongrel dogs underwent chronic buccal peri-implant dehiscence defects creation and were randomized into 4 groups: (a) deproteinized bovine bone mineral 1 (DBBM1) with a native collagen membrane (CM) (BB group, positive control group), (b) DBBM1 with native CM and 2 fixation pins (BBP group), (c) DBBM2 with a cross-linked CM (XC group), and (d) DBBM2 with cross-linked CM and 2 fixation pins (XCP group). Following 16 weeks of healing, tissues were radiographically and histomorphometrically analyzed. The total augmented area was significantly larger in the BBP, XC, and XCP groups compared to the BB group (4.27 ± 3.21, 7.17 ± 7.23, and 6.91 ± 5.45 mm2 versus 1.35 ± 1.28 mm2, respectively; P = 0.022). No significant difference for the augmented tissue thickness was observed among the 4 groups. The augmented tissue thickness measured at 3 mm below the implant shoulder was higher in BBP, XC, and XCP than that in BB (2.43 ± 1.53, 2.62 ± 1.80, and 3.18 ± 1.96 mm versus 0.80 ± 0.90 mm, respectively), trending toward significance (P = 0.052). DBBM2 and a cross-linked CM were significantly more favorable for horizontal bone regeneration compared to DBBM1 and a native CM. However, when DBBM1 and a native CM were secured with fixation pins, outcomes were similar. The addition of pins did not lead to more favorable outcomes when a cross-linked CM was used.

Functional outcome of close reduction and internal fixation by C-C screw or Steinmann pin fixation of fracture calcaneum

Abstract Background: Fracture of calcaneum results in serious and prolonging disability. Considering the high rate of malunion and severe loss of function, it will be better to choose open reduction and internal fixation as a primary mode of treatment for calcaneum fractures. Materials and Methods: This study consists of 45 fractures of calcaneum treated by using close reduction and internal fixation and subtalar arthrodesis. Of the 45 fractures, 16 (35.56%) were treated by using the C-C screw within 2 weeks of injury and 29 (64.44%) were treated by using the percutaneous k-wire or Steinmann pin or C-C screw. Results: At the final follow-up, the mean AO foot and ankle score score of the patients was 89.28 with P value ≤ 0.0001. Conclusion: Early motion prevents stiffness of subtalar joint and ankle joint and leads to early function and psychological rehabilitation. Close reduction and internal fixation by using the C-C screw or Steinmann pin is a safe and effective method for treating displaced intra-articular fracture of calcaneum.

Early Clinical Efficacy of Small Incision Reduction and Superior Closed Pin Fixation of Goss-Ideberg Type III Glenoid Fractures using X-ray and CT Scan.

Imaging techniques such as X-rays and 3D Computed Tomography (CT) are used to diagnose and evaluate a patient's shoulder before and after surgery. Identifying the kind, location, and severity of a shoulder fracture helps surgeons choose the right treatment and surgery. The study examines the effectiveness of small incision reduction and superior closure pinning in treating Ideberg type III glenoid fractures identified by X-ray and CT scans. From October 2017 to June 2022, 40 patients with Ideberg type III glenoid fractures underwent mini-incision reduction and superior closed pinning fixation using the Anterior (AA) and Posterior (PA) approaches. Pre- and post-surgery shoulder scores and imaging data were analyzed. Outpatient review and shoulder anteroposterior radiographs were collected at 1, 3, 6, and 12 months after surgery. We assessed shoulder joint function using the American Shoulder and Elbow Society (ASES) shoulder score, VAS score, Constant-Murley Shoulder Outcome (Constant) score, and DASH score. A total of 40 patients were monitored for 14-16 months, averaging 15.2 ± 0.3 months. All fractures were healed between 14-25 weeks from X-rays, averaging 17.6 ± 5.4 weeks. Both the AA and PA groups had similar shoulder score changes. However, the AA group did better. In all cases, ASES shoulder scores were outstanding at 80%. Radiographs demonstratedno traumatic arthritis or internal fixation failure consequences like screw loosening or breakage. It was concluded that Ideberg type III glenoid fracture reduction with an anterior small incision and superior closed pinning hollow lag screw internal fixation could be successful.

The "HAT-TRICK" technique: A modification of soft tissue grafting using volume stable collagen matrix and cross-linked hyaluronic acid. Part A: The pontic site

Vertical soft tissue augmentation between implants can be clinically challenging and burdensome for patients when employing conventional techniques. Recently, with the introduction of xenogenic collagen matrices, the principle of single-site surgery has become more common. However, some issues persist regarding graft stability and tissue integration. In the present technical note, the authors introduce the “HAT-TRICK” technique to address these observed difficulties. As the name suggests, this technique is believed to provide improved stability, volumetric gain, and histological integration of the implanted matrix by shaping it appropriately resembling a hat over the crest with apical bevels, stabilized with fixation pins and infused with cross-linked hyaluronic acid (xHya). A two-month observation of a bi-maxillary case is presented with detailed description of the technique and digitalized comparison methods for an easier explanation of the introduced technique.

Comparison of antegrade and retrograde cross pin fixation in the surgical treatment of pediatric supracondylar femur fractures: A biomechanical study

PurposeThe aim of this study is to compare biomechanical stability of Kirschner wires (K-wires) sent with antegrade and retrograde technique in the fixation of pediatric supracondylar femur fractures. Materials and MethodsA transverse fracture model was created two centimeters above the physis in 24 synthetic bone models suitable for the pediatric femur bone structure. The models were randomly divided into two groups as 12 bones each. In the first group (Group 1), 12 bone fracture models were retrogradely fixed with two cross K-wires. In the second group (Group 2), the fracture was fixed antegradely. In Group 2, both wire ends were allowed to protrude three millimeters from the femoral condyles. The stability of the groups was tested biomechanically by exposing them to varus and extension forces. The forces corresponding to 1 mm, 2 mm, 3 mm and 4 mm displacement and failure loads were calculated in two groups. ResultsAccording to the test results regarding displacements and failure loads, the retrograde group was found to be significantly stronger than the antegrade group against varus loads (p < 0.05). When the groups were compared in terms of extension strength, the results of the two groups were similar and there was no statistical difference between them (p > 0.05). ConclusionRetrograde cross K-wires fixation provides a more stable fixation against varus forces. This is important to prevent varus deformity, which is a clinically less tolerable deformity. However, considering that full-weight mobilization of patients is not allowed after surgery in pediatric supracondylar femur fractures, the surgeon should consider that K-wires can also be sent antegrade to decrease the risk of septic arthritis.

Outcomes of RigidFix Cross Pin Fixation in Femoral and Tibial Tunnel for Anterior Cruciate Ligament Reconstruction.

There is no clear consensus so far on which fixation method is most favorable for the tibial tunnel in anterior cruciate ligament reconstruction (ACLR). The purpose of this paper is to investigate the outcome of RigidFix cross pins fixation in the tibial tunnel and to explore the advantages of RigidFix applied both in the femoral and tibial tunnel with hamstring tendon graft in anterior cruciate ligament reconstruction. This retrospective study included 53 patients (male/female, 45/8) who underwent anterior cruciate ligament reconstruction using autologous hamstring tendons between January 2013 and December 2017 at our institute. The participants in group A (n = 36) received anterior cruciate ligament reconstruction with RigidFix cross pins fixation in both femoral and tibial tunnels, while those in group B (n = 17) with RigidFix cross pins fixation in the femoral tunnel and Interference screw fixation in the tibial tunnel. The visual analogue scale (VAS) score, International Knee Documentation Committee subjective knee form 2000 (IKDC2000) score, Lysholm knee scoring scale, Tegner activity score and the side-to-side difference were compared at 2 and 5 years postoperatively. The graft diameter, number of strands in graft and the average diameter of each strand were also compared between the two groups. The categorical parameters were analyzed by chi-square test and the continuous variables conforming to a normal distribution were analyzed by Student's t-test. At 2 years postoperation, the VAS score (1.61 ± 0.55), side-to-side difference (1.50 ± 0.58) in group A were significantly lower than that in group B, and the IKDC2000 score (88.81 ± 3.88), Tegner activity score (6.14 ± 0.60) in group A were significantly higher than that in group B. At 5 years postoperation, the VAS score (1.64 ± 0.68), side-to-side difference (1.73 ± 0.63) in group A were significantly lower than that in group B, and the IKDC2000 score (89.09 ± 3.85), Tegner activity score (6.58 ± 0.94) in group A were slso significantly higher than that in group B. There was statistical difference in the change of the side-to-side difference between the two groups (group A vs. B, 0.22 ± 0.08 vs. 0.34 ± 0.11, p < 0.001). There were also statistical differences in the graft diameter (group A vs. B, 7.83 ± 0.74 vs. 7.41 ± 0.51, p = 0,038), number of strands in graft (5.67 ± 0.72 vs. 4.00 ± 0.00, p < 0.001) and the average diameter of each strand (1.41 ± 0.22 vs. 1.85 ± 0.13, p < 0.001) between the two groups. RigidFix cross pins fixation in the tibial tunnel for anterior cruciate ligament reconstruction can achieve better 5-year results when compared with the interference screw, and the hamstring tendon can be folded into a thicker graft when RigidFix cross pins were applied in both femoral and tibial tunnels.

Treatment outcomes analysis in supracondylar humerus fractures in children and adolescents

Background. Distal epimetaphyseal humerus fractures in children and adolescents are relatively common injuries, with supracondylar and transcondylar fractures being the most prevalent. Among injuries to the distal humerus, these fractures occur most frequently and are one of the most common household injuries, composing 47.5–80 % of all intra-articular fractures of the elbow in children aged 3–12 years. Poor treatment outcomes range from 6.67 to 18.2 %. The aim is to study a current stage and therapeutic challenges in supracondylar humerus fractures in children and adolescents, and to find out optimal management based on analysis of the long-term treatment outcomes in this category of patients. Materials and methods. A retrospective study of treatment outcomes was conducted in 123 patients with supracondylar humerus fractures in 2019–2021. Average age of patients was 7.38 ± 0.34 years. Targeted clinical and instrumental examination have been performed in all patients. Fracture type was assessed based on AO Pediatric Comprehensive Classification of Long-Bone Fractures (PCCF). Mayo Elbow Performance Score was used to evaluate treatment outcomes. Results. Determining the type of supracondylar humerus fractures using AO PCCF compared to Gartland classification is justified as it allows for a more detailed assessment of the injury, thereby expanding the possibilities for developing individualized treatment strategies. Poor treatment outcomes with reduction + external immobilization constitute 3.7 % of cases, closed reduction + percutaneous fixation + external immobilization — 6.1 %, open reduction + pin fixation + external immobilization — 8.8 %. Conclusions. Supracondylar fractures are one of the most frequent injuries to the distal humerus and mostly occur in boys aged 4 to 9 years (58.3 % of cases). Fractures type II.1 (boys/girls ratio is 33.3/37.3 %) and III.1 (23.7/27.6 %) are dominating. Deepening the knowledge through anatomical and biomechanical studies of the structures with crossed and coronal pins will improve the existing fixation devices and will become the basis for the development of new ones, which will significantly improve treatment outcomes in supracondylar humerus fractures in children and adolescents.

Carbon-infiltrated carbon nanotubes inhibit the development of Staphylococcus aureus biofilms

Staphylococcus aureus forms biofilms that cause considerable morbidity and mortality in patients who receive implanted devices such as prosthetics or fixator pins. An ideal surface for such medical devices would inhibit biofilm growth. Recently, it was reported that surface modification of stainless steel materials with carbon-infiltrated carbon nanotubes (CICNT) inhibits the growth of S. aureus biofilms. The purpose of this study was to investigate this antimicrobial effect on titanium materials with CICNT coated surfaces in a variety of surface morphologies and across a broader spectrum of S. aureus isolates. Study samples of CICNT-coated titanium, and control samples of bare titanium, a common implant material, were exposed to S. aureus. Viable bacteria were removed from adhered biofilms and quantified as colony forming units. Scanning electron microscopy was used to qualitatively analyze biofilms both before and after removal of cells. The CICNT surface was found to have significantly fewer adherent bacteria than bare titanium control surfaces, both via colony forming unit and microscopic analyses. This effect was most pronounced on CICNT surfaces with an average nanotube diameter of 150 nm, showing a 2.5-fold reduction in adherent bacteria. Since S. aureus forms different biofilm structures by isolate and by growth conditions, we tested 7 total isolates and found a significant reduction in the biofilm load in six out of seven S. aureus isolates tested. To examine whether the anti-biofilm effect was due to the structure of the nanotubes, we generated an unstructured carbon surface. Significantly more bacteria adhered to a nonstructured carbon surface than to the 150 nm CICNT surface, suggesting that the topography of the nanotube structure itself has anti-biofilm properties. The CICNT surface possesses anti-biofilm properties that result in fewer adherent S. aureus bacteria. These anti-biofilm properties are consistent across multiple isolates of S. aureus and are affected by nanotube diameter. The experiments performed in this study suggest that this effect is due to the nanostructure of the CICNT surface.

MEDIUM-TERM OUTCOMES FOR SURGICAL VERSUS NONOPERATIVE TREATMENT FOR BENNETT'S FRACTURES OF THE THUMB METACARPAL: A MATCHED COHORT STUDY

There is no agreement as to the superiority or specific indications for cast treatment, percutaneous pinning or open fracture fixation for Bennett's fractures of the thumb metacarpal. We undertook this study to compare the outcomes of treatment for patients treated for Bennett's fracture in the medium term.We reviewed 33 patients treated in our unit for a bennett's fracture to the thumb metacarpal with closed reduction and casting. Each patient was matched with a patient treated surgically. Patients were matched for sex, age, Gedda grade of injury and hand dominance. Patients were reviewed at a minimum of 5-years and 66-patients were reviewed in total. Patients were examined clinically and also asked to complete a DASH questionnaire score and the brief Michigan hand questionnaire. Follow up plain radiographs were taken of the thumb and these were reviewed and graded for degenerative change using the Eaton-Littler score.Sixty-six patients were included in the study, with 33 in the surgical and non-surgical cohorts respectively. The average age was 39 years old. In each cohort, 12/33 were female, 19/33 were right-handed with 25% of individuals injuring their dominant hand. In each coort there were 16 Grade 1 fractures, 4 Grade 2 and 13 Grade 3 fractures. There was no difference between the surgically treated and cast-treatment cohorts of patients when radiographic arthritis, pinch grip, the brief Michigan Hand Questionnaire and pain were assessed at final review. The surgical cohort had significantly lower DASH scores at final follow-up. There was no significant difference in the normalised bMHQ scores.Our study was unable to demonstrate superiority of either operative or non-operative fracture stabilization. Patients in the surgical cohort reported superior satisfaction and DASH scores but did not demonstrate any superiority in any other objectively measured domain.

EVALUATION OF THE SELF-DRILLING, SELF-TAPPING SCHANZ PIN THREAD PATTERNS ON THE NEAR CORTEX WHEN INSERTED IN BONE WITHOUT PRE-DRILLING

The external fixator is an invaluable device when treating acute complex trauma and in limb reconstruction. It is therefore important to ensure its efficient and safe application to avoid complications. A lot of research has been done to evaluate the factors around external fixator stability, pin site infections and more is still being done to understand pin loosening. The purpose of this study was to evaluate other factors that may contribute in external fixator pin loosening. The aim was to evaluate if the different Schanz pin insertion techniques contribute to pin loosening.Two tibia diaphyses from two cadavers were each divided into three sections. Three different drilling techniques were repeated in each of the sections. A total of 36 Schanz pins were inserted and a section cut out of the bone in front of the pins was done allowing visual inspection of the pin hole for features of thread stripping. These features were predefined as thread pattern disruption, smoothening and shallow imprint on the cortex.Evidence of pin thread stripping was seen in all of the pin insertion techniques. The first method where the hole was pre-drilled and pin inserted with the drill showed 100% thread stripping. The second method of pre-drilling and hand insertion showed the least amount with 16.7% of pin stripping noted and 66.7% pin thread stripping was observed when inserting the pin with power without pre-drilling the pilot hole using the third method.Different pin insertion techniques result in varying amounts of pin thread stripping. The most amount of thread stripping occurs when a Schanz pin is inserted with power after pre-drilling. This finding, although not measured scientifically, supports the current recommendation of pre-drilling and manual insertion of the pin. In future, more scientific measurement are necessary to quantify these findings and assess their clinical significance.