Fixation Methods Research Articles

Advancements in pelvic ring fracture surgery: Assessing INFIX screw placement accuracy with CT navigation

The management of unstable pelvic ring fractures, typically resulting from high-energy trauma, presents a significant clinical challenge due to the complexity of injuries. While effective in many cases, the traditional stabilization methods are fraught with various complications that can significantly impact patient recovery and quality of life (QOL). This study aims to evaluate the efficacy and precision of the anterior subcutaneous internal fixator (INFIX) technique when used with intraoperative computed tomography (CT) navigation, a novel approach intended to mitigate the limitations of conventional treatment modalities.Our retrospective case series encompasses 43 patients who sustained traumatic pelvic injuries and were subsequently treated with the INFIX technique from December 2020 to January 2024. The focus of this analysis was to assess the accuracy of INFIX screw placement facilitated by intraoperative CT navigation.A total of 81 INFIX screws were inserted, and our study findings reveal a high level of precision in screw placement, with only one screw deviating, resulting in an inaccuracy rate of merely 1.2 %. This highlights the significant advantage provided by intraoperative CT navigation. The high level of accuracy not only enhances the stability of the pelvic fixation but also substantially reduces the risk of complications commonly associated with screw misplacement, such as abdominal damage, vascular injury, and issues related to incorrect hardware positioning.In conclusion, the integration of the INFIX technique with intraoperative CT navigation in the treatment of unstable pelvic ring fractures represents a significant advancement in orthopedic trauma surgery. This study provides compelling evidence supporting the efficacy and precision of this approach, suggesting its potential as a superior alternative to traditional fixation methods. Further research, ideally through prospective studies involving larger patient cohorts, is needed to validate these findings and explore the long-term implications of this technique on patient recovery and QOL.

Finite element analysis of modified Slongo's external fixation in the treatment of supracondylar humeral fractures in older children.

Older children over 8 years old are at higher risk of elbow joint stiffness after treatment of supracondylar humeral fractures. The objective of this study was to improve the Slongo's external fixation system for treating supracondylar humeral fractures in older children. This would be achieved by increasing fixation strength and providing a theoretical basis through finite element analysis and mechanical testing. A 13-year-old female patient with a history of previous fracture was selected for CT data processing to create a three-dimensional model of the distal humerus fracture. Two internal fixation models were established, using the Slongo's external fixation method with Kirschner wire (Group A) and modifying the Slongo's external fixation (Kirschner wire tail fixation) (Group B). The fracture models were then subjected to mechanical loading analysis using Finite Element Analysis Abaqus 6.14 software to simulate separation, internal rotation, and torsion loads. A PVC humeral bone model was used to create a supracondylar fracture model, and the A and B internal fixation methods were applied separately. The anterior-posterior and torsional stresses were measured using the Bose Electroforce3510 testing system, followed by a comparative analysis. The finite element simulation results showed that under the same tensile, torsion, and inversion forces, the osteotomy model fixed with Kirschner wire at the distal end in Group B exhibited smaller tensile stress and deformation compared to the unfixed osteotomy model in Group A. This indicated that the fixation strength of Group B was superior to that of Group A. According to the test results of the Bose Electroforce3510 testing system, a simple linear regression analysis was conducted using SPSS software. The K values of rotation angle-torque tests and front and rear displacement-stress tests were calculated for Groups A and B, with Group B showing higher values than Group A. The results of this study supported the significantly enhanced biomechanical reliability and stability of fracture fixation in Group B, which utilized the modified Slongo's external fixation (Kirschner wire tail fixation). This optimized method provides a new choice for the clinical treatment of supracondylar humeral fractures in older children, backed by both clinical evidence and theoretical basis.

Biomechanical analysis of plate versus K-wire fixation for metacarpal shaft fractures with wedge-shaped bone defects

BackgroundMetacarpal shaft fracture is a common type of hand fracture. Numerous studies have explored fixing transverse fractures in the midshaft of the metacarpal bone. However, this section of the metacarpal bone is often susceptible to high-energy injury, resulting in comminuted fracture or bone loss. In such cases, wedge-shaped bone defects can develop in the metacarpal shaft, increasing the difficulty of performing fracture fixation. Notably, the research on this type of fracture fixation is limited. This study compared the abilities of four fixation methods to fix metacarpal shaft fractures with wedge-shaped bone defects.MethodsIn total, 28 artificial metacarpal bones were used. To create wedge-shaped bone defects, an electric saw was used to create metacarpal shaft fractures at the midshaft of each bone. The artificial metacarpal bones were then divided into four groups for fixation. The bones in the first group were fixed with a dorsal locked plate (DP group), those in the second group were fixed with a volar locked plate (VP group), and those in the third group were fixed by combining dorsal and volar locked plates (DP + VP group), and those in the fourth group were fixed with two K-wires (2 K group). Cantilever bending tests were conducted using a material testing machine to measure yielding force and stiffness. The four groups’ fixation capabilities were then assessed through analysis of variance and Tukey’s test.ResultsThe DP + VP group (164.1±44.0 N) achieved a significantly higher yielding force relative to the 2 K group (50.7 ± 8.9 N); the DP group (13.6 ± 3.0 N) and VP group (12.3 ± 1.0 N) did not differ significantly in terms of yielding force, with both achieving lower yielding forces relative to the DP + VP group and 2 K group. The DP + VP group (19.8±6.3 N/mm) achieved the highest level of stiffness, and the other three groups did not differ significantly in terms of stiffness (2 K group, 5.4 ± 1.1 N/mm; DP group, 4.0 ± 0.9 N/mm; VP group, 3.9 ± 1.9 N/mm).ConclusionsThe fixation method involving the combined use of dorsal and volar locked plates (DP + VP group) resulted in optimal outcomes with respect to fixing metacarpal shaft fractures with volar wedge bone defects.

Low reoperation rate after fixation of displaced femoral neck fractures with the femoral neck system (FNS).

Operative fixation of femoral neck fractures (FNFs) remains challenging. Complications are not infrequent, especially in displaced patterns. Numerous fixation techniques have been previously described in the literature; however, there remains a paucity of data regarding outcomes of these injuries treated with the femoral neck system (FNS). Patients with a displaced FNF (OTA/AO 31B) treated with the FNS at a single level 1 academic trauma center between 1/1/2019 and 1/1/2023 were identified. Radiographs were reviewed to assess fracture displacement, location, and characteristics. Patient records were further reviewed to assess for complications, reoperations, and osseous union. Forty-three patients (65% male) with 44 FNFs were identified with a mean age of 35.0years (range, 13-61years). Two patients developed a deep infection requiring surgical debridement, four patients underwent a total hip arthroplasty, and one patient underwent a valgus intertrochanteric osteotomy for nonunion. There were three cases of femoral head AVN. Mean follow-up was 482.5days among all patients, and 36 fractures had at least 6months of follow-up or reached bony union. Here, we present a series of patients treated with the FNS for internal fixation and report a 18% reoperation rate. This is lower than the average rate that has been previously reported in similar patient populations in the literature treated with alternative methods of internal fixation. Thus, the FNS appears to be a safe and effective option for treatment of these injuries.

Are current rates of uncemented fixation in total hip arthroplasty supported by the literature? An update on the uncemented paradox.

The optimal fixation method in total hip arthroplasty (THA) remains controversial. Initial concerns related to the long-term performance of cement fixation as well as cement disease led to the development of cementless implants, and registry data has indicated that the use of this type of fixation has increased in recent years. However, data from these same registries has not shown any improvement in outcomes when compared to cement fixation. On the contrary, while similar outcomes are seen when comparing these fixation types in younger patients (<70 years of age), cementless fixation has shown increased implant failure and revision rates in elderly patients (>70 years of age). Given the increased projected volume of THA in the United States over the next decade, it is important to utilise available data to make clinical decisions that minimise not only individual patient harm, but also the burden on the healthcare system itself. This review provides an overview of currently available outcomes data comparing cement and cementless fixation, as well as an updated analysis of current trends in fixation use in THA. We furthermore provide a comprehensive technique guide to help surgeons optimise cement fixation of the femoral component for THA and hemiarthroplasty.

СРАВНИТЕЛЬНАЯ ХАРАКТЕРИСТИКА МЕТОДОВ ИММОБИЛИЗАЦИИ ОТЛОМКОВ ПРИ ПЕРЕЛОМАХ НИЖНЕЙ ЧЕЛЮСТИ

Item. A review of the literature is presented on the current problem of maxillofacial surgery – methods of fixation of bone fragments in fractures of the lower jaw. The purpose of the study is to study publications on methods of fixation of fragments in fractures of the lower jaw in the comparative aspect of their influence on the clinical course. Methodology. The publications of domestic and foreign authors on modern methods of fixation of bone fragments in fractures of the lower jaw were studied, and a comparative analysis of their effectiveness was carried out. Results. Currently, orthopedic and surgical methods of immobilization of bone fragments are used, which are used both in isolation and in various combinations. During surgical treatment with the help of mini-plates, it is possible to perform optimal reposition and stable fixation of fragments, however, the traumatic nature of the operation, leading to bone hypoxia, slows down the processes of reparative osteogenesis and leads to the development of postoperative complications. The use of bone glue-cement makes it possible to achieve reliable fixation of bone fragments, accelerate the formation of a callus. At the same time, there is no need to remove the glue, since it is a biodegradable material. Conclusions 1. None of the currently used methods of fixation of bone fragments in clinical practice for fractures of the mandible, both orthopedic and surgical, as well as in their combination, can fully meet the optimal conditions of reparative osteogenesis. 2. A promising alternative method is the use of bone adhesives that fill the bone voids between fragments, which contributes to their stable fixation and reparative osteogenesis, biodegrading simultaneously with the formation of a callus.

Sand control during gas production from marine hydrate reservoirs by using microbial-induced carbonate precipitation technology: A feasibility study

Sand production is one of the bottleneck problems restricting the safe and efficient production of marine hydrate reservoirs. Current research on this issue mainly focuses on the active sand control methods such as screen mesh and gravel packing, however, passive methods are rarely reported. In this study, a novel sand control strategy which uses microbial-induced carbonate precipitation (MICP) technology to reinforce hydrate reservoirs around the well is proposed. Based on the geological data of hydrate reservoirs in Japan, a reservoir-scale microbial reaction-migration model is established. The feasibility of MICP reinforcement to prevent sand production is demonstrated by the combinations of indoor triaxial testing, productivity prediction and microscopic sand production prediction. The results show that the MICP technology can effectively enhance reservoir strength, and has a negligible impact on the gas recovery. Although the calcium carbonate generated will slightly decrease the porosity and permeability, the cumulative gas production does not significantly decrease and the water extraction is also prevented. Most importantly, the amount of sand production can sharply reduce because of the cementation of calcium carbonate among sand particles. Additionally, the effectiveness and applicability can be improved by selecting appropriate bacteria fixation methods and grouting pressure at different stages.

Study on the therapeutic effect of Kirschner wire tension band combined with anchor cross-stitch technique in the treatment of comminuted patellar inferopolar fractures.

Fractures of the inferior patellar pole, unlike other patellar fractures, present challenges for traditional surgical fixation methods. This article introduces the clinical technique and outcomes of using Kirschner wire tension band combined with anchor screw cross-stitch fixation for comminuted inferior patellar pole fractures. This retrospective case series study included 14 patients with comminuted inferior patellar pole fractures treated at our institution from September 1, 2020, to April 30, 2022. All patients underwent surgery using the Kirschner wire tension band with anchor screw cross-stitch technique. Follow-up assessments involved postoperative X-rays to evaluate fracture healing, as well as clinical parameters such as healing time, Visual Analog Scale (VAS) scores, range of motion (ROM), and Bostman scores. All patients were followed for an average of over 12 months, with no cases of internal fixation failure. Knee joint stability and function were excellent. X-rays revealed an average healing time of approximately 10.79 ± 1.53 weeks, hospitalization lasted 5.64 ± 1.15 days, surgery took approximately 37.86 ± 5.32 minutes, and intraoperative blood loss was 33.29 ± 8.15 ml. One patient experienced irritation from the internal fixation material. At the final follow-up, the Bostman score averaged 28.29 ± 0.83, knee joint flexion reached 131.07° ± 4.88°, all patients achieved full knee extension, and the VAS score was 0.36 ± 0.63. Kirschner wire tension band with anchor screw cross-stitch fixation for comminuted inferior patellar pole fractures delivered satisfactory clinical outcomes. This surgical method, characterized by its simplicity and reliability, is a valuable addition to clinical practice.

The effect of Ding’s screws and tension band wiring for treatment of olecranon fractures: a biomechanical study

Although tension band wiring (TBW) is popular and recommended by the AO group, the high rate of complications such as skin irritation and migration of the K-wires cannot be ignored. Ding’s screw tension band wiring (DSTBW) is a new TBW technique that has shown positive results in the treatment of other fracture types. The objective of this study was to evaluate the stability of DSTBW in the treatment of olecranon fractures by biomechanical testing. We conducted a Synbone biomechanical model by using three fixation methods: DSTBW, intramedullary screw and tension band wiring (IM-TBW), and K-wire TBW, were simulated to fix the olecranon fractures. We compared the mechanical stability of DSTBW, IM-TBW, and TBW in the Mayo Type IIA olecranon fracture Synbone model using a single cycle loading to failure protocol or pullout force. During biomechanical testing, the average fracture gap measurements were recorded at varying flexion angles in three different groups: TBW, IM-TBW, and DSTBW. The TBW group exhibited measurements of 0.982 mm, 0.380 mm, 0.613 mm, and 1.285 mm at flexion angles of 0°, 30°, 60°, and 90° respectively. The IM-TBW group displayed average fracture gap measurements of 0.953 mm, 0.366 mm, 0.588 mm, and 1.240 mm at each of the corresponding flexion angles. The DSTBW group showed average fracture gap measurements of 0.933 mm, 0.358 mm, 0.543 mm, and 1.106 mm at the same flexion angles. No specimen failed in each group during the cyclic loading phase. Compared with the IM-TBW and TBW groups, the DSTBW group showed significant differences in 60° and 90° flexion angles. The mean maximum failure load was 1229.1 ± 110.0 N in the DSTBW group, 990.3 ± 40.7 N in the IM-TBW group, and 833.1 ± 68.7 N in the TBW group. There was significant difference between each groups (p < 0.001).The average maximum pullout strength for TBW was measured at 57.6 ± 5.1 N, 480.3 ± 39.5 N for IM-TBW, and 1324.0 ± 43.8 N for DSTBW. The difference between maximum pullout strength of both methods was significant to p < 0.0001. DSTBW fixation provides more stability than IM-TBW and TBW fixation models for olecranon fractures.

Fixation of a chondral lateral femoral condyle fracture in a 13-year-old boy following patella dislocation using a new suture technique.

Osteochondral or, even more rarely, purely chondral fractures of the lateral femoral condyle following patella dislocation in adolescents are relatively infrequent. Various fixation methods are described in the literature, ranging from traditional screws to bioabsorbable constructs or the use of anchors. Each method possesses its own advantages and limitations. Here, we present a case involving a 13-year-old boy with a large purely chondral fracture of the lateral femoral condyle after patella dislocation, initially overlooked. We introduce a cost-effective suture-bridge technique for the fixation of this fracture, which eliminates the need for a second operation and has yielded favorable outcomes. It is important to know that fractures of this type can be easily overlooked, necessitating a high index of suspicion and the utilization of advanced imaging techniques to prevent potential long-term catastrophic outcomes for the knee joint.

Transulnar basal coronoid fractures – Surgical tips and tricks

Transulnar basal coronoid fractures of the elbow are complex injuries in which there is a transulnar fracture dislocation of the elbow, and the coronoid is fractured and not attached to either the olecranon fragment or the metaphyseal segment. These fractures are difficult to manage and can lead to poor outcomes if not adequately addressed. This technical note aims to introduce an approach to their operative management. Due to the variety of fracture patterns and degree of comminution, the sequence of intraoperative management as well as fixation methods may vary. The utilization of this technical note will guide surgeons through the optimal management of these injuries to achieve stable fixation that will allow early range of motion.

Latarjet procedure: biomechanical evaluation of 2-screw coracoid fixation

Coracoid nonunion is a relevant complication following the Latarjet procedure and is influenced by multiple factors, including the method of graft fixation. The purpose of this study was to evaluate and characterize the biomechanical properties of various two-screw fixation constructs used for coracoid graft fixation in the Latarjet procedure. Forty model scapulae (Sawbones Inc., Vashon, WA, USA) were used for this study. A 15% anterior inferior glenoid bone defect was created. The coracoid was osteotomized at the juncture of the vertical and horizontal aspects, transferred to the anterior-inferior edge of the glenoid, and fixed with either two 3.5mm fully threaded cannulated cortical screws, two 3.5mm fully threaded solid cortical screws, two 3.5mm partially threaded cannulated screws, or two 4.5mm partially threaded malleolar screws (MS). Biomechanical testing was performed with an Instron material testing machine (Instron Corp., Norwood, MA, USA) by applying loads to the lateral aspect of the transferred coracoid graft. The constructs were preconditioned with nondestructive cyclical loading (0N-20N) to determine construct stiffness. After 100 cycles of dynamic loading, the construct was loaded to failure to determine ultimate failure load, yield displacement, and mode of failure. All failures were associated with plastic deformation of the screws and coracoid graft fracture. There was a significantly lower initial stiffness for partially threaded cannulated screws compared to MS (186±49.3N/mm vs. 280±65.5N/mm, P=.01) but no significant differences among the other constructs. There was no difference in ultimate failure load (P=.18) or yield displacement (P=.05) among constructs. Two screw coracoid fixation of the coracoid in a simulated classic Latarjet procedure with 3.5mm fully threaded cortical and cannulated screws is comparable to 4.5mm MS in strength, stiffness, and displacement at failure. On the other hand, partially threaded 3.5mm cannulated screws provide inferior fixation stiffness and could potentially affect clinical outcomes.

A novel custom bent 27G needle-guided suture snare technique for scleral fixation of posterior chamber intraocular lenses

PURPOSE: To describe a custom bent 27G needle-guided suture snare technique for scleral fixation of posterior chamber intraocular lenses (PCIOL). METHODS: An 8-0 polypropylene suture was threaded into the lumen of a custom bent 27G needle, and the needle tip was advanced into the eye from the IOL fixation point. The suture was threaded through the posterior limbal incision inside the IOL haptic loop and pulled out. The needle tip was advanced into the eye again, going around the IOL haptic loop through the same limbal incision. The suture was threaded in again, and the needle was withdrawn from the eye, completing fixation of the IOL haptic loop. The suture knot was buried in the stroma of the sclera. RESULTS: The technique was performed in 10 eyes of 10 patients, with a preoperative logarithm of the minimum resolution angle corrected visual acuity of 0.73 ± 0.55 (Snellen 20/107), improvement of 0.24 ± 0.27 (Snellen 20/35) at the final follow-up visit, and a mean postoperative PCIOL tilt of 2.78 ± 1.32°. There were no cases of pupillary capture or suture-related complications during follow-up. CONCLUSION: The curved needle-guided suture snare technique provides a simple minimally-invasive method of scleral suture fixation of PCIOL.

Acetabular component liner exchange with highly crosslinked polyethylene for wear and osteolysis.

Isolated acetabular liner exchange with a highly crosslinked polyethylene (HXLPE) component is an option to address polyethylene wear and osteolysis following total hip arthroplasty (THA) in the presence of a well-fixed acetabular shell. The liner can be fixed either with the original locking mechanism or by being cemented within the acetabular component. Whether the method used for fixation of the HXLPE liner has any bearing on the long-term outcomes is still unclear. Data were retrieved for all patients who underwent isolated acetabular component liner exchange surgery with a HXLPE component in our institute between August 2000 and January 2015. Patients were classified according to the fixation method used (original locking mechanism (n = 36) or cemented (n = 50)). Survival and revision rates were compared. A total of 86 revisions were performed and the mean duration of follow-up was 13 years. A total of 20 patients (23.3%) had complications, with dislocation alone being the most common (8.1%; 7/86). Ten patients (11.6%) required re-revision surgery. Cementing the HXLPE liner (8.0%; 4/50) had a higher incidence of re-revision due to acetabular component liner-related complications than using the original locking mechanism (0%; 0/36; p = 0.082). Fixation using the original locking mechanism was associated with re-revision due to acetabular component loosening (8.3%; 3/36), compared to cementing (0%; 0/50; p = 0.038). Overall estimated mean survival was 19.2 years. There was no significant difference in the re-revision rate between the original locking mechanism (11.1%; 4/36) and cementing (12.0%; 6/50; p = 0.899). Using Kaplan-Meier survival analysis, the revision-free survival of HXLPE fixed with the original locking mechanism and cementing was 94.1% and 93.2%, respectively, at ten years, and 84.7% and 81.3%, respectively, at 20 years (p = 0.840). The re-revision rate and the revision-free survival following acetabular component liner exchange revision surgery using the HXLPE liner were not influenced by the fixation technique used. Both techniques were associated with good survival at a mean follow-up of 13 years. Careful patient selection is necessary for isolated acetabular component liner exchange revision surgery in order to achieve the best outcomes.

Posterior Shoulder Instability, Part II—Glenoid Bone Grafting, Glenoid Osteotomy, and Rehabilitation/Return to Play—An International Expert Delphi Consensus Statement

The purpose of this study was to establish consensus statements on glenoid bone-grafting, glenoid osteotomy, rehabilitation, return to play, and follow-up for posterior shoulder instability. A consensus process on the treatment of posterior shoulder instability was conducted, with 71 shoulder/sports surgeons from 12 countries participating based on their level of expertise in the field. Experts were assigned to one of 6 working groups defined by specific subtopics within posterior shoulder instability. Consensus was defined as achieving 80-89% agreement, whereas strong consensus was defined as 90-99% agreement, and unanimous consensus was indicated by 100% agreement with a proposed statement. All of the statements relating to rehabilitation, return to play, and follow-up achieved consensus. There was unanimous consensus that the following criteria should be considered: restoration of strength, range of motion, proprioception, and sport-specific skills, with a lack of symptoms. There is no minimum time point required to return to play. Collision athletes and military athletes may take longer to return because of their higher risk for recurrent instability, and more caution should be exercised in clearing them to return to play, with elite athletes potentially having different considerations in returning to play. The relative indications for revision surgery are symptomatic apprehension, multiple recurrent instability episodes, further intra-articular pathologies, hardware failure, and pain. The study group achieved strong or unanimous consensus on 59% of statements. Unanimous consensus was reached regarding the criteria for return to play, collision/elite athletes having different considerations in return to play, indications for revision surgery, and imaging only required as routine for those with glenoid bone-grafting/osteotomies at subsequent follow-ups. There was no consensus on optimal fixation method for a glenoid bone-block, the relative indications for glenoid osteotomy, whether fluoroscopy is required or if the labrum should be concomitantly repaired. Level V Expert Opinion.

Biomechanical comparisons of F.E.R.I. techniques with different type of intramedullary screws fixation for Jones fractures.

Introduction: Jones fractures frequently fail to unite, and adequate fixation stability is crucial. This study aimed to elucidate the biomechanical stability of various intramedullary screw fixation constructs. Methods: Jones fracture model over the proximal 5th metatarsal of artificial bone was created in all specimens. Six groups were divided based on varied screw constructs with different screw lengths, either 30 or 40mm, including cannulated screws-C30 and C40 groups, one high-resistance suture combined with intramedullary cannulated screws (F.E.R.I. technique)-CF30 and CF40 groups, and second-generation headless compression screws (SG-HCS) -HL30 and HL40 groups. Mechanical testing was conducted sequentially, and the maximal force (N) and stiffness (N/mm) of all constructs were recorded. Results: The maximal force (N) at 1.0mm downward displacement in C30, C40, CF30, CF40, HL30, and HL40 groups were 0.56 ± 0.02, 0.49 ± 0.02, 0.65 ± 0.02, 0.49 ± 0.01, 0.68 ± 0.02, and 0.73 ± 0.02, respectively, and the stiffness (N/mm) in subgroups were 0.49 ± 0.01, 0.43 ± 0.01, 0.67 ± 0.01, 0.42 ± 0.01, 0.61 ± 0.01, and 0.58 ± 0.02, respectively. SG-HCS subgroups exhibited greater maximal force and stiffness than conventional cannulated screws. Screws of 30mm in length demonstrated better stability than all 40mm-length screws in each subgroup. In C30 fixation, the stiffness and maximum force endured increased by 1.16 and 1.12 times, respectively, compared with the C40 fixation method. There were no significant differences between CF30 and SG-HCS groups. Only the F.E.R.I technique combined with the 4.5mm cannulated screw of 30mm in length increased the biomechanical stability for Jones fractures. Discussion: These biomechanical findings help clinicians decide on better screw fixation options for greater stability in Jones fractures, especially when large-diameter screws are limited in use. However, this biomechanical testing of intramedullary screw fixation on Jones fracture model lacks clinical validation and no comparisons to extramedullary plate fixations. Moving forward, additional clinical and biomechanical research is necessary to validate our findings.

Biomechanical evaluation of the modified lasso technique

BackgroundThe Terrible Triad of the elbow is a constellation of elbow dislocation, radial head fracture and coronoid process fracture. A common type of coronoid fracture documented with this triad is type II Regan-Morrey coronoid fractures. The preferred fixation method for this fracture type is the lasso technique, medial-lateral tunnel orientation being the traditional approach. Considering elbow anatomy, we saw an opportunity to potentially improve fixation by altering the suture lasso tunnel orientation to a proximal-distal orientation. HypothesisTwo tunnels in the proximal-distal direction would result in greater biomechanical stability as compared to the traditional lasso technique. Material and methodsA type 2 Regan-Morrey fracture was created in 12 fresh frozen cadaveric elbows at 50% of the coronoid height using an oscillating saw. The humero-ulnar joint was placed in 0 degrees flexion then loaded at a rate of 10mm/min to failure. ResultsThe control technique (medio-lateral tunnels) showed failure load of 150±81N that was not significantly different (p=0.825) than the 134±116N measured for the modified technique (distal-proximal tunnels). The portion of the load-displacement curve used to calculate stiffness was linear (R^2=0.94±0.04) with determination coefficients that did not differ between the two groups (p=0.351). For stiffness, we measured 17±13N/mm and 14±12N/mm respectively for control and modified techniques that did not result in a significant difference (p=0.674). ConclusionIn this attempt to improve the shortcomings of the lasso technique, we found that changing from medio-lateral to proximal-distal drilling directions did not result in an appreciable biomechanical benefit. Level of evidenceBasic science study; Biomechanics.

A RANDOMIZED CONTROLLED TRIAL INVESTIGATING FUNCTIONAL RECOVERY AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION USING A SINGLE VERSUS DOUBLE TENDON HARVEST

INTRODUCTION &amp; AIMS Anterior cruciate ligament (ACL) tears are common. While surgical reconstruction (ACLR) is commonly advocated and a hamstring autograft is the popular choice, hamstring tendon harvest has been linked to reduced hamstring strength and ongoing donor site pain. While traditional surgical techniques required a harvest of both semitendinosus/gracilis tendons, modern harvesting and fixation methods permit a shorter, broader harvest of semitendinosus only. This study investigated donor site pain, strength and functional recovery in patients undergoing ACLR via a single (ST) versus dual (DT) tendon hamstring harvest. METHODS This prospective randomized controlled trial (RCT) allocated 138 patients to ACLR with one of the two hamstring tendon graft options (ST=71, DT=67) followed by a structured rehabilitation program. Patients were assessed pre-surgery and at 3, 6, and 12 months, with a range of patient-reported outcome measures (PROMs) including a validated donor-site morbidity score. Graft laxity, peak isokinetic knee extensor and flexor strength and a 6-hop performance battery were assessed. Limb Symmetry Indices (LSIs) were calculated. RESULTS All PROMs significantly improved (p&amp;lt;0.0001) and were largely similar between groups (p&amp;gt;0.05), apart from significantly less graft morbidity reported in the ST group (p=0.001). No group differences were observed for knee laxity or LSIs for hop measures (p&amp;gt;0.05), nor the LSIs for peak knee flexor (p=0.113) or extensor (p=0.286) torque. CONCLUSION While the ST ACLR group reported significantly less harvest site morbidity, no other subjective or functional differences were observed in patients undergoing ACLR with either a single or dual hamstring tendon autograft harvest.

549: Differences between two posture fixation methods in VMAT for cervical cancer

549: Differences between two posture fixation methods in VMAT for cervical cancer

Complex Elbow Fracture-Dislocations: An Algorithmic Approach to Treatment.

Elbow stability arises from a combination of bony congruity, static ligamentous and capsular restraints, and dynamic muscular activation. Elbow trauma can disrupt these static and dynamic stabilizers leading to predictable patterns of instability; these patterns are dependent on the mechanism of injury and a progressive failure of anatomic structures. An algorithmic approach to the diagnosis and treatment of complex elbow fracture-dislocation injuries can improve the diagnostic assessment and reconstruction of the bony and ligamentous restraints to restore a stable and functional elbow. Achieving optimal outcomes requires a comprehensive understanding of pertinent local and regional anatomy, the altered mechanics associated with elbow injury, versatility in surgical approaches and fixation methods, and a strategic rehabilitation plan.