Majority of osteoporosis related fractures are treated surgically using metallic fixation devices. Anchorage of fixation devices is sometimes challenging due to poor osteoporotic bone quality that can lead to failure of the fracture fixation. Using a rat osteoporosis model, we employed neutron tomography and histology to study the biological effects of implant augmentation using an isothermally setting calcium sulphate/hydroxyapatite (CaS/HA) biomaterial with synthetic HA particles as recruiting moiety for systemically administered bisphosphonates. Using an osteoporotic sawbones model, we then provide a standardized method for the delivery of the CaS/HA biomaterial at the bone-implant interface for improved mechanical anchorage of a lag-screw commonly used for hip fracture fixation. As a proof-of-concept, the method was then verified in donated femoral heads and in patients with osteoporosis undergoing hip fracture fixation. We show that placing HA particles around a stainless-steel screw in-vivo, systemically administered bisphosphonates could be targeted towards the implant, yielding significantly higher peri-implant bone formation compared to un-augmented controls. In the sawbones model, CaS/HA based lag-screw augmentation led to significant increase (up to 4 times) in peak extraction force with CaS/HA performing at par with PMMA. Micro-CT imaging of the CaS/HA augmented lag-screws in cadaver femoral heads verified that the entire length of the lag-screw threads and the surrounding bone was covered with the CaS/HA material. X-ray images from fracture fixation surgery indicated that the CaS/HA material could be applied at the lag-screw-bone interface without exerting any additional pressure or risk of venous vascular leakage.: We present a new method for augmentation of lag-screws in fragile bone. It is envisaged that this methodcould potentially reduce the risk of fracture fixation failure especially when HA seeking “bone active” drugs are used systemically

Abstract. Objectives. Osteoporotic fractures tend to be more challenging than fractures in healthy bone and the efficacy of metal screw fixation decreases with decreasing bone mineral density making it more difficult for such screws to gain purchase. This leads to increased complication rates such as malunion, non-union and implant failure (1). Bioresorbable polymer devices have seen clinical success in fracture fixation and are a promising alternative for metallic devices but are rarely used in the osteoporotic population. To address this, we are developing a system that may allow osteoporotic patients to avail of bioresorbable devices (2) but it is important to establish if patients have any reservations about having a plastic resorbable device instead of a metal one. Therefore the aim of this study was to explore the acceptability of bioresorbable fracture fixation devices to people with osteoporosis. Methods. A cross sectional descriptive study was conducted in a UK wide population using convenience sampling. An online survey comprising nine survey questions and nine demographic questions was developed in Microsoft Teams and tested for face validity in a small pilot study (n=6). Following amendments and ethical approval, the survey was distributed by the Royal Osteoporosis Society on their website and social media platforms. People were invited to take part if they lived in the UK, were over 18 years old and had been diagnosed with osteoporosis. The survey was open for three weeks in May 2023. Responses were analysed using descriptive statistics. Results. There were 112 responses. Eight participants had not been diagnosed with osteoporosis and therefore did not meet the study criteria. Of the remaining 104, 102 were female and 2 were male and 102 were white (2 chose not to disclose their ethnicity). The majority of participants were aged 55–64 (34.6%) or 65–74 (37.5%), were college/university educated (38.5%) and had previously sustained a fragility fracture (52.9%). Only 3.9% of participants had heard of bioresorbable fracture fixation devices compared to 62.5% for metal devices. Most people were unsure if they would trust one type of device over the other (58.7%) and would ask for more information if their surgeon were to suggest using a bioresorbable device to fix their fracture (61.5%). The most commonly reported concerns were about device safety and efficacy: toxicity of the degradation products and the device breaking down too early before the fracture had healed. Two participants cited environmental concerns about increased use of plastics as a reason they would decline such a device. Conclusions. As expected, participants had little to no knowledge of bioresorbable polymer fixation devices. In general, they were willing to be guided by their surgeon but would require supporting information on the safety and efficacy of their long-term use. The results of this study show that it will be important to have relevant and understandable information to give patients when recommending these devices as treatments to ensure and support a shared-decision approach to patient care. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Screw fixation is an established method for anterior cruciate ligament (ACL) reconstruction, although with a high rate of implant-related complications. An allograft system for implant fixation in ACL reconstruction, the Shark Screw ACL (surgebright GmbH) could overcome some of the shortcomings of bioabsorbable screws, such as foreign body reaction, need for implant removal and imaging artefacts. However, it needs to provide sufficient mechanical stability. Therefore, the aim of this study was to investigate the biomechanical stability, especially graft slippage, of the novel allograft system versus a conventional bioabsorbable interference screw (BioComposite Interference Screw; Arthrex Inc.) for tibial implant fixation in ACL reconstruction. Twenty-four paired human proximal tibiae (3 female, 9 male, 72.7 ± 5.6 years) underwent ACL reconstruction. The quadrupled semitendinosus and gracilis tendon graft were fixed in one specimen of each pair using the allograft fixation system Shak Screw ACL and the contralateral one using an interference screw. All specimens were cyclically loaded at 1 Hz with peak load levels monotonically increased from 50 N at a rate of 0.1 N/cycle until catastrophic failure. Relative movements of the graft versus the tibia were captured with a stereographic optical motion tracking system (Aramis SRX; GOM GmbH). The two fixation methods did not demonstrate any statistical difference in ultimate load at graft slippage (p = 0.24) or estimated survival at slippage (p = 0.06). Both, the ultimate load and estimated survival until failure were higher in the interference screw (p = 0.04, and p = 0.018, respectively). Graft displacement at ultimate load reached values of up to 7.2 mm (interference screw) and 11.3 mm (Shark Screw ACL). The allograft screw for implant fixation in ACL reconstruction showed similar behavior in terms of graft slippage compared to the conventional metal interference screw but underperformed in terms of ultimate load. However, the ultimate load may not be considered a direct indicator of clinical failure

The management of comminuted metaphyseal fractures is a technical challenge and satisfactory outcomes of such fixations often remain elusive. The small articular fragments and bone loss often make it difficult for standard fixation implants for proper fixation. We developed a novel technique to achieve anatomical reduction in multiple cases of comminuted metaphyseal fractures at different sites by employing the cantilever mechanism with the help of multiple thin Kirschner wires augmented by standard fixation implants. We performed a retrospective study of 10 patients with different metaphyseal fractures complicated by comminution and loss of bone stock. All patients were treated with the help of cantilever mechanism using multiple Kirschner wires augmented by compression plates. All the patients were operated by the same surgeon between November 2020 to March 2021 and followed up till March 2023. Surgical outcomes were evaluated according to the clinical and radiological criteria. A total of 10 patients were included in the study. Since we only included patients with highly unstable and comminuted fractures which were difficult to fix with traditional methods, the number of patients in the study were less. All 10 patients showed satisfactory clinical and radiological union at the end of the study with good range of motion. One of the patient in the study had post-operative wound complication which was managed conservatively with regular dressings and oral antibiotics. Comminuted metaphyseal fractures might differ in pattern and presentation with every patient and there can be no standard treatment for all. The cantilever technique of fracture fixation is based on the principle of cantilever mechanism used in bridges and helps achieve good anatomical reduction and fixation. It provides a decent alternative when standard modes of fixation don't give desired result owing to comminuted nature of fractures and deficiency of bone stock

Reorientating pelvic osteotomies are performed to improve femoral head coverage and secondary degenerative arthritis. A rectangular triple pelvic innominate osteotomy (3PIO) is performed in symptomatic cases. However, deciding optimal screw fixation type to avoid complications is questionable. Therefore, this study aimed to investigate the biomechanical behavior of two different acetabular screw configurations used for rectangular 3PIO osteosynthesis. It was hypothesized that bi-directional screw fixation would be biomechanically superior to mono-axial screw fixation technique. A rectangular 3PIO was performed in twelve right-side artificial Hemi-pelvises. Group 1 (G1) had two axial and one transversal screw in a bi-directional orientation. Group 2 (G2) had three screws in the axial direction through the iliac crest. Acetabular fragment was reoriented to 10.5° inclination in coronal plane, and 10.0° increased anteversion along axial plane. Specimens were biomechanically tested until failure under progressively increasing cyclic loading at 2Hz, starting at 50N peak compression, increasing 0.05N/cycle. Stiffness was calculated from machine data. Acetabular anteversion, inclination and medialization were evaluated from motion tracking data from 250-2500 at 250 cycle increments. Failure cycles and load were evaluated for 5° change in anteversion. Stiffness was higher in G1 (56.46±19.45N/mm) versus G2 (39.02±10.93N/mm) but not significantly, p=0.31. Acetabular fragment anteversion, inclination and medialization increased significantly each group (p≤0.02) and remained non-significantly different between the groups (p≥0.69). Cycles to failure and failure load were not significantly different between G1 (4406±882, 270.30±44.10N) and G2 (5059±682, 302.95±34.10N), p=0.78. From a biomechanical perspective, the present study demonstrates that a bi-directional screw orientation does not necessarily advantageous versus mono-axial alignment when the latter has all three screws evenly distributed over the osteotomy geometry. Moreover, the 3PIO fixation is susceptible to changes in anteversion, inclination and medialization of the acetabular fragment until the bone is healed. Therefore, cautious rehabilitation with partial weight-bearing is recommended

First-time revision acetabular components have a 36% re-revision rate at 10 years in Australia, with subsequent revisions known to have even worse results. Acetabular component migration >1mm at two years following revision THA is a surrogate for long term loosening. This study aimed to measure the migration of porous tantalum components used at revision surgery and investigate the effect of achieving press-fit and/or three-point fixation within acetabular bone. Between May 2011 and March 2018, 55 patients (56 hips; 30 female, 25 male) underwent acetabular revision THR with a porous tantalum component, with a post-operative CT scan to assess implant to host bone contact achieved and Radiostereometric Analysis (RSA) examinations on day 2, 3 months, 1 and 2 years. A porous tantalum component was used because the defects treated (Paprosky IIa:IIb:IIc:IIIa:IIIb; 2:6:8:22:18; 13 with pelvic discontinuity) were either deemed too large or in a position preventing screw fixation of an implant with low coefficient of friction. Press-fit and three-point fixation of the implant was assessed intra-operatively and on postoperative imaging. Three-point acetabular fixation was achieved in 51 hips (92%), 34 (62%) of which were press-fit. The mean implant to host bone contact achieved was 36% (range 9-71%). The majority (52/56, 93%) of components demonstrated acceptable early stability. Four components migrated >1mm proximally at two years (1.1, 3.2, 3.6 and 16.4mm). Three of these were in hips with Paprosky IIIB defects, including 2 with pelvic discontinuity. Neither press-fit nor three-point fixation was achieved for these three components and the cup to host bone contact achieved was low (30, 32 and 59%). The majority of porous tantalum components had acceptable stability at two years following revision surgery despite treating large acetabular defects and poor bone quality. Components without press-fit or three-point fixation were associated with unacceptable amounts of early migration

Background. Surgical management of calcaneus fractures is demanding and has a high risk of wound complications. Traditionally these fractures are managed with splinting until swelling has subsided. We describe a novel protocol for the management of displaced intra-articular calcaneus fractures utilising a temporizing external fixator and staged conversion to plate fixation through a sinus tarsi approach. The goal of this technique is to allow for earlier treatment with open reduction and internal fixation, minimise the amount of manipulation required at the time of definitive fixation and reduce the wound complication rate seen with the extensile approach. Methods. The records of patients with displaced calcaneus fractures from 2010–2014 were retrospectively reviewed. A total of 10 patients with 12 calcaneus fractures were treated with this protocol. All patients underwent ankle-spanning medial external fixation within 48 hours of injury. Patients underwent conversion to open plate fixation through a sinus tarsi approach when skin turgor had returned to normal. Time to surgery, infection rate, wound complications, radiographic alignment, and time to radiographic union were recorded. Results. The average Bohler's angle improved from 13.2 (range −2 to 34) degrees preoperatively to 34.3 (range 26 to 42) degrees postoperatively. The average time from external fixation to conversion to internal fixation was 4.8 (range 3 to 7) days. There were no immediate post-surgical complications. The average time to weight bearing was 8.5 weeks. The average time to radiographic union was 9.5 (range 8 to 12) weeks. There were no infections or wound complications at the time of last follow-up. Conclusions. Early temporizing external fixation for the acute management of displaced calcaneus fractures is a safe and effective method to reduce and stabilise the foot and may decrease the time to definitive fixation. In our series there were no complications related to the use of the external fixator. Level of Evidence. IV Retrospective case series

Total hip arthroplasty (THA) outcome in patients with osteonecrosis of the femoral head ONFH) are excellent, however, there is controversy when compared with those in patients with osteoarthritis (OA). Reduced mineralization capacity of osteoblasts of the proximal femur in patients with ONFH could affect implant fixation. We asked if THA fixation in patients with ONFH is worse than in those with OA. We carried out a prospective comparative case (OA)-control (ONFH) study of patients undergoing THA at our hospital between 2017 and 2019. The minimum follow-up was 2 years. Inclusion criteria were patients with uncemented THA, younger than 70 years old, a Dorr femoral type C and idiopathic ONFH. We compared the clinical (Merlé D'Aubigné-Postel score) and radiological results related with implant positioning and fixation. Engh criteria and subsidence were assessed at the immediate postoperative, 12 weeks, 6 months, 12 months and yearly. Osteoblastic activity was determined by mineralization assay on primary cultures of osteoblasts isolated from trabecular bone samples collected from the intertrochanteric area obtained during surgery. Group 1 (ONFH) included 18 patients and group 2 (OA), 22. Average age was 55.9 years old in group 1 and 61.3 in group 2. (p=0.08). There were no differences related with sex, Dorr femoral type or femoral filling. The mean clinical outcome score was 17.1 in group 1 and 16.5 in group 2 (p=0.03). There were no cases of dislocation, infection, or revision surgery in this series. There were 5 cases (28%) of femoral stem subsidence greater than 3mm within 6 first months in group 1 and 1 case (4.5%) in group 2 (p=0.05). Although there were no significant differences related to clinical results, bone fixation was slower, and a greater subsidence was observed in patients with ONFH. Greater femoral stem subsidence was associated with a lower capacity for mineral nodule formation in cultured osteoblasts. The surgical technique could influence THA outcome in patients with reduced mineralization capacity of osteoblasts

The objective of this study was to investigate how a new customizable light-curable osteosynthesis method (AdFix) compared to traditional metal hardware when loaded in torsion in an ovine phalanx model. Twenty-one ovine proximal phalanges were given a 3mm transverse osteotomy and four 1.5mm cortex screws were inserted bicortically on either side of the gap. The light-curable polymer composite was then applied using the method developed by Hutchinson [1] to create osteosyntheses in two groups, having either a narrow (6mm, N=9) or a wide (10mm, N=9) fixation patch. A final group (N=3) was fixated with conventional metal plates. The constructs were loaded in torsion at a rate of 6°/second until failure or 45° of rotation was reached. Torque and angular displacement were measured, torsional stiffness was calculated as the slope of the Torque-Displacement curve, and maximum torque was queried for each specimen. The torsional stiffnesses of the narrow, wide, and metal plate constructs were 39.1 ± 6.2, 54.4 ± 6.3, and 16.2 ± 3.0 Nmm/° respectively. All groups were statistically different from each other (p<0.001). The maximum torques of the narrow, wide, and metal plate constructs were 424 ± 72, 600 ± 120, and 579 ± 20 Nmm respectively. The narrow constructs were statistically different from the other two (p<0.05), while the wide and metal constructs were not statistically different from each other (p=0.76). This work demonstrated that the torsional performance of the novel solution is comparable to metal fixators. As a measure of the functional range, the torsional stiffness in the AdhFix exceeded that of the metal plate. Furthermore, the wide patches were able to sustain a similar maximum toque as the metal plates. These results suggest AdhFix to be a viable, customizable alternative to metal implants for fracture fixation in the hand

Introduction. When designing a new osteosynthesis device, the biomechanical competence must be evaluated with respect to the acting loads. In a previous study, the loads on the proximal phalanx during rehabilitation exercises were calculated. This study aimed to assess the safety of a novel customizable osteosynthesis device compared to those loads to determine when failure would occur. Method. Forty proximal phalanges were dissected from skeletally mature female sheep and divided into four testing groups. A custom 3D printed cutting and drilling guide was used to create a reduced osteotomy and pilot holes to insert four 1.5 mm cortical screws. A novel light-curable polymer composite was used to fixate the bones with an in situ fixation patch. The constructs were tested in cyclic four-point bending in a bioreactor with ringer solution at 37°C with a valley load of 2 N. Four groups (N = 10) had increasing peak loads based on varying safety factors relative to the physiological loading (G1:100x, G2:150x, G3:175x, G4:250x). Each specimen was tested for 12,600 cycles (6 weeks of rehabilitation) or until failure occurred. After the test the thickness of the patch was measured with digital calipers and data analysis was performed in Python and R. Result. All samples survived in G1, and all failed in G4. G2 and G3 had 1 and 8 failures, respectively. There was no significant difference in patch thickness in all survivor samples against failures (p = 0.131), however, there was a significant difference in the displacement amplitude in the final cycle (0.072 mm vs. 0.15 mm; p < 0.001). Conclusion. This study found the survival and failure limits of a novel osteosynthesis device as a function of physiological loading. These results indicate that such fixations could withstand 100x the loading for typical non-weightbearing rehabilitation. Further studies are needed to confirm the safety for other conditions

This study aims to compare the outcomes of Volar locking plating (VLP) versus percutaneous Kirschner wires (K-wire) fixation for surgical management of distal radius fractures. We systematically searched multiple databases, including MEDLINE for randomized controlled trials (RCTs) comparing outcomes of VLP fixation and K-wire for treatment of distal radius fracture in adults. The methodological quality of each study was assessed by the Cochrane Risk of Bias tool. Patient-reported outcomes, functional outcomes, and complications at 1 year follow up were evaluated. Meta-analysis was performed using random-effects models and results presented as risk ratios (RRs) or mean differences (MDs) with 95% confidence interval (CI). 13 RCTs with 1336 participants met the inclusion criteria. Disabilities of the Arm, Shoulder and Hand (DASH) scores were significantly better for VLP fixation (MD= 2.15; 95% CI, 0.56-3.74; P = 0.01; I2=23%). No significant difference between the two procedures for grip strength measured in kilograms (MD= −3.84; 95% CI,-8.42-0.74; P = 0.10; I2=52%) and Patient-Rated Wrist Evaluation (PRWE) scores (MD= −0.06; 95% CI,-0.87-0.75; P = 0.89; I2=0%). K-wire treatment yielded significantly improved extension (MD= −4.30; P=0.04) but with no differences in flexion, pronation, supination, and radial deviation (P >0.05). The risk of complications and rate of reoperation were similar for the two procedures (P >0.05). This meta-analysis suggests that VLP fixation improves DASH score at 12 months follow up, however, the difference is small and unlikely to be clinically important. Existing literature does not provide sufficient evidence to demonstrate the superiority of either VLP or K-wire treatment in terms of patient-reported outcomes, functional outcomes, and complications

Ankle fractures are among the most common types of fractures. If surgery is not performed within 12 to 24 hours, ankle swelling is likely to develop and delay the operative fixation. This leads to patients staying longer in the ward waiting and increased hospital occupancy. This prolonged stay has significant financial implication as well as it is frustrating for both patients and health care professionals. The aim was to formulate a pathway for the ankle fracture patients coming to the emergency department, outpatients and planned for operative intervention. To identify whether pre-operative hospital admissions of stable ankle fracture patients are reduced with the implementation of the pathway. We formulated an ankle fracture fixation pathway, which was approved for use in December 2020. A retrospective analysis of 6 months hospital admissions of ankle fracture patients in the period between January to June 2020. The duration from admission to the actual surgery was collected to review if some admissions could have been avoided and patients brought directly on the surgery day. A total of 23 patients were included. Mean age was 60.5 years and SD was 17years. 94% of patients were females. 10 patients were appropriately discharged.7 Patients were appropriately admitted. 6 Patients were unnecessarily admitted. These 6 patients were admitted on presentation to ED. Retrospective analysis of this audit showed that this cohort of patients met the safe discharge criteria and could have been discharged. Duration of unnecessary stay ranged from 1 to 11 days (21 days in total). Total saving could have been £6300. Standards were met in 74% of cases. Preoperative hospital admission could be reduced with the proposed pathway. It is a valuable tool to be used and should be implemented to reduce unnecessary hospital admissions

Lateral lumbar interbody fusion (LLIF) has biomechanical advantages due to the preservation of ligamentous structures (ALL/PLL), and optimal cage height afforded by the strength of the apophyseal ring. We compare the biomechanical motion stability of multiple levels LLIF (4 segments) utilising PEEK interbody 26mm cages to stand-alone cage placement and with supplemental posterior fixation with pedicle screw and rods. Six lumbar human cadaver specimens were stripped of the paraspinal musculature while preserving the discs, facet joints, and osteoligamentous structures and potted. Specimens were tested under 5 conditions: intact, posterior bilateral fixation (L1-L5) only, LLIF-only, LLIF with unilateral fixation and LLIF with bilateral fixation. Non-destructive testing was performed on a universal testing machine (MTS Systems Corp) to produce flexion-extension, lateral-bending, and axial rotation using customized jigs and a pulley system to define a non-constraining load follower. Three-dimensional spine motion was recorded using a motion device (Optotrak). Results are reported for the L3-L4 motion segment within the construct to allow comparison with previously published works of shorter constructs (1-2 segments). In all conditions, there was an observed decrease in ROM from intact in flexion/extension (31%-89% decrease), lateral bending (19%-78%), and axial rotation (37%-60%). At flexion/extension, the decreases were statistically significant (p<0.007) except for stand-alone LLIF. LLIF+unilateral had similar decreases in all planes as the LLIF+bilateral condition. The observed ROM within the 4-level construct was similar to previously reported results in 1-2 levels for stand-alone LLIF and LLIF+bilateral. Surgeons may be concerned about the biomechanical stability of an approach utilizing stand-alone multilevel LLIF. Our results show that 4-level multilevel LLIF utilizing 26 mm cages demonstrated ROM comparable to short-segment LLIF. Stand-alone LLIF showed a decrease in ROM from the intact condition. The addition of posterior supplemental fixation resulted in an additional decrease in ROM. The results suggest that unilateral posterior fixation may be sufficient

Introduction. This study aims to investigate the relationship between ulnar fixation and postoperative satisfaction among patients with distal radius fractures accompanied by ulna styloid fractures, with a particular focus on how sociodemographic factors influence outcomes. Method. A retrospective cohort study was conducted involving 120 patients aged 26-53 who underwent surgical treatment for distal radius fractures with concomitant ulna styloid fractures between January 2018 and December 2022. Patients were divided into two groups based on whether ulnar fixation was performed. Sociodemographic data, including age, gender, socioeconomic status, education level, and occupation, were collected. All patients underwent similar physical therapy protocols in the postoperative period, and no complications were observed in any patient. Postoperative satisfaction was assessed using the Patient-Rated Wrist Evaluation (PRWE) and the Disabilities of the Arm, Shoulder, and Hand (DASH) scores at 6 and 12 months post-surgery. Statistical analysis was conducted to evaluate the influence of ulnar fixation and sociodemographic factors on patient satisfaction. Result. Patients who underwent ulnar fixation (n=60) reported significantly higher satisfaction levels compared to those who did not (n=60), as evidenced by lower PRWE and DASH scores (p < 0.05). Age, gender, and socioeconomic status were significant predictors of postoperative satisfaction. Younger patients, females, and those with higher socioeconomic status exhibited greater improvements in functional outcomes and satisfaction. However, education level and occupation did not significantly influence satisfaction scores. Conclusion. Ulnar fixation in the surgical treatment of distal radius fractures accompanied by ulna styloid fractures is associated with improved postoperative satisfaction. Sociodemographic factors, particularly age, gender, and socioeconomic status, play a crucial role in patient-reported outcomes. Tailoring postoperative care to address these sociodemographic differences may enhance overall patient satisfaction and recovery

Introduction. Glenoid loosening, still a main complication for shoulder arthroplasty, was suggested to be related implant design, surgical aspects, and also bone quality. However, typical studies of fixation do not account for heterogeneity in bone morphology and density which were suggested to affect fixation failure. In this study, a combination of cyclic rocking horse tests on cadaver specimens and microCT-based finite element (microFE) analysis of specimens of a wide range of bone density were used to evaluate the effects of periprosthetic bone quality on the risks of loosening of anatomical keeled or pegged glenoid implants. Methods. Six pairs of cadaveric scapulae, scanned with a quantitative computer tomography (QCT) scanner to calculate bone mineral density (BMD), were implanted with either cemented anatomical pegged or keeled glenoid components and tested under constant glenohumeral load while a humeral head component was moved cyclically in the inferior and superior directions. Edge displacements were measured after 1000, 4000 and 23000 test cycles, and tested for statistical differences with regards to changes or implant design. Relationships were established between edge displacements and QCT-based BMD below the implant. Four other specimens were scanned with high-resolution peripheral QCT (82µm) and implanted with the same 2 implants to generate virtual models. These were loaded with constant glenohumeral force, varying glenohumeral conformity and superior or inferior load shifts while internal stresses at the cement-bone and implant-cement interfaces were calculated and related to apparent bone density in the periprosthetic zone. Results. Mean displacements at the inferior and superior edges showed no statistical difference between keeled and pegged designs (p>0.05). Compression and distraction were however statistically different from the initial reference measurement at even 1000 and 4000 cycles for both implant designs (p<0.05). For both implant designs, superior and inferior distractions were generally highest at each measurement time in specimens where BMD below the lifting edge was lower, showing a trend of increased distraction with decreased BMD. Moreover, the microFE models predicted higher bone and cement stresses for specimens of lower apparent bone density. Finally, highest peak stresses were located at the cement-bone interface, which seemed the weaker part of the fixation. Discussion. With this combined experimental and numerical study, it was shown that implant distraction and stresses in the cement layer are greater in glenoids of lower bone density for both implant designs. This indicates that fixation failure will most likely occur in bone of lower density, and that fixation design itself may play a secondary role. These results have important impact for understanding the mechanisms of glenoid component failure, a common complication of total shoulder arthroplasty

Introduction. Unplanned reoperations (UROs) following corrective surgery for adult spinal deformity (ASD) present significant challenges for both patients and surgeons. Understanding the specific UROs types is crucial for improving patient outcomes and refining surgical strategies in ASD correction. Method. This retrospective analysis utilized data from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database spanning from 2017 to 2021. Patient information was extracted using specific CPT codes related to posterior pedicle fixation. Result. In a cohort of 1088 patients undergoing posterior spinal deformity corrections, we examined various preoperative factors to discern their correlation with reoperation prevalence. Our analysis revealed no statistically significant differences in reoperation prevalence concerning gender (male: 4.0%, p=0.131) or ethnicity (Hispanic: 4.2%, p=0.192). Similarly, no notable associations were identified for diabetes mellitus, smoking status, dyspnea, history of severe COPD, hypertension, ASA classification, or functional health status before surgery, with reoperation prevalences ranging from 3.2% to 8.8% and p-values spanning from 0.146 to 0.744. Overall, the reoperation prevalence within the entire cohort stood at 5.2% (55 cases). In terms of the types of reoperations investigated, spinal-related procedures emerged as the most prevalent, accounting for 43.7% (24 cases), followed closely by wound site revisions at 23.6% (13 cases). Additionally, gastrointestinal-related procedures and various other miscellaneous interventions, such as uroscopy, demonstrated reoperation prevalences of 7.2% (4 cases) and 25.5% (14 cases), respectively. Conclusion. our findings highlight the diverse spectrum of reoperation procedures encountered following posterior spinal deformity corrections, with wound site revisions and spinal-related interventions being the most prevalent categories. These results emphasize the complexity of managing UROs in spinal surgery and the need for tailored approaches and infection/incision protocols to address the specific challenges associated with each type of reoperation

The use of intraoperative navigation and robotic surgery for minimally invasive lumbar fusion has been increasing over the past decade. The aim of this study is to evaluate postoperative clinical outcomes, intraoperative parameters, and accuracy of pedicle screw insertion guided by intraoperative navigation in patients undergoing lumbar interbody fusion for spondylolisthesis. Patients who underwent posterior lumbar fusion interbody using intraoperative 3D navigation since December 2021 were included. Visual Analogue Scale (VAS), Oswestry Disability Index (ODI), and Short Form Health Survey-36 (SF-36) were assessed preoperatively and postoperatively at 1, 3, and 6 months. Screw placement accuracy, measured by Gertzbein and Robbins classification, and facet joint infringement, measured by Yson classification, were assessed by intraoperative Cone Beam CT scans performed at the end of instrumentation. Finally, operation time, intraoperative blood loss, hospital stay, and screw insertion time were evaluated. This study involved 50 patients with a mean age of 63.7 years. VAS decreased from 65.8±23 to 20±22 (p<.01). ODI decreased from 35.4%±15 to 11.8%±14 (p<.01). An increase of SF-36 from 51.5±14 to 76±13 (p<.01) was demonstrated. The accuracy of “perfect” and “clinically acceptable” pedicle screw fixation was 89.5% and 98.4%, respectively. Regarding facet violation, 96.8% of the screws were at grade 0. Finally, the average screw insertion time was 4.3±2 min, hospital stay was 4.2±0.8 days, operation time was 205±53 min, and blood loss was 169±107 ml. Finally, a statistically significant correlation of operation time with hospital stay, blood loss and placement time per screw was found. We demonstrated excellent results for accuracy of pedicle screw fixation and violation of facet joints. VAS, ODI and SF-36 showed statistically significant improvements from the control at one month after surgery. Navigation with intraoperative 3D images represents an effective system to improve operative performance in the surgical treatment of spondylolisthesis

Determine the infection risk of nonoperative versus operative repair of extraperitoneal bladder ruptures in patients with pelvic ring injuries. Pelvic ring injuries with extraperitoneal bladder ruptures were identified from a prospective trauma registry at two level 1 trauma centers from 2014 to 2020. Patients, injuries, treatments, and complications were reviewed. Using Fisher's exact test with significance at P value < 0.05, associations between injury treatment and outcomes were determined. Of the 1127 patients with pelvic ring injuries, 68 (6%) had a concomitant extraperitoneal bladder rupture. All patients received IV antibiotics for an average of 2.5 days. A suprapubic catheter was placed in 4 patients. Bladder repairs were performed in 55 (81%) patients, 28 of those simultaneous with ORIF anterior pelvic ring. The other 27 bladder repair patients underwent initial ex-lap with bladder repair and on average had pelvic fixation 2.2 days later. Nonoperative management of bladder rupture with prolonged Foley catheterization was used in 13 patients. Improved fracture reduction was noted in the ORIF cohort compared to the closed reduction external fixation cohort (P = 0.04). There were 5 (7%) deep infections. Deep infection was associated with nonoperative management of bladder rupture (P = 0.003) and use of a suprapubic catheter (P = 0.02). Not repairing the bladder increased odds of infection 17-fold compared to repair (OR 16.9, 95% CI 1.75 – 164, P = 0.01). Operative repair of extraperitoneal bladder ruptures substantially decreases risk of infection in patients with pelvic ring injuries. ORIF of anterior pelvic ring does not increase risk of infection and results in better reductions compared to closed reduction. Suprapubic catheters should be avoided if possible due to increased infection risk later. Treatment algorithms for pelvic ring injuries with extraperitoneal bladder ruptures should recommend early bladder repair and emphasize anterior pelvic ORIF

Introduction and Objective. Postoperative management regimes vary following open reduction and internal fixation of unstable ankle fractures. There is an evolving understanding that poorer outcomes could be associated with non-weight bearing protocols and immobilisation. Traditional non-weight bearing cast immobilisation may prevent loss of fixation, and this practice continues in many centres. The aim of this systematic review and meta-analysis is to compare the complication rate and functional outcomes of early weight-bearing (EWB) versus late weight-bearing (LWB) following open reduction and internal fixation of ankle fractures. Materials and Methods. We performed a systematic review with a meta-analysis of controlled trials and comparative cohort studies. MEDLINE (via PubMed), Embase and the Cochrane Library electronic databases were searched inclusive of all date up to the search time. We included all studies that investigated the effect of weight-bearing following adults ankle fracture fixation by any means. All ankle fracture types, including isolated lateral malleolus fractures, isolated medial malleolus fractures, bi-malleolar fractures, tri-malleolar fractures and Syndesmosis injuries, were included. All weight-bearing protocols were considered in this review, i.e. immediate weight-bearing (IMW) within 24 hours of surgery, early weight-bearing (EWB) within three weeks of surgery, non-weight-bearing for 4 to 6 weeks from the surgery date (or late weight-bearing LWB). Studies that investigated mobilisation but not weight-bearing, non-English language publications and tibial Plafond fractures were excluded from this systematic review. We assessed the risk of bias using ROB 2 tools for randomised controlled trials and ROBINS-1 for cohort studies. Data extraction was performed using Covidence online software and meta-analysis by using RevMan 5.3. Results. After full-text review, fourteen studies (871 patients with a mean age ranged from 35 to 57 years) were deemed eligible for this systematic review; ten randomised controlled trials and four comparative cohort studies. Most of the included studies were rated as having some concern with regard to the risk of bias. There is no important difference in the infection rate between protected EWB and LWB groups (696 patients in 12 studies). The risk ratio (RR) is 1.30, [95% CI 0.74 to 2.30], I. 2. = 0%, P = 0.36). Other complications were rare. The Olerud-Molander Ankle Score (OMAS) was the widely used patient-reported outcome measure after ankle fracture fixation among the studies. The result of the six weeks OMAS analysis (three RCTs) was markedly in favour of the early weight-bearing group (MD = 10.08 [95% CI 5.13 to 15.02], I. 2. = 0%P = <0.0001). Conclusions. The risk of postoperative complications is an essential factor when considering EWB. We found that the overall incidence of surgical site infection was 6%. When comparing the two groups, the incidence was 5.2% and 6.8% for the LWB and EWB groups. This difference is not clinically important. On the other hand, significantly better early functional outcome scores were detected in the EWB group. These results are not without limitations. Protected early weight-bearing following open reduction and internal fixation of ankle fractures is potentially safe and improve short-term functional outcome. Further good-quality randomised controlled trials would be needed before we could draw a more precise conclusion

Helical plates are preferably used for proximal humeral shaft fracture fixation and potentially avoid radial nerve irritation as compared to straight plates. Aims:(1) to investigate the safety of applying different long plate designs (straight, 45°-, 90°-helical and ALPS) in MIPO-technique to the humerus. (2) to assess and compare their distances to adjacent anatomical structures at risk. MIPO was performed in 16 human cadaveric humeri using either a straight plate (group1), a 45°-helical (group2), a 90°-helical (group3) or an ALPS (group4). Using CT-angiography, distances between brachial arteries and plates were evaluated. Following, all specimens were dissected, and distances to the axillary, radial and musculocutaneous nerve were evaluated. None of the specimens demonstrated injuries of the anatomical structures at risk after MIPO with all investigated plate designs. Closest overall distance (mm(range)) between each plate and the radial nerve was 1(1-3) in group1, 7(2-11) in group2, 14(7-25) in group3 and 6(3-8) in group4. It was significantly longer in group3 and significantly shorter in group1 as compared to all other groups, p<0.001. Closest overall distance (mm(range)) between each plate and the musculocutaneous nerve was 16(8-28) in group1, 11(7-18) in group2, 3(2-4) in group3 and 6(3-8) in group4. It was significantly longer in group1 and significantly shorter in group3 as compared to all other groups, p<0.001. Closest overall distance (mm(range)) between each plate and the brachial artery was 21(18-23) in group1, 7(6-7) in group2, 4(3-5) in group3 and 7(6-7) in group4. It was significantly longer in group1 and significantly shorter in group3 as compared to all other groups, p<0.021. MIPO with 45°- and 90°-helical plates as well as ALPS is safely feasible and showed a significant greater distance to the radial nerve compared to straight plates. However, distances remain low, and attention must be paid to the musculocutaneous nerve and the brachial artery when MIPO is used with ALPS, 45°- and 90°-helical implants. Anterior parts of the deltoid insertion will be detached using 90°-helical and ALPS implants in MIPO-technique