Search Results (600)

Surgical fixation techniques for bone fracture healing are well established and effective; however, opportunities remain to improve both functional outcomes and the patient experience. The Biofiligree^® concept integrates medicine, engineering, and design by reimagining conventional osteosynthesis plates as both therapeutic and aesthetic devices. Inspired by traditional Portuguese filigree, these plates allow patient participation through personalized geometries, patterns, or engravings and may later be transformed into wearable jewellery after removal, preserving them as symbolic artefacts of recovery. This study introduces and biomechanically evaluates a novel calcaneal fixation plate incorporating the biofiligree geometry concept. A biofiligree plate was designed for calcaneus fracture fixation and manufactured in stainless steel 306L. Experimental testing was conducted on synthetic composite calcaneus bone models to simulate anatomical conditions and compare the new design with a standard commercial plate. The biofiligree plate, 2 mm thick, was fixed using five screws and two percutaneous screws positioned at 45° to compress the fracture line. Results demonstrated comparable biomechanical performance between both systems, with similar strain distributions and fracture stabilization. The biofiligree plate showed stresses around 430 MPa and fracture displacement below 0.7 mm. Fixation stiffness values were 1445 N/mm for intact calcaneus, 1065 N/mm for the commercial plate, and 725 N/mm for the biofiligree plate, indicating adequate support for bone healing. Full article

Articular fractures require precise anatomical reduction and rigid fixation to heal appropriately. In veterinary cases that involve fracturing of the lateral humeral condyle, cortical bone screws inserted in lag fashion with Kirschner wire are the preferred method for surgical fixation. However, relatively high complication rates associated with cortical lag screws (CLSs) highlights the need to investigate alternate screw designs. Variable-pitch headless compression screws (VPHCSs) are unique as they advance beneath the cortical surface. Although the use of VPHCSs are widely utilised in human orthopaedics, the current use in veterinary orthopaedics is limited. This study aimed to evaluate the peak interfragmentary force (PIF) and area of compression (AOC) generated by a 3.5 mm self-tapping cortical screw placed in lag fashion and a 3.5 mm VPHCS inserted to four depths. PIF and AOC were measured using a pressure-sensitive film placed between two blocks of polyurethane foam (0.24 g/cm³), simulating a transverse fracture. CLSs were inserted by hand into predrilled 2.5 mm pilot holes. PIF and AOC were measured at full insertion. VPHCSs were placed into predrilled 2.5 mm pilot holes, followed by a 3.5 mm tapered countersink. The screw was inserted until the head was level with the surface. PIF and AOC were measured between the two blocks. The screw was continued until the head was at a depth of 2, 5, and 9 mm below the surface, and the PIF and AOC were measured again at each stage. There was no detectable difference in PIF and AOC between CLSs and VPHCSs countersunk to −2 mm (PIF–CLS: Mean = 12.886, SD = 2.370; 2 mm: Mean = 17.301, SD = 8.858, p = 0.319; AOC–CLS: Mean = 0.936, SD = 0.291; 2 mm: Mean = 0.925, SD = 0.447, p = 0.872). VPHCSs countersunk to −5 mm and −9 mm produced significantly greater PIF compared to CLSs (5 mm: Mean = 16.086, SD = 6.799, p = 0.002; 9 mm: Mean = 34.987, SD = 4.015, p < 0.001). VPHCSs countersunk to −5 and −9 mm produced significantly greater PIF and AOC compared to CLSs in this model. Further investigation is required to produce recommendations for clinical use. Full article

Management of unstable upper lumbar fractures with corpectomy and posterior fixation is technically demanding, and conventional workflows may require intraoperative repositioning, increasing operative complexity. Lateral mini-open upper lumbar corpectomy (LMULC) paired with robotic-assisted (RA) posterior percutaneous pedicle screw fixation (PPPSF) can be performed in a single position to facilitate ventral spinal decompression and stabilization in the anatomically constrained upper lumbar spine. In this study, we describe the operative technique and report four illustrative cases of unstable L1 or L2 fractures treated with single-position LMULC, RA-PPPSF, and short-segment fusion. Clinical, radiological, intraoperative variables and postoperative outcomes were evaluated. The mean age was 52.3 ± 17.7 years. The median operation time was 314 min (range 268–361 min); the median estimated blood loss (EBL) was 225 mL (range 100–400 mL). The median preoperative kyphosis was 10.15° (range 8.4–14.6°), the median postoperative kyphosis measured 6.65° (range 1.7–10.8°) and the median correction achieved was 3.5° (range −2.4–12.9°). The median visual analog scale (VAS) pain score reduced from 7 (range 7–9) preoperatively to 4.5 (range 2–6) postoperatively at discharge. At a median follow-up of 12 months (range 6–15 months), all patients had uncomplicated recoveries, demonstrated solid fusion on imaging, and reported favorable MacNab outcomes. Single-position LMULC with RA-PPPSF was technically feasible in this preliminary illustrative series and resulted in favorable clinical and radiographic outcomes. However, further studies in larger cohorts are warranted to help confirm these findings and better define the potential advantages and limitations of this technique. Full article

Background: The Lapidus procedure has become a cornerstone in the surgical management of hallux valgus, especially in cases with associated tarsometatarsal instability. This study investigated and compared the radiographic outcomes of three distinct Lapidus constructs, aiming to provide valuable insights into the optimal fusion configurations for achieving long-term stability improvement and maintaining the intermetatarsal angle (IMA) postoperatively. Methods: In this retrospective study, the objective was to assess and compare the outcomes of three different fusion constructs used in the Lapidus procedure: group 1, transverse screw fixation; group 2, metatarsal cuneiform screw fixation; and group 3, combined transverse and metatarsal cuneiform screw fixation. The study encompassed 32 feet: 11 in group 1, 8 in group 2, and 13 in group 3. The primary focus was to evaluate postoperative stability through radiographic imaging complemented by clinical assessments and an examination of complications. Statistical analyses were used to compare outcomes across the three fixation groups immediately, 3 months, 6 months, and 1 year postoperatively. Results: Radiographic assessments demonstrated successful fusion, and patients reported improvements in pain and function and overall satisfaction with the procedure. Complication rates were within an acceptable range. The IMA in all three groups exhibited a significant reduction postoperatively compared with preoperative measurements. Group 3 demonstrated a notably stronger initial reduction in the IMA compared with groups 1 and 2, and they maintained a statistically significantly more stable IMA value and exhibited a lower recurrence rate compared with the other two groups 1 year postoperatively. Conclusions: These findings endorse the use of Lapidus fusion with these three constructs, particularly with combined transverse and metatarsal cuneiform screw fixation, as a dependable and efficacious surgical approach in addressing hallux valgus with concomitant tarsometatarsal instability. Full article

Background: Syndesmotic screw breakage is a well-recognized mechanical complication following ankle fracture fixation. Although several studies have investigated patient-related and technical factors associated with screw breakage, the temporal pattern of screw failure and implant survival remains less clearly defined. Therefore, this study aimed to evaluate one-year syndesmotic screw survival using time-to-event analysis and to identify factors associated with screw breakage. Materials and Methods: A total of 132 patients with unstable AO-Weber 44-B/C ankle fractures treated with syndesmotic screw fixation were retrospectively analyzed. Patients were followed for a minimum of 12 months or until screw breakage occurred. Screw survival was evaluated using Kaplan–Meier analysis and Cox proportional hazards regression was performed to identify factors associated with screw breakage. Demographic variables, fracture type, and screw-related parameters were analyzed. Receiver operating characteristic (ROC) analysis was used to assess the discriminative ability of age. Results: Screw breakage occurred in 31 patients (23.5%) during follow-up. Kaplan–Meier analysis demonstrated significantly lower screw survival in Weber C fractures compared with Weber B fractures (log-rank p < 0.001). Cox regression analysis identified younger age (HR: 0.965, 95% CI: 0.937–0.993, p = 0.016) and Weber C fracture type (HR: 1.811, 95% CI: 1.260–2.602, p = 0.001) as independent predictors of screw breakage. ROC analysis showed that age had moderate discriminative ability (AUC: 0.719, 95% CI: 0.612–0.816), with a cut-off value of 35.5 years. Conclusions: Younger age and Weber C fracture type are associated with an increased risk of syndesmotic screw breakage and Weber C fractures also demonstrating reduced screw survival. These findings may assist in patient counseling; however, the clinical implications of screw breakage remain uncertain. Full article

Finite element analysis is widely used to study spinal biomechanics and to compare surgical strategies under controlled loading conditions. By allowing variation in alignment, fixation, and implant design, these models provide insight into stress redistribution and motion changes that are difficult to isolate experimentally. This review examines spine surgery-focused finite element studies published between 2018 and 2024, with emphasis on interbody fusion techniques, adjacent segment mechanics, and implant-related stress behavior. Across lumbar fusion models, constructs incorporating anterior column support demonstrate lower posterior instrumentation stress than posterior-only approaches, with lateral lumbar interbody techniques showing reduced rod and screw stresses across multiple loading conditions compared with posterior lumbar interbody or posterolateral fusion constructs. In the cervical spine, comparisons of plated and zero-profile anterior cervical discectomy and fusion devices show smaller increases in adjacent-level motion and intradiscal pressure with zero-profile constructs, alongside higher localized stress at fixation interfaces. More recent studies apply finite element methods to implant optimization, alignment planning, and patient-specific modeling. Together, these findings suggest that finite element analysis is increasingly used to support surgical planning and implant design, with continued advances in validation and patient-specific simulation likely to strengthen its clinical relevance. Full article

Background and Objectives: Complicated osteoporotic thoracolumbar fractures represent a major surgical challenge because compromised bone quality predisposes to progressive deformity, neurological deterioration, and fixation failure. This study aimed to evaluate the clinical and radiological outcomes of hybrid stabilization in patients with severe osteoporotic fractures classified as AO Spine-DGOU OF4–OF5. Materials and Methods: This single-center retrospective observational cohort study included 87 consecutively treated patients with complicated osteoporotic thoracolumbar fractures who underwent surgical treatment between 2012 and 2022. Clinical outcomes were assessed using the Visual Analog Scale (VAS) and Oswestry Disability Index (ODI). Radiological outcomes included the regional kyphotic angle (RKA) and interbody fusion graded according to the Bridwell classification. Imaging was reviewed preoperatively, immediately postoperatively, and at follow-up, with 12-month outcomes used for the principal analysis. Additionally, a retrospective comparative analysis was undertaken between the two largest fixation subgroups within the cohort to explore outcome differences across the most representative construct patterns. Results: At 12 months, complete interbody fusion (Bridwell grade I) was achieved in 75.9% of patients. Mean RKA improved from 29.4° ± 14.1° preoperatively to 7.9° ± 8.0° immediately after surgery, with only minimal loss of correction during follow-up. Mean VAS improved from 7.0 ± 1.8 to 2.1 ± 1.2, while mean ODI decreased from 61.3% ± 6.8% to 9.8% ± 1.2% (both p < 0.001). Reoperation for implant-related mechanical failure was required in three patients (3.4%). Conclusions: Hybrid stabilization with cement augmentation was associated with marked improvement in pain, functional disability, and sagittal alignment, as well as a high rate of interbody fusion at 12 months, in patients with complicated osteoporotic thoracolumbar fractures. Given the retrospective observational design, these findings should be interpreted as associations within the treated cohort. Prospective comparative studies are warranted to further validate these results. Full article

Background: Posterior decompression with instrumented fusion (PDF) is a conventional surgical procedure performed in patients with massive ossification of the posterior longitudinal ligament (OPLL); however, it is invasive to the posterior cervical tissues. In this report, we introduce a novel PDF technique, exoscopic minimally invasive open-door laminoplasty with pedicle screw fixation (exLAPPS), to treat cervical OPLL, while minimizing posterior tissue damage. Methods: ExLAPPS was indicated for patients with K-line (−) OPLL or a canal occupying a ratio of ≥50%, allowing decompression from C3 to C7. A small midline incision was used for the navigation reference placement and exoscopic minimally invasive open-door laminoplasty, whereas bilateral lateral incisions were utilized for posterior fixation, including pedicle screw insertion, based on the minimally invasive cervical pedicle screw technique. Results: A total of 7 patients with K-line (-) or a canal occupancy ≥50% underwent exLAPPS for cervical OPLL. The mean operative time was 248 min (range, 165–342 min) and the mean blood loss was 320 mL (range, 50–740 mL). Postoperative imaging demonstrated adequate spinal cord decompression in all patients. A total of 52 pedicle screws were inserted, with a pedicle screw deviation rate of 1.9%. Conclusions: ExLAPPS is a minimally invasive surgical technique designed for posterior decompression and fixation in patients with cervical OPLL. In this preliminary case series, the procedure was successfully performed with acceptable operative time, blood loss, and screw placement accuracy. Although the present study did not include a direct comparison with conventional procedures, these preliminary observations suggest that ExLAPPS is a feasible surgical option for selected patients with cervical OPLL. Full article

Background/Objectives: Lumbar interbody fusion (LIF) is widely utilized to treat multilevel degenerative lumbar spine pathologies. This systematic review aimed to comprehensively review lateral and posterior multilevel LIF procedures and their clinical and radiographic outcomes. Methods: Following the PRISMA guidelines, a search of PubMed, Embase, Web of Science, and Cochrane identified eligible studies. Patient demographics, as well as clinical and radiographic outcomes were collected. Risk of bias was assessed using the MINORS criteria, while randomized trials were evaluated using the RoB-2 tool. An extensive subgroup analysis was completed when that was possible. Results: A total of 45 studies were included consisting of 5623 patients. The pooled outcomes indicated that TLIF demonstrated the lowest operative duration (198.7 ± 77.83 min) and LOS (5.09 ± 2.5 days), alongside favorable ODI (33.68 ± 6.43), VAS leg pain (5.39 ± 0.66), and VAS back pain (4.67 ± 0.79) score gains. Comparative evidence found that LLIF and OLIF provided advantageous radiographic improvement to the posterior approaches. Comparative evidence on techniques challenged the use of autogenous bone within PLIF, PEEK over HA/PA66 cages, and found no advantages in unilateral decompression within TLIF. There was minimal clinical difference in evidence assessing MIS (minimally invasive) vs. open-TLIF or unilateral vs. bilateral pedicle screw fixation (PSF). Conclusions: This is the first systematic review of the multilevel LIF literature, revealing that while pooled data favored TLIF, a publication bias was detected, and comparative evidence reported advantages for lateral and oblique approaches. Given the lack of conclusive evidence, robust study designs are needed to guide clinical decision-making for multilevel lumbar pathology. Full article

Background: Short-segment posterior fixation with intermediate pedicle screws is widely used for thoracolumbar junction (TLJ) burst fractures. However, the optimal penetration depth of intermediate screws remains controversial. The aim of this study was to evaluate whether intermediate screw penetration depth influences radiographic alignment and functional outcomes at 12 months following short-segment posterior fixation of AO Spine A3–A4 thoracolumbar burst fractures. Methods: This retrospective cohort study included 105 patients with AO Spine A3–A4 TLJ burst fractures treated between 1 January 2019 and 31 December 2022. All patients underwent short-segment posterior stabilization with intermediate screws at the fracture level. Penetration depth was categorized as either <50% (Group A) or ≥50% (Group B) of vertebral body depth. Radiographic parameters (kyphotic deformity, segmental kyphosis, sagittal index, anterior vertebral body height) and clinical outcomes (Visual Analog Scale and Oswestry Disability Index) were evaluated preoperatively and at 12 months. Results: Both groups demonstrated significant postoperative improvement in radiographic alignment and clinical outcomes. No statistically significant differences were detected between groups in kyphotic correction, loss of correction, pain reduction, disability scores, operative time, length of stay, or complication rates at 12 months. Conclusions: Within the limitations of this retrospective study, intermediate screw penetration depth did not significantly influence radiographic or clinical outcomes at 12 months. Screw length selection may therefore depend on anatomical considerations and surgeon preference rather than expected differences in clinical performance. Full article

Introduction: Slipped capital femoral epiphysis (SCFE) is commonly treated using percutaneous in situ fixation. After screw fixation, remodelling of the proximal femur can occur; however, the factors influencing this process are poorly understood. This study aimed to measure the amount of remodelling after in situ SCFE fixation and determine the influence of the transphyseal screw position across the physis. Methods: In this retrospective study, all eligible patients with SCFE who had percutaneous screw fixation at Erasmus MC—Sophia Children’s Hospital between 2012 and 2020 were included. The amount of remodelling was determined by measuring the Southwick angle, alpha angle and displacement from Klein’s line directly after screw fixation and at final follow-up. Transphyseal screw position was measured through AP and frog-leg lateral radiographs by measuring the placement of the centre of the screw in relation to the centre of the epiphysis. A linear mixed model was used to determine factors influencing the amount of remodelling. Results: 86 patients with 96 affected hips were included; the mean age was 12.4 (±2.0) years at surgery, and the mean follow-up duration was 3.7 (±2.0) years. All measurements showed significant remodelling at follow-up compared to baseline. Over the follow-up period, the mean change in Southwick angle was 4.6° (95% CI: 2.5; 6.7, p < 0.001), the mean change in Alpha angle was 10.4° (95% CI: 7.3; 13.5, p < 0.001) and the mean change in displacement from Klein’s line was −1.2 mm (95% CI: −1.7; −0.61, p < 0.001). Linear mixed model analyses showed that remodelling was significantly correlated with deformity at baseline for all measurements. Also, a more lateral screw position was significantly correlated with more improvement in displacement from Klein’s line (estimate: −4.2, 95% CI: −8.0 to −0.5). However, the effect observed was relatively small. Conclusions: A statistically significant amount of remodelling was measured after percutaneous screw fixation for patients with SCFE. The amount of remodelling was relatively limited, but was shown to be influenced by the severity of the initial slip and a more lateral transphyseal screw position. Full article

By using virtual surgical planning (VSP) and 3D printed guides, complex maxillofacial defects can be reconstructed with high accuracy and predictability. A fully digital workflow resulting in a modular all-in-one 3D printed guide system for fibula osteotomies, bone segment positioning, fully guided dental implant placement and dental prosthesis fixation for mandibular reconstruction was developed at Ghent University Hospital. A follicular ameloblastoma of the left mandible was resected in a 28-year-old male. The defect was reconstructed with a two-segment fibular free flap with immediate placement of three dental implants and immediate implant loading with a screw-retained bridge. A split thickness skin graft and Elemental PerioPlast were used as wound dressing. Comparison of the preoperative planning with the postoperative CT-scan showed a deviation immediately after surgery, which was no longer present at the 6-month follow-up. The patient achieved a stable occlusion and 44 mm mouth opening and reported high satisfaction. This case illustrates that fully digital, immediate mandibular reconstruction with simultaneous implant placement and prosthetic rehabilitation is feasible and accurate and enhances early functional recovery. Future improvements in intraoperative validation may further refine accuracy and reproducibility in complex oncologic reconstructions. Full article

Background/Objectives: Frontal sinus fractures are uncommon injuries that may cause persistent aesthetic deformity when the anterior wall is comminuted, as small irregular fragments are difficult to stabilize with conventional osteosynthesis alone. Methods: We describe a point-of-care digital workflow combining 3D planning/printing and cyanoacrylate-assisted fixation for an isolated comminuted anterior frontal sinus wall fracture. A young adult presented with a depressed forehead contour after assault; computed tomography confirmed at least four displaced fragments. Results: A two-part 3D-printed biomodel was manufactured in-house to visualize the defect and guide extracorporeal reconstruction. Through a coronal approach, fragments were mobilized and anatomically reassembled using the biomodel as a reference; sinonasal drainage was preserved and sinus obliteration was not required. Because fragment size and geometry limited screw purchase, a modified N-butyl-2-cyanoacrylate adhesive (Glubran 2) was applied as an adjunct to maintain reduction, followed by reinforcement with titanium microplates. Postoperative recovery was uneventful, with immediate restoration of forehead contour and no early complications; postoperative imaging confirmed satisfactory alignment. Conclusions: This case supports the feasibility of integrating point-of-care 3D biomodeling with cyanoacrylate as a coadjuvant to microplate fixation in selected comminuted frontal sinus fractures to enhance fragment handling and contour restoration. Full article

(1) Background and introduction: High-demand lumbosacral fusions are often supplemented with sacral-alar-iliac (SAI) screws. The idealized SAI trajectory was estimated to traverse 35 mm of sacrum before crossing the sacroiliac (SI) joint. However, there is debate on how much osseous purchase SAI screws achieve. The goal of this study was to determine the amount of osseous engagement achieved using a porous fusion–fixation screw (PFFS) when placed in a stacked SAI configuration. (2) Materials and methods: We retrospectively reviewed 40 consecutive patients who underwent sacropelvic fixation with stacked PFFS at our institution from 1 June 2022 to 30 June 2023, using intraoperative computed tomography (CT)-based computer navigation. A snapshot of each screw was taken and the length of purchase within the sacrum and ilium was measured on the axial image along the anterior and posterior aspect of each screw. Nineteen patients did not have adequate images available for review and were excluded. (3) Results: The overall mean anterior sacral engagement was 38.6 mm (±8.2 mm), which was found to be statistically significantly greater than the hypothesized threshold of 35 mm (p < 0.001), while posterior sacral engagement was 28.1 mm (±8.6 mm), which was not found to be statistically significantly greater than the hypothesized threshold of 35 mm (p = 1). The mean difference in sacral engagement between the anatomical location for the cephalad screws was 10.3 mm (p < 0.001) and 10.6 mm (p < 0.001) for the caudal screws. The total sacral surface area available for bone ingrowth for bilateral stacked PFFS was calculated to be 3338.3 mm², while the total iliac surface area available for bone ingrowth was 4364.8 mm². A mean difference in surface area availability between anatomical locations was −689.5 mm² (p < 0.001) for the sacrum and 689.5 mm² (p < 0.001) for the ilium. (4) Discussion and conclusions: The SAI trajectory screws in this cohort of patients achieved approximately 39 mm of sacrum engagement anteriorly and 28 mm posteriorly. This is consistent with prior estimates based on the idealized SAI pathway through the sacrum. PFFSs allow for simultaneous sacropelvic fixation and SI joint fusion, which may reduce the incidence of de novo SI joint pain in patients with long fusion constructs. Full article

Background: Reverse shoulder arthroplasty (RSA) relies on secure baseplate fixation to the glenoid. This carries a risk of suprascapular nerve (SSN) injury during peripheral screw insertion. Although fixed safe zones have been described, it remains unclear whether these scale with scapular morphometry or whether common screw positions confer differential SSN risk. Methods: Twenty cadaveric shoulders (ten pairs) were dissected. The superior safe zone (distance from the supraglenoid tubercle to SSN at the suprascapular notch) and posterior safe zone (distance from the glenoid rim to SSN at the spinoglenoid notch) were measured. Scapular dimensions (height, spine length, width) were measured. In ten shoulders, simulated RSA baseplate fixation was performed with superior screws placed at 11, 12, or 1 o’clock and posterior screws at 8, 9, or 10 o’clock. Screw lengths were based on glenoid depth. Cortical breach and SSN proximity were recorded. Linear regression assessed relationships between scapular dimensions and safe zones. Results: The superior safe zone (mean 2.9 ± 0.5 cm) significantly correlated with scapular dimensions (r = 0.78–0.86; p < 0.0001). All superior screws remained intraosseous across configurations. The posterior safe zone (1.9 ± 0.6 cm) showed no correlation. Posterior cortical breach occurred in 50% of specimens across all tested positions and was associated with smaller scapular spine length (p = 0.027). No significant difference in SSN proximity was observed between posterior screw positions. Conclusions: Scapular dimensions predict the superior, but not posterior, safe zone. Scapulae with shorter spine lengths demonstrated increased risk of posterior cortical breach, independent of screw position. These findings establish anatomical scalability of the superior safe zone and suggest that scapular morphometry may inform preoperative RSA planning; however, prospective validation is needed before routine clinical implementation. Full article