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Frontiers in Bioengineering and... 2023Spinal fusion is the most common surgical treatment for the management of degenerative spinal disease. However, complications such as screw loosening lead to painful...
Spinal fusion is the most common surgical treatment for the management of degenerative spinal disease. However, complications such as screw loosening lead to painful pseudoarthrosis, and are a common reason for revision. Optimization of screw trajectories to increase implant resistance to mechanical loading is essential. A recent optimization method has shown potential for determining optimal screw position and size based on areas of high bone elastic modulus (E-modulus). The aim of this biomechanical study was to verify the optimization algorithm for pedicle screw placement in a cadaveric study and to quantify the effect of optimization. The pull-out strength of pedicle screws with an optimized trajectory was compared to that of a traditional trajectory. Twenty-five lumbar vertebrae were instrumented with pedicle screws (on one side, the pedicle screws were inserted in the traditional way, on the other side, the screws were inserted using an optimized trajectory). An improvement in pull-out strength and pull-out strain energy of the optimized screw trajectory compared to the traditional screw trajectory was only observed for E-modulus values greater than 3500 MPa cm. For values of 3500 MPa cm or less, optimization showed no clear benefit. The median screw length of the optimized pedicle screws was significantly smaller than the median screw length of the traditionally inserted pedicle screws, < 0.001. Optimization of the pedicle screw trajectory is feasible, but seems to apply only to vertebrae with very high E-modulus values. This is likely because screw trajectory optimization resulted in a reduction in screw length and therefore a reduction in the implant-bone interface. Future efforts to predict the optimal pedicle screw trajectory should include screw length as a critical component of potential stability.
PubMed: 37954015
DOI: 10.3389/fbioe.2023.1270522 -
Current Reviews in Musculoskeletal... Jun 2024Anterior shoulder instability is associated with concomitant injury to several stabilizing structures of the shoulder, including glenoid bone loss. While instability is... (Review)
Review
PURPOSE OF REVIEW
Anterior shoulder instability is associated with concomitant injury to several stabilizing structures of the shoulder, including glenoid bone loss. While instability is most common in young athletes and patients with predisposing conditions of hyperlaxity, recurrent shoulder instability can occur throughout various age ranges and may lead to longer term effects including pain and shoulder arthritis. Glenoid bone loss exceeding certain thresholds is generally treated by glenoid reconstruction via bone block augmentation to adequately stabilize the glenohumeral joint. These procedures increase the width of the articular surface on which the humeral head can translate before dislocation and, based on the procedure performed, provide a sling effect via the conjoined tendon, and increase tension to support the anterior capsule. The purpose of this review is to summarize the available literature regarding bone block fixation techniques.
RECENT DEVELOPMENTS
Various fixation techniques have been utilized to secure bone block transfers. Though screw fixation has traditionally been used for bone block fixation, suture buttons, suture anchors, and all-suture techniques have been utilized in attempts to avoid complications associated with the use of screws. Biomechanical studies report variable force-resistance, displacement, and mode of failure when comparing screw to suture button-based fixation of glenoid bone blocks. Clinical and radiographic studies have shown these novel suture-based techniques to be comparable, and in some cases advantageous, to traditional screw fixation techniques. While screw fixation has long been the standard of care in glenoid bone block procedures, it is associated with high complication rates, leading surgeons to endeavor toward new fixation techniques. In available biomechanical studies, screw fixation has consistently demonstrated high maximal load-to-failure and displacement with cyclic loading. Studies have reported similar clinical and radiographic outcomes in both screw and suture-based fixation methods, with evidence of reduced bone resorption with suture fixation. While suture button fixation is associated with a higher rate of recurrent instability, overall complication rates are low. Future research should address biomechanical shortcomings of suture-based fixation techniques and continue to assess long-term follow-up of patients treated with each fixation method.
PubMed: 38587597
DOI: 10.1007/s12178-024-09895-x -
Turkish Journal of Medical Sciences 2023Developmental dysplasia of the hip (DDH) is the most common cause of secondary hip arthrosis. The primary purpose of this study was to assess the results of an oversized...
BACKGROUND/AIM
Developmental dysplasia of the hip (DDH) is the most common cause of secondary hip arthrosis. The primary purpose of this study was to assess the results of an oversized hemispherical cup via the press-fit technique used for Crowe type II and III DDH without screws and to determine if adequate medialization and initial stability of the acetabular component would allow us to avoid screw and graft use.
MATERIALS AND METHODS
Between February 2012 and May 2020, the current study analyzed 43 hips with Crowe type II and III DDH treated with a porous-coated cup by placing the press-fit technique or screw. The acetabular cup was fixed with the press-fit technique without additional screws in 27 hips and with screws in 16 hips. The inclusion criterion in this study was a minimum 2-year-period after the surgery.
RESULTS
The mean duration of follow-up was 6.83 2.67 years in the press-fit group and 6.21 2.01 years in the screw group. The mean age of the patients was 47.96 12.37 years in the press-fit group and 50.5 12.37 years in the screw group. Measurements revealed that the hip center of rotation (HCR) was located more medially and superiorly postoperatively than preoperatively in both groups. The mean cup coverage in the screw group was 85.58% 7.51% (75.3%-97.2%), while it was less than 90.41% 6.15% (76.3%-98.2%) in the press-fit group (p = 0.038). No component was revised because of loosening, and all of the implants were radiologically stable within the observation period. No statistically significant differences were observed regarding the postoperative limp-length discrepancy between the groups (p = 0.496).
CONCLUSION
Press-fit implantation of a porous-coated acetabular component without screws can also be used as an alternative method for THA in Crowe type II and III DDH. The initial stability was obtained using the press-fit technique with a small cup positioned more medially and superiorly, which may allow the surgeon to avoid screw and graft use.
Topics: Humans; Female; Male; Middle Aged; Adult; Arthroplasty, Replacement, Hip; Hip Prosthesis; Bone Screws; Bone Transplantation; Developmental Dysplasia of the Hip; Hip Dislocation, Congenital; Acetabulum; Treatment Outcome; Prosthesis Design
PubMed: 38813005
DOI: 10.55730/1300-0144.5712 -
Bioactive Materials Oct 2023The microstructural architecture of remodeled bone in the peri-implant region of screw implants plays a vital role in the distribution of strain energy and implant...
The microstructural architecture of remodeled bone in the peri-implant region of screw implants plays a vital role in the distribution of strain energy and implant stability. We present a study in which screw implants made from titanium, polyetheretherketone and biodegradable magnesium-gadolinium alloys were implanted into rat tibia and subjected to a push-out test four, eight and twelve weeks after implantation. Screws were 4 mm in length and with an M2 thread. The loading experiment was accompanied by simultaneous three-dimensional imaging using synchrotron-radiation microcomputed tomography at 5 μm resolution. Bone deformation and strains were tracked by applying optical flow-based digital volume correlation to the recorded image sequences. Implant stabilities measured for screws of biodegradable alloys were comparable to pins whereas non-degradable biomaterials experienced additional mechanical stabilization. Peri-implant bone morphology and strain transfer from the loaded implant site depended heavily on the biomaterial utilized. Titanium implants stimulated rapid callus formation displaying a consistent monomodal strain profile whereas the bone volume fraction in the vicinity of magnesium-gadolinium alloys exhibited a minimum close to the interface of the implant and less ordered strain transfer. Correlations in our data suggest that implant stability benefits from disparate bone morphological properties depending on the biomaterial utilized. This leaves the choice of biomaterial as situational depending on local tissue properties.
PubMed: 37250865
DOI: 10.1016/j.bioactmat.2023.05.006 -
Journal of Orthopaedic Surgery and... Dec 2023Various fixation methods are available for tibiotalocalcaneal arthrodesis: nail, plate, or screws. An intramedullary bone stabilization system within a balloon catheter...
BACKGROUND
Various fixation methods are available for tibiotalocalcaneal arthrodesis: nail, plate, or screws. An intramedullary bone stabilization system within a balloon catheter has not previously been used in tibiotalocalcaneal arthrodesis. The aim of this study was to compare the stability of these techniques.
METHODS
Twenty-four lower legs from fresh-frozen human cadavers were used. Tibiotalocalcaneal arthrodesis was performed with a retrograde nail, a lateral locking plate, three cancellous screws, or an intramedullary bone stabilization system. The ankles were loaded cyclically in plantarflexion and dorsiflexion.
RESULTS
For cyclic loading at 125 N, the mean range of motion was 1.7 mm for nail, 2.2 mm for plate, 6.0 mm for screws, and 9.0 mm for the bone stabilization system (P < .01). For cyclic loading at 250 N, the mean range of motion was 4.4 mm for nail, 7.5 mm for plate, 12.1 mm for screws, and 14.6 mm for the bone stabilization system (P < .01). The mean cycle of failure was 4191 for nail, 3553 for plate, 3725 for screws, and 2132 for the bone stabilization system (P = .10).
CONCLUSIONS
The stability of the tibiotalocalcaneal arthrodesis differs depending on the fixation method, with nail or plate showing the greatest stability and the bone stabilization system the least. When three screws are used for tibiotalocalcaneal arthrodesis, the stability is intermediate. As the biomechanical stability of the bone stabilization system is low, it cannot be recommended for tibiotalocalcaneal arthrodesis.
Topics: Humans; Bone Nails; Ankle Joint; Biomechanical Phenomena; Arthrodesis; Cadaver
PubMed: 38105223
DOI: 10.1186/s13018-023-04444-7 -
BMC Oral Health Dec 2023The aim of this study was to evaluate the impact of mini-screw placement on the alveolar ridge using a split-mouth design. Twelve beagles underwent bilateral extraction...
The aim of this study was to evaluate the impact of mini-screw placement on the alveolar ridge using a split-mouth design. Twelve beagles underwent bilateral extraction of their lateral teeth. In the immediate group, a mini-screw was unilaterally placed approximately 3-4 mm below the alveolar crest of the extraction site on the experimental side. The delayed group received mini-screws six weeks after tooth extraction. On average, the dogs were sacrificed after 11 weeks, and the maxillary bones were excised and scanned using cone-beam computed tomography (CBCT). Histopathological examinations were conducted to assess inflammation and bone formation scores. The results showed that in the immediate group, bone height was significantly greater on the intervention side compared to the control side (p < 0.05), whereas there was no significant difference in the delayed group. In both groups, there was a significant increase in bone density around the mini-screws compared to the control sides (p < 0.05). Mini-screw insertion led to a significant enhancement of bone growth in both groups (p < 0.05), with no notable differences between the two groups. The mini-screws did not have any impact on bone inflammation or width. Overall, both immediate and delayed mini-screw placement in the extraction socket positively influenced bone dimensions, density, and histological properties. However, immediate insertion was more effective than delayed placement in preserving vertical bone height, despite delayed insertion resulting in higher bone density.
Topics: Dogs; Animals; Tooth Socket; Alveolar Bone Loss; Bone Density; Alveolar Process; Tooth Extraction; Bone Screws; Cone-Beam Computed Tomography
PubMed: 38057827
DOI: 10.1186/s12903-023-03703-7 -
Materials (Basel, Switzerland) Oct 2023The first metatarsophalangeal (MTP) joint is a frequently loaded joint, handling loads up to 90% of bodyweight. First MTP arthrodesis is a frequently performed procedure... (Review)
Review
The first metatarsophalangeal (MTP) joint is a frequently loaded joint, handling loads up to 90% of bodyweight. First MTP arthrodesis is a frequently performed procedure designed to improve pain in patients with degenerative MTP joint disease. There are a wide variety of fixation constructs for this procedure without consensus on the most effective method. The purpose of this study was to compare the biomechanical integrity of various constructs utilized for first MTP arthrodesis. A systematic review of the literature was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, CINAHL, MEDLINE, and Web of Science databases were searched from inception to 18 June 2023. Articles discussing the biomechanics of first MTP arthrodesis constructs were included. A total of 168 articles were retrieved. A total of 20 articles involving 446 cadaveric and synthetic bone constructs were included in the final review. Of the six articles comparing dorsal plating with compression screws to crossed interfragmentary screws, five found that dorsal plating had significantly higher stiffness. All three studies assessing shape-memory staples found them to be significantly less stable than crossed screws or dorsal plates alone. Both studies evaluating fully threaded screws found them to be stronger than crossed cancellous screws. Wedge resections have been shown to be 10 times stronger than standard planar or conical excision. Dorsal plating with compression screws is the gold standard for MTP arthrodesis. However, more research into newer methods such as fully threaded screws and wedge resections with an increased focus on translation to clinical outcomes is needed.
PubMed: 37834699
DOI: 10.3390/ma16196562 -
Journal of Orthopaedic Surgery and... Aug 2023Our aim was to determine the best operative procedure in human participants with a displaced or non-displaced femoral neck fracture comparing cannulated screw (CS)... (Meta-Analysis)
Meta-Analysis
Cannulated screws versus dynamic hip screw versus hemiarthroplasty versus total hip arthroplasty in patients with displaced and non-displaced femoral neck fractures: a systematic review and frequentist network meta-analysis of 5703 patients.
BACKGROUND
Our aim was to determine the best operative procedure in human participants with a displaced or non-displaced femoral neck fracture comparing cannulated screw (CS) fixation, dynamic hip screw (DHS) fixation, hemiarthroplasty (HA), and total hip arthroplasty (THA) in terms of surgical and functional outcomes, reoperation and postoperative complications.
METHODS
We searched PubMed, The Cochrane Library, Clinical trials, CINAHL, and Embase for randomized controlled trials (RCTs) or quasi-RCTs up to 31 July 2022. A frequentist network meta-analysis was performed to assess the comparative effects of the four operative procedures, using fixed-effects and random-effects models. Mean differences (MDs) with 95% confidence intervals (CIs) were estimated for continuous variables and odds ratios (ORs) with 95% CIs were estimated for binary variables.
RESULTS
A total of 33 RCTs with 5703 patients were included in our network meta-analysis. CS fixation was best in terms of operation time (CS: MD = - 57.70, 95% CI - 72.78; - 42.62; DHS: MD = - 53.56, 95% CI - 76.17; - 30.95; HA: MD = - 20.90, 95% CI - 30.65; - 11.15; THA: MD = 1.00 reference) and intraoperative blood loss (CS: MD = - 3.67, 95% CI - 4.44; - 2.90; DHS: MD = - 3.20, 95% CI - 4.97; - 1.43; HA: MD = - 1.20, 95% CI - 1.73; - 0.67; THA: MD = 1.00 reference). In life quality and functional outcome, measured at different time points with EQ-5D and the Harris Hip Score (HHS), THA ranked first and HA second (e.g. EQ-5D 2 years postoperatively: CS: MD = - 0.20, 95% CI - 0.29; - 0.11; HA: MD = - 0.09, 95% CI - 0.17; - 0.02; THA: MD = 1.00 reference; HHS 2 years postoperatively: CS: MD = - 5.50, 95% CI - 9.98; - 1.03; DHS: MD = - 8.93, 95% CI - 15.08; - 2.78; HA: MD = - 3.65, 95% CI - 6.74; - 0.57; THA: MD = 1.00 reference). CS fixation had the highest reoperation risk, followed by DHS fixation, HA, and THA (CS: OR = 9.98, 95% CI 4.60; 21.63; DHS: OR = 5.07, 95% CI 2.15; 11.96; HA: OR = 1.60, 95% CI 0.89; 2.89; THA: OR = 1.00 reference).
CONCLUSION
In our cohort of patients with displaced and non-displaced femoral neck fractures, HHS, EQ-5D, and reoperation risk showed an advantage of THA and HA compared with CS and DHS fixation. Based on these findings, we recommend that hip arthroplasty should be preferred and internal fixation of femoral neck fractures should only be considered in individual cases.
LEVEL OF EVIDENCE I
a systematic review of randomized controlled trials.
TRIAL REGISTRATION
PROSPERO on 10 August 2022 (CRD42022350293).
Topics: Humans; Arthroplasty, Replacement, Hip; Hemiarthroplasty; Network Meta-Analysis; Femoral Neck Fractures; Bone Screws; Fracture Fixation, Internal
PubMed: 37626370
DOI: 10.1186/s13018-023-04114-8 -
Orthopaedic Surgery Nov 2023To develop a novel semi-cannulated lateral mass screw (SC-LMS) for cervical posterior fixations and compare the fixation stability and safety of SC-LMS with regular...
A Novel Semi-Cannulated Screw Enhanced Bone Cement Augmentation and Pullout Strength in Posterior Cervical Lateral Mass Screw Fixations: An In Vitro Biomechanical and Morphological Study.
OBJECTIVE
To develop a novel semi-cannulated lateral mass screw (SC-LMS) for cervical posterior fixations and compare the fixation stability and safety of SC-LMS with regular solid lateral mass screw (S-LMS) in bone cement augmentation and pullout strength using fresh cadaveric cervical vertebrae.
METHODS
The conventional multiaxial screw for cervical lateral mass fixation was modified to a cannulated screw with two lateral holes, used for bone cement injection in situ. Eight fresh human cervical vertebrae (C3, C4, and C5) were collected and used. μCT scan was performed to evaluate the bone quality of the lateral masses, including bone mineral density (BMD), trabecular thickness (Tb.Th), and trabecular separation (Tb.Sp). SCLMS or S-LMS were randomly inserted into the paired cervical vertebrae and pulled out as a screw loosening model. These screws were reinserted in with bone cement augmentation, scanned by μCT to obtain the bone cement distribution along the screws, and pulled out to test the screw purchase strength.
RESULTS
Fmax values exhibited strong positive correlations with the local BMD (𝑟 = 0.8640, p < 0.0001) and Tb.Th (𝑟 = 0.6795, p = 0.0038), whereas a negative correlation with Tb.Sp (𝑟 = -0.5567, p = 0.0251). A significant difference was observed between the Fmax before and after PMMA injection on the SC-LMS side (p = 0.019). The SC-LMS exhibited lower risk of cement leakage than S-LMS after PMMA injection, and a positive correlation was observed between 𝐹max and the distribution volumes on the SC-LMS side.
CONCLUSION
The novel SC-LMS provides more robust fixation stability and is safer than the S-LMS for PMMA augmentation, which may be related to the cement-screw-cement-bone complex formation.
Topics: Humans; Bone Cements; Polymethyl Methacrylate; Bone Screws; Bone Density; Cervical Vertebrae; Biomechanical Phenomena
PubMed: 37712328
DOI: 10.1111/os.13859 -
Heliyon Mar 2024The academia has increasingly acknowledged the superior biomechanical performance of the hybrid fixation technique in recent years. However, there is a lack of research...
BACKGROUND
The academia has increasingly acknowledged the superior biomechanical performance of the hybrid fixation technique in recent years. However, there is a lack of research on the hybrid fixation technique using BCS (Bilateral Cortical Screws) and BMCS (Bilateral Modified Cortical Screws). This study aims to investigate the biomechanical performance of the BCS and BMCS hybrid fixation technique in transforaminal lumbar interbody fusion (TLIF) at the L4-L5 segment in a complete lumbar-sacral finite element model.
METHODS
Three cadaver specimens are used to construct three lumbar-sacral finite element models. The biomechanical properties of various fixation technologies (BCS-BCS, BMCS-BMCS, BMCS-BCS, and BCS-BMCS) are evaluated at the L4-5 segment with a TLIF procedure conducted, including the range of motion (ROM) of the L4-5 segment, as well as the stress experienced by the cage, screws, and rods. The testing is conducted under specific loading conditions, including a compressive load of 400 N and a torque of 7.5Nm, subjecting the model to simulate flexion, extension, lateral bending, and rotation.
RESULTS
No significant variations are seen in the ROM at the L4-5 segment when comparing the four fixation procedures during flexion and extension. However, when it comes to lateral bending and rotation, the ROM is ordered in descending order as BCS-BCS, BCS-BMCS, BMCS-BMCS, and BMCS-BCS. The maximum stress experienced by the cage is observed to be highest within the BMCS-BCS technique during movements including flexion, extension, and lateral bending. Conversely, the BMCS-BMCS technique exhibits the highest cage stress levels during rotational movements. The stress applies to the screws and rods order the sequence of BCS-BCS, BCS-BMCS, BMCS-BCS, and BMCS-BMCS throughout all four working conditions.
CONCLUSION
The BMCS-BCS technique shows better biomechanical performance with less ROM and lower stress on the internal fixation system compared to other fixation techniques. BMCS-BMCS technology has similar mechanical performance to BMCS-BCS but has more contact area between screws and cortical bone, making it better for patients with severe osteoporosis.
PubMed: 38434416
DOI: 10.1016/j.heliyon.2024.e26294