Cortical Screws Research Articles

Syndesmotic injury with ankle fracture: A systematic review of screw vs dynamic fixation.

Cortical screw fixation across the tibiofibular joint is the mainstay of treatment for syndesmotic injury. Dynamic fixation devices have been developed offering similar advantages to screw fixation in terms of reduction and stability of the syndesmosis. Dynamic fixation may also facilitate a more physiological movement between the tibiofibular joint and thus incur less morbidity. Patient's rehabilitation potential is enhanced and reduces the need for hardware removal.Our systematic review aims to analyse the relevant current literature and compare screw fixation to dynamic fixation in the treatment of syndesmotic injury associated with acute ankle fractures.A literature search was performed on Pubmed and Ovid Medline to find scientific papers relating to syndesmotic fixation in acute ankle fractures. Papers were screened and included dependent on predetermined criteria. Risk of bias was assessed after screening full papers by two independent reviewers. Tables and analysis were made using Microsoft excel.A total of 8 papers with 673 patients were included. We found no functional difference between screw fixation or dynamic fixation groups at final follow-up. Three papers showed statistically significant lower rates of reoperation in the dynamic fixation group.Dynamic fixation may offer lower post operative complications and reoperation rates. Therefore, dynamic fixation may be a beneficial alternative treatment compared to traditionally used syndesmotic screws.

Pull-out strength of screws in long bones at different insertion angles: finite element analysis and experimental investigations

Abstract Different types of plates are available to allow insertion of screws for internal fixation of long bone fractures. The aim of the study was to determine the effect of the insertion of screws at different angles on a long bone to the pull-out strength. Using 3D printed bone models, we tested the pull-out strength of screws in long bones at insertion angles between 0 and 40° with both finite element analysis and on printed models experimentally and compared the results. Test samples and cortical screws used were modeled with SolidWorks software and analyzed with Ansys software. As the screw insertion angle increases, the pull-out forces on the test specimens increase from 61.14 ± 3.5 N at 0° to 273 ± 6.8 N at 40° with an exception of a small drop between 15 and 20° from 235.4 ± 6.2 to 233 ± 6.9 N. Both methods showed an increase in the pull-out strength of screws as the insertion angle increases. This might be applicable in the clinical practice of bone fixation. Further studies on plate and screw fixation are needed to complement the findings.

Assessment of material identification and quantification in the presence of metals using spectral photon counting CT.

Spectral Photon Counting Computed Tomography (SPCCT), a ground-breaking development in CT technology, has immense potential to address the persistent problem of metal artefacts in CT images. This study aims to evaluate the potential of Mars photon-counting CT technology in reducing metal artefacts. It focuses on identifying and quantifying clinically significant materials in the presence of metal objects. A multi-material phantom was used, containing inserts of varying concentrations of hydroxyapatite (a mineral present in teeth, bones, and calcified plaque), iodine (used as a contrast agent), CT water (to mimic soft tissue), and adipose (as a fat substitute). Three sets of scans were acquired: with aluminium, with stainless steel, and without a metal insert as a reference dataset. Data acquisition was performed using a Mars SPCCT scanner (Microlab 5×120); operated at 118 kVp and 80 μA. The images were subsequently reconstructed into five energy bins: 7-40, 40-50, 50-60, 60-79, and 79-118 keV. Evaluation metrics including signal-to-noise ratio (SNR), linearity of attenuation profiles, root mean square error (RMSE), and area under the curve (AUC) were employed to assess the energy and material-density images with and without metal inserts. Results show decreased metal artefacts and a better signal-to-noise ratio (up to 25%) with increased energy bins as compared to reference data. The attenuation profile also demonstrated high linearity (R2 >0.95) and lower RMSE across all material concentrations, even in the presence of aluminium and steel. Material identification accuracy for iodine and hydroxyapatite (with and without metal inserts) remained consistent, minimally impacting AUC values. For demonstration purposes, the biological sample was also scanned with the stainless steel volar implant and cortical bone screw, and the images were objectively assessed to indicate the potential effectiveness of SPCCT in replicating real-world clinical scenarios.

Spine Surgical Robotics: Current Status and Recent Clinical Applications.

With the development of artificial intelligence and the further deepening of medical-engineering integration, spine surgical robot-assisted (RA) technique has made significant progress and its applicability in clinical practice is constantly expanding in recent years. In this review, we have systematically summarized the majority of literature related to spine surgical robots in the past decade, and not only classified robots accordingly, but also summarized the latest research progress in RA technique for screw placement such as cervical, thoracic, and lumbar pedicle screws, cortical bone trajectory screws, cervical lateral mass screws, and S2 sacroiliac screws; guiding targeted puncture and placement of endoscope via the intervertebral foramen; complete resection of spinal tumor tissue; and decompressive laminectomy. In addition, this report also provides a detailed evaluation of RA technique's advantages and disadvantages, and clarifies the accuracy, safety, and practicality of RA technique. We consider that this review can help clinical physicians further understand and familiarize the current clinical application status of spine surgical robots, thereby promoting the continuous improvement and popularization of RA technique, and ultimately benefiting numerous patients.

COMPARATIVE ANALYSIS OF CONSERVATIVE AND SURGICAL TREATMENT OUTCOMES IN PATIENTS WITH DIAPHYSEAL HUMERUS FRACTURES

The frequency of diaphyseal humerus fractures varies from 1% to 5% of the total number of skeletal fractures in humans. A clear bimodal gender and age distribution of patients with fractures in the studied area has been established. The main methods of treatment for closed intra-articular humerus fractures are conservative functional and surgical treatment. Treatment of diaphyseal humerus trauma involves not only restoring the axis and length of the bone but also ensuring sufficient mobility of adjacent joints. The aim of the study was to conduct a comparative analysis of the outcomes of conservative and surgical treatment in patients with diaphyseal humerus fractures. The study involved 57 patients with diaphyseal humerus fractures aged from 19 to 83 years. The first clinical group comprised of 24 patients aged from 24 to 80 years who were treated using functional fixation devices. The second clinical group consisted of 33 patients aged from 19 to 83 years who were treated using surgical techniques, namely antegrade locked intramedullary nailing and cortical plate and screw osteosynthesis. Rehabilitation measures were initiated within the first two days for patients in the first group and in the early postoperative period for patients in the second group. The range of motion of adjacent joints was assessed using the CMS and MEPS scales. The use of surgical treatment techniques in combination with early rehabilitation measures, compared to conservative functional treatment, allows achieving significantly higher and statistically significant (p<=0.01) functional outcomes of elbow joint mobility.

The Influence of Titanium-coated Poryetheretherketone Cages in Fusion Status after Posterior Lumbar Interbody Fusion with Cortical Bone Trajectory Screw Fixation

Posterior lumbar interbody fusion (PLIF) with cortical bone trajectory (CBT) screw fixation (CBT-PLIF) shows potential for reducing adjacent segmental disease. Previously, our investigations revealed a relatively lower fusion rate with the use of carbon fiber-reinforced polyetheretherketone (CP) cages in CBT-PLIF compared with traditional pedicle screw fixation (PS-PLIF) using CP cages. This study aims to evaluate whether the implementation of titanium-coated polyetheretherketone (TP) cages can enhance fusion outcomes in CBT-PLIF. A retrospective analysis was conducted on 68 consecutive patients who underwent CBT-PLIF with TP cages (TP group) and 89 patients who underwent CBT-PLIF with CP cages (CP group). Fusion status was assessed using computed tomography at 1 year postoperatively and dynamic plain radiographs at 2 years postoperatively. No statistically significant differences in fusion rates were observed at 1 and 2 years postoperatively between the TP group (86.8% and 89.7%, respectively) and the CP group (77.5% and 88.8%, respectively). Notably, the CP group exhibited a significant improvement in fusion rate from 1 to 2 years postoperatively (P= 0.002), while no significant improvement was observed in the TP group. Examination of temporal changes in fusion rates reveals that only the TP group achieved a peak fusion rate 1 year postoperatively. This implies that TP cages may enhance the fusion process even after CBT-PLIF. Nevertheless, the definitive efficacy of TP cages for CBT-PLIF remains uncertain in the context of overall fusion rates.

Standardized reduction and palmar plating of dorsally displaced distal radius fractures for safe and atraumatic reconstruction of the anatomy of the radius

Standardization of palmar plate osteosynthesis in order to consequently achieve physiologic anatomy of the distal radius end. Unstable dorsally displaced distal radius fractures or fractures that should be treated functionally. Severe intraarticular joint depression that cannot be reduced with either apalmar or arthroscopic assisted approach. Patient in supine position with the forearm supinated on arm table. Radiopalmar incision along the radial border of the flexor carpi radialis tendon. Detachment of the pronator quadratus muscle from radial to ulnar. Gross reduction with eventual correction of adorsal or radial shift. Placement of the angular stable plate and preliminary fixation with anonangular stable cortical screw in the long hole at the radius shaft. Fluoroscopic control of axial alignment in the anteroposterior view and of correct distal position of the plate in the lateral view under reduction condition. Placement of one or two angular stable screws at the shaft. Under subtle reduction with flexion, ulnar deviation and axial traction placement of two K‑wires via the holes at the distal edge of the plate. These wires mostly keep reduction maintained while reduction maneuver can be paused. Fluoroscopic control in two planes. Replacement of the wires by distal angular stable screws with the help of the wires as an orientation. In case of insufficient reduction, reduction maneuver can be repeated while the first angular stable screw is locked. Final fluoroscopic control in two planes and ulnar deviation, eventually also in tangential view and clinical testing for stability of the distal radioulnar joint. Wound closure only by skin suture. Application of asterile dressing and apalmar cast. Arm consequently in upright position and active and complete movement of fingers. Palmar below-elbow cast for 2weeks, then movement of wrist without exertion. After regular radiographic control 4-5weeks postoperatively, increase of axial load to normal and, if needed, physiotherapy. Clinical control for irritation of tendons by plate or screws after 1year and eventual plate removal.

Open Reduction Maneuver for Distal Radius Fracture Involving an Intra-articular Sagittal Split

Open Reduction Maneuver for Distal Radius Fracture Involving an Intra-articular Sagittal Split

Is the 'safe zone' identified in preoperative computed tomography helpful for choosing optimal implant for fixation of radial head fracture?

The purpose of this study is to assess the clinical significance of the radiologic safe zone based on computed tomography and to compare the outcomes of three different implants for fixation of isolated radial head fractures. We retrospectively reviewed 367 patients who underwent internal fixation for isolated radial head fractures. We newly defined two subtypes of Mason type II fractures associated with the radiographic safe zone (IIA, two-part fracture allowing for safe fixation of plate; IIB, two-part fracture not allowing for safe fixation). 170 patients (CCS group, n = 82; HCS group, n = 31; plate group, n = 57) were investigated with no significant differences in demographics. The range of pronation and supination at 1 month postoperatively (P = 0.04 and P = 0.04) and the range of supination at 6 and 12 months postoperatively (P = 0.03 and P = 0.03) were significantly smaller in the plate group. In Mason type IIB fractures, the average MEPS was higher in the CCS and HSC groups than in the plate group (P = 0.01 and P = 0.02). And the average DASH score was lower in the CCS and HCS groups (P < 0.01 and P < 0.01). Evaluation of the radiologic safe zone is potentially helpful in selecting better surgical fixation option. For type III fractures, 2.3-mm cortical screws would be a better option than Acutrak screws. Plates would not be suitable for type IIB radial head fractures.

Effect of Camel Peptide on the Biofilm of Staphylococcus epidermidis and Staphylococcus haemolyticus Formed on Orthopedic Implants.

The increasing bacterial drug resistance and the associated challenges in the treatment of infections warrant the search for alternative therapeutic methods. Hope is placed in antimicrobial peptides, which have a broad spectrum of action and are effective against strains which are resistant to conventional antibiotics. Antimicrobial peptides are also tested for their efficacy in the treatment of infections associated with the formation of biofilm. The aim of the present study was to examine the effect of Camel peptide on S. epidermidis and S. haemolyticus adhesion to and formation of biofilm on steel cortical bone screws and also on the process of reducing mature biofilm in orthopedic implants. The tests were performed on steel implants for osteosynthesis. The MIC value and MBEC values of the peptide were determined using the microdilution method in microtiter plates. The effect of the peptide on adhesion and biofilm formation, as well as on the activity on the preformed biofilm, was evaluated using quantitative methods and confocal microscopy. The presented research results indicate that the peptide exhibits very good antimicrobial properties against the analyzed strains. Concentrations above MIC reduced biofilm in the range of 90-99%.

Low profile posterior lumbar-sacral interbody fusion for lumbosacral degenerative diseases: a technical note

BackgroundThe purpose of this study was to report our surgical experience in patients with lumbosacral degenerative diseases who underwent posterior decompression and interbody fusion fixed with cortical bone trajectory screw and sacral alar screw, which is known as low-profile posterior lumbosacral interbody fusion (LP-PLSIF).MethodsPatients with lumbosacral degenerative disease who underwent LP-PLSIF and traditional PLSIF (control group) internally fixed with pedicle screws were included retrospectively. Patients’ demographic data, operative parameters, and perioperative complications were recorded and analyzed.ResultsA total of 18 patients were enrolled in this study, which included 9 patients (5 male and 4 female) who underwent LP-PLSIF, and 9 patients (4 male and 5 female) who underwent traditional PLSIF. There wasn’t a significant difference in the average age between the two groups, 56.78 ± 10.92 years in the LP-PLSIF group and 60.22 ± 8.21 years in the PLSIF group (p = 0.460). The bone mineral density (BMD) of the two groups of patients were -2.00 ± 0.26 T and -2.13 ± 0.19 T, respectively (P = 0.239). The mean postoperative follow-up time was 12.7 months (range, 12–14 months). The mean operation time was 142.78 ± 11.21 min and 156.11 ± 13.41 min in the LP-PLSIF group and PLSIF group respectively (P < 0.05). The average blood loss was 137.78 ± 37.09 ml in the LP-PLSIF group, and 150.00 ± 27.84 ml in the PLSIF group (P = 0.441). The average postoperative drainage was 85.56 ± 37.45 ml and 122.22 ± 22.24 ml in the LP-PLSIF group and control group respectively (P < 0.05). Patients in the LP-PLSIF group had shorter incision length compared with the control group, 61.44 ± 10.56 mm vs. 74.56 ± 10.22 mm (P < 0.05). The average length of hospitalization of 11.33 ± 2.92 days in the LP-PLSIF group, and 11.11 ± 1.62 days in the PLSIF group (p = 0.844). All patients had significant improvement in VAS pain score, ODI, and JOA evaluation. However, patients in the LP-PLSIF group had better improvement in terms of VAS back pain and ODI in the short term after the operation. There were no neurological complications or wound infection. The fusion rate at the last follow-up was 100% (9 of 9) in the LP-PLSIF group, and 88.89% (8 of 9) in the control group based on CT scans. 1 patient in the control group had asymptomatic sacral pedicle screw loosening.ConclusionsLP-PLSIF is a safe and effective surgical technique for patients with lumbosacral degenerative disease, which has the potential strength of less invasive and better clinical improvement.

Adjunctive fixation of the humeral epicondyle in a lateral condylar fracture model: Ex vivo comparison of pins and plates with a novel composite (AdhFix).

To compare the biomechanical properties of using a novel composite construct (AdhFix) to an interfragmentary Kirschner wire or a reconstruction plate as adjunctive epicondylar stabilization in simulated lateral unicondylar humeral fractures. Cadaveric biomechanical assessment. Paired humeri harvested from skeletally mature dogs (14-41 kg), nine cadavers per group. Simulated lateral unicondylar humeral fractures were stabilized with a transcondylar 4.5 mm cortical screw placed in lag fashion. Adjunct fixations consisting of a novel composite incorporating 2.7 mm cortical screws on one side, and either a 2.7 mm reconstruction plate or a 1.6 mm Kirschner wire on the contralateral side, were tested within paired humeri. Repaired humeri were axially loaded to failure and construct stiffness, yield load, and ultimate load were obtained from the load-deformation curves. In pairwise comparison, yield load was significantly higher for AdhFix group compared to the pin group, p = .016. No statistical significance was seen in the comparison between AdhFix group and the plate group, p = .25. Adhfix was mechanically superior to K-wires, and comparable to plate fixation, for adjunctive fixation in a lateral humeral condylar model. Our results support further investigation of the novel composite for adjunct fracture fixation in lateral humeral condylar fractures. The novel composite tested may be a viable alternative for adjunct fixation of humeral condylar fractures, a technique that circumvents plate contouring.

A Crossed Screw Patellar Reconstruction Technique for the Treatment of the Severely Deficient Scaphoid Shaped Patella in Total Knee Arthroplasty

One of the contraindications to patella resurfacing in total knee arthroplasty is a thin and severely eroded ‘deficient’ patella. However, such patients often present with severe patellofemoral joint arthritis, patellar lateral subluxation, and patella maltracking, which can only be treated effectively with resurfacing. While various treatments have been proposed, options remain limited.Here we introduce a method of patella reconstruction using four 2.7-mm titanium cortical screws crossing each other into the inner shell of the patella. This provides a scaffold onto which bone cement and any standard polyethylene patellar component can be fixed. Postoperatively, the patient had no anterior knee pain, no patella maltracking, and no component loosening.Advantages of this technique include minimization of extensor disruption, low costs, easy accessibility, reproducibility, and improved mechanical strength.

Biomechanical evaluation of different posterior fixation techniques for treating thoracolumbar burst fractures of osteoporosis old patients: a finite element analysis.

Objective: To investigate the biomechanical characteristics of different posterior fixation techniques in treatment of osteoporotic thoracolumbar burst fractures by finite element analysis. Methods: The Dicom format images of T10-L5 segments were obtained from CT scanning of a volunteer, and transferred to the Geomagic Studio software, which was used to build digital models. L1 osteoporotic burst fracture and different posterior fixation techniques were simulated by SolidWorks software. The data of ROM, the maximum displacement of fixed segment, ROM of fractured L1 vertebrae, the stress on the screws and rods as well as on fractured L1 vertebrae under different movement conditions were collected and analysed by finite element analysis. Results: Among the four groups, the largest ROM of fixed segment, the maximum displacement of fixed segment and ROM of fractured vertebrae occurred in CBT, and the corresponding data was 1.3°, 2.57mm and 1.37°, respectively. While the smallest ROM of fixed segment, the maximum displacement of fixed segment and ROM of fractured vertebrae was found in LSPS, and the corresponding data was 0.92°, 2.46mm and 0.89°, respectively. The largest stress of screws was 390.97Mpa, appeared in CBT, and the largest stress of rods was 84.68MPa, appeared in LSPS. The stress concentrated at the junction area between the root screws and rods. The maximum stress on fractured vertebrae was 93.25MPa, appeared in CBT and the minimum stress was 56.68MPa, appeared in CAPS. And the stress of fractured vertebrae concentrated in the middle and posterior column of the fixed segment, especially in the posterior edge of the superior endplate. Conclusion: In this study, long-segment posterior fixation (LSPF) provided with the greatest stability of fixed segment after fixation, while cortical bone screw fixation (CBT) provided with the smallest stability. Cement-augmented pedicle screw-rod fixation (CAPS) and combined using cortical bone screw and pedicle screw fixation (CBT-PS) provided with the moderate stability. CBT-PS exhibited superiority in resistance of rotational torsion for using multiple connecting rods. CAPS and CBT-PS maybe biomechanically superior options for the surgical treatment of burst TL fractures in osteoporotic patients.

Biomechanical comparison of three fixation strategies for radial head fractures: a biomechanical study.

Second-generation headless compression screws (HCSs) are commonly used for the fixation of small bones and articular fractures. However, there is a lack of biomechanical data regarding the application of such screws to radial head fractures. This study evaluated the mechanical properties of the fixation of radial head fractures using asingle oblique HCS compared with those obtained using a standard locking radial head plate (LRHP) construct and a double cortical screw (DCS) construct. Radial synbone models were used for biomechanical tests of HCS, LRHP, and DCS constructs. All specimens were first cyclically loaded and then loaded to failure. The stiffness for the LRHP group was significantly higher than that for the other two groups, and that for the HCS group was significantly higher than that for the DCS group. The LRHP group had the greatest strength, followed by the HCS group and then the DCS group. The HCS construct demonstrated greater fixation strength than that of the commonly used cortical screws, although the plate group was the most stable. The present study revealed the feasibility of using a single oblique HCS, which has the advantages of being buried, requiring limited wound exposure, and having relatively easy operation, for treating simple radial head fractures.

Biomechanical effects of osteoporosis severity on the occurrence of proximal junctional kyphosis following long-segment posterior thoracolumbar fusion

BackgroundProximal junctional kyphosis is a common long-term complication in adult spinal deformity surgery that involves long-segment posterior spinal fusion. However, the underlying biomechanical mechanisms of the impact of osteoporosis on proximal junctional kyphosis remain unclear. The present study was to evaluate adjacent segment degeneration and spine mechanical instability in osteoporotic patients who underwent long-segment posterior thoracolumbar fusion. MethodsFinite element models of the thoracolumbar spine T1-L5 with posterior long-segment T8-L5 fusion under different degrees of osteoporosis were constructed to analyze intervertebral disc stress characterization, vertebrae mechanical transfer, and pedicle screw system loads during various motions. FindingsCompared with normal bone mass, the maximum von Mises stresses of T7 and T8 were increased by 20.32%, 22.38%, 44.69%, 4.49% and 29.48%, 17.84%, 40.95%, 3.20% during flexion, extension, lateral bending, and axial rotation in the mild osteoporosis model, and by 21.21%, 18.32%, 88.28%, 2.94% and 37.76%, 15.09%, 61.47%, −0.04% in severe osteoporosis model. The peak stresses among T6/T7, T7/T8, and T8/T9 discs were 14.77 MPa, 11.55 MPa, and 2.39 MPa under lateral bending conditions for the severe osteoporosis model, respectively. As the severity of osteoporosis increased, stress levels on SCR8 and SCR9 intensified during various movements. InterpretationOsteoporosis had an adverse effect on proximal junctional kyphosis. The stress levels in cortical bone, intervertebral discs and screws were increased with bone mass loss, which can easily lead to intervertebral disc degeneration, bone destruction as well as screw pullout. These factors have significantly affected or accelerated the occurrence of proximal junctional kyphosis.

Implant-associated fracture of the tibial plateau in cementless medial unicondylar knee prosthesis : Locking plate osteosynthesis

Cementless medial unicondylar knee prostheses with mobile inlays have proved to be successful and are increasingly being used worldwide; however, there is a risk of fracture of the medial tibial plateau in the postoperative healing phase. In most cases we observed split fractures starting from the keel of the implant. These can be treated with a small posteromedial locking plate, whereby the upper screws are inserted through the keel slot and then interlocked. This achieves an optimally strong bond between the implant and the screws and a stable construct. A longitudinal skin incision is made at the level of the keel slot. A radial T‑plate is placed subcutaneously. The plate is fixed with a lag screw in the middle section. The compression usually closes the fracture gap. Then three locking cortical bone screws are inserted through the keel slot in the transverse section of the plate. Distal fixation by locking or standard screws. Immediate pain-adapted partial weight bearing, unrestricted mobility. Healing of the fracture and full weight bearing mostly achieved after 4weeks.

Risk Factors of Proximal Screw Breakage of Locking Plate (ZPLP®) after MIPO for Distal Femur Fractures -Analysis of Patients with Plate Removal after Bony Union.

Locking a compression plate is a more favorable surgical technique than intramedullary nailing in the treatment of distal femur fractures. This study analyzed the risk factors of proximal screw breakage retrospectively, which was confirmed in the patients with plate removal after bony union. A total of 140 patients who were fixed by MIPO using ZPLP from 2009 to 2019 were identified. A total of 42 patients met the inclusion criteria and were included. The screw breakage group (12 patients) and the non-breakage group (30 patients) were compared. Approximately 12 (28.6%) of 42 plate-removal patients showed proximal screw breakage. The breakage of proximal screws developed at the junction of the screw head and neck. The number of broken proximal screws averaged 1.4 (1~4). The breakage of the proximal screw even after the bony union is more frequent in older patients (p = 0.023), the dominant side (p = 0.025), the use of the cortical screw as the proximal uppermost screw (p = 0.039), and the higher plate-screw density (p = 0.048). Advanced age, dominant side, use of the cortical screw as the uppermost screw, and higher plate-screw density were related to proximal screw breakage. When the plate is removed after bony union or delayed union is shown in these situations, the possibility of proximal screw breakage should be kept in mind.

Significant Early Loss of Correction in Modified Lapidus Compared to Original Lapidus for Hallux Valgus

Category: Bunion; Other Introduction/Purpose: The Lapidus procedure (first tarsometatarsal joint (TMT1) fusion) is an established treatment for correcting hallux valgus with 1st ray hypermobility. The original Lapidus (OL) technique involves fusing the TMT1 joint and first metatarsal base to the second, while the modified Lapidus (ML) technique involves fusing only the TMT1 joint. The purpose of this study was to investigate whether the ML procedure results in an early loss of correction. Methods: This retrospective study analyzed the outcomes of 45 feet in 40 patients with hallux valgus who underwent either the ML (21 feet) or OL (24 feet) procedure between 2014 and 2022 at a single center. All fixations were performed with 3.5 cortical screws, except for 9 cases that were fixed with a plantar locking plate. Differences in the immediate postoperative (6 weeks) and postoperative (6 months) intermetatarsal angle (IMA) and hallux valgus angle (HVA) were analyzed using Mann-Whitney tests, and complications were reported. Results: The mean preoperative IMA and HVA for the OL were 15.8° ± 3.5° and 36.4° ± 9.5°, respectively, and 14.5° ± 2.3° and 33.0° ± 7.0° for the ML. The immediate postoperative IMA and HVA were similar for both procedures (7.2° ± 2.0° and 7.7° ± 4.3° for OL, 7.3° ± 2.1° and 8.5° ± 5.5° for ML). Although from 6 weeks to 6 months postoperatively, the loss of correction of the HVA did not differ between both procedures (4.2° for OL, 5,6° for ML), the IMA loss of correction was significantly higher in the ML (1.1° ± 1.4° vs 0.5° ± 1.1°) (p &lt; 0.05). One case of delayed union was reported in the OL group, but it did not require revision. Conclusion: The study results suggest that the ML procedure does not provide the same stability as the OL procedure in the early postoperative period, as there was a significantly greater early loss of correction of the IMA at 6 months postoperatively in the ML group compared to the OL group. Although there were no differences in the loss of correction of the HVA angle (HVA), an observed loss of 5 degrees remains a concern. Further studies are necessary to better understand the indications of the modified and original procedures.

The accuracy of cortical bone trajectory screw placement guided by spinous process clamp hardware in lumbar spinal surgery: a retrospective study

This study aimed to assess the accuracy of cortical bone trajectory (CBT) screws placement guided by a spinous process clamp (SPC) guide. A total of 32 patients who received single-level midline lumbar fusion (MIDLF) surgery between June 2019 and January 2020 were retrospectively analyzed and divided into free-hand (FH) and SPC-guided groups according to the surgical approach. In the FH group, CBT screws was implanted with the assistance of fluoroscopy, while in the SPC group, CBT screws was implanted using the SPC navigator hardwire. A total of 128 screws were assessed in this study, with higher rates of clinically acceptable screw placement (grades A and B) and grade A screws in the SPC group than in the FH guide group (92.2% vs. 79.7%, P = 0.042 and 54.7% vs. 35.9%, P = 0.033, respectively). Misplacement screws (grades C, D, and E) occurred more often in the FH group than in the SPC guide group (20.3% vs. 7.8%, P = 0.042). The incidence of proximal facet joint violation (FJV) was higher in the FH group than in the SPC group (15.6% vs. 3.1%, P = 0.030). The radiation dose and time in the SPC guide group were comparable to those in the FH group (P = 0.063 and P = 0.078). The average operative time was significantly longer in the SPC guide group than in the FH group (267.8 ± 45.5 min vs. 210.9 ± 44.5 min, P = 0.001). Other clinical parameters, such as the average bone mineral density (BMD), intraoperative blood loss, and postoperative hospital stay, were not significantly different. Oswestry disability index (ODI) and back pain visual analogue scale (VAS) scores were significantly improved in both groups compared with preoperatively. SPC guided screw placement was more accurate than the fluoroscopy-assisted FH technique for single-level MIDLF at L4/5. Patients undergoing SPC-guided screw placement can achieve similar clinical outcomes as the fluoroscopy-assisted FH technique.