Screw Position Research Articles

Beyond 25 millimetres makes the difference: a prospective study on tip apex distance in dynamic hip screw treatment of intertrochanteric fractures

Background: The tip apex distance (TAD) is a key indicator of screw cut-out risk in dynamic hip screw (DHS) treatment for intertrochanteric fractures. This study sought to assess the prognostic significance of TAD in intertrochanteric fractures managed with DHS. Methods: This prospective observational study encompassed 50 patients with intertrochanteric fractures who had DHS fixing treatment. TAD was measured on postoperative radiographs. Patients were followed clinically and radiologically for a minimum of 3 months. The primary outcome was screw cut-out. Results: The mean TAD was 25.5 mm, with a range of 10 to 47 mm. Four screw cut-outs were seen, all in patients with TAD exceeding 35 mm. The mean TAD was 24.18 mm for successfully treated fractures, in contrast to 40.89 mm for those who experienced cut-out. No cut-outs were seen with TAD <25 mm. The inferior-central region of the femoral head was the predominant site for screw placement, occurring in 30% of cases. Conclusions: TAD is a dependable predictor of screw cut-out risk in DHS fixation of intertrochanteric fractures. Maintaining a TAD <25 mm and screw position in the inferior-central zone of the femoral head may help minimize cut-out risk. Surgeons should aim for proper screw placement and consider TAD when treating these fractures.

Efficacy comparison of robot-assisted versus freehand fluoroscopy-assisted minimally invasive transforaminal lumbar interbody fusion for degenerative lumbar spinal diseases

Objective: To compare the clinical and radiographic outcomes between robot-assisted minimally invasive transforaminal lumbar interbody fusion (RA MIS-TLIF) and fluoroscopy-assisted MIS-TLIF (FA MIS-TLIF) in patients with degenerative lumbar spinal diseases. Methods: The clinical data of 114 patients with lumbar degenerative diseases who underwent MIS-TLIF in Qilu Hospital of Shandong University from January 2019 to March 2022 were analyzed retrospectively. Fifty-eight patients underwent RA MIS-TLIF (robot group) and 56 patients received FA MIS-TLIF (freehand group). There were 16 males and 42 females in the robot group, with a mean age of (56.7±8.1) years. And there were 19 males and 37 females in the freehand group, with a mean age of (57.2±8.6) years. The clinical outcome parameters were the visual analog scale (VAS) of pain, Oswestry Disability Index (ODI) score, operative time, number of intraoperative fluoroscopies, blood loss, postoperative hospital stay and complications. The radiographic change measures were the accuracy of screw placement, facet joint violation (FJV), fusion status, and change in disc height at the proximal adjacent segment. All the patients were followed-up for 2-5 years. Results: There was no significant differences in the VAS and ODI scores, blood loss, or postoperative hospital stay between the two groups (all P>0.05). The operative time was longer in robot group than freehand group [(158.5±12.1) min vs (146.4±15.4) min, P<0.001]. There was no significant difference in the number of intraoperative fluoroscopies for patients between robot group and freehand group (P>0.05). The number of intraoperative fluoroscopies for the surgeon was significantly lower in robot group than freehand group (13.8±3.9 vs 74.7±6.8, P<0.001). The rate of a perfect screw position (grade A) was higher in robot group than freehand group [87.5%(203/232) vs 70.1%(157/224), P<0.001]. However, there was no significant difference in the proportion of clinically acceptable screws (grades A and B) between the two groups [98.3%(228/232) vs 96.9%(217/224), P=0.330]. The FJV grade was significantly higher in freehand group than robot group (0.43±0.68 vs 0.13±0.43, P<0.001). During at 2-year postoperative follow-up, there was no significant difference in the fusion status between the two groups (P>0.05); however, the decrease in disc height at the proximal adjacent segment was significantly less in robot group than freehand group [(0.63±0.38) mm vs (0.92±0.35) mm, P=0.001]. In the robotic group, a pedicle screw penetrated the outer wall of the vertebral pedicle in one patient, which was adjusted during surgery. In the freehand group, two screws were inserted too deeply and penetrated the anterior cortex, resulting in mild abdominal discomfort postoperatively, which resolved by the third day after surgery. Conclusions: Robot-assisted percutaneous pedicle screw placement is a safer and more accurate alternative to conventional freehand fluoroscopy-assisted pedicle screw insertion in MIS-TLIF. Compared with freehand MIS-TLIF, robot-assisted MIS-TLIF increases the operation time, but the accuracy of screw placement is higher, and the intraoperative radiation dose and the degree of adjacent segment degeneration are reduced.

Stabilization of 82 sacroiliac luxations in 67 cats using two sacroiliac screws (2014-2023).

To describe sacroiliac luxation stabilization in cats using two screws and to report clinical and radiographic short-term outcomes. Retrospective clinical cohort study. Cats (n = 67) with sacroiliac luxation. Case records of cats presented for sacroiliac luxation stabilized using two screws per side affected, one lag and one positional, between 2014 and 2023 were reviewed. The percentage of sacral purchase (PoSP) for each screw, percentage of reduction (PoR), and pelvic canal width ratio (PCWR) were measured and calculated. Eighty-two sacroiliac luxations were stabilized. Two 2.0 mm screws were used in 69 cases; two 2.4-mm screws in nine cases, and one 2.4 mm with one 2.0 mm screw in four cases. The mean PoSPs for lag and positional screws were 46% ± 12 and 31% ± 11, respectively. The median PoR was 89% (41 to 100). The mean PCWR was 1.23 ± 0.11. Clinical follow up was available for 42 cats with 53 sacroiliac luxations at a median of 87 days (36 to 2503). The full function was noted in 34 patients (81%). Screw failure occurred in five sacroiliac joints (4.7%), including loosening (n = 3), and breakage (n = 2) of the positional screws (n = 1). Pelvic canal diameter was maintained in all cases. Excellent functional and radiographic outcomes were obtained for cats with sacroiliac luxation stabilized with two sacroiliac screws. Feline sacroiliac luxation can be stabilized using two sacroiliac screws.

Biomechanical comparison of Gofried positive support reduction of Pauwels type III femoral neck fractures: A finite elements analysis

ObjectiveThis study aims to investigate the biomechanical characteristics of non-anatomical reduction and different screw positions on the stability of Pauwels type III femoral neck fractures. MethodsThree-dimensional finite element models of femoral neck fractures were constructed using CT images. Four types of internal fixation methods were simulated, including biplane double-supported screw fixation (BDSF), three inverted triangular parallel cannulated screws (3CS), new parallel cannulated screws with posterior screws moving down (New 3CS), and two parallel cannulated screws (2CS). von Mises stress and total displacement were compared between the fracture models after the femoral head was subjected to an axial load of 2100 N. Stress and displacement data for the implants and the femur were recorded for each fixation method and compared. ResultsThe results demonstrated that positive reduction of a Pauwels type III femoral neck fracture provided greater stability than neutral or negative reduction. Specifically, the BDSF group showed the lowest maximum von Mises stress in the femur (17.66 MPa) in positive reduction, compared to 3CS (21.08 MPa), New 3CS (22.14 MPa), and 2CS (36.57 MPa). The total displacement of positive reduction in the BDSF group was 0.3143 mm, which was lower than in the 3CS (0.3498 mm), New 3CS (0.3343 mm), and 2CS (0.4533 mm) groups. The stress distribution in the positive support reduction group was lower than that of the other groups, indicating better load distribution. Among the three-screw fixation methods, the New 3CS system exhibited the highest stress in the screws (with a peak of 28.62 MPa), while the 2CS group displayed the highest stresses overall, both in the femur and the screws. ConclusionFor Pauwels type III femoral neck fractures, a positive support reduction with BDSF fixation exhibited superior biomechanical performance than negative reduction. Based on the finite element analysis conducted in this study, the positive support reduction with BDSF fixation can enhance fixation stability, suggesting that non-anatomical reduction is recommended.

Improving surgical technical skills for emergency fixation of unstable pelvic ring fractures: an experimental study using a pelvic ring fracture simulator

BackgroundThe management of hemodynamically unstable pelvic ring injuries necessitates surgical intervention, often involving procedures such as external fixation and percutaneous screw placement. Given the infrequent performance of these procedures, regular training is imperative to ensure readiness for emergencies. Our pre- post simulation study aimed to adapt and validate a realistic simulation model for stabilizing unstable pelvic ring injuries, facilitating participants’ knowledge retention and procedural confidence enhancement.MethodsA standardized simulator of an unstable pelvic ring utilizing synthetic pelvic bones featuring complete disruption of the symphysis and sacroiliac joint was developed. Trauma surgeons of a level one academic hospital were invited to perform external fixation and emergency sacroiliac screw application under C-arm guidance. Prior to and following the simulation session, participants completed a subjective questionnaire assessing their confidence in emergency interventions on a 10-point Likert scale (10-LS). Objective parameters, such as intraoperative imaging quality, reduction accuracy, and the positioning of screws, wires, and external fixators, were also evaluated as secondary outcome measures.ResultsFifteen trauma surgeons (10 residents, 5 consultants) participated in the simulation over the course of one day. The mean total operation time was 20.34 ± 6.06 min, without significant differences between consultants and residents (p = 0.604). The confidence for emergency SI-Screw placement increased significantly after the simulator (10-LS: Before = 3.8 ± 3.08 vs. After = 5.67 ± 2.35; p = 0.002) as well as after external fixation (10-LS: Before = 3.93 ± 2.79 vs. After = 6.07 ± 2.52; p = 0.002). In addition, confidence in (intraoperative) pelvic imaging increased significantly (10-LS: Before = 4.60 ± 3.0 vs. After = 6.53 ± 2.39; p = 0.011). Overall, the model was rated as a realistic simulation of clinical practice (10-LS = 7.87 ± 1.13).ConclusionsOur unstable pelvis fracture model is a tool to practice emergency interventions such as external fixation and percutaneous techniques. Participants benefitted from this in terms of technical instrumentation as well as intraoperative imaging. Further studies are required to validate the objective benefits and improvements that participants undergo through frequent training.

Semi-automated finite element analyses of surgically treated acetabular fractures to investigate the biomechanical behaviour of patient-specific compared to conventional implants

BackgroundIn acetabular fracture surgery, understanding the biomechanical behaviour of fractures and implants is beneficial for clinical decision-making about implant selection and postoperative (early) weightbearing protocols. This study outlines a novel approach for creating finite element models (FEA) from actual clinical cases. Our objectives were to (1) create a detailed semi-automatic three-dimensional FEA of a patient with a transverse posterior wall acetabular fracture and (2) biomechanically compare patient-specific implants with manually bent off-the-shelf implants.MethodsA computational study was performed in which we developed three finite element models. The models were derived from clinical imaging data of a 20-year-old male with a transverse posterior wall acetabular fracture treated with a patient-specific implant. This implant was designed to fit the patient's anatomy and fracture configuration, allowing for optimal placement and predetermined screw trajectories. The three FEA models included an intact hemipelvis for baseline comparison, one with a fracture fixated with a patient-specific implant, and another with a conventional implant. Two loading conditions were investigated: standing up and peak walking forces. Von Mises stress and displacement patterns in bone, implants and screws were analysed to assess the biomechanical behaviour of fracture fixation with either a patient-specific versus a conventional implant.ResultsThe finite element models demonstrated that for a transverse posterior wall type fracture, a patient-specific implant resulted in lower peak stresses in the bone (30 MPa and 56 MPa) in standing-up and peak walking scenario, respectively, compared to the conventional implant model (46 MPa and 90 MPa). The results suggested that patient-specific implant could safely withstand standing-up and walking after surgery, with maximum von Mises stresses in the implant of 156 MPa and 371 MPa, respectively. The results from the conventional implant indicate a likelihood of implant failure, with von Mises stresses in the implant (499 MPa and 1000 MPa) exceeding the yield stress of stainless steel.ConclusionThis study presents a workflow for conducting finite element analysis of real clinical cases in acetabular fracture surgery. This concept of personalized biomechanical fracture and implant assessment can eventually be applied in clinical settings to guide implant selection, compare conventional implants with innovative patient-specific ones, optimizing implant designs (including shape, size, materials, screw positions), and determine whether immediate full weight-bearing can be safely permitted.

Understanding the mechanism of injury and fracture pattern of paediatric triplane ankle fractures versus adult trimalleolar fractures.

Paediatric triplane fractures and adult trimalleolar ankle fractures both arise from a supination external rotation injury. By relating the experience of adult to paediatric fractures, clarification has been sought on the sequence of injury, ligament involvement, and fracture pattern of triplane fractures. This study explores the similarities between triplane and trimalleolar fractures for each stage of the Lauge-Hansen classification, with the aim of aiding reduction and fixation techniques. Imaging data of 83 paediatric patients with triplane fractures and 100 adult patients with trimalleolar fractures were collected, and their fracture morphology was compared using fracture maps. Visual fracture maps were assessed, classified, and compared with each other, to establish the progression of injury according to the Lauge-Hansen classification. Four stages of injury in triplane fractures, resembling the adult supination external rotation Lauge-Hansen stages, were observed. Stage I consists of rupture of the anterior syndesmosis or small avulsion of the anterolateral tibia in trimalleolar fractures, and the avulsion of a larger Tillaux fragment in triplanes. Stage II is defined as oblique fracturing of the fibula at the level of the syndesmosis, present in all trimalleolar fractures and in 30% (25/83) of triplane fractures. Stage III is the fracturing of the posterior malleolus. In trimalleolar fractures, the different Haraguchi types can be discerned. In triplane fractures, the delineation of the posterior fragment has a wave-like shape, which is part of the characteristic Y-pattern of triplane fractures, originating from the Tillaux fragment. Stage IV represents a fracture of the medial malleolus, which is highly variable in both the trimalleolar and triplane fractures. The paediatric triplane and adult trimalleolar fractures share common features according to the Lauge-Hansen classification. This highlights that the adolescent injury arises from a combination of ligament traction and a growth plate in the process of closing. With this knowledge, a specific sequence of reduction and optimal screw positions are recommended.

Clinical and radiological evaluation of the Bristow–Latarjet procedure in patients with 30 or more years of follow-up

BackgroundThe Bristow-Latarjet surgery is the procedure most performed for recurrent anterior shoulder dislocation. There are few studies with a follow-up of more than 20 years. Because it is a nonanatomical technique, there is interest in knowing the clinical and radiological results and the rates of complications in the long term. MethodsWe performed a retrospective case series study. Patients with recurrent anterior dislocation of the shoulder who underwent the Bristow-Latarjet procedure were included and followed-up clinically for at least 30 years. We evaluated clinical scores - the Rowe, Western Ontario Shoulder Instability (WOSI), Single Assessment Numeric Evaluation (SANE), visual analog scale (VAS) – as well as clinical outcomes: the relapse (dislocation or subluxation) and seizure. Screw and graft positioning were assessed by computed tomography (CT), the degree of arthropathy by radiography, and subscapularis fatty degeneration as rotator cuff tears by magnetic resonance imaging (MRI). Both clinical scores and imaging were obtained at 30 years of surgery. ResultsTwenty-seven patients (30 shoulders) were evaluated, with a mean follow-up of 35±4.5 years. The scores obtained were 88.28±15.9 by Rowe, 208±244.2 by the WOSI examination, 92.5%±10.4% by the SANE and 0.45±1.3 by the VAS. The recurrence rate was 13.3%, with all patients presenting subluxations and no new dislocations. All grafts were positioned below the glenoid equator. In 82.4% of the cases, the grafts were aligned with the articular surface, 5.9% were medially deviated, and 11.8% were laterally deviated. Consolidation occurred in 76.5% of the cases. The screws presented bicortical fixation in 76.5% of the shoulders and inclination in the axial plane of less than 15° in 64.7%. A total of 58.8% of the cases presented with glenohumeral arthropathy, and 75% of the MRIs showed the absence of fatty degeneration. ConclusionBristow–Latarjet surgery demonstrates excellent clinical results in most patients after 30 years of follow-up. The recurrence rate is low, as is the complication rate. Glenohumeral arthropathy occurs in most patients without significant clinical repercussions.

A Retrospective Study of Risk Factors Associated with Refracture after Repair of Radial-Ulnar Fractures in Small-Breed Dogs.

The aim of this study was to identify risk factors for refracture after radial union in small-breed dogs. In our retrospective study, medical records of radial-ulnar fracture cases in small dogs treated with plates and screws were reviewed. General information and postoperative course (days until confirmed radial fracture healing, with or without ulnar union, time to final follow-up, with or without plate removal and refracture) were recorded. The fracture line location, screw positions, radial thickness and width, and pixel values throughout the postoperative periods were obtained from the radiographs. The affected limbs were classified into non-plate removal (P) and plate removal (R) groups. Refracture occurred in 5 of the 141 limbs at the most distal screw in the P group and 5 of the 40 limbs at the same site as the initial fracture in the R group. Multivariate analysis indicated that refracture was linked to the amount of relative change with growth in the position of the most distal screw in the P group, with pixel value and radial thickness ratios at the same site as the initial fracture in the R group. Reducing the screw diameter relative to the radial width to the appropriate extent may be considered in cases where the screw positioned at the most distal end of the radius is expected to be relatively proximal as the distal radius grows; not removing the plate may be considered in cases with a decreased radial thickness or bone mineral density beneath the plate during plate removal.

High Accuracy of Three-Dimensional Navigated Kirschner-Wire-Less Single-Step Pedicle Screw System (SSPSS) in Lumbar Fusions: Comparison of Intraoperatively Planned versus Final Screw Position.

(1) Background: Our team has previously introduced the Single-Step Pedicle Screw System (SSPSS), which eliminates the need for K-wires, as a safe and effective method for percutaneous minimally invasive spine (MIS) pedicle screw placement. Despite this, there are ongoing concerns about the reliability and accuracy of screw placement in MIS procedures without traditional tools like K-wires and Jamshidi needles. To address these concerns, we evaluated the accuracy of the SSPSS workflow by comparing the planned intraoperative screw trajectories with the final screw positions. Traditionally, screw placement accuracy has been assessed by grading the final screw position using postoperative CT scans. (2) Methods: We conducted a retrospective review of patients who underwent lumbar interbody fusion, using intraoperative 3D navigation for screw placement. The planned screw trajectories were saved in the navigation system during each procedure, and postoperative CT scans were used to evaluate the implanted screws. Accuracy was assessed by comparing the Gertzbein and Robbins classification scores of the planned trajectories and the final screw positions. Accuracy was defined as a final screw position matching the classification of the planned trajectory. (3) Results: Out of 206 screws, 196 (95%) were accurately placed, with no recorded complications. (4) Conclusions: The SSPSS workflow, even without K-wires and other traditional instruments, facilitates accurate and reliable pedicle screw placement.

Effect of the cone-beam CT acquisition trajectory on image quality in spine surgery: experimental cadaver study

BACKGROUNDIntraoperative 3D imaging with cone-beam CT (CBCT) improves assessment of implant position and reduces complications in spine surgery. It is also used for image-guided surgical techniques, resulting in improved quality of care. However, in some cases, metal artifacts can reduce image quality and make it difficult to assess pedicle screw position and reduction. PURPOSEThe objective of this study was to investigate whether a change in CBCT acquisition trajectory in relation to pedicle screw position during dorsal instrumentation can reduce metal artifacts and consequently improve image quality and clinical assessability. STUDY DESIGNExperimental cadaver study. METHODSA human cadaver was instrumented with pedicle screws in the thoracic and lumbar spine region (Th11 to L5). Then, the acquisition trajectory of the CBCT (Cios Spin, Siemens, Germany) to the pedicle screws was systematically changed in 5° steps in angulation (−30° to +30°) and swivel (−25° to +25°). Subsequently, radiological evaluation was performed by 3 blinded, qualified raters on image quality using 9 questions (including anatomical structures, implant position, appearance of artifacts) with a score (1–5 points). For statistical evaluation, the image quality of the different acquisition trajectories was compared to the standard acquisition trajectory and checked for significant differences. RESULTSThe angulated acquisition trajectory significantly increased the score for subjective image quality (p<.001) as well as the clinical assessability of pedicle screw position (p<.001) with particularly strong effects on subjective image quality in the vertebral pedicle region (d=1.61). Swivel of the acquisition trajectory significantly improved all queried domains of subjective image quality (p<.001) as well as clinical assessability of pedicle screw position (p<.001). CONCLUSIONSIn this cadaver study, the angulation as well as the swivel of the acquisition trajectory led to a significantly improved image quality in intraoperative 3D imaging (CBCT) with a constant isocenter. The data show that maximizing the angulation/swivel angle towards 30°/25° provides the best tested subjective image quality and enhances clinical assessability. Therefore, a correct adjustment of the acquisition trajectory can help to make intraoperative revision decisions more reliably. CLINICAL SIGNIFICANCEThe knowledge of enhanced image quality by changing the acquisition trajectory in intraoperative 3D imaging can be used for the assessment of critical screw positions in spine surgery. The implementation of this knowledge requires only a minor change of the current intraoperative imaging workflow without additional technical equipment and could further reduce the need for revision surgery.

Are positional screws superior to lag screws in fixation of medial malleolar fractures? A randomized controlled trial.

There is no consensus about the best fixation method for medial malleolar fractures. This study was conducted to compare the clinical and radiological results of positional (fully threaded) screws and lag (partially threaded) screws when used to fix medial malleolar fractures. This prospective, randomized clinical trial included 68 patients with closed isolated medial malleolar fractures. Each study arm included 34 patients who were randomly treated with either fully threaded screws (FT group) or partially threaded screws (PT group). Patients were evaluated radiologically for union and clinically using the American Orthopaedic Foot and Ankle Society (AOFAS) ankle hindfoot score. After a 12-month follow-up, the mean AOFAS ankle hindfoot score was 92.1 ± 3.5 in the FT group and 91.8 ± 5.4 in the PT group. Union was achieved in the FT group after a mean of 6.2 ± 1.3 weeks and after a mean of 6.5 ± 1.5 weeks in the PT group. Both fully threaded and partially threaded screws yielded good comparable clinical and radiological outcomes when used to fix isolated medial malleolar fractures.

Preliminary comparative study of spinal robot-assisted pedicle screw placement using different surgical approaches

To compare the effectiveness of spinal robot-assisted pedicle screw placement through different surgical approaches and to guide the clinical selection of appropriate robot-assisted surgical approaches. The clinical data of 14 patients with thoracolumbar vertebral diseases who met the selection criteria between January 2023 and August 2023 were retrospectively analyzed, and all of them underwent pedicle screw placement under assistant of the Mazor X spinal surgery robot through different surgical approaches. The patients were divided into posterior median approach (PMA) group ( n=6) and intermuscular approach (IMA) group ( n=8) according to the surgical approaches, and there was no significant difference in age, gender, body mass index, disease type, and fixed segment between the two groups ( P>0.05). The operation time, intraoperative blood loss, screw-related complications, and reoperation rate were recorded and compared between the two groups; the inclination angle of the screw, the distance between the screw and the midline, and the caudal inclination angle of the screw were measured based on X-ray films at immediate after operation. There was no significant difference in operation time and intraoperative blood loss between the two groups ( P>0.05). There was no screw-related complication such as nerve injury in both groups, and no patients underwent secondary surgery. At immediate after operation, the inclination angle of the screw, the distance between the screw and the midline, and the caudal inclination angle of the screw in the IMA group were significantly greater than those in the PMA group ( P<0.05). There are differences in the position and inclination angle of screws placed with robot-assisted surgery through different surgical approaches, which may be due to the obstruction of the screw path by soft tissues such as skin and muscles. When using spinal robot-assisted surgery, selecting the appropriate surgical approach for different diseases can make the treatment more reasonable and effective.

Direct anterior bone block grafting for treatment of bone defects and dysplasia of the coronoid process

The aim of the surgery was to treat an elbow instability caused by critical coronoid bone loss (CCBL), lateral ulnar collateral ligament (LUCL) insufficiency,and general hyperlaxity by performing adirect anterior coronoid bone graft (CBG) and LUCL reconstruction in the same setting. In cases with CCBL isolated ligament reconstruction harbors ahigh failure rate, necessitating supplementary bony procedures. The diagnosis of CCBL is confirmed through lateral radiographs and further quantified through computed tomography (CT) imaging. Objective assessment of instability is conducted with standardized arthroscopic tests. Performing an anterior approach for CBG offers distinct advantages, notably in terms of achieving precise positioning of plates and screws and providing access to the proximal radioulnar joint. Usual contraindications to surgery, coronoid bone loss less than 40%. The surgical procedure is thoroughly illustrated with avideo of the operation that can be accessed online: reconstruction of the LUCL with asemitendinosus allograft, harvesting of the graft from the iliac crest, exposure of the coronoid process with adirect anterior approach, freshening up of the graft bed. Temporary fixation of the graft with aKirschner wire. Assessment of joint congruency, stability and range of motion (ROM) prior to definitive fixation with a2.4 mm buttress plate and screws. Nonsteroidal anti-inflammatory drugs (NSAID) to prevent heterotopic ossification. Elbow mobilization in pronation from day1 with an overhead motion protocol. Removable splint for 4weeks, free mobilization at 6weeks, return to sport at 3months. Durable elbow stability was achieved along with free ROM and high patient satisfaction.

Acetabular posterior column screws via an anterior approach.

Screw fixation of acetabular column fractures is a well-established alternative option to plate fixation providing comparable biomechanical strength and requiring less surgical exposure. For displaced acetabular fractures involving both columns open reduction and plate fixation of one column in combination with a column-crossing screw fixation of the opposite column via a single approach is a viable treatment option. Preoperative planning of posterior column screws (PCS) via an anterior approach is mandatory to assess the eligibility of the fracture for this technique and to plan the entry point and the screw trajectory. The intraoperative application requires fluoroscopic guidance using several views. A single view showing an extraarticular screw position is adequate to rule out hip joint penetration. The fluoroscopic assessment of cortical perforation of the posterior column requires several oblique views such as lateral oblique views, obturator oblique views and axial views of the posterior column or alternatively intraoperative CT scans. The application of PCS via an anterior approach is a technically demanding procedure, that allows for a relevant reduction of approach-related morbidity, surgical time and blood loss by using a single approach.

Pedicle screw placement in the cervical vertebrae using augmented reality-head mounted displays: a cadaveric proof-of-concept study

BackgroundThe accurate and safe positioning of cervical pedicle screws is crucial. While augmented reality (AR) use in spine surgery has previously demonstrated clinical utility in the thoracolumbar spine, its technical feasibility in the cervical spine remains less explored. PurposeThe objective of this study was to assess the precision and safety of AR-assisted pedicle screw placement in the cervical spine. Study DesignIn this experimental study, 5 cadaveric cervical spine models were instrumented from C3 to C7 by 5 different spine surgeons. The navigation accuracy and clinical screw accuracy were evaluated. MethodsPostprocedural CT scans were evaluated for clinical accuracy by 2 independent neuroradiologists using the Gertzbein-Robbins scale. Technical precision was assessed by calculating the angular trajectory (°) and linear screw tip (mm) deviations in the axial and sagittal planes from the virtual pedicle screw position as recorded by the AR-guided platform during the procedure compared to the actual pedicle screw position derived from postprocedural imaging. ResultsA total of forty-one pedicle screws were placed in 5 cervical cadavers, with each of the 5 surgeons navigating at least 7 screws. Gertzbein-Robbins grade of A or B was achieved in 100% of cases. The mean values for tip and trajectory errors in the axial and sagittal planes between the virtual versus actual position of the screws was less than 3 mm and 30°, respectively (p<.05). None of the cervical screws violated the cortex by more than 2 mm or displaced neurovascular structures. ConclusionsAR-assisted cervical pedicle screw placement in cadavers demonstrated clinical accuracy comparable to existing literature values for image-guided navigation methods for the cervical spine. Clinical SignificanceThis study provides technical and clinical accuracy data that supports clinical trialing of AR-assisted subaxial cervical pedicle screw placement.

Investigation of the Usefulness of Implants With Locking Mechanisms for Diffuse Idiopathic Skeletal Hyperostosis (DISH)-Induced Thoracic and Lumbar Fractures in Patients Operated in the Prone Position.

Background Diffuse idiopathic skeletal hyperostosis (DISH) is a disease that causes bone growth in the spine and musculoskeletal system, and even minor trauma can cause fractures that often require surgery. DISH-induced fractures show a tendency for bone loss when operated in the prone position, which can lead to poor fusion and implant failure; therefore, surgery in the lateral recumbent position is often recommended. However, inserting a pedicle screw (PS) in the lateral recumbent position is technically difficult. This study examined the effectiveness of the repair and fixation of thoracic and lumbar spine fractures using implants with locking mechanisms in the prone position in patients with DISH. Methods We retrospectively analyzed the data from 11 patients (six males and five females; mean age: 87 years) who underwent surgery for thoracic and lumbar fractures caused by DISH between December 2023 and June 2024. Surgery was performed in the prone position using PSs or transdiscal screws (TSDs) for DISH. Ennovate® implants manufactured by B-BRAUN were used. The fixed range was three above-three below for PSs and two above-two below for TSDs. The evaluation parameters were the height/level of injury, operative time, blood loss, local kyphosis angle, anterior wall height ratio, and complications. The local kyphosis angle was measured as the angle between the upper and lower endplates of the fractured vertebrae. The ratio of the anterior wall height was evaluated. Results The average operative time was 87 min (52-172 min), and the average blood loss was 40ml (10-140 ml). The preoperative and postoperative local kyphosis angle was -8.7° and -2.4°, respectively, and the average local kyphosis angle improvement was 6.3° (0.1-14°). The preoperative and postoperative anterior wall height ratio was 132% and 110%, respectively, and the average anterior wall height ratio improvement was 22% (2-82%). No complications, such as screw deviation, implant loosening, loss of correction, or skin problems, were observed. Conclusion This study demonstrated that DISH-induced thoracic and lumbar spine fractures could be repaired and fixed using implants with locking mechanisms in the prone position. The prone position is familiar to spine surgeons and is considered safe. Additionally, screw migration may occur due to decreased bone density in the vertebral bodies with DISH; in such cases, it would be better to fix the screw without forcing it to be repositioned.

Open Management of condylar head fractures: The first 50 cases: what have we learnt and where are we going?

This study evaluates a single surgeon’s experience the development of a practice in open treatment of intracapsular condylar fractures over three years at a tertiary maxillofacial trauma center. Enhanced dynamic peer reviewed longitudinal audit in keeping with adoption of elements of new clinical practice was instituted. This aimed to record and analyze clinical and functional outcomes at both surgeon and patient level. A retrospective review of patients treated for AOCMF-classified intracapsular fractures was conducted, utilizing an extended pre-auricular approach and positional screw fixation, with an emphasis on early joint mobilization and physiotherapy. The cohort consisted of 45 patients with 50 fractures, exhibiting a mean postoperative mouth opening of 32 mm, which statistically increased over time. Patient satisfaction was high, and the majority of radiological outcomes were deemed anatomical.In the patient cohort there were no permanent facial nerve injuries. Other postoperative complications were minimal, including one Frey’s syndrome and a 16% re-intervention rate primarily for hardware removal.The findings suggest that open treatment can be provided to achieve satisfactory early function as part of implementing an in-part novel procedure. The paper provides insight into establishing a new technique in both experiential and governance domains, as well as lessons learned. The high levels of patient and surgeon satisfaction confirm increasing levels of evidence supporting open reduction and fixation in these challenging injuries yet the study’s limitations include the absence of a control group and the potential non- generalizability due to the single-surgeon perspective. The study highlights the need to support colleagues providing this treatment and establish a national mentoring program to achieve this. At this point Long-term studies and a multi- center trial would follow to develop are suggested for a comprehensive understanding of the treatment’s efficacy and formal development of management protocols.

The effect of screw insertion configuration of Sinus Tarsi plate on biomechanical performance using finite element analysis

Sinus Tarsi plates are used as implants for minimally invasive surgery of calcaneus bone fractures. This study evaluated the screw fixation patterns of Sinus Tarsi plates for optimal biomechanical performance. Six three-dimensional (3D) finite element models with different positional screws were evaluated for calcaneus fracture stabilization using Sinus Tarsi plates with 5, 6, and 7 holes. Walking stance conditions as heel strike, midstance, and push-off phases were used to compare loading. Results indicated that the equivalent (EQV) stress exhibited in the implant was higher than in the surrounding bone, with the highest value during the push-off phase. The maximum EQV stress or risk of failure decreased when an insertion screw was placed in the anterior bone using a 7-hole plate, and the most stable strain result at the fracture bone site was recorded for a Sinus Tarsi plate with 7 holes (TT 7-1). The screw insertion pattern and configuration of the Sinus Tarsi plate impacted the biomechanical performance of the calcaneal fracture.

Combination of Anatomical Plates and Rotator Cuff Reinforcement for Minimally Invasive Treatment of Greater Tuberosity Fractures of the Humerus.

Greater tuberosity fractures of the humerus can be challenging to manage due to their complex anatomy and the potential for compromised shoulder function. We present a novel technique for treating greater tuberosity fractures utilizing specialized anatomical plates and rotator cuff reinforcement. The technique involves the use of an anatomically T-shaped plate designed specifically for the greater tuberosity region of the humerus, allowing for precise fixation and stability. Additionally, rotator cuff reinforcement is performed using sutures to enhance structural integrity and promote early mobilization. The simplified process is as follows: After administering anesthesia, a 3 cm incision is made along the lateral aspect of the shoulder to precisely expose the fracture site of the greater tuberosity. A suture of size 5 is skillfully threaded through the tough rotator cuff tendon to securely attach the proximal humerus to the anatomical plate after the greater tuberosity has been reduced. Intraoperative fluoroscopy is utilized to verify the accurate positioning of plates and screws. After ensuring everything is correct, the surgery concludes.