Distal Fragment Research Articles

Participation of retroelements in chromoanagenesis in cancer development

Purpose of the study: to determine the role of retroelements in chromoanagenesis mechanisms in cancer etiopathogenesis.Material and Methods. The search for relevant sources was carried out in the Scopus, Web of Science, PubMed, Elibrary systems, including publications from February 2002 to December 2023. Of the 864 scientifc articles found, 60 were used to write a systematic review.Results. According to original works and meta-analyses results, the cause of complex chromosomal rearrangements during cancer development may be retroelement pathological activation. Chromoanagenesis involves LINE1, SVA, Alu, HERV, which cause double-stranded DNA breaks, insertions in tumor suppressor genes region, the formation of chimeric oncogenes due to retroelement use as new promoters, and function as molecular “band-aids” in non-homologous end junctions and form bridges of distal DNA fragments. Global structural rearrangements of chromosomes observed during chromoanagenesis may be consequences of retroelements activation, which participate in non-allelic homologous recombination and in microhomology-mediated joining of ends characteristic. Certain types of neoplasms, such as colon cancer, are characterized by both high levels of chromothripsis and retroelement activity. In head and neck squamous cell carcinoma, chromoplexy is specifc, the sources of sequences at the breakpoints of which are retroelements. During chromoanagenesis, activation of proto-oncogenes and inactivation of tumor suppressor genes are observed, which is also a consequence of retroelement activation. This is due to the presence of retroelement sequences in proto-oncogenes promoter regions and introns (which become the basis for chimeric oncogene formation) and hot spots of insertional mutagenesis in tumor suppressor genes (transpositions into these regions inactivate these genes).Conclusion. The results obtained on the driver effect of retroelements in chromothripsis, chromoplexy and chromoanasynthesis mechanisms, which are the basis for the formation of clonal evolution of tumors, indicate promise of targeted therapy aimed at silencing the activity of retroelements in cancer patients treatment. For this purpose, it is possible to use microRNAs complementary to retroelements, which are also involved in tumor development, as tools.

Osteosynthesis using Scorpion plate for neer type V distal clavicle fracture.

Neer type V distal clavicle fractures are considered the most unstable fracture type and are characterized by the disruption of continuity between the coracoclavicular (C-C) ligaments and proximal or distal bone fragments. However, owing to the rarity of such fractures, there is currently no universally accepted surgical procedure for their treatment. Recently, the scorpion plate, an anatomical, non-locking, pre-contoured plate with two grasping arms to fix the distal or inferior clavicular fragments, was introduced. This study aimed to investigate the postoperative functional and radiological outcomes of osteosynthesis using only scorpion plates in Neer type V fractures. We retrospectively identified 23 patients who underwent scorpion plate fixation for Neer type V fractures at two general hospitals. All patients underwent only plate fixation without C-C ligament augmentation. Subsequently, we investigated their postoperative functional outcomes, complication rates, and modified C-C distance ratio at 1 year. The mean postoperative Constant score was 96 ± 5, with all cases achieving bone union. Complications within 1 year postoperatively included plate loosening in one patient (4.3%) and plate irritation in two patients (8.7%). Additionally, the modified C-C distance ratio averaged 114 ± 15%. This study offers novel insights into the management of Neer type V distal clavicle fractures. Our findings indicate that osteosynthesis using only scorpion plates can lead to satisfactory functional outcomes with minimal complications.

Spring-Wire Technique as a Cost-Effective Alternative for Volar Rim Fragment Fixation in Distal Radius Fractures.

Introduction Volar rim fragment fixation is difficult to manage, as it is distal to the watershed line, rendering normal volar plates unable to securely capture it. This fragment must be precisely addressed as volar carpal subluxation is unavoidable when fixation is not efficient. The spring-wire technique maintains a stable fixation of this key fragment, which has been previously described in a small series. Materials and methods This is a prospective study of 20 patients who presented to El-Hadara University Hospital in Alexandria between the years 2020 and 2022, with complex distal radius fractures and small volar rim fragments, who were treated by open reduction and internal fixation using the spring-wire technique. The study was approved by the institutional review board of Alexandria Main University Hospital, and informed consent was taken from all patients in this study ensuring compliance with ethical standards. All patients underwent open reduction and internal fixation using the spring-wire technique. The procedure was performed by the same surgical team to ensure consistency. Postoperative radiographs were taken to assess reduction quality and fixation. Postoperative radiographic parameters, range of motion, grip strength and the El-Hadara wrist function scoring system were obtained after one year of follow-up, to evaluate results of fixation. Results All patients achieved a functional range of motion and grip strength and showed radiological union of the volar rim fragment with no volar carpal subluxation or escape of the volar rim fragment. The El-Hadara wrist function average score was 18.85±2.66, which represented a good overall result. No complications occurred during follow-up, and none of the patients required removal of the implant. Conclusion The spring-wire technique maintains a stable fixation of the volar rim fragment that cannot be held securely by volar plating alone. This method offersa low-profile implant that is readily available and simple to apply. Also, the fragment is stabilized by a dual effect by both the spring wire and the volar plate that act as a buttress to volar displacement.

ANALYSIS OF OPEN REDUCTION AND INTERNAL FIXATION (ORIF) IN COLLES' FRACTURE

Colles fracture, first described in 1814, is characterized by the dorsal displacement of the distal radius fragment and is highly prevalent, particularly among elderly patients. This study aims to evaluate the effectiveness of Open Reduction and Internal Fixation (ORIF) in treating Colles fractures, focusing on functional outcomes and postoperative quality of life. An integrative literature review and comparative analysis of studies on ORIF and other treatment methods were conducted using Google Scholar, Scopus, and Web of Science as indexing tools. Articles were selected using the keywords “Colles Fracture, Open Reduction and Internal Fixation, Functional Outcomes, Postoperative Complications.” The review highlights that ORIF generally provides superior functional outcomes and fewer complications in various fractures, such as those of the humerus, tibial pilon, calcaneus, and unstable distal radius fractures, compared to less invasive methods like external fixation (EF). However, EF shows advantages in specific cases, such as shorter surgical time and fewer perioperative complications. Moreover, the studies indicate that risk factors like diabetes, fracture severity, lack of drainage, and bone graft usage increase the risk of complications in ORIF. Additionally, minimally invasive techniques can reduce pain and enhance functional recovery in certain fractures, such as patellar fractures, when compared to ORIF.

Fixing Cho Type IIC Distal Clavicle Fractures with Hook Plates Leads to a High Incidence of Subacromial Osteolysis: A Retrospective Study and Literature Review.

This retrospective study investigates the complications, particularly subacromial osteolysis (SAO), associated with hook plate (HP) fixation, in the treatment of unstable distal clavicle fractures characterized by complete coracoclavicular (CC) ligament rupture. The decision-making process for employing HP in fractures of this nature, such as Neer types IIB and V and Cho classification IIC, involves considerations of distal fragment size and displacement. While HP offers advantages in clinical practice, it is not without complications, with SAO being a notable concern. Factors such as non-anatomic hook tip placement and fracture classification may influence the risk of SAO. The study comprises a retrospective analysis of unstable distal clavicle fractures treated with HP at our institution from 2019 to 2022. Exclusions include non-displaced fractures, those treated with other locking plates, and pathologic fractures. A total of 91 patients with displaced distal clavicle fractures underwent open reduction and internal fixation with HP. Cho classification was employed to differentiate cases with CC ligament rupture. Patient demographics, classifications, postoperative radiographs, distal fragment size, plate position, timing of implant removal, and complications, including SAO, were recorded. Among the 91 patients, 32 were classified as Cho IIB, 43 as Cho IIC, and 16 as Cho IID. Ninety-one percent exhibited solid union before implant removal. The prevalence of SAO was 43.8%, 76.7%, and 62.5% in Cho IIB, IIC, and IID, respectively. Univariate analysis revealed a significant difference only in Cho classification (p = 0.014). Binary logistic regression identified Cho classification type IIC as the sole risk factor for SAO (p = 0.021; odds ratio, 4.48; 95% confidence interval, 1.56-12.87). Cho type IIC fractures, characterized by CC ligament deficiency causing horizontal instability, demonstrated the highest SAO rate. In contrast, Neer type IIB fractures retained the trapezoid ligament, and Neer type V fractures had intact CC ligaments, resulting in lower SAO rates. Biomechanically, combining HPs with CC ligament reconstruction provided better structural stability than using HPs alone in treating Cho type IIC fractures.

Comparison of distal extremity magnetic resonance imaging findings in Australian racing Standardbreds and Thoroughbreds.

Foot-related lameness is common in Standardbred and Thoroughbred racehorses. Magnetic resonance imaging (MRI) provides information on both the soft tissue and osseous structures of the distal extremity. The aim of this study was to determine whether abnormalities identified on distal limb MRI differed between these two racehorse populations. The records of Standardbred and Thoroughbred racehorse distal extremity MRI examinations conducted at Camden Equine Centre and Ballarat Veterinary Practice between 2013 and 2023 were retrieved. Horses were included if pain causing lameness had been localised to the foot using perineural or intra-articular analgesia. MRI abnormalities of the structures within the distal extremity were recorded and comparisons made between the two groups. There was a significant difference in the rate of occurrence of certain MRI abnormalities between the Thoroughbred and Standardbred racehorse populations, including distal phalangeal fractures, proximal phalangeal short tau inversion recovery (STIR) hyperintensity (distal aspect), the presence and severity of ungular cartilage ossification, abnormalities of the navicular bone distal border synovial invaginations/vascular channels and navicular bone distal border fragments. The presence of distal extremity STIR hyperintensity and fractures was significantly higher in Standardbred compared to Thoroughbred racehorses when these findings were grouped and considered in combination. There were many similarities in the distal extremity MRI abnormalities identified in lame Australian Standardbred and Thoroughbred racehorses. However, distal phalangeal fractures, ungular cartilage ossification and distal extremity STIR hyperintensity were identified in significantly more in Standardbred than Thoroughbred racehorses.

Type 4 Tibial Tuberosity Avulsion Fractures: Surgical Treatment Early Outcomes and a Presentation of the Distal Cortical Fixation.

Background: The most published surgical technique for fixating Type 4 (Salter-Harris II) tibial tubercle avulsion fractures is uni-cortical in nature, and stability is suboptimal. This study presents a technique modification that is consistent with AO principles, by which the screws are aimed distally to purchase the posterior cortex of the distal fragment. This technique is defined as a "Distal Cortical Fixation". This modification has not been studied to date and harbors potential advantages. We aimed to assess the safety and efficacy of surgical fixation techniques for the above-mentioned fractures and to describe the new modification. Methods: A retrospective review was conducted at a level 1 children's hospital for surgically treated Salter-Harris II tibial tubercle fractures. Inclusion criteria were patients who sustained Salter-Harris II tibial tubercle avulsion fractures and were documented to reach one of two radiographic endpoints: union (regardless of alignment) or non-union that necessitated additional interventions. Medical records and radiographic studies were analyzed for fracture union and alignment. A comparative analysis was conducted to evaluate outcomes based on different fixation techniques that included Distal Cortical Fixation, a Proximal Screw Technique, and a crossed or multiple screws/pins construct. Results: A total of 37 patients were included with a mean age of 14.8 ± 1.2 years, with 34/37 (91.9%) being male. The most common procedure was a 1 to 3 screw fixation with a Distal Cortical Fixation (n = 21 (56.75%)), followed by a Proximal Screw Technique (n = 8, 21.62%), and a crossed or multiple screws/pins construct (n = 8, 21.62%). There was no difference between the groups in medical history and demographic features. The mean follow-up duration was 35.17 ± 36.79 weeks. There were no non-unions, and only a minimal change in the sagittal and coronal alignment (0.4 ± 1.94 (p = 0.872) and 0.53 ± 3.51 (p = 0.296) degrees, respectively) was noted and was not associated with the surgical technique. Conclusions: The surgical treatment of Salter-Harris II tibial tubercle avulsion fractures, including Distal Cortical Fixation, was presented and was found to provide satisfactory union rates on a short term follow up.

Titanium Cable Cerclage Increases the Load to Failure in Plate Osteosynthesis for Distal Femoral Fractures.

Background and Objectives: The reduction of two-part oblique or spiral fractures of the distal femur using steel wire cerclage prior to plate osteosynthesis is a proven procedure. In addition to being useful in fracture reduction, wire cerclage was also shown to increase the stability of osteosynthesis. Nevertheless, metal corrosion and the allergenic potency of steel remain problematic disadvantages of this method. A biomechanical study was carried out to evaluate titanium cable cerclage as an alternative supplement for plate osteosynthesis of a distal femoral two-part fracture. Materials and Methods: An unstable AO/OTA 32-A2.3 fracture was created in eleven pairs of nonosteoporotic human cadaver femora. All the samples were treated with polyaxial angular stable plate osteosynthesis. One femur from each pair was randomly selected for an additional fracture fixation with multifilament titanium cable cerclage. Stepwise cyclic axial loading was applied in a load-to-failure mode using a servohydraulic testing machine. Results: All specimens (mean age: 80 years; range: 57-91 years) withstood a cycling force of at least 1800 N. With a mean load of 2982 N (95% CI: 2629-3335 N), the pressure forces resulting in osteosynthesis failure were significantly higher in specimens with an additional titanium cerclage (Group 1) than in samples that were solely treated with plate osteosynthesis (Group 2) at 2545 N (95% CI: 2257-2834 N) (p = 0.024). In both groups, cutting out the distal screws at the condyle region, resulting in shearing of the distal fragment proximal to the fracture line, was the most frequent cause of construct failure. Among the specimens assigned to Group 1, 36% exhibited a specific fracture pattern, namely, a fracture of the dorsal buttress above the cerclage. Analysis of axial stiffness (p = 0.286) and irreversible deformity of the specimens revealed no differences between the groups (p = 0.374). Conclusion: Titanium cable cerclage application, as a supplement to an angular stable plate, resulted in an increased load to failure. In terms of stability, the use of this adjunct for fracture fixation of supracondylar two-part oblique femoral fractures might, therefore, be an option, especially in patients who are sensitive to nickel.

A proposal for name-tagging three-dimensional distal radial fracture fragments based on preliminary results.

Melone introduced a classification system for distal radial fractures, emphasizing the intra-articular patterns. We explore the significance of key part fragments and introduce a three-dimensional fracture tagging system based on an updated version of Melone's concept.

Preventing Iatrogenic Fibula Fractures Using the Push-Pull Technique: A Biomechanical Comparison of Unicortical Versus Bicortical Post Screws.

Displaced diaphyseal fractures can be reduced using the push-pull technique, wherein a plate is affixed to the distal fragment of the fracture, a post screw is placed proximal to the plate, and a lamina spreader creates distraction. This study evaluated the load to failure and mechanism of failure of bicortical and unicortical post screws during reduction. Four matched pairs of cadaver legs were subjected to a 2-cm oblique osteotomy simulating a displaced, oblique diaphyseal fracture. A 6-hole compression plate was affixed to the distal fragment with 2 unicortical locking screws, and a 12-mm unicortical or 20-mm bicortical screw was inserted as a post screw proximal to the plate. A lamina bone spreader was used to exert a distraction force between the plate and the post screw. A mechanical actuator simulated the distraction procedure until failure. Maximum applied load, displacement, and absorbed energy were recorded and compared across unicortical and bicortical groups by paired t tests. At maximum load, we found statistically significant differences in displacement (P=.003) and energy absorbed (P=.022) between the two groups. All unicortical screws failed through screw toggle and bone cut-out. Bicortical screws failed through bending, with no visible damage to the bone at the screw site. When diaphyseal fractures are significantly shortened and require a greater distraction force to achieve reduction, bicortical screws demonstrate a higher mechanical load to failure and increased bone loss from the screw-removal site. A unicortical post screw may be used if minimal distraction is needed. [Orthopedics. 2024;47(5):308-312.].

Treatment of Acute Acromioclavicular Joint Dislocation Using Hook Plate: A Systematic Review and Meta-Analysis and Update of Current Literature

Abstract Background the hook plate metallic device showed early promise as an alternative implant to treat unstable acromioclavicular joint dislocation injuries. The hook plate can be used to provide an indirect reduction of a distal clavicle fracture. This indirect reduction technique is useful for comminuted fractures or fractures with very small distal fragments in which conventional reduction and fixation is difficult. Aim of the Work to evaluate the treatment of acute acromioclavicular joint dislocation and radiographic outcomes. Materials and Methods Studies were considered eligible if they expressed treatment of acromioclavicular joint dislocation using the hook plate and described the patient's clinical and functional outcomes; intra-operative, post-operative complications, full-text articles were available, randomized controlled trials, including cluster RCTs, controlled (non-randomized) clinical trials or cluster trials, prospective and retrospective comparative cohort studies, and case-control or nested case-control studies. We will exclude cross-sectional studies, case series, case reports and literature not in English. All items that didn't match the above criteria were excluded. Results The total studies included 270 patients with average mean age 35.5 years and mean follow up 25.33 months. The Constant Murely score average 84 points (The CMS was developed for the evaluation of shoulder function with subjective and objective components) and the p value <.05 that means all patients had significant improvement. Full range of motion could be achieved in the patients. Patients with restrictions of range of motion mainly showed limitations in abduction and external rotation. These limitations are most probably caused by the post-operative immobilization, which is necessary after implantation of hook plates to ensure healing of the ligament structures and avoid damage of the acromion by the hook itself. Other studies also showed restrictions of range of motion for abduction and external rotation after hook plate implantation. Conclusion it has a good to excellent Constant Murely score (full range of motion) that enables quick return to activities. It is useful for (Rockwood III-VI). So good clinical results can be achieved with hook plate.

Description of new sign of integral (∫) for rotational deformity of distal femur.

Femur shaft fractures commonly occur due to high velocity trauma and most of them are fixed with nailing. Malrotation is common after fixation. A rotational malalignmentmore than 30° is a deformity which requires correction. Various techniques described for rotational deformities are: the 'cable techniques' for the determination of varus-valgus malalignment; the 'hyperextension test', 'radiographic recurvatum sign', 'tibial plateau sign', and 'meterstick technique' for length analysis; and the 'hip rotation test', 'lesser trochanter shape sign', 'cortical step sign', and 'diameter difference sign' for rotational analysis. We describe integration sign at the medial or lateral aspect of notch of femur in fixed internal or external rotation due to condensation of trabeculae. This is a prospective observational study. Informed consent was taken, and this study was approved by institutional review board. C arm imaging study of 50 knees was done at our institution in which rotational profile of distal femur was analyzed In 3 different views -AP , Internal and external rotation views. The rotation views were taken sequentially and each observer was asked to identify the sign at its appearance and at rotation when it was best seen. All the observers were asked to draw the sign on linear line diagram of distal femur. The data was analysed statistically. Sign of integral (∫) for rotational deformity was seen at Mean external rotation of 22±1.71 with a range of 19 degree to 25 degree and Mean internal rotation of 15.78±1.21 with a range of 14 degree to 18 degree. The integration sign can be used as intraoperative C arm sign to understand the rotational deformity of distal fragment of femur. This helps the surgeon to understand the alignment and revise if needed intraoperatively. If combined with position of lesser trochanter, this will give alignment for both proximal as well as distal fragment of femur.

Biomechanical Consequences of Proximal Screw Placement in Minimally Invasive Surgery for Hallux Valgus Correction

Hallux valgus is one of the most common surgically corrected forefoot deformities. Studies evaluating clinical outcomes of minimally invasive chevron and akin (MICA) procedure have shown shorter operation time, faster recovery, and smaller scars compared to the open approach. Previous biomechanical cadaveric studies have largely focused on the open approach with minimal on MICA. To our knowledge, no studies have compared different proximal screw placements in MICA which can either be three-point fixation or intramedullary. This study aims to compare the biomechanical properties of fixation between these 2 techniques in MICA. Six matched pairs of human fresh frozen cadaveric feet were randomized to either 3-point fixation or intramedullary groups. Both procedures were performed by a single fellowship-trained orthopedic foot and ankle surgeon. Using a material testing machine, each specimen underwent 1000 cycles of plantar-to-dorsal uniaxial loads from 0 to 31 N in cantilever configuration while monitoring bending stiffness and distal fragment dorsal angulation. They were then subjected to load until failure at a compression rate of 10 mm/min. Specimens from both groups tolerated the walking fatigue test. Mean bending stiffness of 3-point fixation was 84% higher than intramedullary constructs (p = .002). Mean dorsal angulation of intramedullary was thrice that of 3-point fixation constructs (p = .008). Mean load to failure of 3-point fixation was 30% higher than intramedullary constructs (p = .001). Three-point fixation provide superior biomechanical stability compared to intramedullary proximal screw placement. The surgical technique using 3-point proximal screw fixation can offer robust fixation and lead to better clinical outcomes.

Laparoscopic Cholecystectomy-Induced Complex Common Bile Duct Injury: Will Rescue ERCP Help?

AbstractA 33-year-old woman presented for laparoscopic cholecystectomy (LC)-induced accidental transection of the common bile duct at the level of confluence and common hepatic duct cutoff (E5–Bismuth type 5 injury) along with transected indwelling biliary stent hanging in the right posterior duct (RPD). At endoscopic retrograde cholangiopancreatography (ERCP), the distal fragment was removed. The RPD stent was cannulated across and retrieved, followed by three plastic stents in the right and left hepatic duct. Prompt referral of a bile duct injury during LC to a specialized center with timely ERCP saved the day and averted the need for surgical intervention.

Analysis of benzimidazole anthelmintic resistance in parasitic nematodes <i>Haemonchus contortus</i> using nested isothermal amplification (PCR)

The purpose of the research is to monitor farms located in the European part of the Russian Federation to identify resistance to effects of benzimidazole anthelmintics in populations of nematodes Haemonchus contortus dwelling in the gastrointestinal tract of small cattle.Materials and methods. The studies were conducted in slaughterhouses located in the Moscow Region in 2023–2024. At the first stage, taxonomic identification of parasitic nematodes and larvae (L3) was made, and Strongylata species was determined from sheep. The study material was the abomasum with duodenum fragments and a distal rectum fragment with feces. For molecular studies, we used mature nematodes and H. contortus L3 larvae isolated from the abomasum and feces of small cattle brought to slaughterhouses in the Moscow Region from 8 regions of the European part of the Russian Federation: Moscow, Astrakhan, Oryol, Lipetsk, Tula, Bryansk regions, Stavropol and Dagestan. The studies were conducted at the premises of the Laboratory of Molecular Biology, the VNIIP – FSC VIEV. Statistical processing of the obtained data was made, and mean infection rates of parasitic nematodes (infection intensity and prevalence) were determined. Fifty-six DNA samples of nematodes H. contortus were examined using nested isothermal amplification (PCR) to identify gene alleles that determine resistance to benzimidazole drugs.Results and discussion. Molecular genetic studies of H. contortus DNA sampled from sheep brought from different Regions only detected homozygous individuals (100%) resistant to benzimidazole in the parasitic nematode population from the Oryol Region. Other regions identified only homozygous and heterozygous individuals susceptible to benzimidazole.

Efficacy and Complications of Fixator-Assisted Correction with Internal Fixation in the Genu Valgum.

Two basic methods for genu valgum correction are osteotomy and internal fixation or external fixator assited correction. External fixators have the advantage of stabilizing fragments before osteotomy allowing better control of fragments and preventing secondary displacements. The purpose of this study was to evaluate the efficacy and complications of fixator assisted correction for genu valgum and internal fixation, using the AO distal femur pediatric osteotomy plate. Thirty-six limbs in 26 patients (age 10-16 years) underwent osteotomy in the distal femur at CORA. Open lateral wedge osteotomy was done; the desired position obtained was temporarily stabilized by connecting the pins with the AO external fixator and stabilized with 90 degrees AO distal femur pediatric locking plate and gap grafted with hydroxyapatite bone granules. Translation of distal fragment was required in 17 osteotomies (53.12%). Osteotomies united within 12 weeks; no non-union was observed. The range of motion was full in all patients. The mean tibiofemoral angle was corrected by 12 degrees and the mean mechanical LDFA was corrected to 87 degrees. There was no secondary deformity, either in the rotational or sagittal plane. This method combines the modularity of external fixator and the advantages of internal fixation.

Transvenous extraction of conduction system pacing leads: An international multicenter (TECSPAM) study

BackgroundConduction system pacing (CSP) by His bundle pacing or left bundle branch area pacing (LBBAP) is incorporated into Heart Rhythm Society guidelines for the management of bradycardia and cardiac resynchronization therapy. Despite increasing adoption with both lumenless leads and stylet-driven leads, concerns regarding the feasibility and safety of the extraction of CSP leads remain. ObjectiveThe aim of the study was to report on the safety, feasibility, and clinical outcomes of the extraction of CSP leads. MethodsPatients undergoing the extraction of CSP leads from 10 international centers were enrolled in this retrospective study. Data regarding indications, lead location, lead type, extraction tools, procedural success, complications, and reimplantation in the conduction system were collected. ResultsOverall, 341 patients (age 69 ± 15 years; female 117 (34%); cardiomyopathy 157 (46%); lead dwell time 22 ± 26 months) underwent the extraction of 224 His bundle pacing and 117 LBBAP leads (lumenless leads 321; stylet-driven leads 20). Complete procedural success was achieved in 338 (99%), while clinical success was 100% with retained distal fragments in 3 patients (1%). Among patients with a lead dwell time of >6 months (6–193 months; n = 226), manual extraction was successful in 198 (87%), mechanical tools in 22 (10%), and laser in 6 (3%). Femoral tools were necessary in 3 patients. Minor complications occurred in 7 patients (2.1%). Reimplantation in the conduction system was successful in 233 of 244 patients attempted (95%). ConclusionThe overall success rates of the extraction of CSP leads were very high (although the LBBAP lead dwell time was <3 years), with a low need for extraction tools and minimal complication. Reimplantation in the conduction system is feasible and safe.

Factors Causing Unintended Sagittal and Axial Alignment Changes in High Tibial Osteotomy: Comparative 3-Dimensional Analysis of Simulation and Actual Surgery

Background: Unintended secondary changes in the posterior tibial slope (PTS) and tibial torsion angle (TTA) may occur after medial open-wedge high tibial osteotomy (MOWHTO). In surgical procedures using patient-specific instruments (PSIs), it is essential to reproduce the PTS and TTA that were planned in simulations. Purpose: To analyze the factors causing unintended sagittal and axial alignment changes after MOWHTO. Study Design: Case series; Level of evidence, 4. Methods: Overall, 63 patients (70 knees) who underwent MOWHTO using a PSI between June 2020 and June 2023 were retrospectively reviewed. Preoperative and postoperative computed tomography scans were 3-dimensionally reconstructed. Simulated osteotomy was performed so that the weightbearing line could pass through the target point. A PSI gapper was 3-dimensionally printed to fit the posteromedial corner of the osteotomy gap in the simulated HTO model. After MOWHTO using the PSI gapper, the actual postoperative model was compared with the preoperative or simulation model. This assessment included PTS, TTA, hinge axis, and osteotomy-related parameters. Cortical breakage around the lateral hinge was evaluated to assess stability. Results: The mean PTS and TTA did not change in the simulation. However, significant changes were observed in the actual postoperative PTS and TTA (change, –2.4°± 2.2° and −3.9°± 4.7°, respectively). The PTS was reduced, while the TTA decreased with internal rotation of the distal fragment. The difference in the axial hinge axis angle (AHA) between the simulation and actual surgery was the factor most correlated with the difference in the PTS (r = 0.625; P < .001). In regression analysis, the difference in the AHA was the only factor associated with the difference in the PTS (β = 0.558; P = .001), and there were no factors that showed any significant associations with the difference in the TTA. In subgroup analyses for the change in the TTA, the correction angle and anterior osteotomy angle were significantly higher in the more internal rotation group (P = .023 and P = .010, respectively). The TTA change was significantly higher in the unstable group with lateral cortical breakage (P = .018). The unstable group was more likely to show an internal rotation of ≥5° (odds ratio, 5.0; P = .007). Conclusion: The AHA was associated with a difference in the PTS between the simulation and actual surgery. The change in the TTA was caused by a combination of multiple factors, such as a large correction angle and anterior osteotomy angle, but mainly by instability of the lateral cortical hinge.

Cementless Total Hip Arthroplasty With Paavilainen Femoral Shortening Osteotomy Can Provide Good Results at 10 Years in Patients Who Have Crowe IV Developmental Dysplasia of the Hip

BackgroundThe aim of this study was to present the clinical and radiologic results of primary total hip arthroplasty (THA) using the femoral shortening osteotomy technique described by Paavilainen in patients who have Crowe IV developmental dysplasia of the hip. MethodsWe retrospectively analyzed the results of primary THA using the Paavilainen technique in 335 hips. The mean follow-up was 10.2 years. The degree of limp, leg-length discrepancy, and patient satisfaction were assessed. The Oxford Hip Score was used to examine functional outcomes. A number of radiographic parameters were also assessed. ResultsThe most common reason for revision surgery was nonunion of the distally advanced greater trochanter. This complication was observed in 22 hips (6.5%). The 10-year survival for acetabular components, it was 97.3%, and for femoral components was 98.7% with aseptic loosening as the end point, and 85.9% with reoperation for any reason as the end point. Patients demonstrated improved functional outcomes. The mean limb lengthening was 27.8 mm. Nonunion was more common if the contact length of the proximal femoral fragment with the lateral surface of the distal femoral fragment was less than 35 mm. ConclusionsCementless primary THA using the femoral shortening osteotomy technique described by Paavilainen in patients who have Crowe IV dysplasia of the hip demonstrates good clinical and radiologic postoperative results. If the contact between the fragments after osteotomy is less than 35 mm, there is a high risk of nonunion, and supplemental fixation may be warranted.

Intramedullary Impaction of the Basicervical Component Is Determinant of Fixation Failure in a Simple Two-Part Pertrochanteric Fracture.

To evaluate initial fracture morphology influences on outcomes in simple 2-part pertrochanteric fracture, with a focus on the basicervical component and its initial impaction. A retrospective cohort series. Single Level I Trauma Center. Patients older than 60 years with intertrochanteric fractures between 2011 and 2022 were retrospectively reviewed. Inclusion criteria comprised simple 2-part pertrochanteric fractures (Orthopaedic Trauma Association [OTA]/Arbetisgemeinschaftfur Osteosynthesefragen [AO] 31-A1.2) with a basicervical component who underwent cephalomedullary nailing and had a minimum follow-up of 6 months. Patients were divided whether the basicervical component was impacted into the medullary canal (intramedullary impaction [II] group) or displaced beyond the medullary canal (extramedullary [E] group). Exclusion criteria encompassed pathologic fractures, nondisplaced fractures, and basicervical neck fractures (OTA/AO 31-B3). Reduction status was assessed as unacceptable if the head and neck (proximal) fragment was positioned intramedullary with respect to the distal fragment in either the anterior posterior or cross-lateral x-ray and acceptable otherwise. In addition, the degree of impaction on x-ray and CT scans (coronal, sagittal, axial) at injury was analyzed as a risk factor for failure. Revision rates and lag screw sliding over 15 mm were compared between the II and E groups. Hundred fifteen patients (95 female, average age 80 years) were included. The II group (n = 58) compared with E group (n = 57) showed more acceptable postoperative reductions (57% vs. 81%, P = 0.001), but significantly higher fixation failure (16% vs. 3.5%, P = 0.048) and fracture collapse (28% vs. 7%, P = 0.01). II was identified as a significant independent predictor for failure (odds ratio 5.64, 95% confidence interval, 2.14-16.9, P < 0.001) with more than 19.5-mm impaction in sagittal CT scan as the threshold linked to increased failure risk. This study highlights the significance of specific intertrochanteric fracture patterns, particularly II of a basicervical component and impaction severity (≥19.5 mm), as drivers of fixation failure. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.