Identification and validation of miR-29b-3p and LIN7A as important diagnostic markers for bone non-union by WGCNA.

Bone non-union is a common fracture complication that can severely impact patient outcomes, yet its mechanism is not fully understood. This study used differential analysis and weighted co-expression network analysis (WGCNA) to identify susceptibility modules and hub genes associated with fracture healing. Two datasets, GSE125289 and GSE213891, were downloaded from the GEO website, and differentially expressed miRNAs and genes were analysed and used to construct the WGCNA network. Gene ontology (GO) analysis of the differentially expressed genes showed enrichment in cytokine and inflammatory factor secretion, phagocytosis, and trans-Golgi network regulation pathways. Using bioinformatic site prediction and crossover gene search, miR-29b-3p was identified as a regulator of LIN7A expression that may negatively affect fracture healing. Potential miRNA-mRNA interactions in the bone non-union mechanism were explored, and miRNA-29-3p and LIN7A were identified as biomarkers of skeletal non-union. The expression of miRNA-29b-3p and LIN7A was verified in blood samples from patients with fracture non-union using qRT-PCR and ELISA. Overall, this study identified characteristic modules and key genes associated with fracture non-union and provided insight into its molecular mechanisms. Downregulated miRNA-29b-3p was found to downregulate LIN7A protein expression, which may affect the healing process after fracture in patients with bone non-union. These findings may serve as a prognostic biomarker and potential therapeutic target for bone non-union.

Temporary Stabilization of Tibia Fractures: Does External Fixation or Temporary Plate Fixation Result in Better Outcomes?

Background: Provisional stabilization of high-energy tibia fractures using temporary plate fixation (TPF) or external fixation (ex-fix) prior to definitive medullary nailing (MN) is a strategy common in damage control orthopaedics. There is a lack of comprehensive data evaluating outcomes between these methods. This study compares outcomes of patients stabilized with either TPF or ex-fix, and with early definitive MN only, assessing complications including nonunion and deep infection. Methods: A retrospective review was performed on adult patients with tibia fractures treated with MN followed until fracture union (≥3 months) at a single level-1 trauma center from 2014 to 2022. Medical records were evaluated for nonunion and deep infection. Demographics, injury characteristics, and fixation methods were recorded. Significance between patients who underwent TPF and ex-fix was compared with a matched cohort of early MN using Pearson's exact tests, independent t-tests, and one-way ANOVA, depending on the appropriate variable. Results: 81 patients were included; 27 were temporized with TPF (n = 12) or ex-fix (n = 15). 54 early MN cases defined the matched cohort. All groups had similar patient and fracture characteristics. The difference in rates of nonunion between groups was significant, with TPF, ex-fix, and early MN groups at 17, 40, and 11% respectively (p = 0.027). Early MN had lower rates of nonunion (11% vs. 40%, p = 0.017) and deep infection (13% vs. 40%, p = 0.028) compared to ex-fix. Conclusion: Temporary ex-fix followed by staged MN was associated with higher rates of nonunion and deep infection. There was no difference in complication rates between TPF and early definitive MN. These data suggest that ex-fix followed by MN of tibia fractures should be avoided in favor of early definitive MN when possible. If temporization is needed, TPF may be a better option than ex-fix. Level of Evidence: IV.

Radiographic and functional results of Ilizarov fixation in the management of nonunion of tibia and femur fractures: a retrospective case series.

BACKGROUND: Femoral and tibial fractures may result in delayed union and nonunion, posing significant challenges in orthopedic practice. The Ilizarov technique has emerged as a promising solution for managing these complex cases. OBJECTIVES: Evaluate the radiographic and functional results of Ilizarov fixation in the treatment of nonunion of tibia and femur fractures. DESIGN: Retrospective. SETTINGS: Hospitals affiliated with a university hospital. PATIENTS AND METHODS: Patient demographics, fracture characteristics, and treatment details were analyzed for the period from October 2015 to September 2022 in patients who were treated for nonunion of the tibia and femur using the Ilizarov fixator. Clinical and radiological assessments were performed using the Association for the Study and Application of Methods of Ilizarov (ASAMI) criteria. The study focused on assessing the average duration for union and frame removal, bone results, successful union rates, and functional results using the ASAMI criteria, obtaining data from the existing medical records, spanning various medical facilities treating nonunion fractures. SAMPLE SIZE: 126 patients. RESULTS: The average duration for union and frame removal was 8 months, with excellent bone results observed in 60.32% of cases. Out of 126 patients, 118 achieved successful union, while there were 2 failure cases necessitating amputation (1.52%). Functional results revealed excellent outcomes in 39.68% of cases. Complications included pin tract infections, ankle and knee stiffness, and limb shortening. External fixation duration and infection eradication were consistent with previous research, emphasizing the technique's effectiveness. CONCLUSIONS: The Ilizarov technique proved highly effective in managing nonunion tibia and femur fractures, offering favorable outcomes in terms of union, infection control, pain relief, and functional recovery. While excellent bone outcomes do not guarantee optimal function, this method remains a reliable approach for complex cases. LIMITATIONS: Potential biases inherent in retrospective analyses and the need for further randomized controlled trials to comprehensively compare treatment modalities.

Erythropoietin as promoter of engraftment for treatment of radius/ulnar non-union fracture in a dog: Case report.

Background: Fractures with large bone defects and non-unions are a great challenge for veterinary orthopaedists. In small dog breeds, this complication is commonly encountered in fractures of the radius and ulna due to poorer vascularisation of the distal antebrachium region. Case Description: A case of radius/ulnar non-union in a 1.5-year-old Pinscher occurring after trauma and two successive unsuccessful osteosyntheses is described. During the operative revision, after the removal of existing bone implants, the bone defect was filled with cortical autologous bone graft. Autocancellous bone mixed with erythropoietin was applied proximally and distally to the cortical autograft for stimulation of bone healing. The post-operative period was without complications. As early as the 9th post-operative week, the animal was able to bear weight on the limb, without signs of lameness, pain, and swelling. Radiologically, a very good bridging of the graft was observed. Fifteen weeks after the operative revision, the fracture was completely healed with excellent clinical outcome. Conclusion: The application of autogenous cortical bone graft and cancellous autograft mixed with erythropoietin demonstrated an excellent therapeutic effect and resulted in complete regeneration of the large bone defect over a 15-week period.

Minimally Invasive Surgical Management of Chronic Cough-Induced Rib Fracture Non-Union: A Case Report.

BACKGROUND Nonunion of a rib fracture can cause chronic pain, and pharmacological pain management may lead to medication dependence. This report describes a 54-year-old man with a chronic cough and painful nonunion fracture of the left posterior 8th rib, managed with minimally invasive surgery and a rib splint. CASE REPORT A 54-year-old man presented with chronic cough-induced left chest wall pain. Three-dimensional chest computed tomography (CT) scan showed a nonunion of a fracture of the left posterior 8th rib. After medical management failure, we proposed a surgical approach with the aim to remove the tissue comprising the nonunion, release the nerve, and stabilize the bone stumps. To avoid the adverse effects of a large incision, we designed a minimally invasive strategy based on ultrasound fracture localization and the use of an intramedullary splint. The pain disappeared immediately after surgery. The patient was discharged in 24 hours. At 6-week follow-up, he was still asymptomatic, and a new CT scan reconfirmed the correct splint position. From the immediate postoperative evaluation until the last follow-up visit, he consistently reported full satisfaction. CONCLUSIONS This report has highlighted the challenges of management of chronic pain in nonunion of a rib fracture, and has described the use of a minimally invasive surgical approach. In this single case, our tailored surgical strategy achieved definitive success in pain management, minimizing postoperative complications/adverse effects and avoiding the addition of pain medications despite a 24-hour hospital stay. Our goal is to share an alternative solution for colleagues facing similar cases.

Achieving Bone Healing Non-Operatively in Humeral Fractures in Two Patients with Risk Factors for Nonunion Utilizing a Specialized Orthosis.

We report the treatment of two patient with humeral fractures with one or more risk factors for nonunion. The first patient was elderly with a previously diagnosed central nervous sys-tem injury. The second elderly patient previously sustained a cerebral vascular accident affecting the fractured arm. The fracture was oblique in the proximal third of the humerus. We achieved bone healing non-operatively utilizing a spe-cialized plastic orthosis that included a deforming element made of dense foam. This device asymmetrically increases the soft tissue pressure around the fracture.

Versatility of the medial corticoperiosteal flap: from recalcitrant non-unions up to large bony defects.

BACKGROUND: Reconstructive microsurgery techniques using vascularized bone grafts have revolutionized the treatment of complex cases associated with recalcitrant non-unions or osteomyelitis. The medial femoral corticoperiosteal flap (MFCP flap) has emerged as a valuable option in bone reconstruction. Its clinical applications have been extended over the years considering this flap from non-unions with minimal bone lost, up to large intercalary defects of the upper and lower extremities. This article aims to present the clinical applications and outcomes of the MFCP flap in various reconstructive scenarios. METHODS: Seventy-nine patients with persistent non-union and bone defects of the upper and lower limb were evaluated from June 2008 to October 2020. All of them were reconstructed with a corticoperiosteal flap from the medial femoral condyle in our hospital. Previous procedures, bone gap and type of flap used were recorded. Postoperative functional status was assessed with time of bone healing, complications and clinical final outcome. RESULTS: Radiological evidence of bone union was observed at 4.09 months (range 2-9). Healing rate was 97% with periosteal corticocancellous flaps (PCC flaps) and 93% with corticoperiosteal flaps (CP flaps). Average follow-up was 14.5 months (range 5-28). There were no significant donor site complications. CONCLUSIONS: The MFCP flap offers a versatile and reliable option for bone reconstruction. Its ability to provide vascularized bone tissue with low morbidity enhances the healing process and improves outcomes. The MFCP flap has been increasing its applications and it serves as a valuable option in the treatment of recalcitrant non-unions or bony defects irrespective of site and size up to 5 cm in the upper and lower extremities.

Management of non-union of rib fractures secondary to trauma: A scoping review.

OBJECTIVE: Rib fracture non-union is an uncommon complication of traumatic rib fractures. Our objective was to perform a scoping review of the literature for the management of rib fracture non-union. This included analysis of the variations in surgical technique, complications experienced, and reported outcomes. METHODS: We conducted a scoping review and searched databases (MEDLINE, CINAHL, and Embase). We performed abstract and full-text screening, and abstracted data related to pre-operative assessment, surgical technique, complications, and reported outcome measures. RESULTS: We included 29 articles of which 19 were case reports and 10 were case series. The data quality was generally heterogeneous. The studies included 229 patients and the commonest symptoms of rib fracture non-union included chest pain, clicking, dyspnea and deformities. The patients underwent surgical management of rib fracture non-union (excluding first rib fractures) using various techniques. The majority used surgical stabilization of rib fracture with or without a graft. The reported outcomes were inconsistent between studies, but showed high rates of union (>94 %), reduction in reported VAS scores, and improved return to work when included. Implant failure occurred in 10 % of the 229 total patients reported in our studies, the re-operation rate was 13 %, and the overall complication rate was 27 %. CONCLUSION: Surgical management of rib fracture non-union often involving locking plates and screws with or without a graft has been shown in several case reports and series as an effective treatment with acceptable implant failure and complication rates. Surgical management is therefore a viable option for symptomatic patients. Further research is required to determine optimal management strategies that further reduce surgical complications for these patients.

A comparative study of volar locking-plate fixation with corticocancellous and pure cancellous bone grafts for scaphoid nonunion with dorsal intercalated segmental instability secondary to scaphoid humpback deformity.

INTRODUCTION: Bone grafts for scaphoid nonunion with deformity include cortcicocancellous or pure cancellous bone grafts. This study compared the outcomes between two types of bone grafts when employing a volar locking-plate in patients with scaphoid nonunion with dorsal intercalated segmental instability (DISI). PATIENTS AND METHODS: This retrospective study included 34 patients with scaphoid nonunion and DISI due to humpback deformity treated between March 2017 and January 2022. Two types of bone grafts were obtained from iliac crest. Twenty of the corticocancellous (CC) group underwent a wedge-shaped graft, while 14 patients of the pure cancellous (C-only) group received graft chips. In both groups, a 1.5-mm anatomically pre-contoured locking plate was used for fixation. Radiographic evaluations included the union rate and carpal alignment including scapholunate angle (SLA), radiolunate angle (RLA), intrascaphoid angle (ISA) and scaphoid height to length ratio (HLR). Clinical assessments encompassed wrist range-of-motion, grip strength, and patient-reported outcomes. RESULTS: Nineteen of the 20 patients in the CC group and 12 of the 14 patients in the C-only group respectively, achieving osseous union. The mean follow-up period in CC group was 14.7 (range, 12 ∼ 24) months and that in C-only group was 12.6 (range, 12 ∼ 15) months. Postoperatively, there were no significant intergroup differences of radiographic parameters including SLA (CC; 49.9° ± 6.7° vs. C-only; 48.9° ± 3.5°, P = 0.676), RLA (1.7° ± 6.4° vs. 2.4° ± 3.3°, P = 0.74), ISA (36° ± 7.5° vs. 36.6° ± 12.2°, P = 0.881), and HLR (0.54 ± 0.09 vs. 0.53 ± 0.05, P = 0.587). Clinical outcomes, including the flexion-extension arc (137° ± 30° vs. 158° ± 33°, P = 0.122), grip strength (93.4 % ± 15.4% vs. 99.5 % ± 16.7 %, P = 0.39), Quick Disabilities of the Arm, Shoulder, and Hand scores (11.2 ± 8.3 vs. 12.5 ± 7.7, P = 0.74) and Mayo Wrist Scores (81.2 ± 13.1 vs. 89 ± 11.4, P = 0.242) also showed no significant intergroup differences. CONCLUSIONS: Volar locking-plate fixation with pure cancellous bone grafts achieved outcomes comparable to those achieved with corticocancellous bone grafts in scaphoid nonunion with deformity, possibly due to the biomechanical advantages of the volar plate to provide structural supports.

Comparison of reamer irrigator aspirator (RIA) suspension versus bone marrow aspirate concentrate (BMC) for percutaneous treatment of long bone nonunions-A preclinical canine model.

OBJECTIVE: To compare the bone healing effects of percutaneously delivered bone marrow aspirate concentrate (BMC) versus reamer irrigator aspirator (RIA) suspension in a validated preclinical canine ulnar nonunion model. We hypothesized that BMC would be superior to RIA in inducing bone formation across a nonunion site after percutaneous application. The null hypothesis was that BMC and RIA would be equivalent. METHODS: A bilateral ulnar nonunion model (n= 6; 3 matched pairs) was created. Eight weeks after segmental ulnar ostectomy, RIA from the ipsilateral femur and BMC from the proximal humerus were harvested and percutaneously administered into either the left or right ulnar defect. The same volume (3 ml) of RIA suspension and BMC were applied on each side. Eight weeks after treatment, the dogs were euthanized, and the nonunions were evaluated using radiographic, biomechanical, and histologic assessments. RESULTS: All dogs survived for the intended study duration, formed radiographic nonunions 8 weeks after segmental ulnar ostectomy, and underwent the assigned percutaneous treatment. Radiographic and macroscopic assessments of bone healing at the defect sites revealed superior bridging-callous formation in BMC-treated nonunions. Histologic analyses revealed greater amount of bony bridging and callous formation in the BMC group. Biomechanical testing of the treated nonunions did not reveal any significant differences. CONCLUSION: Bone marrow aspirate concentrate (BMC) had important advantages over Reamer Irrigator Aspirator (RIA) suspension for percutaneous augmentation of bone healing in a validated preclinical canine ulnar nonunion model based on clinically relevant radiographic and histologic measures of bone formation.

Treatment of AVN-Induced Proximal Pole Scaphoid Nonunion Using a Fifth and Fourth Extensor Compartmental Artery as a Vascularized Pedicle Bone Graft: A Retrospective Case Series.

BACKGROUND Scaphoid nonunion (SN) is a challenging condition in wrist pathology, often resulting in severe consequences if left untreated. Surgical intervention, particularly using vascularized bone grafts (VBGs), is a promising but uncertain approach. The 4+5 extensor compartment artery (ECA) pedicled graft, less commonly used for SN, has potential benefits due to its vascular supply and accessibility to the scaphoid. This study aimed to evaluate the effectiveness of the 4+5 ECA pedicled graft combined with headless compression screw fixation in treating avascular necrosis (AVN)-induced proximal pole SN. Radiological results, functional outcomes, and complications related to this method were assessed. MATERIAL AND METHODS This was a retrospective analysis of 19 proximal pole SN cases with AVN treated using the 4+5 ECA-VBG technique from 2016 to 2022. Patients underwent preoperative evaluation and postoperative follow-up for at least 1 year. Data on surgery, demographics, radiological assessments, and functional outcomes were recorded and analyzed statistically. RESULTS All patients achieved radiographic union within 8.5 weeks postoperatively, with revascularization of proximal pole necrosis. Significant improvements in functional outcomes were observed, including pain reduction, increased wrist range of motion, improved grip and pinch strength, and enhanced wrist scores. No major complications were reported. CONCLUSIONS The 4+5 ECA-VBG technique, with headless compression screw fixation, showed high success rates in treating AVN-induced proximal pole SN. This method offers comprehensive restoration of wrist function and minimal complications, making it a viable option for SN management, especially in AVN cases. Further research is needed to confirm these results and establish standardized protocols for SN treatment.

SVF Therapy of Delayed Fracture Union in Patients with Multiple Combat Injury. Case Report.

Delayed union of fractures is one of the most frequent complications in orthopedic practice, especially in polytrauma patients. With the development of new methods of regenerative medicine, including the use of adipose derived stromal cells as a component of the stromal-vascular fraction (SVF), new possibilities for conservative treatment of this problem have emerged. This article presents a clinical case of conservative treatment of delayed union of a radial bone fracture using local SVF injections. In the fracture space, SVF with PRP creates a pool of cells that could differentiate towards surrounding tissue, releases various inducers of tissue growth and, via an indirect chemotactic effect on receptors, mobilizes the body's own resources and creates conditions for angiogenesis and trophism in the injured segment. In the patient with delayed consolidation after SFV-therapy, progress in clinical and radiological dynamics was noted with complete healing within 7 months. The positive clinical result provides a basis for further study and implementation in practice.

Long-term outcome of nonunion of the lateral humeral condyle fracture in children: a multicentre retrospective study.

PURPOSE: Lateral humeral condyle nonunion in children is a rare condition. The treatment protocol for nonunion of lateral humeral condyle remains controversial due to the potential complication. This study reports long-term functional outcomes of the nonunion of the lateral humeral condyle fracture. In addition, we identified the prognostic factors for nonunion of the lateral humeral condyle fracture. METHODS: We conducted a multicentre retrospective cohort study of nonunion of lateral humeral condyle between January 1995 and December 2022. The patient's preoperative demographic information was reviewed. Potential risk factors of poor functional outcome, such as age, duration from initial injury, and fracture displacement, were retrieved. Functional outcomes at the latest follow-up visit were evaluated using the Mayo Elbow Performance Score (MEPS). Multivariable linear regression was deployed to evaluate the association of potential risk factors with the functional outcome. RESULTS: A total of 63 patients from eight medical centers were included, of which 60 were surgically treated. Patients' average age was 7.3 years old, with a mean follow-up duration of seven years. All nonunion cases were successfully treated, resulting in a normalized humeroulnar angle. The rate of AVN was 16.7%. All patients reported excellent range of motion and MEPS at the latest follow-up. Multivariable linear regression demonstrated that Fracture displacement (ß = -0.88, 95% CI -1.55 to -0.22, p = 0.010) and duration from initial injury (ß = -0.09, 95% CI -0.17 to -0.02, p = 0.010) were statistically significant factors influencing functional outcome of lateral humeral condyle nonunion. CONCLUSIONS: Initial fracture displacement and duration from the initial injury are statistically significantly associated with elbow function in lateral humeral condyle nonunion. However, the effect size for these factors is relatively small and does not reach clinical significance. Despite this, the functional outcome is excellent in all patients, with an average follow-up duration of seven years.

Functional outcome and risk of non-union for 5th metatarsal base fractures.

OBJECTIVES: Treatment of 5th metatarsal fractures via direct discharge from virtual fracture clinic (VFC) has become common practice in the NHS. We aim to assess the functional outcome and incidence of non-union in a series of 5th metatarsal base fractures, exposed to 1-year of follow-up. METHODS: 194 patients who sustained a fracture between the period February 2019 to April 2020 were included, referred via the VFC pathway. Radiographs were reviewed to classify in which zone, the fracture occurred along with union on subsequent follow-up. Telephone follow-up was used to measure patient functional outcomes (EQ-5D & FAAM survey) and satisfaction with the VFC service. RESULTS: Off 194 patients, 53 (27.3%) had zone 1, 99 (51%) had zone 2, and 42 (21.6%) had zone 3 fractures. 80 were discharged directly from VFC, with 114 patients being offered at least one face to face clinic follow-up. Six (3.1%) patients had clinical and radiological evidence of non-union; 4 in zone 2, and 2 in zone 3. No zone 1 injuries were identified as a non-union. Only 2 patients had surgery, 1 of which was for symptomatic non-union. Of the 6 non-union patients, 1 had surgery, 4 did not wish to have surgery and the final non-union patient was deemed unsuitable for surgery. CONCLUSION: The VFC is an effective way of managing 5th metatarsal fractures, with high patient satisfaction. Conservative management has excellent outcomes, with a low percentage of zone 2 and 3 injuries developing a symptomatic non-union. Functional outcome surveys provide further reassurance.

Anterior peri-sacroiliac joint osteotomy in the treatment of malunion and nonunion of complex pelvic ring fracture: techniques and preliminary results.

PURPOSE: To introduce anterior peri-sacroiliac joint osteotomy (APSJO) through the lateral-rectus approach (LRA) for treating pelvic fracture malunion and nonunion, and to evaluate the safety, feasibility, and potential effectiveness. METHODS: Data of 15 patients with pelvic fracture malunion and nonunion who underwent treatment by APSJO were selected and analyzed. The reduction quality was assessed using the Mears and Velyvis criteria, while the pre-operative and post-operative function was revealed by the Majeed scoring system. The British Medical Research Council (BMRC) grading system was recruited for the evaluation of lumbosacral plexus function. RESULTS: The average operative duration was 264.00 ± 86.75 min, while the intra-operative blood loss was 2000 (600, 3000) mL. Anatomical reduction was complete in three cases, satisfactory in ten cases, and unsatisfactory in two cases. Among the seven patients with lumbosacral plexus injury, the pre-operative Majeed grades were good in two cases, fair in two cases, and poor in three cases, while the post-operative Majeed grades were excellent in three cases, good in three cases, and fair in one case. Muscle strength recovered to M5 in two cases, M4 in three cases, and showed no recovery in two cases. The pre-operative Majeed grades were good in five cases, fair in two cases, and poor in one case of the series without lumbosacral plexus injury, while the post-operative Majeed grades were excellent in seven cases and good in one case. CONCLUSION: APSJO through LRA may be a feasible strategy for treating pelvic fracture malunion and nonunion with promising application.

Polytherapy versus monotherapy in the treatment of tibial non-unions: a retrospective study.

BACKGROUND: Treating tibial non-unions efficiently presents a challenge for orthopaedic trauma surgeons. The established gold standard involves implanting autologous bone graft with adequate fixation, but the addition of biologicals according to the so-called diamond concept has become increasingly popular in the treatment of non-unions. Previous studies have indicated that polytherapy, which involves implanting mesenchymal stem cells, bioactive factors and osteoconductive scaffolds, can improve bone healing. This study aims to evaluate the efficacy of polytherapy compared with monotherapy in treating tibial non-unions of varying severity. MATERIALS AND METHODS: Data from consecutive tibial non-unions treated between November 2014 and July 2023 were retrospectively analysed. The Non Union Scoring System (NUSS) score before non-union surgery, and the Radiographic Union Score for Tibial fractures (RUST), scored at 1, 3, 6, 9, 12 and 18 months post-surgery, were recorded. Initially, a comparison was made between the polytherapy and monotherapy groups. Subsequently, patients receiving additional surgical non-union treatment were documented, and the frequency of these treatments was tallied for a subsequent per-treatment analysis. RESULTS: A total of 34 patients were included and divided into a polytherapy group (n = 15) and a monotherapy group (n = 19). The polytherapy group demonstrated a higher NUSS score (44 (39, 52) versus 32 (29, 43), P = 0.019, z = -2.347) and a tendency towards a higher success rate (93% versus 68%, P = 0.104) compared with the monotherapy group. For the per-treatment analysis, 44 treatments were divided into the polytherapy per-treatment group (n = 20) and the monotherapy per-treatment group (n = 24). The polytherapy per-treatment group exhibited a higher NUSS score (48 (43, 60) versus 38 (30, 50), P = 0.030, z = -2.173) and a higher success rate (95% versus 58%, P = 0.006) than the monotherapy per-treatment group. Within the monotherapy per-treatment group, the NUSS score displayed excellent predictive performance (AUC = 0.9143). Setting the threshold value at 48, the sensitivity and specificity were 100.0% and 70.0%, respectively. CONCLUSIONS: Polytherapy is more effective than monotherapy for severe tibial non-unions, offering a higher success ratio. The NUSS score supports decision-making in treating tibial non-unions. LEVEL OF EVIDENCE: Level III.

[Correlation between combined deflection angle classification adduction typing and complications after internal fixation of adduction femoral neck fracture].

Objective: To analyze the correlation between postoperative complications and combined deflection angle classification adduction type (CDAC-ADT) of femoral neck fractures after cannulated screw internal fixation. Methods: The clinical data of 121 patients with CDAC-ADT femoral neck fracture admitted between January 2018 and December 2021 and met the selected criteria were retrospectively analyzed. There were 69 males and 52 females, the age ranged from 19 to 79 years (mean, 48.1 years). The causes of injury included 52 cases of traffic accident, 24 cases of falling from height, and 45 cases of fall. The time from injury to operation ranged from 2 to 12 days, with an average of 6.0 days. Among them, there were 18 cases of CDAC-ADT type Ⅰ, 46 cases of type Ⅱ, and 57 cases of type Ⅲ; 6 cases of Garden type Ⅱ, 103 cases of type Ⅲ, and 12 cases of type Ⅳ; and according to the location of the fracture line, there were 26 cases of subcapitate type, 88 cases of transcervical type, and 7 cases of basal type. All patients were treated with cannulated screw internal fixation. The occurrence of complications (including internal fixation failure, fracture nonunion, and osteonecrosis of the femoral head) was recorded, and the correlation between complications and CDAC-ADT typing, Garden typing, and fracture line location were analyzed. Results: The patients were followed up 8-44 months, with a mean of 24.9 months. There were 10 cases of internal fixation failure, 7 cases of fracture nonunion, and 30 cases of osteonecrosis of the femoral head after operation. Correlation analysis showed that patients' CDAC-ADT typing was significantly correlated with the overall incidence of complication and the incidence of internal fixation failure, fracture nonunion, and osteonecrosis of the femoral head ( P<0.05), and the Pearson coefficient of contingency were 0.435, 0.251, 0.254, and 0.241, respectively. Garden typing did not correlate with the overall incidence of complication and the incidence of internal fixation failure and fracture nonunion ( P>0.05), but correlated with the incidence of osteonecrosis of the femoral head ( P<0.05), and the Pearson coefficient of contingency was 0.251. Fracture line position typing had no correlation with the overall incidence of complication and the incidence of internal fixation failure, fracture nonunion, and osteonecrosis of the femoral head ( P>0.05). Conclusion: CDAC-ADT typing has obvious correlation with postoperative complications of femoral neck fracture and can be used to predict complications of femoral neck fracture.

Human nonunion tissues display differential gene expression in comparison to physiological fracture callus.

The healing of bone fractures can become aberrant and lead to nonunions which in turn have a negative impact on patient health. Understanding why a bone fails to normally heal will enable us to make a positive impact in a patient's life. While we have a wealth of molecular data on rodent models of fracture repair, it is not the same with humans. As such, there is still a lack of information regarding the molecular differences between normal physiological repair and nonunions. This study was designed to address this gap in our molecular knowledge of the human repair process by comparing differentially expressed genes (DEGs) between physiological fracture callus and two different nonunion types, hypertrophic (HNU) and oligotrophic (ONU). RNA sequencing data revealed over ∼18,000 genes in each sample. Using the physiological callus as the control and the nonunion samples as the experimental groups, bioinformatic analyses identified 67 and 81 statistically significant DEGs for HNU and ONU, respectively. Out of the 67 DEGs for the HNU, 34 and 33 were up and down-regulated, respectively. Similarly, out of the 81 DEGs for the ONU, 48 and 33 were up and down-regulated, respectively. Additionally, we also identified common genes between the two nonunion samples; 8 (10.8 %) upregulated and 12 (22.2 %) downregulated. We further identified many biological processes, with several statistically significant ones. Some of these were related to muscle and were common between the two nonunion samples. This study represents the first comprehensive attempt to understand the global molecular events occurring in human nonunion biology. With further research, we can perhaps decipher new molecular pathways involved in aberrant healing of human bone fractures that can be therapeutically targeted.