Melatonin, a potentially effective drug for the treatment of infected bone nonunion.

Osteomyelitis (OM), characterized by heterogeneity and complexity in treatment, has a high risk of infection recurrence which may cause limb disability. Management of chronic inactive osteomyelitis (CIOM) without typical inflammatory symptoms is a great challenge for orthopedic surgeons. On the basis of data analysis of 1091 OM cases, we reported that latent osteogenic decline in CIOM patients was the main cause of secondary surgery. Our research shows that impairment of osteoblasts capacity in CIOM patients is associated with ferroptosis of osteoblasts caused by internalization of Staphylococcus aureus. Further studies show that melatonin could alleviate ferroptosis of osteoblasts in infected states through Nox4/ROS/P38 axis and protect the osteogenic ability of CIOM patients. Knockout of NADPH oxidase 4 (Nox4) in vivo could effectively relieve ferroptosis of osteoblasts in the state of infection and promote osteogenesis. Through a large number of clinical data analyses combined with molecular experiments, this study clarified that occult osteogenic disorders in CIOM patients were related to ferroptosis of osteoblasts. We revealed that melatonin might be a potential therapeutic drug for CIOM patients and provided a new insight for the treatment of OM.

[Augmenting locking plate with autologous bone graft for the treatment of nonunion of long bone fracture in the lower extremity with retaining of the original intramedullary nail].

OBJECTIVE: To explore clinical effect of attaching locking plate with bone grafting based on retaining the original intramedullary nail in treating non-union after intramedullary nail fixation of long shaft fractures of lower limbs. METHODS: A retrospective study was conducted on 20 patients treated with non-union fractures after intramedullary nailing of long shaft fractures of lower limbs from June 2015 to June 2020. All patients were treated with the original intramedullary nailing and bone grafting from the iliac bone, and were underwent open reduction plate internal fixation and bone grafting for old fractures. Among them, 14 were males and 6 were females, aged from 35 to 56 years old with an average of (42.2±9.6) years old. Nine patients were femoral shaft fracture and 11 patients were tibial shaft fracture. According to characteristics of fracture end nonunion, 6 patients were stable/atrophic, 9 patients were unstable/large, and 5 patients were unstable/atrophic. The nonunion time ranged from 8 to 12 months with an average of(9.8±2.0) months after the initial surgery. Visual analogue scale (VAS), knee range of motion, bone healing time, complications and fracture-end healing were recorded before and at the latest follow-up. RESULTS: All patients were followed up for 18 to 48 months with an average of (36.3±10.5) months. The incision of all patients were healed at stageⅠwithout complications such as infection or internal fixation ruptur. Healing time of femur and tibia was (8.5±2.6) months and (9.5±2.2) months. Knee joint motion increased from preoperative (101.05±8.98) ° to postoperative (139.35±8.78) ° at the latest follow-up (t=-12.845, P<0.001). VAS decreased from preoperative (5.15±1.72) to postoperative (0.75±0.96) at the latest follow-up (t=11.186, P<0.001). CONCLUSION: On the basis of retaining the original intramedullary nail, the addition of locking plate internal fixation and autogenous iliac bone grafting have advantages of simple operation, less trauma, fewer complications and high fracture healing rate. It is one of the effective surgical schemes for the treatment of nonunion after intramedullary nail fixation of long bone fracture of lower extremity.

Advances in the Application of Bone Transport Techniques in the Treatment of Bone Nonunion and Bone Defects.

Bone nonunion and bone defects frequently occur following high-energy open injuries or debridement surgeries, presenting complex challenges to treatment and significantly affecting patients' quality of life. At present, there are three primary treatment options available for addressing bone nonunion and bone defects: vascularized bone grafts, the Masquelet technique, and the Ilizarov technique. The Ilizarov technique, also known as distraction osteogenesis, is widely favored by orthopedic surgeons because of several advantages, including minimal soft tissue requirements, low infection risk, and short consolidation time. However, in recent years, the application of the Masquelet technique has resulted in novel treatment methods for managing post-traumatic bone infections when bone defects are present. Although these new techniques do not constitute a panacea, they continue to be the most commonly employed options for treating complex large bone nonunion and bone defects. This review evaluates the currently available research on the Ilizarov and Masquelet bone transport techniques applied at various anatomical sites. Additionally, it explores treatment durations and associated complications to establish a theoretical foundation that can guide clinical treatment decisions and surgical procedures for the management of bone nonunion and bone defects.

Biomaterial scaffolds regulate macrophage activity to accelerate bone regeneration.

Bones are important for maintaining motor function and providing support for internal organs. Bone diseases can impose a heavy burden on individuals and society. Although bone has a certain ability to repair itself, it is often difficult to repair itself alone when faced with critical-sized defects, such as severe trauma, surgery, or tumors. There is still a heavy reliance on metal implants and autologous or allogeneic bone grafts for bone defects that are difficult to self-heal. However, these grafts still have problems that are difficult to circumvent, such as metal implants that may require secondary surgical removal, lack of bone graft donors, and immune rejection. The rapid advance in tissue engineering and a better comprehension of the physiological mechanisms of bone regeneration have led to a new focus on promoting endogenous bone self-regeneration through the use of biomaterials as the medium. Although bone regeneration involves a variety of cells and signaling factors, and these complex signaling pathways and mechanisms of interaction have not been fully understood, macrophages undoubtedly play an essential role in bone regeneration. This review summarizes the design strategies that need to be considered for biomaterials to regulate macrophage function in bone regeneration. Subsequently, this review provides an overview of therapeutic strategies for biomaterials to intervene in all stages of bone regeneration by regulating macrophages.

Masquelet technique with radical debridement and alternative fixation in treatment of infected bone nonunion.

Background: Infected bone nonunion is the toughest problem in fracture-related infection, leading to high disability and recurrence. The aim of this study was to evaluate the effectiveness of the Masquelet technique with radical debridement and alternative fixation in the management of infected bone nonunion. Patients and Methods: A retrospective study of prospectively collected data in two trauma centers was performed from 2016 to 2020. Patients diagnosed as infected bone nonunion were included in this study. The initial implant was removed and all patients received a two-stage Masquelet procedure with radical debridement and alternative fixation. The disappearance of inflammatory manifestations and regression of infection indicators (such as interleukin-6 (IL-6), C-reactive protein, white blood cell count) to the normal range were regarded as radical debridement. The alternative fixation depended on local soft tissue conditions. Results were evaluated according to clinical and radiographic assessment and patient satisfaction. Results: A total of 23 patients were included in our study. Six of them received internal fixation, while the other 17 received external fixation. Of the 23 cases, 21 were successfully reconstructed without infection recurrence, except 2 reinfected cases. Mean full weight bearing time was 6.6 months follow-up post last surgery. Out of the 23, 20 cases had satisfactory functional outcomes without additional bone or soft tissue comorbidities. Discrepancies in leg length and joint stiffness were observed in three cases and marked as unsatisfied results. Conclusions: Infected bone nonunion can be successfully managed using the Masquelet technique under radical debridement combined with an alternative fixation method.

[Comparative study of monolateral and circular fixator in the treatment of infectious tibial nonunion].

OBJECTIVE: To compare treatment effect of monolateral and circular external fixator in infectious tibial nonunion and to explore external fixation structure with better osteogenic ability and fewer complications. METHODS: A retrospective analysis was performed on 150 patients with infectious tibial nonunion admitted from January 2010 to December 2014. Patients who met the inclusion and exclusion criteria were divided into monolateral fixator group and circular fixator group according to the type of external fixation. Demographic and perioperative data of the two groups were collected. New bone quality was assessed by pixels ratio, treatment effect was assessed by complications. Notes for treatment was explored by case analysis. RESULTS: A total of 64 patients with infectious mid-tibial nonunion were included, 26 in monolateral fixator group and 38 in circular fixator group. There was no difference in demographic data between two groups. The pixel ratio of new bone between two groups was from 0.91 to 0.97 with an average of (0.94±0.03), and from 0.93 to 0.97 with an average of(0.95±0.02), respectively, with no statistical significance (P>0.05). The external fixation index was from 34.1 to 50.6 with an average of (42.3±8.3) days /cm in monolateral fixator group and from 44.5 to 56.1 with an average of (45.8±10.3) days/cm in the circular fixator group, and the difference was not statistically significant (P>0.05). There were 7 cases (26.9%) of complications in monolateral fixator group and 5 cases (13.2%) in circular fixator group, the difference was not statistically significant (P>0.05), but 5 cases of foot ptosis in monolateral fixator group and none in circular fixator group. The time of weight bearing in monolateral fixator group was later than that in circular fixator group, and the difference was statistically significant (P<0.05). CONCLUSION: Monolateral and circular fixators can achieve equivalent bone formation in the treatment of infected tibial nonunion. Circular fixator is recommended for patients with severe osteoporosis or concomitant medical diseases requiring early weight bearing. Hydroxyapatite coated screws are recommended if a monolateral external fixator is selected when the expected enlarged length is long and the fixation time is long and close monitoring of the ankle movement is required to avoid foot droop.

[NRD assisted Ilizarov technique in the treatment of infected bone and soft tissue defect of tibia].

OBJECTIVE: To investigate the clinical effect of NRD assisted Ilizarov technique in the treatment of infected bone and soft tissue defect of tibia. METHODS: All 48 patients with infected bone and soft tissue defect of tibia were randomly divided into study group and control group from March 2013 to December 2020. There were 34 males and 14 females, aged from 24 to 55 years old with an average of (40.54±11.64) years old. There were 25 patients in the study group, including 17 males and 8 females, aged from 31 to 55 years old with an average of (41.36±9.69) years old. The study group were treated with NRD assisted with Ilizarov bone transport technique. There were 23 patients in control group, including 17 males and 6 females, aged from 24 to 53 years old with an average of(38.61±8.76) years old. The control group were treated with traditional bone transport technique. The curative rate, recurrence rate, incidence rate of pin track infection, time of using antibiotics, time of wound healing, time of carrying external fixation, time of bone transport, time of bone healing and postoperative function were used to evaluate the therapeutic effect of the two groups. RESULTS: The follow-up period was from 12 to 62 months with an average of (33.0±7.2) months. At the final follow-up, there was no significant difference in the curative rate between the two groups (P>0.05). The recurrence rate in the study group was lower than that in the control group(P<0.05). The incidence of pin track infection in the study group was lower than that in the control group (P<0.05). The time of using antibiotics and wound healing in the study group was shorter than that in the control group(P<0.05). There was no significant difference in the time of bone transport and carrying of external fixation between the two groups(P>0.05). There was no significant difference in bone healing and postoperative function between the two groups(P>0.05). CONCLUSION: NRD assisted Ilizarov technique can achieve satisfactory results in the treatment of infected bone and soft tissue defect of tibia and shorten the treatment period and the time of using antibiotics. It is worthy of development in clinic.

[Effectiveness of tunnel osteogenesis technique in treatment of aseptic non-hypertrophic nonunion of femoral shaft].

Objective: To investigate the effectiveness of tunnel osteogenesis technique combined with locking plate in the treatment of aseptic non-hypertrophic nonunion of femoral shaft. Methods: The clinical data of 23 cases of aseptic non-hypertrophic nonunion of femoral shaft treated with tunnel osteogenesis technique combined with locking plate between January 2017 and December 2020 were retrospectively analysed. There were 17 males and 6 females with an average age of 41.4 years (range, 22-72 years). There were 22 cases of closed fracture and 1 case of open fracture. The types of internal fixation at admission included intramedullary nail in 14 cases and steel plate in 9 cases. The number of nonunion operations received in the past was 0 to 1; the duration of nonunion was 6-60 months, with an average of 20.1 months. Among them, there were 17 cases of aseptic atrophic nonunion of the femoral shaft and 6 cases of dystrophic nonunion. Twenty-two cases were fixed with 90° double plates and 1 case with lateral single plate. The operation time, theoretical blood loss, hospitalization stay, nonunion healing, and postoperative complications were recorded. Harris hip function score, Lysholm knee function score, lower extremity function scale (LEFS), and short-form 36 health survey scale (SF-36) were used at last follow-up to evaluate hip and knee functions. Visual analogue scale (VAS) score was used to evaluate the relief of pain at 1 day after operation and at last follow-up. Results: The average operation time was 190.4 minutes, the average theoretical blood loss was 1 458.4 mL, and the average hospitalization stay was 8.2 days. All the 23 patients were followed up 9-26 months, with an average of 18.2 months. The healing time of nonunion in 22 patients was 3-12 months, with an average of 5.6 months. There were 8 cases of limb pain, 8 cases of claudication, 6 cases of limitation of knee joint movement, and 2 cases of limitation of hip joint movement. At last follow-up, the imaging of 1 patient showed that the nonunion did not heal, accompanied by pain of the affected limb, lameness, and limitation of knee joint movement. At 1 day after operation, the VAS score of 23 patients was 6.5±1.8, the pain degree was good in 7 cases, moderate in 12 cases, and poor in 4 cases; at last follow-up, the VAS score was 0.9±1.3, the pain degree was excellent in 21 cases and good in 2 cases, which were significantly better than those at 1 day after operation ( t=12.234, P<0.001; Z=-5.802, P<0.001). At last follow-up, the average Harris hip function score of 22 patients with nonunion healing was 94.8, and the good rate was 100%; Lysholm knee function score averaged 94.0, and the excellent and good rate was 90.9%; LEFS score averaged 74.6; SF-36 physical functioning score averaged 85.0 and the mental health score averaged 83.6. Conclusion: Tunnel osteogenesis technique combined with locking plate in the treatment of aseptic non-hypertrophic nonunion of femoral shaft has a high healing rate and fewer complications, which can effectively relieve pain and improve lower limb function and quality of patients' life.

The effect of TLR-4 on the proliferation and differentiation of bone mesenchymal stem cells and its relationship with the Wnt signal transduction pathway during bone nonunion.

Background: Bone nonunion is a special fracture complication that occurs in about 5% to 10% of cases. This type of fracture is difficult to heal, and causes great pain to patients and affects their quality of life. The mechanism of bone nonunion is not clear. In our study, we investigated the influence of Toll-like receptor (TLR)-3, TLR-4, and Wnt signaling pathways on the occurrence of bone nonunion. Methods: Firstly, we established a Sprague Dawley (SD) rat model of femoral nonunion, and detected the expression levels of TLR-3, TLR-4, ß-catenin, nemo-like kinase (NLK), c-Jun N-terminal kinase (JNK), and other proteins during model construction. For in vitro experiments, primary cultured bone mesenchymal stem cells (BMSCs) were divided into 4 groups: lipopolysaccharide (LPS, agonist of TLR-4) group, LPS + CLI095 (inhibitor of TLR-4) group, control group, and LPS + substance P (SP) group. The expression of ß-catenin, NLK, JNK, and ALP and the osteogenic differentiation ability of cells were detected during culture. Results: X-ray and hematoxylin and eosin (HE) staining results confirmed the successful modeling of bone nonunion. During the formation of the bone nonunion model, the expression of TLR-4 showed an upward trend. In vitro experiment results showed that inhibition of TLR-4 expression could enhance the proliferation and differentiation ability of BMSCs. The expression of ß-catenin, the core protein of the canonical Wnt signaling pathway, increased rapidly in the first 2 weeks of bone nonunion construction, and decreased after 2 weeks. Non-canonical Wnt signaling pathway proteins NLK and JNK had no change in the first 2 weeks, and showed an upward trend after 2 weeks. In vitro experiment results showed that the expression of ß-catenin was dominant in BMSCs with strong proliferation and differentiation ability, while the expression of NLK and JNK was dominant in BMSCs with weak proliferation and differentiation ability. These results suggest that the Wnt signaling pathway may regulate the occurrence of bone nonunion. Conclusions: TLR-4 inhibits the proliferation and differentiation of BMSCs, and the transformation of the canonical Wnt signaling pathway to the non-canonical Wnt signaling pathway may lead to bone nonunion. Our study may provide new insights into the treatment of bone nonunion.

Fat infiltration of paraspinal muscles as an independent risk for bone nonunion after posterior lumbar interbody fusion.

BACKGROUND: The prognosis value of paraspinal muscle degeneration on clinical outcomes has been revealed. However no study has investigated the effect of the fat infiltration (FI) of paraspinal muscles on bone nonunion after posterior lumbar interbody fusion (PLIF). METHODS: Three hundred fifty-one patients undergoing PLIF for lumbar spinal stenosis with 1-year follow-up were retrospectively identified. Patients were categorized into bone union (n = 301) and bone nonunion (n = 50) groups based on dynamic X-ray at 1-year follow-up. The relative total cross-sectional area (rTCSA) and FI of multifidus (MF) and erector spinae (ES), and the relative functional CSA (rFCSA) of psoas major (PS) were measured on preoperative magnetic resonance imaging. RESULTS: The nonunion group had a significantly higher MF FI and a higher ES FI and a smaller MF rTCSA than the union group (p = 0.001, 0.038, 0.026, respectively). Binary logistic regression revealed that MF FI (p = 0.029, odds ratio [OR] = 1.04), lumbosacral fusion (p = 0.026, OR = 2193) and length of fusion (p = 0.001, OR = 1.99) were independent factors of bone nonunion. In subgroup analysis, in one or two-level fusion group, the patients with nonunion had a higher MF FI and a higher ES FI than those of the patients with union (all p < 0.05). Similarly, in lumbosacral fusion group, the patients with nonunion had a higher MF FI and a higher ES FI than those of the patients with union (all p < 0.05). The logistic regressions showed that MF FI remained an independent factor of bone nonunion both in the patients with one or two-level fusion (p = 0.003, OR = 1.074) and in the patients with lumbosacral fusion (p = 0.006, OR = 1.073). CONCLUSIONS: Higher fatty degeneration was strongly associated with bone nonunion after PLIF. Surgeons should pay attention to the FI of paraspinal muscles when performing posterior surgery for patients, especially those who need short-segment fusion or to extend fusion to S1.

Evolution and Development of Ilizarov Technique in the Treatment of Infected Long Bone Nonunion with or without Bone Defects.

The treatment of infected bone nonunion and bone defects is a considerable challenge in the orthopedics field. The standard clinical therapy methods include local free bone transplantation, vascularized bone graft, and the Ilizarov technique; the first two are controversial due to the iatrogenic self-injury. The Ilizarov bone transport technique has been widely used to treat infected bone nonunion and bone defects, and good clinical effect has been demonstrated. Yet, it brings many related complications, which exerts additional suffering to the patient. The best treatment is to combine bone defect rehabilitation with infection control, intramedullary nail fixation, appropriate time for bone grafts, beaded type scaffold slippage and new Taylor fixation, reducing the external fixation time and the incidence of complications, thereby reducing the occurrence of patients' physical and psychological problems. This review focuses on the induction, summary and analysis of the Ilizarov bone transport technique in the treatment of infected long bone nonunion with or without bone defects, providing new ideas and methods for orthopedic disease prevention and treatment by the Ilizarov technique, which is following the development direction of digital orthopedics.

Management algorithm of external fixation in lower leg arterial injury for limb salvages.

PURPOSE: The aim of this study is to investigate the outcome of these limb-threatening injuries through external fixation treatment and to discuss the case of patients' functional recovery after external fixation. METHODS: Demographics, surgical treatment and outcomes in 88 patients with lower leg arterial injuries treated by external fixation at two trauma centers from 2009 to 2018 were reviewed. The primary outcome was the rate of successful lower leg salvage, while secondary outcomes were complications and functional recovery. RESULTS: Eighty-eight patients were identified and 80 patients (90 legs) maintained a successful lower leg salvage. The mean age was 32.7 ± 10.8 years, and 81.8% were male. The primary outcomes included the following complications: pin-tract infection (8 legs), pins loosening (4 pins), wound superficial infection (7 legs), deep infection developed osteomyelitis (3 legs), bone nonunion or bone defect (17 legs) and amputation (8 legs). The average healing time of fracture was 5.6 ± 4.3 months. The maintain of external fixation average time was 5.8 ± 3.6 months. The improvement of scores of the pain, function and quality of life in our follow-up was statistically significant. CONCLUSION: For the lower extremity fracture patients with vascular injuries, using external fixation correctly can improve clinical outcomes and produce the improvement of pain, function and the quality of life. LEVEL OF EVIDENCE: Retrospective cohort, level IV.

Synergistic effects of autologous platelet-rich plasma combined with an extracorporeal shock wave in treatment of long diaphysis aseptic nonunion.

INTRODUCTION: Union of long bone fractures is a complicated biological mechanism affected by numerous systemic and local variables. Disruption of any of these components may result in fracture nonunion. There are various types of clinically available treatment strategies for aseptic nonunion. Both activated platelet plasma and extracorporeal shock waves play important roles in fracture healing. This study aimed to investigate the interaction of platelet-rich plasma (PRP) and extracorporeal shock wave (ESW) in bone healing of nonunion. HYPOTHESIS: PRP and ESW have synergistic effects in treating long bone nonunion. METHODS: Between January 2016 and December 2021, a total of 60 patients with established nonunion of a long bone (18 tibias, 15 femurs, 9 humerus, 6 radii, and 12 ulnae) were included in this study, comprising 31 males and 29 females, ranging from 18 to 60 years old. Patients with bone nonunion were separated into two groups: PRP alone (Monotherapy group) and those treated with PRP combined with ESW (Combined treatment group). The two groups were compared to assess the therapeutic benefits, callus development, local problems, bone healing time, and Johner Wruhs functional classification of operated limbs. RESULTS: Fifty-five patients were followed up, 5 patients were lost to follow-up, two in the PRP group and three in the PRP+ESW group, the follow-up time varied from 6 to 18 months, with an average of 12.7±5.2 months. At 8, 12, 16, 20, and 24 weeks following intervention, the callus score in the monotherapy group was significantly lower than in the combined treatment group (p<0.05). Both groups had no swelling and infection in the soft tissue of the nonunion operation site. In the PRP+ESW group, the fracture union rate was 92.59% and the healing time was 16.3±5.2 weeks. In the PRP group, the fracture union rate was 71.43% and the healing time was 21.5±3.7 weeks. The clinical healing time of the monotherapy group was significantly longer than the combined treatment group (p<0.05). All the nonunion patients with no signs of healing were treated with revision surgery. The excellent and good rate of Johner-Wruhs functional classification of affected limbs in the monotherapy group was significantly lower than in the combined treatment group (p<0.05). CONCLUSION: PRP combined with ESW has a certain synergistic effect in treating aseptic nonunion after fracture surgery. It can significantly improve the formation of new bone, it is a minimally invasive and effective strategy to treat aseptic nonunion in a clinical setting. LEVEL OF EVIDENCE: III, retrospective, single-centre, case-control study.

Negative pressure wound therapy improves bone regeneration by promoting osteogenic differentiation via the AMPK-ULK1-autophagy axis.

Deficient bone regeneration causes bone defects or nonunion in a substantial proportion of trauma patients that urges for novel therapies. To develop a reliable therapy, we investigated the effect of negative pressure wound therapy (NPWT) on bone regeneration in vivo in a rat calvarial defect model. Negative pressure (NP) treatment in vitro was mimicked to test its effect on osteoblast differentiation in rat mesenchymal stem cells (MSCs) and MC3T3-E1 cells. Transcriptomic analyses, pharmaceutical interventions, and shRNA knockdowns were conducted to explore the underlying mechanism and their clinical relevance was investigated in samples from patients with nonunion. The potential application of a combined therapy of MSCs in hydrogels with negative pressure was tested in the rat critical-size calvarial defect model. We found that NPWT promoted bone regeneration in vivo and NP treatment induced osteoblast differentiation in vitro. NP induced osteogenesis via activating macroautophagy/autophagy by AMPK-ULK1 signaling that was impaired in clinical samples from patients with nonunion. More importantly, the combined therapy involving MSCs in hydrogels with negative pressure significantly improved bone regeneration in rat critical-size calvarial defect model. Thus, our study identifies a novel AMPK-ULK1-autophagy axis by which negative pressure promotes osteoblast differentiation of MSCs and bone regeneration. NPWT treatment can potentially be adopted for therapy of bone defects.Abbreviations: ADP, adenosine diphosphate; AICAR/Aic, acadesine; ALP, alkaline phosphatase; ALPL, alkaline phosphatase, biomineralization associated; AMP, adenosine monophosphate; AMPK, AMP-activated protein kinase; ARS, alizarin red S staining; ATG7, autophagy related 7; ATP, adenosine triphosphate; BA1, bafilomycin A1; BGLAP/OCN, bone gamma-carboxyglutamate protein; BL, BL-918; BS, bone surface; BS/TV, bone surface per tissue volume; BV/TV, bone volume per tissue volume; C.C, compound C; CCN1, cellular communication network factor 1; COL1A1, collagen type I alpha 1 chain; COL4A3, collagen type IV alpha 3 chain; COL4A4, collagen type IV alpha 4 chain; COL18A1, collagen type XVIII alpha 1 chain; CQ, chloroquine; GelMA, gelatin methacryloyl hydrogel; GO, Gene Ontology; GSEA, gene set enrichment analysis; HIF1A, hypoxia inducible factor 1 subunit alpha; HPLC, high-performance liquid chromatography; ITGAM/CD11B, integrin subunit alpha M; ITGAX/CD11C, integrin subunit alpha X; ITGB1/CdD9, integrin subunit beta 1; KEGG, Kyoto Encyclopedia of Genes and Genomes; MAP1LC3B/LC3B, microtubule associated protein 1 light chain 3 beta; micro-CT, microcomputed tomography; MSCs, mesenchymal stem cells; MTOR, mechanistic target of rapamycin kinase; NP, negative pressure; NPWT, negative pressure wound therapy; PRKAA1/AMPKα1, protein kinase AMP-activated catalytic subunit alpha 1; PRKAA2, protein kinase AMP-activated catalytic subunit alpha 2; PTPRC/CD45, protein tyrosine phosphatase receptor type C; ROS, reactive oxygen species; RUNX2, RUNX family transcription factor 2; SBI, SBI-0206965; SPP1/OPN, secreted phosphoprotein 1; THY1/CD90, Thy-1 cell surface antigen; SQSTM1, sequestosome 1; TGFB3, transforming growth factor beta 3; ULK1/Atg1, unc-51 like autophagy activating kinase 1.

Preoperative contrast-enhanced ultrasound (CEUS) of long bone nonunions reliably predicts microbiology of tissue culture samples but not of implant-sonication.

INTRODUCTION: Bacterial infection in the context of fracture repair remains a severe complication in trauma surgery and may result in long bone nonunion. Since treatment options for aseptic and infected nonunions vary greatly, diagnostic methods should ideally differentiate between these two entities as accurately as possible. Recently, contrast-enhanced ultrasound (CEUS) has been introduced as a preoperative imaging technique to evaluate hypervascularity at the fracture site as sign of bacterial infection. HYPOTHESIS: Preoperative CEUS predicts results of microbiological evaluation obtained either by culture of tissue samples or by analyzing the sonication fluid following removal and sonication of the implant. PATIENTS AND METHODS: Over the course of 6 months, 26 patients with long bone nonunions were included in this study. Patients' clinical data were evaluated. Tissue samples were collected intraoperatively and examined by standard microbiological techniques. The sonication method was applied to removed implants. Additionally, 1-3 days before surgery, CEUS was performed to determine hypervascularity at the nonunion site as a possible parameter for infection. RESULTS: Culture of tissue samples indicated infection in 50% of cases and implant sonication in 57.7% of cases. However, there was merely a fair agreement (κ=0.231) between these two diagnostic methods. CEUS predicted results of tissue culture reliably (sensitivity 92.3% and specificity 100%), whereas implant sonication showed no significant correlations with results from CEUS. Hypertrophic and atrophic nonunions were evaluated separately to determine possible differences in vascularity. We found that contrast peak enhancement of CEUS was similar in atrophic and hypertrophic nonunions with positive culture of tissue samples. Both differed significantly from culture negative cases (p=0.0016 and 0.0062). Results of implant-sonication positive or negative cases in atrophic and hypertrophic nonunions, however, were less clear and could be misleading. DISCUSSION: We were able to confirm CEUS as a valuable preoperative diagnostic tool that reliably predicts microbiology of tissue culture samples, but not of implant sonication. LEVEL OF EVIDENCE: I; diagnostic study.

Application of autologous platelet-rich plasma in the treatment of postoperative bone nonunion for long bone shaft fractures during and after operation / 中国输血杂志

【Objective】 To explore the clinical effects of autologous platelet-rich plasma (PRP) in the treatment of postoperative bone nonunion for long bone shaft fractures during operation and after operation. 【Methods】 A total of 34 patients with postoperative bone nonunion for long bone shaft fracture, who were admitted and cured in the Orthopedics Department of our hospital from January 2019 to June 2020, were selected. They were randomly divided into the experimental group(n=17) and control group(n=17). Individuals in the control were treated with autologous iliac bone alone., while the experimental group were treated with autologous iliac bone graft plus autologous PRP during and after operation. After surgery, the autogenous PRP was accurately injected with ultrasound guidance every 7 days (5 mL/person, 4 occasions in total). The clinical healing time of the fracture, the grading of callus formation and the functional rehabilitation level of limbs on the affected side at different time were observed in both groups. 【Results】 All 34 patients were followed up. In the experimental group and the control group, the clinical healing time (month) of the fracture was (5.03±1.24) vs (6.91±1.41), P<0.05. The healing rate of the fracture for 6 months and 9 months was 94%(16/17)vs 59%(10/17)and 94%(16/17)vs 82%(14/17), respectively (P<0.05). The grading of callus formation within 3, 6 and 9 months was (2.11±0.69) vs (1.53±0.80), (3.06±0.90) vs (2.59±0.87) and (3.82±0.73) vs (3.35±0.86), respectively (P<0.05). The acceptance rate of functional rehabilitation of limbs on the affected side was 82.35%(14/17)vs 76.47%(13/17), P<0.05. 【Conclusion】 The application of autologous PRP in the treatment of postoperative bone nonunion for long bone shaft fractures during operation and after operation can achieve good clinical treatment.

Analysis of Risk Factors for Non-union After Surgery for Limb Fractures: A Case-Control Study of 669 Subjects.

Objective: The purpose of this study was to analyze the risk factors for limb fracture non-union in order to improve non-union prevention and early detection. Methods: A total of 223 patients with non-union after surgery for limb fractures performed at our institution from January 2005 to June 2017 were included as the case group, while a computer-generated random list was created to select 446 patients with successful bone healing after surgery for limb fractures who were treated during the same period as the control group, thus achieving a ratio of 1:2. The medical records of these patients were reviewed retrospectively. Age, sex, body mass index, obesity, smoking, alcohol, diabetes, hypertension, osteoporosis, fracture type, multiple fractures, non-steroidal anti-inflammatory drugs (NSAIDs) use, delayed weight bearing, internal fixation failure, and infection data were analyzed and compared between the two groups. A multivariate logistic regression model was constructed to determine relevant factors associated with non-union. Results: After comparison between two groups by univariate analysis and multivariate logistic regression, we found some risk factors associated that osteoporosis (odds ratio [OR] = 3.16, 95% confidence interval [CI]: 2.05-4.89, p < 0.001), open fracture (OR = 2.71, 95%CI: 1.72-4.27, p < 0.001), NSAIDs use (OR = 2.04, 95%CI: 1.24-3.37, p = 0.005), delayed weight bearing (OR = 1.72, 95%CI: 1.08-2.74, p = 0.023), failed internal fixation (OR = 5.93, 95%CI: 2.85-12.36, p < 0.001), and infection (OR = 6.77, 95%CI: 2.92-15.69, p < 0.001) were independent risk factors for non-union after surgery for limb fractures. Conclusions: Osteoporosis, open fracture type, NSAIDs use, delayed weight bearing, failed internal fixation, and infection were found to be the main causes of bone non-union; clinicians should, therefore, take targeted measures to intervene in high-risk groups early.

Effect of Bone Morphogenetic Protein-2 in the Treatment of Long Bone Non-Unions.

BACKGROUND: Delayed fracture healing continues to cause significant patient morbidity and an economic burden to society. Biological stimulation of non-unions includes application of recombinant bone morphogenetic protein-2 (rhBMP-2). However, rhBMP-2 use continues to be a matter of controversy as literature shows scarce evidence for treatment effectiveness. QUESTIONS: The objective of this study was to evaluate the effectiveness of rhBMP-2 treatment on long bone non-unions measuring union rate and time to union. Furthermore, we assess risk factors for treatment failure. METHODS AND PATIENTS: A total of 91 patients with non-unions of long bones were treated with rhBMP-2 (n = 72) or standard care without BMP (n = 19) at our institution. Patient characteristics, comorbidities, nicotine consumption, and complications were recorded. Bone healing was assessed by plane X-rays and clinical examination. Patients were followed up with for 24 months. RESULTS: Overall, there was significantly faster bone healing after rhBMP-2 application compared to the no-BMP group (p < 0.001; HR = 2.78; 95% CI 1.4-5.6). Union rates differed significantly between rhBMP-2 compared to the no-BMP group (89% vs. 47%; p < 0.001). At the humerus, there was neither a significantly higher union rate in the rhBMP-2 (83%) compared to the no-BMP group (50%) (p = 0.26; n = 12) nor a faster bone healing with a median time of 9 months in both groups (HR = 2.01; 95% CI 0.49-8.61; p = 0.315). The 33 femora treated using rhBMP-2 healed significantly faster than 9 femora in the no-BMP group (HR = 2.93; 95% CI 1.00-8.4; p = 0.023) with significant differences in union rate with 85% and 44%, respectively (p = 0.022). Regarding tibia non-unions, 25 out of 27 (93%) healed with a median of 9 months after rhBMP-2 application with no significant difference in the no-BMP group (33%) in time to union (p = 0.097) but a significantly higher union rate (p = 0.039). There was no effect of comorbidities, age, sex, soft tissue damage, or nicotine use on time to union, union rate, or secondary interventions. CONCLUSION: Consistent with the literature, overall, significantly higher union rates with reduced time to union were achieved after rhBMP-2 application. Femoral and tibial non-unions in particular seem to profit from rhBMP-2 application.

Clinical efficacy of bone transport technology in Chinese older patients with infectious bone nonunion after open tibial fracture.

OBJECTIVE: This study was designed for the first time to analyze clinical efficacy of bone transport technology in Chinese older patients with infectious bone nonunion after open tibial fracture. METHODS: This study retrospectively analyzed 220 older patients with infectious bone nonunion after open tibial fracture. There were 110 patients receiving bone transport technology (Group A) and 110 patients receiving membrane induction technique with antibiotic bone cement (Group B). RESULTS: There were 164 male patients and 56 female patients, with an age range of 65 to 71 years and an average age of 67 ± 1.3 years. Traffic accident, high-fall injury and crush injury account for 45.5, 27.7 and 26.8%, respectively. Age, gender, histories, causes and fracture location had no significant difference between the two groups (P > 0.05 for all). Operation time in the Group A was significantly shorter than that in the Group B (P < 0.05). Linear and positional alignment (70.9 vs. 57.3), American Knee Society knee function score (167.7 ± 14.9 vs. 123.8 ± 15.7), Baird-Jackson ankle function score (89.9 ± 3.5 vs. 78.4 ± 4.9), bone healing index (43.0 ± 2.0 vs. 44.3 ± 3.0) and clinical recovery (8.2 vs. 4.5) of patients in the Group A were significantly better than those in the Group B (P < 0.05 for all). Wound infection in the Group A (7.3%) was significantly less than that in the Group B (16.4%; P < 0.05). There were neither a neurovascular complication nor a recurrence of infection in the two groups. CONCLUSION: Bone transport technology achieved better knee and ankle joint function recovery and superior bone healing and clinical efficacy than membrane induction technique with antibiotic bone cement, suggesting that bone transport technique is worthy of extensive promotion to improve clinical condition of older patients with infectious bone nonunion after open tibial fracture.