Mid-term efficacy and safety of Escherichia coli-derived rhBMP-2/hydroxyapatite carrier in lumbar posterolateral fusion: a randomized, multicenter study.

PURPOSE: This study aimed to evaluate the mid-term efficacy and safety of Escherichia coli-derived bone morphogenetic protein-2 (E.BMP-2)/hydroxyapatite (HA) in lumbar posterolateral fusion (PLF). METHODS: This multicenter, evaluator-blinded, observational study utilized prospectively collected clinical data. We enrolled 74 patients who underwent lumbar PLF and had previously participated in the BA06-CP01 clinical study, which compared the short-term outcomes of E.BMP-2 with an auto-iliac bone graft (AIBG). Radiographs and CT scans were analyzed to evaluate fusion grade at 12, 24, and 36 months. Visual analog scale (VAS), Oswestry disability index (ODI), and Short Form-36 (SF-36) scores were measured preoperatively and at 36 months after surgery. All adverse events in this study were assessed for its relationship with E.BMP-2. RESULTS: The fusion grade of the E.BMP-2 group (4.91 ± 0.41) was superior to that of the AIBG group (4.25 ± 1.26) in CT scans at 36 months after surgery (p = 0.007). Non-union cases were 4.3% in the E.BMP-2 and 16.7% in the AIBG. Both groups showed improvement in pain VAS, ODI, and SF-36 scores when compared to the baseline values, and there were no statistically significant differences between the two groups. No treatment-related serious adverse reactions were observed in either group. No neoplasm-related adverse events occurred in the E.BMP-2 group. CONCLUSIONS: The fusion quality of E.BMP-2/HA was superior to that of AIBG. E.BMP-2/HA showed comparable mid-term outcomes to that of AIBG in terms of efficacy and safety in one-level lumbar PLF surgery.

Gas formation and biological effects of biodegradable magnesium in a preclinical and clinical observation.

Magnesium alloys are biodegradable metals receiving increasing attention, but the clinical applications of these materials are delayed by concerns over the rapid corrosion rate and gas formation. Unlike corrosion, which weakens mechanical properties, the gas formation issue has received little attention. Therefore, we evaluated the gas formation and biological effects for Mg implants through preclinical (immersed in Earle's balanced salt solution and in vivo) and clinical studies. The immersion test examined the gas volume and composition. The in vivo study also examined gas volume and histological analysis. The clinical study examined the gas volume and safety after Mg screw metatarsal fixation. Gas was mainly composed of H2, CO and CO2. Maximum volumes of gas formed after 5 days for in vivo and 7 days in clinical study. Within the clinical examination, two superficial wound complications healed with local wound care. Osteolytic lesions in the surrounding metaphysis of the Mg screw insertion developed in all cases and union occurred at 3 months. Mg implants released gas with variable volumes and composition (H2, CO, and CO2), with no long-term toxic effects on the surrounding tissue. The implants enabled bone healing, although complications of wound breakdown and osteolytic lesions developed.

Prognostic factors in distractive extension injuries of the subaxial cervical spine.

BACKGROUND: The subaxial spine has high risk of fatal damage by trauma and thereby requires more accurate and aggressive treatment. For the proper treatment and predicting the prognosis, the evaluation to reveal the risk factors for the prognosis is important. We analyzed the various factors contributing to the prognosis in distractive extension injuries of the subaxial cervical spine. METHODS: The study included 103 patients who were diagnosed as distractive extension injury of subaxial cervical spine. We evaluate the patient age, sex, cause of injury, initial neurological impairment, number and portion of injured segment, spinal stenosis, extent of soft tissue damage, ossification of the posterior longitudinal ligament, and degenerative spondylosis as a prognostic factor. To analyze the factor related with prognosis, the subjects were divided into group A, in which patients had neurological recovery ≥grade 2 on the ASIA scale or showed normal in final follow-up and group B, in which patients have no neurological recovery. RESULTS: Prognosis was not associated with age, sex, and cause of injury (P = 0.677, 0.541, and 0.965, respectively). Prognosis was poor in cases with spinal stenosis (P = 0.009), soft tissue damage ≥grade 3 on magnetic resonance imaging (MRI) (P = 0.002), or severe neurological impairment (P ≤ 0.001). Logistic regression analysis also showed that prognosis was poor in cases with spinal stenosis (OR 5.03; 95% CI 1.20-16.93), soft tissue damage ≥grade 3 on MRI (OR 7.63; 95% CI 1.86-31.34), or severe neurological impairment (ASIA C, D, OR 0.59, 95% CI 0.14-2.41; ASIA A, B, OR 18.43, 95% CI 1.64-207.69). CONCLUSION: The prognosis of patients with distractive extension injury of the subaxial cervical spine was poor in cases with spinal stenosis, severe soft tissue damage in MRI findings or severe initial neurological impairment.

Is OPLL-induced canal stenosis a risk factor of cord injury in cervical trauma?

The purpose of this study is to identify the relationship between trauma severity and the degree of cord injury in patients with ossification of posterior longitudinal ligament (OPLL). Four-hundred-one patients were classified into Group A (OPLL(+)), Group B (spinal stenosis (+) and OPLL(-)), and Group C (OPLL (-) and spinal stenosis(-)). Trauma severity and neurological injury severity were compared according to presence of OPLL and spinal stenosis. OPLL was associated with a higher incidence of neurological injury with statistical significance (p = 0.002), whereas spinal stenosis did not (p = 0.408). With Group B+C (no OPLL group) in M (minimal) trauma group as baseline, Group A in M trauma group showed about 5 times, and Group A in S (severe) trauma group showed about 16 times as many cord injury. Patients with OPLL more frequently sustained spinal cord injury from minimal trauma.

Huge hypertrophic scar secondary to chronic ingrown toe nail mimicking tumor: A case report.

RATIONALE: A huge hypertrophic scar formation secondary to chronic ingrown toe nail mimicking tumor is a rare disease. It is not only causing concerns cosmetically, but also hindering normal daily activities physically and socially. In this paper, we present an unusual case of bilateral ingrown nails with different phases. One resulted in a large hypertrophic scar caused by stimulation from secondary to chronic ingrown nail. PATIENT CONCERNS AND DIAGNOSIS: A 44-year-old man with a huge mass (7 × 4 × 8.5 cm) in his right great toe and inflamed ingrown nail in his left great toe visited the clinic. The mass in the right toe showed an irregular and bizarre shape with a stellate ulcer (2 × 2 cm) at the distal end. After removing an ingrown nail 3 years ago with minor repetitive trauma, self-managed wound has grown into a tumor-like mass, resulting in intolerable discomfort. In gross appearance, a stalk appeared to originate from the lateral side of the nail bed with the ingrown nail in the great toe showing inflamed medial and lateral gutter and causing redness and tenderness. Huge hypertrophic scar formation secondary to chronic ingrown toe nail mimicking tumor is a rare disease that is not only causing a cosmetic concern, but also hindering normal daily activities physically and socially. INTERVENTION AND OUTCOMES: Excisional biopsy was performed for both great toes. Biopsy confirmed chronic ulcerative inflammation with a hypertrophic scar. The resection site healed and persisted well at 12 months after surgery. CONCLUSION: Our unusual case suggests that the natural course of an untreated ingrown toe nail may result in hypertrophic scar extending far to mimic tumorous conditions.

Short-Term Outcomes of Arthroscopic Treatment of Freiberg Disease.

BACKGROUND: Surgical treatment for Freiberg disease (also known as avascular necrosis of the metatarsal head) has not been completely defined. This retrospective study evaluated short-term outcomes after arthroscopic treatment of Freiberg disease. METHODS: From 2015 to 2019, 13 patients (15 feet) diagnosed as having Freiberg disease were enrolled for arthroscopic surgery. Feet were divided based on the Smillie classification system (two with stage I, eight with stage II, three with stage III, one with stage IV, and one with stage V). Arthroscopic interventions, including synovectomy, debridement, chondroplasty, microfracture, and loose body removal, were performed without considering the Smillie classification stage. Radiologic outcomes were evaluated by radiography (preoperatively and 3, 6, and 12 months postoperatively) and magnetic resonance imaging (preoperatively and 12 months postoperatively). Clinical outcomes were evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) lesser metatarsophalangeal (MTP)-interphalangeal score and the visual analog scale (VAS) score. The MTP joint range of motion was measured using a goniometer preoperatively and postoperatively. RESULTS: Radiologic studies showed no evidence of osteonecrosis progression in postoperative 12-month radiographs of any patients. Postoperative 12-month magnetic resonance images showed reduction of bone marrow edema, irregularity of subchondral bone, and cartilage defects in all patients. Significant improvements in AOFAS and VAS scores occurred at all postoperative time points compared with preoperative scores (P = .001). The MTP joint range of motion also showed improvement at last follow-up (P = .001). CONCLUSIONS: Arthroscopic surgery for Freiberg disease showed excellent clinical outcomes, MTP joint range of motion, and short-term outcomes regardless of stage (Smillie classification) in radiologic evaluation.

Use of autogenous bone graft compared with RhBMP in high-risk patients: a comparison of fusion rates and time to fusion.

STUDY DESIGN: A retrospective study. OBJECTIVE: To evaluate whether recombinant human bone morphogenetic protein (rhBMP-2) can improve fusion rates and time to fusion in high-risk patients when compared with autograft in lumbar posterolateral fusion. SUMMARY OF BACKGROUND DATA: The use of rhBMP-2 in the general population for posterolateral fusion has resulted in relatively good reported outcomes; however, it is currently considered "off-label" use. Few studies, however, have determined the outcomes of rhBMP-2 when used in patients with numerous risk factors for a pseudarthrosis. METHODS: One hundred ninety-five patients were divided into 4 groups depending on fusion material and the presence/absence of fusion-related risk factors for nonunions; group A was defined as rhBMP-2 used in the presence of high-risk factors (FRRF), group B was defined as rhBMP-2 used in the absence of FRRF, group C was defined as autograft used in the presence of FRRF, and group D was defined as autograft used in the absence of FRRF. The time to fusion, fusion rate were compared between each group. RESULTS: The time to fusion was significantly faster in group B than in group D in patients with no history of smoking (P<0.05), hypertension (P<0.01), or other significant comorbidity (P<0.05). The time to complete fusion was also significantly faster in group B than in group D in patients under the age of 65 (P<0.05), patients undergoing primary surgery (P<0.05), single-level surgery (P<0.01), no smoking history (P<0.05), no diabetes mellitus (P<0.01), no hypertension (P=0.001), no osteoporosis (P<0.01), and no significant comorbidity (P<0.01). Although the fusion rate was higher in group B than in group D, with the exception of sex and single-level surgery, there were no significant differences between groups B and D. Although initial fusion mass and time to solid fusion was faster in group A than in group C, there were no significant differences between groups A and C. In addition, fusion rates were higher in group C than in group A, looking at all factors except revision surgery, but the differences were not statistically significant. CONCLUSIONS: With relative low dosage of rhBMP-2 compared with the dose used in Food and Drug Administration trial, in patients without fusion-related risk factors, rhBMP-2 may lead to acceptable fusion rates and faster fusion time when compared with autograft. Therefore, rhBMP-2 may serve as an acceptable alternative to autogenous bone graft in patients without fusion-related risk factors undergoing instrumented posterolateral lumbar fusions. When compared with patients with fusion-related risk factors, the use of rhBMP-2 was comparable with autograft but was not sufficient to overcome all aspects of the weakened osteoinductive capacity encountered in patients with these risk factors.

Short-term results of endoscopic calcaneoplasty and retrocalcaneal bursectomy for insertional Achilles tendinopathy.

Although open surgery has traditionally been used as a surgical treatment for insertional Achilles tendinopathy, there is a possibility of serious complications (avulsion, scarring, contracture, sensory changes, and infection) due to the anatomical characteristics of the area. Endoscopic surgery has some advantages due to the smaller incision needed. The purpose of this study was to evaluate the effectiveness of endoscopic surgery in insertional Achilles tendinopathy. Twelve patients (15 feet) who underwent endoscopic surgery between 2015 and 2021 were included in this study. Clinical results were evaluated before and after surgery by visual analog scale (VAS) and, Ogilvie-Harris scores and complications. For radiological evaluation, the Fowler-Philip angle, and positive parallel pitch line were measured. VAS scores decreased from 7.6 preoperatively to 2.3 at the last postoperative follow-up, and Ogilvie-Harris values showed excellent results in 5 cases, good results in 8 cases, and fair results in 2 cases. In the radiographic results, there was no bone prominence above the Pavlov calcaneus pitch line in any case, and the Fowler-Philip angle decreased from an average of 57.5 degrees to 50.2 degrees. Only 1 patient underwent reoperation due to the recurrence of symptoms 33 months after the first surgery. After the second operation, the VAS score decreased to 3 points. No complications occurred. Endoscopic surgery is an effective and minimally invasive procedure, showing fewer complications and similar satisfaction as the open procedure. Therefore, it can be a good treatment option for patients with insertional Achilles tendinopathy as it provides the patient with a quick return to daily life.

Bone Morphogenetic Protein 2 Promotes Bone Formation in Bone Defects in Which Bone Remodeling Is Suppressed by Long-Term and High-Dose Zoledronic Acid.

The use of long-term and high-dose bisphosphate is associated with severely suppressed bone turnover and the delayed union of fractures. However, therapeutic methods to overcome the negative effects of bisphosphonate use are lacking. Bone morphogenetic proteins (BMPs) are powerful osteoinductive proteins. The development of the delivery system using BMP has been verified to have an excellent effect on fracture healing and the enhancement of osteointegration. We hypothesized that BMPs had similar effects as autografts in patients with decreased bone healing potential due to long-term bisphosphonate treatment. Forty rats were divided into the following four groups depending upon the materials implanted into the femoral defect after ten weeks of bisphosphonate (zoledronic acid) injections: Group I: absorbable collagen sponge (control); group II: demineralized freeze-dried bone graft; group III: autogenous bone graft; and group IV: rhBMP-2 with an absorbable collagen sponge. Radiographic union, micro-computed tomography (CT) analysis, manual palpation, and histologic analysis were evaluated. The radiographic union rate, manual union rate, and micro-CT bone volume in groups III and IV were significantly higher than those in groups I and II. Groups III and IV showed similar results to each other. Although the amount of immature bone in the BMP-treated group was large, the effect was similar to that of autografts in the bone defect model in which bone turnover was severely reduced by bisphosphonate treatment. BMP might be a good substitute for autografts in patients with decreased bone healing potential due to long-term bisphosphonate treatment.

Is Subclassification by Number of Fracture Fragments Necessary for Sanders Type IV Calcaneal Fractures?

BACKGROUND: The Sanders classification is a widely used method for classifying calcaneal fractures. Type IV fractures (>4 fragments) are known to vary in the number of fracture fragments. However, all relevant cases are classified as type IV irrespective of the number of fragments. We investigated the need for evaluation of postoperative prognoses based on radiologic factors and subtypes of Sanders classification type IV fractures. METHODS: Fifty-six Sanders type IV calcaneal fractures were enrolled between 2010 and 2018. Patients were divided into two groups according to the number of fragments: four fragments (group 1) and more than four fragments (group 2). Radiologic evaluation was performed using a postoperative recovery percentage calculated from postoperative reduction of the Böhler angle, Gissane angle, and vertical height. Radiologic evaluation was divided into two groups according to postoperative recovery: good and bad recovery groups. American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score and visual analog scale (VAS) score were used for clinical outcome evaluation. RESULTS: There was no significant difference in AOFAS ankle-hindfoot score (P = .909) or VAS score (P = .963) between groups 1 and 2. However, there was a significant (P = .001) difference in AOFAS ankle-hindfoot score or VAS score between good and bad recovery groups. CONCLUSIONS: Clinical results of Sanders type IV fractures were not related to the number of bone fragments but to the degree of injury to the Böhler angle, Gissane angle, and vertical height. Therefore, subtype classification of type IV calcaneal fractures is superfluous, and it is important to try to restore these parameters during surgery.

Continuous detrimental activity of intra-articular fibrous scar tissue in correlation with posttraumatic ankle osteoarthritis.

Posttraumatic osteoarthritis is primarily characterized by articular cartilage destruction secondary to trauma or fracture events. Even while intra-articular scar tissue can be observed following ankle fractures, little is known about its nature and molecular events linking its biological activity and cartilage deterioration. Here, we investigated scar tissue's histological and molecular characteristics, and its relationship with localized articular cartilage alterations consistent with early osteoarthritic degeneration. Intra-articular scar tissues from sixty-two patients who underwent open reduction internal fixation for ankle fracture were obtained at hardware removal time (6-44 months after fracture). Histological analysis demonstrated that scar tissue has the nature of fibrosis with fibrous tissue hyperplasia, fibroblast proliferation, and chondrometaplasia. These fibrous scar tissues showed overexpressed pro-inflammatory cytokines and high mRNA expression levels of osteoarthritis-related markers (cytokines, chemokines, and enzymes) compared to the normal synovium. Furthermore, those transcriptional levels were significantly correlated with the grade of talar chondral degeneration. Our findings suggest that following an ankle fracture, the intra-articular fibrous scar tissue exhibits high catabolic and inflammatory activity, which has a long-lasting negative impact correlated to cartilage deterioration in the development of posttraumatic osteoarthritis.

Effect of Bone Morphogenetic Protein-2 Combined With Microfracture for Osteochondral Defect of the Talus in a Rabbit Model.

BACKGROUND: Osteochondral defects of the talus can be effectively treated using microfracture, which is technically safe, accessible, and affordable. However, fibrous tissue and fibrocartilage comprise the majority of tissue repairs resulting from these procedures. These tissue types lack the mechanical characteristics of native hyaline cartilage and might significantly contribute to the decline in long-term outcomes. Recombinant human-bone morphogenetic protein-2 (rhBMP-2) has been shown to promote matrix synthesis and increase cartilage formation, thus enhancing chondrogenesis in vitro. PURPOSE: This study aimed to evaluate the treatment ability of combining rhBMP-2 with microfracture in rabbit talus osteochondral defect. STUDY DESIGN: Controlled laboratory study. METHODS: A full-thickness chondral defect (3 × 3 × 2 mm) was constructed in the center talar dome of 24 New Zealand White male rabbits, which were then divided into 4 groups of 6. Each group received the appropriate treatment: group 1 (control; no treatment of defect), group 2 (microfracture treatment), group 3 (rhBMP-2/hydroxyapatite treatment), and group 4 (microfracture combined with rhBMP-2/hydroxyapatite treatment). Animals were sacrificed at 2, 4, and 6 weeks postoperatively. The International Cartilage Regeneration & Joint Preservation Society macroscopic score, which considers the degree of defect repair, the integration to the border zone, and the macroscopic appearance, was used to assess the repaired tissue's macroscopic appearance. Subchondral bone regeneration in defects was analyzed using micro-computed tomography, and the histological findings were graded using a modified version of the Wakitani scoring system for osteochondral repair. RESULTS: At 2, 4, and 6 weeks, micro-computed tomography analysis revealed that groups 3 and 4 exhibited subchondral bone healing that was more significantly improved compared with groups 1. No sample showed excessive bone growth from the subchondral bone area. According to macroscopic and histological results, group 4 showed higher-quality cartilage and more accelerated cartilage regeneration than the other groups over time. CONCLUSION: These findings show that osteochondral defect repair in a rabbit talus model could be effectively accelerated and improved by combining rhBMP-2 with microfracture. CLINICAL RELEVANCE: Using rhBMP-2 in combination with microfracture may enhance the repair of talar osteochondral lesions.

Recovery of CNS pathway innervating the sciatic nerve following transplantation of human neural stem cells in rat spinal cord injury.

Stem cell research has been attained a greater attention in most fields of medicine due to its potential for many incurable diseases through replacing or helping the regeneration of damaged cells or tissues. Here, we demonstrated the functional recovery and structural connection of the central nervous system pathway innervating the sciatic nerve after total transection of the spinal cord followed by the transplantation of human neural stem cells (hNSC) in the injured rat spinal cord site. The limb function of hNSC-treated group recovered dramatically compared with that in the sham group by Basso-Beattie-Bresnahan (BBB) scores. Transplanted hNSC differentiated into astrocytes and neurons in the injured site. In addition, immunohistochemistry for growth-associated protein 43 showed axonal regeneration in the injured spinal cord site. The pseudorabies viral-Ba (PRV-Ba) tracing method revealed that transplanted hNSC and their differentiated neurons showed positive labeling after sciatic nerve injection. In addition, the PRV-Ba labeling was also observed in several nuclei in the brain innervating the sciatic nerve. This result implies that the rat CNS motor pathway could be reconstructed by hNSC transplantation, and it may contribute to the functional recovery of the limb.

Efficacy of multilevel anterior cervical discectomy and fusion versus corpectomy and fusion for multilevel cervical spondylotic myelopathy: a minimum 5-year follow-up study.

PURPOSE: We evaluated radiologic and clinical outcomes to compare the efficacy of anterior cervical discectomy and fusion (ACDF) and anterior corpectomy and fusion (ACCF) for multilevel cervical spondylotic myelopathy (CSM). METHODS: A total of 40 patients who underwent ACDF or ACCF for multilevel CSM were divided into two groups. Group A (n = 25) underwent ACDF and group B (n = 15) ACCF. Clinical outcomes (JOA and VAS scores), perioperative parameters (length of hospital stay, blood loss, operation time), radiological parameters (fusion rate, segmental height, cervical lordosis), and complications were compared. RESULTS: Both group A and group B demonstrated significant increases in JOA scores and significant decreases in VAS. Patients who underwent ACDF experienced significantly shorter hospital stays (p = 0.031), less blood loss (p = 0.001), and shorter operation times (p = 0.024). Both groups showed significant increases in postoperative cervical lordosis and achieved satisfactory fusion rates (88.0 and 93.3%, respectively). There were no significant differences in the incidence of complications among the groups. CONCLUSIONS: Both ACDF and ACCF provide satisfactory clinical outcomes and fusion rates for multilevel CSM. However, multilevel ACDF is associated with better radiologic parameters, shorter hospital stays, less blood loss, and shorter operative times.

Three- and four-level anterior cervical discectomy and fusion with a PEEK cage and plate construct.

INTRODUCTION: Three- or four-level anterior cervical discectomy and fusion with autograft and plate fixation have demonstrated relatively good fusion rates and outcomes, but donor site morbidity and the limitations of autograft harvest remain problematic. The purpose of this study is to assess the radiographic and clinical outcomes of three- or four-level anterior cervical discectomy and fusion with a PEEK cage and plate construct. METHODS: This retrospective review included 43 consecutive patients who underwent three- or four-level anterior cervical discectomy and fusion with a PEEK cage and plate construct (three level: 39 cases, four level: 4 cases). The fusion rate, time to fusion, Cobb angle and disc height were assessed radiographically. Clinical outcomes were evaluated with the VAS, NDI, and SF36 scores. Complications were also recorded. RESULTS: Solid fusion was achieved in all the patients, and mean time to fusion was 13.7 ± 5.1 weeks. The postoperative Cobb angle, lordotic angle, and disc height (5.6°, 10.5° and 3.15 mm, respectively) increased significantly compared to preoperative values (p = 0.038, p = 0.032, and p = 0.0004, respectively), and these improvements were maintained through final follow-up. The postoperative NDI (17.2), VAS (2.8), and SF36 (13.1) scores increased significantly compared to the preoperative scores (p = 0.026, p = 0.0007 and p = 0.041, respectively). Complications included three cases of respiratory difficulty, four cases of dysphagia and one case of hoarseness. There were no cases of donor site morbidity. CONCLUSIONS: Three- or four-level anterior cervical discectomy and fusion with a PEEK cage, and plate construct provide good clinical and radiographic outcomes including high fusion rates, low complication rates, low donor site morbidity, and good maintenance of the lordotic angle and disc height in the treatment of multilevel cervical spondylosis.

Pediatric odontoid fracture causing Brown-Sequard syndrome: a case report.

An odontoid fracture leading to Brown-Sequard syndrome (BSS) is an uncommon condition with only seven cases reported to date. To our knowledge, there are no reports of occurrence in paediatric patients. We report a paediatric odontoid fracture leading to Brown-Sequard syndrome (BSS) with satisfactory recovery following surgical treatment. Odontoid fractures may lead to Brown-Sequard syndrome in cases of high-energy trauma in paediatric patients. Direct anterior screw fixation may be a treatment of choice in paediatric odontoid fractures of the comminuted, displaced type when occurring in conjunction with neurologic injuries.

Intraosseous Gouty Osteolytic Lesion in Calcaneus.

Tophaceous gout often occurs in soft tissues, and gouty invasion to the bone is rare. To date, only one case of isolated intraosseous gouty invasion to the calcaneus has been reported. We report here a rare case of an intraosseous calcaneal gouty cystic lesion treated with curettage and allogenous and autogenous bone graft. Satisfactory function and pain relief were obtained at 12-month follow-up, without any evidence of recurrent disease.

Multifocal Osteonecrosis in the Foot and Ankle After Extracorporeal Membrane Oxygenation: A Case Report.

Osteonecrosis is acknowledged as a relatively uncommon disorder caused by various factors, including autoimmune diseases, drug-induced diseases, inherited metabolic disorders, coagulation disorders, and underlying malignancies. To our knowledge, no previous research has investigated osteonecrosis stemming from extracorporeal membrane oxygenation. Herein, we report a rare case of postperipheral venoarterial extracorporeal membrane oxygenation-induced multifocal osteonecrosis in the foot and ankle that demonstrated a low serpiginous peripheral signal on T1-weighted images and a double-line sign on fat-suppressed or T2-weighted magnetic resonance images. Conservative treatment was applied, and the patient was mostly recuperated after 6 months.

Comparative Osteogenesis and Degradation Behavior of Magnesium Implant in Epiphysis and Diaphysis of the Long Bone in the Rat Model.

Magnesium (Mg), as a biodegradable material, is a promising candidate for orthopedic surgery. Long-bone fractures usually occur in cancellous-bone-rich epiphysis at each end or the cortical-rich diaphysis in the center, with different bone healing processes. Little is known about the differences in results between the two regions when applying Mg implants. Therefore, this study aimed to compare the biodegradation and osteogenesis of Mg implants in a rat model's epiphysis and diaphysis of the long bone. Twelve male Sprague Dawley rats underwent Mg rod implantation in the distal femoral epiphyses and tibial diaphyses. Every three weeks for up to twelve weeks, degradation behavior, gas evolution, and new bone formation were measured by micro CT. Histomorphology was analyzed by Hematoxylin and Eosin, Villanueva bone staining, and TRAP staining for osteoclastogenesis evaluations. Micro-CT analysis showed statistically significant higher new bone formation in the epiphysis group than in the diaphysis group, which correlated with a lower gas volume. Histological analysis showed higher osseointegration of Mg implants in the epiphyseal region than in the diaphyseal region. The magnesium implant's osteoclastogenesis-inhibiting properties were shown in the surrounding areas in both the cortical bone of the diaphysis and the cancellous bone of the epiphysis. Our findings show the differences in the magnesium implant's osteogenesis and biodegradation in the epiphysis and the diaphysis. These dissimilarities indicate a better response of the epiphyseal region to the Mg implants, a promising biomaterial for orthopedic surgery applications.

Novel oxysterols have pro-osteogenic and anti-adipogenic effects in vitro and induce spinal fusion in vivo.

Stimulation of bone formation by osteoinductive materials is of great clinical importance in spinal fusion surgery, repair of bone fractures, and in the treatment of osteoporosis. We previously reported that specific naturally occurring oxysterols including 20(S)-hydroxycholesterol (20S) induce the osteogenic differentiation of pluripotent mesenchymal cells, while inhibiting their adipogenic differentiation. Here we report the characterization of two structural analogues of 20S, Oxy34 and Oxy49, which induce the osteogenic and inhibit the adipogenic differentiation of bone marrow stromal cells (MSC) through activation of Hedgehog (Hh) signaling. Treatment of M2-10B4 MSC with Oxy34 or Oxy49 induced the expression of osteogenic differentiation markers Runx2, Osterix (Osx), alkaline phosphatase (ALP), bone sialoprotein (BSP), and osteocalcin (OCN), as well as ALP enzymatic activity and robust mineralization. Treatment with oxysterols together with PPARγ activator, troglitazone (Tro), inhibited mRNA expression for adipogenic genes PPARγ, LPL, and aP2, and inhibited the formation of adipocytes. Efficacy of Oxy34 and Oxy49 in stimulating bone formation in vivo was assessed using the posterolateral intertransverse process rat spinal fusion model. Rats receiving collagen implants with Oxy 34 or Oxy49 showed comparable osteogenic efficacy to BMP2/collagen implants as measured by radiography, MicroCT, and manual inspection. Histological analysis showed trabecular and cortical bone formation by oxysterols and rhBMP2 within the fusion mass, with robust adipogenesis in BMP2-induced bone and significantly less adipocytes in oxysterol-induced bone. These data suggest that Oxy34 and Oxy49 are effective novel osteoinductive molecules and may be suitable candidates for further development and use in orthopedic indications requiring local bone formation.