Autophagy in an extruded disc compared to the remaining disc after lumbar disc herniation in the same patient.

PURPOSE: The purpose of this study was to investigate autophagy in an extruded disc and to compare this activity with the activity in the remaining disc after lumbar disc herniation in the same patient. METHODS: In total, 12 patients (females 4, males 8) with the extruded type of lumbar disc herniation (LDH) were surgically treated. Their mean age was 54.3 ± 15.8 years (range: 29 ~ 78 years). The mean interval from the occurrence of symptoms to the operation was 9.8 ± 9.4 weeks (range: 2 ~ 24 weeks). The extruded discs were excised, and the remaining disc material removed, to prevent recurrence of herniation. Immediately after specimen collection, all tissues were stored at -70 °C prior to analysis. Autophagy was assessed immunohistochemically and via Western blotting for Atg5, Atg7, Atg12, Atg12L1, and Beclin-1. And the relationship between autophagy and apoptosis was investigated by correlation analysis of caspase-3 with autophagy proteins. RESULTS: The expression levels of autophagic markers were significantly increased in the extruded discs compared to the remaining discs within the same patients. The mean expression levels of Atg5, Atg7, Atg12, and Beclin-1 in extruded discs were statistically significantly higher than those in the remaining discs (P < 0.01, P < 0.001, P < 0.01, and P < 0.001 respectively). CONCLUSIONS: The autophagic pathway was more active in extruded disc material than in remaining disc material within the same patient. This may explain spontaneous resorption of the extruded disc after LDH.

Comparative Analysis of Autophagy and Apoptosis in Disc Degeneration: Understanding the Dynamics of Temporary-Compression-Induced Early Autophagy and Sustained-Compression-Triggered Apoptosis.

The purpose of this study was to investigate the initiation of autophagy activation and apoptosis in nucleus pulposus cells under temporary compression (TC) and sustained compression (SC) to identify ideal research approaches in intervertebral disc degeneration. Various techniques were used: radiography (X-ray), magnetic resonance imaging (MRI), transmission electron microscope (TEM), H&E staining, Masson's trichrome staining, immunohistochemistry (IHC) (LC3, beclin-1, and cleaved caspase-3), and real-time polymerase chain reaction (RT-qPCR) for autophagy-related (beclin-1, LC3, and P62) and apoptosis-related (caspase-3 and PARP) gene expression analysis. X-ray and MRI revealed varying degrees of disc degeneration, ranging from moderate to severe in both groups. The severity was directly linked to compression duration, with SC resulting in notably severe central NP cell degeneration. Surprisingly, TC also caused similar, though less severe, degeneration. Elevated expression of LC3 and beclin-1 was identified after 6 weeks, but it notably declined after 12 weeks. Central NP cells in both groups exhibited increased expression of cleaved caspase-3 that was positively correlated with the duration of SC. TC showed fewer apoptotic markers compared to SC. LC3, beclin-1, and P62 mRNA expression peaked after 6 weeks and declined after 12 weeks in both groups. Cleaved caspase-3 and PARP expression peaked in SC, positively correlating with longer compression duration, while TC showed lower levels of apoptosis gene expression. Furthermore, TEM results revealed different events of the autophagic degradation process after 2 weeks of compression. TCmay be ideal for studying early triggered autophagy-mediated degeneration, while SC may be ideal for studying late or slower-triggered apoptosis-mediated degeneration.

Role of Necroptosis in Intervertebral Disc Degeneration.

Apoptosis has historically been considered the primary form of programmed cell death (PCD) and is responsible for regulating cellular processes during development, homeostasis, and disease. Conversely, necrosis was considered uncontrolled and unregulated. However, recent evidence has unveiled the significance of necroptosis, a regulated form of necrosis, as an important mechanism of PCD alongside apoptosis. The activation of necroptosis leads to cellular membrane disruption, inflammation, and vascularization. This process is crucial in various pathological conditions, including intervertebral disc degeneration (IVDD), neurodegeneration, inflammatory diseases, multiple cancers, and kidney injury. In recent years, extensive research efforts have shed light on the molecular regulation of the necroptotic pathway. Various stimuli trigger necroptosis, and its regulation involves the activation of specific proteins such as receptor-interacting protein kinase 1 (RIPK1), RIPK3, and the mixed lineage kinase domain-like (MLKL) pseudokinase. Understanding the intricate mechanisms governing necroptosis holds great promise for developing novel therapeutic interventions targeting necroptosis-associated IVDD. The objective of this review is to contribute to the growing body of scientific knowledge in this area by providing a comprehensive overview of necroptosis and its association with IVDD. Ultimately, these understandings will allow the development of innovative drugs that can modulate the necroptotic pathway, offering new therapeutic avenues for individuals suffering from necroptosis.

Osteoclast and Sclerostin Expression in Osteocytes in the Femoral Head with Risedronate Therapy in Patients with Hip Fractures: A Retrospective Comparative Study.

Background and Objectives: The majority of research on the effects of osteoporosis drugs has measured the bone mineral density (BMD) of the spine and femur through dual-energy X-ray absorptiometry (DEXA) and compared and analyzed the effects of the drugs through changes in the BMD values. This study aims to compare osteoclast and sclerostin expression in osteocytes after risedronate therapy by obtaining femoral heads from patients with hip fractures. Materials and Methods: We obtained the femoral heads of 10 female patients (age: ≥65 years) who received risedronate therapy for at least 1 year through hip arthroplasty during 2019−2021 (risedronate group). Meanwhile, 10 patients who had never received osteoporosis treatment were selected as controls using propensity scores with age, body mass index, and bone density as covariates (control group). While the osteoclast count was evaluated using tartrate-resistant acid phosphatase (TRAP) staining, the sclerostin expression in osteocytes was assessed using immunohistochemistry. Moreover, Western blotting and polymerase chain reaction (PCR) were performed for receptor activation of nuclear factor kappa-Β ligand (RANKL), RANK, osteoprotegerin (OPG), sclerostin, and bone morphogenetic protein-2 (BMP2). Results: TRAP staining revealed significantly more TRAP-positive cells in the control group (131.75 ± 27.16/mm2) than in the risedronate group (28.00 ± 8.12/mm2). Moreover, sclerostin-positive osteocytes were expressed more in the control group (364.12 ± 28.12/mm2) than in the risedronate group (106.93 ± 12.85/mm2). Western blotting revealed that the expressions of RANKL, RANK, sclerostin, and BMP2 were higher in the control group than in the risedronate group (p < 0.05). Furthermore, RANK, sclerostin, and OPG protein levels were higher in the control group than in the risedronate group. Conclusions: In this study, the risedronate group demonstrated lower osteoclast activity and sclerostin expression in osteocytes in the femoral head than the control group.

Analysis of pain markers and epidural fibrosis caused by repeated spinal surgery in Sprague-Dawley rats.

BACKGROUND: Epidural fibrosis is one of the aetiologies of pain following a spinal revision surgery. It is reported that the specific members of the mitogen - activated protein kinases (MAPK) family might mediate neuropathic pain. However, roles of epidural fibrosis caused by repeated spinal surgeries and pain-related proteins in causing the post spinal surgery syndrome remain unknown. Using a rat spinal surgery epidural fibrosis and adhesion model, in this study, we evaluated and investigated the relationship between pain markers and epidural fibrosis. METHODS: Sprague-Dawley rats that underwent the spinal surgery were divided into three groups: group A (single laminectomy), group B (two repeated surgeries) and group C (three repeated surgeries). Dural thickness was measured in each experimental group, and immunohistochemical analysis and western blotting of mitogen-activated protein kinases were performed (ERK, p38 and JNK) using the spine cord. RESULTS: Dural thickness was 6.363 ± 1.911 µm in group A, 13.238 ± 2.123 µm in group B and 19.4 ± 2.115 µm in group C, respectively. In the western blotting, phosphorylated ERK expression gradually increased with the number of repeated surgeries, and expression in groups B (1.77-fold) and C (2.42-fold) increased as compared to expression in group A. Phosphorylated p38 showed an increasing trend with the number of repeated surgeries, and groups B (1.17-fold) and C (1.33-fold) expression increased compared with group A. However, phosphorylated JNK expression did not gradually increase with the number of repeated surgeries, and groups B (1.62-fold) and C (1.43-fold) expression increased compared with group A. Excluding phosphorylated JNK, immunohistochemical analysis revealed that phosphorylated ERK and p38 expression gradually increased with the number of repeated surgeries in the spine dorsal horn, as evidenced by western blotting. CONCLUSIONS: Repeated spinal surgeries may increase dural thickness and expression of phosphorylated ERK and p38 in the spinal dorsal horn, and it suggests that the neuropathic pain is likely induced by epidural fibrosis and that the pain increases with the number of repeated surgeries.

Posterior locked lateral compression injury of the pelvis in geriatric patients: an infrequent and specific variant of the fragility fracture of pelvis.

INTRODUCTION: Posterior locked lateral compression injury (PLLCI) of the pelvic ring is an infrequent variant of lateral compression injury, a condition described in only eight reported cases since 2000. Lateral compression injury usually results from high-energy trauma and is characterized by locking between the medially translated fractured ilium and the anterior border of the sacrum, regardless of whether the fractured ilium involves the sacroiliac joint. However, in our experience, lateral compression injury can also result from low-energy trauma as a manifestation of pelvic fragility fracture. The aim of the present study was to describe this rare form of PLLCI in a case series of geriatric patients. METHODOLOGY: A retrospective analysis of consecutive patients with pelvic ring injuries who were admitted to our hospital from January 2008 to April 2015 identified seven geriatric patients (1 male and 6 females; median age 81 years) with a form of PLLCI. RESULTS: All injuries were due to falls from a standing position onto the ground. All seven cases demonstrated characteristics of a locking fractured ilium over the anterior border of the sacrum on axial computed tomography images, but were not detected on plain radiographs. All underwent follow-up at 1 year or later with improved mean visual analogue scale scores (range 0-3). Regarding Koval walking ability scores, patients who underwent pelvic brim plating with anterior external fixation were more likely to regain their pre-injury walking ability than patients who only underwent anterior external fixation or conservative treatment. CONCLUSION: Geriatric patients can experience PLCCIs of the pelvis due to low-energy trauma. These fractures have different characteristics from those associated with severe injuries due to high-energy trauma, and they comprise an infrequent form of Rommens fragility fracture of the pelvis (type IIIa). In these cases, appropriate surgical management that includes sacroiliac plating combined with anterior external fixation can yield good outcomes.

Clinical and radiologic outcomes of arthroscopic suture bridge repair for the greater tuberosity fractures of the proximal humerus.

PURPOSE: To report the clinical and radiological outcomes of arthroscopic suture bridge repair for the GT fractures of the shoulder joint. METHODS: From March 2008 to July 2013, we performed arthroscopic suture bridge repair of the GT fractures displaced more than 5 mm superiorly or posteriorly, but less than 2 cm in 40 cases [20 men, 20 women; mean age, 56 (27-80) years] with the average 32 (24-48) months follow-up. At the final follow-up, clinical (ASES, UCLA, SST, KSS score and range of motions) and radiological outcomes using post-operative MRI or CT scan were evaluated. Associated injuries occurred in 21 cases (52.5%): 8 rotator cuff tears; 7 SLAP lesions; 3 glenoid rim fractures; 3 Bankart lesions; 5 biceps tendon tears; 1 partial subscapularis tear; 1 combined subscapularis and biceps tendon tear, and 1 brachial plexus injury. RESULTS: At the final follow-up, the mean VAS score improved from 7 to 1; ASES, to 92; UCLA, to 32; KSS, to 90; and SST, to 10. Mean forward flexion, abduction, external rotation at the side, and internal rotation at the back were improved to 157°, 157°, 37° and T11, respectively. Mean residual superior and posterior displacement of the fracture was 0 (range -5 to 3.3) mm and 0.1 (-5.5 to 3.2) mm, respectively, compared to pre-operative displacement of 4.9 (0-14) mm and 4.5 (0-20) mm, respectively (p < 0.001). Complications included anchor protrusion in five cases. CONCLUSION: Arthroscopic suture bridge repair was useful for the treatment of displaced GT fractures with or without comminution and the management of the combined lesions. At the final follow-up, meaningful remodeling of the GT fracture and satisfactory clinical outcomes could be achieved.

A study of sacral anthropometry to determine S1 screw placement for spinal lumbosacral fixation in the Korean population.

PURPOSE: 1. To investigate the incidence of closed-type PSIS in the Korean population. 2. To categorize the morphological features of Korean sacrum. 3. To measure the safe marginal length and angle for screw fixation considering the PSIS and course of the external iliac vein, using a Korean sacrum model. METHODS: We performed our study in 160 sacra including the pelvic ring obtained from 80 Korean cadavers. The bony measurements were obtained by performing 1-mm computed tomography cuts from the L5 lumbar vertebra to the pelvic ring and excluding other structures. We evaluated the incidence of anatomic variation of the PSIS and measured the safe marginal length and angle for screw fixation considering the PSIS and course of the external iliac vein, using a Korean sacrum model. RESULTS: Our study showed that the closed type of PSIS is more frequent in males than in females. The optimal angle for screw fixation is 16.91 ± 6.85 (°), while the left side S1 pedicle insertion angle is 16.00 ± 6.20 (°). The average Korean optimal screw length is 58.35 ± 14.90 (cm) for the right side and 55.89 ± 16.16 (cm) for the left side. CONCLUSION: With reference to these parameters, the optimal screw length and angle can be chosen and bicortical anteromedial screw fixation can be easily and safely performed.

Outcome After Arthroscopic Decompression of Inferior Labral Cysts Combined With Labral Repair.

PURPOSE: To analyze the clinical and radiologic outcomes of arthroscopic cyst decompression and labral repair in patients with inferior paralabral cysts with chronic shoulder pain. METHODS: Between March 2006 and September 2012, 16 patients who were identified as having inferior paralabral cysts presented with chronic shoulder pain. All patients underwent a thorough physical examination and preoperative magnetic resonance arthrographic evaluation. The mean age was 30 years (range, 17 to 50 years). The mean follow-up period was 38 months (range, 16 to 60 months). Clinical outcome scores (American Shoulder and Elbow Surgeons; University of California, Los Angeles; and Simple Shoulder Test) and passive shoulder range of motion were evaluated at last follow-up. Follow-up magnetic resonance imaging was performed at a mean of 8 months to determine the labral healing status and assess for cyst recurrence. RESULTS: The incidence of isolated inferior paralabral cysts was 0.6% (16 of 2,656 cases). Of the patients, 8 had multiple cysts and 8 had a single cyst. The mean length and width of the cysts were 1.0 cm and 0.4 cm, respectively. Eight cases had a history of trauma, and 13 patients were involved in sports activities. Seventy-five percent of cases showed a positive relocation test. The mean American Shoulder and Elbow Surgeons; University of California, Los Angeles; and Simple Shoulder Test scores improved from 64, 22, and 8.7, respectively, preoperatively to 83, 31, and 10, respectively (P < .001), at final follow-up. Shoulder range of motion did not show any significant improvement. The location of the labral tear was as follows: anteroinferior tear in 5 cases, posteroinferior tear in 8 cases, and combined anteroinferior and posteroinferior tear in 3 cases. All cysts were found to be in association with a labral tear. A mean of 2.7 anchors were used for inferior labral repair. These cysts were found only in male patients. None of the patients showed any evidence of cyst recurrence on follow-up magnetic resonance imaging. CONCLUSIONS: Inferior labral tears treated with cyst decompression and labral repair showed satisfactory clinical results without any recurrence. Inferior paralabral cysts should be considered in the differential diagnosis in patients presenting with chronic shoulder pain, particularly active male patients. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Steroid treatment can inhibit nuclear localization of members of the NF-κB pathway in human disc cells stimulated with TNF-α.

Steroid applications are able to repress inflammatory activity in various conditions, including herniation of the nucleus pulposus (HNP), by inhibiting tumour necrosis factor (TNF)-α, but the effects of long-term use are unknown. Here, we investigated the effect of dexamethasone (DEXA) on TNF-α-stimulated intervertebral disc cells by monitoring the expression and localization of NF-κB in the cytoplasm and nucleus. Cultured human intervertebral disc cells were left untreated or treated with only TNF-α, only DEXA, or with TNF-α and DEXA simultaneously. Cytoplasmic and nuclear proteins were extracted and Western blotted after 10 min, 1 or 2 h, to evaluate the expression of p50, p65, p52, and p100 (components of NF-κB). Immunofluorescence analysis was used to determine the subcellular localization of the proteins at 1 h. DEXA had limited effects on NF-κB expression in TNF-α-stimulated disc cells within the first 10 min. At 1 h, DEXA prevented the TNF-α-stimulated translocation of p50, p52, and p65. After 2 h, DEXA reduced the nuclear expression of p50, p65, and p52. Thus, DEXA resulted in delayed expression of NF-κB components and inhibited the translocation of p50, p52, and p65 to the nucleus, which would prevent expression of the corresponding genes. Therefore, following stimulation with TNF-α, transcriptional regulation of NF-κB in disc cells is mainly mediated via the classical pathway, but also to some extent via the alternative pathway. Hence, blockade of sub-acute inflammatory changes in HNP can be achieved by early injection of steroids, whereas long-term injection of a steroid may initiate NF-κB autophosphorylation.

Experimental Verification of the Impact of the Contact Area between the Defect Site and the Scaffold on Bone Regeneration Efficacy.

In the field of bone tissue engineering, which is being developed for the ideal restoration of bone defects, researchers are exploring the improvement of the bone regeneration efficacy of scaffolds through various approaches involving osteoconductive, osteoinductive, and angiogenic factors. In the current trend of research, there is also a suggestion that the topological factors of recent scaffolds may influence the attachment, migration, proliferation, and differentiation of bone cells. Building upon experimental confirmation of the effect of scaffold conformity with the defect site on enhanced bone regeneration in previous studies, we conducted this research to experimentally investigate the relationship between contact area with the defect site and bone regeneration efficacy. The results demonstrated that as the contact area of the scaffold increased, not only did the resistance to bone tissue growth increase, more significant bone regeneration also occurred, as evidenced through histological analysis and micro-CT analysis. This research confirms that the contact area between the scaffold and the defect site is a critical variable affecting bone regeneration efficacy, emphasizing its importance when designing customized scaffolds. This finding holds promising implications for future studies and applications in the field.

The Role of Bioceramics for Bone Regeneration: History, Mechanisms, and Future Perspectives.

Osteoporosis is a skeletal disorder marked by compromised bone integrity, predisposing individuals, particularly older adults and postmenopausal women, to fractures. The advent of bioceramics for bone regeneration has opened up auspicious pathways for addressing osteoporosis. Research indicates that bioceramics can help bones grow back by activating bone morphogenetic protein (BMP), mitogen-activated protein kinase (MAPK), and wingless/integrated (Wnt)/ß-catenin pathways in the body when combined with stem cells, drugs, and other supports. Still, bioceramics have some problems, such as not being flexible enough and prone to breaking, as well as difficulties in growing stem cells and discovering suitable supports for different bone types. While there have been improvements in making bioceramics better for healing bones, it is important to keep looking for new ideas from different areas of medicine to make them even better. By conducting a thorough scrutiny of the pivotal role bioceramics play in facilitating bone regeneration, this review aspires to propel forward the rapidly burgeoning domain of scientific exploration. In the end, this appreciation will contribute to the development of novel bioceramics that enhance bone regrowth and offer patients with bone disorders alternative treatments.

Rapid in vitro corrosion induced by crack-like pathway in biodegradable Mg-10% Ca alloy.

The in vitro corrosion mechanism of the biodegradable cast Mg-10% Ca binary alloy in Hanks' solution was evaluated through transmission electron microscopy observations. The corrosion behavior depends strongly on the microstructural peculiarity of Mg2Ca phase surrounding the island-like primary Mg phase and the fast corrosion induced by the interdiffusion of O and Ca via the Mg2Ca phase of lamellar structure. At the corrosion front, we found that a nanosized crack-like pathway was formed along the interface between the Mg2Ca phase and the primary Mg phase. Through the crack-like pathway, O and Ca are atomically exchanged each other and then the corroded Mg2Ca phase was transformed to Mg oxides. The in vitro corrosion by the exchange of Ca and O at the nanosized pathway led to the rapid bulk corrosion in the Mg-Ca alloys.

Double triggering of extensor digiti minimi: a case report.

Extensor tendon triggering is a rare disease entity. Even less common is a case of extensor digiti minimi (EDM) double triggering caused by impingement on the extensor retinaculum. Herein, we describe one patient with EDM double triggering developed at the extensor retinaculum and over the metacarpal head caused by its impingement on the extensor retinaculum.

Post-traumatic pseudoaneurysm of the medial plantar artery combined with tarsal tunnel syndrome: two case reports.

Pseudoaneurysms in the foot are more often reported in the lateral plantar artery than the medial plantar artery, most likely because of its more superficial location. There are no reports of pseudoaneurysm of the medial plantar artery after trauma. We present two cases of pseudoaneurysm of the medial plantar artery after blunt foot trauma and foot laceration. This pseudoaneurysm compressed a posterior tibial nerve, resulting in tarsal tunnel syndrome. The patients were treated successfully using transcatheter embolization without the need for surgical intervention. The tarsal tunnel syndrome also subsided. Here, the authors report these cases and provide a review of literature.

Fracture Liaison Service in Korea: 2022 Position Statement of the Korean Society for Bone and Mineral Research.

Osteoporosis and osteoporotic fractures cause socioeconomic concerns, and medical system and policies appear insufficient to prepare for these issues in Korea, where the older adult population is rapidly increasing. Many countries around the world are already responding to osteoporosis and osteoporotic fractures by adopting fracture liaison service (FLS), and such an attempt has only begun in Korea. In this article, we introduce the operation methods for institutions implementing FLS and characteristics of services, and activities of the FLS Committee for FLS implementation in the Korean Society for Bone and Mineral Research. In addition, we hope that the current position statement will contribute to the implementation of FLS in Korea and impel policy changes to enable a multidisciplinary and integrated FLS operated under the medical system.

Postoperative changes of early-phase inflammatory indices after uncomplicated anterior cervical discectomy and fusion using allograft and demineralised bone matrix.

PURPOSES: We investigated sequential levels of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) in uncomplicated ACDF (anterior cervical discectomy and fusion) using allograft and DBM (demineralised bone matrix) for primary cervical spondylosis and/or disc herniation. To our knowledge, there has been no study to investigate the diagnostic value of CRP and ESR for postoperative infection in ACDF using allograft and DBM. METHODS: Blood samples of 85 patients, who underwent one- (n = 51) or two-level (n = 34) ACDF, were obtained and evaluated before surgery and on the first, third, fifth, seventh, 14th, 30th, and 90th postoperative days. No infection was found in any patient for at least one year follow-up period. RESULTS: Mean CRP value increased significantly on the first postoperative day and reached a peak on the third postoperative day. The peak level rapidly decreased but remained elevated on the fifth, seventh, and 14th postoperative days. Mean ESR value increased significantly and reached a peak on the third postoperative day. The peak level gradually decreased but remained elevated on the fifth and seventh postoperative days. One- and two-level ACDF exhibited similar postoperative changes in CRP and ESR values and no significant difference in mean levels of CRP and ESR throughout the follow-up periods. CONCLUSIONS: This study demonstrates that uncomplicated ACDF using allograft and DBM showed significant abnormal values of CRP and ESR during the early postoperative period. This result suggests that abnormal values of CRP and ESR in the early postoperative period do not indicate acute postoperative infection after ACDF using allograft and DBM. Straying from the normal course, such as a second rise or a failure to decrease, of CRP and ESR is more important to signpost acute postoperative infection in ACDF using allograft and DBM.

Lumbar Interbody Fusion and Osteobiologics for Lumbar Fusion.

Lumbar interbody fusion (LIF) is an excellent treatment option for a number of lumbar diseases. LIF can be performed through posterior, transforaminal, anterior, and lateral or oblique approaches. Each technique has its own pearls and pitfalls. Through LIF, segmental stabilization, neural decompression, and deformity correction can be achieved. Minimally invasive surgery has recently gained popularity and each LIF procedure can be performed using minimally invasive techniques to reduce surgery-related complications and improve early postoperative recovery. Despite advances in surgical technology, surgery-related complications after LIF, such as pseudoarthrosis, have not yet been overcome. Although autogenous iliac crest bone graft is the gold standard for spinal fusion, other bone substitutes are available to enhance fusion rate and reduce complications associated with bone harvest. This article reviews the surgical procedures and characteristics of each LIF and the osteobiologics utilized in LIF based on the available evidence.

Surgical management of pilon fractures with large segmental bone defects using fibular strut allografts: a report of two cases.

We present two patients with open pilon fractures with large bone defects treated successfully with fibular strut allografts. The patients were initially treated by massive irrigation, wound debridement, and temporary external fixation. After complete wound healing, the bone defects were managed. Because autologous iliac crest or fibular bone grafts were impossible to be harvested due to multiple fractures, the bone defects were reconstructed with fibular strut allografts. Fixation was performed with a periarticular distal tibia locking plate. At 2 months postoperatively, the patients ambulated with partial weight-bearing; at 6 months, they had full range of motion of the ankle joint and full weight-bearing.

Total Meniscus Reconstruction Using a Polymeric Hybrid-Scaffold: Combined with 3D-Printed Biomimetic Framework and Micro-Particle.

The meniscus has poor intrinsic regenerative capability, and its injury inevitably leads to articular cartilage degeneration. Although there are commercialized off-the-shelf alternatives to achieve total meniscus regeneration, each has its own shortcomings such as individualized size matching issues and inappropriate mechanical properties. We manufactured a polycaprolactone-based patient-specific designed framework via a Computed Tomography scan images and 3D-printing technique. Then, we completed the hybrid-scaffold by combining the 3D-printed framework and mixture micro-size composite which consists of polycaprolactone and sodium chloride to create a cell-friendly microenvironment. Based on this hybrid-scaffold with an autograft cell source (fibrochondrocyte), we assessed mechanical and histological results using the rabbit total meniscectomy model. At postoperative 12-week, hybrid-scaffold achieved neo-meniscus tissue formation, and its shape was maintained without rupture or break away from the knee joint. Histological and immunohistochemical analysis results showed obvious ingrowth of the fibroblast-like cells and chondrocyte cells as well as mature lacunae that were embedded in the extracellular matrix. Hybrid-scaffolding resulted in superior shape matching as compared to original meniscus tissue. Histological analysis showed evidence of extensive neo-meniscus cell ingrowth. Additionally, the hybrid-scaffold did not induce osteoarthritis on the femoral condyle surface. The 3D-printed hybrid-scaffold may provide a promising approach that can be applied to those who received total meniscal resection, using patient-specific design and autogenous cell source.