Bone Fusion Research Articles

Comparison of Fusion Rates among Various Demineralized Bone Matrices in Posterior Lumbar Interbody Fusion.

Background and Objectives: Posterior lumbar interbody fusion (PLIF) plays a crucial role in addressing various spinal disorders. The success of PLIF is contingent upon achieving bone fusion, as failure can lead to adverse clinical outcomes. Demineralized bone matrix (DBM) has emerged as a promising solution for promoting fusion due to its unique combination of osteoinductive and osteoconductive properties. This study aims to compare the effectiveness of three distinct DBMs (Exfuse®, Bongener®, and Bonfuse®) in achieving fusion rates in PLIF surgery. Materials and Methods: A retrospective review was conducted on 236 consecutive patients undergoing PLIF between September 2016 and February 2019. Patients over 50 years old with degenerative lumbar disease, receiving DBM, and following up for more than 12 months after surgery were included. Fusion was evaluated using the Bridwell grading system. Bridwell grades 1 and 2 were defined as 'fusion', while grades 3 and 4 were considered 'non-fusion.' Clinical outcomes were assessed using visual analog scale (VAS) scores for pain, the Oswestry disability index (ODI), and the European quality of life-5 (EQ-5D). Results: Fusion rates were 88.3% for Exfuse, 94.3% for Bongener, and 87.7% for Bonfuse, with no significant differences. All groups exhibited significant improvement in clinical outcomes at 12 months after surgery, but no significant differences were observed among the three groups. Conclusions: There were no significant differences in fusion rates and clinical outcomes among Exfuse, Bongener, and Bonfuse in PLIF surgery.

Arthroscopic Subtalar Distraction Arthrodesis in Post-Traumatic Indications

This manuscript aims to present the method of arthroscopic assisted subtalar arthrodesis and to evaluate the benefi ts of this surgery on our study population. In the period from 9/2007 to 1/2020, a total of 33 subtalar arthrodesis were performed in 31 patients aged 19-66 years (mean 48 years, median 50 years). The indication for arthrodesis was subtalar arthritis causing pain and gait disorders, or hindfoot deformities (most commonly after a calcaneus bone fracture). The arthroscopic assisted subtalar arthrodesis was performed with autologous tricortical bone block graft harvesting from the pelvis, supplemented by autologous cancellous bone graft. Stabilization was achieved by cannulated screws inserted in neutral ankle position. Patients in our retrospective study were followed up for a mean of 48 months (range, 24-130 months). The patients were evaluated preoperatively and at 2 years after surgery. The hindfoot angles and height (TCA - talocalcaneal angle, CIA - calcaneal inclination angle, TCH - talocalcaneal height) were evaluated on radiographs, bone union was assessed on radiographs and CT scans. The clinical assessment was performed using the ankle-hindfoot scale (AHS) of AOFAS (AOFAS score). The preoperative AOFAS score was 35-68 points (mean 52, median 54), the postoperative AOFAS score at 2 years after arthrodesis was 58-94 points (mean 82, median 82). Both the mean and median values of AOFAS score showed a signifi - cant progress from the poor result to the good and excellent result. After 2 years the TCA value decreased in 18 patients (56%) by no more than 3°. The CIA decrease observed in 21 patients (64%) was by 1° on average. The TCH decrease of 1-5 mm after 2 years since the surgery was seen in 16 patients. In 2 patients incomplete healing of arthrodesis was observed, manifested as a clinically asymptomatic non-union. No deep infection was reported. In agreement with the current literature, the arthroscopic subtalar arthrodesis has been confi rmed to be a safe method for the management of consequences of hindfoot fractures, with minimum complications and leading to accelerated bone fusion. Differences can be found in the approach, position, use of cancellous bone graft and surgical techniques. In recent years, prone position, posterior approaches, use of cancellous bone graft, distraction and fi xation with 2-3 screws divergently inserted into the bone prevail. The degree of healing of the bone fusion is generally an important factor. In our study population, non-healing was recorded in 2 patients, namely in the form of a clinically silent non-union. Neurological or early complications and/or osteosynthesis material failure occurred in up to a maximum of 10% of cases. The conclusive results of minimally invasive arthrodesis based on the AOFAS score have been confi rmed by us as well as by most authors. Our study confi rmed that the arthroscopic assisted subtalar arthrodesis is a successful, reliable and safe minimally invasive method, with minimum complications, leading to stable arthrodesis. subtalar arthrodesis, subtalar arthroscopy.

Dosing Strategy for Osteobiologics Used in ACDF Surgery: Influence on Fusion Rates and Associated Complications. A Systematic Literature Review.

Systematic review. To assess the available evidence related to dose-dependent effectiveness (i.e., bone fusion) and morbidity of osteobiologics used in anterior cervical discectomy and fusion (ACDF). Studies with more than 9 adult patients with degenerated/herniated cervical discs operated for one-to four-levels ACDF reporting used osteobiologics doses, fusion rates at six months or later, and related comorbidities were included. PubMed, EMBASE, ClinicalTrials, and Cochrane were searched through September 2021. Data extracted in spread sheet and risk of bias assessed using MINORS and Rob-2. Sixteen studies were selected and sub-grouped into BMP and non-BMP osteobiologics. For the 10 BMP studies, doses varied from 0.26 to 2.1mg in 649 patients with fusion rates of 95.3 to 100% at 12months. For other osteobiologics, each of six studies reported one type of osteobiologic in certain dose/concentration/volume in a total of 580 patients with fusion rates of 6.8 to 96.9% at 12months. Risk of bias was low in three of the 13 non-randomized (18.75%) and in all the three randomized studies (100%). Taking into account the inconsistent reporting within available literature, for BMP usage in ACDF, doses lower than 0.7mg per level can achieve equal successful fusion rates as higher doses, and there is no complication-free dose proved yet. It seems that the lower the dose the lower the incidence of serious complications. As for non-BMP osteobiologics the studies are very limited for each osteobiologic and thus conclusions must be drawn individually and with caution.

Sternal cleft: new options for reconstruction.

Sternal cleft (SC) is a rare congenital affection caused by the absence of sternal bar union. Diagnosis is generally made after birth due to paradoxical midline movement, although it can be made prenatally by ultrasonography. A computerized tomography scan (CT scan) after birth is generally used to confirm the diagnosis, assess other intrathoracic conditions, classify the SC, and plan for surgery. SC can be classified as complete or incomplete. A complete SC has a full gap between sternal bars. An incomplete SC is subdivided into superior or inferior, related to the point of bone fusion between the sternal bars. The goal of surgical treatment is to protect mediastinal structures. Many authors advocate the repair in newborn patients, although it can be performed in older patients. The main argument in its favor is the chest's flexibility, with a reduced risk of compression of the mediastinal structures. There are several cases of series and distinct surgical techniques in the literature. Some authors have suggested the use of autologous tissue, prosthetic material such as mesh, or titanium plates and screws. Although difficulties are often encountered in surgical access, they have not been discussed. Therefore, we are promoting modifications to the technique in response to this. The purpose is to show innovations, and how to deal with adversity during the procedure.

Are There Advantages in Cervical Intrafacetal Fusion With Minimal Posterolateral Fusion (PLF) Compared to Conventional PLF in Posterior Cervical Fusion?

We propose that cervical intrafacetal fusion (cIFF) using bone chip insertion into the facetal joint space additional to minimal PLF is a supplementary fusion method to conventional posterolateral fusion (PLF). Patients who underwent posterior cervical fixation accompanied by cIFF with minimal PLF or conventional PLF for cervical myelopathy from 2012 to 2023 were investigated retrospectively. Radiological parameters including Cobb angle and C2-7 sagittal vertical axis (SVA) were compared between the 2 groups. In cIFF with minimal PLF group, cIFF location and PLF location were carefully divided, and the fusion rates of each location were analyzed by computed tomography scan. Among enrolled 46 patients, 31 patients were in cIFF group, 15 in PLF group. The postoperative change of Cobb angle in 1-year follow-up in cIFF with minimal PLF group and conventional PLF group were 0.1° ± 4.0° and -9.7° ± 8.4° respectively which was statistically lower in cIFF with minimal PLF group (p = 0.022). Regarding the fusion rate in cIFF with minimal PLF group in postoperative 6 months, the rates was achieved in 267 facets (98.1%) in cIFF location, and 244 facets (89.7%) in PLF location (p < 0.001). Postoperative sagittal alignment was more preserved in cIFF with minimal PLF group compared with conventional PLF group. Additionally, in cIFF with minimal PLF group, the bone fusion rate of cIFF location was higher than PLF location. Considering the concerns of bone chip migration onto the spinal cord and relatively low fusion rate in PLF method, applying cIFF method using minimized PLF might be a beneficial alternative for posterior cervical decompression and fixation.

Mitigation of BMP-induced inflammation in craniofacial bone regeneration and improvement of bone parameters by dietary hesperidin

Based on anti-inflammatory and osteogenic properties of hesperidin (HE), we hypothesized its systemic administration could be a cost-effective method of improving BMP-induced bone regeneration. Sprague–Dawley rats were allocated into 4 groups (n = 10/group): a 5-mm critical-sized mandible defect + collagen scaffold or, scaffold + 1 µg of BMP2 with and without dietary HE at 100 mg/kg. HE was administered by oral gavage 4 weeks prior to surgeries until euthanasia at day 7 or 14 post-surgery. The healing tissue within the defect collected at day 7 was subjected to gene expression analysis. Mandibles harvested at day 14 were subjected to microcomputed tomography and histology. HE + BMP2-treated rats had a statistically significant decrease in expression of inflammatory genes compared to BMP2 alone. The high-dose BMP2 alone caused cystic-like regeneration with incomplete defect closure. HE + BMP2 showed virtually complete bone fusion. Collagen fibril birefringence pattern (red color) under polarized light indicated high organization in BMP2-induced newly formed bone (NFB) in HE-supplemented group (p < 0.05). Clear changes in osteocyte lacunae as well as a statistically significant increase in osteoclasts were found around NFB in HE-treated rats. A significant increase in trabecular volume and thickness, and trabecular and cortical density was found in femurs of HE-supplemented rats (p < 0.05). Our findings show, for the first time, that dietary HE has a remarkable modulatory role in the function of locally delivered high-dose BMP2 in bone regeneration possibly via control of inflammation, osteogenesis, changes in osteocyte and osteoclast function and collagen maturation in regenerated and native bone. In conclusion, HE had a significant skeletal bone sparing effect and the ability to provide a more effective BMP-induced craniofacial regeneration.

Clinical Observation of Posterior Approach for Surgical Treatment of Thoracolumbar Pseudarthrosis in Ankylosing Spinal Disorders

To evaluate the surgical effectiveness of posterior procedure with long segment stabilization for treating thoracolumbar pseudarthrosis associated with ankylosing spinal disorders (ASD) without anterior fusion or osteotomy. Twelve patients with thoracolumbar pseudarthrosis in ASD were enrolled. All patients underwent posterior long-segment stabilization procedures. In some patients, the percutaneous technique or the aid of a robot or O-arm navigation was utilized for pedicle screw implantation. The clinical results were evaluated by means of the Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI). Radiological outcomes were evaluated for bone fusion, anterior column defect, local kyphotic correction (LK) and position of the pedicle screws. All patients experienced effective bone fusion at the sites of pseudarthrosis. The mean operative time was 161.7±57.1 min, and the average amount of blood loss was 305.8 ± 293.2 ml. For six patients who underwent surgery with the assistance of a robot or O-arm navigation, there was no statistically significant difference observed in terms of operative time and mean blood loss compared to those who used the freehand technique (P>0.05). The VAS score, ODI value, and mean LK angle showed significant improvements at the final follow-up (P<0.05). The accuracy of pedicle screw placement was 96%. Posterior surgery with long-segment fixation, without anterior fusion or osteotomy, can achieve satisfactory outcomes in ASD patients with thoracolumbar pseudarthrosis. The application of percutaneous techniques, as well as the assistance of robots or navigation technique may be a good choice for the treatment of pseudarthrosis in ASD patients.

Accuracy of the GeneXpert® MRSA/SA SSTI test to diagnose methicillin-resistant Staphylococcus spp. infection in bone fixation and fusion and management of infected non-unions

IntroductionThe GeneXpert® MRSA/SA SSTI (Methicillin Resistant Staphylococcus aureus/S. aureus skin and soft tissue infection) PCR test allows early detection of methicillin resistance in staphylococci. This test was developed for skin infections and has been evaluated for prosthetic joint infections but, to our knowledge, has not been evaluated for hardware infections outside of arthroplasties. Furthermore, we conducted a retrospective study in patients with non-prosthetic osteosynthesis hardware aiming: (1) to identify the diagnostic values of the PCR test compared to conventional cultures and the resulting rate of appropriate antibiotic therapy; (2) to identify the rate of false negative (FN) results; (3) to identify and compare the rates of failure of infectious treatment (FN versus others); (4) to search for risk factors for FN of the PCR test. HypothesisThe PCR test allowed early and appropriate targeting of antibiotic therapy. Material and methodsThe results of PCR tests and conventional cultures for osteoarticular infections of non-prosthetic hardware over four years (2012–2016) were compared to identify the diagnostic values of using the results of conventional culture as a reference and the rate of appropriate antibiotic therapies. Infectious management failures between the results of the FN group and the others were compared, and variables associated with a FN of the PCR test were identified. ResultsThe analysis of 419 PCR tests allowed us to establish a sensitivity of 42.86%, a specificity of 96.82%, a positive predictive value of 60% and a negative predictive value of 93.83%. Using the results of the PCR test for the targeting of postoperative antibiotic therapy, it was suitable for staphylococcal coverage in 90.94% (381/419). The rates of patients for whom infectious treatment failed were not significantly different between the FN group and the other patients (20.8% versus 17.7%, respectively; Hazard Ratio=1.12 (95%CI 0.47-2.69, p=0.79)). A skin opening during the initial trauma (p=0.005) and a polymicrobial infection were significantly associated with a risk of FN from the PCR test (p<0.001). ConclusionThe PCR test makes it possible to reduce the duration of empirical broad-spectrum antibiotic therapy during the treatment of an infection of osteosynthesis hardware but causes a lack of antibiotic coverage in 9.06% of cases. Level of evidenceIII; diagnostic case control study.

Early Outcomes of Bone Autografting in the Bilateral Atlantoaxial Joints Applied in Posterior Fusion Surgery.

Cable-dragged reduction and cantilever beam internal fixation can provide promising results in the treatment of atlantoaxial dislocation or instability. However, bilateral atlantoaxial joints bone autografting has not been conducted in this technique. We aim to evaluate the safety and effectiveness of bilateral atlantoaxial joints bone autografting in posterior cable-dragged reduction and cantilever-beam internal fixation. In this retrospective study, we included 14 patients with a minimum 24-month follow-up from December 2019 to September 2020. The granular bone harvested from the iliac crest was packed into the bilateral atlantoaxial joints of 14 patients in posterior cable-dragged reduction and cantilever-beam internal fixation. X-ray imaging and cervical computed tomography (CT) were performed during follow-up. The time required for bone fusion was recorded. The clinical outcomes were evaluated using the JOA scores, NDI, and VAS scores. Mann-Whitney U test, the chi-squared test, or the Fisher exact test were used to compare the two groups regarding patient characteristics, clinical outcomes, bone fusion rates, and cervical sagittal alignment. The operations were successfully performed in all patients without any intraoperative complications. The mean operation time was (169.64 ± 20.91) minutes, and the intraoperative blood loss was (130.71 ± 33.62) mL. All patients received satisfactory reductions and firm bony fusion at the final follow-up. The fusion rates were 64.29% in the atlantoaxial joints and 21.43% in post bone graft area at 3 months postoperatively, and a significant difference was observed (p = 0.022). Besides, the cervical sagittal alignment in all patients was well maintained in the last follow-up compared to preoperatively. Importantly, a complete bony fusion in the atlantoaxial joints was observed in all patients. Moreover, the JOA, NDI, and VAS scores had improved significantly at the last follow-up. Bone autografting of the bilateral atlantoaxial joints is a safe and effective technique to increase bone fusion rates, shorten bone fusion time, and reduce complication rates when the cable-dragged reduction and cantilever beam internal fixation approach is used. Therefore, it is a cost-effective surgical procedure for treating patients with atlantoaxial dislocation or instability.

Conservative treatment of fragility fracture of the pelvis: A retrospective study

BackgroundAlthough an increasing number of studies have reported the usefulness of early minimally invasive surgery (MIS) or fragility fracture of the pelvis (FFP), MIS is difficult to perform in every hospital, partly because of equipment problems. Moreover, different opinions exist on FFP treatment methods and the indication for surgery is usually determined by the fracture type. Since our hospital follows a conservative approach as the basic treatment, this study examined the outcomes of such an FFP approach. HypothesisFFP outcomes are influenced by the fracture type and walking ability before the injury. Patients and methodsWe investigated the bone fusion rate, bone fusion duration, unloading duration, walking ability trends, and outcomes in 76 patients with FFP treated conservatively at our hospital. ResultsThe union rate, mean period until union, and follow-up period were 93.4%, 3.3 months, and 14.3 months, respectively. Walking ability significantly decreased from 5.1 points before the injury to 4.4 points during the last follow-up (p<0.01). The average unloading period was 12.8 days, and FFPs showed a high bone fusion rate, even with conservative treatment. DiscussionMost patients eventually returned to their pre-injury status despite slightly decreased walking ability. Given the invasive nature of surgery, the indications for surgery should be carefully assessed after considering the risk-benefit ratio. Level of evidenceIII; retrospective study.

Comparative study of two retrograde locked intramedullary nail designs for ankle arthrodesis: A finite element analysis.

Ankle arthrodesis is the gold standard for treatment of end-stage arthritis. The goal of ankle arthrodesis is to obtain bony union between the tibia and the talus. Retrograde intramedullary nailing is typically reserved for ankle and subtalar joints arthrodesis. The purpose of this study is to evaluate the effect of two different materials, two locking pin configurations and two nail designs of a retrograde locked intramedullary nail used for ankle arthrodesis. Using the finite element analysis, a numerical study of ankle arthrodesis was developed to evaluate the effect of materials: TI-6Al-4V and stainless steel AISI 316 LVM; two locking pin configurations: five and six pins, on two intramedullary nails: Ø10 × 180 mm and Ø11 × 200 mm. A model of a healthy foot was created from tomographic scans. It was found that the mechanical stimulus required to achieve bone fusion were higher for Ø10 × 180 nails (6.868 ± 0.047) than the Ø11 × 200 nails (5.918 ± 0.047; p < 0.001; mean ± SEM). We also found that six-pin configuration had a higher mechanical stimulus (6.470 ± 0.047) than the five-pin configuration (6.316 ± 0.046; p = 0.020). Similarly, it was higher for titanium (6.802 ± 0.047) than those for stainless steel (5.984 ± 0.046; p < 0.001). Finally, the subtalar zone presented higher values (7.132 ± 0.043) than the tibiotalar zone (5.653 ± 0.050; p < 0.001). The highest mechanical stimulus around the vicinity of tibiotalar and subtalar joint was obtained by Ø10 × 180 nails, made of titanium alloy, with 6P.

Safety and efficacy of autologous bone marrow clot as a multifunctional bioscaffold for instrumental posterior lumbar fusion: a 1-year follow-up pilot study.

Bone marrow aspirate (BMA), when combined with graft substitutes, has long been introduced as a promising alternative to iliac crest bone graft in spinal fusion. However, the use of BMA is limited by the absence of a standardized procedure, a structural texture, and the potential for diffusion away from the implant site. Recently, the potential use of a new formulation of BMA, named BMA clot, has been preclinically described. In this report, we present the results of a prospective pilot clinical study aimed at evaluating the safety and efficacy of autologous vertebral BMA (vBMA) clot as a three-dimensional and multifunctional bioscaffold in instrumented posterior lumbar fusion. Ten consecutive patients with an indication of multilevel (≤5) posterior spinal fusion due to lumbar spine degenerative diseases were included in the study and treated with vBMA. Clinical outcomes were assessed using the Visual Analog Scale (VAS), Oswestry Disability Index (ODI), and EuroQoL-5L (EQ-5L) preoperatively and at 3 months and 12 months after spinal fusion. Bone fusion quality was evaluated at the 12-month follow-up using the Brantigan classification on radiography (XR) imaging. Bone density was measured on computed tomography (CT) scans at 6 and 12 months of follow-up visits at the intervertebral arches and intervertebral joint areas and expressed in Hounsfield unit (HU). The results indicate a successful posterolateral fusion rate of approximately 100% (considering levels with C, D, and E grades according to the Brantigan classification) at the 12-month follow-up, along with an increase in bone density from 6 to 12 months of follow-up. An improvement in the quality of life and health status following surgery, as assessed by clinical scores (ODI, VAS, and EQ-5L), was also observed as early as 3 months postsurgery. No adverse events related to the vBMA clot were reported. This prospective pilot study demonstrates the effectiveness and safety profile of vBMA clot as an advanced bioscaffold capable of achieving posterior lumbar fusion in the treatment of degenerative spine diseases. This lays the groundwork for a larger randomized clinical study.

Does platelet-rich plasma enhance fusion in transforaminal lumbar interbody fusion? A prospective clinico-radiological comparative study

Abstract Background: Several animal studies have shown that platelet-rich plasma (PRP) is effective in enhancing bone fusion. However, the role and efficacy of PRP in spinal fusion surgery remain uncertain. The objective was to evaluate the efficacy of PRP in bone fusion and to compare the clinical and radiological outcomes of transforaminal lumbar interbody fusion (TLIF) with and without PRP. Materials and Methods: This prospective study was done on 50 patients who underwent TLIF surgery for various spinal pathologies. Patients were divided into the control group (underwent TLIF with interbody cage and local bone grafts alone) and the study group (underwent TLIF with interbody cage, local bone grafts, and PRP). Functional outcome was evaluated using visual analog score (VAS) and Oswestry disability index (ODI). Radiological outcome was assessed by Bridwell’s grading system for fusion on computed tomography scan at the end of 2 years. Results: The average bone fusion rate was significantly higher in the PRP group compared to the control group; however, the average duration of fusion was not statistically significant. There was no difference in VAS and ODI at 1 and 2 years. There was also no significant difference in lower back pain, leg pain, and numbness in both groups at the end of 1 year. Conclusion: Although there is no statistically significant difference in functional outcome between both groups, local application of PRP along with autologous bone grafts increases bone fusion rates with good clinical and radiological outcomes.

Posterior Column Reconstruction of the Lumbar Spine Using En Bloc Resected Vertebral Arch in Spinal Tumor and Deformity Surgeries.

In high-grade spinal osteotomy involving large anterior column resection, restoration of the structural integrity of the posterior column at the osteotomy site can reduce postoperative instrumentation failure (IF). This study aimed to describe our technique of posterior strut bone grafting using an en bloc resected vertebral arch, which is useful for posterior column reconstruction after high-grade osteotomies during surgeries for spinal tumor and deformity in the lower lumbar spine. Using a posterior approach, en bloc resection of the targeted vertebral arch was performed in accordance with the surgical technique for total en bloc spondylectomy (TES). The posterior elements in the upper and lower adjacent vertebrae were separated by a significant space after vertebral body resection followed by cage insertion in TES or anterior column osteotomy followed by correction in deformity surgery. To create a new posterior column, the en bloc resected vertebral arch was placed at 90° rotation to bridge the upper and lower vertebral arches. Using this technique, an abundant amount of bone chips made from the resected vertebral elements were placed over the en bloc resected posterior arch as an additional bone graft. The technique was used in three patients who underwent TES for spinal tumors and in one patient who underwent grade 4 osteotomy for adult spinal deformity in the lower lumbar spine. One year after surgery, computed tomography showed that the structural integrity of bony fusion was successfully achieved between the en bloc resected arch and the posterior elements of the adjacent vertebrae in all patients and showed no postoperative IFs. This bone graft technique created new continuity of the posterior column after high-grade osteotomies in the lower lumbar spine. Bone fusion was achieved in the posterior elements to prevent IF after surgery.

A novel porous interbody fusion cage modified by microarc oxidation and hydrothermal treatment technology accelerate osseointegration and spinal fusion in sheep.

The clinical outcome of spinal fusion surgery is closely related to the success of bone fusion. Nowadays, the interbody cage which is used to replace the disc for spinal fusion is expected to have biological activity to improve osseointegration, especially for the aging and osteoporotic patients. Here, through micro-arc oxidation and hydrothermal treatment (MAO + HT), a bioactive CaP coating with micro/nano multilevel morphology was developed on 3D printed Ti6Al4V alloy then verified in vitro and in sheep anterior cervical decompression fusion model systematically. In vitro studies have confirmed the positive effects of characteristic micro/nano morphology and hydrophilicity of the coating formed after surface treatment on the adhesion, proliferation, and osteogenic differentiation of osteoblast precursor cells. Furthermore, the MAO + HT treated interbody cage showed a closer integration with the surrounding bone tissue, improved kinetic stability of the implanted segment, and significantly reduced incidence of fusion failure during the early postoperative period, which indicated that such a surface modification strategy is applicable to the biomechanical and biological microenvironment of the intervertebral space.

Animal Model for Anterior Lumbar Interbody Fusion: A Literature Review.

Lumbar interbody fusion (LIF) is a surgical procedure for treating lumbar spinal stenosis and deformities. It removes a spinal disc and insert a cage or bone graft to promote solid fusion. Extensive research on LIF has been supported by numerous animal studies, which are being developed to enhance fusion rates and reduce the complications associated with the procedure. In particular, the anterior approach is significant in LIF research and regenerative medicine studies concerning intervertebral discs, as it utilizes the disc and the entire vertebral body. Several animal models have been used for anterior LIF (ALIF), each with distinct characteristics. However, a comprehensive review of ALIF models in different animals is currently lacking. Medium-sized and large animals, such as dogs and sheep, have been employed as ALIF models because of their suitable spine size for surgery. Conversely, small animals, such as rats, are rarely employed as ALIF models because of anatomical challenges. However, recent advancements in surgical implants and techniques have gradually allowed rats in ALIF models. Ambitious studies utilizing small animal ALIF models will soon be conducted. This review aims to review the advantages and disadvantages of various animal models, commonly used approaches, and bone fusion rate, to provide valuable insights to researchers studying the spine.

The use of Three-Dimensional Printing in Orthopaedics: a Systematic Review and Meta-analysis.

3D-printing is a rapidly developing technology with applications in orthopaedics including pre-operative planning, intraoperative guides, design of patient specific instruments and prosthetics, and education. Existing literature demonstrates that in the surgical treatment of a wide range of orthopaedic pathology, using 3D printing shows favourable outcomes. Despite this evidence 3D printing is not routinely used in orthopaedic practice. We aim to evaluate the advantages of 3D printing in orthopaedic surgery to demonstrate its widespread applications throughout the field. We performed a comprehensive systematic review and meta-analysis. AMED, EMBASE, EMCARE, HMIC, PsycINFO, PubMed, BNI, CINAHL and Medline databases were searched using Healthcare Databases Advanced Search (HDAS) platform. The search was conducted to include papers published before 8th November 2020. Clinical trials, journal articles, Randomised Control Trials and Case Series were included across any area of orthopaedic surgery. The primary outcomes measured were operation time, blood loss, fluoroscopy time, bone fusion time and length of hospital stay. A total of 65 studies met the inclusion criteria and were reviewed, and 15 were suitable for the meta-analysis, producing a data set of 609 patients. The use of 3D printing in any of its recognised applications across orthopaedic surgery showed an overall reduction in operative time (SMD = -1.30; 95%CI: -1.73, -0.87), reduction in intraoperative blood loss (SMD = -1.58; 95%CI: -2.16, -1.00) and reduction in intraoperative fluoroscopy time (SMD = -1.86; 95%CI: -2.60, -1.12). There was no significant difference in length of hospital stay or in bone fusion time post-operatively. The use of 3D printing in orthopaedics leads to an improvement in primary outcome measures showing reduced operative time, intraoperative blood loss and number of times fluoroscopy is used. With its wide-reaching applications and as the technology improves, 3D printing could become a valuable addition to an orthopaedic surgeon's toolbox.

Surgical Outcome of Occipitocervical Fixation for Craniocervical Instability

OBJECTIVES To evaluate the efficacy of Occipitocervical Fixation (OCF) in patients with craniocervical instability in two tertiary care hospitals. METHODOLOGY This retrospective case series study was conducted at Hayatabad Medical Complex, Peshawar, from April 2017 to December 2020. A non-probability sampling technique was used, and size was calculated via online software with a 95 % confidence level and 5% margin of error. All patients with craniocervical instability were included in our study, and those having occipital bone fractures or previously operated patients with the same technique were excluded from the study. The Nurick score was used to assess neurological function pre-and postoperatively. The demographic details of the patients, clinical features, radiographic findings (pre- and postoperative), and clinical outcomes using the Nurick myelopathy grading system were noted and entered into a structured proforma. All data were entered into SPSS Version 18 and analyzed. The results were presented in tables and pictures. RESULTSA total of 26 cases with craniocervical instability underwent OCF. The mean age of the patients was 40.5 + 1.2 SD years. There were 10 male patients and 16 female patients. The majority of patients showed improvements in myelopathic symptoms after the operation. The mean preoperative Nurick score was 3.0. At the end of follow-up after surgery, the mean Nurick score was 2.1. There was a total of 7(14.28%) cases having complications, of which 4 (8.16%) patients had wound infection, 2 (4.08%) patients had implant failure, and 1(2.04%) had vertebral artery injury. However, no postoperative neurological deficit was observed. CONCLUSION Occipitocervical fixation is a reasonable option to have spinal stability, achieve bone fusion and get neurological improvement. Certain conditions complicate the procedure, but experienced hands can safely handle these.

Diagnosis and treatment of 11 patients with cevical spondylotic amyotrophy

To explore clinical features, treatment methods and clinical effects of cervical spondylosis with proximal muscular atrophy. Eleven patients with proximal-type cervical spondylotic amyotrophy were retrospectively studied from September 2016 to November 2020, including 7 males and 4 females, aged 38 to 68 years old. Clinical symptoms, MRI and neuroelectrophysiological manifestations were analyzed, and patients were treated with conservative treatment or anterior cervical decompression fusion surgery, respectively. The efficacy was evaluated by manual muscle test (MMT) before and after treatment, and patients' satisfaction was followed up at the same time. All patients were followed up for 6 to 19 months. All 11 patients were unilateral, mainly manifested by atrophy of deltoid muscle, supraspinatus muscle and infraspinatus muscle, and may be accompanied by ipsilateral neck and shoulder pain at early stage. MRI showed lesions at C4,5, C5,6 segments were more common. Electrophysiological examination showed the affected muscle was denervated, and amplitude of compound muscle action potential (CMAP) of innervated nerve on the affected side was lower than that on the healthy side. All patients were obtained bone fusion. One patient who were underwent anterior cervical corpectomy and fusion (ACCF) occurred developed contralateral C5 nerve root paralysis after operation, which recovered completely after 10 weeks of symptomatic treatment. At 12 months after operation, the efficacy was evaluated according to MMT, 3 patients were treated conservatively, 2 patients excellent and 1 good;in 8 patients treated by operation, 3 patients were excellent, 4 good, and 1 moderate. The incidence of cervical spondylosis with proximal muscular atrophy is low, which is manifested as unilateral proximal muscle atrophy and may be accompanied by ipsilateral neck and shoulder pain in the early stage. Combined with MRI and neuroelectrophysiological examination, misdiagnosis could be reduced. In the early stage of disease, especially in the case of nucleus pulposus protrusion leading to nerve compression, conservative treatment could be taken. When the conservative treatment is ineffective or the pain cannot be tolerated, anterior decompression surgery is recommended, and the overall effect is satisfactory.

Targeted Protein Fate Modulating Functional Microunits Promotes Intervertebral Fusion.

Stable regulation of protein fate is a prerequisite for successful bone tissue repair. As a ubiquitin-specific protease (USP), USP26 can stabilize the protein fate of β-catenin to promote the osteogenic activity of mesenchymal cells (BMSCs) and significantly increased bone regeneration in bone defects in aged mice. However, direct transfection of Usp26 in vivo is inefficient. Therefore, improving the efficient expression of USP26 in target cells is the key to promoting bone tissue repair. Herein, 3D printing combined with microfluidic technology is applied to construct a functional microunit (protein fate regulating functional microunit, denoted as PFFM), which includes GelMA microspheres loaded with BMSCs overexpressing Usp26 and seeded into PCL 3D printing scaffolds. The PFFM provides a microenvironment for BMSCs, significantly promotes adhesion, and ensures cell activity and Usp26 supplementation that stabilizes β-catenin protein significantly facilitates BMSCs to express osteogenic phenotypes. In vivo experiments have shown that PFFM effectively accelerates intervertebral bone fusion. Therefore, PFFM can provide new ideas and alternatives for using USP26 for intervertebral fusion and other hard-to-repair bone defect diseases and is expected to provide clinical translational potential in future treatments.