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.

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 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.

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.

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.

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.

Use of Lesser Trochanter Profile as a Rotational Alignment Guide in Intramedullary Nailing for Femoral Shaft Fracture.

BACKGROUND: Malrotation after nailing of femoral shaft fractures occurs in about 25% of cases. It can cause substantial functional problems. The lesser trochanter (LT) profile has been used to assess rotational alignment. However, the extent to which the LT profile is symmetrical between limbs, whether the LT profile varies as a function of age or sex, and the efficacy of the LT profile technique remain unknown. The purpose of this study was to determine if there was a significant side-to-side length difference in the LT profile (LTD) according to age and sex. METHODS: We attempted to determine the amount of medial prominence of the lesser trochanter relative to the medial cortex of the femoral shaft (the LT profile) using 3-dimensional computed tomography (3D-CT) images of normal femora obtained bilaterally (366 subjects) in anatomic positions. We also compared the left and right sides to determine the amount of natural asymmetry by age and sex. In addition, we compared the side-to-side difference in the LT version with the LTD to determine whether the LTD represented the difference in femoral rotation. RESULTS: The LTD was <4 mm (meaning an LT version difference of <10°) in 83% of the subjects, but was ≥4 mm (an LT version difference of ≥10°) in 17%. Subset analysis demonstrated that the differences were greatest in women >70 years of age. The largest LTD (both sexes) was observed in individuals over 70 years of age (2.62 ± 1.37 mm, compared with <55 years: 1.55 ± 1.36 mm and 55 to 70 years: 2.27 ± 1.70 mm). There was no significant difference between sexes in the under-70 age groups. However, the LTD was significantly greater in women over 70 years than in men over 70 years (3.10 ± 1.42 versus 2.41 ± 1.30 mm). CONCLUSIONS: Since the LTD demonstrated side-to-side symmetry within 4 mm, or 10° of rotation, in 83% of all subjects, we consider the LT profile to be useful as a guide to assess rotational reduction clinically. However, surgeons should recognize that, in 17% of cases, using this technique could result in malrotation of ≥10°. The rate of malrotation may be even higher in women over 70, for whom supplemental techniques to ensure correct rotation may be appropriate.

Irreducible Lisfranc injury by tibialis anterior tendon entrapment: A case report.

RATIONALE: Lisfranc injuries are a dislocation of the metatarsal bones from the tarsal bone. Although closed reduction is possible in most cases of Lisfranc injury when attempted in the early stage, there are some rare cases for which open reduction is required. Herein we report a case of irreducible Lisfranc injury in a 34-year-old man who presented to our institution with painful swelling. PATIENT CONCERNS: We report a 34-year-old man presented to our institution with painful swelling after a fall from 1.0 m height. DIAGNOSES: We diagnosed it as irreducible Lisfranc injury by tibialis anterior tendon entrapment through plain radiologic study and surgical findings. INTERVENTIONS: Plain X-ray, C-arm fluoroscopy and open surgery were performed. OUTCOMES: We did a closed reduction under a C-arm fluoroscopic guide, but it was not successful. Thus, we had to do an open reduction of a Lisfranc dislocation. Upon exposure, we observed the entrapment of the tibialis anterior tendon between the medial and intermediate cuneiform bones. LESSONS: Our report is valuable in that it can contribute to the diagnosis and suggest a clue to the treatment of such a rare pathology. The knowledge in the rare case of entrapment of the tibialis tendon and the understanding of management will be useful when a irreducible Lisfranc dislocation is unsuccessful after an attempt at closed reduction.

Effect of bone morphogenetic protein-2/hydroxyapatite on ankle fusion with bone defect in a rabbit model: a pilot study.

BACKGROUND: Revision ankle-fusion surgery after a failure of total ankle arthroplasty has a problem with bone-defect management by implant removal. For the reconstruction of bone defects, autogenous bone often causes minor and major complications. Recombinant human-bone morphogenetic protein-2 (rhBMP-2) plays essential roles in bone regeneration strategies, and hydroxyapatite (HA) is beneficial as the rhBMP-2 carrier. In this study, we evaluate whether rhBMP-2/HA can replace autogenous bone in a rabbit ankle-fusion model with distal tibia bone defect. METHODS: The bone defect was created in the distal tibia. The ankle fusion was performed by a cannulated screw from lateral malleolus and various treatments on bone defect. Thirty male white New Zealand rabbits were divided into three groups of 10 animals on each group dependent on treatment methods as control group (no treatment into defect), auto-bone group (autogenous bone treatment), and rhBMP-2/HA group (40 µL of 1 µg/mL rhBMP-2/100 µL HA). Bone formation on defect and the union of the ankle joint were evaluated by X-ray, micro-CT, and histological analysis at 8 weeks and 12 weeks, postoperatively. RESULTS: Radiographic assessment found the control and auto-bone groups still had the bone defect present, but rhBMP-2/HA group showed complete replacement of the defect with newly formed bone at 12 weeks. Micro-CT showed significantly higher new bone formation within the defect in the rhBMP-2/HA group than in the auto-bone and control groups at 8 weeks (p > 0.05 and p < 0.01, respectively) and 12 weeks (p < 0.05, p < 0.001, respectively). Fusion rate (%) analysis of micro-CT showed a higher percentage of union in the rhBMP-2/HA group than in the auto bone and control groups at 8 weeks (p > 0.05, p < 0.001, respectively) and 12 weeks (p < 0.001 and p < 0.001, respectively). The histological showed the highest osteointegration between distal tibia and talus in the rhBMP-2/HA group at 12 weeks. CONCLUSIONS: This study indicated that rhBMP-2/HA showed much better bone fusion than did the autogenous bone graft and was effective in promoting fusion rate and improving the quality of the ankle joint fusion.

Multiple calcaneal fibrous dysplasia: A case report.

RATIONALE: Fibrous dysplasia (FD) is a benign bone tumor due to developmental failure in the process of primitive bone remodeling to mature lamellar bone. The most common locations of monostotic FD of the extremity bones are the proximal femur, tibia, humerus and the radius. FD in the calcaneus is extremely rare and usually manifests clinically as a single bone lesion. Moreover, no research has reported on multiple lesions in calcaneal FD. PATIENT CONCERNS: We report a 21-year-old man presented to our institution with pain upon walking for 2 months. DIAGNOSES: We diagnosed the patient with multiple calcaneal FD through histologic examination of the excised biopsy that revealed cellular, spindly stroma and woven bone without osteoblastic rimming resembling Chinese characters INTERVENTIONS:: Plain X-ray, computed tomography, magnetic resonance imaging and histologic examination. An excisional biopsy with extended curettage and bone grafting with allogenous bone and autogenous bone marrow aspirate concentrate were performed. OUTCOMES: No complications developed after surgery and during serial follow-ups at 3, 6 and 12 months. At a postoperative 12-month follow-up, a plain radiogram showed a well-consolidated bone graft in the lesions. LESSONS: Calcaneal FD is rare disease entity. This case can help guide clinical decision-making in the future.

Crystal-Induced Arthritis After Total Ankle Arthroplasty.

The causes of late-onset pain after total ankle replacement (TAR) are various, and include infection, subsidence, polyethylene spacer failure, osteolysis, and wear. There are few reports of late-onset pain caused by gouty attacks after total knee and hip arthroplasty. In addition, no research has reported gouty attacks after total ankle arthroplasty. Therefore, we report a case of a gouty attack after total ankle replacement. A 43-year-old man presented with pain after total ankle arthroplasty performed 5 years previously. We found a white-yellow crystalline deposit within the synovial tissue during ankle arthroscopy, confirmed by histologic examination.

Radiographic and histologic effects of bone morphogenetic protein-2/hydroxyapatite within bioabsorbable magnesium screws in a rabbit model.

BACKGROUND: Hydrogen gas formed by magnesium (Mg) screw corrosion can accumulate around the implant and create bone cysts, long-term osteolysis lesions, and bone healing delay. Thus, several authors currently do not recommend Mg implants for clinical use. In contrast, bone morphogenetic proteins (BMP)-2 have a very strong osteoinductive activity. The purpose of this study was to evaluate the effect of rhBMP-2/hydroxyapatite (HA) inside specially designed Mg cannulated screws in a rabbit femur model for hydrogen gas formation avoidance. METHODS: Fifteen rabbits underwent randomly different cannulated Mg screw implantation in both distal femora; 30 femora were divided into three groups depending on the materials fill in the cannulated Mg screw: control group (Mg screw with no treatment), HA group (Mg screw with HA), and BMP-2/HA group (Mg screw with a composite BMP-2/HA). Plain radiography, micro-CT, and histological analysis were accomplished, and the ability to release BMP-2 of the screws was evaluated by immersion of both the screw with no treatment and screw with a composite BMP-2/HA into the SBF for up to 7 days. RESULTS: X-ray assessment found the gas shadow around the implant was slightly smaller in the BMP-2/HA group than the HA and control groups at 8 weeks. Micro-CT analysis demonstrated statistically significant higher new bone formation in the BMP-2/HA group than the other groups, respectively, which also correlated with a decreased gas volume. Histological analysis showed higher osteointegration between implants and host femurs in the BMP-2/HA group than the HA and control groups at 12 weeks. CONCLUSIONS: This study indicates that the combination of BMP-2/HA within Mg screws enhances new bone formation and therefore has the potential to decrease the complications of hydrogen gas formation around these implants.

Arthroscopic Microfracture for Traumatic Arthritis of Lateral Tarsometatarsal Joints A Case Report.

Conservative treatment is generally successful in treating early tarsometatarsal joint arthritis. However, if such treatment fails, invasive arthrodesis or arthroplasty may be needed. Arthroscopy is a less invasive alternative and can provide a precise diagnosis of early osteoarthritis or cartilage injury. Furthermore, arthroscopic treatments such as microfracture, chondroplasty, or loose-body removal are expected to delay progression of the osteoarthritis. We describe a 52-year-old man with early tarsometatarsal joint arthritis after calcaneal fracture healing who underwent a successful arthroscopic microfracture for cartilage defects. Arthroscopic findings show cartilage defects on the fourth and fifth tarsometatarsal joints. The patient underwent shaving and microfracture. The patient continues to experience effective symptom relief 3 months after 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.

Extra-Articular Soft-Tissue Calcification After Burn Injury: A Case Study.

Soft-tissue calcifications after burn injury commonly develop in periarticular regions, especially in the elbow joint. They can be easily recognized in patients because calcification in the joint limits range of motion and brings about tingling sensation due to compression of ulnar nerve. However, the incidence of extra-articular soft-tissue calcification after burn injury has rarely been reported. We present a patient with massive soft-tissue calcification in extra-articular burn scar with nonhealing ulcer after a long latency period of 40 years. We recommended wide excision and skin grafting, for prevention of recalcification and recurrence of ulceration, which could transform into a malignant case, if left untreated. Furthermore, we propose that such patients with burn injury should undergo follow-up in outpatient clinic and x-ray evaluation.

Overexpression of SIRT1 prevents hypoxia­induced apoptosis in osteoblast cells.

Hypoxic­ischemic injury of the bone results in osteonecrosis. Nicotinamide adenosine dinucleotide (NAD)­dependent deacetylase sirtuin­1 (SIRT1), a type of NAD­dependent deacetylase, is involved in multiple biological functions, particularly in anti­apoptosis. However, the effects of SIRT1 in osteoblasts remain unclear and whether SIRT1 protects osteoblasts in hypoxic conditions remains to be elucidated. In the present study, the role of SIRT1 in the osteoblast cells under hypoxia and the underlying mechanism of the anti­apoptotic activity of SIRT1 were investigated. MC3T3­E1 osteoblast cells were used for the present study and oxygen­absorbing packs were used to induce cell hypoxia and apoptosis. MC3T3­E1 cells were overexpressed SIRT1 by transfection with a SIRT1 adenovirus. The small interfering RNA of SIRT1 to was used to transfect cells to decrease the protein level. An MTT assay was used to estimate cell viability. Apoptosis was examined with the APOPercentage apoptosis assay kit and the activity of caspases was measured by a caspase 3 and 7 activity kit. Co­immunoprecipitation was used to investigate protein binding ability. The mRNA and protein expression levels were quantified with reverse transcription­quantitative polymerase chain reaction and immunoblotting. It was demonstrated that the expression of SIRT1 mRNA and protein were elevated, and peaked at 12 h under hypoxic conditions. The data demonstrated that SIRT1 overexpression in cells significantly increased cell viability and markedly decreased the percentage of apoptosis compared with the control and knockdown groups. Furthermore, overexpression of SIRT1 significantly activated anti­apoptotic effects by deacetylating lysine residue binding to protein kinase B and decreasing the activity of caspases 3, 9 and subsequent pathways. The results from the present study suggested that SIRT1 may serve a protective function in hypoxia­induced apoptosis in MC3T3­E1 cells, and that SIRT1 intervention may potentially aid in the treatment of ischemic bone disease.

An Anesthesia, Surgery, and Harvest Method for the Evaluation of Transpedicular Screws Using an In Vivo Porcine Lumbar Spine Model.

Pedicle screw fixation is the gold standard for the treatment of spinal diseases. However, many studies have reported the issue of loosening pedicle screws after spinal surgery, which is a serious concern. To address this problem, diverse types of pedicle screws have been examined to identify those with good fixation strength and osseointegration in spine bone. The porcine spine is a good alternative for the human spine in the evaluation of pedicle screws due to the anatomical size, mechanical characteristics, and cost. Although several studies have reported that pedicle screws are efficient in the porcine model, no study has described detailed protocols for the evaluation of a pedicle screw using the porcine model. Here, we describe a detailed method for evaluating transpedicular screws using an in vivo porcine lumbar spine model. The technical details for anesthesia, spine surgery, and harvest provided here will facilitate with the evaluation of the transpedicular screw fixation model.

Efficacy of Escherichia coli-derived recombinant human bone morphogenetic protein-2 in posterolateral lumbar fusion: an open, active-controlled, randomized, multicenter trial.

BACKGROUND CONTEXT: The efficacy and safety of recombinant human bone morphogenetic protein-2 (rhBMP-2) as a bone graft substitute in spinal fusion has been widely researched. However, no study of the efficacy and safety of Escherichia coli-derived rhBMP-2 (E.BMP-2) with a hydroxyapatite (HA) carrier has been proposed. PURPOSE: This study aimed to compare the efficacy and safety of fusion materials between E.BMP-2 and autogenous iliac bone graft in posterolateral fusion (PLF). STUDY DESIGN/SETTING: An open, active-controlled, randomized, multicenter trial was carried out. PATIENT SAMPLE: This study included 93 patients who underwent single-level lumbar or lumbosacral PLF. OUTCOME MEASURES: The primary outcome measure was computed tomography (CT)-based fusion rate at 12 and 24 weeks. Secondary outcome measures were fusion grade by radiographs and CT at 12 and 24 weeks and changes in Oswestry Disability Index (ODI), Short Form-36 (SF-36) Health Survey, and visual analogue scale (VAS). METHODS: Patients who underwent 1-level PLF (between L1 and S1) for severe spinal stenosis or grade 1 spondylolisthesis were randomized to receive E.BMP-2 with an HA carrier (E.BMP-2 group) or autogenous iliac bone graft (AIBG group). Thin-section CT (<2 mm), VAS, ODI, and SF-36 were obtained pre- and postoperatively at 12 and 24 weeks. Outcome measures were compared between the groups. RESULTS: A total of 100 patients were enrolled in this trial. Among them, 93 patients underwent planned surgery. Preoperative demographic and clinical data showed no difference between groups. CT-based fusion rates were 100.0% (41/41) for the E.BMP-2 group and 90.2% (46/51) for the AIBG group (p=.062) at 12 weeks and 100.0% (41/41) and 94.1% (48/51) (p=.251) at 24 weeks, respectively. Fusion grade based on radiographs and CT showed non-inferiority of the E.BMP-2 group compared with the AIBG group. All clinical parameters improved postoperatively. However, there was no difference in changes in VAS, ODI, or SF-36 between the groups. No serious adverse event related to E.BMP-2 was found. CONCLUSIONS: The fusion rate of E.BMP-2 was comparable with that of AIBG following PLF. Good clinical efficacy and safety of E.BMP-2 in spinal fusion were also revealed. It was also suggested that HA shows suitability as a carrier for E.BMP-2. Thus, E.BMP-2 with an HA carrier can be an alternative bone graft material in spinal fusion.