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.

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

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

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.

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

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

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

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

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.

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.

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.

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.

Total Loss of the Intermediate Cuneiform by Posttraumatic Avascular Necrosis: A Case Report.

We report a unique case of the total loss of the intermediate cuneiform by posttraumatic avascular necrosis resulting from a left foot open fracture and dislocation of the navicular bone and medial and intermediate cuneiforms at the Chopart and Lisfranc joints in a 64-year-old woman. The injury was managed with open reduction and internal fixation with Kirschner wires and cannulated screws. During postoperative follow-up, we observed avascular necrosis of the intermediate cuneiform and the total loss of the bone. An extensive English literature search revealed only one case report published on this topic. Thus, we provide this case study to help guide clinical decision making in the future.

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.

Is it necessary to remove syndesmotic screw before weight-bearing ambulation?

In syndesmosis injury, whether the syndesmosis screw should be removed prior to weight-bearing remains controversial. The aim of this study was to compare the functional outcome between removed screw and retained groups and between recurrence of diastasis and no diastasis groups.Fifty-six patients who had undergone open reduction and internal fixation due to syndesmosis injury were retrospectively evaluated and divided into four groups: (A) removed syndesmotic screw before weight-bearing (postoperative 3 months, n = 28), (B)retained (n = 28), (C) recurrence of diastasis (n = 9), and (D) no diastasis (n = 47). Radiological diastasis, American Orthopedic Foot Ankle Society Score (AOFAS), Short Form Health Survey-12 (SF-12), and complications (screw loosening and breakage) were evaluated between groups.AOFAS ankle-hindfoot score was 75.10 ±â€Š10.40 in group A, 77.07 ±â€Š10.60 in group B. SF-12 was 45.78 ±â€Š5.68 in group A and 47.33 ±â€Š5.83 in group B, showing no significant difference in AOFAS ankle-hindfoot score or SF-12 (P = .487, P = .319, respectively) between groups A and B. Radiological diastasis developed significantly (P = .025) more in group A (8/28) compared to that in group B (1/28). However, screw loosening or breakage developed significantly (P = .001) more in group B (4/28) compared to that in group A (0/28). AOFAS ankle-hindfoot score was 70.33 ±â€Š6.22 in group C and 76.50 ±â€Š10.26 in group D. SF-12 was 49.85 ±â€Š3.83 in group C and 47.40 ±â€Š8.01 in group D, showing no significant difference between groups C and D in AOFAS ankle-hindfoot score or SF-12 (P = .808, P = .948, respectively).Removal of syndesmotic screw before weight-bearing does not influence clinical outcomes. Although unrelated to clinical progress, recurrence of diastasis significantly increased in screw removed group. Therefore, removal of syndesmotic screw is unnecessary before weight-bearing.

Stabilized Loading of Hyaluronic Acid-Containing Hydrogels into Magnesium-Based Cannulated Screws.

Cannulated screws have a structure for inserting a guide wire inside them to effectively correct complicated fractures. Magnesium, an absorbable metal used to manufacture cannulated screws, may decompose in the body after a certain period of implantation. The hydrogel formed by hyaluronic acid (HA) and polygalacturonic acid (PGA) has been used into Mg-based cannulated screws to prevent bone resorption owing to the rapid corrosion of Mg with unfavorable mechanical properties and a high ambient pH. In addition, Ca ions were added to the gel for cross-linking the carboxyl groups to modify the gelation rate and physical properties of the gel. The developed hydrogels were injected into the Mg-based cannulated screws, after which they released HA and Ca. The possibility of the application of this system as a cannulated screw was evaluated based on the corrosion resistance, gel degradation rate, HA release, toxicity toward osteocytes, and experiments involving the implantation of the screws into the femurs of rats. Ca ions first bound to PGA and delayed the gelation time and dissolution rate. However, they interfered with HA binding and increased the elution of HA at the beginning of gel degradation. Ca(NO3)2 concentrations higher than 0.01 M and low pH environments inhibited osteoblast differentiation and proliferation, owing to the elution of HA from the hydrogel. On the other hand, when the HA hydrogel with a proper amount of Ca was inserted into a magnesium screw, the degradation of Mg was delayed, and the presence of the gel contributed to new bone formation and osteocyte expansion.

Osteogenic Effect of a Biodegradable BMP-2 Hydrogel Injected into a Cannulated Mg Screw.

Cannulated screws, containing an internal hole for inserting a guide pin, are commonly used in the management of bone fractures. Cannulated Mg screws can be biodegraded easily because their increased surface area including that of the inner hole rapidly reacts with body fluids. To delay biodegradation of cannulated Mg screws and improve bone regeneration, we developed a specific type of screw by injecting it with gelatin hydrogels [10 wt % gelatin(gel) with 0.09 v/v % glutaraldehyde (cross-linker)] containing different concentrations (5, 10, or 25 µg/mL) of bone morphogenic proteins (BMPs). We analyzed the properties and biocompatibility of the screws with and without BMP-2 and found that the release rate of BMP-2 in the hydrogel changed proportionately with the degradation rate of the cross-linked hydrogel. Loading BMP-2 in the hydrogel resulted in sustained release of BMP-2 for 25 to 40 days or more. The degradation rate of BMP-2 hydrogels was inversely proportional to the concentration of BMP-2. The injection of the hydrogels in the cannulated screw delayed biodegradation inside of the screw by simulated body fluid. It also induced uniform corrosion and the precipitation of bioactive compounds onto the surface of the screw. In addition, osteoblast proliferation was very active near the BMP-2 hydrogels, depending on the BMP-2 concentration. The BMP-2 in the hydrogel improved cell differentiation. The cannulated screw injected with 10 µL/mL BMP-2 hydrogel prevented implant biodegradation and enhanced osteoconduction and osteointegration inside and outside the screw. In addition, the properties of BMP-2-loaded hydrogels can be changed by controlling the amount of the cross-linker and protein, which could be useful for tissue regeneration in other fields.

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.

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.

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.