The aim of this study was to analyze the behavior of the porous nano-hydroxyapatite/polyamide 66 (n-HA/PA66) composite grafted for bone defect repair through a series of biological safety experiments, animal experiments, and a more than 5-year long clinical follow-up. The biological safety experiments, carried out in accordance with the Chinese Guo Biao and Tolerancing (GB/T)16886 and GB/T16175, revealed that porous n-HA/PA66 composite had no cytotoxicity, no sensitization effect, no pyrogenic reaction, and that its hemolysis rate was 0.59% (less than 5%). Rabbit models of tibia defects with grafted porous n-HA/PA66 composite were established. After 2 weeks, the experiment showed that osteogenesis was detected in the porous n-HA/PA66 composite; the density of new bone formation was similar to the surrounding host bone at 12 weeks. After 26 weeks, the artificial bone rebuilt to lamellar bone completely. In the clinical study, a retrospective review was carried out for 21 patients who underwent serial radiographic assessment after treatment with porous n-HA/PA66 composite grafts following bone tumor resection. All wounds healed to grade A. No postoperative infections, delayed deep infection, nonspecific inflammation, rejection, or fractures were encountered. At a mean follow-up of 5.3 years, the mean Musculoskeletal Tumor Society’s (MSTS) 93 score was 29.3 points (range: 28–30 points) and mean radiopaque density ratio was 0.77±0.10. The radiologic analysis showed that porous n-HA/PA66 composite had been completely incorporated with the host bone about 1.5 years later. In conclusion, this study indicated that the porous n-HA/PA66 composite had biological safety, and good biocompatibility, osteoinduction, and osseointegration. Thus, the porous n-HA/PA66 composite is an ideal artificial bone substitute and worthy of promotion in the field.

BackgroundChondroblastoma is a rare benign cartilaginous tumor, which primarily occurs in children and adolescents. Chondroblastoma commonly originates in the epiphyseal plate of long bones. An aggressive curettage treatment is recommended to manage lesion, which may jeopardize an open epiphyseal plate and result in limb shortening and deformity as the limb grows and develops. The purpose is to observe surgical effects of chondroblastoma on open epiphyseal plate of long bones in children and adolescents and explore influences on limb growth and development.MethodsWe retrospectively reviewed 18 cases of long bone chondroblastoma with open epiphyseal growth plate during March 2004 to October 2010 in our center. Seven females and 11 males with mean age of 11.6 ± 2.0 years old (8–15 years) were included. Patients, who suffered from trauma and pathological fracture of the epiphyseal plate or congenital diseases such as poliomyelitis, congenital dementia, and cartilage malnutrition, were excluded. All patients were treated with meticulous intralesional curettage and inactivity with alcohol followed by bone grafts. All cases were followed up 8.2 ± 1.7 years (5–11.5 years).ResultsAll had no local recurrence and distance metastasis. The length of the affected limb was short, 18.47 ± 7.22 mm (1.5–30 mm). There was no obvious relativity with tumor activity (P = 0.061). Meanwhile, there were obvious relativity with the greatest dimension of the lesion (TGD) (P = 0.003), the vertical dimension between edge of lesion and epiphyseal line (TVD) (P = 0.010), and area ratio of lesion to local epiphysis (lesion/growth plate) (P = 0.015). The MSTS93 (Revised Musculoskeletal Tumor Society Rating Scale 93) and SF-36 (Medical Outcomes Study 36-Item Short-Form Health Survey) had been significantly improved (P < 0.01).ConclusionManaging of chondroblastoma located in open epiphyseal plate of a long bone with meticulous curettage, inactivity, and bone grafts can control tumor progression and recurrence effectively. Meanwhile, early detection and prompt surgical treatment intervention, which reduced significantly the tumor to influence limb growth and development, get encouraging limb function.Trial registrationThis is a retrospective study, which was not registered in any trial registry.

The surgical treatment for fibrous dysplasia (FD) of bone is problematic due to its variable clinical courses. And multifarious surgical treatment options have been reported while no consistent view can be reached. Therefore, we reviewed a series of 22 patients (11 males and 11 females; mean age 28.4 years, range 15-48 years) with FD between December 2011 and July 2015. Fourteen patients had monostotic fibrous dysplasia (MFD) and eight patients had polyostotic fibrous dysplasia (PFD) with nine lesions. All patients were followed up from 15 to 58 months with an average of 26.0 months. Functional and radiographic outcomes were recorded. In the MFD group, four patients were treated with curettage and bone grafting without internal fixation and nine were treated with curettage and bone grafting with internal fixations. Osteotomy and intramedullary (IM) nail was applied in one patient with serious deformity. In the PFD group, three deformity lesions were treated with osteotomy and proximal femoral nail anti-rotation (PFNA). IM were also applied in six large lesions to treat fracture or prevent deformity. One lesion in tibia were treated with only curettage and bone graft. No complication was observed in MFD group and satisfactory union and functional outcomes acquired during follow-up period. In the PFD group, the spiral blade cutting out from femoral head in PFNA was observed in one patient and treated with revision surgery. No other complication occurred, and satisfactory radiological and functional outcome were observed. The severity of both MFD and PFD are related to size, site and of the lesion. The goal of the surgery is to eliminate pain, correct deformity and treat pathological fracture. Curettage, bone grafting with internal fixation is recommended for treating large lesions with deformity or high pathological fracture risk. PFNA or IM nail is prior in osteotomy with better clinical outcome.

BackgroundChondroblastoma is a rare primary bone tumor of young people that generally occurs in the epiphyseal plate of long bones. To date, only 13 cases of patella with pathological fracture in chondroblastoma have been previously published.Case presentationA 15-year-old male patient presented with acute pain in the left knee after an injury occurred while playing basketball. Plain radiographs and computed tomography showed a pathological fracture of the left patella with an osteolytic lesion (1.5 × 2 × 3 cm). Magnetic resonance imaging revealed an expansile lesion within the patella with a slightly high signal on the T1-weighted image, a high signal on the T2-weighted image and soft tissue swelling in front of the patella. A m99Tc bone scintigraphy revealed moderate uptake. The preoperative diagnosis was chondroblastoma. This patient underwent intralesional meticulous extended curettage, adjuvant high-speed burr, 95% alcohol and electrotome treatment, autogenous iliac crest bone grafting, and internal fixation. A postoperative pathological diagnosis was chondroblastoma. The patient’s function was satisfactory, and there was no sign of tumor recurrence. The internal fixator was good, with no loosening or migration observed at the last follow-up at 20 months after surgery.ConclusionsRarely, chondroblastoma of the patella can present with acute pain due to pathological fracture. We present the 14th such case in the literature to associate patellar chondroblastoma with pathological fracture. The patient was treated with curettage, inactivation, autogenous bone grafting, and internal fixation. A satisfactory therapeutic effect was obtained. This case may be beneficial to the diagnosis and treatment of chondroblastoma patella.

ObjectiveTo study the degradation and basic fibroblast growth factor (bFGF) release activity of bFGF – poly(lactic-co-glycolic-acid) microsphere (bFGF-PLGA MS) under stress in vitro, including the static pressure and shearing force-simulating mechanical environment of the joint cavity.MethodFirst, bFGF-PLGA MSs were created. Meanwhile, two self-made experimental instruments (static pressure and shearing force loading instruments) were initially explored to provide stress-simulating mechanical environment of the joint cavity. Then, bFGF-PLGA MSs were loaded into the two instruments respectively, to study microsphere degradation and drug release experiments. In the static pressure loading experiment, normal atmospheric pressure loading (approximately 0.1 MPa), 0.35 MPa, and 4.0 MPa pressure loading and shaking flask oscillation groups were designed to study bFGF-PLGA MS degradation and bFGF release. In the shearing force loading experiment, a pulsating pump was used to give the experimental group an output of 1,000 mL/min and the control group an output of 10 mL/min to carry out bFGF-PLGA MS degradation and drug release experiments. Changes of bFGF-PLGA MSs, including microsphere morphology, quality, weight-average molecular weight of polymer, and microsphere degradation and bFGF release, were analyzed respectively.ResultsIn the static pressure loading experiment, bFGF-PLGA MSs at different pressure were stable initially. The trend of molecular weight change, quality loss, and bFGF release was consistent. Meanwhile, microsphere degradation and bFGF release rates in the 4.0 MPa pressure loading group were faster than those in the normal and 0.35 MPa pressure loading groups. It was the fastest in the shaking flask group, showing a statistically significant difference (P<0.0001). In the shearing force loading experiment, there were no distinctive differences in the rates of microsphere degradation and bFGF release between experimental and control group. Meanwhile, microsphere degradation and bFGF release rates by shaking flask oscillation were obviously faster than those by shearing force only (P<0.0001).ConclusionThere are significant effects on bFGF-PLGA MS degradation and bFGF release due to the interaction between extraction stress and time. Static pressure has a conspicuous influence on bFGF-PLGA MS degradation and release, especially at a pressure of 4.0 MPa. The shearing force has a slight effect on bFGF-PLGA MS degradation and drug release. On the contrary, shaking flask oscillation has a significantly distinctive effect.