Multicenter study on atypical femoral fractures in patients with bone metastases taking bone- modifying agents.

Bone-modifying agents (BMAs), with bone-resorptive inhibitory effects, such as zoledronic acid and denosumab, are widely used at higher doses for bone-related events caused by bone metastasis of malignant tumors. These drugs have been suggested to be associated with atypical femoral fractures (AFFs), and the relationship between BMAs and AFFs has attracted attention. To investigate the clinical features including bone union time of AFFs in patients administered BMA for bone metastasis, we conducted a retrospective multicenter study. Thirty AFFs from 19 patients were enrolled in this study. Thirteen patients had bilateral AFFs, and nineteen AFFs had prodromal symptoms. Eighteen AFFs underwent surgery after complete fracture, three failed to achieve bone union and required nonunion surgery, and 11 AFFs that achieved bone union had an average period until bone union of 16.2 months, which was much longer than that previously reported for ordinary AFFs. Seven patients discontinued the BMAs, but not due to AFFs. Stopping BMAs in patients with bone metastasis would make it difficult to secure their performance of activities of daily living, and AFF with BMA administration might require a longer time for union. Therefore, it would be important to prevent incomplete AFF from becoming complete AFF via prophylactic internal fixation.

Altered microRNA profile during fracture healing in rats with diabetes.

BACKGROUND: MicroRNAs (miRNAs) are a class of small non-coding RNA molecules that regulate gene expression. There is increasing evidence that some miRNAs are involved in the pathology of diabetes mellitus (DM) and its complications. We hypothesized that the functions of certain miRNAs and the changes in their patterns of expression may contribute to the pathogenesis of impaired fractures due to DM. METHODS: In this study, 108 male Sprague-Dawley rats were divided into DM and control groups. DM rats were created by a single intravenous injection of streptozotocin. Closed transverse femoral shaft fractures were created in both groups. On post-fracture days 5, 7, 11, 14, 21, and 28, miRNA was extracted from the newly generated tissue at the fracture site. Microarray analysis was conducted with miRNA samples from each group on post-fracture days 5 and 11. The microarray findings were validated by real-time polymerase chain reaction (PCR) analysis at each time point. RESULTS: Microarray analysis revealed that, on days 5 and 11, 368 and 207 miRNAs, respectively, were upregulated in the DM group, compared with the control group. The top four miRNAs on day 5 were miR-339-3p, miR451-5p, miR-532-5p, and miR-551b-3p. The top four miRNAs on day 11 were miR-221-3p, miR376a-3p, miR-379-3p, and miR-379-5p. Among these miRNAs, miR-221-3p, miR-339-3p, miR-376a-3p, miR-379-5p, and miR-451-5p were validated by real-time PCR analysis. Furthermore, PCR analysis revealed that these five miRNAs were differentially expressed with dynamic expression patterns during fracture healing in the DM group, compared with the control group. CONCLUSIONS: Our findings will aid in understanding the pathology of impaired fracture healing in DM and may support the development of molecular therapies using miRNAs for the treatment of impaired fracture healing in patients with DM.

Insufficiency and deficiency of vitamin D in elderly patients with fragility fractures of the hip in the Japanese population.

BACKGROUND: Data of vitamin D sufficiency in Asian patients with osteoporotic fragility hip fractures are limited. This study aimed to obtain data from the Japanese population. METHODS: Patients aged 60 years or older with hip fractures were prospectively enrolled. Serum 25-hydroxyvitamin D (25(OH)D) levels were measured. Levels were compared between patients receiving and not receiving treatment for osteoporosis, those with and without previous contralateral hip fractures, and those with femoral neck versus trochanteric fractures. Sex-based differences were also assessed. The serum levels in patients younger than 60 years with extremity fractures were assessed, and differences between elderly and younger patients were evaluated. The individual correlation between 25(OH)D levels and the ultraviolet (UV) index and age was analyzed in elderly patients with hip fractures. RESULTS: The data of 360 patients (aged 84.7 ± 8.2 years), comprising 80 men and 280 women, were analyzed. The mean 25(OH)D level was 16.5 ± 7.2 ng/mL. The prevalence of vitamin D insufficiency (25(OH)D <30 ng/mL) and deficiency (25(OH)D <20 ng/mL) was 93.9% and 71.7%, respectively. A significant difference was noted in the prevalence of vitamin D deficiency between patients with and without previous contralateral hip fractures. Age and 25(OH)D levels were found to be correlated, with no correlation between the UV index and the 25(OH)D levels. The 25(OH)D level in the younger population (n = 123) was 20.7 ± 8.6 ng/mL, which was significantly higher than that of the elderly. CONCLUSION: Perennial vitamin D insufficiency is prevalent in elderly Japanese patients with hip fractures.

Medial clavicle pseudarthrosis successfully treated with an inverted distal clavicle locking plate.

INTRODUCTION: Medial clavicle fractures are rare injuries. Symptomatic nonunion arises up to 8% of medial clavicle fractures when treated conservatively. PRESENTATION OF CASE: A 53-year-old man sustained a left medial clavicle fracture and was treated conservatively at another hospital. Nine months after his initial injury, he was referred to our institution. We diagnosed pseudarthrosis of the medial clavicle. We performed open reduction and internal fixation using an inverted distal clavicle locking plate. At the 1-year follow-up, radiographs showed bone union. DISCUSSION: This is the first reported case of medial clavicle pseudarthrosis treated with an inverted distal clavicle anatomical locking plate. There are several advantages in using this plate. CONCLUSION: This method is a good treatment option.

Escherichia coli-derived BMP-2-absorbed ß-TCP granules induce bone regeneration in rabbit critical-sized femoral segmental defects.

PURPOSE: This study investigated whether Escherichia coli-derived bone morphogenetic protein (BMP)-2 (E-BMP-2) adsorbed onto ß-tricalcium phosphate (ß-TCP) granules can induce bone regeneration in critical-size femoral segmental defects in rabbits. METHODS: Bone defects 20 mm in size and stabilized with an external fixator were created in the femur of New Zealand white rabbits, which were divided into BMP-2 and control groups. E-BMP-2-loaded ß-TCP granules were implanted into defects of the BMP-2 group, whereas defects in the controls were implanted with ß-TCP granules alone. At 12 and 24 weeks after surgery, radiographs were obtained of the femurs and histological and biomechanical assessments of the defect area were performed. Bone regeneration was quantified using micro-computed tomography at 24 weeks. RESULTS: Radiographic and histologic analyses revealed bone regeneration in the BMP-2 group but not the control group; no fracturing of newly formed bone occurred when the external fixator was removed at 12 weeks. At 24 weeks, tissue mineral density, the ratio of bone volume to total volume, and volumetric bone mineral density of the callus were higher in the BMP-2 group than in control animals. In the former, ultimate stress, extrinsic stiffness, and failure energy measurements for the femurs were higher at 24 weeks than at 12 weeks. CONCLUSION: E-BMP-2-loaded ß-TCP granules can effectively promote bone regeneration in long bone defects.

Locking plate osteosynthesis for a femoral fracture and subsequent nonunion in a patient with osteopetrosis.

INTRODUCTION: Osteopetrosis is a skeletal disorder characterized by increased osteodensity and a remodeling defect. The fragility of dense sclerotic bones may lead to an increased incidence of fractures. Although internal fixation can be performed, technical challenges may be experienced because of the increased bone density. Complications such as delayed union, nonunion, or implant failure may occur postoperatively. PRESENTATION OF CASE: We describe a patient with autosomal-dominant osteopetrosis type 2 who suffered a shaft fracture below a plate of his right femur. We performed osteosynthesis with a single locking plate. Union was delayed, and plate breakage occurred along with nonunion of the fracture. The nonunion was addressed using double locking plates, which secured fixation and allowed complete fracture healing. DISCUSSION: There were three reasons of nonunion in our case. First, we left gaps between the fragments. Second, we used mainly cerclage wires, rather than screws, for plate fixation, which led to inadequate stability. Third, the patient was large (height 167 cm, weight 93.1 kg), so the single plate provided insufficient fixing force. We then used double locking plates and attained stronger internal fixation with complete fracture healing. CONCLUSION: Double plating with locking plates may be an effective treatment option for femoral fractures in patients with osteopetrosis.

Triweekly administration of parathyroid hormone (1-34) accelerates bone healing in a rat refractory fracture model.

BACKGROUND: Some reports have shown that intermittent parathyroid hormone (PTH) (1-34) treatment for patients with delayed union or nonunion have led to successful healing. In this study, we investigated whether systemic intermittent administration of PTH (1-34) has a beneficial effect on bone healing in a rat refractory fracture model. METHODS: We created a refractory femoral fracture model in 32 rats with periosteal cauterization that leads to atrophic nonunion at 8 weeks after surgery. Half the rats received subcutaneous intermittent human PTH (1-34) injections at a dosage of 100 µg/kg, thrice a week for 8 weeks. The other half received the vehicle only. At 8 weeks after fracture, radiographic, histological and mechanical assessments were performed. RESULTS: Radiographic assessments showed that the union rate was significantly higher in the PTH group than in the control group (P < 0.05). The degree of fracture repair as scored using the Allen grading system in histological assessment was significantly greater in the PTH group than in the control group (P < 0.05). The ultimate stress and stiffness measurements were significantly greater in the PTH group than in the control group (p < 0.05). CONCLUSIONS: We demonstrated that triweekly administration of PTH (1-34) increased union rate and accelerated bone healing in a rat refractory fracture model, suggesting that systemic administration of PTH (1-34) could become a novel and useful therapy for accelerating fracture healing in patients at high risk of delayed union or nonunion.

Clinical Experience With the Use of Low-Intensity Pulsed Ultrasound (LIPUS) in the Treatment of Atypical Femoral Fractures.

OBJECTIVE: The aim of this study was to report the clinical results of atypical femoral fractures (AFFs) treated with low-intensity pulsed ultrasound (LIPUS). MATERIALS AND METHODS: The data on AFFs that were surgically treated in our hospital from 2010 to 2016 was retrospectively analyzed. AFF was diagnosed based on the criteria defined by the second report of an ASBMR task force. RESULTS: Seven fractures in 6 cases were included in this study. Two fractures were referred to us as being nonunion. Five fractures were subtrochanteric fractures and 2 fractures were shaft fractures. Five fresh AFFs were fixed with an intramedullary nail and 2 nonunion fractures were fixed with plates. LIPUS was used in 6 fractures. Bone union was achieved in 5 fractures with the average time to union being 17 months (5-29). In 4 out of the 6 fractures treated with LIPUS, bone union was achieved after 14 months on average. In the other 2 LIPUS-treated fractures, bone union was not achieved even at 1 year after surgery. DISCUSSION: It is known that AFF healing tends to be very slow. Some case reports indicate that AFF healing might be accelerated by LIPUS. In the current series, the subtrochanteric fracture that was not treated with LIPUS healed at 29 months after surgery, which was much longer than the average time to union in the 5 fractures that were treated with LIPUS. Although our number of cases is small, LIPUS may be a potentially useful tool for accelerating AFF repair.

Thrombin-antithrombin III complex tests.

PURPOSE: Patients with fractures of the pelvis and/or lower extremities are at a high risk of developing postoperative venous thromboembolism (VTE). The purpose of this study was to determine whether the thrombin-antithrombin III complex (TAT) tests could be used for postoperative screening of VTE in patients with lower limb or pelvic fractures. METHODS: We enrolled 133 patients who underwent surgical treatment for fracture of the pelvis or lower extremities. TAT and D-dimer levels were compared in patients with and without VTE. Receiver operating characteristic (ROC) curve analysis was done and the appropriate TAT and D-dimer cutoff levels were determined for VTE screening. RESULTS: VTE was diagnosed in 41 patients (30.8%). Patients with VTE had significantly higher levels of TAT and D-dimer on postoperative days 1, 3, and 7 than those without VTE, respectively. ROC curve analysis suggested that TAT test at postoperative day 7 had the highest accuracy for predicting postoperative VTE. With the optimal cutoff TAT level of 3.0 ng/mL, sensitivity and specificity were 93.3% and 70.1%, respectively. With the optimal cutoff D-dimer level of 7.4 µg/mL, sensitivity and specificity were 93.3% and 57.0%, respectively. CONCLUSION: TAT levels measured at postoperative day 7 could be the most useful parameter for screening postoperative VTE. TAT can be used as a screening tool for screening postoperative VTE in patients with lower limb and pelvic fractures.

8. Low-Intensity Pulsed Ultrasound (LIPUS) Treatment for the Patient With Bone Reconstruction by the Masquelet Technique Using RIA.

BACKGROUND: The Masquelet technique is a relatively new option in the management of bone defects. It consists of 2-stage surgery. At first surgery, a cement spacer is placed to fill the bone defect. After a waiting period of 6-8 weeks, a pseudo-synovial membrane is formed around the cement. The induced membrane is rich in vascularity and osteogenic activity. At second surgery, the cement is replaced with an autologous bone graft and the graft is packed in the membrane. To harvest large quantities of bone graft, the reamer irrigator aspirator (RIA) is utilized. We report a case in which low-intensity pulsed ultrasound (LIPUS) was applied to bone reconstruction by the Masquelet technique using RIA. CASE: The patient was a 44-year-old man. He suffered a tibia fracture involving the proximal part and the shaft. Open reduction and internal fixation was performed at the previous hospital. However, MRSE infection was found at 6 months postoperatively and surgery to eradicate the infection was performed. Two months after surgery, pseudoarthrosis surgery was performed; however no progression in bone union was observed for 5 months. Therefore, the patient was referred to our hospital. At the first surgery in our hospital, plates and screws were removed, and the avascular bone was debrided. Vancomycin-impregnated cement was placed to fill the bone defect and an Ilizarov external fixator was applied. Eight weeks later, the cement was replaced with the autologous bone graft and the graft was packed in the induced membrane. Bone graft was harvested from the ipsilateral femur using RIA. We applied LIPUS to the affected site postoperatively. Now, 4 months after the second surgery, bone union is progressing and the patient can walk without pain. DISCUSSION: LIPUS may be used as an adjuvant therapy for a patient treated by the Masquelet technique using RIA.

Antibiotic-impregnated calcium phosphate cement as part of a comprehensive treatment for patients with established orthopaedic infection.

BACKGROUND: The treatment of established orthopaedic infection is challenging. While the main focus of treatment is wide surgical debridement, systemic and local antibiotic administration are important adjuvant therapies. Several reports have described the clinical use of antibiotic-impregnated calcium phosphate cement (CPC) to provide local antibiotic therapy for bone infections. However, these were all individual case reports, and no case series have been reported. We report a case series treated by a single surgeon using antibiotic-impregnated CPC as part of a comprehensive treatment plan in patients with established orthopaedic infection. METHODS: We enrolled 13 consecutive patients with osteomyelitis (n = 6) or infected non-union (n = 7). Implantation of antibiotic-impregnated CPC was performed to provide local antibiotic therapy as part of a comprehensive treatment plan that also included wide surgical debridement, systemic antibiotic therapy, and subsequent second-stage reconstruction surgery. We investigated the rate of successful infection eradication and systemic/local complications. The concentration of antibiotics in the surgical drainage fluids, blood, and recovered CPC (via elution into a phosphate-buffered saline bath) were measured. RESULTS: The mean follow-up period after surgery was 50.4 (range, 27-73) months. There were no cases of infection recurrence during follow-up. No systemic toxicity or local complications from the implantation of antibiotic-impregnated CPC were observed. The vancomycin concentration in the fluid from surgical drainage (n = 6) was 527.1 ± 363.9 µg/mL on postoperative day 1 and 224.5 ± 198.4 µg/mL on postoperative day 2. In patients who did not receive systemic vancomycin therapy (n = 3), the maximum serum vancomycin level was <0.8 µg/mL. In vitro vancomycin elution was observed from the CPC that was surgically retrieved (n = 2). CONCLUSIONS: Implantation of antibiotic-impregnated CPC is an option to provide local antibiotic therapy as part of a comprehensive treatment plan.

Treatment of ununited femoral neck fractures in young adults using low-intensity pulsed ultrasound: Report of 2 cases.

INTRODUCTION: Delayed union and non-union of displaced femoral neck fractures remains a difficult clinical problem for orthopaedic surgeons. In the physiologically young patient, every effort should be made to preserve the native hip joint. We present two cases of ununited femoral neck fractures in young adults who were successfully treated with low-intensity pulsed ultrasound (LIPUS) and showed satisfactory results. PRESENTATION OF CASE 1: A 41-year-old woman was involved in a motor vehicle crash and was diagnosed with displaced femoral neck fracture. Eleven months after internal fixation, a computed tomography (CT) scan revealed the presence of non-union of the femoral neck. LIPUS treatment was therefore initiated. After eight months, the fracture was completely consolidated. PRESENTATION OF CASE 2: A 39-year-old man was involved in a cycling accident and was diagnosed with displaced femoral neck fracture. Thirteen weeks after internal fixation, a CT scan revealed delayed union of the femoral neck. LIPUS treatment was therefore initiated. After six months, the fracture was completely consolidated. CONCLUSION: We suggest use of LIPUS as a possible treatment approach for delayed union and non-union of displaced femoral neck fractures in young patients before considering further surgical intervention.

Rate of venous thromboembolism after complex lower-limb fracture surgery without pharmacological prophylaxis.

PURPOSE: To evaluate the rate of venous thromboembolism (VTE) after complex lower-limb fracture surgery without pharmacological prophylaxis. METHODS: Between July 2005 and April 2009, 11 men and 6 women (mean age, 45 years) underwent temporary external fixation followed by internal fixation for a total of 3 femoral and 20 tibial fractures. Patients were screened for VTE using contrast-enhanced computed tomography (CT) when the D-dimer value was beyond normal range. Between May 2009 and December 2012, 18 men and 4 women (mean age, 45 years) underwent temporary external fixation followed by internal fixation for a total of 8 femoral and 20 tibial fractures. Patients were routinely screened for deep vein thrombosis (DVT) using ultrasonography and for pulmonary embolism (PE) using contrast-enhanced CT (in high-risk patients with multiple injuries or pelvic and acetabular fractures). In both groups, pharmacological prophylaxis was not used; only mechanical prophylaxis was used. RESULTS: The 2 groups were comparable in terms of age, sex, and proportion of bilateral external fixation, open fracture, and associated injury, except that the duration of external fixation was longer in the early group (29.8±28.0 vs. 11.6±4.0 days, p=0.001). Of the 17 patients in the early group, 5 developed VTEs (3 DVTs and 2 PEs) at a mean of 13.6 (range, 6-20) days after injury; 2 of whom developed VTE during the external fixation period. Of the 22 patients in the later period, 10 developed VTEs (10 DVTs and 4 PEs) at a mean of 13 (range, 5-33) days after injury; 7 of whom developed VTE during the external fixation period. CONCLUSION: The rate of VTE was high in patients undergoing complex lower-limb fracture surgery without pharmacological prophylaxis.

D-dimer levels to screen for venous thromboembolism in patients with fractures caused by high-energy injuries.

BACKGROUND: The clinical relevance of D-dimer levels when screening for venous thromboembolism (VTE) in elderly patients with a hip fracture has been reported but has not been fully investigated in patients with fractures caused by high-energy injuries. The purpose of this study was to evaluate the usefulness and limitations of D-dimer in such patients. METHODS: We enrolled 80 consecutive patients who underwent surgical treatment for fracture of the pelvis or lower extremity caused by high-energy injuries. None had received pharmacological prophylaxis for VTE. All patients underwent routine ultrasonography preoperatively and postoperatively (average 6.1 days after injury and 7.8 days after surgery). Contrast-enhanced computed tomography was performed routinely at the same time points for patients with a pelvic fracture or multiple fractures. D-dimer levels were compared in patients with and without VTE. Receiver operating characteristic (ROC) curve analysis was done and the appropriate D-dimer cutoff level determined for VTE screening. RESULTS: VTE was diagnosed in 34 of the 80 patients. D-dimer levels were significantly higher in patients with VTE than without it at almost all time points preoperatively and postoperatively except in patients with an isolated lower extremity fracture. ROC curve analysis suggested moderate to high accuracy for predicting VTE in patients with a pelvic fracture or multiple fractures preoperatively and postoperatively. Cutoff levels with high sensitivity and specificity for patients with a pelvic fracture or multiple fractures were set at around 7 days after the injury and surgery. CONCLUSIONS: D-dimer can be used as a VTE screening tool in patients with fractures caused by high-energy injuries. Our results suggested that D-dimer analysis to predict VTE was useful in patients with a pelvic fracture or multiple fractures. Our results also suggested that it was less useful for predicting VTE in patients with an isolated lower extremity fracture.

Comparative analysis of rat mesenchymal stem cells derived from slow and fast skeletal muscle in vitro.

PURPOSE: Skeletal muscle comprises different kinds of muscle fibres that can be classified as slow and fast fibres. The purpose of this study was to compare the yield, proliferation, and multi-potentiality of rat mesenchymal stem cells (MSCs) from the tibialis anterior (TA; fast muscle) and soleus (SO; slow muscle) in vitro. METHODS: The TA and SO muscles were harvested, and isolated cells were plated. After two hours, the cells were washed extensively to remove any cell that did not adhere to the cell culture plate. The adherent cells, namely MSCs, were then cultured. Both types of MSCs were differentiated toward the osteogenic, chondrogenic and adipogenic lineages using lineage specific induction factors. RESULTS: The colony-forming unit fibroblast (CFU-F) assay revealed that the SO contained significantly higher quantities of MSCs than the TA. The self-renewal capacity of MSCs derived from the TA was significantly higher at later passages (passage 9-11). Both types of MSCs exhibited similar cell surface antigens to bone marrow (BM)-derived MSCs and were positive for CD29, CD44, and CD90 and negative for CD11b, CD34, and CD45. TA-derived MSCs were superior in terms of osteogenic differentiation capacity, but there was no significant difference in chondrogenic and adipogenic differentiation capacity. CONCLUSION: Our results demonstrated significant differences in the properties of muscle-derived MSCs from different muscle types (i.e. fast or slow muscles). The greater expandability and osteogenic differentiation ability of TA-derived MSCs suggests that fast muscle may be a better source for generating large numbers of MSCs for bone regeneration.

Topical cutaneous CO2 application by means of a novel hydrogel accelerates fracture repair in rats.

BACKGROUND: We previously demonstrated that topical cutaneous application of CO2, by means of a hydrogel in which the CO2 readily dissolves, increases blood flow and oxygen dissociation from hemoglobin in the soft tissues surrounding bone. In the present study, we utilized a rat fracture model to test the hypothesis that application of this treatment to fractured limbs would accelerate fracture repair. METHODS: A closed femoral shaft fracture was created in each rat. Topical cutaneous application of CO2 by means of a hydrogel was performed five times a week for up to four weeks in the CO2/hydrogel group (n = 60). Sham treatments were performed in the control group (n = 60). Radiographic, histological, immunohistochemical, laser Doppler perfusion imaging, real-time polymerase chain reaction, and biomechanical assessments were performed. RESULTS: Radiographic fracture union was evident at week 3 in twelve (86%) of fourteen animals in the CO2/hydrogel group compared with five (36%) of fourteen in the control group (p < 0.05; 95% CI [confidence interval] for the difference in union rate, 2.26% to 99.64%). Histological assessment revealed promotion of endochondral ossification in the CO2/hydrogel group. Immunohistochemical assessment at week 2 showed significantly greater capillary density in the CO2/hydrogel group (p < 0.05; 95% CI for the difference, 161 to 258 per mm(2)). Laser Doppler perfusion imaging demonstrated that the blood flow in the fractured limb was significantly greater at weeks 2 and 3 in the CO2/hydrogel group (p < 0.05; 95% CI for the difference, 8.4% to 22.4% and 6.7% to 19.0%, respectively). Gene expression of chondrogenic, osteogenic, and angiogenic markers was significantly greater in the CO2/hydrogel group at several time points. Ultimate stress, extrinsic stiffness, and failure energy (relative to the contralateral limb) were significantly greater in the CO2/hydrogel group at week 3 (p < 0.05; 95% CI for the difference, 24.8% to 67.5%, 4.0 % to 22.7%, and 9.6% to 58.8%, respectively). There were no significant differences between the groups with respect to any outcome measure at week 4. CONCLUSIONS: Topical cutaneous application of CO2 by means of a hydrogel accelerated fracture repair in association with the promotion of angiogenesis, blood flow, and endochondral ossification. .

Traumatic subchondral fracture of the femoral head in a healed trochanteric fracture.

An 82-year-old woman sustained a trochanteric fracture of the left femur after a fall. Fracture fixation was performed using proximal femoral nail antirotation (PFNA) II, and she was able to walk with a T-cane after 3 months. Eleven months following the operation, the patient presented with left hip pain after a fall. Radiographs showed a subchondral collapse of the femoral head located above the blade tip. The authors removed the PFNA-II and subsequently performed cemented bipolar hemiarthroplasty. Histological evaluation of the femoral head showed osteoporosis with no evidence of osteonecrosis. Repair tissue, granulation tissue and callus formation were seen at the collapsed subchondral area. Based on these findings, a traumatic subchondral fracture of the femoral head in a healed trochanteric fracture was diagnosed. A traumatic subchondral fracture of the femoral head may need to be considered as a possible diagnosis after internal fixation of the trochanteric fracture.

No difference between double-high insert and medial-pivot insert in TKA.

PURPOSE: To compare the clinical midterm results in ADVANCE total knee arthroplasty (TKA) with double-high (DH) insert, with same type implant with medial-pivot (MP) insert. METHOD: Forty ADVANCE TKAs were randomly divided into two groups, and two different design insert, DH insert, and MP insert were used in each group. At midterm, 4-5 years after surgery, Knee Society Scores (KSS), Knee Society Functional Scores (KSFS), range of motion (ROM), and UCLA activity score were assessed and reported in this study. RESULTS: Midterm clinical results, including ROM and KSS, were comparable with both groups. KSFS and UCLA activity score were equally good between the two groups. CONCLUSION: The results in this study revealed equally good clinical results with these types of implants at midterm follow-up, although the significant better ROM has not achieved by using DH insert. We concluded that the selection of inserts only could not achieve the better clinical results, including ROM and activity level in this study. LEVEL OF EVIDENCE: Therapeutic studies-investigating the results of treatment, Level II.

Gentamycin-impregnated calcium phosphate cement for calcaneal osteomyelitis: a case report.

We report a case of chronic calcaneal osteomyelitis in a diabetic patient who was successfully treated with radical debridement and gentamycin-impregnated calcium phosphate cement. At 1.5-year follow-up, the patient could walk without any assistance. Calcium phosphate cement is an effective local antibiotic delivery system and a biocompatible material for filling the debrided space to facilitate bone formation.

Induction of chondrogenesis and expression of superficial zone protein in synovial explants with TGF-ß1 and BMP-7.

Superficial zone protein (SZP) functions as a boundary lubricant in articular cartilage and decreases the coefficient of friction. As lubrication of articular cartilage is critical for normal joint function, the ability to secrete SZP at the surface of tissue-engineered cartilage is a prerequisite for optimal lubrication. Synovium-derived mesenchymal stem cells (MSCs) are thought to be an attractive cell source for cartilage regeneration. However, optimization of a three-dimensional environment is necessary for tissue engineering. In this study, we investigated whether synovial explants, which would preserve the physiologic microenvironment for MSCs therein, have the potential of SZP secretion after chondrogenic differentiation by treatment with transforming growth factor-ß1 (TGF-ß1) and bone morphogenetic protein-7 (BMP-7). Immunostaining and enzyme-linked immunosorbent assay analysis demonstrated that synovial explants can synthesize and secrete SZP following chondrogenic differentiation in response to TGF-ß1 and BMP-7. Interestingly, the combined treatment with TGF-ß1 and BMP-7 or treatment first with TGF-ß1 followed by BMP-7 was more effective than other treatment groups in both chondrogenic differentiation and SZP secretion. In conclusion, synovial explants represent not only a superb source of progenitors/stem cells for the regeneration of the surface zone of articular cartilage, but also a useful model system for the in vitro differentiation into mature articular cartilage phenotypes in response to morphogens for tissue engineering of articular cartilage.