Comprehensive performance domain tolerance analysis methodology for freeform imaging spectrometers.

In recent years, attention has been directed towards cost-effective and compact freeform Schwarzschild imaging spectrometers with plane gratings. The utilization of tolerance analysis serves as a potent approach to facilitate the development of prototypes. Conventional tolerance analysis methods often rely solely on the modulation transfer function (MTF) criterion. However, for a spectrometer system, factors such as the keystone/smile distortion and spectral resolution performance also require consideration. In this study, a tailored comprehensive performance domain tolerance analysis methodology for freeform imaging spectrometers was developed, considering vital aspects such as the MTF, keystone/smile distortion, and spectral resolution. Through this approach, meticulous tolerance analysis was conducted for a freeform Schwarzschild imaging spectrometer, providing valuable insights for the prototype machining and assembly processes. Emphasis was placed on the necessity of precise control over the tilt and decenter between the first and third mirrors, whereas the other fabrication and assembly tolerances adhered to the standard requirements. Finally, an alignment computer-generated hologram (CGH) was employed for the preassembly of the first and third mirrors, enabling successful prototype development. The congruence observed between the measured results and tolerance analysis outcomes demonstrates the effectiveness of the proposed method.

Design of "turn-off" luminescent Ln-MOFs for sensitive detection of cyanide anions.

Two novel 2D lanthanide metal-organic frameworks (Ln-MOFs), namely {[Eu2(DBTA)3(DMF)2]·DMF}n (1) and {[Tb2(DBTA)3(DMF)2]·DMF}n (2) (H2DBTA = 2,5-dibromoterephthalic acid), have been successfully synthesized by the solvothermal method. Single-crystal X-ray diffraction results proved that the complexes possess the same topological structure of a (42·6)2(42·84)(47·63)2-connected net. The recognition of CN- from interfering anions with a low detection limit by "turn-off" luminescence makes them promising candidates for the highly selective and sensitive detection of the cyanide ion. The Ln-MOFs 1 and 2 exhibit excellent chemical sensing properties for CN- with efficiency, selectivity, and excellent performance in various mixed anions. The evaluation parameters, including the quenching constant and detection limit, have been investigated to obtain the detection performance for CN-.

Clinical Guideline for Microwave Ablation of Bone Tumors in Extremities.

Microwave ablation has been used to treat bone tumors in extremities for more than 30 years. With improved recognition, updated microwave equipment, and expanded clinical application, microwave ablation has recently been widely used to treat bone tumors. To standardize the application of microwave ablation in the clinical treatment of bone tumors in the limbs, research results and clinical experience involving the use of microwave ablation to treat bone tumors in the limbs have been summarized, and a clinical guideline has been designed. This guideline is aimed at providing a reliable clinical basis for indications, preoperative evaluation and decision-making, perioperative treatment, complications, and other issues via evidence-based medicine. Two aspects are considered-percutaneous microwave ablation and intraoperative microwave ablation of bone tumors in extremities. Ultimately, the guideline is intended to standardize treatment and improve the clinical efficacy of microwave ablation of bone tumors in extremities.

En bloc resection, intraoperative extracorporeal irradiation and re-implantation of involved bone for the treatment of limb malignancies.

Reconstruction of the defect following limb-sparing resection of malignant bone tumors is controversial and extremely challenging. Extracorporeal irradiation (ECI) and re-implantation have been used for limb salvage surgery for patients, with major advantages, including biological reconstruction, ready availability and preservation of bone stock, over replacement with a megaprosthesis. The purpose of the present study was to present our experience and details of all patients treated with this surgery. Between June 2005 and December 2014, we followed-up 23 patients with limb malignancies who were treated with en bloc excision followed by 50-Gy single dose ECI and re-implantation of involved bone segments. All cases were evaluated based on clinical and radiological examinations, complications and Musculoskeletal Tumor Society (MSTS) score. Mean follow-up period was 77.6 months (range, 17-116 months). A total of 17 patients (73.9%) demonstrated no evidence of disease, 5 (21.7%) patients succumbed to the disease and 1 (4.3%) patient was alive with the disease at the final follow-up. Local recurrence occurred in 3 patients (recurrence rate, 13.0%) in the bed outside of the irradiated graft, and 4 of the 5 patients that lost their lives did so due to associated metastatic disease. The mean value of the MSTS score was 78.8% (50-93.3%). The majority of patients demonstrated solid bony union; however, 3 patients had non-union (13.0%) and 1 had a delayed union (4.3%). Early or late complications occurred in 11 patients (47.8%). Although the complication rate (47.8%) and re-operation rate (39.1%) were high, ECI and re-implantation may be a useful and cheap technique following en bloc resection for limb salvage in appropriately selected patients.

Tissue-engineered bone treating simple bone cyst--a new strategy.

BACKGROUND: The pathological fracture is a most important complication during bone cyst and can be prevented by early focus clearance and bone grafting. Tissue-engineered bone (TEB) with outstanding osteogenesis is a better choice for bone repair. Here, we firstly reported that TEB was used to heal bone cyst. MATERIALS AND METHODS: The clinical data were collected from 23 patients who received bone defect repair separately with TEB or allogeneic bone (Allo-B) after erasion during 2004-2008. Allo-B had been as a control. The healing time and healing quality, the incidence of complications, the safety, and the bone grafting failure rate were compared. RESULTS: In TEB group, the follow-up time was 28 ± 15.48 months; nine cases were confirmed healed (3.45 ± 2.01 months), one case was cyst healing with defect, and one case had relapse. In Allo-B, 12 patients were followed up for 28.58 ± 20.44 months; seven cases were confirmed healed (6.75 ± 3.31 mo), four cases were cyst healing with defect, and one case had relapse. After operation, no statistically significant differences in bone healing and incidence of complications were observed between two groups, but the difference in bone healing time was statistically significant (P < 0.05). There was no else tumorigenesis in both groups. CONCLUSIONS: In treating simple bone cyst, Allo-B and TEB have considerable efficacy and safety; TEB is superior to Allo-B in respect of healing time; there is no rejection after TEB grafting but certain rejection after Allo-B grafting.

Functional outcome of en bloc excision and custom prosthetic replacement for giant cell tumor of the distal radius.

BACKGROUND: Giant cell tumors (GCT) of the distal radius at Campanacci grade II/III are particularly challenging to treat. Wide excision is the management of choice, but this creates a defect at the distal end of radius. We treated 11 cases of GCT of the distal radius by en bloc excision and custom prosthetic replacement. The purpose of this study was to present our experience and assess the functional outcomes of all patients treated with this surgery. MATERIALS AND METHODS: Between 2005 and 2014, we followed up 11 patients with GCT of the distal radius who were treated with en bloc excision and custom prosthetic replacement. All cases were evaluated based on clinical and radiological examinations, passive range of motion (ROM) of the wrist joint, complications, and Musculoskeletal Tumor Society (MSTS) score. RESULTS: Mean follow-up period was 55.5 months (24-83 months); mean resected length of the radius was 7.9 cm. One patient had tumor recurrence in the soft tissues after 15 months (recurrence rate 9.09 %). No patient had fracture, recurrence in the bone, metastases, or immune rejection. No complications were seen, such as loosening, rupture, or dislocation of the custom prosthesis. One patient developed superficial infection at the operative site which resolved after a course of antibiotics for 4 weeks. One patient experienced pain, which could be endured without the need for analgesics. Average ROM was 40.9° of dorsiflexion, 30.0° of volar flexion, 46.4° of supination, and 38.2° of pronation. Mean grip strength was 71 % (42-86 %). Overall revised MSTS score averaged 80.3 % (63.3-93.3 %) with one being excellent, five good, and five satisfactory. CONCLUSION: En bloc excision and custom prosthetic replacement for a Campanacci grade II/III GCT of the distal radius results in reasonable functional outcome at intermediate follow-up evaluation. Although average ROM of the ipsilateral wrist is poorer than some studies with other techniques, this method can be considered a reasonable option.

Primary dedifferentiated liposarcoma of the femur presenting with malignant fibrous histiocytoma: A case report and review of the literature.

In the current report a case of a 26-year-old male with a primary dedifferentiated liposarcoma of the femur accompanied by malignant fibrous histiocytoma is presented. The patient complained of a dull intermittent pain, for three months, along the anterolateral aspect of the right knee and was referred to Southwest Hospital (Chongqing, China) in May 2013. All of the radiographic findings, including radiography, magnetic resonance image and emission computed tomography (CT) supported the diagnosis of a primary malignant bone tumor. CT-guided biopsy results demonstrated blood clots and a small quantity of heterogeneous cells. Thus, a limb-salvage procedure, involving a wide resection and total knee endoprosthesis replacement, was performed in May 2012. The final pathological diagnosis was of a primary dedifferentiated liposarcoma of the femur and the dedifferentiated tissue was identified as malignant fibrous histiocytoma. On review of the literature, it was identified that primary intraosseous liposarcoma are a rare and malignant tumor of the skeletal system, with only a small number of cases reported in the English literature since 1980. To the best of our knowledge, a case of dedifferentiated liposarcoma has not previously been reported.

Late post-operative recurrent osteosarcoma: Three case reports with a review of the literature.

The aim of the present study was to investigate the clinical characteristics and treatment of late recurrent osteosarcoma following surgery. The cases of three patients with late recurrent osteosarcoma, who were treated at the General Hospital of Jinan Military Command, General Hospital of Nanjing Military Command and Xinan Hospital of The Third Military Medical University, were analyzed retrospectively. Furthermore, 10 cases of late recurrent osteosarcoma were retrieved from the literature. In total, eight male and five female cases were selected for the present study. The mean age at recurrence was 25.56 years (range, 13-42 years). The locations of the osteosarcomas were as follows: five cases in the distal femur, two cases in the distal tibia and acetabulum, respectively, and one case in the proximal tibia (the remaining cases were not described). The tumors were histologically classified into three cases of fibroblastic, two cases of traditional-type; two cases of mixed-type and one case each of osteoblastic-, chondroblastic- and telangiectasia-type osteosarcoma (the remaining cases were not described). The mean recurrence time following surgery was 10.02 years (range, 5.2-19.3 years). With regard to the treatment modalities, five patients accepted surgery and chemotherapy, one patient accepted surgery and radiotherapy, two patients accepted surgery alone and one patient did not complete the treatment (the remaining cases were not described). From the 12 cases that were followed-up for between 0.5 and 4.7 years (mean, 2.28 years), one case was lost to follow-up, six patients survived (up to 4.5 years) and six patients succumbed to their condition (0.6-4.7 years). The present study highlights the fact that more focus should be placed upon the long-term follow-up of patients with osteosarcoma. A follow-up is required once every six months, from five years after the diagnosis. The abnormal changes in the surgical site should also receive further attention, in addition to the pulmonary and systemic metastases. Following a diagnosis of late post-operative recurrence, surgery and post-operative chemotherapy are commonly used in clinical treatment, however, the clinical outcome of osteosarcoma requires further observation.

[Design of ABC damage variable and positioning system for acetabular fractures and 1122 cases multi-center statistic analysis].

OBJECTIVE: To design ABC damage variable and positioning system for acetabular fracture and explore the feasibility and clinical practical value of the system through the multi-center analysis of 1122 acetabular fractures. METHODS: According to acetabular three-column conception, and pelvic ring lesions damage direction caused by acetabular fracture domino effect and injury degree of proximal femur joint, it defined class A as any column acetabular fracture; class B as any two-column acetabular fracture; class C as front, dome and posterior mixture acetabular fracture. Lower case English letters a, m, p represented front, dome, posterior fracture, respectively. Acetabular damage variables: 1 was simple displaced fractures; 2 was comminuted fractures; 3 was compression fractures. Pelvic ring lesions damage variables: alpha was sacroiliac joints or sacroiliac fracture horizontal separation deflection; beta was sacroiliac joints or sacroiliac fracture vertical separation deflection; gamma was pubic symphysis separation/superior and inferior ramus of pubis fracture deflection; alpha beta gamma delta was compound floating damage. Proximal humerus joint damage variables: I was femoral head fracture; II was femoral neck fracture; II was intertrochanteric fractures of femur; IV was I to III compound fracture. The ABC damage variable positioning system for acetabular fracture was made up by the above-mentioned variables. The statistics from March 1997 to February 2010 showed 1122 cases acetabular fractures with 18 cases of double side acetabular fracture and 1140 cases of acetabular fractures. The pelvics anterior-posterior view, ilium and obturator oblique view, and 2/3D-CT materials were analyzed and researched. RESULTS: Each damage variables distribution situation in 1140 cases of acetabular fracture involved A in 237 cases (20.8%), B in 605 cases (53.1%), C in 298 cases (26.1%);front column fracture in 808 cases(70.9%), dome fracture in 507 cases (44.5%), posterior fracture in 1026 cases (90%). Acetabular variables: variabe 1 in 203 cases of simple displaced fracture (17.8%); variabe 2 in 516 cases of comminuted fracture(45.3%); variabe 3 in 421 cases of compression fracture (36.9%); 249 cases of pelvic ring lesions damage (21.8%), 75 cases femoral head fracture (6.6%); 18 cases of double side acetabular fracture and relative pelvic ring and proximal humerus joint variables (1.58%). Key part and curative effect elements of 1140 cases acetabular fracture: 507 cases of dome or posterior acetabular fracture (44.5%); 421 cases of compression fracture (36.9%); 249 cases of pelvic ring variables (21.8%); 75 cases of proximal humerus joint variables (6.6%); 486 cases of simple Aa/pl/2,Bapl/2 acetabular fracture (42.6% ). CONCLUSION: Compression fracture, especially defected compression fracture, takes important part in acetabular damage variables, and also presents that acetabular fracture with pelvic ring and proximal femoral damage variables are not rare at all. The relationship of the acetabular fracture damage variables, and its percentage shows the key points and elements in clinical treatment: weight-bearing to dome accounts for 44.5%; compression to defects account for 36.9%, pelvic ring to float accounts for 21.8%; dome fracture to double side fracture account for 6.6%. The system has significant guiding effects on clinic in terms of evaluation of injury severity, anatomic localization, difficulty index, alternative strategy, operative approach, effect of treatment,and prognosis. And the most important thing is that the system creates the comparison of damage variables in same type of fracture and the communication of homo-language and explores a new method.

Repair of large segmental bone defects using bone marrow stromal cells with demineralized bone matrix.

OBJECTIVE: The aim of the present study was to evaluate the effect of tissue-engineered constructs on repair of large segmental bone defects in goats. METHODS: Allogenic demineralized bone matrix (aDBM) was seeded with autologous marrow stromal cells (aMSC) for seven days to construct DBM-MSC grafts prior to implantation. 24 goats were randomly divided into three groups (eight in each). In each group, 3 cm diaphyseal femoral defects were created unilaterally, and subsequently filled with the DBM-MSC grafts, DBM alone and an untreated control, respectively. Radiological analysis and biomechanical evaluation were performed at 12 and 24 weeks after operation. RESULTS: Obvious increases in radiological scoring and biomechanical strength were found in the DBM-MSC group when compared to the DBM group. X-ray examination showed excellent bone healing in the DBM-MSC group, whereas only partial bone repair was seen in the DBM group, and no healing in untreated controls. Histologically, a tendency to bone regeneration and remodeling was far more obvious for the DBM-MSC group than the DBM only and untreated controls. CONCLUSION: Our results strongly suggest that transplantation of bone MSC within a DBM could have advantages for the bone repair of large segmental defects.

[Treatment of high-energy tibia plateau injury with half-ring external fixation combined with minimum internal fixation].

OBJECTIVE: To evaluate the effect of less invasive surgical treatment for high-energy tibia plateau injury with half-ring external fixation combined with minimum internal fixation. METHODS: From January, 2003 to May,2006, 16 cases of high-energy tibia plateau fracture were treated with half-ring external fixation combined with minimum internal fixation including 10 cases of type V and 6 cases of type VI according to Schatzker's classification. The average age of the patients was 42.4 years (range 25 to 50 years). RESULTS: All patients were followed for an average of 16 months (range 5 to 27 months). All the fractures healed after an average time of 3.5 months. Two patients developed infections of the pin holes. According to the criteria of Rasmussen, excellent results were achieved in 10, good results in 4 cases, moderate in 2, and poor in none. CONCLUSION: Half-ring external fixation combined with minimum internal fixation can be ideal for treatment of complex tibia plateau fracture.

[Treatment of complex bone nonunion with external skeletal fixation].

OBJECTIVES: To summarize the experience in the treatment of 112 cases of complex bone nonunion from 1982 to 1999 in our department and introduce the technique of external skeletal fixation. METHODS: The two fragment ends of all cases were fixed under pressure with half-ring sulcated external skeletal fixator. Those cases complicated by bone defect or limb shortening were operated on with epiphysiotomy to restore the length of the limb in the period of compressive fixation or after the occurrence of bone union according to the condition of complicated infection and the length of the limb shortened. RESULTS: The nonunion of the 112 cases was united eventually. The infection in 34 cases was eradicated. Bone union in cases without infection took 3 approximately 7 months (average 5.2 months) and in cases with infection took 5 approximately 11 months (average 5.5 months). The length of the limb in 11 cases with bone defect was restored in the same period of compressive external fixation and another 8 cases achieved after bone union. The length between the injured and healthy limbs was balanced. CONCLUSIONS: When external skeletal fixation is employed to treat those troublesome cases of bone nonunion, the pins for fixation are inserted in sites far from the lesions and the non-united fragment ends are exposed only in the area without scars. Consequently, there is little interference with the blood circulation and the osteogenic potency of the fragment ends. The sclerotic bone tissue is not excised, the marrow cavity is not chased to be open and the fragment ends are only moderately modified. As a result, the stability of fixation is increased and further shortening of the limb avoided. External skeletal fixation using small pins with cross penetration results in plastic fixation and promotes bone healing. Bone lengthening with epiphysiotomy can restore the balance of the limbs.

Anterior decompression of late thoracolumbar fracture dislocation with paraplegia.

The operative methods for treatment of thoracolumbar fracture-dislocations have been improved in recent years. Anterior or anterior-lateral decompression for thoracolumbar fracture-dislocations with spinal cord injury is considered as a practical and successful method by many researchers. Since 1994 using trans-pedicular partial vertebrectomy, we have treated 43 cases of late thoracolumbar fracture-dislocations with paraplegia successfully.