ObjectiveTo investigate the clinical and radiographic results of total hip arthroplasty (THA) for the treatment of hip arthrosis in patients with ankylosing spondylitis (AS). MethodsA retrospective analysis was made on the clinical data from 131 patients (195 hips) who underwent THA for AS between September 2001 and August 2011 with a follow-up period of more than 2 years. There were 100 males (152 hips) and 31 females (43 hips), aged 17-69 years (mean, 33.7 years). The average interval between AS onset and THA was 13.7 years (range, 1-50 years). The left hips were involved in 30 cases, the right hips in 37 cases, and bilateral hips in 64 cases. Preoperative Harris hip score was 18.0±13.7; the sum passive range of motion was (36.2±51.2)°; and the hip passive-flexion arc was (23.4±32.6)°. In 175 hips with passive flexion of less than 90°, 134 hips had flexion contracture. Based on preoperative X-ray films and CT scan, 195 hips were divided into the non-ankylosed subgroup (86 hips), fibrous ankylosed subgroup (43 hips), and bony ankylosed subgroup (66 hips); and the recovery of hip function was compared between subgroups after operation. ResultsIntraoperative complications included linear fractures of femoral calcar in 4 hips, fractures of acetabular posterior column in 1 hip, femoral shaft fractures in 2 hips, and iatrogenic sciatic nerve injury in 3 hips; postoperative complications included anterior dislocation in 2 hips. The average follow-up period was 51.3 months (range, 24-143 months). Bone healing was observed at 3-6 months after operation (mean, 3.9 months). At last follow-up, the average Harris hip score increased to 86.4±14.1, the sum passive range of motion increased to (202.0±28.0)°, and the hip passive-flexion arc increased to (93.2±15.3)°, all showing significant differences when compared with preoperative ones (P<0.05). Based on a four-class scale for subjective satisfaction, the patients were very satisfied, satisfied, and not satisfied with the results of THA in 100, 80, and 15 hips respectively. X-ray films showed radiolucent line (<2 mm) in 5 acetabular components (zones I and II); heterotopic ossification was observed in 49 hips after THA. There was no significant difference in the Harris hip score among 3 subgroups after THA at last follow-up (P>0.05). At last follow-up, the degree of passive flexion in the fibrous ankylosed subgroup and bony ankylosed subgroup was significantly lower than that in the non-ankylosed subgroup (P<0.05), and the sum passive range of motion in the fibrous ankylosed subgroup was significantly lower than that in the non-ankylosed subgroup (P<0.05), but no significant difference was found in the other variables among the 3 sub groups (P>0.05). ConclusionFor severe hip arthrosis in patients with AS, the overall outcomes after THA are ideal with a good midterm prosthetic survivorship, a low complication rate, and a high satisfaction of patients. However the hip function after THA is still less satisfactory.
ObjectiveTo review the research progress of endogenous repair strategy (ERS) in intervertebral disc (IVD).MethodsThe domestic and foreign literature related to ERS in IVD in recent years was reviewed, and its characteristics, status, and prospect in the future were summarized.ResultsThe key of ERS in IVD is to improve the vitality of stem/progenitor cells in IVD or promote its migration from stem cell Niche to the tissue that need to repair. These stem/progenitor cells in IVD are derived from nucleus pulposus, annulus fibrosus, and cartilaginous endplate, showing similar biological characteristics to mesenchymal stem cells including the expression of the specific stem/progenitor cell surface markers and gene, and also the capacity of multiple differentiations potential. However, the development, senescence, and degeneration of IVD have consumed these stem/progenitor cells, and the harsh internal microenvironment further impair their biological characteristics, which leads to the failure of endogenous repair in IVD. At present, relevant research mainly focuses on improving the biological characteristics of endogenous stem/progenitor cells, directly supplementing endogenous stem/progenitor cells, biomaterials and small molecule compounds to stimulate the endogenous repair in IVD, so as to improve the effect of endogenous repair.ConclusionAt present, ERS has gotten some achievements in the treatment of IVD degeneration, but its related studies are still in the pre-clinical stage. So further studies regarding ERS should be carried out in the future, especially in vivo experiments and clinical transformation.
Objective To investigate the changing tendency of mitral valve coaptation area and coaptation index of moderate mitral regurgitation （MR） in a dog experiment，and provide evidence for predicting long-term surgical results. Methods Real-time three-dimensional transesophogeal echocardiography （RT-3D-TEE） images were obtained in 15 dogs via Philips IE33 echocardiography system，and animal experiment model was established. RT-3D-TEE images were taken by gradually narrowing the ascending aorta and increasing left ventricular pressure till moderate MR. Original data were analyzed using Philips Qlab 7.0 three-dimensional quantification software，and mitral valve coaptation area and coaptation index were calculated. Specimen coaptation index of the mitral leaflets was calculated after the animal experiment. Cutoff values of coaptation index and left ventricular pressure were calculated by receiver operating characteristic （ROC） curve. Results There was statistical difference in coaptation area （198±50）mm2 vs. （123±36）mm2，P＜0.05） and coaptationindex （0.25±0.06 vs. 0.13±0.03，P＜0.05） between non-MR state and MR status of the 15 dogs. The area under the ROC curve of coaptation index and moderate MR was 0.879±0.019 with 95% CI 0.843 to 0.916，and the cutoff value was 0.213（P＜0.05）. The area under the ROC curve of left ventricular pressure and moderate MR was 0.882±0.021 swith 95% CI 0.840 to 0.923，and the cutoff value was 225 （P＜0.05）. There was no statistical difference between specimen mitral valve area and early-diastolic mitral leaflet area，specimen coaptation area and coaptation area，specimen coaptation index and coaptation index （P＞0.05）. Early-diastolic mitral leaflet area was significantly correlated with specimen mitral valve area （r=0.937，P＜0.05）. Coaptation area was significantly correlated with specimen coaptation area （r=0.917，P＜0.05）. Coaptation index was significantly correlated with specimen coaptation index （r=0.946，P＜0.05）. The correlation of coaptation index and specimen coaptation index was higher than those of coaptation area and specimen coaptation area，and earlydiastolic mitral leaflet area and specimen mitral valve area. Conclusions Both coaptation area and coaptation index significantly decrease in MR status. Coaptation index can more precisely reflect MR degree，and provide reference for prognosis of mitral valve repair. RT-3D TEE can accurately measure mitral valve coaptation area and coaptation index.
In this paper, the differences between air probe and filled probe for measuring high-frequency dielectric properties of biological tissues are investigated based on the equivalent circuit model to provide a reference for the methodology of high-frequency measurement of biological tissue dielectric properties. Two types of probes were used to measure different concentrations of NaCl solution in the frequency band of 100 MHz–2 GHz. The results showed that the accuracy and reliability of the calculated results of the air probe were lower than that of the filled probe, especially the dielectric coefficient of the measured material, and the higher the concentration of NaCl solution, the higher the error. By laminating the probe terminal, liquid intrusion could be prevented, to a certain extent, to improve the accuracy of measurement. However, as the frequency decreased, the influence of the film on the measurement increased and the measurement accuracy decreased. The results of the study show that the air probe, despite its simple dimensional design and easy calibration, differs from the conventional equivalent circuit model in actual measurements, and the model needs to be re-corrected for actual use. The filled probe matches the equivalent circuit model better, and therefore has better measurement accuracy and reliability.
In this paper, a new probe is proposed for the in vivo dielectric measurement of anisotropic tissue in radio frequency band, which could accomplish the dielectric measurement in perpendicular directions by one operation. The simulative studies are performed in the frequency range from 1–1 000 MHz in order to investigate the influence of probe dimension on the energy coupling and sensitivity of measurement. The suitable probe is designed and validated for the actual measurement in this frequency band. According to the simulation results, the energy coupling of the probe could be kept below –12 dB in the frequency range from 200–400 MHz with high sensitivity of measurement for the dielectric properties of anisotropic tissue. That indicates the new type of probe has the potential to achieve the dielectric measurement of anisotropic tissue in radio frequency band and could avoid the measurement error by multi-operations in the conventional method. This new type of probe could provide a new method for the in vivo dielectric measurement of anisotropic tissue in radio frequency band.
Magnetic induction method aims at the noninvasive detection of liver iron overload by measuring the hepatic magnetic susceptibility. To solve the difficulty that eddy current effects interfere with the measurement of magnetic susceptibility, we proposed an improved coil system based on the static field magnetization principle in this study. We used a direct current excitation to eliminate the eddy current effect, and a rotary receiver coil to get the induced voltage. The magnetic field for a cylindrical object due to the magnetization effect was calculated and the relative change of maximum induced voltage was derived. The correlation between magnetic susceptibility of object and maximum magnetic flux, maximum induced voltage and relative change of maximum induced voltage of the receiver coil were obtained by simulation experiments, and the results were compared with those of the theory calculation. The contrast shows that the simulation results fit the theory results well, which proves our method can eliminate the eddy current effect effectively.
ObjectiveTo evaluate mid-term results of total hip arthroplasty (THA) for treatment of osteoarthritis secondary to hip sepsis. MethodsBetween February 2003 and January 2009, 62 patients (62 hips) with osteoarthritis secondary to hip sepsis underwent THA. There were 32 males and 30 females with an average age of 39.9 years (range, 18-67 years). The original infection included pyogenic arthritis in 40 hips and tuberculosis in 22 hips. After infection, 35 patients underwent non-operative treatment, and 27 patients received operative management. The average time interval between initial infection and THA was 28.7 years (range, 12-53 years). The preoperative Harris hip score was 24.6±9.2. The Trendelenburg sign was positive in all hips. Leg discrepancy was observed in 25 cases, and the mean discrepancy of bilateral lower extremities was 3.8 cm (range, 2.6-6.5 cm) preoperatively. All hips had no evidence of active hip sepsis. ResultsAll patients were followed up 72 months on average (range, 54-115 months). Intraoperative complications included sciatic nerve injury (2 cases) and femoral shaft fractures (2 cases); postoperative complications included hip anterior dislocation (1 case) and periprosthetic infection (1 case). At last follow-up, 1 hip, 5 hips, 18 hips, and 38 hips were found to have severe pain, moderate pain, slight pain, and no pain respectively. Claudication occurred in 30 patients (mild in 19, moderate in 8, and severe in 3). The Trendelenburg sign was positive in 18 hips. After THA, only 5 patients had a leg length discrepancy of 2.9 cm on average (range, 2.6-3.5 cm). The Harris score was significantly increased to 82.3±11.4 at last follow-up when compared with preoperative one (t=-31.241, P=0.000). The results of subjective satisfaction were very satisfactory in 43 cases, satisfactory in 12 cases, unsatisfactory in 4 cases, and unsatisfactory at all in 3 cases. No sign of aseptic loosening of prosthesis was found during follow-up period. Roentgenographic results showed no radiolucent line or osteolysis in the other patients except 2 patients having local radiolucent. After THA, 12 hips had heterotopic ossification. ConclusionThe mid-term clinical and radiographic results of THA for treatment of osteoarthritis secondary to hip sepsis are good, with the advantages of high satisfactory rate, good function recovery, and low complication incidence.
Objective To assess the midterm follow-up outcomes of total hip arthroplasty (THA) for the treatment of patients with juvenile-onset ankylosing spondylitis (JAS). Methods The clinical data of 81 patients (127 hips) with JAS (age≤16 years, JAS group) and 267 patients (391 hips) with adult onset ankylosing spondylitis (AAS) (age>16 years, AAS group) between January 2004 and March 2018 were retrospectively analysed. The baseline demographics, clinical, radiographic, and laboratory parameters were collected. Before operation and at last follow-up, the overall disease activity [Bath ankylosing spondylitis disease activity index (BASDAI)] and function status [Bath ankylosing spondylitis functional index (BASFI)], hip subjective score [Harris hip score (HHS)] and objective score [12-item short form health survey (SF-12), including physical component score (PCS) and mental component score (MCS)], and patient satisfaction for THA were reviewed. The major orthopedic complications, including periprosthetic infection, dislocation, periprosthetic fractures, and poor incision healing, were also recorded during the follow-up period. Results The comparison of preoperative baseline parameters showed that the body mass, body mass index, age of onset, age of surgery, disease duration, and the proportion of combined smoking history in the JAS group were significantly lower than those in the AAS group (P<0.05), the proportion of bilateral surgeries, proportion of uveitis, proportion of combined family history, C-reactive protein, albumin, and preoperative BASFI were significantly higher than those in the AAS group (P<0.05). Both groups were followed up. The follow-up time in the JAS group was 29-199 months, with an average of 113 months; in the AAS group was 35-199 months, with an average of 98 months. Incisions in both groups healed by first intention. During the follow-up period, there were 1 case of periprosthetic fracture, 1 case of dislocation, and 1 case of ceramic fragmentation in the JAS group, 1 case of periprosthetic infection and 6 cases of periprosthetic fracture in the AAS group. There was no significant difference in the incidence of complications between the two groups (P>0.05). At last follow-up, the BASDAI, BASFI, SF-12 MCS, SF-12 PCS, and HHS score of the two groups were significantly improved when compared with those before operation (P<0.05); but there was no significan difference in the difference of the above parameters before and after operation and the patient satisfaction between the two groups (P>0.05). Conclusion The midterm follow-up outcomes of THA for the treatment of JAS patients were reliable. A low age at disease onset did not exert a significant negative effect on THA reconstruction for the treatment of ankylosing spondylitis.
Objective To summarize the probability of pulmonary embolism （PE） induced by lower extremity deep venous thrombosis （DVT） and investigate the role of vena cava filter （VCF） in preventing from PE. Methods The clinical data of 1 058 patients with lower extremity DVT from January 2005 to January 2012 were analyzed retrospectively. Results The PE rate was 3.21% （34/1 058） and the death rate was 1.42% （15/1 058） in 1 058 patients with lower extremity DVT. The VCF was implanted in 171 of 1 058 patients. The VCFs of 151 patients were implanted from femoral vein， 20 patients were implanted from jugular vein. The PE rates were 3.61% （32/887） and 1.17% （2/171） and the death rates were 1.69% （15/887） and 0 （0/171） in patients without VCF and with VCF， respectively. Both of them occurred in the first ten days. PE could keep as long as 35 d. The PE rate and death rate in the patients without VCF were significantly higher than those in the patients with VCF （P＜0.01）. The PE rates and death rates in both lower extremities DVT were higher than those in patients with the right and left ones （P＜0.05）， which in the right lower extremity were higher than those in the left one （P＜0.05）. The PE rate and death rate in the patients with lower extremity DVT combined with vena cava thrombosis were significantly higher than those in the patients with central type （P＜0.05）， which in the central type were significantly higher than those in the peripheral type （P＜0.05）， there were no significant differences between peripheral type and mixed pattern. The follow-up time was from 1 month to 7 years with （39±19） months， the patency rate of VCF was 98.7%. There were no filter migration， declination， and failure of expansion. Conclusions VCF can prevent from PE effectively， but the indications must be controlled.
In response to the problem that the traditional lower limb rehabilitation scale assessment method is time-consuming and difficult to use in exoskeleton rehabilitation training, this paper proposes a quantitative assessment method for lower limb walking ability based on lower limb exoskeleton robot training with multimodal synergistic information fusion. The method significantly improves the efficiency and reliability of the rehabilitation assessment process by introducing quantitative synergistic indicators fusing electrophysiological and kinematic level information. First, electromyographic and kinematic data of the lower extremity were collected from subjects trained to walk wearing an exoskeleton. Then, based on muscle synergy theory, a synergistic quantification algorithm was used to construct synergistic index features of electromyography and kinematics. Finally, the electrophysiological and kinematic level information was fused to build a modal feature fusion model and output the lower limb motor function score. The experimental results showed that the correlation coefficients of the constructed synergistic features of electromyography and kinematics with the clinical scale were 0.799 and 0.825, respectively. The results of the fused synergistic features in the K-nearest neighbor (KNN) model yielded higher correlation coefficients (r = 0.921, P < 0.01). This method can modify the rehabilitation training mode of the exoskeleton robot according to the assessment results, which provides a basis for the synchronized assessment-training mode of “human in the loop” and provides a potential method for remote rehabilitation training and assessment of the lower extremity.