[Effect of changes in posterior tibial slope on the mid-term clinical outcomes of Oxford unicompartmental knee arthroplasty]

Objective: To investigate the impact of changes in the posterior tibial slope (PTS) in Oxford unicompartmental knee arthroplasty (OUKA) on the mid-term clinical outcomes of postoperative patients. Methods: This study was a follow-up study. The data of 135 patients (150 knees) who underwent OUKA at the China-Japan Friendship Hospital from January 2012 to January 2013 were analyzed retrospectively. The patients were followed-up for at least ten years. According to the changes in PTS of the medial tibial plateau before and after surgery, patients were divided into three groups: group A (PTS decreased by more than 5°), group B (PTS changed by 5° or less), and group C (PTS increased by more than 5°). The Knee Society Clinical Score (KSS-C), Knee Society Functional Score (KSS-F), Oxford Knee Score (OKS), Forgotten Joint Score (FJS), and knee range of motion (ROM) among the three groups were compared at the last follow-up. Results: Prior to the final follow-up assessment, six patients expired, and an additional nine patients were lost to follow-up. A total of 120 patients (135 knees) were enrolled in this study (30 males and 90 females). The mean age was (66.29±8.62) years, and the follow-up time was (10.54±0.72) years. Group A consisted of 32 patients (34 knees), group B comprised 77 patients (90 knees), and group C included 11 patients (11 knees). One knee in group A suffered prosthesis loosening, and two knees in group C experienced postoperative bearing dislocation, one knee encountered bearing fragmentation. The incidence of postoperative complications differed significantly among the three groups (P<0.05). The preoperative OKS was (33.91±6.59) points, KSS-F was (43.46±8.99) points, KSS-C was (41.05±5.70) points and ROM was 115.23°±13.53°; after the surgery, they changed to (18.82±7.01) points, (81.51±7.34) points, (82.64±7.94) points, and 119.07°±8.62°, respectively, and all the differences were statistically significant (all P<0.001). In terms of postoperative outcomes, group A had an OKS of (21.44±8.46) points and a FJS of (63.83±11.40) points, group B had an OKS of (17.07±5.81) points and a FJS of (70.49±12.45) points, group C had an OKS of (25.09±5.07) points and a FJS score of (59.48±10.09) points; the differences among the three groups were all statistically significant (all P<0.05), but there were no significant differences in the postoperative KSS scores and ROM among the three groups (all P>0.05). Conclusions: After OUKA, better mid-term clinical outcomes are achieved when ΔPTS is<5°. Although the recommended central value for PTS in OUKA is 7° according to Oxford, it should be individualized, and it is recommended to consider the preoperative angle, with a change of less than 5° before and after surgery.

[Genetic expression differences of 11 beta-hydroxysteroid dehydrogenase in the bone microvascular endothelial cells derived from different regions of the human femoral head]

Objective: To investigate the expression levels and activation differences of 11beta-hydroxysteroid dehydrogenase (11beta-HSD) gene in bone microvascular endothelial cells (BMECs) in different regions of human femoral head. Methods: Tissue specimens of femoral heads were obtained from hip arthroplasty carried out in China-Japan Friendship Hospital from January 2017 to June 2018. And the BMECs we isolated, purified, identified and cultured from different regions of the human femoral head: in the subchondral and cancellous bone regions. The BMECs from the two regions were intervened by hydrocortisone with a series of low concentration gradients (0, 0.03, 0.06, 0.10 mg/ml) respectively. The cell phenotype and functional status of BMECs and cell migration were detected by scratch experiments, and the angiogenesis in different regions of the femoral head was observed. The mRNA and protein expression of 11beta-HSD1, 11beta-HSD2 in BMECs were detected by real-time fluorescence quantitative polymerase chain reaction (RT-PCR) and Western-blot method, respectively. Results: With the increase of the concentration of hydrocortisone, the 11beta-HSD1 mRNA and protein expression of BMECs in the subchondral and cancellous bone regions of the femoral head increased significantly, and the 11beta-HSD1 mRNA and protein expression of BMECs in the subchondral bone region was significantly lower than those in cancellous bone region (all P<0.05). The 11beta-HSD2 mRNA and protein expression of BMECs in the cancellous bone region showed a slow decrease first and then increased slightly at 0.10 mg/ml, while the expression in the subchondral bone region was the opposite. The 11beta-HSD2 mRNA and protein expression of BMECs in subchondral bone region was slightly higher than those in cancellous bone region (all P<0.05), but there was no significant statistical difference between the two regions at 0.10 mg/ml (0.123±0.018 vs 0.126±0.021, 0.577±0.231 vs 0.609±0.174, t=1.380, 0.409, both P>0.05). At different times of the 0.06 mg/ml hydrocortisone intervention, there was no significant differences in scratch closure rate, the number of BMECs lumen, the number of buds and the length of tubule branches in different regions of the femoral head (all P>0.05). Conclusion: The 11beta-HSD expression of BMECs in different regions of human femoral head is significantly different. The 11beta-HSD1 is high-expressed, but 11beta-HSD2 is low-expressed in BMECs of the cancellous bone region, and those are opposite in the subchondral bone region, which helps to explain the pathological characteristics and pathogenesis of hormonal osteonecrosis.

[Individual difference of coronal bowing of femur and its influence on the lower limbs alignment after the total knee arthroplasty]

Objective: To disclose the correlation between the femur bowing angle(FBA) and vulgas correction angle(VCA), anlysys its influence on the total knee arthroplasty and the lower limbs alignment. Methods: From Janurary 2013 to December 2015, 699 patients who had received total knee arthroplasty(TKA)were collected in the Department of Joint Surgery, China-Japan Friendship. The FBA, VCA, offset of the proximal femur, the lengh of the femur, the neck shaft angle of the femur of the eligible cases from the long leg X-ray were measured.All the data were analysed for the following steps: the FBA's mean value and characteristics of distributation of all the cases; the VCA's mean value and characteristics of distributation of all the cases; correlations between the VCA and the other parameters; divide all the cases into four groups based on the value of FBA : group A(FBA<-3°, 29), group B(-3°≤FBA≤0°, 255), group C(0°<FBA≤3°, 480), group D(FBA>3°, 236)and then plan to cut the distal femur with 5° and 6°, respectively. The percent of ideal alignmental outcome's percentage of every group were compared. Results: The mean Value of the FBA is -7.1--12.1(1.4±2.4)°; the mean Value of the VCA is 2.5--11.9(6.5±1.3)°. The correlation index between VCA and FBA, the neck shaft angle of the femur , offset of the hip joint, the lengh of the femur is 0.72, -0.26, 0.45 and -0.08, perspectively. The theoretical ideal alignment percentage of the 5 degree-valgus-bone cut and 6 degree-valgus-bone cut in every group is group A: 89.7% and 66.5%; group B: 93.7% and 95.7%; group C: 71.9% and 94.6%; group D: 21.2% and 50.8%, respectively. Conclusion: The cases whose femur bowing angles are outliers are common in daily medical practice, so the vulgas correction angles need be ajusted for its significant correlation with FBA. 5 degree-valgus-bone cut or 6 degree-valgus-bone cut could not get the ideal alignment some times.

[Clinical outcomes of single-level lumbar spondylolisthesis by minimally invasive transforaminal lumbar interbody fusion with bilateral tubular channels]

Objective: To evaluate the clinical effectiveness of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) for single-level lumbar spondylolisthesis treatment with bilateral Spotlight tubular channels. Methods: A total of 21 patients with lumbar spondylolisthesis whom underwent MIS-TLIF via bilateral Spotlight tubular channels were retrospectively analyzed from October 2014 to November 2015. The 21 patients included 11 males and 10 females ranged from 35 to 82 years (average aged 60.7 years). In term of spondylolisthesis category, there were 18 cases of degenerative spondylolisthesis and 3 cases of isthmic spondylolisthesis. With respect to spondylolisthesis degree, 17 cases were grade Ⅰ° and 4 cases were grade Ⅱ°. Besides, 17 cases at L(4-5) and 4 cases at L(5)-S(1)were categorized by spondylolisthesis levels. Operation duration, blood loss, postoperative drainage and intraoperative exposure time were recorded, functional improvement was defined as an improvement in the Oswestry Disability Index (ODI), Visual Analog Scale (VAS) was also employed at pre and post-operation (3 months and the last follow-up), to evaluate low back and leg pain. Furthermore, to evaluate the recovery of the intervertebral foramen and of lumbar sagittal curvature, average height of intervertebral space, Cobb angles of lumbar vertebrae and operative segments, spondylolisthesis index were measured. At the last follow-up, intervertebral fusion was assessed using Siepe evaluation criteria and the clinical outcome was assessed using the MacNab scale. Radiographic and functional outcomes were compared pre- and post-operation using the paired T test to determine the effectiveness of MIS-TLIF. Statistical significance was defined as P<0.05. Results: All patients underwent a successful MIS-TLIF surgery. The operation time (235.2±30.2) mins, intraoperative blood loss (238.1±130.3) ml, postoperative drainage (95.7±57.1) ml and intraoperative radiation exposure (47.1±8.8) were recorded. Different significance between 3 months post-operative follow-up and pre-operation was exhibited (P<0.01) in respects of lumbar VAS (t=11.1, P<0.01) and leg VAS (t=17.8, P<0.01). Moreover, final follow-up compared with pre-operation, and final follow-up compared with 3 months post-operative follow-up, VAS scores were also statistical difference (P<0.01). At the final follow-up, there were significant differences compared with pre-operation in ODI scores (t=30.1, P<0.01). Comparison between 3 months post-operative follow-up and pre-operation, statistical distinctions were demonstrated (P<0.05) in terms of mean height of intervertebral space (t=-10.9, P<0.01), the Cobb angles of lumbar vertebrae (t=-2.4, P<0.05), operative segments Cobb angles (t=-5.2, P<0.01) and Lumbar spondylolisthesis incidence (t=17.1, P<0.01). In addition, there was statistical difference between final follow-up and pre-operation (P<0.05) as well. For instance, mean height of intervertebral space (t=-10.5, P<0.01), the Cobb angles of lumbar vertebrae (t=-2.7, P<0.05), operative segments Cobb angles (t=-4.2, P<0.01) and Lumbar spondylolisthesis incidence (t=18.6, P<0.01) were involved. All spondylolisthesis vertebrae were restored completely. Lastly, at the last follow-up, 12 cases of grade 1 and 7 cases of grade 2 fusion were present as determined by the Siepe evaluation criteria. McNab scale assessment classified 17 patients having excellent clinical outcome, 3 patients in good and 1 patient having a better clinical outcome. Conclusion: MIS-TLIF with bilateral Spotlight tubular channels is a safe and effective approach for single segment lumbar spondylolisthesis.

[Clinical effect of compound internal fixations in treating extreme distal radial fractures]

Objective: To investigate the clinical character and treating strategy of extreme distal radial fractures. Methods: From June 2012 to May 2014, 12 patients who suffered from extreme distal radial fractures were treated in Department of Orthopedics, Tongji Hospital, Tongji University. According to AO/OTA classification, there were 4 cases of type 23B1, 3 cases of 23B2, 3 cases of 23C1 and 2 cases of 23C3.When classified by morphological features, there were 4 of simple styloid process fracture, 3 of simple extreme distal radial fracture without articular surface involved, 3 of styloid process fracture combined with distal radial articular fracture, and 2 of articular surface splintered or collapse fracture. According to the fracture features that radiographic exams showed, different surgical paths and fixation methods were chosen in order to protect soft tissues to the best advantage. To those patients with simple styloid process fracture, screw alone, Kirschner-wire or styloid plate were used for fixation. To the other types of fracture, open reduction and compound internal fixation with low-notch volar plate, dorsal or volar mini-plate, screw or Kirschner-wire was applied to ensure the stability of fixation, and maximally protect soft tissues like tendons, ligaments and neurovascular bundles, counting on the "stuffing-squeezing" effects after reduction or reconstruction of the articular surface. Situation of the wound and soft tissue were mainly checked in the first 2 weeks, and in the 3rd month post-operatively, fracture reduction and internal fixation were evaluated by radiographic methods like X-ray and CT scan. When 12 months post-operatively, not only radiographic follow-up such as fracture reduction, internal fixation and osteoarthritis were taken, but also some other evaluation, such as pain of wrist, rotation range of forearm, grip strength, and function of wrist according to DASH scores. Results: All of the 12 cases were followed up for at least 1 year. The wound healed well in all cases 2 weeks post-operatively, and no soft tissue infections, necrosis or neurovascular complications occurred. All fractures healed and no loss of reduction occurred 3 months post-operatively. Internal fixations were at good condition except in 2 cases, whose Kirschner-wire had been removed 2.5 and 2.8 months after the operation due to loosening and partly backing out on dorsal side. When followed up at 12 months post-operatively, one from these 2 patients suffered from a mild pain of wrist, and grip strength together with the function of the affected wrist dramatic declined when compared to the unaffected side. With the help of radiograph, local collapse on the articular surface was found, which meant to be traumatic arthritis. There were no pain in the rest 11 cases, and flexion-extension range of the wrist, rotation range of forearm and grip strength of the affected side recovered to over 80% of the unaffected side, with a DASH score was from 7 to 15 points(average 11.9 points)below 15 points. Conclusions: Traditional volar plates can not be used for extreme distal radial fractures. It may be an effective way to treat extreme distal radial fractures with compound internal fixation on the basis of morphological feature of fractures and the situation of soft tissue because of vivid of the fixation, reducing damage of soft tissue and early functional training.

The correlation between vertebral wedge-shaped changes in X-ray imaging at supine and standing positions and the efficacy of operative treatment of thoracolumbar spinal fracture in the elderly

STUDY DESIGN

By analyzing a large number of surgical patients, we identified the roles of wedge-shaped changes in related surgeries.

OBJECTIVES

To illustrate the relevance of vertebral wedge-shaped changes in X-ray imaging at supine and standing positions in patients with percutaneous kyphoplasty as well as the postoperative effect.

SETTING

All patient data were collected from a hospital in China.

METHODS

Between June 2006 and May 2010, 77 surgical patients (9 men and 68 women) with wedge-shaped compression fractures were retrospectively analyzed. Patients were divided into group A (ΔWR2.5%) and group B (ΔWR<2.5%) according to the dynamic changes in the percentage of vertebral body wedge-shaped variable ratio (WR) at supine and standing positions. The intensity of back pain in different positions pre- and postoperatively was evaluated with a visual analog pain scale (VAS).

RESULTS

The WRs in both standing and supine positions were significantly reduced by kyphoplasty in both groups A and B. In agreement with the improvement in WRs, the VAS was significantly decreased in three positions for patients in group A and in turning over and standing position for patients in group B. With respect to ΔWR changes, group B revealed significantly lower values compared with group A preoperatively (P<0.001), but there was no significant difference between groups A and B postoperatively and at 1-month follow-up (P=0.179 and P=0.558, respectively).

CONCLUSIONS

Improvement in symptoms after kyphoplasty is better in patients with wedge-shaped changes in supine and standing positions, and the efficacy of height restoration of the spine would be better in unstable vertebrae by balloon dilatation.

A secure communication scheme based on the phase synchronization of chaotic systems

Phase synchronization of chaotic systems with both weak and strong couplings has recently been investigated extensively. Similar to complete synchronization, this type of synchronization can also be applied in secure communications. We develop a digital secure communication scheme that utilizes the instantaneous phase as the signal transmitted from the drive to the response subsystems. Simulation results show that the scheme is difficult to be broken by some traditional attacks. Moreover, it operates with a weak positive conditional Lyapunov exponent in the response subsystem.

[Substitution of BMEC-CM for hematopoietic stimulators in the culture of CFU-GM and HPP-CFC]

The effects of > 10 kD component of serum-free conditioned medium from murine bone marrow-derived endothelial cell line on the formation of CFU-GM and HPP-CFC were investigated. We found that > 10 kD component alone could stimulate CFU-GM colony formation in dose-dependent. Above- 10 kD component supplemented with GM-CSF not only resulted in significant increase of CFU-GM as compared with > 10 kD or GM-CSF alone, but also could stimulate HPP-CFC formation. The effect of > 10 kD component on the formation of HPP-CFC was also in dose-dependent. The component above- 10 kD combined with IL-3, IL-6, EPO, SCF or GM-CSF further enhanced HPP-CFC colony formation. The results suggest that > 10 kD component may be used as the substitutes of hematopoietic growth factors to stimulate the formation of CFU-GM and HPP-CFC.

Optical Omega network: a compact implementation technique

We propose a technique for the compact implementation of an optical Omega network. This technique utilizes the concept that both the perfect-shuffle interconnection and the switching stages can be realized by the same procedures, i.e., duplicate, shift, superimpose, and mask. As a result, a single set of optics is sufficient to realize the whole Omega network in a time-multiplexed recursive manner. Optical setups were designed and a proof-of-principle experiment was performed.

Space-variant optical logic operations based on operation-dependent encoding method

We propose performing space-variant optical logic operations in a space-invariant optical system by selectively assigning encoding states that are operation dependent. With this method, encoders using liquid-crystal cells and liquid-crystal light valves to perform space-variant encoding for all 16 Boolean functions are designed. Multiple-instruction-multiple-data processing can then be realized in optical logic systems.

High-efficiency cosine-approximated binary Gabor zone plate

A cosine-approximated binary Gabor zone plate is proposed. The zone plate is fabricated by standard photographic techniques. It was evaluated by simulation and by experiment to match the focusing behavior of an ideal Gabor zone plate, but it has a focusing efficiency at least 23% higher than that of a binary Gabor zone plate. Duplication of an alphabetic character to form a 4 × 4 array of images with little astigmatism by the proposed zone-plate array is demonstrated.

Recording complex holograms on photoresist by using an ion-implantation method

Photoresists have traditionally been used as a holographic recording medium for phase holograms. We demonstrate the recording of a binary amplitude hologram on photoresist by using an ion-implantation method. This amplitude recording property is based on the fact that the optical transmittance of photoresist can be changed by a high-dose ion implantation. A novel complex-hologram recording method is proposed in which the phase is represented by photoresist thickness and the amplitude is encoded on its optical transmittance.

Design of digital-optical processors by using both intensity and polarization-encoding schemes

Here we propose two encoding schemes that utilize both light intensity and polarization to code input data in digital-optical computing. This approach results in a more efficient information carrying and processing technique when compared with the traditional intensity-only or polarization-only encoding schemes. Optical logic units that are based on the proposed encoding schemes are designed. A recursive parallel adder and a carry look-ahead adder that use these logic units as building blocks are also described.