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Tomographic synthetic aperture radar (TomoSAR) technology has demonstrated significant practical value in forest parameter extraction, accumulating a wealth of airborne data and research results over the years. This paper addresses the problem of TomoSAR underlying topography inversion in forested areas, where the complex vertical structure of forests contributes to diverse scattering mechanisms, making it difficult to determine the exact number of scatterers within each unit. To tackle this issue, we propose a TomoSAR underlying topography inversion method that combines density clustering with the multiple signal classification (MUSIC) technique. The proposed algorithm achieves superior estimation for the positions of unknown scatterers by utilizing eigenvalue density clustering to distinguish the signal and noise subspaces. A series of simulated experiments were conducted to showcase the robustness of the proposed algorithm in estimating scatterer phase centres under challenging conditions such as low signal-to-noise ratio and limited snapshots. Moreover, the practicality of the proposed algorithm in accurately reconstructing the underlying topography is validated by experimental results of real data obtained from the BioSAR 2008 campaign dataset. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to evaluate and compare the clinical and radiological outcomes of three different patellar fixation techniques on medial patellofemoral ligament reconstruction (MPFLR) in the treatment of patellar dislocation (PD). Methods: Between 2015 and 2020, 130 patients with recurrent PD who underwent surgical reconstruction were eligible for this retrospective study: 48 patients were treated with the semi‐tunnel bone bridge fixation technique (Group A), 42 patients were treated with the suture anchor fixation technique (Group B) and 40 patients were treated with the transpatellar tunnel fixation technique (Group C). Clinical outcomes included functional outcomes (Kujala, Lysholm and International Knee Documentation Committee scores), activity levels (Tegner activity score and return to sports), physical examinations, patellar re‐dislocation rate and complications. Radiological outcomes included patellar congruence angle, patellar tilt angle, lateral patellar translation and lateral patellar angle. Results: All clinical and radiological outcomes improved significantly in all groups, without any significant difference among these three groups. At the final follow‐up, no re‐dislocation occurred, and all groups achieved a successful return to sports. However, the semi‐tunnel bone bridge and suture anchor fixation techniques showed statistically higher Tegner activity scores (p = 0.004) and shorter time from surgery to return to sports (p = 0.007) than the transpatellar tunnel fixation technique. Conclusion: The three MPFLR patellar fixation techniques achieved favourable and comparable clinical and radiological outcomes in the treatment of PD. Compared with the transpatellar tunnel fixation technique, the semi‐tunnel bone bridge and suture anchor fixation techniques may be more effective with higher activity levels. Level of Evidence: Level III. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to evaluate the clinical effect of derotational femoral osteotomy combined with medial patellofemoral ligament reconstruction for patellar dislocation and the effect of the distribution of femoral torsion at different segments on postoperative function. Methods: Forty‐two patients with patellar dislocation who underwent derotational femoral osteotomy from 2017 to 2021 were retrospectively analysed. All patients received computed tomography scans from the hip to the knee to evaluate correction of the femoral anteversion (FA) angle, patellar tilt angle (PTA) and congruence angle (CA) after derotational femoral osteotomy. Subjective scores, such as the Kujala, Lysholm, International Knee Documentation Committee (IKDC), Tegner and visual analog scale (VAS) scores, were used to evaluate knee function before and after the operation. Patients with supracondylar torsion > distal torsion were categorized into the supracondylar torsion group and patients with distal torsion > supracondylar torsion were categorized into the distal torsion group. Subgroup analyses were performed. Results: No presentation of redislocation occurred in these patients at the minimum 2‐year follow‐up visit. The mean preoperative FA angle in the supracondylar torsion group was 30.2° ± 4.2°, and the mean postoperative FA angle was 14.5° ± 2.5° (p < 0.001). The mean preoperative FA angle was 26.7° ± 1.4° and the mean postoperative FA angle was 14.1° ± 1.4° in the distal torsion group. In addition, postoperative PTA and CA were significantly corrected in both groups (p < 0.001). The postoperative Kujala, Lysholm, IKDC, Tegner and VAS scores were significantly improved in both groups (p < 0.001). Subgroup analyses showed a higher preoperative FA in the supracondylar torsion group and a higher occurrence of high‐grade trochlear dysplasia in the distal torsion group. However, there was no significant difference in their postoperative clinical outcomes. Conclusion: Through a minimum of 2‐year follow‐up visits of patients with patellar dislocation and increased FA, it was found that derotational femoral osteotomy could significantly reduce FA and improve subjective knee function. The pattern of torsion distribution did not significantly affect the clinical outcomes of derotational femoral osteotomy. These findings readvised orthopaedic surgeons that derotational femoral osteotomy remains the preferred procedure for correcting rotational malalignment, but that they should be more cautious about its indications. Level of Evidence: Level IV. [ABSTRACT FROM AUTHOR]

In the urban environment, the radar is easily affected by multipath (MP) returns. The problem of detecting point‐like targets in the urban environment with the existence of resolvable MP returns under the background of heterogeneous clutter is addressed. Two adaptive detectors have been devised with a combination of prior information on the environment and echoes of target. The detectors can use the MP echoes in all MP prediction range cells for detection or in some available paths for signal detection by the available path selection algorithm that eliminates the weak signal propagation paths. Remarkably, the proposed decision schemes exhibit the desirable constant false alarm rate property with respect to the unknown parameters of the heterogeneous interference. The performance assessment, conducted on simulated data in terms of detection probability also in comparison with conventional solutions, highlights the effectiveness of the MP exploitation, while the MP signal is strong and shows the detection performance enhancement potential. [ABSTRACT FROM AUTHOR]