Pathophysiology of abnormal compensation ability of the subtalar joint in the varus knee.

BACKGROUND: In recent years, the involvement of the compensation ability of the subtalar joint in lower extremity alignment has been reported. We previously showed that hindfoot alignment angle (HAA) is an indicator of compensation ability of the subtalar joint. The abnormal compensation ability of the subtalar joint was defined by the mobility of the subtalar joint, and evaluation of the mobility of the subtalar joint may help to further clarify the pathophysiology of abnormal compensation ability of the subtalar joint. This study was performed to evaluate the mobility of the subtalar joint and clarify the pathophysiology of abnormal compensation ability of the subtalar joint in the varus knee. METHODS: Seventy-two knees of 72 patients aged ≥40 years with varus knee were included in this study. Preoperative radiographs were used for measurement of this study parameters. Based on our previous study, we defined HAA of ≥15.9°as abnormal compensation ability of the subtalar joint. The patients were divided into an abnormal group (A-group) and normal group (N-group). All measurement parameters were compared between the groups, and correlations between the HAA and each measurement parameter were analyzed. RESULTS: The weight-bearing hindfoot angle (WBHA) (p < 0.001) and non-weight-bearing hindfoot angle (non-WBHA) (p = 0.003), were significantly greater in the A-group than in the N-group. Conversely, the ratio of change in hindfoot alignment (p = 0.006), were significantly smaller in the A-group than in the N-group. The HAA was positively correlated with WBHA (r = 0.66) and non-WBHA (r = 0.43) and negatively correlated with the ratio of change in hindfoot alignment (r = -0.32). CONCLUSIONS: The pathophysiology of abnormal compensation ability of the subtalar joint in the varus knee is thought to involve a state of increased valgus of hindfoot alignment and an inability to move into normal hindfoot alignment. LEVEL OF EVIDENCE: Level Ⅲ, retrospective study.

Influence of hindfoot alignment on postoperative lower limb alignment in medial opening wedge high tibial osteotomy.

INTRODUCTION: We have experienced unexpected under-correction after medial opening wedge high tibial osteotomy (MOWHTO). Although the tibia was corrected accurately, the postoperative mechanical axis (MA) was less than 57%. The purpose of this study was to evaluate the relationship between hindfoot alignment and postoperative lower limb alignment, and to reveal whether hindfoot alignment affects lower limb alignment after MOWHTO. Our hypothesis was that hindfoot alignment influences the postoperative MA in MOWHTO. MATERIALS AND METHODS: This study was a retrospective comparative study. The study cohort comprised 43 knees in 43 patients who underwent MOWHTO and had standing long-leg anteroposterior view and hindfoot alignment view radiographs taken preoperatively and at 3 months postoperatively. To evaluate the hindfoot alignment, the absolute value of the ankle joint line orientation relative to the ground was added to the absolute value of the hindfoot angle. We defined a postoperative MA of 57-67% as acceptable correction (A group) and a MA of < 56% as under-correction (U group). The two groups were analyzed to identify factors that affected postoperative limb alignment. RESULTS: The preoperative hindfoot alignment angle was significantly larger in the U group than the A group. The preoperative hindfoot alignment angle was a significant predictive factor of the postoperative MA, and the cut-off value that distinguished under-correction from acceptable correction was 15.9 degrees. CONCLUSION: Abnormal hindfoot alignment is one of the causes of under-correction after MOWHTO. Attention should be paid to the preoperative ankle joint line orientation relative to the ground and hindfoot angle. If the preoperative hindfoot alignment angle is ≥ 15.9 degrees, surgeons should reconsider the operative procedure and correction angle. LEVEL OF EVIDENCE: Therapeutic level III, retrospective study.

Soft tissue stabilization of the hinge position in medial closed wedge distal femoral osteotomy: an anatomical study.

BACKGROUND: Soft tissue has an important role in stabilizing the hinge point of medial closed wedge distal femoral osteotomy (MCWDFO). However, there are conflicting data on the soft tissue anatomy around the hinge point of MCWDFO and, therefore, further anatomical data are needed. The purposes of the study were to: 1) anatomically analyze the soft tissue around the hinge point of MCWDFO; 2) radiologically define the appropriate hinge point to prevent an unstable hinge fracture based on the result of the anatomical analysis; and 3) histologically analyze the soft tissue based on the result of the anatomical analysis. METHODS: In 20 cadaveric knees, the capsule attachment of the distal lateral side of the femur was marked with a radiopaque ball bearing. A digital planning tool was used to calculate the area of the marked capsule attachment around the ideal hinge point of MCWDFO on radiographs. The soft tissue around the hinge point was histologically examined and the periosteal thickness was measured and visualized graphically. The graph and radiograph were overlayed using image editing software, and the appropriate hinge position was determined based on the periosteal thickness. RESULTS: As a result, the periosteal thickness of the distal lateral femur tended to rapidly decrease from the metaphyseal region toward the diaphyseal region. The overlayed graph and radiograph revealed that the periosteal thickness changed in the region corresponding to the apex of the turning point of the femoral metaphysis in all cases. CONCLUSIONS: In conclusion, the periosteum might support the hinge of MCWDFO within the area surrounded by the apex of the turning point of the femoral metaphysis and the upper border of the posterior part of the lateral femoral condyle.

Evaluation of the hindfoot alignment before and after total knee arthroplasty.

Background: Open wedge high tibial osteotomy (OWHTO) and total knee arthroplasty (TKA) alter the ankle joint line obliquity (AJLO) to be more horizontal relative to the ground and aligns the valgus subtalar joint (SJ) neutrally. A previous study of the hindfoot alignment angle (HAA) showed that lower limb alignment after OWHTO becomes under-corrected because of abnormal compensation by the SJ. However, because TKA can exclude effects of femorotibial joint instability, analysis of a post-TKA cohort enables a more accurate evaluation of SJ compensation than analysis of a post-OWHTO cohort. In the present study, we performed radiographic evaluations before and after TKA to analyze SJ compensation. Methods: Lower limb and hindfoot alignment were measured on plain radiographs in 46 patients (48 knees) who underwent TKA in our department. The patients were divided into Group A (postoperative AJLO within ±1°) and Group B (postoperative AJLO greater than ±1°), and various parameters were compared between the groups. The preoperative HAA that resulted in an abnormal postoperative AJLO was investigated. Results: Group A had a significantly smaller preoperative HAA (p = 0.03) and postoperative HAA (p < 0.01) than Group B. Differences in the preoperative HAA between the two groups showed a cut-off value of 9.06°. Conclusion: Patients with an HAA of more than 9.06° are likely to have abnormal hindfoot compensation.

Mycobacterium avium Complex Lung Disease Complicated With Antiglomerular Basement Membrane Disease: A Case Report.

While both Mycobacterium avium complex (MAC) lung diseases and antiglomerular basement membrane (anti-GBM) antibody disease may cause hemoptysis, no case presenting hemoptysis having both diseases has been reported. A woman in her 80s was admitted due to hemoptysis with acute respiratory failure. MAC was isolated from her sputum, and a positive report for anti-GBM antibody was confirmed in screening for hematuria. This patient has been successfully treated with systemic corticosteroid therapy followed by combination chemotherapy against MAC. Although anti-GBM disease is a rare condition, screening might be recommended in case of uncontrollable hemoptysis as MAC lung disease with hematuria.

Preparation and structure of a single Au atom on the TiO2(110) surface: control of the Au-metal oxide surface interaction.

Three-dimensional Au structures on bare and organic-compound-modified TiO2(110) surfaces were interrogated by Au L3-edge polarization dependent total reflection fluorescence X-ray absorption fine structure (PTRF-XAFS) spectroscopy. On the bare TiO2(110) surface, icosahedral Au55 nanoclusters were the main product found. When the surfaces were modified with ortho or meso mercaptobenzoic acid (o-MBA or m-MBA), Au was atomically dispersed. Sulfur atoms in the o- and m- MBA formed strong covalent bonds with Au to produce stable Au-MBA (o- and m- forms) surface complexes. On the other hand, only oxygen atoms on the surface did not make a strong enough interaction to stabilize the Au species. We discuss how the Au species formed on the modified TiO2(110) surface and the possibility to control the Au structure by the surface modification method.

Fine tuning and orientation control of surface Cu complexes on TiO2(110) premodified with mercapto compounds: the effect of different mercapto group positions.

Three-dimensional structures of vacuum-deposited Cu species formed on TiO2(110) surfaces premodified with three mercaptobenzoic acid (MBA) isomers were studied using polarization-dependent total reflection fluorescence X-ray absorption fine structure (PTRF-XAFS). We explored the possibility of fine tuning and orientation control of the surface Cu structures, including their coordination and configuration against the surface, according to the different mercapto group positions of the three MBA isomers (o-, m-, and p-MBA). Almost linear S-Cu-O (lattice O of TiO2) surface compounds were formed on the three MBA-modified TiO2(110) surfaces; however, the orientation of the Cu species on the o- and m-MBA-modified TiO2(110) surfaces (40-45° inclined from the surface normal) was different from that on the p-MBA-modified TiO2(110) surface (60° from the surface normal). This work suggests that the selection of a different MBA isomer for premodification of a single crystal TiO2(110) surface enables fine tuning and orientation control of surface Cu complexes.