Vascular Compromising Effect of Drilling for Osteochondral Lesions of the Talus: A Three-Dimensional Micro-Computed Tomography Study.

PURPOSE: To explore an optimal drilling depth and direction for osteochondral lesions of the talus based on a 3-dimensional vascular microarchitecture model constructed with micro-computed tomography (microCT). METHODS: Twelve tali were perfused with the contrast agent and then scanned with microCT. The talar dome was divided into 9 zones, and the vessel densities were measured at the subchondral depths of 0 to 5 mm, 5 to 10 mm and 10 to 15 mm in each zone. The anterolateral (AL) and posterolateral (PL) approaches of retrograde drilling were simulated and the vascular compromising effect was evaluated. RESULTS: The vessel density of the 0- to 5-mm depth was lower than that of the 5- to 10-mm (P = .001) and 10- to 15-mm (P = .007) depths, but no significant difference was found between the 5- to 10-mm and 10- to 15-mm depths (P > .9999). The vessel density in the 5- to 10-mm depth of medial talar dome was similar to that of the adjacent zones (P = .05). Vessel density in the 5- to 10-mm depth around the lateral talar dome was higher in the anterior and medial side. The anterolateral approach disturbed the main intraosseous vessels from the tarsal canal-tarsal sinus, causing extensive vascular compromise in the talus neck and body, whereas the posterolateral approach disturbed only the vessels near the tunnel. CONCLUSIONS: The vessel density changed greatly from the subchondral 0- to 5-mm to the 5- to 10-mm depth. The vessel densities of the 5- to 10-mm depth around the medial talar dome were similar, whereas the anterior and medial side of the lateral talar dome was better vascularized. The posterolateral approach caused less vascular damage than the anterolateral approach. CLINICAL RELEVANCE: The anterograde drilling depth was preferable to the subchondral 5- to 10-mm depth. There was no preferred drilling direction for the osteochondral lesion in the medial talar dome, whereas it is preferable to drill anteriorly or medially in the lateral dome. The posterolateral approach might be a safer alternative for retrograde drilling.

Case Report: A Rare Fungal Keratitis Caused by Plectosphaerella Cucumerina.

PURPOSE: To report a rare case of fungal keratitis caused by Plectosphaerella cucumerina. METHODS: This study retrospectively reviewed the medical records of a case of fungal keratitis. RESULTS: Silt-lamp biomicroscopy revealed corneal infiltration and epithelial defects. Anterior segment optical coherence tomography (AS-OCT) and in vivo confocal microscopy (IVCM) were performed to assist in the diagnosis and evaluate corneal conditions. The isolate was identified as Plectosphaerella cucumerina by MALDI-TOF mass spectrometry. The patient was treated with topical 5% pimaricin and oral voriconazole for 1 month and recovered. CONCLUSION: Fungal keratitis caused by Plectosphaerella cucumerina is rare. AS-OCT and IVCM can help locate the lesion and diagnose fungal keratitis. Furthermore, MALDI-TOF mass spectrometry showed potential prospects in the identification of filamentous fungi. Plectosphaerella cucumerina rarely infects humans and is sensitive to antifungal agents such as pimaricin and voriconazole.

A novel transverse talar tunnel achieved less vessel damage and better drilling safety for ATFL reconstruction: a cadaveric study with three-dimensional microCT.

PURPOSE: To introduce a novel transverse tunnel (TT) in anterior talofibular ligament (ATFL) reconstruction, and assess whether it was superior to the tunnels currently used. METHODS: Thirteen fresh cadaveric lower extremities were perfused with lead-based contrast. Talar tunnels were drilled from the ATFL insertion in the following directions: transversely towards the medial side (TT), towards the talar neck (TNT), and towards the anterior, distal, and posterior points of the medial malleolus (AMMT, DMMT, and PMMT, respectively). MicroCT was used to reconstruct the tali, and virtual transosseous and 20-mm blind-ended tunnels were generated. The graft bending angle, vascular compromise caused by the tunnels, and the minimum distances from the tunnels to the chondral surfaces were evaluated. RESULTS: The bending angles between the ATFL and the TT, TNT, AMMT, DMMT, and PMMT were 47.3±7.9°, 41.5±7.7°, 57.0±6.0°, 63.9±11.7°, and 87.9±6.2°, respectively. The proportion of damaged intraosseous vessels was significantly less for the TT (7.8±2.7%) compared with the AMMT (10.0±5.2%), DMMT (15.5±6.5%), and PMMT (16.9±3.9%). Both the TNT and the AMMT carried a high risk of joint penetration, with respective minimum distances of 2.2±1.7 mm and 1.4±1.0 mm from the tunnel to the cartilage; in contrast, the TT, DMMT, and PMMT had larger safety margins, with minimum distances of 5.4±0.8 mm, 8.9+2.7 mm, and 6.0±1.2 mm. The blind-ended tunnels caused less vascular compromise and had larger minimum distances to the cartilage (better drilling safety) than the transosseous tunnels for all tunnel directions. CONCLUSION: The TT achieves a superior graft bending angle and intraosseous blood supply protection than the AMMT, DMMT, and PMMT, and is less likely to result in cartilage damage than the TNT. The 20-mm blind-ended tunnels achieve less vessel damage and better drilling safety than transosseous tunnels.

Qualitative and quantitative analysis of patellar vascular anatomy by novel three-dimensional micro-computed-tomography: Implications for total knee arthroplasty.

BACKGROUND: The blood supply of the patella is highly related to patellofemoral complications in total knee arthroplasty. The purpose of this study was to determine (1) the dominant blood supply for the patella and (2) the anatomic characteristics of the extraosseous and intraosseous vascularity of the patella. METHODS: In 13 fresh cadaveric knees, the femoral arteries were cannulated and perfused with a lead-based contrast agent. Patellae were harvested and scanned with a micro-computed-tomography scanner. The three-dimensional microarchitecture of the vascularity was reconstructed and evaluated. For the volumetric analysis, the vessel densities of the anterior, central and subchondral sides were compared. RESULTS: A well-anastomosed prepatellar vascular network was found to cover the anterior surface of the patella, with main arteries from multiple directions, yielding 18.8 ±â€¯3.1 (standard deviation) intraosseous branches into the patella. Along the intraosseous branches of the prepatellar vascular network, vessel density decreased (P < 0.001) by 0.54 ±â€¯0.29% on the anterior side, 0.40 ±â€¯0.24% on the central side and 0.23 ±â€¯0.19% on the subchondral side. Arteries in the infrapatellar fat pad produced 5.1 ±â€¯1.8 intraosseous branches, mainly located in the distal apex. Almost no arteries penetrated into the patella from the quadriceps tendon, patellar ligament or medial/lateral retinaculum. CONCLUSION: The prepatellar vascular network is the dominant blood supply. Close exposure and extensive dissection around the patella should be avoided to preserve the prepatellar vascular network. The infrapatellar fat pad was recommended to be preserved when a lateral reticulum release was performed.