The arterial supply of the talus has been extensively studied in the past but there is a paucity of information on the arterial supply to the navicular and a very limited understanding of the intra-osseous supply to the surface of either of these bones. This is despite the likely importance of this supply in relation to conditions such as osteochondral lesions of the dome of the talus, and avascular necrosis and stress fracture of the navicular. Using cadaveric limbs, dissection of the source vessels was performed followed by arterial injection of latex. The talus and navicular were then removed en bloc, preserving the integrity of the injected arterial vasculature. The specimens were then processed using a new, accelerated diaphanisation technique. This rendered the tissue transparent, allowing the injected vessels to be visualised and then mapped onto a 3D virtual reconstruction of the bone. The vasculature to the subchondral surfaces of the talus and navicular, and the source vessel entry points that provide arterial supply into the navicular were identified. This study gives quantifiable evidence of the areas of consistently poor blood supply which may help explain the clinical pattern of talar and navicular pathology. It also provides as yet unpublished information on the arterial supply of the human navicular bone

Summary. Arthroscopic decompression of the lunate decreases clinical symptoms and slows progression of Kienböck's Disease. Introduction. The purpose of this study was to investigate the outcomes of patients suffering from avascular necrosis of the lunate, or Kienböck's Disease, who received arthroscopic decompression to treat the ischemic lunate. Previous studies have demonstrated an elevated intraosseus pressure in the ischemic lunate, and it has been hypothesised that ischemia in the lunate is secondary to this elevated pressure and subsequent venous congestion, as opposed to diminished arterial supply. Based on this work we have used decompression of the lunate to prevent progression of the disease. Patients and Methods. 21 patients, (22 wrists), reported to a single surgeon with a chief complaint of unremitting wrist pain and the subsequent diagnosis was Kienböck's disease, stages I, II, IIIA or IIIB. Range of motion measurement and grip strength, as well as self-reported outcome measures such as Disabilities of the Arm, Shoulder and Hand (DASH) and Modified Mayo, were obtained preoperatively and post operatively at 2, 7 and 12 months. The patients were treated operatively with arthroscopic decompression of the lunate. The lunate was approached dorsally at the interosseous lunotriquetral and the scapholunate ligament areas with an arthroscopic shaver until brisk bleeding was achieved upon deflating the tourniquet. In some cases, the core of the lunate had to be penetrated with a 45 k-wire until bleeding was obtained. Of the 22 wrists treated arthroscopically with lunate decompression, 18 had both pre-surgical and post-surgical follow-up evaluations. Results. The patients who underwent lunate arthroscopic decompression surgery demonstrated a statistically significant improvement in DASH score at 7 and 12 months postoperatively (p<0.05). The preoperative DASH score average for this cohort was 51, while post-operative DASH scores averaged 23 and 17 at 7 and 12 months, respectively. The patients also demonstrated some overall improvement in pain, functionality, range of motion, and grip strength as demonstrated by the Modified Mayo wrist score. Notably, the patients demonstrated statistically significant improvement in grip strength post-operatively at 7-months (p<0.05) and 12-months (p<0.01). In addition, there was noted to be improvement in supination and ulnar deviation measurements post-operatively at 7 months and 12 months, respectively. Conclusion. This study demonstrates the clinical outcome of arthroscopic decompression of the lunate in patients suffering from Kienböck's Disease using the patient's subjective evaluations as well as range of motion and grip strength measurements. Arthroscopic decompression of the lunate decreases clinical symptoms and slows progression of Kienböck's Disease using a less invasive surgical intervention