Haruhisa Kanaya’s research while affiliated with Tottori University and other places

Purpose This study aimed to investigate the differences in cement penetration between cementing techniques in total knee arthroplasty (TKA). Materials and methods We retrospectively evaluated knee undergone TKA at our hospital for both preoperative and postoperative computed tomographic (CT) evaluations. Cementing was performed with hand mixing and hand packing (HM group) and with vacuum mixing and cement gun use (VM group). We measured the area under the tibial baseplate (sclerotic and nonsclerotic sides) and compared the mean and maximum depths of cement penetration at each area. Results Of the 44 knees evaluated, 20 and 24 knees were in the HM and VM groups, respectively. At the center of the sclerotic side, the mean penetration depths (2.0 ± 0.7 and 2.5 ± 0.7 mm, p = 0.02) and the maximum penetration depths (4.0 ± 0.9 and 5.0 ± 1.6 mm, p = 0.02) were significantly deeper in the VM group than in the HM group. The correlation between preoperative Hounsfield unit values and mean penetration were r = –0.617 ( p < 0.01) and –0.373 ( p = 0.01) in the HM and VM groups, respectively. Conclusion The cementing technique of vacuum mixing and using a cement gun allowed for deeper cement penetration compared with the hand mixing and hand packing technique, even in bone sclerotic sites.

Objectives Osteoarthritis (OA) features ageing-related defects in cellular homeostasis mechanisms in articular cartilage. These defects are associated with suppression of forkhead box O (FoxO) transcription factors. FoxO1 or FoxO3 deficient mice show early onset OA while FoxO1 protects against oxidative stress in chondrocytes and promotes expression of autophagy genes and the essential joint lubricant proteoglycan 4 (PRG4). The objective of this study was to identify small molecules that can increase FoxO1 expression. Methods We constructed a reporter cell line with FoxO1 promoter sequences and performed high-throughput screening (HTS) of the Repurposing, Focused Rescue and Accelerated Medchem (ReFRAME) library . Hits from the HTS were validated and function was assessed in human chondrocytes, meniscus cells and synoviocytes and following administration to mice. The most promising hit, the histone deacetylase inhibitor (HDACI) panobinostat was tested in a murine OA model. Results Among the top hits were HDACI and testing in human chondrocytes, meniscus cells and synoviocytes showed that panobinostat was the most promising compound as it increased the expression of autophagy genes and PRG4 while suppressing the basal and IL-1β induced expression of inflammatory mediators and extracellular matrix degrading enzymes. Intraperitoneal administration of panobinostat also suppressed the expression of mediators of OA pathogenesis induced by intra-articular injection of IL-1β. In a murine OA model, panobinostat reduced the severity of histological changes in cartilage, synovium and subchondral bone and improved pain behaviours. Conclusion Panobinostat has a clinically relevant activity profile and is a candidate for OA symptom and structure modification.

Background: Anterior cruciate ligament reconstruction (ACLR) is reportedly associated with a higher incidence of deep vein thrombosis (DVT) incidence than other arthroscopic surgical procedures. The aim of this study is to retrospectively investigate the incidence and type of DVT and evaluate the relationship between DVT and risk factors among all patients who underwent ACLR under uniform conditions consisting of mechanical prophylaxis, no medical prophylaxis, and preoperative and postoperative lower extremity venous ultrasonography. Methods: Of the 114 patients who underwent arthroscopic primary ACLR at our hospital who did not have a compound ligament injury or revision surgery, 112 patients were included. Two patients were not examined. DVT evaluation consisted of whole-leg ultrasonography at 1 week after surgery. We evaluated age, sex, body mass index, comorbidities, operative time, tourniquet time, presence of concurrent surgery (meniscus repair/resection or osteochondral column grafting), and non-weight-bearing status at 1 week after surgery as risk factors for DVT. Results: DVT was found in 33 (29.5%) of 112 patients. Of these, 22 (19.6%) had distal DVT and 11 (9.8%) had proximal DVT. Non-weight-bearing status at 1 week after surgery was a statistically significant risk factor for proximal DVT (P = .034). Conclusions: Non-weight-bearing status is an independent risk factor for DVT, suggesting that early weight bearing may reduce the occurrence of DVT.

To establish a histopathological scoring system for changes in subchondral bone in murine models of knee osteoarthritis (OA), three key parameters, subchondral bone plate (Subcho.BP) consisting of the combination of Subcho.BP.thickness (Subcho.BP.Th) and angiogenesis, bone volume (BV/TV) and osteophytes, were selected. The new grading system was tested in two mouse OA models, (1) senescence accelerated mouse (SAM)-prone 8 (SAMP8) as spontaneous OA model with SAM-resistant 1 (SAMR1) as control; (2) destabilization of the medial meniscus in C57BL/6 mice as surgical OA model. Results of the spontaneous OA model showed that Subcho.BP.Th was significantly wider, angiogenesis was greater, and BV/TV was higher in SAMP8 than SAMR1. Notably, subchondral bone score was dramatically higher in SAMP8 at 6 weeks than SAMR1, while OARSI cartilage scores became higher only at 14 weeks. In the surgical OA model, the results were similar to the spontaneous OA model, but osteophytes appeared earlier. There were strong correlations both in Subcho.BP.Th and BV/TV between this scoring system and µCT (r = 0.89, 0.84, respectively). Inter-rater reliabilities for each parameter using this system were more than 0.943. We conclude that this new histopathological scoring system is readily applicable for evaluating the early changes in aging and OA-affected murine subchondral bone.

Objectives The Gekkou-drill® is an industrial drill that is highly efficient due to reduced cutting resistance resulting from its characteristic drill point shape. In this experiment, we compared the degree of thermal damage to bone tissue caused by conventional medical drills and these same drills with Gekkou modifications. Methods Holes were created in the tibias of living pigs using two different 3.2-mm diameter drills and their modified versions. Regarding the drilling parameters, the thrust force was 10 N and the drilling speeds were 800 revolutions per minute (rpm) and 1500 rpm. We compared the original and modified drills in terms of the bone temperature around the drill bit and the total time necessary to create each hole, the latter calculated using imaging data captured during drilling. In histopathological examination, the percentages of empty lacunae in osteocytes of the cortical bone beneath the periosteum were evaluated at 400 × magnification with an optical microscope. Results Compared to the original drills, the modified drills required significantly less time to create each hole and caused a significantly lower temperature rise during bone drilling. With the modified drills, the percentages of empty lacunae around the drilling holes were about 1/2–1/3 of those with the original drills, and were significantly lower for both drilling speeds. Conclusions Gekkou-modified medical drills shortened drilling times despite low thrust force, and histopathological assessment demonstrated a significant reduction in osteocyte damage.

The purpose of this study is to determine the influence of debridement in and around the bone tunnels on the prevalence of cyclops lesion (CL), after anterior cruciate ligament reconstruction (ACLR) with hamstring grafts. Our hypothesis was that bone tunnel debridement during ACLR would reduce the prevalence of CL. Methods for debridement in and around the bone tunnels after tunnel drilling were standardized and applied to 38 knees undergoing double-bundle ACLR between 2011 and 2014, Group A (debridement group). Group B (nondebridement group) included 56 knees in which bone tunnel debridement was not performed. Postoperative MRI was performed to evaluate the presence of CL and the following three criteria: (1) the intercondylar site of CL (grade 1–3), depending on its anterior extent along the femoral condyle; (2) posterior bowing of the ACL graft; and (3) the positional relationship between the frontmost fiber of ACL graft and Blumensaat's line. If CL caused loss of extension or pain or discomfort during knee extension, it was defined as symptomatic CL (SCL). CL was detected in 8 cases (21.1%) in Group A and 26 cases (46.4%) in Group B. The prevalence of CL was significantly lower in Group A than in Group B (p = 0.010), and the risk ratio of CL was 0.31 (95% confidence interval: 0.12–0.79). Furthermore, 10 patients in Group B had SCL, compared with none in Group A (p = 0.004). In Group A, the intercondylar site of CL was grade 1 in all cases, while in Group B, the CL grades were 1 (n = 17), 2 (n = 7), 3 (n = 2) (p = 0.008). There were no cases of posterior bowing of the ACL in Group A, but six cases in Group B (p = 0.023). Debridement in and around the bone tunnel is a simple and effective method of preventing CL and SCL after ACLR. The level of evidence for the study is 3.

Background: There are no medical drill specifications capable of achieving bone drilling in a short time under low-thrust and low-speed drilling. Gekkou-drill® is an industrial drill that enables drilling with low cutting resistance by its characteristic point design. Our aims were to develop Gekkou-modified drills by processing to the points of currently available medical drills and to verify whether these modified drills enable less invasive drilling procedure for bone tissue in thermal exposure compared with unmodified medical drills. Materials and methods: Two commercially available 3.2-mm drills were compared before and after Gekkou modification. Drilling of pig tibias was performed at speeds of 300, 800, and 1,500 rpm and a uniform thrust force of 10 N. Temperature at the entry point for bone drilling was measured using a digital thermometer system. The feed rates were calculated using cortical thickness and monitoring data of the digital force gauge. Results: Two unmodified drills could not penetrate the cortical bone on the near side at 300 rpm, even after 5 min of drilling. The maximum temperatures with modified drills were 54.6 °C and 46.2 °C at 300 rpm. At medium to high speeds, those were statistically significantly lower than with unmodified drills (58.5 °C vs. 90.5 °C at 800 rpm, 62.6 °C vs. 80.8 °C and 73.9 °C vs. 104.6 °C at 1,500 rpm). The feed rates for modified drills were 4.9-6.9 times as high as unmodified drills at 800 rpm, and 3.4 to 4.5 times at 1,500 rpm. On the other hand, the feed rates of modified drills at 300 rpm were equal to or higher than those of unmodified drills at 1500 rpm. Conclusion: Gekkou-modified drills clearly suppressed the temperature rise and increased the feed rate compared with conventional drills. Furthermore, it was notable that these modified drills had higher performance even at conditions of low thrust and low speed.

Background: Since in all studies of conservative treatment of lumbar compartment syndrome the follow-up duration was less than 6 months, it is difficult to draw firm conclusions. Purpose: To report a patient with lumbar paraspinal compartment syndrome who was treated conservatively over a follow-up period of 2 years. Study design: This is a case report of a 23-year-old male college student with lumbar paraspinal compartment syndrome who was treated conservatively. Methods: We report a case of a 23-year-old male college student with lumbar paraspinal compartment syndrome who was treated conservatively. We repeatedly checked his physical examination, laboratory tests, lumbar compartment pressures, and magnetic resonance imaging, and surgical teams were readily prepared to operate should the patient's condition worsen. To prevent complications of rhabdomyolysis, hydration and alkalization were performed. We followed him up to 2 years after discharge. Result: Although the temporal changes on MRI up to the 1-year point, the patient continued to have no symptoms. Conclusions: Conservative therapy can be recommended if rhabdomyolysis is under control.