笹沼 秀幸

BACKGROUND: This study aimed to morphologically and histologically examine whether pig is useful as models for rotator cuff tear (RCT). METHODS: The morphology of the scapula and humerus bones was evaluated by taking X-ray and three-dimensional computed tomography (3D CT) scans of the right shoulders of five female pigs (age: 4 months). The rotator cuff (RC) footprint at the humeral insertion of these was observed and its shape was measured. Next, they underwent general anesthesia and an acute rotator cuff tear/rotator cuff repair (RCT/RCR) model was created using a deltoid split approach. Four weeks after surgery, the animals were euthanized, the shoulder joints were harvested, and the repaired RC was evaluated by hematoxylin and eosin staining and toluidine blue staining. RESULTS: The scapula of the pig had a vestigial acromion, in contrast to that in humans. The supraspinatus and infraspinatus tendons were connected so as to overlap each other and attached to the postero-superior part of the greater tuberosity. These tendons were located extra-articularly, separate from the joint capsule. The average antero-posterior length of the foot print was 17.4 ± 0.7 mm on the medial margin and 19.1 ± 2.2 mm on the lateral margin. The maximum medial-to-lateral width of it was 5.1 ± 0.5 mm. In all RCT/RCR models at 4 weeks after surgery, the repaired RC compound tendon was visually confirmed to be continuous with the footprint. Histologically, it was confirmed that regeneration of the four-layer structure of the bone-tendon junction had occurred. CONCLUSION: Porcine supraspinatus and infraspinatus attachment to the greater tuberosity have a structure similar to that of sheep and dogs, which is advantageous for creating the RCT/RCR model. It might be used for future in vivo studies of shoulder joint diseases. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: Pigs could potentially serve as a viable model for rotator cuff tears.

A 72-year-old female patient with a fixed valgus knee deformity due to a Schatzker type V tibial plateau fracture treated with bilateral locking plates 8 years ago was admitted to our clinic with complaints of chronic pain and knee instability when walking. Radiographs revealed Kellgren-Lawrence Classification grade 4 knee osteoarthritis and 20.5° of valgus knee deformity. She was treated with three-dimensional templating and proximal lateral tibial fitting patient-specific instrumentation-assisted mechanically aligned posterior sacrificing total knee arthroplasty with minimal removal of the retained hardware for the internal fixation of the tibial plateau fracture via a lateral approach, resulting in a favorable clinical outcome. The use of proximal lateral tibial fitting patient-specific instrumentation in fixed valgus complex primary total knee arthroplasty for patients with retaining hardware for internal fixation to treat tibial plateau fractures is considered a treatment option to decrease surgical invasion.

BACKGROUND: Osteochondral autograft transplant (OAT), a surgical treatment for capitellar osteochondritis dissecans (OCD), has favorable rates of elbow recovery and return to sports in adolescents. However, few reports have investigated how long patients continue to play baseball after OAT and their satisfaction with their treatment outcome. PURPOSE: To evaluate the rate of boys who played baseball and received OAT for OCD in junior high school or earlier (age <15 years) and continued to play baseball in high school and the players' satisfaction with their elbow function during play. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 32 elbows of boys who played baseball and received OAT at age ≤15 years (mean, 14.1 years) were examined and divided into pitcher (n = 11) and nonpitcher (n = 21) groups according to their player position before surgery. The clinical Timmerman-Andrews score at the end of their high school baseball, participation percentage of players who continued to play baseball, and satisfaction level during play (on a scale of 0-10 during pitching and batting and in a 4-choice format) were compared between the 2 groups. RESULTS: The Timmerman-Andrews scores significantly improved after surgery in both groups, with no significant difference between the groups. Of the 32 players, 30 (93.8%) continued to play baseball throughout high school, including all players in the pitcher group and 19 (90.5%) of those in the nonpitcher group. The percentage of players who continued to pitch was 55.6% (6/11) in the pitcher group. Satisfaction with elbow joint function at the time of pitching was significantly lower in the pitcher group. Further, 5 players reported being "a little unsatisfied" because of elbow pain during pitching. All of the players indicated satisfaction with elbow function during batting. CONCLUSION: The percentage of players who received OAT for OCD in junior high school and continued to play baseball in high school was favorable. However, satisfaction with elbow function during throwing was lower in pitchers than in nonpitchers. CLINICAL RELEVANCE: Before surgery, consent should be obtained from patients who are pitchers after it is explained that satisfaction with elbow joint function during pitching could be decreased after OAT.

Background: The symptoms of chronic calcifying tendinitis consist of shoulder contracture and impingement sign. However, there have been no reports about the use of imaging studies to differentiate these 2 clinical symptoms. A “burning sign” caused by abnormal blood flow was previously reported in the shoulder joint in patients with frozen shoulder by dynamic magnetic resonance imaging. This burning sign was related to pain. The purpose of this study was to investigate the dynamic magnetic resonance imaging findings in patients with symptomatic chronic calcifying tendinitis and to examine the relationship between the location of the burning sign and the physical findings. Methods: We retrospectively analyzed data for 6 patients with symptomatic chronic calcifying tendinitis (mean age, 55.5 ± 9.3 years 4 women). The range of shoulder motion, impingement sign, and location of the burning sign were assessed. Results: Four patients had an impingement sign without shoulder contracture, and the other 2 patients had shoulder contracture. All the patients with an impingement sign also had a burning sign around the calcium deposit and no enhancement in the rotator interval and axillary pouch. Conversely, all the patients with contracture had a burning sign in the rotator interval and axillary pouch and no enhancement around the calcium deposit. Conclusions: Dynamic magnetic resonance imaging identified 2 types of findings in patients with symptomatic chronic calcifying tendinitis: a burning sign in the rotator interval and axillary pouch or around the calcium deposit. The former pattern may be related to shoulder contracture, whereas the latter may be related to impingement sign.

Objective: In the hypothalamic arcuate nucleus (ARC), orexigenic agouti-related peptide (AgRP) neurons regulate feeding behavior and energy homeostasis, functions connected to bone metabolism. The 3-phosphoinositide-dependent protein kinase-1 (PDK1) serves as a major signaling molecule particularly for leptin and insulin in AgRP neurons. We asked whether PDK1 in AGRP neurons also contributes to bone metabolism. Methods: We generated AgRP neuron-specific PDK1 knockout (Agrp Pdk1(-/-)) mice and those with additional AgRP neuron-specific expression of transactivation-defective FoxO1 (Agrp Pdk1(-/-) Delta 256Foxo1). Bone metabolism in KO and WT mice was analyzed by quantitative computed tomography (QCT), bone histomorphometry, measurement of plasma biomarkers, and qPCR analysis of peptides. Results: In Agrp Pdk1(-/-) female mice aged 6 weeks, compared with Agrp Cre mice, both stature and femur length were shorter while body weight was unchanged. Cortical bone mineral density (BMD) and cancellous BMD in the femur decreased, and bone formation was delayed. Furthermore, plasma GH and IGF-1 levels were reduced in parallel with decreased mRNA expressions for GH in pituitary and GHRH in ARC. Osteoblast activity was suppressed and osteoclast activity was enhanced. These changes in stature, BMD and GH level were rescued in Agrp Pdk1(-/-) Delta 256Foxo1 mice, suggesting that the bone abnormalities and impaired GH release were mediated by enhanced Foxo1 due to deletion of PDK1. Conclusions: This study reveals a novel role of PDK1-Foxo1 pathway of AgRP neurons in controlling bone metabolism primarily via GHRH-GH-IGF-1 axis. (C) 2017 The Authors. Published by Elsevier GmbH. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Purpose: In conventional total knee arthroplasty (TKA) using extramedullary alignment guides, it is not always easy to cut the proximal tibia precisely perpendicular to the tibial axis. The purpose of this study was to compare the radiographic accuracy of cutting the proximal tibia between the use of the bony landmarks of the anterior tibial border and the use of the conventional technique. Methods: A total of 173 patients underwent primary TKA. In 76 TKAs, we used the bony landmark method, and in 97 TKAs, we used the conventional method. In the bony landmark method, we set the coronal alignment in reference to the line connecting the proximal and distal one-third of the anterior tibial border, and we determined the 5° posterior slope in reference to this line. Six months postoperatively, radiological evaluations were performed using full-length standing anteroposterior and lateral radiographs of the knee. Results: No significant differences in the coronal tibial component angle were found between the groups. The posterior tilt of the tibial component was significantly smaller in the bony landmark method than in the conventional method (5.1° ± 2.9° vs. 6.4° ± 3.2°, respectively p = 0.007). The percentage of patients whose posterior tilt of the tibial component was within ±3° of 5° was significantly larger in the bony landmark method than in the conventional method (70 vs. 62 %, respectively p = 0.04). Conclusions: The bony landmark method provided a more accurate posterior tibial slope than the conventional method. However, there was no difference in coronal alignment compared with the conventional method.

The objective of the present study was to compare the intraoperative use of tranexamic acid (TNA) plus intra-articular diluted-epinephrine (DEP) with preoperative autologous blood donations and transfusions in reducing an allogeneic blood transfusion (ABT) in primary unilateral total knee arthroplasty (TKA). Patients (n = 133) treated with unilateral primary TKA were divided into three groups retrospectively: patients administered autologous blood transfusions were assigned to group A (n = 51); patients administered preoperative injections of TNA and postoperative intra-articular injections of DEP were assigned to group B (n = 42); and patients treated with the drain-clamp method in addition to injections of TNA and DEP were assigned to group C (n = 40). The rate of avoidance of ABTs, postoperative blood loss, and complications (DVT/PE, skin problems) were examined. The differences among the three groups were not significant in terms of the proportion of patients requiring no ABTs (94% in group A, 93% in group B and 95% in group C, n.s.). The total blood loss calculated was 1,140 +/- A 451 ml, 852 +/- A 343 ml, and 850 +/- A 296 ml, respectively (group B &gt; A, group C &gt; A, P = 0.0009). The significant complications were not observed in three groups. The results of the study showed that the TNA plus DEP combination exerted a comparable effect with preoperative autologous blood transfusion in avoiding ABTs in unilateral primary TKA. Considering several problems of preoperative autologous blood donation, the use of TNA plus DEP is recommended. In addition, it is highly possible that allogeneic blood transfusions can be avoided for patients with preoperative Hb values a parts per thousand yen10.5 using the method described in this study, and the need for preoperative autologous blood donations can be decreased.

For successful TKA, good soft tissue balance is one of the most important factors; however, it is unknown whether the coronal balance immediately after surgery is maintained with time. We hypothesized, if neutral mechanical alignment was achieved at the time of TKA, some degree of lateral ligamentous laxity could be accepted and the laxity would diminish with time. To confirm this hypothesis, we posed two scientific questions: (1) Does the coronal ligament balance measured immediately after TKA change with time? (2) Does the degree of preoperative varus alignment correlate with the lateral or medial ligamentous laxity observed after TKA? We measured coronal lateral or medial ligamentous laxity in 71 knees with varus deformities immediately after surgery and at 3, 6, and 12 months thereafter. The mean mechanical axis was 15.9A degrees varus preoperatively and 0.4A degrees varus postoperatively. The mean medial ligamentous laxity was relatively constant postoperatively from immediately after surgery to 12 months. However, the mean lateral ligamentous laxity was as much as 8.6A degrees immediately after surgery and decreased to 5.1A degrees at 3 months. The lateral ligamentous laxity immediately after surgery correlated with the preoperative varus mechanical axis. Our data show residual lateral ligamentous laxity observed in preoperative varus deformity may be corrected spontaneously after TKA.