Human Pluripotent Stem Cell-Derived Cardiac Tissue-like Constructs for Repairing the Infarcted Myocardium.

High-purity cardiomyocytes (CMs) derived from human induced pluripotent stem cells (hiPSCs) are promising for drug development and myocardial regeneration. However, most hiPSC-derived CMs morphologically and functionally resemble immature rather than adult CMs, which could hamper their application. Here, we obtained high-quality cardiac tissue-like constructs (CTLCs) by cultivating hiPSC-CMs on low-thickness aligned nanofibers made of biodegradable poly(D,L-lactic-co-glycolic acid) polymer. We show that multilayered and elongated CMs could be organized at high density along aligned nanofibers in a simple one-step seeding process, resulting in upregulated cardiac biomarkers and enhanced cardiac functions. When used for drug assessment, CTLCs were much more robust than the 2D conventional control. We also demonstrated the potential of CTLCs for modeling engraftments in vitro and treating myocardial infarction in vivo. Thus, we established a handy framework for cardiac tissue engineering, which holds high potential for pharmaceutical and clinical applications

Knee hemarthrosis after arthroscopic surgery in an athlete with low factor XIII activity

Abstract We report a thirteen-year-old tennis player with knee hemarthrosis caused by low factor XIII activity. She visited our hospital because of medial peripatellar pain for two years. Although there was no abnormal sign in X-ray or MRI, diagnostic arthroscopy was performed. It revealed some cartilage debris, medial plica and complete septum of suprapatellar plica. Removing the debris by washing out and resecting the medial plica, she could return to play tennis without perioperative symptom. Two months after the first operation, her knee got swelling without any apparent cause. Since 20 ml blood was aspirated twice and MRI revealed suprapatellar mass, we performed arthroscopy again. Suprapatellar mass was old blood clot covered with complete suprapatellar plica. Resection of suprapatellar plica and washing out blood clot were performed, and severe postoperative hemarthrosis was progressively occurred. As factor XIII level was 54% preoperatively, we diagnosed that this condition was caused by low activity level of the factor and administered factor XIII concentrates. The level got improved to 129% and then hemarthrosis gradually relieved. She had no signs of recurrence. We should keep in mind of low factor XIII activity case in case of unexplained postoperative hemarthrosis after arthroscopy because consumption of the factor might promote this condition.</p

Early reconstruction should be considered in younger patients with symptomatic mucoid degeneration of the anterior cruciate ligament

Background: Mucoid degeneration of the anterior cruciate ligament (ACL) is mostly observed in middle-aged patients with knee pain and limited range of motion. Although arthroscopic resection of the degenerated ACL is the treatment of choice following the failure of conservative management, the extent of the excision and subsequent ACL reconstruction for postoperative knee instability remains controversial. Case reports: We present four cases of mucoid degeneration of the ACL in patients aged <40 years, and suggest a suitable treatment strategy for younger patients. All four patients (mean age, 33.8 years) were diagnosed with mucoid degeneration of the ACL based on characteristic clinical symptoms and magnetic resonance imaging. Arthroscopic resection of the affected portion of the ACL was performed as follows: partial resection in two cases with limited hypertrophy, and total ACL resection in the remaining two cases with degeneration involving the entire ligament. Preoperative symptoms disappeared in all cases after resection of the lesions. In the two patients with partial resection, the ACL was completely torn during subsequent sports activities despite showing no symptoms of instability for 2 years postoperatively. All four patients, including the two treated by total resection, underwent ACL reconstruction using an autogenous hamstring tendon. Conclusion: Considering the rupture of residual ACL fibres after partial resection and the inevitability of total ACL resection due to degeneration of the entire ligament, ACL reconstruction should be considered in younger patients with symptomatic mucoid degeneration of the ACL

Simultaneous MPFL and LPFL reconstruction for recurrent lateral patellar dislocation with medial patellofemoral instability

We report an extremely rare case of both recurrent lateral patella dislocation and medial patellofemoral instability, following prior operations to correct patella maltracking. Manual translation of the patella revealed medial and lateral instability with a positive apprehension sign. 3-D computer modelling of kinematics based on MRI data demonstrated that the patella deviated laterally at full extension and translated medially with knee flexion. The medial and lateral patellofemoral ligaments were reconstructed simultaneously with hamstring tendons, alleviating peripatellar pain and patellar instability in both directions

All-Inside Suture Repair for Isolated Radial Tears at the Midbody of the Lateral Meniscus

In young athletes, radial tear of the midbody on the semilunar lateral meniscus in stable knees is most common. Conventionally, for this type of tear, meniscectomy has been considered as a first-line treatment. However, meniscectomy does not prevent degenerative change. Therefore, repair is another treatment option for a full radial tear, though this type of tear can be difficult to repair because of the lack of a vascular supply. Compared with conventional transcapsular suture techniques (e.g., inside-out/outside-in techniques or all-inside techniques with implants), all-inside suture (AIS) repair techniques can avoid bunching of the meniscus to the capsule. AIS is considered suitable for restoration of normal structure and movement of the meniscus after repair, which can be advantageous for meniscal healing. However, AIS repair for an isolated radial tear at the midbody of the lateral meniscus has rarely been reported. Therefore, we applied the AIS repair technique for isolated radial tear at the midbody of the semilunar lateral meniscus using a QuickPass SutureLasso with 2-0 FiberWire. This procedure is easier and less invasive, shortening the gap by drawing each stump of the meniscus in the direction of the circumference