Magnetic Seeding of SPIO-BMSCs Into a Biphasic Scaffold Can Promote Tendon-Bone Healing After Rotator Cuff Repair.

BACKGROUND: The tendon-bone interface (TBI) in the rotator cuff has a poor intrinsic capacity for healing, which increases the risk of retear after rotator cuff repair (RCR). However, facilitating regeneration of the TBI still remains a great clinical challenge. Herein, the authors established a novel strategy based on magnetic seeding to enhance the TBI regeneration. HYPOTHESIS: Magnetic seeding bone marrow mesenchymal stem cells labeled with superparamagnetic iron oxide (SPIO-BMSCs) into a biphasic scaffold can promote tendon-bone healing after RCR. STUDY DESIGN: Controlled laboratory study. METHODS: BMSCs were labeled with SPIOs. Prussian blue staining, CCK-8 tests, Western blot, and quantitative reverse transcription polymerase chain reaction (PCR) were used to determine the optimal effect concentration of SPIOs on cell bioactivities and abilities. Then SPIO-BMSCs were magnetically seeded into a biphasic scaffold under a magnetic field. The seeding efficacy was assessed by a scanning electron microscope, and the potential mechanism in chondrogenic differentiation after seeding SPIO-BMSCs into the scaffold was evaluated by Western blot and PCR. Furthermore, the effect of SPIO-BMSC/biphasic scaffold on tendon-bone healing after RCR using a rat model was examined using histological analysis, enzyme-linked immunosorbent assay, and biomechanical evaluation. RESULTS: BMSCs labeled with 100 µg/mL SPIO had no effect on cell bioactivities and the ability of chondrogenic differentiation. SPIO-BMSCs were magnetically seeded into a biphasic scaffold, which offered a high seeding efficacy to enhance chondrogenic differentiation of SPIO-BMSCs via the CDR1as/miR-7/FGF2 pathway for TBI formation in vitro. Furthermore, in vivo application of the biphasic scaffold with magnetically seeded SPIO-BMSCs showed their regenerative potential, indicating that they could significantly accelerate and promote TBI healing with superior biomechanical properties after RCR in a rat rotator cuff tear model. CONCLUSION: Magnetically seeding SPIO-BMSCs into a biphasic scaffold enhanced seeding efficacy to promote cell distribution and condensation. This construct enhanced the chondrogenesis process via the CDR1as/miR-7/FGF2 pathway and further promoted tendon-bone healing after RCR in a rat rotator cuff tear model. CLINICAL RELEVANCE: This study provides an alternative strategy for improving TBI healing after RCR.

Efficacy of Arthroscopic Treatment for Concurrent Medial Meniscus Posterior Horn and Lateral Meniscus Anterior Horn Injury: A Retrospective Single Center Study.

OBJECTIVE: To investigate the effectiveness of arthroscopic surgery for combined tears of the posterior horn of the medial meniscus (PHMM) and the anterior horn of the lateral meniscus (AHLM). METHODS: Between September 2009 and December 2013, a retrospective investigation was performed on 48 patients (48 knees) with combined tears of PHMM and AHLM who underwent arthroscopic surgery. All patients underwent magnetic resonance imaging (MRI) diagnosis in the outpatient department. After admission, other basic examinations were performed. PHMM was treated with partial meniscectomy and AHLM was treated with external-internal suture or partial meniscectomy. Curative effect was evaluated according to Lysholm score and IKDC score. The differences of the functions as well as Lysholm and IKDC scores pre- and postoperatively were compared, while the diagnostic accuracy of MRI and arthroscopy for PHMM and AHLM were compared. RESULTS: Seven patients with combined tears of PHMM and AHLM were misdiagnosed during MRI examination when arthroscopy was used as the gold standard. All patients were followed up for an average of 34.58 months (range 10-52 months) and all incisions healed by first intention with no obvious complication. The preoperative and postoperative Lysholm scores were 47.22 ± 2.77 and 87.36 ± 5.45, respectively. The IKDC scores are 54.73 ± 4.65 preoperatively and 89.62 ± 3.71 postoperatively. The positive rates of the diagnosis through MRI and arthroscopic surgery is 85.42% and 100%, respectively. At the last follow-up, the patients had no pain, weakness, and instability, and tenderness in medial and lateral joint space disappeared. Mcmurray test was weakly positive in four patients. Excellent outcome was achieved in 39 cases, and a good outcome was achieved in five cases; the good to excellent rate was 91.67%. CONCLUSION: MRI examination of combined tears of PHMM and AHLM may result in misdiagnosis. Arthroscopic primary repair seemed to be an effective surgical option for treatment of combined tears of PHMM and AHLM.

Successful treatment for bilateral femoral neck insufficiency fractures: a rare lesion case report and an updated review of the literature.

BACKGROUND: The incidence of insufficiency fracture (IF) at femoral neck is low, accounting for about 5% of all insufficiency fractures, and IF at bilateral femoral neck is less common with more occurrence in athlete or serviceman. With the aging of populations, more cases of bilateral femoral neck IF have occurred recently, while the standard clinical treatment still remains lacking due to the complexity of these patients. CASE PRESENTATION: A 55-year-old male patient complained pain in his bilateral hip, with no history of trauma, glucocorticoid hormone consumption or radiotherapy, and imaging examination revealed fracture nonunion and shortening in his left femoral neck, and double fracture line on the right femoral neck. The patient received a cementless THA for the left femoral neck fracture and conservative treatment for the right side, followed by Elcatonin injection and oral administration of Carbonate D3 Granules. After 4 months of fellow-up, the patient presented improved functional scorings in bilateral hip joints, with no signs of prothesis infection or loosening. CONCLUSION: We present a rare case of bilateral femoral neck IF in a middle-aged male and the treatment is successful. The timely CT and MRI examinations of bilateral hip joints for patients was necessary for orthopedists to select proper therapeutic regimen. In addition, the choice for therapeutic regimen of bilateral femoral IF should not only be based on the professional judgement of orthopedists, but also on the wishes of patients.

Mixed Reality Combined with Three-Dimensional Printing Technology in Total Hip Arthroplasty: An Updated Review with a Preliminary Case Presentation.

Three-dimensional (3D) printing technology, virtual reality, and augmented reality technology have been used to help surgeons to complete complex total hip arthroplasty, while their respective shortcomings limit their further application. With the development of technology, mixed reality (MR) technology has been applied to improve the success rate of complicated hip arthroplasty because of its unique advantages. We presented a case of a 59-year-old man with an intertrochanteric fracture in the left femur, who had received a prior left hip fusion. After admission to our hospital, a left total hip arthroplasty was performed on the patient using a combination of MR technology and 3D printing technology. Before surgery, 3D reconstruction of a certain bony landmark exposed in the surgical area was first performed. Then a veneer part was designed according to the bony landmark and connected to a reference registration landmark outside the body through a connecting rod. After that, the series of parts were made into a holistic reference registration instrument using 3D printing technology, and the patient's data for bone and surrounding tissue, along with digital 3D information of the reference registration instrument, were imported into the head-mounted display (HMD). During the operation, the disinfected reference registration instrument was installed on the selected bony landmark, and then the automatic real-time registration was realized by HMD through recognizing the registration landmark on the reference registration instrument, whereby the patient's virtual bone and other anatomical structures were quickly and accurately superimposed on the real body of the patient. To the best of our knowledge, this is the first report to use MR combined with 3D printing technology in total hip arthroplasty.

Extracellular vesicles from human urine-derived stem cells prevent osteoporosis by transferring CTHRC1 and OPG.

Osteoporosis is a debilitating bone disease affecting millions of people. Here, we used human urine-derived stem cells (USCs), which were noninvasively harvested from unlimited and easily available urine, as a "factory" to obtain extracellular vesicles (USC-EVs) and demonstrated that the systemic injection of USC-EVs effectively alleviates bone loss and maintains bone strength in osteoporotic mice by enhancing osteoblastic bone formation and suppressing osteoclastic bone resorption. More importantly, the anti-osteoporotic properties of USC-EVs are not notably disrupted by the age, gender, or health condition (with or without osteoporosis) of the USC donor. Mechanistic studies determined that collagen triple-helix repeat containing 1 (CTHRC1) and osteoprotegerin (OPG) proteins are enriched in USC-EVs and required for USC-EV-induced pro-osteogenic and anti-osteoclastic effects. Our results suggest that autologous USC-EVs represent a promising novel therapeutic agent for osteoporosis by promoting osteogenesis and inhibiting osteoclastogenesis by transferring CTHRC1 and OPG.

Bone Defects in Revision Total Knee Arthroplasty and Management.

This article reviews the recent updates in revision of total knee arthroplasty (RTKA). We reviewed the recent articles on RTKA in databases including PubMed, Google Scholar, and SCOPUS. Total knee arthroplasty (TKA) involves the replacement of all three compartments of the knee in surgery of the knee joint to restore capacity and function. TKA is one of the most common and reliable surgical treatment options for the treatment of knee diseases. However, some patients require revision of TKA (RTKA) after primary TKA for various reasons, including mechanical wear, implant loosening or breakage, malalignment, infection, instability, periprosthetic fracture, and persistent stiffness. Unfortunately, the overall outcome of RTKA is not as satisfactory as for primary TKA due to the uncertainty regarding the actual success rate and the risk factors for failure. Cementation, modular metal augmentation, bone grafting, autologous bone grafting, allogenic bone grafting, impactation bone grafting, structural bone allografting, metaphyseal fixation, using porous titanium coated press fit metaphyseal sleeves and porous tantalum structural cones, and megaprostheses or customized prostheses are the currently available management options for RTKA. However, most of the management systems possess specific complications. Novel approaches should be developed to improve functional capacity, implant survival rates, and quality of life in a cost-efficient manner.