Chien-Jen Hsu

A novel in vitro retinal differentiation model by co-culturing adult human bone marrow stem cells with retinal pigmented epithelium cells

Human retinal pigment epithelium (HRPE) cells are important in maintaining the normal physiology within the neurosensory retina and photoreceptors. Recently, transplantation of HRPE has become a possible therapeutic approach for retinal degeneration. By negative immunoselection (CD45 and glycophorin A), in this study, we have isolated and cultivated adult human bone marrow stem cells (BMSCs) with multilineage differentiation potential. After a 2- to 4-week culture under chondrogenic, osteogenic, adipogenic, and hepatogenic induction medium, these BMSCs were found to differentiate into cartilage, bone, adipocyte, and hepatocyte-like cells, respectively. We also showed that these BMSCs could differentiate into neural precursor cells (nestin-positive) and mature neurons (MAP-2 and Tuj1-positive) following treatment of neural selection and induction medium for 1 month. Furthermore, the plasticity of BMSCs was confirmed by initiating their differentiation into retinal cells and photoreceptor lineages by co-culturing with HRPE cells. The latter system provides an ex vivo expansion model of culturing photoreceptors for the treatment of retinal degeneration diseases.

Surgical management of uncomplicated midshaft clavicle fractures: a comparison between titanium elastic nails and small reconstruction plates

BACKGROUND This study compared titanium elastic nail (TEN) fixation with plate fixation in patients with uncomplicated midshaft clavicle fractures. METHODS The records of 57 patients with midshaft clavicular fractures that were operated on within 2 weeks after injury at Kaohsiung Veterans General Hospital, Kaohsiung City, Taiwan, were retrospectively analyzed. Each patient received either TENs (n = 25) or fixation with a 3.5-mm reconstruction plate (n = 32) depending on the preference of the operating surgeon. Operative parameters, postoperative pain and function scores, complications, and fracture union time were determined. RESULTS There was no difference in the fracture pattern distribution between the 2 groups, and all operations were performed without complications. Operation time, wound size, blood loss, length of hospitalization, and subjective time to pain relief were less for the TEN group than for the 3.5-mm reconstruction plate fixation group (P < .001 for all). Patients in the TEN group showed a greater range of shoulder motion and higher Constant scores than those in the plate fixation group up to 18 weeks after surgery (P < .001 for all). Fewer patients in the TEN group, 4 (16%), requested removal of the implant, as compared with 12 (37.5%) in the plate group. CONCLUSION Fixation of uncomplicated midshaft clavicle fractures with TENs provides adequate fixation and faster relief of pain and return to normal function of the affected shoulder than fixation with 3.5-mm reconstruction plates.

Surgical Treatment of Multifocal Giant Cell Tumor of Carpal Bones With Preservation of Wrist Function : Case Report

We report a rare case of multifocal giant cell tumor of bone involving the trapezium, trapezoid, capitate, and scaphoid with soft tissue extension. Following intralesional resection, an autogenous corticocancellous iliac crest bone graft was used to fill the resultant defect and preserve carpal height and radiocarpal motion. Successful union with no recurrence was noted at 1-year follow-up.

Recurrent prosthetic joint infection due to Salmonella enteritidis: case report and literature review

We read with great interest the recent article ‘‘Recurrent prosthetic joint infection due to Salmonella enteritidis: case report and literature review’’ by De la Torre et al. [1]. The authors report the case of a recurrent prosthetic infection with the involvement of two joints in a 72-year-old man and review the literature. The review of all previously reported cases and the case in question show that a conservative approach using antibiotics alone is insufficient to cure the infection. Prolonged antibiotic treatment and twostage reconstruction with the use of a joint spacer is the best choice for the treatment. We would like to congratulate the authors for their excellent results in such a rare and complicated case. This has clearly outlined the policy that is very useful clinically to manage these types of patients. Furthermore, we wish to bring two opinions to the authors. First, we agree that the development of prosthetic knee infection spreads hematogenously from the focus on the hip joint. But we also believe that the focus of the hip joint was due to ‘‘bacterial translocation’’ (BT), which has been defined as the passage of intestinal bacteria, endotoxins and antigens through the gut mucosa into the circulatory system [2]. Its occurrence is increased in a certain number of clinical pathological conditions like bacterial overgrowth in the small bowel, damage to the gut barrier and systemic immunosuppression [2]. The patient in this case report had rheumatoid arthritis treated with prednisone and methotrexate, and immunocompromised status was suspected. Second, while prophylactic antibiotics are effective in reducing the incidence of infection after hip and knee arthroplasty, the correct antimicrobial agent must be selected. Under the suspicion of usually cultured microorganisms, such as Staphylococcus aureus and coagulasenegative staphylococci, cefazolin and cefuroxime are the preferred antibiotics. Otherwise, clindamycin or vancomycin may be used for patients with a confirmed b-lactam allergy [3]. In this patient, with past history of Salmonella infection and immunocompromised status, we suggest using third-generation cephalosporins or fluoroquinolones for prophylactic antibiotics before arthroplasty. In addition, Gatt et al. [4] have reviewed and summarized many methods to prevent BT, including glutamine supplementation, nutritional support, maintaining splanchnic flow, and the combined use of antibiotics and directed selective gut decontamination regimens.

Use of the Schanz screw as a joystick and the Poller screw in intramedullary nailing for subtrochanteric or proximal femoral fracture

We read with great interest the article titled ‘‘Use of blocking screws in intramedullary fixation of subtrochanteric fractures’’ by Amin et al. [1]. We congratulate the authors on their success in using intramedullary nailing in conjunction with the placement of blocking screws to treat six patients with subtrochanteric fractures. All their patients demonstrated satisfactory results, with alignment and bony union maintained at the final radiographic followup. These types of fractures present with characteristic musculature-induced difficulties to control reduction. The abductors and short external rotators insert over the greater trochanter, and the lesser trochanter is the insertion site for the iliacus and psoas hip flexors. These muscles cause the proximal fragment to develop a flexed, abducted and externally rotated position after a fracture [2]. This deformity cannot be resolved with traction on the fracture table with traction, and it is difficult to find a precise point of entry and achieve excellent reduction. Sadighi et al. [3] reported that percutaneously placed Schanz screws used as joysticks could facilitate closed reduction. Kim et al. [4] described a procedure in which they reamed the proximal fragment progressively up to 13 mm, selected a nail that was 2–3 mm smaller than the estimated diameter of the isthmic portion, and inserted the nail into the proximal fragment and manipulated it in an extended, adducted, and internally rotated direction to achieve good reduction and cross the fracture site. Otherwise, the proximal fragment would have a larger canal diameter compared with the distal fragment, and inadequate alignment with translation would be noted if the proximal reamed canal deviated toward the medial or lateral cortex. Krettek et al. [5] described the clinical application of Poller screws to prevent axial deformities during intramedullary nailing for proximal and distal tibial fractures during intramedullary nailing. Amin et al. [1] termed these screws ‘‘blocking screws’’ and applied them to the proximal femoral fragment, separately targeting the medial one-third and posterior one-third. We developed a simple synthesized technique using the Schanz screw as a joystick and the Poller screw for treatment of subtrochanteric or proximal femoral fractures. With the injured limb under traction on the fracture table, one Schanz screw is inserted over the proximal fragment under fluoroscopic guidance and pushed to cause proximal fragment adduction. It is convenient to find a precise entry point for the nail. A ball-tip guide wire is inserted into the proximal canal after using an awl to create the entry point. The Shanz screw is unscrewed until the lateral third of the canal is occupied as Poller screw. The Schanz screw is maintained in position to keep the make medial cortex contact (extended, adducted, and internally rotated), and the guide wire is progressed across the fracture site. This is C.-Y. Chen K.-C. Lin (&) S.-W. Yang Y.-W. Tarng C.-J. Hsu J.-H. Renn Department of Orthopaedics, Kaohsiung Veterans General Hospital, 386 Ta-Chung 1st Road, Kaohsiung, Taiwan e-mail: orthokcl@gmail.com

WALANT for distal radius fracture: open reduction with plating fixation via wide-awake local anesthesia with no tourniquet

BackgroundThe wide-awake local anesthesia no tourniquet (WALANT) technique is applied during various hand surgeries. We investigated the perioperative variables and clinical outcomes of open reduction and internal fixation (ORIF) for distal radius fractures under WALANT.MethodsFrom January 2015 to January 2017, 60 patients with distal radius fractures were treated, and 24 patients (40% of all) were treated with either a volar or a dorsal plate via WALANT procedure. Of these 24 patients, 21 radius fractures were fixed with a volar plate, and the other 3 were fixed with a dorsal plate. Radiographs; range of motions; visual analog scale (VAS); quick disabilities of the arm, shoulder, and hand (Quick DASH) questionnaire; and time to union were evaluated.ResultsOne of the 24 patients could not tolerate the WALANT procedure and was reported as a failed attempt at WALANT. In the cohort, 23 patients successfully received distal radius ORIF under WALANT procedure. The average age is 60.9 (range, 20–88) years. The average operation time was 64.3 (range, 45–85) minutes, the average blood loss was 18.9 (range, 5–30) ml, and the average of duration of hospitalization is 1.8 (range, 1–6) days. The average postoperative day one VAS was 1.6 (range, 1–3). The average time of union was 20.7 (range, 15–32) weeks. The mean follow-up period was 15.1 (range, 12–24) months. Functional 1-year postoperative outcomes revealed an average Quick DASH score of 7.60 (range, 4.5–13.6) and an average wrist flexion and extension of 69.6° (range, 55–80°) and 57.4° (range, 45–70°). There was no wound infection, neurovascular injury, or other major complication noted.ConclusionsWALANT for distal radius fracture ORIF is a method to control blood loss by the effects of local anesthesia mixed with hemostatic agents. Without a tourniquet, the procedure prevents discomfort caused by tourniquet pain. Without sedation, patients could perform the active range of motion of the injured wrist to check if there is impingement of implants. It eliminates the need of numerous preoperative examinations, postoperative anesthesia recovery room care, and side effects of the sedation. However, patients who are not amenable to the awake procedure are contraindications.

Letter to the Editor. Tranexamic acid for reducing intra- and postoperative blood loss in posterior lumbar interbody fusion: Is it safe enough?

TO THE EDITOR: We read with great interest the recent article by Kushioka et al.2 (Kushioka J, Yamashita T, Okuda S, et al: High-dose tranexamic acid reduces intraoperative and postoperative blood loss in posterior lumbar interbody fusion. J Neurosurg Spine 26:363–367, March 2017), which described the use of intravenous tranexamic acid (TXA) during single-level posterior lumbar interbody fusions. The authors conducted a nonrandomized, retrospective, comparative cohort study with 30 patients in each group (TXA vs no TXA) and found that patients who had received intravenous TXA had lower intraoperative and postoperative blood loss and that TXA administration did not result in any complications. We would like to congratulate the authors for their exciting results, which have helped to clearly outline useful treatment strategies to clinically manage patients undergoing spine surgery with TXA for reducing postoperative blood loss. Nonetheless, we wish to draw attention to the potential complications associated with TXA use by describing our experience. We encountered a 56-year-old male who was otherwise healthy with no history of seizures and who had undergone an L3–5 transforaminal lumbar interbody fusion for spinal stenosis at our facility. We had intravenously administered 3000 mg of TXA (7 mg/kg/hr) and had also applied 2000 mg of TXA on the lumbar spinal wound before closing the wound and placing a drainage tube, which was clamped for 4 hours. Postoperative recovery was unremarkable, and the anesthesiologist confirmed that the patient’s condition remained stable. However, the patient experienced one episode of tonic-clonus epilepsy at 5 hours postsurgery, which was managed by administering intravenous single-dose midazolam. A brain CT showed no intracranial lesion, and the final diagnosis of epilepsy was confirmed by a neurologist. In agreement with our experience, a recent meta-analysis by Lin and Xiaoyi3 reported that the cumulative incidence rate of TXA-associated seizures was 2.7% and that the incidence rate increased with increasing dosage. Lecker et al.4 have reported the occurrence of TXA-associated seizures during the early postsurgical period after cardiac and non-cardiac surgery and in patients receiving other medical treatments. Such seizures usually occur within the first 5–8 hours after surgery, which corresponds to the period of weaning from intravenous sedation. Further, such events tend to persist for a few minutes but do not progress to status epilepticus. Data from the current literature show the occurrence of sporadic seizures after TXA administration during cardiac surgery, particularly with valve replacement or coronary artery bypass grafting because high doses of TXA are used during these procedures to reduce blood loss. Because TXA and glycine are structural analogs, TXA can bind to glycine receptors as a competitive antagonist and inhibit glycine-activated inhibitory signals, which increases muscle excitability and results in seizures. However, anesthetics, such as propofol, isoflurane, sevoflurane, and desflurane, act as positive allosteric modulators of glycine receptors that can reverse such TXA-mediated inhibition of glycine receptors or midazolam binding to GABAA receptor and thereby compensating for the reduction in glycinergic inhibition.4 Therefore, seizure episodes occur during the first 5–8 hours postsurgery because while anesthetic levels are rapidly declining in the CNS during this time, TXA levels are either peaking or only slowly declining.4 In orthopedic surgery, TXA is usually used as an intravenous infusion or topical application during total knee or total hip arthroplasty.1,5 Based on the above mechanism, we cannot exclude the possibility of epilepsy due to TXA use during spine surgery, and surgeons must be aware of the possibility of TXA-related seizures. Such seizures can be easily managed by administering intravenous propofol or midazolam to reverse TXA-induced inhibition of glycinergic receptors.

Voiding dysfunction caused by an intrapelvic synovial cyst that resulted from a screw misplaced when fixing the metal cup during total hip arthroplasty.

1 Department of Orthopaedics, Kaohsiung Veterans General Hospital, 386 Ta-Chung 1st road, Kaohsiung, Taiwan 2 Department of Emergency Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan 3 Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan 4 Section of Urology, Department of Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan 5 School of Nursing, Fooyin University, Kaohsiung, Taiwan