Kenji Kosugi

Introduction Fracture-related infections (FRIs) are challenging for orthopedic surgeons, as conventional surgical treatment and systemic antimicrobial therapy cannot completely control local infections. Continuous local antibiotic perfusion (CLAP) is a novel and innovative therapy for bone and soft-tissue infections, and is expected to eradicate biofilms by maintaining a sustained high concentration of antimicrobial agents at the infected site. If CLAP therapy can eradicate infection even in cases with implants while preserving the implants, it would be an ideal and effective treatment for local refractory infections. This study aimed to evaluate the usefulness of novel CLAP therapy for FRIs. Methods Nine patients treated with CLAP therapy were retrospectively analyzed. The mean age was 65.9 (43–82) years, and the mean follow-up period was 14.9 (6–45) months. In all cases, the infected sites were related to the lower extremities (tibia, n = 6; fibula, n = 1; hip joint, n = 1; foot, n = 1). All patients underwent similar procedures for this therapy combined with negative-pressure wound therapy after thorough irrigation and debridement of infected tissues. Results The pathogens identified were Staphylococcus aureus (methicillin-resistant S. aureus, n = 5; methicillin-susceptible S. aureus, n = 1), Pseudomonas aeruginosa (n = 3), Enterococcus faecalis (n = 2), Corynebacterium (n = 1), and Enterobacter (n = 1); pathogens were not detected in one case. The mean duration of CLAP was 17.0 (7–35) days. In all cases, implants were preserved until bone union was achieved. Five cases relapsed; however, infection was finally suppressed in all cases by repeating this method. No side effects were observed. Conclusion This novel case series presents treatment outcomes using CLAP therapy for FRIs. This method has the potential to control the infection without removing the implants, because of the sustained high concentration of antimicrobial agents at the infected site, and could be a valuable treatment option for refractory FRIs with implants, in which bone union has not been achieved.

Background: Carpal tunnel steroid injection is a nonoperative intervention for the treatment for idiopathic carpal tunnel syndrome (CTS). The antifibrotic, anti-inflammatory, and antiedematous properties of steroids account for their therapeutic effects in the context of CTS; however, their relative contribution has not been clarified. Methods: Fibroblasts from subsynovial connective tissues (SSCT) were intraoperatively collected from patients with idiopathic CTS and were incubated with or without the steroid triamcinolone acetonide (TA) for 1, 3, and 7 days; the expression of fibrosis-related genes and inflammatory cytokines was evaluated using quantitative reverse transcription-polymerase chain reaction. A clinical prospective study was conducted with patients who received carpal tunnel TA injections. We performed clinical and electrophysiological evaluations before and 1, 3, and 5 months after TA injection; and we compared the median nerve, flexor tendon, and SSCT areas and the median nerve flattening ratio before and 1 month after TA injection using 3-T magnetic resonance imaging (MRI). Results: TA induced downregulation of the fibrosis-related genes Col1A1 (collagen type I alpha 1 chain), Col1A2, and Col3A1 but not the inflammation-related genes. The nerve flattening ratio did not change after TA injection according to the MRI-based observation of the median nerve, flexor tendon, and SSCT areas. Conclusions: The therapeutic effects of injected TA are apparently mediated by its antifibrotic rather than its anti-inflammatory and antiedematous properties. TA probably alters the properties but not the morphology of SSCT. Level of Evidence: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Background: Implants made from bioabsorbable unsintered hydroxyapatite and poly-L-lactate composites (u-HA/PLLA) are widely used in the oral, maxillofacial, and orthopedic fields. This study assess the long-term (> 5 years) outcomes of patients with metacarpal fractures who were surgically treated using bioabsorbable plates and screws (Super-Fixsorb MX40 mesh; Teijin Medical Technology, Osaka, Japan). Methods: A retrospective analysis of six patients with eight metacarpal fractures treated with bioabsorbable plates was done. All patients were followed for more than 5 years post-surgery. The clinical outcomes were evaluated using Q-DASH scores and the grip strength (GS): opposite side ratio. The resorption status of implants was assessed on plain computed tomography (CT) scans at final follow-up appointments. Results: The mean age of the patients at the time of surgery was 29.5 years (16–54), and the median follow-up period was 81.8 months (68–101). All fractures united without displacement after an average of 3.5 months, and there were no implant specific complications associated with the use of absorbable plates. The mean grip strength ratio was 85.1% (56.8–104.5). The mean Q-DASH scores of 11.36 points (0–34.09) was good in all but two patients. We also observed that it took more than 8 years for the plates to be absorbed completely. Conclusions: This study demonstrates that the process of bioabsorption in metacarpal fractures might be completed in about 8 years, and the absorption speeds were different inside and outside of the bone. The bioabsorbable plates are more cost-effective than metallic implants. The potential for bioabsorbable plates to be used in various clinical procedures is promising.

Background: Scaphoid excision and four-corner arthrodesis is an acceptable salvage procedure for the treatment of scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) wrists, since first popularized in the 1980s. We investigated the potential application of novel bioabsorbable plates and screws made of un-sintered hydroxyapatite/poly-L-lactide composite for the treatment of metacarpal fractures. We used this material for the fixation of four-corner fusions for SLAC or SNAC wrists commencing from April 2009. The purpose of this study was to clarify the controversy in the literature regarding the use of these plates. Methods: The surgical procedures and clinical outcomes of four-corner fusions using a bioabsorbable (poly-L-lactic acid and hydroxyapatite) plate were reported. Ten patients (mean age, 59.2 years) with SLAC or SNAC wrists underwent fusions between April 2009 and June 2016. The primary diseases were scapholunate ligament injury, Preiser disease, and scaphoid pseudarthrosis. The mean postoperative follow-up period was 45.9 months (range, 12–86). Results: In all patients, bone union was achieved without dislocation or pain. The mean wrist flexion and extension arc improved from 78.5 degrees before surgery to 90.5 degrees after surgery. Mean grip strength improved from 51 to 69% after surgery, and the Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score improved from 53.5 to 14.3. No complications such as infection, avascular swelling, or tendon adhesion were observed. This implant requires no removal of internal fixation devices, produces stable outcomes, and is an effective fusion technique. Conclusions: We summarized the outcomes of four-corner arthrodesis using bioabsorbable plates. Satisfactory clinical results were shown, with no obvious complications. This novel plate also serves as a good alternative for patients who are allergic to metals. Furthermore, bioabsorbable plates are advantageous as they do not require removal.