[Augmenting locking plate with autologous bone graft for the treatment of nonunion of long bone fracture in the lower extremity with retaining of the original intramedullary nail].

OBJECTIVE: To explore clinical effect of attaching locking plate with bone grafting based on retaining the original intramedullary nail in treating non-union after intramedullary nail fixation of long shaft fractures of lower limbs. METHODS: A retrospective study was conducted on 20 patients treated with non-union fractures after intramedullary nailing of long shaft fractures of lower limbs from June 2015 to June 2020. All patients were treated with the original intramedullary nailing and bone grafting from the iliac bone, and were underwent open reduction plate internal fixation and bone grafting for old fractures. Among them, 14 were males and 6 were females, aged from 35 to 56 years old with an average of (42.2±9.6) years old. Nine patients were femoral shaft fracture and 11 patients were tibial shaft fracture. According to characteristics of fracture end nonunion, 6 patients were stable/atrophic, 9 patients were unstable/large, and 5 patients were unstable/atrophic. The nonunion time ranged from 8 to 12 months with an average of(9.8±2.0) months after the initial surgery. Visual analogue scale (VAS), knee range of motion, bone healing time, complications and fracture-end healing were recorded before and at the latest follow-up. RESULTS: All patients were followed up for 18 to 48 months with an average of (36.3±10.5) months. The incision of all patients were healed at stageⅠwithout complications such as infection or internal fixation ruptur. Healing time of femur and tibia was (8.5±2.6) months and (9.5±2.2) months. Knee joint motion increased from preoperative (101.05±8.98) ° to postoperative (139.35±8.78) ° at the latest follow-up (t=-12.845, P<0.001). VAS decreased from preoperative (5.15±1.72) to postoperative (0.75±0.96) at the latest follow-up (t=11.186, P<0.001). CONCLUSION: On the basis of retaining the original intramedullary nail, the addition of locking plate internal fixation and autogenous iliac bone grafting have advantages of simple operation, less trauma, fewer complications and high fracture healing rate. It is one of the effective surgical schemes for the treatment of nonunion after intramedullary nail fixation of long bone fracture of lower extremity.

[Arthroscopic cyst removal and wire-guided suture for the treatment of lateral meniscal cyst of knee joint].

OBJECTIVE: To explore clinical effect of arthroscopic cyst removal and wire-guided suture for the treatment of lateral meniscal cyst of knee joint. METHODS: From July 2014 to December 2017, 33 patients with lateral meniscal cyst of knee joint were treated by arthroscopic cysts removal and wire-guided suture, including 13 males and 20 females, aged from 20 to 55 years old with an average age of(36.23 ±2.30) years old, the courses of disease ranged from 3 to 14 months with an average of(4.60±0.83) months; Preoperative MRI examination was clear diagnosed. There were 14 cysts on anterior horn, 18 cysts on meniscal body and 1 cyst on posterior horn;all cysts were solitary, and 3 of them were multilocular. Lysholm score and GLASOW score of knee joint function and clinical efficacy were observed before and after operation at 6 months. RESULTS: All patients were followed up form 6 to 24 months with an average of (7.5±1.2) months. Preoperative symptoms disappeared or significantly alleviated, and all incisions were healed by intention without complication and neurovascular injury. MRI showed meniscal tear areas and cystic defective areas healed, cyst was not recurrenced, healing time ranged form 8 to 12 weeks with an average of (9.6±1.6) weeks, and patients recovered their daily life and exercise. There was significant difference in Lysholm score before operation (61.12±4.35) and after operation at 6 momths(91.32±3.36)(t=46.11, P<0.01);according to GLASOW assessment, 31 patients with excellent recovery, and 2 good. CONCLUSIONS: Arthroscopic cyst removal and wire-guided suture for the treatment of lateral meniscal cyst of knee joint could reserve meniscus, repair injury of meniscus, recover knee joint function after operation, and is worth popularizing.

[Double-plate fixation via combined approaches for the treatment of old tibial plateau fractures of Schatzker type IV].

OBJECTIVE: To explore the clinical efficacy of double-plate fixation for the treatment of old tibial plateau fractures with Schatzker type IV through anterior midline and posteromedial approaches. METHODS: From July 2013 to July 2015, 15 patients with old tibial plateau fractures were treated with internal fixation using locking reconstructive plate for the posteromedial fragment and anatomical locking plate for anteromedial fragment through antero midline and posteromedial approaches. There were 9 males and 6 females, with an average age of 49.2 years old (ranged, 21 to 61 years old). Eight patients had injured in the left side and 7 in the right side. According to Schatzker classification, all patients were type IV. The mean interval from injury to operation was 26.5 days (ranged, 21 to 65 days). The main clinical symptoms before operation were knee joint swelling, pain, deformity and limitation of motion. The X-ray and CT confirmed the fracture type. The indexes such as tibial plateau tibial shaft angle (TPA), femoral tibial angle (FTA) and posterior slope angle (PSA) were compared between immediate postoperation and final follow-up using postoperative X-ray film. The knee functions were evaluated using the HSS (Hospital for Special Surgery) knee score system. RESULTS: Two patients had incision complications which healed by correct treatment, 1 patient had traumatic arthritis. All patients were followed up for mean 16.6 months (ranged, 13 to 24 months). No infections, deep venous thrombosis, implant loosening and breakage, fragment displacement, plateau surface collapse and bone nonunion found. The bone union time ranged from 3 to 8 months (mean 6.07 months) after operation. The average immediate postoperative value of TPA, FTA and PSA were(86.81±1.67)°, (168.00±3.29)° and(10.20±1.47)° respectively; and(86.47±1.67)°, (168.53±3.03)° and (10.54±1.21)° respectively at the final follow-up evaluation, showing no statistical differences(P>0.05). According to the HSS score system, 26.33±3.86 in pain, 20.00±1.79 in function, 16.00±1.55 in range of motion, 8.67±0.94 in muscle strength, 8.53±1.67 in flexion deformity, 9.33±0.94 in joint stability, and the total mean score was 88.86±8.92. The outcomes were excellent in 10 cases, good in 4, and fair in 1. CONCLUSIONS: Double-plate fixation via combined anterior midline and posteromedial approaches is an ideal surgical method for old tibial plateau fractures with Schatzker IV type, showing satisfactory exposure, reliable reduction and fixation, and benefiting for early functional exercise. The short-term clinical results was satisfactory.

Inhibited Bacterial Adhesion and Biofilm Formation on Quaternized Chitosan-Loaded Titania Nanotubes with Various Diameters.

Titania nanotube-based local drug delivery is an attractive strategy for combating implant-associated infection. In our previous study, we demonstrated that the gentamicin-loaded nanotubes could dramatically inhibit bacterial adhesion and biofilm formation on implant surfaces. Considering the overuse of antibiotics may lead to the evolution of antibiotic-resistant bacteria, we synthesized a new quaternized chitosan derivative (hydroxypropyltrimethyl ammonium chloride chitosan, HACC) with a 27% degree of substitution (DS; referred to as 27% HACC) that had a strong antibacterial activity and simultaneously good biocompatibility with osteogenic cells. Titania nanotubes with various diameters (80, 120, 160, and 200 nm) and 200 nm length were loaded with 2 mg of HACC using a lyophilization method and vacuum drying. Two standard strain, methicillin-resistant Staphylococcus aureus (American Type Culture Collection 43300) and Staphylococcus epidermidis (American Type Culture Collection 35984), and two clinical isolates, S. aureus 376 and S. epidermidis 389, were selected to investigate the bacterial adhesion at 6 h and biofilm formation at 24, 48, and 72 h on the HACC-loaded nanotubes (NT-H) using the spread plate method, confocal laser scanning microscopy (CLSM), and scanning electron microscopy (SEM). Smooth titanium (Smooth Ti) was also investigated and compared. We found that NT-H could significantly inhibit bacterial adhesion and biofilm formation on its surface compared with Smooth Ti, and the NT-H with 160 nm and 200 nm diameters had stronger antibacterial activity because of the extended HACC release time of NT-H with larger diameters. Therefore, NT-H can significantly improve the antibacterial ability of orthopedic implants and provide a promising strategy to prevent implant-associated infections.

Bacterial inhibition potential of 3D rapid-prototyped magnesium-based porous composite scaffolds--an in vitro efficacy study.

Bone infections are common in trauma-induced open fractures with bone defects. Therefore, developing anti-infection scaffolds for repairing bone defects is desirable. This study develoepd novel Mg-based porous composite scaffolds with a basal matrix composed of poly(lactic-co-glycolicacid) (PLGA) and tricalcium phosphate (TCP). A unique low-temperature rapid prototyping technology was used to fabricate the scaffolds, including PLGA/TCP (PT), PLGA/TCP/5%Mg (PT5M), PLGA/TCP/10%Mg (PT10M), and PLGA/TCP/15%Mg (PT15M). The bacterial adhesion and biofilm formation of Staphylococcus aureus were evaluated. The results indicated that the Mg-based scaffolds significantly inhibited bacterial adhesion and biofilm formation compared to PT, and the PT10M and PT15M exhibited significantly stronger anti-biofilm ability than PT5M. In vitro degratation tests revealed that the degradation of the Mg-based scaffolds caused an increase of pH, Mg(2+) concentration and osmolality, and the increased pH may be one of the major contributing factors to the antibacterial function of the Mg-based scaffolds. Additionally, the PT15M exhibited an inhibitory effect on cell adhesion and proliferation of MC3T3-E1 cells. In conclusion, the PLGA/TCP/Mg scaffolds could inhibit bacterial adhesion and biofilm formation, and the PT10M scaffold was considered to be an effective composition with considerable antibacterial ability and good cytocompatibility.

In vivo effect of quaternized chitosan-loaded polymethylmethacrylate bone cement on methicillin-resistant Staphylococcus epidermidis infection of the tibial metaphysis in a rabbit model.

Infection of open tibial fractures with contamination remains a challenge for orthopedic surgeons. Local use of antibiotic-impregnated polymethylmethacrylate (PMMA) beads and blocks is a widely used procedure to reduce the risk of infection. However, the development of antibiotic-resistant organisms make the management of infection more difficult. Our in vitro study demonstrated that quaternized chitosan (hydroxypropyltrimethyl ammonium chloride chitosan [HACC])-loaded PMMA bone cement exhibits strong antibacterial activity toward antibiotic-resistant bacteria. Therefore, the present study aimed to investigate the in vivo antibacterial activity of quaternized chitosan-loaded PMMA. Twenty-four adult female New Zealand White rabbits were used in this study. The right proximal tibial metaphyseal cavity was prepared, 10(7) CFU of methicillin-resistant Staphylococcus epidermidis was inoculated, and PMMA-only, gentamicin-loaded PMMA (PMMA-G), chitosan-loaded PMMA (PMMA-C), or HACC-loaded PMMA (PMMA-H) bone cement cylinders were inserted. During the follow-up period, the infections were evaluated using X rays on days 21 and 42 and histopathological and microbiological analyses on day 42 after surgery. Radiographic indications of bone infections, including bone lysis, periosteal reactions, cyst formation, and sequestral bone formation, were evident in the PMMA, PMMA-G, and PMMA-C groups but not in the PMMA-H group. The radiographic scores and gross bone pathological and histopathological scores were significantly lower in the PMMA-H group than in the PMMA, PMMA-G, and PMMA-C groups (P < 0.05). Explant cultures also indicated significantly less bacterial growth in the PMMA-H group than in the PMMA, PMMA-G, and PMMA-C groups (P < 0.01). We concluded that PMMA-H bone cement can inhibit the development of bone infections in this animal model inoculated with antibiotic-resistant bacteria, thereby demonstrating its potential application for treatment of local infections in open fractures.

Inhibited bacterial biofilm formation and improved osteogenic activity on gentamicin-loaded titania nanotubes with various diameters.

Titania nanotubes loaded with antibiotics can deliver a high concentration of antibiotics locally at a specific site, thereby providing a promising strategy to prevent implant-associated infections. In this study we have fabricated titania nanotubes with various diameters (80, 120, 160, and 200 nm) and 200 nm length via electrochemical anodization. These nanotubes were loaded with 2 mg of gentamicin using a lyophilization method and vacuum drying. A standard strain, Staphylococcus epidermidis (American Type Culture Collection 35984), and two clinical isolates, S. aureus 376 and S. epidermidis 389, were selected to investigate the anti-infective ability of the gentamicin-loaded nanotubes (NT-G). Flat titanium (FlatTi) and nanotubes with no drug loading (NT) were also investigated and compared. We found that NT-G could significantly inhibit bacterial adhesion and biofilm formation compared to FlatTi or NT, and the NT-G with 160 nm and 200 nm diameters had stronger antibacterial activity because of the extended drug release time of NT-G with larger diameters. The NT also exhibited greater antibacterial ability than the FlatTi, while nanotubes with 80 nm or 120 nm diameters had better effects. Furthermore, human marrow derived mesenchymal stem cells were used to evaluate the effect of nanotubular topographies on the osteogenic differentiation of mesenchymal stem cells. Our results showed that NT-G and NT, especially those with 80 nm diameters, significantly promoted cell attachment, proliferation, spreading, and osteogenic differentiation when compared to FlatTi, and there was no significant difference between NT-G and NT with the same diameter. Therefore, nanotube modification and gentamicin loading can significantly improve the antibacterial ability and osteogenic activity of orthopedic implants.

Staphylococcus aureus supernatant induces the release of mouse ß-defensin-14 from osteoblasts via the p38 MAPK and NF-κB pathways.

Mammalian ß-defensins are small cationic peptides of approximately 2-6 kDa that have been implicated in mediating innate immune defenses against microbial infection. Previous studies have reported that mouse ß-defensin-14 (MBD­14), based on structural and functional similarities, appears to be an ortholog of human ß-defensin-3 (HBD-3). The aim of this study was to identify the signaling pathways that contribute to the expression of MBD-14 in mouse osteoblasts (OBs) upon contact with methicillin-resistant Staphylococcus aureus (S. aureus) supernatant (SAS) to provide a theoretical basis for the use of MDB-14 as a therapeutic agent in the treatment of intramedullary infection with S. aureus in vivo. The bacterial exoproducts released by S. aureus mainly include a large amount of enterotoxins. Using mouse OBs, the release and regulation of MBD-14 was evaluated by real-time polymerase chain reaction (PCR) and enzyme­linked immunosorbent assay (ELISA) following exposure to SAS. The activation of the p38 mitogen­activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK) and nuclear factor-κB (NF-κB) pathways was determined by western blot analysis. OBs treated with lipopolysaccharide (LPS) were used as the positive control. The results revealed that SAS significantly promoted the phosphorylation of p38 MAPK, NF-κB and the inhibitory subunit of NF-κBα (IκBα) in a time-dependent manner. The treatment of OBs with SB203580 (an inhibitor of p38 MAPK) and pyrrolidine dithiocarbamate (PDTC, an inhibitor of NF-κB) prior to stimulation with SAS significantly inhibited the phosphorylation and mRNA expression of p38 MAPK and NF-κB p65, simultaneously reducing the release of MBD-14. Our findings suggest that the release of MBD-14 is mediated at least in part through the activation of p38 MAPK and NF-κB in response to S. aureus­secreted bacterial exoproducts. Moreover, our data demonstrate the innate immune capacity of OBs under conditions of bacterial challenge to enhance the local expression of this MBD-14, a peptide with anti­staphylococcal activity.

Treatment of thumb soft-tissue defects using a bipedicle island flap of the index finger: anatomical basis and clinical application.

PURPOSE: Reconstruction of the thumb with exposure of bone and tendon is challenging. We designed a bipedicle island flap from the dorsum of the index finger to repair thumb defects. One pedicle includes the radial proper palmar digital artery (PDA) of the index finger, another pedicle includes the first dorsal metacarpal artery (FDMA). The aim of the study was to investigate the anatomical basis and clinical application of this flap. METHODS: Eleven fresh cadaver hands were dissected, the FDMA and the radial proper PDA were exposed. Their origin, distribution and diameter in different locations, especially in the dorsum of the proximal phalanx of the index finger, were examined. Ten patients (11 hands) underwent thumb reconstruction using this flap. During follow-up, the flap survival and hand function were evaluated. RESULTS: The origin of the FDMA in three cadaver hands was abnormal. The FDMA was mainly distributed in the proximal area of the dorsum of the proximal phalanx. The radial proper PDA of the index finger formed one constant dorsal branch, mainly distributing in the middle and distal area of the dorsum of the proximal phalanx. All flaps survived. At follow-up, the span of the first web and the range of motion of the thumbs and index fingers reached more than 94 % of the contralateral finger. All patients were satisfied with the hand function according to the Michigan Hand Outcomes Questionnaire (MHQ). CONCLUSIONS: The bipedicle island flap has two arterial systems to provide sufficient blood supply. This technique provides another option for thumb reconstruction when a large supercharged FDMA island flap needs to be designed, or when there is an additional injury to the radial side of the dorsum of the hand or if there are anatomical variations of the FDMA, or if damage to the FDMA occurs during surgery.