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1.
Injury ; 55(6): 111530, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38637188

ABSTRACT

Newer intramedullary (IM) nails have become another option in the fixation of proximal tibia fractures. There is limited data on the successful use of these implants in intra-articular and extra-articular fractures of the proximal tibia, and no studies assessing the ability of these implants to maintain alignment with early weight bearing. Our objective was to determine whether immediate weight bearing after IM fixation, with or without supplemental plate or screw fixation, of proximal third tibial fractures (OTA/AO 41A-C) results in a change in alignment prior to union. 35 patients with 39 proximal tibia fractures from 2015 to 2020, all treated with IM nailing with or without supplemental plate or screw fixation, all made weight-bearing as tolerated following surgery, were included. The main outcomes were change in medial proximal tibial angle (MPTA) and posterior proximal tibial angle (PPTA) from initial post-operative films to final follow up. 12 fractures were OTA/AO 41 type A, 14 were type B, and 13 were type C. Mean initial MPTA was 87.0 +/-2.53 degrees, while mean initial PPTA was 79.6 +/- 3.50 degrees. The mean change in MPTA was 0.048 +/- 2.8 degrees (P=0.92), and mean change in PPTA was 0.264 +/- 3.67 degrees. 92.3% of fractures had normal final coronal plane alignment, with MPTA between 85.0 and 90.0 degrees. 89.7% of fractures had normal final sagittal plane alignment, with PPTA between 77.0 and 84.0 degrees. No patients required reoperation for malalignment. In OTA/AO type 41 fractures, immediate weight bearing after IM nail fixation, with or without supplemental plate or screw fixation when indicated, leads to minimal change in final coronal or sagittal alignment, and was well tolerated in most patients. [authors blinded for review].


Subject(s)
Bone Nails , Bone Plates , Fracture Fixation, Intramedullary , Tibial Fractures , Weight-Bearing , Humans , Fracture Fixation, Intramedullary/methods , Fracture Fixation, Intramedullary/instrumentation , Weight-Bearing/physiology , Tibial Fractures/surgery , Tibial Fractures/physiopathology , Male , Female , Adult , Middle Aged , Treatment Outcome , Fracture Healing/physiology , Retrospective Studies , Bone Screws , Aged , Young Adult , Radiography
2.
OTA Int ; 7(1): e321, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38449685

ABSTRACT

Posterior malleolus fractures (PMFs) (OTA 43B1.1) are frequently seen in combination with fractures of the fibula, medial malleolus, and distal tibia; they can rarely be seen in isolation. PMFs affect the alignment of the ankle mortise and the stability of syndesmosis. Techniques described for fixation of PMFs include open reduction internal fixation through a posterolateral or posteromedial approach or anterior-to-posterior screw fixation. For selected minimally displaced or nondisplaced fractures of the posterior malleolus, we developed a percutaneous technique through the Achilles tendon for the insertion of a posterior-to-anterior cannulated screw. The technique is described, and a clinical series is reviewed.

3.
J Orthop Trauma ; 37(11): 581-585, 2023 Nov 01.
Article in English | MEDLINE | ID: mdl-37491711

ABSTRACT

OBJECTIVE: Acute compartment syndrome (ACS) is a true emergency. Even with urgent fasciotomy, there is often muscle damage and need for further surgery. Although ACS is not uncommon, no validated classification system exists to aid in efficient and clear communication. The aim of this study was to establish and validate a classification system for the consequences of ACS treated with fasciotomy. METHODS: Using a modified Delphi method, an international panel of ACS experts was assembled to establish a grading scheme for the disease and then validate the classification system. The goal was to articulate discrete grades of ACS related to fasciotomy findings and associated costs. A pilot analysis was used to determine questions that were clear to the respondents. Discussion of this analysis resulted in another round of cases used for 24 other raters. The 24 individuals implemented the classification system 2 separate times to compare outcomes for 32 clinical cases. The accuracy and reproducibility of the classification system were subsequently calculated based on the providers' responses. RESULTS: The Fleiss Kappa of all raters was at 0.711, showing a strong agreement between the 24 raters. Secondary validation was performed for paired 276 raters and correlation was tested using the Kendall coefficient. The median correlation coefficient was 0.855. All 276 pairs had statistically significant correlation. Correlation coefficient between the first and second rating sessions was strong with the median pair scoring at 0.867. All surgeons had statistically significant internal consistency. CONCLUSION: This new ACS classification system may be applied to better understand the impact of ACS on patient outcomes and economic costs for leg ACS.

4.
OTA Int ; 5(3): e194, 2022 Sep.
Article in English | MEDLINE | ID: mdl-36425086

ABSTRACT

Treatment of fractures around the foot and ankle can be challenging in patients who are unable to remain non weight bearing on their lower extremity. Traditional implants are not sufficient to resist loads incurred during weight bearing and can also lead to complications related to wound healing and infection. We describe a technique for fracture fixation of the foot and ankle that uses low profile implants to minimize soft tissue insult combined with multiplanar external fixation to allow for immediate weight bearing.

5.
J Bone Joint Surg Am ; 104(7): 577-585, 2022 Apr 06.
Article in English | MEDLINE | ID: mdl-35139049

ABSTRACT

BACKGROUND: The pelvis is one of the most common locations for metastatic bone disease. While many of the publications that describe surgical treatments focus on periacetabular lesions (Enneking zone II), there is a lack of investigation into lesions in the non-periacetabular areas (zones I, III, and IV). We recently described a minimally invasive percutaneous screw application for metastatic zone-II lesions with excellent results. In the present study, we aimed to extend this approach to the other pelvic areas. METHODS: Twenty-two consecutive patients with painful non-periacetabular pelvic metastatic cancer were included based on retrospective chart review. There were 16 women and 6 men with an average age of 60 years (range, 36 to 81 years). The most common primary cancers were multiple myeloma (7 cases) and breast (5 cases). The most common locations were the sacrum and the ilium. A pathologic fracture was identified in 15 patients. Most of the lesions were treated with multiple large-diameter screws, except for the isolated zone-III lesions. All of the procedures were completed in a standard operating room without the need for special instruments. Radiation therapy was given to 19 patients; the average dose was 15 Gy. The studied outcomes were pain and functionality as assessed by a visual analog scale (VAS) score and the Eastern Cooperative Oncology Group score (ECOG), respectively. RESULTS: There were no surgical complications and no need for blood transfusion. The average follow-up time was 7 months (range, 0.3 to 34.0 months). Two patients died within 4 weeks of surgery due to COVID-19 infection. There was significant improvement in the postoperative VAS pain score (p < 0.0001) and the ECOG score (p < 0.05) when compared with the preoperative scores. There was no implant failure or revision surgery. Local bone-healing was observed in 12 of 14 patients (86%) who survived for >3 months after surgery. CONCLUSIONS: Percutaneous screw application is safe and effective in the treatment of metastatic non-periacetabular pelvic lesions. Given the simplicity of the technique and the instrumentation and the tolerance for concomitant treatments, this approach is worthy of broader consideration. LEVEL OF EVIDENCE: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

6.
OTA Int ; 5(1): e197, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35187414

ABSTRACT

PURPOSE: During the coronavirus disease (COVID) pandemic elective surgeries were cancelled and operative indications curtailed to counteract shortages in resources. We aimed to review each orthopedic operative indication at an urban Level 1 Trauma Center inundated with COVID. We aimed to classify the appropriateness of each operative intervention and determine if exposure to COVID impacted morbidity or mortality. METHODS: All orthopedic procedures between March 16, 2020 and May 16, 2020 were reviewed. The most urgent surgical indication for each procedure was classified by 2 fellowship trained orthopedic trauma surgeons and 2 senior residents. The appropriateness of the operative intervention was determined. The American Academy of Orthopedic Surgery (AAOS) and American College of Surgeons (ACS) guidelines for surgery during the pandemic were considered. RESULTS: Seventy-six surgical encounters were performed on 71 inpatients including 99 total procedures. No outpatient procedures were performed. Fifty-four of 71 patients were male. There was a mean age of 51.6 years. Of 71 patients, 41 presented to the emergency department without trauma activation with a mean time to presentation of 2.7 days post injury. The most urgent surgical indications included 18 hip fractures, 18 periarticular fractures, 17 open fractures, 7 severe infections, 5 pelvic fractures, 5 femoral shaft fractures, 3 spinal injuries, 1 tibial fracture, 1 tendon injury, and 1 clavicle fracture. Four procedures could have been delayed for conservative management without causing significant harm. Upon discharge 13/71 patients had tested positive for COVID, 41/71 had remained negative throughout their hospital stay, and 17/71 patients never were tested. Four patients contracted COVID in the hospital. There were 4 in hospital deaths, 2 attributed to hypoxemic respiratory failure secondary to COVID pneumonia. CONCLUSION: It was determined that 72/76 cases were considered appropriate in following guidelines of the AAOS and ACS. This highlights the value of halting outpatient procedures and limiting patient exposure to COVID. Comprehensive patient/provider discussions addressing the risks, benefits, alternatives to surgery, and the risk of exposure to respiratory illness are vital. It behooves the surgical team to follow established guidelines such as those of the AAOS and ACS when triaging orthopedic patients for a surgical admission.

7.
Trauma Case Rep ; 32: 100427, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33665320

ABSTRACT

Open humeral shaft fractures comprise approximately 2% of all fractures of the humerus. Nearly 20% of open humeral shaft fractures will develop deep infection, increasing the risk of nonunion regardless of treatment method. Recalcitrant septic nonunion of the humeral shaft is a complex and challenging problem. Operative treatment should aim to eradicate infection, address bony defects, and establish a stable construct that affords early motion. We describe the case of a 38-year-old male with a recalcitrant humeral shaft septic nonunion following fixation of an open humeral shaft fracture. Management of the infection consisted of periodic surgical debridement and IV antibiotics, resulting in a 10 cm segmental defect. Definitive fixation was achieved using the combination of an antegrade intramedullary nail, intercalary femoral shaft allograft, compression plating, and autologous bone graft. In addition to achieving bony union, the patient regained his pre-injury ROM and function, which was clinically sustained at 2-year follow-up.

8.
J Surg Oncol ; 123(5): 1316-1327, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33523514

ABSTRACT

Symptomatic peri-acetabular metastatic lesions are often treated with open surgery such as modified Harrington procedures. In an effort to avoid surgical complications inherently associated with open surgical approaches, we developed and recently reported a novel Tripod percutaneous screw technique. The tripod technique is minimally invasive and was found to yield excellent outcomes regarding both pain control and functionality. The procedure is performed in a standard operative theater using fluoroscopic guided percutaneous screws. Despite the simplicity of intraoperative set-up and instrumentation, it is technically demanding. Obtaining the correct fluoroscopic views and troubleshooting intraoperative hurdles can be challenging for even an experienced orthopedic surgeon. The technique and bony conduits were previously described in the trauma literature, however, there are key points of difference in the setting of metastatic disease. Here we provide a compilation of a stepwise graphic guide for the tripod model in the setting of metastatic peri-acetabular lesions, as well as the tips and tricks based on our own experience. These encompass preoperative preparation, operating room settings, intraoperative fluoroscopic guidance, postoperative care, and subsequent conversion to a cemented total hip arthroplasty, if needed.


Subject(s)
Acetabulum/surgery , Arthroplasty, Replacement, Hip/methods , Bone Neoplasms/surgery , Bone Screws , Fracture Fixation, Internal/methods , Neoplasms/surgery , Plastic Surgery Procedures/methods , Bone Neoplasms/secondary , Fluoroscopy , Humans , Neoplasms/pathology , Prognosis
9.
Injury ; 52(4): 757-766, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33069394

ABSTRACT

INTRODUCTION: There is a paucity of research addressing the morbidity and mortality associated with polytrauma in elderly patients. This study aimed to compare the outcomes of elderly trauma patients with an isolated lower extremity fracture, to patients lower extremity fractures and associated musculoskeletal injuries. METHODS: This study is a retrospective review from the National Trauma Database (NTDB) between 2008 and 2014. ICD 9 codes were used to identify patients 65 years and older with lower extremity fractures. Patients were categorize patients into three sub groups: patients with isolated lower extremity fractures (ILE), patients with two or more (multiple) lower extremity fractures (MLE) and, patients with at least one upper and at least one lower extremity fracture (ULE). Groups were stratified into patients age 65-80 and patients >80 years of age. RESULTS: A total 420,066 patients were included in analysis with 356,120 ILE fracture patients, 27,958 MLE fracture patients, and 35,988 ULE fracture patients. The MLE group reported the highest dispatch to ACS level 1 trauma centers at 31.8% followed by the ULE group at 28.5% and the ILE group at 24.7% of patients (p<0.001). The overall rate of complications was highest in the MLE group followed by the ULE and then the ILE group (41.4%, 40.3%, 36.1%, respectively p<0.001). Motility rates in patients >80 years old in the MLE group and ULE group were similar (1.483 vs 1.4432). However, in the 65-80 year group the odds of mortality was 1.260 in the MLE group and 1.450 in the ULE group (p<0.001), such that the odds of mortality after sustaining a MLE fracture increases with age, whereas this effect was not seen in the ULE group. CONCLUSION: Patients who sustained MLE and ULE fractures, had increased mortality, complications and in hospital care requirements as compared to patients with isolated lower extremity injuries. These outcomes are comparable between ULE and MLE fracture patients over the age of 80 however patients 65-80 with ULE fractures had increased mortality as compared patients 65-80 with MLE fractures. Understanding the unique considerations and requirements of elderly trauma patients is vital to providing successful outcomes.


Subject(s)
Leg Injuries , Aged , Aged, 80 and over , Humans , Leg Injuries/epidemiology , Lower Extremity , Morbidity , Retrospective Studies , Trauma Centers
10.
J Orthop Trauma ; 35(7): e254-e257, 2021 07 01.
Article in English | MEDLINE | ID: mdl-33079838

ABSTRACT

SUMMARY: Periprosthetic fractures about the hip and knee are challenging injuries to treat for the orthopaedic surgeon. The pre-existing femoral implant and poor bone quality provide for difficulties in achieving stable fixation. We present a surgical technique and clinical series of 5 patients describing the use and outcomes of a 3.5 screw with a "double washer" technique to achieve bicortical fixation around a femoral prosthesis.


Subject(s)
Arthroplasty, Replacement, Hip , Femoral Fractures , Periprosthetic Fractures , Bone Plates , Bone Screws , Femoral Fractures/diagnostic imaging , Femoral Fractures/surgery , Fracture Fixation, Internal , Humans , Periprosthetic Fractures/diagnostic imaging , Periprosthetic Fractures/surgery
11.
J Bone Joint Surg Am ; 102(7): 592-599, 2020 Apr 01.
Article in English | MEDLINE | ID: mdl-32079881

ABSTRACT

BACKGROUND: Metastatic lesions in the periacetabular region can cause pain and immobility. Symptomatic patients are often treated surgically with a total hip replacement using various modified Harrington methods. These open surgical procedures confer inherent risks. Prolonged recovery and potential complications may delay adjuvant radiation and systemic therapy. METHODS: We describe a novel technique for acetabular reconstruction. Three large-bore cannulated screws are placed percutaneously under fluoroscopy in a tripod configuration to reinforce the mechanical axes of the acetabulum. Increased stability improves pain control and permits weight-bearing. RESULTS: Twenty consecutive patients with periacetabular metastases were treated using the tripod technique. Eighteen patients (90%) had Harrington class-III lesions, and 2 patients had Harrington class-II lesions. The mean surgical time was 2.3 hours. Sixteen patients (80%) were able to get out of bed on postoperative day 1. At 3 months postoperatively, there was significant improvement in pain as documented on their visual analog scale (p < 0.01) and in functionality as measured by the Eastern Cooperative Oncology Group score (p < 0.01). The mean follow-up time was 7 months (range, 0.6 to 20 months). At the most recent follow-up, only 3 among the 16 surviving patients were using opioids chronically for pain. Total hip arthroplasty was performed in 4 patients (20%) in a staged fashion using the previously placed screws as support for a cemented cup and obviating the need for a cage device. Of the 16 patients, 15 could walk either independently (6 patients) or using an ambulatory aid (9 patients). Eight patients with the primary tripod reconstruction survived >6 months postoperatively. They were found to have either new bone formation filling the defects or healing of the pathological fractures. There has been no implant loosening or failure. CONCLUSIONS: The tripod technique is a novel application to provide safe and effective pain relief in the context of periacetabular metastatic disease. It can be easily converted to support a cemented acetabular cup for a total hip replacement should disease progression occur. This technique provides an alternative to open surgery as currently practiced in these patients. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.


Subject(s)
Acetabulum , Bone Neoplasms/secondary , Bone Neoplasms/surgery , Bone Screws , Orthopedic Procedures/instrumentation , Orthopedic Procedures/methods , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Pilot Projects , Retrospective Studies
12.
Int Orthop ; 43(12): 2831-2838, 2019 12.
Article in English | MEDLINE | ID: mdl-31392493

ABSTRACT

INTRODUCTION: Conflicting evidence exists regarding the role of inferior vena cava filters (IVCFs) in the prevention of pulmonary embolism. The aim of this study was to review an institutional policy of prophylactic IVCF placement in all operative pelvic and acetabular fractures as a means of preventing PE by comparing it to a historical prepolicy period of significantly less aggressive IVCF placement. METHODS: The trauma registry of a single level 1 trauma center was retrospectively queried for all pelvic or acetabular fractures for the prepolicy and intervention periods as defined as January 2003-December 2008 and January 2009-December 2014, respectively-yielding 231 patients for analysis. The primary and secondary outcomes measured were the incidence of PE and deep vein thrombosis. RESULTS: The rate of prophylactic IVCF insertion significantly increased during the study period (p < 0.001). The incidence of pulmonary embolism (1.8% vs. 5.1%, p = 0.351) and DVT (19.3% vs. 10.3%, p = 0.231) were not significantly different when comparing the prepolicy and intervention cohorts. In patients with operative fractures, a nonsignificant trend of increasing incidence of DVTs was appreciated in patients with a prophylactic IVCF versus those without prophylactic IVCF (13 vs. 2, p = 0.222). DISCUSSION: A policy of increased use of prophylactic IVCFs in patients with operative pelvic and acetabular fractures failed to reduce the incidence of PE or DVT. In contrast, several case reports and institutional series have published several risks associated with IVCF placement including failure to retrieve temporary IVCF. CONCLUSION: The benefit of prophylactic IVCF in this patient population is unclear.


Subject(s)
Fractures, Bone/surgery , Pelvic Bones/surgery , Vena Cava Filters , Venous Thrombosis/prevention & control , Adult , Aged , Female , Humans , Incidence , Male , Middle Aged , Pulmonary Embolism/etiology , Retrospective Studies , Time Factors , Venous Thrombosis/epidemiology
13.
Am J Orthop (Belle Mead NJ) ; 44(10): 465-70, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26447408

ABSTRACT

Although the treatment of acetabular fractures in adults has evolved substantially, treatment of these injuries in adolescents remains primarily nonoperative. We performed a retrospective review to evaluate outcomes of treatment of adolescent acetabular fractures. We identified 38 adolescent acetabular fractures (patient ages, 11-18 years), all treated by an experienced trauma surgeon. Open reduction and internal fixation (ORIF) was performed in 37 cases, and 1 case was treated nonoperatively. Mean follow-up was 38.2 months. All fractures healed. Reduction was anatomical in 30 cases, imperfect in 7. One patient had surgical secondary congruence, 1 had preoperative deep vein thrombosis, 1 developed a deep infection, and 2 had femoral head avascular necrosis and developed posttraumatic arthritis (both had hip dislocations). Of the 38 patients, 34 returned to full activity. At latest follow-up, 29 had no pain, and 6 had mild intermittent pain not limiting activity. ORIF was found to be safe and to result in predictable union. We therefore advocate a more aggressive strategy. Given our low complication rate, we recommend nonoperative management only for stable, minimally displaced fractures (<1 mm). Unstable fractures, fractures with any hip subluxation, and fractures displaced more than 1 mm should be managed with ORIF. As reported in adults, articular injury often is associated with secondary degenerative arthritis. This association is expected in adolescents as well. Given adolescents' life expectancy subsequent to injury and surgery, any late posttraumatic arthritis will have a significant impact on quality of life over the long term, with increased duration compared with adults.


Subject(s)
Acetabulum/injuries , Fracture Fixation, Internal/adverse effects , Fractures, Bone/surgery , Joint Dislocations/surgery , Adolescent , Child , Female , Fractures, Bone/complications , Humans , Joint Dislocations/complications , Male , Retrospective Studies , Treatment Outcome
14.
J Bone Joint Surg Am ; 95(24): 2170-6, 2013 Dec 18.
Article in English | MEDLINE | ID: mdl-24352770

ABSTRACT

BACKGROUND: Tibial nonunion is disabling, but to our knowledge no quantitative evaluation of its effect on health-related quality of life has been reported. METHODS: We evaluated 243 tibial shaft fracture nonunions in 237 consecutive patients (seventy-nine female [age, 49.4 ± 14.9 years] and 158 male [age, 46.3 ± 15.4 years]) who were referred to a single surgeon at our tertiary care center over a ten-year period. The most frequently affected tibial segment was the distal third (49%), and infection was present in 18% of all cases. RESULTS: The Short Form (SF)-12 Physical Component Summary score averaged 27.4 ± 6.7, indicating an extremely disabling effect on physical health. The AAOS (American Academy or Orthopaedic Surgeons) Lower Limb Core Scale score averaged 52.0 ± 19.4, also consistent with high levels of physical disability attributable to the lower limb. The SF-12 Mental Component Summary score averaged 42.3 ± 7.1, indicating a substantial detrimental effect on mental health. CONCLUSIONS: The impact of tibial shaft fracture nonunion on physical health was comparable with the reported impact of end-stage hip arthrosis and worse than that of congestive heart failure. Tibial shaft fracture nonunion is a devastating chronic medical condition that negatively affects both physical and mental health and quality of life.


Subject(s)
Fractures, Ununited/psychology , Pain/psychology , Quality of Life/psychology , Tibial Fractures/psychology , Adult , Aged , Disability Evaluation , Female , Fractures, Ununited/surgery , Health Status , Humans , Male , Middle Aged , Tibial Fractures/surgery
15.
J Orthop Trauma ; 27(6): 345-51, 2013 Jun.
Article in English | MEDLINE | ID: mdl-22773018

ABSTRACT

OBJECTIVES: The purpose of this study is to compare open reduction and internal fixation of the patella with a locking plate and tension-band construct (PF) versus cannulated screws and tension-band fixation (SF). The hypothesis is that both constructs will have similar failure loads with simulated extension loading. METHODS: Transverse patellar fractures were created in 10 cadaveric pairs of legs and were fixed with either PF or SF. Dual-energy X-ray Absorptiometry (DXA) scans of all calcanei measured bone mineral density (BMD). Using an MTS 810 servohydraulic testing machine, each leg cycled to full extension 10 times before loading to failure. A differential variable reluctance transducer measured the distraction of the patella. Data were analyzed using paired t test analysis and bivariate analysis for Pearson correlation coefficients. RESULTS: There was no difference in the BMD between the PF and the SF groups (P = 0.367). No measurable differences occurred during the 10 cycles, and load at clinical failure was not significantly different between the 2 fixation groups (P = 0.38). Stiffness during the final loading cycle was significantly higher for the SF group (P = 0.008). Ultimate strength of fixation was significantly higher in PF group (P = 0.048). BMD was not correlated to the ultimate strength of SF (P = 0.112), but was correlated for PF (P = 0.025). CONCLUSIONS: Based on our results, PF provides comparable strength to SF, and it seems to be a safe and effective alternative to the current gold standard.


Subject(s)
Bone Plates , Bone Screws , Fracture Fixation, Internal/instrumentation , Fracture Fixation, Internal/methods , Fractures, Bone/physiopathology , Fractures, Bone/surgery , Patella , Bone Density , Cadaver , Equipment Failure Analysis , Female , Friction , Humans , Male , Patella/injuries , Patella/physiopathology , Patella/surgery , Prosthesis Design , Tensile Strength , Treatment Outcome
16.
Acta Biomater ; 8(5): 1768-77, 2012 May.
Article in English | MEDLINE | ID: mdl-22293583

ABSTRACT

The purpose of this study was to develop and characterize a chitosan gel/gelatin microsphere (MSs) dual delivery system for sequential release of bone morphogenetic protein-2 (BMP-2) and insulin-like growth factor-1 (IGF-1) to enhance osteoblast differentiation in vitro. We made and characterized the delivery system based on its degree of cross-linking, degradation, and release kinetics. We also evaluated the cytotoxicity of the delivery system and the effect of growth factors on cell response using pre-osteoblast W-20-17 mouse bone marrow stromal cells. IGF-1 was first loaded into MSs, and then the IGF-1-containing MSs were encapsulated into the chitosan gel which contained BMP-2. Cross-linking of gelatin with glyoxal via Schiff bases significantly increased thermal stability and decreased the solubility of the MSs, leading to a significant decrease in the initial release of IGF-1. Encapsulation of the MSs into the chitosan gel generated polyelectrolyte complexes by intermolecular interactions, which further affected the release kinetics of IGF-1. This combinational delivery system provided an initial release of BMP-2 followed by a slow and sustained release of IGF-1. Significantly greater alkaline phosphatase activity was found in W-20-17 cells treated with the sequential delivery system compared with other treatments (P<0.05) after a week of culture.


Subject(s)
Bone Morphogenetic Protein 2/administration & dosage , Chitosan/chemistry , Delayed-Action Preparations/pharmacology , Gelatin/chemistry , Insulin-Like Growth Factor I/administration & dosage , Osteoblasts/cytology , Tissue Engineering/methods , Animals , Bone Morphogenetic Protein 2/chemistry , Capsules/chemistry , Cell Differentiation/drug effects , Cell Line , Delayed-Action Preparations/chemical synthesis , Gels/chemistry , Insulin-Like Growth Factor I/chemistry , Materials Testing , Mice , Osteoblasts/drug effects
18.
J Biomed Mater Res B Appl Biomater ; 99(2): 380-90, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21905214

ABSTRACT

We investigated the effect of sustained release of bone morphogenetic protein-2 (BMP-2) from an injectable chitosan gel on osteoblastic differentiation in vitro. We first characterized the release profile of BMP-2 from the gels, and then examined the cellular responses of preosteoblast mouse stromal cells (W-20-17) and human embryonic palatal mesenchymal (HEPM) cells to BMP-2. The release profiles of different concentrations of BMP-2 exhibited sustained releases (41% for 2 ng/mL and 48% for 20 ng/mL, respectively) from the chitosan gels over a three-week period. Both cell types cultured in the chitosan gels were viable and significantly proliferated for 3 days (p < 0.05). Chitosan gels loaded with BMP-2 enhanced ALP activity of W-20-17 by 3.6-fold, and increased calcium mineral deposition of HEPM by 2.8-fold at 14 days of incubation, compared to control groups initially containing the same amount of BMP-2. In addition, schitosan gels loaded with BMP-2 exhibited significantly greater osteocalcin synthesis of W-20-17 at seven days, and of HEPM at both 7 and 14 days compared with the control groups (p<0.05). This study suggests that the enhanced effects of BMP-2 released from chitosan gels on cell differentiation and mineralization are species and cell type dependent.


Subject(s)
Bone Morphogenetic Protein 2/biosynthesis , Chitosan/administration & dosage , Chitosan/chemistry , Drug Delivery Systems , Osteoblasts/cytology , Alkaline Phosphatase/metabolism , Animals , Anthraquinones/pharmacology , Biocompatible Materials/chemistry , Bone Marrow Cells/cytology , Calcium/chemistry , Cell Differentiation , Cell Line , Cell Proliferation , Gels/chemistry , Humans , In Vitro Techniques , Mice , Stromal Cells/cytology , Time Factors
19.
Eur Polym J ; 47(8): 1569-1577, 2011 Aug 01.
Article in English | MEDLINE | ID: mdl-21892228

ABSTRACT

Porous ß-tricalcium phosphate (ß-TCP) has been used for bone repair and replacement in clinics due to its excellent biocompatibility, osteoconductivity, and biodegradability. However, the application of ß-TCP has been limited by its brittleness. Here, we demonstrated that an interconnected porous ß-TCP scaffold infiltrated with a thin layer of poly (lactic-co-glycolic acid) (PLGA) polymer showed improved mechanical performance compared to an uncoated ß-TCP scaffold while retaining its excellent interconnectivity and biocompatibility. The infiltration of PLGA significantly increased the compressive strength of ß-TCP scaffolds from 2.90 MPa to 4.19 MPa, bending strength from 1.46 MPa to 2.41 MPa, and toughness from 0.17 MPa to 1.44 MPa, while retaining an interconnected porous structure with a porosity of 80.65%. These remarkable improvements in the mechanical properties of PLGA-coated ß-TCP scaffolds are due to the combination of the systematic coating of struts, interpenetrating structural characteristics, and crack bridging. The in vitro biological evaluation demonstrated that rat bone marrow stromal cells (rBMSCs) adhered well, proliferated, and expressed alkaline phosphatase (ALP) activity on both the PLGA-coated ß-TCP and the ß-TCP. These results suggest a new strategy for fabricating interconnected macroporous scaffolds with significantly enhanced mechanical strength for potential load-bearing bone tissue regeneration.

20.
Plast Reconstr Surg ; 128(2): 467-473, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21502908

ABSTRACT

BACKGROUND: Percutaneous fixation of fractures of the scaphoid is well documented in the acute setting by both dorsal and volar methods. What is not commonly discussed is the use of this method for delayed unions and nonunions of the scaphoid. The authors present their case series of patients who underwent dorsal percutaneous fixation for delayed union or nonunion of the scaphoid. METHODS: This study retrospectively reviewed eight consecutive patients (six male patients and two female patients) with a delayed union (8 to 12 weeks) or nonunion (≥13 weeks) of the scaphoid waist treated with dorsal percutaneous cannulated screw fixation. The indications for surgery included failure of conservative treatment, pain with loss of wrist mobility, and prevention of long-term osteoarthritis. Exclusion criteria included previous surgery, dorsal intercalated segmental instability, fracture displacement of more than 1.0 mm, osteoarthritis, avascular necrosis, and proximal pole nonunion. RESULTS: The union rate was 100 percent, with an average time to union of 7 weeks for the delayed union group (three of eight) and 13 weeks for the nonunion group (five of eight). No statistically significant difference was found between the preoperative and postoperative radiolunate angles, scapholunate angles, and height-to-length scaphoid ratio. All patients were able to return to their preinjury employment after an average of 10 weeks. CONCLUSION: This pilot study demonstrates that the dorsal percutaneous approach to treatment of delayed union and nonunion of stable scaphoid waist fractures can result in predictable union, with minimal morbidity and complications. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.


Subject(s)
Bone Screws , Fracture Fixation, Internal/instrumentation , Fractures, Ununited/surgery , Scaphoid Bone/surgery , Wrist Injuries/surgery , Adolescent , Adult , Female , Fracture Healing , Fractures, Ununited/diagnostic imaging , Humans , Male , Prosthesis Design , Radiography , Retrospective Studies , Scaphoid Bone/diagnostic imaging , Scaphoid Bone/injuries , Time Factors , Treatment Outcome , Wrist Injuries/diagnostic imaging , Young Adult
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