Evaluation of zoledronate, cytochalasin-D, and desferrioxamine on osseointegration in an intra-medullary femoral implant model.

Objective: The rise in primary and revision surgeries utilizing joint replacement implants suggest the need for more reliable means of promoting implant fixation. Zoledronate-(Zol), cytochalasin-D-(cytoD), and desferrioxamine-(DFO) have been shown to enhance mesenchymal stem cell (MSC) differentiation into osteoblasts promoting bone formation. The objective was to determine whether Zol, cytoD, and DFO can improve fixation strength and enhance peri-implant bone volume about intra-medullary femoral implants.

Locally delivered minocycline microspheres do not impair osseointegration of titanium implants in a rat femur model.

Background: The purpose of this study was to determine whether intramedullary administration of extended-release minocycline microspheres would affect osseointegration.

Methods: Twenty-two rats were randomized to minocycline or saline femoral intramedullary injection followed by implantation of titanium alloy rods. Following euthanasia at four-weeks, pushout testing was performed and bone-volume-fraction assessed.

Bone changes after short-term whole body vibration are confined to cancellous bone.

Objective: This study assessed femur properties in 80 adult female rats exposed to a range of whole body vibration amplitudes at 45 Hz over five weeks. Our hypothesis was that an optimal amplitude for whole body vibration would be apparent and would result in increased bone strength.

Methods: Animals were treated in five amplitude groups (0 g, 0.

Deferoxamine-Soaked Suture Improves Angiogenesis and Repair Potential After Acute Injury of the Chicken Achilles Tendon.

Background: A major obstacle to the treatment of soft tissue injuries is the hypovascular nature of the tissues. Deferoxamine (DFO) has been shown to stimulate angiogenesis by limiting the degradation of intracellular hypoxia-inducible factor 1-alpha.

Hypothesis: DFO-saturated suture would induce angiogenesis and improve the markers of early healing in an Achilles tendon repair model.

Improved osseointegration with as-built electron beam melted textured implants and improved peri‑implant bone volume with whole body vibration.

Transcutaneous osseointegrated prostheses provide stable connections to the skeleton while eliminating skin lesions experienced with socket prosthetics. Additive manufacturing can create custom textured implants capable of interfacing with amputees' residual bones. Our objective was to compare osseointegration of textured surface implants made by electron beam melting (EBM), an additive manufacturing process, to machine threaded implants.

Osseointegration of Coarse and Fine Textured Implants Manufactured by Electron Beam Melting and Direct Metal Laser Sintering.

Osseointegrated implants transfer loads from native bone to a synthetic joint and can also function transdermally to provide a stable connection between the skeleton and the prostheses, eliminating many problems associated with socket prostheses. Additive manufacturing provides a cost-effective means to create patient-specific implants and allows for customized textures for integration with bone and other tissues. Our objective was to compare the osseointegration strength of two primary additive manufacturing methods of producing textured implants: electron beam melting (EBM) (mean Ra = 23 μm) and direct metal laser sintering (DMLS) (mean Ra = 10 μm).

Local Injection of Aminoglycosides for Prophylaxis Against Infection in Open Fractures.

Background: The purpose of this study was to determine the efficacy of local wound cavity injections of aqueous aminoglycosides (gentamicin and tobramycin), in conjunction with systemic antibiotics, to lower the prevalence of infection in patients with open fractures.

Methods: Three hundred and fifty-one open fractures were identified by Current Procedural Terminology codes 11011 and 11012. Data on patient demographic characteristics, injury characteristics, infection, and fracture union were obtained from the electronic medical records.

Low-Magnitude, High-Frequency Vibration Fails to Accelerate Ligament Healing but Stimulates Collagen Synthesis in the Achilles Tendon.

Background: Low-magnitude, high-frequency vibration accelerates fracture and wound healing and prevents disuse atrophy in musculoskeletal tissues.

Purpose: To investigate the role of low-magnitude, high-frequency vibration as a treatment to accelerate healing of an acute ligament injury and to examine gene expression in the intact Achilles tendon of the injured limb after low-magnitude, high-frequency vibration.

Study Design: Controlled laboratory study.

An evaluation of prophylactic treatments to prevent post traumatic joint stiffness.

Arthrofibrosis is a major obstacle to restoring joint function after trauma. The objective of this study was to evaluate montelukast, forskolin, and triamcinolone as possible means of prophylaxis against the formation of arthrofibrosis. Forty-eight rats underwent surgical knee trauma with post-operative immobilization in full flexion.

Evaluating effects of deferoxamine in a rat tibia critical bone defect model.

Objectives: Evaluate the use of deferoxamine in a calcium sulfate carrier to promote fracture healing in a critical bone defect model.

Methods: 43 female retired breeders were divided randomly into Control, Carrier, DFO and BMP groups and appropriate agents placed at the osteotomy site.

Results: There was a significant difference in the mean gap between groups Control vs DFO and Control vs BMP.

Transcortical screw fixation of the olecranon shows equivalent strength and improved stability compared with tension band fixation.

Objectives: Currently, the standard for 21-B3.1 olecranon fracture fixation is the tension band wire construct described by the AO foundation. Although this technique effectively repairs displaced olecranon fractures and osteotomies, it is associated with a high rate of secondary surgery for implant removal due to hardware "back out," prominence, and discomfort.

Varying whole body vibration amplitude differentially affects tendon and ligament structural and material properties.

Whole Body Vibration (WBV) is becoming increasingly popular for helping to maintain bone mass and strengthening muscle. Vibration regimens optimized for bone maintenance often operate at hypogravity levels (<1G) and regimens for muscle strengthening often employ hypergravity (>1G) vibrations. The effect of vibratory loads on tendon and ligament properties is unclear though excessive vibrations may be injurious.

Biomechanical effects of steroid injections used to treat pyogenic flexor tenosynovitis.

Background: A recent study from our laboratory has demonstrated improved range of motion in the toes of broiler chickens afflicted with pyogenic flexor tenosynovitis when treated with local antibiotic and corticosteroid injections, without surgical drainage. However, the use of corticosteroids as an adjunct treatment raised peer concern, as steroids are thought to have deleterious effects on tendon strength. The purpose of this study was to compare the tensile strength of the aforementioned steroid treated tendons, to a group of tendons administered with the current standard treatment: systemic antibiotics, surgical drainage and no corticosteroids.

Anteroposterior thickening of the femoral neck with aging decreases the "offset" in men.

Background: The contour of the femoral head-neck junction has been shown to have an effect on femoroacetabular impingement (FAI), which can lead to early osteoarthritis of the hip. This study uses computed tomography (CT) to investigate changes in the femoral head, femoral neck, and joint space with aging.

Hypothesis: The ratio of the diameter of the femoral head to the diameter of the femoral neck would decrease with increasing age, thus diminishing the "offset" of the femoral neck and being a possible mechanism for cam-type FAI and resultant osteoarthritis.

A technical trick which reduces the need for stab incisions when using bone tenaculums for fracture reduction.

During the reduction of fractures using a bone tenaculum, rather than making a stab incision, a frequently successful strategy can be to place a folded operative towel placed between the patient's skin and the head of the tenaculum. Using this technique, the surgeon can decrease scarring and potential stab wound complications. When the angle is too steep for the towel to allow the tenaculum to remain stable during the reduction, the surgeon can use the towel as a safe means of trial and error to determine the necessary alignment of the tenaculum to achieve reduction and consequently the best location at which to make the stab incision for the tine of the tenaculum.

Modified Ollier transtrochanteric approach for the treatment of acetabular fractures.

The purpose of this retrospective clinical study was to evaluate the rates of wound and neurologic complications and clinically significant heterotopic ossification, Brooker stage 3 and 4, with the modified Ollier transtrochanteric approach for the treatment of acetabular fractures. The study group comprised 94 consecutive patients (95 acetabuli) who had unstable acetabular fractures requiring surgical fixation. All patients were treated with open reduction internal fixation via the Ollier approach by a single surgeon (L.

An evaluation of carrier agents for desferoxamine, an up-regulator of vascular endothelial growth factor.

Avascularity and hypoxia result in avascular necrosis and play a negative role in fracture healing. The FDA-approved iron chelating agent, desferoxamine (DFO) in a liquid form, has been shown to induce angiogenesis and improve fracture healing through upregulation of the vascular endothelial growth factor. We were concerned that local injection of DFO would either fail to adequately deliver sufficient drug to the desired site or lead to undesired delivery to adjacent sites.

Effect of prostaglandin E2 injection on the structural properties of the rat patellar tendon.

Background: Increased tendon production of the inflammatory mediator prostaglandin E2 (PGE2) has been suggested to be a potential etiologic agent in the development of tendinopathy. Repeated injection of PGE2 into tendon has been proposed as a potential animal model for studying treatments for tendinopathy. In contrast, nonsteroidal anti-inflammatory drugs (NSAIDs) which inhibit PGE2 production and are commonly prescribed in treating tendinopathy have been shown to impair the healing of tendon after acute injury in animal models.

Relationship between width of greater trochanters and width of iliac wings in tronchanteric bursitis.

Trochanteric bursitis is a common disorder that is characterized by inflammation of the bursa, superficial to the greater trochanter of the femur, leading to pain in the lateral hip, and often occurs because of acute trauma or repetitive friction involving the iliotibial band, the greater trochanter, and the bursa. In the study reported here, we hypothesized that the increased incidence of bursitis may be the result of the increased prominence of the trochanter in relation to the wings of the iliac crest. Distances between the outermost edges of trochanters and iliac wings were measured in 202 patients from the University of North Carolina Health Care System-101 without a known diagnosis and 101 with a clinical diagnosis of trochanteric bursitis.

Surprising evidence of pelvic growth (widening) after skeletal maturity.

Following an increase in length and width during childhood and adolescence, skeletal growth is generally assumed to stop. This study investigates the influence of aging on the dimensions of the pelvis and the L4 lumbar vertebra during adulthood. The dimensions of the pelvis, L4 vertebra, and femoral heads were calculated for 246 patients who had received pelvic and abdominal Computed Tomography scans from the UNC Health Care System.

Whole body vibration increases area and stiffness of the flexor carpi ulnaris tendon in the rat.

Whole body vibration (WBV) has been extensively studied as an anabolic stimulus for bone and muscle. Therapeutic WBV delivers low magnitude, high frequency vibrations to tissues, eliciting biological and structural responses. This study investigated the effect of 0.

Some observations on the subfibrillar structure of collagen fibrils as noted during treatment with NKISK and cathepsin G with mechanical agitation.

We observed the structure of collagen fibrils in rat tail tendons after treatment with NKISK and cathepsin G. NKISK is a pentapeptide that has been previously shown to bind fibronectin, while cathepsin G is a serine protease that cleaves fibronectin but not type I collagen. In tendons treated with NKISK, fibrils were seen to extensively dissociate into smaller-diameter subfibrils.

Corticosteroids as an adjunct to antibiotics and surgical drainage for the treatment of pyogenic flexor tenosynovitis.

Background: Many similarities exist between pyogenic flexor tenosynovitis and other closed-space infections such as septic arthritis. Previous studies have demonstrated that corticosteroids in conjunction with antibiotics considerably improve treatment outcomes in patients with septic arthritis. Using a chicken model, we investigated whether or not corticosteroids in combination with antibiotics and/or surgical drainage could minimize the loss of range of motion typically associated with pyogenic flexor tenosynovitis.

Biomechanical comparison of 3 possible fixation strategies to resist femoral neck shortening after fracture.

In light of recent reports that patients with femoral neck shortening following fracture fixation are dissatisfied with their outcomes, the objective of this study was to compare the compressive strength, or resistance to shortening, of 3 possible strategies for stabilization of the femoral neck that should resist shortening. The proximal portion of 21 synthetic composite femurs were prepared to isolate the femoral neck for study. A 4-mm segment of the femoral neck was removed to simulate a transcervical comminuted fracture that would be expected to shorten under standard treatment conditions.