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Concept: Distraction osteogenesis

166

To develop and test a novel, hydraulic, continuous, automated distraction device capable of 3D movements for treatment of mandibular deformities.

Concepts: Distraction osteogenesis

34

More than 2 million bone-grafting procedures are performed each year using autografts or allografts. However, both options carry disadvantages, and there remains a clear medical need for the development of new therapies for massive bone loss and fracture nonunions. We hypothesized that localized ultrasound-mediated, microbubble-enhanced therapeutic gene delivery to endogenous stem cells would induce efficient bone regeneration and fracture repair. To test this hypothesis, we surgically created a critical-sized bone fracture in the tibiae of Yucatán mini-pigs, a clinically relevant large animal model. A collagen scaffold was implanted in the fracture to facilitate recruitment of endogenous mesenchymal stem/progenitor cells (MSCs) into the fracture site. Two weeks later, transcutaneous ultrasound-mediated reporter gene delivery successfully transfected 40% of cells at the fracture site, and flow cytometry showed that 80% of the transfected cells expressed MSC markers. Human bone morphogenetic protein-6 (BMP-6) plasmid DNA was delivered using ultrasound in the same animal model, leading to transient expression and secretion of BMP-6 localized to the fracture area. Micro-computed tomography and biomechanical analyses showed that ultrasound-mediated BMP-6 gene delivery led to complete radiographic and functional fracture healing in all animals 6 weeks after treatment, whereas nonunion was evident in control animals. Collectively, these findings demonstrate that ultrasound-mediated gene delivery to endogenous mesenchymal progenitor cells can effectively treat nonhealing bone fractures in large animals, thereby addressing a major orthopedic unmet need and offering new possibilities for clinical translation.

Concepts: DNA, Osteoporosis, Bone, Bone fracture, Developmental biology, Cell biology, Orthopedic surgery, Distraction osteogenesis

27

BACKGROUND: Instability of the second metatarsophalageal (MTP) joint is a common disorder of the forefoot and can be addressed operatively. The objective of this study was to compare a temporary K-wire fixation (tKW) to a postoperative strapping dressing (SD) after realignment surgery of second MTP instability in combination with correction of claw toe deformity. METHODS: Fifty-four consecutive patients with metatarsal index plus or neutral and a collective total of 62 operative interventions were examined at 10 years postoperatively. The operative intervention included dorsal capsulotomy, incision of the extensor hood, and lengthening of the extensor tendon. All operations were carried out at a single institution by orthopedic surgeons experienced in foot surgery. One team preferred fixation with tKW, whereas the other team used only noninvasive SD for postoperative management. The assessment included the American Orthopaedic Foot & Ankle Society (AOFAS) metatarsophalangeal-interphalangeal score as well as the visual analogue scale (VAS) for pain. Kaplan Meier analysis with recurrence of subluxation as the end point was performed, and plain radiographs of the forefoot were investigated. RESULTS: Survival without recurrence of second MTP subluxation was significantly higher in the tKW group (93%) compared with the SD group (88%) (P < .001). There was no statistical significant difference in pre- to postoperative AOFAS and VAS pain between the 2 groups. CONCLUSION: Temporary K-wire fixation had a significantly lower recurrence rate of second MTP subluxation compared with postoperative SD for postoperative alignment management in second MTP instability. LEVEL OF EVIDENCE: Level III, therapeutic study.

Concepts: Bone fracture, Surgery, Foot, Orthopedic surgery, Distraction osteogenesis, Arthroscopy, Ilizarov apparatus, Kirschner wire

27

OBJECTIVES:: To evaluate the treatment alternatives for the management of the metaphyseal tibial comminution in severe plafond fractures, and to investigate the role of the fibula fracture fixation. DESIGN:: Retrospective clinical study. SETTING:: Level-2 trauma hospital. PARTICIPANTS:: Patients with highly comminuted tibial plafond fractures. INTERVENTION:: All patients were treated with open reduction and internal fixation of the articular surface and external fixation of the metaphyseal fracture. If metaphyseal comminution was minimal, bone graft was applied and the fibular was plated (group 1); if comminution was between 1 and 3 cm, acute shortening and distraction osteogenesis was performed (group 2); and if comminution was >3 cm, distraction osteogenesis without acute shortening was performed (group 3). MAIN OUTCOME MEASUREMENTS:: Radiographic union, AOFAS ankle score. RESULTS:: Of 30 fractures, 15 fractures (50%) had an anatomic reduction of the joint. Union occurred in all but 2 fractures. Group 1 fractures healed at an average of 19 weeks (16-22). Four fractures had associated malalignment problems. The mean AOFAS score was 72.5 (range 45-100). Group 2 fractures healed at an average of 18.3 weeks (16-21). One fracture healed with 5-degrees of angulation. Group 3 fractures healed at an average of 17.5 weeks (14-24). Two fractures healed with malalignment. When groups 2 and 3 were combined to evaluate the AOFAS outcome for fractures treated with distraction osteogenesis, a score of 75.83 was obtained (45-90). There was no difference between the Group 1 versus combined Groups 2/3 with regard to this latter score (P = 0.372). Additionally, when fibula fixation (Group 1) was compared with those fractures where it was not performed (groups 2/3), no difference was seen (P = 0.276). CONCLUSIONS:: The reconstruction of severe tibial plafond fractures treated with small wire hybrid fixation may be achieved by different techniques leading to a satisfactory result. The fixation of the fibula fracture is dependent mainly on the treatment chosen for the management of the metaphyseal lesion. LEVEL OF EVIDENCE:: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Concepts: Bone, Bone fracture, Fracture, Skeletal system, Touring car racing, Orthopedic surgery, Distraction osteogenesis, External fixation

22

The magnetic intramedullary lengthening nail is an innovative technology that allows for creative ways to treat difficult problems. The lengthening option has revolutionized femur fracture management with bone loss and malunion therapy. The compression version of this nail has provided a gradual method to compress nonunions and difficult fractures that may obviate the need for many current uses of external fixation. Three cases are presented in this manuscript demonstrating a new paradigm in the management of bone loss/shortening of the tibia and femur, and recalcitrant nonunions.

Concepts: Osteoporosis, Bone, Bone fracture, Hip fracture, Fracture, Femur, Orthopedic surgery, Distraction osteogenesis

20

Bone fractures fail to heal and form nonunions in roughly 5% of cases, with little expectation of spontaneous healing thereafter. We present a systematic review and meta-analysis of published papers that describe nonunions treated with low-intensity pulsed ultrasound (LIPUS).

Concepts: Osteoporosis, Bone, Bone fracture, Fracture, Collagen, Healing, Orthopedic surgery, Distraction osteogenesis

13

The open fracture - in which the broken bone is exposed to the world outside the body - has long been a devastating injury. From the time of Hippocrates until after the American Civil War, the recommended treatment for an open fracture was amputation, with death from sepsis occurring in approximately 50% of patients. The adoption of antiseptic technique and formal surgical débridement in the late 19th century, and the introduction of antibiotic agents and improved surgical stabilization in the 20th century, all but eliminated death as an outcome. These advances, however, have not eliminated infection or nonunion, which remain . . .

Concepts: Osteoporosis, Bacteria, Bone fracture, Surgery, Orthopedic surgery, Distraction osteogenesis, American Civil War, Civil war

9

Failure of bone fracture healing occurs in 5% to 10% of all patients. Nonunion risk is associated with the severity of injury and with the surgical treatment technique, yet progression to nonunion is not fully explained by these risk factors.

Concepts: Osteoporosis, Bone, Bone fracture, Collagen, Orthopedic surgery, Distraction osteogenesis, Bone healing, Osteology

3

The operative elongation of limbs has long been a goal of orthopaedic surgeons. Indeed, the very first external skeletal fixators, although designed for stabilization of displaced fractures, were also used to overcome the posttrauma shortening that so commonly accompanies fracture deformities.

Concepts: Bone, Bone fracture, Fracture, Fracture mechanics, Orthopedic surgery, Distraction osteogenesis

3

This study is part of the Trondheim Hip Fracture Trial, where we compared free-living physical behavior in daily life 4 and 12 months following hip surgery for patients managed with comprehensive geriatric care (CGC) in a geriatric ward with those managed with orthopedic care (OC) in an orthopedic ward.

Concepts: Osteoporosis, Bone fracture, Randomized controlled trial, Hip replacement, Orthopedic surgery, Geriatrics, Distraction osteogenesis, Reconstructive surgery