Frankie Leung

Palmar Plate Fixation of AO Type C2 Fracture of Distal Radius Using a Locking Compression Plate –A Biomechanical Study in a Cadaveric Model

The stability of palmar plate fixation using a locking compression T-plate was compared with that of a conventional palmar T-plate and a dorsal T-plate in a cadaveric model of an AO type C2 fracture of distal radius. The wrist axial load transmission through the radius was tested for each fixation. The results show that, under 100N axial load, the palmar locking compression T-plate restores stability comparable to that of the intact radius, and is superior to conventional palmar or dorsal T-plates.

A prospective, randomized trial comparing the limited contact dynamic compression plate with the point contact fixator for forearm fractures.

BACKGROUND The most effective type of plate fixation for diaphyseal forearm fractures has not been defined. We performed a prospective, randomized trial in which the limited contact dynamic compression plate (LC-DCP) was compared with the Point Contact Fixator (PC-Fix) for the treatment of forearm fractures at one center. METHODS Ninety-two patients with 125 forearm fractures were recruited for the study and were randomly assigned to fracture fixation with one of the two devices. The average age of the patients was thirty-six years. The average duration of follow-up was twenty-two months. Patients were assessed periodically with use of radiographs and were assessed with regard to pain and function at time of the latest follow-up. RESULTS Three patients (four fractures) in the PC-Fix group and five patients (five fractures) in the LC-DCP group had a delayed union, but no patient in either group had a nonunion. With the numbers available, there was no significant difference between the two groups with regard to operative time, time to union, callus formation, pain, or functional outcome. Deep infection occurred in one patient with a closed fracture in the PC-Fix group and in one patient with an open fracture in the LC-DCP group. In addition, one refracture occurred in each group. Both refractures occurred at the site of a screw track. CONCLUSION Despite the differences in the concept of fracture fixation, these two implants appear to be equally effective for the treatment of diaphyseal forearm fractures.

Limited open reduction and Ilizarov external fixation in the treatment of distal tibial fractures

The authors reviewed 31 distal tibial fractures (16 involving the tibial plafond) treated with Ilizarov external fixation. The study population was composed of 19 males and 12 females, with an average age of 54. The fractures were classified according to the AO classification: A1 (3), A2 (6), A3 (6), C1 (2), C2 (8), C3 (6). There were six open injuries. In 14 pilon cases, open reduction of the intra-articular fragments and bone grafting via a limited incision was performed. Clinical follow-up averaged 28 months (range 18-42). All but one fracture united with an average healing time of 13.9 weeks. Nearly all patients with AO type A fracture had excellent or good functional scores. The 14 cases of AO C2 and C3 group had five (38%) good results, five (38%) fair results and three (24%) poor results. This method yielded results comparable with previous studies using open reduction and internal fixation. Twenty-nine percent of the patients had pin track infection, which remained the most important complication of this method.

Treatment of distal femoral fractures in the elderly using a less-invasive plating technique

We treated 16 patients having fractures of the distal femur with the less-invasive stabilization system (LISS). Patients’ mean age was 75 (62–101) years. Fifteen patients had low-energy trauma. Eight fractures were type A (AO classification), three were type B and five were type C. In two cases, loosening of the proximal fixation was seen and surgical revision performed. Union time averaged 30 (16–68) weeks. There was no non-union. Average Oxford knee score was 46 (22–60). No loosening of the distal fixation was found. LISS appears to be an effective device in treating osteoporotic distal femoral fractures.RésuméNous avons traité 16 malades présentant une fracture fémorale distale avec le Système de Stabilisation peu Invasif (LISS). L’âge moyen des malades était de 75 ans (62–101). Quinze malades avaient eu un traumatisme à basse énergie. Huit fractures étaient de type A (classification AO), trois étaient de type B, et cinq étaient de type C. Dans deux cas un démontage de la fixation proximale est survenu, avec nécessité de reprise chirurgicale. Le délai moyen de consolidation était de 30 semaines (16–68). Il n’y avait aucune non—consolidation. Le score moyen de genou Oxford était 46 (22–60). Il n’y a eut aucun démontage de la fixation distale. Le système LISS paraît être une méthode efficace pour traiter les fractures fémorales distales ostéoporotiques.

Does timing of surgery matter in fragility hip fractures

The effect of delay of surgery on the geriatric hip fractures has been a subject of interest in the past two decades. While the elderly patients will not tolerate long periods of immobilization, it is still unclear how soon these surgeries need to be performed. A review of existing literature was performed to examine the effect of timing of surgery on the different outcome parameters of these patients. Although there is conflicting evidence that early surgery would improve mortality, there is widespread evidence in the literature that other outcomes including morbidity, the incidence of pressure sores, and the length of hospital stay could be improved by shortening the waiting time of hip fracture surgery. We concluded that it is beneficial to the elderly patients to receive surgical treatment as an urgent procedure as soon as the body meets the basic anesthetic requirements.

In vivo stimulation of bone formation by aluminum and oxygen plasma surface-modified magnesium implants

A newly developed magnesium implant is used to stimulate bone formation in vivo. The magnesium implant after undergoing dual aluminum and oxygen plasma implantation is able to suppress rapid corrosion, leaching of magnesium ions, as well as hydrogen gas release from the biodegradable alloy in simulated body fluid (SBF). No released aluminum is detected from the SBF extract and enhanced corrosion resistance properties are confirmed by electrochemical tests. In vitro studies reveal enhanced growth of GFP mouse osteoblasts on the aluminum oxide coated sample, but not on the untreated sample. In addition to that a small amount (50 ppm) of magnesium ions can enhance osteogenic differentiation as reported previously, our present data show a low concentration of hydrogen can give rise to the same effect. To compare the bone volume change between the plasma-treated magnesium implant and untreated control, micro-computed tomography is performed and the plasma-treated implant is found to induce significant new bone formation adjacent to the implant from day 1 until the end of the animal study. On the contrary, bone loss is observed during the first week post-operation from the untreated magnesium sample. Owing to the protection offered by the Al2O3 layer, the plasma-treated implant degrades more slowly and the small amount of released magnesium ions stimulate new bone formation locally as revealed by histological analyses. Scanning electron microscopy discloses that the Al2O3 layer at the bone-implant interface is still present two months after implantation. In addition, no inflammation or tissue necrosis is observed from both treated and untreated implants. These promising results suggest that the plasma-treated magnesium implant can stimulate bone formation in vivo in a minimal invasive way and without causing post-operative complications.

Enhanced gene delivery by chitosan-disulfide-conjugated LMW-PEI for facilitating osteogenic differentiation

Chitosan-disulfide-conjugated LMW-PEI (CS-ss-PEI) was designed to combine the biocompatibility of chitosan and the gene delivery ability of polyethylenimine (PEI) using bio-reducible disulfide for bone morphogenetic protein (BMP2) gene delivery in mediating osteogenic differentiation. It was prepared by conjugating low molecular weight PEI (LMW-PEI) to chitosan through oxidization of thiols introduced for the formation of disulfide linkage. The structure, molecular weight and buffer capacity were characterized by Fourier transform infrared (FTIR), light scattering and acid-base titration, respectively. The reduction in molecular weight of CS-ss-PEI by the reducing agent indicated its bio-reducible property. With the increment in the LMW-PEI component, the copolymer showed increased DNA binding ability and formed denser nanocomplexes. CS-ss-PEI exhibited low cytotoxicity in COS-1, HepG2 and 293T cells over the different weight ratios. The transfection efficiency of CS-ss-PEI4 was significantly higher than that of PEI 25k and comparable with Lipofectamine in mediating luciferase expression. Its application for BMP2 gene delivery was confirmed in C2C12 cells by BMP2 expression. For inducing in vitro osteogenic differentiation, CS-ss-PEI4 mediated BMP2 gene delivery showed a stronger effect in MG-63 osteoblast cells and stem cells in terms of alkaline phosphatase activity and mineralization compared with PEI25k and Lipofectamine. This study provides a potential gene delivery system for orthopedic-related disease.

The Effectiveness of a Geriatric Hip Fracture Clinical Pathway in Reducing Hospital and Rehabilitation Length of Stay and Improving Short-Term Mortality Rates

Background: A geriatric hip fracture clinical pathway, led by an orthopedic surgeon, was developed in 2007. This clinical pathway team is multidisciplinary and consists of surgeons, physicians, anesthetists, nurses, physiotherapists, occupational therapists, medical social workers, dieticians as well as voluntary support groups. Methods: From early 2007 onward, all patients older than 65 years with acute isolated hip fractures were included. During the whole inpatient treatment, all relevant data were captured prospectively. The data in 2006, before the implementation of the clinical pathway, were collected retrospectively through computer record system. A study of the length of stay in acute and rehabilitation hospital and also the short-term mortality rate was carried out to compare the difference before and after the implementation of the pathway. Results: From 2007 onward, more than 1300 hip fractures were treated. After the implementation of the pathway, the preoperative length of stay was markedly shortened by 4 days, from an average of 6.1 days in 2006 to 1.5 days in 2011 (P < .05). The postoperative length of stay and the overall acute hospital length of stay also improved significantly. The length of stay in rehabilitation hospital was also significantly shorter in the 4-year period. Although the number of hip fractures increased annually with increased age and number of comorbidities each year, the inpatient mortality rate showed a gradual decrease from 2.7% in 2006 to 1.25% in 2010. The 30 days mortality rate also showed a decrease from 3.65% in 2006 to 2.75% in 2010. Conclusion: Geriatric hip fracture clinical pathway is an excellent approach to the geriatric hip fracture service. The most significant improvement is the dramatic shortening of the length of hospital stay. Our success in the past 5 years has proven its value and sustainability.

Masquelet Technique for Treatment of Posttraumatic Bone Defects

Masquelet technique, which is the use of a temporary cement spacer followed by staged bone grafting, is a recent treatment strategy to manage a posttraumatic bone defect. This paper describes a series of 9 patients treated with this technique of staged bone grafting following placement of an antibiotic spacer to successfully manage osseous long bone defects. The injured limbs were stabilized and aligned at the time of initial spacer placement. In our series, osseous consolidation was successfully achieved in all cases. This technique gives promising result in the management of posttraumatic bone defects.

Occult posterior pelvic ring fractures in elderly patients with osteoporotic pubic rami fractures

Purpose. To evaluate postoperative walking status of elderly patients with osteoporotic pubic rami fractures with or without posterior pelvic ring fractures. Methods. 33 women and 4 men aged 66 to 95 (mean, 85) years presented with osteoporotic pubic rami fractures after a fall. 22 (59%) of the patients had additional posterior pelvic ring fractures (9 had lateral compression type-II fractures involving the ilium and 13 had lateral compression type-I fractures involving the sacroalar region). Seven of the 9 patients with lateral compression type-II fractures underwent open reduction and internal fixation using plates and/or screws. The remaining 30 patients were treated conservatively. Results. Postoperative walking status was similar in elderly patients with osteoporotic pubic rami fractures with or without posterior pelvic ring fractures. Conclusion. Posterior pelvic ring fractures are easily missed in elderly patients with pubic rami fractures. Routine computed tomography of the pelvis is useful in making the diagnosis.