A comparison of two approaches for the closed treatment of low-energy tibial fractures in children.

BACKGROUND: Many orthopaedic surgeons treat tibial shaft fractures in children with a period of non-weight-bearing after application of a long leg cast, presumably to prevent fracture angulation and shortening. We hypothesized that allowing children to immediately bear weight as tolerated in a cast with the knee in 10° of flexion would lessen disability, without increasing the risk of unacceptable shortening or angulation. METHODS: We divided eighty-one children, between the ages of four and fourteen years, with a low-energy, closed tibial shaft fracture into two groups. One group (forty children) received a long leg cast with the knee flexed 60° and were asked not to bear weight. The second group (forty-one children) received a long leg cast with the knee flexed 10° and were encouraged to bear weight as tolerated. All patients were switched to short leg walking casts at four weeks. We compared time to healing, overall alignment, shortening, and physical disability as determined by the Activities Scale for Kids-Performance (ASK-P) questionnaire. RESULTS: The mean time to fracture union was 10.8 weeks in both groups (p = 0.47). At the time of healing, mean coronal alignment was within 1.3° in both groups, mean sagittal alignment was within 1°, and mean shortening was <0.5 mm, with no significant differences. The ASK-P scores showed that both groups had overall improvement in physical functioning over time. However, at six weeks, the children who were allowed to bear weight as tolerated had better overall scores (p = 0.03) and better standing skills (p = 0.01) than those who were initially instructed to be non-weight-bearing. CONCLUSIONS: Children with low-energy tibial shaft fractures can be successfully managed by immobilizing the knee in 10° of flexion and encouraging early weight-bearing, without affecting the time to union or increasing the risk of angulation and shortening at the fracture site.

The suitability of human adipose-derived stem cells for the engineering of ligament tissue.

Rupture of the anterior cruciate ligament (ACL) is the one of the most common sports-related injuries. With its poor healing capacity, surgical reconstruction using either autografts or allografts is currently required to restore function. However, serious complications are associated with graft reconstructions and the number of such reconstructions has steadily risen over the years, necessitating the search for an alternative approach to ACL repair. Such an approach may likely be tissue engineering. Recent engineering approaches using ligament-derived fibroblasts have been promising, but the slow growth rate of such fibroblasts in vitro may limit their practical application. More promising results are being achieved using bone marrow mesenchymal stem cells (MSCs). The adipose-derived stem cell (ASC) is often proposed as an alternative choice to the MSC and, as such, may be a suitable stem cell for ligament engineering. However, the use of ASCs in ligament engineering still remains relatively unexplored. Therefore, in this study, the potential use of human ASCs in ligament tissue engineering was initially explored by examining their ability to express several ligament markers under growth factor treatment. ASC populations treated for up to 4 weeks with TGFß1 or IGF1 did not show any significant and consistent upregulation in the expression of collagen types 1 and 3, tenascin C and scleraxis. While treatment with EGF or bFGF resulted in increased tenascin C expression, increased expression of collagens 1 and 3 were never observed. Therefore, simple in vitro treatment of human ASC populations with growth factors may not stimulate their ligament differentiative potential.

Complication rates following open reduction and internal fixation of ankle fractures.

BACKGROUND: Ankle fractures are among the most common injuries treated by orthopaedic surgeons. The purpose of the present investigation was to examine the risks of complications after open reduction and internal fixation of ankle fractures in a large population-based study. METHODS: With use of California's discharge database, we identified 57,183 patients who had undergone open reduction and internal fixation of a lateral malleolar, bimalleolar, or trimalleolar ankle fracture as inpatients in the years 1995 through 2005. Short-term complications were examined on the basis of the rates of readmission within ninety days after discharge. The intermediate-term rate of reoperation for ankle fusion or arthroplasty was also analyzed. Logistic regression and proportional hazard regression models were used to determine the strength of the relationships between the rates of complications and fracture type, patient demographics and comorbidities, and hospital characteristics. RESULTS: The overall rate of short-term complications was low, including the rates of pulmonary embolism (0.34%), mortality (1.07%), wound infection (1.44%), amputation (0.16%), and revision open reduction and internal fixation (0.82%). The intermediate-term rates of reoperation were also low, with ankle fusion or ankle replacement being performed in 0.96% of the patients who were observed for five years. Open fractures, age, and medical comorbidities were significant predictors of short-term complications. The presence of complicated diabetes was a particularly strong predictor (odds ratio, 2.30; p < 0.001), as was peripheral vascular disease (odds ratio, 1.65; p < 0.001). The intermediate-term rate of reoperation for ankle fusion or replacement was higher in patients with trimalleolar fractures (hazard ratio, 2.07; p < 0.001) and open fractures (hazard ratio, 5.29; p < 0.001). Treatment at a low-volume hospital was not significantly associated with either the aggregate risk of short-term complications or the risk of intermediate-term reoperation. CONCLUSIONS: By analyzing a large, diverse patient population, the present study clarifies the risks associated with open reduction and internal fixation of ankle fractures. Open injury, diabetes, and peripheral vascular disease were strong risk factors predicting a complicated short-term postoperative course. Fracture type was a strong predictor of reoperation for ankle fusion or replacement. Hospital volume did not play a significant role in the rates of short-term or intermediate-term complications.

Biology of allograft incorporation.

The use of implantation of allograft tissue in sports medicine has risen steadily over the last decade. Allograft tissues offer several advantages over autografts, including reduced donor-site morbidity and decreased operative time, and in some instances, no autograft option exists. However, with allografts, there is a small risk of disease transmission, immunologic rejection, and decreased biologic incorporation. Several techniques to limit these pitfalls and maximize graft incorporation are available, however. This chapter takes an in-depth look at the biology of allograft incorporation and how these techniques affect graft incorporation.