Kümmells disease is defined as delayed post-traumatic vertebral collapse, common in osteoporotic people with/without a trauma history. Its clinical course is progressive, and treatment modalities have to be tailored to the patient. In the literature, no staging system has been reported. Based on clinical symptomatology, radiographic and MRI imaging, a staging system for Kümmells disease was developed. This study involved 129 Kümmells disease patients with 348 compression fractures involving 136 vertebrae. The mean age was 72.5 ± 6.6 years, with a female to male ratio of 103 to 26. Osteoporosis is a common risk factor. Minor trauma can be traced in some of the patients. A three-stage system was proposed. Stage I: Intact or minor compression on plain X-ray films with signs of osteonecrosis on the MRI. Stage II: Body collapse with dynamic mobility, but with intact posterior body wall. Stage III: Collapse of posterior body wall with resultant cord compression. There were 19, 90 and 33 vertebrae respectively classified in Stages I, II and III. Kümmells disease is most common threat to the thoracolumbar junction. Treatments based on clinical symptomatology and radiographic findings were well correlated with the staging system. The present staging system therefore seems appropriate to describe the natural course of Kümmells disease and to guide management policy.

High fat-sucrose (HFS) diets can reportedly produce glucose intolerance and hyperinsulinemia that may indirectly have deleterious effects on bone. The effects of a high-fat diet on calcium absorption, bone calcium content, and bone mechanical properties, however, remain controversial. Thus, we examined the morphological and biomechanical adaptations in limb bones of rats that were fed a HFS diet. Female Sprague-Dawley rats (8 weeks old) were randomly assigned to two groups, either a control group (n = 9) fed a standard diet (low-fat complex-carbohydrate) or an experimental group (n = 9) fed a HFS diet for 10 weeks. The right tibia and second metatarsus (MT) were fractured in three-point bending, and contralateral bones were used for morphological and histological analyses. HFS tibias had significantly lower maximum load and failure energy, and tensile stress at the proportional limit for both HFS tibia and MT was significantly less than controls. In addition, the elastic modulus and density of the HFS MT was significantly lower than controls. Geometry of the tibial mid-diaphysial cross section did not differ for the two diets, but the cortical cross-sectional area of HFS MT increased significantly compared to control MT. The total number of osteons in the mid-diaphysis of HFS MT decreased, but tibial and MT porosities did not change with the HFS diet. Our results suggest that the deleterious effects of the HFS diet may be more related to changes in the material properties of the cortical bone rather than to osteoporotic changes in the bone.

We examined the influence of a strenuous exercise regimen on tibial and metatarsal bones to show not only how the geometric, histological, and mechanical properties of immature bone respond to strenuous exercise but also how long bones within the same limb may respond differentially to exercise. Female Sprague-Dawley rats (8 wk old) were divided randomly into two groups: a sedentary control (n = 15) and an exercised group (n = 15). The exercise intensity was 80-90% of maximum oxygen capacity 5 days/wk for 10 wk. Mechanical properties of tibia and second metatarsus (MT) were determined with three-point bending, and contralateral bones were used for geometric and histological analyses. Length and middiaphyseal cross-sectional geometry of the exercised tibiae were significantly less than controls, but material properties were not different. The exercised tibiae had significantly lower structural properties (e.g., loads at the proportional limit and maximum and energy at failure load). The middiaphyseal dorsal cortex of exercised MT was significantly thicker than controls, but tensile stress at the proportional limit and elastic modulus of exercised MT were significantly less than controls. The average number of osteons and osteocytes per unit area of the tibial middiaphysis was significantly greater in the exercised group--especially in lateral and posterior cortices. The number of osteons and osteocytes per unit area in the MT, however, was significantly less in the exercised group. The differential effects of strenuous exercise on tibia and MT suggest that local loading and bone-specific responses have important roles in modulating the response of immature bone to strenuous exercise.

Background:Short-segment fixation alone to treat thoracolumbar burst fractures is common but it has a 20-50% incidence of implant failure and rekyphosis. A transpedicle body augmenter (TpBA) to reinforce the vertebral body via posterior approach has been reported to prevent implant failure and increase the clinical success rate in treating burst fracture. This article is to evaluate the longterm results of short-segment fixation with TpBA for treatment of thoracolumbar burst fractures.Materials and Methods:Patients included in the study had a single-level burst fracture involving T11-L2 and no distraction or rotation element with limited neurological deficit. Patients in the control group (n = 42) were treated with short-segment posterior instrumentation alone, whereas patients in the augmented group (n = 90) were treated with a titanium spacer designed for transpedicle body reconstruction. The followup was 48-101 months. The radiographic and clinical results were evaluated and compared by Student's t test and Fisher's exact test.Results:The blood loss, operation time and hospitalization were similar in both the groups. The immediate postoperative anterior vertebral restoration rate of the augmented group was similar to that of the control group (97.6% ± 2.4% vs. 96.6% ± 3.2%). The final anterior vertebral restoration was greater in the augmented group than in the control group (93.3% ± 3.4% vs. 62.5% ± 11.2%). Immediate postoperative kyphotic angles were not significantly different between the groups (3.0° ± 1.8° vs. 5.1° ± 2.3°). The final kyphotic angles were less in the augmented group than the control group (7.3° ± 3.5° vs. 20.1° ± 5.4°). The augmented group had less (P < 0.001) implant failure [0% (n=0) vs. 23.8% (n=10)] for the control group) and more patients (P < 0.001) with no pain or minimal or occasional pain (Grade P1 or P2) than the control group [90.0% (n=81) vs. 66.7% (n=28)]. All patients in the augmented group and 39 (92.8%) patients in the control group experienced neurological recovery to Frankel Grade E. Three patients in the control group had improvement to Frankel Grade D from Frankel Grade C, but later had deterioration to Frankel Grade C because of loosening and dislodgement of the implant.Conclusion:Posterior body reconstruction with TpBA can maintain kyphosis correction and vertebral restoration, prevent implant failure and lead to better clinical results.

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