Journal of Musculoskeletal Research

Systematic studies of treatment options for femoral head osteonecrosis have been hindered by the lack of an animal model that mimics the human event of femoral head collapse. The (bipedal) emu model of osteonecrosis has proven to progress to collapse following an external insult. Since osteonecrosis clinically has multiple etiologies, various alternatives are seemingly appropriate to initiate lesions for research purposes. This study compared osteonecrosis initiated by a local cryoinsult, to that initiated by a large systemic dose of steroid (methylprednisolone acetate), and by a combination of steroid and cryoinsult. One year post-insult, the animals were sacrificed and their femoral heads harvested. A custom-written computer program was used to expedite analysis of the global distribution of histologically apparent osteonecrosis, as determined by the Ficat scale. Following whole-head analysis, grade distributions were calculated, and a measure of spatial clustering of histologic abnormality was calculated using Moran's I statistic. Normal femoral heads showed very small amounts of histological abnormality, and no significant spatial clustering. Femoral heads receiving isolated cryoinsult had a greater incidence of high-grade abnormality, as well as statistically significant spatial clustering of that abnormality. Steroid-only animals had a higher percentage of diffuse, low-grade abnormality. The group receiving both steroid and cryoinsult showed the highest overall abnormality, with statistically significant clustering of that high-grade abnormality. Cryoinsult, both in isolation and in combination with a steroid regimen, appeared necessary to mimic the clinically typical focal lesions of osteonecrosis.

There have been several pathologic descriptions of the spinal cord compressed chronically. Microglial changes, however, have been described scarcely. In the present study, microglial responses to the anterior unilateral compression were investigated by immunohistochemistry in the rabbit model. The cervical spinal cord was unilaterally compressed with a small screw at C5. The microglial response in the compressed and the contralateral halves of the spinal cord were investigated after 48 hours with the lectin RCA-1 immunostaining. Microglia were classified morphologically into resting and reactive microglia. Under mild compression, the mild proliferation of reactive microglia was observed in the anterior horn of the compressed half. A few reactive microglia were observed in the anterior horn of the contralateral half. The total number of resting and reactive microglia in each area of the gray and white matters did not differ between the sham and mild compression groups. Under severe compression, marked proliferation of reactive microglia was observed around the cavity in the gray matter of the compressed half. Moderate proliferation of reactive microglia was observed in gray matter of the contralateral half. These findings suggested that the resting microglia transformed into the reactive microglia, but not proliferated in the early stage of compression myelopathy.

The purpose is to examine the importance of ipsilateral leg strength in mediating hip fracture disability. Leg strength measures were recorded and analyzed for 4 separate data sets: (1) 35 patients hospitalized for acute hip fractures; (2) 72 hip replacement surgical candidates with prior hip fracture histories; (3) 30 hip fracture patients followed prospectively for six months after hospital discharge; (4) 23 hip fracture cases interviewed two years after hospital discharge. (1) 78% of patients with acute hip fracture exhibited leg weakness on the injured side, and 41% exhibited knee extensor muscle weakness on the injured side; (2) 79% of patients readmitted for hip surgery, had deficient muscle power of the previously fractured leg and 33% had specific evidence of knee extensor weakness; (3) Interlimb knee extensor strength differentials greater than 10%, more commonly due to strength deficits on the injured side than the uninjured side, were present in 80% of cases examined six months post surgery, and affected walking speed. (4) knee extensor strength of the affected leg predicted the subject's walking speed, as did leg strength two years post surgery. The conclusion is that knee extensor strength deficits of the affected leg are common features of hip fracture patients, and may contribute to, or perpetuate, functional disability.

It is well known that the coagulation factor XIII (FXIII) is deeply involved in wound healing and tissue regeneration. We measured the plasma levels of FXIII (FXIII levels) before and after surgery in 80 patients with bone tumors [benign tumors in 30 patients (BT group), malignant tumors in 30 patients (MT group), and carcinoma metastasis in 20 patients (CM group)] and in the control group which consisted of 30 patients with osteoarthritis of the hip joint who had underwent total hip arthroplasty (THA). The numbers of patients whose preoperative FXIII level was below the lower limit of normal were as follows: 0 (0%) among 30 patients in the control group; 7 (23%) among 30 patients in the BT group; 12 (40%) among 30 patients in the MT group; and 9 (45%) among 20 patients in the CM group. Among patients with bone tumors examined in this study, patients with osteosarcoma who underwent chemotherapy showed a significant decrease in FXIII levels (p < 0.01). We indicated not only FXIII levels in patients with bone tumors, but also the natural time-course of FXIII levels in patients who underwent orthpaedic surgery of THA at the first time.

Since most of our current knowledge about the concept of bone gain during adolescence or early adulthood comes from the cross-sectional studies, we aimed to evaluate natural course of changes in bone mineral density prospectively during early adulthood in a cohort. Twenty-two volunteers (15 female, 7 male) with the mean age of 20.0 ± 0.69 years were enrolled into the study. Subjects with any known secondary cause of osteoporosis were excluded from the study. Demographic variables, anthropometric measurements were recorded. Subjects underwent an interview about risk factors for osteoporosis. Physical activity level and calcium intake were evaluated by European Vertebral Osteoporosis Study questionnaire. Lumbar and femoral bone mineral densities were measured using Dual Energy X-ray Absorptiometry (DXA) at baseline and two years after. L1-4 BMD increased from 0.925 ± 0.099 g/cm² to 0.957 ± 0.094 g/cm²(p = 0.002) and total femur BMD increased from 0.866 ± 0.113g/cm² to 0.908 ± 0.108g/cm²(p = 0.0001). BMC of L1-4 increased significantly (p = 0.022), however there was no change in bone area measurements (p = 0.82). In case of femoral total measurements, both BMC and bone area demonstrated significant increase over the study period (p = 0.0001 and p = 0.0001). There were significant positive differences in bone mineral densities for L3, L4 measurements in males and for L3 measurements in females (p = 0.028, p = 0.018 and p = 0.02 respectively). Different from the bone gain during adolescent years which is usually attributed to volumetric expansion of the bones; we were able to demonstrate that bone gain continues through early years of adulthood. It would be rational to extend preventive measures beyond adolescence, into early adulthood to optimize the bone mass.

The efficiency of ultrasound usage in the diagnosis of the painful calf has been discussed in previous reports. We report our experience with the use of this modality as an accurate diagnostic tool for calf pain in young adults. Twenty-nine patients (16 males, 13 females) underwent dynamic ultrasonographic examination due to calf pain. Nine patients had tears of the gastrocnemius medial head, 2 had an intramuscular haematoma, 2 had distal fibula fractures, 3 had peroneal muscle herniation and 2 had herniation of the gastrocnemius medial head. One patient had cellulitis, one polymyositis and one dermatomyositis. Two patients had myositis ossificans, 2 patients had haemangiomas, and 4 patients had lipomas. All the diagnoses were confirmed by other imaging modalities and/or histological evaluation. We found ultrasound, as a very helpful tool to achieve a correct diagnosis of the painful calf.