Stabbing the anterolateral anulus fibrosus of adult rabbit lumbar discs with a 16-gauge hypodermic needle to a limited (5-mm) depth results in a number of slowly progressive and reproducible magnetic resonance imaging, radiograph, and histologic changes over 24 weeks that show a similarity to changes seen in human intervertebral disc degeneration. This model would appear suitable for studying pathogenesis and pathophysiology of intervertebral disc degeneration and testing safety and efficacy of novel treatments of intervertebral disc degeneration.

The proportion of fractures that occur in women without osteoporosis has not been fully described, and the characteristics of nonosteoporotic women who fracture are not well understood. We measured total hip bone mineral density (BMD) and baseline characteristics including physical activity, falls, and strength for 8065 women aged 65 yr or older participating in the Study of Osteoporotic Fractures and then followed these women for hip fracture for up to 5 yr after BMD measurement. Among all participants, 17% had osteoporosis (total hip BMD T-score < or = -2.5). Of the 243 women with incident hip fracture, 54% were not osteoporotic at start of follow-up. Nonosteoporotic women who fractured were less likely than osteoporotic women with fracture to have baseline characteristics associated with frailty. Nevertheless, among nonosteoporotic participants, several characteristics increased fracture risk, including advancing age, lack of exercise in the last year, reduced visual contrast sensitivity, falls in the last year, prevalent vertebral fracture, and lower total hip BMD. These findings call attention to the many older women who suffer hip fracture but do not have particularly low antecedent BMD measures and help begin to identify risk factors associated with higher bone density levels.

This retrospective study investigated outcomes of wound healing in a series of 63 consecutive patients with 64 fractures of the calcaneus who underwent open reduction and internal fixation done by two surgeons experienced in this fracture during a 3-year period. Thirty-nine patients were managed preoperatively as outpatient referrals before surgery. Twenty-four patients were admitted directly to the trauma service and were managed as inpatients preoperatively. Minimum patient follow-up was 6 months, with an average follow-up of 18 months. A trend correlating the time between injury and operative intervention with the incidence of complications in wounds was noted; the incidence rose in patients who underwent surgery >5 days after their injury. Two-layered closures had a lower incidence of dehiscence compared to single-layered tension-relieving sutures. Patients with a higher body-mass index (BMI) (kg/ m2) took longer to heal their wounds. Strong trends were noted to link BMI and severity of fractures. In the outpatient group, a history of active smoking preoperatively correlated with increased time to wound healing. In 43 patients, there were no wound-healing complications. In 21 feet, there were varying degrees of wound dehiscence. Average wound healing took 47 days. Risk factors for complications in the wound after calcaneal open reduction and internal fixation include single layered closure, high BMI, extended time between injury and surgery, and smoking. Age, type of immobilization, medical illness (including diabetes), type of bone graft, or use of a Hemovac did not influence wound healing.

No abstract

Injury to muscles is very common. We have previously observed that basic fibroblast growth factor (b-FGF), insulin growth factor type 1 (IGF-1) and nerve growth factor (NGF) are potent stimulators of the proliferation and fusion of myoblasts in vitro. We therefore injected these growth factors into mice with lacerations of the gastrocnemius muscle. The muscle regeneration was evaluated at one week by histological staining and quantitative histology. Muscle healing was assessed histologically and the contractile properties were measured one month after injury.Our findings showed that b-FGF, IGF and to a less extent NGF enhanced muscle regeneration in vivo compared with control muscle. At one month, muscles treated with IGF-1 and b-FGF showed improved healing and significantly increased fast-twitch and tetanus strengths. Our results suggest that b-FGF and IGF-1 stimulated muscle healing and may have a considerable effect on the treatment of muscle injuries.