Plantar-flexion tarsometatarsal joint injuries in children.

We are reporting a series of eight patients ranging in age from 3 to 10 years who sustained plantar-flexion injuries of the foot, resulting in injuries to the tarsometatarsal (TMT) interval. All injuries were identified within 3 days and treated with molded short leg immobilization. We evaluated all patients an average of 32 months after injury with physical examination and the Midfoot Functional Rating (MFR) score. Seven patients had no limitations in their activities of daily living or athletic endeavors. These seven patients had MFR scores of 100. One patient had complaints of midfoot pain with running for >5 min and radiographic evidence of degenerative changes across the TMT interval at 3-year follow-up. These results suggest that although indirect pediatric TMT injuries have a generally favorable prognosis, early degenerative changes can occur and may be responsible for chronic pain and activity limitation. Degenerative changes in this weight-bearing region in a young patient can have lifelong implications. Patients and parents may benefit from discussion of the potential for future midfoot compromise following this injury.

Abduction stress and AP weightbearing radiography of purely ligamentous injury in the tarsometatarsal joint.

Twenty volunteers (40 feet) with no prior foot injury underwent standardized abduction stress and standing AP radiographs. Subsequently, the Lisfranc and dorsal tarsometatarsal ligaments in nine feet from cadavers were sectioned in a varying sequential manner, and interval standardized radiographs of abduction stress and AP simulated weightbearing were obtained. On abduction stress radiographs in 39 of 40 feet of volunteers and nine of nine feet of cadavers before sectioning, a line tangential to the medial aspect of the navicular and medial cuneiform (medial column line) intersected the base of the first metatarsal. Combining the sectioning of the Lisfranc and dorsal tarsometatarsal ligaments produced a disruption of the medial column line in all feet from cadavers. Disruption of this medial column line may be a simple and valuable diagnostic tool for determining significant ligamentous injury to the tarsometatarsal interval.

An unusual cause of low back pain. Osteomyelitis of the spinous process.

STUDY DESIGN: A case report of osteomyelitis of the spinous process. OBJECTIVE: To describe the diagnosis and successful treatment of a patient with spinous process osteomyelitis. SUMMARY OF BACKGROUND DATA: Spinous process osteomyelitis is exceedingly rare and may be misdiagnosed as paraspinal muscle strain, discitis, or vertebral body osteomyelitis. The clinical presentation of spinous process osteomyelitis is subtle, laboratory findings are nonspecific, and radiographs are often normal. METHODS: The diagnosis, treatment, and outcome of two patients with spinous process osteomyelitis (an adult and a child) with insidious, nonspecific lumbar pain and fever are reviewed. RESULTS: Magnetic resonance imaging with and without gadolinium enhancement demonstrated increased signal of the spinous process with paraspinous musculature enhancement, a finding consistent with spinous process osteomyelitis. Biopsy results demonstrated the presence of staphylococcus aureus in the child and no organisms in the adult. Treatment with intravenous antibiotics led to resolution in both cases. CONCLUSIONS: The use of magnetic resonance imaging technology permitted the early and accurate diagnosis of spinous process osteomyelitis.

Cementless revision of total hip arthroplasty using the anatomic porous replacement revision prosthesis.

This study reports the results of revision total hip arthroplasty with the Anatomic Porous Replacement Revision Hip System (Intermedics Orthopedics, Austin, TX) to investigate the value of cementless fixation. Sixty-six hips in 65 patients were followed for a mean of 4.7 years in patients with a mean age of 56 years. Thirty-six patients were categorized as Charnley class A, 16 as class B, and 13 as class C. Forty (61%) of the femurs were classified before surgery as having loss of bone distal to the intertrochanteric line. Thirty-two (48%) of the femurs required augmentation with demineralized strut cortical allografts, 5 (8%) required bulk femoral allografts, and 12 hips (18%) required acetabular allografts. Overall, 4 stems (6%) and 2 acetabular components (4%) required further revision surgery. The reason for further revision in 1 stem and both acetabular components was allograft failure. Fifty-six (85%) hips had excellent or good Harris hip scores. Ninety percent of hips had no or slight pain, and 90% allowed patients to walk with no or slight limp. Those hips that had hydroxyapatite coating added to the porous coating had statistically improved Harris hip scores for both pain and limp. Stable fixation was present in 95% of stems. Demineralized strut grafts healed in 30 of 32 hips. Thirty-nine of 44 noncemented revision sockets had no radiolucent lines and there were no loose components. Cementless fixation was effective for these hips.

Liver hemodynamics during portal venous endotoxemia in swine.

The acute hemodynamic response of the liver to portal endotoxemia was measured in six isoflurane anesthetized pigs in which volume support was used to maintain normal cardiac output. After baseline monitoring, bacterial endotoxin (LPS) was infused over 1 hr into a mesenteric vein at a rate of 1 microgram.kg-1.hr-1, and monitoring was continued for 1 hr postinfusion. Peak vasoconstriction occurred during LPS infusion in both the hepatic artery (resistance increases 349% of baseline, P < 0.05) and the liver's portal circulation (resistance increases 159% of baseline, P < 0.05). Increased vascular resistance was also detected in lung (increases 433% of baseline) and intestine (increases 130% of baseline) at the midpoint of the LPS infusion. The non-splanchnic circulation, defined for our analysis as all of the peripheral circulation except the portal and hepatic arterial circulation, generally exhibited little change in vascular resistance during LPS infusion. LPS was incompletely cleared by the liver, but secondary clearance by the lung prevented large increases in the LPS concentration of arterial blood. During the first hour postinfusion, the systemic vascular resistance subsequently decreased to near normal in all vascular beds, with the exception of the liver's portal circulation. A sustained and secondary increase in vascular resistance of the liver's portal circulation and portal vein pressure occurred during the first hour after LPS infusion. We conclude that most of the vasoconstriction in the acute response to portal endotoxemia occurs in the liver and lung, organs directly exposed to elevated levels of endotoxins.

Effects of tensile stress on the R lines of Cr(3+) in a sapphire fiber.

We have investigated the spectroscopic properties of a crystalline sapphire fiber unintentionally doped with Cr(3+). We find that tensile stress produces blue shifts of the R lines and changes in their radiative lifetimes and integrated intensities that can be correlated to stress-induced changes of the crystal-field parameters.