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S Martinez

Publications and source records attributed to S Martinez.

190 records · Page 11Linked to original sources
PubMedDate not supplied

Dynamic contrast-enhanced MR imaging assessment of vascularized free fibular grafts.

Magnetic resonance (MR) imaging may be a noninvasive method for assessing perfusion of vascularized bone grafts placed for treatment of avascular necrosis. One proximal femur of seven beagles was devascularized, with insertion of a vascularized fibular graft. MR imaging at 1 week (seven dogs) and 6 weeks (five dogs) after surgery included pre- and postcontrast spin-echo sequences, unenhanced two-dimensional time-of-flight (TOF) vascular imaging, and dynamic gradient-echo imaging during infusion of gadolinium. Relative signal intensity values of selected regions obtained from the dynamic gradient-echo images were plotted as percent enhancement versus time. In the operated hip, MR imaging did not show enhancement in six of seven femoral heads and greater trochanters at 1 week after surgery, with similar results after 6 weeks. MR imaging of fibular grafts 6 weeks after surgery showed an initial rapid increase in enhancement and a subsequent slower increase in five of five dogs, although no enhancement was seen in six of seven dogs at 1 week. These findings contrasted with a rapid initial increase in enhancement followed by slow decline in non-operated hips. Two-dimensional TOF imaging did not show the vascular pedicle of the graft in any dog. Findings of radionuclide bone scanning performed 1 week after surgery were consistent with devascularization of the operated femur and fibular graft. However, tetracycline distribution and histologic findings confirmed the viability of five of five grafts within the devascularized femurs 6 weeks after surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

An unusual presentation of thyroid papillary carcinoma: enlargement of a cervical intervertebral foramen.

Isolated enlargement of the cervical intervertebral foramen is frequently associated with dumbbell neurogenic tumors. We present an unusual case of isolated enlargement of a cervical intervertebral foramen in a 77-year-old male with an aggressive papillary thyroid carcinoma. To our knowledge, this represents the first case describing a thyroid process as a cause of foraminal enlargement.

Aged↗
PubMedDate not supplied

Computed tomography of the normal patellofemoral joint.

Radiographic assessment of the patellofemoral joint (PFJ) is problematic because conventional views are cumbersome, difficult to standardize, and not reliable for displaying this joint with flexion of the knee less than about 30 degrees. We used computed tomography (CT) to obtain conveniently a direct transaxial view of the PFJ in ten normal human volunteers at different 0 degree, 20 degrees, and 45 degrees of knee flexion and during both contraction and relaxation of the quadriceps muscle. From the CT images we measured femoral trochlear angle, patellar centralization, femoral trochlear depth, and patella tilt angle. In full extension, with the quadriceps muscle relaxed, 19 of 20 knees showed the patella well centered in the femoral trochlear groove. The tilt and centralization of the patella were largely unchanged at 20 and 45 degrees of knee flexion with quadriceps contraction. CT appears to be an optimal method of studying the PFJ. The normal relationships described in this report can be the basis for evaluating patients with known or suspicious history of recurrent subluxation or dislocation of the patella.

Adult↗
PubMedDate not supplied

An explanation for various rectus femoris strain injuries using previously undescribed muscle architecture.

We performed cadaveric dissection of the rectus femoris muscle to correlate the various lesions of strain injury seen with imaging studies to the muscular anatomy. The proximal tendon is composed of a superficial, anterior portion from the direct head, and a deep intramuscular portion from the indirect head. The muscle fibers arising from the anterior superficial tendon of the direct head travel in a posterior and distal direction to insert on the posterior tendon of insertion, giving the proximal muscle a unipennate architecture. Muscle fibers from the intramuscular tendon of the indirect head originate on both the medial and lateral sides of the tendon and insert on the distal posterior tendon to create its bipennate structure. Three chronic strain injuries involving the midmuscle belly substance were explored grossly and microscopically. It appears that one type of acute strain injury occurs in the midmuscle belly with disruption of the muscle-tendon junction of the intramuscular tendon resulting in local hemorrhage and edema. More chronically, this hematoma organizes into a fatty, loose connective tissue encasement of the deep intramuscular proximal tendon. Serous fluid from the hematoma may remain within the connective tissue sheath, creating a pseudocyst with the deep intramuscular tendon of the indirect head at its center. The muscle's anatomy helps to explain a different rectus femoris strain injury.

Athletic Injuries↗
PubMedDate not supplied

Incomplete, intrasubstance strain injuries of the rectus femoris muscle.

Rectus femoris muscle strain injuries commonly occur at the distal muscle-tendon junction of the quadriceps tendon. However, we have recently recognized a pattern of strain injury that consists of an incomplete intrasubstance tear at the muscle-tendon junction formed by the deep tendon of the muscle's indirect head and those muscle fibers originating from this tendon. These injuries are found more proximally within the thigh than the "classic" distal rectus femoris muscle strain. We reviewed 10 athletes with these intrasubstance tears, all of whom had diagnostic imaging performed using computed tomography or magnetic resonance imaging or both. Two of these patients required surgical intervention. The mechanism of injury usually involved kicking or sprinting. All patients had chronic thigh pain or an anterior thigh mass or both. Physical examination revealed thigh asymmetry and a nontender to mildly tender intrasubstance muscle mass. Magnetic resonance imaging demonstrated abnormal signal intensity centered about the intramuscular tendon of the indirect head of the muscle. Surgical findings included a mass of fibrous scar and fatty tissue encasing the deep tendon. Surgical removal of this fibrous mass appears curative. We contrast this injury from distal strains of the rectus femoris muscle, as well as from soft tissue neoplasms.

Adolescent↗
PubMedDate not supplied

Simultaneous pulmonary leiomyosarcoma and leiomyoma in pediatric HIV infection.

The case of a 7-year-old girl with acquired immunodeficiency syndrome treated for 5 years with AZT and intravenous gamma globulin is reported. Shortly before her demise she developed a pulmonary leiomyosarcoma and leiomyoma. Does prolonged survival in pediatric acquired immune deficiency syndrome increase the incidence of secondary malignancies?

Child↗