Biomedical subjects
Publications and source records attributed to T A Lange.
Magnetic resonance imaging was performed as a preoperative examination in three children with neurofibromatosis and soft-tissue plexiform neurofibromas. In all three patients, MRI showed more widespread soft tissue involvement than was suspected clinically including extension towards the spine in each case. Patient management was changed in each case after MRI was performed.
A soft-tissue mass in an extremity may present a diagnostic dilemma for the evaluating surgeon. A decision either to observe or remove the mass is required. An algorithm can assist in the decision-making process. A careful history may aid in determining the etiology. A history of thigh-muscle trauma, for instance, may suggest myositis ossificans as the diagnosis of a malignant soft-tissue tumor. A large, firm mass that is fixed to deep structures or located within muscle should prompt the following studies: (1) plain radiographs of the extremity; (2) an ultrasound study of the mass; and (3) a three-phase technetium 99m methylene diphosphonate bone scan.
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Ceramic tricalcium phosphate (TCP) has been implanted in bony defects in 43 patients following trauma. It is an osteoconductive material that facilitates trabecular bone formation. The average follow-up time was 12 months, with a 6-month minimum. There were 33 fractures in 30 patients and 13 nonunions in 13 patients. Three of the patients with acute fractures were unavailable for follow-up observation. Ninety percent of the fractures and 85% of the nonunions were healed at the time of this review. The resorption of TCP was estimated from the roentgenograms to be approximately 10% per month, with complete resorption occurring in 6-24 months. There were eight complications, five among the 30 fractures and three among the 13 nonunions that were observed later. There were three fractures and two nonunions that failed to heal. There were two fractures that had initially been open and one previously infected nonunion that united but were complicated due to infection. These preliminary results demonstrate TCP's usefulness as a substitute for cancellous bone. This is accompanied by other advantages, including increased patient safety, lack of donor site morbidity, unlimited shelf life and reduced operating time.
Seven patients with malignant soft tissue tumors of the foot and ankle were retrospectively reviewed. Emphasis was placed on the value of various diagnostic modalities used preoperatively for staging and the adequacy of treatment rendered using current tumor surgery principles. The malignant tumors included synovial cell sarcoma (four), clear cell sarcoma (one), fibrosarcoma (one), and melanoma (one). Surgical management of the malignant lesions included intracapsular excision, marginal excision, wide excision, and radical amputation. Preoperative diagnostic and staging studies that were found to be helpful include ultrasonography, xeroradiography, triple-phase bone scan, and CT and magnetic resonance imaging (MRI) scans. Surgical guidelines include the use of longitudinal skin incisions to obtain excisional biopsies of smaller lesions, keeping the tourniquet inflated until either a benign diagnosis is made or until the definitive procedure is performed. Wide excision or partial foot versus radical amputation may be required depending on the size, location, and extent of malignant soft tissue sarcomas.
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Forty-two soft tissue masses in infants and children were examined with high resolution ultrasonography. Sonography was diagnostically specific in 17/42 (40%), useful but not diagnostic in 24/42 (58%), and misleading in 1/42 (2%) of soft tissue masses. Lesions with diagnostic sonographic features included cystic hygroma, fibromatosis colli, lymphadenopathy with abscess formation, and one case of osteomyelitis.
Fifty patients who had a palpable soft-tissue mass and an apparently normal radiograph were studied with ultrasound imaging before excision or biopsy of the lesion was done. As shown by the sonograms, thirty-five lesions had a discrete echo pattern (usually reduced echoes and a clearly defined lesional margin) and fifteen had an ill defined pattern (similar to the pattern of the surrounding normal tissues with no definable lesional margin). Fourteen lesions were malignant and thirty-six, benign. The sonograms of all fourteen malignant lesions showed a discrete pattern, while the sonograms of the benign ones showed twenty-one discrete and fifteen ill defined patterns. Therefore, the malignant lesions produced a discrete pattern in every instance, and every lesion that produced an ill defined pattern was benign. Fourteen of the fifty lesions were cystic; of these, thirteen were benign and one was malignant. The sonograms correctly identified the cyst in seven of the thirteen benign lesions and in the one malignant cystic lesion. Based on these findings, we concluded that all palpable soft-tissue masses that appear to be discrete on a sonogram should be diagnosed without delay by examination of a specimen taken at biopsy, whereas lesions that have an ill defined appearance on a sonogram may be assumed to be benign and may safely be observed in selected patients.
Dual-photon absorptiometry (153Gd) was used to measure bone mineral of the total body and major anatomical areas. Patients with osteoporosis (male = 11, female = 18) and with renal osteodystrophy (n = 17) were significantly below (20%) normal females (n = 72) and males (n = 13) at most sites. In the osteoporotic patients, but not the renal patients, there was preferential osteopenia of the spine. Bone loss in all anatomical areas became evident after the menopause with an annual loss rate of about 0.7%.
Twenty patients in whom partial foot amputation had been performed following trauma were evaluated for successful retention of the foot. Of ten transverse stumps, only three partial feet were retained. Failure was related to poor terminal coverage from skin grafts and to equinus deformity. All ten longitudinal forefoot amputations resulted in salvage of the foot. In traumatic partial foot amputations only bone stock that is protected by innervated plantar skin should be preserved, and skin grafting should be done only in nonweight-bearing areas. Equinus deformity can be minimized by preserving and/or transplanting dorsiflexor tendons into residual bone and by supporting the foot in a custom-made ankle-foot orthosis.
We reviewed the cases of twenty-four patients with solitary or multiple exostoses to correlate their radiographic, scintigraphic, and histological evaluations. We studied twenty-five excised lesions, two of them exostotic chondrosarcomas, from twenty-two patients. There were two patterns of bone-scan activity and there was a direct correlation between enchondral bone formation and radionuclide uptake in all patients, both skeletally immature and mature. So-called quiescent lesions--those with inactive scans--were those that lacked histological evidence of enchondral bone formation. Those with increased uptake--active exostoses--all demonstrated active formation of enchondral bone. Evidence of active exostotic growth could be demonstrated on bone scans well beyond the time of skeletal maturity. The bone scan did not qualitatively differentiate the benign active exostoses from the two lesions with malignant degeneration. Increased uptake related to enchondral bone formation was a feature of both. An inactive scan, however, seemed to exclude the possibility of malignant degeneration in the exostosis.
Single-photon (I-125) absorptiometry was used to measure bone mineral content (BMC) of the distal third of the radius, and dual-photon absorptiometry (Gd-153) was used to measure total-body bone mineral (TBBM), as well as the BMC of major skeletal regions. Measurements were done in normal females, normal males, osteoporotic females, osteoporotic males, and renal patients. The BMC of the radius predicted TBBM well in normal subjects, but was less satisfactory in the patient groups. The spinal BMC was predicted with even lower accuracy from radius measurement. The error in predicting areal density (bone mass per unit projected skeletal area) of the lumbar and thoracic spine from the radius BMC divided by its width was smaller, but the regressions differed significantly among normals, osteoporotics, and renal patients. There was a preferential spinal osteopenia in the osteoporotic group and in about half of the renal patients. Bone measurements on the radius can indicate overall skeletal status in normal subjects and to a lesser degree in patients, but these radius measurements are inaccurate, even on the average, as an indicator of spinal state.
A case is presented in which the thoracodorsal artery of a latissimus dorsi free flap was anastomosed to an autogenous reverse saphenous bypass graft. The bypass graft was used to revascularise a leg with traumatic disruption of the popliteal artery and an open comminuted fracture of the distal tibia and fibula with extensive soft tissue loss. At 2-year follow up, isotope scans showed patency of the extra-anatomic graft and a good flow into the thoracodorsal artery.
Clear cell sarcoma was closely mimicked in metastatic tumor deposits from two patients with acral lentiginous malignant melanoma. A subcutaneous deposit composed of glycogen-laden spindle cells dominated the presenting clinical picture in one patient. In the other, primary acral melanoma resembled a histiocytic tumor and metastatic tumor simulated clear cell sarcoma. The cases illustrate the pleomorphism that may be encountered in malignant melanoma.
Previously, we reported that local lidocaine infusion of a CA 755 mammary adenocarcinoma growing in C57BL X DBA/2 F1 mice, when combined with local heating for 1 hr in a 43.5 degrees water bath, significantly increased survival and inhibited tumor growth more than heating alone. Because of its clinical implications, systemic lidocaine was tested in the above model system and in a murine fibrosarcoma tumor model. An equivalent supraadditive, tumor-inhibitory effect of heat and lidocaine was obtained with both systemically and intratumor-administered lidocaine. The serum levels of lidocaine necessary to achieve tumor regression were within the therapeutic range for the control of arrhythmia in humans. Several treatment schedules, varying the mode of drug delivery, were evaluated. The effects of treatment on tumor growth characteristics were analyzed using an extension of the Cox survival model.
A reactive synovitis secondary to intra-articular particles of silicone elastomer developed in three patients who had undergone Silastic hemiarthroplasty. In an attempt to duplicate this phenomenon, we used an animal model in which finely ground particulate silicone elastomer was introduced into the knee joints of adult New Zealand White rabbits. In three of thirteen rabbits (p = 0.066) histological evidence of inflammatory changes developed in the synovial tissue, similar to those seen in our patients. Intraarticular particulate silicone elastomer created by abrasion of a Silastic hemiarthroplasty may be responsible for the development of an iatrogenic reactive synovitis.
An instrument that measures pressures distribution during normal and unbalanced sitting was developed and tested. Analysis of the distribution of pressure during sitting in fifteen normal patients showed that approximately 18 per cent of the body weight is distributed over each ischial tuberosity; 21 per cent, over each thigh; and 5 per cent, over the sacrum. Three patients who had problems with sitting balance showed foci of unequal pressure which are at risk for decubitus ulceration.
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