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Biomedical subjects

J J Rodrigo

Publications and source records attributed to J J Rodrigo.

30 records · Page 2Linked to original sources

Deep-freezing versus 4 degrees preservation of avascular osteocartilaginous shell allografts in rats.

Osteocartilaginous allografts (distal femurs of rats) were stored at 4 degrees for six, 12, 24, and 48 hours and at -80 degrees for five days and then evaluated for viability of the bone and cartilage. Storage at 4 degrees for 12 or 24 hours had little effect on cartilage viability but decreased bone viability to 40% and 10% of controls, respectively. Storage at -80 degrees for five days resulted in nonviable bone in all cases but showed an either/or response of cartilage, with high viability in two cases and nonviability in the other eight cases. In a second set of experiments, femurs from rats were stored in situ at 4 degrees for 12 or 24 hours or were harvested and stored at -80 degrees for five days, after which they were transplanted into rats of a different strain. The antibody response to each set of femurs was measured at two, six, and 12 weeks after operation. The 4 degrees storage resulted in a moderately decreased immunogenicity, whereas the storage at -80 degrees resulted in significantly reduced immunogenicity.

Animals↗

Replacement of the anterior cruciate ligament with a bone-ligament-bone anterior cruciate ligament allograft in dogs.

Acute replacement of the canine anterior cruciate ligament (ACL) with a frozen, bone-ligament-bone anterior cruciate ligament preparation was studied using biochemical, immunologic, and biomechanical testing methods. Nine dogs were used for the study, six dogs received allografts and three received autografts. No tissue antigen matching was performed. All nine dogs were killed nine months after surgery. Necropsy examination revealed that the ACL was not present in three joints (one autograft, two allografts). The two autograft and four allograft ligaments available for mechanical testing sustained mean maximum loads that were 10% and 14%, respectively, of the mean maximum loads sustained by the contralateral ACL. Autoradiography indicated that cellular activity was more pronounced in the autograft specimens. Hydroxyproline uptake was 200% and 45% of normal in the autograft and allograft ligaments, respectively. Both autograft and allograft specimens were producing Type I collagen at the time of killing. Antidonor dog leukocyte antigen (DLA) antibody was detected in the synovial fluid taken at the time of killing from six of six dogs that received allografts and in zero of three dogs that received autografts.

Animals↗

Pedicle fat grafts for the prevention of scar in low-back surgery. A preliminary report on the first 92 cases.

Encouraged by the results of an experimental study on dogs, the authors performed pedicle fat grafts in 92 patients. The grafts were used in the following groups of patients: following primary disc removal (37 cases); following scar removal in the multiply operated back with definite root findings (37 cases); in patients with spondylolisthesis who had had prior decompressions but developed fifth lumbar nerve root pain after lateral fusion (6 cases); in three patients with spondylolisthesis and simple decompression; in nine patients with spinal stenosis. Pedicle fat grafts were obtained from the subcutaneous layer of fat of the low back in 85 patients and from the buttocks in seven patients. The grafts were brought through openings in the fascia and muscle and were used to cover the dural sac as well as the margins of the nerve root. They were held in position by a fine suture of silk. The results after a minimum follow-up of 1 year and a maximum of 4 years have been excellent or good in 66 percent of the patients who have had lateral fusion with resultant L5 root compression, in 99 percent of patients with spondylolisthesis and decompression only, and in 66 percent of patients with spinal stenosis. The results in the other two groups compare favorably with those reported in the literature.

Adipose Tissue↗

Computed tomography of the musculoskeletal system.

To demonstrate the potential impact of computed tomography on orthopaedics, a brief review was done of four generations of scanners and of one new development (assay of bone mineral in the spine) that is presently being researched. To assess the utility of the method in treating orthopaedic problems, the cases of 140 patients, including patients with congenital anomalies, tumors, infections, and traumatic lesions, were analyzed. In the majority of the patients the technique provided useful information, often unobtainable with any other technique.

Bone Diseases↗

99mTc-methylene diphosphonate bone imaging in the evaluation of total hip prostheses.

A retrospective study was performed to determine the accuracy of 99mTc-methylene diphosphonate bone imaging in the evaluation of total hip arthrosplasty for lossening and/or infection. Using focally increased activity at the tip of the femoral component or in the region of the acetabular component as a criterion, the examination was 77% specific and 100% sensitive for loosening and/or infection. A possible explanation for the increased uptake at the tip of the femoral component and the role of this examination in the management of a painful total hip prosthesis are discussed.

Bone Diseases↗

Treatment of Dupuytren's contracture. Long-term results after fasciotomy and fascial excision.

Of 359 hands treated surgically for Dupuytren's contracture, 135 were available for study after two years or more, often because of recurrence. Of the sixty-five hands treated by excision of the involved fascia (subtotal fasciectomy), 63 per cent had recurrences in the area operated on but only 15 per cent had sufficient deformity to warrant another operation. Of the forty-one hands treated by palmar fasciotomy, 43 per cent had recurrent deformities severe enough to warrant further surgical treatment. After palmar fasciotomy, improvement at the metacarpohalangeal joint persisted; but, as expected, the deformity at the proximal interphalangeal joint progressed just as it did in an untreated control group. The average postoperative period of disability was fifty-nine days after fasciectomy and twenty-one days after fasciotomy. Stiffness and hematoma occurred after fasciectomy but were not observed after fasciotomy. A digital nerve was severed during one fasciotomy and one fasciectomy. Excision of the involved fascia, therefore, gave the best long-term results but was associated with a higher incidence of postoperative complications.

Dupuytren Contracture↗

Arthrography for the assessment of pain after total hip replacement. A comparison of arthrographic findings in patients with and without pain.

Arthrography in twenty-five painful hips of twenty-one patients after total hip replacement and in fifty-three asymptomatic hips of forty-two patients after this procedure showed that arthrographic evidence of loosening was not always associated with pain. More than one-fifth of the asymptomatic hips had arthrographic evidence of loosening. Furthermore, the loosening shown by arthrogram could be confirmed in only seven of twelve hips that were subsequently explored. In addition, there was no apparent relationship between arthrographic loosening and the presence of a Trendelenburg sign. This study casts doubt on the value of an arthrogram in the diagnosis of the cause of pain after total hip replacement.

Hip↗