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Biomedical subjects

Samuel B Adams

Publications and source records attributed to Samuel B Adams.

11 recordsLinked to original sources
PubMed2006

An allogenic cell-based implant for meniscal lesions.

BACKGROUND: Meniscal tears in the avascular zones do not heal. Although tissue-engineering approaches using cells seeded onto scaffolds could expand the indication for meniscal repair, harvesting autologous cells could cause additional trauma to the patient. Allogenic cells, however, could provide an unlimited amount of cells. HYPOTHESIS: Allogenic cells from 2 anatomical sources can repair lesions in the avascular region of the meniscus. STUDY DESIGN: Controlled laboratory study. METHODS: Both autologous and allogenic chondrocytes were seeded onto a Vicryl mesh scaffold and sutured into a bucket-handle lesion created in the medial menisci of 17 swine. Controls consisted of 3 swine knees treated with unseeded implants and controls from a previous experiment in which 4 swine were treated with suture only and 4 with no treatment. Menisci were harvested after 12 weeks and evaluated histologically for new tissue and percentage of interface healing surface; they were also evaluated statistically. RESULTS: The lesions were closed in 15 of 17 menisci. None of the control samples demonstrated healing. Histologic analysis of sequential cuts through the lesion showed formation of new scar-like tissue in all experimental samples. One of 8 menisci was completely healed in the allogenic group and 2 of 9 in the autologous group; the remaining samples were partially healed in both groups. No statistically significant differences in the percentage of healing were observed between the autologous and allogenic cell-based implants. CONCLUSION: Use of autologous and allogenic chondrocytes delivered via a biodegradable mesh enhanced healing of avascular meniscal lesions. CLINICAL RELEVANCE: This study demonstrates the potential of a tissue-engineered cellular repair of the meniscus using autologous and allogenic chondrocytes.

Absorbable Implants↗
PubMed2006

Mastication causing segmental spinal motion in common cervical orthoses.

STUDY DESIGN: In vivo fluoroscopic quantification of segmental cervical spinal motion in asymptomatic volunteers during mastication. OBJECTIVE: To quantify the degree of segmental cervical spine motion in patients during mastication and while wearing several commonly used cervical orthoses. SUMMARY OF BACKGROUND DATA: Cervical orthoses are routinely used to stabilize the cervical spine after trauma or cervical fusion and are, in some cases, prescribed to be worn at all times, including during eating. METHODS: Seven volunteers with an average age of 31 years (range, 26-42 years) had 5 seconds of continuous lateral cervical fluoroscopic imaging while they chewed gum without any cervical orthosis (control) and while wearing a soft collar turned forward then backward, a Philadelphia collar, a Miami J collar, or a two-poster brace. Still images were created from the fluoroscopy video, which allowed for quantification of the amount of segmental motion. RESULTS: All cervical collars produced statistically greater motion at occiput-C1 and C1-C2 when compared with no collar. The motion was greatest at the occiput-C1 junction and decreased to the C4 level. No motion was detected in any subject in any brace below C4. The two-poster brace produced the most segmental motion at occiput-C1 (6.3 degrees +/- 2.0 degrees) compared with the soft collar turned backwards (1.9 degrees +/- 1.9 degrees). No subject had any segmental motion below C2 in the soft collar. No segmental spinal motion was observed without a cervical brace. CONCLUSIONS: To limit upper cervical spine segmental motion during mastication, for patients with unstable cervical spines, we propose a two-poster brace with removal of the mandibular component to allow for free mandibular action. For stable spines, we propose a soft collar turned backwards. Patients should be educated with this information.

Adult↗
PubMed2006

Healing potential of transplanted allogeneic chondrocytes of three different sources in lesions of the avascular zone of the meniscus: a pilot study.

UNLABELLED: Successful treatment of tears to the avascular region of the meniscus remains a challenge. Current repair techniques, such as sutures and anchors, are effective in stabilizing the peripheral, vascularized regions of the meniscus, but are not adequate for promoting healing in the avascular region. The purpose of this study was to demonstrate the healing ability of a tissue-engineered repair technique using allogenic chondrocytes from three different sources for the avascular zone of the meniscus. MATERIAL AND METHODS: Articular, auricular, and costal chondrocytes were harvested from 3-month-old Yorkshire swine. A 1-cm bucket-handle lesion was created in the avascular zone of each three swine. A cell-scaffold construct, composed of a single chondrocyte cell type and Vicryl mesh, was implanted into the lesion and secured with two vertical mattress sutures. Controls consisted of each three sutured unseeded mesh implants, suture only, and untreated lesions. The swine were allowed immediate post-operative full weight bearing. Menisci and controls were harvested after 12 weeks. RESULTS: In all experimental samples, lesion closure was observed. Gross mechanical testing with two Adson forceps demonstrated bonding of the lesion. Histological analysis showed formation of new tissue in all three experimental samples. None of the control samples demonstrated closure and formation of new matrix. CONCLUSION: We present preliminary data that demonstrates the potential of a tissue-engineered, allogenic cellular repair to provide successful healing of lesions in the avascular zone in a large animal model.

Animals↗
PubMed2006

High-resolution imaging of progressive articular cartilage degeneration.

The objective of this study was to develop and verify a new technique for monitoring the progression of osteoarthritis (OA) by combining a rat model with the imaging modality optical coherence tomography (OCT). Time-sequential, in vivo, OCT imaging was performed on the left femoral condyles of 12 Wistar rats following sodium-iodoacetic acid-induced OA progression. The right femoral condyles (untreated) were also imaged and served as controls. Imaging was performed on days 0, 10, 20, 30, and 60 with an OCT system capable of acquiring images at four frames per second and an axial resolution of 5 microm. Progressive changes were analyzed using an OA scoring system. OCT successfully identified progressive cartilage degeneration as well as alteration of the cartilage/bone interface. Significant changes to both of these structures were observed in the sodium-iodoacetic acid-injected condyles. Structural changes detected with OCT were confirmed histologically. OCT in combination with a well-known model used in arthritis research represents a powerful tool for following degenerative joint disease progression in a given animal by detecting changes to the cartilage/bone interface and articular cartilage.

Animals↗
PubMed2006

Wound healing agents.

This report presented a review of the process of wound healing as well as influencing factors in the process such as wound healing agents. A greater understanding of the alterations in diabetes mellitus allows selection of the optimal wound healing agents to provide a more optimistic approach to wound closure for this large population of diabetics. We have reviewed some of the most common products use adjuncts to the healing process. With newer innovation such as the use of negative pressure dressings and HBO therapy, the treatment of diabetic wound continues to improve. With the increased number of healing agents, it is important to consider the kind of wound and the conditions present when selecting one healing agent over another.

Bandages↗
PubMed2005

Tissue engineering for meniscus repair.

Meniscus injury is common in today's active society. Despite the frequent presentation of meniscus injury, the decision to repair or resect a torn meniscus is not always straightforward. Current repair techniques are effective in the peripheral vascularized meniscus, but their success is not dependable in the avascularized zone. Tissue engineering, a discipline that combines the technologies of cell culture and biodegradable scaffolds to deliver a cellular repair, may be one future answer to this problem. The concept of using cell-based repair for torn menisci could improve healing of lesions in the avascular zone and broadly expand the indication for repair rather than removal, obviating the need for meniscectomy. This article reviews current advances in the relatively new field of tissue engineering toward the development of a tissue-engineered meniscal repair technique.

Chondrocytes↗
PubMed2005

Patient behavior if given their surgeon's cellular telephone number.

Technologic advances in communications potentially may affect the patient-doctor relationship. We assessed call patterns, reasons for calling, and attitudes if patients had their surgeon's cellular telephone number, to determine if there are potential benefits to this practice. Postoperative calls made by patients to the surgeon, secretary, and surgical scheduler were categorized as urgent or nonurgent. Twenty of 32 (63%) consecutive patients made 65 calls during a 2-month period. Only 12 calls (18%) were to the surgeon. Fifty percent were urgent, as opposed to 14% and 15% of calls to the secretary and surgical scheduler, respectively. Subsequently, 201 patients were prospectively administered a 10-question survey assessing patient attitudes if given direct access to their surgeon. Eighty percent owned a cellular telephone, 85% would call the surgeon, and 30% would prefer the surgeon as the first line of communication. Communicating through E-mail or home phone was less desirable than through the nurse or cellular telephone. Seventy-two percent thought that having cellular telephone access suggested that their surgeon was more caring. Patients desired to communicate directly with surgeons, but act with restraint and call as a last resort for mostly urgent issues if given the physician's cellular telephone number. The cellular telephone has promising benefits for the patient-physician relationship.

Adult↗
PubMed2004

Predictors of progression of scoliosis after decompression of an Arnold Chiari I malformation.

STUDY DESIGN: Retrospective study of patients with scoliosis and an Arnold Chiari I malformation requiring operative management. OBJECTIVES: Determine the factors that could predict whether a particular spinal deformity might progress despite neurosurgical management of Arnold Chiari I malformation. SUMMARY OF BACKGROUND DATA: Few studies have documented the relationship between diagnosis and treatment of Arnold Chiari I malformation and associated spinal deformities. Most studies mix neural axis abnormalities and contain limited information about the spinal deformity. METHODS: Medical records, radiographs, and magnetic resonance images of patients were evaluated focusing on age and findings at presentation, characteristics of presenting and follow-up spinal deformities, and the specifics of neurosurgical and orthopedic management. Patients were divided into two groups: those whose curves progressed >10 degrees or to surgical range (largest curve >45 degrees ) after neurosurgical intervention (progressors) and those whose curves stabilized or decreased (nonprogressors). RESULTS: Eight progressors presented at an average age of 11.4 years (range 2-19) and were followed for 6.3 years (range 2-15). Seven nonprogressors presented at 6.5 years of age (range 5-10) and were followed for 6.6 years (range 3.5-14). Neurosurgical procedures were equivalent in both groups; however, surgical revisions were required in 3 out of 8 progressors and 1 out of 7 nonprogressors. All progressors had a double scoliosis curve; but only one nonprogressor had a double curve. Six out of 8 progressors and 0 out of 7 nonprogressors had a rotation >or=2+ and 50% of progressors had a thoracic kyphosis >50 degrees compared to 1 out of 7 nonprogressors. CONCLUSIONS: In this series, progression of spinal deformity after neurosurgical management of Arnold Chiari I malformation was associated with later age at neurosurgical decompressions and initial neurologic symptoms, double scoliosis curve patterns, kyphosis, rotation, and larger curve at presentation.

Adolescent↗
PubMed2003

Torticollis in an infant caused by hereditary muscle aplasia.

Torticollis is a common condition presenting to the general or pediatric orthopedist. We describe the case of a child with severe torticollis caused by a hereditary unilateral absence of the sternocleidomastoid and trapezius muscles. Both his father and paternal grandfather had a forme fruste, with similar but milder findings. Electromyography and cross-sectional imaging were valuable in making the diagnosis. We believe this is the first reported case of hereditary unilateral muscle aplasia presenting as torticollis in an infant.

Cholera Toxin↗
PubMed2002

Safety and efficacy of the popliteal fossa nerve block when utilized for foot and ankle surgery.

The popliteal fossa nerve block (PFNB) offers numerous advantages that make it a suitable anesthetic technique for foot and ankle surgery. In this retrospective study, we investigated the acute and long-term safety and efficacy of this relatively underutilized anesthetic technique for foot and ankle surgery. A review of 834 patients who underwent foot and/or ankle surgery by the coauthor (NAA) was conducted. Four hundred sixty-seven patients received a PFNB with the aid of a peripheral nerve stimulator. Variables assessed included the quality of surgical anesthesia, postoperative analgesia and the acute and long-term incidence of postoperative neuralgia and neuropraxia. The PFNBs were performed by anesthesiologists with various levels of training at a tertiary care hospital and all were supplemented with a saphenous nerve block. The PFNB was successful as the sole anesthetic technique in 79% of the cases; 18% were converted to general anesthesia and 3% required augmentation with local anesthetic. There were no complications associated with the PFNB. There were no incidents of postoperative neuralgia or neuropraxia. Only 12% of patients with a successful block required analgesics in the PACU, while 60% of patients with a failed block required systemic analgesics for surgical site pain (p<0.01). These results suggest that the performance of the PFNB with the guidance of a peripheral nerve stimulator is a safe and effective anesthetic technique for foot and ankle surgery.

Ankle↗