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Biomedical subjects

C T Vangsness

Publications and source records attributed to C T Vangsness.

At least 37 records · Page 2Linked to original sources
PubMed1995

A spectrophotometer analysis of light absorption in the human meniscus.

The spectrophotometer analysis of light absorption curves in human meniscal tissue showed a reproducible series of graphs for varying tissue thickness, age, zone, and sectioning plane. These data show water as the essential reason for light absorption in the infrared portion of the light spectrum. The excimer laser in the ultraviolet region, and wavelengths around 2000 nm in the infrared region, appeared to provide the best wavelength match for laser energy transfer and the cutting or ablating of meniscal tissue. On-going research into clinical applications should focus on these wavelengths.

Absorption↗
PubMed1995

The biological effects of carbon dioxide laser surgery on rabbit articular cartilage.

A pulsed carbon dioxide laser made predetermined superficial and deep (subchondral) lesions through arthrotomies on the femoral condyles of adult New Zealand rabbits. Twenty rabbits, including controls, were divided into acute, 1-, 3-, 6-, and 12-month sacrifice groups. Early sacrifice groups showed some fibrous ingrowth from the deep lesions, but not the superficial lesions, and this was not seen in the 6- or 12-month groups. Cells below and adjacent to the laser lesions appeared viable when compared with controls. In each group studied, no histologic evidence of healing or fibrous covering in the superficial or deep laser lesions was found. No adverse clinical effects (synovitis, infection) were found in the laser groups, and the laser permitted excellent depth control during vaporization. However, the authors caution against irradiating articular cartilage.

Animals↗
PubMed1995

Review of outcome instruments for evaluation of anterior cruciate ligament reconstruction.

The need to quantify the efficacy of medical treatment has lead to the discipline of outcome assessment. Many instruments are available for the assessment of the outcome for surgical procedures in orthopaedic surgery. A review is presented of the general health outcome instruments used to assess the efficacy of specific orthopaedic procedures. To date little work has addressed the appropriate outcome instruments for evaluating anterior cruciate ligament reconstruction.

Anterior Cruciate Ligament↗
PubMed1994

The effects of the neodymium laser on meniscal repair in the avascular zone of the meniscus.

Thirty mature New Zealand white rabbits were divided into four surgical groups, and a 3- to 4-mm incision was made in the inner avascular zone of the central third of the medial meniscus. In group I, the tear was not treated by lasering or suturing. In group II, the tear was sutured. Group III was given four different doses of the neodymium:yttrium-aluminum-garnet (Nd:YAG) laser irradiation with no suturing. Group IV underwent meniscal suturing followed by the same four different laser irradiation doses. The animals were killed at 2, 4, and 6 weeks, with gross and histologic evaluation of the healing responses by group and time. The overall results showed no healing of this meniscal tear in the avascular zone. Suturing generally showed increased cellular infiltration. The varying doses of the Nd:YAG lasing demonstrated no gradient effect, and no "welding" of menisci was noted. The maximum cellular inflammatory response was noted in the sutured and lased menisci, reinforcing the importance of a stable meniscal environment for healing meniscal tears.

Animals↗
PubMed1994

Radiographic diagnosis of ankle fractures: are three views necessary?

One hundred and twenty-three sets of emergency room ankle x-rays (anteroposterior lateral and mortise) were retrospectively reviewed to determine whether all three views were necessary to diagnose the presence of an ankle fracture. Four physicians (two orthopaedic surgeons, one musculoskeletal radiologist, and one emergency room physician) reviewed all randomly ordered sets of films twice--once with all three views and once with only the lateral and mortise views. The overall accuracy of two views was within the 95% expected threshold of accuracy using three views. The lateral and mortise views alone appear sufficient for ankle fracture diagnosis, and imply a substantial decrease in radiation and cost savings to the patient.

Ankle Injuries↗
PubMed1994

A disposable fiberoptic arthroscope: a cadaver study.

Nine fresh cadaver ankle joints underwent arthroscopy to determine effectiveness of a small diameter, disposable, fiberoptic arthroscope. A sequential examination of the joint was performed through routine anteromedial and anterolateral portals. The anterior aspect of the joint with all anatomical structures was well visualized via the two anterior portals. The posterior aspect of the joint was also well visualized via anterior portals without distraction due to the flexibility of the scope and its small diameter. The quality of the visualization of the posterior joint from the anterior portals alone was comparable to that from the posterior approach. The results of this study indicate that diagnostic arthroscopy of the ankle joint with this disposable 1.6-mm arthroscope is comparable to the standard 2.7-mm to 5-mm arthroscopes. The size, flexibility, and 30 degrees viewing angle of this scope allow excellent and thorough joint visualization by routine anterior portals and minimize the need for joint distractors and posterior portals during routine diagnostic ankle arthroscopy.

Ankle Joint↗
PubMed1994

Effects of gamma irradiation on the human immunodeficiency virus. A study in frozen human bone-patellar ligament-bone grafts obtained from infected cadavera.

We studied the effects of several different doses of gamma radiation, ranging from 20,000 to 40,000 gray (2.0 to 4.0 megarad), with respect to the inactivation of the human immunodeficiency virus in fresh-frozen, whole bone-patellar ligament-bone grafts. Although the International Atomic Energy Agency has recommended the use of 25,000 gray of gamma radiation for the sterilization of medical products, the dose required for the inactivation of the human immunodeficiency virus in frozen allografts has not been established. Using one of the most sensitive and specific tests for the detection of the human immunodeficiency virus, the polymerase-chain-reaction test, we found that doses of 20,000 or 25,000 gray of gamma radiation did not destroy the genes of the human immunodeficiency virus effectively; DNA of the virus was detectable in the DNA of bone-marrow tissue obtained from grafts treated with these doses. However, DNA of the human immunodeficiency virus was not detectable in the grafts treated with 30,000 or 40,000 gray of gamma radiation. We conclude that a dose of 30,000 gray of gamma radiation or more is necessary for the sterilization of a fresh-frozen bone-patellar ligament-bone allograft, so that it can be used for reconstructive procedures without the risk of transmission of the virus to the recipient.

Bone Transplantation↗
PubMed1994

The origin of the long head of the biceps from the scapula and glenoid labrum. An anatomical study of 100 shoulders.

We dissected 105 cadaveric shoulders to study the origin of the tendon of the long head of biceps, and examined histologically the interrelationship between the tendon, the supraglenoid tubercle and the superior labrum of the glenoid. In all specimens approximately 50% of the biceps tendon arose directly from the superior glenoid labrum with the remainder attached to the supraglenoid tubercle. The main labral origin was from the posterior labrum in more than half of the specimens, and in a quarter this was the only labral attachment. On the basis of the biceps attachment to the anterior or posterior labrum, we distinguished four types of origin. These normal anatomical variations are significant for arthroscopic diagnosis and may help to explain the various patterns of injury seen in partial or complete detachment of the tendon, the labrum or both.

Cadaver↗
PubMed1994

Ipsilateral knee injury with femoral fracture. Examination under anesthesia and arthroscopic evaluation.

Forty adults with closed diaphyseal femoral fractures and no previous knee injury were prospectively studied to determine the incidence of concomitant ipsilateral extra- and intraarticular knee injury. After intramedullary nailing, examination under anesthesia and arthroscopy were performed. The mechanism of injury was high-energy trauma. Femoral fixation included 30 interlocked nails. The results of the examination showed laxity > Grade I in 52.5% of the patients. Significant arthroscopic findings included 19 partial (48%) and two complete (5%) anterior cruciate injuries; two partial (5%) and one complete (2.5%) posterior cruciate injuries; and five medial (12%) and eight lateral (20%) meniscus tears. Significant arthroscopic findings (anterior cruciate ligament or posterior cruciate ligament injuries, meniscal tear, osteochondral fracture) were noted in conjunction with effusion or laxity > Grade I in more than half of the group, and such findings were present in one third despite absence of effusion or laxity. This study documented the incidence and array of findings noted at arthroscopy. In all, 22 patients (55%) had significant arthroscopic findings. A high incidence of knee injuries, including many that were occult, occurred in conjunction with ipsilateral femoral shaft fractures. Based on these findings, the authors recommend a high index of suspicion for coexisting knee injuries with ipsilateral femoral fracture and use of appropriate diagnostic and therapeutic measures.

Adolescent↗
PubMed1994

Arthroscopy of meniscal injuries with tibial plateau fractures.

We examined 36 consecutive patients with closed tibial plateau fractures under anaesthesia and by diagnostic and operative arthroscopy before treating them by closed or open reduction and internal fixation. Following the principle of Hohl (1967) (Fig. 1) there were 9 minimally displaced fractures (type I), 6 with local depression (type II), 13 with split depression (type III), 7 with total condylar depression (type IV), and one bicondylar comminuted upper tibial fracture (type V). Seventeen (47%) of knees were found to have associated meniscal injuries which required surgical treatment; five repairs and 12 partial meniscectomies. Neither the type of plateau fracture nor the presence or absence of ligament injury correlated with meniscal tear. There were no intraoperative or postoperative complications from arthroscopy.

Adult↗
PubMed1994

Comparison of functional knee braces for control of anterior tibial displacement.

Using a surrogate knee model, the ten custom functional knee braces that previous studies had shown to be most effective were tested for restraint to anterior tibial displacement. Testing was performed at 20 degrees knee flexion with applied forces ranging from 50 to 400 N. All braces reduced anterior tibial displacement. Resistance to anterior tibial displacement depends directly on the brace design and is inversely related to the applied force. Post-bilateral hinge shell braces exhibited the most resistance to anterior tibial displacement. Few braces were effective in controlling anterior tibial displacement comparable with a normal knee at low forces. Most of the braces were less effective at controlling anterior tibial displacement at high forces.

Adult↗
PubMed1993

Meniscal injury associated with femoral shaft fractures. An arthroscopic evaluation of incidence.

We studied 47 patients with closed, displaced, diaphyseal fractures of the femur caused by blunt trauma, to determine the incidence of associated knee injuries, particularly of the meniscus. After femoral nailing, all patients had an examination under anaesthesia and an arthroscopy. There were 12 medial meniscal injuries (5 tears) and 13 injuries of the lateral meniscus (8 tears). Ten of the 13 tears were in the posterior third of the meniscus, and two patients had tears of both menisci. Synovitis was common at the meniscal attachments. Complex and radial tears were more common than peripheral or bucket-handle tears. Examination under anaesthesia revealed ligamentous laxity in 23 patients (49%), but meniscal injuries had a similar incidence in knees with and without ligament injury. Femoral shaft fractures are often associated with injuries to the ipsilateral knee, and a high index of suspicion is necessary to identify these lesions.

Adolescent↗
PubMed1993

A literature review of lasers and articular cartilage.

Articles from the English literature concerning lasers and articular cartilage were reviewed. Different experimental methods and laser systems were analyzed. Many studies lacked scientific validity. Future investigations with sound biologic foundations are recommended.

Animals↗
PubMed1993

Skeletal fixation: a review.

While improvements in surgical techniques and recent trends toward early surgery and patient mobilization have led to skeletal traction being utilized more sparingly, it continues to be a basic skill required by the orthopaedic surgeon. The most commonly used anatomical sites for skeletal fixation--distal femur, proximal tibia, distal tibia, calcaneus, and olecranon--are reviewed and illustrated.

Bone Nails↗
PubMed1991

Surgical treatment of medial epicondylitis. Results in 35 elbows.

We reviewed 35 of 38 consecutive patients who had operative treatment for medial epicondylitis of the elbow after the failure of conservative management. Their mean age was 43 years and mean follow-up was 85 months. At operation residual tears with incomplete healing were consistently found in the flexor origin at the medial epicondyle and microscopy showed reactive fibrous connective tissue with varying degrees of inflammation. The mean subjective estimate of elbow function was improved from 38% to 98% of normal, while isokinetic and grip strength testing in 16 patients showed no significant difference from the unoperated elbow. Results were excellent in 25 cases, good in nine and fair in one; 86% of the patients had no limitation in the use of the elbow.

Adult↗
PubMed1990

Functional bracing for comminuted extra-articular fractures of the distal third of the humerus.

From 1982 to 1987 we treated 85 extra-articular comminuted distal third humeral fractures in adults with prefabricated plastic braces. Of these, 15% were open fractures and 18% had initial peripheral nerve injury. On average, the sleeve was applied 12 days after injury and used for 10 weeks. There was 96% union, with no infections. All nerve injuries resolved or were improving at the latest examination. At union there was varus deformity averaging 9 degrees in 81% of patients, but loss of range of movement was minimal and functional results were good.

Adolescent↗