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Biomedical subjects

F M Ivey

Publications and source records attributed to F M Ivey.

32 records · Page 2Linked to original sources
PubMed1997

Muscle balance at the knee--moment arms for the normal knee and the ACL-minus knee.

Forces, moments and stresses at the knee are dependent upon external and internal loading factors including muscle forces, segmental position and velocity, load carried, and the moment arms (mechanical advantage) of the muscle-tendon units. Requisite to prediction of forces and moments is a detailed understanding of effective moment arms throughout the knee range-of-motion (ROM). Existing muscle models for the knee are based upon limited static studies of only a few preserved specimens. The objectives of this report are to develop a comprehensive description of muscle-tendon moment arms for the normal knee and the anterior cruciate ligament (ACL)-minus knee during flexion-extension motion. Recent research results describe two nonorthogonal, nonintersecting axes of motion for the knee--one describing flexion-extension (FE) and the other longitudinal rotation (LR, equivalent to internal-external rotation). The effective flexion-extension moment arms of the muscles crossing the knee were developed with respect to the FE axis in 15 fresh, hemi-pelvis cadaver specimens. The normal moment arms for each of 13 muscles plus the patellar tendon exhibited variable, yet repeatable and recognizable patterns throughout the ROM. For most muscles there was no significant difference between the normal and ACL-minus moment arms. The results provide a basis for more accurate predictions of joint reaction forces and moments as well as useful knowledge for practitioners and therapists to assist in the assessment of muscle balance at the knee following injury, repair, and throughout rehabilitation.

Adult↗
PubMed1992

Serum bupivacaine concentrations after intraarticular injection for pain relief after knee arthroscopy.

Intraarticular injection of local anesthetic drugs after arthroscopic knee surgery is used to provide postoperative analgesia. Toxic serum levels of bupivacaine have been reported after its use both in regional anesthesia and for intraarticular injection. The toxicity of the former is related to needle misplacement and the latter is presumed to be absorptive. This study evaluates the effect of tourniquet inflation and the addition of epinephrine on serum concentrations of bupivacaine after intraarticular injection. The results shows that the peak serum bupivacaine concentrations can be reduced by adding epinephrine and injecting it after tourniquet inflation.

Adult↗
PubMed1989

Characteristics of successful and unsuccessful applicants to orthopedic residency training programs.

In 1985 there were 288 applicants for the ten postgraduate Year 1 orthopedic residency positions in Galveston and San Antonio, of which 119 (41%) applicants successfully obtained a residency position in one of 76 orthopedic programs approved by the Accreditation Council for Graduate Medical Education. Successful applicants were younger and had higher Medical College Admissions Test scores, National Board of Medical Examiners, Part I (NBME-I) scores, and medical school grade point averages than unsuccessful applicants. Variables that increased acceptance rates were medical student status, an NBME-I score above 500, class rank in the top 40%, and membership in Alpha Omega Alpha honor society. Foreign citizenship and prior residency experience in a different specialty strongly decreased acceptance rates. Variables that did not affect acceptance rates were: gender, military experience, marital status, graduate degree, research, publications, or NBME-II scores.

Adult↗
PubMed1986

A comparison of various types of fixation devices for protection of the posterior cruciate ligament against a posterior drawer force.

We compared four different fixation devices to determine which offers the greatest relative protection to the posterior cruciate ligament (PCL) against elongation with an applied posterior drawer force. We designed a system to monitor and record the change in distance between an approximate origin and insertion of the PCL as known forces were applied posteriorly to the tibia with the femur fixed. Six fresh cadaver knees were used in this investigative series. They were first tested with the PCL intact, then with the PCL transected, and then with the various fixation devices applied. After comparing the results with transarticular pins and quadrilateral and anterior half-frame external fixators, we found that transarticular fixation offers significantly greater protection to the PCL. This study may prove to be helpful to the orthopaedist when selecting ancillary fixation for posterior cruciate repair or reconstruction.

Adult↗
PubMed1986

Nontraumatic clostridial myonecrosis, a case report.

Physicians are aware of the association between massively contaminated wounds and clostridial myonecrosis, or gas gangrene. A far less common but equally devastating presentation is that of nontraumatic or spontaneous gas gangrene. The most frequently encountered organism in this rare form of gangrene is Clostridium septicum, and there is a high correlation with hematologic or gastrointestinal malignancy. The mainstays of treatment are intravenous antibiotics, surgical debridement, and hyperbaric oxygen therapy. The prognosis is dependent upon early recognition and institution of treatment.

Adenocarcinoma↗
PubMed1985

Isokinetic testing of shoulder strength: normal values.

In isokinetic muscle testing of the shoulders of 31 normal volunteers, no statistical difference was found between dominant and nondominant shoulders, even though there was a consistent pattern of greater strength in the dominant shoulder. Internal rotation strength was greater than external rotation (p less than 0.01) by the ratio of 3:2 for both the fast and slow torque arm speed. Extension strength was greater than flexion (p less than 0.01) by a ratio of 5:4 at both speeds. Adduction strength was greater than abduction (p less than 0.01) by a ratio of 2:1 for both speeds. Overall, adduction strength was greatest, followed by extension, flexion, abduction, internal rotation, and external rotation. Male strength was greater than female, but the advantage decreased when normalized for lean body mass and exercise habit.

Adult↗
PubMed1982

Thomas B. Quigley, M.D., and the meniscus.

Utilizing material from a registry of knee surgery, subsequent operations relating to meniscectomy were reviewed. The overall reoperation rate for the entire series was 30%; 6% of the patients eventually had at least the other meniscus removed. One out of ten had subsequent anterior stabilization with or without removal of the meniscus. Only 4% had an osteotomy, knee replacement or arthrodesis at a later date. Further and expanded studies may aid in further understanding the ultimate fate of meniscectomized knees. Longer follow-up examinations are required to evaluate the long term results following removal of the meniscus through the operative arthroscope.

Arthrodesis↗
PubMed1982

Evaluating acute knee injuries.

The diagnosis of acute knee injuries should be as precise as possible. A wait-and-see attitude is condemned. A complete diagnosis cannot always be made on the basis of history, physical examination and x-rays. Additional aids, such as stress films, joint aspiration, arthrography, examination under anesthesia and arthroscopy, increase diagnostic accuracy to nearly 100 percent. Only then can the physician properly manage the patient so that long-term disability is minimized.

Acute Disease↗
PubMed1979

Patellofemoral replacement.

From an analysis of the clinical evaluation of 85 cases and subsequent revisionary procedures, patients for isolated patellofemoral joint replacements should be carefully selected. At the present time, the primary indications are distortion or severe degeneration of the femoral groove.

Adult↗
PubMedDate not supplied

Treatment options for infected knee arthroplasties.

Twenty-four total knee arthroplasty infections in 23 patients treated over a 9-year period at the University of Texas Medical Branch at Galveston were retrospectively reviewed. Staphylococcus epidermidis was isolated from 11 of 24 and Staphylococcus aureus from eight of 24 knees, respectively. Eleven infections were polymicrobic. Control of infection was obtained in 13 of 13 patients treated initially with resection arthroplasty, and 11 of these were ambulatory at follow-up. Infection was controlled in three of 10 knees treated initially with debridement, and six of these nine patients were ambulatory at follow-up. One patient was initially treated with amputation. Four of four patients treated by resection arthroplasty and then by reimplantation were ambulatory without signs of infection at follow-up. Resection arthroplasty reliably controls infection but produces a painful unstable joint that requires brace support or subsequent surgery for pain-free ambulation. Reimplantation in selected patients offers the best chance for pain-free ambulation.

Adult↗
PubMedDate not supplied

Arthroscopy of the knee under general anesthesia: an aid to the determination of ligamentous instability.

During a 34-month period (March 1976 through December 1978), 790 patients underwent arthroscopic examination of the knee under general anesthesia. Preoperative assessment of ligementous instability was compared with the ligamentous examination while under general anesthesia. Eight percent of the patients with no preoperative instability first demonstrated ligamentous instability under general anesthesia. Thirty-six percent of the patients with preoperative instability and 27% of the patients with previous surgery had either an increased grade or additional component of instability found when examined under general anesthesia. Information gained from arthroscopy without a comprehensive ligament examination under anesthesia may result in an incomplete diagnosis and ineffective treatment. Patients at high risk include those with acute injuries, preoperative instability, or previous surgery.

Adult↗
PubMedDate not supplied

Intraarticular substitution for anterior cruciate insufficiency. A clinical comparison between patellar tendon and meniscus.

Forty two patients with functionally incapacitating 2+ or 3+ anterior instability underwent anterior cruciate ligament substitution using a meniscus (25 patients) or central third of the patellar tendon (17 patients). Subjective and objective evaluations were personally performed on all patients with an average followup of 15 months. Seventy-nine percent of the patients were objectively graded successful. Objective results were primarily based on the surgeon's technical ability to correct completely all components of anterior instability at the time of surgery. Subjective results were multifactorial and were correlated primarily with patient expectations, the presence or absence of continued buckling and the ability to return to recreational activities. The only observed difference between the two types of cruciate substitutions was the average loss of 6 degrees of flexion in the central third of the patellar tendon group. Both the patellar tendon and meniscus clinically appeared to be successful intraarticular cruciate substitutes which can predictably correct moderate to severe anterior instability of the knee in a high percentage of patients.

Adolescent↗
PubMedDate not supplied

Extra-articular stabilization of the knee joint for anterior instability.

The results after one year or longer were evaluated in 76 patients with extra-articular reconstruction for functionally disabling anterior instability of the knee joint. The reconstruction was performed by a modification of the Ellison procedure for treatment of anterolateral rotatory instability. The various superimposed components of knee instability were managed by a variety of methods. Postoperatively,objective stability correlated well with subjective improvement. Patients with 2+ or greater anterior instability preoperatively had disappointing results in both subjective symptoms and objective signs. although extra-articular reconstruction may be sufficient for lesser grades of functionally disabling instability, knees with grade 2-3+ instability may require direct anterior cruciate ligament reconstruction in addition to the extra-articular surgical procedure.

Evaluation Studies as Topic↗