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Biomedical subjects

A B Swanson

Publications and source records attributed to A B Swanson.

At least 19 recordsLinked to original sources
PubMed1992

Femoral head intramedullary stemmed implant. A historical prospective.

A historical review reveals that McBride may have been the first to use a femoral head intramedullary stemmed hip implant. It had a threaded stem and limited use. Eicher may have been the first to develop and use the smooth intramedullary stemmed femoral implant with a calcar collar, which was the forerunner of implants used today. Moore subsequently developed the self-locking intramedullary stemmed femoral implant with a calcar collar. Shortly thereafter, Thompson introduced a similar prosthesis. These four surgeons pioneered the development of the intramedullary stemmed femoral head prosthesis, which has been a key contribution to modern hip reconstruction.

Femur Head↗
PubMed1991

Constrained total elbow arthroplasty.

In 1972, the senior author designed a condylar-sparing constrained hinge elbow prosthesis with a high-density polyethylene bushing. The condylar-sparing design allows both intercondylar and intramedullary fixation of the humeral component with methylmethacrylate cement. Reattachment of the muscles and collateral ligaments to the preserved condyles provides further stability. The clinical experience spans more than 16 years in 42 elbows with a relatively low loosening rate of 7%. The implant was removed and not replaced in three elbows: one for late infection, one for posttraumatic comminuted fracture of the distal humerus, and one for loosening of a humeral component. A series of 27 patients (31 elbows) with 24-204 months of follow-up study (average, 77 months) had excellent pain relief and an average range of motion of 129 degrees flexion, -44 degrees extension, 69 degrees pronation, and 61 degrees supination.

Bone Cements↗
PubMed1991

The use of a grommet bone liner for flexible hinge implant arthroplasty of the great toe.

Press-fit titanium grommets were developed to shield flexible hinged silicone implants used for arthroplasty of the radiocarpal, metacarpophalangeal, and metatarsophalangeal joints. Since 1985, 179 titanium circumferential grommets were used in 90 first metatarsophalangeal joints with excellent, pain-free, functional results and favorable bone response around the implant stems and at the bone-grommet interface. There were no complications due to particulate reactivity, implant fracture, or grommet fracture. The use of circumferential titanium grommets appears to be a safe and effective method to improve the long-term durability of flexible hinge implant arthroplasty of the first metatarsophalangeal joint.

Adult↗
PubMed1991

Local hypothermia to prolong safe tourniquet time.

Local hypothermia was studied as a method to safely prolong tourniquet time for reconstructive procedures of the upper extremity. An ice blanket constructed of flannel cloth and cold gel packs was applied to the limb for 45 minutes preoperatively. Seventy-eight patients were evaluated for complications resulting from hypothermia and prolonged tourniquet application. The duration of continuous tourniquet ischemia averaged two hours and 25 minutes. Intraoperative muscle temperature recordings indicated that the iced limbs were an average of 12.9 degrees cooler than noniced limbs before tourniquet inflation. Electron microscopic studies of biopsied muscle showed no evidence of ischemic changes. There were no postoperative complications associated with prolonged tourniquet inflation or the hypothermia blanket technique. Local hypothermia appears to be a safe and effective method of decreasing the adverse effects of tourniquet ischemia and allowing continuous tourniquet inflation time to extend safely beyond the customary two-hour limit.

Adult↗
PubMed1990

[Krukenberg-plasty in young patients].

The Krukenberg procedure has been performed unilaterally on juvenile amputee patients with congenital bilateral absence of the hands and observed by long-term follow-up examinations. The opposite extremity was routinely fitted with a standard prosthetic prescription as an assistive hand. In all cases, the Krukenberg stump became the leading hand. In some of the cases, the prosthesis on the opposite hand has been discarded in favour of the sensibility available without it. The prehension ability of the Krukenberg stump has provided the patient with all of his functional needs. The results have been remarkably rewarding to these patients. There has been virtually no concern evidenced by the patient or the parents about the appearance of the stump. The surgical procedure has been considered by be reasonably uncomplicated. Postoperative rehabilitation has been simple and rapid. The patients have continued to improve in their rehabilitation, and the Krukenberg forceps with its improved prehension and sensibility has improved the quality of life of these people. This procedure should be extended to more individuals who have the severe handicap of bilateral hand loss.

Adolescent↗
PubMed1990

Bateman bipolar hip arthroplasty for femoral neck fractures. A five- to ten-year follow-up study.

Displaced femoral neck fractures in 128 patients were treated with cemented Bateman universal proximal femoral bipolar hemiarthroplasties. The follow-up period ranged from five to ten years. In the surviving 49 cases, the average follow-up period was seven years and five months. Seventy-nine percent of surviving patients had no or slight pain after their primary procedure. None of these patients developed acetabular protrusio. Ten percent of the survivors required late revision; 88% of the unrevised hips had no or slight pain. When compared with studies of noncemented Moore and Thompson fixed-head prostheses, the cemented Bateman bipolar prosthesis had decreased protrusio and less pain.

Aged↗
PubMed1989

Bipolar implant shoulder arthroplasty. Long-term results.

The bipolar shoulder implant (BSI), designed by the senior author in 1975, has an unfixed metal glenoid cup with a polyethylene liner that articulates with a cemented titanium humeral component. The BSI was inserted in 35 shoulders of 33 patients with severe rheumatoid arthritis (20 cases), degenerative arthritis (ten cases), and posttraumatic lesions (five cases). The follow-up period ranged from 24 to 140 months (average, 63 months). Pain relief was good to excellent in 31 shoulders; four experienced some pain during daily activities. After BSI, motion was greatly improved with 71 degrees average range of abduction, 23 degrees range of adduction, 79 degrees range of flexion, 45 degrees range of extension, 76 degrees range of internal rotation, and 28 degrees range of external rotation. BSI was well-tolerated by the bone and soft tissues, with no erosive changes at the coracoacromial arch. There was no evidence of loosening at the cement-bone interface. One patient with a postoperative subcoracoid dislocation maintained a good functional result for more than 11 years. One BSI had draining sinus tract with negative culture, which spontaneously healed following removal of the implants. There were 3.3 mm (range, -7 mm to 11 mm) of superior subluxation of the humeral head on the preoperative roentgenogram. This increased to 8.7 mm (range, -5 mm to 20 mm) in the long-term follow-up roentgenogram. The bipolar implant is specially indicated in the severely arthritic shoulders in patients with vertical humeral subluxation and complicated histories of multiple failed operations.

Adult↗
PubMed1989

Evaluation and treatment of the upper extremity in the stroke patient.

Selected surgical procedures to correct specific deformities of the upper extremity in the stroke patient related to muscle imbalance, spasticity, contracture, and joint instability as seen in spastic hemiplegia are described. The postoperative rehabilitation is also discussed with regard to functional and anatomic disabilities, considering first the patient, then the extremity, and finally, the hand.

Arm↗
PubMed1988

Doctors! Wake up!

Explore the source record for details and available documents.

Anecdotes as Topic↗
PubMed1987

Evaluation of impairment in the upper extremity.

A system for evaluation of physical impairment in the hand and upper extremity was developed and has been tested and used by many hand surgeons around the world. It was approved for international application by the International Federation of Societies for Surgery of the Hand. A method for evaluating amputation and sensory and motion impairments has been devised for the hand and upper extremity. Amputation impairment percentage values were determined for each digit or position thereof for the hand, wrist, elbow, and shoulder. By a principle of progressive multiplication of percentage values, impairment of a part can be related to the hand, upper extremity, and eventually the whole person. Sensory impairment is given 50% that of an amputation. Impairment of finger motion can result from lack of flexion (F), extension (E), or ankylosis (A). The method for evaluating flexion impairment is based on a combined angular measurement principle that was correlated with the linear measurement of Boyes. Values for flexion and ankylosis impairment were obtained from the American Medical Association guide. Values for extension impairment were derived from the formula A = E + F. Values for hyperextension were given consideration in the impairment tables. The sum of impairments as related to the whole hand equals the total impairment. The method to combine various impairments is based on the principle that each impairment acts not on the whole part (e.g., the finger) but on the remaining portion (e.g., proximal interphalangeal joint and proximally) after the preceding impairment has acted (e.g., on the distal interphalangeal joint). When there is more than one impairment to a given part, these must be combined before conversion to a larger part. The combined values determination is based on the formula "A% + B% (100% - A%) = the combined values of A% + B%." Based on this principle, the physical loss of each anatomic segment is related to the part, to the entire hand, and then to the body. The common impairment values have been placed in a table form for easier use.

Accidents, Occupational↗
PubMed1987

Reconstruction of the thumb basal joints. Development and current status of implant techniques.

The problems presented at the thumb basal joints differ in osteoarthritis and rheumatoid arthritis. Therefore, the proper treatment must be selected from several options including resection of the trapeziometacarpal joint with or without a convex or concave condylar implant and resection arthroplasty of the trapezium with or without a trapezium implant. Proper medialization of any basal thumb implant and stability over the scaphoid facet are essential for a good result. Balance of the entire thumb ray is critical and stabilization or fusion of the distal articulations of the thumb may also be considered.

Arthroplasty↗
PubMed1986

Scaphoid implant resection arthroplasty. Long-term results.

A silicone scaphoid implant was developed in 1967 to help improve the results of simple resection arthroplasty in the treatment of arthritic changes associated with advanced scaphoid disease. Patients who had scaphoid implant surgery since 1967 were studied. Preoperative and postoperative roentgenograms, charts, surgical pathology, and clinical evaluations were reviewed. A total of 55 cases of scaphoid implant arthroplasty were evaluated. A classification system was developed based on progressive severity, and treatment recommendations were developed for each stage of disease progression. Cystic and degenerative changes in contiguous carpal bones were evaluated. No evidence of cystic change could be found in 37 wrists, minimal changes were found in 9, moderate changes in 5, and severe changes in 4. There were no implant infections or fractures. Implant rotation occurred in two cases. Functional use of the hand with decreased pain was observed. It is important to detect and treat carpal instability, which may be associated with scaphoid disease. Cystic formation can be minimized by avoiding oversized implants, treating the associated carpal instability, bone-grafting preexisting cysts, and avoiding Kirschner wire fixation. By following treatment protocols as established in the classification system, the scaphoid implant can be successfully used in the management of scaphoid pathology.

Adult↗
PubMed1986

Bipolar implant shoulder arthroplasty.

A bipolar implant was designed by the author in 1975 for reconstruction of the severely arthritic shoulder. It has the advantage of not requiring glenoidal component fixation, but still provides an artificial joint interface. The ball of the humeral intramedullary stemmed component articulates with a polyethylene bearing within the glenoid cup component. This bipolar prosthesis was implanted in 15 shoulders of patients who presented severe arthritic shoulder disabilities. The follow up period averaged 41 months. Nine patients had rheumatoid arthritis, and five had osteoarthritis; all presented with severe pain and joint crepitation with loss of motion. A "shoulder score" system, based on the rating of pain, activities of daily living and range of motion, was devised to categorize the results obtained. Patients obtained greatly improved range of motion with good to excellent pain relief and very good functional restoration. Radiographically, the implant was well tolerated and there was no stem loosening. This procedure appears to be safe and efficacious for use in the severely arthritic shoulder.

Aged↗
PubMed1986

Bateman bipolar hip arthroplasty. A review of 44 cases.

A consecutive series of 71 Bateman hemiarthroplasties were performed in a single hospital over a 20-month period. Forty-four hips or 62% were available for review with an average follow up of 22 months. Of the 44 cases, the Bateman Universal Proximal Femur, original design was used in 40 acute, displaced femoral neck fractures, two failed Austin Moore prostheses, and two cases of femoral head osteonecrosis unassociated with fracture. The mean Harris hip score was 84.7%. Of the patients 93.2% had minimal or no pain. The range of motion was excellent and the dislocation rate was 1.8%. Morbidity was not increased compared to more conventional unipolar implant procedures. The Bateman Universal Proximal Femur (UPF) is felt to offer improved surgical results compared to Austin Moore and Thompson prostheses, and this may be due to the low friction inner bearing motion that occurs with this bipolar implant.

Aged↗
PubMed1986

Bone remodeling phenomena in flexible implant arthroplasty in the metacarpophalangeal joints. Long-term study.

The durability of any implant procedure is related to the host bone tolerance. This can be evaluated in part by measuring the cortical bone thickness around the device. The purpose of this study is to evaluate the long-term bone response to silicone implants at the metacarpophalangeal joint level in a series of 133 digits with a minimum of five years of follow-up evaluation. A method of bone morphometry that can measure cortical bone thickness on radiograms was used. Bone remodeling resulted in the formation of a newly formed cortical bony shell around the implant stems and maintenance of the shape of the cut end of the bone with thickening of the cortical bone at the metacarpal and phalangeal metaphysis. Thickening of the phalangeal midshaft was also present. A postoperative decrease of the metacarpal midshaft cortical bone thickness was related to the surgical reaming and remained permanently. Compared with the initial postoperative length, there was no shortening of the proximal phalanx and an average shortening of 9.1% in the metacarpal. The shape of the cortical bone in implant resection arthroplasty can be maintained and the bone thickness increased.

Adult↗
PubMed1986

Implant resection arthroplasty of the finger joints.

Flexible implant resection arthroplasty for the finger joints can provide rewarding results. The importance of indications, surgical considerations, and postoperative modalities are reviewed for the MP, PIP, and DIP joints.

Arthroplasty↗