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PubMed2003

Mobile and fixed bearing total knee prosthesis functional comparison during stair climbing.

OBJECTIVE: The purpose of this investigation is to determine the functional performance of the mobile bearing total knee replacement prosthesis as compared to the fixed bearing type total knee replacement prosthesis. DESIGN: Kinematics, kinetics, and electromyography data were gained from 10 patients with mobile bearing and 10 patients with a fixed bearing posterior stabilized Insall Burstein II total knee replacement during ascending and descending stairs. A control group of 10 normal subjects, matched by sex and age, was also analysed. BACKGROUND: No significant biomechanical differences in patients with different total knee replacement designs have been reported from level-walking studies. Slightly better performance of posterior retaining with respect to cruciate sacrificing total knee replacement designs have been claimed from stair climbing studies. Only one study has been conducted regarding mobile versus fixed bearing total knee replacement assessed by gait analysis. This study did not show any biomechanical differences between the two groups. METHODS: Motion analysis was used to quantify the knee kinematics, kinetics, and electromyography (right and left longissimus dorsi, gluteus medius, rectus femoris, biceps femoris, semitendinosus, gastrocnemius and tibialis anterior muscles) during stair ascent and descent. RESULTS: The mobile bearing group demonstrated a reduced knee extensor moment during stair climbing and descending, and a reduced knee adductor moment during stair climbing. When ascending stairs, most of the mobile bearing patients show a peak knee flexion and a peak knee flexion moment at the late stance phase during the double support period. This kinematic and kinetic pattern is absent in normal subject. Both mobile bearing and fixed bearing groups showed abnormal electromyography patterns in both descending and ascending. CONCLUSIONS: During stair climbing, the mobile bearing design demonstrates a different kinematic pattern to the fixed bearing total knee replacement. Lower limb compensatory mechanisms seemed to be adopted particularly by the mobile bearing patients during ascending stairs. RELEVANCE: Total knee replacement patient with mobile bearing design can feel excessive femoro-tibial motion during daily living activities such as stair climbing and descending. Proprioceptive control of this tibio-femoral translation is needed as demonstrated by the lower limb compensatory mechanism. This data suggest that antero-posterior constraint structures (ligamentous or mechanical) are important to obtain reproducible knee kinematics.

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PubMed1991

[Early functional and anatomic results after total condylar knee prosthesis implantation].

The results of total knee replacement in 30 patients have been analyzed. Total knees were implanted during 1990, and the shortest follow-up time after the operations amounted to 6 months. All 30 total condylar prosthesis were of Insall-Burstein posterior stabilized design. The average age of the operated patients was 61 years. Osteoarthritis caused serious knee damage in 21 patients and was the indication for the operation; in 7 patients it was rheumatoid arthritis; in 1 patient synovitis villonodularis; and severe posttraumatic osteoarthrosis in 1 patient. In 18 patients axial knee deformity was noted prior to operation in the sense of valgus or varus. The continuous passive motion machine was used in the postoperative treatment of all patients. Clinically acceptable results were obtained in 90%. Wound healing complications were noted in 2 patients. Full axial deformity correction was achieved in all the patients with a full extension and flexion of over 90 degrees in the operated knees. Preliminary results after the implantation of this type of prosthesis are very encouraging and justify it's further routine use.

Adult↗
PubMed1991

[Problems of infected knee prosthesis].

Our report is based on 47 infected knee arthroplasties that were revised and followed up in our hospital between 1984 and 1990. Various surgical and therapeutic management options are assessed. In our patient population our experience revealed that the two-stage reimplantation seemed to offer the best chances for management of infected knee arthroplasty. Infections with gram-negative bacteria tend to take a less favorable course than those caused be gram-positive organisms. A division into categories of infected knee joints is presented and the complexity of problems related to the diagnosis is discussed.

Amputation, Surgical↗
PubMed1986

Correlation between clinical examination and quantitative gait analysis in patients operated upon with the Gunston-Hult knee prosthesis.

A group of 21 patients with total knee joint replacement was followed-up ten years after the operation. The clinical assessment including pain, range of motion, muscle strength and knee function was related to an objective gait analysis which included ground reaction force patterns and joint angular motion. This method of gait analysis not only confirmed in an objective way the impression from the clinical assessment but also provided a more accurate gradation of the results. The method is applicable to patients with weight bearing problems.

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PubMed1990

Accelerations due to impact at heel strike using below-knee prosthesis.

The acceleration in the sagittal plane of the prosthetic tube at heel strike in normal walking was measured in five healthy amputees with their definitive below-knee prosthesis, every subject using six different prosthetic feet, wearing sport shoes as well as leather shoes. The experiments were carried out in the rehabilitation centre "Het Roessingh", Enschede, The Netherlands. Maximum accelerations were extracted from the acceleration-time-signal. Mean acceleration maxima of all subjects were calculated for each foot-shoe combination to eliminate the individual influence of the subjects. In the axial direction the maximal accelerations demonstrate a clear difference among the prosthetic feet and the shoes, while in dorsoventral (tangential) direction the inter-individual variation in the acceleration extremes dominates the difference between the types of footwear. In comparison with non-amputees the magnitude of the maximal axial acceleration at heel strike does not differ significantly.

Amputees↗
PubMed2004

Knee kinematics with a high-flexion posterior stabilized total knee prosthesis: an in vitro robotic experimental investigation.

BACKGROUND: An analysis of contemporary total knee arthroplasty reveals that, on the average, patients rarely flex the knee beyond 120 degrees. The biomechanical mechanisms that inhibit further flexion after total knee arthroplasty are unknown. The objective of the present study was to investigate the capability of a single design of a fixed-bearing, high-flexion posterior stabilized total knee arthroplasty system (LPS-Flex) to restore the range of flexion to that of the intact knee. METHODS: Thirteen cadaveric human knees were tested, with use of a robotic testing system, before and after total knee arthroplasty with the LPS-Flex prosthesis. The passive path and the kinematics under an isolated quadriceps force of 400 N, under an isolated hamstring force of 200 N, and with these forces combined were determined. Posterior femoral translation of the lateral and medial femoral condyles and tibial rotation were recorded from 0 degrees to 150 degrees of flexion. RESULTS: The medial and lateral condyles of the intact knee translated posteriorly from full extension to 150 degrees, reaching a mean peak (and standard deviation) of 22.9 +/- 11.3 mm and 31.9 +/- 12.5 mm, respectively, under the combined muscle forces. Following total knee arthroplasty, the amount of posterior femoral translation was lower than that observed in the intact knee. At 150 degrees, approximately 90% of the intact posterior femoral translation was recovered by the total knee replacement. Internal tibial rotation was observed for all knees throughout the range of motion. The cam-spine mechanism engaged at approximately 80 degrees and disengaged at 135 degrees. Despite the absence of cam-spine engagement, further posterior femoral translation occurred from 135 degrees to 150 degrees. CONCLUSIONS: The tibiofemoral articular geometry of the intact knee and the knee after total knee arthroplasty with use of the LPS-Flex design demonstrated similar kinematics at high flexion angles. The cam-spine mechanism enhanced posterior femoral translation only at the mid-range of flexion. The femoral component geometry of the LPS-Flex total knee prosthesis may improve posterior tibiofemoral articulation contact in high flexion angles.

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PubMed2003

Conversion of a fused knee with use of a posterior stabilized total knee prosthesis.

BACKGROUND: Typically a hinged or condylar constrained prosthesis is recommended for total knee arthroplasty in a fused knee, to substitute for the absent or deficient collateral ligaments. The purpose of this study was to evaluate the stability and clinical results after the use of a posterior stabilized prosthesis in the conversion of a fused knee to a total knee arthroplasty. METHODS: Thirty-six patients (thirty-six knees) with a mean age of 39.2 years underwent conversion of a fused knee to a total knee arthroplasty with a posterior stabilized prosthesis. The mean duration of ankylosis had been 24.5 years. Clinical and radiographic evaluation was carried out preoperatively; at six weeks and three, six, and twelve months postoperatively; and annually thereafter. The mean duration of follow-up was 7.7 years. RESULTS: The mean preoperative Hospital for Special Surgery knee score of 60 points improved to 83.2 points at the final follow-up examination. Twenty-two knees were pain-free, and the remaining fourteen were mildly painful after prolonged walking. The mean amount of active flexion in the entire group was 77.7 degrees. The extension lag in the entire group averaged 12.5 degrees. Complications included necrosis of the skin edges in eighteen knees (50%), a rupture of the quadriceps tendon in two patients, and a pyogenic infection in two. No prosthesis required revision because of clinical or radiographic loosening. CONCLUSIONS: We believe that when the soft-tissue sleeves in a previously fused knee are carefully preserved intraoperatively, they can provide adequate stability after total knee arthroplasty with a posterior stabilized prosthesis. Therefore, we believe that use of that type of prosthesis is a reasonable alternative to the use of a more constrained implant in the treatment of this condition.

Adult↗
PubMed2004

[False aneurysm of the lateral superior genicular artery. A complication after the implantation of a knee prosthesis].

Arterial complications after total knee arthroplasty are rare. If the formation of a false aneurysm does occur, it usually affects the popliteal artery. We report the case of an 77 year old female with a false aneurysm of the lateral superior genicular artery. The patient was suffering from gonarthrosis and received a duocondylar knee replacement without resurfacing of the patella. Postoperatively, she reported anterior knee pain and a revision of the joint with lateral release was carried out. In the third postoperative week, a painful swelling in the lateral and superior aspect of the knee occurred. A scintigraphic investigation with enrichment in the early period was misinterpreted as infection. Ultrasonographic and angiographic investigations gave the right diagnosis of a false aneurysm. In the same angiographic investigation, the aneurysm could be cured by coil embolisation. The interval between the operation leading to the problem and the formation of the aneurysm, as well as the low incidence of this complication, made it hard to diagnose. Ultrasonographic and angiographic examinations allow for proper diagnosis in cases of unclear painful swellings. When dealing with an arterial complication following total knee arthroplasty, a specialized radiologist or vascular surgeon should be consulted immediately.

Aged↗
PubMedDate not supplied

Knee prosthesis in rheumatoid patients.

Total knee arthroplasty is a reliable means to improve the quality of life not only in osteoarthritis, but also in rheumatoid patients. Specific aspects, like the low mechanical quality of bone tissue, the contemporary damage of several joints and the higher risk of complications, have to be taken into account in rheumatoid arthritis. The experience with 24 prostheses in 21 rheumatoid patients is reported and confirms the efficacy of this operation. Among the technical details discussed, stress is placed on the conservation of the posterior cruciate ligament, the use of cement, the procedure of patelloplasty instead of prosthetic replacement. Careful preoperative planning is required and resections, especially in the tibia, should be economical. The evaluation of the results according to the protocol of the America Knee Society shows a satisfactory increase both of the articular score (average from 36 to 88) and the functional score (average from 34 to 68).

Aged↗
PubMed1990

[Knee prosthesis in 1990. Apropos of a 15 years' experience].

Knee prostheses have been greatly refined over the past ten years. A range of prostheses with various designs are currently used. On the basis of their 15-year experience, the authors assess the role of the various prostheses. Among partial prostheses, the femoropatellar prosthesed have a restricted place and are reserved for isolate degenerative diseases of the femoropatellar joint without femorotibial involvement: 34 such prostheses have been used by the authors and the department of professor J.H. Aubriot in Caen. About 75% of the results are satisfactory, with a follow-up in time of more than 8 years in 6 of these cases. Single-compartment prostheses are used in degenerative disease on an angular deviation, condylar necrosis or post-traumatic lesions, as far as one compartment only is affected. The authors have inserted 115 "Lotus" uni-compartment prostheses at Saint-Louis hospital. 75.6% of these have very good or good results maintained in time, as 72% of the 32 prostheses still produce satisfactory results after 5 years or more. The greatest progress was made above all for total prostheses replacing all the compartments of the knee. Hinge prostheses now have only rare indications as first-intention prostheses due to the immediate vital risks and to the high percentage of suppuration and long-term loosening. Sliding prostheses have taken an increasingly dominant place. The authors used Insall's total condylar prostheses, which do not preserve the posterior cruciate ligament, until 1983. 45 prostheses were followed up for 1 to 10 years, showing 71% of very good or good results.(ABSTRACT TRUNCATED AT 250 WORDS)

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PubMed1989

The effect of the CAT-CAM above-knee prosthesis on functional rehabilitation.

Five, rehabilitated, unilateral above-knee amputees (average age, 34.4 years) using quadrilateral sockets were converted to Contoured Adducted Trochanteric-Controlled Alignment Method (CAT-CAM) sockets to determine the effect on ambulatory function. Patients were evaluated before and after conversion for subjective acceptance, gait deviations, relative femoral shaft inclination, coronal-plane hip abduction torque, and ambulatory metabolic demands. The CAT-CAM socket was subjectively rated superior by four patients. Most gait deviations improved or disappeared. Femoral shaft inclination angles improved an average of 6.5 degrees toward adduction by roentgenographic measurements in four patients. Film records suggest that the compensatory lateral trunk lean, seen in patients with quadrilateral sockets, diminished after conversion. These four patients increased their customary gait velocities, and all showed a reduction in the quantity of oxygen consumed per meter traveled by up to 50%.

Amputation, Surgical↗
PubMed1986

Experience with the variable axis knee prosthesis.

In an evaluation of 245 variable axis total knee arthroplasties, no significant deterioration of results were found five to nine years after implantation. The patellar problems originally reported diminished with the use of a patellar button, widening of the flange on the femoral component and the increased use of lateral retinacular release. The local complications were: severe patellar problems, 6.9%; ligamentous laxity, 2.9%; aseptic loosening, 1.2%; deep infections, 2.0%; supracondylar fractures, 1.2%; peroneal nerve palsy, 1.6%.

Aged↗