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At least 19 recordsLinked to original sources
PubMed1996

Posterior stabilized knee prosthesis for total knee replacement in patients with prior patellectomy.

OBJECTIVE: To determine the outcome of total knee replacement using a posterior cruciate-substituting knee prosthesis in patients who have undergone previous patellectomy. DESIGN: A cohort study, with a follow-up ranging from 2 to 9 years. SETTING: A university-affiliated institution specializing in elective orthopedic surgery. PARTICIPANTS: Sixteen patients with arthritis of the knee who had had patellectomy. All agreed preoperatively to a prolonged postoperative follow-up. INTERVENTION: A cemented posterior cruciate-substituting knee replacement. MAIN OUTCOME MEASURES: Stair climbing ability, the Hospital for Special Surgery knee rating system for clinical results and a radiologic rating using a zonal system. RESULTS: Clinical rating was 69% good or excellent. Eighty-one percent of patients could use the replaced knee as the lead leg on stair climbing. Minor radiolucency, mostly single zone only, was found. Two patients required revision because of pain, but no obvious reasons for this pain were found at operation. CONCLUSION: In the absence of a patella, a posterior cruciate-substituting prosthesis gives reasonable results.

Aged↗
PubMedDate not supplied

[Long-term results of the Blauth knee prosthesis--current status of hinged knee prostheses].

AIM: Currently there is widespread use of unconstrained knee arthroplasty even in severe deformities of the knee. In order to ascertain the value and future of constrained knee prostheses, we have assessed the results of the Blauth knee prosthesis and compared them with the results of unconstrained knee prostheses. METHODS: In a retrospective analysis we examined 227 Blauth knee prosthesis implantations performed between 1985 and 1997. Using endpoints of prosthesis removal, infection and aseptic loosening, the 10-year survivorship analysis was evaluated. RESULTS: The analysis shows a 10-year survivorship of 90.1 % using aseptic loosening or infection as an endpoint and 96.2 % using removal as an endpoint. CONCLUSION: The first designs of constrained knee prostheses were associated with a high failure rate, while more recent designs like the St. Georg knee prosthesis and the Blauth knee prosthesis show long-term results similar to condylar designs. Since there has been a large increase of knee endoprosthesis implantations in the last years, a constrained knee prosthesis with excellent long-term results remains a valuable implant in cases of revisions and difficult knee arthroplasty.

Arthroplasty, Replacement, Knee↗
PubMed2005

[Gait changes encountered after a total knee prosthesis with or without posterior cruciate ligament preservation].

PURPOSE OF THE STUDY: We wanted to check whether the differences in joint kinematics between the normal and prosthesis knee, with or without preservation of the posterior cruciate ligament, have an effect on knee flexion-extension during gait and on gait performance. MATERIAL AND METHODS: A control group of nine subjects was compared with two groups of subjects with total knee prostheses, with (n = 10 patients) or without (n = 6 patients) preservation of the posterior cruciate ligament. Gait was studied on flat ground at three different walking speeds. We measured the principal temporospatial gait parameters as well as knee flexion and extension angles using continuous electrogoniometry. Non-parametric statistical tests were used to analyze data due to the small number of subjects in each group. RESULTS: The flexion-extension cycles were different between the control group and the prostheses groups, but there was no difference between the two prostheses groups. Measurements made during gait confirmed this result, demonstrating a modification of the temporospatial parameters and a decrease in knee flexion during weight bearing in the prostheses groups compared with the control group. The statistical analysis demonstrated a correlation between these two results. DISCUSSION: The individual nature of gait parameters hindered data analysis. Indeed, there are many different ways to walk "normally". We were however able to demonstrate the following points. The theoretical differences in joint kinematics between prostheses with or without preservation of the posterior cruciate ligament did not have any effect on gait. There were however significant differences between the control group and the prostheses groups, and these differences depended on walking speed. The most interesting results concerned the changes in the weight-bearing phase. Flexion during this phase was related to walking speed and was decreased in amplitude in both prostheses groups. This lesser amplitude in knee flexion probably affected the quality of gait because it was correlated with decreased temporospatial parameters related to gait performance. CONCLUSION: This decreased amplitude of flexion during gait, which cannot be expected from motion measurements without weight bearing, can be explained by an interaction between joint kinematics, the musculoligamentary system and the locomotor schema.

Arthroplasty, Replacement, Knee↗
PubMed1991

[Functional result and outcome of total condylar knee prosthesis].

Total condylar knee prosthesis is gradually proving fully reliable. It is an "all or nothing" type of surgery, with either good or bad results depending on the occurrence of complications, notably tibial decementation. With the experience acquired it may be said that the much dreaded wearing off of polyethylene components is not responsible for failures of total knee prosthesis.

Humans↗
PubMed1981

Total knee prosthesis. Evolution of the principles and technique and initial results obtained with the total-condylar knee prosthesis "with posterior stability".

The principles and details of the surgical technique for the insertion of total knee prostheses are presented, in particular the methods of dealing with the soft tissues, the correction of deformities, and the sequence and details of making the bone sections. The authors deal in detail with the technical characteristics of their modification of the Total-Condylar prosthesis "with posterior stability" and discuss its advantages over the traditional design. The main advantages are increased range of movement and better functional capacity, stability, and distribution of load on the tibial component. No disadvantages have yet been encountered, so the authors recommend the use of this prosthesis in all cases, rather than only in selected cases.

Arthritis, Rheumatoid↗
PubMed1987

Treatment of the exposed knee prosthesis.

Ten knees with early tissue breakdown after knee arthroplasty resulting in exposed prostheses were treated with different plastic surgical techniques. Six knees were successfully covered: four using a gastrocnemius musculocutaneous flap, one using a fasciocutaneous flap, and one using split-skin grafts. Four knees failed: two using local skin flaps and two using split-skin grafts. A gastrocnemius musculocutaneous flap seems to provide a reliable coverage of the exposed knee joint.

Aged↗
PubMed1988

Alignment and long-term clinical results of a semiconstrained knee prosthesis.

In knee arthroplasty, component malpositioning seems to be a fundamental cause for failure. The degree of malpositioning is important. To investigate this degree, 86 of 137 knee arthroplasties performed with the Townley semiconstrained bicondylar prosthesis were examined after a mean follow-up period of 6.5 years (range, 5.0-8.5 years). Five arthroplasties were excluded because of aseptic loosening, but none of these showed malalignment in postoperative roentgenograms. Clinical results and the patients' reports on deterioration of prosthetic function were correlated with positioning of the prosthetic components. Total alignment between 6 degrees of varus and 7 degrees of valgus was associated with good clinical results. Total alignment of more than 7 degrees of valgus, anterior tilting of the tibial component, or positioning of the femoral component in more than 12 degrees of valgus correlated with relatively poor clinical results.

Adult↗
PubMed1984

A new knee prosthesis.

A new knee prosthesis is described, with a 7-8 year follow-up of 14 cases. It is a hinge prosthesis with cortex bearing flanged stems reproducing the shape of the bones, self orientating and self-fixing. It can be used with or without cement. The results are very satisfactory.

Aged↗
PubMed1982

Total knee replacement with a variable axis knee prosthesis.

The Variable Axis Knee Prosthesis was designed to accommodate a wide range of problems in the knee and to minimize the complication of loosening. The results of the series, which now spans over seven years at this institution, have confirmed the effectiveness of the prosthesis in providing stability and firm fixation. Patellar alignment remains critical for optimum results. A wide variety of abnormalities, including failed prostheses, severe flexion contractures, arthrodesed knees, and severely osteoporotic bone, can be effectively managed utilizing this device. As with any other total knee prosthesis, the use of this prosthesis should be restricted to those knees with definite radiographic evidence of joint impairment in addition to significant symptoms. Relative contraindications include previous sepsis, neuropathic joint disease, and gross ligamentous incompetency. If these indications and limitations are adhered to, the results from knee replacement can be expected to equal or exceed those from total hip replacement over the long term.

Arthritis, Rheumatoid↗
PubMed1986

Evaluation of the Noiles hinged knee prosthesis. A five-year study of seventeen knees.

The Noiles hinged knee prosthesis has been reported to diminish sheer and tensile loading on the cement-bone interface. Theoretically, this should eliminate the complication of loosening, commonly reported in hinged total knee prostheses. We reviewed the cases of all of the patients who have been treated with the Noiles knee prosthesis at our institution. Eighteen knees in fourteen patients were available, seventeen of which were followed for more than five years. Although all of the prostheses did well initially, ten knees in eight patients (56 per cent) had failed by an average of thirty-two months postoperatively. These eight patients included four of the five who weighed more than ninety kilograms and all of those who had had a prior arthroplasty. The failures were clearly defined along the lines of sex distribution. Measurements on the radiographs showed a significant difference between sexes in the metaphyseal diameter and thus in the percentage of the femoral canal that was filled by the prosthesis and cement. We concluded that prosthetic design must incorporate cortical cement support to reduce stress at the cement-bone interface, especially in a medullary canal with a larger diameter.

Adult↗
PubMed1980

Preliminary report on postoperative results of newly designed stable total knee prosthesis.

A newly designed stable total knee prosthesis was made for the severely destructed knee. This prosthesis was named the Yoshino total knee prosthesis, and is a non-hinged type prosthesis consisting of a vitallium femoral component and a ultra-high molecular weight polyethylene tibial component. Clinical results of 127 Yoshino total knee arthroplasties showed the following characteristics: 1) good stability, and 2) good mobility. Stability was exceptionally good, and the results were the same as the hinged total knee prosthesis.

Adult↗
PubMedDate not supplied

Total knee replacement with the Kodama-Yamamoto knee prosthesis.

Since 1970, 170 knees have been operated upon using the Kodama-Yamamoto knee prosthesis. Of these 127 had the revised Mark-II prosthesis and of this group 91 cases have been followed for more than a year. Interim results suggest that the total knee score has improved. on the average, from 38 points preoperatively to 74 points after one year. A single early complication involved loosening of the prosthesis in a case of knee infection. Except for this case, no loosening and no radiolucent lines have been observed. Methacrylate bone cement is known to be harmful to bone and soft tissues, and our basic and clinical studies reveal that results improve when the total knee replacement is done without using cement.

Arthritis, Rheumatoid↗
PubMed1989

The posterior stabilized knee prosthesis.

The posterior stabilized knee prosthesis is a versatile and durable prosthesis with an excellent clinical record. It was designed to increase range of motion, improve stair climbing, and prevent posterior tibial subluxation.

Humans↗
PubMed1993

Output space tracking control for above-knee prosthesis.

The control of a knee joint in an active above-knee prosthesis has been designed using the Lyapunov tracking method. A simulation of locomotion was done to prove that the tracking control in output space is a valuable real time control method for artificial legs. The data used for simulation was collected in able-bodied subjects while they walked on a powered treadmill. Human volunteers were braced with an ankle splint (limiting dorsi- and plantar flexion) and with a knee cage (limiting knee movements to the lateral plane). We studied the achieved tracking of the prescribed knee motion, deviations of the thigh movement from the prescribed trajectory, maximal angular deviations from the desired trajectory and the power consumption as functions of a limited maximal knee torque and a damping constant in the knee actuator. We found that the use of output tracking method is suitable for the design of appropriate hardware of an above-knee prosthesis and for real-time control.

Artificial Limbs↗
PubMedDate not supplied

The total condylar knee prosthesis: the first 5 years.

The total condylar knee prosthesis evolved from previous experience with other prostheses at the Hospital for Special Surgery. This evolution includes patellar resurfacing. Subsequent modifications have led to the total condylar knee prosthesis II (a cruciate substituting prosthesis), and the total condylar knee prosthesis III (a TCP II with increased constraint). The surgical technique requires ligamentous balance with correction of preoperative deformity by a soft-tissue release. Subsequently a standard operation is performed. Four hundred and sixty-one knees were reviewed with a minimum of one year follow-up and a maximum of 5 years. Seventy-five per cent were osteoarthritic knees. Using the Hospital for Special Surgery Knee Rating Scale, the results were excellent in 312 knees (68%), good in 109 knees (23.5%), fair in 18 knees (4%) and poor in 22 knees (4.5%). Osteoarthritic knees (excellent or good 93.5%) did slightly better than rheumatoid knees (excellent or good 87%). Complications include 6 infections, 6 subluxations and 10 cases of component loosening. There were 15 reoperations (3%). The results approach total hip arthroplasty in quality and so far have not deteriorated with time.

Adult↗
PubMed1992

Combined nuclear and digital subtraction contrast arthrography in painful knee prosthesis.

The evaluation of a painful knee prosthesis remains a difficult problem for both orthopaedic surgeons and radiologists. We have compared digital subtraction arthrography with nuclear arthrography in 7 patients with a painful knee prosthesis. Three patients showed a loose tibial component, demonstrated by both digital subtraction and nuclear arthrography. All 3 underwent revision of their prosthesis. One patient had an equivocal digital subtraction arthrogram and negative nuclear arthrogram, while both studies were negative in the 3 remaining patients. Nuclear arthrography is a simple procedure and can provide useful additional information when combined with digital subtraction arthrography.

Aged↗
PubMedDate not supplied

The mechanical testing of a sliding meniscus knee prosthesis.

A 3-component sliding meniscus knee prosthesis was tested mechanically to evaluate the direct loads and the anteroposterior and mediolateral bending moments on the prosthetic components during the loading phase on a pendulum prosthesis testing machine. The bending moments changed with variation of the component positions. Tilting the tibial plateau produced the greatest change in lateral bending moment on the femoral component but alteration in plateau rotation or femoral tilting produced little change in the low values of the 2 bending moments. It is necessary to ensure that the tibial component is positioned horizontally on the tibial plateau, but it is not necessary to be concerned about the angle of the femoral component to the vertical or the misalignment rotationally of the tibial component. The load ideally passes through the condylar component to the tibia much more centrally than if it were a constrained prosthesis system during the loading range, reducing the likelihood of displacement of the 2 fixed components.

Biomechanical Phenomena↗