Success Of Total Knee Arthroplasty Research Articles

Total knee arthroplasty for osteoarthritis of the knee

The indication, preoperative condition, surgical technique and postoperative rehabilitation of total knee arthroplasty for osteoarthritis are summarized. I think the point of contributing to the success of total knee arthroplasty are to discuss the preoperative condition, to know well the instrument, to do the accurate osteotomy and to obtain the correct soft tissue balancing.

Rotational instability and malrotation after total knee arthroplasty

Total knee arthroplasty has become the standard treatment for various disabling disorders of the knee and has proven long-term success. Surgical technique and prosthetic design have evolved to produce consistent and excellent results. Despite the current success of total knee arthroplasty, complications remain.

Long-term results of total knee arthroplasty after the use of soft tissue expanders.

The success of total knee arthroplasty can be jeopardized by poor wound healing. In the current study, the results of knee arthroplasty after soft tissue expansion were reviewed retrospectively in 27 patients (29 knees) at risk for problematic healing. The incidence of wound complications was recorded for all patients after the expansion procedure and the arthroplasty. A Knee Society score also was calculated at the latest evaluation. Minor wound complications occurred after 21% (six of 29) of the tissue expansion procedures and after 18% (five of 28) of the subsequent arthroplasties. One major wound complication occurred during tissue expansion necessitating abandonment of the planned arthroplasty. No major wound complications occurred in those patients who underwent knee arthroplasty. At an average followup of 34.4 months, the average Knee Society score was 83.7 points. The results of the current study show that the technique of soft tissue expansion before total knee arthroplasty in patients at high risk for wound healing problems can successfully prevent catastrophic wound complications after the arthroplasty procedure and can avoid the need for disfiguring soft tissue reconstructions.

Rising from chair after total knee arthroplasty

Objective. This study was performed to determine the biomechanics of chair rising by patients after successful total knee arthroplasty (TKA). Design. Relative full body joint positions and ground reaction forces were measured by a motion analysis system and two force plates. Background. Chair-rise produces increased joint forces and moments compared with level walking, and it is difficult to rise from a chair for most patients with neurological or musculoskeletal abnormalities. Previous motion studies of patients after TKA had focused on gait analysis and stair climbing. Methods. Twelve patients after successful TKA were studied while performing sit-to-stand transfer from a chair at four chair heights without the use of arm rests. The results of this group were compared with those of 12 healthy elderly subjects and 14 osteoarthritic patients before TKA. Results. Compared with the healthy elderly group during chair rising, the patients after TKA had increased horizontal mass center velocity, increased vertical hip joint forces, the maximum sound-side hip extension moment, but decreased vertical mass center velocity. Conclusion. Compensatory mechanisms of chair rising were adopted by the arthritic patients before and after TKA. The mechanisms include increased forward body bending and more weight shift on the sound side.

The accuracy of femoral intramedullary guides in total knee arthroplasty

Of the technical factors important in achieving a successful total knee arthroplasty, limb alignment has been demonstrated to be most influential in determining implant survival. Intramedullary femoral guide systems rely on placement of the intramedullary rod along the anatomic axis of the femur. In this article, the accuracy of the femoral intramedullary guide is investigated using radiographs and a mathematical model. The femoral anatomic axis was drawn on 40 consecutive, preoperative, 3-ft standing radiographs. Using a mathematical model, the potential angular error in the distal femoral cut from aberrant placement of the intramedullary rod was estimated. Calculated values correlated with measured values from plain radiographs and an intramedullary guide template. The anatomic axis was found to exit the distal femur at an average of 6.6 mm medial to the center of the femoral notch. Substantial malalignment error resulted from minor malposition of the intramedullary rod. Most books and diagrams demonstrating the use of intramedullary guides indicate that the entry point is at the center of the femoral notch. These results show that the true entry point is medial to the center of the notch, and rod placement error results in excessive valgus alignment. Preoperative drawing of the anatomic axis on a 3-ft or 18-inch anteroposterior radiograph is recommended. The results both demonstrate the importance of correct use of the guide and heighten cognizance among surgeons performing total knee arthroplasty as to the limitations of the intramedullary guides.

Proprioception following total knee arthroplasty with and without the posterior cruciate ligament

Proprioception was measured in two groups of patients following successful total knee arthroplasty (TKA). In one group, the posterior cruciate ligament was retained and an unconstrained cruciate-retaining total knee component was used; in the other group, the posterior cruciate ligament was excised and a cruciate-substituting design was implanted. Threshold to detection of passive motion was quantified as a measure of proprioception. The degree of preoperative arthritis was objectively classified according to Resnick and Niwoyama. There was no difference in threshold to detection of passive motion in cruciate-retaining versus cruciate-substituting TKA. In patients with a moderate grade of arthritis before surgery, the postoperative scores were virtually identical. When the grade of preoperative arthritis was severe, patients with cruciate-substituting TKAs performed significantly better than those with cruciate-retaining TKAs.

Total knee arthroplasty in a group of patients less than 45 years of age

The long-term follow-up evaluation of total knee arthroplasty (TKA) in patients under age 45 is reviewed. One hundred three knees in 67 patients who had an average follow-up period of 7.2 years were retrospectively reviewed. Fifty-eight percent of the patients had rheumatoid arthritis, and 29% had juvenile rheumatoid arthritis. Thirteen percent of the patients had post-traumatic arthritis, avascular necrosis, hemochromatosis, or lupus. The results demonstrate that the success of TKA in this partient population are comparable to those for TKA in the elderly.

Accuracy of the short radiograph in the measurement of the tibiofemoral angle

To determine which axes on the ‘short’ radiograph (36 cm × 43 cm) correlate best with the corresponding axes on the ‘long’ radiograph (36 cm × 130 cm), 100 long anteroposterior radiographs were taken postoperatively following total knee arthroplasty. The central 43 cm of the long radiograph were used to simulate a short radiograph of the knee. For the femur, the short-radiograph axis drawn from the midpoint at the proximal end to a point 10 cm above the joint line had the highest coefficient of correlation ( r = 0.97) with the anatomical axis of the femur on the long radiograph. For the tibia, the short-radiograph axis drawn from the midpoint of the distal end of the tibia to a point 10 cm below the joint line had the best correlation ( r = 0.93) with the anatomical axis of the tibia on the long radiograph. The tibiofemoral angle created by these two axes was 5.3°, which, in comparison to eight other axis combinations tested on the short radiographs, correlated best ( r = 0.94) with the mean tibiofemoral angle observed on the long radiographs. We find this angle to be a satisfactory indication of the tibiofemoral angle on a long radiograph. This finding will allow a more accurate determination of the optimal tibiofemoral angle that is so important to the long-term success of total knee arthroplasty.

Intramedullary alignment in total knee arthroplasty following proximal femoral instrumentation: an anatomical and radiographic study

Correct component alignment is essential for the success of total knee arthroplasty. The use of intramedullary alignment in the femur has become the current standard for correct placement of the femoral component. The accuracy of this system is dependent on the degree to which the intramedullary guide rod approximates the anatomical axis of the femur. Cases in which the guide rod cannot be completely seated, such as after a femoral endoprosthesis, can result in increased differences between the anatomical axis and the guide rod axis. In these cases, additional referencing systems, such as extramedullary alignment or intra-operative radiography, may be useful to increase the accuracy of component position.

Principles of total knee arthroplasty.

Experience over the last two decades has demonstrated total knee arthroplasty to be a durable and reliable procedure for relief of pain and improved function. Proper patient and prosthesis selection are important for optimal results. Operative keys to a successful total knee arthroplasty include satisfactory exposure, soft tissue balance, proper alignment, and reconstruction of the patellofemoral joint.

Total Knee Arthroplasty Following Patellectomy

Eleven patients with a previous patellectomy and primary total knee arthroplasty (TKA) had chart reviews, recent clinical examinations, evaluation of roentgenograms, rating of knee arthroplasty on a standard scale, and quantitation of quadriceps and hamstring torque using an isokinetic dynamometer. Good to excellent results were present in only five of the 11 knees studied, compared with 11 of 11 patients in a control group with intact patellae. Quadriceps and hamstring torque and strength were diminished relative to the control groups. Factors that correlated with a success or failure of TKA in patients with previous patellectomy included: number of previous knee operations, three or less; presence of severe arthritic changes roentgenographically; and quadriceps performance of greater than 40 ft-lb at 30 degrees/second testing speed. Patients without patellae who lack these favorable prognostic factors for a successful TKA should be strongly considered for bracing or primary arthrodesis, rather than knee arthroplasty.