Total Condylar Prosthesis Research Articles

Clinical Comparison of All-Polyethylene and Metal-Backed Tibial Components in Total Knee Arthroplasty

Based primarily on in vitro biomechanical studies, most total knee arthroplasty (TKA) manufacturers have abandoned the all-polyethylene tibial component (APT) in favor of the metal-backed tibial component (MBT). There is little clinical evidence to support this decision. A retrospective review of cemented TKA using the total condylar prosthesis was performed. One hundred eighteen patients with 131 TKAs were evaluated. Sixty-two of these knee prostheses had tibial components made entirely of polyethylene while 69 had the MBT. There were 13 cases of bilateral TKA in which the APT was used for one knee and the MBT for the other. All patients were examined by the authors for an average follow-up period of six years. Hospital for Special Surgery knee scores and a comprehensive roentgenographic evaluation were obtained. No significant difference was noted between the patients with APT and those with MBT, raising serious doubt on the need for the MBT in patients being treated with primary, cemented TKA.

Total Knee Arthroplasty in Rheumatoid Arthritis

From 1971 to 1985, 393 total knee arthroplasties (TKAs) were performed in patients for rheumatoid arthritis. Of these, 112 used polycentric prostheses and 131 used total condylar prostheses. One hundred seven of the patients with polycentric prostheses and 102 of the patients with total condylar prostheses were followed for a minimum of two years (average, 61 and 55 months, respectively). At the time of the latest examination, nine knees with polycentric prostheses required revision surgery: six for tibial component loosening and instability and three for patellofemoral pain. Five knees with total condylar prostheses required revision: one for chronic instability, one for a late posttraumatic patellar fracture, and three for late hematogenous infections. The total condylar prostheses with patellar resurfacing had better scores for pain (8.5 points) than the polycentric prosthesis without patellofemoral resurfacing (7.0 points). The total condylar prosthesis appeared more durable in terms of fixation, with no evidence of aseptic loosening of femoral or tibial components noted in this series thus far.

Total knee prosthesis (early results)

Between May 1990 and Agust 1991, 21 patients were treated by unilateral total knee prosthesis. Nine of them were treated by the kinematic condylar prosthesis with posterior cruciate retaining and twelve by total condylar prosthesis with posterior stabilization. Gonarthrosis in 18 patients (85.71%), traumatical osteoarthritis in 2 (9.5%7 and rheumatoid arthritis in 1 (4.7%) was found as a primary pathology. The average age of patients was 61 (57-72), mean follow-up was 9 months (1-16). The patients were evaluated by the knee scoring system of the knee society pre and postoperatively. . Preoperatively, mean knee score was 41.5 (24-60), mean functional score was 33.3 (0-55). Postoperatively it was 87 (82-91) for knee and 81.1 (64-95) for function.

The patellofemoral joint after total knee arthroplasty without patellar resurfacing.

One hundred total knee replacements with a total condylar prosthesis and without patellar resurfacing were followed for a minimum of two years. Eighty-four per cent of the knees were affected by osteoarthrosis. Graded according to the knee-rating system of the Hospital for Special Surgery, there were eighteen excellent, fifty-three good, eighteen fair, and eleven poor results. At the most recent follow-up, twenty-nine knees (29 per cent), nine of which were affected by rheumatoid arthritis, were still painful in the patellofemoral area. The height and weight of the patient definitely influenced the amount of patellofemoral pain postoperatively. Small patients who had osteoarthrosis were exceptionally free of pain, regardless of sex, age, or level of activity. It seems that the best approach to patellofemoral replacement includes resurfacing of the patella in all patients who have rheumatoid arthritis and in patients who have osteoarthrosis if they have preoperative patellofemoral pain, are more than 160 centimeters tall, weigh more than sixty kilograms, and have advanced changes in the patella at the time of the operation.

The incorporation of tibial allografts in total knee arthroplasty.

Twelve knees in ten patients had revision total knee replacement with insertion of an allograft for a large tibial defect. The knees were retrospectively evaluated at an average of thirty-two months (range, twenty-five to fifty-one months) by clinical examination, radiography, planar bone scintigraphy, and single-photon-emission computed tomography. The average age of the patients was sixty-two years (range, fifty-four to seventy-nine years). A constrained total-condylar prosthesis was used for all revisions. A contained tibial defect was present in five knees, and seven knees had an uncontained defect that was treated with a massive composite structural allograft, five of which were secured with internal fixation. The knee scores improved from an average of 51 points before operation to an average of 87 points post-operatively. Seven knees had a score of 85 points or more and were considered to have an excellent clinical result. Two knees had a good result, with scores of 77 and 72 points. One knee had another revision because of painful non-union of a medial structural graft, and the result in that knee was considered a failure. The average range of motion improved from 84 degrees to 105 degrees. There were no deep infections, and no graft showed evidence of fracture or collapse. Radiographs demonstrated complete incorporation of the graft in eleven of the twelve knees at an average of twenty-three months after operation. Single-photon-emission computed-tomography scans showed uniform activity in the area of the graft in four of the five knees that were studied.

FACTORS AFFECTING POSTOPERATIVE FLEXION IN TOTAL KNEE ARTHROPLASTY

In the review of 67 cases with total condylar (TC) prostheses, 59 with TC posterior stabilizers, 70 with TC prostheses modified with flat posterior tibial plateau, and 35 with porous-coated arthroplasty (PCA) prostheses, multiple cross-examinations of various factors for postoperative flexion were performed. Follow up was 2 to 9 years. In nearly all cases, no further improvement of flexion was noted after 1 year following surgery. The most influential factor for good postoperative flexion was intense physical therapy, leading to good suprapatellar pouch reconstitution. Residual flexion contracture was more frequent when the posterior cruciate ligament (PCL) was retained in the cases with significant preoperative flexion contracture. However, retention of PCL or preoperative ACL condition did not bear any significance to the ultimate flexion.

Total condylar knee replacement in patients who have rheumatoid arthritis. A ten-year follow-up study.

Eighty knee replacements with a total condylar prosthesis in patients who had rheumatoid arthritis were followed for ten years. At ten years, nineteen knees needed revision and sixty-one prostheses were still functioning. The major reasons for revision were loosening of the tibial component or late bacteremic seeding from another site. Radiolucency at the bone-cement interface adjacent to the tibial component was statistically related to malposition of the tibial component. According to the system of The Hospital for Special Surgery, the mean scores were 64 points preoperatively and 85 points postoperatively. Synovitis recurred in only 3 per cent of the knees. When revision, pain, or radiographic evidence of loosening were considered an indication of failure, the ten-year cumulative survival was 75 per cent.

The total condylar prosthesis. 10- to 12-year results of a cemented knee replacement.

Over a two-year period 104 patients had 130 knee arthroplasties performed with the total condylar prosthesis at the Hospital for Special Surgery. At a 10- to 12-year review 58 patients (74 knees) had survived and were available for detailed clinical and radiographic evaluation. Of these, 38 knees (51.3%) were rated as excellent and 27 (36.5%) good. There were three (4.0%) fair and six (8.2%) poor results. Five of the six had had revision operations. The success of this early pattern of prosthesis supports the continued use of methacrylate cement for knee arthroplasties.

Mechanisms of failure of the femoral and tibial components in total knee arthroplasty.

From 1974 to 1986, 1430 cemented primary total knee arthroplasties were available for analysis. These included 224 total condylar prostheses with a polyethylene tibial component, 289 posterior stabilized prostheses with a polyethylene tibial component, and 917 posterior stabilized prostheses with a metal-backed tibial component. There were 12 failures in the total condylar series including three infections (one early and two late), five loose tibial components, two loose femoral and tibial components, and two unstable arthroplasties. The posterior stabilized prosthesis with the polyethylene tibia demonstrated six failures including two loose tibial components, two loose femoral components, and one supracondylar femur fracture. The posterior stabilized prosthesis with the metal-backed tibial component was associated with seven failures including six infections (three early and three late) and one femoral loosening. No metal-backed tibial components have been revised for loosening. The overall failure rate in this series was 1.7% for all prostheses. The incidence of tibial loosening was 0.53% with an average time to failure of 4.7 years. The incidence of femoral loosening was 0.35% with an average time to failure of 2.0 years. Tibial loosening was related to error in technique: postoperative varus tibiofemoral alignment, varus tibial component position, and excessive tibial resection. The overall infection rate was 0.63% for all total knee arthroplasties, and all were secondary to gram-positive organisms. Presently, the posterior stabilized prosthesis with a metal-backed tibia is the authors' implant of choice. Technical error and infection are the major causes of failure.

Gait Laboratory Analysis of a Posterior Cruciate-Sparing Total Knee Arthroplasty in Stair Ascent and Descent

Successful posterior cruciate ligament-sparing total knee arthroplasty functions in an equivalent fashion to a contralateral normal limb during the mechanical stresses of stair ascent and descent. Motion and force plate analysis reveal highly symmetric gait patterns. Sagittal angles are greater than previously reported for the total condylar prosthesis and are nearly equal to those recorded for the age-matched normal population.

Total condylar knee arthroplasty. Implications of postoperative stability, evaluated by stress radiography

Knee sability and knee score were studied in 44 consecutive total knee replacements with the Insall/Burnstein Total Condylar Knee prosthesis. Knee stability was assessed by stress radiography. Statistical correlation was found between increasing antero-posterior laxity and increasing score on the New York Hospital for Special Surgery scoring scale, and between increasing antero-posterior laxity and increasing knee flexion ability. Tightness (total antero-posterior laxity <5mm) was associated with complaints of pain and compromised joint function.

Use of a total condylar knee prosthesis for treatment of osteoarthritis and rheumatoid arthritis. Long-term results.

Between May 1975 and December 1979, 113 patients had 153 arthroplasties using a total condylar knee prosthesis. Thirty patients (forty-two knees) died, and one (two knees) was lost to follow-up. Thirty-eight of these forty-four knees had been followed for more than two years, and none had had a revision. The remaining eighty-two patients (109 knees) were followed for an average of nine years (range, seven to 11.5 years). At the time of the latest examination, ten had had a revision for various reasons. For the ninety-nine knees that had the original prosthesis, the findings were compared with those of an evaluation that had been done four years postoperatively. The average over-all knee score was found to have decreased between the four-year and the latest follow-up evaluation, primarily because of a 7-point decrease in the score for function. The rate of infection was 0.6 per cent. The knees that had had patellar resurfacing had better over-all scores and better scores for pain than those that had not. This was particularly true in the patients who had osteoarthritis. The results of arthroplasty using a total condylar prosthesis appeared to be consistent and durable. Although there was a decrease in the quality of the functional result with increasing age, the patients reported consistent relief of pain.

Patellofemoral functional results and complications with the posterior stabilized total condylar knee prosthesis

The authors reviewed 73 knee arthoplasties performed with the Posterior Stabilized Total Condylar prosthesis, with an average follow-up period of 5.5 years. The function of the patellofemoral articulation was specifically analyzed. Patients with documented or suspected tibiofemoral problems were excluded. Using the Hospital for Special Surgery knee rating system, 48 knees (66%) had excellent, 20 had good (27%), and 5 (7%) had fair results. Patients with unilateral disease were able to negotiate stairs and transfer normally in 64% and 100% of the cases, respectively. The most frequent patellofemoral problem was impingement (21%), but reoperation was needed in only one patient. Stress fracture of the patella and subluxation were rare. A medial tilt of the patella on the axial view had no apparent ill effect. The patella was lowered 12 mm on average as a consequence of the standard bone resection sequence and insertion of the tibial component. The patella was significantly lower in patients with impingement than in normal joints. Routine complete patellofemoral resurfacing is advised in total knee joint arthroplasty. Complications are infrequent with appropriate prosthetic design and due technical care.

Hemodynamic changes during total knee replacement surgery with total condylar prosthesis.

Hemodynamic changes during total knee replacement surgery with total condylar prosthesis.

HEHODYNAMIC CHANGES DURING TOTAL KNEE REPLACEMENT SURGERY WITH TOTAL CONDYLAR PROSTHESIS

HEHODYNAMIC CHANGES DURING TOTAL KNEE REPLACEMENT SURGERY WITH TOTAL CONDYLAR PROSTHESIS

St Georg modular knee prosthesis. A two-and-a-half to six-year follow-up.

The St Georg modular knee replacement has been studied in 59 cases with an observation period ranging from 28 to 73 months. In 47% of the knees both compartments were replaced; five of the six poor results were in this group. These were revised to a hinge arthroplasty or, in one case, to an arthrodesis. Other complications were few and insignificant. There were no infections. We concluded that unicompartmental knee arthroplasty can be recommended when joint involvement is localised to one compartment only. With more generalised joint disease we prefer a semiconstrained total condylar prosthesis.

Total knee arthroplasty in chronic hemophilic arthropathy.

Nine total knee arthroplasties were performed in seven patients with either Hemophilia A (factor VIII deficiency) or Hemophilia B (factor IX deficiency) and followed for an average of 52 months. A total condylar prosthesis was used in eight virgin knees and a stemmed variable axis prosthesis was used in one revision case. All knees demonstrated the severe joint destruction and cartilage erosion characteristic of chronic hemophilic arthropathy. The average age at operation was 32 years. All patients were evaluated using the knee disability assessment of The Hospital for Special Surgery. All knees were postoperatively rated as either excellent or good. Pain, function, and range of motion were markedly improved. Postoperative radiographic alignment averaged 4 degrees of valgus with half of the virgin knees demonstrating 1 mm or less of non-progressive tibial radiolucency without clinical loosening. The only complication was hemarthrosis from 37 to 59 months postoperatively. This was thought to be secondary to trauma to residual synovium. Total knee arthroplasty in the hemophiliac is a viable alternative to conventional methods of treatment for chronic arthropathy and expectations for pain relief and functional gain can be high.

The Total Condylar Prosthesis

Forty knees with total condylar prostheses have been followed for ten years or more. There were five failures, one due to infection and four directly related to either improper selection or technical reasons. Thirty-five knees (87.5%) have a satisfactorily functioning arthroplasty after ten years. There were no loose components and no complete radiolucent lines. Technique and correct alignment are most important and, provided that the operation is correctly performed, conventional polymethyl methacrylate cement fixation is completely adequate. The absence of progressive adverse radiologic changes suggests that knee arthroplasties have a considerable life expectancy.

The total condylar knee prosthesis: a review of 71 operations.

Seventy-one operations are reviewed, in which knees were replaced with the total condylar prosthesis. The follow-up period ranged between 1 and 7 years, with an average of 3.25 years. Osteoarthritis was diagnosed preoperatively in 53 knees and rheumatoid arthritis in 18. The results obtained in cases of osteoarthritis were better than those in cases of rheumatoid arthritis. The prognosis was adversely affected by obesity, preoperative flexion contracture of 30 degrees or more, wound-healing problems, wound infection, and postoperative manipulation under general anesthesia. The overall results were excellent in 48% of cases (34 knees), good in 28% (20 knees), fair in 11.3% (eight knees), and poor in 4.3% (three knees). Failure was experienced in 8.4% of cases (six knees).

膝関節シミュレーターを用いた人工膝関節置換後の応力解析 : 歪みゲージ法による

In artificial joints, prosthesis loosening is influenced by its design and fixation technique with the bone. There are many designs of total knee prosthesis, including the hinged and nonhinged condylar type, in use today. In many recent clinical reports, sinking and loosening have been cited as a significant complication. For the purpose of making clear the relation between the loosening and the prosthesis design, a machine simulating the knee joint was manufactured and the relative deflections on the surface of the bone and between the component and the bone were measured by means of the strain gauge method utilizing the dynamic loading test. For the tests, GUEPAR prosthesis, Kinematic Rotating Hinge prosthesis, Total Condylar prosthesis and KOM Ceramic prosthesis were prepared. Fourteen different tibial components were also prepared including one compartmental, two anteriorly joined, eleven one-piece components with one, two, or three fixation pegs, all-plastic components or those with metal trays or with ceramic trays, for purpose of comparision. These prosthesis were fixed in femurs and tibia of cadaver bones with cementing. Strain gauges were glued to the surface of the around knee prosthesis, using cyanoacrylate instant cement. Maximum load was 100kg. In the GUEPAR prosthesis representative of the hinged type, the deflection was much larger at some distance from the knee joint, especially around the tip of the femoral stem, than in the periphery. In the Kinematic Rotating Hinge prosthesis, the hinged type admitted rotational movement, and the load was transmitted to the posterior cortical bone of the femur and tibia and compressive deflection occurred on these parts. The deflections were decreased around the tip of the stem. In the femoral component of the non-hinged type, KOM Ceramic prosthesis and Total Condylar prosthesis, the deflection around the periphery of the joint was not abnormally larger than the physiological state. In the tibial component, on the other hand, the compartmental component and anteriorly joined and one-piece components with short pegs deflected the most on the periphery of the anterior of tibia where the subchondral bones and trabeculate were weak and the cortical bones were thin. The least deflections occurred with the components with one or three strong pegs transmitting the load to the thick cortical bones. In fixing the tibial component, if it is designed to be loaded on the rigid cortical bone and is fixed so as to be supported by the rigid subchondral bone and cancellous bone of the plateau as well as by the rigid cortical bone on the medial and lateral sides or posterior slant surface and then loads are transmitted, it is considered that abnormal stress concentration can be decreased. The metal tray and ceramic tray prevent the deformation of the plastics and the stress concentration on the bone and cement.