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At least 289 records · Page 16Linked to original sources
PubMed2003

Anterior knee pain with a posterior-stabilized mobile-bearing knee prosthesis: the effect of femoral component design.

Femoropatellar problems have been reported with some designs of posterior-stabilized knee prostheses with fixed bearings; we report similar findings with a posterior-stabilized mobile-bearing prosthesis. A review of 184 patients (193 knees) who underwent placement of a Rotaglide (Corin, Cirencester, UK) posterior-stabilized prosthesis with patellar resurfacing showed that only 33 knees (17%) had complete absence of femoropatellar complaints after at least 1 year of follow-up evaluation. Femoropatellar grinding was noted in the other 160 knees; 65 were asymptomatic, 78 were mildly symptomatic, and 17 were severely symptomatic. Two patients refused secondary treatment; 15 underwent arthroscopic debridement. The only abnormal finding was intra-articular fibrosis surrounding the patellar implant. After arthroscopic debridement of the fibrosis, all patients reported immediate relief of their symptoms followed by recurrence within 6 to 9 months. Inappropriate trochlear design of the femoral implant appears to be the main determinant of femoropatellar problems in these patients. Encroachment on the trochlea by a broad intercondylar box with a sharp anterior edge appears detrimental to function irrespective of the presence or absence of bearing mobility.

Adult↗
PubMedDate not supplied

[Is unicondylar knee prosthesis a current possibility in primary management of varus gonarthrosis?--A prospective matched-pair study].

AIM: In the present study, we performed a follow-up investigation comparing middle-term results after unicompartmental and bicompartmental knee arthroplasties. MATERIAL AND METHODS: We used matched pairs with 18 patients in each group. The first group was treated with the unicompartmental slegde prosthesis (Type Wessinghage), the second with the cementless nonconstrained bicondylar prosthesis (Type Natural knee). The mean time of follow-up was 4.5 years. (SD +/- 0.6). The average age of the patients in both groups was 59 years (SD +/- 3). Both groups included 12 female and 8 male patients. All patients suffered from primary medial osteoarthritis of the knee. In all cases, the contralateral knee also had signs of manifest osteoarthritis. The determination and evaluation of the results of the investigation were made according to the score of the American Knee Society. We also reviewed the radiological findings concerning placement of the prosthesis, radiolucent lines, and patella position in the femoral shield. RESULTS: At follow-up examination, there were no significant differences in the knee score between the patients undergoing unicompartmental or total knee replacement. However, patients with the Wessinghage sledge tended to show better results. The mean knee score was 94.3 +/- 4.9 in the Wessinghage group and 91.9 +/- 8.3 in the Natural knee group. Evaluation of the radiographs revealed radiolucent lines in the group with total replacement. In contrast, in 7 of 18 patients with the unicompartmental prostheses we found radiolucent lines at the tibial component of 1 mm or more, which, however, did not cause clinical symptoms. CONCLUSION: Our results show, that the unicompartmental arthroplasty is still an effective method for the treatment of the osteoarthritis, especially concerning the conditions for possibly needed revisions.

Aged↗
PubMed1990

Failure of a knee prosthesis accelerated by shedding of beads from the porous metal surface.

A 61-year-old man who received a porous-metal-coated knee implant returned eight months later with chronic synovitis, instability, and loosening of his artificial joint. Subsequently, metal beads were detected in the joint space and soft tissues and were also embedded in the articulating surface of the tibial component. There was scoring of the tibial surface, and polyethylene wear particles were noted in the synovial and fibroconnective-tissue membranes, which had formed beneath the tibial component. Many particles were seen inside giant cells and macrophages. Failure in this case was probably accelerated by the granulomatous response in the soft tissue to wear particles. There was osteolysis rather than new bone growth at the interface with the tibial component. Analysis indicated that poor bead-bonding strength may have initiated the problem. Careful appraisal of the outcome from use of beaded porous-metal-coated devices and assurance of their adequate bonding strength are essential for further progress.

Foreign Bodies↗
PubMed2003

Fixation of a hydroxyapatite-tricalcium phosphate-coated cementless knee prosthesis. Clinical and radiographic evaluation seven years after surgery.

Miller-Galante II total knee arthroplasty (MG II TKA) was performed on 32 knees in 30 patients. On both the femoral and tibial components, the fibre-metal area was plasma-sprayed with hydroxyapatite-tricalcium phosphate (HA-TCP). The clinical and radiographic outcome was evaluated. A mean preoperative knee score of 26.0 +/- 18.6 (SD) increased to 97.5 +/- 3.5 and a mean pre-operative functional score of 21.7 +/- 15.0 (SD) increased to 83.4 +/- 12.4 at follow-up of seven years. Clear zones were common around the components at one month post-operatively but had completely disappeared after six months. An autopsy of a patient who underwent MG II TKA with HA-TCP two years previously, showed osteogenesis in all parts of the fibre-metal, and bone tissue comprised 77.7% of the interface. This coated prosthesis has good early fixation which is maintained at seven years with good clinical and radiographic outcomes.

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PubMed1991

Infected knee prosthesis: diagnosis with In-111 leukocyte, Tc-99m sulfur colloid, and Tc-99m MDP imaging.

Forty-one possible cases of infected total knee prostheses studied with indium-111-labeled leukocyte scintigraphy were retrospectively reviewed. Twenty-four of the prostheses were studied with technetium-99m methylene diphosphonate bone scintigraphy and 19 with Tc-99m sulfur colloid marrow scintigraphy. Nine prostheses were infected, and 32 were uninfected. The accuracy of combined labeled leukocyte and sulfur colloid marrow imaging (95%) was higher than that of labeled leukocyte scintigraphy alone (78%), bone scintigraphy alone (74%), or combined labeled leukocyte and bone scintigraphy (75%). The authors conclude that combined labeled leukocyte and sulfur colloid imaging is an accurate method for diagnosis of infected knee prostheses. In this series, this technique was superior to labeled leukocyte and bone imaging, alone or in combination.

Adult↗
PubMed1999

[Laxity and functional results of Miller-Galante total knee prosthesis with posterior cruciate ligament sparing after a 6-year follow-up].

PURPOSE OF THE STUDY: The preservation of the posterior cruciate ligament (PCL) was introduced in total knee arthroplasty to improve the quadriceps efficiency and the range of flexion in stairs. The purpose of this study was to determine if these goals were achieved with the Miller-Galante total knee prothesis and to assess the relation between knee laxity and function. MATERIALS AND METHOD: We assessed retrospectively the results of 48 consecutive Miller-Galante with PCL retaining. Four patients were excluded: 2 died, 2 lost to follow-up. Forty-four prostheses were evaluated in 38 patients mean aged 65 (33-79). The preoperative HSS score was 41 +/- 12.4 [21-63]. All the components were cemented with patellar resurfacing (25 metal-backed, 19 polyethylene). Stressed X-rays with Telos device were performed to assess frontal and antero-posterior laxity. All radiographic measurements were carried out with a digitizer (Orthographics). RESULTS: After 6 years of follow-up, 8 prostheses (18.1 p. 100) were already revised because of: 1) 3 excessive anterior tibial translations and severe polyethylene wear; 2) 5 femoro-patellar disorders. These last 5 knees (4 patellar metal-backed) had a greater patellar thickness [(25 mm +/- 1.2) (p = 0.01)]. The mean HSS knee score for the 36 remaining prostheses was 73.8 +/- 11.3 (35-92). Only 5 patients were able to climb stairs without support. The mean mechanical axis was 2.3 degrees in varus, but 81 percent of the knees were at 5 degrees around neutral position. The mean laxity in valgus was 4 degrees +/- 2.3 degrees [1-10], and 4.1 degrees +/- 2.1 degrees [1-9] in varus. The mean anterior tibial translation was 5.3 mm +/- 5 [1-17] and posterior laxity was 4.7 mm +/- 2.5 [1-10]. HSS knee score was lowered by 9 points when frontal laxity (valgus + varus) was greater than 5 degrees (p = 0.01), and by 9.8 points when posterior laxity was 5 mm or more (p = 0.02). The mean thickness of the patella was 22 mm +/- 2.3 [16-27]. DISCUSSION: These results were unsatisfactory considering the high revision rate and the low functional score observed despite of a correct implant positioning. The major challenge for PCL retaining (i.e. free stair climbing) was achieved in few cases. The wide range of posterior laxity underlined the difficulties to control PCL tension. On the other hand, PCL tension has to be controlled as it could influence knee function. Patello-femoral disorders was the main reason for revision surgery and an insufficient patellar bone resection may be contributive. Sagittal anterior laxity was the second reason for revision and it should be carefully detected as it could drive to catastrophic polyethylene wear. CONCLUSION: The advantages of PCL retaining were not demonstrated with this low constrained design. Surgical control of PCL tension could give a wide range of posterior laxity. Sagittal femoral-tibial laxity and femoro-patellar disorders should be detected before severe polyethylene wear. These results advocates for: 1) more congruent designs with PCL retaining or for PCL substituting designs, 2) improvement of patello-femoral design.

Adult↗
PubMed1987

Medical management of pneumococcal arthritis involving a knee prosthesis.

Septic arthritis involving prosthetic joints has been frequently reported, with Staphylococcus species being the pathogen most commonly noted. We report a case of septic arthritis of a prosthetic knee caused by Pneumococcus, a previously unreported pathogen in this condition, which uniquely responded to treatment with antibiotics.

Aged↗
PubMed2003

Quality of life and gait after unicondylar knee prosthesis are inferior to age-matched control subjects.

OBJECTIVE: Evaluation of quality of life, gait pattern, and muscle activity after implantation of unicondylar sledge prostheses in comparison with control group. DESIGN: A total of 17 patients were examined at an average follow-up of 21.5 mo after implantation of unicondylar sledge prostheses. In addition to clinical evaluation with different scores, our patients underwent three-dimensional gait analysis and surface electromyographic investigation of the lower limb and quality-of-life assessment using the Short Form-36 health questionnaire. The control group consisted of 11 healthy subjects. RESULTS: Statistical analysis showed significantly lower results for the patient group in the Hospital for Special Surgery score, the Knee Society score, the patella score, and the Visual Analog Scale for pain. In quality of life, significant differences could be found for the following items: physical functioning, role limitation because of physical problems, and bodily pain. Electromyographic activities during gait were significantly lower in the patient group, except for the rectus femoris and the tibialis anterior. Regarding gait analysis, the variables for ground reaction forces and stride length differed significantly, whereas maximum knee extension and flexion did not. CONCLUSIONS: Unicondylar knee replacement has failed to restore functional capabilities, quality of life, gait pattern, and muscle activity compared with healthy subjects of the same age. The assumption that unicondylar sledge prostheses preserve normal joint function must be questioned.

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