Knee Society Objective Scores Research Articles

A Long-term Follow-up Study of Four Cases who Underwent Curettage and Autogenous Bone Grafting for Steroid-related Osteonecrosis of the Femoral Condyle

We performed curettage followed by autogenous bone grafting in several cases of steroid-related osteonecrosis of the femoral condyle, and reviewed the outcome of this procedure after a mean follow-up of 9.5 years. The number of patients was 4; the mean age at the time of the operation was 30.5 years. The mean Knee Society Objective Score was 52.5 before the operation and had increased to 87.5 at the time of the review. The pre-operative radiographic stages were stage 2 in 2 patients and stage 3 in the other 2 patients. Progression in the disease stage was observed in 3 patients. MRI revealed survival of the grafted bone in only one case, and collapse of the articular surface in all cases. In conclusion, though the clinical results showed improvement, the autogenous bone graft failed to answer the purpose of preventing the progression in disease stage.

Total knee arthroplasty for patellofemoral arthritis.

Multiple treatment methods have been advocated for patellofemoral arthritis. The purpose of the present study was to report on our experience with the use of total joint replacement for the treatment of primarily severe patellofemoral arthritis of the knee in patients more than fifty-five years of age. Between January 1980 and December 1994, thirty knee replacements were performed in twenty-seven patients for the treatment of arthritis that primarily involved the patellofemoral joint. The Ahlbück radiographic evaluation scale was used to grade the severity of arthritis; the mean score was 4.83 points (range, 4 to 5 points) for the patellofemoral compartment and 0.6 point (range, 0 to 1 point) for both the medial and lateral compartments. The patients included eighteen women and nine men who had a mean age of seventy-three years (range, fifty-nine to eighty-eight years). None of the patients had had any prior procedures on the knee, but all had been treated for a minimum of six months with nonoperative measures. The mean preoperative Knee Society score was 50 points (range, 20 to 64 points). At a mean duration of follow-up of eighty-one months (range, forty-eight to 133 months), there were twenty-eight excellent, one good, and one poor result. The mean Knee Society objective score was 93 points (range, 67 to 100 points). The poor result was in a patient who sustained a rupture of the patellar tendon postoperatively as the result of a fall, which necessitated a tendon reconstruction. Total knee arthroplasty was found to be a viable treatment option in patients more than fifty-five years of age with primarily severe patellofemoral disease.

Total knee arthroplasty in patients ≤50 years old

Thirty patients (30 knees) who underwent total knee arthroplasty at age ≤50 were reviewed. These patients were operated on between July 1, 1991, and May 1, 1995, with final follow-up evaluation at a mean of 86 months (range, 60-107 months). At final evaluation, 18 knees (60%) had excellent Knee Society objective scores, 11 knees (37%) had good scores, and 1 knee (3%) had a poor score. There were no statistically significant differences in Knee Society objective scores among the cemented group (mean, 88 points), hybrid group (mean, 88 points), and noncemented group (mean, 90 points). One patient (3%) had a revision because of unexplained pain. In the other knees, there was no radiographic evidence of progressive loosening, lucencies, or change in position or alignment of the prosthesis. Total knee arthroplasty of this design, at least for the time period studied (7-year mean follow-up), has a high rate of success in patients who are ≤50 years old. Copyright 2002, Elsevier Science (USA). All rights reserved.

Eliminating patellofemoral complications in total knee arthroplasty: Clinical and radiographic results of 121 consecutive cases using the Duracon system

This study reports the minimum 5-year follow-up of our experience with the Duracon Total Knee Arthroplasty System. A total of 121 consecutive total knee replacements using the Duracon system (Howmedica, Rutherford, NJ) were performed in 104 patients. Three patients died before the 5-year follow-up and were excluded from the final evaluation. The remaining 118 knees (101 patients) were assessed at a mean follow-up of 65 months (range, 60–80 months). The knee diagnoses were osteoarthritis in 97 patients, rheumatoid arthritis in 2 patients, osteonecrosis in 1 patient, and pigmented villonodular synovitis in 1 patient. The mean age was 70 years (range, 28–85 years). There were no reoperations for aseptic loosening, and there have been no reoperations for patellofemoral problems. At final follow-up evaluation, 112 knees (96%) had good or excellent results, and 6 knees (4%) had poor clinical results or went on to revision. For the surviving knees, the preoperative Knee Society objective score improved from a mean of 52 points (range, 20–72 points) to a final follow-up mean of 94 points (range, 66–100 points). Five knees needed reoperations: 2 knees in 1 patient because of acute hematogenous infection at 12 months, 1 knee because of a supracondylar femur fracture, 1 because of a patellar tendon rupture, and 1 to increase polyethylene thickness because of instability. The lack of aseptic loosening at the minimum 5-year follow-up compares favorably with any cemented or cementless series of knee replacement. The almost complete absence of patellofemoral complications in this series also indicates that the design changes, with particular attention to the trochlea design and patellofemoral contact throughout full flexion, have achieved their intended purpose. The results are encouraging at midterm, awaiting true long-term (15–20 years) follow-up.

Partial denervation for persistent neuroma pain around the knee.

The authors present the results of denervation procedures treatment for 70 patients with persistent knee pain after total knee replacement, trauma, or osteotomy. In patients with total knee arthroplasty, aseptic loosening, sepsis, ligamentous instability, malalignment, and polyethylene wear had to be systematically ruled out as the source of pain. In patients with nontotal knee arthroplasty, arthrosis, synovitis, ligamentous instability, and meniscal derangement had been excluded as a source of pain. All candidates for the procedure had a successful selective nerve block. Sixty of the 70 (86%) patients were satisfied with the denervation procedure as judged by direct questioning and a reduction in their preoperative pain visual analog score of 5 or more points. The average Knee Society score improved from a preoperative mean of 51 points (range, 40-62 points) to a followup mean of 82 points (range, 15-100 points). Forty-nine of 70 (70%) patients had final Knee Society objective scores greater than 80. There was no difference in patient satisfaction whether the followup period was less than 2 years or more than 2 years. Selective knee denervation is indicated in the management of intractable knee pain after exhaustion of traditional approaches to any structural or infectious etiologies and after successful selective nerve block.

Radiographic Characterization of Aseptically Loosened Cementless Total Knee Replacement

From January 1980 to December 1992, 655 cementless total knee arthroplasties with the PCA total knee system were done at the authors' institution. Thirty of these knees have been revised for aseptic loosening of either tibial or femoral components or both. Patients in the failed arthroplasty group were matched directly to a control group with well-functioning, stable and painless cementless total knee prostheses (Knee Society objective score, > 90 points). In this study, the authors analyzed any alignment differences between the 2 groups of knees. Special attention was given to the postoperative radiographs to evaluate for potential predictors of success versus failure. Multiple radiographic parameters were measured for each knee and included measures of frontal alignment, sagittal alignment, rotation, percent prosthetic coverage, and cortical thickness (denoted as the cortical-cancellous index). On univariate analysis, no individual radiographic parameter was significantly different in the failure group versus the control group. However, multivariate analysis indicated that certain combinations of abnormal parameters were significantly higher in the failed group than the control group. These parameters included measures of frontal and sagittal plane component alignment. The summated abnormal parameters per patient averaged 3.67 (range, 1-7) for the failure group and 1.80 (range, 0-7) for the control group.