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Background: Although initial reports on posterior cruciate ligament-retaining total knee arthroplasty in patients with rheumatoid arthritis have been encouraging, a high rate of late instability necessitating revision has been reported recently. The purpose of the present prospective study was to analyze the results of posterior cruciate ligament-retaining total knee arthroplasty in patients with rheumatoid arthritis.Methods: Seventy-two posterior cruciate ligament-retaining total knee arthroplasties in fifty-one patients with rheumatoid arthritis were studied prospectively. All procedures were performed with the Miller-Galante I prosthesis. Eighteen patients (twenty-four knees) died before the eight-year follow-up and one patient (two knees) was lost to follow-up, leaving forty-six knees (thirty-two patients) for review. These forty-six knees were evaluated clinically (with particular attention to posterior instability) and radiographically at annual intervals for a mean of 10.5 years (range, eight to fourteen years).Results: Forty-four (95%) of forty-six knees had a good or excellent result at a mean of 10.5 years. However, nine (13%) of the original seventy-two knees had revision of the implant, with six of the revisions performed because of failure of a metal-backed patellar component. The rate of survival at ten years was 93% 4% with femoral or tibial revision for any reason as the end point and 81% 5% with any reoperation as the end point. There was no aseptic loosening in any knee. Posterior instability was identified clinically and/or radiographically in two (2.8%) of the original seventy-two knees; both unstable knees were in the same patient.Conclusion: Posterior cruciate ligament-retaining total knee arthroplasty yielded satisfactory clinical and radiographic results in patients with rheumatoid arthritis at intermediate-term follow-up (mean, 10.5 years). Therefore, we believe that it remains an excellent treatment option for these patients. [ABSTRACT FROM AUTHOR]

Background: Heterotopic ossification (HO) is a known complication following total hip arthroplasty. Radiation is an effective prophylaxis, but an optimal protocol has yet to be determined. We performed a randomized, double-blinded clinical trial in high-risk patients to determine the efficacy of 400 vs 700 cGy doses of radiation., Methods: One hundred forty-seven patients undergoing total hip arthroplasty and at high risk for HO at an urban medical center were randomized to receive either a single 400 or 700 cGy dose of radiation postoperatively. High risk was defined as a diagnosis of diffuse idiopathic skeletal hyperostosis, hypertrophic osteoarthritis, ankylosing spondylitis, or history of previous HO. Radiation was administered on the first or second postoperative day. A single blinded reviewer graded radiographs taken immediately postoperatively and at a minimum of 6 months postoperatively using the Brooker classification. Progression was defined as an increase in Brooker classification. Operative data including surgical approach, implant fixation, revision surgery, and postoperative range of motion data were also collected., Results: A significantly greater portion of patients who received the 400 cGy dose demonstrated progression of HO than patients who received the 700 cGy dose. There were no wound complications. No preoperative factors were associated with a higher rate of progression. Patients who progressed had less flexion on physical examination than patients who did not progress, but this was not clinically significant., Conclusion: Seven hundred centigray was superior to 400 cGy in preventing HO formation following total hip arthroplasty in high-risk patients and may be the more effective treatment in this population. Further studies comparing 700 cGy to dosages between 400 and 700 cGy may help to clarify if a more optimal dose can be identified., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Problems with the patellofemoral articulation are the most common causes of failure after total knee arthroplasty. However, there are few reports describing outcomes following isolated revision of the patellar component., Methods: Forty knees with a Miller-Galante I prosthesis underwent isolated patellar revision (with or without lateral retinacular release). The Hospital for Special Surgery knee scores were collected prospectively, and radiographs made preoperatively and at the time of the final follow-up were analyzed with respect to alignment, component position, and patellar tracking. Particular attention was given to patients who had a reoperation or repeat revision and who had clinical or radiographic evidence of failure of the patellar revision., Results: At a mean follow-up of sixty-two months, fifteen (38%) of the forty knees that had had an isolated revision of the patellar component failed a second time. Eight of them required a total of twelve additional operations at a mean of forty-nine months after the patellar revision. Three of the failures were severe enough to require revision of two or more of the components. Of the twenty-five knees that had not failed, the average Hospital for Special Surgery knee score at the time of the final follow-up was 87 points. Of the seven knees that did not undergo reoperation but were deemed to be failures on the basis of the patients' symptoms, the average Hospital for Special Surgery knee score at the time of the final follow-up was 72 points., Conclusions: Isolated patellar revision, with or without concurrent lateral retinacular release, was associated with a high rate of reoperation and a relatively low rate of success. Elements of the implant design and component alignment contributed to the patellar component failure; both should be scrutinized carefully in patients who are seen with this problem, prior to proceeding with isolated revision of the patellar component of a total knee arthroplasty., Level of Evidence: Therapeutic study, Level IV (case series [no, or historical, control group]). See p. 2 for complete description of levels of evidence.

One hundred two patients with 131 consecutive cementless total knee arthroplasties that retained the posterior cruciate ligament were followed up prospectively. The average age of the patients was 58 years (range, 32-75 years). The mean followup on the surviving knee arthroplasties was 11 years (range, 7-16 years). The patellar component was metal-backed in the first 112 (85%) knees, cementless all-polyethylene in the last 17 (13%) knees, and two knees had a prior patellectomy. Forty-four metal-backed patellar components (48%) were revised; nine were loose, and 35 had polyethylene wear through. Thirteen femoral components (12%) were revised because of femoral abrasion from a failed metal-backed patellar component. No other femoral component was revised, loose, or had osteolysis develop. Nine (8%) tibial components had failure of ingrowth; eight have been revised. Partial radiolucencies occurred in 53% of the tibias. Thirteen (12%) small osteolytic lesions developed, all around screws or screw holes in the tibial components. At an average of 11 years followup, cementless fixation yielded mixed results: cementless femoral fixation was excellent and metal-backed patellar components had a 48% patellar revision rate. Cementless tibial components had an 8% aseptic loosening rate and a 12% incidence of small osteolytic lesions. Based on these results, the authors have abandoned cementless fixation in total knee arthroplasty.

One hundred seventy-two consecutive cemented Miller-Galante-I total knee arthroplasties in 155 patients were compared with 109 consecutive cemented Miller-Galante-II total knee arthroplasties in 92 patients. The average followup was 11 years (range, 8-15 years) and 9 years (range, 8-10 years), respectively. Of the 172 Miller-Galante-I arthroplasties, there have been 21 revisions; 15 patellar revisions; two included femoral revisions attributable to abrasion. Six additional well-fixed femoral and tibial components were revised: two for early instability, one for pain, one for periprosthetic fracture, and two for infection. No component had aseptic loosening or osteolysis. Using revision or loosening of any components as the end point, the Kaplan-Meier 10-year survivorship was 84.1% +/- 4.1%. Of the 109 Miller-Galante-II arthroplasties, there have been no component revisions, no aseptic loosening, and no osteolysis. Using revision or loosening of any components as the end point, the Kaplan-Meier 10-year survivorship was 100%. The Miller-Galante knee systems showed excellent fixation with no loosening and no osteolysis at as many as 15 years. Additionally, there have been no component revisions for late instability at as many as 15 years. Finally, the high prevalence of patellofemoral complications with the Miller-Galante-I design has been obviated with the Miller-Galante-II design.

Sixty-two consecutive cemented modular unicompartmental knee arthroplasties in 51 patients were studied prospectively. At surgery, the other compartments had at most Grade 2 chondromalacia. The average age of the patients at arthroplasty was 68 years (range, 51-84 years). One patient was lost to followup and 10 died with less than 6 years followup. The average followup of the remaining 51 knees was 7.5 years (range, 6-10 years). The preoperative Hospital for Special Surgery knee score of 55 points (range, 30-79 points) improved to 92 points (range, 60-100 points) at followup; 78% (40 knees) had excellent and 20% (10 knees) had good results. The mean range of motion at followup was 120 degrees with 26 knees (51%) having range of motion greater than 120 degrees. One patient underwent revision surgery for retained cement, one patient underwent knee manipulation, and one patient underwent revision surgery at 7 years for opposite compartment degeneration and pain. Radiographically, 26 knees (51%) had at least one partial radiolucency. There were no complete femoral radiolucencies, but there were three complete tibial radiolucencies, all less than 2 mm. No component was loose as seen on radiographs. At final followup, five of the opposite compartments (10%) and three of the patellofemoral joints (6%) had some progressive radiographic joint space loss; this was less than a 25% loss in all but one knee component that was revised. At 6- to 10-years followup, cemented unicompartmental knee arthroplasty yielded excellent clinical and radiographic results. The 10-year survival using radiographic loosening or revision as the end point was 98%. Using stringent selection criteria, unicompartmental knee replacement can yield excellent results and represents a superb alternative to total knee replacement.

The results of 57 revision total knee arthroplasties performed for aseptic failure between 1984 and 1992 with a cemented posterior-stabilized or constrained condylar prosthesis were reviewed at follow-up examinations at a minimum of 36 and an average of 62 months (range, 36-120 months). The reason for revision was aseptic loosening of 1 or both components in 32 knees (56%), instability in 16 knees (28%), polyethylene wear and osteolysis in 4 knees (7%), supracondylar femur fracture in 2 knees (4%), and a failed allograft, pain, and arthrofibrosis in 1 knee each (5% total). The average age of the patients at the time of the revision was 74 years (range, 38-90), and the original diagnosis for the majority of patients was osteoarthritis (74%). All of the revision prostheses were cemented posterior stabilized or constrained condylar-type implants. Bone deficiencies were grafted with cancellous allograft in contained defects and cortical allograft in noncontained defects. Five knees were reconstructed with allograft-prosthesis composites. The average modified Hospital for Special Surgery knee score improved from 49 to 82 (100 points possible) at final follow-up evaluation (P < 0.001). Seventy-nine percent of knees were graded as good or excellent. Kaplan-Meier survivorship analysis predicted 94%+/-6.2% survival at 40 months and 75%+/-25% at 99 months. There were 4 clinical failures, 3 of which were related to residual instability in patients with a posterior-stabilized prosthesis. Complications (3 knees) were exclusively related to the extensor mechanism. Radiographically, overall knee alignment improved from 0.3 degrees varus to 3.0 degrees valgus. Fifty-six percent of tibial components were placed in slight varus alignment. Radiolucent lines occurred in 33% of knees, but there were no complete or progressive radiolucencies. Radiolucent lines were more prevalent adjacent to press-fit intramedullary femoral stems compared with cemented stems (P < .02), but the difference did not correlate with clinical or radiographic failure. The median bone defect score, as proposed by the Knee Society Committee on Bone Defects, was significantly greater in knees that were revisions of a failed cemented total knee arthroplasty compared with revision of a failed cementless total knee arthroplasty (P = .02) but was not correlated with clinical or radiographic outcome (P > .05).

Seventy-six consecutive infected total knee arthroplasties in 74 patients were treated between December 1981 and March 1990. The average follow-up period was 57 months (range, 24-121 months). No patients were lost to follow-up evaluation and 12 patients died from unrelated causes. Patients were classified, based on the duration of their symptoms prior to treatment, as acutely infected (< 2 weeks) or chronically infected (> 2 weeks). All knees were evaluated following surgical treatment with radiographs and Knee Society knee score assessment. Successful eradication of infection was defined as a knee without clinical evidence of infection for a minimum of 2 years. The initial treatment modality was successful in eliminating the infection in 69 of 76 patients (90%). Infection was eventually eradicated in 72 of 76 (94%) patients. The individual clinical result was found to be more dependent on a patient's medical and musculoskeletal status (patient class A, B, C) than on knee score or radiographic assessment. Careful treatment selection based on patient class and duration of infection can result in a predictable and successful result.

We evaluated the radiographic and functional status of a one-piece composite tibial component, designed to be inserted without cement, that was developed and used only at our institution. Thirty-six patients (thirty-seven knees) were managed with the component between November 1981 and September 1983, and none were lost to follow-up. When they were last seen, thirty-four (92 per cent) of the thirty-seven knees had a well-fixed tibial component, both clinically and radiographically. Eight patients (eight knees; 22 per cent) died. Eleven patients (eleven knees; 30 per cent) had a revision at an average of sixty-five months (range, four to ninety-five months) postoperatively. The reason for the revision was failure of a metal-backed patellar component in three knees, excessive wear of the polyethylene of the tibial component in one, a hematogenous infection in four, aseptic loosening of the tibial component in two, and chronic synovitis in one. The remaining seventeen patients (eighteen knees; 49 per cent) were seen for clinical and radiographic follow-up at an average of eleven years (range, nine to twelve years) after the operation. With removal of the implant as the end point, the cumulative rate of survival was 83 per cent at fifty-six months and 67 per cent at 108 months. Some of the failures were secondary to features of the prosthetic design that currently are considered to be inadequate, including a metal-backed patellar component and carbon-fiber-reinforced polyethylene. In the twenty-six knees in which the prosthesis had been retained, the implant was stable and the prosthesis-bone interface was unchanged as seen radiographically at the time of the most recent follow-up examination. This finding demonstrates that a porous ingrowth surface is capable of providing a secure interface for biological fixation over the long term.

A consecutive series of 62 Miller-Galante (Zimmer, Warsaw, IN) unicompartmental knee arthroplasties were evaluated. Patients had unicompartmental degenerative arthritis or osteonecrosis, a sagittal plane deformity of 15 degrees or less, and minimal patellofemoral involvement. The average age was 69, with osteoarthritis in 85% and osteonecrosis in 15%. Ninety-five percent were medial and 5% lateral compartment replacements. The Hospital for Special Surgery knee score averaged 56 +/- 11 before surgery and 96 +/- 5 at the final follow-up evaluation, with an average postoperative pain score of 48 +/- 2. Three patients suffered intra-operative or immediate postoperative tibial plateau fractures without apparent sequelae, one patient required a postoperative manipulation under anesthesia, and one patient required an arthroscopic debridement for retained cement in the posterior capsular space. Limb alignment was corrected to within 5 degrees of the neutral mechanical axis in 77%, with 19% undercorrected and 3% overcorrected. Seventy percent of knees showed at least a single radiolucent line. Complete radiolucent lines were noted about three tibial components (6%) and progressive partial radiolucency was noted about four additional components (8%).

Even though a complete understanding of electrical responses of bone has not been fully obtained, useful data toward this end have been gathered. The development of devices that use what is known about the bone's electrophysiologic properties has impacted patient care. Many health care professionals remain skeptical about the effects of electrical stimulation in bone healing. Therefore, further research is needed to help the practitioner formulate a more educated opinion on this form of therapy.

One hundred thirty-nine cemented and 132 cementless Miller-Galante total knee prostheses were followed between three and six years (average, 43-44 months). The fixation technique was based on patient age, bone quality, and ability to delay full-weight bearing. Clinical follow-up studies were possible on 116 cemented knees. Fifteen knees were lost because of death before the three-year follow-up study, and eight knees required component removal. One hundred twenty-three cementless knees were available for clinical follow-up studies; there were three deaths, and six failures required component removal. No cemented failure was due to fixation, and three cementless failures were due to lack of tibial ingrowth in two and pain of undetermined etiology in one. Preoperative knee scores were slightly significant with cemented knees averaging 48 points and cementless knees averaging 52 points. A similar significant difference was maintained at the final follow-up study. No significant differences were noted for pain, limp, or support scores. Average range of motion was similar in the two groups. Radiolucent lines about the femoral component were rare. Cementless tibial radiolucencies were partial in up to 20% of examined zones, and complete tibial tray radiolucency was seen in only three patients. No correlation between radiolucency and knee scores was seen.