Purpose
To examine implant migration and articular behavior of primary total knee arthroplasty (TKA) at 10 years after index surgery and correlate to implant alignment.
Methods
Thirty-five patients ...underwent a cemented posterior stabilized total knee arthroplasty with a surgical objective of neutral alignment and were enrolled in a long-term radiostereometric analysis (RSA) study. At 10 years after surgery, patients were analyzed for implant migration using RSA as well as radiographic assessment of articular behavior at four positions of knee flexion. Implant position and alignment was measured on full-length radiographs. Patient demographics and reported outcomes were also collected.
Results
No difference between patient demographics or patient-reported outcomes were found. When categorized into neutral and varus groupings, no difference in migration was present. If alignment was considered as a continuous variable, there was no correlation between overall leg alignment and migration, however, migration increased with an increasing varus tibial alignment. Although contact location did not differ between neutral and varus groups through a range of motion, condylar liftoff was much more common in the varus group, of which all were lateral liftoff.
Conclusions
Increased tibial varus results in increased implant migration. Overall varus limb alignment is correlated with isolated lateral compartment liftoff, and liftoff occurs more commonly than in neutral aligned knees. The increased migration and liftoff raise concerns about the longevity of malaligned total knee replacements. If a goal of overall varus limb alignment is desired for TKA, the tibia should remain neutral.
Level of evidence
Level III.
The escalating socioeconomic burden of knee osteoarthritis (OA) underscores the need for innovative strategies to reduce wait times for total knee arthroplasty (TKA). The purpose of this study was to ...evaluate resource use, costs and health-related quality of life (HRQoL) across the continuum of care for patients with knee OA.
This was a prospective study of 383 patients recruited from a high-volume teaching hospital at different stages of care (referral, consultation and presurgery). Outcomes included health care resource use; costs captured from the health care payer, private sector and societal perspectives; HRQoL measured using the Western Ontario and McMaster Universities Osteoarthritis Index, the 12-Item Short Form Health Survey, and EuroQoL 5-Dimension 5-Level tool; wait times; and the proportion of referrals deemed suitable candidates for surgery.
The most commonly used conservative treatments were pharmacotherapy, exercise and lifestyle modification. Forty percent of patients referred for TKA were deemed not to be suitable candidates for surgery. The greatest proportion of costs was borne by the patient or private insurer; a small proportion was borne by the public payer. Across all stages of care, more than 60% of the total costs was attributed to productivity losses. HRQoL remained relatively stable throughout the waiting period (mean wait time from referral to TKA 13.2 mo) but improved postoperatively.
The suboptimal primary care management of knee OA calls for the development of innovative models of care. This study may provide valuable guidance on the design and implementation of a new online educational platform to improve referral efficiency and expedite wait times for TKA.
To optimize non-operative management and decision making surrounding TKR we created educational whiteboard videos for patients with knee OA. The purpose of this study was to pilot our educational ...videos with end-users (patients) to determine patients' experiences and perspectives regarding the content and clarity of videos and to better understand their potential impact on patient's health behaviour.
This was a mixed methods evaluation, using a qualitative descriptive approach, of patients attending their first consultation with an arthroplasty surgeon for TKR. We conducted in-depth semi-structured interviews with patients. Three members of the research team coded data independently, implementing a thematic analysis.
Thirteen participants were included. Participants indicated that the videos enhanced their confidence and clarity surrounding their decision to undergo TKR. The videos also addressed several knowledge gaps in their understanding of OA management. Barriers to uptake of the education were identified including limited access to PTs and the challenge of weight loss. Conclusions: The current educational intervention was valued by patients with knee OA. Implementation of these videos may have important implications for patients, providers, and our health care system.
IMPLICATIONS FOR REHABILITATION
Patients with knee OA referred by primary care physicians to arthroplasty surgeons have knowledge gaps that may influence their self-management and decision making surrounding their condition.
Educational materials can address these gaps and support patients in their understanding and management of their condition, which may have important downstream implications.
Barriers to accessing non-operative care including physiotherapy must be pre-emptively addressed to ensure that enhanced knowledge is met with improved access for patients.
Production of metal debris from implant wear and corrosion processes is now a well understood occurrence following hip arthroplasty. Evidence has shown that metal ions can enter the bloodstream and ...travel to distant organs including the brain, and in extreme cases, can induce sensorial and neurological diseases. Our objective was tosimultaneously analyze brain anatomy and physiology in patients with long‐term and well‐functioning implants. Included were subjects who had received total hip or hip resurfacing arthroplastywith an implantation time of a minimum of 7 years (n = 28) and age‐ and sex‐matched controls (n = 32). Blood samples were obtained to measure ion concentrations of cobalt and chromium, and the Montreal Cognitive Assessment was performed. 3T MRI brain scans were completed with an MPRAGE sequence for ROI segmentation and multiecho gradient echo sequences to generate QSM and R2* maps. Mean QSM and R2* values were recorded for five deep brain and four middle and cortical brain structures on both hemispheres: pallidum, putamen, caudate, amygdala, hippocampus, anterior cingulate, inferior temporal, and cerebellum. No differences in QSM or R2* or cognition scores were found between both groups (p > 0.6654). No correlation was found between susceptibility and blood ion levels for cobalt or chromium in any region of the brain. No correlation was found between blood ion levels and cognition scores. Clinical significance: Results suggest that metal ions released by long‐term and well‐functioning implants do not affect brain integrity.
The objective of this study was to identify the rate and risk factors for revision total knee arthroplasty (TKA) within the first 5 years postoperative. Our secondary objective was to identify the ...rate of additional surgical procedures and death.
We conducted a retrospective cohort study among patients in Ontario, Canada who underwent an elective, primary TKA between April 1, 2007, and March 31, 2014, for osteoarthritis. We excluded patients under 40 years and who had undergone a TKA within the previous 15 years. Our final study cohort included 94,193 patients. We reported the proportion of the study cohort who experienced revision surgery within 2 and 5 years of the primary TKA; secondary surgery within 5 years. We conducted Cochran-Armitage tests for trends to assess changes in the proportion of patients who experienced each of the study outcomes, and multivariable logistic regressions to evaluate predictors of a revision TKA.
There were 3,112 (3.3%) patients who had a revision within 5 years, and 1,866 (2.0%) within 2 years of their primary TKA. 3,316 (3.5%) had a secondary surgery (0.6% patellar resurfacing; 1.6% manipulation; 1.3% synovectomy; 0.5% washout; 0.9% debridement). Lower age, men, lower income, higher comorbidity score, depression, previous arthroscopy, lower surgeon volume, and general anesthesia were all significant positive predictors of revision.
In our study cohort, 2.0% of patients had a revision TKA within 2 years, and 3.3% within 5 years of their primary TKA. Preoperative identification of risk factors may reduce the future prevalence of revision TKAs.
We previously demonstrated the feasibility and clinical effectiveness of a web-based assessment following total hip or total knee arthroplasty. The purpose of the present study was to conduct an ...economic evaluation to compare a web-based assessment with in-person follow-up.
Patients who had undergone total joint arthroplasty at least twelve months previously were randomized to complete a web-based follow-up or visit the clinic for the usual follow-up. We recorded travel costs and time associated with each option. We followed patients for one year after the web-based or in-person follow-up evaluation and documented any resource use related to the joint arthroplasty. We conducted cost analyses from the health-care payer (Ontario Ministry of Health and Long-Term Care) and societal perspectives. All costs are presented in 2012 Canadian dollars.
A total of 229 patients (118 in the web-based group, 111 in the usual-care group) completed the study. The mean cost of the assessment from the societal perspective was $98 per patient for the web-based assessment and $162 per patient for the usual method of in-person follow-up. The cost for the web-based assessment was significantly lower from the societal perspective (mean difference, $-64; 95% confidence interval CI, $-79 to $-48; p < 0.01) and also from the health-care payer perspective (mean difference, $-27; 95% CI, $-29 to $-25; p < 0.01).
The web-based follow-up assessment had a lower cost per patient compared with in-person follow-up from both societal and health-care payer perspectives.
Abstract The purpose of this study was to determine agreement between responses on electronic and paper versions of the WOMAC and SF-12(v2) questionnaires following total hip and total knee ...arthroplasty. Patients completed both electronic and paper questionnaires with a one week interval in-between. The order in which they completed the two versions was randomly assigned. A total of 53 patients completed the study, with a mean age of 69 years (range 50–90 years). The intraclass correlation coefficients (ICC) were high, indicating excellent agreement (WOMAC ICC = 0.96, 95% CI 0.94–0.98), SF-12 (PCS) ICC = 0.95, 95% CI 0.92–0.97; SF-12 (MCS) ICC = 0.92, 95%CI 0.86–0.95). Online data collection may be substituted for the traditional paper method with no significant effect on the criterion validity of the questionnaires.
Gender-specific total knee replacement design is a recent and debated topic. We determined the survivorship and clinical outcomes of a large primary total knee arthroplasty cohort, specifically ...assessing any differences between gender groups. A consecutive cohort of 3817 patients with 5279 primary total knee replacements (3100 female, 2179 male) with a minimum of 2 years followup were evaluated. Preoperative, latest, and change in clinical outcome scores (WOMAC, SF-12, KSCRS) were compared. While men had higher raw scores preoperatively, women had greater improvement in all WOMAC domains including pain (29.87 versus 27.3), joint stiffness (26.78 versus 24.26), function (27.21 versus 23.09), and total scores (28.35 versus 25.09). There were no gender differences in improvements of the SF-12 physical scores. Men had greater improvement in Knee Society function (22.1 versus 18.63) and total scores (70.01 versus 65.42), but not the Knee Society knee score (47.83 versus 46.64). Revision rates were 10.2% for men and 8% for women. Women demonstrated greater implant survivorship, greater improvement in WOMAC scores, equal improvements in SF-12 scores, and less improvement in only the Knee Society function and total scores. The data refute the hypothesis of inferior clinical outcome for women following total knee arthroplasty when using standard components.
Level of Evidence:
Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.
Periprosthetic joint infection (PJI) continues to be one of the leading causes of failure following total hip arthroplasty (THA). The objectives of the study were to (1) determine the minimum 2-year ...infection-free survivorship of 2-stage revision THA, (2) determine the causative organisms for repeat 2-stage revision THA, and (3) characterize the results of failed 2-stage revisions and evaluate patient-reported outcome measures (PROMs).
A retrospective chart review was completed for patients who underwent 2-stage revision THA for PJI. Prospective data were collected on each patient, including demographics, causative organisms, complications, and type of reoperation. The PROMs, including Harris Hip Score, 12-item Short-Form Health Survey, and Western Ontario and McMaster Universities Osteoarthritis Index scores were obtained prior to 2-stage revision THA surgery and annually as part of standard clinical and radiographic follow-up.
A total of 328 patients who underwent a 2-stage revision THA for a PJI were included in the study (mean age 67 years range, 28 to 90, mean body mass index of 30.6 range, 15 to 57). The overall infection-free survivorship for 2-stage revision THA was 73.8% at a minimum of 2 years (range, 2 to 20). Overall, 194 (59.1%) patients who had successful infection eradication underwent a 2-revision THA only. The most common single organisms infected were Staphylococcus aureus (12.5%) and Staphylococcus epidermidis (11%). Higher reoperation rates were found in cases with methicillin-resistant Staphylococcus aureus and polymicrobial infections. All PROMs showed statistical improvement from preoperatively to the latest follow-up appointment.
Two-stage revision THA is associated with a good success rate in the treatment of PJIs at mid-term to long-term follow-up. Polymicrobial and methicillin-resistant Staphylococcus aureus infections are poor prognostic factors, making the eradication of infection more difficult. The management of PJIs continues to be one of the most important orthopaedic challenges to treat.
Bone loss remains an anticipated challenge in revision total knee arthroplasty (rTKA). Recent efforts to enhance rTKA fixation and stability have focused on metaphyseal implants, namely cones and ...sleeves. We sought to compare cone and sleeve implant survivorship in rTKA.
One hundred eighty patients who underwent rTKA with metaphyseal implants from 2005 to 2018 were retrospectively reviewed. A total of 83 cones (22 femoral, 62 tibial) and 121 sleeves (58 femoral, 63 tibial) were identified. The mean age at the time of surgery was 72 years (range 43-97). Intraoperative Anderson Orthopaedic Research Institute bone loss classifications included the following: type 2A (25), type 2B (98), and type 3 (81). Mean follow-up was 41 months.
Revision-free survival for cones was 91.3% vs 92.2% for sleeves (P = .29). Twelve knees (4 cones, 8 sleeves) underwent irrigation, debridement, and polyethylene exchange with metaphyseal implant retention for acute postoperative periprosthetic joint infection (PJI). Development of chronic PJI warranted removal of 7 cones (8.4%), 6 of which were initially placed as part of a 2-stage revision TKA. Eight sleeves (6.6%) were removed for PJI, with all initially placed during a second stage reimplantation. In the absence of infection, survival was 100% and 99.1% for cones and sleeves, respectively. One sleeve was revised for periprosthetic fracture.
Metaphyseal cones and sleeves offer equally durable survivorship in revision TKA. PJI was the most common mode of implant failure in this series. Importantly, no cases of cone or sleeve aseptic loosening were observed.
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