Objective
To assess structural progression in knees with no/mild radiographic osteoarthritis (OA) (i.e., Kellgren/Lawrence K/L grades 0–2) that will undergo knee replacement during a 5‐year period; ...to assess differences in structural damage on magnetic resonance imaging (MRI) in knees with no/mild radiographic OA versus those with severe radiographic OA (i.e., K/L grades 3 and 4) at baseline; and to assess differences in pain levels between those groups.
Methods
All participants who underwent knee replacement from baseline to 60 months were drawn from the Osteoarthritis Initiative. MRIs were assessed for bone marrow lesions (BMLs), Hoffa synovitis, and effusion synovitis (i.e., hyperintensity signal changes in the fat pad and abnormal amount of capsular distension due to intraarticular joint fluid and/or synovial thickening) at baseline and at the time point before knee replacement (T0). The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Knee Injury and Osteoarthritis Outcome Score (KOOS) pain were used for pain characterization. WOMAC activities of daily living and KOOS quality of life were applied to characterize functional status of the included participants. Logistic regression was used to assess the association of no/mild radiographic OA with these MRI features and pain.
Results
Based on inclusion criteria, 181 knees were selected. Participants were predominantly female (57.8%) with a mean age of 64.4 years. A total of 51 knees (28.2%) had no/mild radiographic OA at baseline. Of these, 51.0% progressed to severe radiographic OA. No/mild radiographic OA knees showed higher odds of BMLs in the patellofemoral joint at baseline (odds ratio OR 7.92 95% confidence interval (95% CI) 3.45–18.16) and T0 (OR 9.44 95% CI 4.00–22.28) compared to severe radiographic OA knees. In addition, no/mild radiographic OA knees were associated with change from no pain to pain from baseline to T0 (adjusted OR 5.48 95% CI 1.25–24.00).
Conclusion
More than half of the knees with no/mild radiographic OA before knee replacement progressed to severe radiographic OA during 4 years of follow‐up. BMLs in the patellofemoral joint were more often seen among knees that had no/mild radiographic OA. Worsening pain status may contribute to knee replacement in knees with no/mild radiographic OA.
Objectives To compare the effect of a single infusion of zoledronic acid (ZA) with placebo on knee pain and bone marrow lesions (BMLs). Methods Adults aged 50–80 years (n=59) with clinical knee ...osteoarthritis and knee BMLs were randomised to receive either ZA (5 mg/100 ml) or placebo. BMLs were determined using proton density-weighted fat saturation MR images at baseline, 6 and 12 months. Pain and function were measured using a visual analogue scale (VAS) and the knee injury and osteoarthritis outcome score (KOOS) scale. Results At baseline, mean VAS score was 54 mm and mean total BML area was 468 mm2. VAS pain scores were significantly reduced in the ZA group compared with placebo after 6 months (−14.5 mm, 95% CI −28.1 to −0.9) but not after 3 or 12 months. Changes on the KOOS scales were not significant at any time point. Reduction in total BML area was greater in the ZA group compared with placebo after 6 months (−175.7 mm2, 95% CI −327.2 to −24.3) with a trend after 12 months (−146.5 mm2, 95% CI −307.5 to +14.5). A greater proportion of those in the ZA group achieved a clinically significant reduction in BML size at 6 months (39% vs 18%, p=0.044). Toxicity was as expected apart from a high rate of acute phase reactions in treatment and placebo arms. Conclusions ZA reduces knee pain and areal BML size and increases the proportion improving over 6 months. Treatment of osteoarthritis may benefit from a lesion specific therapeutic approach. Clinical trial registration number ACTRN 12609000399291.
Objectives To compare patient reported outcomes from before surgery to 52 weeks after surgery between individuals undergoing arthroscopic partial meniscectomy for traumatic meniscal tears and those ...for degenerative meniscal tears.Design Comparative prospective cohort study.Setting Four public orthopaedic departments in the Region of Southern Denmark. Participants were recruited between 1 February 2013 and 31 January 2014, and at one of the original four hospitals from 1 February 2014 to 31 January 2015.Participants Individuals selected from Knee Arthroscopy Cohort Southern Denmark, aged 18-55, and undergoing arthroscopic partial meniscectomy for a traumatic or degenerative meniscal tear (defined by a combination of age and symptom onset). Interventions Both participant groups underwent arthroscopic partial meniscectomy for a meniscal tear, with operating surgeons recording relevant information on knee pathology. Patient reported outcomes were recorded via online questionnaires.Main outcome measures Primary outcome was the average between-group difference in change on four of five subscales of the knee injury and osteoarthritis outcome score (KOOS). The four subscales covered pain, symptoms, sport and recreational function, and quality of life (KOOS4). A 95% confidence interval excluding differences greater than 10 KOOS points between groups was interpreted as absence of a clinically meaningful difference. Analyses adjusted for age, sex, and body mass index.Results 397 eligible adults (42% women) with a traumatic or degenerative meniscal tear (n=141, mean age 38.7 years (standard deviation 10.9); n=256, 46.6 years (6.4); respectively) were included in the main analysis. At 52 weeks after arthroscopic partial meniscectomy, 55 (14%) patients were lost to follow-up. Statistically, participants with degenerative meniscal tears had a significantly larger improvement in KOOS4 scores than those with traumatic tears (adjusted between-group difference −5.1 (95% confidence interval −8.9 to −1.3); P=0.008). In the analysis including KOOS4 score at all time points, a significant time-by-group interaction was observed in both the unadjusted (P=0.025) and adjusted analysis (P=0.024), indicating better self-reported outcomes in participants with degenerative tears. However, the difference between groups was at no time point considered clinically meaningful. Conclusions These results question the current tenet that patients with traumatic meniscal tears experience greater improvements in patient reported outcomes after arthroscopic partial meniscectomy than patients with degenerative tears.Trial registration ClinicalTrials.gov identifier NCT01871272.
To compare the gait of unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) patients with healthy controls, using a machine-learning approach.
145 participants (121 healthy ...controls, 12 patients with cruciate-retaining TKA, and 12 with mobile-bearing medial UKA) were recruited. The TKA and UKA patients were a minimum of 12 months post-operative, and matched for pattern and severity of arthrosis, age, and body mass index. Participants walked on an instrumented treadmill until their maximum walking speed was reached. Temporospatial gait parameters, and vertical ground reaction force data, were captured at each speed. Oxford knee scores (OKS) were also collected. An ensemble of trees algorithm was used to analyse the data: 27 gait variables were used to train classification trees for each speed, with a binary output prediction of whether these variables were derived from a UKA or TKA patient. Healthy control gait data was then tested by the decision trees at each speed and a final classification (UKA or TKA) reached for each subject in a majority voting manner over all gait cycles and speeds. Top walking speed was also recorded.
92% of the healthy controls were classified by the decision tree as a UKA, 5% as a TKA, and 3% were unclassified. There was no significant difference in OKS between the UKA and TKA patients (p = 0.077). Top walking speed in TKA patients (1.6 m/s; 1.3 to 2.1) was significantly lower than that of both the UKA group (2.2 m/s; 1.8 to 2.7) and healthy controls (2.2 m/s; 1.5 to 2.7; p < 0.001).
UKA results in a more physiological gait compared with TKA, and a higher top walking speed. This difference in function was not detected by the OKS. Cite this article: Bone Joint J 2016;98-B(10 Suppl B):16-21.
Background and purpose - Thresholds of implant migration for predicting long-term successful fixation of tibial components in total knee arthroplasty have not separated cemented and uncemented ...fixation. We compared implant migration of cemented and uncemented components at 1 year and as the change in migration from 1 to 2 years.
Patients and methods - Implant migration of 360 tibial components measured using radiostereometric analysis was compared at 1 year and as the change in migration from 1 to 2 years in 222 cemented components (3 implant designs) and 138 uncemented components (5 implant designs).
Results - 1-year maximum total point motion was lower for the cemented tibial components compared with the uncemented components (median = 0.31 mm 0.03-2.98 versus 0.63 mm 0.11-5.19 respectively, p < 0.001, mixed model). The change in migration from 1 to 2 years, however, was equivalent for cemented and uncemented components (mean SD 0.06 mm 0.19 and 0.07 mm 0.27 mm respectively, p = 0.6, mixed model).
Interpretation - These findings suggest that current thresholds of acceptable migration at 1 year may be better optimized by considering cemented and uncemented tibial components separately as higher early migration of uncemented components was not associated with decreased stability from 1 to 2 years.
A small posterior tibial slope (PTS) is generally recommended in posterior stabilized (PS) total knee arthroplasty (TKA). An unwanted anterior tibial slope (ATS), which can affect postoperative ...results, may be created in PS TKA because of the inaccuracy of surgical instruments and techniques, as well as high interpatient variability. We compared midterm clinical and radiographic results of PS TKAs with ATS and PTS performed on paired knees using the same prosthesis. One-hundred-twenty-four patients who underwent TKAs with ATS and PTS on paired knees using ATTUNE posterior-stabilized prostheses were retrospectively reviewed after a minimum follow-up period of 5 years. The mean follow-up period was 5.4 years. The Knee Society Knee and Function scores, Western Ontario and McMaster Universities Osteoarthritis Index, Feller and Kujalar scores, and range of motion (ROM) were evaluated. The preferred TKA out of ATS and PTS was also investigated. The hip-knee-ankle angle, component positions, tibial slope, posterior femoral offset, Insall-Salvati ratio, and knee sagittal angle were measured by radiography. There were no significant differences in the clinical results, including ROM, between TKAs with ATS and PTS preoperatively and at the last follow-up. Regarding patient preference, 58 patients (46.8%) were satisfied with bilateral knees, 30 (24.2%) preferred knees with ATS, and 36 (29%) preferred knees with PTS. There was no significant difference in the rate of preference between TKAs with ATS and PTS (
= 0.539). Except for the postoperative tibial slope (-1.8 vs. 2.5 degrees,
< 0.001), there were also no significant differences in the radiographic results, including the knee sagittal angle, preoperatively and at the last follow-up. The midterm outcomes were similar between PS TKAs with ATS and PTS performed on paired knees at a minimum of 5 years of follow-up. Nonsevere ATS did not affect midterm outcomes in PS TKA with proper soft tissue balancing and the current prosthesis of improved design. However, a long-term follow-up study is required to confirm the safety of nonsevere ATS in PS TKA. LEVEL OF EVIDENCE:: III.
Background
Balancing the relative advantages and disadvantages of unicompartmental knee arthroplasties (UKAs) against those for TKAs can be challenging. Survivorship is one important end point; ...arthroplasty registers repeatedly report inferior midterm survival rates, but longer-term data are sparse. Comparing survival directly by using arthroplasty register survival reports also may be inadequate because of differences in indications, implant designs, and patient demographics in patients having UKAs and TKAs.
Questions/purposes
The aims of this study were to assess the survivorship of UKA in the context of one large, northern European registry, and to compare the rates of survivorship with those of cemented TKAs performed for primary knee osteoarthritis during the same 27-year period.
Methods
From the Finnish Arthroplasty Register, we obtained the data for 4713 patients undergoing UKAs for primary osteoarthritis (mean age, 63.5 years; minimum followup, 0 years; mean, 6.0 years; range, 0–24 years) who had surgical revision between 1985 and 2011. From this cohort, we calculated the Kaplan-Meier survivorship for revision performed for any reason and compared it with the survivorship of 83,511 patients (mean age, 69.5 years; minimum followup 0 years; mean, 6.4 years; range, 0–27 years) with TKAs treated for primary osteoarthritis during the same period. Data were adjusted for age and sex in a comparative analysis.
Results
Kaplan-Meier survivorship of UKAs was 89.4% at 5 years, 80.6% at 10 years, and 69.6% at 15 years; the corresponding rates for TKAs were 96.3%, 93.3%, and 88.7%, respectively. UKAs had inferior long-term survivorship compared with cemented TKAs, even after adjusting for the age and sex of the patients (hazard ratio 2.2, p < 0.001).
Conclusions
A UKA offers tempting advantages compared with a TKA; however, the revision frequency for UKAs in widespread use, as measured in a large, national registry, was poorer than that of TKAs. When choosing between a UKA and a TKA, patients should be informed of advantages of both procedures, but they also should be advised about the generally higher revision risk after UKA.
Level of Evidence
Level III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.
The aim of this study was to evaluate the influence of antirheumatic drug treatment on knee function of stiff knee patients after total knee arthroplasty (TKA).
Twenty-seven patients (44 knees) of ...active RA (rheumatoid arthritis) or AS (ankylosing spondylitis) with stiff knees were included in this study. And they were divided into two groups according to continue antirheumatic drug treatment or not after TKA: the therapeutic group (16 patients, 27 knees) and the controlled group (11 patients, 17 knees). The outcomes were assessed by Knee Society Score (KSS), Visual Analogue Scale (VAS), range of motion (ROM) (at week 6, month 6, year 1, and year 2), "Forgotten Joint" Scale (FJS), with or without crutch, satisfaction, and revision (at year 2). The knee prosthetic loosening was evaluated by the followed X-ray at each following time.
The mean follow-up time was 51 months (34-69 months). The KSS was higher at week 6 after TKA in the therapeutic group (p < 0.05); however, the functional scores of KSS at month 6, year 1, and year 2 in the controlled group were more points improved. The therapeutic patients preferred the knee more at month 6, year 1, and year 2. The differences of KSS clinical scores (at month 6, year 1, and year 2), VAS, ROM, Crutch and FJS between the two groups were not statistically significant (p > 0.05).
For patients with stiff knees, the sequential antirheumatic drug treatment after TKA had no obvious effect on postoperative KSS, but can improve the satisfaction.
Therapeutic level II. See Instructions for Authors for a complete description of levels of evidence.
Purpose
To evaluate whether long-term (10-year minimum) patient outcomes and survival of fixed-bearing medial unicompartmental knee arthroplasty (UKA) in patients aged ≤ 60 years were favorable ...despite non-conventional age criteria.
Methods
The authors reviewed the records of 91 consecutive medial UKAs performed in patients aged ≤ 60 by a single surgeon. All patients received the same fixed-bearing M/G Unicompartmental Knee System. Patients records were updated, noting complications or revisions, and Oxford Knee Scores and overall satisfaction collected. If deceased, the general practitioner or next of kin provided data.
Results
Of the initial 91 knees, 10 were revised, 6 were deceased, and 1 was lost to follow-up. The final cohort of 74 knees was aged 54.3 ± 4.3 years (range 41.8–60.6) at index surgery. Using revision of any component as endpoint, the present series had a KM survival of 92.9% (CI 84.8–96.7%) at 10 years, and 87.8% (CI 78.4–93.2%) at 15 years, and a single non-fatal DVT was reported. At final follow-up of 15 ± 1.3 years (range 11–18), OKS (available for all 74 knees) was 38.4 ± 8.4 (range 18–48). Overall patients were pleased or very pleased with 72 of the knees (97%).
Conclusion
Fixed-bearing medial UKA yields favorable results in the treatment of single compartment osteoarthritis of the knee in patients ≤ 60 years. The present study demonstrates low complication rates, good-to-excellent long-term patient outcomes, and satisfactory implant survival for this age group considering the advantages of UKA.
Level of evidence
Level IV, retrospective cohort study.
More personalized implant designs for total knee arthroplasty might optimize the clinical outcome after surgery. One of these personalized implant designs is the Persona knee implant system (Zimmer ...Biomet, Warsaw, Indiana, USA). The primary objective of this study was to determine patient reported outcomes and implant survivorship of the Persona Knee system used in primary total knee arthroplasty, up to two years after surgery.
From November 2013 to July 2016 consecutive patients undergoing primary total knee arthroplasty were enrolled in a prospective observational cohort study at three centers. Preoperatively, at 6 weeks, 6 months, 1 and 2 years after surgery, patients completed the Knee Injury and Osteoarthritis Outcome Score (KOOS), the Oxford Knee Score (OKS), the Knee Society Score (KSS, 2011, modified version) and the EQ-5D. Adverse Events were captured, assessed for relationship to device, and recorded in the study database. Furthermore, physical functioning was assessed by the orthopedic surgeon. Repeated measures analyses were performed on PROM scores. Kaplan Meier was used to calculate survivorship of the Persona Knee Implant System.
A total of 146 total knee arthroplasties were performed. 61% (89/146) of the patients were female and mean age was 64.7 (± 6.9) years. Two years after surgery, one patient had a revision of the polyethylene insert because of a periprosthetic joint infection. Therefore, the Kaplan-Meier survival estimate at 2 years was 0.99 (0.95-1.00 95% CI). OKS increased from 22.1 (95% CI 20.9-23.3) to 41.8 (95% CI 40.6-43.1) two years after surgery. Furthermore, all other PROMs also increased from before surgery to 2 year postoperatively.
The Persona Knee implant is safe and effective and the clinical results up to two years after surgery are promising. PROMs results are very good; pain, function and quality of life all improved greatly after TKA. Further studies are needed to determine the long term clinical performance of the Persona prosthesis.
Clinicaltrials.gov ( NCT02337244 ). Registered June 1st, 2015. Retrospectively registered.
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