Vitamin E infused highly cross-linked cemented cups in total hip arthroplasty show good wear pattern and stabilize satisfactorily: a randomized, controlled RSA trial with 5-year follow-up.

Background and purpose - Vitamin E infused highly cross-linked polyethylene (VEPE) was introduced in order to enhance oxidative resistance in highly cross-linked polyethylene cups in total hip arthroplasty (THA). We have, with a follow-up of 5 years, evaluated wear characteristics of 2 identically designed cemented cups with the only difference being the material, VEPE or ultra-high molecular weight polyethylene (UHMWPE). Furthermore, we report cup migration and clinical outcome. Patients and methods - 48 patients with primary osteoarthritis were randomized to either UHMWPE or VEPE cups. Patients were followed with radiostereometric analysis (RSA) from the first postoperative day, at 3 months, 1, 2, and 5 years as well as with hip-specific outcome questionnaires. Results - At 3 months the mean proximal head penetration for UHMWPE was 0.07 mm (95% CI 0.03-0.11) and for VEPE 0.06 mm (-0.01 to 0.13). Thereafter, there was a continuous annual wear of 0.08 mm/year, up to 0.46 mm (0.36-0.57) at 5 years, for the UHMWPE cup. The VEPE cup showed low annual wear of 0.01 mm/year, up to 0.09 mm (0.02-0.16) at 5 years. In the first 3 months the UHMWPE cup migrated cranially 0.08 mm (0.03-0.13) whereas the VEPE cup migrated 0.17 mm (0.10-0.24), Thereafter, they showed similar migration patterns with stabilization between 2 and 5 years up to 0.21 mm (0.04-0.39) and 0.24 mm (0.13-0.36) respectively. The HOOS remained good up to 5 years, and no cup was revised. Interpretation - Compared with otherwise identical UHMWPE cups the cemented VEPE cup shows statistically significant reduction of wear up to 5 years and both cup types stabilize well with good clinical outcome.

Preserved periprosthetic bone stock at 5 years post-operatively with uncemented short hip stem in both collared and collarless version.

INTRODUCTION: Previous bone density studies have generally shown bone resorption around both cemented and uncemented total hip arthroplasty (THA) stems. This is presumed to be due to stress shielding. Short stems have been introduced partly to preserve bone in the proximal femur by a more physiological loading of the bone. The purpose of this study was to evaluate bone remodeling around a short, fully hydroxyapatite-coated titanium stem that comes in a collared and collarless version. PATIENTS AND METHODS: A prospective cohort of 50 patients included in a study evaluating the Furlong Evolution stem has been followed for 5 years. Examination was done with dual energy X-ray absorptiometry (DXA) postoperatively, at 1, 2 and 5 years. Clinical outcome was followed with radiography and both general and hip specific outcome measures. RESULTS: The two versions of the stem behaved similarly regarding bone remodeling. After an initial decrease up to 1 year, bone mineral density (BMD) increased in all Gruen zones up to 2 years and at 5 years bone stock was still preserved compared with postoperatively (net BMD + 1.2% (95% CI - 0.4 to 2.8)). Increase in BMD occurred mainly in the greater trochanter and distally around the stem with a decrease in the calcar area. Both versions showed excellent clinical outcome up to 5 years. CONCLUSION: This short stem seems to preserve proximal bone stock up to 5 years, exhibiting similar behaviour both with and without a collar. TRIAL REGISTRATION NUMBER AND DATE OF REGISTRATION: ClinicalTrials.gov, (identifier: NCT01894854). July 10, 2013.

Highly cross-linked polyethylene still outperforms conventional polyethylene in THA: 10-year RSA results.

Background and purpose - Cup wear in total hip arthroplasty (THA) can be affected by different manufacturing processes of the polyethylene (PE). We report the long-term wear pattern differences, as well as early creep behavior, between conventional PE and highly cross-linked PE (HXLPE) liners, as measured with radiostereometry (RSA) up to 10 years. We also compare migration and clinical outcome of 2 similar uncemented cups with different backside surface roughness.Patients and methods - We included 45 patients with primary osteoarthritis. 23 received a conventional liner and 22 an HXLPE liner in a similar uncemented cup, but with a slightly rougher surface. The patients were followed up with RSA and hip-specific outcome questionnaire (HOOS) at 3 months, 1, 2, 5, and 10 years.Results - During the first 3 months both liners showed expected deformation with mean proximal head penetration of 0.39 mm (conventional PE) and 0.21 mm (HXLPE). Between 3 months and 10 years there was a difference in annual wear with 0.12 mm/year for the conventional liner and 0.02 mm/year for the HXLPE liner. The cup with rougher surface had less initial migration but both types had stabilized after 3 months. The HOOS scores improved after surgery and remained high for both groups throughout the study period.Interpretation - Up to 10 years the HXLPE has consistent lower annual wear, possibly contributing to longer survival of the THA, compared with conventional PE. All patients reported good results regardless of liner type.

Fast-Track Programs in Total Hip and Knee Replacement at Swedish Hospitals-Influence on 2-Year Risk of Revision and Mortality.

PURPOSE: We aimed to study the influence of fast-track care programs in total hip and total knee replacements (THR and TKR) at Swedish hospitals on the risk of revision and mortality within 2 years after the operation. METHODS: Data were collected from the Swedish Hip and Knee Arthroplasty Registers (SHAR and SKAR), including 67,913 THR and 59,268 TKR operations from 2011 to 2015 on patients with osteoarthritis. Operations from 2011 to 2015 Revision and mortality in the fast-track group were compared with non-fast-track using Kaplan-Meier survival analysis and Cox regression analysis with adjustments. RESULTS: The hazard ratio (HR) for revision within 2 years after THR with fast-track was 1.19 (CI: 1.03-1.39), indicating increased risk, whereas no increased risk was found in TKR (HR 0.91; CI: 0.79-1.06). The risk of death within 2 years was estimated with a HR of 0.85 (CI: 0.74-0.97) for TKR and 0.96 (CI: 0.85-1.09) for THR in fast-track hospitals compared to non-fast-track. CONCLUSIONS: Fast-track programs at Swedish hospitals were associated with an increased risk of revision in THR but not in TKR, while we found the mortality to be lower (TKR) or similar (THR) as compared to non-fast track.

Migration pattern of a short uncemented stem with or without collar: a randomised RSA-study with 2 years follow-up.

BACKGROUND: There is an increasing interest in shorter, proximally loading, uncemented femoral stems. The aim of this study was to evaluate a new short stem type, its design based on a well-proven precursor, but with several new design features to facilitate easier insertion and possible preservation of proximal bone stock. It is available with or without a collar. METHODS: The study includes 50 patients with primary osteoarthritis, mean age 59 (range 36-75) years, randomised to receive either the collar-fitted or the collarless stem. The patients underwent repeated radiostereometry (RSA) examinations (0, 0.5, 3, 12, 24 months), conventional radiography and filled out both hip-specific (HOOS) and general health (EQ-5D) questionnaires. RESULTS: There was no statistically significant difference between the collared and collarless stems regarding migration and clinical outcome. Both stem types exhibit a similar pattern of initial subsidence (collared 0.63 mm vs. collarless 0.75 mm [p = 0.50]) and retroversion (collared 0.71° vs. collarless 0.97° [p = 0.36]) up to 3 months followed by stabilisation, in similarity with its precursors, suggesting good osseointegration. No stem has been revised or considered loose. CONCLUSIONS: The new design features, including shortening the stem, do not compromise migration pattern or osseointegration, regardless collar or not.

Unexpected varus deformity and concomitant metal ion release and MRI findings of modular-neck hip stems: descriptive RSA study in 75 hips with 8 years' follow-up.

Background and purpose - Modular-neck hip stems have been identified with corrosion-related problems from the neck-stem junction. We report an ongoing varus deformity of modular-neck hip stems with simultaneous metal ion release observed during a study comparing the migration of modular vs. standard hip stems.Patients and methods - We followed 50 patients with modular and 25 with standard neck stems using radiostereometry (RSA). At 5-year follow-up, we noted a compromised integrity of the modular stem with varus deformity in the neck-stem interface. Changes in head-tip distance as well as whole-blood ion concentration and MRI findings were analyzed. The modular stems were followed further up to 8 years.Results - The head-tip distance decreased continuously by 0.15 mm per year resulting in 1.2 (95% CI 1.0-1.4) mm at 8 years for modular stems, while for the standard stems at 5 years, the decrease was 0.09 (CI 0.0-0.2) mm or 0.02 mm/year. For the modular stems, the reduction in head-tip distance correlated to the increase in whole-blood cobalt concentration at 8 years but not to the MRI grading of tissue reactions. At 5 years, cobalt levels were 4.9 µg/L for modular stems and at 8 years 4.8 µg/L, whereas for standard stems this was 1.0 µg/L. After 8 years, 9 of 72 stems had been revised for different reasons, but only 1 with obvious adverse local tissue reaction (ALTR).Interpretation - We present a surprisingly large progressive deformation at the modular neck-stem junction, but so far without a definite clinical problem. Even the femoral head seems to show slight compression onto the taper over time. A high rate of revisions for the modular type of this stem has raised general concerns, and it has been recalled from the market.

Pre- and postoperative offset and femoral neck version measurements and validation using 3D computed tomography in total hip arthroplasty.

BACKGROUND: Restoration of a correct biomechanical situation after total hip arthroplasty is important. PURPOSE: To evaluate proximal femoral symmetry of acetabular and femoral offset and femoral neck anteversion pre- and postoperatively in hip arthroplasty by semi-automated 3D-CT and to validate the software measurements by inter- and intraobserver agreement calculations. MATERIAL AND METHODS: In low-dose CT on 71 patients before and after unilateral total hip arthroplasty, two observers used a digital 3D templating software to measure acetabular offset, true and functional femoral offset, and femoral neck anteversion. Observer agreements were calculated using intraclass correlation. Hip measurements were compared in each patient and between pre- and postoperative measurements. RESULTS: Preoperatively, acetabular offset (2.4 mm), true (2.2 mm), and functional global offset (2.7 mm) were significantly larger on the osteoarthritic side without side-to-side differences for true and functional femoral offset or femoral neck anteversion. Postoperatively, acetabular offset was significantly smaller on the operated side (2.1 mm) with a concomitantly increased true (2.5 mm) and functional femoral offset (1.5 mm), resulting in symmetric true and functional global offsets. There were no differences in postoperative femoral neck anteversion. Inter- and intraobserver agreements were near-perfect, ranging between 0.92 and 0.98 with narrow confidence intervals (0.77-0.98 to 0.94-0.99). CONCLUSION: Acetabular and concomitantly global offset are generally increased in hip osteoarthritis. Postoperative acetabular offset was reduced, and femoral offset increased to maintain global offset. 3D measurements were reproducible with near-perfect observer agreements. 3D data sets should be used for pre- and postoperative measurements in hip arthroplasty.

Polyethylene Wear With Ceramic and Metal Femoral Heads at 5 Years: A Randomized Controlled Trial With Radiostereometric Analysis.

BACKGROUND: A common bearing combination in total hip arthroplasty today is a metal femoral head articulating with polyethylene in the cup. Ceramic heads are thought to be more resistant to third-body damage, and have better wettability and decreased surface roughness, which taken together have been suggested to result in less polyethylene wear. The purpose of this study is to compare the initial creep deformation and follow wear pattern, using radiostereometric analysis, of ceramic and metal femoral heads that articulate with a modern highly cross-linked polyethylene cup liner. METHODS: Fifty patients with primary osteoarthritis and scheduled for an uncemented total hip arthroplasty were randomized 1:1 to either a ceramic (BIOLOX delta) or a metal (CoCr) femoral head. The patients were followed up for 5 years with repeated radiostereometric analysis examinations (postoperatively, then at 14 days, 3, 12, 24, and 60 months), as well as a hip-specific outcome questionnaire. RESULTS: During the first 3 months both groups showed expected creep within the liner of 0.12 mm (standard deviation 0.03) for the ceramic and 0.08 mm (standard deviation 0.02) for the metal heads. Between 3 months and 5 years there was very little wear of the liner in either group, corresponding to 0.003 mm/y for ceramic and 0.007 mm/y for metal heads. There was no difference in cup migration or clinical outcome between the groups and no cups were revised. CONCLUSION: With the introduction of modern highly cross-linked polyethylene, the ceramic head demonstrates no superiority when it comes to either early deformation or polyethylene wear compared with the metal head.

Effect of symmetrical restoration for the migration of uncemented total hip arthroplasty: a randomized RSA study with 75 patients and 5-year follow-up.

BACKGROUND: Inferior placement of a femoral stem is predictive for early loosening and failure, but does restoration of the original hip anatomy benefit the function and survival of a total hip replacement? METHODS: Seventy-five patients with primary unilateral hip osteoarthritis operated with an uncemented anatomical stem were randomized for either standard or modular stems. We used 50 ABG II stems with modular necks and 25 standard stems (control group). We measured the symmetry in hip anatomy between healthy and operated side. The anatomical restoration variables were anteversion, global offset, and femoral offset/acetabular offset (FO/AO) quota. We performed measurements using a CT-based 3D templating and measuring software. Migratory behavior of the stems was then measured postoperatively with repeated radiostereometry (RSA) examinations over 5 years. RESULTS: Both stem types showed an early (within 3 months) good stabilization after an initial slight rotation into retroversion and subsidence. There were no significant differences in RSA migration between modular and standard stems. Postoperative anteversion and FO/AO quota had no impact on stem migration. The standard stem tended to result in insufficient global offset (GO), whereas the modular stem did not. CONCLUSIONS: The modular stem gave good symmetrical anatomical restoration and, like the standard version, a benign migratory behavior. Anteversion, GO, and FO/AO quota had no significant impact on stem migration. It therefore seems to be of no importance whether we choose a modular or a standard stem with regard to postoperative stem migration for this stem type. We overestimated the effect anatomical parameters have on stem movement; hence, we believe the study to be underpowered. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01512550. Registered 19 January 2012-retrospectively registered.

Increases in the rates of primary and revision knee replacement are reducing: a 15-year registry study across 3 continents.

Background and purpose - Rates of knee replacement (KR) are increasing worldwide. Based on population and practice changes, there are forecasts of a further exponential increase in primary knee replacement through to 2030, and a corresponding increase in revision knee replacement. We used registry data to document changes in KR over the past 15 years, comparing practice changes across Sweden, Australia, and the United States. This may improve accuracy of future predictions.Patients and methods - Aggregated data from the Swedish Knee Arthroplasty Register (SKAR), the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR), and the Kaiser Permanente Joint Replacement Registry (KPJRR) were used to compare surgical volume of primary and revision KR from 2003 to 2017. Incidence was calculated using population census statistics from Statistics Sweden and the Australian Bureau of Statistics, as well as the yearly active membership numbers from Kaiser Permanente. Further analysis of KR by age < 65 and ≥ 65 years was carried out.Results - All registries recorded an increase in primary and revision KR, with a greater increase seen in the KPJRR. The rate of increase slowed during the study period. In Sweden and Australia, there was a smaller increase in revision surgery compared with primary procedures. There was consistency in the mean age at surgery, with a steady small decrease in the proportion of women having primary KR. The incidence of KR in the younger age group remained low in all 3 registries, but the proportional increases were greater than those seen in the ≥ 65 years of age group.Interpretation - There has been a generalized deceleration in the rate of increase of primary and revision KR. While there are regional differences in KR incidence, and rates of change, the rate of increase does not seem to be as great as previously predicted.

Influence of fast-track programs on patient-reported outcomes in total hip and knee replacement (THR/TKR) at Swedish hospitals 2011-2015: an observational study including 51,169 THR and 8,393 TKR operations.

Background and purpose - Fast-track care programs have been broadly introduced at Swedish hospitals in elective total hip and knee replacement (THR/TKR). We studied the influence of fast-track programs on patient-reported outcomes (PROs) 1 year after surgery, by exploring outcome measures registered in the Swedish arthroplasty registers.Patients and methods - Data were obtained from the Swedish Knee and Hip Arthroplasty Registers and included TKR and THR operations 2011-2015 on patients with osteoarthritis. Based on questionnaires concerning the clinical pathway and care programs at Swedish hospitals, the patients were divided in 2 groups depending on whether they had been operated in a fast-track program or not. PROs of the fast-track group were compared with not fast-track using regression analysis. EQ-5D, EQ VAS, Pain VAS, and Satisfaction VAS were analyzed for both THR and TKR operations. The PROMs for TKR also included KOOS.Results - The differences of EQ-5D, EQ VAS, Pain VAS, and Satisfaction VAS 1 year after surgery were small but all in favor of fast-track for both THR and TKR, also in subscales of KOOS for TKR except KOOS QoL. However, the effect sizes as measured by Cohens' d formula were < 0.2 for all PROs, in both THR and TKR.Interpretation - Our results indicate that the fast-track programs may be at least as good as conventional care from the perspective of PROs 1-year postoperatively.

Higher Risk of Loosening for a Four-Pegged TKA Tibial Baseplate Than for a Stemmed One: A Register-based Study.

BACKGROUND: Modern modular implants allow surgeons to mix different combinations of components within the same brand. From 1999 to 2012, the NexGen®-CR Option femoral component, together with a NexGen® Option Stemmed tibial plate (stemmed baseplate), which uses a short central stem, was the most-frequently used NexGen® combination in the Swedish Knee Arthroplasty Register. However, from 1999 to 2012, the same femoral component was also used along with the NexGen® Precoat four-pegged tibial baseplate (pegged baseplate). Considering the difference in the fixation concepts for these two tibial baseplates, we wanted to study whether their revision rates differed. QUESTIONS/PURPOSES: To investigate the difference in (1) all-cause revision and (2) the risk of revision for aseptic loosening between the NexGen® pegged and stemmed baseplates when used with the NG-CR Option femoral component and the same two types of inserts. METHODS: The Swedish Knee Arthroplasty Register provided data. The register, which was started in 1975, has since 1999 registered part numbers for individual implant components, allowing it to assess the combinations of components used in each patient. It has been shown to have high completeness (97%) and validity [12, 15]. The inclusion period was 1999 to 2012; during that time, 137,143 primary knee arthroplasties were registered, of which 125,094 were TKAs. Only TKAs performed for osteoarthritis and without patellar resurfacing were included, since not resurfacing the patella is the standard procedure in Sweden. This left 15,287 knees with the stemmed baseplate and 2479 with the pegged baseplate, or 12% and 2% of the total number of TKAs, respectively. Two general hospitals used the pegged baseplate exclusively during that period. Thus, specific patients were not selected for having the pegged plate. The mean age, mortality, and length of followup were similar for the two groups.We used the Kaplan-Meier statistics to calculate the cumulative revision rate (CRR) and Cox regression to compare risk ratios after adjusting for age and sex. The end point was a knee revision for respective all causes or aseptic loosening. The study ended on December 31, 2016. Due to the free healthcare system in Sweden it is highly unusual for patients to seek elective revision abroad, and by use of the extensive Swedish census register, we estimate the level of followup approximately 97%. RESULTS: Knees with the pegged baseplate had a higher risk for all-cause revision than did those with the stemmed baseplate (5.8% [95% confidence interval {CI}, 4-8.3] and 3% [95% CI, 2.6-3.5] at 15 years; p = 0.003). After controlling for age and sex, the aseptic loosening risk in the pegged baseplate group was still higher than that in the stemmed group (relative risk, 5.40; 95% CI, 3.64-8.02; p < 0.001). CONCLUSIONS: In this Swedish registry study, we observed a higher loosening risk with the pegged baseplate than the stemmed one, even after controlling for age and sex. Because this was only a comparison of implants from one vendor, and because there may have been other between-group differences for which we could not fully control, this concerning finding should be explored using data from other registries. LEVEL OF EVIDENCE: Level III, therapeutic study.

Patient-reported 1-year outcome not affected by body mass index in 3,327 total knee arthroplasty patients.

Background and purpose - Patient-reported outcome (PRO) in total knee arthroplasty (TKA) patients with high body mass index (BMI) is controversial. We compared pain, function, quality of life, general health, and satisfaction among different BMI categories preoperatively and 1 year after primary TKA. Patients and methods - 4,318 patients were operated with a TKA for knee osteoarthritis in the Region of Skane in 2013-2015. In all, 3,327 patients (77%) had complete PRO data and information on BMI and were included. Preoperatively the patients filled in the Knee injury and Osteoarthritis Outcome Score (KOOS) and EQ-VAS (general health). 1 year postoperatively the same questionnaires were filled in together with a question asking whether they were satisfied with the surgery. Information on age, sex, BMI, and ASA grade were obtained from the Swedish Knee Arthroplasty Register. Each patient was classified as Outcome Measures in Rheumatology- Osteoarthritis Research Society International (OMERACT-OARSI) responder or not based on a combination of absolute and relative changes in scores. Welch's t-test and a chi-square test were used in the statistical analysis. Results - Both preoperatively and 1 year postoperatively the obese patients reported somewhat worse scores than the normal weight and overweight. The differences were small with 1 exception, the KOOS sport- and recreation function postoperatively, where normal-weight and overweight patients reported fewer problems than obese patients with a BMI over 35 (40 and 39 points vs. 31 points, p < 0.001). Similar proportions of patients were satisfied and categorized as OMERACT-OARSI responders in the different BMI categories. Interpretation - The degree of improvement in PROs 1 year after TKA surgery does not seem to be affected by BMI.

Locally administered bisphosphonate in hip stem revisions using the bone impaction grafting technique: a randomised, placebo-controlled study with DXA and five-year RSA follow-up.

BACKGROUND:: Bisphosphonates have previously been shown to increase the density of impacted graft bone. In the present study we hypothesise that bisphosphonates also reduce early stem subsidence. We examined the effect of locally applied bisphosphonate to allografts on prosthetic micromotion and bone density in femoral stem revision with impaction grafting. METHODS:: 37 patients were randomised to either clodronate or saline as local adjunct to the morsellised allograft bone. 24 patients were finally analysed per protocol and evaluated by dual-energy x-ray absorptiometry (DXA) during the first year and with radiostereometric analysis (RSA) for 5 years. RESULTS:: There were no significant differences neither in bone density, nor in migratory behaviour between the groups. The femoral stems had subsided 3.6 mm in both groups (p = 0.99) at 5 years and there was no difference as measured over time with mixed models analysis. The clinical outcome was good in both groups. CONCLUSION:: Clodronate as a local addendum to allograft bone in hip revision did not increase bone density or reduce micromotion of the implant.

No increase in readmissions or adverse events after implementation of fast-track program in total hip and knee replacement at 8 Swedish hospitals: An observational before-and-after study of 14,148 total joint replacements 2011-2015.

Background and purpose - Fast-track care programs in elective total hip and knee replacement (THR/TKR) have been introduced in several countries during the last decade resulting in a significant reduction of hospital stay without any rise in readmissions or early adverse events (AE). We evaluated the risk of readmissions and AE within 30 and 90 days after surgery when a fast-track program was introduced in routine care of joint replacement at 8 Swedish hospitals. Patients and methods - Fast-track care programs were introduced at 8 public hospitals in Västra Götaland region from 2012 to 2014. We obtained data from the Swedish Hip and Knee Arthroplasty Registers for patients operated with THR and TKR in 2011-2015. All readmissions and new contacts with the health care system within 3 months with a possible connection to the surgical intervention were requested from the regional patient register. We compared patients operated before and after the introduction of the fast-track program. Results - Implementation of the fast-track program resulted in a decrease in median hospital length of stay (LOS) from 5 to 3 days in both THR and TKR. The total readmission rate <90 days for THR was 7.2% with fast-track compared with 6.7% in the previous program, and for TKR 8.4% in both groups. Almost half of the readmissions occurred without any AE identified. There was no statistically significant difference concerning readmissions or AE when comparing the programs. Interpretation - Implementation of a fast-track care program in routine care of elective hip and knee replacement is effective in reducing hospital stay without increasing the risk of readmissions or adverse events within 90 days after surgery.

Decreased migration with locally administered bisphosphonate in cemented cup revisions using impaction bone grafting technique.

Background and purpose - Impaction bone grafting (IBG) in revision hip surgery is an established method in restoring bone stock deficiencies. We hypothesized that local treatment of the morsellized allograft with a bisphosphonate in cemented revision would, in addition to increased bone density, also reduce the early migration of the cup as measured by radiostereometry (RSA). Patients and methods - 20 patients with aseptic cup loosening underwent revision using the IBG technique. The patients were randomized to either clodronate (10 patients) or saline (10 patients, control group) as local adjunct to the morsellized bone. The outcome was evaluated by dual-energy X-ray absorptiometry (DXA) during the first year regarding periacetabular bone density and with radiostereometric analysis (RSA) for the first 2 years regarding cup migration. Results - 2 patients were lost to follow-up: 9 patients remained in the clodronate and 9 in the control group. Less proximal migration was found in the clodronate group compared with the controls, measured both over time (mixed-models analysis, p = 0.02) as well as at the specified time points up to 2 years (0.22 mm and 0.59 mm respectively, p = 0.02). Both groups seemed to have stabilized at 1 year. We found similar bone mineral density measured by DXA, and similar RSA migration in the other directions. No cups were re-revised. Interpretation - Local treatment of the allograft bone with clodronate reduced early proximal migration of the revised cup but without any measurable difference in periacetabular bone density.

Higher risk of revision for infection using systemic clindamycin prophylaxis than with cloxacillin.

Background and purpose - Clindamycin has not been compared with other antibiotics for prophylaxis in arthroplasty. Since 2009, the Swedish Knee Arthroplasty Register (SKAR) has been collecting information on the prophylactic antibiotic regime used at every individual operation. In Sweden, when there is allergy to penicillin, clindamycin has been the recommended alternative. We examined whether there were differences in the rate of revision due to infection depending on which antibiotic was used as systemic prophylaxis. Patients and methods - Patients who had a total knee arthroplasty (TKA) performed due to osteoarthritis (OA) during the years 2009-2015 were included in the study. Information on which antibiotic was used was available for 80,018 operations (55,530 patients). Survival statistics were used to calculate the rate of revision due to infection until the end of 2015, comparing the group of patients who received cloxacillin with those who received clindamycin as systemic prophylaxis. Results - Cloxacillin was used in 90% of the cases, clindamycin in 7%, and cephalosporins in 2%. The risk of being revised due to infection was higher when clindamycin was used than when cloxacillin was used (RR =1.5, 95% CI: 1.2-2.0; p = 0.001). There was no significant difference in the revision rate for other causes (p = 0.2). Interpretation - We advise that patients reporting allergic reaction to penicillin should have their allergic history explored. In the absence of a clear history of type-I allergic reaction (e.g. urticaria, anaphylaxis, or bronchospasm), we suggest the use of a third-generation cephalosporin instead of clindamycin as perioperative prophylaxis when undergoing a TKR. No recommendation can be given regarding patients with type-1 allergy.

Comparable Results With Porous Metal Augments in Combination With Either Cemented or Uncemented Cups in Revision Hip Arthroplasty: An Analysis of One Hundred Forty-Seven Revisions at a Mean of Five Years.

BACKGROUND: Porous metal augments have been used successfully for management of large acetabular defects during revision hip arthroplasty. The purpose of this study was to retrospectively review and compare the clinical and radiographic outcomes of porous metal augments in cemented and uncemented acetabular revisions, all performed at the same institution. METHODS: Using our institutional clinical databases, the clinical and radiological outcomes of 104 cemented and 43 uncemented acetabular revisions with metal augments, performed between 2006 and 2015, were studied and compared. Acetabular augments were used when preoperative and intraoperative findings indicated the presence of large acetabular defects that can hinder the stability of the revision implants. RESULTS: At a mean follow-up of 60.1 months (range 12.7-112.1), a total of 5 cups (3.4%), being 3 cemented (2.8%) and 2 uncemented (4.6%), had shown signs of aseptic loosening with cup and augment migration and 4 of these have been re-revised (2.7%). At final follow-up, the European Quality of Life-5 Dimensions for generic health, and the Hip disability and Osteoarthritis Outcome Score (HOOS) parameters had improved substantially without any significant difference between fixation techniques. CONCLUSION: Porous metal augments show comparable excellent radiographic and clinical mid-term outcomes when combined with cemented or uncemented cups in revision hip arthroplasty.

Preoperative Anxiety and Depression Correlate With Dissatisfaction After Total Knee Arthroplasty: A Prospective Longitudinal Cohort Study of 186 Patients, With 4-Year Follow-Up.

BACKGROUND: After more than 4 decades experience of total knee arthroplasty (TKA), there is still a group of patients who are not satisfied with the outcome. In spite of the improvement of many aspects around the procedure, for unexplainable reasons, patient dissatisfaction is still approximately the same. We conducted this study to analyze correlations between preoperative psychological aspects and dissatisfaction after TKA. METHODS: A total of 186 patients were operated with a primary TKA. Patients filled out the Hospital Anxiety and Depression Scale, Visual Analog Pain Scale (0-100), and Knee injury and Osteoarthritis Outcome Score preoperatively and 4 years postoperatively. Four years postoperatively, the patients also scored their satisfaction degree with the outcome of the surgery. RESULTS: Of 186 patients, 27 (15%) reported that they were dissatisfied or uncertain with the result of their TKA 4 years postoperatively. Sixteen of those 27 patients had reported anxiety/depression preoperatively compared with 11 of 159 (7%) in the satisfied or very satisfied groups. Patients with preoperative anxiety or depression had more than 6 times higher risk to be dissatisfied compared with patients with no anxiety or depression (P < .001). Patients with deep prosthetic infection had 3 times higher risk to be dissatisfied with the operation outcome (P = .03). Dissatisfied patients had 1-day longer hospital stay compared with the satisfied group (P < .001). CONCLUSION: Preoperative anxiety and/or depression is an import predictor for dissatisfaction after TKA. Psychological assessment and treatment preoperatively might improve degree of satisfaction.

Similar patient-reported outcomes and performance after total knee arthroplasty with or without patellar resurfacing.

Background and purpose - Knee pain after total knee arthroplasty (TKA) is not uncommon. Patellar retention in TKA is one cause of postoperative knee pain, and may lead to secondary addition of a patellar component. Patellar resurfacing in TKA is controversial. Its use ranges from 2% to 90% worldwide. In this randomized study, we compared the outcome after patellar resurfacing and after no resurfacing. Patients and methods - We performed a prospective, randomized study of 74 patients with primary osteoarthritis who underwent a Triathlon CR TKA. The patients were randomized to either patellar resurfacing or no resurfacing. They filled out the VAS pain score and KOOS questionnaires preoperatively, and VAS pain, KOOS, and patient satisfaction 3, 12, and 72 months postoperatively. Physical performance tests were performed preoperatively and 3 months postoperatively. Results - We found similar scores for VAS pain, patient satisfaction, and KOOS 5 subscales at 3, 12, and 72 months postoperatively in the 2 groups. Physical performance tests 3 months postoperatively were also similar in the 2 groups. No secondary resurfacing was performed in the group with no resurfacing during the first 72 months Interpretation - Patellar resurfacing in primary Triathlon CR TKA is of no advantage regarding pain, physical performance, KOOS 5 subscales, or patient satisfaction compared to no resurfacing. None of the patients were reoperated with secondary addition of a patellar component within 6 years. According to these results, routine patellar resurfacing in primary Triathlon TKA appears to be unnecessary.