S100A8/A9 drives monocytes towards M2-like macrophage differentiation and associates with M2-like macrophages in osteoarthritic synovium.

OBJECTIVES: Macrophages are key orchestrators of the osteoarthritis (OA)-associated inflammatory response. Macrophage phenotype is dependent on environmental cues like the inflammatory factor S100A8/A9. Here, we investigated how S100A9 exposure during monocyte-to-macrophage differentiation affects macrophage phenotype and function. METHODS: OA synovium cellular composition was determined using flow cytometry and multiplex immunohistochemistry. Healthy donor monocytes were differentiated towards M1- and M2-like macrophages in presence of S100A9. Macrophage markers were measured using flow cytometry and phagocytic activity was determined using pHrodo Red Zymosan A BioParticles. Gene expression was determined using qPCR. Protein secretion was measured using Luminex and ELISA. RESULTS: Macrophages were the dominant leucocyte subpopulation in OA synovium. They mainly presented with a M2-like phenotype, although the majority also expressed M1-like macrophage markers. Long-term exposure to S100A9 during monocyte-to-macrophage differentiation increased M2-like macrophage markers CD163 and CD206 in M1-like and M2-like differentiated cells. In addition, M1-like macrophage markers were increased in M1-like, but decreased in M2-like differentiated macrophages. In agreement with this mixed phenotype, S100A9 stimulation modestly increased expression and secretion of pro-inflammatory markers and catabolic enzymes, but also increased expression and secretion of anti-inflammatory/anabolic markers. In accordance with the upregulation of M2-like macrophage markers, S100A9 increased phagocytic activity. Finally, we indeed observed a strong association between S100A8 and S100A9 expression and the M2-like/M1-like macrophage ratio in end-stage OA synovium. CONCLUSION: Chronic S100A8/A9 exposure during monocyte-to-macrophage differentiation favours differentiation towards a M2-like macrophage phenotype. The properties of these cells could help explain the catabolic/anabolic dualism in established OA joints with low-grade inflammation.

Dutch multidisciplinary guideline on anterior knee pain: Patellofemoral pain and patellar tendinopathy.

PURPOSE: The purpose of this study was to develop a multidisciplinary guideline for patellofemoral pain (PFP) and patellar tendinopathy (PT) to facilitate clinical decision-making in primary and secondary care. METHODS: A multidisciplinary expert panel identified questions in clinical decision-making. Based on a systematic literature search, the strength of the scientific evidence was determined according to the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) method and the weight assigned to the considerations by the expert panel together determined the strength of the recommendations. RESULTS: After confirming PFP or PT as a clinical diagnosis, patients should start with exercise therapy. Additional conservative treatments are indicated only when exercise therapy does not result in clinically relevant changes after six (PFP) or 12 (PT) weeks. Pain medications should be reserved for cases of severe pain. The additional value of imaging assessments for PT is limited. Open surgery is reserved for very specific cases of nonresponders to exercise therapy and those requiring additional conservative treatments. Although the certainty of evidence regarding exercise therapy for PFP and PT had to be downgraded ('very low GRADE' and 'low GRADE'), the expert panel advocates its use as the primary treatment strategy. The panel further formulated weaker recommendations regarding additional conservative treatments, pain medications, imaging assessments and open surgery ('very low GRADE' to 'low GRADE' assessment or absence of scientific evidence). CONCLUSION: This guideline recommends starting with exercise therapy for PFP and PT. The recommendations facilitate clinical decision-making, and thereby optimizing treatment and preventing unnecessary burdens, risks and costs to patients and society. LEVEL OF EVIDENCE: Level V, clinical practice guideline.

Smoking is associated with higher short-term risk of revision and mortality following primary hip or knee arthroplasty: a cohort study of 272,640 patients from the Dutch Arthroplasty Registry.

BACKGROUND AND PURPOSE: Patients actively smoking at the time of primary hip or knee arthroplasty are at increased risk of direct perioperative complications. We investigated the association between smoking status and risk of revision and mortality within 2 years following hip or knee arthroplasty. METHODS: We used prospectively collected data from the Dutch Arthroplasty Register. All primary total hip arthroplasties (THAs), total knee arthroplasties (TKAs), and unicondylar knee arthroplasties (UKAs) with > 2 years' follow-up were included (THA: n = 140,336; TKA: n = 117,497; UKA: n = 14,807). We performed multivariable Cox regression analyses to calculate hazard risks for differences between smokers and non-smokers, while adjusting for confounders (aHR). RESULTS: The smoking group had higher risk of revision (THA: aHR 1.3, 95% confidence interval [CI] 1.1-1.4 and TKA: aHR 1.4, CI 1.3-1.6) and risk of mortality (THA: aHR 1.4, CI 1.3-1.6 and TKA: aHR 1.4, CI 1.2-1.6). Following UKA, smokers had a higher risk of mortality (aHR 1.7, CI 1.0-2.8), but no differences in risk of revision were observed. The smoking group had a higher risk of revision for infection following TKA (aHR 1.3, CI 1.0-1.6), but not following THA (aHR 1.0, CI 0.8-1.2). CONCLUSION: This study showed that the risk of revision and mortality is higher for smokers than for non-smokers in the first 2 years following THA and TKA. Smoking could contribute to complications following primary hip or knee arthroplasty.

Dutch Guideline on Knee Arthroscopy Part 2: non-meniscus intra-articular knee injury: a multidisciplinary review by the Dutch Orthopaedic Association.

Background and purpose - A guideline committee of medical specialists and a physiotherapist was formed on the initiative of the Dutch Orthopedic Association (NOV) to update the Guideline Arthroscopy of the Knee: Indications and Treatment 2010. This next Guideline was developed between June 2017 and December 2019. In part 1 we focused on the meniscus; this part 2 addresses all other aspects of knee arthroscopy.Methods - The guideline was developed in accordance with the criteria of the AGREE instrument (AGREE II: Appraisal of Guidelines for Research and Evaluation II) with support of a professional methodologist from the Dutch Knowledge Institute of Medical Specialists. The scientific literature was searched and systematically analyzed. Conclusions and recommendations were formulated according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) method. Recommendations were developed considering the balance of benefits and harms, the type and quality of evidence, the values and preferences of the people involved, and the costs.

Dutch Guideline on Knee Arthroscopy Part 1, the meniscus: a multidisciplinary review by the Dutch Orthopaedic Association.

Background and purpose - A guideline committee of medical specialists and a physiotherapist was formed on the initiative of the Dutch Orthopedic Association (NOV) to update the guideline Arthroscopy of the Knee: Indications and Treatment 2010. This next guideline was developed between June 2017 and December 2019. In this Part 1 we focus on the meniscus, in Part 2 on all other aspects of knee arthroscopy.Methods - The guideline was developed in accordance with the criteria of the AGREE instrument (AGREE II: Appraisal of Guidelines for Research and Evaluation II) with support of a professional methodologist from the Dutch Knowledge Institute of Medical Specialists. The scientific literature was searched and systematically analyzed. Conclusions and recommendations were formulated according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) method. Recommendations were developed considering the balance of benefits and harms, the type and quality of evidence, the values and preferences of the people involved, and the costs.

Patellar height measurements: Insall-Salvati ratio is most reliable method.

PURPOSE: Patella alta is a risk factor for patellofemoral pain and instability. Several measurement methods and imaging modalities are in use to measure patellar height. The first aim of this study was to determine the intra- and interrater reliability of different patellar height measurement methods on conventional radiography (CR), CT and MRI. The second aim was to examine the applicability of patellar height measurement methods originally designed for CR on CT and MRI. METHODS: Forty-eight patients who were treated for patellar instability were included. All patients had undergone a pre-operative conventional radiograph, CT scan and MRI. Five methods for measuring patellar height were performed on radiographs, CT and MRI by four observers. For each measurement, the intra- and interrater reliability was determined by calculating the intra-class correlation coefficient (ICC). A Bland-Altman analysis was performed for measurements with an ICC ≥ 0.70. RESULTS: The Insall-Salvati (IS) ratio was the only measurement that showed good intra- and inter-observer reliability on CR, CT and MRI. The intra- and inter-observer reliability of the patellotrochlear index (PTI) for MRI was good to excellent for all observers. The IS ratio showed a moderate to good reliability for comparison of all three imaging modalities with the best agreement between radiography and MRI. The other patellar height measurements showed only poor to moderate inter-method agreement. CONCLUSION: In this study, the Insall-Salvati ratio shows better intra- and inter-observer reliability than the Blackburne-Peel ratio, the Caton-Deschamps ratio and the modified Insall-Salvati ratio on all imaging modalities. Radiography and CT seem to have better reliability than MRI. The patellotrochlear index, however, shows good inter- and intra-observer reliability on MRI. Only for the IS method was there acceptable agreement between CR and MRI. This means that the established Insall-Salvati normal values could be used for MRI as well. This study shows that the most reliable method to measure patella height is the Insall-Salvati ratio measured on conventional radiographs or the patellotrochlear index on MRI. LEVEL OF EVIDENCE: Level II diagnostic.

A detaching, V-shaped tibial tubercle osteotomy is a safe procedure with a low complication rate.

INTRODUCTION: In patients with recurrent patellar dislocations, a tibial tubercle osteotomy (TTO) can be indicated to correct patella alta or an increased trochlear groove-tibial tubercle distance. Several surgical techniques are described. Previous studies emphasize that detaching osteotomies results in devascularisation, which can lead to non-union and tibial shaft fractures. The aim of this study was to report the complication rates directly related to the surgical technique of a V-shaped TTO, where the tubercle is completely released from its periosteum using a step-cut osteotomy. METHODS: The retrospective case series comprised a large cohort of 263 knees with patella alta in 203 patients who underwent a V-shaped TTO, with or without additional realignment procedures, between March 2004 and October 2017. Data were obtained from available patient files. Complications were defined as minor or major. RESULTS: Thirteen major complications were registered (4.9%) including two tibial fractures (0.75%) and one non-union (0.37%). Five complications (1.9%) were defined as minor. Removal of the screws because of irritation or pain was seen in 22 cases (8.2%). CONCLUSION: A V-shaped TTO is a safe procedure. The presumed higher risk for tibial fractures or pseudo-arthrosis could not be confirmed.

Dutch translation and validation of the Norwich Patellar Instability score and Banff Patella Instability Instrument in patients after surgery for patellar instability.

Recently, two new English specific patient reported outcome measures (PROMs) to evaluate treatment of patients with patellofemoral complaints have been developed : the Banff Patella Instability Instrument (BPII) and the Norwich Patellar Instability (NPI) score. This study was designed to translate and validate the BPII and NPI in Dutch patients after surgical treatment for patellar instability. Forward and backward translation of the outcome measures was performed. Patients who had been surgically treated for patellar instability filled out the NPI and BPII together with the Kujala Knee Score, numeric rating scales, Knee disability and Osteoarthritis Outcome Score (KOOS) and SF- 36. We assessed internal consistency and construct validity. We evaluated the presence of ceiling and floor effects. Ninety-seven patients completed the online questionnaires. The internal consistency of the NPI and BPII score was excellent for both outcome measures. The BPII and NPI had good correlations with other PROMs. For the BPII we found no floor nor ceiling effect. For the NPI we found a floor effect but no ceiling effect. Our results indicate that the Dutch version of the BPII and the NPI can be used for patients with patellar instability. Both PROMs have specific (dis) advantages.

Preliminary effects of a regional approached multidisciplinary educational program on healthcare utilization in patients with hip or knee osteoarthritis: an observational study.

BACKGROUND: Providing relevant information on disease and self-management helps patients to seek timely contact with care providers and become actively involved in their own care process. Therefore, health professionals from primary care, multiple hospitals and health organisations jointly decided to develop an educational program on osteoarthritis (OA). The objective of the present study was to determine preliminary effects of this OA educational program on healthcare utilization and clinical outcomes. METHODS: We developed an educational group-based program consisting of 2 meetings of 1.5 h, provided by a physiotherapist, a general practitioner (GP) and orthopaedic surgeon or specialized nurse. The program included education on OA, (expectations regarding) treatment options and self-management. Patients were recruited through searching the GPs' electronic patients records and advertisements in local newspapers. At baseline and at 3 months follow-up participating OA patients completed questionnaires. Paired-sample t-tests, McNemar's test and Wilcoxon Signed-Rank test were used to estimate the preliminary effects of the program. RESULTS: A total of 146 participants in 3 districts attended the sessions, of whom 143 agreed to participate in this study; mean age 69.1 years (SD10.2).107 (75%) participants completed both baseline and follow up assessments. The proportion of participants who had visited their GP in the 3 months after the program was lower than 3 months previous to the program (40% versus 25%, p-value 0.01). Also, we observed a decrease in proportion of patients who visited the physio- and exercise therapist, (36.1% versus 25.0%, p-value 0.02). Both illness perceptions and knowledge on OA and treatment options changed positively (Δ-1.8, 95%CI:0.4-3.4, and Δ2.4, 95%CI:-3.0 - -1.6 respectively). No changes in BMI, pain, functioning and self-efficacy were found. However, a trend towards an increase in physical activity was observed. CONCLUSIONS: Our results show that a multidisciplinary educational program may result in a decrease in healthcare utilization and has a positive effect on illness perceptions and knowledge on OA due to clear and consistent information on OA and it treatment options. TRIAL REGISTRATION: Netherlands Trial Register ( NTR5472 ). Registered 22 September 2015.

Incidence and Risk Factors of Postoperative Urinary Retention and Bladder Catheterization in Patients Undergoing Fast-Track Total Joint Arthroplasty: A Prospective Observational Study on 371 Patients.

BACKGROUND: Postoperative urinary retention (POUR) appears to be a common complication in lower limb joint arthroplasty; however, reports on its incidence vary. There is no general consensus on its definition and there is no scientific evidence on treatment principles. We performed a prospective observational study to establish the incidence of POUR and its risk factors, including the preoperative postvoid residual urine volume and the perioperative fluid balance, in fast-track total joint arthroplasty (TJA). The preoperative residual urine volume and the perioperative fluid balance have not been studied in previous literature in the context of TJA and POUR. METHODS: Three hundred eighty-one patients who underwent TJA of the lower limb were observed on developing POUR according to our local treatment protocol. Data on possible risk factors for POUR were collected including the perioperative fluid balance and the preoperative residual urine volume. RESULTS: In total, 46.3% of patients were catheterized. A preoperative postvoid urine retention is a significant predictor of catheterization for postoperative residual urine (P = .03). Spinal anesthesia was correlated with urinary retention (P = .01). There was no cause-effect relationship between POUR and the perioperative fluid balance. CONCLUSION: This study underlines POUR as a common complication in fast-track lower limb arthroplasty, with spinal anesthesia as a risk factor. A higher preoperative residual urine volume leads to higher postoperative residual volume, but not to a higher change in urinary retention. Increased perioperative fluid administration is not correlated with the incidence of POUR. Furthermore, there seems to be little rationale for monitoring residual urine volume both preoperatively and postoperatively.

Kneeling and standing up from a chair as performance-based tests to evaluate knee function in the high-flexion range: a randomized controlled trial comparing a conventional and a high-flexion TKA design.

BACKGROUND: We compared the functional outcome between conventional and high-flexion total knee arthroplasty (TKA) using kneeling and sit-to-stand tests at 1 year post-operative. In addition, the patient's daily functioning, pain and satisfaction were quantified using questionnaires. METHODS: We randomly assigned 56 patients to receive either a conventional or a high-flexion TKA. Primary outcomes were maximum flexion angle and maximum thigh-calf contact measured during kneeling at 1 year post operatively. Secondary outcomes were the angular knee velocity and ground reaction force ratio measured during sit-to-stand performance tests, and questionnaires. RESULTS: At one year post-operative, maximum knee flexion during kneeling was higher for the high-flexion TKA group (median 128.02° (range 108-146)) compared to the conventional TKA group (119.13° (range 72-135)) (p = 0.03). Maximum thigh-calf contact force was higher for the high flexion TKA group (median 17.82 N (range 2.98-114.64)) compared to the conventional TKA group (median 9.37 N (range 0.33-46.58))(p = 0.04). The sit-to-stand tests showed a significantly higher angular knee velocity in the conventional TKA group (12.12 rad/s (95%CI 0.34-23.91); p = 0.04). There were no significant differences between groups in ground reaction force ratios and patient-reported outcome scores. CONCLUSION: Although no differences were found in patient-reported outcome scores, differences in performance-based tests were clearly apparent. Standing up from a chair at 90° of knee flexion appeared to be easier for the conventional group. The kneeling test revealed significantly higher weight-bearing knee flexion for the high-flex group. Hence, if kneeling is an important activity for a patient a high-flex design may be recommendable. TRIAL REGISTRATION: The study was retrospectively registered in ClinicalTrials.gov under identifier NCT00899041 (date of registration: May 11, 2009).

More complications in uncemented compared to cemented hemiarthroplasty for displaced femoral neck fractures: a randomized controlled trial of 201 patients, with one year follow-up.

BACKGROUND: It is unclear whether cemented or uncemented hemiarthroplasty is the best treatment option in elderly patients with displaced femoral neck fractures. Previous randomized trials comparing cemented and uncemented hemiarthroplasty have conflicting results. We conducted a randomized controlled trial to compare cemented and uncemented hemiarthroplasty. METHODS: This multicenter parallel-randomized controlled trial included patients of 70 years and older with a displaced femoral neck fracture (Garden type III or IV). Inclusion was between August 2008 and June 2012. Patients were randomized between a cemented hemiarthroplasty, type Müller Straight Stem or an uncemented hemiarthroplasty, type DB-10. Primary outcomes were complications, operation time, functional outcome (measured by Timed-Up-and-Go (TUG) and Groningen Activity Restriction Scale (GARS)) and mid-thigh pain. Health Related Quality of Life (HRQoL, expressed with the SF-12) was measured as an secondary outcome. Follow up was 1 year. RESULTS: In total 201 patients were included in the study (91 uncemented, 110 cemented hemiarthroplasties) The uncemented group showed more major local complications (intra- and postoperative fractures and dislocations) odds ratio (95% confidence interval) 3.36 (1.40 to 8.11). There was no difference in mean operation time (57.3 vs 55.4 min). There were no differences in functional outcomes (TUG 12.8 (9.4) vs. 13.9 (9.0), GARS 43.2 (19.7) vs. 39.2 (16.5)) and mid-thigh pain (18.6 vs 21.6%). Physical component SF-12 HRQoLwas lower in the uncemented group (30.3 vs. 35.3 p < 0.05 after six weeks, 33.8 vs 38.5 p < 0.05 after 12 weeks). CONCLUSION: A cemented hemiarthroplasty in elderly patients with a displaced femoral neck fracture results in less complications compared to an uncemented hemiarthroplasty. TRIAL REGISTRATION: Netherlands Trial Registry; NTR 1508 , accepted date 27 okt 2008.

Complications of medial patellofemoral ligament reconstruction using two transverse patellar tunnels.

PURPOSE: The aim of this study was to report the complication rate after a medial patellofemoral ligament (MPFL) reconstruction using transverse patellar tunnels in a retrospective case series performed in a single institution. METHODS: Case series of 179 patients (192 knees) that had an MPFL reconstruction, with or without additional bony realignment procedures, between January 2009 and March 2015. Data were obtained from available patient charts. RESULTS: Thirty-nine complications (20.3 %) were registered. Twenty-seven of these (14.7 %) were minor. Seven patients (3.6 %) sustained a patellar fracture without adequate trauma. Male gender was a risk factor for patellar fracture (p < 0.001). Sixteen (8.1 %) reported recurrence of instability, of whom 10 (5.1 %) were defined as objective instability (reported dislocation and positive apprehension test). CONCLUSION: This is largest patient series to date in which the complications after a two tunnel MPFL reconstruction are described. The use of transverse patellar tunnels increases the risk of sustaining a patellar fracture. LEVEL OF EVIDENCE: IV.

Is it too early to move to full electronic PROM data collection?: A randomized controlled trial comparing PROM's after hallux valgus captured by e-mail, traditional mail and telephone.

BACKGROUND: Patient reported outcome measures (PROM's) after hallux valgus surgery are used to rate the effectiveness as perceived by the patient. The interpretability of these PROM's is highly dependent on participation rate. Data capture method may be an important factor contributing to the response rate. We investigated the effect on response rate of traditional paper mail, telephone and e-mail PROM's after hallux valgus surgery. METHODS: All consecutive patients operated between January and September 2013, were identified. Included patients were randomized by envelope in three groups: traditional pen and paper mail, e-mail and telephone. They were asked to fill in a FFI and EQ-5D. Two weeks later non-responders were sent a reminder. RESULTS: Of the 73 included patients, 25 were approached by mail, 24 by e-mail and 24 patients by telephone. The response rate on traditional mail was highest (88%), while response on e-mail was lowest (33%). Response rate on telephone was also high (79%). Response rate on traditional mail and telephone was significantly higher (p<0.001) than response on e-mail. CONCLUSIONS: Though electronic data collection has enormous potential, this study shows that e-mail yields unacceptable low response rates. It is too early to replace traditional pen-and-paper PROM's by electronic questionnaires.

Flexion and anterior knee pain after high flexion posterior stabilized or cruciate retaining knee replacement.

BACKGROUND: Special high-flexion prosthetic designs show a small increase in postoperative flexion compared to standard designs and some papers show increased anterior knee pain with these prosthesis. METHODS: A prospective double blind randomized controlled trial investigates the difference in flexion and anterior knee pain between standard and high-flexion total knee arthroplasty. In total 47 patients were randomly allocated to a standard cruciate retaining fixed bearing design (CR) in 23 patients and to a high-flexion posterior stabilized mobile bearing design (HF-PS) in 24 patients. RESULTS: The HF-PS did show a significantly higher passive postoperative flexion; 120.8° (SD 10.3°) vs. 112.0° (SD 9.5°) for the CR group (p = 0.004). The active postoperative flexion, VAS-pain score and Feller score did not show significant differences between both groups. Sub analysis with the HF-PS group showed a higher VAS-pain for the patients achieving ≥130° of flexion; 30.5 (SD 32.2) vs. 12.2 (SD 12.5) (p = 0.16). CONCLUSION: The present study showed a significant higher passive flexion in the high-flexion prosthesis compared to the standard prosthesis. However this difference disappeared when comparing active flexion. No difference in anterior knee pain was found between both groups.

Patient-reported outcome measures in hallux valgus surgery. A review of literature.

BACKGROUND: Up to a third of patients may be dissatisfied with the outcome of hallux valgus surgery. This stresses the importance of uniform and relevant outcome measures. The purpose of the current systematic review is to identify and rate available patient-reported outcome measures (PROMs) in hallux valgus surgery. METHODS: We performed a systematic literature search for outcome measures directed at hallux valgus. We searched electronic databases for relevant content according to the PRISMA standard. Eligible articles were used to give an overview of available PROMs, with qualitative evaluation of their properties. RESULTS: Twenty-eight eligible studies were included. Most adapted general health assessment tools, in studies on hallux valgus surgery, were the EQ5D and the SF-36 score. The visual analogue scale (VAS) was most cited as pain score. Three disease-specific outcome scores were identified: the Manchester-Oxford foot questionnaire (MOXFQ), the foot and ankle outcome score (FAOS) and the self-reported foot and ankle score (SEFAS). The MOXFQ showed the best psychometric properties. CONCLUSIONS: The MOXFQ scores best on positively rated qualities based on our criteria. The SEFAS may be a good alternative, however it contains less items which are regarded as important by patients with foot/ankle complaints. A relative drawback of the MOXFQ consists of the copyright licence. The VAS is the best pain score and the SF36 the best general health assessment tool. Availability in native languages and future research should lead to uniformity in application of these tools.

High complication rate after total knee and hip replacement due to perioperative bridging of anticoagulant therapy based on the 2012 ACCP guideline.

INTRODUCTION: An increasing amount of patients receiving total joint replacement require bridging of long-term anticoagulants. Guidelines, aimed at preventing complications, focus on thromboembolic events but not on bleeding complications. In this retrospective observational study, bleeding and thromboemoblic (TE) complications were evaluated in patients requiring perioperative heparin bridging of antithrombotic therapy during primary unilateral total hip or knee arthroplasty (THA and TKA). MATERIALS AND METHODS: Between January 2011 and June 2012, we identified all patients receiving low molecular weight heparin (LMWH) bridging during THA or TKA, according to our local protocol based on the ACCP guideline. Bleeding and TE complications, interventions and patient-related outcome measurements were used for evaluation. RESULTS: Among 972 patients 13 patients required bridging. Twelve patients (92%) experienced bleeding complications. An intervention was required in nine patients (69%). Seven patients received blood transfusion (54%). Nine patients (69%) developed a hematoma and two patients (15%) a periprosthetic joint infection. A total of five patients were re-admitted to hospital (39%) and the length of stay increased in all patients. No TE complications were observed in any of these patients. One year results of this patient group seem to be good. CONCLUSION: This study shows an alarmingly high complication rate in patients receiving LMWH bridging during elective TKA or THA surgery. All complications seem to be caused by, or secondary to bleeding. Patients need to be consulted about the risk of bleeding complications, and the risk of bleeding needs to be balanced over the risk of TE complications.

Dutch translation of the Kujala Anterior Knee Pain Scale and validation in patients after knee arthroplasty.

PURPOSE: To translate and validate the Kujala Anterior Knee Pain Scale (AKPS) in patients who have undergone total knee arthroplasty (TKA) or unicompartmental knee arthroplasty (UKA) and evaluate the internal consistency, construct validity and ceiling or floor effect. METHODS: After standard forward and backward translation was performed, 302 patients who have received a TKA or UKA filled out the AKPS together with Hospital for Special Surgery (HSS) patella score, visual analogue score (VAS) for pain, the Oxford 12-item questionnaire and the SF-36 at follow-up. The internal consistency was tested using Cronbach's α coefficient. The construct validity was assessed using Spearman's rank correlation (R) to test for correlations between the AKPS and VAS HSS, HSS patella score, VAS month, Oxford 12-item questionnaire and SF-36 subscales. Ceiling or floor effects are given in percentage of patients giving a maximum or minimum score. RESULTS: The internal reliability of the AKPS is acceptable with a Cronbach's α of 0.81 in patients after TKA or UKA. A high correlation was found between the AKPS and the Oxford 12-item questionnaire (R = 0.81). Moderate correlations were found with the VAS month (R = 0.63), HSS patella score (R = 0.51) and SF-36 subscales physical functioning (R = 0.59), role-physical (R = 0.59), bodily pain (R = 0.57). Other correlations were poor, therefore indicating a good convergent and divergent validity. Ceiling effects were observed for the HSS patella score (31 %), VAS HSS (51 %), VAS pain (19 %), SF36-RP (46 %), SF36-RE (80 %) and SF36-BP (24 %). No ceiling or floor effect was found for the AKPS, Oxford 12-item and the other SF36 domains. CONCLUSIONS: The AKPS appears to be reliable and valid in patients after knee arthroplasty, with no ceiling and floor effects, and can be used to assess anterior knee pain in patient who underwent joint replacement surgery.

High incidence of postoperative hypothermia in total knee and total hip arthroplasty: a prospective observational study.

Hypothermia, a body temperature of <36°C, has been shown to increase cardiac mortality, the incidence of postoperative infections, and the length of hospitalization following general surgery. However, studies assessing the incidence of hypothermia during primary total hip and total knee arthroplasty (THA and TKA) have not previously been demonstrated. In this prospective observational study, incidence of hypothermia was measured among 672 patients (415 underwent THA and 257 TKA). The incidence of hypothermia for THA and TKA was 26.3 and 28.0%, respectively. In conclusion, over a quarter of patients in this study are exposed to hypothermia. This study highlights the requirement for interventions to prevent peri-operative hypothermia.