Low back pain patients' experience and expectations: A qualitative study focusing on physiotherapist and physician care.

BACKGROUND: Low back pain (LBP) is a common and disabling musculoskeletal disorder. LBP experiences and expectations can vary from one person to another and influence their clinical outcomes. Despite the existence of numerous evidence-based treatment recommendations, LBP management in primary care remains challenging. This study aims to investigate the experiences and expectations of patients with LPB in primary care settings. METHODS: A qualitative study with an inductive thematic analysis was conducted. Semi-structured interviews were performed using individuals who had experienced LBP in the past year and had consulted a family physician (FP) or a physiotherapist (PT). RESULTS: Ten participants with LBP were interviewed (5 women, 5 men, mean age 49 ± 17). Five themes were identified: (1) I am always upset because I can't do anything; (2) I waited to consult; I thought it would go away; (3) I want to see what is going on with my LBP; (4) I want to see the person that will provide the right treatment; (5) I need support to get over it. Participants consulted when their pain was severe and disabling. They expected an imaging test to explain the cause of their LBP and placed more importance on the imaging test results than the FP's or PT's evaluation. Their opinions on care selection and being listened to were important for the participants. CONCLUSION: This study has highlighted the importance of the patient's point of view in their care. This consideration is important to ensure a comprehensive and collaborative approach with evidence-based practice care.

A Systematic Review of Clinical Practice Guidelines on the Diagnosis and Management of Various Shoulder Disorders.

OBJECTIVE: To perform a systematic review of clinical practice guidelines (CPGs) covering the management of common shoulder disorders. DATA SOURCES: A systematic search of CPGs on specific shoulder disorders was conducted up to August 2022 in relevant databases. STUDY SELECTION: Twenty-six CPGs on rotator cuff (RC) tendinopathy, RC tear, calcific tendinitis, adhesive capsulitis, glenohumeral (GH) instability, GH osteoarthritis, or acromioclavicular disorders published from January 2008 onward were screened and included. DATA EXTRACTION: CPGs methodological quality was assessed with the AGREE II checklist. All recommendations from CPGs were extracted and categorized by shoulder disorder and care components (evaluation, diagnostic imaging, medical, rehabilitation, and surgical treatments). After semantic analysis of the terminology, recommendations for each shoulder disorders were classified by 2 reviewers into "recommended," "may be recommended," or "not recommended." Disagreements were resolved by discussion until reviewers reached consensus. DATA SYNTHESIS: Only 12 CPGs (46%) were of high quality with major limitations related to the applicability and editorial independence of the guidelines. The initial evaluation of shoulder pain should include patient's history, subjective evaluation focused on red flags, and clinical examination. Magnetic resonance imaging is usually not recommended to manage early shoulder pain, and recommendations for X-rays are conflicting. Acetaminophen, oral non-steroidal anti-inflammatory drugs, and rehabilitation including exercises were recommended or may be recommended to treat all shoulder pain disorders. Guidelines on surgical management recommendations differed; for example, 6 CPGs reported that acromioplasty was recommended or may be recommended in chronic RC tendinopathy, whereas 4 CPGs did not recommend it. CONCLUSIONS: Recommendations vary for diagnostic imaging, conservative vs surgical treatment to manage shoulder pain, although several care components are consensual. The development of evidence-based, rigorous CPGs with a valid methodology and transparent reporting is warranted to improve overall shoulder pain care.

"I wanted to know what was hurting so much": a qualitative study exploring patients' expectations and experiences with primary care management.

BACKGROUND: The management of shoulder pain is challenging for primary care clinicians considering that 40% of affected individuals remain symptomatic one year after initial consultation. Developing tailored knowledge mobilization interventions founded on evidence-based recommendations while also considering patients' expectations could improve primary care for shoulder pain. The aim of this qualitative study is to explore patients' expectations and experiences of their primary care consultation for shoulder pain. METHODS: In this qualitative study, participants with shoulder pain and having consulted a primary care clinician in the past year were interviewed. All the semi-structured interviews were transcribed verbatim, and inductive thematic analysis was performed to identify themes related to the participants' expectations and experiences of primary care consultations for shoulder pain. RESULTS: Thirteen participants with shoulder pain were interviewed (8 women, 5 men; mean age 50 ± 12 years). Eleven of them initially consulted a family physician or an emergency physician, and two participants initially consulted a physiotherapist. Four overarching themes related to patients' expectations and experiences were identified from our thematic analysis: 1) I can't sleep because of my shoulder; 2) I need to know what is happening with my shoulder; 3) But… we need to really see what is going on to help me!; and 4) Please take some time with me so I can understand what to do!. Several participants waited until they experienced a high level of shoulder pain before making an appointment since they were not confident about what their family physician could do to manage their condition. Although some participants felt that their physician took the time to listen to their concerns, many were dissatisfied with the limited assessment and education provided by the clinician. CONCLUSIONS: Implementing evidence-based recommendations while considering patients' expectations is important as it may improve patients' satisfaction with healthcare. Several participants reported that their expectations were not met, especially when it came to the explanations provided. One unexpected finding that emerged from this study was the waiting period between the onset of shoulder pain and when patients decided to consult their primary care clinician.

Knowledge and appropriateness of care of family physicians and physiotherapists in the management of shoulder pain: a survey study in the province of Quebec, Canada.

BACKGROUND: Shoulder pain is difficult to diagnose and treat with half of those affected still symptomatic six months after initial consultation. This may be explained by primary care management not conforming to evidence-based practice. This survey evaluated physiotherapists (PTs) and family physicians' (FPs) knowledge and appropriateness of care in shoulder pain management. METHODS: A survey sent to PTs and FPs in the province of Quebec, Canada presented four clinical vignettes with cases of rotator cuff (RC) tendinopathy, acute full-thickness RC tear, adhesive capsulitis and traumatic anterior glenohumeral instability. Respondents indicated diagnosis, indications for imaging, specialists' referrals, and choice of treatments. Answers were compared to recommendations from clinical practice guidelines (CPGs). Participants' responses were compared between types of providers with Fisher's exact test. RESULTS: Respondents (PTs = 175, FPs = 76) were mostly women with less than ten years of experience. More than 80% of PTs and 84% of FPs correctly diagnosed cases presented. Despite this practice not being recommended, more FPs than PTs recommended an imaging test in the initial management of RC tendinopathy (30% compared to 13%, p = 0.001) and adhesive capsulitis (51% compared to 22%, p = 0.02). For full-thickness RC tear and shoulder instability, up to 72% of FPs and 67% of PTs did not refer to a specialist for a surgical opinion, although recommended by CPGs. For RC tendinopathy, 26% of FPs and 2% of PTs (p < 0.001) would have prescribed a corticosteroid infiltration, which is not recommended in the initial management of this disorder. For adhesive capsulitis, significantly more FPs (76%) than PTs (62%) (p < 0.001) suggested an intra-articular corticosteroid infiltration, as recommended by CPGs. For all presented vignettes, up to 95% of family physicians adequately indicated they would refer patients for physiotherapy. In prioritizing rehabilitation interventions, up to 42% of PTs did not consider active exercises as a priority and up to 65% selected passive modalities that are not recommended for all shoulder pain vignettes. CONCLUSIONS: Most FPs and PTs were able to make adequate diagnoses and select appropriate treatments for shoulder pain, but practices opposed to evidence-based recommendations were chosen by several respondents. Further training of FPs and PTs may be needed to optimize primary care management of different shoulder disorders.

Diagnosing, Managing, and Supporting Return to Work of Adults With Rotator Cuff Disorders: A Clinical Practice Guideline.

OBJECTIVE: To develop a clinical practice guideline covering the assessment, management, and return to work of adults with rotator cuff disorders. DESIGN: Clinical practice guideline. METHODS: Using systematic reviews, appraisal of the literature, and an iterative approach to obtain consensus from key stakeholders, clinical recommendations and algorithms were developed in the context of the health care system and work environment of the province of Quebec (Canada). RESULTS: Recommendations (n = 73) and clinical decision algorithms (n = 3) were developed to match the objectives. The initial assessment should include the patient's history, a subjective assessment, and a physical examination. Diagnostic imaging is only necessary in select circumstances. Acetaminophen, nonsteroidal anti-inflammatory drugs, and injection therapies may be useful to reduce pain in the short term. Clinicians should prescribe an active and task-oriented rehabilitation program (exercises and education) to reduce pain and disability in adults with rotator cuff disorders. Subacromial decompression is not recommended to treat rotator cuff tendinopathy. Surgery is appropriate for selected patients with a full-thickness rotator cuff tear. A return-to-work plan should be developed early, in collaboration with the worker and other stakeholders, and must combine multiple strategies to promote return to work. CONCLUSION: This clinical practice guideline was developed to assist the multidisciplinary team of clinicians who provide health care for adults with a rotator cuff disorder. The CPG guides clinical decisionmaking for diagnosis and treatment, and planning for successful return to work. J Orthop Sports Phys Ther 2022;52(10):647-664. Epub: 27 July 2022. doi:10.2519/jospt.2022.11306.

Physiotherapists' ability to diagnose and manage shoulder disorders in an outpatient orthopedic clinic: results from a concordance study.

BACKGROUND: Advanced practice physiotherapy has emerged as a promising solution to improve health care access because access to orthopedic care is limited in several countries. However, evidence supporting advanced practice physiotherapy models for the management of shoulder pain remains scarce. The purpose of this study was to establish diagnostic, surgical triage, and medical imaging agreement between advanced practice physiotherapists (APPs) and orthopedic surgeons (OSs) for the management of patients with shoulder disorders in an outpatient orthopedic clinic. METHODS: Patients referred to an OS for shoulder complaints were recruited and independently assessed by an OS and an APP. Each provider completed a standardized form indicating diagnosis, imaging test requests, and triage of surgical candidates. Patient satisfaction with care was recorded with the 9-item Visit-Specific Satisfaction Questionnaire (VSQ-9). Inter-rater concordance was calculated with the Cohen κ, prevalence-adjusted bias-adjusted κ, and associated 95% confidence interval (CI). We used χ2 tests to compare differences between providers in terms of treatment plan options and Student t tests to compare patient satisfaction between providers. RESULTS: Fifty participants were evaluated. Good diagnostic agreement was observed between providers (κ, 0.80; 95% CI, 0.67-0.93). Agreement for triage of surgical candidates was moderate (κ, 0.46; 95% CI, 0.21-0.71) as APPs tended to refer patients more often to OSs for further evaluation. Imaging test request agreement was moderate as well (κ, 0.42; 95% CI, 0.19-0.66). Patient satisfaction with care was high, with no significant differences found between providers (P = .70). CONCLUSION: APPs could improve access to orthopedic care for shoulder disorders by safely initiating patient care without compromising satisfaction. These results support further development and evaluation of APP care for orthopedic patients presenting with shoulder disorders.

Shoulder Rotator Cuff Disorders: A Systematic Review of Clinical Practice Guidelines and Semantic Analyses of Recommendations.

OBJECTIVES: To perform a systematic review of clinical practice guidelines (CPGs) and semantic analysis of specific clinical recommendations for the management of rotator cuff disorders in adults. DATA SOURCES: A systematic bibliographic search was conducted up until May 2018 in Medline, Embase, and Physiotherapy Evidence Database, or PEDro, databases, in addition to 12 clinical guidelines search engines listed on the Appraisal of Guidelines for Research and Evaluation (AGREE) website. STUDY SELECTION: Nine CPGs on the management of rotator cuff disorders in adults or workers, available in English or French, and published from January 2008 onward, were included and screened by 2 independent reviewers. DATA EXTRACTION: CPG methodology was assessed with the AGREE II checklist. A semantic analysis was performed to compare the strength of similar recommendations based on their formulation. The recommendations were categorized in a standardized manner considering the following 4 levels: "essential," "recommended," "may be recommended," and "not recommended." DATA SYNTHESIS: Methodological quality was considered high for 3 CPGs and low for 6. All CPGs recommended active treatment modalities, such as an exercise program in the management of rotator cuff disorders. Acetaminophen or nonsteroidal anti-inflammatory drug prescriptions and corticosteroid injections were presented as modalities that may be recommended to decrease pain. Recommendations related to medical imagery and surgical opinion varied among the guidelines. The most commonly recommended return-to-work strategies included intervening early, use of a multidisciplinary approach, and adaptation of work organization. CONCLUSIONS: Only 3 CPGs were of high quality. The development of more rigorous CPGs is warranted.

Development of an Electromechanical Grade to Assess Human Knee Articular Cartilage Quality.

Quantitative assessments of articular cartilage function are needed to aid clinical decision making. Our objectives were to develop a new electromechanical grade to assess quantitatively cartilage quality and test its reliability. Electromechanical properties were measured using a hand-held electromechanical probe on 200 human articular surfaces from cadaveric donors and osteoarthritic patients. These data were used to create a reference electromechanical property database and to compare with visual arthroscopic International Cartilage Repair Society (ICRS) grading of cartilage degradation. The effect of patient-specific and location-specific characteristics on electromechanical properties was investigated to construct a continuous and quantitative electromechanical grade analogous to ICRS grade. The reliability of this novel grade was assessed by comparing it with ICRS grades on 37 human articular surfaces. Electromechanical properties were not affected by patient-specific characteristics for each ICRS grade, but were significantly different across the articular surface. Electromechanical properties varied linearly with ICRS grade, leading to a simple linear transformation from one scale to the other. The electromechanical grade correlated strongly with ICRS grade (r = 0.92, p < 0.0001). Additionally, the electromechanical grade detected lesions that were not found visually. This novel grade can assist the surgeon in assessing human knee cartilage by providing a quantitative and reliable grading system.

Electromechanical probe and automated indentation maps are sensitive techniques in assessing early degenerated human articular cartilage.

Recent advances in the development of new drugs to halt or even reverse the progression of Osteoarthritis at an early-stage requires new tools to detect early degeneration of articular cartilage. We investigated the ability of an electromechanical probe and an automated indentation technique to characterize entire human articular surfaces for rapid non-destructive discrimination between early degenerated and healthy articular cartilage. Human cadaveric asymptomatic articular surfaces (four pairs of distal femurs and four pairs of tibial plateaus) were used. They were assessed ex vivo: macroscopically, electromechanically, (maps of the electromechanical quantitative parameter, QP, reflecting streaming potentials), mechanically (maps of the instantaneous modulus, IM), and through cartilage thickness. Osteochondral cores were also harvested from healthy and degenerated regions for histological assessment, biochemical analyses, and unconfined compression tests. The macroscopic visual assessment delimited three distinct regions on each articular surface: Region I was macroscopically degenerated, region II was macroscopically normal but adjacent to regions I and III was the remaining normal articular surface. Thus, each extracted core was assigned to one of the three regions. A mixed effect model revealed that only the QP (p < 0.0001) and IM (p < 0.0001) were able to statistically discriminate the three regions. Effect size was higher for QP and IM than other assessments, indicating greater sensitivity to distinguish early degeneration of cartilage. When considering the mapping feature of the QP and IM techniques, it also revealed bilateral symmetry in a moderately similar distribution pattern between bilateral joints. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:858-867, 2017.

E2F1 and TFDP1 Regulate PITX1 Expression in Normal and Osteoarthritic Articular Chondrocytes.

We previously reported a loss-of-PITX1 expression in patients suffering of knee/hip osteoarthritis (OA). Search for the mechanism underlying this event led us to discover that PITX1 repression was triggered by the aberrant nuclear accumulation of Prohibitin (PHB1), an E2F1 co-repressor, in OA articular chondrocytes. In the current study, we assessed in details the involvement of E2F transcription factors in regulating PITX1 expression. We also analyzed other genes that are similarly regulated by E2F in regard to osteoarthritis. The transcriptional regulation of the PITX1 promoter by E2F1 was analyzed with the luciferase reporter assay, and chromatin immunoprecipitation assays, which confirmed direct E2F1-PITX1 interactions. The probable binding sites for E2F1 in the PITX1 promoter were identified by DNA pulldown experiments. In silico and in vitro analyses show that the PITX1 proximal promoter region contains 2 specific sequences that are bound by E2F1. Overexpression of E2F1 enhances PITX1 promoter activity and mRNA transcription. In primary control and osteoarthritis chondrocytes, real time RT-PCR was used to measure the mRNA expression levels of candidate genes under E2F1 transcriptional control. Transcription Factor Dp-1 (TFDP1) knockdown experiments confirmed that the E2F1-TFDP1 complex regulates PITX1. Knockdown of TFDP1, an E2F1 dimerization partner, inhibits the activating effect of E2F1 and reduces both PITX1 promoter activity and mRNA transcription. Real time RT-PCR results reveal reduced expression of TFDP1 and a similar downregulation of their targets PITX1, BRCA1, CDKN1A, and RAD51 in mid-stage OA chondrocytes. Collectively, our data define a previously uncharacterized role for E2F1 and TFDP1 in the transcriptional regulation of PITX1 in articular chondrocytes. Additional E2F1 targets may be affected in OA pathogenesis.

Total knee arthroplasty with a novel navigation system within the surgical field.

Total knee arthroplasty is a common procedure, and current navigation systems are gradually gaining acceptance for improving surgical accuracy and clinical outcomes. A new navigation system used within the surgical field, iAssist, has demonstrated reproducible accuracy in component alignment. All orientation information is captured by small electronic pods and transmitted via a local wireless network, which directs the surgical workflow automatically to the femoral and tibial resection instruments. This simple and accurate navigation system used completely in the surgical field, without optical trackers or preoperative imaging, seems to be the latest generation of smart instrumentation for total knee arthroplasty.

Nuclear accumulation of prohibitin 1 in osteoarthritic chondrocytes down-regulates PITX1 expression.

OBJECTIVE: To decipher the molecular mechanisms down-regulating PITX1 expression in primary osteoarthritis (OA). METHODS: The functional activity of different PITX1 promoter regions was assessed by luciferase reporter assay. Tandem mass spectrometry coupled to protein sequencing was performed using nuclear extracts prepared from OA chondrocytes, in order to identify proteins bound to DNA regulatory elements. Expression analyses of selected candidate proteins were performed by real-time reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry methods, using cartilage sections and articular chondrocytes from non-OA control subjects and patients with OA. Gain-of-function and loss-of-function experiments were performed in normal and OA chondrocytes, respectively, to study their effects on PITX1 regulation. The results were validated by real-time RT-PCR and immunohistochemistry in STR/Ort mice, a well-known animal model of OA. RESULTS: PITX1 promoter analyses led to the identification of prohibitin 1 (PHB1) bound to a distal E2F1 transcription factor site. Aberrant accumulation of PHB1 was detected in the nuclei of OA articular chondrocytes, and overexpression of PHB1 in control cells was sufficient to inhibit endogenous PITX1 expression at the messenger RNA and protein levels. Conversely, knockdown of PHB1 in OA articular chondrocytes resulted in up-regulation of PITX1. Studies of early molecular changes in STR/Ort mice revealed a similar nuclear accumulation of PHB1, which correlated with Pitx1 repression. CONCLUSION: Collectively, these data define an unrecognized role for PHB1 in repressing PITX1 expression in OA chondrocytes.

Axial load-bearing capacity of an osteochondral autograft stabilized with a resorbable osteoconductive bone cement compared with a press-fit graft in a bovine model.

BACKGROUND: Osteochondral autografts in mosaicplasty are inserted in a press-fit fashion, and hence, patients are kept nonweightbearing for up to 2 months after surgery to allow bone healing and prevent complications. Very little has been published regarding alternative fixation techniques of those grafts. HYPOTHESIS: Osteochondral autografts stabilized with a resorbable osteoconductive bone cement would have a greater load-bearing capacity than standard press-fit grafts. STUDY DESIGN: Controlled laboratory study. METHODS: Biomechanical testing was conducted on 8 pairs of cadaveric bovine distal femurs. For the first 4 pairs, 6 single osteochondral autografts were inserted in a press-fit fashion on one femur. On the contralateral femur, 6 grafts were stabilized with a calcium triglyceride osteoconductive bone cement. For the 4 remaining pairs of femurs, 4 groups of 3 adjacent press-fit grafts were inserted on one femur, whereas on the contralateral femur, grafts were cemented. After a maturation period of 48 hours, axial loading was applied on all single grafts and on the middle graft of each 3-in-a-row series. RESULTS: For the single-graft configuration, median loads required to sink the press-fit and cemented grafts by 2 and 3 mm were 281.87 N versus 345.56 N (P = .015) and 336.29 N versus 454.08 N (P = .018), respectively. For the 3-in-a-row configuration, median loads required to sink the press-fit and cemented grafts by 2 and 3 mm were 260.31 N versus 353.47 N (P = .035) and 384.83 N versus 455.68 N (P = .029), respectively. CONCLUSION: Fixation of osteochondral grafts using bone cement appears to improve immediate stability over the original mosaicplasty technique for both single- and multiple-graft configurations. CLINICAL RELEVANCE: Achieving greater primary stability of osteochondral grafts could potentially accelerate postoperative recovery, allowing early weightbearing and physical therapy.

Objective grading of the pivot shift phenomenon using a support vector machine approach.

The pivot shift test is the only clinical test that has been shown to correlate with subjective criteria of knee joint function following rupture of the anterior cruciate ligament. The grade of the pivot shift is important in predicting short- and long-term outcome. However, because this grade is established by a clinician in a subjective manner, the pivot shift's value as a clinical tool is reduced. The purpose of this study was to develop a system that will objectively grade the pivot shift test based on recorded knee joint kinematics. Fifty-six subjects with different degrees of knee joint stability had the pivot shift test performed by one of eight different orthopaedic surgeons while their knee joint kinematics were recorded. A support vector machine based algorithm was used to objectively classify these recordings according to a clinical grade. The grades established by the surgeons were used as the gold standard for the development of the classifier. There was substantial agreement between our classifier and the surgeons in establishing the grade (weighted kappa=0.68). Seventy-one of 107 recordings (66%) were given the same grade and 96% of the time our classifier was within one grade of that given by the surgeons. Moreover, grades 0 and 1 were distinguished from grade 2 to 3 with 86% sensitivity and 90% specificity. Our results show the feasibility of automatically grading the pivot shift in a manner similar to that of an experienced clinician, based on knee joint kinematics.

Design and dynamic culture of 3D-scaffolds for cartilage tissue engineering.

Engineered scaffolds for tissue-engineering should be designed to match the stiffness and strength of healthy tissues while maintaining an interconnected pore network and a reasonable porosity. In this work, we have used 3D-plotting technique to produce poly-L-Lactide macroporous scaffolds with two different pore sizes. The ability of these macroporous scaffolds to support chondrocyte attachment and viability were compared under static and dynamic loading in vitro. Moreover, the 3D-plotting technique was combined with porogen-leaching, leading to macro/microporous scaffolds, so as to examine the effect of microporosity on the level of cell attachment and viability under similar loading condition. Canine chondrocytes' cells were seeded onto the scaffolds with different topologies, and the constructs were cultured for up to 2 weeks under static conditions or in a bioreactor under dynamic compressive strain of 10% strain, at a frequency of 1 Hz. The attachment and cell growth of chondrocytes were examined by scanning electron microscopy and by 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. A significant difference in cell attachment was observed in macroporous scaffolds with different pore sizes after 1, 7, and 14 days. Cell viability in the scaffolds was enhanced with decreasing pore size and increasing microporosity level throughout the culture period. Chondrocyte viability in the scaffolds cultured under dynamic loading was significantly higher (p<0.05) than the scaffolds cultured statically. Dynamic cell culture of the scaffolds improved cell viability and decreased the time of in vitro culture when compared to statically cultured constructs. Optimizing the culture conditions and scaffold properties could generate optimal tissue/constructs combination for cartilage repair.

Accounting for velocity of the pivot shift test manoeuvre decreases kinematic variability.

The pivot shift test is the only clinical test which correlates with knee function following rupture of the ACL. A grade is given to the pivot shift in a subjective manner, leading to efforts to quantify the bone movements and correlate them to the grade. However, the dynamic and unconstrained nature of the manoeuvre introduces important kinematic variability. Our main objective was to develop a method to lessen the variability attributable to clinician technique, therefore increasing inter-grade differences. Three different orthopaedic surgeons each performed the pivot shift test on 12 subjects. Knee joint kinematics were recorded using electromagnetic motion capture devices. Inter-clinician variability was quantified and a method was developed to diminish it, using the angular velocity of flexion. This method was then applied to a larger population composed of 127 knees with various degrees of instability, evaluated by one of eight different orthopaedic surgeons. The clinical grades given by the clinicians were in almost perfect agreement (kappa=0.83). Normalization of kinematic parameters using the angular velocity of knee joint flexion produced by the clinicians reduced the intra-clinician variability by 20%, resulting in an intra-class correlation coefficient (ICC) of 0.52, up from 0.41 before normalization. This allowed for more significant differences between the grades of pivot shift. Simple normalisation of pivot shift kinematics using the angular velocity of flexion reduces clinician-related variability and allows for significant differences between the different grades. These results are an important step towards developing an objective measurement tool for the pivot shift phenomenon.

Feature selection using a principal component analysis of the kinematics of the pivot shift phenomenon.

The pivot shift test reproduces a complex instability of the knee joint following rupture of the anterior cruciate ligament. The grade of the pivot shift test has been shown to correlate to subjective criteria of knee joint function, return to physical activity and long-term outcome. This severity is represented by a grade that is attributed by a clinician in a subjective manner, rendering the pivot shift test poorly reliable. The purpose of this study was to unveil the kinematic parameters that are evaluated by clinicians when they establish a pivot shift grade. To do so, eight orthopaedic surgeons performed a total of 127 pivot shift examinations on 70 subjects presenting various degrees of knee joint instability. The knee joint kinematics were recorded using electromagnetic sensors and principal component analysis was used to determine which features explain most of the variability between recordings. Four principal components were found to account for most of this variability (69%), with only the first showing a correlation to the pivot shift grade (r = 0.55). Acceleration and velocity of tibial translation were found to be the features that best correlate to the first principal component, meaning they are the most useful for distinguishing different recordings. The magnitudes of the tibial translation and rotation were amongst those that accounted for the least variability. These results indicate that future efforts to quantify the pivot shift should focus more on the velocity and acceleration of tibial translation and less on the traditionally accepted parameters that are the magnitudes of posterior translation and external tibial rotation.

Pluronic F-127 as a cell carrier for bone tissue engineering.

The objective of this study is to report the effect of Pluronic F-127 on osteoblast viability and phenotype maintenance in vitro. MG-63 cells are suspended in Pluronic F-127, and MTT assay, alkaline phosphatase activity, prostaglandin E(2) production, collagen-I, and cyclo-oxygenase-2 expression are assessed up to 6 days. Pluronic F-127 leads to a significant decrease in osteoblast viability throughout the 6-day experiment, without altering osteoblast phenotype. The addition of platelet-rich plasma to the polymer/cell construct leads to increased cell survival. When supplemented with bioactive factors, Pluronic F-127 could potentially be used as a cell carrier in bone tissue engineering.