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Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_3 | Pages 52 - 52
1 Mar 2021
Karatzas N Corban J Bergeron S Fevens T Martineau P
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A quick, portable and reliable tool for predicting ACL injury could be an invaluable instrument for athletes, coaches, and clinicians. The gold standard, Vicon motion analysis, despite having a high sensitivity and risk specificity, is not practical for coaches or clinicians to use on a routine basis for assessing athletes. The present study validated the Kinect device to the currently used method of chart review in predicting athletes at high risk.

A total of 114 participants were recruited from both the men and women McGill Varsity Sports Program. 69 males and 45 female athletes were evaluated to assess the specificity and sensitivity of the Kinect device in predicting athletes at high risk of injury. Each athlete performed three-drop vertical jumps off of a 31cm box and the data was recorded and risk score was generated. Generation of this data is done by our uniquely programmed software that measures landing angles at different time frames and compares live results to previously known data of injured athletes. A chart review was then performed by a clinician, blinded to these risk scores, to risk stratify the same athletes as high or low risk of ACL injury based on their medical charts. Data reviewed incorporated pre-season physical exams along with documented known risk factors for ACL injury, including previous knee injuries, family history of ACL injury, gender, sport, and BMI. Positive risk factors were assigned one point while negative risk factors assigned zero points.

The Kinect device, powered by our software, identified 40 athletes as having a high-risk score (> 55%), and subsequently, five (4.39%) sustained an ACL injury by the end of their respective sport seasons. Two male and two female basketball players along with one male soccer player sustained non-contact ACL injuries. Given that all five of the injured athletes were in the cohort of 40 identified as high risk by the Kinect, this yielded a sensitivity of 100% for the device. As for the specificity, the Kinect computed 35 false positives, yielding a specificity of 68% for the duration of the study. The medical chart review identified 36 athletes as high risk and 60 as being low risk of ACL injury. Four of the athletes that sustained an ACL injury were in the group of 36 identified as high risk by the clinician. However, one of the five participants who sustained an ACL injury was not captured by the medical chart assessment, yielding a sensitivity of 80% and a specificity of 65% for the clinician.

When it comes to injury prediction, it is preferred to have a high sensitivity even if the specificity is slightly lower as this ensures that all athletes who are at risk will be captured. Our data demonstrated that the chart analysis provided one false negative and led to missing one high-risk athlete who ended up sustaining an ACL injury. Based on the comparison of sensitivity and specificity, the Kinect system provides a slightly better predictive analysis for predicting ACL injury compared to chart review.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_III | Pages 372 - 372
1 Jul 2011
Potoupnis M Iakovou J Kenanidis E Pellios S Karatzas N Kapetanos G
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Aggrecan is a major constituent of joint cartilage. A prominent feature in joint disease is loss of Aggrecan. The aim of this study was to assess the relation between the concentration of Aggrecan in the synovial fluid of knee joint and this of the peripheral blood in patients suffering from end stage knee osteoarthritis

37 postmenopausal women suffering from end-stage idiopathic knee osteoarthritis, scheduled to undergo Total Knee Arthroplasty (TKA), were enrolled in this study. Their mean age was 69.8 years (range: 49–81 years). The serum levels of Aggrecan were evaluated one day pre-operatively whether synovial fluid levels from fluid taken during the operation day.

Patients suffering from any endocrine disorder, rheumatoid or other secondary arthritis or any other disease that could interfere with the cartilage homeostasis were excluded from the study. Concentrations of aggrecan turnover were measured with appropriate assays.

Moderate correlation between serum and synovial fluid concentrations of aggrecan was revealed (r= 0, 337, p=0,197)

Serum levels of aggrecan may be related to the synovial concentration of Aggrecan in patients suffering from end stage knee osteoarthritis. The possible significant relationship between these markers may be of value in assessing cartilage degradation in patients with involvement of a single joint with a blood sample. However this correlation needs to be further investigated


Background: The clinical significance of bone turnover markers is well recognized, at least in several diseases affecting the bone metabolism. However, their clinical significance (if any) remains still unknown in patients undergoing Total Joint Arthroplasty (TJA). Changes in the levels of some markers have been reported in the early postoperative period after Total Hip Arthroplasty; however their exact postoperative course has not been clearly documented yet. In order to assess the clinical value of biochemical markers when trying to determine the fixation of orthopaedic implants, it is necessary to clarify their normal postoperative course.

The aim of this study was to extend the evaluation of the course of bone turnover markers over a longer period (12 postoperative months) following a TJA, and to assess the postoperative course for two of them (RANKL and Osteoprotegerin) for the first time.

Methods: The serum levels of RANKL, Osteocalcin, Osteoprotegerin and bALP were determined one day preoperatively and several times during the first postoperative year in patients suffering from idiopathic osteoarthritis that underwent total knee (n=23) and hip arthroplasties (n=24).

Results: There were statistically significant changes in the serum levels of all markers over time (p< 0,001). RANKL values initially increased and then gradually decreased. Following an initial decrease, Osteocalcin values continuously increased until the 2nd postoperative month and then continuously decreased. Osteoprotegerin initially increased, then decreased until the 4th postoperative month and then increased again reaching a peak 8 months postoperatively. Bone-specific ALP decreased until the 7th postoperative day. After that time it continuously increased, reaching a peak at the 8th month, and then it gradually decreased. There were no major differences in the postoperative course of all markers between the hip and knee arthroplasties.

Conclusions: The levels of all bone markers did not uniformly ‘return’ to their preoperative values one year postoperatively. A one-year period is not enough, when assessing an orthopaedic implant’s fixation with the use of bone turnover markers.