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Biomechanical analysis of knee laxity with isolated anteromedial or posterolateral bundle-deficient anterior cruciate ligament

Kondo E, Merican AM, Yasuda K, Amis AA

Arthroscopy, 2014 Mar;30(3):335-43.
PMID: 24581258 DOI: 10.1016/j.arthro.2013.12.003

The purpose of this study was to clarify the changes in the kinematics of the knee that result from isolated deficiency of the anteromedial (AM) or posterolateral (PL) bundle.

Matched MeSH terms: Femur/physiopathology
Geometric variable designs of cam/post mechanisms influence the kinematics of knee implants

Fallahiarezoodar A, Abdul Kadir MR, Alizadeh M, Naveen SV, Kamarul T

Knee Surg Sports Traumatol Arthrosc, 2014 Dec;22(12):3019-27.
PMID: 25149643 DOI: 10.1007/s00167-014-3227-7

PURPOSE: Reproducing the femoral rollback through specially designed mechanism in knee implants is required to achieve full knee function in total knee arthroplasty. Most contemporary implants use cam/post mechanism to replace the function of Posterior Cruciate Ligament. This study was aimed to determine the most appropriate cam and post designs to produce normal femoral rollback of the knee.
METHODS: Three different cams (triangle, ellipse, and circle) and three different posts (straight, convex, concave) geometries were considered in this study and were analysed using kinematic analyses. Femoral rollback did not occur until reaching 50° of knee flexion. Beyond this angle, two of the nine combinations demonstrate poor knee flexion and were eliminated from the study.
RESULTS: The combination of circle cam with concave post, straight post and convex post showed 15.6, 15.9 and 16.1 mm posterior translation of the femur, respectively. The use of ellipse cam with convex post and straight post demonstrated a 15.3 and 14.9 mm femoral rollback, whilst the combination of triangle cam with convex post and straight post showed 16.1 and 15.8 mm femoral rollback, respectively.
CONCLUSION: The present study demonstrates that the use of circle cam and convex post created the best femoral rollback effect which in turn produces the highest amount of knee flexion. The findings of the study suggest that if the design is applied for knee implants, superior knee flexion may be possible for future patients.
LEVEL OF EVIDENCE: IV.

Matched MeSH terms: Femur/physiopathology
Bone-related complications of transfusion-dependent beta thalassemia among children and adolescents

Mirhosseini NZ, Shahar S, Ghayour-Mobarhan M, Banihashem A, Kamaruddin NA, Hatef MR, et al.

J. Bone Miner. Metab., 2013 Jul;31(4):468-76.
PMID: 23475127 DOI: 10.1007/s00774-013-0433-1

Thalassemia and the blood transfusion complications associated with it predispose children to poor bone health. This study was conducted to determine the prevalence of bone-related abnormalities and identify the bone health predictors within this population. One hundred and forty transfusion-dependent beta thalassemic subjects 8-18 years old in Mashhad, Iran, participated in this cross-sectional study. Anthropometric measures, dietary intake, bone-related biomarkers and bone densitometry, were assessed. The incidence of underweight and short stature was 33.6 and 41.4 %, respectively, which were indicators of malnutrition among thalassemic subjects in this study. Low bone density was detected in the lumbar spine and femoral region in 82 and 52 % of subjects, respectively. Hypocalcemia and hypophosphatemia were seen in 22 and 18.2 %, whilst vitamin D deficiency was present in more than 85 % of thalassemic children and adolescents. The relationships between weight, height and other anthropometric indices, serum calcium and bone markers, intake of macronutrients, zinc and vitamin E with bone mineral density (BMD) and bone mineral content (BMC) in the lumbar spine and femoral area were positively related, indicating that better nutritional status were associated with higher BMD and BMC values. Puberty, gender and serum osteocalcin were negative predictors for BMD and BMC values, whereas age, weight and height were the positive predictors. High incidence of low bone density and deficit in other aspects of bone health among thalassemia patients makes routine bone health assessment necessary for this vulnerable group. Considering influencing factors, dietary counseling and preventive supplementation therapy for this high risk group of children and adolescents may be necessary, although this should be assessed by intervention studies.

Matched MeSH terms: Femur/physiopathology
The use of delta-tocotrienol and lovastatin for anti-osteoporotic therapy

Abdul-Majeed S, Mohamed N, Soelaiman IN

Life Sci, 2015 Mar 15;125:42-8.
PMID: 25534439 DOI: 10.1016/j.lfs.2014.12.012

Statins are competitive inhibitors of HMGCoA reductase and are commonly used as antihypercholesterolemic agents. Experimental studies clearly demonstrate the beneficial effects of statins on bone. Tocotrienols have also been shown to have anti-osteoporotic effects on the skeletal system. This study was conducted to observe the effect of a combination of delta-tocotrienol and lovastatin on structural bone histomorphometry and bone biomechanical strength in a postmenopausal rat model at clinically tolerable doses, and to compare it with the effect of delta-tocotrienol or lovastatin.

Matched MeSH terms: Femur/physiopathology
Comparable clinical and radiological outcomes between anatomical and high femoral tunnels in posterior cruciate ligament reconstruction

Yoon KH, Kim JS, Park JY, Park SY, Kiat RYD, Kim SG

Knee Surg Sports Traumatol Arthrosc, 2021 Jun;29(6):1936-1943.
PMID: 32914218 DOI: 10.1007/s00167-020-06266-0

PURPOSE: To compare clinical and radiological outcomes and failure rates between anatomical and high femoral tunnels in remnant-preserving single-bundle posterior cruciate ligament (PCL) reconstruction.
METHODS: 63 patients who underwent remnant-preserving single-bundle PCL reconstruction between 2011 and 2018 with a minimum 2-year follow-up were retrospectively reviewed. Patients were divided into two groups according to the femoral tunnel position: group A (33 patients with anatomical femoral tunnel) and group H (30 patients with high femoral tunnels). The femoral tunnel was positioned at the center (group A) or upper margin (group H) of the remnant anterolateral bundle. The position of the femoral tunnel was evaluated using the grid method on three-dimensional computed tomography. Clinical and radiological outcomes and failure rates were compared between the groups at the 2-year follow-up.
RESULTS: The position of the femoral tunnel was significantly high in group H than in group A (87.4% ± 4.2% versus 76.1% ± 3.7%, p

Matched MeSH terms: Femur/physiopathology