Lateral drill holes decrease strength of the femur: An observational study using finite element and experimental analyses

Background: Internal fixation of femoral fractures requires drilling holes through the cortical bone of the shaft of the femur. Intramedullary suction reduces the fat emboli produced by reaming and nailing femoral fractures but requires four suction port

Sagittal plane articulation of the contralateral knee of subjects with posterior cruciate ligament deficiency: an observational study

<p>Abstract</p> <p>Background</p> <p>The aim of the present study was to compare the in vivo articulation of the healthy knee to the contralateral knee of subjects with acute and chronic PCL injuries.</p> <p>Methods</p> <p>Magnetic resonance was used to generate sagittal images of 10 healthy knees and 10 knees with isolated PCL injuries (5 acute and 5 chronic). The subjects performed a supine leg press against a 150 N load. Images were generated at 15 degree intervals as the knee flexed from 0 to 90 degrees. The tibiofemoral contact (TFC), and the centre of the femoral condyle (as defined by the flexion facet centre (FFC)), were measured from the posterior tibial cortex.</p> <p>Results</p> <p>There was no significant difference in the TFC and FFC between the healthy knee and contralateral knee of subjects with acute and chronic PCL injuries in the medial and lateral compartments of the knee.</p> <p>Conclusions</p> <p>The findings of this study suggest there is no predisposing articulation abnormality to PCL injury, in the setting of chronic injury the contralateral knee does not modify its articulation profile and the contralateral knee can be used as a valid control when evaluating the articulation of the PCL deficient knee.</p

Vertical stiffness and muscle strain in professional Australian football

Abstract: The purpose of this study was to establish if vertical stiffness was greater in professional Australian rules footballers who sustained a lower limb skeletal muscle strain compared to those who did not, and to establish if a relationship between age, or training history, and vertical stiffness existed. Thirty-one participants underwent weekly rebound jump testing on a force platform over two seasons. Vertical stiffness was calculated for injured players and the uninjured cohort 1 and 3 weeks prior to sustaining an injury and at the end of preseason. Eighteen athletes were in the “uninjured” cohort and 13 in the “injured” cohort. No significant difference in vertical stiffness was observed between groups (P = 0.18 for absolute stiffness; P = 0.08 for stiffness relative to body mass), within groups (P = 0.83 and P = 0.88, respectively) or for a time*cohort interaction (P = 0.77 and P = 0.80, respectively). No relationship between age and vertical stiffness existed (r = −0.06 for absolute and relative stiffness), or training history and vertical stiffness (r = −0.01 and 0.00 for absolute and relative stiffness, respectively) existed. These results and others lend to suggest that vertical stiffness is not related to lower limb muscle strain injury

A review of models of vertical, leg, and knee stiffness in adults for running, jumping or hopping tasks.

The 'stiffness' concept originates from Hooke's law which states that the force required to deform an object is related to a spring constant and the distance that object is deformed. Research into stiffness in the human body is undergoing unprecedented popularity; possibly because stiffness has been associated with sporting performance and some lower limb injuries. However, some inconsistencies surrounding stiffness measurement exists bringing into question the integrity of some research related to stiffness. The aim of this study was to review literature which describes how vertical, leg and knee stiffness has been measured in adult populations while running, jumping or hopping. A search of the entire MEDLINE, PubMed and SPORTDiscus databases and an iterative reference check was performed. Sixty-seven articles were retrieved; 21 measured vertical stiffness, 51 measured leg stiffness, and 22 measured knee stiffness. Thus, some studies measured several 'types' of stiffness. Vertical stiffness was typically the quotient of ground reaction force and centre of mass displacement. For leg stiffness it was and change in leg length, and for the knee it was the quotient of knee joint moments and change in joint angle. Sample size issues and measurement techniques were identified as limitations to current research

Physiotherapist-directed rehabilitation exercises in the outpatient or home setting improve strength, gait speed and cadence after elective total hip replacement: a systematic review

Question: In people who have been discharged from hospital after a total hip replacement, do rehabilitation exercises directed by a physiotherapist improve strength, gait, function and quality of life? Are these exercises as effective in an unsupervised home-based setting as they are in a supervised outpatient setting? Design: Systematic review with meta-analysis of randomised trials. Participants: Adult patients after elective total hip replacement. Intervention: Physiotherapist-directed rehabilitation exercises after discharge from hospital following total hip replacement. Outcome measures: Hip and knee strength, gait parameters, functional measures, and quality of life. Results: Five studies comprising 234 participants were included in the review. Sufficient data for meta-analysis were only obtained for hip and knee strength, gait speed and cadence. Physiotherapy rehabilitation improved hip abductor strength by a mean of 16. Nm (95% CI 10 to 22), gait speed by 6 m/min (95% CI 1 to 11) and cadence by 20 steps/min (95% CI 8 to 32). Favourable but non-significant improvements in strength were noted for other muscle groups at the hip and knee. Function and quality of life could not be meta-analysed due to insufficient data and heterogeneity of measures, but functional measures tended to favour the physiotherapy rehabilitation group. Most outcomes were similar between outpatient and home-based exercise programs. Conclusion: Physiotherapy rehabilitation improves hip abductor strength, gait speed and cadence in people who have been discharged from hospital after total hip replacement. Physiotherapist-directed rehabilitation exercises appear to be similarly effective whether they are performed unsupervised at home or supervised by a physiotherapist in an outpatient setting

Supervised or Unsupervised Rehabilitation After Total Hip Replacement Provides Similar Improvements for Patients: A Randomized Controlled Trial

Objective: To determine whether patients do better with unsupervised (home-based) physiotherapy or in an outpatient setting. Setting: Acute care public hospital in the region, supporting a population of ∼540,000. Design: Single-blind randomized controlled trial. Participants: Adult patients (N=98) after unilateral elective total hip replacement (THR) were randomly assigned to a supervised (center-based) exercise (n=56) or a unsupervised (home-based) exercise (n=42) program and followed for 6 months postsurgery. Interventions: The supervised group attended a 4-week outpatient rehabilitation program supervised by a physiotherapist. The unsupervised group was given written and pictorial instructions to perform rehabilitation independently at home. Main Outcome Measures: Western Ontario and McMaster Universities Osteoarthritis Index; Short-Form 36-item Health Questionnaire (SF-36) mental and physical component summary measures; University of California, Los Angeles activity scale; and timed Up and Go test. Results: There were no differences between the groups for any measure. The overall differences between the adjusted means were as follows: Western Ontario and McMaster Universities Osteoarthritis Index, 0.50 (95% confidence interval [CI], -6.8 to 5.7); SF-36 physical component summary, 0.8 (95% CI, -6.5 to 8.1); SF-36 mental component summary, 1.7 (95% CI, -4.1 to 7.4); University of California, Los Angeles activity scale, 0.3 (95% CI, 5.2 to 6.1); and timed Up and Go test, 0 seconds (95% CI, -1.4 to 1.3s). Conclusions: The results demonstrated that outcomes in response to rehabilitation after THR are clinically and statistically similar whether the program was supervised or not. The results suggest that early rehabilitation programs can be effectively delivered unsupervised in the home to low-risk patients discharged home after THR. However, the relative effect of late-stage rehabilitation was not teste

Muscle pre-activation strategies play a role in modulating Kvert for change of direction manoeuvres: An observational study

The aim of the study presented in this paper was to establish if a relationship existed between lower limb muscle pre-activation strategies and vertical stiffness (Kvert). Participants from a professional rugby union club all performed a multidirectiona