A non-invasive biomechanical device to quantify knee rotational laxity: Verification of the device in human cadaveric specimens.

BACKGROUND: Biomechanical measurement tools have been developed and widely used to precisely quantify knee anterior-posterior laxity after anterior cruciate ligament (ACL) injury. However, validated objective device to document knee rotational laxity, though being developed by different researchers, are not yet widely used in the daily clinical practice. A new biomechanical device was developed to quantify knee internal and external rotations. METHODS: The reliability of the new biomechanical device which measures knee rotations were tested. Different torques (1-10Nm) were applied by the device to internally and externally rotate human cadaveric knees, which were held in a flexion angle of 30°. The rotations were measured by the device in degrees. There were two independent testers, and each tester carried out three trials. Intra-rater and inter-rater reliability were quantified in terms of intraclass correlation (ICC) coefficient among trials and between testers. The device was verified by the comparison with a computer assisted navigation system. ICC was measured. Mean, standard deviation and 95% confident interval of the difference as well as the root mean square difference were calculated. The correlations were deemed to be reliable if the ICC was above 0.75. RESULTS: The intra-rater and inter-rater reliability achieved high correlation for both internal and external rotation, ranged from 0.959 to 0.992. ICC between the proposed meter and the navigation system for both internal and external rotation was 0.78. The mean differences were 2.3° and 2.5° for internal and external rotation respectively. CONCLUSIONS: A new knee rotational laxity meter was proposed in this study. Its reliability was verified by showing high correlation among trials. It also showed good correlation to a gold standard of measurement. It might be used to document knee rotational laxity for various purposes, especially after ACL injury, after further validation of the device in human subjects.

Evaluation of combined prescription of rocker sole shoes and custom-made foot orthoses for the treatment of plantar fasciitis.

BACKGROUND: It is a routine practice to prescribe a combination of rocker shoes and custom-made foot orthoses for patients with plantar fasciitis. Recently, there has been a debate on this practice, and studies have shown that the individual prescription of rocker shoes or custom-made foot orthoses is effective in treating plantar fasciitis. The aim of this study was to evaluate and compare the immediate therapeutic effects of individually prescribed rocker sole shoes and custom-made foot orthoses, and a combined prescription of them on plantar fasciitis. METHODS: This was a cross-over study. Fifteen patients with unilateral plantar fasciitis were recruited; they were from both genders and aged between 40 and 65. Subjects performed walking trials which consisted of one 'unshod' condition and four 'shod' conditions while wearing baseline shoes, rocker shoes, baseline shoes with foot orthotics, and rocker shoes with foot orthotics. The study outcome measures were the immediate heel pain intensity levels as reflected by visual analog scale pain ratings and the corresponding dynamic plantar pressure redistribution patterns as evaluated by a pressure insole system. RESULTS: The results showed that a combination of rocker shoes and foot orthoses produced a significantly lower visual analog scale pain score (9.7 mm) than rocker shoes (30.9 mm) and foot orthoses (29.5 mm). With regard to baseline shoes, it also significantly reduced the greatest amount of medial heel peak pressure (-33.58%) without overloading other plantar regions when compared to rocker shoes (-7.99%) and foot orthoses (-28.82%). DISCUSSION: The findings indicate that a combined prescription of rocker sole shoes and custom-made foot orthoses had greater immediate therapeutic effects compared to when each treatment had been individually prescribed.

A randomized controlled trial comparing bone mineral density changes of three different ACL reconstruction techniques.

INTRODUCTION: This study aimed to compare the changes in bone mineral density (BMD) of three different ACL reconstruction (ACLR) techniques and its association with early clinical and functional outcomes. METHODS: Sixty-two male adult patients undergoing primary ACLR were prospectively parallel randomized to bone-patellar tendon-bone graft (BPTB), single-bundle (HT-SB) or double-bundle (HT-DB) hamstring graft. BMD (primary outcome) at the proximal tibia, distal femur, femoral neck and trochanteric region was measured blindly at day 1, 3 months, 5 months and 1 year after surgery. KT-1000, Lysholm, IKDC, one-leg hop test and Lachman test were performed blindly at baseline and 1 year post-reconstruction. RESULTS: There was a significant bone loss at the injured knee and hip at 3 and 5 months which was reversible at the knee, but not at the hip, at 1 year post-operation. There was a significant improvement of early clinical and functional outcomes at 1 year. No significant differences in bone loss was detected among different surgical techniques, except BMD loss at the femoral neck, though a trend of greater BMD loss in the HT-SB group at 5 months after reconstruction was observed. There was a significant positive correlation between BMD at the distal femur and the single-leg hop distance at 1 year. CONCLUSION: In conclusion, the three surgical techniques were similar in transient bone loss at the knee region, irreversible bone loss at the hip, early clinical and functional outcomes up to 1 year post-reconstruction. BMD at the distal femur was positively associated with the single-leg hop distance at 1 year post-reconstruction.

An ankle joint model-based image-matching motion analysis technique.

This study presented a model-based image-matching (MBIM) motion analysis technique for ankle joint kinematic measurement. Five cadaveric below-hip specimens were manipulated through a full range of ankle joint motions in bare-foot and shoed conditions. The ankle motions were analyzed by bone-pin marker-based motion analysis and MBIM motion analysis techniques respectively. The root mean square errors of all angles of motion were less than 3°. The average Intraclass Correlation Coefficients (ICCs) for the intra-rater reliability were greater than 0.928 and the average ICCs for the inter-rater reliability were greater than 0.948 for all angles of motion. Excellent validity, intra-rater reliability and inter-rater reliability were achieved for the MBIM technique in both bare-foot and shoed conditions. The MBIM technique can therefore provide good estimates of ankle joint kinematics.