Functional lengths of the lower limb arterial tree measured by CT angiography centreline analysis: implications for catheter lengths in peripheral angioplasty.

PURPOSE: Lower limb angioplasty is a common procedure. However, arterial lengths have not been well studied and there is no evidence base for the optimum catheter lengths required for the various applications of femoral or distal below-the-knee angioplasty. The industry standard catheter measures 80 cm. METHOD: Fifty CT angiograms were post-processed using vessel tracking and centreline analysis tools and lengths were measured from the ipsilateral first segment of the femoral artery (FSFA) (common femoral artery) to the contralateral FSFA and on to the second segment of the femoral artery (superficial femoral artery) and popliteal arteries down to the posterior tibial (PT) artery at the ankle. This allowed clinically meaningful lengths for 'cross-over' and 'antegrade' angioplasty to be calculated. RESULTS: Mean cross-over length to the second segment of the femoral artery as it crossed the femoral cortex was 72.3 cm, and the mean cross-over length to the popliteal artery at the knee joint was 83.8 cm, and the length from the FSFA to the PT was 85.1 cm. CONCLUSION: Selection of a standard length catheter can result in a situation where the catheter is too short. Optimum catheter length for a particular task will reduce the need for catheter exchanges and use of multiple balloons and therefore reduce complications, procedure time, radiation dose and cost.

Cementless surface replacement arthroplasty of the shoulder for osteoarthritis: results of fifty Mark III Copeland prosthesis from an independent center with four-year mean follow-up.

PURPOSE: Few studies have reported the outcome of cementless surface replacement (CSRA). We initiated this study to analyze results of the Mark III Copeland prosthesis used as a hemiarthroplasty in patients with glenohumeral osteoarthritis. MATERIALS AND METHODS: We retrospectively reviewed 53 consecutive Mark III Copeland CRSA hemiarthroplasties in 46 patients (30 women, 16 men) with glenohumeral osteoarthritis from an independent institution by a single surgeon. Patients were a mean age of 69 years (range, 45-94 years). Mean follow-up was 4.2 years (range, 2-8 years). Fifty uncemented hemiarthroplasties were available for review. RESULTS: Mean (range) age-adjusted Constant and Oxford scores improved from 38.5 (15-61) and 22 (9-31) to 75.1 (38-87) and 42 (18-48), respectively. Anterosuperior escape of the humeral head developed in 1 patient who had an oversized humeral component due to progressive rotator cuff failure at 2 years. Moderate glenoid erosion was present in 12% and correlated with oversizing of the humeral component. There was one revision to a stemmed cemented hemiarthroplasty for periprosthetic fracture. No patients have required revision for aseptic loosening, rotator cuff failure, or glenoid erosion to date. CONCLUSIONS: Copeland surface replacement hemiarthroplasty for glenohumeral osteoarthritis can provide functional results similar to modular stemmed prostheses, with a relatively low revision rate at 4.2 years of follow-up; however, there is high rate of glenoid erosion that may complicate future revision surgery, and we did not achieve the same functional improvement as that achieved from the designer's institution.

Acute effects of a vibration-like stimulus during knee extension exercise.

PURPOSE: This study was conducted to test whether a low-frequency vibration-like stimulus (rapid variable resistance) applied during a single session of knee extension exercise would alter muscle performance. METHODS: Torque, knee joint angle, EMG activity of rectus femoris (RF) and vastus lateralis (VL) muscles, and VL muscle oxygenation status (near-infrared spectroscopy) were recorded during metronome-guided knee extension exercise. Nine healthy adults completed four trials exercising at contraction intensities of 35% (L) or 70% (H) of one-repetition maximum (1RM) in control (no vibration, Vb-) or vibrated condition (superimposed 10-Hz vibration-like stimulus, Vb+). Maximum voluntary contraction and 1RM were tested pre- and postexercise. RESULTS: During 1RM tests, muscle dynamic strength (P=0.02) and power (P=0.05) were significantly higher during vibrated rather than nonvibrated trials, and strength was significantly higher post- than preexercise (P=0.002), except during LVb- trial. Median spectral frequency of VL and RF EMG activity was significantly higher during postexercise than preexercise 1RM test in the vibration trials but unchanged in the control trials (P<0.02). The rate of muscle deoxygenation was 58% faster during H than L exercise (P=0.001), and vibration superimposition tended to speed muscle deoxygenation rate (P=0.065, 36% effect size) particularly during L trials. CONCLUSION: Vibration superimposition during knee extension exercise at low contraction intensity enhanced muscle performance. This effect appears to result from adaptation of neural factors such as motor unit excitability (recruitment and firing frequency, conduction velocity of excitation) in response to sensory receptor stimulation. Muscle vibration may increase the training effects derived from light-to-moderate exercise.