Comparing outcomes of medial parapatellar and subvastus approaches in total knee arthroplasty: a randomized controlled trial

The medial parapatellar (MP) approach in total knee arthroplasty is more common, but the subvastus (SV) approach is less insulting to the quadriceps. Whether the SV approach affords better outcomes was investigated using 90 participants with knee osteoarthritis, randomized to receive either SV or MP approaches and followed for 18 months. The primary outcome was the American Knee Society Score (AKSS); secondary outcomes included pain, knee range, quadriceps lag, Oxford Knee Score, 3-m timed "Up and Go" test, days to straight leg raise, surgeon perceived difficulty, operation duration, and length of stay. Analysis (n = 76) revealed no significant difference in AKSS (P = .076) or other outcomes, except the following: AKSS Functional scores at 12 and 18 months, favoring the MP (P = .032 and P = .028 respectively); surgeon's perceived difficulty, favoring the MP (P = .001); and days to straight leg raise, favoring the SV (P = .044). This study found that the SV approach offers no clinical benefit over the MP approach.     

Effects of ionizing radiation on the mechanical properties of human bone

Allogeneic bone grafts are frequently sterilized by means of ionizing radiation. We investigated the effects of ionizing radiation on both quasistatic and impact mechanical properties of human bone. Specimens from four paired femora of four donors received doses of 29.5 kGy (“Standard” frequently used by tissue bandks), 94.7 kGy (“high”) or 17 kGy (“low”) of ionizing radiation. Young's modulus was unchanged by any level of radiation. Radiation significantly reduced bending strength, work to fracture, and impact energy absorption; in each case, the severity of the effect increased from low to standard to high doses of radiation. Work to fracture was particularly severely degraded; specimens irradiated with the high dose absorbed only 5% of the energy of the controls. Radiation. even at relatively low doses, makes the bone more brittle and thereby reduces its energy-absorbing capacity. We suggest that because the level of radiation required to produce an acceptable level of viral inactivation (90 kGy) produces an unacceptable reduction in the mechanical integrity of the bone. low levels of radiation, sufficient to produce bacterial safety, should be used in conjunction with biological tests to ensure viral safety.     

The uptake of radio-active glucose in vivo and in vitro by the metacercaria of Diplostomum phoxini (Faust) and its conversion to glycogen

Summary The metacercaria of Diplostomum phoxini (Faust) in the brain of the minnow Phoxinus phoxinus (L.) takes up nutrients from the surrounding tissues. Suspension of metacercariae in 2 % ferritin showed that they are not capable of taking up particulate material into the epidermis. Histochemical tests and biochemical estimations showed the presence of glycogen in the metacercaria. Experiments utilizing autoradiography and liquid scintillation counting methods indicated that radio-active glucose is taken up by the epidermis and gastrodermis of the metacercaria in vivo and in vitro. Phosphatase activity may be associated with the absorption. Of the absorbed glucose 6.5 % per metacercaria was converted to glycogen in 3 h in vitro.     

Surface ultrastructure of the redia ofParorchis acanthus Nicoll (Digenea: Philophthalmidae)

Rediae ofParorchis acanthus were examined by scanning electron microscopy and the ultrastructure of the surface related to migration through the digestive gland ofNucella lapillus. The median ventral birth papilla, ventro-lateral processes, and posterior papilliform process, of young active rediae, apparently serve to anchor the body during migration. The honeycomb-like apex of the birth papilla and ventro-lateral processes may be a strengthening device. Uniciliate sensory receptors around the mouth, on the birth papilla, and posterior terminal papilla are probably touch receptors or chemoreceptors concerned with feeding and orientation during migration. After the formation of the birth pore, and with increase in size and in the number of contained cercariae, the redia becomes less active, loses its characteristic shape, and is eventually immobile.     

Recent advances in therapeutic exercise for the neck: implications for patients with head and neck pain

There have been recent advances in the rehabilitation of the muscles that control the head and neck. These advances are based on evidence of specific neck muscle dysfunction in individuals with persistent head and neck pain. Traditional rehabilitation strategies have focused predominantly on muscle strength and endurance under high loads. New evidence suggests that in people with neck pain there are underlying neuromuscular problems that may require more immediate attention and may not be adequately addressed by simple strength and high-load endurance retraining. Evidence of altered coordination between the deep and superficial neck muscles, greater neck muscle fatigue under sustained low loads, and deficits in kinaesthetic sense have been identified in symptomatic individuals. There is evidence to indicate that addressing these muscle control problems, with specific gentle exercise strategies, results in a reduction in neck pain and associated symptoms.     

Differential alkaline phosphatase responses of rat and human bone marrow derived mesenchymal stem cells to 45S5 bioactive glass

Bioactive glass is used as both a bone filler and as a coating on implants, and has been advocated as a potential osteogenic scaffold for tissue engineering. Rat-derived mesenchymal stem cells (MSCs) show elevated levels of alkaline phosphatase activity when grown on 45S5 bioactive glass as compared to standard tissue culture plastic. Similarly, exposure to the dissolution products of 45S5 elevates alkaline phosphatase activity and other osteogenic markers in these cells. We investigated whether human MSCs grown under the same laboratory conditions as rat MSCs would exhibit similar responses. In general, human MSCs produce markedly less alkaline phosphatase activity than rat MSCs, regardless of cell culture conditions, and do not respond to the growth factor BMP-2 in the same way as rat MSCs. In our experiments there was no difference in alkaline phosphatase activity between human MSCs grown on 45S5 bioactive glass or tissue culture plastic, in samples from five different orthopaedic patients, regardless of culture media composition. Neither was there any consistent effect of 45S5 dissolution products on human MSCs from three different donors. These results suggest that the positive effects of bioactive glass on bone growth in human patients are not mediated by accelerated differentiation of mesenchymal stem cells.     

Wireless orientation sensors: their suitability to measure head movement for neck pain assessment

The purpose of this study was to verify the performance and suitability of new generation 3D wireless orientations sensors to measure cervical range of movement against a criterion standard instrument, an electromagnetic motion analysis system (Fastrak-Polhemus). The wireless orientation sensor (InertiaCube 3) consists of 9 motion-sensing elements: 3 accelerometers, 3 angular velocity rate transducers and 3 magnetometers. Measurements of cervical range of motion in each primary plane, left-lateral flexion, flexion and left rotation were directly compared from both systems in 10 normal asymptomatic subjects. Results showed very high cross-correlations (.99–.97) and low average root mean square errors (0.7–2.5°). We conclude that orientation sensors are a valid, accurate and suitable device for obtaining cervical joint ranges of motion in the primary plane of movement.     

Cyclic pneumatic soft-tissue compression enhances recovery following fracture of the distal radius: a randomised controlled trial

QUESTIONS: Does the addition of cyclic pneumatic soft-tissue compression during the 6-week immobilisation period following fracture of the distal radius result in a faster recovery of muscle strength and joint range of motion? Does it result in a larger recovery of muscle strength and joint range of motion immediately after the immobilisation period (at 6 weeks) or four weeks after the immobilisation period (at 10 weeks)? DESIGN: Randomised controlled trial with concealed allocation and assessor blinding. PARTICIPANTS: 21 patients with fracture of the distal radius. INTERVENTION: The experimental group received cyclic pneumatic soft-tissue compression during the 6-week immobilisation period whereas the control group received usual care. Both groups were instructed to actively make a fist 100 times per day during the 6-week immobilisation period and were given an exercise program during the 4-week post-immobilisation period. OUTCOME MEASURES: Function was measured as power grip, pinch grip, key grip, and supination strength using dynamometry from Week 1 to 10 as well as wrist flexion/extension and forearm supination/pronation range of motion using goniometry from Week 6 to 10. The outcome measures are presented as a percentage of the intact side. RESULTS: The experimental group improved significantly faster than the control group in muscle strength from Week 1 to 10 (p ? 0.001) but not in joint range of motion from Week 6 to 10 (p > 0.05). By Week 6, the experimental group was 12-26% stronger and had 8-14% more range of motion than the control group. By Week 10, the experimental group was 24-29% stronger and had 10-15% more range of motion than the control group. CONCLUSION: The findings indicate that a larger clinical trial is warranted and should incorporate direct measures of fracture healing.