The grading defines stenosis in different subjects than surface measurements alone. Since it mainly considers impingement of neural tissue it might be a more appropriate clinical and research tool as well as carrying a prognostic value.

No abstract

The real and imaginary parts, nand k, of the complex index of refraction of a hydrogenated amorphous carbon (a-C:H) film have been determined for photon energies between 1.45 and 4.9 e V from measurem~nts ~f reflectance R an~ tran~mittance T. Both nand k, and consequently E 1 and E2 (the real and 1magmary parts of the d1electnc constant), show a considerable variation with subsequent anonealing of the a-C:H fil.m up to Ta =. 750 OC, with the most rapid changes occurring for Ta = 450 C and above. The opt1cal gap E opt 1S observed to decrease from 2.2 eV to 0 as the film i~ anneal~d, signalin~ the. development of graphitic short range order in the film. Using an effect1ve medlUm approx1mation to model the optical properties of the film, we find that the asdeposi~ed film contains amo~phous diamond-like, graphitic, and polymeric components. With annea~l?g, the amorphous d1amond-like and polymeric components decrease, the amorphous graph1tiC component grows, and a void component appears. We discuss the local order present in the as-deposited and annealed film.

The reactions of oxygen false(O2false) with the clean Si(111) and (100) surfaces have been studied at high temperatures (890°–1150°C) for oxygen pressures between 5×10−5 normaland 5×10−2 normalTorr . The critical conditions involving oxygen pressure and substrate temperature which are necessary for the growth of SiO2 to occur on these Si surfaces have been determined, and are found to be independent of substrate orientation and doping type under the conditions studied. The observed critical conditions for growth are consistent with a theoretical model which focuses on the kinetics of SiO2 cluster growth and on the thermodynamics of the competing etching reaction leading to production of normalSiO . Evidence is presented for epitaxial growth on Si(100) of cubic SiO2 , β‐cristobalite.

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Objectives: To examine (a) return to competitive sport within 12 months of anterior cruciate ligament (ACL) reconstruction, (b) maintenance of competitive participation at follow up, and (c) the relation of the level of sports activity and competitive participation at follow up to subjective functional assessments. Also to address the incidence of continued competitive participation despite notable functional problems with the operated knee at 12 months and follow up. Methods: All patients were competitive athletes before injury and had undergone ACL reconstruction by the transtibial endoscopic technique with either a bone-patellar tendon-bone or a multiple looped hamstring autograft. Evaluation was carried out a mean of 43 months (range 24-73) after surgery by a postal questionnaire in which the Cincinnati sports activity scale (CSAS) and Cincinnati sports function scales were presented in conjunction with closed questions on change in competitive level and the presence of complaints. Results: Of 109 selected patients, 77 (71%) responded. At follow up, 62 of 77 patients (81%) reported that they had returned to competition within 12 months of surgery. Within the same time frame, 55 of the above 62 patients (89%) also claimed to have returned to the level at which they were competing before injury (or higher). At follow up, 30 of the above 55 patients (54%) reported to still be competing at this high level. Twelve of the above 55 patients (22%) also admitted to major problems with the operated knee at that time. The overall incidence of patients competing despite major functional impairment in the operated knee was 13 of 62 (21%) at 12 months and six of 47 (13%) at follow up. Thirty eight patients (49%) were active in sport at least four times a week at follow up (CSAS level 1), and, using Spearman's rank correlation between CSAS scores and total sports function scores, r was calculated to be 0.44. Competitive and male patients had higher total sports function scores at follow up than non-competitive (p = 0.005) and female (p = 0.02) patients respectively. Conclusions: The reported return to competition at the previous level, both within 12 months and at follow up, was high but as expected considering the standard of treatment, patient selection, and study exclusion criteria. Patients with few functional complaints maintained a high level of sporting activity, even after discontinuing competitive participation.A fter the clinical diagnosis of an anterior cruciate ligament (ACL) rupture in a competitive athlete, reconstructive surgery is indicated primarily by the patient's motivation to return to (a) competition at the previous level or (b) an athletic lifestyle involving functionally challenging activities that were previously impossible because of the ACL deficiency.

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The shape of the lumbar spine in the sagittal plane varies between individuals and as a result of postural changes but it is not known how the shape in different postures is related. Sagittal images of the lumbar spines of 24 male volunteers were acquired using a positional magnetic resonance scanner. The subjects were imaged lying supine, standing and sitting. An active shape model was used to characterize shape in terms of independent modes of variation. Two modes were identified that described the total (mode 1) and distribution (mode 2) of the curvature. The spinal shape was found to be intercorrelated between the three postures for both modes, suggesting that the lumbar spine has an element of shape that is partially maintained despite postural alterations. Mode 1 values indicated that the spine was straightest when standing and curviest when sitting. Mode 2 values indicated that the distribution in the curvature was most even when sitting and least even when lying supine. Systematic differences in the behaviour of the spine, when changing posture, were found that suggest that the shape of the spine may affect its biomechanics.