Rossall Hospital

ObjectivesAnterior cruciate ligament (ACL) repair for proximal tears, where the ligament is re-attached and augmented with suture tape, can negate the need for graft harvest, thereby maintaining native anatomy. Autograft harvest has been associated with persistent deficits in lower limb muscle strength after recovery from ACL reconstruction. The aim of this study is to compare lower limb muscle strength following ACL repair and reconstruction. MethodsNineteen ACL repair patients augmented with suture tape and nineteen ipsilateral semitendinosus-gracilis autograft ACL reconstruction patients (both mean 4 years postoperatively) were recruited, along with twenty healthy volunteers. Patient-reported outcome measures (PROMs) were obtained using the Knee Injury and Osteoarthritis Outcome Score (KOOS), Lysholm, and Tegner scores. Maximal isometric quadriceps and hamstring strength at 90° knee flexion were measured using a fixed Myometer after a warm-up and three maximal-effort contractions. ResultsMean hamstring strength of the reconstructed legs was lower than that of healthy volunteers by 0.29 Nm/kg. The hamstring strength ratio of the operated side to the uninjured side was greater in the repair (95% ​± ​13) than in the reconstruction (81% ​± ​18) group. There were no statistically significant differences between sides for quadriceps peak torque or for hamstrings in the volunteer or repair group. PROMs scores for the reconstruction group were significantly lower than volunteers across all domains and lower than repair for KOOS activities of daily living and Lysholm scores. ConclusionHamstring weakness seen following ACL reconstruction is not evident following ACL repair with suture tape augmentation. Strength asymmetry could contribute to re-injury risk and influence functional performance, while altered loads affect knee biomechanics and may lead to osteoarthritis progression. The absence of these deficits in the repair group demonstrates a potential benefit of this technique when used in appropriate patients. Level of evidenceII.

SummaryDuring spring and autumn 1970 and 1971 the movements of terns off the coast of Ghana near Accra were studied by radar. In autumn, dense movements were recorded within 22 km of the coast both day and night from July to early December. Fluctuations in the magnitude of the movements suggest that the terns were on passage through the Gulf of Guinea. Simultaneous to these movements were roosting flights into shore roosts and both movements appeared independent.In contrast, no spring movements along the coastline were detected either by radar or visually from the land. Although small tern flocks probably moved westwards within 22 km of the coast, but outside their detectable radar range, the results suggest that the majority of terns return through the Gulf of Guinea by a different route from that taken in autumn.The difference between spring and autumn movements correlates well with the seasonal variation of the terns' food sources. In autumn, upwellings result in an abundant fish supply (sardines) in the surface waters close to land, whereas in spring, fish is abundant only well off shore such as at fronts (convergences) and upwellings (divergences) both of which have been located as far as 600 km from the coast.

(1949). A biographical note on William Brownrigg, M.D., F.R.S. (1711–1800) Annals of Science: Vol. 6, No. 2, pp. 186-196.

An abstract is not available for this content so a preview has been provided. Please use the Get access link above for information on how to access this content.