Performance of 5-Strand Hamstring Autograft Anterior Cruciate Ligament Reconstruction in the STABILITY Study: A Subgroup Analysis

BACKGROUND

Anterior cruciate ligament (ACL) reconstructions (ACLRs) with graft diameters <8mm have been shown to have higher revision rates. The 5-strand (5S) hamstring autograft configuration is a proposed option to increase graft diameter.

PURPOSE

To investigate the differences in clinical outcomes between 4-strand (4S) and 5S hamstring autografts for ACLR in patients who underwent ACLR alone or concomitantly with a lateral extra-articular tenodesis (LET) procedure.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Data from the STABILITY study were analyzed to compare a subgroup of patients undergoing ACLR alone or with a concomitant LET procedure (ACLR + LET) with a minimum graft diameter of 8mm that had either a 4S or 5S hamstring autograft configuration. The primary outcome was clinical failure, a composite of rotatory laxity and/or graft failure. The secondary outcome measures consisted of 2 patient-reported outcome scores (PROs)-namely, the ACL Quality of Life Questionnaire (ACL-QoL) and the International Knee Documentation Committee (IKDC) score at 24 months postoperatively.

RESULTS

Of the 618 patients randomized in the STABILITY study, 399 (228 male; 57%) fit the inclusion criteria for this study. Of these, 191 and 208 patients underwent 4S and 5S configurations of hamstring ACLR, respectively, with a minimum graft diameter of 8mm. Both groups had similar characteristics other than differences in anthropometric factors-namely, sex, height, and weight, and Beighton scores. The primary outcomes revealed no difference between the 2 groups in rotatory stability (odds ratio [OR], 1.19; 95% CI, 0.77-1.84; P = .42) or graft failure (OR, 1.13; 95% CI, 0.51-2.50; P = .76). There was no significant difference between the groups in Lachman (P = .46) and pivot-shift (P = .53) test results at 24 months postoperatively. The secondary outcomes revealed no differences in the ACL-QoL (P = .67) and IKDC (P = .83) scores between the 2 subgroups.

CONCLUSION

At the 24-month follow-up, there were no significant differences in clinical failure rates and PROs in an analysis of patients with 4S and 5S hamstring autografts of ≥8mm diameter for ACLR or ACLR + LET. The 5S hamstring graft configuration is a viable option to produce larger-diameter ACL grafts.

Predictors of Graft Failure in Young Active Patients Undergoing Hamstring Autograft Anterior Cruciate Ligament Reconstruction With or Without a Lateral Extra-articular Tenodesis: The Stability Experience

BACKGROUND

Anterior cruciate ligament (ACL) reconstruction (ACLR) has higher failure rates in young active patients returning to sports as compared with older, less active individuals. Augmentation of ACLR with an anterolateral procedure has been shown to reduce failure rates; however, indications for this procedure have yet to be clearly defined.

PURPOSE/HYPOTHESIS

The purpose of this study was to identify predictors of ACL graft failure in high-risk patients and determine key indications for when hamstring ACLR should be augmented by a lateral extra-articular tenodesis (LET). We hypothesized that different preoperative characteristics and surgical variables may be associated with graft failure characterized by asymmetric pivot shift and graft rupture.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Data were obtained from the Stability 1 Study, a multicenter randomized controlled trial of young active patients undergoing autologous hamstring ACLR with or without a LET. We performed 2 multivariable logistic regression analyses, with asymmetric pivot shift and graft rupture as the dependent variables. The following were included as predictors: LET, age, sex, graft diameter, tear chronicity, preoperative high-grade knee laxity, preoperative hyperextension on the contralateral side, medial meniscal repair/excision, lateral meniscal repair/excision, posterior tibial slope angle, and return-to-sports exposure time and level.

RESULTS

Of the 618 patients in the Stability 1 Study, 568 with a mean age of 18.8 years (292 female; 51.4%) were included in this analysis. Asymmetric pivot shift occurred in 152 (26.8%) and graft rupture in 43 (7.6%). The addition of a LET (odds ratio [OR], 0.56; 95% CI, 0.37-0.83) and increased graft diameter (OR, 0.62; 95% CI, 0.44-0.87) were significantly associated with lower odds of asymmetric pivot shift. The addition of a LET (OR, 0.40; 95% CI, 0.18-0.91) and older age (OR, 0.83; 95% CI, 0.72-0.96) significantly reduced the odds of graft rupture, while greater tibial slope (OR, 1.15; 95% CI, 1.01-1.32), preoperative high-grade knee laxity (OR, 3.27; 95% CI, 1.45-7.41), and greater exposure time to sport (ie, earlier return to sport) (OR, 1.18; 95% CI, 1.08-1.29) were significantly associated with greater odds of rupture.

CONCLUSION

The addition of a LET and larger graft diameter were significantly associated with reduced odds of asymmetric pivot shift. Adding a LET was protective of graft rupture, while younger age, greater posterior tibial slope, high-grade knee laxity, and earlier return to sport were associated with increased odds of graft rupture. Orthopaedic surgeons should consider supplementing hamstring autograft ACLR with a LET in young active patients with morphological characteristics that make them at high risk of reinjury.

Lattice Boltzmann simulations of droplet dynamics in time-dependent flows

We study the deformation and dynamics of droplets in time-dependent flows using 3D numerical simulations of two immiscible fluids based on the lattice Boltzmann model (LBM). Analytical models are available in the literature, which assume the droplet shape to be an ellipsoid at all times (P.L. Maffettone, M. Minale, J. Non-Newton. Fluid Mech 78, 227 (1998); M. Minale, Rheol. Acta 47, 667 (2008)). Beyond the practical importance of using a mesoscale simulation to assess "ab initio" the robustness and limitations of such theoretical models, our simulations are also key to discuss --in controlled situations-- some relevant phenomenology related to the interplay between the flow time scales and the droplet time scales regarding the "transparency" transition for high enough shear frequencies for an external oscillating flow. This work may be regarded as a step forward to discuss extensions towards a novel DNS approach, describing the mesoscale physics of small droplets subjected to a generic hydrodynamical strain field, possibly mimicking the effect of a realistic turbulent flow on dilute droplet suspensions.

[The experience of managing the risk due to the manual lifting of patients in the hospital reality of Local Health Screening Unit Enterprise 18, the Veneto region]

The possibility of accidents and diseases connected with manual handling of patients can be considered as one of the major risks in hospital environments for nursing, non-nursing and technical staff. Health surveillance of exposed workers has revealed numerous cases of back disorders with consequent temporary or permanent limitations of working activity. This involves not only heavy costs for the hospital but also a reduction in the quality of the assistance due to the difficulty in replacing or increasing staff. For these reasons the hospitals of the Local Health and Social Services Unit 18 of the Regione Veneto drew up a plan of interventions in order to address this problem and reduce exposure to manual handling of patients. Details of the costs borne by the hospital due to this risk factor are reported; after the implementation of the improvement plan (health surveillance, introduction of aids, training of staff) it is shown how a reduction in costs was achieved, thus demonstrating the efficacy of the measures taken (reduction of 39.2% in days of staff absence due to back disorders).

[Myringoplasty in children: a comparison with an adult population]

The indications for myringoplasty in children has always been a controversial subject since many authors feel the high frequency of the phlogistic auricular processes in children constitute an unfavorable prognostic factor to success of the procedure. The authors present the results obtained in 23 patients under 17 years of age who had undergone myringoplasty for simple perforation of the tympanum. In cases of posterior and inferior perforations, surgery was performed using the underlay technique and a transmeatal approach; in all other cases the overlay technique was used with a retroauricular approach. An average 30 month follow-up (range 12-55 months) revealed new perforations in only 2 cases (9%). From the functional point of view the average air/bone conduction gap was reduced to 10 dB. As a control, the results were compared to those obtained in 150 patients over 16 years of age, again affected by simple perforation of the tympanic membrane and treated by myringoplasty using the same methods. In the adults, 22 new perforations were found (15%) while the functional results were analogous to those obtained in the children group. In this light, it can be asserted that myringoplasty can be considered a safe procedure to be used in children and it does not appear essential to wait until they have finished growing before performing this procedure.

[Evaluation of the cochlear aqueduct patency: comparison of 2 noninvasive techniques]

Variations in cephalo-rachidian fluid pressure can be transmitted to the middle ear through the cochlear aqueduct (CA). This gives us a non-invasive manner to evaluate any changes in fluid pressure by measuring middle ear impedance (impedancemetry). The present study compared two indirect methods for measuring intracranial pressure: a) impedancemetry during evoked jugulo-tympanic reflex (JTR) and b) study of the tympanic membrane (TM) fine motility using a MMS-10 analyzer. The latter is a new procedure involving the indirect evaluation of the fluid pressure. In fact, when the CA is open the labyrinthine fluid pressure is transmitted to the oval window, the stapes platina and, finally, to the tympanic membrane where it can be measured with an MMS-10 unit. This equipment can measure nanoliter shifts in the TM. In particular, comparison between the clinostatic and orthostatic tympanic motility measurements enable one to establish whether the CA is patent or not. In the present study 15 subjects were examined using both a) impedancemetry during jugular compression and b) analysis of the TM shift using an MMS-10 unit. In 14 of the 15 cases there was good correlation between the data obtained using both methods: in all but one case it proved possible to record a JTR-induced variation in impedance whenever the MMS-10 indicated that the CA was open. The results suggest that, in clinical practice, the two methods can be used in parallel for non-invasive monitoring of variations in intracranial pressure in patients with neurological involvement. On the other hand, in the E.N.T. field these techniques could be used to study inner ear pathologies causing dynamic alterations of the endolabyrinth fluids (endolymphatic hydrops, labyrinthine fistula).

Training physicians to conduct physical activity counseling

BACKGROUND

In accordance with the U.S. Preventive Services Task Force recommendations, the current pilot study tests the feasibility and efficacy of a physician-delivered physical activity counseling intervention.

METHODS

A sequential comparison group design was used to examine change in self-reported physical activity between experimental (counseling and self-help materials) and control (usual care) patients at base-line and 6 weeks after the initial office visit. Patients in both groups were contacted by telephone 2 weeks after their office visit and asked about the physical activity counseling at their most recent physician visit. Experimental patients also received a follow-up appointment to discuss physical activity with their physician 4 weeks after their initial visit.

RESULTS

Counseling was feasible for physicians to do and produced short-term increases in physical activity levels. Both groups increased their physical activity, but the increase in physical activity was greater for patients who reported receiving a greater number of counseling messages.

CONCLUSIONS

Physician-delivered physical activity interventions may be an effective way to achieve wide-spread improvements in the physical activity of middle-aged and older adults.

Prognostic factors for head and neck tumor recurrence

The introduction of new treatment methods has stimulated the identification of further prognostic factors capable of defining the clinical and biological characteristics of the tumor type in question and improving treatment programming. The aim of this study was to identify which characteristics of the host and tumor are of prognostic value in relation to the onset of locoregional tumor recurrence. A total of 396 patients were studied. The tumor site distribution can be summarized as follows: 267 laryngohypopharyngeal, 74 oropharyngeal, 55 oral cavity. Variables regarding patient, tumor and histology were evaluated for the purpose of analysis. Multivariate analysis of these prognostic factors was performed using PLR software by BMDP. Mean tumor recurrence time was 19 months. Seventeen of the 29 variables analysed did not influence the probability of tumor recurrence. Two variables reduced the risk of tumor recurrence: age > 61 years and abundant and prevalently lymphocytic intra-and peritumoral infiltrate. The study of tumor recurrence onset mechanisms is justified by its impact on the evolution of disease. The use of multivariate analysis in this study showed that some clinical and pathological characteristics of squamous cell carcinoma of the head and neck have a statistically significant impact on tumor recurrence.

[Behavior of 8000 Hz audiometric threshold in chronic acoustic trauma]

The paper analyzes the 8 KHz threshold in subjects with noise-induced hearing loss. The study group consisted of 315 subjects occupationally exposed to noise and suffering from acoustic trauma, which was considered as a mean threshold of more than 25 dB at 2, 3 and 4 KHz. The mean shape of audiograms was characterized by a neurosensory deficit which was more elevated at 4 and 6 KHz whereas the threshold at 8 KHz was better. However, this pattern was found in 60% of the cases whereas in the remaining 40% the threshold at 8 KHz was worse. Subjects with the most impaired audiometric threshold at 8 KHz were mainly older, although cases were found in a low percentage of younger subjects. The results demonstrate that in individual cases it is impossible, on the basis of the shape of the audiogram, to establish whether a hearing loss is due to noise or age.

Disposition of exogenous tritium-labelled GM1lactone in the rat

The disposition of labelled [3H]GM1lactone, the inner ester of ganglioside GM1, was studied in the rat. After i.v. administration [3H]GM1lactone was quickly converted to its corresponding open form most likely by plasma esterases, and then displayed a pharmacokinetic profile identical to [3H]GM1. Following intramuscular administration of [3H]GM1lactone [3H]GM1 levels in plasma and in tissues were higher than those obtained after the administration of an equivalent dose of [3H]GM1. This increased bioavailability means that GM1lactone can be considered as a potential prodrug of GM1.

Pedigree analysis of sucrose intolerance among Native Alaskans

Sucrose intolerance, the inability to digest sugar, has been found to be unusually frequent among North Alaskan Inupiat. It is conjectured that this rare hereditary condition reached elevated levels due in part to the small, rather isolated population structure characterizing traditional Inupiat settlement patterns. An additional factor was likely to be a form of "selection relaxation" in which sucrose intolerance was not selected against during precontact times when the Inupiat diet consisted primarily of animal foods. An attempt was made to trace genealogical connections between pedigree containing cases of sucrose intolerance. This proved to be mostly unsuccessful due to insufficient information. It calls for researchers to make exerted efforts to obtain pertinent family history data along with extended pedigree records. Sucrose intolerance, while affecting relatively few persons, can lead to health problems, particularly if there is limited dietary choice. This is likely to be the situation among North Alaskan populations where sugar has become a major constituent in their acculturated diet.

Effects of phosphatidylserine administration of aged-related structural changes in the rat hippocampus and septal complex

Dendritic spine density of CA1 pyramidal neurons in the hippocampus and morphometric characteristics of the cholinergic neuronal population of the septal complex, were evaluated in young (four months), aged (27 months), and age-matched rats which had received long-term phosphatidylserine (BC-PS) administration (50 mg/kg/die, suspended in the drinking water). In aged rats, spine density decreased significantly by 12.11% in the basal dendrites and by 10.64% in the apical ones, as compared with young controls. In the cholinergic neuronal population of medial septum and diagonal band, aging induced a statistically significant reduction in cell number (-19.6%), in soma area (-18.5%), in cell maximal diameter (-9.2%), and in the area covered by all cholinergic profiles (-33%). By contrast, no significant reductions in the above-mentioned structural parameters were observed in aged BC-PS-treated rats when compared with young animals. The mechanisms underlying the beneficial effects of BC-PS can possibly be ascribed to the pharmacological actions exerted by BC-PS on neuronal membranes, neurotransmission, and/or interaction with NGF.

Effects of nerve growth factor and GM1 ganglioside on the number and size of cholinergic neurons in rats with unilateral lesion of the nucleus basalis

Four groups of rats with a unilateral ibotenic acid lesion of the nucleus basalis were treated with saline, nerve growth factor (NGF) 10 micrograms administered intracerebroventricularly twice per week, sialoganglioside GM1 30 m/kg daily i.p. and NGF twice per week plus GM1 10 mg/kg i.p. daily, respectively, beginning immediately after lesioning. Twenty-one days later the rats treated with saline showed a marked impairment in negotiating a 'step through' passive avoidance conditioned response, a 32% decrease in the number of choline acetyltransferase (ChAT)-positive neurons in the lesioned nucleus basalis and a 12% decrease in their areas. The rats treated with NGF and NGF plus GM1 showed no difference from sham-operated rats. In the GM1-treated rats a 12% decrease only in the number of ChAT-positive neurons was detected while performance and neuronal areas were normal. These findings indicate that NGF and GM1 prevent the cholinergic deficit by protecting the cholinergic neurons of the nucleus basalis from ibotenic acid neurotoxicity.

Dendritic spine loss in hippocampus of aged rats. Effect of brain phosphatidylserine administration

Dendritic spine density of pyramidal cells in region CA1 of the hippocampus has been evaluated in young (3 months), old (27 months) and old phosphatidylserine (BC-PS)-treated rats. BC-PS (50 mg/kg, suspended in tap water) was administered daily, starting at the age of 3 months until 27 months. Spine density was analyzed on Golgi-stained pyramidal neurons by a computerized analysis system. In 27-month-old rats, spine density showed with respect to 3-month-old animals, a significant decrease in both basal and apical dendrites (p less than 0.01; one-way ANOVA), with a mean loss of 12.11% in the basal dendrites and of 10.64% in the apical ones. In 27-month-old rats treated with BC-PS, values of spine density were not statistically different when compared to those of 3-month-old animals. The mechanisms underlying the beneficial effect of BC-PS treatment on neuronal connectivity might be explained on the basis of its pharmacological actions on neuronal membranes [9], neurotransmission [43] and/or interaction with NGF [7].

Reparative processes in aged brain

Endogenous neurotrophic factors have been proposed to play an important role in degenerative diseases and aging. In aged rats, neurotrophic activity induced by partial lesion of nigro-striatal pathways seems to be lower compared to young rats when assayed in vitro on cultured mesencephalic dissociated neuronal cells. In parallel experiments, we could also observe an age-dependent delay in spontaneous recovery of striatal tyrosine hydroxylase activity after lesion. Both experimental evidences suggest a low-potential neuroplasticity in aged rats. Nevertheless, the aging brain seems to be responsive to pharmacological manipulation. Long-term phosphatidylserine treatment has been shown to maintain the integrity of neuronal structures altered by the aging process. Putative mechanisms of action underlying these effects are presented.

In vivo treatment with GM1 prevents the rapid decay of ATPase activities and mitochondrial damage in hippocampal slices

Slices from rat CA3 hippocampal area show a 30% decrement in ATPase activity after 35 min of 'in vitro' incubation. Such a drop is accompanied by an alteration of mitochondrial ultrastructure. However, if rats are treated daily with GM1 ganglioside (10 mg/kg during 3 days) both phenomena are fully prevented. These results would suggest a protective effect of gangliosides onto membrane structures under stress conditions.

Cholecystokinin-immunoreactive cells form symmetrical synaptic contacts with pyramidal and nonpyramidal neurons in the hippocampus

The ultrastructural features and synaptic relationships of cholecystokinin (CCK)-immunoreactive cells of rat and cat hippocampus were studied using the unlabeled antibody immunoperoxidase technique and correlated light and electron microscopy. CCK-positive perikarya of variable shape and size were distributed in all layers and were particularly concentrated in stratum pyramidale and radiatum: the CCK-immunoreactive neurons were nonpyramidal in shape and the three most common types had the morphological features of tufted, bipolar, and multipolar cells. Electron microscopic examination revealed that all the CCK-positive boutons established symmetrical (Gray's type II) synaptic contacts with perikarya and dendrites of pyramidal and nonpyramidal neurons. The origin of some of the boutons was established by tracing fine collaterals that arose from the main axon of two CCK-immunostained cells and terminated in the stratum pyramidale; these collaterals were then examined in the electron microscope. The axon of one such neuron exhibited a course parallel to the pyramidal layer and formed pericellular nets of synaptic boutons upon the perikarya of pyramidal neurons. This pattern of axonal arborization is very similar to that of some of the basket cells, previously suggested to be the anatomical correlate for pyramidal cell inhibition. Typical dendrites of pyramidal cells also received symmetrical synaptic contacts from CCK-immunoreactive boutons, and some of these boutons could be shown to originate from a local neuron in stratum radiatum. Many CCK-immunoreactive cells received CCK-labeled boutons upon their soma and dendritic shafts. Synaptic relationship, established by multiple "en passant" boutons, was observed between CCK-positive interneurons of the stratum lacunosum-moleculare and radiatum. The soma and dendrites of the CCK-immunostained neurons also received symmetrical and asymmetrical synapses from nonimmunoreactive boutons. These results indicate that the CCK-immunoreactive neurons participate in complex local synaptic interactions in the hippocampus.