Single Portal Segmental Labral Reconstruction of the Hip.

Many techniques have been described for reconstruction of the acetabular labrum, but the procedure is known to be technically rigorous leading to lengthy procedure times and traction times. Increasing efficiency of the procedure with respect to graft preparation and delivery remain areas for potential improvement. We describe a simplified procedure for arthroscopic segmental labral reconstruction using peroneus longus allograft and a single working portal to shuttle the graft into the joint via suture anchors placed at the terminal extents of the graft defect. This method allows for efficient preparation, placement and fixation of the graft that can be completed in under 15 minutes.

Postless Tape Augmentation for Posterior Cruciate Ligament Reconstruction.

Many techniques have been described for posterior cruciate ligament (PCL) reconstruction, but residual laxity remains an ongoing challenge. Suture or tape augmentation during ligament reconstruction has become a popular option to prevent graft elongation but comes at the expense of additional costs due to implants for augment fixation, and concern for stress shielding of the graft if the augment and graft are not equally tensioned. We introduce a technique for postless tape augmentation during allograft PCL reconstruction that allows for equal tensioning of graft and augment through the use of a sheath and screw construct without the need for additional implants for augment fixation.

Literature Review of Subscapularis Tear, Associated injuries, and the Available Treatment Options.

The population of Hawai'i is uniquely connected to the Ocean and to open water sports. Shoulder injuries, particularly those to the rotator cuff, are among the most common injuries sustained to athletes participating in ocean sports such as surfing, paddling, and swimming. In addition, rotator cuff injuries increase in prevalence with advanced age. As a consequence, the number of patients in Hawai'i who present with an injury to the subscapularis tendon will continue to rise. However, limited research has been done to delineate the involvement of subscapularis injuries in this population. This article covers the anatomy and function of the subscapularis, the epidemiology and classification of tears in this tendon, and the management of tears. The anatomy section will cover innervation, vascular supply and insertional anatomy of the subscapularis tendon. The function of the subscapularis in regards to both stability and motion of the glenohumeral joint will be examined. The focus of the article will then shift to the tears of the subscapularis, starting with an in depth look at the epidemiology and classification of these tears. The article will then cover the different imaging modalities and their utility in regards to subscapularis tears. Finally, the operative and non-operative management and indications for each modality will be discussed in detail.

Effectiveness of Accelerated Recovery Performance for Post-ACL Reconstruction Rehabilitation.

Atrophy and protracted recovery of normal function of the ipsilateral quadriceps femoris muscle following anterior cruciate ligament reconstruction surgery is well documented. The Accelerated Recovery Performance trainer is a type of electrical stimulation device that delivers a high-pulse frequency via a direct current, making it unique from many other devices on the market. The purpose of the present study was to investigate the effects of the direct current (via the Accelerated Recovery Performance trainer protocol) on gains in thigh circumference following anterior cruciate ligament reconstruction. Twenty-five patients were enrolled following isolated anterior cruciate ligament reconstruction and randomly assigned to either an isometric rehabilitation protocol augmented with the Accelerated Recovery Performance trainer protocol (experimental group) or the isometric rehabilitation protocol alone (control group). The two groups participated in sixteen sessions of directed rehabilitation over a two-month time period. Patients were followed with serial thigh circumference measurements at 5, 10, 15, and 20 centimeters above the superior patellar pole. Comparison of the overall mean circumferential gains in thigh circumference of the involved leg demonstrated approximately 3:1 gains in the ARP group over the control group, demonstrating it to be superior to isometric rehabilitation alone with regards to gains in thigh girth. The Accelerated Recovery Performance trainer protocol should be considered for post-anterior cruciate ligament reconstruction rehabilitation in order to reverse disuse atrophy of the ipsilateral quadriceps femoris.

Computer-animated model of accommodation and presbyopia.

PURPOSE: To understand, demonstrate, and further research the mechanisms of accommodation and presbyopia. SETTING: Private practice, Little Silver, New Jersey, USA. DESIGN: Experimental study. METHODS: The CAMA 2.0 computer-animated model of accommodation and presbyopia was produced in collaboration with an experienced medical animator using Autodesk Maya animation software and Adobe After Effects. RESULTS: The computer-animated model demonstrates the configuration and synchronous movements of all accommodative elements. A new classification of the zonular apparatus based on structure and function is proposed. There are 3 divisions of zonular fibers; that is, anterior, crossing, and posterior. The crossing zonular fibers form a scaffolding to support the lens; the anterior and posterior zonular fibers work reciprocally to achieve focused vision. The model demonstrates the important support function of Weiger ligament. Dynamic movement of the ora serrata demonstrates that the forces of ciliary muscle contraction store energy for disaccommodation in the elastic choroid. The flow of aqueous and vitreous provides strong evidence for our understanding of the hydrodynamic interactions during the accommodative cycle. The interaction may result from the elastic stretch in the choroid transmitted to the vitreous rather than from vitreous pressue. The model supports the concept that presbyopia results from loss of elasticity and increasing ocular rigidity in both the lenticular and extralenticular structures. CONCLUSION: The computer-animated model demonstrates the structures of accommodation moving in synchrony and might enhance understanding of the mechanisms of accommodation and presbyopia. FINANCIAL DISCLOSURE: Dr. Goldberg is a consultant to Acevision, Inc., and Bausch & Lomb.

Computer-animated model of accommodation and theory of reciprocal zonular action.

This report presents a computer-animated model of the structures of accommodation based on new understanding of the anatomy of the zonular apparatus integrated with current understanding of the mechanism of accommodation. Analysis of this model suggests a new, consolidated theory of the mechanism of accommodation including a new theory of reciprocal zonular action. A three-dimensional animated model of the eye in accommodation and disaccommodation was produced in collaboration with an experienced medical animator. Current understanding of the anatomy of the zonule and the attachments of the vitreous zonule to the anterior hyaloid membrane is incomplete. Recent studies have demonstrated three components of the vitreous zonule: (1) anterior vitreous zonule (previously "hyalocapsular" zonule), which attaches the ciliary plexus in the valleys of the ciliary processes to the anterior hyaloid membrane in the region medial to the ciliary body and Weiger's ligament; (2) intermediate vitreous zonule, which attaches the ciliary plexus to the anterior hyaloid peripherally; and (3) posterior vitreous zonule, which creates a sponge-like ring at the attachment zone that anchors the pars plana zonules. The pars plana zonules attach posteriorly to the elastic choroid above the ora serrata. Analysis of the computer-animated model demonstrates the synchronized movements of the accommodative structures in accommodation and disaccommodation. Utilizing model-based reasoning, it is shown that the posterior zonules attach to and provide traction to the anterior vitreous membrane and Weiger's ligament. This model supports the concept that the ciliary body/zonule/anterior hyaloid complex contributes to the changes in the posterior lens capsule during accommodation, supporting an extralenticular component to accommodation and demonstrating an alternative to the "vitreous support" theories. There is a reciprocal action of the anterior zonules and the posterior zonules. During ciliary body contraction, the anterior zonules lose tension while the posterior zonules stretch and exert force on the posterior lens capsule playing a role in shaping the posterior lens thickness and curvature. During ciliary body relaxation, the posterior zonules lose tension as the lens flattens and is pulled back by the increasing tension of the anterior zonules.

Connexin43 deficiency reduces the sensitivity of cortical bone to the effects of muscle paralysis.

We have shown previously that the effect of mechanical loading on bone depends in part on connexin43 (Cx43). To determine whether Cx43 is also involved in the effect of mechanical unloading, we have used botulinum toxin A (BtxA) to induce reversible muscle paralysis in mice with a conditional deletion of the Cx43 gene in osteoblasts and osteocytes (cKO). BtxA injection in hind limb muscles of wild-type (WT) mice resulted in significant muscle atrophy and rapid loss of trabecular bone. Bone loss reached a nadir of about 40% at 3 weeks after injection, followed by a slow recovery. A similar degree of trabecular bone loss was observed in cKO mice. By contrast, BtxA injection in WT mice significantly increased marrow area and endocortical osteoclast number and decreased cortical thickness and bone strength. These changes did not occur in cKO mice, whose marrow area is larger, osteoclast number higher, and cortical thickness and bone strength lower relative to WT mice in basal conditions. Changes in cortical structure occurring in WT mice had not recovered 19 weeks after BtxA injection despite correction of the early osteoclast activation and a modest increase in periosteal bone formation. Thus BtxA-induced muscle paralysis leads to rapid loss of trabecular bone and to changes in structural and biomechanical properties of cortical bone, neither of which are fully reversed after 19 weeks. Osteoblast/osteocyte Cx43 is involved in the adaptive responses to skeletal unloading selectively in the cortical bone via modulation of osteoclastogenesis on the endocortical surface.

Comparison of myopes and hyperopes after laser in situ keratomileusis monovision.

PURPOSE: To compare the results of laser in situ keratomileusis (LASIK) monovision in myopes and hyperopes. SETTING: Private practice, Little Silver, New Jersey, USA. METHODS: In this retrospective study, 391 consecutive patients older than 40 years who had LASIK between December 1999 and June 2001 were examined. All patients were asked to complete a questionnaire, and study results are based on the analysis of data from patient charts correlated with questionnaire responses. RESULTS: Visual results were excellent in both groups, with all monovision patients achieving 20/30 acuity or better in the distance eye and J2 or better acuity in the near eye. Satisfaction scores were high in all groups. Statistical analysis indicated that visual results for distance were better in myopes than in hyperopes (P =.043), enhancements were higher in monovision (P =.04) and in hyperopia (P =.08), and satisfaction was higher among myopes (P =.012) and full distance patients (P =.002). Monovision hyperopes had the most difficulty with 6 side effects (P =.00). CONCLUSION: Hyperopic monovision was a viable but more problematic solution to correcting presbyopia than myopic monovision.