Treatment of femoroacetabular impingement: a systematic review

The purpose of this review is to determine if there is a difference in outcomes after: (1) nonsurgical vs surgical treatment of FAI; (2a) surgical dislocation with greater trochanteric osteotomy, (2b) anterior mini-open, (2c) arthroscopic plus mini-open, and (2d) arthroscopic surgery for FAI; (3) difference in complication and re-operation rates; and (4a) labral refixation and (4b) labral debridement for labral injuries. A systematic review of multiple databases was performed after PROSPERO registration and using PRISMA guidelines. Level I-IV evidence clinical studies with minimum 2-year follow-up were included. Data were compared using 2-sample and 2-proportion Z-test calculators. Study methodological quality was analyzed using Modified Coleman Methodology Score (MCMS). Recommendations were made using SORT (Strength Of Recommendation Taxonomy). Twenty-nine studies were included (2369 subjects; 2507 hips). MCMS was poor. Mean subject age was 34.4+/−8.4 years and mean follow-up was 3.1+/−0.9 years. Statistically significant differences were observed following both nonsurgical and surgical treatment, with greater (P < 0.05) improvements following surgery (SORT B), without consistent significant differences observed between different surgical techniques (SORT C). There was a greater (P < 0.05) reoperation and complication rate following surgical dislocation vs mini-open and arthroscopic techniques (SORT A). Clinical outcomes were significantly better (P < 0.05) following labral refixation vs debridement (SORT B). Outcomes of operative treatment of femoroacetabular impingement are significantly better than nonsurgical management. Surgical treatment significantly improves outcomes, with no consistent significant differences exhibited between open and arthroscopic techniques. Open surgical dislocation has significantly greater reoperation and complication rates vs mini-open and arthroscopic techniques. Outcomes of labral refixation are significantly better than debridement in patients with labral injuries.     

Contact lens material characteristics associated with hydrogel lens dehydration

Purpose: To determine the association between material dehydration and hydrogel contact lens material characteristics, including water content and ionicity. Methods: Water content and refractive index data were derived from automated refractometry measurements of worn hydrogel contact lenses of 318 participants in the Contact Lens and Dry Eye Study (CLADES). Dehydration was determined in two ways; as the difference between nominal and measured (1) water content and (2) refractive index. Multiple regression models were used to examine the relation between dehydration and material characteristics, controlling for tear osmolality. Results: The overall measured and nominal water content values were 52.58 ± 7.49% and 56.88 ± 7.81% respectively, while the measured and nominal refractive indices were 1.429 ± 0.015 and 1.410 ± 0.017. High water content and ionic hydrogel lens materials were associated with greater dehydration (p < 0.0001 for both) than low water content and non‐ionic materials. When dehydration was assessed as the difference in refractive index, only high water content was associated with dehydration (p < 0.0001). Conclusions: High water content and ionic characteristics of hydrogel lens materials are associated with hydrogel lens dehydration, with the former being more strongly associated. Such dehydration changes could in turn lead to important clinical ramifications such as reduced oxygen transmissibility, greater lens adherence and reduced tear exchange.     

Pullout strength of suture anchors in comparison with transosseous sutures for rotator cuff repair

Suture anchors are increasingly gaining importance in rotator cuff surgery. This means they will be gradually replacing transosseous sutures. The purpose of this study was to compare the stability of transosseous sutures with different suture anchors with regard to their pullout strength depending on bone density. By means of bone densitometry (CT scans), two groups of human humeral head specimens were determined: a healthy and a osteopenic bone group. Following anchor systems were being tested: SPIRALOK™ 5.0 mm (resorbable, DePuy Mitek), Super Revo 5 mm (titanium, Linvatec), UltraSorb (resorbable, Linvatec) and the double U-sutures with Orthocord™ USP 2 (partly resorbable, DePuy Mitek) and Ethibond Excel 2 (non-resorbable, Ethicon). The suture anchors/double U-sutures were inserted in the greater tuberosity 12 times. An electromechanical testing machine was used for cyclic loading with power increasing in stages. We recorded the ultimate failure loads, the system displacements and the modes of failure. The suture anchors tended to bring about higher ultimate failure loads than the transosseous double U-sutures. This difference was significant in the comparison of the Ethibond suture and the SPIRALOK 5.0 mm—both in healthy and osteopenic bone. Both the suture materials and the SPIRALOK 5.0 mm showed a significant difference in pullout strength on either healthy or osteopenic bone; the titanium anchor SuperRevo 5 mm and the tilting anchor UltraSorb did not show any significant difference in healthy or osteopenic bone. There was no significant difference concerning system displacement (healthy and osteopenic bone) between the five anchor systems tested. The pullout strength of transosseous sutures is neither on healthy nor on osteopenic bone higher than that of suture anchors. Therefore, even osteopenic bone does not constitute a valid reason for the surgeon to perform open surgery by means of transosseous sutures. The choice of sutures in osteopenic bone is of little consequence anyway since it is mostly the bone itself which is the limiting factor.     

Interaction of EGF family growth factors and neurotransmitters in regulating lacrimal gland secretion

The lacrimal gland is the primary source for the aqueous portion of the tear film. This portion contains water, electrolytes and proteins, which are necessary for the health and maintenance of the cells of the ocular surface. Afferent sensory nerves in the cornea and conjunctiva stimulate efferent parasympathetic and sympathetic nerves in the lacrimal gland. Cholinergic agonists, released from parasympathetic nevres, and norepinephrine, released from sympathetic nerves, are major stimuli of lacrimal gland secretion. These neurotransmitters activate distinct, but overlapping signal transduction pathways leading to lacrimal gland secretion. Other stimuli of lacrimal gland secretion are the EGF family of growth factors. In addition to stimulation of secretion, these growth factors can interact with the cells of the lacrimal gland themselves or with the cells of the ocular surface depending upon the location from which these growth factors are released. This review will focus on the effects of the EGF family of growth factors on the lacrimal gland and their interactions with the pathways stimulated by the neurotransmitters released from nerves.     

The lipid layer of tears: dependent on meibomian gland function

There is growing laboratory and clinical evidence implicating the meibomian glands of the eyelid as playing a critical role in the pathogenesis of various ocular surface disorders such as chronic blepharitis and dry eye. Meibomian glands produce a lipid material whose synthesis is dependent on factors such as stem cells, neurological stimulants and hormones. This lipid material is fluid, spreads easily, is a surfactant as well as an aqueous barrier, and must remain functional after a blink. Before delivery it can be modified by factors such as hormone abnormalities and even after delivery it may be modified by lipases produced by ocular bacteria.