Risk of Injury to Neurovascular Structures During Open Cerclage Wiring of the Femur: A Cadaveric Study.

The objective of this study was to examine the risk to the sciatic nerve and femoral artery during open passage of cerclage wires and to evaluate the safest techniques. After a standard lateral approach, cerclage passes along the femur were made in cadaveric specimens. Distance to the sciatic nerve and femoral artery was recorded. Careful technique resulted in an increase in distance to the sciatic nerve and femoral artery. There was an increase in the distance to the femoral artery with passes in an anterior to posterior direction. There was decreased distance to structures proximally and distally. There was a trend toward increased safety with smaller passers. Open cerclage wiring of the femur is safest if proper technique is used, care is taken at the proximal and distal ends of the femur, passes are made in an anterior to posterior direction, and the smallest cerclage passer that can be passed is utilized.

Effects of Obesity on Health Related Quality of Life Following Total Hip Arthroplasty.

Obesity is known to negatively impact health related quality of life (HRQoL). Although non-disease specific tools have been used to study HRQoL after THA in obese patients, these do not directly measure health utility improvements. All 435 THA patients in the current study, regardless of BMI, reported improvement in HRQoL as measured by EQ-5D, a universal, standardized, non-disease specific preference-based instrument. These data suggest obese patients value their quality of life improvement following THA as much as non-obese patients. Furthermore, the increased activity level observed following THA in obese patients suggests obese patients may also obtain non-disease specific benefits of a more active lifestyle. This information is important for future assessments of value and cost-effectiveness of THA in the obese population.

Long-term survival and differentiation of retinal neurons derived from human embryonic stem cell lines in un-immunosuppressed mouse retina.

PURPOSE: To examine the potential of NIH-maintained human embryonic stem cell (hESC) lines TE03 and UC06 to differentiate into retinal progenitor cells (hESC-RPCs) using the noggin/Dkk-1/IGF-1/FGF9 protocol. An additional goal is to examine the in vivo dynamics of maturation and retinal integration of subretinal and epiretinal (vitreous space) hESC-RPC grafts without immunosuppression. METHODS: hESCs were neuralized in vitro with noggin for 2 weeks and expanded to derive neuroepithelial cells (hESC-neural precursors, NPs). Wnt (Integration 1 and wingless) blocking morphogens Dickkopf-1 (Dkk-1) and Insulin-like growth factor 1 (IGF-1) were used to direct NPs to a rostral neural fate, and fibroblast growth factor 9 (FGF9)/fibroblast growth factor-basic (bFGF) were added to bias the differentiation of developing anterior neuroectoderm cells to neural retina (NR) rather than retinal pigment epithelium (RPE). Cells were dissociated and grafted into the subretinal and epiretinal space of young adult (4-6-week-old) mice (C57BL/6J x129/Sv mixed background). Remaining cells were replated for (i) immunocytochemical analysis and (ii) used for quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis. Mice were sacrificed 3 weeks or 3 months after grafting, and the grafts were examined by histology and immunohistochemistry for survival of hESC-RPCs, presence of mature neuronal and retinal markers, and the dynamics of in vivo maturation and integration into the host retina. RESULTS: At the time of grafting, hESC-RPCs exhibited immature neural/neuronal immunophenotypes represented by nestin and neuronal class III ß-tubulin, with about half of the cells positive for cell proliferation marker Kiel University -raised antibody number 67 (Ki67), and no recoverin-positive (recoverin [+]) cells. The grafted cells expressed eye field markers paired box 6 (PAX6), retina and anterior neural fold homeobox (RAX), sine oculis homeobox homolog 6 (SIX6), LIM homeobox 2 (LHX2), early NR markers (Ceh-10 homeodomain containing homolog [CHX10], achaete-scute complex homolog 1 [MASH1], mouse atonal homolog 5 [MATH5], neurogenic differentiation 1 [NEUROD1]), and some retinal cell fate markers (brain-specific homeobox/POU domain transcription factor 3B [BRN3B], prospero homeobox 1 [PROX1], and recoverin). The cells in the subretinal grafts matured to predominantly recoverin [+] phenotype by 3 months and survived in a xenogenic environment without immunosuppression as long as the blood-retinal barrier was not breached by the transplantation procedure. The epiretinal grafts survived but did not express markers of mature retinal cells. Retinal integration into the retinal ganglion cell (RGC) layer and the inner nuclear layer (INL) was efficient from the epiretinal but not subretinal grafts. The subretinal grafts showed limited ability to structurally integrate into the host retina and only in cases when NR was damaged during grafting. Only limited synaptogenesis and no tumorigenicity was observed in grafts. CONCLUSIONS: Our studies show that (i) immunosuppression is not mandatory to xenogenic graft survival in the retina, (ii) the subretinal but not the epiretinal niche can promote maturation of hESC-RPCs to photoreceptors, and (iii) the hESC-RPCs from epiretinal but not subretinal grafts can efficiently integrate into the RGC layer and INL. The latter could be of value for long-lasting neuroprotection of retina in some degenerative conditions and glaucoma. Overall, our results provide new insights into the technical aspects associated with cell-based therapy in the retina.

A comparison of perioperative outcomes in patients with and without rheumatoid arthritis after receiving a total shoulder replacement arthroplasty.

HYPOTHESIS: The long-term survival rate of total shoulder arthroplasty (TSA) is comparable to hip and knee arthroplasty. Although TSA is considered a safe and effective procedure with low complications in patients with osteoarthritis and rheumatoid arthritis (RA), data are lacking on perioperative complications. Complication rates and hospital disposition differences between patients with and without RA who underwent TSA were investigated. We hypothesized that RA patients would have poorer perioperative outcomes after TSA. MATERIALS AND METHODS: Data from the Nationwide Inpatient Sample was used to capture 25,398 patients between 1988 and 2005 who underwent TSA. Of these, 1,186 patients had a primary diagnosis of RA and were compared with 24,212 patients without RA. Analyses addressed perioperative complications and hospital disposition factors using bivariate and logistic regression models. RESULTS: Overall complication rates were exceptionally low in both groups. Hospital disposition factors were significantly different between the 2 groups. The RA cohort had shorter average lengths of stay, higher likelihood of routine discharge, and lower inflation-adjusted cost before and after adjustment for covariates. DISCUSSION: The occurrence of complications in the perioperative setting was less than 1% for both study groups in most variables investigated, and there were only minimal differences in perioperative complications between the groups. The significant differences in hospital disposition factors suggest that patients with RA may have less complex hospital stays and may be more comfortable being discharged under their own care. Recent studies describing the overall improvement in the management of patients with RA may also help explain these findings. CONCLUSIONS: The findings suggest that the perioperative complications of a total shoulder replacement for patients with and without RA are similar. Contrary to our expectations, TSA patients with RA had shorter and less costly hospital stays and were more likely to have routine discharge. Complications are likely more long-term in nature than detected in this study and require longer follow-up beyond perioperative periods for fruition.

Fracture of highly cross-linked all-polyethylene patella after total knee arthroplasty.

Recent advances in polyethylene fabrication have led to the introduction of highly cross-linked polyethylene tibial and patellar components for use in total knee arthroplasty (TKA) with the goal of reducing wear-related osteolysis. However, some reports suggest decreased mechanical strength as a result of the additional thermal and sterilization treatments in the manufacturing of implants. Complications related to the patella are among the most common causes of failure in TKA, but patellar component fracture is rare. The authors report a case of a highly cross-linked all-polyethylene patellar component that failed as a result of fracture in vivo in a patient 3 years after TKA.

Revisiting Tension Band Fixation for Difficult Patellar Fractures.

Patella fractures with comminution, osteoporotic bone, and/or previously failed fixation are exceedingly difficult to reduce and fix. Moreover, the risk of symptomatic constructs and patients who are poorly compliant with postoperative activity restrictions can make these complex fracture patterns an even more challenging scenario. Although there is an array of techniques described for comminuted patella fractures, there lacks an accepted surgical technique for these difficult cases. In this clinical series, we describe an enhancement to the traditional tension band construct that uses additional wires and multiple tension bands to gather and fix comminuted fracture patterns in nontransverse planes, bolster osteoporotic bone, and secure fractures in patients undergoing a revision and/or have potential to be poorly compliant with postoperative activity restrictions. The clinical outcomes of 27 patients demonstrate high rates of bony union, functional range of motion, and low rates of both infection and failure. In conclusion, using the basic principles of tension band wiring remains highly versatile, useful, and economical in approaching difficult patella fractures.

Unique Case of Posterior Tibial Tendon Dysfunction After Stingray Strike.

BACKGROUND: Posterior tibial tendon dysfunction is a common cause of adult acquired flatfoot deformity. The cause of posterior tibial tendon dysfunction is often multifactorial and may include repetitive microtrauma, poor blood supply to the tendon, and, rarely, traumatic rupture. CASE DESCRIPTION: We present the case of a 69-year-old male with posterior tibial tendon dysfunction secondary to a stingray injury that occurred directly into the posterior tibial tendon. This injury led to an acquired adult flatfoot deformity that ultimately required surgical reconstruction. At the time of surgery, the posterior tibial tendon was severely degenerative at the site of skin penetration. LITERATURE REVIEW: Previous case reports of stingray injury describe full-thickness skin penetration with a subsequent inflammatory response and large zone of necrobiosis. This is the first reported case of stingray trauma and envenomation directly into tendon with subsequent tendon dysfunction. CLINICAL RELEVANCE: There are thousands of stingray injuries in the United States annually. Injuries vary in severity depending on the type of stingray, size of stingray, and depth and location of injury. For certain injuries, such as direct penetration into tendon, early irrigation and debridement may limit subsequent deficits caused by progressive tendon dysfunction. LEVELS OF EVIDENCE: Therapeutic, Level IV: Case study.

Distinct nuclear localization patterns of DNA methyltransferases in developing and mature mammalian retina.

DNA methyltransferases--DNMT1, DNMT3a, and DNMT3b--produce methylation patterns that dynamically regulate chromatin remodeling and gene expression. The vertebrate retina provides an ideal model to elucidate molecular control of neurogenesis as all neuronal cell types and Müller glia are generated in a conserved order from common pools of progenitor cells. As a prelude to exploring epigenetic regulation of mammalian retinal development, we investigated the expression of Dnmt1, Dnmt3a, and Dnmt3b in the mouse retina from embryonic day (E) 10.5 to 10 months of age. High levels of transcripts for all three Dnmt genes were observed in early stages of retinal differentiation, with significantly reduced expression after birth. Although DNMT1 protein is abundant in retinal progenitors at E10.5, it becomes restricted to postmitotic cells by E15.5. Most cells in the postnatal retina show nuclear immunostaining of DNMT1; however, the photoreceptors exhibit distinctive patterns. In rods, weak expression of DNMT1 is detected in perinuclear region and in the nucleus, whereas a strong nuclear labeling is evident in cones. DNMT3a and DNMT3b show a discrete pattern in developing retina with high expression at E11.5, little or no immunostaining by E15.5, and then postnatal expression overlapping with DNMT1 in early born neurons (ganglion, amacrine and horizontal cells, and cones). Robust nuclear localization of DNMTs in cones compared to rods suggests a potential role of DNA methylation in differential remodeling of chromatin in these two specialized neurons. Our studies indicate that DNA methyltransferases contribute to the establishment and maturation of cell fates during retinal development.