Fibrillary glomerulonephritis in a patient with rheumatoid arthritis: A case report and review of the literature.

Fibrillary glomerulonephritis (FGN) is a rare glomerular disease defined by the presence of microfibrils that deposit within the glomeruli. While initially thought to be idiopathic, FGN is now recognized to be associated with infection, malignancies, and autoimmune disorders. We describe a case of biopsy-proven FGN in a patient with seropositive rheumatoid arthritis (RA) and provide a review of the literature regarding the association of FGN with RA.

Rotational Deformity-When and How to Address Femoral Anteversion and Tibial Torsion.

Rotational deformity is a less common cause of patellar instability than trochlear dysplasia and patella alta. In some cases, rotational deformity is the primary bony factor producing the instability and should be corrected surgically. More research is needed on what are normal values for femoral version and tibial torsion, as well as when the axial plane alignment needs to be corrected. Many tools can be used to evaluate the axial plane and surgeons should be familiar with each of them. Understanding the advantages and disadvantages of each site for osteotomy will help the surgeon choose the most appropriate osteotomy.

Osteochondritis Dissecans: Current Understanding of Epidemiology, Etiology, Management, and Outcomes.

➤: Osteochondritis dissecans occurs most frequently in the active pediatric and young adult populations, commonly affecting the knee, elbow, or ankle, and may lead to premature osteoarthritis. ➤: While generally considered an idiopathic phenomenon, various etiopathogenetic theories are being investigated, including local ischemia, aberrant endochondral ossification of the secondary subarticular physis, repetitive microtrauma, and genetic predisposition. ➤: Diagnosis is based on the history, physical examination, radiography, and advanced imaging, with elbow ultrasonography and novel magnetic resonance imaging protocols potentially enabling early detection and in-depth staging. ➤: Treatment largely depends on skeletal maturity and lesion stability, defined by the presence or absence of articular cartilage fracture and subchondral bone separation, as determined by imaging and arthroscopy, and is typically nonoperative for stable lesions in skeletally immature patients and operative for those who have had failure of conservative management or have unstable lesions. ➤: Clinical practice guidelines have been limited by a paucity of high-level evidence, but a multicenter effort is ongoing to develop accurate and reliable classification systems and multimodal decision-making algorithms with prognostic value.

Traumatic Glenosphere Dissociation Following Reverse Total Shoulder Endoprosthetic Reconstruction for Proximal Humerus Periosteal Chondrosarcoma: A Case Report.

INTRODUCTION: Reverse total shoulder endoprosthetic reconstruction after margin-negative tumor resection of the proximal humerus is becoming more conventional in orthopeadic oncology practices. Mid-term survival and functional outcomes have been satisfactory. This case report corroborates with current literature and further describes a rare traumatic complication. CASE PRESENTATION: We report a case of a 70-year-old male with periosteal chondrosarcoma of the proximal humerus who underwent margin-negative resection and reverse total shoulder endoprosthetic reconstruction that was complicated by glenosphere dissociation sustained from falling onto a hyperflexed arm. Successful revision arthroplasty was performed. CONCLUSION: Enhancing glenohumeral joint stability after wide resection of the proximal humerus is important to address rotator cuff insufficiency. The greater levering effect of a longer humeral prosthesis used to increase soft tissue tension may also increase the risk of glenosphere dissociation secondary to trauma. Proper soft-tissue tensioning and surgical technique are critical.

Functional Outcomes of Symptomatic Implant Removal Following Ankle Fracture Open Reduction and Internal Fixation.

BACKGROUND: Orthopedic implant removal following open reduction internal fixation of a fracture is a common procedure, especially in the foot and ankle. The purpose of this study was to evaluate functional change after the removal of symptomatic implants following ankle fracture open reduction internal fixation (ORIF) using the Short Musculoskeletal Function Assessment (SMFA) outcome score. We hypothesized that implant removal after ankle fracture would result in improved functional outcomes. METHODS: Retrospective review of prospectively collected data on patients with a closed ankle fracture between 2013 and 2016 was performed. Inclusion criteria were skeletal maturity, symptomatic ankle implants and completion of the SMFA questionnaire prior to and 6 months after removal. Exclusion criteria were development of a nonunion, prior or current infection, peripheral neuropathy or ongoing litigation surrounding the surgery. The primary outcome was change in SMFA score from baseline to follow-up using Wilcoxon signed-rank test. Additional logistic regression models evaluated the effects of age, sex, body mass index, smoking status, and patient American Society of Anesthesiologists scores. RESULTS: The study population consisted of 43 patients. There was a statistically significant improvement in function, represented by a decrease in SMFA scores from baseline to the 6-month follow-up period (∆ = -4.1 [95% confidence interval, -7.0, -1.3]; P = .003). Secondary outcome measures of the bother index and daily activities domain also demonstrated significant improvements ( P = .005 and P = .002, respectively). Additional logistical regression models identified no significant effects by assessed covariates for change in SMFA scores. CONCLUSION: Patients with symptomatic implants following ankle fracture ORIF had a statistically significant improvement in function following implant removal. There appears to be value in removing implants from the ankle in patients who report discomfort during daily activities. Further investigation into the specific indications for implant removal and the impact of injury and fracture pattern on outcomes is warranted. LEVEL OF EVIDENCE: Level IV, case series.

Local regulation of growth plate cartilage.

Elongation of bones primarily occurs by endochondral ossification at the growth plate. In the growth plate, stem-like cells in the resting zone differentiate into rapidly dividing chondrocytes in the proliferative zone and then terminally differentiate into nondividing chondrocytes of the hypertrophic zone. The hypertrophic zone is then invaded by blood vessels and bone cell precursors, which remodel the newly formed cartilage into bone. The net effect is that new bone tissue is progressively generated at the bottom of the growth plate, resulting in bone elongation. The process of longitudinal bone growth is governed by a complex network of paracrine signals that maintain the unique structure and cellular kinetics of the growth plate. Recent progress in the understanding of important paracrine signals that regulate growth plate cartilage will be reviewed in this chapter.

Organization of the Indian hedgehog--parathyroid hormone-related protein system in the postnatal growth plate.

In embryonic growth cartilage, Indian hedgehog (Ihh) and parathyroid hormone-related protein (PTHrP) participate in a negative feedback loop that regulates chondrocyte differentiation. Postnatally, this region undergoes major structural and functional changes. To explore the organization of the Ihh­PTHrP system in postnatal growth plate, we microdissected growth plates of 7-day-old rats into their constituent zones and assessed expression of genes participating in the h­PTHrP feedback loop. Ihh, Patched 1, Smoothened, Gli1, Gli2, Gli3, and Pthr1 were expressed in regions analogous to the expression domains in embryonic growth cartilage. However, PTHrP was expressed in resting zone cartilage, a site that differs from the embryonic source, the periarticular cells. We then used mice in which lacZ has replaced coding sequences of Gli1 and thus serves as a marker for active hedgehog signaling. At 1, 4, 8, and 12 weeks of age, lacZ expression was detected in a pattern analogous to that of embryonic cartilage. The findings support the hypothesis that the embryonic Ihh­PTHrP feedback loop is maintained in the postnatal growth plate except that the source of PTHrP has shifted to a more proximal location in the resting zone.