Early Correction of Distal Radius Partial Articular Malunion Leads to Good Long-term Functional Recovery at Mean Follow-up of 4 Years.

Background: Distal radius articular step-off or deformity may cause posttraumatic arthritis and poor functional outcome. The purpose of this study was to evaluate pain and functional outcomes in patients with malunited partial articular distal radius fractures who underwent corrective osteotomy. We hypothesized that anatomic restoration of distal radius articular surface after a malunited partial articular distal radius fracture results in improvement in pain and functional measures and delays the development of posttraumatic arthritis. Methods: Seven consecutive patients with mean age of 38 years underwent corrective osteotomy via either a standard dorsal approach or combined dorsal and volar approach. Mean time from injury to corrective osteotomy was 10 weeks. Patients were assessed with respect to Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH), forearm and wrist range of motion, pain, and grip strength. Results: At mean follow-up of 44 months, significant improvements in pain scores (7.1-0.9, P < .001), QuickDASH (38.7-11.6, P < .001), grip strength (21.4-30.0 kg, P = .01) were achieved. All range of motion measurements demonstrated significant improvements except forearm pronation. One patient demonstrated radiographic evidence of osteoarthritis but had no pain at final follow-up. No patients required secondary surgery for removal of symptomatic hardware. Conclusions: Based on these findings, we recommend that early corrective osteotomies should be considered in young patients with intra-articular distal radius malunions before considering salvage procedures such as partial or complete wrist arthrodesis.

Determinants of Pain and Predictors of Pain Relief after Ulnar Shortening Osteotomy for Ulnar Impaction Syndrome.

Background The purpose of this study is to characterize patient- and surgery-specific factors associated with perioperative pain level in patients undergoing ulnar shortening osteotomy (USO) for ulnar impaction syndrome (UIS). We hypothesize that preoperative opiate consumption, tobacco utilization, and severity of ulnar variance will be associated with less postoperative pain relief. Methods All cases of USO between January 2010 and December 2016 for management of UIS were retrospectively reviewed. Patient demographics, smoking status, type of labor, and opioid utilization before surgery were recorded. Radiographic measurements for ulnar variance, radial tilt and inclination, as well as triangular fibrocartilage complex and distal radial-ulnar joint (DRUJ) morphology were assessed. Pre- and postoperative pain score were recorded. Regression analysis was performed to determine predictors of pain scores. Results A total of 69 patients were included for the final analysis with a mean age of 44 years (range 17-73 years). Seventeen patients reported use of daily opioid medications at the time of surgery (25%). Patients who used opioid analgesics daily, active laborers, smokers, and patients involved in worker compensation claims had significantly less pain relief after surgery. Patients with osteotomy performed at the metaphysis had significantly more pain relief than patients that had diaphyseal osteotomy. Regression analysis identified tobacco utilization and anatomic site of osteotomy as independent predictors of postoperative pain. Conclusion The results from this study identified smoking and location of osteotomy as independent predictors of postoperative pain relief. While smoking cessation is paramount to prevent delayed/nonunion it may also help improve pain relief following USO. The potential to achieve greater shortening with a metaphyseal osteotomy suggests that in addition to the mechanical unloading the carpus, pain relief after USO may also stem from tensioning the ulnar collateral ligaments of the wrist, the ECU subsheath, and the radioulnar ligaments. Level of Evidence This is a Level III, therapeutic study.

Canonical Wnt signaling regulates patterning, differentiation and nucleogenesis in mouse hypothalamus and prethalamus.

The hypothalamus is a small, but anatomically and functionally complex region of the brain whose development is poorly understood. In this study, we have explored its development by studying the canonical Wnt signaling pathway, generating gain and loss of function mutations of beta-catenin (Ctnnb1) in both hypothalamic and prethalamic neuroepithelium. Deletion of Ctnnb1 resulted in an anteriorized and hypoplastic hypothalamus. Posterior structures were lost or reduced, and anterior structures were expanded. In contrast, overexpression of a constitutively active mutant form of Ctnnb1 resulted in severe hyperplasia of prethalamus and hypothalamus, and expanded expression of a subset of posterior and premamillary hypothalamic markers. Moderate defects in differentiation of Arx-positive GABAergic neural precursors were observed in both prethalamus and hypothalamus of Ctnnb1 loss of function mutants, while in gain of function mutants, their differentiation was completely suppressed, although markers of prethalamic progenitors were preserved. Multiple other region-specific markers, including several specific posterior hypothalamic structures, were also suppressed in Ctnnb1 gain of function mutations. Severe, region-specific defects in hypothalamic nucleogenesis were also observed in both gain and loss of function mutations of Ctnnb1. Finally, both gain and loss of function of Ctnnb1 also produced severe, non-cell autonomous disruptions of pituitary development. These findings demonstrate a central and multifaceted role for canonical Wnt signaling in regulating growth, patterning, differentiation and nucleogenesis in multiple diencephalic regions.

Minimally Invasive Proximal Interphalangeal Joint Arthrodesis Using Headless Screw: Surgical Technique.

Proximal interphalangeal (PIP) joint arthritis causes debilitating hand pain and instability leading to significant functional impairment. Arthrodesis remains the gold standard for treatment of PIP arthritis. We present a minimally invasive PIP arthrodesis that provides rigid fixation with a headless compression screw. Seven patients who presented to the senior author with PIP joint arthritis underwent PIP arthrodesis by minimally invasive technique. A 1 cm transverse incision is made over the PIP joint, incising skin, central band, and articular capsule. PIP joint is flexed to expose the articular surface. Articular surfaces are prepared with a fine tipped rongeur, exposing subchondral bone until flat surfaces are obtained. Under fluoroscopy a guide wire for cannulated headless screw (3.0, 2.4, or 2.0 mm) is inserted in an antegrade manner. It progresses from the center of the proximal phalangeal articular surface until it exits through the dorsal cortex and the distal end lies within the subchondral bone. This is the most critical step of the procedure because the guide wire angle determines the degree of flexion of the fusion. A 5 mmincision is made over the guide wire and the wire is advanced through the center of the medullary canal of the middle phalanx. The wire is then overdrilled, length is measured, and a headless compression screws is inserted. Reevaluate alignment after insertion of the screws because malrotation may be induced by torque during compression. Six consecutive patients underwent the procedure by the senior author. All patients healed the arthrodesis without complications and hardware removal was not needed. Minimally invasive PIP joint arthrodesis is a safe and viable procedure. Critical portions of the procedure include placing the wire at the angle of the desired angle of fusion and avoiding malrotation during screw insertion.

Foxd1 is required for terminal differentiation of anterior hypothalamic neuronal subtypes.

Although the hypothalamus functions as a master homeostat for many behaviors, little is known about the transcriptional networks that control its development. To investigate this question, we analyzed mice deficient for the Forkhead domain transcription factor Foxd1. Foxd1 is selectively expressed in neuroepithelial cells of the prethalamus and hypothalamus prior to the onset of neurogenesis, and is later restricted to neural progenitors of the prethalamus and anterior hypothalamus. During early stages of neurogenesis, we observed that Foxd1-deficient mice showed reduced expression of Six3 and Vax1 in anterior hypothalamus, but overall patterning of the prethalamus and hypothalamus is unaffected. After neurogenesis is complete, however, a progressive reduction and eventual loss of expression of molecular markers of the suprachiasmatic, paraventricular and periventricular hypothalamic is observed. These findings demonstrate that Foxd1 acts in hypothalamic progenitors to allow sustained expression of a subset of genes selectively expressed in mature neurons of the anterior hypothalamus.

Incidence of heterotopic ossification in direct anterior vs posterior approach to total hip arthroplasty: a retrospective radiographic review.

PURPOSE: To investigate the prevalence of heterotopic ossification following direct anterior approach total hip arthroplasty compared to posterior approach, performed by a single surgeon at one institution METHODS: All primary THAs performed by the senior author (JEL) over a 70-month period were reviewed, including 235 DAA and 120 posterior THAs. Brooker's system was used to grade HO at a minimum of six months follow-up. RESULTS: Patients undergoing DAA were less likely to develop clinically significant HO compared to posterior THA (p = 0.04). The overall incidence of HO following DAA THA was 24.3 % (3 % grade 3 and 0 % grade 4), and following posterior THA was 27.5 % (4.2 % grade 3 and 3.3 % grade 4). CONCLUSIONS: Lower rates of clinically significant (Brooker grade 3 and 4) HO were observed in DAA THA than in posterior approach THA. This data may be instructive when approaching THA candidates with conditions that predispose them to HO.

Patterning, specification, and differentiation in the developing hypothalamus.

Owing to its complex structure and highly diverse cell populations, the study of hypothalamic development has historically lagged behind that of other brain regions. However, in recent years, a greatly expanded understanding of hypothalamic gene expression during development has opened up new avenues of investigation. In this review, we synthesize existing work to present a holistic picture of hypothalamic development from early induction and patterning through nuclear specification and differentiation, with a particular emphasis on determination of cell fate. We will also touch on special topics in the field including the prosomere model, adult neurogenesis, and integration of migratory cells originating outside the hypothalamic neuroepithelium, and how these topics relate to our broader theme.

The LIM homeodomain factor Lhx2 is required for hypothalamic tanycyte specification and differentiation.

Hypothalamic tanycytes, a radial glial-like ependymal cell population that expresses numerous genes selectively enriched in embryonic hypothalamic progenitors and adult neural stem cells, have recently been observed to serve as a source of adult-born neurons in the mammalian brain. The genetic mechanisms that regulate the specification and maintenance of tanycyte identity are unknown, but are critical for understanding how these cells can act as adult neural progenitor cells. We observe that LIM (Lin-11, Isl-1, Mec-3)-homeodomain gene Lhx2 is selectively expressed in hypothalamic progenitor cells and tanycytes. To test the function of Lhx2 in tanycyte development, we used an intersectional genetic strategy to conditionally delete Lhx2 in posteroventral hypothalamic neuroepithelium, both embryonically and postnatally. We observed that tanycyte development was severely disrupted when Lhx2 function was ablated during embryonic development. Lhx2-deficient tanycytes lost expression of tanycyte-specific genes, such as Rax, while also displaying ectopic expression of genes specific to cuboid ependymal cells, such as Rarres2. Ultrastructural analysis revealed that mutant tanycytes exhibited a hybrid identity, retaining radial morphology while becoming multiciliated. In contrast, postnatal loss of function of Lhx2 resulted only in loss of expression of tanycyte-specific genes. Using chromatin immunoprecipitation, we further showed that Lhx2 directly regulated expression of Rax, an essential homeodomain factor for tanycyte development. This study identifies Lhx2 as a key intrinsic regulator of tanycyte differentiation, sustaining Rax-dependent activation of tanycyte-specific genes while also inhibiting expression of ependymal cell-specific genes. These findings provide key insights into the transcriptional regulatory network specifying this still poorly characterized cell type.