Matthew J. Teusink

What is the effect of postoperative scapular fracture on outcomes of reverse shoulder arthroplasty

BACKGROUNDnPostoperative scapular fracture is a common complication after reverse shoulder arthroplasty (RSA). The purpose of this study was to determine its effect on RSA patient outcomes.nnnMETHODSnA retrospective, case-control study of 25 nonoperatively treated postoperative scapular fractures after RSA were analyzed with a minimum 2-year follow-up from surgery and 1-year follow-up from fracture. Eligible patients were matched 1:4 to a control group for age, sex, follow-up time, surgery indication, and primary operation vs revision. Outcome measures, including American Shoulder and Elbow Surgeons (ASES) score and range of motion, were compared between fracture cases and controls. Also analyzed were radiographic features, including fracture location (acromion vs scapular spine) and healing.nnnRESULTSnIncidence of scapular fracture after RSA in this series was 3.1%. Fractures occurred from 1 to 94 months postoperatively. The revision rate was higher in the fracture group (8% vs. 2%) but did not reach statistical significance (P = .18). Fracture patients had improved (ΔASES, 21) but inferior clinical outcomes, with a postoperative ASES score of 58.0 compared with 74.2 (P ≤ .001). Change in range of motion also diminished in the fracture group, with a mean gain of 26° forward elevation compared with 76° (P < .001). Fracture location (P = .54) or healing (P = .40) did not affect outcome.nnnCONCLUSIONnPostoperative scapular fractures may occur at any point postoperatively; increasing incidence is likely as longer follow-up becomes available. This complication leads to inferior clinical results compared with controls. However, patients show improvement compared with their preoperative measurements, even at longer-term follow-up. Patients with postoperative scapular fractures may have increased risk of revision.nnnLEVEL OF EVIDENCEnLevel III, case-control study, treatment study.

Results of closed management of acute dislocation after reverse shoulder arthroplasty

BACKGROUNDnPostoperative instability continues to be one of the most common complications limiting outcomes of reverse shoulder arthroplasty (RSA). The optimal management of this complication remains unknown. The purpose of this study was to evaluate the outcomes of patients with postoperative dislocation after RSA managed with closed reduction.nnnMETHODSnAll patients who were treated with a closed reduction for dislocation after RSA in the period between May 2002 and September 2011 were identified and retrospectively reviewed. Final outcomes including recurrent instability, need for revision surgery, American Shoulder and Elbow Surgeons outcome score, and range of motion were evaluated.nnnRESULTSnA total of 21 patients were identified. Nearly 50% of cases (10 of 21) had previous surgery, with 80% (8 of 10) of these being previous arthroplasty. The average time to first dislocation was 200 days, with 62% (13 of 21) occurring in the first 90 days. At average follow-up of 28 months, 62% of these shoulders remained stable (13 of 21), 29% required revision surgery (6 of 21), and 9% remained unstable (2 of 21). The average American Shoulder and Elbow Surgeons score was 68.0 for patients treated with closed reduction for instability and 62.7 for those treated with revision surgery (P = .64).nnnDISCUSSIONnThis study shows that an initial dislocation episode after RSA with use of this implant can be successfully managed with closed reduction and temporary immobilization in more than half of cases. Given that outcomes after revision surgery are not different from those after closed treatment, we would continue to recommend an initial attempt at closed reduction in the office setting in all cases of postoperative RSA dislocation.

Expanded 3D Nanofiber Scaffolds: Cell Penetration, Neovascularization, and Host Response

Herein, a robust method to fabricate expanded nanofiber scaffolds with controlled size and thickness using a customized mold during the modified gas-foaming process is reported. The expansion of nanofiber membranes is also simulated using a computational fluid model. Expanded nanofiber scaffolds implanted subcutaneously in rats show cellular infiltration, whereas non-expanded scaffolds only have surface cellular attachment. Compared to unexpanded nanofiber scaffolds, more CD68+ and CD163+ cells are observed within expanded scaffolds at all tested time points post-implantation. More CCR7+ cells appear within expanded scaffolds at week 8 post-implantation. In addition, new blood vessels are present within the expanded scaffolds at week 2. The formed multinucleated giant cells within expanded scaffolds are heterogeneous expressing CD68, CCR7, or CD163 markers. Together, the present study demonstrates that the expanded nanofiber scaffolds promote cellular infiltration/tissue integration, a regenerative response, and neovascularization after subcutaneous implantation in rats. The use of expanded electrospun nanofiber scaffolds offers a promising method for in situ tissue repair/regeneration and generation of 3D tissue models/constructs.

Factors that predict postoperative motion in patients treated with reverse shoulder arthroplasty

BACKGROUNDnReverse shoulder arthroplasty (RSA) has proven to be a useful yet inconsistent tool to manage a variety of pathologic conditions. Factors believed to lead to poor postoperative range of motion (ROM) may be associated with preoperative diagnosis, poor preoperative ROM, and surgical factors such as inability to lengthen the arm. The purpose of this study was to analyze multiple factors that may be predictive of motion after RSA. Our hypothesis is that intraoperative ROM is most predictive of postoperative ROM.nnnMETHODSnBetween February 2003 and April 2011, 540 patients (217 men and 323 women) treated with RSA were evaluated with measurements of preoperative, intraoperative, and postoperative ROM at a follow-up, where ROM was found to have plateaued at 1 year as determined by a pilot study. A regression analysis was performed to define independent predictive factors of postoperative active ROM.nnnRESULTSnIntraoperative forward flexion was the strongest predictor of final postoperative ROM, followed by gender and preoperative ROM. Age and arm lengthening were not significant independent predictors. Controlling for gender and preoperative ROM, patients with an intraoperative elevation of 90° gained 29° in postoperative forward elevation (P < .001), 120° gained approximately 40° in postoperative forward elevation (P < .001), 150° gained approximately 56° in postoperative forward elevation (P < .001) and 180° gained approximately 62° in postoperative forward flexion (P < .001).nnnCONCLUSIONSnIntraoperative forward flexion is the strongest predictor of postoperative ROM. Surgeons may use intraoperative motion as a powerful decision-making tool regarding soft tissue tension in RSA.

Twisting electrospun nanofiber fine strips into functional sutures for sustained co-delivery of gentamicin and silver

Surgical site infections (SSIs) represent the most common nosocomial infection among surgical patients. In order to prevent SSIs in a sustained manner and lessen side effects, we developed a twisting method for generation of nanofiber-based sutures capable of simultaneous delivery of silver and gentamicin. The prepared sutures are composed of core-sheath nanofibers with gentamicin/pluronic F127 in the core and silver/PCL in the sheath produced by co-axial electrospinning. The diameters of obtained sutures range from ~80 μm to ~1.2 mm. The in vitro release profiles of silver and gentamicin exhibit an initial burst followed by a sustained release over 5 weeks. The co-encapsulated sutures were able to kill bacteria much more effectively than gentamicin or silver alone loaded nanofiber sutures, without showing obvious impact on proliferation and migration of dermal fibroblasts and keratinocytes. The gentamicin and silver co-loaded PCL nanofiber sutures may hold great potential for prevention of SSIs.

Binary Doping of Strontium and Copper Enhancing Osteogenesis and Angiogenesis of Bioactive Glass Nanofibers while Suppressing Osteoclast Activity

Electrospun bioactive glass fibers show great potential as scaffolds for bone tissue engineering due to their architectural biomimicry of the bone extracellular matrix and their composition capable of providing soluble bioactive cues for bone regeneration and remodeling. Trace elements can be doped to further promote osteogenesis and angiogenesis during bone regeneration. Cationic substitution of strontium for calcium in bioactive glass positively enhances osteoblast phenotype, while suppressing osteoclast activity. Further, the addition of copper spontaneously improves the vascularization during neobone formation. The objective of this study was to fabricate and characterize electrospun bioactive glass fibers doped with strontium and copper and evaluate their potential for bone repair/regeneration in vitro. Different ratios of strontium and copper were doped in electrospun bioactive glass fibers. The released strontium and copper from doped fibers could reach effective concentrations within 40 h and last for 4 weeks. These bioactive glass fibers demonstrate their bioactivity by promoting osteoblastic and endothelial cell activity and inhibiting the formation of osteoclasts or bone resorbing cells. Additionally, in vitro cell culture of different cell types in the presence of extraction solutions of the electrospun bioactive glass fibers showed that the dopants achieved their individual goals without causing significant cytotoxicity. Altogether, this novel class of bioactive glass fibers holds great promise for bone regeneration.

Highly controlled coating of strontium-doped hydroxyapatite on electrospun poly(ɛ-caprolactone) fibers.

Electrospun fibers show great potential as scaffolds for bone tissue engineering due to their architectural biomimicry to the extracellular matrix (ECM). Cation substitution of strontium for calcium in hydroxyapatite (HAp) positively influences the mechanism of bone remodeling including enhancing bone regeneration and reducing bone resorption. The objective of this study was to attach strontium-doped HAp (SrHAp) to electrospun poly(ɛ-caprolactone) (PCL) fibers for creation of novel composite scaffolds that can not only mimic the architecture and composition of ECM but also affect bone remodeling favorably. We demonstrated for the first time the highly controlled SrHAp coatings on electrospun PCL fibers. We showed the reproducible manufacturing of composite fiber scaffolds with controllable thickness, composition, and morphology of SrHAp coatings. We further showed that the released strontium and calcium cations from coatings could reach effective concentrations within 1 day and endure more than 28 days. Additionally, the Youngs modulus of the SrHAp-coated PCL fibers was up to around six times higher than that of raw fibers dependent on the coating thickness and composition. Together, this novel class of composite fiber scaffolds may hold great promise for bone regeneration.

Kinematic impact of size on the existing glenohumeral joint in patients undergoing reverse shoulder arthroplasty

BACKGROUNDnGlenohumeral relationships in reverse shoulder arthroplasty patients have not been previously reported. The purpose of this study was to quantify and compare the shoulder spatial relationships and moment arms. Measurements were used to define general size categories and determine if sizes scale linearly for all metrics.nnnMETHODSnNinety-two shoulders of patients undergoing primary reverse shoulder arthroplasty for functionally-deficient massive rotator cuff tear without bony deformity or deficiency were evaluated using three-dimensional CT reconstructions and computer-aided design software. Multiple glenohumeral relationships (including moment arm) were measured and evaluated for size stratification and linearity. Generalized linear modeling was used to investigate how predictive glenoid height, coronal humeral head diameter, and gender were of greater tuberosity positions.nnnFINDINGSnThe 92 shoulders were grouped based on glenoid height: small (<33.4mm), medium (33.4-38.0mm), and large (>38.0mm). All relationships varied between groups. The humeral head size, glenoid width, lateral offset, and moment arm all independently increased linearly (r(2)≥0.92) but the rate of increase varied (slope range: 0.59-1.92). Glenoid height, coronal humeral head diameter and gender predicted the greater tuberosity position within mean 1.09mm (standard deviation (SD) 0.84mm) of actual position in 90% of the population.nnnINTERPRETATIONnDistinct groups exist based on the size of the glenoid in shoulder arthroplasty patients. Shoulder modeling should account for size groups, sex, and non-uniform linear scaling of morphometric parameters. Prediction of the greater tuberosity offset can be made using sex and size parameters. Clinical implications include appropriate prosthetic size selection and avoiding large deviations in non-anatomic reconstructions.

Cost Analysis in Shoulder Arthroplasty Surgery

Cost in shoulder surgery has taken on a new focus with passage of the Patient Protection and Affordable Care Act. As part of this law, there is a provision for Accountable Care Organizations (ACOs) and the bundled payment initiative. In this model, one entity would receive a single payment for an episode of care and distribute funds to all other parties involved. Given its reproducible nature, shoulder arthroplasty is ideally situated to become a model for an episode of care. Currently, there is little research into cost in shoulder arthroplasty surgery. The current analyses do not provide surgeons with a method for determining the cost and outcomes of their interventions, which is necessary to the success of bundled payment. Surgeons are ideally positioned to become leaders in ACOs, but in order for them to do so a methodology must be developed where accurate costs and outcomes can be determined for the episode of care.

Novel 3D Hybrid Nanofiber Aerogels Coupled with BMP‐2 Peptides for Cranial Bone Regeneration

An ideal synthetic bone graft is a combination of the porous and nanofibrous structure presented by natural bone tissue as well as osteoinductive biochemical factors such as bone morphogenetic protein 2 (BMP-2). In this work, ultralight 3D hybrid nanofiber aerogels composed of electrospun PLGA-collagen-gelatin and Sr-Cu codoped bioactive glass fibers with incorporation of heptaglutamate E7 domain specific BMP-2 peptides have been developed and evaluated for their potential in cranial bone defect healing. The nanofiber aerogels are surgically implanted into 8 mm × 1 mm (diameter × thickness) critical-sized defects created in rat calvariae. A sustained release of E7-BMP-2 peptide from the degradable hybrid aerogels significantly enhances bone healing and defect closure over 8 weeks in comparison to unfilled defects. Histomorphometry and X-ray microcomputed tomography (µ-CT) analysis reveal greater bone volume and bone formation area in case of the E7-BMP-2 peptide loaded hybrid nanofiber aerogels. Further, histopathology data divulged a near complete nanofiber aerogel degradation along with enhanced vascularization of the regenerated tissue. Together, this study for the first time demonstrates the fabrication of 3D hybrid nanofiber aerogels from 2D electrospun fibers and their loading with therapeutic osteoinductive BMP-2 mimicking peptide for cranial bone tissue regeneration.