Flexor Tendon Repair in Zone II Augmented With an Externalized Detensioning Suture: Protected Flexor Tendon Repair.

Flexor tendon repair in zone II benefits from early finger motion to prevent stiffness. This article presents a technique that serves to augment a zone II flexor tendon repair with an externalized detensioning suture that can be used following any commonly employed repair method. This simple technique enables early active motion and is suited for patients who are less likely to be compliant after surgery or when the soft-tissue injury to the finger and hand is substantial. Although this technique substantially strengthens the repair, a possible drawback is that the tendon excursion distal to the repair is limited until the externalized suture is removed, which may lead to less motion of the distal interphalangeal than what may have occurred without the detensioning suture.

Prospective Cohort Study Comparing Ligament Reconstruction with Tendon Interposition and Suture-Only Suspension Arthroplasty.

BACKGROUND: Basal joint arthritis is a common form of osteoarthritis. There is no consensus procedure for maintenance of trapezial height following trapeziectomy. Suture-only suspension arthroplasty (SSA) is a simple method for stabilizing the thumb metacarpal following trapeziectomy. METHODS: This single-institution, prospective, cohort study compares trapeziectomy followed by either ligament reconstruction with tendon interposition (LRTI) or SSA for the treatment of basal joint arthritis. Patients underwent LRTI or SSA from May of 2018 to December of 2019. Visual analogue scale pain scores; Disabilities of the Arm, Shoulder and Hand questionnaire functional scores; clinical thumb range of motion, pinch, and grip strength data; and patient-reported outcomes were recorded and analyzed preoperatively and at 6 weeks and 6 months postoperatively. RESULTS: Total number of study participants was 45 (LRTI, n = 26; SSA, n = 19). Mean ± SE age was 62.4 ± 1.5 years; 71% were female patients; and 51% underwent surgery on the dominant side. Visual analogue scale scores improved for LRTI and SSA ( P < 0.0001) over 6 months, with no differences between groups at any time point ( P > 0.3). Disabilities of the Arm, Shoulder and Hand questionnaire scores improved for LRTI and SSA over 6 months ( P < 0.0001), with no differences between groups at any time point ( P > 0.3). Following SSA, opposition improved ( P = 0.02), but not as well for LRTI ( P = 0.16). Grip and pinch strength decreased following LRTI and SSA at 6 weeks but recovered similarly for both groups over 6 months. Patient-reported outcomes were generally no different between groups at all time points. CONCLUSION: LRTI and SSA are similar procedures following trapeziectomy relative to pain, function, and strength recovery. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

Radiographic Thumb Metacarpal Subsidence Following Ligament Reconstruction With Tendon Interposition and Suture-Only Suspension Arthroplasty in the Treatment of Basal Joint Arthritis.

BACKGROUND: The thumb carpometacarpal (CMC) joint is a common source of osteoarthritis. Following trapeziectomy, ligament reconstruction with tendon interposition (LRTI) is considered a "gold standard" treatment, but suture-only suspension arthroplasty (SSA) has recently emerged as a simpler alternative. Currently, there is no objective radiographic study comparing subsidence following these 2 techniques. METHODS: This study is a retrospective review of 23 patients (10 LRTI, 13 SSA) that had at least 6 months of radiographic follow-up following thumb CMC arthroplasty. Posteroanterior radiographs at a preoperative timepoint, and at the 2-week and greater than 6-month postoperative timepoints were evaluated for actual trapezial height, as well as trapezial height normalized to capitate, thumb metacarpal, and proximal phalangeal heights. Normalized trapezial heights were calculated, and preoperative values were compared with greater than 6-month postoperative values. In addition, actual and normalized trapezial heights following LRTI and SSA were compared at each timepoint. RESULTS: Mean trapezial height decreased from approximately 12 to 5 mm (reduction of ~60%, P < .05) in both groups with no differences when comparing LRTI and SSA at each timepoint. All normalized trapezial heights revealed differences from preoperative to greater than 6-month postoperative timepoints, but no differences between LRTI and SSA. CONCLUSIONS: Ligament reconstruction with tendon interposition and SSA exhibit equivalent actual and normalized trapezial heights over a greater than 6-month postoperative time course.

Flap Monitoring Using Transcutaneous Oxygen or Carbon Dioxide Measurements.

Free tissue transfer is a cornerstone of complex reconstruction. In many cases, it represents the last option available for a patient and their reconstruction. At high-volume centers, the risk of free flap failure is low but its occurrence can be devastating. Currently, the mainstay for flap monitoring is the clinical examination. Though reliable when performed by experienced clinicians, the flap exam is largely subjective, is performed discontinuously, and often results in significant time delay between detection of flap compromise and intervention. Among emerging flap monitoring technologies, the most promising appear to be those that rely on noninvasive transcutaneous oxygen and carbon dioxide measurements, which provide information regarding flap perfusion. In this article, we review and summarize the literature on various techniques but primarily emphasizing those technologies that rely on transcutaneous gas measurements. We also define characteristics for the ideal flap monitoring tool and discuss critical barriers, predominantly cost, preventing more widespread utilization of adjunct monitoring technologies, and their implications.

Three-dimensional (3D) synthetic printing for the manufacture of non-biodegradable models, tools and implants used in surgery: a review of current methods.

The advent of three-dimensional (3D) printing in the 1980s ushered in a new era of manufacturing. Original 3D printers were large, expensive and difficult to operate, but recent advances in 3D printer technologies have drastically increased the accessibility of these machines such that individual surgical departments can now afford their own 3D printers. As adoption of 3D printing technology has increased within the medical industry so too has the number of 3D printable materials. Selection of the appropriate printer and material for a given application can be a daunting task for any clinician. This review seeks to describe the benefits and drawbacks of different 3D printing technologies and the materials used therein. Commercially available printers using fused deposition modelling or fused filament fabrication technology and relatively inexpensive thermoplastic materials have enabled rapid manufacture of anatomic models and intraoperative tools as well as implant prototyping. Titanium alloys remain the gold-standard material for various implants used in the fixation of craniofacial or extremity fractures, but polymers and ceramics are showing increasing promise for these types of applications. An understanding of these materials and their compatibility with various 3D printers is essential for application of this technology in a healthcare setting.

Consecutive Bilateral Breast Reconstruction Using Stacked Abdominally Based and Posterior Thigh Free Flaps.

BACKGROUND: Multiple perforator flap breast reconstruction is an option that avoids implants in selected patients with minimal donor tissue. The technique addresses the need for additional skin to help create a breast envelope with more natural ptosis and additional volume to help create a body-appropriate breast mound while avoiding serial fat grafting. Using four flaps for the reconstruction of two breasts (bilateral stacked flap reconstruction) has recently become feasible with the advancement of microsurgical techniques, increased experience with alternative perforator flaps, and use of co-surgery. In this article, we describe our early experience with bilateral stacked flap breast reconstruction. METHODS: From January of 2014 to October of 2018, the senior co-surgeons performed 50 consecutive bilateral stacked flap operations at a single institution. All reconstructions were performed in delayed fashion with a mean operative time of 10 hours. Most breasts (94 percent) were reconstructed with a deep inferior epigastric perforator flap combined with a profunda artery perforator flap. Most flap microanastomoses (91.5 percent) were performed directly with internal mammary vessels. The larger of the two flaps was typically placed inferiorly (66 percent), but there was significant inset variability. RESULTS: Of 200 flaps, five were lost (2.5 percent). Seven take-backs were needed for a flap-related concern, which included two negative explorations and a flap salvage. The most common non-flap-related complication was a thigh wound (17 total, eight requiring a procedure). CONCLUSION: The authors' early experience suggests that bilateral stacked flap breast reconstruction is a powerful tool that can be performed with an acceptable microsurgical risk and an acceptable complication profile in highly selected patients. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Systematic Surgical Approach to Alar Base Surgery in Rhinoplasty.

In an era with smartphone photography and social media (specifically, "selfies"), basal view aesthetics is becoming increasingly important. Achieving balance between the nasal base and the remainder of the nose and face while preserving or restoring external valve function are essential to a successful rhinoplasty. Without a systematic approach to the nasal base, it is more difficult to achieve an ideal outcome from both aesthetic and functional standpoints. This article outlines an organized and systematic approach to the nasal base, beginning with comprehensive nasofacial analysis. The authors continue by describing idealized basal view aesthetics and provide a treatment algorithm for common deformities that include alar flaring and a wide nasal base. The authors attempt to provide a comprehensive approach to the treatment of the nasal base by discussing the implications of treating columellar deformities, tip positioning, or alar-columellar discrepancies on the overall aesthetics of the lower third of the nose. Furthermore, technical considerations are given for common surgical maneuvers addressing the alar base to help guide treatment and prevent complications such as poor scarring, notching, nostril asymmetry or stenosis (external valve obstruction), and alar deformities ("parenthesis" or "bowling pin"), to name a few.

Composite Tissue Preservation.

Composite tissue (CT) preservation is important to outcomes after replant or transplant. Since the first limb replant, the mainstay of preservation has been static cold storage with the amputated part being placed in moistened gauze over ice. Historically, the gold-standard in solid organ preservation has been static cold storage with specialized solution, but this has recently evolved in the last few decades to develop technologies such as machine perfusion and even persufflation. This review explores the impact of cooling and oxygenation on CT, summarizes the work done in the area of CT preservation, discusses lessons learned from our experience in solid organ preservation, and proposes future directions.

Comparison of Fracture Location and Extent of Comminution in Isolated Scaphoid Fractures Versus Transscaphoid Fracture-Dislocations.

Background: Isolated scaphoid fractures (ISFs) are common, whereas transscaphoid fracture-dislocations (TSFDs) are not. Scaphoid fracture location and the extent of comminution are factors that affect treatment and outcome. The purpose of this study is to compare the radiographic characteristics of ISFs with TSFDs associated with greater arc injury. Methods: This study is a retrospective review of all ISFs and TSFDs that presented to our institution during a 5-year period. Fracture location (along the long axis of the scaphoid) was calculated by dividing the distance from the proximal pole to the fracture by the entire length of the scaphoid. The extent of comminution was measured in millimeters along the mid-axis of the scaphoid and divided by the entire length of the scaphoid. Results: One-hundred thirty-eight scaphoid fractures in 137 patients were identified. One-hundred twelve fractures (81%) were ISFs, and 26 (19%) were associated with a TSFD. The mean fracture location was more proximal in TSFDs than in ISFs. However, fractures occurred in the distal third of the scaphoid in 12% of ISFs compared with 0% of TSFDs. Nine percent of ISFs demonstrated comminution as compared with 12% of TSFDs. Extent of comminution was 16% and 28% for ISFs and TSFDs, respectively. Conclusion: Scaphoid fractures associated with greater arc injuries are located more proximally and are more comminuted than ISFs, and distal pole fractures rarely occur in the setting of TSFDs. The increased incidence and extent of comminution in TSFDs may be suggestive of a higher energy injury mechanism.

Oxygenation strategies for encapsulated islet and beta cell transplants.

Human allogeneic islet transplantation (ITx) is emerging as a promising treatment option for qualified patients with type 1 diabetes. However, widespread clinical application of allogeneic ITx is hindered by two critical barriers: the need for systemic immunosuppression and the limited supply of human islet tissue. Biocompatible, retrievable immunoisolation devices containing glucose-responsive insulin-secreting tissue may address both critical barriers by enabling the more effective and efficient use of allogeneic islets without immunosuppression in the near-term, and ultimately the use of a cell source with a virtually unlimited supply, such as human stem cell-derived ß-cells or xenogeneic (porcine) islets with minimal or no immunosuppression. However, even though encapsulation methods have been developed and immunoprotection has been successfully tested in small and large animal models and to a limited extent in proof-of-concept clinical studies, the effective use of encapsulation approaches to convincingly and consistently treat diabetes in humans has yet to be demonstrated. There is increasing consensus that inadequate oxygen supply is a major factor limiting their clinical translation and routine implementation. Poor oxygenation negatively affects cell viability and ß-cell function, and the problem is exacerbated with the high-density seeding required for reasonably-sized clinical encapsulation devices. Approaches for enhanced oxygen delivery to encapsulated tissues in implantable devices are therefore being actively developed and tested. This review summarizes fundamental aspects of islet microarchitecture and ß-cell physiology as well as encapsulation approaches highlighting the need for adequate oxygenation; it also evaluates existing and emerging approaches for enhanced oxygen delivery to encapsulation devices, particularly with the advent of ß-cell sources from stem cells that may enable the large-scale application of this approach.

Bioengineered Approach to the Design of a Fat Graft Based on Mathematical Modeling that Predicts Oxygen Delivery.

BACKGROUND: Fat grafting is a common procedure in plastic surgery. A major limitation is unpredictable graft retention, in part caused by inadequate oxygen delivery during the early posttransfer period. METHODS: The authors present a bioengineered approach to the design of a fat graft based on mathematical theory, which can estimate the limitations of oxygen delivery. To simplify the problem, four variables were defined: (1) recipient-site oxygen partial pressure; (2) adipose tissue oxygen permeability; (3) adipose tissue oxygen consumption rate; and (4) fat graft size. Recipient-site oxygen partial pressure and adipose tissue oxygen permeability were estimated from literature, whereas adipose tissue oxygen consumption rate was measured using stirred microchamber technology. Calculations were performed in both spherical and planar geometry to calculate the maximum allowable fat graft size from an oxygen delivery standpoint. RESULTS: As expected, planar geometry is less favorable for oxygenation but represents a realistic configuration for a fat graft. Maximum allowable fat graft thickness is only approximately 1 to 2 mm at external oxygen partial pressures of 10 to 40 mm Hg; any thicker and an anoxic or necrotic core likely develops. Given a reasonably large surface area and assuming several planes of injection, the maximum allowable fat graft volume is tens of milliliters. CONCLUSIONS: A systematic bioengineered approach may help better design a fat graft. Applying principles of mass transfer theory can predict whether a fat graft has a favorable chance of surviving from an oxygen delivery standpoint and can direct the development of strategies for improved fat graft oxygenation.

Oxygen Perfusion (Persufflation) of Human Pancreata Enhances Insulin Secretion and Attenuates Islet Proinflammatory Signaling.

BACKGROUND: All human islets used in research and for the clinical treatment of diabetes are subject to ischemic damage during pancreas procurement, preservation, and islet isolation. A major factor influencing islet function is exposure of pancreata to cold ischemia during unavoidable windows of preservation by static cold storage (SCS). Improved preservation methods may prevent this functional deterioration. In the present study, we investigated whether pancreas preservation by gaseous oxygen perfusion (persufflation) better preserved islet function versus SCS. METHODS: Human pancreata were preserved by SCS or by persufflation in combination with SCS. Islets were subsequently isolated, and preparations in each group matched for SCS or total preservation time were compared using dynamic glucose-stimulated insulin secretion as a measure of ß-cell function and RNA sequencing to elucidate transcriptomic changes. RESULTS: Persufflated pancreata had reduced SCS time, which resulted in islets with higher glucose-stimulated insulin secretion compared to islets from SCS only pancreata. RNA sequencing of islets from persufflated pancreata identified reduced inflammatory and greater metabolic gene expression, consistent with expectations of reducing cold ischemic exposure. Portions of these transcriptional responses were not associated with time spent in SCS and were attributable to pancreatic reoxygenation. Furthermore, persufflation extended the total preservation time by 50% without any detectable decline in islet function or viability. CONCLUSIONS: These data demonstrate that pancreas preservation by persufflation rather than SCS before islet isolation reduces inflammatory responses and promotes metabolic pathways in human islets, which results in improved ß cell function.

Three-Dimensional Printing in Rhinoplasty.

Rhinoplasty is considered one of the most challenging procedures in plastic surgery. The authors introduce a novel concept of translating three-dimensional photographic images into three-dimensionally-printed, patient-specific, life-size models that can be used in preoperative counseling or as an intraoperative reference during rhinoplasty. This article describes the authors' experience with this new application for three-dimensional printing, a technology that is overall garnering more widespread use and has prospective clinical and research applications in aesthetic surgery.

Characterization of Adipose Tissue Product Quality Using Measurements of Oxygen Consumption Rate.

BACKGROUND: Fat grafting is a common procedure in plastic surgery but associated with unpredictable graft retention. Adipose tissue (AT) "product" quality is affected by the methods used for harvest, processing and transfer, which vary widely amongst surgeons. Currently, there is no method available to accurately assess the quality of AT. OBJECTIVES: In this study, we present a novel method for the assessment of AT product quality through direct measurements of oxygen consumption rate (OCR). OCR has exhibited potential in predicting outcomes following pancreatic islet transplant. Our study aim was to reapportion existing technology for its use with AT preparations and to confirm that these measurements are feasible. METHODS: OCR was successfully measured for en bloc and postprocessed AT using a stirred microchamber system. OCR was then normalized to DNA content (OCR/DNA), which represents the AT product quality. RESULTS: Mean (±SE) OCR/DNA values for fresh en bloc and post-processed AT were 149.8 (± 9.1) and 61.1 (± 6.1) nmol/min/mg DNA, respectively. These preliminary data suggest that: (1) OCR and OCR/DNA measurements of AT harvested using conventional protocol are feasible; and (2) standard AT processing results in a decrease in overall AT product quality. CONCLUSIONS: OCR measurements of AT using existing technology can be done and enables accurate, real-time, quantitative assessment of the quality of AT product prior to transfer. The availability and further validation of this type of assay could enable optimization of fat grafting protocol by providing a tool for the more detailed study of procedural variables that affect AT product quality.