Return to Play in Youth Athletes: Role of the Radiologist with Focus on the Upper Extremity.

Increase in youth sports participation, longer duration of play, and earlier starting points have increased the prevalence of acute and repetitive overuse musculoskeletal injuries. This rise in injury rates has led to increased efforts to better understand the susceptible sites of injury that are unique to the growing immature skeleton. Upper extremity injuries are currently the best studied, particularly those that occur among pediatric baseball players and gymnasts. The weak link in skeletally immature athletes is the growth plate complex that includes those injuries located at the epiphyseal and apophyseal primary physes and the peripherally located secondary physes. This article reviews the anatomy and function of these growth plate complexes, followed by a discussion of the pathophysiologic mechanisms, spectrum of imaging findings, and existing evidence-based guidelines for injury prevention and return to play.

Improving Skin Paddle Reliability and Muscle Gliding in Free Functional Gracilis Transfers.

Free functional muscle transfer is an attractive option within reconstructive surgery when seeking to restore critical muscle function. The gracilis muscle has long been utilized for this purpose due to its expendability and consistent anatomy. Historically, survival of the skin overlying the distal one-third of the myocutaneous gracilis flap has been unpredictable. To address this, the myofasciocutaneous technique was developed, with prior studies demonstrating improved distal skin paddle viability with this approach; however, the mechanism is poorly defined. This study aimed to understand what factors contribute to survival benefit in myofasciocutaneous gracilis flaps. Using cadaveric dissections followed by latex dye injections, we discuss the creation of a deep fascial sheath that contains a rich vascular network and permits adhesion-free excursion at the recipient site. This study advances our understanding of the myofasciocutaneous gracilis flap and provides wider clinical applicability in free functional muscle transfer.

Physeal Fractures of the Distal Ulna: Incidence and Risk Factors for Premature Growth Arrest.

BACKGROUND: The aim of this study is to assess the rate of distal ulnar growth arrest following physeal fracture and to identify specific risk factors for premature physeal closure. METHODS: A retrospective review of patients with a distal ulnar physeal fracture was performed at a single United States children's hospital. Patients without 6-month follow-up were excluded. Patient demographics, injury characteristics, treatment, and outcomes were abstracted. Fractures were classified by the Salter-Harris (SH) system. All follow-up radiographs were reviewed for changes in ulnar variance or signs of premature physeal arrest. RESULTS: Fifty-six children with distal ulnar physeal fracture at a mean age of 10.7±3.3 years were included with a mean follow-up of 1.9 years. The most common fracture pattern was a SH II (52.7%), versus SH I (29.1%), SH III (9.1%), and SH IV (9.1%). Of displaced fractures (41.1%), the mean translation was 40.2±38.3% the and mean angulation was 24.8±20.9 degrees. Eleven fractures (19.6%) demonstrated radiographic signs of growth disturbance, including 3 patients (5.4%) with growth disturbance but continued longitudinal growth and 8 patients (14.3%) with complete growth arrest. The average ulnar variance was -3.4 mm. Three patients underwent subsequent surgical reconstruction including ulnar lengthening with an external fixator, distal ulna completion epiphysiodesis with distal radius epiphysiodesis, and ulnar corrective osteotomy. Patients with displaced fractures and SH III/IV fractures were more likely to develop a growth disturbance (34.8% vs. 3.2%, P =0.003; 50.0% vs. 11.1%, P =0.012, respectively). Children with less than 2 years of skeletal growth remaining at the time of injury had a higher risk of growth disturbance (46.2% vs. 9.5%, P =0.007). CONCLUSIONS: SH III and IV fractures are more common injury patterns in the distal ulna compared with the distal radius. Growth disturbance or growth arrest occurs in ~20% of distal ulnar physeal fractures. Displaced fractures, intra-articular fractures, fractures requiring open reduction, and older children are at increased risk of distal ulnar growth arrest and should be followed more closely. LEVEL OF EVIDENCE: Level IV--case series.

Clinical and operative risk factors for complications after Apert hand syndactyly reconstruction.

This study evaluated how Apert hand syndactyly presentations and reconstructive techniques influence reconstruction outcomes. All cases at a major paediatric hospital between 2007 and 2022 were analysed, including 98 web space reconstructions in 17 patients. Overall, 62% of hands developed complications and 15% required revision surgery. Upton hand type was significantly associated with postoperative complication incidence, specifically including range-of-motion deficits, flexion contracture, web creep and revision surgery. More severe syndactylies may benefit from additional measures to reduce complications. Rectangular commissural flaps showed 1.9 times greater complication risk than interdigitating triangular flaps, including 11.2 times greater risk of web creep. Zigzag volar finger flaps showed 1.8 times greater complication risk than straight-line incisions, including 3.8 times greater risk of web creep. Our study showed that interdigitating triangular commissural flaps and straight-line volar finger incisions are preferable to rectangular commissural and zigzag finger flaps in most cases of Apert hand syndactyly to minimize complications. LEVEL OF EVIDENCE: III.

Wrist Level Tendon Repairs Utilizing a Novel Tendon Stapler Device: An Efficiency and Biomechanical Study.

BACKGROUND: A novel tendon stapler device (TSD) was recently developed and FDA-approved to improve the strength and consistency of primary tendon repairs. We hypothesized this TSD would demonstrate faster and superior biomechanical properties compared to a standard suture coaptation. We also hypothesized that the TSD biomechanical properties would be consistent across participants with differing tendon repair experience. METHODS: Participants included a novice, intermediate, and expert in tendon repairs. Timed comparisons were performed in flexor zones IV-V and extensor zones VI-VII on human cadaver arms. Suture repairs were performed with a modified Kessler with a horizontal mattress. TSD repairs were performed on the matched donor arms. Biomechanical testing included 2-mm gap force, ultimate failure load, and mode of failure. RESULTS: In total, 228 tendon coaptations from 12 donor arms were performed and analyzed. TSD coaptations were three times faster and withstood nearly 50% higher forces on the 2-mm gap testing and roughly 30% higher forces on ultimate failure testing. These findings did not change when the repair times were analyzed by individual participants. The suture coaptations failed from suture pull-through, suture breakage, and knot failure. The TSD coaptation failures only occurred from device pull-through. CONCLUSION: The TSD produces significantly faster and stronger primary tendon coaptations compared to a standard 4-strand core suture repair in human donor arms. These findings also demonstrated minimal variability among participants with differing tendon repair experience. Although further investigation is needed, this device has potential to revolutionize tendon repairs.

Learning Curve of Wrist-level Tendon Repairs Using a Novel Tendon Stapler versus Traditional Suture Methods.

Numerous effective techniques for primary tendon coaptations exist. However, these techniques are complex and require a substantial amount of training to become proficient. Recently, a novel tendon stapler device (TSD) was developed that could potentially diminish the discrepancies among surgeons of varying levels of training. We hypothesized that the TSD would be easier to learn and would demonstrate improved learning curve efficiencies across participants of differing tendon repair experience compared with traditional suture methods. Participants included a novice, intermediate, and expert in tendon repairs. Comparisons were performed on wrist-level flexors and extensors from human donor arms. The suture repairs were performed with a modified Kessler with a horizontal mattress and were performed in one session on two donor arms by each participant. In a second session, each participant performed the TSD repairs on the matched, contralateral donor arms. Scatterplots fitted with Loess curves, one-way analysis of variance, Tukey pairwise comparisons, two-sided independent samples t test, and Fisher exact test were used to analyze findings. Results of our study showed that TSD repair times did not vary significantly by experience level. Suture repairs reached a stable "learned" level around repair #30, whereas the TSD repairs showed a more efficient curve that stabilized around repair #23. The TSD required less educational time, demonstrated a more efficient learning curve, and showed less variability across participants and repair order. Overall, the TSD is easy to adopt and may carry positive implications for surgeons and patients.

Recent Advancements in the Diagnosis and Treatment of Congenital Hand Differences.

Congenital hand and upper limb differences include a wide spectrum of structural abnormalities that affect functional, appearance, and psychosocial domains of affected children. Ongoing advances in the understanding and treatment of these differences continue to shape management. Over the past 10 years, new developments have been made in areas of molecular genetics, noninvasive treatments, surgical techniques, and outcome measures in several commonly seen congenital hand differences. Applying these advances in knowledge and management of congenital hand differences will enable surgeons to achieve the best outcomes possible for these children.

Expanding Indications of the Medial Femoral Condyle Free Flap: Systematic Review in Head and Neck Reconstruction.

The medial femoral condyle free flap serves as an attractive reconstructive option for small- to intermediate-sized bony defects. It is commonly applied in the extremities with limited reports in the head and neck. Methods: A systematic review of the literature was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results: Seventeen articles met inclusion criteria, yielding 166 cases for analysis, with a majority of the cohort from a single study (n = 107; 64.4%). However, all included studies represented novel reconstructive sites and surgical indications. Flap components were described in 157 cases; periosteum was used only in four cases (2.5%), whereas all others are composed of cortical bone combined with periosteum, cancellous bone, and/or cartilage (97.5%). Additionally, a skin island was used in 43 cases (25.9%). Flap measurements were reported in 51 cases, averaging 4.5 ± 2.7 cm in length. Seven cases listed skin island dimensions, averaging 20.2 ± 12.8 cm2. The descending genicular artery was the primary pedicle employed (n = 162; 97.6%), while the superior medial genicular was used in the descending genicular artery's absence (n = 4; 2.4%). Descending genicular artery pedicle length from 15 reporting cases averaged 6.4 ± 1.2 cm. Successful reconstructions totaled 160 cases (96.4%). Recipient complications were seen in 16 cases (9.6%) with six constituting flap failures (3.6%). Donor site complications were minimal (n = 6; 3.6%); however, this included one major complication of femoral shaft fracture. Conclusion: The medial femoral condyle free flap is an effective reconstructive option for the head and neck due to its versatile nature, low complication profile at both recipient and donor site, ease of harvest, and two-team approach.

An Evolution of the Surgical Management of Synpolydactyly: A Case Series of 21 Hands.

INTRODUCTION: Synpolydactyly is a rare congenital anomaly characterized by syndactyly and polydactyly in the central hand. Limited treatment guidelines exist for this complex condition. METHODS: A retrospective review of synpolydactyly patients was conducted at a large, tertiary pediatric referral center to describe our surgical experience and evolution of management. The Wall classification system was used to categorize cases. RESULTS: Eleven patients (21 hands) with synpolydactyly were identified. Most of the patients were White and had at least one first-degree relative who also had synpolydactyly. The Wall classification yielded the following results: 7 type 1A hands, 4 type 2B hands, 6 type 3 hands, and 4 uncategorizable hands. Each patient had an average of 2.6 surgeries and an average follow-up time of 5.2 years. The rates of postoperative angulation and flexion deformities were 24% and 38%, respectively, with many of these cases also demonstrating preoperative alignment abnormalities. These cases often required additional surgeries including osteotomies, capsulectomies, and/or soft tissue releases. The rate of web creep was 14% with 2 of these patients requiring revision surgery. Despite these findings, at the time of final follow-up, most patients had favorable functional outcomes, were able to engage in bimanual tasks, and were able to perform activities of daily living independently. CONCLUSIONS: Synpolydactyly is a rare congenital hand anomaly with a significant degree of variability in clinical presentation. The rates of angulation and flexion deformities as well as web creep are not insignificant. We have learned to prioritize correcting contractures, angulation deformities, and skin fusion, over simply trying to delete the "extra" number of bones as this may destabilize the digit(s).

Does Irreducibility Always Mean a Complex Dislocation? An Analysis of 33 Pediatric Metacarpophalangeal Joint Dislocations.

BACKGROUND: Previous failed reduction and certain radiographic indicators historically have been used to differentiate simple and complex metacarpophalangeal joint (MPJ) dislocations in children, the latter of which warrants open reduction. This investigation aimed to determine the necessity for open reduction with these indicators and establish a new treatment algorithm and educational focus for these rare injuries. METHODS: A 12-year retrospective study was conducted on all children with MPJ dislocations at a single pediatric hospital. The rates of successful closed reduction, number of reduction attempts, and radiographic findings were detailed. Operative details and postoperative outcomes were also gathered. RESULTS: Thirty-three patients with a mean age of 11.1 years were included. Most were male [ n = 27 (82%)] and had undergone two or more previous reduction attempts at an outside facility. Stable closed reduction was then achieved outside of the operating room in five patients and in the operating room under general anesthesia in another 14, for a total of 19 of 33 patients (57.6%). The thumb was injured most often [ n = 19 (57.6%)] and more likely to undergo successful closed reduction ( P = 0.04). There was no relationship between number of previous reduction attempts and ability to achieve closed reduction ( P = 0.72). Neither joint-space widening nor proximal phalanx bayonetting was correlated radiographically with failure of closed reduction ( P = 0.22 and P = 1, respectively). CONCLUSIONS: This study supports closed reduction of pediatric MPJ dislocations in the operating room under general anesthesia before conversion to open reduction, regardless of injury characteristics or previous reduction attempts. This strategy is likely to limit unnecessary open surgery and related risks. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, IV.

A New Source of Mutilating Hand Injuries: The Side-by-Side Utility Terrain Vehicle.

BACKGROUND: Rates of mutilating hand injuries are increasing from accidents caused by all-terrain vehicles (ATVs) and the recently popularized side-by-side utility terrain vehicles (UTVs). Increasing surgeon familiarity with upper extremity (UE) injury patterns, severity, and outcomes following ATV and UTV accidents may improve patient care and advocacy. METHODS: Retrospective comparisons of UE injury patterns, severity, hospital and intensive care unit (ICU) admission lengths, and number of operations were made between ATVs and UTVs. Findings were analyzed with Fisher exact tests, multivariate analysis of variance, analyses of variance with post hoc analyses, and multiple linear regressions. RESULTS: A total of 154 cases were identified for inclusion (ATV, n = 87; UTV, n = 67). Patient ages ranged from 4 to 89 years. The UTV group contained significantly more hand and finger injuries, and more of the fractures were open ( P = 0.005, P < 0.001, and P < 0.001, respectively). Riders of UTVs had nearly three times as many mutilating hand injuries and a nearly ninefold increase in amputations compared with ATV riders ( P < 0.001 and P < 0.001, respectively). On average, the UTV group spent 2.5 additional days in the hospital, 0.91 additional days in an ICU, and had 1.3 additional operations ( P = 0.001, P = 0.007, and P < 0.001, respectively). Vehicle type was the only variable significantly correlated with days in the hospital, ICU, and number of UE operations ( P = 0.002, P = 0.008, and P < 0.001, respectively). CONCLUSIONS: Hand surgeons are in a unique position to serve as forerunners for increasing public awareness of off-road vehicle risks and promoting rider safety. Collaborating with manufacturers and emergency care providers and directing teaching initiatives may improve patient outcomes. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, II.

The BREASTrial Stage III: Acellular Dermal Matrix Breast Reconstruction Outcomes from 3 Months to 2 Years Postoperatively.

BACKGROUND: The Breast Reconstruction Evaluation of Acellular Dermal Matrix as a Sling Trial (BREASTrial) is a blinded, randomized trial comparing the outcomes of tissue expander breast reconstruction using AlloDerm or DermaMatrix. In this final stage of the trial, outcomes 3 months to 2 years after definitive reconstruction are reported along with patient satisfaction data. METHODS: A randomized trial was conducted to compare complication rates between groups of patients who underwent reconstruction with AlloDerm and DermaMatrix. Regression models were used to analyze the impact of matrix type, age, chemotherapy, radiation therapy, and reconstructive type on complication rates. Premastectomy and postmastectomy questionnaires were used to assess patient satisfaction and were also analyzed using regression models. RESULTS: Of the 128 patients (199 breasts) who were randomized in the trial, 108 patients (167 breasts) were available for analysis in stage III. There was no difference in the overall complication rates between the AlloDerm and DermaMatrix groups (6% versus 13.2%; P = 0.3) or the severity of those complications ( P = 0.7). Obesity was a positive predictor for complications, regardless of reconstruction group ( P = 0.02). Patient satisfaction was positive overall and did not grossly vary between AlloDerm and DermaMatrix groups. CONCLUSIONS: Findings from the BREASTrial conclude that AlloDerm and DermaMatrix exhibit similar histologic and clinical outcomes. Patient satisfaction is also similar between matrices. Obesity is a predictor of complications, and acellular dermal matrices should be used with caution in these patients. As the largest head-to-head trial comparing two acellular dermal matrices, the BREASTrial contributes to the fund of knowledge regarding acellular dermal matrix supplementation in breast reconstruction. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

Alternative Tendon Coaptations to the Pulvertaft Weave Technique: A Systematic Review and Meta-Analysis of Biomechanical Studies.

BACKGROUND: The Pulvertaft weave technique (PT) is frequently used during tendon repairs and transfers. However, this technique is associated with limitations. In this systematic review and meta-analysis, quantitative and qualitative analyses were performed on in vitro, biomechanical studies that compared the PT with alternative techniques. METHODS: Articles included for qualitative and/or qualitative analysis were identified following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies included in the meta-analysis were analyzed either as continuous data with inverse variance and random effects or as dichotomous data using a Mantel-Haenszel analysis assuming random effects to calculate an odds ratio. RESULTS: A comprehensive electronic search yielded 8 studies meeting inclusion criteria for meta-analysis. Two studies with a total of 65 tendon coaptations demonstrated no significant difference in strength between the PT and traditional side-to-side (STS) techniques (P = .92). Two studies with a total of 43 tendon coaptations showed that the STS with 1 weave has a higher yield strength than the PT (P = .03). Two studies with a total of 62 tendon repairs demonstrated no significant difference in strength between the PT and the step-cut (SC) techniques (P = .70). The final 2 studies included 46 tendon repairs and demonstrated that the wrap around (WA) technique has a higher yield strength than the PT (P < .001). CONCLUSIONS: The STS, SC, and WA techniques are preferred for improving tendon form. The STS and WA techniques have superior yield strengths than the PT, and the SC technique withstands similar stress to failure as the PT.

Hand Surgeons' Understanding of Partial Hand Prostheses: Results of a National Survey Study.

PURPOSE: Partial hand amputations are devastating injuries that often negatively affect individuals and communities. Partial hand prostheses can mitigate the burdens of living with an amputation, especially when reconstruction alone cannot restore form or function. However, hand surgeons may be unfamiliar with these newer devices because the prosthetic field is rapidly progressing. METHODS: An electronic survey was distributed to hand surgeon members of the American Association for Hand Surgery with the intent of assessing surgeons' familiarity with partial hand prosthetic devices and their clinical applications. Survey items used Likert 5-point scales, rank order, multiple-choice, and yes/no question formats. Responses were compared by training background (orthopedic or plastic surgery) and by years of experience (≤10 years in practice or >10 years in practice). RESULTS: Overall, hand surgeons are unfamiliar with modern partial hand prosthetic devices. Most of the cohort denied working within a multidisciplinary hand team (76.2%) or consulting with a prosthetist prior to revisional surgeries (71.4%). Restoring gross motor function and reducing pain were important outcomes to the cohort (4.42 and 4.17, respectively). Plastic trained hand surgeons were more likely to list toe-to-hand transfers as treatment options for multilevel digital amputations (P = .03) and transmetacarpal amputations (P = .02). Senior hand surgeons were more likely to suggest no treatment for partial thumb amputations (P = .02). CONCLUSIONS: Expanding surgeon knowledge and encouraging collaboration within a multidisciplinary team may enhance amputee care.

Reconstruction of a Near-total Scalp Avulsion with NovoSorb Biodegradable Temporizing Matrix: Pediatric Case Report.

Traumatic dog bites of the face and head are common among the pediatric population, although injuries resulting in total or subtotal scalp avulsions are rare and life-threatening. Standard treatment in these cases includes attempts at replantation or free tissue transfer; however, these procedures may not always be possible. An alternative treatment option involves the use of dermal substitutes, such as Integra (Integra LifeScience Corporation), with subsequent skin grafting. More recently, an alternative skin substitute called NovoSorb Biodegradable Temporizing Matrix (BTM) (PolyNovo North America LLC) has displayed favorable reconstructive outcomes in recent burn literature. NovoSorb BTM is a novel, fully synthetic bilayer scaffold made of biodegradable polyurethane matrix covered with a sealing membrane. In this report, the authors describe a 3-year-old boy who presented emergently with a severe dog bite avulsion to the subpericranial level of approximately 80% of his scalp, which was not replantable. The surgical plan involved a staged reconstruction using Integra and later skin grafting. Purulent infection ensued and required removal of Integra less than 2 weeks from application. Upon clearing of the infection, the wound was successfully closed with BTM and subsequent skin grafting. With proper wound management and over 6 months of follow-up, the patient experienced excellent healing of the graft with stable calvarial coverage and an acceptable aesthetic outcome. He will undergo tissue expansion of the remaining hair-bearing scalp in the future.

Optimizing the Pulvertaft Weave Technique: A Comprehensive Systematic Review of Comparative Biomechanical Studies.

BACKGROUND: The Pulvertaft weave continues as a staple technique for tendon coaptations. Many have proposed minor alterations to the original technique to improve its strength, although a lack of consensus exists. The authors' aim was to explore how the number of weaves and suture characteristics contribute to the overall strength of the coaptation. METHODS: A comprehensive electronic search was conducted using the PubMed, Cochrane Library, and Scopus databases. Criteria for inclusion consisted of cadaveric human or animal biomechanical studies evaluating ultimate failure load (in newtons) and the number of weaves, suture characteristics, tendon source, and number of coaptations. Weaves with minimum averages of 75 N were deemed successful, and those with greater than 120 N were considered high performing. RESULTS: A total of 347 tendon coaptations from 15 studies met inclusion criteria. Average strength by number of weaves was 36.4 N ( n = 52) for one weave, 54.2 N ( n = 58) for two weaves, 115.9 N ( n = 174) for three weaves, and 81.7 N ( n = 63) for four weaves. Statistical differences were observed between one and two weaves ( p < 0.0001); two and three weaves ( p < 0.0001); three and four weaves ( p < 0.003); and two and four weaves ( p < 0.0001). High-performing tendon transfers used three weaves, 3-0 or 4-0 braided sutures, and figure-of-eight or mattress core sutures. CONCLUSIONS: Contrary to the current dogma of "the more the better," the authors' findings show that Pulvertaft weave strength is optimized when three weaves are used to combine donor and recipient tendons. Braided sutures with either figure-of-eight or mattress sutures were associated with the highest strength of repair.

Making the Best of a Bad Situation: Case Report of a Nonreplantable Four-finger Amputation with Flap Coverage and Partial Hand Prosthesis Utilization.

Partial hand amputations (PHAs) are often associated with detriments to self-expression, independence, and employment. Modern partial hand prostheses, coupled with reconstructive surgery, may greatly mitigate the physical, psychological, social, and financial impairments caused by PHAs. The MCPDriver is a body-powered prosthesis and is an example of one of these modern, easy-to-use prostheses. This case report describes a 30-year-old man who experienced a traumatic, nonreplantable four finger degloving amputation of digits 2-5 at the level of the proximal phalanges. Initial reconstruction included preserving the length of the amputated phalanges and using a pedicled groin flap for soft tissue coverage with the goal to ultimately facilitate the use of a partial hand prosthesis. Once the PHA was stable, the multidisciplinary hand team held several discussions to review how to revise the flap for an MCPDriver. Staged debulking surgeries and syndactyly releases facilitated a successful fitting with the prosthesis. The patient resumed employment and bimanual tasks shortly after being fit with the prosthesis. The patient also reported significant improvements in his mental health and in the quality of his social interactions. This case illustrates how reconstructive surgeries coupled with partial hand prosthesis utilization can restore form and function following amputation. Familiarity with the modern classes of upper extremity prostheses and collaborating within a multidisciplinary hand team will likely enhance reconstructive outcomes following traumatic PHAs.

Impact of Chemotherapy and Radiation Therapy on Inflammatory Response, Neovascularization, and Capsule Formation of Acellular Dermal Matrix in Breast Reconstruction: Analysis of the BREASTrial Biopsy Specimens.

BACKGROUND: The Breast Reconstruction Evaluation of Acellular Dermal Matrix as a Sling Trial is a single-center, blinded, prospective, randomized, controlled trial established to compare outcomes using two popular types of acellular dermal matrices, AlloDerm and DermaMatrix, in tissue expander breast reconstruction. This study used the acellular dermal matrix biopsy specimens from the trial to evaluate how adjuvant therapy influences inflammation, neovascularization, and capsule formation of the acellular dermal matrix. METHODS: Punch biopsy specimens were taken at the time of expander exchange and were analyzed by a blinded pathologist. The inflammatory response was quantified by the number of fibroblasts, giant cells, and lymphocytes. Neovascularization and capsule formation were similarly quantified by the number of new capillaries and capsule presence and thickness, respectively. RESULTS: Histology specimens were collected from 109 patients (170 breasts). In the absence of adjuvant therapy, there was no significant difference between AlloDerm and DermaMatrix in terms of inflammation, neovascularization, or capsule thickness. Both acellular dermal matrices showed a significant decrease in inflammation and neovascularization with adjuvant therapy. When chemotherapy and radiation therapy were used, the decrease in inflammation was greatest for the group reconstructed with DermaMatrix (p < 0.039). CONCLUSIONS: Adjuvant therapy influences the inflammatory response, neovascularization, and capsule formation in both acellular dermal matrices. Adjuvant therapy has a protective effect on the inflammatory response toward both acellular dermal matrices in breast reconstruction. In the setting of chemotherapy and radiation therapy, DermaMatrix produced the greatest reduction in inflammation. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

Prevention of Venous Thromboembolism in Microvascular Surgery Patients Using Weight-Based Unfractionated Heparin Infusions.

BACKGROUND: Unfractionated heparin infusions are commonly used in microvascular surgery to prevent microvascular thrombosis. Previously, fixed-dose heparin infusions were believed to provide sufficient venous thromboembolism (VTE) prophylaxis; however, we now know that this practice is inadequate for the majority of patients. Anti-factor Xa (aFXa) level is a measure of unfractionated heparin efficacy and safety. This study evaluated the pharmacodynamics of weight-based dose heparin infusions and the impacts of real-time aFXa-guided heparin dose adjustments. METHODS: This prospective clinical trial enrolled adult microvascular surgery patients who received a weight-based heparin dose following a microsurgical procedure. Steady-state aFXa levels were monitored, and patients with out-of-range levels received dose adjustments. The study outcomes assessed were aFXa levels at a dose of heparin 10 units/kg/hour, time to adequate aFXa level, number of dose adjustments required to reach in-range aFXa levels, and clinically relevant bleeding and VTE at 90 days. RESULTS: Twenty-one patients were prospectively recruited, and usable data were available for twenty patients. Four of twenty patients (20%) had adequate prophylaxis at a heparin dose of 10 units/kg/hour. Among patients who received dose adjustments and achieved in-range aFXa levels, the median number of dose adjustments was 2 and the median weight-based dose was 11 units/kg/hour. The percentage of patients with in-range levels was significantly increased (65 vs. 15%, p = 0.0002) as a result of real-time dose adjustments. The rate of VTE at 90 days was 0%, and clinically relevant bleeding rate at 90 days was 15%. CONCLUSION: Weight-based heparin infusions at a rate of 10 units/kg/hour provide a detectable level of anticoagulation for some patients following microsurgical procedures, but most patients require dose adjustment to ensure adequate VTE prophylaxis.