Infection After Lower-Limb Osseointegration: A Single-Center Retrospective Evaluation of Pathogens, Management, and Outcomes.

PURPOSE: Osseointegration (OI) is a novel alternative to traditional socket-suspended prostheses for lower-limb amputees, eliminating the socket-skin interface and allowing for weight bearing directly on the skeletal system. However, the stoma through which the implant attaches to the external prosthesis creates an ingress route for bacteria, and infection rates as high as 66% have been reported. The aims of this study are to classify infection management and long-term outcomes in this patient population to maximize implant salvage. METHODS: An institutional review board-approved retrospective analysis was performed on all patients who underwent lower-limb OI at our institution between 2017 and 2022. Demographic, operative, and outcome data were collected for all patients. Patients were stratified by the presence and severity of infection. Chi-square and t tests were performed on categorical and continuous data, respectively, using an alpha of 0.05. RESULTS: One hundred two patients met our study criteria; 62 had transfemoral OI and 40 had transtibial OI. Patients were followed for 23.8 months on average (range, 3.5-63.7). Osteomyelitis was more likely than soft tissue infection to be polymicrobial in nature (71% vs 23%, P < 0.05). Infections at the stoma were mostly (96%) managed with oral antibiotics alone, whereas deeper soft tissue infections also required intravenous antibiotics (75%) or operative washout (19%). Osteomyelitis was managed with intravenous antibiotics and required operative attention; 5 (71%) underwent washout and 2 (29%) underwent explantation. Both implants were replaced an average of 3.5 months after explantation. There was no correlation between history of soft tissue infection and development of osteomyelitis (P > 0.05). The overall implant salvage rate after infection was 96%. CONCLUSIONS: This study describes our institution's experience managing infection after OI and soft tissue reconstruction. Although infections do occur, they are easily treatable and rarely require operative intervention. Explantation due to infection is rare and can be followed up with reimplantation, reaffirming that OI is a safe and effective treatment modality.

Comparative Analysis of Recurrence-Free Survival and Mortality in Postmastectomy Patients: Insights From Multidecade, Multiinstitutional Propensity Score Matching.

INTRODUCTION: Disparities in postmastectomy reconstructive care are widely acknowledged. However, there is limited understanding regarding the impact of reconstructive services on cancer recurrence and breast cancer-related mortality. Therefore, this study aims to examine how patient-specific factors and breast reconstruction status influence recurrence-free survival and mortality rates in breast cancer patients. METHODS: Retrospective chart review was performed to collect data on patients who underwent mastectomy at 2 institutions within the New York-Presbyterian system from 1979 to 2019. Sociodemographic information, medical history, and the treatment approach were recorded. Propensity score matching, logistic regression, unpaired t test, and chi-square test were used for statistical analysis. RESULTS: Overall, cancer recurrence occurred in 6.62% (317) of patients, with 16.8% (803) overall mortality rate. For patients who had relapsed disease, completion of the reconstruction sequence was correlated with an earlier detection of cancer recurrence and improved survival odds (P < 0.05). Stratified analysis of the reconstruction group alone showed mortality benefit among patients who underwent free flap procedures (P < 0.05). CONCLUSION: Patients undergoing breast reconstruction after mastectomy are likely to have better access to follow-up care and improved interfacing with the healthcare system. This may increase the speed at which cancer recurrence is detected. This study highlights the need for consistent plastic surgery referral and continued monitoring by all members of the breast cancer care team for cancer recurrence among patients.

Assessing Long-Term Volume Retention in Breast Fat Grafting: A Comparative Study of Lipoaspirate Processing Techniques.

INTRODUCTION: Autologous fat grafting is a method of improving aesthetic outcomes after both breast reconstruction and aesthetic surgery through volume enhancement and tissue contouring. Long-lasting effects are linked to greater patient satisfaction and more optimal augmentation results. Harvesting, processing, and injection techniques may all affect the longevity of deformity filling. Our objective is to evaluate the effect of lipoaspirate processing modality on longitudinal volume retention after surgery. METHODS: A prospective, single-institution, randomized control trial placed consented postmastectomy fat grafting patients into 1 of 3 treatment arms (active filtration, low-pressure decantation, and standard decantation) in a 1:1:1 ratio. A preoperative 3-dimensional scan of the upper torso was taken as baseline. At the 3-month postoperative visit, another 3D scan was taken. Audodesk Meshmixer was used to evaluate the volume change. RESULTS: The volume of fat injected during the initial procedure did not differ significantly between the treatment arms (P > 0.05). Both active filtration and low-pressure decantation resulted in higher percentage volume retention than traditional decantation (P < 0.05). Active filtration and low-pressure decantation exhibited comparable degrees of fat maintenance at 3 months (P > 0.05). DISCUSSION: Compared with using traditional decantation as the lipoaspirate purification technique, active filtration and low-pressure decantation may have led to higher levels of cell viability by way of reduced cellular debris and other inflammatory components that may contribute to tissue resorption and necrosis. Further immunohistochemistry studies are needed to examine whether active filtration and low-pressure decantation lead to lipoaspirates with more concentrated viable adipocytes, progenitor cells, and factors for angiogenesis.

An Evolving Landscape: Return of Breast Sensation After Mastectomy Varies by Anatomic Region and Reconstructive Method.

PURPOSE: Loss of breast sensation after mastectomy has been well documented. Postoperative reinnervation of the breast is influenced by factors including reconstructive technique, patient comorbidities, and adjuvant treatment. However, little attention has been paid to the differences in sensation across regions of the breast and the impact of reconstructive method on these regional differences over time. METHODS: Patients undergoing nipple-sparing mastectomy with immediate autologous or alloplastic reconstruction were prospectively followed. Neurosensory testing was performed in 9 breast regions using a pressure-specified sensory device. Patients were stratified by reconstructive technique, and regional sensation was compared at different preoperative and postoperative time points using Student t tests. RESULTS: One hundred ninety-two patients were included; 106 underwent autologous reconstruction via neurotized deep inferior epigastric artery perforator flap, and 86 underwent 2-stage alloplastic reconstruction. Preoperative sensation thresholds did not differ between reconstructive cohorts in any region and averaged 18.1 g/mm2. In the first year after mastectomy, decreased sensation was most pronounced in the inner breast regions and at the nipple areolar complex (NAC) in both reconstructive cohorts. At 4 years postoperatively, sensation increased the most at the NAC in the alloplastic cohort (34.0 g/mm2 decrease) and at the outer lateral region in the autologous cohort (30.4 g/mm2 threshold decrease). The autologous cohort experienced improved sensation compared with the alloplastic cohort in 5 of 9 regions at 1 year postoperatively, and in 7 of 9 regions at 4 years postoperatively; notably, only sensation at the outer superior and outer medial regions did not differ significantly between cohorts at 4 years postoperatively. CONCLUSIONS: Although patients undergoing breast reconstruction experience increased breast sensation over time, the return of sensation is influenced by type of reconstruction and anatomic region. Regions closer to and at the NAC experience the greatest loss of sensation after mastectomy, although the NAC itself undergoes the most sensation recovery of any breast region in those with alloplastic reconstruction.Autologous reconstruction via a neurotized deep inferior epigastric artery perforator flap results in increased return of sensation compared with alloplastic reconstruction, particularly in the inferior and lateral quadrants of the breast.

Impact of Comorbidities on Sensory Return After Breast Reconstruction.

PURPOSE: Breast anesthesia after mastectomy and reconstruction has been an ongoing concern with few improvements made in recent years. At present, there is a lack of studies evaluating the impact of comorbidities on sensation restoration. Identifying risk factors (RF) will be helpful with preoperative counseling. METHODS: This was a prospective study on patients who underwent mastectomy and immediate implant-based or neurotized deep inferior epigastric perforator (DIEP) flap-based reconstruction. Neurosensory testing was performed at predefined time points using a pressure specified device. Patients were stratified based on reconstruction type and comorbidities, including obesity (≥30 kg/m2), age (>55 years), hypertension, alcohol use, and smoking status. Sensory comparisons among the comorbidity groups were conducted using unpaired 2-sample t tests. RESULTS: A total of 239 patients were included in this study with 109 patients in the implant cohort and 131 patients in the DIEP cohort. One patient underwent bilateral reconstruction using both reconstructive modalities. Preoperatively, age older than 55 years was identified as an RF for reduced breast sensation in the implant cohort (difference in threshold, 10.7 g/mm2), whereas obesity was identified as an RF in the DIEP cohort (difference in threshold, 8 g/mm2). During the first 2 years postreconstruction, age older than 55 years and tobacco use history were found to be negatively correlated with breast sensation for both cohorts. With DIEP reconstruction specifically, obesity was identified as an additional RF during the early postoperative period. Of note, none of the comorbidities were found to be long-term RFs for reduced breast sensitivity. All breast sensation levels returned to comparable levels across all comorbidities by 4 years postreconstruction. CONCLUSIONS: Currently, various comorbidities have been recognized as RFs for several postoperative complications including extended postoperative stay, necrosis, infection, and reoperation. However, our findings suggest that, although age, smoking history, and obesity showed transient associations with reduced breast sensation during the initial years postreconstruction, they play no role in the long-term potential of sensory nerve regeneration.

Proliferation Patterns of MCF-7 Breast Cancer Cells in Lipoaspirate Conditioned Media.

INTRODUCTION: Autologous fat grafting (AFG) is a common technique used to enhance aesthetic outcomes in postmastectomy breast reconstruction patients. Adipokines are hormones secreted by adipose tissue that play a critical role in regulating metabolic processes and the immune system. However, dysregulated adipokine secretion and signaling can contribute to the development and progression of cancer by promoting angiogenesis, altering the immune response, and inducing the epithelial mesenchymal transition. We aimed to assess how breast cancer cells behave in conditioned media derived from fat grafting lipoaspirates and gain a better understanding of the potential interactions that may occur within the tumor microenvironment. METHODS: Patients who were undergoing AFG as a part of breast reconstruction at NY-Presbyterian/Weill Cornell Medical Center between March 2021 and July 2023 were consented and enrolled in the study. This study was approved by the Weill Cornell Medicine Institutional Review Board (#20-10022850-14). Conditioned media is created using 20% of patient lipoaspirate secretome and 80% starving media. The growth of MCF-7, a human ER/PR+ breast cancer cell line, in conditioned media is assessed using CyQUANT. RESULTS: The breast cancer cells incubated in conditioned media displayed similar growth trends as those in complete media, which is enriched for cell growth (P > 0.05). MCF-7 cell behavior in conditioned media differed significantly from their proliferation patterns when serum starved in 100% starving media (P < 0.05). DISCUSSION: Our results suggest that there may be inherent factors within the lipoaspirate that may promote MCF-7 proliferation. One potential implication is that AFG used for breast reconstruction should be delayed until local-regional disease control has been established. In addition, based on the in vitro proliferation patterns of breast cancer cells in conditioned media, the safety profile of AFG may be enhanced if the procedure is performed after attaining negative margins and the completion breast cancer treatment.

Using a Machine Learning Approach to Predict the Need for Elective Revision and Unplanned Surgery after Implant-based Breast Reconstruction.

Two-stage implant-based reconstruction after mastectomy may require secondary revision procedures to treat complications, correct defects, and improve aesthetic outcomes. Patients should be counseled on the possibility of additional procedures during the initial visit, but the likelihood of requiring another procedure is dependent on many patient- and surgeon-specific factors. This study aims to identify patient-specific factors and surgical techniques associated with higher rates of secondary procedures and offer a machine learning model to compute individualized assessments for preoperative counseling. A training set of 209 patients (406 breasts) who underwent two-stage alloplastic reconstruction was created, with 45.57% of breasts (185 of 406) requiring revisional or unplanned surgery. On multivariate analysis, hypertension, no tobacco use, and textured expander use corresponded to lower odds of additional surgery. In contrast, higher initial tissue expander volume, vertical radial incision, and larger nipple-inframammary fold distance conferred higher odds of additional surgery. The neural network model trained on clinically significant variables achieved the highest collective performance metrics, with ROC AUC of 0.74, sensitivity of 84.2, specificity of 63.6, and accuracy of 62.1. The proposed machine learning model trained on a single surgeon's data offers a precise and reliable tool to assess an individual patient's risk of secondary procedures. Machine learning models enable physicians to tailor surgical planning and empower patients to make informed decisions aligned with their lifestyle and preferences. The utilization of this technology is especially applicable to plastic surgery, where outcomes are subject to a variety of patient-specific factors and surgeon practices, including threshold to perform secondary procedures.

Relationships between throwing mechanics and shoulder anterior force in high school and professional baseball pitchers.

Background: Excessive shoulder anterior force has been implicated in pathology of the rotator cuff in little league and professional baseball pitchers; in particular, anterior laxity, posterior stiffness, and glenohumeral joint impingement. Distinctly characterized motions associated with excessive shoulder anterior force remain poorly understood. Methods: High school and professional pitchers were instructed to throw fastballs while being evaluated with 3D motion capture (480 Hz). A supplementary random forest model was designed and implemented to identify the most important features for regressing to shoulder anterior force, with subsequent standardized regression coefficients to quantify directionality. Results: 130 high school pitchers (16.3 ± 1.2 yrs; 179.9 ± 7.7 cm; 74.5 ± 12.0 kg) and 322 professionals (21.9 ± 2.1 yrs; 189.7 ± 5.7 cm; 94.8 ± 9.5 kg) were included. Random forest models determined nearly all the variance for professional pitchers (R2 = 0.96), and less than half for high school pitchers (R2 = 0.41). Important predictors of shoulder anterior force in high school pitchers included: trunk flexion at maximum shoulder external rotation (MER) (X.IncMSE = 2.4, ß = -0.23, p < 0.001), shoulder external rotation at ball release (BR)(X.IncMSE = 1.7, ß = -0.34, p < 0.001), and shoulder abduction at BR (X.IncMSE = 3.1, ß = 0.17, p < 0.001). In professional pitchers, shoulder horizontal adduction at foot contact (FC) was the highest predictor (X.IncMSE = 13.9, ß = 0.50, p < 0.001), followed by shoulder external rotation at FC (X.IncMSE = 3.6, ß = 0.26, p < 0.001), and maximum elbow extension velocity (X.IncMSE = 8.5, ß = 0.19, p < 0.001). Conclusion: A random forest model successfully selected a subset of features that accounted for the majority of variance in shoulder anterior force for professional pitchers; however, less than half of the variance was accounted for in high school pitchers. Temporal and kinematic movements at the shoulder were prominent predictors of shoulder anterior force for both groups. Clinical relevance: : Our statistical model successfully identified a combination of features with the ability to adequately explain the majority of variance in anterior shoulder force among high school and professional pitchers. To minimize shoulder anterior force, high school pitchers should emphasize decreased shoulder abduction at BR, while professionals can decrease shoulder horizontal adduction at FC.

Lymphedema self-assessment among endometrial cancer survivors.

PURPOSE: Lower extremity lymphedema (LEL), which causes ankle, leg, and feet swelling, poses a significant challenge for endometrial cancer survivors, impacting physical functioning and psychological well-being. Inconsistent LEL diagnostic methods result in wide-ranging LEL incidence estimates. METHODS: We calculated the cumulative incidence of LEL based on survivor-reported Gynecologic Cancer Lymphedema Questionnaire (GCLQ) responses in addition to survivor- and nurse-reported leg circumference measurements among a pilot sample of 50 endometrial cancer survivors (27 White, 23 Black) enrolled in the ongoing population-based Carolina Endometrial Cancer Study. RESULTS: Self-leg circumference measurements were perceived to be difficult and were completed by only 17 survivors. Diagnostic accuracy testing measures (sensitivity, specificity, positive and negative predictive value) compared the standard nurse-measured ≥ 10% difference in leg circumference measurements to GCLQ responses. At a mean of ~11 months post-diagnosis, 54% of survivors met established criteria for LEL based on ≥ 4 GCLQ cutpoint while 24% had LEL based on nurse-measurement. Percent agreement, sensitivity, and specificity approximated 60% at a threshold of ≥ 5 GCLQ symptoms. However, Cohen's kappa, a measure of reliability that corrects for agreement by chance, was highest at ≥ 4 GCLQ symptoms (κ = 0.27). CONCLUSION: Our findings emphasize the need for high quality measurements of LEL that are feasible for epidemiologic study designs among endometrial cancer survivors. Future studies should use patient-reported survey measures to assess lymphedema burden and quality of life outcomes among endometrial cancer survivors.

Targeted Nipple Reinnervation in Gender-affirming Mastectomy Using Autologous Nerve Graft.

Our team recently described targeted nipple reinnervation (TNR) during female-to-male gender-affirming mastectomy with free nipple grafting using either direct nerve coaptation or nerve allograft. The goals of TNR are to improve sensation (including erogenous sensation) and prevent numbness, paresthesias, chronic pain, and phantom sensation. Here, we describe our modified technique, which has evolved to use autologous intercostal nerve branches as donor nerves for reinnervation if direct nerve coaptation cannot be achieved. During TNR, the T3-T5 sensory branches are preserved and coapted to the repositioned nipple-areolar complex (NAC). In patients with donor nerves that were not adequate in length to allow for direct coaptation, autologous intercostal nerve branches were not used for coaptation (branches present along the chest wall that would otherwise be lost) or one of the T3-T5 branches were harvested. An end-to-end nerve repair between the autograft and donor nerves was done, and the donor nerve/autograft complex was coapted to the NAC. Targeted muscle reinnervation was performed after autograft harvest to prevent neuroma formation. TNR with intercostal nerve autograft is technically feasible in female-to-male gender-affirming mastectomy with free nipple grafting when direct coaptation is not possible. Chest reinnervation using autologous intercostal nerve branches as donor nerves is another option for reinnervation when the nerves are too short for direct coaptation. Because the collection of long-term data is ongoing, the effectiveness of NAC reinnervation using our technique will be described in a future publication.

Treatment Delay From Onset of Occipital Neuralgia Symptoms to Treatment with Nerve Decompression Surgery: A Prospective Cohort Study.

BACKGROUND: The aim of this study was to a) evaluate the time between onset of occipital neuralgia symptoms and nerve decompression surgery, b) perform a cost comparison analysis between surgical and non-surgical treatment of occipital neuralgia and c) report postoperative results of nerve decompression for occipital neuralgia. METHODS: 1,112 subjects who underwent screening for nerve decompression surgery were evaluated for occipital neuralgia. 367 (33%) patients met the inclusion criteria. Timing of occipital neuralgia symptom onset and pain characteristics were prospectively collected. Cost associated with the non-surgical treatment of occipital neuralgia was calculated for the period between onset of symptoms and surgery. RESULTS: 226 (73%) patients underwent occipital nerve decompression. The average time between onset of occipital neuralgia and surgery was 19 years (7.1-32). Postoperatively, the median number of pain days per month decreased by 17 (0-26, 57%) (p < 0.001), the median pain intensity decreased by 4 (2-8, 44%) (p < 0.001), and median pain duration in hours was reduced by 12 (2-23, 50%) (p < 0.001). The annual mean cost of non-surgical occipital neuralgia treatment was $28,728.82 ($16,419.42-$41,198.41) per patient. The mean cost during the 19-year timeframe prior to surgery was $545,847.75($311,968.90-$782,769.82). CONCLUSION: This study demonstrates that patients suffer from occipital neuralgia for an average of 19 years prior to undergoing surgery. Nerve decompression reduces symptom severity significantly and should be considered earlier in the treatment course of occipital neuralgia that is refractory to conservative treatment to prevent patient morbidity and decrease direct and indirect healthcare costs. IRB REGISTRATION NUMBER & NAME: Weill Cornell Medicine: 23-04025985, Prospective Cohort Study Investigating Long- Term Outcomes After Headache Surgery.The Massachusetts General Hospital: 2012P001527, Correlation of pre-operative pain self-efficacy and post-operative migraine-specific symptoms and disability.

Machine-Learning Prediction of Capsular Contraction after Two-Stage Breast Reconstruction.

Background: Two-stage breast reconstruction is a common technique used to restore preoperative appearance in patients undergoing mastectomy. However, capsular contracture may develop and lead to implant failure and significant morbidity. The objective of this study is to build a machine-learning model that can determine the risk of developing contracture formation after two-stage breast reconstruction. Methods: A total of 209 women (406 samples) were included in the study cohort. Patient characteristics that were readily accessible at the preoperative visit and details pertaining to the surgical approach were used as input data for the machine-learning model. Supervised learning models were assessed using 5-fold cross validation. A neural network model is also evaluated using a 0.8/0.1/0.1 train/validate/test split. Results: Among the subjects, 144 (35.47%) developed capsular contracture. Older age, smaller nipple-inframammary fold distance, retropectoral implant placement, synthetic mesh usage, and postoperative radiation increased the odds of capsular contracture (p < 0.05). The neural network achieved the best performance metrics among the models tested, with a test accuracy of 0.82 and area under receiver operative curve of 0.79. Conclusion: To our knowledge, this is the first study that uses a neural network to predict the development of capsular contraction after two-stage implant-based reconstruction. At the preoperative visit, surgeons may counsel high-risk patients on the potential need for further revisions or guide them toward autologous reconstruction.

Streamlining the Fat: A Systematic Review of Active Closed Wash and Filtration in Autologous Fat Grafting After Breast Reconstruction.

Although fat grafting in breast reconstruction continues to grow in popularity, the optimal technique remains elusive and outcomes are varied. This systematic review of available controlled studies utilizing active closed wash and filtration (ACWF) systems sought to examine differences in fat processing efficiency, aesthetic outcomes, and revision rates. A literature search was performed from inception to February 2022 following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) in Ovid MEDLINE (Wolters Kluwer, Alphen aan den Rijn, the Netherlands), Ovid Embase (Wolters Kluwer), and Cochrane Library (Wiley, Hoboken, NJ). Two independent reviewers screened the studies for eligibility with Covidence software. Bibliographies and citing references from selected articles were screened from Scopus (Elsevier, Amsterdam, the Netherlands). The search identified 3476 citations, with 6 studies included. Three studies demonstrated a significantly higher volume of graftable fat harvested in a significantly lower mean grafting time with ACWF than with their respective controls. With respect to adverse events, 3 studies reported significantly lower incidences of nodule or cyst formation with ACWF with respect to control. Two studies reported a significantly lower incidence of fat necrosis with ACWF vs control, with this trend upheld in 2 additional studies. Three studies reported significantly lower revision rates with ACWF with respect to control. No study reported inferiority with ACWF for any outcome of interest. These data suggest that ACWF systems yield higher fat volumes in less time than other common techniques, with decreased rates of suboptimal outcomes and revisions, thereby supporting active filtration as a safe and efficacious means of fat processing that may reduce operative times. Further large-scale, randomized trials are needed to definitively demonstrate the above trends.

An Evaluation of Native Breast Dimension and Tissue Expander Inflation Rate on the Risk of Capsular Contracture Development in Postmastectomy Reconstruction.

INTRODUCTION: Capsular contracture is a common complication after 2-stage breast reconstruction. The relationships between native breast size, the rate of tissue expander expansion, and capsule formation have not been elucidated. This study aims to evaluate how these factors contribute to capsular contracture and establish cutoff values for increased risk. METHODS: A data set consisting of 229 patients who underwent 2-stage breast reconstruction between 2012 and 2021 was included in the study. The rate of expansion is estimated as the final expanded volume subtracted by the initial filling volume of the tissue expander over time elapsed. The native breast size was estimated using various preoperative breast measurements and the weight of mastectomy specimen (grams). Further stratified analysis evaluated patients separately based on postoperative radiation status. RESULTS: Greater nipple-inframammary fold distance and faster tissue expander enlargement rate conferred decreased odds of developing capsular contracture ( P < 0.05). On stratified analysis, faster tissue expansion rate was not significant in the nonradiated cohort but remained a significant negative predictor in the radiation group (odds ratio, 0.996; P < 0.05). Cut-point analysis showed an expansion rate of <240 mL/mo and a nipple-inframammary fold value of <10.5 cm as conferring a greater risk of capsular contracture. CONCLUSION: Smaller inframammary fold distance may be associated with a higher risk of capsular contracture. Slower expansion rates correlate with increased odds of contracture in patients undergoing adjuvant radiation. Breast geometry should be considered when risk stratifying various reconstruction approaches (implant vs autologous). In addition, longer delays between implant exchange and initial tissue expansion should be avoided if clinically feasible.

Timeline and Incidence of Postoperative Complications in Prepectoral, Dual-Plane, and Total Submuscular Alloplastic Reconstruction With and Without Biosynthetic Scaffold Usage.

INTRODUCTION: Acellular dermal matrices and synthetic meshes are commonly used to improve inframammary-fold definition, minimize muscle excision, and allow for greater control over the surgical technique in implant-based breast reconstruction. The aims of this study are to compare various combinations of placement planes and biosynthetic scaffolds and to further examine the respective incidences of postoperative complications and the timeline of capsular contracture development. METHODS: A data set consisting of 220 patients (393 samples) who underwent 2-stage reconstruction between 2012 and 2021 was used in the study. χ 2 , Fisher exact test, and 1-way analysis of variance were used to identify significant differences between the 4 subgroups. Cox proportional-hazards model and Kaplan-Meier estimator were used for survival analysis. RESULTS: On univariate logistic regression (odds ratio, 0.21; P = 0.005), survival analysis ( P = 0.0082), and Cox-proportional hazard model (hazard ratio, 1.6; P = 0.01), poly-4-hydroxybutyrate mesh usage was linked to an increased risk of capsular contracture development. Prepectoral placement with no mesh and dual-plane placement with acellular dermal matrix showed similar timelines of capsular contracture development. The lowest incidences of capsular contracture occurred in the prepectoral placement and no mesh (49/161, 30.4%) and total submuscular subgroups (3/14, 21.4%). Infection, necrosis, and revision surgery rates did not differ significantly between the 4 groups. CONCLUSIONS: The use of poly-4-hydroxybutyrate mesh in 2-stage breast reconstruction is correlated with a statistically significant increase in capsular contracture. Prepectoral placement with no biosynthetic scaffold had one of the lowest rates of contracture and may provide the most optimal balance between economic and clinical considerations in implant-based reconstruction.

Osseointegration for Lower Limb Amputation: Understanding the Risk Factors and Time Courses of Soft Tissue Complications.

PURPOSE: Lower-limb osseointegrated prostheses are a novel alternative to traditional socket-suspended prostheses, which are often associated with poor fit, soft tissue damage, and pain. Osseointegration eliminates the socket-skin interface and allows for weight-bearing directly on the skeletal system. However, these prostheses can also be complicated by postoperative issues that can negatively impact mobility and quality of life. Little is known about the incidence of or risk factors for these complications as few centers currently perform the procedure. METHODS: A retrospective analysis was performed on all patients who underwent single-stage lower limb osseointegration at our institution between 2017 and 2021. Patient demographics, medical history, operative data, and outcomes were collected. Fisher exact test and unpaired t tests were performed to identify risk factors for each adverse outcome, and time-to-event survival curves were generated. RESULTS: Sixty patients met our study criteria: 42 males and 18 females with 35 transfemoral and 25 transtibial amputations. The cohort had an average age of 48 years (range, 25-70 years) and follow-up period of 22 months (range, 6-47 months). Indications for amputation were trauma (50), prior surgical complication (5), cancer (4), and infection (1). Postoperatively, 25 patients developed soft tissue infections, 5 developed osteomyelitis, 6 had symptomatic neuromas, and 7 required soft tissue revisions. Soft tissue infections were positively correlated with obesity and female sex. Neuroma development was associated with increased age at osseointegration. Neuromas and osteomyelitis were both associated with decreased center experience. Subgroup analysis by amputation etiology and anatomic location did not show significant differences in outcomes. Notably, hypertension (15), tobacco use (27), and prior site infection (23) did not correlate with worse outcomes. Forty-seven percent of soft tissue infections occurred in the 1 month after implantation, and 76% occurred in the first 4 months. CONCLUSIONS: These data provide preliminary insights into risk factors for postoperative complications arising from lower limb osseointegration. These factors are both modifiable (body mass index, center experience), and unmodifiable (sex, age). As this procedure continues to expand in popularity, such results are necessary to inform best practice guidelines and optimize outcomes. Further prospective studies are needed to confirm the above trends.

Osseointegration for Lower-Extremity Amputees: Operative Considerations from the Plastic Surgeon's Perspective.

➢: Osseointegration for lower-extremity amputees, while increasing in frequency, remains in its relative infancy compared with traditional socket-based prostheses. ➢: Ideal candidates for osseointegration have documented failure of a traditional prosthesis and should be skeletally mature, have adequate bone stock, demonstrate an ability to adhere to a longitudinal rehabilitation protocol, and be in an otherwise good state of health. ➢: Lowering the reoperation rate for soft-tissue complications depends heavily on surgical technique and on the implant device itself; the current gold standard involves a smooth implant surface for dermal contact as well as maximal skin resection to prevent skin breakdown against the prosthesis. This may include the need for thighplasty to optimize skin reduction. ➢: Interdisciplinary peripheral nerve management, such as targeted muscle reinnervation, performed in tandem with a plastic surgery team can treat existing and prevent future symptomatic neuromas, ultimately improving pain outcomes.

A Cost-Benefit Analysis of Osseointegrated Prostheses for Lower Limb Amputees in the US Health Care System.

BACKGROUND: Patients with transfemoral and transtibial amputations generally rely on socket-suspended (SS) prostheses for ambulation. The use of these aids can be complicated by poor fit, leading to tissue damage, pain at the socket-limb interface, and inability to ambulate. Osseointegrated implants (OIs) directly anchor a prosthesis to the patient's residual limb, eliminating these issues. However, they require customized components and additional surgeries. The purpose of this study was to conduct the first cost-benefit analysis of OI prostheses compared to SS prostheses for lower limb amputees in the United States. METHODS: A retrospective chart review was performed on all patients who received unilateral lower limb OI prostheses at our institution. Costs were calculated in a bottom-up approach using Current Procedural Terminology codes. Utilities and SS prosthesis costs were derived from previous studies. A Monte Carlo model was used to project costs and lifetime quality-adjusted life years for OI and SS prostheses, and the incremental cost-effectiveness ratio (ICER) of OI compared SS prostheses was determined. RESULTS: Twenty-five patients (12 female) were included in the study. The mean follow-up was 17 months postimplantation. The average cost of OI surgery was $54,463. Twenty percent of patients required preimplantation soft tissue revision surgery ($49,191). Complication rates per year and average costs were as follows: soft tissue infection (29%, $435), bone/implant infection (11%, $11,721), neuroma development (14%, $14,659), and mechanical failure (17%, $46,513). The ICER was $44,660. A cost-effectiveness acceptability curve demonstrated that OI was favored over SS in 78% of cases at a willingness-to-pay of $100,000 per quality-adjusted life year. In a 1-way sensitivity analysis, the ICER was most sensitive to the mechanical failure rate, mechanical failure cost, and prior SS prosthesis costs. CONCLUSIONS: The model shows that OI prostheses provide a higher quality of life at affordable costs when compared to poorly tolerated SS prostheses in patients with lower limb amputations in the United States. The cost-effectiveness is largely determined by the patient's previous SS prosthesis costs and is limited by the frequency and costs of OI mechanical failure. More research must be done to understand the long-term benefits and risks of OI prostheses.

Kinematic and kinetic analyses of professional pitchers with history of core or groin injuries: A propensity-score matched analysis.

Background: Core injuries in professional baseball pitchers have been linked to both diminished performance and time missed during the season injury was sustained. It is currently unclear how a history of a core injury may affect the future pitching performance and mechanics of professional baseball pitchers. Purpose: To compare kinetic and kinematic variables between professional baseball pitchers with prior core/groin injuries and those without prior injury. Study design: Descriptive laboratory study. Methods: Professional baseball pitchers with a history of core injury pitched 8-12 fastball pitches while evaluated with 3D-motion capture (480 Hz). Inclusion criteria necessitated that the core injury occurred within one to four-years prior to biomechanical evaluation and that the core injury required time off from professional play for a minimum of 2 weeks and maximum of 3 months. These pitchers were 4:1 propensity-scored matched by age, height, weight, and handedness to pitchers with no prior injury history (control). Twenty kinematic and eleven normalized and non-normalized kinetic parameters were compared between groups using appropriate parametric testing. Sub-analysis of pitchers with distinct core muscle and spinal injuries were also analyzed. Results: The No Prior Injury (NPI) subgroup (n = 76) had significantly less elbow flexion at ball release (31 ± 5° vs. 35 ± 6° respectfully, p = 0.044) compared to the Core Musculature/Soft Tissue subgroup (CM/ST, n = 10), with no significant difference in kinematics for other injury groups (p > 0.05). The General Core/Groin injury group (GCG, n = 19) had significantly greater normalized elbow anterior force (43.9 ± 4.7 vs. 40.0 ± 5.2 %BodyWeight[BW], p = 0.006) and elbow flexion torque (4.3 ± 0.5 vs. 3.8 ± 0.5 %BWxBodyHeight[BH], p = 0.001) than the NPI pitchers. CM/ST had significantly greater normalized elbow anterior force (p = 0.031), elbow flexion torque (p = 0.002), and shoulder adduction torque (p = 0.007) than NPI pitchers. Conclusion: Professional baseball pitchers with prior core/groin injuries demonstrated increased elbow anterior force and elbow flexion torque compared to pitchers with no prior core injuries. One possible explanation for this finding includes inadequate recruitment and utilization of the lower extremities as a component of the kinetic chain leading to compensation at the level of the throwing arm. Whether these kinetic differences arise as a consequence of injury or present a risk for such warrants additional investigation.

Increased Elbow and Olecranon Injury History in Professional Pitchers With Increased Elbow Flexion at Ball Release.

BACKGROUND: Elbow flexion at late portions of the pitch has been associated with increased elbow varus torque, a kinetic surrogate associated with injury risk. Direct examinations of injury incidence with elbow flexion angles have not been conducted in professional pitchers. PURPOSE: To compare elbow and shoulder injury incidence among professional baseball players stratified by degree of elbow flexion at ball release (BR). STUDY DESIGN: Descriptive laboratory study. METHODS: Professional pitchers (N = 314) were instructed to pitch between 8 and 12 fastballs while being evaluated using motion capture technology. Upper extremity injury incidence was recorded upon interview. Pitchers were subsequently subdivided into 3 groups based on increasing elbow flexion at BR. Analysis of variance was used to compare participant characteristics and kinematic and peak kinetic variables. An odds ratio (OR) was calculated to determine the risk of having a previous upper extremity injury based on the degree of elbow flexion at BR. RESULTS: A total of 116 pitchers (132 documented injuries) had a previous upper extremity injury, with elbow injury (76 injuries; 57.6%) being the most common. Evaluation of kinetic values showed that pitchers with the smallest elbow flexion at BR had significantly less peak elbow flexion torque than did those with greatest elbow flexion at BR (3.8 ± 0.5 vs 4.1 ± 0.6 %weight × height; P = .003). Pitchers who demonstrated a greater than average degree of elbow flexion at BR when pitching were more likely to have a history of elbow injury (OR, 1.97; 95% CI, 1.14-3.40; P = .015) and olecranon spur formation or stress fracture (OR, 5.79; 95% CI, 1.25-26.85; P = .025). CONCLUSION: Pitchers with greater elbow flexion at BR had significantly higher odds of previous injury of the elbow and olecranon. Increasing elbow flexion has been shown to place the medial elbow in a position to carry a greater amount of load, which may be exacerbated during the final moments of the pitching motion. Professional pitchers can consider decreasing elbow flexion at BR as a potential, modifiable risk factor for elbow injury, in particular for olecranon spur formation and fracture. CLINICAL RELEVANCE: This study attempts to associate injury incidence with a modifiable, kinematic variable for an at-risk population.