Blood flow restriction (BFR) is an expanding rehabilitation modality that uses a tourniquet to reduce arterial inflow and occlude venous outflow in the setting of resistance training or exercise. Initially, this technique was seen as a way to stimulate muscular development, but improved understanding of its physiologic benefits and mechanism of action has allowed for innovative clinical applications. BFR represents a way to decrease stress placed on the joints without compromising improvements in strength, whereas for postoperative, injured, or load‐compromised individuals BFR represents a way to accelerate recovery and prevent atrophy. There is also growing evidence to suggest that it augments cardiovascular fitness and attenuates pain. The purpose of this review is to highlight the physiology and evidence behind the various applications of BFR, with a focus on postoperative rehabilitation. While much remains to be learned, it is clear that blood flow restriction therapy stimulates muscle hypertrophy via a synergistic response to metabolic stress and mechanical tension, with supplemental benefits on cardiovascular fitness and pain. New forms of BFR and expanding applications in postoperative patients and athletes hold promise for expedited recovery. Continued adherence to rehabilitation guidelines and exploration of BFRs physiology and various applications will help optimize its effect and prescription. Level of Evidence: V, expert opinion.

Although the majority of patients with patellar tendinopathy (PT) can be treated nonoperatively, operative management may be indicated for recalcitrant cases. While several surgical techniques have been described, there is limited understanding of postoperative outcomes and expectations regarding return to activity and sport. The purpose of this study was to characterize the clinical outcomes associated with the surgical management of PT with an emphasis on return to sport (RTS) rates. We hypothesized that surgical management would lead to clinically important improvements in patient-reported outcomes (PROs) with high rates of RTS and RTS at the same level. A comprehensive search of the PubMed, Medline, and Embase databases was performed in December 2020. Level of evidence studies I through IV, investigating results of surgical management for PT (PRO, functional outcomes, pain, and/or RTS), were included. The search was performed in accordance with the Preferred Reported Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Forty clinical studies reporting on surgery for PT satisfied inclusion criteria, with 1,238 total knees undergoing surgery for PT. A comparison of pre- and postoperative Victorian Institute of Sport Assessment, patellar tendon (VISA-P) scores (mean difference: 41.89, p < 0.00001), Lysholm scores (mean difference: 41.52, p < 0.00001), and visual analogue scale (VAS) pain scores (mean difference: 5, p < 0.00001) demonstrated clinically and statistically significant improvements after surgery. The overall RTS rate following operative management was 89.8% (95% confidence interval [CI]: 86.4–92.8, I ² = 56.5%) with 76.1% (95% CI: 69.7.5–81.9, I ² = 76.4%) of athletes returning to the same level of activity. Surgery for PT provides meaningful improvement in patient reported outcomes and pain while allowing athletes to RTS at high rates with levels of participation similar to that of preinjury. Comparative studies of open and/or arthroscopic surgery are still limited but current evidence suggests better rates of RTS for arthroscopic surgery compared with open surgery. This is a systematic review of level-I to -IV studies. Received: 15 November 2021 Accepted: 26 April 2022 Article published online: 26 September 2022 © 2022. Thieme. All rights reserved. Thieme Medical Publishers, Inc. 333 Seventh Avenue, 18th Floor, New York, NY 10001, USA

Background: Multiple surgical treatments exist for proximal humerus fractures (PHFs), but current practice patterns and short-term complication profiles remain poorly understood. This is in part due to changes in treatment paradigms over the past decade. A more thorough understanding of the evolution in management over this time as well as an appreciation of the preoperative factors associated with both the chosen surgical modality and short-term complications will help inform future surgical considerations. Questions/purposes: In this study, we sought to: (1) characterize trends in the surgical management of PHFs over time, including usage rates of various surgical modalities and changes in complication rates; (2) identify preoperative variables associated with the selection of surgical modality; and (3) assess the independent covariates of acute 30-day complications, including demographic variables, injury characteristics, and treatment type. Methods: The National Surgical Quality Improvement Program (NSQIP) database was queried using Current Procedural Terminology and ICD-9 and ICD-10 codes to identify individuals with PHF undergoing open reduction and internal fixation (ORIF), hemiarthroplasty (HA), or reverse total shoulder arthroplasty (RTSA) from 2007 to 2018. The NSQIP database was utilized because of its collection of detailed preoperative demographic information and large repository of clinically derived data, which is felt to be more accurate than claims or administrative data. In total, 5889 patients with PHFs met the inclusion criteria. Patients 17 years or older were included. Patients with isolated greater tuberosity, humeral shaft, and distal humerus fractures; nonunions; malunions; and those undergoing revision procedures were excluded. A Cochran-Armitage test was used to evaluate surgical trends over time. Multivariable logistic regression models were created to identify covariates associated with surgical modality and complications. Although complications were either classified as major or minor, specific complications were also individually analyzed to avoid potentially misleading conclusions associated with pooling. Results: The proportion of patients with PHFs undergoing RTSA (4% in 2007 and 34% in 2018; p < 0.001) and ORIF (46% in 2007 and 57% in 2018; p < 0.001) increased over time, and the proportion of those undergoing HA (50% in 2007 and 9% in 2018; p < 0.001) decreased. Across each surgical modality, minor complication rates decreased over time (RTSA: 10% in 2018; p < 0.001; ORIF: 5% in 2018; p = 0.01; and HA: 6% in 2018; p = 0.01). After controlling for confounding variables like diabetes, chronic obstructive pulmonary disease, congestive heart failure, dialysis, and preoperative blood transfusion, the following factors were independently associated with an increased odds of a patient undergoing RTSA rather than HA: older age, higher BMI, independent functional status, and smoking. The following factors were independently associated with a decreased odds of a patient undergoing ORIF rather than RTSA and HA: older age, higher BMI, higher American Society of Anesthesiologists (ASA) classification, smoking, steroid/immunosuppressant use, as well as three- and four-part fractures. After controlling for age, ASA classification, functional status, and preoperative blood transfusion, we also found that in the latter part of the study period, arthroplasty (RTSA and HA) was no longer independently associated with 30-day major or minor complications compared with ORIF. Conclusion: The increasing utilization of RTSA and decreasing short-term complication rates for fixation and arthroplasty alike represent a substantial change compared even with recent historic norms in the management of proximal humerus fractures. Quantifying demographics, injury characteristics, and comorbidities associated with both the choice of surgical modality and complications serves as the groundwork for decision support tools, which can inform patients and surgeons of the probability of a particular surgical modality being chosen and the risk of complications, based on national benchmarks. Future studies should investigate longer term complication rates, as many differences between the approaches being compared might occur beyond the perioperative period and our study had no means to address questions about complications beyond that period, but obviously those must be considered when choosing a treatment for patients with these injuries. Future work might also investigate the mechanisms behind the decreasing rates of short-term complications. Level of Evidence: Level III, therapeutic study.

Tendon injuries in military servicemembers are one of the most commonly treated nonbattle musculoskeletal injuries (NBMSKIs). Commonly the result of demanding physical training, repetitive loading, and frequent exposures to austere conditions, tendon injuries represent a conspicuous threat to operational readiness. Tendon healing involves a complex sequence between stages of inflammation, proliferation, and remodeling cycles, but the regenerated tissue can be biomechanically inferior to the native tendon. Chemical and mechanical signaling pathways aid tendon healing by employing growth factors, cytokines, and inflammatory responses. Exosome-based therapy, particularly using adipose-derived stem cells (ASCs), offers a prominent cell-free treatment, promoting tendon repair and altering mRNA expression. However, each of these approaches is not without limitations. Future advances in tendon tissue engineering involving magnetic stimulation and gene therapy offer non-invasive, targeted approaches for improved tissue engineering. Ongoing research aims to translate these therapies into effective clinical solutions capable of maximizing operational readiness and warfighter lethality.

Study Design A retrospective case-series of revision sacroiliac joint (SIJ) fusions. Objective To provide a technique guide for revision minimally invasive SIJ fusion. Summary of Background Data SIJ dysfunction is a prevalent, yet underdiagnosed condition. This disparity exists as a result of diagnostic complexity and lack of a viable surgical treatment option. However, the advent of minimally invasive SIJ fusion has created a resurgence of interest in this debilitating condition. Multiple studies have reported on the increased use of minimally invasive SIJ fusion in recent years, but there is a paucity of literature on management in a revision setting. Methods A case series of 5 patients from a single academic tertiary referral center over a 3-year period will serve to highlight technical pearls and considerations in SIJ fusion revision. Revision SIJ fusions were identified through a retrospective review of a surgical database and demographic, surgical, and radiographic data were obtained through review of the electronic medical record. Results Five patients underwent SIJ fusion revision from 2015 to 2018. There were 3 main modes of failure, with indications for revision including nerve root irritation and SIJ pain recurrence. The mean age at time of revision was 48.8 ± 14.3 years, and the mean follow-up after revision was 2.0 + 0.9 years. Familiarity with SIJ anatomy and use of stereotactic navigation can improve implant position and purchase. Additionally, bone graft and bone morphogenetic protein can be used to fill in old implant tracks and to augment bony ingrowth and ongrowth of new implants. Conclusions Increased use of SIJ fusion creates a demand for comprehensive revision strategies and necessitates familiarity with SIJ anatomy. Preoperative planning to determine causes of failure and use of intraoperative navigation are essential to help surgeons better understand the preferential trajectory for each implant. Level of Evidence 4.