Publications by Year: 2024

BACKGROUND: Pediatric fractures are common in Malawi, and surgical care, when needed, remains inaccessible to many. Understanding which children in Malawi receive surgery or nonsurgical treatment would help set priorities for trauma system development.

METHODS: We used multivariate logistic regression to evaluate associations between surgical treatment and age, sex, school enrollment, injury mechanism, fracture type, open fracture, referral status, hospital of presentation, delayed presentation (≥2 days), healthcare provider, and inpatient vs outpatient treatment.

RESULTS: From 2016 to 2020, 10,400 pediatric fractures were recorded in the Malawi Fracture Registry. Fractures were most commonly of the wrist (26%), forearm (17%), and elbow (14%). Surgical fixation was performed on 4.0% of patients, and 24 (13.0%) open fractures were treated nonsurgically, without débridement or fixation. Fractures of the proximal and diaphyseal humerus (odds ratio [OR], 3.72; 95% confidence interval [CI], 2.36 to 5.87), knee (OR, 3.16; 95% CI, 1.68 to 5.95), and ankle (OR, 2.63; 95% CI, 1.49 to 4.63) had highest odds of surgery. Odds of surgical treatment were lower for children referred from another facility (OR, 0.62; 95% CI, 0.49 to 0.77).

CONCLUSIONS: Most Malawian children with fractures are treated nonsurgically, including many who may benefit from surgery. There is a need to increase surgical capacity, optimize referral patterns, and standardize fracture management in Malawi.

The supraspinatus tendon plays a crucial role in shoulder abduction, making it one of the common structures affected by injury. Clinically, crescent-shaped tears are the most commonly seen tear shape. By developing six specimen-specific, three-dimensional, supraspinatus-infraspinatus finite element model with heterogeneous material properties, this study aimed to examine the changes in tissue deformation (maximum principal strain) of the supraspinatus tendon due to specimen-specific material properties and rotator cuff tear size. FE models with small- and medium-sized full-thickness crescent-shaped tears were subjected to loads seen during activities of daily living and physiotherapy. Six fresh-frozen cadaveric shoulders were dissected to mechanically test the supraspinatus tendon and develop and validate FE models that can be used to assess changes in strain due to small (< 1 cm, equivalent to 20-30% of the tendon width) and medium-sized (1-3 cm, equivalent to 40-50% of the tendon width) tears that are located in the middle and posterior regions of the supraspinatus tendon. FE predictions of maximum principal strain at the tear tips were examined to determine whether failure strain was reached during activities of daily living (drinking and brushing teeth) and physiotherapy exercises (prone abduction and external rotation at 90° abduction). No significant differences were observed between the middle and posterior tear failure loads for small- and medium-sized tears. For prone abduction, there was a potential risk for tear progression (exceeded failure strain) for medium-sized tears in the supraspinatus tendon's middle and posterior regions. For external rotation at 90° abduction, one model with a middle tear and two with posterior tears experienced failure. For all daily activity loads, the strain never exceeded the failure strain. Our three-dimensional supraspinatus-infraspinatus FE model shows that small tears appear unlikely to progress based on the regional strain response; however, medium-sized tears are at higher risk during more strenuous physiotherapy exercises. Furthermore, differences in patient-specific tendon material properties are important in determining whether the tear will progress. Therefore, patient-specific management plans based on tear size may be beneficial to improve clinical outcomes.

BACKGROUND: Growing interest has motivated recent studies to examine differences in recovery after sport-related concussion (SRC) by sex. However, heterogeneity in study design, participants, and recovery outcomes has led to mixed findings. Further work is needed to evaluate potential differences by sex and to investigate the role of related characteristics, such as sport contact-level, in recovery timelines. This study aimed to investigate whether concussion recovery trajectories differ by sex, considering a priori clinical and demographic covariates, and accounting for the sequence of recovery outcomes. Our secondary question was whether sport contact-level modifies the relationship between sex and time to outcomes. Using data from the Ivy League-Big Ten Epidemiology of Concussion Study, we included SRCs reported across five academic years; 2015-2020 (February 2020). We used Cox proportional hazards regressions to estimate associations between sex and time from injury to three outcomes: (1) symptom resolution, (2) return to academics, (3) return to full play, accounting for measured confounders.

RESULTS: Among 1160 SRCs (male, n = 667; female, n = 493) with complete data, median age overall was 20 years (25th-75th percentiles:19-21), and most occurred among athletes playing high-contact sports (78.0%). Males were slightly more likely to complete symptom resolution over time compared to females (HR = 1.18, 95%CI = 1.05-1.33), but results were attenuated in fully adjusted models (HR 1.13, 95%CI = 0.99-1.29). Similarly, the HR of full academic return for males compared to females was 1.22 (95%CI = 1.07-1.38), but was attenuated in fully adjusted models (HR = 1.11, 95%CI = 0.97-1.28). The HR of full return to play for males compared to females was 1.14 (95%CI = 1.02-1.28), and was attenuated after adjustment (HR = 1.06, 95%CI = 0.93-1.20) as well. The interaction between sex and playing a high/low-contact sport was not statistically significant across models, though differences were apparent.

CONCLUSIONS: Among a cohort of collegiate athletes with SRC, recovery timelines appeared similar between male and female athletes, adjusting for measured confounders. Differences by sex, considering sport contact-level, were evident and may be important clinically and in future studies. This study used robust methods, accounting for nesting in the sequence of RTP outcomes. Results inform concussion management protocols and planned qualitative work to further elucidate how collegiate athletes experience concussion recovery.

KEY POINTS: Heterogeneity in study design, participants, and recovery outcomes has led to mixed findings in determining differences in recovery trajectories after concussion by sex. We found that having longer time to symptom resolution, and also the sequence of having academic return before symptoms resolve and longer time to academic return were confounders in the relationship between sex and RTP timelines. Time to sequential recovery outcomes appeared similar between male and female athletes, adjusting for observable confounders. Further differences by sex were evident when considering contact-level, and may be important to consider clinically and in future research. Results indicate that differences in concussion recovery trajectories by sex may be largely attributed to and driven by differences in sports with a men's or women's team only, such as football, and this should be explored further.

Background: Lower extremity reconstructive surgery is an evolving field wherein patients rely on accessible online materials to engage with their perioperative care. This study furthers existing research in this area by evaluating the readability, understandability, actionability, and cultural sensitivity of online health materials for lower extremity reconstruction. Methods: We identified the 10 first-appearing, educational sites found by searching the phrases "leg saving surgery", "limb salvage surgery," and "leg reconstruction surgery". Readability analysis was conducted with validated tools, including Simple Measure of Gobbledygook (SMOG). Understandability and actionability were assessed with Patient Education and Materials Assessment Tool (PEMAT), while cultural sensitivity was measured with Cultural Sensitivity Assessment Tool (CSAT). A Cohen's κ value was calculated (PEMAT and CSAT analyses) for inter-rater agreement. Results: The mean SMOG reading level for websites was 13.12 (college-freshman reading level). The mean PEMAT understandability score was 61.8% and actionability score was 26.0% (κ = 0.8022), both below the 70% acceptability threshold. The mean CSAT score was 2.6 (κ = 0.73), exceeding the 2.5 threshold for cultural appropriateness. Conclusion: Online PEM for lower extremity reconstruction continue to fall below standards of readability, understandability, and actionability; however, they meet standards of cultural appropriateness. As patients rely on these materials, creators can use validated tools and positive examples from existing PEM for greater patient accessibility.

BACKGROUND: Stemless shoulder arthroplasty offers several advantages, such as preserving bone stock and reducing periprosthetic fracture risk. However, implant motion can deter osteointegration and increase bone resorption, where micromotion less than 0.150 mm is crucial for bony ingrowth and vital to the success of the implant. The interaction between the implant and the metaphyseal bone and its effects on stability remains unclear. Therefore, this cadaveric study aims to assess the immediate stability of two stemless prostheses in low bone density specimens.

METHODS: Twenty cadaveric shoulders were used to compare the stability of two stemless shoulder implants by Zimmer-Biomet (model A) and Exactech (model B), subjected to loads of 220 N, 520 N, and 820 N to assess strain and micromotion.

FINDINGS: Micromotion at 220 N load was 0.061 ± 0.080 mm and 0.053 ± 0.050 mm, and at 520 N load, 0.279 ± 0.37 mm and 0.311 ± 0.35 mm for models A and B, respectively. The estimated mean force required to achieve a 150 μm micromotion was 356 ± 116 N and 315 ± 61 N for models A and B, respectively. Motion analysis revealed distinct movement patterns for each implant, with model B demonstrating better force distribution on the bone despite no significance.

INTERPRETATION: Forces over 520 N (high postoperative rehabilitation force) could hinder bone integration with prostheses due to excessive micromotion. Conversely, forces around 220 N (preconditioning loading force) are considered safe for prosthesis stability even with low bone density. These insights may caution against using stemless implants when bone density is low, and help guide clinical decisions on the duration of rehabilitation and sling use after stemless arthroplasty.

BACKGROUND: Augmentation of an arthroscopic Bankart repair with the remplissage (ABR) procedure has shown to confer a decrease in recurrence rates, yet, at the expense of potentially compromising shoulder motion.

PURPOSE/HYPOTHESIS: The purpose was to examine clinical studies that described a post-operative rehabilitation protocol after an arthroscopic Bankart repair and remplissage procedure. It was hypothesized that a review of the literature would find variability among the studies and that, among comparative studies, there would be a limited distinction from protocols for isolated Bankart repairs.

STUDY DESIGN: Systematic Review.

MATERIALS AND METHODS: A search was conducted using three databases (PubMed, EMBASE, and CINAHL) according to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. The following terms were combined while utilizing Boolean operators: (Bankart lesion OR labral tear) AND (remplissage). Studies evaluating patients after arthroscopic stabilization for unidirectional anterior glenohumeral instability with the addition of the remplissage procedure and at least 1 year follow-up were included for analysis.

RESULTS: A total of 41 studies (14 Level IV, 24 Level III, 2 Level II, and 1 Level I) were included with a total of 1,307 patients who underwent ABR. All patients had <30% glenoid bone loss and a range of 10-50% humeral head size Hill-Sachs lesion. Type and position of immobilization were the most reported outcomes (41/41) followed by time of immobilization (40/41). Moreover, 23/41 studies described their initial post-operative shoulder range of motion restrictions, while 17/41 specified any shoulder motion allowed during this restrictive phase. Time to return to sport was also described in 37/41 of the retrieved studies. Finally, only two of the 27 comparative studies tailored their rehabilitation protocol according to the specific procedure performed, underscoring the lack of an individualized approach (i.e. same rehabilitation protocol for different procedures).

CONCLUSION: The results of the present systematic review expose the variability among rehabilitation protocols following ABR. This variability prompts consideration of the underlying factors influencing these disparities and underscores the need for future research to elucidate optimal rehabilitation. Based on the results of this systematic review and the senior authors´ clinical experience, a rehabilitation approach similar to an isolated Bankart repair appears warranted, with additional precautions being utilized regarding internal rotation range of motion and external rotation strengthening.

LEVEL OF EVIDENCE: Level 3.

BACKGROUND: While rotator cuff tears are prevalent in the general population, the natural history of this disease is unclear. Understanding rotator cuff tear progression is crucial for refining surgical indications and evaluating the necessity of early interventions. This study presents an in-depth analysis of the existing literature on the definitions and progression rates of rotator cuff tears, aiming to enhance clinical decision making and patient outcomes.

METHODS: A systematic literature search was conducted based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, using Medline (PubMed), Embase (Elsevier), and Web of Science databases on January 12, 2023. Articles were identified as relevant to the natural history and progression of asymptomatic and symptomatic partial-thickness (PT) and full-thickness (FT) rotator cuff tears. Those written in English reporting rotator cuff progression rates of tears in adults, based on magnetic resonance imaging (MRI) or ultrasound, were included. After reviewing the articles, the data on the rates of tear progression and associated risk factors were extracted, compiled, and analyzed. The risk of bias was determined using the Newcastle-Ottawa Scale.

RESULTS: Twenty-one articles met the inclusion criteria, with 1,831 tears included. The progression rate for all partial thickness tears was 26.7% ± 12.8% at an average follow-up of 2.2 ± 0.9 years, with 5 definitions for tear progression. For FT tears, the progression rate was 54.9% ± 18.6% at a follow-up time of 3.0 ± 2.0 years, with 8 definitions for tear enlargement. A significant difference (p < 0.0001) was found between the progression rates of PT and FT tears. Patients who were initially asymptomatic and became symptomatic had higher progression rates (33%-63%) than those who remained asymptomatic (4%-38%).

CONCLUSION: Further research would benefit by identifying a clinically relevant and standardized definition of rotator cuff tear progression, to describe the natural history of rotator cuff disease, making results more comparable and optimizing treatment planning.

LEVEL OF EVIDENCE: Level II. See Instructions for Authors for a complete description of levels of evidence.

Background: Free tissue transfer is a valuable surgical option for the reconstruction of a myriad of complex lower extremity defects. Currently, there is a paucity of data that examines the risks of complications for each of these unique indications. Methods: Patients undergoing lower extremity free flap reconstruction from the ACS-NSQIP 2011-2019 database were stratified into groups based on the etiology and indication for reconstruction. Rates of major, surgical wound, and medical complications were compared over the first post-operative month. Multivariable logistic regression was used to identify complication predictors. Results: 425 lower extremity free flaps were analyzed. The most common indications for lower extremity free flap reconstruction were wound-related (29%), malignancy (21%), and trauma (17%). Seventeen percent of free flaps had a major post-operative complication, 9% had a surgical wound complication, and 16% had a medical complication. There were no significant differences in major complications between the indications. However, the independent risk factors for major complications varied widely. Those with an indication of malignancy and those who received a musculocutaneous free flap were significantly more likely to have a surgical wound complication compared to the remaining cohort (p < 0.05). Those requiring free flap reconstruction for orthopedic hardware related concerns as well as those with wound related indications were significantly more likely to have a post-operative medical complication (p < 0.05). Conclusion: Understanding the unique risk profiles between the various indications and populations of patients undergoing lower extremity free flap reconstruction is critical for providing accurate risk estimations and optimizing post-operative outcomes and monitoring. Keywords microsurgery, lower extremity free flap, free flap reconstruction.