Publications by Year: 2024

Introduction: Tendinopathy is a degenerative condition resulting from tendons experiencing abnormal levels of multi-scale damage over time, impairing their ability to repair. However, the damage markers associated with the initiation of tendinopathy are poorly understood, as the disease is largely characterized by end-stage clinical phenotypes. Thus, this study aimed to evaluate the acute tendon responses to successive fatigue bouts of tendon overload using an in vivo passive ankle dorsiflexion system. Methods: Sprague Dawley female rats underwent fatigue overloading to their Achilles tendons for 1, 2, or 3 loading bouts, with two days of rest in between each bout. Mechanical, structural, and biological assays were performed on tendon samples to evaluate the innate acute healing response to overload injuries. Results: Here, we show that fatigue overloading significantly reduces in vivo functional and mechanical properties, with reductions in hysteresis, peak stress, and loading and unloading moduli. Multi-scale structural damage on cellular, fibril, and fiber levels demonstrated accumulated micro-damage that may have induced a reparative response to successive loading bouts. The acute healing response resulted in alterations in matrix turnover and early inflammatory upregulations associated with matrix remodeling and acute responses to injuries. Discussion: This work demonstrates accumulated damage and acute changes to the tendon healing response caused by successive bouts of in vivo fatigue overloads. These results provide the avenue for future investigations of long-term evaluations of tendon overload in the context of tendinopathy.

BACKGROUND: Osteoporosis (OP) and osteomalacia (OM) are metabolic bone diseases characterized by mineral and matrix density changes. Quantitative bone matrix density differentiates OM from OP. MRI is a noninvasive and nonionizing imaging technique that can measure bone matrix density quantitatively in ex vivo and in vivo.

PURPOSE: To demonstrate water + fat suppressed 1H MRI to compute bone matrix density in ex vivo rat femurs in the preclinical model.

STUDY TYPE: Prospective.

ANIMAL MODEL: Fifteen skeletally mature female Sprague-Dawley rats, five per group (normal, ovariectomized (OVX), partially nephrectomized/vitamin D (Vit-D) deficient), 250-275 g, ∼15 weeks old.

FIELD STRENGTH/SEQUENCE: 7T, zero echo time sequence with water + fat (VAPOR) suppression capability, μCT imaging, and gravimetric measurements.

ASSESSMENT: Cortical and trabecular bone segments from normal and disease models were scanned in the same coil along with a dual calibration phantom for quantitative assessment of bone matrix density.

STATISTICAL TESTS: ANOVA and linear regression were used for data analysis, with P-values <0.05 statistically significant.

RESULTS: The MRI-derived three-density PEG pellet densities have a strong linear relationship with physical density measures (r2 = 0.99). The Vit-D group had the lowest bone matrix density for cortical bone (0.47 ± 0.16 g cm-3), whereas the OVX had the lowest bone matrix density for trabecular bone (0.26 ± 0.04 g cm-3). Gravimetry results confirmed these MRI-based observations for Vit-D cortical (0.51 ± 0.07 g cm-3) and OVX trabecular (0.26 ± 0.03 g cm-3) bone groups.

DATA CONCLUSION: Rat femur images were obtained using a modified pulse sequence and a custom-designed double-tuned (1H/31P) transmit-receive solenoid-coil on a 7T preclinical MRI scanner. Phantom experiments confirmed a strong linear relation between MRI-derived and physical density measures and quantitative bone matrix densities in rat femurs from normal, OVX, and Vit-D deficient/partially nephrectomized animals were computed.

LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 2.

BACKGROUND: Little is known about the burden or management of distal radius fractures (DRFs) in low- and middle-income countries. The purpose of this study was to describe the care of DRFs in Malawi.

METHODS: We retrospectively reviewed a registry of all patients with fractures who presented to the orthopaedic departments at four public hospitals in Malawi.

RESULTS: Totally, 1,440 patients (14.5%) were with a DRF. Average age was 40, and 888 (62.0%) were male. Surgery was done for 122 patients (9.5%). Patients presenting to Queen Elizabeth Hospital, patients presenting after a fall, and patients initially evaluated by an orthopaedic registrar or orthopaedic clinical officer had lower odds of receiving surgical treatment. Meanwhile, open injuries had the greatest odds of receiving surgery.

CONCLUSION: The most common musculoskeletal injury among patients in the Malawi Fracture Registry was fractures of the distal radius. These most affected young adult male patients may benefit from surgery; however, the majority were managed nonsurgically. Lack of access to surgical fixation and conservative follow-up may have long-term functional consequences in a predominantly agrarian society. Outcomes-based research is needed to help guide management decisions and standardize patient care and referral protocols.

Background  The impact of diabetes on complication rates following free flap (FF), pedicled flap (PF), and amputation (AMP) procedures on the lower extremity (LE) is examined. Methods  Patients who underwent LE PF, FF, and AMP procedures were identified from the 2010 to 2020 American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP®) database using Current Procedural Terminology and International Classification of Diseases-9/10 codes, excluding cases for non-LE pathologies. The cohort was divided into diabetics and nondiabetics. Univariate and adjusted multivariable logistic regression analyses were performed. Results  Among 38,998 patients undergoing LE procedures, 58% were diabetic. Among diabetics, 95% underwent AMP, 5% underwent PF, and <1% underwent FF. Across all procedure types, noninsulin-dependent (NIDDM) and insulin-dependent diabetes mellitus (IDDM) were associated with significantly greater all-cause complication rates compared with absence of diabetes, and IDDM was generally higher risk than NIDDM. Among diabetics, complication rates were not significantly different across procedure types (IDDM: p  = 0.5969; NIDDM: p  = 0.1902). On adjusted subgroup analysis by diabetic status, flap procedures were not associated with higher odds of complications compared with amputation for IDDM and NIDDM patients. Length of stay > 30 days was statistically associated with IDDM, particularly those undergoing FF (AMP: 5%, PF: 7%, FF: 14%, p  = 0.0004). Conclusion  Our study highlights the importance of preoperative diabetic optimization prior to LE procedures. For diabetic patients, there were few significant differences in complication rates across procedure type, suggesting that diabetic patients are not at higher risk of complications when attempting limb salvage instead of amputation.

In the 1960s, the American Society for Surgery of the Hand embarked on an endeavor to improve and standardize the educational experience in hand surgery. By the 1980s, numerous programs existed across the country with the Accreditation Council for Graduate Medical Education formally recognizing orthopedic surgery-based fellowships in 1985 and plastic surgery-based fellowships in 1986. In order to sit for what was then termed the Certificate of Additional Qualification examination, applicants had to demonstrate performance of a specific number of procedures while in practice. Borrowing from this theme, the Accreditation Council for Graduate Medical Education began to analyze programs according to the relative proportion of cases done by fellows at individual institutions compared to national trends. Beginning in 2019 and working collaboratively with the Accreditation Council for Graduate Medical Education, the Hand Fellowship Director's Association has since modified the methods by which programs are evaluated, pivoting away from comparative percentages to the establishment of case minimums. The development of this process has been iterative with the resultant outcome being an evaluation system that focuses on educational quality and technical proficiency over sheer numerical volume.

PURPOSE OF REVIEW: Arthroscopy has become increasingly popular for a addressing a wide variety of shoulder pathology. However, despite increasing interest, there is still much uncertainty and variability amongst providers regarding optimal post-operative rehabilitation. This review provides an overview of the evidence underlying common rehab protocols used following arthroscopic interventions for rotator cuff disease, shoulder instability, superior labral anterior to posterior (SLAP) tears and adhesive capsulitis.

RECENT FINDINGS: For small and medium sized rotator cuff tears, early motion protocols do not seem to affect healing or retear rates, however there is no difference with regards to long term functional outcomes when compared to standard motion protocols. For larger tears (> 3 cm), early active motion may be associated with impaired tendon integrity. Early range of motion following arthroscopic Bankart repair has not been shown to increase rate of recurrence, however the data on return to sport requires more granularity to effectively guide care. Further research needs to be done to compare rehab protocols following SLAP repair and arthroscopic capsular release. Rehabilitation protocols following rotator cuff surgery and anterior shoulder stabilization have garnered the most research interest. However, there is still a need for larger higher-level studies examining the long-term effects of different rehab protocols. Regarding the arthroscopic management of other types of shoulder instability, SLAP tears and adhesive capsulitis, there is paucity of high-quality evidence. This knowledge gap likely underpins the variability in different rehab protocols seen in clinical practice, highlighting the need for more research.

Osteoporosis is the most common chronic metabolic bone disease worldwide. Vertebral compression fracture (VCF) is the most common type of osteoporotic fracture. Approximately 700,000 osteoporotic VCFs are diagnosed annually in the USA alone, resulting in an annual economic burden of  $13.8B. With an aging population, the rate of osteoporotic VCFs and their associated burdens are expected to rise. Those burdens include pain, functional impairment, and increased medical expenditure. Therefore, it is of utmost importance to develop an analytical tool to aid in the identification of VCFs. Computed Tomography (CT) imaging is commonly used to detect occult injuries. Unlike the existing VCF detection approaches based on CT, the standard clinical criteria for determining VCF relies on the shape of vertebrae, such as loss of vertebral body height. We developed a novel automated vertebrae localization, segmentation, and osteoporotic VCF detection pipeline for CT scans using state-of-the-art deep learning models to bridge this gap. To do so, we employed a publicly available dataset of spine CT scans with 325 scans annotated for segmentation, 126 of which also graded for VCF (81 with VCFs and 45 without VCFs). Our approach attained 96% sensitivity and 81% specificity in detecting VCF at the vertebral-level, and 100% accuracy at the subject-level, outperforming deep learning counterparts tested for VCF detection without segmentation. Crucially, we showed that adding predicted vertebrae segments as inputs significantly improved VCF detection at both vertebral and subject levels by up to 14% Sensitivity and 20% Specificity (p-value = 0.028).

Fibrotic changes in musculoskeletal diseases arise from the abnormal buildup of fibrotic tissue around the joints, leading to limited mobility, compromised joint function, and diminished quality of life. Relaxin (RLX) attenuates fibrosis by accelerating collagen degradation and inhibiting excessive extracellular matrix (ECM) production. Further, RLX disrupts myofibroblast activation by modulating the TGF-β/Smads signaling pathways, which reduces connective tissue fibrosis. However, the mechanisms and effects of RLX in musculoskeletal pathologies are emerging as increasing research focuses on relaxin's impact on skin, ligaments, tendons, cartilage, joint capsules, connective tissues, and muscles. This review delineates the actions of relaxin within the musculoskeletal system and the challenges to its clinical application. Relaxin shows significant potential in both in vivo and in vitro studies for broadly managing musculoskeletal fibrosis; however, challenges such as short biological half-life and sex-specific responses may pose hurdles for clinical use.

BACKGROUND: Stem fixation in reconstruction after resection of femoral tumors is debated. Cemented stems offer immediate stability but risk aseptic loosening, while press-fit stems allow bone ingrowth but risk stress shielding and subsidence. Our retrospective review aimed to determine implant failure rates and their associated factors, as well as the rates of infection, debridement, and mortality for both fixation groups (cemented or press-fit stems) used in patients undergoing resection of femoral tumor disease and subsequent arthroplasty.

METHODS: We retrospectively studied 252 patients who underwent resection of femoral tumors and subsequent arthroplasty using cemented (n = 173; 69%) or press-fit (noncemented) (n = 79; 31%) stems between 1999 and 2020. Implant failure was the primary outcome, with secondary outcomes including rates of implant infection, debridement, and mortality. Multivariable regression was done to assess risk factors for implant failures.

RESULTS: The study found implant failure rates of 11% and 18% for cemented stems and press-fit stems, respectively. Lower stem to diaphyseal ratios ( P = 0.024) and younger patients ( P = 0.008) were associated with a higher risk of implant failure in cemented stems. The infection rates were 14% and 10% for cemented and press-fit stems, respectively. Debridement rates were 16% and 13% for cemented and press-fit stems, respectively, while the 1-year mortality rate was 16% for cemented stems and 1.5% for press-fit stems.

CONCLUSIONS: This study is the largest of its kind, providing patient characteristics and outcomes in both cemented and press-fit stems in the setting of reconstruction for femoral tumors. Both methods can be effective, with outcomes dependent on patient-specific factors, such as life expectancy, activity level, and body habitus, as well as proper implant fit. Additional studies of both implants and longer follow-up are required to elucidate the optimal fixation method for each individual patient.

LEVEL OF EVIDENCE: Level III, retrospective noncomparative study.