Selim, Omar

Abstract Carpal fractures are uncommon, representing a small proportion of hand fractures. This study aimed to determine the incidence, injury mechanisms, treatment patterns, and complication rates of carpal fractures in Olmsted County, Minnesota, United States. A retrospective review was performed using the Rochester Epidemiology Project registry to identify carpal fractures between 2013 and 2023. Fractures were confirmed by radiographs, computed tomography, or radiology reports. Demographic data, injury mechanism, fracture laterality, and fracture characteristics were recorded. A total of 699 carpal fractures were identified. Most patients were men (57%) with a mean age of 43 years. The most common fracture was the scaphoid (44%), followed by the triquetrum (31%), hamate (9%), and trapezium (3%). The overall incidence was 53.6 per 100,000 person-years. Concomitant wrist fractures occurred in 22%, and multiple ipsilateral carpal fractures in 4.6%. Patients with triquetrum fractures had the highest mean age (54 years) and low surgical rates (2%), whereas hamate and trapezoid fractures occurred at younger ages (39 and 38 years) and had the highest surgical rates (28 and 33%, respectively). The most common injury mechanism was a fall onto an outstretched hand (n = 438). Overall, 14% (n = 98) of patients underwent surgery, of whom 77% were men. The highest nonunion rate was seen in hamate fractures (10.9%), followed by scaphoid waist and proximal pole fractures (10.5%). Nonscaphoid carpal fractures occur more frequently than previously reported and demonstrate variable age distribution, treatment rates, and nonunion risks. Understanding these patterns can improve diagnosis, guide treatment planning, and inform patient expectations. IV.

ABSTRACT Extracellular vesicles (EVs) are non‐replicating, lipid membrane‐bound nanoparticles released by most eukaryotic cells into the extracellular space. When derived from platelets, a subset of EVs can exhibit remarkable anti‐inflammatory and antioxidant properties, making them attractive candidates to attenuate sterile inflammatory states such as limb skeletal muscle ischaemia‐reperfusion injury (IRI). Peripheral extremity IRI complicating acute limb revascularisation procedures, replantation of major traumatic amputations and limb allotransplants can trigger a life‐threatening reperfusion syndrome that leads to multi‐organ system failure and death. In this study, we used a platelet‐derived EVs‐enriched preparation as a therapeutic strategy for extremity IRI. To allow for a clinically translatable drug delivery strategy, we established and validated a catheter‐directed regional intra‐arterial limb infusion (RLI) delivery approach that permitted selective and effective targeting of pEVs to limb skeletal muscles and soft tissues in the vascularly isolated rodent extremity simulating pre‐reperfusion preservation and revascularisation conditions of the ischaemic or amputated extremity. In addition to being safe and feasible, we demonstrated robust retention of EVs by skeletal muscles of the operative limb during the early critical phase of reperfusion injury following RLI. We also show that pretreatment of ischaemic skeletal muscles using an pEVs‐enriched formulation just before reestablishing extremity blood flow alleviated metabolic derangements and suppressed the systemic and localised proinflammatory cytokine response associated with skeletal muscle reperfusion and reduced histologic markers of myofibre injury without adverse effects on serum chemistries. This work opens a new perspective to investigate novel approaches for regional delivery of therapeutic pEVs to skeletal muscle to mitigate limb IRI in vivo, and to achieve both in situ and ex vivo targeted delivery of nanocarriers to the isolated limb tissue for other therapeutic applications.

Abstract To present our clinical experience with a volar scapholunate (SL) ligament reconstruction using a strip of the long radiolunate ligament. This was a single-institution observational study (2004–2022) of SL ligament injuries with evidence of a torn volar component on arthroscopy that received volar capsulodesis with/without a dorsal repair. The postoperative range of motion (ROM), grip strength, complications, and secondary surgery (e.g., four-corner fusion or total wrist fusion), and radiographic changes were reported. Disabilities of arm, shoulder, and hand/patient-rated wrist evaluation (DASH/PRWE) scores were prospectively collected. Patients were stratified by static versus dynamic/predynamic SL diastasis and by isolated volar versus volar and dorsal ligament injury. Twenty-eight patients (15 females and 13 males) with a mean age of 35.1 years (± 15.7) met the inclusion criteria. The follow-up was 86.3 months (± 53.4; minimum 11 months). Most (26/28) patients were right-handed. The majority (20/28) of the patients presented ≥ 6 weeks postinjury. Few (4/28) used tobacco. Most (20/28) patients had dynamic/predynamic injuries. Postoperatively, the mean pronation/supination was 83 degrees/83 degrees, flexion/extension was 56 degrees/61 degrees, ulnar deviation was 30 degrees, and radial deviation (RD) was 19 degrees (n = 13). The mean grip strength was 78.8% (± 30.4) of the contralateral normal side (n = 14). Except for increased RD in patients with dynamic/predynamic injuries (p = 0.02), there were no other ROM differences. SL widening (>3 mm) postoperatively was observed in 33.3% (2/6) of static versus none of the dynamic/predynamic injuries (p = 0.165). There were only two postoperative complications, both surgical site infections. Two patients had persistent pain and required secondary surgery at a median of 48 months. At 86.9 months, patients reported a mean DASH of 16.4 (± 17.8) and a PRWE of 24.6 (± 23.6), and 78.9% (15/19) returned to prior work. We report long-term functional outcomes after a volar capsulodesis for volar SL injuries. This appears to be a safe procedure with an acceptable complication rate and low disability after 7 years. Most (approximately 79%) patients returned to their previous employment. A larger comparative study will be required to prove superiority to other types of repairs. Level IV, Case series.

Abstract Objective Sleeper stretching (SS) and cross‐body stretching (CS) are common nonsurgical interventions for the management of glenohumeral internal rotation deficit (GIRD) in overhead athletes such as baseball and volleyball players. However, the effectiveness of these stretching interventions in enhancing the range of motion (ROM) of shoulder internal rotation (IR) in overhead athletes with GIRD remains a subject of uncertainty. This systematic review and meta‐analysis aim to critically assess the efficacy of SS and CS in the ROM of the IR among overhead athletes with GIRD, thereby providing evidence‐based recommendations for their use. Literature Survey A comprehensive search of MEDLINE, Embase, and Scopus databases up to November 2024 was conducted to identify randomized controlled trials investigating the influence of SS and CS on the ROM of shoulder IR in overhead athletes with GIRD. Methodology Data including study characteristics and outcomes were extracted. Risk of bias assessment and random‐effects model meta‐analysis were performed. Synthesis Six eligible studies involving 255 athletes with GIRD were included. The meta‐analysis demonstrated statistically significant differences between stretching and control groups in terms of enhancing the ROM of IR (mean difference [MD], 7°; 95% confidence interval [CI], 1°–13°; p = .02) and horizontal adduction (HAD) ([MD], 6°; [CI], 1°–11°; p = .03). Conclusion SS or combination of SS and CS interventions significantly enhanced the ROM of IR compared to the control group in overhead athletes diagnosed with GIRD. Furthermore, the review confirmed that SS alone also markedly enhances the ROM of HAD. These findings highlight the potential benefits of SS and CS in managing GIRD and suggest a need for further research to optimize these interventions for broader application in overhead athletes.

Abstract Rhabdomyolysis following revascularization of the ischemic upper extremity can lead to life- & limb- threatening sequelae. In the context of replantations and vascularized composite allografting, a reconstructive procedure usually reserved for upper limb amputees, prolonged tissue ischemia is detrimental to extremity functional recovery. Currently, validated survival small animal models of extremity reperfusion injury that permit longitudinal assessment of limb function are lacking. To date, studies that evaluated reperfusion injury-induced neuromuscular impairment rely on terminal ex vivo procedures and do not provide clinically translatable measurements. Furthermore, it is unclear if upper extremity musculature exhibits a different ischemic threshold compared to the lower limb given the relatively rare incidence of upper limb ischemia. Here, we present a reliable rat model of extremity post-reperfusion syndrome (PRS) that comprehensively recapitulates the biochemical hallmarks of rhabdomyolysis secondary to upper extremity reperfusion injury and allows for monitoring in vivo upper limb function using clinically relevant electrodiagnostic and kinematic metrics. In addition to inducing severe metabolic derangements, our forelimb PRS provided insights on gross motor and electrophysiological alterations upper extremity reperfusion injury. We identify gait coordination parameters such as stride frequency and forelimb-hindlimb coordination index and electrophysiological metrics including compound muscle action potential amplitude as objective, non-invasive outcome measures for limb function assessment in small animal models of extremity PRS. This comprehensive, validated functional model can serve as an invaluable tool to evaluate therapeutics or preconditioning regimens to attenuate PRS and mitigate resulting neuromuscular dysfunction.

Muscle stem cells (MuSCs) are essential for skeletal muscle regeneration, influenced by a complex interplay of mechanical, biochemical, and molecular cues. Properties of the extracellular matrix (ECM) such as stiffness and alignment guide stem cell fate through mechanosensitive pathways, where forces like shear stress translate into biochemical signals, affecting cell behavior. Aging introduces senescence which disrupts the MuSC niche, leading to reduced regenerative capacity via epigenetic alterations and metabolic shifts. Transplantation further challenges MuSC viability, often resulting in fibrosis driven by dysregulated fibro-adipogenic progenitors (FAPs). Addressing these issues, scaffold designs integrated with pharmacotherapy emulate ECM environments, providing cues that enhance graft functionality and endurance. These scaffolds facilitate the synergy between mechanotransduction and intracellular signaling, optimizing MuSC proliferation and differentiation. Innovations utilizing human pluripotent stem cell-derived myogenic progenitors and exosome-mediated delivery exploit bioactive properties for targeted repair. Additionally, 3D-printed and electrospun scaffolds with adjustable biomechanical traits tackle scalability in treating volumetric muscle loss. Advanced techniques like single-cell RNA sequencing and high-resolution imaging unravel muscle repair mechanisms, offering precise mapping of cellular interactions. Collectively, this interdisciplinary approach fortifies tissue graft durability and MuSC maintenance, propelling therapeutic strategies for muscle injuries and degenerative diseases.

Abstract Flexor tendon injury is a common hand trauma that requires surgical repair. The objective was to compare the repaired strength and gliding resistance with a varied number of repair strands and of square knots using a two‐strand‐overhand locking (TSOL) knot. First, isolated suture loops with different number of suture strands and number of closing knots were compared in mechanical strength and failure mode. Then, 90 flexor digitorum profundus (FDP) tendons from turkey digits were used for the tendon repair experiment. Both phases followed a similar 3 × 3 matrix comparing the knot type including TSOL+1SK (square knot), TSOL+2SK, and TSOL+3 SK and repair techniques including two‐, four‐, and six‐strand repairs techniques respectively. The repaired tendons were tested for tendon resistance against pulley (friction), maximum force, force at 2 mm displacement, stiffness, and failure mode. Increasing the number of strands and closing square knots increases the tensile strength and stiffness of flexor tendon repairs and isolated suture loops without a significant effect on tendon friction. An increase in the number of square knots have shown increased strength only in Pennington repair, which correlated with the increased number of knot unraveling, a weak knot failure model. Our data demonstrated that increasing the number of strands is effective for improving the overall strength of tendon repair. When a two‐strand repair is chosen, increasing knot number can improve repair strength. However, the number of knots appears not affecting repair strength in six‐strand repair technique.

ABSTRACT Introduction Acute Compartment Syndrome (ACS) is a severe trauma caused by elevated intra-muscle-compartment pressure (ICP). The current standard method for diagnosis is to insert a needle into the muscle sterilely under anesthesia. However, to secure the environment is sometimes not easy and leads to delays in diagnosis. Recently, we have focused on shear wave ultrasound elastography (SWE) as an alternative, which can be done concisely in unclean environment and without anesthesia. We would like to report the usefulness of SWE for ACS diagnosis using 2-pedal walking turkey model recently developed in our lab. Materials and Methods A total of 32 1-year-old Bourbon turkeys were used. 5% solution of chicken albumin was infused continuously into the tibialis cranialis (TC) muscle using IV pump. The ICP was increased stepwise from 0 to 50 mmHg. During the rising of ICP, the correlation between values of SWE (kPa) and ICP (mmHg) was measured. After the ICP reached 50 mmHg, half of the turkeys were maintained at this pressure for 2 hours and the rest for 6 hours. After infusion, a fasciotomy was performed on the half turkey. Half of the turkeys were euthanized after 2 weeks and the rest after 6 weeks. SWE of TC muscle and walking gait data on turkeys using a portable walkway system were measured weekly until euthanasia. At euthanasia, isometric tetanic muscle force (ITF) tests to TC muscle and histological evaluations were performed. Results SWE value (kPa) was highly significantly correlated to the actual ICP (mmHg) (R2 = 0.91). Stance of ACS side leg were significantly extended, and swing of the control side shortened from the second to the third week after ACS in the 6 hours infusion-no-fasciotomy group (P < 0.05*). ITF was significantly reduced mainly in the 6 hours infusion group (P < 0.05*). Histological evaluation revealed that in the 6 hours infusion and 6 weeks survival group, both the muscle fiber and intercellular distances were significantly expanded (P < 0.05). Conclusion SWE seems to be a substitute measure of ICP in diagnosing ACS. With regard to our in vivo ACS model using turkey, survival at 50 mmHg ICP for 6 hours and 6 weeks post ACS would be an appropriate situation.