Extreme resilience and dissipation in heterogeneous elasto-plastomeric crystals.

We present a microstructure-topology-based approach for designing macroscopic, heterogeneous soft materials that exhibit outstanding mechanical resilience and energy dissipation. We investigate a variety of geometric configurations of resilient yet dissipative heterogeneous elasto-plastomeric materials that possess long-range order whose microstructural features are inspired by crystalline metals and block copolymers. We combine experiments and numerical simulations on 3D-printed prototypes to study the extreme mechanics of these heterogeneous soft materials under cyclic deformation conditions up to an extreme strain of >200% with strain rates ranging from quasi-static (5.0 × 10-3 s-1) to high levels of >6.0 × 101 s-1. Moreover, we investigate the complexity of elastic and inelastic "unloading" mechanisms crucial for the understanding of shape recovery and energy dissipation in extreme loading situations. Furthermore, we propose a simple but physically intuitive approach for designing microstructures that exhibit a nearly isotropic behavior in both elasticity and inelasticity across different crystallographic orientations from small to large strains. Overall, our study sets a significant step toward the development of sustainable, heterogeneous soft material architectures at macroscopic scales that can withstand harsh mechanical environments.

A Comparative Analysis of Pain Control Methods after Ankle Fracture Surgery with a Peripheral Nerve Block: A Single-Center Randomized Controlled Prospective Study.

Background and Objectives: Patients experience severe pain after surgical correction of ankle fractures. Although their exact mechanism is unknown, dexamethasone and epinephrine increase the analgesic effect of anesthetics in peripheral nerve blocks. This study aimed to compare the postoperative pain control efficacy of peripheral nerve blocks with ropivacaine combined with dexamethasone/epinephrine and peripheral nerve blocks with only ropivacaine and added patient-controlled analgesia in patients with ankle fractures. Materials and Methods: This randomized, controlled prospective study included patients aged 18-70 years surgically treated for ankle fractures between December 2021 and September 2022. The patients were divided into group A (n = 30), wherein pain was controlled using patient-controlled analgesia after lower extremity peripheral nerve block, and group B (n = 30), wherein dexamethasone/epinephrine was combined with the anesthetic solution during peripheral nerve block. In both groups, ropivacaine was used as the anesthetic solution for peripheral nerve block, and this peripheral nerve block was performed just before ankle surgery for the purpose of anesthesia for surgery. Pain (visual analog scale), patient satisfaction, and side effects were assessed and compared between the two groups. Results: The patients' demographic data were similar between groups. Pain scores were significantly lower in group B than in group A postoperatively. Satisfaction scores were significantly higher in group B (p = 0.003). There were no anesthesia-related complications in either group. Conclusions: Dexamethasone and epinephrine as adjuvant anesthetic solutions can effectively control pain when performing surgery using peripheral nerve blocks for patients with ankle fractures.

Difference in Joint Stability Between Small Posterior Malleolar Fragments With Fixation and Those Without Fixation: A Biomechanical Cadaver Study.

The indication for the surgical treatment of ankle fractures that involve a posterior malleolar fragment remains controversial. This cadaver study assessed the biomechanical results of rotation stiffness of Haraguchi type 1 posterior malleolar fragments with or without cannulated screw fixation. Twelve anatomic lower-extremity specimens from 6 cadavers were tested. Six right legs were subjected to posterior malleolus osteotomy (Haraguchi type I) followed with (group A; n = 3) or without (group B; n = 3) fixation using a cannulated screw. Ankle joint stability was measured under both external rotation force and axial loading, and the passive resistive torque was measured in both groups. The mean torque value in group A was 0.1093 Nm/º, while that in group B was 0.0537 Nm/º. There was a significant intergroup difference (p = .004). In group B, the torque value was further increased in the latter rotation period (about 40-60 degrees). Group A proved more stable under experimental conditions than group B. Fixation in type I posterior malleolar fragments produced improved stability in ankle rotation, even for posterior malleolar fragments involving <25% of the articular surface, and has been considered an effective aid in treatment.

Clinical analyses of ultrasound-guided nerve block in lower-extremity surgery: A retrospective study.

PURPOSE: The purpose of this study is to examine the clinical effects and results of lower-extremity surgery under ultrasound-guided nerve block; time required for nerve block, anesthesia onset time, duration of anesthesia, duration of analgesia, tolerable tourniquet time, visual analog scale (VAS) satisfaction score, and anesthetic-related complications. METHODS: A total of 3312 cases (2597 patients) from January 2010 to April 2015 were analyzed retrospectively. A senior author performed ultrasound-guided nerve block of the lateral femoral cutaneous nerve (LFCN, 630 cases), femoral nerve (FN, 2503 cases), obturator nerve (ON, 366 cases), sciatic nerve (SN, 3271 cases), or posterior femoral cutaneous nerve (PFCN, 222 cases) depending on the type of surgery. Time required for nerve block, anesthesia onset time, duration of anesthesia, duration of analgesia, tolerable tourniquet time, VAS satisfaction score, and anesthetic-related complications were analyzed. RESULTS: The mean times required were 1.1 min for SN block, 2.5 min for FN/SN block (1762 cases), and 4.8 min for FN/SN/LFCN/ON block. The mean anesthesia onset time was 48 min. The mean durations of anesthesia were 4.5 h for FN dermatome and 5.6 h for SN dermatome. The mean duration of analgesia was 11.5 h. The mean tolerable tourniquet times after were 35, 51, and 84 min after SN block, FN/SN block, and FN/SN/LFCN/ON block, respectively. The mean VAS satisfaction score was 9.3. There were no anesthetic-related complications, such as infection, hematoma, paralysis, or nerve irritation. CONCLUSION: Selective block of the LFCN, FN, ON, SN, and PFCN based on the locations of lesions and type of surgery showed favorable clinical results with high efficacy. Ultrasound-guided nerve block may be a good option for anesthesia and analgesia in lower-extremity surgery.

The role and clinical relevance of the ligamentum teres: long-term outcomes after hip arthroscopic surgery of cam-type femoroacetabular impingement.

We aimed to compare clinical and radiologic outcomes in patients with cam-type femoroacetabular impingement (FAI), with and without a partial ligamentum teres (LT) tear, who underwent hip arthroscopy (HA) with ≥10 years of follow-up. Among the patients who underwent HA for a cam-type FAI diagnosis with a labral tear, 28 patients (28 hips) with a partial LT tear and 87 patients (99 hips) with an intact LT were assigned to Groups A and B, respectively. All patients underwent partial labral debridement and femoroplasty. Debridement and thermal shrinkage were performed for LT tears. The grade of chondral damage was measured intraoperatively. Clinical items were assessed preoperatively and at the last follow-up. Patients' satisfaction with the surgery and changes in postoperative sports ability in those who had previously been active in sports were assessed at the last follow-up. The Tönnis grade was assessed preoperatively and at the last follow-up for radiologic evaluation. Chondral damage to the acetabular and femoral head detected intraoperatively was significantly different between the groups (P = 0.005 and P < 0.001). At the last follow-up, Group A patients experienced more difficulty performing sports activities than Group B patients (P = 0.056), and significantly, more Group A patients had stopped exercising despite their active participation in sports preoperatively (P = 0.002). Regarding the Tönnis grade, significant differences were found only at the final follow-up (P = 0.020). Patients with partial LT tear showed a higher grade of chondral damage, experienced decreased exercise capacity and had significantly worsened Tönnis grades, suggesting hip osteoarthritis progression compared to those with an intact LT.

Flexible Intramedullary Nailing in High-Energy Tibial Fractures With Extensive Soft-Tissue Loss: A Case Report.

CASE REPORT: An 83-year-old woman presented with a high-energy tibial fracture. We treated her with temporary external fixation and delayed flexible intramedullary nailing because of extensive soft-tissue damage and interference from the hardware retained from a previous total knee arthroplasty. CONCLUSIONS: In our opinion, flexible intramedullary nailing is an effective procedure and provides good functional and radiological results in high-energy tibial fractures with extensive soft-tissue loss.

Midterm-clinical Outcomes after Hip Arthroscopy in Middle-aged Patients with Early Osteoarthritis.

PURPOSE: Although the number of hip arthroscopies is rapidly increasing in non-elderly patients, outcomes of this procedure in middle-aged patients are not well documented or clearly understood. The purpose of this study was to evaluate the clinical and radiological outcomes after hip arthroscopy in middle-aged patients with early osteoarthritis. MATERIALS AND METHODS: This retrospective study analyzed 189 patients with early osteoarthritis of various diagnoses aged 40 years or older who underwent hip arthroscopy between January 2010 and December 2015. Clinical (e.g., modified Harris hip score [mHHS], hip outcome score-activities of daily living [HOS-ADL], visual analogue scale [VAS] for pain, range of motion) and radiological (change of Tönnis grade) outcomes were assessed at a minimum of 3-year follow-up. RESULTS: The mean preoperative and final mHHS and HOS-ADL improved from 61.2 and 60.6 to 79.5 and 81.8, respectively, while the VAS pain score decreased from 6.3 to 3.2 (P<0.001). Although the mean range of internal rotation and flexion increased from 14.2 and 100.7° preoperatively to 30.4 and 110.6° at 1-year postoperatively, they decreased slightly to 27.4 and 105.4° at the final follow-up, respectively. Eight cases (4.2%) underwent revision arthroscopic surgery and three cases (1.6%) were converted to total hip arthroplasty. CONCLUSION: Patients with early-stage osteoarthritis of various diagnoses achieved improved clinical outcomes. Therefore, using hip arthroscopy in middle-aged patients with early osteoarthritis, it is possible to achieve good surgical options.

A comparative study of innovative percutaneous repair and open repair for acute Achilles tendon rupture: Innovative usage of intraoperative ultrasonography.

PURPOSE: There is no definitive consensus on the optimal treatment of Achilles tendon rupture. We comparatively analyzed the clinical outcomes of two types of repair surgeries in treating Achilles tendon rupture. METHODS: This retrospective study included 12 patients of Achilles tendon rupture (group A) treated with ultrasound-guided percutaneous repair and 18 patients (group B) treated with open repair. Clinical evaluation was performed using the Arner-Lindholm scale, American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, Achilles Tendon Total Rupture score (ATRS), visual analog scale, time to single heel raise, bilateral calf circumferences, recovery of athletic ability, and other complications. RESULTS: While the Arner-Lindholm scale, AOFAS ankle-hindfoot score, ATRS, time point when single heel raise was possible, differences in bilateral calf circumference, and recovery of athletic ability compared to pre-rupture level were not significantly different between the two groups (p = 0.999, 0.235, 0.357, 0.645, 0.497, and 0.881, respectively), overall and aesthetic satisfaction levels were higher in the group treated with percutaneous repair under ultrasonography guidance (p = 0.035 and 0.001, respectively). Overall, there were no cases involving sural nerve injury in either group. CONCLUSION: Innovative percutaneous repair provides not only similar clinical outcomes but also greater overall and aesthetic satisfaction levels of operative outcomes and minimal complications (i.e. sural nerve injury) compared to open repair surgeries. Therefore, percutaneous repair may be a useful technique in the treatment of Achilles tendon rupture.

An Innovative Pain Control Method Using Peripheral Nerve Block and Patient-Controlled Analgesia With Ketorolac After Bone Surgery in the Ankle Area: A Prospective Study.

Although postoperative pain is inevitable after bone surgery, there is no general consensus regarding its ideal management. We hypothesized that the combination of ultrasound-guided peripheral nerve block (PNB) and patient-controlled analgesia (PCA) with ketorolac would be useful for pain control and reducing opioid usage. This prospective study aimed to evaluate the effectiveness of this method. This study included 95 patients aged >18 years who underwent bone surgery in the ankle area from June to December 2018. All operations were performed under anesthetic PNB, and additional PNB was given for pain control ∼11 hours after preoperative PNB. An additional PCA with ketorolac, started before rebound pain was experienced, was used for pain control in group A (49 patients) but not group B (46 patients). We used intramuscular injection with pethidine or ketorolac as rescue analgesics if pain persisted. A visual analogue scale (VAS) for pain was used to quantify pain at 6, 12, 18, 24, 36, 48, and 72 hours postoperatively. Patient satisfaction was assessed, along with side effects in both groups. VAS pain scores differed significantly between the groups at 24 hours after the operation (p = .013). All patients in group A were satisfied with the pain control method; however, 5 patients in group B were dissatisfied (p = .001), 3 owing to severe postoperative pain and 2 owing to postoperative nausea and vomiting. An average of 0.75 and 11.40 mg pethidine per patient was used in groups A and B, respectively, for 3 days. We concluded that the combined use of ultrasound-guided PNB and PCA with ketorolac can be an effective postoperative method of pain control that can reduce opioid usage.

Arthroscopic Treatment for Femoroacetabular Impingement with Extraspinal Diffuse Idiopathic Skeletal Hyperostosis.

BACKGROUND: Patients with extraspinal diffuse idiopathic skeletal hyperostosis (DISH) involving the hip joint have symptoms like femoroacetabular impingement (FAI). To date, no reported study has determined the clinical outcomes of arthroscopic treatment in extraspinal DISH involving the hip joint. METHODS: A total of 421 hips with FAI that underwent arthroscopic treatment were reviewed retrospectively. We determined the extraspinal involvement of DISH with three-dimensional computed tomography (3D-CT) and simple radiography of the pelvis and hip joint. Clinical outcomes were evaluated at a minimum of 2 years postoperatively. The visual analog scale score (VAS), modified Harris hip score (MHHS), and hip outcome score-activity of daily living scale (HOS-ADL) were used, and hip range of motion (ROM) was evaluated pre- and postoperatively and at the time of the final follow-up. RESULTS: Among the 421 hips (372 patients) with FAI that underwent arthroscopic treatment, 17 hips (12 patients, 4.04%) had extraspinal DISH on the hip joints. The mean age of the patients was 51.5 years. The 3D-CT scans and simple radiographs showed extraspinal DISH on multiple points around the pelvis and hip joint. Nine of the 17 hips (seven of 12 patients) had spinal DISH. At the final follow-up, VAS, MHHS, and HOS-ADL improved significantly from 6.5, 65.3, and 66.6, respectively, to 1.2, 87.8, and 89.5, respectively, and hip flexion and internal rotation improved significantly from 97.7° and 7.9°, respectively, to 117.1° and 18.2°, respectively. CONCLUSIONS: This study has demonstrated that extraspinal DISH involving the hip joint could lead to FAI, and arthroscopic treatment could result in relief of symptoms, including pain and ROM limitation, in extraspinal DISH patients.

Screw Fixation of the Posterior Malleolus Fragment in Ankle Fracture.

BACKGROUND: This study aimed to evaluate the outcomes of ankle fractures with posterior malleolus fragments (PMFs) involving <25% of the articular surface treated with or without screw fixation. METHODS: Among patients with ankle fractures and PMFs who underwent surgery between March 2014 and February 2017, 62 with type 1 PMFs involving <25% of the articular surface were included. Of these 62 patients, 32 underwent screw fixation for PMFs and lateral and/or medial malleolar fracture fixation (group A) and 30 underwent internal fixation for malleolar fractures without screw fixation for PMFs (group B). Ankle joint alignment and fracture healing were measured using plain radiography and computed tomography (CT). Clinical outcomes were determined using the American Academy of Orthopaedic Surgeons Foot and Ankle Questionnaire, Short Form-36, and American Orthopaedic Foot & Ankle Society Scale. RESULTS: Nonunion was not noted in either group. However, we detected union with a step-off of 2 mm or more in 2 cases from group B. With regard to ankle joint alignment, 1 case in group A and 3 cases in group B showed mild asymmetry of the medial and lateral clear spaces on CT at 12 months. Clinical outcomes at 6 and 12 months after surgery were better in group A than in group B. CONCLUSION: Screw fixation of PMFs was effective for fracture healing and maintaining ankle alignment. Additionally, it improved short-term clinical outcomes, which we believe was due to stabilization of ankle fractures with PMFs involving <25% of the articular surface. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Improved functional outcome after early reduction in Bosworth fracture-dislocation.

BACKGROUND: Bosworth described an unusual fracture-dislocation of the ankle with fixed posterior fracture-dislocation of the fibula. Previous epidemiological data on the prevalence and characteristics of patients with Bosworth ankle fractures have been limited. Bosworth fracture-dislocations are often missed in patients with ankle fractures. We investigated the outcomes of missed diagnosis and the prevalence of Bosworth fracture-dislocation in patients with ankle fractures. METHODS: We conducted a retrospective analysis of inpatients aged 15 years and older with an ankle fracture, who underwent surgery between 2007 and 2016 in 4 Korean hospitals. The patient demographics, risk factors, fracture characteristics, treatment data, outcomes, and complications were analyzed. RESULTS: We reviewed 3405 hospital admissions for ankle fractures. During the study period, Bosworth fracture-dislocations were diagnosed in 51 cases. The prevalence of Bosworth fracture-dislocations (n=51) was 1.62% among patients with ankle fractures who were enrolled in this study (n=3140). Emergency surgery was performed within 24h of injury in 36 cases (group A) and delayed surgery was performed in 15 cases (group B). The mean patient age at admission was 35.97 (standard deviation [SD], 1.643) years in group A and 34.33 (SD, 2.296) years in group B. Men were more commonly affected than women, with a 32:19 ratio. Most of the patients with Bosworth fracture-dislocations were young adults with high-energy trauma. The most frequent mechanism of trauma was falling down stairs (n=27, 52.94%), followed by traffic accidents. Patient outcomes were significantly better in group A than in group B. CONCLUSION: The prevalence of Bosworth fracture-dislocations was higher than expected. If unrecognized, it can result in inappropriate treatment and permanent disability. With accurate diagnosis and prompt treatment, excellent results can usually be obtained. LEVEL OF CLINICAL SIGNIFICANCE: 4.

Comparison of postoperative pain control methods after bony surgery in the foot and ankle.

BACKGROUND: We performed a prospective study to evaluate and compare the effectiveness of postoperative pain control methods after bone surgery in the foot and ankle. METHODS: Among the patients who underwent foot and ankle surgery from June 2014 to September 2015 with an ultrasound-guided nerve block, 84 patients who fully completed a postoperative pain survey were enrolled. An opioid patch (fentanyl patch, 25mg) was applied in group A (30 patients). Diluted anesthetic (0.2% ropivacaine, 30ml) was injected into the sciatic nerve once, about 12h after the preoperative nerve block, in group B (27 patients). Periodic intramuscular injection of an analgesic (ketorolac [Tarasyn], 30mg) was performed in group C (27 patients). The visual analogue scale (VAS) pain scores at 6, 12, 18, 24, and 48h after surgery were checked, and the complications of all methods were monitored. RESULTS: The mean VAS pain score was lower in group B, with a statistically significant difference (P<.05) between groups A, B, and C at 12 and 18h after surgery. Four patients in group A experienced nausea and vomiting; however, no other patients complained of any complications or adverse effects. CONCLUSION: The ultrasound-guided injection of a diluted anesthetic into the sciatic nerve seemed to be the most useful method for controlling pain in the acute phase after bone surgery in the foot and ankle. The injection of the diluted anesthetic once on the evening of the day of surgery resulted in less postoperative pain in the patients. LEVEL OF EVIDENCE: II.

Comparison of Time to Operation and Efficacies of Ultrasound-Guided Nerve Block and General Anesthesia in Emergency External Fixation of Lower Leg Fractures (AO 42, 43, 44).

The present randomized controlled trial evaluated the usefulness of ultrasound (US)-guided nerve block (NB) for emergency external fixation of lower leg fractures, by investigating the time required before surgery and the clinical results stratified by the anesthesia method (US-guided NB or general anesthesia [GA]). From June 2014 to April 2016, 40 patients who had undergone emergency surgery for external fixator application were enrolled in the present study. We measured the lead time before the start of surgery after the decision to perform emergency surgery in both groups. The US-guided NB group included 17 males (85%) and 3 females (15%), with a mean age of 55.6 (range 33 to 77) years. Of these 20 patients, 12 (60%) had comorbidities such as diabetes mellitus, hypertension, and kidney-related disease. Fracture type 42, 43, and 44 in the AO classification were observed in 3 (15%), 12 (60%), and 5 (25%) cases, respectively. The mean interval before emergency surgery was 4.3 (range 2 to 6.25) hours in the US-guided NB group. In the GA group (n = 20 patients), the mean interval before emergency surgery was 9.4 (range 3 to 14) hours, and this difference was statistically significant (p < .001). In the US-guided NB group, no cases of anesthesia failure or unstable vital signs occurred during surgery. Also, no postoperative complications related to the anesthesia method, such as aggravation of the general condition, developed. In contrast, 1 case of postoperative atelectasis occurred in the GA group. Emergency external fixation with US-guided NB in patients with lower extremity trauma can be implemented in less time, regardless of the preoperative preparation, which is a requirement for GA.

Clinical Results of Complex Subtrochanteric Femoral Fractures with Long Cephalomedullary Hip Nail.

PURPOSE: Good results of the cephalomedullary nails have been reported in proximal femoral fractures recently. Based on length of nails and shape of screws fixed in a femoral head for proximal fragment fixation, the proper nail length was in dispute. The purpose of this study was to evaluate the clinical and radiological results of a long cephalomedullary hip nail for the treatment of comminuted subtrochanteric femoral fractures. MATERIALS AND METHODS: Twenty-one consecutive patients with severe subtrochanteric femoral fractures who had undergone intramedullary fixation using long-PFNA II between March 2010 and March 2013 were followed-up for over 12 months. Their mean age was 64.8 years old (range, 43-85 years). Sixteen of 22 cases were high energy trauma. According to Seinsheimer's classification, 5 cases were type IV and 16 cases were type V. For radiological assessment, time to union, change of neck-shaft angle, sliding length, tip-apex distance (TAD) and leg length discrepancy (LLD) were measured. For clinical evaluation, a modified Koval index was investigated. RESULTS: Mean operation time was 96 minutes. An average decrease of neck-shaft angle was 4.5°. The average sliding length of the helical blade was 4.2 mm. Average LLD was 3.0 mm, and TAD was 23.0 mm. Mean modified Koval index score at final follow-up was 4.6 points. All the 21 subtrochanteric fractures healed uneventfully on an average of 24.2 weeks (range, 18-30 weeks). CONCLUSION: Long cephalomedullary hip nail provides excellent clinical and radiological outcomes in the comminuted subtrochanteric fracture.

Unilateral Spinous Process Noncovering Hook Type Patient-specific Drill Template for Thoracic Pedicle Screw Fixation: A Pilot Clinical Trial and Template Classification.

STUDY DESIGN: Prospective clinical pilot study. OBJECTIVE: To confirm the accuracy of thoracic pedicle screw placement by using the unilateral spinous noncovering hook type patient-specific drill template (PSDT) made through rapid prototyping (RP) and to analyze previously reported PSDT designs and their characteristics. SUMMARY OF BACKGROUND DATA: Pedicle screw fixation is the most common form of the posterior instrumentation of the thoracic and lumbar spine. Various techniques have been introduced to improve pedicle screw placement. Among them PSDT with a preplanned trajectory has been considered a promising solution; however, we don't have consensus on proper character of the template. METHODS: Preoperative spiral three-dimensional (3D) computed tomography (CT) was performed on the thoracic spine. The images were stored in DICOM format and transferred to a workstation running MIMICS 17.0 software to generate a 3D reconstruction template for the desired thoracic vertebra. The accurate trajectory and screw diameter and length were calculated with UG Imageware 12.1. The guide template was sterilized and used intraoperatively to assist with the placement of thoracic pedicle screws. After all pedicle trajectory screws had been inserted. We reviewed 12 previous reports and classified them according to the shape and system of PSDT that met the inclusion criteria of the review. RESULTS: Ten screws were placed by using the PSDT without violating the single laminar cortex. There was no violation of the spinal canal or the cortex of pedicle on postoperative CT scans. The results of 13 PSDT types included in the current study suggested that there is no significant difference in accuracy between the PSDTs. CONCLUSION: The unilateral spinous process noncovering hook type PSDT made through RP provided an accurate trajectory for the thoracic vertebra, and the classification of PSDT in this study could be helpful for further studies. LEVEL OF EVIDENCE: 5.

Arthroscopic Treatment of Subchondral Bony Cyst in Early Osteoarthritis of the Hip Joint Using Allogeneic Bone Graft: A Report of Two Cases.

Subchondral bony cyst, large solitary or multiple cysts in acetabular dome usually exacerbate progression to degenerative osteoarthritis in the hip joint. But it can be treated through arthroscopic intervention. We report two cases that treated by arthroscopic curettage and bone graft for subchondral bony cysts in early osteoarthritis of the hip joint, and it may delay progression to moderate osteoarthritis.