Three dimension printing talar prostheses for total replacement in talar necrosis and collapse.

BACKGROUND: Reconstructing bone structures and stabilizing adjacent joints are clinical challenges in treating talar necrosis and collapse (TNC). 3D printing technology has been demonstrated to improve the accuracy of talar replacement. This study aimed to evaluate anatomical talar replacement and the clinical results. METHODS: Nine patients with TNC were enrolled between 2016 and 2020. The prosthetic shape and size were designed by CT post-processing and mirror symmetry technology. The clinical outcomes included radiographic parameters of the forefoot, hindfoot, and ankle alignment, ankle activity, recurrent pain, and peri-operative complications. RESULTS: After a mean follow-up of 23.17 ± 6.65 months, degenerative arthritis and prosthetic dislocation and other complications were not observed on plain radiographs. Each 3D-printed talar prosthesis was placed in the original anatomical position. The parameters which have significant changes pre-operative and post-operative are as follows: talar height, 27.59 ± 5.99 mm and 34.56 ± 3.54 mm (95% CI - 13.05 to - 0.87, t = 2.94, P = 0.032) and Meary's angle, 11.73 ± 4.79° and 4.45 ± 1.82° (95% CI 1.29~22.44, t = 2.89, P = 0.034). The AOFAS hindfoot score improved from 26.33 ± 6.62 to 79.67 ± 3.14 at the final follow-up (95% CI 43.36~63.30, t = 13.75, P = 0.000). The VAS score decreased from 6.33 ± 1.03 to 0.83 ± 0.75 (95% CI 4.40~6.60, t = 12.84, P = 0.000). The post-operative satisfaction scores regarding pain relief, activities of daily living, and return to recreational activities were good to excellent, and the change of activity range was statistically significant. CONCLUSIONS: The 3D printing patient-specific total talar prostheses allowed anatomical reconstruction in TNC. This novel treatment with 3D-printed prostheses could serve as a reliable patient-specific alternative in TNC.

Interleukin-15 facilitates muscle regeneration through modulation of fibro/adipogenic progenitors.

BACKGROUND: Chronic muscle injury is characteristics of fatty infiltration and fibrosis. Recently, fibro/adipogenic progenitors (FAPs) were found to be indispensable for muscular regeneration while were also responsible for fibrosis and fatty infiltration in muscle injury. Many myokines have been proven to regulate the adipose or cell proliferation. Because the fate of FAPs is largely dependent on microenvironment and the regulation of myokines on FAPs is still unclear. We screened the potential myokines and found Interleukin-15 (IL-15) may regulate the fatty infiltration in muscle injury. In this study, we investigated how IL-15 regulated FAPs in muscle injury and the effect on muscle regeneration. METHODS: Cell proliferation assay, western blots, qRT-PCR, immunohistochemistry, flow cytometric analysis were performed to investigate the effect of IL-15 on proliferation and adipogensis of FAPs. Acute muscle injury was induced by injection of glycerol or cardiotoxin to analyze how IL-15 effected on FAPs in vivo and its function on fatty infiltration or muscle regeneration. RESULTS: We identified that the expression of IL-15 in injured muscle was negatively associated with fatty infiltration. IL-15 can stimulate the proliferation of FAPs and prevent the adipogenesis of FAPs in vitro and in vivo. The growth of FAPs caused by IL-15 was mediated through JAK-STAT pathway. In addition, desert hedgehog pathway may participate in IL-15 inhibiting adipogenesis of FAPs. Our study showed IL-15 can cause the fibrosis after muscle damage and promote the myofiber regeneration. Finally, the expression of IL-15 was positively associated with severity of fibrosis and number of FAPs in patients with chronic rotator cuff tear. CONCLUSIONS: These findings supported the potential role of IL-15 as a modulator on fate of FAPs in injured muscle and as a novel therapy for chronic muscle injury.

3D printing lunate prosthesis for stage IIIc Kienböck's disease: a case report.

Stage IIIc Kienböck's disease is a clinical challenge to treat collapse of the lunate bone. A new reconstructive surgery was described in one patient using 3D printing lunate prosthesis. The prosthesis shape was designed by tomographic image processing and segmentation using technology compared with the intact side matched by mirror symmetry and 3D post-processing technologies. The patient recovered nearly full range of motion of the wrist after 12 months. The visual analog scale scores and Cooney scores were 2 points and 91 points. We demonstrated that an anatomical reconstruction to Kienböck's Disease is possible using 3D printing lunate prosthesis.

[Virtual preoperative planning and 3D-printed templates for pre-contoured plates in treatment of acetabular posterior wall fractures].

OBJECTIVE: To evaluate the feasibility and accuracy of virtual preoperative planning and 3D-printed templates for pre-contoured plates for the treatment of posterior wall fractures of the acetabulum. METHODS: A retrospective analysis of 29 patients with posterior acetabular wall fractures treated between August 2017 and March 2021 were divided into 2 groups based on whether to use preoperative virtual planning and 3D printed template. In 3D-printing group, there were 14 patients, including 10 males and 4 females； aged from 21 to 53 years old；CT-based virtual surgical planning was done using Mimics and 3-Matic software and 3D-printed templates for pre-contoured plates were adopted. In conventional group, there were 15 patients, including 10 males and 5 females；aged from 19 to 55 years old；conventional method of intra-operative contouring to adapt the plate to the fracture region was adopted. Blood loss, surgical time, radiographic quality of reduction, and hip function were compared between groups. RESULTS: The difference in operation time and intraoperative blood loss was significant（P<0.05）. Twenty-three patients were followed up from 12 to 30 months, and the fractures in both groups healed with a healing time of 3 to 6 months. At the last follow-up, the Merle d'Aubign-Postel score of the 3D printed group was lower than that of the conventional group（P<0.05）, with no significant differences in walking ability, hip mobility and total score（P>0.05）. In 3D printing group, 6 cases were excellent, 5 cases were good, 3 cases were fair；in conventional group, 5 cases were excellent, 5 cases were good, 4 cases were fair, 1 case was worse；no significant difference between two groups（P>0.05）. CONCLUSION: Virtual preoperative planning and 3D-printed templates for pre-contoured plates can reduce operative time and the blood loss of surgery, improve the quality of reduction. This method is efficient, accurate and reliable to treat acetabular posterior wall fractures.

Mechanisms of Neuronal Reactivation in Memory Consolidation: A Perspective from Pathological Conditions.

Memory consolidation refers to a process by which labile newly formed memory traces are progressively strengthened into long term memories and become more resistant to interference. Recent work has revealed that spontaneous hippocampal activity during rest, commonly referred to as "offline" activity, plays a critical role in the process of memory consolidation. Hippocampal reactivation occurs during sharp-wave ripples (SWRs), which are events associated with highly synchronous neural firing in the hippocampus and modulation of neural activity in distributed brain regions. Memory consolidation occurs primarily through a coordinated communication between hippocampus and neocortex. Cortical slow oscillations drive the repeated reactivation of hippocampal memory representations together with SWRs and thalamo-cortical spindles, inducing long-lasting cellular and network modifications responsible for memory stabilization.In this review, we aim to comprehensively cover the field of "reactivation and memory consolidation" research by detailing the physiological mechanisms of neuronal reactivation and firing patterns during SWRs and providing a discussion of more recent key findings. Several mechanistic explanations of neuropsychiatric diseases propose that impaired neural replay may underlie some of the symptoms of the disorders. Abnormalities in neuronal reactivation are a common phenomenon and cause pathological impairment in several diseases, such as Alzheimer's disease (AD), epilepsy and schizophrenia. However, the specific pathological changes and mechanisms of reactivation in each disease are different. Recent work has also enlightened some of the underlying pathological mechanisms of neuronal reactivation in these diseases. In this review, we further describe how SWRs, ripples and slow oscillations are affected in Alzheimer's disease, epilepsy, and schizophrenia. We then compare the differences of neuronal reactivation and discuss how different reactivation abnormalities cause pathological changes in these diseases. Aberrant neural reactivation provides insights into disease pathogenesis and may even serve as biomarkers for early disease progression and treatment response.

[Percutaneous achilles tendon lengthening through double hemisection in the treatment of achilles contracture syndrome].

OBJECTIVE: To explore the surgical approach of percutaneous double hemisection and evaluate its clinical efficacies. METHODS: From May 2006 to November 2011, a total of 59 patients were recruited. There were 36 males and 21 females with a mean age of 38.2 years (range: 8 - 62). Forty-two varus and 6 valgus feet underwent percutaneous double hemisection. The 0.5 cm coracoid incision was adopted at the medial and lateral aspects of Achilles tendon. Percutaneous double hemisection was employed according to the deformity angles of varus and valgus feet. Manipulative correction was applied slowly until 30° dorsiflexion of ankle. Short leg cast was immobilized for 5 weeks at 30° dorsiflexion of ankle. The force of Achilles tendon, motion of ankle and Hannover Achilles tendon scores were followed up. RESULTS: Fifty-two patients were followed up for a mean period of 16.5 months (range: 6 - 60). Seven patients were lost. At the end of follow-up, 48 patients with varus and valgus deformities were corrected effectively. When compared with the normal side, the force of Achilles of the operated side of 50 patients had no change while that of 2 patients decreased slightly; the motion of ankle joint increased from (2.8 ± 0.3)° preoperatively to (28.5 ± 1.4)° postoperatively (P < 0.05); the Hannover Achilles Tendon Scores rose from (68.5 ± 3.5) preoperatively to (82.6 ± 4.2) points postoperatively (P < 0.05). The outcomes were excellent (n = 44), very good (n = 5), good (n = 2) and poor (n = 1). The excellent and good rate was 94.2%. CONCLUSION: As an effective therapy for Achilles tendon contracture syndrome, percutaneous double hemisection has fewer complications and a faster recovery.

[Effects of different cyclic mechanical stretching loads on human tenocytic cytoskeleton in vitro].

OBJECTIVE: To investigate the human tenocyte cytoskeleton under different in vitro stretching conditions and analyze the relations between the changes of tenocytic cytoskeleton and different stretching loads. METHODS: Human tenocytes, cultivated for 5 -7 passages, were stretched under 4%, 8% and 12% cyclic mechanical stretching with a duration of 2, 4, 8, 12, 24 hours and a frequency of 0.5 and 1.0 Hz. Laser scanning confocal microscope was used to examine the changes of F-actin and nucleus after immunofluorescent staining at different cyclic mechanical stretching loads on human tenocyte. The uni-cell average fluorescence intensity was measured with an image analysis system by the photos of human tenocyte cytoskeleton and analyzed by the single factor analysis of variance. RESULTS: After cyclic stretching under 4% stretching with a duration of 2 hours at 0.5 Hz, the microfilament of human tenocyte had an irregular and dim alignment. F-actin was thicker and ruptured under 4% stretching with a duration of 4 hours. Under 8% stretching with a duration of 4 hours at 0.5 Hz, all actin microfilaments ruptured, but part of membrane microfilament remained intact. There was a rising trend of actin filament fracturing under 12% stretching with a duration of 2, 4, 8, 12, 24 hours at 1.0 Hz. And all actin filaments fractured at 24 hours. In the control group, the fluorescent intensity of F-actin was at the highest and the filament remained intact. Under the same stretching frequency, the fluorescent intensity of F-actin had a declining trend and significant differences existed under different stretching loads with different durations (P < 0.05). The fluorescent intensity of F-actin increased in all experimental groups, but it was lower than that of the control group with a duration of 8 hours. The expression of F-actin decreased with a longer duration and reached its lowest at 24 hours. The most obvious phenomenon of nuclear condensation and apoptotic body formation was observed under 4% stretching with a duration of 4 hours at 0.5 Hz. CONCLUSION: Different cyclic mechanical stretching may cause the in vitro breakage and depolymerization of human tenocytic F-actin. Such an effect correlates with stretching force and its duration.

[Relationship between glenoid inclination or version and supraspinatus tendon full-thickness tears].

OBJECTIVE: To investigate the relationship between glenoid inclination or version and supraspinatus tendon full-thickness tears. METHODS: Forty-two cases of unilateral supraspinatus tendon full-thickness tears were confirmed by clinical examinations and MRI scans. The bilateral glenoid inclination and version angles, measured by the volume rendering technique (VRT) and multi-planar reformation (MPR) of multi-slice computed tomography (MSCT) under 16-slice spiral CT scans, were compared by paired t test in all cases. RESULTS: The average inclination angle was (97.6 ± 4.0)° and (96.1 ± 2.9) at affected and healthy sides respectively. And the difference had statistical significance (P = 0.001); the average version angle was (-3.2 ± 5.0)° and (-3.1 ± 4.7)° at affected and healthy sides respectively. And the difference had no statistical significance (P = 0.79). CONCLUSION: The glenoid inclination angles are correlated with supraspinatus tendon full thickness tears while but the glenoid version angles are not. A larger glenoid inclination angle may be a positive predictive factor of supraspinatus tendon full-thickness tears.

[Triple arthrodesis with osteotomy for the treatment of stage IIB and stage III adult-acquired flatfoot deformity].

OBJECTIVE: To analyze the clinical outcomes of triple arthrodesis with osteotomy in the treatment of Stage IIB and Stage III adult-acquired flatfoot. METHODS: The authors reviewed 10 cases of adult-acquired flatfoot, including 3 cases of stage IIB adult-acquired flatfoot and 7 cases of stage III adult-acquired flatfoot. They were treated by triple arthrodesis with osteotomy of subtalar joint (STJ), talonavicular joint (TNJ) and calcaneocuboid joint (CCJ). The combined medial and lateral incisions were used to obtain adequate exposure for CCJ, STJ and TNJ. Then the cartilages of CCJ, STJ and TNJ were completely denuded and osteotomies to restore their proper alignments. The optimal positioning of hindfoot could be achieved and fixed by Kirschner wires. Two cannulated screws of 7.3 mm were delivered through the plantar aspect of heel to fix STJ. And then two 4.5 mm cannulated screws individually fixed TNJ and CCJ distal to proximal. Clinical evaluations were based on the AOFAS ankle-hindfoot scale and subjective assessments of pains, function, cosmesis and overall satisfaction. Radiographic evaluations included measurements of anterior-posterior talo-first metatarsal angle, lateral talocalcaneal angle, lateral talo-first metatarsal angle and an assessment of time to union for all arthrodeses. RESULTS: All patients were followed-up with a mean time of 13.2 (6 - 21) months. The average AOFAS ankle-hindfoot scale improved from 39.4 ± 4.4 preoperatively to 83.7 ± 2.6 postoperatively (P < 0.01). And the patients experienced subjective improvements in pain, function and cosmesis. Overall, all patients were satisfied. Radiographically, the rate of bone healing was 100%. The anterior-posterior talo-first metatarsal angle, lateral talocalcaneal angle and lateral talo-first metatarsal angle statistically improved. No complication, such as infection and un-union, was reported. CONCLUSION: Triple arthrodesis with osteotomy is an effective procedure for the treatment of stage IIB and III adult-acquired flatfoot deformity. It may relieve pains, correct structural deformities and obtain excellent clinical outcomes.

[Medial displacement calcaneal osteotomy with mini-incision for the treatment of acquired flexible flatfoot caused by posterior tibial tendon dysfunction].

OBJECTIVE: To investigate the clinical outcomes of medial displacement calcaneal osteotomy with mini-incision for the treatment of acquired flexible flatfoot caused by posterior tibial tendon dysfunction. METHODS: From 2005 to 2009, 10 patients (13 feet) of acquired flexible flatfoot with obvious heel valgus underwent medial displacement calcaneal osteotomy with mini-incision. The lateral skin incision of 3.0 - 4.5cm was made to explore the lateral calcaneal wall. Calcaneal osteotomy was performed from inferior and lateral to superior and medial, perpendicular to the longitudinal axis of calcaneal body. The distal segment was displaced medially for 1/3-1/2 width of calcaneal body and fixed by two parallel cannulated screws. All patients were evaluated at 6 weeks, 3 months, 6 months, 12 months and every 6 months pre- and post-operatively by clinical examinations and radiological studies. All patients were physically examined with an extended protocol of questionnaires and the AOFAS Ankle & Hindfoot Scales. The lateral view of full foot allowed an assessment of bone healing, calcaneus inclination angle (CI), talocalcaneal angle (TC) and talar first metatarsal angle (TMT). The AP view of full foot allows assessment of TC and TMT. The heel varus/valgus alignment could be evaluated on the axial radiographs of hindfoot. RESULTS: With a mean postoperative follow-up period of 20.3 months (range 7 - 55 Ms), all patients had bone union as confirmed by clinical examination and radiology. The AOFAS rating scale improved from a pre-operative mean of 50.3 to a mean of 80.2 at 6 months and a mean of 84.2 at last follow-up, without any complication of infection, nerve injure and so on. All radiographic parameters were statistically significant (P < 0.001), including CI, TC and TMT on the lateral view and TC and TMT on the AP view. The heel varus/valgus was corrected on the axial view. CONCLUSION: The medial displacement calcaneal osteotomy with mini-incision is a recommended procedure for the treatment of acquired flexible flatfoot with excellent clinical outcomes, correction of deformity and fewer complications.

Analysis of the stress distribution of the subtalar joint and fusion efficacy after double-screw insertion.

BACKGROUND: Screw fixation is a typical technique for the isolated subtalar joint. However, no consensus has been reached on how to select the most suitable insertion position and direction. This study aims to find the ideal screw insertion and then explore its influence on the clinical efficacy of subtalar fusion by analyzing the effects of different cannulated screw insertions on the stress distribution, anti-rotary strength, and anti-inversion/eversion strength of the subtalar joint. METHODS: In this study, we investigated three cannulated screw insertions for subtalar fusion: screw insertion with the most uniform stress distribution (group A), lateral-medial parallel screw insertion (group B), and traditional longitudinally parallel screw insertion (group C). The effects of these three insertions on the loading stress of the subtalar joint (including stress distribution, anti-inversion/eversion strength, and anti-rotary strength) were comparatively analyzed with the three-dimensional finite element method to screen the ideal screw insertion. Moreover, a prospective study was conducted to analyze the influence of the ideal screw insertion on subtalar fusion, including the fusion rate, fusion time, and clinical efficacy (VAS score, AOFAS score, and complications). RESULTS: Group B was worse than group A with respect to the stress distribution uniformity, but slightly better than group C, and better than both groups A and C in terms of the anti-rotary strength and anti-inversion/eversion strength. The screw insertion based on the most uniform stress distribution is not feasible in surgery. Therefore, the lateral-medial antiparallel screw insertion is the ideal insertion. From January 2012 to June 2016, 48 cases were treated by subtalar fusion with the ideal screw insertion, and then followed up for 30.6 months (12-48 months). The fusion was proved in all 48 cases with a fusion rate of 100% by X-ray or CT scan. The mean time of fusion was 12.8 weeks (12-16 weeks). The VAS score decreased from 6.00 before operation to 1.03 on the last visit (P < 0.05), and the AOFAS score increased from 57.0 to 85.6 (P < 0.05), with a good and excellent rate of 95.8%. CONCLUSIONS: The lateral-medial parallel screw insertion not only demonstrates a good stress distribution profile of the subtalar joint but also has advantages such as easy localization and operation during surgery, as well as a high fusion rate and few complications after surgery. Therefore, it is a safe, accurate, and effective fixation mode that is worthy of being popularized clinically.

Individual headless compression screws fixed with three-dimensional image processing technology improves fusion rates of isolated talonavicular arthrodesis.

BACKGROUND: Screw fixation is a typical technique for isolated talonavicular arthrodesis (TNA), however, no consensus has been reached on how to select most suitable inserted position and direction. The study aimed to present a new fixation technique and to evaluate the clinical outcome of individual headless compression screws (HCSs) applied with three-dimensional (3D) image processing technology to isolated TNA. METHODS: From 2007 to 2014, 69 patients underwent isolated TNA by using double Acutrak HCSs. The preoperative three-dimensional (3D) insertion model of double HCSs was applied by Mimics, Catia, and SolidWorks reconstruction software. One HCS oriented antegradely from the edge of dorsal navicular tail where intersected interspace between the first and the second cuneiform into the talus body along the talus axis, and the other one paralleled the first screw oriented from the dorsal-medial navicular where intersected at the medial plane of the first cuneiform. The anteroposterior and lateral X-ray examinations certified that the double HCSs were placed along the longitudinal axis of the talus. Postoperative assessment included the American Orthopaedic Foot & Ankle Society hindfoot (AOFAS), the visual analogue scale (VAS) score, satisfaction score, imaging assessments, and complications. RESULTS: At the mean 44-months follow-up, all patients exhibited good articular congruity and solid bone fusion at an average of 11.26 ± 0.85 weeks (range, 10 ~ 13 weeks) without screw loosening, shifting, or breakage. The overall fusion rates were 100%. The average AOFAS score increased from 46.62 ± 4.6 (range, 37 ~ 56) preoperatively to 74.77 ± 5.4 (range, 64-88) at the final follow-up (95% CI: -30.86 ~ -27.34; p < 0.001). The mean VAS score decreased from 7.01 ± 1.2 (range, 4 ~ 9) to 1.93 ± 1.3 (range, 0 ~ 4) (95% CI: 4.69 ~ 5.48; p < 0.001). One cases (1.45%) and three cases (4.35%) experienced wound infection and adjacent arthritis respectively. The postoperative satisfaction score including pain relief, activities of daily living, and return to recreational activities were good to excellent in 62 (89.9%) cases. CONCLUSIONS: Individual 3D reconstruction of HCSs insertion model can be designed with three-dimensional image processing technology in TNA. The technology is safe, effective, and reliable to isolated TNA method with high bone fusion rates, low incidences of complications.