PPP1R3A inhibits osteogenesis and negatively regulates intracellular calcium levels in calcific tendinopathy.

Calcific tendinopathy (CT) is defined by the progressive accumulation of calcium crystals in tendonic regions that results in severe pain in patients. The etiology of CT is not fully elucidated. In this study, we elucidate the role of PPP1R3A in CT. A significant decrease in PPP1R3A expression was observed in CT patient tissues, which was further confirmed in tissues from a CT-induced rat model. Overexpression of PPP1R3A ex vivo reduced the expression of osteo/chondrogenic markers OCN and Sox9, improved tendon tissue architecture, and reduced intracellular Ca2+ levels. Overexpression of SERCA2 and knockdown of Piezo1 decreased expression of osteo/chondrogenic markers and intracellular calcium in PPP1R3A-knockdown tendon cells. Lastly, PPP1R3A expression was regulated at the posttranscriptional level by binding of HuR. Collectively, the present study indicates that PPP1R3A plays an important role in regulating calcium homeostasis in tendon cells via Piezo1/SERCA2, rendering it a promising target for therapeutic interventions of CT.

Supraspinatus Tendon Reconstruction Using Fascia Lata Autograft for Irreparable Posterosuperior Massive Rotator Cuff Tears.

Superior capsule reconstruction has shown good long-term clinical efficacy in treating irreparable posterosuperior massive rotator cuff tears. However, conventional superior capsule reconstruction did not treat the medial supraspinatus tendons. Therefore, dynamic function of the posterosuperior rotator cuff does not restore effectively, especially the function of active abduction and external rotation. We describe a supraspinatus tendon reconstruction technique that presents a stepwise approach to accomplish the dual goals of stable anatomic reconstruction and restoring the dynamic function of the supraspinatus tendon.

Revascularization character of autologous fascia lata graft following shoulder superior capsule reconstruction by enhanced magnetic resonance imaging.

BACKGROUND: Fascia lata has been used for arthroscopic superior capsule reconstruction (ASCR) and verified to achieve a good clinical outcome. However, it is still not known about revascularization character of the fascia lata after ASCR. This study was performed to evaluate the revascularization of autologous fascia lata grafts after ASCR by enhanced magnetic resonance imaging (MRI). METHODS: A prospective study of 19 patients with irreparable rotator cuff tears underwent ASCR with autologous fascia lata grafts from September 2019 to April 2021. Radiography examinations and clinical evaluations were performed preoperatively and postoperatively at 6 weeks and 3, 6, and 12 months. The signal-to-noise quotient (SNQ) value and enhancement index (EI) of autologous fascia lata grafts in the great tubercle insertion (GTI), midpoint of the graft (MG), and glenoid insertion (GI) were compared for radiography examination. Clinical evaluation included the American Shoulder and Elbow Surgeons (ASES) score, University of California Los Angeles (UCLA) shoulder score, and Visual Analog Scale (VAS) score. RESULTS: The SNQ values in T1WI enhancement at GI and GTI were significantly higher than those at the plain MRI scan at all postoperative observation timepoints; however, the SNQ values in T1WI enhancement at MG did not show a significant difference until 3 months postoperation. EI values at GTI and GI were significantly higher than those at MG at 6 weeks and 3 months postoperation, while there was no significant difference in the EI value between GTI and GI. At 6 months postoperation, the EI value at GI was significantly higher than those at MG. At 12 months postoperation, the EI value at GI was significantly higher than those at MG and GTI; however, there was no significant difference between GTI and MG. The EI values at GTI and MG peaked at 3 months and 6 months postoperation, respectively, and then plateaued at 12 months postoperation. However, there was no significant difference in the EI value among the different postoperative timepoints at GI. The EI value did not correlate with the VAS and ASES, UCLA scores at any time point or any postoperative observation location. CONCLUSION: Revascularization of the fascia lata was dependent on the location of the fascia lata and plateaus at 12 months postoperation. The EI value did not correlate with the VAS and ASES, UCLA scores during12 months postoperation.

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.

Tibiotalocalcaneal arthrodesis with headless compression screws.

BACKGROUND: Tibiotalocalcaneal arthrodesis with headless compression screws has not been previously reported. We hypothesized that these screws could be suitable for tibiotalocalcaneal arthrodesis because of their special design. This study aimed to evaluate the clinical outcomes of patients undergoing tibiotalocalcaneal arthrodesis with headless compression screws for the treatment of severe arthropathy of the ankle and subtalar joint. METHODS: From 2010 to 2015, 23 patients with severe ankle and subtalar arthropathy underwent tibiotalocalcaneal arthrodesis. All surgeries were completed by a senior surgeon in the same hospital. These patients were 18~76 years (mean 54.6 years) old; the duration of their disease was 9~38 months (mean 13.2 months). The study population included 12 males and 11 females; 12 patients underwent surgery on the left and 11 on the right. Indications for surgery included avascular necrosis of the talus (n = 14), severe posttraumatic arthritis (n = 4), osteoarthritis (n = 2), terminal tuberculous arthritis (n = 1), rheumatoid arthritis (n = 1) and Charcot neuroarthropathy (n = 1). A lateral oblique incision was performed to expose the subtalar joint, and an anteromedial longitudinal incision was used to expose the ankle joint. After the articular surfaces were removed, the tibia, talus and calcaneus were carefully aligned and fixed with two headless compression screws. Patients were followed up at 6 weeks and 3, 6 and 9 months after surgery; they were evaluated by Roles and Maudsley patient satisfaction scores, the American Orthopaedic Foot & Ankle Society (AOFAS) Ankle-Hindfoot Score, visual analogue scale (VAS) score and radiographic evaluation. RESULTS: Seventeen patients were studied, with a mean follow-up time of 6.5 months (range 5-24). The mean Roles and Maudsley patient satisfaction score was 1.41 at the last follow-up; most of the patients were satisfied with the surgery results. The mean preoperative AOFAS Ankle-Hindfoot Score was 29.6 (range 18-37), while the mean last follow-up AOFAS Ankle-Hindfoot Score was 68.5 (range 61-80). The VAS score for preoperative functional pain was 6.95 (range 3-10) compared to 1.56 (range 0-3) postoperatively (P < 0.001). The mean surgical duration was 57 (range 42-125) min. The mean time to union was 3.8 months (range 3-12 months); fusion of the ankle and subtalar joint was successful in all patients. One patient experienced delayed wound healing. CONCLUSIONS: Tibiotalocalcaneal arthrodesis with headless compression screws for the treatment of severe arthropathy of the ankle and subtalar joint is an effective treatment that is minimally invasive and is associated with a short operation time, high fusion rate, low incidence of complications and good postoperative recovery.

Differential efficacy of subtalar fusion with three operative approaches.

BACKGROUND: There are many existing operative approaches for subtalar fusion; however, no optional strategy of operative approach has been developed yet. This study aimed to analyze the differential clinical efficacy of subtalar fusion with three operative approaches. METHODS: The clinical data of 102 patients from April 2008 to April 2012 were analyzed prospectively. These patients were divided into three groups with the random number table: group A, group B, and group C. The following parameters were compared among three groups: effective exposure area and exposure time of subtalar joint, intraoperative bleeding volume, postoperative complications, fusion time, fusion rate, AOFAS score and VAS score before and after operation. RESULTS: In the exposure area score, there was no statistically significant difference between group A and group C (P > 0.05) ,but with a statistically significant difference between group A/C and group B (P < 0.05). In exposure time and intraoperative bleeding volume, there was no statistically significant difference between group A and group B (P > 0.05) but with a statistically significant difference between group A/B and group C (P < 0.05). In three groups, there was a statistically significant difference in both AOFAS score and VAS score before operation and at 6 months/12 months/last visit after operation (P < 0.05). The incidence of complications in the three groups was 8.8%, 12.5% and 19.4%. No statistically significant differences in fusion rate and fusion time were observed among the three groups (P > 0.05). CONCLUSION: Three operative approaches have different indications, All the three operative approaches do not influence the fusion rate and fusion time of subtalar joint. The lateral tarsal sinus approach is inferior to the posterior-lateral L approach and the approach from the inferior tip of fibula to the basilar part of the fourth metatarsal bone in the exposure area, while the lateral tarsal sinus approach and the approach from the inferior tip of fibula to the basilar part of the fourth metatarsal bone are superior to the posterior-lateral L approach in the exposure time, intraoperative bleeding volume, and incidence of complications.

[Clinical efficacy of subtalar joint arthrodesis with percutaneous opposite parallel cannulated screws].

OBJECTIVE: To explore the clinical efficacy of subtalar joint arthrodesis with percutaneous opposite parallel cannulated screws for severe subtalar joint arthritis. METHODS: A total of 88 patients with 90 feet underwent subtalar joint fusion under four different incisions from April 2008 to April 2012. There were 56 males and 32 females with a mean age of 43.7 (15-74) years. All of them were evaluated by radiography or computed tomography (CT) scan and assessed by the rating scores of visual analog scale (VAS) and American Orthopedic Foot and Ankle Society (AOFAS). RESULTS: Among them, 68 cases were followed up for an average of 18.5 (6-48) months. Fusion was confirmed on radiography or CT in 67 cases with a fusion rate of 98.5%. The mean duration of fusion was 13.8 (6-28) weeks, the mean VAS score decreased from 6.00 to 1.03 points (P < 0.05) and the mean AOFAS score improved from 57.0 to 80.6 points (P < 0.05) with a good-and-excellent rate of 80.8%. CONCLUSION: Subtalar joint arthrodesis with percutaneous opposite parallel cannulated screws is recommend for severe subtalar joint arthritis. Such a procedure has a high fusion rate, excellent clinical outcomes and fewer complications.

[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.

[Arthroscopic Bankart lesion repair by double-row vertical mattress suture with anchors for anteroinferior glenohumeral instability].

OBJECTIVES: To introduce a new arthroscopic Bankart repair by vertical mattress suture with anchors, and to evaluate its clinical effectiveness. METHODS: A new arthroscopic Bankart repair by vertical mattress suture with anchors was performed, including to insert only 2 anchors at 3 o'clock and 5 o'clock position and make vertical mattress suture of labrum-ligament complex at 2, 4 and 6 o'clock of labrum, and to shift up the anterior-inferior capsule. Nine cases of anterior glenohumeral instability without severe glenoid bone defect were followed-up for an average period of 14 months (range from 6 to 26 months). The average surgery age was 28 years (range from 21 to 46 years). RESULTS: The average surgery time was 51 min (40 - 75 min). Clinical scores as evaluated by the modified Rowe score advanced from 40 +/- 16 points to 92 +/- 19 points (75 - 94). There was no any recurrence and complication. External rotation was reduced by 5 degrees at 0 degrees adduction and by 3 degrees at 90 degrees of abduction. CONCLUSIONS: The arthroscopic Bankart repair by vertical mattress suture with anchors for anteroinferior glenohumeral instability is favorable as an easy, short-time surgery with excellent clinical results in short-term follow-up.