ABSTRACT
OBJECTIVE@#To explore the effect of chitosan (CS) hydrogel loaded with tendon-derived stem cells (TDSCs; hereinafter referred to as TDSCs/CS hydrogel) on tendon-to-bone healing after rotator cuff repair in rabbits.@*METHODS@#TDSCs were isolated from the rotator cuff tissue of 3 adult New Zealand white rabbits by Henderson step-by-step enzymatic digestion method and identified by multidirectional differentiation and flow cytometry. The 3rd generation TDSCs were encapsulated in CS to construct TDSCs/CS hydrogel. The cell counting kit 8 (CCK-8) assay was used to detect the proliferation of TDSCs in the hydrogel after 1-5 days of culture in vitro, and cell compatibility of TDSCs/CS hydrogel was evaluated by using TDSCs alone as control. Another 36 adult New Zealand white rabbits were randomly divided into 3 groups ( n=12): rotator cuff repair group (control group), rotator cuff repair+CS hydrogel injection group (CS group), and rotator cuff repair+TDSCs/CS hydrogel injection group (TDSCs/CS group). After establishing the rotator cuff repair models, the corresponding hydrogel was injected into the tendon-to-bone interface in the CS group and TDSCs/CS group, and no other treatment was performed in the control group. The general condition of the animals was observed after operation. At 4 and 8 weeks, real-time quantitative PCR (qPCR) was used to detect the relative expressions of tendon forming related genes (tenomodulin, scleraxis), chondrogenesis related genes (aggrecan, sex determining region Y-related high mobility group-box gene 9), and osteogenesis related genes (alkaline phosphatase, Runt-related transcription factor 2) at the tendon-to-bone interface. At 8 weeks, HE and Masson staining were used to observe the histological changes, and the biomechanical test was used to evaluate the ultimate load and the failure site of the repaired rotator cuff to evaluate the tendon-to-bone healing and biomechanical properties.@*RESULTS@#CCK-8 assay showed that the CS hydrogel could promote the proliferation of TDSCs ( P<0.05). qPCR results showed that the expressions of tendon-to-bone interface related genes were significantly higher in the TDSCs/CS group than in the CS group and control group at 4 and 8 weeks after operation ( P<0.05). Moreover, the expressions of tendon-to-bone interface related genes at 8 weeks after operation were significantly higher than those at 4 weeks after operation in the TDSCs/CS group ( P<0.05). Histological staining showed the clear cartilage tissue and dense and orderly collagen formation at the tendon-to-bone interface in the TDSCs/CS group. The results of semi-quantitative analysis showed that compared with the control group, the number of cells, the proportion of collagen fiber orientation, and the histological score in the TDSCs/CS group increased, the vascularity decreased, showing significant differences ( P<0.05); compared with the CS group, the proportion of collagen fiber orientation and the histological score in the TDSCs/CS group significantly increased ( P<0.05), while there was no significant difference in the number of cells and vascularity ( P>0.05). All samples in biomechanical testing failed at the repair site during the testing process. The ultimate load of the TDSCs/CS group was significantly higher than that of the control group ( P<0.05), but there was no significant difference compared to the CS group ( P>0.05).@*CONCLUSION@#TDSCs/CS hydrogel can induce cartilage regeneration to promote rotator cuff tendon-to-bone healing.
Subject(s)
Rabbits , Animals , Rotator Cuff/surgery , Chitosan , Hydrogels , Rotator Cuff Injuries/surgery , Wound Healing , Tendons/surgery , Collagen , Stem Cells , Biomechanical PhenomenaABSTRACT
Objective:To investigate the early clinical effect of fascia lata autograft bridging combined with the long head of biceps tendon transposition for treatment of irreparable massive rotator cuff tear.Methods:All of 31 cases of massive irreparable rotator cuff tear treated in our hospital from March 2016 to March 2020 were analyzed retrospectively. Among them, 17 cases (10 males, 7 females) were repaired with fascia lata autograft bridging under arthroscopy (patch group), the average age was 61.47±6.63 (ranging from 51 to 72) and 14 cases (4 males, 10 females) were repaired with fascia lata autograft bridging combined with the long head of biceps tendon transposition (combined group), the average age was 62.57±6.11 (ranging from 53 to 71). The operation time, intraoperative blood loss, postoperative complications, visual analogue scale (VAS) of pain before operation, at 1 week and 12 months after operation, Constant-Murley score of shoulder joint and American Association of shoulder and elbow Surgeons (ASES) score before operation, at 6 months and 12 months after operation were compared between the two groups. The outcome of rotator cuff healing was evaluated by MRI 1 year after operation.Results:All patients were followed up for 12-27 months (mean 18.33 ±6.8 months). There was no perioperative complication, and there was no significant difference in operation time between the two groups ( P>0.05) . The VAS score in the patch group was significantly higher than the combined group 1 week after operation ( t=2.09, P=0.048) , and there was no significant difference in VAS score 12 months after operation between the two groups. Constant-Murley score and ASES score in the combined group were significantly higher than the patch group at 6 months after operation ( t=5.23, P<0.001; t=4.45, P<0.001) , and there was no significant difference in Constant score and ASES score between the two groups at 12 months after operation. Constant score and ASES score in the two groups were significantly higher than those before operation. One year after operation, the MRI of the affected shoulder showed that the incidence of autograft patch thinning (Sugaya grade III) was 52.94%, the autograft patch structure failure rate (Sugaya grade IV and V) was 17.65% in the patch group, the autograft patch thinning rate (Sugaya grade III) was 35.71%, and the structural failure rate (Sugaya grade IV and V) was 7.14% in the combined group. The difference was statistically significant (χ 2=7.12, P=0.028) . Conclusion:Fascia lata autograft patch bridging combined with long head of biceps tendon transposition technique for treatment of irreparable massive rotator cuff tear has less pain 1 week after operation and better recovery of shoulder function half a year after operation. MRI showed better patch healing 1 year after operation.