Low-frequency electrical stimulation alleviates immobilization-evoked disuse muscle atrophy by repressing autophagy in skeletal muscle of rabbits.

BACKGROUND: The study aimed to investigate the effect of low-frequency electrical stimulation (LFES) on disuse muscle atrophy and its mechanism in a rabbit model of knee extension contracture. METHODS: This study involved two experiments. In the time-point experiment, 24 rabbits were randomly divided into 4 groups: Control 1 (Ctrl1 group), immobilization for 2 weeks (I-2 group), immobilization for 4 weeks (I-4 group), and immobilization for 6 weeks (I-6 group). In the intervention experiment, 24 rabbits were randomly divided into 4 groups: Control 2 (Ctrl2 group), electrical stimulation (ESG group), natural recovery (NRG group), and electrical stimulation treatment (ESTG group). All intervention effects were assessed by evaluating the knee joint range of motion (ROM), cross-sectional area (CSA) of the rectus femoris muscle, and expression of autophagy-related proteins. RESULTS: The time-point experiment showed that immobilization reduced the knee ROM, reduced the rectus femoris muscle CSA, and activated autophagy in skeletal muscle. The levels of five autophagy-related proteins [mammalian target of rapamycin (mTOR), phosphorylated mTOR (p-mTOR), autophagy-related protein 7 (Atg7), p62, and microtubule-associated protein light chain 3B-II (LC3B-II)] were significantly elevated in the skeletal muscle of the I-4 group. The intervention experiment further showed that LFES significantly improved the immobilization-induced reductions in ROM and CSA. Additionally, LFES resulted in a significant decrease in the protein expression of mTOR, p-mTOR, Atg7, p62, and LC3B-II in the rectus femoris muscle. CONCLUSIONS: LFES alleviates immobilization-evoked disuse muscle atrophy possibly by inhibiting autophagy in the skeletal muscle of rabbits.

Comparing the early efficacies of autologous bone grafting and interbody fusion cages for treating degenerative lumbar instability in patients of different ages.

PURPOSE: The aim of this study was to compare the early efficacies of interbody fusion using autologous bone graft or an interbody fusion cage in a modified transforaminal lumbar interbody fusion (TLIF) in patients of different ages with degenerative lumbar instability. METHODS: Data from 33 patients with double-segment degenerative lumbar instability treated with a modified TLIF combined with a posterior fixation system from December 2008 to June 2014 were retrospectively analyzed. The two segments separately received an interbody bone graft fusion and an interbody fusion cage. Patients were divided by age into group A (middle-aged and elderly group, age ≥ 55 years, n = 13) and group B (young adult group, age < 55 years, n = 20). The clinical efficacy of the modified TLIF combined with a posterior fixation system was assessed using the Japanese Orthopaedic Association (JOA), Oswestry Disability Index (ODI), and Visual Analogue Scale (VAS) scores obtained before and after surgery, and at final follow-up. We measured the mean intervertebral space height, intervertebral foramen height, lumbar lordosis angle, and inter-technique differences in the mean intervertebral space height and intervertebral foramen height. Interbody fusion was evaluated using the Suk standard. RESULTS: Patients in group A followed-up for 19.15 ± 8.01 months. Patients in group B followed-up for 14.80 ± 5.47 months. The post-operative JOA, ODI, VAS, and lumbar lordosis angle were improved significantly. Moreover, the early clinical follow-up effect was good. In group A, significant differences in the intervertebral foramen height post-surgery and at final follow-up, and the mean intervertebral space height at final follow-up were noted. The intervertebral foramen and space heights were increased in the interbody cage group. In group B, a significant difference in the intervertebral foramen height at final follow-up was noted. The mean intervertebral space height post-surgery and at final follow-up was significantly increased between the two fusion methods. Bony fusion was achieved in all cases. The fusion time of autologous bone graft and interbody fusion cage was 5.46 ± 1.20 months and 6.77 ± 1.01 months respectively in group A, and 5.50 ± 1.28 months and 6.35 ± 1.76 months respectively in group B, the difference in fusion time between techniques was significant. CONCLUSION: At different ages, the interbody fusion cages can better preserve the intervertebral space and the intervertebral foramen height. However, autologous bone graft can rapidly achieve a bony fusion. Interbody fusion cages are therefore ideal for young adults, while autologous bone grafting is ideal for middle-aged and elderly patients who receive a modified TLIF.

The Learning Curve of Unilateral Biportal Endoscopic (UBE) Spinal Surgery by CUSUM Analysis.

Objective: To assess the learning curve of the unilateral biportal endoscopic (UBE) technique for the treatment of single-level lumbar disc herniation by cumulative summation (CUSUM) method analysis. Methods: A retrospective analysis was conducted to assess 97 patients' general condition, operation time, complications, and curative effect of single segmental UBE surgery performed by a spinal surgeon in his early stage of this technique. The learning curve of operation time was studied using a CUSUM method, and the cut-off point of the learning curve was obtained. Results: The operation time was 30 - 241(97.9 ± 34.7) min. The visual analog scale score of lower limb pain decreased from 5.75 ± 0.81 before the operation to 0.39 ± 0.28 at the last follow-up (P < 0.05). The Oswestry disability index score decreased from 66.48 ± 4.43 before the operation to 14.57 ± 3.99 at the last follow-up (P < 0.05). The CUSUM assessment of operation time revealed the learning curve was the highest in 24 cases. In the learning stage (1-24 cases), the operation time was 120.3 ± 43.8 min. In the skilled stage (25-97 cases), the operation time was 90.5 ± 27.8 min. Conclusions: About 24 cases of single segmental UBE operation are needed to master the UBE technique.

Rabbit Model of Extending Knee Joint Contracture: Progression of Joint Motion Restriction and Subsequent Joint Capsule Changes after Immobilization.

This study aimed to develop a rabbit model of knee contracture in extension and investigate the natural history of motion loss and time-dependent changes in the joint capsule after immobilization. We immobilized the unilateral knee joints of 32 rabbits by maintaining the knee joint in a plaster cast at full extension. Eight rabbits were euthanized at 2, 4, 6, and 8 weeks after casting, respectively, and the lower extremities were disarticulated at the hip joint. Eight control group rabbits that did not undergo immobilization were also examined. We assessed the progression of joint contracture by measuring the joint range of motion, evaluating the histologic alteration of the capsule, and assessing the mRNA levels of transforming growth factor ß1 (TGF-ß1) in the anterior and posterior joint capsules. After 2 weeks of joint immobilization, the knee joint range of motion was limited, the synovial membrane of the suprapatellar and posterior joint capsules was thickened, the collagen deposition was increased, and the mRNA levels of TGF-ß1 were elevated in the anterior and posterior joint capsules. These changes progressed rapidly until 6 weeks of immobilization and may advance slowly after 6 weeks. Joint contracture developed at the early stage of immobilization and progressed over time. The changes in the anterior and posterior joint capsules after joint immobilization may contribute to the limitation in flexion. The elevated mRNA expression of TGF-ß1 may be related to joint capsule fibrosis and may be one of the causes of joint contracture.

Effect of Stretching Combined With Ultrashort Wave Diathermy on Joint Function and Its Possible Mechanism in a Rabbit Knee Contracture Model.

OBJECTIVE: The aim of this study was to investigate the therapeutic effect of stretching combined with ultrashort wave on joint contracture and explore its possible mechanism. DESIGN: Thirty-two rabbits underwent unilateral immobilization of a knee joint at full extension to cause joint contracture. At 6 wks after immobilization, the rabbits were randomly divided into the following four groups: natural recovery group, stretching treatment group, ultrashort wave treatment group, and combined treatment group. For comparison, eight control group animals of corresponding age were also examined. The effect of stretching and ultrashort wave treatment on joint contracture was assessed by measuring the joint range of motion, evaluating the collagen deposition of joint capsule and assessing the mRNA and protein levels for transforming growth factor ß1 in the joint capsule. RESULTS: The combined treatment group led to the best recovery of joint function. The combined treatment with stretching and ultrashort wave was more effective than stretching or ultrashort wave treatment alone against the synovial thickening of suprapatellar joint capsule, the collagen deposition of anterior joint capsule, and the elevated expression of transforming growth factor ß1 in the joint capsule. CONCLUSIONS: Stretching combined with ultrashort wave treatment was effective in improving joint range of motion, reducing the biomechanical, histological, and molecular manifestations of joint capsule fibrosis in a rabbit model of extending joint contracture.