Daqi Xu

Allograft versus autograft for anterior cruciate ligament reconstruction: an up-to-date meta-analysis of prospective studies.

PurposeAlthough a large number of anterior cruciate ligament (ACL) reconstructions are performed annually, there remains a considerable amount of controversy over whether an autograft or an allograft should be used. The aim of this meta-analysis was to compare the clinical outcomes of allograft and autograft in primary ACL reconstruction.MethodsThe authors systematically searched electronic databases to identify prospective studies which compared allografts with autografts for primary ACL reconstruction. The results of the eligible studies were analysed in terms of instrumented laxity measurements, Lachman test, Pivot Shift test, objective International Knee Documentation Committee (IKDC) Scores, Lysholm Scores, Tegner Scores, and clinical failures. Study quality was assessed and relevant data were extracted independently by two reviewers. A random effect model was used to pool the data. Statistical heterogeneity between trials was evaluated by the chi-square and I-square tests.ResultsNine studies, with 410 patients in the autograft and 408 patients in the allograft group, met the inclusion criteria. Five studies compared bone-patellar tendon-bone (BPTB) grafts, and four compared soft-tissue grafts. Four studies were randomized controlled trials, and five were prospective cohort studies. The results of the meta-analysis showed that there were no significant differences between allograft and autograft on all the outcomes in terms of instrumented laxity measurements (P = 0.59), Lachman test (P = 0.41), Pivot Shift test (P = 0.88), objective IKDC Scores (P = 0.87), Lysholm Scores (P = 0.79), Tegner Scores (P = 0.06), and clinical failures (P = 0.68). These findings were still robust during the sensitivity analysis. However, a subgroup analysis of Tegner scores by involving only BPTB grafts showed a statistical difference in favour of autografts (P = 0.005).ConclusionsThere was insufficient evidence to identify which of the two types of grafts was significantly better for ACL reconstruction, though the subgroup analysis indicated that reconstruction with BPTB autograft might allow patients to return to higher levels of activity in comparison with BPTB allograft. More high-quality randomized controlled trials with specified age and activity level are highly required before drawing a reliable conclusion.

Clinical outcomes of remnant preserving augmentation in anterior cruciate ligament reconstruction: a systematic review.

PurposeThe objective of this study was to systematically review the current evidence to see whether the remnant preservation techniques could obtain better clinical outcomes than the standard anterior cruciate ligament reconstruction procedure.MethodsThe authors systematically searched online databases to identify the studies which compared the remnant preservation techniques with the standard techniques. Two reviewers independently extracted data and evaluated the methodological quality of each study. Clinical outcomes in terms of knee stability, clinical scores, vascularization, proprioception, tibial tunnel enlargement and complications were qualitatively compared.ResultsThirteen studies met the inclusion criteria for review. Compared with the standard procedure, significantly better results regarding knee stability in the remnant preserving group were reported in two of nine studies in the instrumented knee laxity, one of eight studies in the Lachman test and none of eight studies regarding the pivot shift test. Five studies assessed International Knee Documentation Committee scores but found no differences. One of two studies indicated significantly earlier revascularization according to the signal/noise quotient value of the graft on magnetic resonance imaging. One of two studies indicated significantly better proprioceptive function in terms of joint position sense using the reproduction of passive positioning test. Two of two studies showed significantly less tibial tunnel enlargement in the remnant preserving group. None of the studies showed significant increase in the risk of cyclops lesion formation and the loss of knee range of motion in the remnant augmentation group.ConclusionsThe current evidence suggests that the short-term clinical outcomes of patients with the remnant augmentation technique are comparable, if not superior, with that of patients undergoing the standard technique, although it is insufficient to justify the remnant preserving augmentation as a routine treatment for anterior cruciate ligament ruptures.Level of evidenceSystematic review, Level IV.

Combined application of low-intensity pulsed ultrasound and functional electrical stimulation accelerates bone–tendon junction healing in a rabbit model

The objective of this study was to elucidate the combined use of low‐intensity pulsed ultrasound (LIPUS) and functional electrical stimulation (FES) on patella–patellar tendon (PPT) junction healing using a partial patellectomy model in rabbits. LIPUS was delivered continuously starting day 3 postoperative until week 6. FES was applied on quadriceps muscles to induce tensile force to the repaired PPT junction 5 days per week for 6 weeks since week 7 postoperatively. Forty rabbits with partial patellectomy were randomly divided into four groups: control, LIPUS alone, FES alone, and LIPUS + FES groups. At week 12, the PPT complexes were harvested for histology, radiographs, peripheral quantitative computed tomography, and biomechanical testing. There was better remodeling of newly formed bone and fibrocartilage zone in the three treatment groups compared with the control group. LIPUS and/or FES treatments significantly increased the area and bone mineral content of new bone. The failure load and ultimate strength of PPT complex were also highly improved in the three treatment groups. More new bone formed and higher tensile properties were showed in the LIPUS + FES group compared with the LIPUS or FES alone groups. Early LIPUS treatment and later FES treatment showed the additive effects of accelerating PPT junction healing.

Enhanced Patella–Patellar Tendon Healing Using Combined Magnetic Fields in a Rabbit Model

Background: A combined magnetic field (CMF) is a composite of a dynamic sinusoidal magnetic field and a magnetostatic field. Stimuli from CMFs has proved to be an effective tool for healing problem fractures and spinal fusion procedures. Hypothesis: Combined magnetic field technology will enhance healing of bone-tendon junction repair via endochondral ossification for regeneration of the fibrocartilage zone. Study Design: Controlled laboratory study. Methods: Forty-eight mature rabbits were randomly divided into CMF-treated and placebo-treated (control) groups. A partial patellectomy model was created. The CMF-treated group was subjected to CMF stimulation from the third postoperative day for 30 minutes per day up to weeks 8 or 16. At each time point, tissue samples were harvested and evaluated biomechanically and histomorphologically. The area of newly formed bone and the thickness of fibrocartilage were measured in hematoxylin and eosin–stained sections and toluidine blue–stained sections, respectively, while the density of fibrocartilage cells and the amount of proteoglycans were calculated using safranin O–stained sections. A biomechanical analysis was carried out to ascertain tensile strength. Results: Quantitative histological measurements showed that the newly formed bone and regenerated fibrocartilage zone in the CMF-treated group increased by a respective 99.2% and 41.9% compared with the control group at week 8 and a respective 97.8% and 22.8% at week 16. In the CMF-treated group at postoperative week 16, the amount of proteoglycans was 36.9% more than that of the control group, but the density of fibrocartilage cells was just 71.4% of the control group; there were no significant differences at week 8. Mechanical test results showed that energy to failure was not significantly different between the 2 groups at week 8. Yet, at week 16, load to failure, ultimate strength, and energy to failure in the CMF-treated group (311.0 ± 59.4 N, 8.46 ± 1.41 MPa, and 0.87 ± 0.17 J, respectively) were significantly higher than those in the control group (247.1 ± 65.6 N, 6.84 ± 1.12 MPa, and 0.52 ± 0.15 J, respectively). Conclusion: Biophysical stimulation with CMFs enhances healing after bone-tendon junction injuries in a rabbit model. Clinical Relevance: These results demonstrate the feasibility of using CMFs for stimulating bone-tendon healing after repair.

The effect of low-intensity pulsed ultrasound on bone-tendon junction healing: Initiating after inflammation stage.

The purpose of this study was to explore the effect of low‐intensity pulsed ultrasound (LIPUS) treatment initiating after inflammation stage on the process of bone‐tendon junction (BTJ) healing in a rabbit model. Thirty‐six rabbits undergoing partial patellectomy were randomly divided into two groups: control and LIPUS. The period of initial inflammatory stage is 2 weeks. So LIPUS treatment was initiated at postoperative week 2 and continued until the patella‐patellar tendon (PPT) complexes were harvested at postoperative weeks 4, 8, and 16. At each time point, the PPT complexes were harvested for qRT‐PCR, histology, radiographs, synchroton radiation micro computed tomography (SR‐µCT), and biomechanical testing. The qRT‐PCR results showed that LIPUS treatment beginning at postoperative week 2 played an anti‐inflammatory role in BTJ healing. Histologically, the LIPUS group showed more advanced remodeling of the lamellar bone and marrow cavity than the control group. The area and length of the new bone in the LIPUS group were significantly greater than the control group at postoperative weeks 8 and 16. SR‐µCT demonstrated that new bone formation and remodeling in the LIPUS group were more advanced than the control group. Biomechanical test results demonstrated that the failure load, ultimate strength and energy at failure were significantly higher than those of the control group. In conclusion, LIPUS treatment beginning at postoperative week 2 was able to accelerate bone formation during the bone‐tendon junction healing process and significantly improved the healing quality of BTJ injury.

Initiation Timing of Low-Intensity Pulsed Ultrasound Stimulation for Tendon-Bone Healing in a Rabbit Model:

Background: Low-intensity pulsed ultrasound stimulation (LIPUS) has been proven to be a beneficial biophysical therapy for tendon-bone (T-B) healing. However, the optimal time to initiate LIPUS treatment has not been determined yet. LIPUS initiated at different stages of the inflammatory phase may profoundly affect T-B healing. Purpose: An established rabbit model was used to preliminarily investigate the effect of LIPUS initiation timing on T-B healing. Study Design: Controlled laboratory study. Methods: A total of 112 mature rabbits that underwent partial patellectomy were randomly assigned to 4 groups: daily mock sonication (control group) and daily ultrasonication started immediately postoperatively (immediate group), on postoperative day 7 (7-day delayed group), or on postoperative day 14 (14-day delayed group). Peripheral leukocyte counts at the inflammatory phase were used to assess postoperative inflammation. The rabbits were sacrificed at 8 or 16 weeks postoperatively for microarchitectural, histological, and mechanical evaluations of the patella–patellar tendon (PPT) junction. Results: The biomechanical properties of the PPT junction were significantly improved in the LIPUS-treated groups. Significantly higher ultimate strength and stiffness were seen in the 7-day delayed group compared with the other groups at 8 weeks postoperatively (P < .05 for all). Newly formed bone expansion from the remaining patella in the ultrasonic treatment groups was significantly increased and remodeled compared with the control group. Micro–computed tomography analysis showed that the 7-day delayed group had significantly more bone volume and bone mineral content at the interface as compared with the other groups at 8 weeks postoperatively (P < .05 for all). Histologically, the ultrasonic treatment groups exhibited a significantly better PPT junction, as shown by more formation and remodeling of the fibrocartilage layer and newly formed bone. Additionally, peripheral leukocyte counts displayed a significant increase from postoperative day 1 to day 3 in the immediate group as compared with the other groups. Furthermore, postoperative hydrarthrosis was more likely in the immediate group. Conclusion: LIPUS started at postoperative day 7 had a more prominent effect on T-B healing compared with the other treatment regimens in this study. Clinical Relevance: The findings of the study may help optimize the initiation timing of LIPUS for T-B healing.

Combined magnetic fields accelerate bone‐tendon junction injury healing through osteogenesis

The objective of this study was to explore the effect of combined magnetic fields (CMFs) on osteogenesis and the remodeling of newly formed bone at bone‐tendon (BT) junction. Forty‐eight mature rabbits in whom partial patellectomy was performed were used to establish a BT junction injury model at the patella‐patellar tendon (PPT) complex and were then allocated to CMF treatment group (CMF group) or placebo treatment group (control group). Daily CMF therapy was delivered continuously from post‐operative day 3 to weeks 4, 8, and 16. At each time point, the animals were sacrificed, and the PPT complexes were harvested for radiographic, histological, peripheral quantitative computed tomography, and micro‐computed tomography (micro‐CT) evaluation. The area, length, and bone mineral density of the newly formed bone in the CMF group were significantly greater than the control group at post‐operative weeks 8 and 16. The micro‐CT results showed that the newly formed bone in the CMF group contained more and thicker trabeculae than the control group at weeks 8 and 16. Histologically, the CMF group showed better remodeling of the BT junction. In conclusion, CMF treatment was able to accelerate osteogenesis during BT junction repair, thus facilitating the healing of BT junction injury.

Tetramethylpyrazine Facilitates Functional Recovery after Spinal Cord Injury by Inhibiting MMP2, MMP9, and Vascular Endothelial Cell Apoptosis.

BACKGROUND Spinal cord injury (SCI) is a major public health issue that leads to neurological dysfunctions and morbidities in patients. Tetramethylpyrazine (TMP) plays a neuroprotective role in SCI; however, the underlying mechanism has not been fully elucidated. OBJECTIVE In the present study, we aimed to investigate the mechanisms and therapeutic effects of TMP on SCI. METHODS A contusion SCI model was established that used a modified Allens method. In the TMP group, TMP (200 mg/kg) was injected daily for 5 days post-injury, while in the Negative Control (NC) group, an equal volume of normal saline was injected. Hindlimb motor function was evaluated using the Basso, Beattie, Bresnahan (BBB) scale. The effects of TMP on protein levels of the matrix metalloproteinases 2 (MMP2) and 9 (MMP9), Bax and cleaved caspase-3 were determined by western blotting. Apoptotic changes in vascular endothelial cells were evaluated using immunofluorescence and TUNEL staining. Alterations in 3D vessel morphology after treatment with TMP were assessed by synchrotron radiation micro-CT (SRμCT). RESULTS TMP treatment significantly improved recovery in hindlimb motor function and attenuated vascular endothelial cell apoptosis in rats with SCI. Additionally, TMP treatment markedly decreased the protein levels of MMP2 and MMP9, pro-apoptotic bax and cleaved caspase-3 while promoting angiogenesis, as evidenced by vessel visualization using SRμCT. CONCLUSION These results indicate that TMP attenuated SCI-induced neurological impairments by the down-regulation of the expression of MMP2 and MMP9 proteins, the inhibition of vascular endothelial cell apoptosis, and the promotion of angiogenesis.

Reply to comment on Hu et al. “Allograft versus autograft for anterior cruciate ligament reconstruction: an up-to-date meta-analysis of prospective studies”

1. When all factors that could influence the effect size are the same among all eligible studies, the fixed effect models should be considered. However, in our study, some factors that could influence the effect size, such as study design and patient populations, are not identical among all included studies. We therefore chose a random-effect model to account for heterogeneity in the study design and patient selection among all eligible studies.

Anatomic reconstruction of anterior talofibular ligament with tibial tuberosity-patellar tendon autograft for chronic lateral ankle instability.

Introduction: Anatomic repair of the anterior talofibular ligament (ATFL) is challenging when the local ligamentous tissue is severely attenuated. Anatomic reconstruction of the ATFL with tibial tuberosity–patellar tendon (TT-PT) autograft is a feasible choice that can avoid the complicated tendon–bone healing and restore ankle stability. Materials and methods: From 2009 to 2015, 31 chronic lateral ankle instability (CLAI) patients (31 ankles), who had a serious injury on the ATFL only, were treated with anatomic reconstruction of ATFL with TT-PT. American orthopedic foot and ankle society ankle–hindfoot score (AHS), visual analog scale for pain score (VAS), Karlsson–Peterson score, Tegner activity level, and objective examination comprehending range of motion were used to evaluate the clinical outcomes before and after operation. Radiographically, talar tilt angles and anterior drawer were assessed in pre- and postoperative ankle stress views. Results: Among the 31 ankles, 17 ankles with single-bundle ATFL and 14 ankles with double-bundle ATFL were found at operation. At a mean follow-up of 42 months (24–82 months), all patients were satisfied with the procedure. Mean AHS significantly increased from 60.5 ± 8.2 to 93.5 ± 4.8. Mean Karlsson–Peterson score significantly increased from 55.2 ± 11.0 preoperatively to 91.2 ± 6.9 at final follow-up. Average VAS significantly decreased from 5.9 ± 1.6 preoperatively to 1.4 ± 1.0 at the latest follow-up. Mean Tegner activity level was 3.7 ± 0.9 before operation, compared with 7.0 ± 0.8 after operation. On stress radiographs, mean talar tilt angle was 17.0 ± 3.4° before operation and 3.8 ± 2.1° at the latest follow-up. In addition, mean anterior tibiotalar translation was 7.5 ± 2.2 mm before operation and 1.8 ± 1.1 mm at the latest follow-up. Conclusion: Anatomic reconstruction of the ATFL using a TT-PT autograft allows bone–bone healing in talus and tendon–tendon/periosteum healing in fibula rather than requiring tendon–bone healing, which is an alternative choice for treating CLAI caused by single ATFL insufficiency.