Zhongli Li

Is Arthroscopic Technique Superior to Open Reduction Internal Fixation in the Treatment of Isolated Displaced Greater Tuberosity Fractures

BackgroundArthroscopic double-row suture-anchor fixation and open reduction and internal fixation (ORIF) are used to treat displaced greater tuberosity fractures, but there are few data that can help guide the surgeon in choosing between these approaches.Questions/PurposesWe therefore asked: (1) Is there a difference in surgical time between arthroscopic double-row suture anchor fixation and ORIF for isolated displaced greater tuberosity fractures? (2) Are there differences in the postoperative ROM and functional scores between arthroscopic double-row suture anchor fixation and ORIF for isolated displaced greater tuberosity fractures? (3) Are there differences in complications resulting in additional operations between the two approaches?MethodsBetween 2006 and 2012, we treated 79 patients surgically for displaced greater tuberosity fractures. Of those, 32 (41%) were considered eligible for our study based on inclusion criteria for isolated displaced greater tuberosity fractures with a displacement of at least 5 mm but less than 2 cm. During that time, we generally treated patients with displaced greater tuberosity fractures with a displacement greater than 1 cm or with a fragment size greater than 3×3 cm with open treatment, and patients with displaced greater tuberosity fractures with a displacement less than 1 cm or with a fragment size less than 3×3 cm with arthroscopic treatment. Fifty-three underwent open treatment based on those indications, and 26 underwent arthroscopic treatment, of whom 17 (32%) and 15 (58%) were available for followup at a mean of 34 months (range, 24–28 months). All patients with such fractures identified from our institutional database were treated by these two approaches and no other methods were used. Surgical time was defined as the time from initiation of the incision to the time when suture of the incision was finished, and was determined by an observer with a stopwatch. Patients were followed up in the outpatient department at 6, 12, and 24 weeks, and every 6 month thereafter. Radiographs showed optimal reduction immediately after surgery and at every followup. Radiographs were obtained to assess fracture healing. Patients were followed up for a mean of 34 months (range, 24–48 months). At the last followup, ROM, VAS score, and American Shoulder and Elbow Surgeons (ASES) score were used to evaluate clinical outcomes. All these data were retrieved from our institutional database through chart review. Complications were assessed through chart review by one observer other than the operating surgeon.ResultsPatients who underwent arthroscopic double-row suture anchor fixation had longer surgical times than did patients who underwent ORIF (mean, 95.3 minutes, SD, 10.6 minutes vs mean, 61.5 minutes, SD, 7.2 minutes; mean difference, 33.9 minutes; 95% CI, 27.4–40.3 minutes; p < 0.001). All patients achieved bone union within 3 months. Compared with patients who had ORIF, the patients who had arthroscopic double-row suture anchor fixation had greater ranges of forward flexion (mean, 152.7°, SD, 13.3° vs mean, 137.7°, SD, 19.2°; p = 0.017) and abduction (mean, 146.0°, SD, 16.4° vs mean, 132.4°, SD, 20.5°; p = 0.048), and higher ASES score (mean, 91.8 points, SD, 4.1 points vs mean, 87.4 points, SD, 5.8 points; p = 0.021); however, in general, these differences were small and of questionable clinical importance. With the numbers available, there were no differences in the proportion of patients experiencing complications resulting in reoperation; secondary subacromial impingement occurred in two patients in the ORIF group and postoperative stiffness in one from the ORIF group. The two patients experiencing secondary subacromial impingement underwent reoperation to remove the implant. The patient with postoperative stiffness underwent adhesion release while receiving anesthesia, to improve the function of the shoulder. These three patients had the only reoperations.ConclusionsWe found that in the hands of surgeons comfortable with both approaches, there were few important differences between arthroscopic double-row suture anchor fixation and ORIF for isolated displaced greater tuberosity fractures. Future, larger studies with consistent indications should be performed to compare these treatments; our data can help inform sample-size calculations for such studies.Level of EvidenceLevel III, therapeutic study.

Radial shockwave treatment promotes human mesenchymal stem cell self-renewal and enhances cartilage healing

BackgroundShockwaves and mesenchymal stem cells (MSCs) have been widely accepted as useful tools for many orthopedic applications. However, the modulatory effects of shockwaves on MSCs remain controversial. In this study, we explored the influence of radial shockwaves on human bone marrow MSCs using a floating model in vitro and evaluated the healing effects of these cells on cartilage defects in vivo using a rabbit model.MethodsMSCs were cultured in vitro, harvested, resuspended, and treated with various doses of radial shockwaves in a floating system. Cell proliferation was evaluated by growth kinetics and Cell Counting Kit-8 (CCK-8) assay. In addition, the cell cycle and apoptotic activity were analyzed by fluorescence activated cell sorting. To explore the “stemness” of MSCs, cell colony-forming tests and multidifferentiation assays were performed. We also examined the MSC subcellular structure using transmission electron microscopy and examined the healing effects of these cells on cartilage defects by pathological analyses.ResultsThe results of growth kinetics and CCK-8 assays showed that radial shockwave treatment significantly promoted MSC proliferation. Enhanced cell growth was also reflected by an increase in the numbers of cells in the S phase and a decrease in the numbers of cells arrested in the G0/G1 phase in shockwave-treated MSCs. Unexpectedly, shockwaves caused a slight increase in MSC apoptosis rates. Furthermore, radial shockwaves promoted self-replicating activity of MSCs. Transmission electron microscopy revealed that MSCs were metabolically activated by shockwave treatment. In addition, radial shockwaves favored MSC osteogenic differentiation but inhibited adipogenic activity. Most importantly, MSCs pretreated by radial shockwaves exhibited an enhanced healing effect on cartilage defects in vivo. Compared with control groups, shockwave-treated MSCs combined with bio-scaffolds significantly improved histological scores of injured rabbit knees.ConclusionsIn the present study, we found that radial shockwaves significantly promoted the proliferation and self-renewal of MSCs in vitro and safely accelerated the cartilage repair process in vivo, indicating favorable clinical outcomes.

Long-term Outcome of Multiple Small-diameter Drilling Decompression Combined with Hip Arthroscopy versus Drilling Alone for Early Avascular Necrosis of the Femoral Head

Background: Avascular necrosis of femoral head (AVNFH) typically presents in the young adults and progresses quickly without proper treatments. However, the optimum treatments for early stage of AVNFH are still controversial. This study was conducted to evaluate the therapeutic effects of multiple small-diameter drilling decompression combined with hip arthroscopy for early AVNFH compared to drilling alone. Methods: This is a nonrandomized retrospective case series study. Between April 2006 and November 2010, 60 patients (98 hips) with early stage AVNFH participated in this study. The patients underwent multiple small-diameter drilling decompression combined with hip arthroscopy in 26 cases/43 hips (Group A) or drilling decompression alone in 34 cases/55 hips (Group B). Patients were followed up at 6, 12, and 24 weeks, and every 6 months thereafter. Radiographs were taken at every follow-up, Harris scores were recorded at the last follow-up, the paired t-test was used to compare the postoperative Harris scores. Surgery effective rate of the two groups was compared using the Chi-square test. Results: All patients were followed up for an average of 57.6 months (range: 17–108 months). Pain relief and improvement of hip function were assessed in all patients at 6 months after the surgery. At the last follow-up, Group A had better outcome with mean Harris’ scores improved from 68.23 ± 11.37 to 82.07 ± 2.92 (t = −7.21, P = 0.001) than Group B with mean Harris’ scores improved from 69.46 ± 9.71 to 75.79 ± 4.13 (t = –9.47, P = 0.037) (significantly different: t = –2.54, P = 0.017). The total surgery effective rate was also significantly different between Groups A and B (86.0% vs. 74.5%; &khgr;2 = 3.69, P = 0.02). Conclusion: For early stage of AVNFH, multiple small-diameter drilling decompression combined with hip arthroscopy is more effective than drilling decompression alone.

Mechanical tests, wear simulation and wear particle analysis of carbon-based nanomultilayer coatings on Ti6Al4V alloys as hip prostheses

Carbon-based nanomultilayer coatings were deposited on medical-grade Ti6Al4V alloy using a magnetron sputtering technique under a graded bias voltage. The mechanical properties of the nanomultilayer coatings were investigated by nanoindentation, Rockwell and scratch tests as well as a ball-on-disk tribometer. The biological properties related to the immunological response of the coatings were investigated by wear simulation and wear particles analysis. Wear simulation was done according to ISO 14242, wear particles were analysed according to ISO 17853, and then compared with CoCr femoral heads. The results revealed that the carbon-based nanomultilayer coatings showed a multilayer structure, with a hardness of ∼20 GPa, an elastic modulus of ∼175 GPa, an adhesion higher than 80 N, and a low average coefficient of friction of 0.1. The average gravimetric wear rate of the polyethylene cups between the coated and CoCr groups had no statistical difference (P = 0.098). The average equivalent circle diameter of particles produced in the coated group was larger than that in CoCr (P = 0.001), but the proportion of submicron particles and globular/circular particles was not significantly different between the two groups (P > 0.05). Results showed lower Co/Cr ion contamination in the coated group. Hence, the carbon-based nanomultilayer coating on Ti6Al4V has good mechanical and tribological properties, releases fewer harmful metal ions and would not cause a more intense immunological host response than a CoCr prosthesis. The newly designed a-C nanomultilayer coatings are expected to prolong the longevity of artificial hip joints.

Subchondral bone derived mesenchymal stem cells display enhanced osteo-chondrogenic differentiation, self-renewal and proliferation potentials

Rabbit mesenchymal stem cells (MSCs) are important seed cells in regenerative medicine research, particularly in translational research. In the current study, we showed that rabbit subchondral bone is a reliable source of MSCs. First, we harvested subchondral bone (SCB) from the rabbit knee-joint and initiated the MSC culture by cultivating enzyme-treated SCB. Adherent fibroblast-like cells that outgrew from SCB fulfill the common immuno-phenotypic criteria for defining MSCs, but with low contamination of CD45+ hematopoietic cells. Interestingly, differentiated SCB-MSCs expressed osteogenic and chondrogenic markers at significantly higher levels than those in bone marrow cell suspension-derived MSCs (BMS-MSCs) (P<0.05). No differences in the expression of adipogenic markers between SCB-MSC and BMS-MSC (P>0.05) were observed. Moreover, the results of the colony forming unit-fibroblast assay and sphere formation assay demonstrated that the SCB-MSCs had increased self-renewal potential. SCB-MSCs expressed higher levels of the stemness markers Nanog, OCT4, and Sox-2 compared to in BMS-MSCs (P<0.05). Furthermore, the results of both the CCK-8-based assay and CFSE dilution assay showed that SCB-MSCs exhibited enhanced proliferative capacity. In addition, SCB-MSCs exhibited higher phosphorylation of extracellular signal-related kinase/mitogen-activated protein kinase signaling, which is closely related to MSC proliferation. In conclusion, we identified SCB-MSCs as a novel stem cell population that met the requirements of MSCs; the unique properties of SCB-MSC are important for the potential treatment of tissue damage resulting from disease and trauma.