Porous Nanocomposite Comprising Ultralong Hydroxyapatite Nanowires Decorated with Zinc-Containing Nanoparticles and Chitosan: Synthesis and Application in Bone Defect Repair.

Hydroxyapatite nanowires exhibit a great potential in biomedical applications owing to their high specific surface area, high flexibility, excellent mechanical properties, and similarity to mineralized collagen fibrils of natural bone. In this work, zinc-containing nanoparticle-decorated ultralong hydroxyapatite nanowires (Zn-UHANWs) with a hierarchical nanostructure have been synthesized by a one-step solvothermal method. The highly flexible Zn-UHANWs exhibit a hierarchical rough surface and enhanced specific surface area as compared with ultralong hydroxyapatite nanowires (UHANWs). To evaluate the potential application of Zn-UHANWs in bone regeneration, the biomimetic Zn-UHANWs/chitosan (CS) (Zn-UHANWs/CS) composite porous scaffold with 80 wt % Zn-UHANWs was prepared by incorporating Zn-UHANWs into the chitosan matrix by the freeze-drying process. The as-prepared Zn-UHANWs/CS composite porous scaffold exhibits enhanced mechanical properties, highly porous structure, and excellent water retention capacity. In addition, the Zn-UHANWs/CS porous scaffold has a good biodegradability with the sustainable release of Zn, Ca, and P elements in aqueous solution. More importantly, the Zn-UHANWs/CS porous scaffold can promote the osteogenic differentiation of rat bone marrow derived mesenchymal stem cells and facilitate in vivo bone regeneration as compared with the pure CS porous scaffold or UHANWs/CS porous scaffold. Thus, both the Zn-UHANWs and Zn-UHANWs/CS porous scaffold developed in this work are promising for application in bone defect repair.

Hydroxyapatite Nanowire@Magnesium Silicate Core-Shell Hierarchical Nanocomposite: Synthesis and Application in Bone Regeneration.

Multifunctional biomaterials that simultaneously combine high biocompatibility, biodegradability, and bioactivity are promising for applications in various biomedical fields such as bone defect repair and drug delivery. Herein, the synthesis of hydroxyapatite nanowire@magnesium silicate nanosheets (HANW@MS) core-shell porous hierarchical nanocomposites (nanobrushes) is reported. The morphology of the magnesium silicate (MS) shell can be controlled by simply varying the solvothermal temperature and the amount of Mg2+ ions. Compared with hydroxyapatite nanowires (HANWs), the HANW@MS core-shell porous hierarchical nanobrushes exhibit remarkably increased specific surface area and pore volume, endowing the HANW@MS core-shell porous hierarchical nanobrushes with high-performance drug loading and sustained release. Moreover, the porous scaffold of HANW@MS/chitosan (HANW@MS/CS) is prepared by incorporating the HANW@MS core-shell porous hierarchical nanobrushes into the chitosan (CS) matrix. The HANW@MS/CS porous scaffold not only promotes the attachment and growth of rat bone marrow derived mesenchymal stem cells (rBMSCs), but also induces the expression of osteogenic differentiation related genes and the vascular endothelial growth factor (VEGF) gene of rBMSCs. Furthermore, the HANW@MS/CS porous scaffold can obviously stimulate in vivo bone regeneration, owing to its high bioactive performance on the osteogenic differentiation of rBMSCs and in vivo angiogenesis. Since Ca, Mg, Si, and P elements are essential in human bone tissue, HANW@MS core-shell porous hierarchical nanobrushes with multifunctional properties are expected to be promising for various biomedical applications such as bone defect repair and drug delivery.

Enhanced osteogenesis and angiogenesis by mesoporous hydroxyapatite microspheres-derived simvastatin sustained release system for superior bone regeneration.

Biomaterials with both excellent osteogenic and angiogenic activities are desirable to repair massive bone defects. In this study, simvastatin with both osteogenic and angiogenic activities was incorporated into the mesoporous hydroxyapatite microspheres (MHMs) synthesized through a microwave-assisted hydrothermal method using fructose 1,6-bisphosphate trisodium salt (FBP) as an organic phosphorous source. The effects of the simvastatin-loaded MHMs (S-MHMs) on the osteogenic differentiation of rat bone marrow mesenchymal stem cells (rBMSCs) and angiogenesis in EA.hy926 cells were investigated. The results showed that the S-MHMs not only enhanced the expression of osteogenic markers in rBMSCs but also promoted the migration and tube formation of EA.hy926 cells. Furthermore, the S-MHMs were incorporated into collagen matrix to construct a novel S-MHMs/collagen composite scaffold. With the aid of MHMs, the water-insoluble simvastatin was homogenously incorporated into the hydrophilic collagen matrix and presented a sustained release profile. In vivo experiments showed that the S-MHMs/collagen scaffolds enhanced the bone regeneration and neovascularization simultaneously. These results demonstrated that the water-insoluble simvastatin could be incorporated into the MHMs and maintained its biological activities, more importantly, the S-MHMs/collagen scaffolds fabricated in this study are of immense potential in bone defect repair by enhancing osteogenesis and angiogenesis simultaneously.

Prevalence of bilateral Discoid Lateral Menisci (DLM) in patients operated for symptomatic DLM with a follow-up study on their asymptomatic contralateral knees: a Magnetic Resonance Imaging (MRI) assessment.

BACKGROUND: The purpose was to investigate prevalence of bilateral discoid lateral menisci (DLM) in Han Chinese patients who received surgery for symptomatic DLM, as well as a follow-up study of their asymptomatic contralateral knees using magnetic resonance imaging (MRI). METHODS: A total of 110 patients [50 males and 60 females; average age: 21.95 ± 12.77 years (range: 6 to 67 years)] admitted to our hospital with symptomatic DLM were treated with arthroscopic surgery. The contralateral asymptomatic knees were evaluated for DLM by MRI. Postoperative clinical evaluation was performed using the Lysholm knee scoring scale and International Knee Documentation Committee subjective knee evaluation. RESULTS: Eighty (72.73%) of 110 symptomatic DLM patients had bilateral DLM, of which 68 (85%) were of homotype (same type). Fourteen of 80 bilateral DLM patients were symptomatic and received operations in both knees. Twelve of remaining 66 bilateral DLM patients with asymptomatic one knee underwent a second arthroscopic surgery as their asymptomatic knees became symptomatic over the five-year interim. Of these 12 cases, seven exhibited no shift and five showed posterocentral meniscal shift. Furthermore, at least two cases showed progression from asymptomatic grade II to symptomatic grade III over the interim. All patients showed significant improvement after surgery. CONCLUSIONS: The bilateral DLM rate of Han Chinese patients with symptomatic DLM was relatively high at 72.7 %, and 85 % of those were of homotype.

Arthroscopic tenodesis through positioning portals to treat proximal lesions of the biceps tendon.

Arthroscopic biceps tenodesis is a good choice for treating proximal lesions of the biceps tendon. However, there are few descriptions of the surgical approach. We introduce a technique for proximal biceps tenodesis using positioning portals and placing suture anchors. Our patients had a minimum of 12 months of follow-up. Between January 2010 and June 2012, a total of 49 patients (21 men, 28 women) underwent arthroscopic biceps tenodesis. The pathology was mainly associated with proximal lesions of the biceps tendon, with the diagnosis confirmed in all patients. Patients were evaluated preoperatively and then up to and including the final follow-up. Their pain and conditions were assessed using the Constant, American Shoulder and Elbow Surgeons (ASES), and University of California at Los Angeles (UCLA) scores for pain; range of active forward flexion; and active range of motion. All data were analyzed statistically. All patients were operated on successfully. They achieved good healing during the follow-up (mean 14 months; range 12-34 months). Before surgery the ASES, Constant, and UCLA scores were 17.0, 39.4, and 15.4, respectively. After surgery they were 33.6, 89.1, and 31.2, respectively. The scores had significantly improved: ASES scores from 17.0 to 33.6 (P < 0.05); Constant scores from 39.4 to 89.1 (P < 0.05); UCLA scores from 15.4 to 31.2 (P < 0.05). Arthroscopic tenodesis through positioning portals to treat proximal lesions of the biceps tendon produces satisfactory clinical outcomes. This technique is convenient and safe.

Arthroscopic reduction and fixation for isolated greater tuberosity fractures.

BACKGROUND: Traditionally, displaced greater tuberosity fractures are treated with open reduction and internal fixation. Arthroscopic treatment and outcome of greater tuberosity fractures is far from comprehensive. The objective of the current study was to assess the surgical procedure and outcome of an arthroscopic method in the treatment of isolated greater tuberosity fractures. METHODS: From January 2006 to December 2009, 23 patients with isolated greater tuberosity fractures were treated with an arthroscopic procedure using three cannulated screws combined with washers. During follow-up, radiographs and the constant shoulder score (CSS) were used to evaluate the outcome. RESULTS: Three cannulated screws with washers were used to fix the fractured fragment of the greater tuberosity under an arthroscope. All incisions healed at primary intention without infection. The mean duration of follow-up was 20 months (range 18 - 36 months). Fracture fixation was excellent, and fractures healed 2 - 6 months (mean 3.8 months) after surgery. At final follow-up, the CSS was 92 (range 86 - 100). CONCLUSIONS: The described arthroscopic procedure provides anatomical reduction and firm fixation for isolated greater tuberosity fractures. It is a successful and minimally invasive procedure with satisfying therapeutic effects as well as excellent functional recovery.

[Arthroscopic treatment of acute greater tuberosity fractures of the humerus].

OBJECTIVE: To study the outcome in the arthroscopic treatment of acute greater tuberosity fractures. METHODS: Twelve cases with acute great tuberosity fractures received reduction with arthroscopic treatment from August 2006 to December 2007. There were 7 males and 5 females. Eight cases were on left side and 4 on right side. The patients were operated at a mean age of 38 years old (range: 2745). The fractured fragments in displacements were greater than 5 mm. X-ray film and Constant score were used to evaluate the post-operative outcome. RESULTS: Three hollowed threaded screws with a washer were used to fix the big fractured fragments. The post-operative follow-up was a mean of 18 months (range: 14-33). The fracture fixations were excellent and bone union occurred. The patients received a mean Constant score of 92 (86-100) at the last follow-up. CONCLUSION: Arthroscopic treatment of acute greater tuberosity fractures is quite efficacious.

Single-bundle posterior cruciate ligament reconstruction with remnant preservation: lateral versus medial-sided augmentation technique.

OBJECTIVE: To compare the results of lateral versus medial-sided augmentation techniques in single-bundle posterior cruciate ligament (PCL) reconstruction with remnant preservation. METHODS: Forty-two cases of isolated chronic PCL ruptures were reconstructed in a single-bundle manner with remnant preservation. The patients were randomly separated into two groups: in the medial-sided augmentation (MSA) group the graft passed through the medial side of the remnant and in the lateral-sided augmentation (LSA) group it passed through the lateral side. RESULTS: Nineteen patients in the MSA group and 17 in the LSA group were followed up for a minimum of 2 years. At the final follow-up, the average side-to-side differences in posterior laxity were 1.6 ± 1.2 mm and 1.5 ± 1.3 mm respectively in the MSA and LSA groups. According to the International Knee Documentation Committee (IKDC) scale, patient numbers graded as normal, nearly normal and abnormal were 14 (73.7%), 4 (21.1%), and 1 (5.3%) in the MSA group, and 13 (76.5%), 3 (17.6%), and 1 (5.9%) in the LSA group. The IKDC subjective scores were 93.1 ± 3.8 and 92.6 ± 4.1, the Lysholm scores were 95.0 ± 4.6 and 93.7 ± 4.2, and the Tegner scores were 5.4 ± 0.9 and 5.6 ± 0.7 respectively in the MSA and LSA groups. Statistical analysis showed no significant differences between the MSA and the LSA group regarding all subjective and objective results. CONCLUSION: In single-bundle PCL reconstruction with remnant preservation, similar subjective and objective results can be obtained with MSA and LSA techniques.

A new treatment strategy for severe arthrofibrosis of the knee. Surgical technique.

BACKGROUND: To reduce the morbidity of traditional quadricepsplasty for the treatment of severe arthrofibrosis of the knee, we instituted a treatment regimen consisting of an initial extra-articular mini-invasive quadricepsplasty and subsequent intra-articular arthroscopic lysis of adhesions during the same anesthesia session. The purpose of the present study was to determine the results of this technique. METHODS: From 1998 to 2001, twenty-two patients with severely arthrofibrotic knees were managed with this operative technique. The mean age of the patients at the time of the operation was thirty-seven years. After a mean duration of follow-up of forty-four months (minimum, twenty-four months), all patients were evaluated according to the criteria of Judet and The Hospital for Special Surgery knee-rating system. RESULTS: The average maximum degree of flexion increased from 27 degrees preoperatively to 115 degrees at the time of the most recent follow-up (p < 0.001). According to the criteria of Judet, the result was excellent for sixteen knees, good for five, and fair for one. The average Hospital for Special Surgery knee score improved from 74 points preoperatively to 94 points at the time of the most recent follow-up (p < 0.001). A superficial wound infection occurred in one patient. Only one patient had a persistent 15 degrees extension lag. CONCLUSIONS: This mini-invasive operation for the severely arthrofibrotic knee can be used to increase the range of motion and enhance functional outcome.

A new treatment strategy for severe arthrofibrosis of the knee. A review of twenty-two cases.

BACKGROUND: To reduce the morbidity of traditional quadricepsplasty for the treatment of severe arthrofibrosis of the knee, we instituted a treatment regimen consisting of an initial extra-articular mini-invasive quadricepsplasty and subsequent intra-articular arthroscopic lysis of adhesions during the same anesthesia session. The purpose of the present study was to determine the results of this technique. METHODS: From 1998 to 2001, twenty-two patients with severely arthrofibrotic knees were managed with this operative technique. The mean age of the patients at the time of the operation was thirty-seven years. After a mean duration of follow-up of forty-four months (minimum, twenty-four months), all patients were evaluated according to the criteria of Judet and The Hospital for Special Surgery knee-rating system. RESULTS: The average maximum degree of flexion increased from 27 degrees preoperatively to 115 degrees at the time of the most recent follow-up (p < 0.001). According to the criteria of Judet, the result was excellent for sixteen knees, good for five, and fair for one. The average Hospital for Special Surgery knee score improved from 74 points preoperatively to 94 points at the time of the most recent follow-up (p < 0.001). A superficial wound infection occurred in one patient. Only one patient had a persistent 15 degrees extension lag. CONCLUSIONS: This mini-invasive operation for the severely arthrofibrotic knee can be used to increase the range of motion and enhance functional outcome.

[Arthroscopic treatment of tibial eminence fracture with figure-of-eight suture fixation technique].

OBJECTIVE: To introduce the arthroscopic technique of figure-of-eight suture fixation for tibial eminence fracture, and to report its clinical results. METHODS: From January 1998 to June 2001, 21 cases of tibial eminence fracture were treated arthroscopically with figure-of-eight suture fixation technique. Active rehabilitation began one week after operation. The patients were followed up 6-24 months. The reduction and union of fracture, knee laxity, range of motion, and total knee function were evaluated. RESULTS: All fracture healed without displacement six weeks after operation. Three months postoperatively, no knee laxity or instability was detected in all patients; full range of motion of the affected knee returned in all patients when compared with the normal side. Six months postoperatively, the Lysholm knee score was 93.4 +/- 2.7. CONCLUSION: Arthroscopic treatment of tibial eminence fracture with figure-of-eight suture fixation technique is reliable for fracture reduction, fixation and early mobilization. Arthroscopy is conducive to diagnoses and treatment of associated knee arthropathy, reduces the morbidity associated with arthrotomy, and restores knee function to the greatest extent when combined with figure-of-eight suture fixation techniques.