Macroscopic and Histological Evaluations of Meniscal Allograft Transplantation Using Gamma Irradiated Meniscus: A Comparative in Vivo Animal Study

Background:

Many studies suggest that the gamma irradiation decreases allograft strength in a dose-dependent manner. However, no study has demonstrated that this decrease in strength translates into higher failure rate in meniscal allograft transplantation (MAT). The aim of this study was to investigate the effects of gamma irradiation on macroscopic and histological alterations of transplanted meniscal tissue and joint cartilage after MAT.

Methods:

Medial total meniscectomies were performed on the right knees of 60 New Zealand white rabbits. All meniscal allografts were divided into three groups (20 in each group) and then sterilized with 0 Mrad, 1.5 Mrad, or 2.5 Mrad of gamma irradiation. For each group, 5 menisci were randomly chosen for scanning electron microscopic (SEM) analysis and the remaining 15 were prepared for MAT surgeries. Forty-five right knees received MAT surgeries (0 Mrad group, 1.5 Mrad group, 2.5 Mrad group, 15 in each group), whereas the remaining 15 only received medial meniscectomy (Meni group). The left knees of the Meni group were chosen as the Sham group (n = 15). All the rabbits were sacrificed at week 24 postoperatively. Cartilage of the medial compartment of each group was evaluated macroscopically using the International Cartilage Repair Society (ICRS) score and then histologically using the Mankin score based on the Masson Trichrome staining.

Results:

The SEM analysis confirmed that the meniscal collagen fibers would be significantly damaged as the dose of gamma irradiation increased. At week 24, the overall scores of macroscopic evaluations of the transplanted meniscal tissue showed no significant differences among the three groups receiving MAT surgeries, except for 2 in the 2.5 Mrad group presented partial radial tears at midbody. The ICRS scores and the Mankin scores showed the lowest in the Sham group and the highest in the Meni group (P < 0.05). For the three groups receiving MAT surgeries, the 2.5 Mrad group showed significant higher ICRS scores and Mankin scores than both the 0 Mrad group and the 1.5 Mrad group (P < 0.05). Whereas the 1.5 Mrad group presented similar results to the 0 Mrad group concerning both the ICRS scores and the Mankin scores.

Conclusions:

The current in vivo animal study proved that although the meniscal collagen fibers were damaged after gamma irradiation, the failure rate of MAT surgeries might not significantly increase if the irradiation dose was <1.5 Mrad for New Zealand white rabbits.     

川崎病并发冠状动脉病变的早期防治

目的探讨川崎病(KD)并发冠状动脉病变患者的早期防治方法与效果。方法将我院2004年1月~2014年7月接诊的川崎病并发冠状动脉病变患者42例作为研究对象,随机均分为研究组与对照组,各自21例。其中对照组患者早期单用阿司匹林防治,而研究组患者则采取静注丙种球蛋白并予以阿司匹林治疗。观察记录两组患者心脏彩超与实验室检查结果,并对比分析。结果经心脏彩超检查治疗前后可知,研究组治疗前彩超正常患儿治疗后转为异常有1例,而对照组则出现5例,组间对比差异有统计学意义(P0.05);两组患者治疗前实验室指标无显著性差异,但治疗后研究组在实验室指标上皆明显低于对照组,更趋于正常范围,组间对比差异有统计学意义(P0.05)。结论静脉滴注丙种球蛋白用于早期防治川崎病并发冠状动脉病变患者可取得比较良好的效果,防治效果显著,同时能明显改善患者的实验室指标,值得借鉴。     

伽玛刀治疗颅内软骨肉瘤四例报道及文献回顾

目的 探讨伽玛刀放射外科治疗颅内软骨肉瘤的临床疗效. 方法 回顾性分析天津医科大学第二医院神经外科伽玛刀中心自2004年11月至2012年1月收治的4例软骨肉瘤患者诊治过程.4例患者均行手术切除并经病理证实,其中男1例,女3例;年龄26～36岁,平均31.3岁.肿瘤体积0.6～25.4 cm3,平均13.8 cm3;边缘剂量15～20 Gy,平均17.3 Gy;中心剂量30～40 Gy,平均35 Gy;靶点数4～19个,平均10个.本组随访时间5～28个月,平均14.5个月. 结果 1例左侧乳突及颈静脉孔区患者及1例鞍区患者治疗后分别随访19个月、9个月,肿瘤未见增大,生存良好;1例右侧眶颅沟通患者随访28个月后复发,后两次行手术治疗,效果不佳,于伽玛刀治疗后56个月死亡;1例左侧鞍旁患者治疗后5个月肿瘤复发,伴脑积水,随后失访.4例均未出现任何与伽玛刀治疗相关的并发症. 结论 伽玛刀治疗定位精确度高,疗效可靠且对周围组织损伤小,可作为术后残留软骨肉瘤辅助治疗方法.     

股骨转子间骨折3种内固定方法的疗效比较

目的探讨不同内固定治疗股骨转子间骨折的临床疗效。方法 97例股骨转子间骨折患者按治疗方法分为3组:动力髋螺钉固定组(A组)37例,解剖锁定钢板固定组(B组)36例,Gamma钉固定组(C组)24例。分析各种方法的疗效及优缺点。结果手术时间:A组为(102±19)min,B组为(75±15)min,C组为(71±11)min;A组与B、C组比较差异均有统计学意义(P<0.01),B组与C组比较差异无统计学意义(P>0.05)。出血量:A组为(501±134)ml,B组为(212±38)ml,C组为(198±31)ml;A组与B、C组比较差异均有统计学意义(P<0.01),B组与C组比较差异无统计学意义(P>0.05)。术中X线暴露次数:A组为(7±3)次,B组为(8±3)次,C组为(8±2)次;3组间两两比较差异无统计学意义(P>0.05)。术后髋关节功能Harris评分优良率:A组83.78%,B组88.88%,C组87.50%。结论 Gamma钉具有手术耗时少、术中X线透视时间短、创伤小、术后内固定稳定性强、并发症少、骨折愈合快、患肢功能恢复快等优点,可以作为治疗股骨转子间骨折优选内固定方法;解剖锁定钢板结合微创技术治疗股骨转子间骨折也有较大的适用范围;动力髋螺钉操作简单,适宜应用于无严重骨质疏松的A1型和A2转子间骨折。     

Gamma Knife radiosurgery in the management of brainstem metastases

Background

Metastases to the brainstem portend a poor prognosis and present a challenge in clinical management. Surgical resection is rarely a viable option.

Methods

Post-treatment MRI scans of patients with brainstem metastases treated with radiosurgery were used to determine local control and disease progression. Median survival was calculated using Kaplan–Meier analysis. Univariate and multivariate analyses were performed using log-rank test and Cox proportional hazards model, respectively.

Results

Thirty-two consecutive patients with brainstem metastasis underwent Gamma Knife radiosurgery. Median age was 50 years. Median tumor volume was 0.71 cm³ and median tumor margin dose was 13 Gy. Seventeen of 32 patients received WBRT prior to stereotactic radiosurgery. Median survival was 5.2 months. There was a statistically significant difference in survival based on RTOG recursive partition analysis (RPA) class. Median survival of patients categorized as RPA class I was 19.2 months, RPA class II was 8.4 months, and RPA class III was 1.9 months. The overall local tumor control rate was 87.5%. There were no acute complications following stereotactic radiosurgery and no evidence of radiation necrosis noted on post-treatment MRI scans.

Conclusion

Stereotactic radiosurgery is an effective treatment for brainstem metastases and should be considered especially for patients with good performance status.     

Visual demonstration of aliasing in planar nuclear medicine imaging: The importance of correct collimator selection by nuclear medicine practitioners

Aliasing artefact is an imaging distortion phenomenon experienced in a wide variety of medical imaging modalities. This case report illustrates its occurrence during planar gamma camera nuclear medicine imaging under non-clinical conditions using experimental incorrect selection of collimators. In accordance with provision of an optimal service, nuclear medicine practitioners are recommended to have sufficient technical expertise along with knowledge of gamma camera operation. The purpose, construction and interaction of collimators used during planar imaging are presented herein with specific regards to the aliasing phenomenon. Furthermore, this case report recommends the careful planning of worklists to avoid frequent collimator changes to reduce the risk of human error.