Long-term effect of intrathecal baclofen treatment on bone health and body composition after spinal cord injury: A case matched report

BACKGROUND Severe spasticity may negatively impact functionality and quality of life after spinal cord injury(SCI). Intrathecal baclofen treatment(IBT) is effectively used to manage severe spasticity and reduce comorbidities. However, long-term IBT may have a negative effect on bone mineral content(BMC), bone mineral density(BMD) and body composition(such as percentage fat mass and lean body mass). We demonstrated the negative effects of long-term IBT use in a single case compared with two non-IBT users.CASE SUMMARY A 46-year old Caucasian male Veteran(case) with a 21 year history of complete tetraplegia(complete C6 SCI) was implanted with IBT for 20 years. The case was matched to two participants with different time since injuries [2(match 1) and 13(match 2) years] without IBT. Knee BMC and BMD at the epiphysis and metaphysis of the distal femur and proximal tibia were evaluated using dual knee and the dual femur modules of GE Lunar i DXA software. Total and leg body composition assessments were also conducted for the three participants. Potential effect of long-term IBT was demonstrated by changes in BMD, consistent with bone demineralization, at the distal femur and proximal tibia and changes in percentage fat mass and lean mass of legs. The case showed 113% lower BMD at the distal femur, and 78.1% lower at the proximal tibia compared to match 1, moreover the case showed 45% lower BMD at the distal femur, and no observed changes at the proximal tibia compared to match 2. The case had 27.1% and 16.5% greater leg %fat mass compared to match 1 and match 2, respectively. Furthermore, the case had 17.4% and 11.8% lower % leg lean mass compared to match 1 and match 2, respectively.CONCLUSION Long-term IBT may impact bone health and body composition parameters in persons with complete SCI. It may be prudent to encourage regular screening of individuals on long-term IBT considering the prevalence of osteoporosis related fractures, cardiovascular diseases, and metabolic disorders in this population.     

胫骨远近端骨膜外截骨延长修复胫骨缺损的临床X线研究

目的 探讨应用环形外固定架对胫骨远近干骺端进行骨膜外截骨延长成骨的临床影像学研究.方法 收集临床治疗的44例患者并分为两组,A组经胫骨近干骺端骨膜外截骨延长,B组经胫骨远干骺端骨膜外截骨延长,术后第7天开始延长外固定架,分别于不同时段拍摄X线片观察延长区成骨,比较两组间的差异.运用Enneking系统对两组下肢功能进行评分比较,比较两组间的差异.结果 术后随访6个月～2年,在X线片上观察胫骨近干骺端截骨延长较远干骺端截骨延长早期有更为明显的成骨现象,随着时间推移,牵张间隙新生骨密度影像也由低向高增加,两组差异性逐渐减小.下肢功能两组无统计学差异.结论 环形外固定架胫骨近干骺端骨膜外截骨延长有利于早期活跃性成骨作用.     

计算机导航辅助下切除四肢干骺端恶性肿瘤保留自体关节的安全性及长期随访疗效评估

目的 探讨计算机导航辅助下切除四肢干骺端恶性肿瘤保留自体关节的安全性及长期随访疗效。方法 选择2007年1月至2011年9月10例四肢关节干骺端IIB期恶性肿瘤患者,其中7例骨肉瘤,3例尤文肉瘤。术前薄层CT扫描数据和MRI数据输入计算机导航系统进行图像融合,术中用导航探头经过导航跟踪器将手术部位和导航计算机建立联系,然后用导航探头在固定的解剖定位点或术前制作的人工标记点进行计算机注册,再在骨暴露表面散在选择50个点注册增加图像和手术部位配准的准确性,验证若匹配误差小于1 mm则可用于术中导航。然后在导航指导下精准截骨切除肿瘤,腓骨瓣复合异体骨重建肿瘤切除后的骨缺损,术后定期随访,评估保留关节功能、有无肿瘤局部复发及相关并发症等。结果 术中计算机导航匹配误差平均为0.41 mm,导航下截骨线与肿瘤边缘之间的平均距离为9.9 mm,术后平均随访140个月,除1例肿瘤肺转移死亡外,其余所有患者均无瘤存活,所有患者均无局部肿瘤复发,肢体MSTS评分平均为27.8分。结论 导航辅助下可做到肿瘤精确切除,使关节结构保留最大化的同时保证肿瘤不复发,而保留的自体关节使得患者可以长期使用。     

对大骨节病干骺端凹陷、硬化、增宽x线征的几点新认识

作者通过对活跃病区10岁以下大骨节病儿童连续五年(4次/年)的 x 线自然追踪观察,看到了干骺端病变随着年度的变化可以出现多次的反复;凹陷、硬化、增宽的影像可以持续多年不变或持续加重。从 X 线形态学角度提出干骺端病变的发生和发展,修复和进展与病区致病因子的活跃程度、作用时间有密切关系,干骺端病变的凹陷、硬化、增宽在 x 线上不应视为疾病好转的影像,而应视为加重的影像,它依然是本病防治效果判定及病区类型划分最重要、最可靠的指标。     

The periphysis and its effect on the metaphysis: I. Definition and normal radiographic pattern

The zone of Ranvier and the ring of LaCroix, together with the membranous bone bark they produce, are termed the periphysis in order to emphasize their normal effect (the metaphyseal collar) on the metaphysis of the infant and young child. In the first 7 years of life, the normal collar at the wrist is 1–3 mm wide. The step-off between the metaphyseal collar and the curvilinear metaphysis, at the margin of the periphysis, should not be mistaken for abuse fracture. The periphyseal bone bark may be radiologically visible at the edge of the physis at the distal ulna in 9% of infants and should not be mistaken for fracture or rickets.     

Metaphyseal pattern: Uniqueness of this structure in growing bones originating from cartilaginous anlage. A microradiographic study

Summary Microradiographic examination of metaphyses in long and short tubular growing bones allowed detection of a repetitive, clearly defined pattern of three adjacent zones; the latter are successively formed by the mineralization of cartilaginous longitudinal intercolumnar septa and by the subsequent apposition of other mineralized tissues concurrently with resorption. Consequently, each zone of the metaphysis includes mineralized tissues of various compositions and ages, identifiable by their different mineralization densities. Microradiography of pieces of the growing skeleton in several animal species shows that the same organization is not only present in long and short tubular bones but also in many other such as the pelvis and scapula, cuboid bones like the calcaneum and talus, and cartilaginous bones at the base of the skull. This suggests that there is no difference between the osteogenesis pattern of these bones and tubular ones. The problem of identifying the factors generating such metaphyseal organization is raised.     

Effect of grape seed proanthocyanidins extract on alteration of mechanical properties of metaphysis tibia bone in rats fed a low-calcium diet

The effects of grape seed proanthocyanidins extract (GSPE, 3 mg in 100 g of high-calcium diet with a calcium content of 1697 mg/100 g) on rat metaphysis tibia formation following feeding of a low-calcium diet (30% of calcium in the standard diet) were investigated by examining bone density, mineral content, geometric and bone strength. Five-week old male Wistar rats (n = 40) were randomly divided into a control (Co) group, a low-calcium diet (LC) group, a low-calcium diet • high-calcium diet (LCH) group, and a lowcalcium diet • high-calcium diet with supplementary GSPE (LCHG) group. The metaphysis tibia bones were analyzed using three-dimensional peripheral quantitative computed tomography (pQCT), while whole tibia bones were tested for mechanical resistance using a material testing machine. We found no significant differences in body weight among the 4 groups. All bone parameters in the LC group were significantly lower than these in the Co group (P < 0.01). Furthermore, trabecular bone density (TrBD), trabecular bone mineral content (TrBMC), cross-sectional moment of inertia to the reference axis y (yCSMI), and stress-strain index to the reference axis x (xSSI) in the LCHG group were significantly higher than those in the LCH group (P < 0.05; P < 0.01; P < 0.05; P < 0.05, respectively), while stiffness in the LCHG and LCH groups were significantly higher than that in the LC group (P < 0.01). We concluded that a mixture of high-calcium and GSPE in the diet has a more beneficial effect on bone formation for the treatment of metaphysis tibia bone debility in rats than does a high-calcium diet alone.     

Time-related changes in the ultrastructure of osteoclasts after injection of parathyroid hormone in young rats

Summary The effects of parathyroid hormone (PTH) on the size of the osteoclasts, nuclei, ruffled borders, and clear zones in long bones of thyroparathyroidectomized (TPTX) rats were quantitated as a function of time. These data were compared with the number of osteoclasts in the bone and with plasma calcium levels. A significant increase in the average size of the ruffled borders was demonstrated 30 min after injection of 50 U of purified bovine PTH, and of the clear zones 30–90 min after PTH. This was followed at 90 min by an increase in the average size of the cells. The sizes of ruffled borders and clear zones dropped sharply to control levels after 6 h, whereas the size of the cells remained elevated up to 12 h and returned to control values at 24 h. Plasma calcium levels were increased, but not significantly, between 30 min and 6 h. An increase in the number of osteoclasts was significant after 12 h. Removal of the parathyroid glands did not diminish the normal activity of osteoclasts. In animals with intact glands injection of 50 U of PTH did not cause a significant change in cell size or resorbing apparatus. It is concluded that PTH acts to rapidly stimulate the bone resorptive activity of osteoclasts and to cause a delayed increase in their number.     

A quantitative histologic analysis of the growing long bone metaphysis

Summary The purpose of this work was to analyze the proximal tibial metaphysis of the 170 g rat in a quantitative histologic fashion which would allow some relation to tissue age to be established. Stained 3 μm thick tissue sections were analyzed with the aid of a Merz grid on an eyepiece reticule and a light microscope. Tissue mass and cell distribution were studied in all areas. The rate of change in tissue mass during aging of the metaphysis was calculated. Two regions of the metaphysis were identified. One, corresponding to the primary spongiosa, less than 4.45 days of age, is a region of high turnover of hard tissue and high numbers of osteoblasts and osteoprogenitor cells. The other, corresponding to the secondary spongiosa, is a region of relatively low net tissue turnover and low numbers of osteoblasts and osteoprogenitor cells. Osteoclasts were found relatively more uniformly distributed through the metaphysis than were osteoblasts and osteoprogenitor cells. The rate of bone formation in the primary spongiosa is 50 times that found in the Haversian bone of the rib of 5-year-old humans and about 500 times that found at the cortical-endosteal surface of ribs of 5-year-old humans. It is argued that both cell distribution and tissue distribution in the metaphysis support the concept that osteoblasts and osteoclasts, rather than osteocytes, are responsible for the maturation of the metaphysis. The inhomogeneous distribution of both cells and tissue in the metaphysis has definite meaning for the interpretation of findings concerning the incorporation of radionuclides into the skeleton.     

Metadiaphyseal chondroblastoma of the thumb

Chondroblastoma is typically located in the epiphysis. Predominant metadiaphyseal location is very rare, as is involvement of the digits. We describe a case of chondroblastoma involving the metadiaphysis of the thumb. The patient was a 13-year-old boy who presented with pain and swelling of his left thumb. Radiographs showed an expanded lytic lesion involving the whole metaphysis and diaphysis of the proximal phalanx, which subsequently progressed to involve the epiphysis. Curettage and bone grafting were done. Received: 9 July 1999 Revision requested: 12 August 1999 Revision received: 1 November 1999 Accepted: 4 November 1999