Haemodynamics as a determinant of the pharmacokinetics of and the plasma catecholamine responses to isoprenaline

Summary The total body clearance and fractional extraction of isoprenaline (ISO) have been determined, and the relation between these parameters and cardiac output established. Whether desipramine, an inhibitor of neuronal uptake, altered the plasma catecholamine response to ISO was also investigated.Seven healthy subjects were given i.v., infusions of ISO in two, consecutive 25-min periods, at constant dose rates of 31–43 and 80–124 pmol·kg^–1·min^–1, respectively. The total-body (ER), pulmonary (ER_p) and forearm (ER_f) fractional extractions and the total body clearance (CL) of ISO were obtained from measurements of cardiac output and the steady-state ISO concentration in mixed central venous, arterial and forearm venous plasma.ISO-induced increases in cardiac output resulted in increases in CL, decreases in ER and no consistent change in ER_f. ER_p did not differ from zero. ISO also produced a dose-dependent increase in the mixed venous plasma concentrations of noradrenaline and 3,4-dihydroxyphenylglycol (DOPEG), and a decrease in that of adrenaline. Pretreatment with desipramine did not alter any of the pharmacokinetic parameters of ISO. Desipramine, however, reduced the mixed venous baseline plasma levels of noradrenaline (47%) and DOPEG (40%), and tended to reduce that of adrenaline (34%). It enhanced the plasma noradrenaline response 2.4-fold, abolished the plasma DOPEG response and did not alter the plasma adrenaline response to ISO.Hence, owing to its haemodynamic effects, ISO modifies its own pharmacokinetics which involve non-neuronal removal processes only. The increased DOPEG in plasma resulting from the ISO-induced increase in noradrenaline release was presynaptic in origin. Desipramine appears to reduce sympathetic activity. The enhancement by desipramine of the ISO-induced increase in plasma noradrenaline points towards recapture by neuronal uptake of at least 58% of the noradrenaline released in response to ISO.     

Bone mineral density of the proximal tibia following uncemented arthroplasty

Bone mineral density (BMD, g/cm2) was measured using dual-photon absorptiometry (DPA) in selected areas of the proximal tibia following uncemented PCA knee prosthesis. In nine patients with 14 alloplastic operations, measurements were taken at 3-6-month intervals for the first 3 1/2 years after operation. There was a significant increase in BMD of about 15% during the first 6 months after operation. The following year it remained increased, although not significantly, compared with the initial values, then gradually diminished. Increased bone density after arthroplasty may be explained mainly by stimulation of bone formation from weight bearing due to improved walking ability. Stress shielding of the proximal part of the supporting tibial bone did not seem to occur.     

全营养素混合液(TNA)在肠外营养的应用

脂肪乳剂、葡萄糖、氨基酸、电解质、维生素及微量元素按一定程序混合配成10种全营养素混合液。在4℃14天贮存期内,10种混合液的pH和渗透压变化不大,不同混合液在不同时期的脂粒平均直径变化为0.3135±0.1012μm～0.4813±0.1893μm,94.93％脂粒的直径<0.6μm,无直径>6μm的脂粒,细菌培养阴性。74例共输全营养素混合液1,796次,无不良临床反应和异常实验室检查结果;用1周以上者大都显示氮平衡改善,用2周以上者血清转铁蛋白和白蛋白浓度可有不同程度升高。     

胫骨高位截骨对胫骨近端解剖形态的影响

[目的]测量胫骨高位截骨术后胫骨近端解剖形态,并与术前比较,探讨其变化的临床意义.[方法]2001～2005年,35例(59膝)因膝关节内侧室骨性关节炎接受胫骨高位截骨术患者的完整影像学资料,在术前、术后标准正侧位X线片中测量胫骨角;胫骨后倾角度;胫骨近端关节面外移;关节线高度.所得资料采用配对t检验进行统计学分析,以P＜0.01为差异有显著性意义.[结果]胫骨角术前平均为99.1°±4.3°,术后平均为91.1°±3.8°;胫骨后倾角度术前平均为8.9°±2.6°,术后平均为5.0°±2.3°;胫骨近端关节面外移术前平均为(46.2±3.6)%,术后平均为(53.1±3.9)%;关节线高度术前平均(41.2±3.6)mm,术后平均(38.0±3.2)mm.手术前后差异均有显著性意义(P＜0.01).[结论]胫骨近端解剖形态在胫骨高位截骨术后会发生明显变化,如胫骨角变小,后倾角度变小,胫骨近端关节面外移,关节线高度相对下降等,将对转行全膝关节置换术产生不良影响.     

Digital mucoid cyst excision by using the bilobed flap technique and arthroplastic resection

There are a number of proposed causes and treatment approaches for digital mucoid cysts. The described treatment outcomes for this cyst have been variable, with the highest success rate reported with complete excision and single-lobe skin flap closure. This report describes a bilobed flap reconstruction in conjunction with resection of the head of the middle phalanx. A retrospective review was undertaken to evaluate the recurrence rate, complications, and patient satisfaction with this combined procedure. Fifteen patients with an average follow-up of 4.6 years were evaluated. There were no recurrences, flap failures, or other major complications. The use of this flap allows for greater exposure than traditional semi-elliptical incisions while allowing the wide excisional defects to be closed primarily.     

Computerised and technical navigation in total knee-arthroplasty

Abstract The objective of the study was to evaluate the precision, concordance, practicability and the early clinical outcome of the use of a computerised navigation system in a comparative study with a group of 100 patients. Two groups of 50 patients each underwent implantation of a bicondylar knee prosthesis either by means of the freehand navigation system or by means of technical instrumentation. We found that the computerised navigation system provided a higher precision than the technically instrumented implantation: 94% of the prostheses implanted with the navigation system have an alignment within a range of -3° to 3° on of the Mikulicz line. Only 46% of the patients operated by means of the technical instrumentation reached this aspired result. Furthermore, the navigation system showed smaller ranges in the deviation of the aspired alignment. The radiological and computer-modeled alignment values differed both pre- and postoperatively, but to a larger extent before surgery. The varus or valgus deviations of the axis were more distinct radiologically under the weight of the patient’s body than in the computer model. The clinical outcome examined by the use of the HSS score after a mean followup of 7 months is good in both groups, and without significant differences. On average, the duration of surgery was 13 minutes longer in the computerised navigation group. We conclude that the benefit of the computerised navigation system is represented by the high improvement of precision. Achieving early clinical results identical to those in the technical instrumentation group, we expect a reduction of aseptic loosening in the computerised navigation group.     

Trapeziometacarpal joint osteoarthritis: a retrospective study comparing arthrodesis to tendon interposition arthroplasty

Abstract Surgical management of trapeziometacarpal joint osteoarthritis (OA) is still controversial. The aim of this study was to evaluate and compare results of trapeziometacarpal arthrodesis and of tendon interposition arthroplasty. One hundred twenty-six patients suffering from trapeziometacarpal OA underwent surgery between 1996 and 2001. Of these patients, 62 (78 thumbs) treated with joint arthrodesis and 33 (41 thumbs) treated with tendon interposition arthroplasty with abductor pollicis longus (APL) have been evaluated at follow-up and therefore entered this study. Mean age was 53 years, while the mean follow-up was 36 months. Overall results were satisfactory in 84 patients with good pain improvement. Patients treated with arthrodesis showed better functional ability in bi-digital pinch and grip strength. First finger opposition motion, however, was better conserved in patients treated with interposition arthroplasty. Fusions had an 11.5% complication rate (9 thumbs) with nonunions, whereas 14.8% (6 thumbs) of patients treated with interposition arthroplasty developed 1 first metacarpal base collapse, resulting in 1 first ray length reduction. Despite complications, however, patients did not report unsatisfactory results and generally experienced marked pain reduction. This study shows that arthrodesis can be considered the treatment of choice in patients suffering from trapeziometacarpal OA at Eaton stage III or less, whatever the age and when a good pinch strength is needed.     

微创与切开复位接骨板内固定治疗膝关节内骨折的比较

[目的]比较研究微创接骨板内固定和切开复位接骨板内固定对膝关节内骨折的治疗效果,探讨生物学内固定在膝关节内骨折中的使用价值.[方法]总结近年来根据生物学固定原则,以微创接骨板固定术(MIPO)治疗的膝关节内骨折共21例.以创伤类型及年龄等因素进行配对,选择切开复位内固定(ORIF)治疗的病例资料比较手术及术后恢复情况.采用HSS评分评价结果.[结果]MIPO组随访10～16个月(平均14.2个月),有2例进行骨移植术,平均手术时间60.0 min,术中失血量45.0 ml,平均骨折愈合时间10.0周,3例有5°以上膝内、外翻畸形,HSS功能评分平均86.67分;ORIF组经过12～48个月(平均21.2个月)随访,有18例进行骨移植术,平均手术时间79.52 min,平均术中失血量117.1 ml,平均骨折愈合时间12.24周,2例发生5°以上膝关节内、外翻畸形,HSS功能评分平均82.14分.两组均获得骨愈合,没有感染和内固定断裂等并发症发生.比较发现两组患者在手术时间、术中失血量、骨折愈合时间和功能恢复方面差异有统计学意义.[结论]对于合适的膝关节内骨折病例以微创接骨板内固定治疗可以降低植骨需求和术中失血,在手术过程和术后恢复方面有明显优势.     

The patella and tibial condyle position after combined and after closing wedge high tibial osteotomy

High tibial osteotomy changes the patella and tibial condyle position, which makes the subsequent total knee replacement technically demanding. From 1 January 1993 to 31 December 2000, combined osteotomy [After the first osteotomy made 2 cm distally to the joint line, a bone wedge is removed based laterally. Its tip ends at the center of the tibial condyle (half bone wedge). The distal part of the tibia is placed into the valgus position and the half bone wedge is placed into the gap opened medially.] was performed on 103 knees and closing wedge osteotomy was performed on 47 consecutive knees. Eighty combined (group A) and 41 closing wedge (group B) osteotomy were studied. All knees were assessed radiologically before surgery, in the 10th postoperative week, in the 12th postoperative month and at the time of the final follow-up (in group A—66.15 months, in group B—66.61 months). We examined the change of the femorotibial angle, of the patellar height according to the method of Insall and Salvati, of the tibial slope angle according to the method of Bonnin, of the tibial condylar offset according to the method of Yoshida and of the distance between the lateral tibial plateau and the top of the fibular head. In group A and B, the recurrence of the varus deformity was not noted and valgus alignment did not increase in any case. In group-A, the Insall–Salvati ratio remained unchanged in 65% of knees. The tibial slope angle decreased in both groups. There was correlation between the change of the tibial condylar offset and the angle of the correction in both groups. There was correlation between the change of the distance between the lateral tibial plateau and the top of the fibular head. After combined osteotomy, the transposition of the tibial condyle and the decrease of the distance between the lateral tibial plateau and the top of the fibular head was less than after closing wedge osteotomy, although the average angle of correction was more after combined osteotomy (11.835°), than after closing wedge osteotomy (9.465°). Theoretically, the recurrence of the varus deformity, the increase of the valgus alignment and (in majority of cases) the shortening of the patellar tendon do not compromise the likelihood of successful conversion to the subsequent total knee replacement, either after combined or after closing wedge osteotomy. The combined osteotomy does not lead to considerable transposition of the tibial condyle and to considerable lateral tibial bone loss; therefore, theoretically, the combined osteotomy does not impair the subsequent total knee replacement.