骨水泥阻塞骨干髓腔后远侧骨干骨内压和骨血流改变的实验研究

[目的]探讨骨水泥阻塞股骨近中段骨干髓腔后对股骨远端骨内压和骨血流的影响.[方法]采取兔左侧股骨髓腔内灌注PMMA骨水泥而右侧不灌注作为正常对照的方法,制作骨水泥阻塞股骨近中段骨干髓腔的兔动物模型.将32只实验兔分成5组,随机取出8只不做模型作为正常对照组,其余24只制作模型后,根据不同的观察时间段随机分成术后当天（T0）、术后4周（T4）、术后8周（T8）、术后16周（Ti6）4个观察组,每组6只.使用生理测压仪,对正常和模型动物双侧股骨远端骨内压进行测量和比较.采用核素骨显像（ECT）方法,对模型动物双侧股骨远端动态和静态显像进行检测和比较.[结果]（1）骨内压：正常兔股骨远端双侧骨内压无差异性（P＞0.05）：T0、T4、T8、T16实验侧骨内压明显增高,双侧有差异性（P＜0.01）.造模后在不同观察时间段对照侧骨内压均无差异性（P＞0.05）,实验侧处于持续骨内高压状态,T0与T4、T0与T8、T0与T16、T4与T8、T8与T16均无差异性（P＞0.05）,T4与T16有差异性（P＜0.05）;（2）核素骨显像：T0、T4实验侧核素计数均比对照侧明显降低,T8、T16实验侧核素计数均超过对照侧,T16最高;各时间段实验侧/对照侧核素计数比值中T0与T8、T0与T16、T4与T16、T8与T16、T4与T8均有差异性（P＜0.05）,而T0与T4无差异性（P＞0.05）.核素骨动态和静态显像的变化趋势完全一致.[结论]骨水泥阻塞股骨近中段骨干髓腔后严重破坏了骨内和髓内的血液循环状态,引起了局部血流动力学的改变.导致股骨远端的骨内压和骨血流发生了一系列的变化,骨内压持续升高并长期存在.     

Transcutaneous measurement of femoral artery flow

The measurement of femoral artery blood flow in normal subjects has been accomplished using transcutaneous ultrasonic techniques. The calculation of volume flow depends upon the determination of arterial diameter and mean flow velocity. Arterial dimensions were measured using an echo tracking system which permits identification of the near and far walls of the vessel and its diameter. Flow velocity was measured from the frequency shift that occurs when ultrasound encounters the moving particles in blood. The calculated volume flows agree with those reported using the indicator-dilution methods. The limitations of the present method are discussed.     

Geometry, blood flow, and reconstruction of the deep femoral artery.

The deep femoral artery is the main source of blood supply to the leg and foot when the superficial femoral artery is occluded. In this situation, the geometry of the trunk of the deep femoral artery represents a stenosis of 50 per cent interposed between the common femoral artery and the collateral circuit of the deep femoral artery. Intimal thickening of only 0.5 and 1.0 mm increases this anatomic stenosis to 64 and 76 per cent, respectively. Beyond the trunk, the cross-sectional area of the deep femoral artery circuit increases at each arterial division. Any reconstruction of the deep femoral artery intended to increase its inflow must extend down to at least its first important bifurcation if it is to overcome this trunk "stenosis". This requirement ex plains the effectiveness of proper reconstruction of the deep femoral artery in avoiding or delaying amputation in patients with ischemic symptoms and occlusion of the superficial femoral artery who are not candidates for femoropopliteal reconstruction. In this group, the absence of plaque on the arteriogram does not contraindicate reconstruction.     

Effect of femoral profundaplasty on blood flow

The effect of femoral profundaplasty on blood flow in the lower limb was examined. In 15 patients with signs and symptoms of femoropopliteal artery occlusion, the following measurements were made before and after profundaplasty with vein-patch graft: ankle pressure index, muscle blood flow at rest and with maximal exercise (xenon clearance technique), and blood flow in the calf and in the great toe (venous occlusion plethysmography). No significant change was found in resting muscle blood flow, or in the results of calf or toe plethysmography. Muscle blood flow was significantly (p less than 0.01) increased 1 minute after maximal ischemic exercise (6.3 +/- 2.0 ml/100 g X min-1 before operation and 10.4 +/- 3.9 after) and the time to reach peak muscle blood flow after tourniquet release was significantly reduced (p less than 0.01) after operation, from 149 +/- 52 to 102 +/- 46 seconds. Ankle pressure index was unchanged by profundaplasty (0.63 +/- 0.17). All of the six patients with claudication were subjectively improved, and in seven of the nine patients with foot ischemia the limb was saved. The changes in blood flow help to explain the clinical improvement noted after profundaplasty.     

Delayed distal blood pressure rise after partial arterial reconstruction for combined aorto-iliac and superficial femoral artery occlusive disease

The blood pressure in the ankle and great toe was measured with cuff and strain-gauge technique in 39 patients after insertion of aorto-femoral bifurcation graft. In 40 limbs with patent superficial femoral artery (complete reconstruction) the distal blood pressure remained unchanged from the tenth postoperative day to follow-up after 12 to 26 months. In 30 limbs with occluded superficial femoral artery (partial reconstruction) the ankle/arm pressure index rose from 0.54 to 0.61 between the tenth day and late follow-up. The blood pressure in the great toe had increased by 8 mmHg on the tenth postoperative day and by additionally 17 mmHg during the next 12 to 26 months. The delayed pressure rise after partial arterial reconstruction presumably reflected development of collateral vessels from the deep femoral artery system. The clinical significance of the findings is discussed.     

解剖型钢板内固定治疗股骨远端骨折

1999年6月～2005年10月,我院采用Link解剖型钢板内固定治疗股骨远端骨折32例,获得了满意疗效。     

Management of distal femoral periprosthetic fractures by distal femoral locking plate: A retrospective study.

Background:

Management of periprosthetic supracondylar femoral fractures is difficult. Osteoporosis, comminution and bone loss, compromise stability with delayed mobility and poor functional outcomes. Open reduction and internal fixation (ORIF) with anatomic distal femoral (DF) locking plate permits early mobilization. However, this usually necessitates bone grafting (BG). Biological fixation using minimally invasive techniques minimizes periosteal stripping and morbidity.

Materials and Methods:

31 patients with comminuted periprosthetic DF fractures were reviewed retrospectively from October 2006 to September 2012. All patients underwent fixation using a DF locking compression plate (Synthes). 17 patients underwent ORIF with primary BG, whereas 14 were treated by closed reduction (CR) and internal fixation using biological minimally invasive techniques. Clinical and radiological followup were recorded for an average 36 months.

Results:

Mean time to union for the entire group was 5.6 months (range 3-9 months). Patients of ORIF group took longer (Mean 6.4 months, range 4.5-9 months) than the CR group (mean 4.6 months, range 3-7 months). Three patients of ORIF and one in CR group had poor results. Mean knee society scores were higher for CR group at 6 months, but nearly identical at 12 months, with similar eventual range of motion.

Discussion:

Locked plating of comminuted periprosthetic DF fractures permits stable rigid fixation and early mobilization. Fixation using minimally invasive biological techniques minimizes morbidity and may obviate the need for primary BG.     

Common femoral artery volume flow in peripheral vascular disease

Common femoral artery volume flow was measured at rest and during postocclusive reactive hyperaemia in 80 normal subjects and 67 patients with radiological evidence of occlusive peripheral vascular disease. At rest, means(s.d.) common femoral artery volume flow in normal subjects (344(135) ml/min) and all patients with peripheral vascular disease (401(168) ml/min) was not significantly different. During postocclusive reactive hyperaemia, mean(s.d.) peak flow was significantly higher in normal subjects (1951(438) ml/min) than in patients with peripheral vascular disease (996(457) ml/min) (P less than 0.01). Common femoral artery volume flow in patients with critical ischaemia and intermittent claudication did not differ at rest but mean(s.d.) peak flow in patients with critical ischaemia (697(276) ml/min) was significantly lower than in claudicants (1131(447) ml/min) (P less than 0.01). Mean(s.d.) resting common femoral artery volume flow in limbs with femoropopliteal disease (457(185) ml/min) was significantly greater than that in limbs with occlusion of the aortoiliac segment (308(130) ml/min) (P less than 0.01). However, this difference did not persist during postocclusive reactive hyperaemia. A hyperaemic index, calculated from the hyperaemic responses to below knee and whole limb ischaemia, was used to quantify segmental perfusion during postocclusive reactive hyperaemia. The mean(s.d.) value in normal subjects, 46(9) per cent, and in those with aortoiliac disease, 52(12) per cent, indicated approximately equal perfusion of the above and below knee limb segments. In those with femoropopliteal disease the mean(s.d.) hyperaemic index was 17(13) per cent, revealing relative hypoperfusion of the below knee segment.     

A mechanical distal aiming device for distal locking in femoral nails.

Although the free hand technique remains the most popular method for distal interlocking screw insertion, proximally mounted radiation independent devices that compensate for implant deformation recently have been developed for the femur. However, the benefits of such systems have not been determined. This study prospectively compared the duration of the nailing procedure, the length of radiation time, and the accuracy of interlocking screw placement when using a radiation independent distal aiming system with those using the free hand technique. In 20 paired intact anatomic specimen femurs, one surgeon experienced only in the free hand technique performed statically locked intramedullary nailing using the two methods. For the aiming system and free hand technique, respectively, the total operation time was 19.1 +/- 8.4 minutes versus 20.9 +/- 11.3 minutes, the distal locking time was 6.6 +/- 2.4 minutes versus 4.8 +/- 1.5 minutes, the total fluoroscopy time was 23 +/- 17 seconds versus 69 +/- 34 seconds, and the distal locking fluoroscopy time was 0 versus 37 +/- 15.5 seconds. There were no failures in either group. Drill nail contact and distal screw damage were greater with the free hand technique. This study suggests that the main advantages of the aiming arm compared with the free hand technique include the elimination of radiation during distal interlocking and more precise screw placement with decreased insertion related hardware damage.     

A radiographic study of the distal femoral epiphysis

PurposePrevious studies have described the complex undulation pattern in the distal femoral physis. We investigated whether standard radiographs can visualize these landmarks, in order to guide hardware placement in the distal immature femur.MethodsWe studied 36 cadaveric immature femora in specimens 3 to 18 years of age. Anteroposterior (AP) and lateral radiographs were obtained with and without flexible radiodense markers placed on the major undulations and were analyzed to determine the relative height or depth of each topographical landmark. Intraclass correlation coefficients (ICCs) were calculated between measurements taken with and without markers for each undulation on each view.ResultsExamination of the specimens confirmed a central peak and anteromedial and posterolateral valleys as the major physeal structures. AP radiographs without markers correlated well with marked AP radiographs for all three landmarks (ICC = 0.92, 0.92, 0.91), but the lateral radiographs had lower correlations for the posterolateral valley (ICC = 0.36). The correlation between AP and lateral radiographs without markers on the posterolateral valley was also decreased compared to the other two landmarks (ICC = 0.28 versus 0.57 for the central ridge and 0.62 for the anteromedial valley).ConclusionsThis is the first study to rigorously evaluate radiographic visibility of the distal femur physeal undulations. The position of the central ridge, anteromedial valley, and posterolateral valley are reliably seen on AP radiographs, while the lateral view is less consistent, especially for the posterolateral valley. We recommend that caution should be taken when placing screws near the posterolateral aspect of the epiphysis, as lateral views do not visualize those undulations well.