Polylactic acid (PLA) root replica in ridge maintenance after loss of a vertically fractured incisor

Abstract A periodontally affected tooth was prepared for a special treatment: Calcium hydroxide was introduced into the apical half of the root canal whereas its cervical part was filled with glass ionomer cement. The tooth was shortened subgingivally. After 6 weeks of epithelization over the residual root a palatal full-thickness flap was mobilized. The root was carefully extracted and chairside copy-milled from the biodegradable polylactic acid (PLA) material. The PLA-replica was implanted immediately into the socket and the flap was sutured. Aim of the treatment was to prevent the ridge collapse of the extraction area. Ridge height could be preserved during the 21 months of observation. With time the radiographic density of the cancellous bone increased in the implanted area, indicating that a PLA-replica is replaced by host's bone tissue.     

Hip fracture incidence in the canton of Vaud,Switzerland, 1986–1991

The objective of this study was to estimate the incidence of hip fracture in the canton of Vaud, Switzerland (total population 584 000), for the period 1986–1991 using routine hospital discharge data collected by the Cantonal Service of Statistical Research and Information (SCRIS). For the survey period, the estimated average annual crude incidence rate of hip fractures was 167 per 100 000 persons aged 20 or older (241 for women and 84 for men). For the population aged 50 years or older, the crude incidence rate was 388 per 100 000 persons (546 for women and 185 for men). The average annual age-specific rates rose exponentially by successive 5-year age groups. The median age of patients at the time of the fracture was 82 years in women and 74 years in men. There was no significant difference between the total number of cervical and trochanteric fractures. Between the ages of 20 and 84 years, the cumulative risk for a woman to be admitted to hospital with a hip fracture was twice that of a man (15.8% vs 7.8%). From 1986 to 1991, the age- and sex-adjusted incidence, like the ratio of cervical to trochanteric fractures, did not show any significant trend, although it was consistent with an increase in men (p=0.09). However, the annual number of fractures rose from 644 to 776, particularly among very aged men. The mean length of stay in the acute care hospital fell from 38 days in 1986 to 25 days in 1991. Finally, the comparison of these results with those obtained in 1986 for the same population from more exhaustive sources has confirmed the provision of a consistent, although overestimated, assessment of hip fracture incidence by means of these routine hospital statistics in the canton of Vaud, Switzerland.     

Differences in hip axis and femoral neck length in premenopausal women of Polynesian, Asian and European origin

There are substantial inter-racial differences in hip fracture incidence. Studies in several different ethnic groups have suggested that differences in the length of the femoral neck may contribute to these. The present study assesses femoral neck and hip axis lengths in three ethnic groups in which it has not been documented previously (Chinese, Indians and Polynesians) and compares these values with those in Europeans. Lengths were measured from dual-energy X-ray absorptiometry scans of the proximal femur in normal premenopausal women (n=225). The Polynesian (1.65 m) and European (1.64 m) women were significantly taller than the two Asian groups (mean height in each, 1.58 m). There were also differences in mean body weight, the Polynesians being the heaviest (76 kg) and the Chinese the lightest (53 kg). Femoral neck lengths were (mean + SD) Chinese 61.5+4.4 mm, Indian 61.5+5.1 mm, Polynesian 68.2+4.3 mm and Europeans 66.0+4.8 mm. Hip axis lengths were Chinese 98.0+5.6 mm, Indian 94.5+5.2 mm, Polynesian 106.4 ± 5.3 mm and European 102.3+5.3 mm. Each of the other groups were significantly different from the Europeans for both variables and, in general, this remained so after height adjustment. These data suggest that shorter femoral necks are common to the major Asian racial groups. However, in contrast to all other ethnic groups studied, Polynesians have longer femoral necks than Europeans and their low incidence of hip fracture is not explicable, therefore, in terms of their femoral neck length. This suggests that either higher bone density or other more subtle differences in proximal femoral geometry must account for the low hip fracture incidence in Polynesians.     

Short-term lack of cerebral perfusion with good outcome. Advantages of early intracranial pressure monitoring

A 21-year-old man was injured by a tailboard of a truck. He suffered a severe head injury with bilateral depressed skull fractures necessitating surgical decompression. On admission to the hospital the patient showed bending to pain stimuli (Glasgow Coma Score 5). Anisocoria was noticed from the beginning. Initial intracranial pressure (ICP), measured 3 hours after injury, was 30 mm Hg, and the cerebral perfusion pressure (CPP) was 70 mm Hg. During surgical elevation of the skull fracture on the right side an unexplainable rise of ICP to values of 100 mm Hg occurred, which corresponded to the mean arterial blood pressure (MAP). At the same time both pupils were dilated and fixed indicating a lack of cerebral perfusion. Due to immediate trephination of the opposite side, the ICP was lowered to values below 20 mm Hg, and sufficient cerebral perfusion (above 50 mm Hg) was regained. The patient showed a good recovery and was transferred to a rehabilitation center 5 weeks after injury.This case report emphasizes the importance of early and continuous intracranial pressure monitoring for adequate therapy in neurosurgical emergencies.     

尺骨鹰嘴骨折皮质骨加压螺钉固定的实验研究及临床应用

比较尺骨鹰嘴骨折加压螺钉与常用的4种内固定的强度,为临床选择内固定方法提供实验依据。用22具新鲜尸体肘关节做成横型、斜形和粉碎形鹰嘴骨折模型。用5种内固定后置于MD—10E万能电子力学试验机上,测定骨折处的位移与压力的关系;结果:钢丝内固定强度最小,钩钢板最大。髓内加压螺钉固定欠可靠。横形骨折皮质骨加压螺钉与张力带钢丝比较,统计学上无显著差异(P〉0.05),斜形骨折皮质骨加压螺丝钉强于张力带钢丝(P〈0.01)。粉碎形骨折使用钩钢板尤佳(P〈0.01)。临床应用24例中,22例平均随访14个月。骨折全部愈合,优良率达90.91％;认为皮质骨加压螺丝钉治疗横、斜形尺骨鹰嘴骨折,创伤小,操作简便,固定确切,是一种安全可靠的方法。     

24例骨折术后深部感染的原因及对策

目的 探讨骨折术后深部感染的原因、预防和治疗方法。方法 对骨折术后深部感染病灶行扩创后置管闭合灌洗。结果 24例经清创闭合灌洗平均27．5d后，感染均得以控制，效果满意。结论 骨折手术后深部感染原因是多方面的，宜积极预防，早期发现，及时扩创闭合灌洗，遗留肢体功能障碍者留待后期治疗。     

Doppler-sonographische durchblutungsmessungen der unteren extremität des menschen

Summary A duplex ultrasound system was used to examine the blood flow of the common femoral artery in ten young patients with fractures of the lower extremities. Two patients had fractures of both legs. In eight patients the blood flow in the injuried leg was comparable with that in the not injured leg. The flow alterations were measured on 3–7 different days over a period of 6–224 days after trauma. All patients showed a significant (to twice or three times that before injury) increase in blood flow in the injured leg a few days after trauma and/or operation, whereas the blood flow in the uninjured leg remained the same or even decreased a little. In the case of undisturbed fracture healing the change in blood flow disappeared within 8–12 weeks, corresponding to fracture consolidation. When fracture healing was delayed and/or further operations on the injured leg were necessary, the blood flow was increased for much longer. The hemodynamics of an injured extremity are compared with those reported elsewhere in the literature. The increased demand for oxygen or energy can explain the changes only in part. Another function of the reflective increase in blood flow could be the temperature increase in the extremity.

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Doppler-sonographische durchblutungsmessungen der unteren extremität des menschenII. Hämodynamik nach trauma und operation

Zusammenfassung Mittels Doppler-sonographischer Durchblutungsmessung wurde die Hämodynamik der verletzten Extremität an 10 jungen Patienten mit Frakturen der unteren Extremität untersucht. Bei 8 Patienten konnte die Durchblutung des verletzten Beins mit der unverletzten Gegenseite verglichen werden. Die Messungen erfolgten an 3–7 verschiedenen Tagen in einem Zeitraum von 6–224 Tagen nach dem Unfall. An allen verletzten Extremitäten steigt die Durchblutung wenige Tage nach dem Unfall und/oder der Operation deutlich um das 2- bis 3fache an, während die Durchblutung des unverletzten Beins niedrig bleibt. Bei einem ungestörten klinischen Verlauf sinkt die Durchblutung in 8–12 Wochen wieder. Heilungsstörungen und weitere Operationen an dem Bein verzögern diese Normalisierung deutlich. Diese Ergebnisse werden mit anderen Untersuchungen der Literatur verglichen. Ursache und Funktion der hämodynamischen Änderungen könnte u. a. in einer reflektorischen Temperaturerhöhung zu sehen sein.

     

胫骨应力骨折(附30例临床X线诊断分析)

本文对30例(31个)胫骨应力骨折进行了临床、X线征象分析。并对其发生机制,诊断及鉴别诊断中的一些问题进行了讨论。     

经椎弓根减压固定和植重组异体骨治疗脊柱脊髓损伤

目的 :探讨严重脊柱脊髓损伤经一侧椎弓根和椎体后缘复位减压 ,经椎弓根植重组异体骨和椎弓根钉固定的可行性及效果。方法 :经一侧椎弓根和椎体后缘复位或截骨减压 ,用特制环锯套管经椎弓根植重组异体骨 ,以X线片和CT片分类分型 ,评估手术前后骨折复位减压和植重组异体骨融合效果 ;按Frank分类标准评估脊髓损伤和恢复程度。结果 :除A级病人外 ,其他病人脊髓神经功能均进步 1～ 2级 ,无感染和断钉病人 ,脊柱后凸角度矫正后再丢失平均 3° ;部分病人术后早期对重组异体骨有反应 ,但几周后可消失。结论 :经一侧椎弓根椎体后缘复位或截骨减压 ,同样可达到较理想脊髓减压效果 ,经椎弓根植重组异体骨和椎弓根钉固定简单、安全、有效。