Fiber Matrix Descriptors from Permeability Data Without Requiring Membrane Thickness: Theory,Results, and Optimization

Objective: Permeability of basement membrane and all other barriers contains a term for membrane thickness (Δx). This naturally leads to development of methods for measuring Δx that are imprecise, inaccurate, expensive, subject to preparation artifact, and inattentive to variability. Although height and shape of permeability (P) vs. probe radius (α) curves are sensitive to Δx, ln(P) or ln(P/free diffusivity or D_o) curves have shapes independent of Δx. It should, thus, be possible using such characteristics to determine fiber radius (r_f) and void volume ratio (ε) without Δx. We developed such a method to derive membrane structure by the standard model of Ogston and present its experimental evaluation. Methods: Basement membranes were self-assembled using 1: 1 Matrigel: 0.01 M Tris/150 mM NaCl/1.0 mM CaCl₂ buffer on 0.4-μ polycarbonate supports with transport measured in diffusion chambers using FITC-labeled hydroxyethyl starch probes from 25 to 102 Å in radius. Sampling was at 0.5 hr and then for each hour up to 5. Other membranes were measured 7 days after formation. Results: The best fit of the new technique occurred at 3 hr with R² = 0.949 ± 0.003 SEM, r_f = 36.8 ± 2.4 Å, and ε = 0.87 ± 0.02. Membranes studied for 7 days showed more variability but essentially the same characteristics. Conclusions: Membrane thickness is not necessary to reduce permeability of basement membrane to structure, and optimum sampling time is 3 hr.     

Erfahrungen zur PFFB von isolierten radiusköpfchenfrakturen

Zusammenfassung Den Vorteilen einer osteosynthetischen Versorgung einer Fraktur mit sofortiger Aufnahme seiner Funktion, stehen die aus der Literatur bekannten Komplikationen gegenüber. Diese und unsere eigenen unbefriedigenden Ergebnisse nach der operativen Versorgung von Radiusköpfchenfrakturen ließen uns zu einer prospektiven randomisierten Studie einer primär funktionellen Behandlung unter Verzicht auf eine äußere oder innere Stabilisierung greifen. Seit Dezember 1991 haben wir im UKH-Graz bis einschließlich Dezember 1992 insgesamt 70 Patienten nach einem strikten Behandlungskonzept, unter Zuhilfenahme der Computertomographie zur Verlaufsbeobachtung versorgt. Die in 91% der Fälle als sehr gut and gut einzustufenden Frühergebnisse sowie das fehlende Auftreten einer, wie bei operativer Versorgung möglichen Komplikation, ebenso die zusätzlich deutlich frühere Arbeitsfähigkeit bzw. deutlich kürzere, wenn auch aufwendigere Behandlungszeit, lassen uns diese Verfahren nicht nur in unserem Hans weiterführen, sondern können wir auch weiter empfehlen.

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Experience with internal fixation of fractures of the head of the radius

The advantages of internal fixation of fractures, with the possibility of immediate resumption of the function of the fractured bone, are in contrast to the well-known complications described in the literature. These complications and our own unsatisfactory results after surgical treatment of fractures of the head of the radius induced us to carry out a randomized prospective study of primary functional treatment of such fractures without external or internal stabilization. From December 1991 through December 1992, a total of 70 patients were treated according to a strict treatment protocol at the Graz Hospital for Accident Surgery, and CT was used for observation of the healing process. The positive early results, which in 91% of all cases were classified as very good or good, the lack of complications that sometimes follow surgical treatment, the markedly earlier recovery of the patient's working capacity, and the clearly shorter — albeit somewhat more expensive — treatment period required have led us to continue using this method at our hospital and also to recommend its use elsewhere.

     

外固定架治疗桡骨远端爆裂骨折

目的 探讨外固定支架治疗桡骨远端爆裂性骨折的效果．方法 对23例桡骨远端爆裂性骨折病例，ⅣB型13例，ⅣC型10例，采用外固定支架或外固定支架加克氏针治疗．术后随诊并评价疗效。结果 23例随诊6～18个月，优15例，良6例，优良率94．7％。影像学评分，20例优良，3例发生再移位。结论 桡骨远端爆裂骨折采用手法整复外固定架或外固定架加克氏针固定能获得理想的解剖复位和腕关节功能恢复。     

桡骨远端骨折不同治疗方法临床疗效比较

[目的]探讨不同分型桡骨远端骨折的有效治疗方法.[方法]分析236例桡骨远端骨折的治疗,根据AO分型为A、B、C 3型,分别采用闭合手法复位中医小夹板外固定及石膏外固定、切开复位＂T＂形钢板内固定3种固定方法,分别进行骨折的复位评分、功能评分,并比较不同固定方法之间复位评分及功能评分优良率.[结果]236例病人术后均获随访,随访时间6～20个月,平均14.6个月.3组当中A、B型骨折复位评分优良率无显著性差别,功能评分小夹板外固定组及＂T＂形钢板内固定组优良率明显优于石膏外固定组,功能评分小夹板外固定组和＂T＂形钢板内固定组比较优良率无显著性差别;C组当中无论是复位评分还是功能评分,＂T＂形钢板内固定组优良率明显优于其它2组.[结论]对于C型骨折,建议行骨折切开复位内固定;对于A、B型骨折,闭合手法复位小夹板外固定能取得较好的临床疗效.     

桡骨交锁钉固定防止桡神经深支损伤的应用解剖

目的:为桡骨交锁髓内钉固定术避免桡神经深支损伤提供解剖学依据。方法:前臂标本44侧解剖显露桡神经深支,将肱骨外上髁与Lister结节连线和桡骨头关节面,关节面下1.0、1.5、2.0cm,桡神经深支穿入旋后肌平面,桡神经深支跨越桡骨平面等6个面的交点,依次标记为A、B、C、D、E、F6个点。记录AE、AF的长度,测量B、C、D3个定点在屈肘前臂旋前、中立、旋后位与桡神经深支的水平距离。结果:B、C、D3个定点离桡神经深支的距离越来越近;而对于同一定点,其与桡神经深支的距离按旋前、中立、旋后位的顺序越来越远。结论:桡骨交锁髓内钉固定时,宜于屈肘前臂中立位,在肱骨外上髁与Lister结节连线上,距桡骨头关节面约1.5cm的位置,由前臂后外侧向前内侧插入远端交锁螺丝钉较为安全。     

The clinical utility of a decision-aid to facilitate the use of the hand in real-life activities of patients with distal radius fractures: A case study

BackgroundOccupation-based intervention (OBI) in hand therapy has shown superior benefits in patient-reported performance and physical measures; however, only a few studies have used OBI. We developed a decision-aid to promote the use of an injured hand in the real world (Aid for Decision-making in Occupation Choice for hand; ADOC-H)PurposeTo investigate the clinical utility of the ADOC-H (paper version) in patients with distal radius fractures.Study DesignA prospective case series and a clinical survey for occupational therapists.MethodsThis study comprised a prospective patient case series of 8 patients with distal radius fractures, treated using Volar locking plates, and a clinical survey of 4 experienced occupational therapists.ResultsNo patient or therapist complaints or drop-outs were reported. Active range of motion (wrist), Grip strength, and Disabilities of the Arm, Shoulder, and Hand scores improved for all patients. The ADOC-H induced 158 activities using the injured hand, with activities of daily living (69.8%) selected earlier in the treatment period, and instrumental activities of daily living (63.3%) selected later. The feedback and case studies suggested that the ADOC-H was useful for patients who were afraid of using the hand and, interestingly, patients who were able to use their hand without pain or other problems. The clinical survey showed that most therapists found the ADOC-H effective in facilitating real-life use of an injured hand.ConclusionsThe ADOC-H paper version is an useful tool that can be applied to facilitate patients with distal radius fractures to use their injured hands in real-life settings.     

Cast immobilization in bayonet position versus reduction and pin fixation of overriding distal metaphyseal radius fractures in children under ten years of age: a case control study

PurposeCompletely displaced distal radius fractures in children have been traditionally reduced and immobilized with a cast or pin fixed. Cast immobilization leaving the fracture displaced in the bayonet position has been recently suggested as a non-invasive and effective treatment alternative. This is a pilot comparative study between reduction and no reduction.MethodsWe assessed subjective, functional and radiographic outcome after a minimum 2.5-year follow-up in 12 children under ten years of age who had sustained a completely displaced metaphyseal radius fracture, which had been immobilized leaving the fracture in an overriding position (shortening 3 mm to 9 mm). A total of 12 age-matched patients, whose similar fractures were reduced and pin fixed, were chosen for controls. ResultsAt follow-up none of the 24 patients had visible forearm deformity and the maximal angulation in radiographs was 5° Forearm and wrist movement was restored (< 10° of discrepancy) in all 24 patients. Grip strength ratio was normal in all but three surgically treated patients. All patients had returned to their previous activities. One operatively treated boy who was re-operated on reported of pain (visual analogue scale 2).ConclusionThe results of this study do not demonstrate the superiority of reduction and pin fixation over cast immobilization in the bayonet position of closed overriding distal metaphyseal radius fractures in children under ten years with normal neurovascular findings.Level of evidenceIII