可吸收螺钉在踝关节骨折中的应用

目的 探讨可吸收螺钉治疗踝关节骨折的疗效. 方法 2004年6月至2010年12月采用可吸收螺钉治疗16例踝关节骨折患者,男9例,女7例;年龄21～62岁,平均35岁;其中三踝骨折4例(AO分型:B型2例,C型2例),内外踝骨折8例(AO分型均为B型),单纯内踝骨折2例,单纯外踝骨折2例(1例为AO分型A型,另1例为外踝Maisonneuve骨折合并下胫腓联合和内侧三角韧带损伤).所有涉及外踝的骨折患者只有AO分型A型骨折采用2枚2.7 mm可吸收螺钉或1枚2.7mm可吸收螺钉辅助1枚1.5 mm可吸收棒固定,其余均采用接骨板螺钉固定.内踝骨折采用2～3枚3.5mm或4.0mm可吸收螺钉固定.1例下胫腓联合损伤采用2枚4.5 mm可吸收螺钉贯穿下胫腓固定.后踝骨折采用l～2枚4.0mm或4.5 mm可吸收螺钉从前向后固定.结果 16例患者术后获1.5～4.0年(平均28个月)随访.骨折愈合时间平均为3.0个月,无骨折延迟愈合及骨折不愈合,未出现伤口并发症.按美国足踝外科协会踝与后足功能标准评分评定疗效:优14例,良2例. 结论 可吸收螺钉内固定治疗踝关节骨折疗效好,无需行二次内固定取出手术,但要慎重选择骨折类型.     

可吸收螺钉治疗不同类型的内踝骨折

目的比较运用生物可吸收螺钉治疗旋前外旋型(PER)、旋前外展型(PAB)Ⅰ～Ⅱ型踝关节骨折效果。 方法回顾性分析青岛市西海岸新区中心医院于2015年2月至2017年2月2年内收治的PER、PABⅠ～Ⅱ型踝关节骨折患者。纳入标准：单侧骨折,年龄18～55岁;排除标准：三角韧带断裂或下胫腓前韧带撕脱性骨折,开放性骨折,既往患侧下肢骨折,无法遵嘱功能锻炼。共纳入93例研究对象,PER组39人,PAB组54人。用Mann-Whitney U法比较2组患者术后3个月踝关节的背屈、跖屈角度变化,及踝关节内翻应力位下X线片前后位的踝穴宽度变化。用t检验比较2组患者的踝关节功能美国足踝外科协会评分(AOFAS)。并记录异物反应发生情况。 结果术后3个月,PAB组的踝关节的背屈(Z＝－3.418,P<0.05)、跖屈(Z＝－2.476,P<0.05)角度变化均小于PER组,PAB组的踝关节背屈、跖屈活动恢复较佳。2组患者的踝穴宽度变化差异无统计学意义(Z＝－0.296,P>0.05)。术后3个月,PER组踝关节AOFAS功能评分为(84±5)分、PAB组踝关节AOFAS功能评分为(83±5)分,差异无统计学意义(t＝1.250,P>0.05),2组患者术后3个月的踝关节功能恢复情况基本一致。PER组有2例(5.1%)、PAB组有1例(1.9%)患者出现轻度异物反应。所有观察对象均未发生断钉。 结论运用可吸收螺钉治疗Lauge-Hansen踝关节PER、PABⅠ和Ⅱ型骨折效果确切,PAB患者比PER患者的踝关节背屈、跖屈改善较佳。     

Bioabsorbable interference screws. Histological investigation 4.5 years after operation

Summary The use of degradable implants in recent years has brought not only good results. Foreign body reactions to implantation of degradable polymers clearly curtailed the initial expectations. Bioabsorbable polymers have been used for sutures, vascular clips, and fixation implants for both intra-articular fractures and malleolar fractures. In the literature these implants are controversial. Potential benefits remain for the use of this material for interference screws if the problems of inflammation are minimal and the fixation properties are sufficient. There is no need for a second operation for removal. In one patient, 4.5 years after to implantation of an degradable interference screw (Copolymer 85/15 D,L lactide glycolide; Biologically Quiet, Instrument Makar, Inc. Mount Hope, MI 48864, USA) we took an biopsy and made histological examinations. No foreign body reaction or inflammation signs could be detected.      

Bioabsorbable interference screws for graft fixation in anterior cruciate ligament reconstruction.

The central one third of the patellar tendon autograft is popular because the bone-tendon-bone (BTB) construct provides several graft fixation options, robust graft incorporation, and a mechanically sufficient substitute. Interference screw fixation is one method used to secure the graft. Bioabsorbable interference screws may offer advantages over metal interference screws. Bioabsorbable screws are made from poly L-lactic acid (PLLA) and are absorbed by the body. This prospective, randomized study compared the safety and efficacy of the PLLA screw with that of the metal cannulated interference screw for anterior cruciate ligament reconstruction. There were 204 patients randomly assigned to the Bioscrew (Linvatec, Largo, FL) (n = 103) or the metal interference screw (n = 101) groups at four sites. The mean age was 30 years. There were 66 women and 138 men. Mean follow-up was 30 months for Bioscrews and 28 months for metal screws; the average follow-up interval was 2.4 years. The Lysholm mean scores at 4 years for the 32 patients seen at this interval were 95.0 and 97.2 for the Bioscrew and metal screw group, respectively. Ligament laxity comparisons made with an instrumented arthrometer at manual maximum force resulted in side-to-side mean score differences of B = 1.8mm and M = 1.6mm. The Tegner activity level score means were B = 6.1 and M = 5.8. Other variables examined included pain, thigh size, meniscal tests, Lachman's test, range of motion, anterior drawer, pivot shift, patellofemoral crepitus and tenderness, and joint effusion. None of these variables showed a statistically significant difference between groups. No radiographic evidence of osteolytic change or bone resorption around the Bioscrews was observed. There were no complications related to loss of fixation, toxicity, allergenicity, or other evidence of osteolytic or inflammatory reaction. In every assessment between groups there was no difference found. There were 12 PLLA screws that broke during insertion without any adverse effects. The PLLA headless cannulated interference fit screws produce equal results to similarly designed metal screws.     

Bioabsorbable vs. titanium screws for first tarsometatarsal joint arthrodesis: An in-vitro study

BackgroundThe TMT-1 joint arthrodesis is a common repair for severe hallux valgus. Two crossing interfragmental screws, usually titanium or steel, and a locking plate or a plate with a compression screw are the most common fixation methods for first TMT joint arthrodesis. The qualities of an ideal fixation material include adequate strength and rigidity, biocompatibility, lack of interference with bone healing, lack of visibility and palpability, and a low risk of surgical removal. We sought to determine whether bioabsorbable cannulated screws would perform as well as titanium screws in anatomical models.MethodsIdentical anatomical TMT-1 arthrodesis was created with a saw by making a straight cut in 30 anatomical models (Sawbone®). The bioabsorbable and titanium screws were placed one at a time in exactly the same location in each model according to careful measurements. All 30 models were analyzed with a material testing machine (MTS Insight 30, Eden Prairie, USA). Each model was oriented 15° to the platform to simulate its position to the ground during mid-stance.ResultsIn the single-cycle load-to-failure test, the mean yield load was 61.4 N ± 5.7 N (range, 50.1 N–70.3 N) in the bioabsorbable screw group and 81.2 N ± 12 N (range, 61.7 N–113.4 N) in the titanium screw group (P < .001). The respective values for the stiffness of the fixation were 8.1 N/mm ± 0.8 N/mm (range, 6.7 N/mm to 9.1 N/mm) and 9.7 N/mm ± 1.8 N/mm (range, 6.9 N/mm to 12.6 N/mm) for the bioabsorbable and titanium groups (P = .004). The mean maximum failure loads in the bioabsorbable group were 85.1 N ± 8.5 N (range, 67.1 N–97.2 N) and in the titanium group 120.6 N ± 13.2 N (range, 96.7 N–136.7 N), respectively (P < .001). Analysis of the failure models shows bioabsorbable fixation failures caused by bending occur more often than in the titanium group.ConclusionIn biomechanical testing, titanium screws were stronger than bioabsorbable screws in the TMT-1 arthrodesis model tested, although bioabsorbable cannulated screws may be an alternative to titanium screws in the fixation Lapidus procedure.     

Bioabsorbable implants

Absorbable implants have become the hottest implant material, overtaking titanium as the future. Absorbable devices have moved beyond orthopedics and maxillofacial surgery to spine, vascular, plastics and general surgery. This chapter outlines the experiences of many specialties.     

Bioabsorbable osteofixation devices

There is continued interest in the development of new biomaterials. The application of new implantable biomaterials requires intense research and thorough evaluation. Much time and effort has been required to overcome the risks and problems associated with the bioabsorbable devices. For surgical bone fixation, these materials were investigated since the 1960's. Different polymer properties were explored to ensure adequate strength and biocompatibility. High-molecular-weight bioabsorbable polymers were initially used, followed by addition of reinforcement materials. The most recent materials are self-reinforced, small yet strong devices. The newer generations contain bioactive substances such as antibiotics and growth factors. Bioabsorbable materials are constantly changing as we try to adopt the principles of tissue engineering. Surgeons are using new techniques to exploit these polymers and their bioabsorbable properties. It is hoped that this multidisciplinary approach of surgery and research will continue to help the further evolution of biomaterial science.     

Bioabsorbable interbody spacers

Bioabsorbable polymers have been used in surgery for more than four decades. With increased reliability and decreased incidence of complications, their application has become widespread. Although their role in spinal surgery continues to evolve, the theoretic biomechanical and biologic advantages over contemporary metallic and composite implant materials make bioabsorbable interbody spacers an attractive alternative. The lack of artifact on postoperative imaging studies and the ability to load share across fusion sites in a time-dependent manner can lead to more accurate fusion assessment and increased fusion rates. The preliminary data from small, short-term studies are promising. However, larger studies with long-term follow-up are lacking. The theoretic advantages of bioabsorbable materials must be tempered by the lack of long-term clinical evidence of their benefit. Until the results of more studies in human spinal applications become available, the precise indications for the use of bioabsorbable interbody spacers will continue to evolve.     

Bioabsorbable materials in orthopaedics

The applications of bioabsorbable implants in orthopaedic surgery have mainly been mandated from the need to eliminate implant removal operations. Although they have not gained widespread popularity among orthopaedic surgeons, they still represent an area of evolution. Considerable effort has been put into developing new bioabsorbable materials with fewer adverse effects. In this article an extensive review of the literature is presented emphasising on basic science and clinical applications of these materials. A review of the types of implants, the materials used, their biochemical properties, their adverse effects and some of the potential future applications is presented.     

Bioabsorbable rods in Salter's osteotomy

Salter's innominate osteotomy is a commonly used procedure in the treatment of developmental dysplasia of the hip. The graft is usually fixed with two K-wires that are removed surgically 6 weeks later. The use of bioabsorbable rods to fix the graft saves patients further surgery for removal of wires and ensures a better scar. This paper reports for the first time the successful use of bioabsorbable self-reinforced polyglycolic acid rods for fixing the graft of Salter's innominate osteotomy in the treatment of developmental dysplasia of the hip, and describes the suggested operative technique for their use.     

Bioabsorbable interference screws for bone-patellar tendon-bone anterior cruciate ligament reconstruction: clinical and computerized tomography results of four different models. A prospective study

Abstract We investigated the effectiveness of four bioabsorbable interference screws for bone block fixation in ACL reconstruction, and assessed their complete absorption and graft integration. We performed a prospective clinical evaluation with the IKDC form and computed tomography (CT) scans 3, 6, 9, 12, 18 and 24 months after arthroscopic ACL reconstruction with the bonepatellar tendon-bone (BPTB) technique. A total of 20 patients was divided into five groups according to the type of screw used for the femoral fixation (half-tunnel technique): group A, poly L-lactic acid; group B, polyglyconate copolymer; group C, lactic acid and glycolic acid copolymer; group D, polylactic acid; and group E (control), titanium. Proximal bone graft integration was always achieved within 6 and 12 months. Cystic bone absorption was observed in two group A patients. Ten screws were absorbed (9 completely; 1 partially): 1 completely and 1 partially in group A at 9 and 24 months; 4 in Group B between 12 and 18 months; 4 in Group C (2 each at 12 and 24 months); and none in Group D. The IKDC ratings were: group A, four patients with A; group B, 2 with A, 1 with B and 1 with C; group C, 2 with A, 2 with B; group D, 4 with A. Effusion that resolved within 6 months was noted in 2 group A and 2 group C patients. One patient in group B had a traumatic re-rupture of the graft; the screw was not found when he was re-operated at 18 months. The four bioabsorbable interference screws provided safe and effective bone block fixation during ACL reconstruction. Their 93.75% excellent and good overall IKDC results were in line with those achieved with metal interference screws. The fact that none of the group D screws (polylactic acid) were absorbed at 2 years indicates that absorption of polylactic acid is a slow biological process. This is also suggested by the absence of effusion in this group.     

Bioabsorbable fixation in foot and ankle

Bioabsorbable implants are playing an increasing role in the surgical management of foot and ankle pathologies. Current technology allows implants to have acceptably comparable strength and pull-out characteristics to metallic implants. The advantages include elimination of secondary surgeries, biodegradability of implants placed across mobile articular surfaces, as well as acceptable biocompatibility and resorption properties to limit historical complication concerns.     

Bioabsorbable screw fixation in coracoclavicular ligament reconstruction

The purpose of this study is to evaluate the biomechanical properties of stainless steel and bioabsorbable screw fixation of the clavicle to the base of the coracoid. Seven matched pairs of fresh frozen shoulders were prepared by removing all soft tissue except the acromioclavicular and coracoclavicular ligament complexes. The shoulders were randomly selected and fixed with 4.5-mm stainless steel (SS) screws, while contralateral shoulders were fixed with 4.5-mm poly L-lactic acid polymer (PLLA) screws. Pullout strength, stiffness, and elongation to failure were measured using an Instron Mechanical Tester (Model 4202). The average pullout strength of 720.6 +/- 244.9 N of the metal screws was not statistically different (p = 0.089) from that of the biodegradable screws of 580.4 +/- 188.6 N. The pullout strengths exerted by both these screws exceeded the reported strength (500 N) of the intact coracoclavicular complex indicating adequate initial pullout strength for coracoclavicular fixation.     

Bioabsorbable thread for tight tying of bones

The purpose of this research was to develop a bioabsorbable thread for tight fixation of fractured bones and to examine its mechanical performance in an in-vitro simulation study. The thread is a blend of bioabsorbable poly(L-lactic acid); (PLLA) and poly(ε-caprolactone); (PCL) fibers and can be tightly connected by fusion welding of the PCL fibers. The tying strength of the PLLA-PCL blend thread was 39.7 N, which was comparable to that of stainless steel wire. A testing machine was fabricated to measure the fatigue strength of the tying by simulating bone fixation. The results showed that metal wires always failed because of breakage within 25 000 loading cycles, whereas the blend threads did not fail until 50 000 loading cycles. The looseness of tying for simulated bone fixation by the blend thread was within 1mm even after 50 000 loading cycles. In-vivo testing using rats revealed that the blend thread did not cause any severe inflammatory reaction. Received for publication on March 15, 1999; accepted on July 7, 1999