Beta-tricalcium phosphate plugs for press-fit fixation in ACL reconstruction--a mechanical analysis in bovine bone

BACKGROUND: The goal of this study was to test fixation properties of microporous pure beta-tricalcium phosphate (TCP) plugs (porosity 40%) for press-fit fixation of the ACL graft using patellar tendons with and without bone blocks. We set out to establish whether it is possible, in this way, to obtain results comparable with those of interference screw fixation of bone-tendon-bone (BTB) grafts in terms of cyclic loading and load-to-failure. METHODS: In a bovine model 30 ACL grafts were fixed in tibial drill holes, divided into three groups: 10 BTB grafts fixed with TCP press-fit plugs (7x25 mm), 10 pure patellar tendon grafts with TCP press-fit plugs (7x25 mm), and 10 BTB grafts with metal interference screws (7x25 mm). All grafts were tested by cyclic loading (50-200 N) and loaded until failure in a tensiometer. RESULTS: Under cyclic loading one interference screw fixation failed. None of the TCP plug fixations failed. After 1500 cycles the displacement of the graft in the drill hole for BTB fixed with screws was 3.6+/-7.8 mm, for BTB/TCP plugs 1.6+/-3.4 mm, and for the pure tendon/TCP grafts 1.4+/-0.4 mm. Regarding cyclic loading the pure tendon/TCP system was significantly superior to BTB (p=0.007). The load-to-failure for the BTB/interference screw group was 908+/-539 N with a stiffness of 94+/-36 N/mm, 936+/-245 N for the BTB/TCP cylinder group with a stiffness of 98+/-12 N/mm, and 673+/-159 N for the pure tendon/TCP group with a stiffness of 117+/-9 N/mm. In terms of pull-out load the BTB/TCP system was significantly better than the pure tendon/TCP group (p=0.011). However, pure tendon/TCP grafts achieved significantly greater stiffness (p=0.002) than the BTB system. CONCLUSION: Press-fit fixation with microporous pure beta-TCP plugs of BTB grafts or patellar tendon grafts without bone blocks for ACL reconstruction leads to primary stability comparable with that achieved by fixation with metal interference screws in case of BTB grafts.     

Biomechanical testing of hybrid hamstring graft tibial fixation in anterior cruciate ligament reconstruction

Hamstring tendon using quadrupled semitendinosus and gracilis autografts is a well-established technique for ACL reconstruction. However, several methods have been used for tibial fixation of the tendon graft. The purpose of this study was to compare the biomechanical characteristics of quadrupled hamstring graft tibial fixation using three different fixation methods. Nine matched pairs (18 specimens) of cadaver tibias were divided into three groups of six specimens. The first group was fixed with only a tapered 30-mm bioabsorbable screw (BIS), the second group was fixed first with a BIS and then the remaining tendon portion was additionally fixed with a titanium cortical screw and spike washer, and the third group was fixed with only a cortical screw and spike washer. A custom-made probe hook was mounted on a load cell (Interface, MFG, Scottsdale, AZ) to measure the ACL tension before and after the final tibial fixation. Group 2 displayed greater mean maximum load at failure than both groups 1 and 3 (p < 0.05). The stiffness of the graft nearly doubled in group 2 compared to groups 1 and 3 (p < 0.05). All specimens failed by slippage and pullout. Biomechanical testing with cadavers showed that a BIS and additional cortical screw and spike washer fixation to the distal hamstring tendon resulted in higher load at failure and stiffness compared to either BIS or cortical screw and spike washer fixation alone.     

No difference in clinical results between femoral transfixation and bio-interference screw fixation in hamstring tendon ACL reconstruction. A preliminary study

Hamstring tendon autograft has become a popular graft choice for anterior cruciate ligament (ACL) reconstruction, but there is no consensus on the ideal technique of fixation. We performed a pilot randomized controlled study to compare the clinical and mechanical outcome of two femoral fixation techniques for anterior cruciate ligament (ACL) reconstruction using hamstrings graft. We recruited 30 patients with a chronic unilateral tear of the anterior cruciate ligament. In all patients, quadrupled hamstring graft was used for ACL reconstruction. In 15 patients, femoral graft fixation was performed using Bio-interference Screws fixation (Arthrex, Inc. Naples USA) (Group 1). In the other 15 patients, femoral graft fixation was performed using BioTransFix femur extra cortical transverse fixation (Arthrex, Inc. Naples USA) (Group 2). In both groups, tibial fixation was achieved with a Delta bio-absorbable interference screw (Arthrex). Both groups were comparable with regard to demographic data, pre-operative activity level, mechanism of injury, interval between the injury and the operation, and pre-operative knee laxity measurements. An independent observer, who was blinded with regard to the involved leg and the type of graft, performed the outcome assessment with the use of a Rolimeter® arthrometer (Aircast), and the International Knee Documentation Committee. At 13 months follow up, all patients except one had functionally normal or nearly normal IKDC objective scores. The mean IKDC subjective score was 83.38 ± 9.4 in Group 1 and 79.92 ± 11.01 in Group 2 (P > .05). The side to side laxity as measured with the Rolimeter® arthrometer was 1.5 mm ± 1 (range 0–3) for Group 1, and 2 mm ± 1 (range 0–3) for Group 2 (P > .05). Femoral Biotransfix fixation and Bio-interference Screws fixation provide comparable mechanical stability and clinical outcome at 13 months follow up. BiotransFix fixation is an effective alternative to other devices. Our preliminary study shows that there is no evidence to prefer femoral transfixation to the more traditional, technically less demanding, and more economical interference screw fixation. A full study requires 368 participants.     

Tibial bone tunnel widening is reduced by polylactate/hydroxyapatite interference screws compared to metal screws after ACL reconstruction with hamstring grafts

Composite interference screws containing calcium phosphate for anterior cruciate ligament graft fixation could improve implant/bone integration and thereby reduced tunnelwidening and graft slippage. The present study investigated the effect of polylactate/hydroxyapatite interference screw (HA/PLLA) screw used for tibial graft fixation on tunnel widening and clinical outcomes compared with a metal interference screw. We hypothesized less tibial tunnelwidening with HA/PLLA screws compared to metal screws. Hundred patients with HA/PLLA screw tibial fixation was compared with 100 patients with metal screw tibial fixation. Tibial tunnel widening was measured on AP and lateral radiographs taken at 12 months follow-up. Clinical outcome was assessed by objective and subjective international Knee Documentation Committee (IKDC) scores, Noyes Sports Activity and Occupational Rating scores and KT-1000 knee laxity measurements. Tibial tunnel widening at the level of the metal screw group was 36% and 38% on AP and lateral radiographs respectively. Tunnel widening was lower in the HA/PLLA group with mean tunnel widening of 30% and 32% (p = 0.012 and 0.018) on AP and lateral radiographs respectively. No differences were found for any of the clinical scores or for anterior knee laxity. The use of a polylactate/hydroxyapatite interference screw resulted in less tibial tunnel widening than a metal screw around the screw but did not affect clinical outcome or objective knee laxity.     

Ligament graft initial fixation strength using biodegradable interference screws

The objective of this study was to evaluate the initial fixation strength of three types of biodegradable interference screws [an Endo Fix, 7 x 25 mm polyglycolic acid, non-self-tapping (Acufex); a biodegradable interference screw, 7 x 23 mm poly-L-lactic acid, self-tapping (Arthrex); a Bioscrew, 7 x 25 mm poly-L-lactic acid, self-tapping (Linvatec)] in comparison to a titanium interference screw (Linvatec, 7 x 25 mm) in anterior cruciate ligament reconstruction using a bone-patellar tendon-bone graft. Porcine lower limbs were used. To control for specimen related bias, bone mineral density of each tibia was measured. All specimens were loaded to failure. Failure mode was determined by visual analysis. The maximum load to failure [mean (SD)] was 785 (87) N (titanium screw), 555 (60) N (Acufex), 592 (211) N (Arthrex), and 844 N (Linvatec). The primary fixation strength of the titanium screw and the Linvatec screw was significantly higher (p < 0.05) than the primary fixation strength of the Arthrex screw and the Acufex screw. There was no difference in bone mineral density between the groups. With respect to primary fixation strength, all biodegradable screws were strong enough to allow accelerated rehabilitation. From this point of view the biodegradable screws may be a reasonable alternative to titanium interference screws.     

Reconstruction of ruptured patellar tendon after total knee arthroplasty: a case report and a description of an alternative fixation method

Patellar tendon rupture after total knee arthroplasty is a rare, but often catastrophic complication. Many different reconstruction techniques of patellar tendon rupture have been described with variable and often discouraging results. A case report with patellar tendon rupture after a total knee arthroplasty is presented. Also, an alternative surgical technique of reconstruction of the patellar tendon using a semitendinosus-gracilis (STG) graft with an interference screw and a staple fixation enabling an immediate mobilization is described.     

Reduced bone tunnel enlargement post hamstring ACL reconstruction with poly-L-lactic acid/hydroxyapatite bioabsorbable screws

Bone tunnel enlargement following anterior cruciate ligament (ACL) reconstruction can complicate revision surgery. This study compared postoperative tibial tunnel widening in patients who underwent arthroscopically assisted, single-incision, four-strand hamstring ACL reconstruction using a poly-L-lactic acid/hydroxyapatite blend (PLLA+HA) bioabsorbable interference screw for tibial fixation, with those in whom a plain poly-L-lactic acid (PLLA) screw was used. Thirty-four patients (13 with PLLA+HA tibial interference screw fixation and 21 with plain PLLA tibial interference screws) underwent a spiral CT scan to assess maximum tibial tunnel cross-sectional area at an average of 28.7 months follow-up. An assessment of tunnel wall sclerosis adjacent to the screw (cortication) was also made. The two groups were well matched for age, sex and graft diameters. Mean tibial tunnel enlargement in patients with PLLA+HA screws was 29.9% at average 30.9 months follow-up compared with 46% in patients with plain PLLA screw at an average 26.5 months follow-up (p=0.03). The tunnel wall adjacent to the screw appeared corticated in only 21% of patients with PLLA+HA screws (p=0.02) compared with 73% of patients with PLLA screws. The blending of HA with PLLA appears to reduce postoperative tunnel widening, and the reduced tunnel wall sclerosis seen postoperatively may indicate improved screw incorporation.     

Contact pressure on ACL hamstring grafts in the bone tunnel with interference screw fixation--dynamic adaptation under load

IntroductionInterference screws used in fixation of anterior cruciate ligament (ACL) hamstring grafts create mechanical hold by forcing the graft into frictional contact with the bone tunnel. We analyzed the resultant graft–tunnel contact pressure using an in vitro model of human cadaver 8 mm hamstring grafts.MethodsContact characteristics were assessed using both pressure sensitive films and a force sensor. Two screw sizes were investigated (8 and 9 mm in an 8 mm Sawbone tunnel), both with and without a bone wedge between graft and screw. Separately, time dependent relaxation of contact force was recorded over a one hour epoch and associated tendon water loss was measured. Pullout testing of 8 mm tendon grafts from 8 mm holes in Sawbone and porcine femora were performed after 1 min and 1 h.ResultsDuring screw insertion, measured peak pressures (> 40 MPa) exceeded the compressive failure stress of metaphyseal bone by more than an order of magnitude. Using a bone wedge between tendon and screw reduced local peak pressure by 85% but produced also inferior average contact pressure. In all approaches, initially achieved graft contact pressure rapidly decreased to approximately 25% within 30 min. Pullout strength was significantly reduced after 1 h in comparison to 1 min in porcine bone as well as Sawbone.ConclusionViscoelastic adaptation of the tendon is severe and critically reduces effective graft–bone contact pressure. Consideration of this newly recognized effect may open new and improved approaches for tendon graft fixation.     

Comparison of Bioabsorbable Suture Anchor Fixation on the Tibial Side for Anterior Cruciate Ligament Reconstruction Using Free Soft Tissue Graft: Experimental Laboratory Study on Porcine Bone

Purpose

The use of graft tissue fixation using bioabsorbable interference screws (BISs) in anterior cruciate ligament (ACL) reconstruction offers various advantages, but limited pullout strength. Therefore, additional tibial fixation is essential for aggressive rehabilitation. We hypothesized that additional graft tissue fixation using bioabsorbable suture anchors (BSA) would provide sufficient pull-out strength.

Materials and Methods

Twenty four fresh frozen porcine distal femur and patellar tendon preparations were used. All specimens were divided into three groups based on additional fixation methods: A, isolated BIS; B, BIS and BSA; and C, BIS and post cortical screw. Tensile testing was carried out under an axial load. Ultimate failure load and ultimate failure load after cyclic loading were recorded.

Results

The ultimate failure loads after load to failure testing were 166.8 N in group A, 536.4 N in group B, and 438 N in group C; meanwhile, the ultimate failure loads after load to failure testing with cyclic loading were 140 N in group A, 466.5 N in group B, and 400 N in group C. Stiffness after load to failure testing was 16.5 N/mm in group A, 33.5 N/mm in group B, and 40 N/mm in group C. An additional BSA fixation resulted in a significantly higher ultimate failure load and stiffness than isolated BIS fixation, similar to post screw fixation.

Conclusion

Additional fixation using a BSA provided sufficient pullout strength for ACL reconstruction. The ultimate failure load of the BSA technique was similar to that of post cortical screws.     

Fixation strength of the interference screw in the femoral tunnel: The effect of screw divergence on the coronal plane

Clinical studies to examine the effect of screw divergence have not been applied to the fixation of hamstring grafts. A few previous reports have addressed the correlations between the loss of pullout strength and divergence on hamstring tendon fixation in biomechanical tests. The purpose of this study was to examine the effect of interference screw divergence on the coronal plane when digital flexor tendons were fixed with an interference screw.Twenty fresh porcine hindlimb specimens were chosen. The grafts were fixed using titanium soft tissue interference screws. The hindlimbs were divided into two groups according to the insertion method of the screw. The screw was placed along the graft parallel to the long axis of the femoral tunnel in 10 specimens (parallel placement group), and the others were placed laterally at a 15° divergent angle from the bone tunnel on the coronal plane (divergence group). The cyclic-loading test was loaded for 1500 cycles.Five specimens failed because of a pull-out of the tendon in divergence group. The number of specimens that failed before the completion of cycles in the divergence group was significantly greater than that in the parallel placement group. Although the residual displacement after 1500 cycles for the divergence group was greater than that for the parallel placement group, no statistically significant difference was found between the groups.This study suggests that the screw placed laterally at a 15° divergent angle on the coronal plane decreases the fixation strength of the digital flexor tendons fixed with an interference screw.     

重建前交叉韧带中Endo-Button和可吸收界面螺钉固定的对比

背景：应用腘绳肌肌腱重建前交叉韧带过程中仍有许多的争议及未知因素需进一步探讨和研究。 目的：比较分析腘绳肌肌腱重建前交叉韧带过程中股骨端分别使用Endo-Button系统和可吸收界面螺钉两种不同固定方式的疗效。 方法：选择45例在关节镜下使用4股自体腘绳肌腱进行前交叉韧带重建患者,实验组25例股骨端使用Endo-Button钢板固定,对照组20例使用可吸收界面螺钉固定。重建后用相同的方法进行康复锻炼。 结果与结论：经过6-21个月的随访,患者膝关节屈伸活动度均达正常范围。Lachman试验中实验组Ⅰ度阳性2例,对照组Ⅰ度阳性3例;轴移试验均阴性。两组重建后膝关节Lysholm评分均较治疗前明显改善,两组间差异无显著性意义。两组随访早期均有较高的骨道扩大发生率,但组间差异无显著性意义;对照组骨道增宽程度强于实验组(P < 0.05)。说明两组早期总体临床效果相近。     

Reconstruction of the anterior cruciate ligament using poly- -lactide interference screws or titanium screws: a comparative study

In the present clinical trial, interference screws, made of poly- -lactic acid and applied in 46 knees, were compared to titanium screws employed in 45 knees for reconstructing the anterior cruciate ligament using bone–patellar tendon–bone. An identical surgical technique was applied to both groups; and neither group disclosed apparent side effects such as synovitis caused by hydrolysis of the PLLA or abnormal biochemical findings in the blood. There was no significant difference in the postoperative outcome between the two groups.     

传统金属拉力钉和高分子可吸收螺钉固定不稳定踝关节骨折的比较

背景：临床治疗下胫腓联合分离型不稳定踝关节骨折可以采用外科内固定方式,内固定过程中可以选择不同的材料,以往大多使用金属拉力钉,但存在断钉等风险。 目的：探讨传统金属拉力钉和高分子可吸收螺钉固定在下胫腓联合分离性不稳定踝关节骨折中的应用效果。 方法：回顾性分析陕西中医药大学附属医院2013年2月至2014年2月收治的63例下胫腓联合分离性不稳定踝关节骨折患者的临床资料,均实施外科内固定治疗,按照所使用材料的不同分为金属拉力钉组32例和可吸收螺钉组31例。于腓骨下段外侧做切口对骨折端予以复位,并利用钢板进行固定,并分别利用传统金属拉力钉和高分子可吸收螺钉进行固定。内固定后随访12个月,观察两组的踝关节功能评分(Baird-Jackson)和临床效果以及不良事件发生情况,并进行比较。 结果与结论：可吸收螺钉组患者平均下地活动时间和内固定后住院天数均显著少于金属拉力钉组(P < 0.05)。两组踝关节功能评分(Baird-Jackson)较固定前均上升,但差异无显著性意义(P > 0.05)。可吸收螺钉组治疗优良率显著高于金属拉力钉组(P < 0.05)。内固定后随访12个月,金属拉力钉组有1例患者出现螺钉断裂,可吸收螺钉组未出现任何不良事件,2组患者均未出现切口感染等情况。结果证实,利用高分子可吸收螺钉固定治疗下胫腓联合分离性不稳定踝关节骨折可以获得较之传统金属拉力钉更好的应用效果。  中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

Patellar tendon length--the factor in patellar instability?

Patellar tendon length has been compared in 42 knees with a history of patellar dislocation, and 51 control knees. A lateral X-ray and a magnetic resonance image (MRI) were taken of each knee. The mean radiological patellar tendon length was 46 mm in the controls and 53 mm in the dislocation group. From MRI images, the mean was 44 mm in controls and 52 mm in the dislocation group. This means that the patellar tendon is significantly (P<0.0001) longer in patients with a history of patellar dislocation on both MRI and X-ray. There is no significant difference (P=0.52) between X-ray and MRI measurements of tendon length. The distance between the tibial plateau and the point of tendon insertion was also measured and found to be 28 and 29 mm in the control and dislocation groups, respectively. There is no significant difference between these two measures (P=0.19). In conclusion, patella alta is caused by a long patellar tendon rather than a low insertion into the tibia. Measuring the length of the patellar tendon using MRI is more specific and more sensitive than the Caton-Deschamps index for patellar instability.     

经皮空心加压螺钉与切开复位内固定修复单纯内踝骨折：关节功能恢复比较

背景：踝关节是人体最重要的关节之一,其中内踝骨折十分多见,对该类骨折的修复方式有多种,常用也是较为传统的为切开复位内固定,随着骨折修复的理念转变,目前闭合复位经皮空心钉固定日趋流行,然而两种方式的疗效对比仍需大量临床资料分析。 目的：对比切开复位内固定与经皮空心加压螺钉置入内固定修复内踝骨折的关节功能恢复情况。 方法：纳入广东省信宜市人民医院骨科2009年3月至2013年3月收治的单纯内踝骨折患者63例,根据修复方案分为两组,切开复位内固定组29例,经皮空心加压螺钉内固定组34例。分别于入院时、修复后3个月按照Kofoed评分标准进行患者踝关节功能评定。 结果与结论：患者随访3-12个月。切开复位内固定组29例中27例切口甲级愈合,2例切口乙级愈合;骨折解剖复位29例,复位不良0例。经皮空心加压螺钉内固定组34例中切口均甲级愈合,解剖复位均固定良好。所有患者均骨性愈合,无感染等并发症。按照Kofoed评分,3个月随访时,切开复位内固定组踝关节评分满意率为97%,经皮空心加压螺钉内固定组满意率为100%。提示切开复位内固定与经皮空心加压螺钉置入内固定修复内踝骨折均有肯定的疗效,但经皮空心加压螺钉置入内固定创伤小,可减少感染率,有利于早期踝关节功能恢复锻炼。     

前交叉韧带重建中可吸收螺钉与金属螺钉两种固定方式比较的系统评价

背景：金属螺钉固定前交叉韧带止点被认为是该手术的金标准,随着可吸收螺钉的应用,固定止点时可吸收螺钉是否优于金属螺钉还有争议。 目的：系统评价可吸收螺钉与金属螺钉在前交叉韧带重建中的作用。 方法：检索PubMed,Ovid Medline,Cochrane图书馆,Embase,中国知网(CNKI),中国生物医学文献数据库(CBM),手术检索相关杂志,搜集关于可吸螺钉与金属螺钉在前交叉韧带重建中比较的临床研究。按Cochrane5.0系统评价方法进行方法学质量评价,并使用RevMan5.0.23软件进行Meta分析。使用GRADE评价证据的质量。 结果与结论：共纳入12个研究,1 032例膝关节。Meta分析结果显示：KT-1000/2000测量结果,Lachman试验,轴移试验,IKDC评分,Lysholm评分,术后感染等两组相比差异无显著性意义。在可吸收螺钉组,骨隧道扩大较明显,膝关节积液较为常见。GRADE结果：6个低质量的证据,2个极低质量证据,4个中等质量的证据。使用可吸收螺钉膝获得与金属螺钉等同的临床,但由于纳入的文献质量较低及论证强度不高,随访时限较短。故需要大样本,高质量,长期随访的研究来进一步论证。     

钢板螺钉结合斯氏针内固定修复粉碎性跟骨关节内伴后上方骨折

背景：目前跟骨关节内粉碎性骨折的治疗方案一般选择钢板螺钉内固定,但对于伴有跟骨后上方骨折的病例,往往因为跟腱牵拉及钢板螺钉内固定的薄弱导致骨折复位困难或者复位难以保持。 目的：探讨切开复位钢板螺钉结合斯氏针置入内固定在粉碎性跟骨关节内移位骨折伴后上方骨折中的疗效。 方法：选取2009年12月至2013年12月上海中冶医院骨科收治的粉碎性跟骨关节内骨折伴跟骨后上方骨折患者40例,随机分为2组。对照组予切开复位钢板螺钉内固定,试验组予切开复位钢板螺钉结合斯氏针内固定。分别于术前、术后4周测量患者GISSANE角、BOHLER角,末次随访时进行MARYLAND足部评分,并进行组内及组间比较。 结果与结论：所有患者均获随访,时间9-23个月。两组患者术后4周BOHLER角、GISSANE角均显著大于术前(P < 0.05);术后4周试验组BOHLER角、GISSANE角均显著大于对照组(P < 0.05)。末次随访时MARYLAND足部评分试验组平均78分,优良率为80%;对照组平均67分,优良率为73%,试验组优良率显著高于对照组(P < 0.05)。提示钢板螺钉内固定辅助斯氏针置入固定修复粉碎性跟骨骨折伴有跟骨后上方骨折,可较单纯钢板螺钉置入内固定取得更为满意的关节内骨折及后上方骨折复位,固定牢靠,可早期功能锻炼,术后患肢功能恢复较单纯钢板螺钉内固定较好。中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程全文链接：     

Revision anterior cruciate ligament reconstruction using autografts with a polyester fixation device

Twenty-nine patients who had undergone anterior cruciate ligament (ACL) revision were evaluated retrospectively between 1992 and 2000. A similar surgical technique was used in all cases. Twenty-six patients underwent revision following failed primary and revision surgery with the ABC scaffold ligament. There were 2 failed primary semitendinosus/gracilis (STG) autografts and one failed bone patella tendon bone (BPTB) autograft. Autologous hamstring tendons (STG) were used in 26 knees, quadriceps tendon in 2 and BPTB autograft in 1 knee. The Mark I Soffix soft tissue fixation device was used in 16 patients and 13 patients underwent reconstruction with the Mark II BH (Button Hole ) Soffix. Follow up evaluation included clinical examination, KT 2000 arthrometric side to side difference (SSD) assessment, Lysholm, Tegner and IKDC scoring. The average follow up time was 50±22 months. The overall SSD was 1.66±1.5 mm, a mean Lysholm score of 87.2±12.5 was obtained and 22 patients had an IKDC score of nearly normal (B). In the Mark II (BH Soffix) group knees were significantly tighter than in the Mark I Soffix group (P<0.05) with a mean SSD of 1.23±1.3 and 2.0±1.6 mm, respectively. However there were no significant differences in the other measured parameters between the two fixation devices. Multiply re-operated knees tended to have lower IKDC and Lysholm scores (not statistically significant). We concluded that the technique reported in this study can restore stability to the knee following failed primary or revision ACL reconstruction and the results in the non-multiply operated knees are comparable to primary reconstruction.     

关节镜下横杆悬挂法重建前交叉韧带

背景：固定移植腱的方法多种多样,每种系统各有其优势,对于用何种方法固定移植的肌腱,目前国际上仍没有一个统一的标准。 目的：观察关节镜下横杆悬挂固定法固定自体腘绳肌腱重建膝关节前交叉韧带的临床疗效。            方法：选择2008-09/2010-01于安徽医科大学第一附属医院骨二科行膝关节前交叉韧带重建的患者20例。所有患者均应用股骨端横杆悬挂固定和胫骨端界面螺钉组成前交叉韧带固定系统行自体腘绳肌腱前交叉韧带单束重建。重建后随访6~16个月(平均10个月),评估患者的关节活动度、稳定性等指标。 结果与结论：随访期间,无严重并发症发生,重建后膝关节活动度均正常。所有患者术前Lysholm膝关节评分为(60.20±11.54)分,重建后6个月为(92.95±3.55)分,较术前明显提高(P < 0.05)。截至重建后6个月,IKDC评分18例正常,其余2例接近正常。说明关节镜下应用自体腘绳肌腱横杆悬挂固定法重建前交叉韧带是一种疗效确切的固定方法。     

Arthroscopic-assisted reduction and stabilization of transverse fractures of the patella

Most patellar fractures are transverse involving the central third. Open reduction and stabilization of transverse patellar fractures is indicated if there is more than 2-3 mm of fragment separation and/or articular incongruity. Arthroscopic-assisted reduction and stabilization of displaced fractures of the patella had been reported as an alternative to open technique. The aim of this study was to report the results of arthroscopic-assisted reduction and fixation of displaced transverse fractures of the patella. Fourteen patients with 14 displaced transverse fractures of the patella were included in this prospective study. Patients were treated by arthroscopic-assisted closed reduction of the fracture with percutaneous screw fixation. Patients were followed up for a mean period of 26 months. All patients were males with an average age of 34 years. All fractures united in a mean period of 7 weeks. Twelve patients regained full knee range of motion and two patients had 10 degrees loss of full flexion. All patients regained full knee extension. Thigh muscle wasting was observed in nine patients with a mean value of 0.8 cm. The mean final Lysholm score was 93. Arthroscopic-assisted reduction and percutaneous screw fixation is an appropriate technique for displaced transverse patellar fractures without major separation or comminution. It offers good functional outcome with minimal complications.