New classification of the distal attachment of the fibularis brevis — Anatomical variations and potential clinical implications

BackgroundAlthough the lateral compartment of the leg is characterized by a high degree of morphological variation, very little information exists on the morphological variability of the fibularis brevis muscle (FBM) and fibularis digiti quinti (FDQ). The main aim of the study was to characterize the morphology of the FBM tendon and its accessory bands, to classify them and to determine the incidence of FDQ. The work attempts to determine the relationship between the types of the insertion of the FBM tendon and the occurrence of FDQ.MethodsClassical anatomical dissection was performed on 102 lower limbs fixed in 10% formalin solution. The morphology of the insertion of the FBM and of the FDQ was evaluated.ResultsThe FBM was present in all specimens. Two types of insertion were observed, the most common being Type I (70.6%): a single distal attachment in which the tendon inserts into the tuberosity at the base of the fifth metatarsal bone. The second most common was Type II (29.4%); this group was divided into three subtypes (A–C). The FDQ was present in 17.7% of specimens and always with Type I FBM.ConclusionBoth the FBM tendon and FDQ present significant morphological variation. Two main types of the FBM tendon determine the presence of the FDQ.Level of evidenceII Basic Science Research.     

Posterolateral plate fixation with Pantalarlock® is more stable than nail fixation in tibiotalocalcaneal arthrodesis in a biomechanical cadaver study

BackgroundDespite the promising results of ankle joint arthroplasty, the tibiotalocalcaneal (TTC) arthrodesis remains an established procedure in treatment of combined pathology of the ankle and subtalar joint. Despite the promising results in biomechanical investigations, nonunion rates of up to 24% are described in recent studies. The objective of this work was a comparative study of the biomechanical properties of the posterolateral plate fixation with retrograde intramedullary nail fixation.MethodsTwenty four fresh-frozen human lower leg specimens (12 pairs) were used for the comparative biomechanical testing. Every specimen was preconditioned with 100 N over 200 cycles. After every 250 cycles the force was increased by 50 N from 200 to 600 N. This was followed by cyclic loading in dorsi-/plantiflexion with 800 N for 3000 cycles. All specimens were subjected to bone densitometry (DXA) and computed tomography.ResultsSignificantly higher number of spacimens with nails (4) failed during the cycling testing in dorsi-/plantarflexion and futher two during the cyclic testing with 800 N. Two specimens with plates failed during the cyclic testing with 800 N. Statistical analysis showed that the specimens with the plate were significantly more stable in each test direction. The Pearson correlation demonstrated for the specimens with plate a linear relationship between the stiffness and the determined bone density.ConclusionsThe results demonstrate a significantly superior stiffness of the Pantalarlock®-plate in all testing directions compared with the HAN nail. Probably the position of the plate on the tension side of the joint and the combination of locking and lag screws provide the higher stiffness of the plate system. The correlation of the stiffness with bone density leads to more predictable results of the plate arthrodesis. We hope for a reduction of the pseudarthrosis rate and shorten the postoperative treatment phase. The authors expect advantages in the treatment of high risk patients with severe deformity of the ankle, bone defects, neuropathic deformity, poor bone quality and osteoporosis.     

侧方应力摄片测量和膝关节MRI诊断内侧副韧带损伤的临床研究

目的:研究双膝外翻应力位摄片对膝关节内侧副韧带损伤的诊断意义。方法:自2008年1月至2011年6月收治膝关节内侧副韧带损伤46例,31例行手术治疗,15例保守治疗,其中1例保守治疗3个月无效后手术。其中男32例,女14例;年龄28～72岁,平均(49.46±22.54)岁;左膝22例,右膝24例。常规行损伤侧、正常侧的应力位下和非应力位下X线摄片和MRI检查,对于内侧间隙明显增宽和MRI表现有深层断裂及后交叉韧带损伤的择期行切开内侧副韧带行缝合或重建术。以胫骨平台内侧髁和外侧髁作一条连线记为A线,将此线向上平移至股骨内侧髁最内缘记为B线,然后测量这2条线的垂直距离记为C。间隙差比值(R)计算方法为(患侧应力下间隙-患侧无应力下间隙)/(健侧应力下间隙-健侧无应力下间隙)。总结R值区间与术中所见韧带损伤种类的关系。结果:46例中17例有韧带浅层撕裂,21例深层断裂,8例合并有后关节囊或后交叉韧带断裂,当比值介于1.51～5.24时,内侧副韧带损伤表现为浅层撕裂的有15例,实际损伤为17例,诊断正确率为88.24%;当比值介于5.28～13.85时,表现为深层断裂的有19例,实际损伤为21例,诊断正确率为90.48%;当比值介于15.61～26.25时,表现为合并后关节囊或交叉韧带断裂的有7例,实际损伤为8例,诊断正确率为87.50%。结论:以膝关节受伤侧关节间隙差值与正常侧差值的比值作为衡量标准,可以提供膝关节内侧副韧带损伤的量化分级。