No Midterm Benefit from Low Intensity Pulsed Ultrasound after Chevron Osteotomy for Hallux Valgus

Chevron osteotomy is a widely accepted method for correction of symptomatic hallux valgus deformity. Full weight bearing in regular shoes is not recommended before 6 weeks after surgery. Low intensity pulsed ultrasound is known to stimulate bone formation leading to more stable callus and faster bony fusion. We performed a randomized, placebo-controlled, double-blinded study on 44 participants (52 feet) who underwent chevron osteotomy to evaluate the influence of daily transcutaneous low intensity pulsed ultrasound (LIPUS) treatment at the site of osteotomy. Follow-up at 6 weeks and 1 year included plain dorsoplantar radiographs, hallux-metatarsophalangeal-interphalangeal scale and a questionnaire on patient satisfaction. There was no statistical difference in any pre- or postoperative clinical features, patient satisfaction or radiographic measurements (hallux valgus angle, intermetatarsal angle, sesamoid index and metatarsal index) except for the first distal metatarsal articular angle (DMAA). The DMAA showed statistically significant (p = 0.046) relapse in the placebo group upon comparison of intraoperative radiographs after correction and fixation (5.2 degrees) and at the 6-week follow-up (10.6 degrees). Despite potential impact of LIPUS on bone formation, we found no evidence of an influence on outcome 6 weeks and 1 year after chevron osteotomy for correction of hallux valgus deformity. (E-mail: max_zacherl@hotmail.com)     

第一跖骨基底部楔形截骨联合改良Mcbride手术治疗中重度拇外翻

目的探讨第一跖骨基底部楔形截骨联合改良Mcbride手术治疗中重度拇外翻的疗效。方法以江苏省人民医院2010年1月至2017年8月收治的80例拇外翻患者为对象,共131足。其中中重度拇外翻68足,对此68足拇外翻患者均予以第一跖骨基底部楔形截骨联合改良Mcbride手术治疗,分析疗效。结果随访时间均为术后1年,拇外翻角、第一与二跖骨夹角、第一跖骨远端关节面角均小于术前,差异有统计学意义(P均<0. 01);并发症发生率为3. 33%(2/68)。术后1年VAS疼痛评分(1. 68±0. 12)分,较术前的(6. 65±0. 31)分降低(P <0. 01),AOFAS评分(89. 54±2. 36)分,较术前的(42. 38±3. 42)分升高(P <0. 01)。结论第一跖骨基底部楔形截骨联合改良Mcbride手术治疗中重度拇外翻,可改善患者症状,且并发症少,可有效缓解患者疼痛、促进足部功能康复。     

迷你双螺纹空心钉结合截骨治疗拇外翻

背景：拇外翻畸形矫正方式多样,采用迷你双螺纹空心钉材料结合截骨矫形的方式损伤小,能够满足拇外翻矫形的目的,是临床上新型的微创生物型内固定材料。目的：回顾性分析迷你双螺纹空心钉材料应用于截骨矫形拇外翻治疗中的临床疗效。方法：选择拇外翻畸形患者30例,其中双侧矫形患者8例,单侧矫形患者22例。根据自愿均采用第一跖骨截骨矫形迷你双螺纹空心钉内固定,治疗前后拍摄X射线片测量外翻角、跖间角、籽骨位置,进行AOFAS评分,并计算第一跖骨短缩长度。结果与结论：采用迷你双螺纹空心钉结合截骨矫形治疗后,拇外翻畸形患者的外翻角、跖间角、AOFAS评分及籽骨位置较治疗前明显改善,第一跖骨短缩在矫形可控范围内避免畸形复发及跖骨痛。     

Biomechanical comparison of hallux valgus correction using the proximal chevron osteotomy fixed with a medial locking plate and the Ludloff osteotomy fixed with two screws

BackgroundFor moderate-to-severe hallux valgus deformities with a 1–2 intermetatarsal angle in excess of 15°, a proximal first metatarsal osteotomy is indicated. The ideal osteotomy has yet to be defined, but should inherently limit the incidence of dorsal malunion and allow for early ambulation. The present study evaluates the mechanical integrity of two popular first metatarsal osteotomies.MethodsTen matched pairs of fresh-frozen cadaveric first metatarsals were harvested. In one metatarsal from each pair, a Ludloff osteotomy was created and fixed with two cannulated 3.5 mm screws. In the contralateral first metatarsal, a proximal chevron osteotomy was performed and subsequently fixed with a medially applied locking plate. All specimens were mounted within an Instron 1321 servohydraulic materials testing machine and subjected to a plantar-to-dorsal cantilever bending protocol for 1000 cycles.FindingsTwo of ten Ludloff osteotomies failed prior to completion of 1000 loading cycles by fracture at the distal screw site, whereas six of ten proximal chevrons failed prior to the 1000th cycle. The mode of failure in this group was by cut-out of the plantar-proximal screw. The bending stiffness of the Ludloff osteotomy exceeded that of the proximal chevron at all measurement points between the 1st and 200th load cycles (P < 0.05). After 200 cycles, an inadequate number of plate constructs survived to allow statistical comparison.InterpretationThe results of the present study indicate that the proximal chevron osteotomy fixed with a medially based locking plate exhibits mechanical properties inferior to those of the Ludloff osteotomy under the tested conditions.     

可吸收螺钉在踇外翻第1跖骨远端改良chevron截骨中的应用

背景：第1跖骨远端改良chevron截骨是治疗踇外翻的常用术式,应用可吸收螺钉进行固定的效果尚存争议。目的：评价可吸收钉在踇外翻第1跖骨远端改良chevron截骨中的应用效果。方法：对8例中度踇外翻患者行远端改良chevron截骨,V形截骨后采用1枚2.7mm可吸收螺钉固定,穿前足免负重鞋6～8周。结果与结论：纳入的8例患者均获随访,随访时间28～46个月。患者伤口均一期愈合,踇外翻角改善为15°～21°,平均（17.63±2.07）°;第1,2跖骨间角为7°～9°,平均（8.00±0.76）°;美国足踝外科协会踇趾-跖趾-趾间关节评分由术前的（70.13±7.10）分提高到术后的（92.75±7.30）分（P〈0.05）。说明远端改良chevron截骨后使用可吸收螺钉固定治疗轻中度踇外翻疗效可靠,是一种有效的固定方法。     

Ludloff截骨修复矫治拇外翻的三维力学特点

背景：目前针对Ludloff截骨三维特点的研究甚少,且结论稍有不同,导致不能准确地理解其截骨特点。目的：分析Ludloff截骨技术修复矫治拇外翻的三维力学特点。方法：采用长86.56mm、直径30.65mm的木质圆柱体,进行Ludloff截骨矫治拇外翻的模拟试验,测量并记录数据。结果与结论：圆柱体的长度随矫形程度的增加而逐渐短缩;无论截骨面偏向跖侧、背侧或水平,截骨的结果均导致远端内旋。Ludolff截骨矫治拇外翻的结果是使截骨远端呈内旋,这对改善第一跖趾关节生物力学有积极的作用。对于有明显跖骨痛的患者可采用偏向跖侧15°～20°的截骨面;对于Ⅰ/ⅡIMA（≥30°）的患者,应谨慎使用Ludolff截骨。     

Hallux valgus surgery affects kinematic parameters during gait

BackgroundThe aim of our study was to compare spatiotemporal parameters and lower limb and pelvis kinematics during the walking in patients with hallux valgus before and after surgery and in relation to a control group.MethodsSeventeen females with hallux valgus, who underwent first metatarsal osteotomy, constituted our experimental group. The control group consisted of thirteen females. Kinematic data during walking were obtained using the Vicon MX system.FindingsOur results showed that hallux valgus before surgery affects spatiotemporal parameters and lower limb and pelvis kinematics during walking. Hallux valgus surgery further increased the differences that were present before surgery. Specifically after hallux valgus surgery, the walking speed decreased even more (p = 0.09, η² = 0.19) while step time increased (p = 0.002, η² = 0.44) on both legs. The maximum ankle plantar flexion of the operated leg during toe-off decreased to a greater extend (p = 0.03, η² = 0.26). The asymmetry in the hip and the pelvis movements in the frontal plane (present preoperatively) persisted after surgery.InterpretationHallux valgus is not an isolated problem of the first ray, which could be just surgically addressed by correcting the foot's alignment. It is a long-term progressive malfunction of the foot affecting the entire kinematic chain of the lower extremity.     

Current concepts in the treatment of hallux valgus

Hallux valgus is a common disorder of the forefoot that results from medial deviation of the first metatarsal and lateral deviation and/or rotation of the great toe (hallux) with or without medial soft-tissue enlargement of the first metatarsal head (bunion). It is the most common pathologic condition affecting the great toe. There is a known predilection of hallux valgus and bunions in the female population (female-male ratio =9:1), which is likely due to both biomechanics (joint laxity/instability) and shoe wear demands. There are many different conservative and surgical treatment options for hallux valgus and bunions. The multitude of established procedures and technique modifications in the literature underscores the fact that no single approach universally addresses this common disorder.     

Link动力加压钢支架治疗踇外翻

目的探讨link动力加压钢支架治疗踇外翻的效果及其适应证。方法采用改良chevron截骨术配合使用link动力加压钢支架治疗踇外翻13例,对术后疼痛缓解程度,关节活动和外形改善进行比较。结果 13例手术优良率为100%,术后未出现并发症。结论改良chevron截骨术配合使用link动力加压钢支架治疗踇外翻效果良好。     

Distal ligamentous restraints of the first metatarsal. An in vitro biomechanical study

BACKGROUND: Hypermobility or instability of the first metatarsal is associated with increased hallux valgus deformity and greater risk of recurrence after surgery. The objective of this in vitro study was to determine the ranges of movement, under directional loading, of the normal first metatarsal and the effect of the longitudinal plantar aponeurosis and the transverse tie-bar ligamentous system. METHODS: A model has been developed to quantify the influence of the first intermetatarsal ligament and plantar aponeurosis on movements of the first metatarsal. All muscular structures controlling movements of the first ray in cadaver feet were detached and static ligament structures retained for study. Using a specially designed test system, a static load was applied to the metatarsal to produce flexion, extension, abduction or adduction moments. The first intermetatarsal ligament and the plantar aponeurosis were detached sequentially and a movement map of the first metatarsal in the frontal plane was obtained using the Isotrak II magnetic measuring system. RESULTS: The first intermetatarsal ligament was shown to be an important stabiliser of the first metatarsal in all directions. The plantar aponeurosis was shown to be a secondary stabiliser resisting medial and dorsal rotation of the metatarsal after division of the first intermetatarsal ligament. INTERPRETATION: Recognition of the importance of the plantar aponeurosis and the first intermetatarsal ligament in the normal foot has implications for our understanding of hallux valgus.     

Medial displacement calcaneal osteotomy reduces the excess forces in the medial longitudinal arch of the flat foot.

OBJECTIVE: The hypothesis tested was that the increased load on the medial arch of the flat foot can be reduced through a medial displacement calcaneal osteotomy. DESIGN: A three-dimensional, biomechanical, multisegment model was used in conjunction with experimental data from the literature. BACKGROUND: Biomechanical models have been used to study the plantar fascia, medial arch height, subtalar motion and distribution of forces in the foot. METHODS: Responses of a normal foot, a flat foot and a flat foot with a medial displacement calcaneal osteotomy to an applied load of 683 Newtons were analyzed, and the distribution of support among the metatarsal heads and moment about various joints were computed. RESULTS: Compared to the normal foot, our flat foot model shifts the distribution of support from the lateral to the medial side, decreasing support provided by the fifth metatarsal from 11% to 1% of the total load, increasing support provided by the first metatarsal from 12% to 22% and increasing the moment about the talo-navicular joint from 20 to 28 Newton-meters. A ten millimeter medial displacement calcaneal osteotomy shifts support back toward the lateral side, with 11% provided by the fifth metatarsal and 13% by the first metatarsal. The moment at the talo-navicular joint decreases to eighteen Newton-meters. CONCLUSION: Our analysis indicates that a ten millimeter medial displacement calcaneal osteotomy in a flat foot model decreases the load on the medial arch.     

拇外翻术后拇外翻角和第1-2跖骨间角X射线测量方法评价

背景：拇外翻术后拇外翻角和第1-2跖骨间角的测量关键在于第1跖骨轴线的确定。第1跖骨轴线的不同确定方法,造成了这两个角度测量值的差异,使不同临床研究之间的数据不具有可比性。对于拇外翻术后角度测量,国内外尚未形成公认的标准方法。目的：回顾不同拇外翻术后拇外翻角和第1-2跖骨间角的测量方法的研究进展,为拇外翻的术后测量与评价研究提供参考。方法：由第一作者在2012年2月检索PubMed、中国期刊全文数据库以及万方数据库。其中,英文检索词为：＂hallux valgus＂、＂angles＂、＂radiographic measurements＂。中文检索词为＂拇外翻＂、＂角度＂、＂X射线测量＂。选取29篇文献进行归纳总结。结果与结论：最好的测量方法其标记点必须是易于确定,可重复性好,应尽量避免受到截骨部位及跖骨本身解剖变异的影响。拇外翻术后X射线测量方法目前多用头部中心/基底部中心测量方法。专业化的工具软件测量取代手工测量是未来拇外翻术后X射线测量的发展趋势。     

Three-dimensional analysis of tarsal bone response to axial loading in patients with hallux valgus and normal feet

BackgroundPatients with hallux valgus present a variety of symptoms that may be related to the type of deformity. Weightbearing affects the deformities, and the evaluation of the load response of tarsal bones has been mainly performed using two-dimensional plane radiography. The purpose of this study was to investigate and compare structural changes in the medial foot arch between patients with hallux valgus and normal controls using a computer image analysis technique and weightbearing computed tomography data.MethodsEleven patients with hallux valgus and eleven normal controls were included. Computed tomograms were obtained with and without simulated weightbearing using a compression device. Computed tomography data were transferred into a personal computer, and a three-dimensional bone model was created using image analysis software. The load responses of each tarsal bone in the medial foot arch were measured three-dimensionally and statistically compared between the two groups.FindingsDisplacement of each tarsal bone under two weightbearing conditions was visually observed by creating three-dimensional bone models. At the first metatarsophalangeal joint, the proximal phalanges of the hallux valgus group showed significantly different displacements in multiple directions. Moreover, opposite responses to axial loading were also observed in both translation and rotation between the two groups.InterpretationWeightbearing caused deterioration of the hallux valgus deformity three-dimensionally at the first metatarsophalangeal joint. Information from the computer image analysis was useful for understanding details of the pathology of foot disorders related to the deformities or instability and may contribute to the development of effective conservative and surgical treatments.     

A biomechanical analysis of posterior tibial tendon dysfunction,medial displacement calcaneal osteotomy and flexor digitorum longus transfer in adult acquired flat foot

Background

Biomechanical models have been used to study stress in the metatarsals, subtalar motion, lateral column lengthening and subtalar arthroereisis. Posterior tibial tendon dysfunction has been associated with increased loads in the arch of the acquired flat foot. We examine whether a 10 millimeter (mm) medial displacement calcaneal osteotomy and flexor digitorum longus transfer to the navicular reduces these increased loads in the flat foot.

Methods

The response of a normal foot, a foot with posterior tibial tendon dysfunction, and a flat foot to an applied load of 683 Newton was analyzed using a multi-segment biomechanical model. The distribution of load on the metatarsals, the moment about each joint, the force on each of the plantar ligaments and the muscle forces were computed.

Findings

Posterior tibial tendon dysfunction results in increased load on the medial arch, which may cause the foot to flatten. A 10 mm medial displacement calcaneal osteotomy substantially decreases the load on the first metatarsal and the moment at the talo-navicular joint and increases the load on the fifth metatarsal and the calcaneal-cuboid joint. Adding the flexor digitorum longus transfer to the medial displacement calcaneal osteotomy has only a small effect on the flattened foot.

Interpretation

Our biomechanical analysis illustrates that when the foot becomes flat, the force on the talo-navicular joint increases substantially from its value for the normal foot, and that medial displacement calcaneal osteotomy can reduce this increased force back toward the value occurring in the normal foot. This study provides a biomechanical rationale for medial displacement calcaneal osteotomy treatments for posterior tibial tendon dysfunction.     

Mid-term functional outcome of a total arthroplasty of the first metatarsophalangeal joint

BackgroundArthroplasty of the first metatarsophalangeal joint is an alternative treatment option for end-stage hallux rigidus to the current gold standard of arthrodesis. The aim of this study was to investigate the mid-term functional outcome of an anatomically shaped prosthesis for the first metatarsophalangeal joint using pedobarography.MethodsTen patients (12 affected feet; age at surgery: 62.1 (SD: 7.2) years) were investigated preoperatively and 52 (SD: 3) months postoperatively using pedobarography (EMED, novel GmbH, Munich, Germany). Two patients were excluded at follow-up because their prosthesis was converted to an arthrodesis. Peak force and plantar pressure under the five metatarsal heads and the hallux were analyzed and correlated with the clinical outcome (pain, American Orthopaedic Foot and Ankle Society forefoot score and radiographic maximum first metatarsophalangeal dorsiflexion). Differences between pre- and postoperative data were analyzed using paired t-tests (alpha = 0.05).FindingsPostoperatively, forefoot peak forces under the fourth (+ 40.9%; P = 0.018) and fifth metatarsal (+ 54.9%; P = 0.037) and plantar pressures under the fifth metatarsal (+ 38.7%; P = 0.027) increased significantly, while peak plantar pressures and forces under the hindfoot, medial forefoot and hallux did not change. While maximum passive dorsiflexion was not significantly greater at the 4-year follow-up compared to preoperatively, overall greater passive dorsiflexion was associated with higher first metatarsal peak pressure.InterpretationDespite of patients reporting less pain, the functional results indicate an altered and potentially non-physiological postoperative gait pattern with a lateralization of the load during walking, especially in patients with limited passive dorsiflexion.     

The study of surface electromyography used for the assessment of abductor hallucis muscle activity in patients with hallux valgus

Background: Hallux valgus is a common foot disorder. In patients with hallux valgus, the anatomy and biomechanics of foot is subject to alterations. Objective: The aim of this clinical and neurophysiological study is to compare the activity of abductor hallucis (AbdH) muscle between the group of patients with hallux valgus and control group of healthy people, with the use of surface electromyography. Methods: The study involved 44 feet with diagnosed hallux valgus (research group) and 42 feet without deformation (control group). The X-ray images, measurements of range of motion in the first metatarsophalangeal joint and in hallux interphalangeal joint, and the surface electromyography study recorded from AbdH muscle were performed. Results: Considering the amplitude of motor unit action potential, study participants with hallux valgus demonstrate significantly less activity of AbdH muscle than people without hallux valgus deformity. This activity is not dependent on the severity of valgus, age, or range of motion. Conclusions: It is speculated that the changes of the AbdH function may occur in the period before clinical appearance of hallux valgus deformity, or at the onset of distortion development. Further studies are needed for a comprehensive assessment of AbdH muscle in patients with hallux valgus.     

拇外翻主要病理改变及组织修复方法的选择

拇外翻其病理改变具有多样性的,包括第一跖骨内收、第一,二跖骨问角增大、拇趾外翻角增大、第一跖趾关节近端关节面固定角或远端关节面固定角增大、籽骨移位、软组织平衡的改变等.X射线测量是确定拇外翻病理改变的主要的手段.拇外翻病理改变的多样性使得修复方式具有多样性,主要有软组织修复、截骨修复和关节融合或关节成形等修复方式.拇外翻修复方式的选择应该个体化,根据患者具体的病理改变选择一个或多个修复方式.     

Tension band wire fixation for valgus osteotomies of the proximal femur: a biomechanical study of three configurations of fixation

BACKGROUND: A variety of techniques can be used to achieve stabilization of femoral valgus osteotomies in children, but what is lacking is a versatile fixation system that associates stability and versatility at different ages and for different degrees of deformity. METHODS: Mechanical tests of three configurations used to fix femoral valgus osteotomies, based on the tension band wire principle, were carried out. A 30 degrees wedge valgus osteotomy was performed at the subtrochanteric level in 60 swine femurs and fixed with three different systems. In Group 1, two Kirschner wires (K wire) were introduced from the tip of the greater trochanter to the medial cortex, crossing the osteotomy. A flexible steel wire was anchored to the K wires into holes in the lateral cortex and tightened to form a tension band. The same setup was used in Group 2, but two additional smooth K wires were inserted into the lateral surface of the greater trochanter and driven to the femoral head with the distal extremities bent and tied around the bone shaft. In Group 3, the fixation was similar to that in Group 2, but the ascending K wires were introduced below the osteotomy level, crossing the osteotomy. Mechanical tests in bending-compression and torsion were used to access the stability. FINDINGS: The torsional relative stiffness was 116% greater for Group 3 (0.27 Nm/degree) and no significant difference was found between Group 1 (0.10Nm/degree) and Group 2 (0.12 Nm/degree). The average torque was 103% higher for Group 3 (1.86 Nm). Stiffness in bending-compression was significantly higher in Group 3 (508 x 10(3) N/m) than in Group 1 (211 x 10(3) N/m) and Group 2 (219 x 10(3) N/m). INTERPRETATION: Fixation as used in Group 3 was significantly more stable, both in torsion and bending-compression tests, than the other two techniques.     

Scarf联合Akin截骨治疗中重度拇外翻畸形疗效分析

目的探讨Scarf联合Akin截骨治疗中重度拇外翻畸形临床疗效及手术指证。方法 68例108足中重度拇外翻畸形行Scarf截骨＋Akin截骨治疗,术后采用AOFAS评分联合X线片观察疗效及影像学改变。结果 68例获随访6~12个月;手术切口均一期愈合,截骨处愈合时间12周,无延迟愈合或不愈合,术后无并发症发生,治疗优良率96%;术后拇外翻角度、第1、2跖骨间角及胫侧籽骨位置（（5.70±1.25）°、（6.20±0.92）°、（2.48±0.51）级）均较术前（（40.20±5.43）°、（18.00±2.00）°、（4.98±0.65）级）明显下降（P〈0.05）,AOFAS评分（（88.30±7.06）分）较术前（（50.80±6.09）分）明显升高（P〈0.05）。结论 Scarf＋Akin截骨手术可技术互补,治疗中重度拇外翻畸形效果良好。     

Biomechanical evaluation of different types of lateral hinge fractures in medial opening wedge high tibial osteotomy

BackgroundLateral hinge fractures are common complications in the medial opening wedge high tibial osteotomy for treatment of knee osteoarthritis. The rehabilitation protocols are decided depending on the remaining stability following these fractures. This study aimed to evaluate the biomechanical properties of different types of lateral hinge fractures in medial opening wedge high tibial osteotomy.MethodsTwenty synthetic tibia models were used as test samples. A 10-mm bone wedge was removed from the medial side of the proximal tibias to create the bone defect. The samples were then divided into 4 groups: (1) intact lateral hinge; (2) Takeuchi type I fractures; (3) type II fractures; and (4) type III fractures. After fixation with a locking plate, the stability parameters including construct stiffness, wedge displacement, and construct strength were tested under compressive forces and compared among the 4 groups.FindingsNo statistical difference was found in the construct stiffness among the 4 groups (P = 0.78). The type III fractures had the largest wedge displacement compared with the other 3 groups. The failure loads on average were significantly reduced in the type III fractures compared with those with intact hinge (P < 0.01) and in type I fractures (P = 0.04). No statistical difference was observed between the type I fractures and the intact hinge in terms of wedge displacement or failure loads.InterpretationThe type III fractures were the most unstable and patients with these fractures should be managed cautiously. Delayed weightbearing and/or additional fixation should be considered.