副舟骨(Accessory Navicular Bone)-双语学习

Definition/Description 定义/描述

Also known as Prehallux, Os Tibiale Externum and Navicular Secundum.

也被称为赘拇，外胫骨和多舟骨。

An accessory navicular bone is a bone of the foot that develops abnormally causing a plantar medial enlargement of the navicular. The accessory navicular bone presents as a sesamoid in the posterior tibial tendon, in articulation with the navicular or as an enlargement of the navicular itself.

副舟骨是一种足部发育异常导致舟骨足底内侧增大的骨。副舟骨表现为胫骨后腱的籽骨、与舟骨相连或舟骨本身的增大。

The Geist classification divides these into three types: Geist将其分为三类:

Type I: is a sesamoid bone in the posterior tibialis tendon. There is a small gap of approximately 3mm or less between the sesamoid and the navicular.

I 型:是胫骨后肌腱中的籽骨。籽骨和舟骨之间有一个约3mm或更小的间隙。

Type II: consists of an accessory bone, up to 1.2cm in diameter, where synchondrosis develops between it and the navicular.

II型: 由副骨组成，直径可达1.2厘米，在副骨与舟状骨之间形成软骨融合。

Type III: is the fused accessory navicular resulting in a large cornuate shaped navicular.

第三型:是融合的附属舟状骨，形成一个大的角状舟状骨。

Clinically Relevant Anatomy 临床相关的解剖学

The navicular is an intermediate tarsal bone on the medial side of the foot, which articulates proximally with the talus. Distally it articulates with the three cuneiform bones. In some individuals it also articulates laterally with the cuboid. The tibialis posterior tendon inserts into the navicular bone. Tibialis posterior is an inverter of the foot, assists in the plantar flexion of the foot at the ankle and also has a major role in supporting the medial arch of the foot.  This can be compromised where there exists an abnormal insertion of the tendon into the accessory navicular bone  and result in a loss of suspension of the tibialis posterior tendon, possibly causing peroneal spastic pes planus or simple pes planus. However, the cause and effect relationship between the accessory navicular and pes planus is speculative as there is no clear proof of that relationship. 

舟骨是足内侧的中间跗骨，其与距骨形成近侧关节，与三个楔骨形成远侧关节。在一些人中，它也与骰骨形成横向关节。胫骨后肌腱连接舟骨，胫骨后肌是足部的转向器，有助于足踝屈曲，并且还在支撑足弓内侧起主要作用。如果肌腱异常连接副舟骨，导致胫骨后肌腱悬吊力丧失，导致腓骨肌挛缩或单纯的紧张。然而，副舟骨和扁平足之间的因果关系是推测性的，因为没有明确证据证明这种关系。

The presence of a type I or II accessory navicular is also a cause of Posterior Tibial tendinopathy as the insertion of the Tibialus Posterior tendon onto the accessory navicular is more proximal (dashed line). Leverage of the malleolus on the Tibialus Posterior tendon is reduced increasing stress on the tendon. 

I型或II型副舟骨的存在也是胫骨后肌腱病变的原因之一，因为胫骨后肌腱连接副舟骨上，位置更近（虚线）。踝骨在胫骨后肌腱上的杠杆作用减少，导致肌腱上的应力不断增加。

The calcaneal pitch angle is also reduced in patients with a symptomatic accessory navicular than in normal subjects.

与正常受试者相比，有症状的副舟骨患者的跟骨倾角也会降低。

Epidemiology /Etiology 流行病学和病因学

The foot and ankle have numerous accessory ossification areas, with the most common being the accessory tarsal navicular bone which occurs in 4-14% of the population. 

足部和踝部有许多副骨化区，最常见的是副跗骨舟骨，占人口的4-14%。

1. An accessory navicular bone is present in ~10% of the population

2. It first appears in adolescence, with incidence of 4-21% in children.

3. It is more common in females 

4. Reported prevalence bilaterally is ~70% (range 50-90%)
   

    1、大约10％的人存在副舟骨

    2、首先出现在青春期，儿童的发病率为4-21％。

    3、女性更常见

   4、双侧患病率约为70％（范围50-90％）

People who have an accessory navicular are often unaware of the condition as it causes no symptoms. Some individuals, however, will develop accessory navicular syndrome, a painful condition where the bone and/or posterior tibial tendon become aggravated. This can result from any of the following:

有副舟骨的人通常不会知道，因为它不会引起任何症状。然而，有些人会发展成副舟骨综合征，这是一种骨和/或胫骨后肌腱不断加重的疼痛状态。这可由下列任何一项引起:

1. Trauma, such as a foot or ankle sprain

2. Chronic irritation from shoes or other footwear rubbing against the accessory bone

3. High levels of activity or overuse

    1、外伤，如脚或脚踝扭伤

    2、鞋摩擦副舟骨引起的慢性刺激

   3、高强度或过度的足踝活动

Characteristics/Clinical Presentation  特征/临床表现

1. Typically seen in young females (10-20 years of age) complaining of mid food/arch pain which may be insidious or post trauma

2. Difficulty getting comfortable footwear

3. Prominent navicular

4. Tenderness over the prominence

5. Pain over the posterior tibialis tendon and reduced mobility in the Achilles tendon in chronic cases

6. pes planus is often present

7. Inflamed bursa

   1、通常见于年轻女性(10-20岁)，她们抱怨中足/足弓疼痛，这可能是潜在的或创伤后的

    2、很难买到舒适的鞋子

    3、舟骨突出

    4、突出处压痛

    5、慢性患者胫后肌腱疼痛，跟腱活动能力下降

    6、通常存在扁平足

    7、滑囊炎

Differential Diagnosis   鉴别诊断

1. Stress fracture   应力骨折

2. Tendinopathy   肌腱病变

3. Medial tuberosity fracture   内侧结节骨折

4. Bone Tumor   骨肿瘤

5. Kohler’s disease   科勒氏病

Diagnostic Procedures   诊断流程

1. X-Ray: An accessory navicular is often clear to see in standing AP and lateral views, but in some cases an oblique view is also required in order to fully diagnose the extent of the navicular abnormality. Bilateral investigations are often done as there is a high incidence of symmetrical abnormalities.

2. When examining the lateral weight bearing X-ray, alignment of the talonavicular cuneiform and first metatarsal dorsal should be carefully examined as well. “Sag” at this joint indicates structural integrity of the area.

3. In rare cases, an MRI or CT is indicated in order to exclude a tumor, fracture of the medial tuberosity, or bone marrow edema.

1、X线片:副舟骨在站立AP和侧位片通常清晰可见，但在某些情况下，为了充分诊断舟骨异常的程度，还需要斜位片。由于对称性异常的发生率很高，因此常常进行双侧拍片。

2、在检查外侧负重X线时，还应仔细检查距舟楔骨和第一跖骨背侧的对齐情况。该关节处的“凹陷”表示该区域的结构完整。

3、在罕见的病例中，为了排除肿瘤、内侧结节骨折或骨髓水肿，需要进行MRI或CT检查。

Examination   检查

Patients with an accessory navicular may present with complex pain patterns requiring a thorough examination. The examination should include key assessments:

1. Differentiation of the navicular prominence from the talar head prominence in flat foot deformities by inverting and everting through the subtalar joint with a thumb over the bony prominence.

2. Assessing for any loss of structural integrity of the longitudinal arch is important as this component of the deformity will not be corrected by surgical treatment where surgery is required. 

3. Thorough gait examination.

副舟骨患者可能出现复杂的疼痛模式，需要进行彻底的检查。检查应主要包括:

1、通过拇指在骨突上内翻和外翻距下关节，使舟骨突起与扁平足畸形中的距骨突出区分开来。

2、评估任何纵弓结构完整性的丧失是很重要的，因为在需要手术的情况下，这一畸形不会通过手术治疗得到纠正。

3、完全的步态检查。

Medical Management  治疗

Conservative:   保守

1. Physical therapy   

2. Medications. Oral nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, may be prescribed. In some cases, oral or injected steroid medications may be used in combination with immobilisation to reduce pain and inflammation. 

    1、物理治疗

    2、药物疗法：口服非甾体类消炎药(NSAIDs)，如布洛芬。在某些情况下，口服或注射类固醇药物可与固定相结合，以减少疼痛和炎症。

Surgical: Depending upon the severity of symptoms, non-operative or conservative treatment should be maintained for at least 4- 6 months before any surgical intervention.

手术治疗:根据症状的严重程度，非手术治疗或保守治疗4- 6个月无效，再进行手术治疗。

 Surgeries that can be performed depending upon the condition and symptoms

The  procedure excising the boney prominance in conjunction with a reattachment of the posterior tibial tendon. The posterior tibial tendon is split and is reattached further up the medial side of foot to provide increased support to the longitudinal arch.

根据病情和症状，可以进行手术

切除副舟骨与胫骨后肌腱止点重建。 分离胫骨后肌腱并在足内侧重建，以增加对纵弓的支撑。

After surgery the lower leg is put into a cast for 4 weeks, which is moulded into the shape of the arch, with the foot maintained in a plantigrade position. Partial weight bearing is indicated for 8 weeks after which full weight bearing is permitted. Once the cast is removed, a strength and conditioning programme is highly recommended. 

手术后，将小腿石膏固定4周，脚保持在平衡位置，足底塑成拱形，保持在平衡位置。部分负重8周后，完全承重。一旦拆除了石膏，强烈建议使用强度和调节训练。

Occasionally, a limited fusion of the cuneiform metatarsal or talonavicular joints is also recommended. The rationale and efficacy of this operation have been questioned however.

有时，也采取楔骨跖骨或距舟关节的有限融合，然而，此方法的理由和效果受到质疑。

Arthrodesis may be a reasonable treatment option in selected cases of patients with symptomatic recalcitrant Type II accessory naviculars that are large enough to accept small fragment screws.

对于有症状的顽固性II型副舟骨，如副舟骨足够大可用螺钉固定，关节融合(舟骨与副舟骨)术可能是一个合理的治疗选择。

Physical Therapy Management   物理治疗

If the accessory navicular bone becomes problematic, physical therapy may be prescribed. 

如果副舟骨出现问题，可以进行物理治疗。

This includes use of therapeutic modalities to relieve pain, increase strength and stability in the foot. An accessory navicular bone is often linked to posterior tibial dysfunction and pes planus. In some cases orthotics may be indicated.

1. Well padded shoe orthotics should be worn for arch support. This decreases direct pressure over the navicular.

2. Strength and conditioning exercises for the peroneal and posterior tibialis muscles.

3. Strengthening of the intrinsic foot muscles and the lateral rotators of the pelvis.

4. Activity modification in the initial stages, such as limiting or stopping any strenuous activities which may cause the accessory navicular bone to become symptomatic.

5. Gait re-training and stability exercises.

包括减轻疼痛，增加足部的力量和稳定性。副舟骨常与胫骨后肌功能障碍和扁平足有关。在某些情况下可能需要矫正。

1、用鞋垫矫正器支撑足弓，可减少对舟骨的直接压力。

2、腓骨肌和胫后肌的力量和调节练习。

3、加强足部固有肌肉和骨盆侧旋转训练。

4、开始阶段的活动，如限制或停止任何可能导致副舟骨症状的剧烈活动。

5、步态训练和稳定性训练。

Some examples of functional posterior tibialis strengthening:

胫骨后肌功能强化训练指导：

副舟骨