Shoulder Instability
What You Need to Know
- Shoulder instability usually occurs when the lining of the shoulder joint (the capsule), ligaments or labrum become stretched, torn or detached, 允许肩关节球(肱骨头)完全或部分地移出臼外.
- Individuals with shoulder instability usually feel pain when the shoulder “gives way.”
- 诊断肩部不稳定包括身体检查和x光检查，以确定肩部不稳定的原因或排除肩部疼痛的其他原因.
- Treatment for shoulder instability includes both non-operative and surgical options.
What is the shoulder joint?
The shoulder is a ball-and-socket type of joint that permits a wide range of movement. 它的骨结构包括上臂骨(肱骨)和肩胛骨的浅腔(盂). The ball of the humerus (humeral head) is meant to stay close to the socket, like a ball bearing in a holder. The humeral head is held into the socket by the lining of the joint (the capsule), thickenings of the capsule called ligaments and a cartilage rim (the labrum) (Figure 1).
What is shoulder instability?
While the shoulder has great range of motion, it can lose its stability. The following are types of shoulder instability:
Shoulder Dislocation and Subluxation
With significant trauma to a previously normal joint, the humeral head can be forcefully subluxed or dislocated. 当肱骨部分快速滑入和滑出时，发生肩关节半脱位(图2)。. 肩关节脱位发生在肱骨完全脱离肩关节时(图3)。. 它可能会在一段时间后恢复原状，或者可能需要在医疗帮助下恢复原状.
The capsule, ligaments or labrum can be stretched, torn or detached from the bone during shoulder subluxation and dislocation. When the humeral head is back in place (reduced; Figure 4), 这些结构可以在松散或拉伸的位置愈合，这可能会增加未来发生半脱位或脱位的风险(图5)。. With each additional episode, further tissue damage can occur, increasing the tendency toward future instability.
Labral Tear
Shoulder instability can occur whenever the labrum is torn or peeled off of the glenoid. This can occur after a shoulder dislocation, shoulder trauma or as a result of repetitive motion (like throwing a baseball).
Genetic Condition
有些人天生就有一些松弛的肩部韧带(他们有一个松散或宽敞的囊)。. 对于这些人来说，不稳定可以在没有任何创伤或相对较小的伤害的情况下发生. 一些患者也可能有导致关节松动的遗传疾病，使他们容易发展为肩部不稳定或虚弱.
What are the symptoms of instability?
肩关节不稳定的人有时会感到肩关节脱臼或“脱臼”." This is commonly associated with pain. Often, the episodes of giving way occur with specific activities or positions of the arm, such as throwing a ball or reaching behind the body.
其他症状包括手臂/肩部活动范围减小、肿胀和瘀伤.
How is shoulder instability diagnosed?
A complete history and physical examination should be done by a physician. 检查包括触诊检查压痛点，以及确定活动范围和力量. 肩关节的松弛程度也可以在检查过程中通过特定的测试来评估. X-rays 通常是为了获得不稳定的可能原因的信息，并排除其他原因引起肩痛吗, such as a fracture.
Additional tests, such as a magnetic resonance imaging (MRI) scan or a dye test (arthrogram) with or without a computed tomography (CT) scan, are occasionally done to further evaluate the bones and tissues of the shoulder joint. However, these scans are not required in all patients with instability.
Johns Hopkins Shoulder and Elbow Surgery
我们的骨科肩关节和肘部专家团队诊断和治疗常见和复杂的肩关节和肘部疾病, including rotator cuff tears, ulnar collateral ligament (UCL) tears, and shoulder and elbow arthritis. Our specialists are also skilled in different shoulder replacement approaches.
How is shoulder instability treated?
After a shoulder has dislocated or subluxed, it is important to rest it and avoid aggravating activities for a couple of days. If the pain is significant, such as following a traumatic dislocation, 吊带通常用于提供临时固定-肩部支撑也可能是一些患者的选择. Once the pain and swelling have subsided, range of motion exercises are started. Strengthening exercises can begin as motion improves. 通常，锻炼项目是在训练有素的物理治疗师的配合下完成的.
在运动前后用冷敷袋或冰袋敷肩可以帮助减轻疼痛和肿胀. NSAIDs (nonsteroidal anti-inflammatory drugs), which include aspirin, ibuprofen (Motrin, Advil, Nuprin, etc.) or ibuprofen-like drugs like Aleve can be used to reduce pain and swelling. You should check with your physician with any questions, as a number of different kinds of drugs are available, and they may have side different effects.
治疗的目标是恢复肩部运动，增加肩部周围肌肉的力量. Strong muscles, especially those of the rotator cuff, are required to protect and prevent the shoulder from re-dislocating or subluxing. 一旦肩部功能完全恢复，患者可逐渐恢复活动.
When would I need surgery?
尽管经过了一段时间的物理治疗，肩膀的活动和力量都恢复了, the shoulder may still be loose or unstable. Treatment options then consist of 1) activity modification and 2) surgery. 活动矫正主要是对仅在某些活动中出现不稳定的患者的一种选择, such as playing basketball or overhead racquet sports. In these patients, 避免活动可以完全消除他们的半脱位或脱位发作.
如果患者不愿意放弃引起发作的活动或运动，可以考虑手术治疗, and in patients in whom instability occurs during routine daily activities (dressing, sleeping, etc.) or work.
手术包括在麻醉下对肩部进行检查，以充分评估不稳定的程度和方向，同时肩部周围的肌肉完全放松. An arthroscope 常用于检查肩关节的内部来评估关节及其软骨. 关节镜可以直接评估关节唇和肩袖肌腱的状况. 在数量有限的选定患者中，其松动或松弛程度相对较轻, it may be possible to stabilize the shoulder by arthroscopic techniques.
To correct severe instability, open surgery is often necessary. 在肩膀上做一个切口，移动肌肉以进入关节囊, ligaments and labrum (Figure 6).
These structures are then either repaired, reattached or tightened depending on the tissue injury identified at surgery (Figure 7). 修复可以用简单的缝合线或将缝合线连接到金属或固定在塑料或可吸收的钉或锚上. 这些锚被插入骨头并固定缝合线，缝合线用于重新连接或收紧韧带. These anchors stay in the bone permanently.
How long is rehabilitation after surgery?
手术后的恢复过程在某种程度上取决于外科医生进行的手术类型. Usually, range of motion of the hand, wrist and elbow begin the day after surgery. 大多数患者在手术后的3到7天内就可以写字和用手臂吃饭了. 手术后一到四周开始进行有监督的物理治疗. Full range of motion usually returns after six to eight weeks. Strength usually returns in three months. Driving sometimes take several weeks. 恢复工作或体育活动取决于该活动的具体性质和要求，但对于重体力劳动者或高水平运动员来说，可能需要长达一年或更长时间. With surgery, 不稳定性复发的机会很低(3% - 5%)，大多数患者可以恢复以前的活动.
Shoulder Injuries | Q&A with Dr. Edward McFarland
Shoulder specialist Edward McFarland, M.D., talks about shoulder dislocation and subluxation (partial dislocation). He discusses common causes of these shoulder injuries, how they can be treated and what the recovery process looks like.
