膝关节响声/异响：咯噔或咔哒或嘎吱或吱拗或唦唦或捻发音等异响的原因分析
作者：医学博士Jonathan Cluett更新于2023年5月9日
译者：陶可（北京大学人民医院骨关节科）
膝关节发出的爆裂声、折断声、破裂声或嘎吱声通常是无害的，这可能只是关节老化的结果。但它们也可能是严重受伤的迹象，例如半月板撕裂，或膝关节炎的早期征兆。如果噪音伴有疼痛或关节活动能力减退或丧失，则尤其如此。
捻发音是用于描述骨骼和软骨之间摩擦产生的刺耳声音或感觉的术语。它可以影响身体的不同部位关节，最常见于膝关节。
本文解释了膝关节异响的5个常见原因，以及何时需要向医疗工作者或骨科医生等专家寻求治疗帮助。
1. 气泡：滑液重新分布
膝关节异响通常是无害的，不仅影响老年人，也影响年轻人。在这种情况下，当空气渗入关节间隙内的润滑液（称为滑液）并产生微小气泡时，可能会产生噪音。
当膝关节弯曲或伸展时，气泡会破裂，发出爆裂声或破裂声。即便如此，这种情况不会引起疼痛，被认为是无害的。
2. 膝关节半月板撕裂或游离体
当膝关节出现机械故障时，就会发生膝关节爆裂。每当膝关节弯曲时，可能会感觉好像有什么东西“卡住”了膝关节。伴随着爆裂声或破裂声，可能会出现膝关节疼痛、肿胀、压痛、发红和僵硬。
这些很可能是半月板撕裂的表现。此时，半月板（一块C或O形软骨，充当胫骨和股骨之间的缓冲垫片）因创伤性损伤或膝关节进行性退化而部分或完全撕裂。
虽然有些半月板损伤会自行愈合（早期或1/2度半月板有一定的自愈能力），但涉及更深组织的半月板撕裂则没有愈合所需的血液供应。严重的撕裂可能需要关节镜清创术来修剪和铆钉缝合修复损伤。在其他情况下，可能需要通过手术重新连接撕裂的断端。
此外，膝关节腔游离体也可以出现类似半月板撕裂的膝关节卡顿及异响。
3. 跑步者膝：下肢力线不正或髌骨轨迹不良
当股骨和髌骨承受过大压力时，可能会出现膝关节捻发音。这可能是由于过度使用受伤或膝关节的骨骼未正确对齐（下肢力线不正或髌骨轨迹不良）而导致的。
当这种情况发生时，膝关节的软骨会开始软化（早期退行性病变）和磨损，导致某些动作时发出爆裂声和疼痛：如爬楼梯、在斜坡上慢跑、在凹凸不规则的地形上跑步，或者只是比平常更努力地锻炼膝盖（如深蹲、靠墙静蹲或蹲便）。
这些都是髌股应力综合症（PFSS）的症状，也称为“跑步者膝”。髌股应力综合症（PFSS）在长跑运动员中很常见，但也可能影响严重跌倒或膝盖严重受伤的患者（如在车祸损伤了膝关节）。
髌股应力综合症（PFSS）最常通过休息、冰敷、抗炎药物、物理治疗和个体化锻炼计划来治疗。
4. 膝关节骨关节炎：退行性骨关节病
膝关节捻发音通常是膝骨关节炎(OA)的早期症状，也称为“磨损性关节炎”。膝关节骨关节炎是一种与衰老相关的疾病，膝关节软骨随着时间的推移逐渐磨损，导致疼痛、僵硬和膝关节活动范围减低。
膝关节弹响可能在早期没有疼痛，但随着骨关节炎(OA)症状的出现而逐渐恶化。
对于膝关节骨关节炎，由于膝关节内软骨逐渐软化和破裂（称为髌骨软化症），捻发音往往是慢性的（持续性或复发性）。
膝关节骨关节炎的治疗方法包括运动、减肥、热疗或冷疗以及非处方抗炎药。在严重的情况下，可能需要处方药、物理治疗、膝关节腔注射治疗或手术治疗。
5. 膝关节肌腱炎
膝关节异响也可能是由膝关节周围肌腱问题引起的。有时，肌腱肿胀（称为肌腱炎）会导致膝关节弯曲时肌腱卡在关节边缘。最常见的类型称为髂胫束肌腱炎ITBS。
髂胫束(IT)是一条从髋关节延伸到膝关节下方的肌腱。当髂胫束带肿胀或发炎时，当膝关节前后弯曲时，束带可能会卡在股骨末端（股骨外侧髁骨隆起处），从而发出咔哒声。
与问题发生在关节深处的机械爆裂声不同，这种爆裂声是在皮肤下方感觉到的。当您移动膝关节时，您经常会感觉到肌腱肿胀且移位。
休息、冰敷、抗炎药物和物理治疗（激素封闭治疗）可以帮助拉伸髂胫束并缓解症状。如果没有，可能会建议进行髋关节镜手术。
何时该去看医生
膝关节异响不一定是令人担忧的问题。但是，如果您在膝关节在屈伸活动时感到疼痛，请尽快让医生进行检查。这样做可以防止更严重的膝关节损伤——包括前十字韧带(ACL)损伤（每年影响美国100,000至200,000人）。
即使膝关节弹响并不疼痛，您可能仍然需要检查一下。在某些情况下，这可能是过度使用损伤或骨关节炎的早期迹象。减轻体重、更换鞋子或加强膝关节康复功能锻炼可能是解决病情或帮助缓解症状所需的全部方法。
最好的治疗方法是直接针对导致膝关节内部异常爆裂或异响的具体问题。
总之，膝关节异响可能完全无害，或者是关节老化的正常结果。这也可能是严重膝关节问题的征兆，特别是如果声音伴有疼痛或关节活动能力丧失。
膝关节异响伴疼痛的原因包括半月板撕裂、髌股应力综合征（跑步膝）、膝骨关节炎和膝肌腱炎。
Causes of Knee Popping or Snapping
By Jonathan Cluett, MD Updated on May 09, 2023
Knee popping, snapping, cracking, or crunching noises are usually harmless and may simply be the consequence of aging joints. But they could also be an indication of a serious injury, such as a torn meniscus, or an early sign of knee arthritis. This is especially true if the noises are accompanied by pain or the loss of joint mobility.
Crepitus is the term used to describe the grating sounds or sensations produced by friction between bone and cartilage. It can affect different parts of the body but is common in the knee.
This article explains five common causes of knee popping and when it‘s time to seek treatment from your healthcare provider or a specialist known as an orthopedist.
Common Causes of Knee Popping or Snapping
Verywell / Emily Roberts
Air Bubbles
Knee popping is often harmless and not only affects older people but younger ones as well. In such cases, the noise may arise when air seeps into the lubricating fluid within the joint space (called synovial fluid) and creates tiny bubbles.
When the knee is bent or stretched, the bubbles can burst, causing a popping or cracking sound. Even so, the condition doesn‘t cause pain and is considered harmless.
Meniscus Tear
Knee popping can happen when there‘s something mechanically wrong with the knee joint. It may feel as if something is “catching“ in the knee whenever it is bent. Along with a popping or cracking sound, there may be knee pain, swelling, tenderness, redness, and locking.1
These are all signs of a condition known as a meniscus tear. This is when the meniscus—a C-shaped piece of cartilage that acts as a cushion between the shinbone (tibia) and thighbone (femur)—is partially or fully torn due to a traumatic injury or the progressive degeneration of the knee joint.1
While some meniscus tears heal on their own, those involving deeper tissue don‘t have the blood supply needed to enable healing. The severe tears may require a procedure called arthroscopic debridement to trim and repair the injury. In other cases, the surgical reattachment of the torn ends may be needed.
Runner‘s Knee
Knee crepitus may develop when excessive stress is placed on the femur and kneecap (patella). This may occur due to an overuse injury or when the bones of the knee joint are improperly aligned.
When this happens, the cartilage in the knee joint can start to soften and wear away, causing popping sounds and pain with certain movements. This includes climbing stairs, jogging on an incline, running on irregular terrain, or simply exercising the knees harder than usual.
These are all signs of patellofemoral stress syndrome (PFSS), also known as “runner‘s knee.“ PFSS is common among long-distance runners but can also affect someone who has had a bad fall or hit their knee badly (such as during an auto accident).2
PFSS is most often treated with rest, ice application, anti-inflammatory drugs, physical therapy, and a structured exercise program.2
Knee Osteoarthritis
Knee crepitus is often an early sign of knee osteoarthritis (OA), also known as “wear-and-tear arthritis.“ Knee OA is an aging-related condition in which knee cartilage is gradually worn down over time, causing pain, stiffness, and a loss of the range of motion of the knee joint.
Knee popping may occur without pain in the early stages and become progressively worse as the other OA symptoms develop.
With knee OA, the crepitus will tend to be chronic (persistent or recurrent) due to the progressive softening and breakdown of cartilage within the knee (known as chondromalacia patella).3
Knee OA is treated with exercise, weight loss, heat or cold therapy, and over-the-counter anti-inflammatory drugs, In severe cases, prescription medications, physical therapy, cortisone knee injections, or surgery may be indicated.
Knee Tendonitis
Knee popping can also be caused by a problem with the tendons of the knee. There are times when swelling of tendons, known as tendonitis, can cause them to catch on the edges of a joint as the knee is bent. The most common type is called iliotibial band tendonitis.
The iliotibial (IT) band is a tendon that runs from your hip to just below your knee. When the band becomes swollen or irritated, it can get stuck on the end of the femur as the knee bends back and forth, causing an audible snap.4
Unlike mechanical popping where the problem is deep within the joint, this type of popping is felt just below the skin. You can often feel the swollen and displaced tendon as you move the knee.
Rest, ice, anti-inflammatory drugs, and physical therapy can help stretch the IT band and resolve the symptoms. If not, arthroscopic hip surgery may be recommended.
When to See a Healthcare Provider
Knee popping is not necessarily a cause for concern. However, if you feel pain when your knee pops, have a healthcare provider look at it as soon as possible. Doing so may prevent a more serious knee injury—including anterior cruciate ligament (ACL) injuries that affect between 100,000 and 200,000 people in the United States each year.5
Even if the knee popping isn‘t painful, you may still want to have it checked out. In some cases, it may be an early sign of an overuse injury or osteoarthritis. Weight loss, a change of footwear, or knee-strengthening exercises may be all that is needed to resolve the condition or help ease symptoms.
The best treatments are targeted directly at the specific problem that is causing the abnormal popping or snapping inside the knee joint.
Summary
Knee popping or snapping can be entirely harmless or a normal consequence of aging joints. It can also be a sign of a serious knee problem, especially if the sound is accompanied by pain or the loss of joint mobility.
Causes of knee crepitus with pain include a torn meniscus, patellofemoral stress syndrome (runner‘s knee), knee osteoarthritis, and knee tendonitis.
Causes and Treatment of Knee Popping or Snapping (verywellhealth.com).
https://www.verywellhealth.com/popping-and-snapping-2549494.