When speaking to the doctor or physiotherapist being able to describe the exact symptoms will help with diagnosis.
Page updated January 2024 by Dr Sheila Strover (Clinical Editor)
It is important to mention whether or not the symptoms came on after an injury, or whether they just appeared on their own.
Funny noises in the knee
A common knee noise is 'crepitus' which sounds like 'rice krispies' and can be felt with a hand on the knee. Other noises may include snapping or clunking.
-
Quote:
"A lot of patients visit outpatient clinics due to a concern that the [knee] noise is pathological. In most cases, the noise is physiological, and it is sufficient to explain the cause of the noise to patients and reassure them."
Citation: Song SJ, Park CH, Liang H, Kim SJ. Noise around the Knee. Clin Orthop Surg. 2018 Mar;10(1):1-8. doi: 10.4055/cios.2018.10.1.1. Epub 2018 Feb 27. PMID: 29564040; PMCID: PMC5851845.
Symptoms after injury
Immediate pain, rapid balloon-like swelling and incapacity suggests a disrupted vascular structure within the knee capsule, such as a cruciate ligament, or meniscus, or bone. Structures outside the capsule (eg collateral ligament) may have less dramatic symptoms when injured.
-
Quote:
"The medial collateral ligament (MCL) is the most common knee ligament to be injured during knee trauma.... as a result of either a direct valgus force to players’ knees or cutting maneuvers, when athletes plant a foot and suddenly shift their direction or speed....[it] may result in knee instability."
Citation: Vosoughi F, Rezaei Dogahe R, Nuri A, Ayati Firoozabadi M, Mortazavi J. Medial Collateral Ligament Injury of the Knee: A Review on Current Concept and Management. Arch Bone Jt Surg. 2021 May;9(3):255-262. doi: 10.22038/abjs.2021.48458.2401. PMID: 34239952; PMCID: PMC8221433.
Pain in the absence of injury
Pain may occur in the absence of injury, but still be very specific in nature - it can be gnawing in nature, like arthritic pain, or can be sharp and catching, like pain from a plica. The doctor will need to ask details about the exact nature of the pain and what type of movement brings it on.
Pain is often experienced at the front of the knee - so-called 'anterior knee pain' - and this may have several causes which need to be carefully investigated.
-
Quote:
"The main factors associated with unspecified knee pain among adolescents are being female, doing sports activities, being obese, and being older"
Citation: Saes MO, Soares MCF. Knee pain in adolescents: prevalence, risk factors, and functional impairment. Braz J Phys Ther. 2017 Jan-Feb;21(1):7-14. doi: 10.1016/j.bjpt.2016.04.001. Epub 2017 Jan 13. PMID: 28442078; PMCID: PMC5537448.
Evaluating stiffness
If the knee is inflamed and full of fluid it may feel stiff, but stiffness may also be caused by a true mechanical block to full movement. The physiotherapist's role is to optimise movement in the knee, reducing internal fluid, massaging adhesions and improving muscle strength. If there is a mechanical block to movement, like a bone spur or arthrofibrosis, then it may require surgery to achieve full motion.
If the knee can be fully bent, but when trying to straighten the joint it suddenly seems to find a mechanical block, then this is called 'locking'.
-
Quote:
"The common underlying causes of knee stiffness are injuries, infection, ....fracture fixation, arthroscopic surgery....and knee arthroplasty....[E]xtension loss is usually due to adhesions in the intercondylar notch or tibio-femoral compartments. In contrast, the loss of flexion is mostly due to adhesions in the suprapatellar pouch or the patello-femoral joint, and fibrosis or adhesion of the quadriceps muscles."
Citation: SVaish A, Vaishya R, Bhasin VB. Etiopathology and Management of Stiff Knees: A Current Concept Review. Indian J Orthop. 2020 Oct 20;55(2):276-284. doi: 10.1007/s43465-020-00287-0. PMID: 33927806; PMCID: PMC8046887.
Feeling uncertain about stability
Wearing away of the joint cartilage or the meniscus may cause a general wobbliness of the knee, but ligament tears are likely to cause instability in a particular direction.
A bit of broken joint cartilage or a loose flap of a torn meniscus can suddenly get caught temporarily between the bones in the knee, causing a sudden painful stumble which is called 'catching'.
Very often it is someone else who notices that your knee thrusts outwards with each step. This is called 'lateral thrust'. This can be due to a lack of the knee meniscus 'spacer' on one side. It is an issue which needs to be taken seriously as it means that the problem is still relatively early, when an intervention like an osteotomy or a meniscus transplant may restore function and prevent further damage.
-
Quote:
"Chronic instabilities present with mechanical symptoms such as locking, catching, clicking, or giving way, particularly with twisting movements.....Stability of the knee joint is [normally] maintained by the shape of the condyles and menisci in combination with passive supporting structures....[t]hese are....ACL,...PCL,...MCL, and ....LCL."
Citation: Kakarlapudi TK, Bickerstaff DR. Knee instability: isolated and complex. West J Med. 2001 Apr;174(4):266-72. doi: 10.1136/ewjm.174.4.266. PMID: 11290686; PMCID: PMC1071355.
-
Quote:
"Varus thrust is visualized during gait as the dynamic worsening or abrupt onset of varus (bow-leg) alignment as the limb accepts weight (stance phase), with a return to less varus and more neutral alignment during lift-off and the non-weightbearing (swing) phase of gait."
Citation: Chang A, Hochberg M, Song J, Dunlop D, Chmiel JS, Nevitt M, Hayes K, Eaton C, Bathon J, Jackson R, Kwoh CK, Sharma L. Frequency of varus and valgus thrust and factors associated with thrust presence in persons with or at higher risk of developing knee osteoarthritis. Arthritis Rheum. 2010 May;62(5):1403-11. doi: 10.1002/art.27377. PMID: 20213800; PMCID: PMC2921866.
Is the joint an odd shape?
Bow legs is a more permanent situation where one is unable to bring knees together without spreading the feet. Usually there are arthritic changes in the knee. Knock knees are the opposite.
Injury -
General symptoms -
2013 - Patellofemoral Pain - by Dr Ronald Grelsamer (Knee Surgeon)
2010 - Assessing the severely swollen knee after an injury - by Professor Adrian Wilson (Knee Surgeon)