Knee pain-causes overview
History -One or both knees are affected and if other jts are affected Onset , location, duration, severity and quality of the pain Aggravating and relieving factors If pain is persistent or occurs at night ( Night pain may indicate tumour , inflammatory arthritis or severe OA ) H/O Swelling including onset Joint stiffness H/O Locking or giving way Crepitus snapping or clicking ( limited value )
Examination –Full exposure both knees Compare both knees Observe walking , how pt goes from sitting to standing Look for genu valgum or varum Inspection and palpate both knees and surrounding structures ► Look for erythema , warmth , deformity ► Swelling → including bony swelling , jt effusion , bursal and soft tissue swelling ► Bony swelling around jt margins → often palpable in OA ► Persistent ↑ ing or unexplained bony swelling-think Tumour particularly if its away from jt line ► Bruising ► Quadriceps atrophy and tenderness Move the knees by extending and flexing as far as possible ( N range 0° of extension to 135° of flexion ) Active and passive ROM Ballotment- assessment for effusion Examine ipsilateral hip and lumbar spine ( looking for referred pain ) If needed examine other jts and for regional lymphadenopathy and any other signs of infection
Red flags
Infection –Sig swelling appeared acutely over < than 24 hrs One jt affected ( although upto 5th of people with septic arthritis ↑ than 1 jt is affected ) Knee pain severe or in people with pre-existing jt dis ( eg Rh A and OA ) out of proportion to the usual symptoms Fever ( absence does not exclude septic arthritis ) Nausea , vomiting or anorexia Systemically unwell ( common in children ) Risk factors for infection Knee replacement Rh arthritis IVDU Immunosuppression ( eg Diabetes, Long term corticosteroid use , alcoholism ) Adjacent skin infection or ulceration
Tumour –Bone tumour , Soft tissue sarcoma , Metastases , Haematological cancer or Neuroblastoma ↑ing , persistent or unexplained bone pain , tenderness , or swelling – especially if it is not in the knee jt itself but adjacent to the knee Pain at night or at rest Unexplained weight loss Previous cancer Sudden onset pain ( can happen in pathological fracture , Osteonecrosis ) Any lumps in adult which is ☼ > than 5 cm in dia ☼ deep to fascia ☼ fixed or immobile ☼ painful ☼ ↑ ing in size Children any unexplained mass which shows any such features ☼ deep to the fascia ☼ non – tender ☼ progressively enlarging ☼ associated with a regional lymph node that is enlarging ☼ larger than 2 cm in diameter ☼ recurrence after previous excision
Children and adolescents Patellofemoral pain Patellar subluxation /instability Osgood-Schlatters disease Jumper’s knee ( Patellar tendonitis ) Referred pain → Slipped capital femoral epiphysis Osteochondritis dissecans Hypermobility syndrome Infalmmatory conditions Tumours Osteomyelitis and septic arthritis Patellar tendonitis Discoid lateral meniscus
Adults –Patellofemoral pain – often bilateral Most common cause of anterior knee pain Trauma* (cruciate and collateal ligaments sprans , tears) Joint hypermobility syndrome Bursitis Inflammatory arthropathy Rheumatoid arthritis → typically causes symmetrical synovitis of the small jts of the hands and feet Septic arthritis Early osteoarthritis ( Previous injury ) Medial Plica syndrome
Older adults –Osteoarthritis ( Knees , hips , small jts of the hands – 1st Carpometacarpal jt and interphalengeal jts and 1st Metatarsophalangeal jt commonly affected ) Gout and Pseudogout Baker’s cyst → causes posterior knee pain Referred pain from OA of hip Degenerative menisceal tear Septic arthritis
Anterior knee pain–Patellar subluxation or dislocation Osgood Schlatters disease Patellar tendonitis Patellofemoral pain syndrome Isolated petallofemoral arthritis
Medial Knee pain – Medial collateral ligament sprain Medial menisceal tear Bursitis-Pes anserine bursitis Medial plica syndrome Osteoarthritis Osteonecrosis ( rarely )
Lateral Knee Pain –Iliotibial band syndrome Arthritis Lateral collateral ligament sprain Lateral menisceal tear
Bakers cyst Posterior cruciate lig injury
References; Further reading Diagnosis and management of soft tissue Knee Injuries Internal Derangements- Best practice evidence based guideline http://www.acc.co.nz/PRD_EXT_CSMP/groups/external_communications/ documents/guide/wcmz002488.pdf Knee pain assessment- http://cks.nice.org.uk/knee-pain-assessment http://www.pathways.scot.nhs.uk/Orthopaedics/PP_Knee_ET2004.pdf Evaluating acutely injured patients for Internal derangement of the Knee http://www.aafp.org/afp/2012/0201/p247.html General practitioners diagnosis and management of acute knee injuries :summary of an evidence based guideline http://aut.researchgateway.ac.nz/bitstream/handle/10292/6052/ Reid-General%20practitioner.pdf?sequence=5 Evaluation of Patients presenting with Knee pain:Part II Differential diagnosis http://www.aafp.org/afp/2003/0901/p917.html Evidence-based
Management of Acute Musculoskeletal Pain- A guide for Clinicians https://www.nhmrc.gov.au/_files_nhmrc/publications/attachments/ cp95_evidence_based_management_acute_musculoskeletal_pain_clinicians_131223.pdf https://meded.ucsd.edu/clinicalmed/pe_muscskelexam.pdf
