Differential diagnosis of osteoarthritis

Providing an effective therapy for osteoarthritis and recurrence of the disease depends largely on the use of standardized approaches to its diagnosis and differential diagnosis. Therefore, in this article, the differential diagnostic criteria and standards for assessing the arthrological status in patients with osteoarthrosis (including questionnaires SF-36, HAQ, AIMS, EuroQol-5DHflp.) Are generally accepted in world practice.

The use of these criteria and standards in practical medicine will allow doctors of various specialties (rheumatologists, general practitioners, orthopedic traumatologists, etc.) to unify the definition of the stage, the severity of pathological signs, and the assessment of the functional state of the musculoskeletal system in osteoarthrosis.

[1], [2], [3], [4], [5]

Algorithm for the diagnosis of osteoarthritis

1. Anamnesis analysis: consideration of the hereditary factor, injuries, inflammatory and metabolic lesions of the joints, vibration factor, sports, nature of work.
2. Evaluation of orthopedic status: flatfoot, posture, skeletal deformities.
3. Neuroendocrine status, regional circulatory disorders.
4. The nature of the flow of articular syndrome: slow gradual development.
5. Localization of lesions: joints of the lower limbs, hands, spine.
6. Clinical evaluation of articular syndrome:
   1. pain of the "mechanical" type, increases with exertion and decreases at rest;
   2. the presence of periodic "blockade" of the joint;
   3. deformity of the joint is primarily due to bone changes.
7. Typical radiological changes: subchondral osteosclerosis, narrowing of the joint space, intraosseous cysts, osteophytosis.
8. The absence of pathological changes in the hemogram, synovial fluid (in the absence of reactive synovitis).
9. Differential diagnosis with arthropathies listed below.

[6], [7], [8], [9], [10], [11]

Differential diagnosis of osteoarthritis

Osteoarthrosis and arthritis of various origins are most often differentiated - rheumatoid, infectious, metabolic.

1. Rheumatoid arthritis. Osteoarthritis of the knee joints and small joints of the hands (Heberden and / or Bouchard nodes) is often complicated by secondary synovitis, which in some cases may recur, which requires differential diagnosis with rheumatoid arthritis.

Osteoarthritis is characterized by a gradual, sometimes imperceptible, onset of the disease, the onset of rheumatoid arthritis - more often acute or subacute. Osteoarthritis is more often detected in women with hypersthenic body type.

Morning stiffness in osteoarthritis is mild and does not exceed 30 minutes (usually 5-10 minutes).

Osteoarthrosis is characterized by the “mechanical” nature of the pain syndrome: pain arises / intensifies when walking and in the evening hours and decreases at rest. Rheumatoid arthritis is characterized by the "inflammatory" nature of the pain syndrome: pain occurs / increases at rest, in the second half of the night and in the morning hours, and decreases when walking.

Rheumatoid arthritis is characterized by a predominant lesion of the small joints of the hands and feet, and the arthritis of the metacarpophalangeal and proximal interphalangeal joints of the hands is pathognomonic. Osteoarthritis often affects the distal interphalangeal joints (Heberden nodes); defeat of the metacarpophalangeal joints is not typical for osteoarthrosis. When it is mainly affected large joints that carry the greatest physical activity - knee and hip.

Of great importance in the differential diagnosis of osteoarthritis and rheumatoid arthritis is X-ray examination. On radiographs of joints affected by osteoarthrosis, there are signs of destruction of articular cartilage and an increased reparative response: sclerosis of the subchondral bone, marginal osteophytes, subchondral cysts, narrowing of the joint space. Sometimes osteoarthritis of the small joints of the hands occurs with erosion of the articular edges, which makes differential diagnosis difficult.

In osteoarthritis, the deformities characteristic of rheumatoid arthritis do not develop. Osteoarthritis rarely slightly increased levels of acute phase reactants ( in ESR, CRP, etc.) Are not characterized by detection of rheumatoid factor (RF) in the blood serum for him.

2. Infectious arthritis (septic, tuberculosis, urogenital) can be distinguished due to their clear clinical picture (acute onset, rapid development and course, severe pain and severe exudative phenomena in the joints, hectic fever, a shift in blood count, the effect of etiotropic therapy).
3. Metabolic (microcrystalline) arthritis / arthropathy. Thus, acute, paroxysmal articular episodes characterized by high local activity, localization of the process in the metatarsophalangeal joint of the first toe, and clear radiological changes are characteristic of gouty arthritis.

Differential diagnostic signs of osteoarthritis and gouty arthritis

Sign of	Osteoarthritis	Gagged
Floor	Equally common in men and women	Mostly in men
Onset of the disease	Gradual	Sharp, subacute
Course of the disease	Slowly progressing	Recurrent with acute attacks of arthritis
Localization	Interphalangeal joints of hands, hip, knee joints	Mainly joints of the first toe, ankles
Geberden's Knots	Often	Absent
Tuffies	Absent	Often
X-ray changes	Joint space narrowing, osteosclerosis, osteophytes	"Punches"
Gyperuricemia	Missing	Is characteristic
Kidney damage	Not typical	Often
ESR	It happens slightly increased	In the period of the attack dramatically increased

Special attention and differential diagnosis deserve cases where a patient with chronic gout are determined by the clinical and radiological signs of secondary osteoarthritis. Often these patients are mistakenly diagnosed with primary osteoarthritis, and gouty attacks, especially in case of their subacute, are treated as recurrent reactive synovitis. It should be borne in mind that the pain during primary deforming arthrosis has a "mechanical" character, exacerbations of synovitis are softer, quickly disappear at rest, there are no tophi and characteristic radiological signs - "piercers".

Especially difficult is the differential diagnosis of coxarthrosis and coxitis in the early stage. These diagnostic signs allow to distinguish between these diseases.

Often there are problems in the differential diagnosis of gonarthrosis with reactive synovitis and isolated arthritis of the knee joint (especially with the development of secondary osteoarthritis). Taking into account the nature of the pain syndrome and radiological signs, it is important to note the different severity of local inflammatory reactions, restriction of movements, as well as the specific nature of the deformities of the joint.

Differential diagnostic signs of coxarthrosis and coxitis

Symptom	Coxarthrosis	Cocktail
Start and Current	Slow, inconspicuous	Sharper and faster
Nature of pain	Mechanical (under load, more in the evening)	Inflammatory (alone, more in the morning)
Mobility restriction	Rotation and leg abduction first	First of all hip flexion
Changes in blood, indicating inflammation	Missing or minor	Expressed
Radiography	Small osteosclerosis of the iliac depression, punctate calcifications in the area of its upper edge, tapering the edges of the fossa of the femoral head	Veiled radiographs in the area of periarticular tissues (exudate), periarticular osteoporosis
ESR	Rarely up to 30 mm / h	Often high (30-60 mm / h)

Differential diagnostic signs of gonarthrosis and gonarthritis

Symptom	Gonarthrosis	Gonarthritis
Nature of pain	Mechanical or starting	Inflammatory
Local inflammatory reactions	Minor	Significant
Soreness to palpation	Slight, only along the joint space	Significant, diffuse
Joint deformity	Mainly due to bone changes	Mainly due to changes in the soft periarticular tissues
Mobility restriction	Mild	Pronounced, sometimes to complete immobility
Inflammatory changes in the blood	Absent	Are observed
X-ray of the joint	Osteosclerosis, osteophytosis, narrowing of the joint space	Osteoporosis, joint space narrowing, joint surface arrest, fibrous and bone ankylosis

Osteoarthritis of the knee and some other joints is sometimes difficult to distinguish from periarthritis, which have the same localization and course without marked inflammatory changes. In these cases, the clinical and radiological features of periarthritis matter:

• pain only with certain movements associated with areas of the affected tendon (for example, mainly abduction of the arm with scapulohumeral periarthritis);
• restriction only active movements, while the passive remain in full;
• limited pain on palpation (ie, the presence of pain points);
• the absence of signs of damage to this joint on radiographs;
• the presence of calcificats in soft periarticular tissues and periostitis.

[12], [13], [14], [15], [16]