Kosinskaya radiography

Differential diagnosis and pathological criteria

The diagnosis of coxarthrosis is established exclusively in the presence of a confirmed combination of clinical and radiographic criteria (Recommendation strength grade C). Before making a final verdict, the diagnostician must conduct a thorough differential analysis, as many conditions present a similar clinical and radiological picture.

Certain symptoms require the mandatory exclusion of other disorders: the onset of pain at rest or during sleep, as well as stiffness or pain in other joint groups (wrist, elbow, shoulder, or knee joints).

Main pathologies for differential diagnosis:

• Inflammatory arthritides: Bekhterev's disease, rheumatoid, psoriatic, and reactive arthritides, gout, and pseudogout (pyrophosphate arthropathy).
• Arthritides in systemic conditions: systemic lupus erythematosus (SLE).

It is crucial to timely identify conditions that mask hip joint pathology. Primarily, these include lumbosacral osteochondrosis and radiculopathies, where pain is localized in the lower back but radiates to the lower extremities and directly into the hip region.

Conservative treatment and the role of the radiological stage

Management of patients with degenerative-dystrophic changes should be continuous throughout life. It requires regular dynamic monitoring. The choice of technique directly depends on the clinical picture and the radiological stage of the disease (including according to the Kosinskaya classification).

Goals of the prescribed therapy:

1. Reduction of pain severity.
2. Maximum preservation of articular cartilage.
3. Stabilization or improvement of joint function.
4. Prevention of the progression of functional insufficiency.
5. Improvement of quality of life.
6. Minimization of adverse side effects from pharmacotherapy.

Conservative (non-surgical) treatment, including diet therapy, drug and non-drug approaches, as well as injection techniques, is indicated at all stages of osteoarthritis development. Furthermore, conservative support is necessarily continued even after surgical interventions.

Indications for surgery

Surgical treatment is divided into joint-sparing methods and arthroplasty (joint-replacing surgery).

In the vast majority of cases, radical surgery is prescribed at late stages. The key radiological indication is stage III according to the Kosinskaya classification (corresponding to stage III or IV according to the Kellgren-Lawrence system). Surgery at earlier stages is an exception and is performed only in the presence of extremely pronounced, persistent pain syndrome that is refractory to conservative management.

Additional conditions required for surgical intervention:

• Complete exclusion of any extra-articular causes of pain.
• Absence of pronounced joint space narrowing on functional radiography images.
• Presence of signs of meniscal injury (grade III and higher) according to magnetic resonance imaging data.

Joint-sparing surgery: osteotomy and arthroscopy

Corrective periarticular osteotomies (Recommendation strength grade B) are indicated for adult patients with a complete lack of response to conservative therapy. The optimal diagnostic window for their performance is considered to be stage I–II of gonarthrosis (according to Kosinskaya or Kellgren-Lawrence).

Main clinical and anatomical situations for osteotomy:

• Varus deformity combined with predominant involvement of the medial compartment.
• Valgus deformity against the background of lateral compartment involvement.

The intervention is localized at the proximal tibial metaphysis or distal femoral metaphysis — the choice depends on the severity of segment deformity. Tibial osteotomy often requires mobilization of the proximal tibiofibular joint or an additional fibular osteotomy. The surgeon must account for the joint line inclination in the frontal and sagittal planes, striving to minimize its artificial alteration. The entire concept is built on the biomechanical restoration of the axis.

The role of arthroscopy in gonarthrosis in modern practice is strictly limited. Its purpose is to confirm the diagnosis and plan treatment only when non-invasive methods (radiography, MRI) have failed to provide the necessary information. If arthroscopy is performed, its main principle is the minimum possible meniscal resection to preserve its function. Meniscal extrusion leads to cartilage and subchondral bone overload, pain, and progression of osteoarthritis. It is important to remember that at stage III of the disease, arthroscopy (including lavage and debridement) has proven ineffective — it cannot halt the degenerative process.

Class and exam questions

What else to study on this topic

• Biomechanical concept and limb axis restoration in periarticular osteotomies
• Pathogenesis of osteoarthritis progression due to meniscal extrusion
• Technique of tibial and fibular osteotomy
• Specifics of pain syndrome in lumbosacral osteochondrosis and radiculopathies
• Comparison of radiological classifications of osteoarthritis by Kosinskaya and Kellgren-Lawrence

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.