Avascular Necrosis (AVN) / Osteonecrosis

When Bone Tissue Begins to Die — Early, Expert Intervention Is the Most Powerful Tool You Have.

It often begins with a pain that seems disproportionate — a deep, persistent ache in the hip, shoulder, knee, or another joint that does not quite match any clear injury or obvious cause. Perhaps it appeared after a period of corticosteroid treatment. Perhaps it followed a fracture, a dislocation, or a period of heavy alcohol use. Or perhaps it developed with no identifiable trigger at all — leaving you confused, concerned, and searching for answers.

Avascular Necrosis — also known as Osteonecrosis — is a serious, progressive condition in which the blood supply to a section of bone is disrupted, causing the bone tissue to die. Without intervention, this process can lead to the structural collapse of the affected bone and, ultimately, the destruction of the adjacent joint — a devastating outcome that profoundly impacts mobility, independence, and quality of life.

But here is what every patient with AVN needs to know — and what far too few are told at diagnosis:

The stage at which treatment begins is the single most important factor in determining the outcome. Early, expert physiotherapy intervention — integrated with appropriate medical management — can slow or halt disease progression, protect the affected joint, preserve bone integrity, and maintain functional independence for as long as possible. In many cases, it can delay or even prevent the need for joint replacement surgery.

At Activelife Physiotherapy, we specialise in the comprehensive physiotherapy management of Avascular Necrosis — delivering expert, evidence-based care that protects your joint, preserves your function, and supports your long-term quality of life at every stage of this condition.

What Causes Avascular Necrosis?

AVN results from any condition or event that sufficiently disrupts the blood supply to bone. Causes are broadly categorised as traumatic and non-traumatic:

Traumatic Causes:
  • Hip fracture or dislocation — direct disruption of the retinacular blood vessels supplying the femoral head — the most clearly understood traumatic mechanism
  • Femoral neck fracture — particularly displaced fractures that disrupt the intraosseous blood supply
  • Ankle fracture or dislocation — disrupting the blood supply to the talus
  • Scaphoid fracture — particularly proximal pole fractures
  • Any fracture or dislocation disrupting the blood supply to a vulnerable bone
  • Corticosteroid Use: Most common cause (~35%); long-term use reduces bone blood supply.
  • Alcohol Abuse: Heavy intake leads to fat buildup and blocked bone circulation.
  • Sickle Cell & Blood Disorders: Abnormal blood cells block vessels, causing bone damage.
  • SLE (Lupus): Disease and steroid treatment both increase AVN risk.
  • Gaucher’s Disease: Fat accumulation in bone marrow disrupts blood flow.
  • Decompression Sickness: Gas bubbles block bone vessels (common in divers).
  • HIV & Therapy: Infection and medications affect blood flow and bone health.
  • Radiation Therapy: Damages bone blood vessels over time.
  • Idiopathic: No clear cause; possibly due to hidden blood clotting issues.

Recognising the Symptoms

Early Stage Symptoms (Stages 1–2):

  • Deep, aching joint pain — often poorly localised and difficult to attribute to a specific cause
  • Groin pain — the most common early presentation of hip AVN, reflecting the deep location of the femoral head
  • Pain that is activity-related initially — present during and after weight-bearing activity, but easing with rest
  • No external signs — no visible swelling, redness, or deformity in the early stages
  • Gradual onset — often dismissed or attributed to muscle strain or overuse in the early stages

Intermediate Stage Symptoms (Stages 2–3):

  • Progressive pain — increasing in severity and beginning to occur at rest
  • Night pain — deep bone pain disturbing sleep
  • Restricted range of movement — particularly hip internal rotation and flexion
  • Antalgic gait — a limping, pain-relieving walking pattern
  • Stiffness — particularly notable after periods of rest

Advanced Stage Symptoms (Stages 4–5):

  • Severe, constant pain — significantly limiting all daily activities
  • Markedly restricted joint movement — significant loss of functional range of motion
  • Profound gait disturbance — significant limp, difficulty walking even short distances
  • Functional dependence — difficulty with dressing, stairs, getting in and out of a car
  • Muscle wasting — significant atrophy of the hip, gluteal, and thigh muscles from disuse and pain inhibition

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