Overview

A synovial fluid leak occurs when the lubricating fluid produced by a joint’s synovial membrane escapes the joint capsule into surrounding tissues or out through a wound or sinus tract. Leaks can result from trauma, joint surgery, degenerative tears, or inflammatory disease and may cause swelling, pain, or a persistent drainage tract. In Korea, diagnosis and management are provided by orthopedics, rheumatology, and specialized sports-medicine clinics using modern imaging and minimally invasive techniques.

What is a Synovial Fluid Leak?

Synovial fluid is the viscous fluid within synovial joints that reduces friction and nourishes cartilage. A synovial fluid leak (also called a synovial fistula, joint effusion leak, or wound leak) happens when joint capsule integrity is breached and fluid tracks into soft tissues or outside the body. Common forms include post-operative joint wound drainage, traumatic capsular tears with surrounding fluid collection, and ganglion or bursae communicating with a joint.

Symptoms

• Localized swelling or fluctuant cyst near a joint (e.g., knee, wrist, ankle)
• Clear, watery drainage from a surgical wound or sinus tract
• Joint stiffness and reduced range of motion
• Pain or discomfort, particularly with movement or weight-bearing
• Recurrent effusion (joint refilling after aspiration)
• Visible lump that may fluctuate in size with activity
• Signs of infection if the leak is contaminated (redness, fever, purulent drainage)

Causes

• Traumatic injury causing capsular or tendon sheath tears
• Postoperative wound dehiscence after arthroplasty or arthroscopy
• Meniscal or ligament tears communicating with the joint (e.g., Baker’s cyst communicating with knee)
• Repetitive microtrauma and degenerative joint disease
• Chronic inflammatory conditions (rheumatoid arthritis) producing large effusions that eventually rupture a weak capsule
• Iatrogenic causes (surgical drains, needle aspiration with persistent tract)

Risk Factors

• Recent joint surgery (knee, shoulder, hip)
• Major trauma or penetrating injuries around a joint
• Active inflammatory arthritis or severe osteoarthritis
• Use of anticoagulants (may enlarge effusions)
• Poor wound healing (diabetes, smoking, malnutrition)
• Prior joint injections or repeated aspirations at the same site

Complications

• Recurrent joint effusion and persistent swelling
• Secondary infection (septic arthritis or wound infection)
• Formation of sinus tracts or chronic draining wounds
• Soft-tissue damage or decreased joint function due to prolonged leakage
• Need for repeated procedures or revision surgery
• Delayed rehabilitation and prolonged recovery after joint surgery

Prevention

• Meticulous surgical technique and secure wound closure after joint operations
• Timely control of postoperative bleeding and effusion (drain management when indicated)
• Good glycemic control, smoking cessation, and nutrition to improve wound healing
• Proper protection after acute joint trauma and early orthopedic assessment
• Prompt treatment of large joint effusions (aspiration + appropriate therapy) in inflammatory disease to avoid capsule rupture
• Use of compression and immobilization when clinically appropriate after injury

Treatment Options in Korea

1. Diagnosis

• Clinical exam (inspection for drainage, palpation for fluctuant collections)
• Ultrasound: quick bedside assessment of fluid collections and guidance for aspiration
• MRI: gold standard for detecting capsular tears, communicating cysts, and intra-articular pathology
• Arthrocentesis: aspiration of fluid for analysis (clarity, cell count, crystals, culture)
• Wound swab & culture if drainage present to rule out infection
• Lab tests: CBC, CRP, ESR when infection suspected

2. Conservative Management

• Compression, rest, elevation and activity modification for small, non-infected leaks
• Rehabilitation: targeted physiotherapy to reduce joint stress and restore strength/ROM
• Repeat aspiration for symptomatic effusion (with sterile technique)
• Temporary immobilization (splint, brace) to allow capsular healing in selected cases

3. Medical Treatment

• Antibiotics when bacterial infection is confirmed or strongly suspected (guided by cultures)
• Anti-inflammatories (NSAIDs) and intra-articular corticosteroid in select inflammatory situations (with caution if leak/tracking present)
• Management of underlying systemic disease (e.g., disease-modifying drugs for rheumatoid arthritis)

4. Interventional & Surgical Options

• Image-guided aspiration + sclerotherapy: for some recurrent cystic collections (limited indications)
• Arthroscopic repair: treat meniscal, labral, or capsular tears and close the communication—minimally invasive and commonly used in Korea’s orthopedic centers
• Excision of synovial cyst / ganglion and closure of the joint communication when present
• Primary wound revision and layered closure for postoperative wound leaks; may include negative-pressure wound therapy (VAC) for persistent drainage
• Revision arthroplasty or debridement if prosthetic joint involvement or infection is present
• Placement/removal of drains and management in hospital settings when needed