Tendon pain can be frustrating. Whether it’s a persistent Achilles issue that won’t settle, a sore elbow from repetitive work, or a nagging shoulder problem, chronic tendon injuries – often called tendinopathies – can significantly limit daily activities, sport, and work performance.
While physiotherapy and exercise remain the gold standard treatment for most tendon problems, advances in regenerative medicine have introduced new options for people whose symptoms persist despite conservative care. One of these emerging treatments is Autologous Tenocyte Implantation (ATI).
In this blog, we’ll explain what ATI is, how it works, who it may help, and why rehabilitation remains essential for long-term tendon recovery.
Understanding Tendinopathy
Before discussing ATI, it helps to understand what happens when a tendon becomes injured.
Tendons are strong bands of connective tissue that attach muscle to bone, allowing movement and force transfer. They are primarily made of collagen fibres, which give them strength and elasticity.
Tendinopathy typically develops when a tendon experiences repeated overload without enough recovery time. Over time, this can lead to:
- Breakdown of collagen fibres
- Reduced tendon strength
- Changes in tendon structure
- Pain and reduced function
Unlike an acute tear, many chronic tendon problems involve degeneration rather than inflammation, which is why they can be slow to heal.
Common areas affected include:
- Elbow (tennis elbow – common extensor tendon)
- Knee (patellar tendon)
- Achilles tendon in the ankle
- Hip and buttock tendons (gluteal or hamstring tendons)
- Shoulder tendons such as the supraspinatus
For most people, structured exercise programs – especially eccentric strengthening – are highly effective. However, in long-standing or severe cases, additional treatment options may be considered.
What Is Autologous Tenocyte Implantation (ATI)?
Autologous Tenocyte Implantation (ATI) is a regenerative medical procedure designed to help repair damaged tendon tissue using the patient’s own cells.
The word autologous simply means coming from your own body.
In this procedure:
- Healthy tendon cells are collected from the patient.
- These cells are grown and multiplied in a laboratory.
- The expanded cells are then injected back into the injured tendon.
These cells, called tenocytes, are responsible for producing collagen and healthy tendon tissue. By introducing more tenocytes into the injured area, ATI aims to:
- Improve tendon structure
- Strengthen the tendon
- Support tissue regeneration
- Reduce pain and improve function
Because the cells come from the patient’s own body, the risk of rejection or adverse reaction is extremely low.
Which Tendon Injuries Can ATI Treat?
ATI may be considered for chronic or degenerative tendinopathies that have not responded to standard treatments.
The most commonly treated areas include:
- Tennis elbow (lateral epicondylalgia)
- Patellar tendinopathy (jumper’s knee)
- Achilles tendinopathy
- Gluteal tendinopathy around the hip
- Hamstring tendon injuries
- Rotator cuff tendons, particularly the supraspinatus
However, in theory any tendon in the body can be treated, depending on the nature of the injury and the advice of a specialist.
How the ATI Procedure Works
ATI is a two-stage procedure, both performed using ultrasound guidance to ensure precision.
The good news is that both stages are relatively quick and well tolerated, typically taking less than 30 minutes each.
Stage 1: Harvesting Healthy Tendon Cells
The first step involves collecting a small sample of healthy tendon tissue.
Typically, this sample is taken from the patellar tendon, located just below the kneecap. This tendon is often chosen because it is:
- Easily accessible
- Large enough to safely obtain a small sample
- Able to recover quickly from the biopsy
Using ultrasound guidance, a specialist uses a biopsy needle to collect two small core samples of tendon tissue.
At the same time, a small blood sample is taken from the arm. This blood is used to create serum, which helps support the growth of the tendon cells in the laboratory.
Stage 2: Growing the Tenocytes
Once the tissue samples are collected, they are sent to a laboratory where the tenocytes are isolated and cultured.
Over the next 4-6 weeks, the cells multiply and grow in the patient’s own serum.
During this process, the laboratory typically produces millions of healthy tendon cells – often around five million tenocytes.
These expanded cells are then prepared for the second stage of the treatment.
Stage 3: Injection into the Injured Tendon
The final stage involves injecting the cultured tenocytes into the damaged tendon.
Using ultrasound guidance, the specialist carefully places the cells into the area of greatest tendon abnormality.
This targeted injection aims to help stimulate collagen production and tendon regeneration, supporting the healing process.
What Happens After the Injection?
Recovery after ATI involves a structured rehabilitation program, which plays a crucial role in the overall success of the treatment.
Typical recovery stages include:
First 48 hours
- Rest and protection of the treated area
First two weeks
- Gentle stretching exercises
After two weeks
- A progressive rehabilitation program begins
Rehabilitation usually focuses on eccentric strengthening exercises, which are widely recognised as one of the most effective treatments for tendon injuries.
Working with a physiotherapist or sports doctor helps ensure exercises are progressed safely and appropriately.
When Will Results Be Noticed?
Unlike treatments that aim to provide immediate pain relief, ATI works by stimulating tissue regeneration.
Because tendons heal slowly, improvements usually occur gradually over several weeks to months.
This timeframe reflects the natural process of:
- Tendon cell growth
- Collagen production
- Tissue remodelling
- Strength recovery
Patience and adherence to rehabilitation are important to achieve the best outcomes.
What Does the Research Say?
Research into ATI is ongoing.
Studies examining Autologous Tenocyte Injection for chronic tendinopathies suggest it may help improve pain and function in certain patients. However, current evidence is still evolving, and there is not yet universal consensus regarding its effectiveness.
For this reason, ATI is often considered one option within a broader treatment approach, rather than a first-line therapy.
Exercise-based rehabilitation remains one of the most evidence-supported treatments for tendinopathy.
The Role of Physiotherapy in Tendon Recovery
Even when regenerative procedures like ATI are used, physiotherapy remains essential.
A physiotherapist can help with:
- Accurate diagnosis of tendon problems
- Load management and activity modification
- Progressive strengthening programs
- Eccentric tendon exercises
- Movement and technique correction
- Return-to-sport or return-to-work planning
In many cases, targeted rehabilitation alone can successfully resolve tendon pain.
When Should You Seek Help for Tendon Pain?
You should consider seeing a physiotherapist if you experience:
- Persistent tendon pain lasting more than a few weeks
- Pain during or after exercise
- Reduced strength or function
- Difficulty performing work, sport, or daily activities
- Recurring tendon injuries
Early assessment can help prevent tendon problems from becoming long-term or chronic.
Final Thoughts
Autologous Tenocyte Implantation is an innovative regenerative treatment that aims to restore tendon health by using the body’s own cells to support tissue repair.
While it may be an option for some people with persistent tendinopathy, most tendon injuries respond well to physiotherapy, load management, and progressive strengthening programs.
Understanding your condition and following the right rehabilitation plan are key to getting back to pain-free movement and activity.
Need Help with Tendon Pain?
If you’re experiencing ongoing tendon pain in your shoulder, elbow, hip, knee, or Achilles, the team at Logan Physio can help.
Our physiotherapists can assess your injury, guide you through evidence-based rehabilitation, and help you return to the activities you enjoy.
📅 Book an appointment today and take the first step toward stronger, healthier tendons.
