Insertional Achilles Tendonitis: What Is It and How Can I Treat It?
Pain at the back of your heel can make everyday activities such as walking, exercising, climbing stairs, and wearing certain shoes difficult. One common cause of this type of pain is insertional Achilles tendinopathy, also commonly called insertional Achilles tendonitis.
This article explains what insertional Achilles tendonitis is, why it occurs, how it is treated without surgery, and how a Zadek osteotomy can help patients with chronic Achilles tendon pain.
What Is Insertional Achilles Tendonitis?
Insertional Achilles tendinopathy (IAT) is a condition affecting the lower portion of the Achilles tendon where it attaches to the back of the heel bone, or calcaneus. It is different from mid-portion Achilles tendinopathy, which occurs farther up the tendon. Patients with IAT commonly experience pain, tenderness, and stiffness at the back of the heel. Symptoms are often worse with physical activity and may be particularly noticeable when walking uphill, climbing stairs, running, or after periods of rest.
Despite the commonly used term "Achilles tendonitis," IAT is generally considered a degenerative tendinopathy rather than simply an inflammatory condition. Changes can include degeneration of the tendon fibers, thickening of the tendon, calcification within or around the tendon insertion, and formation of bone spurs.
Some patients also have a Haglund's deformity, which is a prominence of bone at the upper-back portion of the heel. This prominence can contribute to compression and irritation of the Achilles tendon, particularly when the ankle moves upward. However, not everyone with a Haglund's deformity develops Achilles pain, and not every patient with insertional Achilles tendinopathy has a Haglund's deformity.
Why Do You Get Insertional Achilles Tendonitis?
There is not one single cause of insertional Achilles tendonitis. It is usually the result of a combination of factors that increase the stress placed on the Achilles tendon over time. Repetitive activities such as running, jumping, or walking uphill can increase the load on the tendon. Sudden changes in activity level or training can also contribute.
Age is another important factor. IAT becomes more common as we get older because the Achilles tendon becomes less capable of tolerating repetitive loading and may undergo degenerative changes. Other factors associated with Achilles tendinopathy include increased body weight, diabetes, certain foot and lower-extremity mechanics, previous tendon problems, and reduced calf strength or flexibility.
The mechanics of the back of the heel can also play a role. At the Achilles insertion, the tendon is exposed to both tension and compression. Activities that place the ankle into significant dorsiflexion, such as uphill running, can increase compression between the Achilles tendon and calcaneus. A prominent posterior heel bone can further contribute to this mechanical irritation.
What Are the Symptoms of Insertional Achilles Tendonitis?
Common symptoms include:
Pain at the back of the heel
Achilles tendon stiffness, particularly after resting
Tenderness where the Achilles attaches to the heel
Swelling or thickening around the Achilles insertion
A noticeable bump at the back of the heel
Pain when wearing certain shoes
Pain with running, jumping, stairs, or uphill walking
Decreased ability to participate in sports or exercise
The diagnosis is generally made through a combination of your medical history and physical examination. X-rays can show bone spurs, calcifications, and the shape of the heel bone, while ultrasound or MRI can provide additional information about the Achilles tendon and surrounding soft tissues.
How Is Insertional Achilles Tendonitis Treated Without Surgery?
Non-surgical treatment is successful approximately 70% of the time, so conservative treatment is generally the first step for patients with insertional Achilles tendonitis. Treatment may include modifying activities that aggravate the tendon, physical therapy, progressive calf and Achilles strengthening, footwear modification, heel lifts, orthotics when appropriate, and medications for pain when medically appropriate. Exercise has some of the strongest evidence among non-surgical treatments for IAT, while extracorporeal shockwave therapy (ESWT) has also been studied as a treatment option.
It is important to put the 70% figure into context. Historical literature has often cited non-surgical success rates in the 50–70% range, while a 2022 study of 137 ankles found a higher success rate of 78.6% with modern non-operative treatment. A separate study reported a success rate of just over 80%. Therefore, the likelihood of success varies depending on the patient, severity of disease, treatment program, and definition of "success."
Physical therapy is particularly important because the goal is not simply to decrease pain. A properly designed rehabilitation program gradually improves the Achilles tendon's ability to tolerate load. For insertional Achilles tendinopathy, exercises may be modified to avoid excessive compression of the tendon against the heel bone.
When Is Surgery Considered?
Most patients should have an appropriate trial of non-surgical treatment before considering surgery. If pain continues despite several months of appropriate treatment and continues to interfere with daily activities, exercise, work, or quality of life, surgery may become an option.
Traditional surgery for insertional Achilles tendonitis may involve removing damaged portions of the Achilles tendon, removing bone spurs or a Haglund's deformity, and, when necessary, detaching and repairing part of the Achilles tendon.
Although these procedures can be effective, they can also involve a significant amount of soft-tissue work around the back of the heel. Depending on the amount of tendon that needs to be removed, the Achilles may need to be repaired or augmented.
A Zadek osteotomy provides another surgical option for appropriately selected patients.
What Is a Zadek Osteotomy?
A Zadek osteotomy, also known as a dorsal closing-wedge calcaneal osteotomy, is a surgical procedure that changes the shape and position of the heel bone to reduce mechanical stress on the Achilles tendon insertion.
Instead of primarily treating the Achilles tendon by cutting out diseased tendon, the Zadek procedure addresses the mechanics of the heel bone.
During the procedure, a carefully planned wedge of bone is removed from the calcaneus. The heel bone is then closed and repositioned. This changes the position of the Achilles tendon insertion and can reduce the impingement and compression occurring between the tendon and the back of the heel.
One potential advantage of this approach is that the Achilles tendon does not need to be directly detached from the heel bone. The procedure instead changes the position of the calcaneus and Achilles insertion to reduce stress on the tendon.
How Does a Zadek Osteotomy Work?
Think of the Achilles tendon as a strong cable attached to the back of the heel bone.
With insertional Achilles tendonitis, that attachment can experience excessive tension and compression. A prominent portion of the heel bone can contribute to this compression.
A Zadek osteotomy changes the geometry of the heel bone. A dorsal wedge is removed, allowing the calcaneus to shorten and rotate. This moves the Achilles insertion anteriorly and superiorly and is intended to reduce the mechanical impingement and stress at the tendon insertion.
The goal is to create a more favorable environment for the Achilles tendon to heal while preserving the tendon attachment.
Is a Zadek Osteotomy Minimally Invasive?
A Zadek osteotomy can be performed through a minimally invasive or percutaneous approach in appropriately selected patients. Minimally invasive techniques use small incisions and are designed to limit disruption to the soft tissues around the heel.
A 2024 study of patients undergoing percutaneous Zadek osteotomy reported significant improvements in pain and function at a mean follow-up of approximately 3.5 years. The study included 108 procedures, with 104 patients available for outcome analysis.
Minimally invasive surgery is not necessarily appropriate for every patient. The surgical approach depends on the amount of Achilles tendon disease, the anatomy of the heel, associated conditions, and the surgeon's assessment.
What Are the Results of Zadek Osteotomy?
Research on the Zadek osteotomy has shown encouraging results for patients with chronic insertional Achilles tendinopathy who have failed non-surgical treatment.
A 2023 systematic review and meta-analysis evaluated 10 studies involving 232 patients. The researchers found significant improvements in both pain and functional outcome scores following Zadek osteotomy. The reported complications were generally considered minor, with superficial wound infection and sural nerve symptoms among the more commonly reported complications.
Another systematic review evaluated eight retrospective case series and found that the weighted mean VISA-A score improved from 52.7 before surgery to 87.8 after surgery. The American Orthopaedic Foot & Ankle Society score also improved from 56.3 to 92.9.
More recent research specifically evaluating percutaneous Zadek osteotomy has also reported encouraging outcomes. In a series of 104 patients with at least two years of follow-up, the average pain score decreased from 7.7 before surgery to 0.4 after surgery. The overall complication rate was 3.8%, and 98.1% of patients who answered the satisfaction question reported that they were satisfied with their procedure and recovery.
These results are encouraging, but it is important to understand that much of the evidence for Zadek osteotomy consists of retrospective studies and case series. A systematic review noted that there are currently no well-designed randomized controlled trials directly comparing Zadek osteotomy with other surgical treatments for insertional Achilles tendinopathy.
What Is Recovery Like After a Zadek Osteotomy?
Recovery following a Zadek osteotomy involves protecting the heel bone while the osteotomy heals. Our typical postoperative protocol includes approximately 3 weeks of non-weight bearing after surgery. During this period, patients use crutches, a knee scooter, or another assistive device to keep weight off the operative foot.
After the initial 3 weeks, patients generally transition into a walking boot for another 3 weeks. During this phase, patients can progressively increase weight bearing as directed. Range-of-motion exercises can begin during this period, with the goal of restoring ankle mobility while continuing to protect the healing calcaneal osteotomy.
Full weight bearing typically begins around week 5, depending on the patient's healing and clinical evaluation. Physical therapy and a gradual progression of activity can then be used to restore strength, flexibility, balance, and function.
It is important to understand that bone healing takes time, and returning to running, jumping, and other high-impact activities should only occur after adequate healing and rehabilitation. Your recovery timeline may vary depending on your bone healing, overall health, activity level, and how your foot and ankle respond after surgery.
What Are the Risks of a Zadek Osteotomy?
As with any surgical procedure, a Zadek osteotomy has potential risks. These can include infection, nerve irritation, problems with bone healing, painful hardware, blood clots, continued pain, or the need for additional surgery.
In the 2023 systematic review and meta-analysis of 232 patients, 22 complications were reported across the included studies, with superficial wound infection and sural nerve paresthesia among the most common.
In the 2024 study of percutaneous Zadek osteotomy, four complications occurred among 104 patients available for analysis. These included painful hardware, nonunion requiring revision, and a plantar fascia injury.
Your individual risks depend on your medical history, anatomy, surgical technique, and other factors. Your foot and ankle surgeon should discuss the potential benefits and risks with you before surgery.
Is a Zadek Osteotomy Right for You?
A Zadek osteotomy is not the right procedure for every patient with Achilles tendon pain. The decision depends on several factors, including:
The location and severity of your Achilles tendon disease
The amount of tendon degeneration
The shape of your heel bone
The presence of a Haglund's deformity or bone spur
Your activity level
Your overall health
How long you have had symptoms
Your response to non-surgical treatment
Your goals for returning to work, exercise, or sports
Your physician may use X-rays, ultrasound, or MRI to better understand the condition of your Achilles tendon and heel bone.
For some patients, traditional Achilles tendon debridement may be more appropriate. For others, a Zadek osteotomy may offer a way to address the mechanical problem while avoiding direct detachment of the Achilles tendon.
The Bottom Line
Insertional Achilles tendonitis can cause significant pain and interfere with walking, exercise, work, and everyday activities. Fortunately, approximately 70% of patients can improve with non-surgical treatment, although newer research suggests that modern conservative treatment may be successful in an even higher percentage of patients.
When appropriate non-surgical treatment fails, surgery may be considered. A Zadek osteotomy is a modern surgical option for selected patients with chronic insertional Achilles tendinopathy. Rather than primarily removing damaged Achilles tendon, the procedure changes the shape and position of the heel bone to reduce mechanical stress at the Achilles insertion.
Current research demonstrates significant improvements in pain and function following Zadek osteotomy, including encouraging results from minimally invasive techniques. However, most available research is based on observational studies, so patients should discuss whether the procedure is appropriate for their individual condition with an experienced foot and ankle surgeon.
If you have persistent pain at the back of your heel that has not improved with conservative treatment, an evaluation can help determine whether you have insertional Achilles tendinopathy and which treatment options may be appropriate for you.
Greenville's Foot & Ankle Specialists can evaluate your Achilles tendon and discuss both non-surgical and surgical treatment options based on your individual condition.
Medical References
Chimenti RL, Cychosz CC, Hall MM, et al. Current Concepts Review Update: Insertional Achilles Tendinopathy. Foot & Ankle International.
Kedia M, et al. Nonsurgical treatment options for insertional Achilles tendinopathy. Journal of Orthopaedic & Sports Physical Therapy.
Zhang et al. Nonoperative treatment of insertional Achilles tendinopathy: a systematic review. Journal of Orthopaedic Surgery and Research.
Kunkle BF, et al. Success Rate of Non-Operative Treatment of Insertional Achilles Tendinitis. Foot & Ankle Orthopaedics. 2022.
Poutoglidou F, et al. Clinical Outcomes and Complications of the Zadek Calcaneal Osteotomy in Insertional Achilles Tendinopathy: A Systematic Review and Meta-analysis. Foot & Ankle Surgery. 2023.
Black AT, So E, Combs A, Logan D. The Zadek Osteotomy for Surgical Management of Insertional Achilles Tendinopathy: A Systematic Review. Foot & Ankle Specialist. 2023.
Hall SR, Schipper ON, Kaplan JRM, et al. Outcomes After Percutaneous Zadek Osteotomy for Insertional Achilles Tendinopathy. Foot & Ankle Orthopaedics. 2024.
