Category: Surgery

HyProCure is a minimally invasive surgical option for selected patients with symptomatic flat feet (pes planus), aimed at correcting pathological talotarsal joint motion rather than simply supporting the arch externally. It involves placing a titanium stent into the sinus tarsi to stabilise the subtalar joint, with the goal of improving alignment, reducing pain, and enhancing function while preserving joint motion.

Pathomechanics of flat feet and treatment rationale

Symptomatic flat feet are often associated with excessive or prolonged pronation driven by instability at the subtalar or talotarsal joint rather than just “low arches” in isolation. When the talus excessively plantarflexes and adducts on the calcaneus, the medial longitudinal arch collapses, the heel everts, and the forefoot abducts, altering the kinetic chain through the foot, ankle, knee, hip, and lower back. This can contribute to plantar fasciopathy, posterior tibial tendon overload, medial knee stress, and compensatory proximal symptoms, even though many flat feet remain asymptomatic.

Conservative management—such as custom orthoses, physical therapy, and footwear modification—aims to control pronation and redistribute load but does not change the underlying joint structure. For patients who remain symptomatic despite appropriate conservative care, surgical options range from osteotomies and tendon procedures to subtalar arthroereisis, of which HyProCure is a specific extra‑osseous talotarsal stabilisation (EOTTS) system.

Surgical technique and mechanism of action

HyProCure uses a small, threaded titanium stent inserted into the sinus tarsi, the naturally occurring canal between talus and calcaneus, via a small incision on the lateral aspect of the foot. The device sits extra‑osseously in this space, so there is no drilling or cutting of bone, and the surrounding joint surfaces remain intact. Functionally, the implant acts like a “doorstop” to excessive subtalar motion, limiting the pathologic pronatory excursion that allows the talus to collapse medially and the arch to flatten, while still permitting physiological inversion–eversion.

Once placed, the stent immediately realigns and stabilises the hindfoot, bringing the talus back over the calcaneus and improving the orientation of the ankle and midfoot. This restores a more normal heel‑to‑toe progression, improves the timing and magnitude of pronation–supination during gait, and can rebalance ground reaction forces through the medial and lateral columns. Because bone is not cut, the surgery is typically performed as a day procedure, often under local or regional anaesthesia, and the implant is designed as a long‑term or permanent solution but can be removed if necessary.

Indications, patient selection, and postoperative course

HyProCure is generally considered for patients with flexible, symptomatic pes planus or overpronation in whom conservative measures have failed, including both children and adults. In paediatric patients, it is often positioned as an intermediate option when orthoses are insufficient yet full reconstructive surgery would be disproportionately invasive. Adults with chronic pain in the feet, ankles, knees, or lower back related to talotarsal malalignment may also benefit, provided that the deformity is flexible and there is no advanced degenerative joint disease or rigid flatfoot.

Postoperatively, protocols vary, but patients typically weightbear in a protective boot shortly after surgery, transitioning to normal shoes within weeks as swelling resolves and gait adapts. There is usually a short period of altered walking as the neuromuscular system adjusts to the corrected alignment, with full adaptation commonly reported over the first year. Many patients experience improved tolerance for walking, running, and jumping as load distribution normalises and painful overuse of soft tissues reduces.

Outcomes and benefits

Published clinical and industry-reported data suggest high success and satisfaction rates with HyProCure for flatfoot deformity and talotarsal instability. Reports describe approximately 94–95 percent success in achieving durable correction and symptom relief, with over 97 percent of patients rating outcomes as good or excellent at around one year post‑procedure. The realignment of the subtalar joint reduces abnormal stresses not only in the foot but along the kinetic chain, and many patients report reductions in pain at the knees, hips, and lower back together with improved mobility and quality of life.

An important advantage is that HyProCure aims to treat the underlying structural cause of hyperpronation rather than compensating for it with external devices, potentially removing or reducing the need for long‑term orthotic use. The procedure preserves joint motion, avoids bone cuts, and is considered minimally invasive, which may lead to shorter operative times, less soft tissue disruption, and quicker recovery compared with traditional osteotomies. Furthermore, the implant is removable, and removal does not necessarily lead to loss of all correction, offering a degree of reversibility if complications or intolerance occur.

Risks, complications, and limitations

Despite these benefits, HyProCure is not without risk, and complication rates differ markedly between children and adults. In a 2024 clinical study on flatfoot patients in China, overall complication incidence was reported at about 10.6 percent, but only 5.1 percent in children and adolescents compared with 28.8 percent in adults. Documented complications include sinus tarsi pain, peroneal muscle spasm, increased tension in the Achilles–triceps surae complex, and reduced muscle strength, sometimes necessitating implant removal.

The same study reported overall implant removal rates of about 4.4 percent, with just over 1 percent in children and approximately 15 percent in adults, underscoring the higher risk profile in mature, stiffer feet. Persistent sinus tarsi pain is a leading indication for removal and may relate to device size, positioning, or patient-specific anatomy. Flat feet themselves are often asymptomatic, so careful selection is essential to ensure that the patient’s symptoms actually arise from talotarsal malalignment and not from other pathologies; otherwise, expectations may not be met despite technically successful surgery.

HyProCure is also limited in rigid deformities, advanced arthritis, or cases where significant soft tissue reconstruction or bony realignment is required, in which case osteotomies or fusions may be more appropriate. As with any implant-based procedure, long‑term outcomes depend on factors such as body weight, activity level, neuromuscular control, and adherence to rehabilitation, and there is still ongoing research to refine patient selection criteria and implant sizing strategies.

Taken together, HyProCure represents a targeted subtalar arthroereisis option that can offer meaningful structural correction and symptom relief for well‑selected patients with flexible, symptomatic flat feet who have not responded to conservative therapy. For clinicians, it occupies a niche between orthotic management and more invasive reconstructive surgery, with the advantages of a minimally invasive approach and reversible implant, but it requires thoughtful assessment of biomechanics, comorbidities, and patient expectations to optimise outcomes and minimise complications, particularly in adults.

The Chevron osteotomy is a widely performed surgical procedure used to correct mild to moderate cases of hallux valgus, commonly known as bunions.

Understanding Hallux Valgus

Hallux valgus is a progressive deformity characterized by a lateral deviation of the big toe (hallux) and a medial deviation of the first metatarsal bone. This misalignment forms a prominent bony bump at the base of the big toe, leading to pain, discomfort, and difficulty with footwear. Bunions can arise from genetic predisposition, wearing narrow shoes, biomechanical abnormalities, or inflammatory diseases. Over time, untreated bunions can cause calluses, bursitis, and osteoarthritis within the first metatarsophalangeal (MTP) joint.

Conservative therapies—such as orthotics, shoe modification, padding, and anti-inflammatory medications—aim to alleviate discomfort but cannot correct the deformity. When non-surgical methods fail, surgical correction becomes necessary. Among the several surgical options, the Chevron osteotomy (also known as the Austin bunionectomy) remains one of the most common and effective for mild to moderate deformities.

What is a Chevron Osteotomy?

The Chevron osteotomy, first introduced in 1968, involves creating a V-shaped (chevron) cut at the distal end of the first metatarsal bone—the long bone leading to the big toe. The apex of the “V” typically points toward the toes, and the arms extend into the bone shaft at approximately a 60-degree angle. The surgeon then shifts the head of the metatarsal laterally (toward the outer side of the foot) to realign the big toe into a more anatomically correct position. This realignment corrects the abnormal angle between the first and second metatarsals, thereby straightening the toe.

After the cut, surgeons often secure the repositioned bone fragment using small screws or pins—a method known as internal fixation—to hold the bone stable during healing. In some older versions, fixation was not always used, but modern techniques usually include hardware to reduce recurrence risk and allow early mobility

Indications and Patient Selection

The Chevron osteotomy is suitable for individuals with mild to moderate hallux valgus deformities. The procedure is most effective for younger patients or those without significant joint arthritis. It works best when the first MTP joint remains congruent—that is, the joint surfaces still align well despite the bunion angle. The surgery is contraindicated in severe cases of bunion deformity, marked arthritis, or if the joint is incongruent with tight adductor muscles or restrictive ligaments.

Patients typically undergo surgery after conservative treatments fail to relieve symptoms. It is not advisable if the bunion is painless or purely cosmetic. Surgeons also avoid performing it in patients with poor blood flow, active infections, or uncontrolled diabetes because of higher complication risks.​

The Surgical Procedure

The procedure is commonly performed on an outpatient basis under local, regional, or general anesthesia. A small incision is made on the medial side of the big toe joint. The surgeon exposes the head of the first metatarsal, trims any bony prominence causing the lump (exostectomy), and performs the Chevron cut. Once the distal fragment is shifted laterally, the toe is realigned. Small screws, wires, or sometimes bioabsorbable pins are inserted for fixation. Occasionally, soft-tissue adjustments around the joint accompany the osteotomy—especially release of the tight lateral capsule or tightening of the medial structures—to achieve optimal balance.

Some surgeons combine the Chevron osteotomy with other minor procedures, such as the Akin osteotomy, which involves a small wedge cut in the proximal phalanx of the great toe to fine-tune the alignment. This combined Chevron-Akin approach enhances correction and stability, particularly in patients with greater angular deformities

Modern Techniques and Innovations

Advancements in surgical instrumentation have made modern Chevron osteotomies less invasive. Minimally invasive or percutaneous techniques now allow surgery through smaller incisions, using specialized burrs under fluoroscopic guidance. This approach minimizes soft-tissue trauma, reduces pain and swelling, and leads to faster recovery. Internal fixation has also evolved, with surgeons employing low-profile screws and even bioabsorbable implants to maintain alignment during healing.

Benefits of the Chevron Osteotomy

The Chevron osteotomy provides multiple benefits for appropriate patients. The primary goals are pain relief and improved toe alignment. By restoring the normal mechanics of the first MTP joint, it allows better weight distribution during walking. The procedure also corrects cosmetic deformity, making footwear more comfortable. Studies show that most patients experience significant improvement in their intermetatarsal and hallux valgus angles, providing long-lasting results with high satisfaction rates.

Since it is a relatively stable osteotomy, early mobilization is often encouraged, reducing stiffness and promoting bone healing. The shape of the V-cut offers natural mechanical stability, and internal fixation further enhances this advantage. Compared to more proximal or complex osteotomies, the Chevron method carries less risk of metatarsal shortening, transfer metatarsalgia, or nonunion.

Risks and Complications

Like any surgery, the Chevron osteotomy carries some risks. Common complications include postoperative swelling, stiffness, recurrence of the deformity, or overcorrection (hallux varus). Occasionally, hardware irritation can occur, necessitating screw removal. There is also a risk of delayed union if fixation is inadequate or if the patient resumes weight-bearing too early. Nerve injury around the incision site can cause temporary numbness, and in rare cases, infection or wound healing problems may occur.

Failure to adhere to postoperative protocols—such as using supportive footwear or avoiding premature activity—can jeopardize the surgical outcome. The skill of the surgeon and the suitability of the patient’s anatomy also play major roles in success rates

Postoperative Care and Recovery

Following surgery, the foot is typically bandaged and protected with a specialized postoperative shoe that allows limited weight-bearing. Elevation and ice minimize swelling during the initial recovery phase. Patients are usually advised to avoid full-foot loading for the first few weeks. Sutures are removed after about two weeks, and light walking in the surgical shoe follows. Physical therapy may begin after four to six weeks to improve joint mobility and strength.

Full recovery—including return to normal shoes and activities—typically takes about two to three months, though some swelling can persist longer. Radiographic evaluation ensures proper healing and correction. Most patients report reduced pain, improved foot function, and satisfaction with cosmetic results.

Comparison with Other Osteotomies

Other bunion surgeries include the Scarf, Akin, proximal Chevron, and Lapidus osteotomies. Compared with these, the Chevron approach is simpler and less invasive, with a faster recovery for mild deformities. However, it offers limited correction potential for severe hallux valgus, where more extensive bone rearrangement may be necessary. Studies comparing the Chevron to distal oblique osteotomies have found comparable radiographic and patient satisfaction outcomes, confirming that the Chevron remains a reliable standard for mild to moderate cases.

The Chevron osteotomy represents a time-tested and refined surgical technique for the management of mild to moderate hallux valgus deformities. It effectively straightens the big toe, relieves pain, and improves foot function with minimal downtime and low complication rates. While not suitable for every patient, especially those with severe deformities or joint arthritis, it remains the gold standard procedure for many surgeons worldwide. As technology advances, minimally invasive Chevron techniques promise even better outcomes, making this operation both efficient and patient-friendly

The Austin Bunionectomy is a well-established surgical procedure designed to correct painful bunion deformities, particularly those classified as mild to moderate hallux valgus. Since its introduction in the late 1970s, this technique has achieved widespread popularity in both podiatric and orthopedic circles due to its biomechanical effectiveness, relative safety, and favorable patient outcomes.

Overview and Indications

The Austin Bunionectomy, sometimes referred to as the Chevron osteotomy, involves a precise V-shaped bone cut (osteotomy) made at the distal end of the first metatarsal. This procedure realigns the first metatarsal head, correcting the angle between the first and second metatarsal bones, thus reducing the characteristic bump of a bunion and straightening the big toe. It is particularly indicated for individuals with a moderate degree of bunion deformity (typically an intermetatarsal angle of less than 16 degrees) and those without significant degenerative changes in the big toe joint.

Surgical Technique

On the day of surgery, the patient is generally given anesthesia through IV sedation or general anesthesia, and a local anesthetic is used for additional pain control. The surgeon makes an incision over the affected joint to access the bunion and underlying bone structures. The first step is often the removal of the hypertrophic bone (the bunion “bump”) from the side of the first metatarsal head.

A V-shaped (“Chevron”) osteotomy is then performed through the metatarsal head. The apex of this cut is at the center of the metatarsal head with arms extending dorsally and plantarly. The head of the metatarsal is shifted laterally toward the second toe, correcting the deformity. The repositioned bone is stabilized with surgical hardware, most commonly stainless steel screws, which remain in place permanently unless complications arise. Occasionally, pins or staples are used, and some surgeons alternate between different fixation devices based on patient and procedural factors.

Following bone work, associated soft tissue structures such as tendons and the joint capsule may be tightened or rebalanced as needed, helping to maintain toe alignment and function.

Postoperative Care and Recovery

Immediately after surgery, the foot is protected with a bandage and a specialized surgical shoe or rigid sandal. Patients are encouraged to keep the foot elevated and rest for the first week, with weight-bearing typically permitted using the surgical shoe. Casts, crutches, or walkers are not usually required. Sutures are usually removed around the second week post-surgery, once initial healing is underway.

Over the following weeks, the bandage is replaced with an ace wrap and a spacer is placed between the first and second toes to maintain alignment. Progress is monitored by clinical examination and periodic x-rays. At around four weeks, many patients can transition into a regular walking shoe, although swelling and discomfort may persist and full bone healing continues for up to eight weeks or longer. Most individuals return to normal activity, including low-impact exercise, in 8–10 weeks, although it can take up to three months for a full recovery.

Advantages of the Procedure

• The Austin Bunionectomy preserves the joint and allows for the correction of mild to moderate bunion deformities without extensive joint dissection
• Most patients are not immobilized in a cast and can begin bearing weight immediately after surgery using a surgical shoe.
• The operation is technically straightforward for trained foot surgeons and results in relatively rapid recovery, returning many patients to regular footwear and activities by six weeks postoperatively.

Limitations and Complications

While the Austin Bunionectomy is successful for a majority of patients, it has certain limitations:

• It is not suitable for patients with severe bunions (large intermetatarsal angles) or with significant instability and arthritis of the toe joint.
• There is a recurrence rate—in the range of 5–8%—where the bunion may return, necessitating further treatment for some patients.
• As with all surgeries, there are general risks of infection, delayed bone healing, or discomfort from retained hardware, but complication rates are generally low.

Clinical Outcomes

Long-term studies demonstrate good to excellent results for the majority of patients undergoing the Austin Bunionectomy, particularly when patient selection is appropriate and postoperative instructions are carefully followed. Patients report reductions in pain, improved function, and satisfaction with cosmetic appearance following the surgery, making it a mainstay procedure for bunion correction.

The Austin Bunionectomy remains a reliable, joint-preserving, and biomechanically sound surgical solution for mild to moderate bunion deformities. Its combination of effectiveness, safety, and relatively swift recovery has made it one of the most frequently performed bunion procedures worldwide. Proper patient selection, skilled surgical execution, and thorough postoperative care are crucial for optimal outcomes and enduring relief from bunion pain and dysfunction.