Flatfoot, or pes planus, is a common musculoskeletal condition affecting millions of individuals, from young children to adults. While many cases are asymptomatic, pathological flatfoot can lead to a debilitating cascade of symptoms including pain, fatigue, postural issues, and progressive joint degeneration. Traditional treatment algorithms have long oscillated between conservative management (orthotics, physical therapy) and highly invasive reconstructive surgeries (osteotomies, fusions) with little middle ground. The advent of the HyProCure implant represents a revolutionary paradigm shift, offering a minimally invasive, extra-articular, and biomechanically sound solution that effectively addresses the root cause of flexible flatfoot deformity.

Understanding the Pathomechanics of Flexible Flatfoot
To appreciate the innovation of HyProCure, one must first understand the anatomical failure it corrects. A stable, aligned foot relies on a key joint complex: the talotarsal joint (talus, navicular, and calcaneus). The keystone of this arch is the talus, which should be securely seated on the sustentaculum tali of the calcaneus. In flexible flatfoot, a condition known as talotarsal dislocation or excessively pronated foot occurs. Here, the supporting ligaments fail, allowing the talus to subluxate anterolaterally and the calcaneus to evert. This collapse of the medial longitudinal arch is not merely a “flat” appearance; it is a three-dimensional malalignment that disrupts the entire kinetic chain, causing abnormal stress on the ankles, knees, hips, and spine. Traditional soft tissue procedures often fail, as they do not address this bony malalignment, while calcaneal osteotomies and arthrodeses, though sometimes necessary for rigid deformities, are overly destructive for the flexible condition.

The HyProCure Principle: A Minimally Invasive Stabilizer
The HyProCure device, a self-expanding, cylindrical titanium stent, is engineered to correct talotarsal dislocation at its source. The procedure targets the sinus tarsi, a naturally occurring canal between the talus and calcaneus. In a stable foot, the contents of this canal (the interosseous ligament) act as a proprioceptive and stabilizer. In flatfoot, this ligament is stretched and incompetent.

The HyProCure technique involves a small (<2 cm) incision on the outside of the foot. Under fluoroscopic guidance, the surgeon prepares the sinus tarsi and inserts the compact device. Once in position, the device expands to its pre-determined size, acting as a physical block to the pathological frontal plane motion of the calcaneus and transverse plane motion of the talus. It does not fuse any joints; rather, it realigns and stabilizes the talotarsal joint complex, allowing for normal, pain-free physiological motion within a corrected range. This is the core of its genius: it is extra-articular (outside the joint cavity), minimally invasive, and biomechanically specific.

Comparative Advantages Over Traditional Approaches
The benefits of HyProCure become starkly clear when contrasted with traditional options.

1. Versus Conservative Care: Custom orthotics are the mainstay of non-surgical management. However, they are a palliative, not a corrective, solution. They support the arch from below but do not reduce the talotarsal dislocation. They must be worn indefinitely, can be cumbersome, and do not halt the progression of deformity or the compensatory issues upstream. HyProCure, by contrast, offers a permanent, internal correction, freeing the patient from lifelong dependence on external devices.
2. Versus Major Reconstructive Surgery: Procedures like calcaneal osteotomies (cutting and shifting the heel bone) or arthrodesis (fusing joints) are irreversible, involve significant bone work, prolonged non-weight bearing (often 6-12 weeks), and high rates of hardware-related complications. They alter the foot’s architecture in a dramatic and non-physiological way. HyProCure surgery is typically performed in under 30 minutes, with most patients walking within days in a surgical shoe and returning to regular shoes in 2-4 weeks. It preserves all joint motion and is inherently reversible—the device can be removed if necessary, leaving the native anatomy intact.

Clinical Applications and Outcomes
HyProCure is indicated for symptomatic flexible flatfoot in both pediatric and adult populations where conservative care has failed. In children, it can be performed as early as age 3-4, potentially guiding proper skeletal development and preventing a lifetime of musculoskeletal issues. For adults, it addresses acquired posterior tibial tendon dysfunction (PTTD) in its early stages by removing the deforming force on the tendon, often preventing the need for tendon transfers or more drastic reconstructions.

Reported outcomes are consistently favorable. Studies and extensive clinical experience show high patient satisfaction rates (exceeding 90%), significant improvements in pain scores, and restoration of radiographic parameters (e.g., talonavicular coverage, calcaneal pitch). Patients report improved stability, endurance, and alignment. The low complication rate, dominated by minor issues like sinus tarsi discomfort (often manageable) or rare cases of device malposition, compares favorably to the significant morbidity profile of traditional flatfoot reconstructions.

Critical Considerations and the Future
HyProCure is not a panacea. Patient selection is paramount. It is contraindicated for rigid flatfoot, arthritic joints, or significant hindfoot valgus that requires bony correction. It is a motion-preserving stabilizer, not a solution for fixed deformity. The surgeon’s experience with the precise technique and understanding of subtalar biomechanics is critical for success.

The emergence of HyProCure signifies a broader trend in orthopedics toward subtalarthroereisis—the blocking of excessive motion—and biologic, minimally invasive solutions. It challenges decades-old surgical dogmas, proving that less can indeed be more. By offering a low-morbidity, high-reward option, it expands the treatment pyramid, providing a definitive corrective step before resorting to major reconstruction.

The HyProCure implant represents a transformative advance in foot and ankle surgery. By directly targeting the pathological talotarsal dislocation through a minimally invasive, extra-articular approach, it provides a permanent, anatomical correction that conservative care cannot achieve, while avoiding the trauma and irreversibility of major surgery. For the appropriate patient with symptomatic flexible flatfoot, HyProCure is more than just a new device; it is a logical, elegant, and patient-centric solution that realigns not just the talus and calcaneus, but the entire philosophy of how we treat this common and impactful condition. It stands as a testament to the power of innovative engineering applied to profound biomechanical understanding.

Hallux valgus, commonly known as a bunion, is a complex and often painful deformity of the forefoot characterized by the lateral deviation of the great toe (hallux) and medial deviation of the first metatarsal. This progressive condition can lead to significant discomfort, difficulty with footwear, and a diminished quality of life. While conservative management offers relief for some, surgical intervention remains the definitive solution for correcting the underlying structural pathology. Among the plethora of surgical techniques developed over the decades, the Chevron osteotomy has emerged as a cornerstone procedure, renowned for its stability, versatility, and predictable outcomes for a specific and common patient population. This essay will explore the anatomical basis of hallux valgus, the rationale and technique of the Chevron osteotomy, its indications and limitations, and its enduring role in the foot and ankle surgeon’s armamentarium.

The pathoanatomy of hallux valgus is multifactorial, involving a biomechanical breakdown at the first metatarsophalangeal joint (MTPJ). The deformity is not simply a “bump” on the side of the foot; rather, it is a tri-planar deformity consisting of lateral deviation of the proximal phalanx (valgus), medial deviation of the first metatarsal (primus varus), and, frequently, rotation (pronation) of the hallux. This misalignment places abnormal tensile forces on the medial soft tissues and compressive forces on the lateral structures, leading to the prominent, inflamed medial eminence colloquially known as the bunion. Over time, the medial joint capsule becomes stretched, the lateral structures contracted, and the sesamoid apparatus, which is vital for weight-bearing, becomes subluxed laterally. The goal of any corrective surgery is to realign the first ray, restore joint congruity, and rebalance the soft tissues, thereby alleviating pain and restoring function.

The Chevron osteotomy, first described by Corless in 1976 as a modification of an earlier procedure, is a distal first metatarsal osteotomy distinguished by its unique V-shaped cut. The name “chevron” is derived from the military insignia and heraldic symbol, reflecting the inverted ‘V’ configuration of the bone cut. The primary biomechanical principle behind this osteotomy is its inherent stability. The shape of the cut creates a large, cancellous bone surface area for healing and, crucially, provides excellent intrinsic stability against dorsal and plantar displacement due to the interlocking nature of the two bone fragments. This stability is a significant advantage over some linear osteotomies, which may require more rigid internal fixation and are prone to displacement.

The surgical technique is precise and methodical. Through a medial incision over the first MTPJ, the surgeon exposes the medial eminence. The prominent portion of the medial metatarsal head is resected, but care is taken to preserve the sagittal groove, a critical landmark for the sesamoid apparatus. The apex of the V-shaped osteotomy is centered within the metatarsal head, typically about 5-10mm from the joint surface. The two arms of the ‘V’, each usually angled at 60 degrees, are then carefully created with a oscillating saw, directed proximally. The capital fragment (the metatarsal head) is then manually translated laterally, effectively reducing the intermetatarsal angle between the first and second metatarsals. This lateral shift of the head recenters the sesamoids beneath it and realigns the articular surface of the metatarsal head with the proximal phalanx. The displaced fragment is typically fixed with a single, small compression screw or a bioabsorbable pin, which provides rotational control and enhances the already favorable stability of the construct. Any remaining medial prominence is smoothed, and the medial joint capsule is tightened (medial capsulorrhaphy) to secure the correction.

The key to the success of the Chevron osteotomy lies in its appropriate application. It is predominantly indicated for mild to moderate hallux valgus deformities, generally defined by an intermetatarsal (IM) angle of less than 15 degrees and a hallux valgus angle of less than 40 degrees. It is an excellent choice for younger, active patients with good bone quality, as the osteotomy is performed within the cancellous bone of the metatarsal head, which has a rich blood supply and heals reliably. The procedure’s ability to correct the deformity while preserving the motion of the first MTPJ is another significant benefit, making it a joint-preserving operation.

However, the Chevron osteotomy has its limitations, and recognizing them is paramount to avoiding poor outcomes. It is generally contraindicated for severe deformities with a high IM angle, as the amount of lateral translation achievable is limited by the width of the metatarsal shaft. Attempting to over-correct a severe deformity can lead to instability, malunion, or avascular necrosis (AVN) of the metatarsal head. AVN is a rare but serious complication, theorized to result from the disruption of the intraosseous blood supply during the osteotomy, particularly if the dorsal or plantar capsular attachments are violated. The procedure is also less suitable for patients with significant joint arthritis (hallux rigidus), as it does not address the degenerative changes within the joint itself. In these cases, an arthrodesis (fusion) may be a more appropriate option.

The evolution of the Chevron technique demonstrates its adaptability. Surgeons have developed modifications to extend its utility. The long-arm Chevron, for instance, involves a more proximal apex and longer limbs, allowing for greater lateral translation and thus addressing moderately severe deformities more effectively. Furthermore, the addition of an Akin osteotomy (a medial closing wedge osteotomy of the proximal phalanx) can be performed concurrently with the Chevron to correct any residual hallux valgus or pronation deformity of the toe itself, creating a powerful double correction for complex presentations.

The Chevron osteotomy remains a vital and enduringly popular procedure in the surgical management of hallux valgus. Its design, which masterfully balances the competing demands of effective correction and structural stability, has stood the test of time. For the patient with a mild to moderate bunion deformity, it offers a reliable path to pain relief, improved foot alignment, and a return to normal activity with a low complication profile. While not a panacea for all bunion types, its clear indications, proven biomechanical advantages, and potential for modification solidify its status as a fundamental and indispensable technique. As with all surgical interventions, its success hinges on the surgeon’s meticulous technique and, most importantly, the careful selection of the right patient for the right procedure. In the pantheon of bunion corrections, the Chevron osteotomy rightly holds its place as a gold standard.

The human foot, a masterpiece of engineering comprising 26 bones, 33 joints, and a complex network of ligaments, tendons, and nerves, is designed for one primary purpose: weight-bearing locomotion. When we consider cancer, our minds typically turn to more common sites like the lung, breast, or prostate. It is therefore counterintuitive to imagine a life-threatening disease taking root in this foundational structure. Yet, cancer can indeed affect the foot, and when it does, it presents a unique and often insidious clinical challenge. The impact of cancer on the foot is multifaceted, arising from primary malignancies, metastatic disease, and the indirect consequences of systemic cancer treatments, each leaving a distinct and debilitating footprint.

Primary cancers originating in the foot are exceptionally rare, constituting less than 1% of all bone and soft tissue tumors. This very rarity is a double-edged sword; it means the likelihood is low, but it also increases the risk of misdiagnosis. A persistent, painful lump or swelling in the foot is far more likely to be attributed to a benign condition like a ganglion cyst, plantar fasciitis, or a stress fracture. This diagnostic delay can be catastrophic for aggressive malignancies. The most common primary malignant tumor of bone, osteosarcoma, can occur in the bones of the foot, particularly the calcaneus (heel bone). It often presents with progressive pain, worse at night, and a palpable mass. Similarly, synovial sarcoma, a malignant soft tissue tumor, has a predilection for the extremities and can develop in the foot and ankle. These tumors are often painless in their early stages, masquerading as a simple, harmless bump. The challenge for both patient and physician is to recognize the “red flags”—a mass that is enlarging, deep-seated, larger than five centimeters, or painful—that warrant further investigation with advanced imaging like MRI and a definitive biopsy. The treatment for these primary cancers is typically aggressive, often involving a combination of chemotherapy, radiation, and surgery. Limb-salvage surgery, which aims to remove the tumor while preserving a functional limb, is a complex endeavor in the foot due to its compact anatomy, sometimes leading to significant functional impairment even when amputation is avoided.

A more common, though still rare, way cancer affects the foot is through metastasis—the spread of cancer from a primary site elsewhere in the body. Cancers that commonly metastasize to bone, such as those of the lung, breast, kidney, and prostate, can seed tumors in the bones of the foot. Metastasis to the foot is an unusual event, representing only a small fraction of all bone metastases, but it is a grave prognostic sign, indicating widespread disease. The presentation can be deceptively simple. A patient with a known history of cancer, or sometimes with no prior diagnosis, may present with what seems to be gout, a stress fracture, or an infection. The pain is often severe, unrelenting, and not proportionate to physical activity. Pathological fractures—breaks in a bone weakened by tumor—can occur with minimal or no trauma. Diagnosing a foot metastasis requires a high index of suspicion. Its discovery can be the first clue to an occult malignancy or a sign of recurrence in a patient thought to be in remission, fundamentally altering their disease stage and treatment plan.

Beyond the direct invasion of cancerous cells, the foot suffers profoundly from the indirect effects of cancer and its treatments, a category of conditions known as paraneoplastic syndromes and treatment-related toxicities. One of the most debilitating is chemotherapy-induced peripheral neuropathy (CIPN). Many common chemotherapeutic agents, such as platinum-based drugs and taxanes, are toxic to the peripheral nerves. This damage most often manifests in a “stocking-and-glove” distribution, meaning the hands and feet are affected first. Patients describe a spectrum of sensations from tingling and “pins and needles” to burning pain, numbness, or a feeling of walking on cotton wool. This sensory loss is not merely uncomfortable; it is disabling. It disrupts proprioception—the body’s ability to sense its position in space—leading to gait instability, balance problems, and a high risk of falls. The loss of protective sensation also makes the foot vulnerable to unrecognized injury, poorly fitting shoes, and the development of painless ulcers that can become infected, a particularly dangerous scenario for an immunocompromised patient.

Furthermore, cancer itself and certain treatments can create a hypercoagulable state, increasing the risk of developing deep vein thrombosis (DVT) in the legs. While the DVT may form in the calf, its consequences directly impact the foot, which may become swollen, painful, and discolored. In severe cases, impaired circulation can lead to critical limb ischemia. Immunosuppression from chemotherapy leaves patients susceptible to opportunistic infections, including fungal infections of the toenails or athlete’s foot, which can become severe and difficult to treat. Gouty arthritis can also be triggered or worsened by chemotherapy, as the rapid death of tumor cells releases purines, leading to painful inflammation in the joints of the foot, most classically the big toe.

The psychosocial and functional impact of cancer in the foot cannot be overstated. The foot is fundamental to our independence. Pain, deformity, or sensory loss directly compromises the basic act of walking. This can lead to social isolation, an inability to work, and a loss of the simple joys of life, from taking a walk to playing with one’s children. The constant fear of a missed diagnosis, the visible alteration of one’s body, and the struggle with chronic pain contribute significantly to the overall burden of a cancer diagnosis.

While cancer in the foot is a rare occurrence, its effects are profound and disproportionately disruptive. It can arise as a silent primary tumor, a harbinger of widespread metastatic disease, or as a cascade of debilitating side effects from life-saving treatments. The foot’s role as the literal foundation of our mobility means that any pathology here strikes at the core of a patient’s quality of life. This underscores the critical importance for both healthcare providers and patients to maintain a high level of vigilance. A persistent or atypical foot symptom, especially in the context of a known cancer history, must never be dismissed lightly. It is through this awareness that we can hope to alleviate this unseen burden, ensuring that the foundation upon which we stand and move remains as strong and supported as possible in the face of a formidable disease.

The human foot, a marvel of biomechanical engineering, is tasked with the formidable duty of bearing the body’s entire weight while facilitating locomotion. When its intricate architecture falters, common and often painful deformities can arise, none more prevalent than the hallux valgus, colloquially known as a bunion. Characterized by a progressive lateral deviation of the great toe and a painful, prominent medial eminence on the first metatarsal head, this condition can significantly impair mobility and quality of life. Among the vast array of over 100 described surgical corrections, the Austin bunionectomy, also known as a distal chevron osteotomy, stands as a cornerstone procedure. Its enduring popularity over nearly six decades is a testament to its elegant design, procedural versatility, and reliable outcomes for a specific subset of patients, establishing it as a refined and powerful tool in the foot and ankle surgeon’s armamentarium.

The procedure is named after Dr. Dudley J. Austin, a Texas podiatrist who first described and popularized the technique in the early 1960s, though the chevron-shaped cut itself was initially conceptualized by Corless in 1976 as a modification. The core principle of the Austin bunionectomy is a distal metaphyseal osteotomy. Unlike procedures that involve the metatarsal shaft or its base, the Austin focuses on the head of the first metatarsal bone. The surgeon makes a precise “V”-shaped or chevron cut in the metaphyseal region, which is the wider, cancellous bone area just behind the joint. This location is biomechanically advantageous as the rich blood supply and broad, stable surface area of the cancellous bone promote rapid and reliable healing. Once the capital fragment (the head) is freed, it can be translated laterally—shifted sideways—to reduce the intermetatarsal angle between the first and second metatarsals, thereby correcting the fundamental bony abnormality causing the bunion.

The technical execution of the Austin procedure is a meticulous process that underscores its elegance. Typically performed under regional anesthesia, the surgery begins with a medial incision over the first metatarsophalangeal joint (MTPJ). After protecting the surrounding nerves, the surgeon exposes the medial eminence, which is then resected, removing the painful bump. The hallmark of the procedure follows: the creation of the chevron osteotomy with an apex directed proximally, usually at a 60-degree angle. Using specialized instruments, the capital fragment is then carefully shifted laterally, typically by 4-6 millimeters. This lateral translation is the key to the correction, as it effectively realigns the metatarsal and decompresses the faulty biomechanics. The new position is secured with one or two permanent or bioabsorbable screws, which provide rigid internal fixation. This stability is crucial as it allows for early, guarded weight-bearing and motion, a significant advantage over techniques requiring prolonged non-weight-bearing casts. Finally, a medial capsulorrhaphy—tightening of the joint capsule—is performed to provide soft-tissue balance and maintain the corrected position of the great toe.

The primary indication for an Austin bunionectomy is a mild to moderate hallux valgus deformity. This is typically defined by an intermetatarsal angle (IMA) of less than 15 degrees and a hallux valgus angle (HVA) of less than 40 degrees. Its success is contingent upon careful patient selection. Ideal candidates are individuals with good bone quality, a flexible deformity, and a congruent or mildly incongruent MTPJ. The procedure is particularly well-suited for younger, active patients due to its stability and potential for quicker rehabilitation. However, the Austin is not a panacea for all bunions. It is generally contraindicated for severe deformities with a high IMA, significant arthritis in the MTPJ, osteopenic bone, or a history of avascular necrosis (AVN) of the first metatarsal head. In cases of severe deformity, a basal osteotomy or a Lapidus arthrodesis (fusion of the first metatarsal-cuneiform joint) may be more appropriate to address the pathology at its source.

The benefits of the Austin bunionectomy are numerous and explain its sustained popularity. First, its intrinsic stability, afforded by the chevron shape and rigid internal fixation, promotes predictable healing and enables early functional recovery. Patients can often begin weight-bearing in a surgical boot within a few weeks, a stark contrast to the six or more weeks of non-weight-bearing required by many other osteotomies. Second, the procedure is performed entirely within the metaphysis, an area of excellent vascularity, which minimizes the risk of nonunion and mitigates, though does not eliminate, the risk of the dreaded complication of avascular necrosis of the metatarsal head. Third, it is a versatile procedure that can be easily combined with adjunctive procedures, such as an Akin osteotomy (a closing wedge osteotomy of the proximal phalanx) to address concomitant toe deformities, or a distal soft tissue release for enhanced correction. Finally, it is a technically reproducible procedure that offers excellent cosmetic and functional results, with high patient satisfaction rates when performed on the appropriate deformity.

Despite its many advantages, the Austin bunionectomy is not without potential risks and limitations. As with any surgery, general risks include infection, nerve injury, bleeding, and stiffness. Specific to the Austin, the most significant concerns are under-correction or recurrence of the deformity, particularly if performed on a patient with a borderline or too-high IMA. The lateral translation of the capital fragment is mechanically limited; attempting to shift it too far can compromise its stability and blood supply. The most feared complication is avascular necrosis (AVN) of the first metatarsal head, which can lead to joint collapse and severe arthritis. This risk is associated with an over-aggressive lateral soft-tissue release that can damage the vital blood supply entering from the lateral side. Other potential issues include transfer metatarsalgia (pain under the second metatarsal head) if the first metatarsal is inadvertently elevated during the procedure, or degenerative joint disease if the articular surface is compromised.

The Austin bunionectomy remains a gold standard procedure for the surgical correction of mild to moderate hallux valgus deformities. Its enduring legacy, six decades after its introduction, is built upon a foundation of sound biomechanical principles: a stable, V-shaped osteotomy in a well-vascularized bone region that allows for precise correction and secure fixation. This design facilitates a more rapid rehabilitation and return to function, aligning with the demands of modern patients. While it is not a universal solution and demands strict adherence to its indications to avoid complications, its procedural elegance, reliability, and proven track record of high patient satisfaction secure its place as a fundamental and highly effective technique. The Austin bunionectomy exemplifies how a thoughtfully designed and expertly executed surgical intervention can successfully restore form, function, and comfort to the compromised foot.