Introduction
Hallux valgus, commonly known as a bunion, is a progressive foot deformity characterized by lateral deviation of the great toe and medial deviation of the first metatarsal. It often leads to pain, functional impairment, and aesthetic concerns. 1 Surgical correction is generally recommended when conservative treatments fail. Recently, minimally invasive surgery (MIS) has gained popularity as an alternative to traditional open procedures for hallux valgus correction. 2 MIS aims to reduce soft tissue disruption, decrease postoperative pain, and accelerate recovery while achieving the same or better outcomes as traditional techniques. 3, 4 This literature review explores the factors to be considered for MIS in hallux valgus, relevant risk factors, the various surgical techniques, and the associated advantages and disadvantages.
The choice of MIS for hallux valgus correction depends on several factors, including the severity of the deformity, patient age, activity level, and expectations from the surgery. Surgeons must assess radiographic parameters, such as the hallux valgus angle (HVA) and intermetatarsal angle (IMA), to determine the appropriateness of MIS.5, 6 Mild to moderate cases are ideal candidates for MIS, while severe deformities may still require traditional approaches. The flexibility of the joint and soft tissues, as well as any associated conditions like arthritis or sesamoid subluxation, are also important factors in determining the suitability for MIS.
Risk Factors
Risk factors for poor outcomes in MIS for hallux valgus include advanced age, severe deformities, and the presence of comorbidities such as rheumatoid arthritis or diabetes, which can impair healing. Smoking, obesity, and osteoporosis are other factors that may increase the likelihood of complications, including delayed bone healing and infection. 7, 8 Additionally, patients with prior foot surgeries or significant joint stiffness may not respond well to MIS techniques, as they require more precise correction than the minimally invasive approach might allow. The decision to choose minimally invasive surgery (MIS) or conventional open surgery for hallux valgus depends on several factors (Table 1 )
Table 1
Comparative table between Minimally Invasive Surgery (MIS) and Conventional Surgical Methods for Hallux Valgus, which can assist foot and ankle surgeons in decision-making:
Key Considerations for Surgeons
Patient Factors: MIS may be more appropriate for younger, active patients with mild to moderate deformities, while conventional methods may be better for patients with severe deformities, comorbidities, or prior surgeries.
Surgeon Expertise: Surgeons with significant experience in MIS may achieve comparable or better outcomes than with conventional surgery, but for those less experienced, traditional methods may be more reliable.
Postoperative Expectations: Patients preferring quicker recovery, minimal scarring, and outpatient procedures may opt for MIS, while those who prioritize long-term durability and correction of severe deformities might prefer conventional surgery.
This table helps guide surgeons in choosing the appropriate surgical method based on individual patient needs and deformity characteristics.
Table 2
That explains different Minimally Invasive Surgical (MIS) techniques for hallux valgus, covering the procedure, indications, advantages, and disadvantages.
Table 3
That provides a more detailed overview of various studies supporting minimally invasive surgery (MIS) techniques for Hallux Valgus correction:
Techniques of MIS (Table 2)
MIS for hallux valgus correction typically involves percutaneous osteotomies and soft tissue releases through small incisions, with minimal disruption to surrounding tissues. The most common techniques include the Reverdin-Isham osteotomy, percutaneous distal metatarsal osteotomy (DMMO), and the minimally invasive Chevron and Akin procedures. These techniques aim to realign the first metatarsal and correct the deformity with the help of small burrs and specialized instruments. Percutaneous fixation, often using screws or wires, is employed to maintain the new position of the bones. Fluoroscopy is frequently used during the procedure to guide the surgeon.
Literature Review Findings (Table 3) 9, 10, 11, 12, 13, 14, 15, 16, 17, 18
Several studies have compared MIS techniques to open surgery for hallux valgus. While the results have been mixed, many studies have shown that MIS can be as effective as open surgery in correcting the deformity and improving patient outcomes. Some studies have also found that MIS may be associated with a shorter recovery time and less postoperative pain.
Discussion
Minimally Invasive Surgery (MIS) for hallux valgus has evolved significantly over the past decades, offering a less disruptive alternative to traditional open surgical methods. Hallux valgus, characterized by the lateral deviation of the big toe and medial deviation of the first metatarsal, presents a challenging deformity for both patients and surgeons. The development and refinement of MIS techniques aim to address this condition with reduced soft tissue damage, faster recovery, and improved cosmetic outcomes compared to conventional approaches.
Historical Context and Prevalence
The concept of minimally invasive surgery began gaining traction in the late 20th century as advancements in surgical instruments and techniques allowed for less invasive interventions across various medical fields. In podiatric surgery, MIS for hallux valgus has been driven by the desire to minimize postoperative pain, reduce recovery times, and improve functional outcomes. The adoption of MIS in hallux valgus surgery has increased steadily as evidence has demonstrated its potential benefits, leading to widespread use in contemporary clinical practice.
Techniques of MIS for Hallux Valgus
Several MIS techniques are now commonly used for hallux valgus correction, each with its own indications, procedural details, advantages, and limitations:
Percutaneous Chevron-Akin OsteotomyThis technique involves a combination of the Chevron osteotomy for the metatarsal head and the Akin osteotomy for the proximal phalanx. It is suited for mild to moderate hallux valgus with an intermetatarsal angle of less than 16°. The procedure involves small incisions, allowing for realignment of the bones with screws. Advantages include minimal soft tissue damage and quicker recovery, but the technique requires precise execution to avoid complications such as malunion or overcorrection .
Distal Metatarsal Osteotomy (DMMO)DMMO involves a small incision to perform a Chevron osteotomy at the distal metatarsal head. It is ideal for elderly patients or those with mild to moderate deformities. The primary benefits are reduced recovery time and minimal soft tissue disruption. However, its limitations include inadequate correction for severe deformities and potential recurrence of symptoms if not performed accurately .
Percutaneous Scarf OsteotomyThe Scarf osteotomy is a widely used technique for moderate to severe hallux valgus, involving an "S"-shaped cut along the metatarsal shaft, which allows for bone realignment and stabilization with screws. This technique offers stable correction and favorable long-term outcomes, but is technically demanding and may pose risks such as nerve damage if not carefully performed .
Minimally Invasive Reverdin-Isham OsteotomyThis procedure uses a percutaneous approach to correct the metatarsal head without internal fixation. It is best for mild deformities and provides quick recovery with minimal risk of hardware-related complications. However, its limitations include instability due to the lack of internal fixation and a higher risk of incomplete correction or recurrence .
Minimally Invasive Lapidus ProcedureThe Lapidus procedure involves fusing the first tarsometatarsal joint through small incisions, which is effective for severe hallux valgus with hypermobility of the first ray. It offers stable long-term correction with a lower recurrence rate, though the recovery is extended due to the joint fusion, necessitating non-weight-bearing for several weeks .
Bösch Percutaneous TechniqueThis technique involves an osteotomy at the metatarsal head performed through a percutaneous approach, without the use of internal fixation. It avoids hardware-related complications but requires postoperative immobilization, which may lead to incomplete correction or recurrence of the deformity.
Advantages of MIS
MIS techniques offer several benefits over conventional open surgery, including smaller incisions, less soft tissue damage, and reduced post-operative pain. These factors contribute to faster recovery times, allowing patients to return to normal activities sooner. Furthermore, the cosmetic outcomes are often better due to smaller scars, and early weight-bearing is possible in many cases. MIS is particularly advantageous for elderly patients or those with mild to moderate deformities where aggressive correction is not required.
Disadvantages of MIS
Despite its advantages, MIS is not without risks. The techniques are technically demanding, requiring a high level of precision and experience. Surgeons must be well-versed in the nuances of each procedure to avoid complications such as malunion, nonunion, or nerve damage. Additionally, the effectiveness of MIS is limited for severe deformities, which may require more extensive correction that can only be achieved through conventional open surgery. Another challenge is the potential for recurrence, especially in cases where internal fixation is not used .
Studies have consistently highlighted the benefits of MIS techniques, including reduced postoperative pain, shorter recovery times, and improved cosmetic outcomes. For example, Trnka (2020) emphasizes the effectiveness of MIS in reducing soft tissue trauma and enhancing patient satisfaction. Maffulli et al. (2020) and Malagelada et al. (2019) provide evidence supporting the efficacy of various MIS techniques in achieving stable deformity correction with minimal complications. However, these techniques are not without limitations. The technical complexity of MIS procedures requires a high level of skill and experience to avoid complications such as malunion or nerve damage. Additionally, MIS is often less suitable for severe deformities that may require more invasive conventional methods for optimal correction.
Conclusion
MIS for hallux valgus represents a significant advancement in surgical treatment, offering numerous benefits over traditional methods. While it has proven effective for mild to moderate deformities with a lower risk of complications and faster recovery, its application for severe cases remains limited. Surgeons must carefully evaluate the specific characteristics of each patient and the severity of the deformity when selecting the appropriate surgical approach. Continued research and development in MIS techniques are likely to enhance their applicability and outcomes, further establishing their role in contemporary foot and ankle surgery
Key Insights
Minimally Invasive Chevron and Akin Osteotomy: Redfern & Vernois (2016) and Vernois & Redfern (2013) conducted large-scale studies showing MIS Chevron and Akin Osteotomy as highly effective for mild to moderate hallux valgus, with high patient satisfaction and low complication rates. The reduced soft tissue trauma led to faster recovery times and less postoperative pain.
Percutaneous Chevron Osteotomy (PCO): Lee et al. (2020) demonstrated that this technique achieved excellent correction in hallux valgus deformities, with smaller scars, less postoperative swelling, and faster recovery compared to open methods. However, this technique is best suited for mild to moderate deformities.
Reverdin-Isham Osteotomy: Brogan et al. (2016) and Grifka et al. (2019) reported promising results with this technique, particularly for mild-to-moderate deformities, as it involves smaller incisions and fewer complications. The studies emphasized reduced soft tissue damage, better cosmesis, and quicker return to normal activities, but noted that the technique is less suited for severe deformities.
Percutaneous Scarf Osteotomy: This technique, examined by Grifka et al. (2019), offers benefits in terms of quicker recovery, reduced infection risks, and smaller scars. It’s particularly useful for those requiring faster rehabilitation with minimal postoperative discomfort.
Percutaneous Akin Osteotomy: Perez et al. (2017) demonstrated that this MIS technique is highly effective for correcting mild hallux valgus, with minimal complications and high patient satisfaction. It is preferred for mild deformities and rural settings due to its simplicity and lower resource demand.
Percutaneous Distal Metatarsal Osteotomy (DMMO): Trnka et al. (2021) showed reduced recovery time, lower complication rates, and better cosmetic outcomes compared to conventional surgery. This study highlights the effectiveness of the DMMO technique, especially in patients seeking faster recovery and minimal scarring.
Combined Techniques (Chevron-Akin): Magnan et al. (2020) presented data supporting the combination of Chevron and Akin osteotomies in MIS, showing significant improvement in functional outcomes, pain relief, and cosmesis. This technique is beneficial in rural and resource-limited settings due to its minimally invasive nature and faster rehabilitation.
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