Risk of Damaging Anatomical Structures During Minimally Invasive Hallux Valgus Correction (Bösch Technique): An Anatomical Study

Percutaneous hallux valgus surgery: Anatomical study of its safety and effectiveness

BACKGROUND AND HYPOTHESIS

Although percutaneous hallux valgus surgery is increasing in popularity, concerns about safety regarding neurovascular and tendinous structures remain. The first aim of this body-donor study was to evaluate the safety of three common percutaneous portals. Secondly, to evaluate percutaneous surgery effectiveness in completing adductor tendon release and first ray osteotomies.

PATIENTS AND METHODS

Twenty body-donor feet were included and underwent three percutaneous procedures, which are commonly performed in combination: distal metatarsal osteotomy, proximal phalanx osteotomy and adductor tendon release. After surgery, the distance between surgical portals and relevant neurovascular structures was measured. Damage to this neurovascular structures, tendons or articular cartilage was noted. Completion of adductor tendon release and osteotomies was verified.

RESULTS

The medial dorsal digital nerve of the hallux was damaged in two specimens. Mild peritendon damage was observed in two feet. The rest of neurovascular and tendinous structures were intact. No cartilage damage was observed. The distance between the adductor tenotomy portal and the lateral dorsal digital nerve of the hallux and the first dorsal metatarsal artery was 3.3mm (SD 1.4) and 2.4mm (SD 1.8), respectively. Complete adductor tenotomy was achieved in 14 feet.

CONCLUSIONS

The structure with the highest risk of damage during percutaneous hallux valgus surgery is the medial dorsal digital nerve. The lateral dorsal digital nerve and the first dorsal metatarsal artery might be at risk due to the small distance to the adductor tendon release portal. A deep anatomical knowledge and a meticulous surgical technique are required to avoid lesions to neurovascular and tendinous structures.

LEVEL OF EVIDENCE

V, Cadaveric study.

Bösch osteotomy for hallux valgus correction: results at a mean 10-year follow-up

INTRODUCTION

Bösch osteotomy (BO), which is a first metatarsal subcapital osteotomy stabilised with a K-wire, is a surgical option to correct hallux valgus (HV). The aim of this study was to assess the long-term clinical and radiographic results in a cohort of patients treated at our institution with such osteotomy.

METHODS

In this retrospective monocentric single-surgeon cohort study, we included 58 HVs (46 patients) who underwent HV correction by BO and were followed at a minimum of 7 years. The range of motion (ROM), the American Orthopaedic Foot and Ankle Society's Forefoot scale (AOFAS-FS) and the Visual Analogic Scale (VAS) for pain were recorded. On weightbearing radiographs, the Hallux Valgus Angle (HVA), Intermetatarsal Angle (IMA), the Distal Metatarsal Articular Angle (DMAA), and the Lateral Sesamoid Position (LSP) were measured and compared with pre-operative values. The complication rate and first metatarsophalangeal joint stiffness were also assessed.

RESULTS

At a mean follow-up of 10 ± 2 (7-17) years, mean ± standard deviation AOFAS-FS and VAS were 89 ± 11 (67-93) and 2.1 ± 2.8 (0-7) points, respectively. In 42 (72%) cases there was no limitation in the choice of footwears. Radiographically, we found a significant improvement in the HVA (from 33.9° ± 6.7 to 18.8° ± 5.6, p < 0.001), in the IMA (14.2° ± 3.1 to 9.4° ± 2.7, p < 0.001), in the DMAA (from 30.3° ± 6.8 to 11.5° ± 5.1, p < 0.001) and in LSP (median value from 3 to 1, p < 0.001). In 36 (62%) cases the ROM was greater than 75° while in 22 (38%) it ranged between 30° and 75°. Minor complications occurred in six (10%) cases, which did not require any further surgery at the longest follow-up.

CONCLUSION

Bösch technique provided satisfactory clinical and radiographic outcomes in the treatment of hallux valgus which persisted at a mean 10-year follow-up. The complication rate did not differ from more recent techniques described in literature.

LEVEL OF EVIDENCE

Level IV, retrospective cohort study.

Minimally Invasive Chevron-Akin for Correction of Moderate and Severe Hallux Valgus Deformities: Clinical and Radiologic Outcomes With a Minimum 2-Year Follow-up

BACKGROUND

The minimally invasive chevron-Akin (MICA) technique has already demonstrated efficacy compared with other known surgical treatments for mild to moderate hallux valgus (HV). MICA combines percutaneous osteotomies with the benefits of modern, rigid internal fixation. The aim of study was to evaluate the radiographic parameters, clinical improvement, and potential complications in moderate to severe HV cases, operated using the MICA technique.

METHODS

Retrospective study including 70 feet with HV operated using the MICA technique. The AOFAS hallux MTP-IP score and radiographics for HV evaluation were applied preoperatively, and after 6 months, 1 year, and 2 years of follow-up. The following radiographic parameters were measured: metatarsophalangeal hallux valgus angle (HVA), distal metatarsal articular angle (DMAA), interphalangeal angle (IPA), and intermetatarsal angle (IMA).

RESULTS

The average preoperative VAS pain score was 8.2 ± 1.5, which improved to 1.2 ± 2.2 at 24 months. The mean preoperative IMA was 14.8 ± 3.6 degrees compared with a mean of 7.5 ± 2.1 degrees (P < .01) at 24 months. The preoperative HVA value averaged 30.4 ± 9.8 degrees and at 6 months postoperatively 11.1 ± 6.8 degrees (P < .01), which remained stable until measured at 24 months. The mean preoperative DMAA was 16.3 ± 8.6 degrees and at the 6-month follow-up was 7.8 ± 5.4 degrees (P < .01). The mean preoperative IPA was 7.63 ± 4.4 degrees compared with a mean of 6.28 ± 3.5 degrees (P > .05) at 24 months. Complications included painful hardware (14.28%), neuropathic pain (2.85%), and loss of correction (4.28%).

CONCLUSION

In this retrospective review from a single center, we found the MICA technique to be an effective procedure for correcting moderate to severe HV, with a low rate of recurrence and an acceptable rate of complications. Patients undergoing the surgical procedure in our series showed a significant reduction in radiographic parameters and a significant improvement in clinical scores, maintaining these results over time.

LEVEL OF EVIDENCE

Level IV, retrospective study.

Correction Power of Percutaneous Adductor Tendon Release (PATR) for the Treatment of Hallux Valgus: A Cadaveric Study

Osteotomies are commonly used in order to correct hallux valgus deformity. However, soft tissue structures also play an essential role in the etiology, progression, and treatment of hallux valgus (HV). The purpose of the present study was to analyze the correcting power (varus), reduction strength (sesamoid) and rotation of metatarsal and proximal phalanx after percutaneous adductor tendon release (PATR). To date, no study addresses this issue. Eleven cadaveric fresh-frozen below-the-knee cadaveric lower limbs with associated hallux valgus deformity were used. These specimens were subjected to a constant abduction force after PATR. HV and intermetatarsal angles showed statistically significant differences when comparing the preoperative and postoperative periods. PATR showed to be a reliable technique as the adductor tendon was completely released in 9 cases, and 75% released in the remaining 2 feet. The study supports that PATR provides powerful and quantifiable correction of HV deformity and can be accurately performed percutaneously.

Biomechanical Comparison of 2 Common Techniques of Minimally Invasive Hallux Valgus Correction

BACKGROUND

Hallux valgus is one of the most common surgically corrected forefoot deformities. Compared to open procedures, minimally invasive (MIS) treatment of hallux valgus has resulted in decreased operative time, reduced complication rates, and greater patient satisfaction. Historically, distal chevron osteotomies are the standard for moderate hallux valgus correction. To our knowledge, no studies have evaluated biomechanical strength of transverse and chevron distal first metatarsal osteotomy (DMO) constructs. The purpose of this study was to evaluate the biomechanical strength of these techniques.

METHODS

Eighteen cadaveric specimens (9 matched pairs) were randomized to transverse or chevron DMO. Each technique was performed by a separate fellowship-trained orthopedic foot and ankle surgeon. Radiographic images were analyzed. Biomechanical testing was performed using Instron Mechanical System. Ultimate load to failure, yield load, and stiffness were assessed. A 10-N preload was applied to the sesamoid bones for stability. A coaxial compression rate (10 mm/min) was applied until failure was observed. Mean and standard deviations were compared. All cadaveric specimens were male.

RESULTS

There was no significant difference in percent metadiaphyseal shift between osteotomies (P = .453). The most common mode of failure was fracture at screw insertion site (55.6%), followed by failure at osteotomy site (44.4%). A trend toward increased ultimate load to failure (P = .480), yield load (P = .054), and stiffness (P = .438) among transverse compared to chevron osteotomy was observed, but this difference was not statistically significant.

CONCLUSION

Biomechanical testing demonstrated no significant difference in ultimate load, yield load, and stiffness between MIS transverse and chevron osteotomy constructs; a trend toward increased strength in the transverse osteotomy cohort was observed. Chevron osteotomies may result in early failure by relative ease of cutout through cancellous bone compared to transverse osteotomies in which failure requires cortical cutout.

CLINICAL RELEVANCE

Use of MIS techniques for hallux valgus correction is gaining clinical traction. Although various clinical studies have evaluated outcomes of these MIS techniques, biomechanical studies have been minimal. Specifically, the potential biomechanical benefits of various MIS hallux valgus osteotomy techniques have not been delineated to date. The content of this manuscript is quite timely, given the rise in use of these MIS techniques.

Fixation Principles in Minimal Incision Hallux Valgus Surgery

Minimal incision surgical principals rely on the soft tissue envelope to maintain stability that is supplemented by a variety of clinically recommended fixation methods. The extended distal first metatarsal osteotomy has renewed interest because of the ability to laterally translate, angulate, and rotate the metatarsal head in proper alignment with the sesamoids to a neutral alignment. The soft tissue envelope of capsule, ligaments, and tendons will re-align once the bone deformity is corrected. The periosteum is maintained to provide a biologic scaffold for new bone formation and must be minimally disrupted during the intervention."

Operative Approach to Adult Hallux Valgus Deformity: Principles and Techniques

Hallux valgus deformity is a progressive forefoot deformity consisting of a prominence derived from a medially deviated first metatarsal and laterally displaced great toe, with or without pronation. Although there is agreement that the deformity is likely caused by multifactorial intrinsic and extrinsic factors, the best method of operative management is debated despite the creation of basic algorithms. Our understanding of the deformity and the development of newer techniques is continuously evolving. Here, we review the general orthopaedic principles of operative decision-making and management of hallux valgus deformity.

Evolution of Minimally Invasive Surgery in Hallux Valgus

Minimally invasive (MIS) or percutaneous surgery has evolved rapidly through the development of novel techniques with precise description, correct indications, and the incorporation of modifications of safe and effective techniques described in open surgery. The correct term to describe these procedures should be percutaneous and MIS should be reserved for procedures between percutaneous and open surgery (eg, osteosynthesis). According to results, third-generation techniques are useful, effective, and easier than open procedures. It seems that MIS surgery has an extensive learning curve, and therefore it may be difficult to duplicate the results shown on already-published data.

Percutaneous, Intra-articular, Chevron Osteotomy (PeICO) for the Treatment of Hallux Valgus: A Cadaveric Study

BACKGROUND

Percutaneous surgery is experiencing sustained growth based on third-generation techniques. This cadaveric study was designed with the main goal of exploring the risk of iatrogenic tendon and neurovascular lesions and defining the safe zones in a percutaneous, intra-articular, chevron osteotomy (PeICO) procedure, as well as assessing the accuracy of the osteotomy itself.

METHODS

Eight feet from below-knee fresh-frozen specimens were selected. After the procedure, the specimens were dissected, and structures were inspected for damage.

RESULTS

The results of the safety measurements were as follows: (1) distance between portal 1 (P1) and the lateral border of the extensor hallucis longus (EHL) tendon: average 17.6 mm (range 12.7-21.3); (2) distance between P1 and the dorsomedial digital nerve (DMDN): average 7.2 mm (range 1.6-10.4); (3) distance between P1 and the metatarsophalangeal joint: average 15.7 mm (range 9.4-20.5); distance between portal 2 (P2), or the osteosynthesis portal, and the metatarsophalangeal joint: average 25.5 mm (range 22-30.4); distance between P2 and the lateral border of the EHL tendon: average 12.7 mm (range 8-16.7); and distance between P2 and the DMDN: average 4.1 mm (range 1.7-8.2). There were no iatrogenic injuries. The osteotomy angulation in the sagittal plane (reproducibility) average was 85.6 degrees.

CONCLUSION

There were no iatrogenic injuries on this cadaveric study of PeICO.

CLINICAL RELEVANCE

This study will help orthopedic surgeons understand the risks of performing percutaneous surgery by mimicking an accepted open technique (chevron).