ADVERTISEMENT
Is the Lateral Release Necessary in Hallux Abducto Valgus Surgery?
Point
Yes. As these authors argue, with proper clinical assessment, the much-scrutinized lateral release may aid in correction of the HAV deformity and eliminate the pathologic retrograde force.
By Joshua Mann, DPM, Chandler Ligas, DPM, and Justin Carney, DPM
We need to ask ourselves two questions when addressing the hallux abducto valgus (HAV) deformity: What does the deformity entail, and how will we achieve the goal of correcting this deformity to provide a stable, congruent first metatarsophalangeal joint (MPJ)?
The lateral release as an adjunctive procedure in the treatment of HAV has been under scrutiny for many years. Silver identified the mechanical imbalance between the flexor and extensor tendons as well as the adductor hallucis tendon as the basic anatomic forces that accentuate the HAV deformity.1 Silver’s anatomic study had the support of Root’s theory of the pathogenesis of the HAV deformity. Root found the first MPJ unlocks as a result of abnormal pronation.2
The adductor hallucis tendon and the lateral head of the short flexor tendon increase the lateral tension on the base of the proximal phalanx via the fibular sesamoid, causing the phalanx to subluxate laterally.2 Every action has a reaction, and the subsequent lateral retrograde force of the hallux on the first metatarsal increases the first intermetatarsal angle.2 The profession has largely accepted this theory and has coined it “retrograde buckling.” Therefore, if left unaddressed, the lateral soft tissues can enhance the severity of deformity and increase the incidence of recurrence.3–5
The lateral release, although controversial, should be assessed in a systematic way to help contribute to the long-lasting correction of the HAV deformity and eliminate the pathologic retrograde force.
When Do You Perform a Lateral Release?
It is the authors’ opinion that with proper clinical assessment, the practitioner should have a high propensity to perform the lateral release. Use the term “tracking” to assess the deviation of the hallux when put through range of motion. If the hallux “kicks lateral” on dorsiflexion, this would be considered tracking and the lateral soft tissues are contributing to the deformity. One can only perform a true assessment in patients who have a reducible first intermetatarsal angle that is noted by a correction in the deformity after decreasing the transverse force on the first metatarsal head.7 Therefore, before bringing the patient into the operating room, the physician has an idea if the HAV correction would necessitate a lateral release.
In the authors’ clinical judgment, the majority of HAV deformities have a degree of lateral soft tissue contracture and will need a lateral release.
Practical Insights Into Surgical Technique
Proper anatomic identification of the lateral structures of the first MPJ is paramount to understanding the technicalities of performing the lateral release. The structures that make up the lateral soft tissue structures are the adductor hallucis tendon (transverse head and oblique head), the flexor hallucis brevis, the transverse metatarsal ligament, the metatarso-sesamoid suspensory ligament. At our institution, the senior author (JM) will address the transverse metatarsal ligament, adductor tendon, the lateral metatarso-sesamoid suspensory ligament, and occasionally the flexor hallucis brevis tendon.
Sarrafian described the oblique head of the adductor hallucis as having three components at its distal segment.6 The medial component inserts directly on the lateral sesamoid, the central component inserts on the plantar aspect of the lateral sesamoid, and the lateral component inserts on the lateral sesamoid and the plantar lateral aspect of the base of the proximal phalanx. The transverse head contains fibers that “pass over the fibers of the oblique head at the level of the lateral sesamoid, share their insertion, and terminate on the fibrous sheath of the flexor hallucis longus.” At the insertion into the fibular sesamoid, the two adductor heads join the lateral head of the flexor hallucis brevis and continue to the plantar lateral aspect of the base of the proximal phalanx as a conjoined tendon.6
As performed by the senior author, the intraoperative lateral release involves the adductor tendon from the lateral surface of the fibular sesamoid and the lateral insertion of the proximal phalanx. The release allows for adequate exposure of the lateral metatarso-sesamoid suspensory ligament, which authors have found to be a primary force leading to the malposition of the sesamoids when not addressed intraoperatively.3 After releasing the lateral metatarso-sesamoid suspensory ligament, the first metatarsal is reduced and the hallux goes range of motion. If there is no tracking present, then the lateral release is complete. However, in rare instances further lateral release will be necessary, which includes the lateral head of the flexor hallucis brevis insertion to the proximal phalanx base.
Much like a systematic approach to procedural selection of varying degrees of HAV severity, one should approach the lateral release with the same intraoperative systematic approach. Combining the anatomic expertise, a systematic approach to the lateral release, and a thorough assessment of the deformity after each step will significantly reduce complications such as over-correction.7 Historically certain practitioners believed that avascular necrosis occurred due to an over-aggressive lateral release. However, Banks and colleagues disproved this theory and validated the lateral release approach.8
Augoyard and coworkers proved the efficacy of this sequential approach and quantified how much correction can be achieved after each lateral release step based on severity.9 In their prospective review on 49 patients with intraoperative fluoroscopic analysis they found a mean decrease of 18.8 degrees in the HAV angle, a decrease of 1.7 degrees in the intermetatarsal angle, and 60% reduction of sesamoids into their anatomic position after 3 steps of the lateral release (transection of the lateral metatarso-sesamoidal ligament, release of the flexor hallucis brevis from insertion and release of the adductor hallucis tendon).9
We would like to highlight that the lateral release is an adjunct to the complete correction of the HAV deformity and should not be performed in isolation. However, if performed in proper sequential order, the practitioner will have an easier time with reduction and long-term maintenance of the correction.
Analyzing the literature of proponents to correction of the HAV deformity without lateral release, there seems to be a correlation to increased values of the sesamoid position, some of which are near the upper levels of normal.4 Therefore, the authors infer that although some HAV deformities can be corrected without lateral release, are these patients developing a higher degree of recurrence postoperatively? If the lateral release isn’t performed, how are the pathologic lateral soft tissue forces corrected?
In Conclusion
In the search for the perfect algorithm to correct the HAV deformity one should consider the necessity of the lateral soft tissue release. The HAV deformity is a continuum of pathogenesis. This continuum has both osseous and soft tissue components. The contracted lateral soft tissue structures therefore should be addressed. We believe that if the lateral release is performed adequately in a systematic approach, reproducible results with a longstanding correction will occur. Ultimately, the end goal of correcting a HAV deformity is to achieve a stable, congruent first MPJ, and a successful lateral release is often essential to accomplish this.
Dr. Mann is on the faculty of the Emory University School of Medicine. He is board certified in foot surgery and in reconstructive rearfoot and ankle surgery by the American Board of Foot and Ankle Surgery, and certified in primary podiatric medicine by the American Board of Podiatric Medicine.
Dr. Ligas is in fellowship training at Silicon Valley Reconstructive Foot and Ankle Fellowship.
Dr. Carney is a second-year resident at the Emory University School of Medicine.
Counterpoint
No. This author points out the downsides of a lateral release, citing the risk of iatrogenic trauma and post-op surgical adhesions, as well as variation in surgical techniques and anatomic structures.
By Kurtis Bertram, DPM
The lateral release is a common adjunctive procedure with hallux valgus surgery. From an anatomic perspective, adequate lateral release involves transecting the lateral collateral ligament, lateral metatarso-sesamoid suspensory ligament, the deep transverse metatarsal ligaments, and both heads of the adductor hallucis muscle.1
However, there is variation in anatomic structure and technique used for lateral release from one surgeon to another. The theory behind performing a lateral release is that it gives a more robust correction of the bunion deformity and decreases the chance of recurrence. It is often used to correct radiographic sesamoid position. Additionally, a lateral release is thought to release contracted lateral tissue, which may prevent reduction. There are conflicting opinions on whether to do a lateral release for numerous reasons.
Our opinion is that there is little benefit in reduction with increased iatrogenic trauma and unnecessary post-surgical adhesions around the first metatarsophalangeal joint (MPJ) secondary to a lateral release.
Metatarsal vs Sesamoid: Which Is the Stable Component?
The thinking is that the goal of hallux valgus surgery is to get the sesamoids back under the metatarsal head. With this often comes a lateral release to allow medial migration of the sesamoid complex back under the metatarsal head.
However, numerous studies show that the sesamoid position does not significantly change after bunion correction even with lateral release. Ramdass and Meyr measured the sesamoid position compared to the second metatarsal pre- and postoperatively in patients who received a distal metatarsal osteotomy and a lateral release.2 They found no statistical significance between tibial sesamoid position preoperatively versus postoperatively (30.6 and 30.2 respectively) relative to the second metatarsal in the transverse plane.
Another study by Woo and colleagues looked at the effect of lateral soft tissue release on sesamoid position in hallux valgus surgery by splitting two groups into osteotomy with lateral release and osteotomy alone.3 The authors found no significant difference in fibular sesamoid position between the lateral release group and osteotomy alone group (1.9mm and 1.6mm respectively). This is evidence that the sesamoids are in fact immobile, and it is the metatarsal head that is moving back over the sesamoid apparatus. Additionally, there were negative consequences in the group that received the lateral release. The group that received the lateral release had less first MPJ range of motion and increased neuritis of the first interspace postoperatively.
The Importance of the Frontal Plane in Hallux Valgus Deformity
The frontal plane, or “third plane” of the hallux valgus deformity, is crucial in understanding how to approach these cases. Dayton and colleagues looked at the hallux abductus angle, intermetatarsal angle (IMA), proximal articular set angle, and tibial sesamoid position (TSP) on radiographs in cadaveric models to examine frontal plane rotation of the first metatarsal.4 The study found that TSP was the only parameter that correlated with first metatarsal rotation, which further supports that the metatarsal moves on immobile sesamoids. Derotation of the metatarsal in the frontal plane so the sesamoid, in the crista, return to a normal position seems to be a more anatomic approach to reduction than release of the lateral soft tissue structures.
Insights on MIS Surgery (Without Lateral Release)
As minimally invasive (MIS) hallux valgus surgery is gaining traction, it is worth mentioning its technique and lack of soft tissue dissection. Siddiqui and LaPorta described their technique and stated that maintaining the soft tissue attachments around the first MPJ allows “circumferential mobility” and stability of the capital fragment to get the metatarsal head back over the sesamoid apparatus as well as preserve vascularity to the metatarsal head.5,6
In a later study of outcomes of MIS hallux valgus surgery, Siddiqui found the TSP changed from a mean of 5.4 preoperatively to 2 postoperatively.6 This study only included patients who did not undergo any lateral soft tissue release during the MIS correction and showed a statistically significant difference in pre- and postoperative tibial sesamoid position. This shows the benefits of leaving the soft tissue structures on the lateral side of the first MPJ alone and that the lateral release is not necessary to get the metatarsal head back over the sesamoid apparatus.
Other Thoughts to Consider
Longstanding bunion deformities will typically have an adductor tendon that is stiff as it has been in this fixed position for years. With adequate reduction of the first MPJ and IMA, the adductor tendon has essentially loosened. Additionally, more MPJ dissection and work can lead to a stiff joint postoperatively, nerve injury and hallux varus. We believe that adequate reduction and alignment of the first metatarsal negate the need for a lateral release.
Dr. Bertram is a fellowship-trained attending foot and ankle specialist at MedStar Washington Hospital Center. He is an Associate of the American College of Foot and Ankle Surgeons.
Dr. Thomas Milisits is a second-year resident at MedStar Washington Hospital Center.
Point References
1. Silver D. The operative treatment of hallux valgus. J Bone Joint Surg. 1923; 5:225–232.
2. Root ML, Orien WP, Weed JH. Forefoot deformity caused by abnormal subtalar joint pronation. In Normal and Abnormal Function of the Foot. Clinical Biomechanics Corp., Los Angeles, 1977, p. 349.
3. Okuda R, Kinoshita M, Yasuda T, Jotoku T, Kitano N, Shima H. Postoperative incomplete reduction of the sesamoids as a risk factor for recurrence of hallux valgus. J Bone Joint Surg. 2009; 91(7):1637–1645. https://doi.org/10.2106/JBJS.H.00796
4. Boberg JS, Judge MS. Follow-up of the isolated medial approach to hallux abducto valgus correction without interspace release. J Am Podiatr Med Assoc. 2002; 92(10):555–562. https://doi.org/10.7547/87507315-92-10-555
5. Ravenell RA, Camasta CA, Powell DR. The unreliability of the intermetatarsal angle in choosing a hallux abducto valgus surgical procedure. J Foot Ankle Surg. 2011; 50(3):287–292. https://doi.org/10.1053/j.jfas.2011.02.001
6. Kelikian A, Sarrafian S. Sarrafian’s Anatomy of the Foot and Ankle: Descriptive, Topographical, Functional. 3rd Edition. LWW. 2011.
7. Panchbhavi VK, Trevino SG. First web space soft tissue release: A new sequential approach. Tech Foot Ankle Surg. 2005; 4(3):184–89. doi: 10.1097/01.btf.0000173701.15843.b3
8. Banks AS. Avascular necrosis of the first metatarsal head. A different perspective. J Am Podiatr Med Assoc. 1999; 89(9):441–453. https://doi.org/10.7547/87507315-89-9-441.
9. Augoyard R, Largey A, Munoz MA, Canovas F. Efficacy of first metatarsophalangeal joint lateral release in hallux valgus surgery. Orthopaed Traumatol Surg Res. 2013; 99(4):425–31. https://doi.org/10.1016/j.otsr.2013.01.009.
Counterpoint References
1. Schneider W. Influence of different anatomical structures on distal soft tissue procedure in hallux valgus surgery. Foot Ankle Int. 2012; 33(11):991–6.
2. Ramdass R, Meyr AJ. The multiplanar effect of first metatarsal osteotomy on sesamoid position. J Foot Ankle Surg. 2010; 49(1):63–67.
3. Woo K, Yu IS, Kim JH, Sung KS. Effect of lateral soft tissue release on sesamoid position in hallux valgus surgery. Foot Ankle Int. 2015; 36(12):1463–8.
4. Dayton P, Feilmeier M, Hirschi J, Lauwe M, Kauwe JS. Observed changes in radiographic measurements of the first ray after frontal rotation of the first metatarsal in a cadaveric foot model. J Foot Ankle Surg. 2014; 53(3):274–278.
5. Siddiqui NA, LaPorta GA. Minimally invasive bunion correction. Clin Podiatr Med Surg. 2018; 35(4):387–402.
6. Siddiqui NA, LaPorta G, Walsh AL, Abraham JS, Beauregard S, Gdalevitch M. Radiographic outcomes of a percutaneous, reproducible distal metatarsal osteotomy for mild and moderate bunions: A multicenter study. J Foot Ankle Surg. 2019; 58(6):1215–ß1222.
