Key Insights On The Closing Base Wedge Osteotomy For Hallux Valgus
For patients with moderate to severe hallux valgus and a large intermetatarsal angle, proximal first metatarsal osteotomies may be indicated to achieve an appropriate amount of correction. The closing base wedge osteotomy is a reliable procedure resulting in a strong structural correction and is amenable to multiple fixation techniques. Loison first described and advocated the transverse closing base wedge osteotomy in 1901.1 Juvara modified the procedure in 1919, employing the oblique version of the closing base wedge osteotomy.2
Controversy has surrounded this procedure due to its relative difficulty and the possibility of associated complications. Some authors have described the closing base wedge osteotomy as technically demanding with little margin for error and have even called for its extinction and replacement with the Lapidus arthrodesis.3-7 Martin and Blitch described the difficulties in the execution of this procedure and presented alternatives to the closing base wedge osteotomy.4 The osteotomy requires precise wedge resection with preservation of the hinge at the medial cortex of the metatarsal. Once the wedge is resected, intraoperative alterations for over- and undercorrection of the intermetatarsal angle can be technically challenging.4
When the procedure first became popular, complications included first metatarsal elevatus, shortening, delayed bone healing and unstable fixation.4,7-11 However, with advances in surgical technique, fixation methods and adequate postoperative weightbearing instruction, outcomes have improved.8,12,13 The closing base wedge osteotomy is a powerful procedure that preserves first ray range of motion while correcting hallux valgus deformities that may not be amenable to distal metatarsal osteotomies.
The primary indication for the closing base wedge osteotomy is a rigid deformity with an intermetatarsal angle of 15 degrees or greater. A rigid deformity is not manually reducible in the transverse plane and indicates the need for an osteotomy that corrects the larger angular deformity. The closing base wedge osteotomy is more effective at correcting moderate to severe deformities in comparison to distal metatarsal osteotomies. This is because the proximal position of the osteotomy is closer to the apex of the deformity, permitting greater angular correction and a more rectus alignment. When it comes to an intermetatarsal angle of 15 degrees or greater, performing a distal metatarsal osteotomy or soft tissue procedure may result in undercorrection and a higher recurrence rate.14,15
Step-By-Step Pearls For The Closing Base Wedge Osteotomy
Make the skin incision along the dorsomedial surface of the first metatarsal and medial to the extensor hallucis longus tendon, extending proximally to the first metatarsocuneiform joint. Take care to identify and retract the branches of the medial dorsal cutaneous nerve that cross at the proximal aspect of the incision. Incise the deep fascia and expose the surface of the first metatarsal. Maintain the periosteum at the base of the metatarsal medially to preserve the vasculature at the osteotomy site.
There are differences among surgeons regarding resection of the medial eminence in hallux valgus surgery. Some surgeons have advocated correction of hallux valgus deformity without any consideration for the medial eminence.16,17 One can resect the eminence after performing the closing base wedge osteotomy but our best outcomes take advantage of the pre-surgical stability of the metatarsal, resecting the medial eminence prior to making the osteotomy.
Following resection of the medial eminence, direct attention to creating the arms of the closing base wedge osteotomy. Orientation of the osteotomy is crucial to the outcome because it dictates the relationship of the first metatarsal to the weightbearing surface of the medial column. Directing the apex of the closing base wedge osteotomy at the medial cortex without breaking through creates a hinge. Position the base of the wedge laterally and keep in mind that the amount of bone you resect should be directly proportional to the amount of correction required. When making the osteotomy, angle the cuts so the osteotomy base is wider plantarly than dorsally to prevent elevatus.
The two variations of the closing base wedge osteotomy include the transverse and oblique methods. The surgeon’s fixation preference determines the orientation of the osteotomy. One generally performs the closing base wedge osteotomy approximately 2 cm distal to the first metatarsocuneiform joint, leaving enough room for fixation. A Kirschner wire (K-wire) can provide an axis guide just lateral to the location of the anticipated hinge. One should insert the K-wire from dorsal to plantar, perpendicular to the weightbearing surface of the foot. The K-wire also serves to protect the hinge from inadvertent cutting of the medial cortex and the surgeon can remove it prior to reciprocal planing of the osteotomy.
The surgeon performs the transverse technique by making the proximal cut perpendicular to the longitudinal axis of the first metatarsal. Prior to making the osteotomy, one can use intraoperative fluoroscopy to determine the osteotomy site by applying a four-hole plate and marking the bone between the second and third holes of the plate. Then mark the proximal arm perpendicular to the long axis of the first metatarsal. Make the distal cut first because of the stability of the first metatarsal. Angle the cut in the transverse plane and make it converge medially with the marked proximal arm. Then make the proximal transverse cut perpendicular to the weightbearing surface along the previously marked area. This determines the final angle of the wedge. The amount of bone to resect depends on the degree of intermetatarsal angle correction necessary to correct the deformity. Templates are available as guides to determine the size of the wedge. After completing both cuts, gently feather the osteotomy at its apex until you can reduce it without breaking the medial hinge.
Ruch introduced the oblique version of the closing base wedge osteotomy because it produces a longer arm and decreases the amount of bone resection.18 The proximal cut is essential to the orientation of the osteotomy because it determines the angle of the osteotomy as well as the placement of fixation. Perform the distal cut first at an angle of 45 degrees to the long axis of the metatarsal. Then perform the proximal arm of the osteotomy, which should intersect the distal arm, creating a medial hinge. The angle of the wedge resected is directly proportional and slightly less than the intermetatarsal angle.
Recognizing The Importance Of The Hinge Concept For Multiple Plane Correction Of Structural Deformities
Christensen and colleagues concluded that the major stabilizing factor of the first metatarsal base osteotomy is the medial cortical hinge.19 They found that osteotomies with an intact hinge exhibited superior stiffness in comparison to osteotomies without a hinge.
The hinge concept is an important tool for correcting structural deformities in multiple planes and necessitates optimal guide orientation to prevent dorsiflexion and shortening of the first metatarsal.8,20 Excessive shortening and elevatus can lead to transfer metatarsalgia and painful calluses under the second metatarsal. The axis of rotation, amount of correction and final position of the metatarsal in weightbearing depend on the integrity of the hinge and size of the wedge. The greatest amount of motion will occur in the plane to which the axis is perpendicular. Essentially, plantarflexion of the first metatarsal will occur with a dorsomedial hinge and elevatus of the first metatarsal will occur with a plantar-medial hinge. Making the osteotomy perpendicular to the first metatarsal will result in dorsiflexion of the first metatarsal. Therefore, we advocate making the osteotomy perpendicular to the weightbearing surface of the foot, ensuring that the first metatarsal will remain parallel with the weightbearing surface.
After removal of the resulting wedge and reduction of the intermetatarsal angle, temporarily fixate the osteotomy with a K-wire. Place the foot into simulated weightbearing and load the foot by using a metallic flat cover from an instrument tray. Using fluoroscopy, take a lateral image during simulated weightbearing to ensure proper alignment of the metatarsal and that no elevatus has occurred.
Emerging Concepts With Fixation
Once there is satisfactory alignment and the osteotomy is stable with a K-wire or a bone clamp, one can apply permanent fixation. Fixation techniques for this osteotomy include single screw, double screw, neutralization plate, locking plate and even intramedullary fixation. The two-screw technique employs a compression screw and an anchor screw. Orient the compression screw perpendicular to the osteotomy site. Place the anchor screw perpendicular to the long axis of the first metatarsal to prevent shortening and rotation if the hinge fails.
A variation of the two-screw technique is to insert a screw from the distal medial aspect of the first metatarsal into the intermediate cuneiform and a second screw from the distal lateral aspect of the first metatarsal into the medial cuneiform. This increases stability across the osteotomy site, especially in soft bone, by crossing additional cortices.
For added stability, our preferred method of fixation is an interfragmentary screw with a neutralization plate. Researchers have found that plate fixation is superior to a single screw or K-wire construct.21 This method provides good stability and we especially recommend it if one loses the integrity of the hinge. For this technique, the surgeons can use a 3.0 or 4.0 interfragmentary screw to compress the osteotomy. One usually inserts the interfragmentary screw from distal medial to proximal lateral, crossing perpendicular to the osteotomy. Attach a four-hole, quarter tubular bone plate to the dorsomedial aspect of the metatarsal with 2.7 mm cortical bone screws. Place the screw distal to the osteotomy eccentrically to provide additional compression. If necessary, use an axial loading screw to augment the fixation. One can insert this proximal dorsal to distal plantar and avoid penetrating the plantar cortex in order to prevent violation of the sesamoids.
Following the procedure, place the patient into a below-knee cast for three weeks and give him or her instructions to be non-weightbearing. The patient subsequently transitions into a controlled ankle motion (CAM) boot and stays non-weightbearing until radiographic signs of osseous union are evident. The patient can then begin physical therapy and slowly transition to full weightbearing.
Complications associated with the closing base wedge osteotomy include shortening of the first metatarsal, metatarsal elevatus, transfer metatarsalgia, delayed union and failure of fixation. Most complications occur because of poor technique, failure of fixation and early weightbearing.
Studies have shown that average shortening of the metatarsal ranges from 1.7 mm to 5 mm.10,11,22-24 Excessive shortening of the first metatarsal can lead to increased pressure on the lesser metatarsal heads, which leads to pain, callus formation and stress fractures.20 Jung and coworkers studied the effects of shortening and elevation of the first metatarsal osteotomy, and concluded that it significantly increased plantar pressures under the lesser metatarsal heads.25 Despite these findings, Banks and colleagues studied shortening of the first metatarsal following the closing base wedge osteotomy and concluded that the reduction in length of the first metatarsal is not excessive, and that elevatus is the major factor that leads to most complications.11
Unlike the Lapidus procedure, which has a high non-union rate of up to 12 percent, the closing base wedge osteotomy has minimal issues with bone healing.3,13,26,27 Multiple studies have found no complications in osteotomy healing with no incidence of delayed union or non-union.22,24,28 Another advantage of this procedure is a low recurrence rate, especially in comparison with distal metatarsal osteotomies.3,29 Dreeben and Mann concluded that if one corrects the intermetatarsal angle to below 10 degrees using a metatarsal base osteotomy, patients with a moderate to severe deformity would not have a recurrence.30
Ten Keys For Successful Closing Base Wedge Osteotomies
1. Select the appropriate patient who can follow postoperative instructions.
2. Evaluate for hypermobility at the first metatarsocuneiform joint.
3. Determine if first metatarsal elevatus is present.
4. If the patient has a metatarsus adductus foot structure, it may be necessary to create a slightly negative intermetatarsal angle to ensure adequate correction.
5. Select appropriate fixation for the osteotomy.
6. Select the type of osteotomy (transverse or oblique).
7. During dissection, safeguard the periosteum at the medial aspect of the metatarsal.
8. Perform the osteotomy in the correct angle so one can correct the intermetatarsal angle and not create metatarsal elevatus. Do not break the medial cortex.
9. Temporarily stabilize the osteotomy with a K-wire and take a lateral X-ray using the C-arm with the foot loaded. This allows you to visualize the medial column for signs of elevatus.
10. Insert fixation. If you are using a neutralization plate, insert the lag screw first, remove the K-wire and attach the plate.
The closing base wedge osteotomy is an effective procedure that requires adequate preparation and surgical skill to create successful and reproducible results. The osteotomy allows for greater reduction of moderate to severe intermetatarsal angles in rigid first rays that are not possible with distal metatarsal procedures. Performing the surgery correctly and with utilization of the hinge concept can prevent complications, and facilitate favorable and reproducible outcomes.
Dr. Mansour is a second-year foot and ankle surgical resident at Beaumont Hospital-Wayne in Wayne, Mich.
Dr. Fallat is the Program Director of the foot and ankle surgical residency at Beaumont Hospital-Wayne in Wayne, Mich. He is a Fellow of the American College of Foot and Ankle Surgeons.
- Loison M. Note sur le traitment chirurgical du hallux valgus d’apres l’etude radiographique de la deformation. Bull Soc Chir Paris. 1901; 27:528-531.
- Juvara E. Nouveau procédé pour la cure radicale du hallux valgus. Presse Méd. 1919; 40:395-397.
- Myerson M. Metatarsocuneiform arthrodesis for treatment of hallux valgus and metatarsus primus varus. Orthopedics. 1990; 13(9):1025-1031.
- Martin DE, Blitch EL. Alternatives to the closing base wedge osteotomy. Clin Podiatr Med Surg. 1996; 13(3):515-531.
- DeHeer P. Is the closing base wedge osteotomy extinct? Podiatry Today DPM Blog. Available at http://www.podiatrytoday.com/blogged/is-the-closing-base-wedge-osteotomy... . Published Feb. 10, 2010. Accessed 15 Sept 2016.
- Baravarian B, Green DR, Kim P. Point-counterpoint: should the Lapidus replace the closing base wedge osteotomy? Podiatry Today. 2004; 17(10):52–60.
- Trnka HJ, Muhlbauer M, Zembsch A, et al. Basal closing wedge osteotomy for correction of hallux valgus and metatarsus primus varus: 10-to 22-year follow-up. Foot Ankle Int. 1999; 20(3):171-177.
- Mothershed RA. Proximal osteotomies of the first metatarsal. In (Southerland JT, ed.): McGlamry’s Comprehensive Textbook of Foot and Ankle Surgery, Fourth Edition, Lippincott Williams & Wilkins, Philadelphia, 2013, pp. 290–301.
- Zlotoff H. Shortening of the first metatarsal following osteotomy and its clinical significance. J Am Podiatr Assoc. 1977; 67(6):412-426.
- Schuberth JM, Reilly CH, Gudas CJ. The closing wedge osteotomy. A critical analysis of first metatarsal elevation. J Am Podiatr Med Assoc. 1984; 74(1):13-24.
- Banks AS, Cargill RS 2nd, Carter S, Ruch JA. Shortening of the first metatarsal following closing base wedge osteotomy. J Am Podiatr Med Assoc. 1997; 87(5):199-208.
- Haas Z, Hamilton G, Sundstrom D, Ford L. Maintenance of correction of first metatarsal closing base wedge osteotomies versus modified Lapidus arthrodesis for moderate to severe hallux valgus deformity. J Foot Ankle Surg. 2007; 46(5):358-365.
- Nigro JS, Greger GM, Catanzariti AR. Closing base wedge osteotomy. J Foot Ankle Surg. 1990; 30(5):494-505.
- Sammarco GJ, Idusuyi OB. Complications after surgery of the hallux. Clin Orthop Rel Res. 2001; 391:59-71.
- Austin DW, Leventen EO. A new osteotomy for hallux valgus: a horizontally directed” V” displacement osteotomy of the metatarsal head for hallux valgus and primus varus. Clin Orthop Rel Res. 1981; 157:25-30.
- Klemola T, Leppilahti J, Kalinainen S, et al. First tarsometatarsal joint derotational arthrodesis—a new operative technique for flexible hallux valgus without touching the first metatarsophalangeal joint. J Foot Ankle Surg. 2014; 53(1):22-28.
- Dayton P, Kauwe M, DiDomenico LA, et al. Quantitative analysis of the degree of frontal rotation required to anatomically align the first metatarsal phalangeal joint during modified tarsal-metatarsal arthrodesis without capsular balancing. J Foot Ankle Surg. 2016; 55(2):220-225.
- Ruch JA. Current use of the oblique base wedge osteotomy in hallux valgus surgery. Reconstructive Surgery in the Foot and Leg Update. Podiatry Institute Publishing, Tucker, GA, 1994, pp. 128-132.
- Christensen JC, Gusman DN, Tencer AF. Stiffness of screw fixation and role of cortical hinge in the first metatarsal base osteotomy. J Am Podiatr Med Assoc. 1995; 85(2):73-82.
- Nichols AA, Jimenez DL, Ruch JA. The closing base wedge osteotomy revisited. Reconstructive Surgery of the Foot & Leg Update, Podiatry Institute Publishing, Tucker, GA, 2003, pp. 96-101.
- Jones C, Coughlin M, Petersen W, et al. Mechanical comparison of two types of fixation for proximal first metatarsal crescentic osteotomy. Foot Ankle Int. 2005; 26(5):371-374.
- Seiberg M, Felson S, Colson JP, et al. 1994 William J. Stickel Silver Award. Closing base wedge versus Austin bunionectomies for metatarsus primus adductus. J Am Podiatr Med Assoc. 1994; 84(11):548-563.
- Nyska M, Trnka HJ, Parks BG, Myerson MS. Proximal metatarsal osteotomies: a comparative geometric analysis conducted on sawbone models. Foot Ankle Int. 2002; 23(10):938-945.
- Higgins KR, Shebetka KA, Lavery LA. Review of the effect of fixation on complication rate in the base wedge osteotomy. J Am Podiatr Med Assoc. 1996; 86(7):327-330.
- Jung HG, Zaret DI, Parks BG, Schon DL. Effect of first metatarsal shortening and dorsiflexion osteotomies on forefoot plantar pressure in a cadaver model. Foot Ankle Int. 2005; 26(9):748-753.
- McInnes BD, Bouché RT. Critical evaluation of the modified Lapidus procedure. J Foot Ankle Surg. 2001; 40(2):71-90.
- Saffo G, Wooster MF, Stevens M, et al. First metatarsocuneiform joint arthrodesis: a five-year retrospective analysis. J Foot Surg. 1988; 28(5):459-465.
- Pontious J, Mahan MT, Carter S. Characteristics of adolescent hallux abducto valgus. A retrospective review. J Am Podiatr Med Assoc. 1994; 84(5):208-218.
- Lagaay PM, Hamilton GA, Ford LA, et al. Rates of revision surgery using Chevron-Austin osteotomy, Lapidus arthrodesis, and closing base wedge osteotomy for correction of hallux valgus deformity. J Foot Ankle Surg. 2008; 47(4):267-272.
- Dreeben S, Mann RA. Advanced hallux valgus deformity: long-term results utilizing the distal soft tissue procedure and proximal metatarsal osteotomy. Foot Ankle Int. 2006; 17(3):142-144.