DEFINITION

Recurrent hallux valgus is a partial or complete return of valgus deformity at the first metatarsophalangeal (MTP) joint after surgical correction.

Metatarsus primus varus is an increase in the 1-2 intermetatarsal angle due to obliquity or hypermobility of the first tarsometatarsal (TMT) joint.

 

 

ANATOMY

 

The first TMT joint is 27 to 30 mm deep and irregularly shaped (FIG 1A).

 

The dorsalis pedis artery and deep peroneal nerve are just lateral to the extensor hallucis longus tendon (FIG 1B).

 

The two heads of the adductor hallucis muscle converge to a single tendon and insert on the lateral sesamoid at the first MTP joint.

 

The sesamoids are contained in the capsuloligamentous complex of the MTP joint.

 

The dorsal medial cutaneous branch of the superficial peroneal nerve runs along the dorsal medial aspect of the first MTP joint.

 

The plantar medial cutaneous branches of the medial plantar nerve run along the plantar aspect of the first MTP joint near the articulations of the sesamoids.

 

PATHOGENESIS

 

Recurrence of hallux valgus is most often due to an improperly chosen initial procedure or improper surgical technique.

 

 

 

FIG 1 • A. Lateral view of the first TMT joint. The joint is an average of 30 mm deep. B. The extensor hallucis longus over the TMT joint. The dorsalis pedis and deep peroneal nerve are just lateral to the tendon.

 

 

Less frequently, factors such as poor bone or tissue quality, infection, patient noncompliance, and instrumentation failure can lead to recurrent hallux valgus.

 

A major cause of recurrent hallux valgus is unrecognized metatarsus primus varus.

 

If uncorrected, metatarsus primus varus creates a valgus moment at the first MTP joint.

 

An intact adductor hallucis or a tight lateral joint capsule will exacerbate the valgus moment.

 

NATURAL HISTORY

 

Some partial recurrences of hallux valgus may be tolerable with nonoperative treatment.

 

 

If there is an uncorrected metatarsus primus varus, the deformity will most likely progress over time. The medial prominence can result in pain, tenderness, and an overlying bursitis.

 

Progressive deformity often leads to second toe overload and, ultimately, to arthritis at both the first and second TMT joints.

 

Lesser metatarsal overload, whether due to shortening of the first metatarsal or subluxation of the sesamoids, is a common reason for secondary surgery.

 

Arthritis can develop at the sesamoid-first metatarsal articulations.

 

Prolonged hallux valgus, especially with an incongruent joint, can lead to degenerative changes at the first MTP joint.

 

 

10

 

 

 

FIG 2 • Picture after previous bilateral distal bunion procedures. The left side is 6 months after revision with a Lapidus procedure and the right side is preoperative.

 

PATIENT HISTORY AND PHYSICAL FINDINGS

 

 

Patients report valgus deformity at the first MTP joint that is either recurrent or was never fully corrected (FIG 2). The examiner should evaluate for symptoms associated with metatarsus primus varus:

 

Hypermobility of the first TMT joint4

 

 

Mobility of the first TMT joint is tested by holding the lesser metatarsal heads stable with one hand while passively dorsiflexing the first metatarsal head.

 

Hypermobility has been defined as elevation of the first metatarsal head more than 5 to 8 mm above the level of the second metatarsal head (FIG 3).

 

Hypermobility at the TMT joint creates a valgus moment at the MTP joint, which may contribute to failure of distal hallux valgus correction.

 

 

 

FIG 3 • A,B. First TMT hypermobility.

 

 

Degenerative changes at the first TMT joint

 

 

Tenderness at the joint line

 

 

Osteophytes at the dorsal aspect of the joint Second metatarsal overload

 

 

Patients may report feeling as if there is a rock in their shoe. Tenderness under the second MTP joint

 

 

Callosity or ulceration under the second MTP joint Claw toe deformity3 (FIG 4)

 

 

Passive correction of the metatarsus primus varus may reduce the hallux valgus deformity. The examiner should check for lesser toe overload.

 

The medial lesser toes should be inspected for claw toe or hammer toe deformity, overlap, large plantar callus, or plantar ulcers. The plantar surface of the MTP joints is palpated for tenderness. The proximal phalanx is translated to evaluate for instability of the MTP joint.

 

Lesser toe overload is often associated with hypermobility of the first TMT joint or a dorsiflexion deformity of the first ray.

 

Range of motion of the first MTP joint with the hallux valgus deformity corrected is an indication of expected motion after surgical correction. Severely limited motion may be an indication for a fusion of the MTP joint.

 

 

In general, the more severe the deformity, the greater the pronation of first MTP joint on weight bearing.5 Patients are evaluated for other potential causes of the recurrent deformity:

 

Infection

 

Failure of fixation

 

 

Generalized ligamentous laxity Osteoporosis

IMAGING AND OTHER DIAGNOSTIC STUDIES

 

Anteroposterior (AP), lateral, and oblique weight-bearing radiographs of the foot should be obtained and evaluated for the following:

 

 

 

Surgical changes from the initial surgery, including any retained instrumentation Congruency of first MTP joint

 

 

Plantarflexion of the first ray Hallux valgus angle

 

11

 

 

 

FIG 4 • A,B. Claw toe deformity.

 

 

 

 

FIG 5 • Plantar gapping of the first TMT joint as well as dorsal translation of the first metatarsal on weightbearing radiographs.

 

 

Angle between long axes of first metatarsal and proximal phalanx

 

Normal is less than 15 degrees.

 

1-2 intermetatarsal angle

 

 

 

Angle between long axes of first and second metatarsals Normal angle is less than 9 degrees.

 

Distal metatarsal articular angle (DMAA)

 

 

 

Angle between long axis of metatarsal shaft and base of distal metatarsal joint surface Normal is less than 15 degrees.

 

Radiologic signs of metatarsus primus varus

 

 

Increased 1-2 intermetatarsal angle

 

Plantar gap at first TMT joint on weight-bearing lateral image (FIG 5)

 

Claw toe deformity

DIFFERENTIAL DIAGNOSIS

Loss of fixation Generalized tissue laxity Infection

 

 

NONOPERATIVE MANAGEMENT

 

Shoe wear modification

 

 

 

Wide toe box Low heels

 

Orthotics

 

 

 

Medial arch support for associated pes planus Metatarsal pad for associated second toe overload

 

Activity modification

 

SURGICAL MANAGEMENT

 

It is important to determine what the previous procedure entailed.

 

Seldom can a failed distal or shaft procedure be revised with another such procedure.

 

Most salvage procedures rely on stabilizing the base of the first metatarsal. It is also possible to get more angular correction at the base of the metatarsal.

 

Preoperative Planning

 

Retained instrumentation may need to be removed.

 

The age and position of previous incisions must be taken into account.

 

The surgeon must take into account the need for shortening of the lesser metatarsals, correction of claw toes,

and the addition of an Akin phalangeal osteotomy to correct concurrent deformities.

 

Positioning

 

The patient is positioned supine.

 

A tourniquet is placed on the proximal thigh.

 

The foot should be positioned to allow access for intraoperative imaging.

 

Approach

 

The approach depends on the procedure to be performed.

 

TECHNIQUES

• Case Example 1

Background

 

 

 

A 33-year-old woman post distal bunion correction (details unknown) Persistent symptomatic hallux valgus deformity (TECH FIG 1A) Has failed nonoperative management of this problem

 

Motion well preserved in first MTP joint

 

 

Overload phenomenon second metatarsal head but no deformity in second toe Radiographs (TECH FIG 1B,C)

 

 

 

Prior distal procedure to first metatarsal head Increased 1-2 intermetatarsal angle Increased hallux valgus angle

 

Questionable increase in the DMAA

 

 

Relatively short first metatarsal compared to second metatarsal No obvious second toe deformity

Distal Soft Tissue Procedure

 

Dorsomedial approach, because that is what was used previously, but extended more proximally to perform the proximal osteotomy

 

Lateral release also performed through a separate first web space incision

 

This puts the blood supply to the metatarsal head at risk if a simultaneous distal osteotomy is performed.

 

Medial and lateral soft tissues released

 

 

Complete disruption of the intraosseous blood supply to the head Therefore, lateral release must be performed judiciously.

 

Distal to the lateral capsule that contains vessels to the metatarsal head

 

With the exposure, the actual (not radiographic) DMAA can be evaluated (TECH FIG 2).

 

 

12

 

 

 

TECH FIG 1 • Preoperative evaluation of 33-year-old woman with failed prior bunion correction. A. Clinical view. B. AP weight-bearing radiograph. C. Lateral weightbearing foot x-ray.

Proximal Osteotomy

 

In this case, a proximal medial opening wedge osteotomy was performed.

 

It may not lengthen the first metatarsal, but the risk of shortening is diminished.

 

All traditional osteotomies, when they heal, shorten slightly; however, an opening wedged osteotomy may not have that tendency.

 

The goal was to preserve length, given that the patient was experiencing a second metatarsal head overload.

 

Given the osteotomy is performed from the medial side and the lateral cortex is left intact, it also has less of a tendency to develop a dorsiflexion malunion.

 

Fluoroscopy is used to determine the trajectory of the osteotomy and the depth of the saw cut (TECH FIG 3A).

 

We make the osteotomy in the oblique plane to increase the surface area and target the more proximal aspect of the lateral metatarsal base where the cortex is wider and the soft tissue support is greater (TECH FIG 3B).

 

 

 

TECH FIG 2 • Suggestion of increased DMAA (metatarsal head oriented laterally relative to first metatarsal shaft). Note lateral release performed through a separate dorsal first web space incision.

 

 

The saw cut approaches the lateral cortex without violating it.

 

 

The osteotomy is gently opened with a triple osteotome technique (TECH FIG 3C-E). The medial plate with spacer is placed and secured with screws (TECH FIG 3F).

 

One of the proximal screws may be placed across the osteotomy to lend further support to the construct (TECH FIG 3G).

 

We typically bone graft the osteotomy with bone graft harvested from the lateral calcaneus.

Distal Biplanar Chevron Osteotomy

 

The proximal osteotomy increases the already greater than physiologic DMAA.

 

Furthermore, greater correction is warranted in this revision case with considerable hallux valgus deformity.

 

We check a pin under fluoroscopic guidance to determine the orientation of the osteotomy (see TECH FIG 3G).

 

A distal biplanar chevron osteotomy (Reverdin-Green osteotomy) affords greater correction, satisfactory stability, and a simple means of correcting the increased DMAA (TECH FIG 4A).

 

The osteotomy has a long plantar limb that provides large surface area for healing and excellent contact for screw placement (TECH FIG 4B).

 

The short dorsal limb may be modified with a medial closing wedge osteotomy that allows correction of the increased DMAA (TECH FIG 4C-G).

 

 

We routinely secure this osteotomy with a single screw placed in lag fashion (TECH FIG 4H). The medial prominence is resected (TECH FIG 4I).

Akin Osteotomy

 

We typically employ an oblique Akin osteotomy (TECH FIG 5A-H).

 

Abundant surface area for healing

 

Screw can be placed from proximal to distal perpendicular to the osteotomy.

 

Some rotation is still possible to correct the pronation deformity.

 

 

13

 

 

 

 

TECH FIG 3 • Proximal first metatarsal opening wedge osteotomy. A. Fluoroscopic view of reference pin to guide saw blade trajectory. B. Microsagittal saw for osteotomy. (Note saw blade is perpendicular to metatarsal shaft.) C. Triple osteotome technique for opening the osteotomy. D. Fluoroscopic view of triple osteotome technique (note lateral cortex intact). E. Close-up of triple osteotome technique. F. Initial positioning of medial opening wedge plate. G. Reference pin to orient osteotomy (note final fixation of proximal osteotomy).

Closure

 

The capsule is reapproximated (TECH FIG 6A).

 

The correction of the axial deformity is achieved with the bony realignment, not the capsular closure (TECH

FIG 6B).

 

However, we attempt to correct pronation by suturing the distal plantar capsule to proximal dorsal capsule.

 

 

Motion should be maintained after the capsule is closed (TECH FIG 6C,D). Final fluoroscopic images to confirm alignment is appropriate.

 

We strive for a slight overcorrection because the tendency is for recurrence, particularly in a revision procedure (TECH FIG 6E).

 

Postoperative management is the same as for other bunion procedures (see FIG 6).

 

 

14

 

 

 

TECH FIG 4 • Biplanar distal chevron osteotomy. A. Osteotomy marked on metatarsal. B. Long plantar limb.

C. Short dorsal limb. D-I. Correcting the increased DMAA using a medially based wedge of dorsal limb. D. Initial cut. E. Second cut. F. Wedge completed. G. Wedge extracted. H. Distal fragment translated laterally, oriented properly, and secured with a screw to the proximal fragment. I. Medial prominence resected.

 

 

15

 

 

 

TECH FIG 5 • Akin osteotomy (medially based wedge resection of proximal phalanx). A. Fluoroscopic view of reference pin to guide saw cut. B. Initial cut. C. Second cut. D. Osteotomy open. E. Osteotomy closed. F. Fluoroscopic view of guide pin for screw fixation (note that it is perpendicular to the closed osteotomy). G. Lateral fluoroscopic view confirming that pin is contained in the proximal phalanx. H. Screw insertion with osteotomy reduced.

 

 

16

 

 

 

TECH FIG 6 • Closure. A. Capsule reapproximated. B. Fluoroscopic view confirms that correction is satisfactory. C,D. Adequate motion confirmed. E. Clinical view on operating room table after skin closure.

• Lapidus Procedure (First Tarsometatarsal Fusion)

  First Tarsometatarsal Joint Preparation

   

  Make a 6-cm incision over the dorsum of the first TMT joint.

   

  Identify the interval between the extensor hallucis longus and the extensor hallucis brevis.

   

  Incise the capsule over the first and second TMT joints and expose the joints. Release the capsule all around the medial and lateral borders of the joint to allow adequate exposure (TECH FIG 7A,B).

   

  Remove the cartilage from the first TMT joint using small osteotomes and small curettes.

   

  If the first metatarsal is shortened, only cartilage should be removed.

   

   

  If the first metatarsal is long, a small laterally based wedge can be removed from the medial cuneiform. A small plantarly based osteotomy can be performed to plantarflex the first metatarsal if necessary.

   

  Use a 2.0-mm drill to perforate the subchondral surfaces of the joint.

   

  Expose and decorticate the medial aspect of the base of the second metatarsal and the lateral aspect of

  the base of the first metatarsal (TECH FIG 7C).

  Lateral Soft Tissue Release

   

  Make a 2-cm incision in the first web space.

   

  Use blunt dissection to identify the adductor hallucis tendon.

   

  Identify and protect the terminal branch of the deep peroneal nerve.

   

   

  Incise the adductor hallucis tendon at the lateral aspect of the fibular sesamoid. Incise the lateral capsule longitudinally to allow reduction of the sesamoids.

   

  Force the MTP joint into varus to complete the lateral release.

  Medial Exostectomy

   

   

  Make a direct medial incision over the first MTP joint. Incise the capsule in line with the incision.

   

  A wedge of capsule can be removed to facilitate reduction of the sesamoids.

   

   

  17

   

   

   

   

  TECH FIG 7 • A,B. With the initial exposure, only the dorsal 10 to 15 mm of the TMT joint is visualized. A small lamina spreader or distractor is required to expose the plantar half of the joint. This is a requirement of the procedure to avoid fusing the joint in dorsiflexion. With the distractor in place, the medial aspect of the base of the second metatarsal can be denuded of soft tissue to prepare for intermetatarsal fusion. C. Decortication of the lateral aspect of the base of the first metatarsal and the medial aspect of the second metatarsal to allow fusion.

   

   

  Remove any residual prominence. Most of this was probably done with the primary procedure.

  Fixation of the First Tarsometatarsal Joint

   

  Reduce the first metatarsal parallel to the second.

   

  Confirm that the first metatarsal is parallel and properly rotated.

   

  Place a 3.5-mm cortical screw across the first TMT joint from proximal to distal using a compression technique.

   

  Place a second 3.5-mm cortical screw from the medial aspect of the base of the first metatarsal into the base of the second metatarsal.

   

   

   

  TECH FIG 8 • Screw placement for a salvage of a failed distal procedure. A. The first metatarsal length was well preserved with the initial procedure. B. The first metatarsal length was such that a second metatarsal shortening was indicated to limit second metatarsal overload.

   

   

  Bone graft obtained from removal of the medial prominence can be placed in the 1-2 intermetatarsal space to augment the fusion.

   

  Use intraoperative imaging to confirm the position of the screws and reduction of the deformity (TECH FIG 8).

  Capsular Repair and Wound Closure

   

  Repair the medial capsulectomy with absorbable suture.

   

   

  It should not be necessary to overtighten the capsule to maintain the alignment of the MTP joint. Close the wounds in layers.

   

  18

• Ludloff Metatarsal Osteotomy

   

  This procedure could be used instead of a Lapidus procedure.

   

  Indications

   

  Smokers or patients with other medical issues that would delay a TMT fusion

   

  Patients unable to be non-weight bearing for an extended period (eg, obesity, rheumatoid arthritis, contralateral joint problems, shoulder problems)

   

  Patients with less severe deformities: correction achieved will be 8 to 16 degrees

   

   

   

  TECH FIG 9 • Ludloff osteotomy. A. A long oblique cut is made from dorsal-proximal to plantar-distal. B. After osteotomy and before rotation. The proximal screw is placed first, from dorsal to plantar. C. The distal (capital) portion of the metatarsal is now rotated laterally to correct the intermetatarsal angle before the second screw is added. D. This is followed by the second screw, usually from plantar to dorsal, and insertion of a K-wire.

   

  Technique1,6

   

  Make an incision over the medial aspect of the first metatarsal.

   

  The optimal osteotomy starts on the dorsum, 1 cm from the TMT joint, and extends distal and plantar to a point just proximal to the sesamoid articulation.

   

  The osteotomy should be angled 10 degrees plantarly in the coronal plane (TECH FIG 9A).1,6

   

  The axis of rotation should be within 5 mm from the proximal end of the osteotomy.

   

  Insert the proximal screw first. It is usually done from dorsal to plantar. This serves as the axis of rotation of the distal capital fragment.

   

  Once the desired reduction is obtained, a second screw is inserted (TECH FIG 9B-D).

   

   

  19

• Dorsal Opening Wedge Osteotomy

   

  Indications

   

  Dorsal malunion of a proximal metatarsal osteotomy

   

  Dorsal malunion or nonunion of a Lapidus procedure (TECH FIG 10)

   

  Technique

   

  Make a 6-cm incision over the dorsum of the first metatarsal base.

   

   

   

  Identify the interval between the extensor hallucis longus and the extensor hallucis brevis. Perform an osteotomy 1.5 cm distal to the first TMT joint, leaving the plantar cortex intact. For a failed Lapidus procedure, the osteotomy is done through the previous fusion site.

   

   

   

  TECH FIG 10 • Dorsiflexion malunion of a proximal metatarsal osteotomy.

   

   

  Place a triangular, tricortical bone graft with the wide surface placed dorsally to plantarflex the first metatarsal.

   

  Either an allograft or an iliac crest autograft can be used.

   

  A small distractor is helpful in distracting and keeping the osteotomy open.

   

  Fix the osteotomy with a small fragment screw from distal to proximal across the bone graft or with a dorsal plate that spans the bone graft (TECH FIG 11).

  Wound Closure and Postoperative Care

   

  Close the wound in layers.

   

  Apply a well-padded short-leg cast in the operating room.

   

   

  The patient may be partial weight bearing on the heel only for 6 to 8 weeks. At 2 weeks, the cast is removed to allow suture removal and a wound check.

   

  A new short-leg cast or a cast boot is applied for another 4 to 6 weeks until bony healing is seen on radiographs.

   

   

   

  TECH FIG 11 • Dorsal open wedge osteotomy and bone grafting of a malunion of a Lapidus procedure.

• Great Toe Fusion

   

  Indications

   

   

  Severe degenerative changes of the first MTP joint secondary to previous bunion surgery Avascular necrosis of the metatarsal head

   

  Severe recurrence of a hallux valgus in a rheumatoid patient

   

• Case Example 2

Background and Preoperative Evaluation

 

A 62-year-old woman with pain at the right first TMT joint 15 months after right hallux valgus correction with modified Lapidus procedure

 

 

Dorsomedial incision over first TMT joint Minimal residual hallux valgus

 

Tender over first TMT joint

 

Minimal pain with first MTP joint range of motion

 

Radiographs (TECH FIG 12A,B) showed step plate designed for correction with Lapidus procedure and suggest nonunion.

 

Computed tomography (CT) (TECH FIG 12C) confirmed nonunion and showed no bridging trabeculation at first TMT arthrodesis site.

 

20

 

 

 

TECH FIG 12 • A 62-year-old woman presented with continued pain at first TMT joint 15 months after right hallux valgus correction with modified Lapidus procedure. A. Weight-bearing AP radiograph. Although plate appears broken, it is not; rather, this is a dedicated Lapidus step plate designed to correct deformity. B. Weight-bearing lateral radiograph. C. Sagittal CT scan confirming first TMT joint nonunion.

Exposure and Joint Preparation

 

Dorsomedial approach

 

 

Superficial peroneal nerve sensory branch to the hallux protected Extensor hallucis longus tendon retracted

 

Hardware exposed and removed (TECH FIG 13)

 

 

First TMT joint is exposed and residual cartilage and fibrous tissue is débrided. Joint preparation for the subchondral bone of the first TMT joint

 

 

Satisfactory bony apposition at arthrodesis site +/− bone graft In the majority or revision cases, bone graft is used.

 

Ensure that the first metatarsal and sesamoids are not elevated relative to the second metatarsal head.

 

Correct hallux valgus.

Fixation

 

During provisional fixation, ensure that the first metatarsal and sesamoids are not elevated relative to the second metatarsal head.

 

Be sure that the intermetatarsal ankle is corrected prior to definitive fixation (TECH FIG 14A).

 

 

 

TECH FIG 13 • A. Dorsomedial incision to identify plate. B. Plate being extracted. Note threads of lag screw. C. Plate removed and separate lag screw threads visible in the first cuneiform.

 

 

Typically, two compression screws are used, one from distal to proximal and one from proximal to distal.

 

 

May be less effective in revision TMT joint arthrodesis Plating (TECH FIG 14B)

 

A more stout plate with multiple fixation options

 

Some plating systems permit compression (TECH FIG 14C,D).

 

May be considered but with caution because compression through a dorsal plate may create plantar gapping at the first TMT joint and elevation of the first ray

 

Medial compression, if not applied carefully, may create some loss of correction.

 

With a lag screw placed initially across the TMT joint, compression through the supplemental plate is less likely to create gapping (TECH FIG 14E).

 

Final fluoroscopic evaluation should demonstrate satisfactory alignment even prior to the medial capsular closure (TECH FIG 14F-H).

 

Medial capsular closure.

Postoperative Care

 

 

Bunion strapping and protected weight bearing for 6 to 8 weeks Follow-up to confirm satisfactory healing (see FIG 7).

 

21

 

 

 

TECH FIG 14 • After joint débridement and preparation of subchondral bone, surfaces opposed and provisionally pinned. A. AP fluoroscopic view. B. New dorsomedial plate placed and provisionally pinned. C. Compression device placed. Note that compression through a plate must be carefully applied, as it could create gapping at the arthrodesis site on the opposite side from the plate. D. Fluoroscopic confirmation of satisfactory plate position: AP view. E. Fluoroscopic lateral view confirming that first metatarsal is not elevated. F-H. Definitive fixation. F. Fluoroscopic AP view. After the lag screw was placed, the screws in the plate were secured. G. Intraoperative view of the secured plate. Prior to definitive fixation, the sesamoids and first metatarsal head were noted to be balanced with the second metatarsal head, that is, first ray dorsiflexion was avoided. H. Satisfactory clinical alignment in the AP plane.

• Case Example 3

Background and Preoperative Evaluation

 

 

A 33-year-old woman with recurrent/persistent left hallux valgus Prior proximal metatarsal osteotomy

 

Prior distal metatarsal osteotomy and Akin proximal phalanx osteotomy

 

 

Midaxial medial incision over first MTP joint Hallux valgus

 

Mild stiffness to first MTP joint with dorsiflexion to 60 degrees

 

Minimal pain with first MTP joint range of motion and no mechanical symptoms

 

 

22

 

 

 

 

TECH FIG 15 • A 33-year-old woman with recurrent/persistent hallux valgus after two prior procedures.

A. AP view. Note incongruent hallux valgus but with an increased DMAA is suggested (although DMAA cannot be accurately determined radiographically). B. Lateral view.

 

 

 

Although long second toe, no symptoms First TMT joint stable to stress testing

 

Radiographs showed recurrent/persistent asymmetric hallux valgus (TECH FIG 15).

 

Although difficult to determine on preoperative radiographs, there may be an increased DMAA.

Exposure and Joint Preparation

 

Midaxial medial approach

 

 

Superficial peroneal nerve sensory branch to the hallux protected Midaxial medial capsulotomy (TECH FIG 16A,B)

 

 

 

TECH FIG 16 • A. Medial midaxial approach with dorsal capsule and periosteum elevated. B. Plantar capsule and periosteum elevated. C. Intraoperative view from distal to proximal confirms increased DMAA.

D. In most cases, the suspensory ligament between the lateral capsule and the lateral sesamoid may be released through the joint from the medial side. E. In this case, dense lateral scarring necessitated a traditional lateral release of the suspensory ligament and the scarred adductor tendon, along with lateral capsular fenestration.

 

 

On clinical examination, suggestion of increased DMAA (TECH FIG 16C)

 

Lateral release of the suspensory ligament between the lateral capsule and lateral sesamoid (TECH FIG 16D)

 

 

Typically allows for a “buttonhole” so that the metatarsal head can center on the sesamoids In this revision case, particularly scarred

 

Therefore, traditional first web space lateral release added to release lateral scarring and contracted lateral structures (TECH FIG 16E)

 

 

23

 

 

 

TECH FIG 17 • Orienting the scarf osteotomy. A. Two parallel guide pins placed as reference for the osteotomy. B. Fluoroscopic view of the guide pins.

Reference Pins to Guide Osteotomy

 

The distal pin marking the distal extent of osteotomy should be immediately proximal to the articular surface.

 

This allows for the widest portion of the metatarsal, the head, to offer maximal support to the osteotomy, thereby limiting the risk of troughing.

 

Pins should be parallel to allow congruent vertical cuts that allow for shift of distal fragment laterally (TECH FIG 17A).

 

If vertical cuts are not parallel, the distal fragment will not shift laterally due to impingement between the two fragments.

 

This is a translational osteotomy, directed exactly laterally.

 

Typically, the distal pin is directed at the fourth metatarsal head (TECH FIG 17B).

Osteotomy

 

Horizontal osteotomy limb should be directed exactly laterally or slightly plantarly (TECH FIG 18A).

 

Avoid dropping the hand holding the saw that would potentially create elevation of the distal fragment, leading to transfer metatarsalgia.

 

 

 

TECH FIG 18 • Scarf osteotomy. A. Horizontal osteotomy (guide pins removed). B. Distal dorsal vertical osteotomy limb. C. Proximal plantar vertical osteotomy limb. D. Completed osteotomy.

 

 

 

Distally, the horizontal limb is relatively dorsal, and proximally, it is more plantar. Proximally, it needs to be more plantar to limit risk for stress fracture through dorsal cortex.

 

Vertical limbs performed parallel to one another, using the provisional Kirschner wires (K-wires) as a guide.

 

Distal dorsal vertical limb immediately proximal to the articular surface (TECH FIG 18B)

 

Proximal plantar vertical limb approximately where the plantar metatarsal begins to flare (TECH FIG 18C)

 

Scarf osteotomy is a Z-shaped osteotomy (TECH FIG 18D).

 

Osteotomy modification for increased DMAA

 

Medial wedge resections from the vertical osteotomy limbs (TECH FIG 19) allows rotation of the distal fragment relative to the proximal fragment and helps to correct the increased DMAA.

 

 

24

 

 

 

TECH FIG 19 • Correcting the increased DMAA. A. Second distal dorsal vertical osteotomy limb, converging laterally, creating a medial wedge for resection. B. Medial wedge. C. Medial wedge of bone removed. D.

Similar proximal plantar medial wedge resection.

 

Distal Fragment Lateral Translation

 

To translate the distal fragment relative to the proximal fragment, the lateral periosteum on the lateral aspect of the distal vertical osteotomy limb must be released (TECH FIG 20).

 

This release needs to be performed judiciously to avoid violation of the remaining blood supply to the metatarsal head, entering via the lateral capsule.

 

Maximum translation of the distal fragment is recommended to optimize correction.

Provisional Fixation

 

Given the inherent stability of the osteotomy, a single distal K-wire, placed medially across the osteotomy, typically suffices.

 

 

Fluoroscopic confirmation of the correction Optimal translation (TECH FIG 21A)

 

If DMAA present preoperatively, determine whether wedge resection is appropriate to allow adequate

rotational correction (TECH FIG 21B).

 

 

 

TECH FIG 20 • Lateral periosteal release. Judiciously, without violating the remaining lateral capsule that contains the remaining blood supply to the metatarsal head, the lateral periosteum connecting the two fragments must be divided. If this periosteum remains intact, the lateral distal fragment translation will be limited.

Fixation and Completion

 

Typically, two compression screws are placed from the dorsal fragment to the plantar fragment suffices, one distal and one proximal (TECH FIG 22A)

 

The medial eminence is resected (TECH FIG 22B).

 

Final fluoroscopic evaluation should demonstrate satisfactory alignment even prior to the medial capsular closure (TECH FIG 22C).

 

Medial capsular closure (TECH FIG 22D).

Postoperative Care

 

 

Bunion strapping and protected weight bearing for approximately 6 weeks Follow-up to confirm satisfactory alignment and healing (see FIG 8).

 

 

 

TECH FIG 21 • Fluoroscopic evaluation of translation/correction. A. Lateral distal fragment shift without rotation to correct the increased DMAA. B. Rotation added with DMAA corrected; provisional fixation added.

 

 

25

 

TECH FIG 22 • A. With provisional fixation in place, two compression screws are placed from the proximal fragment into the distal fragment. B. The medial eminence is resected with an oscillating saw. C. Intraoperative fluoroscopy suggests satisfactory correction, prior to the medial capsular closure. Correction should primarily be through bony correction and not dependent on the medial soft tissue closure. D. Medial capsular closure.

 

 

 

PEARLS AND PITFALLS
	Lapidus ▪ Depending on the pathology, there are simpler treatment options for primary procedure bunion surgery. A modified Lapidus procedure is not indicated in the absence of metatarsus primus varus or first ray hypermobility. The modified Lapidus procedure does not correct an increased DMAA. If there is a significant increase in the DMAA, a distal medial closing wedge osteotomy or an Akin procedure is also required. If there is a dorsiflexion malunion from a previous proximal osteotomy, a corrective osteotomy may be necessary instead of a Lapidus procedure.     First TMT joint ▪ Take care not to inadvertently shorten the first metatarsal. Use a saw very preparation sparingly, if ever. The first TMT joint is about 25-30 mm deep, and take care to expose and prepare the entire joint surface to avoid fusing the joint in dorsiflexion. A small Inge retractor or a smooth lamina spreader is invaluable in exposing the joint.

 

	Lateral soft tissue ▪ The terminal branch of the deep peroneal nerve is vulnerable to injury in the release first web space. Excessive lateral release can lead to a hallux varus deformity.     Medial ▪ Only a minimal medial exostectomy may be needed. exostectomy ▪ Avoid dorsiflexion and pronation of the first metatarsal. Fixation of the ▪ Failure to appropriately expose and denude the plantar aspect of the joint can first TMT joint lead to a dorsiflexion malunion. To ensure appropriate position, it is helpful to hold the metatarsals in one hand while the screws are placed. Careful preparation of the 1-2 intermetatarsal joint is mandatory to minimize the incidence of nonunion.     Shortening of the ▪ It is not uncommon to find the first metatarsal shortened with the initial bunion first metatarsal procedure. If that is the case, and if there are signs of significant second metatarsal overload, a second and sometimes third metatarsal shortening osteotomy should be done.

 

 

POSTOPERATIVE CARE

 

The wounds are dressed.

 

A slipper great toe spica fiberglass cast is placed in the operating room.

 

At 2 weeks, the cast is removed to allow wound check and suture removal.

 

 

A new slipper cast or a postoperative bunion shoe is applied for an additional 4 weeks. Patients are non-weight bearing on the operative foot for 6 weeks.

 

If there is radiographic and clinical evidence of fusion at 6 weeks, the cast is removed and physical therapy is begun.

 

At 8 weeks, patients can often return to swimming and biking.

 

More vigorous physical activity is delayed until 3 months after surgery.

 

 

26

 

 

 

FIG 6 • Patient in TECH FIGS 1, 2, 3, 4, 5, 6. A. Early follow-up clinical view. B. Weight-bearing AP radiograph.

C. Lateral radiograph.

 

 

FIGS 6, 7 and 8 are postoperative images of the patients in the example cases.

 

 

OUTCOMES

In appropriately chosen patients, the Lapidus procedure is a reliable option for recurrent hallux valgus.

A prospective cohort study reported an 80% satisfaction rate after the Lapidus procedure for recurrent hallux valgus in carefully selected patients.

 

 

 

 

FIG 7 • Six-month follow-up of the patient in TECH FIGS 12, 13, 14. A. AP clinical view, weight bearing. B. Lateral view, noting arch preserved. C. Lateral view with push-off, noting preserved first MTP joint motion. D,E. AP and lateral weight-bearing radiographs, respectively, suggest progression toward union at prior nonunion site.

 

 

The same prospective cohort study suggested an increased risk of nonunion in smokers.2

 

COMPLICATIONS

Nonunion of the first TMT fusion is the most common complication (6% to 10%).

Transfer metatarsalgia due to dorsiflexion malunion of the first metatarsal or lesser metatarsal length discrepancy

27

 

 

FIG 8 • One-year follow-up radiographs of the patient in TECH FIGS 15, 16, 17, 18, 19, 20, 21, 22. A. AP view. B. Lateral view.

Failure to reduce the sesamoids due to rotational malunion of the first metatarsal or inadequate lateral release

Hallux varus due to excessive lateral release Painful instrumentation

Nerve injury Infection

 

 

 

 

REFERENCES

1. Beischer AD, Ammon P, Corniou A, et al. Three-dimensional computer analysis of the modified Ludloff osteotomy. Foot Ankle Int 2005;26:627-632.

    

    

2. Coetzee JC, Resig SG, Kuskowski M, et al. The Lapidus procedure as salvage after failed surgical treatment of hallux valgus: a prospective cohort study. J Bone Joint Surg Am 2003;85-A(1):60-65.

    

    

3. King DM, Toolan BC. Associated deformities and hypermobility in hallux valgus: an investigation with weightbearing radiographs. Foot Ankle Int 2004;25:251-255.

    

    

4. Klaue K, Hansen ST, Masquelet AC. Clinical, quantitative assessment of first tarsometatarsal mobility in the sagittal plane and its relation to hallux valgus deformity. Foot Ankle Int 1994;15:9-13.

    

    

5. Mann RA. Disorders of the first metatarsophalangeal joint. J Am Acad Orthop Surg 1995;3:34-43.

    

    

6. Nyska M, Trnka HJ, Parks BG, et al. The Ludloff metatarsal osteotomy: guidelines for optimal correction

based on a geometric analysis conduction on a sawbone model. Foot Ankle Int 2003;24:34-39.