Department Of Orthopaedics J.J.M. Medical College – Davangere

Seminar on….

HALLUX VALGUS

MODERATED BY : PRESENTED BYDr. Maheshwarappa .D Dr. Venkatesh GhantasalaProfessor & unit chief Post Graduate Dr. shivashankarappa.AAssistant Professor

on 02-12-2015

RELEVANT ANATOMY

BONES OF THE FOOT :

SESAMOID COMPLEX AND PLANTAR PLATE

LIGAMENTOUS ATTATCHMENTS AROUND HALLUX

MUSCLE ATTACHMENTS

FOOT BIOMECHANICS :

The MTP articulation alone bears one-third of the weight of the forefoot and helps stabilize the longitudinal arch through the attachment of the plantar aponeurosis into its base.

Immediately after the foot hits the ground during ambulation, weight is rapidly transferred from the heel to the metatarsal head region

As a step is taken, the toes are pushed into dorsiflexion

The plantar aponeurosis, which arises from the medial tubercle of the calcaneus and inserts into the base of the proximal phalanx, is pulled over the metatarsal head.

This passively depresses the metatarsal heads and raises the arch. This construct is commonly called the “windlass mechanism”.

Any disorder of the first metatarsophalangeal joint has the potential to disrupt this critical mechanical function. Weight is then transferred to the lesser metatarsals, and secondary pathology in the remainder of the fore foot can develop.

Windlass Mechanism

THE HALLUX VALGUS Carl Hueterto defined the deformity

Most commonly encountered deformities of the forefoot characterized by lateral deviation of the great toe and, medial deviation of the first metatarsal with static subluxation of the first metatarsophalangeal (MTP) joint

Commonly known as a BUNION DEFORMITY after the noticeable prominence on the medial side of the foot - “BUNIO” meaning Turnip

vague term - as it has been used to denote any enlargement / deformity of the MTP joint like bony medial eminence in case of Hallux Valgus, enlarged bursa overlying the metatarsophalangeal joint, ganglion, gouty arthropathy etc .

The toe not only deviates, but it also rotates into pronation. Nail turns to face toward the instep.

As these deformities develop, the lateral capsule and the Adductor Hallucis Tendon on the lateral side of the first MTP joint become contracted. The medial capsule becomes attenuated

In the majority of cases, the first metatarsal itself deviates to the medial side, a deformity known as Metatarsus Primus Varus.

While this happens the intermetatarsal ligament between the second metatarsal head and lateral sesamoid remains unchanged in length.

The sesamoids therefore retain their original position with regard to the rest of the foot and the first metatarsal head subluxates off of them

ETIOLOGY / RISK FACTORS :

Extrinsic Factors Shoes with high heel. Shoes with narrow toe box. Occupational factors Intrinsic Factors Heredity - 60% to 90% Pes Planus Hypermobility of Metatarsocuneiform joint Medial slanted Metatarsocuneiform joint Hyperpronated 1st ray Ligamentous laxity Pronation of hind foot Achilles Contracture Metatarsus primus varus Neuromuscular disorders like CP, Stroke Systemic conditions like Rheumatoid Arthritis Female preponderance Age : 4th-6th decade Miscellaneous factors : 2nd toe amputation; Cystic degneration of medial capsule

PATHO ANATOMY Angle between the 1st and 2nd metatarsals is more than the 8 to 9 degrees usually considered to be the upper limits of normal.

Valgus angle of the 1st MTP joint also is more than the 15 to 20 degrees considered to be the upper limits of normal

If the valgus angle of the first metatarsophalangeal joint exceeds 30 to 35 degrees, pronation of the great toe usually results.

With this abnormal rotation, the abductor hallucis, which is normally plantar to the flexion-extension axis of the first metatarsophalangeal joint, moves further plantarward

In this case, the only restraining medial structure is the medial capsular ligament with its capsulosesamoid portion and capsulophalangeal portions

The unopposed adductor hallucis pulls the great toe further into valgus, stretching the medial capsular ligament particularly capsulosesamoid portion

Attenuated medial capsular ligament , allow the metatarsal head to drift medially from the sesamoids

.

Finally, the sesamoid ridge on the plantar surface of the first metatarsal head (the crista) flattens because of pressure (abutment) from the tibial sesamoid

With this restraint lost, the fibular sesamoid displaces partially or completely into the first intermetatarsal space

In this situation, the patient is bearing less weight on the first ray and more on the lesser metatarsal heads, increasing the likelihood of transfer metatarsalgia, callosities, and stress fracture of a lesser metatarsal

Sometimes severe crossover toe deformity of second toe associated with severe hallux valgus known as HAMMER TOE DEFORMITY. Here pain beneath second metatarsal head is Primary complaint .

SIGNS AND SYMPTOMS

Asymptomatic Pain- the primary symptom of hallux valgus is PAIN over the medial eminence. Pressure from footwear is the most frequent cause of this discomfort. Valgus deformity Tenderness aesthetic or cosmetic concerns Full blown or full spectrum of hallux valgus presents as - - Varus deformity of the first metatarsal, - Valgus of the great toe, - Bunion formation, - Arthritis of the first metatarsophalangeal joint, - Hammer toe of one or more toes, - Corns, - Calluses and - Metatarsalgia

PHYSICAL EXAMINATION Skin - callosities and corns

Sites of pain

Magnitude of the hallux valgus deformity Pronation of the great toe Motion of 1st MTP joint Metatarsocuneiform joint for hypermobility

Pes planus deformity , Contracture of the Achilles tendon

Neurovascular status of the limb

Mobility and structure of foot in general

Gait analysis

Deformities of lesser toes

RADIOGRAPHIC ASSESSMENT :

Standard series of radiographs which are critical in the evaluation of the deformity and guiding the treatment should include – Weight-bearing radiographs of the Foot in AP, LATERAL and OBLIQUE views. Non-weight bearing AXIAL or SESAMOID view

The Information that should be gleaned from the films includes :

•Assess for bone and joint deformity

•Length and shape of 1st MT

•The relative lengths of the first and second metatarsals

•The presence or absence of deformity in the hallux itself.

•The presence or absence of arthritis at the first MTP or in the midfoot

•The presence or absence of instability at the first metatarsocuneiform joint

•Forefoot alignment is evaluated for metatarsus Adductus

•The hallux valgus angle

•Joint congruency (Congruent vs. Incongruent joint

•The distal metatarsal articular angle formed by the alignment of the first metatarsal and the margins of the joint surface of the first MTP

•The intermetatarsal angle formed by the axes of the first and second metatarsals on the AP view

Hallux Valgus Angle

Normal <15 Mild <20 Moderate 20-40 Severe >40

1st/2nd Inter Metatarsal Angle (IMA) :

Normal <9

Mild <11

Moderate 11-16

Severe >16

Distal Metatarsal Articular Angle (DMAA) :

defines the relationship of the articular surface of the distal first metatarsal with the longitudinal axis of the first metatarsal

Quantities the magnitude of lateral slope of articular surface. It is usually less than < 6 degrees

Hallux Interphalyngeal Angle

The angle made by the longitudinal axes of the proximal and distal phalynges of the great toe

Subluxed Vs Congruent Joint : A. Hallux valgus deformity with subluxation (non congruent joint) is characterized by lateral deviation of the articular surface of the proximal phalanx in relation to the articular surface of the distal first metatarsal. B. Hallux valgus deformity with a nonsubluxated (congruent) metatarsophalangeal joint is caused most often by lateral inclination of the distal metatarsal articular surface

A. Subluxed joint B. Congruent joint

CLASSIFICATION NORMAL MILD MODERATE SEVERE

HALLUX VALGUS ANGLE < 15* < 20° 20° to 40° > 40°

1-2 INTERMETATARSAL ANGLE

< 9* 11° or less. 12 - 15° 16° or more

SUBLUXATION OF THE LATERAL SESAMOID, AS MEASURED ON AN AP RADIOGRAPH

Nil or minimal

< 50% 50% to 75% > 75%

Classification

TREATMENT

1. Conservative Management 2. Surgical Management

Conservative Management : 1. FOOT WEAR MODIFICATION First line of treatment Widening of toe box Decreasing the heel height Enhanced arch support may negate effects of pes planus. 2. TA STRETCHING EXERCISES AND TA LENGTHENING. 3. THERMOPLASTIC NIGHT SPLINTS 4. BUNION AIDS AND STRAPPING – Bunion pads (like a Polo/doughnut shape) can help to offload the tender bunion, But strapping and overnight splints are probably a waste of money with no quality research to support their use. 5. CHIROPODY - can help by taking care of the callosities and skin compromise. 6. PODIATRY – may help to correct the foot biomechanics

Surgical Management Indications : Persistent symptoms for atleast 2 years.

Progression of deformity. Failure of non-operative treatment like foot wear modification. Should not be performed for cosmetic reasons alone.

Goals : To correct all pathologic elements and yet maintain a biomechanically functional fore foot . To obtain a pliable plantigrade and cosmetically acceptable foot

Any procedure chosen must take into account the following structural components……………………….

Valgus deviation of the great toe (hallux valgus).

Varus deviation of the first metatarsal. Pronation of the hallux, first metatarsal, or both.

Hallux valgus interphalangeus.

Arthritis and limitation of motion of the first metatarsophalangeal joint. Length of the first metatarsal relative to lesser metatarsals. Excessive mobility or obliquity of the first metatarsomedial cuneiform joint.

The medial eminence (bunion) .

The location of the sesamoid apparatus.

Intrinsic and extrinsic muscle-tendon balance and synchrony.

More than 130 operations have been recommended for the treatment of Hallux Valgus.

Various surgical procedures in general……………….1. Soft Tissue Procedures

Indicated in very mild disease in young female (almost never alone)

2. Distal MT OsteotomiesIndicated in mild disease

3. Proximal MT Osteotomies

4. Combined MT OsteotomiesIndicated in more moderate disease

5. Phalangeal Osteotomies

6. Fusion Procedures / Joint ArthrodesisIndicated in severe disease with progressing degenerative changes.

7. MTP Resection Arthroplasty Only indicated in elderly patients with low functional demand

SOFT TISSUE PROCEDURES :

MODIFIED MCBRIDE PROCEDURE : Release of adductor hallucis, transverse metatarsal ligament, and lateral capsule combined with excision of medial eminence and placation of the capsule medially.

This procedure was modified to retain the lateral sesamoid, which helps to prevent hallux varus (which as common with original mcbride bunionectomy); As this procedure attempts to re-align the mtp joint, it is best performed on an incongruent joint

INDICATIONS : •30 to 50 year old woman with clinical symptoms and a history of conservative management failure.•HVA --- 15 to 25 degrees•IMA --- less than 13 degrees.•HVI --- less than 15 degrees•No degenerative changes at the metatarsophalangeal joint

Modified Mcbride Bunionectomy : Three staged procedure –

MEDIAL CAPSULAR INCISION , JOINT REDUCTION AND MEDIAL EMINENCE REMOVAL.

RELEASE OF VALGUS DEFORMING FORCES i.e. Adductor hallucis, flexor hallucis brevis , deep transverse intermetatarsal ligament and lateral capsule.

FIBULAR SESMOIDECTOMY (if needed) AND MEDIAL CAPSULAR IMBRICARTION .

MEDIAL CAPSULAR INCISION , JOINT REDUCTION AND MEDIAL EMINENCE REMOVAL.

RELEASE OF VALGUS DEFORMING FORCES

FIBULAR SESMOIDECTOMY (if needed) AND MEDIAL CAPSULAR IMBRICARTION

METATARSAL OSTEOTOMIES :

1. Mitchell {step cut osteotomy}

2. Wilson

3. Chevron

4. Modified chevron

1. Proximal Crescentic 2. Proximal Chevron 3. Opening Wedge 4. Ludloff 5. Mau 6. Closing Wedge 7. Scarf

DISTAL MT OSTEOTOMIES PROXIMAL MT OSTEOTOMIES

DISTAL METATARSAL OSTEOTOMIES

Done for HVA ≤ 40, IMA < 13 Mitchell’s osteotomy :

1.SKIN AND CAPSULAR INCISION dorso-medial incision distally based flap is then created from the medial joint capsule in order to expose the medial eminence.

2. MEDIAL EMINENCE REMOVAL 3. EXPOSURE OF THE METATARSAL NECK AND DISTAL SHAFT AND PLACEMENT OF GUIDE HOLES Drill two holes perpendicularly through the metatarsal shaft from the dorsal to the plantar direction. Pass an absorbable suture through the holes so that it can be tied dorsally.

4. DOUBLE OSTEOTOMY OF THE METATARSAL NECK Make the first cut distally perpendicular to the medial border of the metatarsal neck which is incomplete and should leave 3 to 6 mm of lateral shaft intact.

second osteotomy in a similarly perpendicular direction to the metatarsal shaft, starting medially 3 to 4 mm proximal to the first cut which is complete 5.LATERAL DISPLACEMENT OF THE CAPITAL FRAGMENT manually shift the entire capital fragment laterally until the lateral spike rests on the lateral cortex of the proximal fragment. Tie the suture while the capital fragment is plantar flexed about 10 degrees plantar flexion

6. CAPSULAR CLOSURE (MEDIAL CAPSULORRHAPHY)

Chevron Osteotomy

Accepted widely for the correction of mild and moderate hallux valgus deformities

Reduces risk of dorsal displacement

straight midline medial incision capsular incision longitudinal in the midline (medial) of the medial eminence

The medial eminence is excised

V shaped osteotomy is planned in transverse plane in the metatarsal head near the subchondral bone such that each of the dorsal limb and plantar limb of V should make 30 degrees of angle with longitudinal axis of MT shaft.

Shift the capital fragment laterally by thumb pressure.

Medial capsulorrhaphy is done after bringing the hallux into 5 degrees of valgus.

Medial projection of the metatarsal on the proximal side of the osteotomy is Shaped into the contour of the metatarsal neck and distal shaft.

Chevron osteotomy. A, Skin and capsular incision (do not denude metatarsal head of soft tissue). B, Medial eminence removal. C, Osteotomy should be in cancellous bone—not in cortical bone of metatarsal neck. D, Proper angle of osteotomy in horizontal plane. E, Correct coronal plane of osteotomy. F, Correct technique of pushing metatarsal head fragment laterally. G, Avoid excessive lateral displacement of capital fragment. H, Removal of overlapping proximal fragment.

Modified Chevron Osteotomy: The modified chevron osteotomy is simply a more proximal placement of the apex of the osteotomy in the metatarsal head.

Potential problems of this modification of the chevron osteotomy are instability of the osteotomy and insufficient metaphyseal bony contact. Proper placement of the osteotomy cuts is mandatory. The metatarsal osteotomy must be internally fixed. . Used for more severe deformities up to 35 degrees of hallux valgus and up to 15 degrees of first to second intermetatarsal diversion.

Proximal Metatarsal Osteotomies :

If varus of the first metatarsal, whether primary or secondary, contributes to the hallux valgus complex, correction near the origin of the deformity is reasonable

In addition, a few degrees' shift of the metatarsal at its base causes marked improvement at the distal end of the metatarsal

A patient without significant degenerative arthritis in the first metatarsophalangeal joint and with hallux valgus of more than 35 degrees and an intermetatarsal angle of more than 10 degrees may benefit from a proximal metatarsal osteotomy and a distal soft-tissue procedure at the metatarsophalangeal joint.

An osteotomy at the base of the metatarsal has the following advantages

Cancellous bone and broad contact surfaces of the fragments promote early stability (3 to 5 weeks) and union (6 to 8 weeks)

Small changes in position at the osteotomy produce excellent correction at the distal end of the metatarsal where the symptoms are located

Narrowing of the forefoot improves the variety of footwear possible and gives an excellent cosmetic result

Large angles between the first and second metatarsals can be corrected.

Slightly tilting the distal fragment plantarward reduces load bearing by the second metatarsal, decreasing the chance of transfer metatarsalgia.

The metatarsal is shortened minimally, if at all, unless the surgeon chooses a technique that intentionally shortens it (the width of the osteotomy cut itself is more than compensated for by the “straightening of the bone”).

Currently, the most frequently used proximal metatarsal osteotomies are -

Proximal Crescentic Osteotomy

1st stage - The first incision is made dorsally in the intermetatarsal space to release the adductor hallucis, the deep transverse intermetatarsal ligament, and the lateral capsule of the first metatarsophalangeal joint. 2nd stage - The second incision is made midline-medial over the medial eminence to remove the medial eminence and perform a capsulorrhaphy

3rd stage - Dorsal longitudinal incision

Score the dorsal aspect of the metatarsal transversely at 1 and 2 cm levels distal to the metatarsocuneiform articulation.

first scored mark represents the osteotomy site, and the second represents the area for placement of the screw Drill a 3.5 mm hole 1 cm distal to the osteotomy site in the center of the metatarsal shaft, and direct it proximally 45 degrees to the metatarsal shaft, penetrating only the dorsal cortex

Using an oscillating saw with a crescent shaped saw blade placed convex distally, begin the osteotomy on the most proximal scored mark

Displace the proximal fragment medially, rotate the distal fragment around the osteotomy site and fix the osteotomy site with a screw.

Complications : Limitation of motion of the first metatarsophalangeal joint

Dorsiflexion malunion of the osteotomy site with transfer metatarsalgia

Hallux varus.

Proximal Chevron Osteotomy:

The primary benefit of this configuration of the osteotomy is the increased stability at the osteotomy site, although it must be internally fixed with a pin or screw

medial eminence removal

release fibular sesamoid-metatarsal ligament and the conjoined tendon of the adductor hallucis muscle from the lateral aspect of the sesamoid.

Do not divide the transverse metatarsal ligament

percutaneously pass a large Dacron braided polyester suture around the second metatarsal neck. The needle emerges beneath the first metatarsal into the wound.

Grasp the free end of the suture with the hemostat, and pull it beneath the skin and tendons to emerge over the first metatarsal through the wound medially

Using a suture passer, pass the deep leg of the suture through a 2-mm transverse hole drilled in the dorsal half of the first metatarsal head-neck junction.

Make a transverse chevron osteotomy with an angle of 45 degrees and with the apex directed distally at the diaphyseal-metaphyseal junction of the first metatarsal. The proximal arm of the osteotomy should end 1.5 cm from the metatarsocuneiform jt

After rotating the distal fragment of the osteotomy laterally to correct the metatarsus primus varus, hold the osteotomy in the corrected position with a guide pin,

Insert a 4-mm screw from the plantar aspect of the distal fragment, and direct it laterally and dorsally across the osteotomy into the proximal fragment. The screw should not cross the tarsometatarsal joint Before final tightening of the screw, tie the large Dacron “lashing” suture At this point, the alignment of the sesamoids is partially corrected

The capsular closure holds the sesamoids beneath the first metatarsal head and corrects the hallux valgus

Scarf Osteotomy

Horizontally directed displacement Z-osteotomy made at the diaphyseal level.

This configuration has a high level of intrinsic stability, particularly in the sagittal plane, and provides a broad surface area of bony healing

Stability of the osteotomy allows early weight bearing and return to activities.

Scarf osteotomy has become popular because of its versatility it allows Elongation or shortening of the first metatarsal Medial displacement of the capital fragment to correct hallux varus Plantar displacement to increase the load of the first ray Lateral displacement of the plantar bone fragment to reduce the intermetatarsal angle

Current indications for the scarf osteotomy are mild-to-moderate deformities (intermetatarsal angle of 11 to 18 degrees and hallux valgus angle 20 to 40 degrees)

Ludloff Osteotomy :

Ludloff described an oblique osteotomy of the first metatarsal oriented from dorsoproximal to distal plantar. He originally shortened the metatarsal without using internal fixation; this technique was abandoned for many years because of its inherent instability. With the development of newer fixation methods that added stability, the technique has gained popularity. Biomechanical studies have shown that the Ludloff osteotomy fixed with lag screw compression is more rigid than proximal crescentic and other proximal first metatarsal osteotomies.

Advantages Slight supination of the cut (8 degrees) that allows plantar flexion of the first metatarsal, theoretically minimizing the risk of transfer metatarsalgia further

Simplicity (involving only a single cut in the bone).

Angular correction through bony rotation that allows the surgeon to “dial in” the precise amount of correction desired Mechanical stability that allows early ambulation

Mau Osteotomy Proximal oblique orientation is opposite to that of the Ludloff osteotomy, with proximal plantar and distal dorsal exit points

Fixation is with two cannulated screws placed from dorsal to plantar, perpendicular to the osteotomy

Sagittal saw is placed parallel to the weight-bearing surface of the foot and the osteotomy is completed from proximal-plantar to distal-dorsal

Because of the plane of the osteotomy, it has greater initial stability with weight-bearing when compared to the Ludloff

Medial Cuneiform Osteotomy :

Center a medial longitudinal incision over the first cuneiform

Fix the osteotomy with crossed K-wires or a cancellous screw, and close the wound in the routine manner

The medial eminence of the metatarsal head can be used as an interposition graft

Distract the osteotomy site with a lamina spreader, and impact the bone graft

Direct the osteotomy in a mediolateral plane, and carry it to a depth of 1.5 cm, ensuring that the dorsal and the plantar cortices are transected.

PROXIMAL PHALANGEAL OSTEOTOMY OR AKIN OSTEOTOMY :

Used primarily for Hallux Valgus Interphalangeus deformity

After medial eminence removal and adductor tenotomy from the base of proximal phalynx a medial closing –wedge phalangeal osteotomy is done and ostetomy closed and stabilized with the help of 2 K wires passed from distal to proximal through the phalanges and ostetomy site

Mostly used in combination with 1st MT osteotomies for greater correction in congruent joint.

Contraindications for the procedure are the following:

• Rheumatoid arthritis• Moderate-to-severe osteoarthritis at the metatarsophalangeal joint• Intermetatarsal angle more than 13 degrees• Hallux valgus angle more than 30 degrees• Subluxation laterally of the tibial sesamoid more than 50% of its width.• Open physis of the proximal phalanx

ARTHRODESIS OF THE FIRST METATARSOPHALANGEAL JOINT

Indications : Severe deformity (an intermetatarsal angle > 20 to 22 degrees, a hallux valgus angl e > 45 degrees, and severe pronation of the hallux)

Degenerative arthritis with hallux valgus.

Possibly for mild-to-moderate deformity when motion of the MTP joint is limited and painful

Recurrent hallux valgus

Hallux valgus in patients with rheumatoid arthritis

Posttraumatic hallux valgus with severe disruption of all medial capsular structures that cannot be adequately reconstructed.

Hallux valgus caused by muscle imbalance in patients with neuromuscular disorders, such as cerebral palsy, to prevent recurrence

Follolowing techniques of arthrodesis are described : Arthrodesis with Small plate fixation / Low-profile contoured dorsal plate and compression screw fixation

Truncated Cone Arthrodesis

Wire Loop Arthrodesis

Ball-and-Socket Arthrodesis (Molded Arthrodesis)

Arthrodesis of 1st Metatarsocunieform Joint ( Lapidus Procedure )

Arthrodesis with Small plate fixation / Low-profile contoured dorsal plate and Compression Screw Fixation

Truncated Cone Arthrodesis

Ball And Socket Arthrodesis (Molded Arthrodesis) :

Make a midline medial incision

Remove all cartilage and subchondral bone

Prepare the base of the proximal phalanx by deepening the natural concave surface

Align the joint surfaces in the proper position of dorsiflexion, valgus, and neutral rotation.

Impact the surfaces, and hold them with two K-wires

Evaluate the final position of the metatarsophalangeal joint (15 degrees of valgus, 25 degrees of extension to the longitudinal axis of the first metatarsal and neutral rotation

Drill a hole through the metatarsal head into the proximal phalanx. Overream the metatarsal side of the arthrodesis with Insert a full-threaded, 4-mm cancellous screw from the metatarsal head into the proximal phalanx

Arthrodesis of the First Metatarsocuneiform Articulation (Lapidus Procedure)

Mann described an excellent algorithm for selecting the appropriate operative procedure in the treatment of hallux valgus and hallux rigidus.