DEFINITION

Hallux rigidus refers to limited dorsiflexion of the first metatarsophalangeal (MTP) joint as a result of dorsal osteophyte impingement.

Plantarflexion is typically not limited but may be restricted if a large dorsal osteophyte is present. In advanced stages, global arthrosis of the first MTP joint is present.

ANATOMY

The first MTP joint is supported medially and laterally by collateral ligaments that provide medial-lateral stability (FIG 1A).

FIG 1 • A. Medial aspect of first MTP joint anatomy. Collateral ligaments afford medial-lateral stability. B.

Dorsal aspect of first MTP joint anatomy. C. Detail of first MTP joint anatomy with detail of sesamoid complex.

The plantar aspect of the joint consists of the following:

The sesamoid complex, including attachments of two slips of the flexor hallucis brevis, which invest the

sesamoids (FIG 1B)

The plantar plate, a thick fibrous band of tissue that additionally invests and supports the sesamoids. The flexor hallucis longus runs between the sesamoids (FIG 1C).

The dorsal aspect of the joint includes the capsule, the attachment of the extensor hallucis brevis to the base of the proximal phalanx, and the extensor hallucis longus within the extensor hood.

PATHOGENESIS

Congenital hallux rigidus (tends to be bilateral) Concomitant hallux interphalangus

44

FIG 2 • Assessing first MTP joint motion in patient with hallux rigidus. A. Dorsiflexion produces symptomatic impingement. B. Often, plantarflexion is also painful, with traction of the dorsal soft tissue structures over the dorsal osteophyte. C. Neutral position demonstrating dorsal osteophyte.

A flat or chevron-shaped MTP joint. This tends to concentrate stresses more centrally. Abnormal joint biomechanics

Trauma to the dorsal articular cartilage, either by a direct blow or repetitive microtrauma Cartilage damage secondary to inflammatory reactions from gout or inflammatory arthritis

NATURAL HISTORY

Abnormal stresses across the MTP joint—through alterations of biomechanics, increased concentration of dorsal cartilage stresses and wear, inflammatory reaction, or direct cartilage injury—result in reactive dorsal osteophyte and marginal osteophytes. If those stresses are not alleviated or corrected, more global arthritic

changes may evolve.

FIG 3 • Radiographs of patient with hallux rigidus. A. AP view demonstrating joint space narrowing. B. Lateral view with dorsal osteophyte on first metatarsal head. C. Magnetic resonance imaging (MRI) is not required in the evaluation of hallux rigidus but provides detail if the degree of degenerative change is mild and an osteochondral defect is suspected.

PATIENT HISTORY AND PHYSICAL FINDINGS

Sagittal range of motion is assessed (FIG 2). Pain is typically elicited with extremes of motion, secondary to dorsal impingement, and with plantar motion traction on the dorsal osteophyte.

A positive grind test indicates more global arthritis, a relative contraindication for cheilectomy. Note presence or absence of tenderness with the sesamoid complex examination.

IMAGING AND OTHER DIAGNOSTIC STUDIES

Standing anteroposterior (AP), lateral, and oblique radiographs are required (FIG 3A,B).

The joint space may be obliterated by osteophytes on the AP radiograph, so the oblique radiograph may provide a better view of the retained joint surface.

45

The AP radiograph is useful to evaluate medial and lateral osteophytes, and the lateral radiograph will reveal the presence of metatarsus elevatus, and the extent of the dorsal osteophyte.

Axial sesamoid view will provide additional information about the sesamoid complex.

Magnetic resonance imaging is helpful if osteochondral defect of the metatarsal head is suspected (FIG 3C).

DIFFERENTIAL DIAGNOSIS

Arthrosis (advanced hallux rigidus)

Osteochondral defect

“Turf toe,” sesamoid complex injury Gout

NONOPERATIVE MANAGEMENT

Nonoperative treatment consists of the institution of nonsteroidal anti-inflammatory drugs (NSAIDs), accommodative orthotics, and, rarely, physical therapy if gait abnormality is present.

Accommodative orthotics are designed to restrict sagittal range of motion of the hallux and to redistribute weightbearing stresses across the first MTP joint with the use of a Morton extension.

If sesamoid inflammation is present, protective padding is added around the sesamoids and the orthotic is welled out under the sesamoids to provide stress relief.

SURGICAL MANAGEMENT

Preoperative Planning

Preoperatively, patients are assessed for whether they are appropriate candidates for cheilectomy or for fusion if there are symptoms of more global arthritis of the first MTP joint.

Cheilectomy is performed for predominantly dorsal arthritic symptoms and for failure to respond to nonoperative means of treatment, as outlined in the previous section.

Positioning

Preoperatively, patients receive a regional ankle block consisting of a 1:1 mixture of 0.5% bupivacaine and 1% lidocaine, without epinephrine.

Intravenous antibiotics are administered in the holding area, 30 to 45 minutes before the procedure.

The patient is placed supine on the operating room table, with the foot at the distal edge of the table to allow for easier fluoroscopic access.

The foot, ankle, and lower leg are prepped and draped to the lower calf with the use of a leg holder.

Approach

The first MTP joint is approached dorsally, starting distally from the midportion of the proximal phalanx, and

extending proximally 3 cm proximal to the joint.

TECHNIQUES

• Incision and Exposure

The incision is made medial to the extensor hallucis longus tendon, taking care to preserve the tendon within its sheath (TECH FIG 1A).

Once the tendon is brought laterally and protected, the incision is carried down through the dorsal capsule and distally past the base of the proximal phalanx.

Loose bodies and proliferative synovium are excised.

TECH FIG 1 • Approach. A. Dorsomedial incision. B. Identify and protect the dorsomedial sensory nerve to the hallux and the extensor hallucis longus (EHL) tendon. C. Longitudinal capsulotomy after nerve and tendon are retracted.

The dorsal aspect of the collateral ligaments is reflected to allow for exposure of the medial and lateral aspects of the joint. Care must be taken to avoid inadvertently destabilizing the joint.

Hohmann or Senn retractors are placed medially and laterally to protect the soft tissues. Particular attention is paid to protect the extensor hallucis longus tendon distally (TECH FIG 1B,C).

• Cheilectomy

  46

   

  The dorsal osteophyte is resected from the base of the proximal phalanx with a flexible chisel (TECH FIG 2A,B). The hallux is maximally dorsiflexed during this maneuver to protect the central and plantar cartilage of the first metatarsal head.

   

  The hallux is maximally plantarflexed to allow for examination of the cartilage of the metatarsal head.

   

   

   

  TECH FIG 2 • A-F. Resection. A. Removing dorsal osteophyte on proximal phalanx. B. Joint exposed, demonstrating typical degenerative wear pattern. Note medial and lateral osteophytes. C. Dorsal view of dorsal osteophyte. D. Sagittal view of large dorsal osteophyte and chisel positioned for resection. E. Chisel to resect osteophyte and dorsal 1/4 to 1/3 of residual articular surface. F. After osteophyte resection. (continued)

   

   

  The dorsal 25% to 30% of the metatarsal head articular surface is resected with a flexible chisel (TECH FIG 2C-F), beginning distally and angled proximally to exit at the metaphyseal-diaphyseal junction of the metatarsal.

   

   

  The extent of articular surface resection frequently corresponds to the wear pattern of the cartilage. Avoid exiting too far proximal in the diaphyseal bone, which might weaken the metatarsal.

   

  47

   

   

   

  TECH FIG 2 • (continued) G-I. Checking first the MTP joint range of motion after resection. G. Passive dorsiflexion of the toe relative to the metatarsal shaft axis should approach 90 degrees. H. Fluoroscopy prior to osteophyte resection. I. Fluoroscopy after osteophyte resection.

   

   

  Alternatively, a microsagittal saw can be used to resect bone from a proximal to distal direction, but care must be taken to avoid excessive articular cartilage resection. I prefer to start the cartilage resection from the metatarsal head distally.

   

  Medial and lateral osteophytes are resected, taking care to avoid destabilization of the collateral ligaments.

   

  The hallux is maximally dorsiflexed and inspected for any residual impingement (TECH FIG 2G). If necessary, additional bone is resected and motion is reevaluated.

   

  Fluoroscopy can be used to verify adequacy of bone resection, in both the AP and sagittal planes (TECH FIG 2H,I).

   

  If discrete osteochondral defect is noted, the base of the defect is drilled in multiple directions with a 0.045-inch Kirschner wire to facilitate bleeding into the defect and formation of fibrocartilage.

• Wound Closure

The wound is irrigated, and a thin film of bone wax is applied to the cancellous bone of the dorsal metatarsal.

Closure of the capsule is performed with a 2-0 absorbable suture. If necessary, the extensor mechanism is centralized to prevent valgus drift of the hallux postoperatively.

Subcutaneous closure is performed with either 2-0 or 3-0 absorbable suture, and the skin is closed with simple 4-0 nylon suture. A sterile compressive dressing is applied.

PEARLS AND PITFALLS

48

FIG 4 • Postoperative management. A. Closure. B. Immediate weight bearing in a postsurgical shoe.

POSTOPERATIVE CARE

Patients are instructed to elevate the operative leg for the first 10 days, with heel weight bearing in a postoperative shoe (FIG 4).

At 10 days, sutures are removed and Steri-Strips applied. Postoperative radiographs are obtained at this visit.

At this point, weight bearing as tolerated is permitted in a postoperative shoe. The patient weans to a sneaker or comfortable shoe over the successive 10 to 14 days.

Physical therapy is also instituted at 10 days, concentrating on reestablishing range of motion, diminishing

edema, and performing scar massage.

Physical activity such as biking, swimming, and elliptical trainer and StairMaster usage is instituted shortly thereafter. Running activities are typically withheld until approximately 3 months after surgery.

The use of an accommodative orthotic with a Morton extension is occasionally prescribed for a period of time if patients complain of discomfort after activities or continued weight bearing on the lateral aspect of the foot is necessary.

OUTCOMES

Good to excellent outcomes after cheilectomy range from 72% to 92%. Better results are noted with grades I and II.

Poorer outcomes are reported if there is over 50% loss of articular cartilage at time of surgery.

No correlation is noted between postoperative radiographic deterioration of joint space and clinical outcome.

Results do not tend to diminish with time.

Less than 8% of patients subsequently require fusion.

COMPLICATIONS

Inadequate bone resection Destabilization of the collateral ligaments Dorsomedial cutaneous nerve damage Progression of arthritis

SUGGESTED READINGS

1. Coughlin MJ, Shurnas PS. Hallux rigidus: demographics, etiology, and radiographic assessment. Foot Ankle Int 2003;24:731-743.

    

    

2. Coughlin MJ, Shurnas PS. Hallux rigidus. Grading and long-term results of operative treatment. J Bone Joint Surg Am 2003;85-A(11): 2072-2088.

    

    

3. Feltham GT, Hanks SE, Marcus RE. Age-based outcomes of cheilectomy for the treatment of hallux rigidus. Foot Ankle Int 2001;22:192-197.

    

    

4. Hattrup SJ, Johnson KA. Subjective results of hallux rigidus following treatment with cheilectomy. Clin Orthop Relat Res 1998;(226):182-191.

    

    

5. Mann RA, Clanton TO. Hallux rigidus: treatment by cheilectomy. J Bone Joint Surg Am 1988;70(3):400-406.

    

    

6. Mulier T, Steenwerckx A, Thienpont E, et al. Results after cheilectomy in athletes with hallux rigidus. Foot

Ankle Int 1999;20:232-237.