Foot Osteochondroses (Accessory Navicular, Navicular Asceptic Necrosis-Kohler, Islin—Apophysitis of Base 5th MT)

By admin Last updated Dec 6, 2023

Ovid: 5-Minute Sports Medicine Consult, The

Jeffrey B. Kreher

Basics

Description

Accessory navicular: Unfused accessory ossification center at posterior tibialis tendon (PTT) insertion
Geist classification:
- Type I: Small sesamoid bone in PTT (usually 2–3 mm)
- Type II: Synchondrosis between navicular and os naviculare (usually 8–12 mm triangular or heart-shaped); 70% of symptomatic lesions
- Type III: Cornuate navicular (questionable end stage of type II with ossification across synchondrosis)
Synonym(s): Os tibiale (externum); Os naviculare (secundarium); Symptomatic accessory tarsal navicular; Accessory scaphoid bone; Accessory tarsal scaphoid; Navicular secundum

Pediatric Considerations

Köhler disease: Articular osteochondrosis with secondary involvement of articular and epiphyseal cartilage as a consequence of avascular necrosis of tarsal navicular bone; synonyms: Aseptic necrosis of tarsal navicular; Avascular necrosis of navicular; Koehler disease; Idiopathic osteonecrosis of navicular in children
Osteonecrosis of tarsal navicular in adults: Mueller-Weiss disease
Iselin disease: Nonarticular osteochondrosis of the 5th metatarsal at site of ligament and tendon attachment and trauma; synonym: Traction apophysitis of 5th metatarsal
Traction apophysitis at base of the 5th metatarsal bone: Peroneus brevis insertion

Epidemiology

Accessory navicular:

Most often symptoms found in active children and females in 4th decade
2nd most common accessory bone of foot
Accessory bones in 36% of asymptomatic feet

Pediatric Considerations

Köhler disease: Rare:
- Age of onset 2–9 yrs
- Mean age of diagnosis: Males 6 yrs, females 4.5 yrs
Occasionally bilateral Iselin disease: Rarely reported but probably more common than appreciated:
- Age of onset in late childhood or early adolescence
- Apophysis appears: Males 11–12 yrs, females 10 yrs
- Apophysis fuses about 2 yrs later.

Prevalence

Accessory navicular:
- 4–21% of general population: Most asymptomatic
- 50–90% bilateral
- In skeletally immature, 64% symptomatic
Köhler disease: Prevalence unknown
Iselin disease: Prevalence unknown

Risk Factors

Accessory navicular: May be worse with hyperpronation
Köhler disease: May be more common in late ossification of tarsal navicular
Iselin disease:
- May be more common with tight calf muscles
- Seen most commonly in soccer, basketball, gymnastics, and dance

Etiology

Accessory navicular: Becomes symptomatic in the following:
- Adolescent patients from chondroosseous disruption owing to tension and shear forces from PTT and foot dynamics (type II)
- From pressure of overlying footwear (all types)
- Older patients owing to posttraumatic disruption of synchondrosis (type II) ± PTT avulsion or rupture
- Symptomatic type II: Microfracture, acute and chronic inflammation, and cellular proliferation
Köhler disease:
- Tarsal navicular is last bone to ossify and believed to be more susceptible to compression injury.
- May be due to ischemia from recurrent cumulative microtrauma or acute macrotrauma
Iselin disease:
- Repetitive traction from peroneus brevis
- Acute avulsion fracture with widening of chondroosseous junction

Commonly Associated Conditions

Köhler disease: Occasionally with other osteochondroses such as Osgood-Schlatter or Legg-Calve-Perthes disease

Diagnosis

Accessory navicular:
- Symptomatic or asymptomatic
- Most often clinically relevant accessory navicular is symptomatic type II.
Köhler disease:
- Based on history and x-ray findings
- Does not equal asymptomatic feet with abnormal x-ray findings: Multiple ossification centers or other process
Iselin disease: Based on history and x-ray findings

History

Accessory navicular:
- Asymptomatic or medial foot pain with navicular bump
- If painful, onset gradual or acute
- If painful, onset may be secondary to ankle sprain or contusion.
- Worse with activity (during or after) and compression with shoes
- May have limp/antalgic gait
Köhler disease:
- Medial foot pain (tenderness at tarsal navicular)
- Usual gradual in onset
- Worse with activity
- Limp/antalgic gait
Iselin disease:
- Lateral foot pain (tenderness at proximal 5th metatarsal)
- Usual insidious onset
- May be acute after significant trauma; often inversion injury
- Worse with weight-bearing, lateral movements, cutting, and jumping
- Limp/antalgic gait

Physical Exam

Accessory navicular:
- Protuberant tarsal navicular (posteromedial aspect)
- Normal range of motion (ROM) of foot, ankle, hindfoot
- Possible overlying swelling
- Tender to palpation over tarsal navicular ± PTT distally
- Pain with resisted plantarflexion and inversion
Köhler disease:
- Antalgic gait with shifting of weight to lateral aspect of foot
- Possible overlying swelling
- Less likely overlying warmth
- Tender to palpation over tarsal navicular
- May have pain with resisted plantarflexion and inversion
Iselin disease:
- Perhaps prominent proximal 5th metatarsal
- Very little or no erythema, edema, or ecchymosis
- May show mild pronation
- Tender to palpation at peroneus brevis insertion
- Pain with resisted eversion, extreme inversion, and extreme plantar- or dorsiflexion

Diagnostic Tests & Interpretation

Imaging

Accessory navicular:
- Radiographs:
  - Anteroposterior and lateral foot often miss.
  - Must include external oblique view
  - Findings depend on type (see “Geist classification” in “Description”)
- US:
  - More for tendinous abnormalities
  - May see heterogeneous synchondrosis (compared with asymptomatic side)
  - May see diastasis in older patient
- MRI:
  - Rarely needed
  - STIR images show increased signal within accessory navicular at PTT insertion.
- Bone scan:
  - Increased uptake in region
  - Only 50% specific but 100% sensitive

P.167

Köhler disease:
- Radiographs:
  - Anteroposterior and lateral foot
  - Commonly, narrowing/flattening of the tarsal navicular and/or loss of trabecular pattern
  - Possibly, apparent fragmentation or diffusely increased density in normal-shaped tarsal navicular
  - Do not confuse with multiple ossification centers without increased density.
- Bone scan:
  - Decreased uptake, or “cold area”
  - May be present before x-ray changes (1)
- MRI:
  - Rarely needed
  - Low signal on T1 and high signal on T2
Iselin disease:
- Radiographs:
  - Anteroposterior and lateral foot often miss.
  - Must include medial oblique view
  - Consider comparing with unaffected side
  - Apophyseal widening and often fragmentation of ossification center
  - Found almost parallel to long axis of shaft
  - Occasionally, with cystic changes of physis

Pathological Findings

Accessory navicular: Histologically, microfracture, acute and chronic inflammation, and cellular proliferation in symptomatic lesions

Differential Diagnosis

Accessory navicular:
- Navicular pathology (stress fracture, tuberosity avulsion fracture)
- PTT pathology (tendinopathy, tenosynovitis, rupture, dysfunction)
- Less commonly: Deltoid/spring ligament injury, tarsal tunnel syndrome, Köhler disease (in younger patients), tarsal coalition, plantar fasciitis, tight heel cord
- Systemic: Infection, malignancy
Köhler disease:
- Accessory navicular, trauma, stress fracture, infection, malignancy
- If not better with conservative treatment, rarely tarsal coalition (congenital or acquired)
Iselin disease:
- Fractures: 5th metatarsal (acute Jones and stress more transverse line), avulsion fracture (more common with lateral ankle sprains and more oblique line)
- Os vesalianum (incidence 0.1–1%; most often asymptomatic; found within peroneus brevis tendon)

Treatment

Accessory navicular: Rest, shoe insert/orthotic (soft orthotic initially until pain-free; then assess mechanics to see if semirigid orthotic is better for longer-term support), analgesics, physical therapy, occasionally cast immobilization
Köhler disease:
- If mild disease, soft arch supports only
- Short-leg cast (10–15 degrees of varus, 10–20 degrees of equinovarus) for 6–8 wks followed by arch support if mild pain persists
- Casting may lead to shorter length of pain.
- No significant difference in final outcome between short-leg cast and shoe correction, rest, or non-weight-bearing with crutches (2,3)[C]
- Symptom duration: 8+ wks of casting: 2.5 mos; <8 wks of casting: 4 mos; noncasting: 15.2 mos (3)[C]
Iselin disease:
- Rest, ice, calf stretching
- If severe pain, immobilization × 2–4 wks (aircast, walking cast, or short-leg cast with crutches)
- Physical therapy to improve strength and coordination when pain-free

Medication

Analgesics (eg, acetaminophen and NSAIDs) for pain

Additional Treatment

General Measures

Accessory navicular: Application of doughnut pad over bony prominence

Surgery/Other Procedures

Accessory navicular:
- Indication: No improvement with nonoperative treatment
- Resection of symptomatic bone with Kidner procedure ± reattachment of PTT (4)[C]
- Possible percutaneous drilling in young athletes (5)[C]
Iselin disease:
- Indication: Failure of conservative treatment and symptomatic nonunion
- Very rarely indicated
- Resection or fixation of symptomatic bone (6)[C]

Ongoing Care

Prognosis

Accessory navicular:
- Most do not become painful.
- Painful lesions in adolescents often improve with growth.
- Uncertain prognosis for symptomatic lesion treated nonoperatively
- Continued symptoms more likely with recurrent stresses of athletics
- Anecdotally, less likely to improve in physically active youth owing to repeated injury
- Uncertain if bony union is natural course (10–50% fusion reported)
Köhler disease:
- Self-limiting and excellent prognosis
- Full reconstitution of tarsal navicular (6–13 mos, average 8 mos) (2)[C]
- No evidence of arthritis long term (2,3)[C]
- Potentially, minor faceting of tarsal navicular (3)[C]
Iselin disease:
- Pain resolves with relative rest, immobilization, or eventual bony union.
- Rare reports of nonunion and prolonged symptoms

References

1. Khoury J, Jerushalmi J, Loberant N, et al. Kohler disease: diagnoses and assessment by bone scintigraphy. Clin Nucl Med. 2007;32:179–181.

2. Ippolito E, Ricciardi Pollini PT, Falez' F. Köhler's disease of the tarsal navicular: long-term follow-up of 12 cases. J Pediatr Orthop. 1984;4:416–417.

3. Williams GA, Cowell HR. Köhler's disease of the tarsal navicular. Clin Orthop Relat Res. 1981;53–58.

4. Ray S, Goldberg VM. Surgical treatment of the accessory navicular. Clin Orthop Relat Res. 1983;61–66.

5. Nakayama S, Sugimoto K, Takakura Y, et al. Percutaneous drilling of symptomatic accessory navicular in young athletes. Am J Sports Med. 2005;33:531–535.

6. Ralph BG, Barrett J, Kenyhercz C, et al. Iselin's disease: a case presentation of nonunion and review of the differential diagnosis. J Foot Ankle Surg. 1999;38:409–416.

Additional Reading

Canale ST, Williams KD. Iselin's disease. J Pediatr Orthop. 1992;12:90–93.

Sella EJ, Lawson JP, Ogden JA. The accessory navicular synchondrosis. Clin Orthop Relat Res. 1986;280–285.

Ugolini PA, Raikin SM. The accessory navicular. Foot Ankle Clin. 2004;9:165–180.

Codes

ICD9

732.5 Juvenile osteochondrosis of foot
755.67 Congenital anomalies of foot, not elsewhere classified