A 45-year-old ex-ballerina presents with a painful great toe and dorsal swelling as shown in Figure 14.1.

1 This patient had virtually no movement at her MTP joint. What terms are used to describe restricted movement at the first MTP joint?

2 Young patients with this condition often report that they have participated in competitive sport. Which sports are particularly bad for your toe and what other conditions will lead to the radiographic appearances shown in Figure 14.2?

Fig. 14.2

Radiograph of great toe

3 What functional variations may predispose a patient to this condition?

4 Outline an appropriate grading system.

5 What conservative treatments might lessen this patient’s pain?

Fig. 14.1

Dorsal bunion overlying hallux MTP joint

Hallux limitus/rigidus (aetiology/conservative management)

1 The dorsal prominence seen is indicative of underlying degenerative osteoarthritis and dorsal osteophyte formation. Limitation and absence of movement are termed hallux ‘limitus’ and ‘rigidus’, respectively.

2 Degenerative joint arthritis arises from direct cartilage damage, and players of any sport who kick a ball repetitively are prone to hallux rigidus. In American footballers the condition is labelled ‘turf toe’. Sepsis, inflammatory arthritis or excessive repetitive weight transfer (a similar factor to that causing osteochondritis of the second metatarsal head) all potentially lead to the same end result.

3 Metatarsus elevatus and first ray hypermobility, as occur secondary to abnormal stance phase pronation, are reportedly associated with an increased risk of acquiring hallux rigidus, although empirical data in support of these theories are lacking.

4 A number of grading systems are available for hallux rgidus. A five-point scoring system is provided in Table 14.1.

**Table 14.1** A five-point grading system for hallux rigidus (after Coughlin & Shurnas 2003)
Grade	Dorsiflexion	Radiographic findings	Clinical findings
0	40–60° and/or 10–20% loss compared with normal side	Normal	No pain: only stiffness and loss of motion on examination
1	30–40° and/or 20–50% loss compared with normal side	Dorsal osteophyte is main finding, minimal joint space narrowing, minimal periarticular sclerosis, minimal flattening of metatarsal head	Mild or occasional pain and stiffness, pain at extremes of dorsiflexion and/or plantarflexion on examination
2	10–30° and/or 50–75% loss compared with normal side	Dorsal, lateral and possibly medial osteophytes giving flattened appearance to metatarsal head, no more than ¼ of dorsal joint involved on lateral radiograph, mild to moderate joint space narrowing and sclerosis, sesamoids not usually involved	Moderate to severe pain and stiffness that may be constant: pain occurs just before maximum dorsiflexion and maximum plantarflexion on examination
3	≤10° and/or 75–100% loss compared with normal side. There is notable loss of MTP plantarflexion as well (often ≤10° of plantarflexion)	Same as in grade 2 but with substantial narrowing, possibly periarticular cystic changes, more than ¼ of dorsal joint space involved on lateral radiograph, sesamoids enlarged and/or cystic and/or irregular	Nearly constant pain and substantial stiffness at extremes of range of motion but not at mid-range
4	Same as in grade 3	Same as in grade 3	Same criteria as grade 3 but there is definite pain at mid-range of passive motion

5 Two factors produce symptoms and it may be important to address one or both of these. Firstly, as osteoarthritis of the MTP joint progresses, the joint space narrows, which leads to tendon and ligament contractures and associated stiffness. Secondly, osteophytes form around the margins of the joint, particularly dorsally and laterally, leading to a mechanical block to extension and sometimes hallux flexus.

Transient benefits may be gained from simple conservative treatments. Non-steroidal anti-inflammatory drugs, rest and elevation of the foot may all help if the toe is particularly sore. Intra-articular steroid injections provide short-term pain relief, but a rigid insole should restrict joint movement sufficiently to lessen pain (Fig. 14.3). A rocker on the sole is also worth fitting as this acts to offload the first metatarsal head by reducing the need for joint extension at ‘toe-off’ (Fig. 14.4). If these treatments fail, then patients will generally consider surgery.

Fig. 14.3

Carbonflex insole

Fig. 14.4

Rocker sole

Evidence

Patients with mild (grade I) hallux rigidus gained symptomatic relief for a median of 6 months following injection of steroid and manipulation of the joint.

Key Points

• Hallux limitus/rigidus is a degenerative condition.

• Painful joint extension prevents normal gait.

• A scoring system is available to aid decision making.

• In-shoe orthoses should be considered in grade I or grade II hallux limitus/rigidus.

• A rocker sole may be helpful.

Freiberg’s infraction

1 Osteochondritis of the second metatarsal head, termed Freiberg’s infraction, is a common, crushing-type osteochondritis leading to avascular necrosis. It most commonly arises in adolescent girls but may also affect boys. Although this patient does remember an episode of a painful foot as a youngster, she did not present until later life when she developed pain in her second MTP joint.

2 No. Most of the literature describes the cause as an insult to the blood supply of the open epiphysis of the metatarsal head. However, Figures 15.2a and 15.2b show radiographs of a 64-year-old man taken 4 years ago for a coincidental injury and then this year for recent forefoot pain. Clearly this shows the development of a ‘new Freiberg’s’ and is evidence that avascular necrosis of the metatarsal head can occur in later life.

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Fig. 15.2

(a, b) Radiograph of 64-year-old man: normal third MTP joint

3 The head of the metatarsal progressively collapses or ‘infracts’ into the avascular segment (Fig. 15.3). This leads to flattening of the metatarsal articular surface, head compression and loss of joint space. The later changes are those of secondary osteoarthritis (Fig. 15.4). The classic description of the pathology of Freiberg’s was provided by Smillie In 1967 and the five stages are summarized in Table 15.1.

Fig. 15.3

AP radiograph: infraction of second metatarsal head

Fig. 15.4

AP radiograph showing replacement arthoplasty of second MTP joint

**Table 15.1** Staging of Freiberg’s infraction (after Smillie 1967):
Stage 1	A fissure fracture develops in the ischaemic epiphysis
Stage II	Absorption of bone has taken place and the central portion begins to sink into the head, altering the contour of the articular cartilage
Stage III	Further absorption has occurred and the central portion sinks into the head leaving projections on either side. The plantar articular cartilage remains intact.
Stage IV	The plantar isthmus of articular cartilage has given way and the loose body separated. Fractures of the lateral and dorsal projections have occurred. Restoration of the anatomy is no longer possible. The epiphysis is probably closed at this stage.
Stage V	Final stage of flattening, deformity and arthrosis.

4 A rocker sole (Fig. 14.4) may be advantageous as it will aid dorsiflexion of the foot. Local injections of corticosteroid provide only short-term symptomatic relief.

5 In the older patient, where degenerative changes are the cause of discomfort, either a proximal hemiphalangectomy or, as in this case, a joint replacement arthroplasty will be required (Fig. 15.5). In younger patients, Gauthier’s procedure restores joint congruity by rotating the ‘normal’ dorsal cartilage onto the articulating surface (Fig. 15.6).

Fig. 15.5

Replacement arthroplasty

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Fig. 15.6

(a) AP and lateral radiograph of Gauthier’s procedure. (b) Illustration of Gauthier’s procedure (lateral view).

Key Points

• Freiberg’s infraction occurs mainly in adolescence but not exclusively.

• The condition is an avascular necrosis of the metatarsal head.

• Secondary osteoarthritis always develops.

• In older patients, replacement or resection arthroplasty may be necessary.

Hammer toe

1 The photograph shows the typical appearance of hammering of the second toe. It is potentially serious, particularly if healing is compromised as shown in Figure 16.2. This condition is distinguishable from claw toe (Fig. 16.3) in which there is greater flexion of the distal interphalangeal (IP) joint and dorsal subluxation of the MTP joint. In mallet toe the distal IP joint only is flexed (Fig. 16.4).

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Fig. 16.2

Terminal ulceration

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Fig. 16.3

Claw toe

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Fig. 16.4

Mallet toe

Hammer toe is often familial and usually gradually progressive from a young age. Frequently the second toe and/or the second metatarsal is abnormally long, i.e. the foot is ‘index minus’ or of ‘Greek’ type, respectively, and such a deformity leads to increased tension, at least on the medial aspect of the plantar aponeurosis. Direct pull onto the plantar plate and flexor tendon sheath at the level of the MTP joint explains the joint flexion. In the elderly, since the aponeurosis stretches out with age, there does have to be some dorsiflexion of the proximal phalanx before flexion of the PIP joint will occur.

2 PIP joint fusion is probably the most commonly performed surgical procedure for hammer toe. Articular cartilage is removed from the head of the proximal phalanx and from the base of the middle phalanx and the surfaces apposed. The fusion is held with a fine Kirschner wire or a biodegradable pin. Hohman has recommended excision of the head of the proximal phalanx and reefing of the dorsal extensor tendon only. We have generally found that this produces an inferior result to fusion, as some patients will experience continuing discomfort from the mobile joint. Hemiphalangectomy (Fig. 16.5) may leave a redundant and shortened digit and amputation produces gapping which in the case of the second toe will cause the hallux to move across into valgus (Fig. 16.6).

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Fig. 16.5

Appearance after proximal hemiphalangectomy

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Fig. 16.6

Hallux valgus deformity after second toe amputation with and without spacer

3 Pain elicited at the MTP joint on ‘drawing’ the toe dorsally on the metatarsal will signify joint instability. Resection of the IP joint does produce a relative lengthening of the dorsal extensor tendon that may be sufficient to prevent subluxation of the proximal phalanx dorsally on the metatarsal. If not, it is worthwhile performing a dorsal capsulotomy of the MTP joint and possibly also a transfer of the dorsal extensor tendon to the flexor below the metatarsal head. If this is still inadequate then a Weil’s sliding osteotomy may be required (Fig. 16.7 and Fig. 16.8).