I. Arthritides of the Ankle
A. Overview
1. Arthritides of the ankle are most often posttraumatic in origin.
2. Other causes
a. Inflammatory diseases
b. Chronic ligamentous instability
c. Osteonecrosis of the talus
d. Peripheral neuropathy (Charcot neuroarthropathy)
e. Primary degenerative disease (osteoarthritis [OA]).
3. OA of the ankle is less common than OA of the hip or knee.
B. Evaluation
1. History and physical examination
a. Patients typically report pain in the anterior ankle with weight bearing and push-off.
b. Pain may be with ankle range of motion during physical examination.
c. The tibiotalar motion arc is typically reduced when compared to that of the unaffected ankle.
d. The ankle and lower limb should be evaluated with the patient standing. This allows the examiner to assess alignment of the ankle and hindfoot (
Figure 1, A).
2. Imaging—Weight-bearing AP, oblique, and lateral radiographs of the ankle should be obtained to assess joint-space narrowing and alignment of the ankle. Consideration should be given to standard weight-bearing radiographs of the foot to assess foot alignment.
C. Treatment
1. Nonsurgical
a. Nonsteroidal anti-inflammatory drugs (NSAIDs)
b. Activity modification
c. Corticosteroid injections—Selective (fluoroscopically guided) anesthetic/corticosteroid injections can be both diagnostic and therapeutic.
d. Shoe modifications (rocker soles)
e. Bracing (ankle-foot orthosis [AFO])
2. Surgical
a. Ankle debridement with anterior tibial/dorsal talar exostectomy
i. Relieves impingement during push-off.
ii. Often improves symptoms in mild disease.
iii. May worsen symptoms because of increased tibiotalar motion.
b. Distraction arthroplasty for mild disease remains controversial.
[Figure 1. Radiographs of the ankle in a patient with chronic ankle instability and resultant end-stage post-traumatic OA. A, AP view showing varus tilt of the talus within the ankle mortise. B, AP view after arthrodesis via a transfibular approach.]
c. Supramalleolar osteotomy
i. Symptoms secondary to tibiotalar malalignment and eccentric articular wear may benefit from supramalleolar osteotomy to offload arthritic areas.
ii. Supramalleolar osteotomy is indicated for mild or moderate arthritis of the ankle when there is malalignment of the ankle joint with reasonably maintained range of motion.
d. Arthrodesis
i. Arthrodesis is the gold standard treatment for end-stage arthritis of the ankle (Figure 1, B).
ii. Described methods of tibiotalar arthrodesis include arthroscopic, mini-arthrotomy, and open techniques, with either internal or external fixation.
iii. Ring external fixation is a surgical alternative to internal fixation in complex ankle arthrodesis when previous surgery or extensive trauma compromises the soft-tissue envelope of the ankle.
iv. The recommended positioning of the ankle for arthrodesis is neutral plantar flexion and dorsiflexion, hindfoot valgus of 5°, and rotation equal to the contralateral limb.
v. Complications of arthrodesis
(a) Reported rates of nonunion may exceed 10%.
(b) Tobacco use affects healing time adversely, with smokers having a 2.7 times greater risk of nonunion and delayed healing than nonsmokers.
(c) Adjacent-joint (hindfoot) arthritis eventually develops in most patients who undergo ankle arthrodesis, even when successful fusion and appropriate ankle alignment have been achieved.
(d) Long-term follow-up studies have demonstrated that ipsilateral adjacent hindfoot (subtalar) arthritis may develop after uncomplicated ankle arthrodesis.
e. Total ankle arthroplasty
i. Total ankle arthroplasty is an alternative to arthrodesis, especially for elderly patients with end-stage arthritis and physiologic ankle and hindfoot alignment.
ii. Long-term follow-up of modern implants (particularly complication rates) is warranted to determine advantages over ankle arthrodesis.
D. Rehabilitation—Postoperative physical therapy is procedure-dependent. In general, ankle arthrodesis necessitates a minimum of 8 weeks of protected weight bearing.
II. Arthritides of the Hindfoot
A. Overview
1. The hindfoot articulations include the subtalar, talonavicular, and calcaneocuboid joints.
2. Arthritides of the hindfoot may develop from trauma (calcaneus or talus fractures), inflammatory arthritides, primary arthritis (OA), end-stage posterior tibial tendon disorders, tarsal coalitions, or neurologic disorders that are associated with long-standing cavovarus foot posture.
3. Arthritides of the hindfoot are most often post-traumatic in origin.
4. Hindfoot arthritis secondary to posterior tibial tendon dysfunction is often associated with Achilles tendon contracture.
5. Isolated talonavicular joint arthritis is associated with inflammatory arthropathy (rheumatoid arthritis [RA]).
B. Evaluation
1. History and physical examination
a. Patients with hindfoot arthritis generally report pain and/or swelling at the sinus tarsi, particularly when walking on uneven surfaces.
b. Inversion and eversion of the hindfoot reproduce pain.
c. Motion is typically limited compared to the uninvolved side.
d. The patient should be examined while standing (weight bearing) to identify potential malalignment.
2. Imaging
a. Weight-bearing radiographs demonstrate loss of joint space and malalignment of the bones in the hindfoot (
Figure 2, A).
b. Although Broden and Harris radiographic views may better define the extent of subtalar arthritis than standard radiographic views, CT scanning may be warranted to provide greater detail of hindfoot arthritides.
C. Treatment
1. Nonsurgical
a. NSAIDs
b. Activity modification
[Figure 2. Lateral radiographs of the foot in a patient with posttraumatic subtalar arthritis, subtalar coalition, and calcaneal malunion. A, Preoperative view. B, Radiograph obtained after subtalar arthrodesis and calcaneal osteotomy to realign the hindfoot and restore hindfoot height.]
c. Shoe modifications (stiff, rocker soles)
d. Bracing that protects the hindfoot
i. University of California Biomechanics Lab (UCBL) orthosis
ii. Rigid or hinged AFOs
e. Corticosteroid injections
f. Selective (fluoroscopically guided) anesthetic/corticosteroid injections are sometimes therapeutic, but they typically serve to identify the symptomatic hindfoot articulation(s).
2. Surgical
a. Arthrotomy (or, in select cases, arthroscopy) may prove successful to debride hindfoot articulations and remove symptomatic exostoses or loose bodies.
b. Lateral calcaneal exostectomy after calcaneus fracture is often effective in relieving subfibular impingement.
c. Arthrodesis
i. Arthrodesis is typically recommended for hindfoot arthritis (Figure 2, B).
ii. Selective arthrodesis of a hindfoot articulation is indicated for isolated arthritis.
iii. Isolated calcaneocuboid, subtalar, and talonavicular joint arthrodeses limit hindfoot motion by approximately 25%, 40%, and 90%, respectively, prompting many surgeons to recommend triple arthrodesis when talonavicular joint arthrodesis is warranted.
iv. Triple arthrodesis is the recommended treatment for stage III posterior tibial tendon dysfunction that is unresponsive to nonsurgical treatment.
v. Some authors recommend subtalar bone block distraction arthrodesis to re-establish physiologic hindfoot alignment when associated loss of heel height and anterior ankle impingement are present.
vi. Techniques for hindfoot arthrodesis include internal fixation with screws and/or staples.
vii. The recommended position for hindfoot arthrodesis maintains or re-establishes a plantigrade foot, with approximately 5° of hindfoot valgus and a radiographically congruent talus-first metatarsal axis (Meary line) on both AP and lateral weight-bearing radiographs.
viii. The desired position for triple arthrodesis is 5° to 7° of hindfoot valgus and a congruent talus-first metatarsal angle on the AP and lateral radiographs (0°).
ix. The union rate for isolated subtalar arthrodesis is 88% to 96%. In a triple arthrodesis, the most common joint not to fuse is the talonavicular joint.
III. Arthritides of the Midfoot
A. Overview
1. The midfoot articulations include the naviculocuneiform and metatarsocuneiform/cuboid joints.
2. Midfoot joints may be viewed as nonessential joints, and if fused in anatomic alignment, physiologic foot function is generally anticipated.
3. The etiology of midfoot arthritis can be primary, inflammatory, or posttraumatic.
4. Primary OA of the midfoot is the most common type of midfoot arthritis.
[
Figure 3. Radiographs of the foot in a patient with posttraumatic midfoot OA following a Lisfranc fracture-dislocation that was initially treated nonsurgically. A, Preoperative AP view demonstrates severe forefoot abduction. B, Preoperative lateral view demonstrates loss of the longitudinal arch. C, AP view obtained after midfoot arthrodesis realignment demonstrates medial alignment and restoration of the longitudinal arch.]
5. Untreated third tarsometatarsal (TMT) joint (Lisfranc) fracture-dislocation typically leads to loss of the longitudinal arch and forefoot abduction.
B. Evaluation
1. History and physical examination
a. Patients report midfoot/arch pain with weight bearing, particularly with push-off during gait.
b. Pain is elicited with palpation or stress.
c. Pain on bony prominences of the midfoot may be present.
d. Loss of the longitudinal arch (sometimes associated with forefoot abduction) is frequently seen with weight bearing.
e. Secondary hindfoot valgus, Achilles tendon contracture, and hallux valgus may also be present.
2. Imaging—Weight-bearing radiographs of the foot demonstrate a nonlinear talus-first metatarsal relationship with the apex of the deformity at the midfoot. This deformity produces a loss of the longitudinal arch and forefoot abduction (Figures 3, A and 3, B).
C. Treatment
1. Nonsurgical
a. NSAIDs
b. Activity modification
c. Longitudinal arch supports
d. Shoe modifications (rocker soles)
e. Fixed-ankle bracing in combination with shoe modifications (rocker soles) may further unload the midfoot during gait.
f. Fluoroscopically guided corticosteroid injections are diagnostic and potentially therapeutic.
2. Surgical
a. Near full physiologic foot function, in particular during push-off, can be reestablished with successful realignment and arthrodesis of the first through TMT and/or naviculocuneiform joints. The fourth and fifth TMT joints are not fused, in order to preserve the accommodative function of the foot during the stance phase of gait (Figure 3, C).
b. Internal fixation of the midfoot articulations has evolved to include screws, staples, and plates specifically indicated for midfoot arthrodesis.
3. Pearls and pitfalls
a. Select cases of symptomatic fourth and fifth TMT joint arthritis diagnosed through the use of selective corticosteroid joint injections may be treated with interpositional arthroplasty, which maintains the lateral column and accommodates gait.
b. TMT joints are 2 to 3 cm deep; full joint preparation must extend to the plantar surface to optimize physiologic alignment and fusion.
c. Severe deformity may warrant a biplanar midfoot osteotomy in conjunction with arthrodesis, particularly in nonbraceable Charcot midfoot deformity.
d. Given the high prevalence of midfoot arthritis following Lisfranc injury, primary arthrodesis may be considered.
e. Surgical management of arthritides of the midfoot may warrant simultaneous Achilles tendon lengthening and hindfoot realignment.
IV. Arthritides of the Forefoot
A. Overview
1. Arthritides of the forefoot most commonly affect the first metatarsophalangeal (MTP) joint (hallux rigidus). The most likely etiology is repetitive trauma, but metabolic (gout) or inflammatory conditions (eg, RA) also may be contributing factors.
2. Arthritis of the forefoot involving the lesser MTP joints is typically inflammatory (eg, RA) and rarely occurs secondary to osteonecrosis of the lesser metatarsal head (Freiberg infraction).
3. Hallux rigidus refers to degenerative joint disease of the first MTP joint.
B. Evaluation
1. History and physical examination