Chapter 72 What Is the Best Treatment for End-Stage Hallux Rigidus?
Hallux rigidus is the commonest form of osteoarthritis in the foot with an incidence of 1 in 40 adults older than 50 years, and it is the second commonest complaint of the great toe behind hallux valgus.1–3
Radiographic evaluation reveals findings consistent with osteoarthritis, which includes joint space narrowing, osteophyte formation (particularly dorsally), subchondral cysts, and sclerosis. Hattrup and Johnson4 developed a radiographic classification of hallux rigidus, which was divided into three grades. In grade I, mild-to-moderate osteophytes are present; however, there is preservation of the joint space. In grade II, there is moderate osteophyte formation with narrowing of the joint space and subchondral sclerosis. Grade III is characterized by marked osteophyte formation, loss of the joint space, and subchondral cysts may be present.
SURGICAL TREATMENT
Noncomparative Studies (Case Series; Level IV)
Cheilectomy.
A cheilectomy entails excision of the dorsal osteophyte together with a portion of the dorsal degenerative articular surface. It is recommended to remove up to a third of the articular surface with the goal to obtain a minimum of 70 degrees of dorsiflexion. Usually included with the procedure is the resection of any dorsal osteophytes off the proximal phalanx, debridement of the joint, loose body removal, and synovectomy.5,6
Cheilectomy has been shown to have good results in early stages of hallux rigidus.4,7 Some authors have reported good clinical results for cheilectomy irrespective of radiographic grade.4–6 No study exists that isolates the subset of patients with advanced hallux rigidus. The largest published series is reported by Coughlin and Shurnas7 where 93 feet of all stages of hallux rigidus underwent a cheilectomy and were reviewed retrospectively, with an average follow-up period of 9.6 years. Of the nine feet that had end-stage radiographic changes, five did not respond to treatment and underwent arthrodesis at a mean of 6.9 years after cheilectomy.7 Easley and coworkers8 conducted a retrospective review of 68 feet of all stages treated with cheilectomy at an average follow-up period of 5 years. A 90% satisfaction rate was achieved in the entire group. Of the nine feet that remained symptomatic; eight of those had end-stage grade 3 changes. It was noted that all nine demonstrated pain at the midrange of the motion arc, which would be suggestive of more global and advanced degenerative changes in the hallux MTP joint. The authors conclude that this was a negative prognosticator after cheilectomy.8 Based on these two Level IV studies, a cheilectomy cannot be recommended for treatment of end-stage hallux rigidus (grade C level of recommendation).
Keller Resection Arthroplasty.
In 1904, Keller described a procedure that involved excision of a portion of the proximal phalanx of the hallux for the treatment of hallux valgus and associated osteoarthritis of the first MTP joint. Although this procedure decompresses the joint, excessive resection can lead to instability secondary to loss of both bone and soft-tissue restraints. Shortening of the great toe occurs, and the plantar aponeurosis is disrupted, which impairs the windlass mechanism contributing to the decreased stability of the medial column. Commonly described complications include transfer metatarsalgia, weak push off, and a cock-up deformity of the toe, which has led many investigators to recommend this procedure for low-demand and older patients.9,10
When reviewing the results of the Keller arthroplasty, variable outcomes are found with few being prospective or comparative trials. No studies review the subset of younger or higher demand patients. In addition, many studies also include hallux valgus deformities and lack any uniformity on grading or outcome measures, particularly older studies. Love and coworkers10 performed a prospective trial studying 75 feet in patients with hallux valgus and hallux rigidus. Inclusion criteria included age older than 50 years, symptomatic osteoarthritis of the first MTP joint, and relatively low demand as defined by occupation and lifestyle. No differentiation was reported in radiographic grade of the osteoarthritis present in the first MTP joint. Mean follow-up period was 31 months. The authors report that joint pain was alleviated in 40 of 44 patients with an overall satisfaction rate of 77%. No increased incidence of postoperative metatarsal callosities occurred. However, they report a cock-up deformity after surgery in 28 feet compared with 8 before surgery, as well as a slight decrease in first MTP joint motion after surgery.10
Biologic Interpositional Arthroplasty.
Hamilton and colleagues12 performed a retrospective review on 30 patients with advanced hallux rigidus who were treated with an EHB tendon and capsular interpositional arthroplasty collected over 10 years. However, the follow-up time is unknown. Subjectively, 93.3% of patients reported that they would undergo the same procedure. The American Orthopaedic Foot and Ankle Society (AOFAS) pain scores improved from 23.2 points before surgery to 37.4 points after surgery, and the average dorsiflexion improved from 10 to 50 degrees. No patients described weakness in push off or lateral metatarsalgia, and no calluses were found underneath the metatarsal heads.12 Kennedy and coworkers13 retrospectively reviewed 18 patients (21 feet) over a mean follow-up period of 38 months who underwent capsular interpositional arthroplasty utilizing the EHB tendon. Eighteen of 21 feet were grade 3 radiographically, whereas the remainder were grade 2. All 18 patients had pain relief, whereas 17 reported they would have the same procedure repeated. The mean postoperative increase in dorsiflexion was 37 degrees. One patient reported transfer metatarsalgia. The authors13 conclude that interpositional arthroplasty was indicated for treatment of advanced hallux rigidus, and the technique as described by Hamilton and colleagues12 had reproducible outcomes. However, Lau and Daniels1 used a similar technique and retrospectively reviewed a series of 11 patients with a mean follow-up period of 2 years. Ten of 11 patients were grade III radiographically, whereas the other patient was grade II. Patient satisfaction was 72.7%. However, weakness of the great toe was reported in 72.7% of patients, whereas 27.3% reported lateral metatarsalgia. The investigators conclude that interpositional arthroplasty should be considered a salvage procedure with less reliable results.1
Barca14 reports on the use of the plantaris tendon as the biologic spacer that was combined with a 20- to 30-degree dorsal wedge osteotomy of the proximal phalanx. An articulated external fixator was used to maintain the diastasis of the joint. Barca retrospectively reviewed a series of 12 patients over a period of 21 months. All patients reported good or excellent results, and dorsiflexion was improved by an average of 44 degrees. Coughlin and Shurnas15 used a gracilis tendon as a graft and retrospectively reviewed seven patients over an average of 42 months of follow-up. All seven patients rated their result as good or excellent with a mean increase in AOFAS scores from 46 to 86. Mean dorsiflexion improved from 9 to 34 degrees and all demonstrated good to excellent plantarflexion strength. Four patients did report mild metatarsalgia. The authors conclude that this technique gave excellent pain relief and reliable function of the hallux.15
Arthrodesis.
Arthrodesis of the first MTP joint has been one of the mainstays of surgical treatment of severe hallux rigidus, particularly in the younger, more active population. This procedure eliminates the painful movement of the joint and provides a stable medial column for ambulation. However, it has not been without controversy. An arthrodesis has a prolonged recovery course compared with other procedures, and there are complications such as nonunion, progressive arthrosis of the interphalangeal joint, and lateral metatarsalgia.16 The long-term success and the impact on the gait cycle have also been a concern.