Metatarsal Head Resurfacing: Does It Have A Place In Treating Hallux Limitus/Rigidus?
Hallux limitus occurs when a patient has decreased sagittal plane dorsiflexion of the great toe with the foot in a weightbearing or simulated weightbearing loaded position that is usually associated with a progressive, arthritic and painful condition of the first metatarsophalangeal joint (MPJ).
Functional hallux limitus is described as limited joint mobility with the foot in a loaded position versus normal range of motion in an unloaded position. Hallux rigidus can be defined as elimination of range of motion at the joint, and usually results from end-stage ankylosing of hallux limitus. According to the literature, normal gait requires approximately 60 to 80 degrees of hallux dorsiflexion. While one could argue this concept since the foot has several compensatory mechanisms that could lower this value, it does give a benchmark for diagnosis, treatment and surgery.
For completeness, we will mention but not expand on several etiologies that predispose hallux limitus. The many causative factors include but are not limited to the following: posttraumatic, microtraumatic as with repetitive trauma, an elongated or short first metatarsal, first ray hypermobility, first metatarsal primus elevatus and pes-plano-valgus deformities. Diagnosing each patient’s etiology is important and will better allow you to treat the patient whether it is with conservative therapies or surgery. One must address each of these factors, especially when determining the appropriate surgical procedure to recommend to the patient.
Upon the physical examination, one will see decreased hallux range of motion with tenderness at both mid- and end range of motion, crepitus, first ray hypermobility, associated pinch callus (tyloma) at the medial hallux, transfer metatarsalgia with or without lesions, flatfeet, posterior tibial tendon weakness, ankle equinus and first ray elevatus. There are also palpable dorsal, lateral and medial osseous prominences.
A Guide To Conservative Options
Podiatrists can treat hallux limitus conservatively as well as surgically. As with most foot pathologies, it is recommended that one exhaust all conservative modalities prior to surgical intervention. Conservative modalities include the following:
• Shoe gear modification. This includes extra-depth, wide, stiff or rigid soled shoes.
• Antiinflammatories. This includes oral or intraarticular injections.
• Orthotic therapy. One may use a prescription functional insert with a first ray cutout or depression to improve functionality of the joint complex by promoting first metatarsal plantarflexion. Alternatively, one may consider a Morton’s extension to jam or completely lock the first MPJ. In our experience, it can sometimes be more difficult than it seems to prescribe the proper orthotic. There is a trial and error period when it comes to finding the best orthotic modifications for your patients.
• Modification of activities. As stated previously, this is a progressive and destructive deformity that unfortunately sometimes requires surgical intervention.
When You Need To Address Mild Or Moderate Hallux Limitus With Surgery
When addressing hallux limitus as a surgical entity, one must incorporate both clinical and radiographic evaluation. It is our contention that one can classify hallux limitus as mild, moderate and severe. (Surgeons must also keep a global view and be able to recognize compound pathologies such as pes plano valgus deformity or possible gastrocsoleus equinus that one may need to address surgically prior to or in conjunction with the primary procedure.)