Key Insights On Treating Hallux Limitus
Hallux limitus, by definition, is a decrease in sagittal plane dorsiflexion of the hallux at the first metatarsophalangeal joint (MPJ) when the foot is in a weightbearing or simulated weightbearing position. With this in mind, let us take a closer look at the treatment approaches to this condition.
Normal range of dorsiflexion motion of the first MPJ should be 65 to 75 degrees in order to allow for a normal gait. Near the end of the propulsive phase of gait, the leg has a 45-degree position to the floor and the ankle is in about 20 degrees of plantarflexion to the leg. This position requires the hallux to be able to dorsiflex 65 degrees. Anything less requires accommodation or adaptation from the surrounding joints. This compensation can come from gait changes, such as subtalar joint supination and walking on the outside of the foot, subtalar joint pronation with foot abduction, etc.
We often speak of functional versus structural hallux limitus. A decrease in joint motion in the loaded and unloaded foot is structural hallux limitus. In regard to functional hallux limitus, there is limitation only when the foot is weightbearing or loaded.
Understanding The Evolution And Degrees Of Hallux Limitus
The mechanical fault of hallux limitus over time can cause articular damage to the first MPJ and can also have a negative impact on the surrounding joints and tissues. Joint degeneration over time can lead to joint ankylosis or hallux rigidus.
It should be noted that most of the orthopedic literature uses the term “hallux rigidus” instead of “hallux limitus.” In the podiatric literature, we typically
refer to hallux rigidus as the end stage of hallux limitus, when motion is absent or severely restricted to the point of near ankylosis.
There are several different grading systems for hallux limitus/rigidus. A generic and very general summary of the hallux limitus classification using a four-stage outline is as follows:
Grade I: limited motion of the first MPJ, mild pain, no significant degenerative joint disease (DJD), minimal osteophyte
Grade II: limited motion, pain, early DJD, osteophyte
Grade III: limited motion, pain, DJD, osteophyte
Grade IV: joint ankylosis, end stage DJD
The classification system is important because it can help dictate the treatment approach. The problem, however, is that it does not take into account the age of the patient or the specific etiology. Both of these factors are of utmost importance in treatment and procedure selection.
The etiologies or contributing factors in the development of hallux limitus include the following: a long first metatarsal/first ray; a hypermobile or immobile first ray; osteochondral lesion; degenerative joint disease of the first MPJ; trauma; elevated first ray; first metatarsal head morphology (square head); and soft tissue constraints including tightness of the flexor hallucis brevis and the sesamoid apparatus. More often than not, we find a combination of factors that contribute to the development of hallux limitus.
A Guide To Conservative Treatments
In addition to antiinflammatory medications, the nonoperative approaches to the treatment of hallux limitus include efforts to increase or restrict motion of the first MPJ. One may incorporate physical therapy to mobilize functional motion loss of the first MPJ. Indications for custom orthotics with accommodations to increase first MPJ range of motion include cases with a functional hallux limitus without much evidence of joint degeneration. These are typically the younger patients without a long history of joint pain.
Most patients with chronic joint pain will respond better to efforts to limit stress and motion through the first MPJ. One can decrease stress by utilizing orthotics with a Morton’s extension, stiff-soled shoes, a metatarsal bar and rocker-bottom shoes.
Use intraarticular steroid injections sparingly. The goal of conservative treatment is to allow an active lifestyle with minimal to no pain in the first MPJ. If one cannot achieve this with the aforementioned options, consider surgery.