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.

What You Should Know About The Cheilectomy And Corrective Osteotomy Procedures

      Once one decides to proceed with surgery, what are the options? We often speak of joint sparing versus joint destructive procedures. Each procedure has some specific indications. Let us discuss the options.       A large part of the decision-making process is the age and desired activity level of the patient. The surgeon will obviously approach young patients in their 30s differently than patients in their 70s. Our top three surgical procedures for hallux limitus include cheilectomy, corrective osteotomy (including Lapidus arthrodesis), and first MPJ arthrodesis.       Cheilectomy. Removal of the dorsal hypertrophic bone of the first metatarsal is a commonly used procedure in the treatment of hallux limitus. What can be done to increase the effectiveness of a cheilectomy? First of all, it is important to choose the procedure wisely. Do not ignore obvious structural faults that may be better addressed with an osteotomy or other corrective procedure. Secondly, it is vital to resect an adequate amount of bone to allow for a postoperative increase in dorsiflexion motion.       Our approach is to load the first ray and mark on the first metatarsal articular surface where the dorsal aspect of the base of the proximal phalanx lies. The dorsal metatarsal resection should be at or slightly below this line. A second point to consider is that there is usually degeneration of articular cartilage dorsal to this level. If you are not sure if you have taken enough bone, you probably have not. Lastly, it is important to appreciate the soft tissue constraints on normal first MPJ range of motion, especially if the limitation has been present for many years. Perform mobilization of the sesamoids and the flexor plantar plate.       Corrective osteotomy. Consider this approach to address structural deformities such as metatarsus primus elevatus and a long first metatarsal. In cases of a long first metatarsal and mild elevatus, a corrective plantarflexory and shortening head procedure is usually successful. With significant elevatus of the first metatarsal or in cases of a hypermobile first ray, we recommend a proximal correction of the deformity.       Our preferred approach, just as in cases of hallux valgus with hypermobility of the first ray, is the Lapidus arthrodesis of the first metatarsocuneiform joint. While many others advocate the use of proximal metatarsal osteotomies, we have found that the Lapidus provides excellent and reliable short- and long-term outcomes. Many different procedures, including the sagittal Z osteotomy, dorsal wedge, modified Chevron osteotomy, etc., have been described to achieve the desired result.

Pertinent Pearls On First MPJ Arthrodesis Procedures

      First MPJ arthrodesis. In the presence of significant joint degeneration, arthrodesis is usually the preferred approach. We have found this procedure to be predictable and definitive. It eliminates the painful joint and proper positioning of the fusion point will minimize the postoperative complications. We all know to fuse the joint in a dorsiflexed position but we have recently seen several joint fusions where this has been exaggerated and the patient cannot fit into shoes. We advocate the use of a sterile cutting board or other flat surface to load the foot to find the appropriate amount of dorsiflexion at the fusion site.       Other procedures that address hallux limitus include drilling and curettage of articular defects; phalangeal shortening and wedge osteotomies; first MPJ arthrodiastasis with external fixation; and first MPJ joint implant arthroplasty. Surgeons have traditionally utilized other procedures such as the Keller arthroplasty, which we do not advocate. Resection of the base of the proximal phalanx will alleviate a tight, painful, arthritic joint with a relatively easy postoperative recovery period. However, it does trade one mechanical disadvantage for another. It is common to find transferred stress to the second metatarsal. We feel there are better options.       Joint implant arthroplasty (hemi versus total) is another option in cases of joint degeneration. However, revision is difficult if this option fails so careful patient selection is paramount. Very active patients, who are going to have a hard time accepting a fusion because they cannot be off their feet for four to eight weeks, are the same patients who may end up getting transfer stress to the second metatarsal after a first MPJ replacement.

Can A Partial Joint Implant Be Effective?

      Partial joint implant. A newer technique to replace a damaged portion of the metatarsal head is the use of the HemiCAP implant (ArthroSurface). Careful review of the X-rays prior to surgery will often hint of a subchondral defect. In this scenario, we will often make sure an ArthroSurface implant is on hand during a planned cheilectomy procedure. If the lesion is of significant size, we have found the HemiCAP to be a superior alternative to simple subchondral drilling to stimulate fibrocartilage repair.       This alternative procedure also adds another option, especially in the middle-aged and elder groups, who are not candidates for total joint replacement, and who may not respond well enough to a cheilectomy due to the articular cartilage damage.

In Summary

      Hallux limitus is a common condition we see in our profession. The more we can do to fine-tune our techniques, the more favorable our outcomes will be. Keys to the successful treatment lie in astute identification of the etiologic factors, addressing them with the specific conservative treatment or surgical procedure, and always appropriately considering the patient’s age and activity level.       Dr. Franson is a podiatric surgeon at the University Foot and Ankle Institute in Valencia, Calif. He also works as an attending surgeon with the VA-West Los Angeles and Olive View/UCLA Medical Center.       Dr. Baravarian (shown at the left) is the Co-Director of the Foot and Ankle Institute of Santa Monica. He is an Associate Professor at UCLA Medical Center and is the Chief of Podiatric Surgery at Santa Monica/UCLA Medical Center. Dr. Baravarian may be reached at bbaravarian@mednet.ucla.edu.