Considering Comprehensive Treatment Options for Hallux Limitus/Rigidus

One of the most common presenting problems to any foot and ankle surgeon is hallux limitus or rigidus. I believe this problem is often underrated due to the differing levels of damage and arthritis, lending itself to greater complexity and resultant under- or overtreatment. Many cases are not a simple fix and many may not require end-stage intervention such as fusion. In my experience, most cases are in-between, with a moderate level of arthritis and joint damage but not enough to require end-stage treatment. As a surgeon, how can we offer options to our patients? Which ones work? Which ones are new and an opportunity to maybe offer something different to our patients? In this piece, I will update readers on my thinking on hallux limitus and rigidus in hopes of helping others with the decision-making process.

What Causes Hallux Rigidus?

Currently there is no single answer to this question. There are a variety of ideas presented, which all seem viable.¹ These range from a single traumatic event that begins an arthritic cascade to a continuous low-level traumatic event, possibly biomechanical in nature. Over time, the cascade results in joint spurring, joint space narrowing and decreased range of motion to the great toe joint.¹ What is ironic is that not all presenting cases are painful. Whatever the cause of the cascade, the idea to remember is that this is the beginning of a progressive disease that results in joint space narrowing, arthritic changes and decreased range of motion in the great toe.

Diagnostic Pearls to Remember

In my opinion, diagnosis of hallux limitus or rigidus is quite simple. Move the toe, feel for crepitus, feel for a spur and note any limitation in range of motion. To end it there is the simplistic approach and one we must avoid. The issue is far more complicated. To begin with, what is the foot type? Is there a flat, neutral, or cavus foot? Is there hypermobility of the first ray causing elevation and jamming? Is there an underlying long first metatarsal? How is the motion of the great toe joint if one stabilizes the first metatarsal and holds it in anatomic position? How is the motion of the great toe when one allows the first metatarsal to ride into the position it is currently with standing and full weight?  All these factors warrant consideration in deciding what to do for the patient.

In checking the great toe joint, the degrees of range of motion is important, as is the quality of the motion. However, be aware that it is possible to note no motion in the dorsal part of the excursion from an elevated first metatarsal or dorsal spurring, but the central range of motion or mid-portion of the excursion is smooth. The opposite can be true, in that I have seen excellent range of motion with horrible crepitus during movement. Keep this in mind in during your decision making.

It is important to order the proper diagnostic testing in conjunction to one’s examination. We always begin with standard radiographs (full weight-bearing anterior-posterior, medial oblique and lateral). Adding in a sesamoid axial view is not a bad idea to look at the position and quality of the sesamoid complex. What I look for in radiographs is the position of the metatarsal, the degree of joint space narrowing and the degree of spur formation. What is the quality of the great toe joint? However, don’t forget to also check the overall position and alignment of the foot.

What I have realized is that with standard radiographs alone, I miss a significant amount of diagnostic information that led me to some suboptimal results. I feel this may have proven avoidable if I had additional information. I thought some cases were simple cheilectomy procedures that I later found that osteochondral lesions primarily caused the pain. Others seemed to have smooth and fluid motion in the central aspect of the joint, which ended up having far worse arthritic changes than I expected when I opened the joint. The question is; how can we know the quality of the joint and the health of the cartilage and bone prior to surgery?

I now use both computerized tomography (CT) and magnetic resonance imaging (MRI) for advanced diagnostics prior to surgery. This imaging is not necessary for every patient, but with surgical patients, I feel it is not a bad idea. Let me add that if the joint is obliterated and there is no doubt you would like to do a fusion, advanced diagnostics may not be necessary.  However, a mild, but very painful, dorsal spur may have an osteochondral lesion to address, which would be helpful to know prior to surgery.

CT is, in my observation, overall a great exam to show anatomic position of the metatarsal, the level of dorsal spurring, and the actual jamming angle of the joint. A weight-bearing CT is preferrable, as I feel this gives true positional information. What I prefer to use more often is an MRI of the great toe joint. I find it more useful to help me diagnose osteochondral damage, subchondral damage to the metatarsal head, and to check the overall quality of the cartilage prior to surgery. This helps me plan my procedure and avoid an intraoperative surprise.

Conservative Options First, Right?

One can treat hallux limitus and rigidus conservatively.¹ This is commonly done with rigid-soled shoes, carbon plates in the shoe sole and orthotics with a Morton’s extension of the shell. All of these can help and are appropriate to try. Hyaluronic acid, platelet-rich plasma, bone aspirate concentrate and amniotic injections in my experience, all can help reduce pain in patients with this condition. However, are we doing the right thing avoiding surgery?

The answer is again, complex. What is the age of the patient, how active are they,what do they expect out of their toe, and can I make it better now and avoid larger issues or limited options in the future? All of these are relevant queries to consider. In my eyes, I tell all patients that hallux limitus and rigidus are progressive problems, and with time the options may become more limited. I offer them conservative options, but also discuss the current state of their joint and what is necessary surgically now versus what may become necessary down the road. Again, joints that are completely destroyed and need a fusion can wait as long as the patient can tolerate. Joints that have no major spur or osteochondral issue, but may be just starting to have a biomechanical problem may also not need a surgical procedure. The main issue is, should we wait on treating an earlier case of moderate hallux limitus and let it progress to a late stage issue, or treat it early for the best result? I offer the patient the options and try and guide them to early surgical treatment to avoid long-term option limitations.

Surgical Options to Consider

I divide my treatments of hallux rigidus in to early-, mid-range- and late-stage. Early cases usually have some biomechanical issues, such as an elevated or long first metatarsal, but may also just have a spur from trauma. Be suspicious for osteochondral lesions in early cases if the pain seems out of proportion. For early cases, I perform a cheilectomy, decompression osteotomy and cartilage repair procedures. I also have an allograft wrap available in the surgical facility in case the problem is far worse than expected.

On late-stage cases, I really only offer fusions. If the arthritis is not in the sesamoid complex and range of motion is moderate in nature, at times I will offer a joint replacement option. In such cases, I prefer to only replace the metatarsal head with a Toe HemiCAP (Anika Therapeutics) implant.  I personally find this is solid, stable, and subsidence is not common.

The mid-range cases may require one or more combined treatments and a slew of options for proper planning. In such cases, I perform cheilectomy with or without a decompression osteotomy, subchondral and/or chondral treatment with cheilectomy and possible decompression osteotomy, joint replacement and possible metatarsal head wrap.  There are multiple options, and the MRI and diagnostics help to guide what I want to do.

The main point is, consider the options and be ready for anything, even more than you expected, so you don’t get burned and you continuously offer high-level care to the patient.  That way you are on top of the problem before it arises. Here are a few of my thoughts on procedure selection:

If I do a cheilectomy, I will err on the side of being more aggressive than I think I need to. The dorsal one-third of the metatarsal head, I find, is a good option. I load the metatarsal and put the toe through range of motion to see if there is catching or jamming. If the catching is mild, I will remove a bit more dorsal bone. If the catch is significant, I have the patient pre-consented for a decompression osteotomy.

I perform an L-type decompression osteotomy and angle the dorsal arm of my cut a bit distal to a perfect 90-degree L. This allows the metatarsal to plantarflex a bit with decompression which is preferrable. Fixation is with a single screw or two, OSSIOfiber trimmable fixation (OSSIO) 2.4 mm nails, one from dorsal-proximal to distal-plantar and one from medial-proximal into the lateral metatarsal head.

Special Considerations for Subchondral Pathology

A new and evolving issue that we see and deal with is subchondral bone edema with or without cartilage damage. I use two options to deal with this issue. The first is Subchondral Solutions, a disc that placed through a drill hole in the area of cartilage and subchondral damage. This allows fibrous infill that I find acts like cartilage and works well for osteochondral lesions with subchondral damage. If this is not available, or there is cartilage damage only, I may use the patient’s own cartilage to treat the lesion. I will debride the cartilage from the dorsal spur region and top one-third of the joint and morselize it. I then drill my osteochondral lesion with a small K-wire and place a small amount of fibrin glue, then the cartilage, and top it with more fibrin glue. In this way I am laying down live cartilage cells and allowing a scaffold for in-growth.

So, to be clear, subchondral bone damage and edema requires a deeper repair, such as Subchondral Solutions. With that system, I have found I can also sew on an amniotic layer over, or a bovine myocardium layer onto the cartilage surface of the implant. In my experience, this adds a layer of cushion for larger defects. Superficial cartilage defects found by chance or with no deep damage can be treated with an auto-cartilage repair.

Finally, does one do for mass cartilage loss or poor quality cartilage that you find or plan for?  Well, there are two options. The first is an unplanned poor cartilage find. For this I will use the dorsal capsule and dissect it off the base of the phalanx, leaving it connected proximally. I then pull the capsule into the joint, sew over it with a layer of amniotic membrane and use it as an interpositional graft. I will place two small anchors on the plantar anterior metatarsal head and tie the capsule and amniotic layer down with the suture off the anchors. For a planned interpositional arthroplasty, I will perform the cheilectomy and then use a planned, thick membrane material with an anchor system. Arthrex has an excellent option that helps cover the plantar and dorsal surfaces of the joint. If you plan ahead, a Toe HemiCAP is also a good option.

In Conclusion

Hopefully I have left you with enough to think about in considering potentially new or alternative options for hallux limitus and rigidus cases outside of your usual algorithms.  With appropriate planning, a comprehensive consent that offers you options at the time of surgery, proper surgical technique, and hopeful restoration to pain-free improved function of the great toe joint is something many patients will benefit from. 

Dr. Baravarian is an Assistant Clinical Professor at the UCLA School of Medicine. He is the Director and Fellowship Director at the University Foot and Ankle Institute in Los Angeles (https://www.footankleinstitute.com/podiatrist/dr-bob-baravarian).

Dr. Baravarian discloses that he is a consultant, shareholder and head of foot and ankle advisory for OSSIO, and a consultant for Subchondral Solutions.

References

1. Ho B, Baumhauer J. Hallux rigidus. EFORT Open Rev. 2017;2(1):13-20.