Arthritis And The Bunion: Current Concepts

Osteoarthritis of the first metatarsophalangeal joint may lead to patients having symptoms of both hallux valgus and hallux rigidus, not to mention pain with prolonged activity and difficulty for women in wearing high heels. Accordingly, this author discusses conservative care and shares her insights on surgical treatment options.

Hallux rigidus involves a loss of motion and can potentially result in osteoarthritis of the first metatarsophalangeal joint (MPJ). It can be associated with a hallux valgus deformity so patients may have symptoms of both hallux valgus and hallux rigidus. Unlike hallux valgus, hallux rigidus is typically a dorsal bunion. It can result in a loss of cartilage, pain, stiffness, spur formation and an altered gait. Patients with osteoarthritis in the first MPJ often have osteoarthritis in other parts of their body.  

Symptoms of hallux rigidus typically involve pain and a loss of range of motion of the hallux. Most patients can tolerate the stiffness but will have difficulty with the pain during activity. Women often complain of difficulty wearing high heeled shoes. Active patients complain that they are unable to bend the toe back during a push-up or lunge. Activities that involve toe push off such as running, hiking and jump rope are difficult for these patients. Pain is worse with any prolonged activity. There is often enlargement and erythema of the first MPJ, which can limit shoe gear selection. A ganglion may develop over this area.

Patients often develop a callus under the interphalangeal joint and sometimes pain on top of the hallux nail or deformation of the nail as the hallux goes into extensus. Lack of motion at the first MPJ will cause compensation at the interphalangeal joint, most often resulting in hallux extensus.  

Common causes of hallux limitus include trauma, hypermobility of the first ray, neuromuscular imbalance, an elongated first metatarsal, an elevated first metatarsal or a flat metatarsal head. The etiology of hallux rigidus can be from muscle imbalance affecting the first ray or prolonged immobilization of the first MPJ. Patients can also have symptoms of hallux limitus yet have a normal range of motion during the exam. These patients demonstrate these symptoms during weightbearing and therefore have a condition called functional hallux limitus. Functional hallux limitus often develops into structural hallux limitus. For the purposes of this article, I will focus more on the structural and osteoarthritic components of hallux rigidus.

Pertinent Insights On Conservative Therapy
Conservative treatment of this problem includes topical and oral anti-inflammatories, rocker bottom shoes, modified orthotics and shoe modifications such as a metatarsal bar or stretching of the shoe to increase space in the toe box area.

Grady and colleagues conducted a retrospective analysis of 772 patients with symptomatic hallux limitus, 428 of whom (55 percent) received successful treatment with conservative care alone.¹ Of those 428 patients, 362 (84 percent) wore orthoses, 24 patients used corticosteroid injections and 24 patients had a change in shoes. The authors noted that overall, 47 percent of the patients had successful treatment with orthoses.

I have had a fair amount of success using a graphite plate or rigid extension of the orthotic under the first MPJ. I have also cut out the medial distal tip of the orthotic in an effort to lower the first ray in a patient with flexible first metatarsal elevatus. Advise patients to use stiffer shoes that prevent bending of the big toe joint. Cortisone injections can also provide temporary relief. There is some controversy as to whether range of motion and distraction exercises of the joint work. Increased motion at the joint can actually cause more pain if there is erosion of the articular cartilage or spur formation.

A Closer Look At Surgical Treatment Options

There are different surgical treatments for hallux rigidus.

The most common surgery is a cheilectomy, which involves resecting bone spurs and potentially removing the dorsal part of the joint to allow for improved dorsiflexion. In a study of 189 patients, Bussewitz and colleagues concluded that cheilectomy is an appropriate procedure for stages 1, 2, and 3 first MPJ degenerative joint disease and provides “reliable, lasting results.”²

Loose bodies are often present in the joint at the time of surgery. I will typically resect some bone off the dorsal part of the proximal phalanx as well to allow for improved range of motion. I remove as much as 35 percent of the dorsal joint. In areas where the articular cartilage has eroded to subchondral bone, it is accepted practice to microfracture or drill with a smooth K-wire to promote subchondral bleeding. The goal is to generate fibrocartilage in areas where the hyaline cartilage has worn away.  

I find it is important to resect enough bone especially in the dorsolateral joint if the patient has a component of hallux valgus in addition to hallux limitus. The hallux valgus causes impingement in the dorsolateral joint. I prefer to use a dorsomedial incision in these cases to resect the bone adequately. I have used straight medial incisions at the level of the joint but find it more difficult to access the lateral joint.

Some surgeons will opt for a decompression osteotomy of the first metatarsal and possibly a decompression osteotomy of the proximal phalanx. Although I may do a first metatarsal osteotomy to treat hallux rigidus associated with a hallux valgus, it is not my procedure of choice for a primary hallux rigidus unless the first ray is substantially elongated. When hallux rigidus is associated with a hallux valgus, I can realign the joint and possibly take a wedge of bone out of the first ray to decompress it. Shortening of the first ray may provide more joint space but complications such as metatarsalgia can occur.

There are many variations of osteotomies that can simply shorten and decompress, dorsiflex or plantarflex both the hallux articular cartilage or the proximal phalanx articular cartilage. One can combine decompression or a closing dorsal wedge phalangeal osteotomy with a cheilectomy to increase first MPJ dorsiflexion. Some common first metatarsal osteotomies are the Watermann and modified Green-Watermann osteotomies. Dickerson and coworkers performed a retrospective analysis of 40 patients to assess the long-term efficacy of the Green-Watermann procedure for the treatment of painful hallux limitus or rigidus.³ They concluded that the Green-Watermann procedure is effective treatment for hallux limitus and rigidus, leading to a significant reduction in pain, better function and patient satisfaction.

The Regnauld is a decompression osteotomy of the proximal phalanx that also preserves the joint. The Kessel-Bonney osteotomy procedure involves resection of a dorsally based section of bone from the base of the proximal phalanx.  

In elderly and less active patients, a Keller bunionectomy may be a good procedure as there is little postoperative disability. Resection of the base of the proximal phalanx of the hallux can also cause complications such as hallux instability, lack of toe purchase and push off, and metatarsalgia. In my practice, I have little use for this procedure as my patients are fairly young and active. When I do perform a Keller, I will pin the hallux for about three to four weeks postoperatively to encourage scarring in a rectus position. Cosmetically, the Keller bunionectomy will shorten the hallux.

There are different modifications of the Keller to help avoid some of these complications. Some surgeons will pin the joint postoperatively or perform tissue arthroplasty. Tissue interpositional arthroplasty involves placing a piece of capsule or tissue-free graft in the arthritic joint, similar to an “anchovy” procedure in the hand. With these cases, some retrograde pressure of the joint is necessary to maintain the graft so one should only resect minimal bone. These procedures have good short-term results in the foot.

Assessing The Use Of Implants

Implant procedures are another form of treatment for hallux osteoarthritis.The goals of the implant are to preserve range of motion and reduce pain. Patients with more advanced osteoarthritis of the joint who are not willing to have an arthrodesis may prefer to try an implant procedure first. There have been many iterations of implants including hemi- and total joints made from different materials including silicone and metal.

Implants can also have many different complications including metatarsalgia, breakage, loosening, osteolysis and foreign body reaction. I have removed more implants than I have put in. Implants seemed to be more common about 20 to 30 years ago and certainly were not well accepted during my residency years.

In older patients, I will sometimes offer an implant as an alternative to fusion. I prefer the resurfacing type of implant as there is little resection of bone off the first metatarsal head should the patient have to convert to an arthrodesis in the future. I allow patients to weight bear immediately in a controlled ankle motion (CAM) walker boot postoperatively. There are advantages with this implant with the preservation of joint motion and much easier patient tolerance of the postoperative course in comparison to the post-op recovery from a joint arthrodesis.

Why Joint Arthrodesis Is The Gold Standard For Osteoarthritis Of The First MPJ

Joint arthrodesis is the gold standard when treating osteoarthritis. This is also the salvage procedure I choose for a failed previous surgery, such as a failed procedure for a hallux varus. Patients who have associated neuromuscular conditions, resolved infections of the joint with post-infection arthritis, seronegative or rheumatoid arthritis, and hallux varus all may benefit from a joint arthrodesis. Active joint sepsis and hallux interphalangeal arthrosis are contraindications to first MPJ arthrodesis.

Most surgeons will fuse the joint in about 15 degrees of dorsiflexion and 15 degrees of valgus. I prefer to increase these angles slightly in women who may wear a heeled shoe. In the past, I used two crossed lag screws of the joint and kept the patient strictly non-weightbearing for six to eight weeks. With the newer low profile plates specifically designed for this joint, I have used dorsal plates with one or two compression screws across the joint and allowed patients to bear weight immediately in a CAM walker boot.  

This is my procedure of choice for end-stage osteoarthritis of the first MPJ although not every patient is open to the idea of having no motion at this joint after surgery. As with every surgery, fusion of this joint has complications. The most common complications include pain at the interphalangeal joint, malposition of the fused toe and stress fracture of the metatarsal shaft or proximal phalanx. Fixation complications and bone healing complications such as delayed unions or nonunions can occur. Migues and coworkers studied 101 joint arthrodesis procedures with an endomedullary screw fixation technique.⁴ Although the success rate was 93 percent, the authors did note five cases of asymptomatic nonunion, five cases with poor results because of symptomatic nonunion and screw removal in four feet.

There will also be shortening of the hallux after an arthrodesis, especially if it is a salvage procedure in a patient who has had a previous surgery. In patients with previous surgical histories, I often use bone allograft to augment the arthrodesis surgery. The bone allograft provides adequate length to maintain hallux length. I have not encountered many problems with bone healing when using allograft in comparison with autograft. I prefer using allograft in order to avoid donor site complications and morbidity.

In Conclusion

The two most common procedures I do for hallux rigidus are cheilectomy and arthrodesis. Those surgeries have well documented success rates and have predictable outcomes for most surgeons.^2,4 With the advent of newer implants on the market, the success rates and predictability of these procedures may increase and generate more popularity among surgeons. Longer-term follow-up studies are needed before implants will be in wider use.

Dr. Cheung is in private practice in San Francisco. She is a Fellow of the American College of Foot and Ankle Surgeons, and is board certified in foot surgery and reconstructive ankle surgery.

References
1.    Grady JF, Axe TM, Zager EJ, Sheldon LA. A retrospective analysis of 272 patients with hallux limitus. J Am Podiatr Med Assoc. 2002; 92(2):102-8.  
2.    Bussewitz BW, Byment MM, Hyer CF. Immediate-term results following first metatarsal cheilectomy. Foot Ankle Spec. 2013; 6(3):191-5.
3.    Dickerson JB, Green R, Green DR. Long-term follow-up of the Green-Watermann osteotomy for hallux limitus. J Am Podiatr Med Assoc. 2002; 92(10):543-54.
4.     Migues A, Calvi J, Sotelano P. Endomedullary screw fixation for first metatarsophalangeal arthrodesis. Foot Ankle Int. 2013; 34(8):1152-7.

For further reading, see “How To Treat Osteoarthritis Of The First MTPJ” in the March 2004 issue of Podiatry Today.

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