CHAPTER 1 Addressing Hallux Valgus in the Metatarsus Adductus Foot Type William D. Fishco, DPM INTRODUCTION there is not much of an increased intermetatarsal angle due to the varus deformity of the lesser metatarsals. Metatarsus adductus is a congenital foot deformity When a patient presents to the offi ce with a chief complaint characterized by a uniplanar deformity where the metatarsals of a bunion, and after the work-up there is signifi cant are angulated at the Lisfranc’s joint causing adduction of the metatarsus adductus, surgery options really have be carefully forefoot in relation to the midfoot and hindfoot (1). The implemented. Unless there is severe dysfunction of the foot, occurrence of metatarsus adductus has been reported to be pan metatarsal osteotomies are not typically recommended. 1 to 2 cases per 1,000 (2,3). Metatarsus adductus is the most However, your typical “go to” bunionectomy may not be the common congenital foot deformity in the newborn (3) with best option. For example, if you typically perform an Austin a male predilection as high as 80% (2). Fetal constraint is the bunionectomy or equivalent (distal metaphyseal osteotomy), most common cited etiologic factor with compression of it will likely yield a poor outcome with failure to correct the the forefoot with the legs crossed across the body (2). deformity and/or rapid recurrence of deformity. Decision- Obvious congenital deformities such as calcaneovalgus making and procedural selection becomes more intense. and talipes equinovarus (clubfoot) are quickly identifi ed Expectations of the surgery need to be clearly communicated at birth and treated appropriately. Since there are no to your patient as the typical result of “bump gone toe standard foot screening methods or protocols of newborns straight” is not likely achievable. for minor deformities such has metatarsus adductus, these We are familiar with evaluating the intermetatarsal go untreated and will surface as problems later in life. As angle on an anteroposterior radiographic view. If you, in clinicians, we see metatarsus adductus in older children and part determine your procedure based on that criterion, adults on a regular basis, confi rming the lack of recognition then remember to calculate the true intermetatarsal angle, at infancy. which is the intermetatarsal angle plus (metatarsus adductus The metatarsus adductus foot type is associated with a angle minus 15 degrees). For example, if the intermetatarsal number of clinical challenges for the podiatrist. Some of the angle measures 8 degrees and the metatarsus adductus angle common pathologies include Jones fractures, pain due to measures 25 degrees, then the true intermetatarsal angle is the prominence of the fi fth metatarsal base, premature non- 18 degrees, 8+(25-15)=18. An Austin bunionectomy may be traumatic arthrosis of the second and third tarsometatarsal appropriate for an 8-degree intermetatarsal angle; however, joints, lateral column foot pain, and severe bunion a bunion deformity with an 18 degree intermetatarsal angle deformities. When metatarsus adductus is seen in the high will typically need another type of correction. arched foot, pathologies worsen and treatment is even more The following list will include some pearls to remember demanding and challenging. These feet are associated with when addressing large bunion deformities with underlying lateral ankle instability, chronic peroneal tendinopathies, metatarsus adductus deformity: dorsal tarsal metatarsal joint exostoses with or without • Set realistic expectations. Always discuss the two peroneal nerve irritation, and chronic dorsolateral foot deformities that you are treating or dealing with, pain (lateral column overload) (4). Often, just fi xing a metatarsus adductus and hallux valgus. Explain to ligament or tendon may not address the global problem your patient that you are limited to the amount of the pes cavus deformity. To that end, in addition of “straightening” of the fi rst metatarsal bone by to addressing the ligament or tendon, a cavus foot the patient’s anatomy. Even though pain should reconstruction may be prudent. resolve and the foot will clinically look better, there will still be a residual bunion and the toe will not SURGICAL MANAGEMENT be straight. I typically show them that all of their toes deviate laterally due to the medial drift of the The surgical management of hallux valgus in the metatarsus metatarsal bones. Remember the toes move in the adductus foot type is one of the most challenging surgical opposite direction of the metatarsals. scenarios that we have to deal with. Clinically, the bunion • Avoid distal metatarsal osteotomies. I am always deformity always looks worse than the radiograph. Often, more aggressive in correction by doing a base 2 CHAPTER 1 wedge osteotomy or a Lapidus. This is the case advanced long-standing deformity, remember to in juvenile hallux valgus and with underlying consider a fi rst MTPJ fusion. metatarsus adductus. You will sometimes need to • Pick your battles. Let’s face it, we are surgeons and slightly overcorrect your bunion correction. You are we fi x things. There is nothing wrong with being less likely to get a varus deformity in the metatarsus honest with your patient telling them that unless foot type with a slightly negative intermetatarsal they can’t live with it…they should just live with it. angle than in the rectus foot type. As you know, most patients think a bunionectomy is • Consider an Akin. It is diffi cult to get a straight toe a simple procedure where you shave the bump and after the metatarsal work is done. Clinically it helps call it a day. After a thorough review of what would with appearance. need to be done to fi x the problem appropriately, • Consider a second and third metatarsal osteotomy the best answer may be wearing wider shoes and if the deformity is mostly of the medial three using pads/cushions. If you are both up to the metatarsals, which is quite common. After the challenge and investment of time and energy, second and third metatarsals have been shifted then fi ne, do the surgery. Otherwise, there is no laterally, now you have more room to get the fi rst harm in treating it conservatively. I tell my patients metatarsal over. You can then do a Lapidus, Scarf, “Bunions won’t kill you, they just make you suffer or base-wedge osteotomy. a little.” • Consider a fi rst metatarsophalangeal joint (MTPJ) fusion when there is an element of degenerative CASE REPORTS joint disease or if you are considering a pan metatarsal head resection in a severe case of laterally The fi rst case is in a 14-year-old girl, who was active with windswept toes. You can be assured that when the cheerleading and volleyball. She presented with the chief fusion is done, the toe is not going to laterally drift complaint of a painful bunion deformity. Evaluation of her and you will not loose correction. A fi rst MTPJ anteroposterior radiograph revealed moderate metatarsus fusion should always be on your radar screen for adductus with a bunion deformity (Figure 1). I knew an a “jumbo” bunion deformity. We have all seen Austin would not hold up in the long run. I chose to do recurrence of a bunion with a Lapidus due to a closing base-wedge osteotomy. When you look at the splaying at the intercuneiform joint, however, you postoperative radiograph, you will notice a slight over will be hard pressed to fi nd a recurrence of a bunion correction of the intermetatarsal angle (Figure 2). In order after a fi rst MTPJ fusion. In the older patient with to get a congruous joint, you will need to do that at times. Figure 1. A 14-year-old female with moderate Figure 2. View of a closing base wedge osteotomy of bunion deformity with underlying metatarsus the fi rst metatarsal. Note the slight over-correction adductus. of the intermetatarsal angle. CHAPTER 1 3 Figure 3. View of a 24-year-old Figure 4. Postoperative view female with metatarsus adductus after a Lapidus bunionectomy. and bunion deformity. Note the slight negative intermetatarsal ankle. Figure 5. Radiographic view of Figure 6. View after second and a 62-year-old female with severe third metatarsal osteotomies with a metatarsus adductus deformity. Lapidus bunionectomy. A 24-year-old female presented to the offi ce wanting her 4). By doing this, I was able to get a congruous joint, which bunion fi xed. Her pain was on the “bump” and she had trouble should give long-lasting correction. wearing dress shoes, which were necessary for her work. A 56-year-old female presented to the offi ce with severe Radiographs revealed a metatarsus adductus with a moderate deformity of her left foot. She was having trouble wearing bunion deformity (Figure 3). Again, this is a case where an conventional shoes and was wearing mostly slipper type Austin bunionectomy is not going to give you the correction shoes. She stood all day sorting mail in a US postal service that you need. I chose to do a Lapidus bunionectomy. Notice mailroom. Radiographs revealed severe metatarsus adductus the slight over-correction of the intermetatarsal angle (Figure deformity with mid-foot arthrosis (Figure 5). This is one of 4 CHAPTER 1 Figure 7. Radiograph of a 74-year-old Figure 8. Radiograph after a male with long-standing deformity. second and third metatarsal osteotomy with arthrodesis of the fi rst metatarsophalangeal joint. Note the improved position of the second and third toes. Figure 9. Preoperative radiographs Figure 10. Postoperative radiograph. of a 40-year-old female with a large hallux valgus deformity with metatarsus adductus affecting mostly the medial 3 metatarsals. those very challenging cases where one has to consider a not have any midfoot pain where she had arthrosis of the major reconstruction.