Current Management of Lesser Toe Deformities, An Issue of Foot and Ankle Clinics , livre ebook

Current Management of Lesser Toe Disorders , Vol. 16, No. 4, December 2011
ISSN: 1083-7515
doi: 10.1016/S1083-7515(11)00086-6

Contributors
Foot and Ankle Clinics
Current Management of Lesser Toe Disorders
GUEST EDITOR: John T. Campbell, MD
CONSULTING EDITOR: Mark S. Myerson, MD
Institute for Foot and Ankle Reconstruction at Mercy, Mercy Medical Center, 301 St Paul Place, Baltimore, MD 21202, USA
ISSN  1083-7515
Volume 16 • Number 4 • December 2011

Current Management of Lesser Toe Disorders , Vol. 16, No. 4, December 2011
ISSN: 1083-7515
doi: 10.1016/S1083-7515(11)00093-3

Contents
Cover
Contributors
Forthcoming Issues
The Lesser Toes
Mallet Toe Deformity
Hammertoes and Clawtoes: Proximal Interphalangeal Joint Correction
Hammertoes/Clawtoes: Metatarsophalangeal Joint Correction
The Use of Flexor to Extensor Transfers for the Correction of the Flexible Hammer Toe Deformity
Metatarsalgia: Distal Metatarsal Osteotomies
Metatarsalgia: Proximal Metatarsal Osteotomies
The Crossover Toe and Valgus Toe Deformity
Revision Surgery of the Lesser Toes
Freiberg's Disease
Congenital Lesser Toe Abnormalities
Bunionette Deformity: Etiology, Nonsurgical Management, and Lateral Exostectomy
Osteotomies for Bunionette Deformity
Index
Current Management of Lesser Toe Disorders , Vol. 16, No. 4, December 2011
ISSN: 1083-7515
doi: 10.1016/S1083-7515(11)00087-8

Forthcoming Issues
Current Management of Lesser Toe Disorders , Vol. 16, No. 4, December 2011
ISSN: 1083-7515
doi: 10.1016/j.fcl.2011.09.003

Preface
The Lesser Toes

John T. Campbell, MD
jcampbell@mdmercy.com ,
Institute for Foot and Ankle Reconstruction at Mercy, Mercy Medical Center, 301 St Paul Place, Baltimore, MD 21202, USA

John T. Campbell, MD, Guest Editor
The lesser toes contribute to normal function of the forefoot and to propulsive gait. Disorders of these toes can be difficult for the patient and surgeon alike. Patients suffer pain, dysfunction, and difficulty with footwear, all hallmarks of lesser toe pathology. Surgeons also find these problems troubling, with seemingly simple surgeries complicated by recurrent pain, deformity, and patient dissatisfaction. This issue of Foot and Ankle Clinics explores various conditions, considering etiology, evaluation, nonoperative treatment, and surgical options for the lesser toes. A panel of international authors provides outcomes-based recommendations along with personal experience and practical tips to assist the reader in treating these difficult problems.
A series of authors discuss deformities of the lesser toes, including mallet, hammer, claw, and crossover toes. These articles discuss the relevant anatomy and pathophysiology of each condition followed by appropriate evaluation and treatment algorithms. Surgical topics include joint-sparing and fusion techniques, tendon transfers, and metatarsal osteotomies. The treatment of metatarsalgia is also reviewed, considering both distal and proximal metatarsal osteotomies. Common disorders, such as Freiberg's infraction and the bunionette deformity, are also covered in depth.
Congenital lesser toe problems are uncommon, leading to a paucity of literature and relative inexperience among many surgeons. The contributing authors lead the reader through clinical evaluation and treatment options to properly manage these unusual but troubling conditions while minimizing complications. Failed lesser toe surgeries are also covered, guiding the reader through an experienced approach to this frustrating yet little-discussed problem.
A diverse group of experts have contributed to this issue, which is designed to assist surgeons in the treatment of these problems. We hope that our efforts will assist in the treatment of patients, leading ultimately to diminished pain, improved function, and fewer complications.
Current Management of Lesser Toe Disorders , Vol. 16, No. 4, December 2011
ISSN: 1083-7515
doi: 10.1016/j.fcl.2011.08.004

Mallet Toe Deformity

Andrew Molloy, FRCS Tr&Orth a , * orthoblue@aol.com , Raheel Shariff, MRCS b
a Aintree University Hospitals NHS Foundation Trust, University Hospital Aintree, Liverpool, Merseyside, Longmoor Lane, Liverpool, L9 7AL, UK
b Trauma and Orthopaedic Surgery, Mersey Deanery Rotation, St Helens and Knowsley Teaching Hospitals NHS Trust, Prescot, Merseyside, UK
* Corresponding author

Keywords
• Mallet • Toe • Lesser • Deformity • Interphalangeal • Joint
Mallet toe is defined as flexion of the distal phalanx over the middle phalanx due to a contracture at the distal interphalangeal joint (DIPJ) ( Fig. 1 ). 1 – 4 The term was first coined by Lake 5 in the orthopedic literature. A mallet toe apart from a sagittal plane deformity described here may also have medial or lateral deviation of the distal phalanx. There is confusion in the orthopedic literature over the definition of the lesser toe deformities, particularly the common ones of hammer toe, clawtoe, and mallet toe. 6 This confusion was shown in a study among Dutch orthopedic surgeons in which there was a lack of consensus in definition and treatment strategies. Although lesser toe surgery is commonly performed, level I evidence and prospective studies are lacking to help determine which procedure is the most successful in achieving good clinical results. 7 The authors offer a practical approach to the diagnosis and treatment of mallet toes for the practicing surgeon.

Fig. 1 Mallet third and fourth toes.

Anatomy
The understanding of the extrinsic and intrinsic muscles of the lesser toes and their relationship to the phalanges is crucial for understanding the deformities in this region. The second to fifth toes have three phalanges, whereas the hallux has two. The distal phalanx is the broadest and shortest of the three phalanges and triangular in shape. 8 It supports the germinal and sterile matrices of the overlying nail. 9 It has an oval base for articulation with the trochlear-shaped middle phalangeal head. The base also has tubercles on each side for the insertion of the collateral ligaments. Its tip is described as cauliflower-shaped with a bilobed appearance, which increases the surface area of the tip for weight bearing during the push-off phase of the stance cycle. The distal phalanx has two ossification centers—a primary center in the shaft appearing by the 12th week and a secondary center at the base (epiphysis) arising by the sixth year. 8, 10 These two centers fuse by the 18th year.
The DIPJ is a ginglymus, or a hinge joint. Its normal range of movement is 10° dorsiflexion and 40° plantarflexion. 11 The distal phalanx is controlled by the action of the flexor and extensor tendons, which insert into it (extrinsics) and to a certain extent indirectly by the interossei and lumbricals through their attachment to the extensor hood ( Fig. 2 ). 1

Fig. 2 Muscle actions across the toe and flexor tendon anatomy.
The extensor apparatus to the lesser toes has been well described by Sarrafian and colleagues. 12, 13 It consists of the extensor digitorum longus tendon, which divides into three slips at the level of proximal phalanx. The middle slip inserts into the base of the middle phalanx and the two other slips (dorsomedial and dorsolateral) converge and attach at the base of the distal phalanx and act as its principal extensor. The dorsomedial slip is joined by the lumbrical, and the dorsolateral slip is joined by extensor brevis tendon, except for the little toe, which usually does not have a slip from the extensor brevis tendon. 9 . The tendon is encased in a fibroaponeurotic sling at the level of the metatarsophalangeal joint and extending to the proximal interphalangeal joint level. This “extensor sling” helps keep the tendon in a central position. The tendon is not attached to the proximal phalanx dorsally but via the sling attaches to its plantar surface, thereby acting to dorsiflex the proximal phalanx. It acts to extend the proximal interphalangeal joint only when the proximal phalanx is flexed or in a neutral position. However, when the proximal phalanx is extended, the extensor action of the long extensor tendon is negated on the proximal interphalangeal joint. 4 The “extensor wing,” which forms the distal portion of the dorsal extensor complex is a triangular hood that is found on either side of the toe. It has oblique fibers, dorsally being attached to the extensor digitorum longus tendon and its proximal border merging into the extensor sling. The lumbricals form the oblique border of this hood. 12
The antagonist of the extensor pull on the distal phalanx is by the action of the flexor digitorum longus, the principal extrinsic flexor to the DIPJ. This muscle passes through a tunnel created by two slips of the flexor digitorum brevis at the proximal interphalangeal joint level before inserting into the base of the distal phalanx. The flexor digitorum brevis inserts into the base of the middle phalanx. These two muscles flex the distal and proximal interphalangeal joints, respectively. The flexor tendon is a distinct structure at the level of the distal phalangeal joint. 14
Apart from the extrinsics, the distal phalanx is also indirectly controlled at the DIPJ by the action of the weaker intrinsic muscles—the lumbricals and the interossei. The interosseous tendons are located dorsal to the transverse metatarsal ligament, and the lumbricals are plantar to it. With respect to the axis of metatarsophalangeal joint motion, both these tendons are plantarward