Subungual exostosis of the toes: a systematic review

Abstract

Background: Subungual exostosis is a relatively common benign bone tumor that occurs in the distal phalanges of the toes and can be a source of pain and nail deformity. There is controversy about the treatment of these lesions and there are few studies that have synthesized what is known and provided meaningful information on treatment.

Questions/purposes: We performed a systematic review to address the following questions: (1) What is the best surgical approach for excising these lesions? (2) What is the age range, sex distribution, and presenting symptoms of subungual exostoses and which toe is most frequently affected? (3) What complications arise from treatment?

Methods: Two authors independently searched multiple databases (Medline, 1950-May 2013; Cochrane EBM database, and EMBASE, 1980-May 2013 provided by OVID; ACP Journal Club, 2003-May 2013; CINAHL by EBSCO, 1937-May 2013; and PubMed by NLM, 1940-May 2013), and key words were chosen to achieve a broad search strategy. We included studies on the management of toe exostoses with > 10 cases and we excluded studies that reported on upper extremity exostoses or osteochondromas. Demographic and treatment data were collected from each article by two independent authors and collated. A total of 124 abstracts were screened, and 116 articles were reviewed in full, of which 13 met the inclusion criteria.

Results: Complete marginal excision through a fish mouth incision protecting the nail led to a recurrence rate of 4% and satisfactory clinical results, defined as no requirement for postoperative intervention and a satisfactory clinical appearance in 73%. Most studies provided incomplete descriptions of specific surgical techniques used. Fifty-five percent of the patients were younger than 18 years of age. A history of toe trauma before diagnosis was present in approximately 30% of the cases. Delayed diagnosis occurred in approximately 10% of the cases and onychodystrophy occurred in more than 10%.

Conclusions: There is weak evidence to guide management of subungual exostosis. Adequate wound management postexcision aiming to minimize disruption to the nail bed and matrix may prevent onychodystrophy, which is a common complication of treatment.

Fig. 1A–D

Clinical photographs and radiographs of the same subungual exostosis in the right hallux of a 15-year-old girl presenting with pain and an enlarging mass for 3 months. (A) Dorsal and (B) medial clinical photographs and (C) posterior-anterior and (D) lateral radiographs of the same lesion. Reproduced with permission from BMJ Case Reports [6].

Fig. 2

Light microscopic image of a histological specimen taken intraoperatively from the great toe of a 15-year-old girl. It shows dermal tissue with normal trabecular bone and fibrocartilaginous overgrowth, consistent with subungual exostosis. Reproduced with permission from BMJ Case Reports [6].

Fig. 3

Flow diagram used to include and exclude relevant articles for the review. Criteria were based on PRISMA guidelines. One hundred twenty-four studies were initially identified through the database screening with 13 meeting all inclusion/exclusion criteria.

Fig. 4

Pattern of distribution in subungual exostosis of the foot. Total number and percentage from each digit are included.

Fig. 5A–B

Intraoperative images of a marginal excision of subungual exostosis of the great toe in a 15-year-old girl. (A) The lesion invaded the nail bed, which was not salvageable; thus, a direct dorsal exostectomy was performed. (B) The osteocartilaginous lesion was marginally resected and the base of the stalk was curetted, ronguered, and burred down creating a “saucer-like defect.” The sample was sent for pathological analysis and found to be consistent with subungual exostosis. Reproduced with permission from BMJ Case Reports [6].