Pincer Nails: Definition and Surgical Treatment

BACKGROUND: There are four main types of ingrown nail. These are distal nail embedding, juvenile (subcutaneous) ingrown nail, hypertrophy of the lateral nail fold (lip), and pincer nail. OBJECTIVE: The etiology of pincer nail may be hereditary or acquired. The mechanism of the most common form, an enlarged base of the distal bony phalanx, is discussed. METHODS: Use of roentgenogram and magnetic resonance imaging highlights exophytes of the base and dorsal hyperostosis of the distal phalanx. RESULTS: Global assessment may lead in mild cases to medical therapy. Usually, however, the lateral matrix horn must be surgically removed or cauterized by phenol. Dermal grafting under the nail matrix provides excellent long-term results.     

Giant cell tumor of distal phalanx of great toe. A case report

Giant cell tumors are locally aggressive benign osseous neoplasms of unknown origin. They mostly occur after skeletal maturity in 3rd or 4th decade and commonly involve long bones although occasional occurrence at other sites has been reported. It is rare to see these tumors involving the phalangeal bone of foot. We report a case of giant cell tumor involving the distal phalanx of great toe in a 27 year old female who presented with swelling of great toe of right foot. Radiography showed an expansile lesion in distal phalanx of great toe. En bloc resection of phalanx was done. Biopsy showed giant cell tumor and regular follow up of this patient for two years showed no recurrence of tumor. Giant cell tumor at such a location is unusually aggressive and needs regular follow up to detect local recurrence.     

Correction of crooked nail deformity by modified osteoplastic reconstruction

To correct crooked nail deformity, which results from the partial loss of the distal phalanx, soft-tissue restoration alone is usually not enough to restore the length and shape of the nail structure. The authors treated 10 crooked nail fingertips by modified osteoplastic reconstruction, which included the elevation of the dorsally based volar skin flap and an iliac bone graft covered by an adequate skin flap. During the postoperative follow-up, the nail straightened, although not to the preinjury extent, along the restored distal phalanx with bony support. The authors' osteoplastic reconstruction, which involves the enhancement of the fingertips with composite tissues, presents a practical method for the correction of crooked nail deformity.     

Two families with congenital nail anomalies: Nail formation in ectopic areas

Two families with congenital nail anomalies are reported. The nail covered not only the dorsal but also some of the palmar aspect of the distal phalanx. The ungual phalanges of the affected fingers were lacking in the crescent-shaped cap and had a blunt Y-shaped bony projection. The anomalies may have been transmitted by an autosomal recessive gene.     

Imaging of tumors of the nail unit

In case of suspicion of a deep mass beneath the nail plate, radiographs remain necessary to assess the distal phalanx and the distal interphalangeal joint. Ultrasonography may be helpful to depict a cystic or a vascular component of a tumor. Computed tomography is only indicated to accurately assess tiny abnormalities of the cortex of the distal phalanx. MR imaging offers a whole imaging of the soft parts of the nail unit and the underlying bone.     

A simple and efficient surgical technique for subungual exostosis

Subungual exostosis is a benign osteochondral tumor usually involving the distal phalanx of the great toe. The lesion most frequently occurs in the second and third decades of life and is rare before the age of 10 years. There are few reports of its occurrence in children, and most of them advocate partial or complete nail excision to treat this lesion successfully. We report our experience with six children and adolescents using a simple surgical technique that involves approaching the exostosis under the nail to preserve nail coverage. Rapid recovery and excellent cosmetic appearance were achieved immediately after the operation.     

趾端骨软组织矫形术在顽固性嵌甲中的应用

目的探讨趾端骨、软组织矫形术治疗顽固性嵌甲的临床效果。方法1997年10月-2006年5月，收治顽固性晦趾嵌甲患者31例38趾，采用白行设计的趾端骨、软组织矫形术治疗。男23例27趾，女8例11趾。年龄12～28岁，平均17．5岁。病程2年1个月～14年，平均31．6个月。均经5～9次拔甲治疗。合并甲沟炎急性期14例18趾，甲沟炎慢性期17例20趾。选取同期收治足部疾病但晦趾完整38例患者作对照。测量患者甲沟深度及摄X线片，测量爪粗隆上翘比例r值。结果患者甲沟深度及r值分别为2．87±0．31mm及0．149±0、013，与对照组1、06±0.10mm及0．060±k0．019比较，差异均有统计学意义（P〈0．01）。术后30例37趾伤口I期愈合，1例1趾伤口延迟愈合。29例36趾获随访8～29个月，平均21个月。趾端外形良好，无复发或再次手术。结论（足母）趾末节趾骨爪粗隆上翘、甲沟肥大变深是（足母）嵌甲重要的解剖学病因，采用趾端骨软组织矫形术是根治顽固性嵌甲的一种有效手术方法。     

Curvatures of the DIP joints of the hand

Background

The distal interphalangeal (DIP) joints of the hand are highly susceptible to osteoarthritis and trauma. Surgical treatment options mandate accurate characterization of their osseous anatomy; however, there are few studies that describe this. We describe the curvatures of the DIP joints by measuring the bone morphology using advanced imaging and modeling methods.

Methods

The fingers of 16 right hand fresh frozen human cadavers were analyzed. Fingers showing signs of DIP joint arthritis were excluded. The fingers were scanned using microtomography (microCT). Measurements of the bony morphology were made using models created from the scans.

Results

In each finger, there is no statistically significant difference between the radii of curvature of the ulnar and radial condyles of the middle phalanx head. Conversely, the radius of curvature of the distal phalanx ulnar groove is significantly greater than that of the radial groove. The radii of curvature of the groove of the distal phalanx and the condyles of the middle phalanx displayed nonconformity with disparity increasing from the index to small fingers. Remarkably, the radius of curvature of the distal phalanx central ridge and the mean radius of the middle phalanx condyles are essentially the same.

Conclusion

The purpose of this study is to gain better insight into the DIP joints of the hand. The asymmetry between the distal phalanx grooves and the middle phalanx condyles suggests that there may be a translational component to DIP joint motion. Our understanding of morphology may lend insight into the biomechanics and disease progression within the DIP joints.     

Metastatic Tumors to the Nail Unit: Subungual Metastases

BACKGROUND: Cutaneous metastases are variable in location and morphology. Metastatic tumor can present as a subungual lesion in either an oncology patient or a previously cancer-free individual. However, the diagnosis of a subungual metastasis is often not initially considered since the symptoms and appearance of the subungual tumor frequently mimic those of other conditions. OBJECTIVE: To describe the clinical characteristics, radiographic changes, and pathologic findings of the subungual metastases in two women with metastatic carcinoma and to discuss the features of metastatic tumor lesions to the subungual area and distal digits previously reported in oncology patients. METHODS: The clinical presentation, radiologic studies, and pathologic examination of metastatic subungual tumor lesions were described in two oncology patients: a woman with breast cancer and a woman with renal cell carcinoma. The published reports of cancer patients with subungual metastases were reviewed and the following variables were evaluated: the primary origin of the cancer, the histology of the primary tumor, the temporal relationship between the onset of symptoms or the appearance of subungual metastasis and the diagnosis of the visceral malignancy, the symptoms and the morphology of the subungual metastases, the clinical differential diagnosis of subungual metastases, the relationship between the site of origin of the primary tumor and the incidence of metastases either to the fingers and the thumbs or to the toes, the distribution of subungual metastases, the incidence of radiologically confirmable bony involvement of the distal phalanx by metastatic tumor in the digit containing the subungual metastasis, and the prognosis of patients in whom the diagnosis of a subungual metastasis has been confirmed. RESULTS: Subungual metastases most frequently occur in patients with primary tumors of the lung (41%), genitourinary tract organs (17%, of which the kidney represents 11%), and breast (9%). The histology of the primary tumors that was most common included renal cell carcinoma and squamous cell carcinoma. The appearance of the subungual tumor was the first sign of a previously unsuspected primary malignancy in 44% of the patients with subungual metastases. Subungual metastases were frequently painful and most often presented as either an erythematous enlargement or swelling of the distal digit or a red to violacious nodule that distorted either the nail plate or the soft tissue of the distal digit, or both. The lesion was often initially mistaken as an acute infection. The lesion involved one or more digits of the hands in 92% of patients with subungual metastases; symmetrical subungual metastases and metastatic tumor restricted only to the great toes were less commonly observed. In patients with subungual metastases that involved the digits of their hands, the most frequent sites of primary tumor origin were the lung (35%) and the genitourinary tract organs (25%). Radiologic evidence of bony involvement of the respective distal digit was either initially present or subsequently developed in 92% of patients with subungual metastases. Patients with subungual metastases have a poor prognosis; their survival following the diagnosis of the subungual tumor is usually only a few months. CONCLUSION: The clinical differential diagnosis of a new periungual or subungual lesion (with or without an associated nail plate dystrophy) should include tumor metastasis to the nail unit not only in oncology patients, but also in previously cancer-free individuals.     

The hallucal distal phalanx and transverse convexity of the nail plate: the relationship

It has been suggested that the distal phalanx is responsible for determining the shape of the nail plate. A pilot study (n =10) was undertaken to analyse the cross-sectional profile of the hallux and identify possible relationship between the distal phalanx and nail plate. The study involved 5 halluces presenting with nails of normal transverse convexity and 5 with overcurvature, taken from 10 cadavers. Transverse cross-sections were analysed at 5 points through each distal phalanx using magnified photographs (×4) and a mathematical formula as a measurement tool. Results suggest that the phalanx plays less of a role in determining nail plate convexity than was previously thought, with high variation between the cross-sections within one digit, and from one digit to the next. This suggests that transverse convexity of the nail plate appears not to be determined simply by the convexity of the underlying phalanx, but rather by other changes stemming from within the individual matrix, subungual dermis or surrounding anatomical structures.     

Squamous cell carcinoma of the nail bed.

Twenty-seven cases of squamous cell carcinoma of the nail bed seen by the author have been reviewed. Sixteen were thought to be primary tumors and eleven to be secondary to chronic exposure to radiation. All had been present for a long time prior to definitive treatment. The tumor was of low grade malignancy with a tendency to invade the distal phalanx. No metastases have been found. Treatment was amputation of the distal phalanx and involved tissues.     

Endometrial Carcinoma Metastasis to the Distal Phalanx of the Hallux: A Case Report

Endometrial carcinoma is the most common invasive cancer of the female genital tract and accounts for 7% of all invasive cancer in women. Bony metastasis is uncommon with endometrial carcinoma and distal metastasis is very rare. The purpose of this paper is to present a case of an 86 year-old female with endometrial carcinoma metastasis to the distal phalanx of the hallux. The patient had a known history of endometrial carcinoma with metastases (FIGO IIIC), and had been diagnosed with pulmonary and bony metastases 2 months prior to presentation. Her initial foot complaint was of a painful, infected ingrown toenail. The infection continued to progress following avulsion of the nail, and the patient was then diagnosed with osteomyelitis. Given her past history, the possibility of metastasis to the hallux was also considered. A hallux amputation was performed, and the pathology report revealed the diagnosis of endometrial carcinoma metastasis to the distal phalanx of the hallux. While the amputation site healed uneventfully, the patient refused further treatment measures for her carcinoma and eventually succumbed to the disease.     

Examination of the anatomic relationship of the proximal germinal nail matrix to the extensor tendon insertion

The purpose of this study was to delineate the relationship of the terminal extensor tendon insertion to the proximal limit of the germinal nail matrix. Sixteen fresh-frozen human cadaver fingers without any evidence of trauma (average age, 55 years; 3 males and 1 female) were used for this study. Under x25 magnification the proximal limit of the germinal nail matrix and the terminal bony insertion of the extensor tendon were identified. The distance from the terminal tendon insertion to the germinal nail matrix was ascertained using precision calipers. The average distance from the terminal extensor tendon insertion to the proximal edge of the germinal nail matrix was found to be 1.2 mm. We conclude that the proximal limit of the germinal matrix is extremely close to the terminal extensor tendon bony insertion. When the extensor tendon insertion is visualized during operative exposures of the dorsum of the distal phalanx, care should be taken to avoid damaging the germinal matrix. Conversely, when the nail bed is being completely excised, visualization of the insertion of the extensor tendon will indicate that further proximal dissection is not required.     

Subungual glomus tumors of the fingers: ultrasound diagnosis

INTRODUCTION: Glomus tumors of the fingers are rare, benign tumors. These lesions are hamartomas, originating from dermoepidermic glomus, most commonly located at the distal phalanx, and in particular under the nail. Diagnosis is often delayed because of the absence of specific symptoms. Confirmation can only be made by histological study. The aim of this retrospective study is to define the role of ultrasound examination in the diagnosis of glomus tumors of the fingers. METHOD: During the period March 2002-March 2004, 12 cases of subungueal glomus tumors were included in this retrospective study. All patients underwent ultrasound and Doppler examinations before surgery. All Ultrasound Doppler studies were performed by the same radiologist. The mean age of patients was 44 year-old and the sex-ratio was 1/2. RESULTS: Pain was noted as a symptom in all patients. The mean size of the tumor was 3.5 mm. In eleven patients, ultrasound study was able to confirm the diagnosis, but it failed in one case because of the small size of the tumor (less than 2 mm). Ten tumors presented a Doppler hypersignal, located in the tumor and compatible with the diagnosis of glomus tumor. DISCUSSION: Diagnosis of glomus tumor is based on clinical examination, standard radiology, and ultrasound Doppler study. Ultrasound examination and Doppler study gives better visualization of tumors compared to standard radiology. These studies are useful for follow-up of patients in the post-operative period.     

Enchondroma: a case report and literature review

An unusual case of enchondroma located in the distal phalanx of the left third toe is presented with a review of literature. An enchondroma is a benign tumor centrally located in a bone. This osseous dysplasia is characterized by an excess of mature hypertrophic hyaline cartilage that has not resorbed or ossified in the normal fashion. Pathologic, clinical, and radiographic findings will be discussed.     

Congenital onychodysplasia of the index fingers

Twenty-two fingers of 13 patients had dysplastic nails. Four types of congenital onychodysplasia of the index fingers such as anonychia, rudimentary, split rudimentary (polyonychia), and micronychia were found in five, three, eight, and six fingers, respectively. Narrowing at the distal end of the affected distal phalanx (lack of the cresent-shaped cap), and a Y-shaped bony projection were characteristic features seen on x-ray films. There were no associated ectodermal abnormalities. Syndactyly was a relatively common associated hand anomaly. Some cases of congenital onychodysplasia of the index fingers were inherited. These findings suggest that impediments to the membranous ossification center can lead to a dysplastic crescent-shaped cap with nail anomalies.     

手指血管球瘤26例临床分析

目的　探讨手指血管球瘤的诊断和手术方法。方法　 1996年 1月 -2 0 0 2年 12月 ,对 2 6例手指血管球瘤进行诊治。术前 2 6例Love氏试验阳性 ,冷敏感试验阳性 ,2 0例Hildreth氏试验阳性 ,15例中 11例透光试验阳性 ,1例X线侧位片显示末节指骨有肿瘤压迹。全部病例均采取肿瘤切除手术。结果　术后随访 11个月～ 7年 9个月 ,无 1例肿瘤复发。 2 6例疼痛完全消失 ,术前阳性症状全部消失。 2 2例指甲生长良好 ,无明显畸形。结论　提高对血管球瘤的认识 ,有助于早期诊断 ,早期治疗 ,完整切除肿瘤是提高临床疗效的关键。     

Superficial acral fibromyxoma of the toe, with erosion of the distal phalanx. A clinical report

Superficial acral fibromyxoma (SAFM) is a rare soft tissue tumor most often located in the ungual region of the fingers and toes. This tumor was first described in 2001, and since then very few cases have been reported. We present the case of a 35-year-old male with a SAFM located in the toe, with involvement of the nail and erosion of the distal phalanx. The lesion was surgically removed, and the histopathological study confirmed the diagnosis of SAFM. The differential diagnosis must be established with other myxoid tumors and with those lesions showing a predilection for the distal portions of the limbs. After 2 years, the patient remains disease free, with no disability of any kind.