BACKGROUND: the rupture of the extensor pollicis longus (EPL) tendon is a rare pathology and usually occurs in adult women in relation to distal radius fractures.
METHODS: we present the case of an adolescent female patient who, after conservative treatment with splinting of a Peterson type I physeal fracture of the radius, suffered an acute extension deficit of the thumb at six weeks, diagnosed with clinical radiological examination as spontaneous rupture of the extensor pollicis longus (EPL). She was treated with extensor pollicis indicis propius (EIP) transfer with satisfactory results and recovering her usual activity one month after surgery.
CONCLUSIONS: this kind of injuries are infrequent in pediatric ages and rarely described in a pediatric patient with immature skeleton, what makes this case something exceptional. It is necessary considering these complications in patients of low ages even with no other risk factors. The most frequent treatment applied in adults as in children is the EIP transference with good results in the long term.
UNASSIGNED: la rotura del tendón extensor pollicis longus (EPL) constituye una patología infrecuente y se presenta normalmente en mujeres adultas en relación con fracturas de radio distal.
UNASSIGNED: se presenta el caso de una paciente adolescente femenino que, tras tratamiento conservador con férula de una fractura fisaria Peterson tipo I en radio, sufre a las seis semanas déficit agudo de extensión del pulgar, diagnosticada mediante examen clínico radiológico de rotura espontánea del extensor pollicis longus. Es tratada por medio de transferencia del extensor propio del índice (EPI) con resultados satisfactorios y recuperación de su actividad habitual al mes postoperatorio.
UNASSIGNED: este tipo de lesiones son poco frecuentes en edad pediátrica y casi nunca descritas en un paciente pediátrico con inmadurez esquelética, lo cual hace de este caso algo excepcional. Es necesario tener en cuenta este tipo de complicaciones en pacientes de baja edad aún sin otros factores de riesgo asociados. El tratamiento aplicado más frecuentemente, tanto en adultos como en niños, es la transferencia del extensor propio del índice con buenos resultados a largo plazo.

OBJECTIVE: Variations of the extensor pollicis longus are rare. When present, these include a separate extensor pollicis longus muscle, tendon or an intertendinous connection with nearby tendons within the deep extensor compartment of the forearm. Here, we report an extremely rare variation of an accessory extensor pollicis longus originating from the extensor digitorum.
METHODS: An unusual muscle was found during the routine dissection forearm of a 71 year-old at death male cadaver.
RESULTS: This variant muscle originated from part of the extensor digitorum muscle belly that supplies the index finger. It became tendinous and entered the third extensor compartment of the wrist before joining the ulnar side of the extensor pollicis longus tendon. Traction on the muscle belly resulted in simultaneous extension of both the thumb and the index finger.
CONCLUSIONS: This study documents an extremely rare extensor tendon to the thumb originating from the extensor digitorum, with a unique attachment to the normal extensor pollicis tendon. There have been minimal accounts of this variation, and the present report adds to the limited literature. Furthermore, the report suggests a new subtype, 1f, be included in the existing classification system. Surgeons should be aware of this rare variant for proper evaluation, diagnosis and surgical treatment. Further anatomical studies are needed to study the prevalence of this variant.

Ganglion cysts are common benign lesions in the hand and wrist. However, intratendinous ganglion cysts are uncommon. We present a case of intratendinous ganglion cyst in the extensor pollicis longus (EPL) tendon of the right hand of a 73-year-old woman. The subcutaneous mass moved in concert with the EPL tendon in her right thumb. Magnetic resonance imaging showed a space-occupying lesion in the EPL tendon. Biochemical and hemato-immunological examinations ruled out diabetes, rheumatoid arthritis, and other connective tissue diseases. She reported motion pain during thumb extension, for which she desired surgery. An intratendinous cyst was identified intraoperatively within the tendon substance of the EPL, in which a part of the cyst was herniated into a slit in the tendon substance, just distal to the extensor retinaculum, without notable proliferative synovial tissue. The EPL tendon was opened longitudinally, and a cystic lesion was enucleated. Pathological examination showed that the cyst wall consisted of fibrous tissue with degeneration and no epithelial lining. Postoperative recovery was uneventful. Six months after surgery, the patient had no residual pain and no cyst recurrence. The rarity of intratendinous ganglion cysts makes diagnosis and treatment challenging. Because intratendinous ganglion cysts and associated synovitis frequently weaken the structure of affected tendons, prompt diagnosis and surgical excision are necessary.

Ruptures of the extensor pollicis longus (EPL) tendon result in a major loss of function. The most practiced reconstruction surgery appears to be extensor indicis proprius (EIP) transfer, which is contraindicated in certain cases. The objective of this review was to present the various reconstruction methods for the EPL tendon. A systematic review was conducted of the literature from 2010 to 2020 on strategies for reconstructing the EPL tendon. A search of the PubMed database was done using the following keywords: \'extensor\', \'pollicis\', \'longus\', and \'thumb\'. Data analyzed were the type of study, the number of patients, surgery, follow-up, and results. Of the 142 articles selected from PubMed, only 18 (12.7%) were included in the analysis. Follow-up ranged from 6 months to 6 years, with an average of 28 months, and the total number of patients was 515. Numerous strategies exist for reconstruction following rupture of the EPL tendon. The preferred modality seems to be a transfer of the EIP tendon with intraoperative testing of applied tension with the interphalangeal joint in extension, hand flat, forearm in pronation, and neutral wrist position. When the EIP is not available, other transfers should be considered if the patient has significant tendon attrition, or a graft should be considered if an isolated defect is present.

We are reporting a case of extensor pollicis longus tendon rupture which did not require tendon transfer owing to the ability of the intact extensor pollicis brevis (EPB) to fully hyperextend the thumb interphalangeal joint. The thumb metacarpophalangeal joint was also able to be fully actively extended by the EPB. Previous anatomical studies have demonstrated that the insertional anatomy of the EPB tendon is highly variable and sometimes inserts onto the extensor hood and distal phalanx, which is likely the mechanism by which our patient was able to fully extend the thumb interphalangeal joint. Despite the potential for the EPB to extend the IP joint of the thumb, virtually all previously reported cases of extensor pollicis longus (EPL) tendon rupture had deficits of thumb IP extension requiring tendon transfer. This case highlights the potential ability of the EPB tendon to completely substitute for the function of the EPL tendon in providing thumb IP joint extension.