UNASSIGNED: IV.

A spontaneous rupture of the extensor pollicis longus (EPL) tendon after a fracture of the distal radius is a known complication in adults. In contrast, there are a paucity of reports concerning EPL tendon ruptures in children and adolescents. The authors present a case of a spontaneous rupture of the EPL tendon in a 15-year-old girl after a non-displaced distal radius fracture. The patient had no predisposing factors including rheumatoid arthritis or steroid injection. During surgery, the EPL tendon was found to be ruptured at the extensor retinaculum (third compartment). Extensor indicis proprius (EIP) to EPL transfer was performed. At the 18-month follow-up, the patient was asymptomatic and showed satisfactory thumb function, with normal active extension.
La rotura espontánea del tendón del extensor largo del pulgar (EPL) tras una fractura distal del radio es una complicación conocida en adultos. En cambio, son escasos los informes sobre roturas del tendón del EPL en niños y adolescentes. Los autores presentan un caso de rotura espontánea del tendón del EPL en una niña de 15 años tras una fractura distal del radio no desplazada. La paciente no presentaba factores predisponentes como artritis reumatoide o inyección de esteroides. Durante la intervención quirúrgica, se descubrió que el tendón del EPL estaba roto a la altura del retináculo extensor (tercer compartimento). Se realizó una transferencia del extensor indicis proprius (EIP) al EPL. A los 18 meses de seguimiento, el paciente estaba asintomático y mostraba una función satisfactoria del pulgar, con una extensión activa normal.

UNASSIGNED: Hardware prominence is one of the major established complications following volar plating of distal radius fractures. In particular, dorsal prominence of screws is the leading risk factor associated with post-surgical extensor pollicis longus (EPL) tendon rupture. Although there are many descriptions of attritional EPL ruptures in the literature, concomitant presentation of attritional EPL and extensor digitorum communis (EDC) ruptures following volar plating of distal radius fractures are minimal.
UNASSIGNED: We present a case of concomitant rupture of the EPL and occult rupture of the EDC to the index finger following volar plating of the distal radius. This was discovered intraoperatively and complicated the proposed tendon transfer reconstruction.
UNASSIGNED: Locked volar plate fixation has become the preferred technique for surgical management of distal radius fractures. The complication of multiple extensor tendon ruptures is rare but nevertheless may be encountered. We discuss strategies for diagnosis, treatment, and prevention. Surgeons should be aware of and prepared to proceed with alternative reconstructive procedures if this complication is discovered.

BACKGROUND: The extensor indicis proprius (EIP) tendon is a frequently used donor for a variety of tendon transfers, most commonly for reconstruction of the extensor pollicis longus (EPL). EIP is known to have frequent anatomic variants including split tendons and variations in tendon arrangement.
OBJECTIVE: To characterize the anatomy of the EIP at the level of the extensor retinaculum, where tendon harvest is often performed, and share our preferred technique for EIP to EPL transfer.
METHODS: Twenty-nine fresh-frozen cadaveric forearms without history of forearm or hand injury or surgery were dissected. Tendon circumference and relationship of the EIP and extensor digitorum communis to the index (EDCI) at the metacarpophalangeal (MCP) joint and the distal extensor retinaculum were recorded. Distance from the distal extensor retinaculum to the EIP myotendinous junction was measured.
RESULTS: EIP was ulnar to the EDCI in 96.5% of specimens (28/29) at the distal edge of the extensor retinaculum. In the remaining specimen, EIP was volar to EDCI. Tendon circumference at the distal extensor retinaculum averaged (9.3 mm ± 1.7 mm) for EDCI and 11.1 mm (± 2.7 mm) for EIP (P = 0.0010). The tendon circumference at the index MCP joint averaged 11.0 mm (± 1.7 mm) for EDCI and 10.6 mm (± 2.1 mm) for EIP (P = 0.33). EIP had a greater circumference in 76% (22/29) of specimens at the distal extensor retinaculum whereas EIP had a greater circumference in only 31% (9/29) of specimens at the MCP joint.
CONCLUSIONS: The EIP tendon is frequently ulnar to and greater in circumference than the EDCI at the distal extensor retinaculum, which can be taken into consideration for tendon transfers involving EIP.

Many conditions are known to cause chronic wrist pain, one of which is accessory muscles which can be easily overlooked as the cause of pain. Here we present a case of chronic wrist pain in a 33-year-old male who presented with painful dorsal unilateral right-hand swelling associated with increased activity. This patient was referred to the radiology department and was found to have an accessory muscle along the dorsal aspect of the wrist consistent with the extensor digitorum brevis manus muscle. The report includes the clinical presentation, radiologic findings, and management.

We presumed that primary repair would be possible if the extensor pollicis longus (EPL) rupture after volar locking plating (VLP) for distal radius fracture (DRF) was diagnosed earlier. Thus, five cases of EPL ruptures were resolved via primary repair rather than extensor indicis proprius (EIP) transfer, so we reported the clinical outcomes of at least 2 years follow-up since EPL repair. Of 588 consecutive patients with the fractures treated between January 2016 and December 2019, 501 who met out inclusion/exclusion criteria were initially investigated. We informed patients of: (1) the ordinary range of motion of thumb at full wrist flexion/extension; (2) the proper tone of thumb extension compared to the contralateral thumb; and (3) the degree of pain/discomfort during thumb exercise. After discharge, we called each patient monthly commencing at 8 weeks postoperatively to enquire if any of those had worsened, by telephone. Five patients had ruptured EPLs diagnosed at a mean of postoperative-12.8 weeks. Three came to outpatient department for suspected tendon rupture just after telephone survey with the authors. The other two visited after detecting insufficiency in the three items, during the period between telephone inquiries. In four, the torn EPL were encapsulated by tendon sheathes. Extension lag at interphalangeal joint was absent and other clinical outcomes associated with DRF were all satisfactory at final follow-up. Primary repair of EPL rupture (rather than EIP transfer) is possible if patients are properly followed up after VLP for DRF. LEVEL OF EVIDENCE: Level IV, retrospective case series.

The choice of the donor tendon in tendon reconstruction of the hand theoretically influences the results of the surgery because of the interactions of its structure with the healing process. The objective of our study was to specify the surgical bases of vascularized extensor indicis proprius (EIP) in tendon reconstruction of the hand and to present its application from a series of observations. According to our observations, the EIP\'s vascularization arises from a branch of the 2nd dorsal metacarpal artery, 3-4 cm proximally to the metacarpophalangeal joint (MCP). We demonstrate the feasibility and effectiveness of a vascularized EIP graft for finger flexor tendon reconstruction, for defects of the extensor mechanism at the MCP joint level and for reconstruction of the extensor pollicis longus. Our biomimetic approach in tendon reconstruction has led us to factor in the complexity of the tendon and peritendinous structure. The use of vascularized EIP offers theoretical advantages for the tendon healing process, demonstrates encouraging first results with interesting versatility and very low iatrogenicity.

Extensor indicis proprius (EIP) tendon transfer is a standard operation for restoration of the thumb extension following rupture of extensor pollicis longus (EPL). In its standard form often the EIP is transferred to the EPL without inspection of the extensor tendons in the fourth compartment and it is retained in its anatomical fourth compartment. However, in a setting of EPL rupture in relation to the distal radius fracture (with or without fixation), concomitant injury to the extensor tendons to the index finger may result in failure of the transfer and even a loss of index finger extension (index finger drop) further complicating the reconstruction and resulting in immense patient dissatisfaction. We herein present two such rare cases to highlight this clinical scenario and how an awareness of this possibility and inspection of the extensor tendons to the index finger before EIP transfer allowed us to prevent this complication. In essence, if we know it, we can prevent it.

OBJECTIVE: Anatomical variants in the posterior compartment of forearm and hand are not uncommon. Physicians should be aware of variations in this region for correct diagnosis and treatment of diseased hands.
METHODS: During a routine dissection at our department, an extremely rare case of deep hand extensor muscle was discovered.
RESULTS: A complete extensor digitorum profundus complex was found in the fourth extensor compartment in addition to the extensor indicis proprius. The complex consisted of two muscle bellies originating from the lateral aspect of distal ulna and the adjacent interosseous membrane. The first belly resembled the conventional extensor indicis proprius. The second belly gave off two tendon slips: one inserted to the index and middle fingers and the other formed aponeurosis before inserting to the ring and little fingers.
CONCLUSIONS: To our knowledge, a complete extensor digitorum profundus complex which inserts to all medial four digits has never been reported in humans. Awareness of variations in this region is critical for surgeons operating in the forearm and hand. The present case also provides insights into the evolutionary and developmental origin of these structures.

Entrapment of the extensor indicis proprius (EIP) after open reduction and internal fixation (ORIF) of the distal ulna with a plate and screw construct is rare. By literature review, we found evidence of such complication associated with distal radius fracture, but no past reports relating to the distal ulna. ORIF of the distal ulna is a common procedure for both fracture treatment and deformity correction. Due to the EIP muscle originating primarily from the dorsoradial surface of the distal ulna and the adjacent interosseous membrane, the muscle may be damaged or compressed by a fixation plate during ORIF, resulting in entrapment. We present two case reports of this rare complication, describing the method of clinical diagnosis, surgical treatment, and outcome. Our accompanying cadaver dissection provides an explanation for proper plate positioning during ORIF of the ulna to reduce the risk of EIP entrapment.