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.

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.

OBJECTIVE: The extensor indicis proprius (EIP) is a muscle of the forearm that originates from the posterior surface of the ulna and the adjacent interosseous membrane and attaches to the index finger. Many anatomical variations of this muscle have been reported in the literature. The extensor digitorum brevis manus (EDBM) is a variant muscle found on the back of the wrist and hand. These muscle variants should be considered in the context of clinical syndromes and reconstructive hand surgery. The aim of the present study was to describe in detail the normal and variant anatomy of these muscles and propose new systematic classifications.
METHODS: Formol-carbol-fixed Europid upper limbs (n = 176) were examined in the Department of Anatomy, Histology and Embryology at the Medical University of Sofia for variations of the EIP and occurrences of the EDBM.
RESULTS: We found normal anatomy in 147 (84%) of the specimens examined and we measured the length and width of the muscle belly and tendon of the EIP. Variations of the EIP in the other 29 upper limbs (16%) included replacement of the EIP by an EIB, coexistence of the EIP and EIB, presence of accessory tendons, and additional muscles.
CONCLUSIONS: Knowledge of anatomical variations of forearm muscles is important because they can cause clinical syndromes or have implications for reconstructive surgery, most often as tendon transfers in response to functional loss of other forearm muscles.

Complications following extensor indicis proprius (EIP) tendon transfer are loss of strength, independence and mobility in the index finger in extension. The main goal of this study was to measure the index finger\'s independent and dependent extension strength after a tendon transfer. Secondary goals were to determine if the index finger retained the ability to extend independently after the transfer and to evaluate second metacarpophalangeal (MCP) joint mobility. Our study consisted of 19 patients in whom the EIP tendon had been divided proximally to the extensor hood. The EIP tendon was retrieved through a proximal approach at the distal radius level and rerouted towards a recipient tendon. At an average follow-up of 41 months, the average independent extension strength was 5.6N versus 11N on the contralateral side and the dependent strength was 10.9N versus 20N. No patient complained of a loss of extension strength and all had retained independent active extension on the operated index finger. The second MCP joint on the operated side had an independent extension lag of 15.3° compared to the contralateral healthy side and a dependent extension lag of 0.2°. Two patients were impaired in their daily activities when moving the operated index finger. Our results show that EIP harvesting for tendon transfer leads to decreased independent and dependent strength as well as decreased active extension of the second MCP joint. However, the functional impact was negligible and should not compromise the use of the EIP as a tendon transfer.
III.

The goal of this study was to establish a reproducible protocol to measure active extension strength in the index finger. The secondary objectives consisted in correlating the independent or associated index extension strength to the other fingers force of contraction of the extensor indicis propius with hand dominance. The population studied consisted of 24 healthy volunteers, including 19 women and 20 right-handed individuals. The independent and dependent index extension strength in each hand was measured three times with a dynamometer by three examiners at Day 0 and again at Day 7. Intra and inter-examiner reproducibility were, respectively, >0.90 and >0.75 in all cases. The independent extension strength was lower than the dependent one. There was no difference between the independent index extension strength on the dominant and non-dominant sides. The same was true for the dependent strength. Our results show that our protocol is reproducible in measuring independent and dependent index extension strength. Dominance did not come into account.
METHODS: II.