Anatomy of the extensor tendons to the index finger

Department of Orthopaedic Surgery, University of Illinois at Chicago 60612-7342, USA.
The Journal Of Hand Surgery (Impact Factor: 1.66). 12/1996; 21(6):988-91. DOI: 10.1016/S0363-5023(96)80305-4
Source: PubMed

ABSTRACT An anatomic study was performed to better delineate the extensor tendons of the index finger. Seventy-two cadaver hands were dissected. Classically, a single slip of the extensor digitorum communis (EDC) and a single slip of the extensor indicis proprius (EIP) are said to run to the index finger. The EIP is said to be ulnar to the EDC at the level of the metacarpal head. In dissections in this study, the classic description was noted in 58 of the hands. Ten hands had a double slip of the EIP. Two hands had a double slip of the EDC running to the index. Two hands had a single slip of the EIP either volar or radial to the EDC at the level of the metacarpal head. Thirteen hands (19%) showed anatomic variants of the EIP and EDC tendons at the level of the metacarpal head, differing from the classic description. Additionally, two hands showed aberrant tendons. A knowledge of these variants when performing tendon repair or EIP transfer is necessary.

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    ABSTRACT: The purpose of this study is to document the topographic anatomy of an extensor indicis (EI) muscle with a double tendon and the associated distribution of the deep branch of the radial nerve (DBRN). Both EI tendons were positioned deep to the tendons of the extensor digitorum as they traversed the dorsal osseofibrous tunnel. They then joined the medial slips of the extensor expansion of the second and third digits. In all other dissected forearms, a tendon of the EI muscle joined the medial slip of the extensor expansion to the index finger. The DBRN provided short branches to the superficial extensor muscles, long branches to the abductor pollicis longus and extensor pollicis brevis muscles, and terminated as the posterior interosseous nerve. Descending deep to the extensor pollicis longus muscle, the posterior interosseous nerve sent branches to the extensor pollicis brevis and EI muscles. Understanding of the topographic anatomy of an EI with a double tendon, and the associated distribution of the DBRN, may contribute to accurate diagnosis and treatment of hand lesions.
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    ABSTRACT: Variations of the extensor group of muscles in the superior extremity are commonly reported. We are reporting a case of bilateral complete absence of extensor indices muscle. Variation of the extensor indices is not uncommon showing cases with two, three and four tendons going to index fingers have been reported by many workers. The cases with bilateral absence of this muscle are barely reported, incidence usually ranging from 0 to 1 %. In a single study a high frequency of 4% has also been reported.
    01/2014; ISSN:976-9633. DOI:10.7439/ijbr.v5i1.442
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    ABSTRACT: The tendon of the extensor indicis (EI) is frequently used to restore the loss of function in other digits. However, it shows many variations which include splitting of the extensor indicis proprius (EIP) into two or three distal slips, attachment to fingers other than the index such as the extensor medii proprius (EMP), attachment onto the index and the third finger such as the extensor indicis et medii communis, or attachment to both the index and the thumb such as the extensor pollicis et indicis (EPI). This systematic review gathers the available data on the prevalence of EI tendon and its variation in the hand. Twenty-nine cadaveric studies met the inclusion criteria with a total of 3858 hands. Meta-analysis results yielded an overall pooled prevalence estimate (PPE) of EI of 96.5 % and PPEs of 92.6, 7.2 and 0.3 % for the single-, double- and triple-slip EIP, respectively. The single-slip EIP is frequently inserted on the ulnar side of the extensor digitorum communis of the index (EDC-index) in 98.3 %. The double-slip EIP is located on the ulnar side of the EDC-index in 53.5 %, on its radial side in 17 % and on both sides in 28.7 %. Indian populations showed the highest rate of single-slip EIP and the lowest rate of double-slip EIP when compared to Japanese, Europeans and North Americans. The pooled prevalence of EMP, EMIC and EPI were 3.7, 1.6 and 0.75 %, respectively. Knowledge of the variants of the EI tendon and their prevalence should help surgeons in correctly choosing the tendon to transfer in hand surgery.
    Surgical and Radiologic Anatomy 08/2014; 37(3). DOI:10.1007/s00276-014-1352-0 · 1.33 Impact Factor