Forty-eight digits from 12 human adult fresh-frozen and formalin-preserved cadaveric hands were used to study the anatomy and biomechanics of the sagittal band (SB) and to investigate the mechanism of its injury. The SB was observed to be part of a complex retinacular system in proximity to the metacarpophalangeal (MCP) joint collateral ligaments and the palmar plate. Dynamic changes in SB fiber orientation were observed with different positions of the MCP and wrist joints. The fibers were perpendicular (0°) to the extensor tendon in neutral position, distally angulated 25° at 45° of MCP flexion, and 55° with full flexion. Swan-Ganz catheter measurements were obtained deep to the SB in varying positions of the MCP joint. The average pressure generation was greatest (50 mm Hg) during full MCP joint flexion and least (30 mm Hg) during 45° flexion. When MCP joint radial or ulnar deviation was added the average measurement was greatest (57) in neutral MCP position and least (35 mm Hg) in 45° flexion. Serial sectioning of the ulnar SB produced no extensor tendon instability. Partial proximal but not distal sectioning of the radial SB produced tendon subluxation. Complete sectioning of the radial SB produced tendon dislocation. Wrist flexion increased tendon instability after radial SB sectioning. We conclude that (1) extensor tendon instability following SB disruption is most common in the long finger and least common in the small finger; (2) ulnar instability of the extensor tendon is due to partial or complete radial SB disruption, (3) the degree of extensor tendon instability is determined by the extent of SB disruption, (4) proximal rather than distal SB compromise contributes to extensor tendon instability, (5) great forces are inflicted on the SB while the MCP joint is in full extension or less frequently in full flexion, which may be the mechanism of its injury, and (6) wrist flexion contributes to extensor tendon instability after SB disruption and may exacerbate the severity of its injury. (J Hand Surg 2000;25A:1107-1113. Copyright © 2000 by the American Society for Surgery of the Hand.)
To read this article in full you will need to make a payment
Purchase one-time access:Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
One-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:Subscribe to Journal of Hand Surgery
Already a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
- The extensor retinacular system at the metacarpophalangeal joint: anatomical and histological study.J Hand Surg. 1997; 22B: 585-590
- Recurrent dislocation of extensor tendons in the hand.J Bone Joint Surg. 1954; 36B: 612-617
- Extensor mechanism of the fingers: a quantitative geometric study.J Hand Surg. 1991; 16A: 1130-1136
- Traumatic dislocation of the long finger extensor tendon: a clinical, anatomical and biomechanical study.J Bone J Surg. 1971; 53A: 229-240
- Bunnell's surgery of the hand.in: 4th ed. JB Lippincott, Philadelphia1984: 343-346 (470-471)
- The anatomy of the dorsal aponeurosis of the human finger and its functional significance.Anat Rec. 1949; 104: 31-43
- Anatomy injuries and treatment of the extensor apparatus of the hand and the digits.Clin Orthop. 1959; 13: 14-41
- Retaining ligaments of the digit of the hand.in: WB Saunders, Philadelphia1968: 26-27
- The functional anatomy of the extensor mechanism of the finger.J Bone Joint Surg. 1972; 54A: 713-726
- Structural and dynamic bases of hand surgery.in: 2nd Ed. JB Lippincott, Philadelphia1979: 3-36
- Palmar fascial complex anatomy and pathology in Dupuytren's disease.Hand Clin. 1999; 15: 73-86
- Abducted hyperextended small finger deformity of nonneurologic etiology.J Hand Surg. 1999; 24A: 319-351
- Classification and treatment of closed sagittal band injuries.J Hand Surg. 1994; 19A: 590-594
- Closed crush injury of the metacarpophalangeal joint.J Hand Surg. 1987; 12A: 750-757
Accepted: June 6, 2000
Received: January 25, 2000
*No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article.
**Reprint requests: Ghazi M. Rayan, MD, 3366 NW Expressway #700, Oklahoma City, OK 73112.
© 2000 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.