Proximal extensor mechanism reconstruction: modern principles in zone IX injuries: a case report
DOI:
https://doi.org/10.18203/2349-2902.isj20263003Keywords:
Extensor tendon injury, Zone IX, Proximal forearm, Extensor digitorum communis, Tendon repair, Posterior interosseous nerve, Hand surgeryAbstract
Zone IX extensor tendon injuries of the forearm are uncommon but complex lesions involving the musculotendinous unit and, frequently, the posterior interosseous nerve, resulting in significant functional impairment despite limited external injury. We present the case of a 27-year-old woman with a sharp laceration to the proximal dorsal forearm causing complete loss of active extension of the second through fifth digits. Surgical exploration confirmed complete transection of the extensor digitorum communis tendons with proximal retraction, which were repaired primarily using U-shaped 3-0 absorbable Vicryl sutures, followed by postoperative immobilization in a functional extension position. A narrative review of the current literature addressing epidemiology, anatomy, imaging, surgical management, suture biomechanics, and rehabilitation of zone IX extensor injuries was also performed. This case highlights that successful management requires comprehensive anatomical assessment, evaluation of posterior interosseous nerve integrity, stable primary repair with appropriate tension, and structured rehabilitation. It also emphasizes the limited evidence available for these injuries and the need for further research on zone-specific epidemiology, rehabilitation protocols, and biological augmentation strategies to optimize functional outcomes.
Metrics
References
Rockwell WB, Butler PN, Byrne BA. Extensor tendon: anatomy, injury, and reconstruction. Plast Reconstr Surg. 2000;106(7):1592-603. DOI: https://doi.org/10.1097/00006534-200012000-00024
Griffin M, Hindocha S, Jordan D, Saleh M, Khan W. Management of extensor tendon injuries. Open Orthop J. 2012;6:36-42. DOI: https://doi.org/10.2174/1874325001206010036
Evans RB. Managing the injured tendon: current concepts. J Hand Ther. 2012;25(2):173-89. DOI: https://doi.org/10.1016/j.jht.2011.10.004
Verdan CE. Primary and secondary repair of flexor and extensor tendon injuries. In: Hand Surgery, Flynn JE (ed), editors. Williams & Willkins: Baltimore; 1966;220-42.
Lim Y, Lim SK, Beswick W, Razo M, Dustagheer S. Outcomes of outpatient hand extensor tendon injury repairs in Northern Ireland's regional plastic surgery service. Injury. 2025;56(10):112647. DOI: https://doi.org/10.1016/j.injury.2025.112647
Tang JB, Fernandes CH, Lalonde D, Moriya K, Vögelin E, Ayhan E, et al. Extensor tendon repairs: consensus, current guidelines and recommendations. J Hand Surg Eur Vol. 2025;50(9):1153-62. DOI: https://doi.org/10.1177/17531934251363138
Dalton SS, Maharjan LM, Yousuf H, Pientka WF 2nd. Extensor Tendon Repair Outcomes Based on Zone of Injury. Hand (N Y). 2024;19(5):831-6. DOI: https://doi.org/10.1177/15589447221150510
Arroyo-Berezowsky C, Quinzaños-Fresnedo J. Epidemiology of hand and wrist injuries treated in a reference specialty center over a year. Acta Ortop Mex. 2021;35(5):429-35. DOI: https://doi.org/10.35366/104570
de Jong JP, Nguyen JT, Sonnema AJ, Nguyen EC, Amadio PC, Moran SL. The incidence of acute traumatic tendon injuries in the hand and wrist: a 10-year population-based study. Clin Orthop Surg. 2014;6(2):196-202. DOI: https://doi.org/10.4055/cios.2014.6.2.196
Kleinert HE, Verdan C. Report of the Committee on Tendon Injuries (International Federation of Societies for Surgery of the Hand). J Hand Surg Am. 1983;8(5 Pt 2):794-8. DOI: https://doi.org/10.1016/S0363-5023(83)80275-5
Fischer CR, Tang P. Lacerations to Zones VIII and IX: It Is Not Just a Tendon Injury. Adv Orthop. 2011;2011:261681. DOI: https://doi.org/10.4061/2011/261681
Tang JB. Clarification and classification of extensor tendon zones in the hand. J Hand Surg Eur Vol. 2024;49(8):1041-4. DOI: https://doi.org/10.1177/17531934241232066
Borges ÁVRM, Souza SAL. Anatomy of the nerves, vessels, and muscular compartments of the forearm, as revealed by high-resolution ultrasound. Part 1: overall structure and forearm compartments. Radiol Bras. 2021;54(6):388-97. DOI: https://doi.org/10.1590/0100-3984.2021.0030
Mohana-Borges AVR, Souza SAL. Anatomy of the nerves, vessels, and muscular compartments of the forearm, as revealed by high-resolution ultrasound. Part 2: Vascularization of compartments and cutaneous innervation. Radiologia Brasileira. 2021;54(6):398-405. DOI: https://doi.org/10.1590/0100-3984.2021.0031
Jeon A, Kim YG, Kwon SO, Lee JH. Relationship between the Branching Patterns of the Radial Nerve and Supinator Muscle. Biomed Res Int. 2021;2021:8691114. DOI: https://doi.org/10.1155/2021/8691114
Sawyer FK, Stefanik JJ, Lufler RS. The Branching and Innervation Pattern of the Radial Nerve in the Forearm: Clarifying the Literature and Understanding Variations and Their Clinical Implications. Diagnostics (Basel). 2020;10(6):366. DOI: https://doi.org/10.3390/diagnostics10060366
Bezirgan U, Acar E, Erdoğan Y, Armangil M. The diagnostic value of ultrasonography and magnetic resonance imaging in missed hand tendon injuries. Ulus Travma Acil Cerrahi Derg. 2023;29(4):530-7. DOI: https://doi.org/10.14744/tjtes.2023.78622
Kumar U, Bera S, Jaiswal S, Jain S, Mishra A. High-resolution ultrasonography as an adjuvant diagnostic tool in preoperative assessment of acute forearm lacerations. Injury. 2025;56(8):112465. DOI: https://doi.org/10.1016/j.injury.2025.112465
Dickson K, Mantelakis A, Reed AJM, Izadi D, Wade RG, Wormald J, et al. The management of partial extensor tendon lacerations of the hand and forearm: A systematic review. J Plast Reconstr Aesthet Surg. 2023;85:34-43. DOI: https://doi.org/10.1016/j.bjps.2023.06.004
Reed AJ, Wade RG, Wormald JC, Dickson K, Mantelakis A, Izadi D, et al; PETAL collaborative. Management of partial extensor tendon lacerations of the hand and forearm: A national survey of practice in the United Kingdom. J Plast Reconstr Aesthet Surg. 2025;101:46-52. DOI: https://doi.org/10.1016/j.bjps.2024.11.028
Castillo AC, Kaltwasser K, Morris R, Sanchez ER, Rai S, Lombana N, et al. Comparing 3 Suture Techniques After Muscle Laceration Repair. Hand (N Y). 2021;16(1):67-72. DOI: https://doi.org/10.1177/1558944719837021
Al-Qattan MM, Al Mohrij SA. A modified technique of two-staged extensor tendon reconstruction in zones 6-8 in a patient with absent palmaris/plantaris tendons: A case report. Int J Surg Case Rep. 2019;55:99-102. DOI: https://doi.org/10.1016/j.ijscr.2019.01.023
Tafti AA, Mohammadi H, Rezaei M, Bonadaki SHS. Use of a bioresorbable polylactide sheet (OrthoWrap® Bioresorbable sheet) on tendon healing after extensor tendon repair: a controlled clinical trial. BMC Musculoskelet Disord. 2025;26(1):1. DOI: https://doi.org/10.1186/s12891-024-08241-z
Pluchino M, Vivarelli L, Giavaresi G, Dallari D, Govoni M. Commercial Biomaterial-Based Products for Tendon Surgical Augmentation: A Scoping Review on Currently Available Medical Devices. J Funct Biomat. 2025;16(4):130. DOI: https://doi.org/10.3390/jfb16040130
Rawson S, Cartmell S, Wong J. Suture techniques for tendon repair; a comparative review. Muscles Ligaments Tendons J. 2013;3(3):220-8. DOI: https://doi.org/10.32098/mltj.03.2013.16
Botte MJ, Gelberman RH, Smith DG, Silver MA, Gellman H. Repair of severe muscle belly lacerations using a tendon graft. J Hand Surg Am. 1987;12(3):406-12. DOI: https://doi.org/10.1016/S0363-5023(87)80014-X
Stulginski A, Vallurupalli M, Pakvasa M, Tang CJ, Wang ED, Leis AR. Evaluating suturing methods for surgical repair of muscle belly lacerations: A scoping review of biomechanical studies. Eur J Plast Surg. 2024;47(1):23. DOI: https://doi.org/10.1007/s00238-024-02161-w
Blair WF, Newport ML. Extensor tendon injuries. Orthop Clin North Am. 1992;23(1):141-8. DOI: https://doi.org/10.1016/S0030-5898(20)31721-1
Downloads
Published
How to Cite
Issue
Section
