summary Flexor Tendon Injuries are traumatic injuries to the flexor digitorum superficialis and flexor digitorum profundus tendons that can be caused by laceration or trauma. Diagnosis is made clinically by observing the resting posture of the hand to assess the digital cascade and the absence of the tenodesis effect. Treatment is usually direct end-to-end tendon repair. Epidemiology Incidence rare login to view 1 more bullet Etiology Pathophysiology mechanism of injury login to view 1 more bullet pathophysiology login to view 9 more bullets Anatomy Muscles flexor digitorum profundus (FDP) login to view 6 more bullets flexor digitorum superficialis (FDS) login to view 5 more bullets flexor pollicis longus (FPL) login to view 2 more bullets flexor carpi radialis (FCR) login to view 4 more bullets flexor carpi ulnaris (FCU) login to view 3 more bullets Camper chiasm located at the level of the proximal phalanx where FDP splits FDS Pulley system digits 2-5 contain login to view 8 more bullets thumb contains login to view 4 more bullets Blood supply 2 sources exist login to view 10 more bullets Classification Flexor Zones of Injury Zone Definition Characteristics Treatment I Distal to FDS insertion Jersey finger Direct tendon repair II FDS insertion to distal palmar crease/proximal A1 pulley Zone is unique in that FDP and FDS in same tendon sheath (both can be injured within the flexor retinaculum). Tendons can retract if vincula are disrupted. Direct tendon repair followed by early ROM (Duran, Kleinert). This zone historically had very poor results but results have improved due to advances in postoperative motion protocols. III Palm (A1 pulley to distal aspect of carpal ligament) Often associated with neurovascular injury which carries a worse prognosis. Direct tendon repair. Good results from direct repair can be expected due to absence of retinacular structures (if no neurovascular injury). May require A1 pulley release to avoid impingement of the repaired tendon on the pulley. IV Carpal tunnel Often complicated by postoperative adhesions due to close quarters and synovial sheath of the carpal tunnel. Direct tendon repair. Transverse carpal ligament should be repaired in a lengthened fashion if tendon bowstringing is present. V Carpel tunnel to forearm Often associated with neurovascular injury which carries a worse prognosis. Direct tendon repair Thumb TI, TII, TIII Outcomes different than fingers. Early motion protocols do not improve long-term results and there is a higher re-rupture rate than flexor tendon repair in fingers. Direct end-to-end repair of FPL is advocated. Try to avoid Zone III to avoid injury to the recurrent motor branch of the median nerve. Oblique pulley is more important than the A1 pulley; however both may be incised if necessary. Attempt to leave one pulley intact to prevent bowstringing Presentation Symptoms loss of active flexion strength or motion of the involved digit(s) Physical exam inspection login to view 4 more bullets motion login to view 4 more bullets neurovascular login to view 1 more bullet Imaging Radiographs may have associated fracture Ultrasound used to assess suspected lacerations Treatment Nonoperative wound care and early range of motion login to view 4 more bullets Operative flexor tendon repair and controlled mobilization login to view 2 more bullets flexor tendon reconstruction and intensive postoperative rehabilitation login to view 3 more bullets FDS4 transfer to thumb login to view 3 more bullets Techniques Flexor tendon repair indications login to view 4 more bullets fundamentals of repair login to view 6 more bullets timing of repair login to view 2 more bullets approach login to view 2 more bullets technique login to view 30 more bullets outcomes login to view 6 more bullets Wide-awake flexor tendon repair anesthesia login to view 17 more bullets 4 advantages login to view 8 more bullets Flexor tendon reconstruction requirements login to view 4 more bullets techniques login to view 36 more bullets outcomes login to view 1 more bullet Tenolysis indications login to view 2 more bullets timing of procedure login to view 1 more bullet technique login to view 1 more bullet postoperative care login to view 1 more bullet Postoperative Rehabilitation Postoperative controlled mobilization has been the major reason for improved results with tendon repair especially in zone II leads to improved tendon healing biology limits restrictive adhesions and leads to increased tendon excursion Protocols Immobilization login to view 2 more bullets Early passive motion login to view 9 more bullets Early active motion login to view 3 more bullets Complications Tendon adhesions most common complication following flexor tendon repair higher risk with zone 2 injuries treatment login to view 3 more bullets Rerupture 15-25% rerupture rate treatment login to view 4 more bullets Joint contracture rates as high as 17% Swan-neck deformity Trigger finger Lumbrical plus finger Quadrigia