Hand

Also known as Stenosing tenosynovitis A flexor tendon becomes trapped by thickening at the entrance to its sheath Forced extension -> tendon passes the constriction by snapping/triggering Secondary nodule can develop on the tendon Unknown etiology, more common in diabetic patients Rheumatoid arthritis -> synovial thickening, intra-tendinous nodules -> triggering Thumb, ring and middle fingers are most commonly affected Anatomy Flexor pulley system (fingers except thumb) Annular pulleys (A1 - A5) -> prevent bowstringing Cruciate pulleys (C1 - C3) -> prevent sheath collapse and expansion Palmar aponeurosis pulley (PA) Flexor pulley system (thumb) Annular pulleys (A1, Av, A2) -> prevent bowstringing Oblique pulley -> same as cruciate pulleys in other fingers Clinical features Inability to extend the flexed digit and/or flex the extended digit Patient notices click during flexion. While extending, the finger remains bent at the PIP joint -> with further effort it suddenly extends with a snap Patient may notice a tender lump/knot/nodule in the palm in front of the MCP joint. It may be Thickened area in the pulley Nodular/fusiform swelling of the flexor tendon e.g. by healing of a partially lacerated tendon. The tendon nodule is usually proximal to the pulley, it may be distal in patients with rheumatoid arthritis Triggering after surgical release may occur due to catching of the tendon in the palmar aponeurosis. This resolves over time. Treatment Stretching, night splinting, combination of heat and ice Corticosteroid injection at the mouth of the sheath Recurrence within 6 months occurs in 30% cases, especially younger and diabetic ones. A second injection may be given. Refractory cases need surgery Release of the pulley Thumb -> only A1, other fingers -> A1 + A0 (PA) Care should be taken to avoid injury to the digital neurovascular bundles, risk is greatest in the thumb (nerves are close to midline) and the index (radial digital nerve crosses the tendon) Flexor synovectomy with excision of one slip of flexor digitorum superficialis (in rheumatoid arthritis patient) In babies, wait until 3 years of age. If no spontaneous recovery -> A1 pulley release