What is the recommended treatment for a patient with mild tendinosis of the flexor pollicis longus (FPL) tendon and a ganglion cyst superior to the pisotriquetral joint?

Treatment for Mild FPL Tendinosis and Ganglion Cyst

For mild flexor pollicis longus tendinosis, initiate conservative management with relative rest, activity modification, thumb spica splinting, NSAIDs (preferably topical), and eccentric strengthening exercises once acute symptoms subside; the ganglion cyst superior to the pisotriquetral joint requires observation only unless symptomatic, in which case aspiration or surgical excision should be considered. 1, 2, 3

Management of FPL Tendinosis

First-Line Conservative Treatment

• Relative rest is essential—reduce or eliminate repetitive loading activities that stress the FPL tendon, particularly pinching, gripping, and thumb flexion movements 3

• Thumb spica splinting immobilizes the first dorsal compartment and rests the affected tendon, serving as foundational first-line treatment 2, 3

• NSAIDs for pain control: Topical NSAIDs are preferable to oral formulations as they provide equivalent pain relief while eliminating gastrointestinal hemorrhage risk 3

• Cryotherapy (ice application) provides acute pain relief and reduces swelling 3

Progressive Rehabilitation

• Eccentric strengthening exercises are the cornerstone of tendinopathy treatment and should be initiated once acute pain subsides—these exercises stimulate collagen production and guide proper alignment of healing collagen fibers, potentially reversing degenerative tendon changes 1, 3

• Stretching exercises are widely accepted for tendon rehabilitation and should be incorporated into the treatment plan 3

• Approximately 80% of patients with overuse tendinopathies fully recover within 3-6 months with appropriate conservative treatment 3

Second-Line Interventions

• Corticosteroid injection into the tendon sheath (NOT into tendon substance) may be considered for persistent acute phase symptoms, though it provides only short-term relief without altering long-term outcomes 1, 3

• Critical caveat: Avoid injecting directly into the tendon substance as this inhibits healing, reduces tensile strength, and may cause rupture; limit to maximum 2-3 injections 1, 2, 3

• Ultrasound-guided injection improves accuracy and is recommended 2

• Extracorporeal shock wave therapy is a safe, noninvasive option for chronic cases, though expensive 1, 2

Surgical Referral Criteria

• Refer for surgical evaluation only if pain persists despite 3-6 months of well-managed conservative treatment 2, 3

Management of Ganglion Cyst

Observation vs. Intervention

• Asymptomatic ganglion cysts (like the 1.1 x 0.8 cm cyst superior to the pisotriquetral joint in this case) can be observed, as ultrasound accuracy for diagnosing ganglion cysts is similar to MRI 4

• Symptomatic cysts causing pain, functional limitation, or cosmetic concerns warrant intervention 4

Treatment Options for Symptomatic Cysts

• Ultrasound-guided aspiration can be attempted for symptomatic relief, though recurrence rates are high 4

• Surgical excision is definitive treatment for persistent or recurrent symptomatic ganglion cysts 4

• Special consideration: While most ganglion cysts are benign and extra-tendinous, intratendinous ganglion cysts are rare but pose unique risks including tendon weakening and spontaneous rupture—these require prompt surgical excision 5, 6

• The location of this cyst (superior to pisotriquetral joint) suggests it is likely extra-tendinous and standard observation/aspiration/excision principles apply 4

Critical Pitfalls to Avoid

• Do not immobilize completely beyond what thumb spica splinting provides, as prolonged immobilization causes muscle atrophy and deconditioning 1, 3

• Never inject corticosteroids into tendon substance—only into the tendon sheath to avoid tendon weakening and rupture 1, 3

• Do not proceed to surgery without an adequate 3-6 month trial of conservative treatment 1, 2, 3

• Avoid multiple corticosteroid injections (maximum 2-3) as they may weaken tendon structure despite providing short-term relief 1, 2

• If multiple tendons are symptomatic, evaluate for underlying rheumatic disease rather than treating as isolated tendinopathy 1

Prognosis and Follow-up

• Continue splinting and activity modification throughout the conservative treatment period 2

• Re-evaluate at 3-6 months to assess response to conservative management before considering surgical options 2, 3

• The mild nature of the tendinosis in this case suggests excellent prognosis with conservative management alone 3