What is the prognosis and treatment for a scapholunate injury caused by pushups?

Scapholunate Injury from Pushups: Prognosis and Management

Scapholunate ligament injuries from pushups have a favorable prognosis when diagnosed early and treated appropriately, with 88% of patients achieving excellent or good functional outcomes following surgical repair of acute injuries, though chronic untreated injuries can progress to disabling degenerative arthritis. 1

Mechanism and Clinical Context

Scapholunate ligament injuries typically occur from falls on an outstretched hand with wrist hyperextension, but repetitive axial loading on the wrist in hyperextension—such as during pushups—can lead to functional overloading of the scapholunate interosseous ligament (SLIL). 2 This mechanism is well-documented in volleyball players performing reception and digging motions, which biomechanically resemble the loading pattern during pushups. 2

Diagnostic Approach

Initial Imaging

• Start with conventional radiographs with careful attention to positioning, including posteroanterior, lateral, and stress views (radial/ulnar deviation or clenched fist views). 3, 4
• In low-grade injuries, standard radiographs are usually normal. 3
• Look for scapholunate diastasis >4 mm and dorsal tilt of the lunate >10°, which suggests dorsal intercalated segmental instability (DISI). 3

Advanced Imaging When Radiographs Are Equivocal

• CT arthrography has the highest sensitivity (nearly 100%), specificity, and accuracy for detecting scapholunate ligament tears and is superior to MR arthrography for detecting partial tears of the biomechanically important dorsal ligament fibers. 3, 4
• MRI (especially 3T) has sensitivities of 65-89% for scapholunate ligament tears and can detect concomitant soft tissue injuries. 3, 4
• High-frequency ultrasound with dynamic "clenched fist" maneuvers has sensitivity of 46-100% and specificity of 92-100% for tears of the dorsal band. 3, 4

Prognosis Based on Injury Timing and Severity

Acute Injuries (Treated Early)

Early recognition and surgical intervention provide the most favorable prognosis. 5 In acute scapholunate ligament injuries treated with open reduction and direct ligament repair:

• 88% of patients achieve excellent or good functional outcomes at mean 32-month follow-up. 1
• Mean Mayo wrist scores average 94.77 for excellent results and 84 for good results. 1
• Grip strength recovers to 93.4% of the unaffected side. 6
• Range of motion achieves 84.3% of flexion and 95.72% of radial deviation compared to the unaffected wrist. 6

Chronic Injuries (Delayed Treatment)

Untreated scapholunate dissociation can lead to disabling wrist pain, reduced mobility, and chronic degenerative arthritis (SLAC wrist). 5 The presence of static malalignment in chronic injuries usually leads to inferior outcomes compared to acute repairs. 7 However, arthroscopic dorsal capsulo-ligamentous repair for chronic reducible injuries (Garcia-Elias stages 2-4) can still achieve:

• Mean post-operative DASH scores of 8.3 (compared to pre-operative 46.04). 6
• Correction of DISI deformity in all cases. 6
• Motion averaging 60-80% of the contralateral side and grip strength 65-90% in various reconstruction techniques. 7

Treatment Algorithm

Conservative Management (Partial Tears or Low-Grade Injuries)

• Avoid complete immobilization beyond 6 weeks to prevent muscular atrophy and joint stiffness. 8
• Apply cryotherapy through a wet towel for 10-minute periods during the acute phase for short-term pain relief. 8
• Activity modification to reduce movements that provoke pain (avoid pushups and axial loading in hyperextension). 8
• Begin gentle range of motion exercises once acute pain subsides (typically after 3-6 weeks). 8
• Progress to isometric exercises before advancing to eccentric strengthening. 8
• Incorporate tensile loading exercises to stimulate collagen production and guide normal alignment of newly formed collagen fibers. 8

Surgical Intervention Indications

Surgical treatment is recommended for optimal results in complete tears and should be considered when:

• Complete scapholunate ligament disruption is confirmed on imaging. 5
• Conservative management fails after 3-6 months of appropriate treatment. 8
• Significant functional limitations persist despite conservative therapy. 8
• Static scapholunate malalignment is present on radiographs. 7

Surgical Techniques

• For acute injuries: Open reduction and direct ligament reinsertion using bone anchors, often augmented with capsulodesis techniques. 1
• For chronic reducible injuries: Arthroscopic dorsal capsulo-ligamentous repair provides reliable results with the advantage of early rehabilitation and prevention of post-operative stiffness. 6

Critical Pitfalls to Avoid

• Never inject corticosteroids directly into the ligament substance, as this may inhibit healing, reduce tensile strength, and potentially predispose to spontaneous rupture. 8
• Do not delay diagnosis—the natural history of untreated scapholunate instability can progress to SLAC wrist, though it remains controversial which injuries will progress. 6, 7
• Avoid prolonged complete immobilization beyond 6 weeks, as this leads to muscular atrophy and joint stiffness. 8
• Standard posteroanterior and lateral radiographs may be inadequate; stress views (radial/ulnar deviation or clenched fist) are needed to reveal joint instability. 5

Follow-Up Protocol

• Regular assessment of pain levels, range of motion, and functional improvement should guide progression of treatment. 8
• Re-evaluation at 3-6 months: If symptoms persist despite appropriate conservative management, reassessment with CT arthrography is warranted to evaluate for progression or associated injuries. 8
• Consider surgical consultation if conservative measures fail to achieve adequate pain relief and functional recovery by 6 months. 8