Why is PRP (Platelet Rich Plasma) therapy not effective for scapholunate ligament tears?

Why PRP Cannot Effectively Treat Scapholunate Ligament Tears

PRP therapy is not recommended for scapholunate ligament tears because ligaments are poorly vascularized structures with limited healing capacity, and the International Society on Thrombosis and Haemostasis has determined there is insufficient evidence to support PRP use for ligament injuries, rating it as "uncertain" with expert consensus scores of only 5.5 out of 9. 1

Fundamental Biological Limitations

Poor Vascularity of Intrinsic Wrist Ligaments

• The scapholunate ligament is an intrinsic carpal ligament with inherently poor blood supply, which fundamentally limits any regenerative therapy's ability to deliver growth factors to the injury site 1
• PRP's mechanism relies on delivering growth factors that promote angiogenesis (new blood vessel formation), cell migration, and collagen deposition—but these processes require adequate baseline vascularity to be effective 2
• Without sufficient vascular access, the platelet-derived growth factors cannot reach target cells or stimulate the necessary cellular responses for tissue repair 1

Structural Complexity of the Scapholunate Ligament

• The scapholunate ligament has a complex three-part structure (dorsal, proximal, and volar bands) with the dorsal band being the most critical for stability 1
• Complete tears result in carpal instability and altered wrist kinematics that cannot be addressed by growth factor delivery alone—they require mechanical stabilization 3
• Even partial tears (Geissler type II-III) in young athletes require surgical intervention with capsuloplasty techniques to restore stability, not just biological healing 4, 5

Critical Evidence Gaps and Standardization Problems

Lack of High-Quality Evidence for Ligament Injuries

• A 2011 systematic review found no randomized controlled trials demonstrating scientific evidence of PRP efficacy for ligament injuries, with only small case series and animal studies available 6
• The International Society on Thrombosis and Haemostasis expert panel could not recommend PRP for tendon or ligament injuries due to insufficient data, rating both as "uncertain" 1
• For osteoarthritis (a more vascularized condition than ligament tears), the 2020 VA/DoD guidelines found mixed results and could not recommend for or against PRP use 1

Severe Lack of Standardization

• PRP preparations vary wildly in platelet concentration, purity, leukocyte content, activation status, and growth factor composition—making it impossible to determine what "works" even if some benefit existed 1
• Clinical trials have been conducted without clear definition or quantification of PRP biological properties, leading to unreliable and inconsistent outcomes 1
• Critical variables remain undetermined: optimal volume, preparation method, activation technique, injection timing, single versus multiple applications, and post-injection rehabilitation protocols 6

Clinical Management Algorithm for Scapholunate Ligament Tears

Acute Tears (Within 6 Weeks)

• Obtain radiographs in neutral, clenched fist, and stress views looking for scapholunate diastasis >4mm or dorsal intercalated segmental instability 1
• If radiographs show instability: proceed directly to surgical repair/reconstruction—do not attempt PRP 3
• If radiographs are normal but high clinical suspicion: obtain CT arthrography (nearly 100% sensitivity and specificity) or 3T MRI 1

Chronic Partial Tears (Geissler II-III)

• Young athletes with persistent pain after 6 months of conservative management require arthroscopic evaluation and débridement with capsuloplasty 4, 5
• Modified Viegas dorsal capsuloplasty allows return to competitive sports within 4-12 months in young athletes 5
• PRP has no role in this population—mechanical stabilization is required 3, 5

Complete Tears with Instability

• These progress to scapholunate advanced collapse (SLAC wrist) if untreated 3
• Require acute ligament repair or reconstruction with capsulodesis techniques 3
• PRP cannot restore mechanical stability or prevent progressive arthritis 3

Key Clinical Pitfalls

Common mistake: Attempting PRP injection for scapholunate tears based on marketing claims or patient requests, which delays definitive surgical treatment and allows progression to irreversible carpal instability 3

Critical caveat: Even in conditions with better vascularity (like knee osteoarthritis), PRP evidence remains inconsistent and insufficient for guideline recommendations 1

Important distinction: PRP may have a role in general wound healing where tissue is well-vascularized, but intrinsic wrist ligaments represent a fundamentally different biological environment 1, 7