Open vs. Arthroscopic Fixation of Patellar OCD with MPFL Reconstruction
For an 18-year-old male with first-time patellar dislocation and a large osteochondral fragment of the medial patellar facet requiring MPFL reconstruction, open fixation of the osteochondral defect is strongly recommended over arthroscopic fixation to ensure optimal visualization, rigid fixation, and fragment viability assessment.
Primary Recommendation
Open fixation should be performed when the osteochondral fragment is ≥1 cm² in the patellofemoral contact area, as this approach allows superior visualization of the fragment's undersurface, more secure fixation with screws or bioabsorbable implants, and better assessment of cartilage viability 1, 2.
Decision Algorithm for Surgical Approach
Fragment Size and Location Considerations
Fragments ≥1 cm² in the patellofemoral contact area mandate surgical fixation rather than removal, as fragment refixation or cartilage restoration techniques are strongly preferred over debridement to preserve joint surface integrity and prevent early-onset osteoarthritis 1.
Large fragments involving the medial patellar facet with substantial bone involvement require open approach because arthroscopic techniques provide inadequate visualization of the fragment's undersurface and limited ability to achieve rigid compression fixation 2, 3.
Technical Advantages of Open Fixation
Open arthrotomy allows direct visualization of the entire osteochondral fragment, enabling assessment of cartilage viability, debridement of friable edges to obtain stable healthy cartilage margins, and precise anatomic reduction of the fragment 4.
Rigid internal fixation with compression screws or bioabsorbable pins is more reliably achieved through open approach, particularly for fragments with significant subchondral bone that require penetration into stable bone for secure fixation 4.
The open approach permits thorough irrigation of the defect bed and removal of any interposed soft tissue or debris that could compromise fragment healing, which is difficult to accomplish arthroscopically 4.
Integration with MPFL Reconstruction
MPFL reconstruction should be performed during the same surgical session as osteochondral fragment fixation to address both the acute injury and the underlying instability mechanism, reducing recurrence risk from 17-49% with conservative treatment to approximately 5% with surgical stabilization 5, 1.
The open approach for fragment fixation does not preclude arthroscopic MPFL reconstruction, as the medial arthrotomy for patellar access can be performed through a separate incision from the MPFL femoral and patellar tunnels 2, 6.
Anatomical MPFL reconstruction using autograft or allograft is preferred over primary repair, as reconstruction provides superior biomechanical stability and lower redislocation rates compared to simple suture repair of the torn ligament 5, 1.
Critical Timing Considerations
Immediate surgical intervention is indicated when osteochondral fractures are present, rather than delayed repair, as early fixation (within 2-3 weeks) maximizes fragment viability and healing potential 1, 3.
Fragment removal should be avoided even if immediate surgery cannot be performed, as delayed open reduction and internal fixation is still preferred over excision to preserve articular cartilage 1.
Common Pitfalls to Avoid
Arthroscopic fixation of large patellar osteochondral fragments frequently fails due to inadequate visualization and inability to achieve rigid compression, leading to fragment nonunion, displacement, or conversion to loose body formation 2, 3.
Attempting arthroscopic fixation in an 18-year-old with substantial bone involvement risks growth plate injury if drilling is not precisely controlled under direct vision, though this patient is likely skeletally mature 2.
Failure to address the MPFL tear during osteochondral fragment fixation leaves the patient at high risk for recurrent instability, which can compromise the healing fragment through repetitive abnormal loading 5, 6.
Postoperative Management Requirements
Protected weight-bearing for 6-8 weeks is mandatory following osteochondral fragment fixation to allow bone-to-bone healing and cartilage integration, with progressive range of motion initiated immediately to prevent arthrofibrosis 7, 8.
Serial radiographic follow-up at 6 weeks, 3 months, and 6 months is essential to monitor fragment incorporation, assess for displacement or hardware complications, and detect early signs of articular surface collapse 7.