Management of Nondisplaced Fracture Through a Bony Spur at Quadriceps Tendon Insertion
Conservative management with immobilization is the appropriate treatment for nondisplaced fractures at the quadriceps tendon insertion site, provided the extensor mechanism remains intact and functional. 1
Initial Assessment and Treatment Decision
The critical determinant for management is extensor mechanism function, not simply fracture displacement:
- If the patient can actively extend the knee against gravity with a straight leg raise, the extensor mechanism is intact and conservative treatment is indicated 2
- If there is any extensor lag or inability to maintain active extension, this represents a complete functional disruption requiring surgical repair regardless of radiographic appearance 2, 3
Conservative Management Protocol
For truly nondisplaced fractures with intact extensor mechanism:
- Immobilize in a hinged knee brace or cylinder cast in full extension for 3-6 weeks 2, 3
- Non-weight bearing or protected weight bearing initially, progressing as tolerated 3
- Serial radiographs at 7-10 days to confirm maintained alignment 1
- Begin gentle range of motion exercises after 3-4 weeks of immobilization, advancing cautiously 3
Surgical Indications (Critical Pitfalls to Avoid)
Do not be falsely reassured by "nondisplaced" radiographic appearance. Several scenarios mandate surgical intervention:
- Any extensor lag or inability to perform straight leg raise indicates complete functional rupture requiring immediate surgical repair 2, 3
- Fracture fragment involving >1/3 of the articular surface requires operative fixation 4
- Palmar (anterior) displacement of fragments or interfragmentary gap >3mm indicates instability requiring surgery 4
- Progressive displacement on follow-up radiographs necessitates conversion to surgical management 1
Secondary Fracture Prevention
For patients ≥50 years with this fragility fracture pattern:
- Systematically evaluate for osteoporosis risk with bone density assessment 5
- Initiate pharmacological treatment with bisphosphonates (alendronate or risedronate as first-line) for high-risk patients 5
- Ensure adequate calcium and vitamin D supplementation 5
Expected Outcomes
With appropriate conservative management of truly nondisplaced fractures:
- >90% of patients return to pre-injury function when treated appropriately 2, 3
- Quadriceps atrophy is common (present in most cases) but does not preclude good functional outcomes 3
- Re-rupture rate is approximately 2% with proper treatment 3
Key Clinical Caveat
The most common error is misclassifying a complete functional rupture as "nondisplaced" based solely on radiographic appearance. Always perform a functional assessment of the extensor mechanism before committing to conservative treatment. Delayed surgical repair (>6 weeks) results in significantly worse outcomes, higher complication rates, and often requires complex reconstruction rather than simple repair 2, 3, 6.