Question 1

I'm a 15-year-old netball player and dislocated my kneecap for the first time 3 weeks ago. It went back in on its own when I straightened my leg. My doctor says I should do physiotherapy but some of my teammates who had the same injury needed surgery. How do I know if I need surgery or not?

Accepted Answer

Decision between conservative management and surgery after first-time patellar dislocation depends on anatomical risk factors and your circumstances. Here's how doctors decide: RISK STRATIFICATION: After first dislocation, orthopedic surgeon assesses recurrence risk based on: Age—you're 15, which is high-risk age (adolescents have 40-60% recurrence vs 15-20% in adults). Anatomy—MRI and X-rays show: trochlear dysplasia (shallow groove kneecap sits in—graded A-D, C-D high risk), patella alta (high-riding kneecap—measured on X-ray, high risk if Insall-Salvati ratio more than 1.2), TT-TG distance (lateral pull measurement—more than 20mm high risk), MPFL tear pattern (complete tear vs partial), osteochondral fracture (bone/cartilage fragment—30-40% of first dislocations have this). Contralateral instability—has your other knee ever dislocated? If yes, very high risk. Sport demands—netball involves cutting, pivoting, jumping—high-demand sport. CONSERVATIVE MANAGEMENT CANDIDATES: Good candidates for physiotherapy (60-70% success): mild or no trochlear dysplasia, normal patella height, TT-TG less than 20mm, age more than 18 years, low-demand sports, willing to accept 15-20% recurrence risk. Your age (15) and sport (netball) are AGAINST conservative management, but if your anatomy is normal, may still try physio first. SURGICAL CANDIDATES: Strong indications for surgery after FIRST dislocation: large osteochondral fracture requiring fixation or removal, severe trochlear dysplasia (Grade C-D), patella alta with other risk factors, contralateral knee already unstable, elite athlete needing to return to high-level sport with minimal recurrence risk. Relative indications (could go either way): adolescent age (15 years) + high-demand sport + any anatomical risk factors. DECISION-MAKING: Your doctor likely offered conservative management because: (1) surgery after first dislocation has controversy—studies show conservative vs surgical outcomes similar overall, but subset of high-risk patients do better with early surgery; (2) if you fail conservative management (redislocation during physio), can always do surgery then; (3) avoiding surgery if possible is generally preferable (avoids operative risks). RECOMMENDATION: Start conservative management with physiotherapy for 3-4 months focusing on VMO strengthening. If during this period you have: recurrent subluxation (kneecap feels like it's slipping), apprehension preventing return to netball, or frank redislocation, then proceed to surgery (MPFL reconstruction). If you get through 3-4 months without instability and return to netball successfully, continue conservative approach. However, if MRI shows you have severe anatomical risk factors (ask your doctor to explain your imaging), consider seeking second opinion about early surgical stabilization given your age and sport demands.

Question 2

I've had my kneecap dislocate 5 times over the past 2 years (I'm 22 years old) and my surgeon recommends MPFL reconstruction. However, I'm confused because the surgeon also mentioned something about my 'TT-TG distance being 24mm' and that I might need an additional bone cut (tibial tubercle transfer). This sounds really complicated and risky—do I really need both procedures or is MPFL reconstruction alone enough?

Accepted Answer

Your surgeon is correct to discuss tibial tubercle osteotomy in addition to MPFL reconstruction, and here's why: UNDERSTANDING TT-TG DISTANCE: TT-TG (tibial tubercle-trochlear groove) distance measures the lateral offset between where your patellar tendon attaches to your shin bone (tibial tubercle) and the center of the groove your kneecap sits in (trochlear groove). Normal: less than 20mm. Your measurement: 24mm. This means your patellar tendon pulls your kneecap LATERALLY (outward) by an extra 4mm compared to normal. This creates constant lateral pull that predisposes to dislocation. WHY MPFL ALONE MAY NOT BE ENOUGH: MPFL reconstruction rebuilds the ligament that prevents lateral dislocation, which works well when: anatomy is normal or mildly abnormal (TT-TG less than 20mm), instability is primarily due to MPFL insufficiency. However, with TT-TG more than 20mm: the mechanical lateral pull is so strong that even a reconstructed MPFL may be overwhelmed, studies show MPFL reconstruction alone in high TT-TG patients has: 15-25% failure rate (redislocation), excessive stress on MPFL graft potentially causing it to stretch out or fail. WHY COMBINED SURGERY RECOMMENDED: When TT-TG more than 20mm, most surgeons recommend: MPFL reconstruction (restores medial soft tissue restraint) PLUS tibial tubercle osteotomy (medialization—cuts bone and moves tibial tubercle medially by 10-15mm to reduce lateral pull). Studies show combined surgery has: 85-90% success preventing recurrent dislocation vs 75-80% for MPFL alone in high TT-TG patients. UNDERSTANDING THE RISKS: Yes, tibial tubercle osteotomy adds complexity and risks: longer surgery (2 hours vs 1 hour), bone healing required (6-8 weeks partial weight-bearing vs 4 weeks for MPFL alone), higher complication rates: nonunion 5% (bone doesn't heal), compartment syndrome 1-2% (serious emergency), hardware prominence requiring removal 10-20%, fracture 3-5%. However, these risks must be weighed against: 15-25% risk of MPFL reconstruction alone failing if you don't address the high TT-TG, potentially needing revision surgery if MPFL alone fails (worse outcomes than getting it right first time). RECOMMENDATION: If your TT-TG is truly 24mm (4mm over threshold): Combined MPFL reconstruction + tibial tubercle medialization is appropriate recommendation, especially given you've had 5 dislocations (indicating severe instability). Accepting the added complexity/risks of osteotomy upfront gives you best chance of long-term stability and avoiding revision surgery. Make sure surgery performed by experienced surgeon who routinely does these procedures—this is not a surgery for generalist orthopedic surgeon. ALTERNATIVE: Some surgeons might consider trying MPFL reconstruction alone if you're: very keen to avoid osteotomy, willing to accept slightly higher redislocation risk, young with good tissue quality. However, most surgeons would consider TT-TG 24mm a strong indication for combined procedure. Get clear explanation from your surgeon about their experience with these surgeries and their published outcomes.

Medical Disclaimer

Kneecap Instability (Patellar Dislocation)

📖What is Kneecap Instability (Patellar Dislocation)?

🔬What Causes It?

⚠️Risk Factors

You may be at higher risk if:

🛡️Prevention