- 18 year old male presented with instability of left knee cap for 4 years with patellar dislocation on extension. Examination found ligamentous laxity, genu valgum, and Marfanoid habitus. The patella dislocated laterally with every range of motion cycle and relocated at flexion over 30 degrees. Imaging found an Insall-Salvati ratio of 1.3, indicating patella alta. The plan was to isolate the patellar tendon, guide saw cuts with K-wires, mobilize and shingle the tuberosity medially, provisionally fix with K-wires, fix with two screws, perform a lateral release, and reconstruct the MPFL.

1. Case discussion

2. • 18 yr old male
• C/o instability of left knee cap since 4 years
• Patellar dislocation on extension
• No history of locking and clicking

4. On general examination
• Ligamentous laxity +
• Genu valgum +
• Marfanoid habitus

5. Local examination
• Dislocates laterally in every ROM cycle of knee
• Dislocates during extension, relocates at flexion
more than 30 degrees
• Q angle – 20 degrees
• Thigh foot angle –
• ? Patella alta

6. Insall Salvatti
Index(A/B) = 1.3
(0.8 – 1.2)
A
B

11. PLAN

12. ISOLATE BOTH SIDES OF PATELLAR TENDON

13. TANGENTIAL K WIRES TO TIBIAL SURFACE TO
GUIDE SAW CUT

14. TUBEROSITY AFTER CUT

15. MOBILISED PATELLAR TENDON

16. SHINGELLING TO PREPARE TUBEROSITY BED
MEDIALLY

17. MOBILSE TUBEROSITY MEDIALLY

18. K WIRES FOR PROVISIONAL FIXATION

19. FIXED WITH 2 SCREWS

20. NEXT IS LATERAL RELEASE

21. MPFL RECONSTRUCTION

22. FINAL RESULT