Case 05 Flashcards
(7 cards)
Patient is a 15-year-old recreationally active female who sustained an isolated acute traumatic patellar dislocation in gym. She is treated conservatively for the first 2 months with a brace and activity modification.
She had persistent knee pain instability so she was prescribed physical therapy by a surgeon in the group. She had persistent pain, feelings of instability and not able to participate in gym so she referred to me at 5 months status post primary dislocation for surgical evaluation.
She is otherwise healthy no previous knee problems recreationally active.
Physical examination was consistent for tenderness palpation over the MPFL at the patella. She had apprehension with lateral translation, grade 2, negative J sign and normal range of motion and strength assessment.
Xray images were notable for No excessive increase in the patellar height ratio (Caton-Deschamps index <1.2 or Insall-Salvati index <1.4), no significant patella tilt.
Normal trochlear groove, abnormal mpfl on the patella originNormal TTTG
Surgical Decision making
Surgical decision-making was complex. She had TTTG distance of less than 20mm. Traumatic etiology with recurrent subluxation and instability but without recurrent dislocation. 15 years old with closed growth plates.
We discussed surgical treatment options to include a diagnostic arthroscopy, open MPFL repair, open MPFL reconstruction with autograft versus allograft, or anterior medialization.
We elected to perform an MPFL repair with was the least invasive compared to the other surgeries and we are excepting of a higher failure rate.
My traditional decision making would be to perform a diagnostic arthroscopy and potential MPFL repair if the patient has a loose body and significant instability in the first 4 to 6 weeks. If patient has recurrent traumatic instability over 3 months or 6 or so I would consider MPFL with allograft reconstruction in the setting of normal TT TG. There is an abnormal TT TG and this is a chronic instability with minimal trauma I would consider an AMZ. In the setting of the patient’s is atypical as this is a relatively acute traumatic recurrent instability without a loose body, likely MPFL tear off of the patella, and the patient and mother wanted to perform the least invasive procedures possible despite an increased risk of failure in the setting of failure of conservative measures.
Again consider physical therapy, bracing, taping; all of which she had already failed.
Intra-operative findings
Patient demonstrated significant lateral translation under anesthesia, greater than grade 2. Abnormal compared to contralateral normal knee. Intraoperatively I was able to identify a defect of the MFPL on the patella origin both arthroscopically and with direct palpation. Normal cartilage.
Repair Technique
I then debrided the medial aspect of the superior patella made an incision to fully release the MPFL and then did a pants over vest plication/imbrication of the MPFL to the periosteum of the patella. I used nonabsorbable FiberWire x2 and a Mason-Allen type stitch configuration to ensure overall MPFL repair integrity. I then used a #2 Vicryl to close over the repair. At the completion of the repair there was grade 1 translation with a firm endpoint of the patella. I do this at the 930 and 1130 position on the patella.
I then track the patella through knee flexion to ensure isometric tensioning at not overtightening.
Arthroscopically, she did not need a cartilage biopsy as her knee cartilage was normal.
I then completed the diagnostic arthroscopy without any additional pathology identified. Duration of surgery was 55 minutes with 15cc estimated blood loss.
Post-operative
Patient was discharged with multimodal pain meds, limited narcotics, aspirin and ice/crutches, WBAT, Bledsoe brace with knee locked from 0-15. MPFL reconstruction protocol.
Patient general postop course was uncomplicated. I saw her at 2 weeks and 6 weeks; 3 months visit was via telemedicine for covid.
