Minimally invasive medial patellofemoral ligament reconstruction for patellar instability using an artificial ligament: A two year follow-up.
BACKGROUND
Recurrence of acute patellar dislocation affects approximately 30% of individuals, and up to 75% of those with grade IV instability. The medial patellofemoral ligament (MPFL) is considered to be critical for patellar stabilization. MPFL reconstruction with allografts has been proposed to reduce risk of recurrence, but there is limited evidence about the safety and effectiveness of techniques using synthetic allografts.


METHODS
We present a retrospective case series of 29 individuals who underwent a MPFL reconstruction between 2009 and 2012, using an artificial ligament for patellar instability by a single surgeon. Clinical, radiological and functional outcomes were measured at a minimum of 24 months.


RESULTS
31 knees (29 individuals) were followed up for a median of 43 (range: 24-68) months. Using the Crosby and Insall grading system, 21 (68%) were graded as excellent, nine (29%) were good, one (3%) as fair and none as worse at 24 months. The mean improvement in Lysholm knee score for knee instability was 68 points (standard deviation 10). Ligamentous laxity was seen in 17 (55%) of individuals. In this subset, 12 were graded as excellent, four as good and one as fair. The mean improvement in patellar height was 11% at three months follow-up. All knees had a stable graft fixation with one re-dislocation following trauma.


CONCLUSIONS
We propose a minimally invasive technique to reconstruct the MPFL using an artificial ligament allowing early mobilization without bracing. This study indicates the procedure is safe, with a low risk of re-dislocation in all grades of instability.


METHODS
Level IV Case Series.
School of Medicine, University of Notre Dame Australia; Norwest Private Hospital, Australia. Electronic address: aditya.khemka1@my.nd.edu.au.
Aditya
A
Khemka
School of Medicine, University of Notre Dame Australia; National Health and Medical Research Council (NHMRC) Clinical Trials Centre, The University of Sydney, Australia. Electronic address: sally.lord@nd.edu.au.
Sarah J
SJ
Lord
Rural Clinical School, University of Notre Dame Australia, Australia. Electronic address: zelda.doyle@nd.edu.au.
Zelda
Z
Doyle
Rural Clinical School, University of Notre Dame Australia, Australia. Electronic address: belindabosley@gmail.com.
Belinda
B
Bosley
School of Medicine, University of Notre Dame Australia; Norwest Private Hospital, Australia; The Australian School of Advanced Medicine, Macquarie University, Australia. Electronic address: munjed@me.com.
Munjed
M
Al Muderis
D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007593:Joint Instability / Q000175:diagnosis / Q000209:etiology / Q000601:surgery*; D008297:Male; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D031222:Patellar Dislocation / Q000150:complications / Q000175:diagnosis / Q000601:surgery*; D057071:Patellofemoral Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D019736:Prostheses and Implants; D019919:Prosthesis Implantation / Q000379:methods*; D019651:Plastic Surgery Procedures / Q000379:methods*; D012008:Recurrence; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
Artificial ligament; Medial patellofemoral ligament; No bracing; Patella; Reconstruction