Does knee joint proprioception alter following medial patellofemoral ligament reconstruction?
BACKGROUND
This study firstly aimed to determine whether proprioception deficits, as measured by joint position sense (JPS), occur in people following recurrent patellar dislocations. Secondly, to determine whether JPS changes following medial patellofemoral ligament reconstruction (MPFL) reconstruction for patellar instability.


METHODS
Thirty people following recurrent patellar dislocation were recruited. Pre-operative JPS was assessed using the passive angle reproduction test. Through this, an assessor moved a participant's limb to a target position. This was returned to neutral, before finally moving the limb again, whilst requiring the participant to indicate when they thought the target angle was reached. The actual angular error (AAE) was calculated as the difference between the perceived angle and target angle. Clinical outcomes included the Kujala Patellofemoral Disorder Score, the International Knee Documentation Committee (IKDC) form, pain, knee motion, extensor muscle strength and frequency of patellar dislocation. Outcomes were assessed pre-operative, 6 weeks, 3 and 12 months.


RESULTS
Mean AAE was 2.2° (inner range) to 3.9° (mid-range); this was not clinically significant. There was no statistically significant difference between the baseline-and-6 week, 6 week-and-3 month or baseline-and-12 month AAE measures (p=0.38 to 1.00). There was a statistically significant improvement in functional outcomes as measured by the Kujala score, IKDC form, reduced pain and increased extension strength from baseline to 12 months (p<0.01).


CONCLUSIONS
Following recurrent patellar dislocation, patients exhibit minimal deficits in JPS. Whilst MPFL reconstruction significantly improved clinical and functional outcomes for this population, this operation did not significantly alter JPS during the first post-operative year.
Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, UK. Electronic address: toby.smith@uea.ac.uk.
T O
TO
Smith
Institute of Orthopaedics, Norfolk and Norwich University Hospital & Faculty of Medicine and Health Sciences, University of East Anglia, UK.
C J V
CJ
Mann
Institute of Orthopaedics, Norfolk and Norwich University Hospital & Faculty of Medicine and Health Sciences, University of East Anglia, UK.
S T
ST
Donell
D053587:Arthrometry, Articular; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology / Q000601:surgery*; D008023:Ligaments, Articular / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D053580:Muscle Strength / Q000502:physiology; D053581:Muscle Strength Dynamometer; D031222:Patellar Dislocation / Q000503:physiopathology / Q000601:surgery*; D057071:Patellofemoral Joint / Q000503:physiopathology / Q000601:surgery*; D011184:Postoperative Period; D057234:Preoperative Period; D011434:Proprioception / Q000502:physiology*; D012008:Recurrence; D013710:Tendons / Q000637:transplantation; D064232:Visual Analog Scale; D055815:Young Adult