Patellar tracking and anterior knee pain are similar after medial parapatellar and midvastus approaches in minimally invasive TKA.
BACKGROUND
Since the medial parapatellar (MPP) approach in conventional TKA can cause patellar maltracking and anterior knee pain, some orthopaedic surgeons use the midvastus (MV) approach instead of the MPP approach to reduce patellar maltracking. Minimally invasive surgical (MIS) TKA has been developed to limit the damage to the surrounding muscle and reduce the necessity of patellar eversion during surgery. Thus, MIS TKA might be associated with proper patellar tracking and a low incidence of anterior knee pain. However, this presumption has not been confirmed.


OBJECTIVE
We asked whether the incidence of patellar maltracking and anterior knee pain differed with the MV and MPP in association with MIS TKA.


METHODS
We prospectively followed 59 patients (60 knees) treated with 60 primary cemented MIS TKAs from August 2009 to September 2010. We randomized the patients into two groups: 30 who had a limited MPP approach and 30 who had a mini-MV approach. We recorded the occurrence of anterior knee pain, patellar tilting, and subluxation. The minimum followup was 12 months (mean, 18.03 months; range, 12.00-25.08 months).


RESULTS
We found no differences in anterior knee pain (two of 30, 7% versus two of 30, 7%), mean patellar tilt (3.4º ± 2.9º versus 3.0 ± 2.3º), and mean patellar subluxation (1.5 ± 1.1 mm versus 1.1 ± 0.7 mm) between the limited MPP and mini-MV groups, respectively.


CONCLUSIONS
MIS TKA using either the MPP or MV approach has a low incidence of patellar maltracking and anterior knee pain.
Boonchana
B
Pongcharoen
Department of Orthopaedic Surgery, Faculty of Medicine, Thammasat University Thailand, 95 moo8 Klong, Klongluang, Patumthani, 12120, Thailand. boonbigbear@hotmail.com
Boonchna
B
Pongcharoen
Thanasak
T
Yakampor
Keerati
K
Charoencholvanish
D000368:Aged; D018771:Arthralgia / Q000175:diagnosis / Q000453:epidemiology*; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects* / Q000379:methods; D001696:Biomechanical Phenomena; D001843:Bone Cements / Q000627:therapeutic use; D016009:Chi-Square Distribution; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007719:Knee Joint / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D010149:Postoperative Pain / Q000175:diagnosis / Q000453:epidemiology*; D010329:Patella / Q000503:physiopathology*; D011446:Prospective Studies; D016059:Range of Motion, Articular; D013785:Thailand; D016896:Treatment Outcome
D001843:Bone Cements