title: Comparison of lateral release versus lateral release with medial soft-tissue realignment for the treatment of recurrent patellar instability: a systematic review.
abstract: OBJECTIVE
  The purpose of this report is to present a systematic review of the literature to compare surgical success of lateral retinacular release (LRR) or LRR with medial soft-tissue realignment (MR) for recurrent lateral patellar instability.
  
  
  METHODS
  We searched MEDLINE and PubMed databases for all English-language studies reporting surgical management of recurrent lateral patellar instability with LRR or with LRR and MR. Exclusion criteria included a minimum follow-up <2 years, mean age <18 years old, bony realignment procedures, surgical treatment of an initial patellar instability episode, or surgical treatment of patellofemoral pain without instability. Surgical failure was defined as an episode of patellar dislocation or subluxation during the postoperative period. Statistical analysis compared the failure rate of LRR versus combined LRR with MR by using a Fisher exact test and assessed for publication bias.
  
  
  RESULTS
  Fourteen studies met inclusion criteria. There were 247 knees with a minimum 2-year follow-up after LRR and 220 after LRR with MR. In the LRR patients, there were 56 cases (probability 0.227, odds 0.293) of recurrent lateral patellar instability, 26 of which were postoperative patellar dislocations. In the LRR with MR patients, there were 14 cases (probability 0.064, odds 0.068) of recurrent instability, 12 of which were dislocations. The frequency-weighted mean success with respect to instability in the LRR studies was 77.3% compared with 93.6% in the LRR with MR studies. The odds of subsequent instability after LRR were significantly greater than after LRR with MR with respect to any postoperative instability (P < .001), recurrent dislocation (P = .045), and recurrent subluxation (P < .001).
  
  
  CONCLUSIONS
  This systematic review found that isolated LRR yields significantly inferior long-term results with respect to symptoms of recurrent lateral patellar instability compared with LRR with MR.
  
  
  METHODS
  Level III, systematic review of level III and IV studies.
authors.affiliation: Department of Orthopaedic Surgery, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA.
authors.forename: Eric T
authors.initials: ET
authors.lastname: Ricchetti
authors.forename: Samir
authors.initials: S
authors.lastname: Mehta
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Sennett
authors.forename: G Russell
authors.initials: GR
authors.lastname: Huffman
mesh_terms: D000328:Adult; D001182:Arthroscopy / Q000379:methods*; D006801:Humans; D007593:Joint Instability / Q000601:surgery*; D007717:Knee / Q000601:surgery*; D016017:Odds Ratio; D012008:Recurrence; D016896:Treatment Outcome