title: Does combined open and arthroscopic synovectomy for diffuse PVNS of the knee improve recurrence rates?
abstract: BACKGROUND
  Diffuse-type pigmented villonodular synovitis (PVNS) has a high local recurrence rate and as such can lead to erosive destruction of the involved joint. Multiple surgical modalities exist, but it is unknown which technique best minimizes local recurrence and surgical morbidity.
  
  
  OBJECTIVE
  We compared recurrence rates, arthritis progression, and complications between arthroscopic and open modalities for diffuse PVNS of the knee.
  
  
  METHODS
  We retrospectively identified 103 patients with PVNS treated between 1993 and 2011. Of these, 48 had diffuse-type PVNS of the knee treated by all-arthroscopic, open posterior with arthroscopic anterior, or open anterior and open posterior synovectomy. We recorded patient demographics, treatment profiles, recurrence rates, and arthritic progression. Minimum followup was 3 months (median, 40 months; range, 3-187 months).
  
  
  RESULTS
  Recurrence rates were lower in the open/arthroscopic group compared with the arthroscopic or open/open groups: 9% versus 62% versus 64%, respectively. Arthritic progression occurred in 17% of the total study group with 8% going onto total knee arthroplasty within the followup period. We detected no difference between groups with regard to arthritic progression or progression to arthroplasty. The most common complication was hemarthrosis, which we drained in three patients (6% of the total study group), but there were no detectable differences between groups.
  
  
  CONCLUSIONS
  Open posterior with arthroscopic anterior synovectomy is a viable, comprehensive approach to diffuse PVNS of the knee and provides both low recurrence rates and a low postoperative complication profile. Greater numbers of recurrences may be partially explained in the arthroscopic group by technical challenges associated with posterior arthroscopic synovectomy and in the open/open group by selection bias toward more aggressive disease.
  
  
  METHODS
  Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
authors.affiliation: Division of Orthopedic Oncology, Department of Orthopedic Surgery, The University of Pittsburgh, 3471 Fifth Avenue, Pittsburgh, PA 15213, USA. colmanmw@upmc.edu
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Colman
authors.forename: Jason
authors.initials: J
authors.lastname: Ye
authors.forename: Kurt R
authors.initials: KR
authors.lastname: Weiss
authors.forename: Mark A
authors.initials: MA
authors.lastname: Goodman
authors.forename: Richard L
authors.initials: RL
authors.lastname: McGough
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001168:Arthritis / Q000209:etiology / Q000601:surgery; D019645:Arthroplasty, Replacement, Knee; D001182:Arthroscopy / Q000009:adverse effects; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007719:Knee Joint / Q000473:pathology / Q000601:surgery*; D008297:Male; D016016:Proportional Hazards Models; D012008:Recurrence; D012086:Reoperation; D012189:Retrospective Studies; D000074402:Synovectomy; D013583:Synovial Membrane / Q000473:pathology; D013586:Synovitis, Pigmented Villonodular / Q000150:complications / Q000175:diagnosis / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult