title: Nail-patella-syndrome in a young patient followed up over 10 years: relevance of the sagittal trochlear septum for patellofemoral pathology.
abstract: BACKGROUND
  Nail-patella-syndrome (NPS) is a rare autosomal-dominant inherited disease with pathologies of nails, skeleton, kidneys, and eyes. Linkage to a mutated gene was found. It codes for the transcription-factor LMX1B. In most cases knees are symptomatic. Patients have hypoplastic patellae, which are laterally subluxated. In those individuals a sagittal trochlear fibrous septum was found, dividing the anterior knee-joint-space. In the literature the etiology and clinical significance of this anatomic abnormality is unclear. Based on clinical and intraoperative findings we developed a theory regarding knee pathology in nail-patella-syndrome. Successful treatment via early resection of the septum with sustained good outcome is presented.
  
  
  METHODS
  In a symptomatic six-year-old boy with nail-patella-syndrome we resected the fibrous sagittal septum adherent to the trochlea femoris and we balanced the patella via lateral release and medial plication in both knee joints. We analyzed the clinical outcome of this procedure prospectively over 10 years.
  
  
  RESULTS
  Postoperatively the hypoplastic patellae stayed centered and stable during further skeletal development. The patient was still pain free with normal range of motion of both operated knee joints after 10 years of follow-up.
  
  
  CONCLUSIONS
  In patients with nail-patella-syndrome and a subluxated or dislocated patella we recommend diagnostics with magnetic-resonance-imaging and early surgical treatment via resection of the trochlear septum and soft-tissue-balancing of the patella. When the septum displaces the patella and prevents physiological articulation of the patella with the trochlea femoris, early septum resection is likely to be important for a good functional outcome and proper development of the patellofemoral joint during growth.
authors.affiliation: Department of Orthopaedic Surgery, Koenig-Ludwig-Haus, Julius-Maximilians-University Wuerzburg, Brettreichstr. 11, 97074 Wuerzburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Konrads
authors.affiliation: Department of Orthopaedic Surgery, Koenig-Ludwig-Haus, Julius-Maximilians-University Wuerzburg, Brettreichstr. 11, 97074 Wuerzburg, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Reppenhagen
authors.affiliation: Department of Orthopaedic Surgery, Koenig-Ludwig-Haus, Julius-Maximilians-University Wuerzburg, Brettreichstr. 11, 97074 Wuerzburg, Germany.
authors.forename: Piet
authors.initials: P
authors.lastname: Plumhoff
authors.affiliation: Department of Orthopaedic Surgery, Koenig-Ludwig-Haus, Julius-Maximilians-University Wuerzburg, Brettreichstr. 11, 97074 Wuerzburg, Germany.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Rudert
authors.affiliation: Department of Orthopaedic Surgery, Koenig-Ludwig-Haus, Julius-Maximilians-University Wuerzburg, Brettreichstr. 11, 97074 Wuerzburg, Germany.
authors.forename: Andre
authors.initials: A
authors.lastname: Steinert
authors.affiliation: Department of Orthopaedic Surgery, Koenig-Ludwig-Haus, Julius-Maximilians-University Wuerzburg, Brettreichstr. 11, 97074 Wuerzburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Barthel