title: [Impact of Preoperative Knee Stiffness on the Postoperative Outcome after Total Knee Arthroplasty in Patients with Haemophilia].
abstract: BACKGROUND
  Total knee arthroplasty (TKA) is an effective treatment option for patients with end-stage haemophilic arthropathy of the knee. However, the procedure is technically challenging, as knee motion is often restricted before the operation and complication rates are then thought to be higher than for patients with a normal range of motion (ROM). There is very limited information on the outcome of TKA in haemophilic patients presenting with stiff knees. The objective of the present study was to retrospectively analyse and compare the clinical results after TKA in haemophiliacs with stiff and non-stiff knees.
  
  
  METHODS
  The results of 50 TKA procedures in 41 haemophilic patients were retrospectively evaluated at a mean follow-up of 7.2 ± 4.9 years (range 2-25 years). 20 patients presenting with 23 stiff knees - defined by a preoperative ROM of 50° or less - were compared with 21 patients with 27 non-stiff knees. Knee motion (ROM, flexion, extension), Knee Society Score (KSS/KSS function), pain status (visual analogue scale, VAS), number of bleedings and patient satisfaction were evaluated.
  
  
  RESULTS
  The complication rate was 12 %, including two haematomas, one aseptic loosening, and three periprosthetic infections. The overall mean ROM increased from 58.6 ± 34.2° (range 0-120°) preoperatively to 85.9 ± 23.4 (35-130°) postoperatively (p < 0.005). Mean KSS and KSS function improved from 30.6 ± 11.0 points (range 10-49) and 43.4 ± 9.3 points (range 15-65) to 79.3 ± 9.6 points (range 49-95) and 68.9 ± 11.0 points (45-90), respectively (p < 0.005). The mean VAS score decreased significantly from 7.9 ± 0.8 points (range 6-9) to 1.8 ± 1.1 points (range 0-4; p < 0.005). In comparison to the non-stiff group, patients with stiff knees showed a significantly greater mean improvement in ROM (46.3 ± 21.8° [range - 10-85°] vs. 9.4 ± 16.9° [range - 30-35°]), flexion (32.8 ± 19.6° [range - 10-85°] vs. 5.2 ± 16.2° [range - 40-35°]), and flexion contracture (13.5 ± 9.6° [range 5-30°] vs. 5.9 ± 6.7° [range 5-20°]). Both KSS and KSS function were significantly inferior in stiff knees than with non-stiff knees. Nine patients with knee stiffness who underwent additional v-y quadricepsplasty to lengthen the extensor mechanism developed a mean extensor lag of 7-0° ± 4-8° (range 5-15°). At final follow-up, 37/41 patients were satisfied or very satisfied with the surgical result.
  
  
  CONCLUSIONS
  TKA in haemophilic patients presenting with haemophilic arthropathy of the knee results in significant improvements in function and reduced pain. Although the ultimate clinical outcome in stiff knees is inferior to that with non-stiff knees, joint replacement surgery can be successfully performed in patients with restricted preoperative range of motion. Vy-quadricepsplasty for to facilitate exposure is associated with the development of a postoperative extensor lag and should therefore be performed restrictively. Patient satisfaction after TKA was equally high in the two groups.
authors.affiliation: Klinik und Poliklinik für Orthopädie und Unfallchirurgie, Universitätsklinikum Bonn.
authors.forename: A C
authors.initials: AC
authors.lastname: Strauss
authors.affiliation: Institut für Experimentelle Hämatologie und Transfusionsmedizin, Universitätsklinikum Bonn.
authors.forename: G
authors.initials: G
authors.lastname: Goldmann
authors.affiliation: Klinik und Poliklinik für Orthopädie und Unfallchirurgie, Universitätsklinikum Bonn.
authors.forename: J
authors.initials: J
authors.lastname: Schmolders
authors.affiliation: Klinik und Poliklinik für Orthopädie und Unfallchirurgie, Universitätsklinikum Bonn.
authors.forename: M C
authors.initials: MC
authors.lastname: Müller
authors.affiliation: Klinik und Poliklinik für Orthopädie und Unfallchirurgie, Universitätsklinikum Bonn.
authors.forename: R
authors.initials: R
authors.lastname: Placzek
authors.affiliation: Institut für Experimentelle Hämatologie und Transfusionsmedizin, Universitätsklinikum Bonn.
authors.forename: J
authors.initials: J
authors.lastname: Oldenburg
authors.affiliation: Klinik und Poliklinik für Orthopädie und Unfallchirurgie, Universitätsklinikum Bonn.
authors.forename: D C
authors.initials: DC
authors.lastname: Wirtz
authors.affiliation: Klinik und Poliklinik für Orthopädie und Unfallchirurgie, Universitätsklinikum Bonn.
authors.forename: P H
authors.initials: PH
authors.lastname: Pennekamp
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000706:statistics & numerical data*; D015897:Comorbidity; D005260:Female; D005858:Germany / Q000453:epidemiology; D006467:Hemophilia A / Q000175:diagnosis / Q000453:epidemiology*; D006801:Humans; D007593:Joint Instability / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000453:epidemiology*; D015995:Prevalence; D011379:Prognosis; D016059:Range of Motion, Articular; D020127:Recovery of Function; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome