title: Early outcome after total knee replacement using computed tomography-based patient-specific cutting blocks versus standard instrumentation.
abstract: OBJECTIVE
  To compare early outcome of total knee replacement (TKR) using computed tomography (CT)-based patient-specific cutting blocks versus standard instrumentation.
  
  
  METHODS
  40 men and 44 women (90 knees) aged 45 to 88 (mean, 65) years who underwent TKR using standard instrumentation were compared with 39 men and 43 women (90 knees) aged 44 to 85 (mean, 64) years who underwent TKR using CT-based patient-specific cutting blocks. A single surgeon performed all TKRs through the medial parapatellar approach using a cemented prosthesis, with the posterior cruciate ligament retained and the patella resurfaced.
  
  
  RESULTS
  Respectively in the standard and patient-specific instrumentation groups, 74 and 70 patients were followed up for a mean of 30 and 14 months. The mean Oxford Knee Score was 19 and 19 preoperatively, 34 and 34 at 3 months, and 37 and 40 at 12 months (p=0.02). 71% and 88% of patients achieved good-to-excellent outcome (Oxford Knee Score of >34) at 12 months (p=0.008). The respective mean EQ-5D score was 54 and 52 preoperatively, 73 and 76 at 3 months, and 77 and 78 at 12 months. 18% and 2% of patients required a blood transfusion (p=0.0002), with a mean blood loss of 292 and 254 g/l (p=0.049). The mean tourniquet time was 45 minutes in both groups. There was no infection or revision in either group.
  
  
  CONCLUSIONS
  Compared with standard instrumentation, the use of CT-based patient-specific cutting blocks for TKR achieved higher Oxford Knee Score at 12 months and lower blood loss and transfusion rate.
authors: Sydney Bone and Joint Clinic, Sydney, Australia.
authors: Arash
authors: A
authors: Nabavi
authors: Caroline M
authors: CM
authors: Olwill
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation*; D005260:Female; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000601:surgery*; D010329:Patella / Q000000981:diagnostic imaging / Q000601:surgery*; D011474:Prosthesis Design; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome
keywords: arthroplasty, replacement, knee; computed tomography