title: Knee temperatures measured in vivo after arthroscopic ACL reconstruction followed by cryotherapy with gel-packs or computer controlled heat extraction.
abstract: OBJECTIVE
  To obtain in vivo data about intra- and extra-articular knee temperatures to assess the effectiveness of two cryotherapeutic methods-conventional cooling with gel-packs and computer controlled cryotherapy following anterior cruciate ligament (ACL) reconstructive surgery.
  
  
  METHODS
  Twenty patients were arbitrarily assigned for cryotherapy after ACL reconstruction: 8 patients with frozen gel-packs and 12 patients with computer controlled cryotherapy with constant temperatures of the cooling liquid in the knee pads. The treatment was performed for 12 h. Temperatures were measured with two thermo sensors in catheters placed intraarticularly and subcutaneously, four sensors on the skin and one sensor under protective bandage, every second for 16 h after surgery.
  
  
  RESULTS
  In the first 2 h of treatment, there were no significant differences (n.s.) between the groups in temperatures in the intracondylar notch. After 4 h of cryotherapy, the temperatures were significantly lower on the skin (24.6 ± 2.8 and 31.4 ± 1.3 °C, p < 0.01) and in the subcutaneous tissue (28.6 ± 5.7 and 34.6 ± 1.4 °C, p = 0.01), and the difference between the temperature in the intracondylar notch and the subcutaneous tissue was significantly greater (4.0 ± 3.0 and 0.8 ± 0.6 °C, p = 0.01) in the computer controlled cryotherapy group compared to the gel-pack group.
  
  
  CONCLUSIONS
  The cooling effect of the arthroscopy irrigation fluid on the knee temperature is evident in the first 2 h of treatment. The energy extraction is significantly more effective and controllable by computer controlled cryotherapy than with frozen gel-packs.
  
  
  METHODS
  Prospective comparative study, Level II.
authors.affiliation: Department of Communication Systems, Jožef Stefan Institute, Jamova 39, 1000, Ljubljana, Slovenia.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Rashkovska
authors.forename: Roman
authors.initials: R
authors.lastname: Trobec
authors.forename: Viktor
authors.initials: V
authors.lastname: Avbelj
authors.forename: Matjaž
authors.initials: M
authors.lastname: Veselko
mesh_terms: D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D001831:Body Temperature; D002404:Catheterization; D017679:Cryotherapy / Q000379:methods*; D005260:Female; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods; D007719:Knee Joint / Q000503:physiopathology* / Q000601:surgery*; D008297:Male; D011446:Prospective Studies; D013821:Thermometers; D055815:Young Adult