[Intra-articular analgesia after anterior cruciate ligament reconstruction]

In this double-blind prospective study, pain after reconstruction of the anterior cruciate ligament (ACL) was evaluated using the visual analogue scale (VAS). Comparisons were made between patients administered an intra-articular analgesic mixture of adrenaline, morphine and bupivacaine (Marcaine) and those without it, between patients surgically treated by the BTB technique and those undergoing hamstring tendon ACL reconstruction, and between men and women undergoing the same procedure.

Eighty-five randomly selected patients were allocated by five groups according to the surgery performed: 1. ACL reconstruction by the BTB technique, without administration of the analgesic mixture (20 patients); 2. hamstring tendon ACL reconstruction, without the analgesic mixture (20 patients); 3. ACL BTB technique with intra-operative, intra-articular analgesia (20 patients); 4. hamstring tendon ACL reconstruction, with intra-operative, intra-articular analgesia (20 patients), 5. ACL reconstruction using a cadaver graft, without intra-operative analgesia (5 patients).

ACL reconstruction was carried out, in tourniquet-induced ischemia, by one of the standard techniques mentioned above. An analgesic mixture of adrenaline (1 ml/1 mg), morphine (1 ml/10 mg) and Marcaine (0.5 %/20 ml) was administered into the joint under arthroscopic control before the procedure was terminated. In all cases, the drain was released at 30 min. after the end of surgery. The limb was immobilized in a brace and the joint was cooled with ice. When requested, intramuscular analgesics (Dolmina and Dipidolor) were given.VAS pain scores were recorded at 30 min, 1, 2, 4, 8, 12 and 24 h after surgery. The range was from 0 (no pain) to 10 (maximum pain) scores. In addition, the amount of intramuscular analgesics and the time of their administration after surgery were noted.

VAS pain scores were lowest in the patients with ACL reconstruction by cadaver BTB grafting, the highest scores were reported by the patients with autologous BTB graft reconstruction. Women perceived the operation as more painful than men. When the intra-operative analgesic mixture was used, the amount of post-operative opiate analgesics was reduced by 29 % and 46 % in group 3 and group 4 patients, respectively, and in group 3 its administration was postponed (first administration after an interval 1.7-times longer than in group 4). The number of patients not requiring any opiate drugs increased markedly in both these groups. Intra-operative analgesia resulted in only a slight decrease in VAS pain scores, more in group 3 than group 4.

Several analgesics are used for intra-articular administration in order to alleviate post-operative pain. The most frequently used drugs include bupivacaine, morphine or epinephrine, but their mixtures are more effective than any of the drug administered alone. The most apparent evidence of the effect was the reduced amount of opiate drugs required after surgery, which was significant in all patients treated with intra-articular analgesia (groups 3 and 4) and particularly in men. However, VAS pain scores in the two groups decreased only slightly. Since maximum pain is experienced at the graft donor site, the effect of the evaluated mixture is regarded as complementary and multi-modal analgesic therapy is recommended.

The use of intra-articular analgesia has a significant effect on the reduction of opiate amounts administered to patients during the 24-hour post-operative period after ACL reconstruction, regardless of the surgical technique used. These patients also reported slightly lower perception of pain, as assessed by the VAS pain score. The effect was higher in men than in women.