The Short-term And Long-term Clinical Effect Of Intra-articular Cocktail Analgesic Mixture Injection After Total Knee Arthroplasty

Purpose: To evaluate the short-term and long-term clinical effect of intra-articular cocktail analgesic mixture injection after total knee arthroplasty.Methods: Forty patients with osteoarthritis undergoing unilateral TKA by the same surgeon team were randomly divided into two groups(A and B), Each group had 20 patients, and the numbers of male and female in Group A were 3 and 17,age ranked from 54 to 76,the mean age was(62.75±5.80)years; the numbers of male and female in Group B were 2 and 18,age ranked from 51 to 67,the mean age was(59.95±1.04)years. Group A was given a protocol of intra-articular multimodal drug injection, namely, “cocktail injection”,which was consisted of 150 mg ropivacaine and 10 ug sufentanil,then joined saline to 100 ml and injected into surrounding tissue of knee(articular capsule, ligament, subcutaneous tissue contained). The injection was made in three stages. The first injection was done after the bone cuts had been made and before insertion of the prosthesis. About 40 ml was injected into the tissues around the posterior joint capsule, gently withdrawing the plunger of the syringe before injection in preventing multimodal drugs from being injected into blood vessels of popliteal fossa. The second injection was done after the components had been inserted, but before bone cement was solidified. About 30 ml was injected into the medial and lateral collateral ligaments, the anterior joint capsule, the periosteum, the quadriceps tendon, the capsule incision and the infrapatellar ligament. The third injection of 30 m L of the same mixture was made into the subcutaneous tissue before skin closure and tourniquet release. Group B was given all the operation above, apart from injecting 100 ml saline without ropivacaine and sufentanil. After the operation, if the patients felt pain hard to bear, they were delivered 100 mg tramadol hydrochloride by intramuscular injection. The postoperative frequency of adding painkilling 5 drugs, general condition and incidence of postoperative adverse reaction within 48 h, the postoperative visual analog scores(VAS) for pain within 48 h and at 1 year, were examined and compared between two group. Visual analogue scale was measured with a 10 cm long ruler, which had 10 scale on one side. Both ends represented 0 and 10 score respectively, and 0 score showed painless, then 10 score showed excruciating pain. When the patients were inquired, they faced one side without scale, then they were asked to point out the location where represented their pain. The operator faced one side with scale, then got the corresponding points according to the location where the patients marked. At 1 year follow-up, the motion VAS was examined by using a dynamic test(stair-climbing test),namely, the patients followed-up were required to walk up and down 10 stairs of 15 cm height. Chronic pain was defined as a visual analogue scale≥4 during a stair-climbing test by evaluating patients at 1 year.Results:1 There was no significant difference of age, sex ratio, weight, operation time between both groups(P>0.05).2 VAS score within 48 hoursAt 4,8,16,24,48 hours after the TKA, the rest VAS in Group A were 3.27±0.39,3.46±0.41,4.08±0.31,3.47±0.42,3.33±0.36 respectively, and the motion VAS were 4.14±0.46,4.80±0.44,5.17±0.44, 4.62±0.36,4.32±0.30 respectively; the rest VAS in Group B were 3.27±0.39,3.46±0.41,4.08±0.31,3.47±0.42,3.33±0.36 respectively, and the motion VAS were 3.38 ± 0.40,4.05 ± 0.29,4.65 ± 0.40,4.48 ± 0.32,3.29 ± 0.37 respectively.At 4,8,16,24 hours after the TKA, the motion VAS in Group A was lower than that in Group B(P<0.05), there was no significant difference between both groups at 48 hours after the operation(P>0.05). At 8,16,24 hours after the TKA, the rest VAS in Group A was lower than that in Group B(P<0.05), there was no significant difference between both groups within 4 hours and after 48 hours after the operation(P>0.05).3 Postoperative frequency of adding painkilling drugsThere was no significant difference of postoperative frequency of adding tramadol hydrochloride tramadol hydrochloride between both groups.(P>0.05)4 Postoperative general conditionsThere was no significant difference of heart rate, oxygen saturation, mean arterial pressure between both groups.(P>0.05)5 Incidence of postoperative adverse reactionThere was no significant difference of nausea, vomiting, skin itch and respiratory depression between both groups(P>0.05).6 Postoperative follow-up status at 1 yearAt 1 year follow-up, the rest VAS in both groups were 0.89±0.25 and 1.06±0.34 respectively,there was no significant difference(P>0.05); the motion VAS in both groups were 2.81±0.47 and 3.22±0.68, which in Group A was lower than that in Group B(P<0.05).The incidence of postoperative chronic pain in Group A was 5.0 %(1/20),30.0 %(6/20)in Group B, a statistically significant difference(P<0.05). The incidence of postoperative chronic pain in Group B was thought 6.0 times(P<0.05) up on that in Group A.Conclusion: Intra-articular cocktail analgesic mixture injection can relieve acute pain effectively and offer earlier rehabilitation; in addition, it may play an important role in the protection of chronic pain, which make it a good option for postoperative analgesia after TKA.