Table 5: Drainage versus no drainage: study details and qualitative outcomes
Study | n treatment/ control | Comparison | Supplemental analgesic | VAS scores and type of pain, where specified | Time to first analgesic request | Use of supplemental analgesic | Other important outcomes |
(LoE 1) | 39/39 | Closed-suction drain for 48 h (Drain) vs. no drain (Cont) | Postop: analgesia used, but no details given | NS at day 3, 1 week, 1 month or 4 months | __ | Number of requests for analgesia: NS on days 1–3 | Functional outcomes Knee flexion: NS; mean change in circumference of thigh, knee and calf: NS, except for knee on day 3, when Drain>Cont (p<0.0096) Hospital stay Length of hospital stay: NS Complications Overall incidence of skin edge necrosis, superficial wound infection, wound ooze, ecchymosis, or erythema: NS (p=0.058) |
50/50 | Single deep, closed-suction drain for 48 h (Drain) vs. no drain (Cont) | Not reported | NS on days 2, 6 or 10 (i.e. at all time points recorded) | __ | __ | Functional outcomes Mid-patellar circumference: NS; time to regain active straight-leg raising: Cont superior (p=0.02); active knee flexion: NS on days 3, 6 or 10 (i.e. at all time points recorded) Complications Volume of blood in dressings: Drain<Cont (p<0.01); number of patients requiring blood transfusion: NS | |
(LoE 1) | 30/30 | Peri-articular drainage for 48 h (Drain) vs. no drain (Cont) (both groups had a compressive dressing for 1 h postop) | Postop: oral/parenteral medications available, as required | NS on days 2, 7 or 14 (i.e. at all time points recorded) | __ | Not reported | Functional outcomes Knee flexion and circumference: NS on days 2, 7 or 14 (i.e. at all time points recorded) Hospital stay Length of hospital stay: NS Complications Blood loss: NS; incidence of blood transfusions: NS; transfused blood units: Cont superior (p=0.03) |