Description of studies

Description of studies

Literature search

• Systematic review of the literature from 1966–November 2005 using MEDLINE and EmBASE, following the protocol of the Cochrane Collaboration (Total Knee Arthroplasty November 2005 Search Terms)
• Inclusion of randomised studies in English, assessing analgesic interventions in total knee arthroplasty in adults, and reporting pain on a verbal or numerical rating scale or a linear analogue scale
  • Primary outcome measure: postoperative pain scores
  • Secondary outcome measures: supplemental analgesic requirements, other recovery outcomes (adverse effects, functional recovery)
• Identification of 247 studies of peri-operative interventions for postoperative pain following total knee arthroplasty
• 112 studies included (Total Knee Arthroplasty November 2005 Included References
• 135 studies excluded Total Knee Arthroplasty November 2005 Excluded References
• The most common reasons for exclusion were that the study combined data from knee and hip arthroplasty groups (51 studies) without an identifiable knee subgroup, or that pain scores were not reported (39 studies) (Table 1: Total Knee Arthroplasty November 2005 Reasons for Exclusion)

Study quality assessments, levels of evidence and grades of recommendation Recommendations are graded according to the overall level of evidence (LoE) on which the recommendations are based, which is determined by the quality and source of evidence: (Levels of evidence and grades of recommendation in PROSPECT reviews (from 2006)

• Click here for quality scores and levels of evidence for included procedure-specific studies: (Total Knee Arthroplasty November 2005 Quality Scoring + Levels of Evidence)

Quantitative analyses

Overall, few meta-analyses could be performed that used data from more than two studies. This is because there are a limited number of studies of homogeneous design that report similar outcome measures. Therefore, the majority of the procedure-specific evidence was assessed only qualitatively.

Transferable evidence

Transferable evidence of analgesic efficacy from comparable procedures or evidence of other outcomes, such as adverse effects, has been included to support the procedure-specific evidence where this is insufficient to formulate the recommendations.

Many studies that were identified in the literature search included patients undergoing total knee or hip replacement and reported data pooled from all these patients. Such studies are excluded from the procedure-specific systematic review but have been used as additional transferable evidence where required. Data from other types of orthopaedic surgery (e.g. ACL reconstruction, spinal surgery, hip surgery) were not used for transferable evidence of analgesic efficacy in most instances because it was considered that the pain profile of these procedures was too different from that of TKA. However, data from studies in a variety of procedures have been used for evidence of adverse-effects, which can occur regardless of the procedure.