Persistent post-surgical pain and neuropathic pain after total knee replacement

Table 2 Total knee replacement and neuropathic pain

Ref.	Design	No. of patients	Aim of the study	Scores-scales	Follow-up	Pain	Factors
Harden et al[28]	Prospective	77	Preoperative emotional distress and pain intensity and would predict the occurrence of signs and symptoms of CRPS following TKR	CRPS: IASP criteria (signs/symptoms) Beck Depression Inventory State Trait Anxiety Inventory McGill Pain Questionnaire-Short Form	Pre-op. Post-op.: (1) 1 mo; (2) 3 mo; and (3) 6 mo	1 mo: 21.0% 3 mo: 13.0% 6 mo: 12.7%	CRPS-like phenomena: (1) In a significant number of patients after TKR; and (2) No association with significantly greater complaints of postoperative pain Prediction by preoperative distress and pain: Modest utility
Buvanendran et al[30]	Prospective	Control: 120 Pregabalin: 120	To examine if perioperative treatment with pregabalin, would reduce the incidence of postsurgical NP	11-point NRS LANS scale Osteoarthritis Outcome Score–Physical function Short-form (KOOS-PS)	Pre-op. Post-op.: (1) 3 mo; and (2) 6 mo	Study group: 0% Placebo group: (1) 3 mo: 8.7%; (2) 6 mo: 5.2%	Perioperative pregabalin administration reduces the incidence of chronic NP after TKR In the doses tested, it is associated with a higher risk of early postoperative sedation and confusion
Wylde et al[9]	Retrospective	632	To assess: (1) prevalence; (2) severity; (3) sensory qualities; and (4) postoperative determinants of persistent pain after primary THR and TKR	WOMAC Pain Scale SF-MPQ PainDETECT Questionnaire Two-item PHQ-2	Median: 41 mo Range: 34-49 mo	Persistent postsurgical pain (PPSP): 44% Severe-extreme PPSP: 15% Constant PPSP: 5% Likely NP: 6%	Significant and independent postoperative determinants of number of PPSP: (1) No. of pain problems elsewhere; and (2) The presence of major depression
Phillips et al[29]	Prospective	94	To record the prevalence of pain and NP To establish predictive factors that could be used to identify patients who were likely to have high levels of pain or NP	VAS HADS score pD-Q score OKS	Pre-op. Post-op.: (1) 3-5 d; (2) 6 wk; (3) 3 mo; (4) 6 mo; (5) 9 mo; (6) 1 yr; and (7) 46 mo	VAS (value) Pre-op.: 5.8 Post-op.: (1) 3-5 d: 4.5; (2) 6 wk: 3.2; (3) 3 mo: 2.4; (4) 6 mo: 2.0; (5) 9 mo: 1.7; (6) 1 yr: 1.5; and (7) 46 mo: 2.0 Frequency (%) VAS moderate-severe/ painDETECT possible -likely Pre-op.: 41-50/5-1 Post-op.: (1) 3-5 d: 47-19/5-3; (2) 6 wk: 39-9/27-8; (3) 3 mo: 21-10/19-4; (4) 6 mo: 16-6/17-3; (5) 9 mo: 16-4/13-6; (6) 1 yr: 14-3/9-2; and (7) 46 mo: 15-7/7-6	High correlation between the mean VAS scores for pain and the mean painDETECT scores at 3 mo, 1 yr and 3 yr post-operatively No correlation between the pre-operative scores and any post-operative scores at any time point NP is an underestimated problem in patients after TKR

CRPS: Complex regional pain syndrome; NP: Neuropathic pain; Pre-op: Preoperatively; Post-op: Postoperatively; LANS: Leeds Assessment of Neuropathic Symptoms and Signs; NRS: Numerical Rating Scale; WOMAC: Western Ontario and McMaster Universities Index of Osteoarthritis; SF-MPQ: Short-Form McGill Pain Questionnaire; PHQ-2: Patient Health Questionnaire; VAS: Visual Analogue Score; HADS: Hospital Anxiety and Depression; pD-Q: PainDETECT; OKS: Oxford Knee score.