[Postoperative Dissociation after Knee Replacement and its Influence on the Course of Pain]. / Postoperative Dissoziation nach Totalem Kniegelenkersatz und ihr Einfluss auf den Schmerzverlauf.

OBJECTIVE: Even after successful knee replacement, one in 5 patients complains of chronic pain. Previous studies suggest that surgical interventions trigger postoperative traumatic stress in some patients. The aim of this explorative study is to investigate whether postoperative dissociation occurs as a manifestation of postoperative traumatic stress after total knee replacement. In addition, it should be investigated whether these patients have more chronic postoperative pain 1 year postoperatively and to what extent the course of pain differs from the other patients. METHODS: 201 Patients who underwent primary knee TEP were studied. They answered questionnaires on knee pain (WOMAC) and dissociation (FDS-20) at 3 measurement points: 1 day preoperatively (T1), 10 weeks postoperatively (T2) and 1 year postoperatively (T3). RESULTS: Data from 145 patients could be analyzed. The incidence for postoperative dissociation is 8.3%. Not only do patients with postoperative dissociation report more chronic postoperative pain after 1 year (p=0,016), but also their postoperative pain levels decreases less than in the patients without postoperative dissociation (p=0,025). DISCUSSION: The findings provide evidence that postoperative dissociation occurs as a manifestation of postoperative traumatic stress after total knee replacement. Even if dissociation seems to be a defense mechanism for the regulation of overstraining affects in the short term, it is associated with more chronic postoperative pain in the long term. Furthermore, the patients with postoperative dissociation benefit less in a 1-year follow-up from total knee replacement in terms of pain reduction. CONCLUSION: Strategies to reduce dissociation could lead to better results after knee TEP implementation and should be investigated in future intervention studies.

The Pain Paradox of Borderline Personality and Total Knee Arthroplasty (TKA): Recruiting Borderline Personality Organization to Predict the One-Year Postoperative Outcome.

BACKGROUND: TKA is a common treatment for arthropathies of the knee; however, its results are compromised by psychosocial equivalents of pain: prior research suggests persistent pain and dysfunction after TKA not only to be linked to psychological symptoms such as depression or anxiety but also to psychodynamic determinants of borderline personality, namely borderline personality organization. Osteoarthritis (OA) and Rheumatoid arthritis (RA), the main indications for TKA, are themselves linked to personality factors and disorders, e.g. borderline. The present study investigates the influence of borderline personality organization (BPO) on the outcomes of TKA one year postoperatively. METHODS: We studied 144 patients scheduled for primary TKA before and after the operation using the IPO-16 and the WOMAC for the assessment of knee pain and function. RESULTS: Non-parametric correlations were found between primitive defenses and knee-pain, not function. Linear regression showed prediction of knee pain and knee function by the preoperative WOMAC scores (p<0.01), whereas there was additional prediction of knee-pain by gender (p=0.03) and primitive defenses (p=0.04). DISCUSSION: The results suggest a psychodynamic mechanism of maladaptation after TKA apparently representing the bodily manifestations of fundamental psychic defenses.

Dissociation and Pain-Catastrophizing: Absorptive Detachment as a Higher-Order Factor in Control of Pain-Related Fearful Anticipations Prior to Total Knee Arthroplasty (TKA).

Total Knee Arthroplasty (TKA) is the ultima-ratio therapy for knee-osteoarthritis (OA), which is a paradigmatic condition of chronic pain. A hierarchical organization may explain the reported covariation of pain-catastrophizing (PC) and dissociation, which is a trauma-related psychopathology. This study tests the hypotheses of an overlap and hierarchical organization of the two constructs, PC and dissociation, respectively, using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the Childhood Trauma Screener (CTS), a shortened version of the Dissociative Experiences Scale (FDS-20), the Brief Symptom Inventory (BSI-18), the Pain-Catastrophizing Scale (PCS), and the Tampa Scale of Kinesiophobia (TSK) in 93 participants with knee-OA and TKA. Non-parametric correlation, linear regression, and an exploratory factor analysis comprising the PCS and the FDS-20 in aggregate were run. The three factors: 1) PC factor, 2) absorptive detachment, and 3) conversion altogether explained 60% of the variance of the two scales. Dissociative factors were related to childhood trauma, and the PC-factor to knee-pain. The latter was predicted by absorptive detachment, i.e., disrupted perception interfering with the integration of trauma-related experiences possibly including invasive surgery. Absorptive detachment represents negative affectivity and is in control of pain-related anxieties (including PC). The clinical associations of trauma, psychopathology, and maladaptation after TKA may be reflections of this latent hierarchical organization of trauma-related dissociation and PC.