Patellar and Achilles tendinopathies are predominantly peripheral pain states: a blinded case control study of somatosensory and psychological profiles.

STUDY DESIGN: Case-control design. BACKGROUND: Tendinopathy is characterised by pain on tendon loading. In persistent cases of upper limb tendinopathy, it is frequently associated with central nervous system sensitisation, whereas less commonly linked in the case of persistent lower limb tendinopathies. OBJECTIVES: Compare somatosensory and psychological profiles of participants with persistent patellar (PT) and Achilles tendinopathies (AT) with pain-free controls. METHODS: A comprehensive battery of Quantitative Sensory Testing (QST) was assessed at standardised sites of the affected tendon and remotely (lateral elbow) by a blinded assessor. Participants completed the Victorian Institute of Sports Assessment, a health-related quality of life questionnaire, the Hospital Anxiety and Depression Scale and the Active Australia Questionnaire. Independent t-test and analysis of covariance (sex-adjusted and age-adjusted) were performed to compare groups. RESULTS: Participants with PT and AT did not exhibit differences from controls for the QST at the remote site, but there were differences at the affected tendon site. Compared with controls, participants with PT displayed significantly lower pressure pain threshold locally at the tendon (p=0.012) and fewer single limb decline squats before pain onset, whereas participants with AT only displayed fewer single heel raises before pain onset, but this pain was of a higher intensity. CONCLUSION: PT and AT appear to be predominantly local not widespread pain states related to loading of tendons without significant features of central sensitisation. LEVEL OF EVIDENCE: Level 4.

Psychological Distress and Widespread Pain Contribute to the Variance of the Central Sensitization Inventory: A Cross-Sectional Study in Patients with Chronic Pain.

OBJECTIVES: Central sensitization (CS) implies increased sensitivity of the nervous system, resulting in increased pain sensitivity as well as widespread pain. Recently, the Central Sensitization Inventory (CSI) was developed to assess symptoms of CS and central sensitivity syndromes. The aim of this study was to examine the convergent validity of the CSI by comparing the outcome to psychosocial factors and clinical features of CS. METHODS: In a cross-sectional explorative study, patients with chronic pain completed multiple questionnaires, including the CSI, Pain Catastrophizing Scale, and Symptom Checklist 90, for psychological distress, duration of pain, intensity of pain, widespread pain, and lateralization of pain. Based on bivariate correlations, relevant predictors of CS were selected and used to fit an exploratory structural equation model (SEM) of CS. RESULTS: In total, 114 patients with chronic pain were included, 56.1% being women. The average pain duration was 88 months. The mean total score on the CSI was 36.09 (15.26). The CSI was strongly related to known contributing and related factors of CS. SEM analysis showed that both psychological distress and widespread pain contributed significantly to the variance in symptoms of CS in patients with chronic pain. CONCLUSION: In this study, the convergent validity of the CSI was measured with demonstration of a strong relationship between contributing factors and clinical features of CS. These findings of convergent validity, considering former studies of the CSI, underline the use of the questionnaire in the clinical practice.

Neuropathic pain mechanisms in patients with chronic sports injuries: a diagnostic model useful in sports medicine?

OBJECTIVE: The pathophysiology of chronic sports injuries such as overuse or tendinopathy remains largely unknown. With this exploratory study, we aim to detect signs of sensitization of the nervous system. Sensitization is an indication of the involvement of neuropathic mechanisms in patients with chronic sports injuries. DESIGN: Sensory descriptors were assessed by means of a neuropathic pain questionnaire (DN4-interview) and by three methods of sensory testing. The test results were integrated in a scoring system. SETTING: Patients were recruited from an outpatient clinic of a University Medical Centre and at primary care physical therapy practices. PATIENTS: Fifteen athletes with a unilateral chronic sports injury were included. OUTCOME MEASURES: All subjects filled out the seven-items of the DN4-interview to assess sensory descriptors. Next, the presence of brush-evoked allodynia was assessed and pain thresholds with Von Frey monofilaments and a pressure algometer were measured in all patients to determine signs of sensitization. RESULTS: Based on the scoring system, in 4 out of 15 patients (27%) the presence of sensitization could be detected. In two other patients, signs of hypoalgesia were observed. CONCLUSIONS: The involvement of sensitization as an explanation for the pain in chronic sports injuries is credible in a considerable proportion of patients. With respect to treatment, the establishment of such neuropathic pain mechanisms is of clinical significance.

Impact of shoulder complaints after neck dissection on shoulder disability and quality of life.

OBJECTIVE: To explore relationships between shoulder complaints after neck dissection, shoulder disability, and quality of life. To find clinical predictors for mid- to long-term shoulder disability. STUDY DESIGN: Prospective. PATIENTS AND METHODS: Shoulder pain, shoulder mobility, and shoulder droop, as well as scores on shoulder disability questionnaire and RAND-36 (quality of life), were measured at baseline, discharge (T1), and 4 months postoperatively (T2) on 139 patients admitted for neck dissection to major head and neck centers in the Netherlands. RESULTS: Shoulder mobility was significantly decreased at T1 and did not improve. Significant relationships between shoulder function, shoulder disability score, and RAND-36 domains were found. Two clusters of clinical symptoms could be identified as independent predictors for shoulder disability. CONCLUSIONS: Objective deterioration in shoulder function after neck dissection is associated with perceived shoulder disability and related to physical functioning and bodily pain. Predictors for shoulder disability can be found.