Back pain in primary care : aspects on treatment and the possible influence of oral contraceptives

Abstract

The general objectives of this thesis were to investigate back pain in a primary-care setting, and especially to study the effect of manual treatment on pelvic-joint dysfunction, the effect of sterile-water injections on chronic, myofascial pain and the possible influence of oral contraceptives (OC) on back pain in women in the fertile ages.

The effect of a single intervention with manipulation mobilisation was compared with that of massage on pelvic-joint dysfunction with regard to sick-leave, consumption of analgesic, pain and joint mobility. The patients (n=39) formed two groups for treatment and sham treatment, respectively. The outcome as regarded sick-leave and use of analgesics, was significantly lower for the treatment group, while mobility, as measured by Patrick's test and also pain assessments with VAS, did not differ significantly.

Sterile water injections sub- and intracutaneously were compared with saline injections given the same way in a randomised, controlled trial on 117 patients with chronic myofascial pain in six different medical centres. A single intervention session was used. Both interventions had a positive effect on pain and mobility, but sterile water was not found to be better than saline with regard to pain relief. In a population study, 1,006 women in the ages 14-44 years, of whom 503 were OC users according to a register of pharmaceuticals used and 503 had not been using OC for the last 5 years, the registers of primary health diagnoses were compared, and a difference in low-back- pain (LBP) diagnoses was found, in that the OC users had a higher prevalence of LBP as a cause of primary care contact than the non-users had. The difference was significant (p<0.05) for 2 of the recorded 5 years.

To investigate the possible causes of this association, serum relaxin was measured during the menstrual cycle in 12 healthy women and in 7 women with chronic, posterior,pelvic pain (PPP). Relaxin was also recorded during 1 month of OC use in the healthy women. Relaxin was detected during the menstrual cycle in both groups of women and also during OC use and tended to be higher during OC use. Collagen metabolism markers, the aminoterminal of procollagen type I (PINP), the carboxyterminal telopeptide of type I collagen (ICTP) and the aminoterminal of procollagen type III (PIIINP), were also measured in two groups of non- pregnant women, 20 healthy nulliparous, before and at 3months and 1 year of OC-use and 12 with PPI? complaints, during the normal menstrual cycle and also during one month of OC use. Collagen turnover was diminished during OC use and a shift was also recorded in the anabolic/catabolic hormone balance tending towards an increased catabolism, as estimated by the levels of sexual- hormone-binding globulin (SHBG), insulin growth factor I (IGF-I) and testosterone.

In conclusion, the outcome of the treatment trials points to a positive effect of manual treatment on pelvic-joint dysfunction of acute and sub-acute duration, while sterile-water injection treatment could not be recommended for chronic myofascial pain. LBP in women was found to be associated with OC use. Whether the association is causal or not cannot be concluded from this study. However, also serum-relaxin levels and collagen metabolism were influenced by the use of OC s.