People with severe degenerative conditions, such as osteoarthritis (OA), have been shown to have altered movement patterns during sit-to-stand. However it remains unclear whether such alterations exist in people with early OA, in the absence of pain. This study aimed to determine if a novel seat could be used to discriminate people with early OA compared with controls. The sit-to-stand task was performed by 20 people with early medial knee OA and 20 age and gender-matched control subjects, using an instrumented seat. OA subjects showed altered weight distribution in the transition phase from sit to stand, in that they placed more load through their unaffected side. Task duration was also significantly longer for OA subjects. This study has demonstrated that a novel instrumented seat can be used to discriminate people with early medial knee OA during the sit-to-stand activity. These results may be relevant for early interventions to delay or prevent changes in muscle function of the affected limb as well as contralateral knee or hip osteoarthritis in these patients.

Introduction: Changes in the central nervous system (CNS) pathways controlling trunk and leg muscles in patients with low back pain and sciatica have been demonstrated. The aim of this study is to investigate whether these changes are altered by surgery.

Methods: Corticospinal excitability was examined on 2 occasions in 15 patients prior to and 6 weeks following lumbar decompression surgery and 7 control subjects – at the same time intervals. This was achieved by recording electromyographic (EMG) activity from tibialis anterior (TA), soleus (SOL), rectus abdominis (RA), external oblique (EO) and erector spinae (ES) muscles at the T12 & L4 levels in response to transcranial magnetic stimulation (TMS) of the motor cortex.

Results: A significant asymmetry in the cortical silent period (cSP) between the side ipsilateral to the pain and the contralateral side was found pre- but not post surgery in ES at L4 (P=0.012) and SOL (P=0.039). An asymmetry in the size of motor evoked potentials (MEPs) was also found in TA (P=0.009) which was no longer significant post surgery. Abdominal responses could be recorded in 10 subjects, where significant decreases in contralateral cSP in EO (P=0.021) and RA (P=0.033) were found. In controls no significant differences or changes were found.

Discussion: These results show significant asymmetries in the CNS control of trunk and leg muscles in patients prior to surgery to relieve pain which are resolved by the surgery. The degree of change in asymmetry may reflect the variability in surgical outcome. This work is currently ongoing.

Conflicts of Interest: None

Funded by: the DISCS foundation

The majority of studies investigating the outcome of lumbar decompression surgery have been retrospective in nature and have not used validated measures of outcome. They have rarely gathered any information regarding patient rated expectations of surgery and measures of satisfaction with surgery. The aim of this study was to prospectively investigate the short and long term outcome of lumbar decompression surgery in terms of function, disability, general health and psychological well being and to examine patient expectations of surgery and short and long term satisfaction with the outcome of decompressive surgery.

Eighty-four patients undergoing lumbar spinal stenosis surgery were recruited into this study. Patients were assessed using validated measures of outcome pre-operatively, and at six weeks, six months and one year postoperatively. On recruitment into the study patients were also asked to rate their expectations of improvement in pain, general health, function etc. In addition at each review stage patients were asked to rate their satisfaction in improvement of these key outcome measures.

A significant reduction in pain (p< 0.001) was observed at the six week post-operative stage, this did not change at the subsequent assessment stages. Only some of the SF~36 categories were sensitive to change. The sub-categories that were sensitive to change were; physical function (p< 0.05); bodily pain (p< 0.001); and social function (p< 0.05). Improvements were observed in these categories at the six week and six month reviews. A gradual reduction in the Oswestry Disability Index (ODI) was observed with time, with changes principally being observed between the six week and six month review, and six week and one year review stages (p< 0.05). Minimal changes were observed in the psychological assessments with time. The outcome of surgery could not be predicted reliably from psychological, functional or pain measures.

The results also demonstrated that patients had very high expectations of recovery particularly in terms of pain and function and that patients were confident of achieving this recovery (76.8%) confident of a good result. Levels of satisfaction however, varied considerably. 41% of subjects were 50% satisfied with the outcome, whilst 30% were dissatisfied. Most patients felt that they had made the right decision to have surgery although the surgery had only achieved 43.4% ± 37.8 of the outcome they had expected.

In conclusion, lumbar decompression surgery leads to a reduction in pain and some improvements in function. Examination of patient’s expectations of and satisfaction with surgery revealed that frequently patients had unrealistic expectations of their surgery and as a consequence tended to have lower levels of satisfaction.