Chronic low back pain in traumatic lower limb amputees.

OBJECTIVE

To ascertain the prevalence of back pain amongst traumatic lower limb amputees attending a regional rehabilitation centre and to determine the possible causes of back pain.

DESIGN

All traumatic lower limb amputees given a semi-structured questionnaire to complete and a comparative subgroup of amputees with back pain and without back pain underwent physical examination, gait analysis, magnetic resonance scanning (MRI) and gait/standing stability analysis.

SETTING

A subregional amputee rehabilitation centre.

RESULTS

Transfemoral amputees were more likely to suffer from back pain (81 %) than transtibial amputees (62%) (p<0.05) and of those suffering from severe back pain, 89% and 81% also suffered from severe pain in the phantom limb and severe stump pain respectively. In two comparative subgroups of amputees there was no significant difference between back pain and pain-free groups except those with pain were more likely to have a body mass index (BMI) ratio above 50% of the recommended ratio. No difference in degeneration or disc disease between the groups on MR scans was found. Impact ground reaction forces during walking, irrespective of limb, were significantly greater (p < 0.05) in the pain-free group than in the pain group, as was walking speed. Gait asymmetry measures were similar in both groups. Centre of pressure displacement measures during standing were greater in the pain group than in the pain-free group.

CONCLUSIONS

Low back pain in amputees is a significant problem equal to that of pain in the phantom limb and a biomechanical (myofascial) rather than a degenerative aetiology is suggested.