Sarcopenia and its effects on outcome of lumbar spine surgeries

Sarcopenia, defined as progressive impairment of muscle function secondary to loss of skeletal muscle mass, has prevalence of 24-56% in patients > 60 years. Forty-four per cent of elderly patients undergoing orthopaedic surgery are found to be sarcopenic. It is a known risk factor for fall, fractures, disability, increased post-operative morbidity and mortality. If diagnosed pre-operatively, it can help prepare the patient and surgical team to foresee complications and thereby reduce morbidity and mortality. In the present study, we evaluated and correlated sarcopenia with the surgical outcome of operated patients with lumbar spine pathology.

A prospective, observational study was conducted on 114 patients > 40 years undergoing lumbar spine surgeries, who were studied and followed up for 3 months. They were segregated into 5 groups based on age (40-50 year, 50-60 year, 60-70 year, 70-80 year, and  > 80 year) and were assessed separately. Data on demography, grip strength analysis, 30-s chair stand test, Psoas muscle index (calculated on pre-operative MRI), pre- and post-operative ODI (Oswestry Disability Index) scores at 2 weeks and 3 months, Dindo-Clavien Classification of peri-operative complications, 90-day readmission rates and mortality (if any) were included. Patients were segregated into sarcopenic and non-sarcopenic groups based on the definition and set parameters as per the European Working Group on Sarcopenia in Older People (EWGSOP). A comparative analysis between these groups was performed.

Of 114 patients, there were 18 patients in 40-49 years, 24 in 50-59 years, 33 in 60-69 years, 30 in 70-79 years and 9 in > 80 years age group. Statistically significant difference in peri-operative ODI scores was seen in sarcopenic vs non-sarcopenic patients in all age groups (p < 0.05) except 40-49 years. The results showed that sarcopenic group had higher rate of peri-operative complications, delayed mobilisation, longer stay and mortality compared to non-sarcopenic group.

We conclude that sarcopenic patients have poor outcome in lumbar spine surgery compared to those without. So, by diagnosing sarcopenia using tests routinely done as pre-operative requirement, one can reduce radiation exposure and cost of treatment. The management can be revolutionised by predicting those who are at high risk of developing post-operative complications and poor surgical outcomes by mere diagnosis of sarcopenia. This knowledge will benefit both the patients and the surgeons.