Abstract
Massive disc herniations after surgical decompression develop secondary back pain due to important loss of nucleus material with instability. No earlier proposed method to restore disc function was biological.
Chondrocyte culturing allows living repair of lost disc tissue. The contained disc space appears particularly suitable for receiving those tissue cultures. Surprisingly disc replantations had not been attempted before.
In 1996 two women and one man (aged 38-55) underwent open resection of a massive disc herniation by hemi-laminotomy, twice at L5-S1, once at L4/5.
All the excised disc tissue was given to tissue culture in an identical protocol as in autologous chondrocyte transplantation (ACT) for articular cartilage repair. After sufficient cell multiplication (11.5-23 millions living cells in 750 μl) four weeks later the engineered autolo-gous disc tissue was injected in suspension through a contra-lateral puncture under local anaesthesia.
In prospective follow up a simplified Oswestry Disability Index was recorded and functional radiographs and NMR were taken after one, three, six and nine years.
All three patients remained freed from radicular pain and vertebral symptoms over the whole follow up period. Two patients never had functional restrictions nor loss of working capacity (Oswestry 1 and 6), one after retirement at 5 years developed rheumatoid disease but is still unchanged at the lumbar spine. The third patient partially recovered from preoperative radiculop-athy (slight loss of strength and sensitivity S1) but still works, with minor adaptations to his original professional activity (Oswestry 18).
Functional radiographs up to the last follow up didn’t show vertebral instability. In all cases the replanted intervertebral disc space remained unchanged with minimal widening in one case.
In NMR all three discs had partial signal recovery. Twice during the first year a new outgrowth of disc tissue was observed at the site of the primary disc herniation opposite to the replanting injection, without any clinical correlation.
Three cases with massive lumbar disc herniations showed good clinical and large anatomical recovery persisting nine years after reimplantation of engineered autologous disc tissue. The encouraging results of this small pilot study led to further closely monitored clinical applications before wider propagation of biological disc repair surgery.
Correspondence should be addressed to Mr Carlos Wigderowitz, Senior Lecturer, University Department of Orthopaedic and Trauma Surgery, Ninewells Hospital and Medical School, Dundee DD1 9SY.
