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VOL. 81-B, NO. 4, JULY 1999

567F. Postacchini, MD, Professor of Orthopaedic SurgeryClinica Ortopedica University of Rome ‘La Sapienza’, Piazzale AldoMoro 5, 00185 Rome, Italy.©1999 British Editorial Society of Bone and Joint Surgery0301-620X/99/410213 $2.00J Bone Joint Surg [Br] 1999;81-B:567-76.Review articleMANAGEMENT OF HERNIATION OF THE LUMBAR DISCF. PostacchiniThe natural history of lumbar disc herniationClinical evolution.It is extremely difficult to study clinicallythe natural history of a condition causing pain, since patientsalmost inevitably undergo some form of treatment. This mayexplain the paucity of information on the natural evolution ofthe clinical symptoms and signs of disc herniation.In a multicentre prospective study, Weber, Holme andAmlie1analysed 208 patients who presented with the clin-ical features of lumbar radiculopathy probably due to discherniation. In no case was herniation diagnosed by imagingstudies. All the patients were examined between two andfour weeks after the onset of symptoms and a questionnairewas used to evaluate their clinical status at three and 12months. All were instructed to observe complete bed restfor one week. Some were treated with piroxicam, whereasthe others were given a placebo. No significant differencein the evolution of signs and symptoms was observedbetween the two groups. During the first four weeks afterthe onset of the symptoms, 70% of patients had a consider-able decrease in pain and almost 60% had resumed work.By one year, some 30% complained of back pain,decreased working ability and limitation in recreationalactivities; 19.5% had not resumed work. Four patients hadbeen treated by operation.In a prospective, randomised double-blind study by Fras-er,230 patients had chymopapain chemonucleolysis and 30were injected with saline. Disc herniation was diagnosed bymyelography in all patients. At six weeks, only 37% ofpatients in the placebo group had a satisfactory clinicalresult. This increased to 57% at six months but haddecreased to 47% by two years.3Operation had beenundertaken in 40% of patients. The results of this study arenot consistent with those reported by Weber et al,1but, inthe latter trial, the diagnosis of disc herniation had beenmade solely on clinical grounds by non-specialists. Fras-er’s2patients had been referred to a specialist centre,probably after failure of conservative management, and theclinical diagnosis of disc herniation had been confirmed bymyelography.Pathomorphological evolution.In recent years, numerousstudies4-7have shown that a disc herniation may decreasein size or disappear in the course of a few months, nomatter whether it is contained, extruded or migrated, or ofa small or large size (Fig. 1). In a prospective study,4111patients with disc herniation or annular bulging diagnosedby CT, had a second CT one year later after one or moreepidural injections of steroids. Of the patients with discherniation, 76% showed a decrease in size, with one-fifth ofthose demonstrating disappearance of the protrusion, oncontrol CT scans. Only 29% of patients with a bulgingannulus fibrosus showed such shrinkage. Deterioration wasobserved on CT scans in only four patients (5%). Similarfindings were observed by Maigne et al6; of 48 patientswho had a further CT scan one to 48 months after the initialexamination, 64% showed a decrease of over 75% in thesize of the herniation with shrinkage of between 50% and75% in 17% of the cases.Large herniations tend to decrease in size to a greaterextent,5-7but extruded protrusions of small size show lesstendency to spontaneous resolution. A decrease in size mayoccur in the course of a few weeks before complete resolu-tion of the symptoms. A retrospective study8has shownthat after a mean period of 262 days, most extruded hernia-tions had become smaller or had disappeared after con-servative management, but few of the contained protrusionsshowed any significant change.Little is known about the mechanisms leading to thesechanges. In contained protrusions, the main mechanism islikely to be dehydration of the herniated nucleus pulposus.This may account for the higher frequency with whichyoung subjects present a decrease in size of their hernia-tion.4In extruded or migrated discs, phagocytosis of her-niated tissue by macrophages probably plays the primaryrole.Results of conservative treatmentIn a large proportion of patients conservative treatmentrelieves pain in a few days to several months. Resolution ofsymptoms may occur in the presence of herniations of anytype or size.

In a retrospective study,958 patients with disc herniationtreated conservatively by analgesics, anti-inflammatorymedication (NSAIDs), epidural injection of steroids, at alow back school or by exercises, were followed for a meanperiod of 31 months. Surgery was necessary in 10%because of inadequate resolution of the symptoms. Of theremaining 52, 50 had an excellent or good clinical resultand 48 resumed work after a mean period of 3.8 months. Ofthe patients with extruded herniation (26%), 87% obtainedsatisfactory results and all returned to work irrespective ofthe presence of a neurological deficit. In another series of114 cases,414% of patients required surgery because offailure of conservative treatment; in the remainder, non-surgical treatment, such as epidural or paraforaminal injec-tions of anaesthetics and steroids, led to satisfactory results.Similar outcomes with 90% of satisfactory results havebeen reported by Maigne et al6using a combination ofseveral treatments such as bed rest, NSAIDs, epiduralinjections of steroids or corsets.Conservative versussurgical management.Hakelius10analysed retrospectively 417 patients treated conservativelyby bed rest, a corset and physiotherapy and 166 who hadsurgery. The patients were assessed monthly for the first sixmonths after the beginning of treatment or operation andmost were followed for a mean of 7.4 years. In the firstmonth, 76% of patients managed conservatively had “bene-fited” from treatment, compared with 97% of the operatedpatients, but at six months the percentages were similar(93% and 99%, respectively). The mean time away fromwork was only slightly longer in patients treated con-servatively. At six months, the percentage of patients stillaway from work was 37% in the group with disc herniationdemonstrated by myelography and treated conservativelyand 7% in the surgical group. In the long term the resultswere only slightly better in the patients treated surgically.The incidence of recurrences of radicular pain in the yearsafter conservative treatment was 20% compared with 10%in patients undergoing operation. The limitation of thisstudy is that the choice of treatment was not randomisedand thus the two groups of patients are not comparable.In a prospective study by Weber,11280 patients with discherniation demonstrated by myelography were assigned tothree groups. Group I included 87 with mild symptoms whowere treated conservatively. The 67 patients in group II inwhom there were absolute indications for surgery, had anoperation. The 126 patients in group III in whom the needfor operation was not so obvious were randomly assignedto conservative (81 cases) or surgical (73 cases) manage-ment. All patients in group III were followed up for one,four and ten years after treatment. At one year the per-centage of satisfactory results was significantly lower in theconservative (61%) than in the surgical (80%) group. Afterfour years it was still lower in the conservative group, butthe difference was no longer statistically significant. Com-parable results were observed at ten years. Of the 66patients in the conservative group, 25% had had surgeryduring the first year because of the persistence or worsen-ing of symptoms. Neurological deficits improved or dis-appeared in comparable proportions in the two treatmentgroups. The main defect of this study is that only thepatients with uncertain indications for surgery wererandomised for treatment.A recent investigation12evaluated retrospectively 55truck drivers, 30 of whom had had prolonged conservativemanagement and 25 an operation. The results of treatmentwere analysed, as was the cost of health care in the fiveyears after initial presentation. In both groups, 80% ofpatients had a satisfactory outcome. There were no sig-568F. POSTACCHINI