Background: Over several decades, investigators have been trying to identify the painful degenerate disc. Their work included two main methods. The first was to set criteria on the radiological investigations, mainly the MRI scan, to describe the severity of the degenerative disc disease (DDD); and the second was to perform discographies. Neither of these two methods precluded the need for the other.

Purpose: Using Pfirrmann’s classification, we correlated static MRI images, for the severity of segmental disc degeneration, with dynamic lumbar discography, with the aim to improve the identification of painful ‘disco-genic’ intervertebral segments.

Study design: Prospective cohort study. Inclusion criteria included patients with mechanical low back pain who exhausted the conservative measures and required surgical treatment.

Patient Sample and Methods: We investigated 69 patients (45 females, 24 males). The average age was 38.9 years (range 20–56). All patients had degenerative disc disease (DDD) on lumbar MRI scans. Provocative discographies were performed in all cases as a routine investigation to identify painful levels prior to fusion or disc replacement surgery. The severity of DDD was graded using Pfirrmann’s classification. A total of 162 discographies were performed using the ‘miss the facet joint, double needle technique’.

Outcome measures: During discography typical or concordant pain only was regarded as positive. Among each of the five Pfirrmann grades, the percentage of positive discographies was calculated. Significance and correlation then were investigated using the Chi-squared and Spearman’s correlation tests.

Results: 24 discs were classified as Pfirrmann grade I, 33 grade II, 63 grade III, 27 grade IV and 15 grade V. The percentages of positive provocative discography for concordant pain among these groups were 0%, 9.1%, 71.4%, 100% and 100% respectively. Statistical analysis showed a high correlation between the severity of DDD on MRI scan and the result of the provocative discography (Chi2 = 32.96, P < 0.001 and correlation coefficient = 0.756).

Conclusion: The higher the grade of segmental DDD, the more likely it will be painful on discography. All discs showing Pfirmann grade IV and V disease were painful on discography. We strongly recommend the Pfirrmann classification for use in grading the severity of lumbar DDD especially when assessing for its association with discogenic pain as determined by provocative discography.

Introduction: The role of discography before lumbar fusion had been discussed in the literature. No study discussed its role before total lumbar disc replacement (TDR). Degenerate discs are not necessarily painful, even if they show Modic changes or HIZ. Moreover, discogenic pain might not be the predominant element in the patient’s symptoms and most of the back pain could be originating form other spinal structures. The aim of our prospective cohort study is to show whether or not provocative discography plays any significant role before TDR and to define that role.

Methods: Twenty patients (11 females and 9 males) had “Prodisc” TDR. Mean age = 38.5 years (range: 20–56). All patients had mechanical low back pain with degenerative disc disease diagnosed by MRI scan. 65% (N=13) had radicular pain as well. The mean duration of back pain = 66.9 months (range: 16–240). Pre-operative provocative discography was performed in all cases. The clinical outcome was assessed by comparing the preoperative SF36-v2, ODI and VAS scores’ means to the 3, 6, 12 and 24 months post-operative ones and also comparing the last follow up SF36-v2 scores with the, age and sex adjusted, normative data for the general UK population obtained from the Oxford Healthy Lifestyle Survey III. All patients were followed up for a minimum of 2 years.

Results: 90% (N=18) experienced a clinically significant improvement of their back pain (MCID for SF36-v2 scales=1SD, ODI=10 points and VAS=2 points). There has been a statistically significant improvement in the follow up outcome measures (P< 0.05) at 3, 6, 12 and 24 mths. SF 36-v2 scores of 15% of patients (N=3) reached or exceeded the normative values for the UK general population.

Conclusion: Provocative discography is an important diagnostic tool before TDR. It is the only dynamic method to diagnose discogenic pain and is indispensable to exclude the painless levels in cases of multilevel disc degeneration.

Introduction: The use of an ejection seat to escape from a stricken aircraft is associated with the exposure of significant forces. These vertical accelerative forces on the body are in the order of 15–25G with rates of onset of up to 250G per second. Therefore, it is common to see vertical compression fractures, mainly in the thoracolumbar region. Although most vertebral fractures are evident on plain radiographs, subtle spinal injuries elsewhere may not be immediately apparent.

Aim: A prospective study to evaluate for the presence of occult spinal injuries using MRI following aircraft ejection.

Methods: Between 1996 and 2003, 22 ejectees from 18 aircrafts, mean age 32 years (range 24 to 48), were admitted to a regional spinal unit for comprehensive evaluation of their injuries that included whole spine radiographs and Magnetic Resonance Imaging (T1, T2 weighted and STIR sagittal sequences). All ejections occurred within the ejection envelope and were flying below 2000 ft (mean 460 feet) and below 500 knots airspeed (mean 275 knots).

Results: All 5 ejectees (23%) with vertebral compression fractures, one at T6 and 4 in thoracolumbar region, had pain and tenderness in the appropriate area of the spine that was evidently detected on plain radiographs. 3 of these patients with a thoracolumbar fracture (AO A3.3) had more than 50% canal compromise and more than 30 degrees angular kyphosis underwent surgery. Neurological compromise consisting of acute cauda equina syndrome occurred in one patient with a L2 AO A3.3 fracture. More importantly 10 ejectees (45%) had MRI evidence totalling 21 occult thoracic and lumbar vertebral fractures. 4 ejectees had a single occult fracture, 4 had double, 1 had 3 and 1 had 6 occult fractures.

Conclusion: This study confirms the high incidence of occult vertebral injuries following vertical acceleration insult to the spine consequent to emergency aircraft ejection. Once life-saving priority measures have taken place MRI of the entire spine remains mandatory as part the comprehensive evaluation of the patient. Early use of MRI scanning in the management will significantly increase an ejectee’s safe return to flying duties.

We report a consecutive series of 200 patients who underwent Dynesys flexible stabilisation in the management of intractable lower back pain.

Methods: Patients were only accepted for the study if exhaustive conservative management had failed. They underwent operation between September 2000 and March 2003. Patients were divided into two groups:

Group 1 - Cases where implantation was used as an adjunct to other procedures including decompression, discectomy, or posterior lumbar interbody fusion. (32 male, 36 female, Mean age 56years (range 31–85)).

Group 2 - Patients with back pain and/or sciatica in which no other procedure was used. (65 male 67 female, Mean age 58years (range 27–86))

All patients were profiled prospectively using the Oswestry Disability Index (ODI), SF36 and Visual Analogue Scale (VAS). Patients were reviewed post-operatively using the same measures at 3, 6 & 12 months, and yearly thereafter. Follow-up was 95% at 2 to 5 years.

Results: Group 1 – Mean ODI fell from 54 pre-op to 24 at four years

Group 2 – Mean ODI fell from 49 pre-op to 28 at four years

Similar trends were observed in both groups with a fall in VAS and improvement in SF36.

Discussion: Indications can only be defined following clinical outcome. Perceived indications were based on contemporary understanding of the biomechanical effects of the construct. Further investigation of these variables is clearly desirable. Screw failures (15%) have detracted from the overall success. The virtue of flexible stabilisation over fusion includes avoidance of domino effect, reversibility and possible healing of a painful segment. The key issue is whether it is as effective and this requires prospective randomised controlled investigation, both against fusion, and conservative management. We feel our results in this difficult group of patients are reasonable and continue to use it in our practice.

Introduction Dynesys flexible stabilisation was developed by Giles Dubois in 1992, and first used in 1994 (1). Our unit has undertaken 375 operations to date. We report a consecutive series of 200 patients who underwent Dynesys flexible stabilisation in the management of intractable lower back pain.

Methods Access to our spinal service is exclusively from a back assessment centre run by a triaging nurse practitioner who works closely with the senior author. Conservative treatment is arranged by the centre, and includes physiotherapy to the point of failure. Patients were only accepted for the study if exhaustive conservative management had failed. They underwent operation by the senior author between September 2000 and March 2003. Patients were divided into two groups: Group 1 – Cases where implantation was used as an adjunct to other procedures including decompression, discectomy, or posterior lumbar interbody fusion. (32 male, 36 female, Mean age 56years (range 31–85)) Group 2 – Patients with back pain and/or sciatica in which no other procedure was used. (65 male 67 female, Mean age 58years (range 27–86)) All patients were profiled prospectively using the Oswestry Disability Index (ODI), SF36 and Visual Analogue Scale (VAS). Patients were reviewed post-operatively using the same measures at 3, 6 and 12 months, and yearly thereafter. Follow-up was 95% at 2 to 5 years.

Results Group 1 – Mean ODI fell from 54 pre-op to 24 at four years. Mean SF36 improved from 43 pre-op to 56 at four years Group 2 – Mean ODI fell from 49 pre-op to 28 at four years. Mean SF36 improved from 40 pre-op to 62 at four years. Similar trends were observed in both groups at five years with these favourable scores tending back towards pre-operative levels. Screw failures, either loosening or fracture, occurred at a rate of 15% over the follow-up period.

Discussion Our results support the use of flexible stabilisation as an alternative to spinal fusion. There is currently no consensus on absolute indications for the procedure however. Such indications can only be defined following clinical outcome. Perceived indications were based on contemporary understanding of the biomechanical effects of the construct. Further investigation of these variables is clearly desirable. Screw failures (15%) have detracted from the overall success, although the relationship between such failures and poor outcomes is complex and difficult to elucidate at the current time. The virtue of flexible stabilisation over fusion includes avoidance of domino effect, reversibility and possible healing of a painful segment. The key issue is whether flexible stabilisation is as effective and this requires prospective randomised controlled investigation, both against fusion, and against conservative management. We feel our results in this difficult group of patients are reasonable and continue to use it in our practice.

We report a consecutive series of 352 patients with back pain treated by Dynesys flexible stabilisation between July 2000 and November 2004, to include perceived indications, surgical techniques and complications. A detailed analysis of the first 120 cases with minimum follow up of 2 years is included. Our unit has undertaken 352 operations to date, and this communication reports all cases. Follow up is to 48 months.

All patients were profiled prospectively using the Oswestry Disability Index, Euroquol, SF36, Pain analogue scale, Pain chart and modified Zung. The same measuring instruments were used at review for which follow up was 100%

The procedure involves paired bilateral pedicle screw instrumentation above and below the level of perceived pathology, with each screw pair connected by load relieving carbopolyurethane flexible spacers, in conjunction with a tension band polyethylene cord passed through the spacer. This construct is then held under tension with screws in the main pedicle screws.

All patients are profiled at entry to the hospital service using a proforma which includes the measures outlined above. Conservative treatment is arranged by the centre, and includes physiotherapy to the point of failure. All our cases have failed conservative treatment before enrolling for surgery.

There was significant improvement in symptoms for most of the patients in the series. However clear patterns emerged as to those cases in which Dynesys is contra-indicated.

This is the largest series of cases reviewed so far in the literature.