Neurogenic
1. A description is given of historical discoveries relating to intermittent
Aims. Patients may present with concurrent symptomatic osteoarthritis (OA) of the hip and degenerative disorders of the lumbar spine, with surgical treatment being indicated for both. Whether arthroplasty of the hip or spinal surgery should be performed first remains uncertain. Materials and Methods. Clinical scenarios were devised for a survey asking the preferred order of surgery and the rationale for this decision for five fictional patients with both OA of the hip and degenerative lumbar disorders. These were symptomatic OA of the hip and: 1) lumbar spinal stenosis with neurological
Vascular compromise due to arterial injury is a rare but serious complication of a proximal humeral fracture. The aims of this study were to report its incidence in a large urban population, and to identify clinical and radiological factors which are associated with this complication. We also evaluated the results of the use of our protocol for the management of these injuries. A total of 3,497 adult patients with a proximal humeral fracture were managed between January 2015 and December 2022 in a single tertiary trauma centre. Their mean age was 66.7 years (18 to 103) and 2,510 (72%) were female. We compared the demographic data, clinical features, and configuration of those whose fracture was complicated by vascular compromise with those of the remaining patients. The incidence of vascular compromise was calculated from national population data, and predictive factors for its occurrence were investigated using univariate analysis.Aims
Methods
The aim of this study was to reassess the rate of neurological, psoas-related, and abdominal complications associated with L4-L5 lateral lumbar interbody fusion (LLIF) undertaken using a standardized preoperative assessment and surgical technique. This was a multicentre retrospective study involving consecutively enrolled patients who underwent L4-L5 LLIF by seven surgeons at seven institutions in three countries over a five-year period. The demographic details of the patients and the details of the surgery, reoperations and complications, including femoral and non-femoral neuropraxia, thigh pain, weakness of hip flexion, and abdominal complications, were analyzed. Neurological and psoas-related complications attributed to LLIF or posterior instrumentation and persistent symptoms were recorded at one year postoperatively.Aims
Methods
1. The syndrome of spinal stenosis is due to compression of the cauda equina from structural narrowing of the lumbar spinal canal. 2. Patients with this syndrome present symptoms of cauda equina
Symptoms due to a supracondylar spur of the humerus, although rare, are common enough to make it the subject of routine examination of a patient with pain and disturbance of sensibility of the hand. It can mimic the carpal tunnel syndrome; it may produce ulnar nerve symptoms. Irritation or compression of either the brachial artery or, if there is a high division of it, the ulnar artery, may cause episodes of ischaemic pain in the forearm. The clinical features of a supracondylar spur causing symptoms are: symptoms of median nerve compression; forearm
Between 1948 and 1975 147 patients were treated surgically for developmental stenosis of the lumbar vertebral canal, measurement of the mid-sagittal diameters in the whole area of stenosis being performed in 116 patients. Ninety-two of these patients were followed up for periods varying between one and twenty years. About two-thirds were completely relieved fo symptoms and signs. Sciatica and intermittent
The syndromes associated with a narrow lumbar spinal canal are described and discussed. In thirteen cases two main groups were evident, the larger group having mainly backache and root pain, the smaller group having intermittent
Bone-marrow transplantation has increased the survival of patients with mucopolysaccharidosis-I. We describe the spinal problems and their management in 12 patients with this disorder who have been followed up for a mean of 4.5 years since transplantation. High lumbar kyphosis was seen in ten patients which was associated with thoracic scoliosis in one. Isolated thoracic scoliosis was seen in another. One patient did not have any significant problems in the thoracic or lumbar spine but had odontoid hypoplasia, which was also seen in three other children. Four of the eight patients in whom MRI of the cervical spine had been performed had abnormal soft tissue around the tip of the odontoid. Neurological problems were seen in two patients. In one it was caused by cord compression in the lower dorsal spine 9.5 years after posterior spinal fusion for progressive kyphosis, and in the other by angular kyphosis with thecal indentation in the high thoracic spine associated with symptoms of spinal
To determine the effectiveness of prone traction radiographs in predicting postoperative slip distance, slip angle, changes in disc height, and lordosis after surgery for degenerative spondylolisthesis of the lumbar spine. A total of 63 consecutive patients with a degenerative spondylolisthesis and preoperative prone traction radiographs obtained since 2010 were studied. Slip distance, slip angle, disc height, segmental lordosis, and global lordosis (L1 to S1) were measured on preoperative lateral standing radiographs, flexion-extension lateral radiographs, prone traction lateral radiographs, and postoperative lateral standing radiographs. Patients were divided into two groups: posterolateral fusion or posterolateral fusion with interbody fusion.Aims
Methods
The aim of this study was to determine the influence of developmental spinal stenosis (DSS) on the risk of re-operation at an adjacent level. This was a retrospective study of 235 consecutive patients who had undergone decompression-only surgery for lumbar spinal stenosis and had a minimum five-year follow-up. There were 106 female patients (45.1%) and 129 male patients (54.9%), with a mean age at surgery of 66.8 years (Aims
Patients and Methods
The aim of this study was to investigate the clinical and radiographic
outcomes of microendoscopic laminotomy in patients with lumbar stenosis
and concurrent degenerative spondylolisthesis (DS), and to determine
the effect of this procedure on spinal stability. A total of 304 consecutive patients with single-level lumbar
DS with concomitant stenosis underwent microendoscopic laminotomy
without fusion between January 2004 and December 2010. Patients
were divided into two groups, those with and without advanced DS
based on the degree of spondylolisthesis and dynamic instability. A
total of 242 patients met the inclusion criteria. There were 101
men and 141 women. Their mean age was 68.1 years (46 to 85). Outcome
was assessed using the Japanese Orthopaedic Association and Roland
Morris Disability Questionnaire scores, a visual analogue score
for pain and the Short Form Health-36 score. The radiographic outcome
was assessed by measuring the slip and the disc height. The clinical
and radiographic parameters were evaluated at a mean follow-up of
4.6 years (3 to 7.5).Aims
Patients and Methods
We compared the clinical and radiological outcomes of using a
polyetheretherketone cage with (TiPEEK) and without a titanium coating
(PEEK) for instrumented transforaminal lumbar interbody fusion (TLIF). We conducted a randomised clinical pilot trial of 40 patients
who were scheduled to undergo a TLIF procedure at one or two levels
between L2 and L5. The Oswestry disability index (ODI), EuroQoL-5D,
and back and leg pain were determined pre-operatively, and at three,
six, and 12 months post-operatively. Fusion rates were assessed
by thin slice CT at three months and by functional radiography at
12 months.Aims
Materials and Methods
The purpose of this study was to investigate the prevalence of
sarcopenia and to examine its impact on patients with degenerative
lumbar spinal stenosis (DLSS). This case-control study included two groups: one group consisting
of patients with DLSS and a second group of control subjects without
low back or neck pain and related leg pain. Five control cases were
randomly selected and matched by age and gender (n = 77 cases and
n = 385 controls) for each DLSS case. Appendicular muscle mass,
hand-grip strength, sit-to-stand test, timed up and go (TUG) test,
and clinical outcomes, including the Oswestry Disability Index (ODI)
scores and the EuroQol EQ-5D were compared between the two groups.Aims
Patients and Methods
This study aimed to determine the relationship between pedicle-lengthening
distance and bulge-canal volume ratio in cases of lumbar spinal
stenosis, to provide a theoretical basis for the extent of lengthening
in pedicle-lengthening osteotomies. Three-dimensional reconstructions of CT images were performed
for 69 patients (33 men and 36 women) (mean age 49.96 years; 24
to 81). Simulated pedicle-lengthening osteotomies and disc bulge
and spinal canal volume calculations were performed using Mimics
software. Aims
Methods
The aims of this study were to evaluate the clinical and radiological
outcomes of instrumented posterolateral fusion (PLF) performed in
patients with rheumatoid arthritis (RA). A total of 40 patients with RA and 134 patients without RA underwent
instrumented PLF for spinal stenosis between January 2003 and December
2011. The two groups were matched for age, gender, bone mineral
density, the history of smoking and diabetes, and number of fusion
segments. The clinical outcomes measures included the visual analogue scale
(VAS) and the Korean Oswestry Disability Index (KODI), scored before
surgery, one year and two years after surgery. Radiological outcomes
were evaluated for problems of fixation, nonunion, and adjacent
segment disease (ASD). The mean follow-up was 36.4 months in the RA
group and 39.1 months in the non-RA group.Aims
Methods
Pain catastrophising is an adverse coping mechanism,
involving an exaggerated response to anticipated or actual pain. The purpose of this study was to investigate the influence of
pain ‘catastrophising’, as measured using the pain catastrophising
scale (PCS), on treatment outcomes after surgery for lumbar spinal
stenosis (LSS). A total of 138 patients (47 men and 91 women, mean age 65.9;
45 to 78) were assigned to low (PCS score <
25, n = 68) and high
(PCS score ≥ 25, n = 70) PCS groups. The primary outcome measure
was the Oswestry Disability Index (ODI) 12 months after surgery.
Secondary outcome measures included the ODI and visual analogue
scale (VAS) for back and leg pain, which were recorded at each assessment
conducted during the 12-month follow-up period The overall changes in the ODI and VAS for back and leg pain
over a 12-month period were significantly different between the
groups (ODI, p <
0.001; VAS for back pain, p <
0.001; VAS
for leg pain, p = 0.040). The ODI and VAS for back and leg pain
significantly decreased over time after surgery in both groups (p
<
0.001 for all three variables). The patterns of change in the
ODI and VAS for back pain during the follow-up period significantly
differed between the two groups, suggesting that the PCS group is
a potential treatment moderator. However, there was no difference
in the ODI and VAS for back and leg pain between the low and high
PCS groups 12 months after surgery. In terms of minimum clinically important differences in ODI scores
(12.8), 22 patients (40.7%) had an unsatisfactory surgical outcome
in the low PCS group and 16 (32.6%) in the high PCS group. There
was no statistically significant difference between the two groups
(p = 0.539). Pre-operative catastrophising did not always result in a poor
outcome 12 months after surgery, which indicates that this could
moderate the efficacy of surgery for LSS. Cite this article:
There have been very few reports in the literature of gout and pseudogout of the spine. We describe six patients who presented with acute sciatica attributable to spinal stenosis with cyst formation in the facet joints. Cytopathological studies confirmed the diagnosis of crystal arthropathy in each case. Specific formation of a synovial cyst was identified pre-operatively by MRI in five patients. In the sixth, the diagnosis was made incidentally during decompressive surgery. Surgical decompression alone was undertaken in four patients. In one with an associated degenerative spondylolisthesis, an additional intertransverse fusion was performed. Another patient had previously undergone a spinal fusion adjacent to the involved spinal segment, and spinal stabilisation was undertaken as well as a decompression. In addition to standard histological examination material was sent for examination under polarised light which revealed deposition of urate or calcium pyrophosphate dihydrate crystals in all cases. It is not possible to diagnose gout and pseudogout of the spine by standard examination of a fixed specimen. However, examining dry specimens under polarised light suggests that crystal arthropathy is a significant aetiological factor in the development of symptomatic spinal stenosis associated with cyst formation in a facet joint.
The brachial artery is rarely injured after closed dislocation of the elbow. We describe an unusual variation of this injury, namely, a delayed thrombosis of the brachial artery after a closed dislocation sustained during a low-energy fall. This has not previously been described in the English literature, but may be more common than this suggests. We stress the importance of a thorough neurovascular examination and vigilance in regard to this potentially disastrous complication.
The optimal timing of total knee replacement
(TKR) in patients with osteoarthritis, in relation to the severity
of disease, remains controversial. This prospective study was performed
to investigate the effect of the severity of osteoarthritis and
other commonly available pre- and post-operative clinical parameters
on the clinical outcome in a consecutive series of cemented TKRs.
A total of 176 patients who underwent unilateral TKR were included
in the study. Their mean age was 68 years (39 to 91), 63 (36%) were
male and 131 knees (74%) were classified as grade 4 on the Kellgren–Lawrence
osteoarthritis scale. A total of 154 patients (87.5%) returned for
clinical review 12 months post-operatively, at which time the outcome
was assessed using the Knee Society score. A low radiological severity of osteoarthritis was not associated
with pain 12 months post-operatively. However, it was significantly
associated with an inferior level of function (p = 0.007), implying
the need for increased focus on all possible reasons for pain in
the knee and the forms of conservative treatment which are available
for patients with lower radiological severity of osteoarthritis. Cite this article:
We describe a modified technique of micro-decompression of the lumbar spine involving the use of an operating microscope, a malleable retractor and a high-speed burr, which allows decompression to be performed on both sides of the spine through a unilateral, hemi-laminectomy approach. The first 100 patients to be treated with this technique have been evaluated prospectively using a visual analogue score for sciatica and back pain, the MacNab criteria for patient satisfaction, and functional assessment with the Oswestry Disability Index. After a period of follow-up from 12 months to six years and four months, sciatica had improved in 90 patients and back pain in 84 patients. Their result was graded as good or excellent by 82 patients according to the MacNab criteria, and 75 patients had subjective improvement in their walking distance. Late instability developed in four patients. Lumbar micro-decompression has proved to be safe, with few complications. Postoperative instability requiring fusion was uncommon, and less than using traditional approaches in published series.
We compared two management strategies for the perfused but pulseless hand after stabilisation of a Gartland type III supracondylar fracture. We identified 19 patients, of whom 11 were treated conservatively after closed reduction (group 1). Four required secondary exploration, of whom three had median and/or anterior interosseus nerve palsy at presentation. All four were found to have tethering or entrapment of both nerve and vessel at the fracture site. Only two regained patency of the brachial artery, and one patient has a persistent neurological deficit. In six of the eight patients who were explored early (group 2) the vessel was tethered at the fracture site. In group 2 four patients also had a nerve palsy at presentation and were similarly found to have tethering or entrapment of both the nerve and the vessel. The patency of the brachial artery was restored in all six cases and their neurological deficits recovered completely. We would recommend early exploration of a Gartland type III supracondylar fracture in patients who present with a coexisting anterior interosseous or median nerve palsy, as these appear to be strongly predictive of nerve and vessel entrapment.
Little information is available about the incidence
and outcome of incidental dural tears associated with microendoscopic
lumbar decompressive surgery. We prospectively examined the incidence
of dural tears and their influence on the outcome six months post-operatively
in 555 consecutive patients (mean age 47.4 years (13 to 89)) who
underwent this form of surgery. The incidence of dural tears was
5.05% (28/555). The risk factors were the age of the patient and
the procedure of bilateral decompression via a unilateral approach.
The rate of recovery of the Japanese Orthopaedic Association score
in patients with dural tears was significantly lower than that in
those without a tear (77.7% Cite this article:
Total hip replacement (THR) is a very common
procedure undertaken in up to 285 000 Americans each year. Patient
satisfaction with THR is very high, with improvements in general
health, quality of life, and function while at the same time very
cost effective. Although the majority of patients have a high degree
of satisfaction with their THR, 27% experience some discomfort,
and up to 6% experience severe chronic pain. Although it can be
difficult to diagnose the cause of the pain in these patients, this
clinical issue should be approached systematically and thoroughly.
A detailed history and clinical examination can often provide the
correct diagnosis and guide the appropriate selection of investigations, which
will then serve to confirm the clinical diagnosis made. Cite this article:
There have been a few reports of patients with
a combination of lumbar and thoracic spinal stenosis. We describe six
patients who suffered unexpected acute neurological deterioration
at a mean of 7.8 days (6 to 10) after lumbar decompressive surgery.
Five had progressive weakness and one had recurrent pain in the
lower limbs. There was incomplete recovery following subsequent
thoracic decompressive surgery. The neurological presentation can be confusing. Patients with
compressive myelopathy due to lower thoracic lesions, especially
epiconus lesions (T10 to T12/L1 disc level), present with similar
symptoms to those with lumbar radiculopathy or cauda equina lesions.
Despite the rarity of this condition we advise that patients who
undergo lumbar decompressive surgery for stenosis should have sagittal
whole spine MRI studies pre-operatively to exclude proximal neurological
compression. Cite this article:
We retrospectively examined the prevalence and
natural history of asymptomatic lumbar canal stenosis in patients treated
surgically for cervical compressive myelopathy in order to assess
the influence of latent lumbar canal stenosis on the recovery after
surgery. Of 214Â patients who had undergone cervical laminoplasty
for cervical myelopathy, we identified 69 (32%) with myelographically
documented lumbar canal stenosis. Of these, 28Â (13%) patients with
symptomatic lumbar canal stenosis underwent simultaneous cervical
and lumbar decompression. Of the remaining 41 (19%) patients with
asymptomatic lumbar canal stenosis who underwent only cervical surgery,
39 were followed up for ≥ 1 year (mean 4.9 years (1 to 12)) and
were included in the analysis (study group). Patients without myelographic
evidence of lumbar canal stenosis, who had been followed up for ≥ 1
year after the cervical surgery, served as controls (135 patients;
mean follow-up period 6.5 years (1 to 17)). Among the 39 patients
with asymptomatic lumbar canal stenosis, seven had lumbar-related
leg symptoms after the cervical surgery. Kaplan–Meier analysis showed that 89.6% (95% confidence interval
(CI) 75.3 to 96.0) and 76.7% (95% CI 53.7 to 90.3) of the patients
with asymptomatic lumbar canal stenosis were free from leg symptoms
for three and five years, respectively. There were no significant
differences between the study and control groups in the recovery
rate measured by the Japanese Orthopaedic Association score or improvement
in the Nurick score at one year after surgery or at the final follow-up. These results suggest that latent lumbar canal stenosis does
not influence recovery following surgery for cervical myelopathy;
moreover, prophylactic lumbar decompression does not appear to be
warranted as a routine procedure for coexistent asymptomatic lumbar
canal stenosis in patients with cervical myelopathy, when planning
cervical surgery.
We examined the differences in post-operative
functional disability and patient satisfaction between 56 patients who
underwent a lumbar fusion at three or more levels for degenerative
disease (group I) and 69 patients, matched by age and gender, who
had undergone a one or two level fusion (group II). Their mean age
was 66 years (49 to 84) and the mean follow-up was 43 months (24
to 65). The mean pre-operative Oswestry Disability Index (ODI) and visual
analogue scale (VAS) for back and leg pain, and the mean post-operative
VAS were similar in both groups (p >
 0.05), but post-operatively
the improvement in ODI was significantly less in group I (40.6%)
than in group II (49.5%) (p <
0.001). Of the ten ODI items, patients
in group I showed significant problems with lifting, sitting, standing,
and travelling (p <
0.05). The most significant differences in
the post-operative ODI were observed between patients who had undergone
fusion at four or more levels and those who had undergone fusion
at less than four levels (p = 0.005). The proportion of patients
who were satisfied with their operations was similar in groups I
and II (72.7% and 77.0%, respectively) (p = 0.668). The mean number
of fused levels was associated with the post-operative ODI (r =
0.266, p = 0.003), but not with the post-operative VAS or satisfaction
grade (p >
0.05). Post-operative functional disability was more
severe in those with a long-level lumbar fusion, particularly at
four or more levels, but patient satisfaction remained similar for
those with both long- and short-level fusions.
Fracture of a pedicle is a rare complication of spinal instrumentation using pedicular screws, but it can lead to instability and pain and may necessitate extension of the fusion. Osteosynthesis of the fractured pedicle by cerclage-wire fixation and augmentation of the screw fixation by vertebroplasty or temporary elongation of the fixation, allows stabilisation without sacrifice of the adjacent healthy segment. We describe three patients who developed a fracture of the pedicle in the most caudal instrumented vertebra early after lumbar spinal fusion. During revision surgery the pedicles were reduced and secured by a soft cerclage wire bilaterally. Fusion was obtained at the site of the primary instrumentation and healing of the pedicles was achieved. Cerclage wiring of the fractured pedicle seems to be safe and avoids permanent extension of the fusion without the sacrifice of an otherwise healthy segment.
This annotation discusses the findings of two papers in the current issue describing the management of the neurovascular complications of supracondylar fractures of the humerus in childhood, with particular reference to the indications for and the timing of exploration of the brachial artery and the affected nerves.
In order to determine the epidemiology of adult scoliosis in the elderly and to analyse the radiological parameters and symptoms related to adult scoliosis, we carried out a prospective cross-sectional radiological study on 1347 adult volunteers. There were 615 men and 732 women with a mean age of 73.3 years (60 to 94), and a mean Cobb angle of 7.55° ( In our study, 478 subjects met the definition of scoliosis (Cobb angle ≥10°) showing a prevalence of 35.5%. There was a significant difference in the epidemiological distribution and prevalence between the age and gender groups. The older adults showed a larger prevalence and more severe scoliosis, more prominent in women (p = 0.004). Women were more affected by adult scoliosis and showed more linear correlation with age (p <
0.001). Symptoms were more severe in those with scoliosis than in the normal group, but were similar between the mild, moderate and severe scoliosis groups (p = 0.224) and between men and women (p = 0.231). Adult scoliosis showed a significant relationship with lateral listhesis, vertebral rotation, lumbar hypolordosis, sagittal imbalance and a high level of the L4–5 disc (p <
0.0001, p <
0.0001, p = 0.002, p = 0.002, p <
0.0001 respectively). Lateral listhesis, lumbar hypolordosis and sagittal imbalance were related to symptoms (p <
0.0001, p = 0.001, p <
0.0001 respectively).
We describe a case of lumbosacral plexopathy caused by an isolated aneurysm of the common iliac artery. The patient presented with worsening low back pain, progressive numbness and weakness of the right leg in the L2-L4 distribution. This had previously been diagnosed as sciatica. A CT scan showed an aneurysm of the right common iliac artery which measured 8 cm in diameter. Despite being listed for emergency endovascular stenting, the aneurysm ruptured and the patient died. It is important to distinguish a lumbosacral plexopathy from sciatica and to bear in mind its treatable causes which include aneurysms of the common and internal iliac arteries.
Giant-cell tumour of the synovium is known to affect the fingers or toes of adults. It has seldom been described in the spine and rarely in the thoracic vertebrae or in a child. The lesions of giant-cell tumour of the synovium have a classical radiological appearance, but require a high index of suspicion for correct recognition. Unlike giant-cell tumour of the synovium at other well-known sites, spinal lesions lack the characteristic papillary architecture, thereby raising other diagnostic possibilities. We describe a giant-cell tumour of the synovium of the left facet joint of a thoracic vertebra in a nine-year-old girl. The tumour was treated successfully by surgical excision.
Inflammatory pseudotumours occasionally occur after metal-on-metal hip resurfacing and often lead to revision. Our aim was to determine the severity of this complication by assessing the outcome of revision in these circumstances and by comparing this with the outcome of other metal-on-metal hip resurfacing revisions as well as that of matched primary total hip replacements. We identified 53 hips which had undergone metal-on-metal hip resurfacing and required revision at a mean of 1.59 years (0.01 to 6.69) after operation. Of these, 16 were revised for pseudotumours, 21 for fracture and 16 for other reasons. These were matched by age, gender and diagnosis with 103 patients undergoing primary total hip replacement with the Exeter implant. At a mean follow-up of three years (0.8 to 7.2) the outcome of metal-on-metal hip resurfacing revision for pseudotumour was poor with a mean Oxford hip score of 20.9 ( The outcome of revision for pseudotumour is poor and consideration should be given to early revision to limit the extent of the soft-tissue destruction. The outcome of resurfacing revision for other causes is good.
We describe two patients in whom poor healing after chemical ablation for ingrown toenails unmasked significant vascular disease of the lower extremities. We have found no similar reports in the English language literature.
Evaluation of patients with painful total knee replacement requires a thorough clinical examination and relevant investigations in order to reach a diagnosis. Awareness of the common and uncommon problems leading to painful total knee replacement is useful in the diagnostic approach. This review article aims to act as a guide to the evaluation of patients with painful total knee replacement.
We carried out an MRI study of the lumbar spine in 15 patients with achondroplasia to evaluate the degree of stenosis of the canal. They were divided into asymptomatic and symptomatic groups. We measured the sagittal canal diameter, the sagittal cord diameter, the interpedicular distance at the mid-pedicle level and the cross-sectional area of the canal and spinal cord at mid-body and mid-disc levels. The MRI findings showed that in achondroplasia there was a significant difference between the groups in the cross-sectional area of the body canal at the upper lumbar levels. Patients with a narrower canal are more likely to develop symptoms of spinal stenosis than others.
This paper reviews the current literature concerning the main clinical factors which can impair the healing of fractures and makes recommendations on avoiding or minimising these in order to optimise the outcome for patients. The clinical implications are described.
We investigated the blood supply of the common peroneal nerve. Dissection of 19 lower limbs, including six with intra-vascular injection of latex, allowed gross and microscopic measurements to be made of the blood supply of the common peroneal nerve in the popliteal fossa. This showed that a long segment of the nerve in the vicinity of the fibular neck contained only a few intraneural vessels of fine calibre. By contrast, the tibial nerve received an abundant supply from a constant series of vessels arising directly from the popliteal and posterior tibial arteries. The susceptibility of the common peroneal nerve to injury from a variety of causes and its lack of response to operative treatment may be explained by the tenuous nature of its intrinsic blood supply.
Discogenic low back pain is a common cause of disability, but its pathogenesis is poorly understood. We collected 19 specimens of lumbar intervertebral discs from 17 patients with discogenic low back pain during posterior lumbar interbody fusion, 12 from physiologically ageing discs and ten from normal control discs. We investigated the histological features and assessed the immunoreactive activity of neurofilament (NF200) and neuropeptides such as substance P (SP) and vasoactive-intestinal peptide (VIP) in the nerve fibres. The distinct histological characteristic of the painful disc was the formation of a zone of vascularised granulation tissue from the nucleus pulposus to the outer part of the annulus fibrosus along the edges of the fissures. SP-, NF- and VIP-immunoreactive nerve fibres in the painful discs were more extensive than in the control discs. Growth of nerves deep into the annulus fibrosus and nucleus pulposus was observed mainly along the zone of granulation tissue in the painful discs. This suggests that the zone of granulation tissue with extensive innervation along the tears in the posterior part of the painful disc may be responsible for causing the pain of discography and of discogenic low back pain.