Aims. 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. Methods. 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. Results. The mean changes in segmental lordosis and global lordosis were 7.1° (SD 6.7°) and 2.9° (SD 9.9°) respectively for the interbody fusion group, and 0.8° (SD 5.1°) and -0.4° (SD 10.1°) respectively for the posterolateral fusion-only group. Segmental lordosis (ρ = 0.794, p < 0.001) corrected by interbody fusion correlated best with prone traction radiographs. Global lumbar lordosis (ρ = 0.788, p < 0.001) correlated best with the interbody fusion group and preoperative lateral standing radiographs. The least difference in slip distance (-0.3 mm (SD 1.7 mm), p < 0.001), slip angle (0.9° (SD 5.2°), p < 0.001), and disc height (0.02 mm (SD 2.4 mm), p < 0.001) was seen between prone traction and postoperative radiographs. Regression analyses suggested that prone traction parameters best predicted correction of slip distance (Corrected Akaike’s Information Criterion (AICc) = 37.336) and disc height (AICc = 58.096), while correction of slip angle (AICc = 26.453) was best predicted by extension radiographs. Receiver operating characteristic (ROC) cut-off showed, with 68.3% sensitivity and 64.5% specificity, that to achieve a 3.0° increase in segmental lordotic angle, patients with a prone traction disc height of 8.5 mm needed an interbody fusion. Conclusion. Prone traction radiographs best predict the slip distance and disc height correction achieved by interbody fusion for lumbar degenerative spondylolisthesis. To achieve this maximum correction, interbody fusion should be undertaken if a disc height of more than 8.5 mm is attained on preoperative prone traction radiographs. Level of Evidence: Level II Prognostic Study. Cite this article: Bone Joint J 2020;102-B(8):1062–1071

Aims. The aims of this study were first, to determine if adding fusion to a decompression of the lumbar spine for spinal stenosis decreases the rate of radiological restenosis and/or proximal adjacent level stenosis two years after surgery, and second, to evaluate the change in vertebral slip two years after surgery with and without fusion. Methods. The Swedish Spinal Stenosis Study (SSSS) was conducted between 2006 and 2012 at five public and two private hospitals. Six centres participated in this two-year MRI follow-up. We randomized 222 patients with central lumbar spinal stenosis at one or two adjacent levels into two groups, decompression alone and decompression with fusion. The presence or absence of a preoperative spondylolisthesis was noted. A new stenosis on two-year MRI was used as the primary outcome, defined as a dural sac cross-sectional area ≤ 75 mm. 2. at the operated level (restenosis) and/or at the level above (proximal adjacent level stenosis). Results. A total of 211 patients underwent surgery at a mean age of 66 years (69% female): 103 were treated by decompression with fusion and 108 by decompression alone. A two-year MRI was available for 176 (90%) of the eligible patients. A new stenosis at the operated and/or adjacent level occurred more frequently after decompression and fusion than after decompression alone (47% vs 29%; p = 0.020). The difference remained in the subgroup with a preoperative spondylolisthesis, (48% vs 24%; p = 0.020), but did not reach significance for those without (45% vs 35%; p = 0.488). Proximal adjacent level stenosis was more common after fusion than after decompression alone (44% vs 17%; p < 0.001). Restenosis at the operated level was less frequent after fusion than decompression alone (4% vs 14%; p = 0.036). Vertebral slip increased by 1.1 mm after decompression alone, regardless of whether a preoperative spondylolisthesis was present or not. Conclusion. Adding fusion to a decompression increased the rate of new stenosis on two-year MRI, even when a spondylolisthesis was present preoperatively. This supports decompression alone as the preferred method of surgery for spinal stenosis, whether or not a degenerative spondylolisthesis is present preoperatively. Cite this article: Bone Joint J 2022;104-B(12):1343–1351

A review of the current literature shows that there is a lack of consensus regarding the treatment of spondylolysis and spondylolisthesis in children and adolescents. Most of the views and recommendations provided in various reports are weakly supported by evidence. There is a limited amount of information about the natural history of the condition, making it difficult to compare the effectiveness of various conservative and operative treatments. This systematic review summarises the current knowledge on spondylolysis and spondylolisthesis and attempts to present a rational approach to the evaluation and management of this condition in children and adolescents

The association between spondylolisthesis and scoliosis was studied in 84 patients who presented during a 30-year period with symptomatic spondylolisthesis. The incidence of scoliosis was 42 per cent, the majority of cases being lumbar or thoracolumbar curves of less than 15 degrees. The incidence was highest in the group of patients with spondylolisthesis at L4--5 where all except one had scoliosis. Scoliosis was present in 47 per cent of patients with dysplastic spondylolisthesis at the lumbosacral junction; in this group, the incidence of scoliosis was greater where the displacement exceeded 25 per cent. The lowest incidence (25 per cent) was found in the group with isthmic spondylolisthesis at the lumbosacral junction. There appeared to be no relationship between excessive lumbar lordosis or tightness of the hamstrings and scoliosis

We performed a case-control study on the influence of oophorectomy on the development of degenerative spondylolisthesis, including a clinical review and determination of serum oestradiol levels. We also compared the radiological appearance of the lumbar spine at L4/5 in patients with and without spondylolisthesis and with and without oophorectomy. Oophorectomy was a risk factor for degenerative spondylolisthesis with an odds ratio of 7.5 (95% confidence interval, 1.6 to 46). The incidence of degenerative spondylolisthesis in 69 oophorectomised patients was about three times higher than in 69 non-oophorectomised matched control subjects. There was also a difference in spinal variation between oophorectomised and non-oophorectomised patients with spondylolisthesis. A high incidence of sagittal-plane orientation of the L4/5 facet and an increase in pedicle-facet angle were seen in both groups and are typical radiological features of this disease. An increase in lumbosacral angle and in disc-space narrowing was seen only in the non-oophorectomised patients with this condition. Our results suggest that the abrupt decrease in oestradiol level caused by oophorectomy may be a predisposing factor in degenerative spondylolisthesis at L4/5

Degenerative spondylolisthesis is four times more common in women than in men. Although this gender difference has long been recognised there has been no explanation for it. We have examined the radiographs and CT scans of 118 patients over the age of 55 years and of a control group under the age of 46 years. Our findings confirmed the presence of more sagittally-orientated facet joints in patients with degenerative spondylolisthesis but did not show that the gender difference can be explained by the morphology of the facet joint. Furthermore, we conclude that the increased angle of the facet joint is the result of arthritic remodelling and not the primary cause of degenerative spondylolisthesis. It is more likely to be due to loss of soft-tissue resilience with subsequent failure of the facet joints which are acting as the last restraints to subluxation

Aims. 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. Patients and Methods. 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). Results. There were no significant differences in the preoperative measurements between the group and no significant differences between the clinical parameters at the final follow-up. The mean percentage slip was 17.1% preoperatively and 17.7% at the final follow-up (p = 0.35). Progressive instability was noted in 13 patients (8.2%) with DS and 6 patients (7.0%) with advanced DS, respectively (p = 0.81). There was radiological evidence of restabilization of the spine in 30 patients (35%) with preoperative instability. The success rate of microendoscopic laminotomy was good/excellent in 166 (69%), fair in 49 (20%) and poor in 27 patients (11%) in both groups. Conclusion. Microendoscopic laminotomy is an effective form of surgical treatment for patients with DS and stenosis. Preservation of the stabilizing structures using this technique prevents postoperative instability. Cite this article: Bone Joint J 2018;100-B:499–506

We have analysed a number of radiological measurements in an attempt to clarify the predisposing factors for degenerative spondylolisthesis of the lumbosacral junction. We identified 57 patients with a slip and a control group of 293 patients without any radiological abnormality apart from age-related changes. The relative thickness of the L5 transverse process, the sacral table angle and the height of the iliac crest were measured and evaluated. The difference in these measurements between men and women was analysed in the control group. We found that the transverse process of L5 was extremely slender, the sacral table more inclined, and the L5 vertebra was less deeply placed in the pelvis in patients with a slip compared with the control group. The differences in these three parameters were statistically significant. We believe that the L5 vertebra is predisposed to slip when these factors act together on a rigidly-stabilised sacrum. This occurs more commonly in women, probably as a result of constitutional differences in the development of the male and female spine

Between March 2000 and February 2006, we carried out a prospective study of 100 patients with a low-grade isthmic spondylolisthesis (Meyerding grade II or below), who were randomised to receive a single-level and instrumented posterior lumbar interbody fusion with either one or two cages. The minimum follow-up was for two years. At this stage 91 patients were available for review. A total of 47 patients received one cage (group 1) and 44 two cages (group 2). The clinical and radiological outcomes of the two groups were compared. There were no significant differences between the two groups in terms of post-operative pain, Oswestry Disability Score, clinical results, complication rate, percentage of post-operative slip, anterior fusion rate or posterior fusion rate. On the other hand, the mean operating time was 144 minutes (100 to 240) for patients in group 1 and 167 minutes (110 to 270) for those in group 2 (p = 0.0002). The mean blood loss up to the end of the first post-operative day was 756 ml (510 to 1440) in group 1 and 817 ml (620 to 1730) in group 2 (p < 0.0001). Our results suggest that an instrumented posterior lumbar interbody fusion performed with either one or two cages in addition to a bone graft around the cage has a low rate of complications and a high fusion rate. The clinical outcomes were good in most cases, regardless of whether one or two cages had been used

Two collagen type IX gene polymorphisms that introduce a tryptophan residue into the protein’s triple-helical domain have been linked to an increased risk of lumbar disc disease. To determine whether a particular subset of symptomatic lumbar disease is specifically associated with these polymorphisms, we performed a prospective case-control study of 107 patients who underwent surgery of the lumbar spine. Patients were assigned to one of five clinical categories (fracture, disc degeneration, disc herniation, spinal stenosis without spondylolisthesis and spinal stenosis with spondylolisthesis) based on history, imaging results, and findings during surgery. Of the 11 tryptophan-positive patients, eight had spinal stenosis with spondylolisthesis and three had disc herniation. The presence of the tryptophan allele was significantly associated with African-American or Asian designation for race (odds ratio 4.61, 95% CI 0.63 to 25.35) and with the diagnosis of spinal stenosis with spondylolisthesis (odds ratio 6.81, 95% CI 1.47 to 41.95). Our findings indicate that tryptophan polymorphisms predispose carriers to the development of symptomatic spinal stenosis associated with spondylolisthesis which requires surgery

A radiographic suvey has been carried out of 147 first-degree relatives of forty-seven patients treated in Edinburgh for spondylolisthesis of the fifth lumbar vertebra; twelve patients had the dysplastic (congenital) type and thirty-five an isthmic defect. The survey identified 19 per cent of relatives with spondylolysis, and index patients with each type of spondylolisthesis had relatives with the opposite type. Index patients with the dysplastic form had a higher proportion of affected relatives (33 per cent) than had those with the isthmic type (15 per cent), but both figures were significantly in excess of the estimated frequency for the general population of under 1 per cent and 5 per cent respectively. Spina bifida occulta at the fifth lumbar or first sacral level or both, and lumbosacral segmental defects were commoner amongst all individuals with spondylolysis than amongst unaffected relatives (dysplastic form 94 per cent, isthmic type 32 per cent, unaffected relatives 7 per cent). However, there was no single instance of a neural tube defect (anencephaly, spina bifida with or without meningocele, other generalised vertebral anomalies or spinal dysraphism) amongst 826 first-, second- or third-degree relatives. It is concluded that the developmental defects of the vertebrae associated with spondylolysis are not aetiologically related to the neural tube defects. The one in three risk of spondylolysis to near relatives of patients with the dysplastic form of spondylolisthesis is emphasised in order that the deformity in their sibs and children can be recognised at any early age

The different methods described in the literature for the reduction of severe spondylolisthesis are reviewed. The case histories of two girls with neurological deficits in their legs due to Grade IV spondylolisthesis are described. Reduction and fusion by the posterior route in a one-stage operation were performed on these patients. For this purpose special instruments have been designed to exert a controlled force on the displaced vertebra in two perpendicular directions. Technical details of the procedure are reported. In both patients intervertebral and posterolateral fusion were carried out. Fusion was successful and redisplacement did not occur. There have been only few descriptions in the literature of a technique that reduces and stabilises spondylolisthesis in one stage. However, only patients with Grade III and IV spondylolisthesis require reduction and in less severe cases fusion without reduction is sufficient

A 48-year old man presented with back pain that was resistant to treatment. An MR scan showed spondylolisthesis at L4-5 and narrowing of the exit foraminae. He had a posterior fusion which did not relieve his symptoms. He continued to have back pain and developed subcutaneous nodules in both forearms. Biopsy from the skin revealed cutaneous sarcoidosis, and one from the lumbar spine showed sarcoidosis granuloma between the bone trabeculae. A CT scan of the abdomen and chest revealed axillary lymphadenopathy, mediastinal enlarged nodes, apical nodular nodes and splenomegaly. The patient was started on large doses of methotrexate and steroids. His angiotensin-converting enzyme and calcium levels returned to normal and the back pain resolved

The long-term results of 17 patients who had had fusion in situ for severe lumbosacral spondylolisthesis are reported. The average follow-up was 14 years with a range of 7 to 20 years. The average age at operation was 16 years. At follow-up seven patients had occasional backache but only one patient had changed his job and no patient had lost any time off work in the previous year. Nine patients felt that their deformity had been improved and all but one patient still rated the results as excellent up to 20 years after the operation. Although all the patients had persistent foreshortening of the trunk only two patients were aware of any cosmetic deformity. There had been no significant increase in forward slip since the previous follow-up examination five years after the operation. There were no late complications nor significant degenerative changes in the lumbar spine. It is concluded that although fusion in situ does little to improve cosmesis very few patients complain about their appearance and that it is a safe and reliable method of treatment for severe spondylolisthesis which has stood the test of time

A clinical study has been made of forty-three patients with symptoms arising from degenerative spondylolisthesis of the lumbar spine. Attention is drawn to the lower average level of the iliac crests in these patients, and to the high incidence of osteoarthritis of the hips. Many patients in this series had been referred specifically for operation and fourteen were so treated. The techniques of decompression and of spinal fusion are discussed. It is concluded that patients with back pain predominant are well treated by corsetry, only a minority needing fusion, and that patients with nerve root involvement or with symptoms of spinal stenosis need decompression. The place of spinal fusion is the main problem, but it seems reasonable, firstly, in younger patients with clear evidence of instability and degenerative change at a single level, and secondly, when radical decompression is judged to increase the risk of instability

Thirty-four bony specimens of isthmic spondylolysis were examined and, in a significant number (32%), stenosis of the intervertebral foramen was noted. Although not emphasised in previous reports, this finding may be an important factor in the aetiology of nerve root compression when this is associated with spondylolysis and spondylolisthesis. Anatomical guidelines for adequate surgical decompression are suggested

We made a retrospective study of 149 children and adolescents with moderate spondylolisthesis (slip less than or equal to 30%), 77 treated by fusion and 72 conservatively at an average follow-up of 13.3 years. Both groups were fully comparable with regard to age at diagnosis, sex distribution (46% girls), and mean slip. The patients who were treated operatively had more pain before treatment and showed more initial progression of the slip. They had better clinical results and less pain at latest review, but the total progression of the slip over the whole follow-up showed no statistical differences between the two groups. Patients with a pseudarthrosis after attempted fusion had had a longer period of postoperative pain, but at the latest review had no more pain than those with sound fusion. None of those treated conservatively came to fusion later and the long-term results in 18 patients who had refused the advised operation were no worse than those for other conservatively treated patients. Our results suggest that a moderate grade of spondylolisthesis in adolescents usually has a benign course. It seems that spontaneous segmental stabilisation occurs as a result of degeneration of the disc at the level of the slip

A series of 123 patients suffering traumatic spondylolisthesis of the axis is reported. This lesion is associated with extension and axial loading injury, and there is a high incidence of injuries of the face or scalp and of associated fractures of the upper cervical spine. There is a low incidence of neurological injury, which seems paradoxical in the presence of what appears to be gross instability, but protection from extremes of flexion and extension may be adequate treatment. Union is usual regardless of displacement. Traction is a safe means of treatment, but early waking in a halo support reduces time in hospital without jeopardizing the result. Operation is needed only for chronic instability with or without pain, and anterior interbody fusion of C2--3 is than preferred in order to preserve rotation at the atlanto-axial joints

This report describes a nine-year-old girl with a spondylolisthesis of the C2 vertebra allowing 14 mm of slip. Her father had very similar vertebral anomalies

Unstable degenerative spondylolisthesis of the cervical spine is very rare. Slip usually occurs at the C3 on C4 or C4 on C5 levels, immediately above a stiff lower cervical spine. There are two clinical patterns: that with neurological involvement causing cervicobrachial pain or myelopathy and that with neck pain alone. The diagnosis can be made by flexion/extension radiography. All of our eight patients had localised fusion, three anterior and five posterior, and all had satisfactory results one to seven years after operation

A retrospective study is reported of 36 children and adolescents who had undergone spinal exploration and fusion for Type I of Type II spondylolisthesis of more than 10 per cent. The patients were examined and their radiographs studied. No progression of slip after operation was found even in the presence of a pseudarthrosis. Where altered mobility was present at the level above the fusion, this tended to be associated with pain. Posterolateral fusion relieved symptoms in 75 per cent, produced a sound fusion in 83 per cent and prevented further slip in all patients

We investigated the relationship between spinopelvic parameters and disc degeneration in young adult patients with spondylolytic spondylolisthesis. A total of 229 men with a mean age of 21 years (18 to 26) with spondylolytic spondylolisthesis were identified. All radiological measurements, including pelvic incidence, sacral slope, pelvic tilt, lumbar lordosis, sacral inclination, lumbosacral angle (LSA), and sacrofemoral distance, were calculated from standing lateral lumbosacral radiographs. The degree of intervertebral disc degeneration was classified using a modified Pfirrmann scale. We analysed the spinopelvic parameters according to disc level, degree of slip and disc degeneration. There were significant positive correlations between the degree of slip and pelvic incidence (p = 0.009), sacral slope (p = 0.003) and lumbar lordosis (p = 0.010). The degree of slip and the LSA were correlated with disc degeneration (p < 0.001 and p = 0.003, respectively). There was also a significant difference between the degree of slip (p < 0.001) and LSA (p = 0.006) according to the segmental level of disc degeneration. Cite this article: Bone Joint J 2013;95-B:1239–43

A method of stabilising spondylolisthesis using Dwyer instrumentation is described and the results in seven patients are presented. The operation is straightforward, has few complications and also succeeds in reducing the angle of slip

We studied the aetiology of vertebral slip in a long-term follow-up of 22 adult patients with isthmic spondylolysis or spondylolisthesis of L5. Of the 18 with spondylolysis without slip, 13 showed no slip after ten years, but five developed displacement of over 5%. All four patients with spondylolisthesis showed progression of the slip. We found that the vertical thickness of the transverse process of L5 was significantly greater (p < 0.01) in the 13 patients with no slip than in the other two groups. The relationship of vertebral slip to the shape of the transverse processes of L5 may be explained by differences in the bulk or physiological strength of the posterior bands of the iliolumbar ligament

A patient with Rubinstein-Taybi syndrome complicated by tetraplegia secondary to cervical spondylolisthesis is reported. The abnormalities presenting in this condition are reviewed

A modification of a previously reported one-stage technique for reduction and stabilisation of severe spondylolisthesis using a posterior route is described. Reduction is obtained by inserting Harrington rods to lift L5 vertically out of the pelvis and two double-threaded screws to pull it backwards. After reduction the rods are taken away and stabilisation achieved by means of screws and a sacral bar. With this modified technique lumbar vertebrae above L5 are never immobilised, compared with the previous method where the retention of the Harrington rods resulted in more lumbar vertebrae being immobilised than was necessary for fusion. Bone is resected from the sacrum and the fifth lumbar vertebra to avoid too much tension on the nerve roots. Bone grafts are not needed and lumbosacral fusion is achieved within six months due to close contact between the raw bone of the vertebral bodies. Three patients have been treated with this modified technique; there was no reslip, neither during the period when the metallic fixation was in situ nor after its removal

Aims. We reviewed 34 consecutive patients (18 female-16 male) with isthmic spondylolysis and grade I to II lumbosacral spondylolisthesis who underwent in situ posterolateral arthodesis between the L5 transverse processes and the sacral ala with the use of iliac crest autograft. Ten patients had an associated scoliosis which required surgical correction at a later stage only in two patients with idiopathic curves unrelated to the spondylolisthesis. . Methods. No patient underwent spinal decompression or instrumentation placement. Mean surgical time was 1.5 hours (1 to 1.8) and intra-operative blood loss 200 ml (150 to 340). There was one wound infection treated with antibiotics but no other complication. Radiological assessment included standing posteroanterior and lateral, Ferguson and lateral flexion/extension views, as well as CT scans. . Results. A solid posterolateral fusion was confirmed in all patients at mean latest follow-up of 4.7 years (3.4 to 9.8) beyond skeletal maturity into early adult life. Fusion of the isthmic lesion was documented in nine patients bilaterally and eight patients unilaterally. The poor fusion rate across the spondylolysis has not affected the excellent functional results of the procedure, which in our series depended on achieving a stable lumbosacral junction. . Conclusion. Quality of life assessment demonstrated significant improvement in all functional scores and high patient satisfaction with 28 patients returning to previous sports activities at an elite competitive level. Take home message: Posterolateral arthrodesis in situ with autologous iliac crest bone without instrumentation has achieved a solid fusion between the L5 transverse processes and the sacral ala in patients with grade I to II isthmic lumbosacral spondylolisthesis and this has produced excellent clinical outcomes and high patient satisfaction. Cite this article: Bone Joint J 2016;98-B:88–96

We reviewed 20 adult patients with spondylolysis and isthmic spondylolisthesis an average of 10.5 years after treatment by anterior spinal fusion. Nineteen patients had excellent or satisfactory results. Ten of the patients were symptom-free at one year, and 15 were asymptomatic at final follow-up. Anterior spinal fusion can produce results comparable to those of posterior fusion with or without decompression. The results tend to improve with time in contrast to the known worsening of late results after posterior decompression without fusion

From 1948 to 1980, 93 children and adolescents had fusion in situ for severe spondylolisthesis with a slip of 50% or more, at a mean age of 14.8 years. Of these, 52 girls and 35 boys were reviewed after a mean follow-up of 13.8 years. The mean pre-operative slip was 76% and pain frequency correlated with the severity of the lumbosacral kyphosis but not with that of the slip. Posterior fusion was used in 54, posterolateral in 30 and anterior fusion in three patients. There were no major complications but 16 had re-operations for non-union or root symptoms. At follow-up there were three non-unions. After operation, 19 patients had 10% or more progression of the slip, but 10 showed correction by more than 10% as a result of remodelling. The lumbosacral kyphosis had increased by more than 10 degrees in 45%. Postoperative progression of the slip and of lumbosacral kyphosis was significantly more if the posterior element had been removed. At follow-up 77 patients were subjectively improved, four were unchanged, and one was worse. These results did not correlate with either the degree of the slip, or the angle of lumbosacral kyphosis. Fusion in situ is safe and gives good long-term clinical results. Secondary changes are associated with increased lumbosacral kyphosis, so reduction of this should be considered in severe cases

Aims. We compared decompression alone to decompression with fusion surgery for lumbar spinal stenosis, with or without degenerative spondylolisthesis (DS). The aim was to evaluate if five-year outcomes differed between the groups. The two-year results from the same trial revealed no differences. Methods. The Swedish Spinal Stenosis Study was a multicentre randomized controlled trial with recruitment from September 2006 to February 2012. A total of 247 patients with one- or two-level central lumbar spinal stenosis, stratified by the presence of DS, were randomized to decompression alone or decompression with fusion. The five-year Oswestry Disability Index (ODI) was the primary outcome. Secondary outcomes were the EuroQol five-dimension questionnaire (EQ-5D), visual analogue scales for back and leg pain, and patient-reported satisfaction, decreased pain, and increased walking distance. The reoperation rate was recorded. Results. Five-year follow-up was completed by 213 (95%) of the eligible patients (mean age 67 years; 155 female (67%)). After five years, ODI was similar irrespective of treatment, with a mean of 25 (SD 18) for decompression alone and 28 (SD 22) for decompression with fusion (p = 0.226). Mean EQ-5D was higher for decompression alone than for fusion (0.69 (SD 0.28) vs 0.59 (SD 0.34); p = 0.027). In the no-DS subset, fewer patients reported decreased leg pain after fusion (58%) than with decompression alone (80%) (relative risk (RR) 0.71 (95% confidence interval (CI) 0.53 to 0.97). The frequency of subsequent spinal surgery was 24% for decompression with fusion and 22% for decompression alone (RR 1.1 (95% CI 0.69 to 1.8)). Conclusion. Adding fusion to decompression in spinal stenosis surgery, with or without spondylolisthesis, does not improve the five-year ODI, which is consistent with our two-year report. Three secondary outcomes that did not differ at two years favoured decompression alone at five years. Our results support decompression alone as the preferred method for operating on spinal stenosis. Cite this article: Bone Joint J 2024;106-B(7):705–712

Aims. To study the associations of lumbar developmental spinal stenosis (DSS) with low back pain (LBP), radicular leg pain, and disability. Methods. This was a cross-sectional study of 2,206 subjects along with L1-S1 axial and sagittal MRI. Clinical and radiological information regarding their demographics, workload, smoking habits, anteroposterior (AP) vertebral canal diameter, spondylolisthesis, and MRI changes were evaluated. Mann-Whitney U tests and chi-squared tests were conducted to search for differences between subjects with and without DSS. Associations of LBP and radicular pain reported within one month (30 days) and one year (365 days) of the MRI, with clinical and radiological information, were also investigated by utilizing univariate and multivariate logistic regressions. Results. Subjects with DSS had higher prevalence of radicular leg pain, more pain-related disability, and lower quality of life (all p < 0.05). Subjects with DSS had 1.5 (95% confidence interval (CI) 1.0 to 2.1; p = 0.027) and 1.8 (95% CI 1.3 to 2.6; p = 0.001) times higher odds of having radicular leg pain in the past month and the past year, respectively. However, DSS was not associated with LBP. Although, subjects with a spondylolisthesis had 1.7 (95% CI 1.1 to 2.5; p = 0.011) and 2.0 (95% CI 1.2 to 3.2; p = 0.008) times greater odds to experience LBP in the past month and the past year, respectively. Conclusion. This large-scale study identified DSS as a risk factor of acute and chronic radicular leg pain. DSS was seen in 6.9% of the study cohort and these patients had narrower spinal canals. Subjects with DSS had earlier onset of symptoms, more severe radicular leg pain, which lasted for longer and were more likely to have worse disability and poorer quality of life. In these patients there is an increased likelihood of nerve root compression due to a pre-existing narrowed canal, which is important when planning surgery as patients are likely to require multi-level decompression surgery. Cite this article: Bone Joint J 2021;103-B(1):131–140

Aims. The aetiologies of common degenerative spine, hip, and knee pathologies are still not completely understood. Mechanical theories have suggested that those diseases are related to sagittal pelvic morphology and spinopelvic-femoral dynamics. The link between the most widely used parameter for sagittal pelvic morphology, pelvic incidence (PI), and the onset of degenerative lumbar, hip, and knee pathologies has not been studied in a large-scale setting. Methods. A total of 421 patients from the Cohort Hip and Cohort Knee (CHECK) database, a population-based observational cohort, with hip and knee complaints < 6 months, aged between 45 and 65 years old, and with lateral lumbar, hip, and knee radiographs available, were included. Sagittal spinopelvic parameters and pathologies (spondylolisthesis and degenerative disc disease (DDD)) were measured at eight-year follow-up and characteristics of hip and knee osteoarthritis (OA) at baseline and eight-year follow-up. Epidemiology of the degenerative disorders and clinical outcome scores (hip and knee pain and Western Ontario and McMaster Universities Osteoarthritis Index) were compared between low PI (< 50°), normal PI (50° to 60°), and high PI (> 60°) using generalized estimating equations. Results. Demographic details were not different between the different PI groups. L4 to L5 and L5 to S1 spondylolisthesis were more frequently present in subjects with high PI compared to low PI (L4 to L5, OR 3.717; p = 0.024 vs L5 to S1 OR 7.751; p = 0.001). L5 to S1 DDD occurred more in patients with low PI compared to high PI (OR 1.889; p = 0.010), whereas there were no differences in L4 to L5 DDD among individuals with a different PI. The incidence of hip OA was higher in participants with low PI compared to normal (OR 1.262; p = 0.414) or high PI (OR 1.337; p = 0.274), but not statistically different. The incidence of knee OA was higher in individuals with a high PI compared to low PI (OR 1.620; p = 0.034). Conclusion. High PI is a risk factor for development of spondylolisthesis and knee OA. Low pelvic incidence is related to DDD, and may be linked to OA of the hip. Level of Evidence: 1b. Cite this article: Bone Joint J 2020;102-B(9):1261–1267

Aims. Lumbar disc prolapse is a frequent indication for surgery. The few available long-term follow-up studies focus mainly on repeated surgery for recurrent disease. The aim of this study was to analyze all reasons for additional surgery for patients operated on for a primary lumbar disc prolapse. Methods. We retrieved data from the Swedish spine register about 3,291 patients who underwent primary surgery for a lumbar disc prolapse between January 2007 and December 2008. These patients were followed until December 2020 to record all additional lumbar spine operations and the reason for them. Results. In total, 681 of the 3,291 patients (21%) needed one or more additional operations. More than three additional operations was uncommon (2%; 15/906). Overall, 906 additional operations were identified during the time period, with a mean time to the first of these of 3.7 years (SD 3.6). The most common reason for an additional operation was recurrent disc prolapse (47%; 426/906), followed by spinal stenosis or degenerative spondylolisthesis (19%; 176/906), and segmental pain (16%; 145/906). The most common surgical procedures were revision discectomy (43%; 385/906) and instrumented fusion (22%; 200/906). Degenerative spinal conditions other than disc prolapse became a more common reason for additional surgery with increasing length of follow-up. Most patients achieved the minimally important change (MIC) for the patient-reported outcomes after the index surgery. After the third additional spinal operation, only 20% (5/25) achieved the MIC in terms of leg pain, and 29% (7/24) in terms of the EuroQol five-dimension index questionnaire visual analogue scale. Conclusion. More than one in five patients operated on for a lumbar disc prolapse underwent further surgery during the 13-year follow-up period. Recurrent disc prolapse was the most common reason for additional surgery, followed by spinal stenosis and segmental pain. This study shows that additional operations after primary disc surgery are needed more frequently than previously reported, and that the outcome profoundly deteriorates after the second additional operation. The findings from this study can be used in the shared decision-making process. Cite this article: Bone Joint J 2022;104-B(5):627–632

Aims. Although lumbosacral transitional vertebrae (LSTV) are well-documented, few large-scale studies have investigated thoracolumbar transitional vertebrae (TLTV) and spinal numerical variants. This study sought to establish the prevalence of numerical variants and to evaluate their relationship with clinical problems. Methods. A total of 1,179 patients who had undergone thoracic, abdominal, and pelvic CT scanning were divided into groups according to the number of thoracic and lumbar vertebrae, and the presence or absence of TLTV or LSTV. The prevalence of spinal anomalies was noted. The relationship of spinal anomalies to clinical symptoms (low back pain, Japanese Orthopaedic Association score, Roland-Morris Disability Questionnaire) and degenerative spondylolisthesis (DS) was also investigated. Results. Normal vertebral morphology (12 thoracic and five lumbar vertebrae without TLTV and LSTV) was present in 531 male (76.7%) and 369 female patients (75.8%). Thoracolumbar transitional vertebrae were present in 15.8% of males and 16.0% of females. LSTV were present in 7.1% of males and 9.0% of females. The prevalence of the anomaly of 16 presacral mobile vertebrae (total number of thoracolumbar vertebrae and TLTV) without LSTV was 1.0% in males and 4.1% in females, and that of the anomaly of 18 vertebrae without LSTV was 5.3% in males and 1.2% in females. The prevalence of DS was significantly higher in females with a total of 16 vertebrae than in those with normal morphology. There was no significant correlation between a spinal anomaly and clinical symptoms. Conclusion. Overall, 24% of subjects had anomalies in the thoracolumbar region: the type of anomaly differed between males and females, which could have significant implications for spinal surgery. A decreased number of vertebrae was associated with DS: numerical variants may potentially be a clinical problem. Cite this article: Bone Joint J 2021;103-B(7):1301–1308

Whether to combine spinal decompression with fusion in patients with symptomatic lumbar spinal stenosis remains controversial. We performed a cohort study to determine the effect of the addition of fusion in terms of patient satisfaction after decompressive spinal surgery in patients with and without a degenerative spondylolisthesis. The National Swedish Register for Spine Surgery (Swespine) was used for the study. Data were obtained for all patients in the register who underwent surgery for stenosis on one or two adjacent lumbar levels. A total of 5390 patients fulfilled the inclusion criteria and completed a two-year follow-up. Using multivariable models the results of 4259 patients who underwent decompression alone were compared with those of 1131 who underwent decompression and fusion. The consequence of having an associated spondylolisthesis in the operated segments pre-operatively was also considered. At two years there was no significant difference in patient satisfaction between the two treatment groups for any of the outcome measures, regardless of the presence of a pre-operative spondylolisthesis. Moreover, the proportion of patients who required subsequent further lumbar surgery was also similar in the two groups. In this large cohort the addition of fusion to decompression was not associated with an improved outcome. Cite this article: Bone Joint J 2013;95-B:960–5

Aims. The aim of this study is to test the hypothesis that three grades of sagittal compensation for standing posture (normal, compensated, and decompensated) correlate with health-related quality of life measurements (HRQOL). Methods. A total of 50 healthy volunteers (normal), 100 patients with single-level lumbar degenerative spondylolisthesis (LDS), and 70 patients with adult to elderly spinal deformity (deformity) were enrolled. Following collection of demographic data and HRQOL measured by the Scoliosis Research Society-22r (SRS-22r), radiological measurement by the biplanar slot-scanning full body stereoradiography (EOS) system was performed simultaneously with force-plate measurements to obtain whole body sagittal alignment parameters. These parameters included the offset between the centre of the acoustic meatus and the gravity line (CAM-GL), saggital vertical axis (SVA), T1 pelvic angle (TPA), McGregor slope, C2-7 lordosis, thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), PI-LL, sacral slope (SS), pelvic tilt (PT), and knee flexion. Whole spine MRI examination was also performed. Cluster analysis of the SRS-22r scores in the pooled data was performed to classify the subjects into three groups according to the HRQOL, and alignment parameters were then compared among the three cluster groups. Results. On the basis of cluster analysis of the SRS-22r subscores, the pooled subjects were divided into three HRQOL groups as follows: almost normal (mean 4.24 (SD 0.32)), mildly disabled (mean 3.32 (SD 0.24)), and severely disabled (mean 2.31 (SD 0.35)). Except for CAM-GL, all the alignment parameters differed significantly among the cluster groups. The threshold values of key alignment parameters for severe disability were TPA > 30°, C2-7 lordosis > 13°, PI-LL > 30°, PT > 28°, and knee flexion > 8°. Lumbar spinal stenosis was found to be associated with the symptom severity. Conclusion. This study provides evidence that the three grades of sagittal compensation in whole body alignment correlate with HRQOL scores. The compensation grades depend on the clinical diagnosis, whole body sagittal alignment, and lumbar spinal stenosis. The threshold values of key alignment parameters may be an indication for treatment. Cite this article: Bone Joint J 2020;102-B(10):1359–1367

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 claudication; 2) lumbar degenerative spondylolisthesis with leg pain; 3) lumbar disc herniation with leg weakness; 4) lumbar scoliosis with back pain; and 5) thoracolumbar disc herniation with myelopathy. This survey was sent to 110 members of The Hip Society and 101 members of the Scoliosis Research Society. The choices of the surgeons were compared among scenarios and between surgical specialties using the chi-squared test. The free-text comments were analyzed using text-mining. Results. Responses were received from 51 hip surgeons (46%) and 37 spine surgeons (37%). The percentages of hip surgeons recommending ‘hip first’ differed significantly among scenarios: 59% for scenario 1; 73% for scenario 2; 47% for scenario 3; 47% for scenario 4; and 10% for scenario 5 (p < 0.001). The percentages of spine surgeons recommending ‘hip first’ were 49% for scenario 1; 70% for scenario 2; 19% for scenario 3; 78% for scenario 4; and 0% for scenario 5. There were significant differences between the groups for scenarios 3 (more hip surgeons recommended ‘hip first’; p = 0.012) and 4 (more hip surgeons recommended ‘spine first’; p = 0.006). Conclusion. In patients with coexistent OA of the hip and degenerative disorders of the spine, the question of ‘hip or spinal surgery first’ elicits relatively consistent answers in some clinical scenarios, but remains controversial in others, even for experienced surgeons. The nature of neurological symptoms can influence surgeons’ decision-making. Cite this article: Bone Joint J 2019;101-B(6 Supple B):37–44

We examined the reliability of radiological findings in predicting segmental instability in 112 patients (56 men, 56 women) with a mean age of 66.5 years (27 to 84) who had degenerative disease of the lumbar spine. They underwent intra-operative biomechanical evaluation using a new measurement system. Biomechanical instability was defined as a segment with a neutral zone > 2 mm/N. Risk factor analysis to predict instability was performed on radiographs (range of segmental movement, disc height), MRI (Thompson grade, Modic type), and on the axial CT appearance of the facet (type, opening, vacuum and the presence of osteophytes, subchondral erosion, cysts and sclerosis) using multivariate logistic regression analysis with a forward stepwise procedure. The facet type was classified as sagittally orientated, coronally orientated, anisotropic or wrapped. Stepwise multivariate regression analysis revealed that facet opening was the strongest predictor for instability (odds ratio 5.022, p = 0.009) followed by spondylolisthesis, MRI grade and subchondral sclerosis. Forward stepwise multivariate logistic regression indicated that spondylolisthesis, MRI grade, facet opening and subchondral sclerosis of the facet were risk factors. Symptoms evaluated by the Short-Form 36 and visual analogue scale showed that patients with an unstable segment were in significantly more pain than those without. Furthermore, the surgical procedures determined using the intra-operative measurement system were effective, suggesting that segmental instability influences the symptoms of lumbar degenerative disease

Aims. 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. Patients and Methods. 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 (. sd. 11.3). We excluded those with adult deformity and spondylolisthesis. Presenting symptoms, levels operated on initially and at re-operation were studied. MRI measurements included the anteroposterior diameter of the bony spinal canal, the degree of disc degeneration, and the thickness of the ligamentum flavum. DSS was defined by comparative measurements of the bony spinal canal. Risk factors for re-operation at the adjacent level were determined and included in a multivariate stepwise logistic regression for prediction modelling. Odds ratios (ORs) with 95% confidence intervals were calculated. Results. Of the 235 patients, 21.7% required re-operation at an adjacent segment. Re-operation at an adjacent segment was associated with DSS (p = 0.026), the number of levels decompressed (p = 0.008), and age at surgery (p = 0.013). Multivariate regression model (p < 0.001) controlled for other confounders showed that DSS was a significant predictor of re-operation at an adjacent segment, with an adjusted OR of 3.93. Conclusion. Patients with DSS who have undergone lumbar spinal decompression are 3.9 times more likely to undergo future surgery at an adjacent level. This is a poor prognostic indicator that can be identified prior to index decompression surgery

We describe the results of a prospective case series of patients with spondylolysis, evaluating a technique of direct stabilisation of the pars interarticularis with a construct that consists of a pair of pedicle screws connected by a U-shaped modular link passing beneath the spinous process. Tightening the link to the screws compresses bone graft in the defect in the pars, providing rigid intrasegmental fixation. We have carried out this procedure on 20 patients aged between nine and 21 years with a defect of the pars at L5, confirmed on CT. The mean age of the patients was 13.9 years (9 to 21). They had a grade I or less spondylolisthesis and no evidence of intervertebral degeneration on MRI. The mean follow-up was four years (2.3 to 7.3). The patients were assessed by the Oswestry Disability Index (ODI) and a visual analogue scale (VAS). At the latest follow-up, 18 patients had an excellent clinical outcome, with a significant (p < 0.001) improvement in their ODI and VAS scores. The mean ODI score at final follow-up was 8%. Assessment of the defect by CT showed a rate of union of 80%. There were no complications involving the internal fixation. The strength of the construct removes the need for post-operative immobilisation

Degenerative spondylolisthesis is most common at the L4/L5 level and in women. There are several possible reasons for its predilection at this site, but there is no satisfactory explanation for the predominance in women. We considered that pregnancy was a possible influence. We reviewed the records and radiographs of 949 women and 120 men aged 50 years and over who had attended a spinal surgeon for low back pain over a five-year period. We found that women who had borne children had a significantly higher incidence of degenerative spondylolisthesis than nulliparous women (28% v 16.7%; p = 0.043). The men had a 7.5% incidence, significantly less than nulliparous women (p = 0.031). Our results suggest that pregnancy is an important factor in the aetiology of degenerative spondylolisthesis

Aims

The aim of this study was to assess the accuracy of pedicle screw placement, as well as intraoperative factors, radiation exposure, and complication rates in adult patients with degenerative disorders of the thoracic and lumbar spines who have undergone robotic-navigated spinal surgery using a contemporary system.

The purpose of this study was to determine whether it would be feasible to use oblique lumbar interbody fixation for patients with degenerative lumbar disease who required a fusion but did not have a spondylolisthesis. A series of CT digital images from 60 patients with abdominal disease were reconstructed in three dimensions (3D) using Mimics v10.01: a digital cylinder was superimposed on the reconstructed image to simulate the position of an interbody screw. The optimal entry point of the screw and measurements of its trajectory were recorded. Next, 26 cadaveric specimens were subjected to oblique lumbar interbody fixation on the basis of the measurements derived from the imaging studies. These were then compared with measurements derived directly from the cadaveric vertebrae. Our study suggested that it is easy to insert the screws for L1/2, L2/3 and L3/4 fixation: there was no significant difference in measurements between those of the 3-D digital images and the cadaveric specimens. For L4/5 fixation, part of L5 inferior articular process had to be removed to achieve the optimal trajectory of the screw. For L5/S1 fixation, the screw heads were blocked by iliac bone: consequently, the interior oblique angle of the cadaveric specimens was less than that seen in the 3D digital images. . We suggest that CT scans should be carried out pre-operatively if this procedure is to be adopted in clinical practice. This will assist in determining the feasibility of the procedure and will provide accurate information to assist introduction of the screws. Cite this article: Bone Joint J 2013;95-B:977–82

We assigned 67 patients with central lumbar stenosis alternately to either multiple laminotomy or total laminectomy. The protocol, however, allowed multiple laminotomy to be changed to total laminectomy if it was thought that the former procedure might not give adequate neural decompression. There were therefore three treatment groups: group I consisting of 26 patients submitted to multiple laminotomy; group II, 9 patients scheduled for laminotomy but submitted to laminectomy; and group III, 32 patients scheduled for, and submitted to, laminectomy. The mean follow-up was 3.7 years. Bilateral laminotomy at two or three levels required a longer mean operating time than total laminectomy at an equal number of levels. The mean blood loss at surgery and the clinical results did not differ in the three groups. The mean subjective improvement score for low back pain was higher in group I but there was also a higher incidence of neural complications in this group. No patient in group I had postoperative vertebral instability, whereas this occurred in three patients in groups II and III, who had lumbar scoliosis or degenerative spondylolisthesis preoperatively. Multiple laminotomy is recommended for all patients with developmental stenosis and for those with mild to moderate degenerative stenosis or degenerative spondylolisthesis. Total laminectomy is to be preferred for patients with severe degenerative stenosis or marked degenerative spondylolisthesis

We reviewed 40 patients treated surgically for lumbar stenosis at an average time of 8.6 years after operation. In 32, total laminectomy had been performed and in eight bilateral laminotomy, both at one or more levels. Of the 16 patients with degenerative spondylolisthesis, ten had had a concomitant spinal fusion. Patients were assigned to one of four groups according to the amount of bone regrowth: group 0 had no regrowth and groups I, II, and III, had mild, moderate or marked regrowth, respectively. Only 12% of the patients showed no bone regrowth; 48% were assigned to group I, 28% to group II and 12% to group III. Imaging studies showed varying degrees of recurrent stenosis in patients with moderate or marked bone regrowth. All patients with degenerative spondylolisthesis showed bone regrowth, which was more severe in those who had not had a fusion. The clinical results were satisfactory in most of the patients with mild or no bone regrowth and significantly less good in those with moderate or marked regrowth. In the group with degenerative spondylolisthesis, the proportion of satisfactory results was significantly higher in patients who had had spinal fusion. The long-term results of surgery for lumbar stenosis depend both upon the amount of bone regrowth and the degree of postoperative vertebral stability

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

1. During a fifteen-year period a clinical, radiological and in some cases a surgical study has been made of 319 patients suffering from spondylolisthesis–that is, forward slipping of one lumbar vertebra on another or forward sagging of the whole lumbar spine in relation to the sacrum. 2. The five etiological factors are described, and the cases are assigned to five groups according to the factor responsible for the slip. In every case slipping is permitted by a lesion of the apparatus which normally resists the forward thrust of the lower lumbar spine–that is, the hook of the neural arch composed of the pedicle, the pars interarticularis and the inferior articular facet engaging caudally over the superior articular facet of the vertebra below. 3. In Group I (congenital spondylolisthesis–sixty-six cases) the lesion is a congenital defect of the facets. In Group II (spondylolytic spondylolisthesis–164 cases) the lesion occurs in the region of the pars interarticularis and is either an elongation of the bone or a break in continuity. There are reasons for thinking that the lesion is caused by stress over a long period rather than by acute injury or by a congenital anomaly of ossification. In Group IV (degenerative spondylolisthesis–eighty cases) the lesion of the facets is degenerative. There are no good grounds for thinking that an abnormality of the angle between the facets and the pedicles is the primary lesion behind the degenerative change. 4. Group III and V comprise few cases. In the former (traumatic spondylolisthesis–three cases) the lesion–a fracture of the neural arch–is caused by a single severe injury. In Group V (pathological spondylolisthesis–six cases) the slipping is caused by weakness of bone from various causes. 5. A full description is given of the etiological and biomechanical features of each group. A special investigation has been made into the etiological factors in degenerative spondylolisthesis. 6. The incidence of involvement of nerve tissues is highest in degenerative spondylolisthesis; the most severe degrees of slip are found in congenital spondylolisthesis

Understanding spinopelvic mechanics is important for the success of total hip arthroplasty (THA). Despite significant advancements in appreciating spinopelvic balance, numerous challenges remain. It is crucial to recognize the individual variability and postoperative changes in spinopelvic parameters and their consequential impact on prosthetic component positioning to mitigate the risk of dislocation and enhance postoperative outcomes. This review describes the integration of advanced diagnostic approaches, enhanced technology, implant considerations, and surgical planning, all tailored to the unique anatomy and biomechanics of each patient. It underscores the importance of accurately predicting postoperative spinopelvic mechanics, selecting suitable imaging techniques, establishing a consistent nomenclature for spinopelvic stiffness, and considering implant-specific strategies. Furthermore, it highlights the potential of artificial intelligence to personalize care.

Cite this article: Bone Joint J 2024;106-B(11):1206–1215.

1. A detailed analysis of the anatomy of spondylolisthesis reveals many causes of serious interference with the nerve roots. 2. These anatomical findings can be correlated with the symptoms. 3. In association with spondylolisthesis, cases of disc prolapse, tuberculosis, and a cauda equina lesion are described. 4. Adequate decompression of the affected nerve root is essential in all cases with sciatica. The operative procedure is described. 5. The problem of arthrodesis will be discussed fully in a separate paper

We studied 21 former top-class competitive javelin throwers to investigate radiological and clinical symptoms in the lumbar spine many years after the end of their athletic careers. The athletes underwent clinical and radiological examinations at an average of 20 years after retiring from athletics. The Hannover questionnaire was used to evaluate functional restrictions in daily living. Degenerative changes in the lumbar spine were more marked towards the caudal aspect of the spine. Ten athletes also had spondylolisthesis, but with little progression (< 15%) throughout the observation period. Athletes both with and without radiologically demonstrated spondylolisthesis, complained of no more back problems than the normal population (93% for athletes v 86% for controls). Slight progression followed their retirement from athletics

Aims

Some patients presenting with hip pain and instability and underlying acetabular dysplasia (AD) do not experience resolution of symptoms after surgical management. Hip-spine syndrome is a possible underlying cause. We hypothesized that there is a higher frequency of radiological spine anomalies in patients with AD. We also assessed the relationship between radiological severity of AD and frequency of spine anomalies.

In recent years, machine learning (ML) and artificial neural networks (ANNs), a particular subset of ML, have been adopted by various areas of healthcare. A number of diagnostic and prognostic algorithms have been designed and implemented across a range of orthopaedic sub-specialties to date, with many positive results. However, the methodology of many of these studies is flawed, and few compare the use of ML with the current approach in clinical practice. Spinal surgery has advanced rapidly over the past three decades, particularly in the areas of implant technology, advanced surgical techniques, biologics, and enhanced recovery protocols. It is therefore regarded an innovative field. Inevitably, spinal surgeons will wish to incorporate ML into their practice should models prove effective in diagnostic or prognostic terms. The purpose of this article is to review published studies that describe the application of neural networks to spinal surgery and which actively compare ANN models to contemporary clinical standards allowing evaluation of their efficacy, accuracy, and relatability. It also explores some of the limitations of the technology, which act to constrain the widespread adoption of neural networks for diagnostic and prognostic use in spinal care. Finally, it describes the necessary considerations should institutions wish to incorporate ANNs into their practices. In doing so, the aim of this review is to provide a practical approach for spinal surgeons to understand the relevant aspects of neural networks.

Cite this article: Bone Joint J 2021;103-B(9):1442–1448.

Aims

Use of the direct anterior approach (DAA) for total hip arthroplasty (THA) has increased in recent years due to proposed benefits, including a lower risk of dislocation and improved early functional recovery. This study investigates the dislocation rate in a non-selective, consecutive cohort undergoing THA via the DAA without any exclusion or bias in patient selection based on habitus, deformity, age, sex, or fixation method.

Aims

To report the surgical outcome of patients with severe Scheuermann’s kyphosis treated using a consistent technique and perioperative management.

We describe a patient with a traumatic spondylolisthesis of L5 and multiple, bilateral pedicle fractures from L2 to L5. Conservative treatment was chosen, with eventual neurological recovery and bony union. We are not aware of previous reports of this pattern of injury

We report the occurrence of spondylolysis and/or spondylolisthesis of the lumbar vertebrae in five patients with osteopetrosis, four of them having multiple lesions. The case histories indicate that spondylolysis had developed in the pathological bone as a result of increased stress and that it is an acquired lesion

A method of repairing the defect in spondylolisthesis by internal fixation with screws and bone grafting is described. Sixteen patients have been operated upon with only one failure. In two cases the spine was re-explored for incidental complications and the defect was found to have fused solidly

1. Four out of five patients with spondylolisthesis, four-fifths of whom were seen at least five years after operation, had their symptoms relieved after posterior spinal fusion. 2. In a small series of patients treated by anterior spinal fusion, the results were less successful

A system is presented for the analysis of failure after spinal operations: 1) outright failure; 2) temporary relief; 3) failure in spondylolisthesis; and 4) infections. With this system it is possible to trace the causes of failure and to correct some of them. When they are used as a guide before operation, the recommendations made should help to prevent many failures

A method of posterior lumbo-sacral fusion is described in which springs are used to fix the grafts and to maintain immobilisation. Fifty patients with lumbar disc degeneration or spondylolisthesis have been reviewed. The results have been assessed clinically by grading the symptoms before and after operation. Stay in hospital has been short and return to work rapid. There has been a high proportion of good results

1. An enterogenous cyst lying in the cauda equina opposite the third lumbar vertebra, and associated with spina bifida occulta of the fifth lumbar vertebra and spondylolisthesis of the fifth lumbar on the first sacral vertebra, is described in a man aged thirty-five suffering from chronic low back pain and sciatica. 2. Current embryological theories concerning the formation of intraspinal enterogenous cysts from primitive gut cells are further substantiated by the features of this case

The development of the iliolumbar ligament and its anatomy and histology were studied in cadavers from the newborn to the ninth decade. The structure was entirely muscular in the newborn and became ligamentous only from the second decade, being formed by metaplasia from fibres of the quadratus lumborum muscle. By the third decade, the definitive ligament was well formed; degenerative changes were noted in older specimens. The iliolumbar ligament may have an important role in maintaining lumbosacral stability in patients with lumbar disc degeneration, degenerative spondylolisthesis and pelvic obliquity secondary to neuromuscular scoliosis

1. Forty-six cases of congenital spondylolisthesis (Newman's Group 1) have been studied. The diagnostic criteria were lumbo-sacral subluxation, deficient development of sacral neural arches and superior facets, and attenuation and elongation of the pars interarticularis, with or without a defect in continuity. 2. Intertransverse lumbo-sacral fusion is a safe and reliable method of treatment. 3. Stabilisation is not complete before two years. 4. Spinal fusion is indicated in all patients with significant symptoms during the period of growth, but in adult patients only if conservative treatment fails

1. A new operation of body-to-body intervertebral fusion by grafts introduced through a posterior approach is described. This is a preliminary report of early results, with follow-up to two years, which seems to be encouraging. 2. In spondylolisthesis, abnormal mobility of the loose posterior neural arch is believed in itself to cause nerve root pressure, and excision of the arch is an important part of the operation. 3. In the few cases where spinal fusion is needed after removal of a prolapsed intervertebral disc—and the proportion is now very low—posterior intervertebral fusion has proved very satisfactory

We studied 23 patients with spondylolysis of the fifth lumbar vertebra (L5) and 20 with spondylolytic spondylolisthesis at this level. All were more than 40 years of age. The transverse processes at L5 were significantly wider in the former group than in the latter. We also dissected 56 cadavers to study the morphological relationship between the transverse process of L5 and the iliolumbar ligament, and found that the wider transverse process is associated with increased width of the posterior band of the iliolumbar ligament. If a patient with pars defects has wide transverse processes at L5, the lumbosacral junction may be stabilised by wide posterior bands of the iliolumbar ligament and the fifth lumbar vertebra by the ligament, preventing anterior displacement

A study of spondylolysis and spondylolisthesis in 142 children and adolescents is reported. In twelve of the seventy-nine patients followed for over a year the affected vertebra slipped further by 10 per cent or more. Increasing slip occurred mainly during the adolescent growth spurt, and was greater when spinal bifida or other vertebral anomalies were present. If at presentation the slip is less than 30 per cent then further slip beyond 30 per cent is unlikely. Decompression posteriorly is advised when signs of nerve pressure are present. Indications for spinal fusion are suggested; the intertransverse method of fusion was used in sixty-nine patients

Lumbar spondylolysis can heal with conservative treatment, but few attempts have been made to identify factors which may affect union of the defects in the pars. We have evaluated, retrospectively, the effects of prognostic variables on bony union of pars defects in 134 young patients less than 18 years of age with 239 defects of the pars who had been treated conservatively. All patients were evaluated by CT scans when first seen and more than six months later at follow-up. The results showed that the spinal level and the stage of the defects were the predominant factors. The site of the defects in the pars, the presence or development of spondylolisthesis, the condition of the contralateral pars, the degree of lumbar lordosis and the degree of lumbar inclination all significantly affected union

Transitional vertebrae (TV) may be one of the risk factors for lumbar disc herniation. It is not clear, however, whether the presence of TV can affect the development of nerve-root symptoms. Our aim was to clarify this relationship. A total of 501 patients with lumbar degenerative disease and nerve-root symptoms was studied in respect of their level and the presence of TV. As a control group, 508 patients without low back pain or nerve-root symptoms were studied to establish the incidence of TV. In patients with disc herniation, the incidence was statistically higher and the mean age lower in patients with TV than in those without. In most patients, the symptomatic disc level was just above the TV. Similarly, in those with stenosis of the spinal canal without spondylolisthesis, the symptomatic disc level was most commonly just above the TV

We reviewed the radiographs of 325 unselected patients with defects in the pars interarticularis of L5 to study whether the incidence of vertebral slip in spondylolysis of L5 remained unchanged after the age of 20 years. MRI was also carried out on 111 of the patients to investigate the relationship between the shape of the transverse process of L5 and the degeneration of the discs adjacent to this level. The incidence of spondylolisthesis increased with age from 17% in the second decade to 51% in the sixth. The transverse process was significantly more slender in patients with less degeneration at L4/5 and advanced degeneration at L5/S1 than in patients with advanced degeneration at L4/5 and less degeneration at L5/S1. Vertebral slip secondary to an isthmic defect of L5 after the age of 20 years was confirmed and the adjacent disc degeneration was significantly related to the vertical thickness of the transverse process of L5

We have reviewed 31 consecutive patients, aged 65 years or more, after surgical decompression for degenerative lumbar spinal stenosis. The average follow-up was 42 months. Assessment included a standard questionnaire, a pain diagram which was completed by the patient, and clinical and radiological examination. Patients were considered in three groups; degenerative spondylolisthesis (19), lateral recess stenosis (5), and central-mixed stenosis (7). The indication for surgery was leg pain: no patient had an operation for back pain alone. Fusion was never performed. Overall, 64% of the patients had an excellent result, 17% a good result and 19% a poor result. We conclude that the long-term outcome of decompressive surgery in the elderly is good; it does not differ from that reported for younger patients

Between 1979 and 1989, we treated 22 patients with symptomatic lumbar spondylolysis which had not responded to conservative treatment by a modified Scott wiring technique to give direct repair of the lytic defects with stabilisation. The patients' mean age at the time of operation was 15 years; the mean follow-up period was four years. All 19 patients under 25 years old had satisfactory results. Two of the three patients over 25 years old had poor results. The age of the patient at surgery seems to be an important determinant of outcome. Radiologically confirmed fusion is of secondary importance. The presence of a grade I spondylolisthesis did not prejudice the result. We recommend the Scott wiring technique to stabilise the direct repair of a lumbar spondylolysis

1. At the present stage of our experience, when 150 patients have been analysed over a period of five years, the conclusion has been reached that anterior interbody fusion in the lower lumbar spine is a procedure which should be added to our surgical armamentarium for use in selected cases. 2. Patients suffering from chronic intervertebral disc degeneration whose main symptoms are recurrent incapacitating backache derive the most benefit from this procedure. 3. When used as a salvage operation in patients who have had previous unsuccessful laminectomy or posterior fusion, good results can be expected. 4. In patients with spondylolisthesis anterior interbody fusion should be confined to cases in which the vertebral bodies have not slipped forward more than one-third

1. Anterior transperitoneal lumbar fusion is a successful method of stabilising painful mechanical derangements which have not responded to the usual conservative measures. 2. The operation in this series was done mainly for backache; it should not be contemplated if there is definite evidence of nerve root compression, because sequestrated disc material cannot be removed from the spinal canal from the anterior route. 3. Careful technique has resulted in few complications attributable to the operation. 4. This method is sometimes thought to be inapplicable in cases of spondylolisthesis with a displacement of more than one-third. However, in this series we have seen the block type of graft used with a good measure of clinical and radiological success. 5. There is no doubt that for those patients who have had previous unsuccessful laminectomies or posterior fusions anterior interbody fusion offers an excellent prospect of recovery

1. The clinical experience of fourteen cases of traumatic spondylolisthesis of the axis is described. 2. Evidence is presented which suggests that vertical compression and extension forces are frequently involved. 3. Treatment is based on recognition of the deforming force and its extent. 4. Primary treatment of unstable lesions by the coronally placed bone dowel of Barbour allows early stabilisation and long-term security. 5. The increased antero-posterior diameter of the axis explains the low incidence of spinal cord damage. 6. Skull traction is considered illogical in that it runs parallel in effect to the most deadly form of judicial hanging. 7. Secondary stability following injury may allow continuing force to fracture the spine at other levels. 8. The paradox of an extension injury between the second and third cervical vertebrae and a "flexion" injury at a lower level is discussed

There is ambiguity concerning the nomenclature and classification of fractures of the ring of the second cervical vertebra (C2). Disruption of the pars interarticularis which defines true traumatic spondylolisthesis of C2, is often wrongly called a pedicle fracture. Our aim in this study was to assess the influence of asymmetry on the anatomical and functional outcome and to evaluate the criteria of instability established by Roy-Camille et al. We studied the plain radiographs and CT scans of 24 patients: 13 were judged to be asymmetrical, ten were considered unstable and 14 stable. Treatment was with a Minerva jacket in 15 fractures and by operation in nine. Surgery was undertaken in patients with severe C2 to C3 sprains. One patient with an unstable lesion refused operation and was treated conservatively with a poor radiological result. Our study showed that asymmetry of the fracture did not affect the outcomes of treatment and should not therefore influence decisions in treatment. The criteria of Roy-Camille seem to be reliable and useful. We prefer the posterior approach to the cervical spine, which allows both stabilisation of the fracture and correction of a local kyphosis

This review shows that inter-body spinal fusion can be achieved in a satisfying percentage of cases, and the assertion that there is an intrinsic factor peculiar to the vertebral bodies which prevents such a fusion cannot be supported. The operation has a limited but definite place in the field of spinal surgery, and should be reserved for those patients with spinal instability associated with intractable and persistent backache. Spondylolisthesis is the indication par excellence. A new operative technique, which has been developed during ten years, has become standardised. The trans-sacral approach provides a better and safer exposure than those described before. In the event of failure of inter-body fusion, it is suggested that further attempts at grafting should be restricted to one of the posterior methods which have a 75 per cent chance of producing successful bony fusion. Clinical photographs are reproduced in Figures 16 to 18 to show that patients suffering from a painful spondylolisthesis may be restored to normal activity by this operation

We analysed the complications encountered in 102 consecutive patients who had posterolateral lumbosacral fusion performed with transpedicular screw and rod fixation for non-traumatic disorders after a minimum of two years. Of these, 40 had spondylolysis and spondylolisthesis, 42 a degenerative disorder, 14 instability after previous laminectomy and decompression, and six pain after nonunion of previous attempts at spinal fusion without internal fixation. There were 75 multilevel and 27 single-level fusions. There were 76 individual complications in 48 patients, and none in the other 54. The complications seen were screw misplacement, coupling failure of the device, wound infection, nonunion, permanent neural injury, and loosening, bending and breakage of screws. Screw breakage or loosening was more common in patients with multilevel fusions (p < 0.001). Screws of 5 mm diameter should not be used for sacral fixation. Forty-six patients had at least one further operation for one or several complications, including 20 fusion procedures for nonunion. The high incidence of complications is a disadvantage of this technically-demanding method

Two different classifications of discograms have been used in a prospective study of 279 injected discs in 100 patients. The five-stage classification of Adams, Dolan and Hutton (1986) showed increased degeneration in the lower lumbar discs and more degenerative changes in men than in women. Exact reproduction of the patient's pain on injection was more common in fissured or ruptured discs than in less degenerate discs, with 81% sensitivity and 64% specificity of the discogram for pain. The additional information obtained by comparing computerised tomography (CT) with discograms was minimal. Discography was found to be useful in the evaluation of chronic low back pain in patients whose ordinary CT scans, myelograms and flexion-extension radiographs were normal. In spondylolysis and spondylolisthesis, discography can disclose whether fusion needs to be extended above the lytic level, and it may show if the pain in patients who have had posterolateral fusion is discogenic. Thus, discography gives information which is useful in deciding whether to operate on patients with chronic low back pain

The fourth lumbar vertebrae and L4-5 discs from six cadaveric lumbar spines were subjected to detailed strain gauge analysis under conditions of controlled loading. With central compression loads, maximal compressive strain was found to occur near the bases of the pedicles and on both superficial and deep surfaces of the pars interarticularis, which emphasises the importance of the posterior elements of lumbar vertebrae in transmitting load. Radial bulge and tangential strain of the disc wall were maximal at the posterolateral surface, in agreement with the fact that disc degeneration and prolapse commonly occur there. Under posterior offset loads simulating extension, both compressive and tensile strains were found to be increased on both surfaces of the pars interarticularis, which suggests that hyperextension may lead to stress fractures and spondylolisthesis. Posterior offset loads also increased the radial bulge of the posterior disc wall and tangential strain at the anterior surface of the disc. Anterior offset loads simulating flexion increased the radial bulge of the anterior disc wall and tangential strain at the posterior surface of the disc. These findings are compatible with movement of the nucleus pulposus within the disc during flexion and extension. This hypothesis was supported by post-mortem discography

Aims

The aim of this study was to explore risk factors for complications associated with dural tear (DT), including the types of DT, and the intra- and postoperative management of DT.

We have developed criteria to determine the appropriate indications for lumbar laminectomy, using the standard procedure developed at the RAND corporation and the University of California at Los Angeles (RAND-UCLA). A panel of five surgeons and four physicians individually assessed 1000 hypothetical cases of sciatica, back pain only, symptoms of spinal stenosis, spondylolisthesis, miscellaneous indications or the need for repeat laminectomy. For the first round each member of the panel used a scale ranging from 1 (extremely inappropriate) to 9 (extremely appropriate). After discussion and condensation of the results into three categories laminectomy was considered appropriate in 11% of the 1000 theoretical scenarios, equivocal in 26% and inappropriate in 63%. There was some variation between the six categories of malalignment, but full agreement in 64% of the hypothetical cases. We applied these criteria retrospectively to the records of 196 patients who had had surgical treatment for herniated discs in one Swiss University hospital. We found that 48% of the operations were for appropriate indications, 29% for equivocal reasons and that 23% were inappropriate. The RAND-UCLA method is a feasible, useful and coherent approach to the study of the indications for laminectomy and related procedures, providing a number of important insights. Our conclusions now require validation by carefully designed prospective clinical trials, such as those which are used for new medical techniques

Aims

The aim of this study was to use diffusion tensor imaging (DTI) to investigate changes in diffusion metrics in patients with cervical spondylotic myelopathy (CSM) up to five years after decompressive surgery. We correlated these changes with clinical outcomes as scored by the Modified Japanese Orthopedic Association (mJOA) method, Neck Disability Index (NDI), and Visual Analogue Scale (VAS).

1. A relatively simple method of spinal fusion with internal splinting by screw fixation has been described. Complications have been few. 2. Emphasis is placed upon thorough removal of soft tissue, correct placement of screws of good length, the exposure of bleeding bone wherever possible in the fusion area, and the use of well packed cancellous bone. 3. There is enough spongy bone in one posterior superior iliac spine for an ordinary spinal fusion, and, if more is needed, the other is readily available through the same skin incision. Not only is cancellous bone more desirable than a massive cortical graft, but the leg is spared, allowing early walking and freedom from complications in the limb. 4. The lateral articulations are left intact. 5. Screw fixation has eliminated the use of external support except in spondylolisthesis, or when so much bone has been removed during laminectomy that good fixation cannot be obtained. 6. Early, sometimes immediate, relief of symptoms is usual after operation, and early walking with moderate activity is desirable. 7. When the operation was done for degenerative changes with no apparent defect in the laminae there was no radiological evidence of failure of fusion after operations at one level, but two failures were found after attempted fusions at multiple levels. 8. Root irritation from screw contact in two patients was due to faulty technique. A method of screw placement to avoid this complication is described and illustrated by radiographs and photographs of a cadaver specimen. 9. There has been no known instance of an adverse psychological effect from the use of screws. Rather, there has commonly been a lively and healthy interest shown in the factor which has allowed early activity

Aims

Chronic low back pain due to degenerative disc disease is sometimes treated with fusion. We compared the outcome of three different fusion techniques in the Swedish Spine Register: noninstrumented posterolateral fusion (PLF), instrumented posterolateral fusion (IPLF), and interbody fusion (IBF).

Aims

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).

Aims

While previously underappreciated, factors related to the spine contribute substantially to the risk of dislocation following total hip arthroplasty (THA). These factors must be taken into consideration during preoperative planning for revision THA due to recurrent instability. We developed a protocol to assess the functional position of the spine, the significance of these findings, and how to address different pathologies at the time of revision THA.

There remains confusion in the literature with regard to the spinopelvic relationship, and its contribution to ideal acetabular component position. Critical assessment of the literature has been limited by use of conflicting terminology and definitions of new concepts that further confuse the topic. In 2017, the concept of a Hip-Spine Workgroup was created with the first meeting held at the American Academy of Orthopedic Surgeons Annual Meeting in 2018. The goal of this workgroup was to first help standardize terminology across the literature so that as a topic, multiple groups could produce literature that is immediately understandable and applicable. This consensus review from the Hip-Spine Workgroup aims to simplify the spinopelvic relationship, offer hip surgeons a concise summary of available literature, and select common terminology approved by both hip surgeons and spine surgeons for future research.

Cite this article: Bone Joint J 2019;101-B:808–816.

Aims

Clinical and radiological data were reviewed for all patients with mucopolysaccharidoses (MPS) with thoracolumbar kyphosis managed non-operatively or operatively in our institution.

We evaluated the impact of lumbar instrumented circumferential fusion on the development of adjacent level vertebral compression fractures (VCFs). Instrumented posterior lumbar interbody fusion (PLIF) has become a popular procedure for degenerative lumbar spine disease. The immediate rigidity produced by PLIF may cause more stress and lead to greater risk of adjacent VCFs. However, few studies have investigated the relationship between PLIF and the development of subsequent adjacent level VCFs.

Between January 2005 and December 2009, a total of 1936 patients were enrolled. Of these 224 patients had a new VCF and the incidence was statistically analysed with other covariants. In total 150 (11.1%) of 1348 patients developed new VCFs with PLIF, with 108 (72%) cases at adjacent segment. Of 588 patients, 74 (12.5%) developed new subsequent VCFs with conventional posterolateral fusion (PLF), with 37 (50%) patients at an adjacent level. Short-segment fusion, female and age older than 65 years also increased the development of new adjacent VCFs in patients undergoing PLIF. In the osteoporotic patient, more rigid fusion and a higher stress gradient after PLIF will cause a higher adjacent VCF rate.

Cite this article: Bone Joint J 2015;97-B:1411–16.

Aims

The aim of this study was to determine if positive Waddell signs were related to patients’ demographics or to perception of their quality of life.

Methods

In this study of patients who underwent internal fixation without fusion for a burst thoracolumbar or lumbar fracture, we compared the serial changes in the injured disc height (DH), and the fractured vertebral body height (VBH) and kyphotic angle between patients in whom the implants were removed and those in whom they were not. Radiological parameters such as injured DH, fractured VBH and kyphotic angle were measured. Functional outcomes were evaluated using the Greenough low back outcome scale and a VAS scale for pain.

Back pain is a common symptom in children and adolescents. Here we review the important causes, of which defects and stress reactions of the pars interarticularis are the most common identifiable problems. More serious pathology, including malignancy and infection, needs to be excluded when there is associated systemic illness. Clinical evaluation and management may be difficult and always requires a thorough history and physical examination. Diagnostic imaging is obtained when symptoms are persistent or severe. Imaging is used to reassure the patient, relatives and carers, and to guide management.

Cite this article: Bone Joint J 2014;96-B:717–23.

Aims

Minimally invasive transforaminal lumbar interbody fusion (MITLIF) has been well validated in overweight and obese patients who are consequently subject to a higher radiation exposure. This prospective multicentre study aimed to investigate the efficacy of a novel lumbar localisation system for MITLIF in overweight patients.

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% vs 87.6%; p < 0.02), although there were no significant differences in the improvement of the Oswestry Disability Index between the two groups. Most dural tears were small, managed by taking adequate care of symptoms of low cerebrospinal fluid pressure, and did not require direct dural repair. Routine MRI scans were undertaken six months post-operatively; four patients with a dural tear had recurrent or residual disc herniation and two had further stenosis, possibly because the dural tear prevented adequate decompression and removal of the fragments of disc during surgery; as yet, none of these patients have undergone further surgery.

Cite this article: Bone Joint J 2014;96-B:641–5.

Aims

We present the results of correcting a double or triple curve adolescent idiopathic scoliosis using a convex segmental pedicle screw technique.

We investigated the spinopelvic morphology and global sagittal balance of patients with a degenerative retrolisthesis or anterolisthesis. A total of 269 consecutive patients with a degenerative spondylolisthesis were included in this study. There were 95 men and 174 women with a mean age of 64.3 years (sd 10.5; 40 to 88). A total of 106 patients had a pure retrolisthesis (R group), 130 had a pure anterolisthesis (A group), and 33 had both (R+A group).

A backward slip was found in the upper lumbar levels (mostly L2 or L3) with an almost equal gender distribution in both the R and R+A groups. The pelvic incidence and sacral slope of the R group were significantly lower than those of the A (both p < 0.001) and R+A groups (both p < 0.001). The lumbar lordosis of the R+A group was significantly greater than that of the R (p = 0.025) and A groups (p = 0.014). The C7 plumb line of the R group was located more posteriorly than that of the A group (p = 0.023), but was no different from than that of the R+A group (p = 0.422). The location of C7 plumb line did not differ between the three groups (p = 0.068). The spinosacral angle of the R group was significantly smaller than that of the A group (p < 0.001) and R+A group (p < 0.001).

Our findings imply that there are two types of degenerative retrolisthesis: one occurs primarily as a result of degeneration in patients with low pelvic incidence, and the other occurs secondarily as a compensatory mechanism in patients with an anterolisthesis and high pelvic incidence.

Cite this article: Bone Joint J 2013;95-B:1244–9.