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Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_20 | Pages 5 - 5
1 Nov 2016
Teeter M Lam K Howard J Lanting B Yuan X
Full Access

Radiostereometric analysis (RSA) has become the gold standard technique for measuring implant migration and wear following joint replacement due to its high measurement precision and accuracy. However, RSA is conventionally performed using two oblique radiographic views with the presence of a calibration cage. Thus, a second set of radiographs must be acquired for clinical interpretation, for example anterior-posterior and cross-table lateral views following total hip arthroplasty (THA). We propose a modification to the RSA setup for examining THA, in which RSA measurements are performed from anterior-posterior and lateral views, with the calibration cage images acquired separately from the patient images. The objective of the current study was to compare the accuracy and precision of the novel technique to the conventional technique using a phantom.

X-ray cassette holders were developed to enable simultaneous acquisition of anterior-posterior and cross-table lateral radiographs with the patient in a supine position in the RSA suite. A Sawbones phantom with total hip implant components was attached to a micrometer-driven stage. The femoral component was translated known distances relative to the acetabular cup in all planes, mimicking head penetration due to wear. Double RSA examinations were acquired for each increment using the traditional and novel radiograph orientations. Translations were measured from the radiographic images using RSA software. For both techniques, accuracy was calculated by comparing the measured translations to the known translation from the micrometer, and reported as the 95% confidence interval. Precision was measured by comparing the measured translations between the double exams, and reported as the standard deviation.

Accuracy was greater for the conventional technique in the inferior-superior axis (p = 0.03), greater for the novel technique in the anterior-posterior axis (p = 0.01), and equivalent in the medial-lateral axis (p = 0.06). Overall accuracy for both the conventional and novel techniques was identical at ±0.022 mm. Precision was equivalent between both techniques for the medial-lateral (p = 0.68), inferior-superior (p = 0.14), and anterior-posterior axes (p = 0.86). Overall precision for the conventional technique was ±0.127 mm and for the novel technique was ±0.095 mm.

Utilising standard clinical radiograph view angles within an RSA exam had no detrimental effect on wear measurement accuracy or precision. This reduces the barriers to implementing RSA imaging in routine follow-up of arthroplasty patients, potentially greatly increasing the numbers of patients that can have quantitative data on implant performance. Future applications can involve applying more clinically relevant radiograph view angles to RSA exams of the knee and shoulder.


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_6 | Pages 27 - 27
1 Apr 2014
Eseonu K Hunt R Athanassacopoulos M Leong J Lam K Lucas J Ember T Tucker S Nadarajah R
Full Access

Aims:

Identifying and scoring risk factors that predict early wound dehiscence and progression to metalwork infection. Results of wound healing, eradication of infection and union of with the use of vacuum dressing. Compare results of serial washouts against early vacuum dressing in this group of children with significant medical co-morbidities.

Method:

A retrospective review of 300 patients with neuromuscular scoliosis who underwent posterior instrumented correction and fusion between 2008 and 2012 at two institutions. 10 patients had an early wound dehiscence which progressed to deep seated infection requiring wound washout(s) and subsequent vacuum dressing. Medical notes, clinical photographs and imaging were reviewed. Minimum follow up period was 14 months.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_III | Pages 100 - 100
1 Feb 2012
Kiely P Lam K Breakwell L Sivakumaran R Kerslake R Webb J Scheuler A
Full Access

Background

High velocity vertical aircraft ejection seat systems are credited with aircrew survival of 80-95% in modern times. Use of these systems is associated with exposure of the aircrew to vertical acceleration forces in the order of 15-25G. The rate of application of these forces may be up to 250G per sceond. Up to 85% of crew ejecting suffer skeletal injury and vertebral fracture is relatively common (20-30%) when diagnosed by plain radiograph. The incidence of subtle spinal injury may not be as apparent.

Aim

A prospective study to evaluate spinal injury following high velocity aircraft ejection.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 566 - 566
1 Oct 2010
Lam K Anbar A Lucas J O’Dowd J
Full Access

Introduction: Pedicle screws are now commonly used to instrument the thoracic spine and offers improved three point fixation and therefore theoretically offers better derotation of the spine during corrective manoeuvres in scoliosis surgery.

Aim: To compare thoracic scoliosis correction using either pedicle hooks or pedicle screws.

Methods: Two patient groups were studied. Data was collected prospectively and this is a review of the radiological data. All patients had structural thoracic scoliosis. Group 1, 14 patients (9 female and 5 male) mean age 14.6, were treated with posterior correction of scoliosis using the standard USS II technique using pedicle hooks and screws. Group 2, 14 patients (11 female and 3 male) mean age 15.3 were treated using pedicle screws alone to correct the apical deformity, using a variation of the original USS technique. Pre and postoperative Cobb angle, apical vertebral rotation (AVR, Perdriolle method) and apical vertebral translation (AVT) were measured. Unpaired “t” test was used to compare the magnitude of correction in both groups. The mean follow up period was 30 months (range: 27–42).

Results: The mean corrections of Cobb angle, AVR and AVT, in group I were 61.1% (range: 48.5–83.9), 33.3% (range: 8.6–100) and 62.9% (range: 43.2–91.4), respectively. In Group 2 the corrections were: 57.4% (range: 21.4–81.7), 57.2% (range:16.7–100) and 58.7% (range: 34–80.9). There were no statistically significant differences between the correction of Cobb angle or AVT in both groups (P=0.479 and 0.443 respectively). However, the pedicle screws proved to be more effective at correcting the AVR (P= 0.017). No complications occurred and correction has been well maintained with a minimum of 2 year follow-up.

Conclusion: Pedicle screws can safely and effectively replace the pedicle hooks in the classical USS technique. They are more effective at correcting the rotational deformity, although do not provide a better correction of Cobb angle. These technical results now need to be correlated with relevant clinical outcomes.


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

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

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

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

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

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

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


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 566 - 566
1 Oct 2010
Lam K Anbar A O’Brien A
Full Access

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

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

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

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


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 565 - 565
1 Oct 2010
Lam K O’Brien A Webb J
Full Access

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

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

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

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

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


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 205 - 205
1 Mar 2010
Gao GX Mahadev A Lam K Lee E
Full Access

This study is to evaluate the effectiveness and outcome of our protocol: Russell traction followed by gentle manipulative reduction with a single screw fixation & spica cast immobilization.

Twenty-three patients with thirty hips of slipped capital femoral epiphysis were treated in our department, KK Women’s and Children’s Hospital, Singapore between 1997 and 2005. Except one patient lost of follow-up, twenty-four SCFEs with more than 2 years follow-up were reviewed. In this series, there were 13 boys & 5 girls, mean age 12 year old ranging from 10 to 14 years. Among them 7 were Chinese, 6 Malays & 5 Indians. There were 12 unilateral cases (8 on the left & 4 right, 67%) & 6 bilateral cases (33%), including 2 patients found contralateral SCFE subsequently 1 year postoperatively. Acute-on-chronic SCFE were 16 & chronic SCFE 8. 16 were Grate I & 8 Grate II. Russell traction was on preoperatively with an average of 6 days. Gentle manipulative reduction under general anesthesia was performed in 20 SCFEs (12 GI & 8 GII) and 17 of them were successful. Fixation with a single screw was used for all cases except one hip with 2 screws.

Average follow-up was 38.5 months. Good results achieved. All patient were symptom free with good function. No complications of AVN, chondrolysis, screw loosening and reslipping of the affective hips.

Our protocol of management for SCFE has been largely successful in term of manipulative reduction and fixation.

This is a safe, simple and effective management.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_II | Pages 209 - 210
1 May 2009
Kiely P Lam K Kendrew J Scheuler A Breakwell L Kerslake R Webb J
Full Access

High velocity vertical aircraft ejection seat systems are credited with aircrew survival of 80–95% in modern times. Use of these systems is associated with exposure of the aircrew to vertical acceleeration forces in the order of 15–25G. The rate of application of these forces maybe upto 250G per sceond. Upto 85% of crew ejecting suffer skeletal injury and vertebral fracture is relatively common (20–30%) when diagnosed by plain radiograph. The incidence of subtle spinal injury may not be as apparent.

A prospective case series, admitted to QMC Nottingham, from 1996 to 2006 was evaluated. During this interval 26 ejectees from 20 aircraft were admitted to the spinal studies unit for comprehensive examination, evaluation and management. The investigations included radiographs of the whole spine and magnetic resonance Imaging (incorporating T1, T2 weighted and STIR saggital sequences). All ejections occurred within the ejection envelope and occurred at an altitude under 2000 feet (mean 460 feet) and at an airspeed less than 500 knots (mean 275 knots).

In this series 6 ejectees (24%) had clinical and radiographic evidence of vetebral compression fractures. These injuries were located in the thoracic and thoracolumbar spine. 4 cases required surgery ( indicated for angular kyphosis greater than 30 degrees, significant spinal canal compromise, greater than 50% or neurological injury. 1 patient had significant neurological compromise, following an AO A3.3 injury involving the L2 vertebra.

11 ejectees (45 %) had MRI evidence of a combined total of 22 occult thoracic and lumbar fractures. The majority of these ejectees with occult injury had multilevel injuries.

This study confirms a high incidence if spinal fracture and particularly occult spinal injury. Evidently vertical emergency aircraft ejection imposes major insults on the spinal column. Once, appropriately prioritised, life preservation measures have been undertaken, an early MRI of the spne is mandatory as part of comprehensive patient evaluation.

Correspondence should be addressed to Major M Butler RAMC, Princess Elizabeth Orthopaedic Centre, Royal Devon and Exeter Hospital, Exeter, Devon.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_I | Pages 75 - 75
1 Mar 2009
Al-Nammari S Bejjanki N Lucas J Lam K
Full Access

Introduction: MRSA spondylodiscitis is an increasingly common phenomenon. Despite this there is very little reported on it.

Objectives: Our objective was to present relevant demographics, clinical presentations and outcomes for this condition from our institution.

Methods: We performed a retrospective review of patients presenting over a six year period from 2000 to 2005.

Results: 13 cases were identified. The mean age was 65 years (range 36–92), 85% were male. All cases presented with back pain, spinal tenderness and systemic upset. Neurological deficit was present initially in 38% and a further 8% developed neurological deterioration during treatment. The thoracic spine (53%) was most commonly affected followed by the lumbar (33%), thoracolumbar junction (7%) and cervical spine (7%); 16% of cases were multilevel. The WCC, ESR and CRP were elevated in all cases with means of 17.3 ×10-9/L, 102 mm/hr and 236 mg/L respectively. In cases cured of infection, the WCC, ESR and CRP normalised at a mean of 10 weeks, 14 weeks and 19 weeks respectively. Radiological diagnosis was established with MRI in all cases. The most common risk factors were diabetes mellitus (62%), mal-nourishment (54%), cirrhosis (31%), end stage renal failure (15%) and intravenous drug use (15%). Multiple risk factors were present in 76% of cases and 15% had no identifiable risk factors. The main sources of sepsis were intravenous catheters (23%), urinary tract (15%) and intravenous drug use (15%). In cases cured of infection treatment consisted of intravenous vancomycin mono-therapy for a mean period of four weeks followed by oral combination or monotherapy antimicrobials for a mean period of 8 weeks. Operative intervention was required in 38% of cases. At six months 54% of cases were clinically free of infection, 38% had died and 8% required ongoing treatment. Neurological deficit was present in 50% of survivors. At one year 29% of survivors suffered from MRSA bacteraemia and spondylodiscitis recurrence.

Conclusion: This is a devastating condition. Clinical suspicion should remain high and prompt diagnosis and treatment is essential.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_III | Pages 451 - 451
1 Aug 2008
Courtier NJ O’Dowd JK Will EA Lucas JD Lam K Wraige E
Full Access

Aim: The aim of this study is to prospectively evaluate the functional outcome of surgical correction in 20 patients with a significant neuromuscular scoliosis.

Method and Results: The principal objective of surgical correction of neuromuscular spinal deformity should be to maintain or improve function of the patient, but there is little evidence to support this. In wheelchair dependent patients the goal is also to maintain sitting ability, and in ambulant patients prevention of further deformity is important. Studies formally quantifying these outcome parameters have not been published with modern surgical techniques.

A consecutive series of 20 children with neuromuscu-lar scoliosis (age range 2–18 years) undergoing surgical correction were evaluated using 2 standard functional assessment tools, the Seated Postural Control Measure (SPCM) which assesses posture and function, and the Pediatric Evaluation of Disability Inventory (PEDI) which records functional ability in the domains of self-care, mobility and social function. The patients were evaluated pre-operatively and then at 2 weeks, 3 and 12 months post-operatively.

Complete data is presented for all patients at 3 months and 13 of 20 patients at 1 year follow up, the remaining data is to be collected.

The SPCM demonstrated an improvement in posture in 95% from pre-op to 2 weeks post-op, with 25% demonstrating some regression at 3 months. Most maintained or improved this at 1 year. The PEDI demonstrated a reduction in mobility at 3 months but at 1 year 60% returned to preop status.

Conclusion: Sitting position is improved by surgery, but mobility is impaired for a significant period following the correction, which may have more impact on the child’s and families life. Families need to be counselled prior to surgery about the loss of mobility and ability to self-care post operatively but that it does return by one year.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_III | Pages 449 - 449
1 Aug 2008
Anbar A Simcik J Lam K Lucas J O’Dowd J
Full Access

Aim: To compare thoracic scoliosis correction using either pedicle hooks or pedicle screws.

Methods and results: Two patient groups were studied. Data was collected prospectively and this is a review of the radiological data. All patients had structural thoracic scoliosis. Group 1, 14 patients (9 female and 5 male) mean age 14.6, were treated with posterior correction of scoliosis using the standard USS II technique using pedicle hooks and screws. Group 2, 14 patients (11 female and 3 male) mean age 15.3 were treated using pedicle screws alone to correct the apical deformity, using a variation of the original USS technique. Pre and postoperative Cobb angle, apical vertebral rotation (AVR, Perdriolle method) and apical vertebral translation (AVT) were measured.

Unpaired “t” test was used to compare the magnitude of correction in both groups. The mean follow up period was 6.7 months (range:3–18).

The mean corrections of Cobb angle, AVR and AVT, in group I were 61.1% (range:48.5–83.9), 33.3% (range:8.6–100) and 62.9% (range:43.2–91.4), respectively. In Group 2 the corrections were: 57.4% (range:21.4–81.7), 57.2% (range:16.7–100) and 58.7% (range:34–80.9).

There is no statistically significant difference between the correction of Cobb angle or AVT in both groups (P=0.479 and 0.443 respectively). However, the pedicle screws proved to be more effective at correcting the AVR (P= 0.017). No complications occurred and correction has been well maintained.

Conclusion: Pedicle screws can safely and effectively replace the pedicle hooks in the classical USS technique. They are more effective at correcting the rotational deformity, although do not provide a better correction of Cobb angle. These technical results now need to be correlated with relevant clinical outcomes.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_III | Pages 233 - 234
1 Sep 2005
Clarke A Lam K Freeman B
Full Access

Study Design: Prospective cohort study

Summary of Background data: A definite link between Modic end plate changes and discogenic low back pain has yet to be established. However, current prospective data indicates that Modic changes strongly correlate with the pain provocation of lumbar discography and improved clinical outcome following instrumented posterolateral fusion. Consequently, there is recent heightened awareness using this radiological entity in the selection of patients for interbody fusion or total disc replacement.

Objective: To prospectively evaluate whether Modic changes can predict improved clinical outcome following antero-posterior lumbar interbody fusion using femoral ring allograft.

Methods: A cohort of chronic low back pain patients were investigated with MRI and lumbar discography. Twenty-six patients with disco-graphically-proven concordant pain reproduction were prospectively entered into the study. Clinical results were collected using the Oswestry Disability Index (ODI), Visual Analogue Scale (VAS) and Short Form 36 Health Questionnaire (SF-36) at the pre-operative and two-year follow up. The minimal clinically important difference (MCID) was taken as 10 points for ODI, 2 points for VPAS, and 7 points for the physical function and bodily pain subset of the SF-36 questionnaire.

Results: MRI scans evaluated for the level fused revealed 13 patients with no end-plate changes (Type 0), whilst 2 patients had Modic Type I and 11 had Modic Type II changes. MCID in ODI were achieved in Type 0, Type 1 and Type 2, but improvement in VAS only was achieved in the Type 0 and Type 1. For SF-36, the MCID of 7 points was reached in most domains for all types of Modic change. There was no statistical difference in clinical outcome between those patients with Modic Type 0 and those with Modic type I or II.

Conclusion: This prospective study shows that Modic changes do not predict improved clinical outcome following antero-posterior interbody fusion using the femoral ring allograft.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_III | Pages 240 - 240
1 Sep 2005
Lam K Kerslake R Webb J
Full Access

Study Design: Retrospective review.

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

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

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

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

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


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_III | Pages 233 - 233
1 Sep 2005
Jones A Clarke A Freeman B Lam K Grevitt M
Full Access

Study Design. A reliability study of the Modic classification.

Objective. To determine the reliability and reproducibility of the Modic classification for lumbar vertebral marrow changes.

Summary of Background data. In 1988, Modic with colleagues described two degenerative stages of vertebral marrow and endplate morphology. These were Type I (inflammatory phase) and Type II (fatty phase). Later in 1988, he added a third variety; Type III where there was marked sclerosis adjacent to the endplates. No formal reliability or reproducibility studies had been performed on the Modic classification.

Methods. This study involved five independent observers of differing spinal experience using the Modic classification to grade fifty sagittal T1 and T2 weighted MRI scans. The observers repeated the assessment at three weeks. Intra- and inter-observer reliabilities were assessed using kappa statistics.

Results. There were 7 type I, 40 type II, 1 type III and 2 normal levels. The individual intra-observer agreement was substantial or excellent with kappa values ranging from 0.71 to 1.00. The overall inter-observer agreement was excellent with a kappa value of 0.85. There was complete agreement in 78% of the levels, a difference of one type in 14% and a difference of two or more in 8% of levels. The level of experience of the observer did not correlate with a better score.

Conclusions. We have shown that the Modic classification is both reliable and reproducible. It is simple and easy to apply for observers of varying clinical experience. We therefore recommend its use in clinical research and practice.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_III | Pages 240 - 240
1 Sep 2005
Helm A Sell P Lam K
Full Access

Study Design: A retrospective case note review.

Objective: To report on the accuracy of the Harlow-Wood bone biopsy trephine used via a percutaneous approach to obtain tissue from vertebral lesions.

Methods: 82 patients undergoing this procedure in either the University Hospital Nottingham or Leicester Royal Infirmary between 1995 and 2003 were included in the study. Data was collected regarding the provisional diagnosis, MRI diagnosis and final diagnosis based on micro-biological and histological reports.

Outcome Measures: Microbiological and histological reports were reviewed to determine the pathological nature of each biopsy. If the biopsy returned a positive diagnosis, or if the biopsy confirmed normal vertebral microbiology and histology in a patient who was subsequently disease-free, then the biopsy was deemed to have provided a diagnosis.

Results: The technique provided a diagnosis in 88% of cases, with a sensitivity of 87% and specificity of 100%. Where the provisional diagnosis was of a neoplastic lesion (n = 48), the diagnosis rate was 88%. Where the provisional diagnosis was of an infective lesion (n = 26), the diagnosis rate was 89%. Where the provisional diagnosis was uncertain (n = 8), the diagnosis rate was 88%.

Conclusions: Percutaneous biopsy of vertebral lesions using the Harlow-Wood bone trephine under fluoroscopic guidance can be performed safely and efficaciously. The high accuracy and sensitivity of this closed percutaneous technique, particularly in infective lesions, allows a timely diagnosis and subsequent early commencement of appropriate treatment.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_III | Pages 236 - 237
1 Sep 2005
Tokala D Lam K Freeman B Webb J
Full Access

Study Design: Retrospective study.

Objective: To describe a modified cervico-thoracic extension osteotomy and evaluate clinical & radiographic outcomes.

Subjects: 10 patients with fixed cervico-thoracic kyphosis, average age 56 years, minimum 12 months follow-up. Three patients had psoriatic spondyloarthropathy, Three patients had previous lumbar osteotomies.

Technique: General anaesthesia and SSEP spinal cord monitoring was used. Complete laminectomy of C7, hemilaminectomy of C6 and T1, plus pedicle subtraction osteotomy and decancellisation of C7 was performed. Upon completion of the osteotomy, controlled halo manipulation allowed closure of the osteotomy: the pivot point being the anterior longitudinal ligament. Segmental fixation with lateral mass and pedicle screws plus bone graft was then added. All patients were immobilised for three months in halo-jacket.

Results: Restoration of normal forward gaze was achieved in all patients. Mean preoperative kyphosis of 17 degrees was corrected to lordosis of 36 degrees (mean total correction 53 degrees). No spinal cord injuries or permanent nerve root palsies occurred. Three patients had mild sensory radiculopathies lasting a few weeks. No loss of correction, no pseudarthrosis, one patient had 50% anterior subluxation that later united. Two deep infections were successfully treated with wound washout and antibiotics.

Conclusions: Cervico-thoracic osteotomy in ankylosing spondylitis continues to be challenging and hazardous. C7 decancellisation and extension osteotomy supplemented with segmental internal fixation provides immediate spinal stability, reduces sagittal spinal translation and associated high risk of neurological injury, whilst maintaining correction until bony union.


Orthopaedic Proceedings
Vol. 86-B, Issue SUPP_II | Pages 116 - 116
1 Feb 2004
Mehdian H Lam K Freeman B
Full Access

Objective: To emphasize the need to provide a controlled method of intra-operative reduction to correct fixed cervical flexion deformities in ankylosing spondylitis and to describe the technique involved.

Design: The treatment of severe fixed cervical flexion deformity in ankylosing spondylitis represents a challenging problem that is traditionally managed by a corrective cervicothoracic osteotomy. The authors describe a method of controlled surgical reduction of the deformity, which eliminates saggital translation and reduces the risk of neurological injury.

Subjects: 2 male patients aged 39 and 45 years old with ankylosing spondylitis presented with severe fixed flexion deformity of the cervical spine. Both patients had previously undergone a lumbar extension osteotomy to correct a severe thoracolumbar kyphotic deformity. As a result of the fixed cervical flexion deformity, marked restriction in forward gaze with ‘chin on chest’ deformity, feeding difficulties and personal hygiene were encountered in both. Their respective chin-brow to vertical angle was 60 and 72°. Somatosensory and motor evoked potentials were used throughout surgery. A combination of cervical lateral mass screws and thoracic pedicle screws were used. Interconnecting malleable rods were then fixed at the cervical end, thereby allowing them to slide through the thoracic clamps thus achieving a safe method of controlled closure of the cericothoracic osteotomy. When reduction was achieved, definitive pre-contoured titanium rods were interchanged. Halo-jacket was not considered necessary in view of the segmental fixation used.

Results: Good anatomical reduction was achieved, with near complete correction of the deformities, restoration of saggital balances and forward gazes. There were no neurological deficits in either patient and the postoperative recoveries were uneventful. Both osteotomies united with no deterioration noted at 2 years.

Conclusions: We illustrate a controlled method of surgical reduction during corrective cervicothoracic osteotomy of fixed cervical kyphosis in ankylosing spondylitis. This has been achieved with the use of a combination of cervical lateral mass screws and thoracic pedicle screws with interconnecting malleable rods that were later replaced with titanium rods. The authors believe that the unique technique described remains a technically demanding but adequate and safe approach for correcting such challenging deformities.


Orthopaedic Proceedings
Vol. 86-B, Issue SUPP_II | Pages 119 - 119
1 Feb 2004
Cole A Behensky H Burwell R Lam K Tokala P Pratt R Webb J
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Objective: To assess the radiological and back surface correction achieved following anterior USS in the treatment of thoracic adolescent idiopathic scoliosis (AIS).

Design: Prospective study of back surface correction, retrospective radiological review.

Subjects: 14 patients with thoracic AIS (age 11–18 yrs) were treated with anterior USS between 1995 and 2000. There are 12 females and 2 males, all with 2 year follow-up. 8 patients have complete surface data. Data from a further 6 patients will shortly be available as they reach 2 year follow-up.

Outcome measures: Cobb angle, apical vertebral rotation (AVR), apical vertebral translation (AVT), frontal plane imbalance, kyphosis and lordosis were measured from the radiographs. A Scoliometer was used to assess the maximal angle of trunk inclination (max ATI) in the thoracic region. All measurements were obtained before surgery and at 8 weeks, 1 year and 2 years after surgery. Complications were recorded.

Results: Significant initial corrections are observed for each of: Cobb angle (51%, p< 0.001), AVR (40%, p=0.003),AVT (64%,p< 0.001),maxATI (47%,p=0.001). There is no significant correction loss during the 2 year follow-up. Three patients had spinal imbalance (> 2cm) before surgery with one patient after surgery. The kyphosis significantly increased from 24° to 29° immediately after surgery with no significant change during follow-up. There was no change in lordosis. There were no neurological complications and no instrumentation failures were observed. In two cases the upper screw partially pulled out of T5 with some loss of correction.

Conclusions: Anterior scoliosis correction for thoracic AIS achieves good and stable radiological and particularly back surface corrections (max ATI – 47% compared with 22% correction after posterior surgery). Rigid anterior instrumentation has eliminated the 20% rod failure seen with Zielke. New techniques for preventing upper screw pull out will be discussed and new retractor systems allow smaller thoracotomies. There remains a small but significant increase in kyphosis which is less of a problem in the thoracic spine than at the thoracolumbar junction where anterior scoliosis correction is most commonly advocated.

Anterior instrumentation for thoracic AIS has advanced to a point where it can be widely adopted, particularly if the patient expresses concerns regarding the rib hump or is hypokyphotic.


Orthopaedic Proceedings
Vol. 85-B, Issue SUPP_I | Pages 48 - 48
1 Jan 2003
Lam K Sharan D Moulton A Greatrex G Das S Whiteley A Srivastava V
Full Access

Many surgical approaches at decompression have been attempted for the thoracic outlet syndrome (TOS), but only the transaxillary and supraclavicular routes carry the best outcomes. More recently, a selective and tailored approach via the supraclavicular route has been favoured. We performed a retrospective review between 1978 and 1998, and report the outcome of the ‘’two surgeon approach’’ for TOS via the supraclavicular method.

An orthopaedic and vascular surgeon jointly conducted 30 operations for disabling symptoms relating to TOS in 27 patients (21F, 6M), mean age of 29 yrs (range 18–63 yrs), having performed the preoperative assessment in conjunction with a neurologist. In all cases, it was essential that patient selection for surgery was determined on clinical grounds rather than the presence of a cervical rib. Anterior scalenectomy was performed via the supraclavicular route except in one case where the infraclavicular route was utilised. Additional surgical procedures were carried out according to the underlying abnormalities, i.e. excision of cervical rib or band or medial scalenectomy. The first rib was always spared.

At mean follow-up of 37 mths (range 3-228 mths), 26/30 sides (87%) had excellent or good results. The results were fair or poor in three cases where scalenec-tomy alone was performed. There were no major complications and no patients required a re-operation. 24 patients (89%) returned to their previous lifestyle or occupation.

Our results suggest that, with a multidisciplinary assessment and two-surgeon team, good to excellent surgical outcomes can be achieved via the supraclavicular route without resection of the first rib. Instead of the current practise of routine transaxillary first rib resection, we recommend decompression via this approach with further procedures tailored to the abnormality identified.