Introduction

Anterior tibial translation (ATT) is assessed in the acutely injured knee to investigate for ligamentous injury and rotational laxity. Specifically, there is a growing recognition of the significance of anterior medial rotary laxity (AMRI) as a crucial element in assessing knee stability. Anterior cruciate ligament (ACL) injuries are often accompanied with medial collateral ligament (MCL) damage. It has been suggested that Deep MCL (dMCL) fibres are a primary restraint in rotational displacement. This research aims to quantify the difference in rotational laxity of patients with ACL and MCL injuries to deem if the Feagin-Thomas test can robustly capture metrics of AMRI. 2.

Abstract

Abstract

Abstract

Abstract

Introduction

Patients with recurrent low back pain (LBP) exhibit changes in postural control. Stereotypical muscle activations resulting from external perturbations include anticipatory (APAs) and compensatory (CPAs) postural adjustments. This study aimed to determine differences in postural control strategies (APAs and CPAs) between those with and without lumbar disc degeneration (LDD) and LBP.

Purpose

The behavioural change wheel methodology and social cognitive theory were combined to inform and develop a rehabilitation programme following lumbar fusion surgery (REFS).

This qualitative study evaluated participant's experiences of lumbar fusion surgery, including REFS, to identify valued programme content (‘active ingredients’).

Introduction

Low back pain (LBP) is the top leading global cause of years lived with disability. In order to examine LBP, researchers have typically viewed the spine in isolation. Clinically, it is imperative that the lower limbs are also considered. The aim of this study was to design a holistic and reliable multi-segmental kinematic model of the spine and lower limbs.

Introduction

The usefulness of markers of non-specific low back pain (NSLBP), including MRI derived measurements of cross-sectional area (CSA) and functional CSA (FCSA, fat free muscle area) of the lumbar musculature, is in doubt. To our knowledge, such markers remain unexplored in Lumbar Disc Degeneration (LDD), which is significantly associated with NSLBP, Modic change and symptom recurrence. This exploratory 3.0-T MRI study addresses this shortfall by comparing asymmetry and composition in asymptomatic older adults with and without Modic change.

Background

Persistent low back and leg pain is a common and highly disabling musculoskeletal condition. Many patients seek the opinion of a neurosurgeon with a view to surgical intervention. Few data are available which document the experiences of patients at these consultations.

Purpose and Background:

Clinical interpretations of Degenerative Lumbar Disc Disease are not described in the literature. The purpose of this study was to establish a consensus of expert clinical opinion in order to fuel further research.

Background

The current ‘gold standard’ method for enabling weightbearing during non-invasive lower limb immobilisation is to use a Patella Tendon-Bearing (PTB) or Sarmiento cast. The Beagle Böhler Walker™ is a non-invasive frame that fits onto a standard below knee plaster cast. It is designed to achieve a reduction in force across the foot and ankle.

Our objective was to measure loading forces through the foot to examine how different types of casts affect load distribution. We aimed to determine whether the Beagle Böhler Walker™ is as effective or better, at reducing load distribution during full weightbearing.

Statement of Purpose

It is well known that individuals with a history of low back pain (hLBP) exhibit altered movement patterns that are caused by changes in neuromuscular control. Postural disturbance provides an effective method for creating these differentiable movement patterns. This study has explored the response of the lower limb and spine to a translational perturbation similar to that experienced on public transport in healthy volunteers and those with hLBP.

Introduction

Changes in central nervous system (CNS) pathways controlling trunk and leg muscles in patients with low back pain(LBP) and lumbar radiculopathy have been observed and this study investigated whether surgery impacts upon these changes in the long term.

Gathering reliable information about joint movement during activities of daily living is of clinical interest. Here we present pilot data regarding a new wearable knee joint sensing system by comparing the outcomes of this device to a gold standard. Initial results show a complex, but repetitive pattern. These outcomes generate potential for future work.

Background

The measurement of pelvic kinematics is key to the analysis of aberrant movement patterns of lower back, yet to date technical issues of skin artefacts, body composition and optical motion tracking sensor occlusion [1] are unresolved.

Introduction

This study sought to determine whether the functional outcome of two common spinal operations could be improved by a programme of post-operative rehabilitation and/or an educational booklet each compared with usual care.

Background

Several theories have been put forward with respect to the mechanical role of the thoracolumbar fascia (TLF) but none have been substantiated in part due to an inability to explore its function in vivo. This study explored the use of ultrasound to image the layers of the TLF in vivo.

Background

The clinical assessment of Chronic Low Back Pain (CLBP) is usually undertaken at a single time point at clinic rather than through continuous monitoring. To address this, a wearable prototype sensor to monitor motion of the lumbar spine and pelvis has been developed.

Introduction

Changes in the central nervous system (CNS) pathways controlling trunk and leg muscles in patients with low back pain and radiculopathy have been observed and this study investigated whether surgery impacts upon these changes.

Patients have an important role in evaluating the health-care they receive; including the treatment they receive as well as the healthcare process. This information can be invaluable in understanding patient needs and developing a more patient centred approach to health care. As part of an RCT into the post-operative management of spinal surgery we explored patient’s experience of the health care system and their perceptions of how the system worked for them.

To date 201 patients have completed the trial; 60 receiving usual care, 37 an educational booklet, 48 rehabilitation and 56 received both booklet and rehabilitation after decompression surgery for stenosis or disc prolapse. The majority (82%) were referred to the consultant through their GP. 40% identified a specific event that led to their pain; of these 48% reported a longstanding pain and 33% noting a sudden injury. 30% waited less than a month for surgery, and 32% 1–3 months. 18% experienced surgical cancellations. The majority of patients felt well informed pre-operatively, had faith in their surgical team and had sufficient time to discuss their condition. Similarly during their operative stay they felt supported and in good hands. When questioned about their feelings on the health care process as a whole; positive patient comments included: the speed and quality of surgery and the pain relief experienced; whilst negative comments included: lack of information or advice, the delays between diagnosis and management, dissatisfaction with GP care, feeling abandoned, lack of respect from the surgeon, and disappointment with the outcome.

Conflict of Interest: None

Source of Funding: ARC

Increasing attention has focused on the spinal muscles with respect to stability and low back pain (LBP) with suggestions of a de-conditioning syndrome. What is less clear is the extent of this degeneration and whether it is a long term of short term consequence of LBP. This study sought to explore the cross section area (CSA) and muscle quality of the spinal extensor group in a subset of LBP patients.

MRI scans of 100 spinal clinic patients were retrospectively reviewed; sagittal and transverse (from levels L3-5) images were annoymised and archived along with details of age, gender and presenting symptoms. An image analysis package was used to determine CSA of the extensor muscle groups, and levels of fat infiltration were calculated using a pseudocolouring technique.

46 patients had spinal stenosis (28 males, 18 females, mean age 66±14.2 years) and 54 had a disc prolapse (28 males, 26 females, mean age 50±12.9 years). CSA was significantly smaller in the stenotics at both L3/4 and L4/5. Patients presenting with leg pain and a disc herniation had a significantly smaller CSA (p< 0.01) at L3/4 and L4/5 levels. A left right CSA asymmetry was noted but this was not specific to diagnosis, or presenting symptoms. Fat infiltration was present in both groups but was significantly greater in the stenotic group (p< 0.01) and was present at a similar degree at all spinal levels. Multiple regression analysis confirmed that reduced CSA was linked to leg pain (p< 0.01) and age was linked with fat infiltration (0< 0.01).

Conflict of Interest: None

Source of Funding: None

Rowing is associated with a high incidence of low back pain (LBP) often attributed to the associated loading and large trunk rotations. Here we examine electromyographic (EMG) activity in rowers who undertake sweep rowing (asymmetrical) or sculling (symmetrical).

22 right handed elite rowers participated and written informed consent was obtained. Each had a preferred rowing side (bow side [BS, n=6]; stroke side [SS, n=7) or sculling [SC, n=9]). Testing was performed in a Cybex isokinetic dynamometer and bilateral EMG activity recorded from trunk muscles (erector spinae [ES] and rectus abdominis [RA]) synchronously.

There were no differences between the groups in peak torque during isokinetic or isometric testing, although extensor torque was higher than flexor torque. Analysis of EMG activity revealed that scullers showed no left/right differences in any of the testing protocols. However, sweep rowers showed significant differences between left and right ES during extension protocols, in the isokinetic testing at 30°s⁻¹ (in the SS rowers [LES 0.11±0.01mV vs RES 0.08±0.01mV] and at 90°s⁻¹ in the BS rowers [LES 0.14±0.02mV vs RES 0.12±0.01mV]. In the isometric tests, the SS rowers showed higher left ES activity than the right [LES 0.11±0.01mV vs RES 0.09±0.01mV]. The flexion protocols did not reveal any left right differences in any groups in any of the protocols used. These results reveal that sweep rowing is associated with asymmetric activity of trunk extensors, but not flexors. This could be a contributing factor to the high incidence of LBP in sweep rowers.

The purpose of this study was to design a questionnaire to evaluate patients’ satisfaction with the healthcare system relating to their spinal procedure, and to gather information relating to pre and post operative management. If successful, this questionnaire will be incorporated into the FASTER (Function after spinal treatment, exercise and rehabilitation) study, with the aim of identifying common care pathways and to understand where stumbling blocks arise.

The questionnaire included three sections: Care before surgery, care after surgery, plus general measures of satisfaction. Patients were randomly selected from the hospital records if they had undergone a lumbar discectomy or lateral nerve root decompression within the past year; this included both NHS and private patients.

34 pilot questionnaires were sent, to date 18 have been returned (9 NHS and 9 private patients). It was found that 79% of patients went to their GP when first experiencing pain/discomfort; however, alarmingly, an overwhelming majority of these patients felt their problem was not dealt with correctly at this stage. Fifty percent of the patients who went through the NHS “Definitely” felt left alone to deal with their problem. Only 10% of patients had physiotherapy prior to surgery and none went to pain management classes. 32% of patients received physiotherapy after leaving hospital; however, in all but one case this was after returning with symptoms.

Despite this, patients in general were very pleased with the care they received during there hospital stay. This pilot data provides an insight into the issues experienced by spinal surgery patients.

Trunk flexor-extensor asymmetry has been implicated in the development of back pain; however, left-right trunk muscle asymmetry has received little attention. This study examined whether such left-right asymmetries exist and if these are related to differing sporting tasks.

Thirty-five subjects were recruited and written informed consent obtained; 12 subjects participated in unilateral (UL) sports e.g. racquet sports (mean age 21.6±0.7 (SEM) years), 13 in bilateral (BL) activities e.g. rugby (mean age 21.7±0.2) and 10 controls (C) not involved in sport (mean age 21.7±0.2) years). Isokinetic and isometric trunk flexions and extensions including a fatiguing isometric hold were performed in a Cybex isokinetic dynamometer synchronised with bilateral electromyographic (EMG) recordings from trunk extensors (erector spinae at L4), and flexors (rectus abdominis at T10). A ratio of left:right EMG activity was calculated for each set of muscles, to examine asymmetry.

No differences were seen in left:right extensor EMG ratios across any of the test protocols. However, the UL group had higher (P< 0.05) left:right flexor EMG ratios than the BL group during pre-fatigue (UL:1.32±0.15 vs. BL:0.84±0.07) and post-fatigue (UL:1.30±0.18 vs BL:0.84±0.07) isometric flexion. Torque data suggested that the trunk extensor-flexor ratio was larger (P< 0.05) in the BL group compared to the C in the isokinetic exercises at the 30°s⁻¹ (BL:1.27±0.05; C:1.00±0.06) and at the 90°s⁻¹ speeds (BL:1.28±0.05; C:0.95±0.08), but no differences were seen during isometric testing.

This study suggests that training for different sports can generate significant asymmetry in the trunk muscles, particularly in the flexors, the importance of which requires further research.

The FASTER study (Function after spinal treatment, exercise and rehabilitation) aims to evaluate, via a factorial RCT, the benefits of a rehabilitation programme and an education booklet for the postoperative management of patients undergoing discectomy or lateral nerve root decompression, each compared with “usual care”. Since the scientific literature reveals little evidence in favour of any specific exercises or approach, the rehabilitation programme had a general focus on simply getting people exercising and was based on Klaber-Moffett & Frost’s [2000] “Back to fitness” programme; classes include elements of stretching, strengthening, relaxation and an opportunity for discussion.

Currently, 128 patients have been recruited into the study of which 65 have been randomised to receive rehabilitation, which is offered 6 weeks after their surgery. At the end of the 6 week period of rehabilitation classes, participants are requested to complete a questionnaire containing forced and open questions on the content, style, length, timeliness and usefulness of these classes.

Feedback is very positive. In terms of class length 95% felt it was about right and easy to follow. All knew why they were doing the exercises, and 90% felt they had enough support and assistance during the classes. 95% would recommend to others. Important elements were noted to be; being with other people with the same problem, learning to exercise, gaining confidence and support and information from the staff. The average overall rating of the classes was 8.5/10.

The results show that content of the rehabilitation classes appears to be pitched at the right level for post-operative patients and that the attendees are benefiting from interactions with each other and learning to exercise and be active. The impact of these classes on outcome remains to be determined.

The FASTER study (Function after spinal treatment, exercise and rehabilitation) aims to evaluate, via a factorial RCT, the benefits of a rehabilitation programme and an education booklet Your back operation, www.tso.co.uk/bookshop, for the postoperative management of patients undergoing discectomy or lateral nerve root decompression, each compared with “usual care”. Included in this larger study is an evaluation of the booklet which forms the focus of this abstract.

To date, 128 patients have been recruited into the study of which 63 have been randomised to receive the booklet. At 3 months post-surgery all of these patients are requested to complete a questionnaire on the booklet. This questionnaire contained forced-choice questions on readability etc and open questions regarding content. Finally, patients were asked their overall rating of the booklet on a scale from 1 to 10.

Feedback is very positive. The average overall rating of the booklet was 8.3/10. Over 85% found it easy to read, interesting, and of appropriate length. Over 90% also stated they had learnt new and helpful information. All subjects stated that they would recommend the booklet to a friend, and the majority stated that they frequently referred to the booklet. The predominant messages received and understood by the patients were related to the safe benefits of early activation and return to normal activities.

The results show that spinal surgery patients appreciate evidence-based information in booklet form, and suggest that this booklet may be an important adjunct to post-operative management of spinal patients.

Clinical outcomes of surgery for disc herniation and spinal stenosis are variable. Surveys show that postoperative management is inconsistent; spinal surgeons and their patients are uncertain about what best to do post-operatively. Following a focused literature review, a patient-centred, evidence-based booklet was developed, which aims to reduce uncertainty, guide post-operative management and facilitate recovery. Initial peer and patient evaluations were encouraging and the booklet Your back operation (www.tso.co.uk/bookshop) is currently factored into a trial investigating the post-operative management of spinal patients.

To date, 80 patients have been recruited into the study of which 34 have been randomised to receive the booklet. At 6 months post-surgery all of these patients are requested to complete a questionnaire on the booklet. This questionnaire contained forced-choice questions on readability, style, information level, believability, length, content and helpfulness. Further open questions concern the booklet’s messages, giving patients the opportunity to identify anything they did not like or understand, voice any concerns that were not covered, and say if they thought the booklet would change what they did after surgery. Finally, they were asked their overall rating of the booklet on a scale from 1 to 10.

Feedback is very positive. The average overall rating of the booklet was 8.6/10. Over 80% found it easy to read, interesting, and of appropriate length. Over 80% also stated they had learnt new and helpful information. All subjects stated that they would recommend the booklet to a friend, and the majority stated that they frequently referred to the booklet. The predominant messages received and understood by the patients were related to the safe benefits of early activation and return to normal activities.

The results show that spinal surgery patients appreciate evidence-based information in booklet form, and suggest that this booklet may be an important adjunct to post-operative management of spinal patients.

Poor trunk extensor endurance is implicated in low back pain; less, however, is known about contributions of left and right sides and upper and lower parts to maximum torque production following fatigue. This study examines torque and electromyographic (EMG) activity in different parts of the left and right trunk extensors before and following a maximal voluntary contraction (MVC) hold.

16 student rowers participated and written informed consent was obtained. Testing was performed in a Cybex isokinetic dynamometer with synchronous bilateral EMG recordings (during brief MVCs) from the left and right the erector spinae (ES) muscles at vertebral levels T12 and L4, prior to and immediately after, and 1, 5 and 10 minutes after a 60 second MVC.

A small decrease in maximum torque was observed during 60s MVC, followed by a non significant step-wise increase. The torque at 10 minutes post MVC was the highest value recorded. EMG activity rose in the right upper back 5 and 10 mins following the fatigue. Furthermore, the ratios of left:right EMG activity revealed an increase compared to pre-fatigue values in the lower back but a decrease in the upper back, suggesting the task involved differential use of left and right sides in addition to upper and lower back muscles.

These results suggest that 60s MVC induces differential activation of left and right sides and upper and lower parts of the trunk extensors. The apparent potentiation in force and asymmetry of activation following the 60s MVC task requires further investigation.

Highly active anti-retroviral therapy has transformed HIV into a chronic disease with a long-term asymptomatic phase. As a result, emphasis is shifting to other effects of the virus, aside from immunosuppression and mortality. We have reviewed the current evidence for an association between HIV infection and poor fracture healing.

The increased prevalence of osteoporosis and fragility fractures in HIV patients is well recognised. The suggestion that this may be purely as a result of highly active anti-retroviral therapy has been largely rejected. Apart from directly impeding cellular function in bone remodelling, HIV infection is known to cause derangement in the levels of those cytokines involved in fracture healing (particularly tumour necrosis factor-α) and appears to impair the blood supply of bone.

Many other factors complicate this issue, including a reduced body mass index, suboptimal nutrition, the effects of anti-retroviral drugs and the avoidance of operative intervention because of high rates of wound infection. However, there are sound molecular and biochemical hypotheses for a direct relationship between HIV infection and impaired fracture healing, and the rewards for further knowledge in this area are extensive in terms of optimised fracture management, reduced patient morbidity and educated resource allocation. Further investigation in this area is overdue.

Background/purpose: Clinical outcomes of surgery for disc herniation and spinal stenosis are variable. Surveys show that post-operative management is inconsistent, and spinal surgeons and their patients are uncertain about what best to do during the recovery phase. The aim of this study was to develop a patient-centred, evidence-based booklet that spinal surgeons can give to their patients to reduce uncertainty, guide post-operative management and facilitate recovery.

Methods: A systematic literature search led to a best-evidence synthesis of appropriate information and advice on post-operative activation, restrictions, rehabilitation, and expectations about surgical and functional outcomes. Data were extracted into evidence statements which were graded by consensus for consistency and practicality so as to inform and prioritise the booklet’s messages. Following peer review (n = 16), a sample of patients (n = 11) gave a structured evaluation of the draft text.

Results: The review found scant evidence in favour of post-operative activity restriction, yet an early active approach to post-operative rehabilitation can improve clinical, functional and occupational outcomes. Thus, the text of the booklet presents carefully selected messages to reduce uncertainty, promote positive beliefs, encourage early reactivation, and provide practical advice to aid self-management. Peer reviewers’ comments were incorporated into the text; all the spinal surgeons (n = 7) said they would find the booklet useful. Patients found it readable, interesting and helpful; they understood and accepted the intended messages.

Conclusions: Following careful development, an evidence-based booklet to aid post-operative management in spinal surgery is now available, and is factored into a RCT of post-surgical rehabilitation.

Introduction: Preliminary studies suggest that prolonged retraction of the paraspinal muscle during spinal surgery may produce ischaemic damage. We describe the continuous measurement of intramuscular pressures (IMP) during decompressive lumbar laminectomy and the relationship to back pain and disability.

Methods: In this prospective interventional study, 28 patients undergoing surgery for lumbar canal stenosis were recruited. Back pain and function were assessed using the Visual Analogue Score (VAS), Oswestry Disability Index (ODI) and Short Form 36 (SF36) health survey. During surgery, IMP was continuously recorded from the multifidus muscle using a pressure transducer. The intramuscular perfusion pressure (IPP) was derived as the difference between the patient’s mean arterial pressure (MAP) and IMP (IPP = MAP − IMP). The data was analysed using repeated measures ANOVA (SPSS package).

Results: The mean age was 60.4 ± 3 years and the mean duration of symptoms of 31.0 ± 6 months. The predominant symptoms were neurogenic claudication (14) and/or sciatica (13). Patients underwent 1 (N=3), 2 (N=20) or 3 (N=5) level laminectomies. The muscle retractors used were Norfolk and Norwich (N=16) and McCullock (N=12). The mean duration of deep muscle retraction was 68.5 ± 9 mins (range 19–240). On application of deep muscle retraction, there was a rapid and sustained increase in IMP (F=26.8; p< 0.001; repeated measures ANOVA), and overall the calculated mean IPP approached 0 mmHg or less during this period (F=36.8; p< 0.001). On release of deep muscle retraction there was a rapid decrease in IMP to pre-operative levels. The IPP was greater with Norfolk and Norwich than McCullock retractors (F=12.2; p< 0.001). Compared to pre-operative values, there was a decrease in ODI (F=18.6; p< 0.001) and VAS for back pain (F=9.9; p< 0.001) at discharge, 4–6 weeks and 6 months, post-operatively. Compared to pre-operative values, there was a decrease in SF36 scores at 6 months (F=26.7; p< 0.001). Total duration of muscle retraction over 60 mins was associated with higher VAS scores for back pain at 4–6 weeks and 6 months postoperatively (F=3.7; p< 0.01). There was no relationship between IPP and post-operative ODI or VAS for back pain.

Conclusions: This study demonstrates a simple technique for the continuous monitoring of IMP during spinal surgery, from which the IPP can be derived. Comparison of two muscle retractors has shown that the McCullock retractor generates a higher IMP than Norfolk and Norwich retractor. Decompressive lumbar laminectomy improves the VAS for back pain and ODI and SF36 outcome scores in these patients. The results show that duration of muscle retraction, rather than extent of the pressure generated by the retractor, is related to postoperative back pain.

This study sought to determine the post-operative management of spinal patients in the UK, and to determine if uniformity exists between surgeons and if there is any published evidence for this practice.

A reply-paid questionnaire was sent to members of the British Association of Spinal Surgeons and the Society for Back Pain Research. The questionnaire documented the surgeon’s experience, where they work, their operative population, the types of spinal surgery performed, and whether they have a routine for post-operative management or any written instructions for patients concerning post operative management. It also asked about the nature and duration of professionally supervised rehabilitation. Of the 89 questionnaires distributed, 63 (71%) were returned, of which 51 could be used in the analysis. The 12 not used were either completed incorrectly, had missing data or the surgeon had since retired. The replies demonstrated wide variation: only 35% of surgeons provide their patients with written post-operative instructions; there was limited referral to physiotherapy, with only 45% referring to a physiotherapist (for an average of 1.8 sessions); only a modest fraction of surgeons advocated the use of a post-operative corset (18%), others restricting sitting or encouraging bed rest; and a range of recommendations regarding return to work. There was also only a limited correlation between restrictions on sitting and recommendations about return to sedentary work or driving (Spearman r=0.08 and 0.36, respectively).

In summary, although individual surgeons may be certain of their practice, the overall variation indicates ongoing uncertainty across the profession. This was further substantiated by our literature search, which revealed limited evidence for current practices, and a paucity of research into postoperative management.

The purpose of this study was to assess the technique of ultrasonographic evaluation of anterior shoulder translation from an anterior approach.

Anterior translation in the right shoulders of 23 volunteers was evaluated using ultrasound with a 10 MHz, 6 cm wide linear transducer. A translatory force of 90 Newtons (N) was used to translate the humeral head in the adduction and internal rotation position (Position 1), while 60 N was used in the more clinically relevant position of 90° abduction and external rotation position (Position 2).

The overall intraobserver coefficients of variation ranged from 0–13% (mean 3.8 ± 2.5%) for examiner 1 and 0.5–20.9% (mean 5.1 ± 3.9%) for examiner 2. The overall interobserver variation ranged from 0–29.8% (mean 9.3 ± 7.3%). The anterior translation in Position 1 ranged from –2.6 to 12.9 mm (mean 2.1 ± 3.1 mm) for examiner I and from −4.1 to 4.7 mm (mean 1.1 ± 2.2 mm) for examiner II. The anterior translation in Position 2 ranged from −3.3 to 3.7 mm (mean 0.3 ± 1.9 mm) for examiner I and from −8.3 mm to 4.5 mm (mean −0.7 ± 2.6 mm) for examiner II. The intraclass correlation coefficients (r) for the measured anterior translation between the 2 examiners for the 2 positions were 0.029 and −0.058 respectively.

The interobserver coefficient of variation remains excessive and there was poor agreement in the measured anterior translation. The finding of negative values in the measured anterior translation despite translatory force raises further concerns about the prospective clinical use of this technique at the present moment.

Arthroscopic stabilisation of the shoulder is a technically-demanding and developing technique, and the reported results have yet to match those for open surgery. We present a consecutive initial series of 55 patients with post-traumatic recurrent anteroinferior instability managed since September 1999 using a titanium knotless suture anchor. Patients were reviewed from 12–33 months postoperatively and assessed using the Rowe, Walch-Duplay and Constant scores. Following mobilisation of the capsulolabral complex, labral reconstruction was achieved using a two-portal technique and an average of three anchors placed on the glenoid articular rim. In 13 cases, additional electrothermal shrinkage was required to reduce capsular redundancy in the anterior and inferior recesses following labral repair, although 11 of these were in the first 18 months. Incorporation of a south-to-north capsular shift has reduced the need for supplementary shrinkage. Complications have included one instance of anchor migration requiring open retrieval and two documented episodes of recurrent instability, although these occurred in patients having surgery within the first six months after the introduction of this technique. Based on our initial experience, we believe that arthroscopic labral repair is a viable alternative to open Bankart repair and have now expanded the indications to include patients with primary dislocation, those participating in gymnastic and contact/collision sports, and revision cases with failed open repairs.

Aim of Study: The aim of the study was to investigate the effect of muscle retractors on intramuscular pressure in the posterior spinal muscles during posterior spinal surgery.

Methods: Twenty patients undergoing posterior spinal surgery were recruited into this study and recordings of intramuscular pressure during surgery were performed using a Stryker® compartment pressure monitoring system, prior to insertion of retractors, 5, 30 and 60 minutes into surgery and on removal of retractors. Prior to and following use of the retractors, muscle biopsies were taken from the erector spinae muscle for analysis.

Results: A significant increase in intramuscular pressure (p< 0.001) was observed during surgery, with pressure rising from 7.1±4.1 mmHg pre-operatively to 26.4±16.0 mmHg 30 minutes into the operation. On removal of retractors, this pressure returned to or near to the original value. Analysis of muscle biopsies using calcium-activated ATPase birefringence revealed a reduction in muscle function following prolonged use of self-retaining retractors.

Discussion: This study demonstrates a substantial rise in pressure in the erector spinae muscle during posterior spinal surgery. Following retraction, marked changes were noted in the function of the muscles. This could be an important factor in the generation of operative scar tissue and post-operative dysfunction of the spinal muscles, and therefore, may be a cause of persistent back pain frequently observed in post-operative patients. Currently, this work is being extended to investigate the relationship between loss of muscle function and duration of retraction, and to study the long term implications of loss of muscle function with respect to surgical outcome and chronic back pain.

Purpose & Background: The spinal muscles are increasingly being linked to spinal complaints. However, little is known regarding the corticospinal control of these muscles. Corticospinal pathways can be activated using transcranial magnetic stimulation (TMS) applied over the motor cortex. This study uses TMS to assess corticospinal input to the paraspinal muscles in the thoracic region.

Methods: Ten individuals (mean [± SD] age 33 ± 10 yrs; mean height 166 ± 10 cm; two left-handed; five male, five female) with no history of neurological disorder were recruited into this study and written informed consent obtained. Subjects lay prone in a relaxed position with the head unsupported. Surface electromyographic (EMG) recording electrodes were positioned bilaterally over the paraspinal muscles adjacent to thoracic spinal processes T1 and T2. TMS was applied using a MagStim 200 stimulator connected to a double cone coil with its cross-over positioned over the vertex so that the maximum induced current flowed in a posterior to anterior direction. The stimulus intensity was adjusted in steps of 5% of the maximum stimulator output (MSO), and ten stimuli were delivered at each strength. Threshold for a motor evoked potential (MEP) in each muscle was determined as the minimum intensity that would evoke MEPs to 50% of stimulus presentations. Latency of MEPs was determined by measuring the time between the stimulus and the start of the first deflection in the MEP. The procedure was repeated for the other pairs of thoracic segments between T3 and T12.

Results: In all subjects, it was possible to evoke MEPs in relaxed paraspinal muscles at all thoracic levels. Mean (±SEM) threshold for evoking a MEP on the left side increased from 47 ± 2.5 %MSO at level T1 to 55 ± 2.5 %MSO at T12 (Pearson correlation, P< 0.05) but remained more constant (P> 0.05) on the right side (T1, 55 ± 3.9 %MSO; T12, 57 ± 3.3 %MSO). Over all levels tested, mean threshold for MEPs was 3.9 ± 0.6 %MSO higher on the right than the left side (Student’s paired t-test, P< 0.05). Mean latency of MEPs on the left increased from 11.9 ± 0.7 ms at level T1 to 15.5 ± 0.6 ms at T12 and on the right from 12.3 ± 0.5 ms at level T1 to 16 ± 0.7 ms at T12 (Pearson correlation, P< 0.05). Throughout the thoracic region, latency of MEPs was 0.8 ± 0.2 ms longer on the right than the left side (Student’s paired t-test, P< 0.05).

Conclusion: The latency of MEPs increased as recordings were made from muscles innervated more caudally. Threshold for MEPs varied between subjects and at different spinal levels but our results indicate that it was higher at more caudal levels, perhaps suggesting weaker corticospinal innervation. Threshold was lower and latency shorter for muscles on the left side raising the interesting possibility that paraspinal muscles have some asymmetry in their corticospinal innervation. This study has provided us with baseline electrophysiological data allowing us to investigate the voluntary control pathways to muscles stabilising the thoracic spinal cord following trauma or disease.

Purpose & Background: Posteroanterior mobilisation (PA) is a manual physiotherapy technique that is commonly used as an examination tool and a form of conservative treatment for spinal complaints. The efficacy of this technique is controversial and this may be in part due to a limited knowledge of the mechanical and physiological mechanisms underlying this technique. This study aims to evaluate the ability of interventional MRI to image the mechanics of mobilisation in terms of spinal movement and soft tissue deformation during a PA mobilisation.

Methods: 5 normal subjects (4 female, 1 male, mean age 29.6 ± 3.9 years) with no current or history of neck pain requiring intervention were recruited into this study, and written informed consent obtained. Subjects were scanned using a General Electric Signa SP10 Interventional MRI scanner (iMR). This is an open MRI scanner consisting of 2 connected but opposing ring “doughnut” magnets. The gap between these magnets is 56 cm generating a uniform field of 0.5Tesla. Subjects were scanned in the prone position with their necks in either a neutral or flexed position. In each position, subjects underwent a PA mobilisation to the 2nd and 6th cervical vertebrae. Sagittal and axial images of the spine were obtained prior to, during and following the mobilisation. Measurements of intervertebral rotation and translation were obtained from the sagittal images, and measures of soft tissue compression with respect to the spinous process were obtained from the axial images. Paired analysis of variance was used to investigate the impact of the mobilisations in each position.

Results: Clear images of vertebral position could be obtained if the mobilisation was sustained once the appropriate force had been delivered. From these images, it is possible to measure vertebral angulation, translation and soft tissue compression. From these measures, it became clear that intersegmental vertebral angulation and translation did not alter as a result of the force applied regardless of cervical position. However, marked and significant changes were seen in terms of soft tissue compression and in some instances overall angulation of the cervical spine.

Conclusion: This pilot work suggests that it is feasible to use iMR technology to study the mechanics of spinal mobilisation. Preliminary findings suggest that there is little or no displacement of the vertebral bodies as a result of an AP mobilisation, although there is considerable soft tissue compression.

Low back pain (LBP) is a common problem in rowers of all levels. Few studies have looked at the relationship between rowing technique, the forces generated during the rowing stroke and the kinematics of spinal motion. Of particular concern with respect to spinal injury and damage are the effects of fatigue during long rowing sessions.

A technique has been developed using an electromagnetic motion system and strain gauge instrumented load cell to measure spinal and pelvic motion and force generated at the oar during rowing on an exercise rowing ergometer. Using this technique 13 elite national and international oarsmen (mean age 22.43 ± 0.02 years) from local top squad rowing teams were investigated. The test protocol comprised of a one hour rowing piece. During this session rowing stroke profiles were quantified in terms of lumbopelvic kinematics and stroke force profiles. These profiles were sampled at the start of the session and quarterly intervals during the hour piece.

From this data we were able to quantify the motion of the lumbar spine and pelvis during rowing and relate this to the stroke force profile. The stroke profiles over the one hour piece were then compared to examine the effects of fatigue. This revealed marked changes and increases in the amount of spinal motion during the hour piece suggesting that to maintain stroke force profiles athletes were utilising greater ranges of spinal motion. The relevance of this with regard to low back pain however, requires further investigation.

There is a paucity of information regarding patient rated expectations of surgery and measures of satisfaction with surgery in terms of specific outcome measures such as pain. The aim of this study was to investigate patient expectations of surgery and short and long term satisfaction with the outcome of decompressive surgery in terms of pain, function, disability, general health.

Eighty-four patients undergoing spinal stenosis surgery were recruited into this study. On recruitment into the study patients were also asked to rate their expectations of improved in pain, general health, function etc. In addition at each review stage patients were asked to rate their satisfaction in improvement of these key outcome measures.

These demonstrated that patients had very high expectations of recovery particularly in terms of pain and function and that patients were confident of achieving this recovery (76.8%) confident of a good result. Levels of satisfaction however, varied considerably. 41% of subjects were 50% satisfied with the outcome, whilst 30% were dissatisfied. Most patients felt that they had made the right decision to have surgery although the surgery had only achieved 43.4% ± 37.8 of the outcome they had expected.

Examination of patient’s expectations of and satisfaction with surgery revealed that frequently patients had unrealistic expectations of their surgery and as a consequence tended to have lower levels of satisfaction.

The majority of studies investigating the outcome of lumbar decompression surgery have been retrospective in nature and have not used validated measures of outcome. The aim of this study was to prospectively investigate the short and long term outcome of lumbar decompression surgery in terms of function, disability, general health and psychological well being.

Eighty-four patients undergoing lumbar spinal stenosis surgery were recruited into this study. Patients were assessed using validated measures of outcome pre-operatively, and at 6 weeks, 6 months and one year post-operatively.

A significant reduction in pain (p< 0.001) was observed at the 6 week post-operative stage, this did not change at the subsequent assessment stages. Only some of the SF~36 categories were sensitive to change. The sub-categories that were sensitive to change were; physical function (p< 0.05); bodily pain (p< 0.001); and social function (p< 0.05). Improvements were observed in these categories at the 6 week and 6 month reviews. A gradual reduction in the Oswestry Disability Index (ODI) was observed with time, with changes principally being observed between the 6 week and 6 month review, and 6 week and one year review stages (p< 0.05). Minimal changes were observed in the psychological assessments with time. The outcome of surgery could not be predicted reliably from psychological, functional or pain measures.

Lumbar decompression surgery leads to a reduction in pain and some improvements in function.