Purpose: To review the oncologic outcomes following treatment of soft tissue sarcomas in the foot and ankle, and to determine the results of limb salvage surgery in this anatomically constrained area with often expected close pathologic margins.

Method: One hundred twenty-nine patients with soft tissue sarcomas of the foot were treated at our institution since 1986. Average age at presentations was 55 years old. Females and males were equally represented. Most common diagnosis was MFH in 31 patients, followed by leiomyosarcoma in 16 patients, synovial sarcoma in 13, and clear cell sarcoma in 6, the remainder being other soft tissue sarcomas. Most of sarcomas were intermediate or high grade. Our follow-up averaged 58 months.

Results: Limb salvage surgery was possible in 97 patients. Of those, negative margin excision was achieved in 75 patients, 18 patients had micro-positive margins, and 4 had grossly positive margins. Fifty-three patients in the limb salvage group required free tissue transfer for coverage. Of 97 limb salvage patients, 82 received radiation therapy, 5 patients received chemotherapy. Local recurrence occurred in 24 patients. Two of these were amenable to re-excision, the remaining required amputation. Thirty-two patents developed systemic disease. Average disease-free survival for patients with recurrent disease was 23 months. At last follow-up, 78 patients were alive with no evidence of disease and 24 were alive with disease. Seventeen patients died of disease, and the remainder of other causes.

Conclusion: In the setting of soft tissue sarcoma in foot and ankle, amputation rate is higher than in other anatomic areas. However, limb salvage surgery can be achieved with good oncological outcomes despite often unavoidable close margins. Soft tissue reconstructive procedures aid in achieving good surgical results while radiation therapy aids local control. Given these results, limb salvage in soft tissue tumors of foot and ankle should be the goal.

The benefit of open stabilization for recurrent shoulder instability is well known, however there have been recent reports of postoperative dysfunction of the subscapularis tendon following open shoulder surgery (Habermeyer et al, Scheibel et al). We present our findings in patients who have undergone an open anterior stabilization using a subscapularis split approach.

We reviewed 48 patients (49 shoulders), who were treated by the senior author (SB) from 2003–2005. They all underwent an open anterior stabilization of shoulder through a deltopectoral approach, with a subscapularis split technique, without any lateral tendon detachment. The minimum follow-up was 2 years, with average 34 months. Thirty-eight shoulders underwent an isolated anterior stabilization (1 bilateral) and 11 patients had additional procedures (8 bone grafts, 1 SLAP repair, 1 cuff repair, 1 anterior and posterior repair). There were 41 male and 7 female patients, and the mean age was 23.9 years (range 15–47 years). All patients were involved in sports and 45 had presented with recurrent dislocations. Patients were followed up using the Oxford instability score and the Rowe score questionnaires. All had a clinical examination for range of movement, stability, subscapularis muscle function, or signs of dysfunction. All had a MRI to assess the quality of the subscapularis muscle and tendon.

Mean postoperative Oxford instability score was 22.5 and the Rowe score was 69.38. Two patients had redislocated following re-injury. There was no evidence clinically of subscapularis dysfunction and the muscle and tendon were normal on all MRI scans. External rotation was reduced by a mean of 15.6 degrees. There was no significant loss of flexion or abduction. 81% of patients returned to their previous level of sport.

With a subscapularis split technique for anterior shoulder stabilization there is no significant postoperative dysfunction or damage to the subscapularis muscle, and most patients return to their previous level of sport.

Biologic resurfacing of the glenoid combined with surface replacement hemiarthroplasty for relatively young patients suffering from advanced glenohumeral arthritis has the advantages of both humeral head and glenoid bone preservation. The longer term results of this procedure are reported.

Twenty two shoulders in 21 patients had a surface replacement hemiarthroplasty with resurfacing of the glenoid with the anterior capsule. At follow up one had died, and another was not contactable. The prosthesis was removed in one for deep infection, and the fourth patient had undergone revision to a total shoulder arthroplasty for ongoing pain. Therefore, 17 patients with 18 operated shoulders were available for clinical assessment. The average age of the patients was 54.8 years (35–78) at the time of surgery.

The average length of follow-up was 4.8 years (2–10.6). The average Constant Score was 71.4 points (41–95), and the sex- and age-adjusted Constant Score was 83.9%. The mean ASES score was 74.4 points (35–100). The average arc of forward flexion was 130 degrees (100–160), and external rotation was 39 degrees (20–60). On a VAS scale of 0 to 10, the average pain score at rest was 0.5 (0–3), while pain with activity was 2.4 (0–6). Sixteen of the 17 patients (94%) had a satisfactory result, and would have the operation again. Eight of the 17 patients (47%) were able to return to their previous sporting activities. Radiographic follow-up demonstrated there were 2 mild and 2 moderate cases of superior subluxation of the humeral head. There was no subsidence or signs of loosening of any humeral prosthesis. The average glenohumeral joint space was 0.13mm (0–2). Glenoid erosion was none in one case, mild in 6 cases, moderate in 6 cases, and severe in 3 shoulders.

Although the results of this procedure compare favourably with other series, the extent of glenoid erosion is concerning. A more robust tissue for interposition may give better results

Objectives: To investigate whether components of MSTS-87 (Pain, ROM, Strength, Stability, Deformity, Acceptance and Function) correlate with function as measured by TESS following endoprosthetic replacement (EPR) for patients with bone sarcoma.

Methods: 255 patients with extremity bone sarcoma treated by resection & EPR were identified from a prospective database. From this group we investigated 111 patients with primary bone sarcoma with > 2 years follow up, evaluated by both MSTS-87 & TESS, no local recurrence, metastasis or major complication for at least 2 years prior to the follow-up. Upper extremity patients were excluded due to small numbers. We examined the influence of patient demographics and tumour characteristics on functional outcome scores. Correlation between MSTS-87 & TESS was performed using linear regression analysis.

Results: Age, gender, tumour size, anatomical site, chemotherapy treatment and presence of pathological fracture did not significantly correlate with TESS. Linear regression analysis of MSTS-87 individual criteria and total score revealed that only pain, ROM and function helped explain the TESS score (p < 0.05) while strength, stability, deformity & acceptance had no significant effect on overall functional outcome.

Conclusions: Of the seven MSTS-87 variables, only pain, ROM and function significantly correlate with overall functional outcome as measured by TESS following EPR for bone sarcoma. This suggests that patients with decreased strength, stability, deformity and acceptance as defined by MSTS-87 scores, may still adapt well with good overall functional outcomes.

Bone allograft use in trauma and orthopaedic surgery is limited by the potential for cross infection due to inadequate acceptable decontamination methods. Current methods for allograft decontamination either put the recipient at risk of potentially pathogenic organisms or markedly reduce the mechanical strength and biological properties of bone. This study developed a technique of sterilization of donor bone which also maintains its mechanical properties.

Whole mature rat femurs were studied, as analogous to strut allograft. Bones were inoculated by vortexing in a solution of pathogens likely to cause cross infection in the human bone graft situation. Inoculated bones were subjected to supercritical carbon dioxide at 250 bar pressure at 35 degrees celsius for different experimental time periods until a set of conditions for sterilization was achieved. Decontamination was assessed by vortexing the treated bone in culture broth and plating this on suitable culture medium for 24 hours. The broth was also subcultured. Controls were untreated-, gamma irradiated- and dehydrated bone. Mechanical testing of the bones by precision three-point bending to failure was performed and the dimensions and cross-section digitally assessed so values could be expressed in terms of stress.

Mechanical testing revealed bone treated with supercritical carbon dioxide was consistently significantly stronger than that subjected to gamma irradiation and bones having no treatment (due to the minor dehydrating effect of the carbon dioxide). Terminal sterilization of bone is achieved using supercritical carbon dioxide and this method maintains the mechanical properties.

The new technique greatly enhances potential for bone allograft in orthopaedic surgery.

A technical goal in total knee arthroplasty is the production of a neutral coronal plane mechanical axis. Errors may produce large mechanical axis deviations precipitating early implant failure. This study sought to test if measured distal femoral resection produced more accurate and consistent coronal alignment than arbitrarily set distal femoral resection.

Data from a cohort of 255 consecutive unselected primary total knee arthroplasties undertaken by the senior author (PM) was collected prospectively and independently assessed. In the first 167 cases distal femoral resection was arbitrarily set to 5 degrees of valgus. In the remaining 88 cases the distal femoral resection angle was determined on a preoperative long leg standing AP radiograph. Postoperative coronal alignment was measured on long leg standing AP radiograph in all cases.

The measured distal femoral valgus angle was between 4 and 7 degrees. An equal number measured either 5 or 6 degrees and accounted for 85% of the total number. Statistically insignificant improvements in mean axis and standard deviation were observed in the measured group: mean axis deviation −0.31 vs −0.51: p=0.17 (independent samples t test) and standard deviation 0.91 vs 1.09: p=0.055 (Levene test).

Acceptable coronal alignment in total knee arthroplasty can reliably be obtained with conventional instrumentation. Improvement in standard deviation with measured distal femoral valgus angle approaches statistical significance.

Deterioration in knee joint proprioception has been postulated to occur following injury, resulting in further instability due to disruption of receptors and feedback mechanisms. Surgical reconstruction techniques may also influence post-operative proprioceptive ability (PA). We hypothesised that anterior cruciate ligament (ACL) reconstruction techniques which disrupt the knee capsule would result in a decrease in PA.

Following ethical approval, a total of 48 subjects (mean age: 28.1 ± 10.5, 34 male, 14 female) undergoing ACL reconstruction surgery were included in the study. Fifteen subjects underwent “open” capsule ACL surgery and patellar tendon graft, whereas 33 subjects had “closed” capsule surgery with a hamstring tendon graft. Knee proprioception was measured on a custom-designed test apparatus incorporating electromagnetic position sensors (Polhemus Fastrack) located on femoral and tibial landmarks to accurately track knee angle during flexion-extension (no load). Leg flexion-extension under partial weight-bearing (5kg) was also evaluated. Pre-operative PA was assessed bilaterally, and then again on operated joints at three, six and twelve months post-op. Proprioceptive ability was measured as the cumulative absolute error in knee angle (°) between five repeat measurements and a target angle.

We observed no significant difference in PA between injured and contralateral knees prior to ACL reconstruction. Post-operatively, no significant difference in PA was observed between “open” versus “closed” ACL techniques, irrespective of loading conditions. While trends indicated that PA during knee extension (no load) and leg flexion (partial weight-bearing) improved over the 12 months compared to pre-operative values in closed ACL surgery, these were not significantly different to open ACL results.

The proportion of subjects whose PA improved in at least two out of the three post-op evaluations was also similar (approx 50%) across all groups, irrespective of joint loading. The only difference was PA during leg flexion under partial weight bearing, where 27% of open ACL surgery patients showed improvement in two or more follow-up tests, as opposed to 58% of closed ACL surgery patients.

We present a method to determine pre- and postoperative PA during knee flexion/extension under no load as well as under partial weight-bearing. We saw no significant difference in PA of the knee under no-load versus load. We also saw no significant difference in postoperative PA following open capsule, patellar tendon graft versus closed capsule, hamstring tendon graft ACL reconstruction technique after 1 year follow-up.

Distraction osteogenesis (DO) is useful for bone lengthening and deformity correction. Unfortunately, this often requires prolonged use of an external fixator with concomitant morbidities. This study investigates whether low-magnitude, high-intensity vibrations (Dynamic Motion Therapy, DMT) can accelerate maturation of regenerate bone in DO, thus reducing the duration of external fixation. 28 NZ White Rabbits underwent a right mid-tibial osteotomy with application of an Orthofix M-103 fixator (Orthofix, Busselengo, Italy). Distraction commenced on day 3 at 0.5 mm every 12 hours for 12 days. All animals were sacrificed on day 45. Animals were randomly assigned into 4 groups:

control group;

DMT was applied with the Juvent platform (Juvent, Somerset, NJ) for 10 minutes/day. X-ray and CT scans were taken prior to mechanical testing. All specimens were processed for histology. X-rays and CT scans showed evidence of cortical remodelling and re-establishment of the medullary canal in animals treated with DMT (groups 2, 3 and 4). This was most pronounced in animals treated during the distraction and consolidation phases (group 4). Regenerate bone in the control group (group 1) was more disorganised, with a delayed union evident in 1 animal. Group 1 achieved peak torque and stiffness values of 70% and 50% of the contralateral (unoperated) tibia respectively. No significant difference was seen in peak torque and stiffness between groups 2, 3, and 4, however each was significantly higher than group 1 (P< 0.05). H& E staining revealed less porosity in the newly formed cortical bone and a more defined medullary canal in animals treated with DMT than in the control group. Low-magnitude, high-intensity vibrations appear to accelerate cortical remodelling and reestablishment of a medullary canal. Regenerate bone in animals treated with DMT was also mechanically superior. The timing of DMT therapy did not appear to be important. Further studies are required to determine the optimal timing and duration of DMT therapy.

Infrapatellar Contracture Syndrome describes a postoperative complication characterised by a vertical migration of the patella due to Patella Tendon (PT) shortening and/or PT adhesion (PTA) formation. We investigated how removal of the central one-third of the PT influences both PT length (LP) and in vitro knee kinematics in 18 sheep divided into 3, 6, 12 and 24 week groups. At time of sacrifice the pelvis-lower extremities complexes were left in a supine position until rigor mortis set in. Limbs were CT-scanned (0.5mm) whilst frozen and LP measured (ProEngineer, PTC, MA). Specimens were fixed into a loading frame with 50N applied to the rectus femoris and knee kinematics obtained (Polhemus, VT). Bones and associated registration block portions of the receiver assemblies were CT-scanned (0.5mm), reconstructed, and imported into ProEngineer where coordinate systems were created in accordance with the Joint Coordinate System (JCS). Registration was accomplished by aligning models of the receiver assemblies with the reconstructed surfaces. Post-processing and statistical analysis (ANOVA) was performed using Matlab (MathWorks, MA) and data referenced to the contralateral controls.

No significant changes in LP were observed. The mean PT length ratio (LP/LC) in the 3 week group was 1.0028±0.004 (mean±SD). In the 6 week group this ratio had increased to 1.0282±0.0246, returning to 1.005±0.0035 at 12 weeks and back to 1.0159±0.0217 at 24 weeks. No PTA’s were observed. A significant proximal shift of the patella reflecting the increase in LP was observed which correlated well with a retardation of patellar flexion (r = 0.880, p< 0.001). A significant decrease in medial patellar tilt was also observed but was not coupled with changes in tibial rotation. Proximal and lateral tibial shifts were also detected.

The results of this study seem to suggest that the changes in knee kinematics and LP induced by removal of the central one-third of the PT do not recover 24 weeks post-operatively.

Introduction: Systematic reviews have found that sitting at work is not associated with LBP, although the biomechanical evidence does offer plausible causative mechanisms. Indeed, exposure to lumbar postures has been assessed using imprecise tools that have limited epidemiological investigations. The aim of this study was to use new technology to measure the seated lumbar postures of sedentary (call centre) workers, and survey their current and future symptoms in order to determine associations with LBP.

Methods: A fibre-optic goniometer (FOG) system was attached to the lumbar spine and hip of 181 sedentary call centre workers at the start of their working shift. The lumbar FOG provides a continuous measure of sagittal lumbar curvature (lumbar position and movement), whilst the hip FOG enables quantification of sitting time. Baseline and 6-month follow-up questionnaires were used to collected symptom data, and logistic regression was used to determine associations between postural and symptom (yes/no) data.

Results: Workers spent a mean proportion of 83% of work-time sitting, with 17% sitting for more than 90 minutes without a break. Current LBP (symptoms lasting more than 24hrs) was associated with a kyphotic (mean lumbar angle> 180°) sitting posture (yes/no) (OR 2.1, 1.1–4.1), although movement (mean standard deviation and angular velocity °sec-1) in sitting was not. Sitting relatively static (AV< 4.26° yes/no) (OR 3.30, 1.06–10.25), using a small amount of range (SD< 10.2° yes/no) (OR 3.79, 1.2–11.7), and adopting a kyphotic posture (yes/no) (OR 2.75, 1.02–7.3) all significantly increased the risk of future LBP.

Discussion: Sitting postures at work are associated with current LBP and are statistically significant risks for recurrence. These results highlight the potential for ergonomic interventions to reduce current symptoms and the risk of future episodes. The findings from this study are novel, and the FOG system should now be used in larger investigations of sedentary risk factors for LBP.

Radiation induced pathologic fractures present a difficult problem for musculoskeletal oncologists. The purpose of this study was to determine the outcomes of management of radiation-induced pathologic fractures in a group of patients who had previously undergone combined management of extremity soft tissue sarcoma.

A review of our retrospective database was undertaken. From 1986 to present, thirty-two patients with soft tissue sarcomas were found to have radiation induced pathologic fractures. The records of these patients were reviewed for patient demographics, tumour size and anatomic site, presence of periosteal stripping at time of surgery, radiation dose, time to fracture, fracture treatment and fracture outcome.

There were twenty-three females and nine males with a mean age of sixty-three (range thirty-six to eighty-nine) years. Fractures occurred at a mean of forty-five months after resection of the sarcoma (range three to one hundred and fifty months). Anatomic distribution of fractures were : proximal femur(twelve), femoral diaphysis (eight), distal femur (two) tibia (five), acetabulum (two), metatarsal (two) and patella (one). Periosteal stripping was performed in half of the patients. Twenty-three patients had received high dose radiation (6600Gy). Seven fractures were managed conservatively while twenty-five were treated surgically. Only eleven of the thirty-two fractures united. Six patients underwent amputation, three for local recurrence and three for non-union of their fracture. Eight patients ultimately underwent arthroplasty, while seven patients have persistent non-unions. In the proximal femur, only three out of twelve fractures healed while six patients eventually underwent arthroplasty and three continue to have non-unions. Of eight femoral diaphyseal fractures, only one united. Patients who eventually underwent prosthetic replacement had good function and pain relief.

Radiation induced pathologic fractures are a difficult clinical problem. In particular patients with fractures in the proximal femur often undergo multiple attempts at fixation before definitive management with resection and endoprosthetic replacement. Fractures of the femoral diaphysis rarely heal despite aggressive surgical management. Primary arthroplasty may be considered in some patients as an alternative to fixation in radiation-induced pathologic fractures of the femur in order to avoid long term morbidity and repeated operations.

The purpose of this study was to evaluate the impact of dalteparin use on transfusion rates and blood loss in patients undergoing primary total joint arthroplasty at our center.

We prospectively studied the transfusion patterns of 1642 patients who underwent primary total hip or knee arthroplasty between January 2004 and December 2005 by five arthroplasty surgeons. The influence of daltaperin use, release of tourniquet in total knee arthroplasty, and the turnover of house staff were analyzed using SPSS V14.0 statistical software.

We identified seven hundred and three total hip and nine hundred and thirty-nine knee arthroplasty patients. The mean haemoglobin drop was statistically significant between 2004 and 2005 (p< 0.001). This was seen in both hip (p=0.014) and knee (p< 0.001) patients. Subgroup analysis of total knee arthroplasty revealed a significant difference in haemoglobin drop between surgeons who released the tourniquet prior to closure compared to release at the end of the case (p=0.005). In addition, there were significant monthly differences that corresponded with the turnover of house staff (p=0.039). Overall, no statistically significant increase in allogeneic transfusion rates was observed between years, months, and individual surgeons.

The use of dalteparin was found to be associated with a significantly increased haemoglobin drop in primary total joint replacement when compared to warfarin. However, the use of dalteparin was not associated with an increase in allogeneic transfusions at our center. The results also suggest that there may be an advantage to releasing the tourniquet and achieving hemostasis prior to closure in knee arthroplasty. Finally, the results emphasise the importance of educating new house staff on methods to reduce intra-operative blood loss and transfusion rates.

Background: Many sedentary workers will experience low back pain (LBP) whilst sitting, and some will believe that work caused their symptoms. They also report that their symptoms can be aggravated or relieved by work. Little is known about sedentary workers’ beliefs about the causes of back pain or symptom modifying factors (SMFs), and this study sought to determine their influence on absence.

Methods: 600 call centre workers completed validated questionnaires concerning beliefs about work-related causes of LBP in sedentary work and SMFs. Three constructs for work-related causes of LBP (physical demands; work environment; work organisation), and three groups of SMFs (physical aggravating; movement relieving; and postural relieving factors) were measured. A 6-month follow-up survey identified workers who did and did not take absence due to LBP. Logistic regression was used to predict future absence.

Results: Results indicated that, on their own, beliefs about the work environment (OR 1.2, 95% CI 1.1–1.4), and work organisation (OR 1.2, 95% CI 1.0–1.3) were significant risks for future absence (P< 0.001). Physical aggravating factors also represented a significant risk (OR 1.3, 95% CI 1.1–1.4, P< 0.001). Perceived physical demands and relieving factors were not significant (P> 0.05). The multivariable model showed that physical aggravating factors accounted for 16% of the variance (OR 1.3, 95% CI 1.1–1.4).

Conclusions: Beliefs about the work environment/organisation and physical aggravating factors are significant risks for future absence, although when considered together, physical aggravating factors dominate. These results highlight the potential for ergonomic interventions to reduce symptom-aggravating aspects of work to reduce absence.

Introduction: This study examined the cohort of patients selectively screened over a 5 year period with ultrasonography according to our risk factors (positive Ortolani or Barlow manoeuvre, breech presentation, first degree affected relative and talipes equinovarus) for developmental hip dysplasia (DDH). The aims were to evaluate the success of those managed in a Pavlik harness and identify predictive factors for those that failed treatment.

Methods: 1181 patients were selectively screened between 1999 and 2004. Of those, 128 patients (189 hips) were identified as having hip instability. Failure was defined as inability to achieve or maintain hip reduction in a Pavlik harness. A proforma was designed to document patients’ risk factors and ultrasound findings at time of initial dynamic ultrasound scan where the senior radiographer and treating consultant were present. Each hip was classified according to Graf type. Acetabular indices were recorded prior to discharge.

Results: All 128 patients with hip instability were managed in a Pavlik harness. This was abandoned for surgical treatment in 9 patients (10 hips) giving a failure rate of 5.3 % (0.17 per 1000 live births). All those successfully managed had an acetabular index of less than 30 degrees at follow up (6 – 48 months). 7 hips in the series were classified as Graf type IV, of these, 6 went on to fail management in a Pavlik harness. 67% of those that failed were also breech presentation compared to 22% of those managed successfully. There were no complications associated with management in a Pavlik harness. 16 patients born within our region presented after 12 weeks of age with DDH resulting in a late presentation rate of 0.3 per 1000 live births.

Discussion: Our overall rate of selective screening is 14 per 1000 live births with a subsequent treatment rate of 2.3 per 1000 is comparable with other centres. Our rate of failure for DDH in a Pavlik harness 0.17 per 1000 live births is an improvement on any previously published results. Irreducible hips, Graf type IV hips and breech presentation correlated with a high likelihood of treatment failure.

Introduction: The majority of midshaft humeral fractures will achieve a satisfactory outcome with non-operative management. However, internal fixation is occasionally required to assist with rehabilitation, particularly in multiply-injured patients. Although the clinical risks and benefits of the locking plate and humeral nail are well known, there is a paucity of data comparing their mechanical properties.

The aim of this study was to determine the torsional and 4-point bending properties of a midshaft humeral osteotomy reconstructed with either an intramedullary nail or locking plate.

Methods: 19 fresh cadaveric humeri were DEXA scanned to ensure similar BMD. Non-destructive 4-point bending was performed on the intact bone to determine stiffness in the sagittal and coronal planes. Load was applied using an MTS MiniBionix 858 (Mechanical Testing Systems, MN) at a rate of 1 mm/min to a maximum of 450 N.

A transverse midshaft osteotomy was created and a spacer ensured a constant 3-mm gap between the bone ends. Reconstruction was performed with either

Trigen humeral nail (Smith & Nephew, TN) – 10 specimens

Non-destructive 4-point bending was repeated, and then each humerus was embedded in a low-melting point alloy proximally and distally for torsional testing. Torque was applied at 5 deg/min until failure. Maximum torque, maximum angle and stiffness were calculated.

All data were analysed with SPSS for Windows (SPSS Inc., Il) using ANOVA.

Results: One specimen in the locking plate group fractured during plate application and was excluded from the study. Non-destructive bending tests showed no significant difference in stiffness of the intact bones between the two groups.

4-point bending: the bones reconstructed with the intramedullary nail were ~50% as stiff as the intact state in both planes. There was no statistically significant difference in stiffness between the intact bones and those reconstructed with the locking plate.

Torsional testing: the locking plate specimens were 3 times as stiff as the intramedullary nail specimens (P< 0.05) and failed at twice the torque (P< 0.05).

Discussion: Humeral intramedullary nails are reported to have an advantage over plates under axial loading (Chen et al, 2002). However, this study demonstrates that locking plates are superior to intramedullary nails in torsion and four-point bending. Although the clinical situation often dictates the most appropriate management, locking plates should be considered in patients when torsional or four-point bending loads are expected to predominate in the post-operative period.

Introduction: A cosmetic deformity does not always occur after a biceps tenotomy. The anatomical restraints preventing distal excursion of the long head of biceps tendon following tenotomy have not previously been described. This study aims to evaluate the biceps sheath and its potential role as a restraint to distal excursion of the biceps following tenotomy.

Methods: Fifteen fresh cadaveric specimens were dissected free of overlying soft tissues to reveal the rotator cuff, biceps sheath and long head of biceps muscle belly and tendon. Eight specimens were used for gross anatomical analysis. Measurements of the length of the biceps sheath on the humeral (bone) side and tendon side were made using a digital caliper (Mitutoyo, Japan). The long head of biceps tendon was then released from the glenoid labrum and the excursion of the stump relative to the rim of the articular surface measured. The biceps sheaths of two specimens were used for histological analysis.

Seven specimens were used for mechanical analysis. A humeral osteotomy was performed distal to the insertion of pectoralis major, leaving intact the biceps sheath and the muscle belly of long head of biceps. The proximal humerus was attached to a custom-designed jig and the muscle belly of biceps grasped in cryogenic grips. Specimens were loaded on an MTS 858 Bionix mechanical testing machine (MTS Systems, MN) in uniaxial tension at a rate of 1 mm/sec until failure was observed.

Results: The biceps sheath surrounds the long head of biceps tendon and inserts into the bone of the proximal humerus. It is trapezoidal in cross-section, with a mean length of 75.1 mm on the bone side and 49.3 mm on the tendon side. The average excursion of the stump was to within 2.8 mm of the rim of the articular surface.

Histological examination of the biceps sheath revealed membranous tissue consisting of loose soft tissue with fat and blood vessels. Synovial tissue was also identified. The sheath was seen to loosely attach to the biceps tendon, with a more intimate attachment to the periosteum.

The mean force to pull the long head of biceps tendon out of the sheath 102.7 N (range 17.4 N–227.6 N)

Discussion: The biceps sheath is a consistent structure intimately associated with the biceps tendon. It appears to contain blood vessels which provide nutrition to the tendon, similar to the vincula of flexor digitorum pro-fundus. Mechanical testing reveals that a substantial force is sometimes required to pull the biceps tendon from the sheath. This may explain why biceps tenotomy does not routinely result in a “Popeye” biceps.

Background: Information on embryological hip development has been obtained from post mortem examination

. There is less information on normal foetal hip

AIM: To assess the value of MRI of the foetus and neonate to provide information on normal and abnormal hip development.

To establish normal patterns of hip development.

To obtain charts that could be used to detect abnormality earlier.

There are three aspects to this study:

Validation – analysing MRI scans of babies hips prior to post mortem (the gold standard) would verify MRI as a valid tool for such studies.

PATIENT SELECTION: 30 patients for each aspect of this pilot study, 90 in total (3).

For the initial validation process, parents who had consented to post mortem were asked to consider additionally an MR scan of their neonate’s hips, a total of 30 cases.

Method: MR images in axial and coronal planes were obtained using a high resolution T2 weighted sequences (4).

Measurements were made, by two independent observers, of the width and depth of the acetabulum and the radius & diameter of the femoral head, volume and area were calculated. Inter-observer variation was assessed.

Results: The babies ranged in gestation from 17 – 42 weeks

With the exception of the acetabular width each dimension showed little development until week 20 when the line of growth rose exponentially. The acetabular width showed only a slow rate of growth despite the changes seen in the femoral head. Levels of observer agreement were high (ICCs = 0.98) for all but depth (ICCs = 0.86). The measurements for all dimensions were in line with previous post mortem studies.

CONCLUSION: MRI is a valid and acceptable alternative to post mortem in the assessment of hip development eventually allowing early detection of abnormal hip development.

Background: Sickness absence, care seeking and symptoms lasting more than 24 hours have all been used to quantify an episode of low back pain (LBP). These measures do not take into account the transient and fluctuating symptoms that sedentary workers may experience over the course of the day, or from day to day. Some workers may not even describe their symptoms as ‘painful’, perhaps preferring alternative pain adjectives such as ‘discomfort’ or ‘aching’. The importance of these symptoms when sitting at work in relation to the development of persistent symptoms and work loss is unknown.

Methods: A new low back discomfort scale was developed based on a 100mm VAS scale ranging from 0 (no discomfort), through to 100 (severe discomfort). Subjects (n=41) were asked to mark on the scale the intensity of any discomfort, i.e. ache, strain, unpleasant sensation or pain experienced when sitting at work in the past week. Subjects were re-tested after a two week time-lapse, and paired t-tests were used to determine test-retest stability.

Results: The retest response rate was 46%, and there were no statistically significant differences (p > 0.05) between test (28mm), and retest (21mm) mean scores. Reports from subjects suggest that the scale has face validity.

Conclusions: The low back discomfort scale was shown to be valid and reliable, providing a broad measure of reported symptom intensity when sitting at work. This scale will now be used in sedentary work environments alongside biomechanical and psychosocial measures to investigate risk factors for persistent LBP and sickness absence.

Background: Symptom modifying factors (SMFs) are everyday activities or postures that are reported to aggravate or alleviate existing LBP symptoms. In relation to sedentary jobs, workers are known to experience LBP whilst sat at work, and may report that aspects of sitting either aggravate or alleviate their symptoms. These factors appear to have received little attention in the literature, and may help to discriminate workers with different types of LBP, or identify workers likely to take sickness absence due to LBP.

Methods: A new sitting and symptom modifying factors questionnaire (SSMQ) was designed and consisted of 11 items. This questionnaire was distributed to 135 sedentary workers on two occasions with a 2 week time lapse. Principal components analysis (PCA) and Cronbach’s alpha were used to explore the structure and internal consistency of the questionnaire. Paired t-tests were used to determine test-retest stability.

Results: Three factors with eigenvalues > 1 were extracted that explained 62% of the total variance, and each factors items loaded > 0.06. These sub-scales related to aggravating and relieving (movement and posture) factors, and had consistency levels of 0.80, 0.72 and 0.78 respectively. The retest response rate was 46% and there were no statistically significant differences (p > 0.05) between test-retest measures.

Conclusions: Validating the SSMQ has produced an instrument that can be used in sedentary jobs to investigate the influence of symptom modifying factors on LBP symptoms, care seeking and sickness absence due to LBP. This questionnaire will now be used in a prospective study of sedentary call centre workers.

Background: Researchers have measured exposure to sitting using self-reported questionnaires and observational analysis. Such methods are not a reliable measure of daily exposure or sensitive enough to take into account lumbar posture when seated. Recent innovations have produced a fibre-optic goniometer (FOG) that can continuously measure sagittal lumbar posture, although this single sensor is unable to identify if the user is sitting, standing or walking.

Methods: A new system was developed utilising a second FOG attached to the hip. Movement characteristics of the hip and lumbar spine were described and used to develop software to predict activity (sitting, standing, walking). Subsequently 10 participants were asked to wear the FOGs for 8 minutes whilst their behaviour was recorded using a video camera. MPEG video sequences were produced and each activity was coded at a point in time and compared against the 2 FOG software model.

Results: All Participants found the system comfortable to wear. Validation of the software against the MPEG files showed high sensitivity for sitting (90%), standing (98%), and walking (95%). Positive predictive value was high for sitting (93%), standing (89%) and walking (94%). The overall agreement between video analysis and the FOG software was 92%

Conclusions: Developing the FOG has produced a practical system capable of continuously measuring sedentary workers basic activity in terms of sitting standing and walking. This novel tool will now be used in a prospective study of sedentary workers to determine the influence of seated lumbar posture on the development of LBP.