Introduction: Measurements taken from digital radiographs and corrected for the labelled scale do not correspond to actual clinical dimensions accurately.

Methods: The routine radiographs taken of 30 hip hemi-arthoplasty patients were used to make measurements in the region of the hip. 15 patients were compared in two hospitals using different digital imaging processing. The images were scaled to 100% (actual size), three blinded measurements were taken of the prosthetic femoral head and the average calculated. These results were compared to the actual size of the implanted prosthesis. Further analysis was carried out to determine true magnification.

Results: A consistent difference was observed between measured dimensions at 100% scale and known actual prosthesis dimensions. It was identified that the magnification factor ranged from 110 to 115% with at average magnification factor of 113%. No significant difference was observed between the two hospital systems.

Discussion: Many factors influence radiographic magnification, including variations in distances from x-ray source to patient and from x-ray source to x-ray plate. Angulation and degree of divergence of the x-ray beam and rotation of a limb also influence the magnification which occurs. Accurate measurements can only be taken from digital x-rays if appropriate calibration is performed.

Introduction: The Ionising Radiations Medical Exposure Regulations Act 2000 has established diagnostic reference levels for radiological examinations, however at present there are no national guidelines available for orthopaedic trauma surgery. There may be a role for the introduction of diagnostic reference levels at a local level therefore we studied patient area dose and screening time for orthopaedic trauma operations performed in the Regional Trauma Centre in Northern Ireland.

Methods: Retrospectively data was retrieved from written radiography records in the Royal Victoria Hospital, during the period of 1st January 2007 to 31st December 2007 for all orthopaedic trauma cases in which an image intensifier was used. The screening time, patient area dose (PAD), details of the operation, patient age, sex, month of the operation and grade of the operating surgeon (trainee or consultant), were recorded.

Results: 1709 cases using image intensifier were reviewed. 137 cases were excluded due to incomplete data. 319 hips were screened for insertion of sliding hip screw, mean screening time was 0.51min with a mean PAD of 145cGycm2. 127 femoral nails were inserted with an average screening time of 1.84min and mean PAD of 310 cGycm2. 166 tibias were screened for application of Ilizarov frame or insertion of tibial nail, average screening time was 3.00min with a mean PAD of 48cGycm2. 129 spinal cases were screened with an average screening time of 0.80mins and mean PAD of 37.9cGycm2. Consultants had lower screening times and mean PADs than trainees with 0.63min versus 1.01min and 65.8cGycm2 versus 70.9cGycm2.

Conclusions: The average screening times and mean PADs compared favourably with local reference guides for image intensifier cases and with other published series. Every trauma unit should have local reference ranges for orthopaedic imaging cases and regular audit should be carried out to assess compliance with these ranges.

Aim: To investigate and compare the effects of two types of LCS total knee arthroplasty on joint proprioception and range of motion.

Methods: 47 patients were randomised to receive either a LCS AP glide or Rotating platform prosthesis. Clinical scores (Oxford knee score, American knee society score, EuroQol), range of motion and proprioception were assessed prior to and at 3,6, and 12 months after the operation. Proprioception was assessed in terms of absolute error angle (mean difference between the target angle and the response angle). Knee angles were measured in degrees using an electromagnetic tracking device, Polhemus 3Space Fastrak that detected positions of sensors placed on the test limb. Student’s t-test was used to compare the mean of two groups (with a level of significance of p < 0.05).

Results: Both groups were comparable in terms of pre-operative range of motion, oxford knee score, American knee society score, EuroQol score and proprioception. There was statistically significant improvement in the Oxford knee score, AKSS and EuroQol score in both groups (p< 0.001), but there was no difference between the groups with respect to these parameters. There was improvement in the proprioception (reduction in absolute error angle) in both groups though this was not significant statistically (p> 0.05).

Conclusions: We did not find significant difference between AP glide and RP LCS knee arthroplasty in terms of improvement in proprioception and range of motion.

Introduction: Elective Orthopaedics has been targeted by the department of health in the U.K. as a maximum six-month waiting time for operations could not be met. National Orthopaedic project was initiated as a consequence and Independent Sector Treatment Centres (ISTC) and well established private hospitals were utilised to treat NHS long wait patients.

Materials and Methods: We audited the primary total hip replacements performed in our hospital in 1998 and 2003 to compare the differences in the patient characteristics in particular age, length of stay and ASA grade.

Results: The number of hip replacements increased to 308 in year 2003 from 194 in year 1998. Whilst, the number of ASA I patients were the same, the ASA II. III, IV increased by 40%, 260%, 266% respectively. The average length of stay decreased from 14.3 to 11.9 days which was statistically significant, in spite of increased numbers of ASA II – IV patients.

Discussion: The NHS hospitals are treating increasing number of patients who have a higher anaesthetic risk and are likely to stay longer in the hospital in the post-operative period. The case mix for primary total hip replacements in large tertiary referral hospitals have changed due to altered patient flow due to cherry picking of NHS waiting lists by the ISTC. NHS hospitals should be appropriately remunerated for dealing with complex cases and for managing complications referred by ISTC hospitals. In fact, the National joint registry’s 2^nd annual report confirms that 40% of primary total hip replacements operated in ISTC’s were ASA I while only 25% of primary total hip replacements operated in NHS hospitals were ASA I. None of the ISTC’s performed complex primary THRs.

When deciding on treatment for displaced mid-shaft clavicle fractures, patients often inquire if repair of (potential) nonunion results in outcome similar to acute fixation. We used objective muscle strength testing and patient-oriented outcome measures to examine this question. Late reconstruction of nonunion following displaced mid-shaft fractures of the clavicle results in restoration of objective muscle strength similar to that seen with immediate fixation. However, there was a significant loss in muscle endurance as well as a trend towards a decrease in outcome scores (DASH, Constant) following late reconstruction. This information is useful in surgical decision making and in counseling patients.

Using objectively measured strength and patient-oriented health-status instruments, we sought to determine if delay in repair of displaced, mid-shaft clavicle fractures negatively affected shoulder strength or outcome.

Late reconstruction of clavicle nonunion results in restoration of objective muscle strength similar to that seen with immediate fracture fixation, but there was a significant loss in muscle endurance as well as a trend towards a decrease in outcome scores (DASH, Constant).

All patients had sustained completely displaced, closed, isolated mid-shaft clavicle fractures. Fifteen patients had immediate plate fixation (mean 0.6 months post-fracture) and fifteen had plate fixation for non-union (mean fifty-eight months post-fracture). Objective muscle strength testing on the BTE was done a mean of twenty-nine months post-fixation (normal contralateral limb as control). There were no significant differences between acute fixation and delayed reconstruction groups with regards to strength of shoulder flexion (acute = 92.4%, delayed = 89.4%, p=0.56), shoulder abduction (acute = 98.8%, delayed = 96.7, p=0.75), external rotation (acute = 98.4%, delayed = 91.9%, p=0.29), or internal rotation (acute = 96.3%, delayed = 97.4%, p=0.87). However, there was a trend for improved Constant scores (acute = 94.5, delayed = 90, p=0.09) and the DASH scores (acute = 3.4, delayed = 9.0, p=0.09) in the acute fixation group. We found a significant decrease in muscle endurance with regards to shoulder flexion (acute = 107.0%, delayed = 71.1%, p=0.007) and a trend towards weaker shoulder abduction (acute = 103.1%, delayed = 88.7 %).

Funding: Mr. Potter was supported by a St. Michael’s Hospital Summer Student Scholarship

Aim: To present and highlight a remote complication following deep x-ray radiotherapy to Ilium.

Background: Radiotherapy is one the options to treat malignancy. Surrounding normal tissue can be affected by super-imposed infection, radiation-induced tumors, and other complications of radiation therapy. Timing of radiation changes varies in the different organs. Acute radiation pneumonitis is generally seen approximately 2 months after completion of radiotherapy, but radiation pericarditis not until 6–9 months after therapy. Radiation-induced sarcomas do not develop on average until 10–15 years after radiation therapy.

Case report: A 39-year old presented to an oral surgeon 29 years ago with a submandibular swelling that was gradually increasing in size. Excision biopsy revealed Follicular, Large cell, Non-Hogdkin’s Lymphoma. Lymphogram showed positive nodes in pelvic and para-aoric regions. She was treated with chemotherapy initially. She developed left SI joint pain 2 years later and was treated with radiotherapy. The lymphoma later became chemotherapy resistant and the patient was treated with whole body irradiation. She was in remission since 26 years. She started having discomfort in the left hip region far past 5 years and was reviewed. A recent MRI scan revealed avascular necrosis of the femoral head with little collapse. Changes in the ilium and muscle wasting around the left iliac wing were noted, which were consistent with post radiation osteonecrosis.

This lady noticed a recent change in the gait and examination revealed positive trendelenberg test and a lurching gait. Latest radiographs have shown a fracture of the left iliac crest. The patient did not request any surgical intervention and was reassured with explanation.

Conclusion: Post radiation osteonecrosis can cause complications as late as 26 years following deep x-ray radiotherapy.

Aim: To investigate and compare the effects of two types of LCS total knee arthroplasty AP glide {(posterior cruciate is retained and the mobile bearing allows anteroposterior and well as rotational movement) and RP (in which posterior cruciate is sacrificed and the mobile bearing allows only rotational movement)} on joint proprioception and range of motion.

Methods: 30 patients scheduled to undergo mobile bearing total knee arthroplasty were randomised to receive either a LCS AP glide or Rotating platform prosthesis. Clinical scores (Oxford knee score, American knee society score (AKSS), EuroQol), range of motion and proprioception were assessed prior to and at three and six months after the operation. Proprioception was assessed in terms of absolute error angle (mean difference between the target angle and the response angle). Student’s t-test was used to compare the mean of two groups (with a level of significance of p < 0.05).

Results: Both groups were comparable in terms of pre-operative range of motion, oxford knee score, American knee society score, EuroQol score and proprioception. At 6 months there was significant improvement in the Oxford knee score, AKSS and EuroQol score in both groups (p< 0.001), but no difference was noted between the two groups with respect to these parameters. There was improvement in the proprioception (reduction in absolute error angle) in both groups though this was not significant statistically (p> 0.05). The mean active non-weight-bearing range of motion improved in both groups {AP glide group, (p< 0.05) and RP group, (p> 0.05)}

Conclusions: We did not find significant difference between AP glide and RP LCS knee arthroplasty in terms of improvement in proprioception and range of motion.

Introduction and Aims: Autologous chondrocyte implantation (ACI) is emerging as a leading technique for the treatment of articular cartilage defects. However, there exists some debate regarding which ACI technique is best able to regenerate hyaline cartilage. To this end, the development of a non-invasive technique enabling the examination of microstructure after ACI is essential.

Method: In this study, we have developed a novel 2D Laser Scanning Confocal Arthroscope (LSCA) in the assessment of articular cartilage and examined the microstructure of knee articular cartilage from rabbits and patients with total knee arthroplasty. The LSCA system consists of the LSA handheld probe, a Launch and Detection Unit (LDU) with a built in 488nm–514nm Krypton Argon Laser and Master Control unit (MCU). Human and rabbit knee articular cartilage stained with Fluoroscein (5g/L) and Acriflavine (0.5g/L) were used to examine the microstructure of cartilage by LSCA.

Results: By LSCA we have generated optical histology images of normal human and rabbit articular cartilage from the femoral condyle. Optical histology of normal articular cartilage tissue reveals typically smooth surface texture with relatively homogenous sub-surface distribution of viable chondrocyte cells. The general orientation of collagen fibres is occasionally visible in surface images. Optical histology of arthritic cartilage of humans showed clusters of round-shaped chondrocytes mixed with spindle-shaped cells. Surface cracking typically indicative of tissue damage is also evident by LSCA observation. Examination of rabbit knee six weeks after ACI showed high density of chondrocytes and homogeneous matrix on the site of the defect.

Conclusion: In short, we have shown the efficacy of LSCA in the non-destructive assessment of articular cartilage in vivo. Further study is required to evaluate the clinical significance of optical histology of LSCA.

Introduction and Aims: Conventional histology requires the traumatic removal of tissue from its native environment. This is not only a destructive process but also leads to tissue preparation artefact. We report on a novel arthroscopic instrument, the laser scanning confocal arthroscope (LSCA), which can image tissues of the knee at depth without the need for a damaging tissue biopsy.

Method: The new confocal arthroscope contains 4.4mm diameter with a 90-degree lens. Using three knee joints from two adult Merino sheep we imaged muscle, cartilage, ligament, tendon, synovium, meniscus and loose connective tissue. The knees were separately injected with three fluorophores (Acridine Orange, Acriflavine/Calcein-AM or Fluorescein) prior to imaging. Using a medial para-patellar incision, the contents of the knee were exposed and the confocal arthroscope was held directly on the tissue of interest. A second operator captured the images on a computer.

Results: We were able to demonstrate the common histological features of normal sheep articular cartilage, meniscus, synovium, ligament, tendon and muscle. Tissues were imaged to depths of 200 microns. Articular cartilage was characterised by a layer of dense superficial cells surrounded by extracellular matrix. There was no visible orderly arrangement of cells in this layer. Meniscus was characterised by closely packed circumferential collagen fibres. Synovium demonstrated a dense collection of cells in a thin membrane, typical of this secretory tissue. Ligament and tendon were characterised by bundles of parallel collagen fibres interspersed by scattered cells. Muscle revealed a typical arrangement of muscle fibres surrounded by a loose connective tissue and separated by capillaries and nerves. Eccentric nuclei were seen, however striations were beyond the imaging resolution of the arthroscope.

Conclusion: This study demonstrates the use of a novel arthroscopic instrument for the non-destructive examination of the components of the sheep knee joint. We foresee that the laser scanning confocal arthroscope will have future application in the assessment of cartilage grafting techniques and arthritis modifying drugs.

Objective- To review the 10-year results of 269, cemented total hip arthroplasties performed using matte surface finish Harvard femoral stem that is almost similar to Charnley femoral stem.

Design- Retrospective cross sectional survivorship study.

Patients and Methods- We retrospectively reviewed the results of 269 cemented total hip arthroplasties performed using Harvard femoral stem in 257 patients (M:F, 93:164. Mean age 71.2 years) between 1990–1994. We also reviewed a group of 51 patients who had hip arthroplasty performed on the contralateral side using cemented Charnley femoral stem. Radiographs were reviewed to evaluate following parameters: type of osteoarthritis, cement mantle thickness, alignment of the components, presence of aseptic loosening and radiolucent lines. Kaplan-Meier survival analysis was performed to calculate the survival of Harvard and Charnley femoral stem using various end points. Cox proportional-hazard analysis was performed to evaluate the impact of various radiological parameters on the prosthesis survival.

Results- Out of the 248 eligible patients (260 hips), 6 patients (7 hips) were lost to follow up and 67 patients were dead at the time of the study. 36 hips (35 patients) underwent revision surgery for aseptic failure (Median duration: 60 months, range: 12–125 months) and 11 hips were revised for septic failure (Median duration: 24 months, range: 10–53 months) from the index procedure. Femoral component was revised in all patients whereas acetabular component was revised in 27 patients. 10 year survival for the femoral and acetabular components using aseptic loosening (with and without revision surgery) as an end point was 77.5% (71.5%-83.5%) and 91.1% (87.2%-95%) respectively. Cox regression analysis did not reveal statistically significant (p> 0.05) impact of various radiological parameters on survival rate.

The 10 year survival in the bilateral hip arthroplasty group for the Charnley femoral component (Median follow up 138 months) and Harvard femoral component (Median follow up 120 months) using aseptic loosening as an end point was 95.2% (92.4%-98%) and 77.2% (69.2%-85.2%) respectively.

Conclusion- Our results suggest that the matte surface finish femoral component has less satisfactory long-term survival rate compared to smooth surface femoral stem with similar geometry.

Objective- To evaluate three femoral cement pressurization techniques in a laboratory setting.

Design- Observational study using a plastic femur (sawbone) model.

Materials and Methods- 12 femoral bone models were cemented and pressurized using three different cement pressurization techniques (standard technique, pressuriser in situ technique, and thumb pressurisation technique). Four sets of observations were taken for each technique. Intramedullary pressure readings were obtained using proximal and distal pressure monitoring transducers. The peak pressure and the time for which the pressure was above a particular cut off level (5 KPa and 100 KPa) were compared.

Results- There were significant variations between the peak pressure and the duration for which the pressure was above 100 KPa. The pressuriser in situ technique yielded significantly (p< 0.001) higher peak pressure both proximally (397.5 ± 40.2 KPa) and distally (597.3 ± 102.4). The standard technique produced the optimum pressure of 100 KPa for significantly (p< 0.001) longer duration proximally and distally (66.8 ± 29.5 and 45.2 ± 15.5 seconds respectively) compared to the other two techniques (less than 5 and 17 seconds for thumb pressurisation technique and pressuriser in situ technique respectively, both proximally and distally). There were no significant statistical differences between the three methods for the time for which the cement pressure was higher than 5 KPa.

Conclusion- Although the pressuriser in situ technique produced highest peak pressure, the standard technique produced optimum pressure for longer duration. The standard technique seems to be adequate to achieve optimum pressurization during femoral cementing without increased risk of embolisation.

Introduction: Peri-acetabular rotational osteotomy is recognized as the non-arthroplastic treatment for Developmental Dysplasia of the Hip (DDH). This procedure has increased in popularity during the last decade. It aims to restore the acetabular cover over the femoral head and thus delay secondary osteoarthritic changes in the hip.

Materials and methods: We reviewed 16 patients who underwent peri-acetabular rotational surgery at our hospital. The indication for surgery was DDH in all cases. Reinert’s approach was used for surgical exposure. Two patients underwent a valgus femoral osteotomy at the same time. Mean age was 40 years (range 15–49). The mean follow-up was 46.5 months (range 4–108). The results of the surgery were assessed with radiological indices and a patient satisfaction survey. The radiological indices recorded were Wiberg’s angle, acetabular inclination angle, femoral head extrusion index and Tonnis osteoarthritis grading.

Results: The intervention failed to benefit two patients who subsequently required a total hip arthroplasty. Both patients had Tonnis grade 3 osteoarthritis. One patient developed a necrotic skin flap requiring skin grafting. The mean pre-operative Wiberg’s angle was 11 degrees (range −7 to 25) which was corrected to 35 degrees (range 17 to 58). Mean pre-operative acetabular index was 25 degrees (range 14 to 40) which was corrected to 11 degrees (range of 2 to 21). Mean pre-operative femoral head extrusion index was 37 degrees (range 18–50) which was reduced to 14 degrees (range 0–32). In all but the two patients in whom the surgery had failed, patients reported reduction in hip pain.

Conclusions: Peri-acetabular rotational osteotomy is a challenging but worthwhile procedure for young patients with DDH. The early results from the procedure are encouraging providing patient selection is appropriate. We would like to initiate a debate to identify the ideal patient for this procedure.

Clinical use of glucocorticoids engenders deleterious changes in bone fragility and initiates apoptosis in osteoblasts and osteocytes. The pathways leading to corticosteroid-induced death in bone remain unclear. Similarly little is known about the effects of ‘bone sparing’ bisphosphonates on osteocytes in vivo. We investigated the effects of bisphosphonates (BPs) on dexamethasone (Dex)-induced apoptosis in the murine osteocyte cell line, MLO-Y4 and studied the putative pathways involved by intervention with inhibitors of signalling molecules, such as p42/44 MAPK and protein kinase A (PKA). Cells were preincubated with N- & non N-containing BPs and/or inhibitors before insult with Dex or H₂O₂ for 5 hrs. Apoptotic morphology was revealed by acridine orange staining. Activation of p42/44 was identified using Western blotting and in situ immunocytochemistry in the presence or absence of serum.

Both N- & non N-containing BPs were shown to protect against cell death. The addition of inhibitors of p42/44 and PKA blocked the action of Dex. H₂O₂-induced apoptosis was not blocked by BPs or by any of the inhibitors. Dex appeared to activate p42/44 only in serum supplemented cultures. These data suggest that glucocorticoid but not oxidant-induced osteocyte apoptosis involves activation of p42/44 and that bisphosphonate engendered cell rescue is brought about by inhibition of these MAPK’s. Studies using truncated BPs that lack anti-resorptive activity, and therefore do not interrupt bone remodelling showed that these BPs were also able to protect osteocytes from glucocorticoid-induced death. The ability of bisphosphonates to influence MAPK activation and cell death in the osteocyte opens up exciting possibilities for pharmaceutical intervention during age and steroid hormone related osteocyte loss.

Residual pain after total hip due to a number of causes both local to and replacement may be distant from the hip. We describe pain related to the psoas muscle after total hip replacement in nine patients. All presented with characteristic symptoms. We describe the key features and management. Gratifying results were achieved with treatment. This diagnosis should be considered when assessing patients with pain after total hip replacement.

We compared the mechanical properties of carbon fibre composite bone plates with those of stainless steel and titanium. The composite plates have less stiffness with good fatigue properties. Tissue culture and small animal implantation confirmed the biocompatibility of the material. We also present a preliminary report on the use of the carbon fibre composite plates in 40 forearm fractures. All fractures united, 67% of them showing radiological remodelling within six months. There were no refractures or mechanical failures, but five fractures showed an unexpected reaction; this is discussed.

Ten epiphyses in seven children underwent fixed-rate distraction of 0.25 mm twice daily in an attempt to achieve percutaneous leg lengthening by chondrodiatasis. The forces generated across the growth plate were recorded by means of strain gauges incorporated into the distractors. All epiphyses fractured before 33 days of lengthening. An average gain of 6.75 cm was achieved. Epiphyseal distraction at the lower femur produced many complications, but at the upper tibial epiphysis planned lengthening was achieved, with excellent bone production and few complications.

Shelf operations performed on 24 patients (27 hips) for late presentation of congenital hip dysplasia were evaluated. The mean age at operation was 14 years 9 months and the mean follow-up 16 years 8 months. Two-thirds of the hips had good clinical results at follow-up. Patients operated on under the age of 20 years and with little or no radiological evidence of degenerative joint changes had the highest likelihood of success. The shelf operation was found to provide good cover of the femoral head and, should failure occur, also provides adequate superior support for the seating of an acetabular prosthesis.