Background: Joint replacements are being performed on ever younger patients at a time when average expectancy of life is continuing to rise. Any reduction in the strength and mass of periprosthetic bone could threaten the longevity of implant by predisposing to loosening and migration of prosthesis, periprosthetic fracture and problems in revision arthroplasty.

Aims & Objectives: This study aims to analyse and compare prospectively the femoral periprosthetic stress-shielding around 4/5th and 1/3rd porous coated cementless femoral stems in patients undergoing unilateral cementless total hip replacement done using DEXA scan by quantifying the changes in bone mineral density around femoral component.

Material & Method: Femoral periprosthetic bone mineral density was measured in the seven Gruen Zones with DEXA scan at 2 weeks, 1 years and 2 years after surgery in 60 patients who had undergone unilateral cementless total hip replacement, of which 30 patients had been implanted with 4/5th porous coated stems and other 30 patients with 1/3rd porous coated stems.

Results: At both one and two years postoperatively, bone loss due to stress-shielding was seen in both stems with maximum loss in zone VII and minimum in zone III, IV, V. The maximum mean percentage bone mineral density loss in 4/5th porous coated stems in zone VII was 16.03% at one year and 22.42% at 2 years as compared to loss of 10.07% and 16.01% in 1/3rd porous coated stems. Increased bone loss was seen in patients who had larger diameter stem (> 13.0 mm) and in patients with low bone mineral density in the unoperated hip.

Conclusion: Bone loss as a result of stress-shielding is more pronounced in 4/5th porous coated stems as compared to 1/3rd porous coated stems.

Ossyfying periarticular lipoma is a very rare entity. Lipomas undergo involutional changes like chondrification, calcification and very rarely ossification. These changes result in altered clinical, radiological and histopathological features leading to diagnostic challenge in differentiation from the soft tissue tumor like synovial sarcoma, liposarcoma and rhabdomyosarcoma.

We present a series of three cases of ossifying lipomas presenting as soft tissue tumor around the knee, shoulder and hip joints. All the tumors revealed calcification and ossification on plain X-rays and on MRI/CT Scans. Clinico-radiological evaluation lead to a similar diagnostic dilemma in our series and a confirmed diagnosis of ossifying lipoma became possible only after histopathology. All the three tumors were excised completely without any recurrence during last 3 1/2 years of follow-up.

We recommend the early imaging by MRI/CT scan with closed core biopsy to exclude the malignant pathology and complete excision of the tumor with early mobilization of the adjacent joint.

Introduction: There has been an introduction of short femoral stems with the aim of conserving bone. We present the short term results of short metaphyseal cement-less stem(Proxima^®, Depuy).

Material and methods: 25 patients in age group (25–40yrs), 15 males,10 females were implanted with a short metaphyseal cementless stem (Proxima^®, Depuy) and cementless acetabular cup. The average follow up was 2.3 years (1.4–2.5 yrs). Clinical evaluation using Harris Hip Score, Radiological evaluation and Bone Mineral Density were evaluated at 2weeks, 6 months, 12 months and yearly thereafter. a new zonal method suitable for short stem was used for radiological evaluation.

Results: The mean Harris Hip score improved from 44 to 95 at final follow up. There was no evidence of any radiolucent lines or osteolysis around the stems. All the stems showed evidence of osseointegration at one year follow up. There was no decrease in bone mineral density around the stems.

Discussion: The Short Metaphyseal cementless femoral stem is a bone conserving as well as bone preserving option for young patients especially in those in whom surface replacement is not an option.

Background: Joint replacements are being performed on ever younger patients at a time when average expectancy of life is continuing to rise. Any reduction in the strength and mass of periprosthetic bone could threaten the longevity of implant by predisposing to loosening and migration of prosthesis, periprosthetic fracture and problems in revision arthroplasty.

Aims & Objectives: This study aims to analyse the femoral periprosthetic stress-shielding following unilateral cementless total hip replacement using DEXA scan by quantifying the changes in bone mineral density around femoral component.

Materials and Methods: Femoral periprosthetic bone mineral density was measured in the seven Gruen Zones with DEXA scan at 2 weeks, 1 year and 2 year after surgery in 60 patients who had undergone unilateral cementless total hip replacement, of which 30 patients had been implanted with 4/5th porous coated CoCr stems and other 30 patients with 1/3rd porous coated titanium alloy stems.

Results: At both one and two years postoperatively, bone loss due to stress-shielding was seen in both stems with maximum loss in zone VII and minimum in zone III, IV, V. The maximum mean percentage bone mineral density loss in 4/5th porous coated CoCr stems in zone VII was 16.03% at one year and 22.42% at 2 years as compared to loss of 10.07% and 16.01% in 1/3rd porous coated Ti alloy stems. Increased bone loss was seen in patients who had larger diameter stem (> 13.0 mm) and in patients with low bone mineral density in the unoperated hip.

Conclusion: Bone loss as a result of stress-shielding is more pronounced in 4/5th porous coated CoCr stems as compared to 1/3rd porous coated titanium alloy stems.

Background: Stress radiography and more recently magnetic resonance imaging have been used to study the integrity of lateral ankle ligaments in chronic symptomatic instability after injury.

Aim: Our aim was to see if magnetic resonance imaging was as good as examination under anaesthesia and stress radiography, for diagnosing injury to the lateral ankle ligaments.

Study Design: Cross-over study.

Methods: Fifty eight patients, 47 men and 11 women, were included in the study. These were athletes or military personnel with symptomatic instability of the ankle after injury. This cohort of patients had MRI scans, stress radiographs and arthroscopic treatment of their ankle. Integrity of the calcaneo-fibular ligament (CFL) was recorded arthroscopically. The sensitivity, specificity, positive and negative predictive value of MRI and stress views, in assessing integrity of the CFL, were compared against the arthroscopic findings which was considered to be the gold standard.

Results: Stress radiography under anaesthesia and MRI has sensitivities of 94% and 47% and specificities of 98% and 83% for diagnosing injury to the CFL, respectively. Stress radiography has a higher accuracy in diagnosing CFL injuries as compared to MRI.

Conclusion: The results of this study casts doubt on the efficacy of MRI in the diagnosis of serious ankle ligament injuries.

Background: Joint replacements are being performed on ever younger patients at a time when average expectancy of life is continuing to rise. Any reduction in the strength and mass of periprosthetic bone could threaten the longevity of implant by predisposing to loosening and migration of prosthesis, periprosthetic fracture and problems in revision arthroplasty.

Aims & Objectives: This study aims to analyse the femoral periprosthetic stress-shielding following unilateral cementless total hip replacement using DEXA scan by quantifying the changes in bone mineral density around femoral component over a period of one year and identify the factors influencing the bone loss.

Material & Method: Femoral periprosthetic bone mineral density was measured in the seven Gruen Zones with DEXA scan at 2 weeks, 3 months and 1 year after surgery in 20 patients who had undergone unilateral cementless total hip replacement, of which 10 patients had been implanted with 4/5^th porous coated CoCr stems and other 10 patients with 1/3^rd porous coated titanium alloy stems.

Results: At both 3 months and one year postoperatively, bone loss due to stress-shielding was seen in both stems with maximum loss in zone VII and minimum in zone III, IV, V. The maximum mean percentage bone mineral density loss in 4/5^th porous coated CoCr stems in zone VII was 16.03% at 3 month and 22.42% at 1 year as compared to loss of 10.07% and 16.01% in 1/3^rd porous coated Ti alloy stems. Increased bone loss was seen in patients who had larger diameter stem (> 13.0 mm) and in patients with low bone mineral density in the unoperated hip.

Conclusion: Bone loss as a result of stress-shielding is more pronounced in 4/5^th porous coated CoCr stems as compared to 1/3^rd porous coated titanium alloy stems.

Introduction: Poor proprioception and imbalance between quadriceps and hamstrings have been suggested as causes for anterior knee pain. The aim of our study was to compare the proprioception of patients with anterior knee pain to a normal population and to compare the activity of quadriceps and hamstrings using electromyography (EMG) in the 2 groups.

Methods: Patients and controls between the ages 11–25 yrs were recruited into the study. The proprioception (stability index) of the patients and controls was tested using the Biodex stability system. This computerised system tests the ability of a person to balance his/her own body on a platform that moves in various directions. Surface EMG was recorded from the quadriceps and hamstrings during this test. EMG was also recorded as the patients and controls stepped onto a 20cm step. EMG activity was normalised to levels elicited during maximal isometric contractions.

Results: 18 patients and 27 controls were recruited.

We found no significant difference between the groups in the EMG intensity of vastus lateralis relative to biceps femoris, or vastus medialis relative to vastus lateralis, during the balance test or during the step up task (Mann Whitney U test all p> 0.05). We did not find any difference in the proprioceptive abilities of the two groups

Conclusion: We found no significant difference between the groups in the intensity of muscle contraction of the hamstrings relative to the quadriceps, i.e. no evidence for an imbalance in the patients. However the temporal relation between the two needs further investigation.

Background & Aim: Recent studies have claimed good results after ACI in athletes. Our aim was to evaluate the early functional outcome and activity level after 2-stage ACI in professional athletes and soldiers.

Methods: Thirteen soldiers and five professional athletes (14 men and 4 women; average age 31 years), with 21 full thickness cartilage defects (ICRS grade-IV) of the knee were treated with 2-stage ACI. Mean interval between injury and surgery was 43.8 months. Average defect size was 6.03 cm² and was located to the MFC in 7 cases, LFC in 7 cases and the femoral trochlea in one case. The functional outcome was evaluated with ICRS form, Tegner activity rating scale and Lysholm score after a mean follow up period of 23.4 (18–32) months.

Results: The ICRS and Lysholm scores were improved from 42.7 and 47.6 pre-operatively to 63.1 and 69.9 respectively. The average Tegner scale was 8.8 pre-injury, 3.7 prior to surgery and 6.4 at the final follow up. Nine patients (50%) underwent second-look arthroscopy for persistent mechanical symptoms. Periosteal flap overgrowth was identified in 6 cases with adequate graft integration while partial failure of the graft was noted in one case and was treated with microfracture.

Conclusions: The early results of ACI in high-performance athletes and professional soldiers are not as good as other studies suggest. Returning to pre-injury performance levels for athletes and military people is by no means assured in the first 24 months after ACI.

Aim: Our aim was to measure plantar foot pressures in normal individuals and to compare them with variations in patients with metatarsalgia.

Methodology: We measured the plantar foot pressures in different parts of the foot in normal subjects of various ages and then compared this with foot pressures of patients with metatarsalgia. For measurement and statistical analysis, the plantar contact of the foot was divided into six anatomical divisions. The foot pressures were measured under the hallux, head of first metatarsal, over heads of second, third and fourth metatarsals, the fifth metatarsal, midfoot and hindfoot. This was measured using the FSCAN insole pedobarograph system (Tekscan, Inc, Boston, MA).

The foot pressures were measured in Kilopascals(Kpa). Independent T-tests was used to compare mean pressure distributions in the six anatomical divisions. We found the mean pressures through the 5th metatarsal head – 217(t=−2.32,p< 0.05) and midfoot 94(t=−3.17, p< 0.05), were significantly higher when compared to pressures in normal subjects (table 1).

Conclusion: We have demonstrated increased pressures transmitted through the outer aspect of the sole of the foot, in patients suffering from metatarsalgia. This can be used further to plan any foot- orthosis or surgery to distribute pressures more evenly across the sole of the foot.

Background: To analyse the effectiveness and complications of Less Invasive Stabilisation System (LISS plate) in the management of peri-prosthetic femoral fractures.

Materials and methods: We present a study of 18 peri-prosthetic femoral fractures around hip arthroplasty (16 females and 2 male patients) treated with LISS plate between September 2001 to February 2005. The average age of the patients was 81.6 years. Twelve patients had significant co-morbidities pre-operatively. All the fractures were classified according to the Vancouver classification for Peri-prosthetic fracture of femur. Ten were classified as type B1, two as type B2 and six as type C. Eleven fractures were around total hip replacement and seven were around hemi-arthroplasty (four cemented and 3 uncemented). Partial weight bearing started early post-operatively. Full weight bearing varied between 5-6 weeks depending on clinical and radiological status. The patients were followed up untill fracture union.

Results: Three patients died during the follow-up period owing to unrelated causes. The average follow up period was 11.7 months. All the remaining fifteen patients had satisfactory fracture union although one patient required further LISS plate following a fall 17 days postoperatively and another one patient developed low grade deep infection with a chronic sinus. It was noted that in one patient, plate had lifted off the bone at the proximal end with no loss of reduction of the fracture. Three patients were noted to have mild to moderate discomfort around the prominent implant. No implant breakage noted.

Conclusions: Even though LISS plate was originally designed for distal femoral fracture treatment, it appears to be very promising device in the treatment of peri-prosthetic femoral fractures (Type B1, Type C and medically unfit patients with Type B2 for stem- revision) with osteoporotic bone in elderly patients. Early mobilization is a key feature. This system involves minimally invasive approach, stable construct without need for primary bone grafting.

Background: The medial patellofemoral ligament (MPFL) is the principle medial stabilizer of the patella. It is damaged after traumatic patella dislocation. We describe a reproducible technique for MPFL reconstruction and our preliminary results at 12 months.

Material-methods: 25 patients (19 men, 6 women; average age 26.9 years-old) with post-traumatic patellar instability underwent MPFL reconstruction at a mean post-injury interval of 22.3 months. Five patients had evidence of generalized laxity, 3 had trochlear dysplasia and 16 (64%) more than two episodes of dislocation. Arthroscopic assessment revealed associated chondral lesions in 88% and marked lateralization. The reconstruction was performed using ipsilateral semitendinosus tendon. With the distal attachment preserved, the proximal end is passed through the medial intermuscular membrane and secured to the medial border of the patella. Clinical pre- and post-operative assessments included IKDC, Tegner, Lysholm and Kujala scores. ICRS documentation recorded the contribution of articular cartilage damage, whereas Merchant views and MRI scans documented the abnormal radiological parameters and the damaged structures of the medial retinaculum respectively.

Results: At a mean follow up period of 12 months (8–18 months) no cases of re-dislocation were recorded. The Tegner and IKDC scores averaged 4.2 and 46.9 pre-injury. Postoperatively they had improved to 7.7 and 86.5. The average postoperative Lyshom- and Kujala scores were 87 and 89 respectively. Re-operation was required in one patient after patellar fracture 8 weeks post reconstruction.

Conclusion: Our preliminary results suggest surgical reconstruction of the MPFL provide a favorable early outcome for the treatment of post-traumatic patellofemoral instability and will form the basis for longer follow up in a larger cohort.

Introduction: The commonest surgical approach for total knee arthroplasty is medial parapatellar approach. This involves splitting the quadriceps tendon, potentially destabilising the extensor mechanism. The midvastus approach involves splitting the vastus medialis muscle instead of entering the quadriceps tendon, therefore, minimising interruption of the extensor mechanism without compromising the exposure of the knee.

Objective: To compare clinical parameters associated with medial parapatellar and midvastus approaches for total knee arthroplasty in the early postoperative period.

Methods and results: We present a prospective observational study of 88 patients undergoing primary total knee arthroplasty using medial parapatellar or midvastus approach (44 in each group). The prosthetic design and physical intervention was standardised in all the patents. The Oxford Knee Score, pain scale, knee flexion, unassisted straight leg raise, standing and walking were compared at 3^rd, 5th and 7^th day postoperatively, then at 6 weeks and at 3 months. The patients and physiotherapist were blinded to the type of approach used. The average age was 67 years (range 42 to 88). There were 49 women and 39 men. The average hospital stay was 7 days (range 2 to 15). There was statistically significant difference in duration of hospital stay, unassisted straight leg raise and standing at 3 days (p=0.001) and pain scale at 5 days, all in favour of midvastus approach. There was no statistically significant difference in Oxford Knee Scores and duration to achieving full flexion and walking. The average duration to achieving straight leg raise for the midvastus group was 5 days and for the medial parapatellar approach group was 8 days

Conclusion: The study shows that total knee arthroplasty performed through the midvastus approach resulted in less postoperative pain, earlier unassisted straight leg raise and ambulation, therefore, shorter hospital stay as compared to medial parapatellar approach. This may be of benefit to the patients due to less discomfort after surgery, and to the healthcare system due to shorter hospital stay for patients.

Aim: 1. To assess the role of the CT scan in management of intra-articular fractures of the calcaneum. 2. Does the scan makes any difference to the management decision, obtained from assessing the plain radiograph?.

Methodology: This study involved 24 patients with intra-articular fracture of the calcaneum who had both a plain radiograph and a CT scan as a part of their assessment. Three consultants who were blinded to the actual management and names of the subjects were independently asked to grade the radiographs and CT scans, as operative or non-operative, on different occasions. The data was matched to the actual management and was subjected to statistical analysis.

Results: The data was non-parametric and related. The SIGN test was used to analyse the agreement between the three observers and if the decisions made in each of the groups were significantly different from the actual management. There was no statistically significant difference, between the management decision from the radiographs or CT and the actual management.

The change in management that the CT scan brought about was also assessed for each of the observers using the McNemars test. The CT scan did not make any significant difference to the decision made based on the plain radiographs, on whether to operate or not.

A Cochran Q test used to assess the variability of the decisions, showed that there was more inter-observer variability in decision making, using the CT based assessment (Q=9.50, p=0.009) as compared to plain radiographs (Q=3.84, p=0.14).

Conclusion: We conclude that, the CT scan should only be requested when a decision is made to operate on the fracture, based on plain radiographs. This may help with pre-operative planning of fracture fixation. It does not have to be obtained as a routine to assess all intra-articular fractures of the calcaneum.

CT- scan as an management tool is being used extensively in managing calcaneal fractures. We set out to see if a CT-scan makes any difference to the management plan as obtained by looking at the plain radiograph. We also looked at the correlation with the actual management.

Methodology: This was a retrospective study involving 24 patients with fracture of the calcaneum. These patients had both a plain radiograph and a CT- scan to help decide on management. The actual management that each of these patients had was documented. Three consultants who were blinded to the actual management and names of the subjects were independently asked to grade the radiographs, as operative or non-operative. They were then similarly, asked to decide on operation or no-operation based on blinded CT- scans. The data obtained from the three observers were compared to the actual management and were subjected to statistical analysis.

Results: As the data was categorical and matched, the Mcnemars test was used to test the association between the management plan obtained from the radiographs and the management plan obtained from the CT scans, for each consultant. They were also compared with the actual management. The statistical analysis showed that there was no statistically significant association between the management decision obtained from the radiographs and the CT san, for all three observers. Radiograph and CT scan based management decisions also did not correlate with the actual management.

Conclusion: The CT scan should only be done when a definite decision is made to operate on a patient, based on plain radiographs. Calcaneal fractures which are decided not to operate, based on X rays, should not have a CT scan as a routine as it provides no valuable additional information.

Introduction Plantar foot pressure measurements using pressure distribution instruments is a standard tool for diagnostic and therapeutic interventions. Foot pressure studies have measured pressure distributions in patients with various conditions such as rheumatoid arthritis, diabetes and obesity . Pressure studies in metatarsalgia and Hallux rigidus, to our knowledge, has not been reported previously. Our aim was to measure plantar foot pressures in normal individuals and to compare them with variations in patients with metatarsalgia and Hallux rigidus. This data may enable us to identify areas of abnormal pressure distributions and thus plan foot-orthosis or surgical intervention.

Materials and Methods This was a case control study. We measured the plantar foot pressures in different parts of the foot in normal subjects of various ages and then compared this with foot pressures of patients with metatarsalgia and hallux rigidus. For measurement and statistical analysis, the plantar contact of the foot was divided into six anatomical divisions. The foot pressures were measured under the hallux, head of first metatarsal, over heads of second, third and fourth metatarsals, the fifth metatarsal, midfoot and hindfoot. This was measured using the FSCAN insole pedobarograph system (Tekscan, Inc, Boston, MA).

Results The foot pressures were measured in Kilopascals(Kpa). Independent T-tests was used to compare mean pressure distributions in the six anatomical divisions. Comparing normal with metatarsalgia, the mean pressures through the 5th metatarsal head 217(t=−2.32,p< 0.05) and midfoot 94(t=−3.17, p< 0.05), were significantly higher when compared to pressures in normal subjects. In patients with hallux rigidus, the mean pressures through the hallux 314 (t=−3.62, p< 0.01) and mid-foot 140 (t=-5.11, p< 0.01), were significantly higher, as compared to pressures in normal subjects.

Discussion Metatarsalgia is a condition that presents with pain under the region of the 2nd to 4th metatarsal heads. Hence, the normal response of the body would be to avoid putting increased pressure through this region, thus causing increased pressures to be transmitted through other parts of the foot. The foot pressures through the hallux and midfoot were higher in patients with hallux rigidus (compared to normal). This results in pressure imbalances and thus may contribute to pain, deformity and abnormal gait. Our study, confirms this, the mean plantar foot pressures were higher under the 5th metatarsal head and the midsole as compared to normal subjects. This could be explained by the tendency to walk on the outer aspect of the sole to avoid the painful area. Thus, any foot orthosis or surgery should aim to redistribute these forces.

Conclusion We have demonstrated increased pressures transmitted through the outer aspect of the sole of the foot, in patients suffering from metatarsalgia. The pressures through the Hallux and midfoot were higher in oatients with hallux rigidus. This information can be used further to plan any foot-orthosis or surgery to distribute pressures more evenly across the sole of the foot.

Objective: Our aim was the record variation in foot pressures through parts of the foot, in normal subjects and compare with foot pressure distribution in patients with conditions of the foot such as symptomatic hallux rigidus and metatarsalgia.

Methodology: This was an observational study. We assessed the foot pressure distributions in 30 normal subjects, using the foot pressure pedobarograph system. The foot pressures were measured through the Hallux, 1st Metatarsal head, 2,3,4th metatarsal heads, 5 metatarsal head, midfoot and hindfoot. Foot pressure in patients with hallux rigidus and metatarsalgia were compared with the pressures in normal subjects, using statistical analysis.

Results: The foot pressures were measured in Kilopascals(Kpa). Independent T test was used to compare pressures. In patients with hallux rigidus, the mean pressures through the hallux 314 (t= −3.62, p< 0.01) and midfoot 140 (t=−5.11, p< 0.01), were significantly higher, as compared to pressures in normal subjects. In patients with metatarsalgia, the mean pressures through the 5th metatarsal head 217 (t=−2.32, p< 0.05) and midfoot 94 (t=−3.17, p< 0.01), was significantly higher when compared to pressures in normal subjects.

Conclusion: The foot pressures through the hallux and midfoot were higher in patients with hallux rigidus (compared to normal). Thus any foot orthosis or surgery should aim to relieve the pressure through these regions. Whereas, foot pressures through 5th metatarsal head and midfoot were higher in patients with metatarsalgia (compared to normal). This reflects the adaptation the foot develops to avoid the painful region and thus any orthosis or surgery should try to spread the foot pressures evenly across the foot.

Aim: This study compares the MRI scan with clinical diagnosis, and looks at the reliability of both these against the gold standard of arthroscopic diagnosis, in disorders of the knee.

Materials and methods: The patients were from the knee specialist unit of a tertiary referral centre seen and operated by the senior author , over a two year period. This is a retrospective study. The total number of patients in this study was 58(n=58) , with ages ranging from 18–63 years. The results were obtained using statistical formulae, which calculated the sensitivity , Specificity , accuracy and the positive and negative predictive values of the MRI scan and that of clinical diagnosis .

Results: The MRI scan was found to be significantly sensitive in diagnosis of medial meniscal lesions, 96% (95% Confidence interval 89–100), it was also found to be significantly specific in diagnosis of lateral meniscal, 90% ( 95% CI, 81–98) and ACL lesions 94% (95% CI,87–100). The MRI scan had poor sensitivity and specificity for articular cartilage lesions.

The sensitivity of clinical diagnosis for medial and lateral meniscus and ACL lesions was found to be less than 90%. Clinical impression was found to be significantly specific for lesions of ACL and the articular cartilage.

The negative predictive value of the MRI scan was found to be significantly high (> 95%), for lesions of the medial and lateral meniscus and the ACL.

Conclusion: The MRI had a poor diagnostic value in diagnosing and quantifying articular cartilage (chondral) lesions. Clinical diagnosis had a lower sensitivity as compared to MRI in diagnosis of medial meniscal lesions but was more specific in diagnosing cruciate and articular cartilage pathology. The reliability of a high negative predictive value for the MRI scan in ruling out medial meniscus, lateral meniscus and ACL lesion was demonstrated. Therefore, a ‘normal’ scan can be used to exclude lesions. thus sparing patients from expensive and unnecessary surgery and also freeing up valuable theatre time.

Purpose of the study: To determine usefulness of skyline x-ray in diagnosis of patellofemoral osteoarthritis.

Materials and Methods: 50 patients scheduled to undergo knee surgery, had standard antero-posterior, lateral and skyline x-rays of their affected knee. At operation, their patellofemoral joints were graded into two groups according to presence or absence of osteoarthritis. Their lateral and skyline x-rays were also graded into the same two groups, according to presence or absence of patellofemoral osteoarthritis. The two x-ray views were then compared individually against operative findings.

Results: The skyline view had sensitivity of 79% (95% confidence intervals (C.I.) 66% to 93%) and specificity of 80% (95% C.I. 62% to 98%). The lateral view had sensitivity of 82% (95% C.I. 69% to 95%) and specificity of 65% (95% C.I. 44% to 86%).

Conclusion: There was no statistically significant difference between the two x-ray views in terms of sensitivity and specificity in the diagnosis of patellofemoral osteoarthritis of the knee joint. Hence, we cannot recommend the skyline view as a routine radiological investigation in all cases of suspected patellofemoral osteoarthritis.

Aim: Assessing Polyethylene wear is very important in following up patients after Total hip replacement (THR) and Livermore method (using callipers) is routinely used by clinicians in calculating this wear. Our aim was to assess if ‘Imagika’, a new computer software programme can accurately assess polyethylene wear(PE-wear). We also compared the computer software with the Livermore method in calculating wear.

Method: We used 15 different THR X rays of patients who had an ABG total hip replacement done. X rays that were included for the calculations were taken at different time intervals following the operation. Wear was calculated on each X ray by 3 clinicians using both the methods, on 3 separate occasions. We compared the Livermore method and the computer software for consistency of measurements and also calculated the inter and intra observer variability for both.

Results: There was a statistically significant difference (at the 5% level) between the measurements taken by the Imagika software and the Livermore method. F(1,88) = 5.38, p< 0.05. There was a statistically significant difference in the inter-observer measurements using the Livermore method. F(2,42) = 4.18, p< 0.05, but there was no significant inter-observer variation using the Imagika computer software. There was no statistically significant difference (at the 5%level) in the intra-observer variability of both groups.

Conclusion: The Imagika computer software proved to be better than the Livermore method in calculating wear with regards to inter-observer bias. There was also a significant difference between measurements taken using both methods. We conclude that the computer software may be a more accurate tool in the assessment of PE-wear in the future.

Schistosomiasis is a common parasitic infestation in Egypt. We describe the case of a 24-year-old Egyptian man who presented with the signs of acute septic arthritis of the hip and in whom biopsy subsequently revealed schistosome ova in the synovium.