Aims

To compare the efficacy of decompression alone (DA) with i) decompression and fusion (DF) and ii) interspinous process device (IPD) in the treatment of lumbar stenosis with degenerative spondylolisthesis. Outcomes of interest were both patient-reported measures of postoperative pain and function, as well as the perioperative measures of blood loss, operation duration, hospital stay, and reoperation.

Purpose

To evaluate efficacy of blood conservation strategies on transfusion requirements in adult scoliosis surgery and establish a protocol for cross matching.

Background and Objective

Patients undergoing hip fracture surgery have a high peri-operative mortality rate. We performed a retrospective study to ascertain if there is any relation between postoperative haemoglobin (Hb) decrease and cardiac related events following the surgery.

We audited all patients who underwent Foot and Ankle surgery at the University Hospital of Wales over one financial year (April 2007 – March 2008).

Patients were identified from the hospital OPCS-4 coding system and all scheduled and unscheduled visits to hospital investigated. Both trauma and elective patients were included. Patients were followed up for a mean period of 9 months (Range 1–14 months) following surgery.

The records for 1052 patients were evaluated. Of these, 77% were elective cases and 23% were trauma related. Overall about 10 % of our foot and ankle patients (100/1052) either attended the A& E Department or had an unplanned clinic visit at some stage of their follow up. Three quarters of these patients were admitted to hospital (median stay 1 day, range 1–51 days).

Twenty five patients (24 A& E; 1 medical) simply re-attended, but were not admitted. The majority of these (58%) had plaster-related problems (8\24) or superficial wound infections (6/24). The remaining patients presented with pain around the operated area, and were discharged after investigation. One patient presented to the physicians 44 days after excision of a Morton’s neuroma with a DVT.

Seventy five patients (7%) were re-admitted to hospital. Two were admitted under the physicians: one with a pulmonary embolus (30 days post ORIF ankle) and one following a cardiac arrest (20 days post ORIF ankle). Out of the remainder 34 patients had planned removal of metalwork, 9 patients had metalwork removed because of infection and 21 patients had soft-tissue infection requiring antibiotics or debridement. Overall, 9 patients underwent revision surgery (0.85%).

The overall infection and thromboembolic rate was 3.42 %(6 A& E + 30 T& O/1052) and 0.28% (1A& E + 2 medical/1052) respectively.

Introduction: Ankle fractures are the most common fracture presenting to any trauma unit in the country with an incidence of 100 per 100,000 in a population. The management and the outcome will very well depend on the mechanism of the injury but there is a window of opportunity of atleast 24hr before the swelling sets in making it technically difficult to operate and hence lengthening the hospital stay with a substantial financial cost. In times where the public health fundings are set to be rolled back and Department of Health been asked to contribute £2.3bn to the Treasury’s £5bn of public spending cuts in2010/1, health economics becomes a vital thread in consideration of treatment planning.

Aim: The study was aimed at determining the delay in definitive fixation of the ankle fractures from the time of presentation to the hospital and the reasons entailing the delay with a resultant economic negative resonance of it on the hospital budget spreadsheets and for the patient.

Method: A retrospective review of all ankle fracture patients operated during Sept 07 to Aug 08 in this hospital was performed. Electronic records were evaluated to identify the waiting times for the surgery and the reasons thereof. Calculations were performed based upon the days lost and calculated against the national minimum wage of £5.73 an hour for adults (workers aged 22 and over) and £4.77 an hour for workers aged 18 to 21 inclusive (often known as the developmental rate). Cost to the trust because of the extra stay was calculated as well.

Results: Total number of patients operated for ankle fracture during the study period was 159. The mean waiting time for surgery was 4.9 days (range 1 to 7.8 days). The mean duration of in-hospital stay for the procedure was 12 days. The commonest cause for the delay of surgery was soft tissue swelling (50%). The total number of patient days lost while waiting for selling to recede was 779.1. Based on the minimum wages considering 8 hours of a working day, the total economic loss to the GDP was approximately £35713.9. With the average cost of hospital stay per day being £ 365 patient the total expenditure to the trust for waiting for the ankle selling to recede was 1788 per patient.

Conclusion: Considering the current economic climate, which is set to affect the spending on the health care, its over time that economic consideration is given while considering the promptness of the action with NCEPOD also suggesting that operatic can be done at night if resources available. With European working time directive in play from august 2009 and open reduction and internal fixation considered a index operation it is possible to operate timely by a fresh surgical team.

We aimed to evaluate the effects of implementing blood conservation strategies on transfusion requirements in adult patients undergoing scoliosis correction surgery. We retrospectively studied 50 consecutive adult patients who underwent scoliosis correction surgery (anterior, posterior or combined) between 2003 and 2007. All patients had a standard transfusion protocol. Age, BMI, pre and post operative haemoglobin, levels fused, duration of surgery, hospital stay, anti-fibrinolytics used and blood transfused was noted.

50 patients with mean age 24.6 years and mean BMI 21.9 kg/m2 were studied. 14 patients had anterior surgery, 19 patients had posterior surgery and 17 had combined anterior and posterior procedures. Mean number of levels fused was 9.5 (6–15) and mean duration of surgery was 284.6 minutes (135–550 minutes). Antifibrinolytics were used in 31 patients (62%), Aprotinin in 21(42%) and Tranexamic acid in 10 (20%). Mean blood loss in patients who received anti fibrinolytics was 530mls while mean blood loss in the other patients was 672mls. (p< 0.05). Blood transfusion was not required in any of the patients undergoing anterior correction only while 7 patients (41%) undergoing anterior and posterior correction and 3 patients (15.8%) undergoing posterior correction only required blood transfusion. Mean volume of cell saved blood re-transfused was 693.8 mls and mean hospital stay was 9.2 days. Mean pre-op haemoglobin was 13.2 g/dl (10.4–17.4) and mean post-op haemoglobin was 10.7 g/dl (7.7–15). 4 patients (8%) required intra and post-operative blood transfusion while 6 patients (12%) required blood transfusion postoperatively.

In conclusion, the use of anti-fibrinolytics like Aprotinin and Tranexamic acid reduces blood loss in scoliosis surgery. In the current scenario, with Aprotinin no longer available for use, our study would recommend the use of Tranexamic acid alongwith other blood conservation measures. In our unit we do not have blood cross matched for anterior surgery alone.

Sacroiliac joint (SIJ) is a diarthrodial joint and can often be a source of chronic low back pain complex. We present a percutaneous technique for SIJ fusion and the functional and radiological outcome following arthrodesis with HMA (Hollow modular anchorage; Aesculap Ltd, Tuttlingen) screws.

Fifteen consecutive patients operated for SIJ fusion between Sep 2004 and Aug 2007 were included in the study. The diagnosis was confirmed with MRI and diagnostic injections. Pre-operative and post-operative functional evaluation was performed using SF-36 questionnaire and Majeed’s scoring system. Postoperative radiological evaluation was performed using plain radiographs. The HMA screws packed with bone substitute were implanted percutaneous under fluoroscopic guidance.

The study group included 11 females and 4 males with a mean age of 48.7 years. Mean follow-up was 14 months. Mean SF-36 scores improved from 37 to 80 for physical function and from 53 to 86 for general health. The differences were statistically significant (Wilcoxon signed rank test; p < 0.05). Majeed’s score improved from mean 37 preoperative to mean 79 postoperative. The difference was statistically significant (student t test, p< 0.05). 13 had good to excellent results. The remaining 2 patients had improvement in SF-36 from mean 29 to 48. Persisting pain was potentially due to coexisting lumbar pathology. Intra-operative blood was minimal and there were no post-operative or radiological complications.

Percutaneous HMA screws are a satisfactory way to achieve sacroiliac stabilisation.

Objectives: To ascertain the frequency and causes of both re-admissions and re-visits (i.e. those not requiring overnight stay) to the hospital following primary and revision TKRs.

Methods: All TKRs performed between April 2007 and March 2008 were included in the study. Mean follow-up period was 9 months (range 3–15 months). Patient data was accessed via computerized patient information systems giving access to the details of inpatient admissions, A& E attendances, laboratory results, radiology reports and clinic letters. Pattern of re-hospitalisation with regards to the cause and time period post-surgery was recorded as well.

Results: Total number of primary TKRs performed in the year was 839 and the re-admission and re-visit rates were 8.22% and 4.17% respectively. The overall re-hospitalisation rate was 12.4%. Most common causes for readmission were pain/stiffness requiring MUA (1.67%) and superficial infections (1.55%). Majority of the revisits were for continuing joint pain (1.67%) and suspected DVT.

Total number of revision TKRs was 136 with a readmission and re-visit rate of 9.7% and 1.49% respectively. The total re-hospitalisation rate was 11.19%. Deep Infections were a prominent cause of readmission (4.4%).

Discussion: Around half (49.5%) of re-hospitalisations were seen in an Orthopaedic setting, the remainder presented to A& E (19.23%), Medical Assessment Units (16.35%) or General Medical Wards (7.7%). Following a primary TKR DVT/PE rates were less than 1% (0.83%). A vast majority (48.6%) of all re-admissions however, occurred within 28 days of discharge. The tradition of seeing patients for the first time in clinic postoperatively after 6–12 weeks may not be appropriate if the majority of re-admissions occur within 28 days.

Conclusion: Idiopathic joint pain and early infections are a major cause of re-hospitalisation. Re-scheduling the first follow-up appointment within the first month after a joint replacement can decrease the overall re-hospitalisation rates and also decrease the impact of these patients on other departments.

Introduction: Physical challenges and a long term treatment for Perthes disease can affect patients’ behaviour in their adolescence. We carried out a study to assess the long term psychosocial development of children treated non-operatively using abduction cast and brace.

Methodology: 104 patients treated for Perthes disease between 1992 and 2001 were recruited for a retrospective study. Besides clinical review, patients and their main carers were asked to fill in Strengths and Difficulties Questionnaires (SDQ). SDQ included scores for total difficulties, emotional symptoms, conduct problems, hyperactivity, peer problems, social behaviour and total impact. 70 controls, matched for age and sex, attending the clinics for other unrelated pathology were requested to fill in the same questionnaires along with their main carers.

Results: Data from 91 patients was available for assessment. Age at diagnosis was 1.9 to 7.3 years (median 3.9 years). Follow-up duration was 5.6 to 15.1 years (median 8.7 years). The age of subjects at final follow up was 8.9 to 20.4 years (median 15.3 years). The mean duration of treatment in abduction cast or brace was 2.4 years.

57 controls and 69 subjects were found to be low risk for emotional disorder (p> 0.05).

Similarly 58 control and 74 subjects were predicted to be low risk for behavioural disorder. 16 controls and 18 subjects had medium or high risk for hyperactivity or concentration disorder (p> 0.05; student t test). There was no significant difference between the self report and parent questionnaires for difficulties or their impact.

Conclusion: Perthes disease and the resultant restricted physical activities in early childhood does not affect the emotional and mental well being of patients in a long term.

Introduction: Inaccuracies in kinematic data recording due to skin movement artefact are inherent with motion analysis. Image registration techniques have been used extensively to measure joint kinematics more accurately. The aim of this study was to assess the feasibility of using MRI for creating 3D models and to quantify errors in data collection methods by comparing kinematics computed from motion analysis and image registration.

Methodology : 5 healthy and 5 TKR knees were examined for a step up/down task using dynamic fluoroscopy and motion capture. MRI scans of the knee, femur and tibia were performed on the healthy subjects and were subsequently segmented using ScanIP(Simpleware) to produce 3D bone models. Registration of the models produced from fine and coarse scan data was used to produce bony axes for the femoral and tibial models. Tibial and femoral component CAD models were obtained for the TKR patients. The 3D knee solid models and the TKR CAD models were then registered to a series of frames from the 2D fluoroscopic image data (Figure 1) obtained for the 10 subjects, using KneeTrack(S. Banks, Florida) to produce kinematic waveforms. The same subjects were also recorded whilst performing the same action, using a Qualisys (Sweden) motion capture system with a pointer and marker cluster-based technique developed to quantify the knee kinematics.

Results: The motion analysis method measured significantly larger frontal and transverse knee rotations and significantly larger translations than the image registration method.

Conclusion: The study demonstrated that MRI, rather than CT scan, can be used as a non-invasive tool for developing segmented 3D bone models, thus avoiding highly invasive CT scanning on healthy volunteers. It describes an application of combining fine and coarse scan models to establish anatomical or mechanical axes within the bones for use with kinematic modeling software. It also demonstrates a method to investigate errors associated with measuring knee kinematics.

Introduction: The Taylor Spatial Frame (TSFTM, Smith & Nephew, Memphis) has gained international recognition for the fixation of complex long bone fractures and deformity correction. It’s application with transverse wires can be difficult in some anatomic regions, and fixation of frames with half pins is gaining clinical popularity. Half-pins cause minimal transfixion of the surrounding soft tissues and can be inserted into anatomically safe areas.

Aims: This study aimed to compare the stiffness characteristics of a TSF frame fixed with transverse wires to fixation with half pins.

Materials and methods: Experiments were carried out in the biomechanics laboratory at Cardiff university. All mechanical testing was performed with a servo-hydraulic test frame (MTS-858 Mini Bionix II®, MTS Corp., Minneapolis). Custom built mounts were used to attach the bone rigidly to one end of the machine and TSF ring to the other. Rings were fixed with 1.8mm transverse wires or hydroxyapatite coated 6.5mm half pins with 45°, 60°, 75° and 90° divergence angles. Bone was loaded with axial load to 400N and torque to 20Nm. Load/displacement curve data were analyzed for slope and displacement.

Results: For larger diameter rings (180mm) there was no statistically significant difference in axial stiffness between the transverse wires (with 2 rings) and the half pins (p> 0.05). For 155mm diameter rings half pins provided statistically higher axial stiffness than transverse wires (p= 0.036). Half pins gave significantly more torsional stiffness for both ring diameters when compared to transverse wires (p< 0.05). As in axial stiffness, small diameter rings showed increased stiffness in torsion. There was an increase in axial and torsional stiffness as the divergence angle between the wires or pins increased (p< 0.05).

Conclusion and clinical relevance: Half pins provide greater stiffness to TSF frames and allow axial micro-motion as well. This work provides a rationale for clinical decision making in construction of a TSF frame.

Introduction: Scoliosis surgery involves major blood loss, at times exceeding estimated blood volume.

Aim: To evaluate the effects of implementing blood conservation strategies (including cell salvage, controlled hypotension and anti-fibrinolytic drugs) on transfusion requirements in adult patients undergoing scoliosis correction surgery. To establish a protocol for cross matching of blood.

Study Design: We retrospectively studied 50 consecutive adult patients who underwent scoliosis correction surgery (anterior, posterior or combined) between 2003 and 2007. All patients were anaesthetised by the same anaesthetist who implemented a standard transfusion protocol. Age, BMI, pre and post operative haemoglobin, levels fused, duration of surgery, hospital stay, antifibrinolytics used and blood transfused was noted.

Results: 50 patients with mean age 24.6 years and mean BMI 21.9 kg/m2 were studied. 14 patients had anterior surgery, 19 patients had posterior surgery and 17 had combined anterior and posterior procedures. Mean number of levels fused was 9.5 (6–15) and mean duration of surgery was 284.6 minutes (135–550 minutes). Anti-fibrinolytics were used in 31 patients (62%), Aprotinin in 21(42%) and Tranexamic acid in 10(20%). Mean blood loss in patients who received anti fibrinolytics was 530mls while mean blood loss in the other patients was 672mls. (p< 0.05). Blood transfusion was not required in any of the patients undergoing anterior correction only while 7 patients (41%) undergoing anterior and posterior correction and 3 patients (15.8%) undergoing posterior correction only required blood transfusion. Mean volume of cell saved blood re-transfused was 693.8 mls and mean hospital stay was 9.2 days. Mean pre-op haemoglobin was 13.2 g/dl (10.4–17.4) and mean post-op haemoglobin was 10.7 g/dl (7.7–15). 4 patients (8%) required intra and post-operative blood transfusion while 6 patients (12%) required blood transfusion postoperatively.

Conclusion: Use of anti-fibrinolytics like Aprotinin and Tranexamic acid reduces blood loss in scoliosis surgery. In the current scenario, with Aprotinin no longer available for use, our study would recommend the use of Tranexamic acid alongwith other blood conservation measures.

In our unit we do not have blood cross matched for anterior surgery alone.

Introduction: Sacroiliac joint (SIJ) is a diarthrodial joint and can often be a source of chronic low back pain complex. We present a percutaneous technique for SIJ fusion and the functional and radiological outcome following the arthrodesis.

Aims and Objectives: To evaluate the functional and radiological outcome following percutaneous technique for SIJ fusion with HMA (Hollow modular anchor-age) screws.

Materials and Methods: 15 consecutive patients operated for SIJ fusion between Sep 2004 and Aug 2007 were included in the study. The diagnosis was confirmed with MRI and diagnostic injections. Pre-operative and post-operative functional evaluation was performed using SF-36 questionnaire and Majeed’s scoring system. Postoperative radiological evaluation was performed using plain radiographs. The Hollow modular anchorage (HMA) screws (Aesculap Ltd, Tuttlingen) packed with bone substitute were implanted percutaneous under fluoroscopic guidance

Results: The study group included 11 females and 4 males with a mean age of 48.7 years. Mean follow-up was 14 months. Mean SF-36 scores improved from 37 to 80 for physical function and from 53 to 86 for general health. The differences were statistically significant (Wilcoxon signed rank test; p < 0.05). Majeed’s score improved from mean 37 preoperative to mean 79 postoperative. The difference was statistically significant (student t test, p< 0.05). 13 had good to excellent results. The remaining 2 patients had improvement in SF-36 from mean 29 to 48. Persisting pain was potentially due to coexisting lumbar pathology. Intra-operative blood was minimal and there were no post operative or radiological complications in any patient.

Conclusion: Percutaneous HMA screws are a satisfactory way to achieve sacro-iliac stabilisation.

We reviewed 15 consecutive patients, 11 women and four men, with a mean age of 48.7 years (37.3 to 62.6), who between July 2004 and August 2007 had undergone percutaneous sacroiliac fusion using hollow modular anchorage screws filled with demineralised bone matrix.

Each patient was carefully assessed to exclude other conditions and underwent pre-operative CT and MR scans. The diagnosis of symptomatic sacroiliac disease was confirmed by an injection of local anaesthetic and steroid under image intensifier control.

The short form-36 questionnaire and Majeed’s scoring system were used for pre- and post-operative functional evaluation. Post-operative radiological evaluation was performed using plain radiographs.

Intra-operative blood loss was minimal and there were no post-operative clinical or radiological complications. The mean follow-up was for 17 months (9 to 39). The mean short form-36 scores improved from 37 (23 to 51) to 80 (67 to 92) for physical function and from 53 (34 to 73) to 86 (70 to 98) for general health (p = 0.037). The mean Majeed’s score improved from 37 (18 to 54) pre-operatively to 79 (63 to 96) post-operatively (p = 0.014). There were 13 good to excellent results. The remaining two patients improved in short form-36 from a mean of 29 (26 to 35) to 48 (44 to 52). Their persistent pain was probably due to concurrent lumbar pathology.

We conclude that percutaneous hollow modular anchorage screws are a satisfactory method of achieving sacroiliac fusion.

Introduction: Complex fractures and singular acute orthopaedic admissions in an individual hospital form only a small proportion of admissions. An average orthopaedic surgeon does not gain and maintain enough experience to provide proficient care. Referral with in the department to a sub-specialist for that anatomical region is forming a norm. We studied the practice in our department to assess how much specialist care we provide.

Materials & Methods: Prospective study over four month’s period with specialist referrals reported by teams and Trauma Fellow. We observed the time spent before making the referrals and that taken by specialists in carrying out management. The spectrum of investigations by various specialist teams was also noted. Number of referrals made to each sub speciality was observed.

Results: Of a total of 836 acute admissions in the department over this four months period, 98 (11.7%) were referred to sub-specialists. Referrals were made on an average of 1.8 days after admission and were seen by the specialist after another 2.1 days. Average time to surgery was 4.7 days after referral. Special Imaging investigations were performed in 84 (86%) patients of whom 31 had been organised before the referral was made. 81 (82%) patients were operated by the specialist teams while rest underwent conservative treatment.

Discussion: With the changing structure and decreasing duration of higher specialist training, expertise in complex trauma is expected to be limited to the anatomical region of surgeons’ interest. Specialist management provides better patient care with improved satisfaction.

Conclusion: In the modern orthopaedic practice with intensive but limited expertise, specialist referrals are the acceptable solution both to the patient and the provider. This should be encouraged. Specialists should provide appropriate investigation and referral protocols.

Introduction: Trauma surgery creates enormous mental stress for operating surgeons, especially in trainees. This is responsible for sympathetic hyperactivity which can be measured by various cardio vascular variables. Air Traffic control is recognised as one of the most stressful occupations with accepted risks and incorporated remedies. We compared the stress during surgery with that experienced by air traffic controllers.

Materials & Methods: The study included 40 trainee doctors. We obtained multiple readings of heart rate, diastolic and systolic Blood Pressure with ambulatory monitoring methods when they operated. This was compared to their resting measurements obtained at home. Similar measurements were performed for Air Traffic controllers, while at work and at home.

Results: The heart rate and blood pressure were increased at the beginning and during surgery. Student t test was applied to compare the mean values obtained intra-operatively and in resting conditions. This suggested the increase to be statistically significant. This increase in autonomic function variables was compared with the values similarly obtained for Air Traffic Controllers. Operating surgeons manifested significant increase in comparison to the other group.

Discussion: Stress can not be eliminated but can be over come with experience. Recurrent sympathetic hyperactivity may contribute to various stress related ailments. As in Air Traffic controllers, stress should be accepted as integral part of occupation. Stress relieving manoeuvres should form an important part of surgeons’ occupational health and medical school/ foundation years curriculum.

Conclusions: Surgeons experience more emotional and mental stress than occupations accepted to be most stressful.

Introduction: The transverse metatarsal arch is the subject of some controversy as there isn’t a clear consensus as to whether there is a transverse arch (TMA) in stance phase. The current treatment options of forefoot pathology focus on the need to harmonise the TMA by the use of osteotomies such as the Weil osteotomy.

Materials and Methods: A retrospective study of 75 feet (62 patients) with a mean follow up of 19 months. Patients underwent clinical, pedobarographic and radiological assessment. ‘Metatarsal skyline Views’ (MSV) were procured to assess the plantar profile of the TMA following Weil osteotomy. The feet were assessed using AOFAS, Foot Function Index, SF-36 and Manchester-Oxford Foot Questionnaires.

Results: 69 feet showed good to excellent results with a normal MSV plantar profile. 6 feet had recurrent meta-tarsalgia with callosities and abnormal MSV profiles. These results correlated well with pedobarography.

Discussion: The angle of Weil osteotomy is usually referenced relative to the floor irrespective of the plantar angulation of metatarsal. As different metatarsals had varying plantar angulations, the weight bearing metatarsal skyline view was used to ascertain the plantar profile of the metatarsals before, during and after surgery. This was also used to determine the amount of dorsal displacement required in addition to shortening in order to harmonise both length and plantar profile.

Conclusion: The use of the Metatarsal skyline view has significantly improved our planning of the angles of the Weil osteotomy.We suggest that the reference for the osteotomy should be the plantar angulation of the metatarsal rather than the floor. It has made the intra-operative assessment of the osteotomy easier and has improved our understanding of the osteotomy and its influence on the forefoot plantar profile.

Introduction: The transverse metatarsal arch is the subject of some controversy as there isn’t a clear consensus as to whether there is a transverse arch (TMA) in stance phase. The current treatment options of forefoot pathology focus on the need to harmonise the TMA by the use of osteotomies such as the Weil’s.

Materials and Methods: A retrospective study of 75 feet (62 patients) with mean follow up of 19 months. Patients underwent clinical, pedobarographic and radiological assessment. ‘Metatarsal skyline Views’ (MSV) were procured to assess the plantar profile of the TMA following Weil osteotomy. The feet were assessed using AOFAS, Foot Function Index, SF-36 and Manchester-Oxford Foot Questionnaires.

Results: 69 feet showed good to excellent results with a normal MSV plantar profile. 6 feet had recurrent metatarsalgia with callosities and abnormal MSV profiles. These results correlated well with pedobarography.

Discussion: The angle of Weil osteotomy is usually referenced relative to the floor irrespective of the plantar angulation of metatarsal. As different metatarsals had varying plantar angulations, the weight bearing metatarsal skyline view was used to ascertain the plantar profile of the metatarsals before, during and after surgery. This was also used to determine the amount of dorsal displacement required in addition to shortening in order to harmonise both length and plantar profile.

Conclusion: The use of the Metatarsal skyline view has significantly improved our planning of the angles of the Weil osteotomy. We suggest that the reference for the osteotomy should be the plantar angulation of the metatarsal rather than the floor. It has made the intraoperative assessment of the osteotomy easier and has improved our understanding of the osteotomy and its influence on the forefoot plantar profile.

The aim of this study is to assess the extent of osteolysis around a TKR which would then help in effective planning of revision surgery.

Osteolysis around a TKR can be difficult to identify in plain radiographs because this typically occurs in low radiodensity cancellous bone of distal femur and proximal tibia. These can often look innocuous and benign allowing the surgeon to fall into a false sense of security.

We discuss the use of 3 dimensional CT scan in 7 cases with pre revision initially unsuspected massive osteolysis and its usefulness in planning appropriate implant and/or bone grafting technique in revision surgery.

6/7 knees had a primary cruciate retaining knee implant and the mean time to revision surgery was 11 years and 8 months

Based on our pre operative CT assessment we were able to plan and effectively undertake 3 custom built prosthesis and 4 stemmed revision implants along with the use of adjunct bone additives including allograft.

On the basis of this experience we would recommend the routine use of a 3D CT scan in preoperatively assessing a revision TKR and would caution the appearance particularly of the ‘posterior femoral bubble’ as it often belies a large osteolytic cavity.