Aim

The aim of our study was to assess lateral tracking of the patella with differing designs of Total Knee Arthroplasty (TKA) and compare to that of the native patella.

Introduction: In recent years, there has been a significant advancement in our understanding of femoro-acetabular impingement and associated labral and chondral pathology. Surgeons worldwide have demonstrated the successful treatment of these lesions via arthroscopic and open techniques. The aim of this study is to validate a simple and reproducible classification system for acetabular chondral lesions.

Methods: In our classification system, the acetabulum is first divided into 6 zones as described by Ilizalithurri VM et al [Arthroscopy 24(5) 534–539]. The cartilage is then graded as 0 to 4 as follows: Grade 0 – normal articular cartilage lesions; Grade 1 softening or wave sign; Grade 2 – cleavage lesion; Grade 3 – delamination and Grade 4 -exposed bone. The site of the lesion is further typed as A, B or C based on whether the lesion is 1/3 distance from acetabular rim to cotyloid fossa, 1/3 to 2/3 distance from acetabular rim to cotyloid fossa and > 2/3 distance from acetabular rim to cotyloid fossa.

For validating the classification system, six surgeons reviewed 14 hip arthroscopy video clips. All surgeons were provided with written explanation of our classification system. Each surgeon then individually graded the cartilage lesion. A single observer then compared results for observer variability using kappa statistics.

Results: We observed a high inter-observer reliability of the classification system with a kappa coefficient of 0.89 (range 0.78 to 0.91) and high intra-observer reliability with a kappa coefficient of 0.91 (range 0.89 to 0.96).

Discussion: In conclusion we have developed a simple reproducible classification system for acetabular cartilage lesions.

Introduction: The purpose of this study was to assess the efficacy and complications associated with revision hip arthroplasty undertaken in patients under the age group of 55 years.

Methods: A review of our institutions revision hip database showed that 430 revision hip arthroplasties undertaken over the past 9 years had a minimum follow up of 2 years. Of this 84 (56 female, 38 male) patients were under 55 years of age (range 2 to 8 years). The index procedures were preformed at an average age of 46 years (range 15 years to 54 years). The single major etiology of failure was aseptic loosening (74%), followed by infection (8%) and recurrent dislocation (7%). In majority of cases uncemented implants were used at revision surgery (91% femoral stem, 100% acetabular cups). Bone grafts were necessary in 39% of cases.

Results: There was 1% incidence of DVT requiring treatment and 1% incidence of deep infection requiring a further revision hip surgery. There were no cases of dislocation in this series. At final follow up satisfactory progress was noted in all cases with a significant improvement in Harris hip score (p < 0.05).

Discussion: In conclusion, revision of hip arthroplasty in patients below 55 years is associated with improvement in function and patient satisfaction. They perform better than older cohorts but not as good as primary THRs. The complication profile is comparable in the two groups.

Introduction: The radiographic evaluation of the antero-lateral femoral head is an essential tool for the assessment of cam type of femoroacetabular impingement. Computerised tomography (CT), magnetic resonance imaging and frog lateral plain radiograph views have all been suggested as imaging options for this type of lesion. The alpha angle is accepted as a reliable indicator of cam type of impingement and this may also be used as an assessment tool for successful operative correction of the cam lesion. The aim of our study was to analyse the reliability of The frog lateral view plain radiographs to analyse the alpha angle in cam femoroacetabular impingement.

Patients and Methods: Thirty two patients who presented with femoroacetabular impingement were studied. Interobserver reliability for assessment of alpha angles on frog lateral radiographic view was analysed using intraclass correlation coefficient. The alpha angles measured on frog lateral views using digital templating tools were compared to those measured on CT scans.

Results: A high interobserver reliability was noted for the assessment of alpha angles on frog lateral views with a correlation coefficient of 0.83. The average alpha angles measured on frog lateral views was 58.71 degrees (range 32 to 83.3). The average alpha angle measured on CT was 65.11 degrees (range 30 to 102). However, a poor correlation (Spearman r of 0.2) was noted between the measurements using the two systems.

Conclusions: Frog lateral plain radiographs are not reliable predictors of alpha angle. Various factors may be responsible for this such as the projection of the radiographs, patient positioning and quality of images. CT imaging may be necessary for accurate measurement of the alpha angle.

Introduction: Blood transfusion is not uncommon in patients following joint replacement surgery. However, allogeneic transfusion is associated with potential risks ranging from immune mediated allergic reactions to transmission of blood-borne organisms. Furthermore its use has a significant economical impact on healthcare services.

Methods: A retrospective audit of the case notes and haematological records of 196 patients who underwent primary total hip (THR), resurfacing hip (BHR) or total knee replacement (TKR) was carried out. Patients were routinely cross-matched for 2 units of blood if their pre-operative haemoglobin (Hb) levels were < 12g/dL in our cohort. Patient details including age, sex, BMI, comorbidities, and ASA grade were also collected. Surgical parameters such as operation time, tourniquet time (for TKR procedures) and trigger haemoglobin levels (Hb) with timing of transfusion were noted. Statistical analysis was undertaken to identify risk factors for transfusion.

Results: Forty-seven (24%) patients were transfused in our cohort. 78.7% of these patients were appropriately transfused with a trigger Hb of < 8g/dL. Patients transfused with a trigger Hb of > 8g/dL were no different with respect to demographics, procedure type and comorbidities. The average postoperative time interval to transfusion was 2.1 days. Five patients required an intra-operative transfusion. The mean pre-operative Hb levels in transfused and non transfused patients were 12.4 g/dL and 13.5 g/dL respectively. The mean number of units transfused was 2.31. A total of 109 units of blood were used: of these 70 units were cross-matched pre-operatively.

Univariate analysis established a significant relationship between the need for postoperative transfusion and preoperative Hb levels (p< 0.0001), length of surgery (p=0.01), age (p=0.03), history of respiratory disease (p=0.028) and hypertension (p=0.01). There was no significant relationship with respect to ASA grade and procedure type. Multivariate logistic regression analysis revealed pre-operative Hb (p< 0.0001) and age (p=0.015) as the strongest predictors of the need for post-operative transfusion. There is a strong correlation between length of surgery and time interval to transfusion (p=0.037).

Conclusion: Utilisation rates of blood products after primary hip and knee arthroplasty procedures exceed that of what is available from pre-operative cross-matching. In our institution more than 20% of patients may have been transfused inappropriately based upon local guidelines. The decision to cross-match blood pre-operatively for elective arthroplasty procedures should be re-evaluated in light of both patient age and pre-operative Hb levels. Postoperative monitoring of Hb levels should be undertaken early in patients with a prolonged duration of surgery.

We investigated the hypothesis that autologous bone marrow stromal cells (BMSC) sprayed on the surface of acetabular cups would improve bone formation and bone implant contact.

Total hip replacements were implanted in 11 sheep, randomly assigned to receive either acetabular implants sprayed with autologous BMSCs suspended in fibrin (study group) or fibrin only (control group). Sheep were sacrificed after six months and the acetabulum with the implant was retrieved and prepared for undcalcified histology. Implant bone contact in both groups was compared, by microscopically noting the presence or absence of new bone or fibrous tissue along the implant at 35 consecutive points (every 1000 μm). The observers undertaking the histological analysis were blinded.

Significantly increased bone implant contact was noted in the BMSC treated group 30.71% ± 2.95 compared to the control group 5.14% ± 1.67 (p = 0.014). The mean thickness of fibrous tissue in contact with the implant was greater at the periphery 887.21mm ± 158.89 and the dome 902.45mm ± 80.67 of the implant in the control group compared to the BMSC treated group (327.49mm ± 20.38 at the periphery and 739.1 mm ±173.72 at the centre). Conversely direct bone contact with the implant surface was significantly greater around the cups with stem cells.

BMSC sprayed on surface of implants improves bone implant contact. Spraying acetabular cups using stem cells could be used in humans where acetabular bone contact is compromised such as in revision procedures.

Our aim was to ascertain the opinion of Orthopaedic Consultants, General Practitioners, and Patients on the proposed primary care based follow up of joint replacements.

An email questionnaire was sent Orthopaedic Consultants registered with the BOA. Responders had to answer simple questions regarding follow up practices after hip and knee arthroplasty and safe alternatives to the existing system. General practitioners in London were sent a different questionnaire to assess their familiarity with follow up of arthroplasty patients and their competence in identifying complications. Finally, arthroplasty patients were directly questioned on their preference for follow up.

Eigthy-one Orthopaedic Consultants who undertake lower limb arthroplasty responded, 89.06% advocated follow up and review of radiographs by the surgeon. The Arthroplasty Practitioner, the Radiologist and the Physiotherapist were deemed suitable for follow up of patients by 50%, 14.06% and 4.69 % respectively. All responders unanimously disagreed with initial follow up by General Practitioners (0%). However, after a 12 month review, 30.15% thought primary arthroplasty patients could be discharged to the care of their General Practitioner and 11.11% were happy to discharge revision arthroplasty patients. Of the 52 General Practitioners who returned our questionnaire, only 37% were confident of interpreting symptoms related to prosthetic loosening or infection and 98% did not feel competent identifying radiological changes after arthroplasty. 94% of the General Practitioners did not think that they would be happy to follow up arthroplasty patients even if they were offered further training. The reasons for this were lack of specialty skills, work-load concerns, funding issues and surgeons’ duty of care towards the patient. All of the 104 patients who were questioned preferred to be followed up by the arthroplasty team.

In conclusion, Orthopaedic Surgeons, General Practitioners and patients prefer a hospital based dedicated Orthopaedic team for the post operative follow-up of arthroplasty patients.

Radiographs are frequently ordered following acute knee injury. However, it is suggested that only 6 % of patients with a knee trauma have a fracture. Decision rules such as the Ottawa rules and the Pittsburgh rules have been developed to reduce the unnecessary use of radiographs following knee injury.

We prospectively reviewed all acute knee injury patients who were referred to our clinic from the emergency department over a 3 month period. The reason for ordering radiographs was analysed. The Ottawa and the Pittsburgh rules were applied to individual patients to evaluate the need for radiographs. In patients with a diagnosis of fracture, the accuracy of the Ottawa and the Pittsburgh rules was studied.

A total, of 106 patients were referred to the acute knee clinic from the emergency department. 95.28 % (101) of these patients had radiographs of their knee in the emergency department. Five (4.72%) patients had a fracture of their knee and all these cases, the Ottawa and the Pittsburgh knee rules for ordering radiographs was fulfilled. In a vast majority of cases without any fracture, the clinical reason for ordering radiographs was not clear. Using the Ottawa rules for knee radiography 25.47% (27) radiographs could be avoided without missing a fracture. Using the Pittsburgh rules, 30.19 % (32) knee radiographs could be avoided without missing a fracture.

The Ottawa and the Pittsburgh rules have a high sensitivity for the detection of knee fractures. Use of these rules can aid efficient clinical evaluation of the knee in an emergency situation without adverse clinical outcome. They may also have an implication on reducing the work load of radiology department and reduction of health costs.

Radiographic evaluation of the anterolateral femoral head is an essential tool for the assessment of cam type of femoroacetabular impingement. Computerised tomography (CT), magnetic resonance imaging and frog lateral plain radiograph views have all been suggested as imaging options for this type of lesion. Alpha angle is accepted as a reliable indicator of cam type of impingement and this may also be used as an assessment tool for successful operative correction of the cam lesion.

The aim of our study was to analyse the reliability of frog lateral view plain radiographs to analyse the alpha angle in cam femoroacetabular impingement.

Thirty two patients who presented with femoroac-etabular impingement were studied. Interobserver reliability for assessment of alpha angles on frog lateral radiographic view was analysed using intraclass correlation coefficient. The alpha angles measured on frog lateral views using digital templating tools were compared to those measured on CT scans.

A high interobserver reliability was noted for the assessment of alpha angles on frog lateral views with a correlation coefficient of 0.83. The average alpha angles measured on frog lateral views was 58.71 degrees (range 32 to 83.3). The average alpha angle measured on CT was 65.11 degrees (range 30 to 102). However, a poor correlation (Spearman r of 0.2) was noted between the measurements using the two systems.

Frog lateral plain radiographs are not reliable predictors of alpha angle. Various factors may be responsible for this such as the projection of the radiographs, patient positioning and quality of images. CT imaging may be necessary for accurate prediction of alpha angle.

The aim of our study was to determine the usefulness of preoperative digital templating of cementless total hip arthroplasty (THA).

60 consecutive cementless THA (synergy stem & reflection cup) were templated digitally by two senior hip arthroplasty fellows (GM, YG) independently. A metallic marker ball of known diameter was used in all images to help scale for magnification. A blinded observer then collated information on the actual implant sizes, size of head component, offset, and level of neck cut intraoperatively. This was used to statistically analyse the correlation (Interclass correlation coefficient) between the digitally templated implant sizes and actual implant sizes used and the reliability of digital templating.

A high rate of coincidence between digitally templated estimates and actual implant sizes was noted for both groups of templates. A high intraclass correlation coefficient (ICC) for the acetabular cup, stem and head were noted (ICC of 0.825, 0.794, and 0.884 respectively). Moderate agreement was noted for neck cut (ICC of 0.567) and leg length (ICC of 0.612).

In conclusion, digital templating can reliably estimate implant sizes in cementless total hip arthroplasty. Valuable information on neck cut and leg length can be obtained by preoperative templating.

We describe our novel approach to managing infected periprosthetic fractures using a revision implant for temporary fracture stabilisation.

A series of 12 consecutive patients aged between 74 and 83 years (average age 81.51, SD 6.32) who were referred to the senior author with periprosthetic fracture and microbiologically proven infection, were managed by radical debridement and antibiotic therapy along with temporary implantion of a long stem cannulated, proximally hydroxyappatite coated and distally locked femoral prosthesis (Cannulock, Orthodesign, Christ-church, UK). Strut grafts, demineralised bone matrix and cable plating system where used in addition where indicated. Post operatively patients were allowed to mobilise as allows and antibiotics were continued until biochemical markers returned to normal.

A good clinical outcome and excellent functional outcome was noted in all 12 cases. No cases of immediate post operative complications such as DVT or PE were noted in any cases. In particular there were no instances of infections associated with prolonged immobilisation and hospital stay. Ten patients underwent a definitive revision hip replacement procedure within an average of 4.3 weeks (range 3.9 to 5.7, SD 2.15). Two patients required a second debridement and delayed definitive treatment due to persistently high inflammatory markers.

We believe that this novel approach significantly improves functional outcome in the management of infected periprosthetic fractures.

Despite advances in total hip arthroplasty, failure of acetabular cup remains a concern. The role of bone marrow stromal cells (BMSCs) to aid osseointegration of orthopaedic implants have been recently studied. We investigated the hypothesis that autologous BMSCs sprayed on the surface of acetabular cups would improve bone formation and bone implant contact.

Total hip replacements were implanted in 11 sheep, randomly assigned to receive either acetabular implants sprayed with autologous BMSCs suspended in fibrin (study group) or fibrin only (control group). Sheep were sacrificed after six months and the acetabulum with the implant was retrieved and prepared for undecalcified histology. Implant bone contact in both groups was compared microscopically, by noting the presence or absence of new bone or fibrous tissue along the implant at 35 consecutive points (every 1000 μm). The observers undertaking the histological analysis were blinded.

Significantly increased bone implant contact was noted in the BMSC treated group 30.71% ± 2.95 compared to the control group 5.14% ± 1.67 (p = 0.014). The mean thickness of fibrous tissue in contact with the implant was greater at the periphery 887.21mm ± 158.89 and the dome 902.45mm ± 80.67 of the implant in the control group compared to the BMSC treated group (327.49mm ± 20.38 at the periphery and 739.1 mm ± 173.72 at the centre). Conversely, direct bone contact with the implant surface was significantly greater around the cups with BMSCs.

Our data demonstrate that BMSC sprayed on surface of acetabular implants improves bone implant contact. Spraying acetabular cups using stem cells could be used in humans where acetabular bone contact is compromised such as in revision procedures.

Purpose of study: The aim of this study was to look at the clinical outcome of PLC interference screws in knee ligament reconstruction surgery.

Materials & Results: We prospectively followed up 60 patients who underwent primary anterior cruciate ligament (ACL) reconstructions using PLC (Calaxo; Smith & Nephew) screws to secure the graft in the tibial tunnel. [(35 male patients & 25 female). Average age 33.72 years]. In addition to the ACL, PLC screws were used to reconstruct the posterior cruciate ligament in one case and posterior cruciate ligament with the posterolateral corner in another three patients. Hamstring autografts were routinely preferred except in multiple ligament reconstructions, when allografts were also used.

25 (41.67%) patients presented with complications (synovitis in 10 patients, prominent tibial swelling in 21 patients and both in 7 patients). In comparison, no complications were noted in 60 other age and sex matched patients in whom PLLA (Bio RCI; Smith & Nephew) screws were used by the same surgeon.

The symptoms in the PLC screw group often settled conservatively and did not affect knee stability. 6 patients underwent exploration of the tibial tunnel site. A sterile white cheesy substance was noted which was removed, leaving an empty tibial tunnel. The ACL graft was found to be well attached to tibial tunnel in all cases. The PLC screw size did not have any correlation to the occurrence of complications. 2 patients required multiple washouts, one of whom developed a deep infection.

Conclusion: The degradation of PLC screws does not follow the gradual and controlled pattern demonstrated in the ovine model [Walsh WR et all, Arthroscopy. 2007 Jul;23(7):757–65. Comparison of PLLA and PLC interference screws in an ovine ACL reconstruction model.]. The unpredictable screw resorption, and the reaction to it can lead to serious clinical consequences.

Purpose of study: The all inside fixation of meniscal tears with bio-degradable products is popular because of its fast application and reduction in risks of serious neurovascular complications. We reviewed the results of a consecutive series of all inside meniscal repairs performed by the senior author in a carefully selected patient population.

Materials & Results: The senior author performed 104 consecutive meniscal repairs (54 lateral & 50 medial meniscus) in 96 patients (66 male, 30 female), using all inside meniscal repair systems (18 Bionxx, 86 FasT Fix; Smith & Nephew). The average patient age at the time of repair was 31.6 years (range 17 – 46 years). On an average 2 arrows (range 1–4) were used in the Bionnx system and 2.5 sutures (range 1–7) for the Fas T fix system. The predominant tear pattern was a peripheral red on white type tear involving the body and posterior horn. Concomitant ACL reconstruction was undertaken in 50% cases. In 26.9 % cases the repaired meniscus was partially trimmed prior to repair and in 25 % cases a tear of the non repaired meniscus was stabilised by trimming alone. A further arthroscopic partial menisectomy was performed in 12 cases of failed repair (4 Bionxx, 8 Fas T fix) at an average of 16.16 months (range 1 month – 44 months). None of the other patients had symptoms or signs suggestive of meniscal pathology on follow up (minimum 12 months). The repair was successful in 90.69 % of Fas T fix repairs and 77.78 % of Bionxx repairs. The meniscal repair failure rate in the group which had an ACL reconstruction was 5.77 %. No major intra or post operative complications were noted.

Conclusion: Successful meniscal preservation is feasible by using an all-inside meniscal repair device. Patient selection and due consideration to the site and geometry of the meniscal tear is crucial.

Purpose of study: The diagnosis of meniscal tears is usually based on the patient’s history and on specific physical tests. Magnetic resonance imaging (MRI) and arthroscopy is often necessary for diagnosis.

Theofilos Karachalios et al. described the new ‘Thessaly test’ and concluded that it could be safely used as a first line screening test for the selection of patients who need arthroscopic meniscal surgery (Ref: J Bone Joint Surg Am. 2005 May; 87(5):955–62). Our objective was to study the role of physical diagnostic tests in screening for meniscal tears and to validate the diagnostic accuracy of the Thessaly test.

Methods & Results: We examined 109 patients [(80 male, 29 female), average age 39.11 years, range (16–66)] who presented with a history suggestive of a meniscal tear. Joint line tenderness,

McMurray’s test and the Thessaly test were assessed by an independent investigator blinded to any imaging data in all patients. MRI and subsequent arthroscopy results were then collated.

Our study showed a much lower diagnostic accuracy for the Thessaly test (61.25 % for medial meniscus and 80 % for lateral meniscus) It is comparable to McMurray’s test (57.14 % for medial meniscus and 77.38 % for lateral meniscus). The Joint line tenderness test has a far superior diagnostic accuracy (80.95 %for medial meniscus and 90.48 % for lateral meniscus). Combining the joint line tenderness test with McMurrays test or the Thessaly test further increased the diagnostic accuracy. Magnetic resonance imaging (MRI) detected 96% of meniscal tears. Arthroscopy was diagnostic and therapeutic in all cases.

Conclusion: Physical tests may not always be diagnostic of meniscal tears. MRI and arthroscopy may be essential in dubious clinical presentations. In our study the Thessaly test in isolation did not have the highest diagnostic accuracy for the detection of meniscal tears but helps increase diagnostic certainty when combined with standard tests.

Introduction: Aseptic loosening at the bone-implant interface of THA acetabular components is a significant cause of implant failure. This loosening has been attributed either to wear particle-induced osteolysis or to the effects of joint fluid-pressure. It may be possible to prevent the loosening of implants by improving fixation between the bone and implant, or promoting the growth of a biological bony seal, in order to prevent the influx of wear particles or pressurized joint fluid. Additionally in revision implants it is important to promote osseointegration in situations where bone stock may be limited. The hypothesis of this study was spraying autologous BMSCs in fibrin glue onto the surface of HA-coated acetabular components would increase bone formation around the implant and improve bone-implant contact.

Materials and Methods: Bone marrow was aspirated from the iliac crest of six goats, and BMSCs isolated and expanded in vitro. 10 x 10e6 BMSCs were suspended in reconstituted thrombin pre-operatively. A standard posterior approach was used. The acetabular shell was then coated with 2 ml of fibrin glue, with (n=6) or without 10 x 10e6 autologous BMSCs (n=6), and the acetabular component impacted into position. Antibiotic and analgesic prophylaxes were carried out. All animals were weight bearing within 48 hours post-operatively. Walking and ground reaction forces were assessed pre-operatively, as well as 6 and 12 weeks post-operatively. Results were expressed as a percentage of force transmitted through the right leg versus the left leg. After 12 weeks, the acetabulae were retrieved, and processed for histology. The percentage of new bone around the cups was measured within 5 radial zones, using image analysis. Bone-implant contact was also analysed between the new bone and implant surface. Mann Whitney U test was used to show statistical significance.

Results: New bone formation in Zone 5 showed a significant increase in the BMSC group (71.97±10.91%), when compared to the controls (23.85±15.13%, p=0.028). The other zones did not show a significant difference. Overall new bone growth in the BMSC group was 30% greater than the control group (71.42±8.97% and 54.22±16.56%, respectively, p=0.58). Bone-implant contact was significantly improved in the BMSC group (20.03±4.64%), in contrast to the control group (13.71±8.32%, p=0.027). With regards to the force plate analysis, there was no significant difference in loading between groups at both 6 weeks (Controls-79.74±3.63%, BMSCs-59.39±9.33%, p=0.086) and 12 weeks (Controls-86.0%±2.85%, BMSCs-62.33±5.12%, p=0.055).

Discussion and Conclusions: In this study, overall bone growth was greater when cups were treated with BMSCs. Bone-implant contact was significantly improved as well. This study has clinical applications, as using MSCs in fibrin glue promotes a bony seal in contact with the implant which may prevent the migration of particles, or joint fluid, decreasing the likelihood of aseptic loosening of THAs, and improving their longevity. Also, this technique may improve fixation in situations where bone stock is reduced.