One of the main surgical goals when performing a total knee replacement (TKR) is to ensure the implants are properly aligned and correctly sized; however, understanding the effect of alignment and rotation on the biomechanics of the knee during functional activities is limited. Cardiff University has unique access to a group of local patients who have relatively high frequency of poor alignment, and early failure. This provides a rare insight into how malalignment of TKR's can affect patients from a clinical and biomechanical point of view to determine how to best align a TKR. This study aims to explore relationship clinical surgical measurements of Implant alignment with in-vivo joint kinematics.

28 patient volunteers (with 32 Kinemax (Stryker) TKR's were recruited. Patients undertook single plane video fluoroscopy of the knee during a step-up and step-down task to determine TKR in-vivo kinematics and centre of rotation (COR). Joint Track image registration software (University of Florida, USA) was used to match CAD models of the implant to the x-ray images. Hip-Knee-Ankle (HKA) was measured using long-leg radiographs to determine frontal plane alignment.

Posterior tibial slope angle was calculated using radiographs. An independent sample t-test was used to explore differences between neutral (HKA:-2° to 2°), varus (≥2°) and valgus alignment (≤-2°) groups. Other measures were explored across the whole cohort using Pearson's correlations (SPSS V23).

There was found to be no statistical difference between groups or correlations for HKA. The exploratory analysis found that tibial slope correlated with Superior/Inferior translation ROM during step up (r=−0.601, p<0.001) and step down (r=−.512, p=0.03) the position of the COR heading towards the lateral (r=−.479, p=0.006) during step down.

Initial results suggest no relationship between frontal plane alignment and in-vivo. Exploratory analyses have found other relationships that are worthy of further research and may be important in optimizing function.

The TruFit® plug is a cylindrical scaffold designed to bridge defects in articular cartilages. It is a porous structure with interconnected pores, which gives it the capability of providing a framework for the ingrowth new tissue and remodelling to articular cartilage and bone.

The aim of this study was to assess the radiological incorporation of TruFit® Plugs using MRI. Between December 2007 & August 2009, 22 patients underwent treatment of a chondral or osteochondral lesion using one or more TruFit Plugs. At a minimum of 2 years, 10 patients (12 lesions) were MRI scanned and assessed with a modified MOCART Scoring system by an independent Consultant Musculoskeletal Radiologist. 8 patients were no longer contactable and 4 patients declined MRI as their knee was asymptomatic.

8 of 12 lesions showed congruent articular cartilage cover with a surface of a similar thickness and signal to the surrounding cartilage and reconstitution of the subchondral bone plate. 2 lesions had a thicker congruent articular surface with a similar signal to the surrounding articular cartilage without restoration of the subchondral bone plate. 2 lesions showed no graft incorporation at all and were filled with granulation tissue. Full incorporation of the bony portion of the plug had occurred in only 3 lesions with partial incorporation in 7 lesions. The remaining portion of these 7 lesions looked cystic on MRI.

The MRI appearances of the TruFit® Plug at 2 years are encouraging with the majority (83%) showing good restoration of the articular surface with tissue of similar thickness, congruity and signal as the surrounding articular cartilage. However complete incorporation of the TruFit® Plug is rare and cystic change is common. The significance of this cystic change is not clear.

Background

Patellofemoral replacement is an established intervention in selected patients with severe isolated patellofemoral osteoarthritis. FPV (Wright Medical, UK) is a third generation patellofemoral arthroplasty implant and is the second most used after AVON in National Joint Registry for England and Wales. Reports of survivorship and functional of this implant are scarce in literature.

Purpose

To review the Five year survivorship of Kinnemax TKA performed at the NHS Treatment Cantre, Weston-Super-Mare (WSM), and compare it to a similar cohort from our institution.

Purpose of the study: We describe a new modified arthroscopic technique of surgically treating avulsion fractures of the tibial eminence using the Scorpion device (Arthrex, Naples, FL).

Methods and results: A 57 year-old female who sustained a type II fracture of the tibial spine was treated with arthroscopic fracture fixation using the Scorpion device to place a whip stitch into the substance of the anterior cruciate ligament (ACL). Tibial tunnels were made on the anteromedial aspect of the tibia using the Acufex ACL guide (Smith and Nephew, Mansfield, MA) and the sutures were passed through these tunnels and tied over a bony bridge. At 6 months after surgery, the patient was asymptomatic and had returned to her daily activities. She had regained full range of movement and had a clinically stable knee, confirmed on KT 2000 arthrometer. Radiographs showed anatomic reduction and fracture union.

Conclusion: The Scorpion device which is commonly used in arthroscopic shoulder surgery provides significant advantages as it can be used arthroscopically to place a whip stitch in the substance of the ACL. The hook at its end can be used to retrieve suture loop from the joint, thus reducing instrumentation and operating time. It is a user friendly arthroscopic technique that restores the necessary tension in the ACL, provides stable fracture fixation, and also results in a cosmetic end result.

Purpose: A relationship between vastus medialis oblique (VMO) strength and anterior pain and disability has been suggested. A biomechanical protocol was used to access the deficiency of the quadriceps muscles in patients with anterior knee pain.

Methods and Results: A biomechanical evaluation was conducted on 54 patients with anterior knee pain (34 females and 20 males). All patient x-rays were normal through interpretation by a blinded radiologist. A Kistler force plate, a VICON motion analysis system and surface electromyography were used to quantify biomechanical function during isometric, walking and squatting exercises.

For 42 of the 54 (78%) subjects, during isometric and walking exercises we observed that activation of the VMO, rectus femoris (RF) and vastus lateralis (VL) muscles of the symptomatic leg was not significantly different from those of the asymptomatic leg (p< 0.01). However, for 31 patients (57%) during the eccentric phase of the squat exercises, the symptomatic leg presented with high activation of VL compared to VMO and RF (p< 0.01). During the concentric phase, 45 patients (83%) presented with higher activation of the VL compared to the VMO.

Conclusion: VMO activity during squatting for the symptomatic patient with anterior knee pain leg differs fundamentally during walking and isometric exercise compared to squatting tasks. Moreover, the relative contribution of the VL compared to the VMO during the eccentric phase of the squat exercises was different to those recorded during the concentric phase. Therefore, we suggest that maximal isometric and or isokinetic exercises are not sufficient to access the quadriceps function in relation to anterior knee pain. A thorough biomechanical assessment, including functional testing to reproduce the patient’s pain and locate the nature of the symptoms is suggested.

Purpose: Anterior cruciate ligament (ACL) reconstruction techniques have traditionally focused on reconstruction only of one bundle of the ACL providing good to excellent results in most cases. Biomechanical studies have shown increased anterior and rotational stability with double bundle(DB) compared to single bundle(SB) anterior cruciate ligament(ACL) reconstruction. A systematic review and meta-analysis was performed to compare double bundle and single bundle methods of anterior cruciate ligament reconstruction.

Methods and results: Medline (1966 onwards), EMBASE (1980 onwards) and the Cochrane database were searched retrieving 8465 possible articles, but only 5 studies fulfilled all the inclusion criteria. To be included, the study had to be prospective, randomised or quasi-randomised, comparing DB and SB grafts inserted using an arthroscopically assisted technique and have a minimum 18 month follow-up for all patients.

358 patients, 190 SB and 168 DB were considered for statistical analysis from these five papers. Outcome measures assessed included pivot shift testing, KT1000 arthrometer testing and IKDC knee scores. Using Review Manager 4.2 for statistical analysis; for dichotomous data, odds ratios and 95% confidence intervals were calculated and for continuous data, weighted mean difference and 95% confidence intervals were calculated.

Patients in the double bundle group were significantly less likely to have a positive pivot shift test (P< 0.0001). KT1000 arthrometer testing demonstrated greater antero-posterior stability with the DB group (P=0.002). There was no difference between the groups in terms of IKDC score.

Conclusion: The use of a double bundle technique improved both anteroposterior and rotational stability but not the clinical IKDC score suggesting that recovery of knee stability alone is not sufficient for achieving a better outcome.

Following introduction of the second offer scheme in April 2004, Cardiff and Vale NHS Trust sent 227 patients (254 knees) to the independent sector treatment centre in Weston-Super-Mare for total knee arthroplasty. The Kinemax total knee system was used in all cases.

There was a perception that there were a large number of dissatisfied patients, and a previous British Orthopaedic Association report (of a 14 case sample) questioned the quality of the surgery performed.

All of the patients concerned were offered a review in order to assess the outcome. Of the 227 patients (254 knees), 77% have been reviewed (167 patients, 190 knees). 23% (59 patients, 64 Knees) have not been seen. Of these, 30 patients (34 knees) declined review on the basis that they were happy with the result of surgery. 14 Patients (15 knees) were unobtainable by post of by phone. A further 12 patients (12 knees) did not attend appointments. 3 Patients (3 Knees) had died.

The total number of re-operations was 27/254, giving a re-operation rate of 10.6%. There were 21 revisions, 17 for aseptic causes (oversized components, malalignment, aseptic loosening) and 4 for infection. There were 6 secondary patella resurfacings.

A life table survivorship analysis was calculated for the 254 knees. The cumulative survival rate at 3 years was 85.8%. These results are considerably worse than those reported in the current published literature. This has resulted in a significant economic impact on our service.

Between 29th May 2001 and 15th May 2003, 233 consecutive Preservation unicompartmental knee replacements (UKR) were performed. Of these, 30 were lateral UKRs (13%) performed in 12 men and 16 women (2 bilateral cases) with a mean age of 67 years (range 36 to 93 years). A metal-backed mobile bearing tibial component was used in 13 knees and an all-polyethylene fixed bearing tibial component in 17 knees. The patients were reviewed prospectively at 1 and 2 years. The 2 year results show no difference in range of motion or function between the mobile and fixed bearing versions of the Preservation knee when used on the lateral side. This is similar to the reported results on the medial side. There were 3 early revisions, all in the mobile bearing group. The incidence of revision has been reduced by the introduction of an improved cementing technique.

The aim of this study was to assess the results of bilateral total knee replacement (TKR) staged one week apart during one hospital admission and compare these results with those of bilateral sequential TKRs and bilateral TKRs performed in 2 separate admissions by a single surgeon using a single prosthesis. Between 5th November 1997 and 10th August 2004, 104 patients underwent bilateral LCS TKRs using the Anteroposterior glide (APG) tibial component. The patients were analysed in 3 groups. The patients in Group 1 underwent bilateral sequential TKR under the same anaesthetic. The patients in Group 2 underwent bilateral TKRs under 2 separate anaesthetics, 7 days apart, during the same admission. The patients in Group 3 underwent bilateral TKR under 2 separate admissions, essentially 2 unilateral TKRs. The patients in Group 1 had shorter operations (p< 0.0001) and shorter hospital stays (p< 0.0001). Patients in Group 2 had less blood loss (p=0.004) but were not transfused any less than the other groups. The complication rate was low and comparable in all groups. There were no in hospital or 30 day deaths in any of the groups. Those patients in Group 3 had worse AKS function scores (p=0.02) and those patients in Group 2 had a significantly better HSS score (p=0.02). There was no significant difference between the groups in terms of range of motion or the AKS Knee score. This study has confirmed a shorter operation and hospital stay when the bilateral TKRs are carried out under the same anaesthetic. These patients also bled the most postoperatively. There was little difference in terms of complications and clinical outcome at a mean follow up of 4 years. With appropriate patient selection, both same anaesthetic and same admission bilateral TKR are safe methods to treat bilateral arthritis.

Introduction: A cementless femoral implant is currently available for hip resurfacing with several theoretical advantages over cemented fixation, one of which is a potential reduction in systemic emboli. A prospective study was undertaken to evaluate the occurrence of systemic emboli using a cementless femoral component for hip resurfacing in comparison to cemented femoral fixation.

Methods: Between November 2004 and December 2005 patients scheduled for elective hip resurfacing for osteoarthritis were consented to undergo hip resurfacing using a cemented femoral component (Articular Surface Replacement or Birmingham Hip Resurfacing) or a cementless femoral component (Bi-coat Cormet Hip Resurfacing). Each case was randomised to femoral venting or no femoral venting. Intra-operative monitoring with a Transcranial Doppler device was used to identify and record systemic emboli throughout each case. Demographic and peri-operative data were collected including mental score and vital observations at day 1 and day 3, and blood loss.

Results: 8 patients (5 vented, 3 unvented) underwent cemented resurfacing and 7 patients (4 vented, 3 unvented) had cementless resurfacing. There was no difference between the two groups for age (mean 56yrs), gender, weight, or ASA status. The mean number of significant emboli (> 12dB) in the cemented group was 8.1 and in the cementless group was 1.7 (significant, p=0.009). Peri-operatively both groups were similar for vital observations, haemoglobin, mental scores and SaO₂. Venting did not influence rate of emboli. However, venting was independently associated with significantly higher drainage (mean 604mls compared to 335mls without venting, p=0.018).

Discussion: This study has shown significantly less systemic emboli occur with the use of a cementless femoral component during hip resurfacing in comparison to a cemented implant. We propose this is due to intra-osseus pressure generated when using cement. The number of emboli is unaffected by femoral venting, but more blood loss occurs after venting.

The aim of this study was to assess the perioperative complications associated with bilateral simultaneous UKR and compare them with those of unilateral UKR and bilateral TKRs. Over a 2 year period, 40 patients underwent bilateral simultaneous Preservation unicompartmental knee replacement UKR. They were compared to 40 matched unilateral UKRs and 28 bilateral simultaneous total knee replacement patients who had their operations during the same time period by the senior author. There was no significant difference between the groups in terms of age, weight, ASA grade and throm-boprophylaxis received. There was no statistically significant difference in the complication rates of all 3 groups. When compared to 2 unilateral UKRs, bilateral simultaneous UKR results in a reduced operative time, blood loss and hospital stay but more blood transfusion. When compared to bilateral TKRs, bilateral simultaneous UKR results in reduced blood loss, reduced blood transfusion and hospital stay but an increased operative time. Bilateral UKR is a useful option in selected patients with bilateral unicompartmental osteoarthritis.

The aim of this prospective cohort study is to compare the early results in a single surgeon series of the mobile and fixed bearing versions of the Preservation UKR for lateral OA. Lateral UKRs were only considered for patients with isolated lateral compartment osteoarthritis with a functioning anterior cruciate ligament. Mild patellofemoral osteoarthritis was not considered a contraindication. If there was any doubt over the condition of the medial compartment or patellofemoral joint, single photon emission computed tomography was performed. Significant uptake it the medial or patellofemoral joint was considered a contraindication. Patients were assessed preoperatively and at 1 and 2 years postoperatively with the American Knee Society Score (AKSS), Oxford Knee Score (OKS) and with anteroposterior, lateral and Rosenberg radiographs.

Between 29^th May 2001 and 15^th May 2003, the senior author (GK) performed 233 consecutive Preservation UKRs. Of these, 30 were lateral UKRs (13%) performed in 12 men and 16 women (2 bilateral cases) with a mean age of 67 years (range 36 to 93 years). A metal-backed mobile bearing tibial component was used in 13 knees and an all-polyethylene fixed bearing tibial component in 17 knees. Patients in the mobile bearing group were significantly younger (t test; p< 0.0001) and had better AKSS knee (Mann-Whitney U test; p=0.05) and AKSS function scores (Mann-Whitney U test; p=0.005). The patients were reviewed after a minimum of 2 years (range 2 to 3.4 years). There was no significant difference between the 2 groups. There had been 3 revisions in the mobile bearing group for tibial loosening and none in the fixed bearing group (chi squared test; not significant). There was 1 tibial periprosthetic fracture in the fixed bearing group. This study shows that the choice of bearing type makes little difference in clinical outcome or range of motion over the first 2 years when using the Preservation Knee. A similar good functional result was obtained with a fixed bearing despite the mobile bearing group being younger and having significantly better preoperative AKS knee and function scores. The 3 revisions for tibial loosening in the mobile bearing group are a concern. However, these results are short-term and there may be improved implant longevity in the long-term with mobile bearing tibial components due to reduced polyethylene wear.

To assess the reliability of the pre-operative measurement methods used in the management of the hallux valgus deformity, five observers assessed 50 pre-operative standing foot radiographs on two occasions in order to assess the reliability of radiological hallux valgus assessment using the inter-metatarsal angle (IMA), hallux valgus angle (HVA) and joint congruency. Five published methods of angle measurements described by Hawkins, Venning and Hardy, Mitchell, Miller and Nestor were used.

Kappa statistics were used to assess the reliability of the diagnosis of congruency. Regarding IMA and HVA, mean values between the methods were assessed by one-way ANOVA. The differences between the methods and observers were assessed by two-way ANOVA.

Results: Diagnosis of congruency showed good agreement (k=0.608) over two occasions, although this did vary by observer.

The mean IMA and HVA measurements varied significantly between methods on both occasions (p< 0.0001). Mitchell’s method had the lowest and Miller’s the highest mean values.

Analysis of variance showed both method and observer variations were significant for IMA. But HVA measurements differed significantly only by observers.

Conclusion: The reliability of IMA and HVA measurements is poor whichever measuring method is used and these methods are not interchangeable. Study papers should state the measurement method used. For the pre- and post-operative assessment the same method should be used.

The aetiology of Panner’s disease is unknown. Thrombophilic states have been implicated in Perthes’ disease but remain controversial. The relationship, if any, between thrombophilia and Panner’s disease is not known.

A 7 year old boy presented with pain and restriction of motion in one elbow with no history of trauma. Radiographs confirmed Panner’s disease. A thrombophilia screen showed an abnormal activated protein C resistance test consistent with the presence of Factor V Leiden in the heterozygous state. Thrombophilia may predispose to thrombotic venous occlusion in bone leading to intramedullary hypertension, anoxia and avascular necrosis. This may explain the aetiology of some cases of Panner’s disease. Resistance to activated protein C is a common heritable thrombophilia. The incidence in the UK is around 1.75%. It is caused by a CGA to CAA substitution at position 1691 of the Factor V Leiden gene. This blocks the binding of activated protein C to prothrombotic Factor V producing thrombophilia. Factor V Leiden carriers are three times more likely to experience clinical venous thrombosis than non-carriers. Whilst this risk does not warrant lifelong anticoagulation, thromboembolic events are more likely to cause problems than Panner’s disease which is essentially self-limiting. Affected patients should avoid other risk factors such as smoking or the combined contraceptive pill.

As Factor V Leiden is common in our population, its presence in this patient may be incidental. Thrombophilia screening should be considered for patients with Panner’s disease. This enables appropriate counselling if a thrombophilic condition is found.

A systematic review was performed to determine the advantages and disadvantages of patellar resurfacing during total knee replacement for osteoarthritis. 3 randomised controlled studies were analysed. These studies recruited 302 knees and 235 knees (78%) were reviewed at least 5 years postoperatively (range 5 to 10 years). Patients undergoing patellar resurfacing received a cemented all polyethylene patella component. A patello-plasty was performed in some of the unresurfaced knees.

For the dichotomous data, odds ratios and 95% confidence intervals were calculated. Each outcome measure tested was assessed for heterogeneity using the Cochran Q test. If significant heterogeneity was present (P< 0.10), data from the studies was not combined. If there was no significant heterogeneity, a combined odds ratio was calculated using a fixed effects model and a Z test was performed to test the overall effect.

Reoperation for patellofemoral problems was significantly more likely in the unresurfaced group (p=0.003). The overall rate for reoperation for a patellofemoral problem was 0.7% in the resurfaced group and 11% in the unresurfaced group. Study data on anterior knee pain could not be analysed together as there was significant heterogeneity. There was no difference between the two groups in terms of revision. This study found no mid- to long-term benefit to leaving the patella unresurfaced.

The choice of graft for anterior cruciate ligament reconstruction remains controversial. A systematic review was performed to compare bone-patella tendon-bone and 4-strand hamstring grafts. Medline (1966 onwards), EMBASE (1980 onwards) and the Cochrane database were searched retrieving 6312 possible articles but only 6 studies fulfilled all the inclusion criteria. To be included, the study had to be prospective, randomised or quasi-randomised, comparing 4SHS and central third BPTB autografts, inserted using an arthroscopically assisted technique and have a minimum 2-year follow up for all patients. These studies recruited 526 patients and 475 were followed for at least 2 years with 235 patients receiving a bone-patella tendon-bone graft and 240 receiving a 4-strand hamstring graft. Overall, there was a greater chance of extension loss (p=0.007) and a trend towards increased patellofemoral joint pain (p=0.09) with a patella tendon graft. With a 4-strand hamstring graft there is a greater loss of hamstring power (p=0.008) and a trend towards an increased chance of a pivot shift > 1 (p=0.12). There was no difference between the 2 groups in terms of lachman testing, chance of returning to the same level of sport, clinical knee scores, graft ruptures or other complications.

A systematic review was performed to determine the advantages and disadvantages of patellar resurfacing during total knee replacement for osteoarthritis. 3 randomised controlled studies were analysed. These studies recruited 302 knees and 277 knees (92%) were reviewed at least 5 years postoperatively (range 5 to 10 years). Patients undergoing patellar resurfacing received a cemented all polyethylene patella component. A patelloplasty was performed in some of the unresurfaced knees.

Each outcome measure tested was assessed for heterogeneity using the Cochran Q test. If significant heterogeneity was present (P< 0.10), data from the studies was not combined and the studies were examined for possible explanations. If there was no significant heterogeneity, a combined odds ratio was calculated using a fixed effects model and a Z test was performed to test the overall effect. Reoperation for patellofemoral problems was significantly more likely in the unresurfaced group (p=0.003). The overall rate for reoperation for a patellofemoral problem was 0.7% in the resurfaced group and 12% in the unresurfaced group. Study data on clinical knee scores and anterior knee pain could not be analysed together as there was significant heterogeneity. There was no difference between the two groups in terms of revision. This study found no mid- to long-term benefit to leaving the patella unresurfaced.

The choice of graft for anterior cruciate ligament reconstruction remains controversial. A systematic review was performed to compare bone-patella tendon-bone and 4-strand hamstring grafts. Medline (1966 onwards), EMBASE (1980 onwards) and the Cochrane database were searched retrieving 6312 possible articles but only 6 studies fulfilled all the inclusion criteria. To be included, the study had to be prospective, randomised or quasirandomised, comparing 4SHS and central third BPTB autografts, inserted using an arthroscopically assisted technique and have a minimum 2-year follow up for all patients. These studies recruited 526 patients and 475 were followed for at least 2 years with 235 patients receiving a bone-patella tendon-bone graft and 240 receiving a 4-strand hamstring graft. Overall, there was a greater chance of extension loss (p=0.007) and a trend towards increased patellofemoral joint pain (p=0.09) with a patella tendon graft. With a 4-strand hamstring graft there is a greater loss of hamstring power (p=0.008) and a trend towards an increased chance of a pivot shift > 1 (p=0.12). There was no difference between the 2 groups in terms of lachman testing, chance of returning to the same level of sport, clinical knee scores, graft ruptures or other complications.

Aims: In this study, data from previously published survival analysis life tables of primary total condylar type TKRs has been combined to enable comparison of different design features. In particular, does posterior stabilisation or metal backing of the tibial component improve the longevity of primary cemented þxed bearing condylar type TKRs?Methods: To be included, the article had to give 5 or more years results of a primary cemented þxed bearing condylar type TKRs including a survival analysis life table. Series performed on a selected patient group (for example young age, elderly or rheumatoid arthritis) were excluded to reduce possible bias. When 2 series of the same implant from the same institution were available, the most recent article with the longest follow up was used. Results: Survival analysis data from 16 papers (5950 knees) was combined to compare design features. There was no difference in survival between posterior stabilised implants and those that were not or between metal-backed and all-polyethylene tibial components. Those all-polyethylene tibial components that were not stabilised had signiþcantly better survival than metal-backed, non stabilised tibial components and posterior stabilised, metalbacked components (p< 0.05) but not posterior stabilised, all-polyethylene components. Conclusions: Using the currently available literature, posterior stabilisation or metal backing of the tibial component does not improve the longevity of primary cemented þxed bearing condylar type TKRs.