Radiological assessment of total and unicompartmental knee replacement remains an essential part of routine care and follow-up. Appreciation of the various measurements that can be identified radiologically is important. It is likely that routine plain radiographs will continue to be used, although there has been a trend towards using newer technologies such as CT, especially in a failing knee, where it provides more detailed information, albeit with a higher radiation exposure.

The purpose of this paper is to outline the radiological parameters used to evaluate knee replacements, describe how these are measured or classified, and review the current literature to determine their efficacy where possible.

AIM

Failure of a primary anterior cruciate ligament (ACL) reconstruction is associated with poor functional outcomes even after revision surgery. The aim of this study is to identify early predictors for failure, so that it may aid in recognition of at-risk patients.

Aim

To evaluate the results and complications of bone transport in the treatment of massive tibial bone defects, using the Ilizarov method.

Introduction

Unicondylar knee replacements (UKR) may be more effective compared to Total knee replacements (TKR) in unicompartmental arthritis. We report patient outcomes & satisfaction data in an age matched cohort of patients with either a UKR or TKR.

Purpose: Pinch strength has been shown to be a predictor of the ability to grip objects and perform functional hand-related tasks. As the sole flexor of the thumb IP joint, the flexor pollicus longus (FPL) muscle has previously been shown to play an essential role in directing thumb tip force as well as contribute to overall pinch strength. The relative contribution of FPL to pinch strength is unknown however. As the FPL may be affected in several acute and chronic conditions, determining the contribution of FPL to pinch strength may be useful in planning as well as evaluating treatment options. The purpose of this study was to estimate the contribution of FPL to pinch strength in-vivo using an EMG-guided, selective motor blockade, test-retest protocol.

Method: 11 healthy volunteers were recruited to participate in the study. All participants completed a brief questionnaire regarding prior hand injuries and subsequently underwent a physical examination to assess baseline hand function. Baseline pinch strength was recorded using three different pinch techniques: key pinch, 3-point chuck grasp, and tip pinch. Participants then underwent EMG-guided lidocaine blockade of the FPL muscle. Motor evoked potentials as well as skin potentials were used to confirm adequate FPL blockade. The physical exam was repeated as were pinch strength measurements. Post block splinting was necessary to stabilize the thumb IP joint. Grip strength, in addition to clinical examination, was utilized pre and post block to assess for inadvertent blockade of other muscle groups or nerves. A final clinical evaluation was conducted at study completion to note any complications or adverse effects.

Results: All three types of pinch strength showed a significant difference between pre and post measurements (p< 0.01). The mean differences pre and post were 9.7N,6.4N, and 5.2N in key, 3-point chuck, and tip pinch respectively (p< 0.01). The relative contribution of FPL for each pinch type was 53.2%,39.5%, and 44.3%. EMG, motor evoked potentials, and skin potentials confirmed adequate paralysis of the FPL. Physical examination did reveal decreased sensation in median and radial nerve distributions in some individuals, however the effect on observed motor function was negligible. Grip strength decreased by only 4N post blockade confirming no clinically significant median nerve motor blockade. The protocol was well tolerated and no serious complications were noted.

Conclusion: Using an in-vivo model we were able to estimate the contribution of FPL to overall pinch strength. In our study, FPL’s contribution to pinch strength was estimated to be 9.7N,6.4N, and 5.2N in key, 3-point chuck, and tip pinch respectively (p< 0.01). The relative contribution of FPL for each pinch type was 53.2%, 39.5%, and 44.3%. Inherent limitations in study design may have tended to overestimate the contribution of FPL to pinch. This information may be useful in planning and evaluating treatments for acute and chronic conditions affecting FPL function.

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.

Introduction: Rupture of the anterior cruciate ligament (ACL) is a serious injury associated with symptomatic instability of the knee. There is an increasing trend for confirmation of diagnosis with magnetic resonance imaging (MRI) before proceeding to reconstruction. The overall sensitivity and specificity of diagnosis using this modality is more than 95%. It is however observer-dependent. We have developed a simple 4 point recognition card to increase the pick-up rate of this injury for professionals without specific radiological training such as orthopaedic trainees. The aim of this study was to determine how much improvement could be achieved using this card and whether any change was sustained.

Methods: 20 participants (orthopaedic trainees surgeons and medical students) were shown 20 MRI scans of the knee (10 with complete ACL ruptures and 10 with normal ACLs) and asked which scans were demonstrative of ACL pathology. Each participant was then randomly allocated to either having verbal teaching in the standard fashion about detection of ACL injuries [Group 1] or given written cards detailing a 4 point recognition plan for recognising ACL injuries on MRI [Group 2]. A repeat test of MRI scans was performed on each participant immediately after the teaching session and at 3 weeks.

Results: The mean time taken to teach Group A was 14 mins and Group B was 11 mins (p < 0.05). The mean number of correct diagnoses was 2.7/10 in Group A and 3.1/10 in Group B pre-intervention (p > 0.05). Immediately following intervention, there were 6.1 correct diagnoses in Group A and 8.2 in Group B (p < 0.05). At 3 weeks, there were 3.4 correct diagnoses in Group A and 7.9 in Group B (p < 0.05). The difference in number of correct diagnoses at 3 weeks compared to immediately following intervention was significant in Group A (p < 0.05), but not in Group B (p > 0.05).

Conclusions: The results support the use of the 4 point recognition card as to tool for increasing the pick-up of ACL injuries on MRI. It offers advantages over standard teaching Methods: since it takes less time to teach and the necessary information is retained to a greater degree than with traditional teaching methods.

Introduction: The bearing surface of total hip arthroplasty (THA) is a key factor in implant survivorship. Ceramic bearings have enhanced wear properties though are prone to fracture and thus Oxinium has been developed as an alternative. The aim of our study was to compare the its wear properties against cobalt-chrome which is currently the most widely used femoral head bearing surface in THA.

Methods: We prospectively randomized 270 consecutive patients undergoing THA at one institution into three groups: Groups I, II and III. Group I received a cobalt-chrome femoral head and cross-linked poly-ethylene (XLPE) liner; Group II received an oxinium femoral head and ultrahigh molecular weight polyeth-ylene (UHMWPE) liner; Group III received an oxinium femoral head and cross-linked polyethylene liner. 32 mm heads were used in all the cases. Patients were longitidunally followed up with clinical evaluation and standardised radiographs of the pelvis and hip. Using DICOMeasure software, we calculated the linear and volumetric wear rate for each group to determine if a difference existed.

Results: The demographics and comorbid conditions were similar between the groups. The survivorship of all components was 100% in all groups at 2 years. No patients were lost to follow-up. After the first 6 months of creep, the rate of linear wear over 2 years was 0.16mm for Group I, 0.10mm for Group II, and 0.06mm for Group III. ANOVA testing demonstrates statistical significance between the groups (P < 0.05).

Discussion and Conclusion: Our results demonstrate that the wear rate using 32mm Oxinium heads is significantly lower than that for cobalt-chrome heads and this effect is dramatically enhanced when used in combination with highly cross linked polyethylene.

Bacterial infection in orthopaedic surgery can be devastating, and is associated with significant morbidity and poor functional outcomes, which may be improved if high concentrations of antibiotics can be delivered locally over a prolonged period of time. The two most widely used methods of doing this involve antibiotic-loaded polymethylmethacrylate or collagen fleece. The former is not biodegradable and is a surface upon which secondary bacterial infection may occur. Consequently, it has to be removed once treatment has finished. The latter has been used successfully as an adjunct to systemic antibiotics, but cannot effect a sustained release that would allow it to be used on its own, thereby avoiding systemic toxicity.

This review explores the newer biodegradable carrier systems which are currently in the experimental phase of development and which may prove to be more effective in the treatment of osteomyelitis.

Fibrin glue, also known as fibrin sealant, is now established as a haemostatic agent in surgery, but its role in orthopaedic surgery is neither well known nor clearly defined. Although it was originally used over 100 years ago, concerns about transmission of disease meant that it fell from favour. It is also available as a slow-release drug delivery system and as a substrate for cellular growth and tissue engineering. Consequently, it has the potential to be used in a number of ways in orthopaedic surgery. The purpose of this review is to address its use in surgery of the knee in which it appears to offer great promise.

Purpose: To determine if a multi-modal programme including non-operative measures of physiotherapy and education can improve the symptoms of osteoarthritis of the knee.

Methods/Results: 72 patients with osteoarthritis of the knee confirmed on radiographic or arthroscopic evidence were referred over a 13 month period (April 2007 – May 2008) for a lower limb programme. The programme consisted of 12 classes over 6 weeks of group physiotherapy and included education on osteoarthritis, diet and exercise.

The total number of knees affected was 98. The mean number of compartments affected was 1.2 with the medial and patellofemoral compartment most affected. The mean number of classes attended was 8.3. Pre-intervention, the mean WOMAC score was 64.7 and the mean Oxford knee score was 31.9. Post-intervention at a mean follow up of 12 months (range 7 – 22 months), the mean WOMAC score was 29.4 and the mean Oxford knee score 22.4. The change in scores following intervention was statistically significant (p < 0.05). Of the cohort, 9 patients were subsequently offered or went on to have knee joint arthroplasty.

Conclusions: At 12 months, a multi-modal programme consisting of non-operative interventions has an excellent impact upon osteoarthritis of the knee with improved patient reported scores. This modality should be considered for all patients with mild to moderate osteoarthritis in whom surgical options are not otherwise indicated. Further work is required to see which components most influenced patients’ outcomes, the impact of education and group classes on maintaining physiotherapy exercises in the long term, the benefits conferred even for those patients who subsequently undergo joint arthroplasty, and whether referral to the programme from a primary care setting will lower the number of referrals of knee osteoarthritis to orthopaedic units which are ultimately managed without surgical intervention.

Aim: To ascertain if a medial rotation platform knee replacement design (MRK; Finsbury Orthopaedics) exhibits improved range of motion (ROM) and functional outcome compared to a conventional single radius condylar knee replacement system (PFC Sigma; Depuy) at one year.

Methods: Eighty patients undergoing total knee arthroplasty(TKA) were prospectively randomised and allocated to either receive the MRK or PFC Sigma pros-thesis. Patients were blinded to the choice of implant. Follow-up clinical and radiological evaluations were carried out by a single clinician so as to avoid interob-server error. Validated patient based scores including the Total Knee Function Questionnaire (TKFQ) were used to assess patient function.

Results: The average ROM in the MRK group was 108.53°. In the PFC Sigma group it was 94.16°. Statistical significance was demonstrated between the two groups.

The MRK group showed superior results in the TKFQ score which assesses activities of daily living as well as recreational and sporting activities. The movement and lifestyle component of the TKFQ, and the Knee Society Score were better in the MRK group with statistical significance.

No difference was demonstrated between the two groups with respect to radiological analysis, WOMAC Knee, Oxford Knee and SF-36 scores.

6 out of 40 patients in the MRK group compared to 5 out of 40 patients in the PFC group said that they had forgotten about their TKA at one year.

Conclusions: The medial rotation platform design confers increased ROM at one year with an associated benefit in movement and lifestyle and resultant patient satisfaction.

Anterior Cruciate Ligament (ACL) reconstruction is a well established procedure for restoration of stability following ACL rupture. Several methods exist for fixation of soft tissue grafts on the tibia, without general agreement about the optimal method. This study compared two different methods of tibial fixation using hamstring grafts in ACL reconstruction.

113 consecutive patients were randomized into two groups at the time of surgery. In group one, fixation was with a metal interference screw (RCI) and staples and in group two, with a polyethylene screw and sheath (Intrafix). Evaluation of outcomes was conducted using KT-1000 arthrometer, Lysholm, IKDC subjective and Mohtadi scores.

7 reinjuries occurred within the time frame of the study, mostly related to sporting injuries, with 5 in group 2. 81% of remaining participants were successfully followed at 2 years post surgery. No significant difference in mean KT-1000 side-to-side measurements was found between groups at an average follow-up of 30 months (1.5 ± 1.9mm and 1.8 ± 1.9mm, respectively; p > 0.05). The mean Lysholm score for group one was 65.2 ± 15.5 preoperatively and 90.8 ± 9.5 postoperatively; for group two these scores were 62.0 ± 20.7 preoperatively and 88.8 ± 14.3 postoperatively. This improvement in scores after surgery was similar for both groups and was not significantly different between groups (p > 0.05). Both the IKDC subjective and Mohtadi scores showed significant (p < 0.05) improvements postoperatively compared with pre-operatively but no significant difference between fixation groups.

There were no significant differences between the two groups for any outcome value, with both methods of graft fixation producing good results. The newer Intra-fix device had a higher reinjury rate but this was not significantly different from the screw and staple fixation, and on all other outcome measures the Intrafix device was equivalent to an interference screw and staples for tibial-sided graft fixation in ACL reconstruction.

Multi-ligament knee injuries require complex surgery. Hinged external fixators propose to control the tibio-femoral relationship, protect reconstructions and allow early mobilisation. However, a uniaxial hinge may be too simplistic for such a complex joint. We investigated the influence of an external fixation device on ligament strains and joint contact forces.

Six fresh frozen cadaveric lower limbs (41–56 years old) were obtained. Displacement transducers (Microstrain, USA) were attached to mid-substance lateral (LCL) and medial collateral (MCL) ligaments, and the anterior and posterior cruciate (PCL) ligaments through minimal soft tissue incisions. Joint pressures were measured by transducers (Tekscan) introduced in the medial and lateral compartments through small sub-meniscal arthrotomies. Flouroscopic imaging was used to construct the hinged fixator centred over the epicondylar axis. Ligament tensile strains and joint contact forces were determined through a passive arc of 20 to 110 degrees of flexion and extension, with and without the external fixator (ExFix^™, EBI Biomet Australia).

The application of the external fixation device resulted in minimal change in the mean peak percentage strain of the PCL, MCL and ACL ligaments, while the LCL peak percentage strain decreased. Generally the peak percentage strain for each ligament occurred at or near the same flexion angle in both the un-instrumented and instrumented case within each limb, but the peak percentage strain flexion angles varied significantly across limbs. Peak joint contact forces increased significantly (p < 0.05) in the lateral compartment after attachment of the external fixation device. There was no difference seen in the medial compartment joint contact forces.

This study shows that a uniaxial hinged external fixator can be used in a multi-ligament reconstructed knee to maintain joint congruence and allow early postoperative rang of motion without compromising the results of reconstructions or repairs.

BACKGROUND: With the improvement of the ultrasound technology, there has been an increasing ability to image the soft tissues of the hand and wrist. This means structures such as tendon, ligaments and soft tissues can be visualized both statically and dynamically.

AIM: The aim of our study was to audit the types of cases who have undergone ultrasound imaging in different hand conditions in last two years.

MATERIAL AND METHODS: We studied 123 ultrasound and looked for its use in different hand and wrist conditions. These were categorized in different groups such as diagnostic, anatomical and therapeutical.

RESULTS: In our 123 patients, 49 had lumps out of which 30 ganglions, 7 vascular, 4 glomus tumours, 2 granulomas, 4 neuromas, 1 lipomas and 1 sarcoma. In another 30 patients it was useful to diagnose tendon conditions such as inflammation, rupture, triggering. Furthermore, in 31 patients it was used for diagnosis of carpal tunnel syndrome. In addition, it was used for many miscellaneous conditions.

DISCUSSION: Ultrasound is a useful tool for imaging of soft tissues in the hand. It can differentiate between solid and cystic swellings and can be used to aspirate and / or inject the later. It allows dynamic viewing thus making it an important tool in assessing complex tendon problems. We feel that it is a convenient, dependable and useful aid in diagnosing various hand conditions and should be available for widespread use.

i. Purpose To determine whether operating in ultra-clean vertical laminar flow and personal isolation “space suits” reduces deep infection rates in total knee replacement compared to a conventional theatre and modern disposal gowns.

ii. Method An analysis of deep infection rates in 373 patients who underwent total knee arthroplasty performed in one operating theatre prior to and after a theatre and clothing upgrade.

Results The infection rate before the introduction of ultraclean air and space suits was 6/166 (3.6%). Afterwards the rate was 1/207 (0.5%). This shows a significant reduction (p< 0.05)

iii. Conclusion Compared to conventional theatres and clothing the use of ultraclean vertical laminar flow and spacesuits significantly reduces the risk of infection in total knee arthroplasty.

Objective: To compare the presentation, diagnosis and treatment of spinal tuberculosis in two cities, one in the UK, and one in Malaysia

Design: Retrospective comparison over a five-year period from June 1995. The Centres studied were the Royal Orthopaedic and Queen Elizabeth Hospitals, Birmingham (UK), and the Kuala Lumpur General Hospital (KL), Malaysia.

Subjects: There were 80 patients (29 females, mean age 42) in the KL group, and 19 patients (8 females, mean age 45) in the UK group.

Outcome measures: Frankel grading before and after treatment were measured for both groups.

Results: KL patients had higher rates of immunocompromise, and had fewer spinal levels involved, 2.1 compared with 2.6 (p-−0.04). There were 65 procedures, 58 positive ZN stains, and 65 positive cultures as compared with 24, 2 and 9 in Birmingham respectively. Improvement in Frankel grading was seen in four patients in UK (5 grades), and in 17 patients in KL (29 grades).

Conclusions: Although the two groups exhibited similar demographics, the rate of immunocompromise-related tuberculosis, severity of neurological deficit, and type of surgery undertaken differed significantly. Reasons for the difficulty in identifying the tubercle bacillus in Birmingham are discussed.