Research priorities of members of the British Association for Surgery of the Knee.

Aims: This study aims to identify the top unanswered research priorities in the field of knee surgery using consensus-based methodology. Methods: Initial research questions were generated using an online survey sent to all 680 members of the British Association for Surgery of the Knee (BASK). Duplicates were removed and a longlist was generated from this scoping exercise by a panel of 13 experts from across the UK who provided oversight of the process. A modified Delphi process was used to refine the questions and determine a final list. To rank the final list of questions, each question was scored between one (low importance) and ten (high importance) in order to produce the final list. Results: This consensus exercise took place between December 2020 and April 2022. A total of 286 clinicians from the BASK membership provided input for the initial scoping exercise, which generated a list of 105 distinct research questions. Following review and prioritization, a longlist of 51 questions was sent out for two rounds of the Delphi process. A total of 42 clinicians responded to the first round and 24 responded to the second round. A final list of 24 research questions was then ranked by 36 clinicians. The topics included arthroplasty, infection, meniscus, osteotomy, patellofemoral, cartilage, and ligament pathologies. The management of early osteoarthritis was the highest-ranking question. Conclusion: A Delphi exercise involving the BASK membership has identified the future research priorities in knee surgery. This list of questions will allow clinicians, researchers, and funders to collaborate in order to deliver high-quality research in knee surgery and further advance the care provided to patients with knee pathology.

Revision total knee replacement finances: a detailed cost-analysis of operative practice at a regional tertiary referral centre.

BACKGROUND: The revision knee complexity classification (RKCC) stratifies knee revision operations depending on their level of complexity from simple revisions (R1) to highly complex cases (R3). Current financial codes used for calculation of reimbursement for knee revision services provided at the Trust, rely on patients' comorbidities. However, previous research has demonstrated that this approach may not yield an accurate financial account of knee revision arthroplasty cost. This is a single centre study from a secondary and tertiary revision unit, with work previously presented by the authors demonstrating that the majority of complex revision knee replacement within the region, take place in this unit. The aims of this study were to illustrate the current cost profile and renumeration service currently in place for revision knee and show the differences in cost based on complexity of the operation. METHODS: In this retrospective study, 90 cases who underwent revision knee operations in 2019 were analysed. Data was obtained from a tertiary referral centre where the episodes had occurred. Mean cost, tariff, and subsequent deficit were calculated for the R1, R2 and R3 episodes. RESULTS: R2 and R3 episodes were significantly more expensive than R1 episodes. The increase in cost between R3 and R2 episodes was not significant. The total cost of the revision operations was £1,162,343. Tariffs received for R2 and R3 revision operations were significantly more expensive than R1 operations. However, the increase in tariffs received for R3 operations was not significant in relation to R2 operations. The total amount of tariffs received by the Trust was £ 770,996 generating a net deficit of - £ 391,347. CONCLUSION: Current financial coding for revision knee does not accurately predict costs associated with revision knee surgery. Net deficit varies depending on the RKCC grade of the knee revision episode with more complex operations resulting in a higher mean net deficit. Implementation of the RKCC could prove to be a useful tool in generating an accurate prediction of the cost associated with knee revision surgery.

Robotic Arthroplasty Clinical and cost Effectiveness Randomised controlled trial (RACER-knee): a study protocol.

INTRODUCTION: Robotic-assisted knee replacement systems have been introduced to healthcare services worldwide in an effort to improve clinical outcomes for people, although high-quality evidence that they are clinically, or cost-effective remains sparse. Robotic-arm systems may improve surgical accuracy and could contribute to reduced pain, improved function and lower overall cost of total knee replacement (TKR) surgery. However, TKR with conventional instruments may be just as effective and may be quicker and cheaper. There is a need for a robust evaluation of this technology, including cost-effectiveness analyses using both within-trial and modelling approaches. This trial will compare robotic-assisted against conventional TKR to provide high-quality evidence on whether robotic-assisted knee replacement is beneficial to patients and cost-effective for healthcare systems. METHODS AND ANALYSIS: The Robotic Arthroplasty Clinical and cost Effectiveness Randomised controlled trial-Knee is a multicentre, participant-assessor blinded, randomised controlled trial to evaluate the clinical and cost-effectiveness of robotic-assisted TKR compared with TKR using conventional instruments. A total of 332 participants will be randomised (1:1) to provide 90% power for a 12-point difference in the primary outcome measure; the Forgotten Joint Score at 12 months postrandomisation. Allocation concealment will be achieved using computer-based randomisation performed on the day of surgery and methods for blinding will include sham incisions for marker clusters and blinded operation notes. The primary analysis will adhere to the intention-to-treat principle. Results will be reported in line with the Consolidated Standards of Reporting Trials statement. A parallel study will collect data on the learning effects associated with robotic-arm systems. ETHICS AND DISSEMINATION: The trial has been approved by an ethics committee for patient participation (East Midlands-Nottingham 2 Research Ethics Committee, 29 July 2020. NRES number: 20/EM/0159). All results from the study will be disseminated using peer-reviewed publications, presentations at international conferences, lay summaries and social media as appropriate. TRIAL REGISTRATION NUMBER: ISRCTN27624068.

Gap balanced adjusted mechanical alignment versus measured resection mechanical alignment: a randomised controlled trial.

INTRODUCTION: Alignment goals in total knee replacement (TKR) is a topical subject. This study compares the short-term functional outcomes and patient reported outcome measures (PROMs) of two philosophies for knee arthroplasty alignment: measured resection (MR) and an individualised alignment philosophy, with the tibia mechanically aligned and an instrumented gap balancer (GB) to align the femur in both flexion and extension. PATIENTS AND METHODS: 94 knees were enrolled in this randomised controlled trial. The surgical protocol used a MR technique for mechanical alignment or a GB technique for individualised alignment. Primary outcome was quadriceps strength. Secondary outcomes included validated functional tests and PROMs as well as patient satisfaction. Outcomes were assessed pre-operatively, at 6 weeks, 3, 6 and 12 months post-operatively. RESULTS: At 12-month follow-up, there was no significant difference in the change from baseline mean quadriceps peak torque between the two groups (p = 0.988). Significant improvement in the change in range of motion (ROM) in the GB group compared to the MR group at 3 months (13° vs 6° p = 0.028) but this improvement was not significant at 1 year (20° vs 17° p = 0.21). The functional test of balance showed statistically significant improvement at 6 weeks (p = 0.03) in the GB group but this difference was not maintained. PROMs favoured the GB group, with the KOOS pain scoring statistically better (p ≤ 0.05) at 6 weeks, 3, 6 and 12 months. CONCLUSIONS: Individualised alignment philosophy utilising a GB technique did not demonstrate an improvement in the primary outcome measure quadriceps peak torque. Improvement was seen in the GB group in PROM pain scores that was significant, both statistically and clinically, out to at least 1 year. Gains that were seen in functional assessment with GB, although significant at some time points, were no longer significant at 1 year and no difference was seen in quads strength. Compared to a MR technique, the individualised GB technique appears to confer some improvement in pain, ROM and some functional tests following TKR in the short-term.

Robotic Assisted Patellofemoral Joint Replacement: Surgical Technique, Tips and Tricks.

In this article we wish to provide MAKO robotic knee users a surgical guide including tips and tricks on performing MAKO robotic-assisted patellofemoral joint replacements. The senior authors in this paper from the Exeter Knee Reconstruction Unit, United Kingdom are highly experienced MAKO users who have been performing MAKO assisted Patellofemoral joint replacements since 2017.

The biomechanics of metaphyseal cone augmentation in revision knee replacement.

The demand for revision knee replacement (RKR) has increased dramatically with rising patient life expectancy and younger recipients for primary TKR. However, significant challenges to RKR arise from osseous defects, reduced bone quality, potential bone volume loss from implant removal and the need to achieve implant stability. This study utilizes the outcomes of an ongoing RKR clinical trial using porous metaphyseal cones 3D-printed of titanium, to investigate 1) bone mineral density (BMD) changes in three fixation zones (epiphysis, metaphysis, and diaphysis) over a year and 2) the biomechanical effects of the cones at 6 months post-surgery. It combines dual-energy x-ray absorptiometry (DXA), computed tomography (CT) with patient-specific based finite element (FE) modelling. Bone loss (-0.086 ± 0.05 g/cm2) was found in most patients over the first year. The biomechanical assessment considered four different loading scenarios from standing, walking on a flat surface, and walking downstairs, to a simulated impact of the knee. The patient-specific FE models showed that the cones marginally improved the strain distribution in the bone and shared the induced load but played a limited role in reducing the risks of bone fracture or cement debonding. This technique of obtaining real live data from a randomized clinical trial and inserting it into an in-silico FE model is unique and innovative in RKR research. The tibia RKR biomechanics examined open up further possibilities, allowing the in-silico testing of prototypes and implant combinations without putting patients at risk as per the recommended IDEAL framework standards. This process with further improvements could allow rapid innovation, optimization of implant design, and improve surgical planning.

The STAR care pathway for patients with pain at 3 months after total knee replacement: a multicentre, pragmatic, randomised, controlled trial.

BACKGROUND: Approximately 20% of people experience chronic pain after total knee replacement, but effective treatments are not available. We aimed to evaluate the clinical effectiveness and cost-effectiveness of a new care pathway for chronic pain after total knee replacement. METHODS: We did an unmasked, parallel group, pragmatic, superiority, randomised, controlled trial at eight UK National Health Service (NHS) hospitals. People with chronic pain at 3 months after total knee replacement surgery were randomly assigned (2:1) to the Support and Treatment After Replacement (STAR) care pathway plus usual care, or to usual care alone. The STAR intervention aimed to identify underlying causes of chronic pain and enable onward referrals for targeted treatment through a 3-month post-surgery assessment with an extended scope practitioner and telephone follow-up over 12 months. Co-primary outcomes were self-reported pain severity and pain interference in the replaced knee, assessed with the Brief Pain Inventory (BPI) pain severity and interference scales at 12 months (scored 0-10, best to worst) and analysed on an as-randomised basis. Resource use, collected from electronic hospital records and participants, was valued with UK reference costs. Quality-adjusted life-years (QALYs) were calculated from EQ-5D-5L responses. This trial is registered with ISRCTN, ISRCTN92545361. FINDINGS: Between Sept 6, 2016, and May 31, 2019, 363 participants were randomly assigned to receive the intervention plus usual care (n=242) or to receive usual care alone (n=121). Participants had a median age of 67 years (IQR 61 to 73), 217 (60%) of 363 were female, and 335 (92%) were White. 313 (86%) patients provided follow-up data at 12 months after randomisation (213 assigned to the intervention plus usual care and 100 assigned to usual care alone). At 12 months, the mean between-group difference in the BPI severity score was -0·65 (95% CI -1·17 to -0·13; p=0·014) and the mean between-group difference in the BPI interference score was -0·68 (-1·29 to -0·08; p=0·026), both favouring the intervention. From an NHS and personal social services perspective, the intervention was cost-effective (greater improvement with lower cost), with an incremental net monetary benefit of £1256 (95% CI 164 to 2348) at £20 000 per QALY threshold. One adverse reaction of participant distress was reported in the intervention group. INTERPRETATION: STAR is a clinically effective and cost-effective intervention to improve pain outcomes over 1 year for people with chronic pain at 3 months after total knee replacement surgery. FUNDING: National Institute for Health Research.

Robotic-Assisted Patellofemoral Replacement-Correlation of Preoperative Planning with Intraoperative Implant Position and Early Clinical Experience: A Minimum 2-Year Follow-up.

Patello-femoral arthroplasty (PFA) is successful in a selected group of patients and yields a good functional outcome. Robotic-assisted knee arthroplasty has been shown to provide better implant positioning and alignment. We aim to report our early outcomes and to compare Mako's (Robotic Arm Interactive Orthopaedic System [RIO]) preoperative implant planning position to our intraoperative PFA implant position. Data for this study was prospectively collected for 23 (two bilateral) patients who underwent robotic-assisted PFA between April 2017 and May 2018. All preoperative implant position planning and postoperative actual implant position were recorded. Presence of trochlear dysplasia and functional outcome scores were also collected. There were 17 (two bilateral) female and 6 male patients with a mean age of 66.5 (range: 41-89) years. The mean follow-up period was 30 (range: 24-37) months. Eighteen knees (72%) had evidence of trochlear dysplasia. The anterior trochlear line was on average, 7.71 (range: 3.3-11.3) degrees, internally rotated to the surgical transepicondylar axis and on average 2.9 (range: 0.2-6.5) degrees internally rotated to the posterior condylar line. The preoperative planning range was 4-degree internal to 4-degree external rotation, 4-degree varus to 6-degree valgus, and 7-degree flexion to 3-degree extension. The average difference between preoperative planning and intraoperative implant position was 0.43 degrees for rotation (r = 0.93), 0.99 degrees for varus/valgus (r = 0.29), 1.26 degrees for flexion/extension (r = 0.83), and 0.34 mm for proudness (r = 0.80). Six patients (24%) had a different size component from their preoperative plan (r = 0.98). The mean preoperative Oxford Knee Score (OKS) was 16 and the mean postoperative OKS was 42. No patient had implant-related revision surgery or any radiological evidence of implant loosening at final follow-up. Our early results of robotic PFA are promising. Preoperative Mako planning correlates closely with intraoperative implant positioning. Longer follow-up is needed to assess long-term patient outcomes and implant survivorship.

Prosthetic joint infection of the knee - arthroscopic biopsy identifies more and different organisms than aspiration alone.

BACKGROUND: Prosthetic joint infection (PJI) causes significant morbidity and mortality following knee replacement surgery. Identifying causative organisms and antibiotic sensitivities is critical in increasing the chance of infection eradication. This study investigated whether biopsy alone was superior to aspiration alone for serological diagnosis in PJI following knee replacement. Secondly, we investigated whether biopsy identifies the same or new/different microbiological flora as aspiration. METHODS: Since December 2014, the Exeter Knee Reconstruction Unit (EKRU) has prospectively collated data regarding all PJIs referred from our local/regional network which have been reviewed via our Multi-Disciplinary Team (MDT). We identified and included consecutive patients from this MDT from Dec.2014-Mar.2020 and analysed their electronic records. Statistical analysis was performed using Stata. RESULTS: 65/100 patients studied had both pre-operative aspiration and biopsy. 31/65 (48%) had positive aspiration and biopsies. No aspirate samples were positive with corresponding biopsies negative. In 19/65 (29%) of infection positive patients, biopsy identified new (7) or additional (12) organisms not identified by aspiration. Aspiration had a sensitivity of 70%, specificity of 88%, positive predictive value of 90.3% and negative predictive value of 64.7%. Biopsy had a sensitivity of 97.5%, specificity of 88%, positive predictive value of 92.9% and negative predictive value of 95.7%. CONCLUSION: In 29% of confirmed PJI cases, arthroscopic biopsy identified either additional organisms in a polymicrobial PJI when compared to aspiration, or new positive results when aspiration alone was negative. This study demonstrates the benefits of arthroscopic biopsy for serological diagnosis in cases of knee PJI and aids treatment planning.

Personalised high tibial osteotomy has mechanical safety equivalent to generic device in a case-control in silico clinical trial.

Background: Despite favourable outcomes relatively few surgeons offer high tibial osteotomy (HTO) as a treatment option for early knee osteoarthritis, mainly due to the difficulty of achieving planned correction and reported soft tissue irritation around the plate used to stablise the osteotomy. To compare the mechanical safety of a new personalised 3D printed high tibial osteotomy (HTO) device, created to overcome these issues, with an existing generic device, a case-control in silico virtual clinical trial was conducted. Methods: Twenty-eight knee osteoarthritis patients underwent computed tomography (CT) scanning to create a virtual cohort; the cohort was duplicated to form two arms, Generic and Personalised, on which virtual HTO was performed. Finite element analysis was performed to calculate the stresses in the plates arising from simulated physiological activities at three healing stages. The odds ratio indicative of the relative risk of fatigue failure of the HTO plates between the personalised and generic arms was obtained from a multi-level logistic model. Results: Here we show, at 12 weeks post-surgery, the odds ratio indicative of the relative risk of fatigue failure was 0.14 (95%CI 0.01 to 2.73, p = 0.20). Conclusions: This novel (to the best of our knowledge) in silico trial, comparing the mechanical safety of a new personalised 3D printed high tibial osteotomy device with an existing generic device, shows that there is no increased risk of failure for the new personalised design compared to the existing generic commonly used device. Personalised high tibial osteotomy can overcome the main technical barriers for this type of surgery, our findings support the case for using this technology for treating early knee osteoarthritis.

Personalised high tibial osteotomy has mechanical safety equivalent to generic device in a case-control in silico clinical trial.

BACKGROUND: Despite favourable outcomes relatively few surgeons offer high tibial osteotomy (HTO) as a treatment option for early knee osteoarthritis, mainly due to the difficulty of achieving planned correction and reported soft tissue irritation around the plate used to stablise the osteotomy. To compare the mechanical safety of a new personalised 3D printed high tibial osteotomy (HTO) device, created to overcome these issues, with an existing generic device, a case-control in silico virtual clinical trial was conducted. METHODS: Twenty-eight knee osteoarthritis patients underwent computed tomography (CT) scanning to create a virtual cohort; the cohort was duplicated to form two arms, Generic and Personalised, on which virtual HTO was performed. Finite element analysis was performed to calculate the stresses in the plates arising from simulated physiological activities at three healing stages. The odds ratio indicative of the relative risk of fatigue failure of the HTO plates between the personalised and generic arms was obtained from a multi-level logistic model. RESULTS: Here we show, at 12 weeks post-surgery, the odds ratio indicative of the relative risk of fatigue failure was 0.14 (95%CI 0.01 to 2.73, p = 0.20). CONCLUSIONS: This novel (to the best of our knowledge) in silico trial, comparing the mechanical safety of a new personalised 3D printed high tibial osteotomy device with an existing generic device, shows that there is no increased risk of failure for the new personalised design compared to the existing generic commonly used device. Personalised high tibial osteotomy can overcome the main technical barriers for this type of surgery, our findings support the case for using this technology for treating early knee osteoarthritis.

Surgical treatment to realign the knee, called a high tibial osteotomy, is effective at relieving symptoms of knee osteoarthritis but the operation is difficult. A new personalised treatment with simpler surgery has been designed. The aim of this study was to investigate the safety of the new personalised treatment compared to the standard treatment. For the first time, a detailed computer simulation clinical trial was performed, using imaging data from 28 real patients. The computer simulation compared the risk of the implant failure between the personalised and standard treatments. The personalised treatment did not have a higher risk of implant failure than standard treatment. This supports further clinical studies looking at the benefits of personalised over standard realignment surgery. The personalised treatment has the potential to allow much more widespread use of realignment surgery to treat early knee osteoarthritis.

Top ten research priorities for problematic knee arthroplasty.

AIMS: The James Lind Alliance aims to bring patients, carers, and clinicians together to identify uncertainties regarding care. A Priority Setting Partnership was established by the British Association for Surgery of the Knee in conjunction with the James Lind Alliance to identify research priorities related to the assessment, management, and rehabilitation of patients with persistent symptoms after knee arthroplasty. METHODS: The project was conducted using the James Lind Alliance protocol. A steering group was convened including patients, surgeons, anaesthetists, nurses, physiotherapists, and researchers. Partner organizations were recruited. A survey was conducted on a national scale through which patients, carers, and healthcare professionals submitted key unanswered questions relating to problematic knee arthroplasties. These were analyzed, aggregated, and synthesized into summary questions and the relevant evidence was checked. After confirming that these were not answered in the current literature, 32 questions were taken forward to an interim prioritization survey. Data from this survey informed a shortlist taken to a final consensus meeting. RESULTS: A total of 769 questions were received during the initial survey with national reach across the UK. These were refined into 32 unique questions by an independent information specialist. The interim prioritization survey was completed by 201 respondents and 25 questions were taken to a final consensus group meeting between patients, carers, and healthcare professionals. Consensus was reached for ranking the top ten questions for publication and dissemination. CONCLUSIONS: The top ten research priorities focused on pain, infection, stiffness, health service configuration, surgical and non-surgical management strategies, and outcome measures. This list will guide funders and help focus research efforts within the knee arthroplasty community. Cite this article: Bone Joint J 2020;102-B(9):1176-1182.

Urgent Arthroplasty Interventions During the COVID-19 Pandemic: Operating Risks in Low-Prevalence Areas.

Background and objective Orthopaedic services have reorganised their delivery of care in response to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. In this study, we aimed to share our operating experience during the coronavirus disease 2019 (COVID-19) pandemic and analyse its effect on urgent hip and knee arthroplasty. Our study involved a comparative analysis between a cohort of patients from 2019 (pre-COVID) and another from 2020. Methods Tha data relating to patients undergoing urgent operations requiring arthroplasty interventions such as for infection, periprosthetic fracture (PPF) and neck of femur fracture (NOF) between April and July of 2020 and 2019 were reviewed prospectively and retrospectively. Patients were categorised according to the Royal College of Surgeons (RCS) case prioritisation and the COVID-19 risk assessment. Data were collected on 30-day mortality, readmissions, reoperations, complications, length of hospital stay and theatre efficiency. This was analysed, matched and compared. Statistical analysis was performed on categorical variables including the time to the theatre as well as dual consultant operating. Results A total of 46 consecutive patients were included in the 2020 cohort with a mean age of 78 years (range: 58-108 years). The median length of stay was 6.5 days (range: 3-35 days) and the median time to theatre for NOF patients was 23.8 hours (range: 16.2-87.7 hours). There were six complications and two deaths; one of the deaths was COVID-19-related. A total of 56 patients were included from 2019 with a mean age of 74.6 years (range: 45-88 years). The median length of stay was five days (range: 1-18 days) and the median time to theatre for NOF patients was 40.8 hours (range: 18.9-167 hours). There were four complications and one death. Conclusion Based on our findings, it is safe to perform complex surgery in a region of low community prevalence of COVID-19, and the outcomes were comparable to those from a pre-COVID-19 cohort.

Ten-year results for a single-surgeon series of Scorpio non-restrictive geometry (NRG) posterior stabilised (PS) total knee replacement.

BACKGROUND: To report the long-term results for a single-surgeon consecutive series of Scorpio non-restrictive geometry (NRG) posterior stabilised (PS) total knee replacement (TKR). MATERIALS AND METHODS: Forty-six consecutive patients who underwent 53 Scorpio NRG PS were identified. Change in range of motion (ROM) and Oxford Knee Score (OKS) over time were recorded. Radiographs were evaluated for alignment and radiolucent lines. Survival analysis for the prosthesis was calculated. RESULTS: At a mean of 10.1 years (range 9.1-10.9) following exclusions thirty-seven (69.8%) knees in thirty-one (67.4%) patients (6 bilateral) were available for review. None of the patients required revision surgery. Mean OKS score at 10 years was 37.8. The mean ROM significantly improved from 95° pre-operative to 117.5° at 5 years and 115° at 10 years (p = < 0.001). This equates to a value-added range of motion (VAROM) of 19° at 5 years and 15.6° at 10 years. There was a correlation between OKS and VAROM at 5 and 10 years. Radiological assessment did not reveal any evidence of progressive cement radiolucent lines nor component migration. CONCLUSION: In this series the Scorpio NRG PS showed 100% 10-year survivorship. We found a significant improvement in ROM and VAROM over time. This was not associated with increased signs of loosening.

Collagen reorganization in cartilage under strain probed by polarization sensitive second harmonic generation microscopy.

Type II collagen fibril diameters in cartilage are beneath the diffraction limit of optical microscopy, which makes the assessment of collagen organization very challenging. In this work we use polarization sensitive second harmonic generation (P-SHG) imaging to map collagen organization in articular cartilage, addressing in particular its behaviour under strain and changes which occur in osteoarthritis. P-SHG yields two parameters, molecular order and orientation, which provide measures of the degree of organization both at the molecular scale (below the diffraction limit) and above a few hundred nanometres (at the image pixel size). P-SHG clearly demonstrates the zonal collagen architecture and reveals differences in the structure of the fibrils around chondrocytes. P-SHG also reveals sub-micron scale fibril re-organization in cartilage strips exposed to tensile loading, with an increase in local organization in the superficial zone which weakly correlates with tensile modulus. Finally, P-SHG is used to investigate osteoarthritic cartilage from total knee replacement surgery, and reveals widespread heterogeneity across samples both microscale fibril orientations and their sub-micron organization. By addressing collagen fibril structure on scales intermediate between conventional light and electron microscopy, this study provides new insights into collagen micromechanics and mechanisms of degradation.

Three-phase Technetium-99m bone scanning in patients with pain in the knee region after cemented total knee arthroplasty.

INTRODUCTION: Our aim was to question the usefulness of a three-phase bone scan in the evaluation of pain in the knee region after TKR. Our hypothesis was that an abnormal investigation had a poor association with the presence of infection or loosening, and did not provide any additional diagnostic information above that already available through other standard investigations. METHODS: A retrospective study over a 24-month period was performed comprising 118 patients investigated with a TPBS. Investigations were summarised and analysed, and were classified as entirely normal, possibly abnormal, and definitely abnormal. RESULTS: Thirty-three per cent (39/118) of TPBSs were reported as being entirely normal, 59% (69/118) as possibly abnormal, and 8% (10/118) as definitely abnormal. During the 24-month study period, 131 revision TKR procedures were performed at our institution; 9% (12/131) were investigated with TPBS and 91% (119/131) were not. No patient with an entirely normal pre-operative TPBS underwent revision TKR surgery. Eighty-five per cent (67/79) with an abnormal TPBS were managed conservatively. In our series, a TPBS had a positive predictive value of 2.53%, a negative predictive value of 100%, with an overall accuracy of 34.75% with 100% sensitivity (97.5% one-sided confidence interval 0-24.71%), and 33.62% specificity (95% confidence interval 53.29-72.37%), in the diagnosis of infection, or loosening with concurrent infection in determining the indication for revision surgery. CONCLUSION: A TPBS should only be considered following clinical evaluation, serological investigation, diagnostic imaging, and microbiological analysis of fluid obtained from arthrocentesis by a specialist revision arthroplasty surgeon. A TPBS may be useful in the situation where abnormal serology is present, but where repeated joint aspirations samples are inconclusive.

Vibration therapy versus standard treatment for tennis elbow: A randomized controlled study.

AIM: To determine whether a mechanical, high-frequency vibration device (Tenease™) can improve pain and function for the treatment of tennis elbow (TE), compared with standard treatment. METHODS: Adults presenting to an elbow clinic with a clinical diagnosis of TE were randomized to standard treatment with physiotherapy, activity modification and analgesia or standard treatment plus Tenease therapy. Tenease therapy consisted of a 6-week period of treatment using the Tenease device with three 10-min episodes each day. The primary outcome measure was the quick Disabilities of the Arm, Shoulder and Hand score at 6 months, with scores also taken at 6 weeks. Secondary outcome measures were the Patient Rated Tennis Elbow Evaluation Score and EuroQol 5-Dimension Visual Analogue Scale at the same time points. RESULTS: Fifty-four patients were recruited into the study. Following randomization and initial dropout, 18 patients were included in the standard group and 27 in the Tenease group. Both groups reported improvements in primary outcome measure scores. The control group had a mean score of 44.3 (standard deviation (SD) = 18.8) at baseline, which dropped to 31.2 (SD = 17.2) at 6 months ( p = 0.002). The Tenease group had a mean score of 43.2 (SD = 22.7) at baseline, which dropped to 23.4 (SD = 15.0) at 6 months ( p = 0.064). Similar improvements were seen in secondary outcome measures with none reaching statistical significance. There were no statistically significant differences seen between the primary outcome scores at 6 weeks ( p = 0.9) or 6 months ( p = 0.5). No complications were noted in either group. CONCLUSIONS: Vibration therapy did not result in any statistically significant improvement in functional outcome scores compared to standard treatment for TE. It is important to note that this was a relatively small cohort and a high dropout rate was observed.

Three Cases of Femoral Stem Failure in Rotating Hinge Revision Total Knee Arthroplasty: Causes and Surgical Considerations.

Catastrophic failure of stemmed components in arthroplasty is an uncommon but a serious complication. Stem fractures and techniques for addressing these have been described following hip arthroplasty but much less so following total knee arthroplasty (TKA). We review three cases of catastrophic failure of the stem in rotating hinge revision TKA prostheses. We discuss the possible mechanism of failure and review the current literature addressing this topic. Metaphyseal support needs to be optimized in order to minimize load transfer to the stem and to the junction (and the risk of fracture) if a modular component is used. When constrained components are used, radiographs need to be carefully assessed for signs of proximal loosening. Nonmodular stems are also an option in this situation.