Abstract. Introduction. Coronal plane alignment of the knee (CPAK) classification utilises the native arithmetic hip-knee alignment to calculate the constitutional limb alignment and joint line obliquity which is important in pre-operative planning. The objective of this study was to compare the accuracy and reproducibility of measuring the lower limb constitutional alignment with the traditional long leg radiographs versus computed tomography (CT) used for pre-operative planning in robotic-arm assisted TKA. Methods. Digital long leg radiographs and pre-operative CT scan plans of 42 patients (46 knees) with osteoarthritis undergoing robotic-arm assisted total knee replacement were analysed. The constitutional alignment was established by measuring the medial proximal tibial angle (mPTA), lateral distal femoral angle (LDFA), weight bearing hip knee alignment (WBHKA), arithmetic hip knee alignment (aHKA) and joint line obliquity (JLO). Furthermore, the Coronal Plane Alignment of the Knee (CPAK) classification was utilised to classify the patients based on their coronal knee alignment phenotype. Results. Mean age of the patients was 66 years (SD 9) and mean BMI 31.2 (SD 3.9). There were 27 left and 19 right sided surgeries. The Pearson's corelation coefficient was 0.722 (p=0.008) for WBHKA; 0.729 (p<0.001) for MPTA; 0.618 (p=0.14) for aHKA; 0.502 (p= 0.04) for LDFA and 0.305 (p=0.234) for JLO. CPAK classification was concordant for 53% study participants between the two groups. Conclusion. Three-dimensional CT-based modelling with computer software more accurately predicts constitutional limb alignment and JLO as defined by the CPAK classification compared to plain long-leg radiographs in pre-operative planning of total knee arthroplasty

Abstract. Objectives. To determine the effectiveness of LIA compared to ACB in providing pain relief and reducing opiates usage in hamstring graft ACL reconstructions. Materials and Methods. In a consecutive series of hamstring graft ACL reconstructions, patients received three different regional and/or anaesthetic techniques for pain relief. Three groups were studied: group 1: general anaesthetic (GA)+ ACB (n=38); group 2: GA + ACB + LIA (n=31) and group 3: GA+LIA (n=36). ACB was given under ultrasound guidance. LIA involved infiltration at skin incision site, capsule, periosteum and in the hamstring harvest tunnel. Analgesic medications were similar between the three groups as per standard multimodal analgesia (MMA). Patients were similar in demographics distribution and surgical technique. The postoperative pain and total morphine requirements were evaluated and recorded. The postoperative pain was assessed using the visual analogue scores (VAS) at 0hrs, 2hrs, 4hrs, weight bearing (WB) and discharge (DC). Results. There was no statistically significant difference in opiates intake amongst the three groups. When comparing VAS scores; there were no statistical difference between the groups at any of the time intervals that VAS was measured. However, the GA+LIA group hospital's LOS (m=2.31hrs, SD=0.75) was almost half that of GA+ACB group (m=4.24hrs, SD=1.08); (conditions t(72)=8.88; p=0.000). There was no statistical significance in the incidence of adverse effects amongst the groups. Conclusion. The LIA technique provided equally good pain relief following hamstring graft ACL reconstructions when compared to ACB, while allowing for earlier rehabilitation, mobilisation and discharge

Aims. The primary objective of this study was to compare migration of the cemented ATTUNE fixed bearing cruciate retaining tibial component with the cemented Press-Fit Condylar (PFC)-sigma fixed bearing cruciate retaining tibial component. The secondary objectives included comparing clinical and radiological outcomes and Patient Reported Outcome Measures (PROMs). Methods. A single blinded randomized, non-inferiority study was conducted including 74 patients. Radiostereometry examinations were made after weight bearing, but before hospital discharge, and at three, six, 12, and 24 months postoperatively. PROMS were collected preoperatively and at three, six, 12, and 24 months postoperatively. Radiographs for measuring radiolucencies were collected at two weeks and two years postoperatively. Results. The overall migration (mean maximum total point motion (MPTM)) at two years was comparable: mean 1.13 mm (95% confidence interval (CI), 0.97 to 1.30) for the ATTUNE and 1.16 mm (95% CI, 0.99 to 1.35) for the PFC-sigma. At two years, the mean backward tilting was -0.43° (95% CI, -0.65 to -0.21) for the ATTUNE and 0.08° (95% CI -0.16 to 0.31), for the PFC-sigma. Overall migration between the first and second postoperative year was negligible for both components. The clinical outcomes and PROMs improved compared with preoperative scores and were not different between groups. Radiolucencies at the implant-cement interface were mainly seen below the medial baseplate: 17% in the ATTUNE and 3% in the PFC-sigma at two weeks, and at two years 42% and 9% respectively (p = 0.001). Conclusion. In the first two postoperative years the initial version of the ATTUNE tibial component was not inferior with respect to overall migration, although it showed relatively more backwards tilting and radiolucent lines at the implant-cement interface than the PFC-sigma. The version of the ATTUNE tibial component examined in this study has subsequently undergone modification by the manufacturer. Level of Evidence: 1 (randomized controlled clinical trial). Cite this article: Bone Joint J 2020;102-B(9):1158–1166

The outcome and survivorship of osteotomy for medial compartment osteoarthritis are closely correlated to the changes in the weight bearing axis. Questions remain over the optimal correction when undertaking medial unicompartmental knee replacement (UKR). Prospective data was collected on 50 patients (30F:20M) undergoing fixed bearing medial UKR which included pre-operative and 12 month Oxford Knee Scores and pre and post-operative weight-bearing long-leg radiographs. The weight bearing axis was measured from the centre of the femoral head to the mid-point of the talus. The point at which this axis crossed the tibial plateau was expressed as a percentage of the width of that plateau - 0 (medial cortex) to 100% (lateral cortex). Regression method and correlation coefficients were used to assess the relationship between the response and variables. A significant correlation was seen between the 12 month score and the change in axis, which was maintained when the pre-operative score was adjusted for (p = 0.043 and 0.046 respectively). Larger changes in scores were seen with larger changes in axis (p = 0.046) when the pre-operative axis was adjusted for. Higher BMIs reported worse scores at 12 months (p = 0.022) and a smaller overall change in score one year post-operatively (p = 0.037). This significance was improved when the pre-operative scores were adjusted (p = 0.017 and 0.017 respectively). Proximity of correction of axis to the assumed contralateral normal was weakly correlated (p = 0.049) to the 12 month score, especially when BMI was corrected for. These results suggest that the weight bearing axis and BMI do play a significant role in early patient outcomes following fixed bearing unicompartmental knee replacement

Aim. To determine the tensile forces across the knee extensor mechanism during walking, in simulated conditions of treatment. Methods. Gait analysis of six normal subjects was performed, with full weight bearing unilateral immobilisation of the knee during walking. Measurements were taken without then with a brace, unlocked then locked at 0°, 0-10°, 0-20° and 0-30° of flexion. Mean and maximum knee flexion angles were measured, followed by calculation of the mean and maximum forces across the extensor mechanism during loading, supporting and propulsion phases of gait. Results. The knee brace flexion angles set were consistently different to those measured kinematically, although the brace did act appropriately to restrict flexion. The highest flexion angles were found during the propulsion phase of gait. The calculated force through the extensor mechanism was greatest during the loading phase. The highest force recorded was with the brace locked between 0-10° of flexion, which in a 70kg person would be equivalent to a mean load of 343 N with a peak of 890 N. Discussion. The maximum forces for all conditions measured in our study exceed those published in the literature for failure strength of many common fixation devices. We recommend that full weight bearing during walking should be avoided in the injured limb, after the initial repair of the knee extensor mechanism

Introduction. Enhanced pain and rehabilitation protocols have significantly improved patient recovery following primary TKR. Little has been written on how the protocols have affected the revision TKR patient. We report on a matched group of revision and primary TKR patients treated with the identical pain and rehab program. Materials and Methods. 40 aseptic RTKR patients who underwent a full femoral and tibial revision were matched by age, sex, and BMI to a group of patients who underwent a cemented tri-compartmental primary TKR. All revision knees had uncemented stemmed femurs and tibias. All 40 patients had either a metaphyseal sleeve on either the femur or tibia or both. Patients in both groups were treated with an identical post op pain protocol (Spinal anesthetic, local infiltrative analgesia and multimodal oral pain management along with rapid rehabilitation). All patients were mobilized on POD1 and allowed weight bearing as tolerated. Patients were followed for a minimum of 1 year. KSS at 6 weeks and 1 year were recorded for both groups. Results. There was no significant difference in length of stay between the RTKR and the primary TKR (1.2 days versus 1.1 days). Average oral morphine equivalents used during the hospitalization was 38 for the RTKR and 42 for the primary group. There was 1 readmission in each group: GI distress in the RTKR and urinary retention in the primary group. There no were reoperations, wound healing problems, identified thromboembolic events or manipulations under anesthesia in either group. KSS for the RTKR group averaged 87.3 at 6 weeks (range 45 to 99) and 89.1at minimum 1 year (range 52 to100). KSS for the primary group averaged 89.9 (range 71 to 100) at 6 week follow-up and 93.2 (range 54 to 100) at minimum follow-up. Range of motion at final follow up averaged1.2 (0–10) to 114.1 (55–135) for the RTKR group and 1 (0–8) to 121.3 (85–140) for the primary group. Conclusion. Despite more complex surgery in the revision total knee patient, enhanced pain and rehabilitation protocols have enabled the RTKR patient to have a similar recovery and outcome compared to the primary TKR patient. For figures, tables, or references, please contact authors directly

The dysplastic Trochlear is a developmental condition characterised by an abnormally flat or dome-shaped trochlea and it is recognised as a significant cause of patella instability, with the increased sulcus angle being is the most common finding. Surgical correction of the shape of the Trochlear Groove is frequently performed. The described methods in the literature involve open arthrotomy to normalise and maintain the trochlear morphology achieving normal alignment and tracking of the patella. Open procedures carries a significant risk of arthrofibrosis. The technique was developed in human cadaveric knees at the Donjoy Clinical Education and Research Facility (CERF) in Vista California. We describe an arthroscopic procedure to create a neo-trochlea using gouges, spherical and conical hooded burrs. We studied prospectively a series of 4 consecutive patients with patello-femoral instability secondary to trochlear dysplasia, who were treated by an Arthroscopic trochleoplasty by a single surgeon between 2007 and 2008. Postoperatively the patients were rehabilitated in accordance with our routine Patello-Femoral microfracture Protocol, allowing weight bearing and ROM 0-20 degrees in a long lever brace for 6 weeks. CT scanning at one year showed a complete neo-cortex and cartilage sequenced MRI at 12 months showed complete fill with fibro cartilage. Pre- and post-operative scores (KOOS, Kujala) were assessed by the patients and a satisfaction questionnaire was completed. The results showed a statistical improvement in the outcome at the 2 year follow up. Overall, patients (100%) were satisfied with the outcome of their procedure and there have been no adverse events. To our knowledge this technique has not been described before in the English literature and the early results of arthroscopic trochleoplasty are encouraging and offer an alternative to open approaches. Larger numbers and longer follow ups are needed to confirm the long term benefit

PURPOSE OF STUDY. Periprosthetic fractures after total knee arthroplasty is a potentially serious and challenging complication and the incidence is continuously rising. The purpose of this study was to analyse the prevalence and analyse effectiveness of the various treatment methods for management of periprosthetic fracture of the distal femur after total knee arthroplasty, and to determine the clinical and radiographic results of patients following surgical treatment of these injuries. METHODS. We reviewed all patients with periprosthetic fractures after total knee arthroplasty treated surgically between 2003 and 2008 from the prospective hospital database. Medical and radiographic records were reviewed for patient characteristics, fracture characteristics, implant details, healing, and complications. Antero-posterior and lateral radiographs were reviewed at the time of admission, post-operatively and at follow up visits. Fractures were classified according to the Lewis and Rorabeck, Orthopaedic Trauma Association and the methods of Su and DeWal. RESULTS. 26 patients (average age= 77.6) had operative management for displaced fractures. Mechanical fall was the commonest mode of injury at a mean of 4.66 years post primary replacement. Locking plates was the commonest method of fixation for stable implant and displaced fractures [Lewis & Rorabeck type 2] and 2 patients had distal femoral replacements for unstable implants. Successful fracture healing within 6 months occurred in all but one patient. Full weight bearing mobilisation was achieved at 3 months in 94% and patients with distal femoral replacements achieved quickest recovery. CONCLUSIONS. Compared to the current literature, we had a satisfactory outcome in following individualised treatment of periprosthetic fractures after knee joint replacement. Periprosthetic femoral fractures around the knee commonly constitute a challenging problem and require an adequate analysis of fracture etiology and distal femoral replacement achieves satisfactory results in fractures with unstable implants

Background. The management of chondral lesions in the knee, especially in young fit patients, remains an area of considerable controversy. Articular cartilage repair or reconstruction techniques may offer these patients alternatives to arthroplasty or realignment osteotomy. The TruFit plug (Smith & Nephew, London, UK) is a synthetic biphasic polymer scaffold that is designed for implantation at the site of a focal chondral defect. It is intended to resorb and allow tissue ingrowth 6-9 months following implantation and may be placed either arthroscopically or via an open approach depending on the site of the lesion. Methods. 11 patients with focal chondral defects in the knee underwent TruFit plug implantation. Postoperative management entailed a period of 6 weeks of restricted weight bearing or restricted knee flexion according to implantation site. Radiological evaluation with MRI or CT arthrogram (or both) was conducted at various time points postoperatively according to clinical indication. Functional scoring with the Oxford knee score (OKS), Tegner activity scale and Lysholm score were completed. Results. 35 TruFit plugs were implanted in 12 knees of 11 patients (4 men, 7 women) between June 2007 and December 2009. Mean age at time of surgery 46.9 years (range32-72years). Mean change in OKS 1.33 (range -13 to 29), Lysholm 13.8 (range -19 to 61), Tegner 0.33 (range -2 to 2 levels). Imaging characteristics on MRI and CT arthrogram show delayed incorporation of the grafts in all patients with no osseous integration at up to 24 months follow up. Conclusions. Early results from the TruFit plug show variable functional outcome scores which appear independent of patient age, number of plugs used and site of implantation. All show delayed tissue integration. Our group is currently not implanting any further TruFit plugs pending longer term outcomes from larger case series

Introduction. Patients with knee osteoarthritis frequently complain that they develop pain in other joints due to over-loading during gait. However, there have been no previous studies examining the effect of knee arthritis on the other weight bearing joints. The aim of this study was to examine the loading of the hips and contra-lateral knee during gait in a cohort of patients pre- and post knee replacement. Methods. Twenty patients with single joint osteoarthritis awaiting knee replacement and 20 healthy volunteers were recruited. Gait analysis during level gait and at self selected speed was performed using a 12 camera Vicon motion analysis system. The ground reaction force was collected using EMG electrodes attached to the medial and lateral hamstrings and quadriceps bilaterally. Patients were invited to return 12 months post-operatively. Data was analysed using the Vicon plug-in-gait model and statistical testing was performed with SPSS v16.0 using ANCOVA to account for gait speed. Results. The mean age of the patients was 69 (range 53-82) and the controls was 70 (range 60-83). Mid-stance moments and knee adduction impulses were elevated at both hips and both knees in patients compared to normal individuals (Impulses: OA Knee=1.87Nms; opposite knee=1.46Nms; controls=0.86Nms; p<0.01) whilst peak moments were not significantly different. Muscular co-contraction was elevated in both knees compared to normal (p<0.01). Ten patients returned for follow up. Correction of varus resulted in improvements in moments at the replaced knee however recovery of moments in the other joints was variable and dependant on alignment, gait speed and their ability to mobilise their centre of mass. Conclusion. Patients with single joint knee osteoarthritis have abnormal loading of both knees and both hips, potentially leading to further disease and disability. Recovery following knee replacement is variable and dependant on limb alignment and the patient's functional recovery

The aim of this study was to determine current practice in anterior cruciate ligament reconstruction amongst BASK members. This was an internet-based survey where members were invited to complete a questionnaire on ACL reconstruction. Of the 365 BASK surgeons performing ACL reconstruction, 241 completed the questionnaire (response rate 66%). 147(61%) of surgeons used both hamstring and patellar tendon grafts, 71(29%) used only hamstrings and 21(9%) used patellar tendon only. All surgeons used ipsilateral autograft. 157 (65%) used the transtibial technique for femoral tunnel placement with 80(33%) using the anteromedial portal technique. Of those using the anteromedial portal, the most common femoral fixation devices were the Endobutton (34%) and RCI screw (34%). Interference screw fixation (81%) was the most common tibial fixation in the same group of surgeons with the RCI screw being the most common (63%). 19% (45/241) of surgeons were performing double bundle ACL reconstructions in select cases. Hamstring femoral fixation was with a suspension device in 79% and interference screw in 18%. Of those using a suspension device the Endobutton was most common (48%) followed by Transfix (26%) and Rigidfix (19%). Tibial fixation was most commonly achieved by interference screw (57%) followed by Intrafix (30%). With patellar tendon graft the most popular femoral fixation was with an interference screw (66%) followed by suspension (34%). All surgeons used interference screw for tibial fixation. 90% of surgeons (217) allow immediate full weight-bearing as tolerated irrespective of fixation type with 8% delaying full weight bearing between 1 and 3 weeks. The results show the wide spread of variation in practice of ACL reconstruction. With recent renewed interest in a more anatomic placement of tunnels, the use of the anteromedial portal may continue to increase. With such a wide variation in techniques, grafts and fixation implants used, a register may help assess outcomes

Statement of Purpose. The UK and Australian clinical experience of an implantable load absorber was reviewed for knee OA patients who have exhausted conservative care, but are not ideal candidates for HTO or arthroplasty due to age, activity level, obesity, or disinclination. Methods and Results. The load absorber was implanted in 58 patients, with the longest duration exceeding two years. Patients included younger OA sufferers (31-68 years), and had a mean BMI > 30kg/m. 2. Early surgical experience and adverse events with the device were recorded and clinical outcomes using validated patient reported outcomes tools were collected at baseline, post-op, 2 and 6 weeks, and 3, 6, 12 and 24 month timepoints. All patients were successfully implanted with a mean surgical time of 76.4 minutes (range 54-153). After a mean hospital stay of 1.7 days (range 1-3), patients resumed full weight bearing within 1-2 weeks and achieved normal range of motion by 6 weeks. Mean WOMAC pain (0-100 scale) improved from 42.4 to 16.1 (p<0.001); mean WOMAC function (0-100 scale) improved from 42.0 to 14.7 (p<0.001). Most patients reported “no or mild” pain (85%) or “no or mild” functional impairment (90%) at last follow-up (9.5 ± 3.5 months). Patients reported high satisfaction with the implant. Initial UK results mirror the positive Australian experience: reduced pain, improved function, and high satisfaction. Complications arising in the early surgical experience were effectively resolved through revised surgical technique and minor design modifications. Conclusions. The initial UK experience with the load absorber is consistent with the positive Australian experience. The load absorber preserves natural knee anatomy and kinematics whilst providing durable pain relief and resumption of high activity levels. This device, with these early encouraging results, can fill a major void in the treatment options for young and active OA patients

Aims

The aim of this prospective multicentre study was to describe trends in length of stay and early complications and readmissions following unicompartmental knee arthroplasty (UKA) performed at eight different centres in Denmark using a fast-track protocol and to compare the length of stay between centres with high and low utilization of UKA.

Aims

Total knee arthroplasty is an established treatment for knee osteoarthritis with excellent long-term results, but there remains controversy about the role of uncemented prostheses. We present the long-term results of a randomized trial comparing an uncemented tantalum metal tibial component with a conventional cemented component of the same implant design.

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To report mid- to long-term results of Oxford mobile bearing domed lateral unicompartmental knee arthroplasty (UKA), and determine the effect of potential contraindications on outcome.

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The aim of this study was to examine whether tourniquet use can improve perioperative blood loss, early function recovery, and pain after primary total knee arthroplasty (TKA) in the setting of multiple-dose intravenous tranexamic acid.

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The treatment of patients with allergies to metal in total joint arthroplasty is an ongoing debate. Possibilities include the use of hypoallergenic prostheses, as well as the use of standard cobalt-chromium (CoCr) alloy. This non-designer study was performed to evaluate the clinical outcome and survival rates of unicondylar knee arthroplasty (UKA) using a standard CoCr alloy in patients reporting signs of a hypersensitivity to metal.

Aim

It has been suggested that the use of a pilot-hole may reduce the risk of fracture to the lateral cortex. Therefore the purpose of this study was to determine the effect of a pilot hole on the strains and occurrence of fractures at the lateral cortex during the opening of a high tibial osteotomy (HTO) and post-surgery loading.

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Knee joint distraction (KJD) is a relatively new, knee-joint preserving procedure with the goal of delaying total knee arthroplasty (TKA) in young and middle-aged patients. We present a randomised controlled trial comparing the two.

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Oxidised zirconium was introduced as a material for femoral components in total knee arthroplasty (TKA) as an attempt to reduce polyethylene wear. However, the long-term survival of this component is not known.