Aims. To map literature on prognostic factors related to outcomes of revision total knee arthroplasty (rTKA), to identify extensively studied factors and to guide future research into what domains need further exploration. Methods. We performed a systematic literature search in MEDLINE, Embase, and Web of Science. The search string included multiple synonyms of the following keywords: "revision TKA", "outcome" and "prognostic factor". We searched for studies assessing the association between at least one prognostic factor and at least one outcome measure after rTKA surgery. Data on sample size, study design, prognostic factors, outcomes, and the direction of the association was extracted and included in an evidence map. Results. After screening of 5,660 articles, we included 166 studies reporting prognostic factors for outcomes after rTKA, with a median sample size of 319 patients (30 to 303,867). Overall, 50% of the studies reported prospectively collected data, and 61% of the studies were performed in a single centre. In some studies, multiple associations were reported; 180 different prognostic factors were reported in these studies. The three most frequently studied prognostic factors were reason for revision (213 times), sex (125 times), and BMI (117 times). Studies focusing on functional scores and patient-reported outcome measures as prognostic factor for the outcome after surgery were limited (n = 42). The studies reported 154 different outcomes. The most commonly reported outcomes after rTKA were: re-revision (155 times), readmission (88 times), and reinfection (85 times). Only five studies included costs as outcome. Conclusion. Outcomes and prognostic factors that are routinely registered as part of clinical practice (e.g. BMI, sex, complications) or in (inter)national registries are studied frequently. Studies on prognostic factors, such as functional and sociodemographic status, and outcomes as healthcare costs, cognitive and mental function, and psychosocial impact are scarce, while they have been shown to be important for patients with osteoarthritis. Cite this article: Bone Jt Open 2023;4(5):338–356

Abstract. Introduction. Challenges in surgical training have led to the exploration of technologies such as augmented reality (AR), which present novel approaches to teaching orthopaedic procedures to medical students. The aim of this double-blinded randomised-controlled trial was to compare the validity and training effect of AR to traditional teaching on medical students’ understanding of total knee arthroplasty (TKA). Methodology. Twenty medical students from 7 UK universities were randomised equally to either intervention or control groups. The control received a consultant-led teaching session and the intervention received training via Microsoft HoloLens, where surgeons were able to project virtual information over physical objects. Participants completed written knowledge and practical exams which were assessed by 2 orthopaedic consultants. Training superiority was established via 4 quantitative outcome measures: OSATS scores, a checklist of TKA-specific steps, procedural time, and written exam scores. Qualitative feedback was evaluated using a 5-point Likert scale. Results. AR training was superior in teaching basic technical proficiency and understanding of TKA, with the intervention group significantly outperforming the control group in 3 metrics [OSATS (38.6%, p=0.021), checklist (33%, p=0.011) and written exam (54.5%, p=0.001)]. Procedural time was equivalent between cohorts (p=0.082). AR was rated as significantly more enjoyable (p=0.044), realistic (p=0.003), easy to understand (p=0.040), and proficient in teaching (p=0.02). Conclusion. In this adequately powered, double-blinded randomised-controlled trial, AR training demonstrated substantially improved translational technical skills and knowledge needed to understand TKA over traditional learning in medical students. Additionally, the results showed face, content, and transfer validity for AR in surgical training

Aims

The rate of day-case total knee arthroplasty (TKA) in the UK is currently approximately 0.5%. Reducing length of stay allows orthopaedic providers to improve efficiency, increase operative throughput, and tackle the rising demand for joint arthroplasty surgery and the COVID-19-related backlog. Here, we report safe delivery of day-case TKA in an NHS trust via inpatient wards with no additional resources.

Aims

To explore the efficacy of extracorporeal shockwave therapy (ESWT) in the treatment of osteochondral defect (OCD), and its effects on the levels of transforming growth factor (TGF)-β, bone morphogenetic protein (BMP)-2, -3, -4, -5, and -7 in terms of cartilage and bone regeneration.

Aims

To assess the cost-effectiveness of a two-layer compression bandage versus a standard wool and crepe bandage following total knee arthroplasty, using patient-level data from the Knee Replacement Bandage Study (KReBS).

Aim. We aim to compare revision rates and functional outcome scores in between two contemporary total knee arthoplasty systems. Methods. A search was carried out of a prospectively maintained outcomes database to identify all patients receiving total knee replacement (TKR) in the department between 2005 and 2006, when evaluation of different knee arthroplasty systems was being undertaken. Data on the first 93 consecutive patients receiving a Scorpio (Stryker, Allendale, NJ) implant and the first 93 consecutively receiving a PFC (DePuy, Warsaw, IN) implant were reviewed. Four year revision rates and functional scores were recorded. Results. Patient demographics were similar in both groups. Six of ninety three Scorpio implants were listed for revision over the four year period (6%). Five of these were for aseptic loosening. Three further patients are currently being investigated for pain and have radiological evidence of loosening with no clinical evidence of infection. No PFC implants required revision in the four year period (p = 0.013). There was no difference in Oxford Scores pre-operatively, or at 3 months, 1 year and 2 years post-operatively. Discussion. There is a significant difference in revision rates between the two prostheses, and the revision rate of the Scorpio prosthesis is far higher than would be expected. The majority of these have been revised for aseptic loosening. Those prostheses surviving to four years had similar clinical outcomes. The reasons for this higher than expected revision rate in the Scorpio group require further exploration

Aims

The optimal management of an infrapopliteal deep venous thrombosis (IDVT) following total knee arthroplasty (TKA) remains unknown. The risk of DVT propagation and symptom progression must be balanced against potential haemorrhagic complications associated with administration of anticoagulation therapy. The current study reports on a cohort of patients diagnosed with IDVT following TKA who were treated with aspirin, followed closely for development of symptoms, and scanned with ultrasound to determine resolution of IDVT.

Aims

To describe the risk of periprosthetic joint infection (PJI) and reoperation in patients who have an acute, traumatic wound dehiscence following total knee arthroplasty (TKA).

Purpose. To study the initial presentation and subsequent investigation and management of acute knee dislocations at a regional trauma centre. Introduction. Knee dislocation requires high energy trauma, and often affects young working adults. The high incidence of associated arterial, neurological, ligamentous, and other soft tissue injuries, can produce potentially devastating outcomes. Rapid mobilisation of traditionally distinct surgical teams, with urgent vascular imaging and emergency surgery are often necessary. The extent and severity of ligamentous damage may require multiple operations to repair. Methods. A retrospective nine-year study of knee dislocations managed in the Trauma and Orthopaedic Department of the Royal Hospitals, Belfast was performed using a Fractures Outcomes Research Database (FORD), a chart review, and a review of relevant radiology. Demographic data, mechanisms of injury, associated neurovascular injuries, ligamentous damage, and operative intervention were recorded. Results. 15 patients were identified over 9 years (2000-2008 inclusive). Mean age at injury was 38 years, median 37. 14 (93%) of patients were male, 1 (7%) was female. 6 injuries (40%) were sport-related, 3 (20%) occurred as a result of road traffic collisions, 5 (33%) were accidents in the workplace, and 1 (7%) was a result of a fall while intoxicated with alcohol. 5 (33%) patients experienced a common peroneal nerve palsy. 10 (67%) received vascular imaging, and 2 (13%) underwent vascular surgery as part of the initial theatre episode. All 15 dislocations led to some degree of structural soft tissue knee injuries. These included 12 (80%) anterior cruciate ligaments, 8 (53%) posterior cruciate ligaments, 7 (47%) lateral collateral ligaments, and 5 (33%) medial collateral ligaments. 3 posterolateral corner injuries required repair. Of the 15 patients, 2 (13%) underwent no operative procedures following closed reduction, and the remaining 13 patients had 21 distinct theatre episodes recorded between them. 2 fasciotomies for compartment syndrome, and 2 common peroneal nerve decompression/explorations were performed in the initial theatre episode. 3 patients (20%) were managed with an external fixator initially. 1 patient (7%) developed complications and required trans-femoral amputation. Conclusions. Knee dislocation remains uncommon, and even major centres may receive only a few injuries per year. Orthopaedic, Vascular and Plastic surgeons, as well as Emergency Physicians and Radiologists must remain vigilant to the challenge which this injury can present, and the opportunity for excellent outcomes through a coordinated approach with close communication, awareness of injury patterns, and availability of theatre and imaging resources

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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.

Aims

The morphometry of the distal femur was largely studied to improve bone-implant fit in total knee arthroplasty (TKA), but little is known about the asymmetry of the posterior condyles. This study aimed to investigate the dimensions of the posterior condyles and the influence of externally rotating the femoral component on potential prosthetic overhang or under-coverage.

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The aim of this to study was to compare the previously unreported long-term survival outcome of the Oxford medial unicompartmental knee arthroplasty (UKA) performed by trainee surgeons and consultants.

Aims

The aim of this consensus was to develop a definition of post-operative fibrosis of the knee.

This prospective study reports the 15-year survival and ten-year functional outcome of a consecutive series of 1000 minimally invasive Phase 3 Oxford medial UKAs (818 patients, 393 men, 48%, 425 women, 52%, mean age 66 years; 32 to 88). These were implanted by two surgeons involved with the design of the prosthesis to treat anteromedial osteoarthritis and spontaneous osteonecrosis of the knee, which are recommended indications. Patients were prospectively identified and followed up independently for a mean of 10.3 years (5.3 to 16.6).

At ten years, the mean Oxford Knee Score was 40 (standard deviation (sd) 9; 2 to 48): 79% of knees (349) had an excellent or good outcome. There were 52 implant-related re-operations at a mean of 5.5 years (0.2 to 14.7). The most common reasons for re-operation were arthritis in the lateral compartment (2.5%, 25 knees), bearing dislocation (0.7%, seven knees) and unexplained pain (0.7%, seven knees). When all implant-related re-operations were considered as failures, the ten-year rate of survival was 94% (95% confidence interval (CI) 92 to 96) and the 15-year survival rate 91% (CI 83 to 98). When failure of the implant was the endpoint the 15-year survival was 99% (CI 96 to 100).

This is the only large series of minimally invasive UKAs with 15-year survival data. The results support the continued use of minimally invasive UKA for the recommended indications.

Cite this article: Bone Joint J 2015;97-B:1493–99.

The cementless Oxford unicompartmental knee replacement has been demonstrated to have superior fixation on radiographs and a similar early complication rate compared with the cemented version. However, a small number of cases have come to our attention where, after an apparently successful procedure, the tibial component subsides into a valgus position with an increased posterior slope, before becoming well-fixed. We present the clinical and radiological findings of these six patients and describe their natural history and the likely causes. Two underwent revision in the early post-operative period, and in four the implant stabilised and became well-fixed radiologically with a good functional outcome.

This situation appears to be avoidable by minor modifications to the operative technique, and it appears that it can be treated conservatively in most patients.

Cite this article: Bone Joint J 2014;96-B:345–9.

Although it is clear that opening-wedge high tibial osteotomy (HTO) changes alignment in the coronal plane, which is its objective, it is not clear how this procedure affects knee kinematics throughout the range of joint movement and in other planes.

Our research question was: how does opening-wedge HTO change three-dimensional tibiofemoral and patellofemoral kinematics in loaded flexion in patients with varus deformity?Three-dimensional kinematics were assessed over 0° to 60° of loaded flexion using an MRI method before and after opening-wedge HTO in a cohort of 13 men (14 knees). Results obtained from an iterative statistical model found that at six and 12 months after operation, opening-wedge HTO caused increased anterior translation of the tibia (mean 2.6 mm, p <  0.001), decreased proximal translation of the patella (mean –2.2 mm, p <  0.001), decreased patellar spin (mean –1.4°, p < 0.05), increased patellar tilt (mean 2.2°, p < 0.05) and changed three other parameters. The mean Western Ontario and McMaster Universities Arthritis Index improved significantly (p < 0.001) from 49.6 (standard deviation (sd) 16.4) pre-operatively to a mean of 28.2 (sd 16.6) at six months and a mean of 22.5 (sd 14.4) at 12 months.

The three-dimensional kinematic changes found may be important in explaining inconsistency in clinical outcomes, and suggest that measures in addition to coronal plane alignment should be considered.

Cite this article: Bone Joint J 2014; 96-B:1214–21.

Popliteal artery injury (PAI) is a feared complication during knee replacement. Our aim was to investigate those injuries that occurred in association with knee replacement in terms of the type of injury, treatment and outcomes.

From our national vascular registry (Swedvasc) and the Swedish Patient Insurance databases a total of 32 cases were identified. Prospective data from the registries was supplemented with case-records, including long-term follow-up.

We estimated the incidence during 1998 to 2010 to be 0.017%. In our series of 32 patients with PAI occurring between 1987 and 2011, 25 (78%) were due to penetrating trauma and seven were caused by blunt trauma. The patients presented in three ways: bleeding (14), ischaemia (7) and false aneurysm formation (11), and five occurred during revision surgery. A total of 12 injuries were detected intra-operatively, eight within 24 hours (3 to 24) and 12 at more than 24 hours post-operatively (2 to 90 days). Treatment comprised open surgery in 28 patients. Patency of the vascular repair at 30 days was 97% (31 of 32, one amputation). At the time of follow-up (median 546 days, mean 677 days (24 to 1251)), 25 patients had residual symptoms. Of seven patients with a complete recovery, six had had an early diagnosis of the PAI during the procedure, and were treated by a vascular surgeon in the same hospital.

PAI is a rare adverse event during knee replacement surgery. The outcome following such events is often adversely affected by diagnostic and therapeutic delay. Bleeding and false aneurysm were the most common clinical presentations.

Cite this article: Bone Joint J 2013;95-B:1645–9.

We reviewed the relationship between the pattern of damage to the posterolateral corner of the knee and the position of the common peroneal nerve in 54 consecutive patients with posterolateral corner disruption requiring surgery. We found that 16 of the 18 patients with biceps avulsions or avulsion-fracture of the fibular head had a displaced common peroneal nerve. The nerve was pulled anteriorly with the biceps tendon. None of the 34 proximal injuries resulted in an abnormal nerve position.

Whenever bone or soft-tissue avulsion from the fibular head is suspected, the surgeon should expect an abnormal position of the common peroneal nerve and appreciate the increased risk of iatrogenic damage.

The aim of this study was to review the early outcome of the Femoro-Patella Vialla (FPV) joint replacement. A total of 48 consecutive FPVs were implanted between December 2007 and June 2011. Case-note analysis was performed to evaluate the indications, operative histology, operative findings, post-operative complications and reasons for revision. The mean age of the patients was 63.3 years (48.2 to 81.0) and the mean follow-up was 25.0 months (6.1 to 48.9). Revision was performed in seven (14.6%) at a mean of 21.7 months, and there was one re-revision. Persistent pain was observed in three further patients who remain unrevised. The reasons for revision were pain due to progressive tibiofemoral disease in five, inflammatory arthritis in one, and patellar fracture following trauma in one. No failures were related to the implant or the technique. Trochlear dysplasia was associated with a significantly lower rate of revision (5.9% vs 35.7%, p = 0.017) and a lower incidence of revision or persistent pain (11.8% vs 42.9%, p = 0.045).

Focal patellofemoral osteoarthritis secondary to trochlear dysplasia should be considered the best indication for patellofemoral replacement. Standardised radiological imaging, with MRI to exclude overt tibiofemoral disease should be part of the pre-operative assessment, especially for the non-dysplastic knee.

Cite this article: Bone Joint J 2013;95-B:793–7.

We present a series of four patients with what we have termed the snapping pes syndrome. This is a painful clicking and catching experienced at the posteromedial corner of the knee when moving from flexion to extension. Clinical examination and real time ultrasound are the most useful diagnostic tools. If medical treatment is unsuccessful surgical excision of both the semitendinous and gracilis tendons is indicated for relief of persistent symptoms.