Aims

Focal knee arthroplasty is an attractive alternative to knee arthroplasty for young patients because it allows preservation of a large amount of bone for potential revisions. However, the mechanical behaviour of cartilage has not yet been investigated because it is challenging to evaluate in vivo contact areas, pressure, and deformations from metal implants. Therefore, this study aimed to determine the contact pressure in the tibiofemoral joint with a focal knee arthroplasty using a finite element model.

Aims

Several previously identified patient-, injury-, and treatment-related factors are associated with the development of nonunion in distal femur fractures. However, the predictive value of these factors is not well defined. We aimed to assess the predictive ability of previously identified risk factors in the development of nonunion leading to secondary surgery in distal femur fractures.

Abstract

Aims. The aim of this study was to investigate the rate of revision for distal femoral arthroplasty (DFA) performed as a primary procedure for native knee fractures using data from the Australian Orthopaedic Association National Joint Arthroplasty Registry (AOANJRR). Methods. Data from the AOANJRR were obtained for DFA performed as primary procedures for native knee fractures from 1 September 1999 to 31 December 2020. Pathological fractures and revision for failed internal fixation were excluded. The five prostheses identified were the Global Modular Arthroplasty System, the Modular Arthroplasty System, the Modular Universal Tumour And Revision System, the Orthopaedic Salvage System, and the Segmental System. Patient demographic data (age, sex, and American Society of Anesthesiologists grade) were obtained, where available. Kaplan-Meier estimates of survival were used to determine the rate of revision, and the reasons for revision and mortality data were examined. Results. The AOANJRR identified 153 primary DFAs performed for native knee fractures in 151 patients during the study period, with 63.3% of these (n = 97) performed within the last five years. The median follow-up was 2.1 years (interquartile range 0.8 to 4.4). The patient population was 84.8% female (n = 128), with a mean age of 76.1 years (SD 11.9). The cumulative percent revision rate at three years was 10%. The most common reason for revision was loosening, followed by infection. Patient survival at one year was 87.5%, decreasing to 72.8% at three years postoperatively. Conclusion. The use of DFA to treat native knee fractures is increasing, with 63.3% of cases performed within the last five years. While long-term data are not available, the results of this study suggest that DFA may be a reasonable option for elderly patients with native knee fractures where fixation is not feasible, or for whom prolonged non-weightbearing may be detrimental. Cite this article: Bone Joint J 2022;104-B(7):894–901

Aims

We aimed to evaluate the utility of ⁶⁸Ga-citrate positron emission tomography (PET)/CT in the differentiation of periprosthetic joint infection (PJI) and aseptic loosening (AL), and compare it with ^99mTc-methylene bisphosphonates (^99mTc-MDP) bone scan.

Aims. To identify the prevalence of neuropathic pain after lower limb fracture surgery, assess associations with pain severity, quality of life and disability, and determine baseline predictors of chronic neuropathic pain at three and at six months post-injury. Methods. Secondary analysis of a UK multicentre randomized controlled trial (Wound Healing in Surgery for Trauma; WHiST) dataset including adults aged 16 years or over following surgery for lower limb major trauma. The trial recruited 1,547 participants from 24 trauma centres. Neuropathic pain was measured at three and six months using the Doleur Neuropathique Questionnaire (DN4); 701 participants provided a DN4 score at three months and 781 at six months. Overall, 933 participants provided DN4 for at least one time point. Physical disability (Disability Rating Index (DRI) 0 to 100) and health-related quality-of-life (EuroQol five-dimension five-level; EQ-5D-5L) were measured. Candidate predictors of neuropathic pain included sex, age, BMI, injury mechanism, concurrent injury, diabetes, smoking, alcohol, analgaesia use pre-injury, index surgery location, fixation type, Injury Severity Score, open injury, and wound care. Results. The median age of the participants was 51 years (interquartile range 35 to 64). At three and six months post-injury respectively, 32% (222/702) and 30% (234/787) had neuropathic pain, 56% (396/702) and 53% (413/787) had chronic pain without neuropathic characteristics, and the remainder were pain-free. Pain severity was higher among those with neuropathic pain. Linear regression analyses found that those with neuropathic pain at six months post-injury had more physical disability (DRI adjusted mean difference 11.49 (95% confidence interval (CI) 7.84 to 15.14; p < 0.001) and poorer quality of life (EQ-5D utility -0.15 (95% CI -0.19 to -0.11); p < 0.001) compared to those without neuropathic characteristics. Logistic regression identified that prognostic factors of younger age, current smoker, below knee fracture, concurrent injuries, and regular analgaesia pre-injury were associated with higher odds of post-injury neuropathic pain. Conclusion. Pain with neuropathic characteristics is common after lower limb fracture surgery and persists to six months post-injury. Persistent neuropathic pain is associated with substantially poorer recovery. Further attention to identify neuropathic pain post-lower limb injury, predicting patients at risk, and targeting interventions, is indicated. Cite this article: Bone Joint J 2021;103-B(6):1047–1054

Aims

In recent conflicts, most injuries to the limbs are due to blasts resulting in a large number of lower limb amputations. These lead to heterotopic ossification (HO), phantom limb pain (PLP), and functional deficit. The mechanism of blast loading produces a combined fracture and amputation. Therefore, to study these conditions, in vivo models that replicate this combined effect are required. The aim of this study is to develop a preclinical model of blast-induced lower limb amputation.

Objectives

CT-based three-column classification (TCC) has been widely used in the treatment of tibial plateau fractures (TPFs). In its updated version (updated three-column concept, uTCC), a fracture morphology-based injury mechanism was proposed for effective treatment guidance. In this study, the injury mechanism of TPFs is further explained, and its inter- and intraobserver reliability is evaluated to perfect the uTCC.

Aims

Anterior cruciate ligament (ACL) and multiligament knee (MLK) injuries increase the risk of development of knee osteoarthritis and eventual need for total knee arthroplasty (TKA). There are limited data regarding implant use and outcomes in these patients. The aim of this study was to compare the use of constrained implants and outcomes among patients undergoing TKA with a history of prior knee ligament reconstruction (PKLR) versus a matched cohort of patients undergoing TKA with no history of PKLR.

Aims

The aim of this study was to evaluate the functional outcome in patients undergoing implant removal (IR) after fracture fixation below the level of the knee.

Introduction. Fracture around the knee can lead to posttraumatic osteoarthritis (PTOA) of the knee. Malunion, malalignment, intra-articular osseous defects, retained internal fixation devices, and compromised soft tissues may affect the outcome of total knee replacement (TKR). On average, the posttraumatic patient subsets were 10.4 years younger than those for primary knee OA. Recently, there were several studies reporting the outcome of THA for posttraumatic OA hip. However, no current literature defines the comparative functional outcome between PTOA and primary OA knee. The purpose of our study was to compare the midterm outcomes of patients undergoing TKR following periarticular knee fractures/ligamentous injuries versus primary osteoarthritis (PO) of the knee. Materials and methods. Retrospective chart reviews of patients underwent TKR between 2008 and 2013 were identified. 136 patients underwent open reduction and internal fixation with plate and screws or ligament reconstruction while 716 patients were primary OA. Mean follow up time was comparable in both groups. Demographic data, medical comorbidities, WOMAC, visual analogue scale, and complications were recorded. Results. There were significantly different in age (56.5 vs 63.8 years, p<0.0001), gender (48.5% vs 63.1% of female, p=0.0014), and obese (62.3% vs 76.0%, p=0.025) between PTOA and PO groups, respectively. The PO group had higher comorbidities than PTOA group including anticoagulant usage (51% vs 30.9%, p=0.0002), number of disease ≥ 4 (69.6% vs 45.3%, p<0.0001), ASA class ≥3 (38.8% vs 21.6%, p<0.0001), and Charlson Comorbidity Index (3.6 vs 2.8, p<0.0001). The PTOA group had longer operative time (110.9 vs 100.1 minutes, p<0.0001) than PO group. Preoperatively anatomical axis of the knee was approximately valgus in PTOA but varus alignment in PO group (p<0.0001). However, postoperatively anatomical and mechanical axis was comparable in both groups. Postoperative VAS (1.8 vs 1.2, p=0.002) at 1 year follow up and pain component of WOMAC (77.8 vs 85.7, p=0.013) in PTOA group was worse than PO group, respectively. On the contrary, there was no difference in postoperative complication and readmission rate between groups. Conclusion. Total knee replacement for Post-traumatic OA was associated with poorer functional outcome compared to those for primary osteoarthritis in midterm follow up

The aim of this study was to report the incidence of arthrofibrosis of the knee and identify risk factors for its development following a fracture of the tibial plateau. We carried out a retrospective review of 186 patients (114 male, 72 female) with a fracture of the tibial plateau who underwent open reduction and internal fixation. Their mean age was 46.4 years (19 to 83) and the mean follow-up was16.0 months (6 to 80).

A total of 27 patients (14.5%) developed arthrofibrosis requiring a further intervention. Using multivariate regression analysis, the use of a provisional external fixator (odds ratio (OR) 4.63, 95% confidence interval (CI) 1.26 to 17.7, p = 0.021) was significantly associated with the development of arthrofibrosis. Similarly, the use of a continuous passive movement (CPM) machine was associated with significantly less development of arthrofibrosis (OR = 0.32, 95% CI 0.11 to 0.83, p = 0.024). The effect of time in an external fixator was found to be significant, with each extra day of external fixation increasing the odds of requiring manipulation under anaesthesia (MUA) or quadricepsplasty by 10% (OR = 1.10, p = 0.030). High-energy fracture, surgical approach, infection and use of tobacco were not associated with the development of arthrofibrosis. Patients with a successful MUA had significantly less time to MUA (mean 2.9 months; sd 1.25) than those with an unsuccessful MUA (mean 4.86 months; sd 2.61, p = 0.014). For those with limited movement, therefore, performing an MUA within three months of the injury may result in a better range of movement.

Based our results, CPM following operative fixation for a fracture of the tibial plateau may reduce the risk of the development of arthrofibrosis, particularly in patients who also undergo prolonged provisional external fixation.

Cite this article: Bone Joint J 2015;97-B:109–14.

We describe the technique and results of medial submuscular plating of the femur in paediatric patients and discuss its indications and limitations. Specifically, the technique is used as part of a plate-after-lengthening strategy, where the period of external fixation is reduced and the plate introduced by avoiding direct contact with the lateral entry wounds of the external fixator pins. The technique emphasises that vastus medialis is interposed between the plate and the vascular structures.

A total of 16 patients (11 male and five female, mean age 9.6 years (5 to 17)), had medial submuscular plating of the femur. All underwent distraction osteogenesis of the femur with a mean lengthening of 4.99 cm (3.2 to 12) prior to plating. All patients achieved consolidation of the regenerate without deformity. The mean follow-up was 10.5 months (7 to 15) after plating for those with plates still in situ, and 16.3 months (1 to 39) for those who subsequently had their plates removed. None developed a deep infection. In two patients a proximal screw fractured without loss of alignment; one patient sustained a traumatic fracture six months after removal of the plate.

Placing the plate on the medial side is advantageous when the external fixator is present on the lateral side, and is biomechanically optimal in the presence of a femoral defect. We conclude that medial femoral submuscular plating is a useful technique for specific indications and can be performed safely with a prior understanding of the regional anatomy.

Cite this article: Bone Joint J 2014;96-B:137–42.

We investigated whether an asymmetric extension gap seen on routine post-operative radiographs after primary total knee replacement (TKR) is associated with pain at three, six, 12 and 24 months’ follow-up. On radiographs of 277 patients after primary TKR we measured the distance between the tibial tray and the femoral condyle on both the medial and lateral sides. A difference was defined as an asymmetric extension gap. We considered three groups (no asymmetric gap, medial-opening and lateral-opening gap) and calculated the associations with the Western Ontario and McMaster Universities osteoarthritis index pain scores over time.

Those with an asymmetric extension gap of ≥ 1.5 mm had a significant association with pain scores at three months’ follow-up; patients with a medial-opening extension gap reported more pain and patients with a lateral-opening extension gap reported less pain (p = 0.036). This effect was still significant at six months (p = 0.044), but had lost significance by 12 months (p = 0.924). When adjusting for multiple cofounders the improvement in pain was more pronounced in patients with a lateral-opening extension gap than in those with a medial-opening extension gap at three (p = 0.037) and six months’ (p = 0.027) follow-up.

Cite this article: Bone Joint J 2013;95-B:472–7.

Although the Western Ontario and McMaster Universities (WOMAC) osteoarthritis index was originally developed for the assessment of non-operative treatment, it is commonly used to evaluate patients undergoing either total hip (THR) or total knee replacement (TKR). We assessed the importance of the 17 WOMAC function items from the perspective of 1198 patients who underwent either THR (n = 704) or TKR (n = 494) in order to develop joint-specific short forms. After these patients were administered the WOMAC pre-operatively and at three, six, 12 and 24 months’ follow-up, they were asked to nominate an item of the function scale that was most important to them. The items chosen were significantly different between patients undergoing THR and those undergoing TKR (p < 0.001), and there was a shift in the priorities after surgery in both groups. Setting a threshold for prioritised items of ≥ 5% across all follow-up, eight items were selected for THR and seven for TKR, of which six items were common to both. The items comprising specific WOMAC-THR and TKR function short forms were found to be equally responsive compared with the original WOMAC function form.

Cite this article: Bone Joint J 2013;95-B:239–43.

Current analysis of unicondylar knee replacements (UKRs) by national registries is based on the pooled results of medial and lateral implants. Consequently, little is known about the differential performance of medial and lateral replacements and the influence of each implant type within these pooled analyses. Using data from the National Joint Registry for England and Wales (NJR) we aimed to determine the proportion of UKRs implanted on the lateral side of the knee, and their survival and reason for failure compared with medial UKRs. By combining information on the side of operation with component details held on the NJR, we were able to determine implant laterality (medial versus lateral) for 32 847 of the 35 624 unicondylar replacements (92%) registered before December 2010. Of these, 2052 (6%) were inserted on the lateral side of the knee. The rates of survival at five years were 93.1% (95% confidence interval (CI) 92.7 to 93.5) for medial and 93.0% (95% CI 91.1 to 94.9) for lateral UKRs (p = 0.49). The rates of failure remained equivalent after adjusting for patient age, gender, American Society of Anesthesiologists (ASA) grade, indication for surgery and implant design using Cox’s proportional hazards method (hazard ratio for lateral relative to medial replacement = 0.88 (95% CI 0.69 to 1.13); p = 0.32). Aseptic loosening/lysis and unexplained pain were the main reasons for revision in both groups, although the reasons did vary depending on whether a mobile- or a fixed-bearing design was used. At a maximum of eight years the mid-term survival rates of medial and lateral UKRs are similar.

We report our retrospective multicentre experience of managing periprosthetic knee fractures using locking plates, cemented nails and distal femoral prosthesis. The Aim of this study is to analyze the practicality of management of these injuries using modern methods of fixation or salvation. 62 patients presented to 3 centres between 2003 and 2010. After implementation of inclusion criteria, clinical, radiological and functional outcomes were evaluated in 54 patients, with a minimum follow-up of 6 months. 34 patients were treated with locking plates (10 males, 24 female; mean age 76), 16 with cemented/locking nails (4 males, 12 females; mean age 84.5), and 4 with distal femoral replacement prosthesis (2 males, 2 females; mean age 79). Locking plates which were used with a minimally invasive pattern produced the best outcomes in our study. A statistical significance of p value of less than 0.01 was found in union time between patients operated on with an open technique (6.69±2.69 months) and those operated on with a minimally invasive technique (3.6±0.91 months). Nailing with augmented cement is a useful technique in patients who are not suitable for challenging surgery & rehabilitation programmes. There was a significant difference in mean time to functional weight bearing (p< 0.01) between the plate group (4.79±2.6 months) and the nail group (2.63±0.5 months). Post-operative range of motion was also better for nails (106.36±14.33. O. flexion) compared to plates (93.24±26.8. O. ), a result that approached significance (p=0.065). We recommend minimal invasive plating in uncompromised physiological conditions, as an ideal method of fracture fixation in view of statistically significant union rates. Cemented nailing is recommended in patients where early rehabilitation is essential. Distal Femoral prosthesis replacement is a useful salvage method

Introduction. Unicompartmental arthroplasty is still a controversial issue in knee replacement, mainly due to a marked variation in published survival rates of the implants. The aim of this study was to analyse possible risk factors for revision following Oxford unicompartmental knee arthroplasties (OUKA). Material and methods. Since 1997 data for all patients with primary and revision knee arthroplasties performed in our department have been stored in a database. Selected for the present study was all primary OUKA performed in the period 1997–2006 as well as any revision following these operations until the end of 2008. We got information from The National Health Register and the CPR register about any revision performed at other institutions and date in case of death. Primary OUKA were grouped in three categories according to the experience of the surgeon: 1 for operation done by a surgeon who had performed less than 20 OUKA, 2 for operation by a surgeon who had performed 20–40, and 3 for operation by a surgeon who had performed more than 40. Risk of revision was analysed by Cox regression. Revisions due to pain as the only reason were excluded from the analyses. Age and gender of the patients, previous surgical intervention, operation time, and the experience of the surgeon were included as possible risk factors in the analysis. Results. 445 primary Oxford knee arthroplasties were included. These were followed by 46 revisions. The indications for the revisions were: aseptic loosening 16 knees, progression of the osteoarthritis to the lateral compartment 7 knees, dislocation of the polyethylene meniscus 5 knees, varus-valgus instability 3 knees, fracture of the medial tibia condyle 3 knees, collision of the polyethylene meniscus and the femur condyle 1 knee, and pain as the only reason 11 knees. Age and gender of the patients as well as previous surgical intervention in the knee in question were not correlated to the risk of revision. Operation time was correlated to risk of revision with decreasing risk with increasing operation time (p=0,001). The experience of the surgeon was also correlated to risk of revision with decreasing risk with increasing experience (p=0,02). The 6 years survival rate for an experienced surgeon using an operation time at 90 min. or more was 97,5 % compared to a survival rate at 78,7 % for an inexperienced surgeon with an operation time less than 90 min. Conclusion. OUKA performed by an inexperienced surgeon and OUKA performed with short operation time had marked reduced survival rates. This seems to be an essential information to institutions performing OUKA