Aims. Endoprosthetic reconstruction with a distal femoral arthroplasty (DFA) can be used to treat distal femoral bone loss from oncological and non-oncological causes. This study reports the short-term implant survivorship, complications, and risk factors for patients who underwent DFA for non-neoplastic indications. Methods. We performed a retrospective review of 75 patients from a single institution who underwent DFA for non-neoplastic indications, including aseptic loosening or mechanical failure of a previous prosthesis (n = 25), periprosthetic joint infection (PJI) (n = 23), and native or periprosthetic distal femur fracture or nonunion (n = 27). Patients with less than 24 months’ follow-up were excluded. We collected patient demographic data, complications, and reoperations. Reoperation for implant failure was used to calculate implant survivorship. Results. Overall one- and five-year implant survivorship was 87% and 76%, respectively. By indication for DFA, mechanical failure had one- and five-year implant survivorship of 92% and 68%, PJI of 91% and 72%, and distal femur fracture/nonunion of 78% and 70% (p = 0.618). A total of 37 patients (49%) experienced complications and 27 patients (36%) required one or more reoperation. PJI (n = 16, 21%), aseptic loosening (n = 9, 12%), and wound complications (n = 8, 11%) were the most common complications. Component revision (n = 10, 13.3%) and single-stage exchange for PJI (n = 9, 12.0 %) were the most common reoperations. Only younger age was significantly associated with increased complications (mean 67 years (SD 9.1)) with complication vs 71 years (SD 9.9) without complication; p = 0.048). Conclusion. DFA is a viable option for distal femoral bone loss from a range of non-oncological causes, demonstrating acceptable short-term survivorship but with high overall complication rates. Cite this article: Bone Jt Open 2022;3(3):173–181

There is a paucity of data available for the use of Total Femoral Arthroplasty (TFA) for joint reconstruction in the non-oncological setting. The aim of this study was to evaluate TFA outcomes with minimum 5-year follow-up. This was a retrospective database study of TFAs performed at a UK tertiary referral revision arthroplasty unit. Inclusion criteria were patients undergoing TFA for non-oncological indications. We report demographics, indications for TFA, implant survivorship, clinical outcomes, and indications for re-operation. A total of 39 TFAs were performed in 38 patients between 2015–2018 (median age 68 years, IQR 17, range 46–86), with 5.3 years’ (IQR 1.2, 4.1–18.8) follow-up; 3 patients had died. The most common indication (30/39, 77%) for TFA was periprosthetic joint infection (PJI) or fracture-related infection (FRI); and 23/39 (59%) had a prior periprosthetic fracture (PPF). TFA was performed with dual-mobility or constrained cups in 31/39 (79%) patients. Within the cohort, 12 TFAs (31%) required subsequent revision surgery: infection (7 TFAs, 18%) and instability (5 TFAs, 13%) were the most common indications. 90% of patients were ambulatory post-TFA; 2 patients required disarticulation due to recurrent PJI. While 31/39 (79%) were infection free at last follow-up, the remainder required long-term suppressive antibiotics. This is the largest series of TFA for non-oncological indications. Though TFA has inherent risks of instability and infection, most patients are ambulant after surgery. Patients should be counselled on the risk of life-long antibiotics, or disarticulation when TFA fails

Aims. The purpose of this study was to compare reoperation and revision rates of double plating (DP), single plating using a lateral locking plate (SP), or distal femoral arthroplasty (DFA) for the treatment of periprosthetic distal femur fractures (PDFFs). Methods. All patients with PDFF primarily treated with DP, SP, or DFA between 2008 and 2022 at a university teaching hospital were included in this retrospective cohort study. The primary outcome was revision surgery for failure following DP, SP, or DFA. Secondary outcome measures included any reoperation, length of hospital stay, and mortality. All basic demographic and relevant implant and injury details were collected. Radiological analysis included fracture classification and evaluation of metaphyseal and medial comminution. Results. A total of 111 PDFFs (111 patients, median age 82 years (interquartile range (IQR) 75 to 88), 86% female) with 32 (29%) Su classification 1, 37 (34%) Su 2, and 40 (37%) Su 3 fractures were included. The median follow-up was 2.5 years (IQR 1.2 to 5.0). DP, SP, and DFA were used in 15, 66, and 30 patients, respectively. Compared to SP, patients treated with DP were more likely to have metaphyseal comminution (47% vs 14%; p = 0.009), to be low fractures (47% vs 11%; p = 0.009), and to be anatomically reduced (100% vs 71%; p = 0.030). Patients selected for DFA displayed comparable amounts of medial/metaphyseal comminution as those who underwent DP. At a minimum follow-up of two years, revision surgery for failure was performed in 11 (9.9%) cases at a median of five months (IQR 2 to 9): 0 DP patients (0%), 9 SP (14%), and 2 DFA (6.7%) (p = 0.249). Conclusion. Using a strategy of DP fixation in fractures, where the fracture was low but there was enough distal bone to accommodate locking screws, and where there is metaphyseal comminution, resulted in equivalent survival free from revision or reoperation compared to DFA and SP fixation. Cite this article: Bone Jt Open 2024;5(6):489–498

Background

Patellofemoral replacement is an established intervention in selected patients with severe isolated patellofemoral osteoarthritis. FPV (Wright Medical, UK) is a third generation patellofemoral arthroplasty implant and is the second most used after AVON in National Joint Registry for England and Wales. Reports of survivorship and functional of this implant are scarce in literature.

Isolated patellofemoral arthritis occurs in up to 10% of patients suffering osteoarthritis of the knee. Previous reports of several different patellofemoral designs have given indifferent results. The Lubinus prosthesis has been shown to have a 50% failure rate at eight years in a study of 76 cases. The main reasons for failure were mal-alignment, wear, impingement and disease progression. As a result of these studies, a new prosthesis was designed to solve some of these problems.

The Avon patellofemoral arthroplasty was first implanted in September 1996. The cases have been entered into a prospective review with evaluations at eight months, two years and five years. The outcome was assessed using pain scores, Bartlett’s patella score and the Oxford knee score. To date, 186 knees have been treated; over 100 knees have been reviewed at two years and 20 knees at five years. The main pain score improved from a pre-operative level of 13.5 points out of 40 to 33.5 points at two years and 36 at five years. The mean pre-operative movement was 109° and this increased to 120° at five years. The Bartlett patella score improved from a pre-operative level of 10.5 points out of 30 pre-operatively to 23 points at two years and 25 at five years. The Oxford knee score was 20 points out of 48 pre-operatively and this improved to 35 points at two years and 40 points at five years. One patient developed subluxation, which required distal soft tissue realignment. No other patient has developed problems with alignment or wear. Ten knees have developed evidence of disease progression usually in the medial compartment of which six have required revision to a total knee replacement.

The results to date suggest that this improved design has all but eliminated the previous problems of malalignment and early wear. The functional results are as good or better than those of a total knee replacement. There is a low complication rate and an excellent range of movement. Disease progression remains a potential problem. This type of prosthesis offers a reasonable alternative to total knee replacement in this small group of patients with isolated, early patellofemoral disease.

Comparison of two cementing techniques: femoral component insertion into early-cure stage cement and insertion into late-cure stage cement in an in vivo model to identify if cement cure stage affects the strength of the bone cement interface.

Bilateral arthroplasties – using only the femoral component - were performed in vivo on paired porcine femora. The femora were harvested and cross-sectioned in preparation for strength testing. Performance was measured by peak load required to push the femoral prosthesis and surrounding cement mantle free of the cancellous bone.

The mean failure load for prostheses inserted into late cure stage cement was 908 N +/− SD 420, whereas the mean failure load for the conjugate early cure stage cement was 503 N +/− SD 342. A paired t-test indicated significantly higher load failure rates in the late cure stage cement versus the early cure stage samples (t=2.37, p< 0.049).

Femoral component insertion into late cure stage cement required statistically significant higher loads for push-out when compared to femoral component insertion into early cure stage cement.

Introduction. The management of peri-prosthetic distal femur fractures following TKR (Total Knee Replacement) in the elderly remains a challenge with little or no consensus on the best available treatment. Various methods have been described in the management of these complex fractures. Our study compares the outcome and cost of distal femoral arthroplasty to that of Fixation (Plating/Retrograde Nailing). Methods. We retrospectively reviewed our database for patients admitted with peri-prosthetic distal femoral fractures between 2005–2013 (n=61). The patients were stratified into 2 groups based on method of management. The Distal Femoral Arthroplasty group (Group A) had 21 patients, with a mean age of 78 years (68–90. The Fixation group (Group B) had 40 patients, with a mean age of 74 years, 23 of those had plating of the fracture, while 17 had a retrograde nail inserted. Pain scores, Length of stay, intra-operative blood loss, and weight bearing status, were compared. Functional outcomes were also assessed using Oxford knee scores, KSS scores, VAS pain assessment and range of motion from last follow up appointment. Minimum follow-up was 2 years. Cost analysis was done for both groups, which included implant costs, consumable costs (man power included), theatre utilisation time and length of hospital stay. The calculation was done based on the PbR (payment by results) system and “best practise tariffs 2010–11” utilised by the NHS (National Health Service) in England. Results. In group A, the average surgical time was 116 minutes with mean blood loss of 400 ml. In group B, the mean surgical time was 123 minutes with average blood loss of 800 ml. The mean length of hospital stay in group A was 9 days whereas in group B was 32 days. All patients were fully weight bearing by day 1.5(range 1–3 days) in group A, compared to a mean of 11 weeks in group B. Mean Oxford score was 28 and KSS score was 70 in group A compared to 27 and 68 in group B. The pain score on VAS was 2 for group A and 1.5 for group B. The mean ROM of the knee was 95° in group A and 85° in group B. We had 4 complications in group A. There were 2 deaths due to medical co-morbidities, 1 superficial infection, and 1 DVT. In the fixation group, there were 6 deaths due to medical co-morbidities, 1 failure of fixation, 6 mal-unions, 1 non-union and 2 infections. Overall, the distal femoral arthroplasty procedure costs approximately £10000, and the fixation group costs were on average of £9800. Discussion & Conclusion. Distal femoral arthroplasty allowed early mobilisation, thus avoiding prolonged hospital stay and reducing the risk of inpatient related morbidity. Complication rates were lower than the fixation group and the overall costs were comparable to that of fixation. Distal femoral arthroplasty appears to be a promising alternative treatment to internal fixation in elderly patients with distal femoral peri-prosthetic fractures. With appropriate patient selection, the prosthesis is likely to survive for the duration of patient's lifetime

Aims. Limb salvage in bone tumour patients replaces the bone with massive segmental prostheses where achieving bone integration at the shoulder of the implant through extracortical bone growth has been shown to prevent loosening. This study investigates the effect of multidrug chemotherapy on extracortical bone growth and early radiological signs of aseptic loosening in patients with massive distal femoral prostheses. Methods. A retrospective radiological analysis was performed on adult patients with distal femoral arthroplasties. In all, 16 patients were included in the chemotherapy group with 18 patients in the non-chemotherapy control group. Annual radiographs were analyzed for three years postoperatively. Dimensions of the bony pedicle, osseointegration of the hydroxyapatite (HA) collar surface, bone resorption at the implant shoulder, and radiolucent line (RLL) formation around the cemented component were analyzed. Results. A greater RLL score (p = 0.041) was observed at three years postoperatively, with those receiving chemotherapy showing greater radiological loosening compared with those not receiving chemotherapy. Chemotherapy patients experience osteolysis at the shoulder of the ingrowth collar over time (p < 0.001) compared with non-chemotherapy patients where osteolysis was not observed. A greater median percentage integration of the collar surface was observed in the non-chemotherapy group (8.6%, interquartile range (IQR) 0.0% to 37.9%; p = 0.021) at three years. Bone growth around the collar was observed in both groups, and no statistical difference in amount of extracortical bony bridging was seen. Conclusion. Multidrug chemotherapy affects the osseointegration of ingrowth collars and accelerates signs of radiological loosening. This may increase the risk of aseptic loosening in patients with massive segmental implants used to treat bone cancer. Cite this article: Bone Joint Res 2020;9(7):333–340

Purpose:. Biomechanical knowledge of the medial collateral ligament (MCL) is important for MCL release during knee arthroplasty. The purpose of this study was to define the influences of the deep medial collateral ligament (dMCL) and the posterior oblique ligament (POL) on valgus and rotatory stability in knee arthroplasty. Methods:. Six cadaveric knees were divided into 2 groups with unique sequential sectioning sequences of the dMCL and the POL. Group A (n = 2) first received femoral arthroplasty only, and thereafter sequentially received medial half tibial resection with spacer, ACL cut, dMCL cut, POL cut, and finally tibial arthroplasty. Group B (n = 4) first received femoral arthroplasty only, and thereafter sequentially received medial half tibial resection with spacer, ACL cut, tibial arthroplasty, dMCL cut, and finally, POL cut. A CT-free navigation system monitored motion after application of valgus loads (10 N-m) and internal and external rotation torques (5 N-m) at 0°, 20°, 30°, 60°, and 90°of knee flexion. Results:. There were no significant differences in medial gaps under valgus loads after cutting dMCL, but significant differences were seen in medial gaps after cutting POL. Internal rotation angles increased after cutting POL under internal rotation torques at over 20°of knee flexion. External rotation angles under external rotation torques increased after cutting dMCL at 90°. In addition, external rotation angles further increased after cutting POL. Accordingly, while increases of medial gap size and rotatory instability were not clearly recognized with the sectioning of the dMCL, significant increases of valgus and rotatory instability were seen on sectioning of the POL

The aim of this study was to report our experience of patellofemoral arthroplasty in isolated osteoarthrosis. Material and Methods: The Lubinus Patellofemoral Arthroplasty was performed between 1989 and 1995 in 76 knees. The Avon Patella Femoral Arthroplasty was used from 1996 to 2001 in 187 knees. The average age of the patients was 65.5 years (range 36–87) with a male to female ratio of 1: 5. All the patients have been prospectively reviewed with standard radiographs, the Bristol Knee Score, and more recently Bartlett and Oxford scores. Results: Patients with the Lubinus prosthesis were followed for an average of 7.4 years (range 5–10 years). Eleven patients (14 knees) have died and the remaining 62 knees have a 100% follow-up. The cumulative revision rate was 28% (21 out of 76). Survivorship at 8 years was 65% (Cl 49 to 77) for revision and 48% (Cl 36 to 59) for revision plus moderate pain. The two main complications were Maltracking 32% and progressive tibio-femoral arthritis in 9%. The Avon Arthroplasty with improved design features for better tracking and congruity was introduced in 1996 and 187 have now been inserted in 147 patients. One hundred and nine knees have been followed for 8 months and 82 have completed the 2 year follow-up. Two patients have undergone revision to a TKR 97.5% (survivorship 2 out of 82). Three patients have had a unicompartmental arthroplasty added for disease progression. There have been no cases of patella maltracking or subliaxation. Four year survivorship for moderate pain and revision is 96% (79 out of 82). Functional scores compared favourably with parallel series of total knee replacements. Conclusion: The medium-term results of the Lubinus Patello Femoral Arthroplasty are unsatisfactory. We suggest the use of this prosthesis should be discontinued. The Avon Arthroplasty has improved results in the short-term

Introduction. Many factors can influence post-operative kinematics after total knee arthroplasty (TKA). These factors include intraoperative surgical conditions such as ligament release or quantity of bone resection as well as differences in implant design. Release of the medial collateral ligament (MCL) is commonly performed to allow correction of varus knee. Precise biomechanical knowledge of the individual components of the MCL is critical for proper MCL release during TKA. The purpose of this study was to define the influences of the deep medial collateral ligament (dMCL) and the posterior oblique ligament (POL) on valgus and rotatory stability in TKA. Materials and Methods. This study used six fresh-frozen cadaveric knees with intact cruciate ligaments. All TKA procedures were performed by the same surgeon using CR-TKA with a CT-free navigation system. Each knee was tested at 0°, 20°, 30°, 60°, and 90° of flexion. One sequential sectioning sequence was performed on each knee, beginning with an intact knee (S0), and thereafter femoral arthroplasty only (S1), tibial arthroplasty (S2), release of the dMCL (S3), and finally, release of the POL (S4). The same examiner applied all external load of 10 N-m valgus and a 5 N-m internal and external rotation torque at each flexion angle for the each cutting state. All data were analyzed statistically using one-way ANOVA and we investigated the correlation between the medial gap and the rotation angle. A significant difference was determined to be present for P < .05. Results. There were no correlation between the medial gap and the rotation angle in S0. A moderate correlation was found in S1 at 0° and 20°, and a considerable correlation was found in S2 at 90°. There was a correlation at all angles in S4, and especially strong at 20°, 60°, 90°. Conclusion. From this study, there were no correlation between medial knee instability and total rotation angles after performing TKA only by releasing dMCL, but by adding POL release, there were correlation in all angles. Therefore, medial knee instability caused by excessive release of the main medial knee structures may promote rotational instability

Aims

Femoral periprosthetic fractures are rising in incidence. Their management is complex and carries a high associated mortality. Unlike native hip fractures, there are no guidelines advising on time to theatre in this group. We aim to determine whether delaying surgical intervention influences morbidity or mortality in femoral periprosthetic fractures.

Introduction. Many factors can influence post-operative kinematics after total knee arthroplasty (TKA). These factors include intraoperative surgical conditions such as ligament release or quantity of bone resection as well as differences in implant design. Release of the medial collateral ligament (MCL) is commonly performed to allow correction of varus knee. Precise biomechanical knowledge of the individual components of the MCL is critical for proper MCL release during TKA. The purpose of this study was to define the influences of the deep medial collateral ligament (dMCL) and the posterior oblique ligament (POL) on kinematics in TKA. Materials and Methods. This study used six fresh-frozen cadaveric knees with intact cruciate ligaments. All TKA procedures were performed by the same surgeon using CR-TKA with a CT-free navigation system. Each knee was tested at 0°, 20°, 30°, 60°, and 90° of flexion. One sequential sectioning sequence was performed on each knee, beginning with femoral arthroplasty only (S1), and thereafter sequentially; medial half tibial resection with spacer (S2), ACL cut (S3), tibial arthroplasty (S4), release of the dMCL (S5), and finally, release of the POL (S6). The same examiner applied all external loads of 10 N-m valgus and 5 N-m internal and external rotation torques at each flexion angle and for each cut state. The AP locations of medial and lateral condyles were determined as the lowest point on each femoral condyle. All data were analyzed statistically using paired t-test. A significant difference was determined to be present for P < .05. Results. All knees showed that posterior femoral translation of the lateral condyle from 0° to 90° was greater than posterior femoral translation of the medial condyle at any step or any tested angle. Posterior femoral translation of the medial femoral condyle under valgus load significantly increased after S4 compared with that at S1 at 20°, 30° and 90°, and after S5 compared with that at S1 at 20° and 30°. Thereafter, significant increase in posterior translation of the medial condyle was seen, at 30° after S6 compared with S1. Posterior femoral translation of the medial femoral condyle under external rotation torque significantly increased after S4 at 90°, and S6 at 0° compared with that at S1. Posterior femoral translation of the medial femoral condyle under internal rotation torque significantly increased after S2 at 0°, after S4 at 60° and 90°, after S5 at 0°, and after S6 at 60° compared with S1. Conclusion. From this study we concluded that retaining of the medial knee structures preserves the valgus and rotatory stability of the knee after TKA. Accordingly, to devise a surgical approach of retaining the dMCL and POL has a possibility to improve outcomes after primary TKA

Aims

The aim of this modified Delphi process was to create a structured Revision Hip Complexity Classification (RHCC) which can be used as a tool to help direct multidisciplinary team (MDT) discussions of complex cases in local or regional revision networks.

Introduction. Many factors can influence post-operative kinematics after total knee arthroplasty (TKA). These factors include intraoperative surgical conditions such as ligament release or quantity of bone resection as well as differences in implant design. Release of the medial collateral ligament (MCL) is commonly performed to allow correction of varus knee. Precise biomechanical knowledge of the individual components of the MCL is critical for proper MCL release during TKA. The purpose of this study was to define the influences of the deep medial collateral ligament (dMCL) and the posterior oblique ligament (POL) on valgus and rotatory stability in TKA. Materials and Methods. This study used six fresh-frozen cadaveric knees with intact cruciate ligaments. All TKA procedures were performed by the same surgeon using CR-TKA with a CT-free navigation system. Each knee was tested at 0°, 20°, 30°, 60°, and 90° of flexion. One sequential sectioning sequence was performed on each knee, beginning with femoral arthroplasty only (S1), and thereafter sequentially, medial half tibial resection with spacer (S2), ACL cut (S3), tibial arthroplasty (S4), release of the dMCL (S5), and finally, release of the POL (S6). The same examiner applied all external loads of 10 N-m valgus and 5 N-m internal and external rotation torques at each flexion angle and for each cut state. All data were analyzed statistically using two-way ANOVA and paired t-test. A significant difference was determined to be present for P < .05. Results. There were no significant differences in medial gaps at any sequential step or any tested angle of flexion under valgus loads even after release of the dMCL and the POL compared with those at S1. Internal rotation angles significantly increased after medial half tibial resection with spacer, compared with those after S1, at 0°, 20°, and 30°. Moreover, release of the POL under internal rotation torque resulted in significantly increased internal rotation, compared with that at S1, at 90° of knee flexion. External rotation angles under external rotation torque significantly increased after the ACL cut compared with those at S1 at 0°, and after tibial arthroplasty, significant increase in external rotation angles compared with those at S1 was observed at 60°. Thereafter, significant increase in external rotation angles was seen, at 0°, 30° and 90° after release of the dMCL compared with S1, and significant increase after release of the POL at 30°, 60° and 90° compared to S1. 20°. Rotational angles had correlation with the size of medial gap at 0°, 20° and 90°. Conclusion. From this study we concluded that retaining of the medial knee structures preserves the valgus and rotatory stability of the knee. Accordingly, to devise a surgical approach of retaining the dMCL and POL has a possibility to improve the outcome after primary TKA

Aims

The aim of this study was to evaluate medium-term outcomes and complications of the S-ROM NOILES Rotating Hinge Knee System (DePuy, USA) in revision total knee arthroplasty (rTKA) at a tertiary unit.

Introduction: Computer aided surgery has been used in orthopaedics for over a decade now. It has mainly found its use in knee and hip arthroplasty. Its use in other areas is still under development. There has been only one published report in literature on its use in patello femoral joint replacement arthroplasty. We did a study to evaluate its use in patello-femoral arthroplasty. Methods: A retrospective group of patients was selected who had patello-femoral joint arthroplasty under one of the authors with non navigated standard technique. This was compared with another group which was followed prospectively and had it done with minimally invasive technique using computer aided navigation. The main factors compared were blood loss, incision size and hospital stay. Results: Thirteen patients had patello-femoral arthroplasty. Seven had with aid of computer aided navigation technique. There was a distinct advantage of computer aided surgery in blood loss, hospital stay and size of incision. It had no bearing on the surgical outcome in short term. Long term results are still awaited. Conclusion: While our study is only short term and does not have many patients, there seems to be a distinct advantage in terms of hospital stay and size of incision

Introduction. Modular femoral necks have shown promising clinical results in total hip arthroplasty (THA) to optimize offset, rotation, and leg length. Given the wide variety of proximal femoral morphology, fine-tuning these kinematic parameters can help decrease femoroacetabular impingement, decrease wear rates and help prevent dislocations. Yet, additional implant junctions introduce additional mechanisms of failure. We present two patients who developed an abnormal soft tissue reaction consistent with a metal hypersensitivity reaction at a modular femoral neck/stem junction requiring revision arthroplasty. Methods. Two patients underwent THA for primary osteoarthritis with the same series of components: 50 mm shell, a 36 mm highly-crosslinked polyethylene liner, uncemented titanium alloy modular stem with a 130 degree Cobalt Chromium (CoCr) modular femoral neck, and 36 mm CoCr head with a +5-mm offset. Patient 1 was a 63 year-old female who had an uneventful post-operative course but presented seven months later with progressive pain in the left hip. Patient 2 was an 80 year-old female who did well post-operatively, but presented with limp and persistent pain at 10 months post-op. An initial evaluation of a painful THA to rule out aseptic loosening, infection, mal-positioning, loosening and osteolysis included radiographs, lab work (CBC, ESR, CRP, Cobalt & Chromium levels) and Metal Artifact Reduction Sequence (MARS) MRI. Results. Elevated ion levels (Table 1) and Metal Artifact Reduction Sequence (MARS) MRI were consistent with an abnormal soft tissue reaction. A histological analysis of operative specimens displayed extensive necrosis and lymphocytosis, consistent with the diagnosis of metal hypersensitivity reactions (MHSR). Both patients underwent debridement and revision femoral arthroplasty with non-modular counterparts of the original femoral implant and have been asymptomatic post-operatively at greater than 1 year follow-up. Discussion. MHSR reactions are primarily described in the setting of metal on metal articulations of the head and acetabulum in THA and hip resurfacing. These reactions have not been reported at the modular neck/stem junction. Although modular necks show promise in THA, the advantages of increased component modularity must be carefully weighed against the risks of mechanical wear and subsequent MHSR and/or component failure

Aims

Hydroxyapatite (HA)-coated collars have been shown to reduce aseptic loosening of massive endoprostheses following primary surgery. Limited information exists about their effectiveness in revision surgery. The aim of this study was to radiologically assess osteointegration to HA-coated collars of cemented massive endoprostheses following revision surgery.

Introduction

In response to the COVID-19 pandemic, there was a rapidly implemented restructuring of UK healthcare services. The The Royal National Orthopaedic Hospital, Stanmore, became a central hub for the provision of trauma services for North Central/East London (NCEL) while providing a musculoskeletal tumour service for the south of England, the Midlands, and Wales and an urgent spinal service for London. This study reviews our paediatric practice over this period in order to share our experience and lessons learned. Our hospital admission pathways are described and the safety of surgical and interventional radiological procedures performed under general anaesthesia (GA) with regards to COVID-19 in a paediatric population are evaluated.