➢ Neurological injury remains the most common reason for ligation following total hip arthroplasty.➢ The main risk factors for neurological injury following total hip arthroplasty are preexisting spinal pathology, revision surgery, complex hip anatomy, female sex, surgeon inexperience, and excessive limb lengthening.➢ Postoperative pelvic computed tomographic scans may be used to assess component positioning and identify any compressive hematomas. Magnetic resonance imaging with a metal artifact reduction protocol may be used to evaluate architectural changes in the affected nerve.➢ Electromyography and nerve conduction studies may help to assess the level and grade of the nerve injury. These tests are most useful when performed in patients who show no signs of neurological improvement 3 to 6 weeks after surgery.➢ The mainstay of nonoperative management is supportive care with physical therapy, an ankle-foot orthosis, and neuropathic pain treatment.➢ The prognosis for a femoral nerve injury is generally more favorable than that for a sciatic nerve injury following total hip arthroplasty.

The management of femoral bone loss is challenging during revision hip arthroplasty. In patients with Paprosky grade IIIB and IV defects, obtaining fixation and rotational stability using traditional surgical constructs is difficult. The use of a custom-made internal proximal femoral replacement prostheses has been proposed as a solution in patients, with severe femoral bone stock loss. However, there is a paucity in the literature on their use and long-term outcomes. We report on the clinical and radiological results of our cohort.We retrospectively reviewed all patients who underwent internal proximal femoral replacement for revision hip arthroplasty between April 1996 and April 2019. All patients had at least 2 years of follow-up time.160 patients underwent limb salvage at our institution using internal proximal femoral replacement. The mean follow-up was 79.7 months (S.D 41.3). Indications for revision included periprosthetic fractures, aseptic loosening, and deep infection. The mean Oxford hip score increased from 13.8 (0–22) to 31.5 (18–43) (paired t-test, p < 0.001). Kaplan-Meier prosthesis survival analysis with revision as the endpoint was 87% at 5 years. None required revision of the femoral stem. There were four dislocations (5%) and there was failure to eradicate the deep infection in four.This technique allows instant distal fixation, allowing for early mobilisation. Long-term clinical and radiological outcomes are encouraging and the complication rates are acceptable for this patient group.

Abstract: We previously conducted a single-arm, prospective study in which 31 patients (mean age [and standard deviation], 42.5 ± 11.3 years) with cartilage lesions were treated with use of the BioPoly Partial Resurfacing Knee Implant. Treatment outcomes were compared with those reported for the standard of care, microfracture. We found that the mean KOOS (Knee injury and Osteoarthritis Outcome Score) Quality of Life score at 5 years in the BioPoly cohort was noninferior to (p = 0.004), and indeed greater than (p = 0.021), that in the microfracture cohort. The BioPoly cohort demonstrated improvement in the mean scores for all KOOS domains at every postoperative time point (p < 0.025). The mean score for the visual analog scale (VAS) for pain significantly improved (p < 0.025) at all time points up to 4 years and trended toward significant improvement at 5 years (p = 0.027). This study indicated that the BioPoly implant was safe, provided significant improvement starting at 6 months and continuing to 5 years, and provided greater improvement than microfracture for some outcome measures. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Abstract:. We previously conducted a single-arm, prospective study in which 31 patients (mean age [and standard deviation], 42.5 ± 11.3 years) with cartilage lesions were treated with use of the BioPoly Partial Resurfacing Knee Implant. Treatment outcomes were compared with those reported for the standard of care, microfracture. We found that the mean KOOS (Knee injury and Osteoarthritis Outcome Score) Quality of Life score at 5 years in the BioPoly cohort was noninferior to (p = 0.004), and indeed greater than (p = 0.021), that in the microfracture cohort. The BioPoly cohort demonstrated improvement in the mean scores for all KOOS domains at every postoperative time point (p < 0.025). The mean score for the visual analog scale (VAS) for pain significantly improved (p < 0.025) at all time points up to 4 years and trended toward significant improvement at 5 years (p = 0.027). This study indicated that the BioPoly implant was safe, provided significant improvement starting at 6 months and continuing to 5 years, and provided greater improvement than microfracture for some outcome measures. Level of Evidence:. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Background: Fungal infections are a rare cause of periprosthetic joint infection (PJI), identified in 1% of all of these cases. Outcomes are not well-established due to small cohort sizes in the published literature. The aims of this study were to establish the patient demographics and infection-free survival of patients presenting to 2 high-volume revision arthroplasty centers who had fungal infection of either a hip or knee arthroplasty. We sought to identify risk factors for poor outcomes. Methods: A retrospective analysis was performed of patients at 2 high-volume revision arthroplasty centers who had confirmed fungal PJI of the total hip arthroplasty (THA) and total knee arthroplasty (TKA). Consecutive patients treated between 2010 and 2019 were included. Patient outcomes were classified as infection eradication or persistence. A total of 67 patients who had 69 fungal PJI cases were identified. There were 47 cases involving the knee and 22 of the hip. Mean age at presentation was 68 years (THA mean 67, range 46 to 86) (TKA mean 69, range, 45 to 88). A history of sinus or open wound was present in 60 cases (89%) (THA 21 cases, TKA 39 cases). The median number of operations prior to the procedure at which fungal PJI was identified was 4 (range, 0 to 9), THA 5 (range, 3 to 9), and TKA 3 (range, 0 to 9). Results: At a mean follow-up 34 months (range, 2 to 121), remission rates were 11 of 24 (45%) and 22 of 45 (49%) for hip and knee, respectively. There were 7 TKA (16%) and 1 THA cases (4%) that failed treatment resulting in amputations. During the study period, 7 THA and 6 TKA patients had died. Two deaths were directly attributable to PJI. Patient outcome was not associated with the number of prior procedures, patient comorbidities, or organisms. Conclusion: Eradication of fungal PJI is achieved in less than half of patients, and outcomes are comparable for TKA and THA. The majority of patients who have fungal PJI present with an open wound or sinus. No factors were identified that increase the risk of persistent infection. Patients who have fungal PJI should be informed of the poor outcomes. Crown Copyright (c) 2023 Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

AbstractIntroductionTotal knee replacement (TKR) in patients with skeletal dysplasia is technically challenging surgery due to deformity, joint contracture, and associated co-morbidities. The aim of this study is to follow up patients with skeletal dysplasia following a TKR.MethodologyWe retrospectively reviewed 22 patients with skeletal dysplasia who underwent 31 TKRs at our institution between 2006 and 2022. Clinical notes, operative records and radiographic data were reviewed.ResultsAchondroplasia was the most common skeletal dysplasia (8), followed by Chondrodysplasia punctata (7) and Spondyloepiphyseal dysplasia (5). There were fourteen men and eight women with mean age of 51 years (28 to 73). The average height of patients was 1.4 metres (1.16–1.75) and the mean weight was 64.8 Kg (34.3–100). The mean follow up duration was 68.32 months (1–161). Three patients died during follow up. Custom implants were required in twelve patients (38.71%). Custom jigs were utilised in six patients and two patients underwent robotic assisted surgery. Hinged TKR was used in seventeen patients (54.84%), posterior stabilised TKR in nine patients (29.03%), and cruciate retaining TKR in five patients (16.13%). One patient underwent a patella resurfacing for persistent anterior knee pain and another had an intra-operative medial tibial plateau fracture which was managed with fixation. No revisions occurred during the follow up period.ConclusionDespite the technical challenges and complexity of TKR within this unique patient group, we demonstrate good implant survivorship during the study period. Cross sectional imaging is recommended preoperatively for precise planning and templating.

Aim Mega-endoprosthesis over the last two decades have played a significant role in management of non-neoplastic cases for limb salvage for a variety of indications involving bone loss, infection, fracture and failed revision surgery. This is a retrospective case control study comparing outcomes of Mega-Endoprosthesis (MEP) in non-neoplastic cases with periprosthetic joint infections (PJI), with previous history of PJI and aseptic revision. Failure was defined as persistence/recurrence of infection, all cause revision, and antibiotic suppression during the follow up period. Secondary aims were identification of causative organisms, resistance profile and causative factors for revision surgery. Method A total of 122 patients undergoing 133 MEPs were identified between January 2012 and December 2020. 60 procedures were categorised as group 1 (infection; 50%), 20 as group 2 (previous history of infection; 16.7%), and 53 controls (no infection; 44.2%). Mean age of the cohort was 70.97 years (37.16–94.17), with a mean follow-up of 44.5 months (0.2–179) including patients lost to follow up. Results Overall failure rate was 71/133 53.3% (group 1 39/60 (55.56%), group 2 12/20 (60%) and controls 20/53 (37.7%)). Thirteen patients died in the first 2 years (five in group 1, one in group 2 & seven in controls). The most common postoperative infection was polymicrobial followed by Coagulase Negative Staphylococcus Species (CoNS) and Methicillin Sensitive Staphylococcus aureus (MSSA). Nineteen patients had polymicrobial PJI (Eighteen in group 1 and one in control). CoNS led to postoperative infection in Fifteen patients (six in group 1, five in group 2 and four in control group). MSSA was the pathogen in four patients (three in group-1 and one in the control group). The same organisms were responsible for recurrent infection in fourteen patients in group 1 and one patient in group 2. Limb salvage was achieved in 96.2% overall (95% group 1, 90% group 2, 100% control group). Conclusions MEPs in the context of PJI have a significant risk of failure however they play an important role in limb salvage. Patients should be counselled appropriately prior to surgery.

AbstractBackgroundAutologous chondrocyte implantation is a NICE approved intervention however it involves the morbidity of two operations, a prolonged rehabilitation and substantial healthcare costs. This study describes a novel, one-step, bone marrow (BM) derived mesenchymal stem cell (MSC) transplantation technique for treating knee osteochondral lesions and presents our prospective clinical study investigating the success of this technique in 206 lesions over a 5 year period.MethodologyThe surgical technique involves harvesting BM from patients’ anterior superior iliac spines, centrifugation to isolate MSCs and seeding into a type 1 collagen scaffold (SyngenitTM Biomatrix). Autologous fibrin glue is used to secure the scaffold into the defect. Inclusion criteria included patients aged 15 – 55 years old with symptomatic osteochondral lesions >1cm2. Exclusion criteria included patients with ligament instability, uncorrected alignment, inflammatory arthropathy and a Body Mass Index >35 kg/m2. Outcome measures included the Modified Cincinnati Knee Rating System (MCKRS), complications and reoperations.ResultsMean MCKR scores showed statistically significant improvements compared to pre-operative scores at 6 months 58.79 ± 3.5 and 1 year postoperatively 63.82 ± 3.93 with further improvements at 2 years and 5 years which did not reach statistical significance. Survival rates were 97.9%, 94% and 93.2% at 1, 2 and 5 years. Multiple regression analysis identified previous cartilage surgery, microfracture and age as factors affecting MCKRS scores (p < 0.029, 0.001 and 0.030, respectively).ConclusionsOne-step BM derived stem cell transplantation demonstrates satisfactory outcomes over a 5 year period.

Introduction: Donor-derived cell-free DNA (dd-cfDNA) is validated for allograft surveillance in kidney transplant recipients; however, the utility in patients undergoing pancreas and kidney (PTx) transplantation has not been well studied. Pancreatic rejection remains a major clinical concern, yet diagnosis relies on pancreatic biopsy which is associated with significant risk of procedural complications. Early identification of allograft injury is imperative to optimize treatment and intervention. Here, we describe dd-cfDNA levels in PTx transplant recipients in the setting of clinical stability and immunological events. Methods: PTx recipients were monitored longitudinally with dd-cfDNA (AlloSure, CareDx) at the discretion of the treating physician. dd-cfDNA was collected in tandem with standard of care laboratory testing including serum creatinine, amylase, lipase, DSA and BK PCR. Pancreatic graft dysfunction was defined by elevations in serum amylase/lipase or dysregulated glucose control. The reference population was defined by stable allograft function in the absence of immunological or clinical events. Immunological events were defined as clinically suspected allograft rejection or documented subtherapeutic immunosuppression. Results: A total of 16 PTx patients were monitored longitudinally with dd-cfDNA, including 15 SPK recipients and 1 pancreas after kidney transplant (Table 1). 12 patients met criteria for the stable reference population with a median dd-cfDNA level of 0.22% (IQR 0.12 – 0.36%, n=248). There was a trend towards increased variability in dd-cfDNA levels in the first 2 months post-transplant, after which there was no significant difference in dd-cfDNA stratified by time (Figure 1A). 4 patients developed 6 independent immunological events, which were associated with a significantly increased median dd-cfDNA level of 1.15% (IQR 0.15 – 1.85%) compared to 0.22% in the reference population (p = 0.03, Figure 1B). Conclusions: In stable PTx recipients, dd-cfDNA levels remain low post-transplant and reflect the reference ranges validated in kidney transplant alone. Early variability in dd-cfDNA levels may be explained by recovery from ischemia reperfusion injury. Significant increases in dd-cfDNA were associated with immunological events including clinically suspected allograft rejection, highlighting its utility in longitudinal graft surveillance.

Introduction: Custom acetabular components have become an established method of treating massive acetabular bone defects in hip arthroplasty. Complication rates, however, remain high and migration of the cup is still reported. Ischial screw fixation (IF) has been demonstrated to improve mechanical stability for non-custom, revision arthroplasty cup fixation. We hypothesize that ischial fixation through the flange of a custom acetabular component aids in anti-rotational stability and prevention of cup migration. Methods: Electronic patient records were used to identify a consecutive series of 49 custom implants in 46 patients from 2016 to 2022 in a unit specializing in complex joint reconstruction. IF was defined as a minimum of one screw inserted into the ischium passing through a hole in a flange on the custom cup. The mean follow-up time was 30 months. IF was used in 36 cups. There was no IF in 13 cups. No difference was found between groups in age (68.9 vs. 66.3, P = 0.48), BMI (32.3 vs. 28.2, P = 0.11) or number of consecutively implanted cups (3.2 vs. 3.6, P = 0.43). Aseptic loosening with massive bone loss was the primary indication for revision. There existed no difference in Paprosky grade between the groups (P = 0.1). 14.2% of hips underwent revision and 22.4% had at least one dislocation event. Results: No ischial fixation was associated with a higher risk of cup migration (6/13 vs. 2/36, X-2 = 11.5, P = 0.0007). Cup migration was associated with an increased risk for all cause revision (4/8 vs. 3/38, X-2 = 9.96, P = 0.0016, but not with dislocation (3/8 vs. 8/41, X-2 = 1.2, P = 0.26). Conclusion: The results suggest that failure to achieve adequate ischial fixation, with screws passing through the flange of the custom component into the ischium, increases the risk of cup migration, which, in turn, is a risk factor for revision.

BackgroundAutologous chondrocyte implantation (ACI) is a NICE-approved technique to regenerate hyaline cartilage in chondral and osteochondral defects (OCDs). The drawbacks of ACI include that it requires a two-stage approach, involves a lengthy rehabilitation process and is expensive. Bone marrow harvest with mesenchymal stem cell transplantation using a single-stage procedure and an accelerated rehabilitation programme has been developed to overcome this. The aim of this paper is to describe the surgical technique for stem cell transplantation of the knee for OCDs with reference to case examples.MethodsThe surgical technique for stem cell transplantation of the knee for OCDs is described, with reference to three cases. Magnetic resonance imaging was performed at six months postoperatively.ResultsThe surgical technique is described in this paper. The three patient cases described all improved clinically with reduced pain and improved function at a minimum of six months follow-up.ConclusionsStem cell transplantation has the potential to produce favourable outcomes for patients with osteochondral defects of the knee. This single-stage approach and accelerated rehabilitation is associated with reduced financial costs. A long-term prospective study of this technique is currently underway at our institution and randomised controlled trials are planned to demonstrate the effectiveness over other techniques.

Background: Revision knee replacement (KR) is both challenging for the surgical team and expensive for the healthcare provider. Limited high quality evidence is available to guide decision-making. Aim: To provide guidelines for surgeons and units delivering revision KR services. Methods: A formal consensus process was followed by BASK's Revision Knee Working Group, which included surgeons from England, Wales, Scotland and Northern Ireland. This was supported by analysis of National Joint Registry data. Results: There are a large number of surgeons operating at NHS sites who undertake a small number of revision KR procedures. To optimise patient outcomes and deliver cost-effective care high-volume revision knee surgeons working at high volume centres should undertake revision KR. This document outlines practice guidelines for units providing a revision KR service and sets out: The current landscape of revision KR in England, Wales and Northern Ireland. Service organisation within a network model. The necessary infrastructure required to pro-vide a sustainable revision service. Outcome metrics and auditable standards. Financial mechanisms to support this service model. Conclusions: Revision KR patients being treated in the NHS should be provided with the best care available. This report sets out a framework to both guide and support revision KR surgeons and centres to achieve this aim. Crown Copyright (c) 2021 Published by Elsevier B.V. All rights reserved.

Purpose: COVID-19 infection is associated with 25% mortality in kidney transplant recipients (KTRs). Reduction of anti-metabolite immunosuppressants during the acute COVID-19 illness is a common approach in managing KTRs. This potentially increases the risk of allograft rejection in the setting of reduced immunosuppression. The optimal timing for safe reintroduction of immunosuppression remains unclear. Here we describe a novel approach of incorporating dd-cfDNA to safely titrate immunosuppression in patients with COVID-19. Methods: KTRs were monitored prospectively with dd-cfDNA beginning at the time of COVID-19 diagnosis or on discharge from acute care. If dd-cfDNA 1% or a rapid relative change from baseline, antimetabolites were reintroduced at full dose provided the patient remained symptom free from COVID-19. Results: 58 KTRs (including 1 PAK) with COVID-19 infection were monitored with dd-cfDNA at the time of or following this diagnosis from March 2020 to January 2021. Demographics and directed treatments are summarized in Table 1. Median dd-cfDNA levels remained stable during longitudinal surveillance following COVID-19 (Figure 1A). 3/58 patients with COVID-19 and dd-cfDNA results available developed biopsy-proven rejection. One developed rejection at the time of COVID-19 diagnosis with elevated dd-cfDNA. 2/58 developed rejection in the setting of delayed re-introduction of antimetabolites due to clinical concerns (Figure 1B), however one did not have elevated dd-cfDNA. 10% of patients (n=6) had accelerated reintroduction of anti-metabolites due to dd-cfDNA levels>1% or rapid deviation from baseline. None of these patients developed rejection in the following months and dd-cfDNA levels decreased after immunosuppression reintroduction. Standard reintroduction of anti-metabolites with dd-cfDNA <1% was achieved with no associated episodes of rejection. Conclusions: dd-cfDNA presents a feasible adjunctive biomarker to guide immunosuppression titration in KTRs with confirmed COVID-19 and avoid allograft rejection during a time of increased immunological risk.

Background: Multiply revised total knee arthroplasties (TKAs) may present with large anterior soft tissue defects, which can be challenging to reconstruct. In the rare cases where local flaps are insufficient, we use free latissimus dorsi (LD) myocutaneous flaps to achieve soft tissue coverage. This study looked to determine implant survivorship, infection status, and patient-reported outcomes of patients undergoing simultaneous revision TKA and LD flaps in a tertiary unit. Methods: This was a retrospective study of 18 consecutive patients who had revision TKA and free LD flap reconstruction. Twelve were male and the median age was 65 years (range, 35-83). Patients had undergone a median of 4 previous arthroplasty procedures (range, 3-6). Median follow-up was 49 months (range, 18 to 110). The primary outcome was revision-free implant survival. Secondary outcomes included soft tissue integrity, Oxford Knee Score, and EuroQol 5-domain score at latest follow-up. Results: At latest follow-up, 14 of 18 patients had maintained their implant. Seven patients were infection-free, 7 were on suppressive antibiotics with the implant in situ, and 4 had undergone above-knee amputation. Five-year implant survival was 75% (95% confidence interval, 46-90). At median follow-up (49 months), mean Oxford Knee Score was 13.4 (range, 2-35) and mean EuroQol 5-domain index was 0.071 (range:-0.427 to 0.747). Conclusion: LD free flap is a viable option for limb salvage in patients with large anterior soft tissue defects following multiple revisions of TKA. However, functional outcomes can be poor and there is a significant risk of ongoing infection and amputation in this complex patient cohort. (C) 2020 Elsevier Inc. All rights reserved.