Do nonagenarians have more complications and unplanned readmissions than octogenarians following primary THA? A retrospective cohort study.

INTRODUCTION: The performance of total hip arthroplasty in elderly patients, especially nonagenarians, is challenging due to higher patient frailty and medical comorbidities. We compared 90-day postoperative complications and unplanned readmissions between nonagenarians and octogenarians undergoing elective THA. METHODS: One hundred and eleven patients undergoing elective, unilateral THA were retrospectively analyzed. Forty-four patients were nonagenarians (Group A), and 67 patients were octogenarians (Group B). Demographic data included age, gender, body mass index (BMI), ASA score and Charlson Comorbidity Index (CCI). Frailty was defined according to the Rockwood Frailty Index. All patients underwent a thorough preoperative assessment through a specific institutional clinical pathway created for this matter. Postoperative adverse events were grouped into major or minor. A regression model was used to evaluate independent risk factors for the development of complications. RESULTS: There were no differences in the ASA score (65.9% vs. 53.7% ASA III-IV), prevalence of frailty (1% vs. 9%) and comorbidities between both groups (p > .05). The CCI was higher in nonagenarians (p = 0.007). Nonagenarians had more in-hospital complications, although most were minor (p = 0.002), none of which resulted in mortality. Ninety-day unplanned readmissions were similar between groups, with 4 (9.1%) and 6 (9%) in groups A and B, respectively (p = 1). Although age was a factor associated with the development of postoperative complications in the univariate regression model (OR 3.81, 95% CI 1.31 to 11.11, p = 0.014), it lost significance after performing the multivariate analysis (OR 2.48, 95% CI 0.78 to 7.90, p = 0.125). CONCLUSION: The age of 90 years old was not a barrier to perform elective THA safely. Nonagenarians had higher in-hospital minor complications when compared to the younger cohort. However, age over 90 years was not an independent risk factor for unplanned readmissions or mortality. Multimodal protocols of perioperative care are paramount for improving outcomes after THA in very old patients.

Preliminary outcomes of the cementless UNITED hip system for primary total hip arthroplasty at a minimum 2-year follow-up.

INTRODUCTION: This study aimed to report the initial results of the cementless UNITED hip system in primary total hip arthroplasty (THA) with a minimum follow-up of 2 years. METHODS: We retrospectively studied a consecutive series of 203 cementless THAs in 180 patients operated between 2015-2017. We included 89 female and 91 male patients with a mean age of 67 (28 to 89) years. The mean follow-up was 40 (29 to 62) months. Clinical outcome scores and radiographs were measured. Survival was calculated defining failure as the need for any further femoral or acetabular revision, irrespective of the reason. RESULTS: No femoral component loosening was detected. One patient had a Vancouver-B1 intraoperative periprosthetic femoral fracture treated with implant retention and cerclage wires. Two acetabular components were revised for aseptic loosening. Three patients suffered an acute infection treated with debridement, antibiotics, and implant retention. The mean Merle d'Aubigné et Postel scores improved from 13 (4 to 16) points preoperatively to 17 (12 to 18) points at the latest follow-up (p < 0.001). At a mean time of 40 months of follow-up, the survival was 99% and 100% for the acetabular and the femoral components, respectively. CONCLUSION: This cementless design showed excellent preliminary outcomes in terms of fixation and patient satisfaction, comparable to that of other well-known similar systems.

Unaddressed arterial injuries in revision total hip arthroplasty: mortality outcomes of a low-prevalence complication.

PURPOSE: Peri-operative major arterial haemorrhage after revision total hip arthroplasty (RTHA) is an odd but limb- and life-threatening complication. In this retrospective analysis, we sought to determine the prevalence of such injuries requiring selective catheter embolization or bypass after RTHA and to evaluate the associated mortality rate. METHODS: Between 1995 and 2016, 2524 RTHAs were performed at a high-volume centre (1031 one-stage revisions, 1370 two-stage revisions and 123 resection arthroplasties). Throughout this period, nine patients presented with signs of persistent bleeding unaddressed during index surgery (9/2524; 0.35%), causing haemodynamic instability. All patients underwent angiographic exploration within the first 24 post-operative hours. Angiography evidenced four cases of bleeding pseudoaneurysms (three of them related to the common femoral artery and one to the medial circumflex femoral artery) and five cases of direct lacerations (one case in the inferior epigastric artery, one in the hypogastric artery, one in the external iliac artery, one in the popliteal artery and another in the superior gluteal artery). RESULTS: Six cases underwent selective percutaneous angiographic embolization with gelatin microspheres, obtaining immediate haemodynamic stabilization; whereas three cases required a further bypass surgery with synthetic graft. Of the former group, four patients had an uneventful evolution, while two died at a mean of 49 days after surgery due to multi-organ failure (MOF). Two cases of the bypass group died because of MOF at a mean of 22 days. Overall mortality rate was 44%. CONCLUSIONS: The overall risk of arterial injury associated with RTHA was low. However, recognition of such a complication is imperative since it was associated with a high mortality rate.

Prolonged social lockdown during COVID-19 pandemic and hip fracture epidemiology.

PURPOSE: To analyse the impact of prolonged mandatory lockdown due to COVID-19 on hip fracture epidemiology. METHODS: Retrospective case-control study of 160 hip fractures operated upon between December 2019 and May 2020. Based on the date of declaration of national lockdown, the cohort was separated into two groups: 'pre-COVID time' (PCT), including 86 patients, and 'COVID time' (CT), consisting of 74 patients. All CT patients tested negative for SARS-CoV-2. Patients were stratified based on demographic characteristics. Outcome measures were 30-day complications, readmissions and mortality. A logistic regression model was run to evaluate factors associated with mortality. RESULTS: Age, female/male ratio, body mass index and American Society of Anaesthesia score were similar between both groups (p > 0.05). CT patients had a higher percentage of Charlson ≥ 5 and Rockwood Frailty Index ≥ 5 scores (p < 0.05) as well as lower UCLA and Instrumental Activities of Daily Living scores (p < 0.05). This translated into a higher hemiarthroplasty/total hip arthroplasty ratio during CT (p = 0.04). Thromboembolic disease was higher during CT (p = 0.02). Readmissions (all negative for SARS-CoV-2) were similar between both groups (p = 0.34). Eight (10.8%) casualties were detected in the CT group, whereas no deaths were seen in the control group. Logistic regression showed that frailer (p = 0.006, OR 10.46, 95%CI 8.95-16.1), less active (p = 0.018, OR 2.45, 95%CI 1.45-2.72) and those with a thromboembolic event (p = 0.005, OR 30, 95%CI 11-42) had a higher risk of mortality. CONCLUSION: Despite testing negative for SARS-CoV-2, CT patients were less active and frailer than PCT patients, depicting an epidemiological shift that was associated with higher mortality rate.

Impaction Bone Grafting or Uncemented Modular Stems for the Treatment of Type B3 Periprosthetic Femoral Fractures? A Complication Rate Analysis.

BACKGROUND: Because the gold standard for the treatment of Vancouver type-B3 periprosthetic femoral fractures (PFFs) is yet to be defined, we sought to analyze the complication rate between the impaction bone grafting (IBG) technique with a cemented stem and reconstruction with an uncemented distally-fixed modular stem (DFMS). METHODS: We retrospectively studied 54 B3 PFFs operated between 2000 and 2016, comparing the complication rate of 33 patients treated with the IBG technique (group A) with 21 patients treated with a DFMS (group B). Median follow-up of groups A and B were 75 months (interquartile range [IQR], 36-111 months) and 55 months (IQR, 32-73 months), respectively (P = .008). Median age of groups A and B were 78 years (IQR, 74-83 years) and 81 years (IQR, 74-86 years), respectively (P = .30). Median grade of Endo-Klink femoral bone defect was 3 (IQR, 3-3) for both groups (P = .11). We performed a multiple regression analysis to determine risk factors for complications including the following variables: age, initial diagnosis, and surgical technique. RESULTS: As for infection outcomes, 2-stage revision surgery was more frequent in group A than in group B (4 vs 0, P = .003). Group A presented more implant failures than group B (5 vs 1, P = .195). We found 4 dislocations in group B and 2 in group A (P = .192). Multiple regression analysis showed a significant association between surgical technique and complication rate (P = .01). The IBG technique presented an odds risk for complications of 4.77 (P = .016; IQR, 1.33-17.21). CONCLUSION: Femoral reconstruction with the IBG technique evidenced an ostensibly higher complication rate than that of DFMS for the treatment of B3 PFF.

Aggressive granulomatosis of the hip: a forgotten mode of aseptic failure.

PURPOSE: It has been acknowledged that implant wear correlates with the risk for periprosthetic osteolysis, being aggressive granulomatosis the worst expression of bone resorption. We sought to determine the clinical, radiological, and histological features of aggressive granulomatosis after primary total hip arthroplasty (THA). METHODS: We included nine cases with aggressive granulomatosis of the hip around cemented stems. Indications for revision THA consisted of progressive signs of extensive bone resorption or implant loosening. Mean follow-up since revision THA was 143 months (SD ± 59.4). We analysed clinical outcomes, component loosening and gross as well as histological characteristics of the granulomatous lesions. RESULTS: Overall mean time between primary THA and revision surgery was 81 months (SD ± 20.8). All of the cases evidenced multiple ovoid tumour-like lesions around the stem with extensive bone loss. Only one case reported thigh pain before revision surgery, with radiological evidence of stem loosening; the remaining cases were asymptomatic with well-fixed implants. Gross anatomy findings revealed metallosis in the femoral canal and inside the cystic lesions. Pathology analysis showed monocyte-macrophage-dominated adverse foreign-body-type tissue reaction with fibroblastic reactive zones and granulomatous inflammation. CONCLUSIONS: We found a prevalence of 1% of this aseptic mode of implant failure. Since most of the retrieved stems were not loose, we did not find any alarming clinical symptoms anticipating implant failure. In this scenario, surgeons should be aware of the rapidly progressive nature of this entity and propose a revision THA in a timely fashion.

Re-admissions treble the risk of late mortality after primary total hip arthroplasty.

BACKGROUND: Following a total hip arthroplasty (THA), early hospital re-admission rates of 3-11% are considered as 'acceptable' in terms of medical care cost policies. Surprisingly, the impact of re-admissions on mortality has not been priorly portrayed. Therefore, we sought to determine the mortality rate after 90-day re-admissions following a THA in a series of patients from a captive medical care program. PATIENTS AND METHODS: We prospectively analysed 90-day readmissions of 815 unilateral, elective THA patients operated upon between 2010 and 2014 whose medical care was the one offered by our institution. We stratified our sample into readmitted and non-readmitted cohorts. Through a Cox proportional hazards model, we compared demographic characteristics, clinical comorbidities, surgical outcomes and laboratory values between both groups in order to determine association with early and late mortality. RESULTS: We found 37 (4.53%) re-admissions at a median time of 40.44 days (IQR 17.46-60.69). Factors associated with re-admission were hospital stay (p = 0.00); surgical time (p = 0.01); chronic renal insufficiency (p = 0.03); ASA class 4 (p = 0.00); morbid obesity (p = 0.006); diabetes (p = 0.04) and a high Charlson index (p = 0.00). Overall mortality rate of the series was 3.31% (27/815). Median time to mortality was 455.5 days (IQR 297.58-1170.65). One-third (11/37) of the re-admitted patients died, being sepsis non-related to the THA the most common cause of death. After adjusting for confounders, 90-day re-admissions remained associated with mortality with an adjusted HR of 3.14 (CI95% 1.05-9.36, p = 0.04). CONCLUSIONS: Unplanned re-admissions were an independent risk factor for future mortality, increasing three times the risk of mortality.

Primary Total Hip Arthroplasty With Fourth-Generation Ceramic-on-Ceramic: Analysis of Complications in 939 Consecutive Cases Followed for 2-10 Years.

BACKGROUND: Delta ceramics may be the bearing of choice for younger and active patients due to its improved toughness and wear characteristics, provided there is no risk of fracture. However, ceramic fracture is the most serious complication related to this type of bearing. Although millions of Delta ceramics have been implanted worldwide, short to midterm results have been scarcely reported in the literature. The purpose of this study was to report the complication rate at short to midterm follow-up associated with the bearing surface used in a series of primary total hip arthroplasties with Delta ceramic-on-ceramic bearings performed in a single institution. METHODS: A total of 939 cases (880 patients) undergoing primary total hip arthroplasty with fourth-generation Delta ceramic-on-ceramic bearings were retrospectively reviewed. They were followed for an average of 5.3 years (2-10 years). RESULTS: One hip experienced a liner fracture, 2 cups presented early loosening due to friction between the acetabular screw and the backside of the liner, one femoral ball head had a fracture; one case of squeaking was reported, which is impending revision. Considering revision or impending revision in relationship with the bearing surface as the end point, the mean survival rate was 99.3% (confidence interval 95%, 98.3%-99.7%) at 2-10 years. CONCLUSION: This study showed a low rate of ceramic fracture compared with others; however, it was much higher than the complication rate presented by the manufacturers. The complications observed were directly related to technical errors that surgeons should avoid when using this type of surface.

Intraoperative synovial C-reactive protein is as useful as frozen section to detect periprosthetic hip infection.

BACKGROUND: Synovial quantification of C-reactive protein (SCRP) has been recently published with high sensitivity and specificity in the diagnosis of periprosthetic joint infection. However, to our knowledge, no studies have compared the use of this test with intraoperative frozen section, which is considered by many to be the best intraoperative test now available. QUESTIONS/PURPOSES: We asked whether intraoperative SCRP could lead to comparable sensitivity, specificity, and predictive values as intraoperative frozen section in revision total hip arthroplasty. METHODS: A prospective study was performed including 76 patients who underwent hip revision for any cause. SCRP quantification (using 9.5 mg/L as denoting infection) and the analysis of frozen section of intraoperative samples (five or more polymorphonuclear leukocytes under high magnification in 10 fields) were performed in all the patients. The definitive diagnosis of an infection was determined according to the Musculoskeletal Infection Society (MSIS). In this group, 30% of the patients were diagnosed with infection using the MSIS criteria (23 of 76 patients). RESULTS: With the numbers available, there were no differences between SCRP and frozen section in terms of their ability to diagnose infection. The sensitivity of SCRP was 90% (95% confidence interval [CI], 70.8%-98.6%), the specificity was 94% (95% CI, 84.5%-98.7%), the positive predictive value was 87% (95% CI, 66.3%-97%), and the negative predictive value was 96% (95% CI, 87%-99.4%); the sensitivity, specificity, positive predictive value, and negative predictive value were the same using frozen sections to diagnose infection. The positive likelihood ratio was 16.36 (95% CI, 5.4-49.5), indicating a low probability of an individual without the condition having a positive test, and the negative likelihood ratio was 0.10 (95% CI, 0.03-0.36), indicating low probability of an individual without the condition having a negative test. CONCLUSIONS: We found that quantitative SCRP had similar diagnostic value as intraoperative frozen section with comparable sensitivity, specificity, and predictive value in a group of patients undergoing revision total hip arthroplasty. In our institution, SCRP is easier to obtain, less expensive, and less dependent on the technique of obtaining and interpreting a frozen section. If our findings are confirmed by other groups, we suggest that quantitative SCRP be considered as a viable alternative to frozen section. LEVEL OF EVIDENCE: Level I, diagnostic study.

Medium-term outcomes of conventional versus short uncemented femoral stems for primary total hip arthroplasty in patients younger than 55 years.

BACKGROUND: Short stems are designed with a bone preservation philosophy in mind. This study aims to compare the outcomes/complications and survival of a collarless fully hydroxyapatite (HA)-coated conventional tapered stem and a HA-coated partial neck-retaining uncemented short stem in patients ⩽55 years old at medium-term follow-up. METHODS: We retrospectively studied 247 uncemented THAs operated between 2010 and 2014, comparing 146 patients treated with the fully HA-coated collarless stem (Group A) with 101 patients treated with a partial neck preserving, HA-coated short stem (Group B). 87 and 62 males were in groups A and B, respectively (p = 0.11). The mean age of the series was 46 years (17-55) (p =0.16). The mean follow-up of groups A and B were 9.9 (7-12) years and 9.7 (7-12) years, respectively (p =0.21). RESULTS: Mean Harris Hip Score improved from 55 to 92 in group A (p <0.001) and from 54 to 95 in group B (p <0.001), without differences between groups. Mean femoral neck length preservation in groups A and B was 13.6 (0-28) mm and 26 (11-38) mm, respectively (p =0.001). 13 (8.9%) and 1 (1%) patients in groups A and B presented postoperative complications, respectively (p =0.008). The conventional stem group had more aseptic loosening (Group A 3.4% vs. Group B 0%, p =0.06) along with more Symptomatic radiolucent lines (Group A 3.4% vs. Group B 0%, p =0.06). CONCLUSIONS: Both conventional and short stems showed excellent implant survival rates and functional outcomes at a mean follow-up of 9.8 years. However, complications and radiolucent lines were more frequent with a collarless conventional-length stem. Bone preservation of the femoral neck and diaphysis may be preferred in active young patients.

High failure rate with the GAP II ring and impacted allograft bone in severe acetabular defects.

BACKGROUND: Reconstruction rings and bone allografts have been proposed to manage severe acetabular bone loss. However, a high early failure rate of the Graft Augmentation Prosthesis (GAP) II reinforcement ring (Stryker Orthopaedics, Mahwah, NJ, USA) has been reported in one small series. QUESTIONS/PURPOSES: We therefore determined (1) the survival of this device in combination with impacted morselized allograft bone in patients with severe defects and (2) the complication rate. METHODS: We retrospectively reviewed 24 patients (21 aseptic and three septic) with severe acetabular bone loss (10 hips with Type III defects and 14 with Type IV defects according to the American Academy of Orthopaedic Surgeons classification). We determined function and numbers of failures. The minimum followup was 24 months (mean, 34 months; range, 24-72 months). RESULTS: At latest followup, the reconstruction had failed in nine of the 24 patients: six with aseptic loosening, three with infection. The average postoperative Merle d'Aubigné-Postel score of the patients whose reconstructions had not failed was 16.6 points; at latest followup, these patients had radiographic evidence of incorporation and consolidation of bone allografts. Seven of the nine patients whose reconstructions had failed underwent reoperation. Fatigue fracture of the ring at the plate-cup union occurred in five patients at an average of 45 months postoperatively. All patients with failed reconstructions who underwent reoperation were treated with Trabecular Metal(™) (Zimmer Inc, Warsaw, IN, USA) cups and were functioning well at latest followup. CONCLUSIONS: We observed a high rate (37%) of early catastrophic failures of the GAP II reconstruction ring, particularly in patients with Type IV defects. Due to this high failure rate, we have abandoned its use. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Squeaking in a Delta ceramic-on-ceramic uncemented total hip arthroplasty.

Squeaking is one of the main concerns related to the use of ceramic-on-ceramic total hip arthroplasty. Although it has received much recent publicity, most of the previous reports on this complication have been related to the use of the second generation of alumina ceramics combined with a cup having an elevated metal rim to protect the ceramic liner from neck impingement. We report a patient with a third-generation Biolox Delta (CeramTec AG, Plochingen, Germany) ceramic-on-ceramic uncemented total hip arthroplasty without an elevated metal rim in the cup who presented with a squeaking hip at 23 months postoperative. Although this complication was mainly related to a specific design in the literature, this case demonstrates that newer generation of ceramics can also present squeaking.

Impaction Bone Grafting for Severe Femoral Bone Loss: Surgical Technique in Revision Total Hip Arthroplasty.

Revision total hip arthroplasty in the setting of extensive femoral bone loss poses a considerable challenge to the adult reconstructive surgeon. When the proximal femoral bone stock is deficient or absent, there are few options for reconstruction. In such cases, treatment options include distal cementless fixation (either modular or nonmodular), impaction bone grafting (IBG), a megaprosthesis, or even an allograft-prosthesis composite. Each of these procedures has advantages and disadvantages related to bone preservation, surgical timing, and complexity (depending on the learning curve). For its capacity of restoring bone stock, we have been utilizing the IBG technique at our center since August 1987. The aim of the present article was to describe a step-by-step femoral IBG procedure for severe proximal femoral circumferential bone loss, highlighting its current indications and contraindications. Description: The specific steps to perform this procedure include (1) preoperative planning; (2) positioning of the patient and surgical approach; (3) cautious removal of the previous components; (4) preparation of the bone graft; (5) implantation of the appropriate IBG revision system, restoring bone loss from distal to proximal and utilizing metal mesh as needed; (6) implantation of the new stem, bypassing the defect; and (7) aftercare with protected weight-bearing in order to avoid subsidence of the stem and periprosthetic fracture. Alternatives: There are several alternatives to the IBG technique in the setting of revision total hip arthroplasty with extensive femoral bone loss. These alternatives include distal cementless fixation (either modular or nonmodular), a megaprosthesis, or an allograft-prosthesis composite. Rationale: The rationale for use of the IBG technique is restoration of bone stock. Although this issue may be irrelevant in low-demand elderly patients, we believe it is of the utmost importance among young (i.e., <60 years old) and active patients. This technique is versatile enough to be utilized in different scenarios such as periprosthetic fracture, periprosthetic joint infection (2-stage protocols), and aseptic loosening. Expected Outcomes: We have reported favorable clinical and radiographic outcomes for the treatment of both aseptic and septic femoral component loosening. In all cases, we utilized vancomycin-supplemented impacted cancellous allograft without evidence of secondary effects with regard to bone incorporation, nephrotoxicity, or allergic reactions. Although it was initially contraindicated, we further extended the indication for this reconstruction alternative to cases of circumferential proximal bone loss with non-neoplastic bone defects of ≤15 cm, utilizing encompassing metal mesh and a bypassing long stem. Recently, we reported on poorer outcomes following IBG compared with the use of uncemented modular stems for the treatment of type B3 periprosthetic femoral fractures, with a significantly higher rate of infection and implant breakage for the former treatment. Nowadays, we advocate the use of this technique in young, active patients (i.e., <60 years old) with a femoral bone defect Paprosky grade IIIB or IV, in which reconstitution of bone stock is crucial to avoid an eventual implant failure in the long term. Important Tips: This technique requires an experienced team. This procedure should be avoided in the presence of active periprosthetic joint infection.The gluteus maximus tendon should be detached to avoid tensioning the sciatic nerve and to decrease the chance of periprosthetic femoral fracture.Massive bone loss can jeopardize correct implant orientation and restoration of biomechanics. In this scenario, surgeons might consider the intercondylar axis as a guide for femoral version.Try to avoid (if possible) trochanteric or extended trochanteric osteotomy because proximal bone stock is necessary to contain the bone grafts. In some cases, such as those in which the removal of the stem is difficult, especially with certain uncemented stem designs, an extended trochanteric osteotomy must be performed. Whether or not a cemented stem is removed, it is mandatory to remove all remaining cement in the femoral canal.Preoperative templating is a necessity to reconstruct leg length. Accurately determining the length of the mesh is the most important step to avoid shortening or overlengthening of the lower extremity.Approximately 10 cm of circumferential metal mesh should be fixed with 3 to 5 double cerclage metal wires to the remaining bone. The new femoral stem should bypass extend beyond the mesh for approximately 5 cm. If the stem does not bypass the mesh, there is an increased risk of postoperative fracture.In order to decrease the risk of intraoperative femoral fracture, the distal aspect of the femur should be secured with cerclage wires, and the proximal aspect of the femur should also be protected with cerclage wires over the mesh. As in any other complex femoral revision procedure, torsional forces in the supracondylar zone should be avoided, especially during trial or stem reduction maneuvers.Always utilize a bone graft mixed with antibiotic powder.Retrograde cementation must be done with cement that is in a more liquid state than in primary total hip arthroplasty. Acronyms & Abbreviations: PO = postoperativePMMA = polymethyl methacrylateIV = intravenousLMWH = low molecular weight heparinDVT/EP = deep vein thrombosis and extended prophylaxis.

One-stage exchange should be avoided in periprosthetic joint infection cases with massive femoral bone loss or with history of any failed revision to treat periprosthetic joint infection.

AIMS: There is a paucity of long-term studies analyzing risk factors for failure after single-stage revision for periprosthetic joint infection (PJI) following total hip arthroplasty (THA). We report the mid- to long-term septic and non-septic failure rate of single-stage revision for PJI after THA. METHODS: We retrospectively reviewed 88 cases which met the Musculoskeletal Infection Society (MSIS) criteria for PJI. Mean follow-up was seven years (1 to 14). Septic failure was diagnosed with a Delphi-based consensus definition. Any reoperation for mechanical causes in the absence of evidence of infection was considered as non-septic failure. A competing risk regression model was used to evaluate factors associated with septic and non-septic failures. A Kaplan-Meier estimate was used to analyze mortality. RESULTS: The cumulative incidence of septic failure was 8% (95% confidence interval (CI) 3.5 to 15) at one year, 13.8% (95% CI 7.6 to 22) at two years, and 19.7% (95% CI 12 to 28.6) at five and ten years of follow-up. A femoral bone defect worse than Paprosky IIIA (hazard ratio (HR) 13.58 (95% CI 4.86 to 37.93); p < 0.001) and obesity (BMI ≥ 30 kg/m2; HR 3.88 (95% CI 1.49 to 10.09); p = 0.005) were significantly associated with septic failure. Instability and periprosthetic fracture were the most common reasons for mechanical failure (5.7% and 4.5%, respectively). The cumulative incidence of aseptic failure was 2% (95% CI 0.4 to 7) at two years, 9% (95% CI 4 to 17) at five years, and 12% (95% CI 5 to 22) at ten years. A previous revision to treat PJI was significantly associated with non-septic failure (HR 9.93 (95% CI 1.77 to 55.46); p = 0.009). At the five-year timepoint, 93% of the patients were alive (95% CI 84% to 96%), which fell to 86% (95% CI 75% to 92%) at ten-year follow-up. CONCLUSION: Massive femoral bone loss was associated with greater chances of developing a further septic failure. All septic failures occurred within the first five years following the one-stage exchange. Surgeons should be aware of instability and periprosthetic fracture being potential causes of further aseptic revision surgery. Cite this article: Bone Joint J 2021;103-B(7):1247-1253.

Patients with no recurrence of infection five years after two-stage revision hip arthroplasty may be classified as periprosthetic infection 'in remission'.

AIMS: We aimed to report the mid- to long-term rates of septic and aseptic failure after two-stage revision surgery for periprosthetic joint infection (PJI) following total hip arthroplasty (THA). METHODS: We retrospectively reviewed 96 cases which met the Musculoskeletal Infection Society criteria for PJI. The mean follow-up was 90 months (SD 32). Septic failure was assessed using a Delphi-based consensus definition. Any further surgery undertaken for aseptic mechanical causes was considered as aseptic failure. The cumulative incidence with competing risk analysis was used to predict the risk of septic failure. A regression model was used to evaluate factors associated with septic failure. The cumulative incidence of aseptic failure was also analyzed. RESULTS: There were 23 septic failures at final follow-up, with a cumulative incidence of 14% (95% confidence interval (CI) 8% to 22%) at one year, 18% (95% CI 11% to 27%) at two years, 22% (95% CI 14% to 31%) at five years, and 23% (95% CI 15% to 33%) at ten years. Having at least one positive culture (hazard ratio (HR) 2.38 (interquartile range (IQR) 1.19 to 4.74); p = 0.013), or a positive intraoperative frozen section (HR 2.55 (IQR 1.06 to 6.15); p = 0.037) was significantly associated with septic failure after reimplantation. With dislocation being the most common cause of aseptic revision (5.2%), the cumulative incidence of aseptic failure was 1% (95% CI 0% to 5%) at one year, 6% (95% CI 1% to 8%) at five years, and 8% (95%CI 3% to 17%) at ten years. CONCLUSION: If there is no recurrent infection in the five years following reimplantation, the chances of further infection thereafter are remote. While the results of a frozen section may be a reliable guide to the timing of reimplantation, intraoperative culture has, currently, only prognostic value. Surgeons should be aware that instability remains a potential indication for further revision surgery. Cite this article: Bone Joint J 2021;103-B(1):79-86.

4- to 8-year complication analysis of 2 'partial collum' femoral stems in primary THA.

OBJECTIVES: Compare the clinical and radiological outcome of CFP stem with the MiniHip design in a prospective series, with special interest in intraoperative periprosthetic fracture (IPPF). METHODS: We prospectively followed 101 cases treated with the MiniHip stem (Group 1) and 89 with the CFP stem (Group 2) operated between 2010 and 2014. No significant demographic differences were observed between both groups. Median follow-up was 72 months. Average stem length was 41% shorter in the MiniHip group (p < 0.001). Radiological parameters were measured and a logistcic regression model was created to evaluate factors associated with IPPF. RESULTS: Mean mHHS improved from 54 to 95 in the MiniHip group (p < 0.001) and from 64 to 98 in the CFP group (p < 0.001). No significant differences were observed in terms of loosening, infection or instability. We observed 7 IPPFs (3.68%), 3 in group 1 and 4 in group 2. After adjusting for confounders, CFP was not associated with a greater risk of IPPF (OR 3.23; 95% CI, 0.250-42.034, p = 0.368), however, a more complex fracture pattern was observed with this stem design. Prior acetabular fractures were associated with IPPF (OR 66.85; 95% CI, 1.142-3911, p = 0.043). Compared to Dorr A femurs, type Dorr B appeared protective against IPPF (OR 0.039; 95% CI, 0.001-1.109, p = 0.058). Valgus alignment tended to increase the risk of IPPF (OR 20.59; 95% CI 0.870-487.221, p = 0.061). CONCLUSIONS: MiniHip showed similar radiological outcomes to CFP at short- to mid-term follow-up without increasing IPPFs with a shorter stem length. Given that CFP produced a more complex IPPF pattern, surgeons should be cautious with alignment of this particular design, especially in Dorr A femur.

Selected Vancouver B2 periprosthetic femoral fractures around cemented polished femoral components can be safely treated with osteosynthesis.

AIMS: We aimed to compare the implant survival, complications, readmissions, and mortality of Vancouver B2 periprosthetic femoral fractures (PFFs) treated with internal fixation with that of B1 PFFs treated with internal fixation and B2 fractures treated with revision arthroplasty. METHODS: We retrospectively reviewed the data of 112 PFFs, of which 47 (42%) B1 and 27 (24%) B2 PFFs were treated with internal fixation, whereas 38 (34%) B2 fractures underwent revision arthroplasty. Decision to perform internal fixation for B2 PFFs was based on specific radiological (polished femoral components, intact bone-cement interface) and clinical criteria (low-demand patient). Median follow-up was 36.4 months (24 to 60). Implant survival and mortality over time were estimated with the Kaplan-Meier method. Adverse events (measured with a modified Dindo-Clavien classification) and 90-day readmissions were additionally compared between groups. RESULTS: In all, nine (8.01%) surgical failures were detected. All failures occurred within the first 24 months following surgery. The 24-month implant survival was 95.4% (95% confidence interval (CI) 89.13 to 100) for B1 fractures treated with internal fixation, 90% (95% CI 76.86 to 100) for B2 PFFs treated with osteosynthesis-only, and 85.8% (95% CI 74.24 to 97.36) for B2 fractures treated with revision THA, without significant differences between groups (p = 0.296). Readmissions and major adverse events including mortality were overall high, but similar between groups (p > 0.05). The two-year patient survival rate was 87.1% (95% CI 77.49 to 95.76), 66.7% (95% CI 48.86 to 84.53), and 84.2% (95% CI 72.63 to 95.76), for the B1 group, B2 osteosynthesis group, and B2 revision group, respectively (p = 0.102). CONCLUSION: Implant survival in Vancouver B2 PFFs treated with internal fixation was similar to that of B1 fractures treated with the same method and to B2 PFFs treated with revision arthroplasty. Low-demand, elderly patients with B2 fractures around well-cemented polished femoral components with an intact bone-cement interface can be safely treated with internal fixation. Cite this article: Bone Joint J 2021;103-B(7):1222-1230.

Combining C-reactive protein and interleukin-6 may be useful to detect periprosthetic hip infection.

BACKGROUND: The sensitivity and specificity to detect periprosthetic infection of the different methods have been questioned, and no single laboratory test accurately detects infection before revision arthroplasty. QUESTIONS/PURPOSES: We asked whether preoperative C-reactive protein (CRP) and interleukin-6 (IL-6) could lead to similar sensitivity, specificity, and predictive values as our previous results obtained with intraoperative frozen section (FS) in revision total hip arthroplasty (THA). METHODS: We prospectively followed 69 patients who had undergone revision THA for failure of a primary THA. The definitive diagnosis of an infection was determined on the basis of positive histopathologic evidence of infection or growth of bacteria on culture. RESULTS: Eleven of the 69 hips were infected. The combination of an elevated CRP and IL-6 was correlated with deep infection in all the cases and showed a sensitivity of 0.57 (0.13-1.00), a specificity of 1.00 (0.99-1.00), a positive predictive value of 1.00 (0.87-1.00), and a negative predictive value of 0.94 (0.87-1.00). FS showed a sensitivity of 0.81 (0.54-1.00), a specificity of 0.98 (0.94-1.00), a positive predictive value of 0.90 (0.66-1.00), and a negative predictive value of 0.96 (0.91-1.00). Combining CRP and IL-6 provided similar sensitivity, specificity, and positive predictive values as the FSs. CONCLUSIONS: Our data suggest the combination of CRP and IL-6 would be a useful serologic tool to complement others when diagnosing periprosthetic infection.

Simultaneous Bilateral Femoral Neck Fracture Due to a Tonic-Clonic Seizure and High-Dose Steroid Therapy.

Simultaneous bilateral femoral neck fractures (FNFs) are extremely rare and usually associated with an underlying condition affecting the bone quality and mineralization. Convulsions have also been described as a possible cause, mostly as a consequence of epilepsy, hyponatremia, and hypocalcemia. We present a 52-year-old female patient, with bilateral displaced FNFs due to a tonic-clonic seizure and high-dose steroid therapy related to a frontal lobe anaplastic oligodendroglioma brain tumor resection. Two days after admission, bilateral one-stage uncemented total hip arthroplasty (THA) under general anesthesia and through a posterolateral approach was performed using a metal-on-polyethylene bearing surface. Several risk factors can be identified in this unique case, such as the high-dose steroid therapy, the low-demand activity of the patient due to her functional sequelae, and finally, the convulsive episode. Surgeons should be aware of this uncommon injury to ensure early diagnosis and treatment in all patients with a previous history of seizures, chronic steroid use, severe hip pain, and inability to walk. For bone metabolic diseases, preventive measures should be indicated to avoid these complications. Bilateral one-stage uncemented THA represents an effective procedure with a low complication rate allowing early rehabilitation.