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.

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.

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.

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.

Secuenciación de próxima generación para la detección de patógenos en cirugía de cadera: experiencia y viabilidad diagnóstica en un centro de atención terciaria de la Argentina / Next generation sequencing for the detection of pathogens in hip surgery. Experience and diagnostic feasibility in a tertiary care center in Argentina

Introducción: El diagnóstico rápido y definitivo con identificación del patógeno es fundamental cuando hay una infección periprotésica. La secuenciación de próxima generación permite identificar el ADN en un germen determinado en poco tiempo. Hasta donde sabemos, no hay reportes sobre su empleo para el manejo de la infección periprotésica en Sudamérica. Nuestro objetivo fue demostrar la viabilidad diagnóstica de las muestras obtenidas de una serie de pacientes operados en Buenos Aires, Argentina, y analizadas con la técnica de secuenciación de próxima generación. materiales y métodos: Se analizó a una serie prospectiva de 20 pacientes sometidos a cirugía de revisión séptica y aséptica de cadera desde diciembre de 2019 hasta marzo de 2020. Se obtuvieron muestras intraoperatorias de líquido sinovial, tejido profundo y canal endomedular, que fueron enviadas para su análisis al laboratorio NexGen Microgen. Resultados: Se seleccionaron 17 pacientes, porque tenían una muestra apta para analizar. Los resultados se recibieron dentro de las 72 h de la cirugía. En un caso, el resultado de la secuenciación de próxima generación informó un germen distinto del identificado en los cultivos posoperatorios de partes blandas, esto permitió corregir la antibioticoterapia. En otro, esta técnica identificó Parabacteroides gordonii en una revisión aséptica, en otro, Morganella morganii, a partir de cultivos negativos en una revisión en un tiempo. Conclusión: Se demostró la viabilidad diagnóstica con la secuenciación de próxima generación, se pueden obtener resultados de microorganismos patógenos dentro de las 72 h posteriores a la cirugía en pacientes con infección periprotésica y cultivos negativos. Nivel de Evidencia: IV

Introduction: Early diagnosis of a periprosthetic joint infection (PJI) and identification of the pathogen are paramount. Next-generation sequencing (NGS) can identify the nucleic acids in a given germ in a short period. To our knowledge, there are no reports of its use in the management of PJI in South America. Our objective was to demonstrate the diagnostic feasibility of the NGS technique on the samples obtained from a series of patients operated on in Buenos Aires, Argentina. Materials and methods: A prospective series of 20 patients undergoing septic and aseptic hip revision surgery from December 2019 to March 2020 was analyzed. Intraoperative samples of synovial fluid, deep tissue, and intramedullary canal were obtained and sent to the NexGen Microgen laboratory (Texas, USA) for analysis. Results: Seventeen patients were finally eligible to present a sample suitable for analysis. In 100% of the samples, NGS results were obtained within 72 hours of surgery. In one case, the NGS result reported a germ different from the one identified in the postoperative soft tissue cultures, allowing antibiotic therapy to be corrected. In another case, NGS identified Parabacteroides gordonii in aseptic revision surgery. In another patient, the NGS identified Morganella morganii, in which conventional postoperative cultures were negative in single-stage revision surgery. Conclusion: In this study, we demonstrated the diagnostic feasibility of NGS, obtaining results within 72 hours immediately after surgery for pathogenic organisms in patients with PJI and negative cultures. Level of Evidence: IV

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.

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.

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.

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.

Osteotomía periacetabular de Ganz para el tratamiento de la displasia del desarrollo de la cadera: experiencia inicial y resultados de los primeros 44 casos / Ganz periacetabular osteotomy for the treatment of developmental dysplasia of the hip. Initial experience and results from the first 44 cases

Objetivo: Describir la técnica quirúrgica, las indicaciones y los resultados iniciales de la osteotomía periacetabular bernesa para tratar la displasia del desarrollo de la cadera. Materiales y métodos: Entre mayo de 2011 y mayo de 2020, se realizaron 44 osteotomías periacetabulares bernesas en 44 pacientes (35 mujeres, edad promedio 30 años [rango 23-38]). Todos tenían diagnóstico de displasia de cadera sintomática. El ángulo centro-borde promedio fue de 17° (rango 9°-20°) y el índice acetabular promedio, de 18° (rango 15°-20°). En 22 casos, se evaluaron y repararon los hallazgos intrarticulares por artroscopia en el mismo acto quirúrgico. Se evaluaron la corrección obtenida, la consolidación de la osteotomía y los resultados funcionales al final del seguimiento. Resultados: En 22 pacientes, se detectó hipertrofia y rotura del labrum acetabular asociadas a displasia de cadera. Diez pacientes tenían quistes paralabrales. El ángulo centro-borde promedio posoperatorio fue de 32° (rango 27°-35°) y el índice acetabular, de 6° (rango 4°-9°). El tiempo quirúrgico para la osteotomía periacetabular bernesa fue de 130 min, cuando se sumó un procedimiento artroscópico, el tiempo fue de 148 minutos. Conclusiones: La osteotomía periacetabular bernesa es técnicamente demandante, pero logra resultados predecibles en pacientes con integridad del cartílago articular y deformidades corregibles. La artroscopia antes de la osteotomía permite evaluar las condiciones del cartílago, diagnosticar y tratar lesiones intrarticulares asociadas con esta enfermedad y decidir si es necesaria la corrección del déficit de cobertura. Nivel de Evidencia: IV

Objective: To describe the surgical technique, indications, and initial results of the Bernese periacetabular osteotomy (PAO) for the treatment of developmental dysplasia of the hip. Materials and methods: Between May 2011 and May 2020, 44 PAOs were performed in 44 patients (35 women) with an average age of 30 years (23-38). All patients had a diagnosis of symptomatic hip dysplasia. The average center-edge angle was 17° (9° to 20°) and the average acetabular index was 18° (15° to 20°). In 22 cases, the intra-articular findings were evaluated and repaired by arthroscopy in the same surgical stage. The correction obtained, the consolidation of the osteotomy, and the functional outcomes at the end of the follow-up were evaluated. Results: Hypertrophy and rupture of the acetabular labrum associated with hip dysplasia were evidenced in 22 patients. Paralabral cysts were found in 10 patients in the series. The average postoperative center-edge angle was 32° (27° to 35°) and the acetabular index was 6° (4° to 9°). The surgical time for PAO was 130 minutes; in patients where an arthroscopic procedure was added, the time was 148 minutes. Conclusions: PAO is technically demanding, but has predictable outcomes in patients with articular cartilage integrity and correctable deformities. Arthroscopy before osteotomy allows assessing cartilage conditions, diagnosing and treating intra-articular lesions associated with this pathology, and deciding on the need to correct the soft tissue deficit. Level of Evidence: IV

¿Qué factores hacen fallar un reimplante de cadera luego de una revisión en dos tiempos? / What factors cause hip reimplantation to fail after a two-stage revision hip arthroplasty?

Introducción: El objetivo del estudio fue analizar la supervivencia sin recurrencia de infección en pacientes con reemplazo total de cadera tratados con revisión en dos tiempos, valorando el impacto del cultivo intraoperatorio y la congelación positiva en el reimplante. materiales y métodos: Estudio retrospectivo de 96 casos con infección periprotésica crónica, según los criterios de la MusculoSkeletal Infection Society, sometidos a los dos tiempos quirúrgicos en nuestra institución, entre 2008 y 2013. El seguimiento promedio fue 90 meses. La falla séptica se definió sobre la base de un consenso tipo Delphi modificado. La supervivencia sin falla séptica se definió sobre la base del estimador de Kaplan-Meier. Se compararon los resultados de supervivencia en función del cultivo intraoperatorio y de los estudios de anatomía patológica por congelación mediante la prueba del orden logarítmico. Resultados: La supervivencia sin falla séptica fue del 82,65% a los 2 años (IC95% 73,25-88,99%), 80,40% a los 5 años (IC95% 70,70-87,17%) y 77,32% a 6-10 años (IC95% 66,90-84,33%). Hubo significativamente más fallas en los pacientes con un cultivo positivo en el reimplante que en aquellos con un cultivo negativo (prueba del orden logarítmico, p = 0,0208), y en quienes tuvieron un estudio anatomopatológico por congelación positivo en el reimplante que en aquellos con un resultado negativo (prueba del or-den logarítmico, p = 0,0154). Conclusiones: Los reimplantes sin recurrencias infecciosas por, al menos, 6 años tuvieron un riesgo de falla séptica muy bajo. Cuando se detectó un cultivo o una congelación positivos, la falla séptica fue significativamente mayor. Nivel de Evidencia: IV

Background: We analyzed the survivorship free-from-septic failure in a series of THA cases treated with a two-stage protocol at long-term follow-up, with a special focus on the relevance of positive frozen section and positive intraoperative culture taken during the reimplantation. Materials and methods: We retrospectively reviewed data from 96 cases who met the Musculoskeletal Infec-tion Society criteria for periprosthetic joint infection and who had undergone both stages of a two-stage protocol at our institution between 2008-2013. Mean follow-up was 90 months. Treatment failure was determined with a modified Delphi-based consensus definition. Kaplan-Meier estimate was used to determine survivorship free-from-septic failure. Log-Rank test was used to compare variables associated with septic failure. Results: Survival free-from-septic failure was 82.65% at 2 years (95%CI 73.25%-88.99%), 80.40% at 5 years (95%CI 70.70%-87.17%) and 77.32% at 6-10 years (95%CI 66.90%-84.33%). Patients with a positive culture at reimplantation had significantly more septic failures than those without it (Log-Rank test, p=0.0208), while patients with a positive frozen section at reimplantation had significantly more septic failures than those without it (Log-Rank test, p=0.0154). Conclusions: Reimplantations that remained at least 6 years without septic recurrences had a very low risk of further septic failure. Both positive frozen section and intraoperative culture at reimplantation were risk factors for septic failure. Level of Evidence: IV

Artrosis rápidamente progresiva de cadera secundaria a una fractura por insuficiencia subcondral del acetábulo. Reporte de un caso / Rapidly progressive osteoarthritis of the hip secondary to a subchondral insufficiency fracture of the acetabulum: A case report

Las fracturas por insuficiencia subcondral son una causa poco frecuente de cadera dolorosa. A diferencia de las fracturas traumáticas agudas, las fracturas por insuficiencia del acetábulo son menos frecuentes que las femorales. Ocurren habitualmente en mujeres posmenopáusicas con comorbilidades. Su diagnóstico inicial suele ser dificultoso y la sospecha clínica es de gran importancia. La resonancia magnética es una herramienta fundamental para detectar este cuadro. Subestimar estas lesiones puede llevar al desarrollo de una artrosis rápidamente progresiva y al reemplazo articular como desenlace. Se presenta el caso de una paciente de 68 años con una fractura por insuficiencia subcondral del acetábulo a quien se le indicó una artroplastia total de cadera no cementada. Nivel de Evidencia: IV

Subchondral insufficiency fractures are a rare cause of hip pain. Unlike acute traumatic fractures, acetabulum insufficiency fractures are less common than femoral fractures. They commonly occur in postmenopausal women with comorbidities. Its initial diagnosis is usually difficult and clinical suspicion is of great importance. Magnetic resonance imaging (MRI) is a fundamental tool for the detection of this pathology. Underestimating these injuries can lead to the development of rapidly progressive osteoarthritis and joint replacement as an outcome. We present the case of a 68-year-old patient with a subchondral insufficiency fracture of the acetabulum who underwent uncemented total hip arthroplasty. Level of Evidence: IV

Who Restores Hip Biomechanics More Effectively after a Femoral Neck Fracture? Comparison of Total Hip Arthroplasties Performed by Either Hip Surgeons or Orthopaedic Residents.

BACKGROUND: This study aims to analyze the ability to restore hip biomechanics in patients who undergo total hip arthroplasty for displaced femoral neck fractures operated by either hip surgeons (HSs) or orthopaedic residents (ORs). METHODS: We retrospectively compared 95 patients treated by HSs (group A) with 110 patients treated by ORs (group B). Leg-length discrepancy, femoral offset (FO), center of rotation (COR), acetabular inclination, and acetabular anteversion were evaluated on postoperative radiographs using the healthy contralateral hip as control. RESULTS: The median leg-length discrepancy was 2 mm for both groups (P = .74). The leg length was increased in 54% of the HS group and 57% of the OR group (P = .13). The median FO difference of groups A and B were 7 mm and 5.5 mm, respectively (P = .14). FO was increased in 80% of the HS group and 69% of the OR group (P = .19). Median discrepancies of the horizontal and vertical CORs were not statistically relevant, with P-values of .69 and .14, respectively. The horizontal COR was slightly medialized in 58% of the HS group and 53% of the OR group (P = .003). The vertical COR was slightly proximal in 66% of the HS group and 76% of the OR group (P = .28). The median acetabular inclination angles of groups A and B were 41° and 40°, respectively (P = .62). The median anteversion angle was 19° for both groups (P = .89). CONCLUSIONS: The horizontal COR was the only measurement with statistical significance. To conclude, ORs under supervision are as reliable as HSs to properly restore hip biomechanics in patients who undergo total hip arthroplasty for displaced femoral neck fractures.

Conversion total hip arthroplasty with a proximally modular, distal fixation reconstruction prosthesis following cephalomedullar nail failure.

BACKGROUND: The goals of intertrochanteric hip fracture (IHF) treatment are stable fixation, early mobilisation and function restoration. If the attempt to reduce, stabilise and fracture healing utilising a femoral cephalomedullar nail (CMN) fails, options for subsequent attempts are limited. PURPOSE: Evaluate the clinical and radiographic outcomes of conversion total hip arthroplasty (THA) using a modular stem following a CMN failure. MATERIALS AND METHODS: We retrospectively reviewed a consecutive series of patients with an IHF between 2012 and 2014 to identify CMN patients that went on to the subsequent failure and conversion to THA utilising a modular femoral stem (MFS). In all cases, MP Reconstruction Prosthesis (Waldemar Link, Hamburg, Germany) was implanted. Primary clinical outcomes were assessed using Harris Hip Score (HSS) before conversion procedure, 3 months, 6 months and recent office visit post-conversion THA thereafter. The secondary outcome was to analyse intra and postoperative complications. Serial radiographs at each follow-up interval were assessed for clinical success or to confirm adverse events. RESULTS: 28 patients were included in the study; 17 were females. The average age was 72.7 years (SD ± 10.5); the average time from the index procedure to conversion THA was 12.6 months (SD ± 3.5). At baseline, average HHS was 42.1 (SD ± 3.6), improved to 80.7 (SD ± 5.1) at 3 months, 86.0 (SD ± 3.9) at 6-months which levelled off to 86.1 (SD ± 4.0) at final follow-up. There were 4 (14%) post-conversion complications: 2 dislocations, 1 superficial wound infection, 1 patient with symptomatic abductor deficiency. All 4 cases were conservatively treated successfully, the implants were retained, and the patients progressed without further issue. CONCLUSIONS: MFSs allow to successfully treat failed CMN and adverse variations in femoral anatomy with a device that will permit simultaneous correction of leg length, offset and version to relieve pain, restore function and create a durable prosthetic to host composite.

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.

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.

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.

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.

Reemplazo total de cadera con un tallo corto no cementado tipo 2B: resultados a los 2-5 años de seguimiento / Hip replacement with a type 2B cementless short stem. Results of 2 to 5 years of follow-up

Objetivo: Determinar los resultados clínicos, la supervivencia y la incidencia de fractura periprotésica intraoperatoria con un tallo corto tipo 2B de fijación cervicometafisaria. Materiales y Métodos: Se analizaron prospectivamente los primeros 100 tallos (84 pacientes) MiniHipTM (Corin, Cirencester, Reino Unido) colocados, en forma consecutiva, por un mismo cirujano. La edad promedio fue de 47 años. La indicación para un tallo corto fue: edad <55 años (85 casos) o la participación previa en deportes de impacto en pacientes de entre 56 y 60 años (15 casos). El diagnóstico inicial fue artrosis primaria de cadera en el 82% de los casos. El seguimiento promedio fue de 42 meses. Resultados: El puntaje en la escala de Harris modificada mejoró de 55 a 96 al final del seguimiento (p = 0,02) y ningún paciente refirió dolor de muslo en el posoperatorio. La supervivencia del tallo fue del 99% (IC95% 93,1-99,8). Un caso presentó una perforación de la cortical lateral intraoperatoria, tratado con revisión con un tallo no cementado convencional. Un paciente tuvo una infección aguda, que fue tratada con desbridamiento, retención de componentes y antibióticos, con resultado favorable a los 48 meses de la cirugía. Se produjeron 3 fracturas incompletas del calcar intraoperatorias (3%). Conclusiones: Se obtuvieron resultados excelentes en esta serie de pacientes jóvenes y activos operados por un mismo cirujano con un tallo corto tipo 2B, a los 2-5 años de seguimiento, con un 1% de falla por falsa vía femoral intraoperatoria. Nivel de Evidencia: IV

Objective: We aimed to determine 2- to 5-year survivorship rate, intraoperative fractures, subsidence and thigh pain rate in a consecutive, independent, one-surgeon series of surgical patients in whom a type 2B short stem was implanted. Methods: We reviewed the first 100 type 2B consecutive femoral short stems implanted in 84 patients with a mean age of 47 years old. Indications included age younger than 55 years (85 hips), or participation in impact sports in patients aging 56 to 60 years old (15 hips). Initial diagnosis was osteoarthritis in 82% of the cases. Median follow-up was 42 months. Results: Stem survivorship rate was 99% at 2 to 5 years followed by stem revision for any aseptic reason, and 98% when infection played a part. Mean Harris Hip Score improved significantly from 55 to 96 at final follow-up (p 0.02). There was one lateral cortex perforation, and three intra-operative calcar partial fractures (3%), only one of them required cerclage wiring and delayed weight-bearing. No patient referred thigh pain at final follow-up. Only one case subsided 4 mm, but then stabilized. The risk of revision was 1% after 2 to 5 years (95%CI 93.1-99.8%). Conclusions: We obtained promising short-term results with this device in this single-surgeon, non-consecutive series -including the learning curve period- using a type 2B short stem in young active patients-, in which bone preservation is warranted. Level of Evidence: IV