Dislocation and survival rate of dual mobility cups in revision total hip arthroplasty in patients with high risk of instability.

PURPOSE: Instability remains as an unsolved complication after revision total hip arthroplasty (rTHA). Dual mobility (DM) cups have decreased dislocation rate in rTHA; however, there are few clinical studies that evaluate the risk of dislocation after rTHA in patients with high risk of instability. METHODS: Between 2007 and 2019, 95 consecutive rTHA using a DM cup, in 93 patients with instability risk factors were retrospectively reviewed. Instability risk factors were defined as follows: deficient abductor mechanism (22.1%), previous dislocation (68.4%), Paprosky 3 acetabular bone defect (21.1%), neuromuscular disease (4.2%), lumbar spine arthrodesis (6.3%), and more than one previous surgery (33.6%). Mean follow-up was 4.3 ± 2.4 years. Clinical and radiographic parameters were reported. DM cup survival was determined using a Kaplan-Meier analysis with re-revision for any cause as the end-point. Surgical complications and re-dislocation rate was recorded. RESULTS: Seven DM cups were re-revised; three due to aseptic loosening, three due to peri-prosthetic joint infection (PJI), and one due to instability. At seven years follow-up, the survival rate of the DM cup using re-revision for any reason as the end-point was 82.4% (95% confidence interval, 66.4-98.4%). There were 12 (12.6%) complications: two (2.1%) dislocations, six (6.3%) PJI, four (4.2%) peri-prosthetic fractures. CONCLUSION: Our findings suggest DM cups are effective reducing dislocation rate in rTHA in patients with a high risk of instability, without increasing early aseptic loosening and with a low rate of dislocation. Nevertheless, longer follow-up is needed to confirm implant stability and dislocation rates in the long term.

New polyethylenes in total hip arthroplasty : a 20- to 22-year follow-up study.

AIMS: A significant reduction in wear at five and ten years was previously reported when comparing Durasul highly cross-linked polyethylene with nitrogen-sterilized Sulene polyethylene in total hip arthroplasty (THA). We investigated whether the improvement observed at the earlier follow-up continued, resulting in decreased osteolysis and revision surgery rates over the second decade. METHODS: Between January 1999 and December 2001, 90 patients underwent surgery using the same acetabular and femoral components with a 28 mm metallic femoral head and either a Durasul or Sulene liner. A total of 66 hips of this prospective randomized study were available for a minimum follow-up of 20 years. The linear femoral head penetration rate was measured at six weeks, one year, and annually thereafter, using the Dorr method on digitized radiographs with a software package. RESULTS: In the Durasul group, no patients underwent revision due to loosening or showed radiological evidence of osteolysis. In the Sulene group, four patients (four hips) were revised due to femoral component loosening. The 20-year cumulative failure incidence in the presence of the competing event of death for revision surgery was 4.5% (95% confidence interval (CI) 0.8 to 13.6) in the Durasul group, and 8.9% (95% CI 2.8 to 19.5) in the Sulene group. The mean wear one year after surgery was 0.09 mm (SD 0.007) in the Durasul group and 0.24 (SD 0.015) in the Sulene group (p < 0.001). From one to 20 years after surgery, the mean total penetration was 0.32 mm (SD 0.045) in the Durasul group and 1.07 mm (SD 0.13) in the Sulene group (p < 0.001). Mean femoral head penetration at 20 years was approximately 70.0% less in the Durasul group than the Sulene group. CONCLUSION: The significant reduction in femoral head penetration obtained with the Durasul compared with Sulene in uncemented THA resulted in lower osteolysis and revision rates after 20 years.Cite this article: Bone Joint J 2022;104-B(9):1032-1038.

Outcome measures and survivorship following total hip arthroplasty in adolescent population.

BACKGROUND: The most frequent indication for total hip arthroplasty (THA) in adolescent patients has been juvenile idiopathic arthritis (JIA). However, in recent years, other causes have become more prevalent. QUESTIONS/PURPOSES: (1) What is the survivorship following THA across the diagnostic spectrum in adolescent population? (2) How are quality of life results affected by systemic medical conditions? METHODS: We retrospectively reviewed all consecutive THA in patients under 21 years of age, performed at our Institution between 1993 and 2018. There were 34 prostheses implanted in 26 patients with a mean age of 18.4 years (range 11 to 21). The most frequent diagnosis was JIA (14 hips), followed by avascular necrosis (10 hips). Patient reported outcomes were assessed using Harris and Oxford Hip Scores (HHS and OHS), Visual Analogue Scale (VAS) and EuroQol-5D. Survivorship for revision and aseptic loosening was determined with Kaplan Meier analysis. RESULTS: At final follow-up, the overall survival rate was of 89.3% at 12-year follow-up. Three acetabular components underwent revision surgery for aseptic loosening. Clinical HHS significantly improved from 37.5 to 90.6 points (p < 0.001). Mean OHH was 37.4 points, with a final VAS of 1.64 points. Mean 5Q-5D was 0.704 with an interquartile range of 0.4 to 1.0. JIA patients displayed worse pre-operative HHS scores, and at final follow-up had worse HHS, OHS, VAS and EQ-5D scores compared to the rest of the patients. Complications included three intra-operative femoral fractures, one sciatic nerve palsy and one adductor contracture. CONCLUSION: THA in adolescent patients provides improved functional outcomes with acceptable revision rates at mid-term follow-up.

Do trabecular metal cups achieve better results when compared to hemispherical porous titanium cups in acetabular revision surgery?

BACKGROUND: Trabecular metal (TM) cups were introduced in order to achieve better ingrowth and stability of the cup in acetabular revision surgery. As their use has evolved over time, we have queried whether TM cups would improve results in terms of the rate of aseptic loosening when compared to historical uncemented porous titanium cups used in revision surgery for acetabular bone loss in Hospital La Paz (Madrid, Spain). METHODS: We retrospectively reviewed 197 acetabular revisions performed between 1991 and 2015. Titanium cups were used in 81 cases and TM cups in 116. The mean follow-up was 8.1 years (range 1-15); 12.0 ± 7.8 for titanium group and 5.4 ± 3.1 for TM group. The most common reason for revision was aseptic loosening. A Kaplan-Meier analysis was used to determine the survival of the cup, with radiological failure and re-revision due to aseptic loosening as the endpoints. Cox multivariate regression analyses were performed to assess different risk factors for failure. RESULTS: 1 TM cup and 1 titanium cup were re-revised due to aseptic loosening (p = 0.61). Radiological cup loosening was observed in 4 TM cups and 2 titanium cups (p = 1.0). At 6 years, the probability of not having radiological cup loosening was 97.4% (95% CI, 93.9-100) for the titanium cups and 95.1% for the TM cups (95% CI, 90.1-99.9) (p = 0.59). Another 5 cups were re-revised due to dislocation. Hips with a greater Paprosky defect showed a higher risk of loosening (p < 0.05, hazard risk (HR) 3.04; 95% CI, 0.97-9.54). CONCLUSIONS: This study shows there was no significant difference in re-revision due to aseptic loosening or radiological loosening between titanium and TM cups in revision surgery for acetabular bone loss. Both types of cups demonstrate excellent results with a low failure rate and minimal complications.

Preoperative Correction of Anemia to Allow a 3000 ml Blood Loss Without Transfusion in a Jehovah's Witness Presenting for Explantation of an Infected Hip Joint Prosthesis: A Case Report.

A 70-year-old Jehovah's Witness was treated with iron carboxymaltose intravenously, recombinant human erythropoietin alpha subcutaneously, and vitamin B12 and folate orally for 9 weeks to raise hemoglobin (Hb) from 10.8 to 17.0 g/dL before explantation of an infected hip joint prosthesis. The target Hb was calculated from the following formula: Hbtarget = Hbfinal/(1 - ABL/EBV), where Hbtarget= Hb to achieve before surgery, Hbfinal = lowest Hb patient could tolerate taking into consideration his comorbidities (7 g/dL), ABL = volume of blood the surgeon estimated the patient would lose intra- and postoperatively (3000 mL), and EBV = estimated blood volume (75 mL/kg for an adult man). Spinal anesthesia was provided with a single shot hyperbaric bupivacaine and fentanyl. Acute hypervolemic hemodilution was achieved with lactated Ringer's solution and hydroxyethyl starch. To further minimize blood loss, controlled hypotension to a mean blood pressure of 55 mm Hg was achieved with a propofol infusion and tranexamic acid was administered. Surgical blood loss was estimated to be 2500 mL. Hb at the end of surgery was 13.3 g/dL; on postoperative day 5, 11.7 g/L. No blood products were utilized.

Limiting spread of COVID-19 in an orthopaedic department-a perspective from Spain.

Besides national and international recommendations, orthopaedic departments face significant changes in daily activity and serious issues to maintain their standards in musculoskeletal care during the pandemic Covid-19 crisis that we are facing. This report retrospectively addresses measures that were progressively put in place to modify in a week time the activity of a busy orthopaedic department in a large tertiary university hospital in face of the pandemic. Surgical priorities and surgical outcomes are key aspects to consider. The experience may offer some insight to areas where the spread of the disease may be slower or delayed. Abrupt stop of scheduled surgery and clinics is useful to adapt an orthopaedic department to the overall hospital resource reorganization. Orthopaedic surgeons need to be aware of the risks to patients and personnel in view of underdiagnosed cases, which make pre-operative Covid-19 evaluation mandatory for all surgical cases.

Total Hip Arthroplasty with Use of the Cementless Zweymüller Alloclassic System: A Concise Follow-up, at a Minimum of 25 Years, of a Previous Report.

We previously reported the 10 to 13-year follow-up results for 104 total hip replacements with the Zweymüller Alloclassic stem and a threaded cup in 94 patients. The present study is a clinical and radiographic outcome update after a minimum follow-up of 25 years. Four patients (4 hips) were lost and 46 patients (50 hips) died, leaving 44 patients (50 hips) available for follow-up. Since our previous report, 7 cups and 2 stems were revised. At 20 years, the probability of survival of any component was 84.1% (95% confidence interval [CI], 73.91% to 94.29%) and the cumulative probability of not having stem loosening was 95.9% (95% CI, 95.51% to 96.29%). We observed proximal femoral osteolysis in 15 hips (30%), cortical hypertrophy in 21 hips (42%), and proximal femoral osteopenia in 30 hips (60%). The Zweymüller Alloclassic stem continues to provide excellent results after extended follow-up. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Mid-term comparative outcomes of autologous bone-marrow concentration to treat osteonecrosis of the femoral head in standard practice.

PURPOSE: To evaluate mid-term effectiveness of core decompression (CD) followed by injection of bone-marrow concentration (BMC) in osteonecrosis of the femoral head (ONFH) compared with CD alone. METHODS: We retrospectively studied 60 hips in 45 patients with ONFH Ficat I-II after a mean follow-up of 45 (range 24-171) months. Group A (19 hips) were treated with CD, and Group B (41 hips) with CD plus autologous BMC. Necrotic lesions were classified according to MRI findings in: (i) the lesion angle; and (ii) the relation of the necrotic area to the weight-bearing portion. Outcomes included clinical changes and radiographic femoral head collapse. Risk factors associated with radiological collapse were evaluated by Cox regression analysis. RESULTS: Postoperative Merlé D´Aubigne and Postel hip score was similar in both groups. Femoral head collapse was observed in 10/19 hips in Group A and 22/41 in Group B. At 24 months, the probability of not having a collapse was 56.4% (95% CI, 33.6%-79.1%) for Group A and 57.6% (95% CI, 41.7%-73.4%) for Group B (p = 0.47). The risk of collapse increased in hips with a lesion angle higher than 150° (p<0.02, hazard risk [HR] 4.073) in both groups. CONCLUSIONS: With the standard BMC technique performed without monitoring the number of progenitors in the concentrate, we are uncertain to observe a significant decrease in femoral head collapse compared to CD alone. Improved outcomes may require the monitoring of progenitor cells injected into the femoral head, particularly in large lesions.

The evolution of the technique of impaction bone grafting in femoral revision surgery has improved clinical outcome. A prospective mid-term study.

Ninety-three patients (97 hips) underwent impaction bone grafting (IBG) using a cemented tapered femoral stem at our institution. Forty-one hips were operated between 1993 and 1998 (group 1) and 56 hips between 1999 and 2007 (group 2). The use of an extended trochanteric osteotomy and a long stem was more frequent in group 2. Group 2 hips showed a better clinical result. One hip was revised for aseptic loosening and most failures were early periprosthetic fractures. The survival rate for reoperation for any cause was 82.9% for group 1 and 84.3% for group 2. Patients in group 1 had a higher risk for periprosthetic fractures and radiological subsidence >5mm. Experience and the evolution of the IBG technique have improved the good long-term outcome.

Increase of cortical bone after a cementless long stem in periprosthetic fractures.

BACKGROUND: Healing and functional recovery have been reported using an extensively porous-coated stem in Vancouver B2 and B3 periprosthetic fractures; however, loss of cortical bone has been observed when using these stems in revision surgery for aseptic loosening. However, it is unclear whether this bone loss influences subsequent loosening. QUESTION/PURPOSES: We analyze the healing fracture rate and whether the radiographic changes observed around and extensively porous-coated stem used for periprosthetic fractures affect function or loosening. METHODS: We retrospectively reviewed 35 patients with periprosthetic fractures (20 Vancouver B2 and 15 Vancouver B3). Patients' mean age at surgery was 80 years (range, 51-86 years). No cortical struts were used in this series. We evaluated radiographs for signs of loosening or subsidence. The cortical index and the femoral cortical width were measured at different levels on the immediate pre- and postoperative radiographs and at different periods of followup. The minimum followup was 3 years (mean, 8.3 years; range, 3-17 years). RESULTS: All fractures had healed, and all stems were clinically and radiographically stable at the end of followup. Nineteen hips showed nonprogressive radiographic subsidence during the first 3 postoperative months without clinical consequences. The cortical index and the lateral and medial cortical thickness increased over time. Increase of femoral cortex thicknesses was greater in cases with moderate preoperative osteoporosis and in cases with stems less than 16 mm in thickness. CONCLUSIONS: Our data suggest an extensively porous-coated stem for Vancouver B2 and B3 periprosthetic fractures leads to a high rate of union and stable fixation. Cortical index and lateral cortex thickness increased in these patients with periprosthetic fractures. Patients with moderate osteoporosis and those using thin stems showed a major increase in femoral cortex thickness over time.

Cup press fit in uncemented THA depends on sex, acetabular shape, and surgical technique.

BACKGROUND: Uncemented press-fit cups provide bone fixation in primary THA, but the use of screws is sometimes necessary to achieve primary stability of the socket. However, it is unclear whether and when screws should be used. QUESTION/PURPOSES: We analyzed the factors related to screw use with a press-fit uncemented cup and assessed whether screw use is associated with the same rates of loosening and revision as a press-fit technique. METHODS: We retrospectively reviewed 248 patients who underwent THA using the same prosthetic design. Eighty-eight hips had screws to achieve primary cup fixation (Group 1), and 189 did not (Group 2). Mean age was 50 years (range, 14-73 years). We analyzed factors related to the patient, acetabular type, and reconstruction of the rotation center of the hip. Minimum followup was 5 years (mean, 8.9 years; range, 5-12 years). RESULTS: We found higher screw use in women, patients with less physical activity, Acetabular Types A or C, and a distance from the center of the prosthetic femoral head to the normal center of rotation of more than 3 mm. There were four revisions in Group 1 and five in Group 2. Eight hips had radiographic loosening in Group 1 and nine in Group 2. Cups with a postoperative abduction angle of more than 50° had a higher risk for loosening. CONCLUSIONS: Press fit was achieved less frequently in women and patients with Acetabular Types A or C and less physical activity; a closer distance to the normal center of rotation decreased screw use. Screw use to augment fixation achieved survival similar to that of a press-fit cup. LEVEL OF EVIDENCE: Level II, prognostic study. See Instructions for Authors for a complete description of levels of evidence.

Alumina-on-alumina THA in patients with juvenile idiopathic arthritis: a 5-year followup study.

BACKGROUND: THA is a concern in juvenile idiopathic arthritis (JIA) owing to patients' youth, poor bone stock, and small physical size. QUESTIONS/PURPOSES: We asked whether (1) uncemented alumina-on-alumina THAs have good clinical and radiographic results at midterm followup in young patients with inflammatory arthritis and end-stage hip disease secondary to JIA, and (2) the anatomic center of rotation of the hip could be reconstructed in patients with acetabular protrusion. We also assessed the rate of surgical complications. PATIENTS AND METHODS: We retrospectively reviewed 31 alumina-on-alumina THAs in 21 patients with a mean age of 30.9 years (range, 14-48 years). Minimum followup until the time of revision of any component or the latest evaluation was 16 months. For nonrevised cases, the minimum followup was 60 months (range, 60-108 months). Acetabular protrusion was mild in 17 hips (Group 1) and moderate-severe in 14 (Group 2). Bone autograft was used to reconstruct the acetabulum in Group 2. Acetabular reconstruction was evaluated according to Ranawat et al. RESULTS: One cup was revised owing to aseptic loosening at 16 months; the remaining hips showed good clinical and radiographic results. The mean postoperative horizontal distance and the distance between the center of the head of the prosthesis and the true center of the femoral head improved in Group 2. There were no complications related to alumina. CONCLUSIONS: Although THA is a technically demanding procedure in patients with JIA, uncemented alumina-on-alumina THA provides pain relief and improves quality of life. In patients with acetabular protrusion, bone grafts enable anatomic cup positioning. Continued followup will be required to determine whether the alumina-on-alumina bearings in patients with JIA result in less osteolysis and loosening. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Alumina-on-alumina hip replacement in developmental dysplasia of the hip.

Total hip arthroplasty (THA) in patients with developmental dysplasia of the hip (DDH) requires complex reconstructive techniques and presents an increased risk of complications. Because of these patients' young age, alternative bearing surfaces such as alumina-on-alumina couples could be an option. We asked whether moderate or severe congenital dysplasia of the hip would influence the clinical outcome and rates of cup loosening in our patients. We prospectively compared 50 hips in patients with dysplastic hip (group 1) and 22 hips in patients with a low or high dislocation (group 2) using an alumina-on-alumina THA. The minimum follow-up was 5 years (range 5-10 years). Age, activity level, and implant size were greater in group 1. Preoperative function and range of mobility were worse in group 2. The survival rate for cup loosening at 5 years was 89.8% (95% confidence interval, 78.7%-100%) for group 1 and 81.7% (95% confidence interval, 57.6%-100%) for group 2. An alumina-on-alumina THA provides a high level of pain relief and functional improvement in hip dysplasia. Continued follow-up will be required to determine if the alumina-on-alumina bearings in these patients result in less osteolysis and loosening.

The survival and fate of acetabular reconstruction with impaction grafting for large defects.

BACKGROUND: Impaction bone grafting has been used for acetabular reconstruction in revision surgery. However, most series do not establish differences in survival in revisions with differing severity of bone loss. QUESTIONS/PURPOSES: We therefore determined (1) the survival rate for rerevision associated with varying degrees of bone loss; (2) the frequency with which bone graft resorption occurred; and (3) whether the reconstruction restored the anatomic center of rotation of the hip. METHODS: We retrospectively reviewed 165 patients (181 hips) who underwent rerevision for major bone loss. Using the classification of Paprosky et al. 98 hips had a Grade 3A defect and 83 a Grade 3B. We determined survival rates for revision and graft resorption. Cup position was determined measuring vertical and horizontal positions and the distance from the center of the prosthetic femoral head to the normal center of rotation of the hip in both groups according to Ranawat. The minimum followup until rerevision or the latest evaluation was 0.3 years months (mean, 7.5 years; range, 0.3-17.7 years). RESULTS: The survival rate for revision at 8 years was 84% (95% confidence interval: 61-100) for Grade 3A and 82% (95% confidence interval: 68-100) for Grade 3B. Twelve hips were rerevised. Seventeen grafts showed bone resorption. Acetabular cup position was anatomically restored in both Grades 3A and 3B. CONCLUSIONS: The midterm results for impacted bone allograft and cemented all-polyethylene cups were similar in both Grade 3A and Grade 3B hips. Acetabular reconstruction allows anatomic positioning of the cups and is associated with a low rate of rerevision.

Alumina-on-alumina total hip arthroplasty in young patients: diagnosis is more important than age.

Total hip arthroplasty (THA) in young patients has a high loosening rate, due in part to acetabular deformities that may compromise bone fixation and polyethylene wear. We therefore asked whether wear or osteolysis and loosening differ in patients under 40 years of age with alumina-on-alumina THA compared to those who are older. We prospectively followed 56 patients (63 hips) younger than 40 years (Group 1) and 247 patients (274 hips) older than 40 (Group 2) who had an alumina-on-alumina THA. The minimum followup was 4 years (mean, 5.6 years; range, 4-9 years). The two groups differed in various features: there were no patients with primary osteoarthritis in Group 1 and they had worse preoperative function and range of mobility, while weight, activity level, and implant size were greater in Group 2. The survival rate for cup loosening at 80 months postsurgery was 90.8% (95% confidence interval, 82.9-98.6%) for Group 1 and 96.5% (95% confidence interval, 94.2-98.7%) for Group 2. Cup loosening was less frequent with primary osteoarthritis than with severe developmental dysplasia of the hip. Although an alumina-on-alumina THA provided similar midterm survival and radiographic loosening in both age groups, the preoperative diagnosis seems more important than age for outcome. Continued followup will be required to determine if the alumina-on-alumina bearings in young patients result less risk of osteolysis and loosening.

Total hip arthroplasty with use of the cementless Zweymüller Alloclassic system. A ten to thirteen-year follow-up study.

BACKGROUND: The Zweymüller Alloclassic total hip arthroplasty system is widely used, although few intermediate-term studies have been published. The purpose of the present study was to evaluate the clinical and radiographic results of this system after ten years. METHODS: One hundred and twenty-four consecutive primary total hip arthroplasties were performed with the Zweymüller Alloclassic cementless system at our institution between February 1988 and March 1991, and 104 hips (ninety-four patients) were retrospectively reviewed after a minimum duration of follow-up of ten years. The mean age of the patients at the time of the arthroplasty was 62.3 years (range, twenty-five to seventy-seven years). The mean duration of follow-up was 11.3 years. Standard radiographs were made for all patients immediately after the operation, at six and twelve months, and annually thereafter for at least ten years. Cox multivariate regression analysis was performed to assess the influence of various factors on survival of the implant. RESULTS: The cumulative probability of not having a revision of any prosthetic component for any reason was 94.1% (95% confidence interval, 91.9% to 96.3%) at twelve years in the best-case scenario and 85.3% (95% confidence interval, 82.1% to 88.5%) at twelve years in the worst-case scenario for the entire series of 124 hips. Among the 104 hips in the follow-up study, three acetabular components and no stems were revised. Two hips had level-4 pain according to the system of Merle D'Aubigné and Postel. Seven acetabular components (7%) were loose at twelve years, and all stems had radiographic evidence of stable fixation. Acetabular cup loosening was related to a vertical cup angle (p = 0.0008, Student t test), acetabular wear of > or =1 mm (p = 0.001, Fisher exact test), and a 32-mm femoral head (p = 0.001, Fisher exact test). Although femoral osteolysis was seen in eighteen hips (17%) at twelve years, all osteolytic cavities were proximal and focal. CONCLUSIONS: The Zweymüller Alloclassic prosthesis, particularly its femoral stem, demonstrated good results and durable fixation at a minimum of ten years of follow-up.