Citations

Background: Dual-mobility (DM) implants reduce the risk of dislocation in patients who have undergone total hip arthroplasty (THA); however, DM implants are at risk for large-head dislocation and intraprosthetic dissociation (IPD), where the inner femoral head dissociates from the outer polyethylene head. This study aimed to report the incidence of DM dislocation and IPD, evaluate the rate of recognition of IPD before and after reduction, investigate the outcomes of these complications, and provide treatment recommendations for their management. Methods: Between 2010 and 2021, 695 primary and 758 revision THAs were performed with DM constructs at a single institution. There were 44 large-head dislocations (3.0%) and 10 IPDs (0.7%). Four additional IPDs occurred during attempted closed reduction, increasing the IPD incidence to 0.96%. We reviewed prior instability history, dislocation management, success of reduction, recognition of IPD, and subsequent rates of revision and complications. The mean follow-up was 2.5 years. Results: Nine of 10 IPDs were missed at presentation and thus not treated as such. Sixty-three percent of attempted closed reductions in the emergency department failed and led to 4 IPDs and 1 periprosthetic fracture. Reduction success was associated with the following factors: use of general anesthesia with paralysis (p = 0.02), having the reduction performed by an orthopaedist (p = 0.03), and undergoing only 1 reduction attempt (p = 0.015). Two-thirds of dislocations required revision. The rate of redislocation was 33%, and 5 hips required subsequent revision at a mean of 1.8 years after the initial dislocation. Conclusions: We present an evaluation of DM-implant dislocation and dissociation along with management recommendations based on these data. Given the low success and high complication rates of attempted closed reduction and the need for eventual revision, we recommend that all patients with dislocated DM implants be brought to the operating room for closed reduction as well as potential revision if the reduction fails. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

AimsContemporary outcomes of primary total hip arthroplasties (THAs) with highly cross-linked polyethylene (HXLPE) liners in patients with inflammatory arthritis have not been well studied. This study examined the implant survivorship, complications, radiological results, and clinical outcomes of THA in patients with inflammatory arthritis.MethodsWe identified 418 hips (350 patients) with a primary diagnosis of inflammatory arthritis who underwent primary THA with HXLPE liners from January 2000 to December 2017. Of these hips, 68% had rheumatoid arthritis (n = 286), 13% ankylosing spondylitis (n = 53), 7% juvenile rheumatoid arthritis (n = 29), 6% psoriatic arthritis (n = 24), 5% systemic lupus erythematosus (n = 23), and 1% scleroderma (n = 3). Mean age was 58 years (SD 14.8), 66.3% were female (n = 277), and mean BMI was 29 kg/m2 (SD 7). Uncemented femoral components were used in 77% of cases (n = 320). Uncemented acetabular components were used in all patients. Competing risk analysis was used accounting for death. Mean follow-up was 4.5 years (2 to 18).ResultsThe ten-year cumulative incidence of any revision was 3%, and was highest in psoriatic arthritis patients (16%). The most common indications for the 15 revisions were dislocations (n = 8) and periprosthetic joint infections (PJI; n = 4, all on disease-modifying antirheumatic drugs (DMARDs)). The ten-year cumulative incidence of reoperation was 6.1%, with the most common indications being wound infections (six cases, four on DMARDs) and postoperative periprosthetic femur fractures (two cases, both uncemented femoral components). The ten-year cumulative incidence of complications not requiring reoperation was 13.1%, with the most common being intraoperative periprosthetic femur fracture (15 cases, 14 uncemented femoral components; p = 0.13). Radiological evidence of early femoral component subsidence was observed in six cases (all uncemented). Only one femoral component ultimately developed aseptic loosening. Harris Hip Scores substantially improved (p < 0.001).ConclusionContemporary primary THAs with HXLPE in patients with inflammatory arthritis had excellent survivorship and good functional outcomes regardless of fixation method. Dislocation, PJI, and periprosthetic fracture were the most common complications in this cohort with inflammatory arthritis.Cite this article: Bone Joint J 2023;105-B(7):768–774.

Background: Many risk factors have been described for dislocation following total hip arthroplasty (THA), yet a patient-specific risk assessment tool remains elusive. The purpose of this study was to develop a high-dimensional, patient-specific risk-stratification nomogram that allows dynamic risk modification based on operative decisions. Methods: In this study, 29,349 THAs, including 21,978 primary and 7371 revision cases, performed between 1998 and 2018 were evaluated. During a mean 6-year follow-up, 1521 THAs were followed by a dislocation. Patients were characterized, through individual-chart review, according to non-modifiable factors (demographics, indication for THA, spine disease, prior spine surgery, and neurologic disease) and modifiable operative decisions (operative approach, femoral head diameter, and type of acetabular liner [standard, elevated, constrained, or dual-mobility]). Multivariable regression models and nomograms were developed with dislocation as a binary outcome at 1 year and 5 years postoperatively. Results: Dislocation risk, based on patient-specific comorbidities and operative decisions, was wide-ranging—from 0.3% to 13% at 1 year and from 0.4% to 19% at 5 years after primary THA, and from 2% to 32% at 1 year and from 3% to 42% at 5 years after revision THA. In the primary-THA group, the direct anterior approach (hazard ratio [HR] = 0.27) and lateral approach (HR = 0.58) decreased the dislocation risk compared with the posterior approach. After adjusting for the approach in that group, the combination of a ≥36-mm-diameter femoral head and an elevated liner yielded the largest decrease in dislocation risk (HR = 0.28), followed by dual-mobility constructs (HR = 0.48). In the patients who underwent revision THA, the adjusted risk of dislocation was most markedly decreased by the use of a dual-mobility construct (HR = 0.40), followed by a ≥36-mm femoral head and an elevated liner (HR = 0.88). The adjusted risk of dislocation after revision THA was decreased by acetabular revision (HR = 0.58), irrespective of whether other components were revised. Conclusions: Our patient-specific dislocation risk calculator, which was strengthened by our use of a robust multivariable model that accounted for comorbidities associated with instability, demonstrated wide-ranging patient-specific risks based on comorbidity profiles. The resultant nomograms can be used as a screening tool to identify patients at high risk for dislocation following THA and to individualize operative decisions for evidence-based risk mitigation. Level of Evidence: Prognostic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Aims The aim of this study was to evaluate the incidence of liner malseating in two commonly used dual-mobility (DM) designs. Secondary aims included determining the risk of dislocation, survival, and clinical outcomes. Methods We retrospectively identified 256 primary total hip arthroplasties (THAs) that included a DM component (144 Stryker MDM and 112 Zimmer-Biomet G7) in 233 patients, performed between January 2012 and December 2019. Postoperative radiographs were reviewed independently for malseating of the liner by five reviewers. The mean age of the patients at the time of THA was 66 years (18 to 93), 166 (65%) were female, and the mean BMI was 30 kg/m2 (17 to 57). The mean follow-up was 3.5 years (2.0 to 9.2). Results Three liners (1.2%) were malseated, including two MDMs (1.4%) and one G7 (0.9%). No clinical consequence was identified from malseating. The five-year survival free of dislocation was 97.1%, including two DM and one intraprosthetic dislocation. The five-year survival free of revision was 95.4%, with seven revisions. The mean Harris Hip Scores increased from 46 (24 to 69) preoperatively to 81 (40 to 100) at two years postoperatively (p < 0.001). Conclusion The incidence of DM liner malseating after primary THA was low, with no known clinical consequences at mid-term follow-up. Malseating is not exclusive of design, and these findings emphasize the importance of careful evaluation of the liner after impaction to avoid this complication. Cite this article: Bone Joint J 2022;104-B(5):598–603.

ABSTRACT Hip dysplasia is a common cause of hip pain and a known risk factor for hip osteoarthritis (OA) and early total hip arthroplasty (THA). Unfortunately, little is known about the specific factors associated with an increased risk of OA. The purpose was (i) to report the overall rate of symptomatic hip OA and THA and (ii) to identify radiographic features and patient characteristics associated with the development of symptomatic hip OA. A geographic database was used to identify all patients aged 14–50 years old diagnosed with symptomatic hip dysplasia between 2000 and 2016. Kaplan–Meier analysis was used to determine the rate of symptomatic hip OA, defined as a Tönnis grade of ≥1 on hip radiograph. Univariate and multivariate proportional hazard regression models were performed to determine risk factors for OA. One hundred and fifty-nine hips (144 patients) with hip dysplasia (52 F:107 M) out of 1893 patients with hip pain were included. Of these, 45 (28%) had severe hip dysplasia with a lateral center-edge angle ≤18°. Mean age at time of presentation was 26.1 (±10.1) years. Mean follow-up time was 8.2 (±5) years. The rate of OA was 20%. THA was performed in 11% of patients. Body mass index &gt;29 (P = 0.03) and increased age (P &lt; 0.01) were risk factors for OA. Patients with symptomatic hip dysplasia are at significant risk of developing hip OA. Body mass index &gt;29 and age ≥35 years at the time of presentation with hip pain were risk factors for hip OA.

Aims Bone marrow-derived mesenchymal stem cells obtained from bone marrow aspirate concentrate (BMAC) with platelet-rich plasma (PRP), has been used as an adjuvant to hip decompression. Early results have shown promise for hip preservation in patients with osteonecrosis (ON) of the femoral head. The purpose of the current study is to examine the mid-term outcome of this treatment in patients with precollapse corticosteroid-induced ON of the femoral head. Methods In all, 22 patients (35 hips; 11 males and 11 females) with precollapse corticosteroid-induced ON of the femoral head underwent hip decompression combined with BMAC and PRP. Mean age and BMI were 43 years (SD 12) and 31 kg/m² (SD 6), respectively, at the time of surgery. Survivorship free from femoral head collapse and total hip arthroplasty (THA) and risk factors for progression were evaluated at minimum five-years of clinical follow-up with a mean follow-up of seven years (5 to 8). Results Survivorship free from femoral head collapse and THA for any reason was 84% and 67% at seven years postoperatively, respectively. Risk factors for conversion to THA included a high preoperative modified Kerboul angle (grade 3 or 4) based on preoperative MRI (hazard ratio (HR) 3.96; p = 0.047) and corticosteroid use at the time of decompression (HR 4.15; p = 0.039). The seven-year survivorship for patients with grade 1 or 2 Kerboul angles for conversion to THA for articular collapse, and THA for any reason, were 96% and 72%, respectively, versus THA for articular collapse and THA for any reason in patients with grade 3 or 4 Kerboul angles of 40% (p = 0.003) and 40% (p = 0.032). Conclusion At seven years, hip decompression augmented with BMAC and PRP provided a 67% survivorship free from THA in patients with corticosteroid-induced ON. Ideal candidates for this procedure are patients with low preoperative Kerboul angles and can stop corticosteroid treatment prior to decompression. Cite this article: Bone Jt Open 2021;2(11):926–931.

ABSTRACTIt is unclear whether treatment of intraarticular pathology should be performed during periacetabular osteotomy (PAO) to improve outcomes. Therefore, we asked: (i) What are the clinical results of PAO in patients with and without intraarticular intervention? (ii) Is there a difference in reoperations with and without intraarticular intervention? and (iii) Is there a difference in clinical results and reoperations depending on preoperative Tönnis Grade if intraarticular intervention is performed? Prospective evaluation of 161 PAO in 146 patients was performed. The cohort was 84.5% female, mean age was 26.7 ± 7.9 years and mean follow-up was 2.4 years; 112 hips had Grade 0 changes and 49 hips had Grade 1 changes. Patients were classified into three groups based on treatments during PAO: major (labral repair, femoral head–neck osteochondroplasty), minor (labral debridement, femoral/acetabular chondroplasty) or no intervention. A subset of eight patient-reported outcome measures (PROMs) was analyzed to determine whether the minimal clinically important difference (MCID) was achieved. Major, minor and no intervention groups exceeded the MCID in 5, 8 and 8, of 8 PROMs (P ≥ 0.20), respectively; intraarticular interventions did not influence reoperation-free survival (P ≥ 0.35). By Tönnis Grade, PROMs exceeding MCID decreased in Grade 1 versus 0 receiving no intervention (P &lt; 0.001) but did not decrease for either intervention (P ≥ 0.14); intraarticular interventions did not influence reoperation-free survival (P ≥ 0.38). Overall, intraarticular intervention was associated with excellent PROMs and reoperation-free survival. Although Grade 1 patients had fewer PROM which achieved MCID, intraarticular interventions attenuated this decrease, suggesting a therapeutic advantage of intraarticular procedures for more advanced pathology.

Background: Instability remains a challenging problem following total hip arthroplasty (THA). Dual-mobility (DM) components are used with increasing frequency to mitigate this potential complication. As has been shown with larger metal-on-metal (MoM) THA, the larger size femoral head may pose an increased risk of groin pain. This study aims to evaluate the prevalence of groin pain following primary DM THA compared to other THA constructs. Methods: We identified 190 primary THAs (183 patients) performed with DM components at a single academic institution from 2008 to 2017. We retrospectively reviewed standardised patient questionnaires and the electronic medical record to determine the prevalence of groin pain. DM patients were compared to historical controls of 39 MoM hip resurfacing, 26 large-head MoM THA, and 217 conventional THA. Mean age was 64 years, 58% were female, mean body mass index was 30 kg/m 2 , and mean follow-up was 3.5 years (range 2–8 years). Results: The prevalence of groin pain in patients with DM components was 5%, similar to the prevalence reported by patients with conventional THA (7%). There was a decreased prevalence of groin pain in DM patients compared to hip resurfacing (18%) and MoM THA (15%). Among the 9 DM patients with groin pain, 1 was treated with iliopsoas injection, and 1 underwent radiofrequency ablation of the articular nerve. Conclusions: This study documents a relatively low prevalence of groin pain among primary DM THA patients. This is comparable with historical controls of conventional THA and decreased compared to hip resurfacing and large head MoM THA.

AbstractPeriacetabular osteotomy (PAO) is effective in the management of developmental dysplasia of the hip and femoroacetabular impingement secondary to acetabular retroversion. During anteverting PAO for acetabular retroversion, the need for both labral treatment and femoral head–neck junction osteochondroplasty remains equivocal. Accordingly, this study evaluated patient-reported outcome measures (PROM) and reoperation rates after anteverting PAO with or without intraarticular intervention. Cases of anteverting PAO performed at a single institution between November 2009 and January 2016 were retrospectively reviewed. Patients were divided into three groups: no intervention and intraarticular intervention with arthrotomy or arthroscopy. Subsequently, patients were reclassified by the intraarticular procedure performed at surgery into major (labral repair, femoral head–neck osteochondroplasty) and minor (labral debridement, femoral/acetabular chondroplasty) groups. The cohort was 75% female, median age was 19.5 years and mean body mass index was 25.0 kg/m2. Preoperative to postoperative improvement was compared to minimal clinically important differences (MCID) for eight PROM. Patients receiving major interventions exceeded MCID in a greater proportion of PROM compared to minor and no intervention groups (P &lt; 0.007); major or minor interventions did not increase the risk of reoperation over no intervention (P ≥ 0.39). Based on the current data, surgeons performing anteverting PAO for acetabular retroversion should perform arthroscopic or open labral repair and assess for impingement after the correction and perform a head–neck junction osteochondroplasty if indicated.

Introduction: There are many treatment options for patients who have osteonecrosis of the femoral head (ONFH) and management strategies vary widely both among and within individual countries. Although many researchers have attempted to elucidate the optimal strategies for managing this disease, the lack of large-scale randomized control trials and the lack of agreement on disease staging have curtailed the development of clear-cut guidelines. Materials and Methods: The Association Research Circulation Osseous (ARCO) group sought to address three questions for the management of patients who have ONFH: 1) What imaging studies are most sensitive and specific for the diagnostic evaluation of patients who have ONFH?; 2) What is the best treatment strategy for preventing disease progression in patients who have pre-collapse lesions?; and 3) What is the best treatment strategy for patients who have post-collapse disease? The Patient, Intervention, Comparison, and Outcome (PICO) format was used to formulate the search strategy for each research question. A systematic review will be performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. ARCO participants have been allocated to three groups, each representing one of the PICO questions. After qualitative and quantitative analysis of the data extracted from studies pertaining to each of the three research questions, a set of evidence-based clinical practice guidelines will be proposed for the management of patients who have ONFH. Discussion: It is not always clear which treatment method is optimal for the management of ONFH. Thus, many surgeons have developed and performed various procedures based on patient-specific factors. As there is no consensus on the optimal treatment for various stages of disease, it was clear that developing evidence-based clinical practice guidelines would provide more structure and uniformity to management of these patients. Therefore, the results of this systematic review will lead to the development guidelines that may improve patient-care strategies and result in better outcomes for patients who have ONFH.