Constrained Liners Research Articles

Conventional single articulation constrained liners in revision hip arthroplasty: risk factors for failure and their combinations.

Constrained liners (CLs) have been used in revision total hip arthroplasty (rTHA) with varying results. Relatively few studies have identified specific risk factors for failure. This study aimed to assess implant survivorship and complication rates, identify risk factors for constraint-related complications, and assess the effect of multiple factors present in a single case. We conducted a retrospective analysis of 101 rTHAs for various aseptic indications and as second-stage procedures for periprosthetic joint infection (PJI) utilising 2 models of conventional single-articulation CLs. We excluded 8 cases in which the liners were removed early due to PJI and assessed the risk factors for constraint-related complications in the remaining 93 cases. The mean follow-up duration for complication-free cases was 6.5 years (range 4.7-10.5 years). The incidences of dislocation of a prosthetic head and loosening of the acetabular component were 19.8% and 5.0%, respectively. We also observed 8 cases where the locking ring of the liner was dislodged without dislocation (1 case required re-revision). The presence of factors related to impingement (cup retention, smaller internal diameter CLs, signs of probable impingement from the femoral side) was associated with higher rates of constraint-related complications. The presence of factors related to soft-tissue stabilisers did not increase the rate of complications. The simultaneous presence of multiple impingement-related risk factors resulted in worse outcomes. CLs may be less effective for treating or preventing instability related to impingement. CLs should be used with caution or avoided when multiple impingement-related risk factors are present.

Large variability in degree of constraint of reverse total shoulder arthroplasty liners between different implant systems.

The liner design is a key determinant of the constraint of a reverse total shoulder arthroplasty (rTSA). The aim of this study was to compare the degree of constraint of rTSA liners between different implant systems. An implant company's independent 3D shoulder arthroplasty planning software (mediCAD 3D shoulder v. 7.0, module v. 2.1.84.173.43) was used to determine the jump height of standard and constrained liners of different sizes (radius of curvature) of all available companies. The obtained parameters were used to calculate the stability ratio (degree of constraint) and angle of coverage (degree of glenosphere coverage by liner) of the different systems. Measurements were independently performed by two raters, and intraclass correlation coefficients were calculated to perform a reliability analysis. Additionally, measurements were compared with parameters provided by the companies themselves, when available, to ensure validity of the software-derived measurements. There were variations in jump height between rTSA systems at a given size, resulting in large differences in stability ratio between systems. Standard liners exhibited a stability ratio range from 126% to 214% (mean 158% (SD 23%)) and constrained liners a range from 151% to 479% (mean 245% (SD 76%)). The angle of coverage showed a range from 103° to 130° (mean 115° (SD 7°)) for standard and a range from 113° to 156° (mean 133° (SD 11°)) for constrained liners. Four arthroplasty systems kept the stability ratio of standard liners constant (within 5%) across different sizes, while one system showed slight inconsistencies (within 10%), and ten arthroplasty systems showed large inconsistencies (range 11% to 28%). The stability ratio of constrained liners was consistent across different sizes in two arthroplasty systems and inconsistent in seven systems (range 18% to 106%). Large differences in jump height and resulting degree of constraint of rTSA liners were observed between different implant systems, and in many cases even within the same implant systems. While the immediate clinical effect remains unclear, in theory the degree of constraint of the liner plays an important role for the dislocation and notching risk of a rTSA system.

Do Constrained Liners (in a 145° onlay implant) Provide Any Benefit? A Matched Retrospective Study

The purpose of this study was to compare the outcomes of primary reverse total shoulder arthroplasty (rTSA) using constrained liners (in a 145° onlay implant, Exactech, Equinoxe) with primary rTSA using standard liners with a minimum 1-year follow-up. A total of 836 primary rTSA patients were analyzed in this study. Patients treated with constrained liners (n=209) were cross-matched 1:3 for age, gender, glenosphere diameter, and follow-up duration, and compared with 627 patients who underwent primary rTSA with standard liners. Study endpoint was at one year. Outcomes were analyzed preoperatively and at the latest follow-up. Patient characteristics, postoperative range of motion (ROM), patient reported outcomes (PROs), complications and revisions were recorded. There was no statistically significant changes in improvement in pain (-4.9 vs -5.1; p=0.356), ROM (abduction, 45.7° vs 47.9°; p=0.522) (forward elevation, 44.0 vs 50.8°; p=0.057) (internal rotation score 1.0 vs 1.1; p=0.709) (external rotation, 17.9° vs 16.7°; p=0.543), or PROs (American Shoulder and Elbow Surgeons Score, 44.5 vs 43.7; p=0.107) (Shoulder Arthroplasty Smart score, 27.5 vs 30.0; p=0.052) between the constrained and standard liner cohorts at minimum 1 year follow-up. However, the constrained liner rTSA cohort had a significantly higher rate of adverse events (6.2% vs. 2.7%; p=0.012), including a higher rate of scapular notching (15.6% vs. 8.8%; p=0.015). The utilization of constrained liners in primary rTSA demonstrated no significant difference in the change in pain, abduction, forward elevation, ER and IR scores, ASES scores, and SAS scores at minimum 1-year follow-up. There was no significant difference in forward elevation or abduction compared to standard liners. However, we observed that the overall rate of adverse events, including scapular notching were significantly higher in the constrained liner cohort. Long-term clinical and radiographic follow-up is necessary to fully elucidate the durability of these results. At this time, it is unclear if constrained liners have any benefit in rTSA.

The push-through total femoral prosthesis for revision of a total hip or knee replacement with extreme bone loss.

The aim of the present study was to assess outcomes of using the push-through total femoral prothesis (PTTF) for revision total hip replacement with extreme bone loss. 10 consecutive patients who received PTTF between 2012 and 2018 for revision hip arthroplasty were included in the study. Primary functional outcomes were assessed using Harris Hip Score (HHS), Toronto Extremity Salvage Score (TESS) and Musculoskeletal Tumor Society (MSTS) scores. Range of motion, complications, and ambulatory status were also recorded to assess secondary outcomes. 2 of 10 patients underwent surgery with PTTF for both knee and hip arthroplasty revision. The mean time between index surgery and PTTF was 15 years (3-32 yrs). Acetabular components were revised in 6 of 10 patients during PTTF application. After a mean follow-up of 5.9 years, hip dislocations occurred in 3 patients. All of the dislocated hips were ones with retained conventional non-constrained acetabular bearings. Patient satisfaction was high (MSTS: 67%, HHS: 61.2%, TESS 64.6%) despite high re-operation rate (40%) and minor postoperative problems. PTTF should be considered for hip and knee arthroplasty revision procedures in patients with an extreme bone defect. Consistent usage of constrained liners should be considered to avoid hip dislocation, which was our main problem following the procedure.

LOW RISK OF CUP FIXATION FAILURE AT TEN YEARS USING CONSTRAINED LINER AT THE SAME TIME OF ACETABULAR COMPONENT REVISION

There remains concern with the use of constrained liners (CL) implanted at the time of acetabular cup revision in revision total hip replacement (rTHA). The aim of this study was to determine the implant survival in rTHA when a CL was implanted at the same time as acetabular cup revision.We reviewed our institutional database to identify all consecutive rTHAs where a CL was implanted simultaneously at the time acetabular cup revision from 2001 to 2021. One-hundred and seventy-four revisions (173 patients) were included in the study. Mean follow-up of 8.7 years (range two – 21.7). The most common indications for rTHA were instability (35%), second-stage periprosthetic joint infection (26.4%), and aseptic loosening (17.2%).Kaplan Meier Analysis was used to determine survival with all-cause re-revision and revision for cup aseptic loosening (fixation failure) as the endpoints.A total of 32 (18.3%) patients underwent re-revision at a mean time of 2.9 years (range 0.1 – 14.1). The most common reasons for re-revision were instability (14), periprosthetic joint infection (seven), and loosening of the femoral component (four). Three (1.7%) required re-revision due to aseptic loosening of the acetabular component (fixation failure) at a mean of two years (0.1 – 5.1). Acetabular component survival free from re-revision due to aseptic loosening was 98.9% (95% CI 97.3 – 100) at five-years and 98.1% (95% CI 95.8 – 100) at 10-years. There were no acetabular component fixation failures in modern highly porous shells.CLs implanted at the time acetabular cup revision in rTHA have a 98.1% 10-year survival free from acetabular cup aseptic loosening (fixation failure). There were no cup fixation failures in modern highly porous shells. Thus, when necessary, implanting a CL during revision of an acetabular component with stable screw fixation is safe with an extremely low risk of cup fixation failure.

Surgical Approach Does Not Influence Instability Risk in Revision Total Hip Arthroplasty

BackgroundAlthough the direct anterior (DA) approach has increased in popularity for primary total hip arthroplasty (THA), there is limited evidence regarding its use for revision THA. It is unknown whether the dislocation benefit seen in the primary setting translates to revision cases. MethodsThis retrospective review compared the dislocation rates of revision THA performed through DA versus postero-lateral (PL) approaches at a single institution (2011 to 2021). Exclusion criteria included revision for instability, ≥ 2 prior revisions, approaches other than DA or PL, and placement of dual-mobility or constrained liners. There were 182 hips in 173 patients that met the inclusion criteria. The average follow-up was 6.5 years (range, 2 to 8 years). ResultsThere was a trend toward more both-component revisions being performed through the PL approach. There were no differences in dislocation rates between the DA revision and PL revision cohorts, which were 8.1% (5 of 72) and 7.5% (9 of 120), respectively (P = .999). Dislocation trended lower when the revision approach was discordant from the primary approach compared to cases where primary and revision had a concordant approach (4.9 versus 8.5%), but this was not statistically significant (P = .740). No significant differences were found in return to operating room, 90-day emergency department visits, or 90-day readmissions. However, the length of stay was significantly shorter in patients who had DA revisions after a primary PL procedure (P = .021). ConclusionsDislocation rates following revision THA did not differ between the DA and PL approaches irrespective of the primary approach. Surgeons should choose their revision approach based on their experience and the specific needs of the patient.

Dual-mobility bearings reduce instability but may not be the only answer in revision total hip arthroplasty for recurrent dislocation.

There is little information in the literature about the use of dual-mobility (DM) bearings in preventing re-dislocation in revision total hip arthroplasty (THA). The aim of this study was to compare the use of DM bearings, standard bearings, and constrained liners in revision THA for recurrent dislocation, and to identify risk factors for re-dislocation. We reviewed 86 consecutive revision THAs performed for dislocation between August 2012 and July 2019. A total of 38 revisions (44.2%) involved a DM bearing, while 39 (45.3%) and nine (10.5%) involved a standard bearing and a constrained liner, respectively. Rates of re-dislocation, re-revision for dislocation, and overall re-revision were compared. Radiographs were assessed for the positioning of the acetabular component, the restoration of the centre of rotation, leg length, and offset. Risk factors for re-dislocation were determined by Cox regression analysis. The modified Harris Hip Scores (mHHSs) were recorded. The mean age of the patients at the time of revision was 70 years (43 to 88); 54 were female (62.8%). The mean follow-up was 5.0 years (2.0 to 8.75). DM bearings were used significantly more frequently in elderly patients (p = 0.003) and in hips with abductor deficiency (p < 0.001). The re-dislocation rate was 13.2% for DM bearings compared with 17.9% for standard bearings, and 22.2% for constrained liners (p = 0.432). Re-revision-free survival for DM bearings was 84% (95% confidence interval (CI) 0.77 to 0.91) compared with 74% (95% CI 0.67 to 0.81) for standard articulations, and 67% (95% CI 0.51 to 0.82) for constrained liners (p = 0.361). Younger age (hazard ratio (HR) 0.92 (95% CI 0.85 to 0.99); p = 0.031), lower comorbidity (HR 0.44 (95% CI 0.20 to 0.95); p = 0.037), smaller heads (HR 0.80 (95% CI 0.64 to 0.99); p = 0.046), and retention of the acetabular component (HR 8.26 (95% CI 1.37 to 49.96); p = 0.022) were significantly associated with re-dislocation. All DM bearings which re-dislocated were in patients with abductor muscle deficiency (HR 48.34 (95% CI 0.03 to 7,737.98); p = 0.303). The radiological analysis did not reveal a significant relationship between restoration of the geometry of the hip and re-dislocation. The mean mHHSs significantly improved from 43 points (0 to 88) to 67 points (20 to 91; p < 0.001) at the final follow-up, with no differences between the types of bearing. We found that the use of DM bearings reduced the rates of re-dislocation and re-revision in revision THA for recurrent dislocation, but did not guarantee stability. Abductor deficiency is an important predictor of persistent instability.

Excellent 2-Year Outcomes of a Midlevel Constrained Liner Used in Stemless Primary TKA

Introduction: Instability after total knee arthroplasty (TKA) remains a leading cause of revision TKA and can lead to patient dissatisfaction. While many companies have developed midlevel constrained (MLC) polyethylene inserts in primary TKAs, there is little data on their outcomes. Purpose: We sought to analyze short-term outcomes including survivorship, rates of manipulation under anesthesia (MUA), and improvements in patient-reported outcome measures (PROMs) preoperatively to postoperatively in one design of MLC TKA. Methods: We prospectively followed consecutive primary TKA patients who received constrained inserts (Journey II or Legion Genesis II, Smith and Nephew) from 5 surgeons, 2019 to 2020, at a single academic institution. We analyzed revision-free survivorship, MUA rates, and PROMs, preoperatively to postoperatively. Results: A total of 356 patients were included with a mean age of 64 years; 49% were male and the mean body mass index (BMI) was 31 kg/m2. Sixteen patients (4.5%) underwent MUA and 3 patients (0.8%) underwent revision. Two patients underwent polyethylene exchange and patellar resection for patellar loosening. One patient underwent liner exchange for instability. The 2-year revision-free survivorship was 98.5% (95% confidence interval [CI]: 96.6%–100%). Survivorship free from revision for tibial or femoral aseptic loosening was 100% at 2 years. The 2-year survivorship free from MUA was 92.3% (95% CI: 88.6%–96.1%). The mean Knee Osteoarthritis and Injury Outcomes Score Joint Replacement (KOOS JR) was 81 at 2 years follow-up, while the Lower Extremity Activity Score (LEAS) score was 10.5. Conclusion: At a mean of 3 years follow-up, 2 types of MLCs used in primary TKA were associated with a low rate of early revision, low rate of MUA, and reliable improvement in functional outcomes. These MLCs were not associated with early loosening or unique failure modes.

Cage Augmentation of the Retained Acetabular Shell with a Dual Mobility Cup using the Double Socket Technique

Introduction: Prevention of dislocation after total hip arthroplasty (THA) remains a topic of debate. There are various surgical options to manage hip instability such as large femoral heads, and constrained liners, although the best option to tackle this is still controversial. In revision scenarios with previous well-fixed acetabulum shells, the cementation of polyethylene liners or the cementation of dual mobility (DM) into a well-fixed acetabulum shell (Double Socket Technique) has been documented before. Here, we report a case of re-revision THA, where we have used the Double Socket Technique of retaining the previous well-fixed acetabular shell with the cementation of the DM cup along with an anti-protrusio cage inside the socket. To the best of our knowledge, this is the first such a case to be reported worldwide. Case Report: A 54-year-old male who underwent THA in 1990 and an acetabulum cup revision in 2003 presented to us with right hip pain. Radiographs showed Paprosky Type 3A femoral bone loss and polyethylene wear. Intraoperatively after removing the polyethylene liner, the acetabulum shell was found to be well fixed and therefore retained. To increase stability, an anti-protrusio cage was inserted over it and a DM cup was cemented onto it (double socket). The femoral stem was revised using Wagner stem and encerclage wires and a hook plate was used to stabilize the osteotomy site. Conclusion: This technique is a reliable option and helps shorten the surgical time and reduce the bone loss that can occur in extracting a well-fixed acetabulum shell. The use of a DM cup decreases the chances of instability compared to the cementation of polyethylene liners and decreases the high failure rate associated with the use of cementation of constrained liners. The addition of an anti-protrusio cage in addition to the Double Socket Technique increases the stability of the construct. Keywords: Anti-protrusio cage, Dual mobility, Double socket, Revision total hip arthroplasty, Well-fixed acetabulum

Impact of constrained humeral liner on impingement-free range of motion and impingement type in reverse shoulder arthroplasty using a computer simulation

Dislocation is a major complication of reverse total shoulder arthroplasty (RSA). Humeral liner may be changed to the constrained type when stability doesn't improve by increasing glenosphere size or lateralization with implants, and patients, particularly women with obesity, have risks of periprosthetic instability that may be secondary to hinge adduction on the thorax, but there are few reports on its impact on the range of motion (ROM). This study aimed to determine the influence of humeral liner constraint on impingement-free ROM and impingement type utilizing an RSA computer simulation model. A virtual simulation model was created using 3D measurement software for conducting a simulation study. This study included twenty-five patients with rotator cuff tears and rotator cuff tear arthropathy. Impingement-free ROM and impingement patterns were measured during flexion, extension, abduction, adduction, external rotation, and internal rotation. Four different simulations of 2×2 were performed in each of the 25 cases, a total of 100 simulations: Glenosphere (38mm normal type vs. lateralized type) and humeral liner constraint (normal type vs. constrained type). There were four combinations: normal glenosphere and normal humeral liner, normal glenosphere and constrained humeral liner, lateralized glenosphere and normal humeral liner, and lateralized glenosphere and constrained humeral liner. Significant differences were found in all impingement-free ROM in one-way ANOVA (abduction: p=0.01, adduction: p<0.01, flexion: p=0.01, extension: p=0.02, external rotation: p<0.01, and internal rotation: p<0.01). Tukey's post-hoc tests showed that the impingement-free ROM was reduced during abduction, external rotation, and internal rotation with the combination of normal glenosphere and constrained humeral liner compared to the other combinations, and improved by glenoid lateralization compared to the combination of the lateralized glenosphere and constrained humeral liner. In the impingement pattern, Pearson's chi-squared test showed significantly greater proportion of impingement of the humeral liner into the superior part of the glenoid neck in abduction occurring in the combination of normal glenosphere and constrained humeral liner group compared to the other groups (p<0.01). Bonferroni post-hoc tests revealed that the combination of normal glenosphere and constrained humeral liner was significantly different from that of lateralized glenosphere and constrained humeral liner (p<0.01). Using constrained liners resulted in early impingement on the superior part of the glenoid neck in the normal glenosphere, whereas glenoid lateralization increased impingement-free ROM. This RSA computer simulation model demonstrated that constrained humeral liners led to decreased impingement-free ROM. However, using lateralized glenosphere improved abduction ROM.

DUAL-MOBILITY BEARINGS ARE NO PANACEA IN REVISION TOTAL HIP ARTHROPLASTY FOR RECURRENT DISLOCATION: A SINGLE-CENTRE EXPERIENCE OF 100 UNSTABLE HIPS

Dual-mobility (DM) bearings are effective to mitigate dislocation in revision total hip arthroplasty (THA). However, data on its use for treating dislocation is scarce. Aim of this study was to compare DM bearings, standard bearings and constrained liner (CL) in revision THA for recurrent dislocation and to identify risk factors for re-dislocation.We reviewed 100 consecutive revision THAs performed for dislocation from 2012 and 2019. 45 hips (45%) received a DM construct, while 44 hips (44%) and 11 hips (11%) had a standard bearing and CL, respectively. Rates of re-dislocation, re-revision for dislocation and overall re-revision were compared. Radiographs were assessed for cup positioning, restoration of centre of rotation, leg length and offset. Risk factors for re-dislocation were determined by cox regression analysis. Modified Harris hip scores (mHHS) were calculated. Mean follow-up was 53 months (1 to 103).DM constructs were used more frequently in elderly patients (p=0.011) and hips with abductor deficiency (p&lt; 0.001). The re-dislocation rate was 11.1% for DM bearings compared with 15.9% for standard bearings and 18.2% for CL (p=0.732). Revision-free survival for DM constructs was 83% (95% CI 0.77 – 0.90) compared to 75% (95% CI 0.68 – 0.82) for standard articulations and 71% (95% CI 0.56 – 0.85) for CL (p=0.455). Younger age (HR 0.91; p=0.020), lower comorbidity (HR 0.42; p=0.031), smaller heads (HR 0.80; p=0.041) and cup retention (HR 8.23; p=0.022) were associated with re-dislocation. Radiological analysis did not reveal a relationship between restoration of hip geometry and re-dislocation. mHHS significantly improved from 43.8 points to 65.7 points (p&lt;0.001) with no differences among bearing types.Our findings suggest that DM bearings do not sufficiently prevent dislocation in revision THA for recurrent dislocation. Reconstruction of the abductor complex may play a key role to reduce the burden in these high-risk patients.

INCIDENCE, TREATMENT, AND OUTCOME OF MODERN DUAL MOBILITY DISSOCIATIONS

Dual mobility (DM) components are increasingly used to prevent and treat dislocation after total hip arthroplasty (THA). Intraprosthetic dissociation (IPD) is a known rare complication of these implants and has reportedly decreased with modern implants. The purpose of this paper is to report the diagnosis and treatment of modern DM IPD.1453 DM components were implanted between 2010 and 2021. 695 in primary and 758 in revision THA. 49 hips sustained a dislocation of the large head and 5 sustained an IPD at presentation. 6 additional IPD occurred at the time of reduction of large head. The average age was 64, 54% were female and the mean follow-up was three years. Of the 11 IPD, 8 had a history of instability, 5 had abductor insufficiency, 4 had prior lumbar fusion, and 3 were conversions from fracture.The overall IPD incidence was 0.76%. Ten of the 11 DM IPD were missed at initial presentation or at the time of reduction, and all were discharged with presumed reduction. The mean time from IPD to surgical treatment was 3 weeks. One patient died with an IPD at 5 months. A DM head was reimplanted in six, two underwent revision of the acetabular component with exchange of DM head, and four were revised to a constrained liner. The re-revision rate was 55% at a mean 1.8 years. None of the patients who underwent cup revision required subsequent re-revision while half of the constrained liners and exchange of DM heads required re-revision.The overall rate of DM dislocation or IPD is low. It is critical to identify an IPD on radiographs as it was almost universally missed at presentation or when it occurred iatrogenically. For patients presenting with IPD, the surgeon should consider acetabular revision and conversion to a constrained liner or a larger DM, with special attention to removing impinging structures that could increase the risk of re-dislocation.

Fully constrained acetabular liner vs. dual mobility hip joint in the surgical treatment of metastatic bone disease of the hip: study protocol for a randomized, open-label, two-arm, non-inferiority trial evaluating the post-operative hip dislocation rate

BackgroundPatients receiving total hip arthroplasty (THA) due to metastatic bone disease of the hip (MBD) are at an increased risk of post-operative joint dislocation compared to other populations. Different joint solutions have been developed with the purpose of reducing the dislocation risk compared to regular THAs. One of these solutions, the constrained liner (CL), has been used increasingly at our department in recent years. This design, however, is prone to polyethylene wear and higher revision rates. An alternative is the dual mobility cup (DM), which has been shown to reduce the risk of dislocation in other high-risk populations. Few studies have investigated DM for THA due to MBD, and no studies have directly compared these two treatments in this population. We therefore decided to conduct a trial to investigate whether DM is non-inferior to CL regarding the post-operative joint dislocation risk in patients receiving THA due to MBD.Materials and methodsThis study is a single-center, randomized, open-label, two-arm, non-inferiority trial. We will include 146 patients with MBD of the hip who are planned for THA at the Department of Orthopedic Surgery, Rigshospitalet. Patients with previous osteosynthesis or endoprosthetic surgery of the afflicted hip, or who are planned to receive partial pelvic reconstruction or total femoral replacement, will be excluded. Patients will be stratified by whether subtrochanteric bone resection will be performed and allocated to either CL or DM in a 1:1 ratio. The primary outcome is the 6 months post-operative joint dislocation rate. Secondary outcomes include overall survival, implant survival, the rate of other surgical- and post-operative complications, and quality of life and functional outcome scores.DiscussionThis study is designed to investigate whether DM is non-inferior to CL regarding the risk of post-operative dislocation in patients receiving THA due to MBD. To our knowledge, this trial is the first of its kind. Knowledge gained from this trial will help guide surgeons in choosing a joint solution that minimizes the risk of dislocation and, ultimately, reduces the need for repeat surgeries in this patient population.Trial registrationClinicalTrials.gov Identifier: NCT05461313. Registered on July 15 2022. This trial is reported according to the items in the WHO Trial Registration Data Set (Version 1.3.1).

Outcomes of total hip arthroplasty with a standard prosthesis for the affected hip in patients with poliomyelitis sequelae: a mid-term retrospective follow-up study

IntroductionTotal hip arthroplasty for poliomyelitis sequelae could be a technical challenge due to the higher risk for prosthetic dislocation and degenerative changes in the affected limbs. This study aimed to analyse the mid-term outcomes of primary total hip arthroplasty on the affected hip with standard prosthesis.Materials and MethodsFrom January 2008 to January 2018, 32 patients with poliomyelitis sequelae underwent total hip arthroplasty on the affected hip with standard prosthesis. Clinical and radiographical outcomes, complications, and prosthesis survival rates were evaluated.ResultsAfter a mean follow-up of 7.9 (4.4–13.1) years, the Harris Hip Score, University of California Los Angeles activity level rating, and 12-item Short Form Health Survey Questionnaire scale score significantly improved. The abduction and flexion motions of the hip joint improved dramatically, and the visual analogue scale pain score decreased significantly. The leg length discrepancy was effectively corrected. During the follow-up, one patient experienced prosthetic dislocation, one underwent revision surgery due to acetabular component loosening, two had osteolysis, four had heterotopic ossification, two experienced transient sciatic nerve palsy, and one had intermuscular vein thrombosis. The prosthesis survival rate was 96.9% at 5 years postoperatively. No periprosthetic infection occurred.ConclusionTotal hip arthroplasty with standard prosthesis could be an effective treatment for hip arthropathy on the affected hip of patients with poliomyelitis sequelae, resulting in good clinical outcomes and few complications. Constrained liner and dual mobility articulation are not recommended unless the hip muscle strength of the abductor is < III.

No difference in range of motion in reverse total shoulder arthroplasty using standard or constrained liners: a matched cohort study.

Prosthetic instability is one of the most common short-term complications following reverse total shoulder arthroplasty (RTSA). Numerous strategies exist to attempt to mitigate this complication, including utilization of constrained polyethylene humeral liners. A concern of constrained humeral liners is that they may come at the expense of restricted rotational range of motion (ROM). The purpose of the present study is to compare range of ROM and patient-reported outcomes (PROs), and satisfaction among matched cohorts using constrained vs. unconstrained liners after RTSA. A multicenter shoulder arthroplasty registry was retrospectively reviewed to identify patients with two-year clinical follow-up after RTSA with constrained liners used at the surgeon's discretion. All patients had the same inlay humeral prosthesis with a 135° neck shaft angle. This study cohort was matched 1:2 to control patients who underwent RTSA with standard liners based on age, sex, total glenoid-sided lateralization, glenosphere diameter, and surgery performed on the dominant arm. Improvement in PROs and ROM was compared between groups. Twenty-two patients were identified who underwent RTSA with a constrained humeral liner; these were compared to 44 matched patients with standard liners. The groups were found to have no notable differences in demographics, baseline PROs and ROM. At two years postoperatively, both cohorts demonstrated improvements in all PROs without statistically significant differences between the two groups. There were no differences between groups in improvement in any ROM measure, including forward flexion (constrained: 54°, standard: 57°, P=.771), external rotation at the side (constrained: 42°, standard: 41°, P=.906) or internal rotation at 90° of abduction (constrained: 24°, standard: 20°, P=.587). For an inlay humeral prosthesis with a 135° neck shaft angle, utilization of a constrained liner for RTSA demonstrates no significant difference in ROM or PROs compared to a well-matched cohort of patients who underwent RTSA with a standard polyethylene humeral liner. These are reassuring data for using constrained liners when there is intraoperative concern for prosthetic instability.

What is the failure rate of constrained liners in complex revision total hip arthroplasty?

Recurrent hip dislocation after multiple revision total hip arthroplasty is a severe complication. Therefore, constrained acetabular liners (CL) have been used during salvage procedures. We report our experience of constrained liners in a re-revision setting with focus on re-dislocation. We also evaluated acetabular and femoral bone loss as potential risk factor. Between January 2013 and December 2016, 65 patients were treated in a single institution for revision and re-revision hip arthroplasty using CL. The indication for using a CL was a high risk of re-redislocation after multiple recurrent hip dislocation including failed Dual Mobility Cups (DMC). Compromising soft tissue defects as well as severe bone defect were therefore regarded as high risks. Thirty-eight patients (77.6%) underwent a minimum of three surgical procedures before the index revision procedure. Sixteen patients (24.6%) were excluded as they were lost to follow-up, expired before minimum follow-up or refused study participation, leaving 49 patients in the analysis (75.4%). The mean follow-up was 62months (44-74; SD = 7.7). We assessed the following potential risk factors for revision or dislocation: type of surgical setting (septic/aseptic), BMI, cup inclination angle, size of liner used and acetabular and femoral bone loss according to Paprosky classification. The primary endpoints were dislocation or repeat revision for any reason. Of the 49 patients, we found an overall re-revision rate of 40.8% (20/49) and a dislocation rate of 30.6% (15/49). There were no significant differences among the surgical re-revision rate or dislocation rate as a factor of patient characteristics. In terms of bone loss, there was a trend towards higher revision rates for increasing acetabular and femoral bone loss, but without statistical significance. We found the use of a constrained liner in a re-revision setting still bears a high risk of re-revision and re-dislocation. Therefore we restrained from using constrained liners in favour of Dual mobility cups. In this study there was no significant higher dislocation rate in the subgroup of periprosthetic infection. Furthermore the rigid design of a constrained liner bears the known risk of structural failure of acetabular reconstruction implants. Severe acetabular or femoral bone defects seem to have an impact on the revision rate, but not on the dislocation rate with regards to the restored offset and center of the hip. Results have to be taken into context such that the study population inherently has a predisposition for poorer outcomes. Indications should be strongly filtered for patients at high risk for recurrent hip joint dislocation including failed DMCs with only limited bone loss and moderate soft tissue defects. Our modification to the existing classification with a high inter and intraobserver reliability will make future studies more comparable regarding revisions and bone stock loss. Still furtherresearch using objective and reproducible parameters is needed to better analyze data especially in the background of complex revision hip arthroplasty.

Does Revision of an Acetabular Shell With Insertion of an Uncemented Constrained Liner Confer Benefit Over Cementing Into a Well-Ingrown Shell?

BackgroundDuring revision total hip arthroplasty (THA), a constrained acetabular liner (CAL) may be inserted to enhance hip stability. It is unclear, however, whether cementation of a CAL into a retained cup offers an advantage compared to revision of the acetabular cup and insertion of an uncemented CAL. The purpose of our study was to compare outcomes and survivorship between the 2 methods. MethodsWe identified a total of 177 patients who underwent revision THA with a specific CAL at our center between July 2004 and May 2019 (114 cup revisions and insertion of an uncemented CAL, 63 cementations of a CAL into a retained cup). Kaplan-Meier (KM) survival analysis was performed for implant survival free from aseptic failure of the CAL for both cohorts. ResultsThe average follow-up time was 7.2 and 7.02 years for the cemented and uncemented cohort, respectively (P = .55). Five patients (7.93%) in the cemented CAL group experienced failure of the CAL, whereas 10 patients (8.77%) in the uncemented CAL cohort experienced failure (P = .21). Kaplan-Meier (KM) survival analysis demonstrated comparable survivorship at 10 years (P = .055). ConclusionThe results of our study suggest comparable survivorship between cementing a CAL into a retained cup and inserting an uncemented CAL in a revised acetabular cup. As a result of these findings along with the benefits associated with cementing a CAL, we encourage surgeons to readily consider this option in the management of recurrent instability.

Short term analysis of total hip replacement done with constrained acetabular component - functional and radiological outcome

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Dislocation remains at the forefront of complications after primary total hip arthroplasty (THA). In our study, we talk about the use of constrained liners and its outcomes in an unstable hip.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; The total number of patients included in the study was 15. The total number of hips in the study were 15. The age group of the patients varied between 51 years and 89 years with mean age group of 73 years. The most common indication in our study was dislocation contributing 60% (n=9) of the hips.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; The post-operative mean Harris hip score (HHS) at immediate post-operative was 67.6. There was a gradual improvement in the HHS through 6 months (77.6), one year (83.3), two years (86.7) and 3 years (90.33). There were no cases with post-operative septic or aseptic loosening in the radiological analysis. The mean cup inclination was 34.3. Out of the 13 hips, in eight hips the femoral stem was in varus. Five hips had a centrally placed femoral stem. Stability management in THA have seen the component design take centre stage, primarily with the use of larger diameter femoral heads and the rise in popularity of constrained acetabular liners (CAL). Several authors have done studies which talk about the stability of this implant design and the reliability of this implant in unstable hips and in hips where instability was expected.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; In our study, proximal femur tumours, dislocated total hips, abductor insufficiencies and aseptic loosening all showed good results.&lt;/p&gt;

Dual-Mobility Implants and Constrained Liners in Revision Total Hip Arthroplasty.

Instability remains the most common complication after revision total hip arthroplasty (THA). The purpose of this study was to determine whether there was a difference in aseptic revision rates and survivorship between dual-mobility (DM) and constrained liners (CL) in revision THA. We reviewed a consecutive series of 2432 revision THA patients from 2008 to 2019 at our institution and identified all patients who received either a CL or DM bearing. We compared demographics, comorbidities, indications, dislocations, and aseptic failure rates between the two groups. Bivariate and multivariate regression analyses were used to determine risk factors for failure, and a Kaplan-Meier survivorship analysis was performed with an aseptic re-revision as the endpoint. Of the 191 patients, 139 (72%) received a DM bearing, and 52 (28%) had a CL. At a mean follow-up of 14.3 months, there was no statistically significant difference in rates of dislocation (10.4% vs 14.0%, P= .667), aseptic revision (30.9% vs 46.2%, P= .073), or time to revision (3.78 vs 6 months, P= .565) between the two groups. The multivariate analysis revealed CL had no difference in aseptic re-revision rates when compared with DM (odds ratio 1.47, 95% confidence interval 0.84-2.52, P= .177). The survivorship analysis found no difference in aseptic failure between the groups at 12 months (P= .059). Both CL and DM bearings have high aseptic failure rates at intermediate term follow-up after revision THA. CL did show a higher risk of failure than DM bearings, but it was not statistically significant with the numbers available for this study. Further prospective studies are needed to determine the optimal treatment for recurrent instability.

Emerging Concepts in the Surgical Management of Peri-Acetabular Metastatic Bone Disease.

The pelvis is a common site of metastatic bone disease. Peri-acetabular lesions are particularly challenging and can cause severe pain, disability and pathologic fractures. Surgical management of these lesions has historically consisted of cementoplasty for contained lesions and Harrington reconstructions for larger, more destructive lesions. Due to the limitations of these procedures, a number of novel procedures have been developed to manage this challenging problem. Percutaneous techniques—including acetabular screw fixation and cementoplasty augmented with screws—have been developed to minimize surgical morbidity. Recent literature has demonstrated a reliable reduction in pain and improvement in function in appropriately selected patients. Several adjuncts to the Harrington procedure have been utilized in recent years to reduce complication rates. The use of constrained liners and dual mobility bearings have reduced the historically high dislocation rates. Cage constructs and porous tantalum implants are becoming increasingly common in the management of large bony defects and destructive lesions. With novel and evolving surgical techniques, surgeons are presented with a variety of surgical options to manage this challenging condition. Physicians must take into account the patients’ overall health status, oncologic prognosis and anatomic location and extent of disease when developing an appropriate surgical plan.