Survivorship Of Total Hip Arthroplasty Research Articles

Long-Term Survival of Total Hip Arthroplasty Using Implants From Different Manufacturers

BackgroundTotal hip arthroplasty (THA) can be performed using either femoral and acetabular components provided by the same manufacturer (matched components) or components from different manufacturers (unmatched components). We hypothesized that there would be no difference in outcomes following the use of unmatched compared to matched components. MethodsData from a nationwide joint registry, the New Zealand Joint Registry (NZJR), were analyzed to assess long-term outcomes of using unmatched implants in THA. ResultsThe NZJR has recorded a total of 108,613 primary THAs. We excluded combinations with less than 50 implantations, leaving 99,732 arthroplasties (90.5%). The unmatched group consisted of 24,537 (24.6%) THAs. Revision procedures were required in 3434 (4.6%) of the matched group, at a rate of 0.72/100 component years and 1078 (4.4%) of the unmatched group, a rate of 0.69/100 component years (P = .049). THAs with metal-on-metal or ceramic-on-metal bearings were overrepresented in the matched group. When analysis was repeated with these implants excluded, there was no longer a difference in revision rate between groups (4.0% revisions, 0.65/100 component years and 4.3% revisions, 0.67/100 component years [P = .742]).Survival analysis showed 17-year survival for matched components and unmatched to be within 95% confidence intervals at all time points.There was a small, statistically significant improvement in Oxford Hip Scores for the unmatched group compared with the matched group. ConclusionData from the NZJR confirm that the use of unmatched components in THA has no adverse effect on outcomes.

Survivorship and complications of total hip arthroplasty in patients with dwarfism.

Total hip arthroplasty (THA) is a common procedure used to treat bony hip deformities and skeletal dysplasia in dwarfism. These surgeries are often more difficult than conventional THA as they may involve malformed joints and poor bone quality, and may require smaller prostheses. This study aims to investigate whether implant survivorship and revision rates vary among patients with and without dwarfism undergoing THA. A retrospective case-control study was performed for 102 THAs completed between 1997 and 2014 in patients under the height threshold of 147.32 cm. This cohort was matched 1:1.5 with patients of normal height with respect to age, gender, year of surgery, and Charlson comorbidities. All cases had a minimum follow-up of 1 year. A chart review was performed to identify patient and surgical characteristics, including outcomes. Radiographs were assessed for deformity, loosening, and periprosthetic fractures among other factors. The 2-, 5-, and 10-year survivorship of THA in patients with dwarfism was 92.9%, 92.9%, and 80.7%, respectively; and 94.4%, 86.4%, and 86.4% for controls, respectively (p = 0.95). The dwarfism cohort demonstrated an OR of 3.81 and 3.02 for revision for periprosthetic fractures (p = 0.11) and mechanical wear (p = 0.21), respectively. THA in patients with dwarfism achieves comparable results to a non-dwarfism population with regards to implant survivorship; however, there is a trend toward increased periprosthetic fractures and wear-related failures. Surgeons should be aware of this potentially higher risk in this population and take morphological differences into account during surgical planning and technique.

A retrospective study on the relationship between altered native acetabular angle and vertical implant malpositioning.

Acetabular cup positioning in extreme angles of vertical position affects both stability and long-term survivorship of total hip arthroplasty. The purpose of this study is to determine whether native Sharp's angle is associated with an increased abduction angle of the acetabular component. Consecutive patients who underwent primary total hip replacement between February 2012 and August 2015 were included. Vertical positioning of acetabular implant in the antero-posterior post-operative radiographs were measured. The proportion of implants positioned outside the safe zone (40°±10°) was calculated and through a multivariate analysis, Sharp's angle and other factors possibly associated with cup malpositioning were evaluated. Five hundred twenty-eight hip arthroplasties were analyzed. Prevalence of cup malpositioning was 7.6% and 25 patients had an altered native acetabular angle. An altered pre-operative Sharp's angle was associated with a higher risk of vertical malpositioning of the acetabular component (OR 2.51 IC 95%: 1.17-5.39) (p=0.02). Body mass index, surgeon's volume, size of the implant, gender, pre-operative diagnose and age, were not associated with the position of the cup. The alteration of the Sharp's angle as an indicator of hip dysplasia in native hips increases the odds of acetabular cup malpositioning. Other factors explored did not correlate with the position of the acetabular prosthesis. Systematic assessment of Sharp's angle should be included in the pre-operative planning of primary hip arthroplasty.

Relative impact of hospital and surgeon procedure volumes on primary total hip arthroplasty revision: a nationwide cohort study in France.

BackgroundBoth surgeon and hospital procedure volumes have been found to be associated with total hip arthroplasty (THA) outcomes. However, little research has been conducted on the relative influence. We studied the association between THA survivorship and both hospital and surgeon procedure volumes, considering their relative impact.MethodsA population-based cohort included all patients aged ≥40 years having received a unilateral primary THA from 2010 to 2011, from the French National Health Insurance Database. Patients were followed up until the end of 2014. The outcome was THA revision. Exposures of interest were procedure volumes, divided into tertiles: <1.5, 1.5-4, >4 and <7, 7-15, >15 procedures per month defined as low, medium, and high volumes for surgeon and hospital, respectively.ResultsThe cohort had 62,906 patients, with mean age 69 years and women 57%. Mean surgeon and hospital volumes were 8 and 23 procedures per month, respectively, and 5%, 72%, 22% and 7%, 28%, 65% of THAs were implanted by a low-, medium-, and high-volume surgeon or in a low-, medium-, and high-volume hospital, respectively. Median follow-up was 45 months (range, 0-57 months). In multivariate analysis, adjusted for both surgeon and hospital volumes, for patient and THA characteristics, a lower surgeon volume was associated with poorer THA survivorship (adjusted hazard ratio [aHR] = 1.19; 95% confidence interval [CI], 1.07-1.34 and aHR = 1.70; 95% CI, 1.40-2.05, for medium- and low-volume surgeon, respectively, compared with that of high volume), whereas hospital volume was not.ConclusionsThis study brings evidence to support the notion that THAs performed by high-volume surgeons in French private hospitals have higher survivorship in the first 4 years.

Long-Term Results of Cementless Total Hip Arthroplasty Using a Modular Stem in Patients with Femoral Head Osteonecrosis

Patients with femoral head osteonecrosis are younger and more active than those with osteoarthritis of the hip. More than 10-year results of total hip arthroplasty (THA) using modular cementless stem in osteonecrotic patients have not yet been reported. We determined clinical and radiologic results of cementless modular stem in a consecutive series of patients with femoral head osteonecrosis a minimum follow-up of 10 years. We retrospectively reviewed 48 patients (58 hips) who underwent THA for femoral head osteonecrosis with a cementless modular femoral stem. Metal-on-metal articulation was used in 32 hips and ceramic-on-ceramic articulation in 26. There were 26 men and 22 women with a mean age of 52 years at the time of the operation. These patients were followed for 10 to 15 years. All of the acetabular cups and femoral stems had radiographic evidence of bone ingrown stability at the final follow-up. Three hips were revised due to infection. There were no revisions for ceramic fracture or adverse reaction to metal debris. The survival rate was 94.8% (95% confidence interval: 89.8–100%). However, 12 patients (12 hips, 21%) suffered thigh pain. In six patients (six hips), the pain disappeared within 1 to 2 years, whereas the pain persisted until the final follow-up in the remaining six patients. As of 10 to 15 year, radiologic results and survival of THA using a modular femoral stem were good in patients with osteonecrosis. However, the incidence of thigh pain remains a matter of concern.

Systematic review: lack of evidence for the success of revision arthroplasty outcome in younger patients.

Total hip arthroplasties (THAs) in younger patients are becoming increasingly popular. However, the outcome of subsequent revisions in younger patients is not well known and, therefore, their success (subsequent revision prosthesis survival) might be overestimated. We investigated available data on the outcome of primary- and subsequent revision THAs performed in the same cohort of patients who underwent primary THA under the age of 50. Medline, Embase and the Cochrane Library (CENTRAL) were searched up until April 13, 2016 for studies that reported both the survival of primary and subsequent revisions THA of single cohorts of patients younger than 50. Eligible articles had to include Kaplan Meier analysis or competing risk analysis for survival of the primary THA at a mean follow-up of 10 years, as well as for the subsequent revision THA within the same cohort. We found 4,799 unique records; 43 of which were potentially eligible. Only 1 paper met our inclusion criteria. It reported on the survival of 69 primary prostheses at a mean of more than 10 years follow-up and 13 subsequent revisions. There is a clear lack of evidence about the outcomes of the revision arthroplasty in younger patients. Only 1 study reported the survival-rate of subsequent revision arthroplasty with the minimum 10-year survival rate of the original THA cohort. In the future, this serious lack of knowledge could result in a large number of patients with no further reconstructive options after failed THA, and a large medical burden for society.

Incidence of Ceramic Liner Malseating After Ceramic-on-Ceramic Total Hip Arthroplasty Associated With Osteolysis: A 5- to 15-Year Follow-Up Study

BackgroundThe aim of our study was to evaluate the clinical and radiographic outcomes of malseating of the acetabular liner in ceramic-on-ceramic total hip arthroplasty (THA). MethodsOutcomes for 160 ceramic-on-ceramic THAs, contributed by 116 women and 39 men, were evaluated. Clinical and radiographic measurements were obtained over a 5- to 15-year follow-up for analysis. ResultsLiner malseating was identified in 20% of cases. Outcomes for 32 cases with liner malseating (group A) were compared to outcomes for 128 joints with correct liner seating (group B). The Harris hip score at the last follow-up was 90.1 for group A and 89.6 for group B. Osteolysis was identified in 5 cases in group A (15.6%), compared to 3 cases in group B (P < .001). No significant between-group differences were identified with regard to ceramic fracture, audible squeaking, loosening of components, and revision THA. The mean annual liner wear rate was comparable between groups, 0.0045 mm/y for group A and 0.0039 mm/y for group B. The 10-year Kaplan-Meier survivorship, based on an end point of revision THA, was 100% for group A and 99.0% for group B. ConclusionOver a moderate-length follow-up of 5-15 years, malseating of the acetabular liner was not associated with negative clinical outcomes or THA survivorship. Malseating did increase the incidence of osteolysis, a risk factor for adverse effects. Long-term follow-up studies are needed to fully quantify the effects of malseating of the acetabular liner.

Total hip arthroplasty survival in femoral head avascular necrosis versus primary hip osteoarthritis: Case-control study with a mean 10-year follow-up after anatomical cementless metal-on-metal 28-mm replacement

BackgroundTotal hip arthroplasty is the most widely used procedure to treat avascular necrosis (AVN) of the femoral head. Few studies have compared the outcomes of THA in femoral head AVN and primary hip osteoarthritis. Therefore we performed a case-control study to compare THA for femoral head AVN vs. primary hip osteoarthritis in terms of: (1) prosthesis survival, (2) complication rates, (3) functional outcomes and radiographic outcomes, (4) and to determine whether specific risk factors for THA failure exist in femoral head AVN. HypothesisTHA survival is similar in femoral head AVN and primary hip osteoarthritis. Material and methodsWe compared two prospective cohorts of patients who underwent THA before 65 years of age, one composed of cases with femoral head AVN and the other of controls with primary hip osteoarthritis. In both cohorts, a cementless metal-on-metal prosthesis with a 28-mm cup and an anatomical stem was used. Exclusion criteria were THA with other types of prosthesis, posttraumatic AVN, and secondary osteoarthritis. With α set at 5%, to obtain 80% power, 246 patients were required in all. Prosthesis survival was assessed based on time to major revision (defined as replacement of at least one implant fixed to bone) and time to aseptic loosening. The other evaluation criteria were complications, Postel-Merle d’Aubigné (PMA) score, and the Engh and Agora Radiographic Assessment (ARA) scores for implant osseointegration. ResultsThe study included 282 patients, 149 with AVN and 133 with osteoarthritis. Mean age was 47.8±10.2 years (range, 18.5–65) and mean follow-up was 11.4±2.8 years (range, 4.5–18.3 years). The 10-year survival rates were similar in the two groups: for major revision, AVN group, 92.5% (95% confidence interval [95% CI], 90.2–94.8) and osteoarthritis group, 95.3% (95% CI, 92.9–97.7); for aseptic loosening, AVN group, 98.6% (95% CI, 97.6–98.6) and osteoarthritis, 99.2% (95% CI, 98.4–100). The AVN group had higher numbers of revision for any reason (19 vs. 6, P=0.018) and for dislocation (8 vs. 1, P=0.031). Mean PMA scores at last follow-up were comparable in the AVN group (17.65±1.27 [range, 10–18]) and osteoarthritis group (17.59±1.32 [range, 14–18]) (P=0.139). Osseointegration was also similar in the two groups: global Engh score, 26.51±1.81 (range, 14–27) for AVN and 26.84±0.91 (range, 19.5–27) for osteoarthritis (P=0.065); femoral ARA score, 5.83±0.46 (range, 3–6) for AVN and 5.90±0.42 (range, 3–6) for osteoarthritis (P=0.064); and cup ARA score, 5.74±0.67 (range, 3–6) for AVN and 5.78±0.66 (range, 3–6) for osteoarthritis (P=0.344). DiscussionSurvival in this study was good and consistent with recent data on AVN, with no difference between AVN and osteoarthritis. Revisions for any cause or for dislocation were more common after THA for AVN. Functional outcomes were similar in the AVN and osteoarthritis groups. An anatomical cementless prosthesis combined with metal-on-metal 28-mm bearing provides durable good outcomes. Level of evidenceIII, non-randomized comparison of two prospective cohorts.

Ceramic bearings with bilayer coating in cementless total hip arthroplasty. A safe solution. A retrospective study of one hundred and twenty six cases with more than tenyears' follow-up.

Using a ceramic-ceramic bearings, cementless total hip arthroplasty (THA) has provided good clinical results. To ensure longevity a good quality fixation of the implants is mandatory. Different surface treatments had been used, with inconsistent results. We hypothesized that a "bilayer coating" applied to both THA components using validated technology will provide a long-lasting and reliable bone fixation. We studied the survival and bone integration of a continuous, single-surgeon, retrospective series of 126 THA cases (116 patients) with an average follow-up of 12.2years (minimum 10years). The THA consisted of cementless implants with a bilayer coating of titanium and hydroxyapatite and used a ceramic-ceramic bearing. With surgical revision for any cause (except infection) as the end point, THA survival was 95.1% at 13years. Stem (98.8%) and cup (98.6%) survival was similar at 13years. Bone integration was confirmed in 100% of implants (Engh-Massin score of 17.42 and ARA score of 5.94). There were no instances of loosening. Revisions were performed because of instability (1.6%), prosthetic impingement or material-related issues. A bilayer titanium and hydroxyapatite coating provides strong, fast, reliable osseo integration, without deterioration at the interface or release of damaging particles. The good clinical outcomes expected of ceramic bearings were achieved, as were equally reliable stem and cup fixation.

Revision Total Hip Arthroplasty Using an Acetabular Reinforcement Ring With a Hook: A Precise Follow-Up, at Average 11.4 Years, of a Previous Report

BackgroundThis study aims at determining the average long-term result of revision total hip arthroplasty (THA) using the acetabular reinforcement ring with a hook (ARRH) and bone grafting in severe acetabular bony defect. Expected 15-year survival of ARRH in revision THA is included in the study. MethodsRetrospective review of 48 patients (48 hips) with follow-up duration of average 11.4 years (range, 6.1-21.4 years) was conducted. At each follow-up, Harris hip score was used to assess functional outcome, and radiographic acetabular component osteolysis was measured by DeLee and Charnley classification. Bone defects were assessed preoperatively and intraoperatively using American academy of orthopedic surgeons and Paprosky classification. The common modes of ARRH failures were evaluated. Bone consolidation, presence of heterotopic ossification, and complications such as infection and dislocation were recorded. ResultsThe bone defects were varied and included cavitary, segmental, and combined defects without any pelvic discontinuity. Mean Harris hip score improved from 52.6 points preoperatively to 82.0 points postoperatively. Nine acetabular revisions and 3 stem revisions (2 concurrent with acetabular revisions and 1 isolated stem revision) were performed. There were 5 infected cases and 1 patient with recurrent dislocation. The 11.4-year survival of revision THA with ARRH was 71% as the end point for acetabular revision surgery for any reason. The expected 15-year survival of revision THA with ARRH was 60%. The most common failure mode of ARRH was superomedial migration followed by lateral migration. ConclusionARRH combined with bone grafting produces relatively good average long-term clinical results.

Long-term Results of a First-Generation Annealed Highly Cross-Linked Polyethylene in Young, Active Patients.

The survivorship of total hip arthroplasty in younger patients is dependent on the wear characteristics of the bearing surfaces. Long-term results with conventional polyethylene in young patients show a high failure rate. This study assessed the long-term results of a first-generation annealed highly cross-linked polyethylene (HCLPE) in uncemented total hip arthroplasty in young, active patients. Between 1999 and 2003, 112 total hip arthroplasty procedures performed in 91 patients with an average University of California Los Angeles activity score of 8 and mean age of 53 years (range, 24-65 years) were included from a prospective database. In all patients, a 28-mm metal femoral head on annealed HCLPE (Crossfire; Stryker, Mahwah, New Jersey) was used. At minimum 10-year follow-up (11.5±0.94 years), Kaplan-Meier survivorship was 97% for all failures (1 periprosthetic infection and 1 late dislocation) and 100% for mechanical failure (no revisions for osteolysis or loosening). This study showed low revision rates for wear-related failure and superior survivorship in young, active patients. Oxidation causing failure of the locking mechanism has not been a problem with Crossfire for up to 10 years.

The Absence of Hydroxyapatite Coating on Cementless Acetabular Components Does Not Affect Long-Term Survivorship in Total Hip Arthroplasty

BackgroundHydroxyapatite (HA) has been applied to joint prostheses as a bioactive coating to prolong their durability. However, HA benefits for cup survival in total hip arthroplasty (THA) remain controversial. In this study, we compared the survival of cups with and without HA coating during a minimum follow-up of 18 years. MethodsIn total, 183 THA cases in 163 patients were analyzed, including 73 cups with HA coating (HA+ group) and 110 without HA coating (HA− group); otherwise, the cups had identical titanium-sprayed rough surfaces and were fixed with screws. In both groups, the same conventional polyethylene liners were applied. Zirconia and alumina ceramic heads were used in the HA+ and HA− groups, respectively. We retrospectively analyzed cup survival based on cup revision for any reason or aseptic loosening as end points. ResultsIn total, 7 and 8 revisions were performed in the HA− and HA+ groups with survival rates of 86.3% and 90.1%, respectively. Among them, 3 cups in the HA− group and 1 cup in the HA+ group were revised for aseptic loosening in 20 years (survival rates 94.1% and 98.7%, respectively). No significant difference was detected in cup survival rates between the groups based on both end points. There were no stem revisions during the observation period. ConclusionThe results suggested that HA coating did not have either beneficial or adverse effects on the long-term cup survival in primary cementless THA.

Missed low-grade infection in suspected aseptic loosening has no consequences for the survival of total hip arthroplasty

Background and purpose — Aseptic loosening and infection are 2 of the most common causes of revision of hip implants. Antibiotic prophylaxis reduces not only the rate of revision due to infection but also the rate of revision due to aseptic loosening. This suggests under-diagnosis of infections in patients with presumed aseptic loosening and indicates that current diagnostic tools are suboptimal. In a previous multicenter study on 176 patients undergoing revision of a total hip arthroplasty due to presumed aseptic loosening, optimized diagnostics revealed that 4–13% of the patients had a low-grade infection. These infections were not treated as such, and in the current follow-up study the effect on mid- to long-term implant survival was investigated.Patients and methods — Patients were sent a 2-part questionnaire. Part A requested information about possible re-revisions of their total hip arthroplasty. Part B consisted of 3 patient-related outcome measure questionnaires (EQ5D, Oxford hip score, and visual analog scale for pain). Additional information was retrieved from the medical records. The group of patients found to have a low-grade infection was compared to those with aseptic loosening.Results — 173 of 176 patients from the original study were included. In the follow-up time between the revision surgery and the current study (mean 7.5 years), 31 patients had died. No statistically significant difference in the number of re-revisions was found between the infection group (2 out of 21) and the aseptic loosening group (13 out of 152); nor was there any significant difference in the time to re-revision. Quality of life, function, and pain were similar between the groups, but only 99 (57%) of the patients returned part B.Interpretation — Under-diagnosis of low-grade infection in conjunction with presumed aseptic revision of total hip arthroplasty may not affect implant survival.

Total Hip Arthroplasty After Acetabular Fracture Is Associated With Lower Survivorship and More Complications

Despite modern fracture management techniques allowing for near anatomic reduction of acetabular fractures, there continues to be a risk of posttraumatic arthritis and need for total hip arthroplasty (THA). Few well-controlled studies have compared THA after acetabular fractures with THAs performed for other indications in terms of survivorship or complications, and none, to our knowledge, present 10-year survivorship data in this setting. (1) How does the 10-year survival of THA compare between those patients who underwent THA after an acetabular fracture and those who underwent THA for primary arthritis or avascular necrosis (AVN)? (2) Is there an increased risk of serious complications like infection, dislocation, and aseptic loosening as well as heterotopic ossification associated with a THA performed after a previous acetabular fracture? This retrospective case-control study compared findings of patients who underwent THA after acetabular fracture versus a matched cohort of patients who had received a primary THA for primary osteoarthritis or AVN. Between 1987 and 2011, we performed 95 THAs after acetabular fracture; of those, 74 (78%) met inclusion criteria and had documented followup beyond 2 years in our institutional registry. We selected 74 matched patients based on an algorithm that matched patients based on preoperative diagnosis, date of operation, age, gender, and type of prosthesis. During this time, we performed approximately 8000 THAs that were potentially available for matching based on complete followup beyond 2 years. We compared cases and control subjects using the Kaplan-Meier survivorship estimator as well as a comparison of the proportions in each group that developed major complications (including infection, dislocation, loosening, and heterotopic ossification) based a retrospective chart review. The 10-year survivorship after THA was lower in patients with a previous acetabular fracture than in the matched cohort (70%, 95% confidence interval [CI], 64%-78%, versus 90%, 95% CI, 86-95%; p < 0.001). There was no difference in the 10-year survival rate for those patients whose acetabular fracture was initially treated conservatively and those treated by open reduction and internal fixation. Patients with previous acetabular fracture had a higher likelihood of developing infection (7% [five of 74] versus 0% [zero of 74]; odds ratio [OR], 11.79; p = 0.028), dislocation (11% [eight of 74] versus 3% [two of 74]; OR, 4.36; p = 0.048), or heterotopic ossification (43% [32 of 74] versus 16% [12 of 74]; OR, 3.93; p < 0.001). In this case-control study, patients with a prior acetabular fracture had markedly inferior 10-year survivorship and more frequent serious complications when compared with patients undergoing THA for primary osteoarthritis or AVN. Given these findings, management of these complex cases should be in highly specialized units where the expertise of arthroplasty and trauma reconstruction is available. Level III, therapeutic study.

Dual mobility cup in revision total hip arthroplasty: Dislocation rate and survival after 5 years

BackgroundDislocation is a common complication of total hip arthroplasty (THA), particularly when performed as revision surgery. Dual mobility cups (DMCs) minimize the risk of instability when implanted during primary THA. However, their usefulness and survival in revision THA remain unclear. We therefore conducted a retrospective study to assess DMC stability and survival at a minimal follow-up period of 5years after revision THA. HypothesisThe dislocation rate associated with DMCs for revision THA is similar to that seen after primary THA. Materials and methodsCup exchange with implantation of a DMC was performed in 71 patients (74 hips) between 2000 and 2007, for the following reasons: recurrent dislocation (n=22), aseptic loosening (n=38), and infection (n=14). The DMCs were cemented in 47 cases and cementless in 27 cases. The clinical variables (Merle d’Aubigné-Postel score and Harris Hip Score) and radiological findings were collected retrospectively from the medical records and compared with those obtained at the last follow-up visit. ResultsOf the 74 cases, 2 were lost to follow-up. At last follow-up, the mean Merle d’Aubigné-Postel score was 15.2 (11–18) and the mean Harris Hip Score was 80.4 (51–98). Of the 8 failures, 2 (2/72, 2.7%) were related to mechanical factors (1 case each of aseptic loosening and dislocation) and 6 were changed because of infection (recurrent infection, n=4). Mechanical failure was not linked to a specific reason for revision THA. A radiolucent line was visible in 4 cases but this finding was not associated with clinical manifestations. When failure was defined as cup revision for any non-infectious complication, 5-year implant survival was 99% (95% confidence interval, 93–100%). DiscussionUse of a DMC in revision THA was associated with a slightly higher dislocation rate (1/72, 1.4%) than in primary THA, whereas 5-year survival was comparable. Cemented DMCs were not associated with a greater risk of loosening. ConclusionDMCs are useful to decrease the risk of dislocation in revision THA performed for any reason. The low rate of loosening indicates that DMCs do not result in high stresses at the bone-implant interface. Level of evidenceIV, retrospective study.

Total Hip Arthroplasty in Haemophilic Patients with Modern Cementless Implants

Hip arthropathy due to recurrent haemarthrosis in patients with haemophilia can be disabling. When severe degeneration occurs, total hip arthroplasty is indicated. Reported outcomes are variable and out of date. The aim of this study is to evaluate the survivorship of Total Hip Arthroplasty performed in a patient population with modern cementless implants. Twenty-three haemophilic patients were treated and followed by a multidisciplinary team dedicated to haemophilia. The mean age was 40.6years. No failures or complications were recorded at a mean follow-up of 8.1years (range: 3.1–13.7). A multidisciplinary team and the use of modern cementless implants may represent the keys to achieve good outcomes, fewer complications, and better survivorship in the approach to these difficult cases.

Does Previous Osteotomy Compromise Total Hip Arthroplasty? A Systematic Review

Hip osteotomy surgery has increased over the past several years, yet the impact of these procedures on subsequent total hip arthroplasty (THA) remains controversial. The purpose of this study was to perform a systematic review of the literature to determine the clinical results, procedure complications, and survivorship of THA following previous hip osteotomy. Ten studies met inclusion criteria. The operative time and estimated blood loss were higher in the post-osteotomy cohorts; while the clinical results and survivorship between groups were similar. THA following previous pelvic and femoral osteotomy provides pain relief and improved function with similar complication rates, clinical outcomes, and survivorship compared to hips undergoing routine primary THA. These procedures can be technically more demanding with increased operative times and intraoperative blood loss.

The Predictive Value of Radiostereometric Analysis for Stem Survival in Total Hip Arthroplasty. A Systematic Review

The high precision of radiostereometric analysis (RSA) has enabled us to predict long-term implant survival with a small sample of patients followed for a relatively short period of time. The purpose of our systematic review was to validate the predictive value of two-year RSA results on long-term survival of different types of primary total hip arthroplasty stems. We systematically reviewed literature to determine the maximum total point motion (MTPM), distal migration and rotation of stem designs and correlated these values to survival rates for aseptic loosening of these specific stems in arthroplasty registries. We included 32 studies describing migration of 15 different stem designs. The mean MTPM for straight polished cemented stems was 1.35 mm, for other cemented stems 0.83 mm and for other uncemented stems 1.50 mm. No data were available for the uncemented collared stem. Mean distal migration for straight polished cemented stems was 1.24 mm, for other cemented stems 0.26 mm, the uncemented collared stem 0.40 mm and for other uncemented stems 0.66 mm. Internal rotation was presented for 13 stems and all stems rotated into retroversion. All stems showed 10-year survival rates of >97% corrected for aseptic loosening. Reporting RSA results in a universal way including interpretation of outliers could improve the predictive value of RSA, allowing this technique to be an important tool during the phased introduction of new implant designs. However, a quality assessment of the data by an experienced reviewer is essential.

Total Hip Arthroplasty for the Sequelae of Legg-Calvé-Perthes Disease

The durability and risks associated with total hip arthroplasty (THA) for patients with a history of Legg-Calvé-Perthes disease (LCPD) are not well known. We sought to (1) determine the survivorship of THAs performed for LCPD; (2) assess hip scores and complications associated with THA in this patient population; and (3) compare results between patients who had undergone surgery in childhood with patients who had conservative treatment. We reviewed 99 primary THAs performed in 95 patients with a history of LCPD with minimum 2-year followup (mean ± SD, 8 ± 5 years). Mean age at THA was 48 ± 15 years. A total of 10 revisions were performed. Using revision for any reason as the end point, the 8-year survival rate was 90% (95% confidence interval [CI], 76%-96%) for cementless implants compared with 86% (95% CI, 57%-96%) for hybrid implants. The mean Harris hip score improved by 31 ± 16 (n = 76). Complications occurred in 16% of hips. The most common major complication was intraoperative fracture (eight femoral, one acetabular). Three patients developed sciatic nerve palsy after a mean lengthening of 2.2 ± 1 cm compared with a mean of 1.4 ± 1 cm in patients with intact sciatic nerve (p = 0.3). Cementless THAs for the sequelae of LCPD demonstrate 90% survival from any revision at 8 years followup. THAs for the sequelae of LCPD can be complicated and technically difficult. Intraoperative fractures and nerve injuries are common. Care should be taken to avoid excessive limb lengthening.

Results of Total Hip Arthroplasty Differ in Subtypes of High Dislocation

In a previous study, we described two subtypes of high dislocation of the hip depending on the presence (C1) or absence (C2) of a false acetabulum, yet we have already presented the concise followup of total hip arthroplasty (THA) in these patients as a group at a minimum of 15 years. In this retrospective study, we investigated differences in the results of THA in the C1 and C2 subtypes of high dislocation such as (1) survivorship of the reconstructions; (2) Merle d'Aubigné-Postel clinical scores; (3) leg lengthening and femoral shortening; and (4) site of reattachment and union rate of the greater trochanter. We included 49 hips of the C1 subtype and 30 hips of the C2 subtype operated on from 1976 to 1994. We evaluated survivorship (using reoperation for any reason as the end point) and performed chart and radiographic reviews. The 15-year survival was 84% (± 10% [95% CI]) for the C1 subtype and 60% (± 17% [95% CI]) for the C2 subtype (p = 0.001). Cox regression analysis, after adjustment for confounding factors, showed also statistically significantly worse survivorship in the C2 subtype (p = 0.021) and, after adjustment for possible predictive factors, found a statistically significant relationship of high dislocation subtype (p = 0.018) and trochanteric union (p = 0.005) with survival of THAs. Pain, function, and mobility scores improved from preoperative to last followup in C1 and C2 groups but they did not differ between C1 and C2 hips. C2 hips were lengthened more (p < 0.001) despite greater amounts of femoral shortening (p = 0.006). Site of reattachment and the risk of greater trochanter nonunion were not different between the groups. We found important differences in fundamental parameters after THA in the high-dislocation subtypes, including the risk of revision, which was higher in patients whose hips did not have a false acetabulum. These findings indicate that while reporting THA results in patients with high dislocation, mixing results of the two subtypes may lead to statistical bias.