Excellent 20-Year Results of Total Hip Arthroplasty With Highly Cross-Linked Polyethylene on Cobalt-Chromium Femoral Heads in Patients ≤50 Years.

BACKGROUND: Highly cross-linked polyethylene (HXLPE) acetabular bearing surfaces have appeared to offer excellent wear resistance, low incidence of wear-related osteolysis, and high implant survivorship at 10-year to 15-year follow-up. However, concerns over potential performance deterioration at longer-term follow-up remain - particularly in younger patients - and outcome data into the third decade have not been available. METHODS: We retrospectively assessed 62 patients (68 hips) who underwent primary total hip arthroplasty (THA) at age ≤50 years with a single manufacturer's cementless components, remelted HXLPE liner, and small diameter (26 and 28 millimeter) cobalt-chromium (CoCr) femoral heads at minimum 18-year follow-up. We assessed clinical outcomes (modified Harris Hip score, University of California Los Angeles Activity Score, polyethylene wear rates, radiographic findings (osteolysis, component loosening), and implant survivorship. RESULTS: At 20.6-year mean follow-up (range, 18 to 23 years) modified Harris Hip scores for surviving hips remained an average of 41 points above preoperative baseline (49 versus 90, P < .001) and UCLA scores 2.8 points above baseline (3.7 versus 6.4, P < .001). Wear analysis revealed a population linear wear rate of 0.0142 mm/y (standard deviation (SD), 0.0471) and volumetric wear rate of 10.14 mm3/y (SD, 23.41). Acetabular lysis was noted in 2 asymptomatic hips at 16.6 and 18.4 years. No components were radiographically loose. Survivorship free from wear-related revision was 100% at 20 years (97% free from any revision). CONCLUSION: The HXLPE-CoCr bearing couple with small femoral heads continues to be extremely effective 20 years after primary THA in the younger patient population.

Ten Year Outcomes of Contemporary Total Hip Arthroplasty in Adolescent and Young Adult Patients are Favorable.

BACKGROUND: The purpose of this study was to assess 10-year patient-reported outcome measures, complications, polyethylene wear-rates, and implant survivorships in patients ≤30 years of age treated with contemporary total hip arthroplasty (THA). METHODS: We retrospectively assessed 121 patients (144 hips) who underwent THA at age ≤30 years (mean 23 [range, 11 to 30]) at an average follow-up duration of 10.7 years (range, 8 to 17). Highly-crosslinked polyethylene acetabular liners were used in all cases. Femoral heads were ceramic (74%) or cobalt-chrome (26%). There were 52 hips (36%) that had previous surgery and 31 hips (22%) were in patients who had associated major systemic comorbidities. We analyzed the modified Harris Hip scores, University of California Los Angeles Activity Scores, major complications, polyethylene wear-rates, and implant survivorships. RESULTS: At final follow-up, the average modified Harris Hip scores improved from 47 (±15.1) to 81 (±19.5) with an average 34-point improvement. The University of California Los Angeles scores improved from 4.0 (±2.3) to 6.0 (±2.4). The major complication rate was 5.6%. There were 6 hips (4.2%) that were revised. Indications for revision included instability (3, 2.1%), late infection (1, 0.7%), liner dissociation (1, 0.7%), and acetabular loosening (1, 0.7%). Mean linear (0.0438 mm/y) and volumetric (29.07 mm3/y) wear rates were low. No periprosthetic osteolysis was detected in any hip. Survivorship free from revision for any reason was 97.2, 95.8, and 95.8% at 5, 10, and 15 years. CONCLUSIONS: Contemporary THA in patients ≤30 years of age is associated with marked clinical improvements at 10-year follow-up and encouraging survivorship estimates at 15 years.

Mean 16-Year Results of Total Hip Arthroplasty With Alumina Ceramic Femoral Heads on Highly Cross-Linked Polyethylene in Patients 50 Years or Less.

BACKGROUND: Highly cross-linked polyethylene (HXLPE) is a widely used bearing surface in total hip arthroplasty (THA); long-term results in young patients are limited. We previously demonstrated excellent results in HXPLE on cobalt-chrome femoral heads at 15-year mean follow-up. The purpose of the present study was to investigate polyethylene wear rates, implant survivorships, wear-related revisions, and patient-reported outcomes (PROs) in a young patient cohort who had alumina ceramic on HXPLE coupling at an average 16-year follow-up. METHODS: This was a retrospective study of 128 hips that underwent THA with HXLPE on alumina ceramic bearings between March 1, 2004, and April 15, 2007. The patient's mean age was 38 years (range, 13 to 50). All THAs utilized HXPLE liners with alumina ceramic heads. The University of California, Los Angeles activity score and modified Harris hip scores were collected preoperatively and at each follow-up. Martell hip analysis suite was used for wear calculations. RESULTS: At average 16 years (range, 13 to 18), aseptic revision survivorship was 93.3% and osteolysis/wear survivorship was 99.2%. The mean linear wear rate was 0.0191 mm/year and mean volumetric wear rate was 19.43 mm3/y, both of which were clinically undetectable. We observed excellent PROs with a significant increase in mean modified Harris hip scores (43.6 to 87.4, P < .0001) and the University of California, Los Angeles activity scores (4.0 to 6.0, P < .0001). There were no statistically significant differences in PROs or wear rates between ceramic and cobalt-chrome groups. CONCLUSION: At a mean 16-year follow-up, young patients who had HXLPE on ceramic coupling had excellent wear properties, PROs, and acceptable survivorships.

Outcomes of Periacetabular Osteotomy for Borderline Acetabular Dysplasia.

BACKGROUND: The optimal surgical treatment (hip arthroscopy compared with periacetabular osteotomy [PAO]) for borderline acetabular dysplasia (lateral center-edge angle [LCEA], 18° to 25°) remains a topic of debate. To date, the literature has focused primarily on arthroscopy outcomes, with only a few small reports on PAO outcomes. The purpose of this study was to define PAO outcomes in a large cohort of borderline hips. In a secondary analysis, we assessed the effect of prior failed arthroscopy, concurrent hip arthroscopy, and concurrent femoral osteoplasty on PAO outcomes in this cohort. METHODS: A prospective database was retrospectively reviewed for patients who underwent PAO for symptomatic instability in the setting of borderline dysplasia (LCEA, 18° to 25°). Of the 232 identified hips, 186 (80.2%) were assessed at a mean follow-up of 3.3 ± 2.0 years postoperatively. The mean patient age was 25.2 ± 8.5 years (range, 14 to 45 years), and 88.2% were female. Thirty hips (16.1%) had undergone a failed prior arthroscopy. Arthroscopy was performed concurrently with the PAO in 130 hips (69.9%), and femoral osteoplasty was performed concurrently in 120 hips (64.5%). The modified Harris hip score (mHHS) was assessed relative to the minimal clinically important difference (MCID) of 8 and patient acceptable symptom state (PASS) of 74. Clinical failure was defined as a reoperation for persistent symptoms or a failure to achieve either the mHHS MCID or PASS. RESULTS: Of the 156 hips undergoing a primary surgical procedure, clinical success was achieved in 148 hips (94.9% [95% confidence interval (CI), 90.2% to 97.4%]). Two hips (1.3% [95% CI, 0.4% to 4.6%]) underwent reoperation (hip arthroscopy) for persistent symptoms and an additional 6 hips (3.8% [95% CI, 1.8% to 8.1%]) failed to achieve the mHHS MCID or PASS, for a clinical failure rate of 5.1% (95% CI, 2.6% to 9.8%); 8.8% reported dissatisfaction with the surgical procedure. Clinical failure was more frequent among the 30 hips (23.3% [95% CI, 11.8% to 40.9%]; p = 0.001) that had undergone a prior failed arthroscopy. There were no outcome differences between hips that had or had not undergone concurrent hip arthroscopy or femoral osteoplasty. CONCLUSIONS: This study demonstrates excellent early outcomes of PAO for borderline acetabular dysplasia, with significant clinical improvement in 94.9% of patients undergoing a primary surgical procedure; 91.2% were satisfied with the surgical procedure. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Outcomes of Revision Total Hip Arthroplasty in Patients 60 Years and Younger.

Background: The annual volume of patients requiring revision total hip arthroplasty prior to age 60 is projected to increase considerably. Despite this, outcome data for revision THA in these younger patients remain limited. The purpose of this study was to define implant survivorship, identify risk factors for re-revision, and determine clinical outcomes of revision THA in patients aged ≤60 years. Methods: We identified 191 revision THAs performed in patients aged ≤60 years. Minimum 4-year follow-up was obtained in 141 (73.8%) hips (mean 10.3 years [range, 4-20]). Mean age was 48 years (range, 20-60). Forty-five hips (32%) had previously been revised. Indications for index revision included aseptic loosening (28%), polyethylene wear (26%), dislocation (20%), and infection (14%). Outcome measures were Kaplan-Meier survival free from re-revision and patient-reported outcome scores (mHHS, UCLA). Results: Survivorship free from re-revision for any cause was 78% [95% CI=70-85] at five years and 71% [62-78] at ten years. The most common indication for re-revision at both five and ten years was dislocation (12% [8-19], 16% [10-23]), followed by infection (6% [3-12], 10% [5-18]) and aseptic loosening (2% [1-7], 4% [1-11]). Mean scores were improved from baseline at six (mHHS +21.4, UCLA +0.9) and twelve years (mHHS +13.4, UCLA +0.5). Conclusion: Revision THA in patients less than 60 years of age was associated with considerably lower rates of early loosening-related failure than historically reported. Recurrent dislocation and infection appear to remain challenges in this population. Despite improvements in survivorship from earlier studies, patient-reported functional improvements remained relatively unchanged. Level of Evidence: IV.

Comparison of modern periacetabular osteotomy for hip dysplasia with total hip arthroplasty for hip osteoarthritis-10-year outcomes are comparable in young adult patients.

Young adult patients with symptomatic acetabular dysplasia and marginal secondary osteoarthritis can be faced with the decision to either undergo periacetabular osteotomy (PAO) to relieve symptoms and slow osteoarthritis progression or wait until progression to more advanced disease and undergo total hip arthroplasty (THA). The decision can be difficult, and contemporary literature to guide these decisions is sparse. Therefore, we retrospectively assessed complication rate, survivorship and patient-reported clinical outcomes [modified Harris Hip score (mHHS), UCLA Activity score] in two, consecutive cohorts of patients aged 18-40 years that underwent either PAO for symptomatic acetabular dysplasia (mean age 28.9 years) or THA for advanced secondary osteoarthritis (32.5 years). PAO patients were followed for a mean of 10.5 years (8-19) and THA patients for 11.9 (8-17) years. Between PAO and THA groups, there were no differences in overall complication rate (4.7% versus 4.7%), non-revision reoperation rate (5.9% versus 2.3%, P = 0.37) or end-revision rate [7 (8.2%) PAOs converted to THA at mean 10.8 years versus 3 (7.0%) THAs revised at 6.2 years, P = 0.80]. Latest scores remained significantly improved from baseline in both the PAO (mHHS 86.1 versus 63.3, P < 0.001; UCLA 7.5 versus 6.9, P < 0.05) and THA (mHHS 82.6 versus 48.4, P < 0.001; UCLA 7.2 versus 4.6, P < 0.001) cohorts. Final scores were similar between groups (mHHS 86.1 versus 82.6, P = 0.46; UCLA 7.5 versus 7.2, P = 0.37). Clinical success [mHHS minimal clinically important difference (8) OR PASS (>70) at latest follow-up without end-revision] was achieved in 81.2% of PAO hips and 83.7% of THA hips (P = 0.72).

Is combined surgical dislocation and proximal femoral osteotomy a safe procedure for correction of complex hip deformities?

Complex deformities of the hip requiring intra-articular and proximal femoral correction are challenging with regard to surgical access and complication risk. Combined surgical dislocation and proximal femoral osteotomy (SD/PFO) is a surgical strategy that provides unrestricted access to the joint with the capability for adjunctive PFO. Although providing excellent surgical access, concerns over a potentially high risk of postoperative complications remain, and published information on the safety of this technique remain scarce. In this study, we defined the early complication profile of combined surgery across 48 hips with a variety of complex deformities using a standardized, validated complication grading scheme for hip preservation surgery. Patients were mean age 19.1 years 13-33 years and 60% had previous surgery. At the early mean follow-up of 2.9 years, considerable improvement was seen across all outcome scores. Major complications (Grade III or higher) occurred at a rate of 4.2% (n = 2). Both were osteotomy non-unions, and both were treated successfully with revision PFO and bone grafting at mean 1.1 years. To our knowledge, the current series of combined SD-PFO surgeries represents the largest to date for which detailed complication data have been reported. Given the complexity of these disorders, a major complication rate of 4.2% is acceptable. Our complication rates were comparable to those reported for isolated SD and PFO procedures. These rates did not vary significantly across morphologic variants or patient-specific characteristics. Additionally, our complication risk profile is consistent with previous, smaller reports, which supports the generalizability of these results among appropriately experienced surgeons.

Long-Term Follow-Up of Conventional Polyethylene in Total Hip Arthroplasty in Young Patients: Heightened Wear-Related Complications Are Observed at the Beginning of the Third Decade.

BACKGROUND: Conventional polyethylene (CPE) was used widely in the past as a bearing surface in total hip arthroplasty (THA). As CPE THAs age and the revision burden continues to grow, it is increasingly important to understand the durability and failure mechanisms of this bearing material. Currently, such long-term data remain limited, particularly in younger, more active patients in whom wear issues are of greater concern. METHODS: We retrospectively reviewed 90 hips (77 patients) that underwent primary THA with CPE bearings on cobalt chrome femoral heads at age ≤50 years at 20-year minimum follow-up (mean 21.6 [20-23]). We analyzed polyethylene wear rates, clinical outcomes (modified Harris Hip Score, University of California, Los Angeles Activity Score), and implant survivorship. RESULTS: Wear analysis revealed a median linear wear rate of 0.113 mm/y (95% CI 0.102-0.148) and a median volumetric wear rate of 41.20 mm3/y (95% CI 43.5-61.0). Modified Harris Hip Scores remained 37 points above preoperative baseline (P < .001) and University of California, Los Angeles scores 1.4 points above baseline (P = .018) at 21.6-year mean follow-up. Twenty-nine hips (32.2%) were revised, 20 of which (22.2%) were wear-related at a median of 15.4 years (interquartile range 11.4-19.5). Survivorship free from wear-related revision was 95.6% (95% CI 88.7-98.3), 87.9% (78.6-93.3), 78.1% (49.6-66.5), and 61.1% (41.3-67.0) at 10, 15, 20, and 25 years. CONCLUSION: Wear-related issues developed at increasingly high rates after 15 years, suggesting the need for surveillance after this time. The long-term wear and survivorship data of this study may be used as a benchmark when evaluating the performance of contemporary bearings in young, active THA patients.

Total Hip Arthroplasty in Patients With Osteoarthritis Associated With Legg-Calve-Perthes Disease: Perioperative Complications and Patient-Reported Outcomes.

BACKGROUND: Complications and patient-reported outcomes (PROs) of total hip arthroplasty (THA) in patients with Legg-Calve-Perthes disease (LCPD) have demonstrated variable results. The purpose of this study was to use a validated grading scheme to analyze complications associated with THA in patients with residual LCPD deformities. Second, we report PROs and intermediate-term survivorship in this patient population. METHODS: A retrospective, single-center review was performed on 61 hips in 61 patients who underwent THA for residual Perthes disease. Average patient age was 42 years and 26% of hips had previous surgery. Complications were determined and categorized using a validated grading scheme that included five grades based on the treatment required to manage the complication and on persistent disability. PROs were compared from preoperative to most recent follow-up time points. RESULTS: Major complications (grade III) occurred in three patients (5%) which each required a second surgical intervention. The most common minor grade I or II complications (11.5%) were asymptomatic heterotopic ossification (3.3%). Patients were lengthened on the surgical side an average of 1.4 cm with no nerve palsies. All patient PROs improved from preoperative to postoperative time points with the modified Harris Hip Score improving from 46.9 preoperatively to 85.4 postoperatively (P < .01). Patients free from revision for any reason at final follow-up (5.6 years; range 2-13 years) was 98.4% with one patient needing a revision of their femoral component. CONCLUSIONS: THA for the sequelae of the LCPD has an acceptable complication rate and provides excellent patient reported outcomes at mid-term follow-up.

Incidence and Characteristics of Osteolysis in HXLPE THA at 16-Year Follow up in Patients 50 Years and Less.

INTRODUCTION: Young patients present a challenge for total hip arthroplasty (THA) survivorship. Highly cross-linked polyethylene (HXLPE) liners have decreased the prevalence of osteolysis; however, concerns exist regarding the biologic activity of wear particles. The purpose of this study was to determine the incidence and characteristics of osteolytic lesions in young HXLPE THA patients at an average 16-year follow up and determine the ability to detect osteolysis. METHODS: We performed a retrospective study involving 22 patients (26 THA) under age 50 at primary THA receiving HXLPE liners coupled with cobalt-chrome (CoCr) femoral heads. Computed tomography (CT) scans were reviewed for osteolysis. Chi-squared analysis was used for categorical variables and unpaired Kruskal-Wallis rank-sum test for continuous variables. Logistic regression was used to compare wear rates between those patients with and without osteolysis. RESULTS: The mean age at surgery was 38.5 years. The mean time from surgery to CT scan was sixteen years (range 14.25-19.5 years). Nine of the 26 THA showed osteolysis. The mean volume of the lesions was 2.8 cm3. Linear (mean 0.008 mm/y) and volumetric (mean 4.5 mm3/year) wear rates were negligible. One-third of osteolytic lesions were visible on radiographs. Logistic regression failed to demonstrate a correlation between wear rates or UCLA activity score and osteolysis. CONCLUSION: We observed osteolysis in 35% of HXLPE THA in young patients at mean 16-year follow up despite zero revisions for wear-related problems and clinically insignificant wear rates. LEVEL OF EVIDENCE: IV.

Severe Hip Dysplasia in Skeletally Mature Patients With Spastic Cerebral Palsy: The Technique and Early Outcome of Comprehensive Surgical Correction (Including the Bernese PAO).

BACKGROUND: Treatment of symptomatic hip dysplasia in skeletally mature patients with spastic cerebral palsy (CP) can be challenging. This study examines our technical experience with the Bernese periacetabular osteotomy (PAO) in combination with adjunctive procedures in the treatment of this complex hip deformity. METHODS: Sixteen consecutive patients (18 hips) with symptomatic CP hip dysplasia were treated with a PAO and variable adjunctive procedures and retrospectively reviewed. Two patient (2 hips) were excluded due to insufficient follow-up. The average age at the time of surgery was 17.7 years (range: 13 to 28 y). We compared the preoperative to postoperative changes in radiographic parameters as well as early outcomes as measured by patient assessment of hip pain and function using the modified Harris Hip Score (mHHS). RESULTS: The average time of follow-up was 3.3 years (range: 2.0 to 6.3 y). Tönnis angles decreased from a median of 30 degrees (range: 18 to 45 degrees) preoperatively to a median of 6 degrees (range: -9 to 21 degrees) postoperatively. Lateral center-edge angles increased from a median of -8 degrees (range: -28 to 15 degrees) to a median of 32 degrees (range: 19 to 38 degrees). Anterior center-edge angles increased from a median of 2 degrees (range: -22 to 39 degrees) to a median of 35 degrees (range: 22 to 47 degrees). The extrusion index decreased from a median of 57% preoperatively (range: 35% to 73%) to a median of 21% (range: 11% to 36%) postoperatively.The median mHHS was 62 (range: 37 to 81) preoperatively and 85 (range: 65 to 100) postoperatively. Notably, the pain component of the mHHS improved from 20 (range: 0 to 44) to 42 (range: 30 to 44). Tönnis osteoarthritis grade preoperatively was either 0 (11 hips) or 1 (5 hips) and remained unchanged in 11 hips and increased by 1 grade in 5 hips. CONCLUSIONS: It has been our experience that the Bernese PAO in combination with appropriate adjunctive treatments has provided a very satisfactory surgical approach in the treatment of CP hip dysplasia. In the adolescent and young adult with spastic CP, utilizing the Bernese PAO technique makes it possible to obtain redirection of often a very severe acetabular dysplasia. Adjunctive soft tissue procedures and a proximal femoral osteotomy are frequently necessary to maintain postoperative stability. A notable improvement in the quality of life and function directly attributable to our surgical treatment of their pre-existing problematic hip dysplasia has been consistently noted in early follow-up for our patients. LEVEL OF EVIDENCE: Level IV-therapeutic.

Fifteen-Year Results of Total Hip Arthroplasty With Cobalt-Chromium Femoral Heads on Highly Cross-Linked Polyethylene in Patients 50 Years and Less.

BACKGROUND: Highly cross-linked polyethylene (HXLPE) is the most commonly used bearing surface in total hip arthroplasty (THA) because of its superior wear properties, but long-term results in young patients are limited. Mid-term survivorship has been promising; however, polyethylene wear rates and need for revision surgeries remain a concern in this population. The purpose of our study is to investigate polyethylene wear rates, implant survivorship, wear-related revisions, and patient-reported outcomes in a young patient cohort at 15-year follow-up. METHODS: We performed a retrospective study of a prospective longitudinal cohort of 82 consecutive patients (89 hips) who underwent primary THA with an HXLPE acetabular liner and a cobalt-chromium femoral head. The mean age at the time of surgery for the cohort was 38.8 years (range 12-50). All patients received HXLPE liners with a cementless acetabular component coupled with a cobalt-chrome femoral head through a posterior approach with a cementless femoral component. All components were from a single manufacturer. We recorded University of California, Los Angeles Activity, and modified Harris Hip Scores. Wear calculations were made using the Martell Hip Analysis Suite (Version 8.0.4.3). RESULTS: At average 15 years (range 13.1-18.5), there was a revision-free survivorship of 97.8% in our HXLPE group with no wear-related revisions. We observed a linear wear rate of 0.0185 mm/y (standard deviation 0.05) after accounting for a 1-year bedding-in period. The volumetric wear rate was found to be 12.80 mm3/y (standard deviation 22.69). These numbers are registered as clinically undetectable and are comparable to steady state wear rates in the same cohort of patients at earlier time points. We found no radiographic changes concerning osteolysis. We observed excellent patient-reported outcomes at this time point with improvements in modified Harris Hip Scores (35.3 [22.5], P < .0001) and University of California, Los Angeles Activity Scores (median 6.0, P < .0001). CONCLUSION: At 15-year follow-up, we demonstrated that HXLPE bearings in this young cohort had excellent wear properties, maintained superior clinical improvements, and underwent no wear-related revision operations. The HXLPE and cobalt-chrome bearing couple continues to be extremely effective 15 years after primary THA in patients less than 50 years. LEVEL OF EVIDENCE: IV.

Conventional Polyethylene in Total Hip Arthroplasty in Young Patients: Survivorship, Wear Analysis, and Clinical Outcomes Between 15 and 20 Years.

BACKGROUND: Total hip arthroplasty (THA) remains a successful procedure for most patients. However, there is a paucity of information regarding the long-term performance of conventional polyethylene (CPE) bearings in young patients undergoing THA. METHODS: After accounting for incomplete follow-up of a prospective cohort of 123 THAs in patients ≤50 years, we performed a retrospective review of 101 hips in 84 patients (82.1%) with an average 17.1-year follow-up (14.7-19.6 years). Outcomes of interest included linear and volumetric wear, clinical outcome scores, implant survivorship, and patient mortality. Wear rates were calculated using Martell Software. RESULTS: Wear analysis revealed median linear and volumetric wear rates of 0.106 mm/y (confidence interval, 0.079-0.133) and 43.58 mm3/y (confidence interval, 33.4-53.75). The modified Harris hip scores improved by 36 points while University of California, Los Angeles activity scores improved by 2.0 points at 15-year follow-up (P < .0001). Twenty-two hips (21.8%) were revised, 13 of which (12.8%) were for wear-related causes at an average of 14.9 years (range, 9.2-21 years) from index arthroplasty. There was significantly higher mortality in patients with a preoperative diagnosis of inflammatory avascular necrosis (P = .015). CONCLUSION: Because CPE was commonly used in THA over the last 25 years, it is important to understand its implications on the growing revision burden. Significant concerns exist with regard to the long-term durability of CPE bearings in young, moderately active patients 15 years after THA. These patients should be followed closely for wear-related problems. Our results should be used as a comparison when evaluating the outcomes of more modern bearing surface combinations.