Total Hip Arthroplasty After Peri-Acetabular Osteotomy Results in Significant Improvement in Hip Function With Low Revision Rates at Mid-Term Follow-Up.

Background: Bernese periacetabular osteotomy (PAO) improves symptoms and delays degenerative changes in patients with acetabular dysplasia. Yet, eventual total hip arthroplasty (THA) is needed in many of these patients. The impact of PAO on subsequent THA outcomes is not well defined. The purpose of this study is to define: 1) clinical outcomes, 2) post-operative complications and 3) implant survivorship for patients undergoing THA after prior ipsilateral PAO. Methods: A retrospective review was conducted at three institutions to identify individuals undergoing THA after ipsilateral PAO surgery with minimum 1 year follow up. Patient reported outcome measures (PROMs) were collected preoperatively and at final follow-up. Surgical details, radiographic and clinical outcomes, and major complications according to the modified Dindo-Clavien classification system were identified through review of the medical record. Regression analysis and student's t-test were used to compare pre- and post-operative outcome scores. Kaplan-Meier analysis was performed to estimate reoperation-free survivorship. Results: A total of 113 THA in 112 patients were identified with initial review. 103 hips had a minimum of 1-year follow-up and an average follow of 5 ± 4 years (range, 1 to 20). 10 hips (9%) were lost to follow-up leaving 103 (91%) hips available for review with a minimum of 1-year follow-up (mean = 5 years). Mean interval from PAO to THA was 7.7 years (range, 2-15). The average post-operative mHHS improved 37 points (50 to 87, P < 0.001) when compared to pre-operative scores. Eight patients (7.1%) experienced a major grades III-V) surgical complication. These included 2 cases of instability, 2 cases of acetabular loosening, and one case each of periprosthetic fracture, wound dehiscence, periprosthetic infection, acetabular loosening and pneumonia. Failures occurred early at average 3.2 years and survivorship analysis for all-cause revision demonstrated 96% survivorship at both 5 and 10 years. Conclusion: THA after PAO achieves significant clinical improvement and satisfactory survivorship (96%) at mid-term follow-up, with a major complication rate of 7.1%. Level of Evidence: III.

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.

Combined Surgical Dislocation and Periacetabular Osteotomy for Complex Residual Legg-Calvé-Perthes Deformities: Intermediate-Term Outcomes.

BACKGROUND: Residual Legg-Calvé-Perthes (LCP) deformities represent one of the most challenging disorders in hip reconstructive surgery. In complex cases, both instability (acetabular dysplasia) and multifocal femoroacetabular impingement (FAI) (proximal femoral deformities) require correction. We assessed intermediate-term patient-reported outcome measures, radiographic correction, complications, and survivorship for combined surgical dislocation (SD) and periacetabular osteotomy (PAO) for the treatment of complex LCP deformities. METHODS: A retrospective cohort study was performed on 31 hips with complex LCP deformities undergoing combined SD and PAO for concurrent instability and FAI. Treatment included femoral head reshaping, trochanteric advancement and relative femoral neck lengthening, management of intra-articular lesions, and PAO. Twenty-seven hips (87%) had a minimum follow-up of 5 years. The mean age was 19.8 years, 56% of patients were female, and 44% of patients had undergone a previous surgical procedure. RESULTS: At a mean of 8.4 years, 85% of hips (23 of 27) remained preserved (no conversion to total hip arthroplasty). The survivorship estimates were 93% at 5 years and 85% at 10 years. The median (and interquartile range) increased from 64 points (55, 67 points) to 92 points (70, 97 points) (p < 0.001) for the modified Harris hip score (mHHS) and from 60 points (45, 75 points) to 86 points (75, 100 points) (p = 0.001) for the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score. Symptoms (mHHS < 70 points) were reported for an additional 19% of hips (n = 5) at the final follow-up. The University of California Los Angeles (UCLA) activity score increased from a median of 8 points (6, 10 points) to 9 points (7, 10 points) (p = 0.207). Structural correction included mean improvement (and standard deviation) of 15.3° ± 7.6° for acetabular inclination, 20.7° ± 10.8° for the lateral center-edge angle, 23.4° ± 16.3° for the anterior center-edge angle, and 18 ± 10 mm for trochanteric height (p < 0.001 for all). Complications occurred in 2 hips (7%), including 1 deep wound infection and 1 superficial wound infection. There was 1 reoperation due to complication, but there were no nerve palsies, thromboembolic events, fractures, or nonunions. CONCLUSIONS: At an intermediate follow-up of combined SD and PAO for complex LCP deformities, 85% of hips were preserved. This procedure provides reliable deformity correction, major pain relief, improved function, and acceptable complication and failure rates. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Telemedicine for Hip Preservation Patients: Access, Ability and Preference.

Background: Recent events have resulted in rapid rises in the use of telemedicine in orthopaedic surgery, despite limited evidence regarding patient preferences or concerns. The purpose of this study is to determine access to and, ability to use telemedicine technology in an adult hip preservation patient population, as well as determine associations with patient characteristics. Additionally, we seek to understand patients' perceived benefits, risks and preferences of telemedicine. Methods: We performed a cross-sectional survey administered on patients scheduled to undergo joint preservation surgery by one of three surgeons at a single academic institution. Both preoperative and postoperative established patients were included and called for a telephone administered survey if a date of surgery was scheduled between October 1, 2019 and March 30, 2020 and were 18 years or older. The survey had seven sections with 45 questions relating to demographics, technology access, videoconferencing capability, confidence using technology, telehealth experiences, perceptions. Results: 101 patients completed the survey (48% response rate, 101/212). Overall, 99% of participants reported using the internet, 94% reporting owning a device capable of videoconferencing, and 86% of patients had participated in a video call in the past year. When asked for their preferred method for a physician visit: 79% ranked in-person as their first choice and 16% ranked a videoconference visit as their first choice. Perceived benefits of telemedicine visits included reduced travel to appointments (97% agree) and reduced cost of attending appointments (69% agree). However, patients were concerned that they would not establish the same patient-physician connection (51% agree) and would not receive the same level of care (38% agree) through telemedicine visits versus in person visits. Conclusion: The majority of hip preservation patients have access to and are capable of using the technology required for telemedicine visits. However, patients still prefer to have in person visits over concerns that they will not establish the same patient-physician connection and will not receive the same level of care. Telemedicine visits in hip preservation patients may be most attractive to return patients with an established doctor-patient relationship, particularly those with concerns for long distances of travel and associated costs.Level of Evidence: III.

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.

Complications associated with combined surgical hip dislocation and periacetabular osteotomy for complex hip deformities.

Surgical hip dislocation (SD) and periacetabular osteotomy (PAO) are well-described treatments for femoroacetabular impingement (FAI) and acetabular dysplasia, respectively. Occasionally, complex deformities require a combined SD/PAO; the morbidity of performing both procedures in a single stage has not been fully investigated. We performed a retrospective review of a consecutive group of patients undergoing combined SD/PAO to investigate the incidence and character of perioperative complications. Forty-five patients (46 hips) were identified. Perioperative complications were graded by the modified Clindo-Davien complication scheme. Mean follow-up was 36 months (range 12-128), and no patients were lost to follow-up. Six complications occurred in six hips (13%). Four (8.7%) complications were minor (Grades I or II): one Brooker Grade III heterotopic ossification requiring no treatment, one superior pubic ramus nonunion requiring no treatment and two superficial wound infections requiring antibiotics. Two (4.3%) complications were major (Grades III or IV): one coxa saltans interna and labral tear requiring hip arthroscopy with labral repair and iliopsoas lengthening, and one deep surgical site infection requiring irrigation and debridement followed by development of arthritis requiring conversion to arthroplasty. The average Harris hip score improved from 62 ± 13 preoperatively to 80 ± 19 at final follow-up. Except for the single joint replacement, there were no long-term disabilities. There were no major neurovascular injuries, osteonecrosis, fractures or trochanteric nonunions. Combined SD/PAO for the treatment of complex, concomitant deformities of the proximal femur and acetabulum is associated with an acceptable risk of complications. The vast majority of complications that occurred were managed without permanent disability. Level of Evidence: IV.

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.

A Prospective Analysis of the Contralateral Hip Among Patients With Femoroacetabular Impingement: What Are the Risk Factors for Disease Progression?

BACKGROUND: The pathophysiology of femoroacetabular impingement (FAI) remains to be better understood, including factors affecting symptom development and disease progression. PURPOSE: (1) To determine rates of initial and subsequent symptom development in the contralateral hip of patients with symptomatic FAI and (2) to identify predictors of the development of symptomatic contralateral FAI. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: This prospective study cohort included the contralateral hip of 179 consecutive patients undergoing primary surgical treatment of FAI. At presentation and follow-up time points, patients recorded the presence of symptoms in the contralateral hip. Patients with a minimum 1-year follow-up were included in the final cohort. Univariate analysis compared the patient characteristics and FAI imaging characteristics (cam and pincer) of initially asymptomatic patients who developed symptoms and those who remained asymptomatic. Kaplan-Meier survival curves were calculated to demonstrate symptom development over time. RESULTS: A total of 148 patients (83%) were followed for at least 1 year (mean, 2.9 years). Thirty-four (23%) patients had symptoms in the contralateral hip at the time of the initial presentation. An additional 27 hips (24% of the initially asymptomatic) developed symptoms during the follow-up period at a mean 2.0 years from presentation. Head-neck offset ratio on the anteroposterior pelvis radiograph was significantly lower among hips that developed symptoms (0.153 vs 0.163 asymptomatic group, P = .027). Maximum alpha angle ( P = .503), lateral center edge angle ( P = .975), and crossover sign ( P = .865) were not predictive of the development of symptoms. Patients developing contralateral hip symptoms were less likely to have a UCLA (University of California, Los Angeles) activity score of 9 or 10 at presentation (18.2% vs 43.8%, P = .032). The total arc of rotation in flexion (internal rotation in 90° of flexion + external rotation in flexion) was significantly decreased in hips developing symptoms (39.4º vs 50.4º, P = .012). Kaplan-Meier survival analysis demonstrated that 72%, 67%, 56%, and 48% of all patients remained asymptomatic at 1, 2, 3, and 4 years, respectively. CONCLUSION: Approximately 1 in 4 patients with FAI presents with symptoms in the contralateral hip, and an additional 1 in 4 patients develops significant symptoms in the following 4 years. Several factors, including low activity level, less hip rotational motion, and decreased head-neck offset ratio, were significantly associated with the development of symptoms, while the alpha angle and crossover sign were not.

Do Radiographic Parameters of Dysplasia Improve to Normal Ranges After Bernese Periacetabular Osteotomy?

BACKGROUND: The goal of periacetabular osteotomy (PAO) is to improve the insufficient coverage of the femoral head and achieve joint stability without creating secondary femoroacetabular impingement. However, the complex tridimensional morphology of the dysplastic acetabulum presents a challenge to restoration of normal radiographic parameters. Accurate acetabular correction is important to achieve long-term function and pain improvement. There are limited data about the proportion of patients who have normal radiographic parameters restored after PAO and the factors associated with under- and overcorrection. QUESTIONS/PURPOSES: (1) What is the proportion of patients undergoing PAO in which the acetabular correction as assessed by the lateral center-edge angle (LCEA), anterior center-edge angle (ACEA), acetabular inclination (AI), and extrusion index (EI) is within defined target ranges? (2) What patient and preoperative factors are associated with undercorrection of the acetabulum as defined by a LCEA < 22°, a factor that has been reported to be associated with PAO failure at 10-year followup? METHODS: Between January 2007 and December 2011 we performed 132 PAOs in 116 patients for treatment of symptomatic acetabular dysplasia. One patient with Legg-Calvé-Perthes disease, one with multiple osteochondromatosis, and two with concomitant femoral osteotomy were excluded. A total of 128 hips (112 patients) were included. The hip cohort was 76% (97 of 128) female and the mean age at surgery was 28.5 years (SD 8.7 years). Correction of LCEA between 25° and 40°, ACEA between 18° and 38°, Tönnis angle between 0° and 10°, and EI ≤ 20% were defined as adequate based on normative values. Values lower than the established parameters were considered undercorrection for the LCEA and ACEA and those higher than the established values were considered overcorrection. Because postoperative LCEA < 22o has been previously associated with PAO failure at a minimum of 10-year followup, in this study we sought to measure whether demographic factors including age, gender, body mass index, and severity of acetabular dysplasia assessed by preoperative LCEA, ACEA, AI, and EI were associated with undercorrection. Postoperative radiographs were obtained at minimum of 1 month after surgery (mean, 7 months; range, 1-44 months) and were measured by a professional research assistant and a hip reconstruction fellow not involved in the clinical care of the patients. No patient was lost to followup. RESULTS: Of the 128 hips, the proportion of hips with radiographic parameters within the established range was 78% (100 hips) for the LCEA, 86% (110 hips) for the ACEA, 89% (114 hips) for the AI, and 80% (102 hips) for the EI. For hips with an inadequate correction, the LCEA was more often undercorrected than overcorrected (20% versus 2%; 95% confidence interval [CI], 11%-27%; p < 0.001), whereas the ACEA was more often overcorrected than undercorrected (11% versus 3%; 95% CI, 1%-15%; p = 0.03) After adjusting for age, sex, body mass index, and preoperative radiographic parameters including ACEA, AI, and EI, we found that the preoperative LCEA was the only independent factor associated with a postoperative LCEA < 22° (odds ratio, 0.92; 95% CI, 0.87-0.97; p = 0.003), indicating that hips with lower preoperative LCEA were more likely to have a LCEA < 22°. For each additional degree of preoperative LCEA, the odds of LCEA < 22° were reduced by 15%. CONCLUSIONS: Acetabular correction after PAO performed by two experienced surgeons was adequate for individual radiographic parameters in most but not all hips. Hips with more severe dysplasia preoperatively are at higher risk for undercorrection as assessed by the LCEA. This intuitive information may help surgeons performing PAO in severely dysplastic hips plan for possible combined procedures including a femoral osteotomy if PAO alone does not allow for adequate correction of femoral head coverage and a congruous concentric hip. Further studies are planned to determine whether the long-term hip function and pain in patients whose hips were corrected within these established parameters will be improved in comparison to those that were under- or overcorrected. LEVEL OF EVIDENCE: Level III, therapeutic study.

Gender Differences in Wear Rates for 28- vs 32-mm Ceramic Femoral Heads on Modern Highly Cross-linked Polyethylene at Midterm Follow-Up in Young Patients Undergoing Total Hip Arthroplasty.

BACKGROUND: We report on the midterm linear and volumetric wear of highly cross-linked polyethylene (HXLPE) and survivorship of 2 prospective young total hip arthroplasty (THA) cohorts that differed by the size of ceramic femoral head used: 28 vs 32 mm. METHODS: We prospectively analyzed 220 consecutive primary THAs in patients aged ≤50 years who received a cementless THA with a ceramic femoral head on HXLPE liner (C-HXLPE). There were 101 patients (46%) with 28-mm heads and 119 patients (54%) who received 32-mm heads at a mean follow-up of 5.5 years (range, 60-109 months). Wear was calculated using Martell Software. RESULTS: The 28-mm C-HXLPE cohort demonstrated average linear and volumetric wear of 0.020 mm/y (standard deviation [SD], 0.074; 95% CI, 0.003-0.037) and 18.775 mm(3)/y (SD, 21.743; 95% CI, 13.773-23.778) compared with 0.032 mm/y (SD, 0.087; 95% CI, 0.013-0.050]) and 29.847 mm(3)/y (SD, 35.441; 95% CI, 22.294-37.401) in the 32-mm C-HXLPE group. Subgroup analysis by gender and head size discovered significantly greater wear in females with 32-mm heads compared with 28-mm heads in both linear (0.01, 95% CI = -0.014 to 0.033 vs 0.048, 95% CI = 0.022-0.074 mm/y, P = .004) and volumetric wear (14.11, 95% CI = 8.957-19.271] vs 29.71, 95% CI = 17.584-41.840] mm(3)/y, P = .009). We found a 96% (95% CI = 92.30%-97.94%]) survivorship by Kaplan-Meier analysis at minimum 5 years with no failures because of osteolysis. CONCLUSIONS: Ceramic on HXLPE demonstrates extremely low wear properties in young patients at midterm follow-up. We identified a gender-dependent difference in wear based on head size, with 32-mm heads being associated with increased wear in females.