The Efficacy of Tranexamic Acid in Total Hip Arthroplasty: A Network Meta-analysis.

BACKGROUND: Tranexamic acid (TXA) is an antifibrinolytic agent commonly used to reduce blood loss in total hip arthroplasty (THA). The purpose of our study was to evaluate the efficacy of TXA in primary THA to support the combined clinical practice guidelines of the American Association of Hip and Knee Surgeons, American Academy of Orthopaedic Surgeons, Hip Society, Knee Society, and American Society of Regional Anesthesia and Pain Medicine on the use of TXA in primary total joint arthroplasty. METHODS: A search was performed using Ovid-MEDLINE, Embase, Cochrane Reviews, Scopus, and Web of Science databases to identify all publications before July 2017 on TXA in primary THA. We completed qualitative and quantitative homogeneity testing of all included studies. Direct and indirect comparisons were analyzed using a network meta-analysis followed by consistency testing of the results. RESULTS: Two thousand one hundred thirteen publications underwent critical appraisal with 34 publications identified as representing the best available evidence for inclusion in the analysis. Topical, intravenous, and oral TXA formulations provided reduced blood loss and risk of transfusion compared to placebo, but no formulation was clearly superior. Use of repeat doses, higher doses, or variation in timing of administration did not significantly reduce blood loss or risk of transfusion. CONCLUSIONS: Strong evidence supports the use of TXA to reduce blood loss and risk of transfusion after primary THA. No specific routes of administration, dosage, dosing regimen, or time of administration provides clearly superior blood-sparing properties.

The Efficacy of Tranexamic Acid in Total Knee Arthroplasty: A Network Meta-Analysis.

BACKGROUND: A growing body of published research on tranexamic acid (TXA) suggests that it is effective in reducing blood loss and the risk for transfusion in total knee arthroplasty (TKA). The purpose of this network meta-analysis was to evaluate TXA in primary TKA as the basis for the efficacy recommendations of the combined clinical practice guidelines of the American Association of Hip and Knee Surgeons, American Academy of Orthopaedic Surgeons, Hip Society, Knee Society, and American Society of Regional Anesthesia and Pain Medicine on the use of TXA in primary total joint arthroplasty. METHODS: We searched Ovid MEDLINE, Embase, Cochrane Reviews, Scopus, and Web of Science databases for publications before July 2017 on TXA in primary total joint arthroplasty. All included studies underwent qualitative and quantitative homogeneity testing. Direct and indirect comparisons were performed as a network meta-analysis, and results were tested for consistency. RESULTS: After critical appraisal of the available 2113 publications, 67 articles were identified as representing the best available evidence. Topical, intravenous (IV), and oral TXA formulations were all superior to placebo in terms of decreasing blood loss and risk of transfusion, while no formulation was clearly superior. Use of repeat IV and oral TXA dosing and higher doses of IV and topical TXA did not significantly reduce blood loss or risk of transfusion. Preincision administration of IV TXA had inconsistent findings with a reduced risk of transfusion but no effect on volume of blood loss. CONCLUSIONS: Strong evidence supports the efficacy of TXA to decrease blood loss and the risk of transfusion after primary TKA. No TXA formulation, dosage, or number of doses provided clearly improved blood-sparing properties for TKA. Moderate evidence supports preincision administration of IV TXA to improve efficacy.

The Safety of Tranexamic Acid in Total Joint Arthroplasty: A Direct Meta-Analysis.

BACKGROUND: Tranexamic acid (TXA) is effective in reducing blood loss in total joint arthroplasty (TJA), but concerns still remain regarding the drug's safety. The purpose of this direct meta-analysis was to evaluate and establish a basis for the safety recommendations of the combined clinical practice guidelines on the use of TXA in primary TJA. METHODS: A search was completed for studies published before July 2017 on TXA in primary TJA. We performed qualitative and quantitative homogeneity testing and a direct comparison meta-analysis. We used the American Society of Anesthesiologists (ASA) score of 3 or greater as a proxy for patients at higher risk for complications in general and performed a meta-regression analysis to investigate the influence of comorbidity burden on the risk of arterial thromboembolic event and venous thromboembolic event (VTE). RESULTS: Topical, intravenous, and oral TXA were not associated with an increased risk of VTE after TJA. In addition, meta-regression demonstrated that TXA use in patients with an ASA status of 3 or greater was not associated with an increased risk of VTE after total knee arthroplasty. CONCLUSION: Although most studies included in our analysis excluded patients with a history of prior thromboembolic events, our findings support the lack of evidence of harm from TXA administration in patients undergoing TJA. Moderate evidence supports the safety of TXA in patients undergoing total knee arthroplasty with an ASA score of 3 or greater. The benefits of using TXA appear to outweigh the potential risks of thromboembolic events even in patients with a higher comorbidity.

Liposomal bupivacaine in total hip arthroplasty: Do the results justify the cost?

INTRODUCTION: Liposomal bupivacaine has a paucity of data regarding narcotic requirements and hospital length of stay in comparison to other peri-articular injections, specifically in the total hip arthroplasty (THA) population. METHODS: 69 patients who underwent THA by a single surgeon were divided into two cohorts over a 3 year period in this retrospective study comparing narcotic requirements, hospital length of stay and cost. The study group (n = 29) received liposomal bupivacaine whereas a matched control group (n = 40) received a pharmacy-mixed cocktail in peri-articular structures. Statistical and clinical differences were reported in this unfunded study. RESULTS: No difference was found in hospital length of stay [2.9 days in the study group (range 1-14) versus 3.1 days (range 1-11) in the control group, p = 0.101], however, the study group required less narcotics per day [22.6 mg (range 5-53.3) versus 29 mg (range 6.7-80.8) in the control group, p = 0.045]. The clinical difference between cohorts averaged less than one pill per day of hospitalization. The cost per patient of the local injection was more than 11 times greater in the liposomal bupivacaine group. CONCLUSION: Liposomal bupivacaine demonstrated a statistical improvement in narcotic requirements but not in hospital length of stay in comparison to a control group. The effects of liposomal bupivacaine on narcotic requirements and hospital length of stay may not justify its use in total hip arthroplasty patients given the substantial cost of these injections and the minimal clinical difference in outcomes compared to a more cost-effective injection.

Economic Impact of Ketorolac vs Corticosteroid Intra-Articular Knee Injections for Osteoarthritis: A Randomized, Double-Blind, Prospective Study.

BACKGROUND: Knee osteoarthritis is a disabling disease that costs billions of dollars to treat. Corticosteroid gives varying pain relief and costs $12 per injection, whereas ketorolac costs $2 per injection, per institutional costs. The aim of this study was to compare ketorolac with corticosteroid based on pain relief using patient outcome measures and cost data. METHODS: A total of 35 patients were randomized to ketorolac or corticosteroid intra-articular knee injection in a double-blind, prospective study. Follow-up was 24 weeks. Osteoarthritis was evaluated using Kellgren-Lawrence grading. Visual analog scale (VAS) was the primary outcome measure. A query of the institutional database was performed for International Classification of Diseases, Ninth Revision codes 715.16 and 719.46, and procedure code 20610 over a 3-year period. Two-way, repeated measures analysis of variance and Spearman rank correlation were used for statistical analysis. RESULTS: Mean VAS for ketorolac and corticosteroid decreased significantly from baseline at 2 weeks, 6.3-4.6 and 5.2-3.6, respectively and remained decreased for 24 weeks. There was no correlation between VAS and demographics within treatments. There were 220, 602, and 405 injections performed on patients with the International Classification of Diseases, Ninth Revision codes 715.16 and 719.46 during 2013, 2014, and 2015, respectively. The cost savings per year using ketorolac instead of corticosteroid would be $2259.40, $6182.54, and $4159.35 for 2013, 2014, and 2015, respectively, with a total savings of $12,601.29 over this period. CONCLUSION: Pain relief was similar between ketorolac and corticosteroid injections. Ketorolac knee injection is safe and effective with a cost savings percentage difference of 143% when compared with corticosteroid.

Can Sequentially-irradiated and Annealed Highly Cross-linked Polyethylene Inserts Thinner than Eight-millimeters Be Utilized in Total Knee Arthroplasty?

The routine use of highly cross-linked ultra-high molecular weight polyethylene (UHMWPE) has remained controversial secondary to the possibility of decreased material properties when compared to conventional UHMWPE. The aim of the present study was to evaluate if thin, sequentially-irradiated, and annealed highly cross-linked UHMWPE tibial inserts would have improved wear properties, while maintaining mechanical integrity, compared to conventional UHMWPE during biomechanical testing under aligned and malaligned conditions. Polyethylene inserts (4.27 and 6.27 mm) manufactured from GUR 1020-UHMWPE were cyclically loaded to analyze for wear. All wear scars were visually examined after loading using scanning electron microscopy (SEM). Volume loss was plotted versus cycle count with linear regression analysis yielding wear rates. There was no statistical difference in wear between both thicknesses for all testing conditions. During aligned condition testing, the volumetric wear rate for sequentially-irradiated and annealed polyethylene thicknesses of 4.27 and 6.27 mm was 4.0 and 4.4 mm3/million cycles; and during malaligned conditions, it was 13.9 and 15.1 mm3/million cycles. For conventional polyethylene during aligned conditions, the volumetric wear rate was 33.0 and 22.8 mm3/million cycles; and during malaligned conditions it was 50.0 and 50.8 mm3/million cycles. By SEM evaluation, condylar wear surfaces for conventional and sequentially-irradiated and annealed polyethylene displayed surface ripples typical of adhesive wear. There were no observed visible differences between the wear scars for conventional compared to sequentially-irradiated and annealed polyethylene with no evidence of fatigue failure. This study demonstrated no differences between polyethylenes with thicknesses of 4.27 and 6.27 mm. This strengthens the conclusion that sequentially-irradiated and annealed highly cross-linked UHMWPE can be utilized in total knee arthroplasty. The successful wear properties of 4.27 mm liners could mean that smaller tibial resections leading to bone stock preservation could be utilized in patients undergoing total knee arthroplasty, although further in-vivo studies are needed.

Patellar fractures following total knee arthroplasty: a review.

There are several periprosthetic complications associated with total knee arthroplasty, with femoral fracture as the most common and patellar fractures as the second most common. Patellar fractures are challenging complications that occur almost exclusively on the resurfaced patellae, although unresurfaced patellar fractures have been reported in literature. The purpose of this study is to describe the anatomy of the patella, the etiology of patellar fractures, and strategies to treat and manage these fractures following knee arthroplasty. The vascular supply to the patella may be compromised during total knee arthroplasty and special care must be taken to preserve it. Vessel injury may result in further complications, most notably avascular necrosis with subsequent fracture. Other patient-, surgical-, and prosthetic-related factors can contribute to increased risk of patellar fracture. Patellar fractures are classified into three types. Type I fractures have an intact extensor mechanism with a stable implant. Type II fractures have a complete disruption of the extensor mechanism with or without a stable implant. Type III fractures, which are further subclassified into types IIIa and IIIb, have an intact extensor mechanism but a loose patellar component. While type IIIa fractures have reasonable remaining bone stock, type IIIb fractures have poor bone stock. Type I patellar fractures may be best managed nonoperatively, but types II and III patellar fractures often necessitate surgical intervention. Patellectomy should be reserved for comminuted fractures, as well as fractures in patients with poor bone stock. Larger prospective randomized studies are necessary to better evaluate the treatment algorithm for patellar fractures following total knee arthroplasty.

Total knee arthroplasty in patients 40 years and younger.

Total knee arthroplasty (TKA) is a procedure with excellent clinical results in older patients with a primary diagnosis of osteoarthritis. Many younger patients undergo unicompartmental or high tibial osteotomy rather than TKA, but are not always good candidates for these joint-preserving procedures. The purpose of this study was to review the outcomes of patients 40 years of age and under who underwent TKA. We identified 33 patients (38 knees) who were 40 years of age or less at the time of surgery. These patients had a mean age of 36 years (range, 23 to 40 years), and were followed for a mean of 49 months (range, 16 to 101 months). The survival rate in the study cohort was 97%. For the young patient who is not a candidate for other types of joint preserving procedures, in the senior authors' experience total knee arthroplasties have performed well.

Incidence of contralateral THA after index THA for osteoarthritis.

BACKGROUND: Currently more than 200,000 THAs are performed annually in the United States. In patients with bilateral disease, the chance of subsequent contralateral THA reportedly ranges from 16% to 85%. Factors influencing contralateral THA are not completely understood. QUESTIONS/PURPOSES: We therefore determined (1) the 10-year probability free of progression to contralateral THA after index THA, (2) whether demographics differed between those who did and did not ultimately undergo contralateral THA, and (3) whether initial clinical symptoms and/or degree of radiographic osteoarthritis affects progression. PATIENTS AND METHODS: We retrospectively identified 332 patients with minimum 24-month followup and primary osteoarthritis who underwent unilateral THA between 2001 and 2008. There were 150 men and 182 women with a mean age of 61 years (range, 27-93 years) and a mean BMI of 29.6 kg/m(2) (range, 17.6-49.2 kg/m(2)). We reviewed clinical, radiographic, and demographic data at index THA and last followup and classified patients as low, indeterminate, or high risk of undergoing contralateral THA. RESULTS: Seventy-four of the 332 patients (22%) underwent contralateral THA, resulting in an 83% 10-year probability free of progression to the contralateral hip. Low-risk patients had a less than 1% chance of progression, indeterminate-risk patients had a 16% to 24% chance of progression, and high-risk patients had a 97% chance of progression. CONCLUSIONS: Indeterminate-risk patients may be managed nonoperatively and deserve further study with a larger multicenter analysis. We defined high- and low-risk patients who may be candidates for bilateral THA or may rarely need a contralateral THA. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Minimizing dynamic knee spacer complications in infected revision arthroplasty.

BACKGROUND: Deep infections are devastating complications of TKA often treated with component explantation, intravenous antibiotics, and antibiotic-impregnated cement spacers. Historically, the spacers have been static, which may limit patients' ROM and ability to walk. Several recent reports describe dynamic spacers, which may allow for improved ROM and make later reimplantation easier. However, because of several dynamic spacer problems noted at our institution, we wanted to assess their associated failures, reinfection rates, and functionality. QUESTIONS/PURPOSES: We therefore asked whether there were differences between static and dynamic spacers in (1) reinfection rates, (2) complications directly related to the spacer, and (3) final patient functionality as measured by Knee Society objective scores and ROM. PATIENTS AND METHODS: We retrospectively identified 111 patients (115 knees) with 34 dynamic spacers (30%) and 81 static spacers (70%). Reinfection rates, complications requiring additional surgery, and final Knee Society scores and ROM were collected for all patients. RESULTS: Reinfection rates were comparable between groups. In the dynamic spacer cohort, there were four complications; however, these could all be explained by surgical technical errors or patient weightbearing compliance. All patients with failed results eventually underwent successful two-stage exchange arthroplasty. Final Knee Society scores and ROM were also similar between groups. CONCLUSIONS: Reinfection rates, Knee Society scores, and ROM were comparable between the static and dynamic spacer groups. Meticulous surgical technique and proper patient selection should be used to avoid any complications with any spacers.

Reconstructive knee surgery literature as a tool for the orthopaedic in-training examination.

UNLABELLED: The Orthopaedic In-Training Examination (OITE) provides a standardized measure to assess the knowledge of orthopaedic residents regarding knee reconstruction surgery. However, there currently are limited resources for residents who are preparing for the knee reconstruction questions on the OITE. The present study assessed the character of the knee reconstruction questions tested and which literature resources may be recommended for residents preparing for this examination. MATERIALS AND METHODS: All knee reconstruction-related questions found during a 5-year period (2002 to 2006) on the OITE were characterized by the diagnosis and treatment discussed. The most frequently referenced journals were identified from the OITE exam key. The character of the OITE questions was compared to the literature in terms of overall proportion of articles and questions that were related to knee reconstruction, as well as to categories of diagnosis and treatment modality. RESULTS: There were 59 out of 1375 questions (4%) on the OITE over the 5 years that were related to knee reconstruction. Over half of the questions (54%) were related to primary total knee arthroplasty, with osteoarthritis being the most frequently tested diagnosis (30%). The top three referenced orthopaedic journals were The Journal of Bone and Joint Surgery-American, Clinical Orthopaedics and Related Research, and The Journal of Arthroplasty. Compared to the OITE, these journals covered higher percentages of overall knee reconstruction-related questions (18% versus 4%). In addition, the journal literature had a greater focus on treatment modalities (65% versus 41%) and less emphasis on biomechanics, materials, and basic science (18% versus 34%) than the OITE, respectively. The two most frequently cited textbooks represented approximately 78% of the total number of provided textbook references: Orthopaedic Knowledge Update (39%) and Instructional Course Lectures (39%). DISCUSSION: The results of this study suggest that residents may benefit from using general orthopaedic journals such as The Journal of Bone and Joint Surgery-American in preparation for the OITE. However, residents and residency directors who are preparing their educational programs should be aware that clinical journals may not refect the OITE in terms of the proportion of basic science and biomechanics articles and additional study resources may be necessary.

Early outcomes of sequentially cross-linked thin polyethylene liners with large diameter femoral heads in total hip arthroplasty.

UNLABELLED: Two important issues affecting the outcome of total hip arthroplasty have been dislocation and wear, despite excellent clinical results. Larger femoral heads have had success in decreasing dislocation rates; however, there are concerns regarding the subsequent use of thinner polyethylene liners, and their effects on wear rates. Historically, high stresses on thin polyethylene bearings have caused concerns, including rim cracking and catastrophic implant failure with polyethylene thicknesses less than 5 millimeters. Recently, sequentially cross-linked and annealed polyethylene has been shown to reduce the wear rate significantly, compared to conventional ultra-high-molecular-weight polyethylene (UHMWPE) in vitro. The purpose of this study was to analyze the clinical and radiographic outcomes in a cohort of patients treated with sequentially cross-linked and annealed polyethylene bearings with a nominal thickness of 3.8 millimeters. Outcomes were compared to a similar cohort of patients who were treated with total hip arthroplasty during the same time period and utilizing the same polyethylene thickness of 5.8 millimeters or greater. MATERIALS AND METHODS: We identified 50 patients (53 hips) who had a minimum 2-year clinical and radiographic follow-up after a standard total hip arthroplasty, performed with a thin, sequentially cross-linked and annealed polyethylene bearing surface. There were 15 males and 35 females, with a a mean age of 60 years (range, 16 to 93 years) and a mean body mass index of 28.6 kg/m² (range, 17.2 to 47.5 kg/m²). Overall survivorship was compared to a cohort of 50 patients (53 hips) treated with total hip arthroplasty during the same time period, utilizing the same polyethylene of 5.8 millimeters or greater thickness. Radiographic analysis of polyethylene wear was performed on a subset of 26 hips, using a previously validated two-dimensional computer-aided technique. Volumetric wear was calculated and subsequent annual volumetric and linear wear rates were derived for each patient in the study cohort. Additionally, radiographic analysis was performed to assess for any progressive radio-lucencies or malalignment. RESULTS: The overall survivorship of the study cohort was 100%, compared to a 96% survivorship in the comparison group (two failures due to infection). The mean Harris hip scores in the thin polyethylene cohort improved from 43 points (range, 10 to 67 points) pre-operatively to 91 points (range, 69 to 100 points) postoperatively. Upon radiographic review, no malalignment, radiolucencies, or polyethylene fracture was noted in the study cohort. The mean volumetric wear rate was 0.4122 mm³/year (range, 0.2311 to 0.7310 mm³/year), and the mean linear wear rate was 0.0004 mm/year (range, 0.0002 to 0.0007 mm/year) for the thin polyethylene group. The mean volumetric wear was 0.8839 mm³ (range, 0.4621 to 1.5839 mm³) for this cohort. Excellent clinical and radiographic outcomes were found for patients treated with thin, sequentially cross-linked and annealed polyethylene bearings utilized in total hip arthroplasty, with a nominal thickness of 3.8 millimeters. We have not seen any failures with thin polyethylene liners that have undergone this manufacturing process, which is in contradistinction to results of previously reported thin polyethylene liners. Wear rates were lower than other bearing surfaces at similar periods.

Literature recommended as study aids for the hip reconstruction section of the orthopaedic in-training examination.

One section of the Orthopaedic In-Training Examination (OITE) assesses knowledge about hip reconstruction. In the investigation reported here, we examined OITE hip reconstruction questions and sought to identify which literature can be recommended as study aids for this section of the test. All hip reconstruction questions on the OITE from 2002 to 2006 were characterized according to diagnosis and treatment. Journals cited most often in this section were identified from the OITE key. This content domain was compared with the literature in terms of overall proportion of questions/articles related to hip reconstruction and in terms of diagnoses and treatments. Of the 1375 OITE questions asked over the 5 years, 79 were related to hip reconstruction. More than half of these hip reconstruction questions were related to primary total hip arthroplasty, with complications being the diagnosis tested most often. The results of this study suggest that residents may benefit from using general orthopedic journals when preparing for the OITE hip reconstruction section. When preparing an educational program, however, one should be aware that clinical journals may not reflect the OITE in terms of proportion of basic science and biomechanics articles.

State of the art in hard-on-hard bearings: how did we get here and what have we achieved?

Total hip arthroplasty has shown excellent results in decreasing pain and improving function in patients with degenerative disease of the hip. Improvements in prosthetic materials, designs and implant fixation have now resulted in wear of the bearing surface being the limitation of this technology, and a number of hard-on-hard couples have been introduced to address this concern. The purpose of this article is to review the origins, development, survival rates and potential advantages and disadvantages of the following hard-on-hard bearings for total hip arthroplasty: metal-on-metal standard total hip arthroplasty; metal-on-metal hip resurfacing arthroplasty, ceramic-on-ceramic total hip arthroplasty; and ceramic-on-metal bearings. Improvements in the manufacturing of metal-on-metal bearings over the past 50 years have resulted in implants that provide low wear rates and allow for the use of large femoral heads. However, concerns remain regarding elevated serum metal ion levels, potential teratogenic effects and potentially devastating adverse local tissue reactions, whose incidence and pathogenesis remains unclear. Modern total hip resurfacing has shown excellent outcomes over 10 years in the hands of experienced surgeons. Current ceramic-on-ceramic bearings have demonstrated excellent survival with exceptionally low wear rates and virtually no local adverse effects. Concerns remain for insertional chipping, in vivo fracture and the variable incidence of squeaking. Contemporary ceramic-on-metal interfaces are in the early stages of clinical use, with little data reported to date. Hard-on-hard bearings for total hip arthroplasty have improved dramatically over the past 50 years. As bearing designs continue to improve with new and modified materials and improved manufacturing techniques, it is likely that the use of hard-on-hard bearings will continue to increase, especially in young and active patients.

Survival of hard-on-hard bearings in total hip arthroplasty: a systematic review.

BACKGROUND: Improvements in prosthetic materials, designs, and implant fixation for THA have led to bearing surface wear being the limitation of this technology. Hard-on-hard bearings promise decreased wear rates and increased survival. However, there may be different survival rates based on bearing materials, manufacturing technologies, and femoral component designs. Additionally, survival rate variability may be based on study design. QUESTIONS/PURPOSES: We determined survival rates and study levels of evidence and quality for the following bearings: stemmed metal-on-metal THA, metal-on-metal hip resurfacing, ceramic-on-ceramic THA, and ceramic-on-metal THA. METHODS: We performed a systematic review of the peer-reviewed literature addressing THA hard-on-hard bearings. Quality for Level I and II studies was assessed. RESULTS: The four Level I or II second-generation stemmed metal-on-metal THA studies reported between 96% and 100% mean survival at 38 to 60 months. The two Level I hip resurfacing studies reported 94% and 98% mean survival at 56 and 33 months. The four Level I studies of ceramic-on-ceramic THA reported survival from 100% at mean 51 months to 96% at 8 years. CONCLUSIONS: While hard-on-hard bearing survival rates have generally been variable with earlier designs, contemporary implants have demonstrated survival of 95% or greater at followup of between 3 and 10 years. Some variability in survival may be due to differences in surgical technique, component positioning, and implant designs. As bearing designs continue to improve with modified materials and manufacturing techniques, use will increase, especially in young and active patients, though concerns remain about the increased reports of adverse events after metal-on-metal bearings.

The risk of subsequent joint arthroplasty after primary unilateral total knee arthroplasty, a 10-year study.

The purposes of this study were to determine the probabilities of subsequent lower extremity arthroplasty after index knee arthroplasty for osteoarthritis and to evaluate the demographic as well as radiographic factors that may predict progression to arthroplasty in the contralateral knee. Between 1984 and 1994, 646 patients, aged 40 to 75 years, with a primary cruciate-retaining knee were identified. The 10-year probability of having a contralateral knee after index knee was 36%. When grade 4 radiographic changes were present, the probability increased to 70%. Demographic factors played no role in the risk of future contralateral knee. The radiographic grade of the contralateral knee at the time of index surgery was found to correlate strongly with the future risk of contralateral total knee.

Hip resurfacing in patients who have osteonecrosis and are 25 years or under.

BACKGROUND: Young patients with osteonecrosis (ON) treated with THA often have suboptimal function and radiographic failure with eventual revision. Resurfacing may be an option because of potentially increased functionality and decreased radiographic failure, although neither has been confirmed in the literature. QUESTIONS/PURPOSES: We therefore compared the clinical scores and radiographic failures of resurfacing patients 25 years or younger with osteonecrosis with those for patients with ON treated with THA. METHODS: We identified 17 patients (20 resurfaced hips) who were 25 years or younger and treated by resurfacing for ON. Mean followup was 62 months (range, 32-103 months). This group was matched by gender, age, BMI, and followup to 16 patients (20 hips) treated with THA with a mean 61 month followup (range, 34-88 months). Additionally, the group was compared to 78 patients (87 hips) with ON over age 25 who underwent resurfacing during the same time with a mean followup of 61 months (range, 27-112 months). RESULTS: The mean Harris score improved from 48 points preoperatively to 93 points with a 100% 7.5 year survivorship in the young resurfacing group. In the THA cohort, the mean score improved from 44 points preoperatively to 94 points postoperatively, with a 93.3% 7.5 year survivorship; similar to the results for all resurfacing patients. Radiographs did not reveal malalignment or progressive radiolucencies in any cohort. CONCLUSION: At approximately 5 year followup, young resurfacing patients were similar to other resurfacing patients and standard THA patients regarding clinical ratings and radiographic failures.