A prospective randomized controlled trial comparing CT-based planning with conventional total hip arthroplasty versus robotic arm-assisted total hip arthroplasty.

Aims: Achieving accurate implant positioning and restoring native hip biomechanics are key surgeon-controlled technical objectives in total hip arthroplasty (THA). The primary objective of this study was to compare the reproducibility of the planned preoperative centre of hip rotation (COR) in patients undergoing robotic arm-assisted THA versus conventional THA. Methods: This prospective randomized controlled trial (RCT) included 60 patients with symptomatic hip osteoarthritis undergoing conventional THA (CO THA) versus robotic arm-assisted THA (RO THA). Patients in both arms underwent pre- and postoperative CT scans, and a patient-specific plan was created using the robotic software. The COR, combined offset, acetabular orientation, and leg length discrepancy were measured on the pre- and postoperative CT scanogram at six weeks following surgery. Results: There were no significant differences for any of the baseline characteristics including spinopelvic mobility. The absolute error for achieving the planned horizontal COR was median 1.4 mm (interquartile range (IQR) 0.87 to 3.42) in RO THA versus 4.3 mm (IQR 3 to 6.8; p < 0.001); vertical COR mean 0.91 mm (SD 0.73) in RO THA versus 2.3 mm (SD 1.3; p < 0.001); and combined offset median 2 mm (IQR 0.97 to 5.45) in RO THA versus 3.9 mm (IQR 2 to 7.9; p = 0.019). Improved accuracy was observed with RO THA in achieving the desired acetabular component positioning (root mean square error for anteversion and inclination was 2.6 and 1.3 vs 8.9 and 5.3, repectively) and leg length (mean 0.6 mm vs 1.4 mm; p < 0.001). Patient-reported outcome measures were comparable between the two groups at baseline and one year. Participants in the RO THA group needed fewer physiotherapy sessions postoperatively (median six (IQR 4.5 to 8) vs eight (IQR 6 to 11; p = 0.005). Conclusion: This RCT suggested that robotic-arm assistance in THA was associated with improved accuracy in restoring the native COR, better preservation of the combined offset, leg length correction, and superior accuracy in achieving the desired acetabular component positioning. Further evaluation through long-term and registry data is necessary to assess whether these findings translate into improved implant survival and functional outcomes.

Patient-Reported Outcome Measures in Conventional Total Hip Arthroplasty Versus Robotic-Arm Assisted Arthroplasty: A Prospective Cohort Study With Minimum 3 Years' Follow-Up.

BACKGROUND: Robotic-arm assisted total hip arthroplasty (RO THA) has been shown to improve the accuracy of component positioning compared with conventional total hip arthroplasty (CO THA). This study reports Patient-Reported Outcome Measures (PROMs) of a previous trial that showed that RO THA was associated with improved accuracy and reduced outliers in acetabular component positioning compared with CO THA. METHODS: This prospective cohort study included 50 patients undergoing CO THA versus 50 patients receiving RO THA. The Oxford hip score, Forgotten Joint Score (FJS), University of California at Los Angeles hip score were recorded at a minimum of 3 years following surgery. RESULTS: At minimum 3 years follow-up, there was no statistically significant difference in CO THA versus RO THA with respect to the Oxford hip score [median 42(6.25) versus 41(5.5), P = .914]; FJS [89 (9.25) versus 86 (9), P = .065], and University of California at Los Angeles score [median 7.5 (3) versus 7 (2), P = .381]. None of the study patients had dislocations or underwent revision surgery within 3 years follow-up. CONCLUSION: The previously reported improvement in accuracy of acetabular component in this study population did not translate to statistically significant improvements in PROMs. Patients in both groups achieved excellent PROMs and there was a trend towards higher FJS scores postoperatively in the RO THA group that did not reach statistical significance. Further studies are needed to assess the significance of these findings on longer-term clinical outcomes and implant survivorships, and also to explore the impact of the enhanced RO THA workflow and functional implant positioning on these outcomes.

Inflammatory Response in Robotic-Arm-Assisted Versus Conventional Jig-Based TKA and the Correlation with Early Functional Outcomes: Results of a Prospective Randomized Controlled Trial.

BACKGROUND: Although the exact etiology of patient dissatisfaction in total knee arthroplasty (TKA) is unclear, the inflammatory response precipitated by surgery may be implicated. Robotic TKA has been shown to result in reduced bone and soft-tissue trauma. The objectives of this study were to compare the inflammatory response in conventional jig-based TKA versus robotic-arm-assisted TKA and to examine the relationship with early functional outcomes. METHODS: This prospective randomized controlled trial included 15 patients with symptomatic knee osteoarthritis undergoing conventional TKA and 15 undergoing robotic-arm-assisted TKA. Blood samples were collected for up to 28 days postoperatively, and predefined markers of systemic inflammation were measured in serum. The local inflammatory response was assessed by analyzing samples from the intra-articular drain fluid at 6 and 24 hours. Relationships with early functional outcomes were evaluated using the Spearman rank correlation coefficient. RESULTS: Patients in the robotic TKA group demonstrated lower levels of interleukin (IL)-6 in the drain fluid at 6 hours (798.54 pg/mL versus 5,699.2 pg/mL, p = 0.026) and 24 hours and IL-8 at 6 hours. Robotic TKA was associated with lower pain scores on postoperative days 1, 2, and 7. Patient-reported outcome measures were comparable between the 2 groups at 2 years. Significant correlations were observed between all serum markers except IL-1b and self-reported pain on postoperative day 7; between drain IL-8 levels and pain on postoperative days 1 (r = 0.458), 2, and 7; and between drain IL-6, IL-8, and tumor necrosis factor-alpha levels at 6 hours and knee flexion or extension. CONCLUSIONS: Robotic-arm-assisted TKA was associated with a reduction in the early postoperative local inflammatory response. We also found a moderate relationship between the inflammatory responses and self-reported pain, knee flexion, and knee extension. Further validation of these findings on a larger scale and using longer-term outcomes will be key to developing the optimal TKA procedure. LEVEL OF EVIDENCE: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

Oxidized zirconium versus cobalt-chrome femoral heads in total hip arthroplasty: a multicentre prospective randomized controlled trial with ten years' follow-up.

AIMS: This study reports the ten-year wear rates, incidence of osteolysis, clinical outcomes, and complications of a multicentre randomized controlled trial comparing oxidized zirconium (OxZr) versus cobalt-chrome (CoCr) femoral heads with ultra-high molecular weight polyethylene (UHMWPE) and highly cross-linked polyethylene (XLPE) liners in total hip arthroplasty (THA). METHODS: Patients undergoing primary THA were recruited from four institutions and prospectively allocated to the following treatment groups: Group A, CoCr femoral head with XLPE liner; Group B, OxZr femoral head with XLPE liner; and Group C, OxZr femoral head with UHMWPE liner. All study patients and assessors recording outcomes were blinded to the treatment groups. The outcomes of 262 study patients were analyzed at ten years' follow-up. RESULTS: Patients in Group C were associated with increased mean liner wear rates compared to patients in Group A (0.133 mm/yr (SD 0.21) vs 0.031 mm/yr (SD 0.07), respectively; p < 0.001) and Group B (0.133 mm/yr (SD 0.21) vs 0.022 mm/yr (SD 0.05), respectively; p < 0.001) at ten years' follow-up. Patients in Group C were also associated with increased risk of osteolysis and aseptic loosening requiring revision surgery, compared with patients in Group A (7/133 vs 0/133, respectively; p = 0.007) and Group B (7/133 vs 0/135, respectively; p = 0.007). There was a non-statistically significant trend towards increased mean liner wear rates in Group A compared with Group B (0.031 mm/yr (SD 0.07) vs 0.022 mm/yr (SD 0.05), respectively; p = 0.128). All three groups were statistically comparable preoperatively and at ten years' follow-up when measuring normalized Western Ontario and McMaster Universities Osteoarthritis Index (p = 0.410), 36-Item Short Form Health Survey (p = 0.465 mental, p = 0.713 physical), and pain scale scores (p = 0.451). CONCLUSION: The use of UHMWPE was associated with progressively increased annual liner wear rates after THA compared to XLPE. At ten years' follow-up, the group receiving UHMWPE demonstrated an increased incidence of osteolysis and aseptic loosening requiring revision surgery compared to XLPE. Femoral heads composed of OxZr were associated with trend towards reduced wear rates compared to CoCr, but this did not reach statistical significance and did not translate to any differences in osteolysis, functional outcomes, or revision surgery between the two femoral head components. Cite this article: Bone Joint J 2022;104-B(7):833-843.

A Prospective Randomized Controlled Trial Comparing Medial-Pivot versus Posterior-Stabilized Total Knee Arthroplasty.

BACKGROUND: The medial-pivot (MP) design for total knee arthroplasty (TKA) aims to restore more natural "ball-and-socket" knee kinematics compared to the traditional posterior-stabilized (PS) implants for TKA. The objective of this study is to determine if there was any difference in functional outcomes between patients undergoing MP-TKA vs PS-TKA. METHODS: This prospective randomized controlled trial consisted of 43 patients undergoing MP-TKA vs 45 patients receiving a single-radius PS-TKA design. The primary outcome was postoperative range of motion (ROM). Secondary outcomes included the Western Ontario and McMaster Universities Arthritis Index, Oxford Knee Score, Knee Society Score (KSS), and radiological outcomes. All study patients were followed-up for 2 years after surgery. RESULTS: Patients undergoing MP-TKA had comparable ROM at 1 year (114.6° ± 16.3° vs 111.3° ± 17.8° respectively, P = .88) and 2 years after surgery (114.9° ± 15.5° vs 114.9° ± 16.4° respectively, P = .92) compared to PS-TKA. There were also no differences in Western Ontario and McMaster Universities Arthritis Index (26.8 ± 19.84 vs 22.0 ± 12.03 respectively, P = .14), Oxford Knee Score (42.7 ± 8.1 vs 42.3 ± 6.7 respectively, P = .18), KSS clinical scores (82.9 ± 16.96 vs 81.42 ± 10.45 respectively, P = .12) and KSS functional scores (76.2 ± 18.81 vs 73.93 ± 8.53 respectively, P = .62) at 2-year follow-up. There was no difference in postoperative limb alignment or complications. CONCLUSION: This study demonstrated excellent results in both the single-radius PS-TKA design and MP-TKA design. No differences were identified at 2-year follow-up with respect to postoperative ROM and patient-reported outcome measures.

A prospective randomized controlled trial comparing the systemic inflammatory response in conventional jig-based total knee arthroplasty versus robotic-arm assisted total knee arthroplasty.

AIMS: The primary aim of this study was to compare the postoperative systemic inflammatory response in conventional jig-based total knee arthroplasty (conventional TKA) versus robotic-arm assisted total knee arthroplasty (robotic TKA). Secondary aims were to compare the macroscopic soft tissue injury, femoral and tibial bone trauma, localized thermal response, and the accuracy of component positioning between the two treatment groups. METHODS: This prospective randomized controlled trial included 30 patients with osteoarthritis of the knee undergoing conventional TKA versus robotic TKA. Predefined serum markers of inflammation and localized knee temperature were collected preoperatively and postoperatively at six hours, day 1, day 2, day 7, and day 28 following TKA. Blinded observers used the Macroscopic Soft Tissue Injury (MASTI) classification system to grade intraoperative periarticular soft tissue injury and bone trauma. Plain radiographs were used to assess the accuracy of achieving the planned postioning of the components in both groups. RESULTS: Patients undergoing conventional TKA and robotic TKA had comparable changes in the postoperative systemic inflammatory and localized thermal response at six hours, day 1, day 2, and day 28 after surgery. Robotic TKA had significantly reduced levels of interleukin-6 (p < 0.001), tumour necrosis factor-α (p = 0.021), ESR (p = 0.001), CRP (p = 0.004), lactate dehydrogenase (p = 0.007), and creatine kinase (p = 0.004) at day 7 after surgery compared with conventional TKA. Robotic TKA was associated with significantly improved preservation of the periarticular soft tissue envelope (p < 0.001), and reduced femoral (p = 0.012) and tibial (p = 0.023) bone trauma compared with conventional TKA. Robotic TKA significantly improved the accuracy of achieving the planned limb alignment (p < 0.001), femoral component positioning (p < 0.001), and tibial component positioning (p < 0.001) compared with conventional TKA. CONCLUSION: Robotic TKA was associated with a transient reduction in the early (day 7) postoperative inflammatory response but there was no difference in the immediate (< 48 hours) or late (day 28) postoperative systemic inflammatory response compared with conventional TKA. Robotic TKA was associated with decreased iatrogenic periarticular soft tissue injury, reduced femoral and tibial bone trauma, and improved accuracy of component positioning compared with conventional TKA. Cite this article: Bone Joint J 2021;103-B(1):113-122.

Computerised tomography-based planning with conventional total hip arthroplasty versus robotic-arm assisted total hip arthroplasty: study protocol for a prospective randomised controlled trial.

BACKGROUND: Robotic-arm assisted surgery aims to reduce manual errors and improve the accuracy of implant positioning during total hip arthroplasty. The objective of this study is to compare the accuracy of implant positioning, restoration of hip biomechanics, patient satisfaction, functional outcomes, implant survivorship, cost-effectiveness, and complications in conventional manual total hip arthroplasty (CO THA) versus robotic-arm assisted total hip arthroplasty (RO THA). Preoperative pelvic computerised tomography (CT) scans will be used to create patient-specific, virtual, three-dimensional reconstructions for surgical planning in both treatment groups. METHODS AND ANALYSIS: This prospective randomised controlled trial will include 60 patients with symptomatic hip osteoarthritis undergoing primary THA. Following informed consent, patients will be randomised to CO THA (control group) or RO THA (investigation group) at a ratio of 1:1 using an online random number generator. Observers will review patients at regular intervals for 2 years after surgery to record predefined study outcomes relating to the accuracy of implant positioning, hip biomechanics, postoperative rehabilitation, clinical progress, functional outcomes, cost-effectiveness, and complications. Primary and secondary objectives will be used to quantify and draw inferences on differences in the efficacy of treatment between the two groups. Intention-to-treat and per-protocol population analysis will be undertaken. Intention to treat relates to the allocated treatment (CO THA or RO THA), and per-protocol refers to the actual treatment received by the patient. The following statistical methods will be employed to analyse the data: descriptive statistics, independent t test, paired t test, analysis of variance, Fisher exact test, chi-square test, and graphical displays. Ethical approval was obtained from the London-Bromley Research Ethics Committee, UK. The study is sponsored by University College London, UK. DISCUSSION: This study compares a comprehensive and robust range of clinical, functional, and radiological outcomes in CT-planned CO THA versus CT-planned RO THA. The findings of this study will enable an improved understanding of the differences in CO THA versus RO THA with respect to patient satisfaction, functional outcomes, implant survivorship, cost-effectiveness, and complications. TRIAL REGISTRATION: ClinicalTrials.gov NCT04095845 . Registered on 19 September 2019.

Robotic-arm assisted medial unicondylar knee arthroplasty versus jig-based unicompartmental knee arthroplasty with navigation control: study protocol for a prospective randomised controlled trial.

BACKGROUND: There remains a paucity of clinical studies assessing how any differences in accuracy of implant positioning between robotic-arm assisted unicompartmental knee arthroplasty (RO UKA) and conventional jig-based unicompartmental knee arthroplasty (CO UKA) translate to patient satisfaction, functional outcomes, and implant survivorship. The objectives of this study are to compare accuracy of implant positioning, limb alignment, patient satisfaction, functional outcomes, implant survivorship, cost-effectiveness, and complications in CO UKA versus RO UKA. Computer navigation will be used to assess intraoperative knee kinematics in all patients undergoing CO UKA. METHODS AND ANALYSIS: This prospective randomised controlled trial will include 140 patients with symptomatic medial compartment knee arthritis undergoing primary UKA. Following informed consent, patients will be randomised to CO UKA (control group) or RO UKA (investigation group) at a ratio of 1:1 using an online random number generator. The primary objective of this study is to compare accuracy of implant positioning in CO UKA versus RO UKA. The secondary objectives are to compare the following outcomes between the two treatment groups: limb alignment, surgical efficiency, postoperative functional rehabilitation, functional outcomes, quality of life, range of motion, resource use, cost effectivness, and complications. Observers will review patients at regular intervals for 2 years after surgery to record predefined study outcomes pertaining to these objectives. Ethical approval was obtained from the London-Bloomsbury Research Ethics Committee, UK. The study is sponsored by University College London, UK. DISCUSSION: This study compares a comprehensive and robust range of clinical, functional, and radiological outcomes in CO UKA versus RO UKA. The findings of this study will provide an improved understanding of the differences in CO UKA versus RO UKA with respect to accuracy of implant positioning, patient satisfaction, functional outcomes, implant survivorship, cost-effectiveness, and complications. TRIAL REGISTRATION: ClinicalTrials.gov NCT04095637 . Registered on 19 September 2019.

Long-Term Results of Revision Total Hip Arthroplasty Using a Modern Extensively Porous-Coated Femoral Stem.

BACKGROUND: The use of an extensively porous-coated uncemented cobalt-chrome monoblock femoral stem for revision total hip arthroplasty (THA) is well established with excellent mid-term results. The aim of this study is to report the long-term survivorship of these implants in femoral stem revisions. METHODS: This is a long-term retrospective review of prospectively collected data of 55 femoral stem revisions in 55 patients using a contemporary, cementless extensively porous-coated cobalt-chrome monoblock stem. All patients between 2001 and 2006 who underwent first time femoral stem revision with a contemporary, cementless extensively porous-coated cobalt-chrome monoblock stem were included. Harris Hip Score, Western Ontario and McMaster Universities Index, and University of California Los Angeles activity scores were recorded preoperatively and at latest follow-up. Radiographs were analyzed for evidence of loosening, subsidence, osteolysis, and bony union. This study included 55 patients, comprising of 36 females (66%) and 19 males (34%) with a mean age of 66.4 ± 9.3 years at the time of surgery. The mean time interval from index procedure was 9.8 ± 2.9 years. Mean time from revision THA to final follow-up was 13.2 ± 2.17 years with a minimum of 10 years of follow-up. RESULTS: Indications for revision included aseptic loosening (33), prosthetic joint infection (13), and periprosthetic fracture (10). Significant improvement in Harris Hip Score (85.1 ± 1.77 vs 51.8 ± 2.3, P < .001), Western Ontario and McMaster Universities Index (17.6 ± 0.77 vs 33.3 ± 0.8, P < .001), and University of California Los Angeles (5.25 ± 0.2 vs 2.7 ± 0.36, P < .001) scores were found at latest follow-up compared to preoperative. Fifty-four patients (98%) achieved stable bony ingrowth on radiographic analysis. All 10 patients treated for periprosthetic fractures achieved bony union of their fractures. Two patients suffered intraoperative periprosthetic fractures and were treated with a cable-plating system. There were no mechanical failures and no femoral stem re-revisions. One patient was diagnosed with a deep infection and was treated with chronic suppressive antibiotic therapy due to significant medical comorbidities. CONCLUSION: Revision of the femoral component with a contemporary extensively porous-coated cobalt-chrome femoral stem has excellent functional outcomes, radiographic outcomes, and long-term survivorship with minimal complications.

The direct superior approach versus posterior approach for total hip arthroplasty: study protocol for a prospective double-blinded randomised control trial.

BACKGROUND: The direct superior approach (DSA) is a minimally invasive modification of the posterior approach (PA) that preserves the iliotibial band and short external rotators except for the piriformis or conjoint tendon during total hip arthroplasty (THA). The objective of this study is to compare patient satisfaction, functional outcomes, accuracy of implant positioning, component stability, gait, cost-effectiveness, and complications in the DSA versus PA for THA. METHODS AND ANALYSIS: This prospective double-blinded randomised control trial will include 80 patients with symptomatic hip osteoarthritis undergoing primary THA. Following informed consent, patients will be randomised to THA using the PA (control group) or DSA (investigation group) at a ratio of 1:1 using an online random number generator. Blinded observers will review patients at regular intervals for 2 years after surgery to record predefined study outcomes relating to postoperative rehabilitation, clinical progress, functional outcomes, accuracy of implant positioning, gait analysis on force plate treadmill, implant migration with radiosteriometric analysis, cost-effectiveness, and complications. A superiority study design will be used to evaluate whether the DSA provides improved outcomes compared to the PA for THA. Evaluation of study outcomes in DSA and PA will be used to quantify and draw inferences on differences in the efficacy of treatment between the two groups. Intention-to-treat and per-protocol population analysis will be undertaken. The following statistical methods will be employed to analyse the data: descriptive statistics, independent t test, paired t test, analysis of variance, Fisher exact test, chi-square test, and graphical displays. Ethical approval was obtained from the London-Fulham Research Ethics Committee, UK. The study is sponsored by University College London, UK. DISCUSSION: This study compares a comprehensive and robust range of clinical, functional, and radiological outcomes in THA performed using the PA versus DSA. The findings of this study will provide an improved understanding of the differences in the PA versus DSA for THA with respect to patient satisfaction, functional outcomes, implant survivorship, gait, cost-effectiveness, and complications. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04191993. Registered on 10 December 2019.

A prospective double-blinded randomised control trial comparing robotic arm-assisted functionally aligned total knee arthroplasty versus robotic arm-assisted mechanically aligned total knee arthroplasty.

BACKGROUND: Total knee arthroplasty (TKA) with mechanical alignment (MA) aims to achieve neutral limb alignment in all patients, whereas TKA with functional alignment (FA) aims to restore native, patient-specific anatomy and knee kinematics by manipulating bone resections and fine-tuning implant positioning. The objective of this study is to determine the optimal alignment technique in TKA by comparing patient satisfaction, functional outcomes, implant survivorship, complications, and cost-effectiveness in MA TKA versus FA TKA. Robotic technology will be used to execute the planned implant positioning and limb alignment with high-levels of accuracy in all study patients. METHODS AND ANALYSIS: This prospective double-blinded randomised control trial will include 100 patients with symptomatic knee osteoarthritis undergoing primary robotic arm-assisted TKA. Following informed consent, patients will be randomised to MA TKA (the control group) or FA TKA (the investigation group) at a ratio of 1:1 using an online random number generator. Blinded observers will review patients at regular intervals for 2 years after surgery to record predefined study outcomes relating to postoperative rehabilitation, clinical progress, functional outcomes, accuracy of implant positioning and limb alignment, gait, implant stability, cost-effectiveness, and complications. A superiority study design will be used to evaluate whether FA TKA provides superior outcomes compared to MA TKA. Primary and secondary objectives will be used to quantify and draw inferences on differences in the efficacy of treatment between the two groups. Intention-to-treat and per-protocol population analysis will be undertaken. The following statistical methods will be employed to analyse the data: descriptive statistics, independent t test, paired t test, analysis of variance, Fisher exact test, chi-square test, and graphical displays. Ethical approval was obtained from the London-Surrey Research Ethics Committee, UK. The study is sponsored by University College London, UK. DISCUSSION: This is the first study to describe the use of robotic technology to achieve FA TKA, and the only existing clinical trial comparing robotic MA TKA versus robotic FA TKA. The findings of this study will enable an improved understanding of the optimal alignment technique in TKA for achieving high-levels of patient satisfaction, improving functional outcomes, increasing implant survivorship, improving cost-effectiveness, and reducing complications. REGISTRATION: Clinical Trials.gov, NCT04092153. Registered on 17 September 2019.

Return to sport after lower limb arthroplasty - why not for all?

BACKGROUND: Total hip and knee replacements are being performed in increasing numbers in progressively younger patients with higher activity demands. Many such patients have expectations of returning to athletic activity post-operatively yet are not always able to do so and the reasons behind this have not been extensively examined. We hypothesise that any reasons for a failure to return to athletic activity post-operatively are multi-factorial. AIM: To quantify the return to athletic activity following lower limb joint arthroplasty and understand qualitative reasons for altered activity participation. METHODS: A single centre, single surgeon retrospective questionnaire for hip and knee arthroplasty patients under age 60 years, minimum two years post-surgery with exclusion criteria of multiple degenerative joint involvement and multiple medical co-morbidities. Outcomes were validated joint-specific (Oxford hip and knee) and lifestyle questionnaires [short form 12 (SF-12) and University of California, Los Angeles (UCLA)] and an activity questionnaire assessing ability participation in athletic activity post-operatively. Statistical analysis was performed on the validated outcome data, including comparison between hip and knee replacements. Frequency tables were produced to quantify the different athletic activities participated in by patients. RESULTS: Responses were received from 64 patients (80% response rate). There was a statistically significant improvement in Oxford hip and knee scores following surgery. SF-12 scores also improved for all patients, but no statistically significant difference was seen between joints (P = 0.88). Mean UCLA scores pre-operatively were 7.67 and at two years post-operatively were 7.69, with no statistically significant change (P = 0.91). All patients reported high satisfaction and improved ability to perform athletic activity at a higher frequency compared to pre-operatively. The most common reasons for changing activity participation were not wanting to stress their joint replacement or instructions by other doctors or the lead surgeon. There was no difference in the responses to the questionnaire based on type of joint replacement (P = 0.995). CONCLUSION: Patients receiving a joint replacement are able to participate in athletic activity to high levels and are satisfied with their outcomes. Reasons for non-participation are multi-factorial.

The development and validation of a more discriminating functional hip score for research.

BACKGROUND: Total hip arthroplasty (THA) is a commonly performed procedure with increasing frequency in the young adult. While most available outcome measures can document postoperative improvement in pain and function, they do not measure the ability to perform high-demand activities. QUESTIONS/PURPOSES: We present and validate a user-friendly discriminating hip scoring system (the functional hip score) for use in younger, "high-demand" patients undergoing hip arthroplasty surgery. METHODS: We studied 38 subjects without any hip symptoms and 72 patients undergoing THA for osteoarthritis of the hip. Preprocedure and postprocedure scores were collected in the latter cohort of patients. SF-36 and WOMAC scores were used to validate our functional scoring system. The functional hip score was tested for internal consistency, reliability, and criterion validity. RESULTS: The functional hip score had high test-retest reliability, internal consistency, and criterion validity. This can be used to measure functional outcome in the younger high-demand adult patient undergoing THA. CONCLUSION: Our discriminating functional hip score can reliably measure improvement in hip function in the younger high-demand adult. Current scoring systems have ceiling effects and are unable to differentiate a high performing hip replacement from the routine hip replacement. The use of functional tasks that are measured objectively allows better documentation of improvement in hip function.