Cost-utility analysis of robotic arm-assisted medial compartment knee arthroplasty.

Aims: To perform an incremental cost-utility analysis and assess the impact of differential costs and case volume on the cost-effectiveness of robotic arm-assisted unicompartmental knee arthroplasty (rUKA) compared to manual (mUKA). Methods: This was a five-year follow-up study of patients who were randomized to rUKA (n = 64) or mUKA (n = 65). Patients completed the EuroQol five-dimension questionnaire (EQ-5D) preoperatively, and at three months and one, two, and five years postoperatively, which was used to calculate quality-adjusted life years (QALYs) gained. Costs for the primary and additional surgery and healthcare costs were calculated. Results: rUKA was associated with a relative 0.012 QALY gain at five years, which was associated with an incremental cost per QALY of £13,078 for a unit undertaking 400 cases per year. A cost per QALY of less than £20,000 was achieved when ≥ 300 cases were performed per year. However, on removal of the cost for a revision for presumed infection (mUKA group, n = 1) the cost per QALY was greater than £38,000, which was in part due to the increased intraoperative consumable costs associated with rUKA (£626 per patient). When the absolute cost difference (operative and revision costs) was less than £240, a cost per QALY of less than £20,000 was achieved. On removing the cost of the revision for infection, rUKA was cost-neutral when more than 900 cases per year were undertaken and when the consumable costs were zero. Conclusion: rUKA was a cost-effective intervention with an incremental cost per QALY of £13,078 at five years, however when removing the revision for presumed infection, which was arguably a random event, this was no longer the case. The absolute cost difference had to be less than £240 to be cost-effective, which could be achieved by reducing the perioperative costs of rUKA or if there were increased revision costs associated with mUKA with longer follow-up.

In search of the ideal periosteal flap for bone non-union: The chimeric fibula-periosteal flap.

Vascularised periosteal flaps may increase the union rates in recalcitrant long bone non-union. The fibula-periosteal chimeric flap utilises the periosteum raised on an independent periosteal vessel. This allows the periosteum to be inset freely around the osteotomy site, thereby facilitating bone consolidation. PATIENTS AND METHODS: Ten patients underwent fibula-periosteal chimeric flaps (2016-2022) at the Canniesburn Plastic Surgery Unit, UK. Preceding non-union 18.6 months, with mean bone gap of 7.5 cm. Patients underwent preoperative CT angiography to identify the periosteal branches. A case-control approach was used. Patients acted as their own controls, with one osteotomy covered by the chimeric periosteal flap and one without, although in two patients both the osteotomies were covered using a long periosteal flap. RESULTS: A chimeric periosteal flap was used in 12 of the 20 osteotomy sites. Periosteal flap osteotomies had a primary union rate of 100% (11/11) versus those without flaps at 28.6% (2/7) (p = 0.0025). Union occurred in the chimeric periosteal flaps at 8.5 months versus 16.75 months in the control group (p = 0.023). One case was excluded from primary analysis due to recurrent mycetoma. The number needed to treat = 2, indicating that 2 patients would require a chimeric periosteal flap to avoid one non-union. Survival curves with a hazard ratio of 4.1 were observed, equating to a 4 times higher chance of union with periosteal flaps (log-rank p = 0.0016). CONCLUSIONS: The chimeric fibula-periosteal flap may increase the consolidation rates in difficult cases of recalcitrant non-union. This elegant modification of the fibula flap uses periosteum that is normally discarded, and this adds to the accumulating data supporting the use of vascularised periosteal flaps in non-union.

Survivorship of high tibial osteotomy in the treatment of osteoarthritis of the knee: a retrospective cohort study with fourteen years' follow-up.

PURPOSE: This study was to evaluate the survivorship of HTO for the treatment of medial compartment osteoarthritis (OA) in young and active patients from two teaching hospitals in a single city. METHODS: This is a retrospective cohort multicenter study looking at HTO for treatment of medial compartment OA. We analyzed a case series of HTO's performed by four surgeons in two centres over a 14-year period. Failure was defined as conversion to total knee replacement (TKR). All cases where additional procedures for instability of the knee were performed at the time of the index surgery were excluded. Time to failure was recorded, and a Kaplan-Meir (KM) analysis was performed to evaluate survivorship. Univariate binary regression analysis was undertaken to identify associations between risk factors and failure. RESULTS: A total of 96 patients were included in the study with a median age was 45 years. The survivorship at five years post-op was 90.3%, and at ten years post-op, it was 82%. Patients that were 14 years after surgery had a survivorship of 65%. Also, 18.8% of patients required the removal of their metalwork. The overall complication rate was 6.3%. The univariate regression analysis showed that higher age (p = 0.02) and larger corrections requiring the use of bone graft increased the risk of failure (p = 0.02). There was no statistically significant correlation between laterality, gender, complication rate, and pre-operative alignment to survivorship. CONCLUSION: This is one of the largest reported case series of HTO's with comparable survivorship at five and ten year follow-up compared to the reported literature. There was an association found between increasing age and larger corrections requiring bone graft at index procedure to increasing failure rate.

Are there functional biomechanical differences in robotic arm-assisted bi-unicompartmental knee arthroplasty compared with conventional total knee arthroplasty? A prospective, randomized controlled trial.

AIMS: The aim of this study was to compare any differences in the primary outcome (biphasic flexion knee moment during gait) of robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) at one year post-surgery. METHODS: A total of 76 patients (34 bi-UKA and 42 TKA patients) were analyzed in a prospective, single-centre, randomized controlled trial. Flat ground shod gait analysis was performed preoperatively and one year postoperatively. Knee flexion moment was calculated from motion capture markers and force plates. The same setup determined proprioception outcomes during a joint position sense test and one-leg standing. Surgery allocation, surgeon, and secondary outcomes were analyzed for prediction of the primary outcome from a binary regression model. RESULTS: Both interventions were shown to be effective treatment options, with no significant differences shown between interventions for the primary outcome of this study (18/35 (51.4%) biphasic TKA patients vs 20/31 (64.5%) biphasic bi-UKA patients; p = 0.558). All outcomes were compared to an age-matched, healthy cohort that outperformed both groups, indicating residual deficits exists following surgery. Logistic regression analysis of primary outcome with secondary outcomes indicated that the most significant predictor of postoperative biphasic knee moments was preoperative knee moment profile and trochlear degradation (Outerbridge) (R2 = 0.381; p = 0.002, p = 0.046). A separate regression of alignment against primary outcome indicated significant bi-UKA femoral and tibial axial alignment (R2 = 0.352; p = 0.029), and TKA femoral sagittal alignment (R2 = 0.252; p = 0.016). The bi-UKA group showed a significant increased ability in the proprioceptive joint position test, but no difference was found in more dynamic testing of proprioception. CONCLUSION: Robotic arm-assisted bi-UKA demonstrated equivalence to TKA in achieving a biphasic gait pattern after surgery for osteoarthritis of the knee. Both treatments are successful at improving gait, but both leave the patients with a functional limitation that is not present in healthy age-matched controls. Cite this article: Bone Joint J 2022;103-B(4):433-443.

Early outcomes after robotic arm-assisted bi-unicompartmental knee arthroplasty compared with total knee arthroplasty: a prospective, randomized controlled trial.

AIMS: The aim of this study was to compare the clinical outcomes of robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) during the first six weeks and at one year postoperatively. METHODS: A per protocol analysis of 76 patients, 43 of whom underwent TKA and 34 of whom underwent bi-UKA, was performed from a prospective, single-centre, randomized controlled trial. Diaries kept by the patients recorded pain, function, and the use of analgesics daily throughout the first week and weekly between the second and sixth weeks. Patient-reported outcome measures (PROMs) were compared preoperatively, and at three months and one year postoperatively. Data were also compared longitudinally and a subgroup analysis was conducted, stratified by preoperative PROM status. RESULTS: Both operations were shown to offer comparable outcomes, with no significant differences between the groups across all timepoints and outcome measures. Both groups also had similarly low rates of complications. Subgroup analysis for preoperative psychological state, activity levels, and BMI showed no difference in outcomes between the two groups. CONCLUSION: Robotic arm-assisted, cruciate-sparing bi-UKA offered similar early clinical outcomes and rates of complications to a mechanically aligned TKA, both in the immediate postoperative period and up to one year following surgery. Further work is required to identify which patients with osteoarthritis of the knee will derive benefit from a cruciate-sparing bi-UKA. Cite this article: Bone Joint J 2021;103-B(10):1561-1570.

Robotic arm-assisted versus conventional medial unicompartmental knee arthroplasty: five-year clinical outcomes of a randomized controlled trial.

AIMS: Unicompartmental knee arthroplasty (UKA) is a bone-preserving treatment option for osteoarthritis localized to a single compartment in the knee. The success of the procedure is sensitive to patient selection and alignment errors. Robotic arm-assisted UKA provides technological assistance to intraoperative bony resection accuracy, which is thought to improve ligament balancing. This paper presents the five-year outcomes of a comparison between manual and robotically assisted UKAs. METHODS: The trial design was a prospective, randomized, parallel, single-centre study comparing surgical alignment in patients undergoing UKA for the treatment of medial compartment osteoarthritis (ISRCTN77119437). Participants underwent surgery using either robotic arm-assisted surgery or conventional manual instrumentation. The primary outcome measure (surgical accuracy) has previously been reported, and, along with secondary outcomes, were collected at one-, two-, and five-year timepoints. Analysis of five-year results and longitudinal analysis for all timepoints was performed to compare the two groups. RESULTS: Overall, 104 (80%) patients of the original 130 who received surgery were available at five years (55 robotic, 49 manual). Both procedures reported successful results over all outcomes. At five years, there were no statistical differences between the groups in any of the patient reported or clinical outcomes. There was a lower reintervention rate in the robotic arm-assisted group with 0% requiring further surgery compared with six (9%) of the manual group requiring additional surgical intervention (p < 0.001). CONCLUSION: This study has shown excellent clinical outcomes in both groups with no statistical or clinical differences in the patient-reported outcome measures. The notable difference was the lower reintervention rate at five years for roboticarm-assisted UKA when compared with a manual approach. Cite this article: Bone Joint J 2021;103-B(6):1088-1095.

Robotic arm-assisted bi-unicompartmental knee arthroplasty maintains natural knee joint anatomy compared with total knee arthroplasty: a prospective randomized controlled trial.

AIMS: The aim of this study was to compare robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) in order to determine the changes in the anatomy of the knee and alignment of the lower limb following surgery. METHODS: An analysis of 38 patients who underwent TKA and 32 who underwent bi-UKA was performed as a secondary study from a prospective, single-centre, randomized controlled trial. CT imaging was used to measure coronal, sagittal, and axial alignment of the knee preoperatively and at three months postoperatively to determine changes in anatomy that had occurred as a result of the surgery. The hip-knee-ankle angle (HKAA) was also measured to identify any differences between the two groups. RESULTS: The pre- to postoperative changes in joint anatomy were significantly less in patients undergoing bi-UKA in all three planes in both the femur and tibia, except for femoral sagittal component orientation in which there was no difference. Overall, for the six parameters of alignment (three femoral and three tibial), 47% of bi-UKAs and 24% TKAs had a change of < 2° (p = 0.045). The change in HKAA towards neutral in varus and valgus knees was significantly less in patients undergoing bi-UKA compared with those undergoing TKA (p < 0.001). Alignment was neutral in those undergoing TKA (mean 179.5° (SD 3.2°)) while those undergoing bi-UKA had mild residual varus or valgus alignment (mean 177.8° (SD 3.4°)) (p < 0.001). CONCLUSION: Robotic-assisted, cruciate-sparing bi-UKA maintains the natural anatomy of the knee in the coronal, sagittal, and axial planes better, and may therefore preserve normal joint kinematics, compared with a mechanically aligned TKA. This includes preservation of coronal joint line obliquity. HKAA alignment was corrected towards neutral significantly less in patients undergoing bi-UKA, which may represent restoration of the pre-disease constitutional alignment (p < 0.001). Cite this article: Bone Joint J 2020;102-B(11):1511-1518.

Free vascularised medial femoral condyle periosteal flaps in recalcitrant long bone non-union: a systematic review.

INTRODUCTION: In adults, treatment of recalcitrant long bone non-union is extremely challenging, with poorly vascularised and atrophic defects unresponsive to standard non-vascularised bone graft treatment. Recent studies have documented the use of free vascularised periosteal flaps to achieve union in refractory long bone fracture non-union, yet its use is not well established. This systematic review aims to assess the evidence for free vascularised periosteal flaps in recalcitrant long bone non-union. MATERIALS AND METHODS: The MEDLINE®/PubMed® and Embase databases were searched for the Medical Subject Heading (MeSH) terms periosteal flap/vascularised flap/long bone/non-union/non united fracture in accordance with the PRISMA guidelines. Bibliographies were scrutinised for additional articles. RESULTS: Pooled data from 14 studies met the inclusions criteria, comprising 137 cases of non-union, with 117 relating to long bone non-union. Pooled data indicated an overall 99% (116/117) successful union rate. All studies were of mid- to low-level evidence (Level III, IV and V). Only one study directly compared vascularised periosteal flaps to non-vascularised bone grafts, showing union rates of 100% versus 80% and faster time to union (2 versus 5.5 months). CONCLUSIONS: Free vascularised periosteal flaps are promising with pooled data showing a 99% success rate in achieving union in refractory long bone non-union. This compares favourably with standard orthopaedic care consisting of revision fixation and non-vascularised bone graft union rates of approximately 80%. However, study design flaws should be addressed by validated outcome measures plus adequate blinding, and further comparative studies with greater patient numbers are required.

Robotic-Arm-Assisted vs Conventional Unicompartmental Knee Arthroplasty. The 2-Year Clinical Outcomes of a Randomized Controlled Trial.

BACKGROUND: Unicompartmental knee arthroplasty (UKA) for treatment of medial compartment osteoarthritis has potential benefits over total knee arthroplasty but UKA has a higher revision rate. Robotic-assisted UKA is increasingly common and offers more accurate implant positioning and limb alignment, lower early postoperative pain but evidence of functional outcome is lacking. The aim was to assess the clinical outcomes of a single-centre, prospective, randomised controlled trial, comparing robotic-arm-assisted UKA with conventional surgery. METHODS: A total of 139 participants were recruited and underwent robotic-arm-assisted (fixed bearing) or conventional (mobile bearing) UKA. Fifty-eight patients in the robotic-arm-assisted group and 54 in the manual group at 2 years. The main outcome measures were the Oxford Knee Score, American Knee Society Score and revision rate. RESULTS: At 2 years, there were no significant differences for any of the outcome measures. Sub-group analysis (n = 35) of participants with a preoperative University of California Los Angeles Activity Scale >5 (more active) was performed. In this sub-group, the median Oxford Knee Score at 2 years was 46 (IQR 42.0-48.0) for robotic-arm-assisted and 41 (IQR 38.5-44.0) for the manual group (P = .036). The median American Knee Society Score was 193.5 (IQR 184.0-198.0) for the robotic-arm-assisted group and 174.0 (IQR 166.0-188.5) for the manual group (P = .017). Survivorship was 100% in robotic-arm-assisted group and 96.3% in the manual group. CONCLUSION: Overall, participants achieved an outcome equivalent to the most widely implanted UKA in the United Kingdom. Sub-group analysis suggests that more active patients may benefit from robotic-arm- assisted surgery. Long term follow-up is required to evaluate differences in survivorship.

A comparison of gait one year post operation in an RCT of robotic UKA versus traditional Oxford UKA.

Robot-assisted unicompartmental knee surgery has been shown to improve the accuracy of implant alignment. However, little research has been conducted to ascertain if this results in a measureable improvement in knee function post operatively and a more normal gait. The kinematics of 70 OA knees were assessed using motion analysis in an RCT (31 receiving robotic-assisted surgery, and 39 receiving traditional manual surgery) and compared to healthy knees. Statistically significant kinematic differences were seen between the two surgical groups from foot-strike to mid-stance. The robotic-assisted group achieved a higher knee excursion (18.0°, SD 4.9°) compared to the manual group (15.7°, SD 4.1°). There were no significant difference between the healthy group and the robotic assisted group, however there was a significant difference between the healthy group and the manual group (p < 0.001). Hence robotically-assisted knee replacement with Mako Restoris Implants appears to lead not only to better implant alignment but also some kinematic benefits to the user during gait.

Improved Accuracy of Component Positioning with Robotic-Assisted Unicompartmental Knee Arthroplasty: Data from a Prospective, Randomized Controlled Study.

BACKGROUND: Higher revision rates have been reported in patients who have undergone unicompartmental knee arthroplasty compared with patients who have undergone total knee arthroplasty, with poor component positioning identified as a factor in implant failure. A robotic-assisted surgical procedure has been proposed as a method of improving the accuracy of component implantation in arthroplasty. The aim of this prospective, randomized, single-blinded, controlled trial was to evaluate the accuracy of component positioning in unicompartmental knee arthroplasty comparing robotic-assisted and conventional implantation techniques. METHODS: One hundred and thirty-nine patients were randomly assigned to treatment with either a robotic-assisted surgical procedure using the MAKO Robotic Interactive Orthopaedic Arm (RIO) system or a conventional surgical procedure using the Oxford Phase-3 unicompartmental knee replacement with traditional instrumentation. A postoperative computed tomographic scan was performed at three months to assess the accuracy of the axial, coronal, and sagittal component positioning. RESULTS: Data were available for 120 patients, sixty-two who had undergone robotic-assisted unicompartmental knee arthroplasty and fifty-eight who had undergone conventional unicompartmental knee arthroplasty. Intraobserver agreement was good for all measured component parameters. The accuracy of component positioning was improved with the use of the robotic-assisted surgical procedure, with lower root mean square errors and significantly lower median errors in all component parameters (p < 0.01). The proportion of patients with component implantation within 2° of the target position was significantly greater in the group who underwent robotic-assisted unicompartmental knee arthroplasty compared with the group who underwent conventional unicompartmental knee arthroscopy with regard to the femoral component sagittal position (57% compared with 26%, p = 0.0008), femoral component coronal position (70% compared with 28%, p = 0.0001), femoral component axial position (53% compared with 31%, p = 0.0163), tibial component sagittal position (80% compared with 22%, p = 0.0001), and tibial component axial position (48% compared with 19%, p = 0.0009). CONCLUSIONS: Robotic-assisted surgical procedures with the use of the MAKO RIO lead to improved accuracy of implant positioning compared with conventional unicompartmental knee arthroplasty surgical techniques. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Diagnostic accuracy of the Thessaly test, standardised clinical history and other clinical examination tests (Apley's, McMurray's and joint line tenderness) for meniscal tears in comparison with magnetic resonance imaging diagnosis.

BACKGROUND: Reliable non-invasive diagnosis of meniscal tears is difficult. Magnetic resonance imaging (MRI) is often used but is expensive and incidental findings are problematic. There are a number of physical examination tests for the diagnosis of meniscal tears that are simple, cheap and non-invasive. OBJECTIVES: To determine the diagnostic accuracy of the Thessaly test and to determine if the Thessaly test (alone or in combination with other physical tests) can obviate the need for further investigation by MRI or arthroscopy for patients with a suspected meniscal tear. DESIGN: Single-centre prospective diagnostic accuracy study. SETTING: Although the study was performed in a secondary care setting, it was designed to replicate the results that would have been achieved in a primary care setting. PARTICIPANTS: Two cohorts of patients were recruited: patients with knee pathology (n = 292) and a control cohort with no knee pathology (n = 75). MAIN OUTCOME MEASURES: Sensitivity, specificity and diagnostic accuracy of the Thessaly test in determining the presence of meniscal tears. METHODS: Participants were assessed by both a primary care clinician and a musculoskeletal clinician. Both clinicians performed the Thessaly test, McMurray's test, Apley's test, joint line tenderness test and took a standardised clinical history from the patient. RESULTS: The Thessaly test had a sensitivity of 0.66, a specificity of 0.39 and a diagnostic accuracy of 54% when utilised by primary care clinicians. This compared with a sensitivity of 0.62, a specificity of 0.55 and diagnostic accuracy of 59% when used by musculoskeletal clinicians. The diagnostics accuracy of the other tests when used by primary care clinicians was 54% for McMurray's test, 53% for Apley's test, 54% for the joint line tenderness test and 55% for clinical history. For primary care clinicians, age and past history of osteoarthritis were both significant predictors of MRI diagnosis of meniscal tears. For musculoskeletal clinicians age and a positive diagnosis of meniscal tears on clinical history taking were significant predictors of MRI diagnosis. No physical tests were significant predictors of MRI diagnosis in our multivariate models. The specificity of MRI diagnosis was tested in subgroup of patients who went on to have a knee arthroscopy and was found to be low [0.53 (95% confidence interval 0.28 to 0.77)], although the sensitivity was 1.0. CONCLUSIONS: The Thessaly test was no better at diagnosing meniscal tears than other established physical tests. The sensitivity, specificity and diagnostic accuracy of all physical tests was too low to be of routine clinical value as an alternative to MRI. Caution needs to be exercised in the indiscriminate use of MRI scanning in the identification of meniscal tears in the diagnosis of the painful knee, due to the low specificity seen in the presence of concomitant knee pathology. Further research is required to determine the true diagnostic accuracy and cost-effectiveness of MRI for the detection of meniscal tears. TRIAL REGISTRATION: Current Controlled Trial ISRCTN43527822. FUNDING: The National Institute for Health Research Health Technology Assessment programme.

Ulna Nerve Decompression at the Elbow in Patients with Normal Nerve Conduction Tests.

BACKGROUND: Ulna nerve compression at the elbow is the second most common neuropathy of the upper limb. It has been suggested that nerve conduction tests are required to correctly make the diagnosis. The aim of this study was to assess whether patients with normal nerve conduction testing benefitted from surgical release of the ulna nerve. METHODS: 56 patients with symptoms of ulna nerve compression at the elbow were evaluated prospectively. All patients underwent electrophysiology testing followed by ulna nerve decompression irrespective of the results of the electrophysiology testing. Functional scores using the QuickDASH and PEM score were collected up to 12 months post-surgery. RESULTS: No difference was found between the group with normal and the group with abnormal electrophysiology studies. CONCLUSIONS: We conclude that patients who clinically have ulna nerve compression still benefit from ulna nerve decompression despite normal nerve conduction tests.

The thermal effects of lavage on 57 ox femoral heads prepared for hip resurfacing arthroplasty.

BACKGROUND AND PURPOSE: Previously, we have documented surface temperatures recorded by thermography great enough to cause osteonecrosis of the femoral head during hip resurfacing. We now performed an in vitro investigation with 3 questions: (1) whether water irrigation reduced bone surface temperature, (2) whether external bone temperatures were similar to core temperatures, and (3) whether blunting of the reamer affected temperature generation. METHODS: Using an ox-bone model, 57 femoral heads were peripherally reamed. The surface temperatures of bone were measured using a thermal camera and internal bone temperatures were measured using 2 theromocouples. We measured the effects of cooling with water at room temperature and with ice-cooled water. Progressive blunting of reamers was assessed over the 57 experiments. RESULTS: Mean and maximum temperatures generated during peripheral reaming were greater when no irrigation was used. Ice-cold saline protected femoral heads from thermal damage. External bone temperatures were much greater than internal temperatures, which were not sufficiently elevated to cause osteonecrosis regardless of lavage. Blunting of the reamer was not found to have a statistically significant effect in this study. INTERPRETATION: Cooling with ice-cooled water is recommended. Internal bone temperatures are not elevated despite the high surface temperatures reached during femoral head resurfacing.

Surgical approach and patient-reported outcomes after total hip replacement.

BACKGROUND: Previous research has mainly focused on how factors such as surgical approach might affect implant survivorship and the incidence of complications. Given the increasing interest in patient-reported outcomes, the purpose of this study is to explore whether surgical approach is associated with patient-reported pain, function, and satisfaction at 1-3 years after primary total hip replacement (THR). METHODS: Details of surgical factors were collated from operation notes for all consecutive patients at our centre from 2004-2006. All patients were mailed a questionnaire 1-3 years following surgery that collected WOMAC pain and function scores and the Self-Administered Patient Satisfaction Scale for Primary Hip and Knee Arthroplasty. Of the eligible 1,315 patients, 911 patients returned a completed questionnaire (69% response rate). Multivariable fractional logit models were used to identify whether surgical approach was associated with outcome scores. RESULTS: Surgical approach was found to be a significant predictor of patient-reported outcomes at 1-3 years after surgery, even after controlling for patient-specific factors. A posterior approach was associated with better scores on all three outcome measures. On average, predicted outcome scores for a typical patient with a posterior approach were between 3.5 and 7.2 percentage points higher than an equivalent patient with an anterolateral approach. INTERPRETATION: These findings suggest that clinical decisions concerning surgical approach may have an observable impact on patient-reported levels of pain, function, and satisfaction following THR.

Post-operative radiographic factors and patient-reported outcome after total hip replacement.

Although total hip replacement (THR) is considered a very successful surgical intervention, a proportion of patients experience persistent pain or disability, and/or dissatisfaction with the outcome of surgery. Our aim was to determine whether post-operative radiographic variables were predictive of patient-reported pain, function and satisfaction after primary THR. At 1-3 years after surgery patients completed the WOMAC Pain scale, WOMAC Function scale and a validated measure of satisfaction with the outcome of surgery. Post-operative radiographs taken prior to discharge were graded for the restoration of offset, restoration of leg length, anteroposterior (AP) alignment of the femoral stem and AP acetabular inclination. Binary logistic regression was used to identify whether radiographic variables were significant predictors of patient-reported outcome scores. Radiographic and patient-reported outcomes data were available for 452 THR patients. No radiographic predictors were found to be significant predictors of patient reported pain, function or satisfaction at 1-3 years after THR. This highlights that patients with continuing problems after THR may benefit from a thorough multidisciplinary assessment to diagnose the underlying cause of the problems.