TKA is among the fastest growing interventions in medicine, with procedure incidence increasing the most in younger patients. Global knee scores have a ceiling effect and do not capture the presence of difficulty or dissatisfaction with specific activities important to patients. We quantified the degree of residual symptoms and specific functional deficits in young patients who had undergone TKA. In a national multicenter study, we quantified the degree of residual symptoms and specific functional deficits in 661 young patients (mean age, 54 years; range, 19–60 years; 61% female) at 1 to 4 years after primary TKA. To eliminate observer bias, satisfaction and function data were collected by an independent, third-party survey center with expertise in administering medical outcomes questionnaires. Overall, 89% of patients were satisfied with their ability to perform normal daily living activities, and 91% were satisfied with their pain relief. After TKA, 66% of patients indicated their knees felt normal, 33% reported some degree of pain, 41% reported stiffness, 33% reported grinding/other noises, 33% reported swelling/tightness, 38% reported difficulty getting in and out of a car, 31% reported difficulty getting in and out of a chair, and 54% reported difficulty with stairs. After recovery, 47% reported complete absence of a limp and 50% had participated in their most preferred sport or recreational activity in the past 30 days. When interviewed by an independent third party, about 1/3 of young patients reported residual symptoms and limitations after modern TKA. We recommend informing patients considering surgery about the high likelihood of residual symptoms and limitations after contemporary TKA, even when performed by experienced surgeons in high-volume centers, and taking specific steps to set patients’ expectations to a level that is likely to be met by the procedure as it now is performed

The concept under discussion is curious and central to our work: is patient dissatisfaction with modern TKA really a “growing problem”? Could it be, that as our technique and technology have improved function and durability, that surgical results have become worse????. A disappointing percentage of patients polled from a distance are less than fully satisfied with the results of their surgery. Why does this surprise us as surgeons?. This problem needs to be untangled. First, these studies ask patients blankly if they are satisfied with their surgery, generally and with respect to specific criteria (e.g. activities of daily living). Neither the patients nor their radiographs have been evaluated. Undoubtedly, some dissatisfied patients will have arthroplasties that would be assessed as less than perfect by a comprehensive evaluation that might include stability testing, range of motion and radiographs of patellar tracking, including CT examination for rotational positioning of components. Some will have suffered the recognised complications of surgery such as chronic regional pain syndrome and infections which, while treated, often yield poor results. Surgeons all too often abandon a systematic and comprehensive evaluation, almost dismissing patients who complain. A second group will be disabled due to physical factors extrinsic to the arthroplasty: polyarthritis, deconditioning and medical comorbidities. Others suffer depression and are disappointed that life never improved after the arthroplasty. Thirdly, another group will have knees that could not technically have been any better, but who are still dissatisfied with the result. Some had expectations that exceeded the capability of current technology to reproduce knee function. Their surgeons failed to convey the potential of arthroplasty to make things “normal” in a way that the patient could incorporate. Other patients may have submitted to surgery prematurely, before arthritis and knee dysfunction, had reached the point where arthroplasty represents an improvement. The concept of a “growing problem”, has more to do with the disjunction between rapidly accelerating public expectations (fueled by modern medicine) and the more modest rate of progress in technology, technique and education. Happy patients tend to be satisfied and there are a great many factors that determine happiness. Assessment depends on tools for measurement. Surgeons have struggled honestly to develop tools that could help assess which prostheses and techniques were superior, to make wise choices in developing techniques and implants. Many of the original clinical assessment tools have been challenged as invalid. Newer more comprehensive tools have been developed. The “evidence based” movement, and rejection of some clinical tools, represents a shift in power in clinical medicine that has “enabled payers, purchasers, and governmental authorities to use their financial clout to alter the practice of medicine.” (. http://www.ahrq.gov/research/findings/evidence-based-reports/jhppl/rodwin.html. ). This information is a call for practitioners to evaluate dissatisfied individuals compassionately and objectively and for investigators to evaluate the entire problem exhaustively. Skepticism is appropriate when this message is a glib pretext for commercialisation and/or for denigration of the role of arthroplasty in the lives of our patients. It is a call to improve, not abandon our craft

Despite the widely accepted advantages of total knee arthroplasty surgery, not all patients are completely satisfied. This was initially reported with studies from the Swedish Registry and indicates room for improvement in our craft. But who says this is a “growing concern”? First of all are the third party payers and government agencies who would like to curtail expenditures and retain funds. Next are manufacturers promoting new, and one would hope, improved products and finally surgeons similarly promoting new techniques.

But who are the minority of dissatisfied patients and why are they unhappy? There is no reduction in demand for arthroplasty surgery by patients worldwide.

Abstract. Abstract:. Background. The dissatisfaction rate in patients operated with TKR is generally quoted to be around 20% in various registries in patients operated by multiple surgeons. The data of satisfaction rates following a TKR performed by single high volume surgeons is lacking. Aim. To study the satisfaction rate and Net Promoter Score (NPS) of consecutively operated TKR patients by a single surgeon with a minimum 1 year follow up. Methods. 860 out of 883 patients who were operated between 1st April, 2018 and 31st March, 2019 were contacted by a telephonic call. They were asked 3 questions related to their experience about the operation. The patient satisfaction, NPS and reason for dissatisfaction were assessed. Results. The overall satisfaction rate of 95.93% and a net promoter score of +96.63 was observed. When the NPS was calculated as the worst case scenario, a score of +93.70 was observed. 6 patients were unsatisfied with causes directly related to the surgery. Conclusion. TKR can have as high satisfaction rates with very high NPS in experienced surgical hands using standard techniques. These results may form a benchmark against which newer technologies can be compared

Aims. This study assesses patient barriers to successful telemedicine care in orthopaedic practices in a large academic practice in the COVID-19 era. Methods. In all, 381 patients scheduled for telemedicine visits with three orthopaedic surgeons in a large academic practice from 1 April 2020 to 12 June 2020 were asked to participate in a telephone survey using a standardized Institutional Review Board-approved script. An unsuccessful telemedicine visit was defined as patient-reported difficulty of use or reported dissatisfaction with teleconferencing. Patient barriers were defined as explicitly reported barriers of unsatisfactory visit using a process-based satisfaction metric. Statistical analyses were conducted using analysis of variances (ANOVAs), ranked ANOVAs, post-hoc pairwise testing, and chi-squared independent analysis with 95% confidence interval. Results. The survey response rate was 39.9% (n = 152). The mean age of patients was 51.1 years (17 to 85), and 55 patients (38%) were male. Of 146 respondents with completion of survey, 27 (18.5%) reported a barrier to completing their telemedicine visit. The majority of patients were satisfied with using telemedicine for their orthopaedic appointment (88.8%), and found the experience to be easy (86.6%). Patient-reported barriers included lack of proper equipment/internet connection (n = 13; 8.6%), scheduling difficulty (n = 2; 1.3%), difficulty following directions (n = 10; 6.6%), and patient-reported discomfort (n = 2; 1.3%). Barriers based on patient characteristics were age > 61 years, non-English primary language, inexperience with video conferencing, and unwillingness to try telemedicine prior to COVID-19. Conclusion. The barriers identified in this study could be used to screen patients who would potentially have an unsuccessful telemedicine visit, allowing practices to provide assistance to patients to reduce the risk of an unsuccessful visit. Cite this article: Bone Jt Open 2021;2(9):745–751

Total Knee Arthroplasty (TKA) is a successful treatment for end stage osteoarthritis of the knee joint. However, post-operative pain can lead to patient dissatisfaction and poorer outcomes. Cooled radiofrequency nerve ablation (CRNA) has reportedly been effective at treating pain osteoarthritic knee pain by targeting the periarticular nerves of the knee. We undertook a prospective, controlled pilot study to determine if CRNA provides effective post-operative analgesia when utilised intra-operatively during total knee arthroplasty. Participants were recruited from January 2019 to February 2020. Those meeting inclusion criteria underwent TKA with intraoperative CRNA to 6 target sites prior to the cementing of implants. The primary outcomes were pain scores and opiate usage in the first 4 days post-operatively, then weekly up to 6 weeks. A total of 62 patients were screened and allocated sequentially; 18 were recruited to the control group and 12 recruited to the study group. The two groups did not have any significant difference in demographics. There were no clinically significant differences between the two groups in terms of pain scores nor opiate usage. There were complications as a result of the intervention. This study demonstrated no benefit of using intraoperative CRNA for improving post-operative pain scores or reducing opiate use after TKA

The prevalence of gluteal tendinopathy (GT) associated with osteoarthritis of the hip is difficult to determine as it is frequently undiagnosed or misdiagnosed as trochanteric bursitis. Its relationship to total hip arthroplasty (THA) outcomes is currently unknown. The aim of this study was to determine the incidence of GT at the time of hip arthroplasty and examine the relationship between GT and patient reported outcomes (PROMS) before and after THA. Patients undergoing THA for primary osteoarthritis between August 2017 and August 2020 were recruited. Tendinopathy was assessed and graded at time of surgery. PROMS included the Oxford Hip Score (OHS), HOOS JR, EQ-5D, and were collected preoperatively and at one year after THA. Satisfaction with surgery was also assessed at 1 year. 797 patients met eligibility criteria and were graded as Grade 1: normal tendons (n =496, 62%), Grade 2: gluteal tendinopathy but no tear (n=222, 28%), Grade 3: partial/full thickness tears or bare trochanter (n=79, 10%). Patients with abnormal gluteal tendons were older (p=0.001), had a higher mean BMI (p=0.01), and were predominately female (p=0.001). Patients with higher grade tendinopathy had statistically significant inferior PROMS at one year, OHS score (44.1 v 42.9 v 41.3, p 0.001) HOOS JR (89.3 V 86.3 V 85.6 p 0.005). Increasing gluteal tendon grade was associated with a greater incidence of problems with mobility (p=0.001), usual activities (p=0.001) and pain (p=0.021) on EQ5D. There was a 3 times relative risk of overall dissatisfaction with THA in the presence of gluteal tears. This study demonstrated that gluteal tendinopathy was commonly observed and associated with inferior 1-year PROMS in patients undergoing THA for OA. Increasing degree of tendinopathy was a negative prognostic factor for worse functional outcomes and patient satisfaction

Anterior cruciate ligament (ACL) ruptures are debilitating injuries, often managed via ACL reconstruction (ACLR). Reduced range of motion (ROM), particularly loss of extension (LOE), is the most significant contributor to post-operative patient dissatisfaction. LOE may preclude return to sport, increase re-rupture rates and precipitate osteoarthritis. Passive LOE rates following ACLR have been reported at 15%. However, LOE incidence during active tasks are poorly characterised. Our review sought to determine knee extension angles for active tasks following an ACL injury or ACLR. We hypothesised greater incidences of active LOE following ACL injury or ACLR, compared to uninjured contralateral limbs or controls. We systematically searched MEDLINE, Embase, Cochrane Library, Scopus, SPORTDiscus, and relevant trials databases for English articles. Included were cohort, cross-sectional, case-controlled or randomised controlled trials analysing adults with ACL injury treated surgically or otherwise, with at least 12-weeks follow-up and reporting either active knee extension angle, active LOE angles or incidence of active knee LOE during functional tasks. The protocol was registered on PROSPERO (CRD42018092295). Subsequent meta-analysis was performed. After screening, 71 eligible articles were included. Studies were heterogenous in design and quality. Included tasks were overground walking (n=44), running (n=3), hopping/jumping/cutting (n=11) single-leg landing (n=7), and stair climbing (n=6). LOE incidence varied depending on functional activities (33.95-92.74%). LOE incidence did not vary depending on ACL status (67.26% vs. 65.90% vs. 62.57% for ACL intact, ACLD and ACLR, respectively). We observed no difference in active LOE incidence according to ACL status. Importantly, the observed incidence for active LOE was reliably higher than previously reported rates for passive measures. Given the discrepancy between active and passive LOE incidence, clinicians may advisably prioritise active ROM during ACL rehabilitation

Traditional socket prosthesis (TSP) rehabilitation for amputees is associated with substantial dissatisfaction due to poor mobility and pain from soft tissue squeezing. Osseointegration (OI), eliminates skin compression and prosthesis fit issues, providing superior mobility and quality of life (QOL) for most amputees. The potential for OI to benefit patients with exceptionally poor mobility is understudied. To address this knowledge gap, this project investigated the mobility and QOL changes. A retrospective review was performed to identify transfemoral amputees who presented with wheelchair-bound mobility (K0) and had at least five years of post-osseointegration follow-up. Outcome measures included changes in mobility (K-level, daily prosthesis wear hours, Timed Up and Go (TUG), 6 minute walk test (6MWT)) and QOL (Questionnaire for persons with a Transfemoral Amputation (QTFA); Short Form Health Survey 36 (SF36). Adverse events recorded included debridement for infection, implant revision surgery, fractures, and implant failures. 9 patients with mean age 48.2±7.7 (range 34-59) years were included. The proportion of patients achieving K-level >2 improved from 0/9=0% to [9/9=100%], p<0.001. The 6MWT improved from 0±0 to 320.65±57 meters (p<0.001). The TUG improved from incapable to 10.68±2.7 seconds (p<0.001). Statistically significant QOL metrics included QTFA global score (33.33±31 vs 68.52±21, p=0.039), SF36 physical component score (30.03±6.3 vs 42.34±12, p=0.023) and the SF36 mental component score (47.89±8.8 vs 51.95±10.4, p=0.332). Six patients required operative intervention to address complications. Five developed infections: three had debridement, and 2 required implant removal and reimplantation. Osseointegration does confer significant sustained mobility and quality of life improvement for wheelchair bound transfemoral amputees. All 9 K0 patients had statistically improved mobility and QOL after osseointegrated reconstruction. This supports osseointegration as an effective rapid and long-term rehabilitation alternative for patients who have the neurologic and muscular capacity to walk but are unable due to issues related to their TSP

Despite total knee arthroplasty demonstrating high levels of success, 20% of patients report dissatisfaction with their result. Wellness Stasis Socks are embedded with a proprietary pattern of neuro-receptor activation points that have been proven to activate a precise neuro-response, as according to the pattern theory of haptic perception, which stimulates improvements in pain and function. Technologies that manipulate this sensory environment, such as textured insoles, have proven to be effective in improving gait patterns in patients with knee osteoarthritis. In regard to patients undergoing TKA using this new technology may prove beneficial as an adjunct to recovery as many patients suffer from further deficits to their proprioceptive system caused by ligamentous damage and alterations to mechanoreceptors during procedure. We hypothesized that the Wellness Stasis Socks are a safe, cost-effective and easily scalable strategy to support TKA patients through their recovery. Double-blinded, placebo-controlled randomized trial. Randomization using a computer-generated program . All study coordinators, healthcare personel and patients were blinded to patient groups. All surgical procedures were conducted by the same technique and orthopaedic surgeon. Intervention group: Wellness Stasis socks containing receptor point-activation technology. Control group: indentical appearing Wellness Stasis socks without receptor point-activation technology. Sock use during the waking hours . All additional post-operative protocols remained consistent between groups including same facility physiotherapy . Additional modalities (ice machines, soft-tissue massages, acupuncture) were prohibited. WOMAC questionnaire completed at baseline, 2 weeks, and 6 weeks to assess pain, stiffness and physical function. G. *. Power software to determine minimum sample of 50 in each group. No patients were lost to follow up and all followed study protocol. Data analysis using SPSS software. P-values, effect sizes, and confidence intervals are reported to assess clinical relevance of the finding. Physical status classifications were compared using t-test. Within-subject and between-subject differences in the mean WOMAC were analyzed by ANOVA. Cramer's V statistical analysis noted that other variables of Sex, BMI, ASA classification and Age were not statistically different between the control and intervention groups. No statistical difference between groups in Preop Womac scores. The data showed a consistent improvement in Womac scores for pain and stiffness at 2 weeks post op in the interventional group over the control group. The womac scores assessing physical function showed a consistent improvement at both 2 and 6 weeks post op in the intervention group compared to the control group. There were no complications in either group associated the sock use. The intervention proved to be a low cost and safe additional intervention post operatively from TKA to help patients improve with regard to pain, stiffness and physical function. This study suggests this modality can be added to the list of other commonly used post op interventions such as cryocuffs, physiotherapy, and relaxation techniques as safe post op interventions to help patients improve post op TKA and can act as an adjunct in providing non narcotic pain control

Introduction. Osseointegration is a potential treatment option for transfemoral amputees experiencing socket related problems. Till this date, there is little data assessing the feasibility and advantages of osseointegration in individuals with transtibial amputations. Materials and Methods. We prospectively followed 91 patients undergoing transtibial osseointegration from 2014–2018 who either 1) reported pain or mobility dissatisfaction with socket prosthesis; 2) had an intact limb with incapacitating pain, complex deformity, or profound distal weakness or 3) were recent amputees preferring osseointegration. Adverse events were monitored including infection, periprosthetic fracture, implant breakage, aseptic loosening, revision surgery/additional amputation and death. Functional outcomes were measured using the Questionnaire of persons with a Trans-femoral amputation (Q-TFA) and mobility was assessed using Six Minute Walk Test (6MWT) and Time Up and Go (TUG). Results. Following osseointegration surgery, there was a significant increase in the Q-TFA global score, the 6MWT and the K-levels during follow-up. At one year following Osseointegration surgery, all patients were pain-free, the 11 patients who were wheelchair-bound prior to surgery were ambulatory, and the other 27 patient unable to walk prior to surgery, demonstrated improved mobility. There were 7 cases of implant removals due to pain and loosening and 10 cases of revisions within an average of 1.8 years, of which 1 was aseptic loosening, 6 due to infection, 1 failure to integrate and 2 implant fractures. No periprosthetic bone fractures occurred. Conclusions. Transtibial osseointegration results in improved functional outcomes after amputation. Complications are manageable and should decrease with surgical and implant improvements

Up to 20 percent of patients remain dissatisfied after primary total knee arthroplasty (TKA) surgery. Understanding the reasons for dissatisfaction post TKA may allow for better patient selection and optimized treatment for those who remain dissatisfied. The association between function, mobility and satisfaction are not well understood. The purpose of this study was to investigate the association between post-TKA satisfaction and i) pre-operative, ii) post-operative, and iii) change in knee joint function during gait. Thirty-one patients scheduled to receive primary TKA for knee osteoarthritis (OA) diagnosis were recruited and visited the Dynamics of Human Motion laboratory for instrumented walking gait analysis (using a synchronized NDI Optotrak motion capture system and AMTI force platforms in the walkway) at two time points, first within the week prior to their surgery, and second at approximately one year after surgery. At their post-operative visit, patients were asked to indicate their satisfaction with their knee prosthesis on a scale from zero to 100, with zero being totally unsatisfied and 100 being completely satisfied. Knee joint mechanics during gait at both time points were characterized by discriminant scores, the projection of their three-dimensional knee angles and moments during gait onto an existing discriminant model that was created to optimize separation of severe knee OA and healthy asymptomatic gait patterns. This discriminant model was created using data from 73 healthy participants and 73 with severe knee OA, and includes the magnitude and pattern features (captured with principal component analysis) of the knee adduction and flexion moment, and the magnitude of the knee flexion angle during gait. Larger discriminant scores indicate improved function toward healthy patterns, and smaller scores indicate more severe function. Associations between post-operative satisfaction and pre, post and change in discriminant scores were examined using Pearson correlation analyses. We also examined associations between satisfaction and pre-operative BMI, EQ5D and Oxford 12 scores, as well as changes in these scores from pre to post-TKA. Discriminant scores representing knee joint function during gait significantly improved on average after surgery (P =0.05). While overall knee joint function improved after primary TKA surgery, the amount of improvement in function was not reflected in post-operative patient satisfaction. However, the pre-operative function of the patient was negatively associated with satisfaction, indicating that patients with higher pre-operative function are overall less satisfied with their TKA surgery, regardless of any functional improvement due to the surgery. Interestingly, the only significant association with post-operative satisfaction was knee joint function, and the relationship between function and patient satisfaction following TKA appears to relate only to the baseline functional state of the patient, and not with functional improvement. This suggests that dissatisfaction post-surgery is more likely reflecting the unmet expectations of a higher functioning patient, and has implications for the need for improved understanding of pre-operative patient functional variability in TKA triage and expectation management

Background. The literature quotes up to 20% dissatisfaction rates for total knee replacements (TKR). Swedish registry and national joint registry of England and Wales confirm this with high volumes of patients included. This dissatisfaction rate is used as a basis for improving/changing/modernising knee implant designs by major companies across the world. Aim. We aimed to compare post TKR satisfaction rates for navigated and non navigated knees. Methods. This was a retrospective analysis of prospectively collected data. All patients undergo comprehensive preoperative evaluation and comprehensive consent process and same rehabilitation protocols are followed as standard practice. Two groups were established depending on whether surgery was performed with or without computer navigation. We included 229 patients in each group. There were nine bilateral cases in the navigated group giving a total of 238 knees. Both groups were similar at the time of surgery (navigated: 68 years (sd9);; BMI 32.46;; (sd5.19);; OKS: 42.2 (sd7.5);; non-navigated: 70 years (sd9);; BMI 32.36;; (sd5.26);; OKS: 42.4 (sd7.3)). The satisfaction rates are recorded as very satisfied, satisfied, unsure or dissatisfied. Results. Of the 238 navigated knees 227 (95.4%) were very satisfied or satisfied;; while of the 229 non-navigated knees 205 (89.5%) were very satisfied or satisfied. Only 3 (1.3%) navigated knees and 9 (3.9%) non-navigated knees were dissatisfied. Seven (2.9%) navigated knees and fifteen (6.6%) non-navigated knees were unsure. The navigated group showed better satisfaction (p=0.049) compared to the non-navigated group and better satisfaction than previously published satisfaction rates [3]. When combining dissatisfaction and unsure responses the navigated group again performed significantly better than the non-navigated group (p=0.021). Satisfaction rates were also compared with published literature, which suggest that 82–89% of TKA patients are satisfied and that navigation has no effect on satisfaction [3]. Our data for the non-navigated knees are similar to high end of the published data. This goes to show that comprehensive education of patients, high volume surgeons and elective arthroplasty unit along with comprehensive consent process can achieve best results. We have also shown that navigation influences satisfaction rates. There were no differences in 6 week OKS data with scores of 28.1 (sd= 8.0) and 28.8 (sd=7.8) for navigated and non-navigated groups(p=0.623), The same was also true for range of flexion/extension (92.1° [sd=13.4°& 91.3° [sd=14.1°, p=0.360) and length of hospital stay in days (median=5 [min=2, max=37], median=5 [min=2, max=19], p=0.959);; for navigated and non-navigated groups respectively. Of those navigated knees reported as ‘dissatisfied’ and ‘unsure’, 50.0% (5 knees) were due to pain in the knee. For non-navigated knees, 66.7% (16 knees) stated knee pain as the reason for being ‘dissatisfied’ or ‘unsure’. Conclusion. A modern elective arthroplasty service can deliver high satisfaction rates. Use of computer navigation further improves even the best conventional satisfaction rates. Industry should promote better surgical techniques rather than bringing out new implants to improve satisfaction rates in total knee replacements

In years past, the most common reason for revision following knee replacement was polyethylene wear. A more recent study indicates that polyethylene wear is relatively uncommon as a cause for total knee revision counting for only 10% or fewer of revisions. The most common reason for revision currently is aseptic loosening followed closely by instability and infection. The time to revision was surprisingly short. In a recent series only 30% of knees were greater than 5 years from surgery at the time of revision. The most common time interval was less than 2 years. This is likely because of the higher incidence of infection and instability that occurs most commonly at a relatively early time frame. Evaluation of a painful total knee should take into account these findings. All total knees that are painful within 5 years of surgery should be assumed to be infected until proven otherwise. Therefore, virtually all should be aspirated for cell count, differential, and culture. Alpha-defensin is also available in cases in which a patient may have been on antibiotics within a month or less, as well as cases in which diagnosis is a challenge for some reason. Instability can be diagnosed with physical exam focusing on mid-flexion instability which can be usually determined with the patient seated and the knee in mid-flexion, with the foot flat on the floor at which point sagittal plane laxity can be discerned. This is also frequently associated with symptoms of giving way and recurring effusions and difficulty descending stairs. A new phenomenon of tibial de-bonding has been described, which can be a challenge to diagnose. Radiographs can appear normal when loosening occurs between the implant and the cement mantle. This seems to be more common with the use of higher viscosity cement. Obviously this is technique dependent since good results have been reported with the use of high viscosity cement. Component malposition can cause stiffness and pain and relatively good results have been reported by component revision when malrotation has been confirmed with CT scan. When infection, instability and loosening are not present, extra-articular causes should be ruled out including lumbar spine, vascular compromise, complex regional pain syndromes and fibromyalgia, and peri-articular causes such as bursitis, tendonitis, tendon impingement among others. One of the most common causes of pain following total knee is unrealistic patient expectations. Performing total knee replacement in early stages of arthritis with only mild to moderate symptoms and radiographic changes has been associated with persistent pain and dissatisfaction. It may be prudent to obtain the immediate preoperative x-rays to determine if early intervention was undertaken and patients have otherwise normal appearing total knee x-rays and a negative work up. A recent study indicated that this was likely a cause or a major contributing factor to persistent pain following otherwise a well performed knee replacement. A national multicenter study of the appropriateness of indications for TKA also indicated that early intervention was a major cause of persistent pain, dissatisfaction, and failure to improve following total knee replacement

Introduction. The patella experiences large forces and variable kinematic patterns throughout flexion which could influence function and patient satisfaction after a total knee arthroplasty (TKA). Therefore, the objective of this study is to analyze in vivo patellar mechanism forces and kinematics throughout flexion to determine influencing factors that may lead to patient dissatisfaction. Methods. Fifty subjects were evaluated in this study, 40 having a Journey II bi-cruciate stabilized (BCS) TKA and 10 having normal, healthy knees. Similar demographics were controlled for each group. Each subject performed a deep knee bend. Kinematics were evaluated using a validated 3D-to-2D fluoroscopic technique while forces were determined using a validated inverse mathematical knee model. A two-tailed t-test was used to evaluate statistical significance. Results. Subjects averaged 2.96 ± 0.30 xBW and 2.82 ± 0.27 xBW of maximum femorotibial contact forces, 4.07 ± 0.39 xBW and 3.30 ± 0.55 xBW of maximum quadriceps forces, and 4.20 ± 0.94 xBW and 3.94 ± 0.67 xBW of maximum patellofemoral forces for the BCS and normal groups, respectively. Therefore, the TKA subjects in this study experienced larger, but similar forces compared to the normal subjects. For both groups, lateral condylar rollback was correlated with both femorotibial contact forces (p<0.0001) and quadriceps forces (p<0.0002). Higher patellotibial tilt was correlated with lower patellofemoral contact forces (p=0.0294). Conclusion. Most TKAs resect the ACL and only substitute for the PCL in PS TKAs, but BCS subjects may receive an advantage for ACL substitution as they experienced normal-like kinematic and kinetic patterns. The lone exception seems to be the quadriceps forces which were higher in the BCS TKA group. This could be influenced by femoral condylar shape, leading to earlier quadriceps wrapping

Introduction. Total knee arthroplasty (TKA) is a well proven surgical procedure. Squat and gait motions are common activities in daily life. However, squat motion is known as most dissatisfying motion in activities in daily life after total knee arthroplasty (TKA). Dissatisfaction after TKA might refer to muscle co-contraction between quadriceps and hamstrings. The purposed of this study was to develop squat and gait simulation model and analyses the contact mechanics and quadriceps and hamstring muscle stability. We hypothesized that squat model shows larger contact forces and lower hamstring to quadriceps force ratio than gait model. Materials and Methods. Squat motion and gait model were simulated in musculoskeletal simulation software (AnyBody Modeling System, AnyBody Technology, Denmark). Subject-specific bone models used in the simulation were reconstructed from CT images by Mimics (Materialize, Belgium). The lower extremity model was constructed with pelvis, femur, tibia, foot segments and total knee replacement components: femoral component, tibial insert, tibial tray, and patella component [Fig.1]. The muscle model was consisted of 160 muscle elements. The TKR components used in this study are PS-type LOSPA Primary Knee System (Corentec Co., Ltd, Republic of Korea). Force-dependent kinematics method was used in the simulation. The model was simulated to squat from 15° to 100° knee flexion, in 100 frames. Gait simulation model was based on motion capture and force-plate system. Motion capture and force-plate data were from grand challenge competition dataset. Results / Discussion. Patellofemoral contact forces ranged from 0.18 to 3.78 percent body weight (%BW) and from 0.00 to 1.36 %BW during squat motion and gait cycle, respectively. Patellofemoral contact forces calculated at 30°, 60°, and 90° flexion during squat motion were 0.53, 1.93, and 3.22 %BW, respectively. Wallace et al. also reported patellofemoral contact forces at 30°, 60°, and 90° flexion, which were 0.31, 1.33, 2.45 %BW during squat motion. Our results showed similar results from other studies, however the squat model overestimated the patellofemoral contact forces. Contact stiffness in the simulation model might affected the overestimated contact forces. Hamstring to quadriceps force ratio ranged from 0.32 to 1.88 for squat model, and from 0.00 to 2.54 for gait model. As our hypothesis, squat motion showed larger patellofemoral contact forces. Also, mean hamstring to quadriceps force ratio of squat model were about half than the mean hamstring to quadriceps force ratio of gait model. From the results, possibility exists that unbalanced force of quadriceps and hamstring can affect dissatisfaction after TKA while squat motion is the most dissatisfying motion after TKA. However, muscle stability is not the only factor that can affect dissatisfaction after TKA. In future study, more biomechanical parameters should be evaluated to find meaningful dissatisfying factor after TKA. Conclusion. In conclusion, TKA musculoskeletal models of squat and gait motion were constructed and patellofemoral contact force / hamstring to quadriceps force ratio were evaluated. Patellofemoral mechanics were validated by comparison of previous study. Additional studies are needed to find dissatisfying factor after TKA

Introduction. Functional deficits persist in a significant percentage of total hip arthroplasties (THA), leading to patient dissatisfaction. Spinal stenosis is a leading cause of chronic disability and lower extremity weakness. Although previous studies have evaluated the potential benefit of THA on back pain, none have reported the effects of spine disability on functional outcomes and patient satisfaction with THA. Methods. 244 primary THAs (233 patients) with minimum 2-year follow-up rated their satisfaction, return to activity, and standard hip outcomes using the Oxford Hip Score (OHS). History of lumbar spine pain, lumbar surgery, and daily activity limitations was documented and an Oswestry Disability Index (ODI) score was calculated. Results. 151 of 244 (62%) patients reported a history of back problems: 35 patients (14%) – history of lumbar surgery, 91 (37%) – daily low back pain, and 97 (40%) – back pain that limited activity. Patients with a history of back problems had lower OHS scores than those without, p=0.0001. Pain relief was reported by 93% versus resumption of activities in 82% of THA patients, p=0.025. Increasing spine disability, as determined by ODI, correlated with poor OHS, p<0.0001. Spine disability (ODI) was directly associated with patient dissatisfaction for pain relief (R=0.41, p<0.0001), return to activity (R=0.34, p<0.0001), and overall surgical results (ODI, R=0.38, p<0.0001) at 2 years after THA. Patient age, gender, and BMI were not associated with poor THA outcomes. Conclusions. The majority of THA patients have a history of lumbar spine problems. The Oswestry Spine Disability Index, which is the primary outcome measure of spinal disorders, correlated strongly with poor THA outcomes. Moderate and severe lumbar spine disability directly correlated with worse Oxford Hip Scores. Spine disability was directly associated with THA dissatisfaction

Background. Artificial total knee designs have revolutionized over time, yet 20% of the population still report dissatisfaction. The standard implants fail to replicate native knee kinematic functionality due to mismatch of condylar surfaces and non-anatomically placed implantation. (Daggett et al 2016; Saigo et al 2017). It is essential that the implant surface matches the native knee to prevent Instability and soft tissue impingement. Our goal is to use computational modeling to determine the ideal shapes and orientations of anatomically-shaped components and test the accuracy of fit of component surfaces. Methods. One hundred MRI scans of knees with early osteoarthritis were obtained from the NIH Osteoarthritis Initiative, converted into 3D meshes, and aligned via an anatomic coordinate system algorithm. Geomagic Design X software was used to determine the average anterior-posterior (AP) length. Each knee was then scaled in three dimensions to match the average AP length. Geomagic's least-squares algorithm was used to create an average surface model. This method was validated by generating a statistical shaped model using principal component analysis (PCA) to compare to the least square's method. The averaged knee surface was used to design component system sizing schemes of 1, 3, 5, and 7 (fig 1). A further fifty arthritic knees were modeled to test the accuracy of fit for all component sizing schemes. Standard deviation maps were created using Geomagic to analyze the error of fit of the implant surface compared to the native femur surface. Results. The average shape model derived from Principal Component Analysis had a discrepancy of 0.01mm and a standard deviation of 0.05mm when compared to Geomagic least squares. The bearing surfaces showed a very close fit within both models with minimal errors at the sides of the epicondylar line (fig 2). The surface components were lined up posteriorly and distally on the 50 femurs. Statistical Analysis of the mesh deviation maps between the femoral condylar surface and the components showed a decrease in deviation with a larger number of sizes reducing from 1.5 mm for a 1-size system to 0.88 mm for a 7-size system (table 1). The femoral components of a 5 or 7-size system showed the best fit less than 1mm. The main mismatch was on the superior patella flange, with maximum projection or undercut of 2 millimeters. Discussion and Conclusion. The study showed an approach to total knee design and technique for a more accurate reproduction of a normal knee. A 5 to 7 size system was sufficient, but with two widths for each size to avoid overhang. Components based on the average anatomic shapes were an accurate fit on the bearing surfaces, but surgery to 1-millimeter accuracy was needed. The results showed that an accurate match of the femoral bearing surfaces could be achieved to better than 1 millimeter if the component geometry was based on that of the average femur. For any figures or tables, please contact the authors directly

It is a not so uncommon clinical scenario: well-fixed, well-aligned, balanced total knee arthroplasty with continued pain. However, radiographs also demonstrate an unresurfaced patella. The debate continues and the controversy remains as whether or not to routinely resurface the patella in total knee arthroplasty. In perhaps the most widely referenced article on the topic, the overall revision rates were no different between the resurfaced (9%) and the unresurfaced (12%) groups and thus their conclusion was that similar results can be obtained with and without resurfacing. However, a deeper look in to the data in this study shows that 4 times more knees in the unresurfaced group were revised for patellofemoral problems. A more recent study concluded that selectively not resurfacing the patella provided similar results when compared to routinely resurfacing. The study does emphasise however, that this conclusion depends greatly on femoral component design and operative diagnoses. This suggests that selective resurfacing with a so-called “patella friendly” femoral component in cases of tibio-femoral osteoarthritis, is a safe and effective strategy. Finally, registry data would support routine resurfacing with a 2.3 times higher relative risk of revision seen in the unresurfaced TKA. Regardless of which side of the debate one lies, the not so uncommon clinical scenario remains; what do we do with the painful TKA with an unresurfaced patella. Precise and accurate diagnosis of the etiology of a painful TKA can be very difficult, and there is likely a strong bias towards early revision with secondary patellar resurfacing in the painful TKA with an unresurfaced TKA. At first glance, secondary resurfacing is associated with relatively poor outcomes. Correia, et al. reported that only half the patients underwent revision TKA with secondary resurfacing had resolution of their complaints. Similarly, only 53% of patients in another series were satisfied with the procedure and pain relief. The conclusions that can be drawn from these studies and others are that either routine patellar resurfacing should be performed in all TKA or, perhaps more importantly, we need to better understand the etiology of pain in an otherwise well-aligned, well-balanced, well-fixed TKA. It is this author's contingency that the presence of an unresurfaced patella leads surgeons to reoperate earlier, without truly identifying the etiology of pain or dissatisfaction. This strong bias; basically there is something more that can be done, therefore we should do it, is the same bias that leads to early revision of partial knee arthroplasty. While very difficult, we as knee surgeons should not revise a partial knee or secondarily resurface a patella due to pain or dissatisfaction. Doing so, unfortunately, only works about half the time. The diagnostic algorithm for evaluating the painful, uresurfaced TKA includes routinely ruling out infection with serum markers and an aspiration. Pre-arthroplasty radiographs should be obtained to confirm suitability and severity of disease for an arthroplasty. An intra-articular diagnostic injection with Marcaine +/− corticosteroid should provide significant pain relief. MARS MRI may be beneficial to evaluate edema within the patella. Lastly, operative implant stickers to confirm implant manufacturer and type are critical as some implants perform less favorably with unresurfaced patellae. To date, no studies of secondary resurfacing describe the results of this, or similar, algorithms for defining patellofemoral problems in the unresurfaced TKA and therefore it is still difficult to conclude that poor results are not simply due to our inherent bias towards early revision and secondary resurfacing of the unresurfaced patella

Total knee arthroplasty is a successful procedure that reduces knee pain and improves function in most patients with knee osteoarthritis. Patient dissatisfaction however remains high, and along with implant longevity, may be affected by component positioning. Surgery in obese patients is more technically challenging with difficulty identifying appropriate landmarks for alignment and more difficult exposure of the joint. Patient specific instrumentation (PSI) has been introduced with the goal to increase accuracy of component positioning by custom fitting cutting guides to the patient using advanced imaging. A strong criticism of this new technology however, is the cost associated. The purpose of this study was to determine, using a prospective, randomized-controlled trial, the cost-effectiveness of PSI compared to standard instrumentation for total knee arthroplasty in an obese patient population. Patients with a body mass index greater than 30 with osteoarthritis and undergoing a primary total knee arthroplasty were included in this study. We randomized patients to have their procedure with either standard instrumentation (SOC) or PSI. At 12-weeks post-surgery patients completed a self-reported cost questionnaire and the Western Ontario and McMaster Osteoarthritis Index (WOMAC). We performed a cost-effectiveness analyses from a public health payer and societal perspective. As we do not know the true cost of the PSI instrumentation, we estimated a value of $100 for our base case analysis and used one-way sensitivity analyses to determine the effect of different values (ranging from $0 to $500) would have on our conclusions. A total of 173 patients were enrolled in the study with 86 patients randomized to the PSI group and 87 to the SOC group. We found the PSI group to be both less effective and more costly than SOC when using a public payer perspective, regardless of the cost of the PSI. From a societal perspective, PSI was both less costly, but also less effective, regardless of the cost of the PSI. The mean difference in effect between the two groups was −1.61 (95% CI −3.48, 026, p=0.091). The incremental cost-effectiveness ratio was $485.71 per point increase in the WOMAC, or $7285.58 per clinically meaningful difference (15 points) in the WOMAC. Overall, our results suggest that PSI is not cost-effective compared to standard of care from a public payer perspective. From a societal perspective, there is some question as to whether the decreased effect found with the PSI group is worth the reduced cost. The main driver of the cost difference appears to be time off of volunteer work, which will need to be investigated further. In future, we will continue to follow these patients out to one year to collect cost and effectiveness data to investigate whether these results remain past 12 weeks post-surgery