Forgotten Joint Research Articles

Early functional recovery outcomes and return to work after primary total hip arthroplasty: a novel patient reported outcomes questionnaire

PurposeClinical and patient reported outcomes are often collected before and after the procedure to benchmark and study outcomes for patients. These outcomes and scores are useful for tracking patient outcomes after surgery, however, the fact that these commonly used measures typically provide information about a patient’s level of pain and function at a single point in time is a limitation.MethodsWe present early functional recovery and return to work outcomes after primary THA from a novel questionnaire administered in a global, multi-center, prospective clinical study.ResultsBy 6 and 12 weeks post-op, a large proportion of study subjects were able to perform functional recovery outcomes after their THA: walk without an aid (74%; 94%); drive (76%; 97%); basic activities of daily living (94%; 99%); perform light household duties (91%; 96%); perform moderate-to-heavy household duties (54%; 86%); go up and down a flight of stairs (92%; 99%); put on socks/stockings (77%; 93%); bend down to pick up an object from the floor (87%; 97%); stand up from a chair (96%; 99%); perform leisure recreational activities (54%; 84%); perform primary goal identified pre-THA (69%; 86%). 60% were able to return to work by 12 weeks post-op. These questions showed strong association with the Forgotten Joint Score.ConclusionExcellent patient reported early functional recovery outcomes and satisfaction were observed at 6- and 12-weeks post-op in this cohort and is the first reported data using a novel PRO.Clinical trial registrationNCT03189303, registered June 14, 2017.

Increased medial talar tilt may incite ankle pain and predispose ankle osteoarthritis after correction of severity of knee varus deformity among patients undergoing bilateral total knee arthroplasty: a prospective observation

PurposePatients with varus knee osteoarthritis usually compensate at the ankle and typically walk with hindfoot valgus alignment. As the neutral weight-bearing axis of the lower limbs is restored with Total Knee Arthroplasty (TKA), ankle and hindfoot biomechanics also acutely change. This study aims to investigate whether any ankle clinical-radiographical changes occur as a result of bilateral mechanical TKA in patients with bilateral Osteoarthritis knee at a minimum follow-up of 6 months.MethodsThe prospective observational study included 61 patients (122 knees) undergoing simultaneous bilateral TKA (mechanical alignment). Tibio-talar angle(TTA), tibial Anterior Surface angle (TAS), lateral distal tibial angle (LDTA), talar-tilt angle (TT), anatomical talocrural angle (aTC), ground surface and distal tibial plafond angle (GP), ground surface and an upper surface of talus angle (GT)and tibial plateau and tibial plafond angle (PP) were measured on long-film radiographs to look for changes in the ankle, whereas functional assessment was done using American Foot and Ankle Society (AOFAS), Foot and Ankle Disability Index (FADI), and Forgotten Joint (FJS-12) scores. Patients were sub-grouped based on the Hip-Knee-Ankle (HKA) axis, and the effect of the severity of knee varus on the ankles after TKA was also analyzed. The minimum follow-up was 6 months.ResultsA significant decrease in the tibial plateau-tibial plafond (PP), ground-tibial plafond (GP), and ground-talar dome (GT) angles was noted after TKA (p-value < 0.05). Postoperative functional parameters were comparable to the preoperative status except for FADI, which significantly improved (p-value-0.03). Sub-group analysis based on the severity of knee varus (HKA) revealed GT to be most significantly reduced (p-value-0.036), while the talar tilt (TT) increased (p-value-0.044). Functional outcomes of the ankles clinically improved with the correction of severe knee varus after TKA. At a mean follow-up of 13.2 months post-TKA, 7 out of 61 (11.4%) patients complained of post-TKA ipsilateral ankle pain.ConclusionMechanically aligned bilateral TKA in severe varus deformity of the knee significantly decreases the GT angle but increases the varus tilt of the talus with lateral talar incongruency and under-coverage. Although the acute correction of severe knee varus deformity aligns the tibia more neutrally, resulting in an overall clinically evident improvement in ankle functional outcome, the increased varus talar tilt remains a deep concern.Level of EvidenceProspective, observational, comparative study Level II.

Why personalized surgery is the future of hip and knee arthroplasty: a statement from the Personalized Arthroplasty Society.

Although hip and knee joint replacements provide excellent clinical results, many patients still do not report the sensation and function of a natural joint. The perception that the joint is artificial may result from the anatomical modifications imposed by the surgical technique and the implant design. Moreover, the joint replacement material may not function similarly to human tissues. To restore native joint kinematics, function, and perception, three key elements play a role: (i) joint morphology (articular surface geometry, bony anatomy, etc.), (ii) lower limb anatomy (alignment, joint orientation), and (iii) soft tissue laxity/tension. To provide a 'forgotten joint' to most patients, it is becoming clear that personalizing joint replacement is the key solution. Performing a personalized joint replacement starts with patient selection and preoperative optimization, followed by using a surgical technique and implant design aimed at restoring the patient's native anatomy, creating optimal implant-to-bone stress transfer, restoring the joint's native articular range of motion without imposed limitations, macro- and micro-stability of the soft tissues, and a bearing whose wear resistance provides lifetime survivorship with unrestricted activities. In addition, the whole perioperative experience should follow enhanced recovery after surgery principles, favoring a rapid and complication-free recovery. As a new concept, some confusion may arise when applying these personalized surgery principles. Therefore, the Personalized Arthroplasty Society was created to help structure and accelerate the adoption of this paradigm change. This statement from the Society on personalized arthroplasty will serve as a reference that will evolve with time.

Image-based robotic-arm assisted unicompartmental knee arthroplasty provides high survival and good-to-excellent clinical outcomes at minimum 10years follow-up.

The purpose of the present study was to determine the incidence of revision and report on clinical outcomes at a minimum of 10years follow-up in patients who had received a medial unicompartmental knee arthroplasty (UKA) with an three-dimensional image-based robotic system. A total of 239 patients (247 knees), who underwent medial robotic-arm assisted (RA)-UKA at a single center between April 2011 and June 2013, were assessed. The mean age at surgery was 67.0years (SD 8.4). Post-operatively, patients were administered the Forgotten Joint Score-12 (FJS-12) and asked about their satisfaction (from 1 to 5). Post-operative complications were recorded. Failure mechanisms, revisions and reoperations were collected. Kaplan-Meier survival curves were calculated, considering revision as the event of interest. A total of 188 patients (196 knees) were assessed at a mean follow-up of 11.1years (SD 0.5, range 10.0-11.9), resulting in a 79.4% follow-up rate. Seven RA-UKA underwent revision, resulting in a survivorship rate of 96.4% (CI 94.6%-99.2%). Causes of revision included aseptic loosening (2 cases), infection (1 case), post-traumatic (1 case), and unexplained pain (3 cases). The mean FJS-12 and satisfaction were 82.2 (SD 23.9) and 4.4 (SD 0.9), respectively. Majority of cases (174/196, 88.8%) attained the Patient Acceptable Symptoms State (PASS, FJS-12 > 40.63). Male subjects had a higher probability of attaining a "forgotten joint" (p < 0.001) and high satisfaction (equal to 5, p < 0.05), when compared to females. Three-dimensional image-based RA-UKA demonstrated high implant survivorship and good-to-excellent clinical outcomes at minimum 10years follow-up. Pain of unknown origin represented the most common reason for RA-UKA revision. III.

Clinical utility of markerless motion capture for kinematic evaluation of sit-to-stand during 30 s-CST at one year post total knee arthroplasty: a retrospective study

BackgroundAlthough the importance of kinematic evaluation of the sit-to-stand (STS) test of total knee arthroplasty (TKA) patients is clear, there have been no reports analyzing STS during the 30-s chair sit-up test (30 s-CST) with a focus on kinematic characteristics. This study aimed to demonstrate the clinical utility of kinematic analysis of STS during the 30 s-CST by classifying STS into subgroups based on kinematic parameters, and to determine whether differences in movement strategies are expressed as differences in clinical outcomes.MethodsThe subjects were all patients who underwent unilateral TKA due to osteoarthritis of the knee and were followed up for one year postoperatively. Forty-eight kinematic parameters were calculated using markerless motion capture by cutting STS in the 30 s-CST. The principal components of the kinematic parameters were extracted and grouped by kinematic characteristics based on the principal component scores. Clinical significance was examined by testing whether differences in patient-reported outcome measures (PROMs) were observed.ResultsFive principal components were extracted from the 48 kinematic parameters of STS and classified into three subgroups (SGs) according to their kinematic characteristics. It was suggested that SG2, using a kinematic strategy similar to the momentum transfer strategy shown in previous studies, performed better in PROMs and, in particular, may be associated with achieving a “forgotten joint”, which is considered the ultimate goal after TKA.ConclusionsClinical outcomes differed according to kinematic strategies used STS, suggesting that kinematic analysis of STS in 30 s-CST may be useful in clinical practice.Trial registrationThis study was approved by the Medical Ethical Committee of the Tokyo Women’s Medical University (approval number: 5628 on May 21, 2021).

REMOTE EVALUATION OF POSTOPERATIVE OUTCOMES USING WEARABLE SENSORS COMPARING ROBOTIC-ASSISTED AND CONVENTIONAL KNEE ARTHROPLASTY

Patient-reported outcome measures (PROMs) have failed to highlight differences in function or outcome when comparing knee replacement designs and implantation techniques. Ankle-worn inertial measurement units (IMUs) can be used to remotely measure and monitor the bi-lateral impact load of patients, augmenting traditional PROMs with objective data. The aim of this study was to compare IMU-based impact loads with PROMs in patients who had undergone conventional total knee arthroplasty (TKA), unicompartmental knee arthroplasty (UKA), and robotic-assisted TKA (RA-TKA).77 patients undergoing primary knee arthroplasty (29 RA-TKA, 37 TKA, and 11 UKA) for osteoarthritis were prospectively enrolled. Remote patient monitoring was performed pre-operatively, then weekly from post-operative weeks two to six using ankle-worn IMUs and PROMs. IMU-based outcomes included: cumulative impact load, bone stimulus, and impact load asymmetry. PROMs scores included: Oxford Knee Score (OKS), EuroQol Five-dimension with EuroQol visual analogue scale, and the Forgotten Joint Score.On average, patients showed improved impact load asymmetry by 67% (p=0.001), bone stimulus by 41% (p&lt;0.001), and cumulative impact load by 121% (p=0.035) between post-operative week two and six. Differences in IMU-based outcomes were observed in the initial six weeks post-operatively between surgical procedures. The mean change scores for OKS were 7.5 (RA-TKA), 11.4 (TKA), and 11.2 (UKA) over the early post-operative period (p=0.144). Improvements in OKS were consistent with IMU outcomes in the RA-TKA group, however, conventional TKA and UKA groups did not reflect the same trend in improvement as OKS, demonstrating a functional decline.Our data illustrate that PROMs do not necessarily align with patient function, with some patients reporting good PROMs, yet show a decline in cumulative impact load or load asymmetry. These data also provide evidence for a difference in the functional outcome of TKA and UKA patients that might be overlooked by using PROMs alone.

Does acetabular robotic-assisted total hip arthroplasty with femoral navigation improve clinical outcomes at 1-year post-operative? A case-matched propensity score study comparing 98 robotic-assisted versus 98 manual implantation hip arthroplasties

IntroductionDespite the optimization of implant positioning, the clinical benefit of the use of robotic assistance during THA remains uncertain. In this case-control study (robotic versus manual technique) we made a retrospective short-term comparison of: (1) the functional results, (2) the complications, (3) and the influence of radiological symmetrization of the hips on the functional result. HypothesisThe use of a robotic arm improved the functional results of a THA. Materials and methodA retrospective case-control study was performed, including patients with unilateral hip osteoarthritis who underwent a robotic arm-assisted THA (THA-R). The controls (THA-C) were matched according to age, sex, body mass index and surgical approach. The Harris (HHS), Oxford (OHS) and Forgotten Joint (FJS) scores were collected preoperatively and 1 year postoperatively. At each review, complications were categorized into minor events, revision surgery with and without implant change. Radiographic analysis was performed on weight-bearing images of the pelvis 3 months postoperatively. The objective of the surgery was symmetrization of the THA in the contralateral healthy hip. For each measured parameter of the hip joint center of rotation (COR), global offset (GO) and articular leg length discrepancy (aLLD), the difference between the two sides corresponding to the delta symmetrization was compared. ResultsNinety-eight patients were included in the THA-R group and matched to 98 controls in the THA-C group. At 1 year postoperatively, the FJS and OHS scores were statistically higher in the THA-R group, respectively 82.1±22.3 [8.3; 100] and 40.8±8.8 [6; 48] vs. 71.2±27.8 [0; 100] and 38.1±9.7 [12; 48] in the THA-C group (p=0.004 and p=0.043). There was no difference in HHS (THA-R: 85.9±15.8 [31; 100] vs. THA-C: 85.8±13.3 [49–100] (p=0.962)). The implant revision rate at 1 year was significantly higher in the THA-C group (0% vs. 5.1% (p=0.025)). There was no difference in the reoperation without component exchange despite 3 dislocations (3.1%) in the THA-R group (5 (5.1%) vs. 9 (9.2%) (p=0.273)). The rate of abarticular pathologies (ilio-psoas irritation and greater trochanteric bursitis) was higher in the THA-C group (10 (10.8%) vs. 2 (2%) (p=0.016). Robotic acetabular assistance allowed a significantly better restitution of the horizontal position (THA-R: 1mm±4.8 [–11.7; 12.6] vs. THA-C: 4.1mm±7 [-29.6; 28] (p=0.0005)) and vertical COR (THA-R: 0.5mm±3.1 [–6; 8.3] vs. THA-C: 2mm±4.1 [–6; 14.6] (p=0.0068)). Navigated assistance of the femur did not significantly optimize the restitution of the Global Offset (THA-R: +2mm±6.4 [-16.4; 27.6] vs. THA-C: +0.5mm±7 .7 [–34; 30.2] (p=0.145)), or lower limb length (THA-R: +1.1mm±5 [–8.2; 13.5] vs. THA-C: +0.3mm±6 [-14.1; 22.5] (p=0.344). The FJS was statistically correlated with the restoration of the symmetry of the COR and the aLLD. A post-hoc power analysis confirmed sufficient potency (1-β=0.85). ConclusionRobotic acetabular assistance combined with femoral navigation improves clinical outcomes of THAs with fewer short-term complications. The precision of the positioning of the implants, optimized by the computer-assisted surgery system, is correlated with the missed joint score. Level of evidenceIII, retrospective case-control study.

High tibial osteotomy for medial meniscus posterior root tears in knees with moderate varus alignment can achieve favorable clinical outcomes

PurposeFavorable clinical results have been reported following high tibial osteotomy (HTO) for medial meniscus posterior root tear (MMPRT) in knees with varus alignment. However, the effect on the preoperative neutral alignment of the knee is not known. This study sought to evaluate the clinical outcomes of medial open-wedge HTO for MMPRT with neutral alignment.MethodsWe retrospectively reviewed 119 medial open-wedge HTOs and analyzed 22 knees with MMPRT. The knees were divided according to the preoperative hip-knee-ankle angle into a moderate varus alignment group (≤4° of varus alignment) and a varus alignment group (> 4° of varus alignment). The Knee Injury and Osteoarthritis Outcome Score (KOOS) and Forgotten Joint Score-12 (FJS-12) values were evaluated preoperatively and at the latest follow-up. The healing status of MMPRT at the time of second-look arthroscopy, performed at a mean of 15.4 ± 4.2 months, was compared with that after the primary HTO.ResultsThere were 11 knees in the moderate varus alignment group and 11 in the varus alignment group. In terms of perioperative patient-reported outcome measures, there was no significant difference in the preoperative or postoperative KOOS subscale score or FJS-12 score between the moderate varus and varus alignment groups. The healing rate was significantly higher in the moderate varus alignment group.ConclusionFavorable clinical results were obtained by medial open-wedge HTO in knees with MMPRT and moderate varus alignment in the short term. Surgeons should consider the indications for medial open-wedge HTO, even with moderate varus alignment, when planning treatment for MMPRT with persistent knee pain.Level of evidenceIV

Computer-Assisted Surgery Enables Beginner Surgeons, Under Expert Guidance, to Achieve Long-Term Clinical Results not Inferior to Those of a Skilled Surgeon in Knee Arthroplasty

PurposeThe purpose of this study is to determine whether the use of a surgical navigation system in total knee replacement (TKR) enables beginner and intermediate surgeons to achieve clinical PROM outcomes as good as those conducted by expert surgeons in the long term.MethodsWe enrolled 100 consecutive patients whose total navigated knee arthroplasty (TKA) was performed in our institution from 2008 to 2010. According to the principal surgeon's surgical experience, the patients were divided into three groups: (1) beginner surgeons, with no more than 30 previous knee replacement performances, (2) intermediate surgeons, with more than 30 but not more than 300, and (3) expert surgeons, with more than 300 knee replacements. Demographic data collected on the cohort included gender, laterality, age, and body mass index (BMI). The outcome measures assessed were Forgotten Joint Score (FJS), implant positioning, limb alignment, and prosthesis survival rate. A margin of equivalence of ± 18.5 points in the FJS scale was prespecified in terms of the minimal clinically important difference (MCID) to compare the FJS results obtained in the long period between the groups of interest.ResultsThe mean follow-up was 11.10 ± 0.78, 10.86 ± 0.66, and 11.30 ± 0.74 years, respectively, for each of the groups. The long-term FJS mean score was 80.86 ± 21.88, 81.36 ± 23.87, and 90.48 ± 14.65 for each group. The statistical analysis proved noninferiority and equivalence in terms of the FJS results reported in the long term by patients in Groups 1 or 2 compared to those in Group 3. More specifically, it has been proved that the mean difference between groups is within the interval of equivalence defined in terms of the MCID. The overall prostheses survival rate was 93.7%.ConclusionNavigated assisted TKA, under expert guidance, can be as effective when performed by beginner or intermediate surgeons as performed by senior surgeons regarding the accuracy of implant positioning, limb alignment, and long-term clinical outcome.

5-Year Survivorship and Outcomes of Robotic-Arm-Assisted Medial Unicompartmental Knee Arthroplasty.

Purpose While unicompartmental knee arthroplasty (UKA) has demonstrated benefits over total knee arthroplasty (TKA) in selected populations, component placement continues to be challenging with conventional surgical instruments, resulting in higher early failure rates. Robotic-arm-assisted UKA (RA-UKA) has shown to be successful in component positioning through preop planning and intraop adjustability. The purpose of this study is to assess the 5-year clinical outcomes of medial RA-UKA. Methods This study was a retrospective review of a single-center prospectively maintained cohort of 133 patients (146 knees) indicated for medial UKA from 2009 to 2013. Perioperative data and 2- and 5-year Knee injury Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster Universities Osteoarthritis Score (WOMAC), and Forgotten Joint Score (FJS) outcome measures were collected. Five-year follow-up was recorded in 119 patients (131 knees). Results Mean follow-up was 5.1 ± 0.2 years. Mean age and BMI were 68.0 ± 8.1 years and 29.3 ± 4.7 kg/m2, respectively. At 2-year follow-up, mean KOOS, WOMAC, and FJS were 71.5 ± 15.3, 14.3 ± 7.9, and 79.1 ± 25.8, respectively. At 5-year follow-up, mean KOOS, WOMAC, and FJS were 71.6 ± 15.2, 14.2 ± 7.9, and 80.9 ± 25.1, respectively. Mean change in KOOS and WOMAC was 34.6 ± 21.4 and 11.0 ± 13.6, respectively (p < 0.001 and p < 0.001). For patient satisfaction at last follow-up, 89% of patients were very satisfied/satisfied and 5% were dissatisfied. For patient activity expectations at last follow-up, 85% met activity expectations, 52% were more active than before, 25% have the same level of activity, 23% were less active than before, and 89% were walking without support. All patients returned to driving after surgery at a mean 15.2 ± 9.4 days. Survivorship was 95% (95% CI 0.91-0.98) at 5 years. One knee (1%) had a patellofemoral revision, two knees (1.3%) were revised to different partial knee replacements, and five knees (3.4%) were converted to TKA. Conclusion Overall, medial RA-UKA demonstrated improved patient-recorded outcomes, high patient satisfaction, met expectations, and excellent functional recovery. Midterm survivorship was excellent. Longitudinal follow-up is needed to evaluate long-term outcomes of robotic-arm-assisted UKA procedures.

Minimally invasive anterolateral approach versus direct anterior approach total hip arthroplasty in the supine position: a prospective study based on early postoperative outcomes

BackgroundMinimally anterolateral approach (MAA) and direct anterior approach (DAA) have been reported as beneficial for total hip arthroplasty (THA) due to their ability to reduce postoperative pain and lead to quicker rehabilitation by preserving muscle insertions. As there is an ongoing debate on the effect of these two approaches on early postoperative outcomes, this prospective study aimed to assess the difference in early clinical, radiological, and patient-reported outcomes between the two minimally invasive approaches.MethodsA total of 98 patients, 50 in the MAA group and 48 in the DAA group, were included in the study. Patients with complete data were evaluated preoperatively and postoperatively at 2, 6, and 12 weeks. Clinical measurements, including the ability to climb stairs and walk, 6-min walk test (6MWT), the Forgotten Joint Scale (FJS-12), Japanese Orthopedic Association (JOA) Hip scores, radiological evaluation, and complications were analyzed.ResultsThere were no significant differences in clinical outcomes and implant alignments between MAA and DAA groups. In regards to patient-reported outcomes, the FJS-12 was significantly higher in the MAA group compared to group DAA at 2 and 6 weeks postoperatively. However, there was no significant difference in the FJS-12 between the two groups 12 weeks after surgery. The differences also included shorter operative times (62.4 ± 9.05 min vs. 71 ± 8.01 min), less blood loss (132.6 ± 43.31 ml vs. 159.23 ± 37.25 ml), lower Hb drop (29.56 ± 8.02 g/L vs. 36.4 ± 7.12 g/L), and fewer blood transfusions in the MAA group (4.0% vs. 18.8%). The incidence of the lateral femoral cutaneous nerve (LFCN) neuropraxia after surgery was 7 (14.6%) in the DAA group and 0 in the MAA group. One fracture was found in each group and managed conservatively.ConclusionMAA and DAA approach yielded excellent and similar early clinical outcomes. However, better patient-reported outcomes could be achieved by MAA THA. The MAA resulted in a safer approach associated with shorter operative times, less blood loss, lower Hb drop, fewer blood transfusions, and LFCN neuropraxia than DAA. A longer follow-up is needed to further examine differences between these procedures.

Excellent and Good Results Treating Stiffness with Early and Late Manipulation after Unrestricted Caliper-Verified Kinematically Aligned TKA.

Manipulation under anesthesia (MUA) for stiffness within 6 to 12 weeks after mechanically aligned total knee arthroplasty (TKA) generally yields better outcome scores than an MUA performed later. However, the timing of MUA after unrestricted, caliper-verified, kinematically aligned (KA) TKA remains uncertain. A retrospective review identified 82 of 3558 (2.3%) KA TKA patients treated with an MUA between 2010 and 2017. Thirty patients treated with an MUA within 3 months of the TKA (i.e., early) and 24 in the late group (i.e., >3 months) returned a questionnaire after a mean of 6 years and 5 years, respectively. Mean outcome scores for the early vs. late group were 78 vs. 62 for the Forgotten Joint Score (FJS) (p = 0.023) and 42 vs. 39 for the Oxford Knee Score (OKS) (p = 0.037). Subjectively, the early vs. late group responses indicated that 83% vs. 67% walked without a limp, 73% vs. 54% had normal extension, and 43% vs. 25% had normal flexion. An MUA within 3 months after unrestricted KA TKA provided excellent FJS and OKS at final follow-up relative to a late MUA. A late MUA performed after 3 months is worth consideration because of the good FJS and OKS scores, albeit with a risk of a persistent limp and limitation in knee extension and flexion.

Perioperative varus alignment does not affect short-term patient-reported outcome measures following mobile-bearing unicompartmental knee arthroplasty

BackgroundAlthough favorable long-term survival of Oxford unicompartmental knee arthroplasty (UKA) has been reported regardless of postoperative varus alignment, the effect of degree of varus alignment on patient-reported outcome measures (PROMs) remains unclear. Furthermore, the Forgotten Joint Score-12 (FJS-12), which has a low ceiling effect, may be useful for such assessment. The objective of this study was to evaluate short-term clinical outcomes after Oxford UKA in knees with a greater degree of preoperative varus alignment focusing on use of the FJS-12.MethodsThis retrospective study involved 66 knees that had undergone primary Oxford UKA. Based on the hip-knee-ankle angle, the knees were divided into two alignment groups: severe varus group (≥ 185° varus alignment) and a mild varus group (< 185° varus alignment). PROMs, including the FJS-12, Knee Injury and Osteoarthritis Outcome Score, and Knee Society Score, were obtained pre- and postoperatively for assessment of clinical outcomes. In addition, the ceiling effect of the FJS-12 was evaluated.ResultsAll PROMs showed significant improvement after surgery. However, there were no statistically significant differences between the severe varus group and the mild varus group. Moreover, no ceiling effect was found for the FJS-12 in this study.ConclusionShort-term results were good for Oxford UKA in knees with a greater degree of varus alignment and were not significantly different from those in knees with mild varus alignment.

Does Retention of the Posterior Cruciate Ligament Lead to a More "Forgotten Joint" Following Total Knee Arthroplasty?

Posterior cruciate ligament (PCL) retention may impact a patient's awareness of their artificial joint following primary total knee arthroplasty (pTKA) due to increased proprioception and more native knee kinematics. Therefore, the purpose of this study was to investigate whether cruciate-retaining (CR) or posterior-stabilized (PS) implants influence the Forgotten Joint Score (FJS-12) following pTKA. We retrospectively reviewed all patients who underwent pTKA with a CR or PS implant at our institute between October 2017 and March 2021. Of the 6,258 patients identified, 5,587 did not have recorded FJS-12 scores at either three months, one year, or two years postoperatively nor a Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR) preoperatively, three months, or one year postoperatively, and these were considered lost to follow up. Thus, a total of 671 cases were identified and subsequently stratified into two cohorts based on whether they received a CR (n=236, 35%) or PS (n=435, 65%) implant. Patients who received PS implants were further divided into constrained (CoN) and non-constrained (NCoN) liner cohorts. Multivariable linear regression analysis was used to compare patient-reported outcome (PRO) scores. There were no significant differences in PRO scores between CR and PS implants at any time point. Patients in the CoN (n=74) cohort had significantly higher FJS-12 scores at one year (CoN: 56.31 + 25.34 vs NCoN: 42.24 + 27.00, p=0.001) and two years (CoN: 58.52 + 33.71 vs NCoN: 46.97 + 27.44, p=0.013) postoperatively compared to patients in the NCoN (n=361) cohort. Although our analysis demonstrated significant differences in FJS-12 scores at one and two years postoperatively depending upon the liner constraint, there were no significant differences in FJS-12 scores between CR and PS implants. Therefore, while retention of the PCL does not impact patient awareness of their artificial joint, the level of liner constraint may influence outcomes if the PCL is sacrificed.

Correlation of patient-reported numbness around surgical scars with patient-reported outcome measures and joint awareness after knee replacement: a cohort study

BackgroundKnee replacement is a very effective and indispensable treatment option for end-stage knee arthritis, and the number of cases has been increasing worldwide. A replaced knee joint without patient joint awareness is thought to be the ultimate goal of artificial knees. Joint awareness reportedly correlates with patient satisfaction. Although numbness around a replaced knee is a minor but common problem, its effect on postoperative outcome is controversial. Joint awareness also is sensitive to subtle abnormalities of the joint, so it must be negatively affected by numbness. Although numbness is minor, it cannot be ignored to further improve knee replacement outcomes. This study investigated the relationship between patient-reported numbness and other patient-reported outcome measures (PROMs), including joint awareness, and kneeling. We developed a numbness score based on a 5-point Likert scale on frequency of numbness, with an intraclass correlation coefficient of 0.76 and higher scores indicating less numbness.MethodsThe numbness score, New Knee Society Score (KSS), Knee Injury and Osteoarthritis Outcome Score (KOOS), Forgotten Joint Score-12 (FJS-12), and other clinical and radiological data from 311 patients (394 primary knee replacements) were analyzed. Kneeling ability was evaluated by using kneeling-specific items in the KSS (KSS-Kneeling).ResultsNo numbness was found in 170 knees (43.1%), and some degree of numbness was found in the remaining 224 knees (56.9%). The numbness score showed weak-to-moderate correlations with KSS-Symptoms (r = 0.44), KSS-Satisfaction (r = 0.41), KSS-Activities (r = 0.29), and all KOOS subscales (r = 0.23–0.44), and FJS-12 (r = 0.42). Multiple regression analyses suggested that midline incision positively affected the numbness score over the anteromedial incision (p = 0.04) and that a better numbness score (p = 0.001), male sex (p < 0.0001), and better postoperative knee flexion angle (0.04) positively affected kneeling.ConclusionsThe numbness score positively correlated with PROMs and positively affected kneeling. Knee replacements performed via an anteromedial incision may be at higher risk for numbness.

Preoperative morbidity and joint awareness while awaiting hip arthroscopy for femoroacetabular impingement

PurposeThe Forgotten Joint Score (FJS-12) is a valid tool in the evaluation of patients undergoing hip arthroscopy, assessing the unique concept of joint awareness in the setting of a patient’s hip pathology. The preoperative burden on patients’ mental wellbeing of impaired joint function or symptoms is well established. The purpose of this study was to determine patients’ awareness of their hip joint whilst awaiting hip arthroscopy for femoroacetabular impingement, to explore any association between joint awareness and mental health status, and to determine whether this relates to time spent waiting for arthroscopy preoperatively.MethodsA prospective database of patients undergoing hip arthroscopy between January 2018 and November 2020 was analysed. All patients with a diagnosis of femoroacetabular impingement (FAI) undergoing arthroscopic treatment were included. Questionnaires included the FJS-12, twelve item international hip outcome tool (iHOT-12), EuroQol 5D-5L (EQ-5D-5L) and the Tegner activity score. Pearson’s correlation coefficient was used to assess relationships between continuous variables.ResultsPreoperative functional outcomes were completed by 81 patients (97.5%) prior to undergoing hip arthroscopy. Median preoperative FJS-12 score was 16.67 (IQR 8.33 – 29.68). Forty-four patients reported any level of anxiety/depression preoperatively (54.3%). Preoperative FJS-12 showed a significant negative correlation with worsening mental health status (r = − 0.359, p < 0.001), and a significant positive correlation with EQ-5D-5L (r = 0.445, p < 0.001). The duration of symptoms or time on the waiting list did not correlate with increased joint awareness or worsened mental health.ConclusionJoint awareness is high when awaiting hip arthroscopy for FAI. Increasing levels of joint awareness correlate with poorer mental health status and poorer quality of life measures, however these parameters do not seem to be associated with increased duration of symptoms prior to surgery or time on the waiting list for surgery.

Normative FJS-12 scores for the knee in an Asian population: a cross-sectional study

BackgroundThe Forgotten Joint Score is a patient-reported outcome measure validated in assessing patients post knee arthroplasty, anterior cruciate ligament (ACL) reconstruction surgery and patellar dislocation. A previous study had established the normative scores of a population in the USA but included knees with pathology. The aim of our study is to obtain normative Forgotten Joint Scores in young Asian adults without any pre-existing knee pathologies to increase the interpretability of the Forgotten Joint Score-12 (FJS-12) score.MethodsWe conducted a cross-sectional study across young healthy Asian adults via electronic platforms. Participants who had sought either Western medical consultation, physiotherapy or traditional medical therapies were excluded. Demographic data, occupation, type of sport played, and FJS-12 scores were collected. Scores were stratified into subgroups and analysed.ResultsThere were 172 participants who met our inclusion criteria for this study. The average age of participants in our study was 28.1 ± 10.5 years (range 14–70 years), with 83 (47.7%) participants falling into the ages 21–25 years. Average body mass index (BMI) was 21.9 ± 3.3 kg/m2 (range 14.7–36.3 kg/m2). The average FJS-12 score was 62.8 ± 25.6. The median FJS-12 was 63.5 with a range of 4.2–100. Nine participants (5.2%) scored the maximum score possible, and 56 (32.6%) participants scored below the midpoint score of 50. The percentiles for each subgroup of participants were tabulated and reported. Notably, males aged 46–70 years old scored the highest average FJS-12 score of 73.4 ± 5.5, and females aged 31–45 years old scored the lowest FJS-12 score of 57.1 ± 25.1. Females scored lower than males, although the difference was not statistically significant (p = 0.157). There were no significant correlations between BMI, age, or type of sport played with FJS-12; however, interestingly, we observed that women reported similar FJS-12 scores across all age groups, while men reported better scores with increasing age.Interestingly,we observed that women reported similar FJS-12 scores across all age groups,while men reported better scores with increasing age. ConclusionHaving normative values provides opportunities for benchmarking and comparing individuals against age- and gender-matched peers in the general population. Knowledge of normative values for FJS-12 scores would aid evaluating and tracking progress in patients recovering from injuries or undergoing post-surgery rehabilitation. This would help clinicians determine if they return to ‘normal’ post intervention.

Translation, cross-cultural adaptation, reliability and construct validity of the Dutch Oxford Knee Score \u2013 Activity and Participation Questionnaire

BackgroundPatients undergoing total knee arthroplasty (TKA) tend to be younger and tend to receive TKA at an earlier stage compared to 20 years ago. The Oxford Knee Score – Activity and Participation (OKS-APQ) questionnaire evaluates higher levels of activity and participation, reflecting activity patterns of younger or more active people. The purpose of this study was to translate the OKS-APQ questionnaire into Dutch, and to evaluate its measurement properties in pre- and postoperative TKA patients.MethodsThe OKS-APQ was translated and adapted according to the forward–backward translation multi step approach and tested for clinimetric quality. Floor and ceiling effects, structural validity, construct validity, internal consistency and test–retest reliability were evaluated using COSMIN quality criteria. The OKS-APQ, the Oxford Knee Score (OKS), the Short Form-36 (SF-36), a Visual Analogue Scale (VAS) for pain and the Forgotten Joint Score (FJS) were assessed in 131 patients (72 preoperative and 59 postoperative TKA patients), and the OKS-APQ was administered twice in 50 patients (12 preoperative and 38 postoperative TKA patients), after an interval of minimal 2 weeks.ResultsFloor effects were observed in preoperative patients. Confirmatory factor analyses (CFA) indicated a good fit of a 1-factor model by the following indices: (Comparative Fit Index (CFI): 0.97, Tucker-Lewis Index (TLI): 0.96 and Standardized Root Mean Square Residual (SRMR): 0.03). Construct validity was supported as > 75% of the hypotheses were confirmed. Internal consistency (Cronbach α’s from 0.81 to 0.95) was good in the pooled and separate pre- and postoperative samples and test–retest reliability (Intraclass Correlation Coefficients (ICCs) from 0.63 – 0.85) were good in postoperative patients and moderate in preoperative patients. The standard Error of Measurements (SEMs) ranged from 8.5 – 12.2 and the Smallest Detectable Changes in individuals (SDCind) ranged from 23.5 – 34.0 (on a scale from 0 to 100).ConclusionsPreliminary findings suggest that the Dutch version of the OKS-APQ is reliable and valid for a Dutch postoperative TKA patient sample. However, in a preoperative TKA sample, the OKS-APQ seems less suitable, because of floor effects and lower test–retest reliability. The Dutch version of the OKS-APQ can be used alongside the OKS to discriminate among levels of activity and participation in postoperative patients.

Reliability and validity of the Hebrew version of the forgotten joint score for assessing the outcomes of total knee arthroplasty

BackgroundThis prospective study aimed to assess the reliability and validity of the Hebrew version of the forgotten joint score-12 in patients undergoing total knee arthroplasty, because it is going to be used in the Hebrew-speaking populations in Israel.MethodsThe English version of forgotten joint score-12 was translated into Hebrew version by using the standard procedures and in collaboration with its authors. The consecutive patients who had undergone total knee arthroplasty in a single hospital were asked to fill out the Hebrew version of forgotten joint score-12, Oxford knee score, Short Form 12, and visual analog scale. A random subgroup of 60 patients were then asked to fill out a second Hebrew version of forgotten joint score-12 at a minimum of 2-week interval. The reliability was assessed in terms of internal consistency, test-retest reliability and split-half reliability. The validity was measured in terms of the outcomes as mentioned above.ResultsA total of 102 patients participated in the study. The Hebrew version of forgotten joint score-12 showed high reliability. The internal consistency was excellent (Cronbachs’ α = 0.943) and test-retest reliability was high (Intraclass correlation = 0.97). The forgotten joint scores were correlated with the Oxford knee score, Short Form 12, and visual analog scale (r = 0.86, r = 0.72, and r=-0.8, respectively), indicating a high validity.ConclusionsThe Hebrew version of forgotten joint score-12 has excellent reliability, excellent test-retest reliability and good validity. It can be safely used for assessing outcomes of TKA.

Patient-reported outcomes after primary rotating hinge total knee arthroplasty: a multi-centre clinical cohort study.

Rotating hinge prostheses for total knee arthroplasty (TKA) are mostly used in revision setting; however, evidence on the use of these constrained devices in primary setting is scarce and inconsistent. Therefore, we aimed to evaluate the functional outcomes after third-generation rotating hinge implants in primary TKA with a minimal follow-up of twoyears in a large dual-centre observational retrospective clinical trial. The hospital databases of two centres were searched for primary rotating hinge arthroplasty from January 2007 to January 2015. A minimum follow-up of at least twoyears was assured. Patients meeting the inclusion criteria were asked to fill out two self-reported functional scores, the Oxford Knee Score (OKS) and Forgotten Joint Score (FJS), to measure the functional status of the knee. In total, 267 primary rotating hinge knee arthroplasties in 242 patients were performed in two centres. The three major indications were axial malalignment (valgus/varus > 15°), 87/267 (33%), persistent ligamentous instability (28%) and neuromuscular disorders (12%). 184 patients with 202 primary rotating hinge knee arthroplasties could be included that provided data of the self-reported outcome measures (OKS and FJS). A mean OKS score of 37.71 (± 9.23) and a mean FJS score of 63.65 (± 31.01) could be obtained. This large clinical study suggests that constrained devices provide the best results when treating bone-on-bone tricompartimental osteoarthritis of the knee with severe axial deviation (valgus/varus > 15°) and/or persistent ligamentous instability.