Aims. To explore key stakeholder views around feasibility and acceptability of trials seeking to prevent post-traumatic osteoarthritis (PTOA) following knee injury, and provide guidance for next steps in PTOA trial design. Methods. Healthcare professionals, clinicians, and/or researchers (HCP/Rs) were surveyed, and the data were presented at a congress workshop. A second and related survey was then developed for people with joint damage caused by knee injury and/or osteoarthritis (PJDs), who were approached by a UK Charity newsletter or Oxford involvement registry. Anonymized data were collected and analyzed in Qualtrics. Results. Survey responses (n = 19 HCP/Rs, 39 PJDs) supported studies testing pharmacological agents preventing PTOA. All HCP/Rs and 30/31 (97%) PJDs supported the development of new treatments that improved or delayed knee symptoms and damage to knee structure. PJDs thought that improving structural knee damage was more important than knee symptoms. Both groups found studies more acceptable as expected future benefit and risk of PTOA increased. All drug delivery routes were acceptable. Workshop participants (around n = 60) reflected survey views. Discussions suggested that stratifying using molecular testing for likely drug response appeared to be more acceptable than using characteristics such as sex, age, and BMI. Conclusion. Our findings supported PTOA drug intervention studies, including situations where there is low risk of disease, no expected benefit of treatment, and frequent treatment administration. PJDs appeared less risk-averse than HCP/Rs. This work reinforces the benefits of consensus and involvement work in the co-creation of PTOA drug trial design. Involvement of key stakeholders, such as PJDs with different risks of OA and regulatory representatives, are critical for trial design success. Cite this article: Bone Joint Res 2024;13(9):513–524

With the rising rates, and associated costs, of total knee arthroplasty (TKA), enhanced clarity regarding patient appropriateness for TKA is warranted. Towards addressing this gap, we elucidated in qualitative research that surgeons and osteoarthritis (OA) patients considered TKA need, readiness/willingness, health status, and expectations of TKA most important in determining patient appropriateness for TKA. The current study evaluated the predictive validity of pre-TKA measures of these appropriateness domains for attainment of a good TKA outcome. This prospective cohort study recruited knee OA patients aged 30+ years referred for TKA at two hip/knee surgery centers in Alberta, Canada. Those receiving primary, unilateral TKA completed questionnaires pre-TKA assessing TKA need (WOMAC-pain, ICOAP-pain, NRS-pain, KOOS-physical function, Perceived Arthritis Coping Efficacy, prior OA treatment), TKA readiness/willingness (Patient Acceptable Symptom State (PASS), willingness to undergo TKA), health status (PHQ-8, BMI, MSK and non-MSK comorbidities), TKA expectations (HSS KR Expectations survey items) and contextual factors (e.g., age, gender, employment status). One-year post-TKA, we assessed for a ‘good outcome’ (yes/no), defined as improved knee symptoms (OARSI-OMERACT responder criteria) AND overall satisfaction with TKA results. Multiple logistic regression, stepwise variable selection, and best possible subsets regression was used to identify the model with the smallest number of independent variables and greatest discriminant validity for our outcome. Receiver Operating Characteristic (ROC) curves were generated to compare the discriminative ability of each appropriateness domain based on the ‘area under the ROC curve’ (AUC). Multivariable robust Poisson regression was used to assess the relationship of the variables to achievement of a good outcome. f 1,275 TKA recipients, 1,053 (82.6%) had complete data for analyses (mean age 66.9 years [SD 8.8]; 58.6% female). Mean WOMAC pain and KOOS-PS scores were 11.5/20 (SD 3.5) and 52.8/100 (SD 17.1), respectively. 78.1% (95% CI 75.4–80.5%) achieved a good outcome. Stepwise variable selection identified optimal discrimination was achieved with 13 variables. The three best 13-variable models included measures of TKA need (WOMAC pain, KOOS-PS), readiness/willingness (PASS, TKA willingness), health status (PHQ-8, troublesome hips, contralateral knee, low back), TKA expectations (the importance of improved psychological well-being, ability to go up stairs, kneel, and participate in recreational activities as TKA outcomes), and patient age. Model discrimination was fair for TKA need (AUC 0.68, 95% CI 0.63-0.72), TKA readiness/willingness (AUC 0.61, 95% CI 0.57-0.65), health status (AUC 0.59, 95% CI 0.54-0.63) and TKA expectations (AUC 0.58, 95% CI 0.54-0.62), but the model with all appropriateness variables had good discrimination (AUC 0.72, 95% CI 0.685-0.76). The likelihood of achieving a good outcome was significantly higher for those with greater knee pain, disability, unacceptable knee symptoms, definite willingness to undergo TKA, less depression who considered improved ability to perform recreational activities or climb stairs ‘very important’ TKA outcomes, and lower in those who considered it important that TKA improve psychological wellbeing or ability to kneel. Beyond surgical need (OA symptoms) and health status, assessment of patients’ readiness and willingness to undergo, and their expectations for, TKA, should be incorporated into assessment of patient appropriateness for surgery

Introduction. Genu valgum is a common presentation in paediatric patients with congenital limb deformities. The aim of this study is to assess the outcome of guided growth surgery in paediatric patients referred via our physiotherapy pathway with isolated genu valgum and associated patellar instability. Materials & Methods. Patients were identified from our prospective patellar instability database. Inclusion criteria was acquired or congenital genu valgum associated with patellar instability in skeletally immature patients. The mechanical lateral-distal femoral angle was assessed on long leg alignment radiographs (mLDFA <85 degrees). Surgical treatment was the placement of a guided growth plate (PediPlate, OrthoPediatrics, USA) on the medial distal femoral physis (hemi-epiphysiodesis). KOOS-child scores were collected pre-operatively and post-operatively (minimum at 6 months). Results. Eleven patients (seven female) with mean age of 12(range 5–15) were identified. Five patients had congenital talipes equinovarus(CTEV), one fibular hemimelia, one di-George syndrome, one septic growth arrest and three had idiopathic genu valgum. Pre- and post-operative KOOS-child scores showed overall improvement: 58(range 36–68) to 88(65–99) and knee symptoms subscores: 64(43–71) to 96(68–100) p<0.01, t-test. Mean follow-up was 10 months (range 3–23). No subsequent dislocations/subluxations occurred during follow-up. Conclusions. Guided growth surgery is an effective way of treating symptomatic patellar instability in skeletally immature patients with genu valgum in the absence of other structural pathology. It was most common in our cohort in patients with unilateral CTEV. We would recommend to screen syndromic and congenital limb deformity patients for patellar instability symptoms in the presence of genu valgum

Aims

The aim of this study was to evaluate the cost-effectiveness of arthroscopic partial meniscectomy versus physical therapy plus optional delayed arthroscopic partial meniscectomy in young patients aged under 45 years with traumatic meniscal tears.

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To assess the incidence of radiological lateral osteoarthritis (OA) at 15 years after medial unicompartmental knee arthroplasty (UKA) and assess the relationship of lateral OA with symptoms and patient characteristics.

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This study investigated the effects of transcatheter arterial embolization (TAE) on pain, function, and quality of life in people with early-stage symptomatic knee osteoarthritis (OA) compared to a sham procedure.

Purpose: The aim of this study was to document donor site problems one year after anterior cruciate ligament (ACL) reconstruction and to compare the differencies between hamstring and patellar tendon autografts. Materilas and Methods: Sixty-four patients undergoing primary arthroscopically ACL reconstruction were randomized to have a central third bone patellar tendon bone (PT) autograft (30 patients) or a doubled semiten-dinosus/doubled gracilis (HS) autograft (34 patients). The postoperative rehabilitation regimen was identical for both groups. All patients were examined one year postoperatively. Objective parameters evaluated included pre and postoperative IKDC and Lysholm score, side-to-side KT-1000 maximum-manual arthrometer differences. The Shelbourne score was used to evaluate anterior knee symptoms. Loss of sensitivity in the anterior knee region postoperatively as well as scar sensitivity were also recorded. Results: Three patients (10%) in the PT group had anterior knee symptoms while only one (3%) in the HS group. The mean Shelbourne score was 98 for the HS group and 93 for the PT group but this was not statistically significant. However, 8 pateints (23%) had disturbed sensitivity in the anterior knee region in the HS group, but none in the PT group and this was statistically significant (p< 0.005). Scar sensitivity was present in 3 patients (10%) in the PT group and in one (3%) in the HS group. No differencies were found postoperatively between the groups regarding IKDC, Lysholm score and side-to-side KT-1000 measurements. Conclusions: Although,notstatisticallysignificantpatients in the PT group had more anterior knee symptoms and scar sensitivity, one year postoperatively. In contrast, harvesting of hamstring tendons produces significantly more sensory nerve complications in the anterior knee region than harvesting the middle third of patellar tendon. Both grafts seem to improve equally patients’ performance

The management of disabling osteoarthritis of the knee following ipsilateral femoral fracture malunion can be difficult. This study presents the results of seven such patients treated by femoral shaft osteotomy in the fracture region and with locked intramedullary nail fixation. Seven patients with malunited femoral shaft fractures presenting with knee symptoms between 1992 and 1999 were treated by femoral shaft osteotomy. The presenting knee symptoms and function were graded from 0–4. All patients underwent open femoral shaft osteotomy at the apex of the deformity and fixation was by locked intramedullary nailing. The patients were followed up until osteotomy union and reviewed clinically and radiologically with particular emphasis on knee symptoms and function. There were six males and one female. The mean age at presentation was 48 years and the mean time from fracture 28 years. (Range 13–37 years). The mean knee alignment angle preoperatively was 5 degrees varus (range 0–12). The mean time to osteotomy union was 28 months. The mean knee alignment angle postoperatively was 2 degrees valgus. (range 5 degrees varus-5 degrees valgus). Five of the seven patients reported excellent pain relief and functional improvement. One patient had serious vascular complication and now has a stiff but pain free knee. One patient who presented with very advanced OA has since undergone an uncomplicated total knee arthroplasty after osteotomy union and nail removal. These patients presenting with severe disability at an age that would be too young for total knee replacement are difficult to manage. Five out seven patients in these series are symptomatically improved to return to their old occupation. The knee replacement has been delayed in these by a mean of five years. Their eventual knee replacement is likely to have been made less difficult as a result of alignment correction

Purpose: The management of disabling knee osteoarthritis of the knee following malunion of an ipsilateral femoral shaft fracture is difficult and controversial. The purpose of this study is to analyse the results of femoral shaft osteotomy at the level of the old fracture in seven such patients. Materials and Methods: Seven patients with old malunited femoral shaft fractures presented with disabling knee osteoarthritis between 1992 and 1999. Knee symptoms and function were graded at presentation. All underwent open femoral shaft osteotomy at the apex of the deformity, with locked intramedullary nail fixation. The patients were followed up regularly until osteotomy union and reviewed clinically and radiologically with particular emphasis on knee symptoms and function. Results: There were six males and one female. The mean age at presentation was 55 years and mean time from the fracture was 28 years (range 13–35 years). The mean preoperative knee alignment angle was 5.60 varus (range O′12′). The mean time to osteotomy union was 28 months. The mean postoperative knee alignment angle was 20 valgus (range 50 valgus -50 varus). All patients reported significant improvement in knee symptoms and function. One osteotomy was followed by a serious vascular complication and the patient now has a stiff but pain free knee. One patient with very advanced osteoarthritis underwent an uncomplicated total knee replacement after osteotomy union and nail removal. Conclusion: These patients presenting with severe disability at an age which is worryingly young for total knee arthroplasty present a difficult management problem. Five out seven patients had excellent symptomatic and functional improvement following the femoral shaft osteotomy. The possible need for knee replacement was delayed by at least 5 years and the eventual arthroplasty is likely to have been made less technically difficult and more functionally satisfactory as a result of the alignment correction

Introduction. The role of the (PCL) in modulating knee kinematics has been well documented. We asked whether function of the (PCL) would be better preserved by incorporating a three-dimensional model for planning and placement. Methods. We evaluated patients (n=59) enrolled into a, prospective, study of conventional instrumentation (25) vs. 3D modeling (34) for (CR) TKA from July 2016 to Feb 2018. Follow-up included clinical exams, PROMs, and serial radiographs up to 24 months after surgery. We measured kinematic patterns radiographically at two years postoperatively. Variables were compared using simple linear regression, one-way ANOVA, and Fisher's exact test. We hypothesized that: 1. well-preserved PCL would demonstrate a more normal kinematic pattern of increasing rollback with increasing knee flexion without paradoxical movement, and 2. this pattern would be associated with improved intra- and post-operative motion and function. Results. The 3D group exhibited a monotonic pattern of increasing rollback in more than twice the proportion of patients as the conventional group (18/34 (53%) vs. 6/25(24%), p=0.034). Two yrs post-operatively, the maximum active flexion was 5 deg greater on average for the 3D group (mean(SD) 111.8(6.6) vs. 106.8 (8.8), p=0.015), and we saw positive linear correlation of femoral rollback with maximum active (r=.39, p=0.002) and passive (r=.45, p<0.001) flexion. Increased rollback was correlated with better Knee Society symptom scores during the early post-operative period (r=.37, p=0.003 and r=.39, p=0.002, respectively). Discussion. This study demonstrates the value of 3D reconstructions to improve kinematics in TKA. In fact, PCL retaining TKA has been consistently linked to paradoxical rollback, predisposing the extensor mechanism to increased stress and reduced femoral clearance, limiting flexion. Paradoxical movement was more prevalent in conventionally instrumented knees. There were notable differences in PROMS even at six weeks post TKR. More normal kinematics were associated with increased motion and improved patient reported outcomes. For any figures or tables, please contact the authors directly

Introduction. Fractures of the distal tibia can be challenging to manage. Numerous surgical techniques have been utilised in managing these however there remains debate as to the optimum method of fixation. This study aims to assess the surgical outcomes and PROMs of patients with distal tibial fractures managed with intramedullary-nails or ring fixation. Methods. This is a retrospective study of patients with closed distal tibial fractures managed between 01/01/2013–31/12/2016. Adult patients admitted with closed fracture of the distal tibia fixed with an intramedullary-nail or circular-frame were included in the study. Primary outcomes were time of union, alignment of tibia post-operatively and the results of two validated PROMs (Kujala knee score and Olerud and Molander Ankle Score). Results. 12 patients had circular-frame and 14 patients underwent intramedullary-nailing. PROMS were completed in 9 (75%) of the frame group and 7 (50%) of the nail group. There was no statistically significant difference in age (p=0.095); no statistically significant difference in time to union (medians = frame 29.7 weeks, IM nail 24 weeks, p=0.212); no statistically significant difference in the coronal angulation difference from neutral (medians = frame 1.9 degrees, IM nail 2.0 degrees, p=0.940). There was statistically significant difference in sagittal angulation difference from neutral (Medians = frame 3 degrees, IM nail 0.6 degrees, p=0.041); the proportion of males in the frames groups was statistically significantly higher (p=0.033). There was no statistically significant difference in outcome of ankle scores (medians = frame 92.5, IM nail 75, p=0.132); there was a statistically significant difference in the knee score favouring the frame group (medians = frame 99, IM nail 74.5, p=0.041). Discussion. Our results show distal tibia fractures can be treated with circular-frames or IM-nails. Patients at high-risk of soft tissue complication or to minimise the risk of knee symptoms should be considered for a circular-frame

We aim to assess the value of patellofemoral Computed Tomography in assessing patients with anterior knee symptoms. Anterior knee symptoms are often due to patellar malalignment. Plain axial radiography or (CT) can be used to investigate these abnormalities. We have evaluated the use of patellofemoral CT scanning in 63 patients and compared the CT findings with the patients’ symptoms. We compared patellar centralisation and patellar tilt angle with the symptom described for each of 126 knees. No difference could be detected in the CT appearances of affected and unaffected knees in those patients with unilateral symptoms (all patients have both knees scanned). A significant association between maltracking and osteoarthiritic changes was demonstrated

Purpose: A three-year evaluation of long-term clinical efficacy of Characterized Chondrocyte Implantation (CCI) compared to microfracture (MF), in the repair of symptomatic cartilage defects of the femoral condyles at 36 months post-surgery. Materials and Methods: In a prospective, randomized, controlled, multicenter trial, CCI was compared to MF in patients aged 18–50 years with a single symptomatic ICRS grade III–IV lesion of the knee. Clinical outcome was measured 36 months after surgery by means of the KOOS, VAS for pain and ARS, with a non-inferiority margin preset at 9 % points for KOOS and VAS. Furthermore, response to treatment and progression of knee symptoms were assessed. Treatment failure was monitored throughout the study. Results: Improvement from baseline was higher in the CCI group (N = 41) compared to the MF group (N = 49) for all clinical outcome parameters. Mean improvement from baseline for Overall KOOS was 22.14 vs. 14.48, respectively, with VAS and ARS scores revealing a similar trend. Responder analysis showed 83% of the patients treated with CCI improving vs. 61% after MF. Additionally, we observed a shift in the proportion of knee symptoms over time (52% vs. 35% of asymptomatic knees at 36 months compared to 2% vs. 8% at baseline in the CCI and MF group respectively). At 36 months, failure rates were low in both groups (n=2 in CCI vs. n=7 in MF). Conclusions: Previous data have described a superior structural repair after CCI compared to MF at 1 year post-surgery. Continued clinical improvement as well as a favorable responder analysis was demonstrated for CCI compared to MF at 36 months

Introduction: The aim of this study was to evaluate the anterior knee symptoms after anterior cruciate ligament reconstruction (ACL) using either pateller tendon (PT) or hamstring tendon (HS) autograft. Materials and Methods: 45 patients undergoing primary ACL reconstruction were randomized to have a PT (23 patients) or a doubled HS (22 patients). Patients were reviewed after 3, 6, and 9 months. Patients were examined for knee pain and sensory changes in the anterior aspect of the knee, the ability for kneeling and sensitivity of the surgical incision. Results: At the last follow-up in the PT group 4 patients (17%) had anterior knee pain, knee-walking test was impossible for 4 patients (17%), 3 patients (13%) reported to have surgical incision sensitivity and 4 patients (17%) had numbness in the skin area supplied by the infrapatellar branch of the saphenous nerve. In the HS group, 2 patients (9%) had anterior knee pain, knee-walking test was impossible for 2 patients (9%), 2 patients (9%) reported to have surgical incision sensitivity and 10 patients (45%) had numbness in the skin area supplied by the infrapatellar branch of the saphe-nous nerve. There was a statistical significant difference (p< 0.05) regarding the sensory changes in the anterior aspect of the knee. Conclusions: Harvesting of the PT or HS autograft for ACL reconstruction is associated with a low rate of anterior knee symptoms. Sensory changes following HS harvesting is significantly higher. However, this does not appear to be of great clinical importance without limitation of activities

Introduction. Overwhelming evidence has established obesity as a risk factor for osteoarthritis (OA) of the knee. Randomized clinical trials such as the Look AHEAD study have shown long term successful intentional weight loss with an intensive lifestyle intervention (ILI) in overweight and obese type 2 diabetics. Weight loss can also decrease knee pain in persons who have OA, but it is unknown if intentional weight loss can reduce the risk of TKR. To answer this question, data from the Look AHEAD study were examined to determine if intentional weight loss could reduce the risk of TKR. Methods. Look AHEAD is a multicenter, randomized trial which began in August 2001 and follow-up continued for a median of 11.3 years at 16 academic centers. 5145 persons aged 45–76 with diabetes were randomized to either an ILI with reduced calorie consumption and increased physical activity designed or to diabetes support and education intervention (DSE). TKR events were ascertained every 6 months. Retrospective data of reported knee pain was assessed using the WOMAC knee pain questionnaire. Participants with partial TKR or revisions were excluded. Cox proportional hazard models were used to relate baseline BMI category (obese, Class I, Class II, or Class III obesity), baseline knee pain, and treatment group with TKR. Weight change category (lost<=5%, stable, gained>=2%) from baseline to year 1 follow-up by treatment assignment was also examined as a predictor of TKR after excluding TKR occurring prior to year 1. Results. Out of the randomized participants, 2171 reported knee pain (43%) at the baseline visit (p=0.81). WOMAC knee pain score did not differ by random assignment (ILI:3.6±2.9, DSE:3.9±3.0, p=0.08). During follow up there were 631 TKRs reported by participants. TKR was more common in heavier (p<0.001), and older (p<0.001) participants and did not differ by randomization. Heterogeneity of treatment effect was observed with baseline knee pain (interaction p = 0.02), therefore analyses were stratified by presence or absence of knee pain at baseline. In persons without knee pain at baseline, there was a 29% reduced rate of TKR in the ILI group compared to the DSE group (HR[95%CI] 0.71[0.52,0.96]; Figure 1A). Whereas in persons with knee pain at baseline, there was a trend for the ILI to have an increased rate of TKR compared to DSE (1.11[0.92, 1.33]; Figure 1B). In both sets of analyses, obese participants had significantly higher hazard of TKR than overweight participants (No pain: Class I 1.78[1.04,3.05], Class II 2.27 [1.31,3.94], Class III 2.94[1.67,5.18]; With pain: Class I 1.70[1.12,2.59], Class II 2.42 [1.60,3.65], Class III 2.80[1.85,4.23]). When TKR incidence was examined by weight change at year 1 there was no difference in weight change category between randomization groups in persons with knee pain (interaction p=0.20) or without baseline knee pain (interaction p=0.87) (Figure 1C and D) or for the overall effect of year 1 weight loss category in either stratum (with knee pain p=0.26, without knee pain p=0.48). However, in persons without knee pain at baseline, ILI had a marginal reduction in hazard of TKR compared to DSE (0.71[0.49, 1.05]) but not in the group with baseline knee pain. Conclusions. In persons with no knee pain at baseline and who were overweight or had Class I or II obesity, ILI seemed to reduce the risk of TKR compared to DSE. In contrast, persons with knee pain who gained weight at 1 year and were randomized to ILI had the highest risk of TKR. This suggests that weight loss to prevent TKR may be more effective prior to the development of significant knee pain. After the onset of knee pain however, low impact or non-weight bearing activity should be considered to avoid worsening knee symptoms. For any figures or tables, please contact authors directly

Introduction and aim: Several authors have suggested that hyaline repair tissue following autologous – chondrocyte implantation (ACI) gives better clinical results than either mixed hyaline and fibrocartilage or fibrocartilage alone. This data is based on the use of periosteum as a covering membrane in these previous studies. We have for some years been using a porcine collagen type 1/III membrane (ACI-C) instead of periosteum and have now the opportunity to analyze the clinical results when compared with the histology of the repaired defect. We have also analysed the influence on the result of age and sex of the patient, the etiology of the lesion, the duration of the knee symptoms, number of previous knee procedures, the site and size of defect and the preoperative functional scores. Method: Until 2004, 234 patients underwent autologous chondrocyte implantation at our centre. The patients were assessed clinically by their modified Cincinnati scores prospectively from 1 to 4 years from surgery. Also at arthroscopy (1 to 3 years following ACI-C) they underwent biopsy of the implant where possible and the neo-cartilage was graded as hyaline (H), mixed fibrohyaline (F.H), fibrocartilagenous (F.C) and fibrous (F). Results: The clinical results showed that older patients had poorer results (p< 0.001) and a high preoperative modified Cincinnati score predicted a good result (p< 0.001). Concerning the cause of the defect, the percentage of patients with excellent and good results were significantly low among those with previously failed ACIs and mosaicplaties (12.5%) compared with those following trauma, osteochondritis dessicans and chondromalacia patellae (67% to 77%). At 4 year follow-up, 75% of patients with hyaline neo-cartilage had excellent and good modified Cincinnati scores whereas those with mixed fibro-hyaline and fibro-cartilage had fewer excellent and good results (44.4% and 54.5% respectively). The other parameters such as gender, the site of defect, duration of knee symptoms and the number of previous procedures and the size of the defect did not significantly influence the outcome. In conclusion, patients most likely to benefit from autologous chondrocyte implantation using a collagen membrane (ACI – C) are younger patients with higher preoperative functional scores and those who develop hyaline neo-cartilage

The aim of this study was to determine if patient reported outcome scores for arthroscopic meniscectomy are adversely affected by the degree of knee osteoarthritis or patient body mass index (BMI). All patients who underwent arthroscopic meniscectomy within the NHS in Scotland between 6th February and 29th April 2012 were audited as part of the Scottish Government Musculoskeletal Knee Arthroscopy Audit and were eligible for inclusion within this study. A total of 270 patients returned both their pre-operative and post-operative EuroQol 5Q5D5L descriptive questionnaire and Knee injury and Osteoarthritis Outcomes Scores. Patients were stratified according to BMI, degree of osteoarthritis, history of injury, and duration of knee symptoms. Pre-operative to post-operative EuroQol index scores [0.642±0.253 to 0.735±0.277, median±SD] and Knee injury and Osteoarthrtis Outcome Scores [44.63±18.78 to 62.28±24.94, median±SD] improved across all patients (p<0.0001). This was irrespective of degree of BMI, history of injury, or duration of symptoms. There was no such improvement in patients with moderate to severe osteoarthritis. Those patients with a BMI >35 kg/m2 had lower post-operative scores than the pre-operative scores of those of BMI <30 kg/m2. Arthroscopic meniscectomy is beneficial regardless of patient BMI, duration of symptoms, history of injury, or in the presence of mild arthritis

Limb alignment in total knee arthroplasty (TKA) influences periarticular soft-tissue tension, biomechanics through knee flexion, and implant survival. Despite this, there is no uniform consensus on the optimal alignment technique for TKA. Neutral mechanical alignment facilitates knee flexion and symmetrical component wear but forces the limb into an unnatural position that alters native knee kinematics through the arc of knee flexion. Kinematic alignment aims to restore native limb alignment, but the safe ranges with this technique remain uncertain and the effects of this alignment technique on component survivorship remain unknown. Anatomical alignment aims to restore predisease limb alignment and knee geometry, but existing studies using this technique are based on cadaveric specimens or clinical trials with limited follow-up times. Functional alignment aims to restore the native plane and obliquity of the joint by manipulating implant positioning while limiting soft tissue releases, but the results of high-quality studies with long-term outcomes are still awaited. The drawbacks of existing studies on alignment include the use of surgical techniques with limited accuracy and reproducibility of achieving the planned alignment, poor correlation of intraoperative data to long-term functional outcomes and implant survivorship, and a paucity of studies on the safe ranges of limb alignment. Further studies on alignment in TKA should use surgical adjuncts (e.g. robotic technology) to help execute the planned alignment with improved accuracy, include intraoperative assessments of knee biomechanics and periarticular soft-tissue tension, and correlate alignment to long-term functional outcomes and survivorship.

Introduction. Total knee arthroplasty (TKA) is a well-established procedure associated with excellent clinical results. We have previously reported that intraoperative knee kinematics correlate with the clinical outcome in mobile bearing TKA. In addition, the intraoperative knee kinematics pattern does not correlate with the degree of preoperative knee deformity in mobile bearing TKA. However, the relationship among preoperative knee deformity, intraoperative kinematics and clinical outcome in fixed bearing TKA has been unknown. The purpose of this study is to compare the relationship among preoperative knee deformity, knee kinematics after fixed bearing TKA and the clinical outcome including the subjective outcomes evaluated by the new knee society score (KSS). Materials and Methods. A cross-sectional survey of thirty-five consecutive medial osteoarthritis patients who had a primary TKA using a CT-based navigation system was conducted. All knees had a Kellgren-Lawrence grade of 4 in the medial compartment and underwent a primary posterior stabilized TKA (Genesis II, Smith&Nephew) between May 2010 and October 2012. In all cases, a computed tomography-guided navigation system (Brain LAB, Heimstetten, Germany) was used. All surgery was performed by the subvastus approach and modified gap technique. Intraoperative knee kinematics was measured using the navigation system after implantation and closure of the retinaculum and soft tissue except for the skin. Subjects were divided into two groups based on intraoperative kinematic patterns: a medial pivot group (M group, n=19)(Figure 1) and a non-medial pivot group (N group, n=16)(Figure 2). Subjective outcomes with the new KSS and clinical outcomes were evaluated. Statistical analysis to compare the two groups was made using unpaired a Student t test. Result. Regarding the postoperative clinical result (knee flexion angle, knee extension angle, mechanical FTA,% mechanical axis), there were no significant differences between the two groups. Although there were also no significant differences in KSS evaluation between the two groups, there was a tendency for M group to be superior to N group in current knee symptom (M group: 17.3±5.6, N group: 12.9±8.2, p = 0.07) and functional activities (M group: 55.1±21.5, N group: 42.7±22.6, p = 0.10). Regarding preoperative examination, varus knee deformity (mechanical FTA and% mechanical axis) in N group was significantly more severe than that of M group (p=0.04, p=0.04, respectively). Discussion. Over half of patients (54%) could achieve medial pivot kinematics in fixed bearing TKA with the possibility to improve a subjective clinical result. Although we previously could not detect any relationship between preoperative varus knee deformity and intraoperative kinematics in mobile bearing TKA, the preoperative varus knee deformity in the non-medial pivot group was significantly severer than that of the medial pivot group in fixed type TKA. Our results indicate that if a TKA is done to a severe varus knee deformity the postoperative knee kinematics tend to result in a non-medial pivot pattern. In conclusion, because it tends to result in a non-medial pivot pattern, extra care needs to be taken to avoid postoperative abnormal knee kinematics in the performance of a fixed type TKA to a severe varus knee deformity

Recently in the literature the indications of unicompartmental knee arthroplasty have been extended by the inclusion of patients with arthritis which is predominantly but not exclusively effecting the medial compartment. The aim of this study is to evaluate the outcome of MAKO unicondylar replacement in the treatment of knee osteoarthritis after the initial surgical insult is worn off to evaluate the impact of residual patellofemoral and lateral osteoarthritis on the outcome of medial unicompartmental knee replacement. 135 patients who underwent uncomplicated 144 MAKO medial unicondylar replacements for knee arthritis were identified and studied. Original radiographs were used to classify severity of patellofemoral and lateral compartmental osteoarthritis in these patients. Severity of patellofemoral and lateral compartmental osteoarthritis was analyzed against Oxford and Knee Society (AKSS) scores and amount of ipsilateral residual knee symptoms at 6 months post-operative period. Pre-operative Oxford and Knee Society scores, and other comorbidities and long term disability were studied as confounding variables. We found significant improvement in symptoms and scores in spite of other compartment disease. Poorer outcome was seen in association with comorbidities and long term disability but not when radiographic signs of arthritis in the other compartments were present. Six patients required revision of which three had (lateral facet) patellofemoral disease in the original x-rays. In conclusion there is no direct relationship between postoperative symptoms and poor outcome and radiographic disease in the other compartments. However when symptoms are severe enough to necessitate revision this is due to patellofemoral and not lateral compartment disease