High Expectations Among Patients Who Have Undergone TKA Do Not Correlate With Satisfaction.

BACKGROUND: One of five patients is dissatisfied with the outcome of TKA. With the increasing number of TKAs, this affects many patients. It has been suggested that high expectations may influence satisfaction, but the relationship between preoperative patient expectations and postoperative patient satisfaction remains poorly understood. QUESTIONS/PURPOSES: (1) Are preoperative patient expectations correlated with postoperative satisfaction? (2) Are expectations correlated with patient characteristics or patient-reported outcome measures (PROMs)? (3) Is satisfaction correlated with patient characteristics or PROMs? (4) Do patients report specific items as more relevant to their expectations? METHODS: This was a single-center, observational, retrospective, comparative study involving patients who underwent TKA. Between December 2020 and June 2022, three senior surgeons performed 306 TKAs. Of these, 76% (234) had the preoperative PROMs required for this study, and of these, 82% (193) had completed PROMs at the 12-month follow-up interval and were analyzed. Of the 193 included patients, 53% (102) were women; the mean age was 68 ± 9 years. Data were collected at baseline, 4 months, and 12 months. Twelve months of follow-up has been shown to be adequate in studies with PROMs. Patient expectations were measured using the validated Hospital for Special Surgery Knee Replacement Expectation Survey on a scale from 0 to 100, with higher scores indicating higher expectations. We also assessed patient satisfaction, the Knee injury and Osteoarthritis Outcome Score, Forgotten Joint Score, High-Activity Arthroplasty Score, EQ-5D-3L, and the objective Knee Society Score. Bivariate linear correlations were analyzed using the Pearson or Spearman test. RESULTS: Preoperative patient expectations did not correlate with postoperative satisfaction. The mean Hospital for Special Surgery Knee Replacement Expectation Survey score was 82 ±16 points and did not correlate with satisfaction at either 4 months (r = -0.061; p = 0.42) or 12 months (r = -0.126; p = 0.11). Expectations did not correlate with patient characteristics or any of the preoperative or postoperative PROMs or the Knee Society Score. Patient satisfaction was 88% (158 of 179) at 4 months and 83% (160 of 193) at 12 months and did not correlate with patient characteristics or any of the preoperative PROMs or Knee Society Score. Patient satisfaction was medium to strongly correlated with postoperative PROMs and Knee Society Score. The Hospital for Special Surgery Knee Replacement Expectation Survey items with the most frequent expected improvement were "ability to walk" (99% [192 of 193]), "go downstairs" (99% [191 of 192]), and "go upstairs" (99% [192 of 193]). CONCLUSION: Preoperative expectations were not correlated with postoperative satisfaction or PROMs. Surgeons should be aware that patients have high expectations. However, these expectations appear to be less relevant in determining postoperative satisfaction. LEVEL OF EVIDENCE: Level III, therapeutic study.

Comparison of Responsiveness of Patient-Reported Outcome Measures After Total Knee Arthroplasty.

BACKGROUND: The aim of this study was to evaluate the responsiveness of different patient-reported outcome measures in patients with primary total knee arthroplasty (TKA). METHODS: In this prospective observational study, we assessed patients with TKA before the surgery, after 4 months, after 1 year, and after 2 years. Measures were the objective Knee Society Score (KSS) and the following patient-reported outcome measures: Knee injury and Osteoarthritis Outcome Score (KOOS), KOOS-12, Forgotten Joint Score (FJS-12), High-Activity Arthroplasty Score, and EQ-5D-3L. Responsiveness was determined by effect size (ES), standardized response mean (SRM), area under the receiver operating characteristics curve, floor and ceiling effects, and hypothesis testing. RESULTS: We analyzed data from 309 TKAs (272 patients, 56% female). The ES and SRM for the change in KSS, KOOS, KOOS-12, FJS-12, and EQ-5D-3L from baseline to each follow-up were large (>0.8). The largest responsiveness from baseline to follow-up was found for the KSS, KOOS/KOOS-12 quality of life, KOOS-12 summary, KOOS-12 pain, and FJS-12 (2.0 > ES <3.9, 1.4 > SRM <2.4). The area under the curve from baseline to each follow-up was ≥0.7 for KOOS, KOOS-12, and FJS-12 (range 0.71 to 0.95) and <0.7 for KSS and EQ-5D-3L (range 0.65 to 0.74). We found floor or ceiling effects in the KOOS, KOOS-12, and EQ-5D-3L, but not in the KSS, FJS-12, and High-Activity Arthroplasty Score. CONCLUSIONS: Our study demonstrated that responsiveness differed between the various measures. The KOOS-12 and FJS-12 showed the greatest internal and external responsiveness, although ceiling effects occurred in the KOOS-12.

Satisfaction after total knee arthroplasty: a prospective matched-pair analysis of patients with customised individually made and off-the-shelf implants.

PURPOSE: Customised individually made (CIM) total knee arthroplasty (TKA) was introduced to potentially improve patient satisfaction and other patient-reported outcome measures (PROMs). The purpose of this study was to compare PROMs, especially patient satisfaction, of patients with CIM and OTS TKA in a matched-pair analysis with a 2-year follow-up. METHODS: This is a prospective cohort study with a propensity score matching of 85 CIM and 85 off-the-shelf (OTS) TKA. Follow-up was at 4 months, 1 year and 2 years. The primary outcome was patient satisfaction. Secondary outcomes were as follows: overall improvement, willingness to undergo the surgery again, Knee injury and Osteoarthritis Outcome Score (KOOS), Forgotten Joint Score (FJS-12), High-Activity Arthroplasty Score (HAAS), EQ-5D-3L, EQ-VAS, Knee Society Score (KSS) and surgeon satisfaction. RESULTS: Patient satisfaction ranged from 86 to 90% and did not differ between CIM and OTS TKA. The EQ-VAS after 4 months and the HAAS after 1 year and 2 years were higher for CIM TKA. KOOS, FJS-12 and EQ-5D-3L were not different at follow-up. The changes in KOOS symptoms, pain and daily living were higher for OTS TKA. The KSS was higher for patients with CIM TKA. Surgeon satisfaction was high throughout both groups. Patients who were satisfied after 2 years did not differ preoperatively from those who were not satisfied. Postoperatively, all PROMs were better for satisfied patients. Patient satisfaction was not correlated with patient characteristics, implant or preoperative PROMs, and medium to strongly correlated with postoperative PROMs. CONCLUSION: Patient satisfaction was high with no differences between patients with CIM and OTS TKA. Both implant systems improved function, pain and health-related quality of life. Patients with CIM TKA showed superior results in demanding activities as measured by the HAAS. LEVEL OF EVIDENCE: II, prospective cohort study.

The impact of different alignment strategies on bone cuts in total knee arthroplasty for varus knee phenotypes.

PURPOSE: The purpose of this study was to visualise the influence of alignment strategy on bone resection in varus knee phenotypes. The hypothesis was that different amounts of bone resection would be required depending on the alignment strategy chosen. Through visualisation of the corresponding bone sections, it was hypothesised, it would be possible to assess which of the different alignment strategies would require the least amount of change to the soft tissues for the chosen phenotype, whilst still ensuring acceptable alignment of the components, and thus could be considered the most ideal alignment strategy. METHODS: Simulations of the different alignment strategies (mechanical, anatomical, constrained kinematic and unconstrained kinematic) in relation to their bone resections were performed on five common exemplary varus knee phenotypes. VARHKA174° VARFMA87° VARTMA84°, VARHKA174° VARFMA90° NEUTMA87°, VARHKA174° NEUFMA93° VARTMA84°, VARHKA177° NEUFMA93° NEUTMA87° and VARHKA177° VALFMA96° VARTMA81°. The phenotype system used categorises knees based on overall limb alignment (i.e. hip knee angle) but also takes into account joint line obliquity (i.e. TKA and FMA) and has been applied in the global orthopaedic community since its introduction in 2019. The simulations are based on long-leg radiographs under load. It is assumed that a change of 1° in the alignment of the joint line corresponds to a displacement of the distal condyle by 1 mm. RESULTS: In the most common phenotype VARHKA174° NEUFMA93° VARTMA84°, a mechanical alignment would result in an asymmetric elevation of the tibial medial joint line by 6 mm and a lateral distalisation of the femoral condyle by 3 mm, an anatomical alignment only by 0 and 3 mm, a restricted by 3 and 3 mm, respectively, whilst a kinematic alignment would result in no change in joint line obliquity. In the similarly common phenotype 2 VARHKA174° VARFMA90° NEUTMA87° with the same HKA, the changes are considerably less with only 3 mm asymmetric height change on one joint side, respectively, and no change in restricted or kinematic alignment. CONCLUSION: This study shows that significantly different amounts of bone resection are required depending on the varus phenotype and the alignment strategy chosen. Based on the simulations performed, it can, therefore, be assumed that an individual decision for the respective phenotype is more important than the dogmatically correct alignment strategy. By including such simulations, the modern orthopaedic surgeon can now avoid biomechanically inferior alignments and still obtain the most natural possible knee alignment for the patient.

The impact of different alignment strategies on bone cuts for neutral knee phenotypes in total knee arthroplasty.

PURPOSE: The purpose of this study was to simulate and visualise the influence of the alignment strategy on bone resection in neutral knee phenotypes. It was hypothesised that different amounts of bone resection would be required depending on the alignment strategy chosen. The hypothesis was that by visualising the corresponding bone cuts, it would be possible to assess which of the different alignment strategies required the least change to the soft tissues for the chosen phenotype but still ensured acceptable component alignment and could, therefore, be considered the most ideal alignment strategy. METHODS: Simulations of the different alignment strategies (mechanical, anatomical, restricted kinematic and unrestricted kinematic) regarding their bone resections were performed on four common exemplary neutral knee phenotypes. NEUHKA0° VARFMA 90° VALTMA90°, NEUHKA0° NEUFMA 93° NEUTMA87°, NEUHKA0° VALFMA 96° NEUTMA87° and NEUHKA0° VALFMA 99° VARTMA84°. The phenotype system used categorises knees based on overall limb alignment (i.e. hip knee angle) but also considers joint line obliquity (i.e. TKA and FMA) and has been used globally since its introduction in 2019. These simulations are based on long leg weightbearing radiographs. It is assumed that a change of 1° in the alignment of the joint line corresponds to correspond to 1 mm of distal condyle offset. RESULTS: In the most common neutral phenotype NEUHKA0° NEUFMA 93° NEUTMA87°, with a prevalence of 30%, bone cuts remain below 4 mm regardless of alignment strategy. The greatest changes in the obliquity of the joint line can be expected for the mechanical alignment of the phenotype NEUHKA0° VALFMA 99° VARTMA84° where the medial tibia is raised by 6 mm and the lateral femur is shifted distally by 9 mm. In contrast, the NEUHKA0° VARFMA 90° VALTMA90° phenotype requires no change in joint line obliquity if the mechanical alignment strategy is used. CONCLUSION: Illustrations of alignment strategies help the treating surgeon to estimate the postoperative joint line obliquity. When considering the alignment strategy, it seems reasonable to prefer a strategy where the joint line obliquity is changed as little as possible. Although for the most common neutral knee phenotype the choice of alignment strategy seems to be of negligible importance, in general, even for neutral phenotypes, large differences in bone cuts can be observed depending on the choice of alignment strategy.

No difference in patient-reported satisfaction after 12 months between customised individually made and off-the-shelf total knee arthroplasty.

PURPOSE: A subset of patients is usually not satisfied after a total knee arthroplasty (TKA). Customised individually made (CIM) TKA are deemed to overcome drawbacks of classical off-the-shelf (OTS) TKA, but evidence is still sparse. The aim of this study was to compare satisfaction of patients with CIM and OTS TKA. METHODS: This prospective cohort study compared clinical and patient-reported outcome measures (PROM) between patients with CIM and OTS TKA. The primary outcome was patient satisfaction after 12 months. Secondary outcomes were the Knee Society Score (KSS), the Knee injury and Osteoarthritis Outcome Score (KOOS), the Forgotten Joint Score (FJS-12) and the EQ-5D-3L after 4 and 12 months. RESULTS: Data were analysed from 74 CIM TKA and 169 OTS TKA between January 2017 and September 2020. Patients with CIM TKA were slightly younger, more often male, had a lower body mass index, a lower KSS and partially higher preoperative PROMs. Patient satisfaction after 12 months was high and comparable (CIM 87%, OTS 89%). All PROMs improved for both groups (p < 0.001) and did not differ after 12 months (p > 0.063). The majority of patients improved above the minimal important difference (range 65 to 89%) and reported a clear overall improvement (CIM 86%, OTS 87%). The postoperative KSS, notably regarding knee stability, was higher for CIM TKA (p < 0.001). CONCLUSION: No difference was found in patient satisfaction between CIM and OTS TKA after 12 months. In both groups, patient satisfaction was high and PROMs improved considerably. LEVEL OF EVIDENCE: II, prospective cohort study.

Relevant changes of leg alignment after customised individually made bicompartmental knee arthroplasty due to overstuffing.

PURPOSE: The purpose of this study is to analyse the change in knee alignment after customised individually made (CIM) bicompartmental knee arthroplasty (BKA) and the subsequent consequences for patellar tracking. METHODS: Medical records of 23 patients who received 26 CIM BKA (ConforMIS iDuo G2) at our clinic between November 2015 and July 2018 were reviewed. The objective part of the Knee Society Score (KSS), the hip-knee-ankle angle (HKA), the tibial mechanical angle (TMA) and femoral mechanical angle (FMA) were recorded preoperative and four months postoperative. Leg alignment was classified as neutral (HKA = 180° ± 3°), varus (HKA < 177°) or valgus (HKA > 183°). Furthermore, patellar tracking was determined on skyline view radiographs and adverse events were recorded. Implant survival rate was determined with the Kaplan-Meier method. Patient-reported outcome measures (PROMs) were pain, satisfaction, overall improvement and if the patient would undergo the surgery again. RESULTS: The mean KSS improved from 61 points preoperative [standard deviation (SD) 14] to 90 points postoperative (SD 7, p < 0.001). The mean change for HKA was 6.3° (SD 3.5), for TMA 1.5° (SD 1.2) and for FMA 3.8° (SD 2.3). Postoperative leg alignment was neutral in 13 CIM BKA (50%), varus in two (8%) and valgus in 11 (42%) and patella tracking was central in 19 CIM BKA (73%) and lateral in seven (27%), respectively. Adverse events occurred in five CIM BKA: three patients required a patella resurfacing and one patient with bilateral CIM BKA needed a revision to a total knee arthroplasty. Implant survival rate was 92.3% at a follow-up of 3.2 years (SD 0.8). PROMs for CIM BKA without revision surgery were available at a mean follow-up of 3.2 years (SD 0.8). Mean pain with level walking decreased to 0.8 points (SD 1.4, p < 0.001) and mean pain with stairs or inclines to 1.6 points (SD 1.3, p < 0.001). Patient satisfaction was very satisfied or satisfied (78%), neutral (17%) or unsatisfied (4%). Overall improvement was much better or considerably better for 91% of all patients; 87% would undergo the surgery again. CONCLUSION: A relevant change of the leg axis away from the treated femorotibial compartment due to overstuffing was observed. Although, neutral leg alignment was not restored in every case, clinical and patient-reported outcomes improved significantly. Further studies with long-term clinical and patient-reported outcomes are required to evaluate whether patients with bicompartmental knee osteoarthritis benefit from CIM BKA. LEVEL OF EVIDENCE: IV, case series.

The German version of the High-Activity Arthroplasty Score is valid and reliable for patients after total knee arthroplasty.

PURPOSE: The indications for a total knee arthroplasty (TKA) broadened to younger and more active patients. The High-Activity Arthroplasty Score (HAAS) is a self-administered instrument focussing on the wider range of functional abilities of more active patients. The HAAS was developed in English and is not available in German yet. This study aims to translate, cross-cultural adapt and assess the psychometric properties of the German HAAS in patients 12 months after primary TKA. METHODS: After forward and backward translation, we examined the final version regarding its psychometric properties in patients 12 months after primary TKA. The HAAS was sent out to 70 patients together with routine questionnaires comprising the Knee injury and Osteoarthritis Outcome Score (KOOS), the Forgotten Joint Score (FJS-12), the EuroQol (EQ-5D-3L) and 2 numerical pain rating scales. Acceptability, reliability, responsiveness, content and construct validity as well as floor and ceiling effects were evaluated. RESULTS: Fifty-two patients were recruited. The HAAS was well accepted with a mean time to completion of 2.4 min. Cronbach's alpha for internal consistency was 0.749, test-retest reliability was excellent with an Intraclass Correlation Coefficient (ICC) of 0.961. The smallest detectable change was 1.5. Good content validity was confirmed. A strong correlation was found between the HAAS and KOOS sport (r = 0.661) and a medium correlation for all other KOOS subscales (r = 0.324 to 0.453), the FJS-12 (r = 0.425), the EQ-5D-3L (r = 0.427) and pain (r = - 0.439 to - 0.308). The HAAS showed no floor and ceiling effects. CONCLUSIONS: The German version of the HAAS provides good validity and reliability. It can be easily self-administered and is recommended to capture high-intensity activities in patients after TKA. LEVEL OF EVIDENCE: Diagnostic study, Level I.

Customised, individually made total knee arthroplasty shows promising 1-year clinical and patient reported outcomes.

INTRODUCTION: Customised individually made (CIM) implants for total knee arthroplasty (TKA) were introduced about 10 years ago. These implants aim to reduce the risk of prosthesis-related issues resulting from anthropometric differences between different knees. The purpose of this study was to analyse the short-term clinical outcome and patient reported outcome measures (PROMs) of a specific CIM implant, the ORIGIN® knee replacement system (Symbios, Yverdon-les-Bains, Switzerland), which was introduced in 2018. MATERIALS AND METHODS: This is a prospective cohort study of patients undergoing primary posterior-stabilised (PS) CIM TKA using the specific ORIGIN® knee replacement system, (Symbios, Yverdon-les-Bains, Switzerland). TKAs were performed from February 2019 to October 2020. Data was collected preoperatively and postoperatively at 4 and 12 months. Outcome measures included the objective part of the Knee Society Score (KSS) with the range of motion (ROM) and the following PROMs: the Knee injury and Osteoarthritis Outcome Score (KOOS), the Forgotten Joint Score (FJS-12), the EuroQol, five dimensions, three levels (EQ-5D-3L) with the EuroQol visual analogue scale (EQ-VAS) and patient satisfaction. Differences in pre- to preoperative data were assessed with paired sample t tests. A p value < 0.05 was considered significant. RESULTS: Twenty-five CIM TKA (20 patients, 8 female) were included. The mean age at surgery was 66 years (SD, 6.9). At 4 and 12 months, significant improvements in the KSS (p < 0.001), the ROM (p < 0.001), all KOOS subscales (p < 0.001), the FJS (p < 0.001) and the EQ-5D-3L (p < 0.026) were found. Satisfaction rate was 91% and 88% at 4 and 12 months, respectively. Intraoperative complications did not occur and no revision surgeries were undertaken. CONCLUSIONS: The present study demonstrated significant improvements in the KSS and specific PROMs 1 year after CIM TKA. This study suggests that CIM TKA is a safe and suitable option, which can yield good clinical outcome and PROMs at least during short-term follow-up.

ACL Study Group survey reveals the evolution of anterior cruciate ligament reconstruction graft choice over the past three decades.

PURPOSE: Anterior cruciate ligament reconstruction (ACLR) aims to restore knee function and stability, allowing patients to return to the activities they enjoy and minimize further injury to the meniscus and cartilage and their ultimate progression to osteoarthritis. This study aims to present the evolution of graft choice over the last three decades according to members of the ACL Study Group (SG). METHODS: Prior to the January 2020 ACL SG biannual meeting, a survey was administered consisting of 87 questions and 16 categories, including ACLR graft choice. A similar questionnaire has been administered prior to each meeting and survey results from the past 14 meetings (1992 through 2020, excluding 1994) are included in this work. Survey responses are reported as frequencies in percentages to quantify changes in practice over the surgery period. RESULTS: In 1992, the most frequent graft choice for primary ACLR was bone-patellar tendon-bone (BTB) autograft, at nearly 90%. Hamstring tendon (HT) autografts have increased in popularity, currently over 50%, followed by just under 40% BTB autograft. Recently, quadriceps tendon (QT) autograft has increased in popularity since 2014. CONCLUSION: Autograft (HT, BTB, QT) is an overwhelming favorite for primary ACLR over allograft. The preference for HT autograft increased over the study period relative to BTB autograft, with QT autograft gaining in popularity in recent years. Graft selection should be individualized for each patient and understanding the global trends in graft choice can help orthopaedic surgeons discuss graft options with their patients and determine the appropriate graft for each case. LEVEL OF EVIDENCE: Level V, Expert Opinion.

Comparison of Human Articular Cartilage Tissue and Chondrocytes Isolated from Peripheral versus Central Regions of Traumatic Lesions.

OBJECTIVE: Cellular and molecular events occurring in cartilage regions close to injury are poorly investigated, but can possibly compromise the outcome of cell-based cartilage repair. In this study, key functional properties were assessed for cartilage biopsies collected from the central part of traumatic joint lesions (central) and from regions surrounding the defect (peripheral). These properties were then correlated with the quality of the initial cartilage biopsy and the inflammatory state of the joint. DESIGN: Cartilage samples were collected from knee joints of 42 patients with traumatic knee injuries and analyzed for cell phenotype (by reverse transcriptas-polymerase chain reaction), histological quality, cellularity, cell viability, proliferation capacity, and post-expansion chondrogenic capacity of chondrocytes (in pellet culture). Synovium was also harvested and analyzed for the expression of inflammatory cytokines. RESULTS: Cartilage quality and post-expansion chondrogenic capacity were higher in peripheral versus central samples. Differences between these 2 parameters were more pronounced in joints with high inflammatory features characterized by >100-fold difference in the mRNA levels of IL6 and IL8 in the corresponding synovium. Peripheral chondrocytes isolated from good- versus bad-quality biopsies expressed higher levels of collagen II/I and aggrecan/versican and lower levels of MMP13 and ADAMTS5. They also exhibited reduced proliferation and enhanced cartilage-forming capacity. CONCLUSIONS: Chondrocytes at the periphery of traumatic lesions better maintain properties of healthy cartilage compared to those isolated from the center, even when derived from bad-quality tissues harvested from highly inflamed joints. Future studies are necessary to investigate the change of functional properties of peripheral chondrocytes over time.

Patient-reported outcome measures (PROMs) following knee arthroplasty: a prospective cohort study protocol.

INTRODUCTION: To evaluate the quality of clinical practice, patient-reported outcome measures (PROMs) are important as certain questions could only be answered by the patient himself. PROMs help to get a better understanding what is meaningful to a patient and directly affects daily functioning. To move beyond traditional measures, we are interested in what matters to patients and developed this project. The aim of this article is to provide the protocol for our study collecting PROMs in daily medical practice from patients who undergo knee arthroplasty. METHODS AND ANALYSIS: This study is a single-site, observational, prospective cohort study. We will recruit patients scheduled for a knee arthroplasty in our medical office, situated in a private clinic. After signed informed consent, patients complete self-reported questionnaires before the surgery, after 4 months, 1 year, 2 years, 3 years, 4 years and 5 years. We will use the following PROMs: Knee injury and Osteoarthritis Outcome Score, Forgotten Joint Score, EuroQol five dimensions and satisfaction. Additionally, the surgeon will complete the objective Knee Society Score. Administration of the questionnaires will be electronically or paper-based. We will assess differences between preoperative and postoperative data with paired t-test for continuous variables and Wilcoxon signed-rank test for categorical variables. To assess subgroup differences, we will use unpaired t-test for continuous variables and Mann-Whitney U test for categorical variables. To assess possible presence of bias, we will conduct sensitivity analyses. ETHICS AND DISSEMINATION: The study has been reviewed and approved by the local ethics committee in Basel, Switzerland. Written informed consent will be obtained from all patients. We will disseminate the results of the study through peer-reviewed journals, national and international conference presentations and presentations to relevant stakeholders through appropriate channels.

Femoral component malrotation is not correlated with poor clinical outcomes after total knee arthroplasty.

PURPOSE: Proper rotational alignment of the femoral component is critical for a successful total knee arthroplasty (TKA). The aim of this systematic review was to analyse the available literature to examine the effect of the TKA femoral component malrotation on clinical outcomes and assess a cut-off value for femoral rotation leading to revision surgery. METHODS: A detailed and systematic search from 1996 to 2019 of the PUBMED, Medline, Cochrane Reviews and Google Scholar databases had been performed using the keyword terms "total knee arthroplasty OR replacement" AND "femoral alignment OR malalignment OR femoral rotation OR malrotation" AND "clinical outcome". We used the methodological index for non-randomized studies (MINORS) to identify scientifically sound articles in a reproducible format. RESULTS: Eleven articles met inclusion criteria. A total of 896 arthroplasties were included in this review; 409 were unexplained painful TKA patients, while 487 were painless TKA patients. The mean age of patients was 67.5 (± 2.1) years. The mean post-operative follow-up delay was 46.8 (± 32.2) months. The mean of MINORS score was 21 points indicating good methodological quality in the included studies. CONCLUSIONS: The present review confirms that the malrotation of the femoral component in TKA does not correlate automatically to poor clinical and functional outcome. The clinical relevance of this study was that, to improve accuracy in femoral component rotation, surgeons should consider the anatomical variability of femur in each knee and perform additional measurements pre- and intra-operatively. Taking a more accurate approach will shed light on unanswered questions in unhappy TKA. LEVEL OF EVIDENCE: III.

ACL suturing using dynamic intraligamentary stabilisation showing good clinical outcome but a high reoperation rate: a retrospective independent study.

PURPOSE: Most of the clinical outcome studies dealing with ACL repair are from the developer's perspective. It is a fact that these developer-initiated studies tend to interpret the results rather in favour than against their developed technique or product. Hence, it was the purpose of the present independent investigator-initiated study to investigate the clinical and radiological outcomes as well as failure rate of patients who underwent an ACL suture using dynamic intraligamentary stabilisation device in a specialised independent knee clinic. METHODS: A retrospective study was performed on prospectively collected data of 26 patients (28 ± 9 years, range 18-50 years; male/female = 17:9) who underwent biologically augmented ACL suture using dynamic intraligamentary stabilisation. Mean time from ACL injury was 15 ± 5 days (range 4-25 days). In addition, in seven (27%) patients a medial meniscus refixation and in four (15%) patients a lateral meniscus refixation was done for associated meniscal lesions. All patients were clinically and radiologically followed up at 6 weeks, 3 and 12 months after ACL surgery using the Tegner and Lysholm score as well as IKDC score. Adverse events such as ACL failure, arthrofibrosis, pain > 3 on a visual analogue scale as well as the need and type of revision surgery were noted. RESULTS: Four patients (15%) suffered from an ACL retear due to another adequate trauma during follow-up time. In six patients (23%), an arthrofibrosis (extension deficit of > 10° or flexion deficit > 20°) was noted. In five of those six patients, an arthroscopic arthrolysis was performed. Three patients also complained about pain VAS > 3. In nine (35%) patients, superfluous ACL scar tissue and the DIS device including the polyethylene suture and the DIS screw were removed, and in another two (8%) patients, the DIS screw only was removed. In two patients, a partial meniscectomy was performed due to a non-healed meniscal suture. The median Tegner score was 8 (range 6-10) before injury and 7 (range 3-10) at last follow-up (p < 0.001). The mean Lysholm score before surgery was 28 ± 14 and 94 ± 11 at last follow-up (p < 0.001). At last follow-up, 14 patients (66%) showed a normal total IKDC score (A) and 4 patients (19%) were nearly normal (B) and 2 patients (10%) were slightly abnormal (C) and one patient (5%) was entirely abnormal (p < 0.001). CONCLUSION: ACL suturing using the dynamic intraligamentary stabilisation device showed satisfying clinical results at 12-month follow-up. However, a retear rate of 15% and a reoperation rate of 35% due to retear or arthrofibrosis appear rather high. These results highlight the importance of adequate patient selection and the delicacy of the surgical procedure. LEVEL OF EVIDENCE: Retrospective case series, Level IV.

Good clinical results but moderate osseointegration and defect filling of a cell-free multi-layered nano-composite scaffold for treatment of osteochondral lesions of the knee.

PURPOSE: The aim of this retrospective study was to evaluate the clinical and radiological results of a nano-composite multi-layered three-dimensional biomaterial scaffold for treatment of osteochondral lesions (OCL) of the knee. It was a particular radiological interest to analyse the osseointegration, filling of the defects and the bone tracer uptake (BTU), and it was hypothesised that this scaffold, which was created to mimic the entire osteo-cartilaginous unit, is integrated within the bone 12 months postoperatively and comes along with improved patients symptoms and function. METHODS: Fourteen patients (male:female = 11:3, mean age ± SD 33.1 ± 10.7 years) treated for OCL (size 1.0-3.5 cm2) were clinically and radiologically evaluated at 1 year postoperatively. The data were prospectively collected including SPECT/CT, Tegner and Lysholm scores. BTU was anatomically localised and volumetrically quantified in SPECT/CT. Defect filling was analysed in CT. Spearman's rho and Wilcoxon test were used for correlation of BTU in SPECT/CT and clinical scores (p < 0.05). RESULTS: A significant improvement in Lysholm knee score (p < 0.001) and slight deterioration in Tegner score were found (p < 0.01). A complete filling of the defect was shown in 14%, a partial filling in 14% and only minor filling was seen in 72%. A significant correlation (p < 0.001) was found between location of osteochondral lesions and increased BTU. At the lesion sites pre- and postoperative BTU was markedly increased and did not show any decrease at 12-month follow-up. Median Tegner and mean Lysholm scores did not correlate with BTU at any time. CONCLUSIONS: Treatment of OCL in the knee joint with a nano-composite multi-layered three-dimensional biomaterial scaffold resulted in a significant clinical improvement at 1-year follow-up. However, osseointegration was still ongoing at 12-month follow-up. LEVEL OF EVIDENCE: Case series, Level IV.

Effect of high tibial osteotomy on joint loading in symptomatic patients with varus aligned knees: a study using SPECT/CT.

PURPOSE: The purpose was to prospectively evaluate the outcome, in particular the SPECT/CT bone tracer uptake (BTU) after high tibial osteotomy (HTO) due to symptomatic varus malalignment. It was the hypothesis that the BTU after HTO decreases in the medial compartment, clinical outcome and the degree of correction correlates with BTU and asymptomatic patients after HTO reveals a significantly decreased BTU in the medial subchondral areas. METHODS: Twenty-two consecutive patients with 23 knees undergoing medial opening-wedge HTO for medial compartment overloading were assessed pre- and postoperatively (12 and/or 24 months) using Tc-99m-HDP-SPECT/CT including our 4D-SPECT/CT protocol. BTU was quantified and localized to specific biomechanically relevant joint areas. Maximum absolute and relative values (mean ± standard deviation, median and range) for each area were recorded. Pre- and postoperative mechanical alignment was measured. At 24 months after HTO, the WOMAC score was used. RESULTS: A significant decrease of BTU in the medial subchondral zones after HTO was found (preoperatively to 12 and 24 months postoperatively, p < 0.01). BTU normalized in all asymptomatic patients within 24 months. This decrease was partly seen in the lateral compartments, but significantly higher in the medial compartments (p < 0.0001). A significant increase of the BTU was noted in zones directly adjacent to the plate or within the osteotomy zone (p < 0.01). Decreased BTU was observed in osteotomy zones at 24 months postoperatively following higher uptake values at 12 months postoperatively. The average valgus correction of the tibiofemoral angle was 5.9° ± 2.8°. Less stiffness correlated significantly with a higher decrease in BTU (p < 0.05). Higher postoperative BTU significantly correlated with more pain (p < 0.05). No statistical significant associations between BTU and alignment correction were found. CONCLUSION: In patients with medial compartment, overloading due to varus malalignment HTO led to a significant decrease in BTU in the medial joint compartments. SPECT/CT BTU patterns and intensity in these patients pre- to 12 and 24 months postoperatively were seen. These correlated significantly with pain and stiffness. Hence, SPECT/CT could be used for assessment of adequate correction and healing after HTO. SPECT/CT could be further used to identify the optimal individualized correction for each patient and clinical scenario. CLINICAL EVIDENCE: Diagnostic prospective study, Level II.

Assessment of in vivo loading history of the patellofemoral joint: a study combining patellar position, tilt, alignment and bone SPECT/CT.

PURPOSE: The current study investigates whether patella height and tilt or leg alignment influence the intensity values as well as the distribution pattern of single photon emission computerized tomography/computerized tomography (SPECT/CT) tracer uptake in the patellofemoral joint. METHODS: 99mTc-HDP-SPECT/CT and radiographs of consecutive 84 knees were prospectively obtained. Lateral radiographs were analyzed in terms of patellar height, Insall-Salvati index and modified Insall-Salvati index. Skyline views were analyzed for Laurin's lateral patellofemoral angle. On long-leg radiographs, the mechanical leg alignment was classified as varus, valgus or neutral. SPECT/CT was analyzed for each anatomical region using a previously validated SPECT/CT localization and grading algorithm. Mean, standard deviation, minimum and maximum of grading for each area of the localization scheme were recorded. Nonparametric Spearman's correlations were used to correlate patellar height, lateral patellar angle and leg alignment with the tracer uptake intensity. Chi-square statistics were used for categorical data (p < 0.05). RESULTS: A patella baja correlated significantly with higher SPECT/CT tracer uptake in all patellar and lateral femoral regions (p < 0.001). A higher lateral patellar tilt correlated significantly with higher tracer uptake in the superior lateral femoral parts and the tibial tubercle. In mechanically varus aligned knees, there was significantly higher SPECT/CT tracer uptake on the medial and in valgus knees on the lateral part of the patellofemoral joint (p < 0.05). CONCLUSIONS: As the intensity and distribution of the SPECT/CT significantly correlated with patella baja and patellar tilt, SPECT/CT might be considered as imaging modality for evaluating patients with patellofemoral disorders and for follow-up of patients after patellofemoral realignment procedures. LEVEL OF EVIDENCE: Diagnostic study, Level II.

Double incision iso-anatomical ACL reconstruction: the freedom to place the femoral tunnel within the anatomical attachment site without exception.

AIM: The present paper describes the rationale behind the surgical technique and the clinical results of the iso-anatomical, single bundle bone patellar-tendon bone anterior cruciate ligament (ACL) reconstruction. METHOD: Using a second incision on the distal lateral femur an outside-in femoral tunnel is drilled. Guided by a special aiming device it is possible to place the femoral tunnel in the centre of the ACL footprint in every single case. CONCLUSION: Since every crucial step of the procedure is under visual control, the technique is safe and reliable, which is mirrored by good clinical results.

SPECT/CT tracer uptake is influenced by tunnel orientation and position of the femoral and tibial ACL graft insertion site.

PURPOSE: SPECT/CT is a hybrid imaging modality, which combines a 3D scintigraphy (SPECT) and a conventional computerised tomography (CT). SPECT/CT allows accurate anatomical localisation of metabolic tracer activity. It allows the correlation of surgical factors such as tunnel position and orientation with mechanical alignment, clinical outcome and biological factors. The purpose of this study was to investigate whether the SPECT/CT tracer uptake (intensity and distribution) correlates with the stability and laxity of the knee joint and the position and orientation of the tibial and femoral tunnels in patients after anterior cruciate ligament (ACL) reconstruction. METHODS: A consecutive series of knees (n=66), with symptoms of pain and/or instability after ACL reconstruction were prospectively evaluated using clinical examination and 99mTc-HDP-SPECT/CT. Clinical laxity testing was performed using the Rolimeter (Ormed, Freiburg, Germany) including Lachman testing (0-2 mm, 3-5 mm, 6-10 mm, >10 mm), anterior drawer test (0-2 mm, 3-5 mm, 6-10 mm, >10 mm), pivot shift test (positive versus negative) and patient-based subjective instability (yes versus no). For analysis of SPECT/CT tracer uptake a previously validated SPECT/CT localisation scheme consisting of 17 tibial, nine femoral and four patellar regions on standardised axial, coronal, and sagittal slices was used. The tracer activity on SPECT/CT was localised and recorded using a 3D volumetric and quantitative analysis software. Mean, standard deviation, minimum and maximum of grading for each area of the localisation scheme were recorded. The position and orientation of the tibial and femoral tunnel was assessed using a previously published method on 3D-CT. RESULTS: Correlation of instability, pivot shift as well as clinical laxity testing with 99mTc-HDP-SPECT/CT tracer uptake intensity and distribution showed no significant correlation. 99mTc-HDP-SPECT/CT tracer uptake correlated significantly with the position and orientation of the ACL graft. A more horizontal femoral graft position showed significantly increased tracer uptake within the superior and posterior femoral regions. A more posteriorly-placed femoral insertion site showed significantly more tracer uptake within the femoral and tibial tunnel regions. A more vertical or a less medial tibial tunnel orientation showed significant increased uptake within the tibial and femoral tunnel regions. A more anterior tibial tunnel position showed significantly more tracer uptake in the femoral and tibial tunnel regions as well as the entire tibiofemoral joint. CONCLUSIONS: SPECT/CT tracer uptake intensity and distribution showed a significant correlation with the femoral and tibial tunnel position and orientation in patients with symptomatic knees after ACL reconstruction. No correlation was found with stability or clinical laxity. SPECT/CT tracer uptake distribution has the potential to give us important information on joint homeostasis and remodelling after ACL reconstruction. It might help to predict ACL graft failure and improve our surgical ACL reconstruction technique in finding the optimal tunnel and graft position and orientation.