Influence of medial and lateral imaging plane inclination on assessment of trochlear depth, sulcus angle, and facet asymmetry in the setting of trochlear anatomy: a cadaveric study.

PURPOSE: (1) to assess the influence of medial or lateral imaging plane inclination on the measurement of sulcus angle, trochlear depth, and facet asymmetry on transverse cross-sectional images. (2) to assess the effect of measurement level (height) on these respective parameters. MATERIALS AND METHODS: Twenty dry femurs (9 left, 11 right) were imaged with CT. A 3D dataset was obtained from which axial images were reconstructed in the ideal plane without inclination as well as with 8° of medial and lateral inclination. Sulcus angle, trochlear depth, and facet asymmetry were measured on the 3 image sets. In addition, the measurements were performed at 5 mm and 10 mm from the superior margin of the medial trochlear facet. Statistical analysis consisted of the Wilcoxon test and calculation of measurement variation. RESULTS: There were no statistically significant differences between the indicated measurements on the reference set compared to medial or lateral inclination. All measurements were significantly different depending on measurement height. CONCLUSION: Medial or lateral inclination in the transverse imaging plane of 8° does not influence the values of typical parameters used for the assessment of trochlear dysplasia. The measurement height has a significant influence, and a consensus should be found as to which is the optimal measurement height.

Ultrasound of Lipomatosis of Nerve Associated with Macrodactyly: 'Spaghetti and Chocolate Cookie' Appearance.

We studied the US imaging findings of lipomatosis of nerve and macrodystrophia lipoma in three patients. Three patients were seen at three affiliated institutions with an enlarged digit. They all underwent US, subsequently followed by an MRI study. The nerves showed marked enlargement and extension over a length of 9-16 cm. Digital branches were always involved. The appearance on cross section was an enlarged hyperechoic endoneurium with inlying thickened and hypoechoic fascicles. On transverse images this resulted in a 'chocolate cookie' aspect and in the long axis a 'spaghetti-like' image. The US appearance of lipomatosis of nerve, not unlike MRI, is rather typical. With US, care should be taken in areas that are more difficult to assess as the sole of the foot, or where the 'chocolate cookie' appearance is not so obvious, such as the digits.

Outpatient parenteral antibiotic therapy for the treatment of prosthetic knee and hip infections in Belgium, a cost minimization analysis.

OBJECTIVES: Prosthetic joint infections (PJI) are treated with prolonged periods of intravenous (IV) antibiotics combined with one or more appropriate surgical procedures. In Belgium, patients receive their IV treatments as inpatients, whereas in other parts of the world similar IV antibiotics can be given as outpatient parenteral antibiotic therapy (OPAT), without jeopardising patient outcomes. The purpose of this paper was to analyse the financial feasibility of OPAT for PJI in Belgium. METHODS: Patients with PJI treated with a two-stage revision between January 2013 and June 2016 were selected for analysis of in-hospital costs. An OPAT cost simulation was made for comparable lengths of stay, for the different antimicrobial regimens used. A cost minimization analysis comparing the non-OPAT costs and the OPAT cost simulation was performed, with a sensitivity analysis accounting for cost uncertainties. RESULTS: Based on the financial data of 12 two-stage revisions and 4 different antibiotic regimens, the average simulated cost difference for OPAT was €2.402 surplus for the patient, €-25.950 for health care and €-23.548 in total. CONCLUSION: Projected cost savings for OPAT-treatment of PJI are substantial. However, OPAT within the current Belgian system was significantly more expensive for the patients. This can be attributed to the Belgian health insurance system; its current reimbursement regulations prevent OPAT from truly making a breakthrough in Belgium.

Evaluating lower limb kinematics and pathology with dynamic CT.

Evaluating musculoskeletal conditions of the lower limb and understanding the pathophysiology of complex bone kinematics is challenging. Static images do not take into account the dynamic component of relative bone motion and muscle activation. Fluoroscopy and dynamic MRI have important limitations. Dynamic CT (4D-CT) is an emerging alternative that combines high spatial and temporal resolution, with an increased availability in clinical practice. 4D-CT allows simultaneous visualization of bone morphology and joint kinematics. This unique combination makes it an ideal tool to evaluate functional disorders of the musculoskeletal system. In the lower limb, 4D-CT has been used to diagnose femoroacetabular impingement, patellofemoral, ankle and subtalar joint instability, or reduced range of motion. 4D-CT has also been used to demonstrate the effect of surgery, mainly on patellar instability. 4D-CT will need further research and validation before it can be widely used in clinical practice. We believe, however, it is here to stay, and will become a reference in the diagnosis of lower limb conditions and the evaluation of treatment options. Cite this article: Bone Joint J 2021;103-B(5):822-827.

Clinical and Radiographic Outcome of Gap Balancing Versus Measured Resection Techniques in Total Knee Arthroplasty.

BACKGROUND: There is no consensus regarding superiority between gap balancing (GB) and measured resection (MR) techniques to implant total knee arthroplasties. In a multicenter setup, we compared both techniques using the same prosthesis. METHODS: We included 262 balanSys posterior-stabilized total knee arthroplasties from 4 centers: 3 using the MR (n = 162) and one using the GB technique (n = 100), without navigation. RESULTS: There was no significant difference in the Knee Society Score or visual analog scale pain at 2- and 7-year follow-up. The visual analog scale for satisfaction was significantly better in the MR group at 2 but not at 7 years. We found a significantly higher average valgus in the GB group, but the overall alignment was within 2° of neutral on the full-leg radiographs. There were no significant differences concerning radiolucency and survival. CONCLUSIONS: We found no significant differences in the functional outcome, pain, alignment, or survival, but a tendency toward better function using MR and better survival with GB.

Study protocol: a single-blind, multi-center, randomized controlled trial comparing dynamic intraligamentary stabilization, internal brace ligament augmentation and reconstruction in individuals with an acute anterior cruciate ligament rupture: LIBRƎ study.

BACKGROUND: The current gold standard for the treatment of an anterior cruciate ligament (ACL) rupture is reconstruction with tendon graft. Recently, two surgical ACL repair techniques have been developed for treating an acute ACL rupture: Dynamic Intraligamentary Stabilization (DIS, Ligamys®) and Internal Brace Ligament Augmentation (IBLA, InternalBrace™). We will conduct a single-blind, multi-center, randomized controlled trial which compares DIS, IBLA and reconstruction for relative clinical efficacy and economic benefit. METHODS: Subjects, aged 18-50 years, with a proximal, primary and repairable ACL rupture will be included. DIS is preferably performed within 4 weeks post-rupture, IBLA within 12 weeks and reconstruction after 4 weeks post-rupture. Patients are included in study 1 if they present within 0-4 weeks post-rupture and surgery is feasible within 4 weeks post-rupture. Patients of study 1 will be randomized to either DIS or IBLA. Patients are included in study 2 if they present after 4 weeks post-rupture and surgery is feasible between 5 and 12 weeks post-rupture. Patients of study 2 will be randomized to either IBLA or reconstruction. A total of 96 patients will be included, with 48 patients per study and 24 patients per study arm. Patients will be followed-up for 2 years. The primary outcome is change from baseline (pre-rupture) in International Knee Documentation Committee score to 6 months post-operatively. The main secondary outcomes are the EQ-5D-5 L, Tegner score, Lysholm score, Lachman test, isokinetic and proprioceptive measurements, magnetic resonance imaging outcome, return to work and sports, and re-rupture/failure rates. The statistical analysis will be based on the intention-to-treat principle. The economic impact of the surgery techniques will be evaluated by the cost-utility analysis. The LIBRƎ study is to be conducted between 2018 and 2022. DISCUSSION: This LIBRƎ study protocol is the first study to compare DIS, IBLA and ACL reconstruction for relative clinical efficacy and economic benefit. The outcomes of this study will provide data which could aid orthopaedic surgeons to choose between the different treatment options for the surgical treatment of an acute ACL rupture. TRIAL REGISTRATION: This study is registered at ClinicalTrials.gov; NCT03441295. Date registered 13.02.2018.

Treatment of central sensitization in patients with chronic pain: time for change?

Introduction: Given our improved understanding of the role of central sensitization (CS) in many patients with chronic pain, it seems rational to account for CS during treatment. Areas covered: First, the treatment rationale based on the complex mechanisms underlying CS in patients having chronic pain is presented. Second, emphasis is given to explaining the concept of CS when providing treatment, as well as why patients and clinicians should focus on long-term rather than short-term treatment effects. Third, possible pharmacological and non-pharmacological treatment options are discussed. Expert opinion: Centrally acting drugs such as tricyclic compounds, serotonin-norepinephrine reuptake inhibitors, and α2δ ligands each target mechanisms that are often dysfunctional in patients having chronic pain and CS, but decades of clinical practice and clinical trials have not resulted in satisfactory outcomes. This comes as no surprise; CS comprises complex psycho-neuro-immunological interactions, while each of the tested drugs targets one or two of those mechanisms from a purely biomedical viewpoint. Clinicians willing to take CS into account should design an individually tailored multimodal treatment plan comprising pain neuroscience education, cognition-targeted exercise therapy, sleep management, stress management, and/or dietary intervention.

The TRAC-PS dual radius total knee arthroplasty : Disappointing medium and long terms results.

The TRAC prosthesis is a dual radius, mobile bearing, posterior stabilized prosthesis, to increase stability by optimizing contact area and control wear using a mobile polyethylene. Between February 1995 and January 2000, a single surgeon performed a continuous series of 85 TRAC-PS TKAs in 85 patients at the University Hospital Brussels. A retrospective review on patient charts was performed. Patients available were scored clinically using the Knee Society Score, WOMAC osteoarthritis index, SF 36 and a Visual Analogue Scale for pain. 43 patients had died at time of evaluation, three were unavailable for examination due to bad general health and five were lost to follow up. The remaining 35 patients were examined with a mean follow-up of 13 years. The mean age of the patients at follow up was 83 years. The mean WOMAC score was 78,4(SD 17,9). The mean Knee Society Score was 86.8(SD 8,4) clinical and 42,6(SD 28) functional. The mean range of flexion was 105°. The mean SF-36 score was 59,8(SD 15,4). The VAS for pain was 6(SD 9). With revision (8 cases) as endpoint, survival rate of the prosthesis was estimated to be 92% at 13 years. Twenty-three Serious Adverse Events (28%) in 17 patients, related to the prosthesis were registered in this patient group. Long term results of this prosthesis were satisfying but a large number of serious adverse events led to abandonment of the TRAC-prosthesis.

Long-term Subjective, Clinical, and Radiographic Outcome Evaluation of Meniscal Allograft Transplantation in the Knee.

BACKGROUND: Although meniscal allograft transplantation (MAT) has been performed for nearly 30 years, there are few long-term published studies of the technique. HYPOTHESIS/PURPOSE: The goal of this study was to report the long-term results of a patient cohort whose medium-term results have been reported and to evaluate whether the results are maintained in the long term or deteriorate after a certain period. The hypothesis was that the subjective, clinical, and radiographic results are consistent in the long term without significant deterioration. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Thirty patients from the original cohort of 49 patients (50 MATs) who underwent MAT at least 9 years before this study were evaluated with the Knee injury and Osteoarthritis Outcome Score (KOOS); Lysholm, Tegner, and Short Form-36 scores; and a visual analog score for pain. A standardized clinical examination was performed to objectively evaluate knee-related symptoms. Standard weightbearing radiographs, including a full-leg standing radiograph, were performed to evaluate joint space narrowing and any progression of osteoarthritis and malalignment. These results, at a mean follow-up time of 12 years and 8 months (152 months; range, 112-216 months), were compared with the preoperative data and the outcome results at medium-term follow-up (mean, 8 years and 9 months). RESULTS: Of the original 49 patients, 6 (12.2%) required conversion to a total knee arthroplasty during the study period and were considered failures, and 17 (34.7%) required a second surgical procedure during the study period. Excluding the 6 total knee arthroplasty cases, 90% of patients reported being very satisfied or satisfied and would undergo the procedure again. Only 1 patient reported not wanting to undergo the procedure again. Results of the visual analog score, KOOS and all KOOS subscales, Lysholm, and Short Form-36 all showed a statistically significant improvement at estimated follow-up periods of 7.5 and 12.5 years compared with preoperative scores. There was no statistically significant difference for these scores between 7.5 and 12.5 years postoperatively. Despite the improvement in outcome scores, the Tegner activity level score remained unchanged during the entire follow-up period. Regarding radiographic outcomes, there was a progressive increase in the Kellgren-Lawrence rating over the study period. There was a statistically significant (P = .0208) progressive joint space narrowing between estimates at the 7.5-year (5.45 mm) and 12.5-year (4.95 mm) follow-up. However, there was no statistically significant (P = .6724) difference in absolute value of alignment deviation from the 0° mechanical axis between 7.5 years (2.32°) and 12.5 years (2.51°) postoperatively. There was no difference between medial and lateral transplants. CONCLUSION: Despite an increase in joint space narrowing, MAT resulted in significant improvements in pain and functional outcomes over the study period. There was no change in these improvements between the medium- and long-term follow-up period. This study confirms the good and consistent results found in the literature concerning satisfaction, pain resolution, and functional scores at long-term follow-up.

The influence of freezing on the tensile strength of tendon grafts : a biomechanical study.

We investigated the influence of freezing on the tensile strength of fresh frozen tendon grafts. The biomechanical characteristics of tendons that are less commonly used in knee surgery (tibialis anterior, tibialis posterior, peroneus longus and medial and lateral half of Achilles tendons) were compared to those of a semitendinosus and gracilis graft harvested from the same 10 multi-organ donors. All right side tendons constituted the study group and were frozen at -80 degrees C and thawed at room temperature 5 times. All left side tendons were frozen at -80 degrees C and thawed at room temperature once. There were 59 tendons in the control group and 56 in the study group. The looped grafts were clamped at one side using a custom-made freeze clamp and loaded until failure on an Instron 4505 testing machine. The average ultimate failure load was not significantly different between the control and the study group (p > 0.05). The failure load of the medial tendon Achilles was the lowest in both study and control group (p < 0.001). There was no significant difference in maximum stress, maximum displacement, maximum strain and stiffness between the control and study group (p > 0.05). From our study, we conclude that freezing tendons at -80 degrees C and thawing several times does not influence the maximum load, maximum stress, maximum displacement, maximum strain and stiffness. The medial half of the Achilles tendon is clearly the weakest tendon (p < 0.001). These findings show that tendon grafts can be frozen at -80 degrees C and thawed at room temperature several times without altering their biomechanical properties.

Validation of a finite element model of a unilateral external fixator in a rabbit tibia defect model.

In case of large segmental defects in load-bearing bones, an external fixator is used to provide mechanical stability to the defect site. The overall stiffness of the bone-fixator system is determined not only by the fixator design but also by the way the fixator is mounted to the bone. This stiffness is an important factor as it will influence the biomechanical environment to which tissue engineering scaffolds and regenerating tissues are exposed. A finite element (FE) model can be used to predict the system stiffness. The goal of this study is to develop and validate a 3D anatomical FE model of a bone-fixator system which includes a previously developed unilateral external fixator for a large segmental defect model in the rabbit tibia. It was hypothesized that the contact interfaces between bone and fixator screws play a major role for the prediction of the stiffness. In vitro mechanical testing was performed in order to measure the axial stiffness of cortical bone from mid-shaft rabbit tibiae and of the tibia-fixator system, as well as the bending stiffness of individual fixator screws, inserted in bone. µCT-based case-specific FE models of cortical bone and SCREW-BONE specimens were created to simulate the corresponding mechanical test set-ups. The Young's modulus of rabbit cortical bone as well as appropriate screw-bone contact settings were derived from those FE models. We then used the derived settings in an FE model of the tibia-fixator system. The difference between the FE predicted and measured axial stiffness of the tibia-fixator system was reduced from 117.93% to 7.85% by applying appropriate screw-bone contact settings. In conclusion, this study shows the importance of screw-bone contact settings for an accurate fixator stiffness prediction. The validated FE model can further be used as a tool for virtual mechanical testing in the design phase of new tissue engineering scaffolds and/or novel patient-specific external fixation devices.

The Pentaconcept in skeletal tissue engineering. A combined approach for the repair of bone defects.

Tissue engineering has become a hot topic in modern medicine. Its application in a surgical setting, such as for the treatment of skeletal defects, still has to tackle some problems that might look simple at first sight, but need a well-structured handling combining surgery and science, with in a central position the patient, who is both cell donor and receptor of the tissue engineered end product. To achieve this goal in a clinical setting, a five steps pathway is described and designated as the Pentaconcept, integrating all ingredients for successful reconstructive procedures.

Reduction of treatment time in external ring fixation using the monofix device.

One of the disadvantages of the Ilizarov method is the long treatment time needed for extensive lengthening or complex deformity correction. To minimize the discomfort of the circular frame the authors have introduced a 'frame reduction' technique in which the ring frame is converted towards a unilateral fixator, the 'Monofix'. Both its efficacy and patient satisfaction encouraged the authors to apply this method on a routine basis since 1998 for lower and upper limb corrections. The technique is demonstrated, its indications and potential problems are discussed.

Characterized chondrocyte implantation in the patellofemoral joint: an up to 4-year follow-up of a prospective cohort of 38 patients.

BACKGROUND: Autologous chondrocyte implantation (ACI) is an accepted treatment option for selected condylar cartilage defects in the knee. Results for patellofemoral chondral defects have been less favorable. HYPOTHESIS: Autologous chondrocyte implantation with characterized chondrocytes will result in clinically relevant improvement in patellofemoral lesions. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Patients with symptomatic patellofemoral full-thickness cartilage lesions were treated with ACI using characterized chondrocytes (ChondroCelect) covered with a collagen type I membrane. Clinical outcome was assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and a visual analog scale (VAS) for pain. Responders were defined using 5 categories (≥10 points and ≥20%, 30%, 50%, 70%) based on the KOOS and VAS. Treatment failure was defined as partial loosening of more than 20% of the graft with subsequent procedures to the subchondral bone. RESULTS: Thirty-eight patients, with a mean defect size of 4.89 cm(2) (range, 1.5-11 cm(2)), were treated for a patellar defect (n = 28), trochlear defect (n = 7), or a kissing lesion (trochlea and patella; n = 3). The minimum follow-up period was 24 months (mean, 37 months; range, 24-72 months). Treated patients showed statistically significant improvements in the KOOS (at 12, 18, 24, 36, and 48 months) and VAS (at the same time points) compared with pretreatment for each time point. Responder analysis identified approximately 84% of patients with a clinically relevant improvement greater than 10 points at 3 years. Treatment failure was observed in 5 patients. The most commonly reported adverse events were joint crepitation (n = 18) and arthrofibrosis (n = 7). No relationship could be found between clinical outcome and anatomic characteristics of the patellofemoral joint, lesion size and site, time since onset, or age. Nine patients required additional surgery: 6 because of persistent symptoms and 3 for hardware removal. CONCLUSION: Characterized chondrocyte implantation resulted in statistically significant and clinically relevant improvement over time. These results add to the evidence demonstrating that ACI is a valuable cartilage repair technique for patellofemoral lesions.

Tissue engineering approaches for osteoarthritis.

With the ageing of the population and the major advances in targeted drug treatments, there is in medicine a shift in attention from survival towards quality of life. Therefore new challenges are emerging in modern health care. Preventive and personalized medicine have been identified as key steps in this context. New targeted biologicals for musculoskeletal diseases such as chronic arthritis have entered daily clinical practice, thereby not only controlling symptoms and signs, inflammation and destruction, but also maintaining function of the joints. The last aspect is essential for the independence of the individual and critical for the quality of life. Since the lifespan of prosthetic devices will always remain limited, new treatment approaches to repair skeletal structures need to be devised for the young and middle aged individuals with skeletal and joint damage caused by either congenital, traumatic, or inflammatory conditions. It is believed that regenerative medicine and more specifically tissue engineering may fill this void to some extent. Indeed, recent cellular therapeutics and combination products, now resorting under a new regulatory class of Advanced Medicinal Therapeutic Products, provide indications that progress is being made with clinically relevant outcomes in well-defined patient populations. For osteoarthritis, a joint disease leading to joint decompensation, novel tissue engineering therapies are being explored and, although most of the developments are still in early phase clinical studies, there are sufficient positive signals to pursue these novel therapeutic approaches in clinics. This article is part of a Special Issue entitled "Osteoarthritis".

Clinical Outcomes of Characterized Chondrocyte Implantation.

OBJECTIVE: To assess the clinical outcome of patients treated with autologous chondrocyte implantation using ChondroCelect in daily practice. METHODS: The study is a cross-sectional analysis of an open-label, noninterventional cohort. The setting was a compassionate use program, involving 43 orthopaedic centers in 7 European countries. The participants were patients treated with ChondroCelect between October 13, 2004 and July 2, 2008. The measurements used were Clinical Global Impression-Improvement and -Efficacy and solicited adverse event reports. RESULTS: Safety data were collected from 334 patients (90.3%), and effectiveness data were from 282 (76.2%) of the 370 patients treated. Mean age at baseline was 33.6 years (range, 12-57 years), 57% were male, and mean body mass index was 25 kg/m(2). Mean follow-up was 2.2 years (range, 0.4-4.1 years). A femoral condyle lesion was reported in 66% (288/379) and a patellar lesion in 19% (84/379). Mean lesion size was 3.5 cm(2); a collagen membrane was used in 92.4% (328/355). A therapeutic effect was reported in 89% (234/264) of patients overall and in 87% (40/46) of patellar lesion patients. Rates of much or very much improved patients were similar in patients with short- (<18 months: 71% [115/163]) and long-term follow-up (>18 months: 68% [70/103]) (P = 0.68) and were independent of lesion size (>4 cm(2): 75.5% [37/49]; ≤4 cm(2): 67.7% [111/164]) (P = 0.38). Adverse events were similar to those reported in the randomized trial with the same product, with more arthrofibrosis, more reduced joint mobility, and more crepitations reported in patellar lesions. Overall, less cartilage hypertrophy was noted, probably due to the use of a biological membrane cover. CONCLUSIONS: Implantation of ChondroCelect appeared to result in a positive benefit/risk ratio when used in an unselected heterogenous population, irrespective of the follow-up period, lesion size, and type of lesion treated.

Five-year outcome of characterized chondrocyte implantation versus microfracture for symptomatic cartilage defects of the knee: early treatment matters.

BACKGROUND: Characterized chondrocyte implantation (CCI) results in significantly better early structural tissue regeneration than microfracture (MF), and CCI has a midterm clinical benefit over microfracture. PURPOSE: This study was undertaken to evaluate the 5-year clinical outcome of CCI in a randomized comparison with MF for the treatment of symptomatic cartilage defects of the femoral condyles of the knee. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: Participants aged 18 to 50 years with a symptomatic isolated International Cartilage Repair Society (ICRS) grade III or IV cartilage lesion of the femoral condyles between 1 and 5 cm(2) were randomized to either CCI or MF. Clinical outcomes were measured up to 60 months after surgery using the Knee Injury and Osteoarthritis Outcome Score (KOOS). The main outcome parameter was change from baseline in overall KOOS (oKOOS). Adverse events were monitored. RESULTS: Fifty-one participants were treated with CCI and 61 with MF. On average, clinical benefit was maintained through the 60-month follow-up period. The average change from baseline in oKOOS was not different between both groups (least squares [LS] mean ± standard error [SE] 18.84 ± 3.58 for CCI vs 13.21 ± 5.63 for MF; P = .116). Treatment failures were comparable (n = 7 in CCI vs n = 10 in MF), although MF failures tended to occur earlier. Subgroup analysis revealed that CCI resulted in better outcome in participants with time since symptom onset of less than 3 years, which was statistically significant and clinically relevant (change in oKOOS <3 years mean ± SE 25.96 ± 3.45 for CCI vs 15.28 ± 3.17 for MF; P = .026 vs oKOOS >3 years mean ± SE 13.09 ± 4.78 for CCI vs 17.02 ± 4.50 for MF, P = .554). Other subgroup analyses such as age (cutoff 35 years) did not show a difference. Female patients showed more failures irrespective of treatment. CONCLUSION: At 5 years after treatment, clinical outcomes for CCI and MF were comparable. In the early treatment group, CCI obtained statistically significant and clinically relevant better results than MF. Delayed treatment resulted in less predictable outcomes for CCI. These results provide strong evidence that time since onset of symptoms is an essential variable that should be taken into account in future treatment algorithms for cartilage repair of the knee.

Implementing one standardized rehabilitation protocol following autologous chondrocyte implantation or microfracture in the knee results in comparable physical therapy management.

OBJECTIVE: The major aim of the study was (1) to compare the physiotherapy management in patients treated with autologous chondrocyte implantation (ACI) versus microfracture (MF) at the knee using a standardized rehabilitation protocol; and (2) to investigate the effect of activities in low-load conditions after surgery on the functional recovery was explored. DESIGN: 95 physiotherapists received a standardized rehabilitation protocol that was used in a randomized controlled trial. A secondary analysis on patients' outcome was studied in a cohort design. OUTCOME MEASURES: An electronic report form including 18 physiotherapy variables was used to compare physiotherapy management. Patients' functional outcome was assessed using the KOOS (Knee Injury Osteoarthritis Outcome Score) and the pooled symmetry index (SI) based on one strength and three hop tests. Both subjective and objective outcomes were evaluated pre-surgery, and at 1 and 2 years post-surgery. RESULTS: 65 physiotherapists adhered very consistently to the protocol during the first 3 months and showed a similar preference and timing for the physiotherapy modalities in both treatment groups. Patients with high amount of low-load activities (LLA+, n=21) post-surgery performed significantly better compared to patients with low amount of LLA (LLA-, n=17). At 24 months the mean pooled SI of LLA+ cohort was 92.4 compared to 78.2 for LLA- cohort (95% confidence interval [CI] 1.8 to 26.2). CONCLUSION: Overall, the compliance post-surgery with the rehabilitation protocol was excellent and the applied rehabilitation was comparable in both treatment groups. A high amount of low-load activities post-surgery appears beneficial for the objective functional outcome.

The cost utility of autologous chondrocytes implantation using ChondroCelect® in symptomatic knee cartilage lesions in Belgium.

BACKGROUND: Knee cartilage lesions increase the risk of developing osteoarthritis (OA), and may eventually result in a total knee replacement (TKR). There is currently no consensus on the optimal treatment of cartilage lesions. ChondroCelect® (CC) is a cell-based therapy approved for use in autologous chondrocytes implantation (ACI) to treat symptomatic cartilage defects of the femoral condyle. Its capacity to safely restore good-quality cartilage was demonstrated in a randomized controlled trial (RCT) versus the surgical procedure microfracture (MFX). OBJECTIVE: This study investigated the cost utility of CC used in ACI compared with MFX to treat symptomatic knee cartilage lesions in Belgium. METHODS: A decision tree model comparing CC with MFX over a 40-year horizon was developed in TreeAge Pro™. The key timepoints of the model were (i) clinical assessment 5 years after initial intervention (success or no success, with or without re-operation); (ii) development of OA at 15 years (yes/no); (iii) need for TKR at 20 years (yes/no); and (iv) need for prosthesis revision at 35 years (yes/no). Clinical data provided by the RCT of CC versus MFX were the clinical success (response) rate based on the Knee injury and Osteoarthritis Outcome Score (KOOS) at 36 months (82.9% vs 62.0%; p = 0.048) and the proportion of good structural repair/presence of hyaline cartilage based on International Cartilage Repair Society (ICRS II) visual item at 12 months (44.9% vs 23.2%; p = 0.023). Utility scores by surgery outcome were derived from the SF-36 questionnaire responses collected in the RCT. Conservative assumptions related to the incidences of OA, TKR and prosthesis revision relied on a literature search. A patient chart review (n = 82) provided follow-up costs by surgery outcome. National tariffs were applied to direct medical resources used (healthcare payer perspective, year 2008 costs). Annual discounting was applied to costs (3%) and effects (1.5%) as recommended by the Belgian pharmacoeconomic guidelines. RESULTS: The incremental cost per QALY gained for CC compared with MFX was €16,229, with a difference in costs of €20,802 and 1.282 QALYs gained. Sensitivity analyses indicated that the key model drivers were the proportion of patients with hyaline cartilage and the correlation between hyaline cartilage formation and later avoidance of OA. Probabilistic sensitivity analyses showed robustness of the results, with 80% of the simulations below the usual UK National Institute for Health and Clinical Excellence (NICE) threshold of €22,000 per QALY. CONCLUSIONS: Assuming a good correlation between high-quality cartilage repair and avoidance of OA at a later stage, the benefits of the cell therapy CC over MFX in terms of QALYs gained and OA-related costs avoided appear real. Further research is required to explore long-term effects of cartilage repair and reduce uncertainty on quality of life of patients with OA before and after joint replacement.

Arthroscopically assisted meniscal allograft transplantation in the knee: a medium-term subjective, clinical, and radiographical outcome evaluation.

BACKGROUND: Allograft meniscal transplantation is known as a possible procedure to solve pain and loss of function in the knee of patients with a history of subtotal or total meniscectomy. PURPOSE: This work was undertaken to evaluate, using subjective questionnaires and clinical and radiographical scores, patients who underwent an arthroscopically assisted meniscal allograft transplantation with a minimum follow-up between 5 and 15 years (range, 62-169 months). STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Demographic data of 49 patients (50 meniscal allograft transplantations) were collected. At the latest follow-up visit, the authors collected preoperative and follow-up Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm, Tegner, and Short Form 36 (SF-36) scores, and visual analog scale (VAS) scores for pain for comparison. Patients were also evaluated with a standardized clinical examination of the knee to objectively evaluate knee-related symptoms. Standard weightbearing radiographs and a full-leg standing radiograph were performed to evaluate the progression of osteoarthritis and malalignment. RESULTS: Five patients underwent total knee replacement and were considered failures, 8 patients could only be contacted by phone, and 2 patients were lost to follow-up, so 34 patients underwent the complete study protocol (except for 1 patient who did not have a radiographical evaluation because of pregnancy). The study group consisted of 18 men and 16 women, with a mean age of 33 years at the moment of transplantation and with an average follow-up of 8 years and 9 months. There were only a few concomitant procedures. There was a significant (P < .001) and clinically relevant decrease in the VAS (7 to 3.4) and increase in KOOS (35.8 to 60.2), Lysholm (39.7 to 71.8), and total SF-36 (51.5 to 75.2) from preoperative mean score to postoperative mean score. This improvement stayed consistent during the follow-up period. Despite this improvement, there was no increase in Tegner activity level (P = .604). The more severe the osteoarthritis, the less the improvement. There was a significant (P < .001) increase in osteoarthritis in 42% of the patients (14 of 33), as scored following the Kellgren-Lawrence classification. When strictly respecting the indications, there was no significant correlation between preoperative cartilage damage, preoperative osteoarthritis, alignment deviation, gender, and body mass index and the outcome scores or improvement. In this series, with few concomitant procedures, there was no difference in outcome between medial and lateral transplants. CONCLUSION: Meniscal allograft transplantation may result in important pain relief and functional improvement in patients with a history of (sub)total meniscectomy and pain localized in the affected compartment. Strictly following the indications, meniscal transplantation can give good and predictable results. In 58% of patients, there was no increase in osteoarthritis according to the Kellgren-Lawrence classification. In 42%, there was a slight or moderate increase in osteoarthritis. No severe increase was noted.