Incidence of Total Knee Arthroplasty After Arthroscopic Surgery for Knee Osteoarthritis: A Secondary Analysis of a Randomized Clinical Trial.

Importance: It is unclear whether arthroscopic resection of degenerative knee tissues among patients with osteoarthritis (OA) of the knee delays or hastens total knee arthroplasty (TKA); opposite findings have been reported. Objective: To compare the long-term incidence of TKA in patients with OA of the knee after nonoperative management with or without additional arthroscopic surgery. Design, Setting, and Participants: In this ad hoc secondary analysis of a single-center, assessor-blinded randomized clinical trial performed from January 1, 1999, to August 31, 2007, 178 patients were followed up through March 31, 2019. Participants included adults diagnosed with OA of the knee referred for potential arthroscopic surgery in a tertiary care center specializing in orthopedics in London, Ontario, Canada. All participants from the original randomized clinical trial were included. Data were analyzed from June 1, 2021, to October 20, 2022. Exposures: Arthroscopic surgery (resection or debridement of degenerative tears of the menisci, fragments of articular cartilage, or chondral flaps and osteophytes that prevented full extension) plus nonoperative management (physical therapy plus medications as required) compared with nonoperative management only (control). Main Outcomes and Measures: Total knee arthroplasty was identified by linking the randomized trial data with prospectively collected Canadian health administrative datasets where participants were followed up for a maximum of 20 years. Multivariable Cox proportional hazards regression models were used to compare the incidence of TKA between intervention groups. Results: A total of 178 of 277 eligible patients (64.3%; 112 [62.9%] female; mean [SD] age, 59.0 [10.0] years) were included. The mean (SD) body mass index was 31.0 (6.5). With a median follow-up of 13.8 (IQR, 8.4-16.8) years, 31 of 92 patients (33.7%) in the arthroscopic surgery group vs 36 of 86 (41.9%) in the control group underwent TKA (adjusted hazard ratio [HR], 0.85 [95% CI, 0.52-1.40]). Results were similar when accounting for crossovers to arthroscopic surgery (13 of 86 [15.1%]) during follow-up (HR, 0.88 [95% CI, 0.53-1.44]). Within 5 years, the cumulative incidence was 10.2% vs 9.3% in the arthroscopic surgery group and control group, respectively (time-stratified HR for 0-5 years, 1.06 [95% CI, 0.41-2.75]); within 10 years, the cumulative incidence was 23.3% vs 21.4%, respectively (time-stratified HR for 5-10 years, 1.06 [95% CI, 0.45-2.51]). Sensitivity analyses yielded consistent results. Conclusions and Relevance: In this secondary analysis of a randomized clinical trial of arthroscopic surgery for patients with OA of the knee, a statistically significant association with delaying or hastening TKA was not identified. Approximately 80% of patients did not undergo TKA within 10 years of nonoperative management with or without additional knee arthroscopic surgery. Trial Registration: ClinicalTrials.gov Identifier: NCT00158431.

The rate of unnecessary interventions for the management of knee osteoarthritis: a population-based cohort study.

BACKGROUND: Several commonly used procedures for knee osteoarthritis (OA) are not supported by evidence-based guidelines. The objective of this study was to identify the proportion of patients who underwent knee arthroscopy or magnetic resonance imaging (MRI) and the timing of these procedures before total knee arthroplasty (TKA). METHODS: We conducted a retrospective cohort study using administrative data sets from Ontario, Canada. We identified the proportion of patients who underwent knee arthroscopy in the previous 10 years or an MRI in the 3 years before their primary TKA. We also evaluated the rate of arthroscopies by diagnosis. We report the timing of each outcome in relation to the TKA, rates by geographical area, and differences in rates over time. RESULTS: We included 142 275 patients, of whom 36 379 (25.57%) underwent knee arthroscopy (median time 2.8 [interquartile range (IQR) 1.1-6.0] years); 22% of those were within 1 year of TKA and 52% were within 3 years. The rates of arthroscopies for a diagnosis of osteoarthritis (OA) steadily decreased, while those for meniscal-related diagnoses increased over the study period (p < 0.0001). There was significant variation by region. Of the cohort, 23.2% (n = 32 989) had an MRI before their TKA, with rates significantly increasing over time (p < 0.0001). CONCLUSION: A substantial proportion of patients with knee OA received diagnostic and therapeutic interventions before TKA that are contrary to clinical practice guidelines.

A qualitative dominant mixed methods exploration of novel educational material for patients considering total knee arthroplasty.

PURPOSE: To optimize non-operative management and decision making surrounding TKR we created educational whiteboard videos for patients with knee OA. The purpose of this study was to pilot our educational videos with end-users (patients) to determine patients' experiences and perspectives regarding the content and clarity of videos and to better understand their potential impact on patient's health behaviour. MATERIALS AND METHODS: This was a mixed methods evaluation, using a qualitative descriptive approach, of patients attending their first consultation with an arthroplasty surgeon for TKR. We conducted in-depth semi-structured interviews with patients. Three members of the research team coded data independently, implementing a thematic analysis. RESULTS: Thirteen participants were included. Participants indicated that the videos enhanced their confidence and clarity surrounding their decision to undergo TKR. The videos also addressed several knowledge gaps in their understanding of OA management. Barriers to uptake of the education were identified including limited access to PTs and the challenge of weight loss. Conclusions: The current educational intervention was valued by patients with knee OA. Implementation of these videos may have important implications for patients, providers, and our health care system.IMPLICATIONS FOR REHABILITATIONPatients with knee OA referred by primary care physicians to arthroplasty surgeons have knowledge gaps that may influence their self-management and decision making surrounding their condition.Educational materials can address these gaps and support patients in their understanding and management of their condition, which may have important downstream implications.Barriers to accessing non-operative care including physiotherapy must be pre-emptively addressed to ensure that enhanced knowledge is met with improved access for patients.

High Tibial Osteotomy: An Update for Radiologists.

High tibial osteotomy (HTO) is a surgical procedure to treat symptomatic unicompartmental osteoarthritis (OA) associated with knee malalignment. There has been a recent resurgence of interest in HTO in patients who prefer joint-preserving surgery because HTO shifts the knee's mechanical axis from the arthritic compartment to a neutral position, thereby reducing knee pain, slowing progression of OA, and delaying the need for a total knee arthroplasty. The ideal candidates for HTO are patients who are young, active, and nonobese who have isolated varus deformity of the knee resulting from medial compartment OA. Radiography is critical in the preoperative evaluation for HTO and can help expand surgical indications to include a wider variety of patients. Radiography is also routinely obtained in postoperative assessment and is typically the first test to indicate complications. This review describes the radiologic aspects of HTO, including preoperative imaging assessment and normal and abnormal postoperative imaging appearances. Surgical techniques and osteotomy fixation devices are described, with a focus on the medial opening wedge approach. Given the growing interest in HTO, radiologists should become familiar with the basics of the procedure and the role of imaging in preoperative and postoperative evaluation.

Wait times, resource use and health-related quality of life across the continuum of care for patients referred for total knee replacement surgery.

Background: The escalating socioeconomic burden of knee osteoarthritis (OA) underscores the need for innovative strategies to reduce wait times for total knee arthroplasty (TKA). The purpose of this study was to evaluate resource use, costs and health-related quality of life (HRQoL) across the continuum of care for patients with knee OA. Methods: This was a prospective study of 383 patients recruited from a high-volume teaching hospital at different stages of care (referral, consultation and presurgery). Outcomes included health care resource use; costs captured from the health care payer, private sector and societal perspectives; HRQoL measured using the Western Ontario and McMaster Universities Osteoarthritis Index, the 12-Item Short Form Health Survey, and EuroQoL 5-Dimension 5-Level tool; wait times; and the proportion of referrals deemed suitable candidates for surgery. Results: The most commonly used conservative treatments were pharmacotherapy, exercise and lifestyle modification. Forty percent of patients referred for TKA were deemed not to be suitable candidates for surgery. The greatest proportion of costs was borne by the patient or private insurer; a small proportion was borne by the public payer. Across all stages of care, more than 60% of the total costs was attributed to productivity losses. HRQoL remained relatively stable throughout the waiting period (mean wait time from referral to TKA 13.2 mo) but improved postoperatively. Conclusion: The suboptimal primary care management of knee OA calls for the development of innovative models of care. This study may provide valuable guidance on the design and implementation of a new online educational platform to improve referral efficiency and expedite wait times for TKA.

Contexte: Le fardeau socioéconomique croissant de l'arthrose du genou rappelle que nous avons besoin de stratégies novatrices afin de réduire les temps d'attente pour l'arthroplastie totale du genou (ATG). Le but de cette étude est d'évaluer l'utilisation des ressources, les coûts et la qualité de vie liée à la santé (QVLS) dans tout le continuum des soins pour les patients souffrant d'arthrose du genou. Méthodes: Cette étude prospective a porté sur 383 patients recrutés dans un établissement d'enseignement fort achalandé, qui en étaient à différentes étapes du continuum de soins (demande de consultation, consultation et préchirurgie). Les paramètres incluaient l'utilisation des ressources en santé, les coûts du point de vue sociétal et des régimes d'assurance maladie publics et privés, la QVLS mesurée au moyen de l'indice WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index), du questionnaire Short Form Health Survey en 12 points et de l'outil EuroQoL appliqué à 5 dimensions et à 5 niveaux, les temps d'attente, et la proportion de demandes de consultation concernant des patients considérés comme de bons candidats à la chirurgie. Résultats: Les traitements conservateurs les plus utilisés étaient la pharmacothérapie, l'exercice et les modifications à l'hygiène de vie. Quarante pour cent des patients adressés en consultation pour ATG ont été considérés comme de bons candidats à la chirurgie. La plus grande part des coûts a été assumée par le patient ou un assureur privé; une faible part des coûts a été assumée par le régime public. À toutes les étapes du continuum, plus de 60 % des coûts totaux ont été attribués à des pertes de productivité. La QVLS est demeurée relativement stable tout au long de la période d'attente (temps d'attente moyen entre la consultation et l'ATG, 13,2 mois) mais s'est améliorée après la chirurgie. Conclusion: La prise en charge sous-optimale de l'arthrose du genou en soins primaires rappelle qu'il est nécessaire d'établir des modèles de soins novateurs. Cette étude pourrait faciliter la mise au point et l'application d'une nouvelle plateforme éducative en ligne pour améliorer l'efficience des demandes de consultation et abréger les temps d'attente pour l'ATG.

Total knee replacement after high tibial osteotomy: time-to-event analysis and predictors.

BACKGROUND: An important aim of high tibial osteotomy (HTO) is to prevent or delay the need for total knee replacement (TKR). We sought to estimate the frequency and timing of conversion from HTO to TKR and the factors associated with it. METHODS: We prospectively evaluated patients with osteoarthritis (OA) of the knee who underwent medial opening wedge HTO from 2002 to 2014 and analyzed the cumulative incidence of TKR in July 2019. The presence or absence of TKR on the HTO limb was identified from the orthopedic surgery reports and knee radiographs contained in the electronic medical records for each patient at London Health Sciences Centre. We used cumulative incidence curves to evaluate the primary outcome of time to TKR. We used multivariable Cox proportional hazards analysis to assess potential preoperative predictors including radiographic disease severity, malalignment, correction size, pain, sex, age, body mass index (BMI) and year of surgery. RESULTS: Among 556 patients who underwent 643 HTO procedures, the cumulative incidence of TKR was 5% (95% confidence interval [CI] 3%-7%) at 5 years and 21% (95% CI 17%-26%) at 10 years. With the Cox proportional hazards multivariable model, the following preoperative factors were significantly associated with an increased rate of conversion: radiographic OA severity (adjusted hazard ratio [HR] 1.96, 95% CI 1.12-3.45), pain (adjusted HR 0.85, 95% CI 0.75-0.96)], female sex (adjusted HR 1.67, 95% CI 1.08-2.58), age (adjusted HR 1.50 per 10 yr, 95% CI 1.17-1.93) and BMI (adjusted HR 1.31 per 5 kng/m2, 95% CI 1.12-1.53). INTERPRETATION: We found that 79% of knees did not undergo TKR within 10 years after undergoing medial opening wedge HTO. The strongest predictor of conversion to TKR is greater radiographic disease at the time of HTO.

Trends in knee arthroscopy utilization: a gap in knowledge translation.

PURPOSE: To evaluate the longitudinal trends in knee arthroscopy utilization in relation to published negative randomized controlled trials, focusing on annual rates, patient demographics and associated 30-day post-operative complications. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was queried using Current Procedural Terminology billing codes to identify arthroscopy cases between 2006 and 2016. 30-day post-operative complications were identified, and potential risk factors analysed using univariate and multivariate analyses. RESULTS: 68,346 patients underwent knee arthroscopy, of which 47,446 (69.5%) represented partial meniscectomies. The annual procedural rate, as a proportion of all reported cases, increased significantly from 2006 (0.3%) to 2016 (1.6%; p < 0.001), along with a significant increase in average patient age (44.3 ± 15.5 to 48.4 ± 14.5; p < 0.001). Specifically focusing on the meniscectomy cohort, average patient age significantly increased from 47.9 ± 15.1 to 50.7 ± 13.5 (p = 0.001). The overall incidence of complications was 2.0% (n = 1333), with major complications in 0.9% (n = 639) and minor complications in 1.0% (n = 701). Common complications included a return to the operating room (0.5%), deep vein thrombosis/thrombophlebitis (0.4%), and superficial infection (0.2%). Operating time > 90 min, diabetes, steroid use, ASA class 2+, and dialysis-dependency were the predictors of overall complication rates. CONCLUSION: Despite the publication of negative trials and new clinical practice guidelines, knee arthroscopy utilization and average patient age continue to increase. Given the high utilization, even low adverse event rates equate to substantial numbers of patients with minor and major complications. The NSQIP data show a gap in knowledge translation to clinical practice and highlight the need for improved clinical guidelines. LEVEL OF EVIDENCE: Cohort study; Level III.

Validation of a novel blinding method for measuring postoperative knee articular cartilage using magnetic resonance imaging.

OBJECTIVES: To test PEEK implant-associated MRI artifacts, a method for blinding MRI readers, the repeatability of cartilage thickness measures before and 6 weeks after high tibial osteotomy (HTO), and the sensitivity to change of cartilage thickness 12 months after HTO. MATERIALS AND METHODS: Ten patients underwent HTO using a PEEK implant and 3 T-MRI before, 6 weeks and 12 months after surgery. Masks were applied to hide implant visibility on 48 MRI pairs, which were assessed by 7 readers (blinded to time). One blinded reader measured femorotibial cartilage thickness from masked MRIs. RESULTS: No artifacts were produced. Readers were unable to identify scans by time greater than by chance. Cartilage thickness before and 6 weeks after surgery was not significantly different and indicated excellent repeatability. Medial cartilage thickness increases 12 M postoperatively approached statistical significance (p = 0.06), with no lateral changes observed. Half of the participants had an increase in medial cartilage thickness at 12 M that exceeded the minimal detectable change. Standardized response mean values were moderate-to-large. DISCUSSION: Postoperative measures of cartilage thickness are repeatable, consistent and sensitive to change when artifact is eliminated, and a validated blinding technique is used. These results provide proof of concept for accurately measuring increases in medial knee articular cartilage after medial opening wedge HTO.

Improved Methods to Measure Outcomes After High Tibial Osteotomy.

Observational studies suggest high tibial osteotomy produces substantial improvements in knee loading and stability that can limit the progression of joint damage; decrease pain; improve function and quality of life; and delay the need for knee replacement surgery. It can be cost-effective in knee osteoarthritis. However, systematic reviews and clinical practice guidelines are unable to provide strong recommendations, because limited high-level evidence supports its therapeutic value versus other treatments. We describe findings suggesting it can improve outcomes important to knee joint structure and function, patient quality of life, and health care systems. Future clinical trials are warranted and required.

The importance of costing perspective: an example evaluating the cost-effectiveness of a locking versus nonlocking plate in medial opening wedge high tibial osteotomy

Summary: High tibial osteotomy (HTO) fixation can be achieved using various plate designs. Compared with nonlocking plates, the stability of locking plates allows patients to return to weight-bearing and work sooner and may also decrease postoperative complications, introducing the potential for overall cost savings. However, material costs for locking plates are higher, and the plate bulkiness may lead to additional surgery to remove the plate. We conducted a retrospective study to evaluate the cost-effectiveness of a locking versus a nonlocking plate in HTO from both the health care payer and societal perspectives up to 12 months postoperative. We observed that from a health care payer perspective, the locking plate was not cost-effective. However, the locking plate was cost-effective from the societal perspective (addition of indirect costs, such as time off work). These findings highlight the importance of considering costing perspective in economic evaluations for chronic conditions, particularly in publicly funded health care systems.

Correction to: A case series of lateral opening wedge high tibial osteotomy for valgus malalignment.

Unfortunately, one of the co-author affiliation was incorrect in the original publication of this article. The correct affiliation is given below: Abdulaziz Z. Alomar, King Khalid University Hospital, College of Medicine, King Saud University, Riyadh, Saudi Arabia.

Cost-effectiveness analysis of arthroscopic surgery compared with non-operative management for osteoarthritis of the knee.

OBJECTIVE: To determine the cost-effectiveness of arthroscopic surgery in addition to non-operative treatments compared with non-operative treatments alone in patients with knee osteoarthritis (OA). DESIGN, SETTING AND PARTICIPANTS: We conducted an economic evaluation alongside a single-centre, randomised trial among patients with symptomatic, radiographic knee OA (KL grade ≥ 2). INTERVENTIONS: Patients received arthroscopic debridement and partial resection of degenerative knee tissues in addition to optimised non-operative therapy, or optimised non-operative therapy only. MAIN OUTCOME MEASURES: Direct and indirect costs were collected prospectively over the 2-year study period. The effectiveness outcomes were the Western Ontario McMaster Osteoarthritis Index (WOMAC) and quality-adjusted life years (QALYs). Cost-effectiveness was estimated using the net benefit regression framework considering a range of willingness-to-pay values from the Canadian public payer and societal perspectives. We calculated incremental cost-effectiveness ratios and conducted sensitivity analyses using the extremes of the 95% CIs surrounding mean differences in effect between groups. RESULTS: 168 patients were included. Patients allocated to arthroscopy received partial resection and debridement of degenerative meniscal tears (81%) and/or articular cartilage (97%). There were no significant differences between groups in use of non-operative treatments. The incremental net benefit was negative for all willingness-to-pay values. Uncertainty estimates suggest that even if willing to pay $400,000 to achieve a clinically important improvement in WOMAC score, or ≥$50,000 for an additional QALY, there is <20% probability that the addition of arthroscopy is cost-effective compared with non-operative therapies only. Our sensitivity analysis suggests that even when assuming the largest treatment effect, the addition of arthroscopic surgery is not economically attractive compared with non-operative treatments only. CONCLUSIONS: Arthroscopic debridement of degenerative articular cartilage and resection of degenerative meniscal tears in addition to non-operative treatments for knee OA is not an economically attractive treatment option compared with non-operative treatment only, regardless of willingness-to-pay value. TRIAL REGISTRATION NUMBER: NCT00158431.

The development and validation of a multivariable model to predict whether patients referred for total knee replacement are suitable surgical candidates at the time of initial consultation.

BACKGROUND: In previous studies, 50%-70% of patients referred to orthopedic surgeons for total knee replacement (TKR) were not surgical candidates at the time of initial assessment. The purpose of our study was to identify and cross-validate patient self-reported predictors of suitability for TKR and to determine the clinical utility of a predictive model to guide the timing and appropriateness of referral to a surgeon. METHODS: We assessed pre-consultation patient data as well as the surgeon's findings and post-consultation recommendations. We used multivariate logistic regression to detect self-reported items that could identify suitable surgical candidates. RESULTS: Patients' willingness to undergo surgery, higher rating of pain, greater physical function, previous intra-articular injections and patient age were the factors predictive of patients being offered and electing to undergo TKR. CONCLUSION: The application of the model developed in our study would effectively reduce the proportion of nonsurgical referrals by 25%, while identifying the vast majority of surgical candidates (> 90%). Using patient-reported information, we can correctly predict the outcome of specialist consultation for TKR in 70% of cases. To reduce long waits for first consultation with a surgeon, it may be possible to use these items to educate and guide referring clinicians and patients to understand when specialist consultation is the next step in managing the patient with severe osteoarthritis of the knee.

CONTEXTE: Dans des études précédentes, de 50 % à 70 % des patients dirigés vers des chirurgiens orthopédistes pour une arthroplastie totale du genou (ATG) n'étaient pas des candidats à la chirurgie au moment de l'évaluation initiale. Notre étude visait à recenser et à contrevalider les facteurs prédictifs de l'opportunité d'une ATG fondés sur des renseignements fournis par les patients, ainsi qu'à déterminer l'utilité clinique d'un modèle de prévision qui évaluerait le moment et la pertinence de diriger un patient vers un chirurgien. MÉTHODES: Nous avons évalué les données des patients préconsultation ainsi que les conclusions du chirurgien et ses recommandations postconsultation. Nous avons mené une analyse de régression logistique multivariée pour détecter les éléments autodéclarés qui permettraient de reconnaître les candidats pour la chirurgie. RÉSULTATS: Les facteurs permettant de prédire si un patient se ferait offrir une ATG et choisirait de subir l'intervention étaient la disposition favorable du patient à se faire opérer, une douleur d'intensité élevée, des capacités physiques fonctionnelles supérieures, des antécédents d'injections intra-articulaires et l'âge. CONCLUSION: Concrètement, l'application du modèle élaboré durant notre étude réduirait le nombre de patients dirigés vers un chirurgien sans motif valable dans une proportion de 25 %, tout en permettant de reconnaître la vaste majorité des candidats à la chirurgie (> 90 %). À partir des renseignements fournis par les patients, nous pouvons prédire correctement le résultat d'une consultation avec un spécialiste pour une ATG dans 70 % des cas. Les conclusions de notre étude pourraient servir à réduire les longs délais d'attente pour une première consultation avec un chirurgien en aidant les professionnels de la santé et les patients à déterminer quand il convient de consulter un spécialiste pour la prise en charge d'une gonarthrose grave.

Medial opening wedge high tibial osteotomy alters knee moments in multiple planes during walking and stair ascent.

Medial opening wedge high tibial osteotomy is a surgical procedure intended to redistribute loads on the knee in patients with medial compartment knee osteoarthritis (OA). The surgery may affect moments in multiple planes during ambulation, with potential beneficial or detrimental effects on joint loads. The objective of this study was to investigate three-dimensional external knee moments before and after medial opening wedge high tibial osteotomy during level walking and during stair ascent. Fourteen patients with varus alignment and osteoarthritis primarily affecting the medial compartment of the tibiofemoral joint were assessed. Three-dimensional motion analyses during level walking and stair ascent was evaluated using inverse dynamics before, 6 and 12 months after surgery. Mean changes at 12 months suggested decreases in the peak knee adduction, flexion and internal rotation moments, with standardized response means ranging from 0.15 to 2.54. These decreases were observed despite increases in speed. Changes in alignment were associated with changes in the adduction and internal rotation moments, but not the flexion moment. Both pre- and postoperatively, the peak knee adduction moment was significantly lower (p=0.001) during stair ascent than during level walking, while the flexion and internal rotation moments were significantly higher (p<0.01). There were no changes in the knee moments on the non-surgical limb. Medial opening wedge high tibial osteotomy is associated with sustained (12 months) changes in knee moments in all three planes of motion during ambulation, suggesting substantial alterations of the loads on the knee during ambulation.

Adverse event rates and classifications in medial opening wedge high tibial osteotomy.

BACKGROUND: Previously reported complications in medial opening wedge (MOW) high tibial osteotomy (HTO) vary considerably in both rate and severity. PURPOSE: (1) To determine the rates of adverse events in MOW HTO classified into different grades of severity based on the treatments required and (2) to compare patient-reported outcomes between the different adverse event classifications. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: All patients receiving MOW HTO at a single medical center from 2005 to 2009 were included. Internal fixation was used in all cases, with either a nonlocking (Puddu) or locking (Tomofix) plate. Patients were evaluated at 2, 6, and 12 weeks; 6 and 12 months; and annually thereafter. Types of potential surgical and postoperative adverse events, categorized into 3 classes of severity based on the subsequent treatments, were defined a priori. Medical records and radiographs were then reviewed by an independent observer. The Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores were compared in subgroups of patients based on the categories of adverse events observed. RESULTS: A total of 323 consecutive procedures (242 males) were evaluated (age, mean ± standard deviation, 46 ± 9 years; body mass index, mean ± standard deviation, 30 ± 5 kg/m(2)). Adverse events requiring no additional treatment (class 1) were undisplaced lateral cortical breaches (20%), displaced (>2 mm) lateral hinge fracture (6%), delayed wound healing (6%), undisplaced lateral tibial plateau fracture (3%), hematoma (3%), and increased tibial slope ≥10° (1%). Adverse events requiring additional or extended nonoperative management (class 2) were delayed union (12%), cellulitis (10%), limited hardware failure (1 broken screw; 4%), postoperative stiffness (1%), deep vein thrombosis (1%), and complex regional pain syndrome (CRPS) type 1 (1%). Adverse events requiring additional or revision surgery and/or long-term medical care (class 3) were aseptic nonunion (3%), deep infection (2%), CRPS type 2 (1%), and severe hardware failure with loss of correction (1%). Additional surgery rate was 3%. Class 1 and 2 adverse events did not affect patient-reported outcomes at 6, 12, or 24 months postoperatively. Patients with class 3 adverse events had significantly lower total WOMAC scores at 6 months but not at 12 or 24 months postoperatively. CONCLUSION: The most common adverse event in MOW HTO requiring extended nonoperative treatment (class 2) is delayed union (12%). The rate of severe adverse events requiring additional surgery and/or long-term medical care (class 3) is low (7%).

A preference-based single-item measure of quality of life following medial opening wedge high tibial osteotomy: large improvements similar to arthroplasty.

BACKGROUND: Improvements in generic and disease specific scores have been reported with medial opening wedge high tibial osteotomy (MOW HTO). However, meaningful comparisons between competing surgical interventions have been hampered by the lack of a preference based single index of health related quality of life (HRQoL). The primary aim of this study was to derive and report a single index measure of HRQoL for patients undergoing MOW HTO, preoperatively and at 12 and 24 postoperatively. Secondary aims were to evaluate changes in various additional measures of quality of life at these time points. METHODS: The impact of MOW HTO was evaluated using generic and disease specific instruments. One hundred thirty eight patients completed the Medical Outcomes Study short form health survey (SF-12) and Knee Osteoarthritis Outcomes Score (KOOS) before, 12 and 24 months after surgery. A preference-based single index measure of HRQoL was calculated and changes were evaluated. RESULTS: The mean change in the HRQoL suggested large, clinically significant improvements from 0.69 preoperatively to 0.82 (p<0.001) and 0.8 at 12 and 24 months postoperatively respectively. All dimensions of the SF-12, except role mental health, and all dimensions of the KOOS also demonstrated statistically significant improvements between pre and postoperative measurements. CONCLUSIONS: The preoperative HRQoL of young patients with mechanical varus alignment and medial compartment knee osteoarthritis is similar to older patients with knee osteoarthritis. Medial opening wedge high tibial osteomoty results in significant improvements in HRQoL, the magnitude of which is comparable to other surgical interventions for knee osteoarthristis.

Staged medial opening wedge high tibial osteotomy for bilateral varus gonarthrosis: biomechanical and clinical outcomes.

PURPOSE: (1) To evaluate the effect of staged bilateral medial opening wedge high tibial osteotomy (HTO) on established biomechanical risk factors for disease progression and on validated measures of pain and function and (2) To compare outcomes in patients having the second surgery staged within or beyond 12 months of the first surgery. METHODS: Thirty-seven patients with bilateral varus alignment and medial compartment osteoarthritis underwent staged bilateral medial opening wedge HTO (21 within and 16 beyond 12 months). Patients underwent full-limb standing anteroposterior radiographs to determine frontal plane alignment (mechanical axis angle) and three-dimensional gait analysis to estimate the distribution of load across the tibiofemoral compartments (external knee adduction moment). Patients also completed the Knee Injury and Osteoarthritis Outcomes Scores (KOOS), the Lower Extremity Functional Scale, the Short Form Health Survey and the six-minute walk test (6MWT). Patients (both limbs) were evaluated before and approximately 6, 12 and 24 months after each surgery. RESULTS: There were statistically and clinically significant changes in both limbs that were of similar magnitudes and that remained relatively stable over time postoperatively. Mean (95% CI) improvements in outcomes were as follows. Mechanical axis angle: 9.4° (8.4°, 10.4°) (i.e. average change of both limbs), peak knee adduction moment: -1.7%BW*Ht (-2.1, -1.4 %BW*Ht) (i.e. average change of both limbs), 6MWT: 36.7 m (19.4, 54.0 m), SF-12 Physical Component Summary: 12.0 (8.5, 15.5) and KOOS Pain: 25.4 (19.6, 31.2). Other than the shorter time period to reach maximum benefit of both surgeries, there were no remarkable differences at final assessment between patients having surgeries staged within or beyond 12 months. CONCLUSIONS: The present findings demonstrate that patients with bilateral varus gonarthrosis experience marked improvements in established biomechanical risk factors for disease progression bilaterally (mechanical axis angles and external knee adduction moments), as well as clinically important improvements in patient-important outcomes, after staged medial opening wedge HTO. Current findings suggest no difference in outcomes for patients who have the second surgery staged within or beyond 12 months of the first surgery. LEVEL OF EVIDENCE: IV.

Changes in valgus and varus alignment neutralize aberrant frontal plane knee moments in patients with unicompartmental knee osteoarthritis.

To elucidate the effects of frontal plane lower limb alignment on gait biomechanics, we compared knee joint moments and frontal plane angular impulse before and after varus or valgus producing osteotomy in patients with lateral or medial compartment osteoarthritis, and in healthy participants with neutral alignment. Thirty-nine subjects participated (13 valgus gonarthrosis, 13 varus gonarthrosis, 13 controls). Patients underwent 3D gait analysis and radiographic assessment of alignment (mechanical axis angle; MAA) before and 6 months after surgery, and were compared to controls. Mean changes (95%CI) in frontal plane angular impulse indicated a 0.82%BW·Ht·s (0.49,1.14) increase in adduction impulse in patients after varus osteotomy, and a 0.61%BW·Ht·s (0.37,0.86) decrease in adduction impulse in patients after valgus osteotomy, equating to a 53% and 45% change from preoperative values, respectively. Preoperative frontal plane angular impulse was significantly different between both patient groups and controls before surgery, but not after. The cross-sectional data suggest that frontal plane angular impulse is very highly correlated to MAA before surgery (R=0.87), but not after (R=0.39), and that an adduction impulse predominates until 7° of valgus, at which point an abduction impulse predominates. The prospective surgical realignment data indicate that for every 1° change in MAA toward varus, there is a 0.1%BW·Ht·s (or 1.6 N m s) change in frontal plane knee angular impulse toward adduction, and vice versa. These overall findings illustrate the potent effects that lower limb alignment can have on frontal plane gait biomechanics.

A case series of lateral opening wedge high tibial osteotomy for valgus malalignment.

INTRODUCTION: Lateral opening wedge high tibial osteotomy is a rarely employed surgical technique used for the treatment of lateral knee pain and degeneration in the setting of genu valgum. There exists little evidence of the suitability of this procedure for patients requiring osteotomies with a small correction. MATERIALS AND METHODS: A case series of 23 patients (24 knees) undergoing lateral opening wedge high tibial osteotomy with a minimum follow-up of 2 years was performed between 2002 and 2008. A surgical technique avoiding the need for fibular osteotomy is described. Adverse events, patient-reported outcomes and radiographic measures of alignment were assessed at baseline, at 6 months postoperatively, and at time of final follow-up. A subgroup of 12 patients also underwent 3D gait analysis at the same time points. RESULTS: The mean follow-up was 52 months (±20.4). Statistically and clinically significant improvements were identified in the lower extremity functional scale [mean change (95%CI) = 10 (2.4, 17.6)], and in the knee injury and osteoarthritis outcome score [mean change (95%CI) = 10.9 (0.5, 21.4)]. Mechanical axis changed from 2.4 ± 2.4° valgus to 0 ± 2.6° varus (p<0.001), anatomical axis from 6.9 ± 2.8° to 4.7 ± 2.5° valgus (p < 0.001), with weight-bearing line offset changing from 60.2 ± 11.4% to 49.5 ± 12.4% (p < 0.001). Change in lateral tibial slope, from 6.5 ± 2.2° to 7.5 ± 2.3°, was very small and not statistically significant (n.s.). The peak knee adduction moment during gait significantly increased [mean change (95%CI) = 0.72%BW*Ht (0.42, 1.02), suggesting a medial shift in dynamic knee joint load. Two patients underwent total knee arthroplasty during the study period. CONCLUSIONS: Lateral opening wedge high tibial osteotomy is a viable surgical option for patients with lateral knee pain and valgus malalignment requiring small degrees of correction. LEVEL OF EVIDENCE: IV.

Preoperative strength training for patients undergoing high tibial osteotomy: a prospective cohort study with historical controls.

STUDY DESIGN: Prospective cohort with historical controls. OBJECTIVE: To examine the effects of a 12-week preoperative high-intensity resistance training program on postoperative outcomes. BACKGROUND: The primary goals of high tibial osteotomy (HTO) are to decrease pain and improve overall function during activities of daily living and participation in sport and recreation in relatively young, active individuals with knee osteoarthritis. However, the postoperative recovery typically requires a considerable period of protected weight-bearing that can result in substantial deficits in muscular strength. METHODS: Fourteen patients (mean ± SD, 48.0 ± 7.8 years; 13 males, 1 females), scheduled for medial opening wedge HTO, completed a 12-week preoperative high-intensity isokinetic resistance training program focusing on quadriceps and hamstrings strength. These patients were matched to baseline clinical and demographic characteristics of 14 patients who previously received a medial opening wedge HTO without preoperative training. All outcomes were measured before and 6 months after surgery. The sport and recreation subscale of the Knee Injury and Osteoarthritis Outcome Score (KOOS) was the primary outcome of interest. Secondary outcomes included the other KOOS subscales, scores on the Lower Extremity Functional Scale, and selected kinematic and kinetic variables obtained from 3-dimensional gait analysis. RESULTS: The patients in the preoperative training group achieved significantly greater scores on the KOOS sport and recreation (mean ± SD, 58.6 ± 16.6 versus 42.1 ± 20.4; mean difference, 16.4; 95% CI: 2.0, 30.9) and activities of daily living (mean ± SD, 85.3 ± 9.3 versus 76.9 ± 12.0; mean difference, 8.4; 95% CI: 0.1, 16.8) subscales. There were no significant differences between groups on other outcomes. CONCLUSION: The present findings suggest preoperative high-intensity resistance training of the quadriceps and hamstrings before HTO improves postoperative functioning in sport, recreation, and activities of daily living. LEVEL OF EVIDENCE: Therapy, level 2b.