Survivorship of high tibial osteotomy in the treatment of osteoarthritis of the knee: a retrospective cohort study with fourteen years' follow-up.

PURPOSE: This study was to evaluate the survivorship of HTO for the treatment of medial compartment osteoarthritis (OA) in young and active patients from two teaching hospitals in a single city. METHODS: This is a retrospective cohort multicenter study looking at HTO for treatment of medial compartment OA. We analyzed a case series of HTO's performed by four surgeons in two centres over a 14-year period. Failure was defined as conversion to total knee replacement (TKR). All cases where additional procedures for instability of the knee were performed at the time of the index surgery were excluded. Time to failure was recorded, and a Kaplan-Meir (KM) analysis was performed to evaluate survivorship. Univariate binary regression analysis was undertaken to identify associations between risk factors and failure. RESULTS: A total of 96 patients were included in the study with a median age was 45 years. The survivorship at five years post-op was 90.3%, and at ten years post-op, it was 82%. Patients that were 14 years after surgery had a survivorship of 65%. Also, 18.8% of patients required the removal of their metalwork. The overall complication rate was 6.3%. The univariate regression analysis showed that higher age (p = 0.02) and larger corrections requiring the use of bone graft increased the risk of failure (p = 0.02). There was no statistically significant correlation between laterality, gender, complication rate, and pre-operative alignment to survivorship. CONCLUSION: This is one of the largest reported case series of HTO's with comparable survivorship at five and ten year follow-up compared to the reported literature. There was an association found between increasing age and larger corrections requiring bone graft at index procedure to increasing failure rate.

Increased patellar bone tracer uptake in preoperative SPECT/CT before medial opening high tibial osteotomy correlates with inferior clinical outcome.

PURPOSE: The purpose of this study was to investigate whether specific bone tracer uptake (BTU) patterns on preoperative SPECT/CT could predict which patients with varus alignment and medial overload would particularly benefit from medial opening-wedge high tibial osteotomy (MOWHTO). It was the hypothesis that an increased preoperative BTU relative to the reference BTU of the femur on SPECT/CT in the lateral and patellar compartments of the knee are predictive factors for inferior clinical outcome and that the clinical outcome correlates with the extent of alignment correction. METHODS: Twenty-three knees from 22 patients who underwent MOWHTO for medial compartment overload were investigated preoperatively using Tc-99m-SPECT/CT. BTU was quantified and localised to specific joint areas according to a previously validated scheme. Pre- and postoperative mechanical alignment was measured. Clinical outcome was assessed at a median of 24 months (range 11-30) after MOWHTO by collecting the WOMAC score. RESULTS: Significant correlations between BTU in the patellar area and the total WOMAC score and its subcategories pain and stiffness were found. Thus, BTU in the 1sPat area (superior lateral patellar compartment) correlated with total WOMAC (rho = 0.43, p = 0.04), pain subcategory (rho = 0.43, p = 0.04), and stiffness subcategory (rho = 0.59, p = 0.003). No significant correlations were found between alignment correction, age, gender and WOMAC. CONCLUSION: This study highlights the role of preoperative SPECT in modern knee surgery to obtain information about the loading pattern on different compartments of the knee. Despite the limited number of participants, the present study shows that a preoperative SPECT/CT scan can help the treating surgeons to identify patients who may be at risk of inferior clinical outcome if an MOWHTO is considered, as an elevated BTU in the patellar region on preoperative SPECT/CT appears to be a potential risk factor for postoperative pain and stiffness. LEVEL OF EVIDENCE: Level III.

Uniplane medial opening wedge high tibial osteotomy relative to a biplane osteotomy can reduce the incidence of lateral-hinge fracture.

PURPOSE: With surgical modifications reflecting plate design differences of the specific rigid locking plate adding a metal wedge, uniplane high tibial osteotomy (HTO) has fewer lateral-hinge fractures and fewer plate irritations than biplane HTO. METHODS: Uniplane HTO with a rigid locking plate adding a metal wedge was compared with biplane HTO with a rigid locking plate including a proximal D-hole. For comparison, the HTO patients' medical records and radiological results in a single institution were retrospectively reviewed. The Oxford knee score 2 years post-operation, CT scan at post-operative day 2 and serial standing long-bone scanography were reviewed to evaluate clinical outcome and radiological results, including the incidence of lateral-hinge fracture, plate irritation and correction loss to varus alignment. RESULTS: A total of 103 knees, including 59 uniplane HTO and 44 biplane HTO, were enrolled. The Oxford scores were 38.1 ± 7.8 in the uniplane group and 35.9 ± 8.3 in the biplane group (ns). On CT scans, more lateral-hinge fractures developed in the biplane group, and seven knees (12%) of the uniplane group and 12 knees (27%) of the biplane group had Takeuchi type I stable hinge fracture (p < 0.05); unstable fracture was not noted in either group. Plate irritation occurred in nine knees (19%) of the uniplane group and in 14 knees (32%) of the biplane group, and the difference was statistically significant (p < 0.05). CONCLUSION: In clinical situations including the use of surgical modifications reflecting plate design differences, fewer lateral-hinge fractures developed after uniplane medial opening-wedge HTO compared with biplane HTO. Uniplane HTO potentially represents a better option than biplane HTO for the prevention of lateral-hinge fracture. LEVEL OF EVIDENCE: IV.

Unicompartmental Knee Arthroplasty Provides Significantly Greater Improvement in Function than Total Knee Arthroplasty Despite Equivalent Satisfaction for Isolated Medial Compartment Osteoarthritis.

BACKGROUND: While some advocate for unicompartmental knee arthroplasty (UKA) for isolated medial compartment osteoarthritis (OA), others favor total knee arthroplasty (TKA). The purpose of this study was to compare the functional outcomes of UKA and TKA performed for patients with unicompartmental arthritis (OA). METHODS: A study was performed on 133 patients that met strict criteria for UKA, but who underwent either medial UKA or TKA for isolated medial compartment OA based upon physician equipoise. The primary outcome-New Knee Society Score (KSS)-was assessed preoperatively and at 2 years postoperatively. A propensity score weighted regression was used to balance the groups on several key covariates, including age, gender, body mass index, and baseline KSS. RESULTS: After propensity weighting, there were no significant differences between UKA and TKA in overall baseline KSS or KSS after 2 years postoperatively. While TKA patients had demonstrated a significantly greater improvement in the symptoms KSS subscale, UKA patients had a significantly greater improvement in the function subscale. Expectations were significantly more likely to be met after UKA, but there were no differences in patient satisfaction. CONCLUSION: UKA and TKA are both highly successful options for treating patients with medial compartment OA, although functionality increased more, and expectations were more likely to be met, after UKA in this study. Given equivalent patient satisfaction after both TKA and UKA, surgeons should consider factors such as clinical experience, individual preference, cost of care, surgical risk, and recovery needs, when making treatment decisions regarding this clinical entity.

Medial compartment knee osteoarthritis: age-stratified cost-effectiveness of total knee arthroplasty, unicompartmental knee arthroplasty, and high tibial osteotomy.

PURPOSE: To compare the age-based cost-effectiveness of total knee arthroplasty (TKA), unicompartmental knee arthroplasty (UKA), and high tibial osteotomy (HTO) for the treatment of medial compartment knee osteoarthritis (MCOA). METHODS: A Markov model was used to simulate theoretical cohorts of patients 40, 50, 60, and 70 years of age undergoing primary TKA, UKA, or HTO. Costs and outcomes associated with initial and subsequent interventions were estimated by following these virtual cohorts over a 10-year period. Revision and mortality rates, costs, and functional outcome data were estimated from a systematic review of the literature. Probabilistic analysis was conducted to accommodate these parameters' inherent uncertainty, and both discrete and probabilistic sensitivity analyses were utilized to assess the robustness of the model's outputs to changes in key variables. RESULTS: HTO was most likely to be cost-effective in cohorts under 60, and UKA most likely in those 60 and over. Probabilistic results did not indicate one intervention to be significantly more cost-effective than another. The model was exquisitely sensitive to changes in utility (functional outcome), somewhat sensitive to changes in cost, and least sensitive to changes in 10-year revision risk. CONCLUSIONS: HTO may be the most cost-effective option when treating MCOA in younger patients, while UKA may be preferred in older patients. Functional utility is the primary driver of the cost-effectiveness of these interventions. For the clinician, this study supports HTO as a competitive treatment option in young patient populations. It also validates each one of the three interventions considered as potentially optimal, depending heavily on patient preferences and functional utility derived over time.

Medial unicondylar knee arthroplasty combined to anterior cruciate ligament reconstruction.

PURPOSE: The purpose of the present study was to retrospectively evaluate the outcomes of patients who underwent combined medial unicompartmental knee arthroplasty (UKA) and anterior cruciate ligament (ACL) reconstruction. The hypothesis was that this procedure would lead to a high success rate in patients affected by isolated medial unicompartmental osteoarthritis and concomitant ACL deficiency. METHODS: Fourteen patients with primary ACL lesion and concomitant medial compartment symptomatic osteoarthritis treated from 2006 to 2010 were followed up for an average time of 26.7 months (SD 4.2). Assessment included KOOS score, Oxford Knee score, American Knee Society scores, WOMAC index of osteoarthritis, Tegner activity level and objective examination including instrumented laxity test with KT-1000 arthrometer. Radiological assessment was done with standard simple radiographs in order to get information about any presence of loosening of the components. RESULTS: KOOS score, OKS, WOMAC index and the AKSS improved significantly after surgery (p < 0.001). Regarding AKSS, improvement was noted both in the objective score and in the functional one (p < 0.001). There was no clinical evidence of instability in any of the knees as evaluated with clinical laxity testing. No pathologic radiolucent lines were observed around the components. In one patient signs of osteoarthritis in the lateral compartment were observed 28 months after surgery. CONCLUSIONS: UKA combined with ACL reconstruction is a valid therapeutic option for the treatment of combined medial unicompartmental knee osteoarthritis and ACL deficiency in young and active patients and confirms subjective and objective clinical improvement 2 years after surgery. The use of a fixed-bearing prosthesis represents a reliable feature as it allows to overcome problems of improper ligament tensioning during the implantation of the components. LEVEL OF EVIDENCE: IV.

Surgical accuracy in high tibial osteotomy: coronal equivalence of computer navigation and gap measurement.

PURPOSE: Medial opening wedge high tibial osteotomy (MOW HTO) is now a successful operation with a range of indications, requiring an individualised approach to the choice of intended correction. This manuscript introduces the concept of surgical accuracy as the absolute deviation of the achieved correction from the intended correction, where small values represent greater accuracy. Surgical accuracy is compared in a randomised controlled trial (RCT) between gap measurement and computer navigation groups. METHODS: This was a prospective RCT conducted over 3 years of 120 consecutive patients with varus malalignment and medial compartment osteoarthritis, who underwent MOW HTO. All procedures were planned with digital software. Patients were randomly assigned into gap measurement or computer navigation groups. Coronal plane alignment was judged using the mechanical tibiofemoral angle (mTFA), before and after surgery. Absolute (positive) values were calculated for surgical accuracy in each individual case. RESULTS: There was no significant difference in the mean intended correction between groups. The achieved mTFA revealed a small under-correction in both groups. This was attributed to a failure to account for saw blade thickness (gap measurement) and over-compensation for weight bearing (computer navigation). Surgical accuracy was 1.7° ± 1.2° (gap measurement) compared to 2.1° ± 1.4° (computer navigation) without statistical significance. The difference in tibial slope increases of 2.7° ± 3.9° (gap measurement) and 2.1° ± 3.9° (computer navigation) had statistical significance (P < 0.001) but magnitude (0.6°) without clinical relevance. CONCLUSION: Surgical accuracy as described here is a new way to judge achieved alignment following knee osteotomy for individual cases. This work is clinically relevant because coronal surgical accuracy was not superior in either group. Therefore, the increased expense and surgical time associated with navigated MOW HTO is not supported, because meticulously conducted gap measurement yields equivalent surgical accuracy. LEVEL OF EVIDENCE: I.

Clinical outcome after UKA and HTO in ACL deficiency: a systematic review.

PURPOSE: In the treatment of medial osteoarthritis secondary to anterior cruciate ligament (ACL) injury there is no consensus about optimum treatment, with both high tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA) being viable options. The aim of this review was to compare the outcomes of these treatments, both with or without ACL reconstruction. METHODS: EMBASE, MEDLINE and the Clinical Trials Registers were searched to identify relevant studies. Studies meeting pre-defined inclusion criteria were assessed independently by two researchers for methodological quality and data extracted. RESULTS: Twenty-six studies involving 771 patients were identified for inclusion. No randomized controlled trials were identified. Seventeen studies reported outcomes following HTO and nine studies reported outcomes following UKA. HTO patients were significantly younger than those receiving UKA, and ACL reconstruction patients were younger than non-reconstructed patients. Treatment with HTO ACL reconstruction had the lowest revision rate (0.62/100 observed component years) but the highest rate of complications (4.61/100 observed component years). Too little data were available to test for differences in outcome between different surgical techniques or prosthesis designs. CONCLUSIONS: Limited conclusions about the optimum treatment can be made due to the absence of controlled trials. In patients treated with HTO ACL reconstruction, the high complication rate likely outweighs its minimally superior survival. Outcomes following UKA ACL reconstruction are similar to outcomes for UKA in the ACL intact knee without any increase in complications. As such in patients meeting indications for UKA, UKA ACL reconstruction should be performed with further work required to identify the optimum treatment in other patient groups. LEVEL OF EVIDENCE: IV.

Medial unicompartmental knee arthroplasty in the ACL-deficient knee.

Symptomatic osteoarthritis (OA) of the knee develops often in association with anterior cruciate ligament (ACL) deficiency. Two distinct pathologies should be recognised while considering treatment options in patients with end-stage medial compartment OA and ACL deficiency. Patients with primary ACL deficiency (usually traumatic ACL rupture) can develop secondary OA (typically presenting with symptoms of instability and pain) and these patients are typically young and active. Patients with primary end stage medial compartment OA can develop secondary ACL deficiency (usually degenerate ACL rupture) and these patients tend to be older. Treatment options in either of these patient groups include arthroscopic debridement, reconstruction of the ACL, high tibial osteotomy (HTO) with or without ACL reconstruction, unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA). General opinion is that a functionally intact ACL is a fundamental prerequisite to perform a UKA. This is because previous reports showed higher failure rates when ACL was deficient, probably secondary to wear and tibial loosening. Nevertheless in some cases of ACL deficiency with end-stage medial compartment OA, UKA has been performed in isolation and recent papers confirm good short- to mid-term outcome without increased risk of implant failure. Shorter hospital stay, fewer blood transfusions, faster recovery and significantly lower risk of developing major complications like death, myocardial infarction, stroke, deep vein thrombosis (as compared to TKA) make the UKA an attractive option, especially in the older patients. On the other hand, younger patients with higher functional demands are likely to benefit from a simultaneous or staged ACL reconstruction in addition to UKA to regain knee stability. These procedures tend to be technically demanding. The main aim of this review was to provide a synopsis of the existing literature and outline an evidence-based treatment algorithm.

Calipered Kinematically Aligned Medial Unicompartmental Knee Arthroplasty: A Surgical Technique.

This study presents a surgical technique for kinematically aligned medial unicompartmental knee arthroplasty with the MOTO (Medacta Corporate, Switzerland) partial knee implant. This technique aims to replicate the native medial femoral and tibial morphology by providing caliper-verified bone resections and kinematic alignment principles. The paper provides a comprehensive overview of the surgical steps and discusses the implications for implant longevity.

Synovial Folds Impingement After Unicondylar Knee Arthroplasty.

Soft tissue impingement after total knee arthroplasty has been reported; however, complications after unicondylar knee arthroplasty (UKA) have rarely been reported. We report a rare case of synovial fold impingement that occurred after UKA and caused severe pain with clicking during knee flexion and extension. Diagnostic arthroscopy was performed 3 weeks after UKA and found that a hypertrophied and congested synovial fold in the medial compartment impinged on the femoral component during knee flexion and extension. After excising the synovial fold, the patient's symptoms improved. Synovial fold impingement is a complication that should be considered when patients complain of severe pain with clicking in the knee after UKA.

Are relative contraindications for unicompartmental knee replacements in medial compartment osteoarthritis really contraindications?

Background: Medial unicompartment knee replacement (UKR) is performed for isolated medial compartment osteoarthritis. Understanding the factors influencing functional outcomes helps patient selection and outcomes. We will review the association between pre-operative BMI and patellofemoral articular wear on post operative Oxford Knee Scores at >2 and > 5 years. Methods: A retrospective review of a prospectively collected database was performed. Inclusion criteria were medial UKR for medial compartment OA. The exclusion criteria were age <16, revision procedures and lateral UKR's. Data was collected between 26/6/2014 and 25/8/2022. Statistical analysis was performed using SPSS. Significance was given to variables that reached p < 0.05. Results: 159 UKR procedures were identified in 155 patients. 116 procedures carried out on 111 patients had follow up at > 2 years. At 5 years there were 14 patients had OKS recorded. There was no statistical difference in the ICRS grade I&II vs III&IV groups for >2 year or >5 year OKS with p = 0.408 and p = 0.876. For BMI there was a moderately negative correlation on spearman's rank p(df) = -0.339 (CI 95 % -0.538, -0.104) at >2 years, which was statistically significant with p = 0.004. >5 year data didn't reach significance with p = 0.828. Conclusion: BMI maybe an important patient factor in predicting post operative OKS at 2-5 years. This is beneficial to surgeons for patient selection in medial UKR. Patellofemoral wear doesn't appear to impact on post operative functional outcomes. This supports the theory that patient who suffer from patellofemoral wear, as well as medial compartment wear can benefit from UKR, expanding the current indications.

Patient-specific instrumentation for medial opening wedge high tibial osteotomies in the management of medial compartment osteoarthritis yields high accuracy and low complication rates: A systematic review.

IMPORTANCE: There has been growing interest in the use of patient-specific instrumentation (PSI) to maximise accuracy and minimise the risk of major complications for medial opening-wedge high tibial osteotomies (MOW-HTOs). Numerous studies have reported the efficacy and safety of implementing this technology into clinical practice, yet no systematic review summarising the clinical literature on PSI for MOW-HTOs has been performed to date. AIM: The aim of this investigation was to perform a systematic review summarising the evidence surrounding the use of PSI for MOW-HTOs in the management of medial compartment osteoarthritis. EVIDENCE REVIEW: PubMed, Scopus, and the Cochrane Library were queried in October 2021 for studies that used PSI for MOW-HTOs when managing medial compartment knee osteoarthritis. Primary outcomes included accuracy in coronal plane correction (mechanical medial proximal tibial angle), sagittal plane correction (posterior tibial slope), and mechanical axis correction (hip-knee-ankle angle [HKA], mechanical femorotibial angle, and weight-bearing line). Accuracy was defined as error between post-operative measurements relative to the planned pre-operative correction. A secondary outcome was the incidence of major complications. FINDINGS: This review included eight different techniques among the 14 included studies. There was a weighted mean error of 0.5° (range: 0.1°-1.3°) for the mechanical medial proximal tibial angle, 0.6° (range: 0.3°-2.7°) for the posterior tibial slope, and 0.8° (range: 0.1°-1.0°) for the hip-knee-ankle angle. Four studies compared the correctional error of the mechanical axis between conventional techniques and PSI techniques. The comparative difference between the two techniques favoured the use of PSI for MOW-HTOs (standardised mean difference â€‹= â€‹0.52; 95% confidence interval, 0.16 to 0.87; p â€‹= â€‹0.004). Among the 14 studies evaluated, four studies explicitly reported no major complications, while five studies reported a non-zero incidence of major complications. Among these nine studies, the weighted mean major complication rate was 7.1% (range: 0.0-13.0%). CONCLUSIONS AND RELEVANCE: The findings of this present systematic review suggest that the use of PSI for MOW-HTOs leads to high accuracy relative to the planned corrections in the coronal plane, sagittal plane, and mechanical axis. Furthermore, these findings would suggest there is a low risk of major complications when implementing PSI for MOW-HTOs. LEVEL OF EVIDENCE: Systematic review; IV.

Prognostic factors for medial open-wedge high tibial osteotomy with spacer implantation in patients with medial compartmental knee osteoarthritis.

BACKGROUND: To identify medial open-wedge high tibial osteotomy (MOWHTO) prognostic factors with wedge-shaped spacer implantation (spacer-type MOWHTO) for varus medial compartment knee osteoarthritis. METHODS: Patients who underwent spacer-type MOWHTO between August 2018 and September 2019 were prospectively enrolled in this study. Patients were divided into effective group and invalid group based on the Western Ontario and McMasters University Osteoarthritis Index (WOMAC) score one year postoperatively. The variables assessed at baseline and one year postoperatively including age, sex, body mass index (BMI), Kellgren-Lawrence (K-L) grade, hip-knee-ankle angle (HKAA), medial proximal tibial angle (MPTA), posterior tibial slope angle (PTSA), Blackburn-Peel index (BPI), duration of symptoms, and WOMAC score were compared. Prognostic factors were analyzed using logistic regression, and the corresponding odds ratios were also calculated. RESULTS: A total of 104 patients were enrolled in the study protocol at one year postoperatively. The WOMAC score decreased from 72.39 ± 12.95 at baseline to 20.06 ± 12.96 at one year postoperatively. Univariate analysis revealed that the significant predictors of the WOMAC score were age > 70 years, BMI > 30 kg/m2, K-L grade IV, and pre-HKAA > 10° (P < 0.1 for all). Multivariable logistic regression analysis revealed that age > 70 (OR = 4.861) and K-L grade IV (OR = 6.590) were significantly associated with the higher WOMAC score at one year postoperatively. CONCLUSIONS: Spacer-type MOWHTO is an effective treatment for osteoarthritis with varus deformity. The prognostic factors for spacer-type MOWHTO are age and K-L grade.

[Arthroscopy combined with high tibial osteotomy for the treatment of knee medial compartment osteoarthritis and its influence on cartilage injury].

OBJECTIVE: To investigate the effectiveness of arthroscopy combined with high tibial osteotomy (HTO) in the treatment of knee medial compartment osteoarthritis and its influence on cartilage injury. METHODS: The clinical data of 57 patients with knee medial compartment osteoarthritis treated with arthroscopy combined with HTO between March 2017 and March 2019 were retrospectively analyzed. There were 27 males and 30 females with an average age of 52.4 years (range, 44-57 years). The disease duration ranged from 3 to 6 years, with an average of 3.6 years. Twenty-one cases were grade Ⅰ and 36 cases were grade Ⅱ according to Kellgren-Lawrence classification. Flexion contracture of knee joint ranged from 0° to 8° with an average of 1.36° and varus deformity ranged from 5° to 10° with an average of 7.60°. Preoperative arthroscopic evaluation showed that there were 11 cases with grade Ⅰ, 42 cases with gradeⅡ, and 4 cases with grade Ⅲ according to the international cartilage repair classification system (ICRS). Lysholm score, American Hospital for Special Surgery (HSS) score, and International Knee Documentation Committee (IKDC) score were used to evaluate knee function before operation, at 3 months, at 1 year after operation, and at last follow-up. Visual analogue scale (VAS) score was used to evaluate pain. The mechanical medial proximal tibial angle (mMPTA) and femoral tibial angle (FTA) were measured before operation and at last follow-up. When the internal fixator was removed, the knee arthroscopy was performed again to explore the cartilage repair condition, and the regeneration level and maturity level were selected for cartilage grading evaluation. RESULTS: All patients' incisions healed by first intention after operation, and no incision infection or skin necrosis occurred. After operation, the knee joint function of the patients was significantly improved, the pain symptoms were relieved, and the force line measurement reached the target set before operation. The VAS score, Lysholm score, HSS score, and IKDC score were significantly improved at 3 months, 1 year after operation, and at last follow-up when compared with those before operation. They were gradually improved with the time and there were significant differences between time points ( P<0.05). mMPTA and FTA were significantly improved at last follow-up when compared with those before operation ( P<0.05). When the internal fixator was removed, the arthroscopic re-assessment found that the cartilage regeneration was classified into 10 cases of grade Ⅰ and 47 cases of grade Ⅱ; 18 cases of immature cartilage regeneration and 29 cases of mature cartilage regeneration were found in the knee joints of grade Ⅱ cartilage regeneration. There was no significant difference in the cartilage regeneration grade between different ICRS gradings ( H=0.176, P=0.916), and the difference in maturity grading was significant ( H=10.500, P=0.005). CONCLUSION: Arthroscopy combined with HTO for the treatment of knee medial compartment osteoarthritis can effectively improve the symptoms and function of the knee joint, and can promote the regeneration of articular cartilage.

Incidence and Factors Affecting the Occurrence of Lateral Hinge Fracture After Medial Opening-Wedge High Tibial Osteotomy.

BACKGROUND: Few clinical studies have reported the predictors of lateral hinge fracture (LHF) after medial opening-wedge high tibial osteotomy (MOWHTO). PURPOSE/HYPOTHESIS: The purpose was to compare the incidence of LHF on plain radiographs versus computed tomography (CT) scans and to investigate the factors related to the development of LHF after MOWHTO. We hypothesized that (1) a higher LHF detection rate would be seen on CT scans versus plain radiographs and (2) LHF incidence would be related to opening gap width and hinge position. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 3. METHODS: A total of 97 MOWHTO cases were included. The presence and types of LHF were determined from plain radiographs and CT scans. Radiographic parameters were measured on plain radiographs taken 6 weeks postoperatively. Anterior and posterior opening gap widths, coronal and sagittal osteotomy slopes, and fibular height were calculated from CT scans. The wedge-hinge relationship and the zone of hinge position were assessed, and the patient and radiographic factors related to LHF occurrence were evaluated. RESULTS: Seventeen LHF cases (20.5%) were detected on plain radiographs, while significantly more (37 cases; 44.6%) were found on CT scans (P = .001). Based on Takeuchi classification, 28 LHF cases were considered type 1, 7 were type 2, and 2 were type 3. Logistic regression analysis revealed that opening gap width (odds ratio, 1.615; 95% confidence interval, 1.232-2.118; P = .001) and posterior opening gap width (odds ratio, 3.731; 95% confidence interval, 1.642-4.351; P = .008,) differed significantly between patients with versus without LHF. Other patient and radiographic factors were not significantly related to LHF occurrence. Receiver operating characteristic curve analysis identified the opening gap width cutoff values for LHF as 11.0 mm (area under the curve, 0.81; sensitivity, 78.4%; specificity, 73.9%). CONCLUSION: The incidence of LHF after MOWHTO can be underestimated on plain radiographs compared with CT scans. Only large opening gap width, especially posterior gap width, was found to have a statistically significant relationship with occurrence of LHF. Therefore, special caution for possible LHF may be needed if a large correction is planned.

Preoperative planning by osteotomy master software helps to improve the accuracy of target limb alignment in high tibial osteotomy.

BACKGROUND: The accuracy of targeted lower limb alignment correction following HTO is closely related to patients' pain relief and knee joint survival time. How to accurately perform osteotomy and how to obtain the ideal target limb alignment to maximize the curative effect are the difficulty in HTO practice. The purpose of this study is to evaluate the predictive and application value of osteotomy master software (OsteoMaster) in coronal plane preoperative planning of high tibial osteotomy. METHOD: Sixty-seven patients with medial compartment osteoarthritis and varus deformity treated by medial open-weight high tibial osteotomy were enrolled and divided into observation group (31 cases) and control group (36 cases). The observation group was planned by OsteoMaster, while the control group was planned by Miniaci. The preoperative predicted values of osteotomy depth, open height, correction angle, WBL ratio, and FTA of the observation group were compared with the actual intraoperative values to study their accuracy. The operative time, blood loss, number of fluoroscopy, and WBL ratio were compared between the observation group and the control group to study its application value. RESULT: There was no significant difference between two groups in preoperative prediction and intraoperative reality of osteotomy depth, open height, correction angle, FTA, and WBL ratio (P > 0.05). The operation time and number of fluoroscopy in the observation group were significantly less than those in the control group (P < 0.05), while the difference in blood loss was not statistically significant (P > 0.05). The good rate of WBL ratio was 87.1% in the observation group and 75% in the control group. CONCLUSION: OsteoMaster has predictive value in osteotomy depth, open height, correction angle, FTA, and WBL ratio of HTO, which is also helpful to reduce the number of fluoroscopy, shorten the operation time, and improve the accuracy of target limb alignment. The drawback of this approach is 2-dimensional approach in contrast to 3-dimensional preoperative planning that is including the more real study.

Functional Outcome of High Tibial Osteotomy in Patients with Medial Compartment Osteoarthritis Using Dynamic Axial Fixator -a prospective study.

INTRODUCTION: Medial Compartment Osteoarthritis of the knee is becoming a widespread problem. The surgical options include high tibial osteotomy, unicompartmental knee replacement, and total knee replacement. Replacement surgeries are not advised in the younger age group, so in these patients, high tibial osteotomy is the only option. In this study, we have assessed the functional and radiological outcomes of high tibial osteotomy done by hemicallostasis method. METHOD: We report the outcome of 30 patients (30 knees) who underwent hemicallostasis with a dynamic external fixator for medial compartment osteoarthritis of the knee. The radiological assessment was done with the help of Hip Knee Ankle angle. The functional scoring was done via Oxford knee score, IKDC, KOOS, and WOMAC score. RESULTS: At a mean follow up of 35 months, the preoperatively mean HKA angle was 172 ± 30. The mean HKA angle postoperatively was 184 ± 10. Appropriate correction of the HKA angle was achieved in 24 of 30 patients (80%). Whereas, there was under correction in 3 patients (10%) and overcorrection in 3 (10%) patients. All the functional scores showed significant improvement in the postoperative scores. There was a positive correlation between the HKA angle and oxford, IKDC, KOOS, and WOMAC Score. Complications like superficial pin tract infection were seen in 3 (10%) patients, deep infection in 1 (3%), and early union of osteotomy in 1 (3%) patient leading to revision of the osteotomy. . CONCLUSION: HTO is effective in improving pain, function, activity of daily living, and quality of life in patients suffering from medial compartment Osteoarthritis of the knee. Hip Knee Ankle Angle is an important parameter to restore for better functional outcomes. The Advantage of using a dynamic axial fixator is the precision in achieving calculated correction without any implant in the bone once the correction is achieved along with good healing rates.

Accuracy of 3D-planned patient specific instrumentation in high tibial open wedge valgisation osteotomy.

PURPOSE: High tibial osteotomy (HTO) is an effective treatment option in early osteoarthritis. However, preoperative planning and surgical execution can be challenging. Computer assisted three-dimensional (3D) planning and patient-specific instruments (PSI) might be helpful tools in achieving successful outcomes. Goal of this study was to assess the accuracy of HTO using PSI. METHODS: All medial open wedge PSI-HTO between 2014 and 2016 were reviewed. Using pre- and postoperative radiographs, hip-knee-ankle angle (HKA) and posterior tibial slope (PTS) were determined two-dimensionally (2D) to calculate 2D accuracy. Using postoperative CT-data, 3D surface models of the tibias were reconstructed and superimposed with the planning to calculate 3D accuracy. RESULTS: Twenty-three patients could be included. A mean correction of HKA of 9.7° ± 2.6° was planned. Postoperative assessment of HKA correction showed a mean correction of 8.9° ± 3.2°, resulting in a 2D accuracy for HKA correction of 0.8° ± 1.5°. The postoperative PTS changed by 1.7° ± 2.2°. 3D accuracy showed average 3D rotational differences of - 0.1° ± 2.3° in coronal plane, - 0.2° ± 2.3° in transversal plane, and 1.3° ± 2.1° in sagittal plane, whereby 3D translational differences were calculated as 0.1 mm ± 1.3 mm in coronal plane, - 0.1 ± 0.6 mm in transversal plane, and - 0.1 ± 0.6 mm in sagittal plane. CONCLUSION: The use of PSI in HTO results in accurate correction of mechanical leg axis. In contrast to the known problem of unintended PTS changes in conventional HTO, just slight changes of PTS could be observed using PSI. The use of PSI in HTO might be preferable to obtain desired correction of HKA and to maintain PTS.

Association between stages of medial compartment osteoarthritis and three-dimensional knee alignment in the supine position: A cross-sectional study.

BACKGROUND: Osteoarthritis (OA) of the knee causes changes in knee alignment. A detailed knowledge of knee alignment is needed for correct assessment of the extent of disease progression, determination of treatment strategy, and confirmation of treatment effectiveness. However, deterioration of knee alignment during progression of OA has not been adequately characterized. The aims of this study were to clarify the changes in three-dimensional static knee alignment as knee OA stage progressed and to lay a foundation for an optimal treatment strategy to prevent knee malalignment. METHODS: A total of 106 knees of 81 patients ((men/women) 45/36; mean age 48.4 ±â€¯19.9 years; body mass index (BMI) 25.7 ±â€¯4.4 kg/m2) were enrolled in this cross-sectional study, comprising 34 (33/1) in Kellgren-Lawrence (KL) grade 0, 17 (8/9) in KL grade 1, 26 (5/21) in KL grade 2, 19 (4/15) in KL grade 3, and 10 (1/9) in KL grade 4. In all cases, computed tomography images were obtained with the subject in a reclined and relaxed position with the knee straight. Three-dimensional bone models were created from the images and knee alignment was calculated with six degrees-of-freedom. Then, 40 knees were selected consisting of 10 sex- and BMI-matched knees from each KL grade group: KL grade 1 (mean age 54.6 ±â€¯8.4 years; BMI 23.3 ±â€¯3.5 kg/m2), grade 2 (64.7 ±â€¯10.9 years; 27.3 ±â€¯3.2 kg/m2), grade 3 (69.2 ±â€¯11.4 years; 27.1 ±â€¯4.3 kg/m2), and grade 4 (71.9 ±â€¯9.2 years; 27.2 ±â€¯3.6 kg/m2). The Mann-Whitney U test with Bonferroni correction for multiple comparisons was used to analyze static alignment (α < 0.05/6). RESULTS: Alignment of the knee in flexion was -4.0 [95% confidence interval (CI): -6.4, -1.5] degrees, -3.4 [-8.0, 1.3] degrees, -0.1 [-3.7, 3.5] degrees, and 0.4 [-0.9, 1.6] degrees in the order of KL grade 1 to 4. There were significant differences between KL grade 1 and 4 (p = 0.0081). Anterior tibial translation was 6.6 [4.6, 8.6] mm, 5.8 [1.9, 9.7] mm, 1.0 [-2.5, 4.5] mm, and 1.3 [-2.4, 5.1] mm in the order of grade 1 to 4. There were significant differences between KL grade 1 and 4 (p = 0.0081). There were no significant differences in lateral tibial translation nor tibial rotation. CONCLUSIONS: The severely osteoarthritic knee joint was flexed and the tibia was displaced posteriorly with respect to the femur. Preventing these changes in alignment would assist in the prevention and treatment of knee OA.