Advances in modern osteotomies around the knee : Report on the Association of Sports Traumatology, Arthroscopy, Orthopaedic surgery, Rehabilitation (ASTAOR) Moscow International Osteotomy Congress 2017

Ten-year minimal follow-up of lateral opening wedge distal femoral osteotomy for lateral femorotibial osteoarthritis: Good survivorship and high patient satisfaction

PURPOSE

This study aimed (1) to determine complications and survival rates of lateral opening wedge distal femoral osteotomy (LOW-DFO) in the long term, (2) to assess their clinical outcomes in the long term and (3) to identify risk factors of failure.

METHODS

Between 1991 and 2011, 62 LOW-DFOs were performed in the same department. Inclusion criteria were all isolated LOW-DFO performed for isolated lateral tibiofemoral osteoarthritis and valgus malalignment, with a minimum 10-year follow-up. Thirty-eight patients were included, with a mean age of 48 ± 9 years. All patients had clinical and radiological assessments. The survival curves were calculated based on the following endpoints: unicompartmental or total knee arthroplasty.

RESULTS

The mean follow-up was 15.2 ± 4.4 [10-29] years. The mean preoperative mechanical FemoroTibial Axis (mFTA) was 188.8° ± 3.2° [184°-197°], primarily due to femur deformity (mean lateral distal femoral axis [LDFA] 83.2° ± 2.8°). Bone union was achieved in 89.5% of patients (n = 34) at a mean delay of 6.5 ± 6.7 months. The complication rate was 26% (five stiffness, one nonunion, three secondary displacements and one deep vein thrombosis). Nine revision surgeries (24%) were recorded. Survival rates at 5 and 10 years were 92.1% and 78.9%, respectively. The mean delay between DFO and total knee arthroplasty (TKA) was 11.6 ± 5.7 [1-27] years. Nineteen patients (50%) were free of TKA at the last follow-up. KSS scores were improved significantly. Return to sports was obtained in 92% of cases (n = 35), with a mean delay of 11 ± 8 months. Seventy-four per cent of patients were satisfied or very satisfied with the surgery. Eighty-four per cent would be willing to undergo the surgery again. Older age (p = 0.032) was a significant risk factor for TKA conversion.

CONCLUSION

LOW-DFO is an efficient procedure to manage lateral knee osteoarthritis in young patients with valgus deformity, with a good survival rate at 10 years and high patient satisfaction.

LEVEL OF EVIDENCE

Level III.

Influence of different standing positions on anatomical parameters of coronal whole-leg weight-bearing radiographs in preoperative planning for high tibial osteotomy

Purpose

The purpose of this study was to assess the differences in lower limb global alignment and anatomical parameters of coronal whole-leg radiographs, which were generally used in preoperative planning for high tibial osteotomy (HTO), according to different weight-bearing standing positions.

Methods

Between April 2021 and December 2022, 176 patients (60 males and 116 females) were investigated. Full-weight-bearing coronal whole-leg radiographs were obtained with the patella centred on the femoral condyle. Patients were divided by Kellgren-Lawrence grade (KL-0, KL-I, KL-II and KL-III) and assessed in two standing positions: legs closed and legs spread. Patients with flexion contractures or those unable to stand with full weight bearing were excluded. The mechanical distal femoral angle, medial proximal tibial angle (MPTA), femorotibial angle, joint line convergence angle, percentage weight-bearing line (%WBL) and hip-knee-ankle angle (HKAA) were measured. The Student's t test was used to compare the two standing positions. A p value < 0.05 indicated a statistically significant difference.

Results

The MPTAs of legs closed standing and legs spread standing were 84.9 ± 2.6° and 85.1 ± 2.4° in KL-0, 84.7 ± 2.0° and 84.9 ± 2.1° in KL-I and 85.0 ± 2.43° and 85.4 ± 2.4° in KL-II, respectively. There were statistically significant differences in the MPTA between the two standing positions in KL-0, KL-I and KL-II. In contrast, the %WBL and HKAA did not change regardless of the standing position. In the KL-III group, no statistical significance was observed for any of the anatomical parameters.

Conclusion

Several anatomical parameters were changed between the legs closed standing and the legs spread standing positions. It was suggested that the standing position should be taken into consideration in the planning for HTO.

Level of Evidence

Level IV, Case series with no comparison group.

Closing wedge high tibial osteotomy: An old-fashioned technique? Survival, clinical and radiological outcomes of a case series analysis

INTRODUCTION

Closing wedge high tibial osteotomy (CW-HTO) is a surgical option for active patients with medial knee pain and mild-moderate osteoarthritis with varus limb deformity. Despite its good reported results, this technique has been losing popularity. The aim of this study was to analyse the survival rate, clinical functional outcomes and radiological results of CW-HTO.

METHODS

It is a retrospective case series study. Seventy patients with primary knee osteoarthritis, operated on between 2010 and 2020 in a single Spanish tertiary hospital using the CW-HTO technique and with a minimum follow-up of 2 years were analysed.

RESULTS

Survival rate was 87,6% and 75,5% after a follow-up of 5 and 10 years respectively. Functional outcomes were good-to-excellent (KSS 77.7/100 and OKS 35.6/48) and good pain control (VAS 3.9/10) and high satisfaction (7.2/10) were achieved. Limb varus malalignment was significantly corrected (mean postoperative HKA angle 177,6° and MPTA 90,7°). However, 30% of patients presented hypocorrection, which was associated with inferior survival, functionality and satisfaction.

CONCLUSION

CW-HTO technique can be useful for patients with knee osteoarthritis and varus limb. It allows to correct varus malalignment while achieving good-to-excellent functional outcomes, good pain control, high patient satisfaction and acceptable medium-long term survival rate. However, it is associated with a non-negligible risk of hypocorrection or medial hinge disruption.

[Translated article] Closing wedge high tibial osteotomy: An old-fashioned technique? Survival, clinical and radiological outcomes of a case series analysis

INTRODUCTION

Closing wedge high tibial osteotomy (CW-HTO) is a surgical option for active patients with medial knee pain and mild-moderate osteoarthritis with varus limb deformity. Despite its good reported results, this technique has been losing popularity. The aim of this study was to analyse the survival rate, clinical functional outcomes and radiological results of CW-HTO.

METHODS

It is a retrospective case series study. Seventy patients with primary knee osteoarthritis, operated on between 2010 and 2020 in a single Spanish tertiary hospital using the CW-HTO technique and with a minimum follow-up of 2 years were analysed.

RESULTS

Survival rate was 87.6% and 75.5% after a follow-up of 5 and 10 years respectively. Functional outcomes were good-to-excellent (KSS 77.7/100 and OKS 35.6/48) and good pain control (VAS 3.9/10) and high satisfaction (7.2/10) were achieved. Limb varus malalignment was significantly corrected (mean postoperative HKA angle 177.6° and MPTA 90.7°). However, 30% of patients presented hypocorrection, which was associated with inferior survival, functionality and satisfaction.

CONCLUSION

CW-HTO technique can be useful for patients with knee osteoarthritis and varus limb. It allows to correct varus malalignment while achieving good-to-excellent functional outcomes, good pain control, high patient satisfaction and acceptable medium-long term survival rate. However, it is associated with a non-negligible risk of hypocorrection or medial hinge disruption.

Should I add orthobiologics to my knee osteotomy practice? A systematic review

IMPORTANCE

Orthobiologics has seen a renaissance over the last decade as an adjunct therapy during osteotomy due to the limited inherent regenerative potential of damaged intraarticular tissues.

AIM OR OBJECTIVE

This systematic review aims to present the latest evidence regarding using orthobiologics with simultaneous high tibial osteotomy (HTO) for knee osteoarthritis. The results of this study may guide surgeons to improve their clinical results and clear the air regarding confusion over whether or not to add orthobiologics to HTO in clinical practice backed by scientific evidence.

EVIDENCE REVIEW

According to PRISMA guidelines a systematic search for relevant literature was performed in the PubMed (MEDLINE), Scopus, EMBASE, and Cochrane Library databases of all studies published in English from January 1990 to May 2023. The following search terms were entered into the title, abstract, and keyword fields: "knee" or "osteotomy" AND "valgus" or "varus" AND "regenerative medicine" or "PRP" or "mesenchymal stem cells" or "stem cells" or "BMAC" or "bone marrow" or "growth factors" or "umbilical cord blood-derived mesenchymal stem cell" or "stromal vascular fraction". The AMSTAR-2 checklist was used to confirm the quality of the systematic review. Randomised controlled trials (RCTs), prospective and retrospective comparative cohort studies, case-control studies, and case series were included. Studies that reported clinical outcomes in patients treated with knee osteotomy for varus/valgus knee with concomitant adjunction of regenerative treatment [Platelet-rich plasma (PRP), Adipose-derived stem cells (ADSC), Human Umbilical Cord Blood-Derived (HUCBD), Mesenchymal Stem Cells (MSC), bone marrow aspirate concentrate (BMAC), stromal vascular fraction (SVF)] were included. The outcome measures extracted from the studies were the KOOS score, Lysholm score, Subjective IKDC, WOMAC Score, KSS, Tegner, HSS, radiographic tibiofemoral angle, posterior tibial slope and complications. The current systematic review is registered in the PROSPERO Registry (CRD42023439379).

FINDINGS

Osteotomy for unicompartmental arthritis with adjunction of orthobiologics such as PRP, ADSC, HVCBD, MSC, BMAC, and SVF presents a consistent statistically significant clinical improvement compared to preoperative scores regardless of the treatment modality used and there were no notable complications associated with the use of these novel agents.

CONCLUSIONS AND RELEVANCE

Orthobiologics and knee osteotomies could improve outcomes in patients with knee osteoarthritis desiring Knee preservation surgeries. However, only a few studies are available on the topic to conclude anything with certainty, the patients included in the studies could not be disintegrated based on the grade of osteoarthritis (OA), type, dosage and frequency of administration of orthobiologic and type of additional surgical procedures used. Therefore, better-structured RCTs are required to implement this finding into routine Orthopaedic practice.

LEVEL OF EVIDENCE

Level 4.

Magnetic resonance imaging-based bone imaging of the lower limb: Strategies for generating high-resolution synthetic computed tomography

This study aims at assessing approaches for generating high-resolution magnetic resonance imaging- (MRI-) based synthetic computed tomography (sCT) images suitable for orthopedic care using a deep learning model trained on low-resolution computed tomography (CT) data. To that end, paired MRI and CT data of three anatomical regions were used: high-resolution knee and ankle data, and low-resolution hip data. Four experiments were conducted to investigate the impact of low-resolution training CT data on sCT generation and to find ways to train models on low-resolution data while providing high-resolution sCT images. Experiments included resampling of the training data or augmentation of the low-resolution data with high-resolution data. Training sCT generation models using low-resolution CT data resulted in blurry sCT images. By resampling the MRI/CT pairs before the training, models generated sharper images, presumably through an increase in the MRI/CT mutual information. Alternatively, augmenting the low-resolution with high-resolution data improved sCT in terms of mean absolute error proportionally to the amount of high-resolution data. Overall, the morphological accuracy was satisfactory as assessed by an average intermodal distance between joint centers ranging from 0.7 to 1.2 mm and by an average intermodal root-mean-squared distances between bone surfaces under 0.7 mm. Average dice scores ranged from 79.8% to 87.3% for bony structures. To conclude, this paper proposed approaches to generate high-resolution sCT suitable for orthopedic care using low-resolution data. This can generalize the use of sCT for imaging the musculoskeletal system, paving the way for an MR-only imaging with simplified logistics and no ionizing radiation.

An Innovative Plate Concept for Rotational Guided Growth: A Porcine Pilot Study

Background Rotational deformities in children are currently treated with an osteotomy, acute de-rotation, and surgical fixation. Meanwhile, guided growth is now the gold standard in pediatric coronal deformity correction. This study aimed to evaluate the feasibility of a novel implant intended for rotational guided growth (RotOs Plate) in a large porcine animal model. Methodology A submuscular plate was inserted on the medial and lateral aspect of the distal femoral physis of the left femur in 6 pigs. Each plate was anchored with a screw in the metaphysis and epiphysis respectively. The plates were expected to rotate the femur externally. The right femur acted as a control in a paired design. The animals were housed for 12 weeks after surgery. MRI scanning of both femora was performed before euthanasia after 12 weeks. Rotation was determined as the difference in the femoral version on MRI between the operated and non-operated femur after 12 weeks. Results External rotation in all operated femurs was observed. The mean difference in the femoral version on MRI between operated and non-operated femurs was 12.5° (range 9°-16°). No significant changes in axial growth were detected. Conclusions This study shows encouraging results regarding rotational guided growth, which may replace current invasive surgical treatment options for malrotation in children. However, further studies addressing potential secondary deformities are paramount and should be carried out.

Early results of high tibial osteotomy versus combined arthroscopic surgery

Objective

To investigate the early effect of high tibial osteotomy (HTO) compared with combined arthroscopic surgery.

Methods

A retrospective study was conducted on patients who underwent HTO at The First Affiliated Hospital of Shandong First Medical University from January 2018 to January 2022. 138 patients (163 knees) with knee osteoarthritis (KOA) treated with HTO were selected. The medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), femoral tibial angle (FTA), hip-knee-ankle (HKA) angle, weight-bearing line (WBL) ratio of the knee joint, opening gap, opening angle, American Knee Society score (KSS), US Hospital for Special Surgery (HSS) score, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score were measured to determine the different effects between HTO and HTO combined with arthroscopic by logistic regression analysis.

Results

Patients with HTO combined with arthroscopic surgery have improved functional scores as well as imaging perspectives compared to preoperative. By multivariate logistic analysis, it was concluded that arthroscopic surgery and gender are influential factors in the outcome of HTO surgery. The postoperative KSS score was 2.702 times more likely to be classified as excellent in the HTO combined with arthroscopy group than in the HTO group [Exp (β) = 2.702, 95% CI (1.049-6.961), P = 0.039]; the postoperative KSS score was 0.349 times more likely to be classified as excellent in women than in men [Exp (β) = 0.349, 95% CI (0.138-0.883), P = 0.026].

Conclusion

Better results with HTO combined with arthroscopic surgery. HTO combined with arthroscopy is a better choice in the surgical treatment of KOA.

Biological intra-articular augmentation for osteotomy in knee osteoarthritis: strategies and results : A systematic review of the literature from the ESSKA Orthobiologics Initiative

PURPOSE

To assess whether there is evidence supporting the use of augmentation strategies, either cartilage surgical procedures or injective orthobiologic options, to improve the results of osteotomies in knees with osteoarthritis (OA).

METHODS

A systematic review of the literature was performed on the PubMed, Web of Science and the Cochrane databases in January 2023 on osteotomies around the knee associated with augmentation strategies (either cartilage surgical procedures or injective orthobiologic options), reporting clinical, radiological, or second-look/histological outcomes at any follow-up. The methodological quality of the included studies was assessed with the Coleman Methodology Score (CMS).

RESULTS

Out of the 7650 records identified from the databases, 42 articles were included for a total of 3580 patients and 3609 knees treated; 33 articles focused on surgical treatments and 9 on injective treatments performed in association with knee osteotomy. Out of the 17 comparative studies with surgical augmentation, only 1 showed a significant clinical benefit of an augmentation procedure with a regenerative approach. Overall, other studies showed no differences with reparative techniques and even detrimental outcomes with microfractures. Regarding injective procedures, viscosupplementation showed no improvement, while the use of platelet-rich plasma or cell-based products derived from both bone marrow and adipose tissue showed overall positive tissue changes which translated into a clinical benefit. The mean modified CMS score was 60.0 ± 12.1.

CONCLUSION

There is no evidence to support the effectiveness of cartilage surgical treatments combined with osteotomies in terms of pain relief and functional recovery of patients affected by OA in misaligned joints. Orthobiologic injective treatments targeting the whole joint environment showed promising findings. However, overall the available literature presents a limited quality with only few heterogeneous studies investigating each treatment option. This ORBIT systematic analysis will help surgeons to choose their therapeutic strategy according to the available evidence, and to plan further and better studies to optimize biologic intra-articular osteotomy augmentation.

LEVEL OF EVIDENCE

Level IV.

Double-level knee osteotomy accurately corrects lower limb deformity and provides satisfactory functional outcomes in bifocal (femur and tibia) valgus malaligned knees

PURPOSE

Double-level knee osteotomy (DLO) is a challenging procedure that requires precision in preoperative planning and intraoperative execution to achieve the desired correction. It is indicated in cases of severe varus or valgus deformities where a single-level osteotomy would yield significantly tilted joint line obliquity (JLO). This study aimed to evaluate the effectiveness of DLO in achieving accurate correction without compromising JLO, using patient-specific cutting guides (PSCGs), in cases of bifocal valgus maligned knees.

METHODS

A single-centre, retrospective analysis of prospectively collected data for a total of 26 patients, who underwent DLO by PSCGs for valgus malaligned knees, between 2015 and 2020. Post-operative alignment was evaluated and the delta for different lower limb0.05, not statistically significant (ns)). All KOOS subs alignment parameters was calculated; the hip-knee-ankle angle (ΔHKA), medial proximal tibial angle (ΔMPTA), and lateral distal femoral angle (ΔLDFA). At the two-year follow-up, changes in the KOOS sub-scores, UCLA scores, lower limb discrepancy (LLD), and mean time to return to work and sport were recorded. All intraoperative and postoperative complications were recorded. The Mann-Whitney U test with a 95% confidence interval (95% CI) was used to evaluate the differences between two variables; one-way ANOVA between more than two variables and the paired Student's t-test was used to estimate the evolution of functional outcomes.

RESULTS

The postoperative mean ΔHKA was 0.9 ± 0.9°, the mean ΔMPTA was 0.7 ± 0.7°, and the mean ΔLDFA was 0.7 ± 0.8° (all values with p > 0.05, not statistically significant (ns)). All KOOS subscore's mean values were improved to an extent two-fold superior to the reported minimal clinically important difference (MCID) (all with p < 0.0001). There was a significant increase in the UCLA score at the final follow-up (5.4 ± 1.5 preoperatively versus 7.7 ± 1.4, p < 0.01). The mean time to return to sport and work was 4.7 ± 1.1 and 4.3 ± 2.1 months, respectively. There was an improvement in Lower-limb discrepancy preoperative (LLD = 1.3 ± 2 cm) to postoperative measures (LLD = 0.3 ± 0.4 cm), ns. Complications were 2 femoral hinge fractures, 2 deep vein thromboses, 1 delayed tibial healing, and 1 hardware removal for hamstring irritation syndrome.

CONCLUSION

DLO is effective and safe in achieving accurate correction in bifocal valgus malaligned knees with maintained lower limb length and low complication rate with no compromise of JLO.

LEVEL OF EVIDENCE

III.

Gait analysis and knee kinematics before, and 6 and 18 months after corrective valgus osteotomy

BACKGROUND

The study objective was to assess clinical outcomes and gait biomechanics in patients after 6 and 18 months after varus deformity (VD) surgical correction at knee joint (KJ).

METHOD

The study included 20 patients with medial osteoarthritis (OA) of the knee of grade 2-3 and a VD of >4°. A total of 21 surgeries were performed on the patients. Full length weight bearing (FLWB) X-ray and KJ assessments were done using the KSS, KOOS and VAS scoring systems were obtained from all the patients. Biomechanical gait parameters were captured using an inertial sensor system at timepoints before, and 6 and 18 months after surgery. Temporal and kinematic parameters of walking were analyzed.

RESULTS

The radiological parameters showed a stable VD correction. According to the KOOS, KS and VAS scores, there was a moderate dynamic improvement in the operated knee function during the study. The biomechanical parameters remained virtually unchanged throughout the entire follow-up period. In the following year, there were some subjective improvements but without any significant changes in gait biomechanics or knee kinematics.

CONCLUSIONS

Thus, the main changes in the joint clinical condition and function occur in the first 6 months after surgery. According to the study data-assessments by VAS, KOOS, and KSS-there was a moderate clinical improvement during the long-term follow-up period, however, the biomechanical changes were minor.

Biomechanics optimisation of the laminoplasty groove size and position: A numerical study

BACKGROUND

This study is focused on the opening technique of the cervical vertebrae during laminoplasty which serves to substantially reduce the most severe adverse effects of the simple resection of posterior vertebral elements. This computational study aims to clarify by an optimisation approach what shape and position upon the lamina the groove should have.

METHODS

The computational model was developed in the computational software COMSOL Multiphysics 5.6a based on a computer tomography data obtained from the C4 vertebra. For finding the optimal minimum or maximum of a function (surface), optimisation algorithms are developed following the Nelder-Mead algorithm.

RESULTS

The reaction-opening force increases with a decreasing groove radius and an increasing position from the vertebra body. The created area increases with a decreasing groove radius and a decreasing position. As the opening happens mostly only above the groove, the opening area increases only in this location. Moreover, the von Mises stress peak value is almost twice as large as in the case of maximization of the opening area, which might result in breaking of the lamina as the thickness of the lamina would be reduced to its minimum.

CONCLUSION

The groove radius and position can affect the opening force and the opening area in case of double door laminoplasty. The opening force is highly influenced by the groove position and radius. The best position for placing the groove is in the middle of the lamina and the radius of the groove should be as large as possible.

Accuracy, inter- and intrarater reliability, and user-experience of high tibial osteotomy angle measurements for preoperative planning: manual planning PACS versus semi-automatic software programs

Purpose

To compare the accuracy, inter- and intrarater reliability, and user-experience of manual and semi-automatic preoperative leg-alignment measurement planning software for high tibial osteotomy (HTO).

Methods

Thirty patients (31 lower limbs) who underwent a medial opening wedge HTO between 2017 and 2019 were retrospectively included. The mechanical lateral distal femur angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), and planned correction angle were measured on preoperative long-leg full weight-bearing radiographs utilising PACS Jivex Review® v5.2 manual and TraumaCad® v2.4 semi-automatic planning software. Independent measurements were performed by four raters. Two raters repeated the measurements. Accuracy in the standard error of measurement (SEM), inter- and intrarater reliability, and user-experience were analysed. Additionally, measurements errors of more than 3° were remeasured and reanalysed.

Results

The SEMs of all measured varus malalignment angles and planned correction angle were within 0.8° of accuracy for both software programs. Measurements utilising the manual software demonstrated moderate interrater intraclass correlation coefficient (ICC)-values for the mLDFA and mMPTA, and an excellent interrater ICC-value for the correction angle (0.810, 0.779, and 0.981, respectively). Measurements utilising the semi-automatic software indicated excellent interrater ICC-values for the mLDFA, mMPTA, and correction angle (0.980, 0.909, and 0.989, respectively). The intrarater reliability varied substantially per angle, presenting excellent intrarater agreements by both raters (ICC >  0.900) for the correction angle in each software program as well as poor-to-excellent ICC-values for the mLDFA (0.282–0.951 and 0.316–0.926) and mMPTA (0.893–0.934 and 0.594–0.941) in both the manual planning and semi-automatic software. Regarding user-experience, semi-automatic software was preferred by two raters, while the other two raters had no distinctive preference. After remeasurement of five outliers, excellent interrater ICC-values were found for the mLDFA (0.913) and mMPTA (0.957).

Conclusions

Semi-automatic software outperforms the manual software when user-experience and outliers are considered. However, both software programs provide similar performance after remeasurement of the human-related erroneous outliers. For clinical practice, both programs can be utilised for HTO planning.

Level of evidence

Diagnostic study, Level III.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40634-022-00475-x.

Controlled rotation of long bones by guided growth: A proof of concept study of a novel plate in cadavers

Our novel plate design has been developed for controlled rotation of long bones by guided growth. The objective of this proof-of-concept study was to evaluate the precision of the rotation in the femur. Twelve cadaverous femora of six adults (right = 6, left = 6) underwent an osteotomy at the level of the physeal scar. The plates were inserted on each side of the distal femur. Growth was simulated by axial distraction of the bone segments. The femur was stabilized using a unilateral external fixator. Femoral torsion was assessed with computed tomography (CT) and with an electric goniometer before and after distraction. The obtained rotation was compared to the predicted rotation based on the dimension of the plate and the bone. All femora were rotated as intended. The mean obtained rotation was 26.3° (95% confidence interval [CI]: 23.5-29.0) and the mean predicted rotation was 28.2° (95% CI: 26.9-29.5) (p > 0.82). The mean axial distraction was 19.5 mm (95% CI: 17.7-21.3). The predicted rotation of the femora was similar to the obtained values on CT and by goniometer. The obtained rotation occurred as a result of an axial distraction of approximately 2 cm. This suggests a potential for controlled rotation of the femur based on the circumference of the bone and plate dimensions that occurs simultaneously with axial distraction. Clinical significance: These findings suggest a possible clinical application in the treatment of maltorsion in children by guided growth, where theplate design guides the bone into torsional axial growth correcting the deformity.

3D-printed Cutting Guides for Lower Limb Deformity Correction in the Young Population

BACKGROUND

Three-dimensional (3D) virtual surgical planning technology has advanced applications in the correction of deformities of long bones by enabling the production of 3D stereolithographic models, patient-specific instruments and surgical-guiding templates. Herein, we describe the implementation of this technology in young patients who required a corrective osteotomy for a complex 3-plane (oblique plane) lower-limb deformity.

PATIENTS AND METHODS

A total of 17 patients (9 males, average age 14.7 y) participated in this retrospective study. As part of preoperative planning, the patients' computerized tomographic images were imported into a post-processing software, and virtual 3D models were created by a segmentation process. Femoral and tibial models and cutting guides with locking points were designed according to the deformity correction plan. They were used for both planning and as intraoperative guides. Clinical parameters, such as blood loss and operative time were compared with a traditional surgical approach group.

RESULTS

All osteotomies in the 3D group were executed with the use intraoperative customized cutting guides which matched the preoperative planning simulation and allowed easy fixation with prechosen plates. Surgical time was 101±6.2 minutes for the 3D group and 126.4±16.1 minutes for the control group. The respective intraoperative hemoglobin blood loss was 2.1±0.2 and 2.5+0.3 g/dL.Clinical and radiographic follow-up findings showed highly satisfactory alignment of the treated extremities in all 3D intervention cases, with an average time-to-bone union (excluding 2 neurofibromatosis 1 patients) of 10.3 weeks (range 6 to 20 wk).

CONCLUSION

The use of 3D-printed models and patient-specific cutting guides with locking points improves the clinical outcomes of osteotomies in young patients with complex bone deformities of the lower limbs.

LEVEL OF EVIDENCE

Level III.

Mechanical Analysis and Clinical Application of Butterfly-Shaped Patellar Claw

Memory alloy patella claws for treating patella fractures have been used for more than 30 years with many desirable features including fast healing, quick recovery, and avoidance of top abrasion of Kirschner wires and other complications. However, there are many models and it is difficult to choose the accurate claw for the patient. In this study, a finite element model of the butterfly-shaped patellar claw made of shape memory alloy was established, its mechanical structure was analyzed, and its clinical application was monitored. We used Solidworks Simulation software for modeling and mainly analyzed the force of the compression ring of the butterfly-shaped patellar claw. Clinically, we chose a closed fresh patella fracture case. After finite element analysis, the maximum stress that the compression ring of the butterfly-shaped patellar claw can withstand is 568.1 MPa. In this range, it always has elastic deformation resistance. The butterfly-shaped patella claw is fixed on the patella and will not break when subjected to a maximum force of 150 N on the encircling arm, and at the same time, there will be no pressure failure due to plastic deformation. A total of 27 cases were clinically used for the assessment of the clinical efficacy of the newly designed butterfly-shaped patella claws. The average follow-up time was 15.5 months, and the average fracture healing time was 8-12 weeks. All patients can get out of bed with crutches within 2 to 3 days after surgery. Among them, there were 15 cases with excellent functional ratings, 10 cases with good ratings, 2 cases with acceptable ratings, and no cases with poor ratings. The designed butterfly-shaped patella claws can provide an effective method for the treatment of patella fractures.

EXCESSIVE HYPERCORRECTION AFTER OPEN WEDGE HIGH TIBIAL OSTEOTOMY

Introduction Currently there is a tendency of increasing the proportion of knee joint organ-preserving surgery. High tibial osteotomy (HTO) was recommended as a method of knee joint varus deformity treating in cases with extraarticular deformity. The question of necessary angle correction remains controversial, which does not harm biomechanics of knee and adjacent joints. And the issue of preventing excessive hypercorrection as a complication of osteotomy. Methods The clinical case of the 59-year-old patient who underwent primary HTO and revision HTO is analyzed in this article. The patient had a varus deformity of a left lower limb with isolated medial knee osteoarthritis. The patient complained only at pain and range of motion limitation in the knee joint. According to arthroscopy and magnetic resonance imaging (MRI) data, there was cartilage damage classified as Outerbridge 4 stage of the medial compartment. There were no signs of lateral compartment cartilage damage and patellofemoral joint arthritis. The patient's body mass index (BMI) was 28kg / m2. Varus deformity of the knee joint 10˚. Results The patient underwent a medial high tibial open wedge osteotomy. During preoperative planning topograms of the lower limb with a weight bearing were used. A clinical result before the operation according to the scales was: Knee injury and Osteoarthritis Outcome Score (KOOS) 46 points, Visual Analogue Scale (VAS) 7 cm., American Orthopaedic Foot and Ankle Society (AOFAS) 92 points. After 6 months from initial surgery: knee joint VAS 1 cm., ankle joint VAS 5 cm., KOOS 88 points, AOFAS 63 points. During clinical examination and according to instrumental studies, excessive valgus hypercorrection of the 11,2˚ noted. Also, tibial plafond inclination (TPI) and talar inclination (TI) significantly increased. 1,5 years after the primary osteotomy, a revision closed wedge osteotomy was performed. Valgus deformity of the knee joint became 3˚, axis of the ankle joint changed to normal values. Clinical and functional results after 6 months after revision osteotomy: KOOS 92 points, AOFAS 99 points, pain in the knee and ankle joint on the VAS scale 1 cm. Conclusions The case showed: careful preoperative planning before the operation and using of additional methods for monitoring intraoperative correction were important. Excessive valgus hypercorrection promotes good regeneration of the medial compartment cartilage, however it overloads a lateral compartment and adversely affects the ankle joint and foot.

A 2021 consensus statement on osteotomies around the knee by the UK Knee Osteotomy consensus Group (KOG)

BACKGROUND

There are significant deficiencies in the evidence base of modern-day osteotomy which result in significant variation in practice between surgeons. The purpose of this statement was to develop a consensus statement on the practice of osteotomy so that a more standardized approach to the indications, surgical technique, and postoperative care could be outlined. The article is also intended to educate and inform the practice of individuals who are early in their experience and/or clinical practice.

METHOD

A group of 29 specialist knee surgeons who regularly perform osteotomy was convened to form the Knee Osteotomy consensus Group (KOG). Consensus was determined utilizing the consensus group technique described by List. A total of 37 questions were asked covering all aspects of clinical practice.

RESULTS

20 statements were generated and debated until a criterion level of 70% was met.

CONCLUSIONS

Consensus was achieved regarding 20 statements concerning Indications for surgery, decision making, surgical planning, technique, post-operative assessment and recovery.

Tranexamic acid is beneficial for blood management of high tibial osteotomy: a randomized controlled study

INTRODUCTION

The purpose of this study was to investigate whether TXA can effectively reduce blood loss after HTO and related complications and to evaluate its safety.

MATERIALS AND METHODS

From March 2016 to March 2018, 100 patients who underwent medial opening wedge HTO in the Department of Orthopedics, the second affiliated hospital of xi'an jiaotong university, with an average age of 52.8 ± 3.2 years, were randomly divided into the TXA group (using intravenous TXA) and the control group (using the same amount of normal saline), with 50 patients in each group. The postoperative wound drainage volume, decrease in hemoglobin and hematocrit value, total blood loss, wound healing, blood transfusion, deep venous thrombosis (DVT) and pulmonary embolism (PE) were compared between the two groups.

RESULTS

The drainage volume on the first postoperative day and the total drainage volume of the TXA group were significantly lower compared with those of the control group (145.7 vs 264.5 ml, 282.3 vs 413.2 ml, P < 0.05). The decreases in the hemoglobin and hematocrit values on the postoperative first, second and fifth days were lower in the TXA group than those in the control group (1.4 VS 3.5, 2.6 vs 3.3, 1.9 vs 2.9 g, P < 0.05; 3.3 vs 5.5, 5.0 vs 9.1, 3.8 vs 7.2%, P < 0.05), and the mean total blood loss was also lower in the TXA group than that in the control group (477.9 vs 834.6 ml, P < 0.05). In the control group, 1 patient had wound hematoma requiring additional paracentesis and pressure dressing, 1 patient had superficial wound infection requiring additional debridement, and 1 patient had postoperative blood transfusion compared to none in the TXA group (P > 0.05). There was no symptomatic DVT or PE in either of the groups.

CONCLUSION

Intravenous TXA can effectively and safely reduce blood loss and bleeding-related complications after HTO and was beneficial for the blood management of HTO.

Focal cartilage defects of the lateral compartment do influence the outcome after high tibial valgus osteotomy

INTRODUCTION

High tibial medial open-wedge valgus osteotomy (HTO) is a well-established procedure for unicompartimental medial osteoarthritis of the young and active patient. However, the influence of cartilage defects of the lateral compartment on the total outcome remains obscure.

METHODS

From 2005 to 2012, a total of 63 patients underwent HTO for medial osteoarthritis of the knee at a single university orthopaedic center. Baseline data as well as intraoperative findings, including the grade and location of cartilage lesions, were evaluated retrospectively. Two groups were formed regarding the integrity of the lateral tibiofemoral compartment as measured by the Outerbridge score (group A: no lateral cartilage defects, group B: mild to moderate lateral cartilage defects). Functional outcome was assessed using the Knee and Osteoarthritis Outcome Score (KOOS), including its five subscores.

RESULTS

Comparing pre- and postoperative data, we identified an overall benefit of the HTO procedure as measured by the KOOS. Group A (no lateral cartilage defects) showed an increase in all five KOOS subscores (p = 0.00-0.01), whereas for group B (mild to moderate lateral cartilage defects), only two KOOS subscores revealed a significant increase (p = 0.03-0.04). There was also a statistically significant difference in the total KOOS score with higher values for group A at the postoperative visit. Cartilage defects with a higher Outerbridge score were associated with lower postoperative KOOS subscores.

DISCUSSION

Mild to moderate cartilage defects of the lateral compartment humble the total outcome after HTO procedure. Thus, indication for HTO should be made very carefully if any degree of lateral cartilage degeneration is present.

Contemporary Knee Osteotomy in the United States: High Tibial Osteotomy and Distal Femoral Osteotomy Have Comparable Complication Rates despite Differing Demographic Profiles

Knee osteotomies show efficacy in slowing knee osteoarthritis progression and delaying the need for total knee arthroplasty in younger patients. Despite evolutions in indications, techniques, and hardware that have improved outcomes, longitudinal trends demonstrate a decline in high tibial osteotomy (HTO) and distal femoral osteotomy (DFO) use. Unfortunately, knowledge of the current usage and complications associated with HTO and DFO is limited. The purpose of this study was to compare the preoperative demographics and early complication rates of HTO and DFO. We analyzed the HTOs and DFOs performed between 2006 and 2017 using the ACS-NSQIP (American College of Surgeons National Surgical Quality Improvement Program) database. We compared both groups for preoperative patient demographics (sex, age, race, body mass index [BMI]) and health status variables including functional scores, ASA (American Society of Anesthesiologists) scores, smoking status, and other comorbidities. Emergency and elective status of the patient case, length of hospital stay, operation time, and 30-day postoperative complications were also analyzed. After the exclusion criteria were applied, 321 HTO and 295 DFO patients were included in the final analysis. The HTO group had higher proportions of younger (p < 0.001) and male (p < 0.001) patients with higher BMI (p = 0.007). Racial profiles were similar between the two groups (p = 0.575). Preoperatively, those in the HTO group had more functional independence, better physical status scores, and fewer chronic conditions (p < 0.05). There were no statistically significant differences between HTO and DFO in operative time, postoperative complications, readmission, and reoperation. HTO patients, however, had shorter hospital stays (p < 0.001). Although there are differences in preoperative and operative characteristics of HTO and DFO, early postoperative complications are similar for both groups. Therefore, HTO and DFO can be considered safe and effective treatment options for younger patients with symptomatic unicompartmental knee osteoarthritis.

Alignment adjustment using the Valgus stress technique can increase the surgical accuracy of novice surgeons during medial opening-wedge high Tibial osteotomy

Background

The purpose of this study was to compare the degree of accuracy of coronal alignment correction with use of the “alignment adjustment under valgus stress technique” between expert and novice surgeons during medial opening-wedge high tibial osteotomy (MOWHTO).

Methods

Forty-eight patients who underwent MOWHTO performed by an expert surgeon (expert group) and 29 by a novice surgeon (novice group) were enrolled in analysis. During surgery, lower-extremity alignment was corrected using the “alignment adjustment under valgus stress technique”. Normocorrection was defined as a weight-bearing line ratio between 55 and 70% and the correction accuracy was compared between expert and novice groups using the ratio of normocorrection to outliers. The clinical outcomes were also compared using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at 1 year after surgery.

Results

The undercorrection rate was 14.6% in the expert group and 13.8% in the novice group, while the overcorrection rate was 2.1% in the expert group and 3.4% in the novice group. In the ratio of normocorrection to outliers, no difference was found between the two groups at the one-year follow-up visit (83.3% in the expert group vs. 82.8% in the novice group; p > 0.05). Also, no significant differences were seen in WOMAC subscores immediately preoperatively and at 1 year after surgery (all p > 0.05).

Conclusion

Adhering to the “alignment adjustment under valgus stress technique” protocol enabled novice surgeons to achieve similar surgical accuracy as that of an expert surgeon in coronal alignment during MOWHTO.

Level of evidence

Level III.

Identification of Candidate Synovial Fluid Biomarkers for the Prediction of Patient Outcome After Microfracture or Osteotomy

BACKGROUND

Biomarkers are needed to predict clinical outcomes for microfracture and osteotomy surgeries to ensure patients can be better stratified to receive the most appropriate treatment.

PURPOSE

To identify novel biomarker candidates and to investigate the potential of a panel of protein biomarkers for the prediction of clinical outcome after treatment with microfracture or osteotomy.

STUDY DESIGN

Descriptive laboratory study.

METHODS

To identify novel candidate biomarker proteins, we used label-free quantitation after liquid chromatography-tandem mass spectrometry of dynamic range-compressed synovial fluids (SFs) from individuals who responded excellently or poorly (based on change in Lysholm score) to microfracture (n = 6) or osteotomy (n = 7). Biomarkers that were identified in this proteomic analysis or that relate to osteoarthritis (OA) severity or have predictive value in another early OA therapy (autologous cell implantation) were measured in the SF of 19 and 13 patients before microfracture or osteotomy, respectively, using commercial immunoassays, and were normalized to urea. These were aggrecanase-1 (ADAMTS-4), cartilage oligomeric matrix protein (COMP), hyaluronan (HA), lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1), matrix metalloproteinase 1 and 3, soluble CD14, S100 calcium binding protein A13, and 14-3-3 protein theta (YWHAQ). Levels of COMP and HA were also measured in the plasma of these patients. To find predictors of postoperative function, multivariable regression analyses were performed.

RESULTS

Proteomic analyses highlighted YWHAQ and LYVE-1 as being differentially abundant between the clinical responders/improvers and nonresponders after microfracture. A linear regression model after backward variable selection could relate preoperative concentrations of SF proteins (HA, YWHAQ, LYVE-1), activity of ADAMTS-4, and patient demographic characteristics (smoker status and sex) with Lysholm score 12 months after microfracture. Further, a generalized linear model with elastic net penalization indicated that lower preoperative activity of ADAMTS-4 in SF, being a nonsmoker, and being younger at the time of operation were indicative of a higher postoperative Lysholm score (improved joint function) after osteotomy surgery.

CONCLUSION

We have identified biomarkers and generated regression models with the potential to predict clinical outcome in patients treated with microfracture or osteotomy of the knee.

CLINICAL RELEVANCE

Candidate protein biomarkers identified in this study have the potential to help determine which patients will be best suited to treatment with microfracture or osteotomy.

Supercapsular percutaneously-assisted total hip (SuperPath) versus mini-incision posterolateral total hip arthroplasty for hip osteoarthritis: a prospective randomized controlled trial

Background

Supercapsular percutaneously-assisted total hip (SuperPath) arthroplasty has been proposed to be minimally invasive and tissue sparing, with possible superior postoperative outcomes compared with conventional approaches for total hip arthroplasty (THA). However, previous studies have underlined the shortcomings of conventional THA approaches, including higher dislocation, more blood loss, longer incisions, more tissue damage, and delayed postoperative rehabilitation. In the present study, we compared the short-term outcomes of unilateral THA with those of SuperPath and the mini-incision posterolateral approach (PLA) for hip osteoarthritis (OA).

Methods

Patients with unilateral hip OA were prospectively recruited and underwent either SuperPath (SuperPath group) or mini-incision PLA THA (PLA group). Perioperative status [operative time, incision length, intraoperative blood loss, soft tissue damage, and length of hospital stay (LOS)], and postoperative function outcomes, including range of motion (ROM), pain visual analog scale (VAS), and Harris Hip Score (HHS), were evaluated and compared between the groups at scheduled time points within 12 months postoperatively.

Results

Compared with the PLA group, the SuperPath group yielded a significantly shorter incision length (7.83 vs. 12.45 cm, P<0.001), longer operative time (102.72 vs. 66.22 min, P<0.001), more blood loss (1,007.38 vs. 844.55 mL, P=0.005), and more soft tissue damage (creatine kinase: 1,056.05 vs. 821.50 U/L, P=0.006) on postoperative day 3. The SuperPath group also showed deficient acetabular cup positioning (abduction angle: 36.94° vs. 42.66°, P=0.004) and a greater decrease in ROM (flexion: 107.66° vs. 114.44°, P=0.004; 109.83° vs. 116.11°, P=0.002; 111.66° vs. 118.88°, P<0.001) on postoperative days 1, 3, and 14, as well as severe early-term pain symptoms (pain VAS on postoperative day 3: 7.05 vs. 6.55, P=0.041). However, the LOS, C-reactive protein levels, erythrocyte sedimentation rate (within 2 weeks postoperatively), and HHS were comparable between the groups during the 12 months postoperatively.

Conclusions

SuperPath may be a promising, minimally invasive technique for the treatment of OA in the future. Further investigation is necessary to evidence the possible superiority of SuperPath over other conventional mini-incision THA approaches.

Inhalational versus intravenous maintenance of anesthesia for quality of recovery in patients undergoing corrective lower limb osteotomy: A randomized controlled trial

BACKGROUND

Inhalational anesthesia and propofol-based total intravenous anesthesia (TIVA) are the two most popular methods of general anesthesia with distinct characteristics that may affect quality of recovery (QOR) differently. This study compared QOR after corrective lower limb osteotomy between desflurane-based inhalational anesthesia and propofol-based TIVA.

METHODS

Sixty-eight patients, ASA class I or II who underwent corrective lower limb osteotomy were randomized to receive either desflurane anesthesia or propofol TIVA. The primary outcome was quality of recovery 40 (QoR-40) questionnaire scores on postoperative day (POD) 1 and 2. Postoperative nausea scores, antiemetic requirements, and amount of opioid consumption via intravenous patient-controlled analgesia (IV PCA) were assessed as secondary outcomes.

RESULTS

Global QoR-40 scores on POD 1 (153.5 (140.3, 171.3) vs. 140.0 (120.0, 173.0), P = 0.056, 95% CI; -22.5, 0.2) and POD 2 (155.5 (146.8, 175.5) vs. 152.0 (134.0, 179.0), P = 0.209, 95% CI; -17.5, 3.9) were comparable between the two groups. Among the five dimensions of QoR-40, physical independence scores were significantly higher in the TIVA group compared to the Desflurane group on POD both 1 and 2. Nausea scores (0.0 (0.0, 0.0) vs. 1.0 (0.0, 3.5), P < 0.001) and number of patients requiring rescue antiemetics (0% vs. 15.2%, P = 0.017) were significantly lower in the TIVA group at the post anesthesia care unit (PACU). Although the number of bolus attempts between 0-24 h and the morphine equivalent dose of analgesics administered via IV PCA between 12-24 h were significantly less in the TIVA group compared to the Desflurane group, there was no significant difference between groups for the overall 48 h postoperative period.

CONCLUSIONS

Propofol-based TIVA did not improve global QoR-40 scores compared with desflurane-based inhalational anesthesia. However, considering the better QoR-40 scores in the domain of physical independence and less nausea in the early postoperative period, propofol TIVA should be considered as a useful option in patients undergoing corrective lower limb osteotomy.

Osteotomy around the knee: Assessment of quality, content and readability of online information

BACKGROUND

As knee osteotomy surgery becomes increasingly accessible, more patients may turn to the Internet for information. This study examined the source, quality, content and readability of online information regarding osteotomy around the knee.

METHODS

The first 70 websites returned by the top four search engines were identified using the key words: "knee osteotomy" and "high tibial osteotomy." The websites were categorised by type and assessed using the DISCERN score, Journal of the American Medical Association (JAMA) benchmark criteria and a novel Knee Osteotomy-Specific Score (KOSS). The presence of the Health On the Net (HON) code accreditation seal was noted. Readability of each website was assessed using eight readability formulae. The mean reading grade level (RGL) was compared to the 6th and 8th grade reading levels. The mean RGL of each category was also compared.

RESULTS

Of the 45 unique websites analysed, the majority were Physician (33%) and Journal websites (31%). The mean DISCERN score was 36.7 (±8.9) which is classified as 'poor.' The mean JAMA benchmark criteria score was 2.04 (±1.5) and Physician websites were most likely to be scored zero. The mean KOSS was 15.4 (±5.7). The highest scoring website was a Commercial site but, overall, Journal category sites provided the best quality information. Websites that bore the HONcode seal obtained higher DISCERN, JAMA benchmark criteria and Knee Osteotomy - Specific Scores. The cumulative mean RGL was 13.2 (±2.2) which exceeded the 6th grade level by an average of 7.2 grade levels and the 8th grade level by an average of 5.2 grade levels. No website (0%) was written at or below either the 6th or the 8th grade reading levels. The mean Flesch Reading Ease Score of all websites was 41.13 (±14.7) which is classified as 'difficult.' Journal websites had the highest RGL.

CONCLUSION

The information available online regarding osteotomy around the knee varies tremendously in quality and completeness. Physician sites predominate, but these were among the lowest scoring of all websites. Even where high quality information is available, it is set at too high a level to be easily understood.

LEVEL OF EVIDENCE

Survey of materials - Internet.

High Tibial Osteotomy for Genu Varum in Adults: Do Proprietary Implants Limit the Quality of Correction?

The surgical technique of proximal tibial osteotomy for genu varum in adults has evolved from a procedure using closing wedges of estimated sizes with staple fixation in the 1960s to using standard trauma internal fixation implants and, more recently, to gradual correction with software-guided hexapod external fixators. In the last two decades, implant manufacturers have also produced anatomical implants specific for such corrective osteotomies. This study evaluates the limits of using such proprietary implants for proximal tibial osteotomy in genu varum.

Materials and methods

Scanograms (teleradiograms) of lower limbs of a patient were used to derive skiagrams (two-dimensional bony outlines of the extremities). From these, two-dimensional and three-dimensional models of varus deformities of the tibia with different values of mechanical medial proximal tibial angle (mMPTA, from 85° to 40°) were created. An analysis of the created deformity was carried out and a simulation for surgical correction was performed using an open wedge high tibial osteotomy with fixation using a proprietary (Tomofix, Synthes) implant. In addition, a 3D simulation technique was used to check the accuracy of the results obtained from the 2D simulation.

Results

In cases of mMPTA ≥80° with localisation of the apex of varus deformity at the level of the knee joint line, the standard technique used with the proprietary medial tibial plate produces good results.In cases of mMPTA ≤70°, fixation of the osteotomised fragments by the proprietary medial plate is poor owing to the anatomical contours of the implant. In these cases, a different type of osteosynthesis is needed.In cases of mMPTA ≤70°, the distance between the lower edge of the bone plate and the medial surface of the tibia after a proximal tibial osteotomy exceeds 11 mm and will result in unacceptable soft tissue tension around the implant.Mechanical axis deviation to the Fujisawa point produces mMPTA values outside the reference range of normal values.

Conclusion

An osteotomy of the proximal tibia using a prescribed technique linked to a proprietary implant achieves good results only if performed within a certain range of deformity values. Pronounced varus deformities require a fundamentally different approach. This study reveals that surgeons undertaking corrective proximal tibial osteotomies for genu varum need to perform a comprehensive analysis of the deformity to allow for appropriate selection of patients. This will enable a consideration of the size and other characteristics of the deformity that will reduce the technical complications that may arise if the correction was performed using the recommended technique linked to a proprietary implant.

How to cite this article

Solomin LN, Chugaev DV, Filippova AV, e t a l. High Tibial Osteotomy for Genu Varum in Adults: Do Proprietary Implants Limit the Quality of Correction? Strategies Trauma Limb Reconstr 2020;15(1):13-22.

[Management principle and clinical suggestions of osteotomy gap of opening wedge high tibial osteotomy]

OBJECTIVE

To summarize the management principle and clinical suggestions of the osteotomy gap of opening wedge high tibial osteotomy (OWHTO).

METHODS

The related literature of the osteotomy gap of OWHTO in recent years was reviewed, summarized, and analyzed.

RESULTS

Delayed union and non-union of the osteotomy gap are main complications of OWHTO. Tomofix plate, as locking steel plate, has the characteristics of angular stability and can better maintain the stability of the osteotomy gap, promote bone healing, and avoid loss of correction. There are some treatment options for the osteotomy gap site, such as, without bone, autologous bone graft, allogeneic bone graft, bone substitute materials graft, and augment factor graft to enhance bone healing. When the osteotomy gap is less than 10 mm, it achieves a good outcome without bone graft. For the obesity, lateral hinge fracture, large osteotomy gap, or correction angle more than 10°, the bone graft should be considered. In cases whose osteotomy gap is nonunion or delayed union, the autologous bone graft is still the gold standard. When the osteotomy gap repaired with the allogeneic bone graft, it is better to choose fragmented cancellous or wedge-shaped cancellous bone, combining with the locking plate technology, also can achieve better bone union. The bone substitute material of calcium-phosphorus is used in the osteotomy gap, which has the characteristics of excellent bone conduction, good biocompatibility, and resorption, combining with the locking plate technology, which can also achieve better bone union in the osteotomy gap. The augment factors enhance the bone healing of the osteotomy gap of OWHTO is still questionable. The bone union of the osteotomy gap is also related to the size of the osteotomy gap and whether the lateral hinge is broken or not.

CONCLUSION

No matter what type of materials for the osteotomy gap, OWHTO can improve the function and relieve pain for knee osteoarthritis. More randomized controlled trials are needed to provide evidence for clinical decision to determine which treatment option is better for the osteotomy gap of OWHTO.

Recent Trends, Technical Concepts and Components of Computer-Assisted Orthopedic Surgery Systems: A Comprehensive Review

Computer-assisted orthopedic surgery (CAOS) systems have become one of the most important and challenging types of system in clinical orthopedics, as they enable precise treatment of musculoskeletal diseases, employing modern clinical navigation systems and surgical tools. This paper brings a comprehensive review of recent trends and possibilities of CAOS systems. There are three types of the surgical planning systems, including: systems based on the volumetric images (computer tomography (CT), magnetic resonance imaging (MRI) or ultrasound images), further systems utilize either 2D or 3D fluoroscopic images, and the last one utilizes the kinetic information about the joints and morphological information about the target bones. This complex review is focused on three fundamental aspects of CAOS systems: their essential components, types of CAOS systems, and mechanical tools used in CAOS systems. In this review, we also outline the possibilities for using ultrasound computer-assisted orthopedic surgery (UCAOS) systems as an alternative to conventionally used CAOS systems.