Proximal tibial osteotomy. A critical long-term study of eighty-seven cases

Three-dimensional analysis of lateral cortical hinge in medial open-wedge high tibial osteotomy: A computational simulation study of adult cadavers

PURPOSE

The objective of this study was to improve the three-dimensional (3D) understanding of optimal lateral cortical hinge in medial open-wedge high tibial osteotomy (MOWHTO) via a computational cadaveric simulation of actual size.

METHODS

The computed tomography data of 117 adult cadavers were imported into Mimics® software to design 3D models of tibia and fibula. To simulate the MOWTHO, a virtual cutting plane was developed inside the safe zone based on established landmarks. After splitting and distracting through the cutting plane, the 10-mm cylinder (Ø 30 mm; height 10 mm) was placed vertically to be occupied properly in the nonosteotomized lateral cortex. The cross points between the round cylinder and cutting plane represented the anterior and posterior hinge points, which were used to validate the 3D position and direction of cortical hinge.

RESULTS

A 10-mm cylinder did not violate the proximal tibiofibular joint (PTFJ) and the protruding segment of the condylar area was less than 2 mm in 115 models. The connecting line between anterior and posterior hinge points was an average of 12.1° (range 0-24.1°, SD 4.64) to the lateral side. In the nonoverlapping anteroposterior projection between proximal fibula and tibia, the posterior hinge point was laid over the PTFJ as close as possible. Based on free 360° rotation and magnification without any tilt, no posterior cortical disruption of PTFJ was observed while securing a minimum width of 10 mm.

CONCLUSION

If the posterior hinge point was placed immediately above the PTFJ without involvement, the nonosteotomized portion carried sufficient width greater than 10 mm, despite lateral rotation at an average hinge direction of 12.1°.

The Effect of Cartilage Lesion in the Lateral Compartment of the Knee on the Surgical Outcome of Medial Open-Wedge High Tibial Osteotomy

The aim of this study was to identify the effect of cartilage lesion in the lateral compartment of the knee on the surgical outcome of medial open-wedge high tibial osteotomy (MOWHTO). A total of 172 consecutive patients who underwent MOWHTO were evaluated retrospectively. Among the patients who underwent second-look arthroscopic assessment, 30 patients with lateral compartment cartilage lesion (group 1: ≥ grade 2 cartilage lesion according to the International Cartilage Repair Society [ICRS] grading system) and 64 patients with normal or near-normal lateral compartment cartilage (group 2: grade 0 or 1 cartilage lesion according to the ICRS grading system) were included in the analysis. Each patient was evaluated for the following variables: clinical scores, radiographic osteoarthritis grade, and comparative measurement under arthroscopy. All clinical scores were similar between the two groups preoperatively and at the time of second-look operation. Group 1 showed a significantly higher osteoarthritis grade in the lateral compartment of the knee on the 30 degree flexed posteroanterior view according to the International Knee Documentation Committee grading system preoperatively (p = 0.005) and at the time of second-look operation (p = 0.002). In regard to the comparative measurement under arthroscopy, the size of cartilage lesion on the medial compartment decreased by time in both groups (p = 0.000), whereas the size of cartilage lesion on the lateral compartment increased by time in both groups (p = 0.004). However, the degree of change in the cartilage lesion size in each compartment of the knee over time did not significantly differ between the two groups. Regarding the cartilage lesion grade in the lateral compartment, there was no statistically significant difference in the frequency of deterioration between the two groups. As a result, the presence of cartilage lesion of ICRS grade 2 or 3 in the lateral compartment of the knee, either subtle or not detected during the preoperative evaluation, would not affect the surgical outcome of MOWHTO. This is a Level IV, therapeutic case series study.

Differences in preoperative planning for high-tibial osteotomy between the standing and supine positions

Introduction

Previous studies have reported that alignment changes depend on the patient’s position in orthopedic surgery. However, it has not yet been well examined how the patient’s position affects the preoperative planning in high-tibial osteotomy (HTO). Therefore, the aim of this study was to investigate the effects of the patient’s position on preoperative planning in HTO.

Materials and methods

A total of 60 knees in 55 patients who underwent HTO were retrospectively examined. Virtual preoperative planning for medial open-wedge HTO (OWHTO), lateral closed-wedge HTO (CWHTO), and hybrid CWHTO were performed by setting the percentage of the weight-bearing line (%WBL) at 62% as an optimal alignment. The correction angle differences between the supine and standing radiographs were measured. The virtual %WBL (v%WBL) was determined by applying the correction angle obtained from the standing radiograph to the supine radiograph. The %WBL discrepancy (%WBLd) was calculated as v%WBL − 62 (%) to predict the possible correction errors during surgeries. A single regression analysis was performed to examine the correlation between the correction angle difference and %WBLd.

Results

The mean correction angle was significantly higher when the preoperative planning was based on standing radiographs than when based on supine radiographs (P < 0.001), and the mean difference was 2.2 ± 1.5°. The difference between the two conditions in the medial opening gaps for OWHTO, lateral wedge sizes (mm) for CWHTO, and hybrid CWHTO were 2.6 ± 2.0, 2.3 ± 1.6, and 1.9 ± 1.4, respectively. The mean v%WBL was 71.2% ± 7.3%, and the mean %WBLd was 10.1% ± 7.4%. A single regression analysis revealed a linear correlation between the correction angle difference and %WBLd (%WBLd = 4.72 × correction angle difference + 0.08). No statistically significant difference in the parameters was found between the supine and standing radiographs postoperatively.

Conclusions

We found significant differences in the estimated correction angles between the supine and standing radiographs in the planning for HTO. Therefore, surgeons should carefully consider the difference between supine and standing radiographs and estimate the possible correction error during surgery when planning a HTO.

An Increase in Medial Joint Space Width After Medial Open-Wedge High Tibial Osteotomy Is Associated With an Increase in the Postoperative Weight-Bearing Line Ratio Rather Than With Cartilage Regeneration: Comparative Analysis of Patients Who Underwent Second-Look Arthroscopic Assessment

PURPOSE

To investigate relevant factors influencing increases in medial joint space width (JSW) after medial open-wedge high tibial osteotomy (MOWHTO).

METHODS

Between January 2010 and December 2018, the electronic medical records of consecutive patients who underwent MOWHTO and subsequent second-look arthroscopic assessment at least 12 months after MOWHTO were retrospectively evaluated. The patients were classified into 2 groups according to changes in the medial JSW of the knee at the time of the second-look operation compared with that at baseline before the initial surgical procedure. Various radiographic parameters, arthroscopic findings, and clinical scores were compared between the groups, and regression analysis was performed to identify factors related to increases in medial JSW.

RESULTS

A total of 114 patients were analyzed. In a bivariate analysis, patients who experienced an increase in medial JSW showed a significantly higher postoperative weight-bearing line ratio (WBLR) (P = .008) and a greater proportion of severe preoperative cartilage lesions in the medial compartment of the knee compared with patients with a maintained or reduced medial JSW (P = .035). In terms of clinical scores, patients with an increased medial JSW showed relatively favorable clinical outcomes at the time of the second-look operation. Regression analysis indicated only postoperative WBLR as a relevant factor associated with an increase in medial JSW after MOWHTO (odds ratio, 1.057; P = .01). Additional analysis with patients reclassified according to the postoperative WBLR showed that as the postoperative WBLR increased, the medial JSW increased, without a significant change in the lateral JSW.

CONCLUSIONS

An increase in the medial JSW of the knee joint after MOWHTO appears to be associated with an increase in the postoperative WBLR, not with cartilage regeneration. Obtaining adequate correction so that the postoperative WBLR is within 60% to 70% would be desirable in terms of postoperative changes in the medial JSW, as well as clinical outcomes.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Impact of medial open-wedge high tibial osteotomy for medial compartment osteoarthritis of the knee

BACKGROUND

Most populations worldwide, who are used to squatting and sitting cross-legged for their activities of daily living, largely comprise the lower socioeconomic strata, thus making them candidates for exclusion for total knee arthroplasty. Proximal/high tibial osteotomy (HTO) is a preferred strategy for clinically symptomatic osteoarthritis (OA) with genu varum due to painful medial compartment OA which is not amenable to conservative measures.

AIM

To evaluate the outcomes of medial open-wedge HTO along with autologous bone grafting and buttress plate for the treatment of genu varum due to OA of the knee in a rural population of central India.

METHODS

A total of 65 knees in 56 patients with a mean age of 58.22 ± 5.63 years with genu varum due to intractable painful knee OA were treated with medial open-wedge HTO along with autologous bone grafting and buttress plate osteosynthesis from June 2015 to May 2018. The mean preoperative radiological angle of genu varum was 13.4°. Clinical outcomes were assessed by the range of movement, knee scores, pain scores, and functional scores. Radiographic studies were performed preoperatively and at regular intervals during the follow-up period.

RESULTS

All patients reported pain relief immediately after the osteotomy and during the long-term analysis covering between one to three years. The genu varum angle was overcorrected to approximately four degrees in all patients. There was a loss of reduction by approximately three degrees in all patients at around six weeks postoperatively. Preoperative knee movements were restored in all patients. No major perioperative complications were noted during surgery and postoperative follow-up and the clinical scores were significantly improved during the final analysis which revealed good pain relief.

CONCLUSION

Medial open-wedge HTO is a reliable, safe, practical, physiological, and feasible treatment for populations who are used to increased activity in their occupation and lifestyle and is associated with excellent short-term and long-term results for OA in genu varum knees.

The Influence of Preoperative Tibial Bone Marrow Edema on Outcomes After Medial Opening-Wedge High Tibial Osteotomy

BACKGROUND

The relationship between preoperative subchondral bone marrow edema (BME) in the osteoarthritic knee and pain has been established. However, little is known about the influence of preoperative BME on outcomes after medial opening-wedge high tibial osteotomy (MOHTO). The purpose of this study was to clarify the association between preoperative BME severity and clinical outcomes after MOHTO at intermediate follow-up.

METHODS

We reviewed the cases of 105 consecutive patients who underwent MOHTO for osteoarthritis of the knee with preoperative subchondral BME in the medial aspect of the tibia between January 2005 and December 2015. BME was evaluated using magnetic resonance imaging (MRI). The sizes of the BME lesions were determined on the basis of the maximum diameter and were classified as small (<1 cm), medium (<2 cm), large (<4 cm), or very large (diffuse; >4 cm). Associations between preoperative BME severity and postoperative outcomes at a mean follow-up of 6.2 years (range, 2.0 to 14.3 years) were evaluated according to a Spearman correlation matrix with each reviewer's grades. Functional outcomes were assessed using the Hospital for Special Surgery (HSS) score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Society Score (KSS), and Short Form-12 (SF-12) questionnaire. Survival rate and complications were also evaluated.

RESULTS

The degree of preoperative BME was not significantly correlated with postoperative outcomes (p > 0.05). There were significant improvements between the preoperative and latest follow-up assessments in all functional outcome categories (p < 0.001). Patients demonstrated marked improvements with respect to pain, function, and quality of life. The overall survival rate was 95.2%, with a mean follow-up of 6.2 years. Six major complications were identified in 5.7% of the patients, and these resulted in 5 patients (4.8%) who had conversion to total knee arthroplasty.

CONCLUSIONS

We did not find any correlation between preoperative subchondral BME severity and postoperative outcomes. MOHTO showed good functional outcomes, a low major complication rate, and an excellent survival rate with a mean follow-up of 6.2 years, regardless of the degree of preoperative BME.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Osteotomies for the Management of Medial Compartment Defects of the Knee

For nearly three-quarters of a century the proximal tibia osteotomy has been used as an effective treatment for cartilage injuries of the knee. Over this same timeframe several advancements have been made in our diagnostic, preoperative planning, and technical execution of this procedure. As such, good-to-excellent short-, mid-, and long-term outcomes have been reported. Since its inception, the most important step in deciding on this procedure is identifying the ideal candidate. This candidate should be a young patient (<55 years old), active, with isolated medial compartment arthrosis without significant comorbidities. With appropriate patient selection and careful preoperative planning, the patient should achieve excellent results and high satisfaction.

Factors Associated With Patient Satisfaction After Opening-Wedge High Tibial Osteotomy

Background:

Opening-wedge high tibial osteotomy (OWHTO) is expected to result in higher patient satisfaction compared with knee arthroplasty due to joint preservation. However, patient satisfaction rates as well as factors associated with satisfaction after OWHTO remain unclear.

Purpose:

To evaluate patient subjective satisfaction after OWHTO and determine factors associated with patient satisfaction after OWHTO.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

This study enrolled 123 patients (123 knees) who underwent unilateral OWHTO. Clinical parameters, including range of motion (ROM), visual analog scale (VAS) score for pain, Knee injury and Osteoarthritis Outcome Score (KOOS), weightbearing line ratio (WBLR), and medial proximal tibial angle (MPTA), were assessed before surgery and at the final follow-up at a minimum of 2 years. Patient satisfaction was evaluated using a 5-point scale regarding (1) surgery, (2) pain relief, (3) knee mobility, (4) daily living function, and (5) lower extremity alignment. The mean overall satisfaction scores for the 5 questions were calculated, and the sample was divided into 2 main groups (satisfied or unsatisfied). Preoperative characteristics, physical activity level, patient expectations for surgery, ROM, and KOOS were compared between the groups. Cartilage regeneration was assessed at the time of plate removal, and WBLR and MPTA were also assessed. Factors associated with patient satisfaction were analyzed using multivariable logistic regression analysis.

Results:

The mean ± SD follow-up was 54.6 ± 20.6 months. The mean WBLR significantly changed from 20.7% ± 11.8% preoperatively to 66.9% ± 10.2% at the final follow-up, and all KOOS subscale scores significantly improved after surgery. Of the 123 patients, 109 (88.6%) were graded as satisfied. Factors associated with patient satisfaction were expectations met (odds ratio, 17.4; P = .026), better postoperative KOOS Pain score (odds ratio, 1.30; P = .001), and better postoperative KOOS Activities of Daily Living score (odds ratio, 1.36; P = .002).

Conclusion:

OWHTO is an effective treatment in terms of subjective satisfactory outcomes. Patient expectations for surgery have a significant effect on patient satisfaction. Surgeons should consider patient expectations before OWHTO and provide patient education to improve patient satisfaction.

A radiological study of bone remodeling with two different types of porous β-tricalcium phosphate in humans

In this study we compared the bone remodeling of unidirectional (UDPTCP) and spherical porous β-tricalcium phosphate (SPTCP) radiologically in humans. We performed a retrospective analysis of the data of 14 patients (sex, nine men and five women; age, 37–70 years) who underwent medial opening-wedge high tibial osteotomy (MOWHTO) and were followed up for 12 months after surgery. Two wedge-shaped β-TCPs (one UDPTCP and one SPTCP) were cut and placed parallel to each other in the gap. In Group A (eight knees), UDPTCP was implanted anteriorly and SPTCP posteriorly, while in Group B (six knees), SPTCP was implanted anteriorly and UDPTCP posteriorly. Computed tomography (CT) was performed at 1 week, 6 months, and 12 months after surgery, with the CT attenuation values calculated for UDPTCP and SPTCP. In Groups A and B, the CT attenuation values for UDPTCP were significantly lower at 6 and 12 months after surgery compared to those at 1 week (P < 0.05); nevertheless, no statistical difference in the comparison with SPTCP was observed. After a short-term follow-up of 12 months following MOWHTO, UDPTCP provided earlier bone remodeling than SPTCP. This outcome was achieved regardless of the position, anterior or posterior, in the MOWHTO gap.

Treatment of aseptic nonunion after medial opening-wedge high tibial osteotomy

BACKGROUND

Nonunion after medial opening-wedge high tibial osteotomy (OWHTO) is a rare but serious complication with very limited data regarding its treatment. The aim of this study was to analyze the healing rate after operative treatment of nonunion after OWHTO.

METHODS

We performed a single-center, retrospective study that included 14 patients with nonunion after OWHTO between 2010 and 2018. The treatment for all patients consisted of local debridement and cancellous bone grafting at the osteotomy gap. Revision osteosynthesis due to a loss of correction/loosening of the locking screws or plates was performed in 5 patients. In 7 patients, lateral hinge fractures were treated with additional lateral plating. Union was confirmed using the modified "Radiographic Union Score for Tibial fractures". Outcome measure was the Lysholm Knee Score at final follow-up.

RESULTS

The mean age of the patients included in our study was 48.4 ± 6.7 years. Three patients were female (21.4%). The mean follow-up period was 20.8 ± 12.8 months. Union was achieved in 12/14 patients (85.7%) after a mean of 6 months (range, 3-13). The mean Lysholm Knee Score at the final follow-up was 83.2 ± 11.6. Two patients did not reach definitive union during the follow-up. In one patient, an infection of the nonunion following bone grafting was successfully treated with a two-stage procedure. Two patients needed additional cancellous bone grafting 6 and 8 months after the first revision surgery. All patients showed pain-free full weight bearing after union was achieved.

CONCLUSIONS

Nonunions after OWHTO can generally be treated successfully with cancellous bone grafting. For patients who have loss of correction, loosening of the osteosynthetic material or fracture of the lateral hinge, an additional revision or additive osteosynthesis may be required.

LEVEL OF EVIDENCE

Grade III.

High tibial osteotomy performed with PEEK implant demonstrated a failure rate of 28

OBJECTIVES

Opening-wedge high tibia osteotomies (HTO) can be technically challenging. The HTO iBalance system was designed to reduce vascular complications and to avoid secondary plate removal. The purpose of the study was to evaluate the performance of the HTO iBalance system in patients with symptomatic medial osteoarthritis and varus malalignment.

METHODS

The study was performed as a retrospective cohort study investigating a consecutive series of patients who underwent HTO with the iBalance system performed by a single surgeon from August 2013 to March 2016 at Zealand University Hospital, Koege, and Aleris-Hamlet Hospital. The primary outcome was the degree of realignment. The secondary outcome was Knee injury and Osteoarthritis Outcome Score (KOOS). Follow-up was performed at mean (SD) 25 (9.7) months. Weight-bearing long-leg standing radiographs were taken before surgery and at follow-up. Failure was defined as collapse of the HTO defined as a correction <50% of the intended correction at time of follow-up. Logistic regression was used to identify risk factors for failure.

RESULTS

44 patients and a total of 47 knees were included in this study. Preoperatively the mechanical axis was a mean (SD) 5.8° (2.9) varus and postoperatively 2.3° (3.7) varus . The HTO failed in 13 of 47 knees (28%). Patients with failure showed no statistically significant differences to non-failure in any KOOS subscore (p>0.05). American Society of Anesthesiologists (ASA) score (p=0.01) and body mass index (BMI) (p=0.05) were correlated with failure, whereas bone transplantation and smoking were not.

CONCLUSION

In this study, the failure rate of HTO was 28%. High BMI and ASA-score were the only risk factors associated with failure while bone grafting and smoking were not.

LEVEL OF EVIDENCE

Retrospective cohort study, level III.

Relationship between the bony correction angle and mechanical axis change and their differences between closed and open wedge high tibial osteotomy

BACKGROUND

The purpose of this study was to investigate the relationship between the bony correction angle and mechanical axis change and their differences between closed wedge high tibial osteotomy (CWHTO) and open wedge high tibial osteotomy (OWHTO).

METHODS

A total of 100 knees of 89 patients who underwent OWHTO (50 knees) or CWHTO (50 knees) between 2011 and 2015 with a clinical follow-up for 1 year and a radiological follow-up for 1 month were investigated in a case control study. Anteroposterior radiographs of the knee and full-length leg were taken in the standing position using digital acquisition. The femorotibial angle (FTA), % mechanical axis deviation (MAD), % anatomical tibial axis deviation (ATAD), % mechanical tibial axis deviation (MTAD), mechanical medial proximal tibial angle (mMPTA), and joint line convergence angle (JLCA) were measured on preoperative and postoperative radiographs using a dedicated software.

RESULTS

CWHTO resulted in a greater variation between the tibial anatomical and mechanical axes than OWHTO (P <  0.05), and a greater soft tissue correction than OWHTO (P <  0.05). However, no significant difference was found between CWHTO and OWHTO in the ratio of MAD change to the correction angle. When the osteotomy was planned with the same bony correction angle, %MAD passed more laterally in OWHTO than in CWHTO (P <  0.05). These results suggested a lesser valgus bony correction ratio due to greater medial shift of the tibial axis and greater valgus compensation of the soft tissue in CWHTO compared to OWHTO.

CONCLUSIONS

The ratio of mechanical axis shift to the correction angle differed in preoperative planning, but postoperative alignment was comparable between opening wedge and closed wedge high tibial osteotomy.

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.

Changes in lower limb alignment and their effect on the functional outcome after treatment of varus degenerative OA knee by hemicallotasis using modular dynamic HTO fixator

OBJECTIVE

High tibial osteotomy (HTO) is an established procedure to treat medial compartmental osteoarthritis (OA) knee associated with varus deformity. It is well documented that precise correction of deformity and maintenance of correction achieved is important to ensure long term good results. This study was undertaken to record changes in radiological parameters and its effect on the functional outcomes in first two years following HTO done for varus degenerative OA kneeby hemicallotasis technique using HTO fixator.

METHODS

31 patients meeting our inclusion-exclusion criteria who underwent HTO by hemicallotasis method using self-adjusting unilateral HTO fixator were included in the study. Their femoro tibial angle (FTA), mechanical axis %, Insall- Salvati ratio, proximal tibial antero-posterior slope and knee injury and osteoarthritis outcome Score (KOOS) were recorded preoperatively, postoperatively at the time of removal of fixator, at 1 year and at 2 years.

RESULTS

The FTA and mechanical axis significantly improved from a mean of 183.12⁰ and -3.26% respectively preoperatively to 173.38⁰ and 61.81% at the time of removal of fixator but subsequently showed significant deterioration to 176.06⁰ and 57.96% at 1 year and further insignificant deterioration to 176.16⁰ and 57.74 at 2 years. The KOOS improved from mean 56.61 preoperatively to 70.48 at the time of fixator removal and further improved significantly to 85.68 at 1 year but significantly deteriorated to 84.54 at 2 years. The Insall-Salvati ratio, tibial slope showed no significant change throughout the study. Conclusion: Though desired alignment can be achieved by using the fixator, we found a significant deterioration in achieved radiological parameters after removal of fixator adversely affecting the functional outcome which is a matter of concern.

The Ability to Achieve a Specific Target Angle on Weightbearing Radiographs After Valgus High Tibial Osteotomy for Medial Knee Arthritis Is Not Predictable

Purpose

Standing radiographs are commonly used to plan angular correction in valgus tibial osteotomy for varus gonarthrosis. Most clinical studies have reported postoperative alignment as overall averages or means. The purpose of this study was to compare the preoperatively planned angle of correction measured on weight-bearing radiographs to the follow-up angle measured on weightbearing radiographs in individual patients 6 weeks after surgery and to analyze factors that could potentially affect achieving the planned degree of surgical correction. Our objective was to analyze factors potentially affecting the accuracy and ability to achieve the preoperatively planned correction angle (the target angle) in the individual patient.

Methods

We studied 35 tibial osteotomies (13 Coventry closing wedge osteotomies and 22 Maquet barrel vault osteotomies) performed for varus gonarthrosis between 1981 and 2019 to determine how accurately the target angle, based on preoperative standing weight-bearing radiographs, was achieved according to the postoperative radiographs in each individual. We reviewed 35 knees in 34 patients who had complete pre- and postoperative radiographs for review.

Results

Overall, only 14 of 35 (40%) of the patients were corrected to within ± 2° of the planned target angle. Valgus tibial osteotomy based on preoperative weightbearing radiographs is unpredictable in its ability to achieve the target angle on postoperative weightbearing radiographs when using either the Coventry or the Maquet surgical technique. The tendency was to undercorrect with either of the techniques. Larger (greater than 10°) preoperative varus alignment did not make it more difficult to achieve the target angle. Male or female sex and body mass index had no effect on the ability to achieve the target angle.

Conclusions

Valgus tibial osteotomy planning based on preoperative weightbearing is unpredictable in its ability to achieve the target angle on postoperative weightbearing radiographs. Overall, only 40% of our patients were corrected to within ± 2° of the planned target angle. The tendency was to undercorrect, with either the Coventry or the Maquet technique. Contrary to our hypothesis, larger preoperative varus alignment (greater than 10°) did not make it more difficult to achieve the target angle. The Coventry technique was as accurate as the Maquet technique.

Level of Evidence

Level IV.

Complications, Additional Surgery, and Joint Survival Analysis After Medial Open-Wedge High Tibial Osteotomy

The reported incidence of complications following medial open-wedge high tibial osteotomy (MOWHTO) varies. The authors sought to assess the complications, additional surgeries, and joint survival following MOWHTO in patients with isolated medial compartment arthrosis during a mean follow-up of 10 years. This retrospective study involved patients implanted with spacer plates, angle adjustable plates, or inverse L-type plates with wedges between 2000 and 2010. A total of 504 knees from 441 patients were examined. Mean age of the study population was 52.6±7.0 years, with 56 (11.1%) knees from men and 448 (88.9%) from women. The 10-year Kaplan-Meier joint survival rate was 94.8%. Overall complication rate for MOWHTO was 63.7%, with complications in 20.3% of treated knees requiring additional surgery. In this population, although the overall complication rate and the need for additional surgery were high, the need for additional surgery resulting from serious complications was low (2.6%). The high joint survival rate and low rate of additional surgery for serious complications indicate that MOWHTO can be safely applied in patients with isolated medial gonarthrosis. [Orthopedics. 2020;43(5):303-314.].

Ultrasonographic evaluation of the patellar tendon length and elasticity after open-wedge high tibial osteotomy: A comparison with radiological and clinical parameters

BACKGROUND

The aim of this study was to evaluate the length and elasticity of the patellar tendon after open-wedge high tibial osteotomy (OWHTO).

METHODS

This case-controlled, analytical study included patients who underwent unilateral OWHTO operation and a control group. The length, thickness, strain elastography, and strain ratio of the patellar tendon were measured. The outcome measures were the Insall-Salvati Index (ISI), Blackburne-Peel Index (BPI), Caton Index (CI), the International Knee Documentation Committee Score (IKDC), Oxford Knee Score (OKS) and Knee Injury and Osteoarthritis Outcome Score (KOOS), Ahlbäck classification, and mechanical axis. Elasticity of the patellar tendon obtained by strain elastography were graded as follows; hardest or hard tissue, intermediate tissue, and soft tissue.

RESULTS

The patellar tendon length was significantly shorter and patellar tendon thickness was significantly greater on the operated side compared with the values of the non-operated side and the control group (P<0.001 for all). Intermediate tissue was the most common elasticity grade (77%) for strain elastography on the operated side. Hardest tissue was the most common elasticity grade on the non-operated side of the patients (49.1%) and of the control group (70.0%). Patellar tendon length was correlated positively with IKDC, OKS, and KOOS values and patellar tendon thickness and strain ratio were correlated negatively with IKDC, OKS, and KOOS values.

CONCLUSION

The patellar tendon seems to be shortened and thickened, with reduced stiffness after OWHTO. The ultrasound parameters are also associated with functional outcomes.

Five years of clinical and radiological results with biplanar tibial open-wedge osteotomy: feasible option to prevent patella infera?

INTRODUCTION

High tibial osteotomy (HTO) was a treatment option for relatively young active patients with isolated medial compartment arthritis of the knee. This report showed clinical and radiological results of a new HTO technique, that uses a particular open-wedge high tibial osteotomy by incorporating the tibial tubercle into osteotomy line (TT-OWHTO) to preserve patella height.

MATERIALS AND METHODS

Preoperative and postoperative function was recorded on the IKDC score, Kujala PF score, EQ-VAS and Tegner activity scale. Radiological patella height was measured with Insall-Salvati index. All this clinical and radiological recorded data on 45 active patients, with an average age of 40.2 years who underwent this procedure, allowed to do a retrospective analysis.

RESULTS

All the patients reported improvement in symptoms with an average preoperative IKDC score from preoperative value 49.7-92.3 at last follow-up. Kujala PF score improves from 67.2 preoperative value to 91.4. EQ-VAS self-assessment of quality of life reported a preoperative value of 41.2-92.2 at last follow-up. There was 2.5 point average improvement in Tegner activity scale. Patella height was not altered with median preoperative value of 0.84 ± 0.1 and final follow-up value of 0.81 ± 0.2 on Insall-Salvati index.

CONCLUSIONS

TT-OWHTO showed to be able to achieve good clinical and radiological results maintaining patella height unchanged and ensuring safety and reproducibility as much as the traditional technique.

Coronal Alignment Correction and Maintenance of Tibial Slope in Opening-Wedge Valgus High Tibial Osteotomy Using a 4-Reference Kirschner Wire Technique: A Cadaveric Study

Background

Opening-wedge valgus high tibial osteotomy (OWHTO) is a common surgical procedure used to treat symptomatic varus femorotibial malalignment in adults. Several intraoperative methods are available to determine the correct correction alignment, but achieving the desired alignment correction is difficult.

Purpose/Hypothesis

The aim of this study was to assess a 4-reference K-wire technique that is relatively easy to apply and can reliably assess actual alignment correction during surgery after determination of the desired corrective angle. We hypothesized that this technique would accurately determine the coronal correction and properly maintain the tibial slope intraoperatively during OWHTO.

Study Design

Descriptive laboratory study.

Methods

This study was conducted using 12 fresh-frozen cadavers; 12 randomly chosen knees were corrected 5° and 12 knees were corrected 10° by use of 2 coronal and 2 sagittal K-wires. The first and second coronal K-wires were drilled at 4 cm and 1 to 2 cm below the medial joint line toward the tibiofibular joint, respectively. The angles of these 2 coronal K-wires were measured before and after the gap was opened via a modified goniometer. The difference in the angle formed by these 2 coronal K-wires from before to after opening of the gap was the alignment correction angle. In addition, 2 sagittal K-wires were drilled parallel to each other before the gap opening above and below the osteotomy site. Ensuring that these 2 sagittal K-wires remained parallel after the gap opening confirmed that the tibial slope had been maintained. The paired t test was used to compare the desired alignment corrections and the different angles measured between the pre- and postoperative radiographic alignments.

Results

The mean ± SD differences in angles between the pre- and postoperative alignments of the 5° and 10° corrections were 5.04° ± 0.68° and 10.03° ± 0.68°, respectively, indicating no statistically significant differences between pre- and postoperative alignment in both groups. As well, no significant difference was noted between the pre- and postoperative medial tibial slope (P = .54).

Conclusion

The coronal alignment correction and maintenance of the tibial slope using the 4-reference K-wire technique was found to be highly accurate and reliable.

Clinical Relevance

Achieving the correct angle in OWHTO is difficult, and the 4-reference K-wire technique provides an easier and more reliable way to obtain the correct angle. This technique can be used in most hospital settings, with no need for expensive equipment.

Medial opening wedge high tibial osteotomy: more than ten years of experience with Puddu plate technique supports its indication

PURPOSE

To describe the short-term and long-term results of patients who underwent a medial opening wedge high tibial osteotomy (MOW-HTO) for unicompartmental medial knee joint osteoarthritis.

METHODS

A retrospective review was conducted of patients with MOW-HTO using a Puddu plate®, with more than ten year follow-up. The degree of correction, initial chondral damage, number of meniscal lesions, preoperative and 1-year postoperative functional scale scores (IKDC and Lysholm), and arthroplasty conversion rates at the ten year follow-up were registered. We assumed early indication when patients underwent the operation before they were 40 years old and delayed ≥ 40. Functional outcomes were analyzed by adjusting for pre-operative values. Fisher's exact test was used to study the association between the arthroplasty conversion rates and the timing of indication.

RESULTS

Fifty-five patients were included, 37 of whom were male (67%). Twenty-nine patients had early indications for surgery (53%). All patients completed ten year follow-up. All patients improved IKDC (p < 0.01) and Lysholm (p < 0.01) scores compared to their presurgical scores at the one year post-operative evaluation. We had six minor complications, none requiring revision surgery. We had three conversions to arthroplasty, all in the late indication group, not statistically significant different. Linear regression showed that early indication was associated with a higher IKDC score when adjusting for the Outerbridge chondral damage score, the number of meniscal lesions, and sex (p < 0.01).

CONCLUSION

All patients improved functional scores one year after surgery. Early indication (i.e., younger than 40 years of age) was independently associated with better functional outcomes than late indication at one year follow-up.

Comparison of the outcomes between two different target points after open wedge high tibial osteotomy: The Fujisawa point versus the lateral tibial spine

BACKGROUND

The purpose of this study was to compare the clinical, radiographic and arthroscopic outcomes after open wedge high tibial osteotomy (OWHTO) aiming either at the Fujisawa point (group F) or the lateral tibial spine (LTS, group L).

METHODS

Between January 2011 and May 2017, 89 cases underwent implant removal procedures with second-look arthroscopy at 19.8 months after OWHTO with first-look arthroscopy. Among them, 24 and 65 cases were enrolled in groups F and L, respectively. Outcomes included clinical (evaluated using the Western Ontario and McMaster Universities Osteoarthritis index and the International Knee Documentation Committee subjective score), radiographic (observation of the mechanical axis (MA) and tibial slope), and arthroscopic (including chondral lesions of the medial femoral condyle (MFC), trochlea, and patella scored according to the International Cartilage Repair Society grading) measures, investigated at index surgery and implant removal surgery. Outcomes were compared between two groups.

RESULTS

Preoperative clinical characteristics and postoperative outcomes were similar between both groups. The mean postoperative MA was significantly lower in group F compared with group L (-3.9° vs. -1.6°, respectively; P < 0.001). Similar MFC cartilage grading changes from index surgery to second look surgery were shown; however, further progression of patellofemoral grading was shown in group F.

CONCLUSIONS

OWHTO aimed at the LTS has similar clinical outcomes to Fujisawa point. Surgery aimed at the LTS was slightly less corrected. Targeting the LTS could be an option after consideration of joint geometry and patellofemoral joint problems.

High tibial osteotomy in a lax knee: A review of current concepts

The technique of high tibial osteotomy (HTO) was traditionally documented for symptomatic medial tibiofemoral arthrosis associated with coronal plane malalignment in a stable knee., recently, more attention has been given to the treatment of coronal malalignment in lax knees with HTO with or without ligament reconstruction. Patients with overwhelming pain, chronic ligament deficiency and coronal or sagittal deformity are generally easier to treat with HTO as compared to those who have mild pain and a proximal tibial deformity. The instability at the knee joint can be either in the coronal or sagittal plane or in both planes. Younger patients with chronic ACL deficiency, varus malalignment and advanced medial compartment arthritis, who present with pain and slight instability show satisfactory results with HTO. Double-limb weight bearing anteroposterior view radiographs are used to plot mechanical leg axis (from the centre of the femoral head to the centre of the knee), anatomical axis (a line from the centre of the piriformis fossa to the centre of the knee joint and a line through the long axis of tibia) and weight bearing axis (line drawn from the centre of the femoral head to the centre of the ankle joint) and are used to plan HTO. A 3-dimensional pre-operative plan using CT and MRI is recently studied. The decision to perform HTO alone or in combination with ligament reconstruction involves consideration of patient demographics, symptoms and ligaments involved. The most commonly used surgical techniques for high tibial osteotomy include lateral close wedge osteotomy, medial open wedge osteotomy and dome osteotomy. The post-operative rehabilitation depends on the rigidity of fixation.

Difference in joint line convergence angle between the supine and standing positions is the most important predictive factor of coronal correction error after medial opening wedge high tibial osteotomy

PURPOSE

Coronal correction errors after medial opening wedge high tibial osteotomy (MOWHTO) occasionally occur even with the assistance of navigation. The purpose of the present study was to determine the navigation accuracy in MOWHTO and to identify factors that affect the coronal correction error after navigation-assisted MOWHTO.

METHODS

A total of 114 knees treated with navigation-assisted MOWHTO were reviewed retrospectively. Mechanical axis (MA) on standing radiograph and medial proximal tibial angle (MPTA) were measured preoperatively and at 6 months postoperatively, and the differences (ΔMA and ΔMPTA) were calculated. Joint line convergence angle (JLCA) on supine and standing radiographs was measured preoperatively, and their difference (ΔJLCA) was calculated. To assess the navigation accuracy, ΔMA and ΔMPTA were compared with the coronal correction by navigation (ΔNMA) using intraclass correlation coefficients (ICCs). Univariable and multivariable regression analyses were used to identify factors that affect coronal correction discrepancy (ΔMA - ΔNMA).

RESULTS

The reliability of navigation was good in terms of bony correction (ICC between ΔNMA and ΔMPTA, 0.844) and fair in terms of MA correction (ICC between ΔNMA and ΔMA, 0.706). The mean coronal correction discrepancy was 2.0° ± 2.4°. In the multivariable analysis, ΔJLCA was shown to be a predictive factor of coronal correction discrepancy (unstandardized coefficient, 1.026; R², 0.470).

CONCLUSION

Navigation in MOWHTO provided reliable information about bony correction; however, MA tended to be overcorrected. The difference in JLCA between the supine and standing radiographs was the most important preoperative factor that predicted the coronal correction discrepancy after MOWHTO. In patients with larger ΔJLCA, each degree of ΔJLCA should be subtracted from the planned amount of correction angle when preoperative planning is performed using standing radiographs.

LEVEL OF EVIDENCE

IV.

Open Versus Closing Wedge Osteotomy and Application to Mandibular Reconstruction

PURPOSE

To review the specific techniques of closing wedge osteotomy and open osteotomy, compare their clinical and radiographic outcomes, and apply these findings to mandibular reconstruction.

METHODS

A thorough review of the otolaryngology, facial plastic and reconstructive surgery, oral and maxillofacial surgery, and orthopedic surgery literature was conducted in the Ovid MEDLINE, EMBASE, and Google Scholar databases using the terms 'osteotomy' and 'mandibular reconstruction.'

RESULTS

Traditionally, open osteotomies were thought to result in greater rates of malunion. However, multiple meta-analyses within the orthopedic literature have refuted this. Closing wedge osteotomies, on the other hand, may increase the chance of damaging a perforator. Again, no studies have evaluated the relationship between type of osteotomy and flap survival or wound healing. The particular type of osteotomy performed often depends on the type of osseous flap being utilized.

CONCLUSIONS

Open osteotomies are a viable and even preferred alternative, particularly in flaps without consistent perforators, such as scapular free flaps.

Biomechanical and Functional Improvements Gained by Proximal Tibia Osteotomy Correction of Genu Varum in Patients with Knee Pain

BACKGROUND

Mechanical axis malalignment contributes to abnormal forces across the knee joint. Genu varum, or increased medial mechanical axis deviation (MAD), increases force transmission and contact pressures to the medial compartment. With increasing MAD and femoral-tibial mechanical axis angle (MAA), contact forces within the medial or lateral compartment of the knee significantly increase with increasing deformity. This may lead to knee pain, further deformity, and medial compartment degenerative joint disease, which can interfere with participation in sports and diminish quality of life.

PURPOSES/QUESTIONS

We sought to evaluate patients with knee pain with bilateral genu varum and determine the effect of bilateral proximal tibial osteotomies on knee biomechanics, deformity correction, and functional outcomes.

METHODS

This was a single-center, prospective study of eight limbs in four patients. Consecutive patients presenting with knee pain and bilateral genu varum originating from the proximal tibia were included. All patients underwent staged bilateral proximal tibial osteotomies with gradual deformity correction with an external fixator. Subjects underwent a three-dimensional (3D) instrumented motion analysis during level walking. A 3D lower extremity model was built and bilateral knee frontal plane kinematics and kinetics during the stance phase of gait were determined. Radiographic analysis was performed including assessment of MAD, MAA, and medial proximal tibial angle (MPTA). Functional outcomes were assessed with the Knee Injury and Osteoarthritis Outcome Score (KOOS), the 36-item Short-Form Survey (SF-36), the Lower Limb Questionnaire (LLQ), and a visual analog scale (VAS) for pain.

RESULTS

The average time in the external fixator for a single limb was 97 days. The average follow-up period was 310 days. All biomechanical outcomes significantly improved, including knee adduction angle (7.8° to 1.8°), knee adduction moments (first peak, - 0.450 to - 0.281 nm/kg, and second peak, - 0.381 to - 0.244 nm/kg), and knee adduction moment impulse (- 0.233 to - 0.150 nm s/kg). There was a significant improvement in MAA, MAD, and MPTA. All patients showed qualitative improvement in mean scores on VAS (11.8 to 0.0), LLQ (77 to 93), KOOS (64 to 84), and SF-36 (71 to 88).

CONCLUSION

These findings suggest that bilateral proximal tibial osteotomy may be effective in improving knee biomechanics during gait and correcting mechanical alignment in patients with bilateral genu varum. Patients also demonstrated improvement in functional outcome scores. This technique should thus be considered in patients with varus knee osteoarthritis in the setting of genu varum to alleviate symptoms and potentially decrease further clinical deterioration.

The actual knee function was not influenced by joint line obliquity after open-wedge high tibial osteotomy

Purpose: Excessive joint line obliquity (JLO) after open-wedge high tibial osteotomy (OWHTO) induces detrimental stress on the articular cartilage. The purpose of this article is to assess the correlation between JLO and the clinical results after OWHTO.

Methods: 68 patients were followed up for more than 1 year. JLO was assessed using a long-leg standing anteroposterior radiograph. The knee osteoarthritis outcome score (KOOS) and KSS (Knee Society score) objective knee score were assessed as clinical scores. The Weight-bearing line ratio (WBLR), medial proximal tibial angle (MPTA), lateral distal femoral angle (LDFA), and joint line convergence angle (JLCA) were assessed as radiological parameters. The timed up-and-go (TUG) test and single-leg standing (SLS) test were performed, and the isometric muscle strength of the quadriceps and hamstrings was assessed to evaluate the knee function. The primary outcomes were the correlations between the JLO and the clinical score, radiological parameters and knee function after OWHTO. The secondary objective of this study was to detect the factor with the greatest influence on JLO.

Results: There were significant correlations between the postoperative JLO and the KOOS in the subcategories of pain, activities of daily living (ADL), and sports and recreation (r = −0.311, −0.302, −0.282, p = 0.011, 0.014, 0.022, respectively). However, the postoperative JLO was not significantly correlated with the KSS, knee function, or muscle strength. The preoperative LDFA and postoperative MPTA were factors influencing increased JLO after OWHTO.

Discussion: There was no significant correlation between the JLO and the actual knee function. The preoperative LDFA and postoperative MPTA were factors that influenced the increase in JLO after OWHTO.

A meta-analysis of total knee arthroplasty following high tibial osteotomy versus primary total knee arthroplasty

BACKGROUND

This study was performed to compare the clinical and radiographic outcomes of total knee arthroplasty (TKA) following high tibial osteotomy (HTO) versus primary TKA.

METHODS

Relevant trials were identified via a search of Ovid, PubMed and the Cochrane Central Register of Controlled Trials from inception to 10 January 2019. A meta-analysis was performed to compare postoperative outcomes between revising HTO to TKA (RHTO) and primary TKA (PTKA) with respect to Knee Society Score (KSS), 10-year survival rate, operative time, flexion and extension angle, infection rate and radiographic results.

RESULTS

Sixteen of 340 studies involving 103,552 adult patients (RHTO group, n = 3955; PTKA group, n = 99,597) were eligible for inclusion in the meta-analysis. Compared with primary TKA, revising HTO to TKA required longer operative time and had a higher infection rate (P < 0.05). The PTKA group had better flexion angle than the RHTO group (P < 0.05). There were no significant differences between the two groups in the KSS, extension angle, radiographic results and 10-year survival rate (P > 0.05).

CONCLUSION

Patients who undergo conversion of HTO to TKA have similar 10-year survival rate, KSS, extension angle and radiographic results as patients who undergo primary TKA. However, conversion of HTO to TKA required longer operative time and had a higher infection rate than performing primary TKA. Moreover, conversion of HTO to TKA is associated with poorer flexion angle than primary TKA.

Lateral hinge fracture delays healing of the osteotomy gap in opening wedge high tibial osteotomy with a beta-tricalcium phosphate block

BACKGROUND

The purpose of this study was to investigate the healing process of synthetic bone grafts in opening wedge high tibial osteotomy (OWHTO) and to identify the factors that affect bone healing in OWHTO. It was hypothesized that lateral hinge fracture (LHF) is associated with delayed bone healing after OWHTO with synthetic bone grafting.

METHODS

The subjects included 350 knees of 283 patients who underwent OWHTO using two wedged blocks of beta-tricalcium phosphate (β-TCP) with 60% porosity. The healing of the osteotomy gap using a radiologic rating system for OWHTO with synthetic bone grafts and the presence of an LHF were assessed up to postoperative 24 months.

RESULTS

LHFs were found in 49 knees (14%). The osteotomy gap showed slower progression of radiographic healing with an LHF than without an LHF (P < .05). In the knees with LHFs, initial radiographic change in the osteotomy gap was observed almost at the same time as healing of the LHF. Multivariate logistic regression analysis identified LHF as the factor preventing the progression of bone healing (OR = 46.78, P < .05).

CONCLUSIONS

LHF is associated with delayed bone healing after OWHTO with synthetic bone grafting.

The influence of computer-assisted surgery experience on the accuracy and precision of the postoperative mechanical axis during computer-assisted lateral closing-wedge high tibial osteotomy

Background

There is debate regarding the influence of a surgeon’s experience with computer-assisted surgery (CAS) on the postoperative mechanical axis (MA) in CAS-high tibial osteotomy. The purpose of the present study was to compare radiographic results between early and late cohorts of a consecutive series of patients to assess the influence of CAS experience on accuracy and precision of the postoperative MA during CAS lateral closing-wedge high tibial osteotomy (LCWHTO).

Materials and methods

Results from 140 CAS-LCWHTO operations were retrospectively reviewed. The first 70 cases, performed during the learning curve period for CAS between 2005 and 2009, were considered to be the “early cohort.” The subsequent 70 cases, performed with greater CAS experience after the completion of the learning curve between 2009 and 2014, were considered to be the “late cohort.” The target postoperative MA angle was valgus 3°. Pre- and postoperative MA angles were evaluated by navigation and radiographs. The proportion of postoperative MA inliers (≤ target angle ±3°) was investigated radiographically. The correlation between the navigation and radiographic measurements was analyzed.

Results

The average postosteotomy MA angle on navigation was 3.4° in both cohorts. The average postoperative MA angle on radiographs was 1.0° in the early cohort and 2.2° in the late cohort (P = 0.003). Radiographically, the proportion of postoperative MA inliers was greater in the late cohort than in the early cohort (early versus late, 71.4% versus 90%; P = 0.011). The pre- and postoperative correlation between navigation and radiographic measurements was also stronger in the late cohort (early versus late; preoperative r = 0.558 versus 0.663; postoperative r = 0.310 versus 0.376).

Conclusions

Greater experience with CAS increased the accuracy and precision of postoperative MA alignment as well as the correlation between navigation and radiographic measurements. Caution should be taken during registration procedures to achieve accurate alignment correction in CAS-LCWHTO.

Factors affecting stability after medial opening wedge high tibial osteotomy using locking plate: A cadaveric study

OBJECTIVES

To investigate the effect of screw length, lateral hinge fracture, and gap filling on stability after medial opening wedge high tibial osteotomy (MOW HTO) using a locking plate.

METHODS

Forty tibiae from fresh-frozen cadavers were randomly allocated into five groups. Group A was bicortically fixated, while Group B and Group C were unicortically fixated: 90% and 55% of drilled tunnel length, respectively. Group D was fixated using 90% length screws with a fractured lateral hinge. Group E was fixated using 90% length screws with gap filling using a bone substitute. Operated tibiae were tested under axial compressive load using a material testing machine. The medial gap changes under the serial axial load of 100-600 N and ultimate failure load were measured.

RESULTS

Group D showed the biggest medial gap change and lowest failure load, while Group E presented the smallest gap change and highest failure load. The medial gap changes tended to increase with shorter screw length, but the difference was not significant between Groups A, B, and C. Group C and Group D showed greater medial gap change and lower failure load compared with Group E, while not differing from Group A and Group B.

CONCLUSIONS

Unicortical fixation in proximal screw holes of a locking plate was not inferior to bicortical fixation regarding axial stability in MOW HTO, although proximal screws that are too short should be avoided. Lateral hinge fracture decreased, while gap filling with bone substitute increased axial stability.

Surgical interventions for symptomatic mild to moderate knee osteoarthritis

BACKGROUND

Osteoarthritis affecting the knee is common and represents a continuum of disease from early cartilage thinning to full-thickness cartilage loss, bony erosion, and deformity. Many studies do not stratify their results based on the severity of the disease at baseline or recruitment.

OBJECTIVES

To assess the benefits and harms of surgical intervention for the management of symptomatic mild to moderate knee osteoarthritis defined as knee pain and radiographic evidence of non-end stage osteoarthritis (Kellgren-Lawrence grade 1, 2, 3 or equivalent on MRI/arthroscopy). Outcomes of interest included pain, function, radiographic progression, quality of life, short-term serious adverse events, re-operation rates and withdrawals due to adverse events.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase up to May 2018. We also conducted searches of ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform for ongoing trials. Authors of trials were contacted if some but not all their participants appeared to fit our inclusion criteria.

SELECTION CRITERIA

We included randomised controlled trials that compared surgery to non-surgical interventions (including sham and placebo control groups, exercise or physiotherapy, and analgesic or other medication), injectable therapies, and trials that compared one type of surgical intervention to another surgical intervention in people with symptomatic mild to moderate knee osteoarthritis.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials and extracted data using standardised forms. We analysed the quality of evidence using the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach.

MAIN RESULTS

A total of five studies involving 566 participants were identified as eligible for this review. Single studies compared arthroscopic partial meniscectomy to physical therapy (320 participants), arthroscopic surgery (debridement ± synovectomy ± chondroplasty) to closed needle joint lavage with saline (32 participants) and high tibial osteotomy surgery to knee joint distraction surgery (62 participants). Two studies (152 participants) compared arthroscopic surgery (washout ± debridement; debridement) to a hyaluronic acid injection. Only one study was at low risk of selection bias, and due to the difficulty of blinding participants to their treatment, all studies were at risk of performance and detection bias.Reporting of results in this summary has been restricted to the primary comparison: surgical intervention versus non-surgical intervention.A single study, included 320 participants with symptoms consistent with meniscal tear. All subjects had the meniscal tear confirmed on knee MRI and radiographic evidence of mild to moderate osteoarthritis (osteophytes, cartilage defect or joint space narrowing). Patients with severe osteoarthritis (KL grade 4) were excluded. The study compared arthroscopic partial meniscectomy and physical therapy to physical therapy alone (a six-week individualised progressive home exercise program). This study was at low risk of selection bias and outcome reporting biases, but was susceptible to performance and detection biases. A high rate of cross-over (30.2%) occurred from the physical therapy group to the arthroscopic group.Low-quality evidence suggests there may be little difference in pain and function at 12 months follow-up in people who have arthroscopic partial meniscectomy and those who have physical therapy. Evidence was downgraded to low quality due to risk of bias and imprecision.Mean pain was 19.3 points on a 0 to 100 point KOOS pain scale with physical therapy at 12 months follow-up and was 0.2 points better with surgery (95% confidence interval (CI) 4.05 better to 3.65 points worse with surgery, an absolute improvement of 0.2% (95% CI 4% better to 4% worse) and relative improvement 0.4% (95% CI 9% better to 8% worse) (low quality evidence). Mean function was 14.5 on a 0 to 100 point KOOS function scale with physical therapy at 12 months follow-up and 0.8 points better with surgery (95% CI 4.3 better to 2.7 worse); 0.8% absolute improvement (95% CI 4% better to 3% worse) and 2.1% relative improvement (95% CI 11% better to 7% worse) (low quality evidence).Radiographic structural osteoarthritis progression and quality of life outcomes were not reported.Due to very low quality evidence, we are uncertain if surgery is associated with an increased risk of serious adverse events, incidence of total knee replacement or withdrawal rates. Evidence was downgraded twice due to very low event rates, and once for risk of bias.At 12 months, the surgery group had a total of three serious adverse events including fatal pulmonary embolism, myocardial infarction and hypoxaemia. The physical therapy alone group had two serious adverse events including sudden death and stroke (Peto OR 1.58, 95% CI 0.27 to 9.21); 1% more events with surgery (95% CI 2% less to 3% more) and 58% relative change (95% CI 73% less to 821% more). One participant in each group withdrew due to adverse events.Two of 164 participants (1.2%) in the physical therapy group and three of 156 in the surgery group underwent conversion to total knee replacement within 12 months (Peto OR 1.76, 95% CI 0.43 to 7.13); 1% more events with surgery (95% CI 2% less to 5% more); 76% relative change (95% CI 57% less to 613% more).

AUTHORS' CONCLUSIONS

The review found no placebo-or sham-controlled trials of surgery in participants with symptomatic mild to moderate knee osteoarthritis. There was low quality evidence that there may be no evidence of a difference between arthroscopic partial meniscectomy surgery and a home exercise program for the treatment of this condition. Similarly, low-quality evidence from a few small trials indicates there may not be any benefit of arthroscopic surgery over other non-surgical treatments including saline irrigation and hyaluronic acid injection, or one type of surgery over another. We are uncertain of the risk of adverse events or of progressing to total knee replacement due to very small event rates. Thus, there is uncertainty around the current evidence to support or oppose the use of surgery in mild to moderate knee osteoarthritis. As no benefit has been demonstrated from the low quality trials included in this review, it is possible that future higher quality trials for these surgical interventions may not contradict these results.

The Barrel Vault Tibial Osteotomy of Maquet for Medial Compartment Arthritis of the Knee

The barrel vault tibial osteotomy performed for knee varus osteoarthritis avoids the complications of the opening wedge osteotomy and minimizes the potential complications of the lateral closing wedge osteotomy. It allows correction of large varus deformities in knee medial compartment osteoarthritis.

Carbon-Fiber-Reinforced Polymer Intramedullary Nails Perform Poorly in Long-Bone Surgery

BACKGROUND

Carbon-fiber-reinforced (CFR) polymer has produced great excitement in the orthopedic community as a material that will reduce bone healing times and provide improved image quality. Osteotomy stabilized with an intramedullary (IM) nail has become a common technique to address post-traumatic malalignment of the lower extremity.

PURPOSES/QUESTIONS

The following questions were asked: (1) Did CFR polymer nails provide a rapid healing time after long bone osteotomy, shortening, or fracture? (2) Did the CFR polymer nails produce unexpected complications?

METHODS

A retrospective review was conducted in patients who received CFR polymer IM nails for various indications, from April 2016 to January 2017 in a deformity and trauma practice, using patient charts and radiographs. The primary outcomes were time to union and incidence of complications including nonunion, hardware failure, neurovascular injury, venous thromboembolism, and infection.

RESULTS

Twelve patients who received CFR polymer IM nails in 16 limbs for various indications were included in our analysis. Patients were followed for an average of 16.9 months. Eleven limbs underwent realignment and were corrected an average of 23° through a diaphyseal osteotomy. Three limbs underwent limb-shortening surgery, an average of 25 mm, through an open, excisional osteotomy of the femoral diaphysis. Two diaphyseal, closed tibia fractures underwent routine IM nailing. The average time to union was 107.6 days, which included all limbs that united (11/16, 69%). Nonunion occurred in 5/16 (31%) of limbs. Complications recorded included nonunion and hardware failure, most of which resulted in unplanned surgery.

CONCLUSIONS

The use of the CFR polymer IM nail was associated with loss of fixation and nonunion after surgeries that have traditionally healed uneventfully. The increased elasticity of the CFR polymer allows for more motion at the osteotomy/fracture interface than the stiffer titanium counterparts, exposing long-bone osteotomies to delayed union and nonunion, a finding seen with CFR polymer plates. The overwhelmingly poor early results of this device applied to a long-bone deformity practice have led these authors to abandon the use of this implant.

Distal femoral osteotomy in a young symptomatic population: Outcomes correlate to concomitant pathology

Background

There is a paucity of literature describing distal femoral osteotomies (DFO) in regards to complications and outcomes with previously studied cohorts containing primarily older, arthritic subjects. There has been no study to date focusing on younger, pre-arthritic patients.

Methods

All service members indicated for distal femoral osteotomy for coronal plane malalignment were isolated from military treatment centers between 2007 and 2013. Demographic and surgical variables were extracted, and perioperative complications, clinical course, and return to military function were extracted using clinical notes and radiographs.

Results

A total of 22 knees in 19 patients were identified at an average 3.2 year follow-up, with the exclusion of 16 individuals. Statistical analysis revealed worse outcomes associated with smoking, over correction, breach of the medial cortex, and prior surgeries. Overall 58% of patients left the military as the result of knee dysfunction despite an average improvement in visual analog scores (VAS) from 4.0 to 1.9 (p = 0.004).

Conclusions

While offloading the lateral compartment improves symptoms at short to midterm follow-up preventing progression to arthroplasty, young active duty military members have suboptimal return to duty rates.

Medial Opening-Wedge High Tibial Osteotomy for Medial Compartment Arthrosis/Overload

Medial opening-wedge high tibial osteotomy has become increasingly popular for treating isolated, medial compartment arthrosis in younger, more active patients. Relative indications include age younger than 55 to 60 years, normal weight, preserved range of motion, and isolated medial compartment osteoarthritis or overload. Several surgical techniques exist for stabilization of the osteotomy with similar outcomes. Complication rates after medial opening-wedge high tibial osteotomy vary from 29% to 37%, with highest risk of nonunion, fracture, stiffness, and loss of correction. Good long-term outcomes can be achieved, with 5- and 10-year survivorship rates ranging from 75% to 98.7% and 51% to 97.6%, respectively.

Improved Methods to Measure Outcomes After High Tibial Osteotomy

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

High Tibial Osteotomy: Review of Techniques and Biomechanics

High tibial osteotomy becomes increasingly important in the treatment of cartilage damage or osteoarthritis of the medial compartment with concurrent varus deformity. HTO produces a postoperative valgus limb alignment with shifting the load-bearing axis of the lower limb laterally. However, maximizing procedural success and postoperative knee function still possess many difficulties. The key to improve the postoperative satisfaction and long-term survival is the understanding of the vital biomechanics of HTO in essence. This review article discussed the alignment principles, surgical technique, and fixation plate of HTO as well as the postoperative gait, musculoskeletal dynamics, and contact mechanics of the knee joint. We aimed to highlight the recent findings and progresses on the biomechanics of HTO. The biomechanical studies on HTO are still insufficient in the areas of gait analysis, joint kinematics, and joint contact mechanics. Combining musculoskeletal dynamics modelling and finite element analysis will help comprehensively understand in vivo patient-specific biomechanics after HTO.

Risk of Revision Following Total Knee Arthroplasty or High Tibial Osteotomy: A Nationwide Propensity-Score-Matched Study

BACKGROUND

High tibial osteotomy (HTO) is often performed to postpone or avoid the need for subsequent total knee arthroplasty (TKA). We designed the present study to investigate the incidence rate and risk factors for subsequent revision in patients treated with HTO compared with those managed with TKA.

METHODS

In this retrospective nationwide cohort study, we reviewed the South Korean National Health Insurance claims database from January 1, 2009, to August 31, 2017. We evaluated patients ≥41 years old who had undergone TKA or HTO as the primary surgical procedure without a history of having undergone either procedure during the preceding 2 years. By including only new interventions without such prior surgery, we could eliminate the influence of previous TKA and HTO treatments. Multivariable logistic regression models were used to compare the risk of revision between the groups after propensity score matching with inverse probability of treatment weighting (IPTW). Revision was defined as conversion to revision TKA after primary TKA and conversion to TKA after HTO.

RESULTS

After applying the IPTW, a total of 436,538 patients with TKA and 452,724 patients with HTO were identified. The risk of revision during the entire study period was higher for patients with HTO than for patients with TKA (adjusted hazard ratio [HR], 2.47). The Kaplan-Meier 8-year survival was 97.8% in the TKA group and 91.5% in the HTO group. Compared with patients with TKA, patients with HTO had an increased risk of revision in cases of advanced age (HR of 1.85 for patients who were ≥61 to 69 years old and HR of 4.17 for those who were ≥70 years old), female sex (HR, 2.90), recipients of Medical Aid program benefits (HR, 4.77), the presence of hyperlipidemia (HR, 3.70), the presence of diabetes (HR, 4.86), and the presence of osteoporosis (HR, 3.53). However, younger patients with HTO (≤60 years old) had a lower risk of subsequent revision (HR, 0.64).

CONCLUSIONS

The risk of revision was higher for patients with HTO than for patients with TKA. The risk factors for subsequent revision in patients with HTO in our cohort of patients were advanced age (>60 years), female sex, receipt of Medical Aid, and the presence of comorbidities, such as diabetes, osteoporosis, and hyperlipidemia.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Deterioration of patellofemoral cartilage status after medial open-wedge high tibial osteotomy

PURPOSE

To identify parameters associated with deterioration of patellofemoral (PF) cartilage after open-wedge high tibial osteotomy (OWHTO) and determine predictive values. It was hypothesized that cartilage injuries in PF joints would progress after OWHTO in patients who need a large alignment correction.

METHODS

Fifty-two knees in 47 patients who underwent bi-planer OWHTO for the treatment of medial compartment osteoarthritis from 2012 to 2017 and received a second-look arthroscopy at the time of plate removal (mean 14 months post-OWHTO) were assessed. Clinical outcomes were evaluated by the Knee Society Scores. Cartilage status in PF joints were evaluated arthroscopically using the International Cartilage Repair Society (ICRS) grading system. Patients were divided into two groups and patients who had progressed PF cartilage injury (progressed group) were compared with those who did not have progressed PF cartilage injuries (non-progressed group) using various parameters. The relationships between medial opening gap or change in the medial proximal tibial angle (ΔmPTA) and progression of PF cartilage injuries were examined by receiver operating characteristic (ROC) curve analysis.

RESULTS

The mean Knee Society Scores were significantly improved after surgery (P < 0.01). The grades for the patella and trochlea progressed in 12 (23.0%) and 16 knees (30.8%), respectively. The mean preoperative hip-knee-ankle (HKA) angle, mechanical axis, and mPTA in the progressed group were significantly smaller than those in the non-progressed group (P < 0.01). The mean medial opening gap and ΔmPTA in the progressed group were significantly larger than those in the non-progressed group (P < 0.01). ROC curve analysis showed that the cut-off values of the medial opening gap and ΔmPTA for progression of PF cartilage injuries were 13 mm and 9°, respectively. Progression of PF cartilage injuries was more frequently observed in knees with a medial opening gap ≥ 13 mm (P = 0.019, odds ratio = 4.60) or a ΔmPTA ≥ 9° (P = 0.003, odds ratio 6.93) than knees with those of < 13 mm or 9°, respectively.

CONCLUSIONS

Cartilage injuries in PF joints tended to progress after OWHTO in patients with medial opening gap ≥ 13 mm or ΔmPTA ≥ 9°. If medial opening gap is ≥ 13 mm or ΔmPTA is ≥ 9° in planning for OWHTO, other type of surgery may need to be considered to avoid early progression of PF cartilage injuries.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Graft materials provide greater static strength to medial opening wedge high tibial osteotomy than when no graft is included

Background

The purpose of this study was to compare the stability of medial opening-wedge high tibial osteotomy (MOWHTO) with and without different graft materials. Good clinical and radiological outcomes have been demonstrated when either using or not using graft materials during MOWHTO. Variations in the biomechanical properties of different graft types, regarding the stability they provide a MOWHTO, have not been previously investigated.

Methods

A 10 mm biplanar MOWHTO was performed on 15 artificial sawbone tibiae, which were fixed using the Activmotion 2 plate. Five bones had OSferion60 wedges (synthetic group), five had allograft bone wedges (allograft group), and five had no wedges (control group) inserted into the osteotomy gap. Static compression was applied axially to each specimen until failure of the osteotomy. Ultimate load, horizontal and vertical displacements were measured and used to calculate construct stiffness and valgus malrotation of the tibial head.

Results

The synthetic group failed at 6.3 kN, followed by the allograft group (6 kN), and the control group (4.5 kN). The most valgus malrotation of the tibial head was observed in the allograft group (2.6°). The synthetic group showed the highest stiffness at the medial side of the tibial head (9.54 kN·mm^− 1), but the lowest stiffness at the lateral side (1.59 kN·mm^-1). The allograft group showed high stiffness on the medial side of the tibial head (7.54 kN·mm^− 1) as well as the highest stiffness on the lateral side (2.18 kN·mm^− 1).

Conclusions

The use of graft materials in MOWHTO results in superior material properties compared to the use of no graft. The static strength of MOWHTO is highest when synthetic grafts are inserted into the osteotomy gap. Allograft wedges provide higher mechanical strength to a MOWHTO than when no graft used. In comparison to the synthetic grafts, allograft wedges result in the stiffness of the osteotomy being more similar at the medial and lateral cortices.

Regenerative Medicine: A Review of the Evolution of Autologous Chondrocyte Implantation (ACI) Therapy

Articular cartilage is composed of chondrons within a territorial matrix surrounded by a highly organized extracellular matrix comprising collagen II fibrils, proteoglycans, glycosaminoglycans, and non-collagenous proteins. Damaged articular cartilage has a limited potential for healing and untreated defects often progress to osteoarthritis. High hopes have been pinned on regenerative medicine strategies to meet the challenge of preventing progress to late osteoarthritis. One such strategy, autologous chondrocyte implantation (ACI), was first reported in 1994 as a treatment for deep focal articular cartilage defects. ACI has since evolved to become a worldwide well-established surgical technique. For ACI, chondrocytes are harvested from the lesser weight bearing edge of the joint by arthroscopy, their numbers expanded in monolayer culture for at least four weeks, and then re-implanted in the damaged region under a natural or synthetic membrane via an open joint procedure. We consider the evolution of ACI to become an established cell therapy, its current limitations, and on-going strategies to improve its efficacy. The most promising developments involving cells and natural or synthetic biomaterials will be highlighted.

Short-term functional outcomes of computer assisted navigated high tibial osteotomy

Purpose

High tibial osteotomy (HTO) is a surgical procedure performed on patients with knee osteoarthritis (OA). Computer assisted navigated high tibial osteotomy (CAN-HTO) may result in improved outcomes for patients undergoing this procedure.

Methods

Retrospective study involving patients undergoing CAN-HTO.

Results

Surveyed thirty-three patients. Average follow-up: 2.3 years. 97% patients reported they would have this procedure performed again, if indicated. Re-operation rate: 6.1% and complication rate: 12.1%. Patients had decreased KOOS for symptoms when compared to non-navigation based HTO (p = 0.000).

Conclusion

There may be merit with the use of CAN-HTO, with demonstrated patient-reported benefits at 2-year follow-up.

Intraoperative computer-assisted prediction of intraarticular contact pressures in the knee during high tibial osteotomy

OBJECTIVES

To develop an accurate intraoperative method to estimate changes in intraarticular contact pressures during high tibial osteotomy (HTO).

METHODS

Changes in knee alignment and pressure were monitored in real time in seven cadaver specimens that received HTO. Intraarticular contact pressure (N/mm² ) in each knee compartment was estimated based on extraarticularly acquired data (leg alignment, correction, and ankle tilt) and based on the application of an axial force of half bodyweight (400-450 N).

RESULTS

Contact pressure estimation was more accurate in the lateral compartment (R²  = 0.940) than in the medial compartment of the knee (R²  = 0.835). The optimism-corrected R² was 0.936 for the lateral compartment and 0.821 for the medial compartment.

CONCLUSIONS

We have established a framework for estimating the change in intraarticular contact pressures based on extraarticular data. This research could be helpful in generating appropriate algorithms to estimate joint alignment changes based on applied loads.