Opening-wedge high tibial osteotomy without bone grafting in severe varus osteoarthritic knee. Rate and risk factors of non-union in 41 cases

Evaluating the Effectiveness of a Structural Allograft in Medial Open Wedge High Tibial Osteotomy in Patients With and Without a Lateral Hinge Fracture

Background

A lateral hinge fracture is a common complication in medial open wedge high tibial osteotomy (MOWHTO) and is associated with delayed union or nonunion. A comparison of outcomes between patients with or without a lateral hinge fracture after MOWHTO with a structural allograft has not been investigated.

Purpose

To validate the outcomes of MOWHTO with a structural allograft, especially in the presence of a lateral hinge fracture.

Study Design

Case series; Level of evidence, 4.

Methods

We conducted a single-surgeon cohort study at a tertiary referral hospital between April 2017 and August 2022 and included patients who had undergone MOWHTO with a structural allograft for isolated medial compartment osteoarthritis with genu varum. We compared the incidence of delayed union or nonunion events and functional scores between patients with a lateral hinge fracture and those without using the Fisher exact test and independent t test.

Results

A total of 88 MOWHTO procedures (77 patients) were analyzed. The overall incidence of lateral hinge fractures was 29.5% (n = 26), including type I (n = 20 [22.7%]) and type II (n = 6 [6.8%]). Notably, 42.3% (n = 11) of these fractures had not been detected intraoperatively but during the follow-up visits. The overall Knee Society Score (KSS), Knee Society Score-Function (KSS-F), and Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores were 90.0 ± 10.0, 93.4 ± 10.8, and 93.8 ± 7.1 points, respectively. None of the patients had delayed union or nonunion, and none underwent a reoperation because of bony union problems. The functional scores (KSS, KSS-F, and WOMAC) were not different between patients who had a lateral hinge fracture and those who did not (P > .05).

Conclusion

The routine use of a structural allograft was associated with satisfactory outcomes after MOWHTO, regardless of whether there was a lateral hinge fracture.

Medial opening wedge high tibial osteotomy performs similarly irrespective of body mass index

PURPOSE

This study investigates the effect of the body mass index (BMI) on the early (2 years) to midterm (5 years) results of medial opening wedge high tibial osteotomy (MOWHTO).

METHODS

A prospectively maintained single-centre database of 1138 knee osteotomies, between 2002 and 2022, was retrospectively reviewed. Adult patients who underwent MOWHTO for symptomatic unicompartmental medial knee osteoarthritis (OA), with varus knee malalignment, having failed conservative management, were included. Patients were categorized into three groups according to their BMI as per the classification from the National Institute for Health and Care Excellence (NICE): the healthy weight (HW) group (BMI of 18.5-24.9 kg/m2), the overweight (OW) (BMI of 25-29.9 kg/m2), and the obesity (OB) group (BMI ≥ 30 kg/m2). Multiple patient-reported outcome measures (n = 6) were recorded preoperatively and at 2 and 5 years postoperatively. Deformity analysis was undertaken preoperatively and postoperatively. The relative risk (RR) of the complications between the HW, OW and OB groups was calculated. The rate of conversion to arthroplasty, and 5 and 10 years survivorship were recorded, as well as the hazard ratio (HR) of BMI on survivorship.

RESULTS

A total of 574 cases were included in the study: the HW group (n = 96), the OW group (n = 233) and the OB group (n = 245), with a mean BMI of 23 ± 1.5 kg/m2, 27.4 ± 1.4 kg/m2 and 34.4 ± 3.8 kg/m2, respectively. The mean follow-up was 13.3 years (4.8-20.3). The mean mechanical tibiofemoral angle corrections were in the HW group: 7.1 ± 3°, OW group: 6.6 ± 3.5° and OB group: 7.1 ± 3.8°, with no intergroup significant difference (p = n.s.). Clinically, despite lower preoperative scores in the OW and OB groups, no difference was observed postoperatively amongst the three groups. The overall complication rate was 12.5% in the HW group, 6.8% in the OW group, and 9.8% in the OB group. There was no significant difference in the RR of complications between the HW and OW groups (RR = 0.6, 95% confidence interval [CI] = 0.3-1.3) (p = 0.2), and the HW and OB groups (RR = 0.8; 95% CI = 0.3-2.2) (p = 0.7). There was no overall significant difference in survival outcomes based on the BMI between the three groups (p = 0.4). The HR of conversion to arthroplasty between the HW and OW groups was 1.4 [95% CI = 0.6-3.5](p = 0.5) and between the HW and OB groups was 1.8 [95% CI = 0.8-4.4] (p = 0.2).

CONCLUSION

BMI has no significant effect on either the radiological corrections, clinical outcomes, complications or survivorship of MOWHTO at short- to medium-term follow-up. No specific cutoff point for BMI can be recommended as a contraindication to MOWHTO.

LEVEL OF EVIDENCE

Level IV, Retrospective cohort study.

A new technique of autologous bone grafting for open-wedge high tibial osteotomy

Purpose

This study aimed to demonstrate the application of orthotopic bone flap transplantation with a fibula transplantation (OBFT-FT) in open-wedge high tibial osteotomy (OW-HTO) and to assess the effect of OBFT-FT on gap healing.

Patients and methods

From January to July 2020, 18 patients who underwent OW-HTO with OBFT-FT were reviewed for this study. Demographics, postoperative complications, and radiological and clinical outcomes of patients were collected. Finally, the clinical outcomes of patients were analyzed.

Results

A total of 14 patients were included in this study. The average age and body mass index were 59.6 ± 9.2 years and 28.1 ± 4.5 kg/m2, respectively. The average correction angle and gap width were 9.5 ± 1.8° and 10.2 ± 2.7 mm, respectively. The rates of radiological gap healing at sixth week, third month, and sixth month were 42.9%, 85.7%, and 100%, respectively. The mean Lysholm score, International Knee Documentation Committee score, and visual analog scale scores at sixth-month follow-up were significantly better than the preoperative scores (p < 0.001, p < 0.001, p = 0.001, respectively). And, no delayed union or non-union, collapse, loss of correction, or surgical site infection were found.

Conclusions

As a new technique for autologous bone graft, the OBFT-FT could be successfully applied in the treatment of gap healing after OW-HTO, and excellent radiological and clinical outcomes could be seen on patients' short-term follow-up.

Obesity does not impact complications and conversion to total knee arthroplasty after high tibial osteotomy: A systematic review

PURPOSE

The purpose of this systematic review is to consolidate outcomes of obese patients undergoing high tibial osteotomy and to investigate the effect of obesity on postoperative outcomes, including symptomatic relief and time to conversion to arthroplasty.

METHODS

Medline, Embase and Cochrane Library were searched from database inception up to April 2023 according to PRISMA guidelines by two reviewers. Search terms including 'obesity', 'BMI', 'osteotomy' and 'high tibial osteotomy (HTO)' were included to identify all relevant articles. Only studies that explicitly reported outcomes for obese patients were included. Disagreements in study inclusion or quality assessment were resolved by a senior third reviewer. Metrics compared include time to arthroplasty, preoperative and postoperative mechanical tibiofemoral angle (mTFA), patient-reported satisfaction scores and postoperative complications.

RESULTS

Nine studies comparing 973 patients were included. The mean age was 52.7 ± 4.2 years old and 38.4% were male. Six studies performed the medial opening-wedge HTO, and three utilized the medial wedge closing technique. Most studies indicated significant improvement following surgical intervention with satisfactory outcomes in obese and nonobese patients. In addition, differences in complication rates were minimal between obese and nonobese patients (n.s.), while functional scores did not vary significantly. Conversion to total knee arthroplasty was not found to increase in obese patients (n.s.).

CONCLUSION

Obesity does not appear to carry a greater complication risk or worse outcomes following high tibial osteotomies, and surgeons should consider HTO a viable option for young obese patients with symptomatic unicompartmental chondral wear with coronal limb malalignment.

LEVEL OF EVIDENCE

Level IV.

Earlier consolidation and improved knee function of medial open wedge high tibial osteotomy with autologous bone graft

PURPOSE

Medial knee osteoarthritis can be treated with medial open wedge high tibial osteotomy (OWHTO). We sought to investigate osseous consolidation of the osteotomy with and without autologous bone grafts (ABG) to detect possible benefits of ABG in osseous healing and functional outcome.

METHODS

In this prospective study, patients without graft transplantation were compared to those receiving ABG after medial OWHTO. They were followed up 6 weeks, 12 weeks, 6 months and 12 months postoperatively. Radiographic progress of consolidation, clinical scores, contrast-enhanced ultrasound (CEUS) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) were assessed at each appointment.

RESULTS

A total of 35 patients were enrolled, 20 without and 15 with graft transplantation. Radiologic evaluation showed a significantly earlier consolidation of the osteotomy gaps (p = 0.012) in patients with ABG, resulting in a significantly higher rate of consolidation 12 months after surgery (60% without bone graft vs. 100% with bone graft, p = 0.006). At 6 weeks as well as 6-month follow-up, a tendency of earlier consolidation with ABG was apparent, but not statistically significant (6 weeks: 50% vs. 80%, p = 0.089; 6 months: 30% vs. 60%, p = 0.097). CEUS and DCE-MRI showed physiological perfusion of the osteotomy gaps in both groups. A tendency to better function and less pain in patients with ABG was recognizable.

CONCLUSION

In our study, autologous bone grafting evocated earlier osseous consolidation after medial OWHTO and showed a tendency to a better functional outcome.

Incidence of Complications and Revision Surgery After High Tibial Osteotomy: A Systematic Review

BACKGROUND

High tibial osteotomy (HTO) is a well-recognized procedure for its effectiveness in treating symptomatic early knee arthritis and malalignment. Although there are numerous systematic reviews evaluating the management and outcomes after HTO, there are few investigations on complications of this procedure.

PURPOSE

To systematically review the literature to determine the incidence of intraoperative and postoperative complications associated with medial opening wedge and lateral closing wedge HTOs.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

The Cochrane Database of Systematic Reviews, PubMed, Embase, and MEDLINE databases were queried for studies reporting complications associated with HTO with or without concomitant procedures. Data including patient characteristics, procedure type, concomitant procedures, follow-up time, and postoperative imaging were extracted. Rates of intra- and postoperative complications, reoperations, and conversion to arthroplasty were recorded.

RESULTS

A total of 71 studies were included for analysis, comprising 7836 patients. The overall intraoperative complication rate during HTO was 5.5% (range, 0%-29.3%), and the overall postoperative complication rate was 6.9% (range, 0%-26.6%). The most common intraoperative complication was lateral hinge fracture (incidence, 9.1%; range, 0%-30.4%) in medially based HTOs and peroneal nerve injury in laterally based HTOs (incidence, 3.2%; range, 0%-8.7%). The overall incidence of neurovascular injury after medially or laterally based HTOs was 1.1% (range, 0%-18.9%). The most common postoperative complication was superficial infection (incidence, 2.2%; range, 0%-13%). Of the included studies, 62 included postoperative radiographic analysis, and among those, the incidence of nonunion was 1.9% (range, 0%-15.5%), loss of correction was 1.2% (range, 0%-34.3%), and implant failure was 1.0% (range, 0%-10.2%). Among studies reporting revision surgeries, the overall reoperation rate was 15.5% (range, 0%-70.7%), with the most common type of reoperation being hardware removal (incidence, 10.0%; range, 0%-60%).

CONCLUSION

Intraoperatively, medially based HTOs are associated with a 1 in 11 risk of lateral hinge fracture and laterally based HTOs with a 1 in 30 risk of peroneal nerve injury. Postoperative complication rates in the range of 10% to 15% can be expected, including infection (2.9%), loss of correction (1.2%), and nonunion (1.9%). Patients should also be counseled that the reoperation rate is approximately 15%, with hardware removal being the most common procedure.

Better clinical outcomes and faster weight bearing after medial opening-wedge high tibial osteotomy using allogeneic than synthetic graft: A secondary analysis of a Francophone Arthroscopy Society Symposium

INTRODUCTION

Although an autogenous graft has the highest rate of bone union to fill the void created in medial opening wedge high tibial osteotomy (MOWHTO), it also has some disadvantages, such as prolonged surgical time, donor site pain and morbidity. Two possible candidates for ideal grafts to replace autogenous grafts are allogeneic and synthetic graft, which are free from donor site pain and morbidity. However, previous reports comparing the clinical results of allogeneic to synthetic graft have been limited and controversial. The purpose of this study is to compare radiological findings and clinical outcomes of using synthetic versus allogenic graft to fill the void created in MOWHTO.

HYPOTHESIS

The present clinical study hypothesized that allogenic graft to fill the void would allow the higher rate of bone union and better clinical outcomes.

MATERIAL AND METHODS

This study compared the clinical and radiological outcomes of 95 patients who received MOWHTO to fill the void with either synthetic or allogenic graft (44 in Syn group, 51 in Allo group). Preoperatively and postoperatively, all patients were clinically evaluated; Return to work, Tegner activity score, and the Western Ontario and Macmaster University scores were reported. Radiographically, osteoarthritis grade and pre- and postoperative parameters were reported, including Hip-knee-ankle angle, mechanical lateral distal femoral angle, medial proximal tibial angle, joint line convergence angle, proximal posterior tibial angle, and limb length discrepancy. Perioperative details and complications were also reported.

RESULTS

Mean follow-up (months) were 24.0±1.3 in Syn group and 26.8±1.2 in Allo group (p=0.13). The postoperative improvement of pain and global WOMAC scores in Allo group were significantly better than in Syn group (ΔPain of WOMAC: Syn group 27.8±4.4, Allo group 49.3±3.8, p value <0.001*) (ΔGlobal score of WOMAC: Syn group 16.7±3.2, Allo group 37.4±4.9, p value=0.002*). The risk of hinge fracture in Syn group was significantly higher than in Allo group (Hinge fracture by Takeuchi grade (0/1/2/3): Syn group 37/3/3/1, Allo group 43/8/0/0, p value=0.04*). The timing of full weight bearing in Allo group was significantly earlier than in Syn group (Weight Bearing (1=FWB, 2=PWB 3wk, 3=PWB 6wk): Syn group 2.7±0.1, Allo group 2.3±0.1, p value=0.01*).

DISCUSSION

The use of allogenic graft to fill the void in MOWHTO does not show superiority in bone union compared to synthetic graft, however it improves pain, function, decreases the risk of hinge fracture and allows faster weight bearing than synthetic graft.

LEVEL OF PROOF

III; Case-control study.

Angle Stable Plate Fixation vs Hemicallotasis in Medial Opening Wedge High Tibial Osteotomy: A Comparative Study

Background

Varus alignment associated with medial compartment degeneration is the most common presentation of knee osteoarthritis and often presents in young active adults where arthroplasty might be unsuitable.

Purpose

To compare the accuracy of the angle stable medial high tibia plate and self-adjusting HTO (high tibial osteotomy) fixator in achieving correction of varus deformity of the knee by medial opening wedge HTO and to evaluate functionality between the groups.

Study Design

Prospective randomized control study.

Methods

Forty patients each underwent medial opening wedge high tibial osteotomy with acute correction and stabilization using the angle stable plate (ASP group) or with the hemicallotasis technique using the self-adjusting HTO external fixator (HCO group). Anatomical and functional outcomes were compared to the pre-operative values at the 6th and 12th month.

Results

The FTA (femoro-tibial axis), mechanical axis, and functional scores improved significantly in both groups. There was also a significant change in the patellar height and tibial slope. Except for a better KOOS (Knee Injury and Osteoarthritis Outcome Score) in the angle stable plate group at the 6-month follow-up, there were no significant differences between the groups.

Conclusion

Both methods of performing a medially based proximal tibial osteotomy gave equivalent outcomes at the 1-year follow-up.

Clinical and Radiological Outcomes of Double-Level Osteotomy Versus Open-Wedge High Tibial Osteotomy for Bifocal Varus Deformity

Background

In bifocal varus deformity, double-level osteotomy (DLO) is advocated to treat lower limb alignment to prevent an adverse increase in joint line obliquity.

Purpose/Hypothesis

The purpose of this study was to compare the clinical and radiological results after DLO and open-wedge high tibial osteotomy (OWHTO) in patients with combined varus deformity. It was hypothesized that DLO would improve clinical results without increasing the complication rate compared with OWHTO.

Study Design

Cohort study; Level of evidence, 3.

Methods

Inclusion criteria were medial tibiofemoral compartment pain, varus knee deformity with an abnormal medial proximal tibial angle <84° and a lateral distal femoral angle >90°, a functional anterior cruciate ligament, failure of nonoperative treatment, and a minimum 2-year follow-up with all clinical and radiological data. The rate of return to work or sports; the Knee injury and Osteoarthritis Outcome Score (KOOS); the University of California, Los Angeles (UCLA) activity score; and patient satisfaction were assessed at a minimum of 2 years of follow-up. Statistical comparison of the 2 groups was made using the chi-square or Student t test.

Results

A total of 69 consecutive patients were analyzed, of whom 38 underwent OWHTO and 31 underwent DLO surgery. A significant between-group difference was found for all radiological parameters; in particular, there was less joint line obliquity after DLO compared with OWHTO (1.7° vs 5.6°; P < .001). DLO provided better outcomes compared with OWHTO regarding the UCLA score (4.3 vs 6.7; P < .001) and patient satisfaction (2.6 vs 3.9; P < .001), but no significant difference in KOOS or return to work or sports was observed. The OWHTO group had more hinge fractures than the DLO group (34.2% vs 12.9%; P < .001).

Conclusion

For combined tibial and femoral varus deformity, DLO produced more physiologic joint line obliquity with slightly improved UCLA and patient satisfaction scores. A greater incidence of hinge fracture was observed after isolated OWHTO compared with DLO due to a larger tibial correction; however, this had little effect on clinical results at the 2-year follow-up.

Lack of Efficacy of Bone Void Filling Materials in Medial Opening-Wedge High Tibial Osteotomy: A Systematic Review and Network Meta-Analysis

PURPOSE

To systematically review the clinical and radiologic outcomes of isolated medial opening-wedge high tibial osteotomies with different bone void filling materials and to compare the outcomes by network meta-analysis.

METHODS

This systematic review and network meta-analysis included searches of Medline, Embase, Cochrane Library, Web of Science, and Scopus from inception to July 30, 2022, for clinical comparative studies comparing 2 or more bone void filling materials in patients undergoing medial opening-wedge high tibial osteotomies. We performed Bayesian random-effect network meta-analyses to summarize the evidence and applied the Grading of Recommendations Assessment, Development, and Evaluation frameworks to rate the certainty of evidence, calculate the absolute effects, and present the findings. Cochrane Risk of Bias Tool 2.0 and modified Newcastle-Ottawa Scale were used to assess the risk of bias.

RESULTS

In total, 2,755 citations were identified by our search, of which 25 eligible trials, including 10 randomized controlled trials and 15 nonrandomized comparative trials (NCTs) enrolled 1,420 participants and 6 different interventions (autografts, allografts, synthetic grafts, mixed grafts, xenografts, and without grafts). There were some concerns on the risk of bias assessment among randomized controlled trials, and the median Newcastle-Ottawa Scale score was 6 for NCTs. All fillers showed no significantly superior treatment effects when compared with unfilled group in final Knee Society Scoring, Western Ontario and McMasters Universities score, time to bone union (TBU), and loss of correction (LOC). Exceptionally, moderate-certainty evidence suggested that autograft would produce superior incidence of complete bone union (CBU) than the unfilled at postoperative 1 year (odds ratio [OR] 13.0, 95% confidence interval [CI] 1.60-95.6), whereas low- to very low-certainty evidence suggested allografts (OR 0.2, 95% CI 0.06-0.52) and synthetic grafts (OR 0.29, 95% CI 0.10-0.68) would result in inferior CBU. Low-certainty evidence suggested allografts would result in larger LOC angle than unfilled group (mean difference 1.1, 95% CI 0.1-2.3). As for TBU, low-certainty evidence suggested mixed grafts would take longer time to reach clinical bone union (mean difference -14.04, 95% CI -21.0 to -6.9).

CONCLUSIONS

There is a lack of efficacy for different bone void filling materials to result better outcomes in Knee Society Scoring, Western Ontario and McMasters Universities score, TBU, and LOC than without graft. Although applying the autografts would produce a superior possibility of radiologic CBU than other fillers, because of the inclusion of NCTs, the overall certainty of the evidence synthesis is low.

LEVEL OF EVIDENCE

Level Ⅲ, meta-analysis of Level I randomized controlled trials and Level Ⅱ∼Ⅲ non-randomized comparative trails.

General Considerations About Foot and Ankle Arthrodesis. Any Way to Improve Our Results?

Nonunion and adjacent joint osteoarthritis (OA) are known complications after a fusion procedure, and foot and ankle surgeons are commonly exposed to such disabling complications. Determining who is at risk of developing nonunion is essential to reducing nonunion rates and improving patient outcomes. Several evidenced-based modifiable risk factors related to adverse outcomes after foot and ankle arthrodesis have been identified. Patient-related risk factors that can be improved before surgery include smoking cessation, good diabetic control (HbAc1 <7%) and vitamin D supplementation. Intraoperatively, using less invasive techniques, avoiding joint preparation with power tools, using bone grafts or orthobiologics in more complex cases, high-risk patients, nonunion revision surgeries, and filling in bone voids at the arthrodesis site should be considered. Postoperatively, pain management with NSAIDs should be limited to a short period (<2 weeks) and avoided in high-risk patients. Furthermore, early postoperative weight-bearing has shown to be beneficial, and it does not seem to increase postoperative complications. The incidence of surrounding joint OA after foot and ankle fusion seems to increase progressively with time. Owing to its progression and high probability of being symptomatic, patients must be informed consequently, as they may require additional joint fusions, resulting in further loss of ankle/foot motion. In patients with symptomatic adjacent joint OA and unsatisfactory results after an ankle arthrodesis, conversion to total ankle arthroplasty (TAA) has become a potential option in managing these complex and challenging situations.

Femoral morphology affects postoperative alignment of the lower extremities in hybrid closed-wedge high tibial osteotomy

INTRODUCTION

This study aimed to determine correction error predictors of lower extremitiy alignment after hybrid closed-wedge high tibial osteotomy (HCWHTO).

MATERIALS AND METHODS

From 2011 to 2015, 102 knees in 75 patients with medial compartment knee osteoarthritis of the knee and varus knee deformities who underwent HCWHTO were evaluated in this retrospective study with a minimum 2-year follow-up. Preoperative radiological parameters including weight-bearing line ratio (WBL ratio), mechanical leg axis angle, mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), and JLCA under varus or valgus stress were measured. The knees were divided into the following three groups based on the WBL ratio on average 54 months after procedure: acceptable (WBL crossing the tibial plateau between 50 and 70%), under-correction (< 50%), and overcorrection (> 70%). A multiple regression analysis was performed to evaluate predictors that could influence postoperative WBL ratio and cut-off values of predictive preoperative factors was analysed.

RESULTS

Significant differences in pre- and postoperative WBL ratios and mechanical leg axis angles were found. Preoperative mLDFA in the under-correction group (89.4° ± 2.1°) was significantly higher than that in the overcorrection group (87.4° ± 2.2°) (p = 0.015), while other preoperative parameters revealed no significant differences. The postoperative MPTA in the under-correction group (92.1° ± 3.7°) was significantly lower than that in the other two groups (p = 0.005 and p = 0.0001, respectively), while there was no significant change between the acceptable (94.6° ± 3.4°) and the overcorrection (96.7° ± 3.2°) groups. Multiple regression analysis revealed that mLDFA (β =  - 0.316; p = 0.010) had a significant impact on postoperative WBLR. The cut-off value for under-correction of mLDFA was 89.5°and sensitivity and specificity were 53.6 and 71.6%, respectively (p = 0.014).

CONCLUSIONS

Preoperative mLDFA is significantly associated with postoperative alignment in HCWHTO. While postoperative MPTA is important, disregarding the preoperative mLDFA may bears a high risk of malcorrection. Varus alignment of the knee with larger mLDFA may be an indication for not only HCWHTO, but also for distal femoral osteotomy.

Combined use of beta-tricalcium phosphate with different porosities can accelerate bone remodelling in open-wedge high tibial osteotomy

Background/Objective

Beta-tricalcium phosphate (β-TCP) is often used as a gap filler in open-wedge high tibial osteotomy (OWHTO). The aim of the present study was to investigate the effects of using β-TCP with different porosities on bone remodelling after OWHTO.Methods: We evaluated 29 knees in 26 patients that underwent OWHTO using β-TCP with porosities of 60% and 75% (combined group). A further 30 knees in 28 patients that underwent OWHTO using β-TCP with 60% porosity alone were allocated as a control group. In the combined group, a β-TCP block with 75% porosity was inserted into the gap at the cancellous bone site and a β-TCP block with 60% porosity was inserted into the medial cortical bone side. In the control group, a β-TCP block with 60% porosity was inserted into the osteotomy gap. The bone remodelling phases of the inserted β-TCP blocks were evaluated on standard anteroposterior radiographs using the modified van Hemert classification at 3 and 6 months post-operatively.

Results

The rate of satisfactory bone remodelling at the cancellous bone sites was 86.2% (25/29) in the combined group and 0% (0/30) in the control group at 3 months post-operatively (p<0.05), progressing to 96.6% (28/29) in the combined group and 20% (6/30) in the control group at 6 months post-operatively (p<0.05).

Conclusion

The present study demonstrated that combined use of β-TCP with high and low porosities can significantly enhance bone formation. The combined use of artificial bones with different porosities is useful for early bone remodelling in OWHTO.

Overweight patients benefit from high tibial osteotomy to the same extent as patients with normal weights but show inferior mid-term results

PURPOSE

The purpose of this prospective study was to analyze the impact of obesity on the clinical and radiological outcomes 6 years after open-wedge high tibial osteotomy (HTO).

METHODS

A total of 120 prospectively recorded patients with medial compartment osteoarthritis underwent open-wedge HTO between 2008 and 2011. The study cohort was frequently examined over a minimum of a 6-year follow-up. The cohort was divided into three groups according to body mass index (BMI): normal weight patients (BMI < 25 kg/m²), pre-obese patients (BMI 25-30 kg/m²) and obese patients (BMI > 30 kg/m²). Clinical and functional outcomes (Oxford Knee Score, Hospital for Special Surgery Score, Lequesne Score, Tegner Activity Scale), subjective health-related quality of life (SF-36), change in mechanical limb alignment (mTFA) as well as conversion to unicompartmental or total knee arthroplasty (TKA) were evaluated. To compare clinical scoring between the groups, univariate variance analysis was applied. Changes in outcome variables over time were analyzed with dependent t tests.

RESULTS

From 120 patients, 85 were followed-up over a 6.7-year period on average (6-11.8 years) after HTO. The mean BMI was 28.6 ± 4.6 kg/m². Each group showed a significant pre- to postoperative increase in all recorded scores (p < 0.05). In absolute terms, both mental and clinical scores of overweight patients did not reach the peak values of the normal weighted population during the period of observation. There was a conversion to TKA in 10.5% after an average of 50.1 ± 25.0 months following surgery. A total of five complications occurred without significant differences (BMI < 25: n = 1, BMI 25-30: n = 2, BMI > 30: n = 2; n.s.). There was a mean pre- to postoperative (six weeks after surgery) correction difference of 6.9° ± 3.2° (mTFA) with higher loss of correction over time in overweight patients.

CONCLUSION

In terms of clinical outcome and health-related quality of life, overweight patients may receive a benefit from open-wedge HTO to the same extent as patients with normal weights and show similar complication rates. However, they have inferior preoperative clinical and functional results and mid-term results after open-wedge HTO compared to patients with normal weights.

LEVEL OF EVIDENCE

Level III.

Impact of tourniquet on short-term outcomes in opening wedge high tibial osteotomy with modern tranexamic acid protocols: a retrospective cohort study

BACKGROUND

The use of a tourniquet during high tibial osteotomy (HTO) is a routine procedure, but there is currently no research on the benefits and potential risks of tourniquet use during HTO. The aim of this study was to investigate the impact of tourniquet on perioperative blood loss, early functional recovery and complications in opening wedge HTO with modern tranexamic acid protocols.

METHODS

This was a retrospective cohort study of patients who underwent unilateral opening wedge HTO between January 2019 and September 2020. All patients were divided into two groups according to whether a tourniquet was applied during HTO. Patients in both groups received the same surgical procedures, tranexamic acid protocols and other perioperative treatments. Preoperative baseline data, intraoperative data, early postoperative recovery and all complications during the 3-month follow-up were collected and compared between the two groups.

RESULTS

A total of 62 patients were enrolled in this study, including 32 in the tourniquet group and 30 in the non-tourniquet group. There was no significant difference in preoperative baseline data between the two groups (P > 0.05 in all). Intraoperative blood loss in the tourniquet group was significantly lower than that in the non-tourniquet group (80.22 ml versus 94.00 ml, P < 0.001), but there was no difference in total blood loss (187.39 ml versus 193.31 ml, P = 0.714). And no patient in either group required blood transfusion. In terms of early postoperative recovery, tourniquet use significantly increased pain scores and reduced knee range of motion on the first and second postoperative days, but there was no significant difference between the two groups at postoperative third day and third month. Furthermore, there was no significant difference between the two groups in terms of lower limb force line correction, length of stay, Knee Society Score or the incidence of complications during the 3-month follow-up (P > 0.05 in all).

CONCLUSIONS

In opening wedge HTO with modern tranexamic acid protocols, not using a tourniquet does not increase perioperative total blood loss or the risk of complications, but facilitates early postoperative recovery by reducing pain and increasing range of motion.

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.

Association of Gap Healing With Angle of Correction After Opening-Wedge High Tibial Osteotomy Without Bone Grafting

Background:

Studies have reported that opening wedge high tibial osteotomy (OWHTO) without bone grafting has outcomes that are similar to or even better than those of OWHTO with bone grafting, especially after use of a locking plate. However, a consensus on managing the gap after OWHTO has not been established.

Purpose:

To determine the degree of gap healing achieved without bone grafting, the factors associated with gap healing, and whether additional gap healing would be obtained after plate removal.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

This retrospective study included 73 patients who underwent OWHTO without bone grafting between 2015 and 2018. Patients in the study were divided into 2 groups based on the correction angle: small correction group (<10°; SC group) and large correction group (≥10°; LC group). The locking plate used in OWHTO was removed at a mean of 13.5 months after surgery in 65 patients. Radiographic indexes were measured: gap filling height, gap vacancy ratio (GVR), and osteotomy filling index. The acceptable gap healing was defined as an osteotomy filling index ≥3. The factors related to gap healing around the osteotomy site were selected after multicollinearity analysis.

Results:

Although both groups achieved acceptable gap healing regardless of the correction angle, the SC group showed higher and earlier gap healing than did the LC group (gap healing rate 81.4% in the SC group vs 41.7% in the LC group at 3 months postoperatively). The GVR was 8.6% in the SC group and 15.3% in the LC group at 12 months after surgery (P = .005). Both the amount of time that elapsed after surgery and the correction angle were associated with gap healing (P < .05). Additional gap healing was observed after plate removal, as the GVR decreased 2.7% more in the patients with plate removal than in patients who did not have plate removal (P = .012).

Conclusion:

All patients achieved acceptable gap healing without bone graft. The degree of gap healing was higher in the SC group and increased over time. Gap healing was promoted after plate removal. Considering the results of this study, a bone graft is not necessary in routine OWHTO in terms of gap healing.

Can low intensity pulsed ultrasound (LIPUS) be used as an alternative to revision surgery for patients with non-unions following fracture fixation?

BACKGROUND

Non-union is a significant complication of fracture fixation surgery, and can negatively impact a patient's quality of life. Low intensity pulsed ultrasound (LIPUS) has been used to treat delayed or non-unions previously in the literature. The aim of this study was to determine the success rate of LIPUS treatment in patients with chronic fracture non-unions, and to establish the effect of systemic or local factors on its success.

METHODS

This was a retrospective, observational study which included all patients undergoing LIPUS treatment in a single institution. Patients deemed suitable for LIPUS underwent treatment for a period of 6 months from initiation. They were followed up with sequential radiographs to assess union at intervals of 6 weeks, 3 months, 6 months and 1 year. LIPUS treatment was considered to be successful when patients achieved clinical and radiological union, without the need for revision surgery.

RESULTS

A total of 46 patients were included in the study; 8 were lost to follow - up, leaving 38 patients for the final analysis. The mean age of patients was 47.03 ± 19.7 with a male to female ratio of 1.2:1. Union was achieved in 57.89%; the rest underwent revision surgery. There was no significant association between outcomes after LIPUS treatment and patients' age, gender, smoking status or type of non-union. Patients with a small inter-fragment bone gap were more likely to have a successful outcome after LIPUS (p = 0.041). Time to treatment did not have a statistically significant impact on outcomes after LIPUS. Interestingly, all 6 patients with diabetes in the study managed to achieve union after LIPUS.

CONCLUSIONS

This study demonstrates that LIPUS is not successful in a large proportion of patients with established fracture non-unions. However, it does represent a low risk treatment modality as an alternative to revision surgery, especially for patients with diabetes who have a small inter - fragment bone gap. More research in the form of large randomised controlled trials needs to be carried out to further assess the role of LIPUS in the treatment of non-unions.

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.

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

PURPOSE

With surgical modifications reflecting plate design differences of the specific rigid locking plate adding a metal wedge, uniplane high tibial osteotomy (HTO) has fewer lateral-hinge fractures and fewer plate irritations than biplane HTO.

METHODS

Uniplane HTO with a rigid locking plate adding a metal wedge was compared with biplane HTO with a rigid locking plate including a proximal D-hole. For comparison, the HTO patients' medical records and radiological results in a single institution were retrospectively reviewed. The Oxford knee score 2 years post-operation, CT scan at post-operative day 2 and serial standing long-bone scanography were reviewed to evaluate clinical outcome and radiological results, including the incidence of lateral-hinge fracture, plate irritation and correction loss to varus alignment.

RESULTS

A total of 103 knees, including 59 uniplane HTO and 44 biplane HTO, were enrolled. The Oxford scores were 38.1 ± 7.8 in the uniplane group and 35.9 ± 8.3 in the biplane group (ns). On CT scans, more lateral-hinge fractures developed in the biplane group, and seven knees (12%) of the uniplane group and 12 knees (27%) of the biplane group had Takeuchi type I stable hinge fracture (p < 0.05); unstable fracture was not noted in either group. Plate irritation occurred in nine knees (19%) of the uniplane group and in 14 knees (32%) of the biplane group, and the difference was statistically significant (p < 0.05).

CONCLUSION

In clinical situations including the use of surgical modifications reflecting plate design differences, fewer lateral-hinge fractures developed after uniplane medial opening-wedge HTO compared with biplane HTO. Uniplane HTO potentially represents a better option than biplane HTO for the prevention of lateral-hinge fracture.

LEVEL OF EVIDENCE

IV.

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.

Comparable bone union progression after opening wedge high tibial osteotomy using allogenous bone chip or tri-calcium phosphate granule: a prospective randomized controlled trial

PURPOSE

The purpose of this study is to compare the progression rate of bone union and clinical outcomes of opening wedge high tibial osteotomy (OWHTO) using allogenous bone chip or tri-calcium phosphate (TCP) granule as bone graft materials. The hypothesis was that the bone union progression in OWHTOs using TCP granule grafts would be comparable to that of OWHTOs using allogenous bone chip grafts.

METHODS

Between 2011 and 2013, 54 patients who had undergone OWHTO for genu varum and osteoarthritis were randomized to one of the two groups at five centres. TCP granule was used to fill the defect in 27 patients and lyophilized allogenous bone chip was used in the other 27 patients. The degree of bone union was classified on a five-point scale and evaluated using plain radiographs of the knee at 6 weeks, 3 months, 6 months, and 12 months postoperatively. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, pain Visual Analogue Scale (VAS) score and complications were also evaluated.

RESULTS

The highest degree of bone union observed at 6 and 12 months postoperatively was grade 4, and the number of cases of union progression at each time-point was not significantly different between the two groups (p > 0.05). WOMAC and pain VAS scores also showed no differences between the two groups. No complications were observed during the 12-month period following OWHTO in either group.

CONCLUSION

OWHTO using TCP granule bone substitute showed similar bone union rates and clinical outcomes compared to allogenous bone chip grafts. TCP granule can be used as bone substitutes instead of allogenous bone chip grafts in OWHTO.

LEVEL OF EVIDENCE

Level 1.