Safety of a novel high tibial osteotomy locked plate fixation for immediate full weight-bearing: a case-control study

'One millimetre equals one degree' is a major source of inaccuracy in planning osteotomies around the knee for metaphyseal deformities compared to the digital planning

PURPOSE

The objective of this study was to compare the accuracy of virtually performed osteotomies around the knee. The comparison was made between the Miniaci method (method 1), considered the gold standard planning, with the widely held dogma that one degree of correction required equates to one millimetre of opening/closing (method 2).

METHODS

This retrospective cross-sectional study was conducted between December 2018 and September 2022 in patients aged at least 15 years with metaphyseal knee deformity. Osteotomy planning was performed in methods 1 and 2 utilising calibrated long-leg alignment X-rays in the frontal plane. In both methods, the desired correction was defined by the Fujisawa point. The error % in measurement (ratio method 1/method 2) and the difference in millimetres (method 1 - method 2) between the two methods were analysed.

RESULTS

A total of 107 osteotomies with 27 (25.2%) distal femoral osteotomies, 54 (50.5%) proximal tibial osteotomies and 26 (24.3%) double-level osteotomies were performed virtually with a mean hip-knee-ankle angle of 176.4 ± 6.6. In distal femur osteotomy, the mean error % between methods 1 and 2 was 38.9 ± 16.7% and 22.4 ± 16.8% for the opening and closing groups, respectively. In proximal tibial osteotomies, the mean error % was 22.7 ± 15.6% and 9 ± 10.8% for the opening and closing groups, respectively. In double-level osteotomy, the mean error % of femur-based corrections was 34.9 ± 19% and 19.5 ± 21% for the opening and closing groups, respectively, and the mean error of the tibial-based corrections was 26.4 ± 12.1% for the opening group and 10.8 ± 10% for the closing group, respectively.

CONCLUSION

Planning one millimeter per degree of desired correction for osteotomies around the knee in metaphyseal deformities is a major source of error when compared with digital planning using the Miniaci method. This was seen most frequently with osteotomies of the distal femur and all opening wedge osteotomies.

LEVEL OF EVIDENCE

Level Ⅲ, retrospective cross-sectional study.

Comparison of the Miniaci and Dugdale techniques on functional outcomes in medial open wedge high tibial osteotomy

PURPOSE

To compare the correction angles determined by the Miniaci and Dugdale techniques in patients treated with medial open wedge high tibial osteotomy (MOWHTO) and show their impact on clinical outcomes.

METHODS

Seventy-four patients constituted the study group. The correction angles in Group 1 were measured using the Miniaci technique, and those in Group 2 were measured using the Dugdale technique. The clinical evaluations included the Tinetti Gait and Balance Assessment (TGBA), the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) scores, and the Visual Analogue Scale (VAS). The effect of the correction angle on the patient's clinical outcomes was evaluated. Measurement techniques were also changed between groups for comparison.

RESULTS

Seventy-four patients (62 females, 12 males) with a mean age of 53.7 ± 4.9 years were followed up for a mean of 67.4 ± 5.5 months. The TGBA, WOMAC, and VAS scores were improved at the last follow-up compared to the preoperative scores (p < 0.05). The preoperative TGBA and WOMAC scores were not significantly different between the two groups, but the last follow-up TGBA and WOMAC scores in Group 2 were worse than those in Group 1 (p < 0.05). When measuring techniques were changed, the preoperative correction angle (PCA) value and the last follow-up correction angle (LFCA) value were lower in Group 1 measured with the Dugdale technique but higher in Group 2 measured with the Miniaci technique (p < 0.05).

CONCLUSION

Since the correction angle values measured with the Miniaci technique in MOWHTO are higher than those measured with the Dugdale technique; the functional results are better.

LEVEL OF EVIDENCE

Retrospective cohort study, III.

Outcomes of double level osteotomy for osteoarthritic knees with severe varus deformity. A systematic review

BACKGROUND

When correcting severe genu varus deformity, knee surgeons must choose between performing a single or double-level osteotomy. This systematic review aims to provide this equipoise with some clarity.

PATIENTS AND METHODS

We conducted this study following the Preferred Reporting Items for Systematic Reviews and Meta-analyses Statement (PRISMA) and the Cochrane Handbook for systematic reviews and meta-analysis. Studies evaluating the effect of the double level osteotomy (DLO) or those comparing it to high tibial osteotomy (HTO) from all regions and written in any language were included.

RESULTS

Six studies were included in this systematic review. They were prepared and analysed using Review Manager V5.0 [Computer Program] (RevMan5). Performing DLO resulted in restoring patellar height, joint-line convergence angle (JLCA), and mMPTA to normal values. DLO was also more successful at avoiding joint line obliquity (JLO) in severe varus deformity when compared to HTO (P < 0.001). No significant difference was reported between the two cohorts regarding the mLPTA. DLO resulted in satisfactory short term KOOS and IKDC scores. The complication rate after DLO was 2.28%.

CONCLUSIONS

DLO showed a low complication rate and satisfactory short term KOOS and IKDAC scores. Randomised control trials with long term follow-up comparing the DLO and HTO are recommended.

Effects of plate contouring quality on the biomechanical performance of high tibial osteotomy fixation: A parametric finite element study

Locking plates have threaded holes, in which threaded-head screws are affixed. Hence, they do not need to be in intimate contact with underlying bone to provide fixation. There are, however, reports that a large distance between the plate and the bone might cause clinical complications such as delayed union or nonunion, screw pull out, and screw and plate breakage. Considering the diversity in the capabilities and costs of different plate customization techniques, the purpose of this study was to investigate the effect of the plate contouring quality on the biomechanical performance of high tibial osteotomy (HTO) fixation. A finite element model of proximal tibia was developed in Abaqus, using the QCT data of a cadaver. The model was then subjected to open-wedge HTO (correction angle 12°) with TomoFix plate fixation. The sagittal curvature of the plate was changed parametrically to provide certain levels of geometrical fit, and the biomechanical performance parameters of fixation were assessed. Results indicated 5%, 9% and 38% increase in the stiffness of the construct, and the von Mises stress in the plate and locking screw just above the osteotomy site, respectively, when the level of fit of plate changed from 0% (initial non-contoured initial shape) to 100% (fully adapted shape). The same change decreased the pressure at the lateral hinge of the osteotomy by 61%, and the mean of the tensile stress on the screw shaft by 12%. It was concluded that the level of fit has conflicting effects on the biomechanical parameters of the HTO fixation system, that is, the structural stiffness, the pressure at the lateral hinge, the stresses in the plate and screws, and the pull out resistance of the screws. In particular, for HTO patients with high quality bone, the optimal level of fit should provide a tradeoff between these parameters.

How to achieve an optimal alignment in medial opening wedge high tibial osteotomy?

Medial opening wedge high tibial osteotomy (MOWHTO) is a widely used surgical treatment option for medial compartmental osteoarthritis with varus deformity. It is important that proper lower limb alignment is achieved. However, there has been no consensus about an optimal alignment in MOWHTO. Most studies suggest that achieving valgus alignment is necessary, and recent studies support slight valgus mechanical alignment of less than 3° of mechanical femorotibial angle. Overcorrection and undercorrection is not recommended for achieving good surgical outcomes. To prevent undercorrection and overcorrection in MOWHTO, the method of placing the weight-bearing line in the target range must be precise. There are several ways to place a weight-bearing line within the target range. While the most important factor for a successful MOWHTO is achieving an ideal mechanical axis correction, there are a few other factors to consider, including joint line obliquity, posterior tibial slope, ligament balancing, and patellar height. Several factors exist that lead to undercorrection and overcorrection. Preoperative amount of varus deformity, lateral hinge fracture, and fixation failure can result in undercorrection, while medial soft tissue laxity and the amount of correction angle and target point beyond hypomochlion can result in overcorrection. This study aimed to review the literature on optimal alignment in MOWHTO and report on the factors to be considered to prevent correction errors and how to achieve an optimal alignment.

Simultaneous bilateral opening-wedge high tibial osteotomy with structural allograft impaction results in excellent early recovery and pain reduction similar unilateral osteotomy

BACKGROUND

Patients suffering from bilateral combined medial osteoarthritis and varus alignment of the knee are eligible for bilateral high tibial osteotomy (HTO) in two-staged surgery. The impact of bilateral HTO surgery on rehabilitation and early outcomes have not yet been reported in the literature, even though these features are decisive in establishing whether a patient is preferably treated in one or two stages.

METHODS

A total of 29 patients were followed after simultaneous bilateral HTO surgery. Numeric Rating Scale (NRS), Knee injury and Osteoarthritis Outcome Score - Physical Function Short Form (KOOS-PS) and Lysholm scores were recorded at 3, 6 and 12 months. Results were compared with outcomes of unilateral HTO surgery to asses the additional impact of simultaneous bilateral HTO surgery on the early rehabilitation and recovery of simultaneous bilateral HTO surgery.

RESULTS

Three months after surgery, NRS pain scores decreased from 60.5 to 40.9 and subsequently to 30.4 and 24.3 after 6 and 12 months, respectively. KOOS-PS scores improved from 50.0 to 44.3 after 3 months, to 33.9 and 29.8 after 6 and 12 months, respectively. Lysholm scores did not improve after 3 months (45.2-44.2), but significantly improved after 6 and 12 months (66.1 and 75.7, respectively). Compared with unilateral HTO surgery, similar improvements were seen after 6 and 12 months.

CONCLUSION

Simultaneous bilateral HTO surgery generates similar clinical outcomes compared with unilateral HTO surgery and moreover it does not excessively prolong time to achieve these outcomes. It is safe and presumably a more effective approach to treat patients suffering bilateral medial osteoarthritis and varus alignment of the knee compared with two-staged surgery.

Structural allograft impaction enables fast rehabilitation in opening-wedge high tibial osteotomy: a consecutive case series with one year follow-up

PURPOSE

Painful and slow recovery are the presumed disadvantages after opening-wedge high tibial osteotomy (HTO) and play a role in favouring arthroplasty as treatment for moderate isolated medial knee arthritis. The primary study objective was to investigate the effect of press-fit structural impacted bone allograft with locking plate fixation on early ambulation, postoperative pain levels, and resumption of daily-life activities in opening-wedge HTO.

METHODS

A prospective consecutive opening-wedge HTO case series was conducted, including 103 patients with final follow-up at 1 year. Weight-bearing was allowed from the day after surgery "as tolerated" by the patient. Clinical assessment included the Numeric Rating Scale (NRS), Knee injury and Osteoarthritis Outcome Score (KOOS), and Lysholm score. Additionally, the Knee Society Score (KSS) was assessed during consultation at 1, 3, and 12 months postoperatively with special attention for clinical anchor questions. Required sample size was calculated and a linear mixed-effect model was used for repeated measures over time of the clinical scores.

RESULTS

The NRS decreased by 1.5 at 1 month (p < 0.01) and 2.1 at 3 months (p < 0.01), while KOOS pain significantly improved with 19.2 (p < 0.01) by this time compared to baseline. Under reduced pain levels, 98% were able to walk > 500 m without support, while all patients were able to climb up and down the stairs 3 months postoperatively.

CONCLUSION

The study strongly supports the initial hypothesis that applying structural triangular bone allograft in HTO leads to low postoperative pain levels, early ambulation, and excellent short-term clinical outcomes. Study results have the potential to alter the general perception about HTO being a painful procedure with painstakingly slow recovery and consequently encourage the consideration of HTO as a highly valuable joint-preserving option, while treating unicompartmental knee arthritis.

LEVEL OF EVIDENCE

IV (case series).

Dome-shaped high tibial osteotomy with semi-circular Ilizarov pin fixator: Mid- to long-term results of a novel technique

BACKGROUND

The aim of this study was to assess the clinical and radiological results of the dome-shaped high tibial osteotomy (HTO) which was fixed with a novel construct comprised of semi-circular Ilizarov frames and pins.

METHODS

The patients with at least five years of follow-up were evaluated. One-hundred and thirty-two knees of 114 patients were included in the final analysis. The clinical evaluation included range of motion and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score. Anatomical femorotibial angle (aFTA), anatomical medial proximal tibial angle (aMPTA), tibial slope and Insall-Salvati ratio were calculated on standard weight-bearing radiographs.

RESULTS

The average aFTA was improved from 1.6° varus to 8.7° valgus (P < 0.001). The average WOMAC score (P < 0.001) and flexion value (P = 0.014) were improved at the latest follow-up (WOMAC: 17.2, flexion: 142.5) compared with the preoperative period (WOMAC: 59.6, flexion: 129.2). The sagittal radiological parameters were not significantly affected. The five-year survival was 96.2%, and 10-year survival was 83.3%.

CONCLUSIONS

The semi-circular Ilizarov pin construct provided satisfactory outcomes both clinically and radiologically at mid- to long-term follow-up.

Preliminary Evaluation of the Efficacy of Postoperative Early Weight-bearing Rehabilitation Protocol for Patients after Double-level Osteotomy

Objective:

There are no reports describing in detail postoperative rehabilitation after double-level osteotomy (DLO). Consequently, the establishment of a safe and effective rehabilitation protocol is required.

Methods:

This retrospective study included 26 patients with varus knees who underwent DLO. No patient had obvious fracture around the femoral osteotomy sites, as evaluated using computed tomography (CT) 3 weeks postoperatively. From 3 days postoperatively, gait training with early weight bearing was performed using our parallel bar protocol. Range of motion exercises were permitted as tolerated. Radiological evaluation was performed to confirm the presence or absence of fracture around the femoral osteotomy sites using CT at 3 weeks and X-ray at 6 weeks postoperatively. X-ray imaging 6 months postoperatively indicated no femoral correction loss. Additionally, the time from initiation to completion of the protocol and the time from initiation to achievement of independent gait were recorded.

Results:

No fractures around the femoral osteotomy sites in any patient were found using CT 3 weeks postoperatively and X-rays 6 weeks postoperatively. There was no correction loss at the femoral osteotomy site according to X-ray findings 6 months postoperatively. The mean time until completion of the parallel bar protocol was 19.8 ± 6.2 (7–30) days, and that from the initiation of rehabilitation to the achievement of independent gait was 26.8 ± 7.1 (16–45) days.

Conclusion:

Patients without fracture around the femoral osteotomy site during the rehabilitation period could achieve independent gait within an average of <1 month using the parallel bar protocol. Early weight-bearing walking and independent walking could be achieved using this protocol.

In vitro and in vivo biocompatibility of calcium-phosphate scaffolds three-dimensional printed by stereolithography for bone regeneration

Stereolithography (SLA) is an interesting manufacturing technology to overcome limitations of commercially available particulated biomaterials dedicated to intra-oral bone regeneration applications. The purpose of this study was to evaluate the in vitro and in vivo biocompatibility and osteoinductive properties of two calcium-phosphate (CaP)-based scaffolds manufactured by SLA three-dimensional (3D) printing. Pellets and macro-porous scaffolds were manufactured in pure hydroxyapatite (HA) and in biphasic CaP (HA:60-TCP:40). Physico-chemical characterization was performed using micro X-ray fluorescence, scanning electron microscopy (SEM), optical interferometry, and microtomography (μCT) analyses. Osteoblast-like MG-63 cells were used to evaluate the biocompatibility of the pellets in vitro with MTS assay and the cell morphology and growth characterized by SEM and DAPI-actin staining showed similar early behavior. For in vivo biocompatibility, newly formed bone and biodegradability of the experimental scaffolds were evaluated in a subperiosteal cranial rat model using μCT and descriptive histology. The histological analysis has not indicated evidences of inflammation but highlighted close contacts between newly formed bone and the experimental biomaterials revealing an excellent scaffold osseointegration. This study emphasizes the relevance of SLA 3D printing of CaP-based biomaterials for intra-oral bone regeneration even if manufacturing accuracy has to be improved and further experiments using biomimetic scaffolds should be conducted.

Safety of simultaneous versus staged bilateral opening-wedge high tibial osteotomy with locked plate and immediate weight bearing

PURPOSE

With advances in technology and particularly locked screws, patients with high tibial osteotomy (HTO) are frequently allowed full weight bearing for a  unilateral procedure. We are aware of no reports comparing the safety of a simultaneous bilateral HTO with staged bilateral HTO. The purpose of this study was to retrospectively compare these two strategies.

MATERIAL AND METHODS

Ninety patients were treated with bilateral HTO surgery for osteoarthritis from 2009 to 2013; they had opening-wedge HTO and fixed with the same plate fixation and locked screws. A comparison of the outcomes after simultaneous bilateral HTO (35 patients) and after sequential staged bilateral HTO (55 patients) was performed. We considered four measures of medical safety: hypotension, serious intra-operative adverse event, heterologous blood transfusion, and thrombophlebitis. We considered also four measures of orthopaedic safety: infection, patient's inability to walk full weight bearing, changes in correction, and nonunion.

RESULTS

For the same duration of operation, the duration of anaesthesia and the time in the operating room were 35% longer for patients having a staged bilateral HTO. Blood loss was higher in patients undergoing simultaneous bilateral HTO compared with those who underwent a staged bilateral HTO. For patients undergoing simultaneous bilateral HTO, thrombophlebitis frequency and length of anticoagulation were lower than the sum of each event in the staged bilateral HTO. The patients with simultaneous bilateral HTO had a longer total period of time for crutches than patients with staged bilateral HTO. Patients in the simultaneous bilateral cohort did not develop an infection within one year as patients in the planned-stage cohort. The simultaneous bilateral cohort had a lower rate of delayed union than the planned-stage cohort did.

CONCLUSION

On the basis of this analysis, simultaneous bilateral HTO is a reasonable treatment option. Individuals who undergo staged bilateral HTO face the risk of complications twice, in addition to two hospitalizations. Patients who undergo simultaneous bilateral HTO have a higher risk of blood transfusion.

Degenerative Meniscal Tears and High Tibial Osteotomy: Do Current Treatment Algorithms Need to Be Realigned?

Degenerative medial meniscal tears (DMMTs) are a common feature of early knee osteoarthritis (OA). Varus alignment is a strong risk factor for medial compartment knee OA and its progression. We propose that high tibial osteotomy (HTO) should be considered much earlier in the treatment algorithm for patients presenting with recurring medial knee pain, varus alignment, and DMMT, absent of radiographic OA. We provide rationale for investigating HTO as a disease-modifying intervention for secondary prevention in knee OA, and present case examples as low-level proof of principle. Finally, caveats and challenges are discussed along with proposed future research.

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.

Diagnostic Value of Computed Tomography and Risk Factors for Lateral Hinge Fracture in the Open Wedge High Tibial Osteotomy

PURPOSE

The purposes of this study were to evaluate (1) the disparity of detection of lateral hinge fracture (LHF) between postoperative simple radiography and high-resolution computed tomography (CT) and affecting factors of LHF and (2) whether generally recommended postoperative rehabilitation protocols are appropriate according to the type of LHF.

METHODS

From 2014 to 2015, patients who underwent primary open wedge high tibial osteotomy (OWHTO) for isolated medial compartment osteoarthritis of the knee joint were retrospectively enrolled. The patients with minimum 1-year follow-up were included. The incidence of LHF after OWHTO based on simple radiographs was compared with its incidence based on CT scans. In the stable type of LHF and the non-LHF group, early weight bearing was encouraged immediately after OWHTO. In unstable LHF (types II and III), weight bearing was delayed until 2 weeks postoperatively.

RESULTS

Twenty-three cases (24.5%) of LHF after 94 OWHTOs were detected (15 cases on simple radiographs, 8 cases on CT scan). The coronal osteotomy slope and the osteotomy gap were significantly larger in the LHF group than in the non-LHF group (coronal osteotomy slope, 20.3° ± 5.1° vs 16.7° ± 4.2°, P = .001; anterior osteotomy gap, 7.9 mm ± 2.1 mm vs 6.7 mm ± 1.8 mm, P = .008; posterior osteotomy gap, 12.7 mm ± 3.7 mm vs 11.2 mm ± 3.2 mm, P = .048). The correction loss of the hip-knee-ankle angle and the medial proximal tibial angle in the LHF group was significantly larger than those in the non-LHF group (1.3° ± 1.8° vs 0.4° ± 1.4°, P < .001; 1.3° ± 1.1° vs 0.7° ± 0.9°, P = .009, respectively).

CONCLUSIONS

Further evaluation with CT scanning is highly valuable immediately after all OWHTO because of its higher detection rate (24.5%) of LHF compared with simple radiographs (16%). In addition, the coronal osteotomy slope was steeper and the opening gap was larger in the LHF group than in the non-LHF group. Finally, the LHF should be managed conservatively in order to prevent postoperative correction loss.

LEVEL OF EVIDENCE

Level III, case-control study.

Early weight bearing versus delayed weight bearing in medial opening wedge high tibial osteotomy: a randomized controlled trial

PURPOSE

The need for a period of non-weight bearing after medial opening wedge high tibial osteotomy remains controversial. It is hypothesized that immediate weight bearing after medial opening wedge high tibial osteotomy would have no difference in functional scores at one year compared to delayed weight bearing.

METHODS

Fifty patients, median age 54 years (range 40-65), with medial compartment osteoarthritis, underwent a medial opening wedge high tibial osteotomy utilizing a locking plate without bone grafting. Patients were randomized into an Immediate or a Delayed (2 months) weight bearing group. All patients were assessed at one-year follow-up and the two groups compared. The primary outcome measure was the IKS score. Secondary outcome measures included the IKDC score, the VAS pain score and rate of complications.

RESULTS

The functional scores significantly improved in both groups. The IKS score increased from 142 ± 31 to 171 ± 26 in the Immediate group (p < 0.001) and from 148 ± 22 to 178 ± 23 in the Delayed group (p < 0.001). The IKDC score increased from 49 ± 17 pre-operatively to 68 ± 14 one-year post-operatively in the Immediate group (p < 0.0001) and from 44 ± 16 to 69 ± 19 in the Delayed group (p < 0.001). The average VAS for pain 2 months after surgery was 3 ± 3 in the Immediate group and 3 ± 2 in the Delayed (n.s.). There was no significant difference between the two groups in any of the outcome measures. The mean mechanical femorotibial angle changed from 6° of varus (0°-15° of varus, SD = 3°) to 4° of valgus (5°-11° of valgus, SD = 3°) in the Immediate group and from 5° of varus (0°-10° of varus, SD = 3°) to 3° of valgus (2° of varus to 8° of valgus, SD = 3°) in the Delayed group. No difference was seen between groups, and no loss of correction was observed in any patient. Two cases of non-union occurred, one in each group. One infection and one deep vein thrombosis occurred in the Immediate group.

CONCLUSION

Immediate weight bearing after medial opening wedge high tibial osteotomy had no effect on functional scores at 1 year follow-up and did not significantly increase the complication rate. Immediate weight bearing after medial opening wedge high tibial osteotomy appears to be safe and can allow some patients a quicker return to activities of daily living and a decreased convalescence period.

LEVEL OF EVIDENCE

II.

Return to sports and quality of life after high tibial osteotomy in patients under 60 years of age

INTRODUCTION

Since knee osteoarthritis is unicompartmental in most cases, a knee osteotomy is the most logical solution to limit degeneration of the arthritic compartment, thereby delaying knee arthroplasty. Younger patients have high functional demands. The purpose of this study was to evaluate the return to sports and quality of life after high tibial osteotomy (HTO) in athletic patients less than 60 years of age. The hypothesis was that patients can return to sports within 1 year of HTO.

MATERIALS AND METHODS

A single-centre, retrospective study was performed of 30 patients under 60 years of age with medial tibiofemoral osteoarthritis and no history of surgery or trauma who underwent HTO between January 2014 and August 2015. The primary endpoint was the return to sport at 1 year based on the Tegner score. Secondary endpoints were the subjective IKDC score, Lysholm score and SF-36.

RESULTS

The mean follow-up was 1.3 years [1-1.5] and no patients were lost to follow-up. All the patients had returned to sports at 1 year: 73.3% at their pre-surgery level (before the pain started) and 23.3% at a higher level. Their quality of life was significantly improved according to the SF-36 questionnaire: 65.3% pre-operatively compared with 72.5% postoperatively (P=0.01). The preoperative and 1-year postoperative scores were comparable for the Tegner (P=0.167), IKDC (P=0.093) and Lysholm (P=0.061).

CONCLUSION

HTO allows patients to resume their sports activities within 1 year of surgery and significantly improves their quality of life.

LEVEL OF EVIDENCE

Level IV - Retrospective cohort study.

Comparison of fixed-bearing and mobile-bearing total knee arthroplasty after high tibial osteotomy

PURPOSE

There is no information comparing the results of fixed-bearing total knee replacement and mobile-bearing total knee replacement in the same patients previously treated by high tibial osteotomy. The purpose was therefore to compare fixed-bearing and mobile-bearing total knee replacements in patients treated with previous high tibial osteotomy.

METHODS

We compared the results of 57 patients with osteoarthritis who had received a fixed-bearing prosthesis after high tibial osteotomy with the results of 41 matched patients who had received a rotating platform after high tibial osteotomy. The match was made for length of follow-up period. The mean follow-up was 17 years (range, 15-20 years). The patients were assessed clinically and radiographically.

RESULTS

The pre-operative knee scores had no statistically significant differences between the two groups. So was the case with the intra-operative releases, blood loss, thromboembolic complications and infection rates in either group. There was significant improvement in both groups of knees, and no significant difference was observed between the groups (i.e., fixed-bearing and mobile-bearing knees) for the mean Knee Society knee clinical score (95 and 92 points, respectively), or the Knee Society knee functional score (82 and 83 points, respectively) at the latest follow-up. However, the mean post-operative knee motion was higher for the fixed-bearing group (117° versus 110°). In the fixed-bearing group, one knee was revised because of periprosthetic fracture. In the rotating platform mobile-bearing group, one knee was revised because of aseptic loosening of the tibial component. The Kaplan-Meier survivorship for revision at ten years of follow-up was 95.2% for the fixed bearing prosthesis and 91.1% for the rotating platform mobile-bearing prosthesis.

CONCLUSIONS

Although we did manage to detect significant differences mainly in clinical and radiographic results between the two groups, we found no superiority or inferiority of the mobile-bearing total knee prosthesis over the fixed-bearing total knee prosthesis for patients previously operated by high tibial osteotomy.

Effect and safety of early weight-bearing on the outcome after open-wedge high tibial osteotomy: a systematic review and meta-analysis

INTRODUCTION

The purpose of this systematic review and meta-analysis was to evaluate the effectiveness and safety of early weight-bearing by comparing clinical and radiological outcomes between early and traditional delayed weight-bearing after OWHTO.

MATERIALS AND METHODS

A rigorous and systematic approach was used. The methodological quality was also assessed. Results that are possible to be compared in two or more than two articles were presented as forest plots. A 95% confidence interval was calculated for each effect size, and we calculated the I ² statistic, which presents the percentage of total variation attributable to the heterogeneity among studies. The random-effects model was used to calculate the effect size.

RESULTS

Six articles were included in the final analysis. All case groups were composed of early full weight-bearing within 2 weeks. All control groups were composed of late full weight-bearing between 6 weeks and 2 months. Pooled analysis was possible for the improvement in Lysholm score, but there was no statistically significant difference shown between groups. Other clinical results were also similar between groups. Four studies reported mechanical femorotibial angle (mFTA) and this result showed no statistically significant difference between groups in the pooled analysis. Furthermore, early weight-bearing showed more favorable results in some radiologic results (osseointegration and patellar height) and complications (thrombophlebitis and recurrence).

CONCLUSION

Our analysis supports that early full weight-bearing after OWHTO using a locking plate leads to improvement in outcomes and was comparable to the delayed weight-bearing in terms of clinical and radiological outcomes. On the contrary, early weight-bearing was more favorable with respect to some radiologic parameters and complications compared with delayed weight-bearing.

Beta-tricalcium phosphate for orthopedic reconstructions as an alternative to autogenous bone graft

Autogenous bone graft (autograft) remains the gold standard in the treatment of many orthopedic problems. However, graft harvest can lead to perioperative morbidity and increased cost. We tested the hypothesis that an osteoconductive matrix, beta-tricalcium phosphate (β-TCP), would be a safe and effective alternative to autograft alone. Beta-tricalcium phosphate (β-TCP) is considered as one of the most promising biomaterials for bone reconstruction. This study analyzes the outcomes of patients who received β-TCP as bone substitutes in orthopedic surgery.

METHODS

A total of 50 patients were enrolled in a controlled, non-inferiority clinical trial to compare the safety and efficacy of β-TCP (25 patients) with those of autograft (25 patients) in indications requiring usually autograft. These 50 patients were categorized according to the etiology and morphology of the 54 bone defects resulting from elective surgical procedures, such as 34 open-wedge high tibial osteotomies, and 20 osteonecrosis treatments with core decompression. Radiographic (healing process with or without integration of β-TCP), clinical (no other surgical procedure), functional outcomes and safety (with or without complications) were assessed through fifty-two weeks postoperatively.

RESULTS

With regard to the primary endpoint (radiographic evolution), the fusion rate of the 34 open-wedge osteotomies was 100% (17 among 17) for patients in the group with β-TCP compared with 94% (16 among 17) for patients in the autograft group. For the 20 cavitary defects (osteonecrosis), the radiographic union rates, as determined by the presence of osseous bridging, were 100% for patients in the group with β-TCP and 100% for those in the autograft group. Clinically at one year, all quality-of-life and functional outcome data supported non-inferiority of β-TCP compared with autograft, and patients in the β-TCP group were found to have less pain and an improved safety profile.

CONCLUSIONS

Treatment with β-TCP resulted in comparable fusion rates, less pain and fewer side effects as compared with treatment with autograft. This study established clinical parameters where the β-TCP alone can successfully support the osteogenic process.

Locking plate versus non-locking plate in open-wedge high tibial osteotomy: a meta-analysis

PURPOSE

The purpose of this study was to conduct a meta-analysis to determine whether the locking plate or non-locking plate results in better opening-wedge high tibial osteotomy (OWHTO) outcomes.

METHODS

The MEDLINE, EMBASE, COCHRANE, and KOREAMED register databases were searched for studies. The eligibility criteria for inclusion in the review were studies that compared the locking plate with the non-locking plate for OWHTO, and those that provided clear descriptions of surgical techniques and outcomes. The key outcomes of interest were union rate, correction loss angle, correction loss rate, and full weight-bearing starting point. The statistical software "RevMan" was used in statistical analysis.

RESULTS

Five studies were included in the meta-analysis. Among their reported results, there were no differences in the incidence of union [risk ratio (RR) = 1.01, p = 0.34], non-locking plate was associated with lower incidence of correction maintenance (RR = 1.13, p = 0.0006) and greater angle of correction loss [mean difference (MD) = -2.06, p < 0.00001], and locking plate was associated with a significant improvement in Knee society score and function score (MD = 5.77, p < 0.0001; MD = 7.50, p = 0.0005).

CONCLUSIONS

Locking plate provides better clinical outcomes and reduced correction loss rates and angles as compared to non-locking plate for fixation with OWHTO.

LEVEL OF EVIDENCE

IV.

Early full weight-bearing versus 6-week partial weight-bearing after open wedge high tibial osteotomy leads to earlier improvement of the clinical results: a prospective, randomised evaluation

PURPOSE

Open wedge high tibial osteotomy is a widespread treatment option in patients with varus malalignment and medial compartment osteoarthritis. There is no standardised protocol for post-operative rehabilitation available. The purpose of this study was to compare two post-operative rehabilitation protocols and to evaluate the clinical outcome of early full weight-bearing after open wedge HTO.

METHODS

One hundred and twenty consecutive patients with varus malalignment and medial compartment osteoarthritis received an open wedge HTO using an angular locking plate fixation between December 2008 and December 2011. All patients were assigned randomly into one of two groups with different post-operative rehabilitation protocols (11-day vs. 6-week 20-kg partial weight-bearing). Clinical outcome was evaluated using established instruments (Lequesne, Lysholm, HSS and IKDC scores) preoperatively, 6, 12 and 18 months post-operatively. Deformity analysis was performed preoperatively and during follow-up.

RESULTS

All clinical scores showed a significant pre- to post-operative improvement. After 6 months, there was a higher improvement in the group of early full weight-bearing. The difference between preoperative and 6-month follow-up for the group with early full weight-bearing and for the group with 20-kg PWB for 6 weeks was 28 ± 26 and 18 ± 22, respectively, for the Lysholm score and -5.0 ± 5.1 and -3.0 ± 3.6, respectively, for the Lequesne score.

CONCLUSIONS

Early full weight-bearing (11-day 20-kg partial weight-bearing) after open wedge HTO without bone graft leads to earlier improvement of the clinical results and can be recommended for post-operative rehabilitation after open wedge HTO and fixation with an angular locking plate.

LEVEL OF EVIDENCE

Therapeutic study, Level I.

History of internal fixation with plates (part 2): new developments after World War II; compressing plates and locked plates

The first techniques of operative fracture with plates were developed in the 19th century. In fact, at the beginning these methods consisted of an open reduction of the fracture usually followed by a very unstable fixation. As a consequence, the fracture had to be opened with a real risk of (sometimes lethal) infection, and due to unstable fixation, protection with a cast was often necessary. During the period between World Wars I and II, plates for fracture fixation developed with great variety. It became increasingly recognised that, because a fracture of a long bone normally heals with minimal resorption at the bone ends, this may result in slight shortening and collapse, so a very rigid plate might prevent such collapse. However, as a consequence, delayed healing was observed unless the patient was lucky enough to have the plate break. One way of dealing with this was to use a slotted plate in which the screws could move axially, but the really important advance was recognition of the role of compression. After the first description of compression by Danis with a "coapteur", Bagby and Müller with the AO improved the technique of compression. The classic dynamic compression plates from the 1970s were the key to a very rigid fixation, leading to primary bone healing. Nevertheless, the use of strong plates resulted in delayed union and the osteoporosis, cancellous bone, comminution, and/or pathological bone resulted in some failures due to insufficient stability. Finally, new devices represented by locking plates increased the stability, contributing to the principles of a more biological osteosynthesis while giving enough stability to allow immediate full weight bearing in some patients.

Opening-wedge high tibial osteotomy: a seven - to twelve-year study

PURPOSE

medial opening-wedge osteotomy is a widely performed procedure used to treat moderate isolated medial knee osteoarthritis. Historically, the literature has contained reports showing satisfactory mid-term results when accurate patient selection and precise surgical techniques were applied. This study was conducted to investigate the clinical and radiographic seven- to twelve-year results of opening-wedge high tibial osteotomy in a consecutive series of patients affected by varus knee malalignment with isolated medial compartment degenerative joint disease.

METHODS

we reviewed a case series of 147 medial opening-wedge high tibial osteotomies at an average follow-up of 9.5 years. Endpoints for evaluation included the reporting of adverse effects, radiographic evidence of bone union, radiographic changes in the correction angle during union, and clinical and functional final outcomes.

RESULTS

good or excellent results were obtained in 94% of the cases: the patients reported no major complications related to the opening-wedge high tibial osteotomy surgical technique, bone graft resorption, implant choice or postoperative rehabilitation protocol. At final follow-up, the average hip-knee angle was 4° of valgus without major loss of correction during the healing process. A statistically significant change in the patellar height was detected postoperatively, with a trend towards patella infera.

CONCLUSIONS

medial opening-wedge high tibial osteotomy is still a reliable method for correcting varus deformity while producing stable fixation, thus allowing satisfactory stability, adequate bone healing and satisfactory mid- to long-term results.

LEVEL OF EVIDENCE

Level IV, therapeutic cases series.

Prospective evaluation of a new plate fixator for valgus-producing medial open-wedge high tibial osteotomy

PURPOSE

The purpose of this study was to prospectively evaluate the clinical, radiographic, and sports-related outcome at 24 months after valgus-producing medial open-wedge high tibial osteotomy (owHTO) using a 2nd generation peek-carbon composite plate.

METHODS

Between 2010 and 2011, the 2nd generation PEEKPower HTO-Plate(®) was used for medial owHTO in 28 consecutive patients (19 men, 9 women; mean age ± SD: 45 ± 11 years; mean varus deviation ± SD: 4° ± 2°). All of the patients had an osteotomy gap height of ≤12 mm without bone grafting. Visual analog scale (VAS) for pain, WOMAC score, and Lysholm score were evaluated preoperatively and at 12 and 24 months postoperatively. Sports-related outcomes included the Tegner scale, and a self-designed questionnaire preoperatively and 24 months postoperatively. Fixation stability of the implant was evaluated radiographically in two planes by comparing the medial proximal tibial angle (MPTA) and tibial slope 2 days after medial owHTO (baseline measurements) and after implant removal (follow-up measurements). Complications were recorded during the whole study period.

RESULTS

Compared to preoperative conditions, VAS, WOMAC, and Lysholm scores improved significantly (p < 0.05) at the 12- and 24-month follow-up. No significant differences were found between the 12- and 24-month follow-up. After 24 months, the sports frequency increased significantly (p < 0.05). No significant differences between baseline and follow-up measurements for the MPTA and tibial slope were observed. Total complication rate was 4 %, with one patient developing non-union.

CONCLUSION

In the clinical practice, the 2nd generation PEEKPower HTO-Plate(®) is a safe and efficient implant for medial owHTO without bone grafting in patients with an osteotomy gap of ≤12 mm.

LEVEL OF EVIDENCE

III.

Opening wedge high tibial osteotomy: navigation system compared to the conventional technique in a controlled clinical study

PURPOSE

This study aimed to verify if the navigation system used in high tibial osteotomy (HTO) adds precision to the procedure regarding mechanical axis correction and prevention of tibial slope increases.

METHODS

In this historically controlled study, patients with medial osteoarthrosis and genuvarum underwent HTO between 2004 and 2012; the first 20 were operated with the conventional technique, using pre-planning correction by the Dugdale method and 18 further patients were operated with the navigation system introduced in our hospital.

RESULTS

The two groups were similar for pre-operative mechanical axis (mean 8.10 ± 3.14 for the control and 6.60 ± 2.50 for the navigated group), pre-operative tibial slope (mean 8.95 ± 3.47 versus 8.17 ± 3.11, respectively) and Lyshom score (40.85 ± 15.46 and 44.83 ± 16.86). After surgery, the control group presented mean mechanical axis of 3.35 ± 3.27, tibial slope of 13.75 ± 3.75 and Lyshom score of 87.60 ± 11.12. The navigated group showed a postoperative mechanical axis mean of 3.06 ± 1.70, tibial slope of 10.11 ± 0.18 and Lyshom score of 91.94 ± 11.61.

CONCLUSIONS

The navigation system allowed a significantly better control of tibial slope. Patients operated with the navigation system had significantly better Lysholm scores.