High tibial valgus osteotomy in unicompartmental medial osteoarthritis of the knee: a retrospective follow-up study over 13-21 years

Mid-term patient-reported outcomes are inferior in opening-wedge high tibial osteotomy patients with untreated medial meniscus posterior root tear

Purpose

The impact of untreated medial meniscus posterior root (MMPR) tear (MMPRT) during opening-wedge high tibial osteotomy (OWHTO) on patient-reported outcomes (PROs) remains poorly understood. This retrospective cohort study aimed to investigate the association between the presence of MMPRT and post-operative PROs in patients who underwent OWHTO.

Methods

A total of 83 knees that underwent OWHTO that were followed up for 6.6 years were included. Post-operative PROs were assessed using the knee injury and osteoarthritis outcome score (KOOS) subscales. Medial meniscus extrusion (MME) was measured by magnetic resonance imaging (MRI). MMPRT was diagnosed based on preoperative MRI and intraoperative arthroscopy findings. The participants were categorized into the MMPRT and MMPR intact (MMPRI) groups, and their KOOS subscales were compared. Additionally, logistic regression analysis was conducted to explore the correlation between KOOS and MMPRT presence.

Results

In total, 29 out of 80 (36.3%) knees were classified into the MMPRT group, while three knees underwent total knee arthroplasty. Preoperative MME was 3.5 ± 1.9 (range 0-8.9) mm, showing correlation with the presence of MMPRT (p = 0.004) by regression analysis. The post-operative KOOS subscales of the MMPRT group were lower than the MMPRI group for pain (p = 0.017), activities of daily living (ADLs) (p = 0.001), sports (p < 0.001) and quality of life (QOL) (p < 0.001). Additionally, regression analysis showed the presence of MMPRT was correlated with lower KOOS subscale scores for pain (p = 0.041), ADLs (p = 0.011), sports (p < 0.001) and QOL (p = 0.002).

Conclusion

Preoperative MMPRT correlated with a reduction in mid-term post-operative PROs, as assessed using the KOOS, among patients who underwent OWHTO. Surgeons should consider addressing an MMPRT at the time of OWHTO.

Level of Evidence

Level IV.

Lateral closing wedge high-tibial osteotomy is a long-lasting option for patients under the age of 55 with medial compartment osteoarthritis

Purpose

Assess the survival of the closing wedge high tibial osteotomy (CWHTO) with failure defined as progression to total knee arthroplasty (TKA) and perioperative complications.

Methods

Patients undergoing CWHTO in a single centre were included in this study. The patient's demographics, operative data and patient-reported outcome measures were collected from the medical records. The outcomes assessed were progression to TKA, complications and patient-reported outcome measures. The Australian joint registry was used to assess which patients progressed to TKA. A binary logistics regression is used to determine if any of the collected factors increase the likelihood of conversion to arthroplasty. Survival analysis is conducted using a Kaplan-Meier survivorship analysis with failure defined as progression to TKA.

Results

Three hundred and fifty-four (244 males and 110 females) patients were included in the study. The average age of the group was 51 years with an average follow-up of 18 years. Patients under the age of 55 had a lower rate of progression to TKA. At 15 years, the rate of progression to TKA was 64% and 85% for those under the age of 55 and over 55, respectively. The complication rate was 6% without any peroneal nerve palsies.

Conclusion

CWHTO is a good surgical option particularly when indicated in patients under the age of 55. Additionally, this technique results in a low overall complication rate with an absence of the often-feared complication of peroneal nerve palsy.

Level of Evidence

Level III, Retrospective study.

Mathematical explanations for knee osteotomies: "Dear engineer, how would you explain it in a simple way?"

INTRODUCTION

Knee osteotomies are effective procedures to treat different deformities and to redistribute the load at the joint level, reducing the risk of wear and, consequently, the need for invasive procedures. Particularly, knee osteotomies are effective in treating early arthritis related to knee deformities in young and active patients with high functional demands, with excellent long-term results. Precise mathematical calculations are imperative during the preoperative phase to achieve tailored and accurate corrections for each patient and avoid complications, but sometimes those formulas are challenging to comprehend and apply.

METHODS

Four specific questions regarding controversial topics (planning methods, patellar height, tibial slope, and limb length variation) were formulated. An electronic search was performed on PubMed and Cochrane Library to find articles containing detailed mathematical or trigonometrical explanations. A team of orthopedic surgeons and an engineer summarized the available Literature and mathematical rules, with a final clear mathematical explanation given by the engineer. Wherever the explanation was not available in Literature, it was postulated by the same engineer.

RESULTS

After the exclusion process, five studies were analyzed. For three questions, no studies were found that provided mathematical analyses or explanations. Through independent calculations, it was demonstrated why Dugdale's method underestimates the correction angle compared to Miniaci's method, and it was shown that the variation in patellar height after osteotomy can be predicted using simple formulas. The five included studies examine postoperative variations in limb length and tibial slope, providing formulas applicable in preoperative planning. New formulas were independently computed, using the planned correction angle and preoperatively obtained measurements to predict the studied variations.

CONCLUSIONS

There is a strict connection among surgery, planning, and mathematics formulas in knee osteotomies. The aim of this study was to analyze the current literature and provide mathematical and trigonometric explanations to important controversial topics in knee osteotomies. Simple and easy applicable formulas are provided to enhance the accuracy and outcomes of this surgical procedure.

Medial Gradual Opening Osteotomy of the Tibia With Monolateral External Fixator for Correcting the Varus Deformity of the Tibia

Correction of the varus deformities in the tibia is necessary because of the excessive pressure exerted on the medial compartment of the knee, which intensifies the degenerative process. Correction strategies encompass a variety of approaches and depend on the patient's individual characteristics, age, soft tissue condition, and the orthopaedic surgeon's experience with different surgical materials. Size and location of the deformity, whether gradual or acute, play crucial roles in choosing the most appropriate material and shape. The gradual correction is especially indicated for patients with severe deformities, soft tissue involvement, and a history of bone infections. This study aimed to introduce a gradual correction technique for varus deformities in the tibia using a unilateral external fixator and to describe the postoperative follow-up. This technique offers notable advantages, including accurate correction, better patient acceptance, lighter assembly, less risk of pseudarthrosis, and shorter distraction process owing to the use of a single piece. In addition, the operated limb can support the load on the day after surgery, and dynamic follow-up is performed on an outpatient basis.

Open-wedge high tibial osteotomy with and without bone void filler: Allograft leads to faster bone union and weight bearing with comparable return to work and sports rates

PURPOSE

To compare the clinical and radiological outcome of open-wedge high tibial osteotomy (OWHTO) with allogenous bone chips to a control group without bone void filler. The focus was on the rates and timelines of return to work (RTW) and return to sports (RTS), given the significance of these factors for the satisfaction of young and active patients.

METHODS

One hundred and ninety-five cases of OWHTO (112 cases with allograft vs. 83 cases without graft) with a follow-up of 17 ± 4.8 months were included in this retrospective analysis. Various metrics were investigated, including time to return to full weight bearing, RTW and RTS rates and timelines, International Knee Documentation Committee (IKDC) Score, Cincinnati-Sportsmedicine and Orthopaedic Centre Score and Tegner Score. The time to bone union was determined on radiographs taken at 6, 16, 28 and 53 weeks.

RESULTS

Patients returned to full weight bearing after 8.8 ± 4.8 weeks. RTW was possible for 92.8% after 13.7 ± 12.3 weeks. 96.2% returned to sports after 22.7 ± 8.3 weeks, but the number of disciplines and workouts per week diminished (p < 0.001, p = 0.006). A shift to low-impact and recreational sports was observed. Patients with allograft filling had earlier bone union (21 ± 12.3 vs. 31.9 ± 14.2 weeks, p < 0.001) and returned faster to full weight bearing (8.2 ± 4.5 vs. 9.8 ± 5 weeks, p = 0.013). There was no difference between groups in the IKDC Score (69 ± 17.2 vs. 69.9 ± 15.2, p = 0.834), Cincinnati-Sportsmedicine and Orthopaedic Centre Score (68 ± 18.3 vs. 69.4 ± 18.2, p = 0.698) and Tegner Score (3.8 ± 1.5 vs. 4 ± 1.5, p = 0.246).

CONCLUSION

Allograft filling leads to faster bone union and return to full weight bearing but showed no significant advantage in terms of RTW/RTS, overall patient satisfaction and functional scores. The decision for or against filling the osteotomy gap, therefore, remains a case-by-case decision.

LEVEL OF EVIDENCE

Level III, Retrospective cohort study.

Intraoperative radiographic analysis and adjustment of the optimal position of plate in high tibial osteotomy

BACKGROUND

When high tibial osteotomy is performed for genu varus deformity, it is not easy to determine the accurate placement of the plate.

PURPOSE

To determine a simple way to assess the position of the plate, to provide more effective mechanical support and to reduce the risk of implant rupture and vascular injury.

MATERIAL AND METHODS

Two human anatomical marks, the patellar ligament and semimembranosus, were connected and divided into four parts to identify points Ⅰ, Ⅱ, and Ⅲ. These points determined the areas for Tomofix placement: anterior, anterolateral, and lateral. Simulated internal fixation placed hole B of Tomofix at points Ⅰ (anterior), Ⅱ (anterolateral), and Ⅲ (lateral). We analyzed the pointing direction of the locking screws in Tomofix holes on MRI to assess potential injury risk to the popliteal neurovascular bundle.

RESULTS

In the X-ray: holes B and C appeared as the plate in the anterior, only hole C appeared as the plate in the anterolateral, and none of the holes appeared as the plate in the lateral. In the general view of the sawbones, the screw pointed towards the popliteal neurovascular bundle when the plate was in the anterior.

CONCLUSION

If a small number of holes on the plate is visible under fluoroscopy, then several lateral positions of the plate can be obtained; the direction of the screw tunnel tends to deviate from the popliteal neurovascular bundle with the posterior position of the plate.

Validation of a Three-Dimensional Weight-Bearing Measurement Protocol for Medial Open-Wedge High Tibial Osteotomy

Three-dimensional (3D) deformity assessment and leg realignment planning is emerging. The aim of this study was to (1) validate a novel 3D planning modality that incorporates the weight-bearing (WB) state (3D WB) by comparing it to existing modalities (3D non-weight-bearing (NWB), 2D WB) and (2) evaluate the influence of the modality (2D vs. 3D) and the WB condition on the measurements. Three different planning and deformity measurement protocols were analyzed in 19 legs that underwent medial open-wedge high tibial osteotomy (HTO): (1) a 3D WB protocol, after 2D/3D registration of 3D CT models onto the long-leg radiograph (LLR) (3D WB), (2) a 3D NWB protocol based on the 3D surface models obtained in the supine position (3D NWB), and (3) a 2D WB protocol based on the LLR (2D WB). The hip-knee-ankle angle (HKA), joint line convergence angle (JLCA), and the achieved surgical correction were measured for each modality and patient. All the measurement protocols demonstrated excellent intermodal agreement for the achieved surgical correction, with an ICC of 0.90 (95% CI: 0.76-0.96)) (p < 0.001). Surgical correction had a higher mean absolute difference compared to the 3D opening angle (OA) when measured with the WB protocols (3D WB: 2.7 ± 1.8°, 3D NWB: 1.9 ± 1.3°, 2D WB: 2.2 ± 1.3°), but it did not show statistical significance. The novel planning modality (3D WB) demonstrated excellent agreement when measuring the surgical correction after HTO compared to existing modalities.

Does preoperative bone marrow edema affect clinical outcomes after medial open-wedge high tibial osteotomy?

PURPOSE

The aim of this study is to evaluate the results of high tibial osteotomy (HTO) in patients with bone marrow edema (BME) and assess the effect of factors on the subsequent results.

METHODS

A total of 138 patients who underwent medial open-wedge HTO using locking plate were included in this study. BME was observed in 108 patients using preoperative magnetic resonance imaging. Clinical results were evaluated before HTO and postoperatively at 12 months. Moreover, we evaluated the factors affecting the clinical results.

RESULTS

The clinical scores were all significantly improved regardless of the presence of BME. There were no differences in improvement of clinical scores between patients with BME and without BME. Patients with BME showed higher postoperative Western Ontario and McMaster Universities Arthritis Index (WOMAC) stiffness scores than patients without BME. Furthermore, patients with BME on both the femur and tibia showed lower Knee Society function scores than patients with BME on either the femur or the tibia. Patients with large BME lesions exhibited a lower Hospital for Special Surgery score and WOMAC pain scores, postoperatively. In patients with BME, patients with undercorrection showed significantly lower improvement in WOMAC pain scores compared with patients with acceptable correction.

CONCLUSIONS

The clinical improvement after HTO in patients with varus and medial osteoarthritis was not different regardless of the presence or absence of BME. However, accurate alignment should be considered essential for achieving better clinical outcomes in patients with preoperative BME.

Cartilage degeneration of patellofemoral joint occurs in open wedge high tibial osteotomy, rather than in hybrid closed wedge high tibial osteotomy, during the early postoperative period: A qualitative analysis using MRI T2 mapping

PURPOSE

After high tibial osteotomy, the patella may change position and osteoarthritis of the patellofemoral joint (PFJ) may occur. It was hypothesized that the course of PFJ degeneration would differ between open wedge high tibial osteotomy (OWHTO) and hybrid closed wedge high tibial osteotomy (hybrid HTO). Accordingly, this study aimed to evaluate the qualitative changes in PFJ articular cartilage, during the early postoperative period after OWHTO and hybrid HTO.

METHODS

This was a retrospective observational study of 75 knees that underwent OWHTO (N = 37) or hybrid HTO (N = 38) for medial knee osteoarthritis. OWHTO and hybrid HTO were indicated for corrections of less than 10° and more than 10°, respectively. MRI of all knees was performed before and 6 months after surgery to evaluate patellar cartilage in sagittal images for T2 mapping. Three regions of interest (medial, middle, and lateral facets) were defined in the articular cartilage, and T2 values were measured. Patellar tilting angle, lateral shift ratio, and patellar height were compared before and after surgery.

RESULTS

There was no significant change in arthroscopic findings of PFJ articular cartilage between the OWHTO and hybrid HTO groups. In the OWHTO group, the mean T₂ value of medial and middle facets increased significantly (lateral, 43.0 ± 3.9 to 43.7 ± 3.5; middle, 44.2 ± 3.9 to 46.2 ± 3.8; medial 41.0 ± 4.3 to 42.4 ± 4.0). Conversely, no significant change was observed in the hybrid HTO group (lateral, 41.1 ± 4.0 to 42.3 ± 4.0; middle, 43.6 ± 4.2 to 44.5 ± 4.3; medial, 40.7 ± 4.1 to 41.5 ± 4.5). Patellar height decreased and increased in the OWHTO and hybrid HTO groups, respectively, and patellar tilt decreased in the OWHTO group. Lateral shift ratio decreased significantly in both groups.

CONCLUSIONS

OWHTO with a small correction angle may result in qualitative changes in PFJ articular cartilage from an early stage, while hybrid HTO with a relatively large correction angle is unlikely to affect PFJ articular cartilage.

Influence of hindfoot alignment on postoperative lower limb alignment in medial opening wedge high tibial osteotomy

INTRODUCTION

We have experienced unexpected under-correction after medial opening wedge high tibial osteotomy (MOWHTO). Although the tibia was corrected accurately, the postoperative mechanical axis (MA) was less than 57%. The purpose of this study was to evaluate the relationship between hindfoot alignment and postoperative lower limb alignment, and to reveal whether hindfoot alignment affects lower limb alignment after MOWHTO. Our hypothesis was that hindfoot alignment influences the postoperative MA in MOWHTO.

MATERIALS AND METHODS

This study was a retrospective comparative study. The study cohort comprised 43 knees in 43 patients who underwent MOWHTO and had standing long-leg anteroposterior view and hindfoot alignment view radiographs taken preoperatively and at 3 months postoperatively. To evaluate the hindfoot alignment, the absolute value of the ankle joint line orientation relative to the ground was added to the absolute value of the hindfoot angle. We defined a postoperative MA of 57-67% as acceptable correction (A group) and a MA of < 56% as under-correction (U group). The two groups were analyzed to identify factors that affected postoperative limb alignment.

RESULTS

The preoperative hindfoot alignment angle was significantly larger in the U group than the A group. The preoperative hindfoot alignment angle was a significant predictive factor of the postoperative MA, and the cut-off value that distinguished under-correction from acceptable correction was 15.9 degrees.

CONCLUSION

Abnormal hindfoot alignment is one of the causes of under-correction after MOWHTO. Attention should be paid to the preoperative ankle joint line orientation relative to the ground and hindfoot angle. If the preoperative hindfoot alignment angle is ≥ 15.9 degrees, surgeons should reconsider the operative procedure and correction angle.

LEVEL OF EVIDENCE

Therapeutic level III, retrospective study.

Impact of the Weightbearing Line on Cartilage Regeneration of the Medial Knee Compartment after Open-Wedge High Tibial Osteotomy, Based on Second-Look Arthroscopy

OBJECTIVE

Cartilage regeneration is multifactorial. This study aimed to optimize the biomechanical factor of weightbearing loading allowing for cartilage regeneration and elucidate the association between cartilage regeneration and clinical outcomes after medial open-wedge high tibial osteotomy (OWHTO).

DESIGN

This was a retrospective, observational study of 142 patients who underwent OWHTO and subsequently underwent second-look arthroscopic assessment at a single orthopedic surgery center in Japan. Clinical and radiographic outcomes were compared between patients with (group R) and without (group D) cartilage regeneration, measured using the International Cartilage Repair Society grading system and the macroscopic staging system at the time second-look arthroscopy was performed. A receiver operating characteristic curve analysis was used to determine the optimal weightbearing line ratio (WBLR) for cartilage regeneration.

RESULTS

Group R included 82 knees, and group D 60 knees. The WBLR was higher in group R (60.9% ± 6.7%) than in group D (55.6% ± 7.6%) (P < 0.001) and was associated with a greater improvement in clinical outcomes, namely the Lysholm scale score and all subscales of the Knee Injury and Osteoarthritis Outcome Score (P < 0.01). The WBLR predicted cartilage regeneration with an odds ratio of 1.11 (P = 0.001) and an area under the curve of 0.718, for a WBLR value of 62%.

CONCLUSIONS

A WBLR of 62% was associated with cartilage regeneration after OWHTO and high patient-reported clinical outcomes.

Effect of the sagittal osteotomy inclination angle on the posterior tibial slope change in high tibial osteotomy: three-dimensional simulation study

In performing medial open-wedge high tibial osteotomy, it is recommended not to alter the posterior tibial slope. However, it remains unclear whether the osteotomy inclination angle affects the posterior tibial slope in the sagittal plane. This study aimed to verify how anterior or posterior osteotomy inclination angle affects the tendency of change in the posterior tibial slope and to conduct quantitative analysis of the extent to which the posterior tibial slope changes according to the degree of the osteotomy inclination angle change in MOWHTO. Computed tomography images of 30 patients who underwent MOWHTO were collected. Three-dimensional models of preoperative original tibia were reconstructed, and virtual osteotomies were performed. The sagittal osteotomy inclination angles formed by the osteotomy line and the medial tibial plateau line were classified as positive in case of anteriorly inclined osteotomy and negative in case of posteriorly inclined osteotomy. Thirteen osteotomies were performed for each tibial model at intervals of 5° from - 30° to 30°. The posterior tibial slope was assessed, and the proportional relationship between the sagittal osteotomy inclination angle and the posterior tibial slope change was analyzed. The posterior tibial slope changed significantly after osteotomy (p < 0.001), except for the cases where the sagittal osteotomy inclination angles were 5°, 0°, and - 5°. Anteriorly and posteriorly inclined osteotomy caused increase and decrease in the posterior tibial slope, respectively. As the inclination angle increased by 1°, the posterior tibial slope increased by 0.079° in anterior inclination osteotomy, while in posterior inclination osteotomy, as the inclination angle decreased by 1°, the posterior tibial slope decreased by 0.067°. The osteotomy inclination angle in the sagittal plane significantly affected the posterior tibial slope. When there was an inclination angle occurred between the osteotomy line and the medial tibial plateau line in the sagittal plane, the posterior tibial slope changed after MOWHTO. The posterior tibial slope tended to increase in anteriorly inclined osteotomy and decrease in posteriorly inclined osteotomy. The change in the posterior tibial slope was proportionally related to the absolute value of the osteotomy inclination angle.

Clinical outcomes of hybrid closed wedge high tibial osteotomy for advanced osteoarthritis of the knee compared with total knee arthroplasty

PURPOSE

To evaluate clinical outcomes between hybrid closed wedge high tibial osteotomy (HCWHTO) and total knee arthroplasty (TKA) for advanced medial compartmental osteoarthritis of the knee (advanced knee OA).

METHODS

In more than grade 3 OA based on the Kellgren-Lawrence classification, when patients' age was less than 60 years or activity level was more than level 5 based on the UCLA activity score, 22 knees (18 patients) underwent HCWHTO. The other 22 knees (18 patients) that underwent TKA were evaluated retrospectively. Muscle strength was evaluated preoperatively and at 1 year postoperatively. The visual analogue scale (VAS) and Japanese version of the Knee injury and Osteoarthritis Outcome Score (J-KOOS) were used to evaluate clinical outcomes preoperatively and at a mean 66-months follow-up.

RESULTS

All postoperative muscle strength measures improved to preoperative equivalent levels in the HCWHTO group; they were significantly higher in the HCWHTO group than in the TKA group (p < .05). The VAS score and total J-KOOS significantly improved in both groups (HCWHTO, p = .001; TKA, p = .040); there were no significant differences in the scores between the groups at the final follow-up. Hybrid closed wedge HTO significantly improved the activities of daily living and sport/recreation scores, whereas TKA did not at the final follow-up.

CONCLUSIONS

In advanced knee OA, HCWHTO led to improved muscle strength, and its midterm clinical outcomes were equivalent to those of TKA. To postpone or even to avoid TKA, HCWHTO is considered an appropriate treatment for young and high-activity patients with advanced knee OA.

LEVEL OF EVIDENCE

Therapeutic Level III.

Patellofemoral Joint after Opening Wedge High Tibial Osteotomy: A Comparative Study of Uniplane versus Biplane Osteotomies

OBJECTIVE

To the best of our knowledge, there has been no comparative study of changes in radiographic parameters in the sagittal plane between biplane opening wedge high tibial osteotomy (OWHTO) with plate fixation and uniplane OWHTO with spacer implantation. The aim of the study was to compare sagittal radiographs between the procedures of biplane and uniplane OWHTOs in patients with genu varum and to investigate the impact on the patellofemoral joint.

METHODS

A retrospective study of 71 patients (58.0 ± 5.0 years of age, 58 females and 13 males) with varus-aligned medial compartment knee osteoarthritis treated with OWHTO was performed during the period from January 2016 to February 2019. Thirty-three patients underwent biplane osteotomy with plate fixation (biplane group), and 38 patients underwent uniplane osteotomy with absorbable wedged spacer fixation (uniplane group). Independent t tests were used to compare the two groups according to the preoperative and postoperative radiographic parameters of hip-knee-ankle (HKA) angle, posterior tibial slope (PTS), tibial tubercle prominence (TTP), Caton-Deschamps (CD) index, and Blackburne-Peel (BP) index. During the last follow-up assessment, patients were asked to rate their patellofemoral joint status using the Samsung Medical Center (SMC) patellofemoral (PF) scoring system. The visual analog scale (VAS) was also used to rate knee joint pain when walking.

RESULTS

There was no significant difference between the two groups in any of the demographic, clinical, or radiological characteristics at baseline (p > 0.05). Comparisons of postoperative sagittal radiographic parameters between patients in the uniplane group and patients in the biplane group showed significant differences in the PTS (13.4° vs 16.6°, t = 4.465, p < 0.001), TTP (9.0 mm vs 4.2 mm, t = 7.950, p < 0.001), and CD index (0.81 vs 0.70, t = 4.035, p < 0.001). At the final follow-up assessment (minimum, 2 years), the SMC PF function score was significantly lower in patients in the uniplane group than in patients in the biplane group (27.8 vs. 32.1, t = 2.458, p = 0.016), but there were no significant differences in the SMC PF pain score or VAS score (p > 0.05).

CONCLUSION

The essential difference in the postoperative sagittal radiographic changes between biplane and uniplane OWHTO was the tibial tubercle prominence, indicating the posterior displacement of the tibial tubercle. Uniplane OWHTO may yield better function of the patellofemoral joint compared to biplane OWHTO.

Less risk of conversion to total knee arthroplasty without significant clinical and survivorship difference for opening-wedge high tibial osteotomies in varus knee deformities at 10-year minimum follow-up compared to closing-wedge high tibial osteotomies

PURPOSE

The purpose of this study was to evaluate the clinical outcomes and survivorship at minimum 10-year follow-up of patients undergoing primary valgisation high tibial osteotomy (HTO) for medial osteoarthritis (OA), treated by Opening-Wedge HTO (OW-HTO) or Closing-Wedge HTO (CW-HTO).

METHODS

This was a retrospective cohort study of consecutive patients presenting to a single institution undergoing HTO for isolated medial compartment OA. Two hundred and twenty three HTOs for isolated medial tibio-femoral OA were performed between January 2002 and December 2010. Patients were eligible if they had minimum 10-year follow-up and received either a CW or OW-HTO. Fifteen (6.7%) patients died and twenty-five (11.2%) were lost to follow-up. One hundred and eighty three (82.1%) patients were included in the final analysis and divided into two groups: OW-HTO (96/183; 52.4%) and CW-HTO (87/183; 47.6%). Range of motion, KSS, KOOS scores, and conversion to TKA rate were analyzed between groups. Both groups were comparable regarding age, arthrosis stage, gender, ASA score and BMI at the time of HTO. Survival analysis was conducted with re-intervention for TKA as the end point.

RESULTS

At the time of HTO, mean age was 55 years ± 7.9 (27-73.9) with 72.7% of patients being male. The mean follow-up was 13.3 years ± 2.7 (10-19). Sixty-four (34.9%) patients underwent TKA at a mean delay of 9.3 years ± 3 (3-16). The conversion to TKA rate was significantly higher in the CW-HTO group versus the OW-HTO group: 42.5% (37/87) versus 28.1% (27/96) (p = 0.04). The survival at 15-year follow-up was 59.2% in the OW-HTO group versus 54.6% in the CW-HTO group (n.s.). At 13-year follow-up, KSS Function score was significantly better in the OW-HTO (90.9 versus 82.4; p = 0.007). No significant difference was observed between the two groups regarding the KOOS score, KSS Knee Score and complication rate.

CONCLUSION

At mean follow-up of 13 years, no significant clinical and survivorship difference was observed between the two groups. The conversion to TKA was significantly lower following OW-HTO. Minor correction was associated with risk of requiring subsequent TKA.

LEVEL OF EVIDENCE

Retrospective case series, IV.

Factors Associated with Postoperative Knee Joint Line Obliquity After Medial Open Wedge High Tibial Osteotomy

BACKGROUND

There are still few reports on factors associated with postoperative knee joint line obliquity (KJLO).

PURPOSE

The purpose was to determine preoperative radiographic factors that are associated with KJLO postoperatively after open wedge high tibial osteotomy (OWHTO) using multivariable linear regression analysis and multivariable logistic regression analysis.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

A total of 60 patients with 65 varus knees who underwent OWHTO between December 2012 and June 2018 at a single institution were retrospectively enrolled in this study. The authors evaluated radiologic parameters including the weightbearing line ratio, femorotibial angle, medial proximal tibial angle, mechanical lateral distal femoral angle (LDFA), lateral distal tibial angle, joint line convergence angle (JLCA), KJLO, and ankle joint obliquity. They also categorized these radiographic parameters as preoperative and postoperative and calculated the difference (Δ) between preoperative and postoperative values. To determine which of the radiographic parameters were most associated with postoperative KJLO, multivariable linear regression analysis was performed using the stepwise method. Multivariable logistic regression analysis was used to examine the relative contribution of the preoperative radiographic parameters to an abnormal postoperative KJLO (>4°).

RESULTS

In the multivariable linear regression analysis, the preoperative LDFA and JLCA showed a statistically significant correlation. Multivariable logistic regression analysis revealed that the mean preoperative LDFA was significantly larger in the group with abnormal KJLO than in the group with the control group (odds ratio, 1.84; 95% CI, 1.12-3.02; P = .02), while preoperative JLCA tended to be larger in the abnormal KJLO group than the control group but not statistically significantly different.

CONCLUSION

KJLO after OWHTO was associated with preoperative LDFA and JLCA in multivariable linear regression analysis, and preoperative LDFA was the most important factor associated with abnormal KJLO after OWHTO in multivariable logistic regression analysis.

10-Year Survival Rates After High Tibial Osteotomy Using Angular Stable Internal Plate Fixation: Case Series With Subgroup Analysis of Outcomes After Combined Autologous Chondrocyte Implantation and High Tibial Osteotomy

Background:

Good-to-excellent midterm results after high tibial osteotomy (HTO) to treat medial compartment cartilage defects or osteoarthritis (OA) have been published, but little is known about long-term survival rates in terms of conversion to total knee arthroplasty (TKA) using angular stable internal plate fixation.

Purpose:

To determine TKA-free survival rates and functional and radiological outcomes at 10 years after HTO. A subgroup analysis of patients who underwent combined HTO and autologous cartilage implantation (ACI) was also performed.

Study Design:

Case series; Level of evidence, 4.

Methods:

Included were 125 patients with a mean follow-up of 9.90 ± 2.25 years; 90 patients underwent HTO for medial OA, and 35 patients underwent ACI and HTO for medial focal cartilage defects. Functional outcome measures included visual analog scale (VAS) for pain, Lysholm, International Knee Documentation Committee (IKDC), and Knee injury and Osteoarthritis Outcome Score (KOOS) subscales and KOOS₄ (average of 4 KOOS subscales: Pain, Symptoms, Sport, and Quality of Life). Radiological outcomes included lateral distal femoral angle, medial proximal tibial angle, and joint line convergence angle.

Results:

Overall, 16 patients required conversion to TKA at a mean 86.75 ± 25.73 months (10-year survival rate, 87.2%). Only 2 patients in the HTO+ACI subgroup required a conversion to TKA (10-year survival rate, 94.3%). The complication rate for all patients was 8.8%. In both the HTO and HTO+ACI subgroups, VAS pain levels decreased and Lysholm scores increased significantly from pre- to postoperatively (P < .001). A higher preoperative Tegner score led to a significantly lower risk for conversion to TKA (P = .001), and a preoperative body mass index of ≥35 was associated with a significantly higher risk (P = .019), as was female sex (P = .046). Radiological parameters remained within physiological ranges. The postoperative joint line conversion angle did correlate with postoperative functional outcome but not with TKA conversion.

Conclusion:

Long-term results of HTO for medial compartment OA or cartilage defects with underlying varus deformity were good to excellent. In particular, patients who underwent HTO+ACI presented excellent long-term survival rates. HTO, therefore, delays or prevents TKA implantation, especially in young, active patients with medial compartment damage.

CAS and PSI increase coronal alignment accuracy and reduce outliers when compared to traditional technique of medial open wedge high tibial osteotomy: a meta-analysis

PURPOSE

Medial open-wedge high tibial osteotomy (MOWHTO) is an accepted option in the treatment of medial compartment osteoarthritis of the knee in young and active patients. Functional results are closely correlated to the correction of the mechanical axis of the lower limb. Although several angular and geometrical methods and values have been proposed in the past, the ideal target is still debated. In addition, it is important to have a deep correlation between the planned correction and the achieved correction after surgery. The aim of the present systematic review was to identify the ideal coronal correction after MOWHTO and the most accurate method to achieve it.

METHODS

A systematic review of the literature was completed on July 3rd 2020 in the Pubmed, Medline, Cochrane Reviews, and Google Scholar databases using the Medical Subject Headings (MeSH) terms: "high tibial osteotomy" AND "accuracy" OR "planning".

RESULTS

28 studies were included; 18 were focused on computer-assisted surgery (CAS) and 10 on patient-specific instrumentation (PSI). There were 598 patients in the CAS group and 501 in the control group; the rate of outliers was 16% and 38.2% respectively (P = 0.04), while there was no significant difference between the two groups (SMD = - 0.10; 95% CI 1.31 to 1.12; P = n.s.) in terms of coronal accuracy. Likewise, there were 318 patients in the PSI group and 40 in the control group; the rate of outliers was 15% and 40% respectively (P = 0.98), while there was no significant difference between the two groups (SMD = 0.01; 95% CI 0.58 to 0.59; P = 0.98).

CONCLUSIONS

A statistically significant reduced outlier rate and a non-significant increased accuracy emerged with the use of CAS when compared to the traditional surgical technique, whereas the results of PSI were still inconclusive. In addition, it emerged clearly that no consensus still exists on the ideal correction target to be achieved after surgery.

LEVEL OF EVIDENCE

III.

Older age increases the risk of revision and perioperative complications after high tibial osteotomy for unicompartmental knee osteoarthritis

Among various patient risk factors affecting survival after high tibial osteotomy (HTO), the ideal age limit for HTO is unclear. This study was performed to evaluate the effect of age on survival rate and complications after HTO for medial unicompartmental osteoarthritis. Among of 61,145 HTO patients from Korean National Health Insurance database, 41,112 patients underwent the procedure before the age of 60 years (Group A), 13,895 patients between the age of 60 and 65 years (Group B), and 6138 patients after the age of 65 years (Group C). We compared the survival rate in person-years among the three groups from the date of primary surgery until subsequent total knee arthroplasty. Perioperative complications were also recorded. The adjusted hazard ratio (HR) were calculated using the multivariable Cox proportional hazard regression model, adjusting for the potential confounders: age, sex, type of medical insurance, region of residence, hospital type, comorbidities, and Charlson comorbidity index score. The total number of HTO increased 6.5-fold, especially in patients aged > 65 years (by 8.2-fold) from 2008 to 2018. The overall revision rate was 4.2% in Group A, 6.4% in Group B, and 7.3% in Group C. The 5- and 10-year revision rate was significantly lower in Group A (p < 0.001), but no difference between Groups B and C. After adjusting for potential confounders, multivariable regression analysis revealed that revision rate was significantly lower in Group A than Group B (HR: 0.57; p < 0.0001), but no difference between Groups B and C. The incidence of complications was also significantly lower in Group A than in other groups. The inferior survival rate and more perioperative complications after HTO was found in old patients (aged ≥ 60 years) than in young patients. Therefore, the patient age is one of the predicting factors for a high risk of failure after HTO.

A novel biplanar medial opening-wedge high tibial osteotomy: the Z-shaped technique. A case series at 7.2 years follow-up

Background

High tibial osteotomy (HTO) provides reliable and good long-term results, if performed with correct indications, but different techniques and types of fixation have been described. The purpose of this study is to present a novel modified biplanar medial opening-wedge (MOW) HTO technique where the osteotomies are performed in a Z-shaped fashion, and to present the medium-term clinical and radiographic results.

Materials and methods

We present a case series of 75 patients (80 knees) with mean age of 45.8 years, affected by isolated medial knee osteoarthritis and symptomatic varus knee malalignment, who underwent novel biplanar Z-shaped MOWHTO. Clinical and radiological outcomes were collected, retrospectively before surgery and at median follow-up of 7.2 years (95% CI 5.6–9.2 months) after surgery. Clinical results and satisfaction were assessed by visual analog scale (VAS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), and Likert scale. Radiological assessment involved the evaluation of the medial proximal tibial angle (MPTA), tibial slope (TS), Caton–Deschamps index, and knee osteoarthritis grade according to Ahlbäck classification. Pre- and postoperative results were compared using the two-tailed t-test or Wilcoxon’s test of independent samples for paired data or nonparametric analog. P < 0.05 was considered significant.

Results

At medium-term follow-up, Z-shaped MOWHTO showed a survival rate of 95 ± 1.7% with failure occurring in four knees due to symptom recurrence and osteoarthritis progression. No perioperative complications were observed (intraarticular fracture, delayed union or nonunion, and neurological injury). Mean bone healing time was 12 weeks. Clinical scores showed significant improvement at last follow-up and a good grade of satisfaction. MPTA increased significantly, while Caton–Deschamps index decreased significantly. No significant TS increase was found.

Conclusions

Modified biplanar Z-shaped MOWHTO is a safe and reliable technique that offers satisfactory clinical and radiological medium-term outcomes with low knee arthroplasty conversion rate. The unique three-dimensional geometrical conformation potentially provides a favorable environment for bone healing, increased anteroposterior and rotational stability, and safer opening-wedge loading force application with low lateral hinge fracture risk.

Level of evidence

Level IV, retrospective observational case series study.

Trial registration The study protocol was approved by the Internal Review Board of our Institution (authorization number 54/2019, 20 November 2019).

Good long-term survival and patient-reported outcomes after high tibial osteotomy for medial compartment osteoarthritis

The lateral closing and medial opening wedge high tibial osteotomy can correct a varus malalignment of the knee caused by medial compartment osteoarthritis. These procedures have produced great short-term and mid-term results. As no systematic review has examined their long-term results yet, the goal of this article was to compare the results of all articles about lateral closing and medial opening wedge high tibial osteotomies, published after the year 2000, with a mean follow-up of more than 10 years. A systematic search of the Medline, Web of Science and Cochrane databases resulted in the inclusion of 30 articles. All these studies combined examined the results of 7087 high tibial osteotomies in a total of 6636 patients after a mean follow-up of more than 10 years. Primary outcome measures were the survival rate of the osteotomy, functional scores, patient satisfaction and pain scores. Secondary outcome measures were alignment correction and the identification of factors influencing the survival of the osteotomy. The 5-year, 10-year, 15-year and 20-year survival rates, respectively, ranged from 86 to 100%, 64-97.6%, 44-93.2% and 46-85.1%. The subjective scoring systems showed an improvement postoperatively that was maintained until final follow-up. The anatomical and mechanical tibiofemoral axis were, respectively, corrected to a mean of 7.3°-13.8° of valgus and 0.6°-4° of valgus. The results of the articles evaluating the influence of potential risk factors were contradictory. Despite the low quality of the available evidence, the lateral closing and medial opening wedge high tibial osteotomy seem to remain valid long-term treatment options for patients with painful varus malalignment caused by isolated medial compartment osteoarthritis of the knee. The available results indicate that the need for arthroplasty could be delayed for more than 15 years in the majority of patients. However, higher-quality studies are needed to confirm these findings. As a systematic review is assigned a level of evidence equivalent to the lowest level of evidence used from the analyzed manuscripts, the level of evidence of this systematic review is IV.

Long-Term Survivorship of Closed-Wedge High Tibial Osteotomy for Severe Knee Osteoarthritis: Outcomes After 10 to 37 Years

Background:

High tibial osteotomy (HTO) was developed as a joint-preserving procedure to treat relatively young patients with isolated medial compartmental knee osteoarthritis (OA). Long-term survivorship after HTO is important to determine whether patients will need additional surgery.

Purpose:

To determine the long-term (>35-year) survivorship and prognostic factors for closed-wedge HTO (CWHTO) for severe medial OA.

Study Design:

Case series; Level of evidence, 4.

Methods:

We retrospectively evaluated patients who underwent CWHTO for severe medial knee OA between 1983 and 2009 at our institution, Nagoya University Graduate School of Medicine (Nagoya, Japan). Patient demographics, follow-up period, and pre- and postoperative femoral-tibial angle (FTA) were reviewed. The patients or the relatives of the patients were interviewed by telephone to record postoperative status, including conversion to total knee arthroplasty (TKA).

Results:

Of the 74 CWHTO procedures performed, we evaluated 56 procedures in 45 patients (mean age at time of surgery, 56.8 years). The mean follow-up period was 17.1 years. Nine knees (16.1%) underwent conversion to TKA. The mean time to TKA conversion was 15.6 years. Kaplan-Meier analysis revealed a 10-year survival rate of 90.1%, a 15-year rate of 83.8%, a 20-year rate of 75.9%, and a 35-year rate of 75.9%. Log-rank test showed that age ≥55 years (P = .044), body mass index (BMI) ≥25 kg/m² (P = .0016), and preoperative FTA <185° (P = .0034) were risk factors associated with TKA conversion. Multivariate analyses adjusted for age and sex identified BMI ≥25 kg/m² (hazard ratio [HR], 13.4; 95% CI, 1.7-106.9; P = .014) and preoperative FTA <185° (HR, 4.2; 95% CI, 1.1-16.6; P = .04) as risk factors associated with TKA conversion.

Conclusion:

The survival rate of CWHTO for severe medial knee OA was 90.1% at 10 years, 83.8% at 15 years, and 75.9% at 20 years and 35 years. Furthermore, a BMI ≥25 kg/m² and FTA <185° were the independent risk factors associated with TKA conversion after CWHTO.

Return to Work Following Isolated Opening Wedge High Tibial Osteotomy

PURPOSE

Patients with isolated medial compartment osteoarthritis and varus deformity may undergo high tibial osteotomy (HTO) to reduce the contact pressure in the medial compartment. The purpose of this investigation is (1) examine the timeline of return to work (RTW) following HTO and (2) evaluate RTW stratified by occupational intensity.

METHODS

Consecutive patients undergoing HTO were reviewed retrospectively at a minimum of 2-years postoperatively. Patients completed a subjective work questionnaire, a visual analogue scale for pain, Single Assessment Numerical Evaluation, and a satisfaction questionnaire.

RESULTS

Thirty-eight patients were included at an average of 9.0 ± 3.3 years postoperatively. Thirty-seven patients (average age 43.4 ± 7.8 years, 91.9% with a Kellgren-Lawrence grade of III/IV) were employed within 3 years prior to surgery. Eighteen patients (48.6%) underwent subsequent surgery with 14 patients (37.8%) receiving a salvage knee arthroplasty at an average of 6.1 ± 3.5 years following HTO. Thirty-five patients (94.5%) returned to work at an average of 2.9 ± 2.0 months. The rate of RTW for sedentary, light, moderate, and heavy duties were 87.5%, 100%, 100%, and 93.3%, respectively, while the duration until RTW was 1.0 months, 1.1 months, 2.4 months, and 3.3 months, respectively.

CONCLUSION

In a young and active population with osteoarthritis or varus deformity, an HTO allows patients to return to work; however, patients with high-intensity occupations may be absent from work longer than those with lesser physically demanding occupations. HTO is not a definitive treatment option as nearly 40% of patients underwent knee arthroplasty by 6.1 years postoperatively.

LEVEL OF EVIDENCE

IV, case series.

Patellofemoral Osteoarthritis Progresses After Medial Open-Wedge High Tibial Osteotomy: A Systematic Review

PURPOSE

To investigate the progression of patellofemoral (PF) osteoarthritis (OA) after medial open-wedge high tibial osteotomy (OWHTO) and whether PF OA progression has an influence on clinical outcomes.

METHODS

According to the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA), EMBASE, PubMed, and Cochrane Library were searched in June 2020 for English-language studies that presented data on PF OA or cartilage degeneration before and after OWHTO. Descriptive statistics are presented.

RESULTS

Twenty studies comprising 1,173 patients were included. The mean age was 57.1 years (range 18-84) with 826 (70.4%) female. The mean follow-up was 27.1 months (range 7-144). Ten studies reported the trochlear International Cartilage Research Society (ICRS) scores, with each of these studies reporting a greater proportion of patients with grades 2-4 OA postoperatively compared with preoperatively (relative risk = 1.19-2.76, I² = 1.9%). Similarly, 7 studies reported patellar ICRS scores and found a greater proportion with grades 2-4 OA postoperatively (relative risk = 1.08-2.44, I² = 0%). Four studies assessed PF Kellgren-Lawrence grade, each of which reported a greater proportion of patients with grades 2-4 OA postoperatively (relative risk = 1.25-21.0, I² = 31%). The PF OA assessments were heterogenous, and studies using classifications except the ICRS score or Kellgren-Lawrence grade were not included in statistical analysis. Fifteen studies assessed patellar height; 10 studies reported significant decrease in patellar height after OWHTO. Only 3 studies reported clinical outcomes for patients with and without PF OA progression. Outcome reporting was variable across these studies, and a relationship between PF OA progression and clinical outcome could not be definitively determined.

CONCLUSIONS

Patients appear to have progression of PF OA after medial OWHTO. However, there are currently insufficient studies with inconsistent measurements of outcomes to make meaningful conclusions regarding the impact of PF OA on clinical outcomes.

LEVEL OF EVIDENCE

Level IV, systematic review of Level III-IV studies.

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

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

Influence of medial open wedge high tibial osteotomy on tibial tuberosity-trochlear groove distance

PURPOSE

Medial open wedge high tibial osteotomy (MOWHTO) is an effective treatment option for realignment of a varus knee. However, a simple supra-tuberositary osteotomy can lead to patella baja and potentially increases the tibial tuberosity-trochlear groove distance (TTTG). The purpose of this study was to quantify the influence of MOWHTO on TTTG.

METHODS

Three-dimensional (3D) surface models of five lower extremities with a varus hip-knee-ankle angle (HKA) and a borderline TTTG (≥ 15 mm), five lower extremities with a varus HKA and a normal TTTG (< 15 mm) and a 3D statistical shape model (SSM) of a neutrally aligned healthy knee were analysed by simulating MOWHTO with a stepwise increment of one degree of valgisation from the preoperative coronal deformity (0°-15°) for each patient, resulting in a total of 165 simulations. Postoperative 3D TTTG and tibial torsion (TT) were measured for each simulation. A mathematical formula was developed to calculate the increase of TTTG after MOWHTO. Mean differences between simulated and calculated TTTG were analysed.

RESULTS

Mean preoperative HKA was 6.5 ± 3.0° varus (range 0.8°-11.5°). Mean TTTG increased from 14.2 ± 3.2 mm (range 9.6-19.1) preoperatively to 18.8 ± 3.8 mm (range 14.5-25.0) postoperatively (p = 0.001). TTTG increased approximately linear by + 0.5 ± 0.2° (range 0.3-0.8) per 1° of valgisation with a high positive correlation (0.99, p = 0.001) from 0° to 15°. Mean difference between simulated and calculated TTTG was 0.03 ± 0.02 mm (range 0.01-0.07) per 1° of valgisation (p < 0.001).

CONCLUSION

MOWHTO results in an approximately linear increase in TTTG of + 0.5 mm per 1° of valgisation in the range from 0° to 15° and the lateralisation of the tibial tuberosity can be calculated reliably using the described formula. Preoperative analysis of TTTG in patients undergoing MOWHTO may prevent unintentional patellofemoral malalignment.

LEVEL OF EVIDENCE

III.

A new double level osteotomy procedure to restore a joint line and joint angles in severe varus osteoarthritis. - Double level osteotomy associated with tibial condylar valgus osteotomy (DLOTO)

High tibial valgus osteotomy (HTO) is a well-established surgical procedure to correct a varus malalignment and treat medial compartment osteoarthritis. Recently, double level osteotomy (DLO) was recommended for extensive varus knees as a single level osteotomy (SLO) approach may create an excessive joint line obliquity and eventually result in a new bony deformity. However, a severe varus knee in cases of advanced osteoarthritis involves not only a bony deformity (extra-articular deformity) but also a medial joint space narrowing with a widened lateral joint space (intra-articular deformity). A DLO alone cannot reduce this intra-articular deformity. However, tibial condylar valgus osteotomy (TCVO) can complement DLO as to reduce this intra-articular deformity. This technical note describes a novel modified DLO procedure associated with TCVO which can restore a normal alignment and a joint line and achieve joint preservation even in cases of extensive varus osteoarthritis.

Differences in patient-reported outcomes between medial opening-wedge high tibial osteotomy and total knee arthroplasty

PURPOSE

To compare patient subjective satisfaction between medial opening-wedge high tibial osteotomy (HTO) and total knee arthroplasty (TKA).

METHODS

This study enrolled 110 knees, including comprising 49 knees in the HTO group, and 61 knees in the TKA group. We assessed the overall satisfaction using a three-point questionnaire. The satisfaction questionnaire included three questions: (1) How satisfied are you with the results of your knee surgery? (2) How satisfied are you with your most recent knee surgery for reducing your pain? and (3) How satisfied are you with your most recent knee surgery for improving your ability to perform functions? Furthermore, we assessed knee pain and function by using the Knee Society Function Score (KSS) and Knee Injury and Osteoarthritis Outcome Score (KOOS) systems.

RESULTS

Overall, 93.8% of patients from the HTO group and 95.1% from the TKA group indicated subjective satisfaction (very satisfied and satisfied) with their surgeries. For pain relief, the HTO group showed significantly better outcomes for overall satisfaction (p = 0.04 in walking on a flat surface and p = 0.02 in going upstairs or downstairs). For restored function, the HTO group scored significantly better on ascending stairs than the TKA group (p = 0.007). Functional outcomes using the KSS scoring system did not show significant differences between the two groups. The KOOS pain score was significantly higher in the TKA group (89.9 ± 6.4) than in the HTO group (80.3 ± 12.5).

CONCLUSION

HTO and TKA have comparable outcomes with respect to overall patient satisfaction.

LEVEL OF EVIDENCE

Level III, therapeutic case series.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

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

Closing-wedge high tibial osteotomy, a reliable procedure for osteoarthritic varus knee

PURPOSE

The purpose of this study was to analyze the long-term clinical and radiological outcomes of patients who underwent closing-wedge High Tibial Osteotomy (HTO) for the treatment of medial compartment osteoarthritis and to evaluate the conversion rate to knee arthroplasty.

METHODS

A retrospective, non-randomized, monocentric study was performed in our Institution considering 166 patients between 1989 and 2012. The final population was composed by 82 patients (94 knees), median age at time of operation was 53 (range 45-73) years. All patients were evaluated clinically (HSS Score, Tegner Scale, VAS and Crosby-Insall Grading) and radiographically (osteoarthritis staging, hip-knee-ankle (HKA) angle, tibial slope and metaphyseal varus).

RESULTS

Mean follow-up was 11.9 ± 7.2 years. HSS Score increased significantly from 70.8 ± 10 to 93.2 ± 9.1 (p < 0.05) instead Tegner Scale increased from 1.3 ± 0 (range 1-4) to 2.8 ± 0.7 (range 2-6) at the last control (n.s.); VAS score significantly decreased from 7.9 ± 1.4 to 1.6 ± 1.1 (p < 0.05) at last follow-up. According to the Crosby-Insall Grading System, 80 patients (97.4%) reported excellent-good results. HKA angle decreased from 6.9° ± 3.5 to 2.6° ± 2.6 (p < 0.01), tibial slope decreased from 10.1° ± 1.4 to 6.8° ± 2.1 (p < 0.05) and finally the metaphyseal varus decreased from 4.2° ± 0 to 2.1° ± 1.2 (n.s.) at the last follow-up. Adverse events were reported in 4.8%. Osteotomy survivorship rate resulted 92% at 10 years, 82% at 15 years and 80% at 20 years. Sixteen revisions (9.6%) were reported at a mean period of 12.8 years.

CONCLUSIONS

CW-HTO is a valid option for medial osteoarthritis treatment, with successful results in both clinical and radiological outcomes.

LEVEL OF EVIDENCE

IV.

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

Background:

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

Purpose:

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

Study Design:

Case-control study; Level of evidence, 3.

Methods:

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

Results:

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

Conclusion:

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

Medical Comorbidities and Functional Dependent Living Are Independent Risk Factors for Short-Term Complications Following Osteotomy Procedures about the Knee

OBJECTIVE

To characterize rates and risk factors for adverse events following distal femoral osteotomy (DFO), high tibial osteotomy (HTO), and tibial tubercle osteotomy (TTO) procedures.

DESIGN

Patients undergoing DFO, HTO, or TTO procedures during 2005 to 2016 were identified in the American College of Surgeons National Surgical Quality Improvement Program. Rates of adverse events were characterized for each procedure. Demographic, comorbidity, and procedural factors were tested for association with occurrence of any adverse events.

RESULTS

A total of 1,083 patients were identified. Of these, 305 (28%) underwent DFO, 273 (25%) underwent HTO, and 505 (47%) underwent TTO. Mean ages for patients undergoing each procedure were the following: DFO, 51 ± 23 years; HTO, 40 ± 13 years; and TTO, 31 ± 11 years. The most common comorbidities for DFO were hypertension (34%) and smoking (17%); for HTO, hypertension (22%) and smoking (21%); and for TTO, smoking (20%) and hypertension (11%). Independent risk factors for occurrence of any adverse event were age ⩾45 years for DFO (odds ratio [OR] = 3.1, P < 0.001) and HTO (OR = 2.3, P = 0.029), and body mass index >30 for HTO (OR = 2.5, 95% confidence interval = 1.1-5.7, P = 0.031). When all osteotomy procedures were analyzed collectively, additional variables including diabetes mellitus (OR = 2.2, P = 0.017), chronic obstructive pulmonary disease (OR = 5.5, P = 0.003), and dependent functional status (OR = 3.0, P = 0.004) were associated with adverse events.

CONCLUSIONS

The total rate of adverse events was not independently associated with the type of osteotomy procedure. In addition, patients with age >45, diabetes mellitus, chronic obstructive pulmonary disease, and dependent functional status have greater odds for adverse events and should be counseled and monitored accordingly.

Patient-specific high-tibial osteotomy's 'cutting-guides' decrease operating time and the number of fluoroscopic images taken after a Brief Learning Curve

PURPOSE

Patient-specific cutting guides (PSCGs) have been advocated to improve the accuracy of deformity correction in opening-wedge high-tibial osteotomies (HTO). It was hypothesized that PSCGs for HTO would have a short learning curve. Therefore, the goals of this study were to determine the surgeons learning curve for PSCGs used for opening-wedge HTO assessing: the operating time, surgeons comfort levels, number of fluoroscopic images, accuracy of post-operative limb alignment and functional outcomes.

METHODS

This prospective cohort study included 71 consecutive opening-wedge HTO with PSCGs performed by three different surgeons with different experiences. The operating time, the surgeon's anxiety levels evaluated using the Spielberger State-Trait Anxiety Inventory (STAI), the number of fluoroscopic images was systematically and prospectively collected. The accuracy of the postoperative alignment was defined by the difference between the preoperative targeted correction and the final post-operative correction both measured on standardized CT-scans using the same protocol (ΔHKA, ΔMPTA, ΔPPTA). Functional outcomes were evaluated at 1 year using the different sub-scores of the KOOS. Cumulative summation (CUSUM) analyses were used to assess learning curves.

RESULTS

The use of PSCGs in HTO surgery was associated with a learning curve of 10 cases to optimize operative time (mean operative time 26.3 min ± 8.8), 8 cases to lessen surgeon anxiety levels, and 9 cases to decrease the number of fluoroscopic images to an average of 4.3 ± 1.2. Cumulative PSCGs experience did not affect accuracy of post-operative limb alignment with a mean: ΔHKA = 1.0° ± 1.0°, ΔMPTA = 0.5° ± 0.6° and ΔPPTA = 0.4° ± 0.8°. No significant difference was observed between the three surgeons for these three parameters. There was no statistical correlation between the number of procedures performed and the patient's functional outcomes.

CONCLUSION

The use of PSCGs requires a short learning curve to optimize operating time, reduce the use of fluoroscopy and lessen surgeon's anxiety levels. Additionally, this learning phase does not affect the accuracy of the postoperative correction and the functional results at 1 year.

LEVEL OF EVIDENCE

II: prospective observational study.

Intra-articular Injection of Culture-Expanded Mesenchymal Stem Cells Without Adjuvant Surgery in Knee Osteoarthritis: A Systematic Review and Meta-analysis

BACKGROUND

Although many clinical studies have assessed the efficacy of mesenchymal stem cells (MSCs) in knee osteoarthritis, evidence on their efficacy remains unclear owing to heterogeneity of cell entity and concomitant procedures.

PURPOSE

To determine the efficacy of culture-expanded MSCs in knee osteoarthritis in terms of clinical outcome and cartilage repair via meta-analysis of randomized controlled trials (RCTs) without adjuvant surgery.

STUDY DESIGN

Meta-analysis.

METHODS

PubMed, Embase, the Cochrane Library, CINAHL, and Scopus were searched from inception to December 31, 2018. RCTs with culture-expanded MSCs for treating knee osteoarthritis were included. Studies with adjuvant surgery or cell concentrate were excluded. Quality was assessed by the Cochrane Collaboration risk-of-bias tool. For meta-analysis, data on clinical outcomes were measured using a visual analog scale (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and data on cartilage repair were measured using the Whole-Organ Magnetic Resonance Imaging Score (WORMS); categorization related to improvement was extracted.

RESULTS

Six RCTs (203 patients) were included. Two studies were deemed to have a low risk of bias. In pooled analysis, the only significant difference was in the VAS score (mean difference, -13.55; 95% CI, -22.19 to -4.9). In cumulative pain analysis with VAS and WOMAC pain scores, there was significant improvement after treatment (standardized mean difference, -0.54; 95% CI, -0.85 to -0.23). There was no significant difference in cartilage repair assessed by magnetic resonance imaging (standardized mean difference, 0.11; 95% CI, -0.51 to 0.73), WORMS (standardized mean difference, 1.68; 95% CI -14.84 to 18.21), or categorical results (odds ratio, 1.56; 95% CI, 0.32-7.59).

CONCLUSION

Intra-articular injection of culture-expanded MSCs without adjuvant surgery can improve pain for patients experiencing knee osteoarthritis at short-term follow-up (6-12 months). However, evidence regarding function and cartilage repair remains limited.

Return to Sport Following High Tibial Osteotomy With Concomitant Osteochondral Allograft Transplantation

BACKGROUND

Young patients with symptomatic chondral defects in the medial compartment with varus malalignment may undergo opening wedge high tibial osteotomy (HTO) with concomitant osteochondral allograft transplantation (OCA) (HTO + OCA). Although patients have demonstrated favorable outcomes after HTO + OCA, limited information is available regarding return to sporting activities after this procedure.

PURPOSE

To evaluate (1) the timeline to return to sports (RTS), (2) patient satisfaction, and (3) reasons for discontinuing sporting activity after HTO + OCA, and to identify predictive factors of RTS.

STUDY DESIGN

Case series; level of evidence, 4.

METHODS

Consecutive patients who underwent HTO + OCA for varus deformity and medial femoral condyle focal chondral defects with a minimum 2-year follow-up were retrospectively reviewed. Patients completed a subjective sports questionnaire, satisfaction questionnaire, visual analog scale for pain, and Single Assessment Numerical Evaluation.

RESULTS

Twenty-eight patients with a mean age of 36.97 ± 7.52 years were included at mean follow-up of 6.63 ± 4.06 years. Fourteen patients (50.0%) required reoperation during the follow-up period, with 3 (10.7%) undergoing knee arthroplasty. Twenty-four patients participated in sports within 3 years before surgery, with 19 patients (79.2%) able to return to at least 1 sport at a mean 11.41 ± 6.42 months postoperatively. However, only 41.7% (n = 10) were able to return to their preoperative level. The most common reasons for sports discontinuation (n = 20; 83.3%) were a desire to prevent further damage to the knee (70.0%), persistent pain (55.0%), persistent swelling (30.0%), and fear (25.0%).

CONCLUSION

In young, active patients with varus deformity and focal medial femoral condyle chondral defects, HTO + OCA enabled 79.2% of patients to RTS by 11.41 ± 6.42 months postoperatively. However, only 41.7% of patients were able to return to their preinjury level or better. It is imperative that patients be appropriately educated to manage postoperative expectations regarding sports participation after HTO + OCA.

Return to Work and Sport After Proximal Tibial Osteotomy and the Effects of Opening Versus Closing Wedge Techniques on Adverse Outcomes: A Systematic Review and Meta-analysis

BACKGROUND

Although many studies have reported successful functional outcomes after proximal tibial osteotomy (PTO), a paucity of literature has sought to quantify outcomes and current rates of return to sport (RTS) and return to work (RTW) after PTO.

PURPOSE

To (1) determine current rates of RTS and RTW after PTO and (2) quantify the incidence of complications and conversion to total knee arthroplasty (TKA) after PTO for all patients as well as those undergoing opening and closing wedge PTO.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

The Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed (2008-2019), EMBASE (2008-2019), and MEDLINE (2008-2019) databases were queried. Data pertaining to article information, patient demographics, surgical techniques, rates of complication and conversion to TKA, patient-reported outcome scores, RTS, and RTW were extracted. Data were synthesized, and a random effects meta-analysis of proportions using continuity correction methods was performed to determine the proportion of patients receiving opening and closing wedge PTO who experienced adverse events.

RESULTS

The review and meta-analysis included 33 studies involving 1914 patients who underwent PTO with a weighted mean ± SD age of 50.3 ± 9.9 years and body mass index of 26.9 ± 2.3 kg/m². The pooled RTS and RTW rates were 75.7% (range, 55%-100%) in 814 patients and 80.8% (range, 41%-100%) in 505 patients, respectively. The pooled TKA rate was 12.5% (range, 0%-35.7%) at a mean of 70.6 months and the pooled complication rate was 11.1% (range, 0%-28.6%). The overall random pooled summary estimate of the proportion of patients who underwent opening wedge PTO and subsequently converted to TKA was 2.0% (95% CI, 1.0%-4.0%; I² = 63.65) at a mean of 43.4 ± 31.9 months and who experienced a complication was 6.0% (95% CI, 3.0%-9.0%; I² = 87.10%). For closing wedge PTO, the proportion of patients who converted to TKA was 5.0% (95% CI, 1.0%-9.0%; I² = 93.1%) and experienced a complication was 2.0% (95% CI, 1.0%-3.0%; I² = 90.0%). Only 53.8% of studies that referenced RTS provided postoperative RTS rates, and 80% of studies that referenced RTW provided RTW rates. Only 1 study defined RTS criteria, no studies defined RTW criteria, and 31 different outcome measures were reported across all studies.

CONCLUSION

Patients undergoing PTO for osteoarthritis, cartilage defects, and symptomatic malalignment of the knee experience high rates of RTS and RTW. These patients also experience low rates of complications and conversion to TKA, regardless of opening or closing wedge technique. Significant heterogeneity exists with regard to criteria used to define RTS and RTW and patient-reported outcome measures used to assess clinical and functional improvements after PTO.

Changes in knee joint line orientation after high tibial osteotomy are the result of adaptation of the lower limb to the new alignment

BACKGROUND

Changes in knee joint line orientation (KJLO) resulting in excessive joint line obliquity are a well-known consequence of high tibial osteotomy (HTO) procedures and could lead to degenerative changes. The precise effect of the correction on final KJLO changes is poorly understood. The goal of this study was to identify radiographical parameters that could help to explain the size of KJLO changes after HTO surgery.

METHODS

A total 117 HTO patients were radiographically examined preoperatively and three months postoperatively. Radiographic parameters were KJLO, medial proximal tibial angle (MPTA), hip-knee angle (HKA), mechanical lateral distal femoral angle (mLDFA), lateral distal tibial angle (LDTA), knee joint line congruence angle (KJLCA), ankle joint line congruence angle (AJLCA) and ankle joint line orientation (AJLO). Four new radiographic parameters were introduced to describe knee and foot position on long-leg X-ray: malleolar distance to midline (MDTM), intermalleolar distance (IMD), condylar distance to midline (CDTM) and intercondylar distance (ICD). Correlations of these parameters and changes in KJLO were assessed.

RESULTS

Strong correlations are found between KJLO changes and MDTM (r = 0.709), IMD (r = 0.691), CDTM (r = 0.711) and ICDM (r = 0.702), in contrast to weak correlations between changes in KJLO and MPTA (r = -0.342). These results suggest an important impact of foot and knee position changes on the final alteration of KJLO after HTO.

CONCLUSIONS

The final change of KJLO after HTO is the effect of adaptation of the lower limb, which is driven by the (maximum) alterations of foot and knee position rather than the size of correction of the procedure.

Distal tuberosity osteotomy in open-wedge high tibial osteotomy does not exacerbate patellofemoral osteoarthritis on arthroscopic evaluation

PURPOSE

The purpose of the present study was to use arthroscopy to evaluate the effect of distal tuberosity osteotomy (DTO) in open-wedge high tibial osteotomy (OW-HTO) on patellofemoral (PF) cartilage degradation.

METHODS

Between 2012 and 2017, 46 knees underwent DTO in OW-HTO, and 65 knees underwent conventional OW-HTO (cOW-HTO). To assess changes in patellar height, the Blackburne-Peel (BP) ratio and the Caton-Deschamps (CD) index were measured. Arthroscopic evaluation on the PF joint was performed at the initial osteotomy and at the second-look procedure 1 year later. Statistical analyses were performed to compare difference between the DTO and the cOW-HTO group.

RESULTS

In the cOW-HTO group, the mean BP ratio and CD index decreased significantly from 0.81 and 0.89 preoperatively, respectively, to 0.69 and 0.76 postoperatively, respectively (p < 0.001). In contrast, the DTO group maintained a consistent patellar height; the mean BP ratio and CD index were 0.77 and 0.83 preoperatively, respectively, and 0.73 and 0.80 postoperatively, respectively. Upon arthroscopic evaluation, 39 of 46 patients (84.8%) in the DTO group showed no progression of PF cartilage degradation at the second look; indeed, five of 46 patients (10.9%) even demonstrated improvement. In contrast, 21 of 65 patients (32.3%) in the cOW-HTO group exhibited increased PF cartilage degradation. There was a significant difference in progression of PF cartilage degradation between DTO and cOW-HTO (p < 0.001).

CONCLUSION

DTO in OW-HTO maintained the preoperative patellar height, which could help prevent progression of cartilage degeneration in the PF joint after surgery. In respect of the biplanar osteotomy direction in OW-HTO, the DTO, rather than cOWHTO, is the preferred technique for the treatment of varus knee osteoarthritis to avoid progression of PF cartilage degradation.

LEVEL OF EVIDENCE

III.

Classical target coronal alignment in high tibial osteotomy demonstrates validity in terms of knee kinematics and kinetics in a computer model

PURPOSE

The purpose of this study was to determine the ideal coronal alignment under dynamic conditions after open-wedge high tibial osteotomy (OWHTO). It was hypothesised that, although the classical target alignment was based on experimental evidence, it would demonstrate biomechanical validity.

METHODS

Musculoskeletal computer models were analysed with various degrees of coronal correction in OWHTO during gait and squat, specifically with the mechanical axis passing through points at 40%, 50%, 60%, 62.5%, 70%, and 80% of the tibial plateau from the medial edge, defined as the weight-bearing line percentage (WBL%). The peak load on the lateral tibiofemoral (TF) joint, the medial collateral ligament (MCL), and anterior cruciate ligament (ACL) tensions, and knee kinematics with or without increased posterior tibial slope (PTS) were evaluated.

RESULTS

The classical alignment with WBL62.5% achieved sufficient load on the lateral TF joint and maintained normal knee kinematics after OWHTO. However, over-correction with WBL80% caused an excessive lateral load and non-physiological kinematics. Increased WBL% resulted in increased MCL tension due to lateral femoral movement against the tibia. With WBL80%, abnormal contact between the medial femoral condyle and the medial intercondylar eminence of the tibia occurred at knee extension. The screw-home movement around knee extension and the TF rotational angle during flexion were reduced as WBL% increased. Increased PTS was associated with increased ACL tension and decreased TF rotation angle because of ligamentous imbalance.

CONCLUSIONS

The classical target alignment demonstrated validity in OWHTO, and over-correction should be avoided as it negatively impacts clinical outcome.

LEVEL OF EVIDENCE

IV.

Satisfactory long-term survival, functional and radiological outcomes of open-wedge high tibial osteotomy for managing knee osteoarthritis: Minimum 10-year follow-up study

Background

This prospective cohort study was designed to evaluate the survivorship and functional outcomes associated with long-term results of medial open-wedge high tibial osteotomy (MOWHTO) for the treatment of medial compartment knee osteoarthritis in the Chinese population. Although MOWHTO is a well-established procedure in the management of medial osteoarthritis of the knee, the long-term outcome in the Chinese population has not been reported in current literature. We hypothesised that MOWHTO would result in long-term preservation of knee function in Chinese, similar to that reported in the Caucasian population.

Methods

A cohort of 22 young adult patients (age < 55 years old) undergoing MOWHTO for the treatment of symptomatic medial compartment knee osteoarthritis between 2002 and 2008 was retrospectively surveyed with a minimum follow-up of 10 years. Kaplan–Meier survival analysis was performed, and the failure modes were investigated. The outcomes on survival (not requiring arthroplasty), clinical outcome (Knee Society Knee Score and Knee Society Function Score) and range of motion (numeric rating scale) at preoperative, 1-year postoperative follow-up and at last follow-up (>10 years) were evaluated. In addition, the mechanical tibiofemoral angle was also measured. The Wilcoxon signed-rank test was used for statistical evaluation of nonparametric data in these related samples.

Result

A total of 31 knees in these 22 cases were included. The follow-up rate was 100% at 13.4 ± 1.9 years (11–17). Mean age at time of surgery was 45.8 ± 9.5 years (18–53). At 10-year follow-up, four knees converted to require total knee arthroplasty (survival: 87.1%). Preoperative varus alignment with mechanical tibiofemoral angle of −9.26 ± 2.83 was corrected to 2.58 ± 2.46 after surgery and remained 2.01 ± 3.52 at the latest follow-up. Knee Society Knee Score increased significantly from 53.7 ± 11.1 preoperatively to 93.8 ± 6.8 at 1-year follow-up and 91.8 ± 9.7 at latest follow-up. Similarly, the functional score also increased significantly from 67.4 ± 21.0 preoperatively to 86.3 ± 14.5 at 1-year follow-up and 82.1 ± 16.6 at latest follow-up (p < 0.01). Whereas, the range of motion significantly decreased from 122.7 ± 6.6 preoperatively to 116.1 ± 15.5 at the latest follow-up.

Conclusion

Even in cases of severe medial osteoarthritis and varus malalignment, MOWHTO would be a good treatment option for management in active Chinese population less than 55 years. Although the long-term survival and functional outcome after MOWHTO was proven to be satisfactory in our cohort during the 10-year follow-up, a larger cohort to illustrate the long-term functional outcome is still warranted.

Translational potential

The finding in this study indicated MOWHTO is a feasible treatment option for young adult patients with osteoarthritis to achieve long-term satisfactory results.

Determination of the postoperative limb alignment following a high tibial osteotomy in patients with uni-compartmental knee osteoarthritis, review article

Objectives

High tibial osteotomy is an established surgical procedure for treatment of mal-aligned Varus knees due to medial compartment knee osteoarthritis. Aims are to evaluate whether post-operative axial alignment achieves good long-term results.

Methods and results

Literature search done and studies with a follow up period of 2 or more years were included. The mean postoperative mechanical axis varied widely from 3 to 16° with significant differences between the studies.

Conclusion

The results suggested that medial knee osteoarthritis can be treated successfully with HTO. The post-operative valgus angle should be between 3 and 13° of valgus to achieve good long-term results.

Health-Related Quality of Life - an Underestimated Factor to Evaluate the Treatment Success after Open Wedge HTO Surgery: Prospective 6-Years Follow-Up

BACKGROUND

The subjective health related quality of life in patients with degenerative joint diseases is an important variable to evaluate the treatment outcome. In this study, mid-term results of open wedge HTO were analysed and compared to the subjective quality of life (SF 36) of the general population. Furthermore, the relationships of preoperative assessed subscales of the health-related quality of life (SF 36) and the conversion to knee arthroplasty were analysed.

METHODS

The cohort consisted of 120 patients who were prospectively followed-up after open wedge HTO. At five follow-up points of time, patients were examined and asked about their subjective, health-related quality of life using the SF 36 score.

RESULTS

104 patients were included and evaluated until the last follow-up (mean: 81.2 ± 11.3 months after open wedge HTO; follow-up rate: 86.7%). Six years after open wedge HTO, similar values in several psychologic subscales of the SF 36 (BP, GH, V, MH) and the mental health component summary score (MCS) compared to the general population were found. The physical health component summary score (PCS) showed a significant improvement relative to the preoperative values. Nine out of 104 patients (8.7%) received a knee arthroplasty (50.1 ± 25.0 months). Low preoperative values of the subscales "physical functioning" (PF) and "bodily pain" (BP) were identified as risk factors in terms of conversion to a total knee arthroplasty.

CONCLUSIONS

Patients with medial unicompartimental knee osteoarthrosis treated with open wedge HTO showed very good results. The health-related quality of life was nearly as high as in the general population. Patients with preoperative low physical function and high pain values have a higher risk to have a conversion to knee arthroplasty. Surgeons should be aware of these factors if an open wedge HTO is considered.

What Factors Predict Patient Dissatisfaction After Contemporary Medial Opening-Wedge High Tibial Osteotomy?

BACKGROUND

Although current advances in surgical techniques have improved outcomes of the medial opening-wedge high tibial osteotomy (MOWHTO), the factors associated with patient dissatisfaction remain unclear. Thus, the purpose of this study is to identify risk factors for patient dissatisfaction following contemporary MOWHTO.

METHODS

We retrospectively reviewed prospectively collected data on 140 consecutive MOWHTO patients using an anatomical locking plate with a minimum follow-up of 2 years. Patient demographics, pain Visual Analogue Scale, Western Ontario and McMaster Universities Osteoarthritis Index, Kellgren-Lawrence (K-L) grade, activity level, articular cartilage and meniscal status, hip-knee-ankle angle, change in alignment, and postoperative weight-bearing line ratio were recorded. Patients were categorized using the New Knee Society Score into satisfied (satisfaction score ≥20) or dissatisfied (satisfaction score <20) groups. Patient and surgical factors were compared between the groups by the identified predictors. Multiple logistic regression analysis was used to analyze risk factors, including K-L grade IV medial osteoarthritis (OA), preoperative pain Visual Analogue Scale, total Western Ontario and McMaster Universities Osteoarthritis Index score, postoperative hip-knee-ankle angle, change in alignment, and partial meniscectomy.

RESULTS

Of the 140 patients, 24 (17.1%) were dissatisfied with their results. Multiple logistic regression analysis showed that only K-L grade IV medial OA was statistically associated with patient dissatisfaction following MOWHTO (odds ratio 4.911, 95% confidence interval 1.820-13.256, P < .01).

CONCLUSION

Severe medial OA was an independent risk factor for dissatisfaction following contemporary MOWHTO using a rigid locking plate. Surgeons should take this into consideration when counseling and choosing surgical options in MOWHTO candidates with severe medial OA.

LEVEL OF EVIDENCE

Level III.

The influence of post-operative knee coronal alignment parameters on long-term patient-reported outcomes after closed-wedge high tibial osteotomy

Background

Both intra-articular and extra-articular knee alignment pathologies can affect clinical outcomes after high tibial osteotomy. The purpose of this study was to investigate post-operative knee coronal alignment parameters that affect long-term patient-reported outcomes after closed-wedge high tibial osteotomy (CW-HTO).

Methods

This study included 105 osteoarthritic knees that underwent CW-HTO. Long-term patient-reported outcomes were defined by the 2011 Knee Society Score (KSS) and were collected at an average follow-up of 10.2 years. Post-operative knee coronal alignment parameters, consisting of the femoral tibial angle (FTA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), tibial plateau inclination (TPI), and joint line convergence angle (JLCA), were measured using standing radiographs of the knee at an average follow-up of 11.0 months. The correlations between these parameters and KSS were then assessed by Spearman's correlation analysis. Comparisons of groups classified by MPTA and TPI cutoff values were performed by the Wilcoxon rank-sum test.

Results

Post-operative JLCA showed a significant negative correlation with two KSS sub-scores: satisfaction (R = -0.2232, P = 0.022) and total function (R = -0.2059, P = 0.035). There was no significant difference in any KSS sub-score between the "low" groups (MPTA and TPI less than 95 and 5°, respectively) and the "high" groups (MPTA and TPI greater than 98 and 7°, respectively).

Conclusions

Among knee coronal alignment parameters, a large post-operative residual JLCA, which is an intra-articular varus deformity, was independently associated with worsened long-term clinical outcomes after CW-HTO.

Level of evidence

Level Ⅳ, Retrospective cohort study.

High Tibial Osteotomy Survivorship: A Population-Based Study

Background

High tibial osteotomy (HTO) was developed to treat early medial compartment osteoarthritis in varus knees.

Purpose

To evaluate the midterm and long-term outcomes of HTO in a large population-based cohort of patients.

Study Design

Case-control study; Level of evidence, 3.

Methods

Data from the California Office of Statewide Health Planning and Development were used to identify patients undergoing HTO from 2000 to 2014. Patients with infectious arthritis, rheumatological disease, congenital deformities, malignancy, concurrent arthroplasty, or skeletal trauma were excluded. Demographic information was assessed for every patient. Failure was defined as conversion to total or unicompartmental knee arthroplasty. Differences between patients requiring arthroplasty and those who did not were identified using univariate analysis. Multivariate analysis was performed, and Kaplan-Meier survivorship estimates for 5- and 10-year survival were computed.

Results

A total of 1576 procedures were identified between 2000 and 2014; of these, 358 procedures were converted to arthroplasty within 10 years. Patients who went on to arthroplasty after HTO were older (48.23 ± 6.76 vs 42.66 ± 9.80 years, respectively; P < .001), had a higher incidence of hypertension (25.42% vs 17.82%, respectively; P = .001), and had a higher likelihood of having ≥1 comorbidity (38.0% vs 31.4%, respectively; P = .044). Patients were 8% more likely to require arthroplasty for each additional year in age (relative risk [RR], 1.08). Female patients were also at an increased risk of conversion to arthroplasty compared with male patients (RR, 1.38). Survivorship at 5 and 10 years was 80% and 56%, respectively, and the median time to failure was 5.1 years.

Conclusion

HTO may provide long-term survival in select patients. Careful consideration should be given to patient age, sex, and osteoarthritis of the knee when selecting patients for this procedure.

Return to sport following isolated opening wedge high tibial osteotomy

BACKGROUND

The purposes of the study are as follows: (1) examine the timeline of return to sport (RTS) following isolated high tibial osteotomy (HTO), (2) evaluate the degree of participation and function upon RTS and (3) identify reasons that patients do not return or discontinue participation in sport activity.

METHODS

Patients undergoing isolated HTO were reviewed retrospectively at a minimum of two years post-operatively. Patients completed a subjective sports questionnaire, a visual analog scale for pain, Single Assessment Numerical Evaluation, and a satisfaction questionnaire.

RESULTS

Thirty-eight patients (70.4%) were included at an average of 9.0 ± 3.3 years. Thirty-four patients (average age 42.7 ± 7.2 years, 90.0% with a Kellgren-Lawrence grade of III/IV) participated in sports within three years prior to surgery. Eighteen patients (52.9%) returned to the operating room by the time of final follow-up, including 13 patients (38.2%) who underwent salvage arthroplasty by 6.1 ± 3.6 years following HTO. Thirty patients (88.2%) returned to ≥1 sport at an average of 7.5 ± 5.0 months; however only 41.2% were able to return to preinjury level of participation.

CONCLUSIONS

In patients with medial osteoarthritis and varus deformity, isolated high tibial osteotomy provides a high rate (88.2%) of return to sport by 7.5 months postoperatively, yet only a fraction of patients returned to their preinjury level. HTO is not a definitive treatment option as nearly 40% of patients underwent knee arthroplasty by 6.1 years post-operatively. Patient expectations regarding return to sport can be appropriately managed with adequate preoperative patient education.

LEVEL OF EVIDENCE

IV.

Risk of patella baja after opening-wedge high tibial osteotomy

PURPOSE

Medial opening-wedge high tibial osteotomy (OWHTO) induces a lower patellar position, and the subsequent degree of patellar movement may not be predicted preoperatively. The purpose of this study was to clarify the relationship between preoperative and postoperative patellar height based on the correction angle of OWHTO and to create a formula to predict the appearance of patella baja following OWHTO.

MATERIALS AND METHODS

Seventy-five knees with varus knee osteoarthritis treated with OWHTO were included in this study. The Caton-Deschamps index was used to evaluate patellar height preoperatively and postoperatively, and the cut-off value for preoperative parameters was determined by a receiver operating characteristic curve to determine the risk ratio for postoperative patella baja.

RESULTS

The Caton-Deschamps index significantly decreased from 0.93 to 0.77 after OWHTO ( p < 0.01). The OWHTO correction angle negatively correlated with the delta Caton-Deschamps index ( r = -0.44, p < 0.01), and a 1.7% decrease in the Caton-Deschamps index was shown with a 1° correction angle. Receiver operating characteristic curve analysis revealed that a Caton-Deschamps index of 0.8 was the cutoff for OWHTO; knees with a preoperative Caton-Deschamps index of < 0.8 tended to develop patella baja after OWHTO, with a risk ratio of 9.5 (95% confidence interval [4.3-20.7]).

CONCLUSIONS

OWHTO can induce patella baja, and a 1.7% decrease in the Caton-Deschamps index was shown with a 1°-correction angle. A preoperative Caton-Deschamps index < 0.8 should be considered a risk factor for postoperative patella baja.

LEVEL OF EVIDENCE

Retrospective study, Level IV.

Opposite hinge fractures in high tibial osteotomy: a displacement subtype is more critical than a fracture type

PURPOSE

Analysis of the structure of the fractures of opposite hinge (FOH) after angle-stable closed-wedge (CW) and open-wedge (OW) high tibial osteotomy (HTO), and their influence on the development of tibial pseudarthrosis.

METHODS

187 CW and 94 OWHTOs were analyzed retrospectively. The FOHs in the OWHTO were classified according to Takeuchi, and in the CWHTO-according to the own classification with two types (depending on the direction of FOH). FOHs in both techniques were also subdivided into three subtypes according to displacement (A-non-displaced, B-primarily displaced, C-secondarily displaced). The statistical analysis included correlation analysis and logistic regression.

RESULTS

FOHs were found in 81 (43.3%) CW and 39 (41.2%) OWHTOs. The stable type 1 fractures predominated in OWHTO (76.9 vs. 42%, p < 0.001), the unstable type 2 FOHs prevailed in CWHTO (58 vs. 17.9%, p < 0.001). The tibial pseudarthrosis rate was higher with type 1 (20 vs. 12.9%, n.s.) and subtype A (16.7 vs. 6.8%, p = 0.048) FOHs in OWHTO, and with type 2 (20 vs. 0%, p < 0.001) and subtypes B (25 vs. 0%, p < 0.001) and C (29.4 vs. 25%, n.s.) in CWHTO (without FOHs 0.9% in CW and 1.8% in OWHTO, n.s.). Relevant correlations were detected between the pseudarthrosis rate and fracture type only in CWHTO (ρ_s = 0.298, p < 0.001, OR 24.87 for type 2) and displacement subtype in both groups (for subtype C: ρ_s = 0.345, p < 0.001, OR 43.75 and ρ_s = 0.231, p = 0.02, OR 18.0, respectively).

CONCLUSIONS

The unstable FOH types were more common in CWHTO. The displacement subtype was more predictive for the development of tibial pseudarthrosis than the fracture type, especially in OWHTO. The secondarily displaced FOHs (subtype C) represented the highest risk for the occurrence of pseudarthrosis in both techniques.

Patient reported outcomes after high tibial osteotomy show comparable results at different ages in the mid-term to long-term follow-up

BACKGROUND

Few studies have evaluated the impact of age on patient-reported outcomes in the long-term follow-up after high tibial valgus osteotomy (HTO). The purpose of this study is to assess the association between age at surgery and patient-reported clinical outcomes in the mid-term to long-term follow-up of HTO.

MATERIALS AND METHODS

We mailed the 2011 Knee Society score (KSS) questionnaires to 234 consecutive patients (295 knees) who had undergone closing-wedge HTO, and 158 patients (202 knees, 68.5%) returned a completed questionnaire. The cohort was divided into two groups depending on the age at the time of surgery, and pairs matched the follow-up period and sex was created. The mean follow-up period was approximately 12 years. KSS scores at the final follow-up were compared between two groups using the Student t test and chi-square test, and the survival rates were calculated using Kaplan-Meier survival curves.

RESULTS

The symptom, satisfaction, and expectation scores were not significantly different between the ≤64-year-old patients and ≥65-year-old patients. The functional activities score was significantly lower in older patients than in younger patients. The overall survival rates of HTO were 99.1 ± 0.4% at 5 years, 94.4 ± 1.2% at 10 years, and 84.6 ± 2.7% at 15 years. There was no significant difference in the survival rate after HTO between the two groups divided by the age (p = 0.602).

CONCLUSIONS

Pain relief and satisfaction after HTO in older patients were comparable to those in younger patients in the mid-term to long-term follow-up, although the functional activity was affected by age.