The effect of patient, provider and surgical factors on survivorship of high tibial osteotomy to total knee arthroplasty: a population-based study

Long-Term Outcomes and Prognostic Factors of Medial Open Wedge High Tibial Osteotomy for Medial Compartment Knee Osteoarthritis or Osteonecrosis

Background/Objectives: Medial open wedge high tibial osteotomy (MOWHTO) has led to favorable clinical results since the introduction of locking plates. Surgical indications, techniques, and postoperative alignment are crucial for achieving favorable clinical outcomes. This study analyzed the clinical outcomes of patients after >5 years of post-MOWHTO follow-up to identify the influential factors. Methods: Thirty-nine patients (48 knees) underwent MOWHTO for medial compartment knee osteoarthritis or -necrosis and were followed up for >5 years. The targeted postoperative % mechanical axis (%MA) was 62.5% (Fujisawa point). The Japanese Orthopaedic Association (JOA) Knee Disease Outcome Criteria score; Kellgren-Lawrence classification; hip-knee-ankle, medial proximal tibial, mechanical lateral distal femoral, and joint line convergence angles (JLCA); and %MA were evaluated preoperatively, at implant removal, and at the final follow-up. Total knee arthroplasty (TKA) was the survival endpoint. Uni- and multivariate analyses were performed to identify the factors influencing survival rates. Results: The mean JOA score improved from preoperative to implant removal and was sustained at 102 months. Four of the 48 knees required TKA, resulting in a 10-year survival rate of 82%. Body mass index, preoperative JLCA, and Δ%MA influenced the post-MOWHTO survival rate. The Δ%MA was significantly greater in the group with a %MA < 62.5% at implant removal. Conclusions: MOWHTO with a target %MA of 62.5% yielded favorable long-term outcomes. Additionally, preoperative obesity and high joint instability negatively influenced post-MOWHTO survival. Furthermore, a postoperative %MA of < 62.5% is associated with difficulty maintaining stable alignment and an increased risk of conversion to TKA.

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

IMPORTANCE

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

AIM OR OBJECTIVE

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

EVIDENCE REVIEW

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

FINDINGS

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

CONCLUSIONS AND RELEVANCE

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

LEVEL OF EVIDENCE

Level 4.

Higher conversion rate to knee arthroplasty in female patients following medial open-wedge high tibial osteotomy

PURPOSE

Most studies about medial open-wedge high tibial osteotomy (HTO) reported outcomes without focusing on gender differences. Therefore, the study compared the long-term survival rate and postoperative subjective knee function after HTO in female versus male patients with symptomatic medial compartment knee osteoarthritis.

METHODS

The data of three cohorts with long-term outcomes were analysed (n = 245; 32% females; age: 49 ± 7 years; Kellgren Lawrence Grade I 6.1%, II 32.7%, III 42.4%; IV 18.8%). The minimum follow-up was at least 6 years or an earlier conversion to total knee arthroplasty (TKA). The gender-specific survival rate after HTO was calculated after 5 and 10 years and compared using Kaplan-Meier analysis and the logrank test. Baseline characteristics and subjective knee function (International Knee Documentation Committee [IKDC]/Lysholm) were analysed between both genders.

RESULTS

Forty of 78 (51.3%) women and 41 of 167 men (24.5%) underwent TKA. HTO survival in females was significantly lower (p = 0.0010). The 5- and 10-year survival rates were 85.9% and 62.6% for females and 93.4% and 77.7% for males. In females and males, from preoperative to the last follow-up, the IKDC (43 ± 15 to 58 ± 17; 47 ± 14 to 67 ± 18) and the Lysholm (42 ± 18 to 72 ± 18; 55 ± 22 to 77 ± 23) improved significantly (all p < 0.0001). Females had significantly lower preoperative and postoperative IKDC (p = 0.0438; p = 0.0035) and Lysholm scores (p = 0.0002; p = 0.0323). But the absolute improvements of the IKDC and Lysholm were not significantly different between genders.

CONCLUSIONS

Females had higher conversion rates to TKA and lower knee function at the last follow-up. However, preoperative knee function was lower in females and the absolute improvement following HTO was similar for both genders. In general, females benefit from HTO to treat medial knee arthritis, and TKA could be postponed for half of female patients for more than 10 years. However, surgeons must be aware of the described inferior outcomes in females for realistic patient expectation management.

LEVEL OF EVIDENCE

Level II.

Long-term Outcomes after Medial Open Wedge High Tibial Osteotomy - A Retrospective Study of 69 Patients

High tibial osteotomy (HTO) is a widespread option to avoid or delay total knee arthroplasty (TKA). The present study aimed to assess the long-term survival rate and postoperative subjective knee function after isolated medial open wedge HTO in patients with symptomatic medial compartment knee osteoarthritis (OA) and varus malalignment.Sixty-nine patients (48.8 ± 6.7, 35-66 years; preoperative mechanical tibiofemoral angle [mTFA] -5.3 ± 3.4; -14.9-0.0° varus) treated with medial open wedge HTO using a TomoFix plate were included in this retrospective study, with a follow-up of at least 10 years (11.8 ± 1.0 years). The survival rate after HTO was calculated after 5 and 10 years. Subjective knee function was assessed using Hospital for Special Surgery (HSS), Oxford knee, Lequesne, and Lysholm scores.Thirty-three patients underwent conversion to TKA, on average, 7.0 ± 3.4 (1.3-13.7) years after HTO. Five- and ten-year survival rates were 84.1 and 60.9%, respectively. Patients without conversion to TKA showed a Lysholm score of 64.5 (35-92), Lequesne score of 7 (1-13), HSS score of 71 (56-86), and Oxford knee score of 38.5 (25-44) at the last follow-up (more than 10 years). Significantly higher scores were registered at the last follow-up compared to the preoperative state regarding the Lysholm score (preoperative: 43.5 [12-95]; follow-up: 64.5 [35-92]; p < 0.001). The HSS score (preoperative: 69.5 [43-93]; follow-up: 71 [56-86]; p = 0.6941) showed no statistically significant change during the 10-year follow-up period. The Lequesne score was significantly lower than the preoperative score (preoperative: 11.5 [0.5-22]; follow-up: 7 [1-13]; p < 0.001), indicating a lower handicap.The majority of patients with a valgus medial compartmental knee OA treated with HTO with fixation using the TomoFix plate can expect no conversion to TKA for more than 10 years. Furthermore, patients without conversion to TKA after 10 years still had a significantly higher subjective knee function than preoperatively. Further research is needed to identify risk factors for conversion to TKA. This helps to guide surgeons in selecting patients who will benefit most from HTO.

Return to Duty in Military Servicemembers After High Tibial Osteotomy Not Associated With Preoperative Radiographic Parameters : A Retrospective Analysis

Background

Evidence on return to sports/work after high tibial osteotomy (HTO) is limited, especially in a young, high-demand population.

Purpose

To (1) identify whether preoperative knee pathology or intraoperative correction was associated with successful return to duty (RTD) and (2) assess whether postoperative complications and reoperation were associated with failure to RTD.

Study Design

Case series; Level of Evidence, 4.

Methods

We performed a retrospective cohort study of a consecutive series of patients in the Military Health System aged 18 to 55 years with medial compartment osteoarthritis who underwent HTO between 2003 and 2018. Concomitant meniscal and cartilage procedures were included, while cases with concomitant ligamentous procedures were excluded. The inclusion criteria were as follows: active-duty military status, minimum 2-year follow-up, preoperative knee radiographs, and pre- and postoperative long-leg alignment radiographs. Preoperative Kellgren-Lawrence grades and pre- and postoperative hip-knee-ankle angles were measured. The primary outcome was RTD. Failure was defined as knee-related medical separation from the military or conversion to total knee arthroplasty. The secondary outcome was reoperation.

Results

A total of 55 HTOs were performed in 50 patients who met the inclusion criteria, with a mean age of 39 years old (range, 22.8-55 years). The mean follow-up was 5 years (range, 2.1-10.7 years). Ten knees (18.2%) failed HTO (1 conversion to total knee arthroplasty, 9 medical separations), 15 additional knees (27.3%) had permanent activity restrictions, and 30 knees (54.5%) returned to duty without restrictions. Reoperation occurred in 36.4% of knees and was associated with medical separation (P = .039). Younger age was associated with medical separation (P = .003) and permanent restrictions (P = .006). Patients with a postoperative varus deformity of >5° were more likely to undergo medical separation (P = .023).

Conclusion

In a young, high-demand population, HTO succeeded in returning 54.5% of knees to full duty without restriction despite 36.4% of knees requiring reoperation. Residual varus deformity or reoperation was associated with lower RTD rates. No association was identified between RTD and preoperative osteoarthritis grading or deformity.

Clinical and radiological results of high tibial of osteotomy over the age of 65 are comparable to that of under 55 at minimum 2-year follow-up: a propensity score matched analysis

PURPOSE

The results of medial open-wedge high tibial osteotomy (MOWHTO) according to age is inconclusive. This study aimed to compare the clinical outcomes and failure of MOWHTO in patients < 55 years and > 65 years.

METHODS

Consecutive patients who underwent MOWHTO from July 2009 to August 2020 were retrospectively analyzed. 205 patients were considered for analysis. A 1-to-1 propensity score matched analysis to assess clinical outcomes scores including International Knee Documentation Committee (IKDC) subjective score and Lysholm score, radiologic outcomes, complication, and Total Knee Arthroplasty (TKA) conversion between patients > 65 years and patients < 55 years was performed. Radiologic outcomes included Hip-Knee-Ankle (HKA) angle, Weight Bearing Line ratio (WBLR), posterior tibial slope (PTS), and Insall-Salvati (IS) ratio before and after surgery.

RESULTS

The follow-up period was 50.4 months in patients > 65 years and 55.3 months in patients < 55 years. There was no significant difference in the preoperative and postoperative HKA angle, WBLR, PTS, IS ratio, IKDC score and Lysholm score between the two groups. The arthroscopic evaluation of cartilage did not show any statistically significant differences between the two groups. Regarding Minimal clinically important differences (MCID), in the 26% of the older group exceeded MCID of IKDC score; 45% of the older group exceeded MCID of Lysholm score. In the younger group, 24% exceeded MCID of IKDC score and 35% exceeded MCID of Lysholm score. In older group, there were 7 (11.3%) cases of TKA conversion while no TKA conversion was recorded in the younger group. (P = 0.007) The average time to TKA conversion was 67 months. (42 months to 90 months) Kaplan-Meier analysis revealed that the survival rate was 95.2% at 4 years in the older group.

CONCLUSION

Similar clinical results were obtained in patients over 65 years of age that were eligible for MOWHTO at minimum 2-year follow-up as in patients under 55 years of age. MOWHTO may be a viable option in older patients if proper indications are met. However, the risk of TKA conversion must be considered preoperatively and discussed with patients.

STUDY DESIGN

Cohort study; Level of evidence, 3.

High tibial osteotomy is equally effective for varus malaligned knees with either virgin or wrecked medial meniscus: An age and gender-matched secondary analysis of a Francophone Arthroscopy Society Symposium

INTRODUCTION

Despite the growing concept of meniscal preservation, partial meniscectomy could be the definitive procedure in specific scenarios. And total meniscectomy was once before a frequent procedure, with current sequelae of degenerate knees. High tibial osteotomy (HTO) is an effective treatment for patients suffering from unicompartmental degenerative changes, and substantial deformities. However, it is yet to be answered, whether HTO is similarly effective in both post-meniscectomy knees and knees with not previously operated meniscus.

HYPOTHESIS

Outcomes of HTO is similar with or without previous history of total or subtotal meniscectomy.

METHODS

This study compared the clinical and radiological outcomes of 41 patients who received HTO and had no previous history of surgery in the ipsilateral knee (group I), and 41 age, and gender-matched patients who had meniscectomy surgery in the ipsilateral knee (group II). Preoperatively and postoperatively, all patients were clinically evaluated; the visual analogue scale scores, Tegner activity score, and the Western Ontario and Macmaster University scores were reported. Radiographically, osteoarthritis grade and pre- and postoperative parameters were reported, including hip-knee-ankle angle, femoral mechanical angle, medial proximal tibial angle, joint line convergence angle, proximal posterior tibial angle, and limb length discrepancy. Perioperative details and complications were reported.

RESULTS

A total of 82 patients were included; group I (n=41) and group II (n=41). The mean age was 51.18±8.64 (27-68) and 90.24% were male. The duration since the onset of symptoms was longer in group II vs. group I, 43.34±41.03 versus 38.07±36.11months respectively. No significant differences in the clinical evaluation between the two groups with a greater proportion of patients demonstrating moderate degenerative changes. Similar preoperative and postoperative radiographic parameters were reported, in group I, Δ HKA was 7.19±4.14 versus 7.65±3.16 in group II. Preoperative pain VAS scores were slightly higher in group II vs. group I, 79.23±26.35 vs. 76.31±24.45, respectively. However, postoperatively, the pain scores significantly improved in group I vs. group II, 22.84±3.65 vs. 41.69±17.33, respectively. Tegner activity scores and WOMAC scores were comparable between both groups preoperatively and postoperatively. Only the WOMAC function scores were better in group I when compared to group II, 26.13±25.84 versus 20.01±17.98. All patients returned to work at an average of 0.82±0.38months.

CONCLUSION

Knee preservation with high tibial osteotomy is equally effective in managing unicompartmental degenerative changes in varus malaligned knees with either no previous history of meniscal surgeries or where a meniscal sacrifice was inevitable, either with subtotal or total meniscectomy.

LEVEL OF EVIDENCE

III, retrospective case-control study.

Effect of Patient Age on Clinical and Radiological Outcomes After Medial Open-Wedge High Tibial Osteotomy: A Comparative Study With 344 Knees

Background

There exists some controversy regarding whether patient age is a predictive factor for outcomes after high tibial osteotomy (HTO).

Purpose/Hypothesis

The purpose of this study was to evaluate whether patient age affects clinical and radiological outcomes after medial open-wedge HTO (OWHTO) in a large population with a wider age range than previous studies. It was hypothesized that there would be no differences in outcomes when compared across age-groups.

Study Design

Cohort study; Level of evidence, 3.

Methods

A retrospective comparative study was conducted using 344 patients (303 knees) who underwent OWHTO from 2009 to 2018. These patients were divided into 3 groups based on age at the time of surgery: ≥55 years (group Y: 76 knees in 57 patients), 56 to 64 years (group M: 129 knees in 120 patients), and ≤65 years (group O: 139 knees in 126 patients). Clinical and radiological evaluations were performed immediately before surgery and at the final follow-up period, at a mean of 5.1 years (range, 3-11 years). Comparisons among the 3 groups were conducted with 1-way analysis of variance for continuous variables. When a significant result was obtained, a post hoc test with Bonferroni correction was conducted for multiple comparisons.

Results

In clinical evaluations, there were no significant differences among the 3 groups either preoperatively or postoperatively concerning the Japanese Orthopaedic Association score, the Lysholm score, or the Knee injury and Osteoarthritis Outcome Score (KOOS), with the exception of the preoperative KOOS Symptoms subscale, which was significantly higher in group Y versus group O (48.9 ± 18.7 vs 58.7 ± 15.4, respectively; P = .011). The Tegner activity score was significantly different among the groups, both preoperatively and postoperatively (P < .001 for both). There was no significant difference in the occurrence of complications or the survival rate at final follow-up among the 3 groups.

Conclusion

The study findings suggest that patient age does not affect clinical and radiological outcomes after OWHTO.

Total knee arthroplasty post-high tibial osteotomy, results of an early experience from a North African arthroplasty unit, and a comprehensive review of the literature

PURPOSE

To report an early experience after converting HTO to TKA by reporting the incidence of functional, radiological, and complications in a single surgeon case series from a North African specialized arthroplasty unit.

METHODS

Between 2010 and 2020, 33 knees in 31 patients (two bilateral) were operated upon, 24 females and seven males, had a mean age of 65 ± 4.5 years; 17 (51.5%) knees had medial wedge opening (WMO), while 16 (48.5%) had lateral wedge closure (LWC) osteotomies. The mean time from HTO to TKA was 8.1 ± 3.3 years. A posterior stabilized (PS) implant was used in 31 (93.9%), while in 2 (6.1%), a varus-valgus constrained (VVC) implant was used. A tibial stem was needed in 13 (39.4%) knees. The functional assessment was performed according to the Knee Society Scoring System (KSS). The radiographic assessment included the anatomical femorotibial angle (aFTA) for alignment, the medial proximal tibial angle (MPTA), and the tibial slope (TS).

RESULTS

After a mean follow-up of 4.3 ± 1.1 years, the KSS knee and function sub-scores improved from a preoperative mean of 41 ± 8.9 (26 to 57) and 37.7 ± 9.2 (25 to 55) points to 91.3 ± 3.8 (81 to 94) and 85.5 ± 5 (80 to 95) points at the last follow-up, respectively (P < 0.05). The preoperative knee flexion improved from a mean of 84.5° ± 15.9 (55 to 110) to 110.6° ± 9.3 (95 to 125) (P < 0.05). The aFTA improved from a preoperative mean of 182.2° ± 10.3 (164 to 205) to a postoperative mean of 186° ± 2.6 (179 to 190) (P < 0.05). The MPTA changed from a preoperative mean of 88.4° ± 6.7 (77 to 102) to a postoperative (tibial component alignment) mean of 90° ± 1.7 (85 to 94) (P < 0.05). The mean preoperative TS changed from 80.9° ± 7.3 (68 to 96) to a mean postoperative of 86.9° ± 1.3 (83 to 89) (P < 0.05). Non-progressive radiolucent lines were detected at the tibial component in four (12%) knees. Complications were reported in seven (21.2%) knees; no revision was needed in any knee.

CONCLUSIONS

The authors' early experience showed improved functional and radiological outcomes; however, the complication incidence was relatively high, but no knees required revision. A longer follow-up is mandatory to prove the consistency of the results.

Decision regret following opening wedge high tibial osteotomy: Older age as a risk factor

BACKGROUND

Understanding risk factors that can predict decision regret after surgical procedures can potentially increase the quality of patient decision making and reduce decision regret after opening wedge high tibial osteotomy (OWHTO). The purpose of the present study was to identify the risk factors that predict the likelihood of decision regret after OWHTO.

METHOD

Questionnaires were administered to 98 eligible OWHTO recipients more than one year post-operatively. They answered "Yes" or "No" to the question "Would you go for the same choice (OWHTO) if you had to do it over again?" Univariate and multivariate logistic regression analyses were conducted using the decision regret questionnaire as the dependent variable against patient characteristics and surgery related factors. A receiver operating characteristic curve and area under the curve were constructed and calculated for age at surgery. Cut-off values were determined using the Youden principle and receiver operating characteristic curves.

RESULTS

Among the 98 respondents, 18 (18%) reported regretting their decision. Older age at surgery was the only predictive risk factor for decision regret (P < 0.01). The area under the curve for the model using age to predict failure was 0.722. The cut-off value was 71 years. Patients aged 71 years or more had a 7.841 odds ratio for decision regret (P < 0.01).

CONCLUSIONS

Older age emerged as a predictive risk factor for decision regret after OWHTO. Patients aged 71 years or older had a higher decision regret rate after OWHTO than younger patients and should more carefully weigh the suitability of OWHTO against other options.

Comparing Unicompartmental Knee Arthroplasty and High Tibial Osteotomy for Isolated Medial Compartment Knee Osteoarthritis

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Both unicompartmental knee arthroplasty (UKA) and high tibial osteotomy (HTO) allow for compartment-specific intervention on an arthritic knee joint that preserves bone stock and native soft tissue compared to a total knee arthroplasty (TKA). Both operations give a more natural feeling with native proprioception compared with a TKA.

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HTO is better suited in patients who are younger (<55 years-of-age), have a body mass index (BMI) <30 kg/m2, high activity requirements, mechanical malalignment, asymmetric varus, isolated anterior cruciate ligament insufficiency, need for multiplanar correction, and a preference for joint preserving interventions. Recent data suggest that age (>55 years-of-age) should not solely contraindicate a HTO.

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UKA may be chosen in patients who are older (>55 years-of-age), low activity requirements, have a BMI <40 kg/m2, severe osteoarthritis with significant joint space narrowing, acceptable coronal alignment, symmetric varus, and patient preference for arthroplasty.

Unicompartmental knee arthroplasty in patients under the age of 60 years provides excellent clinical outcomes and 10-year implant survival: a systematic review : A study performed by the Early Osteoarthritis group of ESSKA-European Knee Associates section

PURPOSE

The purpose of the present study was to systematically review the clinical and functional outcomes following medial unicompartmental knee arthroplasty (UKA) in patients under the age of 60 years old.

METHODS

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, studies between 2012 and April 2022, on patients 18-60 years old who have had a unicompartmental knee replacement evaluating patient-reported outcomes measures (PROMs), were included. The Knee Society Scores (KSS) clinical score was considered the primary outcome. Pre- and post-operative range of motion (ROM), PROMs, complications and survival were recorded. Paired sample t testing was performed to compare the pre-operative with post-operative KSS.

RESULTS

Seventeen articles comprising 2083 unicompartmental arthroplasties were included. The follow-up range was between 1 and 15 years. In eligible studies, all reported outcomes were improved following UKA. The mean KSS clinical was significantly improved from 45.5 (SD: 9.6) pre-operatively to 89.4 (SD: 4.4) post-operatively (p = 0.0001). Mean implant survival ranged 86-96.5% at 10 years follow-up. There was no significant difference between mobile and fixed bearing in terms of ROM and KSS clinical. In total, 92 revisions and 7 re-operations with implant retention were reported.

CONCLUSION

Unicompartmental knee arthroplasty for medial osteoarthritis is a safe, reliable and effective treatment option for patients of 60 years or younger. It provides pain relief, satisfactory activity level, excellent clinical outcomes, and up to 96.5% implant survival at 10-year follow-up.

LEVEL OF EVIDENCE

IV.

A predictive score of high tibial osteotomy survivorship to help in surgical decision-making: the SKOOP score

INTRODUCTION

The high tibial osteotomy (HTO) survival rate is strongly correlated with surgical indications and predictive factors. This study aims to assess HTO survival in the long term, to determine the main predictive factors of this survival, to propose a predictive score for HTO based on those factors.

METHODS

This multicentric study included 481 HTO between 2004 and 2015. The inclusion criteria were all primary HTO in patients 70 years old and younger, without previous anterior cruciate ligament injury, and without the limitation of body mass index (BMI). The assessed data were preoperative clinical and radiological parameters, the surgical technique, the complications, the HKA (hip knee ankle angle) correction postoperatively, and the surgical revision at the last follow-up.

RESULTS

The mean follow-up was 7.8 ± 2.9 years. The HTO survival was 93.1% at 5 years and 74.1% at 10 years. Age < 55, female sex, BMI < 25 kg/m² and incomplete narrowing were preoperative factors that positively impacted HTO survival. A postoperative HKA angle greater than 180° was a positive factor for HTO survival. The SKOOP (Sfa Knee OsteOtomy Predictive) score, including age (threshold value of 55 years), BMI (threshold values of 25 and 35 kg/m²), and the presence or absence of complete joint line narrowing, have been described. If the scale was greater than 3, the survival probability was significantly lower (p < 0.001) than if the scale was less than 3.

CONCLUSION

A predictive score including age, BMI, and the presence or absence of joint line narrowing can be a helpful in making decisions about HTO, particularly in borderline cases.

LEVEL OF EVIDENCE

Retrospective cohort study.

New insight into the current study of high tibial osteotomy: A bibliometric analysis

BACKGROUND

To analyze global trends in focus and funding of research related to high tibial osteotomy (HTO) and to identify the 100 most cited articles in this field.

METHODS

A Web of Science search was used to identify HTO publications in English-language scientific journals from January 1967 till February 3th, 2021. Results were filtered to the 100 most cited articles by reading the abstract or full-text paper. Information of these articles was recorded for further analysis. The 10 top-cited articles during the last 5 years and the 10 top-cited articles about HTO ranked by average citations per year were selected to predict research trends.

RESULTS

In all, 48 out of the 100 top-cited articles were published between 2000 and 2010. The United States of America was the primary contributor (n = 29) followed by Germany (n = 17) and Japan (n = 11). The total number of citations per article ranged from 65 to 563, median 108, mean 135 (standard deviation = 84). The American Journal of Bone and Joint Surgery accounted for 23 out of the 100 top-cited articles. Koshino T was the most cited author (603 citations). The most frequently highlighted study theme was prognostic research. Patient-based clinical research was the dominant study design (85%). The majority of articles (48 out of 100) were level IV evidence with a mean of 141 (standard deviation = 97) citations. Top-cited articles in the last 5 years focused on open wedge osteotomy.

CONCLUSION

Technical optimization of open wedge osteotomy has emerged as the main area of research in HTO. More specifically, recent publications focus on the surgical technology, cartilage repair and new fixation devices. Besides, papers with a high level of evidence are needed for the development of HTO.

Mid- to Long-Term Outcomes After Medial Open-Wedge High Tibial Osteotomy in Patients With Radiological Kissing Lesion

Background:

Although medial open-wedge high tibial osteotomy (MOWHTO) is the treatment of choice for patients with mild to moderate osteoarthritis with varus malalignment, concerns about inferior outcomes in patients with preoperative radiological kissing lesion (RKL) remain.

Purpose:

To compare the mid- to long-term clinical and radiological results and survivorship after MOWHTO in patients with versus without preoperative RKL.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Included were 122 knees in patients who underwent MOWHTO with a medial locked plate and had minimum 5-year follow-up data. The mean age at surgery was 55.9 years (range, 38-65 years), and the mean follow-up was 7.5 years (range, 5-12.8 years). All patients had undergone second-look arthroscopy around 2 years after MOWHTO. The knees were divided into an RKL group (n = 17) and no-RKL group (n = 105) based on preoperative standing radiographs. The authors compared postoperative American Knee Society (AKS) knee and function scores, range of motion, and improvements in AKS scores between groups, as well as hip-knee-ankle angle, medial proximal tibial angle, and joint-line convergence angle from preoperatively to postoperatively. Also compared were the degree of cartilage regeneration between first- and second-look arthroscopy and the survival rate after index surgery.

Results:

Preoperative AKS scores were significantly lower in the RKL group versus the no-RKL group (AKS knee, 79.6 ± 7.5 vs 83.8 ± 3.9, P = .037; AKS function, 68.8 ± 9.3 vs 76.0 ± 5.1, P = .006). Likewise, postoperative AKS scores were significantly lower in the RKL group versus the no-RKL group (AKS knee: 91.3 ± 4.2 vs 94.4 ± 1.6, respectively, P = .008; AKS function: 90.0 ± 10.0 vs 97.6 ± 4.5, respectively, P = .007). However, all patients had excellent postoperative AKS knee and function scores (>80). Moreover, there were no between-group differences in pre- to postoperative improvement in AKS scores, postoperative radiological changes, or grade of cartilage regeneration. The survival rates in the RKL and no-RKL groups were 100% and 97.1%, respectively (P ≥ .999).

Conclusion:

Although the latest clinical scores were lower in the RKL group than in the no-RKL group, comparable results in postoperative clinical improvement, cartilage regeneration, and survivorship were observed in patients with RKL at mid- to long-term follow-up.

Basketball vs. Hockey-The Changing Face of Sport-Related Injuries in Canada

OBJECTIVE

To characterize and compare the incidence of basketball-related, soccer-related, and hockey-related injuries over a 10-year period.

DESIGN

Cohort analysis of sport-related injuries using multiple Ontario healthcare databases.

SETTING

Emergency department visits in Ontario, Canada.

PATIENTS

Any patient who sustained musculoskeletal injuries sustained while playing basketball, soccer, or hockey between 2006 and 2017 were identified.

ASSESSMENT OF RISK FACTORS

Sport of injury, age, sex, rurality index, marginalization status, and comorbidity score.

MAIN OUTCOME MEASURES

Annual Incidence Density Rates of injury were calculated for each sport, and significance of trends was analyzed by assessing overlap of 95% confidence intervals.

RESULTS

One lakhs eighty five thousand eighty hundred sixty-eight patients (median age: 16 years, interquartile range 13-26) received treatment for sport-related injuries (basketball = 55 468; soccer = 67 021; and hockey = 63 379). The incidence of basketball-related and soccer-related injuries increased from 3.4 (3.3-3.5) to 5.6 (5.5-5.7) and 4.4 (4.3-4.5) to 4.9 (4.8-5) per 10 000 person years, respectively, whereas the incidence of hockey-related injuries decreased from 4.7 (4.6-4.8) to 3.7 (3.6-3.8). Patients with basketball injuries were more marginalized (3.01 ± 0.74) compared with patients with soccer and hockey injuries (2.90 ± 0.75 and 2.72 ± 0.69, respectively).

CONCLUSIONS

Accurate regional epidemiologic information regarding sports injuries can be used to guide policy development for municipal planning and sport program development. The trends and demographic patterns described highlight general and sport-specific injury patterns in Ontario. Populations with the highest incidence of injury, most notably adolescents and men older than 50, may represent an appropriate population for injury risk prevention.

Accuracy of the correction achieved after a valgus high tibial osteotomy: Comparison of the Hernigou table and navigation

INTRODUCTION

The outcome of a medial opening wedge valgus high tibial osteotomy indicated for the treatment of isolated medial tibiofemoral osteoarthritis depends mainly on the accuracy of the correction of the hip-knee-ankle angle (HKAA) and the mechanical medial proximal tibial angle (mMPTA). Most authors aim for a desired correction target between 2° and 4° of valgus. Several planning and surgical techniques have been described to achieve this target value that is specific to each surgeon.

OBJECTIVE

The purpose of this study was to compare the accuracy of the correction achieved using either the Hernigou table (HT) planning method or a computer-assisted navigation system (CAS). It was hypothesized that no difference would be found between these 2 techniques.

MATERIALS AND METHODS

This retrospective single-center study involved 43 knees: 21 in the HT group and 22 in the CAS group. Two surgeons (ME, JYJ), who were experts in 1 of the 2 planning methods performed these procedures, with a single surgeon assigned to each group. The correction was noted in the operative report and was considered to be the desired correction target. The surgical correction was calculated by comparing preoperative and immediate postoperative mMPTA measurements. The surgical accuracy, where a value close to 0 represented optimal accuracy, was defined as the absolute value of the difference between the correction target set by the surgeon and the surgical correction achieved. The median accuracy between the 2 groups was compared by a Mann-Whitney U test (significance level at 5%). The number of patients deviating from the target by>3° was analyzed with a Fisher exact test (significance level at 5%). Pre- and postoperative comparisons of the HKAA measurements could not be used because the measurement was not performed postoperatively for the CAS group.

RESULTS

The median surgical accuracy on the mMPTA was 1.4° (0-4.1) for the HT group versus 1.9° (0.2-6.7) for the CAS group (p=0.85). Sixteen procedures (76%) were performed with an accuracy of<3° in the HT group versus 15 in the CAS group (68%) (p=0.73).

DISCUSSION-CONCLUSION

The working hypothesis was confirmed: no differences were found between the HT and CAS groups regarding the surgical accuracy in achieving the corrections set in this series. We therefore demonstrated that HT was a highly accessible, simple and reliable technique for achieving the planned target. It can be used widely.

LEVEL OF EVIDENCE

III; comparative retrospective series.

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.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

Level III.

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.

Medial Opening Wedge Proximal Tibial Osteotomy: Lessons Learned from a Series of 175 Consecutive Cases

INTRODUCTION

High tibial osteotomy (HTO) is a surgical procedure aimed at inhibiting the progression of osteoarthritis of the knee joint. The aim of this study was to identify factors influencing the functional outcome after opening wedge valgus HTO.

METHODS

A total of 175 cases (155 patients) of varus-correcting high tibial open-wedge osteotomies using the Tomofix plate were reviewed retrospectively. Patients answered the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire and 4 survey follow-up questions.

RESULTS AND DISCUSSION

A total of 76 of the 155 patients studied (84 of the 175 knees) completed the KOOS questionnaire, on average 3.1 years (SD 1.8 years) after the surgery. The median scores (with median absolute deviations [MAD]) for the KOOS pain, symptoms, daily activities, sports, and quality of life sections were, respectively, 76.4 (MAD 12.5), 75.0 (MAD 14.3), 85.3 (MAD 11.8), 50.0 (MAD 25.0), and 59.4 (MAD 21.9). No cases of nonunion were observed throughout the length of the study. Identified predictors of worse outcomes were higher weight and body mass index, limited knee flexion, genu varum and tibial varus of small magnitude, active smoking status at the time of surgery, further surgery for plate removal, and some grades of chondropathy in the patellofemoral, medial tibial, and femoral compartments. Patient gender, joint obliquity and over- or undercorrection were not associated with any of the outcomes.

CONCLUSION

This study shows good results following valgus HTO that are comparable to outcomes following total knee arthroplasty, reinforcing the option of HTO as a valid alternative for total knee arthroplasty.

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.

Role of high tibial osteotomy in medial compartment osteoarthritis of the knee: Indications, surgical technique and outcomes

Knee osteoarthritis (OA) is the most common joint disorder worldwide. In particular, primary knee OA often presents with a varus malalignment. This increases the loads going through the medial compartment resulting in cartilage degeneration and symptomatic arthritis. High tibial osteotomy (HTO) is the workhorse surgical procedure for treating medial knee OA. When performed precisely in the hands of an experienced surgeon, HTO can delay or avoid knee arthroplasty. Of note, outcomes of knee arthroplasty are at best unpredictable in patients of younger age. Hence, there is a growing need for joint preservation procedures for younger patients presenting with knee OA, of which HTO is one. Through this article, the authors of whom all are joint preservation surgeons with a special interest in osteotomy hope to share from their experience as well as the available literature on the indications, perioperative planning, surgical technique, outcomes as well as pearls and pitfalls of HTO.

Editorial Commentary: Chronological Age Is Not Associated With Adverse Postoperative Outcomes After High Tibial Osteotomy: Contradiction of Another Dogma From the Past

Open wedge high tibial osteotomy (OWHTO) is an established treatment option for treating medial compartmental knee osteoarthritis with varus deformity. Among several factors associated with postoperative outcomes, patient age is immensely decisive in reconstructive knee joint surgeries, including OWHTO and total knee arthroplasty. Surprisingly, the direct effect of age on OWHTO outcomes is poorly defined in current clinical practice. Recent research comparing clinical and radiologic outcomes according to age was introduced, and the influential predictor determining OWHTO outcomes was cartilage status rather than age. In the future, when deciding its suitability, OWHTO should absolutely be considered as an attractive treatment even in elderly patients without highly advanced cartilage degeneration; advanced age should not be identified as a risk factor but rather a potential indication for OWHTO. However, a large-scale long-term follow-up study is necessary to elucidate these findings.

Cartilage Status, Rather Than Chronologic Age, Determines the Outcomes of Open Wedge High Tibial Osteotomy: A Cartilage Status-Matched Cohort Study

PURPOSE

To evaluate the true effects of chronologic age on the clinical and radiologic outcomes of open wedge high tibial osteotomy (OWHTO) in a sample of patients who had been matched according to cartilage status in the medial and lateral compartments.

METHODS

The records of 107 OWHTO cases were reviewed. To evaluate potential differences in the outcomes according to age, the subjects were divided into 2 groups by the median age: older group and younger group. The Hospital for Special Surgery scores and Knee Society objective and functional scores before surgery and at the latest follow-up were compared between the groups. Then, the subjects in each group were matched 1:1 according to cartilage status in the medial and lateral compartments, which had been evaluated during arthroscopy prior to the osteotomy. The clinical scores were compared between the matched groups. The change in the medial joint space width (ΔJSW) from 6 to 12 months postoperatively to the latest follow-up was also compared before and after matching.

RESULTS

With a median age of 55 years, 44 and 63 cases were allocated into the older and younger groups, respectively. Prior to cartilage status matching, the latest Hospital for Special Surgery and Knee Society functional scores were significantly higher in the older group (P = .042 and P = .025, respectively). After matching, each group included 41 cases, and the differences in these clinical scores were no longer significant (P = .164 and P = .165, respectively). No difference in ΔJSW was observed between the groups, regardless of matching status (P = .901 before matching, P = .979 after matching).

CONCLUSIONS

The clinical outcomes of OWHTO were affected by cartilage status, rather than by the chronologic age itself. No difference was observed in the radiologic outcome (ΔJSW) with respect to age. OWHTO should not be waived in treating elderly patients without highly advanced cartilage degeneration simply because of their chronologic ages.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Effect of concurrent repair of medial meniscal posterior root tears during high tibial osteotomy for medial osteoarthritis during short-term follow-up: a systematic review and meta-analysis

BACKGROUND

Medial meniscal posterior root tears (MMPRTs) are frequently associated with medial compartment osteoarthritis, leading to loss of meniscal hoop tension. This study aimed to evaluate the efficacy of concurrent MMPRT repair during high tibial osteotomy (HTO) compared to HTO alone in patients with medial osteoarthritis and MMPRTs.

METHODS

The MEDLINE/PubMed, EMBASE, and Cochrane Library databases were searched for studies reporting on concurrent MMPRT repair during HTO. Pre- and postoperative data were pooled to investigate the treatment effects of concurrent MMPRT repair during HTO, and compare postoperative clinical, radiological, and arthroscopic outcomes including cartilage status and healing event rates according to the arthroscopic classification of MMPRT healing (complete, partial [lax or scar tissue], or failed healing) between HTO patients with and without concurrent MMPRT repair. The random-effect model was used to pool the standardized mean differences, odds ratios (ORs), 95% confidence intervals (CIs), and event rates.

RESULTS

Seven patient subgroups in six articles divided according to meniscal repair techniques were included in the final analysis. Concurrent MMPRT repair during HTO significantly improved the Lysholm score, while no intergroup differences were observed in the postoperative Lysholm and WOMAC scores, as well as radiological and arthroscopic outcomes. Those who underwent concurrent MMPRT repair showed a higher rate of complete meniscal healing (OR: 4.792, 95% CI, 1.95-11.79), with a pooled rate of complete meniscal healing of 0.327 (95% CI, 0.19-0.46).

CONCLUSION

Concurrent MMPRT repair during HTO for medial osteoarthritis with MMPRTs has little benefits on the clinical, radiological, and arthroscopic outcomes during short-term follow-up. Further accumulation of evidence is needed for long-term effects.

[Axial deformities of the lower extremity in the frontal plane : From physiological development to pathological and possible long-term consequences]

BACKGROUND

From birth to the end of growth, leg axes undergo physiological changes. Congenital, idiopathic or secondary deformities of the lower extremities are considered as a pre-arthrosis. A detailed clinical examination is of primary importance. On the basis of the established preventive examinations, predominantly asymptomatic deformities can be distinguished from age-typical physiological axis deviations at an early stage.

THERAPY

There is a variety of conservative and surgical therapy options. In most cases, the spontaneous course of development can be waited for, depending on the deformity and the associated restrictions. It is important to recognize the right time for an intervention. Usually, surgical interventions are necessary, including guided growth by permanent and partial arrest of the growth plate or osteotomies. The aim is to restore the anatomical axial alignment and thus prevent the development of osteoarthritis. A missed intervention often leads to an early endoprosthetic replacement in adulthood.

Total knee replacement after high tibial osteotomy: time-to-event analysis and predictors

BACKGROUND

An important aim of high tibial osteotomy (HTO) is to prevent or delay the need for total knee replacement (TKR). We sought to estimate the frequency and timing of conversion from HTO to TKR and the factors associated with it.

METHODS

We prospectively evaluated patients with osteoarthritis (OA) of the knee who underwent medial opening wedge HTO from 2002 to 2014 and analyzed the cumulative incidence of TKR in July 2019. The presence or absence of TKR on the HTO limb was identified from the orthopedic surgery reports and knee radiographs contained in the electronic medical records for each patient at London Health Sciences Centre. We used cumulative incidence curves to evaluate the primary outcome of time to TKR. We used multivariable Cox proportional hazards analysis to assess potential preoperative predictors including radiographic disease severity, malalignment, correction size, pain, sex, age, body mass index (BMI) and year of surgery.

RESULTS

Among 556 patients who underwent 643 HTO procedures, the cumulative incidence of TKR was 5% (95% confidence interval [CI] 3%-7%) at 5 years and 21% (95% CI 17%-26%) at 10 years. With the Cox proportional hazards multivariable model, the following preoperative factors were significantly associated with an increased rate of conversion: radiographic OA severity (adjusted hazard ratio [HR] 1.96, 95% CI 1.12-3.45), pain (adjusted HR 0.85, 95% CI 0.75-0.96)], female sex (adjusted HR 1.67, 95% CI 1.08-2.58), age (adjusted HR 1.50 per 10 yr, 95% CI 1.17-1.93) and BMI (adjusted HR 1.31 per 5 kng/m2, 95% CI 1.12-1.53).

INTERPRETATION

We found that 79% of knees did not undergo TKR within 10 years after undergoing medial opening wedge HTO. The strongest predictor of conversion to TKR is greater radiographic disease at the time of HTO.

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.

Medium-term survival and clinical and radiological results in high tibial osteotomy: Factors for failure and comparison with unicompartmental arthroplasty

INTRODUCTION

High tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA) are two surgical solutions for isolated medial tibiofemoral osteoarthritis. Results depend on preoperative criteria and patient selection, but also on postoperative factors: implant positioning, limb alignment. Factors for HTO survival need identifying to reduce risk of failure requiring total knee arthroplasty (TKA).

HYPOTHESIS

Age, gender, weight, osteoarthritis grade, degree of correction, type of osteotomy, technique and intraoperative complications impact HTO survival.

MATERIAL AND METHOD

As part of a symposium of the French Society of Arthroscopy (SFA), a multicenter retrospective study compared 2 series. The HTO series comprised 488 patients: 153 female (31.4%); mean age, 55.1 years; mean weight, 83.1kg; mean body-mass index (BMI), 28.6. The UKA series comprised 284 patients: 172 female (60.6%); mean age, 64.1 years; mean weight, 75.3kg; mean BMI, 27.6. The main endpoint was comparative survival at 5, 8 and 10 years; secondary endpoints comprised pre- and post-operative hip-knee-ankle (HKA) angle, mechanical femoral angle (mFA) and mechanical tibial angle (mTA), surgical technique, satisfaction, time to and level of return to work, WOMAC and Tegner scores and complications rates. The significance threshold was set at p<0.05; 95% confidence intervals were calculated.

RESULTS

Age>54 years, male gender, BMI>25, medial tibiofemoral wear severity Ahlback ≥3, ≥0.9° varus joint component, HKA correction<8°, postoperative HKA<180° and hinge fracture were significantly associated with poorer survival. There was no impact of type of osteotomy, navigation assistance or postoperative HKA 183-186°. Ten-year survival was 74.3% for HTO and 71% for UKA (non-significant); however, survival curves crossed at 6 years.

CONCLUSION

HTO showed survival and functional results comparable to those of UKA in selected patients when target limb alignment correction was achieved. The present study determined selection criteria. A predictive score for results of either procedure would facilitate decision-making.

LEVEL OF EVIDENCE

IV, retrospective cohort study.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Accuracy of the correction obtained after tibial valgus osteotomy. Comparison of the use of the Hernigou table and the so-called classical method

INTRODUCTION

Medial valgus-producing tibial osteotomy (MVTO) is classically used to treat early medial femorotibial osteoarthritis. Long-term results depend on the mechanical femorotibial angle (HKA) obtained at the end of the procedure. A correction goal between 3 and 6° valgus is commonly accepted. Several planning methods are described to achieve this goal, but none is superior to the other.

OBJECTIVE

The main objective was to compare the accuracy of the correction obtained using either the Hernigou table (HT) or a so-called conventional method (CM) for which 1° of correction corresponds to 1° of osteotomy opening. The secondary objective was to analyze the variations observed in the sagittal plane on the tibial slope and on the patellar height. The working hypothesis was that the HT allowed a more accurate correction and that the tibial slope and patellar height were modified in both groups.

MATERIAL AND METHOD

In this monocentric and retrospective study, two senior surgeons operated on 39 knees (18 in the CM group, 21 in the HT group) between January 1, 2009 and December 31, 2014. The operator was unique for each group and expert in the technique used. The correction objective chosen for each patient, and written in the operative report, was considered as the one to be achieved. The surgical correction was the difference between the pre-operative and immediate post-operative data (< 5 J) for the mechanical tibial angle (MTA) and the hip-knee-ankle (HKA) angle. Surgical accuracy, where a value close to 0 is optimal, was the absolute value of the difference between the surgical correction performed and the goal set by the surgeon.

RESULTS

The median surgical accuracy on the MTA was 3.5° [0.2-7.4] versus 1.4° [0-4.1] in the CM and HT groups, respectively (p = 0.006). In multivariate analysis, with the same objective, the CM had a significantly lower accuracy of 1.9° ± 0.8 (p = 0.02). For HKA, the median accuracy was 3.1° [0.3-7.3] versus 0.8° [0-5] in the CM and HT groups, respectively (p = 0.006). Five (5/18, 28%) and 16 (16/21, 76%) knees were within 3° of the target in the CM and HT groups, respectively (p = 0.004). The median tibial slope increased in both groups. This increase was significantly greater in the CM group compared with the HT group, with 5.5° [- 0.3-13] versus 0.5 [- 5.2-5.6], respectively (p < 0.001). The median Caton-Deschamps index decreased (patella lowered) in both groups after surgery, by - 0.21 [- 1.03; - 0.05] and - 0.14 [- 0.4-0.16], but without significant difference (p = 0.19). In univariate analysis, changes in tibial slope and patellar height were not significantly related to frontal surgical correction performed according to ΔMTA (R² = 0.07; p = 0.055) and (R² = - 0.02; p = 0.54) respectively.

DISCUSSION

The correction set by the surgeons was achieved with greater accuracy and more frequently in the HT group, confirming the working hypothesis. The HT is therefore recommended as a simple way of achieving the set objective; the tibial slope and patellar height were modified unaffected by the frontal correction performed.

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.

Survival and Risk Factor Analysis of Medial Open Wedge High Tibial Osteotomy for Unicompartment Knee Osteoarthritis

PURPOSE

The purpose of this retrospective study was to evaluate the survival rates and analyze the factors that affect survival rate after primary treatment with medial open wedge high tibial osteotomy (MOWHTO) for medial unicompartmental knee osteoarthritis.

METHODS

Clinical evaluation using Knee Society Score (KSS) and Western Ontario and McMaster Universities Osteoarthritis Index score and radiographic evaluation, including mechanical axis, were done before and after surgery. The main failure criteria for survival included the conversion to total knee arthroplasty or KSS of <60 points. Furthermore, risk factors that affected the survival after MOWHTO were analyzed.

RESULTS

Three hundred thirty-nine knees were included after a minimum of 5 years' follow-up. Their mean age was 56 years, and mean follow-up duration was 9.6 years. The mean KSS and Western Ontario and McMaster Universities Osteoarthritis Index scores were significantly improved after surgery (87.3 and 18.5 points at 5 years and 81.7 and 23.6 points at 10 years). The mean hip-knee-ankle (HKA) angle was corrected from 7.2° varus to 3.4° valgus 1 year after surgery, which was maintained until 10 years after surgery (2.9° valgus at 5 years and 2.3° valgus at 10 years, P > .05). Using Kaplan-Meier survival estimates, the probability of survival for MOWHTO was 96.8% at 5 years, 87.1% at 10 years, and 85.3% at 13 years. The multivariate regression analysis revealed that age ≥65 years (hazard ratio [HR] = 2.34, P = .046), medial compartment cartilage damage International Cartilage Repair Society grade ≥4 (HR = 2.46, I = .045), lateral compartment cartilage damage International Cartilage Repair Society grade≥2 (HR = 3.38, P = .006), postoperative HKA angle <0° (HR = 4.69, P < .001) were associated with failure.

CONCLUSION

MOWHTO seems to be a good treatment option for young and active patients with medial knee osteoarthrosis and varus alignment, with acceptable survival rates and satisfactory outcomes. Age ≥65 years, grade 4 cartilage damage in medial compartment, grade ≥2 cartilage damage in lateral compartment, and undercorrection of HKA angle appear to be significant risk factors associated with failure.

LEVEL OF EVIDENCE

Level IV: retrospective case series.

Editorial Commentary: High Tibial Osteotomy for Varus Knees With Medial Osteoarthritis May Prevent Total Knee Arthroplasty

High tibial osteotomy for unilateral medial knee osteoarthritis unloads the osteoarthritic area, gives pain relief, and may prevent later osteoarthritis if performed for the ideal indications. The risk of conversion of high tibial osteotomy to total knee arthroplasty is higher if osteoarthritis has advanced too far and for overweight persons, cigarette smokers, older patients, female patients, patients with a high level of comorbidity, and patients with under-correction of the varus malalignment.

Effect of saw blade geometry on crack initiation and propagation on the lateral cortical hinge for HTO: Finite element analysis

INTRODUCTION

The hinge plays a primary role in the hold and healing of a high tibial osteotomy (HTO). Weakening of the hinge is a risk factor for failure. The aim of our study was to determine whether the geometry of the saw blade's cutting edge impacts crack initiation or propagation on the hinge.

HYPOTHESIS

A certain cutting edge geometry exists that will reduce this risk.

MATERIALS AND METHODS

A finite element model with transverse isotropic elastic bone properties was created. A 1.27-mm thick saw cut (full thickness in anteroposterior direction) was made leaving a 1cm lateral cortical hinge. Three different cutting edge geometries were compared: rectangular, U-shaped, V-shaped. Opening of the osteotomy was done over 1mm for 1 s by a load applied distally with the proximal portion fixed. In the first simulation, no crack was initiated at the hinge, while in the second simulation, the beginnings of a 2mm crack angled upward at 15° was added. These two simulations were used to identify whether a local stress riser was present at the hinge. This information was used to calculate the energy release rate to the hinge, which corresponds to the energy needed to initiate and propagate a crack on the hinge.

RESULTS

In the first simulation (no crack initiation), a rectangular saw blade geometry resulted in the lowest local stress concentration. In the second simulation (with crack initiation), the U-shaped geometry resulted in the lowest local stress concentration. The U-shaped geometry had the lowest energy release rate, meaning that it was the least likely to initiate and propagate a crack on the lateral cortical hinge.

DISCUSSION/CONCLUSION

Keeping the inherent limitations related to computer modelling in mind, our findings show that a U-shaped cutting edge is least likely to initiate or propagate a crack since it has the lowest energy release rate. This confirms our hypothesis.

LEVEL OF EVIDENCE

V, expert opinion.

Improved Methods to Measure Outcomes After High Tibial Osteotomy

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

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

Long-term survival is similar between closed-wedge high tibial osteotomy and unicompartmental knee arthroplasty in patients with similar demographics

PURPOSE

Long-term clinical and radiographic results and survival rates were compared between closed-wedge high tibial osteotomy (HTOs) and fixed-bearing unicompartmental knee arthroplasty (UKA) in patients with similar demographics.

METHODS

Sixty HTOs and 50 UKAs completed between 1992 and 1998 were retrospectively reviewed. There were no significant differences in pre-operative demographics. The mean follow-up period was 10.7 ± 5.7 years for HTO and 12.0 ± 7.1 years for UKA (n.s.). The Knee Society knee and function scores, WOMAC, and range of motion (ROM) were investigated. The mechanical axis and femorotibial angle were evaluated. Kaplan-Meier survival analysis was performed (failure: revision to TKA) and the failure modes were investigated.

RESULTS

Most of the clinical and radiographic results were not different at the last follow-up, except ROM; ROM was 135.3° ± 12.3° in HTO and 126.8° ± 13.3° in UKA (p = 0.005). The 5-, 10-, 15-, and 20-year survival rates were 100%, 91.0%, 63.4%, and 48.3% for closed-wedge HTO, respectively, and 90.5%, 87.1%, 70.8%, and 66.4% for UKA (n.s.). The survival rate was higher than that for UKA until 12 years post-operatively but was higher in UKAs thereafter, following a remarkable decrease in HTO. The most common failure mode was degenerative osteoarthritic progression of medial compartment in HTO and femoral component loosening in UKA.

CONCLUSIONS

Long-term survival did not differ significantly between closed-wedge HTO and fixed-bearing UKA in patients with similar pre-operative demographics and knee conditions. The difference in post-operative ROM and failure mode should be considered when selecting a procedure.

LEVEL OF EVIDENCE

III.

Long-term results of fresh osteochondral allografts and realignment osteotomy for cartilage repair in the knee

AIMS

The aim of this study was to report the outcome of femoral condylar fresh osteochondral allografts (FOCA) with concomitant realignment osteotomy with a focus on graft survivorship, complications, reoperation, and function.

PATIENTS AND METHODS

We identified 60 patients (16 women, 44 men) who underwent unipolar femoral condylar FOCA with concomitant realignment between 1972 and 2012. The mean age of the patients was 28.9 years (10 to 62) and the mean follow-up was 11.4 years (2 to 35). Failure was defined as conversion to total knee arthroplasty, revision allograft, or graft removal. Clinical outcome was evaluated using the modified Hospital for Special Surgery (mHSS) score.

RESULTS

A total of 14 grafts (23.3%) failed at a mean of 8.6 years (1.4 to 20.1). Graft survivorship was 87.3% (95% confidence interval (CI) 79.0 to 96.6), 85.0% (95% CI 75.8 to 95.3), 74.8% (95% CI 62.2 to 90.0), 65.2% (95% CI 49.9 to 85.2), and 59.8% (95% CI 43.5 to 82.1) at five, ten, 15, 20, and 25 years, respectively. A total of 23 patients (38.3%) developed complications, and 26 (43.3%) had a further operation. Persistent postoperative malalignment occurred more frequently in failed grafts (28.6% vs 4.3%; p = 0.023), and was a risk factor for graft failure (hazard ratio 6.55; 95% CI 1.61 27.71; p = 0.009). The mean mHSS score improved from 74.1 (40 to 91) preoperatively to 89.0 (66 to 100) at final follow-up (p < 0.001).

CONCLUSION

Femoral condylar FOCA with concomitant realignment osteotomy provides excellent long-term graft survival and reliable functional improvement. Persistent malalignment may increase the risk for graft failure.

Older age and female gender are independent predictors of early conversion to total knee arthroplasty after high tibial osteotomy

BACKGROUND

The primary aim was to assess survival of opening wedge high tibial osteotomy (HTO) for medial compartment osteoarthritis. The secondary aim was to identify independent predictors of early conversion to total knee arthroplasty (TKA).

METHODS

During the 18-year period (1994-2011) 111 opening wedge HTO were performed at the study centre. Mean age was 45 years (range 18-68) and the majority male (84%). Mean follow-up was 12 (range six to 21) years. Failure was defined as conversion to TKA. Kaplan-Meier, Cox regression and receiver operating curve (ROC) analyses were performed.

RESULTS

Forty (36.0%) HTO failed at a mean of 6.3 years (range one to 15). By Kaplan-Meier analysis, the five-year survival rate was 84% (95% confidence interval (CI) 82.6-85.4), 10-year rate 65% (95% CI 63.5-66.5) and 15-year rate 55% (95% CI 53.3-56.7). Cox regression analysis identified older age (hazard ratio (HR) 1.07 for each additional year, 95% CI 1.03-1.11, p b 0.001) and female gender (HR 2.37, 95% CI 1.06-5.33, p = 0.04) as independent predictors of failure. ROC analysis identified a threshold age of 47 years above which the risk of failure increased significantly (area under curve 0.72, 95% CI 0.62-0.81, p b 0.001). Cox regression analysis, adjusting for covariates, identified a significantly greater (HR 2.49, 95% CI 1.26-4.91, p = 0.01) risk of failure in patients aged 47 years old or more.

CONCLUSION

The risk of early conversion to TKA is significantly increased in females and those older than 47. These risk factors should be considered pre-operatively when planning intervention for isolated medial compartment osteoarthritis.

[Positive and negative predictors of long-term results after an osteotomy around the knee joint]

A frequently asked question in the context of any surgical procedure, including an osteotomy around the knee joint, is "which parameters are in favor of a therapeutic success in this special case?" If the analysis of the leg geometry is in favor of an osteotomy, then the patient must be assessed further, taking into account the joint status and patient's condition. Positive outcome predictors for long-term success of an osteotomy around the knee, especially for a valgus osteotomy at the tibia are a tibial bone varus angle (TBVA) > 3-5°, knee joint range of motion > 100° flexion, male sex, and a BMI < 30. It is unclear whether the degree of degeneration of the affected (medial) compartment is of special relevance. The severity of malalignment, the patient's sex, and psychopathological comorbidities are not important.

Subtubercle Osteotomy for Medial Compartment Osteoarthritis of the Knee Using Ilizarov Technique: Survival Analysis and Clinical Outcomes

BACKGROUND

High tibial osteotomy with acute correction and internal fixation can be used to correct malalignment and malorientation and reduce symptoms in patients with medial compartment osteoarthritis of the knee. To address the inadequacies of this technique, we performed a series of subtubercle tibial osteotomy (STO) procedures using circular ring fixation to correct knee varus malalignment and joint malorientation. The purpose of this study was to analyze the ability of this technique to delay subsequent knee arthroplasty and decrease symptoms.

METHODS

Sixty-one patients had a total of 72 STO procedures using the Ilizarov technique to correct a varus deformity of the proximal part of the tibia. Radiographic measurements were performed at the time of presentation and after osseous union and frame removal. Clinical and radiographic variables were compared from presentation to the time of the latest follow-up. We performed a survival analysis, and our primary outcome was the time to conversion to knee arthroplasty.

RESULTS

Radiographic measurements, including mechanical axis deviation, medial proximal tibial angle, and joint line congruence angle, significantly improved after deformity correction (p < 0.001 for all). In patients with a preoperative flexion contracture, the proximal posterior tibial angle significantly increased toward normal values (mean, 77.8° pretreatment versus 82.4° posttreatment; p = 0.007). Survival analysis demonstrated a rate of native knee-joint survival without conversion to arthroplasty of 94.2% (95% confidence interval [CI], 83% to 98%) at 5 years, 84.0% (95% CI, 69% to 92%) at 10 years, and 51.3% (95% CI, 28% to 71%) at 15 years. In addition, time-trade-off and Brief Pain Inventory outcomes significantly improved (p < 0.001). The complication rate was 8%.

CONCLUSIONS

STO procedures using the Ilizarov technique for symptomatic varus knee deformity, performed over the course of 18 years, resulted in high knee survival rates without arthroplasty and significant improvement in clinical status. The STO technique provides several advantages over acute correction with internal fixation through a conventional high tibial osteotomy, including maintenance of the patellofemoral relationship, no retained implants, and accurate coronal and sagittal plane corrections.

LEVEL OF EVIDENCE

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

Changes in biomechanical risk factors for knee osteoarthritis and their association with 5-year clinically important improvement after limb realignment surgery

OBJECTIVE

To evaluate 5-year outcomes after lower limb realignment and test the hypothesis that surgery-induced changes in selected biomechanical risk factors for medial knee osteoarthritis (OA) are associated with clinically important improvements.

DESIGN

We prospectively evaluated patient-reported outcomes, full-limb standing radiographs and gait biomechanics before, 6 months (surgery-induced change) and 5 years after medial opening wedge high tibial osteotomy (HTO) in 170 patients (46.4 ± 8.9 years, 135 males) with knee OA and varus alignment. Logistic regression tested the associations of 6-month changes in mechanical axis angle and knee adduction moment with achieving an increase of ≥10 points in the Knee injury and Osteoarthritis Outcome Score (KOOS)4 at 5 years, with and without adjusting for covariates. Gait data were also compared to existing data from healthy controls.

RESULTS

Mean 5-year changes (95% confidence interval (CI)) were: KOOS4: +14.2 (10.8, 17.6); mechanical axis angle: +8.21° (7.58, 8.83); knee adduction moment: -1.49 %BW*Ht (-1.35, -1.63). The postoperative knee adduction moments were typically lower than values for healthy controls. When divided into quartiles, although all strata improved significantly, patients with reductions in knee adduction moment of 1.14-1.74 %BW*Ht (neither largest nor smallest changes) had highest 5-year KOOS4 scores. The 6-month change in knee adduction moment (odds ratios (OR) = 0.38; 95% CI: 0.22, 0.67), preoperative KOOS4 (OR = 0.96; 95% CI: 0.94, 0.99) and preoperative medial tibiofemoral narrowing grade (OR = 0.62; 95% CI: 0.37, 1.00) were negatively associated with having a 5-year clinically important improvement (C-statistic = 0.70).

CONCLUSIONS

Substantial improvements in biomechanical risk factors and patient-reported outcomes are observed 5 years after medial opening wedge HTO. The surgery-induced change in load distribution during walking is significantly associated with long-term clinically important improvement.

Progression of medial compartmental osteoarthritis 2-8 years after lateral closing-wedge high tibial osteotomy

PURPOSE

The primary purpose of this study is to investigate the progression of medial osteoarthritis (OA) following lateral closing-wedge high tibial osteotomy (HTO). Secondary outcomes included functional and pain scores.

METHODS

This prospective cohort study analysed 298 patients treated with lateral closing-wedge HTO surgery for medial compartmental OA. OA progression was measured by comparing the minimum joint space width (mJSW) and Kellgren-Lawrence (KL) score on radiographs preoperatively and postoperatively. The WOMAC score and NRS score for pain were obtained preoperatively and postoperatively to assess secondary outcomes. Failure was defined as revision surgery; survival was estimated.

RESULTS

Mean follow-up was 5.2 ± 1.8 years (range 2-8.5). Mean preoperative mJSW was 3.4 ± 1.6 mm, which changed nonsignificantly (p = 0.51) to 3.4 ± 1.7 mm postoperatively. Mean annual joint space narrowing was 0.02 ± 0.34 mm/year. Progression to 1 KL grade or more was seen in 132 (44 %) patients, and annual risk of KL progression was 8.6 %. No KL progression was seen in 56 % of patients. Mean NRS decreased from 7.3 ± 1.5 to 3.5 ± 2.5 (p < 0.001). WOMAC scores decreased from 48.0 ± 17.2 to 23.6 ± 19.7 (p < 0.001). Failure was seen in 21 patients.

CONCLUSION

Compared to demographic data in the literature, valgus high tibial osteotomy seems to reduce the progression of OA, reduces pain and improves knee function in patients with medial compartment OA and a varus alignment.

LEVEL OF EVIDENCE

III.

Total knee arthroplasty after opening- versus closing-wedge high tibial osteotomy. A 135-case series with minimum 5-year follow-up

INTRODUCTION

High tibial osteotomy (HTO) is effective in treating isolated medial osteoarthritis of the knee, but subsequent deterioration is inevitable, and total knee arthroplasty (TKA) is then an option. The present study sought to compare TKA following medial opening-wedge HTO (OW-HTO) versus lateral closing-wedge HTO (CW-HTO) in terms of intraoperative data and clinical results. The study hypothesis was that there is no significant difference in clinical results or complications in TKA following OW-HTO or CW-HTO.

MATERIAL AND METHOD

A retrospective multicenter (9 centers) study was conducted for the French Society of Orthopedic Surgery and Traumatology (SoFCOT), including 135 TKAs following HTO (58 OW and 77 CW) at a minimum 5 years' follow-up. Mean interval between HTO and TKA was 134 months and was longer in case of CW-HTO (P<0.0001). Mean age at TKA was 65.4 years and older in case of CW-HTO (P=0.021). Tibial slope was greater in case of OW-HTO (P=0.024). Prior to TKA, 55.7% of patients could walk without canes, 98.4% found stairs difficult or impossible and only 19.1% could manage a walking distance greater than 1000m. Mean flexion was 110°; 54.2% of patients showed frontal knee stability and 87.8% sagittal stability; 60.1% had a mechanical axis in varus, without difference according to OW- or CW-HTO.

RESULTS

Hardware was almost systematically removed (in 98.5% of cases): in the same step for OW-HTO (P=0.018) or often in 2 steps for CW-HTO. The primary approach was generally re-used (54.2%), but less frequently in the CW-HTO group (P=0.0004). Lateral or medial ligament release was not associated in respectively 78.2% and 79.7% of cases. The TKA implant was usually without stem (87.2%) and was fitted using a conventional technique (74.4%). At a mean 87 months' follow-up, 78.5% of patients could walk without canes, stairs were still difficult or impossible for 67%, and 74.1% could now walk further than 1000m; mean flexion was 110.5°. Overall, 91.5% of patients showed frontal knee stability and 98.2% sagittal stability, without difference according to OW- or CW-HTO. There were 15 complications within 3 months, more often in the OW-HTO group (12.3%) although not significantly, and with no difference in severity. Late complications comprised loosening (5.5%) and infection (3.6%) and were more frequent in the CW-HTO group (12%) (P<0.05).

DISCUSSION

The study hypothesis was partially confirmed. The only technical differences concerned hardware removal, often performed in two steps in case of CW-HTO, and TKA approach, which differed from the primary approach in case of CW-HTO. Clinical results were comparable between OW- and CW-HTO, but late complications were more frequent in the CW-HTO group.

LEVEL OF EVIDENCE

III; comparative retrospective study.

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

INTRODUCTION

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

The epidemiology and trends in management of acute Achilles tendon ruptures in Ontario, Canada: a population-based study of 27 607 patients

AIMS

The aims of this study were to establish the incidence of acute Achilles tendon rupture (AATR) in a North American population, to select demographic subgroups and to examine trends in the management of this injury in the province of Ontario, Canada.

PATIENTS AND METHODS

Patients ≥ 18 years of age who presented with an AATR to an emergency department in Ontario, Canada between 1 January 2003 and 31 December 2013 were identified using administrative databases. The overall and annual incidence density rate (IDR) of AATR were calculated for all demographic subgroups. The annual rate of surgical repair was also calculated and compared between demographic subgroups.

RESULTS

A total of 27 607 patients (median age, 44 years; interquartile range 26 to 62; 66.5% male) sustained an AATR. The annual IDR increased from 18.0 to 29.3 per 100 000 person-years between 2003 and 2013. The mean IDR was highest among men between the ages of 40 and 49 years (46.0/100 000 person-years). The annual rate of surgical repair dropped from 20.1 in 2003 to 9.2 per 100 AATRs in 2013. There was a noticeable decline after 2009.

CONCLUSION

The incidence of AATR is increasing in Ontario, while the annual rate of surgical repair is decreasing. A sharp decline in the rate of surgical repair was noted after 2009. This coincided with the publication of several high-quality RCTs which showed similar outcomes for the 'functional' non-operative management and surgical repair. Cite this article: Bone Joint J 2017;99-B:78-86.