Total knee arthroplasty after high tibial osteotomy: a registry-based case-control study of 1,036 knees

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.

Alignment prior to total knee arthroplasty in high tibial osteotomy patients has no effect on subsequent functional outcomes

INTRODUCTION

The influence of prior high tibial osteotomy (HTO) on total knee arthroplasty (TKA) functional outcomes remains widely debated. Alignment of failed HTO can pose technical challenges with subsequent TKA. The primary aim of this study was to evaluate the influence of HTO alignment on the clinical outcomes of subsequent TKA. The secondary aim was to compare the time to TKA for each HTO alignment type.

METHODS

Patients who underwent TKA post lateral closing-wedge HTO for symptomatic medial compartment osteoarthritis between 2001 and 2014 were prospectively followed up for 2 years. A total of 159 patients were assigned to three groups based on their pre-TKA femora tibia angles using long lower limb radiographs: varus alignment (VrA) ≤ 3^o valgus, neutral alignment (NA) 3-9^o valgus alignment, valgus alignment (VlA) ≥ 9^o valgus. Functional outcomes were quantified using Knee Society Function Score and Knee Scores (KSFS and KSKS respectively), modified Oxford Knee Score (OKS), Short Form 36 Physical Component Score (SF-36 PCS), and SF-36 Mental Component Score (SF-36 MCS). Pre-operative and post-operative knee range of motion were also measured.

RESULTS

Mean pre-TKA KSKS in VrA patients (35 ± 18) was significantly lower than both NA (51 ± 19) and VlA (40 ± 21) patients (p < .05). Otherwise, there was no significant difference in functional outcome scores (KSFS, KSKS, OKS, SF-36 PCS and SF-36 MCS) or range of motion at 6 months and 2 years post-TKA. The mean duration from HTO to TKA was 12 ± 7 years with no significant differences between VrA, NA, and VlA HTO to TKA (13 ± 7 years, 13 ± 6 years and12 ± 8 years respectively, p > .05).

CONCLUSION

HTO alignment did not influence time to subsequent TKA. HTO alignment did not influence early outcomes as well as radiological outcomes of subsequent TKA.

LEVEL OF EVIDENCE

III.

Clinical Outcomes of Revision Total Knee Arthroplasty after High Tibial Osteotomy and Unicompartmental Knee Arthroplasty: A Systematic Review and Meta-Analysis

As more high tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA) are performed, orthopaedic surgeons realize that more HTO and UKA failures will require revision to total knee arthroplasty (TKA) in the future. To systematically evaluate the clinical outcomes of TKA after HTO and TKA after UKA, the Embase, PubMed, Ovid, Web of Science, and Cochrane Library databases were searched for studies investigating revision TKA after HTO and UKA published up to June 2021. RevMan version 5.3 was used to perform the meta‐analysis. The revision TKA after HTO and revision TKA after UKA groups were compared in terms of operative time, range of motion (ROM), knee score, postoperative complications, postoperative infection, revision, and revision implants used. Nine studies were ultimately included in the meta‐analysis. Results revealed that the knee score for the revision TKA after HTO group was better than that of the revision TKA after UKA group (MD 4.50 [95% CI 0.80–8.20]; p = 0.02). The revision TKA after HTO group had a lower revision rate (OR 0.65 [95% CI 0.55–0.78]; p < 0.00001) and fewer revision implants used (OR 0.11 [95% CI 0.05–0.23]; p < 0.00001). There were no statistical differences in operation time (MD ‐2.00 [95% CI −11.22 to 7.21]; p = 0.67), ROM (MD ‐0.04 [95% CI ‐3.69–3.61]; p = 0.98), postoperative complications (OR 1.41 [95% CI 0.77–2.60]; p = 0.27), or postoperative infections (OR 0.89 [95% CI 0.61–1.29]; p = 0.53). To conclude, the revision rate of revision TKA after UKA was greater, and more revision implants were required. It is important for orthopaedic surgeons to preserve bone during primary UKA.

Tibial metaphyseal sleeves in primary total knee arthroplasty following high tibial osteotomy and tibial plateau fracture; preliminary mid-term survival and outcome

BACKGROUND

Previous high tibial osteotomy (HTO), and tibial plateau fractures (TPF) may cause problems in subsequent total knee arthroplasty (TKA) due to altered metaphyseal bone structure. Higher rates of loosening of the tibial component have been described. In post-HTO and TPF cases, a more durable fixation could be achieved by tibial sleeves. This study investigates the preliminary short-to-midterm clinical and radiographic results in a cohort of these cases.

METHODS

A cohort of 28 patients was selected, 11 following HTO, and 17 following TPF. Standard clinical and radiologic follow-up was performed at 6 weeks, and one and two years. Revision with removal of primary prosthesis for any reason was the primary outcome. Patient reported pre- and postoperative pain, satisfaction and general health scores were collected at one and two years. Postoperative radiographs were analyzed for radiolucent lines.

RESULTS

There were no cases of aseptic loosening. Survival for all reasons was 96.4% (CI 77.2%-99.5%). One progressive radiolucent line was seen. Numerical rating scale (NRS) for pain with and without weightbearing at 2-year follow-up improved from 8 to 3 and from 5 to 2 points respectively. Overall general health scores improved with a median of 70 at ≥ 2 years, compared to 63 pre-operatively.

CONCLUSION

With no revision for aseptic loosening the use of tibial sleeves in primary TKA seems a safe and reliable method for fixation of the tibial component in metaphyseal bone with altered bone structure at short and mid-term follow-up.

LEVEL OF EVIDENCE

Level IV, cohort study.

Prior high tibial osteotomy is not a contraindication for medial unicompartmental knee arthroplasty

PURPOSE

To report on the outcome and complications of minimal invasive medial unicondylar knee arthroplasty (UKA) after failed prior high tibial osteotomy (HTO) as treatment for medial osteoarthritis in the knee. The hypothesis was that good results can be achieved, if no excessive postoperative valgus alignment and abnormal proximal tibial geometry is present.

METHODS

All medial UKAs after failed prior HTO (n = 30), performed between 2010 and 2018 were retrospectively reviewed. The patients were followed for revision surgery and survival of the UKA (defined as revision to TKA). Clinical examination using the Knee Society Score (KSS), Oxford Knee Score (OKS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), as well as radiological examination was performed. Radiographs were studied and the influence of the demographic factors and the radiographic measurements on the survival and the clinical outcome was analysed.

RESULTS

After a follow-up of 4.3 ± 2.6 years (2.1-9.9) 27 UKAs were available. The survival rate was 93.0%. Two UKAs were revised to TKA (excessive valgus alignment and tibial loosening with femoropatellar degeneration). Two further patients had revision surgery (hematoma and lateral meniscus tear). Follow-up clinical and radiological examination was performed in 21 cases: KSS 82.9 ± 10.1 (54.0-100.0), KSS (function) 93.3 ± 9.7 (70.0-100.0); OKS 42.7 ± 6.0 (25.0-48.0); WOMAC 7.9 ± 15.6 (0.0-67.1). No significant influence of demographic factors or radiological measurements on the clinical outcome was present.

CONCLUSION

Prior HTO is not a contraindication for medial UKA, because good-to-excellent results can be achieved in selected patients with medial osteoarthritis and previous HTO, treated with medial UKA, in a midterm follow-up. Excessive mechanical valgus axis should be avoided; therefore, patient selection and accurate evaluation of medial laxity, preoperative mechanical axis, joint line convergence and proximal tibial geometry are important.

LEVEL OF EVIDENCE

III.

Conversion Total Knee Arthroplasty

»

Conversion total knee arthroplasty (TKA) represents a heterogeneous group of procedures and most commonly includes TKA performed after ligamentous reconstruction, periarticular open reduction and internal fixation (ORIF), high tibial osteotomy (HTO), and unicompartmental knee arthroplasty (UKA).

»

Relative to patients undergoing primary TKA, patients undergoing conversion TKA often have longer operative times and higher surgical complexity, which may translate into higher postoperative complication rates.

»

There is mixed evidence on implant survivorship and patient-reported outcome measures when comparing conversion TKA and primary TKA, with some studies noting no differences between the procedures and others finding decreased survivorship and outcome scores for conversion TKA.

»

By gaining an improved understanding of the unique challenges facing patients undergoing conversion TKA, clinicians may better set patient expectations, make intraoperative adjustments, and guide postoperative care.

[Are the results of total knee arthroplasty after high tibial osteotomy worse?]

Hintergrund

Bei einem Teil der Patienten nach Tibiakopfumstellungsosteotomie (HTO) wird die Implantation einer Knietotalendoprothese (Knie-TEP) notwendig. Durch die HTO kann die Anatomie ungünstig verändert und die Knie-TEP-Operation erschwert sein. Ziel dieser Studie war es zu untersuchen, ob Patienten nach HTO gegenüber denjenigen mit primärer Gonarthrose in gleichem Maße von einer Knie-TEP profitieren.

Material und Methoden

Im lokalen Register konnten insgesamt 44 Patienten nach HTO und 1703 Patienten mit primärer Gonarthrose identifiziert werden. Zur Reduktion von Confoundern erfolgte eine 1:1 „propensity score matched-pair“-Analyse (Alter, Geschlecht, BMI, Komorbiditäten) bei Patienten mit einem 5‑Jahres-Follow-up. Es resultierten 35 gematchte Paare, welche hinsichtlich Kniefunktion, Schmerzniveau, Zufriedenheit mit dem Operationsergebnis sowie perioperativen Daten (Schnitt-Naht-Zeit, Implantattyp, Komplikationen) und Revisionen verglichen wurden.

Ergebnisse

Patienten mit vorangegangener HTO hatten prä- und 5 Jahre postoperativ eine vergleichbare Kniefunktion, jedoch ein signifikant höheres prä- und postoperatives Schmerzniveau. Trotz des höheren Schmerzniveaus zeigte sich eine vergleichbare Zufriedenheit mit dem Operationsergebnis. Die Schnitt-Naht-Zeit für die Knie-TEP nach HTO war signifikant länger und es wurden signifikant häufiger modulare Endoprothesen mit Stielverankerung implantiert. Hinsichtlich postoperativer Komplikationen innerhalb der ersten 3 Monate nach Operation unterschieden sich beide Kohorten nicht signifikant. Die Revisionsrate innerhalb von 5 Jahren war bei Patienten nach HTO nicht erhöht.

Schlussfolgerung

Fünf Jahre nach der Knie-TEP zeigten Patienten mit vorangegangener HTO eine vergleichbare Kniefunktion wie Patienten mit primärer Gonarthrose. Jedoch war bei Patienten nach HTO ein höheres Schmerzniveau zu verzeichnen. Der Operationsaufwand der Knie-TEP nach HTO war deutlich höher.

High Midterm Survival Rate of Uncemented Total Knee Arthroplasty After High Tibial Osteotomy: A Case-Control Study

BACKGROUND

Total knee arthroplasty (TKA) following high tibial osteotomy (HTO) is technically more demanding than TKA in a native knee. Studies have reported increased intraoperative and postoperative complication of TKA with previous HTO. The aim of this study is to compare the survival and complication rates and functional outcomes of uncemented TKA with previous HTO to primary TKA at our institution over a decade.

METHODS

This case-control study included 41 uncemented TKA after HTO between 2002 and 2012. For each case, 2 control patients were matched based on age and gender without previous HTO. The 2 groups were comparable for body mass index, as well as preoperative functional scores.

RESULTS

The mean follow-up was 7.8 ± 2.4 (range, 5-13.6) years. At last follow-up, there was no significant difference in functional outcomes or radiological imaging, particularly the rate of radiological loosening. There was no significant difference in complications (9; 22%) in the group of TKA after HTO vs the control group (14; 17%). One revision was performed in the group of TKA after HTO for septic loosening, and no revisions in the control group. The survival rate at a mean follow-up of 8 years was 97.6% in the group TKA after HTO vs 100% in the control group.

CONCLUSION

Uncemented TKAs following HTO have no significant difference in functional and radiological outcomes and survivorship compared to uncemented primary TKA at midterm follow-up.

Reduced survival of total knee arthroplasty after previous unicompartmental knee arthroplasty compared with previous high tibial osteotomy: a propensity-score weighted mid-term cohort study based on 2,133 observations from the Danish Knee Arthroplasty Registry

Background and purpose - Both medial unicompartmental knee arthroplasties (UKA) and high tibial osteotomies (HTO) are reliable treatments for isolated medial knee osteoarthritis. However, both may with time need conversion to a total knee arthroplasty (TKA). We conducted the largest nationwide registry comparison of the survival of TKA following UKA with TKA following HTO.Patients and methods - From the Danish Knee Arthroplasty Registry, aseptic conversions to TKA from UKA and TKA converted from HTO within the period of 1997-2018 were retrieved. The Kaplan-Meier method and the Cox proportional hazards regression were used to estimate the survival and hazard ratio (HR) for revision, considering confounding by indication utilizing propensity-score based inverse probability of treatment weighting (PS-IPTW).Results - PS-IPTW yielded a well-balanced pseudo-cohort (standard mean difference (SMD) < 0.1 for all covariates, except implant supplementation) of 963.8 TKAs following UKA and 1139.1 TKAs following HTO. The survival of TKA following UKA was significantly less than that of TKA following HTO with a 5-year estimated survival of 0.88 (95% confidence interval (CI) 0.85-0.90) and 0.94 (CI 0.93-0.96), respectively. The differences in survival corresponded to an implant-supplementation adjusted HR of 2.7 (CI 2.4-3.1) for TKA following UKA compared with TKA following HTO.Interpretation - Previous UKA more than doubled the revision risk of a subsequent TKA compared with previous HTO. This potential risk should be considered in the shared treatment decision of patients who are candidates for both UKA and HTO.

Higher risk of revision in total knee arthroplasty after high tibial osteotomy: a systematic review and updated meta-analysis

Background

High tibial osteotomy is commonly performed in young patients with high activity demand. Several studies have reported outcome of HTO. The reported 10-year survival ranged from 79 to 97.6%. The reported 15-year survival ranged from 56 to 65.5%, resulting in the need for conversion to TKA. Primary TKA now provides satisfactory long-term outcome in terms of function and survival. Researches have been conducted to compare clinical outcome between primary TKA and TKA after HTO to see if TKA should be the prior treatment rather than HTO in some cases. But the results were inconsistent. This study aims to compare the risk of revision and other parameters between total knee arthroplasty after high tibial osteotomy and primary total knee arthroplasty.

Methods

Searches and screens of the relevant literature were conducted, after which data were extracted and pooled analysis was performed to compare the clinical outcomes between the two groups.

Results

A total of 14 studies with 144,692 cases were included. Pooled analysis showed significantly more revisions and complications, and more tibial component loosening and impingement in postoperative X-ray in the HTO-TKA group. Surgical complexity during conversion to total knee arthroplasty was summarised and listed in table.

Conclusion

High tibial osteotomy offers satisfactory pain relief and functional outcome in selected patients with high activity demand. However, the need for subsequent TKA should be noted, which might be a technically challenging procedure with significantly higher risk of revision comparing to primary TKA.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Survival of total knee arthroplasty after high tibial osteotomy versus primary total knee arthroplasty: A meta-analysis

BACKGROUND

Theoretical considerations suggest that total knee arthroplasty (TKA) is technically more challenging after high tibial osteotomy (HTO), resulting in inferior results compared to primary TKA. However, several studies on this issue have shown contradictory results. The purpose of this meta-analysis to compare survivorship and clinical outcomes between TKA with and without previous HTO.

METHODS

We reviewed studies that evaluated pain and function scores, range of motion (ROM), operation time, Insall-Salvati (IS) ratio, complications, and survival rates in patients treated with TKA with previous HTO or with primary TKA with short- to midterm (<10 years) or long-term (>10 years) follow-up.

RESULTS

Fifteen studies were included in the meta-analysis. There were no significant differences between TKA with and without previous HTO in pain score (95% CI: -0.27 to 0.29; P = .94), function score (95% CI: -0.08 to 0.24; P = .32), operation time (95% CI: -5.43 to 26.85; P = .19), IS ratio (95% CI: -0.03 to 0.08; P = .40), complication rates (TKA with previous HTO, 62/1717; primary TKA, 610/31386; OR 1.31, 95% CI: 0.97-1.77; P = .08), and short- to midterm survival rates (TKA with previous HTO, 1860/2009; primary TKA, 37848/38765; OR 0.55, 95% CI: 0.28-1.10; P = .09). Conversely, ROM (95% CI: -7.40 to -1.26; P = .006) and long-term survival rates (TKA with previous HTO, 1426/1523; primary TKA, 29810/31201; OR 0.71, 95% CI: 0.57-0.89; P = .003) were significantly different between the two groups. In addition, both groups had substantial proportions of knees exhibiting short- to midterm survivorship (92.6% by TKA with previous HTO and 97.6% by primary TKA) and long-term survivorship (93.6% by TKA with previous HTO and 95.5% by primary TKA).

CONCLUSIONS

This meta-analysis suggests that a previous HTO affected ROM or survival of TKA in the long-term even though both groups have equivalent clinical outcomes and complications. Thus, orthopedic surgeons should offer useful information regarding the advantages and disadvantages of both procedures to patients, and should provide advice on the generally higher risk of revision after TKA with previous HTO at long-term follow-up when counseling patients.

Total Knee Arthroplasty After High Tibial Osteotomy Results in Excellent Long-Term Survivorship and Clinical Outcomes

BACKGROUND

Some prior reports of total knee arthroplasty after high tibial osteotomy have shown high rates of aseptic loosening. As such, the goal of this study was to analyze the outcomes of contemporary total knee arthroplasty after high tibial osteotomy, with particular emphasis on survivorship free from aseptic loosening, any revision, and any reoperation; complications; radiographic results; and clinical outcomes.

METHODS

We retrospectively reviewed 207 patients who underwent 231 total knee arthroplasties using cemented prostheses after high tibial osteotomy from 2000 to 2012 through our total joint registry: 87% were after a closing-wedge osteotomy and 13% were after an opening-wedge osteotomy. The mean follow-up from total knee arthroplasty was 8 years. At the time of the total knee arthroplasty, the mean age was 64 years and the mean body mass index was 31 kg/m. The majority of total knee arthroplasties had a posterior-stabilized design (93%), and 4% had a varus-valgus constraint design. Tibial stems were utilized in 8% of cases. Bivariate and multivariate Cox regression analyses were utilized to analyze risk factors for poorer survival.

RESULTS

At 10 years, survivorship free from aseptic loosening was 97%, survivorship free from any revision was 90%, and survivorship free from any reoperation was 85%. Fifteen patients (15 total knee arthroplasties [6%]) underwent aseptic revision, most commonly for instability (3%), aseptic loosening (2%), and periprosthetic fracture (1%). On bivariate analysis, patient age of <60 years was a significant risk factor for poorer revision-free survival (hazard ratio, 2.9; p = 0.02); on multivariate analysis, younger age was the only significant risk factor for revision (p = 0.04). There were 14 complications (6%), the most common being a manipulation under anesthesia in 9 cases (4%). No unrevised total knee arthroplasties had definitive radiographic evidence of loosening. Knee Society scores improved from a mean preoperative score of 59 points to a mean postoperative score of 93 points (p < 0.001).

CONCLUSIONS

Contemporary total knee arthroplasty with a cemented prosthesis after high tibial osteotomy demonstrated excellent long-term durability, with 10-year survivorship free from aseptic loosening of 97%. There was reliable improvement in clinical outcomes, but perfect knee balance was sometimes challenging, as reflected by a 4% prevalence of manipulation under anesthesia and a 3% prevalence of revision for instability.

LEVEL OF EVIDENCE

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

Primary cementless total knee arthroplasty with or without stem extension: a matched comparative study of ninety eight standard stems versus ninety eight long stems after more than ten years of follow-up

INTRODUCTION

Using a cementless fixation for total knee arthroplasty (TKA) is controversial. We hypothesized that cementless tibial base plate with a monoblock long stem (MLS) would provide secure tibial alignment and stable fixation when bone conditions were considered as poor for a cementless fixation. The purpose of this study was to compare the mean eight year survivorship of cementless standard keels (SK) vs cementless MLS.

MATERIAL METHODS

We report a matched series of 98 cases of SK and 98 cases of MLS in patients with poor bone conditions. The two cohorts were statistically compared. Revision for tibial loosening was used as the endpoint in the survivorship analysis.

RESULTS

We recorded two cases of tibial loosening and three cases of bipolar loosening in the SK group (0% MLS vs 5% SK). No tibial loosening occurred in the MLS group (statistically significant). No tibial periprosthetic or intra-operative fractures occurred in either group. The survivorship at eight years of follow-up was 95.6% in the SS cohort vs 100% in the MLS cohort using revision for tibial loosening as the endpoint.

DISCUSSION

This study was not randomized. Its strength was that it took into account the comparative midterm outcomes of a matched cohort of patients implanted with two types of cementless components in the same bone conditions. We did not record any tibial loosening in the MLS group. Using long stems has been criticized but we did not observe any adverse reactions and no intra-operative tibial fracture occurred.

CONCLUSION

MLS improves the alignment and fixation of cementless TKA. This is a safe solution when bone conditions are poor or modified by previous surgery.

Prior High Tibial Osteotomy Does Not Affect the Survival of Total Knee Arthroplasties: Results From the Danish Knee Arthroplasty Registry

BACKGROUND

High tibial osteotomy (HTO) is a joint preserving treatment of unicompartmental osteoarthritis in the knee. In cases with insufficient or deteriorating clinical results patients may undergo a total knee arthroplasty (TKA). The influence of prior HTO on TKA survival is debated.

METHODS

We conducted a population-based registry study comparing 1044 primary TKAs in patients with prior HTO to 63,763 de novo TKAs inserted from 1997 to 2015. Implant survival was estimated by Kaplan-Meier analysis with revision of any kind as endpoint. Patient and surgery characteristics, including choice of implant design, were compared and their influence on TKA survival was estimated by Cox regression. Finally, indications of revision were compared between the groups.

RESULTS

TKA following HTO had an inferior survival with a 10-year estimated survival of 91% compared to 94% for de novo TKA, corresponding to a crude hazard ratio (HR) of 1.73 (P < .001). However, after adjustment for differences in gender and age this risk diminished (HR 1.19, P = .09). The choice of implant constraint was similar between the groups and in both groups posterior stabilized TKA was associated with inferior survival with an adjusted HR of 1.46 (P = .03) in post-HTO TKA when compared to cruciate-retaining TKA.

CONCLUSION

TKA following HTO had a crude inferior survival when compared to TKA without prior surgery of any kind. The inferior survival was explainable by patient characteristics, defined by male gender and lower age, rather than the prior HTO. However, when the prior HTO resulted in the use of posterior stabilized TKA the survival decreased.

Ten-Year Results of Medial Open-Wedge High Tibial Osteotomy and Chondral Resurfacing in Severe Medial Osteoarthritis and Varus Malalignment

BACKGROUND

High tibial osteotomy (HTO) is a widely used treatment option for medial osteoarthritis and varus malalignment, especially in young patients with early osteoarthritis. Limited outcome data are available for this procedure in severe osteoarthritis, and no long-term data are available using newer implants.

PURPOSE

To determine survivorship and functional results of medial open-wedge HTO combined with a chondral resurfacing (CR) procedure (abrasion plus microfracture) in severe medial osteoarthritis (Kellgren-Lawrence grade 3 and 4) and varus malalignment. Furthermore, factors that potentially influence the outcome were analyzed.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

From September 2005 to December 2008, all cases of HTO (fixation with an angular-stable internal fixator) combined with CR were prospectively surveyed with regard to survival (Kaplan-Meier-method, not requiring arthroplasty) and functional outcome (subjective International Knee Documentation Committee [IKDC] score). Cartilage regeneration at the time of hardware removal, tibial bone varus angle (TBVA), pre- and postoperative mechanical medial proximal tibial angle (MPTA), and postoperative alignment were analyzed with regard to the result.

RESULTS

Seventy-nine knees were included (73 patients; mean age 50.9 ± 7.6 years). The follow-up rate was 90% at 10.0 ± 1.2 years (range, 8.3-12.1 years). Pre- and postoperative mechanical tibiofemoral axis were 9.6° ± 3.0° of varus and 0.6° ± 2.7° of valgus, respectively. Survival rate was 81.7% (95% CI, 72.5%-90.9%) at 10 years. Subjective IKDC score significantly improved from 44 ± 11 preoperatively to 70 ± 13 at one, 66 ± 15 at three, 66 ± 15 at five, and 65 ± 17 at ten years ( P < .001 at any point of follow-up). Poor cartilage regeneration and low preoperative IKDC score (<40) were associated with decreased survival. High preoperative TBVA was associated with better and an overcorrected MPTA (>95°) with inferior functional outcome at final follow-up, respectively.

CONCLUSION

Even in cases of severe medial osteoarthritis and varus malalignment, HTO in combination with a CR procedure is a good to excellent treatment option. The role of the CR procedure remains unclear. Although good results are obtained with overcorrected MPTA, long-term functional outcome is inferior.

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.

Comparison of mid-term results between conversion total knee arthroplasties following closed wedge high tibial osteotomy and primary total knee arthroplasties: A matched pair study including patellar symptom and position

BACKGROUND

The purpose of this study was to compare mid-term clinical and radiographic results of conversion total knee arthroplasties (TKA) following a closed-wedge high tibial osteotomy (HTO) and primary TKAs.

METHODS

A total of 32 conversion TKAs (29 patients) were compared with a matched control group of patients who had undergone primary TKA. The clinical results were evaluated using the Knee Society Knee and Function score, the Western Ontario and McMaster Universities score, patella score, and range of motion (ROM). The radiographic results were evaluated using femorotibial angle, mechanical axis (MA), the method employed by the American Knee Society, joint line height (JLH), the amount of tibial bone resection, and the Insall-Salvati ratio. The clinical and radiographic results of conversion TKAs were compared with primary TKAs. The thickness of the polyethylene insert was also compared.

RESULTS

No significant differences were observed in the clinical scores or ROM between two groups. No significant differences were detected in femorotibial angle, MA, and position of the components between two groups. The amount of tibial bone resection and pre-operative JLH both were significantly lower in the conversion group than those in the control group, although postoperative JLH and pre and postoperative Insall-Salvati ratio did not differ between two groups. No significant difference in the thickness of the polyethylene insert was identified between two groups.

CONCLUSIONS

The previous closed-wedge HTO itself had no detrimental effect on the mid-term outcome of the subsequent TKA, including patellar symptom and position. No significant differences in the postoperative joint line and patella height were detected between the conversion and primary TKA groups.

Clinical Outcome of Total Knee Arthroplasty After Prior Microfracture: A Matched Cohort Study

Microfracture (MFX) is a common operation for articular cartilage lesions. Data for patients who underwent total knee arthroplasty (TKA) after previous MFX are limited. The purpose of this study was to determine the outcomes, complications, and factors that influence outcomes in patients with previous MFX compared with those without previous MFX. Between 2005 and 2014, twenty-one TKAs were performed at a single tertiary care academic institution in patients with prior history of MFX surgery. These patients were retrospectively reviewed and matched 2:1 to patients who did not undergo previous MFX (n=42). Knee Society Score (KSS) (Subjective [KSS-S] and Function [KSS-F]) and complications were documented. Mean KSS-S in the MFX group increased significantly less (52.9 to 77.6) (P<.01) compared with the control group (51.3 to 83.8) (P<.01). The MFX group also demonstrated significantly less improvement in KSS-F from 63.0 to 88.9 (P=.02), whereas the control group demonstrated improvement from 52.4 to 87.1 (P=.02). At 5 years, the failure rate was 4.8% in the MFX group and 2.4% in the control group. Multivariate analysis found that older age at TKA resulted in smaller improvement in KSS-S. Paired relationships between increased age and decreased preoperative range of motion and women with an increased body mass index negatively affected KSS-S. Survivorship was similar between groups, but patients with MFX had slightly less clinical improvement compared with a matched control group. This study suggests that underlying patient factors may limit clinical improvement compared with primary TKA. [Orthopedics. 2017; 40(3):e473-e478.].

Preoperative varus laxity correlates with overcorrection in medial opening wedge high tibial osteotomy

PURPOSE

Medial opening wedge high tibial osteotomy (HTO) is a realignment of the lower limb. Despite accurate preoperative planning and careful surgical techniques, many HTOs result in alignment correction errors. These alignment correction errors may be due to soft tissue laxity around the knee such as varus or valgus laxity. The purpose of this study was to examine the relationship of varus and valgus laxity of the knee and alignment correction errors, and to have a formula to predict the subsequent degree of these correction errors.

MATERIALS AND METHODS

Fifty knees from 41 patients undergoing opening wedge HTO for knee osteoarthritis were involved. Standing full-length anteroposterior radiographs of the lower limb and the tibia, and varus and valgus stress radiographs of the knee were used to evaluate alignment and joint laxity. Parameters were global correction (the change in the hip-knee-ankle angle), bony correction (the change in the medial proximal tibial angle), and soft tissue correction (global correction - bony correction).

RESULTS

The average of global correction, bony correction, and soft tissue correction were 12.8° ± 4.3°, 9.4° ± 3.2°, and 3.4° ± 2.5°, respectively. Preoperative varus laxity was moderately correlated with soft tissue correction (R = 0.58), and in which the slope of the line in the scatter plot represented 0.59, implying that soft tissue correction increases by 0.59° for every 1° of preoperative varus laxity.

CONCLUSIONS

Preoperative varus laxity is correlated with soft tissue correction, suggesting that more accurate alignment correction could be achieved by surgical planning taking into account preoperative varus laxity as a factor of soft tissue correction.

High tibial osteotomy in varus knees: indications and limits

Opening wedge high tibial osteotomy (OWHTO) is a surgical procedure that aims to correct the weight-bearing axis of the knee, moving the loads laterally from the medial compartment. Conventional indications for OWHTO are medial compartment osteoarthritis and varus malalignment of the knee; recently OWHTO has been used successfully in the treatment of double and triple varus. OWHTO, in contrast to closing wedge high tibial osteotomy, does not require fibular osteotomy or peroneal nerve dissection, or lead to disruption of the proximal tibiofibular joint and bone stock loss. For these reasons, interest in this procedure has grown in recent years. The aim of this study is to review the literature on OWHTO, considering indications and prognostic factors (body mass index, grade of osteoarthritis, instability, range of movement and age), outcomes at mid-term follow-up, and limits of the procedure (slope modifications, patellar height changes and difficulties in conversion to a total knee arthroplasty).

Conversion Total Knee Arthroplasty after Failed High Tibial Osteotomy

Clinical results of high tibial osteotomy (HTO) deteriorate over time despite the initial satisfactory results. Several knees may require a conversion to total knee arthroplasty (TKA) because of failure such as the progression of degenerative osteoarthritis and the loss of the correction angle. It is important to know the long-term survival rate and common reason of failure in HTO to inform patients of postoperative expectations before surgery and to prevent surgical errors during surgery. In addition, it has been reported that clinical and radiological results, revision rate, and complication rate were poorer than those in patients without a previous HTO. There are few review articles that describe why conversion TKA after HTO is surgically difficult and the results are poor. Surgeons have to avoid the various complications and surgical errors in this specific situation. We would like to present the considering factors and technical difficulties during conversion TKA after HTO with a review of the literature. We could conclude through the review that the correction of deformity, lower amount of tibial bone resection, and sufficient polyethylene insert thickness, restoration of the joint line height, and adequate ligament balancing can be helpful in overcoming the technical challenges encountered during TKA following HTO.

Cruciate retaining versus posterior stabilized total knee arthroplasty after previous high tibial osteotomy

PURPOSE

This study aimed to investigate the clinical outcome of total knee arthroplasty (TKA) after previous high tibial osteotomy (HTO) using cruciate retaining (CR) versus posterior stabilized (PS) prostheses.

METHODS

Between 2001 and 2010, 133 patients who underwent TKA after previous HTO were included in this study and prospectively followed up for two years. Two independent assessors recorded the range of motion of the operated knee, anterior-posterior (AP) laxity, medial-lateral (ML) laxity, Oxford Knee Score (OKS), Knee Society Function Score (KSFS) and Knee Society Knee Score (KSKS).

RESULTS

Thirty-three patients received CR prostheses, while 100 patients received PS prostheses. The median (inter-quartile range) knee flexion at 6 months and 2 years post-TKA was 101° (90, 116) and 110° (90, 118), respectively for the CR group, compared to 115° (100, 121) and 118° (108, 125) for the PS group (p = 0.010 and p = 0.009, respectively). AP and ML laxities were comparable in both groups of patients. While both groups of patients showed improvement in OKS, KSFS and KSKS at 6 months and 2 years post-TKA, there was no significant difference in these clinical scores between the two groups at both time points of follow-up. None of the 133 patients required revision surgery.

CONCLUSIONS

Although PS prostheses offer better knee flexion in TKA after previous HTO, the knee stability, clinical scores and revision rate at 6 months and 2 years post-TKA are comparable between CR and PS prostheses. The authors conclude that CR is an alternative to PS prostheses in patients undergoing TKA after previous HTO.

LEVEL OF EVIDENCE

III.

The risk of revision in total knee arthroplasty is not affected by previous high tibial osteotomy

BACKGROUND AND PURPOSE

Previous studies have found different outcomes after revision of knee arthroplasties performed after high tibial osteotomy (HTO). We evaluated the risk of revision of total knee arthroplasty with or without previous HTO in a large registry material.

PATIENTS AND METHODS

31,077 primary TKAs were compared with 1,399 TKAs after HTO, using Kaplan-Meier 10-year survival percentages and adjusted Cox regression analysis.

RESULTS

The adjusted survival analyses showed similar survival in the 2 groups. The Kaplan-Meier 10-year survival was 93.8% in the primary TKA group and 92.6% in the TKA-post-HTO group. Adjusted RR was 0.97 (95% CI: 0.77-1.21; p = 0.8).

INTERPRETATION

In this registry-based study, previous high tibial osteotomy did not appear to compromise the results regarding risk of revision after total knee arthroplasty compared to primary knee arthroplasty.

The cost-effectiveness of surgical treatment of medial unicompartmental knee osteoarthritis in younger patients: a computer model-based evaluation

BACKGROUND

Surgical options for the management of medial compartment osteoarthritis of the varus knee include high tibial osteotomy, unicompartmental knee arthroplasty, and total knee arthroplasty. We sought to determine the cost-effectiveness of high tibial osteotomy and unicompartmental knee arthroplasty as alternatives to total knee arthroplasty for patients fifty to sixty years of age.

METHODS

We built a probabilistic state-transition computer model with health states defined by pain, postoperative complications, and subsequent surgical procedures. We estimated transition probabilities from published literature. Costs were determined from Medicare reimbursement schedules. Health outcomes were measured in quality-adjusted life-years (QALYs). We conducted analyses over patients' lifetimes from the societal perspective, with health and cost outcomes discounted by 3% annually. We used probabilistic sensitivity analyses to account for uncertainty in data inputs.

RESULTS

The estimated discounted QALYs were 14.62, 14.63, and 14.64 for high tibial osteotomy, unicompartmental knee arthroplasty, and total knee arthroplasty, respectively. Discounted total direct medical costs were $20,436 for high tibial osteotomy, $24,637 for unicompartmental knee arthroplasty, and $24,761 for total knee arthroplasty (in 2012 U.S. dollars). The incremental cost-effectiveness ratio (ICER) was $231,900 per QALY for total knee arthroplasty and $420,100 per QALY for unicompartmental knee arthroplasty. Probabilistic sensitivity analyses showed that, at a willingness-to-pay (WTP) threshold of $50,000 per QALY, high tibial osteotomy was cost-effective 57% of the time; total knee arthroplasty, 24%; and unicompartmental knee arthroplasty, 19%. At a WTP threshold of $100,000 per QALY, high tibial osteotomy was cost-effective 43% of time; total knee arthroplasty, 31%; and unicompartmental knee arthroplasty, 26%.

CONCLUSIONS

In fifty to sixty-year-old patients with medial unicompartmental knee osteoarthritis, high tibial osteotomy is an attractive option compared with unicompartmental knee arthroplasty and total knee arthroplasty. This finding supports greater utilization of high tibial osteotomy for these patients. The cost-effectiveness of high tibial osteotomy and of unicompartmental knee arthroplasty depend on rates of conversion to total knee arthroplasty and the clinical outcomes of the conversions.