The Effect of Supramalleolar Osteotomy without Marrow Stimulation for Medial Ankle Osteoarthritis: Second-Look Arthroscopic Evaluation of 29 Ankles

Surgical Correction of Large Talar Tilt in Varus Ankle Osteoarthritis: Lessons from Clinical Experience and a Review of the Literature

Numerous studies exist on medial opening wedge supramalleolar osteotomy (SMO), ever since its introduction by Takakura et al., as a joint-preserving surgical option for treating varus ankle osteoarthritis (OA). Although SMO can induce lateral translation of the talus-which is medially translated in varus ankle OA-it has only minimal effects on the correction of the varus tilt of the talus. Particularly, SMO alone does not effectively neutralize the talar position. The primary reason for this limitation is that varus tilting of the talus is not merely a two-dimensional deformity in the coronal plane, but rather a three-dimensional deformity involving internal rotation and anterior subluxation. Therefore, this study aimed to explore the key considerations for achieving effective correction of varus talar tilt in joint-preserving surgery for treating degenerative varus ankle OA with large talar tilting. Further, we have discussed the relevant studies and included the lessons learned from our clinical experience, categorizing the key surgical considerations into preoperative, intraoperative, and postoperative phases.

Critical factors in enhancing the correction efficacy for varus talar tilt in patients with varus ankle osteoarthritis: relative fibular shortening to the tibia and syndesmotic widening

INTRODUCTION

Relative fibular shortening compared to the tibia and syndesmotic widening are recognized contributors to the valgus tilt of the talus. This study aimed to assess: (1) the impact of fibular shortening relative to the tibia; and (2) the influence of syndesmotic widening, in correcting a large varus talar tilt (TT) associated with advanced ankle osteoarthritis through medial opening wedge valgization supramalleolar osteotomy (SMO).

MATERIALS AND METHODS

We retrospectively reviewed the clinico-radiographic findings of 41 patients with a preoperative TT of 8 degrees or more who underwent SMO for varus ankle osteoarthritis, with a minimum follow-up of more than two years. We compared several clinico-radiographic parameters between the three groups based on postoperative TT changes (decreased TT by 2 degrees or more, no TT changes [TT change between - 2 and 2 degrees], and increased TT by 2 degrees or more).

RESULTS

In total, 18, 16, and 7 patients were included in the groups with postoperative decreased TT, no TT changes, and postoperative increased TT, respectively. The postoperative talocrural angle was greater in the postoperative increased TT group than in the postoperative decreased TT group (P =.036). The postoperative tibiofibular clear space was greatest in the postoperative decreased TT group (P =.037), whereas the other two groups were not significantly different (P =.260). In the postoperative increased TT group, postoperative tibial plafond inclination was the lowest among the three groups (P =.048 and 0.023, respectively), indicating the greatest plafond valgus inclination to the ground. All postoperative clinical parameters were significantly lower in the postoperative increased TT group (P <.05).

CONCLUSION

When performing SMO for varus ankle osteoarthritis, TT correction might be associated with the relative length of the fibula to the tibia and the role of the syndesmosis, implying the need for fibular shortening/valgization and syndesmotic widening. Additionally, excessive correction during SMO that places the tibial plafond in a valgus position relative to the ground floor can paradoxically increase TT and exacerbate ankle osteoarthritis.

LEVEL OF EVIDENCE

Level III.

Prediction of prognosis in supramalleolar osteotomy with or without additional fibula osteotomy by approaching a biomechanical study: a finite element analysis

Supramalleolar osteotomy (SMO) is a representative procedure to restore a malalignment in the varus ankle deformity by shifting the concentrated pressure on the medial ankle joint to the lateral area. Additionally, fibula osteotomy (FO) is selectively selected and performed according to the surgeon's preference. However, it is controversial whether FO is effective in shifting the abnormal pressure from the medial to the lateral area on the ankle joint. Some cadaveric studies have been performed to prove this. However, it is difficult to consistently reconstruct amount of the varus ankle deformities angle in cadavers and to guarantee reliable contact pressure between the ankle joint. Thus, the aim of this study was predicted and quantitatively compared a peak pressure between single SMO and SMO with FO procedure by using a finite element analysis as a powerful biomechanical tool to those limitations of cadaveric study. This study reconstructed total 4 3D foot and ankle models including a normal and pre-op model and 2 post-op models. The pre-op model was modified by assigning 10° varus tilting corresponding to stage 3b in the classification of varus ankle osteoarthritis based on the validated normal model. Also, the post-op models were reconstructed by applying single SMO and SMO with FO, respectively. All of the models were assumed as one-leg standing position and to mimic smooth ankle joint motion. Peak contact pressure change was predicted at the medial ankle joint by using computational simulation. As a result, 2 post-op models showed a remarkably peak pressure reduction by up to 5.5 times on the medial tibiotalar joint. However, a comparison between single SMO and SMO with FO model showed no appreciable differences. In conclusion, this study predicted that single SMO may be as effective as SMO with FO in reducing peak contact pressure on the medial tibiotalar joint in varus ankle osteoarthritis.

Pressure change at ankle joint in supramalleolar osteotomy with or without fibular osteotomy according to different types of varus ankle

The need for additional fibular osteotomy (FO) when performing supramalleolar osteotomy (SMO) in the varus ankle arthritis (VAA) is controversial. Some cadaveric studies have been performed to prove this; however, it is difficult to implement deformities including talar tilting and translation in cadavers. In this study, we created a model of VAA with the tilting and translation using three-dimensional (3-D) finite element (FE) analysis and analyzed the results of SMO with or without FO depending on the types of VAA. The validated normal foot and ankle 3-D FE model was constructed including the ankle cartilages of the talar dome and tibia plafond. The VAA models were determined and reconstructed by following the classification of VAA, VAA with medial translation for stage 3a, VAA with varus tilting (7.5°) for stage 3b. The postoperative SMO models (SMO with and without FO) were reconstructed by corresponding to each VAA models. The FE analysis conditions were commonly applied. The boundary condition of ankle joint was defined as "sliding condition" and applied 0.002 friction coefficient to realize lubricative property. Loading condition was assumed as a two-leg standing position and half of the subject body weight (325 N) was loaded on center of ground to vertical direction. Contact pressure changes were predicted at the medial ankle cartilage. As a result, in VAA with medial translation, isolated SMO may provide sufficient pressure reduction at the medial ankle joint. However, in VAA with varus tilting, SMO combined with FO could appropriately relieve concentrated pressure at the medial ankle joint.

Comparison of supramalleolar and inframalleolar correction for Takakura stage IIIB ankle arthritis in a single patient

A man in his early 60s with bilateral Takakura stage IIIB varus ankle arthritis underwent calcaneal osteotomy on the right side and supramalleolar osteotomy (SMO) with fibular osteotomy on the left side. Both sides underwent identical procedures, including multiple drilling of the denuded talar dome and gutter, deltoid ligament release, anterior talofibular ligament (ATFL) reconstruction and posterior tibial tendon (PTT) lengthening. This aimed to minimise patient-related factors when assessing correction efficacy. Both procedures demonstrated a similar degree of improvement in talar tilt. Supramalleolar correction contributed more significantly to lateralising the talar centre, while greater improvement in preoperative hindfoot varus was achieved through inframalleolar correction.

Radiographic Evaluation of the Association between Foot Deformities and Ankle Medial Osteoarthritis

Background

Foot deformities can cause abnormal biomechanics of the ankle joint and the development of osteoarthritis. It was hypothesized that foot deformities would be related to medial ankle osteoarthritis, and this study investigated this relationship using radiographic measurements.

Methods

Seventy-six ankles of 76 patients (32 men and 44 women; mean age, 69.0 years) with medial ankle osteoarthritis were included. Eleven radiographic measurements evaluated ankle joint orientation (tibial plafond inclination [TPI], medial distal tibial angle [MDTA], and anterior distal tibial angle [ADTA]), ankle joint incongruency (tibiotalar tilt [TT]), foot deformities (lateral talo-first metatarsal angle [Lat talo-1MT], anteroposterior talo-first metatarsal angle [AP talo-1MT], and talonavicular coverage), talar body migration (medial talar center migration [MTCM] and anterior talar center migration [ATCM]), internal rotation (IR) of the talus, and mechanical tibiofemoral angle. All were statistically analyzed using Pearson's correlation coefficients and regression analyses.

Results

Ankle joint orientation to the ground (TPI, p = 0.002), increased foot arch (Lat talo-1MT, p < 0.001), and IR of the talus (p = 0.001) were significantly associated with ankle joint incongruency (TT) in linear regression analysis. Ankle joint incongruency (TT, p = 0.003), medial talar body migration (MTCM, p = 0.042), and increased foot arch (Lat talo-1MT, p = 0.022) were significantly associated with IR of the talus in the binary logistic regression analysis. MTCM was significantly correlated with TPI (r = 0.251, p = 0.029), TT (r = 0.269, p = 0.019), MDTA (r = 0.359, p = 0.001), ATCM (r = -0.522, p < 0.001), and AP talo-1MT (r = 0.296, p = 0.015). ATCM was significantly correlated with TPI (r = -0.253, p = 0.027), ADTA (r = 0.349, p = 0.002), and Lat talo-1MT (r = -0.344, p = 0.002).

Conclusions

Ankle joint orientation, foot deformities, and talar rotation were associated with ankle joint incongruency in medial ankle osteoarthritis when evaluated radiographically. These findings need to be considered during surgical treatment for medial ankle osteoarthritis. However, the biomechanical significance of these radiographic measurements requires further investigation.

Changes in clinical outcomes and alignment of the ipsilateral knee and ankle after supramalleolar osteotomy in patients with varus osteoarthritis of the ankle: a short-term follow-up study

PURPOSE

The purpose of this study was to investigate the changes in clinical outcomes and alignment of the ipsilateral knee and ankle in patients with varus ankle osteoarthritis after supramalleolar osteotomy (SMO).

METHODS

We retrospectively reviewed 23 patients (24 ankles) with Takakura II, IIIa and IIIb ankle osteoarthritis treated with SMO between May 2017 and March 2022. The radiologic parameters of ankles contained medial distal tibial angle (TAS), tibiotalar angle (TT), tibial lateral surface (TLS), tibial plafond inclination (TPI) and talar inclination (TI). The radiologic parameters of knees contained medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), the knee joint line orientation relative to ground (G-KJLO) and WBL. Hip-knee-ankle angle (HKA) was also collected. The Takakura system was used for evaluating the ankle osteoarthritis and the Kellgren-Lawrence (KL) system was used for evaluating the knee osteoarthritis. Clinical evaluation of the ankle joints contained American Orthopedic Foot and Ankle Society (AOFAS), range of motion (ROM) and visual analogue scale (VAS). Clinical evaluation of the knee joints contained Japanese Orthopaedic Association Scores (JOA), ROM, VAS.

RESULTS

The mean follow-up times were 20.3 ± 7.3 months (range 12-38). According to the radiologic evaluation, the TAS increased from preoperative 84.7° ± 2.0° to 91.2° ± 1.8° at the last follow-up (P < 0.001). The TPI and TI decreased from 4.4° ± 4.2° and 11.0° ± 5.2° to 0.1° ± 4.7° and 4.1° ± 4.8° (P < 0.001 for both). The TT angel improved from 9.5° ± 4.1° to 4.9° ± 3.3° (P < 0.001). No significant differences were found regarding MPTA, JLCA, G-KJLO, knee WBL and HKA (P > 0.05 for all). The Takakura stage improved after SMO (P < 0.001) whilst the KL stage maintains the similar lever (P > 0.05). According to the clinical evaluation, the AOFAS significantly increased from 67.5 ± 10.6 to 88.5 ± 9.3 and the VAS of the ankle decreased from 4.7 ± 1.6 to 1.2 ± 1.1, whilst there were no changes on VAS and even the JOA and knee ROM after SMO (P > 0.05 for all).

CONCLUSIONS

SMO can alleviate the symptoms of varus ankle osteoarthritis and delay the time for ankle replacement or arthrodesis by redistributing the abnormal stress of the ankle and restoring the congruence of the tibiotalar joint. In addition, it did not induce the clinical symptoms of knee without compromising lower limb alignment or knee joint line orientation in the short term.

LEVEL OF EVIDENCE

Level IV case series.

Supramalleolar Osteotomies in Cavovarus Foot Deformity: Why Patient-Specific Instruments Make a Difference

Supramalleolar osteotomy enables correction of the ankle varus deformity and is associated with improvement of pain and function in the short term and long term. Despite these beneficial results, the amount of surgical correction is challenging to titrate and the procedure remains technically demanding. Most supramalleolar osteotomies are currently planned preoperatively on 2-dimensional weight-bearing radiographs and executed peroperatively using free-hand techniques. This article encompasses 3-dimensional planning and printing techniques based on weight-bearing computed tomography images and patient-specific instruments to correct ankle varus deformities.

The Unloading Effect of Supramalleolar Versus Sliding Calcaneal Osteotomy for Treatment of Osteochondral Lesions of the Medial Talus: A Biomechanical Study

Background

In patients with osteochondral lesion, defects of the medial talus, or failed cartilage surgery, a periarticular osteotomy can unload the medial compartment.

Purpose

To compare the effects of supramalleolar osteotomy (SMOT) versus sliding calcaneal osteotomy (SCO) for pressure redistribution and unloading of the medial ankle joint in normal, varus-aligned, and valgus-aligned distal tibiae.

Study Design

Controlled laboratory study.

Methods

Included were 8 cadaveric lower legs with verified neutral ankle alignment (lateral distal tibial angle [LDTA] = 0°) and hindfoot valgus within normal range (0°-10°). SMOT was performed to modify LDTA between 5° valgus, neutral, and 5° varus. In addition, a 10-mm lateral SCO was performed and tested in each position in random order. Axial loading (700 N) of the tibia was applied with the foot in neutral alignment in a customized testing frame. Pressure distribution in the ankle joint and subtalar joint, center of force, and contact area were recorded using high-resolution Tekscan pressure sensors.

Results

At neutral tibial alignment, SCO unloaded the medial joint by a mean of 10% ± 10% or 66 ± 51 N (P = .04) compared with 6% ± 12% or 55 ± 72 N with SMOT to 5° valgus (P = .12). The achieved deload was not significantly different (ns) between techniques. In ankles with 5° varus alignment at baseline, SMOT to correct LDTA to neutral insufficiently addressed pressure redistribution and increased medial load by 6% ± 9% or 34 ± 33 N (ns). LDTA correction to 5° valgus (10° SMOT) unloaded the medial joint by 0.4% ± 14% or 20 ± 75 N (ns) compared with 9% ± 11% or 36 ± 45 N with SCO (ns). SCO was significantly superior to 5° SMOT (P = .017) but not 10° SMOT. The subtalar joint was affected by both SCO and SMOT, where SCO unloaded but SMOT loaded the medial side.

Conclusion

SCO reliably unloaded the medial compartment of the ankle joint for a neutral tibial axis. Changes in the LDTA by SMOT did not positively affect load distribution, especially in varus alignment. The subtalar joint was affected by SCO and SMOT in opposite ways, which should be considered in the treatment algorithm.

Clinical Relevance

SCO may be considered a reliable option for beneficial load-shifting in ankles with neutral alignment or 5° varus malalignment.

Supramalleolar osteotomies for ankle arthritis: a systematic review

INTRODUCTION

We investigated the mid-term outcomes of supramalleolar osteotomies regarding "survivorship" [before ankle arthrodesis (AA) or total ankle replacement (TAR)], complication rate and adjuvant procedures required.

MATERIAL AND METHODS

PubMed, Cochrane and Trip Medical Database were searched from January 01, 2000. Studies reporting on SMOs for ankle arthritis, in minimum of 20 patients aged 17 or older, followed for a minimum of two years, were included. Quality assessment was performed with the Modified Coleman Methodology Score (MCMS). A subgroup analysis of varus/valgus ankles was performed.

RESULTS

Sixteen studies met the inclusion criteria, with 866 SMOs in 851 patients. Mean age of patients was 53.6 (range 17-79) years, and mean follow-up was 49.1 (range 8-168) months. Of the arthritic ankles (646 ankles), 11.1% were classified as Takakura stage I, 24.0% as stage II, 59.9% as stage III and 5.0% as stage IV. The overall MCMS was 55.2 ± 9.6 (fair). Eleven studies (657 SMOs) reported on "survivorship" of SMO, before arthrodesis (2.7%), or total ankle replacement (TAR) (5.8%) was required. Patients required AA after an average of 44.6 (range 7-156) months, and TAR after 36.71 (range 7-152) months. Hardware removal was required in 1.9% and revision in 4.4% of 777 SMOs. Mean AOFAS score was 51.8 preoperatively, improving to 79.1 postoperatively. Mean VAS was 6.5 preoperatively and improved to 2.1 postoperatively. Complications were reported in 5.7% (44 out of 777 SMOs). Soft tissue procedures were performed in 41.0% (310 out of 756 SMOs), whereas concomitant osseous procedures were performed in 59.0% (446 out of 756 SMOs). SMOs performed for valgus ankles failed in 11.1% of patients, vs 5.6% in varus ankles (p < 0.05), with disparity between the different studies.

CONCLUSIONS

SMOs combined with adjuvant, osseous and soft tissue, procedures, were performed mostly for arthritic ankles of stage II and III, according to the Takakura classification and offered functional improvement with low complication rate. Approximately, 10% of SMOs failed and patients required AA or TAR, after an average of just over 4 years (50.5 months) after the index surgery. It is debatable whether varus and valgus ankles treated with SMO reveal different success rates.

Changes in the subtalar joint alignment after supramalleolar osteotomy for varus ankle arthritis

BACKGROUND

The subtalar joint may compensate for tibio-talar deformity, but what would happen to the joint after the deformity was corrected is not well known. Supramalleolar osteotomy (SMOT) is an effective procedure for the treatment of varus deformity of ankle arthritis. The objective of this study was to investigate the subtalar joint alignment pre and postoperatively following SMOT, and the factors which influenced the alignment of the subtalar joint.

METHODS

Thirty-one patients with varus ankle arthritis (Takakura stage 2, 3a and 3b) who were treated using SMOT were retrospectively reviewed. The subtalar and ankle joint alignment was measured on weightbearing radiograph and weightbearing computerized tomography (WBCT).

RESULTS

The foot and ankle offset (FAO), tibial articular surface angle (TAS), tibio-talar surface angle (TTS), and subtalar vertical angle (SVA) were significantly corrected (P＜0.05). The subtalar inclination angle (SIA) decreased in 19 patients and increased in the other 12 cases after the SMOT (P＜0.001). The shift of subtalar joint (ΔSIA) showed an inverse correlation with the preoperative FAO (P＜0.001, r = -0.621).

CONCLUSIONS

The shift of subtalar joint after SMOT could maintain the neutral position of the hindfoot and showed a negative correlation with the preoperative FAO. The ΔSIA was greater in the severer preoperative hindfoot deformity.

LEVEL OF EVIDENCE

Level IV, case series.

Subchondral bone cysts remodel after correction of varus deformity in ankle arthritis

BACKGROUND

Subchondral bone cysts (SBCs) of the talus are frequently observed in ankle osteoarthritis (OA). It is unclear whether the cysts need direct treatment after correction of the varus deformity in ankle OA. The purpose of this study is to investigate the incidence of SBCs and the change after supramalleolar osteotomy (SMOT).

METHODS

Thirty-one patients treated by SMOT were retrospectively reviewed, and 11 ankles had cysts preoperatively. After SMOT without management of the cysts, the evolution of cysts was evaluated on weightbearing computerized tomography (WBCT). The American Orthopaedic Foot and Ankle Society (AOFAS) clinical ankle-hindfoot scale and a visual analog scale (VAS) were compared.

RESULTS

At baseline, the average cyst volume was 65.86 ± 60.53 mm3. The number and volume of cysts were reduced dramatically (P＜.05), and the cysts vanished in 6 ankles after the SMOT. The VAS and AOFAS scores improved significantly after SMOT (P＜.001), there was no significant difference between ankles with cysts and without cysts.

CONCLUSIONS

The SMOT alone without direct treatment of the SBCs led to a decrease in the number and volume of SBCs in varus ankle OA.

LEVEL OF EVIDENCE

Level IV, case series.

Supramalleolar osteotomy for the treatment of ankle osteoarthritis leads to favourable outcomes and low complication rates at mid-term follow-up: a systematic review

PURPOSE

The purpose of this systematic review was to evaluate both the clinical and radiographic outcomes following supramalleolar osteotomy (SMO) in patients with ankle osteoarthritis, and to analyse the level of evidence (LOE) and quality of evidence (QOE) of the included studies.

METHODS

A systematic review of the MEDLINE, EMBASE, and Cochrane Library databases was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies reporting clinical data following SMO for the treatment of ankle osteoarthritis were included and assessed. The level and quality of evidence of the included studies were also evaluated.

RESULTS

Twenty-four studies with 1160 patients (1182 ankles) were included. Overall, 78.8% patients presented with post-traumatic ankle osteoarthritis. The weighted mean AOFAS score improved from 52.6 ± 9.7 (range 33.8-78.4) preoperatively to 78.1 ± 5.7 postoperatively at weighted mean follow-up of 50.4 ± 18.6 months (range 24.5-99.0).  The most frequently utilised radiographic parameter was the tibial anterior surface angle, which improved from a preoperative weighted mean of 86.3° ± 5.6° (range 76.0°-102.0°) to a postoperative weighted mean of 89.9° ± 3.7° (range 84.9°-99.6°). The complication rate was 5.1% with non-union as the most commonly reported complication (1.6%). Secondary procedures were carried out in 28.2% of patients, the most common of which was implant and hardware removal (17.6%). The failure rate was 6.8%. Two studies were LOE II, 3 studies were LOE III, and 19 studies were LOE IV. The mean Modified Coleman Methodology Score was 59.3 ± 6.6 and the mean MINORS criteria score of all the included studies was 9.5 ± 3.7.

CONCLUSION

This systematic review demonstrates good clinical and radiological outcomes, together with a low failure rate at mid-term follow-up following supramalleolar osteotomy in patients with ankle osteoarthritis. However, a moderate reoperation rate (28.2%) was reported. A low failure rate (6.8%) was reported, which must be interpreted in light of the shortcomings of the design of the included studies and a relatively short follow-up period. In addition, there is a low level and quality of evidence in the current literature with inconsistent reporting of data which underscores the need for further higher quality research to be conducted. Our review highlights that SMO may be an effective and safe procedure in the setting of early-to-intermediate-stage ankle osteoarthritis.

LEVEL OF EVIDENCE

IV.

Is there an optimal degree of correction for ankle varus deformity after supramalleolar osteotomy? A systematic review

BACKGROUND

There is no consensus on the angle targeted for in varus ankle deformity after supramalleolar osteotomy (SMOT). The aim of this study was to investigate which obtained correction has the best clinical outcome after valgus SMOT.

METHODS

A systematic review according PRISMA guidelines was conducted with studies being eligible for inclusion when published in English, German or Dutch, patients older than 18 years at study entrance, primary or posttraumatic varus ankle osteoarthritis, using any valgus SMOT technique, describing radiological alignment and clinical outcome at baseline and after at least 12 months follow-up. Risk of bias was assessed using the McMaster University Occupational Therapy Evidence-Based Practice Research Group quality assessment tool. The electronical databases PubMed, EMBASE and Cinahl were used as data sources. Included cohorts were categorized according to the mean obtained medial distal tibia angle (MDTA; ranged between 87° and 100°). A linear mixed effect model was used for individual patient data to assess the association between the MDTA and the (difference in) clinical outcome.

RESULTS

Thirty studies including 33 patient cohorts with 922 ankles were identified. At a mean follow-up of 4 years no differences in clinical outcome between correction categories were found. Individual data of 34 ankles showed no relationship between obtained MDTA and clinical outcome either.

CONCLUSION

This review could not demonstrate an optimal degree of correction after valgus SMOT. Results were hampered by biased low quality studies and the widespread use of unreliable 2D alignment measures such as the MDTA.