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

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.

Analysis of radiologic parameters and clinical outcomes in supramalleolar osteotomy for varus ankle osteoarthritis: A novel method for evaluating ankle alignment

BACKGROUND

Solely relying on the tibial ankle surface (TAS) angle for determining the mechanical ankle axis might be insufficient. We introduce a novel method to determine the distance from the center of the talus to the tibial axis (TTD). This study aimed to investigate the association between clinical outcomes and radiological changes before and after supramalleolar osteotomy (SMO), including TAS angle, talar tilt (TT) angle, tibiotalar surface (TTS) angle and TTD.

METHODS

Seventy patients who received SMO were enrolled. Radiological changes were measured using weight-bearing anteroposterior imaging. The percentage of talar center displacement (TTDP) was calculated as the difference between postoperative and preoperative TTD, divided by talar width (TW). Clinical assessments were performed using the American Orthopedic Foot and Ankle Society ankle-hindfoot (AOFAS) scale. Differences in the aforementioned indicators before and after the operation were analyzed. We defined ΔAOFAS, ΔTAS, ΔTT and ΔTTS as the difference between postoperative and preoperative values.

RESULTS

ΔTTS correlated with ΔAOFAS (r = 0.40, p = 0.008), as did TTDP (r = 0.32, p = 0.035). No correlation was observed between ΔAOFAS and ΔTAS. In the comparison between groups, patients with a TTDP greater than 26.19 exhibited a significantly greater ΔAOFAS. The high intraclass correlation coefficient indicated good reliability of the novel method.

CONCLUSION

Solely relying on the TAS angle for tibial correction was insufficient. We found TTD as a novel method to evaluate mechanical ankle joint axis. TTDP and ΔTTS both positively correlated with ΔAOFAS, indicating the usefulness of these radiologic parameters.

Mechanical Ankle Joint Axis Point on a Hip-to-Calcaneus Long Leg View Correlates Significantly With SPECT/CT Activation in Symptomatic Asymmetric Ankle Osteoarthritis

BACKGROUND

Asymmetric joint load is the main cause of development of ankle osteoarthritis (OA). Realignment surgery aims to transfer ankle joint load from the degenerative area toward the uninvolved area. Determination of the optimal shift is still challenging. When the degenerative area is correlated to the ankle joint mechanical axis establishing an optimal target angle for corrective surgery may become more feasible. The primary aim of our study was to investigate if the area of ankle joint activation on single-photon emission computed tomography and conventional computed tomography (SPECT/CT) imaging correlates with the mechanical ankle joint axis point (MAJAP).

METHODS

In this cross-sectional study, patients 18 years or older with symptomatic asymmetric ankle OA and a hip-to-calcaneus long leg view with SPECT/CT of the affected ankle were eligible for inclusion. Primary outcome was MAJAP divided into 3 alignment categories (medial shift, neutral, lateral shift). SPECT/CT activation was determined in 8 different areas of the ankle joint. A Spearman rho correlation coefficient was calculated to investigate the relationship between the alignment categories and SPECT/CT activation in the 8 areas.

RESULTS

Forty-nine patients (mean age 58.8 [SD 10.0] years) with 52 ankles with moderate to severe asymmetric OA were included. A significantly (Spearman rho -0.379 [P = .006] and Spearman rho -0.279 [P = .045]) higher proportion of ankles with radioisotope uptake in the anteromedial ankle joint areas (zones 1 and 5) was seen in the medial shift category. A significantly (Spearman rho .312 (P = .025)) higher proportion of ankles with radioisotope uptake in the anterolateral ankle joint area (zone 8) was seen in the lateral shift category.

CONCLUSION

We found in this patient group that the area of SPECT/CT uptake in asymmetric ankle OA was associated to MAJAP measured on hip-to-calcaneus weightbearing views, although the strength of the correlation is weak to moderate. Consequently, nonweightbearing metabolic SPECT/CT radiotracer uptake has the potential to help determine the area to unload in ankle joint-preserving alignment surgery.

Optimizing Outcomes in Distal Tibial Deformity Correction: The Role of Supramalleolar Osteotomy with Computer-assisted Hexapod External Fixator

OBJECTIVE

Distal tibial deformities can significantly impact patients if left uncorrected, often leading to pain, alterations in gait, and the eventual development of post-traumatic arthritis. The criteria for surgical correction in these patients continues to be a subject of debate, while supramalleolar osteotomy (SMO) is an effective method for correcting distal tibial deformities. The purpose of this study was to evaluate and compare the clinical results of SMO using internal fixation or using computer-assisted hexapod external fixator in the treatment of distal tibial deformity.

METHODS

A retrospective study was conducted on 290 patients who underwent SMO between June 2015 and January 2023. Forty-four patients met the inclusion and exclusion criteria. Among the participants, 19 underwent SMO combined with a computer-assisted hexapod external fixator, while 25 received SMO with plate and screw internal fixation. The tibial anterior surface (TAS) angle, tibial lateral surface (TLS) angle, the tibiotalar (TT) angle and the talocrural (TC) angle were assessed on weight-bearing X-ray films. Functional assessments were performed according to the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score.

RESULTS

The study followed patients for an average duration of 31.7 ± 15.3 months, with a range from 12 to 67 months. Successful bone union was achieved in all cases. For patients treated with the computer-assisted hexapod external fixator, significant improvements were observed: the mean deviation in sagittal plane deformity parameters decreased from 14.3 ± 10.4 degrees preoperatively to 2.8 ± 3.8 degrees postoperatively (p < 0.05). Similarly, coronal plane deformity parameters showed a reduction from 25.9 ± 22.5 degrees preoperatively to 5.9 ± 11.0 degrees postoperatively (p < 0.05). The AOFAS ankle-hindfoot score improved markedly from 66.0 ± 14.9 to 86.1 ± 11.7 points (p < 0.05). For patients undergoing internal fixation, the absolute difference in coronal plane parameters improved from 15.4 ± 12.6 degrees preoperatively to 3.7 ± 3.4 degrees postoperatively (p < 0.05). A significant enhancement in AOFAS ankle-hindfoot score was also noted, increasing from 68.3 ± 14.3 points to 79.4 ± 13.5 points (p < 0.05). There were no significant differences in gender, side, follow-up time, postoperative deviation of deformity, pre- or postoperative AOFAS between the two groups.

CONCLUSION

In conclusion, comprehensive preoperative planning of SMO combined with either internal fixation or a hexapod external fixator for treating distal tibial deformities can achieve satisfactory outcomes. The utilization of a computer-assisted hexapod external fixator facilitates a gradual and precise correction process, which proved to be an effective and relatively safe method.

Reconstructive Surgery and Joint-Sparing Surgery in Valgus and Varus Ankle Deformities: A Comprehensive Review

Osteoarthritis (OA) of the ankle affects about 1% of the world’s adult population, causing an important impact on patient lives and health systems. Most patients with ankle OA can show an asymmetrical wear pattern with a predominant degeneration of the medial or the lateral portion of the joint. To avoid more invasive ankle joint sacrificing procedures, joint realignment surgery has been developed to restore the anatomy of the joints with asymmetric early OA and to improve the joint biomechanics and symptoms of the patients. This narrative, comprehensive, all-embracing review of the literature has the aim to describe the current concepts of joint preserving and reconstructive surgery in the treatment of the valgus and varus ankle early OA, through an original iconography and clear indications and technical notes.