Functional and radiological medium term outcome following supramalleolar osteotomy for asymmetric ankle arthritis- A case series of 33 patients

[Effectiveness and risk factors of supramalleolar osteotomy in treatment of varus-type ankle arthritis]

Objective

To assess the effectiveness of supramalleolar osteotomy (SMOT) as a therapeutic intervention for varus-type ankle arthritis, while also examining the associated risk factors that may contribute to treatment failure.

Methods

The clinical data of 82 patients (89 feet) diagnosed with varus-type ankle arthritis and treated with SMOT between January 2016 and December 2020 were retrospectively analyzed. The patient cohort consisted of 34 males with 38 feet and 48 females with 51 feet, with the mean age of 54.3 years (range, 43-72 years). The average body mass index was 24.43 kg/m ² (range, 20.43-30.15 kg/m ²). The preoperative tibial anterior surface angle (TAS) ranged from 77.6° to 88.4°, with a mean of 84.4°. The modified Takakura stage was used to classify the severity of the condition, with 9 feet in stage Ⅱ, 41 feet in stage Ⅲa, and 39 feet in stage Ⅲb. Clinical functional assessment was conducted using the Maryland sore, visual analogue scale (VAS) score, and psychological and physical scores in Health Survey 12-item Short From (SF-12). Radiology evaluations include TAS, talar tilt (TT), tibiocrural angle (TC), tibial medial malleolars (TMM), tibiocrural distance (TCD), tibial lateral surface angle (TLS), and hindfoot alignment angle (HAA). The results of clinical failure, functional failure, and radiology failure were statistically analyzed, and the related risk factors were analyzed.

Results

The operation time ranged from 45 to 88 minutes, with an average of 62.2 minutes. No complication such as fractures and neurovascular injuries was found during operation. There were 7 feet of poor healing of the medial incision; 9 pin tract infections occurred in 6 feet using external fixator; there were 20 cases of allograft and 3 cases of autograft with radiographic bone resorption. Except for 1 foot of severe infection treated with bone cement, the remaining 88 feet were primary healing, and the healing area was more than 80%. All patients were followed up 24-82 months, with an average of 50.2 months. Maryland score, VAS score, SF-12 psychological and physiological scores, and TAS, TC, TLS, TCD, TT, TMM, HAA, and Takakura stage were significantly improved at last follow-up ( P<0.05). Postoperative clinical failure occurred in 13 feet, functional failure in 15 feet, and radiology failure in 23 feet. Univariate analysis showed that obesity, TT>10°, and Takakura stage Ⅲb were risk factors for clinical failure, HAA≥15° and Takakura stage Ⅲb were risk factors for functional failure, and TT>10° was risk factor for radiographic failure ( P<0.05). Further logistic regression analysis showed that TT>10°, HAA≥15°, and TT>10° were risk factors for clinical failure, functional failure, and radiographic failure, respectively ( P<0.05).

Conclusion

SMOT is effective in the mid- and long-term in the treatment of varus-type ankle arthritis, but it should be used with caution in patients with obesity, severe hindfoot varus, severe talus tilt, and preoperative Takakura stage Ⅲb.

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.

Joint-Preserving Surgery in Varus Ankle Osteoarthritis

Ankle deformity is a disabling condition especially if concomitant with osteoarthritis (OA). Varus ankle OA is one of the most common ankle OA deformities. This deformity usually leads to unequal load distribution in the ankle joint and decreases joint contact surface area, leading to a progressive degenerative arthritic situation. Varus ankle OA might have multiple causative factors, which might present as a single isolated factor or encompassed together in a single patient. The etiologies can be classified as post-traumatic (e.g., after fractures and lateral ligament instability), degenerative, systemic, neuromuscular, congenital, and others. Treatment options are determined by the degree of the deformity and analyzing the pathology, which range from the conservative treatments up to surgical interventions. Surgical treatment of the varus ankle OA can be classified into two categories, joint-preserving surgery (JPS) and joint-sacrificing surgery (JSS) as total ankle arthroplasty and ankle arthrodesis. JPS is a valuable treatment option in varus ankle OA, which should not be neglected since it has showed a promising result, optimizing biomechanics and improving the survivorship of the ankle joint.