Chronic ankle instability: management of chronic lateral ligamentous dysfunction and the varus tibiotalar joint

A fibular notch approach for the treatment of ankle fractures involving the distal tibial plafond

Background

Although efficacy is related to many factors, the surgical approach is one of the most important intervention factors for complex ankle fractures. Ankle fractures involving the distal tibial plafond frequently present a surgical challenge in choosing which incisions will be best for surgical treatment. Here, we present an innovative fibular notch approach for the treatment of some specific ankle fractures and present a series of patients with either functional or radiographic outcomes.

Methods

Twenty-two patients with distal tibial plafond fractures with concomitant fibular and distal tibiofibular syndesmosis injuries were treated through a fibular notch approach in this retrospective study. The details of the surgical technique were reviewed from the operative notes. Relevant data were reviewed from the medical records. The quality of fractures and syndesmosis reduction was examined using CT scans, and lateral stability of the ankle was assessed by physical examination and stress radiographs. The American Orthopedic Foot and Ankle Society Ankle-Hindfoot Scale (AOFAS) score was implemented for clinical functional assessment.

Results

All surgeries were successfully performed via the fibular notch approach as the primary approach with excellent intraoperative visualization. Postoperative radiography revealed satisfying restoration of all fractures and syndesmosis. All fractures healed with an average time of 17.3 ± 3.6 weeks. Mild posttraumatic osteoarthritis (PTOA) was present in 4 patients. The average AOFAS score was 88.8 at the last follow-up.

Conclusions

The fibular notch approach is a safe and reliable approach for the treatment of specific ankle fractures involving the distal tibial plafond. This approach provides excellent direct visualization of the fragments and articular surface without significantly increasing iatrogenic injuries. Satisfactory radiographic and clinical results were observed, and further clinical and anatomical studies are recommended to ascertain the feasibility of this approach in the treatment of complex distal tibial fractures.

Treatment of ankle instability with an associated cavus deformity

This article reviews the role of cavus in foot and ankle injury and summarizes the current surgical and nonsurgical treatments. Recognition of foot position is crucial in the management of ankle instability associated with cavovarus. Correcting foot alignment with orthoses or surgery improves the mechanics of the ankle, reducing the risk of instability and potentially delaying the onset of posttraumatic ankle arthritis. Progressive steps in the correction alignment are described, with technical tips and strategies for dealing with chronic instability.

The role of the fibula in varus and valgus deformity of the tibia

It has been suggested that a supramalleolar osteotomy can return the load distribution in the ankle joint to normal. However, due to the lack of biomechanical data, this supposition remains empirical. The purpose of this biomechanical study was to determine the effect of simulated supramalleolar varus and valgus alignment on the tibiotalar joint pressure, in order to investigate its relationship to the development of osteoarthritis. We also wished to establish the rationale behind corrective osteotomy of the distal tibia.

We studied 17 cadaveric lower legs and quantified the changes in pressure and force transfer across the tibiotalar joint for various degrees of varus and valgus deformity in the supramalleolar area. We assumed that a supramalleolar osteotomy which created a varus deformity of the ankle would result in medial overload of the tibiotalar joint. Similarly, we thought that creating a supramalleolar valgus deformity would cause a shift in contact towards the lateral side of the tibiotalar joint. The opposite was observed. The restricting role of the fibula was revealed by carrying out an osteotomy directly above the syndesmosis. In end-stage ankle osteoarthritis with either a valgus or varus deformity, the role of the fibula should be appreciated and its effect addressed where appropriate.

Interventions for treating chronic ankle instability

BACKGROUND

Chronic lateral ankle instability occurs in 10% to 20% of people after an acute ankle sprain. Initial treatment is conservative but if this fails and ligament laxity is present, surgical intervention is considered.

OBJECTIVES

To compare different treatments, conservative or surgical, for chronic lateral ankle instability.

SEARCH STRATEGY

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CINAHL and reference lists of articles, all to February 2010.

SELECTION CRITERIA

All identified randomised and quasi-randomised controlled trials of interventions for chronic lateral ankle instability were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed risk of bias and extracted data from each study. Where appropriate, results of comparable studies were pooled.

MAIN RESULTS

Ten randomised controlled trials were included. Limitations in the design, conduct and reporting of these trials resulted in unclear or high risk of bias assessments relating to allocation concealment, assessor blinding, incomplete and selective outcome reporting. Only limited pooling of the data was possible.Neuromuscular training was the basis of conservative treatment evaluated in four trials. Neuromuscular training compared with no training resulted in better ankle function scores at the end of four weeks training (Ankle Joint Functional Assessment Tool (AJFAT): mean difference (MD) 3.00, 95% CI 0.3 to 5.70; 1 trial, 19 participants; Foot and Ankle Disability Index (FADI) data: MD 8.83, 95% CI 4.46 to 13.20; 2 trials, 56 participants). The fourth trial (19 participants) found no significant difference in the functional outcome after six weeks training programme on a cyclo-ergometer with a bi-directional compared with a traditional uni-directional pedal. Longer-term follow-up data were not available for these four trials.Four studies compared surgical procedures for chronic ankle instability. One trial (40 participants) found more nerve injuries after tenodesis than anatomical reconstruction (risk ratio (RR) 5.50, 95% CI 1.39 to 21.71). One trial (99 participants) comparing dynamic versus static tenodesis excluded 17 patients allocated dynamic tenodesis because their tendons were too thin. The same trial found that dynamic tenodesis resulted in higher numbers of people with unsatisfactory function (RR 8.62, 95% CI 1.97 to 37.77, 82 participants). One trial comparing techniques of lateral ankle ligament reconstruction (60 participants) found that operating time was shorter using the reinsertion technique than the imbrication method (MD -9.00 minutes, 95% CI -13.48 to -4.52). Two trials (70 participants) compared functional mobilisation with immobilisation after surgery. These found early mobilisation led to earlier return to work (MD -2.00 weeks, 95% CI -3.06 to -0.94; 1 trial) and to sports (MD -3.00 weeks, 95% CI -4.49 to -1.51; 1 trial).

AUTHORS' CONCLUSIONS

Neuromuscular training alone appears effective in the short term but whether this advantage would persist on longer-term follow-up is not known. While there is insufficient evidence to support any one surgical intervention over another surgical intervention for chronic ankle instability, it is likely that there are limitations to the use of dynamic tenodesis. After surgical reconstruction, early functional rehabilitation appears to be superior to six weeks immobilisation in restoring early function.

Salvage of severe ankle varus deformity with soft tissue and bone rebalancing

The etiology of ankle varus is multifactorial. Treatment recommendations after failed conservative care include hindfoot and ankle fusions or total ankle arthroplasty (TAA) with ligament rebalancing. The purpose of this study was to evaluate chronic varus ankle deformities through corrective calcaneal osteotomies and lateral soft tissue reconstruction. All skeletally mature patients with at least 5 degrees of ankle varus were included in the study. Pre and postoperative radiographs were retrospectively reviewed measuring talar tilt. All patients had a lateral closing wedge (Dwyer) calcaneal osteotomy, joint debridement, and lateral ankle ligament reconstruction. Eight feet were included in the study. The average follow-up time was 20.6 months. Six patients (six feet) were asymptomatic and did not have any additional surgery at their most recent follow-up. Two patients failed treatment, requiring surgical intervention for persistent pain and/or deformity. The average postoperative ankle varus correction overall was 4.9 degrees. We found ankle varus on average of less than 10 degrees can be reliably corrected with a combination of lateral ligament reconstruction and calcaneal osteotomy. Approximately 50% of the deformity was corrected when comparing pre and postoperative talar tilt values. In patients with varus deformity greater than 10 degrees preoperatively, persistent varus may occur.