Question:
In patients with chronic lateral ankle instability, how effective are conservative or surgical interventions?
Data sources:
Studies were identified up to February 2010 in the specialized register of the Cochrane Bone, Joint and Muscle Trauma Group; the Cochrane Central Register of Controlled Trials; MEDLINE; EMBASE/Excerpta Medica; and CINAHL. Reference lists of articles were scanned and researchers in the field were contacted.
Study selection and assessment:
Studies were included if they were randomized controlled trials (RCTs) that evaluated any conservative or surgical treatments for chronic lateral ankle instability (whether functional or mechanical). Studies dealing exclusively with children or patients with congenital deformities, degenerative conditions, or acute injury to the lateral ligament were excluded. Study quality was assessed by reviewing risk of bias items (generation of random allocation sequence, allocation concealment, blinding, incomplete outcome data, and selective reporting) and assigning a Grading of Recommendations Assessment, Development and Evaluation (GRADE) score.
Main outcome measures:
The primary outcome measures were functional outcome, as assessed with an ankle scoring system, and patient-derived subjective instability. Secondary outcomes included recurrent injury, use of external support, pain, swelling, time to return to work or sport, mechanical laxity, and ankle motion.
Main results:
Ten RCTs (n = 388) met the inclusion criteria. GRADE assessments were moderate in six RCTs and poor in four RCTs. Four trials evaluated neuromuscular training: three compared four-week supervised training sessions comprising balance exercises with no training, and one compared bidirectional with unidirectional pedaling on a bicycle ergometer. Three RCTs showed an improvement in functional outcome with neuromuscular training (one RCT [n = 19], mean difference in the Ankle Joint Functional Assessment Tool = 3.00, 95% confidence interval [CI] = 0.3 to 5.70; two RCTs [n = 56], pooled mean difference in the Foot and Ankle Disability Index [FADI] = 8.83, 95% CI = 4.46 to 13.20, and pooled mean difference in the FADI Sport = 11.59, 95% CI = 6.48 to 16.69). The RCT (n = 20) comparing bidirectional with unidirectional pedaling showed no difference in function on the modified Karlsson ankle score.
Four RCTs (n = 219) compared different surgical procedures. Two compared nonanatomic with anatomic reconstruction, one compared anatomic reinsertion with anatomic imbrications, and one compared dynamic tenodesis with static tenodesis. The two RCTs (n = 60) evaluating nonanatomic procedures in short-term follow-up showed no difference in subjective instability (pooled relative risk [RR] = 2.49, 95% CI = 0.39 to 15.83) or pain (pooled RR = 2.00, 95% CI = 0.41 to 9.86) compared with anatomic reconstruction. One RCT (n = 60) showed no difference between reinsertion and imbrications in subjective instability (RR = 1.00, 95% CI = 0.15 to 6.64), chronic pain (RR = 0.25, 95% CI = 0.03 to 2.11), or nonreturn to previous athletic activity (RR = 0.71, CI = 0.25 to 2.00). One RCT (n = 99) comparing dynamic with static tenodesis showed more functional limitation (RR = 8.62, 95% CI = 1.97 to 37.77) and “distortion trauma” (or repeat sprain) (RR = 12.92, 95% CI = 1.64 to 101.93) with dynamic tenodesis.
Two RCTs (n = 70) compared early mobilization in a brace with immobilization in a cast after surgery. Fewer patients receiving early mobilization had unsatisfactory function as measured by the Karlsson score (two vs. seven patients), but the difference did not reach significance (RR = 0.29, 95% CI = 0.06 to 1.28). In one RCT (n = 40), time to return to work and sport were both shorter in the early mobilization group than in the later mobilization group (mean difference: 95% CI = 0.94 to 3.06, respectively, for the two-week difference in return to work; and 1.51 to 4.49, respectively, for the three-week difference in return to sports). In the second RCT (n = 30), only time to return to sport was shorter in the early mobilization group (p < 0.05). One RCT showed improved range of ankle motion in the early mobilization group after six weeks (p < 0.001), but there was no difference between groups at the time of the final (two-year) follow-up.
Conclusions:
In patients with chronic lateral ankle instability, beneficial outcomes are observed over at least the time period of training with neuromuscular training and with early mobilization in a brace after surgery. While comparisons of different surgical procedures showed similar results, dynamic tenodesis was associated with more functional problems and repeat sprains than those associated with static tenodesis, and nonanatomic procedures were associated with more nerve-related complications than those associated with anatomic procedures.
Source of funding: Mitek DePuy, the Netherlands.
For correspondence: Dr. J.S. de Vries, Department of Orthopaedic & Trauma Surgery, Ziekenhuis Amstelland, Laan van de Helende Meesters 8, 1186 AM Amstelveen, Noord-Holland, the Netherlands. E-mail address: jsdevries1@gmail.com
For a glossary of terms for evidence-based orthopaedics, go to jbjs.org/ebo_glossary.
Disclosure: None of the authors received payments or services, either directly or indirectly (i.e., via his or her institution), from a third party in support of any aspect of this work. One or more of the authors, or his or her institution, has had a financial relationship, in the thirty-six months prior to submission of this work, with an entity in the biomedical arena that could be perceived to influence or have the potential to influence what is written in this work. No author has had any other relationships, or has engaged in any other activities, that could be perceived to influence or have the potential to influence what is written in this work. The complete Disclosures of Potential Conflicts of Interest submitted by authors are always provided with the online version of the article.
While one presumes that functional rehabilitation, surgical reconstruction, or functional rehabilitation after surgical reconstruction may be beneficial in treating chronic lateral ankle instability, little hard evidence exists to confirm this presumption. Four previous systematic reviews1-4 evaluating conservative treatment concluded that neuromuscular training is effective for chronic ankle instability, but no systematic review for surgical treatment exists, to our knowledge.
This systematic review by de Vries and colleagues used strict inclusion and exclusion criteria in identifying RCTs from specialized registers and reference lists to assess effectiveness of treatment (nonoperative-early functional rehabilitation versus none, and different surgical techniques) for chronic lateral ankle instability in skeletally mature individuals. None of the ten RCTs included in the study compared surgery alone with functional rehabilitation, or surgery plus functional rehabilitation with rehabilitation alone. For four RCTs evaluating neuromuscular training, a high risk of detection bias resulted in a GRADE score of “moderate.” For comparison of different surgical procedures (four RCTs), the GRADE assessment was “poor” and, for early mobilization compared with casting after surgical treatment (two RCTs), a high risk of bias resulted in a GRADE score of “moderate.” Conclusions from this review must be taken in the context of small study populations in the included studies, moderate-to-high risk of bias, and clinical heterogeneity.
In conclusion, neuromuscular training alone improves chronic lateral ankle instability in the short term, but long-term outcomes are unclear. Insufficient evidence exists to support any one specific surgical technique (i.e., anatomic versus nonanatomic) although the dynamic tenodesis had substantial limitations. Neuromuscular training postoperatively rather than cast immobilization for six weeks leads to increased function, leading to reduced time to return to work and sports.