SLR - December 2016 - Anson Chu

Modified Broström Procedure for Chronic Lateral Ankle Instability in Patients with Generalized Joint Laxity

Reference: Xu HX, Lee KB. Modified Broström Procedure for Chronic Lateral Ankle Instability in Patients With Generalized Joint Laxity. Am J Sports Med. 2016 Aug 5.

Scientific Literature Review

Reviewed By: Anson Chu, DPM
Residency Program: Grant Medical Center

Podiatric Relevance: Chronic lateral ankle instability is an issue within the podiatric patient population that often calls for surgical intervention. Studies have shown that anatomic repair utilizing the Modified Broström procedure is effective in treating chronic lateral ankle instability when conservative treatments have failed. However, few studies have examined the effects of the Modified Broström procedure in those with generalized joint laxity or in those with increased joint range of motion relative to the normal population. Generalized joint laxity does not include those with genetic diseases that include hyperlaxity, such as Marfan syndrome, Ehlers-Danlos syndrome, etc. In this study, the authors address the clinical results of patients with generalized joint laxity after the Modified Broström procedure, which may be a significant consideration for preoperative planning.

Methods: The study was a retrospective review of patients undergoing the Modified Broström procedure by a single surgeon from January 2005 to December 2012. Using the Beighton criteria (score greater than 5) for establishing generalized joint laxity, 44 patients with generalized joint laxity were included in the study. The 44 patients were matched with 56 patients without generalized joint laxity using age and body mass index (BMI). The group with laxity had a mean follow-up duration of 43.3 months, and the nonlaxity group had a mean follow-up duration of 42.9 months. The failure rate was assessed at final follow-up. Outcomes were assessed comparing the Karlsson score, AOFAS score, talar tilt angle and anterior talar translation preoperatively and postoperatively.

Results: Failure rate, as defined by rerupture and recurrent lateral ankle instability, was 5/44 patients (11.4 percent) in the group with generalized joint laxity and 1/56 patients in the nonlaxity group. Mean Karlsson scores from preoperative assessment to final follow-up improved from 53.2 to 87.4 in the laxity group and 53.9 to 94.1 in the nonlaxity group. Mean AOFAS scores from preoperative assessment to final follow-up improved from 60.9 to 89.5 in the laxity group and 62.6 to 94.8 in the nonlaxity group. The mean talar tilt angle improved from preoperative measurement to final follow-up from 12.5 degrees to 7.3 degrees in the laxity group and 10.8 degrees to 5.2 degrees in the nonlaxity group. Anterior talar translation improved from preoperative measurement to final follow-up from 8.8 mm to 6.0 mm in the laxity group and 8.5 mm to 5.0 mm in the nonlaxity group.

Conclusions: The authors of this study concluded that the patient population with generalized joint laxity had inferior outcome measures as well as higher failure rates than their counterparts without increased joint laxity. The information from this study may prove useful for those treating chronic ankle instability. Although the outcome measures for those with generalized joint laxity were inferior to the nonlaxity group, the Modified Broström procedure still had good to excellent outcome measures per the mean AOFAS and Karlsson scores regardless of the group. There were also noted improvements in the mean talar tilt angle and anterior talar translation within both groups. Thus, the Modified Broström procedure continues to show the effectiveness of treating chronic lateral instability as a primary operation should conservative measures fail. However, due to the increased number of rerupture and recurrent lateral ankle instability in the group with generalized joint laxity, it may be a risk factor to consider when utilizing the Modified Broström procedure. Patients who may have increased Beighton scores that help assess for generalized joint laxity should be taken into consideration for preoperative planning and additional augmentation of lateral ligaments in addition to the Modified Broström procedure, which may prove beneficial.

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