Lateral Ligament Reconstruction with Allograft in Patients with Severe Chronic Ankle Instability 

SLR- March 2014- Oendirla Kamal

Reference:  Ventura; A. Terzaghi; C. Legnani; C. Borgo; E. Lateral Ligament Reconstruction with Allograft in Patients with Severe Chronic Ankle Instability. Archives of Orthopaedic and Trauma Surgery. December 2013; DOI 10.1007/s00402-013-1911-6

Scientific Literature Review

Podiatric Relevance: Management of severe chronic ankle instability poses a challenge to the podiatric surgeon. With severe chronic ankle instability, both the ATFL and CFL are involved. Many surgical techniques have been proposed for treatment of this pathology including direct anatomical repair and non-anatomical reconstruction. Since ligamentoplasty is noted to possess more stability than direct anatomical repair, it is a common surgical choice. The authors in this study focused on the success rate of allograft external ligamentoplasty.

Methods: This is a retrospective cohort study that was done on 10 patients with chronic lateral ankle instability who were treated with allograft external non-anatomic ligamentoplasty. Operative treatment was proposed to subjects with ankle giving-way symptoms unresponsive to at least six months of non-operative treatment. Only patients with positivity to both anterior drawer sign and talar tilt test were enrolled. Concomitant ATFL and CFL rupture was confirmed by MRI. Median age at surgery was 29.4 years (range 25–35). All subjects met the following inclusion criteria: age 18–45 years, absence of previous ankle surgery, cartilage defects less than grade III according to Outerbridge classification.

Surgical technique consisted of forming a tunnel with a 5 mm drill through the distal part of the lateral malleolus in a posterior-lateral to anterior-medial direction. A semitendinosus tendon allograft was used in six procedures and a long digitorum tendon allograft was used in the remaining four. The graft was cryopreserved at −80 °C and then it was reconstituted in 500 ml sterile saline solution with 250 mg of Rifampicin for 15 min at 40°C. Allograft was tested for gram-positive and negative microorganisms. It was cut to a size of approximately 20–28 cm and then doubled. The tendon graft was passed through the bone tunnel in the lateral malleolus and under the inferior extensor retinaculum. The graft was then first secured to the base of the fifth metatarsal bone close to the peroneus brevis distal insertion with the use of no. 2 absorbable sutures and then it was sutured back to itself distally. The foot was maintained in a neutral anatomical position while the sutures were progressively tightened until optimal tensioning was reached.

Results: Average follow-up time was 16.3 months (range 12–28months). AOFAS score increased from 67.0 pre-operatively to 86.5 post-operatively. Karlsson-Peterson score increased from 49.5 to 89.5 at follow-up. Tegner score increased from 6.5 to 7.0 at follow up. All three scores improvement were statically significant (p <0.001). Articular stability was assessed by the Sefton scale (improved from 4.0 to 2.0), positive anterior drawer sign and talar tilt test (improved from 100 percent to 0 percent) also documented a significant improvement (p < 0.001) from pre-operative status. The average radiographic anterior talar translation and talar tilt angle under varus stress decreased significantly from 8.7 mm to 4.0 mm and 12.3° to 3.3°, respectively at follow-up (p <0.001). Sagittal ROM was full in nine cases: one patient experienced 15° dorsiflexion limitations. Four patients (40 percent) experienced subtalar joint stiffness; subtalar joint motion was limited in all patients at objective examination. One patient reported minimal degenerative arthritic changes. Nine patients (90 percent) rated the success of their surgery as good to excellent. Only one patient judged the result as fair. All patients stated they would have undergone surgery again.