Title: Outcomes after Standardized Screw Fixation Technique of Ankle Arthrodesis
Authors: Kennedy JG, Hodgkins CW, Brodsky, Bohne WH
Source: Clinical Orthopaedics and Related Research 2006; 447: 112-118.
PODIATRIC RELEVANCE:
Arthrodesis continues to be the standard of care for the treatment of end-stage arthrosis of the ankle joint. Although total ankle arthroplasty has made some advances in recent years, the longevity of the procedure has not been shown conclusively. Thus, ankle arthrodesis still remains the gold standard in the treatment for end-stage ankle arthritis. There have been more than forty different methods of obtaining ankle fusion presented in the literature to date which has made the reported outcomes varied and conflicting. This article suggests two hypotheses. First, it suggests that by using parallel screw fixation in the absence of potential thermal injury, and in the absence of supplemental allograft, high levels of ankle fusion can be obtained. Secondly, by standardizing the procedure, it would lead to fewer complications including non-union, delayed union, malunion, and progressive hindfoot arthrosis.
METHODS:
A retrospective study consisted of forty-one ankle fusions and forty patients who were operated on between 1987-2000. All patients had end-stage post-traumatic degenerative arthrosis of the ankle joint which was defined as loss of radiographic joint space with subchondral cysts and sclerosis. Patients with ankle arthritis secondary to rheumatoid disease, infection, tumors, or AVN as well as coexisting arthrosis and symptoms from the subtalar or talonavicular joints were excluded. The mean age of the patients at the time of surgery was 53 years (range 24-77 years).
All patients received the same form and orientation of fixation to achieve ankle arthrodesis. The author used two parallel retrograde 7.3 mm screws and a local fibular graft. After surgery, the patients were non-weightbearing with a fiberglass cast for six weeks and resumed gradual weightbearing after six weeks and progressed to full weightbearing during the following 4-6 weeks. The patients were evaluated with the AOFAS hindfoot score.
RESULTS:
Thirty-nine of the forty-one ankles fused solidly for a union rate of ninety-five percent. This was verified by radiographs that showed complete obliteration of the joint space with trabeculation present across the joint, and confirmed clinically with absence of ankle joint motion. The mean time to union was 14 weeks (range 6-46 weeks). Complications included nonunion (2/41), progressive subtalar arthritis (7/41), RSD (1/41), tibial stress fracture (1/41), a staphylococcal wound infection (1/41), and painful hardware (3/41). All forty-one ankles went on to fuse successfully with two patients requiring a second procedure. The mean postoperative AOFAS score was 80.6 points compared with 57.6 points preoperatively, with a mean improvement of 23.0 points. All but one patient said they would have surgery again.
COMMENTS:
Several methods of obtaining ankle fusion have been described, with many studies reporting on patient populations with varied diagnoses and various methods of fixation. This has made it difficult to standardize the arthrodesis procedure with a specific patient population. This study although retrospective in nature, is useful as it has shown that a high union rate can be achieved in a specific patient population without the aid of allograft. With these results, the levels of success with arthroscopic fusions and ankle joint replacement must compare favorably before they can be used as the primary treatment options.
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Disclaimer:
Scientific Abstract Monthly postings are submitted by podiatric surgical residents. The ideas presented are not the opinions of the American College of Foot and Ankle Surgeons (ACFAS), nor are they presented as facts. ACFAS presents this information without any warranty of any kind, expressed or implied, and is not liable for its accuracy nor for any loss or damage caused by the user's reliance on information obtained in these areas.