Preliminary Experience With SPECT/CT to Evaluate Periarticular Arthritis Progression and the Relationship With Clinical Outcome Following Ankle Arthrodesis.

BACKGROUND: Single photon emission computed tomography combined with computed tomography (SPECT/CT) could potentially aid in diagnosing periarticular arthritis/activity and progression, facilitate effective treatment options, and evaluate the effect surgery has on the clinical outcome of patients with ankle arthritis. The goal of our study was to assess SPECT/CT activity in the ankle and periarticular joints before and after ankle fusion surgery and determine whether it was associated with clinical pain and function scores. METHODS: Thirty-four patients recruited into this study underwent either arthroscopic or open ankle fusion. X-ray (XR) and SPECT/CT imaging was obtained as well as completion of patient Ankle Osteoarthritis Scale (AOS) and 36-item Short Form Survey (SF-36) questionnaires preoperatively and at 6 months postoperatively. Ankle, subtalar, and talonavicular joint arthritis grading on XR and CT, along with SPECT/CT activity, was evaluated by 2 nuclear medicine radiologists. Data were assessed for normality and analyzed with the appropriate comparative test. P value was set at <.05. Thirty patients (31 ankles) completed follow-up and were analyzed. RESULTS: SPECT/CT activity showed no significant difference in the ankle joint at 6 months postoperatively while periarticular joint activity significantly increased (P < .05). Six months postoperatively, patients had significant improvements in their AOS and SF-36 scores (P < .05). SPECT/CT grading of all joints analyzed, however, was not associated with AOS or SF-36 scores preoperatively or at 6 months postoperatively. CONCLUSION: In this study, intensity of activity as evaluated by SPECT/CT in periarticular hindfoot joints in patients who had ankle arthrodesis was not associated with clinical/functional scores at 6 months postoperatively. LEVEL OF EVIDENCE: Level IV, diagnostic study.

Effect of a Controlled Ankle Motion Walking Boot on Syndesmotic Instability During Weightbearing: A Cadaveric Study.

BACKGROUND: Syndesmotic injuries can lead to long-term complications; hence, they require careful management. Conservative treatment is adequate when 1 syndesmotic ligament is injured, but surgery is often necessary to achieve articular congruity when 3 syndesmotic ligaments are ruptured. However, there is some controversy over the best treatment for 2-ligament injuries. PURPOSE: To evaluate the effect of a controlled ankle motion (CAM) walking boot on syndesmotic instability following iatrogenic isolated anterior inferior tibiofibular ligament (AiTFL) injury and combined AiTFL/interosseous ligament (IOL) injuries in a cadaveric simulated weightbearing model. STUDY DESIGN: Controlled laboratory study. METHODS: Ten cadaveric specimens were dissected to expose the tibial plateau and syndesmosis. The specimens were fitted to a custom-made device, and a reproducible axial load of 750 N was applied. Iatrogenic rupture of the syndesmotic ligaments (AiTFL + IOL) was done sequentially. Uninjured syndesmoses, isolated AiTFL rupture, and combined AiTFL/IOL rupture were compared with and without axial loading (AL) and CAM boot. The distal tibiofibular relationship was evaluated using a previously validated computed tomography scan measurement system. Wilcoxon tests for paired samples and nonparametric data were used. RESULTS: The only difference noted in the distal tibiofibular relationship during AL was an increase in the external rotation of the fibula when using the CAM boot. This was observed with AiTFL rupture (8.40° vs 11.17°; P = .009) and combined AiTFL/IOL rupture (8.81° vs 11.97°; P = .005). CONCLUSION: AL did not cause a significant displacement between the tibia and fibula, even when 2 ligaments were ruptured. However, the CAM boot produced a significant external rotation with 1 or 2 injured ligaments. CLINICAL RELEVANCE: Further studies are needed to assess the capacity of the CAM walking boot to prevent malreduction when external rotation forces are applied to the ankle. Moreover, special care should be taken during the fitting of the CAM boot to avoid overinflation of the cushions.