We retrospectively evaluated the postoperative clinical outcomes in patients with tumors and tumor-like lesions of the foot and ankle. As reported earlier, tumors of the foot and ankle form a small proportion of musculoskeletal tumors (5–10%), the incidence of malignant tumors being extremely lower than the benign ones 8,9,14,18−20. Comparable to the existing literature describing the pattern of distribution of tumors in this region 8,9, bone lesions in our study were significantly more in young males than soft tissue lesions. Osteochondroma (22%), enchondroma (18%), and bone cysts (16%) account for more than half of benign bone tumors. Benign bone lesions were treated with marginal excision or curettage. TGCT (33%) was the most common benign soft tissue lesion and was treated with marginal excision. As a previous study reported that TGCT, especially the diffused-type, was associated with high recurrence (33%) 21,22, 5 of our cases with diffused-type TGCT (23%) demonstrated a recurrent lesion. Ozdemir et al. reported a recurrence rate of 6.6% for tumors of the foot and ankle 1, we observed a similar recurrence rate of 8.5% (7.8% for bone lesions; 9.1% for soft tissue lesions).
The 5-year survival rate for malignant tumors of the foot and ankle is reported to be 80%, with 44–88% requiring amputation 2,23,24. In our study, 20% of patients of intermediate and malignancy at foot and ankle has shown the outcome of death of diseases, and 53% of the patients had been amputated, as previously reported. Usually, to fulfill the oncological goal of treatment, wide resection and reconstruction are warranted; however, when complete resection of the tumor is difficult or there is a high risk of local recurrence after resection, amputation of the foot or the leg is recommended 25. Malignant bone tumors of the forefoot should be treated locally with amputation at a level appropriate for the proximal extension of the tumor 26; accordingly, in three of our cases, amputations at the metatarsal and metatarsophalangeal disarticulation were performed in the first surgery, and neither of them reported recurrence. Additionally, postoperative complication, especially surgical site infection, occur in 2 to 5.1% in surgeries of the foot and ankle 27–29; as mentioned above, five of our patients (4.3%) developed wound problem, which is comparable to previous reports.
Because of the small-sized compartments of the foot and ankle region, it is easy to localize a mass and pain in this region. It is reported that the main complaints associated with tumors of the foot ankle were noticeable mass and pain 6,30,31. In our study, we observed that the pain improved significantly after the surgical treatment and that patients with bony lesions suffered from pain more than those with soft tissue lesions (Fig. 4). Since a bone lesion may be associated with pathological microfractures, the postoperative JSSF pain scores for bony lesions were significantly improved owing to the healing of the fracture.
Hitherto, there have been some epidemiological studies about tumors of this region 1–6, 8,9, which have demonstrated the diagnosis and distribution patterns of tumors of foot and ankle, and predicted factors for the grade of malignancy. However, none of them have reported the postoperative clinical and functional outcomes. We used the JSSF scale, which is a modified version of the American Orthopedic Foot and Ankle Society clinical rating system 32 for the Japanese people, to demonstrate the clinical and functional recovery after tumors and tumor-like lesions of the foot and ankle 12,13. Functional evaluation after surgical treatment of musculoskeletal tumors is usually done by the Musculoskeletal Tumor Society (MSTS) scoring system 33; however, the MSTS system is a scale for determining the physical and mental health status of patients with tumor at the limb and has difficulty evaluating the specific function of the foot and ankle. Therefore, the JSSF scale was used to evaluate the postoperative function of the foot and ankle in this study. We found that the pain and function were significantly improved postoperatively, suggesting that resection of the mass and disappearance of the pain may have led to better postoperative clinical outcomes in terms of walking, activities of daily living, and putting on their shoes. After limb-sparing surgery for malignancy of foot and ankle, preoperative and postoperative JSSF has shown no significant change.
This study has several limitations. First, we used a retrospective study design for analyzing clinical data. Second, we investigated only a small number of patients from a single institution without a control group; however, it was logistically not possible to have a strict control group since tumors of foot and ankle are extremely rare 1–3. Therefore, this study included various kinds of tumors and tumor-like lesions of the foot and ankle. In addition, since the distribution of tumors and tumor-like lesions of the foot and ankle in this study were similar to previous studies 8,9, the sufficient number of patients at a single institution might be analyzed. The strong point in a single institution is that our institution, which is a musculoskeletal tumor referral center, could determine the consistent management of treatment. Third, only patients who underwent excision surgery were included in the study, and we excluded patients with benign lesions with conservative treatment (e.g., hemangioma, ganglion, etc.). These patients with conservative treatment had been unchanged in pattern and size after several MRI exams or biopsies. Additionally, because most of the patients with conservative treatment had slight symptoms and less dysfunction, we could exclude them from this study. Fourth, the follow-up duration of some patients with malignant tumor was relatively short (range 18–82 months). Although we have the necessity to careful follow-up continuously, all patients had been continuous disease free at the final visit. Finally, the JSSF scale was inappropriate to assess the amputated legs, so we excluded them in the analysis.