BACKGROUND: Posterior ankle impingement syndrome (PAIS) is sometimes complicated by bilateral cases and lateral ankle ligament injuries. Reports on bilateral surgery for PAIS and simultaneous surgery for lateral ankle ligament injury are scarce in the literature.
METHODS: We present a 2-year follow-up of 76 athletic patients who underwent endoscopic hindfoot surgery for PAIS. Patients were divided into those who underwent unilateral or simultaneous bilateral surgery and PAIS surgery alone or simultaneous bilateral PAIS surgery without arthroscopic ankle lateral ligament repair.
RESULTS: All patients returned to full athletic activities postoperatively. There was no difference in all subscales of the SAFE-Q score between groups except for mean days after surgery for full return to athletic activities.
CONCLUSIONS: Simultaneous bilateral surgery and simultaneous arthroscopic lateral ankle ligament repair had no negative effect on subjective clinical evaluation 2 years after surgery in hindfoot endoscopic surgery for PAIS.
METHODS: III, retrospective case-control study.

Endoscopic flexor hallucis longus (FHL) tendon transfer to replace the calcaneal tendon is being increasingly performed. The main advantage is minimisation of approach-related morbidity. Fixation of the FHL tendon is usually achieved with a tenodesis screw placed in a vertical calcaneal tunnel. Here, we describe an endoscopic technique with FHL fixation by tenodesis in a horizontal calcaneal tunnel combined with suturing of the tendon onto itself. LEVEL OF EVIDENCE: IV.

Septic retrocalcaneal bursitis (RB) is extremely rare with no reports on surgical treatment. Here, we describe a rare case of septic RB in a 14-year-old male soccer player who was treated with hindfoot endoscopic bursectomy. A 14-year-old male soccer player complained of right heel pain without trauma histories when he was playing a soccer. Based on physical examination, radiological findings and laboratory results, we diagnosed the patient with septic RB and started to treat with conservative treatment including a non-weightbearing splint and intravenous antibiotics therapy. However, his symptoms and laboratory results did not improve at 4 days after starting intravenous antibiotics therapy, and so we applied hindfoot endoscopic bursectomy for him. At 4 weeks after the surgery, he could return to the original sport at preinjury level without symptoms and complications. Septic RB in a 14-year-old male soccer player was successfully treated with hindfoot endoscopic bursectomy.

UNASSIGNED: Pigmented villonodular synovitis (PVNS) is a rare and benign proliferative lesion affecting synovial lining of joints, bursae, and tendon sheaths. Depending on the extent of synovial involvement, two forms are distinguished, diffuse, and localized. Intra-articular localized form of PVNS (LPVNS) presents as a nodular, well circumscribed, pedunculated, or sessile soft-tissue mass.
UNASSIGNED: We report a case of an unusual localization of LPVNS in posterior ankle recess in a 42-year-old male with concomitant anterior ankle impingement syndrome. To address both the posterior and the anterior ankle disorders the patient was treated with combined two-portal endoscopic hindfoot approach and anterior ankle arthroscopy within the same operative session. The hindfoot endoscopy encompassed complete removal of the localized mass, partial synovectomy of the area at the base of the lesion, removal of os trigonum, and a loose body impinged in the interval between tibia and fibula. The anterior ankle arthroscopy included removal of the osteophytes from the anterior distal tibia and dorsal talus. Patient continued his normal daily and sporting activities without any restrictions and no recurrence of LPVNS 2 years after the surgery.
UNASSIGNED: PVNS is an important clinical entity that should always be thought of as a differential diagnosis when treating patients with ankle disorders. Hindfoot endoscopy, when performed by an experienced ankle surgeon, is a safe and effective procedure for LPVNS of the posterior ankle recess, when deemed amenable to complete resection.

BACKGROUND: A common cause of posterior ankle pain is posterior ankle impingement syndrome (PAIS). Many studies about PAIS have been conducted on special groups such as athletes and dancers; there has been no previous study of a nonathletic population. This study aimed to evaluate the causes and treatment methods of PAIS in the nonathletic population and compare it with the athletic population.
METHODS: A retrospective review was performed and 28 of 46 patients (60.9%) recovered from two-staged conservative therapy. In the 18 patients (39.1%) who did not benefit from 3 months of conservative treatment, hindfoot endoscopy was applied. Patient data, including sex, age, occupation, and sports activity level, were recorded. Visual analog scale, American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot, and Tegner scores were recorded. Patient satisfaction was assessed with a 4-point Likert scale. Complications were recorded.
RESULTS: Mean follow-up was 27.4 months. At final follow-up, the AOFAS hindfoot score had significantly improved from 66.4 to 96.8 (P < .001). The Tegner score improved significantly from 4.6 to 8.8 (P < .001). The visual analog scale score was 6.4 and increased to 0.9 (P < .001). Using the 4-point Likert scale for patient satisfaction, 13 (72.2%) stated that the surgical procedure was excellent and five (27.8%) good. Mean time to return to work was 4.2 weeks. Sural nerve dysesthesia was seen in two patients (11.1%).
CONCLUSIONS: This is the first study to evaluate PAIS in the nonathletic population. Conservative treatment showed good results as nearly two-thirds of the patients recovered. Hindfoot endoscopy in those not responding to conservative therapy is a successful treatment with low complication rates.

OBJECTIVE: The purpose of the present anatomical study was to define the exact morphology of the posterior fibulotalocalcaneal ligament complex (PFTCLC), both for a better orientation and understanding of the anatomy, especially during hindfoot endoscopy.
METHODS: Twenty-three fresh frozen specimens were dissected in order to clarify the morphology of the PFTCLC.
RESULTS: In all specimens, the ligament originated from the posteromedial border of the lateral malleolus between the posterior tibiofibular ligament (superior border) and the calcaneofibular ligament (CFL), (inferior border). This origin functions as the floor for the peroneal tendon sheath. The origin of the PFTCLC can be subdivided into two parts, a superior and inferior part. The superior part forms an aponeurosis with the superior peroneal retinaculum and the lateral septum of the Achilles tendon. From this structure, two independent laminae can be identified. The inferior part of the origin has no role in the aponeurosis and ligamentous fibres run obliquely to insert in the lateral surface of the calcaneus, in the same orientation as the CFL, but slightly more posterior, which was a consistent finding in all examined specimens. The PFTCLC is maximally tensed with ankle dorsiflexion and is located within the fascia of the deep posterior compartment of the leg.
CONCLUSIONS: The PFTCLC is part of the normal anatomy of the hindfoot and therefore should be routinely recognized and partly released to achieve access to the posterior ankle anatomical pathology, relevant for hindfoot endoscopy. The origin of the ligament complex forms the floor for the peroneal tendon sheath. The superior part of the origin plays a role in the formation of an aponeurosis with the superior peroneal retinaculum and the lateral septum of the Achilles tendon.

UNASSIGNED: Operative management of chronic Achilles tendon ruptures is challenging, and numerous techniques have been described. Risk of infection and wound breakdown have been described after open techniques, and minimally invasive methods have been proposed to avoid them. The aim of this study was to describe the clinical and radiological results obtained after endoscopic flexor hallucis longus (FHL) tendon transfer in patients with chronic Achilles tendon rupture.
UNASSIGNED: Between 2012 and 2015, a total of 22 patients were endoscopically treated for chronic Achilles tendon rupture. Mean age was 69 years (range, 59-84 years). Mean follow-up was 30.5 months (range, 18-46 months). Preoperative magnetic resonance imaging (MRI) was obtained and tendon gap measured. An MRI was obtained at 9 to 12 months following surgery to evaluate Achilles tendon changes.
UNASSIGNED: Preoperative MRI examination showed a mean tendon gap of 6.3 cm (range, 3-10.7 cm). The MRI control was obtained only in 12 patients, and a normal or close to normal Achilles tendon was observed in all but 1 patient. The mean American Orthopaedic Foot & Ankle Society score increased from 55 preoperatively (range, 26-75) to 91 (range, 74-100) at final follow-up. All patients returned to their daily activities without difficulties. No patients reported complaints or symptomatic deficits of great toe flexion strength. No major complications were encountered.
UNASSIGNED: Chronic Achilles tendon ruptures were successfully treated by an all-endoscopic procedure. The endoscopically assisted FHL transfer provided excellent results while benefiting from the minimally invasive procedure advantages. However, it entailed some technical challenges and may not be suitable for less experienced surgeons.
UNASSIGNED: Level IV, retrospective case series.

The purpose of the present study was to quantify the learning curve for arthroscopic os trigonum excision using the log-linear model. Twenty-three consecutive feet underwent arthroscopic os trigonum excision and release of the flexor hallucis longus. The required time from the beginning of shaving of the soft tissue until completion of os trigonum excision and release of the flexor hallucis longus (van Dijk time) was recorded. Regression analysis was applied to predict the required time on the basis of the cumulative case volume after logarithmic transformation of both statistics. The mean required time was 35.2 (range 9 to 90) minutes. After logarithmic transformation, a significant linear correlation was observed between the required time and the cumulative case volume (p = .0043). The best-fit linear equation was calculated as log (y, estimated required time)  = -0.41 log (x, case volume) + 1.86, resulting in an estimated learning rate of 75.3% (= 2-0.41). The results showed an overall time reduction in arthroscopic os trigonum excision in support of a learning curve effect with an ~75% learning rate, indicating that the required time for arthroscopic os trigonum excision can decrease by ≤25% when the cumulative volume of cases has doubled.

BACKGROUND: Surgical management of large talar dome cysts is challenging due to increased morbidity by associated cartilage damage and malleolar osteotomy. The purpose of this study is to evaluate the clinical and radiological outcome of endoscopic curettage and bone graft for large talar dome cysts.
METHODS: This is a retrospective analysis of data for eight patients (eight feet) who were treated by arthroscopic curettage and grafting for large talar dome cysts. Seven cases were treated by posterior ankle arthroscopy as the lesion was located posteriorly while one case was treated by anterior ankle arthroscopy as the lesion was breached anteriorly.
RESULTS: The final diagnosis, was; large osteochondral lesion of talus (two cases), aneurysmal bone cyst (ABC) (two case), intra-osseous ganglion (two cases), Chronic infection in talus (one case) and angiomatous lesion of the talus (one case). The mean follow up period was 18.3 (±3.06 SD) months (range 16-25 months). The median preoperative AOFAS score was 74.5 (±5.34 SD) points. The mean postoperative AOFAS score at one year follow up was 94.6 (±2.97 SD) points. None of the patient had recurrence of the lesion during follow up. Return to normal daily activity was achieved at 11.25 (±2.37 SD) weeks.
CONCLUSIONS: In this short case series study, large talar dome bony cysts of different pathologies including aneurysmal bone cysts could be treated effectively by endoscopic curettage and bone grafting with no recurrence no complications during the follow-up period.

OBJECTIVE: The presented study was performed to evaluate the midterm clinical and radiological results and complication rates of the first 40 patients with an ankle fusion through a posterior arthroscopic approach.
METHODS: Forty consecutive patients with end-stage post-traumatic ankle osteoarthritis were treated with posterior arthroscopic ankle fusion. All patients were assessed clinically as well as radiologically with a minimum follow-up of 2 years. The Foot and Ankle Ability Measure (FAAM) and Foot Function Index (FFI) were used to assess clinical improvement.
RESULTS: Clinical fusion was achieved in 40 patients within 3 months (100%), and radiological fusion was achieved in 40 patients at 12 months. Two screw mal-placements occurred. Both complications were solved following revision surgery. A significant improvement was noted for both the FAAM [median 38 (range 17-56) to 63 (range 9-84)] and FFI scores [median 66 (range 31-89) to 32 (range 11-98)] for all 40 patients.
CONCLUSIONS: The posterior arthroscopic ankle fusion is an effective and safe treatment option for end-stage post-traumatic ankle osteoarthritis at midterm follow-up.
METHODS: Prospective cohort study, Level IV.