This study aimed to evaluate the presence of adipose tissue surrounding the flexor hallucis longus (FHL) tendon through gross dissection and magnetic resonance imaging (MRI). Grossly, we observed the FHL tendon and surrounding tissues in nine cadavers. Using MRI, we quantitatively evaluated each tissue from the horizontal plane in 40 healthy ankles. Macroscopic autopsy revealed the presence of adipose tissue behind the ankle joint between the FHL and fibula, and horizontal cross-sections showed an oval-shaped adipose tissue surrounding the tendon. The cross-sectional area on MRI was 14.4 mm2 (11.7-16.7) for the FHL tendon and 120.5 mm2 (100.3-149.4) for the adipose tissue. Additionally, the volume of the adipose tissue was 963.3 mm3 (896.2-1115.6). There is an adipose tissue around FHL tendon and maybe this close anatomical relationship might influence the function of the tendon and be involved in its pathologies.

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.

This study aimed to evaluate the surgical technique and long-term clinical outcomes of all-inside arthroscopic treatment for flexor hallucis longus (FHL) tendon impingement syndrome. We retrospectively evaluated 34 FHL tendon impingement syndrome patients with complete follow-up data who were admitted from June 2015 to August 2018 and underwent the all-inside arthroscopy technique. The subjects consisted of 20 (58.82%) males and 14 (41.18%) females, with a mean age of 32.7 ± 10.2 (range 21-52) years. The cases consisted of 19 (55.88%) right and 15 (44.12%) left feet. The mean disease duration was 18.5 ± 9.1 (range 10-43) months. The visual analogue scale (VAS), American Orthopaedic Foot & Ankle Society (AOFAS), Karlsson Ankle Functional Score (KAFS), and 36-item Short Form Health Survey questionnaire (SF-36) scores for pain were 3.6 ± 1.2, 84.1 ± 9.6, 86.3 ± 10.7, and 94.7 ± 9.3, respectively. All patients were treated with all-inside posterior arthroscopy for the debridement of the FHL tendon sheath combined with partial muscle belly resection. Post-operative follow-up and observation of the patients\' pain and ankle movement were evaluated using VAS, AOFAS, KAFS, and SF-36. All incisions were healed in the first stage, and no complications such as nerve, blood vessel, or tendon injuries occurred. The hospital stays were 3 to 5 days, with a mean of 3.7 ± 1.3 days. All patients were followed up for 12 to 36 months, with a mean follow-up time of 25.4 ± 8.5 months. By the last follow-up, the ankle joint and hallux movement were normal and returned to the pre-pain state for these patients. The VAS score decreased to 0.2 ± 0.1, while the AOFAS, KAFS, and SF-36 scores increased to 97.7 ± 8.5, 97.9 ± 8.2, and 118.2 ± 8.4, respectively. Advantages of all-inside posterior arthroscopic partial muscle belly resection for the treatment of FHL tendon impingement syndrome include small surgical trauma, fast functional recovery, and reliable outcomes. This procedure is therefore worthy of clinical attention and promotion.

OBJECTIVE: To investigate the effectiveness of arthroscopic talocalcaneal coalition resection in painful adults via a modified posterior approach.
METHODS: Between January 2015 and December 2017, 9 patients with painful talocalcaneal coalition accepted arthroscopic resection via the posterior malleolus high lateral observation approach combined with the lower medial operation approach. Of them, 6 were male and 3 were female, aged from 19 to 30 years (mean, 24 years). Among them, 2 cases had no definite local trauma and 7 cases had a history of sprain of foot and ankle. The disease duration ranged from 6 to 30 months, with a median of 12 months. Rozansky classification of talocalcaneal coalition for the 9 patients: 5 cases (5 feet) were type Ⅰ, 2 cases (2 feet) type Ⅱ, and 2 cases (2 feet) type Ⅲ. The patients had no sequelae of limb dysfunction and no limb joint surgery in the past. All the patients received anteroposterior and lateral X-ray films and CT scans of the ankle joint during follow-up. The visual analogue scale (VAS) score and American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hind foot score were used to evaluate the effectiveness.
RESULTS: The operation time was 60-90 minutes (mean, 76 minutes). All patients were followed up 12-24 months (mean, 18 months). All the incisions healed by first intention, without infection, skin necrosis, lower extremity deep vein thrombosis, vascular nerve and tendon injury, bone bridge recurrence, and other complications. The ankle function recovered well and the pain was relieved obviously after operation, and the patients returned to work at 3-5 months after operation, with an average of 3.9 months. At last follow-up, the VAS score was 0.7±0.5, which was significantly improved ( t=20.239, P=0.000) when compared with preoperative score (4.2±0.5); the AOFAS ankle-hind foot score was 94±4, which was significantly improved ( t=-27.424, P=0.000) when compared with preoperative score (62±2). According to AOFAS ankle-hindfoot scoring system, the results were excellent in 7 cases and good in 2 cases at last follow-up.
CONCLUSIONS: It is more intuitive, more space, and more flexibility for operation via the modified posterior malleolus high lateral observation approach combined with the lower medial operation approach in talocalcaneal coalition. It is feasible to remove talocalcaneal coalition programmatically according to the specific anatomic signs during the operation.
UNASSIGNED: 探讨采用关节镜下改良后踝入路切除治疗成人疼痛性跟距骨桥的疗效。.
UNASSIGNED: 2015 年 1 月—2017 年 12 月，采用后踝高位外侧观察入路结合低位内侧操作入路切除治疗 9 例成人疼痛性跟距骨桥。男6 例，女 3 例；年龄 19～30 岁，平均 24 岁。2 例无明确局部外伤，7 例有足踝部扭伤病史。病程 6～30 个月，中位病程 12 个月。跟距骨桥 Rozansky 分型：Ⅰ型 5 例（5 足），Ⅱ型 2 例（2 足），Ⅲ型 2 例（2 足）。患者既往无肢体功能障碍后遗症、无肢体关节手术史。术后随访复查踝关节正侧位 X 线片、踝关节 CT。比较手术前后疼痛视觉模拟评分（VAS）及美国矫形足踝协会（AOFAS）踝-后足评分。.
UNASSIGNED: 患者手术时间 60～90 min，平均 76 min。术后患者均获随访，随访时间 12～24 个月，平均 18 个月。术后切口均Ⅰ期愈合，无感染、皮肤坏死、下肢深静脉血栓形成、血管神经及肌腱损伤、骨桥复发等并发症发生。术后踝关节功能恢复良好，疼痛明显缓解；患者于术后 3～5 个月，平均 3.9 个月重返工作岗位。末次随访时 VAS 评分为（0.7±0.5）分，与术前（4.2±0.5）分比较差异有统计学意义（ t=20.239， P=0.000）；AOFAS 踝-后足评分为（94±4）分，与术前（62±2）分比较差异有统计学意义（ t=–27.424， P=0.000），末次随访时获优 7 例，良 2 例。.
UNASSIGNED: 后踝高位外侧观察入路结合低位内侧操作入路显露跟距骨桥更直观，操作空间更大，操作过程更灵活，术中根据特定解剖标志程序化切除跟距骨桥，操作具有可行性。.

The neglected Achilles tendon rupture requires surgical reconstruction for the best functional outcome. According to the current literature, there are many reconstructive options available that demonstrate acceptable functional results in most cases. These procedures require large incisions, leading to potential wound-healing complications. Therefore, these procedures may not be suitable for patients who are at high risk for wound-healing problems. A minimally invasive approach is desirable in this situation to decrease the risk of this potential complication. Endoscopic transfer of the flexor hallucis longus tendon is described in this series as an alternative to reconstruct the Achilles tendon in 2 such high-risk individuals. Both patients had a successful outcome with no wound-healing problems and regained acceptable functional status.

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.

Isolated rupture of the flexor hallucis longus tendon is an unusual injury. We present the case of a neglected flexor hallucis longus tendon closed traumatic rupture at the plantar aspect of the first phalangeal head of the great toe in a middle-age male. The injury occurred while he was dancing. Because end-to-end tendon suture was impossible, the ensuing gap was repaired using a free plantaris tendon graft. We present the operative repair benefit of the flexor hallucis longus tendon rupture to regain the function and strength of the interphalangeal joint of the hallux, avoid extension of the distal phalanx, and maintain the longitudinal arch of the foot.

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: Transfer of a flexor hallucis longus (FHL) tendon can not only reconstruct the Achilles tendon but also provide ischemic tendinous tissues with a rich blood supply to enhance wound healing. This retrospective study aims to investigate clinical outcomes in patients who underwent repair of Kuwada grade IV chronic Achilles tendon rupture with long hallucis longus tendons harvested using a minimally invasive technique.
METHODS: 35 patients who were treated for Kuwada grade IV Achilles tendon injuries from July 2006 to June 2011 were included in this retrospective study. The age ranged between 23 and 71 years. The duration from primary injury to surgery ranged from 29 days to 34 months (mean value, 137.6 days). All 35 patients had difficulties in lifting their calves. Thirty two were followed up for a mean 32.2 months (range 18-72 months), whereas three were lost to followup. Magnetic resonance imaging (MRI) showed that the tendon rupture gap ranged from 6.0 to 9.2 cm. During surgery, a 2.0 cm minor incision was made vertically in the medial plantar side of the midfoot, and a 1.5 cm minor transverse incision was made in the plantar side of the interphalangeal articulation of the great toe to harvest the FHL tendon, and the tendon was fixed to the calcaneus with suture anchors. Postoperative appearance and function were evaluated by physiotherapists based American Orthopedic Foot and Ankle Society-ankle and hindfoot score (AOFAS-AH), and Leppilahti Achilles tendon ratings.
RESULTS: Results were assessed in 32 patients. Except for one patient who suffered complications because of wound disruption 10 days after the operation, all other patients had primary wound healing, with 28 of 32 able to go up on their toes at last followup. The AOFAS-AH score was increased from preoperative (51.92 ± 7.08) points to (92.56 ± 6.71) points; Leppilahti Achilles tendon score was increased from preoperative (72.56 ± 7.43) to (92.58 ± 5.1). There were statistically significant differences. The result of the total excellent and good rate was 93.8% (30/32). MRI of Achilles tendon showed even signal without evidence of tear or cystic degeneration.
CONCLUSIONS: Reconstruction of a chronic Achilles tendon rupture with an FHL tendon harvested using a minimally invasive technique showed good outcomes.

Fracture of the posterior process of the talus with concomitant subtalar dislocation is rare; thus, the mechanism of injury, appropriate treatment, and prognosis are unclear. We report the case of a 50-year-old male with a fracture of the posterior process of the talus with concomitant subtalar dislocation that was recognized early and successfully treated operatively.