Flexor digitorum longus tendoscopy

Combined Arthroscopic and Endoscopic Synovectomy for Diffuse Pigmented Villonodular Synovitis (PVNS) of the Ankle

The current treatment of choice for diffuse-type pigmented villonodular synovitis (PVNS) is surgical excision. Complete synovectomy is necessary because of the local aggressiveness of the disease, with a significant recurrence rate and a minor chance of malignant transformation. The recurrence rate is even greater in those cases with extra-articular extension. Arthroscopic and endoscopic synovectomy have the advantage of avoidance of extensive soft-tissue dissection, which is associated with open synovectomy. The purpose of this Technical Note is to describe the details of combined arthroscopic and endoscopic synovectomy as treatment for diffuse PVNS of the ankle. By a combination of different arthroscopic and endoscopic approaches of the ankle region, a complete synovectomy of both intra-articular and extra-articular components of diffuse-type PVNS is feasible.

Role of arthroscopy and endoscopy in management of tuberculosis of the foot and ankle

Tuberculosis of the foot and ankle is rare but destructive. It can affect bones, joints and soft tissue and can mimic a wide range of acute and chronic infections or tumorous conditions. The primary treatment objectives for osteoarticular TB include curing the infection, limiting deformity, maintaining mobility, and reducing discomfort. Chemotherapy remains the mainstay of treatment in acute stage. Indications of surgery include biopsy and debridement in early stages to reduce the tuberculosis load and enable better penetration of anti-tuberculous drugs. Other reported indications for surgery in early stage of TB foot and ankle include resection of lesion not responding to chemotherapy and debridement of lesions close to the articular surface, as surgical debridement might halt progression and joint invasion, avoiding worsening of the prognosis. The success of arthroscopic treatment for infectious arthritis with decreased morbidity and postoperative pain makes arthroscopy an excellent alternative to open surgery. The advantages such as minor trauma, short hospitalization time and short post operative rehabilitation period as well as good cosmetic and therapeutic results should lead to a more frequent use of arthroscopy as early as possible as an adjuvant for the tuberculous joint. However, tuberculosis can involve any joints, bone and soft tissue (tendon) of the foot and ankle and surgeons should equip with various arthroscopic and endoscopic techniques in order to deal with the various situations of tuberculosis of the foot and ankle.

Arthroscopic and Endoscopic Management of Posttraumatic Hindfoot Stiffness

Ankle, hindfoot, and toe stiffness can result from hindfoot trauma. It can be due to capsular fibrosis, tendon adhesion, muscle fibrosis, or malunion. For symptomatic stiffness that is resistant to nonoperative treatment, operative treatment should be considered. It is important to tackle the sources of stiffness, and careful preoperative clinical assessment is the key for proper formulation of the surgical plan. Whenever possible, arthroscopic/endoscopic surgery is preferable to open surgery because less extensive dissection and small surgical incisions allow immediate vigorous mobilization of the foot and ankle.

Safe Zone for the Plantar Portal: A Cadaveric Study

BACKGROUND

Understanding the plantar nerve anatomy is crucial for safe endoscopic surgery of the sole. We aimed to anatomically dissect the lateral aspect and soles of cadaveric feet to investigate the safety of peroneus longus tendoscopy with a plantar lateral portal and the safe zones for plantar portals.

METHODS

We studied 36 feet of 24 cadavers (mean age, 86.5 years). A cannula for 2.7-mm scope was inserted from the plantar lateral portal to the peroneus longus tendon, and the positional relationship between the cannula and sural nerve was observed. Then, the soft tissue of the sole was dissected, and the relationships between the plantar nerve and flexor digitorum longus tendon and flexor hallucis longus tendon was observed. The plantar nerve course was digitally imaged and uploaded into Image J software to determine nerve position. We further observed the positional relationship between the cannula and plantar nerve.

RESULT

The mean minimum distance between the cannula and sural nerve was 13.8 mm, and the closest distance was 4.2 mm, allowing for the relatively safe creation of a plantar lateral portal. The use of the plantar lateral portal and evaluation of the peroneal tendon was safe with respect to the lateral plantar nerve as the nerve was in a different tissue layer of the foot. Dissection of the plantar foot demonstrated a relatively safe zone, 36.4% to 56% along a line between the medial aspect of the base of the first metatarsal bone to the proximal tip of the fifth metatarsal. This region may allow for a plantar endoscopic portal; however an anatomic variation may result in the plantar nerve being within this zone. The flexor digitorum longus tendon and peroneus longus tendon passed through the deep layer of the relatively safe zone.

CONCLUSION

Peroneus longus tendoscopy was relatively safe to perform from a plantar lateral portal. No neurovascular structure exists on the slightly medial aspect of the central region of the sole, potentially allowing for a relatively safe creation of plantar central portal. An approach from the plantar central portal to the flexor digitorum longus tendon, flexor hallucis longus tendon, and peroneus longus tendon allows for a greater range of vision and treatment options as compared with conventional approaches. The combination of the plantar central portal with portals such as the plantar lateral portal may further the development of endoscopic surgery of the sole.

CLINICAL RELEVANCE

We found the anatomic characteristics of a relatively safe zone for the plantar portal for plantar lateral portal.