Posterior Tibial Tendoscopy: Endoscopic Synovectomy and Assessment of the Spring (Calcaneonavicular) Ligament

The Potential of Endoscopic Spring Ligament Repair in Flatfoot Reconstruction

BACKGROUND

Spring ligament fulfills 2 main important functions: one, supporting the head of the talus and stabilizing the talonavicular joint, and the other, maintaining the longitudinal arch by acting as a static support. In this preliminary report, we describe an endoscopic repair for spring ligament injuries with modified portals.

METHODS

We performed a retrospective case series study from February 2019 to January 2022. Posterior tibial tendon and/or associated bone deformities were assessed at the same surgical procedure. All patients were ≥18 years old and they had more than 6 months of follow-up. The procedure was performed in 11 patients. Mean age was 46 years (range 18-63). Ten had concomitant bony realignment surgery, and 8 had posterior tibial tendon surgery.

RESULTS

In all patients, endoscopic spring ligament repair could be technically done. The modified portals were used in all procedures as described in the surgical technique. Three patients had a superficial lesion, 1 had a rupture <5 mm, 7 had a rupture >5 mm but not a complete rupture through the entire spring ligament. Most of the patients had good clinical results from the surgery that included endoscopic spring ligament debridement and/or repair at 2 years follow up.

CONCLUSION

In this small series we found that endoscopy may be an effective technique to diagnose and treat incomplete spring ligament injuries.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Seguridad de los portales para la reparación endoscópica del ligamento calcaneonavicular: estudio cadavérico

Introducción: La lesión del ligamento calcaneonavicular ha sido descrita como una de las causas de la deformidad en el pie plano del adulto. El objetivo de este artículo es describir portales modificados para el diagnóstico y la reparación endoscópica de las lesiones del fascículo superomedial del ligamento calcaneonavicular y evaluar la seguridad de los portales utilizados. Materiales y Métodos: Se llevó a cabo un estudio cadavérico con seis preparados reproduciendo una lesión del fascículo superomedial del ligamento calcaneonavicular con una punta de corte de radiofrecuencia y la posterior reparación endoscópica. Se crearon dos portales modificados para el abordaje. Luego se procedió a la disección anatómica para evaluar la seguridad de los portales en relación con las estructuras anatómicas. El primer portal se realiza inmediatamente proximal a una línea trazada desde la punta del maléolo medial dirigida al centro del talón, el segundo portal se emplaza 0,5 cm proximal a la inserción del tendón tibial posterior en el escafoides por transiluminación. Si es necesario, se coloca un portal accesorio inmediatamente dorsal al tendón tibial posterior a mitad de camino entre los dos portales antes descritos. Resultados: En todos los casos, fue posible la reparación del ligamento con el procedimiento endoscópico. En la disección anatómica de los portales, se observó una distancia promedio a las estructuras vasculonerviosas de 11,83 mm del portal proximal y de 9,66 mm del portal distal. Conclusión: Los portales modificados son seguros y permiten la visualización directa del haz superomedial del ligamento calcaneonavicular y su reparación endoscópica.

Endoscopically Assisted Reconstruction of Posterior Tibial Tendon for Stage 2 Posterior Tibial Tendon Dysfunction

The posterior tibial tendon functions as a primary stabilizer of the medial longitudinal arch of the foot. Posterior tibial tendon dysfunction accounts for 80% of cases of adult-acquired flatfoot deformity. It is classified into 4 stages based on the function of the tibialis posterior tendon, the reducibility of the deformity, and the condition of the ankle joint. The purpose of this Technical Note is to describe the technical details of endoscopically assisted reconstruction of theposterior tibial tendon for stage 2 posterior tibial tendon dysfunction. It consists of using the medial half of the anterior tibialis tendon as a primary transfer and augmentation by the flexor digitorum longus. This construct is then protected with a subtalar arthroereisis.

Arthroscopic approach to the spring (calcaneonavicular) ligament

BACKGROUND

This research studied the safety and efficacy of a new portal to the spring ligament. This portal is located just plantar to the insertion of the posterior tibial tendon and above the fibrous septum between the posterior tibial and the flexor digitorum longus tendons.

METHODS

Twelve fresh frozen foot and ankle specimens were used. The distance between the accessory medial portal and the medial plantar nerve was measured. The relation between the medial plantar nerve and the spring ligament was studied. The depth that can be reached through the portal was also assessed.

RESULTS

The average distance between the insertion point of the 3mm diameter metal rod and the medial plantar nerve was 20(6-27)mm. The medial plantar nerve located at lateral third of the ligament in 8 specimens (67%), middle third in 2 specimens (17%) and medial third in 2 specimens (17%). The tip of rod can reach Zone A in all specimens.

CONCLUSION

This study demonstrated that arthroscopic approach and repair of the spring ligament can injure the medial plantar nerve.

CLINICAL RELEVANCE

The clinical relevance of this cadaver study is that it confirmed the feasibility of arthroscopic approach to the whole span of the spring ligament and alerted the potential risk of injury to the medial plantar nerve during arthroscopic assisted repair of the ligament.

Role of Tendoscopy in Treating Stage II Posterior Tibial Tendon Dysfunction

BACKGROUND

Stage II tibialis posterior tendon dysfunction (PTTD) resistant to conservative therapies is usually treated with invasive surgery. Posterior tibial tendoscopy is a novel technique being used in the assessment and treatment of posterior tibial pathology. The aims of this study were (1) to clarify the role of posterior tibial tendon tendoscopy in treating stage II PTTD, (2) to arthroscopically classify spring ligament lesions, and (3) to compare the arthroscopic assessment of spring ligament lesions with magnetic resonance imaging (MRI) and ultrasonographic (US) data.

METHODS

We reviewed prospectively collected data on 16 patients affected by stage II PTTD and treated by tendoscopy. We report the reoperation rate and functional outcomes evaluated by comparing pre- and postoperative visual analogic scale for pain (VAS-pain) and the Short-Form Health Survey (SF-36; with its physical [PCS] and mental [MCS] components). Postoperative satisfaction was assessed using a VAS-satisfaction scale. One patient was lost to follow-up. Spring ligament lesions were arthroscopically classified in 3 stages. Discrepancies between preoperative imaging and intraoperative findings were evaluated.

RESULTS

At a mean of 25.6 months' follow-up, VAS-pain ( P < .001), SF-36 PCS ( P = .039), and SF-36 MCS ( P < .001) significantly improved. The mean VAS-satisfaction score was 75.3/100. Patients were relieved from symptoms in 80% of cases, while 3 patients required further surgery. MRI and US were in agreement with intraoperative data in 92% and 67%, respectively, for the tendon assessment and in 78% and 42%, respectively, for the spring ligament.

CONCLUSIONS

Tendoscopy may be considered a valid therapeutic tool in the treatment of stage II PTTD resistant to conservative treatment. It provided objective and subjective encouraging results that could allow continued conservative therapy while avoiding more invasive surgery in most cases. MRI and US were proven more useful in detecting PT lesions than spring ligament tears. Further studies on PT could use this tendoscopic classification to standardize its description.

LEVEL OF EVIDENCE

Level IV, therapeutic study, case series.

Arthroscopic Repair of Superomedial Spring Ligament by Talonavicular Arthroscopy

A spring ligament tear can occur because of failure of the tibialis posterior tendon in adult-acquired flatfoot deformity or as an isolated injury with a normal tibialis posterior tendon. The superomedial spring ligament is the most common site of rupture. Compromise of this ligament is a primary causative factor of peritalar subluxation, and a functioning tibialis posterior tendon cannot prevent or correct a planovalgus foot deformity. Therefore, the spring ligament should be repaired in addition to treatment of tibialis posterior tendon abnormalities. The purpose of this technical note is to describe a minimally invasive approach for repair of the superomedial spring ligament by talonavicular arthroscopy.

Endoscopic Repair of the Superficial Deltoid Ligament and Spring Ligament

The plantar calcaneonavicular ligament, also known as the spring ligament, is an important static stabilizer of the medial longitudinal foot arch. Compromise of this ligament is a primary causative factor of peritalar subluxation, and it should be repaired in addition to treatment of tibialis posterior tendon abnormalities. Open repair of the ligament requires extensive soft-tissue dissection. The development of the high distal portal for posterior tibial tendoscopy allows repair of the ligament endoscopically. This, together with endoscopically assisted reconstruction of the tibialis posterior tendon, allows complete endoscopic treatment of stage 2 posterior tibial tendon deficiency. The major structure at risk is the medial plantar nerve. This technique is technically demanding and should be reserved for experienced foot and ankle arthroscopists.