Flexor Hallucis Longus Tenolysis and Tenosynovectomy in Dancers

Allograft Reconstruction of a Ruptured Flexor Hallucis Longus Tendon in a Professional Dancer: A Case Report

Stenosing tenosynovitis/tendinitis of the flexor hallucis longus (FHL) tendon is a relatively common occurrence in dancers. When nonoperative management fails, surgical tenolysis/tenosynovectomy has been shown to successfully reduce pain and restore function. In this study, we present the case of a professional contemporary dancer with FHL stenosing tenosynovitis/tendinitis who underwent a z-lengthening of the FHL proximal to the intact tendon sheath which resulted in a rupture of the FHL upon return to dance. He subsequently underwent a FHL reconstruction with tendon allograft. He returned to unrestricted professional dance at 11 months postoperative, which has been maintained at 4-year clinical and MRI follow-up.Level of evidence: V.

The Role of the Flexor Hallucis Longus in the Treatment of the Painful Hallux Metatarsophalangeal Joint

BACKGROUND

Pain in the hallux metatarsophalangeal joint (MTPJ) is very common, yet the underlying etiology remains unknown. Previous clinical research and biomechanical research has implicated stenosing flexor hallucis longus (FHL) tendonitis as a possible cause. The hypothesis of this study was that treatment solely focusing on alleviating restricted FHL excursion would be beneficial in patients with hallux MTPJ pain.

METHODS

This is a retrospective study of those treated in the Foot & Ankle Division between January 2009, and December 2018, who were diagnosed with FHL tendonitis with associated pain in the hallux MTPJ. Demographics, comorbidities, examination findings, imaging results, pain scores, treatment instituted, and outcome was obtained from the electronic medical record. The primary outcome was the improvement in the pain score (visual analog scale [VAS]). The surgical patients were included if their procedure was solely related to the FHL (posteromedial ankle release ± os trigonum resection). The decision to have surgery was analyzed by univariate and multivariable statistics using demographics, comorbidities, and clinical findings as potential factors (P < .05).

RESULTS

In 75% (59 of 79 feet), nonoperative treatment of FHL stenosis resulted in a decrease in pain scores that the patients felt was satisfactory. The operative group that had an FHL release showed decreased pain in 90% (18 of 20 feet). Multivariable analysis identified the need for immobilization (OR 9.8, 95% CI 1.8-55.2, P = .009), participating in athletics (OR 8.7, 95% CI 1.8-42.2, P = .007), and higher initial VAS (OR 1.7, 95% CI 1.3-2.3, P < .001) as being associated with the decision for surgery.

CONCLUSION

Previous biomechanical studies have suggested that stenosing FHL synovitis can cause increased intraarticular loading in the hallux MTPJ. The current clinical study supports this hypothesis, demonstrating that treatment focused on relieving restricted FHL excursion can ameliorate pain in the hallux MTPJ in select cases.

Injury of flexor halluics longus tendon in amateur marathon runners results in abnormal plantar pressure distribution: observational study

OBJECTIVE

To analyze the changes of plantar pressure in amateur marathon runners with flexor halluics longus (FHL) tendon injury using the Medtrack-Gait plantar pressure measurement system, and to explore whether the plantar pressure data can be used as an index for the diagnosis of injury.

METHODS

A total of 39 healthy amateur marathon runners without any ankle joint symptoms were recruited. Dynamic and static plantar pressure data were measured using the pressure plate of Medtrack-Gait. According to MRI imaging findings, whether the FHL tendon was injured or not was judged, and the dynamic and static data were divided into the injury group and control group. The data with statistically significant differences between the two groups were used to make the receiver operating characteristic (ROC) curve.

RESULT

The maximum contact area (PA) of the first metatarsal(M1) region, the maximum load-bearing peak value (PW) and the time pressure integral (PMPTI) of the second metatarsal(M2) region in the injury group were lower than those in the control group, respectively (P < 0.05). The maximum contact area (PA) of the fifth metatarsal(M5) region was higher than that in the control group (P < 0.05). The area under curve (AUC) value of the ROC curve of the PA of M1 region, the PW and PMPTI of M2 region were statistically (P < 0.05).

CONCLUSION

FHL tendon injury resulted in decreased PA in M1, decreased PW and PMPTI in M2, and increased PA in the M5 region, suggesting that FHL tendon injury resulted in a force shift from the medial to the lateral side of the foot. The PA of M1, PW and PMPTI of M2 have certain diagnostic value for early FHL injury in amateur marathon runners.

Flexor Hallucis Longus decompression under ultrasound guidance: A cadaver study

INTRODUCTION

The Flexor Hallucis Longus (FHL) is a muscle that can be subject to multiple impingements caused by exaggerated plantar flexion in athletes. The most common impingement is due to inflammation of the tendon at the retrotalar pulley. The constraints exerted on the FHL are responsible for a pathology called functional Hallux Limitus. Surgical treatment consists of tenolysis of the FHL arthroscopically or via open surgery, by opening the pulley. The objective of this study was to evaluate the risk of lesions of the neurovascular pedicle and the posterior tibial tendon after tenolysis of the Flexor Hallucis Longus under ultrasound guidance.

HYPOTHESIS

The hypothesis of this study is that tenolysis of the Flexor Hallucis Longus could proceed under ultrasound guidance without associated tendon lesions or neurovascular lesions.

MATERIAL AND METHODS

Thirteen cadaveric specimens were studied, resulting in an analysis of 26 feet. Following identification of the Flexor Hallucis Longus, tenolysis with a 19-gauge needle under ultrasound guidance was performed by an orthopedic specialist after hydrodissection to push back the posterior tibial pedicle. The dissection of the cadavers made it possible to verify the positioning of the posterior tibial pedicle, the FHL tendon and the opening of the retrotalar pulley.

RESULTS

Five cadaveric subjects, 10 cases, underwent a complete opening of the retrotalar pulley under ultrasound guidance. In 16 cases, the opening was partial, with a section of the pulley of 65.87±18%. The cases of partial openings showed no neurovascular or tendinous lesions. The 10 cases of complete opening resulted in 5 lesions of the tibial nerve, 4 vascular lesions: 1 venous and 3 arterial, and 6 lesions of the FHL tendon.

CONCLUSION

Tenolysis of the Flexor Hallucis Longus under ultrasound guidance at the level of its retrotalar pulley was systematically associated with neurovascular lesions in the event of complete release of the pulley by the method studied, unlike a partial release where no lesion was found.

LEVEL OF EVIDENCE

III; case-control study.