Differential Motion and Compression Between the Plantaris and Achilles Tendons: A Contributing Factor to Midportion Achilles Tendinopathy?

Sharp pain in a normal Achilles tendon of a professional female football player was related to a plantaris tendon in a rare position: a case report

BACKGROUND

Plantaris tendinopathy and plantaris-associated Achilles tendinopathy can be responsible for chronic pain in the Achilles tendon midportion, often accompanied by medial tenderness. As conservative treatments are less successful for this patient group, proper diagnosis is important for decision making. This report presents a case with plantaris tendinopathy in a rare (superficial) location.

CASE PRESENTATION

This article describes a pain history and treatment timeline of a professional Swedish female soccer player (32 years old, Northern European ethnicity, white) who suffered from sharp pain in the Achilles tendon midportion and tenderness on the medial and superficial side for about 2 years. Conservative treatments, including eccentric exercises, were not successful and, to some extent, even caused additional irritation in that region. Ultrasound showed a wide and thick plantaris tendon located on the superficial side of the Achilles tendon midportion. The patient was surgically treated with local removal of the plantaris tendon. After surgery there was a relatively quick (4-6 weeks) rehabilitation, with immediate weight bearing, gradual increased loading, and return to running activities after 4 weeks. At follow-up at 8 weeks, the patient was running and had not experienced any further episodes of sharp pain during change of direction or sprinting.

CONCLUSIONS

The plantaris tendon should be considered as a possible source of Achilles tendon pain. This case study demonstrates that the plantaris tendon can be found in unexpected (superficial) positions and needs to be carefully visualized during clinical and imaging examinations.

Achilles Scraping and Plantaris Tendon Removal Improves Pain and Tendon Structure in Patients with Mid-Portion Achilles Tendinopathy-A 24 Month Follow-Up Case Series

Background: Studies have demonstrated that a sub-group of patients with medial Achilles pain exhibit Achilles tendinopathy with plantaris tendon involvement. This clinical condition is characterised by structural relationships and functional interference between the two tendons, resulting in compressive or shearing forces. Surgical plantaris tendon removal together with an Achilles scraping procedure has demonstrated positive short-term clinical results. The aim of this case series was to determine the long-term outcomes on pain and Achilles tendon structure. Methods: 18 consecutive patients (13 males; 5 females; mean age 39 years; mean symptom duration 28 months), of which three were elites, were included. Clinical examination, b-mode ultrasound (US) and Ultrasound Tissue Characterisation (UTC) confirmed medial Achilles tendon pain and tenderness, medial Achilles tendinopathy plus a plantaris tendon located close to the medial side of the Achilles tendon. Patients underwent US-guided local Achilles scraping and plantaris tendon removal followed by a structured rehabilitation program. Outcomes were VISA-A score for pain and function and UTC for Achilles structure. Results: 16 of 18 patients completed the 24 months follow-up. Mean VISA-A scores increased from 58.2 (±15.9) to 92.0 (±9.2) (mean difference = 33.8, 95% CI 25.2, 42.8, p < 0.01). There was an improvement in Achilles structure with mean organised echo pixels (UTC type I+II, in %) increasing from 79.9 (±11.5) to 86.4 (±10.0) (mean difference = 6.5%, 95% CI 0.80, 13.80, p =0.01), exceeding the 3.4% minimum detectable change. All 16 patients reported satisfaction with the procedure and 14 returned to pre-injury activity levels. There were no reported complications. Conclusions: Improved pain, function and tendon structure were observed 24 months after treatment with Achilles scraping and plantaris excision. The improvement in structure on the medial side of the Achilles after plantaris removal indicates that compression from the plantaris tendon might be an important presenting factor in this sub-group.

Ultrasound and surgical inspection of plantaris tendon involvement in chronic painful insertional Achilles tendinopathy: a case series

Objectives

Chronic painful insertional Achilles tendinopathy is known to be difficult to manage. The diagnosis is not always easy because multiple different tissues can be involved. The plantaris tendon has recently been described to frequently be involved in chronic painful mid-portion Achilles tendinopathy. This study aimed to evaluate possible plantaris tendon involvement in patients with chronic painful insertional Achilles tendinopathy.

Methods

Ninety-nine consecutive patients (74 males, 25 females) with a mean age of 40 years (range 24–64) who were surgically treated for insertional Achilles tendinopathy, were included. Clinical examination, ultrasound (US)+Doppler examination, and surgical findings were used to evaluate plantaris tendon involvement.

Results

In 48/99 patients, there were clinical symptoms of plantaris tendon involvement with pain and tenderness located medially at the Achilles tendon insertion. In all these cases, surgical findings showed a thick and wide plantaris tendon together with a richly vascularised fatty infiltration between the plantaris and Achilles tendon. US examination suspected plantaris involvement in 32/48 patients.

Conclusion

Plantaris tendon involvement can potentially be part of the pathology in chronic painful insertional Achilles tendinopathy and should be considered for diagnosis and treatment when there is distinct and focal medial pain and tenderness.

Level of evidence

IV case series.

Pressure changes in the Kager fat pad at the extremes of ankle motion suggest a potential role in Achilles tendinopathy

INTRODUCTION

The Kager fat pad is one of the largest soft tissue structures local to the ankle joint, yet it is poorly understood. It has been hypothesised to have a role in Achilles tendinopathy. This study aimed to investigate the pressure areas in the Kager fat pad adjacent to the Achilles tendon and to assess the anatomy and deformation of the Kager fat pad in cadavers.

METHODS

Twelve fresh frozen cadaveric ankles (mean age 44 years, range 38-51) were mounted in a customized testing rig, enabling plantar flexion and dorsiflexion of the ankle, with the Achilles tendon loaded. A needle tipped pressure sensor was inserted in two areas of the Kager fat pad under ultrasound guidance (retrocalcaneal bursa and at 3 cm proximal from Achilles insertion). Pressure readings were recorded at different flexion angles. Following testing, the specimens were dissected to expose the Kager fat pad and retrieve it for analysis. MRI images were also taken from three healthy volunteers and the Kager fat pad deformation examined.

RESULTS

Mean pressures significantly increased in all specimens at terminal ankle plantar and dorsi flexion in both regions (p < 0.05). The Kager fat pad was consistently adherent to the Achilles at its posterior aspect for a mean length of 7.7 cm (SD 0.27, 89% of KFP length). The most distal part of the Kager fat pad was the exception and it detached from the Achilles to give way to the retroalcaneal bursa for a mean length of 0.92 cm (SD 0.24, 11% of KFP length). The bursal space is partially occupied by a constant 'wedge' extension of Kager fat pad. The mean volume of the whole Kager fat pad was 10.6 ml (SD 3.37). Video and MRI demonstrated that the Kager fat pad undergoes significant deformation during plantar flexion as it is displaced superiorly by the Achilles, with the wedge being forced into the retrocalcaneal bursal space.

CONCLUSION

The Kager fat pad does not remain static during ankle range of motion, but deforms and its pressure also changes. This observation supports the theory that it acts as a shock-absorber to the Achilles tendon and pathological changes to the fat pad may be clinically important in the development of Achilles tendinopathy.

It is possible to release the plantaris tendon under ultrasound guidance: a technical description of ultrasound guided plantaris tendon release (UPTR) in the treatment of non-insertional Achilles tendinopathy

PURPOSE

Open plantaris tendon excision and ventral paratendinous stripping is a recognised treatment option in selected patients with non-insertional Achilles tendinopathy. The aim of this study was to develop a minimally invasive outpatient technique of ultrasound guided plantaris tendon release (UPTR).

METHODS

A 19 gauge needle, 15 gauge scalpel blade, hook knife (Smith and Nephew, Boston, MA, USA) and a beaver blade (Arthrex, Naples, FL, USA), were used under ultrasound guidance to identify and divide the plantaris tendon in 12 cadaveric legs. Specimens were dissected to identify whether division of the plantaris tendon had been successful. UPTR was subsequently performed on patients.

RESULTS

The 15 gauge scalpel blade, hook knife (Smith and Nephew, Boston, MA, USA) and beaver blade (Arthrex, Naples, FL, USA) were all able to cut the plantaris tendon. However, on dissection the hook knife (Smith and Nephew, Boston MA) caused less damage to surrounding structures. Subsequently, the plantaris tendon was successfully divided in three patients using UPTR technique without complication.

CONCLUSION

UPTR is a viable technique for treating plantaris related non-insertional Achilles tendinopathy.

Eccentric Exercise for Achilles Tendinopathy: A Narrative Review and Clinical Decision-Making Considerations

BACKGROUND

Achilles tendinopathy is a common health condition encountered in the orthopedic and sports medicine settings. Eccentric exercise is a common intervention in the management of pain and limited function for this patient population, although contemporary evidence suggests additional exercise methods may be effective as well.

STUDY DESIGN

Narrative review: Methods: A literature review was performed using the electronic databases Pubmed and PEDRO for articles through February 2019. Randomized clinical trials integrating eccentric exercise, with or without co-interventions, were evaluated. Outcomes related to pain and/or function were considered. A patient case is provided to highlight decision making processes related to clinical prescription of eccentrics for Achilles tendinopathy.

RESULTS

After screening titles and abstracts, seven studies were included for full review. Two articles compared eccentric exercise to a control group, four compared eccentrics to the use of modalities, while one used eccentric exercise as part of a multimodal intervention. In each case, eccentric exercise was effective in reducing pain and improving function. In comparison to other forms of exercise or additional interventions, eccentric exercise was frequently not more effective than other options.

DISCUSSION

Eccentric exercise has been associated with clinical benefit in improving pain and function for patients with Achilles tendinopathy. Despite the available evidence reporting effectiveness of eccentrics, other options may be equally useful. Appropriate load modification and exercise prescription for patients with Achilles tendinopathy requires systematic clinical reasoning and incorporation of patient values to optimize outcomes.