Endoscopic Transfer of Flexor Hallucis Longus Tendon for Chronic Achilles Tendon Rupture: Technical Aspects and Short-Time Experiences

Surgical management of chronic Achilles tendon rupture: evidence-based guidelines

BACKGROUND

Chronic Achilles tendon ruptures (CATR) often require surgical intervention to restore function. Despite numerous treatment modalities available, the optimal management strategy remains controversial given the limited high-quality evidence available. This article aims to provide evidence-based guidelines for the surgical management of CATR through a comprehensive systematic review of the available data. The consensus reached by synthesizing the findings will assist clinicians in making informed decisions and improving patient outcomes.

METHODS

A group of 9 foot surgeons in three continents was consulted to gather their expertise on guidelines regarding the surgical management of CATR. Following the proposal of 9 clinical topics, a thorough and comprehensive search of relevant literature published since 1980 was conducted for each topic using electronic databases, including PubMed, MEDLINE, and Cochrane Library, to identify relevant studies published until 1 October 2023. All authors collaborated in drafting, discussing, and finalizing the recommendations and statements. The recommendations were then categorized into two grades: grade a (strong) and grade b (weak), following the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) concept. Additionally, feedback from 21 external specialists, who were independent from the authors, was taken into account to further refine and finalize the clinical guidelines.

RESULTS

Nine statements and guidelines were completed regarding surgical indications, surgical strategies, and postoperative rehabilitation protocol.

CONCLUSION

Based on the findings of the systematic review, this guideline provides recommendations for the surgical management of CATR. We are confident that this guideline will serve as a valuable resource for physicians when making decisions regarding the surgical treatment of patients with CATR.

Outcomes of Percutaneous Achilles Repair Compared With Endoscopic Flexor Hallucis Longus Tendon Transfer to Treat Achilles Tendon Ruptures

BACKGROUND

Both percutaneous and endoscopically assisted methods are reported to produce good results in the surgical management of acute Achilles tendon ruptures. The aim of this retrospective study was to compare between a percutaneous method and a recently described isolated endoscopically assisted flexor hallucis longus (FHL) transfer method as surgical means of management in patients with acute Achilles tendon ruptures.

METHODS

One hundred seventeen patients were included in the current study and divided into 2 groups: 59 patients who underwent percutaneous Achilles repair (PAR Group) and 58 patients who underwent isolated endoscopic FHL transfer (FHL Group) were compared. Patients were clinically evaluated using American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score, Achilles tendon Total Rupture Score (ATRS), and Achilles tendon resting angle (ATRA) measures. In addition, ankle plantarflexion power, FHL dynamometry, Tegner activity levels, and return to previous levels of activity were also documented for all patients.

RESULTS

Nine months after surgery, patients in the FHL transfer group were more likely to be able to return to normal activities (91% vs 73%, P < .01). Thirty months after surgical treatment, we found no difference in ATRS, AOFAS, ATRA, ankle plantarflexion strength, or Tegner activity scores between study groups. Overall complications were reported in 6 patients in the FHL group (10.3%) and in 8 patients in the PAR group (13.6%). No major neurovascular or skin complications were encountered.

CONCLUSION

The current study demonstrated satisfactory and comparable results and complications when comparing isolated endoscopic FHL tendon transfer or percutaneous Achilles tendon repairs in the surgical management of acute Achilles tendon ruptures.

LEVEL OF EVIDENCE

Level III, retrospective controlled trial.

Systematic review of tendon transfers in the foot and ankle using interference screw fixation: Outcomes and safety of early versus standard postoperative rehabilitation

AIMS

To compare the outcomes of early and standard rehabilitation protocols following tendon transfers in the foot and ankle using interference screw fixation (ISF).

METHODS

A systematic review was performed for relevant articles (1998 to 2020) reporting foot tendon transfer using ISF in adults. The primary outcome was early tendon failure. Secondary outcomes included function and complications.

RESULTS

In total, 21 studies met the inclusion criteria, totalling 494 patients. Seven studies reported early rehabilitation protocols. The rate of early tendon failure was zero for each protocol and studies consistently reported a significant improvement in function. No differences were found comparing different rehabilitation protocols for tendon transfer for Achilles tendon pathology and foot drop.

CONCLUSION

Both early and standard rehabilitation protocols are associated with high patient satisfaction and low complication rates, but currently there is a lack of evidence to support early loaded activities or motion.

LEVEL OF EVIDENCE

IV Systematic review including case series.

Biomechanical Analysis of Single Interference Screw vs Interference Screw With Cortical Button for Flexor Hallucis Longus Transfer

Background:

Flexor hallucis longus tendon transfer (FHL) with a cortical button tension slide is an innovative addition that has not been measured against traditional methods.

Methods:

12 pairs (n=24) of fresh-frozen cadaveric tibia-to-toe samples were used and randomized to receive one of the operative FHL techniques. Specimens underwent bone density analysis. Biomechanical loading was applied between 20 and 60 N at 1 Hz for 100 cycles. Post–cyclic load to failure occurred at 1.25 mm/s. Cyclic displacement, structural stiffness, and ultimate load were derived from load-displacement curves. Student t tests evaluated significant effects between both FHL techniques. Linear regression analysis assessed interactions between bone density and strength of FHL technique.

Results:

Average tendon diameter was 5.44±0.46 mm. Average bone density was 1.06±0.08 g/cm². Addition of a cortical button to FHL transfer did not significantly affect cyclic displacement (0.78±0.52 mm vs 0.87±0.80 mm) or structural stiffness (162.11±43.34 N/mm vs 167.57±49.19 N/mm). Cortical button addition to FHL transfer resulted in significantly increased ultimate load (343.72±68.93 N) compared with interference screw alone (255.62±77.17 N) (P = .0002). Linear regression analyses did not reveal any significant interactions between bone density and FHL tendon transfer technique.

Conclusion:

Enhanced strength can be achieved with FHL tendon transfer to calcaneus using an interference screw and cortical button tension slide technique as compared to an interference screw alone. Cortical buttons in the setting of FHL tendon transfer to the calcaneus offers an additional level of support.

Clinical Relevance:

Operative cases presenting with poor bone quality due to osteoporosis or osteopenia could benefit from cortical button fixation during FHL transfer. Clinical studies are needed to determine if the increased construct stability conferred from the additional use of a flip button results in fewer FHL transfer failures or better clinical outcomes.

Level of Evidence:

Level V, Controlled Laboratory Study.

Endoscopically Assisted, Minimally Invasive Reconstruction for Chronic Achilles Tendon Rupture With a Double-Bundle Flexor Hallucis Longus

Background:

High morbidity has been reported regarding Achilles tendon (AT) injuries, and the upward trend has accelerated since the mid-1990s. A chronic Achilles tendon rupture usually results from a neglected or misdiagnosed acute rupture, and about one-fifth of acute AT ruptures are missed and lead to chronic AT rupture. Although many techniques have been described, there is no gold standard in the treatment of chronic AT ruptures.

Hypothesis:

Endoscopically assisted, minimally invasive reconstruction for chronic AT rupture using a double-bundle flexor hallucis longus (FHL) tendon would result in improvement of the overall function, with a low rate of wound complications.

Study Design:

Case series; Level of evidence, 4.

Methods:

Between May 2015 and November 2016, a total of 19 consecutive patients were enrolled and treated using endoscopically assisted, minimally invasive reconstruction for chronic AT rupture using a double-bundle FHL. The operative assessment comprised the Achilles Tendon Total Rupture Score, the American Orthopaedic Foot & Ankle Society score, the Victorian Institute of Sports Assessment–Achilles score, and a postoperative questionnaire. All postoperative complications were recorded.

Results:

The mean follow-up time for all patients was 31 months (range, 20-42 months). According to the postoperative questionnaire, the result of surgery was excellent in 8 (42%) of 19 patients, good in 10 (53%), and fair in 1 (5%). All clinical outcome scores (mean ± SD) improved significantly after surgery: Achilles Tendon Total Rupture Score, 23.3 ± 10.3 vs 98.3 ± 9.2 (postoperatively vs preoperatively); American Orthopaedic Foot & Ankle Society, 52.1 ± 12.4 vs 97.5 ± 18.9; and Victorian Institute of Sports Assessment–Achilles, 23.4 ± 11.2 vs 95.7 ± 17.1 (P < .05). No complications with regard to wound healing or infection were noted. Twelve relatively young patients returned to preinjury activity levels, such as playing basketball or badminton, and the older patients were able to meet their daily needs, such as walking up stairs and jogging.

Conclusion:

Chronic AT ruptures were successfully treated via minimally invasive reconstruction using a double-bundle FHL, which provided excellent functional improvement. It is best suited for patients with complex requirements who are at high risk for wound complications.

Flexor hallucis longus tendon transfer for chronic Achilles tendon rupture. A retrospective study

BACKGROUND

The transfer of Flexor Hallucis Longus Tendon (FHL) is an established method for the treatment of chronic Achilles tendon ruptures. An extensive examination of power, strength, endurance and complications related to this procedure is presented.

METHODS

21 patients treated with open FHL transfer for chronic Achilles tendon rupture were studied retrospectively. Medical records were reviewed. The patients were examined with a test battery for triceps surae strength, functional tests and PROMs.

RESULTS

The median maximal concentric strength was equal,1300 vs 1336W, comparing affected with unaffected side. The endurance tests showed a larger difference, 219J vs. 2398J, respectively. The median AOFAS score was 87. 11 of 21 patients sustained one or more complications; the most common were infection, disturbed wound healing, and clawing of small toes.

CONCLUSIONS

Patients achieve almost normal maximal strength after open FHL transfer, but endurance is notably lower. The complication rate was high.

Endoscopic Management of Chronic Achilles Tendon Rupture

Chronic ruptures of the Achilles tendon are often missed injuries, which is challenging for the surgeon. The complications from reconstruction are a considerable concern. Primary repair may be attempted, but the missed injury often presents later than 4 weeks with gaps greater than 4 cm, necessitating more complex reconstructions using local tissues such as turn-down flaps and VY plasty, requiring large incisions in an unfavorable area of the body. We describe a step-by-step technique of endoscopic flexor hallucis longus reconstruction for chronic Achilles rupture, which decreases local complications. This article reviews the available literature for endoscopic flexor hallucis longus reconstruction.