Abstract
Background:
Dislocation of the distal peroneal tendons (PTD) is an uncommon condition that may cause pain and disability around the ankle. A surgical approach is often chosen to prevent symptomatic recurrent dislocation. The primary bone block surgery (PBBS) is one of the current surgical treatment options, but evidence on patient-reported outcomes, including satisfaction and postoperative discomfort, remains lacking. This study aims to explore the patient-reported outcomes after PBBS in the treatment of PTD.
Methods:
Our case series included 19 patients (median age 38, IQR 20) surgically treated between 2014 and 2023. Patient satisfaction level using a 5-point Likert scale was scored as primary outcome. Secondary outcomes were ankle pain using an 11-point numeric rating scale (NRS) and the Foot and Ankle Outcome Score (FAOS). Additionally, patients could indicate if they had recurrent PTD (yes/no) or experienced discomfort around the bone block or screw (yes/no).
Results:
After a median follow-up of 28 months (IQR 88), 47% of patients were very satisfied and 53% were satisfied with the result of PBBS. Median NRS pain score was 1 (IQR 2) and FAOS was high, with all domain scores in the upper quartile. Two patients developed recurrent PTD after surgery (1 after screw removal), and 68% of patients experienced discomfort around the bone block area.
Conclusion:
We found a high level of satisfaction after PBBS for PTD at short-term follow-up. However, two-thirds of patients reported hardware-related discomfort and 10% experienced recurrent dislocation. Further refinement of the bone block fixation technique seems warranted.
Leve of Evidence:
Level IV, retrospective case series.
Introduction
Dislocating peroneal tendons (PTD) is an uncommon condition usually sustained after an ankle sprain during sports activities. 4 In up to 20% of patients with lateral ankle instability, the cause is recurrent PTD. 8 Untreated, this may lead to decreased activity, chronic ankle pain, and ultimately a major impact on patients' lifestyle.4,8 Patients can experience acute PTD, usually caused by an acute tear of the peritoneal retinaculum following an ankle sprain involving dorsiflexion and eversion. Other patients have suffered from chronic PTD for years following a series of ankle sprains without a specific traumatic event. Surgery is indicated for both acute and chronic (recurrent) luxation depending on pain, instability, and impact on the patient’s quality of life. In current literature, no standard operative technique has been established. Only a few case series exist that describe treatment outcomes after different surgical techniques.2,3,5,7 These series mainly focus on ankle function and treatment complications. In our institution, a single surgeon performed a standardized bone block procedure to treat symptomatic PTD over the last decade. No studies have examined patient-reported outcomes such as satisfaction and quality of life after primary bone block surgery (PBBS). The primary aim of this case series is to report the level of patient satisfaction after this technique. Secondarily, the patient-reported physical functioning, pain, and quality of life, including postoperative complications, were evaluated.
Methods
Design
This retrospective case series with questionnaire-based follow-up was approved by the local medical ethics committee (MEC 2023-068). Patients with symptomatic PTD who underwent a distal fibula bone block procedure by a single foot and ankle surgeon (TvR) between June 2014 and March 2023 with a minimum follow-up of 6 months and 16 years and older were eligible to be included. Patients who were unable to complete the questionnaires or give informed consent were excluded.
Data Collection
Participants received a letter explaining the aim and procedures of the study by post or, if preferred, a digital version by email. Patients could indicate by filling out an informed consent form if they wanted to participate or not. Questionnaires were sent to those patients who agreed to participate. The primary outcome was the level of patient satisfaction after surgery assessed using a 5-point Likert scale (1 = very dissatisfied, 2 = unsatisfied, 3 = neutral, 4 = satisfied, 5 = very satisfied). Secondary outcomes were ankle pain measured on an 11-point numeric rating scale (NRS, 0-10) and the validated Dutch version of Foot and Ankle Outcome Score (NL FAOS) 9 (5 domains, 0-100, where higher scores represent fewer symptoms). An additional questionnaire was sent to the patients to ask about recurrent PTD after surgery (yes/no) and discomfort around the inserted screw/bone block area (yes/no). Information about postoperative complications—for example, infection, deep venous thrombosis, and nonunion—were obtained from the hospital’s charts.
Surgical technique
To perform the bone block surgical technique, a rectangular-shaped bone block (approximately 1.5 × 1 cm) was created within the distal fibula, using around two-thirds of its thickness. This block was then moved posteriorly within the created osteotomy plane until approximately half of its length extends posteriorly from the fibula and fixated using a 3.5-mm cancellous screw with a washer in the anterior half of the block. The aim is for the peroneal tendons to stay hooked behind the newly created block during dorsiflexion and eversion; this can be tested intraoperatively. For added stability, a periosteal flap was created from the bone block and sutured to the original insertion of the superior perineal retinaculum, creating a cuff around the tendons (see Figure 1). Postoperatively, a below-knee cast was applied for 6 weeks, and after 2 weeks full weightbearing was allowed with the cast.
Intraoperative image of primary bone block fixation with cancellous small fragment screw (3.5 mm) in a left ankle: (1) a rectangular shaped bone block (approximately 1.5 × 1 cm) moved posteriorly; (2) distal fibula; (3) a periosteal flap creating a cuff around the tendons; (4) arrow pointing at peroneal tendons behind the newly created block; (5) lateral malleolus.
Data Analysis
Descriptive statistics were used to present the data. Normally distributed variables were displayed with a mean and SD, not normally distributed variables as median and IQR. Categorical variables were presented with frequencies and percentages. Statistical analysis was performed using SPSS Statistics, version 25.
Results
Twenty-three eligible patients were identified. Four patients declined participation; 19 participants were enrolled after providing written informed consent. Participant demographics are presented in Table 1. The cause of PTD was an acute ankle trauma in 15 participants (79%). In most of these patients, PTD was diagnosed 3-6 months after acute ankle sprain, when pain and instability persisted despite nonoperative treatment. Four patients (21%) had a history of multiple ankle distortions with chronic instability and ankle pain without a specific traumatic event before presenting at our outpatient clinic where they were diagnosed with PTD.
Demographics of the 19 Included Patients.
At a median follow-up of 28 months (IQR 88) (mean 43.5, SD 41.7), 10 participants (53%) were satisfied, and 9 participants (47%) were very satisfied, with the result after primary bone block surgery. The median NRS pain score was 1 (IQR 2). The NL FAOS was in the highest quartile for all 5 domains (Table 2). No deep infection, deep venous thrombosis, or nonunion (defined as failure of the bone to heal after a minimal follow-up 6 months) were reported. Two patients had a superficial wound infection that was treated with antibiotics for 2 weeks. One patient had recurrent PTD after PBBS. A second patient had the cancellous screw removed 1 year after PBBS because of discomfort. This patient reported recurrent PTD starting 3 months after screw removal. Thirteen patients reported discomfort around the distal fibula surgical area, without further treatment (Table 3).
Foot and Ankle Outcome Score (NL FAOS) Scores at Postoperative Follow-up.
Abbreviations: ADL, activities of daily living; NL FAOS, Dutch version of the Foot and Ankle Outcome Score.
Postoperative Complications.
Discussion
This patient-focused study showed that at a median follow-up of 28 months, all 19 patients were satisfied or very satisfied with the outcome, despite a notable proportion reporting hardware-related discomfort. These results are reflected by the low pain scores and high scores on the FAOS questionnaire, with scores in the upper quartile in all 5 domains.
No studies are known about patient satisfaction after bone block surgery specifically. A retrospective cohort study by Al-Mohrej et al 1 analyzed patient expectations and satisfaction levels after foot and ankle surgery in general. They found that fulfilled patient expectations correlated with high satisfaction after surgery. Within their cohort, the most common expectation preoperatively was decreased pain followed by improved mobility of the foot and ankle. Our patients underwent the bone block procedure to halt peroneal tendon dislocation and stop the pain that accompanies dislocation. Within our cohort, reported pain levels were low (median NRS pain score of 1), and patients indicated only minor restrictions in mobility (FAOS domain ADL 95.4; Sports 80.3). Ninety percent remained free of recurrent dislocation after surgery, which is comparable to an earlier report by Larsen et al, 3 who operated on 35 patients using a comparable bone block method. In their cohort, 4 patients encountered recurrent PTD with functional limitations, based on clinical examination. These findings suggest that patient expectations of surgery were largely met, as reflected in the high satisfaction rates.
It has been suggested that anatomic bony variations of the lateral malleolus of the ankle may play a role in the onset of PTD. A recent cross-sectional study on PTD with the use of computed tomography scans could, however, not provide an association for retromalleolar bony morphology and PTD. 6 Soft tissue abnormalities such as traumatic retinacular tears and/or peroneal muscle belly differences may be more important in causing PTD than lateral malleolus anomalies. A low level of evidence (IV) systematic review showed that superior peroneal retinaculum repair alone or combined with deepening of the retromalleolar groove provide good outcomes, high satisfaction, and a redislocation rate less than 1.5% at long-term follow-up. 10 In this study, no results were reported for bony procedures (like PBBS), as the evidence was considered too weak.
In our retrospective series, we encountered 2 recurrent PTD (one after screw removal). With the procedure, we aimed to hook the tendons behind a bony block and create new soft tissue coverage by constructing a periosteal retinaculum. No computed tomography imaging was used to see if the construct provided enough tendon coverage. During the procedure, we evaluated whether the bone block was capable of passively securing the tendon in its intended position. It is conceivable that postoperative active motion rendered the reconstructed retinaculum insufficient in one case, whereas screw removal may have compromised the integrity of the newly formed retinaculum in another.
Two-thirds of our participants reported discomfort around the screw and/or bone block area. When analyzing other literature surrounding bone block surgery, it becomes clear that some level of postoperative discomfort around the surgical site is not uncommon. However, it is found to be of a lesser extent than what our patients reported. Deng et al 2 reported in 3 of 24 patients (13%) pain around the scar. Micheli et al 5 described a case series of 12 patients treated with a technique that inserted a bone block from the fibula distally fixed with 2 screws. In their series, 1 patient’s surgery was complicated by a fractured bone block. Two patients underwent revision surgery because of persistent pain. When comparing our outcomes to the studies mentioned above, the main difference is that we explicitly asked our participants about any possible discomfort around the surgical area by means of the questionnaire. Other studies mainly focused on return to sports and ankle function on physical examination and did not include the patient perspective as much as we did. This may be an explanation for the difference in reported discomfort.
A strength of this study is the relatively large homogeneous group of participants, considering the uncommon diagnosis and compared to other study groups. All participants were operated on through the same bone block procedure by a single foot and ankle surgeon. Further, this is the first patient-report–focused study known that analyzes satisfaction with PBBS as well as patient reported physical functioning, pain, and effects on quality of life. However, its retrospective nature obviously comes with flaws. Prospective patient-reported outcome questionnaires at fixed time points after surgery would have been preferable. Such an approach would reduce heterogeneity in follow-up duration, minimize recall bias, and allow for more consistent and comparable assessment of patient-reported outcomes, while also enabling meaningful comparisons across different surgical techniques.
Conclusion
This study shows there is a high level of satisfaction, low pain scores, and high functioning and quality of life after PBBS for PTD at a median of 28 months’ follow-up. Nevertheless, with two-thirds of patients reporting discomfort around the screw fixation area, refinement of the bone block fixation technique seems warranted. Furthermore, with 2 recurrent dislocations (rate of 10%), PBBS may be less favorable than retinacular repair alone or combined with groove deepening. Refinement of fixation techniques and high-level comparative studies are needed to define the optimal surgical approach for symptomatic PTD
Supplemental Material
sj-pdf-1-fao-10.1177_24730114251413244 – Supplemental material for Bone block surgical treatment of distal peroneal tendon dislocation: A Short Report
Supplemental material, sj-pdf-1-fao-10.1177_24730114251413244 for Bone block surgical treatment of distal peroneal tendon dislocation: A Short Report by Mareen I. Radtke, Marrigje F. Meijer, Astrid J. de Vries and Tom M. van Raaij in Foot & Ankle Orthopaedics
Footnotes
Author Note
This work was performed at Martini Hospital, Groningen, the Netherlands.
Ethical Considerations
This study was approved by the local medical ethics committee (MEC 2023-068).
Consent to Participate
All participants provided informed consent in writing prior to their participation.
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
Declaration of Conflicting Interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. Disclosure forms for all authors are available online.
Data Availability Statement
The data that support the conclusions of this article are available from the corresponding author on reasonable request.
References
Supplementary Material
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