Excision of proximal fibular aggressive and malignant tumors: a new classification for surgical guidance

Based on a large multicenter experience and a review of the literature, the authors propose a unifying theory to explain an articular origin of peroneal intraneural ganglia. They believe that this unifying theory explains certain intriguing, but poorly understood findings in the literature, including the proximity of the cyst to the joint, the unusual preferential deep peroneal nerve (DPN) deficit, the absence of a pure superficial peroneal nerve (SPN) involvement, the finding of a pedicle in 40% of cases, and the high (10-20%) recurrence rate. The authors believe that peroneal intraneural lesions are derived from the superior tibiofibular joint and communicate from it via a one-way valve. Given access to the articular branch, the cyst typically dissects proximally by the path of least resistance within the epineurium and up the DPN and the DPN component of the common peroneal nerve (CPN) before compressing nearby SPN fascicles. The authors present objective evidence based on anatomical, clinical, imaging, operative, and histological data that support this unifying theory. The predictable clinical presentation, electrical studies, imaging characteristics, operative observations, and histological findings regarding peroneal intraneural ganglia can be understood in terms of their origin from the superior tibiofibular joint, the anatomy of the articular branch, and the internal topography of the peroneal nerve that the cyst invades. Understanding the controversial pathogenesis of these cysts will enable surgeons to perform operations based on the pathoanatomy of the articular branch of the CPN and the superior tibiofibular joint, which will ultimately improve clinical results.

Images in emergency medicine

The peroneal nerve is the most common site of intraneural ganglia. The neurological deficit associated with these cysts is often severe and the operation to eradicate them is difficult The aims of this multicenter study were to collate the authors' experience with a relatively rare lesion and to improve clinical outcomes by better understanding its controversial pathogenesis. Part I of this paper offers a description of 24 patients with peroneal intraneural ganglia who were treated by surgeons aware of the importance of the peroneal nerve's articular branch. Part II offers a description of three more patients who were seen after earlier operations in which the ganglion was excised, but the articular branch was not identified (all reportedly gross-total resections). Twenty-six of the 27 patients presented with clinical electrophysiological, and imaging evidence of a common peroneal nerve (CPN) lesion, predominantly affecting the deep peroneal nerve (DPN) division, and one patient presented with a painful mass of the CPN that was not accompanied by a neurological deficit. In all 24 patients in Part I there was magnetic resonance (MR) imaging evidence of a connection between the cyst and the superior tibiofibular joint, including one patient in whom high-resolution (3-tesla) MR neurography demonstrated the pathological articular branch itself. At the operation, the communication proved to extend through the articular branch of the CPN in all cases. The operation consisted of drainage of the cyst and ligation of the articular branch. At a minimum follow-up period of 1 year, these patients experienced significant improvements in their neuropathic pain, but only mild improvements in their functional deficits. In none of the 24 patients was there evidence of an intraneural recurrence. In three patients, however, extraneural ganglia developed: two patients with symptoms subsequently underwent resection of the superior tibiofibular joint without further recurrence and one patient with no symptoms was followed clinically after the recurrence was detected incidentally on 1-year postoperative imaging. As predicted, in Part II all three patients in whom the articular branch had not been ligated experienced early intraneural recurrence; both postoperative MR images and original studies, which were retrospectively examined, demonstrated a connection with the superior tibiofibular joint. The clinical presentation, electrical studies, imaging characteristics, and operative observations regarding peroneal intraneural ganglia are predictable. Treatment must address the underlying pathoanatomy and should include decompression of the cyst and ligation of the articular branch of the nerve. To avoid extraneural recurrence, resection of the superior tibiofibular joint may also be necessary, but indications for this additional procedure need to be defined. These recommendations are based on the authors' belief that intraneural peroneal ganglia arise from the superior tibiofibular joint and are connected to it by the articular branch.

Treatment of proximal fibular tumors with en bloc resection

The proximal tibiofibular joint (PTFJ) is a rather unknown articulation. There is little understanding of its anatomy, physiology, and functional role. The objectives of this research are to describe the normal kinematics of the PTFJ and its relation to the ankle and knee movements. Fourteen knees of seven adult fresh frozen whole body cadavers were studied. The proximal tibiofibular joint and ligaments were identified, after which we sequentially sectioned the anterior proximal tibiofibular ligament (APTFL), the posterior proximal tibiofibular ligament (PPTFL), and the interosseous syndesmotic membrane. Models with intact and sectioned ligaments were compared, while the unloaded lower limb was manually mobilized in a pre-defined sequence of combined movements of knee, ankle, and proximal tibiofibular joints. The PTFJ spatial displacement was measured by analyzing the length of a distance vector between two 3D coordinate systems settled over the tibia and fibula. On the unaltered PTFJ, direct grasping of the head of the fibula with the hip in 45° of flexion and the knee in 90° of flexion was found to produce an average displacement of 7mm. Knee movements caused the greatest spatial displacements, almost ten times the ones produced by ankle flexion/extension. Flexion/extension of the knee caused 1.8 times more displacement than single rotations with the knee flexed to 90°. It was found that the APTFL was an important stabilizer of the PTFJ when this joint is tensioned accommodating the movements of ankle extension and foot eversion. The APTFL was not a significant stabilizer of the PTFJ during direct manipulation of the fibular head when imprinting a manual force with posterior direction. The PPTFL was an important accommodator of ankle flexion, foot inversion and knee flexion. The interosseous syndesmotic membrane also proved to be a significant PTFJ stabilizer in rotational movements of the ankle and knee. This is the first cadaver study to illustrate the PTFJ normal spatial displacement, thereby contributing to a deeper insight of this joint. The contribution of each ligament for PTFJ stability was described and, based on these findings; a new mechanism of injury was suggested. Surgeons can translate the results of this study into the clinical practice.

The incidence of proximal tibiofibular joint instability in the setting of the multiligament-injured knee has not been previously reported. The integrity of the proximal tibiofibular joint is required to perform a fibular-based, lateral-sided knee reconstruction. We report (1) the frequency of proximal tibiofibular joint instability in patients presenting with multiligament knee injuries and evaluate (2) our ability to restore stability to this joint, (3) patient-reported outcome scores, and (4) complications in patients surgically treated for proximal tibiofibular joint instability at the time of treatment of multiligament knee instability. From 2005 to 2013, 124 patients (129 knees) sustaining multiligament knee injuries with Grade 3 instability to at least two ligaments were treated at our institution. We defined proximal tibiofibular joint instability as a dislocated or dislocatable proximal tibiofibular joint at the time of surgery. These patients underwent surgery to restore proximal tibiofibular joint stability and ligament reconstruction or repair and were followed with routine clinical examination, radiographs, and subjective outcome measures, including Lysholm and IKDC scores. Minimum followup was 12 months (mean, 32 months; range, 12-61 months). Twelve knees (12 patients, 9% of 129 knees) showed proximal tibiofibular joint instability. Knee stability in 10 patients was restored to Grade 1 or less in all surgically treated ligaments. No proximal tibiofibular joint instability has recurred. No patients have complained of ankle stiffness or pain. In the ten patients with subjective scores, mean Lysholm score was 75 (range, 54-95) and mean IKDC score was 58 (range, 22-78). There were four complications: one failed posterolateral corner reconstruction, one proximal tibiofibular joint screw removal secondary to pain over the screw head, one deep infection treated with serial irrigation and débridements with graft retention, and one closed manipulation secondary to arthrofibrosis and loss of ROM. In the setting of multiligament-injured knees, our series demonstrated a 9% incidence of proximal tibiofibular joint instability. The technique we describe successfully restored stability to the proximal tibiofibular joint and resulted in satisfactory patient-reported outcomes with low complication rates. Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Letter to the editor

This is a report of a 70-year-old patient with spontaneous pain of the dorsum area of the left foot. A few days later there was a sudden onset of foot drop. First, an idiopathic peroneal palsy was assessed but an MRI showed a cystic tumour near the fibular head. These findings resulted in the patient attending our clinic for surgical treatment. During the operation we found an intraneural ganglion of the deep peroneal nerve and the common peroneal nerve. There was no connection with the superior tibiofibular joint. The ganglion was therefore removed. Two months after the operation the patient reported an improvement of the pain but no improvement of movement of the foot. An intraneural ganglion of the peroneal nerve derives from the superior tibiofibular joint. Given access to the articular branch, the cyst typically spreads out proximally from the deep peroneal nerve to the common peroneal nerve and to the point of the sciatic nerve. The clinical symptoms are correlated with the extent of cyst propagation. Recommended therapy would include the ligation of the aricular branch, or synovectomy, or resection of the superior tibiofibular joint and decompression of the cyst.

Mucoid cysts compressing the common peroneal nerve have been reported. Whether these cysts are schwannoma or are synovial in nature is the subject of controversy in the medical literature. To contribute to this debate, the present study was designed to detail the anterior innervation of the proximal tibiofibular joint. We dissected 10 knees of five fresh cadavers after staining the tibiofibular joint under fluoroscopic guidance. Through a lateral approach near the fibular head, the common peroneal nerve was isolated then dissected distally to determine whether it or its branches ramified over the proximal tibiofibular joint. In all 10 legs, only one collateral branch was observed on the common peroneal nerve proximal to its terminal division. This collateral sent a branch to the proximal tibiofibular joint before penetrating the tibialis anterior muscle. The articular branch coursed in a superior and posterior direction approximately 1 cm to attain the tibiofibular joint. In no specimen did the deep or superficial peroneal nerves send a twig to the tibiofibular joint. This study confirms and clarifies prior descriptions of the innervation of the anterior aspect of the proximal tibiofibular joint. It clarifies the mechanisms of compression of the common peroneal nerve by synovial cysts that originate from the proximal tibiofibular joint and provides anatomical landmarks that should facilitate complete resection of these cysts.

PurposeCombined injuries of the posterolateral corner (PLC) and proximal tibiofibular joint (PTFJ) are uncommon but can lead to significant knee instability if not properly managed. While anatomical reconstruction techniques are well defined for isolated PLC injuries, the optimal strategy for managing associated PTFJ instability remains unclear. This review aims to evaluate surgical approaches and outcomes for combined PLC and PTFJ injuries.MethodsA systematic review was conducted in accordance with PRISMA guidelines. Studies were included if they described surgical management of PLC and PTFJ injuries. Data were extracted regarding patient characteristics, injury mechanisms, surgical techniques, fixation methods, and clinical outcomes. Due to heterogeneity in study design and outcome reporting, a narrative synthesis was performed.ResultsNine studies met inclusion criteria: one cadaveric biomechanical study, three retrospective series, and five case reports. Most injuries were due to high-energy trauma and commonly associated with multiligament knee injuries. PTFJ stabilization techniques included cortical screw fixation, K-wires, suture constructs, and ligament reconstruction. Despite variability in technique, outcomes were generally favorable when PTFJ instability was addressed in conjunction with PLC reconstruction. Functional scores were reported in only two studies. Documented complications included peroneal nerve palsy, hardware-related pain, infection, and arthrofibrosis.ConclusionPTFJ stability plays a critical role in the success of PLC reconstruction. Stabilizing the PTFJ—regardless of technique—appears essential for restoring knee stability. Given the low methodological quality and heterogeneity of current evidence, further prospective studies with standardized protocols are necessary to guide optimal management of these complex injuries.

Introduction:Proximal tibiofibular joint (PTFJ) ganglion cysts are very rare. The pathophysiology remains unclear. Lateral knee pain was present in dominant case, and some cases accompanied with common peroneal nerve symptoms. In cases of chronic trauma, it is sometimes confused with proximal tibiofibular joint instability. Thorough examination and investigations such as MRI are highly recommended. There is no consensus of management, but some studies indication that excision of the ganglion associated with low recurrences number.Method:We report a case of 28 yeara-old woman, with a chief complain of pain on the lateral side of her right knee. Pain increasing on one last year. She had a trauma on her knee in 5 years ago. She was diagnosis with Lateral Instability of her knee by a previous surgeon and refer to our clinic for second opinion. In physical exam we found, tenderness around fibula head, Lachman, McMurray, Lelli’s test was negative. Shuck test was not evident.. MRI was done and showing partial tear of anterior horn of lateral meniscus and partial tear of anterior proximal tibia fibula ligament also a fluid collection around the fibular head. We planned to repair the meniscus through arthroscopic and stabilize the Proximal tibiofibular joint with open surgery.Results:Standard arthroscopic surgery was performed. Tear anterior horn meniscus was repair using inside out technique. In open surgery we found the anterior proximal tibiofibular ligament quite stable, and also we found a ganglion cyst around the PTFJ. We decided to leave the anterior PTFJ ligament, and excise the ganglion until its sac and follow up the case forward.Conclusion:Symptoms of pain caused by ganglion cysts in PTFJ, although rarely, can be very disturbing. The history of chronic trauma obscures this case with instability condition. There for careful diagnosis is required. Excision of the ganglion into the sac is the treatment of choice because of the very low recurrence rate. The complex anatomical composition of the lateral side of the knee can cause pain to arise from various components. The presence of PTFJ ganglion cysts should not be ignored

Category: Ankle, Trauma Introduction/Purpose: Dislocation of the proximal tibiofibular joint (PTFJ) in association with ankle fracture is an infrequent injury. The mechanism involves a pronation-external rotation injury in which the energy exits through the PTFJ instead of the proximal fibula, like in a Maissoneuve fracture. Early diagnosis and treatment is of paramount importance to avoid complications such as pain, posterolateral knee instability and peroneal nerve injury due to chronic traction by the dislocated fibular head. In addition, an anatomical reduction of the PTFJ is mandatory to restore the fibular length in order to obtain anatomic reduction at the ankle. The objective is to report 3 cases with PTFJ dislocation in association with ankle fracture and to provide a treatment guide based on the management of these patients. Methods: Three cases of PTFJ dislocation in association with ankle fracture, surgically treated in our institution between 2009 and 2016, were retrospectively analyzed. For each case, clinical history at admission, pre and post operative radiographs and computed tomography (CT) were obtained. Clinical follow up time was between 1 and 6 years. Results: Diagnosis of the PTFJ dislocation required a high degree of suspicion. All the patients had subtle radiographic abnormalities at the PTFJ, thus requiring a CT of the knee to confirm the diagnosis. The first surgical step was to perform an open reduction of the PTFJ. Common peroneal nerve was identified and retracted. Reduction was performed with a clamp and for fixation we used one cortical positioning screw from the fibula to the tibia. After the achievement of an anatomic reduction, the second step was to approach the ankle according the specific fracture pattern. Anatomical reduction was obtained in all the patients checked by ankle and knee CT. At final follow up none of the patients had knee pain, and all returned to their activities. Conclusion: The PTFJ dislocation in association with ankle fracture is an infrequent injury and should be considered as a Maissoneuve equivalent fracture in terms of mechanism and diagnosis. A high index of suspicion is needed and the diagnosis is confirmed with a knee CT. As the Essex Lopresti injury of the upper extremity, this type of lesion requires proximal and distal stabilization. Our recommended treatment, based on the good clinical results of our 3 patient, is open reduction and screw fixation of the PTFJ as the first step in order to allow anatomical reduction of the distal injury at the ankle.

Entrapment neuropathies of the fibular nerve and its branches are often underdiagnosed due to the lack of reliable diagnosis using clinical examination and electrophysiologic evaluation. Most fibular nerve compressions may be classified into 2 broad categories: (a) mechanical causes, which occur at fibrous or fibro-osseous tunnels, and (b) dynamic causes related to nerve injury during specific limb positioning. Foot drop resulting from weakness of the dorsiflexor muscles of the foot is a relatively uncommon presentation and closely related to L5 neuropathy caused by a disc herniation. However, we herein describe a rare case of usually painless foot drop triggered by a cyst at the proximal tibiofibular joint compressing the deep fibular nerve. The presence of multilevel disc diseases made the diagnosis more difficult. Foot drop is highly troubling, and health care providers need to broaden their search for the imperative and overlapping causes especially in patients with painless drop foot, and the treatment is variable and should be directed at the specific cause. The magnetic resonance imaging (MRI), including high-resolution and 3D MR neurography, allows detailed assessment of the course and anatomy of peripheral nerves, as well as accurate delineation of surrounding soft-tissue and osseous structures that may contribute to nerve entrapment. Knowledge of normal MRI anatomy of the nerves in the knee and leg is essential for the precise assessment of the presence of peripheral entrapment conditions that may produce painless or painful drop foot. In conclusion, we stress the importance of preoperative anatomic mapping of entrapment neuropathies to minimize neurological complications. Key words: Foot drop, fibular nerve, ganglion cyst, proximal tibiofibular joint

The formation and propagation of intraneural ganglion cysts (INGCs) is being elucidated by the unified articular theory. Its principles include a connection for joint fluid to egress from a synovial joint via an articular branch to a parent nerve and cyst following the path of least resistance, dependent on pressures and pressure fluxes. The occurrence of so-called extreme peroneal or tibial INGCs in the popliteal fossa extending to the sciatic nerve has been reported. One rarely described variant with a circumferential cyst within the subparaneurial compartment outside the epineurium of nerve(s) has been previously illustrated, but its mechanism and morphology have not been clarified. In this study, the authors aimed to investigate this type of cyst to challenge the principles of the unified articular theory. Four novel cases of patients with peroneal INGCs and "extreme subparaneurial cyst(s)" of the sciatic nerve and its distal branches were investigated: 3 arose from the superior tibiofibular joint (STFJ) and 1 from the knee joint. Three other cases of recognized extreme subparaneurial cyst (2 peroneal and 1 tibial from the STFJ) and 1 case of a peroneal subparaneurial cyst in the literature were reinterpreted. Data on clinical presentation, MR images, and surgical results were analyzed. In all 8 cases, subparaneurial extension was observed to different degrees along the sciatic, tibial, common peroneal, sural, and deep and superficial peroneal nerves, as was subparaneurial-to-subparaneurial communication at the sciatic nerve bifurcation (i.e., crossover). Sequential MRI performed in 7 patients showed variable dynamic changes, including extreme ascent and descent. Extraneural rupture of the subparaneurial cyst, with spread into the surrounding tissue, was present at the sciatic nerve bifurcation in 6 cases. The authors provide pathoanatomical and pathophysiological evidence supporting that extreme subparaneurial cysts follow the principles of the articular theory. They propose a distribution pattern that explains the occurrence and evolution of extreme subparaneurial cysts along the sciatic nerve and its distal branches in patients with peroneal or tibial INGCs and subepineurial cysts. Crossover in the subparaneurial compartment allows potentially extensive circumferential distribution within connected nerves. Also, dynamic factors can lead to dramatic changes in cyst size and appearance from reabsorption or extraneural rupture. In Part 2 of this study, the authors provide evidence showing that a fenestration in the epineurium allows cysts to pass from the subepineurial-to-subparaneurial, subparaneurial-to-subparaneurial, and subparaneurial-to-subepimyseal compartments.

Role of proximal tibio-fibular joint stability in anterior cruciate ligament reconstruction- A case report and review of literature