CT can stratify patients as low risk for tibial neuropathy following a talus fracture.

OBJECTIVE: Determine the incidence of tibial neuropathy following talus fractures and CT's ability to stratify patients at risk for developing post-traumatic neuropathy. MATERIALS AND METHODS: In this IRB-approved retrospective analysis, 71 talus fractures and 8 contralateral control ankle CTs were reviewed by one observer blinded to clinical information. CT evidence suggestive of tibial neurovascular bundle injury included nerve displacement, perineural fat effacement/edema, and bone touching nerve. The association between these CT findings and clinically evident tibial neuropathy was analyzed. A semi-quantitative likelihood score was assigned based on the degree of the CT findings around the nerve. Interobserver agreement was calculated between 2 other readers. RESULTS: Twenty-five percent of patients in this cohort had clinical evidence of tibial neuropathy. There was a high specificity (0.87-0.93) and negative predictive value (0.83-0.87), a moderate accuracy (0.80-0.82), but a lower sensitivity (0.33-0.56) associated with the CT findings. Among the CT findings, nerve displacement (p < 0.0001) and bone touching nerve (p = 0.01) were associated with tibial neuropathy. A likelihood score of 2-5 was associated (p = 0.007-0.015) with tibial neuropathy. The presence of tibial neuropathy and nerve recovery were not associated with hospital length of stay, while CT findings were. There was substantial agreement between the three readers: likelihood scores 2+ (k = 0.78) and 3+ (k = 0.72). CONCLUSIONS: Tibial neuropathy occurs following talus fractures, and CT findings may help surgeons narrow down the number of patients requiring close neurological follow-up.

A Case of Posterior Tibial Nerve Injury After Arthroscopic Calcaneoplasty.

We report the first case of distal posterior tibial nerve injury after arthroscopic calcaneoplasty. A 59-year-old male had undergone right arthroscopic calcaneoplasty to treat retrocalcaneal bursitis secondary to a Haglund's deformity. The patient complained of numbness in his right foot immediately after the procedure. Two years later and after numerous assessments and investigations, a lateral plantar nerve and medial calcaneal nerve lesion was diagnosed. In the operating room, the presence of an iatrogenic lesion to the distal right lateral plantar nerve (neuroma incontinuity involving 20% of the nerve) and the medial calcaneal nerve (complete avulsion) was confirmed. The tarsal tunnel was decompressed, and both the medial and the lateral plantar nerve were neurolyzed under magnification. To the best of our knowledge, our case report is the first to describe iatrogenic posterior tibial nerve injury after arthroscopic calcaneoplasty. It is significant because this complication can hopefully be avoided in the future with careful planning and creation of arthroscopic ports and treated appropriately with early referral to a nerve specialist if the patient's symptoms do not improve within 3 months.

A Complication of Posterior Malleolar Fracture Fixation.

We present a case of tibial nerve impingement by an anteroposterior screw inserted for stabilization of a posterior malleolar fracture. This specific complication has not previously been described in published studies, although numerous reports have described various forms of peripheral nerve entrapment. We discuss the merits of fixation of these fractures using a posterolateral approach.

Combined common peroneal and tibial nerve injury after knee dislocation: one injury or two? An MRI-clinical correlation.

OBJECT Knee dislocations are often accompanied by stretch injuries to the common peroneal nerve (CPN). A small subset of these injuries also affect the tibial nerve. The mechanism of this combined pattern could be a single longitudinal stretch injury of the CPN extending to the sciatic bifurcation (and tibial division) or separate injuries of both the CPN and tibial nerve, either at the level of the tibiofemoral joint or distally at the soleal sling and fibular neck. The authors reviewed cases involving patients with knee dislocations with CPN and tibial nerve injuries to determine the localization of the combined injury and correlation between degree of MRI appearance and clinical severity of nerve injury. METHODS Three groups of cases were reviewed. Group 1 consisted of knee dislocations with clinical evidence of nerve injury (n = 28, including 19 cases of complete CPN injury); Group 2 consisted of knee dislocations without clinical evidence of nerve injury (n = 19); and Group 3 consisted of cases of minor knee trauma but without knee dislocation (n = 14). All patients had an MRI study of the knee performed within 3 months of injury. MRI appearance of tibial and common peroneal nerve injury was scored by 2 independent radiologists in 3 zones (Zone I, sciatic bifurcation; Zone II, knee joint; and Zone III, soleal sling and fibular neck) on a severity scale of 1-4. Injury signal was scored as diffuse or focal for each nerve in each of the 3 zones. A clinical score was also calculated based on Medical Research Council scores for strength in the tibial and peroneal nerve distributions, combined with electrophysiological data, when available, and correlated with the MRI injury score. RESULTS Nearly all of the nerve segments visualized in Groups 1 and 2 demonstrated some degree of injury on MRI (95%), compared with 12% of nerve segments in Group 3. MRI nerve injury scores were significantly more severe in Group 1 relative to Group 2 (2.06 vs 1.24, p < 0.001) and Group 2 relative to Group 3 (1.24 vs 0.13, p < 0.001). In both groups of patients with knee dislocations (Groups 1 and 2), the MRI nerve injury score was significantly higher for CPN than tibial nerve (2.72 vs 1.40 for Group 1, p < 0.001; 1.39 vs 1.09 for Group 2, p < 0.05). The clinical injury score had a significantly strong correlation with the MRI injury score for the CPN (r = 0.75, p < 0.001), but not for the tibial nerve (r = 0.07, p = 0.83). CONCLUSIONS MRI is highly sensitive in detecting subclinical nerve injury. In knee dislocation, clinical tibial nerve injury is always associated with simultaneous CPN injury, but tibial nerve function is never worse than peroneal nerve function. The point of maximum injury can occur in any of 3 zones.

Sustained effectiveness of percutaneous tibial nerve stimulation for overactive bladder syndrome: 2-year follow-up of positive responders.

INTRODUCTION AND HYPOTHESIS: The aim of the study was to describe effectiveness and safety of percutaneous tibial nerve stimulation (PTNS) at 2 years in women with overactive bladder (OAB) syndrome unresponsive to pharmacotherapy. METHODS: Of 30 women who had initial positive response to PTNS, 23 continued to receive maintenance treatment and were reassessed at 2 years using bladder symptom diaries and the Incontinence Impact Questionnaire (IIQ-7). They were also questioned on acceptability and any adverse effects of long-term peripheral neuromodulative treatment. RESULTS: Data from 23 women were available and 7 had been lost to follow-up. With maintenance treatment, the median nocturnal frequency at 2 years had decreased by 57 % (3.5 to 1.5 times/night), while the median IIQ-7 had reduced from 30.4 to 21.5 (both p<0.01) compared to pre-treatment baseline. Median nocturnal frequency and IIQ-7 scores at 2 years were comparable to those documented after initial response to treatment at 6 weeks, suggesting that maintenance therapy continued to suppress OAB symptoms. Daytime frequency and daily urgency incontinence episodes at 2 years were statistically similar to those documented at 6 weeks and remained lower than pre-treatment baseline (6.5 vs 11.8 and 2.0 vs 3.5, respectively, p<0.05). The women received a median of 8.42 treatments per year and the median length between treatments was 64.3 days. Apart from hypaesthesia in the toe of one responder lasting for 4 months, there were no reported side effects. CONCLUSIONS: Women receiving PTNS for intractable OAB syndrome reported significant symptom relief at 2 years. This remains a safe mode of second-line treatment with excellent durability.

An unusual case of aneurysmal tibial nerve compression detected in ED.

We present an unusual case of tibial nerve compression caused by a true tibial posterior artery aneurysm. A 61-year-old man was admitted to the emergency department due to suspected muscle rupture. He had experienced a sudden, intense right calf pain and swelling that had begun during walking. He had a 6-month-long history of symptoms suggestive to the tibial nerve dysfunction and a month-long history of neurologic finding consistent with the right tibial nerve paresis. An examination of the legs revealed a painful mass in the posterior-medial compartment of the right calf. Emergency ultrasound scanning of the right lower leg vascularization showed an expansive saccular aneurysm of the proximal segment posterior tibial artery with mural thrombus and splitting of the aneurysmal wall. An angiography confirmed the diagnosis. Under spinal anesthesia, we performed aneurysmectomy and decompressed the tibial nerve. The histologic examination was compatible with a true aneurysm of the right posterior tibial artery.

Surgical treatment of superimposed, lower extremity, peripheral nerve entrapments with diabetic and idiopathic neuropathy.

BACKGROUND: Although it is recognized that people with peripheral neuropathy have an increased prevalence of chronic nerve entrapment, controversy still exists over their management. The present report details the evaluation, surgical approach, and outcome of a large cohort of people with diabetic and with idiopathic neuropathy. METHODS: A retrospective review of 158 consecutive patients, 96 with diabetic and 62 with idiopathic neuropathy, was done to analyze the results of neurolysis of multiple sites of chronic nerve compression in the lower extremity. Of these patients, 50 had a contralateral limb decompressed for a total of 208 limbs included in the study. Outcomes included visual analog scale (VAS) for pain in the 109 patients who had pain level greater than 8.0, measurement of the cutaneous pressure threshold for sensibility, self-reported change in pain medication usage, and self-reported change in balance. RESULTS: With a minimum follow-up of 1 year, 88% of patients with preoperative numbness reported improvement in sensation (P < 0.001). Of the 84 patients with impaired balance, 81% reported improvement in balance. Of those whose VAS was greater than 8, 83% reported an improvement in VAS (P < 0.001). There was a concomitant reduction in pain medication usage. There was no difference in outcomes between patients with diabetic versus idiopathic neuropathy in response to nerve decompression. CONCLUSIONS: Neurolysis of lower extremity chronic nerve compressions in patients with neuropathy and superimposed nerve compressions is an effective method for relieving pain, restoring sensation, and improving balance.

Earthquake generated proximal tibial nerve compression treated by surgery.

PURPOSE: This article reports on nine cases of proximal tibial nerve compression by the soleal tendinous arch caused by unsuitable treatment of acute compartment syndrome (ACS). Also, we report the clinical results of neurolysis and analyse the cause of this special type of neurological compression. METHODS: There were nine extremities in nine patients included in the study. All patients were among the victims of the Wenchuan earthquake in 2008. All patients had a previous lower extremity ACS. Pain level, numbness in the sole, muscle strength of the flexor hallucis longus and Tinel's sign were evaluated pre- and post-operatively. Each proximal tibial nerve compression was subjected to neurolysis with division of the soleal tendinous arch. RESULTS: At a mean follow-up of 22 months, eight patients (87 %) with weakness of the flexor hallucis longus showed improvement in flexor strength and seven patients (78 %) exhibited improved sensory function in the sole. All patients experienced pain relief. Subjective pain was reduced from an average score of 2.7 to 0.7 based on a visual analogue scale. Physical examination for Tinel's sign revealed all patients experienced relief of radiating pain, but two patients still retained a positive Tinel's sign (mild) over the soleal tendinous arch. In summary, four patients were highly satisfied, four were satisfied and one was neither satisfied nor dissatisfied with functional recovery after neurolysis. CONCLUSIONS: Unsuitable treatment of lower extremity ACS can lead to tibial nerve compression beneath the soleal tendinous arch. Neurolysis may improve pain and sensory and motor function.

[Postoperative palsies of the common peroneal nerve and the tibial nerve associated with lateral position].

A 36-year-old woman with systemic lupus erythematous secondary to diabetes underwent right total hip arthroplasty in the left lateral position. An epidural catheter was inserted at the L1-2 interspace and placed cephalad prior to induction of general anesthesia. After the operation, she complained of numbness on the dorsum and plantar of the left foot and was unable to dorsiflex and plantarflex the ankle. The symptoms persisted after discontinuation of the epidural infusion of a local anesthetic, and they became exacerbated after the second operation in the left lateral position. Electromyography and nerve conduction study revealed palsies of the left common peroneal nerve and the tibial nerve due to local compression and also showed mononeuritis multiplex. Fortunately, the symptoms disappeared completely eight months post-operation. It should be noted that lateral positioning may be at a substantial risk of perioperative peripheral neuropathy in patients with diseases causing neural disorder.

Early results after tibialis anterior tendon transfer for severe varus in total ankle replacement.

BACKGROUND: Treatment of severe ankle arthritis with varus malalignment remains controversial. METHODS: In 14 consecutive total ankle replacements (TAR) with tibiotalar varus malalignment of above 15 (range, 16 to 41) degrees, a complete transfer of the tibialis anterior tendon together with other soft-tissue and bony realignment measures was added to the primary procedure. RESULTS: After mean followup time of 33.4 (range, 21 to 49) months, only one case showed minor tibiotalar tilt in the frontal plane. The overall clinical results were good to excellent in all but two cases with an average AOFAS-score of 86.4 (range, 70 to 98) points. However, three cases of tibial nerve neuropathy due to entrapment or overtensioning were observed; one of these cases developed clinical problems with incomplete recovery. CONCLUSION: Tibialis anterior tendon transfer can be recommended in conjunction with TAR in cases of varus malalignment with severe muscular or ligamentous imbalance with neuropathy of the tibial nerve being the main complication.

Inside-out medial meniscus suture: an analysis of the risk of injury to the popliteal neurovascular bundle.

PURPOSE: To assess the risk of damage to the popliteal neurovascular structures when inserting the needle through the posterior aspect of the knee during inside-out suture of the posterior horn of the medial meniscus. METHODS: The first stage of our study consisted of simulating a virtual meniscal suture during magnetic resonance imaging by tracing a line from 3 different points (located medially [MP], centrally [CP], and laterally [LP] to the patellar tendon) to the posterior horn of the medial meniscus. This procedure was undertaken both at rest and with valgus stress. The next phase involved the suture of the posterior horns of medial menisci taken from cadaveric specimens, the needle being inserted through 3 separate locations (again located medially [MP], centrally [CP], and laterally [LP] to the patellar tendon). Finally, the distance from each suture thread to the aforementioned neurovascular bundle was measured. RESULTS: During the magnetic resonance imaging study, the measured distances at rest were 26.4 mm for MP, 28.8 mm for CP, and 31 mm for LP, whereas those recorded with valgus stress were 21.7 mm for MP, 23.6 mm for CP, and 26 mm for LP. In the second phase of the study (cadaveric specimen suture), the distances obtained were 22.6 mm for MP, 27.6 mm for CP, and 33 mm for LP. CONCLUSIONS: Our results indicate that when the needle is inserted through the 3 points investigated into the posteromedial region of the knee (10 mm from the posterior horn of the internal meniscus) during inside-out suture, it is far enough from the popliteal neurovascular bundle for the maneuver to be performed with a reasonable safety margin. However, this margin can be increased further still if the needle is inserted into the joint through a point located laterally to the patellar tendon. CLINICAL RELEVANCE: Inside-out suture performed 10 mm from the posterior horn of the internal meniscus through the portals studied offers a sufficient margin of safety to avoid damage to the popliteal neurovascular bundle.

Comparing partial and total tibial-nerve axotomy: long-term effects on prevalence and location of evoked pain behaviors.

Monophasic (one-time) nerve injuries heal without clinically significant residua in most cases, but rare individuals are left with neuropathic pain, even after seemingly minor lesions. The effects of lesion size on risk for chronic pain persistence are not well understood, particularly as concerns the complex regional pain syndrome, which is defined in part by pain "disproportionate" to the severity of the causative lesion, and extending outside the autonomous territory of a single nerve. To better clarify the expected prevalence of pain behaviors after nerve injury, we compared the effects in rats of different-sized axotomies on the prevalence and location of evoked pain behaviors. To highlight clinical relevance, we also describe a patient with iatrogenic tibial-nerve injury causing similar chronic neuralgia. Adult male Sprague-Dawley rats were anesthetized and had either 1/3, 2/3 or their entire left tibial nerves tightly ligated at two sites just below the sciatic trifurcation and the interposed nerve was cut. Unoperated rats provided controls. Sensory function in the tibial and sural-innervated territories of both plantar hindpaws was assessed for as long as 6 months postoperatively. Soon after surgery, evoked pain behavior developed in the ipsilesional sural-innervated site in a subset of axotomized rats and recovery was variable. The relationship between lesion size and prevalence and severity of hyperalgesia varied for different pain behaviors, with pinprick hyperalgesia clearly more likely after larger axotomies. In summary, partial tibial-nerve injury in rats models human disease and suggests that expectations of proportionality between lesion size and development of neuropathic pain may need revision.

Dexamethasone Addition to Popliteal Nerve Blocks: Effects on Duration of Analgesia and Incidence of Postoperative Nerve Complication.

Background. The purpose of this prospective, double-blinded randomized control pilot study was to evaluate the effect of adjunctive dexamethasone on analgesia duration and the incidence of postoperative neuropathic complication. Peripheral nerve blocks are an effective adjunct to decrease postoperative pain in foot and ankle surgery, and any possible modalities to augment their efficacy is of clinical utility. Methods. Patients were randomly assigned to a control group (n = 25) receiving nerve blocks of bupivacaine and epinephrine or an experimental group (n = 24) with an adjunctive 8 mg dexamethasone. The patients, surgeons, and anesthesiologists were all blinded to allocation. Patients had a minimum 1 year postoperative follow-up. Results. Forty-nine patients completed the protocol. There was no statistically significant difference in analgesia duration (P = .38) or postoperative neuropathic complication incidence (P = .67) between the 2 groups. Conclusions. The addition of dexamethasone to popliteal nerve blocks does not appear to affect analgesia duration or incidence of postoperative neuropathic complications. However, our study was underpowered, and we recommend a larger scale prospective study for validation.Levels of Evidence: Level II: Prospective, randomized control pilot study.

Lateral plantar nerve neuropraxia after FHL tendoscopy: case report and anatomic evaluation.

BACKGROUND: FHL tendoscopy has been described as minimally invasive method used to create some pathologies or facilitate some surgeries. As we have encountered lateral plantar nerve neurapraxia, we investigate the cause of lateral nerve injury during Zone 2 flexor digitorum longus (FHL) tendoscopy with a cadaveric model. MATERIAL AND METHOD: Eight feet of 4 embalmed cadavers were used for this study. Posterior ankle endoscopy (Zone 1 FHL tendoscopy) was performed with posteromedial and posterolateral portals. A 4.0-mm metal rod was inserted into the Zone 2 tendon health through the posteromedial portal. The distance between the posteromedial portal and the posterior tibial nerve was measured with the ankle in neutral position. Then, the shortest distance between the posterior tibial nerve and the rod was measured with the ankle in three positions: 20 degrees plan-tarflexion, neutral, and the 20 degrees dorsiflexion. RESULT: The average distance between the posterior tibial nerve and the posteromedial portal was 9.3 mm. The average shortest distance between the posterior tibial nerve and the metal rod was 5 mm with the ankle in 20 degrees dorsiflexion. CONCLUSION: Ankle dorsiflexion brings the posterior tibial nerve in contact with the arthroscope during Zone 2 tendoscopy. CLINICAL RELEVANCE: In order to avoid potential nerve injury during Zone 2 FHL tendoscopy, ankle dorsiflexion should be avoided.

Common peroneal and posterior tibial ischemic nerve damage, a rare cause.

A 56-year old gentleman presented to our orthopaedic foot and ankle clinic, with unusual symptoms in his left foot. He described a tight sensation over his toes, "like sandpaper under his skin". The pain had started post operatively following a bilateral aorto-femoral bypass. He was subsequently investigated and found to have an ischemic lesion Identified in his common peroneal and posterior tibial nerve with associated muscle atrophy on EMG. This represents a previously unreported complication of aorto-femoral bypass surgery.

[A case of tibial nerve palsy due to intraneural ganglion cysts].

A 39-year-old man presented with an 8-month history of pain and paresthesia of the right foot sole and difficulty in the right toe dorsiflexion. A neurological examination revealed weakness in performing both the ankle and right foot toe dorsiflexion, reduced right planta pedis sensation, and absent right Achilles tendon reflex. Tinel's sign was present on the right popliteal fossa and medial part of the right ankle. MRI of the right knee showed multiple cystic lesions in his right tibial nerve. The cystic lesions extended from the popliteal fossa and were thought to be intraneural ganglion cysts. On MRI performed 4 months later, most of the cystic lesions spontaneously vanished. Therefore, intraneural ganglia should be considered when atypical mononeuropathy, such as tibial nerve palsy, is present.

Combined peroneal and proximal tibial nerve palsies.

Combined compression of both the common peroneal nerve and the proximal tibial nerve at the level of the popliteal fossa is rare. Recently, an anatomic site of compression of the proximal tibial nerve at the soleal sling (originating arch for the soleus muscle) has been described in cadavers. The present report includes three patients who had a combined compression of the common peroneal nerve at the fibular neck (fibular tunnel syndrome) and compression of the proximal tibial nerve at the soleal sling (soleal sling syndrome). In each case, blunt trauma was the precipitating event. Neurolysis of both nerves resulted in restoration of motor and sensory function in each of these three patients. This is the first clinical report illustrating combined neurolysis of the common peroneal at the knee and the proximal tibial nerve in the soleal sling.

Traumatic neuroma of the posterior tibial nerve due to previous surgery presenting as a massive tumor in the midfoot: A case report.

A case report of traumatic neuroma, a benign non-neoplastic tumor of the posterior tibial nerve is presented. The soft tissue mass in the midfoot region was likely a sequela of previous nerve decompression surgery that the patient underwent five years previously in the same region and on the same nerve. Physical examination and history taking, along with an MRI, were important steps in reaching a definitive diagnosis of traumatic neuroma based on the findings of an interventional radiologist and histopathological evaluation of the biopsy by a pathologist. The lesion was subsequently surgically removed utilizing a multidisciplinary management approach. The patient recovered uneventfully and no symptom recurrence was noted at the 30-month follow-up. The tumor was the largest reported in the literature at the time. This case was also unique in that the patient was relieved of pronation and regained tactile sensation in the midfoot.