A prospective randomized study comparing retractor-endoscopic vs. open release of carpal tunnel and cubital tunnel syndromes.

OBJECTIVE: To evaluate the neurological and neurophysiological outcomes of retractor-endoscopic versus open release in carpal tunnel syndrome (rCTS and oCTS, respectively) and cubital tunnel syndrome (rCbTS and oCbTS, respectively) at 3- and 12-month follow-up. METHODS: Between 2013 and 2017, 80 patients were prospectively blindly randomized. McGowan scores were used for preoperative grading and outcomes were assessed using a modified Bishop rating system (BRS). Furthermore, incapacity to work, duration of postoperative pain, hypoesthesia, atrophy, subjective weakness, and a subjective assessment of the operative result were analyzed. The differences in the cohorts were evaluated with t-tests and ANOVAs as parametric tests and Kruskal-Wallis and Mann-Whitney U tests as nonparametric tests. RESULTS: The 80 patients underwent retractor-endoscopic or open decompression of the median or ulnar nerve. The rCTS group exhibited significant improvements in neurophysiological data (P = 0.032), shorter periods of postoperative pain (P = 0.03), and less discomfort (P = 0.005), as well as significantly better BRS results after 3 months compared with the oCTS group (P = 0.005). Between the oCbS and rCbTS groups, no significant differences were observed (P > 0.05). Regarding improvements in McGowan scores, no statistically significant differences were observed between the rCTS and oCTS groups after 3 months (P = 0.52) or 12 months (P = 0.86), nor were any observed between the rCbTS and oCbTS groups after 3 months (P = 0.88) or 12 months (P = 0.10). CONCLUSION: Significantly superior results were obtained at short-term follow-up for rCTS, whereas no superiority was found for rCbTS release. This study concluded that this endoscopic procedure is safe as well as and effective and has the potential to achieve better results in carpal tunnel syndrome compared with conventional methods.

Nerve Graft Length and Recovery of Elbow Flexion Muscle Strength in Patients With Traumatic Brachial Plexus Injuries: Case Series.

BACKGROUND: Traumatic brachial plexus injuries cause long-term maiming of patients. The major target function to restore in complex brachial plexus injury is elbow flexion. OBJECTIVE: To retrospectively analyze the correlation between the length of the nerve graft and the strength of target muscle recovery in extraplexual and intraplexual nerve transfers. METHODS: A total of 51 patients with complete or near-complete brachial plexus injuries were treated with a combination of nerve reconstruction strategies. The phrenic nerve (PN) was used as axon donor in 40 patients and the spinal accessory nerve was used in 11 patients. The recipient nerves were the anterior division of the upper trunk (AD), the musculocutaneous nerve (MC), or the biceps branches of the MC (BBs). An index comparing the strength of elbow flexion between the affected and the healthy arms was correlated with the choice of target nerve recipient and the length of nerve grafts, among other parameters. The mean follow-up was 4 yr. RESULTS: Neither the choice of MC or BB as a recipient nor the length of the nerve graft showed a strong correlation with the strength of elbow flexion. The choice of very proximal recipient nerve (AD) led to axonal misrouting in 25% of the patients in whom no graft was employed. CONCLUSION: The length of the nerve graft is not a negative factor for obtaining good muscle recovery for elbow flexion when using PN or spinal accessory nerve as axon donors in traumatic brachial plexus injuries.

Axillary Intraneural Ganglion Cysts.

Aside from affecting the stability of the glenohumeral joint, tears in the joint capsule can give rise to extraneural (paralabral) and, very rarely, intraneural ganglion cysts. This report presents the first two cases of axillary intraneural ganglion cysts in the literature with magnetic resonance imaging. Both cases were incidentally noted to have coexisting lesions (lymphadenopathy from an undifferentiated malignancy and suprascapular nerve entrapment, respectively). This report reinforces the applicability of the articular theory for intraneural ganglion cysts at a novel site.

Application of a Compact High-Definition Exoscope for Illumination and Magnification in High-Precision Surgical Procedures.

BACKGROUND: The basic necessities for surgical procedures are illumination, exposure, and magnification. These have undergone transformation in par with technology. One of the recent developments is the compact magnifying exoscope system. In this report, we describe the application of this system for surgical operations and discuss its advantages and pitfalls. METHODS: We used the ViTOM exoscope mounted on the mechanical holding arm. The following surgical procedures were conducted: lumbar and cervical spinal canal decompression (n = 5); laminotomy and removal of lumbar migrated disk herniations (n = 4); anterior cervical diskectomy and fusion (n = 1); removal of intraneural schwannomas (n = 2); removal of an acute cerebellar hemorrhage (n = 1); removal of a parafalcine atypical cerebral hematoma caused by a dural arteriovenous fistula (n = 1); and microsutures and anastomoses of a nerve (n = 1), an artery (n = 1), and veins (n = 2). RESULTS: The exoscope offered excellent, magnified, and brilliantly illuminated high-definition images of the surgical field. All surgical operations were successfully completed. The main disadvantage was the adjustment and refocusing using the mechanical holding arm. The time required for the surgical operation under the exoscope was slightly longer than the times required for a similar procedure performed using an operating microscope. CONCLUSIONS: The magnifying exoscope is an effective and nonbulky tool for surgical procedures. In visualization around the corners, the exoscope has better potential than a microscope. With technical and technologic modifications, the exoscope might become the next generation in illumination, visualization, exposure, and magnification for high-precision surgical procedures.

Self-Inflicted Hammer Blows to the Cranial Vault: An Interdisciplinary Challenge.

Depression is predicted to be the most common cause of disability in the coming decade. Self-inflicted hammer blow to the cranium is a rare phenomenon seen in patients with a history of attempted suicide. The resulting comminuted depressed skull fracture of the midline vertex is life threatening. Rapid interdisciplinary communication and intervention are essential to reduce morbidity and mortality. We present a case of self-inflicted hammer blows to the head, review the relevant literature on this topic, and discuss neurosurgical and psychiatric implications.

Tibioperoneal Short Circuiting for Stump Neuroma Pain in Amputees: Revival of an Old Technique.

BACKGROUND: Stump neuroma pain in amputees can be quite challenging. Surgical treatment may be largely subdivided into neuromodulative and non-neuromodulative methods. The latter includes neurocapsis, insertion of nerve stump into the bone marrow, centro-central short circuit (CCSC), and coverage with vascularized soft tissue flaps. CCSC was shown to be extremely effective in alleviation of pain. Reports on CCSC for the treatment of stump neuroma pain have disappeared from the literature, with a shift toward neuromodulation for the treatment of pain irrespective of etiology. METHODS: We observed 8 lower limb amputees undergoing CCSC of the sciatic nerve during a follow-up of 12 years. All had the same stump neuroma pain rendering them unable to wear their prostheses. The sciatic nerve was explored at the midthigh area, much proximal to the amputation site, and a short circuit was established between the tibial and peroneal parts of the nerve. Assessment was by means of pain quantification as per the quadruple visual analogue scale, medication intake, and ability to use prostheses. RESULTS: The median worst quadruple visual analogue scale before surgery was 8.0. After surgery it decreased to 2.5 (P = 0.00094). Medication intake was reduced from regular intake of a combination of opioids, nonsteroidal anti-inflammatory drugs, tricyclic antidepressants, and pregabalin in all patients to irregular intake of nonsteroidal anti-inflammatory drug alone in 3 of 8 patients. All patients were able to wear their limb prosthesis since surgery. CONCLUSIONS: CCSC is a simple, effective, and long-lasting method to treat painful stump neuromas in amputees. It should be strongly considered in deserving cases before resorting to neuromodulative methods.

Retractor-endoscopic nerve decompression in carpal and cubital tunnel syndromes: outcomes in a small series.

OBJECTIVE: To present midterm to long-term results obtained in carpal tunnel release, in situ decompression, and anterior transposition of the ulnar nerve using the retractor integrated endoscope. METHODS: During the period 2000-2010, 145 patients underwent endoscopic carpal tunnel releases (n = 47), endoscopic in situ decompression of the ulnar nerve (n = 55), and endoscopic anterior transposition of the ulnar nerve (n = 52). Bilateral surgery was performed in 9 patients. Independent examinations at 24 months after surgery were used for objective results (Bishop score). Subjective results were procured using a questionnaire. RESULTS: After endoscopic carpal tunnel release, 59.6% of patients showed excellent results, 21.2% showed good results, 12.8% showed fair results, and 6.4% showed poor results according to objective scoring. In 85% of patients, subjective improvement was noted after surgery; symptoms were the same as before surgery in 12.8% of patients and were worse in 2.1% of patients after surgery. After endoscopic in situ decompression, 56.4% of patients showed excellent results on objective scoring, 32.7% showed good results, 9.1% showed fair results, and 1.8% showed poor results. On subjective questioning, 72.7% of patients reported improvement, 20% reported no change in symptoms, and 7.3% reported worse symptoms. After endoscopic anterior transposition of the ulnar nerve, 48.1% of patients showed excellent results on objective scoring, 26.9% showed good results, 23.1% showed fair results, and 1.9% showed poor results. Subjectively, 65.4% of patients reported improvement, 26.9% reported no change in symptoms, and 7.7% reported worse symptoms. Patients with symptom duration of <9 months before surgery showed better results than patients with symptom duration of >9 months. CONCLUSIONS: The retractor-endoscopic technique provides good long-term results after carpal tunnel release, in situ decompression, and anterior subcutaneous transposition of the ulnar nerve. Outcomes showed some correlation to the duration of preoperative symptoms.

Open vs retractor-endoscopic in situ decompression of the ulnar nerve in cubital tunnel syndrome: a retrospective cohort study.

BACKGROUND: Both open ulnar nerve decompression and retractor-endoscopic ulnar nerve decompression have been shown to yield good results. However, a comparative evaluation of the techniques is lacking. OBJECTIVE: To compare the results of open and endoscopic surgery in cubital tunnel syndrome. METHODS: One hundred fourteen patients undergoing open (n = 59) or endoscopic (n = 55) decompression of the ulnar nerve for cubital tunnel syndrome were retrospectively compared. The long- and short-term outcomes were compared with respect to the time until return to full activity and the duration of postoperative pain. Additionally, matched pairs between the 2 groups were chosen for analysis (n = 34). RESULTS: Long-term results in the open vs endoscopic groups were as follows: excellent results, 54.2% vs 56.4%; good results, 23.8% vs 32.7%; fair results, 20.3% vs 9.1%; and poor results, 1.7% vs 1.8%, respectively. For the matched pairs, the results had similar significance levels (P = .84). The times until return to full activity in the open vs the endoscopic groups were as follows: 2 to 7 days, 18.6% vs 76.4%; 7 to 14 days, 55.9% vs 10.9%; and > 14 days, 25.4% vs 12.7% (P < .001 between nonmatched and matched pairs). The durations of postoperative pain in the open vs the endoscopic groups were as follows: 1 to 3 days, 45.8% vs 67.3%; 3 to 10 days, 42.5% vs 25.4%; and > 10 days, 11.7% vs 7.3% (P =.04 for nonmatched and P = .05 for matched pairs). CONCLUSION: There are no significant differences in long-term outcomes after open and retractor-endoscopic in situ decompression of the ulnar nerve in cubital tunnel syndrome. The short-term results are significantly better in endoscopic surgery.

Complex wound-healing problems in neurosurgical patients: risk factors, grading and treatment strategy.

BACKGROUND: Wound-healing problems in the neurosurgical patient can be particularly bothersome, owing to various specific risk factors involved. These may vary from simple wound dehiscence to complex multi-layer defects with cerebrospinal fluid (CSF) leakage and contamination. The latter is quite rare in practice and requires an individually titrated reconstruction strategy. The objective is to retrospectively analyze neurosurgical patients with complex, recalcitrant wound-healing problems we had treated in our department, attempt to develop a grading system based on the risk factors specific to our specialty and adapt a surgical reconstruction algorithm. METHODS: During an 11-year period, 49 patients were identified to have had complex, recalcitrant wound-healing problems involving the cranial vault (n = 43) and the skull base (n = 6) that required an adapted surgical wound-management strategy. The etiologies of wound healing problems were aftermaths of surgical treatment of: (1) brain tumors (nine cases), (2) aneurysm clipping (ten cases), (3) trauma (27 patients), and (4) congenital malformations (three patients). Local rotational advancement flaps were performed in 18 patients and free microvascular tissue transfer was performed in 37 cases. RESULTS: Major risk factors leading to recalcitrant wound healing problems in the presented group were: prolonged angiographic interventions (20%), ongoing chemotherapy or radiotherapy (47%), prolonged cortisone application (51%), CSF leak (76%) and, above all, multiple failed attempts at wound closure (94%). Stable long-term wound healing was achieved in all patients using vascularized tissue coverage. A ternary grading system was developed based on various risk factors in the presented cohort. Accordingly, the algorithm for reconstruction in neurosurgical patients was adapted. CONCLUSIONS: Primary disease, treatment history, and distorted anatomical structures are major concerns in the management of complex wound-healing problems in neurosurgical patients. The higher the risk factors involved, the more complex is the surgical strategy. Free microvascular tissue transfer offers stable long-term results in recalcitrant cases. However, this may be indicated only in patients with a good prognosis of the underlying disease.

Outcomes of microneurovascular facial reanimation using masseteric innervation in patients with long-standing facial palsy resulting from cured brainstem lesions.

BACKGROUND: The functions of the human face are not only of esthetic significance but also extend into metaphoric nuances of psychology. The loss of function of one or both facial nerves has a remarkable impact on patients' lives. OBJECTIVE: To retrospectively analyze the functional outcomes of microneurovascular facial reanimation using masseteric innervation. METHODS: Seventeen patients with irreparable facial paralysis resulting from benign lesions involving the facial nuclei (n = 14) or Möbius syndrome (n = 3) were treated with free muscle flaps for oral commissural reanimation using ipsilateral masseteric innervation and using temporalis muscle transfer for eyelid reanimation. Results were analyzed by the absolute commissural excursion and commissural excursion index and by a patient self-evaluation score. Presence of synkinesis was documented. Follow-up ranged from 8 to 48 months (mean, 26.4 months). RESULTS: Normalization of the commissural excursion index was observed in 8 of 17 patients (47%), an improvement was seen in 7 of 17 (41%), and failure was observed in 2 of 17 (12%). The individual dynamics of absolute commissural excursion and commissural excursion index changes are presented. A natural smiling response was observed in 10 of 17 patients (59%) but not in the remaining 7 (41%). This response reflected the patient's ability to relay the natural emotion of smiling through the masseteric nerve. Patients' self-evaluation scores were a level higher than objective indices. CONCLUSIONS: Innervation of free muscle flaps with the masseteric nerve for oral commissure reanimation might play an important role in patients with lesions of the facial nuclei (as in Möbius syndrome). Synkinesis persists for long periods after surgery. However, most of the patients learned to express their emotions by overcoming this phenomenon. Despite hypercorrection or inadequate correction, patients evaluated themselves favorably.

A novel minimally occlusive microvascular anastomosis technique using a temporary intraluminal shunt: a prospective technique to minimize brain ischemia time during superficial temporal artery-to-middle cerebral artery bypass.

OBJECTIVE: To describe a new technique of suturing microvessels with persistent perfusion via a temporary intraluminal microshunt. METHODS: Experiments were conducted in Wistar rats. Abdominal aorta grafts were explanted from donor rats. A soft silicon microcatheter was introduced into the lumen of this graft. The abdominal aorta of a recipient rat was prepared for end-to-side microvascular anastomosis. Acland clamps (S&T AG, Neuhausen, Switzerland) were applied, and a linear arteriotomy was made. One end of the graft-clad microcatheter was introduced into the lumen and occluded with a fenestrated Acland clamp. At a more distal part, a similar arteriotomy was performed, and the other end of the microcatheter was introduced into the lumen and clamped with a fenestrated Acland clip. This created a temporary shunt through the graft-clad microcatheter. Then, the graft was anastomosed to the arteriotomies at both ends, over the microcatheter, in an end-to-side manner. The microcatheter was explanted from the vessel lumen through an arteriotomy in the middle of the graft. The graft was clipped short to close this arteriotomy. The mean total occlusion time before perfusion was reestablished amounted to 3.7 minutes. This experiment was repeated in 12 animals (6 with and 6 without heparin) without technical complications. As controls, conventional anastomoses were made in 2 animals. RESULTS: Suturing microvessels mandates their occlusion during the period of anastomosis. Although ischemia is well tolerated by other tissue types, the brain is quite sensitive to even short windows of ischemia. Nonocclusive anastomotic techniques have been developed recently. These are confined to vessels with luminal diameters greater than 3 mm. We have evolved a novel technique that can be used with microvessels, as pertinent to superficial temporal artery-to-middle cerebral artery bypass. CONCLUSION: We have described a new technique for performing microvascular anastomoses over a temporary intraluminal microcatheter shunt.

Brachial plexus compression caused by recurrent clavicular nonunion and space-occupying pseudoarthrosis: definitive reconstruction using free vascularized bone flap-a series of eight cases.

OBJECTIVE: In rare cases, space-occupying pseudoarthrotic clavicular nonunion causes symptomatic brachial plexus compression. The surgical treatment of clavicular pseudoarthrosis has been extensively reported in the literature. This article reports our experience of a definitive treatment strategy using free vascularized fibula flaps in cases of persistent compression of the brachial plexus by relapsing bony nonunion mass lesions. METHODS: Six men (age range, 46-59 yr) and two women (ages 48 and 52 yr) with nonunions of clavicular midshaft fractures were referred between August 2001 and March 2005 because of progressive compression of the subclavicular neurovascular bundle. All of them had displaced traumatic clavicle fractures that had been treated previously at other institutions. At least two surgical reconstructive procedures had been performed beforehand. Four patients had motor deficits owing to compressive brachial plexus lesions; all showed symptoms of combined thoracic outlet syndrome. Our surgery consisted of resection of the space-occupying clavicular pseudoarthrosis (all eight patients), external neurolysis of the brachial plexus (four patients) and reconstruction of the resulting bone defect with free vascularized fibula flap secured with plates (all eight patients). Vascularity of the bone flap was studied using three-phase bone scintigraphy. RESULTS: All patients became free of pain symptoms after surgery. Muscle strength in two of the four patients with preoperative motor deficits improved to normal within 3 months; the other two patients required 6 and 8 months, respectively. Three-phase bone scintigraphy showed adequate perfusion of the bone flaps in all patients. Postoperative bleeding at the recipient site occurred in three patients; these required revision. One patient showed an osseosubcutaneous fistula 6 months after surgery, which was treated conservatively. There was no recurrence of pseudoarthrosis or neurovascular compression at a mean follow-up period of 38.5 months. CONCLUSION: Recurrent space-occupying pseudoarthrosis of the clavicle complicated with neurovascular compression might warrant definitive reconstruction using a free vascularized bone flap.

Traumatic lesions of the brachial plexus: an analysis of outcomes in primary brachial plexus reconstruction and secondary functional arm reanimation.

OBJECTIVE: To analyze retrospectively the outcomes of primary as well as secondary functional reconstructions in 49 patients with traumatic brachial plexus lesions from a single service. Guidelines for treatment might be extracted from this analysis. METHODS: Among 152 cases of traumatic lesion of the brachial plexus presented to our clinic, 58 underwent primary brachial plexus reconstructive surgery. On exploration, all patients showed stretching and scarring of plexus elements; root avulsions were found in 28 patients (48%). Outcome evaluation was carried out in 49 of these patients with a follow-up period of 1 year or longer (mean follow-up, 27.9 mo; range, 12-72 mo). A total of 43 secondary reconstructive procedures to improve functionality of the involved arm were performed at a later stage in 25 of 58 patients. Outcomes of the secondary functional restorative procedures were evaluated (mean follow-up, 11.5 mo; range, 3-60 mo in 43 procedures). RESULTS: Patients with neurolysis as a stand-alone procedure (11 patients) showed an outcome grade of 4 or 5. The average outcome of the 19 patients with C5, C6, and C7 grafting was Grade 3, the same as in patients with nerve transfers to the upper plexus elements (C5-C6 root avulsions, 13 patients). Patients with multiple root avulsions (five cases) showed an overall poor outcome (Grades 0-2). Secondary functional restorative surgery was performed in 43% of the patients and helped improve individual outcomes, providing a favorable effect on the general functionality of the arm. Among the restorative operations performed, the Steindler procedure, wrist extension restoration, claw hand correction, and free functional muscle flap transfer to the arm and forearm were the most rewarding. CONCLUSION: A combination of primary brachial plexus reconstruction and carefully evaluated, selected, and planned function-restorative secondary procedures might offer favorable outcomes in patients with partial or total brachial plexus lesions.

An analysis of results after selective tendon transfers through the interosseous membrane to provide selective finger and thumb extension in chronic irreparable radial nerve lesions.

PURPOSE: We present the results of a modified tendon transfer for the restoration of wrist and finger extension in irreparable radial nerve lesions. METHODS: Restoration of wrist extension, finger extension, thumb extension, and thumb abduction was done in 29 patients (20 males and 9 females; age range: 10-58 years) with isolated, irreparable radial nerve palsy. We used a modified tendon transfer technique using the flexor digitorum superficialis (FDS) 3 (to extensor indicis proprius [EIP] and extensor pollicis longus [EPL]) and FDS 4 (to extensor digitorum communis 2-4 [EDC]) as donors for the reconstruction of selective finger and thumb extension (all patients) and pronator teres (PT) for wrist extension (25 patients). Thumb abduction was achieved by transferring the palmaris longus (PL) tendon to the abductor pollicis longus (APL) (all patients). RESULTS: Results show that near-normal wrist extension was achieved in 22 of 25 patients with extension strength of M4+. In the other 3 patients, wrist extension strength did not exceed M3 (1 patient) or M4 (2 patients). Extension of long fingers with a completely extended wrist joint was achieved in 12 of 29 patients. In the remaining 17 patients, full-range finger extension was possible only with the wrist in neutral. The advantage of the selective tendon transfer (FDS 3 to EIP and EPL and FDS 4 to EDC 2-4) resulted in selective extension of the index finger and thumb, as well as other digits, in all patients. Thumb abduction and rotation was achieved in all. CONCLUSIONS: Tendon transfers are indicated in longstanding, irreparable, isolated radial nerve lesions. Selective tendon transfer of FDS 3 to EIP and EPL and FDS 4 to EDC through the interosseous membrane results in reliable selective extension of these digits. The sacrifice of FDS 3 and 4 to reconstruct finger extension results in bowing of the donor digits. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.

Telecanthus and hypertelorism in frontoethmoidal meningoencephaloceles and the surgical correction of these conditions: Part I. An orbital anthropomorphometric evaluation of the Khmer subpopulation of Cambodia.

This is the first of the two parts of a paper concerning a novel method on the surgical treatment of orbital dysmorphisms, especially telecanthus (TC) and hypertelorism (HT). The normal orbital values of a given ethnic group is an essential factor in determining the degree of correction intended in that patient population. We did not find any data related to the normal orbital values in Khmer-Cambodians in whom we performed the corrective surgeries. Thus, the aims of this article are to evaluate the orbital morphometric data procured in Khmer-Cambodians and to analyze the contradictory definitions of TC and HT found in the literature. We measured the inner canthal distance, outer canthal distance, and interpupillary distance in 688 Khmer-Cambodians. The measured normal values are presented and compared with other Asian populations. We discovered that the Khmer-Cambodian orbital morphometry did not resemble the general conception of an Asian appearance, but rather showed a similarity to values found in Indians. Telecanthus and hypertelorism are frequent orbital dysmorphisms that, however, find conflicting definitions in the literature. By means of a short literature review, we have attempted to reorganize the multiplicity of definitions in orbital measurements, as well as clarify the confusing terminology used in TC and HT.

Telecanthus and hypertelorism in frontoethmoidal meningoencephaloceles and the surgical correction of these conditions: Part II. A novel surgical approach in the treatment of telecanthus.

Frontoethmoidal meningoencephaloceles (MEC) are frequently associated with telecanthus (TC) and seldom with hypertelorism (HT). The correction of these orbital dysmorphisms are undertaken in the same setting as the surgical treatment of MEC. During several charity missions to Phnom Penh, Cambodia, the authors developed a simple surgical technique for the correction of TC that has not been described before. The results of this technique was evaluated as follows: in 58 patients, who underwent surgical treatment of MEC, the pre and postoperative inner canthal (ICD) and outer canthal distances (OCD) were measured; the interpupillary distance (IPD) was measured in 50 patients. Forty five (78%) out of the 58 patients showed a telecanthus before surgery; 39 (87%) of these 45 showed normal values after surgery, in the rest 6 (13%) the ICD could be decreased after surgery, however the values did not reach a normal range.A HT (including TC) was found in 10 patients presenting with MEC (17%) before surgery. Five (50%) of these patients did not show a HT in post surgical follow-up. In 3 (30%) of the remaining 5 patients showing persistent HT, the ICD alone could be decreased to a normal value (no TC), whereas in 2 (20%) others a TC was unchanged. Three patients with MEC had shown normal preoperative orbital morphometry. The mean follow-up was 9 months (range: 5-16 months). The reader is further referred to our previous paper for interpreting the orbital measurement values in Khmer Cambodians as pertinent to TC or HT.

The clinico-anatomic explanation for tibial intraneural ganglion cysts arising from the superior tibiofibular joint.

OBJECTIVE: To demonstrate that tibial intraneural ganglia in the popliteal fossa are derived from the posterior portion of the superior tibiofibular joint, in a mechanism similar to that of peroneal intraneural ganglia, which have recently been shown to arise from the anterior portion of the same joint. DESIGN: Retrospective clinical study and prospective anatomic study. MATERIALS: The clinical records and MRI findings of three patients with tibial intraneural ganglion cysts were analyzed and compared with those of one patient with a tibial extraneural ganglion cyst and one volunteer. Seven cadaveric limbs were dissected to define the articular anatomy of the posterior aspect of the superior tibiofibular joint. RESULTS: The condition of the three patients with intraneural ganglia recurred because their joint connections were not identified initially. In two patients there was no cyst recurrence when the joint connection was treated at revision surgery; the third patient did not wish to undergo additional surgery. The one patient with an extraneural ganglion had the joint connection identified at initial assessment and had successful surgery addressing the cyst and the joint connection. Retrospective evaluation of the tibial intraneural ganglion cysts revealed stereotypic features, which allowed their accurate diagnosis and distinction from extraneural cases. The intraneural cysts had tubular (rather than globular) appearances. They derived from the postero-inferior portion of the superior tibiofibular joint and followed the expected course of the articular branch on the posterior surface of the popliteus muscle. The cysts then extended intra-epineurially into the parent tibial nerves, where they contained displaced nerve fascicles. The extraneural cyst extrinsically compressed the tibial nerve but did not directly involve it. All cadaveric specimens demonstrated a small single articular branch, which derived from the tibial nerve to the popliteus. The branch coursed obliquely across the posterior surface of the popliteus muscle before innervating the postero-inferior aspect of the superior tibiofibular joint. CONCLUSIONS: The clinical, MRI and anatomic features of tibial intraneural ganglion cysts are the posterior counterpart of the peroneal intraneural ganglion cysts arising from the anterior portion of the superior tibiofibular joint. These predictable features can be exploited and have implications for the pathogenesis of these intraneural cysts and treatment outcomes. These ganglion cysts are joint-related and provide further evidence to support the unifying articular theory. In each case the joint connection needs to be identified preoperatively, and the articular branches and the superior tibiofibular joint should be addressed operatively to prevent cyst recurrence.