Posterior Opening Research Articles

Effects of Concomitant Decompression Adjacent to a Posterior Lumbar Interbody Fusion Segment on Clinical and Radiologic Outcomes: Comparative Analysis 5 Years After Surgery.

Study Design:Retrospective cohort study.Objective:To examine the effects of concomitant decompression adjacent to the posterior lumbar interbody fusion (PLIF) segment on the clinical and radiological outcomes 5 years after surgery.Methods:Forty-five consecutive patients who had undergone L3/4 decompression with L4/5 PLIF for multilevel stenosis with degenerative spondylolisthesis (DS), and were followed for 5 years, were enrolled (group D). As a control group, 45 age-, sex- and preoperative disc height at L3/4–matched patients who had undergone L4/5 PLIF alone for L4/5DS were randomly selected (group A). Disc height, vertebral slippage, range of motion, posterior opening angle, segmental lordotic angle, presence of the intradiscal vacuum phenomenon (IVP) at the L3/4 level were measured on radiographs. Japanese Orthopaedic Association (JOA) score and the requirement for additional L3/4 surgery were evaluated.Results:In terms of pre-/postoperative radiographic changes between the groups, significant differences were detected regarding disc height narrowing of ≥3 mm (group D 31%, group A 9%) and IVP (group D 33%, group A 11%). There were no significant differences in other radiological parameters. The recovery rate of the JOA score (group D 58%, group A 61%) and reoperation rate (group D 2.2%, group A 6.7%) were not significantly different between the groups.Conclusion:Concomitant decompression adjacent to the PLIF segment accelerated adjacent disc degeneration compared to PLIF alone, but it did not predispose to the development of instability 5 years after surgery. Moreover, the JOA score and reoperation rate were not significantly different between groups D and A.

Clinical presentation and outcome of fistula in ano cases

Background: Fistula-in-ano is an abnormal communication between the anal canal or rectum and the perianal skin, which causes a chronic inflammatory response. The most common cause is nearly always by a previous anorectal abscess. The chief complaint of anorectal fistula is intermittent or constant drainage or discharge. There is usually a history of previous pain, swelling and recurrent abscess that ruptured spontaneously or was surgically drained. There may be a pink or red elevation exuding pus, or it may have healed. Digital rectal examination remains the main stay of diagnosis in anorectal fistula cases.Methods: The present cross sectional observational prospective study was conducted in 50 patients who presented with their complaints to the Surgery Outpatient Department and who were admitted under the Department of Surgery, Dr. B.R.A.M. Hospital, Raipur (C.G.), India during study period was from March 2015 to September 2016. Detailed clinical history and examination of the patient was recorded. All investigations relevant to the study were done in all the patients. Appropriate surgical management were performed. Postoperative findings were noted.Results: 36% patients are in the age group of 41-50. 82% are male patients and 18% patients are female patient. 76% Patients had single opening. 74% Patients had perianal discharge while 66% patients presented with perianal pain. 40% patients had h/o perianal abscess. Most common mode of presentation was discharge. 76% patients had posterior opening while 24% patients had anterior opening. Fistulectomy and fistulotomy were performed in 39 subjects (78%) and 7 subjects (14 %) respectively.Conclusions: Anal fistula is a common disease which is devastating to the patients and imposes challenges to the surgeon. Early diagnosis and appropriate management are the key to success.

Widening of posterior glottis through rotation of the arytenoid on its axis: Report of nine cases

IntroductionBilateral vocal folds' immobility is a challenge in laryngology. Multiple procedures have been proposed to improve breathing by statically enlarging the glottal airway, what also results in loss of voice and aspiration. We proposed a technique to enlarge the posterior glottis by rotating the arytenoids on its axis, imitating the function of the posterior cricoarytenoid muscle, with the objective of evaluating the results regarding decannulation, voice quality, and bronchoaspiration. MethodsThis study is a clinical case series of patients with bilateral vocal fold paralysis who underwent an arytenoid rotation surgery at a single tertiary university care institution between 2011 and 2017. Data were prospectively collected and was complemented with information from medical charts. Patients were assessed for decannulation, dyspnea, posterior glottic opening, quality of voice, and swallowing disorders. ResultsNine patients were included in the study. Out of three patients who required tracheostomy, two were successfully decannulated. Six patients reported a significant improvement in their dyspnea, while four patients reported a worsening of their voice. The stroboscopy evidenced a posterior glottic opening of at least 7 mm in six patients. Eight patients had no aspiratory symptoms, and the acoustic analysis showed that only one patient has a normal voice. ConclusionThe arytenoid rotation on its axis by imitating the posterior cricoarytenoid muscle preserves the physiological functions of the larynx, which allows sufficient opening of the posterior glottis for breathing, and could alter in a lesser extent the anterior glottis to maintain a good quality of voice and swallowing.

Surgical Outcomes and Limitations of Decompression Surgery for Degenerative Spondylolisthesis

Study Design:A retrospective study.Objectives:To investigate surgical outcomes and limitations of decompression surgery for degenerative spondylolisthesis.Methods:One hundred patients with degenerative spondylolisthesis who underwent decompression surgery alone were included in this study. The average follow-up period was 3.7 years. Radiography and magnetic resonance imaging were used for radiological assessment. Patients with a recovery rate of >50% throughout the study period were classified as the control group (Group C), while those with a recovery rate of <50% throughout the study period were classified as the poor group (Group P). Patients that had improved symptoms, and yet later showed neurological deterioration due to foraminal stenosis at the same level were classified as the exiting nerve root radiculopathy group (Group E), while those who showed deterioration due to slip progression at the same level were classified as the traversing nerve root radiculopathy group (Group T).Results:Patient distribution in each group was 73, 12, 7, and 8 in Groups C, P, E, and T, respectively. As for preoperative radiological features, slippage and an upper migrated disc in Group P, disc wedging and an upper migrated disc in Group E, and lamina inclination and posterior opening in Group T were evident. The cutoff value of preoperative slippage with a poor outcome was 13%.Conclusions:Surgical outcomes of decompression surgery for degenerative spondylolisthesis were successful in 73% cases. Preoperative radiological features for poor outcomes were slippage of more than 13%, an upper migrated disc, disc wedging, and lamina inclination.

Substantiating accuracy of Goodsall's rule in fistula-in-ano (Bhagandar) with anatomical consideration

BACKGROUND: The exact identification of the internal opening in the surgical treatment of anorectal fistulae is of basic importance for effective management, and the same concept was existed long back which was described by Acharya Sushruta in the context of Bhagandar (Arvachina and Parachina).In the current practice, the rule of Goodsall enables identification of the internal opening whether anterior or posterior with relation to its external opening. OBJECTIVES: The objective of this study is to substantiate the accuracy of Goodsall's rule and to establish rationality of the rule with anatomical consideration MATERIALS AND METHODS: A total of 53 operated (kshara sutra ligation) cases of fistula-in-ano during 2014–2015 were retrospectively assessed for locations of the primary (Arvachina) and secondary (Parachina) openings from the case sheets. The normal distribution test was used for the data analysis. RESULTS: Totally 46 anal fistula patients followed the Goodsall's rule while 7 patients were not as per rule, and all of them were falling in anterior external opening group. CONCLUSION: Posterior external opening fistulas were as per Goodsall's rule and anterior opening >3.25 cm or far had a straight or radial fistulous tract, which are against the Goodsall's rule.

Mucosal advancement flap for fistula-in-ano: A single-institution experience

Background and Objective: Mucosal advancement flap (MAF) is a well-described definitive treatment for complex fistula-in-ano, with high healing rates ranging from 37 to 87% for cryptoglandular fistula, but with mild incontinence rates of up to 35%. There is a paucity of Australian data to support the efficacy and complication rates of MAF, nor predictive factors for success. Patients and Methods: This was a retrospective study, with ethical approval granted by St. Vincent's Hospital Melbourne (SVHM) Quality and Risk Unit. Patients who underwent MAF at SVHM and St Vincent's Private Hospital Fitzroy from 2011 to 2015 were included in the study; all data were collected from patient medical records. Results: A total of 65 patients were treated with MAF during the study period. Fistula etiology was cryptoglandular in 82%, anovaginal in 11%, and perianal Crohn's disease in 7% of patients. Overall success rates for MAF were 66% for cryptoglandular fistula, 14% for anovaginal fistula, and 40% for Crohn's fistula. Excluding anovaginal fistulae, the success rate of MAF was 74% for males and 57% for females. MAF performed for an anterior internal opening was associated with a success rate of 65% versus 56% for a posterior internal opening. Postoperative fecal incontinence rate was 6%. Five of the patients with failed MAF underwent a second sphincter-preserving procedure; none of these were successful. Conclusion: This study supports the use of MAF for the treatment of complex fistula-in-ano, with a success rate compatible with existing literature and a low incontinence rate.

Modeling the Pathophysiology of Phonotraumatic Vocal Hyperfunction With a Triangular Glottal Model of the Vocal Folds.

Our goal was to test prevailing assumptions about the underlying biomechanical and aeroacoustic mechanisms associated with phonotraumatic lesions of the vocal folds using a numerical lumped-element model of voice production. A numerical model with a triangular glottis, posterior glottal opening, and arytenoid posturing is proposed. Normal voice is altered by introducing various prephonatory configurations. Potential compensatory mechanisms (increased subglottal pressure, muscle activation, and supraglottal constriction) are adjusted to restore an acoustic target output through a control loop that mimics a simplified version of auditory feedback. The degree of incomplete glottal closure in both the membranous and posterior portions of the folds consistently leads to a reduction in sound pressure level, fundamental frequency, harmonic richness, and harmonics-to-noise ratio. The compensatory mechanisms lead to significantly increased vocal-fold collision forces, maximum flow-declination rate, and amplitude of unsteady flow, without significantly altering the acoustic output. Modeling provided potentially important insights into the pathophysiology of phonotraumatic vocal hyperfunction by demonstrating that compensatory mechanisms can counteract deterioration in the voice acoustic signal due to incomplete glottal closure, but this also leads to high vocal-fold collision forces (reflected in aerodynamic measures), which significantly increases the risk of developing phonotrauma.

Treatment of The Posterior Unstable Shoulder.

Background:It is estimated that approximately 5% of glenohumeral instabilities are posterior. There are a number of controversies regarding therapeutic approaches for these patients.Methods:We analyse the main surgery alternatives for the treatment of the posterior shoulder instability. We did a research of the publications related with posterior glenohumeral instability.Results:There are conservative and surgical treatment options. Conservative treatment has positive results in most patients, with around 65 to 80% of cases showing recurrent posterior dislocation.There are multiple surgical techniques, both open and arthroscopic, for the treatment of posterior glenohumeral instability. There are procedures that aim to repair bone defects and others that aim to repair soft tissues and capsulolabral injuries. The treatment should be planned according to each case on an individual basis according to the patient characteristics and the injury type.Surgical treatment is indicated in patients with functional limitations arising from instability and/or pain that have not improved with rehabilitation treatment.The indications for arthroscopic treatment are recurrent posterior subluxation caused by injury of the labrum or the capsulolabral complex; recurrent posterior subluxation caused by capsuloligamentous laxity or capsular redundancy; and multidirectional instability with posterior instability as a primary component. Arthroscopic assessment will help identify potential injuries associated with posterior instability such as bone lesions or defects and lesions or defects of soft tissues.The main indications for open surgery would be in cases of Hill Sachs lesions or broad reverse Bankart lesions not accessible by arthroscopy.We indicated non-anatomical techniques (McLaughlin or its modifications) for reverse Hill-Sachs lesions with impairment of the articular surface between 20% and 50%. Disimpaction of the fracture and placement of bone graft (allograft or autograft) is a suitable treatment for acute lesions that do not exceed 50% of the articular surface and with articular cartilage in good condition. Reconstruction with allograft may be useful in lesions affecting up to 50% of the humeral surface and should be considered when there is a situation of non-viable cartilage at the fracture site. For defects greater than 50% of the articular surface or in the case of dislocations over 6 months in duration where there is poor bone quality, some authors advocate substitution techniques as a treatment of choice. The main techniques for treating glenoid bone defects are posterior bone block and posterior opening osteotomy of the glenoid.Conclusions:The treatment of the posterior glenohumeral instability has to be individualized based on the patient´s injuries, medical history, clinical exam and goals. The most important complications in the treatment of posterior glenohumeral instability are recurrent instability, avascular necrosis and osteoarthritis.

Refractive Lens Exchange Combined with Primary Posterior Vitrectorhexis in Highly Myopic Patients.

Purpose. To evaluate efficacy and safety of primary vitrectorhexis for posterior capsulotomy in highly myopic patients undergoing refractive lens exchange. Methods. The study is a prospective nonrandomized interventional study. The study comprised 60 eyes of 60 myopic patients. All patients underwent refractive lens exchange (RLE) and foldable IOL implantation combined with primary posterior capsulotomy. We used a 23-gauge vitrectomy probe for the creation of the posterior capsule opening. We followed the patients for one year. Results. During surgery, the IOLs remained well centered in the capsular bag after creation of the capsulotomy. Postoperatively, we did not report any complications related to lens centration or changes in the posterior capsulotomy size. No eye required YAG laser posterior capsulotomy and no cases of retinal detachment (RD) occurred during the follow-up period. Conclusion. Primary posterior vitrectorhexis during RLE is an efficient method in preventing the occurrence of posterior capsular opacification (PCO) and the need for YAG laser posterior capsulotomy with its possible complications.

Surgical management of Pott’s spine induced kyphosis in older children or adults

Kyphosis is one a sequelae of spinal tuberculosis. Tuberculosis affects the anterior vertebral body in at least 95% of the patients, which portends the development of kyphosis of varying degrees. Patients with severe disease, contiguous vertebral body destruction, young age, and thoracic-level affliction are more prone to severe kyphosis, which can cause cosmetic problems, costopelvic impingement pain, pulmonary dysfunction, and neurological deficit. Surgical correction is required in both active and healed stages in patients with severe kyphosis. In patients with active disease, surgical correction of kyphosis is less extensive and is based on principles of debridement, stabilization, and anterior reconstruction so that the spine heals in appropriate sagittal alignment. Different surgical techniques, including direct anterior corpectomy and stabilization, an all-posterior approach for posterior stabilization, and anterior decompression and reconstruction, and combined anterior and posterior reconstruction performed through two separate approaches, have been described. In the healed stages, patients can have severe kyphosis with or without neurological deficit. Corrective osteotomy (transpedicular decancellation osteotomy, pedicle subtraction osteotomy, posterior vertebral column resection, closing or opening wedge osteotomy, or rarely combined anterior-posterior technique) is performed to correct the deformity. Surgical correction in healed stages is an extensive and complex undertaking.

Clinical characteristics and risk factors for recurrence of anal fistula patients

To investigate the epidemiology, internal opening location, and risk factors associated with recurrence of anal fistula. Clinical data of 1783 hospitalized patients admitted for anal fistula treatment to Shanghai Shuguang Hospital from January 2013 to September 2015 were retrospectively analyzed. Fistula passing through anorectal ring or locating above was defined as high anal fistula (n=125). Internal opening location was defined as follows: posterior (5 to 7 o'clock), front(11 to 1 o'clock), left (2 to 4 o'clock) and right (8 to 10 o'clock). Among 1783 cases, 1526 were male with a median age of 36 years, 257 were female with a median age of 35 years, and the ratio of male to female was 5.9 vs 1.0. In high anal fistula cases, this ratio of male to female was 7.3 vs 1.0. Posterior internal opening accounted for 51.4%(884/1720), while this percentage was 66.4%(83/125) in high anal fistula cases, which was significantly higher than 50.2%(801/1595) in low anal fistula cases(P=0.002). Postoperative recurrence rate was 2.6%(45/1720) and the rates in high anal fistula and low anal fistula were 13.6%(17/125) and 1.8%(28/1595) respectively, with significant difference(P=0.000). Multivariate logistic regression analysis showed that fistula height(OR=5.475, 95%CI:2.230 to 13.445, P=0.000), treatment history(OR=2.671, 95% CI:1.315 to 5.424, P=0.007), seton placement history (OR=4.707, 95%CI:1.675 to 13.232, P=0.003) and concomitant colitis(OR=10.300, 95%CI:1.187 to 89.412, P=0.034) were independent risk factors for anal fistula recurrence. Seton placement history was an independent risk factor for high anal fistula recurrence (OR=6.476, 95%CI:1.116 to 37.589, P=0.037). Anal fistula occurs in young and middle-aged male patient. Internal opening locates in posterior more commonly, especially in high anal fistula patients. Postoperative recurrence rate of high anal fistula is quite high. Patient with both high anal fistula and seton placement history has significantly high rate of postoperative recurrence.

Primary posterior capsulotomy in adults with posterior capsule opacification

To evaluate the efficacy and safety of primary posterior continuous curvilinear capsulorhexis (PCCC) in adult patients with cataract. Zagazig University Hospital, Ash-Sharkya, Egypt. Prospective nonrandomized case series. This study comprised patients with senile cataract who had phacoemulsification. All patients had a dense posterior capsule opacification (PCO) discovered intraoperatively. Primary PCCC was performed to remove the residual opacification after posterior capsule polishing. All patients were followed for 3months postoperatively. The outcome measures were corrected distance visual acuity (CDVA), macular edema detected by optical coherence tomography, and the occurrence of intraoperative or postoperative complications. Twenty-five eyes of 25 cataract patients had phacoemulsification. The mean age was 61.9years±7.5 (SD). The mean CDVA preoperatively was 0.14±0.08 and postoperatively it was 0.86±0.15 at 1week, 0.93±0.08 at 1month, and 0.94±0.08 at 3months (P=.001). The mean central macular thickness was 313.16±8.39μm preoperatively and 315.04±10.6μm, 319.88±26.06μm, and 316.4±13.7μm at 1week, 1month, and 3months postoperatively, respectively (P=.35). Posterior capsule opening contracture occurred in 1 eye (4%), although it did not affect the patient's vision. Intraoperative posterior capsule extension occurred in 1 eye (4%). No serious complications, such as retinal detachment or endophthalmitis, were detected in any patient. Cataract surgery with primary PCCC was a safe procedure to treat residual PCO in adults and had a low rate of complications. Neither author has a financial or proprietary interest in any material or method mentioned.

Morphologic analysis of the proximal tibia after open wedge high tibial osteotomy for proper plate fitting.

BackgroundAfter open wedge high tibial osteotomy (OWHTO), the proximal fragment resembles the anatomy of the proximal tibia that is aligned in the anterior-posterior direction and the distal fragment resembles the anatomy of the mid shaft that is aligned in the proximal-distal direction. In addition, the medial portion of the proximal fragment becomes aligned medially and the medial portion of the distal fragment, laterally, depending on the magnitude of the posterior opening gap. Therefore, there would be a mismatch between the post-correction bony surface and the previous pre-contoured plate geometry. The purpose of this study was to devise a new plate that best fit the post-contoured anatomy of the tibia by evaluating the surface geometry of the plate positioning site after OWHTO.MethodsThirty-one uni-planar and 38 bi-planar osteotomies were evaluated. Surgical indications were age of under 70 years, relatively active patient who performs recreational sports activities. Other indications were similar with general recommendation of HTO. Computed tomography (CT) of the operated knees was performed and it was used for the reconstruction of the 3D model. Bone model axis re-alignment was performed with coronal, sagittal, and axial plane. Morphologic analysis of the proximal tibia was performed using the following parameters: (1) radii in axial plane, 2) radii in coronal plane, and 3) angle and horizontal distance (Distance X) between the proximal and distal fragments. These were also analyzed according to the correction degree. The Analysis of Variance (ANOVA) test was conducted to verify the change depending on the correction amount of the posterior opening gap. The values obtained for the uni- and bi-planar osteotomy were compared by the independent t-test.ResultsThere were 9 male and 60 female patients were recruited to this study; the mean age was 58.3 ± 8 and 56.9 ± 7.6 years, respectively. Preoperative weight bearing line (WBL) was 21.59 ± 11.36 and 22.32 ± 10.55 %, respectively. Mean correction degree was 10.9 ± 2.7 and 11.1 ± 2.6 mm, respectively. The radii of the tibial cross-sectional contour at the head portion tended to increase from the proximal to distal direction. The radii of the tibial cross-sectional contour at the neck portion tended to decrease from the proximal to distal direction. The radii of the coronal plane tended to increase from the proximal to distal direction. The angle between the proximal fragment and the distal one varied with the correction amount of the posterior opening gap. Shaft_Mid and Distance X of GroupI (110.08 mm and 6.11 mm, respectively) which had lower correction angle were lower than those of GroupII (130.05 mm and 6.41 mm, respectively) and those of GroupIII (136.35 mm, 8.01 mm, respectively) in coronal plane. There were significant differences (p = 0.023 < 0.05 and p = 0.009 < 0.01, respectively).ConclusionCurrent plate design should be modified to the surface geometry of the post-correction for the proper fitting. As the correction degree increases, the plate should be bended at the both end of the opening gap in coronal plane.Trial registration‘retrospectively registered (ISRCTN97792440).

A method of posterior fossa dural incision to minimize hemorrhage from the occipital sinus: the “mosquito” method

The posterior fossa dural opening requires the ligation of the occipital sinus to gain successful exposure. However, there could be a prominent occipital sinus which is functioning as the main drainage route and is harboring the risk of unpredictable massive hemorrhage during the dural opening. We introduce a safe method of posterior fossa dural incision to minimize hemorrhage from the occipital sinus using four curved hemostat clamps. For the dural incision at the midline part of the posterior cranial fossa, we used four curved hemostat clamps to occlude the prominent occipital sinus: one pair of clamps at the proximal part and the other pair at the distal part to occlude the occipital sinus. Dural incision was made between the two pairs of the curved hemostat clamps. By clamping of the sinus, it allows observation of possible brain swelling after occlusion of the occipital sinus as well as minimizes hemorrhage during incision of the midline dura of the posterior fossa. This method allows observation of brain swelling after occipital sinus occlusion and is an easy and safe incision of the midline dura minimizing hemorrhage in selected cases with a prominent occipital sinus.

Capsular Outcomes After Pediatric Cataract Surgery Without Intraocular Lens Implantation: Qualitative Classification and Quantitative Measurement.

The objective of this study was to investigate capsular outcomes 12 months after pediatric cataract surgery without intraocular lens implantation via qualitative classification and quantitative measurement.This study is a cross-sectional study that was approved by the institutional review board of Zhongshan Ophthalmic Center of Sun Yat-sen University in Guangzhou, China.Digital coaxial retro-illumination photographs of 329 aphakic pediatric eyes were obtained 12 months after pediatric cataract surgery without intraocular lens implantation. Capsule digital coaxial retro-illumination photographs were divided as follows: anterior capsule opening area (ACOA), posterior capsule opening area (PCOA), and posterior capsule opening opacity (PCOO). Capsular outcomes were qualitatively classified into 3 types based on the PCOO: Type I—capsule with mild opacification but no invasion into the capsule opening; Type II—capsule with moderate opacification accompanied by contraction of the ACOA and invasion to the occluding part of the PCOA; and Type III—capsule with severe opacification accompanied by total occlusion of the PCOA. Software was developed to quantitatively measure the ACOA, PCOA, and PCOO using standardized DCRPs. The relationships between the accurate intraoperative anterior and posterior capsulorhexis sizes and the qualitative capsular types were statistically analyzed.The DCRPs of 315 aphakic eyes (95.8%) of 191 children were included. Capsular outcomes were classified into 3 types: Type I—120 eyes (38.1%); Type II—157 eyes (49.8%); Type III—38 eyes (12.1%). The scores of the capsular outcomes were negatively correlated with intraoperative anterior capsulorhexis size (R = −0.572, P < 0.001), but no significant correlation with intraoperative posterior capsulorhexis size (R = −0.16, P = 0.122) was observed. The ACOA significantly decreased from Type I to Type II to Type III, the PCOA increased in size from Type I to Type II, and the PCOO increased from Type II to Type III (all P < 0.05).Capsular outcomes after pediatric cataract surgery can be qualitatively classified and quantitatively measured by acquisition, division, definition, and user-friendly software analyses of high-quality digital coaxial retro-illumination photographs.

Photodisruption of a thin membrane near a solid boundary: an in vitro study of laser capsulotomy

A Nd:YAG laser photodisruption is a well-established tool for intraocular surgery, such as treatment of posterior capsule opacification that affects the visual function. During the intraocular procedure, called laser capsulotomy, the excitation pulse is focused several times just behind the posterior capsule and intraocular lens to create the central opening in the opacified capsule. We built an in vitro experiment to (1) clarify the influence of the distance between the intraocular lens and the posterior capsule on the total pulse energy required for the capsulotomy, and (2) investigate the main mechanisms responsible for the posterior capsule opening. In our in vitro model, different distances between the solid boundary (imitating an intraocular lens) and the membrane (imitating the posterior capsule) simulate different types of posterior capsule opacification. Our results show that procedure efficiency decreases by decreasing distance between the lens and the capsule. We also explain that for smaller distances between the pulse focus and the membrane, plasma and shock wave are responsible for the capsule disruption. Here, a risk of collateral damage significantly increases. On contrary, the membrane and the bubble jet disrupt the membrane, when pulse focus is moved away and the risk of intraocular lens damage decreases. However, the membrane disruption is not very effective, if it is placed near the solid boundary that inhibits the membrane jet.

Effect of Wedge Insertion Angle on Posterior Tibial Slope in Medial Opening Wedge High Tibial Osteotomy.

Background:Medial opening wedge high tibial osteotomy (HTO) is a well-established surgery for medial compartment knee osteoarthritis (OA) wherein the lower extremity is realigned to shift the load distribution from the medial compartment of the knee to the lateral compartment. However, this surgery is known to affect the posterior tibial slope angle (PTSA), which could lead to abnormal knee kinematics and instability, and eventually to knee OA. Although PTSA control is as important as coronal realignment, few appropriate measurements for this parameter have been reported. The placement of a wedge spacer might have an effect on PTSA.Purpose:To elucidate the relationship between the PTSA and the direction of insertion of a wedge spacer.Study Design:Case series; Level of evidence, 4.Methods:This study assessed 43 knees from 34 patients who underwent medial opening wedge HTO for knee OA. Pre- and postoperative lateral radiographs of the knee as well as postoperative computed tomography scans were performed to evaluate the relationship among PTSA, wedge insertion angle (WIA), and opening gap ratio (distance of the anterior opening gap/distance of the posterior opening gap at the osteotomy site).Results:The PTSA significantly increased from 9.0° ± 2.8° preoperatively to 13.2° ± 4.1° postoperatively (P < .001), resulting in a mean ΔPTSA of 4.7° ± 4.5°. The mean opening gap ratio was 0.86 ± 0.11, and the mean WIA was 25.9° ± 8.4°. The WIA and opening gap ratio were both highly correlated with ΔPTSA (r = 0.71 and 0.72, respectively), implying that a smaller WIA or smaller gap ratio leads to less increase in posterior slope.Conclusion:The direction of wedge insertion is highly correlated with PTSA increase, which suggests that the PTSA can be controlled for by adjusting the direction of wedge insertion during surgery.Clinical Relevance:Study results suggest that it is possible to adjust the PTSA by controlling the WIA during surgery. Proper attention to WIA can avoid an iatrogenic increase in posterior tibial slope.

Comparison of Clinical and Radiological Results of Posterolateral Fusion and Posterior Lumbar Interbody Fusion in the Treatment of L4 Degenerative Lumbar Spondylolisthesis.

Study DesignMulticenter analysis of two groups of patients surgically treated for degenerative L4 unstable spondylolisthesis.PurposeTo compare the clinical and radiographic outcomes of posterolateral fusion (PLF) and posterior lumbar interbody fusion (PLIF) for degenerative L4 unstable spondylolisthesis.Overview of LiteratureSurgery for lumbar degenerative spondylolisthesis is widely performed. However, few reports have compared the outcome of PLF to that of PLIF for degenerative L4 unstable spondylolisthesis.MethodsPatients with L4 unstable spondylolisthesis with Meyerding grade II or more, slip of >10° or >4 mm upon maximum flexion and extension bending, and posterior opening of >5 degree upon flexion bending were studied. Patients were treated from January 2008 to January 2010. Patients who underwent PLF (n=12) and PLIF (n=19) were followed-up for >2 years. Radiographic findings and clinical outcomes evaluated by the Japanese Orthopaedic Association (JOA) score were compared between the two groups. Radiographic evaluation included slip angle, translation, slip angle and translation during maximum flexion and extension bending, intervertebral disc height, lumbar lordotic angle, and fusion rate.ResultsJOA scores of the PLF group before surgery and at final follow-up were 12.3±4.8 and 24.1±3.7, respectively; those of the PLIF group were 14.7±4.8 and 24.2±7.8, respectively, with no significant difference between the two groups. Correction of slip estimated from postoperative slip angle, translation, and maintenance of intervertebral disc height in the PLIF group was significantly (p<0.05) better than those in the PLF group. However, there was no significant difference in lumbar lordotic angle, slip angle and translation angle upon maximum flexion, or extension bending. Fusion rates of the PLIF and PLF groups had no significant difference.ConclusionsThe L4–L5 level posterior instrumented fusion for unstable spondylolisthesis using both PLF and PLIF could ameliorate clinical symptoms when local stability is achieved.

Anatomical study of pterygoid canal (PC) and palatovaginal canal (PVC) in endoscopic trans-sphenoidal approach.

The primary purpose of our work was to make anatomical measurements of pterygoid canal (PC) and palatovaginal canal (PVC). The secondary goal was to locate the two structures based on the landmarks in the trans-sphenoidal surgery and draw a safe corridor of fenestration in the bottom of sphenoid sinus during surgical procedure to sphenopalatine region. Computed tomographic angiography (CTA) images of PC, PVC and sphenoid sinus in 200 adults were reviewed. Multiplanar reconstruction of the CT images was performed, and the anatomical features of the PC and PVC were studied in the coronal, sagittal, and axial planes. The length, diameter and direction of PC and PVC were measured in the plane through or perpendicular to them. The anterior and posterior opening of PC and PVC were identified by the surgical landmarks such as the middle lowest point of sellar floor, the sagittal midline and the bottom of the sphenoid sinus. Both PC and PVC can be found and identified easily on CTA image, the shape and size of the PC and PVC were in agreement with those retrieved from previous literatures, the position of them can be located by the anatomical landmarks in sphenoid sinus. Knowing the anatomical features of PC and PVC and their location based on the anatomical landmarks are helpful to the endoscopic trans-sphenoidal surgery. These data in our study will provide surgeons a better understanding of PC and PVC and their relationship to sphenoid sinus. Notably, it will not help the surgeons to avoid injuring neurovascular structures as well as provided supportive information for the choice of the appropriate endoscopic equipment.

A rare case of congenital Y-type urethral duplication

Duplication of urethra is a rare congenital anomaly. We report a case of Y-type of urethral duplication with the accessory urethra arising from posterior urethra and opening in the perineum. The orthotopic urethra was normal. The accessory urethral tract was cored, transfixed and divided. At 1 year of follow-up, the patient has no urinary complaints.