Rotator cuff repair with an interposition polypropylene mesh: A biomechanical ovine study.

BACKGROUND: Chronic large to massive rotator cuff tears are difficult to treat and re-tears are common even after surgical repair. We propose using a synthetic polypropylene mesh to increase the tensile strength of rotator cuff repairs. We hypothesize that using a polypropylene mesh to bridge the repair of large rotator cuff tears will increase the ultimate failure load of the repair. AIM: To investigate the mechanical properties of rotator cuff tears repaired with a polypropylene interposition graft in an ovine ex-vivo model. METHODS: A 20 mm length of infraspinatus tendon was resected from fifteen fresh sheep shoulders to simulate a large tear. We used a polypropylene mesh as an interposition graft between the ends of the tendon for repair. In seven specimens, the mesh was secured to remnant tendon by continuous stitching while mattress stitches were used for eight specimens. Five specimens with an intact tendon were tested. The specimens underwent cyclic loading to determine the ultimate failure load and gap formation. RESULTS: The mean gap formation after 3000 cycles was 1.67 mm in the continuous group, and 4.16 mm in the mattress group (P = 0.001). The mean ultimate failure load was significantly higher at 549.2 N in the continuous group, 426.4 N in the mattress group and 370 N in the intact group (P = 0.003). CONCLUSION: The use of a polypropylene mesh is biomechanically suitable as an interposition graft for large irreparable rotator cuff tears.

Relevance of presenting risks of frailty, sarcopaenia and osteopaenia to outcomes from aneurysmal subarachnoid haemorrhage.

INTRODUCTION: Aneurysmal subarachnoid haemorrhage (aSAH) is a condition with significant morbidity and mortality. Traditional markers of aSAH have established their utility in the prediction of aSAH outcomes while frailty markers have been validated in other surgical specialties. We aimed to compare the predictive value of frailty indices and markers of sarcopaenia and osteopaenia, against the traditional markers for aSAH outcomes. METHODS: An observational study in a tertiary neurosurgical unit on 51 consecutive patients with ruptured aSAH was performed. The best performing marker in predicting the modified Rankin scale (mRS) on discharge was selected and an appropriate threshold for the definition of frail and non-frail was derived. We compared various frailty indices (modified frailty index 11, and 5, and the National Surgical Quality Improvement Program score [NSQIP]) and markers of sarcopaenia and osteopaenia (temporalis [TMT] and zygoma thickness), against traditional markers (age, World Federation of Neurological Surgery and modified Fisher scale [MFS]) for aSAH outcomes. Univariable and multivariable analysis was then performed for various inpatient and long-term outcomes. RESULTS: TMT was the best performing marker in our cohort with an AUC of 0.82, Somers' D statistic of 0.63 and Tau statistic 0.25. Of the frailty scores, the NSQIP performed the best (AUC 0.69), at levels comparable to traditional markers of aSAH, such as MFS (AUC 0.68). The threshold of 5.5 mm in TMT thickness was found to have a specificity of 0.93, sensitivity of 0.51, positive predictive value of 0.95 and negative predictive value of 0.42. After multivariate analysis, patients with TMT ≥ 5.5 mm (defined as non-frail), were less likely to experience delayed cerebral ischaemia (OR 0.11 [0.01 - 0.93], p = 0.042), any complications (OR 0.20 [0.06 - 0.069], p = 0.011), and had a larger proportion of favourable mRS on discharge (95.0% vs. 58.1%, p = 0.024) and at 3-months (95.0% vs. 64.5%, p = 0.048). However, the gap between unfavourable and favourable mRS was insignificant at the comparison of 1-year outcomes. CONCLUSION: TMT, as a marker of sarcopaenia, correlated well with the presenting status, and outcomes of aSAH. Frailty, as defined by NSQIP, performed at levels equivalent to aSAH scores of clinical relevance, suggesting that, in patients presenting with acute brain injury, both non-neurological and neurological factors were complementary in the determination of eventual clinical outcomes. Further validation of these markers, in addition to exploration of other relevant frailty indices, may help to better prognosticate aSAH outcomes and allow for a precision medicine approach to decision making and optimization of best outcomes.

Simultaneous bilateral hallux valgus surgery: Percutaneous or conventional? Early results of a matched study from a tertiary institution.

BACKGROUND: Hallux valgus is bilateral in up to 84 % of cases. In the setting of simultaneous bilateral correction, we aim to evaluate if minimally invasive percutaneous surgery (MIS) provides any advantage compared to conventional open surgery. METHODS: 52 feet (26 patients) undergoing simultaneous bilateral MIS surgery were matched by severity of deformity to 52 feet (26 patients) undergoing simultaneous conventional open surgery. Patients were followed for a minimum of six months. Pre- and post-operative radiographs and clinical records were reviewed. RESULTS: There were no significant differences in pre-operative function or pain between both groups. Post-operatively, the mean hallux valgus angle (HVA) was significantly lower in the MIS group. (HVA MIS - 8.6; Open - 11.8, P = 0.013). There were no significant differences in post-operative outcome and patient satisfaction between both groups. CONCLUSION: This study demonstrates that simultaneous bilateral MIS hallux valgus surgery can be considered for patients with bilateral symptomatic hallux valgus.

Is single stage capsular release and rotator cuff repair suitable for rotator tears with concomitant stiffness?

INTRODUCTION: It is common for patients with a rotator cuff tear to present with shoulder stiffness. There is no consensus on the acceptable level of stiffness at time of rotator cuff repair.We aim to determine if patients with stiffness undergoing rotator cuff repair and concomitant capsular release have different outcome than those with no stiffness undergoing rotator cuff repair alone. We hypothesize that patients with stiffness will not have poorer outcome than patients with no stiffness. METHOD: We conducted a retrospective study of prospectively collected data for 47 patients who underwent arthroscopic rotator cuff repair under a single surgeon from 2010 to 2015. 25 patients were considered stiff (Stiff group) and 22 patients were considered to have no pre-operative stiffness (Non-stiff group).Range of motion and functional outcomes were collected preoperatively and post-operatively at two-years. RESULTS: There were no significant differences in gender distribution, age and cuff tear size between both groups. Pre-operatively, patients in the Stiff group had significantly poorer active range of motion (Forward flexion - Stiff 74.8° vs Non-stiff 100.2°, P = 0.001) and poorer function (Constant score - Stiff 23.5 vs Non-stiff 43.2, P < 0.001). Post-operatively, both groups of patients had increased range of motion, strength and reported lesser pain compared to pre-operation. There were no significant differences in post-operative outcomes between both groups. CONCLUSION: Single-stage surgery combining capsular release and rotator cuff repair is effective for patients with stiffness as they are able to achieve similar results to those without shoulder stiffness.

Women Do Not Have Poorer Outcomes After Minimally Invasive Lumbar Fusion Surgery: A Five-Year Follow-Up Study.

BACKGROUND: Women undergoing lumbar spine surgery report greater preoperative pain and disability and have less improvement after surgery. There is a paucity of literature on sex-related differences after minimally invasive surgery transforaminal lumbar interbody fusion (MIS TLIF) surgery. We aim to determine whether sex influences outcome after MIS TLIF at 5-year midterm follow-up. METHODS: Prospectively collected registry data for 907 patients who underwent MIS TLIF at a single institution from 2004 to 2013 were reviewed. Of these, 296 patients (94 males and 202 females) were reviewed at 5-year follow-up. All patients were assessed preoperatively and postoperatively at 2 and 5 years. Data recorded included patient demographics, Oswestry Disability Index (ODI), Short-Form 36 Physical and Mental component scores (SF-36 PCS and MCS), and the North American Spine Society lumbar spine outcome assessment instrument. RESULTS: Females who underwent MIS TLIF were generally younger (females, 52.2 years; males, 56.1 years; P = .04). Females had significantly poorer preoperative ODI (females, 49.5; males, 41.5; P < .001) and SF-36 PCS (females, 31.9; males, 35.6; P < .01) and MCS (females, 44.9; males, 49.2; P < .01) scores. At 2-year and 5-year follow-up, there were no significant differences in ODI, SF-36, and pain scores between sexes. Both groups reported similar proportions that returned to work and returned to function. There were no differences in proportion of patients who were satisfied or had their expectations fulfilled. CONCLUSIONS: Women who undergo MIS TLIF have poorer preoperative function and quality of life than men. However, women demonstrated greater improvement after surgery, attaining similar clinical outcomes at 5-year follow-up. LEVEL OF EVIDENCE: 3.

The Effect of Renal Transplantation in End-Stage Renal Failure Patients Undergoing Total Hip Replacement.

BACKGROUND: Patients with end-stage renal failure (ESRF) undergoing elective orthopedic surgery generally have higher postoperative morbidity and mortality compared to the general population. Studies on the outcome of ESRF patients undergoing total hip replacement (THR), especially those with a functioning renal transplant, are conflicting. We aim to evaluate the impact of renal transplantation on functional outcome and postoperative complications in patients with ESRF undergoing THR. MATERIALS AND METHODS: A total of 29 primary THRs were performed in 25 patients with ESRF between 1999 and 2013. There were 12 patients with 14 THRs who had a functioning renal transplant at the time of surgery (transplant group), and 13 patients with 15 THRs who were dialysis dependent with either no or failed prior transplant (nontransplant group). Functional outcome was evaluated with the Oxford Hip Score (OHS) and Western Ontario and McMaster Universities Osteoarthritis Index. Clinical records and followup radiographs were used to evaluate postoperative complications. RESULTS: There is lower mortality rate (P = 0.02) and lower overall complication rate in the transplant group compared to the nontransplant group (relative risk 0.60, 95% confidence interval 0.40-0.91, P = 0.008). The mean increase in OHS postoperatively was greater in the nontransplant group (nontransplant-24.7; transplant-18.7) and trended toward statistical significance (P = 0.06). CONCLUSION: ESRF patients who undergo THR experience improvements in functional outcome regardless of transplant status. There was no significant difference in postoperative functional outcomes between the two groups of patients, but patients with renal transplants are less likely to experience postoperative complications and have better survival.

The effect of gender in hallux valgus surgery. A propensity score matched study.

BACKGROUND: Males and females who undergo hallux valgus (HV) surgery have different expectations. METHODS: Data from 439 patients, with 26 males, were prospectively collected between 2007-2015. Propensity score matching (PSM) of one male to two females was performed using logistic regression of six variables to minimize selection bias. Hallux visual analogue scale (VAS) scores, AOFAS scores, SF-36, satisfaction and expectation scores were analysed at two years. RESULTS: There were no significant differences in patient demographics after PSM. At two years, males and females attained similar VAS and AOFAS scores but males had significantly lower SF-36 general health score (males 68.7, females 79.3). 26.9% of males and 21.2% of females were not satisfied after surgery. Higher proportion of males did not have their expectations fulfilled (males 19.2%, females 5.8%) although this was not statistically significant. CONCLUSIONS: Both genders attain similar outcome at two years. There is a trend towards lower expectation fulfilment in males after surgery.

Unexplained Pain Post Total Knee Arthroplasty With an Oxford Knee Score ≥20 at 6 Months Predicts Good 2-Year Outcome.

BACKGROUND: Total knee arthroplasty (TKA) is an effective procedure for end-stage osteoarthritis of the knee. Some patients experience persistent unexplained pain post-TKA despite normal investigations. The purpose of this study is to identify which of these patients are likely to improve without any surgical intervention. We hypothesize that patients with unexplained persistent pain and a poor 6-month Oxford knee score (OKS) post-TKA can improve at 2 years. METHODS: Prospectively collected data for all primary unilateral TKA performed from June 2004 to January 2012 were analyzed to identify which patients with unexplained pain at 6 months will improve at 2 years. Patients were included if they had persistent pain and an OKS <27 at 6 months; normal radiological and clinical investigations; no infection identified; surgery performed for primary osteoarthritis. Two hundred sixty patients with OKS <27 at 6 months were analyzed. These patients were subdivided into 2 groups (group 1: 6-month OKS 20-26, group 2: 6-month OKS less than 20). RESULTS: One hundred ninety-one out of 208 (92%) patients in group 1 experienced improvement in pain and outcome at 2 years. Most of the group 1 patients attained a minimal clinically important difference in OKS of at least 5 (P < .001) at 2 years. Group 1 patients also reported better Knee Society Functional Score and Short Form Survey 36 mean scores at 2 years. CONCLUSION: In patients with unexplained pain, an OKS of at least 20 at 6 months predicts good functional outcome at 2 years.

Accelerometer-Based Navigation Is as Accurate as Optical Computer Navigation in Restoring the Joint Line and Mechanical Axis After Total Knee Arthroplasty: A Prospective Matched Study.

The Zimmer iASSIST system is a novel accelerometer-based navigation system for TKA. 76 patients (76 knees) were prospectively matched for age, BMI, gender, diagnosis, and pre-operative scores, and underwent TKA using the iASSIST (n=38) or optical CAS (n=38). There were no significant differences in clinical outcomes or satisfaction rates at six months post-operatively (P>0.05). Mechanical axis was 1.8±1.3° in the iASSIST cohort versus 2.1±1.6° in the CAS cohort (P=0.543). There were no significant differences in number of outliers for mechanical axis (P=1.000), coronal femoral-component angle (P=0.693), coronal tibial-component angle (P=0.204) or joint line deviation (P=1.000). The duration of surgery was significantly longer in the CAS group (P<0.001), while the added cost of accelerometer-based navigation was approximately $1000 per operation.

Intra-operative correction of volar tilt of distal radius fractures using volar locking plate as reduction tool: review of 24 cases.

In surgical fixation of distal radius fractures with metaphyseal comminution, volar tilt can be restored using an anatomical volar locking plate as a reduction tool. The purpose of our study is to assess the degree of over or under correction of volar tilt that can result with our 'lift' technique and to determine the ratio between theoretical and actual angular correction. We retrospectively reviewed 24 patients who underwent distal radius fracture fixation using this technique and assessed intra-operative radiographs for parameters including pre-'lift' and post-'lift' volar tilt and pre-'lift' plate-shaft angles. The ratio between actual angular correction and theoretical angular correction was calculated. The 'lift' technique is found to be reliable in restoring volar tilt in most fractures. Over- or under-correction does occur due to errors in visual estimation and actual angular correction is generally less than the theoretical angular correction.

WITHDRAWN: Primary CNS lymphoma and high-grade glioma: differentiation using perfusion and proton spectroscopic MR imaging.

This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

The MERCI Retrieval System for the management of acute ischaemic stroke--the NNI Singapore experience.

INTRODUCTION: Systemic and local intra-arterial thrombolysis in patients with large vessel ischaemic stroke is hampered by poor re-canalisation rates and risk of haemorrhage. The Merci Retrieval System is an endovascular device for removal of acute intracranial thrombus. We present our initial experience using this device in conjunction with existing thrombolytic therapy already in place in our institute. MATERIALS AND METHODS: Prospective data in all patients presenting with large vessel ischaemic stroke treated using the Merci Retrieval System from July 2007 to March 2009 were analysed. Selection criteria for patients were similar to the multi- Merci trial of 2008. We compared re-canalisation rate, National Institutes of Health Stroke Score (NIHSS) and modified Rankin score (mRS) outcomes to the published trial results. RESULTS: Seventeen patients were reviewed; none suffered immediate post-procedural complications. Fifteen underwent successful thrombus retrieval but in 2 cases the device failed due to technical considerations. Sites of vascular occlusion included: ICA/ICA-'T' junctions 27%, middle cerebral artery 13% and vertebrobasilar artery 60%. Of the 15 patients treated by MERCI with or without adjuvant thrombolytic therapy, complete re-canalisation was achieved in 60%, partial re-canalisation in 20%, partial re-canalisation with persistent distal vessel occlusion in 6% and failure of re-canalisation in 14%. Asymptomatic haemorrhage occurred in 33% and there was 1 death (6%) from symptomatic haemorrhage. Pre-treatment median NIHSS was 17.88 and 9.5 immediately post-treatment. Median mRS at 30 days was 2.6 for patients who achieved complete re-canalisation and 4.5 in failure or partial re-canalisation with or without persistent distal vessel occlusion. CONCLUSION: Re-canalisation rates using the Merci Retrieval System was comparable to the multi-Merci trial. Haemorrhagic complications and safety were also found to be satisfactory. Importantly, treatment success with eventual good clinical outcome hinges strongly on the ability of the device to achieve complete re-canalisation.

Stent-assisted percutaneous angioplasty for extra-cranial carotid disease:experience at Singapore General Hospital.

INTRODUCTION: This study aims to analyse the results of carotid stenting in a tertiary referral centre in Singapore. MATERIALS AND METHODS: Retrospective analysis of all carotid artery stenting (CAS) cases in a single centre from March 1997 to December 2008 was performed. Sixty successful procedures were performed in 61 patients, with bilateral stenting in 1 patient, and 2 failed procedures. The majority were Chinese (78.7%) and males (77.0%), with a high proportion having hypertension (82.0%) and hypercholesterolaemia (78.7%). The majority (91.8%) of patients were high surgical risk candidates, primarily due to cardiac risk factors. Ten patients (16.4%) had prior neck irradiation for nasopharyngeal carcinoma, and 3 patients each (4.9%) had previous endarterectomy and contralateral occlusion. A distal embolic protection device was used in 71.7% of cases. RESULTS: Technical success was 96.8%. The 30-day stroke and death rate was 13.8%, comparable to reported results for this high surgical risk population. CONCLUSION: CAS is a technically feasible and a relatively safe alternative to endarterectomy to treat extracranial carotid stenosis, especially in patients who are inoperable or at high surgical risk.

Clinical functional magnetic resonance imaging for pre-surgical planning--the Singapore General Hospital experience with the first 30 patients.

INTRODUCTION: Functional magnetic resonance imaging (fMRI) is a neuroradiological technique for the localisation of cortical function. FMRI made its debut in cognitive neuroscience and then eventually to other clinical applications. We report our experience with pre-surgical fMRI on a high field scanner, based purely on a clinical platform. MATERIALS AND METHODS: The protocols included motor, auditory, visual and language fMRI. The choice of protocols was dependant on clinical request and lesion locale. RESULTS: Retrospective analysis and audit of the fi rst 30 consecutive patients over a 12-month period revealed that about 85% of patients had a successful examination. In a pictorial essay, we demonstrate that patients with weakness in performing a motor task showed abnormal activations of the pre-motor and supplementary motor areas. CONCLUSION: FMRI data greatly enhances the pre-surgical planning process and the conduct of surgery when it is incorporated into the surgical navigation system in the operating theatre.

Bilateral orbital varices: an approach to management.

The authors report a case of bilateral orbital varices in a 19-year-old man with a 7-year history of intermittent left proptosis and dystopia. CT demonstrated enhancing lesions with phleboliths and gadolinium-enhanced MRI showed characteristic hyperintense lesions. The asymptomatic right lesion was treated conservatively; the left lesion was excised following intralesional injection of cyanoacrylate. Bilaterality in orbital varices may not be obvious clinically and only diagnosed radiologically. A multidisciplinary approach involving the ophthalmologist and interventional radiologist using intraoperative fluoroscopy enabled accurate characterization, delineation, embolizationm, and excision of the lesion with good hemostatic control.

High-flow hemangioblastoma of the orbit.

A 62-year-old Chinese man was found to have a mass in the right superior orbit and mild fullness in right cavernous sinus associated with minimal proptosis. Carotid artery angiography revealed a vascular tumor in the superior orbit with supply from the internal and external carotid arteries. Selective embolization of the feeder vessel was performed before surgical excision of the tumor. Histopathologic examination with light microscopy and immunohistochemistry confirmed the tumor to have characteristics of a hemangioblastoma. Hemangioblastoma involving the orbit is exceedingly uncommon and to date only one such case has been documented in the literature.

A meta-analysis of unrelated donor umbilical cord blood transplantation versus unrelated donor bone marrow transplantation in adult and pediatric patients.

Several studies have compared the results of unrelated donor bone marrow transplantation (UBMT) and unrelated donor cord blood transplantation (UCBT). To objectively analyze these data, we performed a systematic review and meta-analysis of pooled data on comparative studies of UCBT and UBMT in patients requiring hematopoietic stem cell transplantation. Combining the studies, 161 children and 316 adults undergoing UCBT (mostly 1 or 2 antigen-mismatched), along with 316 children and 996 adults undergoing UBMT (almost entirely fully matched with the recipient), were analyzed. T-cell-depleted UBMT was excluded; where data were available, only fully matched UBMT was used in the analysis. Pooled comparisons of studies of UCBT and UBMT in children found that the incidence of chronic graft-versus-host disease (GVHD) was lower with UCBT (relative risk [RR] = 0.26; 95% confidence interval [CI] = 0.12-0.57; P = .16), but the incidence of grade III-IV acute GVHD did not differ (RR = 1.46; 95% CI = 0.42-5.03; P = .55). There was no difference in 2-year OS in children when studies were pooled (RR = 0.76; 95% CI = 0.31-1.87; P = .55). For adults, transplantation-related mortality (pooled estimate, 1.04; 95% CI = 0.52-2.08; P = .91) and disease-free survival (DFS) (pooled estimate, 0.59; 95% CI = 0.18-1.96; P = .39) were not statistically different. Because of the unavailability of randomized controlled trials, pooled analysis of nonrandomized comparative studies was performed. Thus, our meta-analysis confirmed that UCBT in children and adults had consistently equivalent survival outcomes compared with UBMT despite greater donor-recipient HLA disparity with UCBT.

Vertebrae adjacent to spinal bone lesion are inconsistent reference markers: a magnetic resonance spectroscopic viewpoint.

PURPOSE: To ascertain the suitability of vertebrae adjacent to spinal bone lesions as a signal intensity reference on MRI, and compare the MR spectroscopic appearance of vertebral body compression fractures due to malignant tumor infiltration, bone weakening (e.g., osteoporosis), and/or minor trauma. MATERIALS AND METHODS: Twenty-five patients with spinal compression fractures underwent routine spinal MRI with an additional 1H MRS study protocol to assess the percent fat fraction of the compressed vertebrae as well as the adjacent bony environment. Peak areas for water and total lipid were calculated from short-TE single-voxel 1H MR spectra using the LCModel analyzing tool. RESULTS: There were consistent water-only patterns in the fractured vertebra suggesting either near complete marrow replacement by malignant tissue or local edematous fluid/hemorrhage within the marrow spaces. However, the adjacent vertebrae showed a wide range of patterns from a dominant lipid signal to the inverse of a pronounced water level. These results far exceed the normal variation expected based on age and sex. CONCLUSION: The results suggest that the adjacent vertebrae may not be an accurate reference, especially in diffusion-weighted imaging (DWI), because of the large difference between the two compartments. Furthermore, in the case of gradient-echo measurements, the in-phase vs. opposed-phase effects are significant.

A survey of vitamin D level in people with learning disability in long-stay hospital wards in Hong Kong.

Serum vitamin D level was measured in 122 patients with learning disabilities in long-term care wards. Such people are at risk of developing vitamin D deficiency. Low vitamin D is often attributed to lack of sunshine, poor dietary intake and the deleterious effect of anticonvulsant therapy. The results of this study confirmed that a low level of vitamin D (14.38 +/- 7.9 nmol/l) prevails, regardless of anticonvulsant usage. Sunshine exposure was virtually non-existent for most patients. Research has shown that when sunlight exposure is limited, osteomalacia in the British Asian community is determined by dietary factors. Our subjects had three types of diet: standard, soft and tube feeding. For both males and females, the tube feeding group had a significantly higher mean level of vitamin D than the other groups. Regular sunshine exposure is recommended for people requiring long-term infirmary care; alternatively, dietary supplement of vitamin D should be considered.

Concomitant diminishing magnetization-transfer effect and increasing choline level in radiation-induced temporal-lobe changes.

This article reports on the use of both magnetization-transfer (MT) imaging and 1H-MR spectroscopy in two cases of bilateral temporal-lobe changes after radiation therapy for nasopharyngeal carcinoma. In the first case, the following patterns were noted: (i) although the temporal lobes appeared relatively normal on T2-weighted MR imaging, corresponding MT imaging clearly showed signal abnormalities (decreased MT effect) consistent with alterations in macromolecular structure; and (ii) concomitant strongly elevated choline on 1H-MR spectroscopy was observed, and this is associated with metabolic changes in cell membranes. The second case presented similar characteristics. In addition, there was an increased lactate signal and T2 signal changes in keeping with established oedema. Both MT and proton-spectroscopic findings were consistent with postulated pathophysiological features of radiation injury, but their specificity for this condition remains unclear. Magnetization-transfer imaging, and possibly 1H-MR spectroscopy, might be sensitive techniques for the early detection of late radiation injury.