An analysis of the Oxford Shoulder Score and its relationship to early joint revision in the New Zealand Joint Registry.

BACKGROUND: Primary shoulder arthroplasties significantly improve shoulder function and have acceptable prosthesis survival for various indications. Currently, no validated shoulder questionnaire exists that can anticipate the early failure of primary shoulder arthroplasties. This study hypothesized that the Oxford Shoulder Score (OSS) after primary shoulder arthroplasty at 6 months would be significantly associated with early revision procedures. METHODS: Data on all primary and revision shoulder arthroplasties covering the period of January 1, 1999, to December 31, 2019, were obtained from the New Zealand Joint Registry. The OSS questionnaires at 6 months were analyzed with regard to their relationship to revision within 2 years from the questionnaire date. Confounding risk factors were adjusted for in multivariate logistic regression analysis. RESULTS: Statistical analysis revealed that the 6-month OSS had a significant association with revision in the following 2 years for anatomic total shoulder arthroplasty (TSA), reverse total shoulder arthroplasty (RSA), and shoulder hemiarthroplasty (HA) (P < .001). An OSS of ≤44 for TSAs, ≤40 for RSAs, and ≤33 for HAs accounted for 68.9%, 63.1%, and 50.7%, respectively, while capturing at least 85% of revisions for all prostheses within the following 2 years. CONCLUSION: This study confirms that a poor OSS at 6 months is an independent risk factor for early revision after TSA, RSA, and HA. We recommend discharging patients with a 6-month OSS greater than the identified threshold values for each prosthesis to improve resource efficiency.

Arthroscopic assessment of patella tracking correlates with recurrent patellar instability.

PURPOSE: For recurrent lateral patellar instability surgical algorithm, an arthroscopic assessment of patellar tracking can aid with the decision of adding a tibial tubercle transfer procedure based on knee flexion angle at which patella centrally engages in its groove. Tibial tubercle-trochlear groove distance is variable in normal values and has discrepancies between imaging modalities. The aims of our study were to assess correlation of arthroscopic patellar tracking technique with recurrent patellar instability, and to assess the accuracy and reproducibility of this technique. METHODS: 157 patients were evaluated, 64 control patients with no patellar instability, and 93 patients with recurrent patellar instability. This included 57 consecutive knee arthroscopy procedures evaluated for accuracy and reproducibility of our technique. The technique involved low flow arthroscopy and anterolateral viewing portal. Patients' knees were extended from a flexed position of 120°, and paused when the patella disengaged from its groove. The KFA was then estimated by the primary surgeon, and compared with a goniometer measurement. The assisting surgeon, blinded to the primary surgeon measurements, repeated this process. For the primary outcome, goniometer readings for KFA from the primary surgeon were used to correlate with patellar instability diagnosis. RESULTS: Patients with patellar instability had a mean KFA of 118° compared to 44°for patients without patellar instability (p < 0.001). The mean difference between goniometer reading and estimation of KFA by each surgeon was 5° (p < 0.001) with intra-class correlation of 0.99. The mean difference between the two surgeons' goniometer readings was 8° (p < 0.001) with intra-class correlation of 0.99. CONCLUSION: This study confirms arthroscopic assessment of patella tracking is accurate, reproducible, and a knee flexion angle of greater than 44° correlates with patellar instability diagnosis. Patella tracking can be used as an adjunct or an alternative assessment method to tibial tubercle-trochlear groove distance to determine the need for tibial tubercle transfer in patellar stabilisation surgery. LEVEL OF EVIDENCE: Prospective Cohort Study, Level III.

Pretubercular Subcutaneous Thickness Is a Protective Factor for Superficial Wound Complications After Total Knee Arthroplasty in Nonmorbidly Obese Patients.

BACKGROUND: Anterior knee subcutaneous thickness has been associated with increased risk of early reoperation for surgical site infection after primary total knee arthroplasty (TKA) in morbidly obese patients. However, most patients undergoing TKA are not morbidly obese. The aims of this study were to (1) assess the association between anterior knee subcutaneous thickness and early superficial wound complications and (2) determine a threshold value for anterior knee subcutaneous thickness measures that can assist in preoperative risk stratification in nonmorbidly obese TKA patients. METHODS: Using retrospective analysis, we reviewed 494 primary TKAs performed in patients with a body mass index <40 kg/m2 at our institution from January 1, 2010 to December 31, 2017. All patients developing a superficial surgical site infection within 90 days of index arthroplasty requiring treatment with antibiotics or reoperation were identified. Prepatellar thickness and pretubercular thickness were measured on preoperative lateral radiographs and associated with 90-day superficial wound complications. RESULTS: Sixty-two of the 494 patients developed a superficial wound complication within 90 days of index arthroplasty. TKA patients in the superficial wound complication group had significantly less pretubercular thickness (P = .027). Risk of developing 90-day superficial wound complication was 1.85-fold lower when pretubercular thickness was ≥12 mm (P = .028). Prepatellar thickness (P = .895) was not significantly associated with superficial wound complications. CONCLUSION: Increased pretubercular thickness is a protective factor for developing superficial wound complications, with 12 mm being an ideal threshold value for preoperative risk stratification in nonmorbidly obese patients undergoing primary TKA surgery.

Single versus triple injection ultrasound-guided infraclavicular block: confirmation of the effectiveness of the single injection technique.

BACKGROUND: The optimal site for local anesthetic placement during ultrasound-guided infraclavicular block remains controversial. METHODS: Patients were randomized to receive lidocaine 2% 30 mL as a single injection posterior to the axillary artery (n = 51) or a triple injection ideally adjacent to each brachial plexus cord (n = 49). Pinprick sensory and motor block (3 = no block, 0 = complete block) were assessed to 20 minutes in the 4 distal nerve territories. RESULTS: The single injection group was not significantly inferior (single versus triple injection median [interquartile range] 20-minute aggregate block score: 5 [2-9] vs 7 [3.5-11]) but also demonstrated superiority (2-tailed test, P = 0.043). The single injection technique was associated with a small reduction in procedural time. CONCLUSIONS: The optimal site for local anesthetic placement during ultrasound-guided infraclavicular block is a single point injection posterior to the axillary artery.

Revision Following Cemented and Uncemented Oxford-III Primary Medial Unicompartmental Knee Replacements: A 19-Year Analysis from the New Zealand Joint Registry.

BACKGROUND: Oxford-III unicompartmental knee replacements (UKRs) are among the most commonly used prostheses to treat isolated medial compartment osteoarthritis (OA). However, the best mode of implant fixation for primary UKRs remains a source of debate. The hypothesis of this study was that the biologically superior fixation of uncemented Oxford-III primary UKRs would translate into a lower revision rate when compared with cemented Oxford-III primary UKRs used to treat isolated medial compartment OA. METHODS: Data on all Oxford-III primary UKRs (n = 8,733) completed for isolated medial compartment OA from January 2000 to December 2018 were obtained from the New Zealand Joint Registry (NZJR). Revision rates were documented for each fixation type and analyzed for associations with patient sex and age at surgery. A multivariate Cox proportional-hazards analysis was completed to determine if type of fixation was an independent risk factor for revision of Oxford-III UKRs. RESULTS: Statistical analysis revealed a >1.8-fold greater revision risk for cemented Oxford-III UKRs compared with uncemented Oxford-III UKRs (p = 0.001) when considered independently of other risk factors. Furthermore, compared with uncemented fixation, cemented fixation was associated with a 2.9-fold (p < 0.001) increase in revision risk for women <65 years old and a 1.7-fold (p = 0.008) increase in revision risk for men 55 to 74 years old. There was no significant difference in the risk of revision between fixation methods for women ≥65 years old and men ≥75 years old. CONCLUSIONS: We found that the type of fixation was an independent risk factor for revision of Oxford-III UKRs used in the treatment of isolated medial compartment OA. Uncemented Oxford-III primary UKRs had superior implant survivorship in women <65 years old and men 55 to 74 years old. Age and sex are important factors to consider when determining the type of fixation for Oxford-III primary UKRs used to treat isolated medial compartment OA. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

A survey of surgical techniques for catheterising the cerebral lateral ventricles.

The objective of this paper is to characterise the frequency of different surgical techniques for targeting the lateral ventricle in shunt surgery and the attitudes of Australasian neurosurgeons and advanced neurosurgical trainees to stereotactic adjuncts. Secondarily, we aim to learn from and collate the practical experiences of neurosurgeons for those attempting to improve their operative success. A survey of all practising and training members of the Neurosurgical Society of Australasia (NSA) was conducted. One hundred and eleven surveys were completed generating an overall response rate of 57%. Of those 108 performing shunt surgery, 10 (9%) preferred a frontal approach and 70 (65%) a posterior approach to the frontal horn. Twenty-seven neurosurgeons (25%) preferred the posterior approach to the atrium or body of the lateral ventricle. A wide range of burr hole sites and targeting landmarks were described and are discussed. There was no consistent pattern for neurosurgeons changing their preferred approach during their careers. Seventy-five per cent of respondents make adjustments to measurements for children by a wide range of methods. Frameless or frame-based stereotaxy is used at times by about half of all neurosurgeons. Posterior approaches to the lateral ventricle using freehand techniques are preferred among NSA members and their trainees but there are a wide variety of landmarks used. Many of these techniques have been developed over years of operative experience and could be modelled with planning software to assess their theoretical merits. There is no evidence of the uptake of generic accuracy guides but there is evidence of significant exposure to frameless stereotactic techniques that may grow in popularity as the technology improves.

Efficacy of the Adductor Canal Approach to Saphenous Nerve Block for Anterior Cruciate Ligament Reconstruction With Hamstring Autograft: A Randomized Controlled Trial.

BACKGROUND: For reconstruction of the anterior cruciate ligament (ACL) with hamstring autograft, perioperative analgesia can be achieved with multimodal analgesia and intra-articular local anesthesia infiltration with or without additional regional blocks. Saphenous nerve block (SNB) via the adductor canal is commonly used in our practice, but its benefit has not been well established in the literature. PURPOSE: To assess the efficacy of SNB in ACL reconstruction with hamstring autograft. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: Consecutive patients undergoing arthroscopic ACL reconstruction with hamstring autograft were randomized into a control group (no SNB) and an intervention group (SNB). All patients received standardized anesthetic induction and maintenance agents with perioperative analgesia, per study protocol, with local anesthetic infiltration of the graft harvest site and intra-articular infiltration. RESULTS: Sixty patients were randomized into the 2 groups (n = 30 each). There was no statistically significant difference in total opiate consumption between the groups (control, 34 mg; SNB, 31 mg; P = .40). There was no statistically significant difference in visual analog scale scores for pain at 0, 8, and 24 hours postsurgery, and no difference in overall satisfaction score. The control group had a significantly higher visual analog scale score at 4 hours postsurgery (3.0 vs 1.9, P = .04). CONCLUSION: SNB has a minimal effect on postsurgical care for ACL reconstruction with hamstring autograft in the presence of multimodal analgesia and local anesthetic infiltration.

Surgical inclination and anatomy teaching at the University of Auckland.

BACKGROUND: Medical graduate interest in surgery has declined and medical students are less capable in anatomy than they once were. Declining interest in surgery is because of factors, including growing number of women entering medical school. There has been less emphasis in teaching anatomy at various medical schools in recent years. The aim of this study is to quantify surgical inclination in Auckland medical students to assess whether gender differences exist in surgical inclination and determine confidence in anatomy knowledge and resources used by Auckland medical students. METHOD: Survey design was cross-sectional and included 25-point questionnaire using Likert scale response ranking and tick box replies. Two hundred and eighteen surveys were emailed to functioning addresses of fourth and fifth year students at University of Auckland, School of Medicine, New Zealand. RESULTS: Response rate was 71.6%. Twenty per cent of students were found to be surgically inclined (95% confidence interval, 0.15-0.26). The proportion of surgically inclined men was significantly higher than women (P < 0.05). Thirty-three per cent of all respondents (95% confidence interval, 0.26-0.41) felt their knowledge of anatomy was adequate to practice medicine safely. Textbooks and atlases were most commonly used to learn anatomy (P < 0.05). Radiology was the least commonly used method to learn anatomy (P < 0.05). Eighty-seven per cent (95% confidence interval, 0.81-0.92) of respondents agreed that revisiting dissection during surgical attachments would be helpful. CONCLUSION: Men are significantly more likely to be surgically inclined than women at the University of Auckland. A significantly greater proportion of students felt that their knowledge of gross anatomy was inadequate for safe medical practice. Students use traditional methods to learn anatomy more commonly than radiological methods. The majority of students surveyed would like to revisit cadaver dissection during clinical attachments in surgery.

Is radiograph glenopolar angle accurate for extraarticular scapular neck fractures?

BACKGROUND: Plain radiographs still play a role in management of extraarticular scapular neck fractures. Glenopolar angle (GPA) is one of the radiograph measurements that is used to determine the necessity for surgery. Our aim was to establish reliability of GPA on plain radiograph in patients with extraarticular scapular neck fractures. METHODS: We performed a multicentre retrospective study including all patients with extraarticular scapular neck fractures with available imaging between 2006 and 2012. We excluded intra-articular glenoid fractures, scapular blade fractures, acromion fractures, and scapular spine fractures. We compared GPA on plain radiograph with three dimensional computed tomography (3D CT) measurement, as well as contribution of radiograph rotational error, glenoid inclination, and medial shortening of glenoid fragment towards GPA measurement. RESULTS: One hundred patients met the inclusion criteria. The mean difference between the GPA measurements on radiographs and 3D CT was 6.1±0.85° (95% confidence interval) as an absolute value. In terms of contribution to GPA values, GPA changed by one degree with ten degrees of radiograph rotational error, three degrees of glenoid inclination, and three millimetres of glenoid fragment medial shortening. CONCLUSION: Plain radiograph can provide a clinician with a reasonable estimation of the GPA. Glenoid inclination has a greater influence on GPA compared to medial shortening.

Magnetic resonance imaging of the common bile duct to exclude choledocholithiasis.

BACKGROUND: Prior to cholecystectomy it is important to assess the common duct for choledocholithiasis. Given that a proportion of common duct stones will pass without incident and that methods of removal of these stones are potentially morbid, it would be very useful to have a test that identified only those stones that need intervention. The present study was designed to assess whether a negative magnetic resonance cholangiopancreaticogram (MRCP) is able to reliably exclude clinically relevant common duct stones. METHODS: A retrospective analysis on all patients with cholelithiasis, who underwent MRCP, between November 2001 and May 2003, for suspected choledocholithiasis, was performed. Patients were considered to have no clinically relevant choledocholithiasis if they had a negative MRCP for choledocholithiasis, and were not readmitted to the hospital with complications of choledocholithiasis within a minimum of 3 months after treatment for their cholelithiasis. RESULTS: The MRCP was negative for choledocholithiasis in 74% of patients (60/81). The MRCP missed clinically relevant choledocholithiasis in only two patients, and had a positive predictive value of 0.95 and a negative predictive value of 0.97 for choledocholithiasis. CONCLUSION: In patients with strong indications for choledocholithiasis MRCP is able to reliably exclude clinically relevant choledocholithiasis and is therefore recommended as the preoperative diagnostic imaging tool of choice.

Time to definitive care for patients with moderate and severe traumatic brain injury--does a trauma system matter?

AIM: The presence of a trauma system has been associated with improved outcomes in patients with traumatic brain injury (TBI) by speeding up transfers to a neurosurgical centre. Improved outcomes are associated with time to neurosurgical intervention for those with significant extradural and subdural haemorrhages of less than 4 hours. To compare the outcomes for patients with TBI transferred directly from the scene of injury to Auckland City Hospital (ACH) with those transferred from other hospitals, transfer times and outcomes were evaluated in a consecutive cohort of patients recorded on the ACH trauma registry. METHOD: Patients admitted to ACH in 2004 and recorded on the trauma registry with a moderate or severe head injury (Abbreviated Injury Scale (AIS) score of 3 or greater) were included. The primary outcomes assessed were median time from injury to arrival and surgery, patient mortality, length of ICU stay and length of hospital stay. RESULTS: 198 patients were admitted at ACH in 2004 with moderate and severe TBI. 95 patients (48%) were transferred from another hospital. Patients transported to ACH from the scene of injury arrived to ACH and underwent neurosurgery within a mean of 3 hours 50 minutes, whereas patients transferred from another hospital took significantly longer than 4 hours to arrive at ACH. Patients transferred from another hospital had similar mortality rate, length of ICU stay and length of hospital stay to those admitted directly. CONCLUSION: TBI patients who were transferred from another hospital arrived well outside the recommended guidelines. While no significant difference in outcome was noted in this small cohort of patients further studies are warranted. The development of a national trauma registry would allow accumulation of data on larger numbers of patients and determine the true relevance of international best practice guidelines in New Zealand.

Is it possible to distribute a scarce resource equitably? Access to invasive procedures for patients with acute myocardial infarction.

AIMS: To compare waiting times for inpatient cardiac catheterisation between a hospital with on-site cardiac catheterisation facility (Auckland City Hospital, ACH) and one of its referring hospitals (North Shore Hospital, NSH). METHODS: Patients were included if they were admitted ACH or NSH with a myocardial infarction, and subsequently underwent inpatient coronary angiography. RESULTS: 853 patients were identified from NSH and 600 from ACH. Patients from NSH waited significantly longer for coronary angiography (median delay 6 versus 3 days, p<0.0009) and fewer underwent this procedure within 48 hours of admission (11% versus 36%, p<0.0009). Delays in percutaneous coronary intervention were significantly longer for NSH patients (6 versus 3 days, p<0.0009), and fewer NSH patients underwent this procedure within 48 hours (12% versus 41%, p<0.0009). CONCLUSIONS: Inpatients with myocardial infarction waited longer for coronary angiography and percutaneous coronary intervention at a hospital without invasive facility than similar patients at the regional referral hospital with on-site invasive facility.

Surgical inclination in senior medical students from the University of Auckland: results of the 2005 Senior Students Survey.

AIMS: To determine the proportion of senior medical students who are surgically inclined and to assess whether gender differences exist in surgical inclination. STUDY DESIGN: Cross-sectional survey. Twenty-five point questionnaire. Likert scale response ranking. SETTING: University of Auckland Medical School, New Zealand. PARTICIPANTS: 218 surveys were emailed to functioning addresses of fourth and fifth year students.156 students emailed responses (71.60% response rate). RESULTS: Twenty percent of students were found to be surgically inclined (95% CI 0.15-0.26). The proportion of surgically inclined males was significantly higher than females (p<0.01). A greater proportion of surgically inclined students found time spent in the operating theatre educationally valuable than non-surgically inclined students (p<0.01). No difference exists in the number of different procedures undertaken by students (p<0.05). CONCLUSION: Males are significantly more likely to be surgically inclined than females at the University of Auckland Medical School.