Preoperative Templating for Total Hip Arthroplasty: A Method for Calibrating Digital Radiographs Using Patient Demographics and Anthropometric Measurements.

Background Preoperative templating aids the surgeon in estimating implant size and placement. Calibration markers are used to set the correct magnification of digital images before templating. Improper marker placement or complete absence can lead to inaccuracy or an inability to calibrate images altogether. Aims This study describes a method for calibrating images using a patient's femoral head size (FHS) predicted using demographics and anthropometric data. Materials and methods A formula predicting the FHS was derived from a cohort of 507 patients who underwent hemiarthroplasty for an intracapsular fractured neck of the femur through multivariate regression analysis. A separate validation cohort (n=50) who had undergone total hip arthroplasty (THA) had postoperative radiographs calibrated using the predicted FHS and the native contralateral hip as a surrogate calibration marker. The THA femoral head implant size was subsequently measured and compared with the actual implant size selected intraoperatively. Measurements were performed by two independent assessors to determine intra- and interobserver reliability. Results Multivariate regression analyses showed four variables significantly correlated with the size of the femoral head: gender (p < 0.001), height (p < 0.001), weight (p < 0.001), and race (Asian) (p = 0.01). Using these, a regression model to predict the FHS was obtained with an R2 value of 0.65 and a standard error of 2.18 mm. The validation cohort showed that THA head implant size could be accurately measured with an average root-mean-squared error (RMSE) of 1.41 mm (SD = 0.97 mm; %RMSE = 4.7%). The implant head size was measured to be within 5%, 10%, and 15% RMSE in 57.5%, 93.0%, and 100.0% of cases, respectively. There was excellent intraobserver (R2 = 0.94 and 0.95) and interobserver (R2 = 0.94) reliability. Conclusions The novel method proposed and validated in this study, using a predicted FHS to calibrate digital images, provides an alternative means of templating THA for fractured neck of the femur patients, in whom external calibration markers are often absent.

How Accurate is the Use of Contralateral Implant Size as a Template in Bilateral Hemiarthroplasty?

PURPOSE: Accurately predicting implant size for hemiarthroplasties offers an important contribution to theatre efficiency and patients' intraoperative care. However, pre-operative sizing using templating of implants in hip fracture patients requiring a hemiarthroplasty is often difficult due to non-standard radiographs, absence of a calibration marker, poor marker placement, variable patient position, and in many institutions a lack of templating facilities. In patients who have previously undergone a hemiarthroplasty on the contralateral side, surgeons can use the contralateral implant size for pre-operative planning purposes. However, the accuracy of doing this has not previously been reported. The aim of this study was to investigate the reliability of using an in situ contralateral implant as a predictor of implant size on the contralateral side. METHODS: A retrospective review of our local neck of femur fracture (NOF) database was undertaken to identify patients who had bilateral hip hemiarthroplasty. Operative records were reviewed to establish the size of prostheses used at operation. Correlation, agreement, and reliability analysis were performed using the least squares, Bland-Altman plot, and intra-class correlation coefficient (ICC) methods, respectively. RESULTS: Operative records were identified for 45 patients who had bilateral hemiarthroplasties. There was a difference in implant size used in 58% of cases. Of these 77% required a larger implant on the right. Implant sizes were within 1 mm of the contralateral side in 78% and within 2 mm in 91% of patients. However, in 9% of patients, there was a discrepancy greater than 2 mm with some cases having up to 6 mm discrepancy. Correlation coefficient was 0.83 and the ICC 0.90. CONCLUSIONS: The findings in this study indicated that using the size of a contralateral implant can be used as a reliable indicator of head size in cases of bilateral hemiarthroplasty. However, the surgeon should remain cautious as there is a one in ten chance of there being a 3 mm or more difference in implant size.

There is no 'weekend effect' in elective orthopaedic surgery.

Introduction The 'weekend effect' is said to occur when patient outcomes are adversely affected by the day of the week on which they present to hospital or have surgery. However, it is uncertain whether such a phenomenon exists for elective orthopaedic surgery. We investigated whether there is a 'weekend effect' in elective orthopaedic patients. Methods Retrospectively collected data were obtained from our institution's electronic patient records. We collected demographic and International Statistical Classification of Diseases and Related Health Problems tenth revision coding data for all included patients. Multivariate analyses identified covariate-adjusted risk factors, associated with prolonged stays. Thirty-day mortality data were assessed according to the day on which surgery occurred. Results We analysed data for 892 patients over a one-year period. During the year, 457 patients had a total hip and 435 had a total knee replacement; 814 patients (91.3%) underwent surgery during the week, while 78 (8.7%) had surgery on a Saturday. There was no difference in average length of stay between the groups (5.0, 2.6 vs 5.0, 3.4, P = 0.95). Variables associated with prolonged hospitalisation included increasing age (covariate adjusted relative risk 1.02, 95% confidence interval 1.01-1.03, P < 0.001) and an American Society of Anesthesiologists score of 2, (relative risk 1.6, 95% confidence interval 1.15-2.20, P = 0.005). There was one death in a patient who underwent surgery on a Monday. Conclusions There is no 'weekend effect' for elective orthopaedic surgery.

Outcome of the Stryker® Trident 'All-Poly' constraint acetabular insert: a district general hospital experience.

INTRODUCTION: Constrained acetabular inserts are designed as revision solutions for unstable total hip arthroplasties to prevent dislocation and as a possible primary option for elderly patients at risk of recurrent dislocation. PURPOSE: Our aim was to establish clinical and radiological outcomes of an 'all-poly' constrained acetabular device and to highlight reasons for component failure. METHODS: We retrospectively reviewed our use of the Stryker® Trident 'all-poly' constrained acetabular insert between 2008 and 2013. All inserts were cemented directly into the acetabulum. Demographic data was collated. The indication for use of a constrained insert and postoperative complications were determined. Patients were reviewed clinically and underwent radiographic follow-up. RESULTS: A total of 56 constrained inserts were utilised during the study period. Follow-up was for a minimum of 2 years (mean 4.0 years and range 2.0-6.8 years). The mean latest follow-up Oxford hip score was 34.6 (11-48). One postoperative superficial wound infection, 1 breakage of the constraining ring without clinical consequence and 1 recognised complication of liner failure at the bipolar interface were noted. CONCLUSIONS: In the short to medium term, acetabular constraint offers a useful primary or revision option in patients at risk or with recurrent dislocation.

A minimally invasive surgical technique for augmented reconstruction of the lateral ankle ligaments with woven polyester tape.

Although stabilization of the lateral ankle ligament complex (LALC) with augmented techniques is known to be successful, it is associated with a number of complications. We hypothesize that successful stabilization of LALC can be achieved with a woven polyester tape implant via a minimally invasive procedure, as an alternative to tenodesis. Four men with chronic instability of the ankle underwent a minimally invasive surgical stabilization of LALC with a woven polyester tape. This tape was passed through the distal fibula to the base of the fifth metatarsal and then back to the fibula once more before being tied. The foot was immobilized in a neutral position for 2 weeks. Partial weightbearing with a walking stick began on the same day, and physiotherapy began for 10 weeks. Evaluation was performed at a mean follow-up of 24.5 months postoperatively. Preoperatively, all patients had a chronically unstable index ankle both functionally and clinically. At a mean of 24.5 months postoperatively, functional stability for all patients was normal (Sefton grade 1). Subjective ankle performance grades were normal in all cases, and all patients felt the outcome was excellent. Objective measurement with clinical stress testing showed anterior drawer and inversion tests to be the same as the contralateral ankle in all patients. However, each displayed limited inversion of the ankle. No complications such as wound dehiscence, infection, pain, or nerve injury were observed after the procedure. All were able to return to their preinjury activity level within 3 months. Stabilization of LALC may be simply and successfully achieved with a woven polyester graft as an alternative to tenodesis.

Long-term clinical review (10-20 years) after reconstruction of the anterior cruciate ligament using the Leeds-Keio synthetic ligament.

Prosthetic ligament use for anterior cruciate ligament (ACL) reconstruction was popular in the 1980s and 1990s. Information from published studies regarding the long-term outcomes of this surgery is limited. This paper presents the long-term results of stabilization of the ACL deficient knee using the Leeds-Keio synthetic ligament formed from woven polyester. Fifty patients were seen in clinic at a mean follow-up of 11.9 years (range 8.7-19.7 years). The mean ages were: at injury 26.8 years (range 16-47 years), at surgery 29.9 years (range 18-47 years), and at review 42 years (30-56 years). Of the 50 patients included, 86% were male and 14% were female. The main causes of injury were football (42%), rugby (25%), and skiing (8%). The mean time from injury to surgery was 37.6 months (range 0-324 months). All patients received intra-articular (IA) ligaments placed in the anatomical position of the natural ACL. In addition, approximately 75% also had an extra-articular ligament placed so that it ran parallel to the IA component on the lateral aspect of the knee. At review, patients were thoroughly assessed with history, examination, and IKDC criteria. IKDC scores were excellent or good in 92% of patients seen while combined IKDC and thorough clinical history findings were good or excellent in 84% of patients seen. Patient satisfaction was high with 90% of patients being satisfied or very satisfied with the outcome of surgery. Activity levels were also high according to IKDC criteria. At one year postoperatively, approximately 66% of patients had returned to their preinjury level of activity. At review, almost half of all patients still maintained this level. Of those patients who did not, only 6% attributed this to knee instability. Furthermore, the vast majority of patients (92%) still had activity levels superior to that of postinjury/preoperatively. Rupture of the intra-articular component was confirmed in six cases (12%) and three of these patients continued to experience functional knee instability. These results demonstrate that synthetic ligament can provide long-term functional stability in the knee following a loss of the ACL.

Partial rupture of the distal semitendinosus tendon treated by tenotomy--a previously undescribed entity.

Hamstring strains are common. They are usually treated conservatively, with good results. Thus far, the only subset of patients who have been considered for surgery are those with complete avulsions of the attachments. We describe a new clinical entity: partial rupture of the distal semitendinosus tendon; which has failed to settle with conservative treatment; and has been successfully treated by tenotomy.

Systemic effects of bilateral tibial versus bilateral femoral shaft fractures. Is there a difference?

The authors investigated the prevalence and the difference in the severity of systemic complications following intramedullary nailing of bilateral tibial and femoral shaft fractures. A retrospective chart analysis of 12 consecutive patients with bilateral tibial shaft fractures (TF) and 14 patients with bilateral femoral shaft fractures (FF) was performed. The incidences of bilateral tibial fractures and bilateral femoral shaft fractures were 3.8% and 4.6% respectively. The median Injury Severity Score (ISS) in TF group was 13 (9-29) compared to 16 (9-34) in the FF group (p = 0.169). The mean resuscitation requirements were 4.2 (3-11) litres of colloids and crystalloids and 1.7 (0-10) units of blood in the TF group and 10.6 (6-16) litres of colloids and crystalloids and 9.2 (5-25) units of blood in the FF group (p = 0.002). In the TF group there was 1 death compared to 2 in the FF group. In the TF group, there were 2 cases of ARDS, 4 cases of deep sepsis and 3 above knee amputations. In the FF group, there were 6 cases of ARDS (p = 0.04), 1 case of deep sepsis and 1 above knee amputation. Patients with bilateral tibial shaft fractures revealed lower ISS, resuscitation requirements, ARDS, associated injuries, and mortality when compared to bilateral femoral shaft fractures. This is probably due to the anatomical difference in the morphology of the bones, volume of liberated intravascular marrow fat, organisation and layout of the venous capillary network and severity of associated injuries.