Clinical outcomes after using patient specific instrumentation: is it worth the effort? A minimum 5-year retrospective review of 298 PSI knees.

INTRODUCTION: Use of patient specific instrumentation (PSI) for performing total knee arthroplasty (TKA) has been shown to improve component positioning but there is dearth of evidence regarding clinical outcomes. The aim of our study was to report patient satisfaction and functional outcome scores of patients who underwent PSI TKAs at minimum 5 year follow up. METHODS: This is a retrospective study of a prospectively collected data of patients who underwent PSI TKAs between January 2012 and October 2015 under a single surgeon. Patient Reported Outcome Measures (PROMs), patient satisfaction questionnaires, surgeon directed 3D planning changes and intra-operative changes were collected and analysed. RESULTS: The cohort included 298 consecutive PSI TKAs performed on 249 patients at a mean age of 71 years (range: 49-93 years). On an average 4 changes were made for each knee during 3D planning compared to preliminary plan. Intra-operative implant size change was required only in 3% (10 knees). The PROM scores were collected at a mean follow-up period of 6.8 years (range: 5.0-8.6 years) for 224 knees. Oxford Knee Score improved from median pre-operative score of 18 (IQR: 13-24) to median post-operative score of 44 (IQR: 40-47) with a median gain of 23 (IQR: 16-30). The median modified Forgotten Joint Score was 87.5 (IQR: 54.4-98.1). For the Beverland questionnaire, 75% (n = 166) reported being "Very Happy" and only 4% (n = 9/222) were 'Never Happy'. CONCLUSION: Excellent patient satisfaction and functional scores at mid-term can be achieve d using PSI technique to perform TKA with careful surgeon directed pre-operative planning.

Postural balance during quiet standing in patients with total hip arthroplasty with large diameter femoral head and surface replacement arthroplasty.

OBJECTIVE: To compare postural balance between patients who have had either a large diameter head total hip arthroplasty or surface replacement arthroplasty. DESIGN: Observational study. SETTING: Outpatient biomechanical laboratory. PARTICIPANTS: Two groups of 14 patients with surface replacement or large diameter head total hip arthroplasties recruited from a larger randomized study and 14 control subjects. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Postural balance during quiet standing in dual and one-leg stance (operated leg), hip abductor muscle strength, clinical outcomes, and radiographic analyses were compared between groups. RESULTS: Compared to the control group, patients in both groups showed smaller center of pressure displacement amplitude in the medial-lateral direction in dual stance. Patients with large diameter head total hip arthroplasty showed lower hip abductor muscle strength compared to control subjects. There was statistical difference between the 2 patient groups in biomechanical reconstruction of the hip. Despite these differences, there was no significant difference in the ability to complete the one-leg stance task between the 3 groups. CONCLUSIONS: The muscular strength in the operated limb could be mainly responsible for the lower center of pressure displacement amplitude compared to control subjects. However, the ability to complete the one-leg stance demonstrates that patients do not fear to load the hip prosthesis when needed. The large diameter femoral head may be a major mechanical factor contributing to these results.

Femoral component positioning in hip resurfacing with and without navigation.

UNLABELLED: Early failures after hip resurfacing often are the result of technical errors in placing the femoral component. We asked whether image-free computer navigation decreased the number of outliers compared with the conventional nonnavigated technique. We retrospectively compared 51 consecutive hip resurfacings performed using image-free computer navigation with 88 consecutive hip resurfacings performed without navigation. Patient demographics were similar. There were no differences in the average native femoral neck-shaft angles, planned stem-shaft angles, or postoperative stem-shaft angles. However, when the postoperative stem-shaft angle was compared with the planned stem-shaft angle, there were 33 patients (38%) in the nonnavigated group with a deviation greater than 5 degrees in contrast to none in the navigated group. Notching was present in four patients in the nonnavigated group and none in the navigated group. The average operative time was 111 minutes for the navigated group and 105 minutes for the nonnavigated group. Image-free navigation decreased the number of patients with potentially undesirable implant placements. LEVEL OF EVIDENCE: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Heterotopic ossification after surface replacement arthroplasty and total hip arthroplasty: a randomized study.

With a randomized clinical trial, we compared the incidence and severity of heterotopic ossification in cohorts of patients who have undergone either surface replacement arthroplasty or total hip arthroplasty at a minimum follow-up of 1 year. Surface replacement arthroplasty group had a significantly higher rate of severe heterotopic ossification (Brooker grades 3-4) than the total hip arthroplasty group, 12.6% (13/103) vs 2.1% (2/97) respectively (P = .02). Grade 4 heterotopic ossification was observed (4.9%, 5/103) exclusively in the surface replacement arthroplasty group. Patients with severe heterotopic ossification had significantly inferior functional outcome scores. Surgeons offering surface replacement must be aware of this risk and use meticulous surgical technique and consider routine prophylaxis against heterotopic ossification.

Factors affecting acetabular bone loss during primary hip arthroplasty--a quantitative analysis using computer simulation.

BACKGROUND: Although, various factors may affect the degree of acetabular bone loss during primary hip arthroplasty, they have not been quantified previously. METHODS: We assessed the influence of using various reamer diameters, designs and reaming depth on the amount of bone removed during acetabular preparation by simulated reaming in a three-dimensional pelvic model, using computer software. FINDINGS: The least amount of bone loss (6185 mm3) providing optimal bone contact with the acetabular articular surface occurred with a 165 degrees reamer design. Increase in reamer diameter, reaming depth and subtending angle of the reamer resulted in disproportionately large increase in the amount of bone resected compared to the relatively small increase in the reamer-bone contact area. INTERPRETATION: Surgeons must be aware of the relative influence of the reaming technique and the implant design on the amount of acetabular bone resection to optimize acetabular bone preservation during primary hip arthroplasty.

Factors affecting hip range of motion in surface replacement arthroplasty.

BACKGROUND: Surface replacement arthroplasty aims to re-create normal hip biomechanics; however the pathoanathomy of the hip, prosthetic component design, surgical technique and other factors may have a significant impact on the range of motion restoration attained following surface replacement arthroplasty. However, there is paucity of information on the effect of such factors. METHODS: A computerized three-dimensional hip model was created from preoperative computerized tomography images of a patient who was scheduled for a surface replacement arthroplasty. The effects of the femoral component size, translation and orientation on the range of motion were analysed as was the effect of increasing the seating depth and modification of the version of the acetabular component. FINDINGS: Increasing the femoral component size led to global improvement in range of motion while translation increased range of motion in one direction but reduced it in the opposite direction. Change in the femoral component orientation had minimal effects on range of motion in comparison to the effect of changes in the version of the acetabular component. Increasing the seating depth of the acetabulum only caused reduced range of motion in internal rotation in 90 degrees flexion. INTERPRETATION: To restore hip range of motion, surgeons performing surface replacement arthroplasty should aim to reproduce the natural femoral head-neck offset. Although increasing the femoral component size may achieve this, more acetabular bone will be resected. Knowing the specific zones of impingement of each arc of movement, selective translation of the femoral component or femoral neck osteoplasty can restore femoral neck offset in more critical areas without affecting acetabular bone stock. Over deepening of the acetabulum or leaving rim osteophytes should also be avoided to prevent impingement.

Sexual activity and total hip arthroplasty: a survey of patients' and surgeons' perspectives.

It is not clear if regaining sexual activity is important for patients undergoing total hip arthroplasty (THA) or whether hip surgeons are aware of and manage the concerns of their patients in this context. A questionnaire survey was conducted on 100 patients undergoing THA immediately before and six months after surgery. All members of the British Hip Society with a valid email address were surveyed. 86 patients responded. 71 were sexually active and of these, 55 (77%) believed their hip pathology had been limiting their sex lives. 39 (55%) would have preferred further information than was provided. 51 (72%) patients had recommenced sexual activity by six months post operation. 83 of 140 surgeons responded. 30 (36%) surgeons enquired preoperatively if symptoms were interfering with patients' sex lives and 32 (39%) provided written information about sexual activity following THA. 55 (66%) surgeons believed four weeks after surgery patients could resume sexual activity but only 21 (25%) surgeons regularly advised patients about an appropriate time to resume sexual activity. Sexual activity is adversely affected in many patients awaiting THA and regaining sexual function is important to these patients. Most surgeons do not discuss this with their patients and may not be aware of their patients' expectations in this respect.

Residual groin pain at a minimum of two years after metal-on-metal THA with a twenty-eight-millimeter femoral head, THA with a large-diameter femoral head, and hip resurfacing.

BACKGROUND: Groin pain may persist in up to 4.3% of patients after total hip arthroplasty and up to 18% of patients one year after hip resurfacing. The incidence of this problem after total hip arthroplasty with a large-diameter femoral head is unknown. METHODS: We analyzed the natural history of groin pain and its clinical consequences during the first two years after three types of hip arthroplasty. Data were collected prospectively on 279 patients. Eighty-five patients had a polyethylene sandwich metal-on-metal total hip arthroplasty with a 28-mm-diameter femoral head, 105 had hip resurfacing, and eighty-nine had a total hip arthroplasty with a large-diameter femoral head component with three other cup designs (forty-nine in this group had the same monoblock acetabular cup design as those who had hip resurfacing). RESULTS: At the twenty-four-month follow-up evaluation, seventy-seven patients (28%) reported at least one painful area around the hip and thirty-four patients (12.2%) had pain at more than one location. At three months, the incidence of groin discomfort was significantly increased in those who had hip resurfacing (30.5%) and in those who had total hip arthroplasty with a large-diameter femoral head (30%) compared with those who had total hip arthroplasty with a 28-mm femoral head (18.3%). This incidence decreased at two years (14.9%, 16.9%, and 12.9%, respectively). At twenty-four months postoperatively, eleven (four who had hip resurfacing, six who had total hip arthroplasty with the large-diameter head, and one who had total hip arthroplasty with the 28-mm head) of forty-one patients who had groin pain had not reported groin pain at previous follow-up evaluations. Of the forty-one patients reporting groin pain at the time of the last follow-up, twenty-three patients (56%) did not seek further evaluation or treatment, nine had revision surgery (22%), and the remaining nine patients thought the pain was substantial enough to warrant further evaluation and treatment. CONCLUSIONS: When the exact source of groin pain cannot be found after total hip arthroplasty, careful follow-up should be done as local reactions to metal-on-metal implants and component loosening may take time to become apparent clinically or on imaging studies.

Range of motion of large head total hip arthroplasty is greater than 28 mm total hip arthroplasty or hip resurfacing.

BACKGROUND: Reduced range of motion of the hip has a detrimental influence on lower limb function. Large diameter head total hip arthroplasty may theoretically have a greater potential for restoring normal hip range of motion due to greater head-neck diameter ratio, and hence provide better function compared to conventional or hip resurfacing arthroplasty. METHOD: At minimum one year follow-up, range of motion of the operated and contra lateral hips was clinically assessed using digital photographs and bony landmarks in a clinical comparative study. We assessed if 1) large diameter head total hip arthroplasty (55 patients) restores better hip range of motion compared to 28 mm total hip arthroplasty (50 patients) or hip resurfacing (60 patients) 2) large diameter head total hip arthroplasty achieves same hip range of motion as contra lateral normal hips and 3) hip range of motion correlates with the WOMAC score. FINDINGS: The large diameter head total hip arthroplasty group had significantly greater total arcs of motion (approximately 20°), mostly due to an increase of hip flexion and external rotation, but did not reach normal hip motion. The hip range of motion showed significant correlation with the WOMAC score, especially the flexion arc. INTERPRETATION: The better hip range of motion of large diameter head total hip arthroplasty is likely due to the greater head to neck diameter ratio and hence seems to be the best option to optimize range of hip motion and improve function after hip arthroplasty.

A comparison of clinical results of hip resurfacing arthroplasty and 28 mm metal on metal total hip arthroplasty: a randomised trial with 3-6 years follow-up.

Two hundred and nine hips were randomised to receive either a 28 mm total hip athroplasty (THA, 100 hips) or hybrid hip resurfacing (HR, 109 hips). At 1 and 2 years post-operatively, patients with HR achieved statistically significantly better WOMAC functional scores. However, differences in scores were of slight clinical relevance with a difference of 2.2/100 and 3.3/100, at 1 and 2 years respectively (p=0.007). After an average follow-up of 56 months (range 36-72) there were similar re-operation rates 7/100 THA and 6/109 HR (p=0.655) and revision rates 2/100 THA and 4/109 HR (p=0.470). However, the types of complications were different. Higher early aseptic loosening rate was found in HR and long-term survival analysis of both patient cohorts is necessary to determine whether the potential bone preservation advantage offers by HR will overcome its earlier higher failure rate.

Missed diagnosis of ankle pseudoaneurysm following ankle arthroscopy: a case report.

BACKGROUND: Pseudoaneurysm formation is rare complication after arthroscopy with incidence of 0.008%, easy to misdiagnose. Its potential catastrophic sequelae should not be underestimated. CASE PRESENTATION: We present a case of missed diagnosis of traumatic anterior tibial artery pseudoaneurysm in a 39 years old female, instead treated as post operative arthroscopy infection. The diagnosis was confirmed with a duplex ultrasound scan and referred to the vascular surgeon with successful out come. CONCLUSION: In view of rare presentation this complication, it is easily missed. According to one study, incidence of anatomic variations of anterior tibial artery range from 2.4 to 12%. Because of this anatomical variation in course along with other factors, pseudoaneurysm formation at ankle is relatively high. In this report, we discuss the diagnosis, anatomical variations of anterior tibial artery and prevention of this complication following arthroscopy. We believe that surgeons operating in this region should take into account these anatomical variations preoperatively.