Abstract. BACKGROUND. Hemi-arthroplasty (HA) as a treatment for fractured neck of femur has slightly increased since 2019 and remarkably after the COVID pandemic. The main drawback of the treatment is ongoing cartilage deterioration that may require revision to THR. OBJECTIVE. This study assessed cartilage surface damage in hip HA by reproducing anatomical motion and loading conditions in a hip simulator. METHODS. Experimental design. HA tests were conducted using porcine acetabula and CoCr femoral heads. Five groups (n=4) were included: a control group comprising natural tissue and four HA groups where the acetabula were paired with metal heads to allow radial clearance (RC) classed as small (RC<0.6mm), large (2mm<RC<4mm), extra-large (4mm<RC), and oversized (RC<−0.6mm). Tests were carried out in an anatomical hip simulator that reproduced a simplified twin peak gait cycle, adapted for porcine hip joints, from the ISO 14242 standard for wear of THR prostheses (peak load of 900N). The test length was 6 hours, with photogrammetry taken at 1-hour intervals. Ringers solution was used as a lubricant. RESULTS. No changes were observed in the control group. However, cartilage surface changes were observed in all hemi-arthroplasty groups. Discolouration on the cartilage surface was noticeable at the posterior-superior part of the acetabulum after 1-hour (extra-large and oversized groups). Damage severity and location were characteristic of each clearance group. Of all the groups, the oversized group showed more significant damage. No labrum separation was seen after the simulation. CONCLUSIONS. These results are relevant to understand the effect of femoral head clearance on cartilage damage risk after HA. Declaration of Interest. (a) fully declare any financial or other potential conflict of interest

The surgical treatment options for patients who have sustained an intra-capsular hip fracture can vary depending on a number of patient and fracture related factors. Currently most national guidelines support the use of cemented prostheses for patient undergoing hemi-arthroplasty surgery. Uncemented prostheses are commonly used for a variety of indications including those patients who have significant medical co-morbidities. To determine whether cemented hemi-arthroplasty is associated with a higher post operative mortality when compared to uncemented procedures. Data was extracted from the Scottish SMR01 database from 01/04/1997 from all patients who were admitted to hospital after sustaining a hip fracture. We investigated mortality at day 1, 2, 4, 7, 30, 120 and 1 year from surgery vs. that on day 0. In order to control for the effects of confounding variables between patients cohorts, 12 case-mix variable were used to construct a multivariable logistic regression analysis model to determine the independent effect of prosthesis fixation method. There were 64,979 patients were included in the study. Mortality for osteosynthesis of extra-capsular fractures was consistently lower when compared to that for surgical procedures for intra-capsular fractures. At day 0, uncemented hemi-arthroplasty operations had a lower associated mortality (p<0.001) when compared to cemented implant designs. Unadjusted figures showed an increased mortality equal to 1 extra death per 424 procedures. By day 1 this had become 1 extra death per 338 procedures. By day 7 cumulative mortality was less for cemented than for uncemented procedures though this did not reach significance until day 120. When compared to uncemented fixation techniques, cemented hemiarthroplasty is associated with a higher mortality in the immediate postoperative period. However, by day 120 and beyond the trend is reversed

Summary Statement. Total hip arthroplasty and hemi-arthroplasty are becoming increasingly popular in the treatment of femoral neck fractures in the United States. Both appear to be safe and effective treatment options, with rare acute adverse events and low mortality. Introduction. Femoral neck fractures are one of the most frequent orthopaedic injuries seen in the United States (US). Total hip arthroplasty (THA) and hemiarthroplasty (HA) are commonly used to treat displaced intra-capsular femoral neck fractures, but controversy currently exists regarding the preferred modality. The purpose of this study was to assess recent national trends in THA and HA performed for femoral neck fracture and to evaluate perioperative outcomes for each treatment group. Methods. International Classification of Disease - 9th Revision (ICD-9) diagnosis codes were used to search the National Hospital Discharge Survey (NHDS) for all patients admitted to US hospitals after femoral neck fracture for each year between 2001 and 2010. ICD-9 procedure codes were then used to identify patients from this fracture population who underwent THA or HA. Data regarding patient demographics, hospitalization length, discharge disposition, in-hospital adverse events (pulmonary embolus, deep vein thrombosis, blood transfusion, mortality) and hospital size/location were gathered from the NHDS. Trends were evaluated by linear regression with Pearson's correlation coefficient (r) and statistical comparisons were made using Student's t-test, z-test for proportions, and chi-square analysis with a significance level of 0.05. Results. 12,757 patients with a femoral neck fracture were identified. 582 (4.6%) were treated with THA and 6,697 (52.5%) received HA. After adjusting for fluctuations in annual fracture incidence, the use of THA to treat femoral neck fractures demonstrated a strong positive correlation with time (r=0.91), significantly increasing from an average rate of 4.2% between 2001–2005 to 5.0% between 2006–2010 (p=0.04). Similarly, the use of HA demonstrated a strong positive correlation with time (r=0.89) and significantly increased from an average rate of 51.0% to 54.7% (p<0.01). The frequency of THA use also demonstrated significant (p=0.01) differences based on US region, with a rate of 3.3% in the West region and 5.2% in the South. No regional differences were seen for HA (p=0.07). Hospital size significantly impacted HA use, with the lowest rate seen in hospitals under 100 beds (47.4%) and the highest rate in those with 200–299 beds (56.0%, p<0.01). No size differences were seen for THA (p=0.10). The THA group had a mean patient age of 76.9 years and included 164 men and 418 women. The HA group had a mean patient age that was significantly higher at 81.1 years (p<0.01) and included 1744 men and 4953 women. Gender was not significantly different (p=0.27) between the groups. Average hospitalization length was significantly longer for THA (7.8 days, range 1–312) compared to HA (6.7 days, range 1–118, p<0.01). Discharge disposition also varied by treatment group, with 23.2% of THA patients able to go directly home compared to only 11.6% of HA patients (p<0.01). Blood transfusion rate was significantly higher for THA (30.4%) compared to HA (25.7%, p=0.02). No significant difference was noted between THA and HA in regards to rate of PE (0.5% versus 0.7%, p=0.52), rate of DVT (1.2% versus 0.8%, p=0.50) or mortality (1.8% versus 2.9%, p=0.09). Discussion/Conclusion. This study demonstrates that the use of THA and HA in the treatment of femoral neck fractures are rising and that both are safe and effective treatment options, with equally rare acute adverse events and low mortality. Interestingly, treatment choice demonstrated variability based on hospital region and size. The reasons for this are not immediately clear, but may be related to differences in regional training and availability of trauma/reconstruction subspecialists

This study compared the effect of a computer-assisted and a traditional surgical technique on the kinematics of the glenohumeral joint during passive abduction after hemiarthroplasty of the shoulder for the treatment of fractures. We used seven pairs of fresh-frozen cadaver shoulders to create simulated four-part fractures of the proximal humerus, which were then reconstructed with hemiarthroplasty and reattachment of the tuberosities. The specimens were randomised, so that one from each pair was repaired using the computer-assisted technique, whereas a traditional hemiarthroplasty without navigation was performed in the contralateral shoulder. Kinematic data were obtained using an electromagnetic tracking device.

The traditional technique resulted in posterior and inferior translation of the humeral head. No statistical differences were observed before or after computer-assisted surgery.

Although it requires further improvement, the computer-assisted approach appears to allow glenohumeral kinematics to more closely replicate those of the native joint, potentially improving the function of the shoulder and extending the longevity of the prosthesis.