The survivorship of revision total hip replacement with severe proximal bone deficiency using a modular taper fluted prosthesis.

Contemporary uncemented femoral revision hip systems have become commonly used over the past decade and have enabled the reconstruction of leg length, offset and anteversion as independent variables through the use of modular junctions. Modular junction failures between the proximal body and distal stem have been described with revision systems, although this is rare. We sought to identify the survivorship of one revision system in a salvage arthroplasty scenario where no host bone support of the modular junction was present. From a series of 136 patients, 15 patients (16 hips) were identified without host bone support of the modular junction with a mean radiological follow up of over 6 years (76 months +/- 35 months). There have been no cases of prosthetic fracture over the follow-up duration, with two revisions performed for reasons of aseptic loosening and infection. The mean BMI of the study group was 30.2 with 78% of the cohort classified as overweight or obese. It is well recognised that, host bone support of the modular junction is preferable, however the satisfactory outcomes over the midterm in these complex patients suggests that modular revision systems remain an option.

Reliability analysis of radiologic and intraoperative loosening in total elbow arthroplasty.

BACKGROUND: Revisions of total elbow arthroplasties (TEAs) are commonly performed because of prosthetic loosening. UK National Joint Registry data show that TEA revisions are becoming increasingly common, with 123 TEA revisions performed in 2018 and 76 performed in 2017. TEA radiologic assessment is based on subjective interpretation with no published criteria. We defined TEA loosening by the presence of at least one of the following criteria: (1) progressive widening of the bone-cement, bone-prosthesis, or cement-prosthesis interface; (2) fragmentation or fracture of cement; (3) prosthetic component migration; and (4) bead shedding in porous-coated prostheses. Using this definition, we looked at interobserver and intraobserver agreement on radiologic loosening and compared this assessment with intraoperative findings. METHODS: In our tertiary care center, we conducted a retrospective review to identify TEA revisions performed between November 2008 and July 2018. Radiologic implant loosening was independently assessed by 5 orthopedic surgeons. Interobserver agreement (κ coefficient) was calculated. The majority's view of radiologic loosening was compared with intraoperative findings. RESULTS: We identified 93 sets of radiographs with implant stability clearly documented in their operative notes. The κ coefficient between assessors for humeral implant loosening was 0.87 (almost perfect). The κ coefficient for ulnar loosening was 0.75 (substantial). The κ coefficients for radiologic and intraoperative findings of humeral loosening and ulnar loosening were 0.67 and 0.71 (substantial), respectively. Intraobserver reliability was almost perfect for humeral loosening (κ = 0.86) and substantial for ulnar loosening (κ = 0.74). CONCLUSION: Our definition of loosening provides reproducible interobserver and intraobserver agreement on radiographic component loosening. In our center's experience, radiologic findings may not translate to intraoperative findings, and we would advise that surgical strategies for TEA revision include the possibility of needing to perform a dual-implant exchange.

Revision total elbow arthroplasty: Is it safe to perform a single-stage revision for presumed aseptic loosening based on clinical assessment, normal inflammatory markers, and a negative aspiration?

BACKGROUND: Revision total elbow arthroplasty (TEA) is a challenging procedure that is becoming increasingly common. In our unit, we regard it as essential to exclude infection as the underlying cause of TEA loosening. In all patients with arthroplasty loosening, we undertake a careful history and examination, perform radiographs, monitor inflammatory markers, and undertake a joint aspiration. If any investigation suggests infection as the etiology, then a 2-stage revision is undertaken. Open biopsies are not routinely performed. The aim was to ascertain from our outcomes whether it is safe to perform a single-stage revision for presumed aseptic loosening using these criteria. METHODS: A retrospective review of a consecutive series of revision TEAs was performed in our unit over a 10-year period (2008-2018). Single-stage revisions performed for presumed aseptic loosening were identified. Case notes, radiographs, bloods, aspiration results, and microbiology of tissue samples taken at revision were reviewed. RESULTS: A total of 123 revision elbow arthroplasty cases were performed in the study period. Sixty cases were revised for preoperatively proven infection, instability, or implant failure and were excluded from this study. In 63 cases, aseptic loosening was diagnosed based on history, clinical examination, blood markers, and aspiration. There were 21 dual-component and 42 single-component revisions. In the dual-component revision group, tissue samples taken at the time of revision were positive in only 1 case (5%). In the single-component revision group, positive culture samples were present in 3 cases (7%). χ2 analysis showed no significant difference between single- and dual-component revisions (P = .76). No cases with positive culture samples from either group have required subsequent revision surgery. CONCLUSION: Given the results of this study, we conclude that is safe to perform single-stage revision arthroplasty for implant loosening based on history, examination, normal inflammatory markers, and negative aspiration results without the need for open biopsy.

The Dimensionless Squared Jerk: An Objective Parameter That Improves Assessment of Hand Motion Analysis during Simulated Shoulder Arthroscopy.

PURPOSE: Attempts to quantify hand movements of surgeons during arthroscopic surgery faced limited progress beyond motion analysis of hands and/or instruments. Surrogate markers such as procedure time have been used. The dimensionless squared jerk (DSJ) is a measure of deliberate hand movements. This study tests the ability of DSJ to differentiate novice and expert surgeons (construct validity) whilst performing simulated arthroscopic shoulder surgical tasks. METHODS: Six residents (novice group) and six consultants (expert group) participated in this study. Participants performed three validated tasks sequentially under the same experimental setup (one performance). Each participant had ten performances assessed. Hand movements were recorded with optical tracking system. The DSJ, time taken, total path length, multiple measures of acceleration, and number of movements were recorded. RESULTS: There were significant differences between novices and experts when assessed using time, number of movements with average and minimal acceleration threshold, and DSJ. No significant differences were observed in maximum acceleration, total path length, and number of movements with 10m/s2 acceleration threshold. CONCLUSION: DSJ is an objective parameter that can differentiate novice and expert surgeons' simulated arthroscopic performances. We propose DSJ as an adjunct to more conventional parameters for arthroscopic surgery skills assessment.

Arthroscopic Skills Acquisition Tools: An Online Simulator for Arthroscopy Training.

PURPOSE: To evaluate correlations between objective performances measured by a new online arthroscopic skills acquisition tool (ASAT, in which "shape match" with inverted controls requires lifting shapes and releasing them into their corresponding silhouettes) and a validated virtual reality (VR) shoulder arthroscopy simulator (Insight Arthro VR; GMV, Madrid, Spain). METHODS: Forty-nine medical students familiarized themselves with 5 ASATs. They were then assessed using a sixth ASAT (shape match with inverted controls) and 4 VR tasks (operating room, visualize, locate and palpate, and pendulum) on the VR simulator. Correlations were assessed between 11 ASAT measures and 15 VR measures using Pearson correlation coefficients. RESULTS: Time taken and delta distance (actual distance minus minimum distance traveled) were the most frequent and correlated ASAT measures. Time taken correlated with the VR locate-and-palpate time (r = 0.596, P < .001), visualize time (r = 0.381, P = .007), and pendulum time (r = 0.646, P < .001), whereas delta distance correlated with the locate-and-palpate camera distance (r = 0.667, P < .001), instrument distance (r = 0.664, P < .001), visualize distance (r = 0.4, P = .004), pendulum camera distance (r = 0.538, P < .001), and instrument distance (r = 0.539, P < .001). CONCLUSIONS: There were significant correlations between performance measures on the ASAT and a validated arthroscopic VR simulator. CLINICAL RELEVANCE: Arthroscopic simulators are available but are limited by their high cost and availability. ASATs may overcome these limitations by using widely available Internet-based software and basic input devices.