The outcome of the uncemented acetabular component in delayed total hip arthroplasty following acetabular fractures

Aims After failed acetabular fractures, total hip arthroplasty (THA) is a challenging procedure and considered the gold standard treatment. The complexity of the procedure depends on the fracture pattern and the initial fracture management. This study’s primary aim was to evaluate patient-reported outcome measures (PROMs) for patients who underwent delayed uncemented acetabular THA after acetabular fractures. The secondary aims were to assess the radiological outcome and the incidence of the associated complications in those patients. Methods A total of 40 patients underwent cementless acetabular THA following failed treatment of acetabular fractures. The postoperative clinical and radiological outcomes were evaluated for all the cohort. Results The median (interquartile range (IQR)) Oxford Hip Score (OHS) improved significantly from 9.5 (7 to 11.5), (95% confidence interval (CI) (8 to 10.6)) to 40 (39 to 44), (95% CI (40 to 43)) postoperatively at the latest follow-up (p < 0.001). It was worth noting that the initial acetabular fracture type (simple vs complex), previous acetabular treatment (ORIF vs conservative), fracture union, and restoration of anatomical centre of rotation (COR) did not affect the final OHS. The reconstructed centre of rotation (COR) was restored in 29 (72.5%) patients. The mean abduction angle in whom acetabular fractures were managed conservatively was statistically significantly higher than the surgically treated patients 42.6° (SD 7.4) vs 38° (SD 5.6)) (p = 0.032). We did not have any case of acetabular or femoral loosening at the time of the last follow-up. We had two patients with successful two-stage revision for infection with overall eight-year survival rate was 95.2% (95% CI 86.6% to 100%) with revision for any reason at a median (IQR) duration of follow-up 50 months (16 to 87) months following THA. Conclusion Delayed cementless acetabular THA in patients with previous failed acetabular fracture treatments produces good clinical outcomes (PROMS) with excellent survivorship, despite the technically demanding nature of the procedure. The initial fracture treatment does not influence the outcome of delayed THA. In selected cases of acetabular fractures (either nondisplaced or with secondary congruency), the initial nonoperative treatment neither resulted in large acetabular defects nor required additional acetabular reconstruction at the time of THA. Cite this article: Bone Jt Open 2021;2(12):1067–1074.

Therapeutic farriery of the hind feet for horses with hindlimb orthopaedic injuries

Low heels and negative plantar angles in the hind feet are the most common hind foot conformational abnormality. A causal relationship has been demonstrated between these conditions and hindlimb lameness. It is important these abnormalities are recognised during thorough orthopaedic examinations, so they can be quantified with radiography and appropriately treated with therapeutic farriery to restore optimal hoof conformation, balance and function. This is an essential part of a holistic approach to treating horses with hindlimb lameness. Farriery intervention for these abnormalities involves returning the plantar half of the foot to a load-sharing plane between the frog and heels, restoring phalangeal alignment and providing increased ground surface plantar to the centre of rotation of the distal interphalangeal joint.

Three-dimensional pre-operative planning of primary hip arthroplasty: a systematic literature review

Three-dimensional (3D) pre-operative planning in total hip arthroplasty (THA) is being recognized as a useful tool in planning elective surgery, and as crucial to define the optimal component size, position and orientation. The aim of this study was to systematically review the existing literature for the use of 3D pre-operative planning in primary THA. A systematic literature search was performed using keywords, through PubMed, Scopus and Google Scholar, to retrieve all publications documenting the use of 3D planning in primary THA. We focussed on (1) the accuracy of implant sizing, restoration of hip biomechanics and component orientation; (2) the benefits and barriers of this tool; and (3) current gaps in literature and clinical practice. Clinical studies have highlighted the accuracy of 3D pre-operative planning in predicting the optimal component size and orientation in primary THAs. Component size planning accuracy ranged between 34–100% and 41–100% for the stem and cup respectively. The absolute, average difference between planned and achieved values of leg length, offset, centre of rotation, stem version, cup version, inclination and abduction were 1 mm, 1 mm, 2 mm, 4°, 7°, 0.5° and 4° respectively. Benefits include 3D representation of the human anatomy for precise sizing and surgical execution. Barriers include increased radiation dose, learning curve and cost. Long-term evidence investigating this technology is limited. Emphasis should be placed on understanding the health economics of an optimized implant inventory as well as long-term clinical outcomes. Cite this article: EFORT Open Rev 2020;5:845-855. DOI: 10.1302/2058-5241.5.200046

Severe Leg Length Discrepancy after Total Hip Arthroplasty: Where is the Problem- Cup or Stem? A Retrospective Controlled Study

Background: The factors that contribute to the severe leg length discrepancy (LLD) after total hip arthroplasty (THA) are presently unclear. In the current study, we investigated whether the acetabular cup position and femoral stem are related to the patients with severe LLD by comparing with patients who had the leg length equality.Materials and Methods: Between June 2013 and July 2019, patients undergoing unilateral primary THA in the Department of Orthopaedics at our institution were screened. According to the postoperative leg length difference, a total of 178 patients were included in the study. A group of 107 patients had leg length equality (LLD≤3 mm) and the other group of 71 patients had severe LLD (LLD≥15 mm). A standardized protocol for evaluation of anteroposterior hip radiographs was used to measure the postoperative LLD. The difference of acetabular cup position (vertical centre of rotation (VCR), horizontal centre of rotation (HCR)) and the femoral stem(stem height; stem size; femoral neck osteotomy level) between the two groups. We also assessed whether there was a difference in proximal femur morphology between the two groups.Results: On the femoral side, the mean stem height of (70.82±5.49) mm in the severe LLD group was significantly different from the (67.35±6.88) mm mean discrepancy in the leg length equality group (P < .001). Stem size and femoral neck osteotomy level showed no statistically differences between the two groups (P>0.05). On the acetabular side, there was no significant difference between the two groups in the VCR and HCR (P>0.05) . There was also no statistical difference in proximal femur morphology between the two groups (P>0.05).Conclusion: The main reason for the occurrence of severe LLD may be due to improper treatment of the femur side. Although preoperative template could choose a better stem size and femoral neck osteotomy level, surgeons need to pay more attention to the whole operation process of the femur stem.

Mejora de la ubicación del centro articular de un sistema de captura de movimiento sin marcadores a través de un método de calibración funcional: estudio piloto

El análisis biomecánico es una herramienta para evaluar movimientos patológicos y su rehabilitación. Esta investigación estudia la factibilidad de mejoras en la ubicación del centro articular de cadera en un Sistema de Captura de Movimiento sin Marcadores a través de la aplicación de un método de calibración funcional. Se analizó el movimiento de una joven mujer sin impedimentos físicos. Se adquirió simultáneamente información del sistema gold standard (Motion Capture System, MOCAP) y una alternativa de bajo costo (Microsoft Kinect). Se grabaron adquisiciones estáticas y dinámicas. A partir de la información obtenida con Kinect, se crearon cinco marcadores virtuales para cada pierna y se introdujeron en optimal common shape technique y en symmetrical centre of rotation estimation method para determinar los centros articulares de ambas caderas. Los resultados mostraron mejora en la ubicación del centro de rotación cuando fueron comparados con la información de MOCAP. En conclusión, este enfoque podría mejorar la información obtenida con Kinect y demostró ser un método factible deaplicación en el campo de la rehabilitación.