Long-Term Survivorship of Modular Cementless Femoral Stem in Complex Primary Total Hip Arthroplasty: A Concise Minimum 15-Year Follow-Up Report

Mean 23-Year Outcomes of Total Hip Arthroplasty Using a Modular Femoral Stem With Metaphyseal Fixation Sleeve

BACKGROUND

Although the modular sleeve concept for femoral implants has several advantages, studies reporting on greater than 20-year outcomes are limited. This study aimed to report the mean 23-year results of total hip arthroplasty (THA) using a modular stem with metaphyseal fixation sleeve.

METHODS

This study reviewed primary THAs performed using a modular stem between October 1994 and April 1998. Of the 272 hips (221 patients) identified, 220 hips (177 patients) satisfying the minimum 20-year follow-up were included. The Harris Hip Score was used for clinical evaluation. Final hip radiographs were analyzed to evaluate the implant stability and the extent of femoral osteolysis. The mean follow-up duration was 23 years (range, 20 to 28).

RESULTS

The mean Harris Hip Score improved from 38 points (range, 26 to 67) preoperatively to 90 points (range, 71 to 100) at the final follow-up (P < .001). Femoral osteolysis was observed in 146 hips (67.1%), but 145 were located proximal to the osseo-integrated sleeve. Overall, 4 femoral revisions were performed; 2 for chronic infection, one for aseptic loosening, and one for periprosthetic femoral fracture. Of the 19 (8.6%) periprosthetic femoral fractures, the most common type was Vancouver AG (13 hips). One (0.5%) asymptomatic distal stem fracture occurred, while no complications were identified at the stem-sleeve junction. Implant survivorship free of any femoral revision was 98.3% at 23 years.

CONCLUSIONS

A THA using a modular stem with metaphyseal fixation sleeve demonstrated 98.3% stem survivorship with excellent clinical outcomes at a mean follow-up of 23 years in non-obese patients.

Outcomes Following Total Hip Arthroplasty in Patients Who Have Charcot Neuroarthropathy of the Hip

BACKGROUND

Historically, Charcot neuroarthropathy hip (CNH) was deemed a contraindication for total hip arthroplasty (THA). However, as implant design and surgical techniques advance, THA for CNH has been performed and documented in literature. Information regarding the outcomes of THA for CNH is limited. The objective of the study was to assess outcomes following THA in patients who have CNH.

METHODS

Patients who have CNH underwent primary THA and had at least 2 years of follow-up were identified in a national insurance database. For comparison, a 1:10 matched control cohort of patients who did not have CNH was created based on age, sex, and relevant comorbidities. Eight hundred and ninety-five CNH patients who underwent primary THA were compared to 8,785 controls. Medical outcomes, emergency department visits, hospital readmissions, and surgical outcomes including revisions between cohorts were evaluated using multivariate logistic regressions.

RESULTS

The CNH patients were found to have higher risks of 90-day wound complications (P = .014), periprosthetic joint infection (P = .013) (P = .021), dislocation (P < .001) (P < .001), aseptic loosening (P = .040) (P = .002), periprosthetic fracture (P = .003) (P < .001), and revision (P < .001) (P < .001) at 1-year and 2-year follow-up, respectively.

CONCLUSION

While patients who have CNH are at a higher risk of wound and implant-related complications, they are comparatively lower than previously reported in literature. Orthopaedic surgeons should be cognizant of the increased risk in this population to provide appropriate preoperative counseling and enhanced perioperative medical management.

Dissociation and Subsequent Stable Malrotation of Femoral Stem Within Sleeve After Sivash-Range of Motion Total Hip Arthroplasty: A Case Report

CASE

A 78 year-old man fell 6 months after Sivash-range of motion (S-ROM) total hip arthroplasty (THA), after which he developed hip pain and external rotation deformity. Imaging showed stem malrotation in relative retroversion. Revision THA was delayed because of medical issues, occurring 1.5 years after the fall. No corrosion was observed intraoperatively at the stem-sleeve interface. His symptoms resolved after revision THA.

CONCLUSION

We present a rare complication of S-ROM THA-dissociation of the femoral stem from the proximal sleeve, with subsequent re-engagement in static malrotation. No corrosion was observed, suggesting that the stem had stably reseated within the sleeve.

Selecting a Press-fit Stem for Total Hip Arthroplasty: The Rationale and Evolution of the Modern Femoral Prosthesis

Noncemented press-fit femoral stems predominate in total hip arthroplasty for all age groups with generally excellent long-term survivorship. The 2021 American Joint Replacement Registry reports that 96% of all elective primary total hip arthroplasties used noncemented femoral implant fixation. 1 Today, there are many styles of press-fit stems, each with supposed benefits, based on a range of design philosophies. Design aspects to consider when selecting a stem are numerous, including stem geometry, stem length, collared or collarless, material properties, and surface structure. Although most stem designs demonstrate excellent results, the differences in stem designs are intimately linked to additional factors such as ease of use/implantation, percentage of surface osseointegration, overall bone removal versus bone stock preservation, subsequent femoral stress shielding, and consideration of complexity of later revision. A surgeon with a broad understanding and appreciation of femoral stem designs should be prepared to select between the multitude of options to best serve individual patients.

Fracture of a Sivash-Range of Motion Femoral Stem at the Diaphyseal Spline

We discuss one of the four reported cases involving the fracture of a spline of the Sivash-range of motion (S-ROM) femoral prosthesis. It occurred in a 71-year-old female patient and was fully discovered during stem extraction in revision total hip arthroplasty (THA). The fractured spline was successfully removed using a reverse curette and fluoroscopic guidance. The placement of a new S-ROM femoral prosthesis was successful, and there were no other orthopedic complications.

Integrins, cadherins and channels in cartilage mechanotransduction: perspectives for future regeneration strategies

Articular cartilage consists of hyaline cartilage, is a major constituent of the human musculoskeletal system and has critical functions in frictionless joint movement and articular homoeostasis. Osteoarthritis (OA) is an inflammatory disease of articular cartilage, which promotes joint degeneration. Although it affects millions of people, there are no satisfying therapies that address this disease at the molecular level. Therefore, tissue regeneration approaches aim at modifying chondrocyte biology to mitigate the consequences of OA. This requires appropriate biochemical and biophysical stimulation of cells. Regarding the latter, mechanotransduction of chondrocytes and their precursor cells has become increasingly important over the last few decades. Mechanotransduction is the transformation of external biophysical stimuli into intracellular biochemical signals, involving sensor molecules at the cell surface and intracellular signalling molecules, so-called mechano-sensors and -transducers. These signalling events determine cell behaviour. Mechanotransducing ion channels and gap junctions additionally govern chondrocyte physiology. It is of great scientific and medical interest to induce a specific cell behaviour by controlling these mechanotransduction pathways and to translate this knowledge into regenerative clinical therapies. This review therefore focuses on the mechanotransduction properties of integrins, cadherins and ion channels in cartilaginous tissues to provide perspectives for cartilage regeneration.