Influence of Fixation Methods on Prosthetic Joint Infection Following Primary Total Knee Replacement: Meta-Analysis of Observational Cohort and Randomised Intervention Studies

The type of fixation used in primary total knee replacement (TKR) may influence the risk of prosthetic joint infection (PJI). We conducted a systematic review and meta-analysis to assess published evidence linking type of fixation (cemented, uncemented, or hybrid) with the risk of PJI following primary TKR. Randomised controlled trials (RCTs) and observational cohort studies comparing fixation methods and reporting PJI incidence following primary TKR were identified in MEDLINE, Embase, Web of Science, and Cochrane Library up until November 2018. Summary measures were relative risks (RR) with 95% confidence intervals (CIs). We identified 32 eligible articles (24 observational studies and 8 RCTs) involving 1,161,292 TKRs. In pooled analysis of observational studies, uncemented fixation was associated with a decreased overall PJI risk when compared with cemented fixation at 0.76 (0.64–0.89). Comparing antibiotic-loaded cemented fixation with plain cement, there was no significant difference in overall PJI risk at 0.95 (0.69–1.31), but PJI risk was increased in the first 6-month postoperative period to 1.65 (1.12–2.43). Limited data from RCTs showed no differences in PJI risk among the fixation types. Observational evidence suggests uncemented fixation may be associated with lower PJI risk in primary TKR when compared with cemented fixation. In the early postoperative period, antibiotic-loaded cemented fixation may be associated with increased PJI risk when compared with plain cement. This may either reflect appropriate selection of higher risk patients for the development of PJI to cemented and antibiotic-loaded cement or may reflect a lower PJI risk in uncemented TKR due to factors such as shorter operative time.

An Alternative Femoral Stem-bone Implantation Technique Using an Innovative Short Femoral Stem Endoprosthesis

Arthroplasty of the hip, for either arthritic changes or femoral neck fracture, is a common procedure in orthopedic surgery. Although the standard designs for implantation, either cemented or uncemented, are well described and studied, there are also alternative designs regarding the implantation of both prosthetic stem and cup. This paper aims to explore one such alternative design, using the screw-in technique. It has been described in past literature for uncemented fixation of both the cup and the stem, and the biomechanical principles of fixation are different from the classical methods, offering certain advantages that are insufficiently explored in current-day endoprosthesis. Also, we will be presenting an innovative femoral stem design, recently developed, that combines an uncemented screw-on technique with a cemented augmentation possibility, aimed to provide the practitioner with the advantages of a bone-preserving mini-stem design, combined with the innovative screw-in fixation technique and the versatility of the hybrid cemented/uncemented fixation method.

Modular endoprosthetic implant for maximizing residual limb length: A case report

Background: For transfemoral amputations, the residual femoral length is critically important to prosthetic function. The aim of this report is to describe a novel method of extending femoral length and to assess its stability over time. Case Description and Methods: A 57-year-old woman with recurrent parosteal osteosarcoma was treated with above-knee amputation. A portion of the distal femoral endoprosthesis, which included uncemented fixation with a Compress® stem, was retained in an effort to extend the short femoral remnant and maximize stump length. Findings: At 3 years follow-up, the Compress stem remained well-fixed, and there was no soft tissue breakdown over the implant. The patient ambulated with a prosthetic limb and no external support. Outcomes and Conclusion: To the best of our knowledge, this is the first report of using the Compress device as a means to maintain stable fixation and extend residual femoral length following above-knee amputation. Clinical relevance Extension of residual bone length in amputated limbs can help improve prosthetic fitting and function. The Compress device may be useful in this application as a means of secure fixation for a modular metallic prosthesis.