Posterior Tibial Slope in Anterior Cruciate Ligament Surgery: A Systematic Review.

Background: While the literature suggests a correlation between posterior tibial slope and sagittal stability of the knee, there is a lack of consensus relating to how to measure the slope, what a normal slope value would be, and which critical values should guide extra surgical treatment. We performed a systematic literature review looking at the posterior tibial slope and cruciate ligament surgery. Our aims were to define a gold standard measurement technique of posterior tibial slope, as well as determining its normal range and the important values for consideration of adjuncts during cruciate ligament surgery. Methods: Electronic searches of MEDLINE (PubMed), CINAHL, Cochrane, Embase, ScienceDirect, and NICE in June 2020 were completed. Inclusion criteria were original studies in peer-reviewed English language journals. A quality assessment of included studies was completed using the Methodological Index for Non-Randomized Studies (MINORS) Criteria. Results: Two-hundred and twenty-one papers were identified; following exclusions 34 papers were included for data collection. The mean MINORS score was 13.8 for non-comparative studies and 20.4 for comparative studies, both indicating fair to good quality studies. A large variation in the posterior tibial slope measurement technique was identified, resulting in a wide range of values reported. A significant variation in slope value also existed between different races, ages and genders. Conclusion: Cautiously, the authors suggest a normal range of 6-12º, using the proximal tibial axis at 5 and 15 cms below the joint. We suggest 12º as a cut-off value for slope-reducing osteotomy as an adjunct to revision ligament reconstruction.

Prosthetic joint infection of the knee - arthroscopic biopsy identifies more and different organisms than aspiration alone.

BACKGROUND: Prosthetic joint infection (PJI) causes significant morbidity and mortality following knee replacement surgery. Identifying causative organisms and antibiotic sensitivities is critical in increasing the chance of infection eradication. This study investigated whether biopsy alone was superior to aspiration alone for serological diagnosis in PJI following knee replacement. Secondly, we investigated whether biopsy identifies the same or new/different microbiological flora as aspiration. METHODS: Since December 2014, the Exeter Knee Reconstruction Unit (EKRU) has prospectively collated data regarding all PJIs referred from our local/regional network which have been reviewed via our Multi-Disciplinary Team (MDT). We identified and included consecutive patients from this MDT from Dec.2014-Mar.2020 and analysed their electronic records. Statistical analysis was performed using Stata. RESULTS: 65/100 patients studied had both pre-operative aspiration and biopsy. 31/65 (48%) had positive aspiration and biopsies. No aspirate samples were positive with corresponding biopsies negative. In 19/65 (29%) of infection positive patients, biopsy identified new (7) or additional (12) organisms not identified by aspiration. Aspiration had a sensitivity of 70%, specificity of 88%, positive predictive value of 90.3% and negative predictive value of 64.7%. Biopsy had a sensitivity of 97.5%, specificity of 88%, positive predictive value of 92.9% and negative predictive value of 95.7%. CONCLUSION: In 29% of confirmed PJI cases, arthroscopic biopsy identified either additional organisms in a polymicrobial PJI when compared to aspiration, or new positive results when aspiration alone was negative. This study demonstrates the benefits of arthroscopic biopsy for serological diagnosis in cases of knee PJI and aids treatment planning.

Does Medial Overhang of the Greater Trochanter Influence Femoral Stem Position During Cemented Hip Arthroplasty? A Retrospective Radiological Review.

Purpose We investigate the effect that variation in the anatomy of the greater trochanter (GT), in particular the medial overhang, can have on femoral stem alignment in total hip arthroplasty (THA). Methods Pre- and post-operative anteroposterior pelvic radiographs of 576 consecutive patients undergoing THA were retrospectively analysed. Medial overhang of the GT relative to the lateral femur diaphysis was measured. The femoral morphology was classified according to Dorr classification. The alignment of the femoral stem axes on post-operative radiographs was recorded. Results Following exclusions, 500 THAs performed by six surgeons all using the same cemented polish tapered stems were analysed: 320 THAs were performed via the posterior-lateral approach and 180 via the direct-lateral approach. Mean stem varus was 0.53° (range: -7 to 7°). Mean medial overhang was 21 mm (range: 8-43 mm). An overhang of <20 mm had a mean varus of -0.1°, an overhang of 20-30 mm had a mean varus of 0.8° and an overhang of >30 mm had a mean varus of 2.33°. Those with an overhang of <20 mm had a 2% chance of significant varus (≥4°), increasing to 9.5% for 20-30 mm and 44.4% for >30 mm. One-way analysis of variance comparison of these groups returned a p-value of <0.0001. Dorr type A femora had a mean varus of 0.52°, Dorr B had a mean varus of 0.54° and Dorr C had a mean varus of 0.46°. The posterior-lateral approach had a mean varus of 1.05° (range: -7 to 7°) compared to -0.40° (range: -5 to 5°) for direct-lateral approach. The t-test comparing approach was p < 0.0001. Discussion The extent of medial overhang of the GT can adversely affect the final stem position in THA, resulting in a statistically significant increase in mean stem varus. There is a linear relationship between stem position and GT overhang, with an increased chance of significant varus malposition (44.4% with >30 mm of overhang). Conclusions Scrutiny of pre-operative radiographs to determine high-risk patients is important, and we propose a classification system of GT anatomy to aid assessment.

Improving the surgical consenting process for patients with acute hip fractures: a pilot quality improvement project.

BACKGROUND: Consenting patients for trauma procedures following hip fracture is a key stage in the treatment pathway from admission to the operating theatre. Errors in this process can result in delayed procedures which may negatively impact patient recovery. The aim of this project was to identify and reduce errors in our consenting process for patients with capacity. METHODS: Consent forms for all adult patients with capacity admitted for surgical repair of traumatic hip fracture were reviewed over a 4-week period. The baseline measurement (n = 24), identified errors in three key process measures: clarity of documentation, failure to record procedure-specific risks and not offering a copy of the consent form to the patient. Pre-printed stickers and targeted teaching were then introduced as quality improvement measures. Their impact was evaluated over subsequent 4-week review of the same patient demographic, with further refinement of these interventions being carried out and re-evaluated for a final cycle. RESULTS: Cycle 1 (n = 26) following targeted teaching demonstrated a reduction in abbreviations from 38 to 20%, while doubling the documentation of discussion of procedure-specific risks from 31 to 72%. More patients were offered a copy of their consent form, rising from 12 to 48%. Cycle 2 (n = 24) saw the introduction of pre-printed "risk of procedure" stickers. Although clarity measures continued to improve, quality of pre-procedure risk documentation remained static while the number of forms being offered to patients fell to 8%. CONCLUSIONS: Our project would suggest that while pre-printed stickers can be useful memory aids, specific teaching on consenting produces the greatest benefit. The usage of such tools should therefore be limited, as adjuncts only to specific training.