The bridging infix : a modified, minimally invasive subcutaneous anterior pelvic fixation technique

Various methods for anterior pelvic ring fixation have been described in the literature, each with specific advantages and disadvantages. We describe a modified minimally invasive subcutaneous technique for anterior fixation: the Bridging Infix. It combines the benefits of internal plate fixation with external fixator principles. We merged and modified features of the existing INFIX and Pelvic Bridge techniques during the design. Similar to these techniques, we use plate-rods typically used during occipitocervical fusions. The design changes allow for less discomfort due to prominent hardware in thin patients and eliminate the need for an intact medial pubic rami for fixation. There is also no risk of bladder injury due to accidental screw perforation through the pubic rami. The Bridging Infix is ideal for patients who are physiologically too frail for extensive open reduction and plate osteosynthesis, such as elderly patients with pelvic fragility fractures who are failing to mobilise due to pain. It can also be used for patients in whom external fixators may be impractical or poorly tolerated, such as obese patients or those with increased nursing demands. This technique does not provide adequate posterior pelvic ring stability, thus it requires an intact posterior tension band or the addition of separate posterior fixation. Patients can commence in-bed mobilisation the same day as the procedure, with weight-bearing as tolerated allowed for most cases, and toe-touching reserved for highly unstable injury patterns only. The implants are not routinely removed unless requested by the patient, especially in the elderly to avoid additional anaesthetic exposure. Potential complaints include lateral thigh pain, due to lateral femoral nerve compression, and mechanical discomfort during exercise activities.https://www.saoj.org.za/index.php/saoj%20am2024Orthopaedic SurgerySDG-03:Good heatlh and well-bein

Establishing the safety of the lateral femoral cutaneous nerve when using the bridging infix for anterior pelvic fixation

BACKGROUND Established subcutaneous internal fixation techniques have shown a better quality of life with reduced pain. However, complications still arise, with the most significant being injury of the lateral femoral cutaneous nerve (LFCN). A novel minimally invasive modified technique, the Bridging Infix, has been proposed; however, the safety of the LFCN during the procedure is currently unknown. The aim of the study, therefore, was to determine the relationship between the Bridging Infix and the LFCN. METHOD Fifty formalin-fixed cadaveric specimens and two fresh frozen cadaver specimens were utilised in the study. The Bridging Infix was inserted as per the technique guide. Superficial dissection of the surgical site was subsequently conducted. Bilateral measurements of the distance between the LFCN and the implant as well as palpable bony landmarks were taken to determine safe zones for implant placement. RESULTS Overall the LFCN was identified coursing deep to the inguinal ligament. The minimum distance from the LFCN to the most proximal cortical screw was 18.00 mm. The mean distance from the most proximal screw to the LFCN was 37.97 ± 12.20 mm. CONCLUSION The LFCN was not injured or impinged by the Bridging Infix in any of the cadaver specimens used in this study. Thus, the surgical procedure can be considered safe if layer by layer dissection is employed and the screws are directly inserted on the iliac crest, with no pressure being applied within three finger breadths medial to the anterior superior iliac spine.The National Research Foundation (NRF) of South Africa.http://journal.saoa.org.zaam2024AnatomyStatisticsSDG-03:Good heatlh and well-bein

Minimally invasive subcutaneous anterior fixation of pelvic fractures in the elderly : case report and literature review

BACKGROUND: As our population ages, the incidence of pelvic fragility fractures will rise accordingly. Despite these fractures having similar mortality rates to proximal femur fractures, there exist discrepancies between the management of these injuries. Although a number of pelvic fragility fractures can be treated successfully with conservative means, early treatment with appropriate surgical means should be considered in those failing conservative treatment or with unstable fracture patterns. CASE REPORT: We present an 84-year-old female who sustained a pelvic fragility fracture after a low-energy fall. Despite adequate conservative treatment, she was unable to mobilise. She was taken for anterior and posterior fixation, using our modified minimally invasive subcutaneous technique (the Bridging Infix) for anterior fixation. At the six-week follow-up she had regained full independent mobility. She had three syncope-related falls during this period, but radiographs revealed no sign of implant displacement. One year after her surgery she had complete union of her fracture, good function and no desire to have the implant removed. DISCUSSION: With the expected increase in pelvic fragility fractures due to the growing elderly population, our understanding of these injuries has begun to change. Occult posterior ring injuries have been described in up to 80% of cases, while fracture progression to unstable patterns can occur in up to 15% of stable patterns. Despite conservative management being the primary treatment of choice, these patients suffer morbidity and mortality rates comparable to proximal femur fractures. Early appropriate surgical management should be considered in patients failing to mobilise. Various surgical techniques have been described, each with their own advantages and disadvantages. Newer minimally invasive techniques are gaining favour, especially for use in elderly patients. These constructs combine the low profile benefits of internal plate fixation with ex-fix principles. CONCLUSION: The Bridging Infix is a modified technique for minimally invasive subcutaneous anterior pelvic fixation. Its use can strongly be considered by even the general orthopaedic surgeon in cases where patients are too frail for extensive or invasive surgeries, such as open reduction and internal fixation with plate and screws.https://www.saoj.org.zaOrthopaedic Surger

The Knee Osteoarthritis Grading System for arthroplasty

BACKGROUND : The aim of this study is to validate the Knee Osteoarthritis Grading System (KOGS) of progressive osteoarthritic degeneration for the tri-compartmental knee. This system defines the site and severity of osteoarthritis to determine a specific knee arthroplasty. METHODS : The radiographic sequence for KOGS includes standing coronal (anteroposterior), lateral, 30 skyline patella, 15 and 45 Rosenberg and stress views in 20 of flexion. Cohen’s kappa and related agreement statistical methods were used to assess the level of concordance of the 7 evaluators between A and B cohorts for each evaluator and also against the actual arthroplasty used. Sensitivity and specificity was also assessed for the KOGS in identifying true partial knee arthroplasties (PKAs) and total knee arthroplasties (TKAs) as decided from the cohort A evaluations. RESULTS : From a cohort of 330 patients who were included in the study, 71 (22.5%) underwent a TKA procedure, 258 (78.2%) a PKA, and 1 (0.3%) was neither a TKA nor PKA. KOGS was able to identify true PKAs (sensitivity) in the range of 92.2%-98.5% across all the different evaluators. The KOGS method was able to identify a PKA or a TKAwith an accuracy ranging from92% to 98.8% across all different evaluators. The surgical results after 20 months are at least comparable with the expected average in the academic literature. CONCLUSION : The KOGS classification provides a reliable and accurate tool to assess suitability of an individual patient for undergoing PKA or TKA.http://www.arthroplastyjournal.orgOrthopaedic Surger