Although some authors have published their internal fixation algorithm for treating acetabular fractures at any age, however, the special fixation protocol was not proposed especially for the senior patient population. This manuscript was aimed to address such a particular GAAF involving the QLS in elderly patients with “frame and buttress” principle. As the senior aged patients frequently accompanied with age-related osteoporosis and other significant comorbidities, which would result in the comminuted fractures of QLS by even falling from a standing height or other low-energy injury. Therefore, the goal of such operation was to achieve a congruent and stable hip joint at the expense of a perfect reduction to minimize the surgical insult on a more senior patient. Additionally, a stable hip joint could allow patients for early functional exercise and even afford a favorable opportunity for future hip arthroplasty. Forming a skeletal frame structure to reconstruct the broken QLS and afford a base to resist the tendency of protrusion were the hinge to treat the type of fractures for whether old or young patients.
Reviews from researches published recently about the exact definition of QLS, however, the description of the QLS was unclear. W.A. ElNahal et al published that the QLS extended from the pelvic brim superiorly till a line joining the ischial spine and obturator foramen inferiorly, and was bound by the greater sciatic notch posteriorly and the obturator foramen anteriorly. Inspired by the work above and the work by Letournel E and Judet R, we redefined the “frame” treatment of the QLS and described the components of the new definition. The “frame” was constituted with three consecutive borders of the QLS: the first border was the AC, superior of the QLS, the second border was the PC, posterior of the QLS and the third border was the obturator foramen, anterior of the QLS. There were various of methods to rebuild up the consecutive construction of above three borders, including lag screws placement and plates fixation, which depended on whether the bone quality was allowable. Lag screws fixation was a classical method to perform and achieve well clinical effect. The insertion direction of PC lag screw was decided by the height of fracture line on the PC, the PC lag screw was inserted directing to ischial spine if the fracture line was superior to the ischial spine, otherwise, the direction was inserted to the ischial tuberosity, which rebuilt up the construction of the broken PC superior of the QLS. However, if the PC fracture was not amenable to this screw fixation, the iliosciatic plate fixation was a selectable method to stabilize the PC. Conventionally, the AC was fixed by a reconstruction plate positioned on upper surface of the pelvic brim with cancellous screws, which had more potential holding power for osteoporosis patients, when open operation was performed to rebuild up the integrity of the QC, superior border of the QLS. Culemann et al employed an additional infra-acetabular lag screw, which significantly increased the fixation strength of acetabular fracture and rebuilt up the third border of QLS, however, the placement of the infra-acetabular screw was challenging and need professional skills, because it was accessible to penetrate into joint. Therefore, the placement of a plate was an alternative method to stabilize the third border of QLS. On the base of the reconstructed frame of QLS, which was one of the pivotal steps to reduce and stabilize the QLS.
In 2004, Qureshi et al published a internal fixation technique for the treatment of acetabular fracture, who used a 9-hole reconstruction plate applied as an infra-pectineal buttress plata along the QLS and described that there was no occupation of reduction or fixation loss with the infra-pectineal plate. The infra-pectineal plate was effective to provide the desired buttress effect and resist the medial displacement of the QLS, which reduced the rate of secondary dislocation/subluxation of head and fixation loss. Nevertheless, it was invalid for comminuted fractures. Mears and Farid reported a technique that they used braided cables or heavy wires for encircling the QLS, which tied up the fracture fragments and refrained the displacement. The tighten wires provided buttress effect to the protrusion-type acetabular fractures, however, the wires technique was merely used for QLS fractures without small-size fragments, which could not buttress the comminuted fractures. M.A. Karim et al used a row of screws inserting through a reconstruction plate placed along the pelvic brim to resist the protrusive QLS, which resisted the protrusion of hip. However, it only provided resistance to the hip not formed desired buttress effect to the QLS, if the gap was existing between the screws and the QLS, the tendency of reduction loss would never disappear. Kistler et al and R.K. Sen et al published their innovation of QLS buttress plates, their plates provided partial buttress and resistant effect to the broken QLS reducing the rate secondary displacement of fractures. Chen et al reported biomechanical comparison of different fixation techniques including a special infrapectineal QLS buttress plate, compared with other plates, which not only provided entire buttress and resistant effect to the broken QLS especial the comminuted fractures, but also formed entire frame of the QLS. This technique fully reflect the “frame and buttress” fixation strategy.(Fig. 1-A,B) In addition, the maintenance of gap between the QLS with the plate about 2mm could afford a more mechanically stable support effect to the fracture region. In the metaphor of this fixation strategy, reconstructing the frame was similar to piece the broken bottom of a bowl and the internal fixators were similar to some patches used for stabilizing and buttressing the bottom.(Fig. 1-A)
A direct view to the QLS in the help of surgical approaches would assist surgeons to reduce and fix the fracture region. The supra-ilioinguinal approach was performed only in all patients involved, in despite of there were various AIP approaches such as Sttopa and modified Ilioinguinal could be selectable for treatment of acetabular fractures. With the third and the fourth windows of the approach, we realized a direct visualization and direct management of the QLS, which was convenient for surgeons to rebuild up the congruity of the intra-pelvic fractures.
As for our study, 28 patients with age ≥ 55 years and acetabular fractures involving the QLS were treated using the our fixation strategy. 17(60.7%) patients acquired excellent reduction, 9(32,1%) patients acquired good reduction evaluating by the Matta scoring system. Meanwhile, the clinical functional recovery results were evaluated by Merle D'Aubigné-Postel system at the last follow-up: 24(85.7%) patients were graded as excellent or good. In the period of follow-up time, there was only one patient occurred reduction loss and lastly performed total hip operation. We were applying ourself to analyzing the reasons, the loss of fixation might be the result of severe osteoporosis and the insufficient post-operative traction time, which resulted the medial wall in being struck by the femoral head and eventually the stabilization of fixation was fault. As geriatric acetabular fractures were usually resulted by low-energy trauma and combined with other comorbidities, some patients could not tolerate the procedure of operation. Therefore, the patients enrolled in our study were limited, it was necessary to include more patients to verify the fixation strategy. On the other hand, our study was focusing on the elderly patients, the fixation effect to young patients was lack, but this fixation strategy was also able to treat young patients with acetabular fractures involving the QLS requiring further clinical validation.
The reconstruction of the frame was to rebuild up the integrity of the QLS and achieve a congruent and stable hip joint to minimize the surgical insult on elderly patients. With the use of some special plates to resist the medial protrusive QLS buttressing these medial displaced fragments, which efficiently refrained secondary dislocation/subluxation of femoral head and medial displacement of QLS.(Fig. 3)