Simon Tiziani

Anterior subcutaneous internal fixation for treatment of unstable pelvic fractures

BackgroundFractures of the pelvic ring including disruption of the posterior elements in high-energy trauma have both high morbidity and mortality rates. For some injury pattern part of the initial resuscitation includes either external fixation or plate fixation to close the pelvic ring and decrease blood loss. In certain situations – especially when associated with abdominal trauma and the need to perform laparotomies – both techniques may put the patient at risk of either pintract or deep plate infections. We describe an operative approach to percutaneously close and stabilize the pelvic ring using spinal implants as an internal fixator and report the results in a small series of patients treated with this technique during the resuscitation phase.FindingsFour patients were treated by subcutaneous placement of an internal fixator. Screw fixation was carried out by minimally invasive placement of two supra-acetabular iliac screws. Afterwards, a subcutaneous transfixation rod was inserted and attached to the screws after reduction of the pelvic ring. All patients were allowed to fully weight-bear. No losses of reduction or deep infections occurred. Fracture healing was uneventful in all cases.ConclusionMinimally invasive fixation is an alternative technique to stabilize the pelvic ring. The clinical results illustrate that this technique is able to achieve good results in terms of maintenance of reduction the pelvic ring. Also, abdominal surgeries no longer put the patient at risk of infected pins or plates.

Correlation of pelvic incidence with radiographical parameters for acetabular retroversion: a retrospective radiological study

BackgroundPelvic incidence (PI) has been linked to several degenerative processes within the spinopelvic system. Acetabular retroversion is a recognised risk factor for osteoarthritis of the hip. We therefore hypothesised that these two factors might be part of a specific anatomical variant associated with degenerative changes. This study was performed to clarify this issue.MethodsThe pelvic incidence was measured on 589 computertomographical data sets acquired between 2008 and 2010. For 220 patients a 2D rendering in an antero-posterior view of the CT data set was performed to evaluate the parameters of acetabular retroversion. Those included the prominence of the ischial spine sign (PRISS), the cross-over sign (COS) and the posterior wall sign (PWS). Between 477 and 478 hips were evaluated depending on the parameter of retroversion.ResultsThe mean pelvic incidence was significantly lower in hips positive for the PRISS and the PWS. However, there were no significant differences between hips positive or negative for the COS.DiscussionAs hypothesised, the lower PI values in PWS and PRISS positive hips suggest a link between PI and retroversion of the acetabulum. Whether this is of any clinical relevance remains, however, unknown.ConclusionAcetabular retroversion is linked to PI. In hips where the prominence of the ischial spine sign and/or the posterior wall sign was present, the mean pelvic incidence value was lower.

Biomechanical Comparison of Different External Fixation Configurations for Posttraumatic Pelvic Ring Instability

Background. External fixation is useful in the primary treatment of pelvic ring injuries. The present study compared the biomechanical stability of five different configurations of an external pelvic ring fixation system. Methods. Five configurations of an anterior external pelvic ring fixation system were tested using a universal testing machine. One single connecting rod was used in group “SINGLE,” two parallel connecting rods in group “DOUBLE,” two and four rods, respectively, in a tent-like configuration in groups “SINGLE TENT” and “DOUBLE TENT,” and a rhomboid-like configuration in group “RHOMBOID.” Each specimen was subjected to a total of 2000 consecutive cyclic loadings at 1 Hz lateral compression/distraction (±50 N) and torque (±0.5 Nm) loading alternating every 200 cycles. Translational and rotational stiffness were determined at 100, 300, 500, 700, and 900 cycles. Results. The “SINGLE TENT” and “RHOMBOID” configurations already failed with a preloading of 50 N compression force. The “DOUBLE” configuration had around twice the translational stability compared with the “SINGLE” and “DOUBLE TENT” configurations. Rotational stiffness observed for the “DOUBLE” and “DOUBLE TENT” configurations was about 50% higher compared to the SINGLE configuration. Conclusion. Using two parallel connecting rods provides the highest translational and rotational stability.

Medial acetabular wall breach in total hip arthroplasty – is full-weight-bearing possible?

BACKGROUND A breach of the medial acetabular wall is a phenomenon seen frequently due to over-reaming during total hip arthroplasty (THA). The consequences of this issue are not fully understood particularly in cementless THA. A retrospective study was performed to answer whether: immediate postoperative full-weight-bearing in the presence of a medial acetabular wall breach after THA results in more short-term revisions of the acetabular component, and increases the risk for migration of the acetabular component? HYPOTHESIS Immediate full-weight-bearing in the presence of a medial breach is not associated with an increased likelihood for acetabular-related revision surgery or migration of the cup. PATIENTS AND METHODS In this retrospective cohort study, consecutive patients (n=95; mean age 68±13 years; 67 female) who underwent THA with an uncemented acetabular component were identified and a retrospective chart review was performed (follow-up 23±17 months, range 6 to 79 months). The presence of a postoperative radiographic medial acetabular breach was documented and the need for revision surgery and the rate of acetabular component migration were assessed during follow-up. RESULTS Some extent of radiographic medial acetabular wall breach was seen in 26/95 patients (27%). With regard to the primary outcome, 2/95 patients (2%) required revision surgery during follow-up. All revision surgeries occurred in the group without a medial breach (p=0.280) for causes related to the femoral or the head components. Persistent pain was present in 1/26 patients (3.8%) in the medial breach group and 8/69 patients in the control group (11.6%; p=0.436). In the radiographic follow-up (n=81), there was no significant difference between the control group and the medial breach group with regard to cup migration (Δ ilio-ischial overlap [distance between the ilio-ischial line and a parallel line tangential to the acetabular cup on AP views]: -0.5±0.9mm [range, -2.9 to 0.8] vs. -0.3±1.7mm [range, -1.9 to 2.2], Δ overlap tangent [defined as the distance between the two crossings of ilio-ischial line and the acetabular component on AP views]: -2.2±6.1mm [range, -21.4 to 0.0] vs. 0.4±6.9mm [range, -6.2 to 17.6]). Similarly, according to variation in the ilio-ischial overlap distance between postoperative and follow-up on pelvic AP views, 0/56 hips (0%) had cup migration ≥ 5mm in the control group versus 1/25 (4%) in the medial breach cohort (p=0.3). DISCUSSION In this retrospective observation of patients with immediate postoperative full-weight-bearing after THA, a radiographic breach of the medial acetabular wall was not associated with an increased risk for short-term revision surgery or radiographic migration at follow-up. According to the findings of this study and in the light of previous biomechanical studies, there is no clear evidence for postoperative partial weight-bearing in case of a medial breach as far as the surgeon feels that the acetabular component is stable. LEVEL OF EVIDENCE IV, Retrospective cohort study.

Medical Writing: Systematic Reviews and Meta-analyses

Until three decades ago, access to medical knowledge represented a major limiting factor, on one hand. Medical books were priced highly, so that they were limited to larger libraries or wealthy individuals. On the other hand, these textbooks tended to be out of date rather quickly, and there were difficulties in keeping up with the rapidly growing body of knowledge in due time.

Mid-term follow-up after surgical treatment of fragility fractures of the pelvis

INTRODUCTION Early operative treatment of fragility fractures of the pelvis (FFP) has been suggested to reduce pain and allow for earlier mobilization. The aim of this study was to determine mortality and functional outcome after operative treatment. PATIENTS AND METHODS Patients aged ≥60 years (n = 60; mean age 79 years, 53 female) who had operative treatment of a FFP and a follow-up of at least 2 years were identified and mortality was assessed using a national social insurance database. Those who had survived were contacted by phone and a modified Majeed Score was obtained. RESULTS At final follow up (62 months, range, 29-117), 32 patients (53.3%) had deceased. One-year-mortality rate was 28.3% and 2-year mortality was 36.7%. Mortality was not linked to fracture type (p > .05). Complications during hospitalization occurred in 26/60 patients (43.3%). Patients with a bilateral FFP had a longer hospitalization (18 vs. 11 days; p = .021). The mean modified Majeed score of surviving patients was 65 points (85.5% of achievable maximum). CONCLUSION Mortality and in-hospital complications remain high among patients with FFP even when treated operatively. A longer hospitalization can be expected in patients with posterior bilateral fractures.