Aim

The number of operatively treated clavicle fractures has increased over the past decades. Consequently, this has led to an increase in secondary procedures required to treat complications such as fracture-related infection (FRI). The primary objective of this study was to assess the clinical and functional outcome of patients treated for FRI of the clavicle. The secondary objectives were to evaluate the healthcare costs and propose a standardized protocol for the surgical management of this complication.

Prophylactic treatment is advised for metastatic bone disease patients with a high risk of fracture. Clinicians face the task of identifying these patients with high fracture risk and determining the optimal surgical treatment method. Subject-specific finite element (FE) models can aid in this decision process by predicting the mechanical effect of surgical treatment. In this study, we specifically evaluated the potential of FE models to simulate femoroplasty, as uncertainty remains whether this prophylactic procedure provides sufficient mechanical strengthening to the weight-bearing femur.

In eight pairs of human cadaveric femurs artificial metastatic lesions were created. In each pair, an identical defect was milled in the left and right femur. Four pairs received a spherical lesion in the neck and the other four an ellipsoidal lesion in the intertrochanteric region, each at the medial, superior/lateral, anterior and posterior side, respectively. One femur of each pair was augmented with polymethylmethacrylate (5–10 ml), while the contralateral femur was left untreated. CT scans were made at three different time points: from the unaffected intact femurs, the defect femurs with lesion and the augmented femurs. Bone strength was measured by mechanical testing until failure in eight defect and eight augmented femurs. Nonlinear CT-based FE models were developed and validated against the experimentally measured bone strength. Subsequently, the validated FE model was applied to the available CT scans for the three different cases: intact (16 scans), defect (16) and augmented (8). The FE predicted strength was compared for the three different cases.

The FE models predicted the experimental bone strength with a strong correspondence, both for the defect (R² = 0.97, RMSE= 0.75 kN) and the augmented femurs (R² = 0.90, RMSE = 0.98 kN). Although all lesions had a “moderate” to “high” risk for fracture according to the Mirels’ scoring system (score 7 or 8), three defect femurs did not fracture through the lesion (intertrochanteric anterior, lateral and posterior), indicating that these lesions did not act as a critical weak spot. In accordance with the experimental findings, the FE models indicated almost no reduction in strength between the intact and defect state for these femurs (0.02 ± 0.1%). For the remaining “critical” lesions, bone strength was reduced with 15.7% (± 14.9%) on average. The largest reduction was observed for lesions on the medial side (up to 43.1%). For the femurs with critical lesions, augmentation increased bone strength with 29.5% (± 29.7%) as compared to the defect cases, reaching strength values that were 2.5% (± 3.7%) higher than the intact bone strength.

Our findings demonstrate that FE models can accurately predict the experimental bone strength before and after augmentation, thereby enabling to quantify the mechanical benefit of femoroplasty. This way FE models could aid in identifying suitable patients for whom femoroplasty provides sufficient increase in strength. For all lesions evaluated in this study, femoroplasty effectively restored the initial bone strength. Yet, additional studies on larger datasets with a wide variation of lesion types are required to confirm these results.

Aim

Negative-pressure wound therapy (NPWT) is often propagated as treatment option for fracture-related infection (FRI). After surgical debridement and repeated NPWT dressing changes, the wounds are often closed by free flaps. Sometimes even healing by secondary intention seems an alternative. Recently, concerns have been raised on the long-term use of NPWT as it could be related to bacterial overgrowth and possible re-infection. The purpose of this study was to conduct a retrospective evaluation of the influence of long-term NPWT on tissue culture results and outcome in FRI patients

Purpose: Plate and cable alone constructs to treat periprosthetic fractures around a well-fixed femoral stem in total hip replacements, have been reported with high failure rates. The aim of this study was to evaluate the results of our surgical treatment algorithm to reliably use lateral plate and cable constructs in these fractures.

Method: One hundred and six periprosthetic fractures in 102 patients were treated between 1996 and 2006. Forty-five fractures were pre-operatively assessed as Vancouver type B1 fractures. The joint was always dislocated and stability of the implant was meticulously evaluated. This led to the identification of nine (20%) unstable stems leaving 36 fractures to be real B1-type fractures. The fracture was considered to be suitable for lateral plate and cable alone fixation if the medial cortex was not comminuted and an anatomical reduction of the medial cortex could be achieved. Twenty-nine B1- and 5 C-type fractures had been treated with a single lateral plate and cable construct. The mean length of follow-up was 43.2 months. The paired Student’s T-test with a confidence interval of 95% and a significant p-value of p< 0.05 was used to compare the pre- and postoperative UCLA hip scores.

Results: Four (12%) patients died within one month from surgery leaving 30 patients for follow-up. Twenty-nine fractures united at a mean of 6.4 months. One B1-type construct failed due to inappropriate proximal fixation. Two fractures united uneventfully with a mean of 8° of varus alignment of the proximal fragment. One patient with a C-type fracture sustained a fracture distal to the tip of the plate. There were three plate infections (8.8%). There was no significant difference between the pre- and post-operative UCLA hip scores (25 versus 23 resp.).

Conclusion: These fractures represent a difficult problem with a high complication rate of 30%. The presented treatment algorithm contributed significantly to the 97% union rate with plate and cable alone constructs that was comparable to the union rates achieved with combined plate and strut graft fixation.