Intra-articular distal femur fracture extending from an expanded femoral tunnel in an anterior cruciate ligament (ACL) reconstructed knee: a case report

Uncommon Complications after Anterior Cruciate Ligament Reconstruction

Anterior cruciate ligament reconstruction (ACL-R) is a common surgical procedure, with good outcome in 75 to 97% of the cases. However, different complications have been described including infection, hemarthrosis, deep vein thrombosis (DVT), and pulmonary embolism (PE) with a rate ranging from 1 to 15%. There are few case reports in the literature describing rare complications after ACL-R and they can be divided into: (1) complications related to the fixation device (rupture, migration); (2) fractures (tibial or femoral side); (3) infections due to uncommon bacteria, mycobacterium, and mycosis; (4) rare vascular injuries; (5) nerve injuries; and (6) other rare complications. In case of fixation device rupture or migration, device removal can be easy but the diagnosis may be challenging. Patellar fracture after ACL-R may be related to harvesting and it is not uncommon. Conversely, femoral or tibial fractures are most frequently due to bone weakness related to bone tunnels. Some rare infections related to uncommon bacteria or mycosis are also described with potentially devastating joint damage. Popliteal artery injuries are uncommon in ACL-R but minor vessels damages are described with possible severe consequences for patients. Injuries to the infrapatellar branch of the saphenous nerve are not uncommon in ACL-R. However, there are few case reports also describing injuries to the saphenous nerve, the common peroneal nerve and the sciatic nerve. The aim of this paper is to review the literature describing uncommon complications after ACL-R, giving some more information about diagnosis and treatment.

Rehabilitation of Tibial Plateau Fracture Following Anterior Cruciate Ligament Reconstruction: A Case Report

Objective

The purpose of this case report was to describe the management of a tibial plateau fracture in a patient who had undergone anterior cruciate ligament (ACL) reconstruction 3.5 years earlier.

Clinical Features

A 36-year-old man presented with pain and edema following a fall from a height of approximately 2 m while skateboarding. The patient reported having undergone arthroscopic ACL reconstruction with allograft and bioabsorbable screws 3.5 years earlier. Computed tomography scan revealed a comminuted fracture extending through the graft tunnel, as well as evidence of tunnel widening and incomplete bone resorption and generation within the tibial tunnel.

Intervention and Outcome

A trauma surgeon repaired the plateau fracture with internal fixation. The patient was non-weight bearing for 8 weeks while undergoing rehabilitation in a chiropractic clinic (spinal manipulation, physiotherapy, nutritional support) twice per week and returned to full activity within 3 months.

Conclusions

The patient responded favorably to the treatment protocol, which included rehabilitation by a doctor of chiropractic and co-management with a trauma surgeon.

Periprosthetic total knee fracture after remote reconstruction of the anterior cruciate ligament: a case report

Background

Distal femoral fracture is a rare, but significant, postoperative complication of anterior cruciate ligament reconstruction. However, there has not been a reported case of periprosthetic total knee arthroplasty fracture associated with a previous anterior cruciate ligament repair.

Case presentation

We report the case of a 51-year-old white man with a history of total knee arthroplasty and remote anterior cruciate ligament reconstruction, who presented with a distal femoral periprosthetic fracture at the site of a previous anterior cruciate ligament augmentation staple.

Conclusions

Based on these findings, it may be important to consider removal of previous anterior cruciate ligament hardware prior to total knee arthroplasty to reduce risk of periprosthetic fracture, which should be determined on a patient-specific basis.

Peri-tunnel bone loss: does it affect early tendon graft to bone tunnel healing after ACL reconstruction?

PURPOSE

The clinical relevance and mechanisms of local bone loss early post-anterior cruciate ligament (ACL) reconstruction remain unclear. The early spatial and temporal changes of peri-tunnel bone, its molecular mechanisms and its relationships with graft-bone tunnel healing were investigated in a 12-week-old rat model.

METHODS

At various times, the reconstructed ACL complex was harvested for vivaCT imaging, biomechanical test, histology and immunohistochemical staining of CD68+ cells (a monocyte-macrophage lineage marker), MMP1 and MMP13.

RESULTS

The peri-tunnel bone resorbed simultaneously with improvement of graft-bone tunnel healing. There were 30.1 ± 17.4, 46.8 ± 10.5 and 81.5 ± 12.3 % loss of peri-tunnel BMD as well as 43.2 ± 21.7, 78.7 ± 8.5 and 92.4 ± 17.7 % loss of peri-tunnel bone volume/total volume (BV/TV) at week 6 at the distal femur, epiphysis and metaphysis of tibia, respectively. MMP1, MMP13 and CD68+ cells were expressed at the graft-bone tunnel interface and peri-tunnel bone and increased with time post-reconstruction at the tibia. The ultimate load and stiffness of the healing complex positively correlated with tibial tunnel bone formation and negatively correlated with tibial peri-tunnel bone. Tunnel BV/TV at the tibial metaphysis and epiphysis showed the highest correlation with ultimate load (ρ = 0.591; p = 0.001) and stiffness (ρ = 0.427; p = 0.026) of the complex, respectively.

CONCLUSION

There was time-dependent loss of peri-tunnel bone early post-reconstruction, with the greatest loss occurring at the tibial metaphysis. This was consistent with high expression of MMP1, MMP13 and CD68+ cells at the graft-bone tunnel interface and the peri-tunnel region. The significant loss of peri-tunnel bone, though not critically affecting early tunnel healing, suggested the need to protect the knee joint early post-reconstruction.

Peri-anterior cruciate ligament reconstruction femur fracture: a biomechanical analysis of the femoral tunnel as a stress riser

PURPOSE

Sixteen case reports of distal femur fractures as post-operative complications after anterior cruciate ligament (ACL) reconstruction have been described in the literature. The femoral tunnel has been suggested as a potential stress riser for fracture formation. Additionally, double bundle ACL reconstructions may compound this risk. This is the first biomechanical study to examine the significance of a stress riser effect of the femoral tunnel(s) after ACL reconstruction. The hypotheses tested in this study are that the femoral tunnel acts as a stress riser for fracture and that this effect increases with the size of the tunnel (8 mm vs. 10 mm) and with the number of tunnels (1 vs. 2).

METHODS

Femoral tunnels simulating single bundle (SB) hamstring graft (8 mm), bone-patellar tendon-bone graft (10 mm), and double bundle (DB) ACL reconstruction (7, 6 mm) were drilled in fourth-generation saw bones. These three experimental groups and a control group consisting of native saw bones without tunnels were loaded to failure.

RESULTS

All fractures occurred through the tunnels in the DB group, whereas fractures did not consistently occur through the tunnels in the SB groups. The mean fracture load was 6,145N ± 471N in the native group, 5,691N ± 198N in the 8 mm SB group, 5,702N ± 282N in the 10 mm SB group, and 4,744N ± 418N in the DB group. The mean fracture load for the DB group was significantly lower when compared to the native, 8 mm SB, and 10 mm SB groups independently (P value = 0.0016, 0.0060, and 0.0038, respectively). The mean fracture loads for neither SB groups were not significantly different from the native group.

CONCLUSIONS

An anatomically placed femoral tunnel in single bundle ACL reconstruction in our experimental model was not a significant stress riser to fracture, whereas the two femoral tunnels in double bundle ACL reconstruction significantly decreased load to failure. The results support the sparsity of reported peri-ACL reconstruction femur fractures in single femoral tunnel techniques. However, the increased fracture risk in double bundle ACL reconstruction may be a cause for concern and impact patient selection.

Tibial plateau fracture after primary anatomic double-bundle anterior cruciate ligament reconstruction: a case report

Tibial plateau fracture after primary anatomic double-bundle anterior cruciate ligament (ACL) reconstruction is rare. To our knowledge, this is the first case report of a tibial plateau fracture after primary anatomic double-bundle ACL reconstruction. In our patient the tibial plateau fracture occurred after a torsional injury to the involved extremity. The fracture occurred 4.5 years after the ACL reconstruction. The fracture was intra-articular Schatzker type IV and had a significant displacement. The patient was treated operatively by open reduction-internal fixation. He recovered well.

Intra-articular lateral femoral condyle fracture following an ACL revision reconstruction

Lateral femoral condyle fractures following an ACL reconstruction are rare. To our knowledge, this is the first case report of a lateral femoral condyle fracture following a revision ACL reconstruction. The patient's fracture was intra-articular, had a significant amount of soft tissue damage, and was further complicated by a large defect involving the bone tunnel from the ACL revision reconstruction. The patient was treated with an open reduction and internal fixation and recovered well.