Lateral patella dislocation associated with an irreducible posterolateral knee dislocation: literature review.

Posterolateral dislocations involve significant injury to the medial structures of the knee, therefore particular attention should be paid to repairing the medial patella stabilizers at the time of open reduction.

The less invasive stabilization system in the treatment of complex fractures of the tibial plateau: short-term results.

OBJECTIVES: To report on the use of a new plating system in the treatment of high-energy tibial plateau fractures using minimally invasive stabilization techniques. DESIGN: Prospective, consecutive patient series. SETTING: University Level I trauma center. PATIENTS: Thirty-seven patients with 39 fractures of the tibial plateau were treated using specialty plates. All fractures were OTA class 41C. Ten of the fractures were open, including eight Gustilo and Anderson Type IIIA and two Type IIIB. Thirty-three patients with 34 fractures had follow-up of at least 12 months. INTERVENTION: Internal fixation with the Less Invasive Stabilization System (LISS, Synthes USA, Paoli, PA) using minimally invasive techniques. MAIN OUTCOME MANAGEMENT: To determine clinical outcome, time to union, fracture alignment, articular step-off, incidence of complications, Short Form-36 outcome scores, and Lysholm knee scores in patients with associated ligament injuries. RESULTS: All 34 of the fractures healed without additional surgical intervention or bone grafting. The mean follow-up in our series was 21 months, with a range of 12 to 38 months. Twenty-nine patients with 30 fractures had follow-up of greater than 1 year. The average time to radiographic callus was 6.1 weeks, and the average time to complete union was 15.6 weeks. The articular step-off average was 0.8 mm, with a range of 0 to 5 mm. The postoperative alignment demonstrated 1 patient with a malalignment of 5 degrees procurvatum and 1 patient with 4 degrees of valgus. There were two superficial wound infections and no cases of deep infection or osteomyelitis. CONCLUSIONS: The use of LISS plates appears to stabilize complex fractures of the tibial plateau with a low incidence of complications. The LISS system functioned well in maintaining alignment and obtaining union in these high-energy fractures.

Fracture of the femoral tunnel after an anterior cruciate ligament reconstruction.

Fractures after anterior cruciate ligament (ACL) reconstructive surgery are rare. Patella fractures can occur as a complication after bone-patellar tendon-bone autografts, and few case reports of tibia fractures have been published. Although reports of femur fractures have been published, the causes are attributed to stress risers other than the femoral tunnel. To our knowledge, this is the first case report of a femoral tunnel serving as a stress riser after an ACL reconstruction with bone-patellar tendon-bone autograft. The patient's fracture resulted from minimal trauma and required surgical fixation.

Tunnel enlargement after anterior cruciate ligament surgery.

Bone tunnel enlargement has been reported after anterior cruciate ligament (ACL) reconstruction surgery. Although the long-term outcome of this phenomenon is not yet known, tunnel lysis or expansion may be clinically significant in revision surgery because the enlarged tunnels may complicate graft placement and fixation. There any many proposed theories for tunnel lysis. The most accurate statement is that this condition has a multifactorial etiology. Mechanical and biological causes have been reported, and both contribute to enlarged graft tunnels. This article describes the multiple causes of bone tunnel enlargement after ACL surgery. Future techniques and advances in primary ACL surgery must seek to eliminate this phenomenon.

Heterotopic ossification associated with knee dislocation.

PURPOSE: The purpose of this study was to determine the prevalence of heterotopic ossification following knee dislocation. TYPE OF STUDY: Prospective clinical evaluation and a retrospective chart review. METHODS: This study evaluated 57 knees in 55 patients who sustained high-energy blunt trauma with resultant knee dislocations. Radiographs were reviewed by 2 of the authors (J.P.S., T.C.W.), and the incidence of heterotopic ossification (HO) was documented. Additionally, patients were classified regarding the degree of HO on a scale from 0 to 4. One is punctate calcification, 2 is HO involving less than 50% of the joint space; 3 is HO involving more than 50%; and 4 is ankylosis of the joint. RESULTS: Thirteen patients with 15 knee dislocations developed HO. The incidence of HO was 26%. Seven knees demonstrated severe HO (grade 3 or 4) which represented an incidence of 12% of all knee dislocations. Injury severity score for both groups was 18, documenting that the patients in this study represent multiple trauma patients. There was no significant difference in the incidence of HO based on mechanism of injury with the current number enrolled in the study. However, 60% (3 of 5) of patients involved in a motor vehicle versus pedestrian accident developed HO. There was a significant increase in the incidence of arthrofibrosis in patients with severe HO (P <.05). Patients with significant HO had a mean flexion of 97 degrees, compared with flexion of 117 degrees in patients with no or mild HO. This difference was borderline significant (P =.058). There was no difference between the groups in mean extension. There was a significant increase in knee HO in patients with HO at another anatomic site (P =.01). CONCLUSIONS: HO is a common problem following knee dislocation. Of the 7 knees with severe HO, 5 developed HO medially, 4 developed HO posteriorly, 3 developed HO laterally, and only 1 had involvement anteriorly. A similar distribution was present in the patients with mild HO, with posterior and medial ossification being the most common. Five of the 7 severe HO cases involved at least 3 of the 4 sides (anterior, posterior, medial, or lateral) of the knee. Patients were evaluated for the presence of head injury and any relationship to the development of HO around the knee. There was no increased incidence of HO around the knee in our 10 patients with severe head injuries when compared with those with no head injury. There was also no increased incidence of HO in knee dislocations associated with periarticular fractures.