Optimal fixation of oblique scaphoid fractures: a cadaver model.

PURPOSE: Acute scaphoid fractures are commonly fixed with headless cannulated screws positioned in the center of the proximal fragment. Central placement of the screw may be difficult and may violate the scaphotrapezial joint. We hypothesize that placement of the screw through the scaphoid tuberosity will achieve perpendicular fixation of an oblique waist fracture and result in more stable fixation than a screw in the center of the proximal fragment. METHODS: We designed oblique osteotomies for 8 matched pairs of cadaver scaphoids and fixed each specimen with a headless cannulated screw. In 1 specimen, we positioned the screw at the center of the proximal fragment; we placed its matched pair perpendicular to the fracture. The perpendicular screw was directed through the scaphoid tuberosity. We placed the specimen under the increasing load of a pneumatically driven plunger. We compared stiffness, load, distance at failure, and mechanism of failure between the central and perpendicular screw groups. RESULTS: We found no difference between groups. Stiffness was identical in both groups (131 N/mm) and load to failure was similar (central screw, 137 N vs perpendicular screw, 148 N). CONCLUSIONS: In this biomechanical model of an unstable scaphoid fracture, we found that similar stability of fixation had been achieved with a screw perpendicular to the fracture plane with entry through the tuberosity, compared with a screw in a central position in the proximal fragment. This study suggests that placing the screw through the tuberosity, perpendicular to a short oblique fracture, will not impair fixation stability. CLINICAL RELEVANCE: Percutaneous fixation of scaphoid fractures has become popular although it is technically challenging. An easier distal approach through the tuberosity, without violating the scaphotrapezial joint, may not impair the fixation stability of an oblique fracture.

Inferior patellar pole avulsion fractures: osteosynthesis compared with pole resection. Surgical technique.

BACKGROUND: The ideal treatment for avulsion fractures of the inferior pole of the patella has not yet been identified. The options include (1) internal fixation of the pole fragment and (2) resection of the avulsed fragment and repair of the patellar ligament to the patella. We are not aware of any previous study in which the results of internal fixation have been compared with those of pole resection. The purpose of the present study was to compare the long-term results of internal fixation (with use of a basket plate) with those of pole resection. METHODS: We retrospectively studied two groups of patients who had had operative treatment of an avulsion fracture of the inferior patellar pole between 1990 and 1997. Fourteen patients had had internal fixation with a basket plate, and fourteen had had pole resection with patellar ligament repair. Eleven patients who had had internal fixation (Group A) and thirteen patients who had had pole resection (Group B) were followed for an average of 4.6 years. The final evaluation was based on the patellofemoral score, and the patellar height was measured radiographically. RESULTS: The average patellofemoral score (maximum, 100 points) was 94.1 points in Group A and 81.2 points in Group B. Significant differences between the groups were noted with regard to knee pain, level of activity, and range of motion. Normal patellar height was found in ten of eleven patients in Group A and in three of thirteen patients in Group B. Patella baja was significantly associated with a poor functional outcome. CONCLUSIONS: In patients who have sustained an avulsion fracture of the inferior patellar pole, the normal height of the patella can be maintained by preserving the patellar pole. In contrast with pole resection, which requires postoperative immobilization, internal fixation with a basket plate allows for immediate mobilization and early weight-bearing. The present study indicates that internal fixation with use of a basket plate can provide better clinical results.

Inferior patellar pole avulsion fractures: osteosynthesis compared with pole resection.

BACKGROUND: The ideal treatment for avulsion fractures of the inferior pole of the patella has not yet been identified. The options include (1) internal fixation of the pole fragment and (2) resection of the avulsed fragment and repair of the patellar ligament to the patella. We are not aware of any previous study in which the results of internal fixation have been compared with those of pole resection. The purpose of the present study was to compare the long-term results of internal fixation (with use of a basket plate) with those of pole resection. METHODS: We retrospectively studied two groups of patients who had had operative treatment of an avulsion fracture of the inferior patellar pole between 1990 and 1997. Fourteen patients had had internal fixation with a basket plate, and fourteen had had pole resection with patellar ligament repair. Eleven patients who had had internal fixation (Group A) and thirteen patients who had had pole resection (Group B) were followed for an average of 4.6 years. The final evaluation was based on the patellofemoral score, and the patellar height was measured radiographically. RESULTS: The average patellofemoral score (maximum, 100 points) was 94.1 points in Group A and 81.2 points in Group B. Significant differences between the groups were noted with regard to knee pain, level of activity, and range of motion. Normal patellar height was found in ten of eleven patients in Group A and in three of thirteen patients in Group B. Patella baja was significantly associated with a poor functional outcome. CONCLUSIONS: In patients who have sustained an avulsion fracture of the inferior patellar pole, the normal height of the patella can be maintained by preserving the patellar pole. In contrast with pole resection, which requires postoperative immobilization, internal fixation with a basket plate allows for immediate mobilization and early weight-bearing. The present study indicates that internal fixation with use of a basket plate can provide better clinical results.