Scapholunate Ligament Injury and the Effect of Scaphoid Lengthening.

Objective We hypothesized that lengthening the scaphoid in a model of scapholunate ligament injury (SLI) will result in correction of radiographic markers of dorsal intercalated segment instability (DISI) deformity. Materials and Methods An SLI with DISI deformity was created by sectioning the SL ligament, the palmar radiocarpal ligaments, and scapho-trapezio-trapezoid ligaments of a cadaveric upper extremity ( n = 5). The wrist was radiographed in both anteroposterior and lateral planes to confirm creation of SLI and DISI. The scaphoid was then osteotomized at its waist. A series of grafts (1-8 mm) were then placed at the osteotomy site. Radiographs were completed at each length. The main outcome measures were scapholunate interval (SL, mm), scapholunate angle (SLA, degrees), and radiolunate angle (RLA, degrees). These values, measured following the insertion of varying graft lengths, were compared with baseline measurements taken "post-injury" status. Results The ability to create an SLI with DISI was confirmed in the postinjury group with a statistically significant change in RLA, SLA, and SL compared with preinjury. With osteotomy and progressive insertion of spacers, the values improved into the accepted normal ranges for RLA (6 mm) and SLA (4 mm) with scaphoid lengthening. Conclusions In this cadaveric model of SL injury, radiographic markers of DISI were returned to within normal ranges with scaphoid osteotomy and lengthening. Clinical Relevance The results of this study add insight into wrist kinematics in our injury model and may represent a potential future direction for surgical treatment of SLI.

Clavicular Refracture at the Site of Angular Malunion in Young Athletes.

OBJECTIVE: The treatment of midshaft clavicle fractures has, in the last 2 decades, shifted markedly towards operative management. Prospective trials have defined accepted clinical and radiographic indications for the surgical management of clavicle fractures. This report documents 3 cases of clinically united angular malunion of the midshaft clavicle in young athletes that subsequently refractured to highlight angular deformity in the absence of displacement as a potential indication for surgical fixation. DESIGN: Case series. SETTING: A level 1 trauma centre. PATIENTS/PARTICIPANTS: Three young athletic patients with angular malunion of the midshaft clavicle who experienced refracture, requiring surgical fixation. INTERVENTION: Surgical fixation of midshaft clavicle fracture, as treatment for refracture after angular malunion. RESULTS: All 3 patients required subsequent surgical fixation of their midshaft clavicle fracture, correcting the angular malunion and restoring shoulder function. CONCLUSIONS: Midshaft clavicular fractures that malunite with significant angulation in the absence of displacement represent a risk for subsequent refracture. For this reason, angular deformity should be considered as a potential indication for surgical fixation in acute clavicular fractures. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

A retrospective cohort study of displaced segmental radial head fractures: is 2 mm of articular displacement an indication for surgery?

HYPOTHESIS: Many investigators agree that 2 mm of articular displacement is a reasonable indication for open reduction and internal fixation of Mason type II fractures of the radial head. However, there is no evidence to support that this degree of articular displacement is predictive of poor outcomes in conservatively treated fractures. We hypothesized there would be no difference between conservatively treated radial head fractures with greater 2 mm of displacement and those with less than 2 mm of displacement in terms of patient-reported or clinical outcomes. MATERIALS AND METHODS: We reviewed databases of all radial head fractures in our region. The primary outcomes were the Patient-Rated Elbow Evaluation and Disabilities of the Arm, Shoulder and Hand questionnaires. Secondary outcomes included radiologic radiocapitellar arthritis and range of motion (ROM) at follow-up. Postinjury treatment protocols, as well as patient factors, were examined for their effects on outcome. RESULTS: The results showed no significant difference in any outcome for conservatively treated radial head fractures with 2 mm (P = .8) or even 3 mm (P = .6) of articular displacement over a mean follow-up of 4.4 years. Early ROM and physiotherapy showed no significant differences in any outcome measure. Dominant hand injury showed no significant difference in patient-reported outcomes; however, ROM was significantly decreased on examination. CONCLUSIONS: This retrospective review suggests that fracture displacement of 2 to 3 mm is not necessarily an indication for surgical fixation in isolated fractures of the radial head. In addition, it appears that postinjury ROM/physiotherapy does not play a large role in improving patient outcome.

Segond fractures: not necessarily pathognemonic of anterior cruciate ligament injury in the pediatric population.

Initially described following cadaveric studies in the late 19th century by Dr. Paul Segond, the Segond fracture is now widely accepted as a pathognemonic radiographic marker of anterior cruciate ligament injury. This fracture in a skeletally immature 16-year-old was not seen with an anterior cruciate ligament injury, but with a Salter-Harris type IV fracture of the tibial plateau. A nonweightbearing knee immobilizer with the leg in full extension was used for 6 weeks. Recovery was uncomplicated, and range of motion and weightbearing began at 6 weeks.

Prolonged target deprivation reduces the capacity of injured motoneurons to regenerate.

OBJECTIVE: To investigate whether or not it is the frustrated growth state (no axon growth) that reduces regenerative capacity or the inability of axotomized motoneurons to remake muscle connections (axon growth-no muscle contact) that accounts for poor regenerative capacity of chronically axotomized motoneurons. METHODS: We chronically axotomized rat femoral motoneurons for 2 months by cutting the nerve and either capping the proximal nerve to prevent axon regeneration (Group 1, no axon growth for 2 mo) or encouraging axon regeneration but not target reinnervation by suture to the distal stump of cut saphenous nerve (Group 2, axon growth with no muscle contact). In the control fresh axotomy group (axon growth with muscle contact), femoral nerve stumps were resutured immediately. Two months later, the femoral nerve was recut and sutured immediately to encourage regeneration in a freshly cut saphenous nerve stump for 6 weeks. Regenerating axons in the saphenous nerve were back-labeled with fluorogold for enumeration of the femoral motoneurons that regenerated their axons into the distal nerve stump. RESULTS: We found that significantly fewer chronically axotomized motoneurons regenerated their axons than freshly axotomized motoneurons that regenerated their axons to reform nerve-muscle connections in the same length of time. The number of motoneurons that regenerated their axons was reduced in both the conditions of no axon growth and axon growth with no muscle contact; thus chronic axotomy for a 2-month period reduced regenerative success irrespective of whether the motoneurons were prevented from regenerating or encouraged to regenerate their axons in that same period of time. CONCLUSION: Axonal regeneration does not protect motoneurons from the negative effects of prolonged axotomy on regenerative capacity. It is the period of chronic axotomy, in which motoneurons remain without target nerve-muscle connection, and not simply a state of frustrated growth that accounts for the reduced regenerative capacity of those neurons.