The relationship between patellar volume and trochlear volume in patients with patellofemoral instability.

AIM: To investigate a possible relationship between both the volume and morphology of the patella and the volume of the trochlea in trochlear dysplasia (TD). MATERIALS AND METHODS: Eighteen patients with TD and 18 controls were evaluated retrospectively in two groups using computed tomography (CT). Patellar morphology was evaluated with the standard measurement methods described in the literature. Additionally trochlear sulcus volume (TV) and patellar volume (PV) were measured quantitatively using the three-dimensional volume-rendering method. The relationship between patella dimensions and volume and trochlea volume was evaluated. RESULTS: The length of the medial patellar facet (lMP), patellar width (PW), TV and PV were significantly lower in the patient group. When compared according to Dejour types, PW was statistically significantly lower than the control group in those with high-grade and those with low-grade dysplasia. A positive correlation was found between the TV and PV in both groups (patient group: r=0.583 p=0.011; control group: r=0.485 p=0.042). CONCLUSIONS: PV and the TV are related. Therefore, PV can be used as a determining parameter in the evaluation of TD. This technique can also be used for prosthesis construction and more accurate surgical planning.

Posterior fixation of type IV humeral capitellum fractures with fully threaded screws in adolescents.

PURPOSE: Humeral capitellum fractures comprise approximately 1% of all elbow fractures. In this study, we examined the clinical, radiographic, and functional outcomes following operative stabilization of Bryan and Morrey type IV fractures of the capitellum in adolescents. We applied headless cannulated screws in a posteroanterior direction without damaging the articular cartilage surface of the fractures. METHODS: Eight adolescent patients (six male, two female) with a mean age of 15 ± 2.1 years (range 13-18 years) were treated for type IV (McKee) humerus capitellum fractures. In the preoperative radiological evaluation, anteroposterior and lateral radiographs and computed tomography (CT) images were performed. A lateral surgical approach was used, and cannulated fully threaded headless screws were applied in a posteroanterior direction as fixation materials in the fracture reduction. The Mayo Elbow Performance Score was used in the evaluation of elbow joint functions. RESULTS: Patients were followed up for a mean of 24.6 months. Fracture union was achieved at a mean of 5 ± 0.92 weeks (range 4-6 weeks). The mean elbow extension flexion arc was 135° ± 13.47° (range 110°-150º) and the mean pronation supination arc was 156° ± 4.43° (150°-160°). In one patient, there was nonconformity in the humerus trochlea and in another patient, there was keloid formation on the surgical scar. All patients attained excellent results according to the Mayo Elbow Performance Score. CONCLUSIONS: In the treatment of type IV capitellum fractures in adolescents, open reduction with a lateral surgical approach and fixation using posteroanterior directed, cannulated, fully threaded, headless screws is a reliable method to achieve a pain-free functional elbow joint.