Re-evaluation of pectoralis major height as an anatomic reference for humeral height in fracture hemiarthroplasty.

BACKGROUND: Shoulder replacement may be indicated for complex proximal humeral fractures. The primary reason for disappointing results is the nonanatomic position of the prosthesis because the normal anatomic landmarks are disrupted when fractured. An anatomic reference outside of the zone of injury may facilitate proper positioning of fracture arthroplasty reconstructions. It is unknown whether the measurement from the top of the pectoralis major tendon (PMT) to the top of the humeral head is related to patient height. MATERIALS AND METHODS: PMT measurements were performed on 21 pairs of cadaveric shoulders. A second group of PMT measurements was performed on 107 patients receiving a shoulder magnetic resonance imaging scan. A third PMT comparison group was included using historical measurements from 20 pairs of cadaveric shoulders. All heights, sexes, and ages were known. Statistical analysis used mixed-effects linear regression models. RESULTS: A consistent association between patient height and PMT was found, with a mean distance from the top of the PMT to the top of the humeral head of 58.9 mm in men and 55.2 mm in women. For every 10-mm increase in patient height over 1.7 m, there is a 1.7-mm increase in PMT (P = .01). Age was not associated with PMT distance (P > .5). CONCLUSIONS: A predictable measurement from the upper portion of the PMT to the top of the humeral head exists to guide implant height in fracture hemiarthroplasty and may be approximated by use of patient height and sex.

Quantitative perfusion- and diffusion-weighted magnetic resonance imaging of gastrointestinal cancers treated with multikinase inhibitors: a pilot study.

BACKGROUND: Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion-weighted imaging (DWI) are often used to detect the early response of solid tumors to an effective therapy. The early changes in intratumoral physiological parameters measured by DCE-MRI/DWI have been evaluated as surrogate biomarkers allowing a tailored treatment for the individual patient. METHODS: Patients with newly diagnosed, biopsy-proven, treatment-naïve gastrointestinal stromal tumor (GIST) or hepatocellular carcinoma (HCC) were enrolled prospectively after institutional review board (IRB)-approved informed consent (5 patients per tumor type). Patients with GIST were treated with sunitinib over 6 weeks. DCE-MRI/DWI was applied before therapy (baseline imaging) and at 2 and 6 weeks after therapy initiation. Patients with HCC were treated with radiation during the first 2 weeks and then with sorafenib for the next 6 weeks. DCE-MRI/DWI was applied in all patients with HCC before and after radiation therapy and at the end of sorafenib therapy. Tumor volume, perfusion parameters (K (trans), the forward volume-transfer constant, and k ep, the reverse reflux-rate constant) and the apparent diffusion coefficient (ADC) were measured. RESULTS: During 2 weeks of sunitinib therapy, GIST volume, K (trans), and k ep decreased 32 ± 13, 45 ± 24, and 42 ± 15%, respectively, whereas ADC increased 76 ± 24%. After 6 weeks of sunitinib therapy, GIST volume, K (trans), and k ep decreased 56 ± 7, 70 ± 7, and 50 ± 12%, respectively, whereas ADC increased 85 ± 33%. After completion of radiation therapy, HCC volume, K (trans), and k ep decreased 34 ± 14, 35 ± 12, and 4 ± 21%, respectively, but ADC increased 21 ± 9%. During the entire 10-week therapeutic period, HCC volume, K (trans), and k ep decreased 65 ± 15, 40 ± 9, and 26 ± 2%, respectively, whereas ADC increased 28 ± 10%. CONCLUSION: DCE-MRI/DWI can measure the perfusion and diffusion changes in GISTs or HCCs treated with multikinase inhibitors.