Objective To observe foe microstructure of calcar femorale in young and old people andto investigate its clinical significance. Methods Twelve fresh cadaveric proximal femurs harvested from sixyoung(18~30 years) and six old (over 60 years) adults were used in this study. At first, CT scanning of allproximal femurs were taken. Secondly, the cross section of all calcar femorale were X - rayed and observedunder light microscope and scanning electron microscope. Results The calcar femorale can be divided intothree regions on the cross section. The structure of the medial region is conical bone which unites with medialcortex, and it mainly enhances the strength of the femoral neck. Its middle region is spongy conical bone andits lateral region has become trabecular bone. These two regions can transfer the compressive load that comefrom femoral head to the medial femoral cortex below the lesser trochanter, so they can disperse the load offemoral neck. Severe resorption can occur in the calcar femorale in old people, especially in the lateral region.Conclusion The destruction of three dimensional microstructure and ultra-microstructure of calcar femoralecan result in the decline of its mechanical competence and its ability of load transmission.

BACKGROUNDThe purpose of this retrospective study was to compare the surgical outcomes of simple discectomy and instrumented posterior lumbar interbody fusion (iPLIF) in patients with lumbar disc herniation and Modic endplate changes. Our hypothesis was that iPLIF could provide better outcome for patients with refractory lumbar disc herniation and Modic changes (LDH-MC).

METHODSNinety-one patients with single-segment LDH-MC were recruited. All patients experienced low back pain as well as radicular leg pain, and low back pain was more severe than leg pain. Forty-seven patients were treated with discectomy and 44 were treated with iPLIF. The outcomes of both low back pain and radicular leg pain using visual analogue scale (VAS) as well as the clinical outcome related to low back pain using Japanese Orthopaedic Association (JOA) score were assessed before and 18 months after surgery, respectively.

RESULTSBoth low back and leg pain were significantly improved 18 months after simple discectomy and iPLIF. Compared to patients undergoing simple discectomy, low back pain was significantly reduced in patients undergoing iPLIF, but there was no significant difference in leg pain between two groups. Solid fusion was achieved in all patients who underwent iPLIF.

CONCLUSIONSIn patients with LDH-MC, iPLIF can yield significantly superior outcome on the relief of low back pain compared to simple discectomy. Simple discectomy can relieve radicular leg pain as efficient as iPLIF. Accordingly, iPLIF seems to be a reliable treatment for patients with LDH-MC and predominant low back pain.

Adult ; Diskectomy ; standards ; Female ; Humans ; Intervertebral Disc Displacement ; surgery ; Low Back Pain ; surgery ; Lumbar Vertebrae ; surgery ; Middle Aged ; Retrospective Studies ; Spinal Fusion ; standards