Orthopedic fixation devices and methods of installation thereof

An orthopedic fixation device comprising:

• a tulip element, wherein the tulip element comprises a bore extending therethrough, an interior surface disposed about the bore, an annular channel formed in a distal portion of the interior surface, and a plurality of arms configured to receive an elongate rod;
• a bone fastener, wherein the bone fastener comprises a head and an extension that extends from the head, wherein the head is configured for loading into the tulip element through the bottom of the bore;
• a locking cap assembly, wherein the locking clamp assembly comprises:
• a body having a bore extending through the body and a pair of tabs extending from opposite sides of the body, wherein the bore includes a threaded portion, and wherein a radially outermost surface of each tab includes a flat portion;
• and
• a set screw extending through the bore of the body and having threads corresponding to the threaded portion of the bore of the body;
• a saddle comprising:
• a bore extending through the saddle;
• a lower portion sized and shaped to receive at least a portion of the head of the bone fastener;
• engagement features disposed on opposite sides of an outer surface of the saddle and configured to engage inwardly protruding shoulders of the tulip element;
• and
• at least two elliptical cross-sectional portions;
• and
• a retaining clip disposed on an underside of the head of the fastener in the annular channel of the tulip element, wherein an inner diameter of the retaining clip is less than a maximum diameter of the head of the bone fastener, wherein an upper surface of the retaining clip has a plurality of peaks and troughs such that the peaks are adapted to lock the retaining clip to the fastener to prevent the fastener from moving relative to the coupling element;
• wherein the retaining clip includes:
• an upper annular portion having an upper inner surface and an outer surface that extends vertically downwardly and then laterally inwardly;
• a lower annular portion having a lower inner surface and having an exterior surface that extends vertically downwardly from the laterally extending outer surface of the upper annular portion;
• wherein the upper and lower inner surfaces of the retaining clip provide a continuous concave inner surface that contacts an outer surface of the fastener head.

An orthopedic fixation device comprising:

• a coupling element having a bore extending therethrough, an interior surface disposed about the bore, and an annular channel formed in a distal portion of the interior surface;
• a bone fastener, wherein the bone fastener comprises a head and an extension that extends from the head, wherein the head is configured for loading into the coupling element through the bottom of the bore;
• a threaded locking cap having threads that engage a corresponding threaded portion of the coupling element, wherein lower surfaces of the threads of the threaded locking cap and upper surfaces of threads of the threaded portion of the coupling element slope downward and outward;
• a saddle having a bore extending through the saddle, wherein the saddle includes a lower portion sized and shaped to receive at least a portion of the head of the bone fastener;
• and
• a retaining clip disposed on an underside of the head of the fastener in the annular channel of the coupling element, wherein an inner diameter of the retaining clip is less than a maximum diameter of the head of the bone fastener, wherein an upper surface of the retaining clip has a plurality of peaks and troughs such that the peaks are adapted to lock the retaining clip to the fastener to prevent the fastener from moving relative to the coupling element;
• wherein the retaining clip includes:
• an upper annular portion having an upper inner surface and an outer surface that extends vertically downwardly and then laterally inwardly;
• a lower annular portion having a lower inner surface and having an exterior surface that extends vertically downwardly from the laterally extending outer surface of the upper annular portion;
• wherein the upper and lower inner surfaces of the retaining clip provide a continuous concave inner surface that contacts an outer surface of the fastener head.