Figure 1: Preoperative anteroposterior (AP) pelvis radiograph demonstrating an unstable peritrochanteric fracture with proximal comminution (left). Immediate postoperative AP pelvis radiograph after primary cemented hemiarthroplasty with adjunctive trochanteric stabilization (right).

Figure 2: Lateral radiographs of the affected hip showing preoperative unstable extracapsular fracture morphology (left) and postoperative lateral radiograph demonstrating stem position and restoration of the proximal load pathway after primary arthroplasty (right).

Figure 3: Serial radiographs demonstrating (from left to right) preoperative AP pelvis, immediate postoperative AP pelvis, later follow-up AP pelvis, and follow-up lateral view. The construct maintains position while peritrochanteric osseous response/consolidation develops around the proximal femur.

Figure 4: Preoperative AP radiograph demonstrating an unstable intertrochanteric/peritrochanteric fracture morphology (left). Postoperative AP radiograph after primary total hip arthroplasty, illustrating acetabular component fixation and a long-stem construct spanning the comminuted proximal segment (right).

Figure 5: Composite postoperative imaging including AP pelvis (upper left), lateral hip/femur view (lower left), and standing full-length lower-extremity alignment view (right). The long-stem hip construct coexists with bilateral total knee arthroplasties, highlighting alignment and load-transfer considerations in geriatric patients with multiple arthroplasty implants.

Figure 6: Conceptual phase portrait illustrating the “System-Reset” decision boundary that decouples immediate mechanical stability S(t) from biological reserve/healing capacity B(t). The diagram contrasts probabilistic fixation trajectories in frail/osteoporotic hosts (reliability gap) with competent healing trajectories in robust hosts, and models primary arthroplasty as a deterministic stability step (“system reset”) across the reliability threshold (B_crit).

Figure 7: Conceptual “tactical energy landscape” of primary arthroplasty. The schematic contrasts a higher-entropy operative trajectory (“high-perturbation path,” eg, dislocation plus forceful impaction) with a lower-entropy in-situ/isentropic trajectory that minimizes surgical perturbation while achieving the phase transition to a stable load-accepting construct.

In clinical terms, this trajectory represents the transition from a reliance on callus formation (slow, uncertain) to immediate implant stability (fast, deterministic).