Current concepts in hip–spine relationships: making them practical for total hip arthroplasty

Hip, spine, and pelvis move in coordination with one another during activity, forming the lumbopelvic complex (LPC). These movements are characterized by the spinopelvic parameters sacral slope, pelvic tilt, and pelvic incidence, which define a patient’s morphotype. LPC kinematics may be classified by various systems, the most comprehensive of which is the Bordeaux Classification. Hip–spine relationships in total hip arthroplasty (THA) may influence impingement, dislocation, and edge loading. Historical ‘safe zones’ may not apply to patients with impaired spinopelvic mobility; adjustment of cup inclination and version and stem version may be necessary to achieve functional orientation and avert complications. Stem design, bearing surface (including dual mobility), and head size are part of the armamentarium to treat abnormal hip–spine relationships. Special attention should be directed to patients with adult spine deformity or fused spine because they are at increased risk of complications after THA.

Reactivation of herpes simplex labialis following adult spine deformity correction surgery

Background: A depressed host defense is a major contributor to the oral shedding of herpes simplex virus (HSV) type 1. Here, we present an instance in which herpes simplex labialis was reactivated following major spinal deformity surgery. Case Description: A 59-year-old female underwent spinal deformity correction for lumbar degenerative scoliosis. On postoperative days 2–3, she presented with pyrexia (38°C) and tachycardia (94/min); by day 5 she had multiple ulcers around her lips and was HSV IgG positive. She had a remote history of herpes simplex I infection 7 years previously. Once started on oral acyclovir, the lesions improved, and by day 15 postoperative, her pyrexia and all lesions completely resolved. Conclusion: HSV-1 should be suspected in patients with a previous history of HSV and postoperative pyrexia. Adequate prophylactic administration of acyclovir should result in resolution of these outbreaks, in this case, attributed to overly extensive spinal deformity surgery.

Etiology, diagnosis, and treatment of iatrogenic spinal deformity

Background: Spinal fusion is a common procedure that provides spinal stability by connecting vertebral segments using a bone graft. Because the spinal alignment is fixed permanently after spinal fusion, a mal-aligned fusion can produce iatrogenic spinal deformity and imbalance with significant disability.Current Concepts: Failure to restore adequate segmental lordosis in lumbar spinal fusion is a common cause of iatrogenic spine deformity. Local and regional spinal deformities can affect the global alignment; accordingly, spinal imbalance can occur when the compensation mechanisms fail. Diagnosis and surgical planning should be made on a thorough analysis of global and spinopelvic parameters on the standing whole-spine radiographs. Surgical treatment includes neural decompression, spinal fusion, and deformity correction. Spinal osteotomy provides a favorable surgical outcome, although the complication rate is high.Discussion and Conclusion: Iatrogenic spine deformity is increasing due to the increased occurrence of spinal fusion surgery. To prevent iatrogenic spine deformity, the index fusion surgery should be performed based on a comprehensive analysis of spinopelvic alignment and balance.

3D printing in spine surgery: current and future applications

The revolutionary technology of 3D printing has gained traction in the medical field in recent years; spine surgery has in particular seen major advances in 3D printing. The applications of this technology have grown from utilizing 3D models to enhance patient education to patient specific, highly detailed intraoperative anatomical molds. However, obstacles remain that prevent the widespread utilization of 3D printing in spine surgery such as cost, time consumption, lack of long-term data, and regulation by the US FDA. Despite these obstacles, it is evident that 3D printing will be utilized to optimize preoperative, intraoperative, and postoperative care of patients with spine deformity. The purpose of this review is to establish the applications of 3D printing for spine surgery.