What are the 5-year survivorship outcomes of compressive endoprosthetic osseointegration fixation of the femur?

BACKGROUND: Aseptic complications such as stress shielding leading to bone loss are major problems associated with revision of cemented and uncemented long-stem tumor endoprostheses. Endoprosthetic reconstruction using compressive osseointegration fixation is a relatively new limb salvage technology designed to enhance osseointegration, prevent stress shielding, and provide fixation for short end-segments. QUESTIONS/PURPOSES: (1) What is the survivorship of this technique at minimum 5-year followup? (2) Were patient factors (age, sex, body mass index), oncological factors, or anatomic locations associated with implant failure? (3) Were there any prosthesis-related variables associated with failure? METHODS: A single-center, retrospective review of patients with a minimum 5-year followup (mean, 8 years; range, 5-12 years) treated with an osseointegration compressive device for endoprosthetic fixation of proximal and distal femoral limb salvage reconstructions was performed. We have previously published the implant survivorship of this patient cohort with a minimum 2-year followup and are now reporting on the 5-year survivorship data. From 2002 to 2008, we performed 22 such procedures in 22 patients. Four patients died of their disease within 5 years of surgery and all surviving patients (n = 18) had complete followup data at a minimum of 5 years. General indications for this device during that time were pediatric and adult patients requiring primary endoprosthetic reconstructions of the proximal or distal femur for benign and malignant bone lesions. The primary outcome was reoperations for mechanical (aseptic) failures. Secondary outcomes included implant removal for nonmechanical failures and any patient-, oncological-, or implant-related variables associated with implant removal. RESULTS: At a minimum of 5 years followup, overall mechanical (aseptic) implant survivorship was 16 of 18. Survivorship for all modes of failure (oncological failure, infection, arthrofibrosis, and mechanical failure) was 12 of 18. All mechanical failures occurred early, within the first 30 months. We identified no patient-, oncological-, or implant-related features predictive of failure. CONCLUSIONS: Our intermediate-term experience with compressive osseointegration fixation for endoprosthetic limb reconstructions demonstrates with longer clinical followup, no additional mechanical failures were observed as compared with our early analysis. Our experience with this fixation at a minimum of 5-years followup adds to a very limited but increasing body of literature demonstrating that after a transient period of increased risk for implant failures, survivorship stabilizes. Assessment of this fixation strategy beyond 10 years of clinical followup is needed. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Pulmonary and Radiographic Outcomes of VEPTR (Vertical Expandable Prosthetic Titanium Rib) Treatment in Early-Onset Scoliosis.

BACKGROUND: VEPTR (vertical expandable prosthetic titanium rib) expansion thoracoplasty is used to manage thoracic insufficiency syndrome in early-onset scoliosis. Literature regarding the effects of this technique on pulmonary function is scarce. The aim of this study was to report the intermediate-term results of VEPTR expansion thoracoplasty. METHODS: Twenty-one children with thoracic insufficiency syndrome underwent VEPTR expansion thoracoplasty from 2002 to 2012 and had complete chart data, preoperative and follow-up radiographs, and pulmonary function tests performed at the index implantation, first expansion, and last expansion. Pulmonary function tests with forced and passive deflation techniques developed for children under general anesthesia were performed prior to the index implantation and each expansion surgery under the same anesthetic conditions. Pulmonary and radiographic parameters were analyzed longitudinally. RESULTS: Mean follow-up was six years, and mean age at implantation was 4.8 years. The mean number of expansion procedures per patient was eleven, and the mean number of pulmonary function tests was ten. The mean interval between surgical procedures was 6.4 months. Mean forced vital capacity (FVC) increased from 0.65 to 0.96 L (p < 0.0001). However, the percentage of the predicted FVC decreased from 77% to 58%. Respiratory system compliance normalized on the basis of body weight, Crs/kg, decreased by 39%, from 1.4 to 0.86 mL/cm H2O/kg. The mean Cobb angle before treatment was 80°, and the mean maximum thoracic kyphosis angle was 57° (range, 7° to 107°). The initial coronal correction was maintained at the time of final follow-up (67°); however, there was a trend toward a decrease in the maximum thoracic kyphosis angle (to 66°, p = 0.08). Clinically apparent proximal thoracic kyphosis occurred in four patients, and spinal imbalance occurred in seven. The mean gain in T1-T12 height during the treatment period was 18 mm (2.9 mm/year). CONCLUSIONS: FVC improved over time; however, this increase in lung volume did not keep up with the growth of the child, as the percentage of the predicted FVC decreased, and the chest wall stiffness increased. Coronal correction was maintained, but the increase in proximal thoracic kyphosis is concerning. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Using the freehand pedicle screw placement technique in adolescent idiopathic scoliosis surgery: what is the incidence of neurological symptoms secondary to misplaced screws?

STUDY DESIGN: Retrospective case series. OBJECTIVE: This study evaluated the incidence of postoperative neurological symptoms after a freehand pedicle screw insertion technique in idiopathic posterior scoliosis surgery. SUMMARY OF BACKGROUND DATA: It is generally accepted that pedicle screws can be inserted by a freehand technique in the thoracic and lumbar spine in patients with adolescent idiopathic scoliosis (AIS) with a very low frequency of major complications. The prevalence of clinically significant screw misplacement, with or without the need for revision surgery is less well defined. METHODS: Between January 1, 2000, and October 2, 2012, five hundred fifty-nine patients with AIS had thoracolumbar posterior instrumented spine surgery at the Children's Hospital of Pittsburgh. Each patient's chart and radiographs were reviewed and only those with AIS were included. Patients with neuromuscular and syndromic diagnoses were excluded as well as those with congenital or traumatic etiologies, incomplete charts, less than 3 months of follow-up and those without pedicle screws. The records were studied for complaints of radicular pain, neurological deficit, or severe headache that could be indicative of potential screw misplacement. RESULTS: Four hundred eighty-one patients with 5923 pedicle screws met the inclusion criteria. Nine patients (1.9%) developed symptoms and underwent computed tomographic scanning. Six patients were found to have pedicle screw malposition (8 screws) and 3 of these patients underwent revision surgery. Of the 3 revision patients, 2 presented with radicular symptoms (leg pain) and 1 with an orthostatic headache due to cerebrospinal fluid leakage. At the final follow-up, all revision patients had complete symptom resolution. In total, there were 8 symptomatic, misplaced pedicle screws (0.14%) in 6 patients (1.25%). CONCLUSION: During a 12-year period in a dedicated pediatric orthopedic hospital using the freehand placement technique, the incidence of symptomatic misplaced pedicle screws was exceedingly low. LEVEL OF EVIDENCE: 4.

A dual-center review of compressive osseointegration for fixation of massive endoprosthetics: 2- to 9-year followup.

BACKGROUND: Aseptic failure of massive endoprostheses used in the reconstruction of major skeletal defects remains a major clinical problem. Fixation using compressive osseointegration was developed as an alternative to cemented and traditional press-fit fixation in an effort to decrease aseptic failure rates. QUESTIONS/PURPOSES: The purpose of this study was to answer the following questions: (1) What is the survivorship of this technique at minimum 2-year followup? (2) Were patient demographic variables (age, sex) or anatomic location associated with implant failure? (3) Were there any prosthesis-related variables (eg, spindle size) associated with failure? (4) Was there a discernible learning curve associated with the use of the new device as defined by a difference in failure rate early in the series versus later on? METHODS: The first 50 cases using compressive osseointegration fixation from two tertiary referral centers were retrospectively studied. Rates of component removal for any reason and for aseptic failure were calculated. Demographic, surgical, and oncologic factors were analyzed using regression analysis to assess for association with implant failure. Minimum followup was 2 years with a mean of 66 months. Median age at the time of surgery was 14.5 years. RESULTS: A total of 15 (30%) implants were removed for any reason. Of these revisions, seven (14%) were the result of aseptic failure. Five of the seven aseptic failures occurred at less than 1 year (average, 8.3 months), and none occurred beyond 17 months. With the limited numbers available, no demographic, surgical, or prosthesis-related factors correlated with failure. CONCLUSIONS: Most aseptic failures of compressive osseointegration occurred early. Longer followup is needed to determine if this technique is superior to other forms of fixation.

Clinical Decision Making in Early Wound Drainage Following Posterior Spine Surgery in Pediatric Patients.

STUDY DESIGN: Retrospective. OBJECTIVES: To identify the clinical factors suggestive of infected and non-infected drainage to help clinical decision making. SUMMARY OF BACKGROUND DATA: Differentiating between drainage caused by a benign seroma and deep spinal infection may be difficult in the early postoperative period. METHODS: Institutional spine surgery database was searched to identify the cases that were taken back to the operating room for drainage from the surgical wound in the early postoperative period between 2000 and 2012. RESULTS: A total of 38 cases of early wound drainage (within 6 weeks postoperatively) were identified that were treated with opening all layers, irrigation, and debridement. Intraoperative cultures were sent in all cases. Twenty-five patients proved to have non-infected drainage and did not require further treatment. In 13 patients, infection was confirmed with intra-operative findings and cultures; these patients were treated with serial debridements. In 4 cases, implants had to be removed after multiple debridements (after a quiescent period). The group with non-infected drainage differed from the infection group in that most patients (21 of 25) had non-neuromuscular deformities, whereas 77% of the infected group had neuromuscular etiology (10 of 13) (p = .0004). Average number of days to revision was 8.5 (range, 5-14 days) for the non-infected group. Of the 25 patients, 23 presented in the first 10 days. In the infected group, average number of days to revision was 19. Ten of the 13 patients presented on postoperative day 14 or later. Logistic regression analysis showed a significant association between increased likelihood of infection and increased time from the index procedure (p = .0085). CONCLUSIONS: The findings suggest that early presenting drainage in pediatric idiopathic spine deformity is often not infected. Drainage, especially presenting after the second postoperative week in neuromuscular patients, proved to be mostly deep spinal wound infections.